[Federal Register Volume 63, Number 151 (Thursday, August 6, 1998)]
[Rules and Regulations]
[Pages 42110-42189]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-19929]



[[Page 42109]]

_______________________________________________________________________

Part II





Environmental Protection Agency





_______________________________________________________________________



40 CFR Parts 148, 261, 266, etc.



Hazardous Waste Management System; Identification and Listing of 
Hazardous Waste; et al.; Final Rule and Proposed Rule

  Federal Register / Vol. 63, No. 151 / Thursday, August 6, 1998 / 
Rules and Regulations  

[[Page 42110]]



ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 148, 261, 266, 268, 271, and 302

[SWH-FRL-6122-7]
RIN 2050-AD88


Hazardous Waste Management System; Identification and Listing of 
Hazardous Waste; Petroleum Refining Process Wastes; Land Disposal 
Restrictions for Newly Identified Wastes; And CERCLA Hazardous 
Substance Designation and Reportable Quantities

AGENCY: Environmental Protection Agency.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: The Environmental Protection Agency (EPA) is amending the 
regulations for hazardous waste management under the Resource 
Conservation and Recovery Act (RCRA) to reduce hazards to human health 
and the environment from wastes generated from petroleum refining. EPA 
is listing as hazardous four wastes generated during petroleum refining 
and is issuing a decision not to list ten other petroleum refining 
wastes.
    This action is taken under the authority of RCRA 3001(b)(1), which 
authorizes EPA to list wastes as hazardous, and 3001(e)(2), which 
directs EPA to make a decision whether to list as hazardous the various 
petroleum refining wastes. The effect of listing these four wastes will 
be to subject them to stringent management and treatment standards 
under RCRA and to emergency notification requirements for releases of 
hazardous substances to the environment. These notifications are 
required under the Comprehensive Environmental Response, Compensation, 
and Liability Act (CERCLA or Superfund) and the Emergency Planning and 
Community Right to Know Act (EPCRA). EPA is also issuing Reportable 
Quantity (RQ) adjustments for these notifications.
    This action also makes certain changes to the RCRA regulations to 
promote the environmentally sound recycling of oil-bearing residuals. 
Specifically, the Agency is excluding certain recycled secondary 
materials from the definition of solid waste. These materials include 
oil-bearing residuals from petroleum refineries when they are inserted 
into the petroleum refining process, oil from associated petrochemical 
facilities inserted into the petroleum refining process, and spent 
caustic from liquid treating operations when used as a feedstock to 
make certain chemical products. This rule also clarifies an existing 
exclusion for recovered oil from certain petroleum industry sources.
    Finally, EPA is applying universal treatment standards (UTS) under 
the Land Disposal Restrictions program to the petroleum refining wastes 
listed in this rulemaking. The listed wastes must be treated to meet 
these treatment standards for specific constituents prior to land 
disposal.

EFFECTIVE DATES: This final rule is effective February 8, 1999, except 
for the amendments to Secs. 261.3(c)(2)(ii)(B), 261.4(a), 
261.6(a)(3)(iv)(C) and 261.100(b)(3) and the removal of 
Sec. 261.6(a)(3)(v) which are effective August 6, 1998.

ADDRESSES: Supporting materials are available for viewing in the RCRA 
Information Center (RIC), located at Crystal Gateway I, First Floor, 
1235 Jefferson Davis Highway, Arlington, VA. The Docket Identification 
Number is F-98-PRLF-FFFFF. The RIC is open from 9 a.m. to 4 p.m., 
Monday through Friday, excluding federal holidays. To review docket 
materials, it is recommended that the public make an appointment by 
calling 703 603-9230. The public may copy a maximum of 100 pages from 
any regulatory docket at no charge. Additional copies cost $0.15/page. 
The index and some supporting materials are available electronically. 
See the beginning of the Supplementary Information section for 
information on accessing them.

FOR FURTHER INFORMATION CONTACT: The RCRA/Superfund Hotline, toll-free, 
at (800) 424-9346 or at (703) 920-9810. The TDD Hotline number is (800) 
553-7672 (toll-free) or (703) 486-3323 in the Washington, DC., 
metropolitan area.
    For technical information on the RCRA hazardous waste listings, 
contact Maximo (Max) Diaz, Jr., or Robert Kayser, Office of Solid Waste 
(5304W), U.S. Environmental Protection Agency, 1235 Jefferson Davis 
Highway, Arlington, VA, (703) 308-0439. [E-mail addresses and telephone 
numbers: [email protected], (703) 308-0439; 
[email protected], (703) 308-7304.] For information related 
to the exclusions from the definition of solid waste, contact Ross 
Elliott at the same address. [[email protected]; (703) 308-
8748.]
    For technical information on the CERCLA aspects of this rule, 
contact: Ms. Elizabeth Zeller, Office of Emergency and Remedial 
Response (5204G), U.S. Environmental Protection Agency, 401 M Street, 
SW, Washington, D.C., 20460, (703) 603-8744.

SUPPLEMENTARY INFORMATION: The index and the supporting materials are 
available on the Internet. Follow these instructions to access the 
information electronically:

www:http://www.epa.gov/epaoswer/osw/hazwaste.htm#id
FTP: ftp.epa.gov
Login: anonymous
Password: your Internet address
Files are located in /pub/epaoswer

    The contents of the preamble to this final rule are listed in the 
following outline:

I. Affected Entities
II. Legal Authority and Background
    A. Listing Decisions
    B. Definition of Solid Waste and Exclusions
III. Summary of Proposal and Notice of Data Availability
    A. Proposed Exclusions
    1. Exclusion of Oil-Bearing Hazardous Secondary Materials 
Inserted into Petroleum Refining, Including Petroleum Coking
    2. Recovered Oil From Associated Petrochemical Facilities
    3. Use of Spent Caustics as Feedstock
    B. Proposed Listing Decisions
    1. Summary of Proposed Decisions
    2. Summary of Proposed Risk Assessment Approach
    C. Notice of Data Availability
IV. Changes to the Proposed Rule
    A. Definition of Solid Waste Exclusions
    1. Exclusion of Oil-Bearing Hazardous Secondary Materials 
Inserted into Petroleum Refining, Including Petroleum Coking
    2. Recovered Oil From Associated Petrochemical Facilities
    3. Use of Spent Caustic as Feedstock
    B. Listing Determinations
    C. Other Exemptions
    1. Headworks Exemption
    2. Exemption for Catalyst Support
    3. Third Party Recycling of Spent Petroleum Catalysts
V. Response to Comments and Rationale for Final Rule
    A. Proposed Modifications to the Definition of Solid Waste
    1. Exclusion of Oil-Bearing Hazardous Secondary Materials 
Inserted into Petroleum Refining, Including Petroleum Coking
    2. Recovered Oil From Associated Petrochemical Facilities
    B. Modeling Approaches and Risk Assessment
    1. Sampling and Analysis of Refinery Wastes
    2. Waste Management Assumptions
    3. Codisposal of Wastes
    4. Impact of Hazardous Characteristic Regulations
    5. Other General Risk Issues
    6. Specific Groundwater Modeling Issues
    7. Specific Nongroundwater Modeling Issues

[[Page 42111]]

    C. Residual-Specific Comments
    1. Crude Oil Storage Tank Sediment
    2. Clarified Slurry Oil Sediment
    3. Catalyst From Hydrotreating and Hydrorefining
    4. Catalyst From Sulfuric Acid Alkylation
    5. Spent Caustic From Liquid Treating
    6. Off-Specification Product and Fines From Thermal Processes
    7. Catalyst and Fines From Catalytic Cracking
    8. HF Alkylation Sludge
    9. Sludge From Sulfur Complex and Hydrogen Sulfide Removal 
Facilities
    10. Catalyst From Sulfur Complex and Hydrogen Sulfide Removal 
Facilities
    11. Unleaded Gasoline Storage Tank Sediment
    12. Catalyst From Reforming
    13. Sludge From Sulfuric Acid Alkylation
    D. Headworks Exemption
    1. Application to Listed Catalysts
    2. Clarification of Scope
    3. Comments Opposing the Exemption
    E. Third Party Recycling of Spent Petroleum Catalysts
VI. Land Disposal Restrictions
    A. Treatment Standards for Newly Identified Wastes
    B. Response to Comments
    1. Constituents of Concern
    2. Sulfides
    3. Underlying Hazardous Constituents
    4. High Temperature Metals Recovery
    5. Vanadium
    6. Revisions to Proposed Standards
    C. Capacity Determination for Newly Identified Wastes
    1. Introduction
    2. Capacity Analysis Results Summary
VII. Compliance and Implementation
    A. State Authority
    1. Applicability of Rules in Authorized States
    2. Effect on State Authorizations
    B. Effective Date
    C. Section 3010 Notification
    D. Generators and Transporters
    E. Facilities Subject to RCRA Permit Requirements
    1. Facilities Newly Subject to RCRA Permit
    2. Existing Interim Status Facilities
    3. Permitted Facilities
    4. Units
    5. Closure
    F. Landfill Leachate
VIII. CERCLA Designation and Reportable Quantities
    A. Reporting Requirements
    B. Standard and Alternative RQ Adjustment Methodology
    C. Basis for RQ Adjustments in Final Rule
    D. Response to Comments
IX. Executive Order 12866
X. Economic Analysis
    A. Compliance Costs for Listings Including LDR Impacts and the 
Exclusion for Oil-Bearing Hazardous Secondary Materials
    1. Universe of Petroleum Refineries and Waste Volumes
    2. Methodology for Estimating Industry Economic Impact and 
Incremental Compliance Cost
    3. Potential Remedial Action Costs Within the Refining Industry
    4. Summary of Compliance Cost Results
    B. Details of Industry Economic Impact
XI. Regulatory Flexibility Act
XII. Submission to Congress and the General Accounting Office
XIII. Unfunded Mandates
XIV. Paperwork Reduction Act
XV. National Technology Transfer and Advancement Act
XVI. Executive Order 13045--Protection of Children from 
Environmental Health Risks and Safety Risks

I. Affected Entities

    Entities potentially affected by this action are those which handle 
either the waste streams being added to EPA's list of hazardous wastes 
under RCRA and to the CERCLA list, or entities which need to respond to 
releases. Affected entities include:

------------------------------------------------------------------------
           Category                        Affected entities            
------------------------------------------------------------------------
Industry.....................  Generators of the following listed       
                                wastes, or entities that treat, store,  
                                transport, or dispose of these wastes.  
                               K169--Crude oil storage tank sediment    
                                from petroleum refining operations.     
                               K170--Clarified slurry oil storage tank  
                                sediment and/or in-line filter/         
                                separation solids from petroleum        
                                refining operations.                    
                               K171--Spent hydrotreating catalyst from  
                                petroleum refining operations, including
                                guard beds used to desulfurize feeds to 
                                other catalytic units (this listing does
                                not include inert support media).       
                               K172--Spent hydrorefining catalyst from  
                                petroleum refining operations, including
                                guard beds used to desulfurize feeds to 
                                other catalytic units (this listing does
                                not include inert support media).       
State, Local, Tribal Govt....  State and local emergency planning       
                                entities.                               
Federal Govt.................  National Response Center, and any Federal
                                Agency that handles the listed waste or 
                                chemical.                               
------------------------------------------------------------------------

    This table is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities likely to be affected by this 
action. This table lists those entities of which EPA now is aware that 
potentially could be affected by this action. Other entities not listed 
in the table also could be affected. To determine whether your facility 
is regulated by this action, you should examine 40 CFR Parts 260 and 
261 carefully in concert with the amended rules found at the end of 
this Federal Register notice. If you have questions regarding the 
applicability of this action to a particular entity, consult the person 
listed in the preceding FOR FURTHER INFORMATION CONTACT section.

II. Legal Authority and Background

    These regulations are being promulgated under the authority of 
sections 2002(a) and 3001(a), (b) and (e)(2), 3004 (g) and (m) of the 
Solid Waste Disposal Act (commonly referred to as RCRA), as amended, 42 
U.S.C. 6912(a), and 6921(b) and (e)(2), and section 102(a) of CERCLA, 
42 U.S.C. 9602(a).

A. Listing Decisions

    Section 3001(a) of RCRA requires EPA to promulgate criteria for 
identifying characteristics of hazardous wastes and for listing 
hazardous wastes. Section 3001(b) authorizes EPA to promulgate 
regulations, based on these criteria, identifying and listing hazardous 
wastes. Section 3001(e)(2) of RCRA requires EPA to determine whether to 
list, as hazardous, wastes generated by specific industries and 
production processes, including petroleum refining wastes. Hazardous 
waste, for purposes of this rule, is defined at section 1004(5)(B) of 
RCRA as solid waste which may pose a substantial present or potential 
hazard to human health or the environment when improperly managed.
    Hazardous wastes are subject to management and treatment 
requirements of RCRA Subtitle C, which establishes stringent federal 
requirements, including the need to obtain facility operating permits 
for persons who generate, transport, treat, store, or dispose of such 
waste. Solid wastes which are not hazardous may be disposed of at 
facilities which are overseen by state and local governments. These are 
the so-called RCRA subtitle D facilities, which generally impose less 
stringent requirements on management of wastes.

[[Page 42112]]

    EPA's regulations at 40 CFR 261.20 provide that hazardous wastes 
may be classified as ``characteristic'' wastes if they have the 
properties described at 40 CFR 261.21 through 261.24, which would cause 
them to be classified as having the characteristics of ignitability, 
corrosivity, reactivity, or toxicity. Characteristic wastes are 
identified by sampling a waste, or using appropriate company records 
concerning the nature of the waste, to determine whether a waste has 
the relevant properties. There is no regulatory requirement to conduct 
sampling, but persons managing materials that are found to be 
characteristic hazardous wastes are subject to enforcement actions 
under RCRA.
    Criteria for listing hazardous wastes are found at 40 CFR 
261.11(a)(3), which provides that wastes may be listed as hazardous if 
they contain hazardous constituents identified in appendix VIII of 40 
CFR part 261 and the Agency concludes, after considering eleven factors 
enumerated in Sec. 261.11(a)(3), that the waste is capable of posing a 
substantial present or potential hazard to human health or the 
environment when improperly managed. A substance is listed in appendix 
VIII if it has been shown in scientific studies to have toxic effects 
on life forms.
    EPA's regulations at 40 CFR 261.31 through 261.33 contain the 
various hazardous wastes the Agency has listed from time to time. 
Section 261.31 lists wastes generated from non-specific sources, known 
as ``F-wastes,'' and Sec. 261.32 lists hazardous wastes generated from 
specific sources, known as ``K-wastes.'' Pursuant to the requirement of 
RCRA section 3001(e)(2) to list refinery wastes, EPA has previously 
listed various petroleum refinery wastes designated as F037, F038, and 
K048 through K052. Section 261.33 lists as hazardous discarded 
commercial chemical products and other materials that become hazardous 
wastes, known as ``P-wastes'' or ``U-wastes,'' when they are discarded 
or intended to be discarded.
    Therefore, newly listed wastes in this rule will be added to the K-
waste list. Once listed, wastes must be managed as RCRA Subtitle C 
hazardous wastes. No testing of waste samples is required as for 
characteristic hazardous wastes.
    On June 12, 1997, EPA entered into a proposed amended consent 
decree in a lawsuit filed by the Environmental Defense Fund (EDF)--EDF 
v. Browner, Civ. No. 89-0598 (D.D.C.). The consent decree sets out a 
series of deadlines for promulgating RCRA rules. Paragraph 1.k. of the 
proposed amended consent decree obligated EPA to promulgate a final 
listing determination on or before May 29, 1998 (EPA and EDF have since 
agreed to extend this date to June 29, 1998), for 14 additional 
petroleum refining process residuals. Today, EPA is issuing final 
listing determinations for these residuals (hereafter, ``listing 
residuals'') in accordance with the proposed consent decree's deadline. 
The consent decree also identified another 15 petroleum refining 
residuals for which EPA agreed to conduct a study (hereafter, ``study 
residuals''). EPA published the study in 1996. (See Study of Selected 
Petroleum Refining Residuals-Industry Study, August 1996; EPA530-R-96-
018.)
    All hazardous wastes listed under RCRA and codified in 40 CFR 
261.31 through 261.33, as well as any solid waste that exhibits one or 
more of the characteristics of a RCRA hazardous waste, described in 40 
CFR 261.20 through 261.24, are also hazardous substances under CERCLA, 
as provided in CERCLA section 101(14)(C). CERCLA hazardous substances 
are listed in Table 302.4 at 40 CFR 302.4 along with their reportable 
quantities (RQs). Today's rule also establishes RQs for the newly 
listed wastes.
    Today's listing determination follows the elements of EPA's 
hazardous waste listing policy presented in the dyes and pigments 
listing determination proposal (59 FR 66072, December 22, 1994). A 
description of how elements of EPA's listing policy were applied in 
today's listing determination is found in Section III.F.2., ``Risk 
Analysis,'' of the preamble for the proposed rule. Section V.C of this 
preamble discusses EPA's responses to comments and final decisions as 
they relate to the various elements of the listing policy and their 
applicability to this rule.

B. Definition of Solid Waste and Exclusions

    The jurisdictional boundaries of RCRA are established primarily by 
the definition of solid waste. When hazardous sludges, by-products, and 
spent materials (often referred to as a group as ``secondary 
materials'') are recycled, a question exists as to whether such 
materials are ``solid wastes'' and so potentially within EPA's subtitle 
C jurisdiction. The regulatory definition of solid waste, found at 40 
CFR 261.2, answers these questions, since only materials which meet 
this definition are even potentially subject to the subtitle C 
regulatory program set out at 40 CFR Parts 262-268. Secondary materials 
may be excluded from the definition of solid waste, and therefore from 
regulation under this regulatory program, if they are recycled in 
certain ways. The current definition of solid waste at 40 CFR 261.2 
excludes secondary materials from the definition of solid waste that 
are used directly (i.e., without reclamation) as ingredients in 
manufacturing processes to make new products, used directly as 
effective substitutes for commercial products, or returned directly to 
the original process from which they are generated as a substitute for 
raw material feedstock. (See 40 CFR 261.2(e)(1)). As discussed in the 
January 4, 1985, rulemaking that promulgated this regulatory framework, 
these are activities which, as a general matter, resemble ongoing 
manufacturing operations more than conventional waste management and so 
are more appropriately classified as not involving solid wastes. (See 
50 FR at 637-640).
    However, these exclusions do not apply to materials that are either 
contained in, or used to produce, fuels and, therefore, do not 
generally apply to secondary materials recycled as part of the 
petroleum refining process (see 40 CFR 261.2(e)(2)(ii)). Petroleum 
industry representatives have long argued that oil-bearing secondary 
materials used as ingredients in a petroleum refining process to make 
fuel should be excluded from the definition of solid waste under 
RCRA.1
---------------------------------------------------------------------------

    \1\ See the proposed rule (specifically 60 FR 57752 to 57753) 
for a detailed discussion on the background to these regulatory 
issues.
---------------------------------------------------------------------------

    While these exclusions from the definition of solid waste are not 
available to hazardous secondary materials generated by, and used as 
ingredients in, the petroleum refining industry, these hazardous 
secondary materials, or the fuels produced from them, may be exempt 
from all regulatory requirements under 40 CFR 261.6(a)(3)(iii)-(v). 
These exemptions from regulatory requirements, however, did not resolve 
the jurisdictional debate involving the continued processing of 
hazardous secondary materials into fuels.
    Regarding this debate ,the plain reading of the statute has been 
supplemented by case law providing parameters within which to determine 
whether secondary materials being recycled are or are not solid wastes. 
In its decision in American Mining Congress v. EPA, (824 F. 2d 1177 
(D.C. Cir. 1987) (AMC I)), the D.C. Circuit Court held that EPA's rules 
defining the statutory term ``solid waste'' (RCRA Section 1004(27)) 
exceeded the Agency's statutory authority to the extent that the rules 
asserted jurisdiction over ``materials that are recycled and reused in 
an ongoing manufacturing or industrial process''

[[Page 42113]]

(Id. at 1186 (emphasis original)). The Court held that ``[b]ecause 
these materials have not yet become part of the waste disposal 
problem'' (Id.), they are not yet ``discarded'' within the meaning of 
Section 1004(27) and so cannot be considered to be ``solid wastes.''
    On January 8, 1988, EPA responded to the AMC I decision by 
proposing to exclude, from the regulatory definition of solid waste, 
oil-bearing petroleum residuals that are returned for further refining 
``as part of one continuous and ongoing process.'' (see 53 FR FR 525, 
Jan. 8, 1988). More specifically, EPA proposed to exclude oil-bearing 
residues from the refining process when those residues are generated 
on-site and reinserted on-site into the petroleum refining process 
(including the coker), provided that the residues were not 
speculatively accumulated or stored in a manner involving land 
placement.
    Subsequent decisions have established that the decision in AMC I is 
relatively narrow. In particular, courts have rejected the argument 
that ``potential reuse of a material prevents the Agency from 
classifying it as `discarded' '' (see, American Mining Congress v. EPA, 
907 F. 2d 1179, 1186 (D.C. Cir. 1990) (AMC II)). The proper test as to 
when, as a matter of law, the Agency is foreclosed from classifying a 
material as a solid waste is when a material is ``destined for 
immediate reuse in another phase of the industry's ongoing production 
process'' and that has ``not yet become part of the waste disposal 
problem'' (Id. at 1186 (emphasis original)). EPA retains considerable 
discretion in ascertaining how to apply this standard.
    For example, secondary materials generated by one industry and sent 
to another industry for reclamation could be classified as solid wastes 
(although EPA retains some discretion as to whether to make that 
determination) (see, American Petroleum Inst. v. EPA, 906 F. 2d 726, 
740-41 (D.C. Cir. 1990); Ilco v. EPA, 996 F. 2d 1126 (11th Cir. (1993); 
Owen Electric Steel v. Browner, 37 F. 3d 146 (4th Cir. 1994)). 
Similarly, secondary materials generated onsite, stored in surface 
impoundments, and reclaimed within the process which generated them 
could also be classified as solid wastes (see AMC II). EPA must 
normally justify determinations that a secondary material being 
recycled is not a solid waste by showing how the determination is 
consistent with RCRA's objective to ``establish a cradle-to-grave 
regulatory structure for the safe handling of hazardous wastes'' (see 
API, 906 F. 2d at 741).
    On July 28, 1994, EPA finalized parts of the January 8, 1988, 
proposal pertaining to petroleum refining industry operations. As noted 
in that final rule, post-AMC I decisions make clear that the statute 
affords EPA great latitude to set the jurisdictional parameters of 
RCRA. As a consequence, the July 28, 1994, final rule excluded a more 
limited set of materials and imposed greater restrictions on where the 
materials can be inserted within the petroleum refining process, than 
what was proposed on January 8, 1988. Specifically, in its January 1988 
proposal, EPA did not distinguish between recovered oil (i.e., oil 
reclaimed from secondary materials, such as wastewater, generated from 
normal petroleum refining, exploration and production, and 
transportation practices) and oil-bearing hazardous sludges, nor did it 
distinguish between the petroleum coker and other petroleum process 
units in defining the scope of the proposed petroleum refining 
exclusion. In the July 28, 1994, final rule, EPA limited the exclusion 
to recovered oil that is inserted into the petroleum refining process 
prior to distillation and catalytic cracking. Thus, it did not apply to 
recovered oil reinserted into the petroleum coker (see 40 CFR 
261.4(a)(12) and 59 FR at 38541-38542, July 28, 1994). In at least one 
respect, the July 28, 1994, final rule was somewhat broader than what 
was proposed. The final exclusion applied to materials generated from 
petroleum industry sources other than refineries, while the January 8, 
1988, rule proposed to exclude only oil-bearing materials generated at 
a refinery and reinserted into that refinery's refining process.
    After promulgation of the July 28, 1994, final rule excluding 
certain recovered oil, the EPA published a direct final rule on March 
26, 1996, to correct an inadvertent error in the regulatory text of the 
exclusion (see 61 FR 13103). Specifically, the direct final rule 
amended the words describing the point of insertion for recovered oil 
into the petroleum refining process (i.e., ``prior to crude 
distillation or catalytic cracking'') that was a condition of the 
exclusion. The original intent was to exclude recovered oil inserted 
into the refining process where the process removes at least some 
contaminants (which does not include cokers). After promulgating the 
exclusion, the Agency learned that delineating where recovered oil 
could or could not be inserted (and be excluded) using the words 
``prior to crude distillation or catalytic cracking'' was 
unintentionally restrictive, i.e., those operations were common 
examples but there were other refinery units where contaminants were 
removed as well. In addition to the amended regulatory text, the Agency 
also clarified that the recovered oil exclusion applied to oil 
recovered from shared wastewater treatment systems at petroleum 
refineries co-located with petrochemical facilities (see 61 FR 13104). 
Because the Agency received no adverse comment as of April 9, 1996, on 
the amended regulatory text, the direct final rule became effective on 
May 28, 1996.
    Today's final rule, which deals specifically with petroleum 
residuals, gives EPA the opportunity to address some larger, 
longstanding issues involving where the boundaries of RCRA should be 
drawn regarding jurisdiction over oil-bearing hazardous secondary 
materials which are generated by, and recycled within, the petroleum 
industry. Therefore, in addition to addressing specific regulatory 
issues that may arise as a result of a decision to list an individual 
petroleum waste stream, the Agency is issuing more comprehensive 
revisions to the RCRA regulations relating to regulatory jurisdiction 
over these materials when this type of intra-industry recycling occurs.

III. Summary of Proposal and Notice of Data Availability

A. Proposed Exclusions

    The proposed rule discussed the applicability of the definition of 
solid waste to the waste streams being evaluated for listing, but also 
related to a broader class of petroleum wastes. This is discussed 
briefly below.
1. Exclusion of Oil-Bearing Hazardous Secondary Materials Inserted Into 
Petroleum Refining, Including Petroleum Coking
    In the November 20, 1995, proposal, the Agency proposed to exclude 
oil-bearing secondary materials generated within the petroleum industry 
that are inserted into the petroleum coker (see 60 FR at 57754-57755). 
Generally, these secondary materials are generated as either residues 
of various refining processes or wastewater treatment systems which 
collect process waters (and oil) from the entire facility. (Note that 
these secondary materials, primarily wastewater treatment sludges, do 
not meet the definition of ``recovered oil'' because the contained oil 
is a small percentage of the total.) Secondary materials, such as 
wastewater treatment sludges, that contain a high percentage of oil are 
often processed to recover the oil for further refining (e.g., when 
there

[[Page 42114]]

is free oil). However, the typical oil recovery process (e.g., 
centrifugation) cannot recover all of the oil from these secondary 
materials, leaving a not insignificant amount of oil in the secondary 
materials that can only be recovered thermally.
    In conventional petroleum coking operations (also known as 
``delayed coking''), heavy oil-bearing feedstocks, typically bottoms 
from crude oil distillation or vacuum distillation (also referred to as 
``resids,'' representing the heaviest oil fraction of the crude oil 
feedstock) are placed into a coke drum. This material is then heated to 
high temperatures, thermally breaking or ``cracking'' the long-chain 
hydrocarbon molecules found in heavy oil feedstock into short-and 
middle-chain oil fractions that are then recovered, condensed, and sent 
for further refining into high-value fuel products. The remains of the 
heavy oil-bearing feedstock (which is primarily carbon and some 
inorganic contaminants) forms the coke product, typically used as a 
fuel.
    The last step of the conventional coking operation involves the 
injection of water to quench the coke product. Water is injected in the 
base of the coke drum and works its way up through the coke product, 
cooling the coke as it goes. This quenching also serves to remove light 
ends entrained within the coke product, similar to steam stripping. 
(The light ends recovered during the quenching process are likewise 
condensed and further refined into high-value fuel products.) Once cool 
enough, the coke product is typically removed from the coke drum using 
high pressure water drilling. For the purposes of this preamble 
discussion, it is important to distinguish between the two aspects of 
the coking operation. The first aspect, referred to in this preamble as 
``conventional coking,'' involves the recovery of light-end 
hydrocarbons from the resids feedstock and produces the coke product. 
The second aspect, referred to here as the ``quenching process,'' 
involves the injection of water into the high-temperature coke to cool 
it down after the conventional coking process.
    In the preamble discussion in the November 20, 1995, proposal, the 
Agency presented its determination that the petroleum coker is an 
integral part of the petroleum refinery process, with recovered middle-
and light-end hydrocarbons as its primary product and petroleum coke as 
a co-product. Based on the information on hand comparing the 
composition of oil-bearing hazardous secondary materials to typical 
feedstocks to the coker, and the fact that the coke produced using oil-
bearing hazardous secondary materials demonstrated no significant 
increase in hazardous metals concentrations, the Agency proposed to 
exclude such oil-bearing secondary materials when used in the 
production of petroleum coke. EPA believed this exclusion was further 
justified because the hazardous secondary materials are managed in a 
manner to prevent release, commensurate with management of nonhazardous 
oil-bearing feedstocks. (See 60 FR 57754-57755). In addition, the 
proposed exclusion was conditioned on there being no speculative 
accumulation or land placement (thus ensuring that the secondary 
materials would not be stored such that they could become part of the 
waste disposal problem), and that the coke product itself not exhibit a 
characteristic of hazardous waste, which, along with existing product 
specifications, would serve to ensure that the quality of the coke 
product would not degrade through the use of hazardous secondary 
materials such that it would become part of the waste disposal problem.
    At the time of the proposal, the Agency did not distinguish between 
oil-bearing hazardous secondary materials used in either of the two 
aspects of the coking operations, i.e., in the conventional coking 
process (where secondary materials would be used as feedstocks) or 
during the quenching process (where secondary materials are mixed with 
water and injected into the coke during the quenching process). While 
the Agency was aware that oil-bearing hazardous secondary materials 
were being used in the quenching process at some refineries, the 
primary focus and intent of EPA's proposed exclusion was for secondary 
materials used as feedstock in the conventional coking process, with a 
secondary consideration being whether these secondary materials 
legitimately could be used in the quenching process. As the Agency 
learned through comments received, the hazardous secondary materials in 
question (i.e., listed hazardous wastes generated by petroleum 
refineries) are rarely, if indeed ever, used as feedstock along with 
the resids. EPA, therefore, has since focused its attention on the role 
of oil-bearing hazardous secondary materials in the quenching process, 
maintaining the key consideration that the exclusion is only intended 
for oil-bearing hazardous secondary materials used in a manner 
consistent with the main production purpose of the coking process, 
i.e., the recovery of light-end hydrocarbons for further refining and 
the production of a marketable coke product.
2. Recovered Oil From Associated Petrochemical Facilities
    In the November 20, 1995 proposal, EPA proposed to add an exclusion 
at 40 CFR 261.4(a)(13) for recovered oil 2 that is generated 
by certain organic chemical industry facilities and inserted into 
petroleum refining processes provided that certain conditions are met 
(i.e., the petrochemical recovered oil is not stored in a manner 
involving placement on the land, or accumulated speculatively before 
being recycled) (see 60 FR at 57755. The proposed exclusion only 
applied to petrochemical recovered oil from organic chemical 
manufacturing facilities that were within the SIC code 2869, and was 
further limited to situations where the petrochemical and petroleum 
refinery facilities were either co-located, or under common ownership 
(co-owned). (Id).
---------------------------------------------------------------------------

    \2\ Recovered oil, as defined within the context the exclusion 
from the definition of solid waste promulgated in the July 28, 1994, 
final rule, includes materials that are primarily oil and that are 
recovered from any phase of petroleum exploration, production, 
refining, and transportation related thereto. Oil recovered from 
petrochemical facilities associated with petroleum refineries, 
whether from shared wastewater treatment systems at co-located 
facilities, or from other ``dry'' streams recovered from 
petrochemical process units, are referred to here as ``petrochemical 
recovered oil.''
---------------------------------------------------------------------------

    As described in the proposed rule, the recovered oil exclusion that 
was promulgated in the July 28, 1994, final rule did not apply to oil 
from organic chemical industry operations except in cases where 
petrochemical and petroleum refining operations share a common 
wastewater treatment system. In these instances, because a portion of 
the oil recovered during wastewater treatment and returned to petroleum 
refining originates from organic chemical manufacturing, some industry 
representatives questioned whether a ``petroleum industry'' exclusion 
would apply. However, because of the predominance of petroleum refining 
wastewaters in the shared wastewater treatment systems, and the degree 
of integration between these facilities, the Agency believed that it 
was appropriate to apply the July 28, 1994, recovered oil exclusion to 
the oil recovered from shared petrochemical and petroleum refining 
wastewater treatment systems. (see 61 FR at 13104). The EPA 
subsequently became aware that some petrochemical facilities recover 
oil from their process streams in a manner distinct from wastewater 
treatment operations and send this material (so-called ``dry'' 
hydrocarbon streams) to

[[Page 42115]]

petroleum refineries for insertion into the refining process. In some 
cases these hydrocarbon materials might or might not be viewed as solid 
wastes when returned to petroleum refining operations as feedstocks in 
producing the normal slate of refinery produced fuels. After 
promulgation of the July 28, 1994, rule, EPA received information from 
the chemical manufacturing industry indicating that these ``dry'' 
hydrocarbon streams recovered from their operations are comparable to 
oil recovered from petroleum refining operations, i.e., are chemically 
comparable to the recovered oil already excluded from being a solid 
waste. As explained in more detail in the proposed rule, the exclusion 
for petrochemical recovered oil was therefore based upon two specific 
arguments raised by both the chemical manufacturing and petroleum 
refining industries. First, knowledge of the composition of these 
petrochemical recovered oil streams is very important because of the 
potential for adverse impacts on both refinery operations (e.g., 
equipment corrosion, catalyst fouling) and product quality (e.g., 
introduction of contaminants that degrade motor fuels) if these streams 
contain constituents not typically encountered in normal refinery 
feedstocks. Second, analytical data the Agency received prior to 
proposal supported industry's premise that recovered oil from 
petrochemical operations is similar in composition to that from 
petroleum refining, and is therefore suitable for insertion into the 
petroleum refining process.3 EPA based the proposed 
exclusion for petrochemical recovered oil on a very limited set of data 
from integrated petrochemical and petroleum refineries that were either 
co-located or co-owned, and EPA believed that this was a typical 
arrangement for the return of these hydrocarbon streams to petroleum 
refineries (see 60 FR at 57756). In the proposal, EPA solicited 
additional data which could support broadening the exclusion to 
recovered oil from other SIC codes representing other types of 
associated chemical manufacture (e.g., plastics and resins, synthetic 
rubber, cyclic crude and intermediate producers). (Id).
---------------------------------------------------------------------------

    \3\ September 13, 1995, letter to Becky Daiss (EPA Office of 
Solid Waste) from Michael W. Steinberg (Morgan, Lewis & Bockius).
---------------------------------------------------------------------------

3. Use of Spent Caustics as Feedstock
    EPA proposed an exclusion from the definition of solid waste that 
would clarify that spent liquid treating caustics from petroleum 
refineries used as feedstock in the manufacture of naphthenic and 
cresylic acid products are not solid wastes. EPA believed that, when 
used in this manner, spent caustic is a valuable commercial feedstock 
that is used in the manufacture of commercial chemical products. 
Therefore, EPA proposed to add a new Sec. 261.4(a)(14) to exclude spent 
caustic when used in this manner.

B. Proposed Listing Decisions

1. Summary of Proposed Decisions
    EPA evaluated 14 wastes (the consent decree ``listing residuals'') 
in the petroleum refining industry, proposing to list 3 of these wastes 
as hazardous and not the other 11 wastes. Further general background 
for this rule is provided in the preamble to the proposed rule at 60 FR 
57748-57749. As a result of numerous comments on the proposed rule, EPA 
conducted additional analyses for these wastes, resulting in the 
Agency's publishing a Notice of Data Availability (NODA) on April 8, 
1997 (62 FR 16747). This Section summarizes the issues raised in the 
proposed rule and the following Section describes the NODA.
    The Agency proposed to list as hazardous the following three 
wastes:

K170--Clarified slurry oil storage tank sediment and/or in-line filter/
separation solids from petroleum refining operations.
K171--Spent hydrotreating catalysts from petroleum refining operations. 
(This listing does not include ceramic support media.)
K172--Spent hydrorefining catalysts from petroleum refining operations. 
(This listing does not include ceramic support media.)

    The Agency proposed not to list as hazardous the following eleven 
residual categories:

 Crude oil storage tank sediment
 Unleaded gasoline storage tank sediment
 Off-specification product and fines from thermal processes
 Catalyst from reforming
 Catalyst from sulfuric acid alkylation
 Sludge from sulfuric acid alkylation
 Hydrofluoric acid alkylation sludge
 Spent caustic from liquid treating
 Catalyst and fines from catalytic cracking
 Catalyst from sulfur complex and hydrogen sulfide removal 
facilities
 Sludge from sulfur complex and hydrogen sulfide removal 
facilities.

EPA also noted that its decision not to list crude oil storage tank 
sediment was a close call, and that the Agency may choose to list this 
waste as K169, depending on further evaluation of the data and 
comments.
    The proposed listing determinations were based on the Agency's 
evaluations at the time as to whether the wastes met the criteria in 40 
CFR 261.11(a) for listing wastes as hazardous. EPA assessed and 
considered the factors contained in these criteria primarily by 
incorporating them as elements in a risk assessment. A detailed summary 
of the risk assessment methodology is found in the preamble to the 
proposed rule, Section III.F, ``Description of Health and Risk 
Assessments'' (60 FR 57756-57762). EPA's view at the time of proposal, 
the applicability of the risk assessment to particular waste streams, 
and the proposed reasoning for the listing decisions are found in 
Section III.G., ``Waste-Specific Listing Determination Rationales'' (60 
FR at 57762-57776).
    EPA also proposed a number of exemptions for the wastes proposed 
for listing, described below.

Headworks Exemption

    In the proposal, EPA noted that some refineries manage the wastes 
EPA proposed for listing in their wastewater treatment system, while 
and others may scour residual sludge of the wastes proposed for listing 
during vessel cleaning or tank washing into the refinery wastewater 
treatment system. A consequence of listing these wastes as hazardous 
would be to cause all wastewaters and wastewater treatment sludges to 
be derived from those wastes.
    The Agency noted in the proposal that, provided the residuals 
derived from the wastes proposed for listing are discharged to the oil 
recovery sewer system, the residuals carried into the wastewater system 
would be removed during primary treatment as sludges or other wastes 
that are already regulated hazardous wastes (e.g., K048, K051, F037, or 
F038). Accordingly, the Agency proposed not to include these 
wastewaters in its listing determinations and to modify an existing 
regulation at 40 CFR 261.3(a)(2)(iv) to provide that these wastewaters 
would not be considered hazardous wastes. This exemption, known as the 
``headworks exemption,'' was discussed in the preamble for the proposed 
rule at 60 FR 57750 and 57781. The proposal noted that the exemption 
would apply to wastewaters containing clarified slurry Oil (CSO) 
sediment and, if EPA decided to list crude oil storage tank sediment in 
the final rule, this waste as well.

Exemption for Catalyst Support

    Upon removal from catalyst beds and/or during catalyst regeneration 
or reclamation, spent catalysts are separated from the support media 
that

[[Page 42116]]

are used in the catalytic reactors to optimize mixing and flow within 
the reactor beds. The Agency proposed an exclusion from RCRA regulation 
(under 40 CFR 261.3(c)(2)(ii)) for these support media because the 
support media are generally inert ceramics, separate from the catalyst, 
and commonly managed separately.

Third Party Recycling of Spent Petroleum Catalysts

    Spent hydrotreating and hydrorefining catalysts, two of the wastes 
proposed for listing (as K171 and K172, respectively), are frequently 
regenerated for reuse or reclaimed off-site to recover nonprecious 
metals (e.g., nickel, molybdenum, cobalt, and vanadium) and other 
compounds sold as products (i.e., aluminum sulfate derived from the 
alumina substrate material).
    In the proposed rule preamble in Section III.J.1., ``Third Party 
Regeneration/Reclamation of Spent Petroleum Catalysts'' (60 FR 57781), 
EPA proposed to clarify the regulatory status of units that regenerate 
or reclaim these catalysts. The proposal would have clarified that 
these units are specifically excluded from regulation as industrial 
furnaces under EPA's boiler and industrial furnace (BIF) rules at 40 
CFR Part 266, Subpart H. The proposed clarification was based on a 
number of factors, including EPA's view that the units differed from 
those considered for the BIF rule and the Agency's general view that it 
did not want to impose an unnecessary regulatory burden that may serve 
to discourage environmentally safe recycling of spent petroleum 
catalysts.
    The proposal also stated, however, that EPA had not fully evaluated 
the prevalence and adequacy of existing emission controls and the 
potential for uncontrolled emissions of toxic organic compounds, toxic 
metals, and particulate matter from spent hydrotreating and 
hydrorefining catalysts. Accordingly, the Agency stated that if it 
found that emissions from these units pose a threat to human health and 
the environment, it would reconsider the proposed clarification of the 
BIF rule and even could determine that the rule should, instead, be 
amended to specifically apply to spent petroleum catalyst recovery 
units. Thus, EPA solicited comment on the adequacy/efficiency of 
existing controls and data quantifying the levels emitted of hazardous 
air pollutants (HAPs) regulated under RCRA and/or section 112 of the 
Clean Air Act Amendments. The Agency indicated that it had made a 
preliminary finding that these units are already equipped with 
pollution controls comparable to those required under the BIF rule such 
that further regulation may be unnecessary.

Application of the Existing Exclusion for Spent Sulfuric Acid

    As described in the proposal, EPA previously excluded from the 
definition of solid waste spent sulfuric acid used to produce virgin 
sulfuric acid (40 CFR 261.4(a)(7)). The Agency reexamined this 
exclusion as it pertains to sulfuric acid used as a catalyst in 
refinery alkylation processes and found no reason to change the 
existing regulatory structure.
2. Summary of Proposed Risk Assessment Approach
    The proposed rule preamble describes in detail the various risk 
assessment analyses EPA carried out to determine the potential risk 
that might arise from the disposal of the refining wastes under 
consideration in this rule (see 60 FR at 57756-57762). In carrying out 
the modeling for these assessments, EPA used available data it 
collected for this industry, supplemented by data gathered from surveys 
of waste management practices (e.g., EPA's National Survey of Solid 
Waste (Municipal) Landfill Facilities, 1988, in the docket). The Agency 
also used information gathered in a questionnaire prepared under RCRA 
3007, hereafter referred to as the ``3007 Questionnaire,'' and site 
visits designed to examine the waste characteristics, waste management 
practices, and potential pathways for release and exposure.
    While EPA used this empirical data as much as possible in its risk 
assessment, the Agency nevertheless found that data gaps existed in the 
available information. Therefore, EPA also used other generic input 
parameters in the fate and transport models used to estimate the risk a 
waste might present under management scenarios known or likely to 
occur. The Agency used available data to develop input parameters for 
the concentrations and toxicity of constituents in the waste, the 
mobility and fate of such constituents in different disposal scenarios, 
likely exposure routes under these scenarios, and the location of 
various persons (``receptors'') that might be exposed. These receptors 
might be persons who consume contaminated groundwater, breathe air 
containing contaminants, or ingest contaminated soil or food.
    EPA considered what waste management scenarios to model, based on 
existing and potential practice in the refinery industry. Also 
important to the risk analyses are the volumes of wastes disposed and 
the potential for constituents in the waste to be released. Total 
volumes of waste were derived by multiplying the amount of wastes 
disposed in any given year times the active life for the disposal unit 
(how long a disposal unit accepts waste before closure). The fraction 
of the waste in the disposal unit (waste fraction) was derived from the 
total volume of a waste placed in the unit and the unit's capacity. 
While various waste management practices were considered, the Agency's 
modeling focused primarily on potential releases from waste volumes 
sent to nonhazardous (Subtitle D) landfills and land treatment units 
(LTUs), both on and off the refinery site (on-site and off-site units). 
For on-site, units EPA used the data on unit size available from the 
3007 Questionnaire. For off-site landfills, EPA used generic data 
available for Subtitle D unit size available from surveys of industrial 
and municipal waste management facilities.
    To estimate the significance of any potential releases of 
constituents from the disposal units and the potential for exposure to 
people or the environment, EPA first considered the mode of migration 
out of the landfill or LTU. The exposure of most concern for landfills 
arises from the release of constituents from the waste to groundwater. 
Other exposure routes were considered only in preliminary analyses, and 
did not present significant risks. EPA used the Toxicity Characteristic 
Leaching Procedure (TCLP) to estimate the mobility of constituents in 
leachate that may be released from a landfill to groundwater. EPA also 
considered the potential for oil in the wastes to facilitate release 
and transport of constituents from landfills by ``oil-phase flow.'' 
Such facilitated release might occur if free oil in wastes, potentially 
containing hazardous constituents, migrated from landfills to 
groundwater. However the Agency's analysis showed this type of 
facilitated release was not likely. For LTUs, the wastes are mixed with 
soils on the surface of the unit. Potential exposure routes of most 
concern for land treatment arose from the transport of contaminated 
soils to receptors by both wind-borne air releases, and the erosion/
run-off caused by precipitation. Groundwater risks from LTUs were not 
found to be significant.
    To model the transport of constituents to receptors, EPA typically 
used data available from surveys to locate the likely exposure point. 
Thus, to assess potential groundwater exposures near landfills, EPA 
used national surveys of landfills, which included data regarding

[[Page 42117]]

the distance from landfill units to nearest drinking water well. For 
LTUs, EPA used surveys of the distance of residences from such disposal 
units. Where appropriate, EPA attempted to consider information related 
to the biodegradation some constituents may undergo in the unit or 
after release into the environment.
    The Agency used comparisons between concentrations in the 
environment and health-based levels (HBLs) to evaluate the potential 
health impacts of toxic constituents in environmental media, such as 
soil or groundwater. For noncarcinogenic constituents, the HBL is the 
concentration in the media which results in an exposure level equal to 
the ``reference dose;'' the reference dose is EPA's measure of an 
acceptable daily intake for a specific chemical. For carcinogenic 
constituents, the HBL is the concentration in the media that results in 
an exposure level corresponding to a specified cancer risk level. EPA 
applied carcinogenic potency estimates (Carcinogenic Slope Factors) to 
calculate specific risk levels. The risk assessment results are given 
in terms of individual risk, i.e., the carcinogenic risk is described 
in terms of the additional incidence of cancer that may occur in an 
exposed population. A risk of 1  x  10-5 (which will be 
presented in this document as 1E-5), for example, corresponds to a 
probability of one additional case of cancer for every 100,000 people 
exposed. The Agency also evaluates carcinogenic constituents by 
directly calculating the estimated cancer risk level resulting from a 
given concentration of the constituent in the environmental media.
    In the modeling for risk assessment, EPA varied some of the more 
sensitive parameters to examine the range or potential risks presented 
by the wastes studied. Key parameters included the area of the waste 
disposal units, waste volumes disposed, constituent concentrations in 
the wastes, and the distances to receptors. Varying several of these 
key parameters at one time can have a large cumulative impact on the 
risk results. In view of the variation in individual exposure risks 
that could exist for the wastes, EPA performed a number of different 
types of risk and sensitivity analyses. First, the Agency completed a 
``bounding analysis'' in which the key input parameters were set to 
produce a worst-case scenario. This analysis was intended to purposely 
overestimate exposure to establish an upper bound for risks. (See the 
EPA guidance memo entitled, Guidance on Risk Characterization for Risk 
Managers, 1992; docket number F-95-PRLP-S0423, hereafter known as the 
Habicht memo, 1992.) Thus, all key parameters were set to their maximum 
or ``high-end'' values (typically the 90th percentile point on the 
distribution of values available for each parameter). If the risks 
resulting from the bounding analysis were below the level of any 
potential concern (i.e., carcinogenic risks below 1E-6 and hazard 
quotients (HQs) less than one), the wastes and/or waste constituents 
were removed from further consideration.
    For wastes and constituents that did not ``bound out,'' EPA ran a 
double ``high-end'' deterministic sensitivity analysis, which produced 
point estimates of risk based on use of single values for input 
parameters. In this method, key input parameters were varied between 
the central tendency value (50th percentile) and the high-end (90th 
percentile) values. The point estimate in which all variables were set 
at central tendencies was assumed to be the central tendency risk 
estimate. The highest risk estimate for any combination of double high-
end variables (with all other variables set at central tendency) was 
assumed to be the high-end estimate of risk. The high-end risk estimate 
was presumed by the Agency to be a plausible estimate of individual 
risk for those persons at the upper end of the risk distribution. The 
intent of these descriptors is to convey estimates of exposure in the 
upper end of the distribution (i.e., above the 90th percentile) and to 
avoid estimates that are beyond the true distribution.
    After completing these various analyses, EPA compared individual 
exposure levels to HBLs for the toxic constituents to determine whether 
particular wastes are candidates for listing. In keeping with 
discussions of the Agency's listing policy (see Dyes and Pigments 
Listing, 59 FR at 66075-66078), EPA used a risk level of concern of 1E-
5, and/or HQs of one, to determine which wastes are considered initial 
candidates for listing. To make listing determinations, EPA then used a 
weight-of-evidence approach that considers the risk estimates along 
with other evidence related to the factors described in 40 CFR 
261.11(a)(3).
    Based on EPA's analysis for the proposed rule, the exposure pathway 
of concern for the landfill scenario was ingestion of groundwater 
contaminated by constituents leaching out of the unit. For the land 
treatment scenario, the potential release of wastes by air or run-off 
yielded exposure for nearby residents and home gardeners via soil 
ingestion and for other subpopulations (fishers, farmers) through 
indirect exposures, i.e., via ingestion of contaminated fish and food. 
These analyses led to the proposed listing decisions as explained in 
the preamble to the proposed rule.

C. Notice of Data Availability

    Many issues were raised by commenters on the proposed rule causing 
EPA to rethink its analyses and the risk assessments. These issues are 
discussed in the April 8, 1997 NODA (62 FR 16747) and the accompanying 
support documents. EPA conducted new risk assessments for both 
groundwater and non-groundwater pathways, in addition to analyses for 
the headworks exemption, recycled hydrocarbon-bearing materials, and 
leaching of oily wastes. This new information was presented for 
comment. At the time, EPA believed that the additional analyses tended 
to support the proposed rule and did not propose any new listing 
decisions. Important additional analyses provided in the NODA are 
briefly described below.
    The NODA provided revised ``high-end'' analyses for the landfill 
and LTU scenarios. In the groundwater analysis, EPA completed more 
detailed sensitivity analyses and Monte Carlo analysis to better define 
high-end risks, and determine how close the high-end risks, were to the 
90th percentile.
    The Agency has been using Monte Carlo modeling methodology in 
various rulemakings for many years. Monte Carlo modeling is a 
statistical technique that can be used to simulate the effects of 
natural variability and informational uncertainty which often accompany 
many actual environmental conditions. It is a process by which an 
outcome is calculated repeatedly for many situations, using in each 
iteration randomly selected values from the distributions of each 
variable input parameter. When compared with alternative approaches for 
assessing parameter uncertainty or variability, the Monte Carlo 
technique has the advantages of general applicability and no inherent 
restrictions on input distributions or input-output relationships. 
Monte Carlo application results can also be used to calculate 
uncertainty, and can be used to quantitatively specify the degree of 
conservativeness used. However, potential limitations also exist when 
applying Monte Carlo techniques in modeling efforts. Variability 
(inherent variation in a measure over time and space) and uncertainty 
(lack of knowledge) may be difficult to distinguish within 
applications. Also, correlations among the various data parameters that 
have not been accounted for in the modeling may

[[Page 42118]]

distort conclusions. Finally, sufficient data must generally be 
gathered to ensure that acceptable statistical representations and 
sensitivity analyses within Monte Carlo applications can be properly 
prepared.
    The Monte Carlo simulations used in this rulemaking assessed the 
full distributions of critical input data (e.g., distance to well, 
waste volumes, landfill area) to randomly generate receptor well 
concentrations of key constituents for certain landfill situations, and 
then combined the results from many runs (10,000) to produce a 
probability distribution of risks. EPA was then able to choose points 
along the probability distribution of risk for comparison to the high-
end analysis. For example, a risk that corresponds to the 95th 
percentile for a specific waste constituent in a landfill means that 
the risk would be below this level in 95 percent of the runs. EPA also 
modified all groundwater risk analyses to add risks due to noningestion 
exposures (e.g., via inhalation and dermal absorption during showering) 
to the ingestion risks that may arise from residential use of 
groundwater.
    Further groundwater analysis was also performed in response to 
comments on the proposed rule that noted EPA had used waste input data 
(TCLP) that exceeded the existing Toxicity Characteristic (TC) 
threshold and that disposal in nonhazardous landfills was unlikely for 
such wastes. This additional groundwater analysis limited the TCLP 
input used in modeling, such that none of the input levels exceeded the 
TC threshold, to examine the impact on risk results (the ``TC-capped'' 
analysis).
    In the nongroundwater analysis presented in the NODA, EPA 
incorporated several modifications for LTUs, including: limiting wastes 
volumes modeled to nonhazardous waste; limiting unit characteristics 
used (e.g., unit area) to nonhazardous units; correcting an error in 
the air dispersion modeling; minor changes to the models used to 
estimate release and transport of contaminated soil to off-site 
receptors; and incorporating further biodegradation of key constituents 
after they travel off-site.
    The appropriateness of the TCLP for petroleum wastes containing oil 
and the potential for oil and other materials to facilitate release and 
transport of wastes in landfills were major areas of comment. EPA 
provided additional information in the NODA to respond to this issue, 
including; analysis of the oil content of the waste samples, the 
prevalence of disposal of oily waste in landfills, analysis using 
alternative leaching procedures, and calculated TCLP leaching 
efficiencies for organic constituents in the wastes.
    EPA received comments on its choice of management practices modeled 
and the way volumes were allocated. Some commenters also suggested that 
volumes of wastes beyond those under consideration in this rule should 
have been considered in various codisposal scenarios for both landfills 
and LTUs. In response, EPA presented risk analyses in the NODA that 
assessed the potential impact of codisposal of the listing residuals 
with certain other refinery wastes.
    In the NODA, EPA presented additional analyses to address comments 
on the headworks exemption for CSO storage tank sediment. While some 
commenters did not favor the exemption due to potential impacts on 
downstream wastes, other commenters argued the exemption should be 
expanded to exclude wastewater from spent hydrotreating and 
hydrorefining catalysts, the other two wastes EPA proposed for listing. 
The Agency evaluated the potential impact of including wastewater from 
these three wastes in the headworks exemption, and presented the 
results in the NODA that showed excluding them would not result in any 
significant risks in the downstream wastes.
    Comments on the proposal suggested that the active life for a 
landfill used by EPA was too short. This parameter is important because 
it determines the total waste volume in the modeled landfill, which is 
one of the critical input parameters for the model. To respond to this 
comment, EPA presented data in the NODA for on-site landfills to show 
that the data in the 3007 Questionnaire supports the Agency's 
assumption of a 20-year active life.
    The NODA also presented other information related to: the potential 
impact of the oil-bearing residuals exclusion on coke product, the 
potential for concurrent exposure to releases from landfills and LTUs, 
and the applicable UTS under the Land Disposal Restrictions program.

IV. Changes to the Proposed Rule

    As a result of comments on the proposed rule and NODA analyses, 
certain modifications were made to the listing determinations and 
definition of solid waste exclusions. These changes and the subsequent 
scope of today's final action are described below. Detailed reasoning 
behind these changes is provided in Section V.

A. Definition of Solid Waste Exclusions

1. Exclusion of Oil-Bearing Hazardous Secondary Materials Inserted Into 
Petroleum Refining, Including Petroleum Coking
    Today, the Agency is finalizing a portion of the proposed exclusion 
for oil-bearing hazardous secondary materials recycled within the 
petroleum industry. Specifically, oil-bearing hazardous secondary 
materials generated within the petroleum refining sector (i.e., SIC 
code 2911, petroleum refineries) are excluded under today's rule when 
they are to be inserted into the petroleum refining process, including 
into the petroleum coker, provided they are not placed on the land or 
speculatively accumulated before being so recycled. As discussed below, 
this exclusion applies to any oil-bearing material generated at a 
petroleum refinery, including oil-bearing wastes currently regulated as 
listed hazardous wastes (e.g., K048-K051), and including refinery 
wastes newly listed under today's rulemaking that are suitable for 
insertion into normal petroleum refining operations. EPA is not 
finalizing the proposed exclusion for oil-bearing hazardous secondary 
materials generated elsewhere within the petroleum industry, such as 
from petroleum exploration and production sites, bulk crude oil 
storage, and petroleum industry-related transportation facilities. 
However, the pre-existing recovered oil exclusion promulgated July 28, 
1994, is still being retained under today's rule with respect to 
recovered oil generated from within the petroleum industry. EPA is also 
modifying an existing petroleum-industry listing (F037) to make it 
apply to discarded residues generated from processing or recycling 
petroleum-industry listed hazardous wastes that are otherwise excluded 
under today's provision.
    The Agency notes that this exclusion will have little net effect on 
the materials or units involved. Under the current regulatory program 
(i.e., prior to today's amendments), oil-bearing secondary materials 
may legitimately be recycled into a petroleum coker. While such 
materials may be considered solid and hazardous wastes, the coking unit 
would be a recycling unit exempt from permitting requirements (40 CFR 
261.6(c)(1)). The coke product is exempt under 40 CFR 261.6(a)(3)(v), 
provided the secondary materials are generated by the same ``person,'' 
defined in 40 CFR 260.10 as ``an individual, trust, firm, joint stock 
company, Federal agency, corporation (including a government 
corporation), partnership, association,

[[Page 42119]]

State, municipality, commission, political subdivision of a State, or 
any interstate body,'' and the petroleum coke does not exhibit a 
characteristic of hazardous waste. The oil recovered in the coking 
operation (including both conventional coking and the quenching 
process) which is used to produce fuels is excluded from the definition 
of solid waste as recovered oil under 40 CFR 261.4(a)(12).
2. Recovered Oil From Associated Petrochemical Facilities
    In today's final rule, EPA is finalizing a somewhat narrower 
exclusion than originally proposed. Specifically, EPA proposed to 
exclude recovered oil from ``associated organic chemical manufacturing 
facilities'' where such facilities were defined as those within the SIC 
code 2869 and either co-located or under common ownership with the 
petroleum refinery receiving the petrochemical recovered oil. In 
today's rule, EPA is dropping ``under common ownership'' from the 
definition of ``associated organic chemical manufacturing facility'' 
for reasons discussed later. In addition, EPA is limiting the 
applicability of the final exclusion to petrochemical recovered oils 
that are hazardous only because they exhibit the characteristic of 
ignitability (as defined in 40 CFR 261.21) and/or toxicity for benzene 
(40 CFR 261.24, waste code D018). Finally, in today's rule, EPA is also 
excluding petrochemical recovered oil generated at facilities where the 
primary SIC code is 2869, but where three other classifications of 
chemical manufacturing units commonly occur at these vertically-
integrated facilities (SIC codes 2821, 2822,2865).
3. Use of Spent Caustic as Feedstock
    Today EPA is finalizing the exclusion proposed for spent caustic 
solutions from petroleum refining when used as feedstocks to produce 
cresylic or naphthenic acid. This new exclusion is being added at 40 
CFR 261.4(a)(19).

B. Listing Determinations

    Table IV-1 presents a summary of changes to the proposed listing 
decisions. Detailed bases for today's final listing determinations are 
discussed in Section V.C for each specific waste.

                                             Table IV-1.--Comparison of Proposed and Final Listing Decisions                                            
--------------------------------------------------------------------------------------------------------------------------------------------------------
            Waste Stream                        1995 Proposal                    Final decision                         Basis for decision              
--------------------------------------------------------------------------------------------------------------------------------------------------------
Hydrotreating Catalyst..............  List............................  List...........................  Groundwater risks due to benzene and arsenic   
                                                                                                          from landfill disposal; pyrophoric and self-  
                                                                                                          heating nature of waste.                      
Hydrorefining Catalyst..............  List............................  List...........................  Groundwater risks due to benzene and arsenic   
                                                                                                          from landfill disposal; pyrophoric and self-  
                                                                                                          heating nature of waste.                      
CSO Storage Tank Sediment...........  List............................  List...........................  Nongroundwater risks due to PAHs from land     
                                                                                                          treatment disposal; some groundwater risks due
                                                                                                          to benzene from landfill disposal; high PAH   
                                                                                                          and oil content.                              
Crude Oil Tank Sediment.............  No-list.........................  List...........................  Groundwater risks due to benzene from landfill 
                                                                                                          disposal; PAH and oil content.                
Unleaded Tank Sediment..............  No-list.........................  No-list........................  Some groundwater risks due to benzene from     
                                                                                                          landfill disposal, but no significant PAH or  
                                                                                                          oil content; relatively low volume.           
HF Alkylation Sludge................  No-list.........................  No-list........................  Relatively low groundwater risks due to benzene
                                                                                                          from landfill disposal; no significant PAH    
                                                                                                          content; benzene found in only one TCLP       
                                                                                                          sample.                                       
Off-specification Product & Fines...  No-list.........................  No-list........................  Low groundwater risks due to PAHs from landfill
                                                                                                          disposal; PAHs only found in one TCLP sample  
                                                                                                          near detection limit.                         
Other Wastes \1\....................  No-list.........................  No-list........................  No significant risks from any pathway.         
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Includes seven wastes: Catalyst from Sulfuric Acid Alkylation, Sludge from Sulfuric Acid Alkylation, Spent Caustic from Liquid Treating, Catalyst   
  and Fines from Catalytic Cracking, Sludge from Sulfur Complex and Hydrogen Sulfide Removal Facilities, Catalyst from Sulfur Complex and Hydrogen      
  Sulfide Removal Facilities, and Catalyst from Reforming.                                                                                              

    In response to additional comments submitted on the NODA, the 
Agency further examined the record and reconsidered the entire risk 
assessment and decisions for all the wastes under consideration. 
Commenters on the NODA provided detailed comments on the groundwater 
modeling approach used by EPA. Some commenters submitted their own 
groundwater modeling, purporting to show higher risks than EPA's 
evaluation for a number of wastes. While the commenters used the same 
model as EPA (EPACMTP), they adjusted key input values to increase 
landfill area, increase active life of landfills and resulting volume 
disposed, move the receptor well location to the middle of the plume of 
contamination, increase TCLP concentrations using simplifying 
assumptions, and increase volumes due to codisposal. To respond fully 
to critical issues raised in comments on the groundwater risk analysis, 
EPA decided to make modifications to some modeling assumptions and data 
inputs. EPA examined the impact of other suggestions by the commenters, 
but found these to be of no importance or did not agree that the 
changes were warranted. The changes to the modeling, and EPA's reasons 
for not accepting other suggestions, are discussed in detail in Section 
V.B.
    Specifically, in response to NODA comments, EPA decided that some 
revisions in the modeling assumptions were appropriate. Thus, the 
Agency performed additional risk analyses to reflect an increase in the 
active life for off-site landfills (which resulted in increased volume 
input to the modeling), and the use of off-site municipal landfill area 
distributions, rather than the areas for industrial landfills used 
previously. With these changes, the final revised high-end and Monte 
Carlo risks increased somewhat from those presented in the NODA for 
off-site landfills and are summarized in Table IV-2. Also, in 
conducting the Monte Carlo analysis for the NODA, the Agency made a key 
assumption concerning well location which was inconsistent with the 
assumption made for the high-end analysis (see discussion of receptor 
well location in Section V.B.6). Therefore, EPA performed further Monte 
Carlo analyses using well location assumptions consistent with the 
high-end analysis, and the results show that this also increases risks, 
such that the 95th percentile Monte Carlo risks are more comparable to 
the high-end risks. Finally, while reexamining the groundwater risk 
analysis for off-specification products and fines, EPA corrected errors 
in waste volumes and a

[[Page 42120]]

health-based level used for prior analyses.

(See Additional Groundwater Pathway Risk Analyses, 1998, in the public 
docket for this rule for details on the revised analyses.)
    The final risk results for off-site landfills, with the changes 
noted above, are summarized in Table IV-2 for wastes of concern. Other 
wastes either did not have significant risk in bounding analyses, or 
were not modeled for landfill disposal because the practice was not 
found.

                              Table IV-2.--Summary of Revised Groundwater Risks for Petroleum Wastes in Off-Site Landfills                              
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                     Revised risks \1\                      TC-capped risks \2\         
                                                                         -------------------------------------------------------------------------------
               Waste                             Constituent                                   Monte Carlo Risk                        Monte Carlo risk 
                                                                           High-end risk \3\     \4\  (95th%)        High-end risk          (95th%)     
--------------------------------------------------------------------------------------------------------------------------------------------------------
Clarified Slurry Oil Tank Sediment.  benzene............................  4E-06               2E-06               NC                  NC                
Hydrotreating Catalyst.............  benzene............................  1E-04               3E-05               3E-05               9E-06             
                                     arsenic............................  8E-05               2E-05               NC                  NC                
Hydrorefining Catalyst.............  benzene............................  7E-05               2E-05               3E-05               8E-06             
                                     arsenic............................  6E-04               4E-04               6E-04               4E-04             
Crude Oil Storage Tank Sediment....  benzene............................  4E-05               1E-05               3E-05               9E-06             
Unleaded Gasoline Storage Tank       benzene............................  3E-05               6E-06               2E-05               4E-06             
 Sediment.                                                                                                                                              
HF Alkylation Sludge...............  benzene............................  1E-05               2E-06               NC                  NC                
Off-Specification Product and Fines  benzo(a)anthracene.................  2E-06 \5\           1E-06               NC                  NC                
                                                                          5E-07 \6\           8E-07                                                     
Codisposal Scenario................  benzene............................  8E-06               3E-06               NC                  NC                
                                     arsenic............................  4E-06               2E-06               NC                  NC                
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Revised risk includes new inputs for active landfill life (30 yr.) and municipal landfill areas.                                                    
\2\ Input leaching rates were capped at TC regulatory levels for disposal in Subtitle D landfills (0.5 mg/L for benzene and 5.0 mg/L for arsenic); NC = 
  no change because TCLP values were already below TC levels.                                                                                           
\3\ Risks using high-end values for two most sensitive parameters, and remaining parameters kept at median values.                                      
\4\ Risks using Monte Carlo simulation runs at the 95th percentile level with well location restricted to plume.                                        
\5\ Estimated TCLP input assumed to be mean value.                                                                                                      
\6\ Estimated TCLP input assumed to be one high-end parameter.                                                                                          

    The nongroundwater risk results for land treatment are unchanged 
from those reported in the NODA (see 62 FR at 16753). However, in 
response to comment EPA performed a Monte Carlo uncertainty analysis 
for land treatment risks that supports the results presented in the 
NODA. See Section V.B of today's notice for further discussion of this 
issue.
    The revised groundwater risk assessment for landfills, in 
conjunction with the nongroundwater assessment for land treatment 
disposal presented in the NODA, continues to support the proposed 
listing of K170, K171, and K172. Therefore, EPA is promulgating these 
listings in today's final rule, with minor modifications to clarify the 
definition of the two spent catalysts (see Section V.C.3).

K171--Spent hydrotreating catalyst from petroleum refining 
operations, including guard beds used to desulfurize feeds to other 
catalytic units. (This listing does not include inert support 
media.)
K172--Spent hydrorefining catalyst from petroleum refining 
operations, including guard beds used to desulfurize feeds to other 
catalytic units. (This listing does not include inert support 
media.)

    In addition, EPA has determined that the available information and 
the revised groundwater risk assessment provides sufficient basis to 
list as hazardous crude oil storage tank sediment, and to have the 
waste designation of K169. The listing will read:

K169--Crude oil storage tank sediment from petroleum refining 
operations.

    All final listing determinations depend upon EPA's consideration 
and review of public comments submitted in response to the proposed 
determinations, issues raised in the NODA, and any other relevant 
information available to the Agency. The final determinations are based 
on the Agency's evaluations as to whether the wastes meet the criteria 
in 40 CFR 261.11(a) for listing wastes as hazardous. EPA has assessed 
and considered the factors contained in these criteria primarily by 
incorporating them as elements in the revised risk assessment, which is 
based on the methodology described in the preamble to the proposed rule 
and subsequent modifications described in this preamble and in support 
documents in the rulemaking record. EPA bases its final listing 
determinations on the entire rulemaking record, including applicable 
sections of the preamble to the proposed rule, additional analyses 
provided in the NODA, the Agency's responses to the comments on 
significant issues raised in the preamble to the proposal and the NODA, 
and all other relevant information available to the Agency.

C. Other Exemptions

1. Headworks Exemption
    EPA presented analysis in the NODA to support the headworks 
exemption for both wastewater associated with CSO tank cleaning and the 
expansion of the exemption to include water discharges from the clean-
out and turn around of hydrotreating and hydrorefining catalytic units. 
After considering all comments on these analyses, EPA has decided to 
promulgate the expanded headworks exemption. As noted in the proposal, 
EPA intended to include crude oil storage tank sediment in the 
exemption, if this waste was listed. Thus, EPA is also promulgating the 
exemption for K169 as well. To fully respond to all comments, EPA 
completed an analysis of the impact of the discharge of crude oil 
storage tank sediment to the wastewater treatment system, which 
demonstrates that the discharge is unlikely to adversely impact 
downstream wastes. This decision is discussed in V.D, and supporting 
analyses are presented in the docket for this notice.
    In amending the headworks exemptions under 40 CFR 
261.3(a)(2)(iv)(C), the Agency intends the exemption to apply to 
wastewaters from cleaning operations when these wastewaters reach the 
headworks of the wastewater treatment system. As noted

[[Page 42121]]

in the proposal, however, the exemption is not intended to allow the 
discharge of the entire waste stream (i.e., tank sediments or spent 
catalysts), but rather dilute waters generated during tank or unit 
clean-outs and dewatering operations.
2. Exemption for Catalyst Support
    The Agency is finalizing the proposed exemption (under 40 CFR 
261.3(c)(2)(ii)) for these support media because the support media are 
generally inert materials and commonly managed separately. EPA is 
clarifying the exemption so that it is no longer limited to ceramic 
material, based on comments indicating that other inert materials, such 
as stainless steel, are also used.
3. Third Party Recycling of Spent Petroleum Catalysts
    EPA does not believe at this time that it is appropriate to issue 
the proposed clarification to exempt, from permitting requirements 
under Part 266.100(b), third party units regenerating and reclaiming 
hydrotreating and hydrorefining spent catalysts. EPA is deferring to a 
later day any final decision on whether or not to clarify the BIF rule 
with respect to these wastes. In the meanwhile, EPA reiterates that 
nothing in today's rule (or indeed the proposal in this docket) changes 
the current RCRA status of facilities managing these hazardous wastes. 
(See Section V.E. for further discussion of this decision.)

V. Response to Comments and Rationale for Final Rule

    The Agency is responding in this preamble to the most significant 
comments received in response to both the notice of proposed rulemaking 
and the NODA. Other comments received by the Agency are addressed in 
the Response to Comments Background Documents that are available in the 
docket associated with this rulemaking.

A. Proposed Modifications to the Definition of Solid Waste

1. Exclusion of Oil-Bearing Hazardous Secondary Materials Inserted Into 
Petroleum Refining, Including Petroleum Coking
Role of the Petroleum Coker in the Petroleum Refining Process
    To determine RCRA jurisdiction, the Agency must differentiate 
between materials that are part of normal ongoing production activities 
and materials that are part of waste management, including recycling or 
treatment. Distinguishing waste management from normal production can 
sometimes be difficult when it involves hazardous secondary materials 
generated by certain production processes and used as feedstocks in 
other production processes within the same industry that produce a 
relatively low-value product (especially hazardous secondary materials 
that have sometimes been discarded in the past). (see 50 FR at 618-620, 
Jan. 4, 1985). Regarding the petroleum refining production process, 
classification of the coking operation has been historically 
troublesome in delineating production from waste management because it 
is not typical of other refining processes.
    Generally, and in the most basic of terms, petroleum refining 
processes serve to separate and remove hydrocarbon components out of a 
feedstream, in effect constituting a multi-stage process of separating 
valuable product materials from the contaminants (e.g., sulfur and 
metals) inherent in the original raw material (crude oil). In the 
coking process, however, the contaminants inherent in the crude oil 
feedstock are incorporated into the fuel product, along with the carbon 
that results from the thermal breaking of complex hydrocarbon chains 
into more valuable small- and middle-chain oil fractions (see detailed 
description of conventional coking versus the quenching process in 
Section III.A.1.).
    EPA first evaluated whether the conventional coking operation is a 
true production process because the crude oil distillation bottoms, 
i.e., resids, used as feedstock contain many of the unwanted 
contaminants in the original crude oil which end up in the coke product 
(a low-value fuel product, relative to the other fuel products produced 
by petroleum refining) and because a majority of the coke product is 
exported rather than being used within the United States. As stated 
earlier, this is not typical of a petroleum refining process producing 
a fuel product. Thus, an argument could be made that the petroleum 
coker is simply a means of disposing of unusable heavy oils and other 
contaminants associated with crude oil feedstocks (including hazardous 
heavy metals), while producing a relatively low-value fuel.
    However, the American Petroleum Institute (API) supplied the Agency 
with detailed information regarding the conventional coking operation, 
presenting a description of the physical processes involved in the 
coking process and the economic value of the overall coking operation 
to the refinery, as well as the feedstocks used and products produced. 
As discussed in the November 20, 1995, proposal preamble (60 FR at 
57754), the Agency has determined that the use of resids as feedstock 
to the petroleum coker is a legitimate production process whose main 
purpose is to thermally convert the heaviest crude oil fractions into 
light-end hydrocarbons (typically about 70 percent of the feedstock is 
recovered as lighter oil fractions) used as feedstocks for refinery 
processes that produce high-value fuel products. In many cases, the 
conventional coking operation is essential to the profitable production 
of petroleum products from heavier crude oil feedstocks, being a cost-
effective process for maximizing the amount of hydrocarbon that can be 
recovered from the crude oil feedstocks. The coke product itself may 
best be characterized as a co-product of the coking operation, while 
the principal products are the light ends that are returned to the 
refining process. Thus, the Agency is affirming that the conventional 
coking operation is a production process resids are normal feedstocks 
to this process and petroleum coke is a legitimate fuel product 
(although EPA in fact notes that high-grade petroleum coke meeting 
relatively exacting specifications is used for producing anodes for use 
in electric furnaces, such as for steel and aluminum manufacturing).
    However, the fact that the Agency considers the conventional coking 
operation to be a normal production process does not mean that any 
material introduced to the coking operation is, by definition, part of 
a normal production process. Indeed, when considering the regulatory 
status of hazardous secondary materials not typically used as 
feedstocks being introduced into such a process, the Agency must 
consider whether such use of the secondary materials is legitimate use 
in a production process, or rather is sham recycling where unwanted 
contaminants are being removed of under the aegis of an ostensible 
manufacturing operation. Typically, this is evaluated through a 
comparison to the normal feedstocks, with particular focus given to 
whether there are hazardous constituents contained in a hazardous 
secondary material that are not found in the normal feedstock materials 
for which it is substituting (see 50 FR at 638, Jan. 4, 1985). EPA 
received many comments relevant to the exclusion for the hazardous 
secondary materials inserted into the petroleum coker, especially the 
quenching process, both supporting and opposing to the exclusion. Much 
information, both anecdotal and analytical data, was received 
concerning various aspects of

[[Page 42122]]

the overall coking operation. This information included the constituent 
composition of the hazardous oil-bearing secondary materials at issue, 
the normal coker feedstocks, various aspects of the overall coking 
operation, the coke product, and the marketing of petroleum coke. The 
Agency made a very considered evaluation of all of the information 
provided in comment to the proposal, much of which was contradictory 
and difficult to confirm. The discussion below presents the Agency's 
reasoning in making its determination.
Use of Hazardous Secondary Materials in the Petroleum Coker
    The Agency evaluated information received on the role of oil-
bearing hazardous secondary materials in the coking operation. As 
discussed more below, the oil-bearing hazardous secondary materials 
typically put into the coker unit are unable to be processed via 
conventional coking because of their high water content (the water 
would volatilize and create unsafe pressures during the conventional 
coking process). Therefore, the Agency's evaluation centered around the 
role of these secondary materials in the quenching process, described 
in more detail in Section III.A.1. of today's preamble. In evaluating 
this information, the Agency's focus was to determine whether the use 
of oil-bearing hazardous secondary materials in the quenching process 
is consistent with the role of oil-bearing feedstocks in the 
conventional coking process, i.e., to provide hydrocarbon for further 
refining and to contribute carbon to the coke product. (EPA's reasoning 
is that it is the recovery of hydrocarbon and production of coke that 
is the intent of the overall coking operation, and thus the legitimate 
use of a hazardous secondary material in the quenching process should 
likewise contribute to this intent.) This evaluation compared not only 
the constituent make-up of the feedstocks to both conventional coking 
(resids) and to the quenching process (hazardous secondary materials), 
but also what physical/chemical processes occur in both aspects of the 
coking operation. The discussion that follows presents the Agency's 
evaluation.
    In comparing the typical hazardous secondary materials used in the 
quenching process (i.e., listed hazardous wastes, primarily wastewater 
treatment sludges) to the residues normally used as feedstocks to 
conventional coking, the oil content in the hazardous secondary 
materials is much lower (ranging from around 8 percent to 40 percent in 
the hazardous secondary materials to around 99 percent in the crude oil 
distillate bottoms), while the water content is much higher. The 
hazardous constituents (primarily heavy metals) in the secondary 
materials are measurably higher. However, as stated above, the 
hazardous secondary materials are not used in conventional coking, but 
rather are used in the quenching process. Therefore, a comparison of 
the hazardous secondary materials to the resids feedstock has limited 
value and is not dispositive for determining the legitimacy of the 
activity, because the hazardous secondary materials are not 
substituting for the feedstock, but are instead being processed in a 
different manner than the conventional coking feedstocks.
    As described earlier, there are two aspects of the coking operation 
for the Agency to consider: (1) conventional coking--which entails the 
application of high temperatures to the heavy oil-bearing feedstock in 
the coke drum in order to break the complex hydrocarbon chains into 
lighter chains that are recovered for further refining, also resulting 
in the production of coke product, and (2) the quenching process--
which, for the purposes of the Agency's evaluation in today's 
rulemaking, entails the insertion of oil-bearing hazardous secondary 
materials along with, or just prior to, water used to quench the coke 
product before removal from the coke drum.
    Because the hazardous secondary materials are not processed along 
with the normal feedstocks to the coker, but rather are introduced into 
the coke product during the quenching process, the assessment of 
``legitimacy'' becomes somewhat more difficult since there is no 
analogous raw material. (The Agency notes that this is typically the 
situation when determining the applicability of RCRA regulations to 
secondary materials used in connection with innovative technologies or 
practices.) The hazardous secondary materials are typically mixed with 
water to form a slurry that is injected into the coke at the beginning 
of the quench cycle (in some cases, the secondary materials are not 
slurried and are inserted ahead of the quench water). The hazardous 
secondary materials are unable to be used in conventional coking 
because of their high water content; however, the water content is not 
detrimental during the quenching process. Thus, in determining the 
legitimacy of this activity, the task at hand is not a straightforward 
comparison with analogous nonwaste feedstocks, but rather an evaluation 
of the processing that occurs when these hazardous secondary materials 
are used in the quenching process, to determine whether this activity 
may be characterized as a ``normal'' production activity or whether it 
is better characterized as hazardous waste recycling, or even simply 
the disposal of hazardous wastes (i.e., sham recycling).
    Indeed, some commenters opposed to the use of hazardous secondary 
materials in the petroleum coker raised the concern that the use of 
listed hazardous wastes in the quenching process is simply a means of 
disposing of RCRA hazardous wastes in a low-value product, much of 
which is exported overseas, and that if these materials truly had value 
to the coking process, they would be used as feedstock in the 
conventional coking process. Since it is obvious that these secondary 
materials would otherwise be hazardous wastes that would be treated and 
disposed of if not used in the quenching process, it would seem to be a 
simple matter, as some commenters have suggested, to ascribe a simple 
waste disposal motive to this activity and nothing more.4 
However, the Agency is compelled to go further and determine whether 
the oil-bearing secondary materials actually contribute to the product 
and/or process, or otherwise determine whether there is a production-
related value to this activity.
---------------------------------------------------------------------------

    \4\ Indeed, internal industry literature, as well as public 
statements made by industry representatives, relevant to the use of 
hazardous secondary materials in the quenching operation would lead 
one to believe that the principal purpose of this activity is to 
dispose of hazardous waste sludges (see the January 9, 1998 letter 
from Richard Fortuna to Mike Shapiro); however, the Agency does not, 
as a rule, take such statements as determinative and evaluates the 
activity independent of how the process may have been characterized 
in other contexts. The Agency would do the same in situations where 
all such industry statements would indicate that a particular 
process is legitimate production, i.e., evaluate the merits of the 
activity independent of statements from interested parties.
---------------------------------------------------------------------------

    The petroleum industry, on the other hand, believes that such an 
evaluation is unnecessary. Industry representatives argue that oil-
bearing secondary materials used in the quenching process for 
legitimate recovery of hydrocarbon as either a light oil fraction or by 
incorporation in petroleum coke can never be a solid waste, i.e., that 
these materials must be excluded from being RCRA solid wastes as a 
matter of law.5 Their argument is based on the initial case 
considering the scope of the statutory term ``solid waste,'' namely the 
first AMC I decision. In that decision, the Court held that ``materials 
that are recycled and reused in an ongoing manufacturing or industrial 
process''

[[Page 42123]]

were not yet discarded and hence not ``solid wastes.'' (see 824 F.2d at 
1186).
---------------------------------------------------------------------------

    \5\ See January 23, 1998 letter from Paul Bailey to Michael 
Shapiro.
---------------------------------------------------------------------------

    EPA disagrees that an exclusion is compelled (even assuming 
legitimate recycling is occurring). First, there is direct case 
authority that secondary materials which originate from wastewater 
treatment systems can be considered to be ``discarded'' (see AMC II, 
907 F.2d at 1186 (``Nothing in AMC I prevents the agency from treating 
as `discarded' the wastes at issue in this case, which are managed in 
land disposal units that are part of wastewater treatment systems, 
which have therefore become `part of the waste disposal problem,' and 
which are not part of ongoing industrial processes'' (emphasis 
original)). Industry indicates that, primarily, the oil-bearing 
hazardous secondary materials utilized in the quenching process are 
wastewater treatment sludges (chiefly K048, F037, and F038), which are 
thus directly analogous to the sludges at issue in the AMC II decision, 
and thus could be considered to be discarded.
    These sludges likewise could be considered to be solid wastes 
pursuant to RCRA section 3004(q)(2)(A) which indicates that certain 
provisions otherwise applicable to hazardous waste-derived fuels do not 
apply to petroleum coke produced from ``petroleum refinery wastes 
containing oil which are converted into petroleum coke at the same 
facility at which such wastes were generated.'' The plain language of 
the provision can be read to cover the activity at issue here, and thus 
indicate that wastewater treatment sludges and other hazardous 
secondary materials going to quench coking could be classified as solid 
wastes. 6
---------------------------------------------------------------------------

    \6\ The AMC I court gave this provision a restrictive reading, 
stating (somewhat circularly) that is applied only to material that 
had already become a hazardous waste (824 F. 2d at 1188.) However, 
given the holding of AMC II that wastewater treatment residuals can 
be classified as solid wastes and that wastewater treatment 
operations break any chain of what must be regarded as a continuous 
industrial process, the wastewater treatment sludges destined for 
the quenching process could be classified as being hazardous wastes.
---------------------------------------------------------------------------

    More basically, EPA does not regard the use of oil-bearing 
wastewater treatment sludges in the quenching process to be the type of 
operation which must necessarily be classified as part of an ongoing 
manufacturing process. The parts of the petroleum refining process 
outside the Agency's RCRA jurisdiction involve the sequential 
distillation of crude oil into various fractions such as gasoline, fuel 
oil, asphalt, and conventional coking. (see 824 F.2d at 1181). However, 
the quenching process need not be viewed as one more ongoing step in 
this process. Not only is there the temporal interdiction of the 
generation of wastewater and subsequent management of the wastewater 
and sludges in the refinery's wastewater treatment system, but the 
quenching process differs in material ways from the standard refining 
operations. As discussed above, the materials utilized have less oil, 
higher percentages of unusable materials, and the process generates 
less recovered oil than any other unit operation in the conventional 
refining process. The Agency thus does not accept the argument that 
exclusion of hazardous secondary materials used in the quenching 
process is legally compelled.
    This is not to say that the Agency lacks the discretion to make 
such a determination. The term ``discarded'' is ambiguous, and within 
the Agency's authority to interpret consistent with the general goals 
and policies of the statute. (See AMC II, 907 F. 2d at 1186; American 
Petroleum Inst v. EPA, 906 F. 2d 726, 741 (D.C. Cir. 1990)). Among 
these goals, of course, is encouraging environmentally sound recycling 
(see RCRA section 1003(a)(6)). Moreover, assessing what can permissibly 
be classified as continuous industrial processes, and which types of 
material recovery operations are ``not part of the waste disposal 
problem'' (AMC II, 907 F.2d at 1186), are the types of technical and 
policy questions particularly committed to EPA's expert discretion. It 
is that discretion which the Agency is exercising in determining in 
this rule that a conditional exclusion is appropriate for certain 
hazardous oil-bearing secondary materials used in the coke quenching 
process.
    In describing the use of oil-bearing secondary materials in the 
quenching process, industry claims that, similar to the process of 
coking resids feedstock, the oil contained in the secondary materials 
is either volatilized and condensed for further refining into high-
value fuels, or is incorporated into the coke product. This activity 
may be characterized as the efficient use of existing heat energy in 
the hot coke to recover the oil contained in the sludges, oil which 
would otherwise not be recovered (the temperature of the coke is 
approximately 800-900 degrees F before it is quenched). The oil that is 
not volatilized gets incorporated into the coke product, adding to the 
coke's energy value. The quenching process is operated such that the 
slurry is discontinued once the coke reaches the temperature of 
approximately 600 degrees F because, at this temperature, the oil is 
less likely to volatilize and is primarily incorporated into the coke. 
(The coke product then continues to be quenched with water.) While the 
oil adds energy value, too much oil causes the coke product to actually 
lose economic value. Not only does too much oil make the coke difficult 
to handle, it also increases the Volatile Combustible Material (VCM) 
level, one of the product specifications for petroleum coke. If the VCM 
is too high, the marketability of the coke decreases. 7
---------------------------------------------------------------------------

    \7\ See the September 3, 1997, letter from Kyle Isakower to 
William Brandes and the January 23, 1998, letter from Paul Bailey to 
Michael Shapiro.
---------------------------------------------------------------------------

    The Agency solicited further information from industry to 
demonstrate the recovery efficiency of the oil contained in the 
hazardous secondary materials used in the quenching process. EPA 
believes that a comparison of the recovery efficiency of the quenching 
process to the recovery efficiency of the conventional coking process 
(of the resids) would provide some indication of how ``production-
related'' the use of the hazardous secondary materials in the quenching 
process is (i.e., the more similar the quenching process is to the 
conventional coking process in the recovery of hydrocarbon values, the 
more it may be considered analogous to, or a component of, the coking 
process). The data supplied indicate that the recovery efficiency of 
oil contained in the secondary materials during the quenching process 
is comparable to the recovery efficiency from the feedstock side of the 
coking operation. 8 Thus, although the oil content in the 
hazardous secondary materials is markedly less, at the very least, 
there is demonstrated hydrocarbon recovery from the secondary materials 
used in the quenching process, which is consistent with the overall 
production intent of petroleum refining.
---------------------------------------------------------------------------

    \8\ See January 23, 1998, letter from Paul Bailey to Michael 
Shapiro.
---------------------------------------------------------------------------

    The Agency notes that one major point of contention between those 
commenters opposed to the exclusion and those supporting the exclusion 
is whether there is actual evidence that oil (or hydrocarbon value) is 
recovered during the quenching process. As stated previously, the oil 
content of the oil-bearing hazardous secondary materials typically used 
in the quenching process varies considerably (8 to 40 percent), 
although the typical secondary materials have an oil content around 10 
percent. 9 In determining the oil recovery efficiency of the 
quenching process (i.e., a quantification of how much of the oil 
contained in the secondary materials is

[[Page 42124]]

actually volatilized and recovered for further refining versus how much 
oil is simply incorporated into the coke product), EPA encountered 
difficulty in getting any actual data. The data the Agency primarily 
relied on were derived from surrogate tests (i.e., tests designed to 
simulate the conditions the secondary materials encounter during the 
quenching process) performed on the secondary materials typically used 
in the quenching process. 10 This is because coking 
operations (particularly the capture and condensing of the light-end 
hydrocarbons) do not avail themselves to the type of quantifiable 
measurements that the Agency prefers. Regarding the quenching process, 
this is even more the case. However, surrogate tests may actually be 
more representative of the oil recovered from secondary materials used 
in the quenching process than actual measurements taken during the 
quenching process. This is because any measurement of the amount of oil 
recovered during the quenching process would also likely include the 
light ends that remain entrained within the coke product from the 
conventional coking operation (i.e., light-ends derived from the resids 
feedstock) which are typically recovered during the quenching process 
in a manner analogous to steam stripping.
---------------------------------------------------------------------------

    \9\ See the September 3, 1997, letter from Kyle Isakower to Max 
Diaz and the January 9, 1998, letter from Richard Fortuna to Michael 
Shapiro.
    \10\ See January 23, 1998, letter from Paul Bailey to Michael 
Shapiro.
---------------------------------------------------------------------------

    One of the critical factors in estimating the oil recovery 
efficiency of the quenching process is the specific gravity of the oil 
contained in the hazardous secondary materials. The lighter the oil 
fractions, the more oil will volatilize during the quenching process. 
Here, too, there was disagreement among commenters over how the oil 
contained in the secondary materials should be characterized. One 
commenter stated that since crude oils have grown steadily heavier 
(i.e., contain a larger percentage of higher molecular weight, higher 
boiling point hydrocarbons) over time, a trend that is only expected to 
continue, the oil contained in the secondary materials, especially the 
wastewater treatment sludges, would be disproportionately heavy and 
thus would be less and less likely to volatilize during the quenching 
process. This was supported by data (gathered from listed hazardous 
wastes sent to RCRA-permitted facilities) demonstrating the heavy-to-
light ratio for oil contained in the wastes. 11 In response, 
the petroleum industry stated that the oil contained in the secondary 
materials (particularly wastewater treatment sludges) comes from oil 
that has been through some refining, and thus the trend towards heavier 
crude oils will not have a corresponding effect on the oil contained in 
the secondary materials. Also, industry claims that the actual data 
used to support the assertion that the oil contained in the secondary 
materials is predominantly heavy is not representative of the secondary 
materials used in the quenching process because, prior to sending such 
materials to a permitted facility for proper treatment and disposal, a 
refinery will typically use other processes (e.g., centrifuging) to 
aggressively extract as much oil (and water to reduce the volume of 
material sent for treatment and disposal) as possible from the 
materials, more so than would be the case if these materials are to be 
used in the quenching process. The oil recovered by these more 
aggressive recovery processes would tend to be the lighter oils, 
leaving a disproportionate amount of heavy oil in the materials 
analyzed. 12
---------------------------------------------------------------------------

    \11\ See the January 9, 1998, letter from Richard Fortuna to 
Michael Shapiro.
    \12\ See the February 2, 1998, letter from John Medley to Max 
Diaz.
---------------------------------------------------------------------------

    Based on a considered evaluation of these conflicting comments, and 
using engineering and technical judgement in lieu of data actually 
demonstrating the recovery of hydrocarbon values from the secondary 
materials used in the quenching process, the Agency believes that oil 
(i.e., hydrocarbon value) is recovered during the quenching process and 
that the efficiency of this recovery is comparable to the recovery of 
light-ends during the conventional coking process. (The Agency also 
notes that in the worst case scenario provided by one commenter opposed 
to the exclusion, which assumed 80 percent of the oil in the secondary 
material was too heavy to significantly volatilize at the temperatures 
encountered during the quenching process, there was recovery of 
hydrocarbon, even from the heavy oil fraction.13)
Effect of Using Hazardous Secondary Materials in the Quenching Process 
on the Coke Product
---------------------------------------------------------------------------

    \13\ See the January 9, 1998, letter from Richard Fortuna to 
Mike Shapiro.
---------------------------------------------------------------------------

    A further consideration, in spite of the hydrocarbon recovery and 
contribution of energy value to the coke product, is whether the use of 
the hazardous secondary materials in the quenching process actually 
provides some beneficial contribution to the coke, or whether it may 
degrade the coke product. Commenters opposed to allowing the use of 
hazardous secondary materials in the quenching process raised two main 
concerns regarding the effect on the coke product. First, these 
commenters claim that the use of hazardous secondary materials in the 
quenching process contributes nothing beneficial to the coke product. 
These commenters dismiss the notion that the oil contained in the 
secondary materials used in the quenching process contributes energy 
value by stating that any energy value that may be gained is more than 
negated by the additional ash content that is also introduced to the 
coke product (thus, there is no net benefit to the product and instead 
a net degradation of the product).14 Furthermore, as at 
least one commenter noted, the ability for the coke produced using the 
hazardous secondary materials in the quenching process to continue to 
meet product specifications could simply be an indication that the 
specifications for this low-value fuel product provide a great deal of 
flexibility, rather than demonstrating that the product is not 
adversely affected. Thus, the product specifications themselves would 
allow for a certain amount of non-contributing hazardous secondary 
materials to be added to the coke product.15
---------------------------------------------------------------------------

    \14\ See the January 9, 1998, letter from Richard Fortuna to 
Mike Shapiro.
    \15\ See the January 9, 1998, letter from Richard Fortuna to 
Mike Shapiro.
---------------------------------------------------------------------------

    The second concern raised regarding the effect of the secondary 
materials on the coke product is that the coke product demonstrates no 
significant change in concentration of hazardous constituents due to 
the simple dilution that occurs when a relatively small amount of 
hazardous secondary material is mixed with a much larger volume of coke 
product (approximately 100 barrels, or about 20 tons of hazardous 
secondary materials are used in the quenching of 700-800 tons of coke 
product). Simply stated, the lead and chromium in the secondary 
materials are being diluted by combination with the much larger volume 
of coke product containing low levels of lead and chromium. Since these 
metals are not volatilized during the quenching process, they must 
remain in the coke product. Commenters point to the insertion of lead 
and chromium (which serve no purpose in the coke product) as evidence 
that the use of hazardous secondary materials in the quenching process 
is simply disposal of hazardous constituents. Such disposition of 
unwanted and unneeded hazardous constituents, often termed ``toxics 
along for the ride,'' is a prime indicia that sham recycling can be 
occurring (depending largely on the extent of contamination, as well as 
other case-

[[Page 42125]]

specific facts) (see U.S. v. Marine Shale Processors, 81 F.3d 1361, 
1366 (5th Cir. 1996)).
    In evaluating the first concern, i.e., whether the use of oil-
bearing secondary materials in the quenching process provides a 
beneficial contribution to the coke product or process, the Agency 
notes that the main purpose of the petroleum coking unit is to recover 
hydrocarbons from the oil contained in the feedstocks for further 
refining. Similarly, the main purpose of using the secondary materials 
in the quenching process is the energy-efficient recovery of 
hydrocarbon from the residual oil in the oil-bearing secondary 
materials. Concerning the issue of net contribution to the coke product 
(i.e., added energy value versus added ash content), the petroleum 
industry maintains that the additional ash content is insignificant and 
points to the amount of coke product produced per cycle (ranging from 
about 400 to 800 tons) that would be endangered if the ash content (as 
well as the VCM level) contributed during the quenching process was 
sufficient to lower the value or marketability of the coke 
product.16 In answer to the concern that the product 
specifications for petroleum coke are too flexible to use as an 
indication that the coke is unaffected by the hazardous secondary 
materials, the Agency notes that coke product produced using hazardous 
secondary materials in the quenching process is basically similar to 
coke produced without using secondary materials in the quenching 
process. Further, EPA notes that the quenching process can and does 
produce anode-grade coke, the most high-valued coke with the most 
stringent product coke specifications.17
---------------------------------------------------------------------------

    \16\ See the September 3, 1997, letter from Kyle Isakower to 
William Brandes and the January 23, 1998, letter from Paul Bailey to 
Michael Shapiro.
    \17\ See the September 3, 1997, letter from Kyle Isakower to 
William Brandes.
---------------------------------------------------------------------------

    In considering the second concern, i.e., whether the fact that the 
coke product produced using secondary materials in the quenching 
process continues to meet the product specifications (and, in fact, 
demonstrates little change in the levels of contaminants compared with 
coke produced without hazardous secondary materials) is simply a result 
of dilution, the Agency acknowledges that such dilution does occur. 
However, there are several other considerations. As stated earlier, the 
primary product of the petroleum coking process is the hydrocarbon 
fraction recovered for use as feedstock in the production of high-value 
fuel products, with the coke product being a co-product of the coking 
process. The Agency is convinced that such recovery occurs when oil-
bearing secondary materials are used in the quenching process. Given 
that the recovered hydrocarbon is the primary product of using the 
secondary materials in the quenching process, the simple fact that the 
coke product (i.e., the co-product) continues to meet the applicable 
product specifications and shows no appreciable increase in risk 
carries more weight in the Agency's evaluation. In other words, 
demonstrating hydrocarbon recovery is the key test in determining 
whether the hazardous secondary materials actually serve a useful role 
in the overall coking operation, rather than demonstrating a net 
contribution to the coke (as opposed to no degradation of the coke). 
Acknowledging that there is a potential for some degradation of the 
coke product, depending on the constituent make-up of the particular 
secondary materials used in the quenching process, the Agency believes 
that the product specifications, and the economic consequences if those 
specifications are not met, will serve to limit the use of the 
quenching process to secondary materials that will not cause the coke 
to exceed its specifications, and effectively limits the allowable 
insertion of metals and excess high boiling point hydrocarbons. 
However, in cases where there is sufficient degradation of the product 
(or co-product) such that it no longer meets product specifications or 
otherwise becomes unmarketable, the Agency would question the 
legitimacy of using the secondary materials in the quenching process. 
Similarly, if there were sharply decreased efficiency of hydrocarbon 
recovery stemming from the use of the hazardous secondary materials in 
the quenching process (recovery rates of, for example, less than 50 
percent of the oil contained in the secondary materials, rather than 
the minimum 70 percent efficiency EPA believes occurs), the Agency 
would question the legitimacy of the activity. (The Agency knows of no 
such cases at present.)
    Taken all together, the fact that (1) the recovery efficiency of 
hydrocarbons from oil contained in the secondary materials used in the 
quenching process is comparable to the recovery efficiency of the 
conventional coking process, (2) the use of oil-bearing hazardous 
secondary materials (including RCRA listed hazardous wastes) in the 
quenching process is consistent with the overall goal of the petroleum 
refining industry, namely to maximize the recovery of hydrocarbon 
values from the original crude oil feedstocks (and thus is akin to 
ongoing processing), (3) the oil cannot be recovered from these 
secondary materials by any other process customarily utilized in 
petroleum refining, and (4) the coke product continues to meet product 
specifications and indicates no increase in risk, the Agency concludes 
that the use of oil-bearing hazardous secondary materials generated by 
the refinery industry can legitimately be used in the coke quenching 
process, dependent upon whether there is both hydrocarbon recovery and 
no adverse effect on the coke product.

Regulatory Status of the Quenching Process

    Having determined that certain oil-bearing hazardous secondary 
materials can be legitimately used in the quenching process, the 
question then becomes whether this activity constitutes ongoing 
production and hence is excludable, or, rather that it is legitimate 
hazardous waste recycling--potentially subject to regulation as a form 
of hazardous waste treatment. There are several factors that could lead 
to either outcome. As stated earlier, there is recovery of hydrocarbon 
values from the oil-bearing secondary materials, short- and middle-
chain fractions that are condensed and sent to refining processes to 
produce high-value fuel products (consistent with the overall coking 
operation). In addition, there is some beneficial contribution to the 
coke product in the form of carbon and higher energy values (even 
though this may not be reflected by an actual increase in market 
value), and the Agency also notes that the coke product continues to 
meet the market-driven specifications for the product, even for high-
value anode grade coke. In addition, as with other sidestreams 
generated by one process and used as feedstocks to other production 
processes, this activity constitutes a link in the multi-step chain of 
processing steps designed to recover as much of the hydrocarbon value 
from the original crude oil feedstock as possible. Thus, there are 
aspects of this activity that lead one to conclude that the oil-bearing 
hazardous secondary materials used in the quenching process can be 
considered, for regulatory purposes, as part of an ongoing production 
process and hence classified as an activity not subject to RCRA 
jurisdiction.
    There are, however, several factors that were raised in comments to 
argue that using the hazardous secondary materials in the quenching 
process is a form of waste management, e.g.,

[[Page 42126]]

legitimate hazardous waste recycling. The oil-bearing secondary 
materials are not typical of normal feedstocks to any other refining 
process. Typical feedstock streams are very high in oil content (i.e., 
primarily oil), while these secondary materials contain a range of oil 
concentrations that is consistently much lower than typical feedstocks 
(thus resulting in a much smaller amount of oil being recovered, albeit 
at an efficiency comparable to conventional coking, as discussed 
above).
    There are numerous statements, both written and verbal, found 
within the industry's internal descriptions of the use of hazardous 
secondary materials in the quenching process, that depict this activity 
as an efficient means of disposing of RCRA hazardous 
wastes.18 There is also anecdotal evidence of a refinery 
with a coker charging another refinery without a coker to take such 
oil-bearing hazardous secondary materials which are then used in the 
quenching process, analogous to tipping fees or charges that a 
hazardous waste recycling facility would receive from a generator in 
return for a waste management activity. These issues are some of the 
reasons EPA felt it was not compelled by statute to exclude these 
wastes as ongoing manufacturing, and that this is a decision for EPA's 
discretion.
---------------------------------------------------------------------------

    \18\ See the January 9, 1998, letter from Richard Fortuna to 
Mike Shapiro.
---------------------------------------------------------------------------

    In considering both viewpoints, the Agency has decided that use of 
hazardous secondary materials in the quenching process warrants an 
exclusion from the definition of solid waste (always assuming that the 
particular practice is legitimate recycling). In the Agency's view, the 
primary purpose of this activity is the recovery of the remaining 
hydrocarbon values in the oil-bearing secondary materials (with the 
addition of carbon and energy value to the co-product coke), utilizing 
the existing heat energy contained in the coke product after the 
conventional coking process. The assertion, by commenters opposed to 
this activity that it is questionable that the component in the 
secondary material that fulfills its primary purpose (i.e., oil) could 
also be a limitation on the use of the secondary material (i.e., that 
too much oil would degrade the coke product itself) is not compelling. 
It is not uncommon for industrial processes to have specifications on a 
feedstock material that require a minimum of a certain component while 
at the same time requiring that a maximum level for the same component 
not be exceeded because it would degrade the quality of the product. 
EPA also believes that the lead and chromium in the secondary materials 
should decline with time. This is due to overall reductions in the use 
of these metals throughout the refinery (e.g., leaded gasoline is no 
longer produced on a wide scale and chromium-based water treatment 
chemicals are no longer used in industrial cooling towers, as a result 
of Clean Air Act requirements; see 40 CFR Part 63, Subpart Q). Thus, 
with the exception of lead and chromium (which are expected to decrease 
due to process changes), the hazardous metals found in the hazardous 
secondary materials can be traced back to the metals found in the 
original crude oil feedstock and so do not represent contaminants 
introduced through means other than the continued processing of the 
initial raw material feedstocks. EPA's traditional concern regarding 
unnecessary hazardous constituents being processed and ending up in a 
product is mitigated in this case because the Agency views this 
activity more as the continual processing of a raw material that 
contains hazardous constituents, with concentrations of these 
constituents found in the feedstock streams to various refining 
processes varying dependent on the point in the overall production 
process. In the context of a multi-step production process, there is 
much less of an element of discard of the hazardous constituents 
inherent in the original raw material than there would be had these 
secondary materials been generated by another industry or had the 
hazardous constituents not been inherent to the original raw material.
    EPA also has no evidence that the quenching process could be viewed 
as part of the waste management problem, part of the jurisdictional 
tests articulated in AMC I and II. As discussed earlier, there is no 
significant evidence of degradation of coke product quality, and 
indeed, coke produced with and without using secondary materials in the 
quenching process are largely indistinguishable from the standpoint of 
concentrations of hazardous constituents.19 Finally, again, 
EPA believes that the recovery of hydrocarbon from the oil-bearing 
secondary materials in the quenching process is consistent with the 
overall petroleum refining process the coking operation in particular, 
i.e., the recovery of hydrocarbons for the production of high-value 
fuel products. This goal, in turn, is consistent with the RCRA 
objective to encourage safe types of recycling (see RCRA section 
1003(a)(6)). Therefore, the Agency is providing a conditional exclusion 
for oil-bearing hazardous secondary materials that are inserted into 
the coker, based on the assumption that, whether inserted along with 
normal feedstock (i.e., resids) or used in the quenching process, 
hydrocarbons are recovered for further refining and there is no 
degradation of the coke product.
---------------------------------------------------------------------------

    \19\ See the January 23, 1998, letter from Paul Bailey to 
Michael Shapiro.
---------------------------------------------------------------------------

Conditions for the Exclusion

    As stated at proposal (60 FR at 57754-57755), the exclusion 
applicable to oil-bearing hazardous secondary materials destined for 
insertion into the petroleum refinery, including the coker (and the 
quenching process), is conditioned on there being no land placement and 
no speculative accumulation, ensuring that these oil-bearing hazardous 
secondary materials do not become part of the waste disposal problem. 
EPA reiterates its belief, presented in the proposal, that the 
management of these secondary materials prior to insertion into the 
refinery will not pose a risk to human health and the environment, and 
that the American National Standard Institute (ANSI) standards for the 
design, construction, operation, maintenance, and inspection of 
petroleum terminal and tank facilities are sufficient to ensure that 
such materials will be managed in an environmentally protective manner. 
The Agency also notes that the exclusion being promulgated today is 
only for those oil-bearing hazardous secondary materials that are 
actually used in a refining process, including the quenching process of 
a petroleum coker. Hazardous secondary materials that are released and 
not immediately recovered and used in a refining process would not be 
excluded, and thus would be subject to Subtitle C regulation as 
hazardous wastes that have been disposed.20
---------------------------------------------------------------------------

    \20\ The Agency notes that today's rulemaking is not intended to 
affect the applicability of existing regulatory exclusions in 
Sec. 261.2(c)(2) and (3) regarding the reclamation of off-
specification or spilled commercial chemical products listed in 
Sec. 261.33, or that otherwise exhibit a hazardous characteristic 
(50 FR 14219; April 11, 1985).
---------------------------------------------------------------------------

    The Agency is also requiring that the materials excluded under this 
provision of today's rule be returned directly to a refinery for 
insertion. While this is not an issue if materials are recycled onsite, 
EPA has concerns (as did some commenters) about situations where these 
materials are generated at one refinery for insertion into another, but 
are not directly sent and instead are sent to an intermediate non-
refinery facility for processing. EPA does not think it

[[Page 42127]]

unreasonable to assume that these materials should either be located at 
the generating refinery, at the receiving refinery, or are otherwise in 
transit between the two; this is consistent with the underlying 
argument that this is ongoing production within the petroleum refining 
sector.
    The Agency is maintaining the condition that only those oil-bearing 
secondary materials that result in a coke product that does not exhibit 
a characteristic of hazardous waste be subject to the exclusion. This 
condition mirrors the statutory provision stating that petroleum coke 
produced from petroleum industry hazardous wastes is not subject to 
Subtitle C regulation provided the coke does not exhibit a 
characteristic of hazardous waste (see RCRA section 3004(q)(2)(A)). 
This condition (coupled with the industry's own product specifications) 
will serve to ensure that the coke product does not degrade such that 
the secondary materials used in producing the coke will become a part 
of the waste disposal problem. As a result of this condition and the 
fact that this exclusion is limited to refinery wastes, today's 
exclusion in Sec. 261.4(a)(12) supersedes the existing exemption in 
Sec. 261.6(a)(3)(v); therefore, the regulations are being amended to 
remove Sec. 261.6(a)(3)(v).
    The Agency considered, as suggested in several comments, setting a 
minimum oil content to define the scope of ``oil-bearing secondary 
materials'' that are excluded when used in the quenching process, or to 
require a demonstration of hydrocarbons actually being recovered from 
the excluded secondary materials that is comparable to oil recovery in 
the conventional coking process. The Agency rejected limiting the 
exclusion based on a set minimum oil content or a recovery efficiency 
requirement for several reasons. As discussed above, the quenching 
process represents the final, and last possible process in which to 
recover hydrocarbon from the original crude oil feedstock. The refinery 
processes and operating procedures are designed to separate and process 
into products as much hydrocarbon as possible from the crude oil 
feedstock; in other words, to prevent as much oil from making its way 
into these secondary materials as possible. The oil that does make its 
way into these secondary materials is generally considered unavoidable 
and inevitable, or, in some cases, too much oil in these secondary 
materials is evidence of a problem with some aspect of the overall 
refining process (which helps to explain the wide range of oil contents 
in these materials). Thus, it would be counter to the overall 
efficiency of the petroleum refining process to require a minimum oil 
content in the secondary materials. Conversely, the Agency believes it 
is fundamental to this exclusion that there actually be oil recovered 
for further refining when these oil-bearing hazardous secondary 
materials are used in the quenching process. To the extent there is no 
recovery, or drastically inefficient recovery, the operation could be a 
type of sham recycling, as discussed earlier.
    Also, the Agency believes that, in this case, a minimum oil content 
condition would do little to ensure that only those secondary materials 
from which oil can actually be recovered would be excluded; in other 
words, the Agency does not believe that setting a minimum oil content 
would ensure that secondary materials are legitimately being used in 
the quenching process. Since most of the secondary materials in 
question result from wastewater treatment, a minimum oil content 
requirement would only serve to encourage a refinery to operate the 
refinery wastewater treatment process less efficiently to ensure that 
these secondary materials contain the minimum oil content and thus 
avail themselves of an exclusion.
    As for requiring a demonstration of oil recovery efficiency 
comparable to the conventional coking process, the Agency concluded 
that the normal operating practices and conditions (e.g., temperature) 
inherent to the quenching process will result in a comparable oil 
recovery efficiency. While there may be fluctuations in the actual 
volume of oil recovered (due to the fluctuations in the oil content of 
the secondary materials as well as the ratio of heavy-to-light oil in 
the secondary materials), the quenching process, when properly 
operated, is such that there will be oil recovered from oil-bearing 
hazardous secondary materials due to the high temperatures inherent in 
the process. Therefore, requiring an actual demonstration of recovery 
efficiency would be unnecessarily burdensome unless there is a question 
regarding a site-specific coke quenching process or the hazardous 
secondary materials being used. Therefore, the exclusion for refinery-
generated, oil-bearing hazardous secondary materials being legitimately 
recycled into the petroleum refining process, including in the coke-
quenching process, is conditioned only on these materials being managed 
such that there is no land placement and no speculative accumulation, 
and that the coke product produced not exhibit a characteristic of 
hazardous waste.

Materials Subject to the Exclusion

    At proposal, the Agency proposed to exclude oil-bearing hazardous 
secondary materials that are generated within the broad petroleum 
industry (covering SIC codes 1311, 1321, 1381, 1382, 1389, 2911, 4612, 
4613, 4922, 4923, 4789, 5171, and 5172--which comprise petroleum 
refining, marketing, transportation, exploration, and production) and 
inserted in the petroleum refining process, including in the coker. As 
discussed earlier in today's preamble, the exclusion being promulgated 
today is limited to only those oil-bearing hazardous secondary 
materials that are generated within the petroleum refining sector (SIC 
code 2911). To conform with this limitation, EPA is retaining (with 
some clarification) the existing exclusion for recovered oil from the 
broader petroleum industry. (EPA is also excluding petrochemical 
recovered oil from certain petrochemical facilities, which is a related 
but different exclusion discussed elsewhere in today's rule.) In the 
context of oil-bearing hazardous secondary materials being used in the 
quenching process, limiting the exclusion to the petroleum refining 
sector is entirely consistent with the information evaluated in making 
this determination (i.e., data representing the materials currently 
used in the quenching process, namely F037, F038, and K048-K052). As 
discussed above, the exclusion for oil-bearing hazardous secondary 
materials used in the quenching process was not made on a strict 
jurisdictional basis. The types of secondary materials, their 
constituent components, and the fact that the coke product remains 
basically unchanged when such secondary materials are used were all 
factors in EPA's determination. The fact that the Agency only evaluated 
oil-bearing secondary materials that were generated by the refining 
sector in its determination is sufficient reason to limit the exclusion 
to refinery-generated secondary materials.
    However, a further reason relates to the concept that oil-bearing 
secondary materials that are generated by the refining process and 
continue to be processed in the coker (by use in the quenching process) 
is more akin to an ongoing production process than would be the case 
for secondary materials generated outside the refining sector of the 
petroleum industry. The Agency maintains that the quenching process is 
an ancillary activity that is somewhat removed from the overall 
production process; however, the fact that the secondary materials are 
generated and

[[Page 42128]]

used in another production process (i.e., the overall coking operation) 
within the same industry, imparts a closer association with the concept 
of an ongoing production process (see AMC I) than would be the case for 
secondary materials generated by a different industrial sector. The 
Agency has no information on which to base a finding that the use of 
oil-bearing hazardous secondary materials originating in a non-refinery 
sector of the petroleum industry in the coke quenching process would be 
anything other than the management of wastes (e.g., hazardous waste 
recycling) from that non-refinery sector.
    In one sense, the exclusion for recovered oil (as opposed to ``oil-
bearing secondary materials''), which spans the scope of the broad 
petroleum industry, reflects the Agency's assessment that only those 
hazardous secondary materials that are comparable to normal feedstocks 
(i.e., oil) used in typical production processes should be excluded 
from RCRA without attention to how they are processed. Oil-bearing 
secondary materials (as opposed to ``recovered oil'') originating from 
a non-refinery sector have the potential to be more waste-like (i.e., 
they are not clearly ``oil'' and also may contain types or quantities 
of toxic constituents that have not been evaluated, especially if their 
ultimate use is in the quenching process) and thus do not warrant an 
exclusion. Therefore, the Agency is today promulgating an exclusion for 
(1) secondary materials that are similar to normal refining feedstocks, 
even if generated by a non-refinery petroleum industry sector (i.e., 
recovered oil) and (2) secondary materials that are both generated by 
and used in any refinery production process, including the coking 
operation (i.e., refinery-generated oil-bearing hazardous secondary 
materials).
    The Agency notes, however, that non-refinery generated oil-bearing 
secondary materials that are used in the quenching process (i.e., 
hazardous wastes) may nevertheless be legitimately recycled by use in 
the quenching process, depending on there being oil recovered during 
the quenching process and no adverse impact on the coke product. The 
oil recovered during the coking operation (including both conventional 
coking and the quenching process) is excluded from the definition of 
solid waste under 40 CFR 261.4(a)(12). The coke product produced from 
such hazardous wastes, however, would be subject to hazardous waste 
fuel regulations. This does not represent a change from current 
requirements, because the current regulatory exemption for coke 
produced using hazardous waste (superseded by today's exclusion for 
refinery waste being recycled) does not apply to coke produced using 
anything but refinery-generated waste.

Status of Residuals from Processing or Recycling Excluded Oil-
Bearing Secondary Materials

    EPA received comments stating that the proposed rule did not 
clarify the status of residuals generated from the processing and 
recycling of excluded oil-bearing hazardous secondary 
materials.21 Specifically, certain oil-bearing hazardous 
secondary materials generated at petroleum refineries are listed 
hazardous wastes if they are discarded instead of recycled as described 
in today's rule. However, the Agency is aware that these materials may 
be processed in various ways prior to insertion into the petroleum 
refinery, depending upon the nature of the oil-bearing material and the 
intended point of insertion into the refinery. Some of these processing 
steps may result in residuals that are not suitable for insertion, 
again based upon the choices available to the refinery. If these 
residuals are to be discarded, they are clearly solid wastes and would 
not retain their original hazardous waste listing because of the 
exclusion. The hazardous waste characteristics may or may not capture 
these materials, and therefore they could be disposed of outside the 
Subtitle C system. The Agency then became concerned about situations 
where, for example, a listed waste was generated and only minimally 
processed to recover oil for insertion into the refining process, 
leaving behind a largely unchanged residual that was to be discarded 
but was no longer defined as listed waste. The Agency agreed that this 
was a potential problem with the exclusion, and a subsequent request 
for comment letter was sent to interested parties on October 1, 1997. 
EPA requested comment on whether the interested parties viewed this 
situation as a potential loophole, and what, if anything, might be done 
to remedy it. Responses to EPA's request were somewhat mixed. Some 
commenters did not believe the loophole was a realistic construction of 
the effect of the exclusion, while others agreed that it was indeed 
problematic and needed to be addressed. After reviewing the information 
submitted by commenters, the Agency has decided that it would be an 
undesirable outcome if listed wastes were only marginally processed, 
generating residuals that were not recycled and escaped regulation. 
Therefore, the Agency has slightly modified the existing hazardous 
waste listing description in 40 CFR 261.31 for the F037 waste, to 
include in the listing description any residuals generated from 
recycling or processing oil-bearing secondary materials that (1) would 
have otherwise met a listing description when originally generated, and 
(2) are disposed of or intended for disposal.
---------------------------------------------------------------------------

    \21\ Comment PRLP-0054, ARCO Products Company.
---------------------------------------------------------------------------

2. Recovered Oil From Associated Petrochemical Facilities
    It is logical that the Agency evaluate the integrated nature of 
petroleum refining and petrochemical manufacturing to further identify 
oil-bearing materials that can be permissibly classified as part of 
``ongoing manufacturing'' within the petroleum industry, and that are 
not part of the waste disposal problem. In proposing the exclusion for 
oil-bearing materials from petrochemical operations which are returned 
to refining, the Agency had two important considerations. The first 
consideration was to encourage the recovery of a valuable resource and 
reduce regulatory uncertainties in cases where oil from petrochemical 
facilities is returned to petroleum refineries, specifically in 
situations where the refineries generally provide the raw materials 
(refinery products) to the organic chemical manufacturing facilities. 
The second was to consider whether or not these hydrocarbon streams 
have accumulated toxic constituents through the various chemical 
manufacturing processes, constituents that have no value to the 
petroleum refinery, are different from the constituents typically 
encountered in a petroleum refinery, and may be inadequately managed 
through this activity. Given the large and complex nature of the 
organic chemical manufacturing industry, this was not a straightforward 
undertaking. Accordingly, the Agency proceeded cautiously, engaging in 
discussions with representatives from both the chemical manufacturing 
and petroleum refining industries.22 As discussed at 
proposal, the Agency agreed with industry arguments indicating that 
because significant volumes of materials composed almost exclusively of 
oil from petrochemical facilities are being directed to various 
petroleum refining processes, careful controls were in place

[[Page 42129]]

as a result of concerns about operational upsets and product quality. 
(See 60 FR at 57756). For example, representatives from the petroleum 
industry have stated that they have significant concerns about the 
presence of organic chlorides in their process units due to damage from 
corrosivity. In addition, comments submitted by the chemical 
manufacturing industry describe ``feedstock quality management 
programs,'' whereby the quality of petrochemical recovered oil is 
routinely evaluated and its contribution to refinery product 
performance determines its acceptability and value. One commenter, an 
organic chemical manufacturer, stated that due to the critical nature 
of refinery finished product specifications, all sources of 
hydrocarbons to a petroleum refinery are assessed to ensure their 
suitability. This ``suitability'' of petrochemical recovered oil is 
assessed either through process knowledge or periodic analyses of 
certain characteristics, including water and solids content, gum-
forming compounds, and metals. As the Agency has noted elsewhere in 
today's rule, the petroleum refining process can be described as a 
process of separating valuable product materials from the contaminants 
inherent in the original feedstock, crude oil. Based on comments 
submitted by the organic chemical manufacturing facilities that supply 
these hydrocarbon streams to refineries, refinery operators cannot 
simply assume that certain contaminants will be separated from 
hydrocarbon feedstocks (crude oil or petrochemical recovered oil) 
during the refining process without potentially causing equipment 
fouling, corrosion, or problems with product quality. Further, due to 
the integration between some refineries and organic chemical 
manufacturers, there is a shared stake in avoiding costly shutdowns, 
operational upsets, or other situations that might compromise the 
overall safety and profitability of the combined facilities. It is from 
this perspective that EPA began reviewing information indicating that 
recovered oil from organic chemical manufacturing facilities was 
acceptable to the refinery as a substitute for crude oil.
---------------------------------------------------------------------------

    \22\ April 7, 1995, and July 31, 1995, letters to Steven 
Silverman (EPA Office of General Counsel) and September 13, 1995 
letter to Becky Daiss, from Michael W. Steinberg (Morgan, Lewis & 
Bockius).
---------------------------------------------------------------------------

    The Agency acknowledged in the proposed rule that this potential 
exclusion was based on a ``very limited set of data'' (see 60 FR at 
57756). At proposal, EPA was interested largely in how petrochemical 
recovered oil compared to refinery recovered oil, in terms of the 
parameters that would indicate suitability of the material for refining 
(e.g., specific gravity; distillation temperature range; flash point; 
hydrocarbon type; and sulfur, ash, and total chlorine/halogen content). 
EPA also was interested in comparisons to the used oil specification, 
in part because EPA has used the used oil specification in a previous 
rulemaking as a surrogate for product fuel oil. Although EPA recognizes 
(and two commenters independently agreed) that there are shortcomings 
in using the used oil specification in the context of analyzing 
petrochemical recovered oil (largely because of the purposes for which 
the used oil specification was derived) the specifications for metals 
and halogens are a partial surrogate for crude oil content. The Agency 
also considered comparing the composition of the petrochemical 
recovered oil to ``comparable fuel specifications'' currently being 
developed as part of a separate Agency effort to define specifications 
which would indicate when a secondary material would pose no greater 
risk when burned than a fossil fuel, and therefore might be defined as 
products, not wastes (see proposed rule at 61 FR at 17460, April 19, 
1996). However, comparing the petrochemical recovered oil halogen data 
to the comparable fuel specification did not seem appropriate because 
the petrochemical recovered oil is not being burned as a fuel, but is 
instead being inserted into a complex series of fuel manufacturing 
processes (i.e., petroleum refining), where contaminants are removed 
and hydrocarbons are converted into various fuel products.
    In response to EPA's request in the proposed rule, data was 
received during the comment period on samples of various hydrocarbon 
streams from organic chemical manufacturing facilities (SIC code 2869) 
and non-organic chemical manufacturing units (representing SIC codes 
2821, 2822, 2865) located at these same facilities. EPA also received 
some data representing other non co-located, intercompany chemical 
manufacturing facilities. The organic chemical manufacturing data 
(representing SIC code 2869) indicate that in comparison to refinery 
recovered oil, the petrochemical stream was similar, and in some 
aspects, ``better'' than the refinery sample (i.e., the petrochemical 
recovered oil was a ``narrower cut'' requiring less refining, thus 
preferable to a refiner). When comparing the submitted data 
representing SIC code 2869, as well as a sample of refinery recovered 
oil, to the used oil specification, both samples were well within the 
specification (with the exception of flashpoint, which is not a concern 
here). Regarding total halogens, the highest concentration reported in 
a sample of petrochemical recovered oil was 3,400 ppm (parts per 
million ) total chlorine. Irrespective of where this number fell with 
regard to the used oil specification for total halogens (at 1000 ppm 
EPA presumes mixing of used oil with hazardous waste has occurred; 4000 
ppm is an upper limit for burning used oil without being subject to 
certain requirements; see 40 CFR 279.11), the Agency was concerned 
about the possible source(s) of the halogens in the petrochemical 
recovered oil. Information submitted along with this data indicates 
that chlorine could be introduced in small amounts to petrochemical 
recovered oil due to the use of chloride-based catalysts. Subsequent 
comments clarified that the use of seawater as a ``seal'' in the 
petrochemical facility's oil/water separation system was the source of 
the chloride in that particular sample. The commenter indicated that 
although the use of seawater as a seal or barrier in the separation 
tank results in some salt entering the recovered oil phase, because 
this particular hydrocarbon stream is sent to a co-located petroleum 
refinery to be managed along with crude oil, the chlorides are removed 
in the same process that removes chlorides typically found in crude oil 
(i.e., the desalter unit).23
---------------------------------------------------------------------------

    \23\ December 29, 1997, and January 22, 1998, letters to David 
Bussard (EPA Office of Solid Waste) from Ronald Shipley (Chemical 
Manufacturers Association).
---------------------------------------------------------------------------

    In summary, in the analytical data submitted in response to the 
proposed rule, certain patterns in the composition of petrochemical 
recovered oil were evident, including a similarity in composition to 
refinery recovered oil being used as feedstock by the refinery.

Limitation on Petrochemical Recovered Oil

    As mentioned earlier, part of the evaluation of whether or not 
these recovered oils from petrochemical facilities are part of an 
ongoing manufacturing process within the petroleum industry, and 
whether the operation can be viewed as part of the waste disposal 
problem, includes whether or not these materials contain toxic 
constituents not normally present in typical refinery feedstocks and 
intermediates. One concern that the Agency has is the possibility that 
certain hazardous wastes, particularly wastes containing halogens, may 
end up in the petrochemical recovered oils either through inadvertent 
or intentional mixing (i.e., ``adulteration'').

[[Page 42130]]

Specifically, there are many secondary materials that the EPA has 
explicitly listed as hazardous (e.g., K-wastes at 40 CFR Part 261, 
Subpart D, under ``Organic Chemical Industry''). Many of these wastes 
are highly-halogenated residuals, and EPA studied each of these waste 
streams at the time they were listed and determined that their 
management is easily capable of posing significant risks unless done 
properly (viz. with exceeding care, such as is specified in the 
Subtitle C regulatory standards). EPA believes that these listed wastes 
are clearly distinct from the petrochemical recovered oils discussed 
here, and based on the information EPA has received on the recovered 
oils sent to refineries, these listed wastes are not recycled in this 
manner. To ensure that this ``adulteration'' of the petrochemical 
recovered oils (by mixing listed hazardous wastes) would be prohibited 
under today's final rule, EPA is limiting the petrochemical recovered 
oil exclusion to those recovered oils that are hazardous only because 
they exhibit the characteristic of ignitability (as defined in 40 CFR 
261.21) and/or toxicity for benzene (40 CFR 261.24, waste code D018). 
EPA believes that petroleum refineries are able to handle hydrocarbons 
that are ignitable and contain benzene, given the types of materials 
that are routinely managed at these facilities; also, based on the 
information EPA has received on these materials, these are likely the 
only characteristics that would classify these petrochemical recovered 
oils as hazardous.

Co-Located and Common Ownership

    EPA proposed that the exclusion for petrochemical recovered oil 
apply only where the organic chemical manufacturing facility is 
``associated'' with the petroleum refinery, either by being physically 
co-located or under common ownership. As mentioned previously, this was 
partly due to the limited data the Agency had, but also because EPA 
believed that the degree of integration between a petrochemical 
facility and a petroleum refinery that occurs in co-located and/or co-
owned situations helped ensure more familiarity with each other's 
manufacturing processes, composition of products and intermediates, and 
administrative procedures. These attributes go beyond the strict 
commercial relationship that is more typical of transactions between 
buyers and sellers of various secondary materials, by-products, and 
intermediates. However, the Agency has not been able to develop a 
definition of ``common ownership'' that would be clear and workable for 
such purposes. As part of EPA's continuing efforts to redefine solid 
waste, defining common ownership (as a possible means of describing 
certain intracompany transfers) also has been explored and has proven 
very difficult. This is largely because of the many complex ways in 
which ``ownership'' can be defined from both a financial and a legal 
perspective. EPA believes that to attempt to do so here would not prove 
effective. However, EPA does believe that the concept of ``co-located'' 
is more or less understandable and reflects physical boundaries as well 
as a degree of integration that would help ensure more control by each 
facility over the transfer of materials throughout the combined 
facility. ``Co-located'' in today's rule means that the petroleum 
refinery and the organic chemical manufacturing facility are physically 
adjacent to one another, or otherwise share a common boundary. In 
situations where the facilities consider themselves co-located but they 
are not physically adjacent nor do they share a common boundary, the 
Agency is further clarifying co-located to include facilities that have 
a high degree of integration with one another, as evidenced by things 
such as shared wastewater treatment systems; shared manufacturing 
units; transfer of materials via dedicated piping; environmental 
permits that cover both facilities; facilities that share common 
emergency response equipment, procedures, and planning; etc. These 
examples can be typical of physically co-located facilities, and 
therefore can be used to clarify cases where for one reason or another 
an integrated petrochemical and petroleum refinery do not actually 
share a common boundary. Also, to better define the relationship and 
degree of integration between a petroleum refinery and the co-located 
petrochemical facility, the Agency is including in the definition of 
``associated organic chemical manufacturing facility'' in 
Sec. 261.4(a)(18) the condition that the petroleum refinery that is 
receiving recovered oil from a co-located petrochemical facility also 
provides the hydrocarbon feedstocks to the same co-located 
petrochemical facility.

Other SIC Codes

    In the proposed rule, EPA stated that it would consider broadening 
the proposed exclusion to include hydrocarbon streams from certain 
other chemical manufacturing facilities, including plastic materials 
and resins (SIC code 2821), synthetic rubber (SIC code 2822), and 
cyclic crude and intermediate producers (SIC code 2865), if sufficient 
analytical data were received to support such a broadening. Much of the 
data that the Agency received on recovered oil from these other SIC 
codes actually represented recovered oil from process units that are 
located at petrochemical facilities whose primary classification is 
under SIC code 2869. In other words, many of the organic chemical 
manufacturing facilities can be described as vertically integrated, 
where process units classified under several SIC codes operate in an 
integrated fashion. For example, an organic chemical manufacturing unit 
under SIC code 2869 may produce intermediates that are then fed to a 
unit classified under SIC code 2821. Both units may produce hydrocarbon 
side streams that represent unreacted feedstock or other hydrocarbon 
by-products (consisting almost entirely of oil), which are typically 
commingled and sent to a co-located petroleum refinery for refining 
along with crude oil. (Of the three co-located petrochemical facilities 
for which the Agency received data on recovered oil, only one of them 
was engaged in operations classified solely under SIC code 2869; the 
other two facilities had units or activities from the other SIC codes 
as well). The Agency reviewed analytical data on recovered oils from 
specific process units representing SIC codes 2821, 2822, and 2865, and 
found these to be comparable to refinery recovered oil.
    Because the recovered oil from process units classified under the 
SIC codes 2821, 2822, and 2865 is similar to refinery recovered oil 
(where these units are part of vertically-integrated organic chemical 
manufacturing facilities whose primary SIC code is 2869), the Agency is 
including these materials in the scope of today's exclusion. These 
materials are typically managed together and returned to the co-located 
petroleum refinery together. Commenters also pointed out that limiting 
the exclusion of recovered oil to the primary SIC code, at a complex 
where several SIC codes are represented (and where the hydrocarbons are 
similar and recycled back to the petroleum refinery together) may have 
a significant impact on facilities with multiple SIC codes. Commenters 
also argued that segregating recovered oil systems based on differing 
SIC codes could be prohibitively expensive and may result in a 
reduction in hydrocarbons returned to the refinery. The regulatory 
language in today's exclusion at Sec. 261.4(a)(18) for petrochemical 
recovered oil will limit the exclusion to recovered oil from

[[Page 42131]]

associated petrochemical facilities whose ``primary'' SIC code is 2869 
(organic chemical manufacturing), but may also include SIC codes 2821, 
2822, and 2865.

B. Modeling Approaches and Risk Assessment

    Commenters provided extensive comments on various aspects of the 
modeling approaches and risk assessment used in the listing 
determinations. Many comments on the determinations were raised 
repeatedly for various wastes. Therefore, EPA discusses the most 
important risk and modeling issues below, and more specific comments 
important for individual wastes are addressed in Section V.C on 
Residual-Specific Comments. For complete responses to comments on these 
and other issues, see the Response to Comment documents for comments on 
the proposed rule and the NODA in the docket to today's rule.
1. Sampling and Analysis of Refinery Wastes

Use of the TCLP for Oily Wastes

    EPA characterized the wastes through an extensive effort of waste 
analysis, including analysis for constituents that leach out of the 
waste using the TCLP. In the TCLP, the waste is filtered to separate 
any liquid phase present, and the solids are then mixed with an aqueous 
solution in order to estimate the levels of the waste constituents that 
dissolve and separate into the liquid phase. The Agency's use of the 
TCLP as input to groundwater modeling for landfill disposal was 
challenged by several commenters as either underestimating or 
overestimating the leaching of constituents from the petroleum wastes 
studied, due to the oil and/or the multiple phases present in the 
wastes. EPA has decided that the TCLP is appropriately used in this 
rule to characterize the amount of hazardous constituents potentially 
released from landfills through aqueous leaching. As discussed below, 
EPA found no need to change its risk assessment because of any failure 
of the TCLP due to potential problems that might arise from the 
presence of oil in some wastes.
    One commenter argued that the TCLP is very conservative because it 
assumes that the waste is disposed of in a municipal solid waste 
landfill, and disposal of potentially hazardous industrial wastes in a 
municipal landfill is not a likely mismanagement scenario today. The 
commenter also argued that the TCLP is a water phase model, not a 
multi-phase model (multi-phase meaning wastes with high oil content 
leading to release of nonaqueous as well as aqueous phases). The 
commenter claims that use of the TCLP to estimate risks from oil-
bearing residuals (e.g., CSO and crude oil storage tank sediment) would 
produce overestimates of potential risks.
    EPA does not agree that the TCLP overestimates leaching levels for 
these wastes. EPA did not assume in its quantitative risk assessment 
that oily liquids elute from the landfill to groundwater, because EPA's 
initial and subsequent analyses showed that oil in the wastes in 
question was unlikely to migrate from a landfill containing these 
wastes. Thus, EPA did not use the TCLP to predict movement of oily 
liquids. While the commenter is correct in stating that the TCLP 
procedure was designed, in part, to represent leaching from a municipal 
landfill, the industry reported significant volumes of residuals being 
disposed in precisely the type of landfill modeled by the TCLP. 
Specifically, EPA examined the data collected from the 3007 
Questionnaire and found that, in fact, petroleum refineries reported 
146 wastes that were sent to municipal landfills (see Additional 
Listing Support Analysis, 1998, in the docket for this rule).
    Other commenters felt that the TCLP may underestimate the 
leachability of constituents from the refinery wastes due to high oil 
content. These commenters pointed to an EPA report presented in past 
rulemakings (e.g., the listing of F037/F038 refinery wastes, November 
2, 1990, 55 FR 46376), which indicated that the TCLP may underestimate 
leachate concentrations because of difficulties in the TCLP procedure 
associated with filtering oily wastes, such that any constituents in 
the oily fraction in the waste are not properly evaluated. The 
commenters believed that EPA should use alternative procedures for oily 
waste, specifically the Oily Waste Extraction Procedure (OWEP) rather 
than the TCLP.
    EPA disagrees with these comments. First, the report cited by the 
commenters discusses difficulties in filtering multi-phasic oily wastes 
(Evaluation and Modification of Method 1311 for Determining the Release 
Potential of Difficult-to-Filter Wastes, April 1990). Multi-phasic 
wastes are wastes with readily separable oil, solid, and possibly 
aqueous portions. EPA's lab results show that the wastes under study in 
this rule did not exhibit the filtration difficulties EPA has found 
with other, more problematic, oily wastes. The wastes studied were not 
multiple phases, heterogeneous, or difficult to filter. While EPA 
measured levels of ``total oil and grease'' (TOG) that appeared high 
for some wastes (e.g., up to 25 percent for crude oil storage tank 
sediment), the Agency stresses that the TOG method measures all 
extractable organic material, some of which are not likely to migrate 
out of the waste, such as waxes, greases, and other large molecular 
weight substances. The TOG method does not measure, in any sense, 
``free'' oil (i.e., oil that might migrate from the waste as a separate 
phase). Furthermore, the EPA report cited by the commenter concluded 
that the TCLP method was adequate, even for some ``oily'' wastes, 
provided the wastes could be filtered. EPA did not encounter the types 
of problems described in previous listings during the present 
rulemaking.
    Second, the Agency does not believe that the use of the OWEP method 
is necessarily more appropriate for the wastes under consideration. The 
OWEP method was designed to measure the aqueous mobility of the metals 
(not organics) present in wastes, and uses a strong solvent to remove 
the organic phase prior to leaching with the aqueous leachate used in 
the TCLP. This may significantly alter the original sample matrix and 
affect the leaching results, and the Agency recognizes that this 
aggressive method may not be fully representative of possible leaching 
from a landfill. Despite these concerns, EPA performed additional 
analysis of archived samples using the OWEP to fully respond to the 
comment by examining any differences in metals mobility between the 
TCLP and the OWEP. The results of this analysis were presented in the 
NODA. Based on the results of this analysis, EPA found that metal 
leachate results were similar between the two tests. Therefore, EPA 
concluded that oil content (as measured by TOG) does not appear to 
impact the mobility of metals in the wastes under study.
    Commenters on the NODA OWEP analysis argued that the results showed 
some increase in the mobility of several metals in the wastes, and 
argued leachable levels of arsenic, chromium, and lead are higher in 
some of the OWEP samples. However, the same commenters also questioned 
the validity of the OWEP reanalysis because three years had elapsed 
between the TCLP and OWEP analyses and pointed out that the reanalysis 
was not useful since the detection levels were higher for the TCLP 
analysis.
    EPA disagrees that any measurable differences, of which there were 
few, in the OWEP/TCLP results are dramatic or meaningful. Overall, the 
OWEP results are consistent with the original TCLP

[[Page 42132]]

data; only 14 out of 189 OWEP values were greater than the original 
TCLP concentrations. Moreover, 8 of the 14 higher OWEP values were 
associated with residuals that contained less than one percent oil and 
grease, thus indicating oil and grease content is not a significant 
factor. In fact, the variability within each waste category is greater 
than the variability between OWEP and TCLP results. Thus, any 
differences are more likely due to sample composition variability 
rather than the leaching technique. Furthermore, if oil content were 
truly interfering with the TCLP analysis, one would expect the wastes 
with higher oil content to show correspondingly greater leaching with 
the OWEP, but there is no such trend in the data (see NODA Response to 
Comment Document, 1998, Section I.C.1, for more detailed discussion of 
the OWEP data). While there are limitations in the OWEP data, the lack 
of any significant differences in the data sets that can be compared 
indicates that the use of the TCLP did not underestimate the leaching 
of the metals of concern.
    In response to the commenters' concerns over the use of the TCLP 
for measuring the mobility of organics in these refinery wastes, EPA 
examined the analytical data for the wastes under study to see if oil 
content (as measured by TOG) significantly affected the leachability of 
a key organic constituent (benzene) and presented the results in the 
NODA. For the 27 samples for which the leaching efficiency of benzene 
could be calculated, the average efficiency was 53 percent, i.e., 53 
percent of the total mass of benzene contained in the residual was 
extracted into the aqueous phase. This efficiency is governed by the 
solubility of benzene in water, as well as benzene's affinity for the 
specific sample matrix. In any case, while the leaching efficiency 
varied somewhat from sample to sample, the leaching rate was fairly 
consistent regardless of whether the waste contained higher or lower 
total oil; the average leaching efficiency for the six of the 27 
samples which had TOG above 1 percent (samples of crude oil tank and 
CSO tank sediment) was also 53 percent.
    Comments on the NODA suggested using the average leaching 
efficiency (53 percent) for modeling the key constituent benzene for 
all waste samples analyzed by EPA, regardless of the actual TCLP 
results for each waste. EPA disagrees with the suggestion to use the 
simple average TCLP leaching efficiency for all wastes studied, because 
this would ignore important waste-specific information. This approach 
would overestimate benzene levels for some waste and underestimate 
levels for others. Leaching results are dependent on the specific 
matrix, and EPA believes that the actual TCLP result is a better 
indicator of the potential mobility rather than an average for all 
wastes studied. The most important point to draw from EPA's evaluation 
of leaching efficiency for benzene is that these results indicate the 
TCLP mobility of benzene is not greatly affected by the oil content in 
these particular wastes.
    Comments on the data presented in the NODA also argued that EPA 
should evaluate TCLP leaching efficiency for constituents other than 
benzene, in particular for polycyclic aromatic hydrocarbons (PAHs). The 
commenters were concerned the oil content and free oil present in some 
wastes (CSO and crude oil storage tank sediment) would facilitate 
leaching of PAHs.
    EPA disagrees that these constituents, including benzene, will be 
more mobile due to free oil in the wastes under study, because the 
existing data show ``free'' oil is not present. EPA evaluated the 
leaching potential of benzene because this compound was found in 
various wastes and was a key constituent in the risk analyses due to 
its high toxicity and relative mobility. However, to respond to the 
comment, the Agency further evaluated the leaching potential of four 
additional constituents (xylenes, naphthalene, methyl phenol, and 
phenanthrene). These results indicate that there is no significant 
discernable trend with respect to lower leaching values associated with 
higher oil and grease content (see data presented in Tables 5 through 8 
in the NODA Response to Comment Document, 1998, in the docket for 
today's notice). The constituents generally leached in similar 
proportions for all residual types. It is not possible to calculate 
extraction efficiencies for most PAHs because these constituents were 
generally not detected in the TCLP extract due to their very low 
solubility in water. In any case, EPA notes that the two wastes with 
the higher measured TOG and PAH levels (CSO and crude oil storage tank 
sediments) are being listed as hazardous waste, thus largely addressing 
this concern.

Co-Solvency Effects

    Some commenters felt that the TCLP is inappropriate because it 
measures only the movement of contaminants that are dissolved in the 
liquid TCLP phase into the groundwater, and thus fails to consider the 
``co-solvency'' effects of oil and other compounds in the landfill. 
Such effects, they argue, would facilitate release and transport of 
constituents beyond that predicted by the TCLP, because of organic 
phases separating from wastes. The commenters offered no way to account 
for this in the modeling, but indicated this would increase risks.
    While the commenters' concerns are theoretically possible, EPA has 
no evidence that the co-solvency effect is significant in this case. To 
respond to the potential for co-solvency effects due to disposal of 
oily waste in landfills, EPA examined the only available data that 
provides any detailed characterization of potentially co-disposed 
wastes-data from the 3007 Questionnaire for the refinery wastes under 
study. Thus, EPA examined the TOG data available from the 3007 
Questionnaire for the refinery wastes that were reported to go to 
landfills. As presented in the NODA, this analysis showed that few 
wastes with higher TOG levels (i.e., >10 percent) were sent to 
landfills; of the 168 wastes with TOG data, only 14 had reported TOG 
levels at 10 percent or above.
    Comments on the NODA analysis argued that the data set was limited 
because most samples landfilled did not have TOG data, especially those 
that would have higher oil content (e.g., crude oil tank sediment). 
Further, commenters noted that some of the larger volumes sent to 
landfills had significant TOG levels.
    EPA disagrees. While the data set is limited, the data available 
clearly indicate that refinery wastes with relatively high oil content 
are not typically sent to landfills. In response to the comment that 
larger volumes sent to landfills had significant TOG levels, EPA 
estimated volume-weighted average TOG levels for the wastes with TOG 
data that were sent to on-site and off-site nonhazardous landfills, and 
found that these values were relatively low, i.e., less than 1 percent 
for on-site landfills and about 3 percent for off-site landfills. These 
weighted averages represent the TOG if all of these wastes were sent to 
the same hypothetical on-site or off-site landfill. EPA notes that this 
analysis of wastes sent to landfills did not consider the impact due to 
listing the wastes with the highest oil content (i.e., CSO and crude 
oil storage tank sediments) as hazardous under RCRA. After listing, 
neither waste can go to such a landfill and would no longer contribute 
to any purported co-solvency effects. Finally, as discussed above in 
response to comments on the TCLP method, even those wastes with higher 
TOG levels did not contain observable amounts of free oil, which might 
cause co-solvency. Therefore, EPA believes that co-solvency effects

[[Page 42133]]

due to oil content of the wastes under study are not likely to be 
significant.
    One commenter also argued that other compounds in wastes other than 
those under study may lead to co-solvency effects in landfills and 
provided specific refinery examples of codisposal of individual waste 
streams in 1992 and Toxic Release Inventory (TRI) data to show 
potential co-solvency effects.
    EPA disagrees with the commenter's approach to using the TRI 
database to calculate co-solvency effects at refineries. First, EPA 
notes that the TRI reporting form specifies that ``quantities reported 
on the form should . . . not reflect the total quantity of waste or 
constituents of the waste that are not subject to reporting 
requirements.'' In other words, the reported quantities are the mass 
loadings of the chemical components in land-disposed wastes and do not 
reflect the total quantity of the waste itself. Since these chemicals 
were managed in on-site Subtitle D landfills, they must have been 
components of wastes that did not exceed the TC criteria, i.e., in the 
part per billion (ppb) range. The ppb concentration range was confirmed 
by dividing the TRI loadings by the total waste quantity disposed in 
the on-site units identified by the commenter in 1992 as reported in 
the 3007 Questionnaire. Therefore, since these ``solvent-type'' 
chemicals would be only a very small component of the waste, their co-
solvency properties would be insignificant.

Laboratory and Field Methods

    Two commenters claimed that EPA's lab and field methods were 
deficient. Specifically, they believed that EPA violated basic sampling 
protocols by allowing samples to air dry prior to collection. The 
commenter specifically pointed out examples of CSO sediment with lower 
volatile organic levels than in other samples and examples of unleaded 
tank sediment with lower benzene concentrations than in other samples. 
Based on these flaws, both the total and leachable levels of volatile 
organics (e.g., benzene) were underestimated by EPA, according to the 
commenter. One commenter also argued that, by compositing samples, EPA 
may have lost substantial amounts of volatile compounds and that the 
background document does not reveal whether careful procedures were 
followed.
    The commenter misunderstood EPA's sampling descriptions which 
described the refineries' practices of air drying of storage tanks 
generating the cited wastes. This is a standard operating procedure 
designed to comply with basic occupational safety practices, so that 
refinery personnel can enter tanks for cleaning and inspection. In no 
case did EPA allow for additional air drying. EPA believes that the 
samples are representative of residuals generated throughout the 
industry. In response to the commenter's comparison of detected benzene 
levels among three gasoline tank samples, the Agency's entire sampling 
data set demonstrates a wide concentration range for several wastes. 
EPA maintains that this variability is normal, and the Agency is 
neither surprised nor concerned with the range of benzene levels 
detected in the waste samples mentioned by the commenter. Finally, 
concerning the low levels of benzene in the CSO samples, EPA disagrees 
with the commenter that benzene levels vary significantly across these 
samples. Data in the proposed rule background documents show that 
benzene was only detected in one of four samples at a level near the 
quantification limit. The levels in the other three samples were below 
the quantification limit. This means that the benzene levels were very 
low (at or below the quantification level), and thus the data do not in 
any sense show that there is significant variability.
    Field compositing procedures, when necessary, were performed for 
the non-volatile analytes only. EPA did not composite samples for 
volatile analyses, because the act of mixing the samples may lead to 
loss of volatiles by evaporation. The sampling and analysis protocols 
used were consistent with EPA's analytical guidance and were documented 
in Sampling and Analysis Plans. Careful procedures were followed in 
sampling conducted for volatile analyses and loss of volatiles was 
minimized.
    The commenters also felt that EPA did not correctly sample CSO 
sediment or HF alkylation sludge. The commenters stated that the 
practice of mixing CSO sediment with cement kiln dust (CKD) prior to 
sampling misrepresented the liquid content of the CSO sediment and EPA 
should not have dewatered HF alkylation sludges.
    In response, EPA notes that it collected samples of such wastes 
that were available after tank cleanout, and in this specific case, it 
had been mixed with CKD. This was done by the facility prior to 
landfilling of the waste. While this treatment may have altered some 
properties of this sample, the oil content (16 percent TOG) was 
relatively low, compared to the other three samples of CSO sediment 
collected by EPA (see Table 3.1.18 in the Listing Background Document, 
1995). Even if the Agency discounted entirely the analytical results 
for the one sample mixed with CKD, it would not impact the risk 
assessment significantly, because this would only raise average levels 
of some critical PAHs slightly (approximately 10-20 percent). In any 
case, EPA is listing this waste, so inclusion of this sample had no 
material impact on EPA's final decision.
    HF alkylation sludge dewatering is conducted routinely by 
refineries, and EPA collected most samples following this step. In this 
case EPA believes this waste form reflects the way the waste is 
disposed in landfills. EPA did take one sample of HF alkylation sludge 
directly from the neutralization tank and dewatered it in the 
laboratory to better simulate the characteristics of the waste as it 
would actually be generated.
2. Waste Management Assumptions
    EPA described how the Agency selected waste management scenarios 
for risk analysis in the proposed rule, and requested comments on its 
choice of plausible management scenarios. Some commenters wrote to 
support the common sense approach the Agency used in basing listing 
determinations on plausible management practices. These commenters 
stated EPA's decisions were based on current management practices and 
believed EPA obtained accurate and relevant data on the residuals and 
management practices through site visits and the 3007 Questionnaire. 
However, two other commenters suggested the Agency should evaluate 
risks from other waste management practices. These practices included 
waste management in surface impoundments, use as on-site cover for 
landfill or LTUs, use as road bed material, and storage in a pile.
    EPA does not agree that these other management practices merit 
further modeling. As EPA stated in the proposed rule, while some of 
these practices were reported for several different wastes, they 
typically involved small volumes or very few generators, and are not 
expected to present significant risk. The information collected by EPA 
shows that the vast majority of the waste volume that was disposed on 
the land went to landfills and LTUs, and the Agency focused its 
modeling efforts on these scenarios.
    The commenter specifically cited management of several wastes in 
surface impoundments (spent caustic, HF alkylation sludge, off-
specification product and fines). However, EPA does not believe these 
are significant as described in the sections on individual wastes 
(Section V.C). In general, surface impoundments at refineries are an 
integral part of the wastewater treatment

[[Page 42134]]

system, and EPA did not typically evaluate this system in detail for 
the reasons noted in the proposed rule. Briefly, risks from such 
treatment are unlikely to be of concern because: (1) treatment is 
already regulated under the National Pollutant Discharge Elimination 
System (NPDES) and air programs; (2) primary sludges generated from 
wastewater treatment are already regulated as hazardous waste (K048, 
K051, F037, F038); (3) volumes of the discharged residuals under 
evaluation are relatively small in comparison to the volumes typically 
treated; (4) the wastewater treatment systems are designed to treat 
refinery wastes effectively. Furthermore, in some cases units receiving 
the waste were not, in fact, surface impoundments, but tanks (e.g., HF 
alkylation sludges), or other concrete-lined units used as part of 
refinery processes (e.g., coke drilling pads for off-specification 
product and fines). See Section V.C for the specific wastes in question 
for further discussion, and Section V.D on the headworks exemption for 
other analyses related to wastewater treatment systems.
    Two commenters argued that the use of crude oil tank sediment and 
CSO tank sediment as landfill cover or on-site road material should be 
evaluated. One commenter stated that EPA's own preliminary assessments 
for uncovered landfills show that use of these wastes as a landfill 
cover or for on-site road material poses high cancer risks for 
subsistence farmers and home gardeners and high risks from mercury 
exposure for subsistence fishers. Finally, according to the commenter, 
it is incorrect to assume that EPA's modeling of LTUs would account for 
risks posed by road spreading or other uses constituting disposal.
    The Agency disagrees that these scenarios were not adequately 
considered, and the Agency does not believe that they would present 
significant risk. These practices were exceedingly rare, e.g., the one 
refinery which managed its crude oil tank sediment as ``cover for on-
site landfill'' in 1992 no longer uses that landfill. In addition, the 
risks for crude oil tank sediment cited by the commenter were based on 
bounding levels, and resulted from a preliminary screening analysis 
designed to overestimate possible risks for landfills. Such bounding 
estimates use worst-case assumptions for all sensitive parameters to 
screen out exposures of little concern, and to identify what pathways 
require further analysis. Furthermore, the apparent risks in the 
bounding analysis were based on incorrect biotransfer factors (used in 
beef, dairy, and plant indirect paths), which EPA has since determined 
to overestimate worst-case risks by at least two orders of magnitude. 
Likewise, the apparent problem from mercury was also traced to an error 
in units for the bioaccumulation factor used and when corrected mercury 
does not present any significant risk in these wastes. Thus, EPA 
believes that the bounding analysis was flawed and grossly 
overestimated risks. Similarly for CSO sediment, EPA also notes that 
only two refineries reported using CSO sediment in road bed material in 
1992. EPA believes that the modeled land treatment conditions are 
conservative surrogates for road spreading because: (1) The volumes and 
areas assessed for land treatment greatly exceed the reported road 
spread volumes and areas, (2) road spreading usually involves mixing 
with gravel, asphalt, dirt, etc., thereby diluting toxicants below that 
represented by the wastes modeled for land treatment and reducing risk; 
and (3) road spreading creates a stable road base, which is compacted 
and then covered by additional fill, aggregate, or pavement, making 
material less apt to wash away, erode, leach, or enter non-groundwater 
pathways than material managed by land treatment. Finally, the issue is 
moot because the two wastes specifically cited by the commenters (crude 
oil and CSO tank sediments) are being listed, thereby preventing these 
rare practices in any case.
    One commenter stated that the Agency did not properly evaluate the 
storage of wastes such as off-specification products and fines (i.e., 
coke-derived fines) in piles. The Agency's response to this issue is 
given in Section V.C for the specific waste in question. EPA evaluated 
each waste being studied to determine whether waste was being generated 
frequently enough to pose a potentially significant risk, and if so, 
whether it was appropriate to model interim storage (e.g., tanks, 
containers, piles). In most cases, the exposure risks of most concern 
are associated with long-term final disposal, and short-term storage 
was not judged to pose significant potential risk. Many residuals are 
generated infrequently, e.g., sediments from tanks are cleaned out 
about every 10 years. EPA did model interim storage of certain wastes 
that were generated more frequently when appropriate (i.e., spent 
caustic, sulfur complex sludge).
    Two commenters stated that by modeling management practices and 
volumes based only on what occurred at the time of EPA's survey in 
1992, EPA substantially understated risk and does not reflect the 
potential for waste management volumes and practices that may occur in 
the future. They argued the modeled volumes and practices are ``forever 
fixed'' and merely reflect a snapshot in time.
    EPA does not agree that the volumes and practices used in modeling 
understate risks. Based on the economic factors affecting the refining 
industry and practices observed during the Agency's field 
investigation, 1992 was a typical year for refinery operations. As 
described in the annual report issued by the Department of Energy (DOE/
EIA Petroleum Supply Annual 1992, Volume 1; May 1993), in 1992, the 
national economy was not in extremis, capacity rates were high, and 
plant closings and openings were within normal ranges. Furthermore, the 
DOE report for 1995 shows economic and production trends for crude oil 
and petroleum products. While prices for petroleum products and crude 
oil varied from 1985 to 1995, no unusual spikes or dips occurred during 
this time, and product production remained fairly constant over this 
time period.
    In addition, EPA reviewed API's Generation and Management of 
Residual Materials, 1992-1993 Appendix C, which provides trends of 
waste generation from 1987-1993. In general, 1992 was representative 
when comparing waste generation and management for the API waste 
categories and the residuals under review. Only hydroprocessing 
catalysts showed a slight increase in production that year possibly due 
to the new low-sulfur diesel regulations. In developing reasonable 
management scenarios for subsequent risk assessment modeling, EPA 
considered some potential shifts in management practices. These 
considerations are discussed in the context of each specific waste (see 
Section V.C). For the remaining residuals, EPA considered the industry 
to be stable, and thus assumed that 1992 provided a reasonable picture 
of the petroleum refining industry's practices. EPA's approach was not 
``forever fixed'', but used 1992 as a reasonable starting place for 
assessing the industry's waste generation and management practices.
    Finally, EPA notes that its survey of refineries was a complete 
census of the industry, and gathered information from all active 
petroleum refineries in the United States. It is reasonable for the 
Agency to conclude that the large amount of information gathered in its 
1992 survey of petroleum refineries related to waste generation, 
management, and disposal practices is representative of such practices 
in any year. While individual refineries may change practices in any 
given year, the overall pattern of these practices,

[[Page 42135]]

including waste volumes and the potential environmental risks posed, 
are unlikely to change significantly for the industry as a whole. 
Therefore, EPA has no reason to believe that 1992 was not a 
representative year.
    The commenter also stated that waste volumes modeled in the NODA 
risk assessment were inappropriate because the individual waste volumes 
modeled for land treatment were typically much smaller than modeled for 
landfilling, even though there is no legal or technical bar for the 
wastes to be managed in either fashion during any given year. The fact 
that refineries relied upon land treatment less in 1992 is not 
necessarily indicative of future practices.
    In response to the commenter's concern regarding the 
transferability of wastes between land treatment and landfilling, EPA 
notes that a refinery may choose different disposal practices based on 
a variety of considerations, two of which are particularly important. 
First, the refinery must consider the waste's characteristics. Wastes 
with higher liquid content are more likely to be land treated due to 
the moisture requirements of the land treatment process, while 
dewatered wastes are more likely to be landfilled due to cost and waste 
volume constraints (e.g., more waste costs more), and liquid content. 
This is supported by the data collected in the 3007 Questionnaire, 
which show that wastes sent to land treatment contain on average higher 
TOG and water than wastes sent to landfills. The average oil and water 
content reported for landfilled wastes were 5.9 percent and 7.5 percent 
respectively, compared to average oil and water levels of 14 percent 
and 17 percent for land treated wastes. The second important 
consideration regarding the transferability of wastes between landfills 
and LTUs is availability of the two disposal methods for each refinery. 
Certainly, on-site Subtitle D LTUs are rather limited and may not be 
available to many refineries. As described in information EPA provided 
in the NODA, EPA's database showed only one facility with both on-site 
nonhazardous landfill and nonhazardous LTUs (see Supplemental 
Background Document-Listing Support Analysis, April 1997 in the docket, 
p. 15) and only six nonhazardous LTUs for all refineries (ibid., p. 
30). Thus, to project that large volumes of waste would shift between 
landfills and LTUs appears implausible. Finally, assuming for the sake 
of argument that such shifts did occur, it is possible that any change 
in waste management practice for one refinery would be offset by the 
opposite change by another refinery, in effect balancing out any 
changes from year to year.
3. Codisposal of Wastes
    Two commenters noted that the waste volumes do not reflect either 
the actual or potential for codisposal of wastes (i.e., disposal of two 
or more wastes in the same unit). Such codisposal of the wastes is 
found in several instances in EPA's database for on-site and off-site 
units receiving these wastes. The commenters argued that codisposal 
would increase risks for the individual wastes evaluated by EPA, 
because the greater volumes would release more toxic constituents. The 
commenters noted that EPA found waste volume to be an important 
parameter, especially in the groundwater model.
    In response to these comments EPA first notes that its modeling for 
the proposed rule and NODA did, in fact, combine volumes in cases where 
the same landfill accepted multiple portions of the same waste stream 
for disposal. Thus, volumes of the same residual sent to the same 
landfill were aggregated and placed into the waste volume distribution 
for use in modeling. In response to this comment, however, EPA expanded 
its analysis in the NODA to include codisposal of all 14 residuals 
examined for this listing determination that were landfilled, as well 
as another set of 15 refinery wastes that were under study. This 
analysis excluded only (1) wastes that were proposed for listing, 
because they could no longer be placed in a nonhazardous landfill 
(spent hydrotreating and hydrorefining catalysts), and (2) any wastes 
that were not landfilled at all (e.g., spent caustic). EPA combined the 
waste constituent and TCLP data for individual wastes by weighing the 
concentrations determined for each waste according to the volume of the 
wastes used. Thus, volume weighted waste and TCLP concentrations were 
used to construct a hypothetical scenario of all these wastes being in 
one generic on-site or off-site landfill. The codisposal analysis 
showed risks below 1E-5, which EPA does not view as significant. 
Revising this assessment to reflect the changes in the off-site 
landfill scenario as described elsewhere in this Section, the high-end 
risks were 8E-6, and remain below 1E-5 (see Table IV-2).
    However, comments on the NODA argued this analysis was flawed, 
because EPA used only median volumes for each waste, and did not 
undertake a full sensitivity analysis for the high-end risk analysis. 
In response, EPA notes that the NODA also presented a Monte Carlo 
analysis of the codisposal scenario, which used the full volume 
distribution for these wastes, not just the median volumes, and even at 
the 99th percentile, the Monte Carlo risk was below 1E-5. After 
revising the input parameters and Monte Carlo assumptions for off-site 
landfills as described earlier in this Section, the Monte Carlo risks 
remain low (3E-6 at the 95th percentile; see Table IV-2).
    Commenters also argued that EPA's codisposal approach did not 
consider codisposal with other refinery wastes in landfills that are 
not under examination by EPA in the listing determination or the study. 
One commenter submitted analysis that attempted to account for the on-
site codisposal of the wastes under study by increasing the combined 
waste volume to include on-site landfill volumes reported in the 3007 
Questionnaire. The commenter also assumed that each waste was sent to 
the same landfill for 40 years. These assumptions resulted in an 
increase of about 5-fold in the total volumes modeled. However, the 
commenter noted merely increasing this volume alone did not 
significantly increase risks for the codisposal scenario. The commenter 
went on to assume that the codisposed wastes (i.e., the wastes that 
were not part of EPA's current listing determination or study) would 
contain sufficient benzene to leach at one-half the TC (i.e., 0.25 mg/
L). The commenter's analysis also made other changes to EPA's modeling 
assumptions, including assuming all wastes leach benzene with an 
efficiency of 53 percent, and that the receptor well is located on the 
centerline of the plume of contamination (see discussion later in this 
Section on groundwater issues). With these further set of assumptions, 
the commenter estimated high-end risks up to 4E-5.
    EPA does not find the commenter's codisposal analysis compelling 
for several reasons. First, the assumption that the codisposed wastes 
will all leach at one-half the TC level is speculative and without 
foundation. In fact, the existing data available to EPA for the 
refinery wastes under study show that very few of these wastes contain 
such high levels of benzene. EPA has no valid reason to project that 
benzene levels in other codisposed wastes would be drastically 
different, as assumed by the commenter. Also, EPA does not agree with 
other modeling assumptions used by the commenter, and the Agency has 
arrived at a different conclusion in its modified risk analysis. As 
noted later in this Section, EPA believes the commenter's assumption 
about well location and landfill active life are incorrect. (EPA used a 
30-year life and

[[Page 42136]]

treated well location as one of the variable parameters). EPA's revised 
high-end and Monte Carlo analyses did not change significantly (see 
Table IV-2), even when using the larger volume inputs. This is 
consistent with the commenter's initial results, as noted above. 
Furthermore, EPA notes that the final listing decisions would tend to 
lower any codisposal risk, because of EPA's final listing of two other 
wastes as hazardous, crude oil, and CSO tank sediment. Both contributed 
leachable benzene to the codisposal analysis performed by EPA (and the 
commenter), thus with these wastes removed from any possible codisposal 
with the remaining wastes, any risks from codisposal should be lower 
than estimated with them included.
    Finally, EPA questions how relevant such a codisposal analysis 
would be, even if it could be done to the commenter's satisfaction. EPA 
is not attempting to list landfills that may contain a variety of 
wastes, but rather the Agency is trying to determine whether an 
individual waste merits listing, based on the incremental risk posed by 
a specific waste. To properly factor in all wastes that are in each 
landfill would require extensive site-specific information that would 
be essentially impossible to gather, and would require speculation 
about what wastes would be sent to a disposal unit and how long 
disposal of such wastes would occur. This could create an analysis 
difficult to interpret for use in listing determinations. In any case, 
this is not necessary to protect human health and the environment, 
because EPA's analysis shows the risks from codisposal are below levels 
of concern.
    EPA also evaluated the impact of codisposal on the risks from land 
treatment of the wastes under study, and provided this analysis in the 
NODA. Constructing a hypothetical LTU that contains all of the wastes 
so managed is unnecessary, given the very limited number of 
nonhazardous units that are available for land treatment. Of the 172 
refineries in the 3007 Questionnaire, only 13 nonhazardous units were 
reported to receive any of the residuals of concern ( 6 on-site and up 
to 7 off-site LTUs). The risks from land treatment of individual wastes 
were dependent on the PAH content in the waste, thus the waste with 
high PAH content, CSO sediment, yielded significant risks when 
evaluated by itself. As shown in the land treatment risk analysis in 
the NODA, none of the other wastes when evaluated individually had 
risks approaching 1E-6. EPA found only one on-site LTU and three off-
site LTUs that received more than one waste under study in 1992 
containing any PAHs of concern. Because of the limited codisposal found 
in LTUs, EPA examined the potential risks from the actual disposal 
reported, assuming that wastes proposed for listing (most notably CSO 
tank sediment) were removed. Because few other wastes had appreciable 
PAH content, the codisposal analysis yielded negligible risk. Crude oil 
storage tank sediment was included in the codisposal analysis, however, 
EPA has since decided to list this waste. Therefore, removing this 
waste, which contains moderate levels of PAHs, from any codisposal 
analysis would further reduce the likelihood that codisposal of the 
unlisted wastes in LTUs will yield significant risk.
4. Impact of Hazardous Characteristic Regulations

Wastes Exceeding the TC

    Some commenters stated that the risk assessment in the proposed 
rule overstates the risks from benzene and arsenic (the key 
constituents of concern for the wastes proposed for listing) because 
EPA included benzene and arsenic TCLP concentrations in excess of the 
TC limit for these compounds. The commenters suggested that EPA should 
calculate groundwater risks from Subtitle D landfill disposal of crude 
oil tank sediments and spent hydrotreating/hydrorefining catalysts by 
using only the data that does not exceed the TC limit. Commenters noted 
that EPA's risk assessment assumed that no RCRA Subtitle C controls 
were in place for any of the management scenarios; therefore, including 
any waste samples that exhibited the TC (i.e., for benzene) in the risk 
assessment would lead to unrealistically high risk.
    To respond to the commenter's concerns, the Agency presented 
further analysis in the NODA resulting from groundwater modeling runs 
in which the input TCLP data for wastes that exceeded the TC threshold 
were ``capped'' at the TC level. Thus, EPA used the assumption that 
wastes could contain toxic constituents at or near the TC threshold, 
and that such data should be included in the risk assessment. EPA notes 
that the groundwater risk analysis in the proposed rule, as well as in 
subsequent analyses, did not include waste volumes reported in the 3007 
Questionnaire to be hazardous and sent to hazardous waste Subtitle C 
landfills in the volume distributions used in modeling risks from 
nonhazardous Subtitle D landfills. EPA believes this is reasonable 
because these volumes were handled as hazardous and would not affect 
risks from Subtitle D units. This point is discussed further in the 
following section in the context of comments on volumes used in 
modeling LTUs.
    The final revised groundwater analyses (see Table IV-2) showed some 
reduction in risks, using the TC-capping assumptions. However in all 
cases the high-end risks for these TC-capped runs exceeded the 1E-5 
risk level for both benzene and arsenic. The 95th percentile Monte 
Carlo risks also exceeded 1E-5 for one key constituent (arsenic) for 
the spent hydrotreating and hydrorefining catalysts analysis. The TC-
capping has essentially no effect on groundwater risks from arsenic in 
these catalysts, and the modeling results for these specific wastes are 
discussed in more detail below and in Section V.C.3.
    Two commenters responded to the Agency's analysis on the capping of 
waste concentrations at the TC levels by arguing that EPA's ``cap'' was 
too high, and provided alternative methods that would result in lower 
input values for benzene and arsenic for the spent hydrotreating and 
hydrorefining catalyst wastes. EPA had capped the average TCLP input 
data for the high-end analysis at the TC level, while the commenters 
suggested capping each individual sample before averaging. The 
commenters noted that EPA's Monte Carlo analysis used the original TCLP 
data and substituted the TC threshold for individual values that 
exceeded the TC. Using the approach applied by EPA in the Monte Carlo 
analysis, the commenters calculated that the average TCLP 
concentrations decreased to 60 percent of the TC level used in the 
high-end analysis.
    The Agency believes that its approach is more appropriate for the 
conservative high-end risk analysis, but notes that the Monte Carlo 
analysis, effectively, does what the commenter suggests. The Agency 
performed the TC-capped analysis to assess the level of risk that might 
occur, assuming wastes that exceed the TC threshold are managed as 
hazardous wastes. Therefore, EPA believes that capping the actual input 
to the high-end model is appropriately conservative. As discussed in 
detail in the discussions for specific residuals (see Section V.C), the 
Agency believes that even the Monte Carlo TC-capping analyses support 
listing these wastes.
    For the catalysts, EPA notes that using this alternative approach 
in the high-end analysis is unlikely to affect the listing decision 
because: (1) the pyrophoricity of the wastes supports listing these 
wastes, (2) the arsenic risks would remain very high under either TC-
capping approach, and (3) the high-

[[Page 42137]]

end risks for benzene remain of concern. To explain the second point, 
EPA notes that the TC-capping has no effect on hydrotreating catalyst 
because none of the samples exceed the TC level for arsenic. For 
hydrorefining catalysts, which did have some values above the TC level, 
even if the lower average arsenic input levels assumed by the 
commenters were used, the arsenic risks would remain above 1E-4. (Note 
that the risk results are not very sensitive to the TCLP input level 
for arsenic under the conditions modeled, because this chemical moves 
very slowly in groundwater, causing the maximum receptor well 
concentration to be relatively insensitive to the starting leaching 
concentration.)
    Another commenter objected to capping waste samples at the TC 
level, particularly for benzene, arguing that this implies the toxicity 
characteristic may be an appropriate alternative to listing the wastes. 
The commenter stated the TC-capped modeling and the underlying 
implications are wrong because (1) the TCLP is unreliable for oily 
wastes, (2) a generator may apply ``knowledge'' in lieu of testing, (3) 
generators may render inaccurate determinations, and (4) the 
characteristic does not consider the high PAH content of some wastes.
    EPA generally agrees that for the wastes at issue, crude oil tank 
sediment and spent hydrotreating/hydrorefining catalysts, the TC does 
not provide sufficient regulatory control for the various reasons 
stated in the residual specific discussions in Sections V.C. As shown 
by the TC-capped modeling analysis, the risk levels remain at levels of 
concern, whether or not EPA assumes wastes exceeding the TC levels 
would be managed as hazardous. Furthermore, as discussed later in this 
section on the use of the TC as an alternative to listing, EPA believes 
that listing these wastes is supported by other factors.
    EPA does not agree with the commenter's claim that the TCLP is 
unreliable for the wastes evaluated in today's rule (see discussion at 
the beginning of Section V.B.1). While EPA agrees that inaccurate 
determinations by generators may occur due to the difficulties 
associated with sampling some wastes (see discussion in Section V.C.1), 
the Agency believes that the use of a generator's knowledge in lieu of 
testing is appropriate in many cases. Finally, the Agency agrees that, 
to the extent potential risks from PAHs are not controlled by the TC, 
wastes should be listed. This may occur because PAHs are not TC 
constituents, as noted in the following section on use of the TC as an 
alternative to listing. Therefore, if a particular waste exceeds TC 
levels only some of the time, any PAH risks would not be adequately 
covered for those instances where the waste does not exceed the TC 
levels.

Eliminating Hazardous Waste Volumes

    In allocating volume inputs for the groundwater and nongroundwater 
modeling, EPA omitted waste volumes that were reported to be hazardous 
(i.e., exhibited a characteristic defined in 40 CFR 261.24). EPA had 
not done this in the proposal for wastes sent to land treatment, and 
for inadvertently modeled hazardous waste volumes that were, in fact, 
disposed of in permitted hazardous waste LTUs. EPA corrected this in 
the risk analysis for land treatment presented in the NODA. One 
commenter disagreed with EPA's approach of not counting waste volumes 
managed as hazardous in 1992, and noted this dramatically reduced the 
high-end volumes of crude oil storage tank sediment used as input to 
the NODA risk assessment for land treatment disposal. The commenter 
stated that the ``recalculations'' for land treatment volumes are based 
on the unverified assumption that because certain wastes were managed 
in 1992 as hazardous, they will always be managed as hazardous. The 
commenter argued that by excluding these wastes, EPA is implicitly 
relying on the existing TC in lieu of listing the waste, and therefore 
making the same policy errors as the landfill TC-capping modeling 
(discussed above).
    EPA does not agree with this comment. The wastes that were excluded 
for the revised land treatment modeling were, in fact, reported to be 
hazardous in the 3007 Questionnaire. While some wastes may exhibit a 
characteristic sometimes, and not at others, EPA has no reason to 
believe that 1992 was not a typical year. Thus, EPA could reasonably 
assume that similar amounts would be hazardous from year to year, and 
such variation should not lead to significant changes in the risk 
analysis. While excluding these volumes does rely on the TC as the 
commenter noted, this reliance seems justified because these wastes 
did, in fact, exhibit the TC and were reported to be managed as 
hazardous. Furthermore, EPA notes that the waste of primary concern to 
the commenter, crude oil tank sediment, is being listed as hazardous in 
any case due to groundwater risks from landfill disposal. For the other 
wastes modeled in LTUs, removal of volumes regulated as hazardous did 
not alter the risk results significantly, i.e., the median and 90th 
percentile volumes were only slightly different (see Table 2.1 in the 
NODA nongroundwater risk assessment background document, Supplemental 
Background Document; Nongroundwater Pathway Risk Assessment, March, 
1997).

Use of the TC as an Alternative to Listing

    Some commenters indicated that the use of the TC adequately 
regulates potential risks, and therefore, makes listing of the refining 
process residuals unnecessary. Others commented that the TC does not 
adequately capture wastes that should be regulated, and supported the 
proposed listings.
    In response, the Agency notes that its listing decisions are based 
on a weight-of-evidence approach, which evaluates various factors, 
including the results of the risk analysis. In general, EPA may 
consider listing wastes that frequently exhibit a characteristic if 
risks are not adequately controlled by the characteristic. The TC, for 
example, was based on an evaluation of potential threats constituents 
may present if released to groundwater (see 55 FR 46369; November 2, 
1990). Thus, for a waste that is TC hazardous, EPA may consider listing 
if other pathways besides groundwater present a risk, if other 
constituents in the waste are not included in the list of TC 
constituents, or if a waste with levels of TC constituents below 
characteristic thresholds still shows significant risk for some 
situations.
    In today's rule, EPA is finalizing listings for the two spent 
catalysts and crude oil tank sediment, even though these wastes are 
often characteristically hazardous, because risks from landfilling 
these wastes are not adequately controlled by the TC (see specific 
waste discussions). Furthermore, EPA is listing another waste, CSO tank 
sediment, that often exhibits the TC characteristic for benzene, 
because the TC does not effectively control risks presented by PAHs in 
LTUs via nongroundwater pathways. The TC was developed to provide 
protection against potential risks from the contamination of 
groundwater by leachate from land disposal units, and was not designed 
for nongroundwater pathways. In addition, PAHs are not on the list of 
TC constituents.
5. Other General Risk Issues

Consistency With Past Listings

    One commenter stated that EPA's methodology for the current listing 
determination is inconsistent with previous Agency practice and policy,

[[Page 42138]]

specifically with the finalized carbamates listing and the previous 
petroleum listing. The commenter noted that, for the carbamates listing 
rule (February 9, 1995; 60 FR 7825), EPA computed landfill waste 
volumes according to the quantity of wastes that could be landfilled, 
not just the quantity that happened to be landfilled in the reporting 
year. The commenter provided examples in the current listing proposal 
where waste volumes for land treatment exceeded the volumes for 
landfilling, and argued that the volumes used in the landfilling 
assessment were therefore too small. The commenter also noted that EPA 
considered the codisposal of solvents and other oily wastes in 
petroleum refining waste management units as part of its 1990 listing 
determination for refinery wastewater treatment sludges, F037/F038 
(November 2, 1990; 55 FR 46354).
    As a general response, EPA notes that the commenter did not take 
into consideration the evolving nature of the Agency's risk assessment 
process and policies. EPA's risk methodologies have progressed over the 
years, and the modeling tools have been refined. The earlier rule cited 
by the commenter, the listing decision for treatment sludges (F037/38), 
did not, in fact, rely on modeling, but rather used a more simplistic 
approach based on a comparison of waste constituent concentrations to 
health-based levels. Given the modeling tools currently available, EPA 
no longer believes such an approach is appropriate, because it does not 
take into account the potential for waste constituents to be released 
from the waste units, their fate and transport in environmental media, 
and the levels to which receptors may ultimately be exposed. In today's 
rule, EPA has used various models to estimate the release and transport 
of the toxic chemicals of concern, and the Agency believes such an 
approach is more useful in projecting the potential risk to exposed 
individuals.
    While EPA did perform modeling as part of its risk assessment in 
the carbamates listing cited by the commenter, this was essentially the 
first time the Agency attempted to use such modeling to support listing 
decisions. Thus, EPA made various simplifying assumptions. For example, 
EPA created a hypothetical off-site landfill for modeling by assuming 
that all of the carbamate wastes under examination would be placed in 
the same off-site unit. Such a simplifying assumption would be 
unrealistic in the current rulemaking, given that the petroleum 
refining industry consisted of 185 facilities in 1992, and that these 
facilities were widely distributed throughout the country (for 
comparison, the carbamates industry comprised 23 facilities). To use 
the same approach as was used in the carbamates rule, i.e., to assume 
disposal of all wastes in one landfill, does not appear reasonable in 
the current rulemaking.
    Therefore, EPA believes that the approach used in today's rule is a 
reasonable progression of EPA policy. For responses to the specific 
comments related to the use of volumes reported for land treatment and 
landfills, see the discussion on Waste Management Assumptions, which 
appears earlier in this section. Elsewhere in this rule EPA also 
responds to comments related to codisposal (Section V.B.3) and co-
solvency (Section V.B.1).
    The commenters also argued that previous listing determinations 
were based on lower levels of contaminant concentrations than those 
found in wastes being considered in this notice, and that the wastes 
under consideration in this rulemaking should be listed. For example, 
the commenter pointed out that the average total concentration of 
benzene and PAHs, such as benzo(a)pyrene found in crude oil tank 
sediment exceeds the level of benzene in F037 and F038 that caused 
those wastes to be listed in 1990.
    EPA recognizes that crude oil tank sediment and other residuals 
characterized in this listing determination may contain concentrations 
of some constituents comparable to previously listed wastes, including 
the F037 and F038 refinery residuals. However, direct comparison of 
these concentrations to previous listing benchmarks is not an adequate 
basis for listing. Listing determinations consider many factors beyond 
the concentrations of constituents in a waste, including the waste 
volume, constituent mobility, management practices, damage cases, other 
regulatory controls, etc. (see 40 CFR 261.11(a)(3)). As noted above, 
the listing of F037/F038 sludges did not use modeling for support, but 
instead relied on constituent concentrations, as well as various other 
factors. The other factors that EPA relied on in this listing included 
the very large volumes of F037/F038 generated (over 400,000 metric tons 
per year), the widespread use of surface impoundments to manage the 
wastes, and damage cases. Therefore, merely comparing constituent 
levels may not provide a useful measure of what wastes should be 
listed. Furthermore, as noted above, EPA's risk assessment process has 
evolved, and the Agency has developed a more sophisticated set of risk 
assessment tools than were available for listing determinations in 
1990. As a result, EPA believes that it is better able to measure and 
predict risk now than previously, and that the better procedures and 
methodologies should be used.

Individual Versus Population Risk

    Several commenters stated that the population risks estimated by 
EPA do not justify a decision to regulate the wastes proposed for 
listing (hydrotreating and hydrorefining and clarified slurry oil 
sediment), and that consideration of the risks posed by these landfills 
to the entire population potentially exposed would lead to the 
conclusion that these residuals do not pose substantial hazards to 
human health, and thus, should not be listed as hazardous wastes. 
Commenters argued that EPA's failure to give serious consideration to 
the low levels of population risk is at odds with the statute, the 
listing criteria, and regulatory precedent within the federal 
government. The commenters claimed that, due to the low populations 
risks, EPA cannot conclude that any of these residuals ``is capable of 
posing a substantial present or potential hazard to human health or the 
environment,'' as required in 40 CFR 261.11, and should not list any of 
these residuals.
    In response, EPA notes that ``population risk'' is not explicitly 
used in either the RCRA statute or the hazardous waste listing 
regulations in 40 CFR 261.11. EPA does not believe it is appropriate to 
allow contamination from waste management units to cause substantial 
risk to nearby residents simply because there are few wells in the 
immediate area. In addition, the regulation cited by the commenter 
clearly states that wastes are to be listed if they are ``capable of 
posing a substantial present or potential hazard'' (emphasis added). 
Thus, the Agency must protect against potential, as well as present 
risks that may arise. The Agency's decision to list these wastes is 
based primarily on the concern over risks to those individuals who are 
significantly exposed, even if there are relatively few of them.
    Population risk is only one of many factors to be considered in 
Agency decisions, and there are numerous precedents where the Agency 
has taken action, for example at Superfund sites and in previous 
listing determinations, when there are relatively few people 
potentially affected. See, for example, the report entitled Land and 
Soil Health Risks from CERCLA (Federal Superfund), and WQARF (State 
Superfund) Sites, Arizona Department

[[Page 42139]]

of Environmental Quality, 1995, in the docket for today's rule, which 
concluded that population risks were low because the number of people 
exposed to groundwater contamination is small. The Agency has stated 
that the key objective of the CERCLA National Contingency Plan (NCP) is 
to protect individuals at contaminated sites (see 55 FR at 8710), and 
rejected using population risk as the point of departure for setting 
clean-up levels (see 55 FR at 8718). In addition, the CERCLA 
regulations (see 40 CFR 300.430(e)(2)(i)(A)(2), and 55 FR at 8848) 
direct EPA to establish preliminary remediation goals for carcinogens 
based on ``cancer risks to an individual.''
    Population risks arising from contaminated groundwater due to waste 
management are expected to be low, because often only a limited number 
of domestic wells will be near these facilities, and groundwater moves 
very slowly. EPA's Guidance for Risk Characterization (USEPA Science 
Policy Council, February, 1995) states that, when small populations are 
exposed, population risk estimates may be very small, however, ``in 
such situations, individual risk estimates will usually be a more 
meaningful parameter for decision-makers.'' Finally, it is important to 
note that the Agency is also concerned about the loss of the 
groundwater resource for the future, which could be of particular 
concern if land use patterns were to change and there were a future 
demand for the resource. In this case, beneficial uses would be 
precluded or, if the potential users were unaware of the contamination, 
risks could occur.

Additive Risks From Multiple Units

    One commenter stated that risks posed through different groundwater 
and nongroundwater pathways should be summed when the potential for 
simultaneous exposure exists, but that EPA instead assumed that 
groundwater exposures were occurring after the nongroundwater 
exposures. The commenter noted that the time of travel for benzene and 
perhaps other mobile constituents in EPA's groundwater risk assessment 
is 17 years or less, clearly within the period of time nongroundwater 
exposures may occur.
    EPA does not agree with the commenter's suggestion that groundwater 
and nongroundwater risks should be combined. This is because, as 
discussed previously, EPA's analysis showed that groundwater risks are 
only potentially associated with landfills, and nongroundwater risks 
are only potentially associated with LTUs. Therefore, the only 
potential for the combination of groundwater and nongroundwater risks 
to be significant, would be for a situation in which a landfill was 
located in close proximity to a LTU. EPA examined the information 
provided in the 3007 Questionnaire for any sites where landfills and 
LTUs are co-located, and presented the results in the April 1997 NODA. 
This analysis showed only one facility at which a nonhazardous LTU and 
landfill were both located at the same site, and even in this one case 
the units are approximately 5,000 feet apart, making significant 
simultaneous exposure unlikely.
6. Specific Groundwater Modeling Issues

Active Life of Landfills

    Two commenters disputed EPA's assumption of 20 years for the active 
life of landfills to estimate the total volume of a specific waste 
placed in a landfill, and argued that the report and data for off-site 
landfills used by EPA to make this assumption (National Survey of Solid 
Waste (Municipal) Landfill Facilities, EPA/530-SW88-034, September 
1988) actually demonstrate an active life of at least 40 years. The 
commenters believed that this is an important difference, because this 
would increase the total waste volume used as input to the groundwater 
models and result in increased risks.
    In response, EPA reexamined the report cited and concluded that the 
assumed active life of 20 years may be an underestimate. Using the data 
in the report, however, the Agency calculated that an average active 
life of 30 years is more appropriate for us in the risk assessment, 
rather than the 40-year life suggested by the commenter. EPA believes 
that the commenter simply summed the reported average age of the 
landfills (19 years) and the average remaining life (21 years) to 
obtain 40 years. However, this calculation is not appropriate, because 
it would overestimate the active life for existing units. This is 
because the average age in the report included closed units, not only 
existing units, and thus does not reflect the average life for those 
units still in operation. Likewise, the average remaining life given in 
the report included planned units, as well as existing units, and this 
also would tend to inappropriately increase the apparent active life 
for existing units. Correcting for this by eliminating closed and 
planned units, EPA calculated a 30-year active life, based on corrected 
values of 16.5 years for the average age of active units, and 13.3 
years for the average remaining life of active units (see Additional 
Listing Support Analysis, 1998, in the docket to today's rule for full 
calculations). EPA has used the revised active life (and 
correspondingly larger volumes) to calculate the new risk numbers given 
in Table IV-1.
    The same commenters also argued that EPA's use of a 20-year life 
for on-site landfills was wrong. In the NODA, EPA provided an analysis 
of the data for on-site landfills for refineries from the 3007 
Questionnaire, showing a calculated median of about 21 years for on-
site landfills. The commenter continued in comments on the NODA to 
dispute the 20-year calculation, and cited an alternative method 
presented by EPA in the NODA to calculate a 39-year average (i.e., 
mean) active life, which the commenter argued EPA should use.
    In the NODA analysis, the Agency used the projected date for 
closure of on-site landfills reported by refineries in the 3007 
Questionnaire to estimate active lives. EPA also examined an 
alternative method to calculate on-site landfill life for use when 
facilities did not report the projected date of closure. Under this 
alternative method, EPA used the remaining capacity reported for the 
units, assumed disposal rates for all wastes in the landfills would 
remain constant, and thereby estimated when the landfill may reach full 
capacity. EPA believes the direct method chosen is most appropriate 
because it uses the actual landfill lives reported in the 3007 
Questionnaire, rather than relying on estimating remaining active life 
by projecting past waste disposal rates into the future. The 
alternative approach is especially uncertain when the landfill is 
relatively new, thereby requiring the extrapolation of a small 
percentage of used landfill capacity into the far future, which means 
that small variations or errors in the used capacity of a landfill may 
lead to widely varying landfill life projections. Thus, EPA did not 
revise its modeling for on-site landfills to reflect a longer landfill 
life. EPA also used the median active life, rather than the mean 
suggested by the commenter, because the median value lessens the impact 
of widely variable data and outliers. For example, a few very large 
values in a data set would have a major impact on the mean, but the 
median would not be overweighted by the few very large values. EPA 
notes that the only data available for off-site municipal landfills 
were average values, not medians, so the Agency had no choice but to 
use the average estimate active life for the off-site landfills.
    Furthermore, EPA notes that many of the wastes of concern, such as 
the

[[Page 42140]]

sediments from storage tanks, are generated only intermittently, since 
facilities clean out crude oil storage tanks about every 5-10 years. 
While refineries may have many such tanks of different ages, EPA 
estimates that a typical refinery may generate such a clean out waste 
about every 1.5 3 years. In effect, a typical facility may not dispose 
of the tank sediments in on-site units every year, but approximately 
every 2 years. Therefore, even assuming arguendo that the on-site 
active life might be about 40 years, as the commenter suggested, if 
tank sediment is only generated every two years or so, the total volume 
of a specific waste in the unit may more closely resemble 20 years 
worth. EPA notes that, unlike on-site units, off-site landfills may 
accept waste from other refineries, thus disposal may well occur every 
year. Therefore, the 30-year active life used for off-site units is a 
more appropriate measure of the number of years a specific waste may be 
disposed.
    Finally, EPA notes that because the revised risks from off-site 
landfills were somewhat greater than risks from on-site landfills for 
the wastes of most concern to the commenter that the Agency is not 
listing (i.e., unleaded gasoline tank sediment, and HF alkylation 
sludge), the off-site risks are likely to be determinative in any case.

Waste Unit Area

    Two commenters believed EPA should have used larger waste unit area 
sizes in its groundwater risk assessment, and that this would result in 
the listing of more refinery wastes. These commenters questioned EPA's 
decision to vary on-site landfill sizes for different petroleum wastes 
when projecting mismanagement scenarios. The commenters argued that 
since any petroleum waste can be disposed in any on-site landfill, EPA 
should assume that any waste will be disposed in units representing the 
largest landfills. The commenters believe that a larger waste unit area 
would result in a higher concentration at the receptor well, and that 
EPA underestimated the risk associated with several of the wastes the 
Agency decided not to list.
    In response, EPA notes it used waste quantity and on-site landfill 
sizes in the modeling analysis for individual waste streams from the 
RCRA 3007 Questionnaire responses, which are based on actual petroleum 
waste management practices. EPA disagrees that a refinery would 
necessarily use a landfill to dispose of any number of wastes, and the 
Agency believes that there are indeed reasons why a facility would not 
dispose all its generated waste in an on-site landfill, including 
permit limitations and liability considerations. EPA verified such 
limited or segregated management practices during site visits. For 
example, EPA reviewed site visit reports for four facilities that 
operated on-site nonhazardous landfills. Two facilities manage 
Fluidized Catalytic Cracking (FCC) catalyst and fines, but no other 
listing or study wastes in their landfills. The other two operate the 
on-site landfills for disposal of only some of their generated wastes. 
Other wastes are disposed off-site or recycled. EPA believes its 
approach of calculating different unit areas for different wastes was 
reasonable because they are reflective of actual operating practices, 
and another approach may result in unrealistic or unreasonable 
assumptions regarding waste management practices. As noted in the above 
section on waste management assumptions, a refinery may choose 
different disposal practices based on a variety of considerations, 
including the waste's characteristics and access to landfill capacity. 
Furthermore, it is not necessarily true that the larger the landfill, 
the higher the resulting receptor well concentration. The modeled 
receptor well concentration is a function of a number of parameters, 
such as waste volume, leachate concentration, the concentration of 
constituent in the waste, and various chemical transport properties. 
Thus, for a given waste volume, a larger landfill area will not 
necessarily produce higher well concentrations.
    The commenters also stated that the standard off-site landfill 
areas used by EPA were arbitrarily small (2,020 square meters 
(m2) median; 162,000 m2 high-end). The commenters 
noted that EPA apparently derived these area sizes from an industrial 
landfill survey taken of on-site industrial waste landfills, and 
therefore the areas are inappropriate to use for off-site units. The 
commenters went on to state that the Agency should use data available 
for municipal solid waste landfills for the off-site modeling, (i.e., 
the same database EPA relied on for length of active life.) They noted 
that the areas reported for active municipal waste landfills in EPA's 
1988 survey appear many times greater than the volumes used by EPA.
    EPA agrees first that the median area used by EPA in this analysis 
was in error, and believes that the data for off-site municipal 
landfill area cited by the commenter are more appropriate for modeling 
off-site landfills than the industrial database used by the Agency. 
This is primarily because, as the commenter noted, the database 
originally used by EPA reflected landfill areas collected from what are 
likely industrial on-site landfills, rather than off-site landfills. 
EPA does not have, at this time, any area data for off-site industrial 
nonhazardous landfills, so the Agency has decided to use the data 
available for off-site municipal landfills. The use of municipal 
landfill data is entirely appropriate because the refineries reported 
in the 3007 Questionnaire that close to one-half of the wastes disposed 
off-site went to municipal landfills. Therefore, EPA revised the 
groundwater modeling for off-site landfills to reflect the larger areas 
associated with municipal landfills, and the risk results in Table IV-2 
incorporate the revised landfill areas.

Noningestion Exposures for Groundwater

    One commenter stated that EPA's groundwater risk assessment only 
considered the impact of ingestion of the water, but ignored potential 
risks from inhalation and dermal absorption of contaminants that might 
arise from the use of water in the home (e.g., showers or bathing). 
Such an additive affect would increase the overall risks from 
groundwater exposures.
    EPA agrees with the commenter that the noningestion exposure route 
for groundwater may be important for some constituents. The Agency 
presented its analysis of such noningestion risks in the NODA. For the 
wastes under study, this was only significant for benzene (no other 
toxic constituent of concern was volatile enough to affect the risk 
evaluation). EPA's analysis resulted in effectively increasing risks 
from benzene projected to reach a receptor well by about 60 percent 
over the ingestion risk (See Chapter 5, Supplemental Background 
Document for Groundwater, 1997.)

Biodegradation of Benzene

    Five commenters argued that the biodegradation of benzene should be 
considered in estimating the potential risks from Subtitle D 
landfilling of spent hydrotreating catalyst, spent hydrorefining 
catalyst, and crude oil storage tank bottom sediment. Two commenters 
used the groundwater model used by EPA (EPACMTP) to show that 
concentrations of benzene in groundwater decrease when a conservative 
biodegradation rate is assumed. Several commenters calculated benzene 
biodegradation rates to show that both anaerobic and aerobic 
biodegradation processes limit the subsurface transport of benzene in 
particular, and related aromatic hydrocarbons in general (benzene,

[[Page 42141]]

toluene, ethylbenzene, and xylenes, also known as BTEX). Commenters 
believed that the studies are relevant because the levels of BTEX 
compounds in the wastes' leachate are comparable to levels measured in 
the studies. Commenters argued, although the studies do not follow the 
Toxic Substances Control Act (TSCA) protocol developed by EPA to 
document biodegradation, the results should be viewed as comparable by 
EPA because they are presented in peer-reviewed journals.
    EPA conducted an evaluation of all submitted data and the 
documented anaerobic biodegradation studies of benzene suggest that in-
situ anaerobic biodegradation of benzene rates are strongly dependent 
on site-specific conditions (e.g., availability of chemicals to act as 
electron acceptors, availability of nutrients, temperature). The 
necessary conditions for anaerobic benzene biodegradation are poorly 
understood, and the absence of biodegradation can be caused by the 
presence of competing substrates, such as toluene, xylenes and 
ethylbenzene, as well as inadequate geochemical conditions and lack of 
proper electron acceptors (e.g., nitrate, sulfate, iron). Therefore, 
because of the lack of information to correlate site-specific 
controlling factors to biodegradation, the limited number of field 
data, and the field and laboratory evidence that benzene tends to be 
recalcitrant to anaerobic biodegradation, biodegradation of benzene was 
not considered directly in the groundwater analysis. However, EPA did 
complete preliminary modeling for the proposed rule that incorporated 
assumed rates into the analysis to see what impact this might have on 
receptor well concentrations (see the Petroleum Refining Listing 
Determination Background Document for Ground Water Pathway Analysis, 
1995, in the docket for details). When assuming degradations rate of 
0.00001 and 0.0001 per day, the well concentrations for all wastes 
examined decreased by approximately 2 percent and 44 percent, 
respectively. In addition, there may be a degradation ``lag time,'' 
which is the time period between the introduction of a constituent into 
the subsurface and the start of actual biodegradation. This time 
reflects the period subsurface microbial populations may need to 
acclimatize to the organic substrate before degradation may occur. 
Thus, if the lag time were 10 years, the decrease in the well 
concentration due to biodegradation assuming the higher decay rate of 
0.0001 day, would be lowered to only 22 percent. These results suggest 
that using a conservative degradation rate would not significantly 
alter the risk results for benzene. For example, even assuming 
biodegradation of benzene lowered the high-end risks for this 
constituent by about 50 percent, the risks would remain above 1E-5 for 
the hydrotreating/hydrorefining catalysts and crude oil storage tank 
sediment.
    EPA plans to study further the modeling of anaerobic biodegradation 
in the saturated zone of hazardous constituents from hazardous wastes 
and the physical conditions under which anaerobic degradation occurs 
where the Agency has developed sufficient data to permit such an 
analysis.

Location of Receptor Well

    The distance from the landfill to the receptor well is an important 
parameter in the groundwater model, because the projected 
concentrations of constituents at the well, and the corresponding 
risks, increase as the well location is moved closer. EPA received 
comments from six commenters on the value used by the Agency for the 
distance to the nearest well from a landfill. One of the commenters 
felt that EPA should have used a smaller distance, while the remaining 
commenters felt EPA's value was too small.
    One commenter believed EPA should have used the distance to the 
nearest well for off-site landfills that the Agency used in past 
listings, (i.e., 48 meters used in the dye and pigment proposed listing 
determination.) This value was less than half the value used for the 
petroleum listing determination. The commenter suggested that EPA 
perform the two parameter high-end analyses using the 48-meter distance 
to the receptor well.
    In response, EPA notes that in its Monte Carlo analysis the Agency 
used the full distribution of available receptor well distances, 
including wells at smaller distances. The risk results for wastes of 
concern were presented in the NODA, and were subsequently revised as 
described elsewhere to yield the final results in Table IV-2 (see 
Section IV.B, and the groundwater background document in the docket, 
Additional Groundwater Pathway Risk Analyses, 1998). Concerning the 
well distance used in the dyes and pigments rule, EPA notes that the 
Agency used essentially the same underlying well distance data in this 
rule as was used in the dyes and pigments proposed rule. The apparent 
high-end value used in this earlier rule (46 meters, not 48 meters 
cited by the commenter) represents the 95th percentile distance, and 
104 meters is the 90th percentile. However, EPA states in the dyes and 
pigments rule risk documentation (see page 21, Health Risk Assessment 
Background Document for the Dyes and Pigments Manufacturing Industry, 
November, 1994, in the docket for that rule) that the high-end well 
distance of 46 meters was chosen because this was the 90th percentile 
value. But as Table IV-2.7 in the dyes and pigments risk document 
shows, the 90th percentile value actually was 104 meters, nearly the 
same as the 102 meters high-end value used in the current petroleum 
rulemaking. Therefore, the use of 46 meters in the dyes and pigments 
rule as the 90th percentile distance was an oversight. Regardless, EPA 
believes that the 90th percentile value is more appropriate to use in 
the type of high-end sensitivity analysis performed for this 
rulemaking, and that the 95th percent value would be unreasonably 
conservative. EPA believes that setting two critical parameters to the 
90th percentile level is a reasonable approach to generate high-end 
risks that are above the 90th percentile, but still realistically on 
the distribution. Such an approach is consistent with EPA guidance (see 
Habicht, 1992). EPA's Monte Carlo analysis for the groundwater pathway 
supports this approach, i.e., the revised groundwater risks presented 
in Table IV-2 show that the high-end risks are above the 95th 
percentile risks estimated from the Monte Carlo analysis. Therefore, 
EPA believes its approach is appropriately conservative.
    The commenter also argued that the distance to the nearest well 
used in the groundwater assessment was inconsistent with the distance 
to the nearest receptor EPA used in the nongroundwater risk assessment. 
The commenter noted that the high-end value of 102 meters used for 
groundwater well distance is inconsistent with the high-end value of 75 
meters EPA used for the nearest residence in the nongroundwater risk 
assessment, and that this discrepancy between the distance values is 
never addressed or justified.
    EPA disagrees that the distances must be equivalent, because 
different pathways are represented in each assessment. Exposure from 
groundwater pathways occurs through potentially contaminated drinking 
water wells. Exposure from nongroundwater pathways occurs through 
multiple exposure routes, such as run-off and air releases from LTUs, 
and the point of exposure is considered the location of the residences 
nearest the LTU. Therefore, EPA used different data sets to estimate 
receptor distances for these pathways to account for well locations

[[Page 42142]]

for groundwater and residences for the nongroundwater pathways. For 
distances to residences in the nongroundwater pathways, EPA used 
information compiled for Treatment Storage and Disposal Facilities 
(National Survey of Hazardous Waste Generators and Treatment, Storage, 
Disposal, and Recycling Facilities in 1986: Hazardous Waste Management 
in RCRA TSDR Units, July 1991). These values were used instead of the 
ones used for groundwater because they reflect the distances to 
receptors being modeled, (i.e., residences at which people may be 
exposed to air releases or contaminated soils.) The distances to 
residences will not necessarily correspond to drinking water well 
distances.
    Four commenters felt that EPA should have used data from the 3007 
Questionnaire to calculate the distance to the nearest receptor well, 
which would result in a larger distance. Three of these commenters felt 
that EPA's decision to use values from the OSW Subtitle D Waste 
Management Facility Database was inconsistent with its earlier 
determination to base other information for its rulemaking on the 3007 
Questionnaire. They believed that the RCRA 3007 Questionnaire obtained 
sufficient data from respondents, and that data from this Questionnaire 
is more appropriate, since unlike the OSW data, the data are specific 
to refineries and residuals considered for this listing. Two commenters 
suggested that if EPA felt there was insufficient response to the 3007 
Questionnaire, EPA should have contacted non-respondents for further 
information.
    Because of the lack of completeness of the reported well distances 
in the 3007 Questionnaire, the Agency decided to use well distances 
from the Subtitle D Survey Database. The 3007 Questionnaire response 
was incomplete and inadequate. Of the 172 3007 Questionnaires returned, 
27 facilities reported the presence of nonhazardous on-site landfills 
used for the disposal of any waste in the survey in any year. Of these 
27, EPA found that only 15 reported the distance to the nearest 
drinking water well with any reliable documentation (e.g., well 
location maps, groundwater flow gradients, company survey of nearby 
wells). This limited data set is not surprising given the difficulty 
associated with seeking off-site information from the refineries that 
is not related to on-site operations. Furthermore, wells may be placed 
closer to the on-site landfills in the future. Therefore, EPA relied on 
distances obtained from the Office of Solid Waste (OSW) database as 
more representative of potential well locations. EPA notes that the 
3007 Questionnaire only provides well location information for 
evaluating on-site landfills, and even if used, would not have impacted 
the modeling results for off-site landfills. Because the risks from 
off-site landfills were higher or comparable to risks calculated for 
on-site landfills, any change in the results for on-site landfills is 
unlikely to alter any decisions to list wastes.
    Two commenters disapproved of EPA's methods for locating the 
receptor well in the contaminant plume for EPA's high-end and Monte 
Carlo analyses. The commenters argued that EPA should have assumed that 
the well is always located on the centerline of the contamination 
plume, in accordance with previous Agency listing determinations, and 
not have varied well locations across the width of the plume. The 
commenters submitted modeling results purporting to show that locating 
the receptor well on the centerline would increase risk such that a 
listing is required for most petroleum refinery wastes covered by the 
NODA.
    EPA defined the well location for modeling purposes by using the 
distance perpendicular to the plume centerline (Y coordinate) and the 
distance from the landfill to the well (X coordinate). The X distance 
to the well was discussed in the preceding comments. In the high-end 
analysis completed in the proposed rule, EPA fixed the Y coordinate of 
the receptor well location half-way between the plume centerline and 
the edge of the plume. However, the Agency has revised the two high-end 
parameter evaluations using a full sensitivity analysis for each waste, 
in which the Y-location of the well was either placed on the plume 
centerline (the high-end value) or at plume half-width (the median 
value). EPA also has performed Monte Carlo analyses in which the 
receptor well location was varied in such a way that the location 
reflected the nationwide distribution given in the USEPA database of 
Subtitle D landfills. The final revised Monte Carlo analyses used the 
available distance to well data (X coordinate) as noted earlier, and 
then randomly placed the well anywhere within the projected plume. Both 
of these approaches are more appropriate than what the commenter 
suggested, because placing the well on the plume centerline will tend 
to overestimate risks in affected wells by not considering other well 
locations. Therefore, EPA does not agree with the commenter, and 
believes that the approaches used by the Agency in the revised risk 
analysis fully considered well placement. In any case, EPA notes that 
the modeling submitted by the commenter shows that simply holding the 
well location on the centerline has little impact on the results. For 
example, the commenter's analyses that assumed the receptor well was 
always on the centerline yielded very minimal increases of zero to 
eleven percent for the four wastes they modeled in off-site landfills 
(see Appendix A in ``Analyses Using EPACMTP to Estimate Groundwater 
Pathway Risks from Disposal of Petroleum Refinery Wastes'' King 
Groundwater Science, in comment F-97-PRA-0005.A).
    Finally, in conducting the Monte Carlo analysis for the NODA, the 
Agency made a key assumption concerning well location, which was 
inconsistent with the assumption made for the deterministic analysis. 
In the high-end analysis, the downgradient wells of concern were 
assumed to be those within the plume of contamination from the 
landfill, as noted above. For the Monte Carlo analysis, all potential 
wells within a 180-degree arc downgradient from the landfill were 
included, thus including wells that would never be affected by 
contamination from the landfill. Each approach can provide valid 
assessments of risk distributions, but the two approaches describe 
risks for different populations of receptor wells. Upon further 
consideration of this issue, the Agency determined it is most 
interested in risks at well locations that could be affected by the 
landfill. Including wells that, because of their location, could not be 
affected no matter how toxic or mobile the waste constituents, provides 
EPA with little information about the waste on which EPA is making a 
decision. Thus, EPA has relied on the revised Monte Carlo analysis that 
includes only those well locations that were within the plume. The 
results of this change, along with the other revisions to waste volume 
and landfill area estimates that were described earlier, show that 
risks are higher than previously reported for different percentiles on 
the Monte Carlo distribution. For example, the Monte Carlo risk for 
landfills for crude oil tank sediment with the receptor well restricted 
to the plume was 1E-5, an increase over the Monte Carlo result of 7E-6 
when placing the well anywhere downgradient, and more comparable to the 
high-end results from the sensitivity analysis, 4E-5. With this 
adjustment in the Monte Carlo assumptions, the high-end and Monte Carlo 
results appear more consistent, and EPA believes that such an 
adjustment is logical.
    The differences between the two different approaches in locating 
receptor

[[Page 42143]]

wells in the Monte Carlo analysis is most obvious when comparing the 
constituent concentrations at the well calculated to be the 50th 
percentile values, otherwise known as the ``central tendency.'' By 
restricting the well location to the plume, the 50th percentile 
concentrations are over several orders of magnitude greater than those 
predicted when the well location is allowed to be outside the plume. 
(See Additional Groundwater Pathway Analysis, 1998, section 5.3.1, in 
the docket for this rule for more details.)
    EPA would like to use this occasion to make some observations about 
central tendency estimates. There is a common misperception that the 
central tendency estimate might be an ``unbiased'' or ``best'' estimate 
of risk. That could be extremely misleading, especially where it is 
difficult to distinguish variation and uncertainty. The 50th percentile 
estimates in the EPA groundwater Monte Carlo risk assessment used to 
support listing determinations under RCRA strive to be estimates of 
results for which half of the potentially exposed receptors face more 
risk and half face less risk in some group. However, that does not mean 
that such an estimate is a ``best estimate'' of a relevant result. As 
an example, consider if EPA did Monte Carlo estimates of groundwater 
risk at all wells in a 360 degree direction from a unit. In many cases 
(notably those with a fairly constant direction of groundwater flow 
relevant to any upgradient wells), well over half of the wells within 
any distance of the unit will be unaffected by releases from the unit 
and will have no risk. This would occur no matter what the toxicity or 
mobility of the hazardous constituent, and even though deterministic 
modeling might show with high certainty that wells in the direction of 
groundwater flow from the unit would have high risk. Clearly a central 
tendency estimate of ``no risk'' is not a ``best'' estimate of whether 
or not there will be groundwater risks, nor even a predictor of 
``mean'' risk or of the ``expected value'' risk. Instead, it gives an 
indication that there is considerable variation and that many or most 
wells will not be affected. That indication would not give EPA any 
confidence that a hazardous constituent would not have significant 
effect on the downgradient wells, nor any particularly useful 
information on the toxicity or mobility of the waste.

Monte Carlo Versus Deterministic Analysis

    Two commenters felt that the deterministic high-end risk assessment 
used by EPA does not allow EPA to determine what percentile of the risk 
distribution is represented by the high-end analysis. In response, EPA 
performed a Monte Carlo groundwater analysis to generate probability 
distributions for risk presented by each waste. These results were 
presented in the NODA, and revised Monte Carlo analyses, using the 
revised inputs for landfill area and lifetime, are given in Table IV-2.
    Several commenters recommended that the Monte Carlo analysis serve 
as the basis for a listing decision, due to the superior quality of the 
Monte Carlo-based risk estimates in comparison to the deterministic 
risk estimates (i.e., point estimates). They noted that in the NODA, 
EPA states that the Monte Carlo analysis ``confirms'' the risk findings 
(62 FR 16750-51); the commenters disagree with this approach and state 
the Monte Carlo results should be used as the primary determinant of 
individual risk. The commenters cite EPA guidance that has recognized 
the superior quality of Monte Carlo-based risk estimates compared to 
high-end approaches.
    In response, EPA notes that the Agency's ``Policy for Use of 
Probabilistic Analysis in Risk Assessment'' states that ``* * * such 
probabilistic analysis techniques as Monte Carlo analysis, given 
adequate supporting data and credible assumptions, can be viable 
statistical tools for analyzing variability and uncertainty in risk 
assessments.'' The policy also states that ``[i]t is not the intent of 
this policy to recommend that probabilistic analysis be conducted for 
all risk assessments supporting risk management decisions.'' In 
addition, as one of the conditions for using Monte Carlo analysis, the 
policy states that ``[c]alculations of exposures and risks using 
deterministic methods are to be reported if possible.'' Thus, the 
commenter's contention that information from Monte Carlo analysis is 
necessary to make a defensible listing determination is over broad and 
is inconsistent with Agency policy. The Agency's policy indicates that 
Monte Carlo analysis can be a useful tool for providing additional 
information on variability and uncertainty in certain situations (which 
is the way it was applied for this listing determination).
    Furthermore, it is important to note that the Agency's policies do 
not indicate that there is any particular point on a Monte Carlo 
distribution that should be the point at which the Agency regulates or 
does not regulate. The 1992 guidance (memorandum from the then Deputy 
Administrator F. Henry Habicht ``Guidance on Risk Characterization for 
Risk Managers and Risk Assessors'') states that ``[t]he `high end' of 
the risk distribution [generally the area of concern for risk managers] 
is conceptually above the 90th percentile of the actual (either 
measured or estimated) distribution. This conceptual range is not meant 
to precisely define the limits of this descriptor, but should be used 
by the assessor as a target range for characterizing `high-end risk'.'' 
Therefore, a high-end estimate that falls within the range (above the 
90th percentile but still realistically on the distribution) is a 
reasonable basis for a decision.

Exposure Duration

    One commenter questioned why the groundwater risk analysis used a 
constant exposure duration of 9 years for receptors, while the 
nongroundwater risk analysis for LTUs included this parameter in the 
sensitivity analysis and used a high-end value of 30 years. The 
commenter submitted modeling analysis that purported to show that 
including exposure duration as a high-end parameter in the sensitivity 
analysis would result in increased groundwater risks, and specifically 
cited increased risks for crude oil tank sediment and unleaded gasoline 
tank sediment.
    EPA does not agree that exposure duration is a particularly 
sensitive parameter in the analyses at issue. In the sensitivity 
analysis using exposure duration presented in the commenter's 
groundwater analysis, 30-year exposure risks appear to be erroneously 
calculated by simply multiplying the calculated 9-year exposure 
groundwater risk by a factor of 3.33, corresponding to the ratio of 30 
years/9 years. However, EPA's risks based on a 9-year exposure duration 
were calculated from the peak well concentrations averaged over a 9-
year period, using health-based numbers derived for a 9-year exposure 
period. The more accurate approach to model 30-year exposure would be 
to calculate maximum 30-year average groundwater concentrations from 
the modeling results, and then calculate the risk based on health-based 
numbers derived for a 30-year exposure period. Maximum 30-year average 
well concentrations may be smaller than 9-year average well 
concentrations depending on the peak concentration period. The 
commenter's apparent approach of simply scaling up risks based on a 9-
year exposure by a factor of 3.33 will likely overestimate the 
extrapolated risk for a 30-year exposure. EPA examined the effect of 
including exposure duration as an independent parameter in a 
sensitivity analysis for several wastes (HF alkylation sludge, unleaded 
gasoline tank sediment, and hydrorefining catalyst). The results of the 
analysis

[[Page 42144]]

showed that exposure duration was never a sensitive parameter, and 
including it in the sensitivity analysis had no impact on the selection 
of the two high-end parameters or the risk results for any of the 
wastes examined (see Section 3 of Additional Groundwater Pathway Risk 
Analyses, 1998). Therefore, EPA does not believe this factor greatly 
affects the risk calculations conducted for this rulemaking.

Potential for Release of Oil Phase From Wastes

    One commenter believed EPA inappropriately discounted the potential 
for migration of nonaqueous-phase liquids (NAPLs) arising from free oil 
in the wastes to the groundwater zone beneath the waste units. (Note 
that NAPLs that sink in water because they are more dense are called 
DNAPLs, while NAPLs that float because they are lighter than water are 
called LNAPLs). The commenter argued that EPA underestimated risk by 
evaluating management conditions unfavorable for NAPL release from 
landfills. The commenter also stated that EPA ignored the impact of 
this oil phase, or NAPL, on transport of waste constituents in the 
groundwater zone to the receptor well. EPA's evaluation in the proposed 
rule had concluded that the NAPL flow, if any, from these residuals 
will not reach the underlying aquifer and thus further modeling was not 
necessary. The commenter argues that EPA underestimated the fraction of 
oily liquid in the waste (suggesting a value of 80 percent), falsely 
assumed that the waste will be uniformly mixed with benign material 
that would not contribute to free oil, overestimated the capacity of 
the soil beneath the landfill (the unsaturated zone) to retain oil 
released from the landfill, and failed to consider the potential 
movement of the oil sideways in the subsurface.
    EPA does not agree with the commenter's assertions. First, EPA 
notes that the its analysis assumed a 27 percent free oil content in 
the waste for its initial calculations, based on data from the 3007 
Questionnaire. This is more realistic than the value of 80 percent 
cited by the commenter, because the 80 percent value resulted from an 
error in reporting. The 80 percent value represents the waste prior to 
deoiling, and does not reflect the oil content of wastes in landfills 
(see Supplemental Background Document-Listing Support Analysis, April 
1997 in the docket, App. A). The Agency used EPA's Composite Model for 
Oily Waste (EPACMOW), which accounts for both aqueous phase and non-
aqueous phase flow and transport, to estimate constituent transport. 
High-end parameters were chosen for sensitive parameters (landfill 
area, waste quantity, waste fraction, constituent concentration, and 
infiltration rate). Thus, even assuming the oil fraction is free to 
migrate, the model predicted no release of NAPL from the landfill, 
because there is not sufficient oil to saturate the material in the 
landfill beyond the 10 percent soil or waste saturation limit. Below 
this limit the oil will not migrate as a NAPL. If the oil does not 
escape the landfill, the NAPL cannot saturate the soil beneath the 
landfill, nor can NAPL-facilitated transport in the subsurface occur.
    EPA believes the commenter's concerns about NAPL or free-oil 
release from landfills are unwarranted for a more fundamental reason. 
As discussed elsewhere (see Sampling and Analysis of Refinery Wastes), 
the residuals of concern are not oily in the manner anticipated by the 
commenter. While the sampled residuals may contain oil, this 
observation is not equivalent with concluding, as the commenter does, 
that free oil is present in these residuals. The method used to 
estimate oil content in the samples, the Total Oil and Grease (TOG) 
method, will overestimate ``free'' oil because it uses a strong organic 
solvent to extract various organic material, including waxes, greases, 
and higher molecular weight oils that are not mobile. During EPA's 
observation and handling of crude oil storage tank sediment during 
sampling and laboratory analysis, a discrete free oil phase, was not 
observed. None of the samples analyzed via the TCLP in this 
investigation were found to have oily phases. In addition, as noted 
elsewhere, reported oil and grease content of landfilled wastes support 
EPA's conclusion that wastes with high oil content (whether free oil or 
not) are not typically land disposed. This result is consistent with 
EPA's belief that oil concentrations in a landfill will not reach the 
levels the commenter suggested, since refineries generally have 
economic incentives to recover free oil and minimize the amount of oil 
that is disposed in wastes.
    The commenter also submitted a report to document the plausibility 
of NAPL flow of contaminants from waste management areas (``Release of 
Dense Nonaqueous-Phase Liquids to Groundwater in Waste Disposal Areas: 
Part 1,'' March 1997). The commenter stated that the report showed four 
waste management facilities ``associated'' with the petroleum sector 
may have released nonaqueous phase liquids, or oil, into the 
groundwater. The commenter concluded that refinery wastes like those at 
issue in this rulemaking were codisposed with other wastes in the 
units, and may have caused the NAPL or oil release.
    EPA disagrees that the report cited by the commenter provides any 
information relevant to either the wastes under examination in this 
rule, or the type of landfill disposal at issue. EPA evaluated the 
report cited by the commenter and does not believe the information is 
particularly relevant to the listing decisions under consideration for 
several reasons. First, of the 26 sites identified in the report as 
having ``definite'' DNAPL contamination, 24 were Superfund sites listed 
on the National Priority List (NPL) for remediation. This limited 
number of NPL sites represented various industrial sites, many having a 
long history of many forms of waste mismanagement beyond landfilling 
(e.g., land spreading, land disposal of liquids, surface impoundments). 
As such, these sites can hardly be deemed to represent typical off-site 
landfills. Furthermore, the four facilities ``associated'' with the 
petroleum sector all operated from the late 1950s and most ceased 
operation by the early 1970s (one operated until 1981). Not 
surprisingly, the types of waste disposal that occurred at these four 
facilities do not resemble the typical disposal that occurs presently 
at landfills. The report shows (see Table A-3) that all of these 
facilities disposed of liquid wastes and sludges in surface 
impoundments; other liquid disposal practices included dumping into 
trenches and buried barrel mounds. In fact, from the information in the 
report it is not clear that any of the four sites had any unit 
resembling a solid waste landfill.
    In addition, the four sites accepted a variety of wastes, including 
chlorinated solvents and other organic wastes (see Table A-2 in the 
report). While two sites were reported to receive wastes from tanks 
(``wastes from tank cleaning'' and ``tank bottom sludge''), there is no 
evidence presented in the report to support the commenter's assertion 
that any wastes were similar to the wastes at issue in this rulemaking. 
In fact, given the apparent predominance of disposal of liquids at 
these two sites, and the lack of any mention of a landfill, it does not 
appear likely that the wastes cited resemble the wastes under 
evaluation in today's rule. As noted previously, the listing residuals 
of concern here did not exhibit free oil, and the available data 
indicate that residuals sent to landfills had low total oil content. 
Certainly the samples of tank sediments obtained by EPA were not 
liquids. Therefore, EPA

[[Page 42145]]

believes that this report does not demonstrate anything significant, 
beyond the general fact that some landfills in the past have contained 
wastes that may release NAPLs. However, it provides no useful 
information about the wastes under study and their potential for NAPL 
formation, in either on-site or off-site disposal. EPA does not believe 
the information is particularly relevant to the listing decisions under 
consideration.

Existing Groundwater Contamination

    One commenter stated that the subsurface under many refineries is 
grossly contaminated, and may affect the rulemaking in two important 
ways: (1) existing subsurface contamination can contribute 
significantly to groundwater risks at the modeled receptor well near 
refinery sites, thus EPA should include the cumulative risks in its 
assessments; and (2) the existing refinery groundwater contamination is 
often in the form of LNAPL (such phases float on top of the groundwater 
and typically contain lower molecular weight constituents, such as 
those found in gasoline) or other conditions that can facilitate the 
transport of organic contaminants at refinery sites, including but not 
limited to the PAHs in refinery wastes. The commenter noted that the 
rate and extent of LNAPL migration can depend upon site-specific 
circumstances, and often results in lower dilution and attenuation, and 
could result in higher concentrations at a receptor well. The commenter 
stated that while there is no nationwide survey of LNAPL occurrence at 
refinery sites, there is ample evidence that LNAPL contamination is 
frequent and severe, and EPA must take into account the hydrogeologic 
conditions known to the Agency that can affect the transport of 
hazardous constituents. However, the commenter did not offer any 
suggestions as to how to consider such ``facilitated transport'' in the 
groundwater assessment.
    EPA agrees that there are no doubt petroleum refineries at which 
significant LNAPL contamination from product spills exist; however the 
Agency does not believe this should have a significant impact on its 
listing decisions for several reasons. First, EPA's risk assessment is 
conservative in that it assesses incremental risk associated with 
targeted residuals using a relatively low 10-5 to 10-6 risk listing 
threshold, in part because of possible exposure to unknown pollutants. 
Furthermore, EPA cannot conclude that LNAPLs would be present at the 
precise sites where these wastes are likely to be disposed and 
potentially release constituents. As the commenter also noted, the rate 
and extent of NAPL migration can depend upon site-specific 
circumstances. The proper consideration of existing contamination would 
call for the full analysis of many other site-specific factors as well, 
some of which may tend to reduce constituent release from landfills, 
subsurface transport, and human exposure. Such factors would include 
the possible lack of potable groundwater near the site, and potential 
biodegradation at some sites, perhaps accelerated due to the prevalence 
of subsurface organisms that may exist in areas with contamination. 
Further, if LNAPL or other contamination exists, there may well be 
ongoing remediation, perhaps involving groundwater interception or 
pumping that would significantly alter or limit groundwater flow. The 
Agency believes that a site-specific assessment would be more 
appropriately carried out by State or Federal programs related to 
remediation of sites, and that such an approach would be quite 
difficult to follow in pursuit of an industry-wide listing 
determination.
    EPA also notes that it is not likely that aquifers so widely 
contaminated so as to have floating hydrocarbons would be a continuing 
source of drinking water. Such contamination should be easily detected 
and avoided, and would be unlikely to lead to the multiple-year 
transport and exposure scenario that is the basis for EPA's risk 
assessments. Furthermore, the level of benzene in likely sources of 
LNAPLs, gasoline (1.6 percent average, or 16,000 ppm), would dwarf any 
potential risk that might arise from the leachable levels of benzene in 
wastes under consideration in this rule, making any concept of 
cumulative risk difficult to apply in any meaningful way in a listing 
determination. (For comparison, the highest level of benzene in any 
TCLP sample of listing residual was 39 ppm for hydrotreating 
catalysts). As noted above, the commenter's approach also presumes a 
number of additional worst-case assumptions (regarding the presence of 
critically placed NAPLs) that cannot be considered in a vacuum, and 
would require the consideration of many other site-specific factors to 
fully evaluate.
    The Agency notes that the practical impact of considering LNAPLs 
and facilitated transport, even if this could be done, is not likely to 
be significant for most wastes of concern. EPA has decided to list the 
wastes with higher oil content (CSO tank sediment and crude oil tank 
sediment), as well as the spent catalysts. Thus, the wastes for which 
this comment is most relevant are being listed, leaving unleaded 
gasoline tank sediment and HF alkylation sludge as the only other 
wastes that showed any groundwater risk of concern to the commenter. 
EPA notes that the effective dilution and attenuation factors for 
benzene resulting from the modeling (DAF; calculated by dividing the 
TCLP input at the point of release from the landfill by the projected 
concentration at the receptor well) for both of these wastes were on 
the order of 2 to 4 (see Additional Groundwater Pathway Analysis, 
1998). These low DAFs approach the theoretical limit of one, which mean 
that benzene released from the landfill is estimated to reach the 
receptor well at concentrations that approach the levels in leachate 
released. Therefore, it is highly unlikely that EPA's assessment 
significantly understates groundwater risks for these wastes, and any 
further considerations in the modeling (such as ``facilitated 
transport'' due to existing contamination) are unlikely to 
significantly alter the modeling results.
    Unlike the modeling for benzene, which is relatively mobile in 
groundwater, the limited modeling for PAHs detected in TCLP samples 
indicates that contaminated subsurfaces may have the potential to 
affect the migration of PAHs in groundwater. PAHs are relatively 
insoluble in water and are not expected to migrate easily via aqueous 
leaching and transport, and the high-end analysis for the PAH 
benz(a)anthracene showed DAFs of 15-64 (see Additional Groundwater 
Pathway Analysis, 1998). As the commenter noted, the presence of 
existing contamination such as NAPLs in the subsurface may facilitate 
migration. Some oily wastes contained potentially significant levels of 
PAHs (CSO sediment, crude oil storage tank sediment), and while TCLP 
results showed no detectable leaching, the detection limits in these 
samples were above health-based levels. It is difficult to assess 
potential groundwater risks from PAHs with complete certainty because 
undetected but potentially significant levels might possibly be in the 
TCLP leachate. PAHs could theoretically present some risk if they 
leached at their aqueous solubility levels, which in many cases are 
below detection limits. For example, the water solubility of 
benz(a)anthracene (0.013 mg/L) is 32 times the health-based level (4E-4 
mg/L at the 1E-6 risk level), and this level is very close to the 
method detection limit (about 0.010 mg/L). While EPA cannot quantify 
any risks from TCLP samples in which PAHs

[[Page 42146]]

were not detected, the presence of these carcinogenic PAHs in the waste 
present some potential for additional risk, especially if transport is 
facilitated by existing contamination. Therefore, while EPA is not 
using the presence of carcinogenic PAHs as the sole or overriding 
factor in listing any waste (except for CSO sediment which clearly 
exhibited high risks from nongroundwater pathways due to PAHs), the 
presence or absence of carcinogenic PAHs was a contributing factor EPA 
considered in decisions to list or not list certain wastes (i.e., crude 
oil storage tank sediment, unleaded gasoline tank sediment, and HF 
alkylation sludge. However, EPA would not list solely on the 
undetermined potential for groundwater risks from PAHs given their 
relative insolubility, and because facilitated transport by LNAPLs is a 
complex hypothesis that EPA did not find likely for these particular 
wastes.
7. Specific Nongroundwater Modeling Issues

Uncertainty Analyses in Indirect Exposure Assessment

    For both the proposed rule and the NODA, estimates of non-
groundwater pathway risks were derived using a deterministic risk 
assessment method, which produces point estimates of risk using single 
values for input parameters. In this method, input parameters are 
varied between the central tendency value (50th percentile) and the 
high-end (90th percentile) values. The point estimate in which all 
variables are set at central tendency is assumed to be the central 
tendency risk estimate, and the highest risk estimate for any 
combination of double high-end variables (with all other variables set 
at central tendency) is assumed to be the high-end estimate of risk. 
The high-end risk estimate is presumed by the Agency to be a plausible 
estimate of individual risk for those persons at the upper end of the 
risk distribution. The intent of these descriptors is to convey 
estimates of exposure in the upper end of the distribution (i.e., above 
the 90th percentile), while avoiding estimates that are beyond the true 
distribution. The high-end risk as estimated in the proposed rule and 
NODA is the highest risk estimate for any combination of double high-
end variables defined as those two variables modeled that, when set at 
90th percentile values, pose the highest risk of all possible 
combinations of any two variables. Using this methodology, the point 
estimate in which all variables are set at central tendency (50th 
percentile) is assumed to be the central tendency risk estimate, and 
the highest risk estimate for any combination of double high-end 
variables is assumed to be the high-end estimate of risk (above the 
90th percentile; see Agency guidance in the Habicht memo, 1992).
    The Agency requested comments on how best to factor uncertainty 
into Agency listing determinations based on the non-groundwater risk 
assessment. These risk assessments are so-called ``indirect'' exposure 
assessments, and are discussed in the proposed rule preamble at 60 FR 
57762. Indirect exposure assessments are those in which the receptors 
(in this case nearby residents, home gardeners, subsistence farmers and 
subsistence fishers) are exposed to contaminants in the waste after 
these contaminants have been transported from the waste management area 
and have entered another environmental media (in this case soil and 
various food products) at the receptor site. This issue is important 
for this rule because the potential exposure pathways of concern arose 
from releases of soils through erosion (run-off) or wind-blown air 
emissions from LTUs onto adjacent areas.
    Of particular concern to the Agency in the proposal was the issue 
of whether it is accurate to assume that greater uncertainty generally 
results in a more conservative risk assessment. One commenter noted 
that because the uncertainty in indirect exposure assessment can lead 
to a substantial overestimation of risks, failure to consider 
uncertainty can result in listing decisions for refining process 
residuals that do not actually pose a significant risk. The commenter 
suggested that EPA could account for uncertainty in indirect exposure 
assessment through a quantitative probabilistic uncertainty analysis, 
or to list those wastes associated with substantial uncertainty only if 
the estimated risks are at the high-end of the risk range.
    Other commenters questioned the use of individual assumptions or 
input parameters in the nongroundwater risk assessment for LTUs. 
Commenters specifically noted that EPA should include a quantitative 
analysis of the following sources of uncertainty in the risk estimates 
for residuals proposed for listing: biotransfer factors, food 
consumption rates, biodegradation, land application rates, and physical 
transport processes.
    The Agency agrees that an uncertainty analysis is desirable and 
conducted an uncertainty and variability analysis in support of the 
final nongroundwater risk assessment. The Agency addressed specific 
comments regarding use of individual parameters (e.g., biodegradation 
rates) by including those parameters in the uncertainty analysis. A 
detailed description of the uncertainty analysis is presented in the 
document titled Uncertainty Analysis: Nongroundwater Pathway Risk 
Assessment; Petroleum Refining Waste Listing Determination available in 
the docket for today's rule. This document identifies the source of 
uncertainty or variability noted by commenters in each step of the 
analysis and describes the method of quantifying or mitigating that 
uncertainty/variability. When data distributions were available, 
variable parameters were included in a Monte Carlo simulation to 
provide a quantitative measure. If little or no data were available, a 
qualitative discussion of the source and effect of the uncertainty is 
provided. Key variables included in the uncertainty analysis include: 
constituent concentrations, biodegradation rates, distance to receptor, 
soil erosion parameters, bioaccumulation factors and bioaccumulation 
rates, and ingestion and consumption rates. The uncertainty associated 
with the generalized site assumptions of LTU area, waste quantity, and 
geographic location used in the deterministic analysis was addressed 
through the use of site-specific data where available.
    The nongroundwater assessment uncertainty analysis covers three 
waste streams: CSO sediment, crude oil storage tank sediment, and off-
specification products and fines. These were the only wastes with 
moderate to high levels of carcinogenic PAHs, and because PAHs were the 
constituents of concern for LTU risks, the risks for other wastes in 
this scenario were negligible (see 62 FR at 16753). EPA proposed CSO 
sediment for listing on the basis of the nongroundwater deterministic 
(high-end) analysis, which showed significant risk from PAHs. Crude oil 
storage tank sediment, which contains similar constituents in lower 
concentrations, showed risk levels from land treatment below EPA's 
range of concern. Off-specification products and fines also have 
similar constituents present in lower concentrations, but were not 
originally modeled as managed in LTUs for the proposal because the 
volumes managed this way were relatively small. However, off-
specification product and fines were modeled as part of the LTU 
analysis conducted for the NODA to respond to comments on potential 
risks arising from codisposal. (See Section V.C.6 for a full discussion 
of the decision on off-specification products and fines).

[[Page 42147]]

    The probabilistic uncertainty analysis was performed on a 
constituent specific basis, thus comparisons between the Monte Carlo 
and the high-end results must be made for a specific constituent to be 
meaningful. For example, for clarified slurry oil sediment managed on-
site, the high-end risk analysis estimated a risk of 5E-5 to the 
subsistence farmer from dibenz(a,h)anthracene via oral ingestion 
pathways. The uncertainty analysis for on-site management of clarified 
slurry oil sediment indicated a 90th percentile risk to the farmer from 
dibenz(a,h)anthracene via oral ingestion of 5E-5 for the site modeled 
(Anacortes, WA). For CSO managed off-site, the high-end ingestion 
pathway risk to the farmer from dibenz(a,h)anthracene was estimated to 
be 2E-6. Based on the probabilistic analysis, the corresponding 90th 
percentile risk for this waste stream was 3E-6 and 1E-5, respectively, 
for the two off-site LTUs modeled (Robstown, TX and White Castle, LA). 
For both crude oil storage tank sediment and off-specification products 
and fines, the uncertainty analysis indicates that risks are below 1E-5 
at the 90th and 95th percentiles for all exposure scenarios associated 
with on-and off-site management of these waste streams in LTUs, 
consistent with the high-end deterministic results.
    The uncertainty analysis confirms that the high-end risk results 
presented in the NODA are plausible estimates of risk for individuals 
at the upper end of the risk distribution. In the high-end analysis 
presented in the NODA, the total carcinogenic risk (i.e., the combined 
risk from all of the hazardous constituents) for this waste was 2E-4, a 
level well above EPA's benchmark level of concern (1E-5). For the on-
site CSO scenario, the uncertainty analysis indicates risks of 1E-5 
from individual constituents at the 90th percentile of the risk 
distribution. Thus, the uncertainty analysis indicates that on-site 
high-end risks for CSO from individual hazardous constituents clearly 
do not represent risks that are outside of the true distribution. 
Rather, the probabilistic analysis indicates that high-end risks for 
individual hazardous constituents in some cases represent exposure 
below the 90th percentile of the risk distribution.
    The total carcinogenic high-end risk for CSO for off-site units was 
2E-5. For this waste management scenario, the uncertainty analysis 
indicates risks of 1E-5 from a single constituent at well below the 
90th percentile. The off-site probabilistic analysis also suggests that 
the high-end risks may be somewhat below the 90th percentile for this 
scenario.
    Based on the results of the uncertainty analysis, therefore, the 
deterministic analysis certainly does not appear to overestimate risks 
from CSO. In any case, the decision to list CSO sediment is clearly 
supported by the uncertainty analysis. The Monte Carlo risk results 
below 1E-5 under all conditions for crude oil storage tank sediment and 
off-specification product and fines also confirms the decision not to 
list these wastes based on nongroundwater risks (note that EPA has 
decided to list crude oil storage tank sediment based on groundwater 
risks from landfill disposal).

Run-on/Run-off Controls

    EPA received numerous comments regarding the use of run-on/run-off 
controls for LTUs, which indicated that there was some confusion about 
EPA's assumptions regarding these controls in the risk assessment. The 
proposed listing determinations (as well as today's final decision) 
assumed no controls for the high-end analysis, and 50 percent effective 
controls for the central tendency analyses. Commenters challenged these 
assumptions as outlined below.
    Two commenters argue that there is no legal or factual foundation 
for the Agency's assumption that any plausible mismanagement involving 
land treatment now or in the future will occur at a facility with run-
off controls, much less with controls achieving 50 percent efficiency. 
Conversely, seven commenters state that even where there are no 
Subtitle C or mandatory state Subtitle D regulatory requirements for 
these controls, numerous other factors are motivating their use, as 
evidenced by the fact that most facilities use them.
    EPA conservatively assumed that no run-off controls were present in 
its high-end analysis of risk to individuals residing near land 
treatment facilities because the presence and effectiveness of such 
controls could not be verified. The central tendency scenario, however, 
assumed that controls were in place that were 50 percent effective. 
After consideration of all comments and the available data, EPA did not 
change these assumptions in subsequent risk assessments for the NODA. 
The bases for these assumptions were responses to the 3007 
Questionnaire and a survey of State programs. In the 3007 
Questionnaire, refineries were asked to characterize whether run-on or 
run-off controls were in place at LTUs used in 1992. Based on this 
information, all of the 18 facilities with LTUs reported some level of 
controls. As part of the revised risks analysis for LTUs presented in 
the NODA, EPA determined all but 6 LTUs are permitted Subtitle C units, 
and thus required to have run-on/run-off controls (see 40 CFR 264.273). 
For the nonhazardous units, it was not possible to quantify the 
effectiveness of the controls due to the very general nature of the 
questions and responses.
    EPA's survey of State programs showed that, while some states have 
established minimum standards for Subtitle D units, many states do not 
have regulations on run-on/run-off controls (see Communications with 
State Authorities on Requirements for Land treatment Units, EPA, 1995; 
Docket # F-95-PRLP-S0019). The effectiveness of run-off control is 
dependant on many factors (e.g., level of engineering design, operation 
and maintenance practices, regulatory oversight and minimum standards, 
weather conditions), and the effectiveness may vary because of the lack 
of Federal nonhazardous LTU standards. As a result, EPA assumed only 
partial effectiveness, 50 percent controls, for the central tendency 
analysis, and no controls for the high-end analysis. EPA does not have 
data available that would allow for more precise quantification of 
effectiveness. The Listing Program's mandate to consider potential 
mismanagement scenarios clearly does not rely on assumption of the best 
controls, but rather must more closely evaluate the weakest plausible 
management scenarios. In the case of LTUs, this includes the potential 
for no or minimal run-on or run-off controls in many states, reflecting 
the lack of national minimum standards. (EPA notes that, in the revised 
NODA analysis, the Agency did not use LTU areas for hazardous waste 
units in its risk assessment, because these units are assumed to have 
effective controls in place. This information would not be applicable 
to estimating risks for nonhazardous LTUs).
    Furthermore, EPA notes that the risks arising from soil run-off 
have limited impact on the Agency's final listing decisions based on 
the outcome of the risk for the nongroundwater pathways. This is 
because EPA has discovered that, due to an error in the air dispersion 
modeling conducted for the proposal, the risk attributable to the air 
pathway has increased and is now the same order of magnitude as the 
risk due to soil erosion. (The error was in converting units from 
g/m\2\ to g/m\2\). The unit conversion correction makes the 
risk due to air deposition from windblown soil from the LTU comparable 
to the risk

[[Page 42148]]

attributed to soil erosion. For example, for on-site LTU risk for CSO 
sediment, the total carcinogenic risk due to soil transport is 1E-4. 
The risk due to air deposition is approximately 7E-5, and the risk from 
soil run-off is about 3E-5 (see the NODA response to comment document 
for a more detailed discussion). Thus, soil erosion and run-off control 
assumptions are not as critical for the listing determination, because 
even in the absence of exposure through run-off, the risks for this 
waste are well above 1E-5 and merit listing. The relative contributions 
to the media concentrations of contaminants from air and erosion were 
investigated in the uncertainty analysis conducted in support of this 
listing determination.

Soil Transport

    EPA received numerous comments to both the proposed rule and the 
NODA questioning the methodology used to estimate soil run-off and 
transport from an LTU to surrounding fields and water bodies. 
Commenters to the proposal stated that transport of soil from the land 
treatment area to the receptors was not physically possible as modeled 
by EPA's use of the Universal Soil Loss Equation (USLE).
    The USLE is an empirical erosion model originally designed to 
estimate average soil erosion losses to waterbodies from an 
agricultural field having uniform slope, soil type, vegetative cover, 
and erosion control practices. In the proposed risk assessment, the 
USLE was used to estimate the mass of soil lost per year per unit area 
from a LTU and deposited onto an adjacent receptor site. EPA estimated 
the percentage of the eroded soil that reached the receptor site using 
a fixed sediment delivery ratio. The Agency estimated the amount of 
soil eroded from the LTU and deposited on each receptor site 
(agricultural field, residential lot, home garden) independently of 
soil eroded and deposited into the nearby waterbody.
    In response to comments on the proposed rule, EPA substantially 
revised its approach to estimating soil concentrations. This approach 
is presented in the NODA. Revisions were made to more accurately model 
an integrated soil erosion setting that includes the field, a buffer 
zone and the water body. The revised method for estimating soil erosion 
incorporates mass balance assumptions within the field to stream 
setting, and places the receptor field between the landfill and the 
waterbody. The model estimates rate of soil delivery to the nearest 
waterbody and assumes that the soil eroded from the source that does 
not reach the stream is deposited evenly over the subbasin, including 
the garden.
    Commenters on the NODA regarding EPA's use of USLE to estimate soil 
erosion centered on the assertion that run-off after leaving the land 
treatment area does not flow uniformly across the landscape, but will 
instead flow in a ``channel'' moving downstream toward the outlet of 
the basin or watershed. A number of commenters also argued that EPA's 
assumption of receptor locations relative to LTUs is unreasonable. They 
noted that EPA assumed that residences are directly downgradient of 
LTUs and that there are no obstructions to flow, when in fact the 
existence of a ditch, fence, wooded area, road, building, or swale 
between the landfarm and a garden eliminates this pathway of exposure. 
Commenters contended that the run-off cannot reach the gardens, farms 
and adult residents without unrealistic assumptions regarding location 
of receptors. These commenters argued that EPA failed to adequately 
respond in the NODA to proposed rule comments that the run-off from an 
LTU cannot physically reach the home gardens as assumed and that 
therefore the revisions presented in the NODA are inadequate.
    EPA's revised method for estimating soil erosion assumes that the 
sediment delivery ratio is constant across the area between the LTU and 
the waterbody (i.e., it does not assume channeling), and that receptor 
sites are assumed to be downgradient from the source and within the 
same defined subbasin as the LTU. EPA believes that these assumptions 
are reasonable in order to estimate risk that might be expected to 
occur at petroleum refining locations. In the absence of specific data, 
EPA believes that its assumptions are reasonable and appropriately 
conservative, because residential locations may change over time. In 
addition, EPA notes that to properly consider channeling in soil 
erosion would require extremely detailed site descriptions of the 
topography and local conditions, and sufficiently detailed site 
descriptions are not available. In the absence of such detailed data, 
EPA used simplifying assumptions to estimate soil erosion that may 
occur over a wide range of possible scenarios. Furthermore, while the 
commenters disputed the modeling approach used by the Agency, they did 
not provide any alternative model that could be used with the 
information available.
    For listing determinations, EPA wants to ensure that its risk 
estimates are conservative, and do not underestimate risks from 
releases from LTUs containing these wastes. As noted extensively 
elsewhere in this Section, other commenters have raised reasons why 
EPA's modeling of LTUs may underestimate risks (e.g., existing 
contamination around refineries, codisposal with other wastes). EPA 
believes that its overall modeling approach for LTUs is an appropriate 
middle ground and reflects risks that may arise from such units. The 
models used by EPA to develop this rule are exceedingly complex. It 
would not be practicable, and likely impossible, to develop models that 
would account for all possible sources of site-specific variability. 
Accordingly, EPA has used reasonable, simplifying assumptions to 
estimate risks.
    As described above in the discussion on run-on/run-off controls, 
EPA inadvertently made an error in the modeling for the proposed rule 
in unit conversion, which created an underestimation of risk due to air 
deposition. This change was described in the nongroundwater risk 
background document for the NODA. Because the unit conversion 
correction makes the risk due to air deposition from windblown soil the 
same order of magnitude as the risk attributed to soil erosion, USLE 
modeling assumptions do not provide the sole basis for the listing 
determination.
    Specific comments regarding the individual parameters and 
assumptions used in EPA's USLE calculations (e.g., steepness of slope, 
soil delivery rate, meteorologic and soil data) are addressed in detail 
in the response to comment documents for the proposal and the NODA. In 
addition, the modeling conducted as part of the uncertainty and 
variability analysis for LTUs included site-specific meteorologic data, 
soil data, USLE parameter values, and the distance between the LTU and 
the home gardener receptor. This analysis has shown that the listing 
decision is not altered by the use of site-specific data for some of 
the parameters questioned, or by variation in the receptor location.

Bioavailability and Bioaccumulation

    EPA received a number of comments on the manner in which biological 
processes such as bio-uptake, biotransformation, and bioaccumulation 
were considered in the non-groundwater risk assessment. One commenter 
states that EPA should have, but did not, consider the potential health 
effects to subsistence farmers and fishers due to bioaccumulation of 
PAHs. The commenter contends that EPA simply ignored this exposure 
route for these receptors due to the ``high uncertainty'' associated 
with fish and

[[Page 42149]]

plant-to-animal bioconcentration factors for the PAHs of concern in 
this rulemaking. The commenter believes that EPA should consider the 
information qualitatively, and/or present a range of results based upon 
possible bioconcentration factors. EPA responds that the Agency 
appropriately considered bioaccumulation of PAHs in these receptors as 
discussed below. A more detailed response to this issue is found in the 
uncertainty and variability analysis conducted in support of the risk 
assessment for this rule.
    The subsistence farmer scenarios were evaluated initially for the 
proposed rule using beef and milk biotransfer factors for PAHs that 
were estimated based on the octanol/water partition coefficient 
(KOW). KOW is a measure of the affinity a 
chemical has for a nonaqueous, organic environment (octanol), versus 
its tendency to stay in water, and is commonly used to assess the 
absorption rate of a given compound from the environment into 
organisms. Beef and dairy biotransfer factors are used to estimate the 
transfer of constituents from the diet of cattle into meat and milk 
products consumed by humans. KOW was initially used as a 
surrogate for biotransfer because measured data on the biotransfer of 
PAHs from plants to cattle or other ruminants are currently 
unavailable. However, in the NODA, EPA decided not to use these 
estimates in the risk assessment because the Agency believes that use 
of KOW greatly overestimates biotransfer for constituents 
with large KOWs. This includes the PAHs of concern in 
petroleum waste streams.
    Estimates of biotransfer based upon KOW only consider 
transfer of the constituent from the concentration in the diet into the 
concentration in the lipid storage in the animal. These estimates do 
not consider metabolic pathways for any constituents. In fact, PAH 
compounds with large KOWs are readily metabolized by the 
mixed function oxidase metabolic pathway in mammals to water-soluble 
substances, which are then excreted. In other words, these PAHs tend 
not to bioaccumulate in animal or human tissue, but rather to be 
metabolized and excreted.
    To summarize, because it is not possible to estimate PAH 
biotransfer factors without at least one measured value for any PAH 
compound, the Agency did not quantitatively model risks from 
bioaccumulation of PAHs for the farmer and child of farmer scenarios. 
Rather, based on knowledge of how PAHs with large KOWs are 
metabolized in mammals, the Agency has concluded that risk attributable 
to the beef and dairy pathway are likely to be less than the risk 
attributable to other ingestion pathways for these scenarios. A more 
detailed discussion of the metabolic pathways for these constituents is 
provided in Section 4.5 of the uncertainty and variability analysis.
    Subsistence fisher scenarios were evaluated using measured 
bioaccumulation and bioconcentration factors (BAFs and BCFs) where 
available. BAFs generally reflect the transfer of contaminant from the 
environment to the fish from food sources. BCFs represent the transfer 
from the dissolved phase to the fish tissue BCF. Because measured BAFs 
are usually not available, BCFs are most often used. For those 
constituents for which neither measured BAFs nor BCFs were available, 
EPA assumed that BAFs did not exceed 1000 liters per kilogram of fish 
body weight (L/kg). This assumption is based on the data presented in 
Derivation of Proposed Human Health and Wildlife Bioaccumulation 
Factors for the Great Lakes Initiative (U.S. EPA, 1993).
    While there are insufficient data to define the distributions and 
correlations needed for a reliable Monte Carlo analysis of 
bioaccumulation of PAHs in fish, EPA did conduct a quantitative 
uncertainty analysis after the NODA for BAFs using interval analysis. 
This is an appropriate statistical method for estimating missing values 
in a distribution even when data are limited as is the case for BAFs 
for PAH.
    This analysis indicates that although there is not enough 
information to define the distribution and correlations needed for a 
reliable Monte Carlo analysis, the estimation of 1,000 l/kg is 
appropriate and within the range of uncertainty predicted for PAH 
compounds. A more detailed discussion of EPA's assessment of 
bioaccumulation of PAHs in fish is provided in Section 4.5 of the 
uncertainty analysis for the nongroundwater pathway risk assessment, as 
well as in the response to comment document for this rule (see Section 
M of the response to comment document for the proposed rule).
    One commenter questioned the air-to-plant biotransfer factors (Bv) 
used by EPA in the analysis conducted for the proposed rule. The 
commenter stated that EPA's calculations of Bv contain errors, and 
claimed that EPA did not adequately explain or provide the basis for 
its estimate of Bv values. In comments on the NODA, the same commenter 
argued EPA continued to overestimate air-to-plant transfer.
    EPA responds that the errors noted by the commenter were corrected 
in the reanalysis presented in the NODA. The basis for EPA's estimate 
of Bv values is as follows. Measured values for air-to-plant 
biotransfer factors are available for many PAH constituents. Where 
available, EPA used measured values. The remaining Bvs are estimated 
from the KOW (using the Bacci equation). As previously 
noted, KOW tends to overestimate the bioaccumulation of 
constituents with very large KOWs such as PAHs. EPA 
compensated for this overestimate by reducing the calculated Bv by a 
factor of 40. This approach was first presented in the 1993 Addendum to 
Methodology for Assessing Health Risks Associated with Indirect 
Exposure to Combustor Emissions (EPA document number EPA/600/AP-93/
003).
    One commenter argues that the assumption of 100 percent 
bioavailability of deposited constituents is overly conservative 
because many constituents, particularly PAHs, bond tightly to soils and 
are unlikely to be available to an organism even if the soil is 
ingested.
    In response, EPA contends that the 100 percent bioavailability 
represents a reasonably conservative estimate of risk that will result 
in a rule protective of health and the environment. The bioavailability 
of PAHs from ingested soil depends on several environmental and 
physiologic factors. The process by which ingested soil-bound PAHs are 
made more or less bioavailable in the digestive tract and the effect of 
soil characteristics are not well understood; study results are 
conflicting. A recent study on the oral bioavailability of PAHs from 
soil, reported that the oral absorption of PAHs in rats, hamsters, or 
humans from diet or oil is approximately 92 percent. Another recent 
abstract presented data for the bioavailability of the PAH 
benzo(a)pyrene (BaP) from soil in terms of fraction of the BaP in soil 
that is absorbed relative to the BaP ingested. Based on that report, 
the fraction of BaP absorbed varied from 0.07 to 0.75. (A more detailed 
discussion of this issue is provided in Section III.F of the response 
to comment document for the proposal in the docket). Due to the 
uncertainty regarding the bioavailability of PAHs in soil, the Agency 
believes it is appropriate to assume PAHs to be 100 percent 
bioavailable in order to be fully protective of human health.

Exposure Factors

    Three commenters provided comments on risk to home gardeners from 
consumption of contaminated produce. In comments to the proposed rule, 
one commenter argued that EPA's estimate of risks from root vegetable 
consumption are overestimated by two orders of magnitude. EPA responds 
that,

[[Page 42150]]

based on this comment, the ingestion rates used for vegetables consumed 
by home gardeners and subsistence farmers were corrected and the 
corrected rates were used in the revised risk assessment presented in 
the NODA.
    Another commenter states that the percentage of the population 
assumed to have gardens is overestimated because EPA did not account 
for the fact different rates of produce consumption by the home 
gardener correspond to different types of gardens. The commenter 
contends specifically that EPA's assessment of risk to the home 
gardener from CSO sediment is significantly overestimated due to 
overestimation of the amount of produce consumed. The commenter states 
that EPA should have used data from the National Gardening 
Association's 1994-95 survey for assumptions regarding percentage of 
the population with vegetable and fruit gardens and fruit and vegetable 
ingestion rates.
    In response, EPA notes that the exposure factors (e.g., patterns of 
fruits and vegetables consumption by home gardeners) used in the 
analysis presented in the NODA were obtained from the 1997 Exposure 
Factors Handbook, which provides EPA's most recent data on the various 
factors used in assessing exposure. Furthermore, EPA addressed the 
variability in consumption rates within different subpopulations as a 
component of the uncertainty and variability analysis performed after 
the NODA. As previously noted, results from the uncertainty and 
variability analysis support the findings of the revised high-end risk 
analysis presented in the NODA.
    Several commenters contend that EPA overestimated soil ingestion. 
One commenter asserts that EPA did not account for the fact that 
individuals ingest soil in proportion to the time spent at each 
location (i.e., away from home, indoors at home, outdoors at home). EPA 
responds that variability in soil ingestion rates has also been 
addressed in the uncertainty and variability analysis conducted in 
support of the risk assessment for this rule. The uncertainty analysis 
used data on soil ingestion rates provided in the 1997 Exposure Factors 
Handbook.

Background Contamination

    One commenter notes that EPA's modeling assumes no background or 
other contaminant exposure to nearby receptors, an unjustifiable 
assumption given other waste management practices occurring at these 
facilities, the pre-existing contamination at many refineries, and the 
routine and accidental releases associated with refinery operations.
    As EPA noted elsewhere in today's notice when discussing existing 
groundwater contamination, the Agency does not believe this is 
appropriate to consider for this listing for several reasons. First, 
EPA does not have the type of specific information on off-site 
contamination that would be required, nor did the commenter provide 
any. Furthermore, without extensive site-specific data, EPA cannot 
conclude that existing soil contamination would occur at the same off-
site locations that might be impacted by releases from LTUs containing 
the wastes under study. The proper consideration of existing 
contamination would call for the full analysis of many other site-
specific factors, some of which may reduce constituent release, 
transport, bioaccumulation, and exposure. Such factors include specific 
LTU design, the direction of any slope from the unit, the existence of 
downgradient residential receptors, and corrective action requirements 
that may lead to clean up of any release.

Fate, Transport, and Toxicity of PAHs

    Commenters to the proposal pointed out that EPA failed to consider 
the biodegradation of PAHs in LTUs and at off-site receptor locations, 
thus overstating risks from PAHs in soils. One commenter noted that 
failure to consider biodegradation of the PAHs, 7,12-
dimethylbenz(a)anthracene ((7-12-DMBA) and 3-methylcholanthrene (3-MC) 
in the risk analysis for CSO sediment resulted in the overestimation of 
risks, because these two compounds have high cancer slope factors. 
While biodegradation of PAHs within LTUs was considered in the analysis 
for the proposed listing, biodegradation that may occur during 
transport of soil from the LTU to the receptor location was not 
considered in that assessment.
    EPA agrees that biodegradation during transport may be a 
significant removal process for PAHs and should be considered in 
analysis of PAH fate and transport. Therefore, in response to this 
comment, the nongroundwater risk analysis conducted for the NODA was 
expanded to include biodegradation of PAHs (including 7,12-DMBA and 3-
MC) at the receptor location for the waste streams of concern. Detailed 
results of this analysis are provided in the revised risk assessment 
technical background document in the docket for the NODA. The 
reanalysis presented in the NODA did not significantly change the risk 
estimates for these waste streams; however, because some of the PAHs 
have relatively long half-lives (e.g., 3-methyl cholanthrene's half-
life is reported to be from 1.67 to 3.84 years) so they are unlikely to 
biodegrade significantly prior to reaching the receptor.
    Contrary to the commenter's prediction, consideration of 
biodegradation at the receptor did not result in reduction of risk 
estimated for CSO sediment. For example, based on the analysis for the 
proposed rule, the high-end cancer risk for the home gardener scenario 
from CSO sediment managed on-site was estimated to be 9E-5. Based on 
the NODA analysis, high-end risks for this scenario were estimated to 
be 1E-4.
    For the analysis conducted for the NODA, EPA used only the most 
conservative value for biodegradation rates in order to assure that 
biodegradation is not overestimated when conditions and locations are 
not ideal for biodegradation. However, biodegradation rates were varied 
as part of EPA's analysis of the uncertainty and variability associated 
with non-groundwater risk assessment presented in the NODA. As 
discussed above, the results of the uncertainty/variability analysis 
support the findings of the revised high-end risk analysis presented in 
the NODA.

C. Residual-Specific Comments

    The most important risk and modeling issues raised by commenters 
that were general in nature, or were raised repeatedly for various 
wastes, are addressed in the preceding section. Below EPA discusses 
specific comments important for individual wastes and presents the 
Agency's rationale for the final listing decisions.
1. Crude Oil Storage Tank Sediment

Summary

    EPA is listing as hazardous crude oil storage tank sediment from 
petroleum refinery operations. This waste stream meets the criteria set 
out at 40 CFR 261.11(a)(3) for listing a waste as hazardous, because it 
may pose a substantial or potential hazard to human health or the 
environment. The Agency has identified substantial risks to consumers 
of groundwater associated with releases from off-site Subtitle D 
landfilling due to benzene, which EPA has decided will not be 
adequately regulated under the TC. The revised groundwater risk 
assessment results are summarized in Table IV-2.

Discussion

    The Agency proposed not to list as hazardous tank sediment from the

[[Page 42151]]

storage of crude oil at petroleum refineries, either on-site or at tank 
farms owned by or affiliated with the refineries or refinery companies. 
In the proposal, the Agency found risks at levels of potential concern 
(3E-5, high-end groundwater risk) associated with disposal in off-site 
landfills; however EPA believed that because the only constituent of 
concern, benzene, is already regulated under the TC, listing might not 
have been warranted. See 60 FR 57763. The proposal also reported low 
risks from carcinogenic PAHs potentially released from land treatment 
operations (60 FR 57762). The Agency solicited comment on the decision 
not to list this waste stream, particularly on whether the TC captures 
wastes of concern, whether the Agency adequately characterized the risk 
for this waste, and whether any other factors should be considered.
    The revised risk analysis presented in the NODA for land treatment 
continues to show insignificant risks (<1E-6) for this residual, and 
EPA did not conduct any further analysis on this management scenario. 
The high-end groundwater risks from the NODA analysis for landfills 
were essentially unchanged. Also in the NODA, EPA presented risk 
results to assess the potential impact of the TC regulation, (i.e., 
input levels to the groundwater model were capped at the TC regulatory 
levels) assuming that wastes above this level would be properly handled 
as hazardous. The TC-capping reduced the risks only slightly (2E-5). In 
addition, EPA provided a Monte Carlo analysis of the groundwater risks 
that were somewhat lower than the high-end risk at the 95th percentile 
(5E-6), but comparable at the 99th percentile (4E-5).
    In response to comments on the NODA, the Agency further revised the 
input data for the groundwater pathway analysis as noted elsewhere in 
this notice. As shown in Table IV-2, this final groundwater pathway 
analysis showed slightly higher high-end risks (4E-5) and Monte Carlo 
risks (1E-5 and 5E-5 at the 95th and 99th percentiles). As in the NODA 
analysis, the risks estimated with benzene input capped at the TC level 
were only slightly lower for the high-end analysis (3E-5) and Monte 
Carlo results (9E-6 and 2E-5 at the 95th and 99th percentiles).
    Following careful consideration, the Agency has decided not to rely 
on the TC to control the risks for crude oil tank sediment, because, as 
the TC-capped results suggest (risk up to 3E-5), the TC may not fully 
capture benzene risks for this waste. Thus, even assuming refineries 
properly handle wastes above the TC level, wastes below this level may 
present risk above 1E-5. Furthermore, this sediment waste appears to be 
stratified as it forms in the tank, and upper layers are often 
centrifuged to remove oil, but bottom layers may not be (see Listing 
Background Document, 1995, p. 32). Even if a refinery analyzes the 
waste, rather than simply using its ``knowledge'' as the generator 
waste determination regulations allow, collecting representative 
samples is challenging. Therefore, due to the oily, nonhomogeneous 
nature of this particular waste, sampling and TCLP analysis may be 
problematic.
    Moreover, although nongroundwater risks from land treatment are not 
significant, the carcinogenic PAH content of the waste is moderately 
high (e.g., up to 26 ppm of BaP; see 60 FR at 57762). As noted earlier 
in the discussion on groundwater issues (see Existing Groundwater 
Contamination in Section V.B.6), while EPA could not quantify any PAH 
risks from TCLP samples of this waste, the presence of carcinogenic 
PAHs in the waste pose some potential for additional risk, especially 
if transport is facilitated by existing contamination. While EPA is not 
using the presence of carcinogenic PAHs as the overriding factor in 
listing this waste, the presence of carcinogenic PAHs is a contributing 
factor EPA considered in listing crude oil storage tank sediment.

Specific Comments

    Some commenters supported EPA's proposed decision not to list crude 
oil storage tank sediment, noting that the Monte Carlo analysis 
strengthens this decision and highlights the conservatism in EPA's risk 
assessment for the high-end analysis. In response, EPA notes that the 
high-end risk (4E-5), in conjunction with the other factors noted 
above, merits listing of this waste. The revised Monte Carlo risk at 
the 95th percentile also are of concern (1E-5), albeit somewhat lower 
than the high-end analysis. (See Section V.B.6 for further discussion 
on the Monte Carlo analysis). Therefore, after considering a 
combination of factors, including significant groundwater risk (i.e., 
risks above 1E-5), and the levels of carcinogenic PAHs found in these 
wastes, EPA believes that a listing is warranted.
    Commenters opposing EPA's proposed decision not to list presented 
extensive comments on the risk analysis. These issues are already 
discussed in the portion of today's notice devoted to the Modeling 
Approach and Risk Assessment. Numerous comments challenged EPA's 
groundwater risk assessment, and one commenter provided alternative 
groundwater modeling that incorporated a variety of changes and 
purported to show higher risks for this waste than found by EPA. As 
noted in Section V.B.6, the Agency modified its modeling to reflect 
some changes, which resulted in somewhat higher groundwater risks for 
this waste, and EPA has now decided to list the waste.
    Comments supporting a listing also argued that the Agency had not 
evaluated the risks posed by management practices such as landfill 
daily cover, road spreading, and other uses constituting disposal. EPA 
disagrees as described in Section V.B.2; these are practices that were 
rarely practiced for this waste. In any event, the disposal practice 
modeled provided sufficient risk for EPA to list the waste.
    The comments also noted that the concentrations of key constituents 
in crude oil tank sediment (e.g., benzene and BaP) exceed those 
reported in other wastes EPA listed in 1990 (55 FR at 46365; November 
2, 1990). As EPA noted in the earlier discussion on consistency with 
past listings, a simple comparison of constituent levels can be 
misleading, because the Agency must consider many factors in its 
listing decision. Furthermore, EPA's risk assessment methodology has 
evolved since 1990. However, as noted above, EPA agrees that 
limitations in detection limits for the PAHs in the TCLP make it 
difficult for EPA to rule out potential groundwater risks completely. 
In any case, EPA notes that it has decided to list crude oil tank 
sediment as hazardous, primarily because of the risks from benzene, 
thus these comments are not critical to the final decision.
    One commenter stated that because of its variability, crude oil 
tank sediment is precisely the type of waste stream that is best 
regulated only if it exhibits hazardous characteristics. As noted 
above, however, EPA is not relying on the TC to control risks, because 
the results of the risk assessment show that this residual poses 
sufficient risk to warrant listing as hazardous even with the TC 
controls in place. Furthermore, the variability in this waste appears 
to exist even within wastes removed from the same tank. EPA's sampling 
visits indicate that this waste may form in layers in the tank, such 
that it is not homogeneous when removed and processed. During tank 
clean out, some of the oily sediment initially removed from the tank is 
often deoiled (e.g., via centrifuging), but other more viscous layers 
may not be (see Listing Background Document, October 1995).

[[Page 42152]]

Thus, even if a facility attempts to perform the TCLP test in good 
faith, sampling such a material is a difficult challenge and could lead 
to inaccurate results.
    Finally, consistent with the proposal, it is EPA's intent that the 
listing for crude oil storage tank sediment from refinery operations be 
limited in scope to wastes generated from tanks that are either on the 
refinery site, or at tank storage areas owned or under contract to the 
refinery. Thus, the listing does not apply to storage tanks upstream at 
exploration and production sites, or associated with pipelines or other 
crude oil transportation conveyances. EPA's meaning with respect to the 
term ``affiliated'' was to extend the scope of the listing to all tanks 
containing crude oil that are owned by the refinery and used in 
refinery operations. EPA has not collected data necessary to 
characterize non-refinery sediments. Furthermore, many of these non-
refinery materials are governed by special statutory provisions (i.e., 
the ``Bevill'' provisions), and are currently exempt from regulation as 
hazardous waste (See 60 FR at 57764.)
2. Clarified Slurry Oil Sediment

Summary

    EPA is listing as hazardous CSO storage tank sediment and/or in-
line filter/separation solids from the filtration of CSO from petroleum 
refinery operations. This waste stream meets the criteria set out at 40 
CFR 261.11(a)(3) for listing a waste as hazardous, because it may pose 
a substantial or potential hazard to human health or the environment. 
The Agency identified substantial risks to residents and home gardeners 
near on-site and off-site LTUs through direct ingestion of contaminated 
soil released from these units. The contaminants of concern, PAHs, also 
tend to accumulate in food sources such that this waste causes even 
higher risks to nearby subsistence farmers and fishers. EPA is not 
promulgating any of the proposed options for conditional listing, 
because revised risk analysis for releases from off-site landfills 
showed some risks of concern to consumers of groundwater (see Table IV-
2).

Discussion

    The Agency proposed to list sediment from CSO storage tanks 
(including solids from in-line filtration or separation of CSO) as 
hazardous, due to high-end cancer risks of up to 9E-5 and 8E-5 arising 
from receptors exposed to contaminated soil released from on-site and 
off-site LTUs respectively. High-end risks associated with the landfill 
disposal of this waste stream were below the 1E-6 level, and EPA 
proposed various options for a conditional listing that would allow 
nonhazardous landfill disposal, but prevent the practice of land 
treatment. (See 60 FR at 57776).
    In response to comments on the proposal, EPA modified the landfill 
and land treatment risk assessments and published revised risks in a 
NODA (see 62 FR at 16748). The overall risk pattern did not change 
significantly for land treatment. Specifically, for the on-site land 
treatment, the revised high-end risks increased slightly (up to 2E-4), 
and for off-site land treatment the revised risks decreased slightly 
(risks up to 3E-5)(see 62 FR at 16753). The revised high-end 
groundwater risks due to benzene from off-site landfill disposal 
increased from <1E-6 to 3E-6, and the Monte Carlo risks ranged from 1E-
6 to 3E-6 for the 95th and 99th percentiles.
    In response to comments on the NODA, the Agency further revised the 
input data for the groundwater pathway analysis as noted elsewhere in 
this notice. As shown in Table IV-2, this final groundwater pathway 
analysis showed slightly higher high-end risks (4E-6) and Monte Carlo 
risks (2E-6 and 4E-6 at the 95th and 99th percentiles) for off-site 
landfills. Based on the substantial risks arising from PAHs in land 
treatment of this waste, EPA has determined to list this waste as 
hazardous. At the time of proposal, EPA believed disposal of this waste 
in nonhazardous landfills did not appear to pose significant risks, and 
so raised the possibility of a conditional listing that would allow 
this practice to continue. The Agency has now decided not to include a 
conditional listing for this waste, primarily because landfilling of 
CSO residuals appear also to pose some groundwater risk as a result of 
the revised risk analysis (4E-6). Therefore, the Agency has decided not 
to proceed with this new concept with this waste. Furthermore, EPA is 
reluctant to encourage the landfilling of wastes with very high 
carcinogenic PAH content (e.g., up to 230 ppm of BaP), which, as noted 
above for crude oil storage sediment, may present risks if mobilized in 
groundwater under certain conditions.

Specific Comments

    Commenters responding to issues related to risk assessment of CSO 
tank sediment argued that results were insufficient for a listing 
determination because EPA found that 80 percent of the CSO tank 
sediment does not pose a risk to human health and the environment, and 
the remaining 20 percent of CSO tank sediment, disposed of in off-site 
LTUs, was determined to pose risk in the discretionary range only after 
imposing conservative assumptions.
    After revising its risk assessments and considering all comments, 
EPA disagrees with the commenter. Three subcategories of CSO sediment 
can be identified. The first consists of the residuals land treated, 
which were found to pose risk of concern via the risk assessment as 
described in the proposed rule and the NODA. This volume accounts for 
22 percent of the volume generated in 1992. The second consists of the 
residuals landfilled, which were not thought to pose risk of concern 
via the risk assessment as described in the proposed rule, and which 
account for 50 percent of the volume generated in 1992. The third 
consists of the balance of the residuals subjected to management 
practices in 1992, which were not modeled because either the practices 
were exempt (e.g., recycling), the residuals were already hazardous, or 
the management practices for very small volumes of the residuals were 
rarely practiced and/or adequately modeled by land treatment or 
landfilling (e.g., on-site road material).
    EPA reassessed the first two subcategories of CSO sediment 
(management in LTUs and landfills), after modifying a number of 
parameters and modeling considerations in response to public comment. 
CSO sediment, when land treated, continues to exhibit risk levels (up 
to 2E-4) supporting a listing determination, as described in the 
discussion above. Furthermore, the revised assessment showed that 
landfilled sediments also present some risks. Therefore, EPA has 
decided not to proceed with a conditional listing that would allow 
disposal in Subtitle D landfills, but rather is promulgating a full 
unconditional listing for this waste.
    As noted elsewhere in today's notice (Section V.B), EPA does not 
agree with other comments that argued EPA should have assessed risks 
from other management practices, such as use of CSO sediment as on-site 
road material. In any case, EPA is listing this waste as hazardous, 
thereby preventing such practices in the future.
    Some commenters argued that the waste constituent characterization 
related to analysis of the waste itself (not the TCLP extract) is 
uncertain and overestimates risks. Specifically, they argued that some 
PAHs were detected in only one sample at concentrations below the 
quantification limit (i.e., ``J'' values), and that where this 
concentration leads to an unacceptable risk estimate, CSO sediments for 
the

[[Page 42153]]

entire industry could be listed based on a single estimated 
concentration in one sample.
    EPA does not agree that any uncertainty in the analysis resulted in 
an overestimation of risk. First, EPA notes that even constituents 
assigned a ``J'' value were reliably detected in the waste, although 
the precise level has increasing uncertainty as the measurement 
approaches the detection limit. More importantly, contrary to the 
commenter's assertion, the CSO listing determination did not hinge on a 
single estimated value, but rather considered all of the constituents 
that showed risk. Several highly toxic PAHs detected in CSO tank 
sediment (BaP, benz(a)anthracene, dibenz(a,h)anthracene, 7,12-DBMA) 
were measured at levels above the quantification limits, and these 
constituents in the waste presented substantial risks (i.e., > 1E-5) 
without any consideration of ``J'' values.
    Commenters argued that EPA did not follow its own guidance in 
applying listing factors to CSO sediment, and that a description as to 
how each of the listing factors weighs for or against listing should be 
provided.
    In response, EPA first notes that all the factors in 40 CFR 
261.11(a)(3) are considered in this listing decision. The commenter has 
not specifically identified any Sec. 261.11(a)(3) factors that were not 
considered. Furthermore, EPA disagrees with the commenter and notes 
that its revised risk assessment fully supports the listing 
determination for CSO sediment and is in accordance with applicable 
guidance. The guidance the commenter cites is contained in the December 
22, 1994 proposed rule for the dye and pigment listings, in which EPA 
discussed the use of risk levels in making listing decisions (59 FR at 
66075-66077). EPA's decision to list this waste is consistent with the 
guidance, i.e., the risks associated with this residual are well above 
the 1E-5 listing benchmark.
    EPA received comments that the Agency overstated the potential 
risks from CSO sediment that is land treated, and that there are no 
documented damage cases involving migration of PAH contaminated soils 
from land treatment of CSO sediments.
    In response, EPA points out that it attempted to identify damage 
cases wherever possible to support its listing determinations (See 
Assessment of Risks from the Management of Petroleum Refining Wastes: 
Background Document, October 1995, in the docket). While EPA has 
identified damage cases resulting from releases at petroleum 
refineries, it was not possible to tie the releases directly to CSO 
sediments (or other wastes under review in this rule) in LTUs due to 
(1) the management of multiple residuals in LTUs, (2) the infrequent 
generation of CSO sediments, and (3) the lack of a marker contaminant 
unique to CSO sediments that could be linked to documented releases. 
The lack of empirical evidence is not surprising, but does not prove 
that releases are not possible or even unlikely. For this reason, EPA 
did not rely heavily on damage cases that directly linked releases to 
the specific residuals of concern. Instead EPA's weight of evidence 
considerations emphasized its data collection efforts (i.e., the 3007 
Questionnaire and field study) that provided EPA with the raw material 
to evaluate a wide variety of measures of risk (e.g., modeling of 
numerous pathways, groundwater modeling, hazardous waste 
characteristics). By using information beyond proven damage cases, EPA 
hopes to prevent releases that lead to environmental damage.
    Several commenters requested that EPA clarify the definition of the 
K170 listing for CSO waste. Their questions relate to whether the 
listing: (1) applies just to CSO separately stored/managed or also to 
all mixtures of CSO and other fuels, (2) includes fluidized catalytic 
cracker (FCC) clean out/turnaround sediments, (3) includes sediments 
from ``affiliated'' tank farms, and (4) includes spills of CSO.
    Concerning mixtures of CSO and other fuels, EPA points out that any 
sediments derived from CSO or CSO mixtures are considered K170 because 
of the contribution of the CSO sediment to the ultimate residual. All 
tanks that hold CSO have the potential to generate CSO sediment, and 
this sediment may mix with sediment generated by other materials stored 
in the tanks. Thus, the resulting sediment mixture would be classified 
as hazardous waste K170 under the ``mixture'' rule (see 40 CFR 
261.3(a)). The Agency anticipates that refiners will use the 6-month 
period between the final rule date and the effective date to remove 
``marginal'' storage tanks from service for sediment clean out and 
subsequently use dedicated tank service for CSO storage to minimize the 
number of tanks generating the listed hazardous waste.
    Concerning clean out/turnaround sludges, throughout the EPA's 
industry study, the Agency intended to incorporate clean out/turnaround 
sludges from in-line particulate removal units within the scope of the 
CSO sediment definition (see the 1995 Listing Background Document at 
page 43). One primary component of these sediments and storage tank 
sediments is FCC catalyst fines. Samples were collected from three 
storage tanks and one in-line filter. No samples of turnaround 
sediments were available during the Agency's field investigation; 
however, several refineries described the removal of sediments from 
other in-line separation units such as hydroclones during turnarounds. 
EPA believes that sediments removed from the hydroclone during 
turnarounds would be comparable to sludges removed from in-line filters 
which serve the same purpose, because both are designed to perform the 
same function, i.e., to remove solids from lines leading to CSO tanks. 
No information was submitted by the commenters to demonstrate that 
clean out/turnaround sediments from such in-line separation devices 
differ from storage tank sediments.
    The Agency therefore continues to use the broader definition of CSO 
sediments, which includes sediments collected in filters and other 
separation devices in lines that move the CSO from the FCC unit to 
storage tanks. EPA does not, however, expect that all residuals 
generated during FCC turnaround would be classified as K170, but rather 
only those associated with in-line particulate removal equipment (e.g., 
hydroclones, in-line filters). This would not include sediments and 
tars that may accumulate within the distillation columns.
    EPA's meaning with respect to the term ``affiliated'' was to extend 
the scope of the listing to all tanks containing CSO that are owned by 
the refinery that produced the CSO. (See 60 FR at 57766). This CSO has 
not yet been sold or transferred to another entity or corporation, and 
remains the property of the refinery from which it originated. All 
sediments settling from the CSO prior to sale are subject to the 
hazardous waste listing. Similarly, once the CSO has been sold or 
transferred in commerce, it is no longer under control of the producing 
refinery. The listing determinations in today's rule are for wastes 
generated from refinery operations, thus EPA has not examined for this 
rule whether other sediments might be generated, and if generated, 
under what conditions, after the CSO has been sold or transferred.
    Concerning spills of CSO product, EPA does not intend to regulate 
as hazardous the CSO itself, only the sediments that are removed from 
this hydrocarbon product such as those generated in in-line separators 
and those sediments that gravitate to the bottom of storage tanks. CSO 
that is accidentally spilled on the ground may in fact

[[Page 42154]]

contain particulates that would have settled out as tank sediment. 
However, the Agency did not address such spills in the proposed rule 
and, in response to this comment, is clarifying that it does not 
currently intend to regulate CSO spills as K170. Spills of K170 waste, 
of course, would be regulated.
    One commenter noted that EPA should consider an exemption from 
designation as hazardous for CSO sludges that are de-oiled, and claimed 
that de-oiled solids may be managed similarly to FCC catalyst and fines 
units because they are very similar in composition (i.e., the wastes 
would be landfilled and should not present a risk). The commenter 
argued that providing a conditional exemption for de-oiled sludges, 
perhaps with separate Land Disposal Restrictions (LDR) treatment 
standards, would be environmentally sound, and would tailor treatment 
to the nature of the waste stream.
    EPA did consider whether the data available allow the Agency to 
distinguish between CSO sediment (as well as crude oil storage tank 
sediment) before and after de-oiling, especially for use in risk 
assessment. However, the Agency concluded that distinguishing between 
the two forms of CSO sediment was inappropriate based on the data 
available (see Listing Background Document, 1995, pages 46 and 29). 
Therefore, EPA disagrees with the commenter's suggestion to only list 
``non-deoiled'' sediment because: (1) Available data do not provide a 
sufficient comparison differentiation of risks between oily and de-
oiled CSO tank sludges, (2) the deoiling process may not remove the 
PAHs of concern, and (3) crafting a definition of de-oiled sludges 
would be difficult and may cause enforcement problems. Furthermore, as 
shown by the high PAH content in CSO sediment, the solids appear to be 
more than just spent FCC catalyst. EPA believes the exclusion for 
recycled oil-bearing residuals that EPA is promulgating in today's rule 
is a more effective approach to encouraging the recycling of the 
material.
3. Catalyst From Hydrotreating and Hydrorefining

Summary

    EPA is listing as hazardous spent hydrotreating and hydrorefining 
catalysts from refining operations. This waste stream meets the 
criteria set out at 40 CFR 261.11(a)(3) for listing a waste as 
hazardous, because it may pose a substantial or potential hazard to 
human health or the environment. The Agency identified substantial 
risks to consumers of groundwater associated with releases from on-site 
and off-site Subtitle D landfilling due to benzene and arsenic, which 
EPA has decided will not be adequately regulated under the TC. The 
revised groundwater risk assessment results are summarized in Table IV-
2. In addition, these materials also present a hazard because of their 
pyrophoric and self-heating properties.

Discussion

    The Agency proposed to list spent hydrotreating and hydrorefining 
catalysts from refining operations due to high-end cancer risks of up 
to 1E-5 and 6E-5 respectively arising from releases of benzene and 
arsenic to groundwater from landfill disposal. (See 60 FR at 57766-
57768). In addition, as the Agency discussed in the proposed notice, 
these materials also present a hazard because of their potential to 
spontaneously ignite when removed from the processing unit and exposed 
to air.
    The revised groundwater risks in the NODA increased substantially 
for these scenarios when compared to the proposed rule. The high-end 
risks for hydrotreating catalyst were up to 7E-5 for off-site landfills 
and up to 8E-5 for on-site landfills. For hydrorefining catalyst, the 
high-end risks were up to 7E-4 for off-site landfills and 4E-4 for on-
site landfills. The TC-capping assessment in the NODA resulted in some 
decrease in risks from benzene compared to the proposal, while the 
arsenic risks showed little or no decrease. Thus the maximum high-end 
risks were not materially affected. In addition, EPA provided a Monte 
Carlo analysis that yielded somewhat lower groundwater risks; however, 
as noted in an earlier section, EPA subsequently revised the Monte 
Carlo analysis.
    As a result of the revised risk analysis completed in response to 
comments on the NODA, the off-site landfill groundwater risks increased 
further. As shown in Table IV-2, the revised off-site risks for 
hydrotreating catalyst are 1E-4 for benzene and 8E-5 for arsenic; the 
TC-capped results for this waste showed lower risk for benzene (3E-5), 
but arsenic was unchanged. Similarly, the revised off-site risks for 
hydrorefining catalyst are 7E-5 for benzene and 6E-4 for arsenic, and 
the TC-capped analyses for these wastes lowered the benzene risks (3E-
5) but had no impact on arsenic risk. The revised Monte Carlo risks for 
hydrotreating catalyst (benzene 3E-5, arsenic 2E-5 at the 95th 
percentile) and hydrorefining catalyst (benzene 2E-5, arsenic 4E-4 at 
the 95th percentile) were somewhat lower, but still well above the 
listing benchmark of 1E-5. As in the NODA analysis, the high-end and 
Monte Carlo risks for arsenic were not lowered by the TC-capped 
analysis. The TC-capped benzene risks for both catalysts were somewhat 
lower in the high-end (both at 3E-5) and Monte Carlo analyses (9E-6 and 
8E-6 for the hydrotreating and hydrorefining risks respectively).
    EPA believes that the overall results are strongly supportive of 
listing both spent catalysts. Even in the TC-capping results, both 
catalysts present risks in off-site landfills that exceed 1E-5. 
Specifically, for both hydrotreating and hydrorefining catalysts, the 
TC-capped arsenic risks exceed 1E-5 for the Monte Carlo and high-end 
evaluations, and the benzene risks exceed this benchmark in the high-
end evaluation and approaches this level in the Monte Carlo analyses. 
As shown by the TC-capped modeling analysis, the risk levels may remain 
at levels of concern, even assuming wastes above the TC level are not 
disposed of in nonhazardous landfills.
    In addition to the groundwater risks posed by these materials, the 
pyrophoric and self-heating nature of these catalysts also support 
EPA's conclusion that these materials present a substantial hazard. 
During several site visits to catalyst reclaimers, EPA observed smoking 
catalyst storage areas used to stage the catalysts immediately prior to 
insertion into the reclamation process. One facility told EPA during 
the site visit that fires occur every few months. These areas were 
carefully monitored and controlled, but clearly the materials exhibited 
pyrophoric properties. In addition, the refineries generating these 
residuals described the significant risks during reactor turnaround 
associated with the potential pyrophoric nature of these catalysts. 
Therefore, EPA believes that it has solid basis for using the potential 
self-igniting characteristic of these catalysts to support its decision 
to list these residuals.
    EPA wishes to clarify the scope of these listings, however. In the 
proposal, the Agency indicated that the listings would not include 
ceramic support media that are separated from the spent hydrotreating 
or hydrorefining catalyst prior to catalyst disposal or recycling, 
because these support media are inert, separate from the catalyst, and 
commonly reused or sent for cleaning prior to reuse. (See 60 FR at 
57780). EPA continues to believe this is appropriate. Some commenters 
requested that EPA modify the regulatory language to refer to ``inert 
support media,'' rather than the proposed ``ceramic support media,'' 
because other types of inert materials are used, such as stainless 
steel. EPA agrees that the commenter's language

[[Page 42155]]

better reflects the Agency's intentions, and is modifying the exemption 
language in 40 CFR 262.3(c)(2)(ii)(E) and the listing descriptions for 
K171 and K171 to reflect this change.
    In the proposed rule EPA also noted that the terms 
``hydrotreating'' and ``hydrorefining'' are somewhat loosely used 
within the industry. Several commenters requested a more concise 
definition of the terms to clarify the definitions of hydrotreating, 
hydrorefining, and hydrocracking processes. EPA provides further 
discussion of the definitions of these wastes in the following section 
on residual-specific comments. EPA is modifying the final regulatory 
language slightly to clarify this issue, as noted in Section IV.B.

Specific Comments

Definition of Hydrotreating and Hydrorefining Catalysts

    EPA examined three types of hydroprocessing catalysts identified in 
the EDF consent decree: hydrotreating catalyst (listing candidate), 
hydrorefining catalyst (listing candidate), and hydrocracking catalyst 
(study residual). Spent hydrotreating and hydrorefining catalysts have 
been proposed for listing and will be promulgated as hazardous wastes 
in today's rule; no action has been proposed to date for spent 
hydrocracking catalyst. (However, the listing of the spent 
hydrotreating and hydrorefining catalysts does not release the 
generator from determining whether spent hydrocracking catalyst is a 
hazardous waste due to the characteristics under 40 CFR 262.11). Public 
comment was submitted regarding EPA's hydroprocessing catalyst 
definitions.
    All three processes are part of a continuum of catalytic 
hydroprocessing units. Definitions for the three categories of 
hydroprocessors are not universally established or accepted. In 
general, the three processes may be viewed in the following order of 
increasing degrees of severity of operating conditions and conversion 
of larger hydrocarbons to smaller molecules (``cracking''), and/or 
feeds: hydrotreating, hydrorefining, and hydrocracking. The types of 
catalysts used can be similar in all three processes.
    The proposed regulatory language did not attempt to define these 
catalysts, or differentiate them from hydrocracking catalysts. The 
proposal referred to definitions used in the Oil and Gas Journal (60 FR 
at 57767, fn. 7), which indicates that hydrotreating includes processes 
where essentially no reduction in the molecular size of the feed 
occurs, that hydrorefining includes processes where 10 percent of the 
feed or less is reduced in molecular size, and that hydrocracking 
includes processes where 50 percent of the feed or more is reduced in 
molecular size.
    Commenters on the proposal noted that the preamble definitions did 
not provide a complete continuum, resulting in an unclear area between 
hydrorefining and hydrocracking. Specifically, since hydrorefining 
covered conversion rates up to 10 percent and hydrocracking covered 
conversion rates greater than 50 percent, as defined by the Oil and Gas 
Journal, it was not apparent how EPA would classify processes with 
conversion rates between 10 and 50 percent. Several solutions were 
suggested by the commenters:

    One refiner suggested that EPA establish a definition of 
hydrocracking that assumes a conversion rate of 15 percent or 
greater and the use of downstream fractionation.
    A catalyst reclaimer suggested extensive regulatory language 
describing the specific types of catalysts, catalysts support media, 
and catalytic applications associated with the different 
hydroprocessing categories.
    Other refiners commented that EPA should clarify that any 
process with conversion rates greater than 10 percent should be 
classified as hydrocracking.

Each of the options is problematic. Reliance on specific conversion 
rates may allow for slight changes in operating and accounting 
practices to result in reclassification of units that would otherwise 
be considered hydrorefiners. Similarly, use of fractionation could be 
interpreted to include stripper columns commonly employed after 
hydrotreating and hydrorefining. The catalyst reclaimer's suggested 
language was an exhaustive attempt to distinguish the types of 
processes EPA intends to be within the scope of the listings; however, 
other commenters argued it was inappropriate to adopt the reclaimer's 
suggestion because EPA did not have sufficient basis to expand the 
definition in this way. At this time, the Agency is reluctant to adopt 
this extensive list within the regulatory language without additional 
review and perhaps further information collection.
    Upon reviewing all of the relevant materials available in the 
docket, the Agency believes that the simplest way to differentiate 
between hydrocracking units and other hydroprocessing units is to rely 
on the categorization used in the DOE's Petroleum Supply Annual. 
Refineries are required to submit Form EIA-820 annually to DOE's Energy 
Information Administration. This form includes the mandatory submission 
of data on operating capacity for catalytic hydrocracking and catalytic 
hydrotreating. Catalytic hydrocracking is defined in the Petroleum 
Supply Annual as:

    A refining process that uses hydrogen and catalysts with 
relatively low temperature and high pressures for converting middle 
boiling or residual material to high-octane gasoline, reformer 
charge stock, jet fuel, and/or high grade fuel oil. The process uses 
one or more catalysts, depending upon product output, and can handle 
high sulfur feedstocks without prior desulfurization.

    In addition, catalytic hydrotreating is defined in the Petroleum 
Supply Annual as:

    A refining process for treating petroleum fractions from 
atmospheric or vacuum distillation units (e.g., naphthas, middle 
distillates, reformer feeds, residual fuel oil, and heavy gas oil) 
and other petroleum (e.g., cat cracked naphtha, coker naphtha, gas 
oil, etc.) [i]n the presence of catalysts and substantial quantities 
of hydrogen. Hydrotreating includes desulfurization, removal of 
substances (e.g., nitrogen compounds) that deactivate catalysts, 
conversion of olefins to paraffins to reduce gum formation in 
gasoline, and other processes to upgrade the quality of the 
fractions.

For the purposes of the K171 and K172 listing descriptions, catalytic 
hydrorefining is defined as a refining process with more severe (higher 
temperature and pressure) operating conditions than the catalytic 
hydrotreating process defined above for treating the heavier molecular 
weight petroleum fractions, residual fuel oil and heavy gas oil.
    Based on the Petroleum Supply Annual definitions stated above, if a 
refinery has been classifying its hydroprocessor as a catalytic 
hydrocracker for the purposes of the DOE's Form EIA-820, spent catalyst 
from this unit would not be covered by K171 or K172 (with the exception 
of guard beds, as discussed further below). Conversely, if a refinery 
has been classifying its hydroprocessor as a hydrotreater processing 
feeds other than residual fuel oil or heavy gas oil, spent catalyst 
from this unit would be classified as K171; spent catalyst from a 
similar unit processing residual fuel oil or heavy gas oil would be 
classified as K172. Refineries have been reporting capacity information 
to DOE for many years and today's rulemaking should serve as a 
reference for the classification of these units.
    In addition to the issue of defining hydrocracking units that are 
not subject to the K171/K172 listing, there is

[[Page 42156]]

disagreement among commenters from the petroleum industry and catalyst 
reclaimers regarding the classification of guard beds. These units, 
also known as desulfurization pretreaters, are used to extend the life 
of the downstream catalytic bed (e.g., reformer, hydrocracker, 
isomerization reactor) by removing sulfur, oxygen, nitrogen, and/or 
heavy metals. Reclaimers argued to include such pretreatment of 
hydrocracker feeds, sulfur guards, reformer pretreatment, and 
isomerization pretreatment as part of the definition of hydrorefining 
or hydrotreating. The petroleum refining industry disagreed, stating 
that these pretreatment processes use more severe conditions (much 
higher pressure, high ratio of hydrogen to hydrocarbon) to achieve 
contaminant removal, and also provide a significant reduction in 
feedstock molecular size, often greater than the 10 percent cutoff in 
the EPA/Oil and Gas Journal hydrorefining definition. Thus, industry 
contends such catalysts more appropriately belong in the hydrocracking 
category.
    EPA agrees that these pretreatment units, or ``guard units,'' 
should be covered under the listing descriptions in today's rule.

In reviewing the 3007 Questionnaire responses, EPA found that some 
refineries reported the catalysts from their guard beds under the 
category of the downstream unit. For example, nickel/molybdenum 
catalyst from a reformer pretreatment unit was sometimes reported as 
spent reforming catalyst, however, true reforming catalysts are based 
on precious metals such as platinum and palladium. EPA believes that 
these units were not reported as hydrotreaters because they often 
reside within the unit boundaries of the downstream units, are closely 
integrated with the downstream units, and such reporting simplified the 
refinery's response to the extensive 3007 Questionnaire. However, 
because this type of guard bed does not result in catalytic reforming 
(and similarly isomerization), these units were re-coded as 
hydrotreaters in the Agency's database. EPA has modified the regulatory 
language to clarify that the spent catalyst from all such pretreatment 
units should be classified as K171 or K172.

Risk Assessment and Basis for Listing

    Some commenters stated that EPA's groundwater analysis understated 
the risks for these wastes. These comments reflected many of the issues 
already discussed in the portion of today's notice devoted to the 
Modeling Approach and Risk Assessment, but the Agency notes a few 
issues specific to these wastes. Despite the commenters' arguments, EPA 
remains convinced that it is appropriate to use the TCLP to 
characterize the leaching potential of these residuals, as noted in 
Section V.B.1. The Agency's analysis of total oil and grease content of 
the catalysts showed very low oil and grease content (less than 0.2 
percent) for the six samples for which EPA was able to conduct total 
oil and grease analysis, thus these are not the ``oily'' wastes that 
the commenter believes represent a problem for the TCLP. As the 
commenters noted, EPA did not consider codisposal for these wastes. 
However EPA believes it would be inappropriate to assess the impact of 
codisposal of the catalyst residuals with other refinery wastes because 
EPA is listing these wastes, and thus they must be disposed of in 
Subtitle C units in the future.
    Several commenters argued that EPA's analysis overestimated risks 
in the Agency's assessment of spent catalysts from hydrotreating and 
hydrorefining for various reasons. These commenters argued that EPA 
data shows that 81 percent of these catalysts are already recycled or 
reclaimed, but EPA assumed in its risk analysis that all this material 
will go into landfills.
    EPA disagrees with this comment. The Agency chose landfill disposal 
as the mismanagement scenario for the groundwater risk analysis for 
these wastes, because economic considerations and other information in 
the record show that the recycled material could plausibly go to 
landfills.
    To calculate waste volumes to use as input to the modeling, EPA 
evaluated the data in two ways: (1) EPA arrayed the volumes disposed in 
on-site and off-site Subtitle D landfills in 1992 and determined the 
50th and 90th percentile quantities (Tables 3.3.4 and 3.3.11 of the 
1995 Listing Background Document), and (2) EPA arrayed the volumes for 
all volumes generated by any facility regardless of the actual 
management method (except for excluding wastes sent to Subtitle C), and 
determined the 50th and 90th percentile quantities for these wastes. 
EPA has used the second set of statistics in its risk assessment. Use 
of these data reflects the real potential that shifts might occur in 
management practices away from recycling and toward less expensive 
landfilling if the wastes are not listed (see a discussion of this 
issue in the Listing Background Document, 1995, pp. 78-79). Support for 
this assumption is found in industry comment that refineries may send 
spent catalysts to either recycling or landfill disposal, depending on 
the associated costs. During site visits to both refineries and 
catalyst recyclers, EPA learned that factors affecting spent catalyst 
management include the price of metals, and consequently the value of 
spent catalyst, and corporate policies toward recycling versus 
landfilling. For example, one report from a visit to a refinery 
(document # 95-PRLP-S0041) states: ``the spent catalyst is sent off-
site for metals reclamation or to a special waste landfill, depending 
on market conditions.'' Another report from a site visit to a reclaimer 
(95-PRLP-S0057) states that the company's fee structure is driven by 
metals prices, and their costs and/or credits are dependent on the 
current metals market. The reclaimer noted that more spent catalyst is 
reclaimed when metal prices are high than when prices are low. EPA 
therefore believes that management patterns of these particular 
residuals could change in the future.
    EPA only applied this assumption to three wastes (K171, K172, and 
spent catalyst from sulfur unit tail gas treating units), because these 
are all similar spent catalysts that are recycled at the same 
facilities. EPA did not project changes in waste management practices 
for other residuals, because the Agency has no specific information 
that such changes are plausible or that special trends in management 
practices exist. As noted in Section V.B.2, for the remaining 
residuals, EPA considered that 1992 provided a reasonable picture of 
the petroleum refining industry's practices.
    Moreover, comparison of the two data sets shows the commenters' 
concern that the approach used overestimates risks is unfounded. The 
high-end (90th percentile) annual volumes calculated for both 
approaches are nearly identical for hydrotreating catalyst, 70 metric 
tons (MT) for the first approach versus 77 MT for the second. For 
hydrorefining catalyst, use of volumes that are recycled actually 
reduced the high-end volume somewhat, from 2,250 to 500 MT. (Note that 
the decrease in the 90th percentile in this case is because the 
addition of the recycled volumes creates a larger data set, and the 
90th percentile point in the set is lowered for that in the smaller 
data set for volumes sent to landfills). Thus, EPA's approach does not 
overestimate risks.

TC-Capped Modeling

    One commenter argued that EPA should not list hydrotreating 
catalyst because, based on the TC-capped modeling analyses EPA 
performed for the NODA, the risks for spent

[[Page 42157]]

hydrotreating catalyst disposal in landfills range from 2E-5 to 4E-6 
from exposure to benzene (See 62 FR at 16752), and that these risk 
levels are within EPA's discretionary range for not listing. One 
commenter stated that EPA appropriately reported the risks from arsenic 
as not applicable because spent catalysts containing arsenic at levels 
sufficient to pose such risks are already covered by the TC Rule and 
regulated under RCRA. The commenter also argued that the risks found in 
the Monte Carlo analysis for hydrotreating catalyst were only 4E-6 at 
the 95th percentile, and, thus, support a no-list decision.
    EPA disagrees with the commenters. First, the commenters are 
mistaken in suggesting that the arsenic risks are not applicable for 
the TC-capped analysis. On the contrary, the risks do not change under 
this assumption because none of the samples exceeded the TC level for 
arsenic. As such, under the TC-capped analysis the arsenic risks would 
remain the same as the uncapped analysis. As noted in the Discussion 
section above, EPA continues to believe that the risks from the high-
end analysis fully support listing this waste, and the somewhat higher 
revised groundwater risks further support EPA's decision. Even for the 
TC-capped results, the revised arsenic high-end risks (8E-5) and Monte 
Carlo results (2E-5 at the 95th percentile), as well as the high-end 
risk for benzene (3E-5) clearly exceed the listing benchmark of 1E-5.
    Commenters also argued that for hydrorefining wastes, TC-capped 
groundwater risks from benzene range from 2E-5 to 6E-6 (See 62 FR at 
16752), and these risk levels are within EPA's discretionary range for 
listing (See 59 FR at 66073). While the comments conceded that the TC-
capped risk for arsenic in this waste are in the range EPA could 
consider for listing (4E-4 to 1E-4), the fact that the peak arsenic 
concentrations may not reach the receptor well until 3400 to 8400 years 
after release, indicates that this is not significant. The commenters 
also noted that the risks from benzene and arsenic cannot be added 
because the time for peak concentrations at the well is much shorter 
for benzene (13-50 years). The commenters argued that EPA should base 
its decision on the lower Monte Carlo results (TC-capped risk of 6  x  
10-6 at the 95th percentile for benzene).
    EPA disagrees with the commenters. As noted in the Discussion 
section above, EPA continues to believe that the risk analyses fully 
support listing this waste, and the somewhat higher revised groundwater 
risks further support EPA's decision. Even for the TC-capped results, 
the revised Monte Carlo and high-end risks for arsenic (4E-4 at the 
95th percentile and 6E-4), and the high-end risk for benzene (3E-5) 
clearly exceed the listing benchmark of 1E-5. Contrary to what the 
commenter implied, EPA did not add the benzene and arsenic risks, 
because of the large differences in travel time. Further, EPA did not 
discard the arsenic risk results merely because the modeling suggested 
the constituent may not reach the receptor well in the near future. The 
timeframe for travel may be uncertain, but the results suggest arsenic 
will be a serious problem when it reaches the well.
    EPA received comments stating that spent catalyst residuals should 
not be listed based on the characteristic of ignitability, because the 
spent catalysts do not demonstrate the property of self-heating, nor do 
they fail the ignitability test.
    As noted in the discussion above, persistent smoldering fires that 
may propagate to other codisposed materials have been reported for 
these residuals. Thus, listing of these wastes is further supported by 
actual environmental and health damages. Actual damages constitute one 
of the factors to be considered in listing wastes as hazardous under 40 
CFR 261.11(a)(3)(ix). As noted previously, it is rare to have actual 
damage cases to be attributable specifically to the wastes being 
listed. The fact that EPA has knowledge of actual damage cases for 
these wastes gives special support to their listing determination. 
Furthermore, under the mismanagement criterion of 40 CFR 
261.11(a)(3)(vii), it is appropriate to consider the physical 
properties of these wastes that may result in hazards if there is 
improper management through co-management with combustibles. Therefore, 
EPA considers the self-heating physical property of these spent 
catalysts to be very important in its decision to list these wastes.
    With regard to commenter opinion that a listing is not warranted to 
protect against fires resulting from spent catalyst being landfilled, 
EPA observed and was told by catalyst reclamation and refinery facility 
operators that these wastes exhibit pyrophoric properties and do result 
in fires. Even where catalysts are coated with heavy oils to reduce 
pyrophoric properties, this effect is not permanent as the oil coating 
degrades, particularly if the material is disturbed at a later date and 
exposed to the air, as could easily happen at landfills. EPA, 
therefore, has a solid basis for using the potential self-igniting 
characteristic of these catalysts to support its decision to list these 
residuals

Impact of Listing on Recycling

    EPA received a request for confirmation that solids generated from 
scrubbers used to control emissions during the reclamation and 
processing of spent hydrotreating and hydrorefining catalysts will not 
be designated hazardous under the ``derived from'' definition as a 
result of these proposed rules. The Agency points out that the 
commenter is incorrect. In general, wastes generated from the treatment 
of listed hazardous wastes are considered hazardous wastes, under 40 
CFR 261.3(c)(2). This includes residuals generated by the recycling 
activities described by the catalyst reclaimers who submitted comments 
on this rule. Wastes generated in the manner described by the commenter 
(e.g., ``derived from'' air pollution control wastes) would continue to 
carry the hazardous waste code and be subject to land disposal 
restrictions.
    EPA received several comments regarding the impact of this listing 
on recycling and management practices. Commenters noted that spent 
catalyst can be generated such that it meets the LDR UTS for organics, 
and that the metals of concern can be treated using metal fixation. 
This would be relatively inexpensive compared to the increased cost of 
recycling that will result from this listing, and might discourage 
recycling.
    EPA does not agree with the commenters' scenario for several 
reasons. First, the treatment standards for the spent catalysts require 
that any treatment reduce levels of organics to low levels. For 
example, nonwastewater levels of benzene, toluene, and xylene must be 
10 mg/kg or lower, and levels of naphthalene and phenanthrene are set 
at 5.6 mg/kg. Because the K171 and K172 wastes each frequently contain 
reactive sulfides and as a result may exhibit self-heating pyrophoric 
properties, the Agency also listed reactive sulfides as one of the 
hazardous constituents of concern in these wastes and specifically 
proposed to apply deactivation to these wastes. Thus, EPA does not 
believe it is likely that generators can meet all applicable LDR 
standards without appropriate treatment, such as treatment at a 
recycling facility. EPA concedes that listing may increase costs for 
recycling, however, EPA is not convinced that costs for other forms of 
treatment and disposal would be appreciably less. In any case, EPA's 
decision to list these materials is based on the risks they pose, and 
how this listing may

[[Page 42158]]

ultimately affect competing treatment technologies is not a central 
issue in the Agency's decision.
    Other commenters pointed out that current recycling of these 
catalysts has been due, in part, to the economics of reclamation 
compared to disposal. A listing would, however, disproportionately 
increase costs of and liability concerns about recycling. Some 
commenters noted that by listing these wastes, transportation costs 
will become a significant factor as materials will need to be 
transported as hazardous, regardless of their characteristics; 
increased transportation costs would strongly favor local disposal at a 
Subtitle C facility, and generators would be less likely to ship wastes 
farther distances to recycling facilities. Another commenter suggested 
that a listing will decrease recycling, and increase the demand for 
virgin metals. Thus, the overall environmental benefits from the 
listing determination are likely to be negative, because there will be 
more disposed of catalyst, and more production of virgin metals.
    EPA cannot know precisely what the ultimate costs will be for 
refineries to recycle or dispose of spent catalysts. The Agency 
believes the liability concerns described will continue to play a role 
in both landfilling and recycling decisions upon promulgation of this 
listing. The affected industry must first explore means to eliminate or 
minimize the newly listed waste, and then to optimize recycling, 
treatment, and management of remaining wastes. The basis of EPA's 
listing decision, however, centers on the results of its risk 
assessment, which demonstrates that these materials pose a potential 
risk to human health and the environment, and warrant Subtitle C 
control. The Agency also points out that, because of the listing, the 
recycling/disposal cost differential may arguably be reduced or 
reversed, because Best Demonstrated Available Technology (BDAT) and 
Subtitle C disposal costs will greatly increase the costs of disposal 
over the current practice of Subtitle D landfills. Thus, recycling is 
likely to continue to be an effective management option for these 
residuals.
    Furthermore, based on EPA's discussions with the recycling industry 
(see discussion of metal reclaiming for hydrotreating catalyst in 
Listing Background Document, 1995, pages 76-79), many of the reclaimers 
currently have RCRA storage permits to allow them to manage 
characteristically hazardous catalyst, so it is not clear that the 
costs for recycling should increase significantly due to listing. Even 
if recycling costs may increase as a result of this rule, EPA continues 
to believe that it is completely appropriate to bar these materials 
from Subtitle D disposal because of the risk levels identified through 
the Agency's risk assessment procedures. EPA has no evidence, nor did 
commenters provide any, to support the supposition that the listing 
would increase demand for virgin metals.
    Many commenters requested that the Agency consider an exemption for 
the regeneration/reclamation/recycling of spent catalyst. The catalysts 
would be listed only if they are disposed of in a landfill (or, 
alternatively, not recycled). Other commenters proposed a conditional 
listing for catalyst residuals going to land disposal. The suggested 
conditions include that the residual is sent to metals reclaiming, 
catalyst regenerators, or other recycling or reuse (provided it is not 
a ``use constituting disposal''), records are kept on recycling and 
reuse, and that self-heating residuals are shipped in Department of 
Transportation (DOT) bins. The commenters argue that such a listing 
would encourage recycling rather than landfilling.
    EPA believes that the catalyst wastes present several risks beyond 
those necessarily associated with landfill disposal, including 
pyrophoric properties and significant levels of benzene and arsenic 
(all of which may pose risks via pathways other than groundwater 
exposure, including risks from improper storage or other handling, and 
risks from uncontrolled air emissions from thermal treatment). Thus, 
this waste is not a good candidate for a conditional listing. Given the 
hazardous nature of this waste, EPA believes it is entirely appropriate 
for it to be transported and stored as hazardous waste before 
recycling. (See 40 CFR 261.6 for regulations applicable to hazardous 
wastes that are recycled). EPA points out that examples of problems at 
sites recycling these wastes have been noted in the record (see 
enforcement case described in the docket, document #PRA-S0037).
4. Catalyst From Sulfuric Acid Alkylation

Summary

    The Agency is not listing as hazardous catalyst from sulfuric acid 
alkylation, as proposed. EPA hereby incorporates, as a final decision, 
the proposed preamble discussion for this waste stream at 60 FR 57768-
57769. The residual is managed almost entirely (> 99 percent) under an 
existing exemption from the definition of solid waste (40 CFR 
261.4(a)(7)). Also, this residual consistently exhibits the 
characteristic of corrosivity and is subject to regulatory control if 
not returned to the production of virgin sulfuric acid. No significant 
comments against this decision not to list were received during the 
public comment period. Therefore, EPA has no basis to change the 
decision not to list.
5. Spent Caustic From Liquid Treating

Summary

    EPA is issuing a final decision not to list spent caustic from 
liquid treating as a hazardous waste. About 70 percent of the spent 
caustic is managed in ways that are exempt from RCRA regulation, 
because it is reused as an ingredient in producing other products. The 
Agency has identified certain management practices used for spent 
caustics for which the Agency is clarifying the application of the 
definition of solid waste, and in one case proposes a modification to 
the definition.
    Almost all of the remainder is sent to regulated wastewater 
treatment systems in such small volumes relative to other discharges, 
that the diluted constituents of concern from the spent caustics are 
not expected to present any significant risk. Furthermore, any solids 
from the caustic that separate out prior to downstream biological 
treatment are already regulated as hazardous wastes.
    After analyzing other potential exposure pathways, EPA concluded 
that with regard to any remaining risks, with the exception of air 
exposure pathways from open tank storage, there were no potential risk 
pathways that need to be modeled. EPA found that risks from air 
releases from the open tank storage scenario presented insignificant 
risk.
    Moreover, this residual will frequently exhibit the characteristic 
of corrosivity (i.e., pH will be above 12.5) and toxicity due to cresol 
leachability (and sometimes ignitability) and is subject to all 
applicable regulatory controls when any of the hazardous waste 
characteristics are present.

Discussion

    The Agency proposed not to list this waste as hazardous and has 
found no reason to change this decision after consideration of public 
comments and all other information available in the rulemaking record. 
EPA's 3007 Questionnaire showed that 51 percent of the waste stream is 
reused as an ingredient or substitute for virgin caustic and, is thus 
eligible for exclusion from the definition of solid waste under 40 CFR 
261.2(e). The exclusion provides that secondary materials that are used 
or reused directly (i.e., without reclamation) are

[[Page 42159]]

not subject to regulation under RCRA and are therefore not subject to 
any listing determination. In addition, the proposal noted that 
characteristically hazardous spent materials that are reclaimed prior 
to reuse would still be hazardous wastes subject to pertinent 
management requirements. Therefore, as noted in the proposal and 
confirmed in this final decision, there is no reason to cover this 
portion of the waste stream in the listing.
    In addition, 17 percent of the spent liquid treating caustics are 
used as valuable commercial feedstocks in the manufacture of cresylic 
or naphthenic acids. Accordingly, EPA in today's final rule, for 
reasons stated in the preamble to the proposed rule at 60 FR 57769-
57770, is amending 40 CFR 261.4(a)(19) to clarify that spent caustics 
used in this manner are not solid wastes and, therefore, should not be 
subject to listing.
    For the 29 percent of the wastes sent to wastewater treatment 
systems, EPA's analysis in the proposed rule found that risks from this 
practice are unlikely. As noted in the proposed rule, risks from such 
treatment are unlikely to be of concern because: (1) Treatment is 
already regulated under Federal water (NPDES) and air (benzene National 
Emissions Standards for Hazardous Air Pollutants (NESHAP), Maximum Air 
Control Technology (MACT) standards) programs; (2) sludges generated 
from wastewater treatment are already regulated as hazardous waste 
(i.e., K048, K051, F037, F038); (3) volumes of the discharged residuals 
under evaluation are relatively small in comparison to the volumes 
typically treated in wastewater systems; and (4) the wastewater 
treatment systems are designed to treat refinery wastes effectively 
(see discussion below).
    The Agency concluded that there were no potential risk pathways 
that needed to be modeled except air exposure pathways from open tank 
storage. For open tank storage, the Agency's bounding risk assessment 
estimates resulted in no significant risks (see 60 FR at 57770). In 
addition, this waste consistently exhibits the characteristic of 
corrosivity (and often toxicity due to cresols), and, therefore, could 
not be otherwise discarded without being subject to regulation as a 
hazardous waste.

Specific Comments

    In comments on the proposed rule, one commenter argued EPA only 
evaluated potential risks associated with tank storage, that EPA must 
evaluate the groundwater impacts from surface impoundment management, 
since that method of management is both an actual and plausible 
mismanagement scenario. The commenter stated that several refineries 
reported managing spent caustic in surface impoundments in 1992, and 
that the high-end volume of 596 MT managed in surface impoundments 
exceeds volumes EPA modeled for other waste practices. The commenter 
also noted that controls on surface impoundment risks by Phase III and 
Phase IV LDR rules cited by EPA in the proposal as being able to 
effectively regulate these wastes were not finalized.
    In response, EPA wishes to clarify a few points. First, in every 
case described in the 1992 database, these surface impoundments were 
part of the refineries' wastewater treatment systems. EPA has no data 
indicating that undiluted caustics were managed in surface 
impoundments. Therefore, to model this scenario appears unreasonable. 
Second, EPA did, in fact, conduct a screening analysis of the impact 
spent caustic would have on the wastewater treatment plant, as 
described in the docket to the proposed rule, but found that the 
dilution with other process wastewaters was so great that no impact was 
observed (see page 152 of the Listing Background Document, 1995). In 
further considering this scenario, EPA estimates that the 90th 
percentile quantity of spent caustic discharged to wastewater treatment 
in 1992 (approximately 4,000 MT) would be diluted by a factor of about 
3000. Thus, EPA does not believe that additional risk assessment is 
necessary. In addition, the constituents of concern (relatively low 
levels of certain volatile organics and metals, see the 1995 Listing 
Background Document for details) in these residuals are generally 
indistinguishable from those found in other residuals (many already 
listed as hazardous waste) typically discharged to wastewater 
treatment, making it virtually impossible to attribute any subsequent 
concentrations in sludges or environmental releases to the contribution 
from spent caustics. The combination of dilution and the expected 
toxicant removal and destruction that the wastewater treatment plants 
are designed to accomplish should effectively treat the spent caustic.
    In addition, the Agency continues to believe that significant 
regulatory control of any spent caustic-derived treatment sludges 
already exists. Sludges and other residuals from the initial oil/water/
solids separator are already regulated as K048 and K051. Sludges from 
oil/water/solids removal surface impoundments are also regulated as 
hazardous in the petroleum refining industry, through the F037/F038 
listings. Clearly, risks associated with biological treatment sludges 
and wastewaters downstream from these units are reduced as a result of 
the prior removal and treatment, including biodegradation. Further 
regulatory controls also exist for these sludges and wastewaters via 
the TC. In addition, the benzene NESHAP (58 FR 3072, January 7, 1993) 
and the planned air standards for volatile organics emissions (MACT 
standards proposed in 61 FR 17358, April 19, 1996) provide regulatory 
mechanisms for control of air emissions, and wastewater discharges are 
covered by the NPDES program.
    EPA does agree that it is no longer appropriate to rely on the 
regulatory controls originally anticipated via the Phase III and IV 
land disposal restrictions. The Land Disposal Program Flexibility Act 
of 1996 caused the Agency to withdraw the LDR Phase III treatment 
standards (see 61 FR 15660, April 8, 1996), and not to finalize the 
proposed LDR Phase IV provisions (see 62 FR 25997, May 12, 1997). 
However, as required under the Act, EPA is currently conducting a 5-
year study of surface impoundment usage, and if the study indicates 
that risks from impoundments are significant, EPA will then consider 
the need for further regulatory controls.
    One commenter noted that EPA's sampling indicates that spent 
caustic from liquid treating ``consistently exhibits'' a characteristic 
(the corrosivity characteristic, and TC for cresols and benzene), thus 
it should be listed as hazardous under EPA's listing criterion in 40 
CFR 261.11(a)(1). The commenter argued that current regulatory control 
depends upon whether the particular waste exhibits a characteristic (a 
determination the generator can reach based solely upon his or her 
``knowledge'' of the waste).
    EPA agrees that this residual frequently and typically exhibits one 
or more of the characteristics. However, because the majority of 
caustic management practices are either exempt from regulatory control 
or are adequately regulated under other regulations (e.g., the 
characteristics), the Agency believes that listing as hazardous waste 
is not necessary. In response to the commenter's concern regarding 
knowledge that this residual exhibits a characteristic, EPA notes that 
this material is commonly acknowledged as corrosive due to its highly 
caustic nature (hence its name), and managed in a manner to minimize 
corrosion problems during storage. Thus, the Agency believes that 
generators of spent caustic are well

[[Page 42160]]

aware of the potential for this residual to exhibit hazardous waste 
characteristics, and manage their spent caustic accordingly. Given the 
existing regulatory controls and management practices for this waste, 
EPA continues to believe that listing is not warranted.
    Several commenters believed that the use of caustics in the 
manufacture of cresylic acid and naphthenic acid has always been 
excluded from the definition of solid waste under 40 CFR 261.2(e)(1)(I) 
and that a promulgation of the proposed specific exclusion might 
indicate that up until now, these caustics have not been excluded. 
Thus, the commenters requested clarification.
    In response, EPA notes that the Agency and several states have been 
involved in a longstanding discussion with industry regarding the 
regulatory status of these materials. The promulgation of this rule 
presents EPA's final findings, and is intended to put an end to 
discussions regarding possible ambiguities in the current rules. The 
purpose is to settle this matter once and for all, and we are doing so 
by providing a clear regulatory exclusion.
6. Off-Specification Product and Fines From Thermal Processes Summary
    EPA is not listing as hazardous off-specification product and fines 
from thermal processes. No risks of concern were identified for those 
materials that actually are discarded. Most of the materials generated 
from these thermal processes are coke product and are stored in piles 
with other coke product before they are resold. These piles are not, 
therefore, subject to RCRA jurisdiction or they are exempt from RCRA 
regulations.

Discussion

    The Agency proposed not to list these materials, which are 
generated from various refinery coking operations. Of the 194,300 MT of 
these materials generated, approximately 87 percent is collected and 
combined with product inventory to be sold. However, more than 7,250 
tons (3.7 percent) are landfilled in on-site or off-site Subtitle D 
landfills. These discarded materials were the wastes on which the 
Agency conducted its risk assessment.
    EPA determined that other management practices, including fines 
sent to wastewater treatment, would not serve as a basis for listing 
and adopts the reasoning in the proposal for this determination as part 
of its final decision. (See 60 FR at 57770-57771). In summary, fines 
sent to wastewater treatment are insoluble and will be incorporated in 
primary treatment sludges that are already listed as K-and F-wastes; 
LTUs received very small waste volumes; and other management practices 
do not actually isolate the materials from the coking process and, 
thus, are not wastes.
    Commenters questioned why EPA did not assess risks from coke fines 
placed on piles of coke product, arguing that the waste does not become 
a product simply because it is placed on the pile and combined with 
another material. In the NODA, EPA provided further clarification on 
the jurisdictional basis for not evaluating the majority of off-
specification product and fines that are managed as coke product. The 
Agency explained that only particle size distinguishes coke fines from 
other coke product. The majority of coke is removed from the coker by 
hydraulic drilling and coke fines are merely the smaller pieces of coke 
generated during this process.
    In addition, EPA explained there is a jurisdictional distinction 
between coke fines produced from non-hazardous materials and coke fines 
produced from hazardous wastes (waste-derived fines).24 
Fines generated from non-hazardous materials are simply coke product, 
as would be expected because they are produced from the same coking 
drum. In the case of waste-derived fines, so long as the fines are 
legitimate coke product, they are exempt from RCRA regulation unless 
the material exhibits a characteristic as provided in 40 CFR 
261.6(a)(3)(v). (See also RCRA section 3004(q)(2)(A)). EPA had no 
information that waste-derived coke fails any hazardous waste 
characteristic. The Agency invited comment or data to the contrary but 
received none.
---------------------------------------------------------------------------

    \24\ See the discussion on oil-bearing hazardous secondary 
materials inserted into the petroleum refining process, including 
the coke, in today's preamble for modifications to the definition of 
solid waste concerning these materials.
---------------------------------------------------------------------------

    In any event, EPA determined that the use of hazardous waste in the 
production of coke would result in little, if any, change to the 
qualities and the properties of the coke and fines produced. These coke 
fines would have essentially the same composition as fines generated 
from non-hazardous feed materials. The waste-derived fines are combined 
with other coke in a product pile for storage prior to sales and are 
coke product. The NODA also provided additional analyses on the 
similarity of coke fines to existing coke product, and the potential 
impact of recycling hazardous waste to the coker.
    EPA has no reason to change this jurisdictional determination or 
the determination that management scenarios other than Subtitle D 
landfilling could not serve as a basis for listing. Therefore, the 
Agency adopts these determinations as part of the basis for issuing the 
final decision not to list this waste stream as hazardous.
    With respect to the Subtitle D landfilling scenarios EPA evaluated 
for the off-specification product and coke fines that were discarded, 
EPA notes that groundwater risk estimate of 1E-5, as well as the 
revised high-end risks in the NODA of 5E-6 to 2E-5 were within the 
Agency's initial risk level of concern.
    However, EPA noted significant problems with the groundwater risk 
assessments. First, this risk was based entirely on the detection of 
one PAH, benzo(a)anthracene, in only one out of six leaching samples at 
a level 8-fold below the analytical quantification limit. Thus, EPA had 
low confidence in this value and the subsequent modeling based on this 
number. Second, the water solubility of this chemical is also very low, 
indicating that its aqueous concentration is likely to be very low. 
Third, this chemical is tightly adsorbed to organic material in soils 
and sediment, indicating that the constituent is relatively immobile in 
groundwater.
    The NODA analysis, therefore, led EPA to determine that it is 
highly unlikely that this waste would present a significant risk in a 
groundwater scenario. EPA finds no reason to change that determination 
either based on NODA comments or any other information in the 
rulemaking record. In addition, further assessments in the NODA showed 
no significant risks from the relatively small volumes that were 
disposed in LTUs.
    EPA's decision not to list is further supported by additional 
analysis after comments received on the NODA. In its reexamination of 
the groundwater analysis EPA found that it had mistakenly used the 
wrong carcinogenic risk factor for benzo(a)anthracene. As shown in 
Table IV-2, when the revised groundwater analysis was performed with 
the longer active life and municipal landfill areas, using the correct 
health-based number caused the risks to drop 20-fold, such that even 
the maximum high-end risk was 2E-6. See Additional Groundwater Pathway 
Analyses, 1998, contained in the public docket for this rule for 
details. Given the even lower groundwater risk calculated, still using 
the suspect benzo(a)anthracene measurement, EPA finds even further 
reason to believe that the listing of off-specification product and 
fines is not warranted.

Specific Comments

    One commenter claimed EPA data indicates that several respondents 
store

[[Page 42161]]

off-specification products and fines in surface impoundments as an 
``interim'' management method, and therefore the Agency should model 
this management. In response, EPA finds only one respondent, not 
several, that reported managing off-specification product and fines in 
a ``surface impoundment'' in 1992. This ``surface impoundment'' acts as 
a drilling water clarifier. All delayed coking units recycle their 
drilling water, and to do so, any entrained fines in the drilling water 
must be recovered. Typically, the concrete coke storage pad is sloped 
so that drilling water drains to one end and proceeds through a series 
of baffles that separate out the coke fines. This is the type of 
``surface impoundment'' the refinery identified. Thus it is not a 
typical surface impoundment, but rather an integral part of the 
decoking process. These are lined (concrete) drilling water collection 
and recycle systems, confined within the coke battery, and are unlikely 
to pose significant risk.
    Comments related to the aspects of the groundwater modeling are 
discussed earlier in this notice (see Section V.B.6); however, EPA 
makes several points for this specific wastes. Regarding the 
commenters' criticism of EPA's use of TCLP results as input values to 
the landfill groundwater modeling for this material because it is 
``oily,'' the Agency points out that off-specification product and 
fines are generally not oily. The Agency conducted total oil and grease 
analyses on four samples and the average level of oil and grease 
(measured as Total Oil and Grease, i.e., not truly ``free'' oil) was 
two percent (three samples were below one percent). Furthermore, the 
data from the 3007 Questionnaire show that the typical material has 
relatively low oil content (90th percentile value was five percent). 
Therefore, EPA believes that the use of the TCLP was valid.
    With regard to commenter concern over free-phase flow of 
contaminants from off-specification product and fines due to oil 
content, it is particularly important to note that none of the six off-
specification product and fines from thermal processes samples 
exhibited multi-phase behavior, and that the measured oil content was 
low, as noted above.
    The commenter went on to state that a risk assessment EPA conducted 
for this waste as part of the 1995 proposal showed that risks 
associated with air releases from uncovered landfills made up of coke 
fines exceeded 1E-3 for home gardeners, subsistence farmers, and 
subsistence fishers, and a high risk to subsistence fishers from 
mercury exposure was also predicted. The commenter also noted that the 
NODA risk modeling for disposal in LTUs was not a meaningful surrogate 
for evaluating the risks posed by pile storage, because the annual 
volumes modeled were small (high-end volumes of 21-34 MT).
    The commenter is attempting to use a bounding analysis EPA 
undertook for nongroundwater risks for coke fines disposed in landfills 
as an indication that air releases from piles containing this material 
would present similar risks. In response, EPA first notes that bounding 
estimates are used as an initial screening estimate that overestimates 
the exposure or dose for the purpose of screening out exposures of 
little concern. The purpose of the bounding analysis is simply to 
determine what pathways and scenarios require further evaluation and 
does not represent an assessment of risks. The bounding analysis 
included worst-case assumptions (no cover or dust suppression, highest 
constituent levels, largest waste volumes and landfill area, worst 
climate, etc). Furthermore, the levels near 1E-3 arose from indirect 
pathways (ingestion of beef, dairy, fish, and plant products); the 
direct pathway of soil ingestion, even in the bounding analysis, was on 
the order of 1E-6. Most importantly, the biotransfer factors used in 
the bounding analysis for beef, dairy, and plant indirect paths have 
been determined to overestimate risks by at least two orders of 
magnitude; likewise the apparent problem from mercury also was traced 
to an error in units for the bioaccumulation factor used. Thus, EPA 
believes that the bounding analysis was flawed and grossly 
overestimated risks.
    EPA notes that the subsequent high-end analyses for nongroundwater 
risks from landfill disposal of off-spec product and fines did not show 
significant risk. While the high-end analysis included the assumption 
of daily cover for the landfill, and thus may not be the best surrogate 
for air releases from piles, the scenario did consider windblown dust 
from on-site roads and particulate release caused by traffic (i.e., 
dump trucks), loading, unloading, etc. The high-end analysis showed 
risks no higher than 2x10-6 for any receptor (see U.S. EPA, Assessment 
of Risks from the Management of Petroleum Refining Wastes Background 
Document (F-95-PRLP-S0006), page 10-3). Therefore, some of the possible 
release mechanisms that could occur in a waste pile scenario (e.g., 
unloading/loading, traffic) were addressed in the risk assessment 
supporting the proposal and the pathway was not significant.
    EPA also points out that some important characteristics of the coke 
pile and details of management practices used by refineries would tend 
to mitigate potential risks. The piles are not comprised simply of coke 
fines, but are mixtures of much larger pieces of coke product that are 
drilled from coker units; the larger chunks of coke would make up the 
bulk of the pile. Furthermore, coke is drilled out of the coker 
approximately once a day with hydraulic drills; thus, new wet coke/
fines from drilling are added to the coke pile, making air releases of 
dry particulates less likely. EPA also has found that coke piles are 
managed using various practices to control release of dust, including: 
(a) Contained product storage areas (b) dust-suppression water spray 
systems (c) covered conveyor systems and, (d) direct loading from coke-
drums into railcars (see NODA response to comment document for a 
summary of these practices). In addition, EPA expects that particulate 
releases from these areas would be controlled by Federal, State, or 
local air regulations and permit programs.
    Finally, the commenter also argued that, pursuant to the Consent 
Decree in EDF v. Browner, EPA is required to issue a listing 
determination for off-specification products and fines, and that 
because piles present a substantial risk to human health and the 
environment based upon the assessments conducted to date, the required 
listing determination must include a decision as to whether off-spec 
products and fines warrants listing pursuant to 40 CFR 261.33 as a 
commercial chemical product. The commenter suggested that, if EPA 
argues that the piles of coke fines are product, then the material that 
blows off the piles and cannot be recovered is discarded commercial 
chemical product and should become a listed U-waste under 40 CFR 
261.33(f).
    EPA disagrees with the commenter. The Agency has, in fact, made a 
listing decision for the off-specification product and fines that are 
known to be discarded by refineries, i.e., the volumes of wastes that 
are disposed. EPA believes it has fulfilled the requirements of the 
consent decree for production wastes from petroleum refining. While the 
Agency is not constrained to making decisions required under the 
consent decree, EPA is not making a listing decision on product use in 
this rulemaking. Furthermore, at this time the Agency has no valid 
assessment that indicates these wastes present a ``substantial risk'' 
when added to coke piles.

[[Page 42162]]

7. Catalyst and Fines From Catalytic Cracking

Summary

    As proposed, EPA is not listing as hazardous Fluidized Catalytic 
Cracking (FCC) catalyst and fines. Two subcategories of this waste were 
evaluated due to their physical difference in particle size: spent 
equilibrium catalyst and catalyst fines. The usual constituents of 
concern found in other petroleum residuals (i.e., carcinogenic PAHs and 
benzene) were not detected in spent FCC catalysts. More than 70 percent 
of the equilibrium catalyst and 20 percent of the catalyst fines are 
reused (in other FCC units) or recycled (primarily by cement plants). 
For the reasons stated in the proposal, the Agency chose to model the 
monofill and surface impoundment scenarios (see 60 FR at 57771) for FCC 
catalyst and FCC fines. Bounding estimates (run under worst-case 
assumptions using multiple high-end assumptions for critical 
parameters) for the nongroundwater exposures from volatile and 
particulate emissions from monofills showed no significant risk for 
either FCC equilibrium catalyst or FCC fines. The Agency also found no 
significant risk, for either subcategory, from the high-end analysis 
for the groundwater pathway from the monofill or surface impoundment 
scenarios. Furthermore, the revised risk analyses in the NODA in 
response to comments showed no significant risks for this waste. The 
few comments EPA received on this waste agreed with EPA's decision not 
to list. Therefore, the Agency continues to believe that a no-list 
decision is warranted and adopts that final decision incorporating the 
reasoning in the preamble to the proposal.
8. HF Alkylation Sludge

Summary

    The Agency is not listing as hazardous sludge from hydrofluoric 
acid (HF) alkylation processes. As noted in the proposal and confirmed 
by analysis of comments and all other relevant information in the 
record, only marginal risk was identified for the groundwater ingestion 
pathway in off-site landfilling due to benzene. Also, no significant 
risks were found from land treatment of this material.

Discussion

    In the proposal, EPA found a high-end groundwater risk for 
landfills of 3E-6 due to benzene (see 60 FR at 57772). The Agency also 
noted that benzene was found in only one out of five TCLP samples, 
indicating that the risk attributed to this chemical would generally be 
lower. EPA did not model other waste management practices because they 
were already regulated under RCRA (e.g., combustion in a industrial 
furnace), extremely rare (discharge to a surface impoundment that has 
been closed), recycling practices (on-site recovery), and/or would 
present no significant risk (discharge of small volumes to wastewater 
treatment systems).
    In the NODA, the Agency revised the groundwater risk analysis for 
landfill disposal and found slightly higher high-end risks for 
groundwater for off-site and on-site landfills (both 6E-6) due to 
benzene. EPA also presented a groundwater Monte Carlo analysis in the 
NODA that showed risks of 2E-7 for on-site, and 2E-6 for off-site 
landfills. Revised nongroundwater risks from disposal in LTUs remained 
insignificant (less than 1E-7; see 62 FR at 16753).
    Further groundwater pathway analysis performed in response to 
comments on the NODA showed a slight increase in the high-end risk to 
1E-5 for off-site landfills. The revised Monte Carlo analysis yielded 
no change in the risk (2E-6). (See Table IV-2, and Additional 
Groundwater Pathway Analyses, 1998, contained in the public docket for 
this rule).
    EPA decided not to list this waste based on the relatively low 
groundwater high-end risks of 1E-5 due solely to benzene, and the fact 
that benzene is not frequently found in the TCLP analysis (one of five 
samples). Furthermore, this waste typically does not have high oil or 
PAH content; none of the carcinogenic PAHs were detected in the samples 
collected by EPA. Therefore, the Agency is issuing a final decision not 
to list this waste stream.

Specific Comments

    The Agency received comments arguing that sludges from HF 
alkylation are frequently generated and managed in surface impoundments 
and were not evaluated by EPA because it is a ``rare'' management 
practice. The commenter stated that there are an ample number of 
surface impoundments at refineries that could be used in this manner, 
there is no legal or other barrier to surface impoundment management of 
HF alkylation sludge, and that this practice should be considered a 
plausible management scenario. The commenter noted that the waste is 
sometimes generated in ``pits,'' and this means management in an 
impoundment is a reasonable assumption.
    EPA disagrees with the comment that HF sludge is commonly generated 
or managed in surface impoundments. From site visits, EPA found that HF 
alkylation sludge is commonly generated in concrete lined pits or tanks 
within the HF process unit boundary; these are not unlined surface 
impoundments. The one case of actual management of this waste in a 
surface impoundment in 1992 was reported to be discontinued that year 
(see Listing Background Document, October, 1995). Therefore, EPA does 
not believe management in surface impoundments is plausible.
    One commenter criticized EPA's modeling of risks from LTUs, and 
these are addressed elsewhere in today's notice (see Section V.B.7). 
However, EPA would like to note that nongroundwater risks are unlikely 
to be significant for this waste because HF alkylation sludge has none 
of the carcinogenic PAHs that were of concern for other wastes. For 
example, while CSO sediment samples had an average of 132 ppm of the 
PAH benzo(a)pyrene, none was detected in any sample of HF alkylation 
sludge.
    One commenter argued that EPA should list this waste based on the 
groundwater risks estimated by EPA, as well as the risk calculated by 
the commenter using alternative groundwater modeling (2E-5). EPA 
disagrees with the commenter, and continues to believe the risks do not 
justify listing this waste. As noted in the discussion above, EPA's 
revised high-end risk was 1E-5, and the revised Monte Carlo risk only 
2E-6. EPA has decided not to list this waste after considering other 
factors. Most importantly, the risk was due to the presence of one 
constituent, benzene, that was detected in only one of the five TCLP 
samples. Thus, the constituent was not found frequently or typically in 
this waste. Furthermore, EPA found none of the carcinogenic PAHs in 
samples of this waste that were so pronounced in other wastes of 
concern (e.g., CSO sediment).
9. Sludge From Sulfur Complex and Hydrogen Sulfide Removal Facilities

Summary

    As proposed, the Agency is not listing as hazardous sludge from 
sulfur complex and hydrogen sulfide removal facilities. No significant 
risks were found for any exposure pathway from disposal in on-site or 
off-site landfills, or in on-site and off-site LTUs, nor from potential 
air releases from storage in dumpsters (well below 1E-6 in all cases). 
In addition, the Agency noted that the sludges that may be generated 
from treatment of this waste in the

[[Page 42163]]

primary wastewater treatment system are already listed. Furthermore, 
the revised high-end risk analyses in the NODA in response to comments 
also showed no significant risks for this waste (well below 1E-6 in all 
cases). The few comments EPA received on this waste agreed with EPA's 
decision not to list. Therefore, the Agency continues to believe that a 
no-list decision is warranted and adopts the final decision 
incorporating the reasoning in the preamble to the proposal.
10. Catalyst From Sulfur Complex and Hydrogen Sulfide Removal 
Facilities

Summary

    The Agency is not listing as hazardous any of the spent catalysts 
generated from H2S removal and sulfur complex operations. 
The Agency divided this residual into two subcategories: Spent Claus 
unit catalyst, and spent SCOT-like tail gas catalyst. For the first 
subcategory, no significant risks were found from bounding estimates 
(run under worst-case assumptions using multiple high-end assumptions 
for critical parameters) for the groundwater exposure pathway as well 
as for the direct and indirect pathways of volatile emissions and 
particulate emissions. For the second subcategory, the Agency also did 
not find significant risks associated with the disposal of this waste 
in on-site and off-site landfills. Furthermore, the revised risk 
analyses in the NODA in response to comments continued to show no 
significant risks for this waste stream. Therefore, the Agency 
continues to believe that a no-list decision is warranted and adopts 
the final decision incorporating the reasoning in the preamble to the 
proposal.
11. Unleaded Gasoline Storage Tank Sediment

Summary

    EPA is not listing as hazardous sediment from the storage of 
unleaded gasoline in tanks. The Agency assessed the potential risks 
associated with four selected management practices, on-site and off-
site Subtitle D landfilling, and on-site and off-site land treatment. 
Only marginal risk was identified for the groundwater ingestion 
exposure pathway. Although revisions to the risk assessment showed 
higher risks above the level of concern, EPA has still decided not to 
list this waste because: (1) The waste is primarily rust and scale and 
has none of the carcinogenic PAHs or high oil content of potential 
concern in other wastes, (2) the TC is expected to control some risks, 
(3) the volume of waste is relatively small, and (4) the reduction of 
benzene levels in reformulated gasoline should reduce levels in wastes 
in the future.

Discussion

    EPA proposed not to list unleaded gasoline tank sediment as 
hazardous due to the absence of any significant risks, except for the 
marginal risks found for the groundwater ingestion pathway for off-site 
landfill disposal (high-end risk, 2E-6). The Agency also noted that 
this waste was infrequently generated, volumes of this waste disposed 
were relatively modest, and that the only constituent of concern, 
benzene, would be controlled by the TC.
    The revised modeling completed by EPA in response to comments on 
the proposal and the NODA included a full sensitivity analysis to 
determine the most critical high-end parameters, and resulted in off-
site landfill groundwater risks increasing to 3E-5 (see Table IV-2). 
The high-end risk was lowered slightly to 2E-5 in the TC-capped 
results. However, the revised Monte Carlo risk, 6E-6, is below EPA's 
level of concern (1E-5), and the TC-capped Monte Carlo risks drop to 
4E-6, suggesting the TC may control most risks of concern for this 
waste. After considering these risk results, and the other factors 
discussed below, EPA finds that the listing of this waste is not 
warranted.
    First, while the levels of benzene in the waste and TCLP samples 
are of potential concern, the TC for benzene should provide some 
measure of control of wastes with high benzene levels. Nearly 40 
percent (52) of the 141 unleaded gasoline tank sediment wastes streams 
generated in 1992 were reported in the 3007 Questionnaire to be coded 
as hazardous waste (due primarily to the TC for benzene and 
occasionally for ignitability). While EPA's risk analysis using TCLP 
input data capped at the TC level still showed some risk (2E-5), many 
of the wastes that are not TC-hazardous will likely have benzene levels 
below the TC level. Thus, given the existing regulatory control 
afforded by the TC, the incremental benefit to listing this waste 
appears limited.
    Furthermore, this waste does not have the features that EPA found 
compelling in deciding to list other wastes examined in this rule. 
Specifically, this waste lacks the pyrophoricity and arsenic concerns 
exhibited by the spent catalysts, and it has low oil content and PAH 
levels compared to the crude oil and CSO tank sediments. The oil 
content of this waste is typically low as evidenced by the median TOG 
levels reported in the 3007 Questionnaire (6 percent), and samples 
taken by EPA (<1 percent). This contrasts with much higher TOG levels 
in Crude Oil Storage Tank Sediment (34 percent average from the 3007 
Questionnaire, and 21 percent average from the six samples EPA 
analyzed) and CSO Tank Sediment (30 percent average from the 3007 
Questionnaire, and 37 percent average from EPA's samples). EPA's 
analyses of samples of unleaded gasoline storage tank sediments also 
showed none of the carcinogenic PAHs that were of concern in sediment 
from CSO and crude oil tanks. For example, average benzo(a)pyrene 
levels found in sediment from CSO and crude oil storage were 132 ppm 
and 12 respectively, but none was found in sediment from unleaded 
gasoline storage. In addition, one of the major constituents measured 
in the unleaded gasoline tank sediment was iron (e.g., the average iron 
level for the three samples was 41, thus this waste appears to be 
largely rust and scale, rather than the higher organic content of the 
other tank sediments. Therefore, EPA is more confident that the other 
constituents of gasoline tank sediment will not present any potential 
problem.
    Also, as noted in the proposed rule, the total volume of the waste 
reported for 1992 is relatively small (3,583 MT), and the volumes sent 
to landfills are even smaller (633 MT, 22 MT average per waste stream). 
These volumes are significantly smaller than the volumes of crude oil 
storage tank sediment generated (22,017 MT) and sent to landfills 
(2,338 MT, 123 MT average).
    Finally, EPA has promulgated regulations under the Clean Air Act 
(CAA) that will result in the reduction of benzene levels in gasoline 
(see the Reformulated Gasoline Rule, February 16, 1994; 59 FR 7716). 
This rule sets a 1.0 percent (by volume) benzene limit on reformulated 
gasoline for non-attainment areas of the United States. In conventional 
gasoline, benzene is incorporated into gasoline to increase the octane 
rating, and the average amount of benzene in conventional gasoline is 
1.6 percent, ranging up to 5.0 percent. Therefore, as the levels of 
benzene in gasoline are reduced, sediment from storage of gasoline 
should also show a corresponding reduction in the levels of benzene. 
This will reduce the potential groundwater risks resulting from benzene 
in unleaded gasoline storage tank sediment.

Specific Comments

    One commenter noted that EPA did not model the use of unleaded 
gasoline tank sediment waste as landfill cover or road spreading. In 
response, the Agency

[[Page 42164]]

points out that no refineries reported use of unleaded gasoline tank 
sediment as landfill cover or in road spreading. The Agency has no data 
supporting these management scenarios and therefore does not see the 
need to model this pathway.
    While the Agency already discussed the general issues related to 
the appropriateness of the TCLP for the wastes examined in this 
rulemaking due to oil content, EPA notes that for this specific waste 
the total oil and grease levels in the available samples collected by 
EPA were well below 1 percent. Thus, the commenter's concern about 
problems with the TCLP and oily waste are clearly unfounded for this 
waste.
    One commenter criticized EPA's modeling of risks from LTUs, and 
these are addressed elsewhere in today's notice (see Section V.B.7). 
However, EPA would like to note that nongroundwater risks are unlikely 
to be significant for this waste under any scenario because unleaded 
gasoline tank sediment has none of the carcinogenic PAHs that were of 
concern for other wastes, such as CSO.
    One commenter argued that EPA should list this waste based on the 
groundwater risks calculated by the commenter using alternative 
groundwater modeling (8.8E-5). EPA disagrees with many of the 
commenter's suggested modifications to the modeling (see Section V.B.6) 
and continues to believe that the risks do not justify listing this 
waste. As noted in the discussion above, EPA's revised high-end risk 
was 3E-5, and the revised Monte Carlo risk was 6E-6 (see Table IV-2), 
and after considering the other factors noted, EPA has decided not to 
list this waste. Furthermore, the revised Monte Carlo risks for this 
waste were 6E-6, below EPA's 1E-5 level of concern. In addition, the 
Monte Carlo TC-capped risk of 2E-6 suggests that the TC will be 
effective in controlling much of the risk for this waste.
12. Catalyst From Reforming

Summary

    The Agency is not listing as hazardous spent catalyst from 
reforming operations, as proposed. The proposal noted that 94 percent 
of the wastes generated in 1992 were recycled at reclamation facilities 
for the precious platinum content. The remaining 6 percent consist 
primarily of other materials generated during catalyst replacement, 
e.g., ceramic support media that are inert. The Agency conducted risk 
analysis of the potential air exposure pathway from the combustion of 
the reforming catalyst prior to reclamation, and no significant risk 
was found from this pathway. In addition, the Agency believes generator 
site environmental release other than potential de minimis spills would 
be unlikely because the valuable spent reforming catalysts are 
controlled and tracked between the refining and reclamation facilities 
to prevent loss. The one comment EPA received on the Agency's 
assessment agreed with the decision not to list. Therefore, the Agency 
continues to believe that a no-list decision is warranted and adopts 
the final decision incorporating the reasoning in the preamble to the 
proposal.
13. Sludge From Sulfuric Acid Alkylation
    The Agency is not listing as hazardous sludge from sulfuric acid 
alkylation. In the proposal, the Agency noted that this waste was 
infrequently generated, and the volumes generated in 1992 were very 
small (608 MT). Based on the bounding estimates (run under worst-case 
assumptions using multiple high-end assumptions for critical 
parameters) conducted for land treatment and landfilling practices, no 
significant risk was found. Furthermore, the revised land treatment 
risk analyses in the NODA in response to comments showed no significant 
risks for this waste stream. Therefore, the Agency continues to believe 
that a no-list decision is warranted and adopts the final decision 
incorporating the reasoning in the preamble to the proposal.

D. Headworks Exemption

    As noted in Section III.A in the proposed rule, EPA proposed to 
extend the existing exemption for wastewaters from cleaning of 
petroleum tanks to include those generated for CSO tank sediment, and 
if listed, crude oil storage tank sediment. In the NODA, EPA proposed 
to extend the exemption to include wastewaters generated from the clean 
out of processing units holding spent hydrotreating and hydrorefining 
catalysts.
1. Application to Listed Catalysts
    Many commenters requested clarification that the headworks 
exemption would include wastewaters from spent hydrotreating and 
hydrorefining catalysts. This would allow refiners to continue the 
practice of using water to cool and wash out these spent catalysts from 
the process units prior to further management. One commenter stated 
that sufficient controls are in place within refineries to manage minor 
residuals that are drained to the refinery sewer systems. These 
residuals will be removed in the system and become listed hazardous 
wastes. Without these exemptions, refiners would be forced to either 
use more costly or more dangerous methods in managing catalyst or be 
forced to collect and ship these wash waters off-site.
    As described in the NODA, EPA considered the commenters' request 
and conducted an assessment to determine the appropriateness of 
expanding the headworks exemption. The results of this analysis show 
that little risk is likely to be incurred by this practice. The use of 
water during the catalyst changeout process provides a number of 
benefits, including lowering emissions of volatile organics (if the 
wash water is treated to remove volatiles prior to discharge to the 
sewer system), lowering the risks associated with the catalysts' 
potential self-heating nature, and minimizing risk to workers entering 
the confined space of the catalytic reactors during changeouts. 
Therefore, EPA, has concluded that it is appropriate to include this 
low risk, beneficial practice under the headworks exemption.
    Many commenters approved of expanding the proposed headworks 
exemption to cover water associated with catalyst management. These 
commenters saw the exemption as consistent with EPA's listing criteria 
in 40 CFR 261.11(a)(3), and agreed with EPA that the exposure pathways 
from wastewater management associated with CSO sediment and 
hydroprocessing catalysts in the refinery wastewater treatment system 
are sufficiently regulated under the Clean Water Act (CWA), the CAA 
NESHAP, and the existing RCRA hazardous waste listing for refinery 
wastewater treatment sludges (K048, K051, F037, and F038).
    EPA agrees that existing NESHAP and effluent guideline controls on 
these materials, as well as the existing sludge listings (F037, F038, 
K048, K051), and the inherent differences between the wastes modeled 
and the aqueous residuals generated during tank and unit washings, 
support EPA's decision to finalize the headworks exemption.
2. Clarification of Scope
    EPA received a request for clarification about whether the proposed 
exemption is limited to dilute wastewaters resulting from the cleanout 
of tanks or other units containing these wastes, or whether the 
proposed exemption applies to the listed waste (sediment) itself. One 
commenter stated that the exemption would be abused and would encourage 
wholesale discharge of the sediments to the wastewater treatment 
system. EPA

[[Page 42165]]

reiterates that the headworks exclusion is not meant to serve as an 
incentive to discharge tank sediments (or spent catalyst) to the 
wastewater treatment plant. This was not the Agency's intent, and EPA 
requested comment in the NODA on how to ensure that the headworks 
exemption is not a loophole to dump catalyst or CSO sediment in the 
sewer.
    One commenter argued that the exemption would not be a loophole for 
two important reasons. First there would be a significant economic 
penalty for this action, because solid material dumped in the sewer 
will emerge again as hazardous waste sludges upstream of biological 
treatment (F037, F038, K051 and K048). The commenter stated that any 
wastewater sludge that these solids generate would likely be many times 
the original weight of the solids in the water (up to 10-fold due to 
the oil water-bacteria emulsion that forms around these solids). The 
commenter claimed that the increased costs associated with increased 
volumes of difficult to manage emulsions would be a severe economic 
penalty for allowing excess solids into a sewer. Secondly, the 
commenter noted that sewers are critical to a refinery's operation, 
such that any discharge of solids into a sewer runs the risk of 
interrupting refinery operations (with heavy costs), or at least 
overloading the system with solids, endangering compliance with water 
discharge permits. Therefore, the commenter concluded there is no need 
for EPA to further define allowable wastewater solids content, and this 
would only create unneeded analytical, record keeping, and related 
compliance burdens.
    The Agency agrees with this commenter that there are financial 
disincentives to discharging excess solids to the refinery wastewater 
treatment system. Furthermore, the Agency observes that many refineries 
conduct deoiling of tank contents and sediments prior to disposal and 
tank inspection. This practice reduces sediment quantities by an 
average of 40 percent, with a substantial savings of raw materials 
(i.e., oil recycled back to the refining operations) and disposal 
costs. Upon promulgation of today's listings and the exclusion for oil-
bearing residuals, EPA believes even greater amounts are likely to be 
subjected to oil recovery and waste minimization. Any water in the tank 
clean out material will likely be separated as a part of the deoiling 
process, and would be discharged to the wastewater treatment plant. 
Thus, with respect to some commenters' concerns regarding impacts on 
the wastewater treatment system, these recycling activities will likely 
increase and further reduce the load on the treatment system.
    A commenter asked EPA to clarify the scope of the exemption in the 
final rule, since water is used in any number of different ways in the 
proper handling of CSO sediment and spent hydroprocessing catalysts. 
They stated that EPA should clarify in the final rule that the 
exemption extends to all wastewaters derived from the management of the 
residuals, as long as the wastewaters are managed in a system subject 
to the Clean Water Act.
    EPA is aware of the following uses of water associated with the 
generation of K169 to K172. In reference to crude oil storage and CSO 
tank sediments (K169 and K170), wastewater is generated (1) by 
dewatering (e.g., centrifuging) sediment removed from the tank, and (2) 
by conducting a ``rinse'' as mentioned by the commenter. In reference 
to K171 and K172, wastewater is generated from drilling out the 
catalyst, steam stripping or washing, and pad drainage.
    EPA believes that the headworks exemption is appropriate for waters 
generated from all of these practices, because these aqueous residuals 
would be dilute and contain low levels of the original listed wastes. 
Therefore, the Agency is finalizing the exemption for all the wastes 
that are being listed: CSO sediment, crude oil sediment, spent 
hydrotreating catalysts, and spent hydrorefining catalysts. As noted in 
the proposal, however, the exemption is not intended to allow the 
discharge of the entire waste stream (i.e., tank sediments or spent 
catalysts), but rather dilute waters generated during tank or unit 
clean outs and dewatering.
    Another commenter requested clarification that the headworks 
exemption extends to zero discharge facilities that have CWA equivalent 
wastewater treatment units. The Agency wishes to clarify that the 
exemption would extend to facilities subject to regulation under 
section 402 or section 307(b) of the CWA and would include facilities 
that have eliminated the discharge of wastewater. However, this 
clarification is already included in the regulations in 261.3(a)(iv) 
and specifies that wastewaters at facilities that have eliminated 
discharges are included.
    Facilities that elect to use the headworks exemption should 
understand the potential compliance implications for Subpart FF, the 
benzene waste operations NESHAP, (40 CFR 61.340). Subpart FF conditions 
the need for air pollution controls and waste treatment on the total 
annual benzene quantity (TAB) from a facility's waste. Facilities must 
include any waste stream ``that has a flow-weighted annual average 
water content greater than 10 percent or that is mixed with water or 
other wastes at any time and the mixture has an annual average water 
content greater than 10 percent.'' Since 1995, refineries with a TAB of 
10 MT per year or greater must treat all benzene wastes and control 
emissions from drains, sewers, tanks, oil-water separators, 
impoundments, and containers. Thus, if facilities elect to use the 
headworks exemption, any wastes put in sewers that did not previously 
count toward the TAB will have to be included in TAB calculations. If 
refineries have TAB that exceeds 10 MT/yr, they would be out of 
compliance with Subpart FF.
3. Comments Opposing the Exemption
    One commenter urged the rejection of EPA's proposal to exempt from 
regulation previously listed refinery wastes (K050), CSO residuals, and 
crude oil storage tank sediment, because it encourages waste 
constituent volatilization and dilution, rather than pollution 
prevention and responsible waste management. The commenter noted that 
EPA's sole justification for the proposal was the Agency's belief that 
the hazardous constituents in these wastes would wind up in RCRA 
regulated wastewater treatment sludges. The commenter asserted that EPA 
failed to address why hazardous constituents in the discharges would 
not be released into the air, or remain in the wastewater and bypass 
the primary sludge only to settle in the unregulated treatment sludges 
further down the treatment train.
    As noted earlier in today's notice (see discussion on Waste 
Management Assumptions in Section V.B.2), EPA does not believe that 
discharges to wastewater treatment systems are likely to present 
significant risks. EPA also notes it did not find air releases of 
volatiles, such as benzene, to be a significant risk for any of these 
wastes for any disposal practice evaluated. Thus, EPA does not believe 
that any air releases from a much more dilute waste generated during 
tank or unit clean outs are likely to present significant risk. The 
Agency notes that the benzene NESHAP (58 FR 3072; January 7, 1993) 
provides significant control of emissions from the wastewater 
conveyance system at larger refineries, and that the reported amount of 
sediments managed in this manner is small relative to the total volume 
of waste being given this exemption. Refineries also avoid overloads to 
their biological treatment trains in order to maintain their 
effectiveness.

[[Page 42166]]

    EPA also notes that the discharge of aqueous wastes generated 
during tank cleaning are generated only infrequently. EPA's data from 
the 3007 Questionnaire, shows that, on average, a single CSO tank is 
cleaned every 9 years and, on average, a refinery has four tanks 
containing CSO (for those that generate the residual). Therefore, a 
typical refinery generates CSO tank cleaning wastewaters less than once 
per year. Discharges of tank cleaning waters are infrequent and are 
expected to generate relatively small volumes of water in comparison 
with the typical wastewater flow through a refinery treatment system 
(see analysis noted below).
    Tank cleanings are used to facilitate tank inspections, which are 
critical to ensuring tank integrity and to avoiding catastrophic tank 
failure. Without this exemption, tank washing would become much more 
difficult because of the need to find alternative Subtitle C disposal 
methods for these wastewaters. Also, the tank washings are dramatically 
different in nature from the sediments characterized for the listing 
determination. While these washes are primarily water, the sediments 
are primarily solid, subject to land disposal methods such as the 
landfilling and land treatment evaluated in EPA's risk assessment.
    To respond fully to this commenter, EPA presented a further 
analysis in the NODA to illustrate the magnitude of treatment and 
dilution that would occur at the headworks of a refinery for both CSO 
tank sediment and spent hydrotreating/hydrorefining catalysts. (See 
Sections 8 and 9 in Supplemental Background Document-Listing Support 
Document, March 1997). EPA notes that it completed a similar analysis 
for crude oil storage tank sediment to respond to the commenter's 
concerns expressed about this waste also (see Additional Listing 
Support Analysis, 1998 in the docket). EPA concluded from these 
analyses that any impact on the downstream wastewater treatment sludge 
or wastewaters would be negligible.
    Comments on the NODA analysis for the headworks exemption argued 
that EPA based the assessment for CSO sediment on disposal of the waste 
itself in the wastewater treatment system, and that the exemption 
should be limited to dilute wastewaters. The commenter suggested that 
EPA set limits on maximum concentrations for contaminants in 
discharges, and limit the exemption to rinsate from the cleaning of 
tanks or other units. The commenter stated that these limitations 
should also apply to the existing exemption for heat exchanger bundle 
cleaning sludge, currently listed as hazardous waste K050, because the 
existing exemption suffers from the same flaws as the proposal. The 
commenter also indicated that if EPA does not limit the exemption to 
rinsate, the CSO assessment is flawed because it was based on the waste 
volume of the one facility reporting waste discharge into a wastewater 
treatment system in 1992. The commenter recognized that the facility no 
longer intends to employ the practice, but argued the potential exists 
for any generator of the waste to do so.
    In response, EPA notes that the purpose of the NODA exercise was to 
develop a ``what if'' scenario, representing the extreme case of CSO 
washwater loading to wastewater treatment. EPA concluded that because 
its ``what if'' scenario showed negligible risk, then no specific 
restrictions on washwater composition would be required. Furthermore, 
as discussed above in this section, EPA believes that there are 
significant disincentives for refineries to discharge high solids 
content waste to their wastewater treatment system. Finally, EPA notes 
that the existing exemption for heat exchanger bundle cleaning sludge 
(K050) was not explicitly reopened for comment, therefore the Agency is 
not considering any modification of this exemption in today's rule.
    Certainly, on-site wastewater treatment systems are available for 
this purpose throughout the refinery industry. EPA based its 
evaluations on the actual waste quantities used in particular 
management scenarios. EPA has no reason to believe, for example, that a 
quantity of waste destined for land treatment would be managed in a 
wastewater treatment system. EPA points out that a significant fraction 
of the wastes being listed must already be handled as hazardous, 
because they exhibit the TC or other characteristics. Yet despite this 
apparent incentive to avoid costly Subtitle C management, the disposal 
of tank sediment directly into the wastewater treatment system was 
extremely rare (i.e., only once each for CSO and crude oil storage tank 
sediments).
    The commenter also questioned whether the Agency accurately 
estimated the impact posed by the exemption, because EPA ignored the 
possibility that contaminants from other wastes and wastewaters would 
be codisposed with the potentially exempt waste in the wastewater 
treatment system. In response, EPA notes that its analysis was an 
attempt to gauge the significance of a worst-case discharge into the 
treatment system to determine if any significant incremental risks 
would result from the practice. EPA found no such incremental risks and 
therefore concluded that the exemption was appropriate. In fact, EPA 
found that risks due to the exempted wastes would be extremely small.
    The commenter expressed concern that the exemption would likely be 
encouraging the generation of larger quantities of hazardous wastewater 
treatment sludge, which would be incompatible with the waste 
minimization policy and objectives articulated by Congress in Section 
1003 of RCRA.
    In response, EPA believes that refineries have no incentive to 
discharge solids to wastewater treatment, because the solids would end 
up as F037 or other hazardous waste. As discussed above, other comments 
noted that the quantity of such primary sludge would be much greater 
than the quantity of solids initially dumped into the system.

E. Third Party Recycling of Spent Petroleum Catalysts

    In the November 20, 1995 proposal, the Agency suggested that it 
might be appropriate to exempt these thermal petroleum catalyst 
recovery units from RCRA Subtitle C regulation. The Agency solicited 
important additional information needed to adequately assess the basis 
for promulgating this potential exemption (see 60 FR at 57780). This 
information included the extent to which petroleum catalyst recovery 
units are currently equipped with emission control devices, the 
adequacy/efficiency of existing controls, and the amounts and 
concentrations of emissions of HAPs regulated under section 112 of the 
CAA as well as under Subtitle C of RCRA. (Id.)
    The Agency's preliminary findings in 1995, based on very limited 
data, indicate that these units may already be equipped with pollution 
controls comparable to those required under RCRA regulations for 
boilers and industrial furnaces (BIFs) that burn hazardous waste. 
However, EPA pointed out in 1995 the importance and need for additional 
air emissions data, in particular, information on the types and levels 
of HAPs being emitted from these offsite hazardous waste reclamation 
and regeneration units. (Id.)
    No information on these key factors was forthcoming on these units. 
Only one facility submitted a copy of its state air permit. The nature 
of, and data associated with, this facility's state permit are much too 
limited to provide an adequate record for the Agency to make a 
determination on whether to

[[Page 42167]]

exempt from RCRA controls this entire class of reclamation and 
regeneration units. The information in the permit is manifestly 
insufficient for such a determination. Even if it were more complete, 
EPA could likely not extrapolate the information from this single 
facility to all thermal units with an adequate degree of confidence. 
For instance, the permit contains limits only on emission rates of CAA 
criteria air pollutants carbon monoxide (CO), sulfuric oxides 
(SOX), nitrogen oxides (NOX), particulate matter 
(Method 10) (PM10), and volatile organic constituents 
(total-VOCs) on an average annual basis. Daily/hourly mass discharge 
rates or concentrations for these pollutants were lacking, as was any 
information on HAPs of concern under Section 112 of the CAA (and, 
because of their hazardousness, under RCRA as well), or the means by 
which such HAPs might be controlled. Also, this permit report lacks 
information on the destruction and removal efficiency (DREs) that the 
combustion unit can achieve for potential principal organic 
constituents (POCs) fed to the regeneration process (see 40 CFR 
266.104(2)). Finally, the permit report lacks information on the kind 
of controls for metal emissions as well as the types and levels of 
metals being emitted.
    EPA has no additional data on similar units and on the key factors 
to be considered in determining whether to finalize the proposed 
exemption. At this point, therefore, the administrative record for this 
rule is simply not sufficient to support a final decision one way or 
the other.
    Given the current state of the administrative record and the other 
circumstances discussed above, EPA is deferring to a later day any 
final decision on whether or not to exempt these units from RCRA 
Subtitle C air emission standards. The timing of this decision depends, 
in large part, on the gathering and submittal of additional data on the 
key factors identified above, especially the types and levels of HAP 
emissions from these units and the adequacy of air pollution controls 
for these emissions.
    EPA encourages owners and operators of these facilities to 
supplement the record with design, operation, and emissions information 
so that further progress toward a final determination on the potential 
exemption can be made. In the interim, EPA reiterates that nothing in 
today's rule (or indeed the proposed rule) changes the current RCRA 
status of facilities managing these hazardous wastes.

VI. Land Disposal Restrictions

A. Treatment Standards for Newly Identified Wastes

    The land disposal prohibition statutory provisions essentially 
require pretreatment of hazardous wastes so that threats to human 
health and the environment posed by land disposal of the waste are 
minimized (RCRA sections 3004(g)(4) and (m)). Land disposal 
prohibitions for hazardous wastes are to be promulgated pursuant to a 
phased schedule, the determination for newly listed wastes-those listed 
after adoption of the 1984 amendments-to be made within six months of 
promulgation of the listing (RCRA section 3004(g)(4)); see generally, 
55 FR 22523, June 1, 1990.) A determination to prohibit hazardous 
wastes from land disposal is essentially automatic, since only land 
disposal that satisfies the exacting statutory no-migration standard 
may be disposed without first satisfying the section 3004 (m) treatment 
standards. (Id). A method of land disposal may not be determined to be 
protective of human health and the environment until the waste has 
complied with 3004(m) pretreatment regulations, unless upon application 
of an interested person, it has been demonstrated to the Administrator, 
to a reasonable degree of certainty, that there will be no migration of 
hazardous constituents from the disposal unit or injection zone for as 
long as the wastes remain hazardous (RCRA section 3004(d)). No one 
contends that disposal of the petroleum wastes listed in this 
rulemaking satisfies the no-migration standard.
    EPA has traditionally developed treatment standards for prohibited 
hazardous wastes based upon the performance of BDAT. The Agency further 
refined this approach to use the same set of technology-based numerical 
treatment standards whenever factually justified. These are the so-
called UTS set out in Sec. 268.48, which provide numerical treatment 
standards for all hazardous constituents (i.e., constituents listed in 
Appendix VIII of Part 261).
    As part of the proposed rule, EPA proposed to apply the UTS 
applicable to the hazardous constituents in the newly listed petroleum 
refining industry wastes (see 60 FR 57783, November 20, 1995). EPA 
further requested data to adjust the numerical treatment standards 
applicable to the subject wastes to be consistent with the revisions to 
the UTS being considered in the Agency's Phase IV Land Disposal 
Restrictions rulemaking (see 62 FR 16751, April 8,1997). EPA has in 
fact recently slightly amended the treatment standards for the 
hazardous constituents antimony (see 63 FR 28562, May 26, 1998) and 
nickel (see 63 FR 28569, May 26, 1998). EPA also has amended the 
treatment standard for vanadium, which is not an underlying hazardous 
constituent (40 CFR 268.2(i)), but is being regulated in these wastes 
for the reasons given below. The constituents of concern as proposed 
and the treatment standards as revised are being promulgated for the 
newly identified K169, K170, K171, and K172 wastes. In accordance with 
section 3004(g)(4), EPA is also prohibiting the underground injection 
of these wastes (unless the wastes meet the treatment standard before 
injection without being diluted impermissibly, or unless the wastes are 
injected into a no-migration unit). Since underground injection is a 
type of land disposal (see section 3004(k)), this action is automatic, 
and implements the mandatory directive to prohibit land disposal of 
newly listed hazardous wastes found in section 3004(g)(4).

B. Response to Comments

    Additional comments, along with EPA's responses, are provided in 
the Response to Comments Background Documents for the proposed rule and 
the NODA located in the docket for this rule. Key comments are 
discussed below.
1. Constituents of Concern
    EPA received comment asking that, if listed, the LDR constituents 
of concern should be limited to benzene and arsenic. The commenter 
determined that these are the only two compounds which have significant 
risk associated with their management. The commenter maintains that the 
inclusion of the PAH compounds and other metals is not warranted and 
will require additional cost to characterize the material prior to 
management, and that their inclusion may prevent beneficial recycling 
practices due to unnecessary LDR requirements on reclaimer residuals.
    The Agency disagrees. EPA is required by statute to set ``...levels 
or methods of treatment, if any, which substantially diminish the 
toxicity of the waste or substantially reduce the likelihood of 
migration of hazardous constituents from the waste so that short-term 
and long-term threats to human health and the environment are 
minimized'' (RCRA section 3004(m), 42 U.S.C. 6924(m)). While the 
commenter is correct in that for K171 and K172 only benzene and arsenic 
were given as the basis of listing, treatment standards were also 
proposed for additional metals and PAHs. PAH compounds are highly 
carcinogenic, even at low

[[Page 42168]]

concentrations, and are present at significant concentrations in some 
petroleum residuals at levels exceeding the treatment standards. 
Although these constituents were not modeled to show significant risks 
through the pathways considered, the presence of these carcinogens in 
the wastes remains a potential threat to human health and the 
environment when the wastes are land disposed. Certainly, there is no 
basis for finding that threats posed by these constituents have been 
minimized without treatment (see Chemical Waste Management v. EPA, 976 
F.2d at 16.) The Agency also notes that treatment standards for PAHs 
and nickel are currently required for other similar listed petroleum 
wastes (F037, F038, and K048-K052) and that damage cases associated 
with these wastes have noted environmental effects due to both metals 
and PAHs (see Background Document to Support Listing of Primary Oil/
Water Separation Sludges, August 20, 1990, pages 6-8 ). Thus, the 
Agency is convinced that treatment of these constituents is necessary 
to minimize threats posed by the wastes' land disposal, and further 
convinced that the treatment standards are not established below levels 
at which such threats are minimized. The Agency is therefore 
promulgating treatment standards for all the constituents that were 
proposed to be regulated.
2. Sulfides
    The commenter recommended that if a new treatment standard for K171 
and K172 is adopted, it must include a concentration level for 
sulfides. The commenter believes a level of 500 ppm reactive sulfide 
should be specified as an exit level for land disposal restrictions, 
because the level has been used in Agency guidance to identify wastes 
that exhibit a hazardous waste characteristic for reactive sulfides as 
per OSWER policy memorandum No. 9443.1985(04). The commenter believes 
that without a numerical treatment level, the regulated community may 
be held to a double standard of having to meet the treatment standards 
for both a Listed Waste and a Characteristic Waste.
    EPA responds by clarifying that those K171 and K172 wastes that 
exhibit the hazardous waste characteristic of reactive sulfide are 
currently prohibited from land disposal unless first being treated to 
remove the characteristic by deactivation. Underlying hazardous 
constituents also must be treated (see existing Sec. 268.35 
(prohibition on land disposal of reactive hazardous wastes) and 
Sec. 268.40 (e) (underlying hazardous constituents in reactive wastes 
must also be treated). Furthermore, even after the listing takes 
effect, listed wastes may also exhibit one or more characteristics of a 
hazardous waste. Listed wastes which also exhibit characteristics of a 
hazardous waste must comply with all applicable treatment standards for 
characteristic wastes (unless the treatment standard for the listed 
waste contains a standard for the constituent that causes the waste to 
exhibit a characteristic; see Sec. 268.9(b)). Finally, treatment must 
reflect the ``minimize threat'' level for land disposal (3004 (d)(1) 
and (g)(4) (land disposal is prohibited ``unless the Administrator 
determines the prohibition on one or more methods of land disposal of 
such waste is not required in order to protect human health and the 
environment...''), and so may require treatment of constituents not 
technically hazardous constituents, but which make a waste more 
dangerous to land dispose (see 56 FR at 41168 (Aug. 19, 1991) and other 
sources there cited). Thus, although sulfides are not hazardous 
constituents (since they are not listed in Appendix VIII of Part 261), 
they nevertheless are present in these wastes at concentrations 
sufficient to provide harmful properties, including self-heating 
pyrophoric properties and potential reactivity which must be minimized 
for safe disposal (See 60 FR 57783-57785).
    As a point of clarification, the newly listed K171 and K172 wastes, 
which also are reactive, would have to comply with the UTS numerical 
levels for the specified hazardous constituents and deactivation for 
reactive sulfide prior to land disposal, but would not have to 
demonstrate compliance with all the underlying hazardous constituents 
(see Sec. 268.9 (b)). This is because the treatment standard itself 
already indicates what other constituents are present in these wastes 
requiring treatment so as to minimize threats posed by the wastes' land 
disposal. The Agency will continue to determine if a separate UTS 
number is required to access the deactivation of sulfide from reactive 
wastes and, if so, will propose a number in the future.
3. Underlying Hazardous Constituents
    A commenter stated that EPA should not subject listed hazardous 
wastes to LDR regulations regarding Underlying Hazardous Constituents 
(UHCs). The Agency wishes to clarify that listed wastes are not subject 
to UHCs per se. UHCs are regulated in characteristic wastes (40 CFR 
268.1). Listed wastes are regulated for the constituents which caused 
the waste to be listed and any other hazardous constituents specified 
in the specific treatment standard that are found to be present at 
levels where they could possibly cause harm to human health and the 
environment when the wastes are land disposed (see also discussion in 
the preceding paragraph). The basis for the distinction is that EPA has 
already studied the listed wastes to determine the hazardous 
constituents that are typically present, but is unable to do so for 
characteristic wastes, since, as a class, they are much more diverse. 
The Agency is promulgating treatment standards for each of the proposed 
hazardous constituents.
4. High Temperature Metals Recovery
    EPA received comments suggesting the designation of High 
Temperature Metals Recovery (HTMR) as an exclusive method of treatment. 
The Agency has finalized numerical standards for the newly listed 
wastes. Treaters may use any method they choose to achieve those 
standards, so long as the treatment is not considered impermissible 
dilution. The Agency believes this degree of flexibility is highly 
desirable to provide as many treatment options as possible, so long as 
the treatment satisfies the standards.
    In the case of the vanadium containing K171 and K172 wastes, metals 
recovery may be required to reduce the constituent to levels that can 
be subsequently treated to comply with the LDR treatment standard. 
Vanadium treatment is discussed more fully in the following section.
5. Vanadium
    Vanadium is not an underlying hazardous constituent of hazardous 
wastes that requires treatment in all characteristically hazardous 
wastes. (see 268.48 note 5). However, vanadium in the form of ammonium 
vanadate or vanadium pentoxide, are underlying hazardous constituents 
(since they are included in Appendix VIII of Part 261). In the course 
of the combustion of coke residues on the spent catalysts, vanadium 
compounds adsorbed on the catalysts are converted to vanadium pentoxide 
and the wastes are typically subjected to metals recovery for the 
vanadium pentoxide. Because the presence of vanadium pentoxide would 
impart acute toxicity to the wastes and can be readily measured as the 
vanadium metal, the Agency proposed treatment standards for vanadium as 
a constituent of concern in K171 and K172 as a surrogate measure to 
limit the presence of vanadium pentoxide in the wastes and to insure 
that the toxicity of the waste was diminished prior to disposal (see 
also 60 FR 57784, November 20, 1995). Without reduction

[[Page 42169]]

of their vanadium content, the K171 and K172 wastes would contain 
significant levels of vanadium in the form of toxic vanadium pentoxide.
    Commenters claimed that the proposed treatment standard for 
vanadium is not feasible and appropriate, based on EPA's testing. In 
response, EPA evaluated additional data from the stabilization of 
wastes containing vanadium at levels below which metals recovery is 
feasible and, based on this data, calculated a standard of 1.6 mg/L 
TCLP for nonwastewaters. The Agency proposed that this higher standard 
replace the 0.23 mg/L TCLP standard originally proposed and believes 
that this standard is readily achievable (see 62 FR 26047, May 12, 
1997). A facility unable to comply with the treatment standard may 
apply for a treatability variance under 40 CFR 268.42 (assuming the 
waste has been treated using the properly-operated technology on whose 
performance the treatment standard is based and is still unable to meet 
the treatment standard).
    One commenter claims that the Agency incorrectly assumed that spent 
catalysts and their residuals are physically and chemically similar to 
K048-K052 and K061 wastes. The commenter noted that the chemical 
composition of K048-K052 and K061 wastes is quite different than that 
of the K171 and K172 spent catalysts. The commenter identified other 
physical differences between spent catalysts and K048-K052 and K061 
wastes, and argued such differences apparently prevent the 
stabilization of vanadium in spent catalysts.
    The commenter is correct that the residuals are chemically and 
physically quite different at their respective points of generation, 
the principal difference is the higher concentration of vanadium in 
K171/K172. However, both K061 and K171/K172 contain similar 
constituents of concern which are largely metal oxides once K171/K172 
is deactivated. Data assembled by the commenters show that K048-K052 
contain 1-350 ppm vanadium and that K061 concentrations range from 0-
830 ppm, while vanadium in K171 ranges from 10-3300 ppm and, in K172, 
vanadium ranges from 25-31000 ppm. The commenter also states that K172 
has been observed as high as 150,000 ppm vanadium and notes that after 
deactivation to remove the D003 characteristic, the vanadium present is 
highly leachable. However, the commenter presents data reflecting 
attempts to stabilize the deactivated waste with cement and lime, 
rather than proceeding through the reclamation of a vanadium pentoxide 
product normally produced by metal reclaimers. The Agency maintains 
that following such reclamation, the treated waste would be very 
comparable to K046-K052 and K061 in vanadium content since little 
vanadium would remain. Data from reclaimers indicate that these 
processes recover over 90 percent of the vanadium present. Without such 
reclamation, it would be unlikely that high vanadium wastes, like K171/
K172, could be stabilized to the UTS level. The level of vanadium 
remaining after reclamation would still require stabilization to reduce 
the mobility of the toxic forms of vanadium. The Agency believes the 
vanadium UTS level can be achieved, therefore, through proper treatment 
which includes a reclamation step. Data on stabilization alone for high 
vanadium wastes do not reflect proper and effective treatment, and the 
Agency therefore is not compelled to modify the level based on this 
data.
    One commenter asserted that the treatment standard for vanadium 
could not be rationally based on International Mill Service (IMS) K061 
data and, to the extent that the standard could be based on INMETCO's 
K061 waste, the standard cannot be automatically transferred to spent 
catalysts because the resulting standards would not be achievable. The 
Agency responds that the prior treatment standard for vanadium was 
based on data obtained from IMS's HTMR facility. As revised in the 
recent Phase Four LDR Rule, the vanadium standard is derived from 
stabilization data. The performance levels promulgated were achievable 
by the other facilities from whom the Agency had also collected data 
(see 59 FR 47980, September 19, 1994). The Agency believes that the 
residuals following vanadium metal recovery of the K171 and K172 wastes 
can achieve the treatment standards measured on the basis of vanadium 
and provide protection against the significant presence of acutely 
toxic vanadium pentoxide in the land disposed waste. The commenter 
provided no data demonstrating that the treatment standards could not 
be met when metals recovery is performed.
6. Revisions to Proposed Standards
    The Agency requested data to adjust the numerical treatment 
standards applicable to the petroleum wastes subject of this rulemaking 
to be consistent with the treatment standards proposed in the Phase IV 
Land Disposal Restrictions (see 62 FR 26041, 26047-26048; May 12, 
1997). Commenters supported the proposed revisions to the treatment 
standards. In each case, the proposed standards reflect the higher of 
the stabilization-based or HTMR-based calculations, in order to provide 
flexibility to use various well-performing treatment technologies which 
substantially reduce toxicity or mobility of hazardous constituents. 
The commenter believes the revised treatment standards that EPA has 
proposed for antimony, nickel, and vanadium are supported by the 
underlying data and are achievable by both major treatment 
technologies.
    The Agency concurs with the commenters and also believes the BDAT 
methodology has been properly applied to the available data to 
calculate the revised treatment standards and that the levels are 
achievable by both major treatment technologies. Based on data 
submitted in the Phase IV rulemaking for nonwastewaters, the treatment 
level for antimony is finalized at 1.15 mg/L TCLP, the treatment level 
for nickel is finalized at 11.0 mg/L TCLP, and the treatment standard 
for the vanadium, which is applicable only to K061, K171, and K172 as a 
constituent of concern in these wastes, is finalized at 1.6 mg/L TCLP. 
The Agency is therefore promulgating these standards consistent with 
the levels finalized in the Phase Four Rulemaking. All other standards 
are promulgated as proposed.

C. Capacity Determination for Newly Identified Wastes

1. Introduction
    This section summarizes the results of the capacity analysis for 
the wastes covered by today's rule. For a detailed discussion of 
capacity analysis-related data sources, methodology, and detailed 
response to comments for each group of wastes covered in this rule, see 
the following document: ``Background Document for Capacity Analysis for 
Land Disposal Restrictions: Newly Identified Petroleum Refining Process 
Wastes (Final Rule)'' (i.e., the Capacity Background Document).
    EPA's decisions on whether to grant a national capacity variance 
are based on the availability of alternative treatment or recovery 
technologies. Consequently, the methodology focuses on deriving 
estimates of the quantities of waste that will require either 
commercial treatment or the construction of new on-site treatment or 
recovery as a result of the LDRs. The resulting estimates of required 
commercial capacity are then compared to estimates of available 
commercial capacity. If adequate commercial capacity exists, the waste 
is restricted from further land disposal before meeting the LDR 
treatment standards. If adequate capacity does not exist, RCRA

[[Page 42170]]

section 3004(h)(2) authorizes EPA to grant a national capacity variance 
for the waste for up to two years or until adequate alternative 
treatment capacity becomes available, whichever is sooner.
2. Capacity Analysis Results Summary
    For this capacity analysis, EPA examined data on waste 
characteristics and management practices that have been gathered for 
the petroleum refining industry study in the 1992 RCRA Section 3007 
survey. The Agency analyzed the capacity-related information from the 
survey responses, reviewed the public comments received in response to 
the proposed rule, contacted several commenters to obtain more specific 
information, and identified the following annualized quantities of 
newly identified hazardous wastes requiring commercial treatment: 4,400 
tons of K169; 3,200 tons of K170; 3,400 tons of K171; and 7,400 tons of 
K172. The available data sources indicate that there are no quantities 
of K169-K172 wastewaters that will require alternative commercial 
treatment.
    EPA is finalizing the rule to apply UTS to these wastes. The 
treatment standards for nonwastewaters containing organic constituents 
are based on combustion. The Agency determined that the available 
combustion capacity to treat these wastes far exceeds the waste 
quantities requiring alternative treatment when the listing 
determinations for these wastes become effective. Also, the Agency 
recognizes that the treatment residuals from these wastes may require 
additional treatment capacity (e.g., stabilization) to achieve the UTS 
for metal constituents. The Agency estimated that there several million 
MT per year of available commercial stabilization capacity. EPA also 
identified several metal recovery technologies that are commercially 
available, and some of these technologies are being used currently by 
the petroleum refining industry to recycle K171 and K172, although 
permitting and regulatory concerns expressed by some catalyst recyclers 
may need additional time to upgrade or expand their storage units. 
Since EPA is finalizing numerical standards for these wastes, all the 
technologies capable of achieving the final LDR treatment standards are 
not prohibited. Sufficient alternative treatment or recovery capacity 
exists to treat these wastes to meet the LDR standards. Therefore, EPA 
is not granting a national capacity variance under LDR for these 
wastes. The LDR standards for these wastes will become effective when 
the listings become effective.
    For soil and debris contaminated with the newly listed wastes, EPA 
proposed to not grant a national capacity variance. EPA received no 
comments regarding this issue. EPA believes that the majority of 
contaminated soil and debris will be managed on-site and therefore 
would not require substantial off-site commercial treatment capacity. 
Therefore, EPA is not granting a national capacity variance to 
hazardous soil and debris contaminated with the newly listed wastes 
covered under this rule. Based on the questionnaire, there were no data 
showing the mixed radioactive wastes with the newly listed wastes. 
There were also no comments concerning the radioactive wastes mixed 
with the newly identified wastes. EPA is not granting a national 
capacity variance for mixed radioactive wastes or soil and debris 
contaminated with these mixed radioactive wastes.
    EPA received comments concerning the availability of treatment and 
recovery capacity. One commenter requested a six-month delay in the 
effective date of the final rule, and two commenters requested that EPA 
grant a one- to two-year capacity variance to obtain permit 
modifications and construct any necessary plant upgrades. Commenters 
requested additional time to comply with various Subtitle C 
requirements, particularly relating to permitting and upgrading of 
areas used for storing K171 and K172 prior to the catalyst recycling 
process. Commenters requesting a two-year capacity variance for 
recycling facilities expressed concern about the potential economic 
impact on the facilities the Agency is relying on to provide the 
required treatment capacity. The commenters noted that, if promulgated 
as proposed, the Agency's listing would also mandate the application of 
the ``mixture'' and ``derived from'' rule for all management activities 
after the point of generation, placing additional regulatory burden 
(LDR treatment standards, upgrading of storage areas, potential Subpart 
CC compliance, and obtaining permits/variances) on environmentally 
sound management practices.
    Based on the results of the Agency's capacity analysis, adequate 
commercially available treatment or recovery capacity does currently 
exist for K171 and K172 wastes. Furthermore, granting a national 
capacity variance only exempts the waste from treatment standards prior 
to land disposal during the variance period, but does not exempt the 
waste from other Subtitle C requirements, such as the requirement to 
have a permit for storage of hazardous waste for greater than 90 days 
(at generator's sites). EPA believes that six months is sufficient to 
allow facilities to determine whether their wastes are affected by this 
rule and identify and locate alternative treatment or recovery capacity 
if necessary. Therefore, LDR treatment standards will become effective 
when the listing determinations become effective for the wastes covered 
under this rule (see RCRA section 3004(h)(1)(land disposal prohibitions 
must take effect immediately when there is sufficient protective 
treatment capacity for the waste available).

VII. Compliance and Implementation

A. State Authority

1. Applicability of Rules in Authorized States
    Under section 3006 of RCRA, EPA may authorize qualified States to 
administer and enforce the RCRA hazardous waste program within the 
State. (See 40 CFR Part 271 for the standards and requirements for 
authorization.) Following authorization, EPA retains enforcement 
authority under Sections 3007, 3008, 3013, and 7003 of RCRA, although 
authorized States have primary enforcement responsibility.
    Before the Hazardous and Solid Waste Amendments of 1984 (HSWA) 
amended RCRA, a State with final authorization administered its 
hazardous waste program entirely in lieu of the Federal program in that 
State. The Federal requirements no longer applied in the authorized 
State, and EPA could not issue permits for any facilities located in 
the State with permitting authorization. When new, more stringent 
Federal requirements were promulgated or enacted, the State was 
obligated to enact equivalent authority within specified time-frames. 
New Federal requirements did not take effect in an authorized State 
until the State adopted the requirements as State law.
    By contrast, under section 3006(g) of RCRA, 42 U.S.C. 6926(g), new 
requirements and prohibitions imposed by the HSWA (including the 
hazardous waste listings finalized in this notice) take effect in 
authorized States at the same time that they take effect in non-
authorized States. While States must still adopt HSWA-related 
provisions as State law to retain final authorization, EPA is directed 
to implement those requirements and prohibitions in authorized States, 
including the issuance of permits, until the State is granted 
authorization to do so.
    Authorized States are required to modify their programs only when 
EPA

[[Page 42171]]

promulgates Federal standards that are more stringent or broader in 
scope than existing Federal standards. Section 3009 of RCRA allows 
States to impose standards more stringent than those in the Federal 
program. See also 40 CFR 271.1(i). For those Federal program changes, 
both HSWA and non-HSWA, that are less stringent or reduce the scope of 
the Federal program, States are not required to modify their programs. 
Less stringent regulations, both HSWA and non-HSWA, do not go into 
effect in authorized States until those States adopt them and are 
authorized to implement them.
2. Effect on State Authorizations
    Today's rule is promulgated pursuant in part to HSWA authority and 
in part pursuant to non-HSWA authority. The listing of the new K wastes 
is promulgated pursuant to RCRA section 3001(e)(2), a HSWA provision. 
Therefore, the Agency is adding this rule to Table 1 in 40 CFR 
271.1(j), which identifies the Federal program requirements that are 
promulgated pursuant to HSWA and take effect in all States, regardless 
of their authorization status. The land disposal restrictions and the 
UTS for these wastes are promulgated pursuant to RCRA Section 3004(g) 
and (m), also HSWA provisions. Table 2 in 40 CFR 271.1(j) is modified 
to indicate that these requirements are self-implementing. States may 
apply for either interim or final authorization for the HSWA provisions 
in 40 CFR 271.1(j), as discussed below.
    Until the States receive authorization for these more stringent 
HSWA provisions, EPA will implement them. EPA will also implement the 
exemptions that are directly related to the new listings, such as the 
headwork exemption and the catalyst support media exemption. These 
exemptions are relevant only when regulating the newly listed wastes.
    Today's rule also includes several non-HSWA provisions that reduce 
the scope of the Federal program. These are the exclusions from the 
definition of solid waste of certain oil-bearing hazardous secondary 
materials from petroleum refining and certain recovered oils from 
associated petrochemical facilities. Although the States do not have to 
adopt these provisions, EPA strongly encourages them to do so, because 
the exclusions encourage material recovery within those industries.
    Today's revision to the listing description for F037 wastes at 
Sec. 261.31 neither broadens nor narrows the scope of the current 
program. This revision was made to ensure that residuals derived from 
recycling listed wastes, that are otherwise excluded under today's 
revised Sec. 261.4(a)(12), would remain listed. Because today's 
revision to the F037 waste code only applies in situations where the 
exclusion at Sec. 261.4(a)(12) applies, these provisions (the exclusion 
and the associated revised listing) should be adopted together, and 
taken together are considered to reduce the scope of the existing 
Federal requirements.
    Today's rule also amends the existing regulations to clarify that 
certain spent caustic solutions used as feedstock are not solid waste. 
This clarifying amendment (40 CFR 261.4(a)(19)) does not change the 
scope of the RCRA program because it does not actually change the 
current definition of solid waste. States do not need further 
authorization to interpret their regulations in accordance with this 
clarification.
    Lastly, regarding the non-HSWA amendments to the definition of 
solid waste (i.e., exclusions), a number of States qualified for final 
authorization prior to being required to adopt the redefinition of 
solid waste rulemaking of January 4, 1985 (50 FR 614). Since the 
January 4, 1985, rule is more stringent than the rule under which such 
States were authorized, such States were required to revise their 
programs in accordance with Sec. 271.21. Today's changes will not 
preclude EPA's ability to authorize States which have subsequently 
adopted the January 4, 1985, rule since it would reduce the scope of 
the Federal requirements. However, certain aspects of the State's 
regulation will be broader in scope than the Federal program and 
therefore not part of the authorized State program. This means that 
while they are enforceable under State law, they are not subject to 
Federal regulatory enforcement.\25\
---------------------------------------------------------------------------

    \25\ Today's rule affects only the regulatory definition of 
solid waste. It does not interpret the term ``solid waste'' for 
purposes of the non-regulatory authorities in RCRA sections 3007, 
3013, 7002, and 7003. thus, for purposes of those authorities, the 
Agency would have the benefit of the full jurisdictional reach of 
the statutory definition of solid waste. See Connecticut Coastal 
Fishermen's Association v. Remington Arms Co., 989 F2d 1305, 1314-15 
(2d. Cir. 1993) (comparing the narrower regulatory definition of 
solid waste for determining the scope of Subtitle C regulation with 
the broader statutory definition); Comite. Pro Rescate de la Salud 
v. Puerto Rico Aqueduct and Sewer Authority, 888 F.2d 180, 187 (1st 
Cir. 1990) (noting that under RCRA EPA could implement two different 
definitions of solid waste: a broader definition for imminent and 
substantial endangerment authority and a more narrow definition for 
regulatory purposes).
---------------------------------------------------------------------------

    A State submitting a program modification for the portions of this 
rule promulgated pursuant to HSWA authority may apply to receive either 
interim authorization under RCRA section 3006(g) or final authorization 
under 3006(b), if the State requirements are, respectively, 
substantially equivalent or equivalent to EPA's requirements. States 
can only receive final authorization for program modifications 
implementing non-HSWA requirements. The procedures and schedule for 
final authorization of State program modifications are described in 40 
CFR 271.21. It should be noted that all HSWA interim authorizations are 
currently scheduled to expire on January 1, 2003 (see 57 FR 60129, 
February 18, 1992).
    Section 271.21(e)(2) of EPA's State authorization regulations (40 
CFR part 271) requires that States with final authorization modify 
their programs to reflect Federal program changes and submit the 
modifications to EPA for approval. The deadline by which the States 
must modify their programs to adopt this regulation is determined by 
the date of promulgation of a final rule in accordance with section 
271.21(e)(2). Table 1 at 40 CFR 271.1 is amended accordingly. Once EPA 
approves the modification, the State requirements become RCRA Subtitle 
C requirements.
    States with authorized RCRA programs already may have regulations 
similar to those in this rule. These State regulations have not been 
assessed against the Federal regulations being finalized to determine 
whether they meet the tests for authorization. Thus, a State would not 
be authorized to implement these regulations as RCRA requirements until 
State program modifications are submitted to EPA and approved, pursuant 
to 40 CFR 271.21. Of course, States with existing regulations that are 
more stringent than or broader in scope than current Federal 
regulations may continue to administer and enforce their regulations as 
a matter of State law. In implementing the HSWA requirements, EPA will 
work with the States under agreements to avoid duplication of effort.

B. Effective Date

    The effective date of today's rule is February 8, 1999, except as 
specified in the Effective Dates section. As discussed above, since 
today's rule is issued pursuant to HSWA authority, EPA will regulate 
the management of the newly identified hazardous wastes until States 
are authorized to regulate these wastes. Thus, EPA will apply Federal 
regulations to these wastes and to their management in both authorized 
and unauthorized States.

[[Page 42172]]

C. Section 3010 Notification

    Pursuant to RCRA section 3010, the Administrator may require all 
persons who handle hazardous wastes to notify EPA of their hazardous 
waste management activities within 90 days after the wastes are 
identified or listed as hazardous. This requirement may be applied even 
to those generators, transporters, and treatment, storage, and disposal 
facilities (TSDFs) that have previously notified EPA with respect to 
the management of other hazardous wastes. The Agency has decided to 
waive this notification requirement for persons who handle wastes that 
are covered by today's listings and have already (1) notified EPA that 
they manage other hazardous wastes, and (2) received an EPA 
identification number. The Agency has waived the notification 
requirement in this case because it believes that most, if not all, 
persons who manage these wastes have already notified EPA and received 
an EPA identification number. However, any person who generates, 
transports, treats, stores, or disposes of these wastes and has not 
previously received an EPA identification number must obtain an 
identification number pursuant to 40 CFR 262.12 to generate, transport, 
treat, store, or dispose of these hazardous wastes by November 4, 1998.

D. Generators and Transporters

    Persons that generate newly identified hazardous wastes may be 
required to obtain an EPA identification number if they do not already 
have one (as discussed in section VI.C, above). In order to be able to 
generate or transport these wastes after the effective date of this 
rule, generators of the wastes listed today will be subject to the 
generator requirements set forth in 40 CFR part 262. These requirements 
include standards for hazardous waste determination (40 CFR 262.11), 
compliance with the manifest (40 CFR 262.20 to 262.23), pretransport 
procedures (40 CFR 262.30 to 262.34), generator accumulation (40 CFR 
262.34), record keeping and reporting (40 CFR 262.40 to 262.44), and 
import/export procedures (40 CFR 262.50 to 262.60). It should be noted 
that the generator accumulation provisions of 40 CFR 262.34 allow 
generators to accumulate hazardous wastes without obtaining interim 
status or a permit only in units that are container storage units or 
tank systems; the regulations also place a limit on the maximum amount 
of time that wastes can be accumulated in these units. If these wastes 
are managed in surface impoundments or other units that are not tank 
systems or containers, these units are subject to the permitting 
requirements of 40 CFR parts 264 and 265, and the generator is required 
to obtain interim status and seek a permit (or modify interim status or 
a permit, as appropriate). Also, persons who transport newly identified 
hazardous wastes will be required to obtain an EPA identification 
number as described above and will be subject to the transporter 
requirements set forth in 40 CFR part 263.

E. Facilities Subject to Permitting

1. Facilities Newly Subject to RCRA Permit Requirements
    Facilities that treat, store, or dispose of wastes that are subject 
to RCRA regulation for the first time by this rule (that is, facilities 
that have not previously received a permit pursuant to section 3005 of 
RCRA and are not currently operating pursuant to interim status), might 
be eligible for interim status (see section 3005(e)(1)(A)(ii) of RCRA). 
In order to obtain interim status based on treatment, storage, or 
disposal of such newly identified wastes, eligible facilities are 
required to comply with 40 CFR 270.70(a) and 270.10(e) by providing 
notice under section 3010 and submitting a Part A permit application no 
later than February 8, 1999. Such facilities are subject to regulation 
under 40 CFR part 265 until a permit is issued.
    In addition, under section 3005(e)(3) and 40 CFR 270.73(d), not 
later than February 8, 1999, land disposal facilities newly qualifying 
for interim status under section 3005(e)(1)(A)(ii) also must submit a 
Part B permit application and certify that the facility is in 
compliance with all applicable groundwater monitoring and financial 
responsibility requirements. If the facility fails to submit these 
certifications and a permit application, interim status will terminate 
on that date.
2. Existing Interim Status Facilities
    Pursuant to 40 CFR 270.72(a)(1), all existing hazardous waste 
management facilities (as defined in 40 CFR 270.2) that treat, store, 
or dispose of the newly identified hazardous wastes and are currently 
operating pursuant to interim status under section 3005(e) of RCRA, 
must file an amended Part A permit application with EPA no later than 
the effective date of today's rule, (i.e., February 8, 1999). By doing 
this, the facility may continue managing the newly listed wastes. If 
the facility fails to file an amended Part A application by that date, 
the facility will not receive interim status for management of the 
newly listed hazardous wastes and may not manage those wastes until the 
facility receives either a permit or a change in interim status 
allowing such activity (40 CFR 270.10(g)).
3. Permitted Facilities
    Facilities that already have RCRA permits must request permit 
modifications if they want to continue managing newly listed wastes 
(see 40 CFR 270.42(g)). This provision States that a permittee may 
continue managing the newly listed wastes by following certain 
requirements, including submitting a Class 1 permit modification 
request by the date on which the waste or unit becomes subject to the 
new regulatory requirements (i.e., the effective date of today's rule), 
complying with the applicable standards of 40 CFR parts 265 and 266 and 
submitting a Class 2 or 3 permit modification request within 180 days 
of the effective date.
    Generally, a Class 2 modification is appropriate if the newly 
listed wastes will be managed in existing permitted units or in newly 
regulated tank or container units and will not require additional or 
different management practices than those authorized in the permit. A 
Class 2 modification requires the facility owner to provide public 
notice of the modification request, a 60-day public comment period, and 
an informal meeting between the owner and the public within the 60-day 
period. The Class 2 process includes a ``default provision,'' which 
provides that if the Agency does not reach a decision within 120 days, 
the modification is automatically authorized for 180 days. If the 
Agency does not reach a decision by the end of that period, the 
modification is permanently authorized (see 40 CFR 270.42(b)).
    A Class 3 modification is generally appropriate if management of 
the newly listed wastes requires additional or different management 
practices than those authorized in the permit or if newly regulated 
land-based units are involved. The initial public notification and 
public meeting requirements are the same as for Class 2 modifications. 
However, after the end of the 60-day public comment period, the Agency 
will grant or deny the permit modification request according to the 
more extensive procedures of 40 CFR part 124. There is no default 
provision for Class 3 modifications (see 40 CFR 270.42(c)).
    Under 40 CFR 270.42(g)(1)(v), for newly regulated land disposal 
units, permitted facilities must certify that the facility is in 
compliance with all applicable 40 CFR part 265 groundwater monitoring 
and financial responsibility requirements no later than February 8, 
1999. If the facility fails to submit these

[[Page 42173]]

certifications, authority to manage the newly listed wastes under 40 
CFR 270.42(g) will terminate on that date.
4. Units
    Units in which newly identified hazardous wastes are generated or 
managed will be subject to all applicable requirements of 40 CFR part 
264 for permitted facilities or 40 CFR part 265 for interim status 
facilities, unless the unit is excluded from such permitting by other 
provisions, such as the wastewater treatment tank exclusions (40 CFR 
264.1(g)(6) and 265.1(c)(10)) and the product storage tank exclusion 
(40 CFR 261.4(c)). Examples of units to which these exclusions could 
never apply include landfills, LTUs, waste piles, incinerators, and any 
other miscellaneous units in which these wastes may be generated or 
managed.
5. Closure
    All units in which newly identified hazardous wastes are treated, 
stored, or disposed after the effective date of this regulation that 
are not excluded from the requirements of 40 CFR parts 264 and 265 are 
subject to both the general closure and post-closure requirements of 
Subpart G of 40 CFR parts 264 and 265 and the unit-specific closure 
requirements set forth in the applicable unit technical standards 
Subpart of 40 CFR parts 264 or 265 (e.g., Subpart N for landfill 
units). In addition, EPA promulgated a final rule that allows, under 
limited circumstances, regulated landfills, surface impoundments, or 
LTUs to cease managing hazardous waste but to delay Subtitle C closure 
to allow the unit to continue to manage non-hazardous waste for a 
period of time prior to closure of the unit (see 54 FR 33376, August 
14, 1989). Units for which closure is delayed continue to be subject to 
all applicable 40 CFR parts 264 and 265 requirements. Dates and 
procedures for submittal of necessary demonstrations, permit 
applications, and revised applications are detailed in 40 CFR 
264.113(c) through (e) and 265.113(c) through (e).

F. Landfill Leachate

    Just weeks before the date for signature of this rule, one waste 
management company raised to the Agency an issue not addressed in their 
(or any other commenters'') public comments. The issue is that the 
company claims to operate landfills in which some or all of the wastes 
being listed today have already been disposed. These landfills generate 
substantial volumes of leachate, which is collected and managed--mostly 
by shipment via truck for treatment at Publicly Owned Treatment Works 
(POTWs). On the date the listings take effect, the wastes become 
hazardous, and a consequence is that this leachate would likewise be a 
hazardous waste by virtue of the derived-from rule. See generally 53 FR 
at 31147 (August 17, 1988); see also Chemical Waste Management v. EPA, 
869 F. 2d 1526, 1536-37 (D.C. Cir. 1989) (sustaining this 
interpretation). Although the landfills in which the wastes have been 
previously disposed do not thereby become subject to Subtitle C 
regulation, id., leachate which is collected and actively managed would 
be regulated under Subtitle C. Id.
    EPA's Office of Water recently proposed national effluent 
limitations guidelines and pretreatment standards for wastewater 
discharges (e.g., leachate) from certain types of landfills. 63 FR 6426 
(February 6, 1998). In support of this proposal, EPA conducted a study 
of the volume and chemical composition of wastewaters generated by both 
Subtitle C and Subtitle D landfills. EPA did not propose pretreatment 
standards for Subtitle D landfill wastewaters sent to POTWs because the 
Agency's information indicated that such standards were not required 
due to several factors, including (1) raw leachate data was below 
published biological inhibition levels, and (2) lack of pass-through of 
toxics (including lack of showing of adverse impact on POTW sludge 
quality). 63 FR at 6444. EPA initially found, among other things, that 
``the majority of pollutants typically found in raw [non-hazardous 
landfill] leachate were at levels comparable to wastewater typically 
found at the headworks of a POTW.'' Id.
    Leachate from non-hazardous waste landfills that have historically 
managed the newly-listed wastes would be leachate from a Subtitle D 
facility, and so could ultimately be determined not to require 
pretreatment under this pending proposal. However, if Subtitle C 
regulation were to apply to leachate generated from such landfills, 
leachate now trucked to POTWs would, as a practical matter, no longer 
be managed by POTWs, since POTWs would not wish to become RCRA Subtitle 
C facilities. Given the pending proposal that directly addresses the 
treatment of landfill leachate under the Clean Water Act, EPA believes 
it worthwhile to study whether RCRA regulation of such leachates may be 
duplicative within the meaning of RCRA section 1006(b)(1) (which 
requires EPA to integrate regulations under RCRA with other statutes 
implemented by EPA in a manner that avoids duplication to the maximum 
extent possible, consistent with the goals and policies of RCRA and the 
other statutes).
    Since this leachate issue was not brought to the Agency's attention 
in a timely manner, EPA is taking no action on this issue in this 
rulemaking. The final rule thus simply finalizes four of the proposed 
listings (K169, K170, K171, and K172), therefore the possibility exists 
that some leachate may be classified by one or more of these waste 
codes (after the effective date of today's rule) for the reasons 
outlined above. However, the Agency is seeking public comment on the 
issue by means of a Notice of Data Availability (NODA), published 
elsewhere in today's Federal Register. EPA plans to take some type of 
action addressing this issue, after considering any public comments to 
this projected NODA, before today's listings take effect. One of the 
options the Agency might consider (after consideration of comments and 
information in response to the NODA) would be temporarily deferring the 
application of the listings to the leachate.

VIII. CERCLA Designation and Reportable Quantities

    All hazardous wastes listed under RCRA and codified in 40 CFR 
261.31 through 261.33, as well as any solid waste that is not excluded 
from regulation as a hazardous waste under 40 CFR 261.4(b) and that 
exhibits one or more of the characteristics of a RCRA hazardous waste 
(as defined in Secs. 261.21 through 261.24), are hazardous substances 
under CERCLA, as amended (see CERCLA section 101(14)(C)). CERCLA 
hazardous substances are listed in Table 302.4 at 40 CFR 302.4 along 
with their reportable quantities (RQs). If a hazardous substance is 
released in an amount that equals or exceeds its RQ, the release must 
be reported immediately to the National Response Center (NRC) pursuant 
to CERCLA section 103.

A. Reporting Requirements

    Under CERCLA section 103(a), the person in charge of a vessel or 
facility from which a hazardous substance has been released in a 
quantity that is equal to or exceeds its RQ must immediately notify the 
NRC as soon as that person has knowledge of the release. The toll-free 
telephone number of the NRC is 1-800-424-8802; in the Washington, DC, 
metropolitan area, the number is (202) 267-2675. In addition to this 
reporting requirement under CERCLA, section 304 of EPCRA requires 
owners or operators of certain facilities to report releases of 
extremely hazardous substances and CERCLA hazardous substances to State

[[Page 42174]]

and local authorities. EPCRA section 304 notification must be given 
immediately after the release of an RQ or more to the community 
emergency coordinator of the local emergency planning committee for any 
area likely to be affected by the release and to the State emergency 
response commission of any State likely to be affected by the release.
    Under section 102(b) of CERCLA, all hazardous substances (as 
defined by CERCLA section 101(14)) have a statutory RQ of one pound, 
unless and until the RQ is adjusted by regulation. In today's final 
rule, EPA is adding waste streams K169, K170, K171, and K172 to the 
CERCLA list of hazardous substances and adjusting the one-pound 
statutory RQs for these wastes.

B. Standard and Alternative RQ Adjustment Methodology

    EPA's methodology for adjusting the RQs of individual hazardous 
substances begins with an evaluation of the intrinsic physical, 
chemical, and toxicological properties of each hazardous substance. The 
intrinsic properties examined-called ``primary criteria''-are aquatic 
toxicity, mammalian toxicity (oral, dermal, and inhalation), 
ignitability, reactivity, chronic toxicity, and potential 
carcinogenicity.
    Generally, for each intrinsic property, EPA ranks the hazardous 
substance on a five-tier scale, associating a specific range of values 
on each scale with an RQ value of 1, 10, 100, 1,000, or 5,000 pounds. 
Based on the various primary criteria, the hazardous substance may 
receive several tentative RQ values. The lowest of the tentative RQs 
becomes the ``primary criteria RQ'' for that substance.
    After the primary criteria RQ is assigned, the substance is 
evaluated further for its susceptibility to certain degradative 
processes, which are used as secondary RQ adjustment criteria. These 
natural degradative processes are biodegradation, hydrolysis, and 
photolysis (BHP). If a hazardous substance, when released into the 
environment, degrades relatively rapidly to a less hazardous form by 
one or more of the BHP processes, its primary criteria RQ is generally 
raised one level. Conversely, if a hazardous substance degrades to a 
more hazardous product after its release, the original substance is 
assigned an RQ equal to the RQ for the more hazardous substance, which 
may be one or more levels lower than the RQ for the original substance.
    The standard methodology used to adjust the RQs for RCRA hazardous 
waste streams differs from the methodology applied to individual 
hazardous substances. The procedure for assigning RQs to RCRA waste 
streams is based on an analysis of the hazardous constituents of the 
waste streams. The constituents of each RCRA hazardous waste stream are 
identified in 40 CFR part 261, Appendix VII. EPA determines an RQ for 
each constituent within the waste stream and establishes the lowest RQ 
value of these constituents as the adjusted RQ for the waste stream. In 
a November 20, 1995, proposed rule (60 FR 57747), EPA proposed one-
pound RQs for waste streams K169, K170, K171, and K172 based on this 
standard methodology.
    In the same rule, however, the Agency also proposed an alternative 
method for adjusting the RQs of these four petroleum refining wastes. 
The proposed alternative method involved developing ``concentration-
weighted'' RQs for the four wastes. Using this alternative method, EPA 
first determined the maximum observed concentrations of each hazardous 
constituent in the wastes. EPA then used these concentrations to 
calculate the amount of each petroleum refining waste necessary to 
contain the RQ of each constituent of concern.
    Based on these calculated amounts, EPA assigned a ``concentration-
weighted'' RQ value of 1, 10, 100, 1,000, or 5,000 pounds to each waste 
stream constituent. If the calculated amount for a particular 
constituent was greater than the maximum RQ level of 5,000 pounds, the 
``concentration-weighted'' constituent RQ would be 5,000 pounds. If the 
calculated amount fell between two RQ levels, then the ``concentration-
weighted'' constituent RQ would be the lower of the two levels. 
Finally, under this alternative method, the lowest of the 
concentration-weighted constituent RQs would become the RQ for the 
waste stream.

C. Basis for RQ Adjustments in Final Rule

    In today's final rule, EPA has decided to use the standard RQ 
adjustment methodology to assign RQs to petroleum refining wastes K169, 
K170, K171, and K172. The Agency believes that introduction of a second 
methodology (i.e., the alternative method described above), in addition 
to the standard method already in use, may be difficult to implement 
and may unnecessarily confuse the public and the regulated community.
    EPA considered three specific implications of adopting the 
alternative RQ adjustment methodology in making its determination to 
retain the standard method. First, promulgation of RQs based on the 
alternative methodology for the four petroleum refining wastes would 
have introduced a potentially confusing situation in which RQs for 
currently listed hazardous waste streams would be based on two 
different methodologies. Second, since EPA's initial RQ adjustment 
rulemakings were first published in 1983, EPA has consistently applied 
the standard methodology to adjust the RQs for all previously listed 
RCRA wastestream. Members of the public and the regulated community 
understand and are complying with this methodology and related 
reporting requirements. Third, the reduced reporting burden expected 
from the application of the alternative method (i.e., reporting based 
on constituent concentrations) to the four petroleum refining wastes 
can be achieved by applying the mixture rule (as described in Section 
VIII.D, ``Responses to Comments,'' of this preamble), without creating 
a second, different RQ adjustment methodology.
    Based on these considerations, the Agency has decided to use the 
standard methodology, rather than the alternative method, to adjust the 
RQs for the petroleum refining wastes in today's final rule. Using the 
standard method, EPA today is assigning one-pound adjusted RQs (as 
proposed) for waste streams K170, K171, and K172 based on the 
constituent(s) within each of these newly listed waste streams with the 
lowest RQ. The Agency, however, is modifying its interpretation of the 
mixture rule (as described in detail in Section VIII.D below) to allow 
facilities to use the maximum observed concentrations of the 
constituents within the petroleum refining wastes in determining when 
to report releases of these wastes.
    In addition, EPA mentioned in the preamble to the November 20, 
1995, proposed rule that the Agency was considering listing waste 
stream K169 (crude oil storage tank sediment). Subsequent to the 
proposal, EPA has decided to list K169 as a RCRA hazardous waste and a 
CERCLA hazardous substance, and to adjust its RQ.
    In the November 20, 1995 rule, EPA was considering a one-pound RQ 
for K169 based on the one-pound RQs of three substances 
(benzo(a)pyrene, dibenzo(a,h)anthracene, and benzo(b)fluoranthene) 
originally identified by the Agency as constituents of this waste 
stream. After further evaluation of the constituent data, however, the 
Agency has decided in today's final rule to identify only one hazardous 
constituent (i.e., benzene) for waste stream K169 in Appendix VII to

[[Page 42175]]

40 CFR part 261 (see Section V.B.2 for a discussion of the basis for 
listing K169). Thus, using the standard RQ adjustment method, EPA is 
promulgating a 10-pound RQ for K169 in today's final rule based on the 
10-pound RQ of the waste's single hazardous constituent, benzene.

D. Response to Comments

    As noted above, the Agency has decided to use the standard 
methodology to adjust the RQs for K169, K170, K171, and K172. The 
commenters on the proposed rule, however, favored the alternative RQ 
adjustment methodology. These commenters suggested that reporting 
should be based on actual concentration levels observed in each of the 
petroleum refining wastes and that these levels are more likely to 
warrant notification of government authorities.
    In addition, one of the commenters asked EPA to clarify that a 
waste generator could retain the option of applying the mixture rule to 
releases of these petroleum refining wastes. Specifically, this would 
allow the generator to report at a higher level if the generator knew 
that the concentrations of the constituents in the waste were lower 
than the maximum observed concentrations identified by EPA.
    EPA acknowledges the commenters' support for less burdensome 
reporting requirements and agrees with the commenters' assertion that 
reporting for the four petroleum refining wastes should be based on 
actual concentration levels observed in each of these wastes. The 
Agency, however, believes that reductions in the reporting burden for 
these four wastes can be achieved through the use of the mixture rule, 
without creating a second, distinct RQ adjustment methodology. In 
response to the commenters' concerns, the Agency is modifying its 
interpretation of the mixture rule, as described below, to allow 
facilities to use the maximum observed concentrations of the 
constituents within K169, K170, K171, and K172 in determining when to 
report releases of these wastes.
    For K169, K170, K171, and K172, where the person in charge does not 
know the actual concentrations of the hazardous constituents, that 
person will have the option of reporting on the basis of the maximum 
observed concentrations that have been identified by EPA (see Table 
VIII-1 below). The change in EPA's interpretation of the mixture rule 
that will allow use of these maximum concentrations is codified in 40 
CFR 302.6(b)(1) as a new subparagraph (iii) in today's rule. Thus, 
although the person in charge lacks actual knowledge of constituent 
concentrations, constructive knowledge of the EPA-identified maximum 
concentrations is assumed. This assumption is reasonable and 
conservative because the sampling data presented in the Technical 
Listing Document accurately identify the maximum observed 
concentrations of the hazardous constituents in each of the petroleum 
refining wastes. Table VIII-1 below identifies the hazardous 
constituents for waste streams K169, K170, K171, and K172, their 
maximum observed concentrations in ppm, their constituents' RQs as 
listed in Table 302.4 of 40 CFR part 302, and the number of pounds of 
the waste needed to contain an RQ of each constituent.

                        Table VIII-1.--Pounds Required to Contain RQ for Each Constituent                       
----------------------------------------------------------------------------------------------------------------
                                                                                                      Pounds    
              Waste                           Constituent                 Max ppm      RQ (lb)      required to 
                                                                                                    contain RQ  
----------------------------------------------------------------------------------------------------------------
K169                              Benzene............................         220             10          45,455
K170                              Benzene............................           1.2           10       8,333,333
                                  Benzo (a) pyrene...................         230              1           4,348
                                  Dibenz (a,h)anthracene.............          49              1          20,408
                                  Benzo (a)anthracene................         390             10          25,641
                                  Benzo fluoranthene.................         110              1           9,090
                                  Benzo (k) fluoranthene.............         110           5000      45,454,545
                                  3-Methylcholanthrene...............          27             10         370,370
                                  7,12-Dimethylbenz (a) anthracene...       1,200              1             833
K171                              Benzene............................         500             10          20,000
                                  Arsenic............................       1,600              1             625
K172                              Benzene............................         100             10         100,000
                                  Arsenic............................         730              1           1,370
----------------------------------------------------------------------------------------------------------------

    For example, if waste stream K171 is released from a facility and 
the person in charge does not know the actual concentrations of the 
benzene and arsenic constituents, the person may assume that the 
concentrations of benzene and arsenic are 500 and 1,600 ppm. 
respectively. Thus, applying the mixture rule, 625 pounds of the K171 
waste would need to be released (assuming the maximum concentrations 
indicated in the table) to reach the RQ for arsenic in this waste.
    Where the person in charge knows the concentration levels of all 
the hazardous constituents in a particular petroleum refining waste, 
the traditional mixture rule can be applied. Under this scenario, 
reporting would be required only when an RQ or more of any hazardous 
constituent is released. As applied to the petroleum refining wastes in 
this rule, EPA's overall reporting approach reduces the burden of 
notification requirements for the regulated community and adequately 
protects public health and welfare and the environment. In addition, 
EPA believes that the approach described above is consistent with the 
view expressed by the commenters that reporting for the four wastes 
should be based on actual concentration levels.
    In the proposed rule preamble, EPA identified ``self-heating 
solids'' as a hazardous constituent of waste streams K171 and K172. Two 
of the commenters disagreed with the Agency's use of this term and 
indicated that most K171 and K172 wastes do not demonstrate the RCRA 
characteristic of ignitability. According to these commenters, the few 
wastes that do exhibit this characteristic will already be subject to 
the 100-pound RQ that applies to ignitable characteristic wastes. 
Finally, the commenters stated that EPA's use of the term ``self-
heating solid'' as a constituent of K171 and K172 wastes would unfairly 
lower the RQ for those wastes that do not possess the RCRA 
characteristic of ignitability. EPA agrees with the commenters and has 
removed the term ``self-heating solids'' from the

[[Page 42176]]

list of constituents of K171 and K172 in Table VIII-1 of today's final 
rule.

IX. Executive Order 12866

    Under Executive Order 12866, ``Regulatory Planning and Review'' (58 
FR 51735, October 4, 1993), the Agency must determine whether the 
regulatory action is ``significant'' and therefore subject to OMB 
review and the requirements of the Executive Order. The Order defines 
``significant regulatory action'' as one that is likely to result in a 
rule that may:

    (1) have an annual effect on the economy of $100 million or more 
or adversely affects in a material way the economy, a sector of the 
economy, productivity, competition, jobs, the environment, public 
health or safety, or State, local, or tribal governments or 
communities
    (2) create a serious inconsistency or otherwise interferes with 
an action taken or planned by another agency
    (3) materially alter the budgetary impact of entitlements, 
grants, user fees, or loan programs or the rights and obligations of 
recipients thereof
    (4) raise novel legal or policy issues arising out of legal 
mandates, the President's priorities, or the principles set forth in 
this Executive order.

    Pursuant to the terms of Executive Order 12866, it has been 
determined that this rule is a ``significant regulatory action'' 
because of policy issues arising out of legal mandates. As such, this 
action was submitted to OMB for review. Changes made in response to OMB 
suggestions or recommendations are documented in the public record.

X. Economic Analysis

Summary

    This section of the preamble develops the costs and the industry 
economic impact for the petroleum refining waste listings including 
land disposal restriction (LDR) impacts. Based on this economic 
analysis, the Agency estimates that the listing of the four refinery 
wastes discussed above, including LDR impacts, the oil-bearing 
hazardous secondary material exclusion (oil-bearing exclusion) and the 
wastewaters from the headworks exemptions for crude oil storage tank 
sediment (K169) and CSO sediment (K170), will result in nationwide 
annualized compliance costs between $20 and $40 million, with an 
expected value of about $30 million ($1997) 26 (see Table X-
2 below). Although Table X-2 shows a range from approximately $12 
million to $60 million (columns 5 and 6), the likely range will be 
narrower due to the available refinery choices and expected waste 
volumes. The wide variance is nonetheless due to a high degree of 
uncertainty in costing and, particularly, in volumes to be processed.
---------------------------------------------------------------------------

    \26\ The range of cost estimates is explained in Document 5 of 
the ``Background Documents for the Cost and Economic Impact Analysis 
of Listing Four Petroleum Refining Wastes as Hazardous Under RCRA 
Subtitle C,'' January 10, 1998.
---------------------------------------------------------------------------

    Of special note is the relationship of previously listed petroleum 
refinery wastes to this rulemaking. The ability to recycle wastes 
through coker processing, as described herein, will enable refineries 
to process previously listed wastes in a like manner. These wastes 
include FO37, FO38, KO48, KO49 and KO51. A conservative estimate of the 
volume of these wastes that may be processed, yielding oil that may be 
converted to product, results in feedstock having a value of some $14 
million to $28 million ($1997); see background document entitled 
``Other Benefits From Recovery of Oil in Coker Processing Units'', 
dated August 24, 1995. Clearly, the impact of this ``other'' benefit as 
a potential offset to the costs of the rule described herein can be 
substantial. If the volumes available from previously listed wastes are 
higher than estimated, the value of oil generated may substantially 
offset the costs of this rulemaking. It is important to note that EPA 
has insufficient data to judge the extent to which the industry may 
already be generating this added feedstock.
    Industry pricing and operating impacts, developed using partial 
equilibrium analysis, are expected to be minimal. This is due both to 
the size of the industry and the latitude afforded industry in this 
rulemaking. The full economic analysis is available in the regulatory 
docket titled ``Background Documents for the Cost and Economic Impact 
Analysis of Listing Four Petroleum Wastes as Hazardous Under RCRA 
Subtitle C,'' January 10, 1998.
    In the cited background document, supplemental cost impact analyses 
accounting for the cost savings of the oil-bearing exclusion and the 
headworks exemption are included, as well as impacts resulting from the 
new Small Business Regulatory Enforcement Fairness Act of 1996 (SBREFA) 
and the potential for unfunded mandates. Finally, as noted above, cost 
savings from the recovery of oil in coker processing units are 
evaluated for five previously listed petroleum refining industry wastes 
but , also as noted, are not included as offsets to the costs estimated 
for this rulemaking.

A. Compliance Costs for Listings Including LDR Impacts and the 
Exclusion for Oil-Bearing Hazardous Secondary Materials

    This Section describes (1) the universe of petroleum refineries and 
volumes of petroleum refining wastes in the four waste groups listed, 
including LDR impacts, (2) an overview of the industry impact 
methodology, later described in detail, and detail of the methodology 
for determining incremental compliance cost, (3) the potential remedial 
action costs, and (4) a summary of incremental compliance cost results.
1. Universe of Petroleum Refineries and Waste Volumes
    In order to estimate costs, it was first necessary to estimate 
total annual generation of petroleum refining wastes. The domestic 
petroleum refining industry affected by this ruling is composed of 162 
refineries owned/operated by 80 companies. The quantity of waste at the 
point of generation (i.e., entering the waste management system) could 
range from 91,600 to 177,900 metric tons per year, with an expected 
value of approximately 134,800 metric tons per year.27
---------------------------------------------------------------------------

    \27\ Waste quantity estimates for the point of generation and 
final management are presented in Table 3.3 of Document 1 of the 
``Background Documents for the Cost and Economic Impact Analysis of 
Listing Four Petroleum Refining Wastes as Hazardous Under RCRA 
Subtitle C,'' January 10, 1998.
---------------------------------------------------------------------------

2. Methodology for Estimating Industry Economic Impact and Incremental 
Compliance Cost

Industry Impact, Overview

    Partial equilibrium analysis, as was noted, was used to evaluate 
possible changes in market demand, estimate the post-control shift in 
market supply, predict the change in market equilibrium (price and 
quantity), and estimate plant closures. Petroleum refineries produce 
several hundred products. The economic impact analysis evaluates the 
impact of the listings based on ten petroleum products (i.e., ethane/
ethylene, butane/butylene, normal butane/butylene, isobutane/
isobutylene, finished motor gasoline, jet fuel, distillate and residual 
fuel oil, asphalt, and petroleum coke), which represented 91 percent of 
domestically refined petroleum products in 1992. Because compliance 
costs for the hazardous waste listings cannot be allocated to any 
specific products, output in the partial equilibrium model is defined 
as a composite, bundled product equal to the sum of price

[[Page 42177]]

multiplied by the weighted production volumes of all ten products.
    Due to the wide range of potential costs, as shown in the table at 
the end of this section, a bounding analysis was conducted to evaluate 
the maximum potential industry economic impact of this listing 
determination. Highest cost options bounded the industry economic 
impact analysis. The upper bound LDR Scenario assumes a pretreatment 
management method of solidification prior to Subtitle C landfill for 
metal-based wastes, combustion in a Subtitle C incinerator/BIF for 
organic-based wastes, and a listing exemption granted for organic-based 
wastes that are recycled to a coker. The lower bound LDR Scenario uses 
the same assumptions except on-site incineration costs are assumed for 
those refineries generating sufficient quantities to warrant 
construction of an incinerator. EPA's judgement that industry impact is 
minimal is based on upper-bound costs to the industry.

Incremental Compliance Cost

    EPA's approach to the compliance cost analysis for this rule was to 
compare the cost of current management practices, as reported in the 
RCRA section 3007 Questionnaire of petroleum refineries, with the 
projected cost of management to comply with the RCRA Subtitle C 
hazardous waste program. This difference in cost, when annualized 
28, represents the incremental annual compliance cost 
attributable to the rule.
---------------------------------------------------------------------------

    \28\ Costs are discounted at a rate of 7 percent over a 20-year 
period.
---------------------------------------------------------------------------

    Three scenarios are evaluated in this Cost and Economic Impact 
Analysis. The first scenario, Listing Scenario, assesses the costs 
incurred by the petroleum refining industry to comply with Subtitle C 
regulation excluding LDR regulations. The Listing Scenario assumes an 
end disposal management of Subtitle C landfilling or continued 
combustion of wastes, where indicated as the baseline management 
practice, in a Subtitle C incinerator/BIF.
    The second scenario, LDR Scenario, expands on the Listing Scenario 
by adding in cost impacts attributable to LDR regulations. Two options 
are assessed for the LDR Scenario. In Option 1, the upper-bound 
estimate, oil-based crude oil storage tank sediment (K169) and CSO 
sediment (K170) are combusted in off-site Subtitle C incinerators and 
spent hydrotreating and hydrorefining catalysts (K171, K172, 
respectively) are combusted in off-site incinerators followed by 
vitrification and Subtitle C landfill of the ash. In Option 2, the 
lower-bound estimate, oil-based crude oil storage tank sediment (K169) 
and CSO sediment (K170) are assumed to be managed in on-site Subtitle C 
incinerators for those refineries generating sufficient quantities and 
currently in the RCRA permitting program (thereby avoiding potential 
corrective action costs). Spent hydrotreating and hydrorefining 
catalysts (K171, K172) are assumed to be regenerated/reclaimed in RCRA-
exempt off-site metal recovery units.29 Compliance with LDR 
requirements is presumed to be mandatory.
---------------------------------------------------------------------------

    \29\ These cost estimates are presented in Document 1 of the 
``Background Documents for the Cost and Economic Impact Analysis of 
Listing Four Petroleum Refining Wastes as Hazardous Under RCRA 
Subtitle C,'' January 10, 1998.
---------------------------------------------------------------------------

    The third scenario, Oil-Bearing Exclusion Scenario, modifies the 
Listing and LDR Scenarios by assuming the refinery will process crude 
oil storage tank sediment (K169) and CSO sediment (K170) in coking 
units where it is more cost-effective than Subtitle C management. Two 
options are assessed for the Oil-Bearing Exclusion Scenario. In Option 
1, the upper-bound estimate, crude oil storage tank sediment (K169) and 
CSO sediment (K170) are processed in on-site and intracompany (i.e., 
``same company'') coking units when it is more economical than 
management in off-site Subtitle C incinerators. In Option 2, the lower-
bound estimate, crude oil storage tank sediment (K169) and CSO sediment 
(K170) are processed in intercompany (i.e., ``not same company'') 
coking units when it is technically feasible and/or more economical 
than management in off-site incinerators. ``Not same company'' costs 
are lower because more companies will avail themselves of this option 
if permitted to do so. Spent hydrotreating and hydrorefining catalysts 
(K171, K172, respectively) are combusted in off-site incinerators 
followed by vitrification and Subtitle C landfill of the 
ash.30
---------------------------------------------------------------------------

    \30\ These cost estimates are presented in Document 5 of the 
``Background Documents for the Cost and Economic Impact Analysis of 
Listing Four Petroleum Refining Wastes as Hazardous Under RCRA 
Subtitle C,'' January 10, 1998.
---------------------------------------------------------------------------

Baseline or Current Management Scenario

    Relying on 3007 Questionnaire responses and engineering site 
visits, EPA was able to determine the current (i.e., 1992) management 
practices for the handling and disposal of petroleum refining wastes. 
Current management practices varied among facilities and waste streams, 
and included such practices as on-/off-site Subtitle C/D landfill, off-
site Subtitle C incinerator/BIF, on-site surface impoundment, 
recycling, recovery, regeneration, and reclamation. These ``current'' 
management practices at each facility represent the baseline scenario 
of the analysis.
    As part of the 3007 Questionnaire, EPA asked each facility to 
identify current costs for the management of petroleum refining wastes. 
For this analysis, EPA relied on and has not changed the industry's own 
waste-specific estimates concerning the cost of current management. 
Industry average unit costs were developed for each baseline management 
practice from the 3007 Questionnaire data. EPA estimated costs for 
baseline management practices when limited or no cost data were 
provided in the 3007 Questionnaire. These calculated industry average 
and estimated unit costs were used when a facility did not provide its 
own unit cost estimates. EPA realizes that future events such as waste 
minimization efforts or increased demand for refinery products may 
change waste generation volumes and, thus, future waste management 
costs.31 It is important to note that EPA also estimated 
missing quantities to associate costs with these quantities.
---------------------------------------------------------------------------

    \31\ Baseline unit cost estimates are presented in Tables 3.8 
and 3.10 of Document 1 in the ``Background Documents for the Cost 
and Economic Impact Analysis of Listing Four Petroleum Refining 
Wastes as Hazardous Under RCRA Subtitle C,'' January 10, 1998.
---------------------------------------------------------------------------

Post-Regulatory Management Scenarios

    In predicting how industry would comply with the listing of 
petroleum refinery wastes as RCRA hazardous wastes, EPA developed the 
three post-regulatory management scenarios, previously noted, that 
represent reasonable management reactions on the part of industry. 
Details of the compliance assumptions are presented by baseline 
management practice in Table X-1. EPA developed these post-regulatory 
management categories based on knowledge of current waste management 
and the physical and chemical properties of the wastes. These scenarios 
are further described as follows:

    The ``Listing'' Scenario assumes an end disposal management 
method of Subtitle C landfill or continued combustion of wastes, 
where indicated as the baseline management practice, in a Subtitle C 
incinerator/BIF. The use of the word ``Listing'' is intended to 
emphasize that this scenario embodies only Subtitle C costs.
    The LDR Scenario presents two options. In the first option, the 
metal-based spent catalyst wastes are combusted in a Subtitle C 
incineration followed by vitrification, and Subtitle C landfill of 
the ash and the oil-based sediment wastes are combusted in off-

[[Page 42178]]

site Subtitle C incinerator/BIF units. This option reflects the 
highest cost situation of all those examined. Other technologies may 
be applicable (e.g., solvent extraction instead of incineration or 
solidification instead of vitrification for metal-based wastes) to 
meet LDR standards, but these are lower cost options and will not 
provide an upper-bound to the cost and economic analysis. In the 
second option, the spent hydrotreating and hydrorefining catalysts 
(K171, K172, respectively) are reclaimed/recovered to take advantage 
of the recycling exemption under RCRA Subtitle C regulation. 
However, recordkeeping, storage, and transportation activities are 
regulated under RCRA Subtitle C, while no LDR treatment costs are 
included. The oil-based wastes are combusted in either an on- or 
off-site Subtitle C incinerator/BIF depending on the economic 
feasibility of constructing on-site incinerator units. If a facility 
does not currently have a RCRA Part B permit, EPA assumed the 
facility would choose not to construct an on-site incinerator in 
order to avoid incurring potential costs under the RCRA corrective 
action program.
    The Oil-Bearing Exclusion Scenario also presents two options. 
Because of the uncertainty regarding plant-specific coker capacity 
availability, access limitations, cost limitations, feedstock 
quality limitations, and State regulatory restrictions, the two 
options given in Table X-2 were evaluated to bound the possible 
results of the LDR scenarios with an oil-bearing exclusion. Refiners 
will seek new cost optimization solutions since coking is now 
economical when compared to Subtitle C management instead of 
Subtitle D management. The first cost option considers that, when 
economical, facilities will transport crude oil storage tank 
sediment (K169) and CSO sediment (K170) to the nearest refinery 
within the same company (i.e., intracompany) that currently operates 
a coker. As a lower-bound cost option, it is assumed that technology 
allowing insertion of de-oiled crude oil storage tank sediment 
(K169) and CSO sediment (K170) into coker feedstocks will be 
developed and intercompany transfers will occur, without the 
transferring company paying the receiving company for the right to 
avoid Subtitle C costs. However, it is not likely that there will be 
no market pricing given potential profits (compared to Subtitle C 
management costs) and potential benefits received by both the 
generator and recycler; thus the lower bound.

    Incremental compliance costs are determined for each management and 
transportation practice by subtracting the baseline management cost 
from the compliance management cost. For example, the incremental unit 
compliance cost for wastes currently managed in off-site municipal 
Subtitle D landfills that now will be managed in Subtitle C landfills 
is $202/MT ($260/MT--$58/MT). This incremental unit cost is then 
multiplied by the quantity of waste generated by the facility to 
estimate the total incremental compliance cost. 32 Note that 
from Table X-2 it is possible to select various mixes of compliance 
options. For this rulemaking, EPA believes that the 2 right hand 
columns bound the compliance costs. However, Option 1 (LDR Scenario) 
was used in developing the worst case industry impact analysis.
---------------------------------------------------------------------------

    \32\ Compliance unit cost estimates are presented in Table 3.9 
and 3.10 of Document 1 in the ``Background Documents for the Cost 
and Economic Impact Analysis of Listing Four Petroleum Refining 
Wastes as Hazardous Under RCRA Subtitle C,'' January 10, 1998.

              Table X-1.--Baseline vs. Compliance Practices             
------------------------------------------------------------------------
                                                         Compliance     
 Baseline management practice     Wastes managed        assumptions     
------------------------------------------------------------------------
Storage Methods:                                                        
    Tank......................  K169--crude oil    Upgrade to Subtitle C
                                 storage tank       accumulation tank   
                                 sediment K170--    system.a            
                                 CSO sediment                           
                                 K171--spent                            
                                 hydrotreating                          
                                 catalyst K172--                        
                                 spent                                  
                                 hydroreffining                         
                                 catalyst.                              
    Container (e.g., drum)....  K169, K170, K171,  Upgrade to Subtitle C
                                 and K172.          accumulation        
                                                    container storage   
                                                    area.(a)            
    Pile......................  K169, K170, and    Construct new        
                                 K172.              Subtitle C          
                                                    accumulation tank   
                                                    storage system.(b)  
    Roll-on/Roll-off Bin......  K169, K170, K171,  Upgrade to Subtitle C
                                 and K172.          accumulation        
                                                    container storage   
                                                    area.(a)            
    Other.....................  K169, K170, K171,  Assume most common   
                                 and K172.          storage type        
                                                    reported by the     
                                                    industry for that   
                                                    waste type.         
Treatment methods:                                                      
    On-site Industrial Furnace  K170.............  In compliance. Add   
                                                    RCRA Part 264 and   
                                                    270 administrative  
                                                    costs to permit     
                                                    unit.               
    Other On-site Thermal       K169.............  On-site industrial   
     Treatment.                                     furnace.            
    Off-site Incineration.....  K169 and K171....  In compliance.       
                                                    Construct a new on- 
                                                    site Subtitle C     
                                                    incinerator if more 
                                                    economical than off-
                                                    site management.    
    Washing with Distillate...  K169 and K170....  Upgrade to Subtitle C
                                                    accumulation tank   
                                                    system. (a)         
    Washing with Water........  K169.............  Upgrade to Subtitle C
                                                    accumulation tank   
                                                    system.(a)          
    Other Cleaning/Extraction.  K171 and K172....  Upgrade to Subtitle C
                                                    accumulation tank   
                                                    system.(a)          
    Sludge Thickening.........  K169 and K170....  Upgrade to Subtitle C
                                                    accumulation tank   
                                                    system.(a)          
    Sludge De-watering........  K169 and K170....  Upgrade to Subtitle C
                                                    accumulation tank   
                                                    system.(a)          
    Settling..................  K169 and K170....  Upgrade to Subtitle C
                                                    accumulation tank   
                                                    system.(a)          
    Filtration................  K169 and K170....  Upgrade to Subtitle C
                                                    accumulation tank   
                                                    system.(a)          
    Pressure Filtration/        K169 and K170....  Upgrade to Subtitle C
     Centrifuging.                                  accumulation tank   
                                                    system for existing 
                                                    units.(a) Construct 
                                                    a new on-site       
                                                    Subtitle C pressure 
                                                    filtration/         
                                                    centrifuge unit for 
                                                    a waste minimization
                                                    opportunity for oily
                                                    sludges.(b)         
    Chemical Emulsion Break...  K169.............  Upgrade to Subtitle C
                                                    accumulation tank   
                                                    system.(a)          
    Thermal Emulsion Break....  K169 and K170....  Upgrade to Subtitle C
                                                    accumulation tank   
                                                    system.(a)          
    Other Phase Separation....  K169, K171, and    Upgrade to Subtitle C
                                 K172.              accumulation tank   
                                                    system.(a)          

[[Page 42179]]

                                                                        
    On-site Land treatment....  K169, K170, and    Listing Scenario:    
                                 K171.              Abandon on-site land
                                                    treatment unit and  
                                                    dispose waste in off-
                                                    site Subtitle C     
                                                    landfill.           
                                                   LDR Scenario: K169/  
                                                    K170--On-/Off-site  
                                                    incineration;       
                                                   K171--Option 1: Off- 
                                                    site incineration   
                                                    and ash             
                                                    vitrification;      
                                                    Option 2: Transfer  
                                                    precious or non-    
                                                    precious metal      
                                                    catalysts for       
                                                    reclamation or      
                                                    regeneration.       
    Off-site Land treatment...  K169 and K170....  Listing Scenario: Off-
                                                    site Subtitle C     
                                                    landfill.           
                                                   LDR Scenario: On-/Off-
                                                    site incineration.  
    Discharge to On-site WWT    K169 and K170....  In compliance due to 
     Facility.                                      the headwaters      
                                                    exemption for       
                                                    wastewaters         
                                                    discharged to NPDES 
                                                    or POTW.            
    Drying on a Pad...........  K169 and K170....  Construct new        
                                                    Subtitle C          
                                                    accumulation tank   
                                                    system. (b)         
    On-site Oxidation of        K171 and K172....  Upgrade to Subtitle C
     Pyrophoric Material.                           accumulation tank   
                                                    system. (a)         
    On-site Stabilization.....  K169, K170, K171,  Upgrade to Subtitle C
                                 and K172.          accumulation tank   
                                                    system. (a)         
    Off-site Stabilization....  K171.............  Listing Scenario: In 
                                                    compliance.         
                                                   LDR Scenario: Ash    
                                                    vitrification       
                                                    following off-site  
                                                    incineration.       
    Other Treatment...........  K169.............  Upgrade to Subtitle C
                                                    accumulation tank   
                                                    system. (a)         
Transfer Methods:                                                       
    Transfer of Precious or     K171 and K172....  Reclamation/         
     Nonprecious Metal                              regeneration        
     Catalysts for Reclamation/                     facility will       
     Regeneration.                                  increase Subtitle C 
                                                    storage capacity and
                                                    upgrade to Subtitle 
                                                    C transportation and
                                                    management.         
    Transfer to Non-Petroleum   K169 and K170....  Off-site Subtitle C  
     Refinery for Direct Use                        BIF.                
     as a Fuel or to Make a                                             
     Fuel.                                                              
    Transfer for Use as an      K169.............  Off-site Subtitle C  
     Ingredient in Products                         BIF.                
     that are Placed on the                                             
     Land.                                                              
    Transfer to Other Off-site  K169 and K171....  Assume most common   
     Entity.                                        reported transfer   
                                                    method reported by  
                                                    industry for each   
                                                    waste type.         
Disposal methods:                                                       
    NPDES.....................  K169.............  In compliance.       
    Off-site Municipal          K169, K170, and    Listing Scenario: Off-
     Subtitle D Landfill.        K171.              site Subtitle C     
                                                    landfill.           
                                                   LDR Scenario: On-/Off-
                                                    site incineration.  
    Off-site Industrial         K169, K170, K171,  Listing Scenario: Off-
     Subtitle D Landfill.        and K172.          site Subtitle C     
                                                    Landfill.           
                                                   LDR Scenario: On-/Off-
                                                    site incineration.  
    Off-site Subtitle C         K169, K170, K171,  Listing Scenario: In 
     Landfill.                   and K172.          compliance.         
                                                   LDR Scenario: K169/  
                                                    K170--On-/Off-site  
                                                    incineration;       
                                                   K171/K172--Option 1: 
                                                    Off-site            
                                                    incineration        
                                                    followed by ash     
                                                    vitrification;      
                                                    Option 2: Transfer  
                                                    precious or         
                                                    nonprecious metal   
                                                    catalysts for       
                                                    reclamation or      
                                                    regeneration.       
    On-site Subtitle D          K170, K171, and    Listing Scenario: Off-
     Landfill.                   K172.              site Subtitle C     
                                                    landfill.           
                                                   LDR Scenario: K170-- 
                                                    On-/Off-site        
                                                    incineration;       
                                                   K171/K172--Option 1: 
                                                    Off-site            
                                                    incineration        
                                                    followed by ash     
                                                    vitrification;      
                                                    Option 2: Transfer  
                                                    precious or         
                                                    nonprecious metal   
                                                    catalysts for       
                                                    reclamation or      
                                                    regeneration.       
    On-site Subtitle C          K169, K171, and    Listing Scenario: In 
     Landfill.                   K172.              compliance.         
                                                   LDR Scenario: K169-- 
                                                    On-/Off-site        
                                                    incineration;       
                                                   K171/K172--Option 1: 
                                                    Off-site            
                                                    incineration        
                                                    followed by ash     
                                                    vitrification;      
                                                    Option 2: Transfer  
                                                    precious or         
                                                    nonprecious metal   
                                                    catalysts for       
                                                    reclamation or      
                                                    regeneration.       
    On-site Surface             K169.............  Dredge impoundment   
     Impoundment.                                   sludge and dispose  
                                                    in off-site Subtitle
                                                    D Landfill prior to 
                                                    final listing and   
                                                    then recommission   
                                                    impoundment for non-
                                                    hazardous waste use;
                                                    Upgrade existing on-
                                                    site filtration     
                                                    system to a Subtitle
                                                    C accumulation      
                                                    system for sludge   
                                                    management.(a)      
                                                   Listing Scenario: Off-
                                                    site Subtitle C     
                                                    landfill.           
                                                   LDR Scenario: On-/Off-
                                                    site incineration.  
------------------------------------------------------------------------
 (a)Management costs (i.e., operation and maintenance costs) for        
  baseline and compliance are the same for this management method.      
  Secondary containment is included where appropriate.                  
(b) Management costs (i.e., O&M costs) for baseline and compliance are  
  the same for this management method. Secondary containment is included
  where appropriate. The compliance cost will involve closure of the    
  drying pad and construction of a drying tank system with secondary    
  containment.                                                          

3. Potential Remedial Action Costs Within the Refining Industry
    In addition to the refinery waste management costs themselves, the 
petroleum refining hazardous waste listing could affect the management 
of soils, leachates, groundwater, and remedial materials. The Agency's 
``contained in'' policy defines certain remediation wastes 
``containing'' a listed hazardous waste as a RCRA hazardous waste (see 
Chemical Waste Management v. EPA, 869 F.2d 1526, D.C.C, 1989). Industry 
sites where newly identified hazardous wastes have been managed prior 
to the effective date of the new listings may still have contaminant 
concentrations which exceed ``contained in'' levels. Any firm actively 
managing such material could become a generator of RCRA hazardous

[[Page 42180]]

waste. Releases from all solid waste management units at these TSDFs, 
including those that in the future would be found to contain a waste 
meeting the petroleum listing descriptions, are covered by facility-
wide corrective action under 40 CFR 264.101. Associated costs, e.g., 
RCRA Facility Assessment, were addressed in the draft proposed 
corrective action rule.
4. Summary of Compliance Cost Results
    Table X-2 presents a summary of estimated incremental annualized 
compliance costs for each waste due to (1) listing, (2) listing 
including potential LDR pre-treatment regulations, and (3) listing 
including LDR impacts and oil-bearing exclusion cost benefits.
    Under the oil-bearing exclusion scenarios, the expected value 
represents recycling of 65 percent of the oil-based crude oil storage 
tank sediment (K169) and CSO sediment (K170) in either on-site coking 
units or intracompany transfers when it is economically feasible, off-
site incineration of the remaining 35 percent of the oil-based crude 
oil storage tank sediment (K169) and CSO sediment (K170) quantity, and 
off-site incineration and vitrification of the spent hydrotreating and 
hydrorefining catalysts. It is estimated that 65 percent of the oil-
based crude oil storage tank sediment (K169) and CSO sediment (K170) 
quantity is recycled into coking units.
    All of the above cost estimates, under each scenario, assume 
implementation of waste minimization for filtering ``oily'' crude oil 
storage tank sediment (K169) and CSO sediment (K170) and recycling the 
oil filtrate back into process units. Revenues from the recycled oil 
are roughly estimated at about $1 million per year but are not included 
as an offset to costs in this table.

                                                        Table X-2.--Summary of Cost of Compliance                                                       
                                                              (1997 $millions per Year) 1,2                                                             
                                                                                                                                                        
                                                                                                            Oil-Bearing Exclusion  Oil-Bearing Exclusion
                                                                                                              Scenario Including     Scenario Including 
                                                              LDR Scenario  Option                          LDR Impact  Option 1-- LDR Impact  Option 2--
                                                                   1--Off-site        LDR Scenario  Option    De-oil K169, K170,     De-oil D169, K170, 
                                                                 Incineration of        2--On-/Off-site      ``Not Same Company''     ``Same Company''  
            Waste stream                Listing Scenario     K169,K170 and Off-site  Incineration of K169,   Recycling to Coker,    Recycling to Coker, 
                                                                Incineration and     K170 and Regeneration  Off-site Incineration  Off-site Incineration
                                                             Vitrification of K171,    or Reclamation of     of Remaining Sludge,   of Remaining Sludge,
                                                                      K172                K171, K172 3       and Regeneration or    and Regeneration or 
                                                                                                             Reclamation of K171,   Reclamation of K171,
                                                                                                                    K172 4                 K172 4       
                                     Average Cost [Low-      Average Cost [Low-      Average Cost [Low-     Average Cost [Low-     Average Cost [Low-   
                                      High].                  High].                  High].                 High].                 High]               
--------------------------------------------------------------------------------------------------------------------------------------------------------
Crude Oil Storage Tank Sediment....  2.5 [1.1-4.4].........  24.1 [10.4-43.3]......  18.6 [9.0-31.6]......  8.7 [4.1-14.9].......  13.0 [5.9-22.6].     
Clarified Slurry Oil Sediment......  3.1 [1.6-5.4].........  25.1 [12.5-42.0]......  18.8 [10.5-29.6].....  8.1 [3.9-13.8].......  13.5 [6.8-22.4].     
Spent Hydrotreat- ing Catalyst.....  1.5 [0.9-3.2].........  5.6 [3.9-8.5].........  2.6 [1.3-5.0]........  2.6 [1.3-5.0]........  2.6 [1.3-5.0].       
Spent Hydrorefining Catalyst.......  1.7 [0.8-4.2].........  13.0 [9.3-18.4].......  4.4 [2.1-8.8]........  4.4 [2.1-8.8]........  4.4 [2.1-8.8].       
RCRA Administrative Costs..........  0.6 [0.4-0.7].........  0.6 [0.4-0.8].........  0.9 [0.7-1.1]........  0.6 [0.4-0.8]........  0.6 [0.4-0.8].       
      Total........................  9.4 [4.8-17.9]........  68.4 [36.5-113.0].....  45.3 [23.6-76.1].....  24.4 [11.8-43.3].....  34.1 [16.5-59.6].    
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Cost uncertainty (Low-High) is estimated using a +/-50% adjustment of any estimated quantities and a +/-25% adjustment of any estimated costs.      
  Management practices and transportation unit costs were provided in the 1992 RCRA 3007 Questionnaire responses. If unit costs were not reported, an   
  industry-based average unit cost was used. If data were not available to derive an industry-based average, EPA estimated a unit cost for the          
  management practice based on previous listing determinations, land disposal restrictions analyses, and engineering cost documents. Compliance         
  management practice, transportation, and RCRA administrative unit costs, prices, and cost equations were obtained from industry-based averages derived
  from the 1992 RCRA 3007 Questionnaire, previous listing determinations and land disposal restrictions analyses, and engineering cost documents.       
2 In the analysis, 1992 costs were inflated to 1997 dollars using an inflation factor of 1.11657. The inflation factor is based on Engineering News-    
  Record construction (25% weighted) and common labor (75% weighted) cost indexes. The inflation factor is weighted towards labor factors because       
  compliance costs are more operational in function. Costs are annualized assuming a discounted rate of 7% over a 20-year period.                       
3 On-site incinerators are assumed only for those facilities that manage a large enough quantity of waste so that an on-site incinerator is more        
  economical for the facility and which are currently in the RCRA program. All other facilities are assumed to continue managing wastes off-site.       
4 All crude oil storage tank sediment (K169) and CSO sediment (K170) wastes are assumed to be de-oiled in the cost estimate. The recovered oil is       
  recycled back into process units. For those refineries that reported oil recovery fractions, that data were used. For refineries that did not provide 
  data, using an industry average for crude oil storage tank sediment (K169) and CSO sediment (K170), 60 percent of the quantity entering the filtration
  unit is assumed to be recovered as oil and the remaining 40 percent goes on for further management. Of the remaining de-oiled sediment quantity (i.e.,
  40 percent fraction), 65 percent is assumed to be recycled into coking units. The remaining 35 percent is subject to Subtitle C management. If crude  
  oil storage tank sediment (K169) and CSO sediment (K170) are recycled into coking units, they are assumed to be subject to the oil-bearing exclusion. 
  Therefore, all storage, treatment, and transportation of these wastes are not subject to RCRA Subtitle C regulation. Option 1 reflects management of  
  crude oil storage tank sediment (K169) and CSO sediment (K170) in coking units owned by any company (i.e., ``not same company''). Option 2 reflects   
  management of crude oil storage tank sediment (K169) and CSO sediment (K170) in coking units as an option only within those companies that own them   
  (i.e., ``same company'').                                                                                                                             

B. Details of Industry Economic Impact

    As noted, a partial equilibrium model was used to estimate primary 
and secondary impacts from implementation of the listings. Primary 
economic impacts include changes in market equilibrium price and output 
levels, changes in the value of shipments or revenues to domestic 
producers, and plant closures. Secondary impacts include changes in 
employment, use of energy inputs, balance of trade, and regional 
refinery distribution. Impacts associated with the two Oil-Bearing 
Exclusion compliance scenarios will fall

[[Page 42181]]

between the range of primary and secondary economic impacts predicted 
for the Listing and LDR compliance scenarios as shown in Table X-2 (the 
low and high cost scenarios).
    Predicted price increases and reductions in domestic output are 
less than 1 percent for the ten products evaluated under both the 
Listing and LDR compliance scenarios.33 The projected 1992 
price increase for the ten products combined ranges from 0.03 to 0.76 
percent under the low- and high-cost scenarios, 
respectively.34 Under the low- and high-cost scenarios, 1992 
production is expected to decrease, ranging from 1.3 to 30.9 million 
barrels per year, representing a 0.02 to 0.59 percent decrease in 
annual production, respectively. The value of shipments or revenues for 
domestic producers are expected to increase for the ten products 
combined, ranging from $9.0 to $213 million (1992 dollars) annually for 
the low- and high-cost scenarios, respectively. This revenue increase 
results given that the percent increase in price exceeds the percent 
decrease in quantity for goods with inelastic demand. The model 
estimates that up to two refineries may close as a result of the 
predicted decrease in production under both regulatory scenarios. Those 
refineries with the highest per unit control costs are assumed to be 
marginal in the post-control market. No significant regional impacts 
are anticipated from implementation of the listings since only up to 
two facilities are anticipated to close and impacts overall are 
estimated to be minimal. Primary economic impacts are not anticipated 
to be significantly different in the later years of this decade and 
even beyond (even though 1992 data were used herein) in that the 
industry is mature and not one that changes often or dramatically 
absent an external shock.
---------------------------------------------------------------------------

    \33\ The ten petroleum products include ethane/ethylene, butane/
butylene, normal butane/butylene, isobutane/isobutylene, finished 
motor gasoline, jet fuel, distillate and residual fuel oil, asphalt, 
and petroleum coke.
    \34\ Similar percentage increases would apply to current prices.
---------------------------------------------------------------------------

    Under the low- and high-cost scenarios, the number of workers 
employed in 1992 by firms in SIC 2911 are estimated to decrease ranging 
from 12 to 282 workers annually, representing a 0.03 and 0.59 percent 
decrease in total employment, respectively. The small magnitude of 
predicted job loss directly results from the relatively small decrease 
in production anticipated and the relatively low labor intensity in the 
industry. An estimated decrease in energy use ranging from $1.02 to 
$24.32 million ($1992) per year is expected for the industry, under the 
low- and high-cost scenarios, respectively. As production decreases, 
the amount of energy input utilized by the refining industry also 
declines. The change in energy use does not consider the increased 
energy use associated with operating and maintaining the regulatory 
control equipment due to the lack of available data. Finally, 
imposition of the listings will further increase the negative balance 
of trade. Under the low- and high-cost scenarios, net exports are 
anticipated to decline ranging from 0.2 to 4.7 million barrels per 
year, representing a 0.1 and 2.8 percent decline, respectively. The 
dollar value of the total decline in net exports ranges from $6.35 to 
$152.6 million ($1992) per year. Given the magnitude of the estimated 
compliance costs, refineries are expected to incur minimal economic 
impacts. Secondary economic impacts are not anticipated to be 
significantly different in 1997.
    Economic impacts may be slightly underestimated as a result of the 
following model input changes:

    The economic analysis was based on a lower CSO sediment quantity 
estimate of 9,000 MT/yr managed in final management practices. This 
quantity was revised to 13,100 MT/yr. As a result, impacts for 
facilities generating this sediment are underestimated for all 
scenarios.
    The regulatory options (i.e., waste management options) used to 
evaluate economic impacts differ slightly from those that were used 
to calculate the cost of compliance for the lower- and upper-bound 
LDR Scenarios, such that waste management costs were understated by 
$3 and $31 million ($1992), respectively. As a result, economic 
impacts may be understated for the lower-and upper-bound LDR 
Scenarios. However, the Oil-Bearing Exclusion Scenario, with 
estimated costs from $31 to $67 million ($1992) and an expected 
value of $45 million, fall within the range of costs used in the 
economic impact analysis for the LDR Scenarios. Therefore, the 
lower-and upper-bound LDR Scenarios bound the anticipated cost of 
the rule (i.e., the Oil-Bearing Exclusion Scenario).

    Economic impacts may be overestimated as a result of the following 
model assumptions:

    The model assumes that all refineries compete in a national 
market. In reality, some refineries are protected from market 
fluctuations by regional or local trade barriers and may therefore 
be less likely to feel impact.
    The total cost of compliance is assigned exclusively to ten 
petroleum products, rather than the entire product slate for each 
refinery.
    Some refineries may find it profitable to expand production in 
the post-control market. This would occur when a firm found its 
post-control incremental unit cost to be smaller than the post-
control market price. Expansion by these firms would result in a 
smaller decrease in output and increase in price than otherwise 
would occur.
    The economic analysis was initially based on the listing of five 
waste streams including unleaded gasoline sediment, which has since 
been removed from the list of wastes included in this listing 
determination. As a result, economic impacts for the 98 facilities 
generating unleaded gasoline sediment will be overestimated.
    With the combined effects of analyzing five waste streams and 
using a lower CSO sediment quantity and a less costly upper-bound 
LDR Scenario management option, the total cost of compliance for the 
Listing Scenario is understated by $2 million and the lower-bound 
and upper-bound LDR Scenarios are understated by $5 million and $31 
million ($1992), respectively. As a result, economic impacts may be 
understated for the Listing and LDR Scenarios. However, as noted, 
economic impacts estimated for the Listing and LDR scenarios bound 
the anticipated economic impacts associated with the Oil-Bearing 
Exclusion Scenario.

    Under any realistic set of assumptions associated with this 
listing, industry economic impact is likely to be very slight. The 
results of the economic impact analysis are summarized in Table X-3.

            Table X-3.--Summary of Economic Impacts \1\, \2\            
------------------------------------------------------------------------
                                     Listing        LDR          LDR    
         Economic impacts            scenario     scenario     scenario 
                                   lower-bound  lower-bound  upper-bound
------------------------------------------------------------------------
                        Primary Economic Impacts                        
------------------------------------------------------------------------
Average Price Increase:                                                 
    Over All Products............        0.03%        0.08%        0.76%

[[Page 42182]]

                                                                        
Annual Production Decrease:                                             
    Amount (MMbbl)...............        (1.3)       (3.27)      (30.93)
    Percentage Change............      (0.03%)      (0.06%)      (0.59%)
Annual Value of Shipments                                               
    Amount (MM$92)...............         $9.0       $22.59      $213.34
    Percentage Change............        0.01%       00.02%        0.16%
Number of Plant Closures.........          0-2          0-2          0-2
------------------------------------------------------------------------
                       Secondary Economic Impacts                       
------------------------------------------------------------------------
Annual Job Loss:.................                                       
    Number.......................         (12)         (30)        (282)
    Percentage Change............      (0.03%)      (0.06%)      (0.59%)
Annual Decrease In Energy Use:                                          
    Amount (MM$92)...............      ($1.02)      ($2.57)     ($24.32)
    Percentage Change............      (0.03%)      (0.06%)      (0.59%)
Annual Net Foreign Trade Loss:                                          
    Amount (MMbbl)...............       (0.20)       (0.49)       (4.70)
    Percentage Change............      (0.12%)       (0.3%)       (2.8%)
    Dollar Value ($/MMbbl).......      ($6.35)     ($15.96)   ($152.60) 
------------------------------------------------------------------------
\1\ Assumes listing of five waste streams: crude oil storage tank       
  sediment, clarified slurry oil sediment, unleaded tank sediment, spent
  hydrotreating catalyst, and spent hydrorefining catalyst. Unleaded    
  tank sediment was not listed. Impact will be reduced with four.       
\2\ The analysis was conducted using 1992 cost and price data. Costs and
  prices were not inflated to 1997 dollars and the economic impact      
  analysis was not revised because the economic impacts are not         
  anticipated to change significantly. Anticipated costs with the       
  granting of a oil-bearing exclusion fall within the range used in the 
  economic impact analysis.                                             

XI. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) of 1980 as amended by SBREFA 
requires Federal agencies to consider ``small entities'' throughout the 
regulatory process. EPA policy suggests that an initial screening 
analysis be performed to determine whether small entities will be 
affected by the regulation. If affected small entities are identified, 
regulatory alternatives should be considered which mitigate the 
potential impacts. Small entities as described in the Act are only 
those ``businesses, organizations and governmental jurisdictions 
subject to regulation.'' In addition, the Agency must prepare an IRFA, 
unless the head of the Agency certifies that the rule will not have a 
significant impact on a substantial number of small entities.
    The Small Business Administration (SBA) size standards criteria 
apply to firm size, whereas the economic impact analysis for this 
rulemaking was conducted at the facility level (i.e., refinery level). 
Few companies employ more than 1,500 employees, and data on the number 
of employees at company level were much less readily available than 
were capacity data. For single-plant firms, the SBA criteria were 
applied directly. For firms (i.e., companies) owning more than one 
refinery, crude capacity was aggregated for all plants (i.e., 
refineries) to determine the overall size of the company.35 
Despite the high percentage of small entities in the population of 
refinery companies affected by the listing determination, anticipated 
impacts as a result of implementation of the listings were minimal, 
with a maximum of two plant closures predicted under the most 
conservative assumptions used in each of the scenarios evaluated.
---------------------------------------------------------------------------

    \35\ According to ``EPA Guidelines for Implementing the 
Regulatory Flexibility Act'' (February, 1997) and the Small Business 
Size Regulations (13 CFR 121), any refinery that produces petroleum 
products (SIC 2911) of less than or equal to 75,000 barrels of crude 
per day and has no more than 1,500 employees, constitutes a ``small 
entity.'' The Agency believes that none of the entities which would 
incur incremental compliance costs as a result of this rulemaking 
produce more than 75,000 barrels and have less than 1,500 employees.
---------------------------------------------------------------------------

    Of the 66 affected companies, 32 entities fit the definition of a 
small entity as defined by the RFA. Table XI-1 presents the estimated 
annualized incremental compliance costs borne by the 32 small 
businesses in the petroleum refining industry. The annual incremental 
cost of the rule for the 32 facilities ranged from $4,566 to $11.8 
million (1992 dollars). For each of the 32 facilities impacted, these 
annual costs constitute less than 0.96 percent of total annual sales. 
EPA believes that these costs do not represent a significant impact. 
Hence, pursuant to section 605(b) of the RFA, 5 U.S.C. 605(b), the 
Administrator certifies that this rule will not have a significant 
economic impact on a substantial number of small entities.

XII. Submission to Congress and the General Accounting Office

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each House of the Congress and to the Comptroller General of the 
United States. EPA will submit a report containing this rule and other 
required information to the U.S. Senate, the U.S. House of 
Representatives, and the Comptroller General of the United States prior 
to publication of the rule in the Federal Register. This action is not 
a ``major rule'' as defined by 5 U.S.C. Sec. 804(2). This rule will be 
effective six months from the date of publication.

[[Page 42183]]



                         Table XI-1.--Results of the Regulatory Flexibility Analysis (a)                        
----------------------------------------------------------------------------------------------------------------
                                  Summary of economic impacts on small entities                                 
-----------------------------------------------------------------------------------------------------------------
                                                                       LDR scenario lower    LDR scenario upper-
                                                  Listing scenarios           bound                 bound       
----------------------------------------------------------------------------------------------------------------
Range of Annualized Compliance Costs..........       $4,566-$305,379     $4,556-$7,561,781    $4,556-$11,765,904
Range of Annual Company Refinery Sales........                                                                  
(2) $19,377,340-$1,218,936,710                                                                                  
Range of Annualized Compliance Costs as a                                                                       
 Percentage of Company Refinery Sales.........         0.001%-0.236%         0.001%-0.620%        0.001%-0.965% 
----------------------------------------------------------------------------------------------------------------
(a) The analysis was conducted using 1992 cost and price data. Costs and prices were not inflated to 1997       
  dollars and the analysis was not revised because the anticipated impacts would still be insignificant.        

XIII. Unfunded Mandates

    Under section 202 of the Unfunded Mandates Reform Act of 1995 
(``UMRA'') signed into law on March 22, 1995, The EPA must prepare a 
statement to accompany any rule where the estimated costs to State, 
local, or tribal governments, or to the private sector, will be $100 
million or more in any one year. Section 203 requires the epa to 
establish a plan for informing and advising any small governments that 
may be significantly or uniquely impacted by the rule.
    Under section 205, agencies also must develop a process to permit 
elected State, local, and tribal government officials to provide 
``meaningful and timely input'' into the development of regulatory 
proposals ``containing significant intergovernmental mandates.'' In 
addition, agencies must consider a ``reasonable number of regulatory 
alternatives'' and select the least costly, most cost-effective, or 
least burdensome alternative that achieves the objectives of the rule, 
unless the provisions of the alternative are inconsistent with the law 
or an explanation is provided by the head of the affected agency.
    EPA has determined that this rule does not include a Federal 
mandate that may result in estimated costs of $100 million or more to 
either State, local, or tribal governments in the aggregate or to the 
private sector. The rule would not impose any Federal intergovernmental 
mandate because it imposes no enforceable duty upon State, tribal, or 
local governments. States, tribes, and local governments would have no 
compliance costs under this rule, which applies only to facilities 
managing the listed petroleum production wastes. It is expected that 
States will adopt similar rules and submit those rules for inclusion in 
their authorized RCRA programs, but they have no legally enforceable 
duty to do so. For the same reasons, EPA also has determined that this 
rule contains no regulatory requirements that might significantly or 
uniquely affect small governments.
    In addition, as discussed above, the private sector is not expected 
to incur costs exceeding $100 million in any one year. The upper-bound 
of the range of potential average annual costs is estimated to be $60 
million ($1997) with the granting of an oil-bearing exclusion, 
considerably below the $100 million annual threshold. The Agency 
believes that this average annual cost represents the typical cost for 
any given year and that this rulemaking will not result in a spike in 
annual cost that might rise above $100 million in any given year above 
for the following reasons. First, compliance with these new 
requirements does not involve significant capital costs which could 
generate such a spike. Treatment and disposal capacity for these wastes 
already exist and the typical costs incurred come from treatment and 
disposal on a routine basis. Second, waste generation rates for these 
wastes are expected to be relatively constant over time. No signficant 
surge in generation of the wastes listed in this rule involving a 
concomitant increase in costs are anticipated.

XIV. Paperwork Reduction Act

    This rule does not contain any new information collection 
requirements subject to OMB review under the Paperwork Reduction Act of 
1995, 44 U.S.C. 3501 et seq. Facilities will have to comply with the 
existing Subtitle C recordkeeping and reporting requirements for the 
newly listed waste streams.
    To the extent that this rule imposes any information collection 
requirements under existing RCRA regulations promulgated in previous 
rulemakings, those requirements have been approved by the Office of 
Management and Budget (OMB) under the Paperwork Reduction Act, 44 
U.S.C. 3501 et seq., and have been assigned OMB control numbers 2050-
0009 (ICR no. 1573, Part B Permit Application, Permit Modifications, 
and Special Permits); 2050-0120 (ICR 1571, General Facility Hazardous 
Waste Standards); 2050-0028 (ICR 261, Notification of Hazardous Waste 
Activity); 2050-0034 (ICR 262, RCRA Hazardous Waste Permit Application 
and Modification, Part A); 2050-0039 (ICR 801, Requirements for 
Generators, Transporters, and Waste Management Facilities under the 
Hazardous Waste Manifest System); 2050-0035 (ICR 820, Hazardous Waste 
Generator Standards); and 2050-0024 (ICR 976, 1997 Hazardous Waste 
Report.
    Release reporting required as a result of listing wastes as 
hazardous substances under CERCLA and adjusting the RQs has been 
approved under the provisions of the Paperwork Reduction Act, 44 U.S.C. 
3501 et seq., and has been assigned OMB control number 2050-0046 (ICR 
1049, Notification of Episodic Release of Oil and Hazardous 
Substances).

XV. National Technology Transfer and Advancement Act

    Under Section 12(d) of the National Technology Transfer and 
Advancement Act, the Agency is directed to use voluntary consensus 
standards in its regulatory activities unless to do so would be 
inconsistent with applicable law or otherwise impractical. Voluntary 
consensus standards are technical standards (e.g., materials 
specifications, test methods, sampling procedures, business practices, 
etc.) that are developed or adopted by voluntary consensus standard 
bodies. Where available and potentially applicable voluntary consensus 
standards are not used by EPA, the Act requires the Agency to provide 
Congress, through the OMB, an explanation of the reasons for not using 
such standards.
    This rule does not establish any new technical standards and thus, 
the Agency has no need to consider the use of voluntary consensus 
standards in developing this final rule.

XVI. Executive Order 13045--Protection of Children From 
Environmental Health Risks and Safety Risks

    The Executive Order 13045 is entitled ``Protection of Children from

[[Page 42184]]

Environmental Health Risks and safety Risks (62 FR 19885, April 23, 
1997). This Order applies to any rule that EPA determines (1) is 
``economically significant'' as defined under Executive Order 12866, 
and (2) the environmental health or safety risk addressed by the rule 
has a disproportionate effect on children. If the regulatory action 
meets both criteria, the Agency must evaluate the environmental health 
or safety effects of the planned rule on children, and explain why the 
planned regulation is preferable to other potentially effective and 
reasonably feasible alternatives considered by the Agency
    This final rule is not subject to E.O. 13045 because this is not an 
economically significant regulatory action as defined by E.O. 12866.

List of Subjects

40 CFR Part 148

    Administrative practice and procedure, Hazardous waste, Reporting 
and recordkeeping requirements, Water supply.

40 CFR Part 261

    Environmental protection, Hazardous waste, Recycling, Reporting and 
recordkeeping requirements.

40 CFR Part 266

    Environmental protection, Boilers and industrial furnaces, Energy, 
Hazardous waste, Recycling, Reporting and recordkeeping requirements.

40 CFR Part 268

    Environmental protection, Hazardous waste, Reporting and 
recordkeeping requirements.

40 CFR Part 271

    Environmental protection, Administrative practice and procedure, 
Confidential business information, Hazardous materials transportation, 
Hazardous waste, Indians-lands, Intergovernmental relations, Penalties, 
Reporting and recordkeeping requirements, Water pollution control, 
Water supply.

40 CFR Part 302

    Environmental protection, Air pollution control, Chemicals, 
Hazardous substances, Hazardous waste, Intergovernmental relations, 
Natural resources, Reporting and recordkeeping requirements, Superfund, 
Water pollution control, Water supply.

    Dated: June 29, 1998.
Carol M. Browner,
Administrator.
    For the reasons set out in the preamble, title 40, chapter I, of 
the Code of Federal Regulations is amended as follows:

PART 148--HAZARDOUS WASTE INJECTION RESTRICTIONS

    1. The authority citation for part 148 continues to read as 
follows:

    Authority: Secs. 3004, Resource Conservation and Recovery Act, 
42 U.S.C. 6901 et seq.

    2. Section 148.18 is amended by adding paragraph (i) to read as 
follows:


Sec. 148.18  Waste specific prohibitions--newly listed and identified 
Wastes.

* * * * *
    (i) Effective February 8, 1999, the wastes specified in 40 CFR 
261.32 as EPA Hazardous Waste Numbers K169, K170, K171, and K172 are 
prohibited from underground injection.

PART 261--IDENTIFICATION AND LISTING OF HAZARDOUS WASTE

    3. The authority citation for part 261 continues to read as 
follows:

    Authority: 42 U.S.C. 6905, 6912(a), 6921, 6922, 6924(y), and 
6938.

    4. Section 261.3 is amended by revising paragraphs (a)(2)(iv)(C) 
and (c)(2)(ii)(B); and by adding paragraph (c)(2)(ii)(E) to read as 
follows.


Sec. 261.3  Definition of hazardous waste.

    (a) * * *
    (2) * * *
    (iv) * * *
    (C) One of the following wastes listed in Sec. 261.32, provided 
that the wastes are discharged to the refinery oil recovery sewer 
before primary oil/water/solids separation--heat exchanger bundle 
cleaning sludge from the petroleum refining industry (EPA Hazardous 
Waste No. K050), crude oil storage tank sediment from petroleum 
refining operations (EPA Hazardous Waste No. K169), clarified slurry 
oil tank sediment and/or in-line filter/separation solids from 
petroleum refining operations (EPA Hazardous Waste No. K170), spent 
hydrotreating catalyst (EPA Hazardous Waste No. K171), and spent 
hydrorefining catalyst (EPA Hazardous Waste No. K172); or
* * * * *
    (c) * * *
    (2) * * *
    (ii) * * *
    (B) Waste from burning any of the materials exempted from 
regulation by Sec. 261.6(a)(3)(iii) and (iv).
* * * * *
    (E) Catalyst inert support media separated from one of the 
following wastes listed in Sec. 261.32--Spent hydrotreating catalyst 
(EPA Hazardous Waste No. K171), and Spent hydrorefining catalyst (EPA 
Hazardous Waste No. K172).
* * * * *
    5. In Sec. 261.4, new paragraphs (a)(18) and (a)(19) are added, and 
paragraph (a)(12) is revised to read as follows:
* * * * *


Sec. 261.4  Exclusions.

    (a) * * *
    (12) (i) Oil-bearing hazardous secondary materials (i.e., sludges, 
byproducts, or spent materials) that are generated at a petroleum 
refinery (SIC code 2911) and are inserted into the petroleum refining 
process (SIC code 2911--including, but not limited to, distillation, 
catalytic cracking, fractionation, or thermal cracking units (i.e., 
cokers)) unless the material is placed on the land, or speculatively 
accumulated before being so recycled. Materials inserted into thermal 
cracking units are excluded under this paragraph, provided that the 
coke product also does not exhibit a characteristic of hazardous waste. 
Oil-bearing hazardous secondary materials may be inserted into the same 
petroleum refinery where they are generated, or sent directly to 
another petroleum refinery, and still be excluded under this provision. 
Except as provided in paragraph (a)(12)(ii) of this section, oil-
bearing hazardous secondary materials generated elsewhere in the 
petroleum industry (i.e., from sources other than petroleum refineries) 
are not excluded under this section. Residuals generated from 
processing or recycling materials excluded under this paragraph 
(a)(12)(i), where such materials as generated would have otherwise met 
a listing under subpart D of this part, are designated as F037 listed 
wastes when disposed of or intended for disposal.
    (ii) Recovered oil that is recycled in the same manner and with the 
same conditions as described in paragraph (a)(12)(i) of this section. 
Recovered oil is oil that has been reclaimed from secondary materials 
(including wastewater) generated from normal petroleum industry 
practices, including refining, exploration and production, bulk 
storage, and transportation incident thereto (SIC codes 1311, 1321, 
1381, 1382, 1389, 2911, 4612, 4613, 4922, 4923, 4789, 5171, and 5172.) 
Recovered oil does not include oil-bearing hazardous wastes listed in 
subpart D of this part; however, oil recovered from such wastes may be 
considered recovered oil. Recovered oil does not include used oil as 
defined in 40 CFR 279.1.
* * * * *

[[Page 42185]]

    (18) Petrochemical recovered oil from an associated organic 
chemical manufacturing facility, where the oil is to be inserted into 
the petroleum refining process (SIC code 2911) along with normal 
petroleum refinery process streams, provided:
    (i) The oil is hazardous only because it exhibits the 
characteristic of ignitability (as defined in Sec. 261.21) and/or 
toxicity for benzene (Sec. 261.24, waste code D018); and
    (ii) The oil generated by the organic chemical manufacturing 
facility is not placed on the land, or speculatively accumulated before 
being recycled into the petroleum refining process. An ``associated 
organic chemical manufacturing facility'' is a facility where the 
primary SIC code is 2869, but where operations may also include SIC 
codes 2821, 2822, and 2865; and is physically co-located with a 
petroleum refinery; and where the petroleum refinery to which the oil 
being recycled is returned also provides hydrocarbon feedstocks to the 
organic chemical manufacturing facility. ``Petrochemical recovered 
oil'' is oil that has been reclaimed from secondary materials (i.e., 
sludges, byproducts, or spent materials, including wastewater) from 
normal organic chemical manufacturing operations, as well as oil 
recovered from organic chemical manufacturing processes.
    (19) Spent caustic solutions from petroleum refining liquid 
treating processes used as a feedstock to produce cresylic or 
naphthenic acid unless the material is placed on the land, or 
accumulated speculatively as defined in Sec. 261.1(c).
* * * * *


Sec. 261.6  [Amended]

    6. In Sec. 261.6, paragraph (a)(3)(iv)(C) is amended by removing 
``; and'' at the end of the paragraph and adding a period in its place; 
and paragraph (a)(3)(v) is removed.
    7. In Sec. 261.31(a), the table is amended by revising the entry 
for F037, to read as follows:


Sec. 261.31  Hazardous wastes from non-specific sources.

    (a) * * *

------------------------------------------------------------------------
  Industry and EPA                                                      
 hazardous waste No.           Hazardous waste             Hazard code  
------------------------------------------------------------------------
                                                                        
*                  *                  *                  *              
F037................  Petroleum refinery primary oil/    (T)            
                       water/solids separation sludge-                  
                       Any sludge generated from the                    
                       gravitational separation of oil/                 
                       water/solids during the storage                  
                       or treatment of process                          
                       wastewaters and oily cooling                     
                       wastewaters from petroleum                       
                       refineries. Such sludges                         
                       include, but are not limited to,                 
                       those generated in oil/water/                    
                       solids separators; tanks and                     
                       impoundments; ditches and other                  
                       conveyances; sumps; and                          
                       stormwater units receiving dry                   
                       weather flow, sludge generated                   
                       in stormwater units that do not                  
                       receive dry weather flow,                        
                       sludges generated from non-                      
                       contact once-through cooling                     
                       waters segregated for treatment                  
                       from other process or oily                       
                       cooling waters, sludges                          
                       generated in aggressive                          
                       biological treatment units as                    
                       defined in Sec.  261.31(b)(2)                    
                       (including sludges generated in                  
                       one or more additional units                     
                       after wastewaters have been                      
                       treated in aggressive biological                 
                       treatment units) and K051 wastes                 
                       are not included in this                         
                       listing. This listing does                       
                       include residuals generated from                 
                       processing or recycling oil-                     
                       bearing hazardous secondary                      
                       materials excluded under Sec.                    
                       261.4(a)(12)(i), if those                        
                       residuals are to be disposed of.                 
                                                                        
*                  *                  *                  *              
                  *                  *                  *               
------------------------------------------------------------------------

* * * * * * *
    8. In Sec. 261.32, the table is amended by adding in alphanumeric 
order (by the first column) the following waste streams to the subgroup 
``Petroleum refining'' to read as follows:


Sec. 261.32  Hazardous wastes from specific sources.

* * * * * * *

------------------------------------------------------------------------
  Industry and EPA                                                      
 hazardous waste No.           Hazardous waste             Hazard code  
------------------------------------------------------------------------
                                                                        
*                  *                  *                  *              
Petroleum refining:                                                     
*                  *                  *                  *              
                  *                  *                  *               
  K169..............  Crude oil storage tank sediment    (T)            
                       from petroleum refining                          
                       operations.                                      
  K170..............  Clarified slurry oil tank          (T)            
                       sediment and/or in-line filter/                  
                       separation solids from petroleum                 
                       refining operations.                             
  K171..............  Spent Hydrotreating catalyst from  (I,T)          
                       petroleum refining operations,                   
                       including guard beds used to                     
                       desulfurize feeds to other                       
                       catalytic reactors (this listing                 
                       does not include inert support                   
                       media).                                          
  K172..............  Spent Hydrorefining catalyst from  (I,T)          
                       petroleum refining operations,                   
                       including guard beds used to                     
                       desulfurize feeds to other                       
                       catalytic reactors (this listing                 
                       does not include inert support                   
                       media).                                          
                                                                        
*                  *                  *                  *              
                  *                  *                  *               
------------------------------------------------------------------------

    9. Appendix VII to Part 261 is amended by adding the following 
waste streams in alphanumeric order (by the first column) to read as 
follows.

[[Page 42186]]

APPENDIX VII TO PART 261--BASIS FOR LISTING HAZARDOUS WASTE

------------------------------------------------------------------------
   EPA hazardous waste No.      Hazardous constituents for which listed 
------------------------------------------------------------------------
                                                                        
*                  *                  *                  *              
K169........................  Benzene.                                  
K170........................  Benzo(a)pyrene, dibenz(a,h)anthracene,    
                               benzo (a) anthracene, benzo              
                               (b)fluoranthene, benzo(k)fluoranthene, 3-
                               methylcholanthrene, 7, 12-               
                               dimethylbenz(a)anthracene.               
K171........................  Benzene, arsenic.                         
K172........................  Benzene, arsenic.                         
------------------------------------------------------------------------

PART 266--STANDARDS FOR THE MANAGEMENT OF SPECIFIC HAZARDOUS WASTES 
AND SPECIFIC TYPES OF HAZARDOUS WASTE MANAGEMENT FACILITIES

The authority citation for part 266 is revised to read as follows:

    Authority: 42 U.S.C. 1006, 2002(a), 3004, and 3014, 6905, 6906, 
6912, 6922, 6924, 6925, and 6937.

    11. Section 266.100(b)(3) is revised to read as follows:


Sec. 266.100  Applicability.

* * * * *
    (b)* * *
    (3) Hazardous wastes that are exempt from regulation under 
Secs. 261.4 and 261.6(a)(3) (iii) and (iv) of this chapter, and 
hazardous wastes that are subject to the special requirements for 
conditionally exempt small quantity generators under Sec. 261.5 of this 
chapter; and
* * * * *


PART 268--LAND DISPOSAL RESTRICTIONS

    12. The authority citation for part 268 continues to read as 
follows:

    Authority: 42 U.S.C. 6905, 6912(a), 6921, and 6924.

Subpart C--Prohibitions on Land Disposal

    13. Section 268.35 is added to subpart C to read as follows:


Sec. 268.35  Waste specific prohibitions-petroleum refining wastes.

    (a) Effective February 8, 1999, the wastes specified in 40 CFR part 
261 as EPA Hazardous Wastes Numbers K169, K170, K171, and K172, soils 
and debris contaminated with these wastes, radioactive wastes mixed 
with these hazardous wastes, and soils and debris contaminated with 
these radioactive mixed wastes, are prohibited from land disposal.
    (b) The requirements of paragraph (a) of this section do not apply 
if:
    (1) The wastes meet the applicable treatment standards specified in 
Subpart D of this part;
    (2) Persons have been granted an exemption from a prohibition 
pursuant to a petition under Sec. 268.6, with respect to those wastes 
and units covered by the petition;
    (3) The wastes meet the applicable treatment standards established 
pursuant to a petition granted under Sec. 268.44;
    (4) Hazardous debris that have met treatment standards in 
Sec. 268.40 or in the alternative treatment standards in Sec. 268.45; 
or
    (5) Persons have been granted an extension to the effective date of 
a prohibition pursuant to Sec. 268.5, with respect to these wastes 
covered by the extension.
    (c) To determine whether a hazardous waste identified in this 
section exceeds the applicable treatment standards specified in 
Sec. 268.40, the initial generator must test a sample of the waste 
extract or the entire waste, depending on whether the treatment 
standards are expressed as concentrations in the waste extract or the 
waste, or the generator may use knowledge of the waste. If the waste 
contains constituents in excess of the applicable Universal Treatment 
Standard levels of Sec. 268.48, the waste is prohibited from land 
disposal, and all requirements of this part are applicable, except as 
otherwise specified.

Subpart D--Treatment Standards

    14. In Sec. 268.40, the Table of Treatment Standards is amended by 
adding in alphanumeric order new entries for K169, K170, K171, and K172 
to read as follows. The appropriate footnotes to the Table of Treatment 
Standards are republished without change.


Sec. 268.40  Applicability of treatment standards.

* * * * *

[[Page 42187]]



                                                        Treatment Standards for Hazardous Wastes                                                        
                                                             [Note: NA means not applicable]                                                            
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                    Regulated hazardous constituent                Wastewaters                    Nonwastewaters        
                        Waste description and  ---------------------------------------------------------------------------------------------------------
      Waste code         treatment/regulatory                                                                               Concentration in mg/kg \5\  
                           subcategory \1\            Common Name          CAS \2\ No.     Concentration in mg/L\3\; or   unless noted as ``mg/L TCLP'';
                                                                                               technology code \4\            or technology code \4\    
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                                        
                   *                  *                  *                  *                  *                  *                  *                  
K169.................  Crude oil tank sediment  Benz(a)anthracene......         56-55-3  0.059..........................  3.4                           
                        from petroleum                                                                                                                  
                        refining operations.                                                                                                            
                                                Benzene................         71-43-2  0.14...........................  10                            
                                                Benzo(g,h,i)perylene...        191-24-2  0.0055.........................  1.8                           
                                                Chrysene...............        218-01-9  0.059..........................  3.4                           
                                                Ethyl benzene..........        100-41-4  0.057..........................  10                            
                                                Fluorene...............         86-73-7  0.059..........................  3.4                           
                                                Naphthalene............         91-20-3  0.059..........................  5.6                           
                                                Phenanthrene...........         81-05-8  0.059..........................  5.6                           
                                                Pyrene.................        129-00-0  0.067..........................  8.2                           
                                                Toluene (Methyl                108-88-3  0.080..........................  10                            
                                                 Benzene).                                                                                              
                                                Xylene(s) (Total)......       1330-20-7  0.32...........................  30                            
K170.................  Clarified slurry oil     Benz(a)anthracene......         56-55-3  0.059..........................  3.4                           
                        sediment from                                                                                                                   
                        petroleum refining                                                                                                              
                        operations.                                                                                                                     
                                                Benzene................         71-43-2  0.14...........................  10                            
                                                Benzo(g,h,i)perylene...        191-24-2  0.0055.........................  1.8                           
                                                Chrysene...............        218-01-9  0.059..........................  3.4                           
                                                Dibenz(a,h)anthracene..         53-70-3  0.055 8.2......................                                
                                                Ethyl benzene..........        100-41-4  0.057..........................  10                            
                                                Fluorene...............         86-73-7  0.059..........................  3.4                           
                                                Indeno(1,2,3,-cd)pyrene        193-39-5  0.0055.........................  3.4                           
                                                Naphthalene............         91-20-3  0.059..........................  5.6                           
                                                Phenanthrene...........         81-05-8  0.059..........................  5.6                           
                                                Pyrene.................        129-00-0  0.067..........................  8.2                           
                                                Toluene (Methyl                108-88-3  0.080..........................  10                            
                                                 Benzene).                                                                                              
                                                Xylene(s) (Total)......       1330-20-7  0.32...........................  30                            
K171.................  Spent hydrotreating      Benz(a)anthracene......         56-55-3  0.059..........................  3.4                           
                        catalyst from                                                                                                                   
                        petroleum refining                                                                                                              
                        operations, including                                                                                                           
                        guard beds used to                                                                                                              
                        desulfurize feeds to                                                                                                            
                        other catalytic                                                                                                                 
                        reactors (this listing                                                                                                          
                        does not include inert                                                                                                          
                        support media.).                                                                                                                
                                                Benzene................         71-43-2  0.14...........................  10                            
                                                Chrysene...............        218-01-9  0.059..........................  3.4                           
                                                Ethyl benzene..........        100-41-4  0.057..........................  10                            
                                                Naphthalene............         91-20-3  0.059..........................  5.6                           
                                                Phenanthrene...........         81-05-8  0.059..........................  5.6                           
                                                Pyrene 129-00-0........           0.067  8.2............................                                
                                                Toluene (Methyl                108-88-3  0.080..........................  10                            
                                                 Benzene).                                                                                              
                                                Xylene(s) (Total)......       1330-20-7  0.32...........................  30                            
                                                Arsenic................       7740-38-2  1.4............................  5 mg/L TCLP                   
                                                Nickel.................       7440-02-0  3.98...........................  11.0 mg/L TCLP                
                                                Vanadium...............       7440-62-2  4.3............................  1.6 mg/L TCLP                 
                                                Reactive sulfides......              NA  DEACT..........................  DEACT                         
K172.................  Spent hydrorefining      Benzene................         71-43-2  0.14...........................  10                            
                        catalyst from                                                                                                                   
                        petroleum refining                                                                                                              
                        operations, including                                                                                                           
                        guard beds used to                                                                                                              
                        desulfurize feeds to                                                                                                            
                        other catalytic                                                                                                                 
                        reactors (this listing                                                                                                          
                        does not include inert                                                                                                          
                        support media.).                                                                                                                
                                                Ethyl benzene..........        100-41-4  0.057..........................  10                            
                                                Toluene (Methyl                108-88-3  0.080..........................  10                            
                                                 Benzene).                                                                                              
                                                Xylene(s) (Total)......       1330-20-7  0.32...........................  30                            
                                                Antimony...............       7740-36-0  1.9............................  1.15 mg/L TCLP                
                                                Arsenic................       7740-38-2  1.4............................  5 mg/L TCLP                   
                                                Nickel.................       7440-02-0  3.98...........................  11.0 mg/L TCLP                
                                                Vanadium...............       7440-62-2  4.3............................  1.6 mg/L TCLP                 
                                                Reactive Sulfides......              NA  DEACT..........................  DEACT                         
                                                                                                                                                        

[[Page 42188]]

                                                                                                                                                        
                   *                  *                  *                  *                  *                  *                  *                  
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ The waste descriptions provided in this table do not replace waste descriptions in 40 CFR part 261. Descriptions of Treatment/Regulatory            
  Subcategories are provided, as needed, to distinguish between applicability of different standards.                                                   
\2\ CAS means Chemical Abstract Services. When the waste code and/or regulated constituents are described as a combination of a chemical with its salts 
  and/or esters, the CAS number is given for the parent compound only.                                                                                  
\3\ Concentration standards for wastewaters are expressed in mg/L and are based on analysis of composite samples.                                       
\4\ All treatment standards expressed as a Technology Code or combination of Technology Codes are explained in detail in 40 CFR 268.42 Table 1--        
  Technology Codes and Descriptions of Technology-Based Standards.                                                                                      
\5\ Except for Metals (EP or TCLP) and Cyanides (Total and Amenable) the nonwastewater treatment standards expressed as a concentration were            
  established, in part, based upon incineration in units operated in accordance with the technical requirements of 40 CFR part 264, Subpart O or part   
  265 Subpart O, or based upon combustion in fuel substitution units operating in accordance with applicable technical requirements. A facility may     
  comply with these treatment standards according to provisions in 40 CFR 268.40(d). All concentration standards for nonwastewaters are based on        
  analysis of grab samples.                                                                                                                             

* * * * * * *

PART 271--REQUIREMENTS FOR AUTHORIZATION OF STATE HAZARDOUS WASTE 
PROGRAMS

    15. The authority citation for part 271 continues to read as 
follows:

    Authority: 42 U.S.C. 6905, 6912(a), and 6926.

Subpart A--Requirements for Final Authorization

    16. Section 271.1(j) is amended by adding the following entries to 
Table 1 in chronological order by date of publication in the Federal 
Register, and by adding the following entries to Table 2 in 
chronological order by effective date in the Federal Register, to read 
as follows:


Sec. 271.1  Purpose and scope.

* * * * *
    (j) * * *

               Table 1.--Regulations Implementing the Hazardous and Solid Waste Amendments of 1984              
----------------------------------------------------------------------------------------------------------------
                                                               Federal Register                                 
         Promulgation date            Title of regulation         reference                Effective date       
----------------------------------------------------------------------------------------------------------------
                                                                                                                
*                  *                  *                  *                  *                  *                
August 6, 1998.....................  Petroleum Refining     [Insert FR page        February 8, 1999.            
                                      Process Wastes.        numbers].                                          
----------------------------------------------------------------------------------------------------------------

*                  *                  *                  *          
        *                  *                  *

                  Table 2.--Self-Implementing Provisions of the Solid Waste Amendments of 1984                  
----------------------------------------------------------------------------------------------------------------
                                       Self-implementing                                                        
           Effective date                  provision            RCRA citation        Federal Register reference 
----------------------------------------------------------------------------------------------------------------
                                                                                                                
*                  *                  *                  *                  *                  *                
February 8, 1999...................  Prohibition on land    3004(g)(4) (C) and     August 6, 1998. 63 FR [Insert
                                      disposal of newly      3004 (m).              page numbers]               
                                      listed and                                                                
                                      identified wastes;                                                        
                                      and prohibition on                                                        
                                      land disposal of                                                          
                                      radioactive waste                                                         
                                      mixed with the newly                                                      
                                      listed or identified                                                      
                                      wastes, including                                                         
                                      soil and debris.                                                          
                                                                                                                
*                  *                  *                  *                  *                  *                
                                                        *                                                       
----------------------------------------------------------------------------------------------------------------

*                  *                  *                  *          
        *                  *                  *


PART 302--DESIGNATION, REPORTABLE QUANTITIES, AND NOTIFICATION

    17. The authority citation for part 302 continues to read as 
follows:

    Authority: 42 U.S.C. 9602, 9603, and 9604; 33 U.S.C. 1321 and 
1361.

    18. In Sec. 302.4, table 302.4 is amended by adding footnote f and 
the following new entries in alphanumerical order at the end of the 
table to read as follows:


Sec. 302.4  Designation of hazardous substances.

*                  *                  *                  *          
        *                  *                  *

[[Page 42189]]



                                           Table 302.4--List of Hazardous Substances and Reportable Quantities                                          
                                             [Note: All Comments/Notes Are Located at the End of This Table]                                            
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                             Statutory                                               Final RQ           
       Hazardous substance               CASRN         Regulatory synonyms ------------- Code    RCRA waste No.  -------------------------------
                                                                                 RQ                                            Category      Pounds (Kg)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                   *                  *                  *                  *                  *                  *                  *                  
K169f...........................  ...................  ...................         \1\*             4  K169               A                     10(4.54)
Crude oil storage tank sediment                                                                                                                         
 from petroleum refining                                                                                                                                
 operations.                                                                                                                                            
K170f...........................  ...................  ...................         \1\*             4  K170               X                    1 (0.454)
Clarified slurry oil tank                                                                                                                               
 sediment and/or in-line filter/                                                                                                                        
 separation solids from                                                                                                                                 
 petroleum refining operations.                                                                                                                         
K171f...........................  ...................  ...................         \1\*             4  K171               X                    1 (0.454)
Spent hydrotreating catalyst                                                                                                                            
 from petroleum refining                                                                                                                                
 operations. (This listing does                                                                                                                         
 not include inert support                                                                                                                              
 media.)                                                                                                                                                
K172f...........................  ...................  ...................         \1\*             4  K172               X                    1 (0.454)
Spent hydrorefining catalyst                                                                                                                            
 from petroleum refining                                                                                                                                
 operations. (This listing does                                                                                                                         
 not include inert support                                                                                                                              
 media.)                                                                                                                                                
--------------------------------------------------------------------------------------------------------------------------------------------------------
 Indicates the statutory sources as defined by 1, 2, 3, and 4 below.                                                                            
                                                                                                                                                        
            *                *                *                *                *                *                *                                     
\1\*--Indicates that the 1-pound RQ is a CERCLA statutory RQ.                                                                                           
                                                                                                                                                        
            *                *                *                *                *                *                *                                     
f See 40 CFR 302.6(b)(1) for application of the mixture rule to this hazardous waste.                                                                   

    19. Section 302.6 is amended by revising paragraphs (b)(1)(i) and 
(b)(1)(ii) and by adding paragraph (b)(1)(iii) to read as follows:


Sec. 302.6  Notification requirements.

* * * * *
    (b) * * *
    (1) * * *
    (i) If the quantity of all of the hazardous constituent(s) of the 
mixture or solution is known, notification is required where an RQ or 
more of any hazardous constituent is released;
    (ii) If the quantity of one or more of the hazardous constituent(s) 
of the mixture or solution is unknown, notification is required where 
the total amount of the mixture or solution released equals or exceeds 
the RQ for the hazardous constituent with the lowest RQ; or
    (iii) For waste streams K169, K170, K171, and K172, knowledge of 
the quantity of all of the hazardous constituent(s) may be assumed, 
based on the following maximum observed constituent concentrations 
identified by EPA:

------------------------------------------------------------------------
        Waste                      Constituent                 Max ppm  
------------------------------------------------------------------------
K169................  Benzene..............................        220.0
K170................  Benzene..............................          1.2
                      Benzo (a) pyrene.....................        230.0
                      Dibenz (a,h) anthracene..............         49.0
                      Benzo (a) anthracene.................        390.0
                      Benzo (b) fluoranthene...............        110.0
                      Benzo (k) fluoranthene...............        110.0
                      3-Methylcholanthrene.................         27.0
                      7,12-Dimethylbenz (a) anthracene.....      1,200.0
K171................  Benzene..............................        500.0
                      Arsenic..............................      1,600.0
K172................  Benzene..............................        100.0
                      Arsenic..............................        730.0
------------------------------------------------------------------------

* * * * *
[FR Doc. 98-19929 Filed 8-5-98; 8:45 am]
BILLING CODE 6560-50-P