[Federal Register Volume 63, Number 236 (Wednesday, December 9, 1998)]
[Rules and Regulations]
[Pages 67787-67794]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-32567]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[AD-FRL-6197-8]
RIN 2060-AC19


National Emission Standards for Hazardous Air Pollutants for 
Source Categories: Organic Hazardous Air Pollutants From the Synthetic 
Organic Chemical Manufacturing Industry and Other Processes Subject to 
the Negotiated Regulation for Equipment Leaks; Rule Clarifications; 
Correction

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule: Correction.

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SUMMARY: On January 17, 1997, the EPA amended certain portions of the 
``National Emission Standards for

[[Page 67788]]

Hazardous Air Pollutants for Source Categories: Organic Hazardous Air 
Pollutants from the Synthetic Organic Chemical Manufacturing Industry 
and Other Processes Subject to the Negotiated Regulation for Equipment 
Leaks.'' This rule is commonly known as the Hazardous Organic NESHAP or 
the HON. Among the changes made to the rule in that action, the EPA 
added a definition for ``enhanced biological treatment systems or 
enhanced biological treatment processes'' to the rule and made 
clarifying revisions to appendix C of part 63. On August 22, 1997, the 
EPA proposed corrections to this definition in order to clarify its 
meaning and proposed revisions to appendix C of part 63 to reflect the 
clarification of the definition for ``enhanced biological treatment 
systems or enhanced biological treatment processes.'' The August 22, 
1997 document also proposed to revise the compliance demonstration 
procedures for biological treatment units to remove restrictions on the 
use of the batch test procedure. Today's action takes final action on 
those proposed amendments.
    These amendments to the rule will not change the basic control 
requirements of the rule or the level of health protection it provides. 
The rule requires new and existing major sources to control emissions 
of hazardous air pollutants to the level reflecting application of the 
maximum achievable control technology.

EFFECTIVE DATE: December 9, 1998.

ADDRESSES: Docket. Docket No. A-90-23, containing the supporting 
information for the original NESHAP and this action, are available for 
public inspection and copying between 8:00 a.m. and 5:30 p.m., Monday 
through Friday, at the EPA's Air and Radiation Docket and Information 
Center, Waterside Mall, Room M-1500, first floor, 401 M Street, SW, 
Washington, DC 20460, or by calling (202) 260-7548 or 260-7549. A 
reasonable fee may be charged for copying.

FOR FURTHER INFORMATION CONTACT: For general questions, contact Dr. 
Janet S. Meyer, Coatings and Consumer Products Group, at (919) 541-5254 
([email protected]). For technical questions on appendix C and 
wastewater provisions, contact Elaine Manning, Waste and Chemical 
Processes Group, telephone number (919) 541-5499 
([email protected]). The mailing address for the contacts 
is Emission Standards Division (MD-13), U.S. Environmental Protection 
Agency, Research Triangle Park, North Carolina 27711.

SUPPLEMENTARY INFORMATION:

I. Regulated Entities and Background Information:

A. Regulated Entities

    The regulated category and entities affected by this action 
include:

------------------------------------------------------------------------
            Category                  Examples of regulated entities
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Industry.......................  Synthetic organic chemical
                                  manufacturing industry (SOCMI) units,
                                  e.g., producers of benzene, toluene,
                                  or any other chemical listed in table
                                  1 of 40 CFR part 63, subpart F.
------------------------------------------------------------------------

    This table is not intended to be exhaustive but, rather, provides a 
guide for readers regarding entities likely to be interested in the 
revisions to the regulation affected by this action. This action is 
expected to be of interest to owners and operators subject to this rule 
who plan to use biological treatment to comply with control 
requirements for wastewater streams. Entities potentially regulated by 
the HON are those which produce as primary intended products any of the 
chemicals listed in table 1 of 40 CFR part 63, subpart F and are 
located at facilities that are major sources as defined in section 112 
of the Clean Air Act (the Act). Potentially regulated entities 
generally are companies that manufacture industrial organic chemicals 
and cyclic organic crude and intermediates. To determine whether your 
facility is regulated by this action, you should carefully examine all 
of the applicability criteria in 40 CFR 63.100. 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.

B. Background on the Rule

    On April 22, 1994 (59 FR 19402), and June 6, 1994 (59 FR 29196), 
the EPA published in the Federal Register the NESHAP for the SOCMI, and 
for several other processes subject to the equipment leaks portion of 
the rule. These regulations were promulgated as subparts F, G, H, and I 
in 40 CFR part 63, and are commonly referred to as the hazardous 
organic NESHAP, or the HON. Since the April 22, 1994 Federal Register 
publication, there have been several amendments to clarify various 
aspects of the rule. Readers should see the following Federal Register 
documents for more information: September 20, 1994 (59 FR 48175); 
October 24, 1994 (59 FR 53359); October 28, 1994 (59 FR 54131); January 
27, 1995 (60 FR 5321); April 10, 1995 (60 FR 18020); April 10, 1995 (60 
FR 18026); December 12, 1995 (60 FR 63624); February 29, 1996 (61 FR 
7716); June 20, 1996 (61 FR 31435); August 26, 1996 (61 FR 43698); 
December 5, 1996 (61 FR 64571); January 17, 1997 (62 FR 2721); and 
August 22, 1997 (62 FR 44608).
    In June 1994, the Chemical Manufacturers Association (CMA) and Dow 
Chemical Company (Dow) filed petitions for review of the promulgated 
rule in the U.S. Court of Appeals for the District of Columbia Circuit, 
Chemical Manufacturers Association v. EPA, 94-1463 and 94-1464 (D.C. 
Cir.) and Dow Chemical Company v. EPA, 94-1465 (D.C. Cir). The 
petitioners raised over 75 technical issues on the rule's structure and 
applicability. Issues were raised regarding details of the technical 
requirements, drafting clarity, and structural errors in the drafting 
of certain sections of the rule. On August 26, 1996, the EPA proposed 
clarifying and correcting amendments to subparts F, G, H, and I of part 
63 to address the issues raised by CMA and Dow on the April 1994 rule. 
On December 5, 1996 and January 17, 1997, the EPA took final action on 
the amendments proposed on August 26, 1996. Subsequently, the EPA 
determined that some revisions to the definition of ``enhanced 
biological treatment systems or enhanced biological treatment 
processes'' and to appendix C of part 63 might be appropriate. These 
revisions were proposed on August 22, 1997 at 62 FR 44608.

C. Public Comment on the August 22, 1997 Proposal

    Three comment letters were received on the August 22, 1997 Federal 
Register document that proposed changes to the rule. All comment 
letters received were from industry representatives and trade 
associations. While the commenters were supportive of the proposed rule 
amendments, they also expressed concerns with the clarity of the 
examples used in the preamble to describe systems that do and systems 
that do not meet the intent of the definition. The EPA has considered 
these suggestions and, where appropriate, has provided clarification of 
these examples in this document. The EPA has also developed a technical 
support document to provide additional information for use in 
evaluating whether a biological treatment unit meets the definition of 
``enhanced biological treatment system or enhanced biological treatment 
process.'' This document may be obtained from the Air and Radiation 
Docket and Information Center. It may also be obtained over the 
Internet at ``http://www.epa.gov/ttn/

[[Page 67789]]

oarpg/ramain.html.'' The Technology Transfer Network (TTN) provides 
information and technology exchange in various areas of air pollution 
control, including copies of rules and supporting documents. If more 
information on TTN is needed, contact the systems operator at (919) 
541-5384.

D. Judicial Review

    Under Section 307(b)(1) of the Act, judicial review of this final 
action is available only on the filing of a petition for review in the 
U.S. Court of Appeals for the District of Columbia Circuit within 60 
days of today's publication of this final rule. Under Section 307(b)(2) 
of the Act, the requirements that are subject to today's publication 
may not be challenged later in civil or criminal proceedings brought by 
the EPA to enforce these requirements.

II. Clarification of Definition of Enhanced Biological Treatment 
System or Enhanced Biological Treatment Process

    The August 26, 1996 proposed changes to the wastewater treatment 
provisions of the HON included provisions that provided easier 
compliance demonstration options for well-mixed activated sludge 
systems that are used to control readily biodegraded compounds. In that 
proposed change to the April 1994 final rule, the compounds listed in 
table 9 of subpart G were divided into three lists; these lists were 
presented in table 36 of subpart G. In the proposal, a performance 
evaluation would not have been required for an activated sludge system 
if it met the definition of ``enhanced biological treatment system or 
enhanced biological treatment process'' and if the unit was controlling 
wastewater streams that contained only list 1 compounds. The August 
1996 proposed revisions to the rule also required a performance 
demonstration for activated sludge systems used to treat a combination 
of list 1 and list 2 and/or list 3 compounds.
    The August 1996 proposal defined an enhanced biological treatment 
system as

an aerated treatment unit(s) that contains biomass suspended in 
water followed by a clarifier that removes biomass from the treated 
water and recycles recovered biomass to the aeration unit. The mixed 
liquor volatile suspended solids (biomass) is greater than 1 
kilogram per cubic meter throughout each aeration unit. The biomass 
is suspended and aerated in the water of the aeration unit(s) by 
either submerged air flow or mechanical agitation.

This definition of ``enhanced biological treatment system or enhanced 
biological treatment process'' was intended to reflect the basis for 
the simplified compliance approach for some systems. The three lists of 
compounds in table 36 of subpart G were developed by modeling 
performance of an activated sludge system that was a thoroughly mixed 
biological treatment unit. (A thoroughly mixed or completely mixed 
system is a biological treatment unit where biomass and wastewater 
entering the tank are dispersed quickly throughout the tank such that 
the system achieves or approaches uniform characteristics throughout 
the tank (Docket number A-90-23, item VII-B-8).) After the August 1996 
proposal, the EPA learned that some were interpreting the proposed 
definition of ``enhanced biological treatment system or biological 
treatment process'' to apply more broadly than intended. In the January 
17, 1997 final rule, the phrase ``homogeneously distributed'' was added 
to the second sentence of the definition to clarify the EPA's intent to 
define a well-mixed biological treatment unit. The EPA thought that 
this revision would better reflect the modeling and clarify the EPA's 
intent to limit the types of biological treatment units that could use 
the simplified compliance option to systems that were completely back 
mixed. The EPA also believed that this change did not alter the meaning 
of the term.
    Following publication of the January 17, 1997 final rule, the EPA 
learned that industry representatives were concerned that the revised 
definition could be read to require absolute uniformity in the biomass 
concentration. These industry representatives pointed out that they 
believed that such a reading of the definition could preclude any 
system from using the simplified compliance approach and the 
performance evaluation exemption. It was not the EPA's intent that the 
phrase ``homogeneously distributed'' be interpreted this narrowly. 
Therefore, on August 22, 1997 the EPA proposed clarifying changes to 
the definition of ``enhanced biological treatment system or enhanced 
biological treatment process'' and proposed parallel conforming changes 
to appendix C to part 63.
    Today's action promulgates without any changes, the definition, 
proposed in the August 22, 1997 document, of ``enhanced biological 
treatment system or enhanced biological treatment process.'' That 
definition reads as follows:

    Enhanced biological treatment system or enhanced biological 
treatment process means an aerated, thoroughly mixed treatment 
unit(s) that contains biomass suspended in water followed by a 
clarifier that removes biomass from the treated water and recycles 
recovered biomass to the aeration unit. The mixed liquor volatile 
suspended solids (biomass) is greater than 1 kilogram per cubic 
meter throughout each aeration unit. The biomass is suspended and 
aerated in the water of the aeration unit(s) by either submerged air 
flow or mechanical agitation. A thoroughly mixed treatment unit is a 
unit that is designed and operated to approach or achieve uniform 
biomass distribution and organic compound concentration throughout 
the aeration unit by quickly dispersing the recycled biomass and the 
wastewater entering the unit.

    The description of a ``thoroughly mixed treatment unit'' in the 
definition is intended to convey the concept of an activated sludge 
system that is designed and operated to approach or achieve the 
characteristics of a completely back mixed system. Because the EPA does 
not intend the definition to allow only systems with perfect uniformity 
in characteristics, a ``thoroughly mixed treatment unit'' is described 
as a unit that is ``designed and operated to approach or achieve 
uniform biomass distribution and organic compound concentration.'' This 
description is intended to recognize that well-designed complete mix 
systems may still have small insignificant stagnant zones or other 
minor deviations from complete mixing. This was the intended meaning of 
the definition promulgated on January 17, 1997 and is also the intended 
meaning of the definition promulgated in today's action.
    The EPA received three comment letters in response to the August 
22, 1997 Federal Register proposal. While all of the commenters agreed 
with the proposed definition of ``enhanced biological treatment system 
or enhanced biological treatment process,'' they expressed a concern 
that the examples in the preamble did not fully reflect the intent of 
the definition. The objections to the first example in the August 22, 
1997 preamble were that the discussion referred to the units as having 
``uniform'' characteristics instead of ``approaching or achieving 
uniform characteristics'' as described in the proposed definition. In 
the example, the system that was described as meeting the enhanced 
biological treatment system definition was characterized as a well-
designed, well-operated, and well-maintained activated sludge system 
that has uniform characteristics in the aeration unit. The EPA agrees 
with the commenters that this example only illustrates a hypothetical 
ideal system and it would have been more useful to have described the 
unit as one that ``approaches uniformity throughout the aeration unit'' 
instead of as one that is ``uniform.'' The EPA recognizes that it is

[[Page 67790]]

unrealistic to believe that aeration units will have completely uniform 
characteristics and also recognizes even well-designed complete mix 
systems may still have small insignificant stagnant zones or other 
minor deviations from complete mixing. Other relevant aspects of this 
first example are that the biological treatment unit of this enhanced 
biological treatment system would be thoroughly mixed throughout the 
unit and biomass and wastewater entering the unit would be quickly 
dispersed throughout the unit. The design of the unit would be such 
that thorough mixing and quick dispersion of the biomass and wastewater 
entering the unit would occur. The design and operation of the 
biological treatment unit would also take into account mixing, quick 
dispersion of the biomass and wastewater entering the unit, and the 
location of the wastewater inlet with regards to intake suction of 
surface aerators and the opportunity for volatilization prior to 
biodegradation.
    In the second example in the proposal preamble, the EPA's intent 
was to make a general statement concerning the relationship between 
system size and location of the inlet and the number of inlets. The 
following adjustment to the example clarifies the intent. In smaller 
size units that approach a complete back mixed system, thorough mixing 
and quick dispersion may be achieved with a round or square tank and 
only one influent. For larger scale systems that have more difficulty 
reaching the complete back mixed conditions, thorough mixing and quick 
dispersion could be achieved by having multiple influents of biomass 
and wastewater. In either case, the biological treatment unit would 
approach or achieve uniform distribution of organic concentration and 
mixed liquor volatile suspended solids (MLVSS) throughout the vessel 
where the biological reactions occur.
    A plug-flow system is an example of a biological treatment system 
that does not meet the enhanced biological treatment system definition. 
Plug-flow systems typically occur in long tanks with a high length-to-
width ratio in which longitudinal dispersion is minimal or absent 
(Docket number A-90-23, item VII-B-8). Plug-flow systems are not 
considered acceptable units for the performance test exemption because 
they tend to have higher air emissions at the front of the system where 
the concentration is higher. The modeling used to develop the 
simplified compliance approach for systems meeting the definition for 
an ``enhanced biological treatment system or enhanced biological 
treatment process'' did not address plug-flow systems. The EPA did not 
evaluate the performance of plug-flow systems in the development of the 
three lists for the simplified compliance approach due to the 
complexity of plug-flow systems. The wide range in characteristics of 
plug-flow systems led the EPA to conclude that these systems had to be 
modeled using site-specific characteristics. Consequently, these 
systems are required to demonstrate compliance through use of the 
procedures in appendix C. The exclusion of plug-flow biological 
treatment systems from the simplified compliance demonstration should 
not be interpreted as implying that a well designed and operated plug-
flow biological treatment system would not achieve the required removal 
of a compound and, thus, not represent an acceptable means of 
compliance. If correctly evaluated through the applicable procedures in 
appendix C to part 63, they can be acceptable.
    Examples of additional biological systems that would not meet the 
enhanced biological treatment system definition would be units that are 
not thoroughly mixed throughout the aeration unit and that have large 
concentration gradients between the inlet and the outlet of the 
aeration unit. Such biological units do not quickly disperse the 
biomass and wastewater entering the unit throughout the unit and tend 
to concentrate the volatile organics in a zone with relatively high air 
stripping rates.
    Two commenters also objected to an example in which closeness of 
influent to the aerators was cited as a factor that would prevent a 
system from meeting the definition of enhanced biological treatment 
system. The commenters understood the example to be introducing the use 
of a criterion of the distance between the influent and an aerator as a 
de facto measure of poor mixing. The commenters pointed out that if the 
system achieves quick dispersion of the biomass and wastewater entering 
the unit, the spatial distance between any aerators or other mixing 
equipment and the influent is inconsequential. One of the commenters 
noted that simple spatial distance is not the important issue, rather 
the issue is whether the influent, recycle biomass, and basin contents 
are mixed such that the material which is aerated is a mixture of these 
materials rather than the raw influent. One of the two commenters 
requested that the EPA delete this example and address this issue 
through guidance. Both commenters also requested that the EPA state 
that the examples in the preamble are not intended to provide guidance 
regarding determinations of whether a system meets the definition of an 
``enhanced biological treatment system or enhanced biological treatment 
process.''
    As a result of these comments, the EPA realized that the example 
lacked sufficient specificity to explain the basis for the EPA's 
concern. The EPA is therefore correcting this example to read:

    Other examples of units that would not meet the definition 
include a unit where the influent is introduced close to the intake 
suction of a surface aerator, increasing the opportunity for 
volatilization prior to biodegradation, and a unit where the 
influent is introduced close to a discharge point such that 
channeling occurs.

    Introduction of the influent close to the intake suction of a 
surface aerator is of concern because the more concentrated influent 
stream may be picked up and sprayed through the air thereby increasing 
losses due to volatilization. It is recommended that the influent be 
introduced in the return stream of the aerator to ensure mixing of the 
influent and destruction by the biomass before the material is sprayed 
through the air by the surface aerators.
    The EPA agrees with the commenters' suggestion that the EPA should 
provide detailed technical guidance for determining whether a 
biological treatment unit meets the definition of ``enhanced.'' This is 
important because the discussion in this document is limited to key 
factors and it is necessary to consider all factors that can influence 
mixing time and rate of volatilization before concluding that a system 
meets the criteria in the definition for enhanced biological treatment 
system. The EPA has developed additional information to assist in the 
determination of whether a biological treatment unit meets the enhanced 
biological treatment system definition. The additional information is 
available from the Air and Radiation Docket and Information Center and 
is also available through the Internet on the TTN website at ``http://
www.epa.gov/ttn.'' The EPA is presently working on additional 
information to assist in compliance demonstrations for biological 
treatment units that are not thoroughly mixed treatment units and, 
hence, do not meet the definition of enhanced biological treatment 
system. When this information is available, it will be available from 
the Air and Radiation Docket and Information Center and from the TTN.

[[Page 67791]]

III. Revisions to Requirements for Determining Site-Specific 
Fraction Biodegraded

    All comments were supportive of the proposed amendments to revise 
the requirements in subpart G for determining site-specific fraction 
biodegraded (Fbio). Today's action issues the proposed 
revisions without change. Specifically, the EPA is revising 
Sec. 63.145(h)(2) to allow use of the batch test procedure in appendix 
C for any type of biological treatment system. Today's action also 
revises table 36 by combining the list 2 and list 3 compounds into a 
new list 2 in table 36. These changes are being made to Sec. 63.145(h) 
to provide more flexibility and to simplify this section of the rule.

IV. Revisions to Appendix C To Part 63

    All comments were supportive of the proposed amendments to appendix 
C to part 63 to reflect the proposed revision of the definition for 
``enhanced biological treatment system or enhanced biological treatment 
process.'' Today's action issues those proposed revisions without 
change.

V. Administrative Requirements

A. Docket

    The docket is an organized and complete file of all the information 
considered by the EPA in the development of this rulemaking. The docket 
is a dynamic file, because material is added throughout the rulemaking 
development. The docketing system is intended to allow members of the 
public and industries involved to readily identify and locate documents 
so that they can effectively participate in the rulemaking process. 
Along with the proposed and promulgated standards and their preambles, 
the contents of the docket, except for certain interagency documents, 
will serve as the record for judicial review. (See the Act section 
307(d)(7)(A).)

B. Paperwork Reduction Act

    The Office of Management and Budget (OMB) has approved the 
information collection requirements contained in the rule under the 
provisions of the Paperwork Reduction Act, 44 U.S.C. 3501, et seq. and 
has assigned OMB control number 2060-0282. An Information Collection 
Request (ICR) document was prepared by the EPA (ICR No. 1414.03) and a 
copy may be obtained from Sandy Farmer, OPPE Regulatory Information 
Division; U.S. Environmental Protection Agency (2137); 401 M St., SW; 
Washington, DC 20460 or by calling (202) 260-2740.
    These revisions to the rule do not change the information 
collection requirements of the rule, and the currently approved OMB 
ICRs are still in force for the amended rule. The changes consist of 
revised definitions, alternative test procedures, and clarifications of 
requirements. The changes are not additional requirements and do not 
increase the information collection burden. Consequently, the ICR has 
not been revised for these amendments to the rule.
    An agency may not conduct or sponsor, and a person is not required 
to respond to a collection of information unless it displays a 
currently valid OMB control number. The OMB control numbers for the 
EPA's regulations are listed in 40 CFR part 9 and 48 CFR Chapter 15.

C. Executive Order 12866 Review

    Under Executive Order 12866, the EPA must determine whether a 
regulatory action is ``significant'' and, therefore, subject to OMB 
review and the requirements of the Executive Order. The Executive Order 
defines ``significant'' regulatory action as one that is likely to lead 
to a rule that may:
    (1) Have an annual effect on the economy of $100 million or more or 
adversely affect in a material way the economy, a sector of the 
economy, productivity, competition, jobs, the environment, public 
health or safety in State, local, or tribal governments or communities;
    (2) create a serious inconsistency or otherwise interfere 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; or
    (4) raise novel legal or policy issues arising out of legal 
mandates, the President's priorities, or the principles set forth in 
the Executive Order.
    Pursuant to the terms of the Executive Order, the EPA has 
determined that this final rule is not a ``significant regulatory 
action'' within the meaning of the Executive Order. The amendments 
issued today clarify the rule and remove restrictions on use of an 
alternative test procedure. These amendments do not add any new control 
requirements. Therefore, this regulatory action is considered ``not 
significant'' and OMB review is not required.

D. Regulatory Flexibility/Small Business Regulatory Enforcement 
Fairness Act of 1996

    The Regulatory Flexibility Act (RFA) of 1980 (5 U.S.C. 601, et 
seq.), as amended by the Small Business Regulatory Enforcement Fairness 
Act (SBREFA) of 1996, requires the EPA to give special consideration to 
the effect of Federal regulations on small entities and to consider 
regulatory options that might mitigate any such impacts. The EPA is 
required to prepare a regulatory flexibility analysis and coordinate 
with small entity stakeholders if the Agency determines that a rule 
will have a significant economic impact on a substantial number of 
small entities.
    The EPA has determined that it is not necessary to prepare a 
regulatory flexibility analysis in connection with this final amendment 
to the rule. The EPA has also determined that this amendment will not 
have a significant economic impact on a substantial number of small 
entities. Small entities include small businesses, small not-for-profit 
enterprises, and small government jurisdictions. See the April 22, 1994 
Federal Register (59 FR 19449) for the basis for this determination. 
The changes to the rule merely clarify existing requirements and 
therefore, do not create any additional burden for any of the regulated 
entities.

E. Submission to Congress and the General Accounting Office

    The Congressional Review Act, 5 U.S.C. Sec. 801, et seq., as added 
by the SBREFA 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. The EPA will submit a 
report containing this rule and other required information to the 
United States Senate, the United States House of Representatives, and 
the Comptroller General of the United States prior to publication of 
the rule in the Federal Register. A Major rule cannot take effect until 
60 days after it is published 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 December 9, 1998.

F. Unfunded Mandates Reform Act

    Under section 202 of the Unfunded Mandates Reform Act of 1995 
(``Unfunded Mandates Act''), signed into law on March 22, 1995, the EPA 
must prepare a budgetary impact statement to accompany any proposed or 
final rule that includes a Federal mandate that may result in estimated 
costs to State, local, or tribal governments in the aggregate, or to 
the private sector, of $100 million or more in any one year. Under 
section 205, the EPA must select the least costly, most cost-effective, 
or least burdensome

[[Page 67792]]

alternative that achieves the objectives of the rule and is consistent 
with statutory requirements. 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.
    The EPA has determined that the action promulgated today 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 in any one year. Therefore, the 
requirements of sections 202 and 205 of the Unfunded Mandates Act do 
not apply to this action. The EPA has likewise determined that the 
action promulgated today does not include any regulatory requirements 
that might significantly or uniquely affect small governments. Thus, 
today's action is not subject to the requirements of section 203 of the 
Unfunded Mandates Act.

G. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (the NTTAA), Pub. L. No. 104-113, Sec. 12(d) (15 U.S.C. 272 
note), directs the EPA 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. The NTTAA requires the 
EPA to provide Congress, through OMB, explanations when the Agency 
decides not to use available and applicable voluntary consensus 
standards.
    This regulatory action amends a definition and makes clarifying 
revisions to appendix C of part 63 to reflect the clarification of the 
definition. Thus, this action does not involve any technical standards 
that would require the EPA to consider voluntary consensus standards 
pursuant to section 12(d) of the NTTAA.

H. Executive Order 12875: Enhancing Intergovernmental Partnership

    Under Executive Order 12875, EPA may not issue a regulation that is 
not required by statute and that creates a mandate upon a State, local 
or tribal government, unless the Federal government provides the funds 
necessary to pay the direct compliance costs incurred by those 
governments, or EPA consults with those governments. If EPA complies by 
consulting, Executive Order 12875 requires EPA to provide to the Office 
of Management and Budget a description of the extent of EPA's prior 
consultation with representatives of affected State, local and tribal 
governments, the nature of their concerns, copies of any written 
communications from the governments, and a statement supporting the 
need to issue the regulation. In addition, Executive Order 12875 
requires EPA to develop an effective process permitting elected 
officials and other representatives of State, local and tribal 
governments ``to provide meaningful and timely input in the development 
of regulatory proposals containing significant unfunded mandates.''
    Today's rule does not create a mandate on State, local or tribal 
governments. The rule does not impose any enforceable duties on these 
entities. Accordingly, the requirements of section 1(a) of Executive 
Order 12875 do not apply to this rule.

I. Executive Order 13045: Protection of Children From Environmental 
Health Risks and Safety Risks

    Executive Order 13045, ``Protection of Children from Environmental 
Health Risks and Safety Risks'' (62 FR 19885, April 23, 1997), applies 
to any rule that: (1) is determined to be ``economically significant'' 
as defined under Executive Order 12866, and (2) concerns an 
environmental health or safety risk that the EPA has reason to believe 
may have a disproportionate effect on children. If the regulatory 
action meets both criteria, the EPA 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 considered not ``economically significant'' as 
defined under Executive Order 12866 and, therefore, is not subject to 
Executive Order 13045.

J. Executive Order 13084: Consultation and Coordination With Indian 
Tribal Governments

    Under Executive Order 13084, EPA may not issue a regulation that is 
not required by statute, that significantly or uniquely affects the 
communities of Indian tribal governments, and that imposes substantial 
direct compliance costs on those communities, unless the Federal 
government provides the funds necessary to pay the direct compliance 
costs incurred by the tribal governments, or EPA consults with those 
governments. If EPA complies by consulting, Executive Order 13084 
requires EPA to provide to the Office of Management and Budget, in a 
separately identified section of the preamble to the rule, a 
description of the extent of EPA's prior consultation with 
representatives of affected tribal governments, a summary of the nature 
of their concerns, and a statement supporting the need to issue the 
regulation. In addition, Executive Order 13084 requires EPA to develop 
an effective process permitting elected officials and other 
representatives of Indian tribal governments ``to provide meaningful 
and timely input in the development of regulatory policies on matters 
that significantly or uniquely affect their communities.''
    Today's rule does not significantly or uniquely affect the 
communities of Indian tribal governments. The amendments issued today 
clarify the rule and remove restrictions on use of an alternative test 
procedure and do not add any new requirements. Accordingly, the 
requirements of section 3(b) of Executive Order 13084 do not apply to 
this rule.

List of Subjects in 40 CFR Part 63

    Environmental protection, Air pollution control, Hazardous 
substances, Reporting and recordkeeping requirements.

    Dated: November 30, 1998.
Carol M. Browner,
Administrator.
    For the reasons set out in the preamble, title 40 chapter I, part 
63 of the Code of Federal Regulations is amended as follows:

PART 63--[AMENDED]

    1. The authority citation for part 63 continues to read as follows:

    Authority: 42 U.S.C. 7401, et seq.

    2. Section 63.111 is amended by revising the definition of 
``enhanced biological treatment system or enhanced biological treatment 
process'' to read as follows:


Sec. 63.111  Definitions.

* * * * *
    Enhanced biological treatment system or enhanced biological 
treatment process means an aerated, thoroughly mixed treatment unit(s) 
that contains biomass suspended in water followed by a clarifier that 
removes biomass from the treated water and recycles recovered biomass 
to the aeration unit. The mixed liquor volatile suspended solids 
(biomass) is greater than 1 kilogram per cubic meter throughout each 
aeration unit. The biomass is suspended and aerated in the water of the 
aeration

[[Page 67793]]

unit(s) by either submerged air flow or mechanical agitation. A 
thoroughly mixed treatment unit is a unit that is designed and operated 
to approach or achieve uniform biomass distribution and organic 
compound concentration throughout the aeration unit by quickly 
dispersing the recycled biomass and the wastewater entering the unit.
* * * * *
    3. Section 63.145 is amended by revising paragraph (h) introductory 
text and paragraph (h)(2) to read as follows:


Sec. 63.145  Process wastewater provisions--test methods and procedures 
to determine compliance.

* * * * *
    (h) Site-specific fraction biodegraded (Fbio). The 
compounds listed in table 9 of this subpart are divided into two sets 
for the purpose of determining whether Fbio must be 
determined, and if Fbio must be determined, which procedures 
may be used to determine compound-specific kinetic parameters. These 
sets are designated as lists 1 and 2 in table 36 of this subpart.
* * * * *
    (2) Fbio determination. If a biological treatment 
process does not meet the requirement specified in paragraph (h)(1)(i) 
of this section, the owner or operator shall determine Fbio 
for the biological treatment process using the procedures in appendix C 
to part 63, and paragraph (h)(2)(ii) of this section. If a biological 
treatment process meets the requirements of paragraph (h)(1)(i) of this 
section but does not meet the requirement specified in paragraph 
(h)(1)(ii) of this section, the owner or operator shall determine 
Fbio for the biological treatment process using the 
procedures in appendix C to part 63, and paragraph (h)(2)(i) of this 
section.
    (i) Enhanced biological treatment processes. If the biological 
treatment process meets the definition of ``enhanced biological 
treatment process'' in Sec. 63.111 of this subpart and the wastewater 
streams include one or more compounds on list 2 of table 36 of this 
subpart that do not meet the criteria in paragraph (h)(1)(ii) of this 
section, the owner or operator shall determine fbio for the 
list 2 compounds using any of the procedures specified in appendix C of 
40 CFR part 63. (The symbol ``fbio'' represents the site 
specific fraction of an individual Table 8 or Table 9 compound that is 
biodegraded.) The owner or operator shall calculate fbio for 
the list 1 compounds using the defaults for first order biodegradation 
rate constants (K1) in table 37 of subpart G and follow the 
procedure explained in form III of appendix C, 40 CFR part 63, or any 
of the procedures specified in appendix C, 40 CFR part 63.
    (ii) Biological treatment processes that are not enhanced 
biological treatment processes. For biological treatment processes that 
do not meet the definition for ``enhanced biological treatment 
process'' in Sec. 63.111 of this subpart, the owner or operator shall 
determine the fbio for the list 1 and 2 compounds using any 
of the procedures in appendix C to part 63, except procedure 3 (inlet 
and outlet concentration measurements). (The symbol ``fbio'' 
represents the site specific fraction of an individual Table 8 or Table 
9 compound that is biodegraded.)
* * * * *
    4. Table 36 of appendix to subpart G is revised to read as follows:

Appendix to Subpart G--Tables and Figures

* * * * *

  Table 36.--Compound Lists Used for Compliance Demonstrations for Enhanced Biological Treatment Processes (See
                                                Sec.  63.145(h))
----------------------------------------------------------------------------------------------------------------
               List 1                                                   List 2
----------------------------------------------------------------------------------------------------------------
Acetonitrile........................  Acetaldehyde.
Acetophenone........................  Acrolein.
Acrylonitrile.......................  Allyl Chloride.
Biphenyl............................  Benzene.
Chlorobenzene.......................  Benzyl Chloride,
Dichloroethyl Ether.................  Bromoform.
Diethyl Sulfate.....................  Bromomethane.
Dimethyl Sulfate....................  Butadiene 1,3.
Dimethyl Hydrazine 1,1..............  Carbon Disulfide.
Dinitrophenol 2,4...................  Carbon Tetrachloride
Dinitrotoluene 2,4..................  Chloroethane (ethyl chloride).
Dioxane 1,4.........................  Chloroform.
Ethylene Glycol Monobutyl...........  Chloroprene.
Ether Acetate.......................
Ethylene Glycol Monomethyl..........  Cumene (isopropylbenzene).
Ether Acetate.......................
Ethylene Glycol Dimethyl Ether......  Dibromoethane 1,2.
Hexachlorobenzene...................  Dichlorobenzene 1,4.
Isophorone..........................  Dichloroethane 1,2.
Methanol............................  Dichloroethane 1,1 (ethylidene dichloride).
Methyl Methacrylate.................  Dichloroethene 1,1 (vinylidene chloride).
Nitrobenzene........................  Dichloropropane 1,2.
Toluidine...........................  Dichloropropene 1,3.
Trichlorobenzene 1,2,4..............  Dimethylaniline N,N.
Trichlorophenol 2,4,6...............  Epichlorohydrin.
Triethylamine.......................  Ethyl Acrylate.
                                      Ethylbenzene.
                                      Ethylene Oxide.
                                      Ethylene Dibromide.
                                      Hexachlorobutadiene.
                                      Hexachloroethane.
                                      Hexane-n.
                                      Methyl Isobutyl Ketone.
                                      Methyl Tertiary Butyl Ether.
                                      Methyl Ethyl Ketone, (2-butanone).
                                      Methyl Chloride.

[[Page 67794]]

 
                                      Methylene Chloride (dichloromethane).
                                      Naphthalene.
                                      Nitropropane 2
                                      Phosgene.
                                      Propionaldehyde.
                                      Propylene Oxide.
                                      Styrene.
                                      Tetrachloroethane 1,1,2,2.
                                      TolueneTrichloroethane 1,1,1 (methyl chloroform).
                                      Trichloroethane 1,1,2.
                                      Trichloroethylene.
                                      Trimethylpentane 2,2,4.
                                      Vinyl Chloride.
                                      Vinyl Acetate.
                                      Xylene-m.
                                      Xylene-o.
                                      Xylene-p.
----------------------------------------------------------------------------------------------------------------

* * * * *
    5. Section I of appendix C to part 63 is revised to read as 
follows:

Appendix C to Part 63--Determination of the Fraction Biodegraded 
(Fbio) in a Biological Treatment Unit

I. Purpose

    The purpose of this appendix is to define the procedures for an 
owner or operator to use to calculate the site specific fraction of 
organic compounds biodegraded (Fbio) in a biological 
treatment unit. If an acceptable level of organic compounds is 
destroyed rather than emitted to the air or remaining in the 
effluent, the biological treatment unit may be used to comply with 
the applicable treatment requirements without the unit being covered 
and vented through a closed vent system to an air pollution control 
device.
    The determination of Fbio shall be made on a system 
as it would exist under the rule. The owner or operator should 
anticipate changes that would occur to the wastewater flow and 
concentration of organics, to be treated by the biological treatment 
unit, as a result of enclosing the collection and treatment system 
as required by the rule.
    The forms presented in this appendix are designed to be applied 
to thoroughly mixed treatment units. A thoroughly mixed treatment 
unit is a unit that is designed and operated to approach or achieve 
uniform biomass distribution and organic compound concentration 
throughout the aeration unit by quickly dispersing the recycled 
biomass and the wastewater entering the unit. Systems that are not 
thoroughly mixed treatment units should be subdivided into a series 
of zones that have uniform characteristics within each zone. The 
number of zones required to characterize a biological treatment 
system will depend on the design and operation of the treatment 
system. Each zone should then be modeled as a separate unit. The 
amount of air emissions and biodegradation from the modeling of 
these separate zones can then be added to reflect the entire system.
* * * * *

Appendix C  [Amended]

    6. Section III of appendix C of part 63, the second paragraph after 
(4) is revised to read as follows:

III. Procedures for Determination of fbio

* * * * *
    (4) * * *
* * * * *
    Select one or more appropriate procedures from the four listed 
above based on the availability of site specific data. If the 
facility does not have site-specific data on the removal efficiency 
of its biological treatment unit, then Procedure 1 or Procedure 4 
may be used. Procedure 1 allows the use of a bench top bioreactor to 
determine the first-order biodegradation rate constant. An owner or 
operator may elect to assume the first order biodegradation rate 
constant is zero for any regulated compound(s) present in the 
wastewater. Procedure 4 explains two types of batch tests which may 
be used to estimate the first order biodegradation rate constant. An 
owner or operator may elect to assume the first order biodegradation 
rate constant is zero for any regulated compound(s) present in the 
wastewater. Procedure 3 would be used if the facility has, or 
measures to determine, data on the inlet and outlet individual 
organic compound concentration for the biological treatment unit. 
Procedure 3 may only be used on a thoroughly mixed treatment unit. 
Procedure 2 is used if a facility has or obtains performance data on 
a biotreatment unit prior to and after addition of the microbial 
mass. An example where Procedure 2 could be used, is an activated 
sludge unit where measurements have been taken on inlet and exit 
concentration of organic compounds in the wastewater prior to 
seeding with the microbial mass and start-up of the unit. The flow 
chart in figure 1 outlines the steps to use for each of the 
procedures.
* * * * *
    7. In appendix C of part 63, section III, in the second sentence of 
C. Inlet and Outlet Concentration Measurements (Procedure 3), the 
phrase ``uniform well-mixed or completely mixed system'' is revised to 
read ``thoroughly mixed treatment unit.''

[FR Doc. 98-32567 Filed 12-8-98; 8:45 am]
BILLING CODE 6560-50-P