[Federal Register Volume 62, Number 67 (Tuesday, April 8, 1997)]
[Proposed Rules]
[Pages 16747-16753]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-8816]


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

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 261

[FRL-5807-5]
RIN 2050-AD88


Hazardous Waste Management System; Identification and Listing of 
Hazardous Waste; Petroleum Refining Process Wastes; and Land Disposal 
Restrictions for Newly Hazardous Wastes; Notice of Data Availability

AGENCY: Environmental Protection Agency.

ACTION: Notice of data availability and request for comment.

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

SUMMARY: The Environmental Protection Agency (EPA) is making available 
for public comment data and information relating to its Notice 
published in the Federal Register on November 20, 1995 (60 FR 57747). 
That Notice proposed to amend EPA regulations under the Resource 
Conservation and Recovery Act (RCRA) by designating as hazardous wastes 
certain petroleum refining waste streams and proposed not to list other 
petroleum waste streams. The Notice also proposed to broaden existing 
RCRA exemptions for recycling of oil-bearing residuals and proposed to 
apply universal treatment standards under the Land Disposal 
Restrictions program to the wastes proposed for listing.
    Comments submitted by interested members of the public on the 
proposal have convinced EPA that the rulemaking record could be 
considerably improved by adding data and subjecting analysis of that 
data to public comments. Today's document, therefore, presents for 
public comment modeling analyses using different assumptions than used 
for the proposal, additional analyses of waste characteristics and 
disposal practices, and other evaluations of the potential impact of 
different modeling assumptions on the risk assessment results. This 
document also corrects a number of technical errors that were contained 
in the original proposal.
    Pursuant to a consent decree in Environmental Defense Fund (EDF) v. 
Browner (Civ. No. 89-0598 D.D.C.), EPA has committed to issuing this 
Notice of data availability before making the final regulatory 
determination on whether the subject petroleum refining residuals 
should be listed as hazardous wastes. The consent decree requires the 
final rule to be issued by April 30, 1998. The Agency solicits comments 
on all aspects of the new information sources described in this Notice. 
All comments on the new information received by the close of the 
comment period will be considered by the Agency when making a final 
regulatory determination. Comments will be accepted and considered only 
on the new data mentioned in today's Notice and specifically identified 
under the docket number given in this document.

DATES: The Agency is reopening the comment period only for the limited 
purpose of obtaining information and views on the new data and analyses 
described in this Notice. Comments on the additional data will be 
accepted through June 9, 1997. Due to the short deadline for the final 
rule, EPA does not plan to grant any extensions of the comment period.

ADDRESSES: Commenters must send an original and two copies of their 
comments referencing docket number F-97-PRA-FFFFF to: RCRA Docket 
Information Center, Office of Solid Waste (5305G), U.S. Environmental 
Protection Agency Headquarters (EPA, HQ), 401 M Street, SW, Washington, 
D.C. 20460. Hand deliveries of comments should be made to the 
Arlington, VA, address listed below. Comments may also be submitted 
electronically by sending electronic mail through the Internet to: 
[email protected]. Comments in electronic format should also 
be identified by the docket number F-97-PRA-FFFFF. All electronic 
comments must be submitted as an ASCII file avoiding the use of special 
characters and any form of encryption. If comments are not submitted 
electronically, EPA is asking prospective commenters to voluntarily 
submit one additional copy of their comments on labeled personal 
computer diskettes in ASCII (TEXT) format or a word processing format 
that can be converted to ASCII (TEXT). It is essential to specify on 
the disk label the word processing software and version/edition as well 
as the commenter's name. This will allow EPA to convert the comments 
into one of the word processing formats utilized by the Agency. Please 
use mailing envelopes designed to physically protect the submitted 
diskettes. EPA emphasizes that submission of comments on diskettes is 
not mandatory, nor will it result in any advantage or disadvantage to 
any commenter.
    Commenters should not submit electronically any confidential 
business information (CBI). An original and two copies of CBI must be 
submitted under separate cover to: RCRA CBI Document Control Officer, 
Office of Solid Waste (5305W), U.S. EPA, 401 M Street, SW, Washington, 
D.C. 20460.
    Public comments and 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 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. For information on accessing paper 
and/or electronic copies of the document, see the Supplementary 
Information section.

FOR FURTHER INFORMATION CONTACT: For general information, contact the 
RCRA Hotline at (800) 424-9346 or TDD (800) 553-7672 (hearing 
impaired). In the Washington, D.C., metropolitan area, call (703) 412-
9810 or TDD (703) 412-3323. For information on specific aspects of the 
report, contact Maximo Diaz, Jr. or Robert Kayser, Office of Solid 
Waste (5304W), U.S. Environmental Protection Agency, 401 M Street, SW, 
Washington, D.C. 20460.

[[Page 16748]]

[E-mail addresses and telephone numbers: D[email protected], 
(703) 308-0439; K[email protected], (703) 308-7304)].

SUPPLEMENTARY INFORMATION: Supporting documents in the docket for this 
Notice are also available in electronic format on the Internet. Follow 
these instructions to access these documents.

WWW: http://www.epa.gov/epaoswer/hazwaste/id
FTP: ftp.epa/gov
Login: anonymous
Password: your Internet address
Files are located in /pub/gopher/OSWRCRA.

    The official record for this action will be kept in paper form. 
Accordingly, EPA will transfer all comments received electronically 
into paper form and place them in the official record, which will also 
include all comments submitted directly in writing. The official record 
is the paper record maintained at the address in ADDRESSES at the 
beginning of this document.
    EPA responses to comments, whether the comments are written or 
electronic, will be in a notice in the Federal Register or in a 
response to comments document placed in the official record for this 
rulemaking. EPA will not immediately reply to commenters electronically 
other than to seek clarification of electronic comments that may be 
garbled in transmission or during conversion to paper form, as 
discussed above.

Background

    RCRA section 3001(e), 42 U.S.C. 6921(e) requires EPA to make a 
determination whether to list certain specified wastes under RCRA 
section 3001(b)(1), 42 U.S.C. 6921(b)(1). These include petroleum 
refining wastes. The effect of such a listing would be to subject the 
wastes to regulation as hazardous waste under Subtitle C of RCRA. 
Pursuant to a consent decree between EPA and the Environmental Defense 
Fund (EDF), EPA has agreed to a schedule for promulgating a listing 
determination for fourteen petroleum residuals that the Agency had not 
previously considered listing.
    EPA issued its proposed determination regarding the petroleum 
residuals on November 20, 1995 (60 FR 57747). EDF and EPA have 
negotiated a modification to the Consent Decree, in which the Agency 
has agreed to promulgate the final listing determination on or before 
April 30, 1998. EPA also agreed to issue today's Notice of data 
availability.
    In the proposal, EPA considered whether the petroleum refining 
residuals met the criteria for listing a waste as hazardous as set out 
in 40 C.F.R. 261.11. EPA evaluated the potential toxicity of the 
constituents present in the wastes, the fate and mobility of the 
constituents, likely exposure routes, and the current waste management 
practices. EPA conducted a quantitative risk assessment where such an 
assessment was appropriate. The Agency proposed to list three of the 
wastes based on a determination that the wastes may pose a substantial 
present or potential hazard to human health or the environment when 
improperly managed. These wastes are: Clarified Slurry Oil Tank 
Sediment and/or In-line Filter/Separation Solids, Spent Catalyst from 
Hydrotreating, and Spent Catalyst from Hydrorefining. EPA proposed not 
to list the remaining 11 wastes.
    EPA received approximately 2000 pages of comments from 52 parties, 
many raising a variety of complex technical issues. After reviewing the 
comments, EPA decided it was appropriate to undertake a variety of 
analyses not previously available to the public to assess the impact of 
using alternative assumptions in the Agency's risk assessment. Although 
these additional analyses are a logical outgrowth of the comments 
received and additional Notice and public comment is, therefore, not 
required, EPA has nevertheless decided that this Notice of data 
availability is a useful exercise and will help to strengthen the 
record for the Agency's decisions.
    The remainder of this Notice is divided into two general parts. The 
first deals with new data and analyses prompted by public comments 
claiming EPA's analysis was either incorrect or incomplete; the second 
deals with portions of the record that public comments indicated were 
not clear and require better explanation.

Additional Information

    As a result of reviewing the public comments, EPA reexamined the 
modeling approaches used for both groundwater and nongroundwater 
exposure risks in making the listing determinations in the November 
1995 Notice, completed a variety of additional modeling analyses, 
examined a number of alternative modeling assumptions, and gathered and 
evaluated additional relevant data. EPA also obtained additional data 
and performed additional analyses in response to comments for some of 
the other decisions described in the November 1995 Notice. A complete 
list of all new materials placed in the docket is available from the 
RCRA Docket at the address and telephone number listed above. A summary 
of the new data and analyses follows.
      Supplemental Background Document; Groundwater Pathway 
Risk Analysis; Petroleum Refining Process Waste Listing Determination--
EPA has prepared a new document, with this title, that presents 
alternative approaches to the groundwater modeling used to evaluate 
risks from landfills. The alternative approaches are: A revised ``high-
end'' analysis; a probabilistic Monte Carlo analysis; an analysis of 
potential risks presented by codisposal of petroleum wastes in the same 
landfill; an analysis of potential risks arising from a contingent 
management listing; consideration of noningestion risks related to 
groundwater use; and the potential for the RCRA Toxicity Characteristic 
(TC), promulgated under 40 CFR 262.24, to reduce risks for some wastes.
      Supplemental Background Document; Nongroundwater Pathway 
Risk Assessment; Petroleum Refining Process Waste Listing 
Determination--EPA prepared a new document, with this title, that 
presents modeling analyses for pathways other than groundwater for land 
treatment disposal. These analyses incorporate several modifications to 
the assumptions used for the proposal including: Limiting unit 
characteristics of the onsite units used in risk modeling to units that 
are not permitted hazardous waste units; removing from modeling 
consideration the volumes of hazardous wastes that could not be sent to 
a nonhazardous land treatment unit; changes to the models used to 
estimate release and transport of contaminated soil to offsite 
receptors; and incorporating the soil biodegradation of constituents 
after they travel offsite. The document also presents results from an 
analysis of potential risks due to codisposal of multiple petroleum 
wastes in the same land treatment unit. In addition, this document 
contains a detailed description of the model selected to estimate risks 
from noningestion exposures (inhalation and dermal absorption) arising 
from residential use of groundwater (see also the Background Document 
for groundwater pathway risk analysis for results of this modeling).
      Supplemental Background Document; Listing Support 
Analyses; Petroleum Refining Process Waste Listing Determination--EPA 
prepared a document, with this title, that presents a variety of 
additional data and analyses in the following areas:


[[Page 16749]]


--Analyses Regarding Leaching of Oily Waste--Comments questioned 
whether the method used by EPA (Toxicity Characteristic Leaching 
Procedure or TCLP) substantially underestimates the mobility of 
constituents in oily wastes sent to landfills because of problems with 
the method (e.g., filters clog), and because constituents may be 
released in an oily phase, as well as dissolved in aqueous leachate. 
EPA presents several analyses related to the potential for oil in the 
petroleum residuals to affect chemical analysis and risk assessment. 
The data presented consist of: compiled field and laboratory data on 
the appearance and oily nature of the residuals; the oil and grease 
content reported by petroleum refineries in wastes that were sent to 
landfills for disposal; additional analysis of archived samples for 
metal constituents using an alternative leaching method mentioned by a 
commenter, the Oily Waste Extraction Procedure (OWEP); and the 
calculation of leaching efficiency for organic constituents in the 
wastes EPA sampled.
--Potential for Additive Risks From Multiple Sources--Comments 
suggested that the groundwater and nongroundwater risks should be added 
together to reflect the total potential risks for the wastes evaluated. 
In this notice, EPA is summarizing data in the record to assess the 
proximity of onsite nonhazardous landfills and land treatment units at 
each facility surveyed to examine the potential for combined exposures 
to releases from both types of units.
--The Potential Impact of Oil-Bearing Residuals Exclusion on Coke 
Product--EPA proposed to exclude from the definition of solid waste 
oil-bearing residuals from certain petroleum industry sources that are 
inserted back into the refining process (including the petroleum coker 
unit), provided certain conditions are met. EPA cited industry data 
showing that such oil-bearing residuals (e.g., listed sludges) are 
similar to normal feedstock material. Some public comments disagreed 
with excluding these residuals from the definition of solid waste and 
argued that this action would allow the unregulated disposal of 
``toxics along for the ride'' due to the transfer of constituents in 
the wastes to products, such as coke. In evaluating comments on the 
proposed rule, EPA realized it had omitted from the original docket an 
analysis concerning the potential impacts that recycling petroleum 
wastewater treatment sludge into coke production might have on metals 
loading in the coke product. The purpose of this document is to provide 
the analysis conducted in support of the proposed rule, revised to 
reflect more current data.
--Comparison of Product Coke to Off-Spec Product and Fines From Thermal 
Processes--Comments 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 this Notice, EPA has clarified the existing 
record, as noted below, but has also added additional information 
comparing the characteristics of coke fines and coke product.
--Active Lives of Landfills Used for Disposal of Petroleum Refining 
Wastes--Comments suggested that the active life for a landfill used by 
EPA in its modeling (20 years) was too short. In this Notice, EPA 
presents relevant data compiled from the industry survey, and 
calculations for the active lives of onsite landfills.
--Characterization of On-site Land Treatment Units--Some comments 
claimed that EPA had modeled land treatment units that were already 
regulated as hazardous waste units under RCRA, and as such, the release 
scenarios modeled were unlikely. In this Notice, EPA examines the 
regulatory status of on-site land treatment units and has compiled 
statistics on unit areas for nonhazardous units that managed the 
petroleum wastes under evaluation. These statistics are used in the 
revised nongroundwater analysis (see Supplemental Background Document; 
Nongroundwater Pathway Risk Assessment).
--Potential Impact of the Headworks Exemption--EPA proposed to modify 
the definition of hazardous waste to exempt wastewaters containing one 
of the wastes proposed for listing (clarified slurry oil storage tank 
sediment and/or in-line filter/separation solids), if the discharge of 
the wastewaters are regulated under the Clean Water Act. This is the 
so-called ``headworks exemption''. EPA took this action because some 
refineries manage residuals derived from this waste in their wastewater 
treatment facility during process vessel cleaning or tank washing. If 
this waste is listed as hazardous waste, this would cause all 
downstream wastewaters and treatment sludges to be derived from this 
waste and thus, carry the same waste code as the original waste (see 
261.3(a)(2)(iv)). Little to no risk reduction benefit would be achieved 
from regulating this material as a hazardous waste.
    Comments on this headworks exemption for CSO Sediment noted that it 
should also include wastewater from the other two wastes EPA proposed 
for listing (Spent Catalyst from Hydrotreating and Spent Catalyst from 
Hydrorefining). The comments pointed out that some petroleum refineries 
use water to cool and wash out the spent catalyst when the materials 
are removed from the catalytic units. Highly pressurized water is 
sometimes used to drill out catalyst that cannot be easily removed. EPA 
did not consider this practice when proposing the headworks exemption 
for the CSO sediment, and believes that the same rationale for 
proposing the exemption for wastewaters containing CSO sediment applies 
to wastewater containing the two spent catalyst wastes.
    If the listing of the spent catalyst wastes are made final, these 
drill and drainage waters would be derived-from hazardous wastes. Thus, 
facilities that engage in this practice would risk having all down 
stream wastewater treatment solids considered derived from hazardous 
wastes, if these wastewaters are discharged to the treatment system. 
This was not EPA's intent. Therefore, EPA is clarifying that the 
exemption proposed for 261.3(a)(2)(iv)(C) will also include wastewater 
containing the two spent catalyst wastes (K171 and K172), as well as 
the CSO sediment (K170). The Agency evaluated the potential impact of 
including wastewater from these two wastes in the headworks exemption, 
and believes that including them would not result in any significant 
risks in the downstream wastes. In the docket to this Notice, EPA 
presents additional analysis to evaluate the impact of such an 
exemption for wastewaters containing the three wastes proposed for 
listing.
    Comments also claimed that, as written, the headworks exemption for 
CSO Sediment (K170) would allow the discharge of more than merely 
wastewaters, and that refineries could also manage their original tank 
sludges in wastewater treatment systems. It was not EPA's intent to 
foster the discharge of all CSO sediments to wastewater treatment 
systems. The Agency envisions that after the tanks had been cleaned, 
facilities would wash the tanks out to remove the last residues and 
make the tanks suitable for inspection. Therefore, EPA is soliciting 
comments on clarifying the headworks exemption

[[Page 16750]]

for wastewaters containing the three petroleum wastes proposed for 
listing (K170, K171, and K172) so as to limit the exemption to dilute 
wastewaters. EPA is considering adding language to the proposed 
exemption clarifying that the exemption applies to wash waters from the 
clean out of units that contained CSO sediments (K170), Spent 
Hydrotreating Catalyst (K171), or Spent Hydrorefining Catalyst (K172).
     Data Impacting Proposed Universal Treatment Standards--EPA 
is including additional waste stabilization data in the docket to this 
Notice submitted to EPA for the calculation of treatment standards for 
antimony, nickel and vanadium as applied to two petroleum refining 
wastes that were proposed for listing (K171--Spent Catalysts from 
Hydrotreating, and K172--Spent Catalysts from Hydrorefining). See two 
documents in the docket entitled: Final Revised Calculation of 
Treatment Standards for Stabilization Using Data Obtained from Rollins 
Environmental's Highway 36 Commercial Waste Treatment Facility and 
GNB's Frisco, Texas Waste Treatment Facility; Memorandum from Howard 
Finkel, ICF Inc., to Anita Cummings, USEPA, March 1997; and High 
Temperature Metals Recovery (HTMR) Treatment Standards for Metals in 
Nonwastewater.

Clarifications and Corrections

    The Agency is also taking this opportunity to clarify several 
points in the proposed rule.

Headworks Exemption

    Comments on the headworks exemption stated that the proposal did 
not adequately justify this action. In this Notice, EPA shows that the 
proposed rule does, in fact, provide justification for this exemption 
in the Risk Assessment section III.F.2.(c). Specifically, in section 
III.F.2.(c)(2) entitled ``Disposal in Wastewater Treatment Plants,'' 
EPA discusses reasons why such disposal was not considered to warrant 
risk modeling, primarily due to existing regulatory coverage and the 
treatment and dilution that occurs in wastewater treatment plants (see 
60 FR 57759). Furthermore, the Agency is including in this Notice 
additional analysis it has undertaken to further describe the dilution 
and treatment that is expected to occur for this practice. This 
analysis is presented in the docket for this Notice (see Potential 
Impact of the Headworks Exemption, in the Supplemental Background 
Document; Listing Support Analyses; Petroleum Refining Process Listing 
Determination).

Jurisdictional Explanation of Off-Specification Product and Fines From 
Thermal Processes Used as Product

    EPA proposed not to list as hazardous Off-Specification Product and 
Fines from Thermal Processes. EPA's rationale for this is that the 
majority of off-specification product and fines are managed as coke 
product and thus are either not within the jurisdiction of RCRA or are 
exempt from RCRA regulation. Comments on this action stated that the 
proposal did not adequately explain the statutory or regulatory basis 
for the purported lack of jurisdiction over coke fines managed on a 
pile. EPA notes that the proposed rule does provide justification. 
However, further clarification is provided below.
    In responding to the commenter, the Agency must first clarify that 
only particle size distinguishes coke fines from other coke product. 
The majority of coke is removed from the coker by hydraulic drilling. 
Coke fines are the smaller pieces of coke generated during this 
process.
    Second, a jurisdictional distinction exists between coke fines that 
are produced from non-hazardous materials and coke fines produced from 
hazardous wastes (waste-derived fines). Fines generated from non-
hazardous materials are simply coke product, as would be expected since 
they are produced from the same coking drum. These fines are combined 
with other coke in a product pile where the material is stored prior to 
sales. Thus, EPA's belief that coke fines not derived from hazardous 
waste are beyond RCRA jurisdiction is based on the coke fines being 
coke product.
    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, 40 CFR 261.6(a)(3)(v). (See 
also RCRA section 3004(q)(2)(A)). EPA does not believe coke fails any 
hazardous waste characteristic, but invites comment if anyone has data 
to the contrary. Since the fines used as product are exempt, this 
material is outside the jurisdiction of the RCRA regulations. 
Therefore, EPA did not evaluate risks posed by such product uses of 
coke fines. In any event, EPA has data which indicate that the use of 
hazardous waste as feed material to the coker 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.
    As noted in the Additional Information section of this Notice, the 
docket contains additional analyses related to the similarity of coke 
fines to existing coke product, and the potential impact of recycling 
hazardous waste to the coker. EPA invites comments on these analyses.

Corrections to Proposal

    EPA inadvertently inserted some risk estimates in the preamble to 
the proposed rule that did not accurately reflect the risk calculations 
given in the background documents to the rule. To correct the record, 
EPA is including in today's Notice a comparison of the groundwater 
risks from landfill disposal that were published in the preamble to the 
proposed rule (see 60 FR 57747; November 20, 1995) with the correct (at 
that time) risk estimates given in the docket (``Background Document 
for Groundwater Pathway Analysis'', August 1995); this comparison is 
given in Table I. EPA also omitted from the preamble a risk estimate 
for one waste (Off-Specifications Product and Fines from Thermal 
Processes) that exceeded the 10-6 level. Table I also includes the 
risk estimates for this waste that were given in the background 
document to the proposal (See Appendix C in ``Background Document for 
Groundwater Pathway Analysis'').

Revised Risk Estimates

    Table II summarizes the revised risk estimates for the groundwater 
pathway for onsite and offsite landfill disposal, and contains the 
results for the revised high-end analyses, the Monte Carlo analyses, 
and the risks that would occur if constituents (benzene and arsenic) in 
the wastes were capped at the level specified in the TC. Note that all 
revised analyses for benzene represent the combined groundwater risk 
from ingestion and noningestion pathways (i.e., showering).
    Revised risk estimates for nongroundwater pathways for onsite and 
offsite land treatment are given in Table III, and reflect the 
modifications noted earlier in this Notice and described in detail in 
the docket (``Supplemental Background Document; Nongroundwater Pathway 
Risk Assessment''). The total carcinogenic risks are shown for various 
exposed populations and the methodologies used are fully explained in 
the supplemental background document.
    The revised risk analyses for the groundwater and nongroundwater 
pathways complement and confirm the

[[Page 16751]]

original analyses given in the proposed rule. EPA believes that the 
additional analyses completed for these wastes support the listing 
determinations contained in the proposed rule, and is not proposing any 
new listing decisions based on the new analyses.

Off-Specification Product and Fines From Thermal Processes

    While the preamble to the proposed rule did not contain a risk 
level for Off-Specification Product and Fines, the background document 
showed the risk results relied on by the Agency in the proposal as 1 
x  10-5. As shown in Table II, the revised high-end analysis for 
this waste yields risks that vary from 5  x  10-6 to 2  x  
10-5, depending on the approach used. The varying approaches used 
by EPA to calculate the risks in Table II are described in more detail 
in the docket (``Supplemental Groundwater Pathway Analyses''). The 
high-end risks for this waste are within the Agency's initial risk 
level of concern (see the proposed rule and the listing policy 
described in an earlier rulemaking for the Dyes and Pigments industry, 
66 FR 66072, December 22, 1994, and the proposed rule for petroleum, 60 
FR 57747).
    However, the estimated groundwater risk for this waste was based on 
entirely one chemical (benz(a)anthracene) that was detected in only one 
out of six aqueous leachate (TCLP) samples at a level 8-fold below the 
quantitation limit. (The quantitation limit is the lowest concentration 
that can be reliably achieved for specific samples within acceptable 
limits of precision and accuracy during routine laboratory operations.) 
The higher risk (2  x  10-5) arises when the value below the 
quantitation limit is used along with two other high-end parameters. 
The lower risk estimate (5  x  10-6) results if the one measured 
TCLP concentration is assumed to be one of the two high-end parameters. 
The highest risk from the Monte Carlo analysis is 5  x  10-6 at 
the 95th percentile. This means that in the numerous simulation runs 
(10,000), the risks were found to be below this level 95% of the time.
    After evaluating the additional analyses for Off-Specification 
Product and Fines, EPA does not consider the risk significant for a 
number of reasons. EPA believes that the higher risk is an overestimate 
because it is based on the detection in one out of six samples well 
below the quantitation limit. Thus, EPA has low confidence in this TCLP 
value and the subsequent modeling based on this number. Further 
analysis using the detected concentration as one of the two high-end 
parameters shows that the risk level drops to 5 x 10-6. The water 
solubility of this chemical is also very low, indicating that its 
aqueous concentration is likely to be very low. In addition, this 
chemical is tightly adsorbed to organic material in soils and sediment, 
indicating that the constituent is relatively immobile in groundwater. 
Therefore, it is highly unlikely that this waste would present a 
significant risk in a groundwater scenario. For all of these reasons, 
EPA continues to believe that this waste should not be listed.

Land Disposal Restrictions--Revised Treatment Standards for Spent 
Catalysts From Hydrotreating (K171) and Hydrorefining (K171)

    In the November 20, 1995 proposed rule, EPA proposed to apply the 
universal treatment standards (UTS) to the Petroleum Refining wastes 
proposed for listing (60 FR 57783). Commenters to that proposal have 
stated their inability to stabilize K171 and K171 nonwastewaters to the 
proposed 0.23 mg/L TCLP standard for vanadium. However, the commenters 
failed to provide data adequate for the calculation of an alternative 
treatment standard. Rather, the commenters provided data for the 
attempted stabilization of a catalyst that had not undergone extraction 
consistent with normal vanadium recovery. Data on stabilization alone 
does not reflect proper treatment for this waste; therefore, EPA does 
not consider these data adequate to modify the treatment standards. 
Subsequently, the Agency has obtained additional data suitable for the 
calculation of treatment standards. The Agency has used this new 
stabilization data, as well as data from high temperature metal 
recovery (HTMR), to recalculate treatment standards for these wastes. 
(See the docket for the two documents identified in the Additional 
Information section earlier in this Notice.) Based on these 
calculations, the proposed UTS standards as applied to K171 and K172 
for antimony, nickel, and vanadium would be revised to reflect the 
higher of the standards calculated for stabilized wastes and HTMR 
residues. The antimony standard would be decreased from 2.1 mg/L TCLP 
to 0.07 mg/L TCLP, the nickel standard would be increased from 5.0 mg/L 
TCLP to 13.6 mg/L TCLP, and the vanadium standard would be increased 
from 0.23 mg/L TCLP to 1.6 mg/L TCLP. The Agency is today noticing the 
data used to calculate these proposed revisions to the UTS standards as 
applied to the petroleum refinery wastes. The Agency requests any 
additional treatment data to re-evaluate or re-calculate the treatment 
standards based on EPA's BDAT Protocol (see USEPA, ``Final Best 
Demonstrated Available Technology (BDAT) Background Document for 
Quality Assurance/Quality Control Procedures and Methodology'', Office 
of Solid Waste, October 23, 1991). In the upcoming Land Disposal 
Restrictions Phase IV rulemaking, the Agency will discuss in detail the 
proposed use of the available data for developing Universal Treatment 
Standards on a national basis.

    Dated: March 28, 1997.
Elizabeth A. Cotsworth,
Acting Director, Office of Solid Waste.

  Table I.--Comparison of Original Federal Register Groundwater Risk Assessment Values With Background Document 
----------------------------------------------------------------------------------------------------------------
                                            Federal Register \1\                  Background  document \2\      
                                  ------------------------------------------------------------------------------
           Constituent                                                                              Off-site    
                                    On-site  landfill  Off-site  landfill   On-site  landfill       landfill    
----------------------------------------------------------------------------------------------------------------
                                        Spent Catalyst From Hydrotreating                                       
----------------------------------------------------------------------------------------------------------------
Benzene..........................  9E-06               1E-05               3E-05               4E-05            
Arsenic..........................  8E-06               1E-05               2E-05               3E-05            
----------------------------------------------------------------------------------------------------------------
                                        Spent Catalyst From Hydrorefining                                       
----------------------------------------------------------------------------------------------------------------
Benzene..........................  1E-05               2E-05               2E-05               3E-05            

[[Page 16752]]

                                                                                                                
Arsenic..........................  4E-05               6E-05               7E-05               1E-04            
----------------------------------------------------------------------------------------------------------------
                                         Crude Oil Storage Tank Sediment                                        
----------------------------------------------------------------------------------------------------------------
Benzene..........................  NA \3\              3E-05               NA                  5E-07            
----------------------------------------------------------------------------------------------------------------
                                     Unleaded Gasoline Storage Tank Sediment                                    
----------------------------------------------------------------------------------------------------------------
Benzene..........................  <1 E-06             2E-06               6E-7                4E-06            
----------------------------------------------------------------------------------------------------------------
                                              HF Alkylation Sludge                                              
----------------------------------------------------------------------------------------------------------------
Benzene..........................  6E-07               3E-06               8E-07               3E-06            
----------------------------------------------------------------------------------------------------------------
                                       Off-Specification Product and Fines                                      
----------------------------------------------------------------------------------------------------------------
Benzo(a)anthracene...............  NR \4\              NR                  3E-07               1E-05            
----------------------------------------------------------------------------------------------------------------
\1\ See 60 FR 57747, November 20, 1995.                                                                         
\2\ 2See ``Petroleum Refining Waste Listing Determination, Background Document for Groundwater Pathway          
  Analysis,'' Docket Document Identification No. F-95-PRLP-S0007.                                               
\3\ Not applicable.                                                                                             
\4\ None reported in Federal Register.                                                                          


                                   Table II.--Comparison of Groundwater Risks for Petroleum Residuals in Landfills \1\                                  
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                     Revised risks \2\                                            TC-capped risks \3\                   
                              --------------------------------------------------------------------------------------------------------------------------
         Constituent                  High-end risk \4\         Monte Carlo risk \5\ (95th%)          High-end risk           Monte Carlo risk (95th%)  
                              --------------------------------------------------------------------------------------------------------------------------
                                  Off-site         On-site        Off-site        On-site        Off-site       On-site        Off-site       On-site   
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Clarified Slurry Oil Tank Sediment                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
benzene......................  3E-06           3E-06           1E-06           3E-07          NA             NA             NA             NA           
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                 Hydrotreating Catalyst                                                                 
--------------------------------------------------------------------------------------------------------------------------------------------------------
benzene......................  5E-05           8E-05           1E-05           8E-06          1E-05          2E-05          4E-06          4E-06        
arsenic......................  7E-05           6E-05           1E-05           7E-06          NA             NA             NA             NA           
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                 Hydrorefining Catalyst                                                                 
--------------------------------------------------------------------------------------------------------------------------------------------------------
benzene......................  4E-05           4E-05           8E-06           8E-06          2E-05          2E-05          6E-06          6E-06        
arsenic......................  7E-04           4E-04           1E-04           1E-04          4E-04          4E-04          1E-04          1E-04        
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Crude Oil Storage Tank Sediment                                                            
--------------------------------------------------------------------------------------------------------------------------------------------------------
benzene......................  3E-05           NA              5E-06           NA             2E-05          NA             3E-06          NA           
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Unleaded Gasoline Storage Tank Sediment                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
benzene......................  5E-06           2E-06           2E-06           6E-07          3E-06          1E-06          1E-06          6E-07        
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                  HF Alkylation Sludge                                                                  
--------------------------------------------------------------------------------------------------------------------------------------------------------
benzene......................  6E-06           6E-06           2E-06           2E-07          NA             NA             2E-06          2E-07        
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                               Off-Specification Product and Fines From Thermal Processes                                               
--------------------------------------------------------------------------------------------------------------------------------------------------------
Benzo(a)-anthracene..........  5E-06 \6\       3E-06 \6\       4E-06 \7\       1E-07          NA             NA             NA             NA           
                               2E-05           2E-05           5E-06           .............  .............  .............  .............  .............
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Risk presented as carcinogenic risk.                                                                                                                
\2\ The revised risk includes an indirect risk from showering (6.05 x 10-5 risk per 1 mg/L benzene).                                                    
\3\ Input leaching rates were capped at TC regulatory levels for maximum allowable TCLP values for disposal in Subtitle D landfills (0.5 mg/L for       
  benzene and 5.0 mg/L for arsenic). ``NA'' means either the TC level was not exceeded, or no TC level exists for a chemical.                           
\4\ Risks were estimated using high-end values for two most sensitive parameters, while the remaining parameters are kept at median values.             

[[Page 16753]]

                                                                                                                                                        
\5\ Risks were estimated using Monte Carlo simulation runs; at the 95th percentile level, calculated risks were found to be below this level 95% of the 
  time.                                                                                                                                                 
\6\ The lower risk was obtained by using the one detected value (a ``J-value'' below the quantitation limit) as one of the two high-end parameters.     
\7\ The lower risk was obtained by using only the J-value in the Monte Carlo simulation runs.                                                           


                                    Table III.--Non-Groundwater Risks for Petroleum Residuals in Land Treatment Units                                   
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                On-site land treatment unit high-end total  carcinogen risk     Off-site land treatment unit high-end total  carcinogen 
                              ---------------------------------------------------------------                            risk                           
   Individual waste streams                                                                  -----------------------------------------------------------
                               Home  gardener       Adult        Subsistence    Subsistence        Home          Adult       Subsistence    Subsistence 
                                                  resident         farmer          fisher        gardener       resident        farmer         fisher   
--------------------------------------------------------------------------------------------------------------------------------------------------------
Clarified Slurry Oil Tank      1E-04           2E-05           2E-04           4E-05          3E-05          1E-05          2E-05          3E-05        
 Sediment.                                                                                                                                              
Crude Oil Tank Sediment......  3E-07           1E-07           4E-07           2E-07          2E-07          8E-08          2E-07          1E-07        
Unleaded Gasoline Tank         4E-07           9E-08           2E-07           1E-07          3E-07          9E-08          4E-07          1E-07        
 Sediment.                                                                                                                                              
Sulfur Complex Sludge........  1E-07           3E-08           6E-08           3E-08          5E-08          1E-08          4E-08          1E-08        
HF Alkylation Sludge.........  3E-08           7E-09           1E-08           8E-09          3E-08          7E-09          4E-08          9E-09        
Sulfuric Acid Alkylation       2E-09           1E-09           3E-10           2E-09          5E-10          3E-10          3E-10          7E-10        
 Sludge.                                                                                                                                                
Off-Spec Product & Fines.....  6E-08           3E-08           7E-08           4E-08          6E-08          2E-08          9E-08          4E-08        
--------------------------------------------------------------------------------------------------------------------------------------------------------

[FR Doc. 97-8816 Filed 4-7-97; 8:45 am]
BILLING CODE 6560-50-P