[Federal Register Volume 60, Number 56 (Thursday, March 23, 1995)]
[Rules and Regulations]
[Pages 15366-15425]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-6671]



      

[[Page 15365]]

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Part III





Environmental Protection Agency





_______________________________________________________________________



40 CFR 9, 122, 123, 131, and 132



Final Water Quality Guidance for the Great Lakes System; Final Rule

  Federal Register / Vol. 60, No. 56 / Thursday, March 23, 1995 / Rules 
and Regulations   
[[Page 15366]] 

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 9, 122, 123, 131, and 132

[FRL-5173-7]
RIN 2040-AC08


Final Water Quality Guidance for the Great Lakes System

AGENCY: U.S. Environmental Protection Agency.

ACTION: Final rule.

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

SUMMARY: EPA is publishing Final Water Quality Guidance for the Great 
Lakes System. Great Lakes States and Tribes will use the water quality 
criteria, methodologies, policies, and procedures in the Guidance to 
establish consistent, enforceable, long-term protection for fish and 
shellfish in the Great Lakes and their tributaries, as well as for the 
people and wildlife who consume them.
    The Guidance was initially developed by the Great Lakes States, 
EPA, and other Federal agencies in open dialogue with citizens, local 
governments, and industries in the Great Lakes ecosystem. It will 
affect all types of pollutants, but will target especially the types of 
long-lasting pollutants that accumulate in the food web of large lakes.
    The Guidance consists of water quality criteria for 29 pollutants 
to protect aquatic life, wildlife, and human health, and detailed 
methodologies to develop criteria for additional pollutants; 
implementation procedures to develop more consistent, enforceable water 
quality-based effluent limits in discharge permits, as well as total 
maximum daily loads of pollutants that can be allowed to reach the 
Lakes and their tributaries from all sources; and antidegradation 
policies and procedures.
    Under the Clean Water Act, the States of Illinois, Indiana, 
Michigan, Minnesota, New York, Ohio, Pennsylvania, and Wisconsin must 
adopt provisions into their water quality standards and NPDES permit 
programs within two years (by March 23, 1997) that are consistent with 
the Guidance, or EPA will promulgate the provisions for them. The 
Guidance for the Great Lakes System will help establish consistent, 
enforceable, long-term protection from all types of pollutants, but 
will place short-term emphasis on the types of long-lasting pollutants 
that accumulate in the food web and pose a threat to the Great Lakes 
System. The Guidance includes minimum water quality criteria, 
antidegradation policies, and implementation procedures that provide a 
coordinated ecosystem approach for addressing existing and possible 
pollutant problems and improves consistency in water quality standards 
and permitting procedures in the Great Lakes System. In addition, the 
Guidance provisions help establish consistent goals or minimum 
requirements for Remedial Action Plans (RAPs) and Lakewide Management 
Plans (LaMPs) that are critical to the success of international multi-
media efforts to protect and restore the Great Lakes ecosystem.

EFFECTIVE DATE: April 24, 1995.

ADDRESSES: The public docket for this rulemaking, including applicable 
Federal Register documents, public comments in response to these 
documents, the Final Water Quality Guidance for the Great Lakes System, 
Response to Comments Document, other major supporting documents, and 
the index to the docket are available for inspection and copying at 
U.S. EPA Region 5, 77 West Jackson Blvd., Chicago, IL 60604 by 
appointment only. Appointments may be made by calling Wendy Schumacher 
(telephone 312-886-0142).
    Information concerning the Great Lakes Initiative (GLI) 
Clearinghouse is available from Ken Fenner, Water Quality Branch Chief, 
(WQS-16J), U.S. EPA Region 5, 77 W. Jackson Blvd., Chicago, IL 60604 
(312-353-2079).
    Copies of the Information Collection Request for the Guidance are 
available by writing or calling Sandy Farmer, Information Policy 
Branch, EPA, 401 M St., S.W. (Mail Code 2136), Washington, DC 20460 
(202-260-2740).
    Selected documents supporting the Guidance are also available for 
viewing by the public at locations listed in section XI of the 
preamble.
    Selected documents supporting the Guidance are available by mail 
upon request for a fee. Selected documents are also available in 
electronic format at no incremental cost to users of the Internet. See 
section XI of the preamble for additional information.

FOR FURTHER INFORMATION CONTACT: Kenneth A. Fenner, Water Quality 
Branch Chief (WQS-16J), U.S. EPA Region 5, 77 W. Jackson Blvd., 
Chicago, IL 60604 (312-353-2079).

SUPPLEMENTARY INFORMATION

Preamble Outline

I. Introduction
II. Background
III. Purpose of the Guidence
    A. Use the Best Available Science to Protect Human Health, 
Aquatic Life, and Wildlife
    B. Recognize the Unique Nature of the Great Lakes Basin 
Ecosystem
    C. Promote Consistency in Standards and Implementation 
Procedures While Allowing Appropriate Flexibility to States and 
Tribes
    D. Establish Equitable Strategies to Control Pollution Sources
    E. Promote Pollution Prevention Practices
    F. Provide Accurate Assessment of Costs and Benefits
IV. Sumarry of the Final Guidance
    A. Water Quality Criteria and Methodologies
    1. Protection of Aquatic Life
    2. Protection of Human Health
    3. Protection of Wildlife
    4. Bioaccumulation Methodology
    B. Implementation Procedures
    1. Site-Specific Modifications
    2. Variances from Water Quality Standards for Point Sources
    3. TMDLs and Mixing Zones
    4. Additivity
    5. Determining the Need for WQBELs (Reasonable Potential)
    6. Intake Pollutants
    7. WET
    8. Loading Limits
    9. Levels of Quantification
    10. Compliance Schedules
    C. Antidegradation Provisions
    D. Regulatory Requirements
V. Costs, Cost-Effectiveness and Benefits
    A. Costs
    B. Cost-Effectiveness
    C. Benefits
VI. Regulatory Flexibility Act
VII. Enhancing the Intergovernmental Partnership Under Executive 
Order 12875
VIII. Paperwork Reduction Act
IX. Endangered Species Act
X. Judicail Review of Provisions not Amended
XI. Supporting Documents

I. Introduction

    Section 118(c)(2) of the Clean Water Act (CWA) (Pub. L. 92-500 as 
amended by the Great Lakes Critical Programs Act of 1990 (CPA), Pub. L. 
101-596, November 16, 1990) required EPA to publish proposed and final 
water quality guidance on minimum water quality standards, 
antidegradation policies, and implementation procedures for the Great 
Lakes System. In response to these requirements, EPA published the 
Proposed Water Quality Guidance for the Great Lakes System (proposed 
Guidance) in the Federal Register on April 16, 1993 (58 FR 20802). EPA 
also published four subsequent documents in the Federal Register 
identifying corrections and requesting comments on additional related 
materials (April 16, 1993, 58 FR 21046; August 9, 1993, 58 FR 42266; 
September 13, 1993, 58 FR 47845; and August 30, 1994, 59 FR 44678). EPA 
received over 26,500 pages of comments, data, and information from over 
6,000 commenters in response to [[Page 15367]] these documents and from 
meetings with members of the public.
    After reviewing and analyzing the information in the proposal and 
these comments, EPA has developed the Final Water Quality Guidance for 
the Great Lakes System (final Guidance), published in this document and 
codified in 40 CFR part 132, which includes six appendixes of detailed 
methodologies, policies, and procedures. This preamble describes the 
background and purpose of the final Guidance, and briefly summarizes 
the major provisions. Detailed discussion of EPA's reasons for issuing 
the final Guidance, analysis of comments and issues, description of 
specific changes made to the proposed Guidance, and further description 
of the final Guidance, are provided in ``Final Water Quality Guidance 
for the Great Lakes System: Supplementary Information Document'' (SID), 
(EPA, 1995, 820-B-95-001) and in additional technical and supporting 
documents which are available in the docket for this rulemaking. Copies 
of the SID and other supporting documents are also available from EPA 
in electronic format, or in printed form for a fee upon request; see 
section XI of this preamble.

II. Background

    The Great Lakes are one of the outstanding natural resources of the 
world. They have played a vital role in the history and development of 
the United States and Canada, and have physical, chemical, and 
biological characteristics that make them a unique ecosystem. The Great 
Lakes themselves--Lakes Superior, Huron, Michigan, Erie and Ontario and 
their connecting channels--plus all of the streams, rivers, lakes and 
other bodies of water that are within the drainage basin of the Lakes 
collectively comprise the Great Lakes System.
    The System spans over 750 miles across eight States--New York, 
Pennsylvania, Ohio, Michigan, Indiana, Illinois, Wisconsin and 
Minnesota--and the Province of Ontario. The Lakes contain approximately 
18 percent of the world's and 95 percent of the United States' fresh 
surface water supply. The Great Lakes are a source of drinking water 
and energy, and are used for recreational, transportation, agricultural 
and industrial purposes by the more than 46 million Americans and 
Canadians who inhabit the Great Lakes region, including 29 Native 
American tribes. Over 1,000 industries and millions of jobs are 
dependent upon water from the Great Lakes. The Great Lakes System also 
supports hundreds of species of aquatic life, wildlife and plants along 
more than 4,500 miles of coastline which boast six National Parks and 
Lakeshores, six National Forests, seven National Wildlife Refuges, and 
hundreds of State parks, forests and sanctuaries.
    Because of their unique features, the Great Lakes are viewed as 
important to the residents of the region, and to the Nation as a whole. 
The natural resources of the region have contributed to the development 
of its economy. The Lakes' natural beauty and aquatic resources form 
the basis for heavy recreational activity. The Great Lakes Basin 
Ecosystem--the interacting components of air, land, water and living 
organisms, including humans, that live within the Great Lakes drainage 
basin--is a remarkably diverse and unique ecosystem important in the 
global ecology.
    In the past few decades, the presence of environmental contaminants 
in the Great Lakes has been of significant concern. In spite of the 
fact that the Great Lakes contain 5,500 cubic miles of water that cover 
a total surface area of 94,000 square miles, they have proved to be 
sensitive to the effects of pollutants that accumulate in them. The 
internal responses and processes that operate in the Great Lakes 
because of their depth and long hydraulic residence times cause 
pollutants to recycle between biota, sediments and the water column.
    The first major basin-wide environmental problem in the Great Lakes 
emerged in the late 1960s, when increased nutrients had dramatically 
stimulated the growth of green plants and algae, reduced dissolved 
oxygen levels, and accelerated the process of eutrophication. As oxygen 
levels continued to drop, certain species of insects and fish were 
displaced from affected areas of the Great Lakes Basin Ecosystem. 
Environmental managers determined that a lakewide approach was 
necessary to adequately control accelerated eutrophication. From the 
late 1960s through the late 1970s, United States and Canadian 
regulatory agencies agreed on measures to limit the loadings of 
phosphorus, including effluent limits on all major municipal sewage 
treatment facilities, limitations on the phosphorus content in 
household detergents, and reductions in nonpoint source runoff 
loadings. As a result of all of these efforts, open lake phosphorus 
concentrations have declined, and phosphorus loadings from municipal 
sewage treatment facilities have been reduced by an estimated 80 to 90 
percent. These reductions have resulted in dramatic improvements in 
nearshore water quality and measurable improvements in open lake 
conditions.
    More recently, scientists and public leaders have reached a general 
consensus that the presence of environmentally persistent, 
bioaccumulative contaminants is a serious environmental threat to the 
Great Lakes Basin Ecosystem. Beginning in 1963, adverse environmental 
impacts in the form of poor reproductive success and high levels of the 
pesticide DDT were observed in herring gulls in Lake Michigan. Through 
ongoing research, scientists have detected 362 contaminants in the 
Great Lakes System. Of these, approximately one third have 
toxicological data showing that they can have acute or chronic toxic 
effects on aquatic life, wildlife and/or human health. Chemicals that 
have been found to bioaccumulate at levels of concern in the Great 
Lakes include, but are not limited to, polychlorinated biphenyls 
(PCBs), mercury, DDT, dioxin, chlordane, and mirex. The main route of 
exposure to these chemicals for humans is through the consumption of 
Great Lakes fish.
    Potential adverse human health effects by these pollutants 
resulting from the consumption of fish include both the increased risk 
of cancer and the potential for systemic or noncancer risks such as 
kidney damage. EPA has calculated health risks to populations in the 
Great Lakes basin from consumption of contaminated fish based on 
exposure to eight bioaccumulative pollutants: chlordane, DDT, dieldrin, 
hexachlorobenzene, mercury, PCBs, 2,3,7,8-TCDD, and toxaphene. These 
chemicals were chosen based on their potential to cause adverse human 
health effects (i.e., cancer or disease) and the availability of 
information on fish tissue contaminant concentrations from the Great 
Lakes.
    Based on these data, EPA estimates that the lifetime cancer risks 
for Native Americans in the Great Lakes System due to ingestion of 
contaminated fish at current concentrations range from 1.8  x  
10-\3\ (Lake Superior) (1.8 in one thousand) to 3.7  x  
10-\2\ (Lake Michigan) (3.7 in 100). Estimated risks to low income 
minority sport anglers range from 2.5  x  10-\3\ (2.5 in one 
thousand) (Lake Superior) to 1.2  x  10-\2\ (1.2 in 100) (Lake 
Michigan). Estimated risks for other sport anglers range from 9.7  x  
10-\4\ (9.7 in ten thousand) (Lake Superior) to 4.5  x  
10-\3\ (4.5 in one thousand) (Lake Michigan). (See section I.B.2.a 
of the SID.) In comparison, EPA has long maintained that 1  x  
10-\4\ (one in ten thousand) to 1  x  10-\6\ (one in 1 
million) is an appropriate range of risk to protect human health. 
[[Page 15368]] 
    EPA also estimates a high potential risk of systemic (noncancer) 
injury to populations in the Great Lakes basin due to ingestion of fish 
contaminated with these pollutants at current concentrations. The 
systemic adverse health effects associated with the assessed 
contaminants are described in section I.B of the SID.
    Although the Great Lakes States and EPA have moved forward to deal 
with these problems, control of persistent, bioaccumulative pollutants 
proved to be more complex and difficult than dealing with nutrients. As 
a result, inconsistencies began to be apparent in the ways various 
States developed and implemented controls for the pollutants. By the 
mid-1980s, such inconsistencies became of increasing concern to EPA and 
State environmental managers.
    EPA began the Great Lakes Water Quality Initiative (``Initiative'') 
in cooperation with the Great Lakes States to establish a consistent 
level of environmental protection for the Great Lakes ecosystem, 
particularly in the area of State water quality standards and the 
National Pollutant Discharge Elimination System (NPDES) programs. In 
the spring of 1989, the Council of Great Lakes Governors unanimously 
agreed to participate in the Initiative with EPA, because the 
Initiative supported the principles and goals of the Great Lakes Toxic 
Substances Control Agreement (Governors' Agreement). Signed in 1986 by 
the Governors of all eight Great Lakes States, the Governors' Agreement 
affirmed the Governors' intention to manage and protect the resources 
of the Great Lakes basin through the joint pursuit of unified and 
cooperative principles, policies and programs enacted and adhered to by 
each Great Lakes State.
    The Initiative provided a forum for a regional dialogue to 
establish minimum requirements that would reduce disparities between 
State water quality controls in the Great Lakes basin. The scope of the 
Initiative included development of proposed Great Lakes water quality 
guidance--Great Lakes-specific water quality criteria and methodologies 
to protect aquatic life, wildlife and human health, procedures to 
implement water quality criteria, and an antidegradation policy.
    Three committees were formed to oversee the Initiative. A Steering 
Committee (composed of directors of water programs from the Great Lakes 
States' environmental agencies and EPA's National and Regional Offices) 
discussed policy, scientific, and technical issues, directed the work 
of the Technical Work Group and ratified final proposals. The Technical 
Work Group (consisting of technical staff from the Great Lakes States' 
environmental agencies, EPA, the U.S. Fish and Wildlife Service, and 
the National Park Service) prepared proposals on elements of the 
Guidance for consideration by the Steering Committee. The Public 
Participation Group (consisting of representatives from environmental 
groups, municipalities, industry and academia) observed the 
deliberations of the other two committees, advised them of the public's 
concerns, and kept its various constituencies apprised of ongoing 
activities and issues. These three groups were collectively known as 
the Initiative Committees. From the start, one goal of the Initiative 
Committees was to develop the Guidance elements in an open public 
forum, drawing upon the extensive expertise and interest of individuals 
and groups within the Great Lakes community.
    The Initiative efforts were well underway when Congress amended 
section 118 of the CWA in 1990 through the CPA. The general purpose of 
these amendments was to improve the effectiveness of EPA's existing 
programs in the Great Lakes by identifying key treaty provisions agreed 
to by the United States and Canada in the Great Lakes Water Quality 
Agreement (GLWQA), imposing statutory deadlines for the implementation 
of these key activities, and increasing Federal resources for program 
operations in the Great Lakes System.
    Section 118(c)(2) requires EPA to publish proposed and final water 
quality guidance for the Great Lakes System. This Guidance must conform 
with the objectives and provisions of the GLWQA (a binational agreement 
establishing common water quality objectives for the Great Lakes) and 
be no less restrictive than provisions of the CWA and National water 
quality criteria and guidance. The Guidance must specify minimum 
requirements for the waters in the Great Lakes System in three areas: 
(1) water quality standards (including numerical limits on pollutants 
in ambient Great Lakes waters to protect human health, aquatic life and 
wildlife); (2) antidegradation policies; and (3) implementation 
procedures.
    The Great Lakes States must adopt water quality standards, 
antidegradation policies and implementation procedures for waters 
within the Great Lakes System which are consistent with the final 
Guidance within two years of EPA's publication. In the absence of such 
action, EPA is required to promulgate any necessary requirements within 
that two-year period. In addition, when an Indian Tribe is authorized 
to administer the NPDES or water quality standards program in the Great 
Lakes basin, it will also need to adopt provisions consistent with the 
final Guidance into their water programs.
    On December 6, 1991, the Initiative Steering Committee unanimously 
recommended that EPA publish the draft Guidance ratified by that group 
in the Federal Register for public review and comment. The agreement 
that the draft Great Lakes Guidance was ready for public notice did not 
represent an endorsement by every State of all of the specific 
proposals. Rather, all parties agreed on the importance of proceeding 
to publish the draft Great Lakes Guidance in order to further solicit 
public comment. State Steering Committee members indicated their intent 
to develop and submit specific comments on the proposed Guidance during 
the public comment period. EPA worked to convert the agreements reached 
in principle by the Steering Committee into a formal package suitable 
for publication in the Federal Register as proposed Guidance. EPA 
generally used the draft proposal ratified by the Steering Committee as 
the basis for preparing the Federal Register proposal package. 
Modifications were necessary, however, to reflect statutory and 
regulatory requirements and EPA policy considerations, to propose 
procedures for State and Tribal adoption of the final Guidance, to 
provide suitable discussion of various alternative options, and to 
accommodate necessary format changes. Where modifications were made, 
the preamble to the proposal described both the modification and the 
original Steering Committee-approved guidelines, and invited public 
comment on both. All elements approved by the Steering Committee were 
either incorporated in the proposed rule or discussed in the preamble 
to the proposal.

III. Purpose of the Guidance

    The final Guidance represents a milestone in the 30 years of effort 
described above on the part of the Great Lakes stakeholders to define 
and apply innovative, comprehensive environmental programs in 
protecting and restoring the Great Lakes. In particular, this 
publication of the final Guidance culminates six years of intensive, 
cooperative effort that included participation by the eight Great Lakes 
States, the environmental community, academia, industry, municipalities 
and EPA Regional and National offices. [[Page 15369]] 
    The final Guidance will help establish consistent, enforceable, 
long-term protection with respect to all types of pollutants, but will 
place short-term emphasis on the types of long-lasting pollutants that 
accumulate in the food web and pose a threat to the Great Lakes System. 
The final Guidance will establish goals and minimum requirements that 
will further the next phase of Great Lakes programs, including the 
Great Lakes Toxic Reduction Effort's integrated, multi-media ecosystem 
approach.
    EPA and State development of the Guidance--from drafting through 
proposal and now final publication--was guided by several general 
principles that are discussed below.

A. Use the Best Available Science to Protect Human Health, Aquatic 
Life, and Wildlife

    EPA and the Initiative Committees have been committed throughout 
the Initiative to using the best available science to develop programs 
to protect the Great Lakes System. In the 1986 Governors' Agreement, 
the Governors of the Great Lakes States recognized that the problem of 
persistent toxic substances was the foremost environmental issue 
confronting the Great Lakes. They also recognized that the regulation 
of toxic contaminants was scientifically complex because the pollutants 
are numerous, their pathways into the Lakes are varied, and their 
effects on the environment, aquatic life and human health are not 
completely understood. Based on the importance of the Great Lakes Basin 
Ecosystem and the documented adverse effects from toxic contamination, 
however, the Governors directed their environmental administrators to 
jointly develop an agreement and procedure for coordinating the control 
of toxic releases and achieving greater uniformity of regulations 
governing such releases within the Great Lakes basin.
    As discussed further above, the Initiative was subsequently created 
to begin work on these goals. EPA and the Great Lakes States, with 
input from interested parties in the basin, began collecting and 
analyzing data, comparing regulatory requirements and technical 
guidance in their various jurisdictions, and drafting specific 
methodologies and procedures to control the discharge of toxic 
contaminants. The provisions of the final Guidance were based in large 
part on these prior efforts of the Initiative Committees, and 
incorporate the best available science to protect human health, 
wildlife and aquatic life in the Great Lakes System. For example, the 
final Guidance includes new criteria and a methodology developed by the 
Initiative Committees to specifically protect wildlife; incorporates 
recent data on the bioavailability of metals into the aquatic life 
criteria and methodologies; incorporates Great Lakes-specific data on 
fish consumption rates and fish lipid contents into the human health 
criteria; and provides a methodology to determine the bioaccumulation 
properties of individual pollutants. Additionally, EPA understands that 
the science of risk assessment is rapidly improving. Therefore, in 
order to ensure that the scientific basis for the criteria 
methodologies is always current and peer reviewed, EPA will review the 
methodologies and revise them as appropriate every three years.

B. Recognize the Unique Nature of the Great Lakes Basin Ecosystem

    The final Guidance also reflects the unique nature of the Great 
Lakes Basin Ecosystem by establishing special provisions for chemicals 
of concern. EPA and the Great Lakes States believe it is reasonable and 
appropriate to establish special provisions for the chemicals of most 
concern because of the physical, chemical and biological 
characteristics of the Great Lakes System, and the documented 
environmental harm to the ecosystem from the past and continuing 
presence of these types of pollutants. The Initiative Committees 
devoted considerable effort to identifying the chemicals of most 
concern to the Great Lakes System--persistent, bioaccumulative 
pollutants termed ``bioaccumulative chemicals of concern (BCCs)''--and 
developing the most appropriate criteria, methodologies, policies, and 
procedures to address them. The special provisions for BCCs, initially 
developed by the Initiative Committees and incorporated into the final 
Guidance, include antidegradation procedures, to ensure that future 
problems are minimized; general phase-out and elimination of mixing 
zones for BCCs, except in limited circumstances, to reduce their 
overall loadings to the Lakes; more extensive data generation 
requirements to ensure that they are not under-regulated for lack of 
data; and development of water quality criteria that will protect 
wildlife that feed on aquatic prey.
    The final Guidance is designed not only to begin to address 
existing problems, but also to prevent emerging and potential problems 
posed by additional chemicals in the future which may damage the 
overall health of the Great Lakes. The experience with such pollutants 
as DDT and PCBs indicates that it takes many decades to overcome the 
damage to the ecosystem caused by even short-term discharges, and that 
prevention would have been dramatically less costly than clean-up. 
Issuance of the final Guidance alone will not solve the existing long-
term problems in the Great Lakes System from these contaminants. Full 
implementation of provisions consistent with the final Guidance will, 
however, provide a coordinated ecosystem approach for addressing 
possible pollutant problems before they produce adverse and long-
lasting basin-wide impacts, rather than waiting to see what the future 
impacts of the pollutants might be before acting to control them. The 
comprehensive approach used in the development of the final Guidance 
provides regulatory authorities with both remedial and preventive ways 
of gauging the actions and potential effects of chemical stressors upon 
the Great Lakes Basin Ecosystem. The methodologies, policies and 
procedures contained in the final Guidance provide mechanisms for 
appropriately addressing both pollutants that have been or may in the 
future be documented as chemicals of concern.

C. Promote Consistency in Standards and Implementation Procedures While 
Allowing Appropriate Flexibility to States and Tribes

    Promoting consistency in standards and implementation procedures 
while providing for appropriate State flexibility was the third 
principle in State and EPA development of the final Guidance. The 
underlying rationale for the Governors' Agreement, the Initiative, and 
the requirements set forth in the CPA was a recognition of the need to 
promote consistency through adoption of minimum water quality 
standards, antidegradation policies, and implementation procedures by 
Great Lakes States and Tribes to protect human health, aquatic life and 
wildlife. Although provisions in the CWA provide for the adoption of 
and periodic revisions to State water quality criteria, such provisions 
do not necessarily ensure that water quality criteria of adjoining 
States are consistent within a shared water body. For example, ambient 
water quality criteria in place in six of the eight Great Lakes States 
to protect aquatic life from acute effects range from 1.79 g/L 
to 15.0 g/L for cadmium, and from 0.21 g/L to 1.33 
g/L for dieldrin. Other examples of variations in acute 
aquatic life criteria include nickel, which ranges from 290.30 
g/L to 852.669 g/L; lindane, [[Page 15370]] with a 
range of no criteria in place to 1.32 g/L; and mercury, 
ranging from 0.5 g/L to 2.4 g/L. Similar ranges and 
disparities exist for chronic aquatic life criteria, and for water 
quality criteria to protect human health.
    Disparities also exist among State procedures to translate water 
quality criteria into individual discharge permits. Wide variations 
exist, for example, in procedures for the granting of mixing zones, 
interpretation of background levels of pollutants, consideration of 
pollutants present in intake waters, controls for pollutants present in 
concentrations below the level of detection, and determination of 
appropriate levels for pollutants discharged in mixtures with other 
pollutants. Additionally, when addressing the accumulation of chemicals 
by fish that will be consumed by humans and wildlife, some States 
consider accumulation through multiple steps in the food chain 
(bioaccumulation) while others consider only the single step of 
concentration from the water column (bioconcentration). Further 
disparities exist in different translator methodologies in deriving 
numeric values for implementing narrative water quality criteria; 
different assumptions when calculating total maximum daily loads 
(TMDLs) and wasteload allocations (WLAs), including different 
assumptions about background concentrations, mixing zones, receiving 
water flows, or environmental fate; and different practices in deciding 
what pollutants need to be regulated in a discharge, what effect 
detection limits have on compliance determinations, and how to develop 
whole effluent toxicity limitations.
    These inconsistencies in State standards and implementation 
procedures have resulted in the disparate regulation of point source 
discharges. In the Governors' Agreement, the Governors recognized that 
the water resources of the basin transcend political boundaries and 
committed to taking steps to manage the Great Lakes as an integrated 
ecosystem. The Great Lakes States, as participants in the Initiative 
Committees, recommended provisions, based on their extensive experience 
in administering State water programs and knowledge of the significant 
differences in these programs within the basin, that were ultimately 
included in the proposed Guidance. The final Guidance incorporates the 
work begun by the Initiative Committees to identify these disparities 
and improve consistency in water quality standards and permit 
procedures in the Great Lakes System.
    Although improved consistency in State water programs is a primary 
goal of the final Guidance, it is also necessary to provide appropriate 
flexibility to States and Tribes in the development and implementation 
of water programs. In overseeing States' implementation of the CWA, EPA 
has found that reasonable flexibility is not only necessary to 
accommodate site-specific situations and unforeseen circumstances, but 
is also appropriate to enable innovation and progress as new approaches 
and information become available. Many commenters, including the Great 
Lakes States, urged EPA to evaluate the appropriate level of 
flexibility provided to States and Tribes in the proposed Guidance 
provisions. EPA reviewed all sections of the proposed Guidance and all 
comments received to determine the appropriate level of flexibility 
needed to address these concerns while still providing a minimum level 
of consistency between the State and Tribal programs. Based on this 
review, the final Guidance provides flexibility for State and Tribal 
adoption and implementation of provisions consistent with the final 
Guidance in many areas, including the following:

--Antidegradation: Great Lakes States and Tribes may develop their own 
approaches for implementing the prohibition against deliberate actions 
of dischargers that increase the mass loading of BCCs without an 
approved antidegradation demonstration. Furthermore, States and Tribes 
have flexibility in adopting antidegradation provisions regarding non-
BCCs.
--TMDLs: Great Lakes States and Tribes may use assessment and 
remediation plans for the purposes of appendix F to part 132 if the 
State or Tribe certifies that the assessment and remediation plan meets 
certain TMDL-related provisions in the final Guidance and public 
participation requirements applicable to TMDLs, and if EPA approves 
such plan. Thus, States have the flexibility in many cases to use 
LAMPs, RAPs and State Water Quality Management Plans in lieu of TMDLs.
--Intake Credits: Great Lakes States and Tribes may consider the 
presence of intake water pollutants in establishing water quality-based 
effluent limits (WQBELs) in accordance with procedure 5 of appendix F.
--Site-Specific Modifications: Great Lakes States and Tribes may adopt 
either more or less stringent modifications to human health, wildlife, 
and aquatic life criteria and bioaccumulation factors (BAFs) based on 
site-specific circumstances specified in procedure 1 of appendix F. All 
criteria, however, must be sufficient not to cause jeopardy to 
threatened or endangered species listed or proposed to be listed under 
the Federal Endangered Species Act.
--Variances: Great Lakes States and Tribes may grant variances from 
water quality standards based on the factors identified in procedure 2 
of appendix F.
--Compliance Schedules: Great Lakes States and Tribes may allow 
existing Great Lakes dischargers additional time to comply with permit 
limits in order to collect data to derive new or revised Tier I 
criteria and Tier II values in accordance with procedure 9 of appendix 
F.
--Mixing Zones: Great Lakes States and Tribes may authorize mixing 
zones for existing discharges of BCCs after the 10-year phase-out 
period in accordance with procedure 3.B of appendix F, if the 
permitting authority determines, among other things, that the 
discharger has reduced its discharge of the BCC for which a mixing zone 
is sought to the maximum extent possible. Water conservation efforts 
that result in overall reductions of BCCs are also allowed even if they 
result in higher effluent concentrations.
--Scientific Defensibility Exclusion: Great Lakes States and Tribes may 
apply alternate procedures consistent with Federal, State, and Tribal 
requirements upon demonstration that a provision in the final Guidance 
would not be scientifically defensible if applied to a particular 
pollutant in one or more sites. This provision is in Sec. 132.4(h) of 
the final Guidance.
--Reduced Detail: In many instances, EPA has revised the proposed 
Guidance to reduce the amount of detail in the provisions without 
sacrificing the objectives of the provisions. Examples of such 
revisions include simplification of procedures for developing TMDLs in 
procedure 3 of appendix F, and simplification of procedures for 
determining reasonable potential to exceed water quality standards in 
procedure 5.B of appendix F.
--Other Provisions: Flexibility is also present in provisions for the 
exercise of best professional judgment by the Great Lakes States and 
Tribes when implementing many individual provisions in the final 
Guidance including: determining the appropriate uncertainty factors in 
the human health and wildlife criteria methodologies; selection of data 
sets for establishing water quality criteria; identifying reasonable 
and prudent [[Page 15371]] measures in antidegradation provisions; and 
specifying appropriate margins of safety when developing TMDLs. In all 
cases, of course, State and Tribal provisions would need to be 
scientifically defensible and consistent with all applicable regulatory 
requirements.

D. Establish Equitable Strategies to Control Pollution Sources

    Many commenters argued that the proposed Guidance unfairly focused 
on point source discharges. They asserted that nonpoint sources or 
diffuse sources of pollution, such as air emissions, are responsible 
for most of the loadings of some pollutants of concern in the Great 
Lakes, that increased regulation of point sources will be inequitable 
and expensive, and that the final Guidance will not result in any 
environmental improvement given the large, continuing contribution of 
toxic pollutants by nonpoint sources.
    EPA recognizes that regulation of point source discharges alone 
cannot address all existing or future environmental problems from toxic 
pollutants in the Great Lakes. In addition to discharges from point 
sources, toxic pollutants are also contributed to the Great Lakes from 
industrial and municipal emissions to the air, resuspension of 
pollutants from contaminated sediments, urban and agricultural runoff, 
hazardous waste and Superfund sites, and spills. Restoration and 
maintenance of a healthy ecosystem will require significant efforts in 
all of these areas. EPA, Canada and the Great Lakes States and Tribes 
are currently implementing or developing many voluntary and regulatory 
programs to address these and other nonpoint sources of environmental 
contaminants in the Great Lakes.
    Additionally, EPA intends to use the scientific data developed in 
the final Guidance and new or revised water quality criteria 
subsequently adopted by Great Lakes States and Tribes in evaluating and 
determining appropriate levels of control in other environmental 
programs. For example, EPA's future biennial reports under section 
112(m) of the Clean Air Act will consider the extent to which air 
discharges cause or contribute to exceedances of water quality criteria 
in assessing whether additional air emission standards or control 
measures are necessary to prevent serious adverse effects. Similarly, 
once provisions consistent with the final Guidance are adopted by the 
Great Lakes States or Tribes, they will serve as applicable or relevant 
and appropriate requirements (ARARs) for on-site responses under the 
Comprehensive Environmental Response, Compensation and Liability Act 
(CERCLA). EPA will also consider the data and criteria developed for 
the final Guidance, including the information on BCCs, in developing or 
evaluating LaMPs and RAPs under section 118 of the CWA and Article VI, 
Annex 2 of the GLWQA; determination of corrective action requirements 
under sections 3004(u), 3008(h), or 7003 of the Solid Waste Disposal 
Act; new or existing chemical reviews under the Toxic Substances 
Control Act (TSCA); pesticide reviews under the Federal Insecticide, 
Fungicide and Rodenticide Act (FIFRA); and reporting requirements for 
toxic releases under the Emergency Planning and Community Right-to-Know 
Act (EPCRA).
    The final Guidance also includes provisions to address the 
contribution of pollutants by nonpoint sources. First, the water 
quality criteria to protect human health, wildlife and aquatic life, 
and the antidegradation provisions apply to the waters in the Great 
Lakes System regardless of whether discharges to the water are from 
point or nonpoint sources. Accordingly, any regulatory programs for 
nonpoint sources that require compliance with water quality standards 
would also be subject to the criteria and antidegradation provisions of 
the final Guidance once they are adopted into State or Tribal 
standards.
    Second, several elements of the final Guidance would, after State, 
Tribal or Federal promulgation, require or allow permitting authorities 
to consider the presence of pollutants in ambient waters--including 
pollutants from nonpoint source dischargers--in establishing WQBELs for 
point sources. For example, permit authorities may consider the 
presence of other point or nonpoint source discharges when evaluating 
whether to grant a variance from water quality criteria. Additionally, 
the provisions for TMDLs address nonpoint sources by specifying that 
the loading capacity of a receiving water that does not meet water 
quality standards for a particular pollutant be allocated, where 
appropriate, among nonpoint as well as point sources of the pollutant, 
including, at a minimum, a margin of safety to account for technical 
uncertainties in establishing the TMDL. The development of TMDLs is the 
preferred mechanism for addressing equitable division of the loading 
capacities of these nonattained waters. Because TMDLs have not been 
completed for most nonattained waters, however, the final Guidance 
promotes the development of TMDLs through a phased approach, where 
appropriate, and provides for short-term regulatory relief to point 
source dischargers in the absence of TMDLs through intake credits, 
variances, and other water quality permitting procedures.
    EPA received numerous comments on the problem posed in controlling 
mercury in particular. Many commenters stated that since the primary 
source of mercury is now atmospheric deposition, point sources 
contribute only a minor portion of the total loading of mercury to the 
Great Lakes System and further restriction of point source discharges 
would have no apparent effect in improving water quality. Although EPA 
believes that there is sufficient flexibility in the Guidance to handle 
the unique problems posed by mercury (e.g., water quality variances, 
phased TMDLs, intake credits), EPA is committed to developing a mercury 
permitting strategy to provide a holistic, comprehensive approach for 
dealing with this pollutant. EPA will publish this strategy no later 
than two years following publication of this Guidance.
    There are also many ongoing voluntary and regulatory activities 
that address nonpoint sources of toxic pollutants to the Great Lakes 
System, including activities taken under the Clean Air Act Amendments 
of 1990 (CAAA), the CWA, and State regulatory and voluntary programs. 
Some of these activities are summarized in the preamble to the proposed 
Guidance (58 FR 20826-32) and section I.D of the SID.
    In addition to the many ongoing activities, EPA and the Great Lakes 
States, Tribes, and other federal agencies are pursuing a multi-media 
program to prevent and to further reduce toxic loadings from all 
sources of pollution to the Great Lakes System, with an emphasis on 
nonpoint sources. This second phase of the Great Lakes Water Quality 
Initiative, called the Great Lakes Toxic Reduction Effort (GLTRE), will 
build on the open, participative public dialogue established during the 
development of the final Guidance. Through the GLTRE, the Federal, 
State, and Tribal agencies intend to coordinate and enhance the 
effectiveness of ongoing actions and existing tools to prevent and 
reduce nonpoint source and wet-weather point source contributions of 
toxic pollutants in the Great Lakes System. A special emphasis will be 
placed on BCCs identified in the final Guidance.
    A partial list of ongoing actions that are being or could be 
focused on BCCs includes: implementation of the CAAA to reduce 
atmospheric deposition of toxics; Resource Conservation and Recovery 
Act and CERCLA remedial actions to reduce loadings of toxics from 
[[Page 15372]] hazardous waste sites; increased focus (through the 
GLTRE) on toxic pollutants emanating from combined sewer overflows and 
stormwater outfalls; application in the Great Lakes basin of the 
National Contaminated Sediment Management Strategy; implementation of 
spill prevention planning practices to minimize this potential source 
of loadings to the Great Lakes; improved reporting of toxic pollutants 
under the Toxic Release Inventory; public education on the dangers of 
mercury and other BCCs; pesticide registration and re-registration 
processes; development of a ``mass balance'' model for fate and 
transport of pollutants in the Great Lakes; and, development of a 
``virtual elimination strategy.'' These programs will prevent and 
further reduce mass loadings of pollutants and facilitate equitable 
division of the costs of any necessary control measures between point 
and nonpoint sources.
    In addition to the GLTRE, which is basin-wide in scope, a primary 
vehicle for coordinating Federal and State programs at the local level 
for meeting water quality standards and restoring beneficial uses for 
the open waters of the Great Lakes are LaMPS. LaMPs will define media 
specific program actions to further reduce loadings of toxic 
substances, assess whether these programs will ensure restoration and 
attainment of water quality standards and designated beneficial uses, 
and recommend any media-specific program enhancements as necessary. 
Additionally, LaMPs will be periodically updated and revised to assess 
progress in implementing media-specific programs, assess the reductions 
in toxic loadings to the Great Lakes System through these programs, 
incorporate advances in the understanding of the System based on new 
data and information, and recommend specific adjustments to media 
programs as appropriate.

E. Promote Pollution Prevention Practices

    The final Guidance also promotes pollution prevention practices 
consistent with EPA's National Pollution Prevention Strategy and the 
Pollution Prevention Action Plan for the Great Lakes. The Pollution 
Prevention Act of 1990 declares as National policy that reducing the 
sources of pollution is the preferred approach to environmental 
protection. When source reductions are not possible, however, 
recycling, treating and properly disposing of pollutants in an 
environmentally safe manner complete the hierarchy of management 
options designed to prevent pollution from entering the environment.
    Consistent with the goals of the Pollution Prevention Act, EPA 
developed the Great Lakes Pollution Prevention Action Plan (April, 
1991). The Great Lakes Pollution Prevention Action Plan highlights how 
EPA, in partnership with the States, will incorporate pollution 
prevention into actions designed to reduce the use and release of toxic 
substances in the Great Lakes basin.
    The final Guidance builds upon these two components of the Great 
Lakes program by promoting the development of pollution prevention 
analysis and activities in the level of detection, mixing zone, and 
antidegradation sections of the final Guidance. Also, the decision to 
provide special provisions for BCCs implements EPA's commitment to 
pollution prevention by reducing the discharge of these pollutants in 
the future. This preventive step not only makes good environmental 
management sense, but is appropriate based on the documented adverse 
effects that the past and present discharge of these pollutants has 
produced in the Great Lakes basin.

F. Provide Accurate Assessment of Costs and Benefits

    In developing the final Guidance, EPA identified and carefully 
evaluated the anticipated costs and benefits from implementation of the 
major provisions. EPA received many comments on the draft cost and 
benefit studies conducted as part of the proposed Regulatory Impact 
Analysis (RIA) required by Executive Order 12291, and its successor, 
Executive Order 12866. Based upon consideration of those comments and 
further analysis, EPA has revised the RIA. The results of this analysis 
are summarized in section V of this preamble.

IV. Summary of the Final Guidance

    The final Guidance will establish minimum water quality standards, 
antidegradation policies, and implementation procedures for the waters 
of the Great Lakes System in the States of Illinois, Indiana, Michigan, 
Minnesota, New York, Pennsylvania, Ohio and Wisconsin, including waters 
within the jurisdiction of Indian Tribes. Specifically, the final 
Guidance specifies numeric criteria for selected pollutants to protect 
aquatic life, wildlife and human health within the Great Lakes System 
and provides methodologies to derive numeric criteria for additional 
pollutants discharged to these waters. The final Guidance also contains 
minimum procedures to translate the proposed ambient water quality 
criteria into enforceable controls on discharges of pollutants, and a 
final antidegradation policy.
    The provisions of the final Guidance are not enforceable 
requirements until adopted by States or Tribes, or promulgated by EPA 
for a particular State or Tribe. The Great Lakes States and Tribes must 
adopt water quality standards, antidegradation policies, and 
implementation procedures for waters within the Great Lakes System 
consistent with the (as protective as) final Guidance or be subject to 
EPA promulgation. Great Lakes Tribes include any Tribe within the Great 
Lakes basin for which EPA has approved water quality standards under 
section 303 or has authorized to administer a NPDES program under 
section 402 of the CWA. No Indian Tribe has been authorized to 
administer these water programs in the Great Lakes basin as of this 
time. If a Great Lakes State fails to adopt provisions consistent with 
the final Guidance within two years of this publication in the Federal 
Register (that is, by March 23, 1997), EPA will publish a final rule at 
the end of that time period identifying the provisions of the final 
Guidance that will apply to waters and discharges within that 
jurisdiction. Additionally, when an Indian Tribe is authorized to 
administer the NPDES or water quality standards program in the Great 
Lakes basin, it will also need to adopt provisions consistent with the 
final Guidance into their water programs.
    The following sections provide a brief summary of the provisions of 
the final Guidance. A more complete discussion of the final Guidance, 
including EPA's analysis of major comments, issues, and a description 
of specific changes made to the proposed Guidance, are contained in the 
SID.
    The parenthetical note at the beginning of each section provides 
references to the primary provisions in the final Guidance being 
discussed in the section, and to discussions in the SID. The final 
Guidance is codified as 40 CFR 132, including appendixes A through F. 
Note that appendix F consists of procedures 1 through 9. For ease of 
reference, sections in appendix F may be referred to by appending the 
section designation to the procedure number. For example, section A.1 
of procedure 1 may be referred to as procedure 1.A.1 of appendix F. 
[[Page 15373]] 

A. Water Quality Criteria and Methodologies

1. Protection of Aquatic Life
    (Secs. 132.3(a), 132.3(b), 132.4(a)(2); Tables 1 and 2 to part 132; 
appendix A to part 132; section III, SID)
    The final Guidance contains numeric criteria to protect aquatic 
life for 15 pollutants, and a two-tiered methodology to derive criteria 
(Tier I) or values (Tier II) for additional pollutants discharged to 
the Great Lakes System. Aquatic life criteria are derived to establish 
ambient concentrations for pollutants, which, if not exceeded in the 
Great Lakes System, will protect fish, invertebrates, and other aquatic 
life from adverse effects due to that pollutant. The final Guidance 
includes both acute and chronic criteria to protect aquatic life from 
acute and chronic exposures to pollutants.
    Tier I aquatic life criteria for each chemical are based on 
laboratory toxicity data for a variety of aquatic species (e.g., fish 
and invertebrates) which are representative of species in the 
freshwater aquatic environment as a whole. The Guidance also includes a 
Tier II methodology to be used in the absence of the full set of data 
needed to meet Tier I data requirements. For pollutants for which Tier 
I criteria have not been adopted into State or Tribal water quality 
standards, States must use methodologies consistent with either the 
Tier I or Tier II methodologies, depending on the data available, in 
conjunction with whole effluent toxicity requirements in the final 
Guidance (see section IV.B.5 of this preamble), to implement their 
existing narrative water quality criteria that prohibit toxic 
pollutants in toxic amounts in all waters. The Great Lakes States and 
Tribes are not required to use the Tier II methodology to adopt numeric 
criteria into their water quality standards.
    Use of the two-tiered final Guidance methodologies in these 
situations will enable regulatory authorities to translate narrative 
criteria to derive TMDLs and individual NPDES permit limits on a more 
uniform basis. EPA and the States determined that there is a need to 
regulate pollutants more consistently in the Great Lakes System when 
faced with limited numbers of criteria. Many of the Great Lakes States 
are already employing procedures similar to the approach in the final 
Guidance to implement narrative criteria. EPA determined the Tier II 
approach improves upon existing mechanisms by utilizing all available 
data.
    The two-tiered methodology allows the application of the final 
Guidance to all pollutants, except those listed in Table 5 of part 132 
(see section IV.E of this preamble). The Tier I aquatic life 
methodology includes data requirements very similar to those used in 
current guidelines for developing National water quality criteria 
guidance under section 304(a) of the CWA. For example, both require 
that acceptable toxicity data for aquatic species in at least eight 
different families representing differing habitats and taxonomic groups 
must exist before a Tier I numeric criterion can be derived. The Tier 
II aquatic life methodology is used to derive Tier II values which can 
be calculated with fewer toxicity data than Tier I. Tier II values can, 
in certain instances, be based on toxicity data from a single taxonomic 
family, provided the data are acceptable. The Tier II methodology 
generally produces more stringent values than the Tier I methodology, 
to reflect greater uncertainty in the absence of additional toxicity 
data. As more data become available, the derived Tier II values tend to 
become less conservative. That is, they more closely approximate Tier I 
numeric criteria. EPA and the States believe it is desirable to 
continue to supplement toxicity data to ultimately derive Tier I 
numeric criteria.
    One difference from the existing National water quality criteria 
guidelines is that the final Guidance methodology for aquatic life 
deletes the provision in the National guidelines to use a Final Residue 
Value (FRV) in deriving a criterion. The FRV is intended to prevent 
concentrations of pollutants in commercially or recreationally 
important aquatic species from affecting the marketability of those 
species or affecting wildlife that consume them by preventing the 
exceedance of applicable Food and Drug Administration action levels and 
concentrations that affect wildlife. The final Guidance provides 
specific, separate methodologies to protect wildlife and human health 
(discussed below) which EPA believes will provide more accurate and 
appropriate levels of protection than the FRVs.
    For pollutants without Tier I criteria but with enough data to 
derive Tier II values for aquatic life, the proposal would have 
required permittees to meet permit limits based on both Tier II values 
and whole effluent toxicity (WET) testing. In response to comments, the 
final Guidance clarifies that States and Tribes may adopt provisions 
allowing use of indicator parameter limits consistent with 40 CFR 
122.44(d)(1)(vi)(C). When deriving limits to meet narrative criteria, 
States and Tribes have the option of using an indicator parameter 
limit, including use of a WET limit under appropriate conditions, in 
lieu of a Tier II-based limit. If use of an indicator parameter is 
allowed, the State or Tribe must ensure that the indicator parameter 
will attain the ``applicable water quality standard'' (as described in 
40 CFR 122.44(d)(1)(vi)(C). The ``applicable water quality standard'' 
in this instance would be the State's or Tribe's narrative water 
quality standard that protects aquatic life.
    Finally, the aquatic criteria for metals in the proposed Guidance 
were expressed as total recoverable concentrations. The final Guidance 
expresses the criteria for metals in dissolved form because the 
dissolved metal more closely approximates the bioavailable fraction of 
metal in the water column than does the total recoverable metal. The 
dissolved criteria are obtained by multiplying the chronic and/or acute 
criterion by appropriate conversion factors in Table 1 or 2. This is 
consistent with many comments on the issue and with the policy on 
metals detailed in ``Office of Water Policy and Technical Guidance on 
Interpretation and Implementation of Aquatic Life Metals Criteria'' 
(October 1, 1993). A document describing the methodology to convert 
total recoverable metals criteria to dissolved metals criteria was 
published in the Federal Register on August 30, 1994 (59 FR 44678). If 
a State or Tribe fails to adopt approvable aquatic life criteria for 
metals, EPA will promulgate criteria expressed as dissolved 
concentrations.
    EPA Region 5, in cooperation with EPA Regions 2 and 3 and 
Headquarters offices, and the Great Lakes States and Tribes, will 
establish a Great Lakes Initiative (GLI) Clearinghouse to assist States 
and Tribes in developing numeric Tier I water quality criteria for 
aquatic life, human health and wildlife and Tier II water quality 
values for aquatic life and human health. As additional toxicological 
data and exposure data become available or additional Tier I numeric 
criteria and Tier II values are calculated by EPA, States, or Tribes, 
Region 5 will ensure that this information is disseminated to the Great 
Lakes States and Tribes. EPA believes operation of the GLI 
Clearinghouse will help ensure consistency during implementation of the 
final Guidance.
2. Protection of Human Health
    (Secs. 132.3(c), 132.4(a)(4); Table 3 to part 132; appendix C to 
part 132; section V of the SID)
    The final Guidance contains numeric human health criteria for 18 
pollutants, and includes Tier I and Tier II methodologies to derive 
cancer and [[Page 15374]] non-cancer human health criteria for 
additional pollutants. The proposed Guidance contained numeric criteria 
for 20 pollutants, but two pollutants were deleted because they do not 
meet the more restrictive minimum data requirements for BAFs used in 
the final Guidance.
    Tier I human health criteria are derived to establish ambient 
concentrations of chemicals which, if not exceeded in the Great Lakes 
System, will protect individuals from adverse health impacts from that 
chemical due to consumption of aquatic organisms and water, including 
incidental water consumption related to recreational activities in the 
Great Lakes System. For each chemical, chronic criteria are derived to 
reflect long-term consumption of food and water from the Great Lakes 
System. Tier II values are intended to provide a conservative, interim 
level of protection in the establishment of a permit limit, and are 
distinguished from the Tier I approach by the amount and quality of 
data used for derivation.
    The final Guidance differs from current National water quality 
criteria guidelines when calculating the assumed human exposure through 
consumption of aquatic organisms. The final Guidance uses BAFs 
predicted from biota-sediment accumulation factors (BSAFs) in addition 
to field-measured BAFs, and uses a food chain multiplier (FCM) to 
account for biomagnification when using measured or predicted 
bioconcentration factors (BCFs). BAFs are discussed further in section 
IV.A.4. of this preamble.
    Human health water quality criteria for carcinogens are typically 
expressed in concentrations associated with a plausible upper bound of 
increased risk of developing cancer. In practice, the level of cancer 
risk generally accepted by EPA and the States typically ranges between 
10-\4\ (one in one thousand) and 10-\6\ (one in one million). 
In contrast, as discussed in section II above, the cancer risk from 
ingestion of contaminated fish at current concentrations in the Great 
Lakes System are as high as 1.2  x  10-\2\ (1.2 in 100). The 
proposed and final Guidance establishes 10-\5\ (one in one hundred 
thousand) as the risk level used for deriving criteria and values for 
individual carcinogens. This is within the range historically used in 
EPA actions, and approved for State actions, designed to protect human 
health. The majority of the Great Lakes States use 10-\5\ as a 
baseline risk level in establishing their water quality standards.
    The methodology is designed to protect humans who drink water or 
consume fish from the Great Lakes System. The portion of the 
methodology addressing fish consumption includes a factor describing 
how much fish humans consume per day. The final Guidance includes a 
Great Lakes-specific fish consumption rate of 15 grams per day, based 
upon several fish consumption surveys from the Great Lakes, including a 
recent study by West et al. that was discussed in a Federal Register 
document on August 30, 1994 (59 FR 44678). This rate differs from the 
6.5 grams per day rate which is used in the National water quality 
criteria guidelines as a National average consumption value. The 15 
grams per day represents the mean consumption rate of regional fish 
caught and consumed by the Great Lakes sport fishing population.
    Commenters argued that a 15 gram per day assumption in the 
methodology would not adequately protect populations that consume 
greater than this amount (e.g., low-income minority anglers and Native 
Americans), and that such an approach therefore would be inconsistent 
with Executive Order 12898 regarding environmental justice (February 
16, 1994, 59 FR 7629). EPA believes that the human health criteria 
methodology, including the fish consumption rate, will provide adequate 
health protection for the public, including more highly exposed sub-
populations. In carrying out regulatory actions under a variety of 
statutory authorities, including the CWA, EPA has generally viewed an 
upper bound incremental cancer risk in the range of 10-4 to 
10-6 as adequately protective of public health. As discussed 
above, the human health criteria methodology is based on a risk level 
of 10-5. Therefore, if fish are contaminated at the level 
permitted by criteria derived under the final Guidance, individuals 
eating up to 10 times (i.e., 150 grams per day) the assumed fish 
consumption rate would still be protected at the 10-4 risk level. 
Available data indicate that, even among low-income minorities who as a 
group consume more fish than the population on average, the 
overwhelming majority (approximately 95 percent) consume less than 150 
grams per day. The final Guidance requires, moreover, that States and 
Tribes modify the human health criteria on a site-specific basis to 
provide additional protection appropriate for highly exposed sub-
populations. Thus, where a State or Tribe finds that a population of 
high-end consumers would not be adequately protected by criteria 
derived using the 15 gram per day assumption (e.g., where the risk was 
greater than 10-4), the State or Tribe would be required to modify 
the criteria to provide appropriate additional protection. The final 
Guidance also requires States and Tribes to adopt provisions to protect 
human health from the potential adverse effects of mixtures of 
pollutants in effluents, specifically including mixtures of 
carcinogens. Understood in the larger context of the human health 
methodology and the final Guidance as a whole, therefore, EPA believes 
that the 15 gram per day fish consumption rate provides adequate health 
protection for the public, including highly exposed populations, and 
that the final Guidance is therefore consistent with Executive Order 
12898.
    In developing bioaccumulation factors, the proposed Guidance used a 
5.0 percent lipid value for fish consumed by humans, based on Great 
Lakes-specific data. The current National methodology uses a 3.0 
percent lipid value. The final Guidance uses a 3.10 percent lipid value 
for trophic level 4 fish and 1.82 for trophic level 3 fish. These 
percent lipid values are based on an analysis of the West et al. study 
cited above and data from State fish contaminant monitoring programs.
    The final Guidance contains specific technical guidelines 
concerning the range of uncertainty factors that may be applied by the 
State and Tribal agencies on the basis of their best professional 
judgment. The final Guidance places a cap of 30,000 on the combined 
product of uncertainty factors that may be applied in the derivation of 
non-cancer Tier II values and a combined uncertainty factor of 10,000 
for Tier I criteria. The likely maximum combined uncertainty factor for 
Tier I criteria in most cases is 3,000. The SID discusses further the 
use of the uncertainty factors in the derivation of human health 
criteria and values.
    The proposed Guidance used an 80 percent relative source 
contribution (RSC) from surface water pathways for BCCs, and a 100 
percent RSC for all other pollutants, in deriving noncancer criteria. 
The RSC concept is applied in the National drinking water regulations 
and is intended to account, at least in part, for exposures from other 
sources for those bioaccumulative pollutants for which surface water 
pathways are likely to be major contributors to human exposure. The 
final Guidance uses the more protective 80 percent RSC for all 
pollutants in deriving noncancer criteria. This change was made because 
of concern that for non-BCCs as well as [[Page 15375]] BCCs, there may 
be other sources of exposures for noncarcinogens.
3. Protection of Wildlife
    (Secs. 132.3(d), 132.4(a)(5); Table 4 to part 132; appendix D to 
part 132; section VI of the SID)
    The final Guidance contains numeric criteria to protect wildlife 
for four pollutants and a methodology to derive Tier I criteria for 
additional BCCs. Wildlife criteria are derived to establish ambient 
concentrations of chemicals which, if not exceeded, will protect 
mammals and birds from adverse impacts from that chemical due to 
consumption of food and/or water from the Great Lakes System.
    These are EPA's first water quality criteria specifically for the 
protection of wildlife. The methodology is based largely on the 
noncancer human health paradigm. It focuses, however, on endpoints 
related to reproduction and population survival rather than the 
survival of individual members of a species. The methodology 
incorporates pollutant-specific effect data for a variety of mammals 
and birds and species-specific exposure parameters for two mammals and 
three birds representative of mammals and birds resident in the Great 
Lakes basin which are likely to experience significant exposure to 
bioaccumulative contaminants through the aquatic food web.
    In the proposal, EPA included a two-tiered approach similar to that 
for aquatic life and human health. In response to comments, the final 
Guidance requires States and Tribes to adopt provisions consistent with 
only the Tier I wildlife methodology, and only to apply this 
methodology for BCCs (see section IV.A.4 below). The TSD provides 
discretionary guidelines for the use of Tier I and Tier II 
methodologies for other pollutants. The wildlife methodology was 
limited to the BCCs because these are the chemicals of greatest concern 
to the higher trophic level wildlife species feeding from the aquatic 
food web in the Great Lakes basin. This decision is consistent with 
comments made by the EPA Science Advisory Board (SAB) who agreed that 
the initial focus for wildlife criteria development should be on 
persistent, bioaccumulative organic contaminants (USEPA, 1994, EPA-SAB-
EPEC-ADV-94-001).
    Numerous commenters were concerned that the mercury criterion for 
wildlife was not scientifically appropriate. After review of all 
comments and a reevaluation of all the data, the mercury criterion for 
wildlife has been increased from 180 pg/L to 1300 pg/L. EPA believes 
the 1300 pg/L is protective of wildlife in the Great Lakes System.
    In developing bioaccumulation factors, the proposed Guidance used a 
7.9 percent lipid value for fish consumed by wildlife. The final 
Guidance uses a 10.31 percent lipid value for trophic level 4 fish and 
6.46 for trophic level 3 fish. These percent lipid values are based on 
the actual prey species consumed by the representative wildlife species 
specified in the methodology, and are used to estimate the BAFs for the 
trophic levels which those species consume. The percent lipid is based 
on the preferential consumption patterns of wildlife and cross-
referenced with fish weight and size and appropriate percent lipid. 
This approach is a more accurate reflection of the lipid content of the 
fish consumed by wildlife species than the approach used in the 
proposal.
4. Bioaccumulation Methodology
(Sec. 132.4(a)(3); appendix B to part 132; section IV of the SID)

    The proposed Guidance incorporated BAFs in the derivation of 
criteria and values to protect human health and wildlife. 
Bioaccumulation refers to the uptake and retention of a substance by an 
aquatic organism from its surrounding medium and from food. For certain 
chemicals, uptake through the aquatic food chain is the most important 
route of exposure for wildlife and humans. The wildlife criteria and 
the human health criteria and values incorporate appropriate BAFs in 
order to more accurately account for the total exposure to a chemical. 
Current EPA guidelines for the derivation of human health water quality 
criteria use BCFs, which measure only uptake from water, when field-
measured BAFs are not available. EPA believes, however, that the BAF is 
a better predictor of the concentration of a chemical within fish 
tissues in the Great Lakes System because it includes consideration of 
the uptake of contaminants from all routes of exposure.
    The proposed Guidance included a hierarchy of three methods for 
deriving BAFs for non-polar organic chemicals: field-measured BAFs; 
predicted BAFs derived by multiplying a laboratory-measured BCF by a 
food-chain multiplier; and BAFs predicted by multiplying a BCF 
calculated from the log Kow by a food-chain multiplier. For 
inorganic chemicals, the proposal would have required either a field-
measured BAF or laboratory-measured BCF. On August 30, 1994, EPA 
published a document in the Federal Register (59 FR 44678) requesting 
comments on revising the hierarchy of methods for deriving BAFs for 
organic chemicals, and issues pertaining to the model used to assist in 
predicting BAFs when a field-measured BAF is not available. Based on 
the comments received, the final Guidance modifies the proposed 
hierarchy by adding a predicted BAF based on a BSAF as the second 
method in the hierarchy. BSAFs may be used for predicting BAFs from 
concentrations of chemicals in surface sediments. In addition, the 
final Guidance uses a model to assist in predicting BAFs that includes 
both benthic and pelagic food chains thereby incorporating exposures of 
organisms to chemicals from both the sediment and the water column. The 
model used in the proposal only included the pelagic food chain, and 
therefore, did not account for exposure to aquatic organisms from 
sediment.
    The proposed Guidance used the total concentration of a chemical in 
the ambient water when deriving BAFs for organic chemicals. In the 
preamble to the proposed Guidance and in the Federal Register document 
cited above, EPA requested comments on deriving BAFs in terms of the 
freely dissolved concentration of the chemical in the ambient water. 
Based on comments received from the proposal and the document, the 
final Guidance uses the freely dissolved concentration of a chemical 
instead of the total concentration in the derivation of BAFs for 
organic chemicals. Use of the freely dissolved concentration will 
improve the accuracy of extrapolations between water bodies.
    Finally, as discussed in section II of this preamble, 
bioaccumulation of persistent pollutants is a serious environmental 
threat to the Great Lakes Basin Ecosystem. Because of these concerns, 
the proposed Guidance would have required that pollutants with human 
health BAFs greater than 1000 receive increased attention and more 
stringent controls within the Great Lakes System. These pollutants are 
termed BCCs. EPA identified 28 BCCs in the proposed Guidance. The 
additional controls for BCCs are specified in certain of the 
implementation procedures and the antidegradation procedures, and are 
discussed further in the SID. The final Guidance continues to include 
increased attention on and more stringent controls for BCCs within the 
Great Lakes System. The final Guidance identifies 22 BCCs that are 
targeted for special controls instead of the 28 in the proposed 
Guidance. Six BCCs were deleted from the proposed list because of 
concern that the methods used to estimate the BAFs may not 
[[Page 15376]] account for the metabolism or degradation of the 
pollutants in the environment. States and Tribes may identify more BCCs 
as additional BAF data become available. The final Guidance designates 
as BCCs only those chemicals with human health BAFs greater than 1000 
that were derived from either a field-measured BAF or a predicted BAF 
based on a field-measured BSAF (for non-metals) or from a field-
measured BAF or a laboratory-measured BCF (for metals). Field-measured 
BAFs and BSAFs, unlike BAFs based only on laboratory analyses or 
calculations, account for the effects of metabolism.

B. Implementation Procedures

(Secs. 132.4(a)(7), 132.4(e); appendix F to part 132; section VIII of 
the SID)

    This section of the preamble discusses nine specific procedures 
contained in the final Guidance for implementing water quality 
standards and developing NPDES permits to attain the standards.
1. Site-Specific Modifications
(Procedure 1 of appendix F to part 132; section VIII.A of the SID)

    The proposed Guidance would have allowed States and Tribes to adopt 
site-specific modifications to water quality criteria and values under 
certain circumstances. States and Tribes could modify aquatic life 
criteria to be either more stringent or less stringent when local water 
quality characteristics altered the biological availability or toxicity 
of a pollutant, or where local species' sensitivities differed from 
tested species. Less stringent modifications to chronic aquatic life 
criteria could also be made to reflect local physical and hydrological 
conditions. States and Tribes could also modify BAFs and human health 
and wildlife criteria to be more stringent, but not less stringent than 
the final Guidance.
    The final Guidance retains most of the above provisions, but in 
addition allows less stringent modifications to acute aquatic life 
criteria and values to reflect local physical and hydrological 
conditions, less stringent modifications to BAFs in developing human 
health and wildlife criteria, and the use of fish consumption rates 
lower than 15 grams per day if justified. The final Guidance also 
specifies that site-specific modifications must be made to prevent 
water quality that would cause jeopardy to endangered or threatened 
species that are listed or proposed under the ESA, and prohibits any 
less-stringent site-specific modifications that would cause such 
jeopardy. Other issues related to the ESA are discussed in section IX 
of this preamble.
2. Variances from Water Quality Standards for Point Sources
(Procedure 2 of appendix F to part 132; section VIII.B of the SID)

    The final Guidance allows Great Lakes States and Tribes to adopt 
variances from water quality standards, applicable to individual 
existing Great Lakes dischargers for up to five years, where specified 
conditions exist. For example, a variance may be granted when 
compliance with a criterion would result in substantial and widespread 
social and economic impacts or where certain stream conditions prevent 
the attainment of the criterion. No significant changes were made in 
this section from the proposed Guidance.
3. TMDLs and Mixing Zones
(Procedure 3 of appendix F to part 132; section VIII.C of the SID)

    Section 303(d) of the CWA and implementing regulations at 40 CFR 
130.7 require the establishment of TMDLs for waters not attaining water 
quality standards after implementation of existing or planned pollution 
controls. The TMDL quantifies the maximum allowable loading of a 
pollutant to a water body and allocates the loading capacity to 
contributing point and nonpoint sources (including natural background) 
such that water quality standards for that pollutant will be attained. 
A TMDL must incorporate a margin of safety (MOS) that accounts for 
uncertainty about the relationship between pollutant loads and water 
quality. TMDLs may involve single point sources or multiple sources 
(e.g., point sources and nonpoint sources) and may be established for 
geographic areas that range in size from large watersheds to relatively 
small water body segments.
    The proposal attempted to develop a single, consistent approach for 
developing TMDLs to be used by all States and Tribes in the Great Lakes 
System. Current practice in the eight Great Lakes States includes 
distinct technical procedures and program approaches that differ in 
scale, emphasis, scope and level of detail. Two options for TMDL 
development were proposed. One, Option A, focused on first evaluating 
the basin as a whole and then conducting individual site-by-site 
adjustments as necessary to ensure attainment of water quality 
standards at each location in the basin. The other, Option B, focused 
on evaluating limits needed for individual point sources with 
supplemental emphasis on basin-wide considerations as necessary. Both 
approaches are consistent with the CWA, but result in different 
methodologies for TMDL development.
    Both options proposed that within 10 years of the effective date of 
the final Guidance (i.e., two five-year NPDES permit terms), mixing 
zones would be prohibited for BCCs for existing point source discharges 
to the Great Lakes System. Further, both proposed that mixing zones be 
denied for new point source discharges of BCCs as of the effective date 
of the final Guidance. Both options also specified procedures for 
determining background levels of pollutants present in ambient waters. 
In addition, the proposal would have tightened the relationship between 
TMDL development and NPDES permit issuance by providing that TMDLs be 
established for each pollutant causing an impairment in a water body 
prior to the issuance or reissuance of any NPDES permits for that 
pollutant.
    The final Guidance merges both Options A and B into one single set 
of minimum regulatory requirements for TMDL development. In general, 
the final TMDL procedures are less detailed than the proposal, and 
offer more flexibility for States and Tribes in establishing TMDLs. The 
final TMDL procedures contain elements from both Options A and B that 
were deemed critical for a minimum level of consistency among the Great 
Lakes States and Tribes. These critical elements include: mixing zone 
specifications, design flows, and procedures for determining background 
concentrations.
    The final Guidance also includes a prohibition on mixing zones for 
BCCs after 12 years in most circumstances. Maintaining these 
restrictions on the availability of mixing zones is consistent with 
both the Steering Committee's policy views and the bi-national GLWQA 
goal of virtual elimination of persistent, bioaccumulative toxics. 
Because of the unique nature of the Great Lakes ecosystem, documented 
ecological impacts, and the need for consistency, EPA believes that the 
general prohibition on mixing zones for BCCs is reasonable and 
appropriate. However, a new exception is allowed if a facility with an 
existing BCC discharge can demonstrate that it is reducing that 
discharge to the maximum extent feasible (considering technical and 
economic factors) but cannot meet WQBELs for that discharge without a 
mixing zone. EPA, in conjunction with stakeholders within the Great 
Lakes Basin, will develop guidance for use by [[Page 15377]] States and 
Tribes in exercising the exception provision with special focus on the 
technical and economic feasibility criteria. This guidance will also 
consider the notice, public hearing, monitoring and pollution 
prevention demonstration elements of the exception criteria.
    The final Guidance also retains many of the proposed provisions for 
calculating background concentrations used in TMDLs and WLAs 
established in the absence of TMDLs. The procedure addressing data 
points below the level of detection, however, has been modified so that 
it no longer specifies the use of default values (i.e., half of the 
level of detection).
    The final TMDL procedures do not require that TMDLs be established 
for point sources prior to the issuance/reissuance of NPDES permits. 
The final Guidance defers to the existing National program for 
determining when a TMDL is required. Lastly, the final Guidance allows 
assessment and remediation plans that are approved by EPA under 40 CFR 
130.6 to be used in lieu of a TMDL for purposes of appendix F as long 
as they meet the general conditions of a TMDL as outlined by procedure 
3 of appendix F, and the public participation requirements applicable 
to TMDLs.
4. Additivity
(Procedure 4 of appendix F to part 132; section VIII.D of the SID)

    EPA has traditionally developed numeric water quality criteria on a 
single pollutant basis. While some potential environmental hazards 
involve significant exposure to only a single compound, most instances 
of contamination in surface waters involve mixtures of two or more 
pollutants. The individual pollutants in such mixtures can act or 
interact in various ways which may affect the magnitude and nature of 
risks or effects on human health, aquatic life and wildlife. WET tests 
are available to generally address interactive effects of mixtures on 
aquatic organisms. EPA's 1986 ``Guidelines for the Health Risk 
Assessment of Chemical Mixtures'' set forth principles and procedures 
for human health risk assessment of chemical mixtures. There are 
currently no technical guidelines on how to assess effects on wildlife 
from chemical mixtures.
    The preamble for the proposed Guidance discussed several possible 
approaches to address additive effects from multiple pollutants. 
Proposed regulatory language was provided for two specific options, 
each with separate provisions related to aquatic life, wildlife and 
human health. One approach was developed by the Initiative Committees, 
modified to delete the application of toxicity equivalency factors 
(TEFs) for PCBs to wildlife. The other approach was developed by EPA. 
Neither approach addressed the possible toxicologic interactions 
between pollutants in a mixture (e.g., synergism or antagonism) because 
of the limited data available on these interactive effects. In the 
absence of contrary data, both approaches recommended that the risk to 
human health from individual carcinogens in a mixture be considered 
additive, and that a 10-5 risk level be adopted as a cap for the 
cancer risk associated with mixtures. Both approaches also proposed 
using TEFs to assess the risk to humans and wildlife from certain 
chemical classes. The TEF approach converts the concentration of 
individual components in a mixture of chemicals to an ``equivalent'' 
concentration expressed in terms of a reference chemical. Both 
approaches used the 17 TEFs for dioxins and furans identified in the 
1989 EPA document, ``Estimating Risks Associated with Exposures to 
Mixtures of Chlorinated Dibenzo-p-Dioxins and -Dibenzofurans,'' and the 
1989 update.
    The final Guidance includes a general requirement for States and 
Tribes to adopt an additivity provision consistent with procedure 4 of 
appendix F to protect human health from the potential additive adverse 
effects from both the noncarcinogenic and carcinogenic components of 
chemical mixtures in effluents. The final Guidance also requires the 
use of the 17 TEFs included in the proposed Guidance to protect human 
health from the potential additive adverse effects in effluents.
5. Determining the Need for WQBELs (Reasonable Potential)
(Procedure 5 of appendix F to part 132; section VIII.E of the SID)

    EPA's existing regulations require NPDES permits to include WQBELs 
to control all pollutants or pollutant parameters which the permitting 
authority determines are or may be discharged at a level which will 
cause, have the reasonable potential to cause or contribute to an 
excursion of any applicable water quality standard. If the permitting 
authority determines that a discharge has the reasonable potential to 
cause or contribute to an excursion of an applicable numeric water 
quality criterion, it must include a WQBEL for the individual pollutant 
in the permit. In the absence of an adopted numeric water quality 
criterion for an individual pollutant, the permitting authority must 
derive appropriate WQBELs from the State or Tribal narrative water 
quality criterion by either calculating a numeric criterion for the 
pollutant; applying EPA's water quality criteria developed under 
section 304(a) of the CWA, supplemented with other information where 
necessary; or establishing effluent limitations on an indicator 
pollutant. See 40 CFR 122.44(d)(1).
    The final Guidance implements these National requirements by 
specifying procedures for determining whether a discharge has the 
reasonable potential to cause or contribute to an exceedance of Tier I 
criteria or Tier II values based on facility-specific effluent data. 
The final Guidance also specifies procedures for determining whether 
permitting authorities must generate or require permittees to generate 
data sufficient to calculate Tier II values when specified pollutants 
of concern in the Great Lakes System are known or suspected of being 
discharged, but neither Tier I criteria nor Tier II values have been 
derived due to a lack of toxicological data. EPA believes that the data 
necessary to calculate Tier II values for aquatic life, wildlife and 
human health currently exists for most of the specified pollutants of 
concern.
    The final Guidance maintains all the basic requirements from the 
proposed procedure. Some minor changes are that the procedure no longer 
includes a special provision for effluent dominated streams, and the 
procedure allows a broader range of statistical approaches to be used 
when evaluating effluent data, which provides added simplicity and 
flexibility to States and Tribes.
    Another change from the proposal is the relationship in the final 
Guidance between the reasonable potential and TMDL procedures. Numerous 
commenters pointed out that the proposed Guidance indicated that TMDLs 
would be required for any water receiving effluent from a discharger 
found to exhibit reasonable potential. Given the fact that there are 
many waterbodies in the Great Lakes basin for which TMDLs have not been 
developed, and the obvious need for permitting to proceed in the 
interim until TMDLs are completed, the final Guidance provides that the 
permitting authority can establish waste load allocations and WQBELs in 
the absence of a TMDL or an assessment and remediation plan developed 
and approved in accordance with procedure 3.A of appendix F. A more 
detailed discussion of the assessment and remediation plan and its 
relationship to a TMDL can be found in section VIII.C.2 of the SID. 
Procedures for establishing such WLAs are therefore addressed in the 
final Guidance. [[Page 15378]] 
6. Intake Pollutants
(Procedures 5.D and 5.E of appendix F to part 132; section VIII.E of 
the SID)

    The proposed Guidance allowed a permitting authority to determine 
that the return of an identified intake water pollutant to the same 
body of water under specified circumstances does not cause, have the 
reasonable potential to cause, or contribute to an excursion above 
water quality standards, and therefore, that a WQBEL would not be 
required for that pollutant. Under the proposal, this ``pass through'' 
of intake water pollutants would be allowed if the facility returns the 
intake water containing the pollutant of concern to the same waterbody; 
does not contribute additional mass of pollutant; does not increase the 
concentration of the intake water pollutant; and does not discharge at 
a time or location, or alter the pollutant in a manner which would 
cause adverse impacts to occur that would not occur if the pollutant 
were left in-stream.
    EPA received numerous comments on the proposal. Some commenters 
argued that the proposed provision was too narrow because relief would 
not be available if the facility added any amount of the pollutant to 
the discharge, even where the facility was not contributing any 
additional mass or concentration to the waterbody than was contained in 
the intake water. After consideration of public comments, EPA decided 
to expand the intake pollutant provisions to include not only a 
reasonable potential procedure like the one contained in the proposal, 
but also a provision that allows the permitting authority to take into 
account the presence of pollutants in intake water in deriving WQBELs. 
Specifically, the final Guidance authorizes the permitting authority to 
establish limits based on a principle of ``no net addition'' (i.e., the 
limit would allow the mass and concentration of the pollutant in the 
discharge up to the mass and concentration of the pollutant in the 
intake water). This provision would be available where the facility's 
discharge is to the same body of water as the intake water, and could 
be applied for up to 12 years after publication of the final Guidance. 
After that time, if a TMDL or comparable plan that meets the 
requirements of procedure 3 of appendix F has not been completed, the 
facility's WQBEL must be established in accordance with the 
``baseline'' provisions in procedure 5.F.2 of appendix F. This time 
limit provides a period of relief for dischargers that are not causing 
increased impacts on the waterbody by virtue of their discharge that 
would not have occurred had the pollutant remained in-stream, while 
maintaining the incentive for development of a comprehensive assessment 
and remediation plan for achieving attainment of water quality 
standards, which EPA believes is a critical element of the final 
Guidance for addressing pollutants for which a large contributor to 
non-attainment is nonpoint source pollution.
    The final Guidance allows States and Tribes to address intake 
pollutants in a manner consistent with assessment and remediation plans 
that have been developed through mechanisms other than TMDLs in order 
to provide flexibility where such plans comprehensively address the 
point and non-point sources of non-attainment in a waterbody and the 
means for attaining compliance with standards.
    EPA believes that 12 years provides sufficient time for States to 
develop and complete the water quality assessments that would serve as 
the basis for establishing effluent limits (including ``no net 
addition'' limits, where appropriate) under procedure 3.A of appendix 
F. However, EPA also recognizes that unforeseen events could delay 
State completion of these assessments, and therefore will, at 7 years 
following promulgation, in consultation with the States, evaluate the 
progress of the assessments. If this evaluation shows that completion 
of the assessments may not be accomplished by the 12 year date, EPA 
will revisit these provisions, and consider proposing extensions if 
appropriate.
    Under the final Guidance, the permitting authority can permit the 
discharge of intake pollutants to a different body of water that is in 
non-attainment provided limitations require the discharge to meet a 
WQBEL for the pollutant equal to the pollutant's water quality 
criterion. Because inter-waterbody transfers of pollutants introduce 
pollutants to the receiving water that would not be present in that 
waterbody in the absence of the facility's discharge, EPA does not 
believe that relief for such pollutants comparable to the ``no net 
addition'' approach would be appropriate. However, to address the 
concern raised by commenters about facilities with multiple sources of 
intake water, the permitting authority may use a flow-weighted 
combination of these approaches when the facility has co-mingled 
sources of intake water from the same and different bodies of water.
    EPA maintains that the preferred approach to deal with non-
attainment waters, particularly when multiple sources contribute a 
pollutant for which the receiving water exceeds the applicable 
criterion, is development of a TMDL or comparable assessment and 
remediation plan. The above ``no net addition'' permitting approach 
provides additional flexibility in situations where a TMDL or 
comparable plan has not yet been developed. Other existing relief 
mechanisms include variances to water quality standards, removal of 
non-existing uses, and site-specific criteria.
7. WET
(Procedure 6 of appendix F to part 132; section VIII.F of the SID)

    Existing EPA regulations define WET as ``the aggregate toxic effect 
of an effluent measured directly by a toxicity test.'' These 
regulations require WET limits to be included in permits in most 
circumstances in which the WET of a discharge has the reasonable 
potential to cause or contribute to an in-stream excursion above either 
a State's numeric criteria for toxicity or narrative criteria for water 
quality (40 CFR 122.2, 122.44(d)(1)). The regulations allow States and 
Tribes the flexibility to control for WET with either numeric or 
narrative criteria. Current technical guidelines recommend that no 
discharge should exceed 0.3 acute toxic units (TUa = 100/LC50) at the 
edge of an acute mixing zone and 1.0 chronic toxic units (TUc = 100/
NOEC, the No Observed Effect Concentration) at the edge of a chronic 
mixing zone.
    The proposed Guidance would have continued to allow States and 
Tribes the flexibility to choose to control WET with either numeric or 
narrative criteria, but specified that no discharge could exceed 1.0 
TUa at the point of discharge (i.e., no acute mixing zones) and 
1.0 TUc at the edge of a chronic mixing zone (with some 
exceptions). In addition, the proposal contained minimum requirements 
for appropriate test methods to measure WET and for permit conditions, 
and procedures for determining whether or not limits for WET are 
necessary.
    The final Guidance differs principally from the proposal in 
requiring States and Tribes to adopt 0.3 TUa and 1.0 TUc 
either as numeric criteria or as an equivalent numeric interpretation 
of narrative criteria. The final Guidance also allows the use of acute 
mixing zones for the application of the acute criterion. This approach 
will promote consistency among States and Tribes in controlling WET, 
while still permitting considerable flexibility regarding 
implementation measures, consistent with current National policies and 
guidelines. [[Page 15379]] 
8. Loading Limits
(Procedure 9 of appendix F to part 132; section VIII.G of the SID)

    The final Guidance provides that WQBELs be expressed in terms of 
both concentration and mass loading rate, except for those pollutants 
that cannot appropriately be expressed in terms of mass. These 
provisions clarify the application of existing Federal regulations at 
40 CFR 122.45(f), and are consistent with current EPA guidance which 
requires the inclusion of any limits determined necessary based on best 
professional judgment to meet water quality standards, including, where 
appropriate, mass loading rate limits. They are also consistent with 
the antidegradation policy for the Great Lakes System in appendix E of 
the final Guidance.
9. Levels of Quantification
(Procedure 8 of appendix F to part 132; section VIII.H of the SID)

    Many of the pollutants of concern in the Great Lakes System cause 
unacceptable toxic effects at very low concentrations. This results in 
instances where WQBELs are below levels of reliable quantification. 
When this occurs, the permitting authority may not be able to determine 
whether the pollutant concentration is above or below the WQBEL. The 
final Guidance requires adoption of pollutant minimization programs 
(PMPs) for such permits to increase the likelihood that the 
concentration of the pollutant is as close to the effluent limit as 
possible. The PMP is an ongoing, iterative process that requires, among 
other things, internal wastestream monitoring and submission of status 
reports. The use of PMPs for facilities with pollutants below the level 
of quantification is consistent with existing EPA guidance.
    Unlike the proposal, however, the final Guidance eliminates 
additional minimum requirements for BCCs. For example, the final 
Guidance recommends but does not require bio-uptake studies that had 
been proposed to assess impacts to the receiving water and evaluate the 
effectiveness of the PMP.
10. Compliance Schedules
(Procedure 9 of appendix F to part 132; section VIII.I of the SID)

    The final Guidance includes a procedure that allows Great Lakes 
States and Tribes to include schedules of compliance in permits for 
existing Great Lakes dischargers for effluent limitations based on new 
water quality criteria and certain other requirements. Generally, 
compliance schedules may provide for up to five years to comply with 
the effluent limitation in question and may, in specified cases, allow 
the compliance schedule to go beyond the term of the permit. Existing 
Great Lakes dischargers are those whose construction commenced before 
March 23, 1997. Thus the term, existing Great Lakes discharges, covers 
expanding dischargers who were ineligible for compliance schedules 
under the proposal. The final Guidance also provides the opportunity 
for States and Tribes to allow dischargers additional time to comply 
with effluent limitations based on Tier II values while conducting 
studies to justify modifications of those limitations.

C. Antidegradation Provisions

(Sec. 132.4(a)(6); appendix E to part 132; section VII of the SID)

    EPA's existing regulations, at 40 CFR 131.6, establish an 
antidegradation policy as one of the minimum requirements of an 
acceptable water quality standards submittal. Section 131.12 describes 
the required elements of an antidegradation policy. These are: 
protection of water quality necessary to maintain existing uses, 
protection of high quality waters (those where water quality exceeds 
levels necessary to support propagation of fish, shellfish, and 
wildlife and recreation in and on the waters) and protection of water 
quality in those water bodies identified as outstanding National 
resources.
    The proposed Guidance provided detailed procedures for implementing 
antidegradation that were not part of the existing regulations. The 
detailed implementation procedures were intended to result in greater 
consistency in how antidegradation was applied throughout the Great 
Lakes System. The proposed Guidance specified, among other things, how 
high quality waters should be identified, what activities should and 
should not require review under antidegradation, and the information 
necessary to support a request to lower water quality and the 
procedures to be followed by a Tribe or State in making a decision 
whether or not to allow a lowering of water quality.
    The final Guidance maintains the overall structure of the proposed 
Guidance while allowing Tribes and States greater flexibility in how 
antidegradation is implemented. As in the proposal, the final Guidance 
is composed of an antidegradation standard, antidegradation 
implementation procedures, antidegradation demonstration and 
antidegradation decision. However, many of the detailed requirements 
found in the proposed Guidance appear in the SID accompanying the final 
Guidance as nonbinding guidelines, including provisions specific to 
non-BCCs.
    Key elements of the proposed Guidance that are retained in the 
final Guidance for BCCs include: identification of high quality waters 
on a pollutant-by-pollutant basis; requirements for States and Tribes 
to adopt an antidegradation standard consistent with the final Guidance 
for BCCs; minimum requirements for conducting an antidegradation review 
of any activity expected to result in a significant lowering of water 
quality due to BCCs, minimum requirements for notifying permitting 
authorities of increases in discharges of BCCs; and, minimum 
requirements for an antidegradation demonstration consisting of a 
pollution prevention analysis, an alternative treatment analysis and a 
showing that the significant lowering of water quality will allow for 
important social and economic development. Significant changes from the 
proposed Guidance include: encouraging, but not requiring, States and 
Tribes to adopt provisions consistent with the antidegradation standard 
and implementation procedures for non-BCCs; replacement of numeric 
existing effluent quality-based (EEQ) limits as a means of implementing 
antidegradation for BCCs with a narrative description of the types of 
activities that will trigger an antidegradation review; and greater 
flexibility in the implementation, demonstration and decision 
components. A detailed discussion of the basis for each of the changes 
is provided in Section VII the SID.

D. Regulatory Requirements

(Part 132; Tables 5 and 6 to part 132; section II of the SID)

    The Great Lakes States must adopt water quality standards, anti-
degradation policies, and implementation procedures for waters within 
the Great Lakes System which are consistent with the final Guidance 
within two years of this publication. If a Great Lakes State fails to 
adopt such standards, policies, and procedures, section 118(c)(2)(C) of 
the CWA requires EPA to promulgate them not later than the end of that 
two-year period. Additionally, when an Indian Tribe is authorized to 
administer the NPDES or water quality standards program in the Great 
Lakes basin, it will also need to adopt provisions consistent with the 
final Guidance into its water program.
    Part 132 establishes requirements and procedures to implement 
section 118(c)(2)(C). Sections 132.3 and 132.4 [[Page 15380]] require 
Great Lakes States and Tribes to adopt criteria, methodologies, 
policies, and procedures consistent with the criteria, methodologies, 
policies, and procedures contained in part 132--that is, the 
definitions in Sec. 132.2, the numeric criteria in Tables 1 through 4, 
the criteria development methodologies in appendixes A through D, the 
antidegradation policy in appendix E, and the implementation procedures 
in appendix F. Section 132.5 specifies the procedures for States and 
Tribes to make their submissions to EPA, and for EPA to approve or 
disapprove the submissions. The section specifies that in reviewing 
submissions, EPA will consider provisions of State and Tribal 
submissions to be ``consistent with'' the final Guidance if each 
provision is as protective as the corresponding provision of the final 
Guidance. If a State or Tribe fails to make a submission, or if 
provisions of the submission are not consistent with the final 
Guidance, Sec. 132.5 provides that EPA will publish a final rule in the 
Federal Register identifying the final Guidance provisions that will 
apply to discharges within the particular State or Federal Indian 
Reservation.
    Section 132.4 specifies that water quality criteria adopted by 
States and Tribes consistent with the final Guidance will apply to all 
waters of the Great Lakes System, regardless of designated uses of the 
waters in most cases, with some variations in human health criteria 
depending on whether the waters are designated for drinking water use. 
Section 132.4 also contains certain exceptions in applying the final 
Guidance methodologies and procedures. First, States and Tribes do not 
have to adopt and apply the final Guidance methodologies and procedures 
for the 14 pollutants listed in Table 5 of part 132. EPA believes that 
some or all of the methodologies and procedures are not scientifically 
appropriate for these pollutants. Second, if a State or Tribe 
demonstrates that the final Guidance methodologies or procedures are 
not scientifically defensible for a particular pollutant, the State or 
Tribe may use alternate methodologies or procedures so long as they 
meet all applicable Federal, State, and Tribal laws. Third, Sec. 132.4 
specifies that for wet-weather point sources, States and Tribes 
generally do not have to adopt and apply the final Guidance 
implementation procedures. The exception is the TMDL general condition 
for wet weather events. Fourth, pursuant to section 510 of the CWA, 
part 132 specifies that nothing in the final Guidance prohibits States 
or Tribes from adopting provisions more stringent than the final 
Guidance.
    As discussed further in section IX of this preamble, Sec. 132.4 
also provides that State and Tribal submissions will need to include 
any provisions that EPA determines, based on EPA's authorities under 
the CWA and the results of consultation with the U.S. Fish and Wildlife 
Service (FWS) under section 7 of the ESA, are necessary to ensure that 
water quality is not likely to cause jeopardy to any endangered or 
threatened species listed under the ESA.
    Part 132 extends the requirements of section 118(c)(2)(C) to Indian 
Tribes within the Great Lakes basin for which EPA has approved water 
quality standards under section 303 of the CWA or which EPA has 
authorized to administer an NPDES program under section 402 of the CWA. 
EPA believes that inclusion of Great Lakes Tribes in this way is 
necessary and appropriate to be consistent with section 518 of the CWA. 
The reasons for EPA's proposal are discussed further in the preamble to 
the proposed Guidance (58 FR 20834), and section II.D.3 of the SID. As 
a practical matter, no Great Lakes Tribes currently have approved water 
quality standards or authorized NPDES programs, so the submission 
requirements of part 132 do not apply to any Great Lakes Tribes. Tribes 
that are approved or authorized in the future, however, will need to 
adopt provisions consistent with the final Guidance in their water 
programs.

V. Costs, Cost-Effectiveness and Benefits

(Section IX of the SID)

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), EPA 
must determine whether the regulatory action is ``significant'' and 
therefore subject to Office of Management and Budget (OMB) review and 
the requirements of the Executive Order. The Order defines 
``significant regulatory action'' as one that is likely to result in a 
rule that may:
    (1) Have an annual effect on the economy of $100 million or more or 
adversely affect in a material way the economy, a sector of the 
economy, competition, jobs, the environment, public health or safety, 
or 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 Executive Order 12866, it has been 
determined that this rule is a ``significant regulatory action'' 
because it raises novel policy issues arising out of the development of 
a comprehensive ecosystem-based approach for a large geographic area 
involving several States, Tribal governments, local governments, and a 
large number of regulated dischargers. This approach, including the 
Great Lakes Water Quality Initiative which developed the core concepts 
of the final Guidance, is a unique and precedential approach to the 
implementation of environmental programs. As such, this action was 
submitted to OMB for review pursuant to Executive Order 12866. Changes 
made in response to OMB suggestions or recommendations will be 
documented in the public record.
    The following is a summary of major elements of the ``Regulatory 
Impact Analysis of the Final Great Lakes Water Quality Guidance'' (RIA) 
(EPA 820-B-95-011) that has been prepared in compliance with Executive 
Order 12866. Further discussion is included in section IX of the SID, 
and in the full RIA, which is available in the docket for this 
rulemaking.
    The provisions of the final Guidance are not enforceable 
requirements until adopted by States or Tribes, or promulgated by EPA 
for a particular State or Tribe. Therefore, this publication of the 
final Guidance does not have an immediate effect on dischargers. Until 
actions are taken to promulgate and implement these provisions (or 
equally protective provisions consistent with the final Guidance), 
there will be no economic effect on any dischargers. For the purposes 
of the RIA, EPA's analysis of costs and benefits assumes that either 
State or EPA promulgations occur consistent with the final Guidance 
within the next two years.
    Under the CWA, costs cannot be a basis for adopting water quality 
criteria that will not be protective of designated uses. If a range of 
scientifically defensible criteria that are protective can be 
identified, however, costs may be considered in selecting a particular 
criterion within that range. Costs may also be relevant under the 
antidegradation standard as applied to high quality waters.
    EPA has assessed compliance costs for facilities that could be 
affected by provisions adopted by States or Tribes consistent with the 
final Guidance. EPA has also assessed basin-wide risk reduction 
benefits to sport anglers and Native American subsistence anglers in 
the basin, and benefits for three case study sites in the Great Lakes 
System. [[Page 15381]] The methodology used in each assessment and the 
results of these assessments are discussed below.
    EPA solicited public comment and supporting data on the RIA 
methodology used to estimate both costs and benefits for implementation 
of the proposed Guidance. EPA evaluated these comments and supporting 
data as well as comments provided by OMB and revised the RIA 
methodology prior to performing these assessments for the final 
Guidance.

A. Costs

    Based on the information provided by each State and a review of the 
permit files, EPA identified about 3,800 direct dischargers that could 
be affected by State or Tribal adoption or subsequent EPA promulgation, 
if necessary, of requirements consistent with the final Guidance. Of 
these, about 590 are major dischargers and the remaining 3,210 are 
minor dischargers. Of the 590 majors, about 275 are industrial 
facilities and 315 are publicly owned treatment works (POTWs). Out of 
these dischargers, EPA used a stratified random sampling procedure to 
select 59 facilities (50 major and nine minor) that it considered 
representative of all types and sizes of facilities in the basin.
    EPA divided the major facilities into nine industrial categories 
and a category for POTWs. The nine industrial categories are: mining, 
food and food products, pulp and paper, inorganic chemical 
manufacturing, organic chemical manufacturing/petroleum refining, 
metals manufacturing, electroplating/metal fabrication, steam electric 
power plants, and miscellaneous facilities.
    For each major and minor facility in the sample, EPA estimated 
incremental costs to comply with subsequently promulgated provisions 
consistent with the final Guidance, using a baseline of compliance with 
the requirements of section 303(c)(2)(B) of the CWA. Using a decision 
matrix, costs were developed for two different scenarios--a ``low-end'' 
cost scenario and a ``high-end'' cost scenario--to account for the 
range of regulatory flexibility available to States and Tribes when 
adopting and implementing provisions consistent with the final 
Guidance. In addition, the decision matrix specified assumptions used 
for selection of control options in the cost analysis such as 
optimization of existing treatment processes and operations, in-plant 
pollutant minimization and prevention, and ``end of pipe'' effluent 
treatment.
    The annualized costs for direct and indirect dischargers to 
implement the final Guidance are estimated to be between $60 million 
(low end) and $380 million (high end) (first quarter 1994 dollars). EPA 
believes the costs for implementing the final Guidance, which balance 
pollution prevention, ``end-of-pipe'' treatment and regulatory 
flexibility, will approach the low end of the cost range. Costs are 
unlikely to reach the high end of the cost range because State and 
Tribal authorities are likely to choose implementation options that 
provide some degree of relief to point source dischargers, especially 
because in many cases the nonpoint source contributions will be 
significant. Furthermore, cost estimates for both scenarios, but 
especially for the high-end scenario, may be overstated because in 
cases where the final Guidance provides States and Tribes flexibility 
in selecting less costly approaches when implementing provisions 
consistent with the final Guidance, the most costly approach was used 
to estimate the costs. This approach was used to reduce uncertainty in 
the cost analysis for the final Guidance.
    Under the low-end cost scenario, major industrial facilities and 
POTWs would account for about 65 percent of the costs, indirect 
dischargers about 33 percent, and minor dischargers about two percent. 
Among the major dischargers three categories would account for most of 
the costs--POTWs (39 percent), pulp and paper (14 percent), and 
miscellaneous (eight percent). The average per plant costs for 
different industry categories range from zero to $168,000. The two 
highest average cost categories are pulp and paper ($151,000) and 
miscellaneous ($168,000). Although major POTWs make up a large portion 
of the total cost, the average cost per plant under the low-end 
scenario is not among the highest at $75,000 per facility. About half 
of the low-end costs are associated with pollution prevention 
activities, and about half are for capital and operating costs for 
wastewater treatment.
    For the high-end cost scenario, direct dischargers account for 98 
percent of the total estimated cost, and indirect dischargers account 
for two percent. This shift in proportion of costs between direct and 
indirect dischargers and between the low and the high estimates are due 
to the assumption that more direct dischargers will need to use end-of-
pipe treatment under the high-end scenario. In addition, it was assumed 
that a smaller proportion of indirect dischargers (10 percent) would be 
impacted under the high-end scenario, since municipalities are adding 
end-of-pipe treatment which should reduce the need for source controls 
(i.e., reduce the need for increased pretreatment program efforts) by 
indirect discharges. Less than 10 percent of the high-end costs are 
associated with pollution prevention activities, and over 90 percent 
are for capital and operating costs for wastewater treatment.
    Under the high-end scenario for the direct dischargers, municipal 
major dischargers are expected to incur just under 70 percent of total 
costs, and industrial major dischargers account for 29 percent of total 
costs. Minor direct dischargers are estimated to incur less than one 
percent of the total costs. The two major industrial categories with 
the largest total annualized cost are the pulp and paper (23 percent of 
total) and miscellaneous (three percent) categories. The food and food 
products and metal finishing categories are estimated to incur less 
than 1 percent of the total annualized cost.
    Under the high-end scenario, the average annual cost per major 
municipal facility is just over $822,000 per facility. Average 
annualized costs for industrial majors vary widely across categories, 
with the highest average cost estimated for pulp and paper ($1,583,000 
per plant) and miscellaneous ($433,700 per plant) categories. 
Regardless of the scenario, the average costs for minor facilities are 
negligible at an estimated $500 per facility.
    The costs described above account for the costs of eliminating 
mixing zones for BCCs except in narrow circumstances, costs related to 
implementation of Tier II values, and specific calculated costs related 
to intake credits. The cost assessment also projects the potential cost 
savings across the different scenarios that facilities may realize if 
States or Tribes use existing regulatory relief mechanisms to modify or 
eliminate the need for a WQBEL for an identified pollutant (e.g., 
variances, TMDLs, site-specific modifications to criteria, and changes 
in designated uses).
    In addition to the cost estimates described above, EPA estimated 
the cost to comply with requirements consistent with the 
antidegradation provisions of the final Guidance. This potential future 
cost is expressed as a ``lost opportunity'' cost for facilities 
impacted by the antidegradation requirements. This cost could result in 
the addition of about $22 million each year.

B. Cost-Effectiveness

    EPA estimated the cost-effectiveness of the final Guidance in terms 
of the cost of reducing the loadings of toxic pollutants from point 
sources. The cost-effectiveness (cost per pound removed) is derived by 
dividing the annualized costs of implementing the final 
[[Page 15382]] Guidance by the toxicity-weighted pounds (pound-
equivalents) of pollutants removed. Pound-equivalents are calculated by 
multiplying pounds of each pollutant removed by the toxic weight (based 
on the toxicity of copper) for that pollutant.
    It is estimated that implementation of provisions consistent with 
the final Guidance would be responsible for the reduction of about six 
to eight million toxic pounds per year, or 16 to 22 percent of the 
toxic-weighted baseline for the low- and high-end scenarios, 
respectively. The cost-effectiveness of the scenarios, over the 
baseline, is quite good, ranging from $10 to $50 per pound-equivalent.
    Approximately 80 percent of the pollutant load reduction from 
implementation of the final Guidance, regardless of the scenario, is 
attributable to reducing BCCs as a result of PMPs and end-of-pipe 
treatment. The largest pollutant load reductions occur for chlordane, 
dieldrin, heptachlor, lead, and pentachlorobenzene.
    In a separate analysis, EPA also investigated the cost-
effectiveness of regulating point and nonpoint sources of mercury and 
PCBs, two contaminants associated with fish advisories in the Great 
Lakes basin. Although data and resource constraints limited the 
findings from these analyses, the preliminary results indicate that 
point sources may factor cost-effectively into pollutant reduction 
scenarios. For both contaminants, the cost-effectiveness of point and 
nonpoint source controls are likely to be highly site-specific.

C. Benefits

    The benefits analysis is intended to provide insight into both the 
types and potential magnitude of the economic benefits expected to 
arise as a result of implementation of provisions adopted by States and 
Tribes consistent with the final Guidance. To the extent feasible, 
empirical estimates of the potential magnitude of the benefits are 
developed and then compared to the estimated costs of implementing 
provisions adopted by States and Tribes consistent with the final 
Guidance.
    The benefits analysis is based on a case study approach, using 
benefits transfer applied to three case studies. The case study 
approach was used because it is more amenable to meaningful benefit-
cost analyses than are studies of larger aggregate areas. Although the 
results obtained for a case study site may not apply uniformly to the 
entire Great Lakes basin, the case study approach does provide a 
pragmatic and realistic perspective of how implementation of the final 
Guidance can generate benefits, the types of benefits anticipated, and 
how these benefits compare to costs.
    The case studies include: (1) the lower Fox River drainage, 
including Green Bay, located on Lake Michigan in northeastern 
Wisconsin; (2) the Saginaw River and Saginaw Bay, located on Lake Huron 
in northeastern Michigan; and (3) the Black River, located on Lake Erie 
in north-central Ohio. The case studies were selected from a list of 
candidate sites (i.e., designated Areas of Concern (AOCs) in the Great 
Lakes basin) on the basis of data availability and the relevance of the 
water quality problems to the final Guidance (i.e., areas in which 
problems were more likely to be associated with on-going point source 
discharges rather than historic loadings from Superfund sites and other 
sources). Geographic diversity was also considered in selecting the 
sites so that the analyses might better promote a broad perspective of 
the final Guidance's benefits and costs.
    For each of the three case studies, EPA estimated future toxics-
oriented water quality benefits, and then attributed a percentage of 
these benefits to implementation of the final Guidance. The attribution 
of benefits was based only on the estimated reduction in loadings from 
point sources at the case study sites and information on the relative 
contribution of point sources to total loadings in the basin. EPA did 
not attempt to calculate the longer-term benefits to human health, 
wildlife, and aquatic life once the final Guidance provisions are fully 
implemented by nonpoint sources as well as point sources and the 
minimum protection levels are attained in the ambient water.
    In the Fox River and Green Bay case study, total annual 
undiscounted benefits attributable to the final Guidance range from 
$0.3 million to $8.5 million (first quarter 1994 dollars). Human health 
benefits account for between 29 percent and 72 percent of the estimated 
benefits, recreational fishing accounts for between eight percent and 
45 percent, and nonuse/ecologic benefits account for between nine 
percent and 23 percent. Municipal and industrial dischargers in this 
case study are estimated to incur annualized costs of about $3.6 
million.
    In the Saginaw River/Bay case study, total annual undiscounted 
benefits range from $0.2 million to $7.7 million. Recreational fishing 
benefits account for between 36 percent and 60 percent of the estimated 
benefits, non-use benefits account for between 18 percent and 30 
percent, and human health benefits account for between eight percent 
and 36 percent. Total annualized costs to municipal and industrial 
dischargers are estimated to be about $2.6 million.
    In the Black River case study, total annual undiscounted benefits 
range from $0.4 million to $1.5 million. Recreational fishing benefits 
account for between 48 percent and 63 percent of the estimated 
benefits, and nonuse benefits account for between 32 percent and 44 
percent. Total annualized costs to municipal and industrial dischargers 
are estimated to be $2.1 million.
    An inherent limitation of the case study approach is the inability 
to extrapolate from a limited set of river-based sites to the Great 
Lakes basin as a whole. Accordingly, extrapolation of the case study 
results to the Great Lakes basin is not recommended. However, as noted 
above, the three case studies were selected on the basis of data 
availability, the relative importance of point source discharges to the 
watersheds' problems, and an attempt to portray spatial diversity 
throughout the Great Lakes basin. Thus, there is no reason to conclude 
that the selected sites are not reflective of the basin, even though 
benefits (and costs) tend to be highly site-specific. In addition, the 
benefits extend from the case study rivers into the larger, open-water 
environment of the Great Lakes.
    The representativeness of the case study sites was assessed by 
comparing the percentage of total benefits estimated to accrue in the 
case study areas to the percentage of basin-wide costs incurred by the 
case study sites. Benefits-related measures (such as population, 
recreational angling days, and nonconsumptive recreation days) were 
used in place of total benefits for this analysis because there is no 
estimate of benefits for the entire Great Lakes basin. The three case 
studies combine to account for nearly 14 percent of the total cost of 
the final Guidance, nearly 17 percent of the loadings reductions, and 
from four percent to 10 percent of the benefits proxies (i.e., basin-
wide population, recreational angling, nonconsumptive recreation, and 
commercial fishery harvest). Thus, the three case studies may represent 
a reasonably proportionate share of costs and benefits.
    In addition to the case study analyses, a basin-wide risk 
assessment was conducted for Great Lakes anglers. EPA collected data 
and information on the consumption of Great Lakes basin fish to 
estimate baseline risk levels and reductions in risks due to 
implementation of the final Guidance for two populations at risk: Great 
Lakes sport anglers (including minority and [[Page 15383]] low-income 
anglers) and Native Americans engaged in subsistence fishing in the 
basin. For sport anglers, EPA estimated that the projected reduction in 
loadings from point sources based on controls consistent with the final 
Guidance would result in a reduction of annual excess lifetime cancer 
cases (potential cancer cases assuming a 70-year lifetime exposure 
period) of 2.2 to 4.1 for low-income minorities in lakeshore counties; 
0.4 to 0.8 for other minorities in lakeshore counties; and 21.9 to 41.9 
for all other sport anglers. For Native American subsistence anglers, 
EPA estimated that reductions from point source loadings attributable 
to the final Guidance would result in a reduction of excess lifetime 
cancer cases of between 0.1 and 0.3 using a low fish ingestion scenario 
and 0.5 to 1.1 using a high fish ingestion scenario. Note that these 
estimates do not include the long-term benefits (including reduced 
cancer cases) that will result once the final Guidance provisions are 
fully implemented and the minimum protection levels are attained in the 
ambient water.
    In total, using the most conservative consumption scenario for 
Native Americans, these reductions represent between 0.35 and 0.67 
excess cancer cases per year, and potential basin-wide benefits of the 
final Guidance for this one benefits category of between $0.7 million 
and $6.7 million per year, based on the estimated value of a 
statistical life of between $2.0 million and $10.0 million. Comparison 
to case study results, which were based on a more comprehensive sample 
of facilities within case study areas than was possible for the entire 
basin, indicates these values likely underestimate the potential risk 
reduction benefits of the final Guidance at the basin level. For 
example, if the average percentage load reduction for PCBs for the 
three case studies is used to reflect reductions in PCBs for the basin, 
the reduction in excess cancer cases increases to between three and six 
cases per year, and potential benefits increase to between $6.6 and $60 
million per year.
    The reduction in pollutant loadings for PCBs was likely understated 
in the basin-wide analysis because the analysis did not count pollutant 
load reduction benefits when the current State-based permit limit and 
the final Guidance-based permit limit were both below the pollutant 
analytical method detection limit (MDL). Only three sample facilities 
in the population of 59 sample facilities used to project basin-wide 
costs and human health benefits had State-based permit limits for PCBs. 
Since the current State-based permit limit and the final Guidance-based 
permit limit were below the MDL in all three facilities, ``zero'' 
reduction in PCB loadings for the basin was estimated. This, of course, 
is an artifact of the methodology and the size of the sample population 
selected for the analysis, and would not occur, as demonstrated in the 
case study analysis, if a larger sample population had been used.

VI. Regulatory Flexibility Act

    Under the Regulatory Flexibility Act (RFA), EPA generally is 
required to conduct a final regulatory flexibility analysis (FRFA) 
describing the impact of the regulatory action on small entities as 
part of the final rulemaking. However, under section 605(b) of the RFA, 
if EPA certifies that the rule will not have a significant economic 
impact on a substantial number of small entities, EPA is not required 
to prepare a FRFA.
    Implementation of the final Guidance is dependent upon future 
promulgation of provisions consistent with it by State or Tribal 
agencies or, if necessary, EPA. Until actions are taken to promulgate 
and implement these provisions, or equally protective provisions 
consistent with the final Guidance, there will be no economic effect of 
this rule on any entities, large or small. For that reason, and 
pursuant to Section 605(b) of the RFA, EPA is certifying that this rule 
itself will not have a significant economic impact on a substantial 
number of small entities.
    Although EPA is certifying that this rule will not have a 
significant economic impact on a substantial number of small entities, 
and therefore is not required to prepare a FRFA, it is nevertheless 
including for public information in the RIA a discussion of the 
possible economic effects to small entities that could result from 
State or Tribal adoption of provisions consistent with the final 
Guidance or subsequent EPA promulgation, if necessary. As discussed 
above, small facilities are projected to incur costs of only 
approximately $500 per facility to comply with subsequently promulgated 
requirements that are consistent with the final Guidance. Accordingly, 
EPA believes there will be no significant economic impact on a 
substantial number of small entities as a result of State or Tribal 
implementation of the final Guidance.

VII. Enhancing the Intergovernmental Partnership Under Executive 
Order 12875

    In compliance with Executive Order 12875 (58 FR 58093, October 28, 
1993), EPA has involved State, Tribal, and local governments in the 
development of the final Guidance.
    As described in section II above, the core elements of the final 
Guidance were developed by the Great Lakes States, EPA, and other 
Federal agencies in open dialogue with citizens, local governments, and 
industries in the Great Lakes ecosystem over a five-year period through 
the Initiative. The Initiative process marks the first time that EPA 
has developed a major rulemaking effort in the water program through a 
regional public forum. The Initiative process is described further in 
the preamble to the proposed Guidance (58 FR 20820-23) and section II 
of this preamble.
    In addition to the participation by State and local governments in 
the initial development of the proposed Guidance and in the public 
comment process, several activities have been carried out since the 
publication of the proposed Guidance. These include:
    (1) On April 26, 1994, EPA held a public meeting to solicit 
additional information from interested parties on the proposed 
Guidance. As part of EPA's outreach efforts to State, Tribal and local 
governments, a special invitation was sent inviting elected officials 
and other State, Tribal and local representatives to participate in the 
public meeting. EPA specifically welcomed Tribal and local officials 
and opened the floor to them to hear and discuss their specific 
concerns and views on the final Guidance.
    (2) A series of meetings and teleconferences were held with Great 
Lakes States in early 1994 to discuss their comments on several issues, 
including development of water quality criteria, State adoption 
requirements, WET, BAFs, additivity, compliance schedules, anti-
backsliding, nonpoint sources, and international concerns.
    (3) In October, 1994, EPA met with each individual State in the 
Great Lakes basin to discuss the nature, form, and scope of the 
proposed Guidance, and State concerns with implementation of the 
provisions under consideration. The following issues were discussed at 
each of the meetings: intake credits, antidegradation and EEQ, wildlife 
criteria, excluded pollutants (e.g., ammonia and chlorine), elimination 
of mixing zones, site-specific modifications, fish consumption, 
appropriate degrees of flexibility for implementation (e.g., guidance 
vs. regulation), and implementation procedures.
    (4) In 1994 and 1995, EPA met with representatives of the National 
Wildlife Federation to discuss EPA's activities in developing the final 
Guidance in [[Page 15384]] accordance with the terms of a consent 
decree governing the schedule for development of the final Guidance.
    (5) In 1994, EPA also met with elected officials and other 
representatives from several local communities in the Great Lakes basin 
to discuss issues regarding the economic impact of the proposed 
Guidance on local communities and POTWs. Issues discussed include cost 
impacts associated with implementing water quality criteria, 
methodologies, and implementation procedures; dealing with pollution 
from nonpoint sources; public outreach to control pollutants such as 
mercury instead of costly end-of-pipe treatment; and applicability of 
provisions in the final Guidance to the National water quality program.
    (6) EPA held an additional 18 consultations with the regulated 
community throughout 1994. Such meetings allowed representatives of 
dischargers to share additional data, which has been placed in the 
docket for this rulemaking, and concerns about a range of issues, 
including cost concerns, that the dischargers expect to arise in 
implementation of the final Guidance.
    (7) In 1994, EPA met with State representatives to conduct initial 
planning for implementation of the GLI Clearinghouse. All Great Lakes 
States agreed to participate in this effort, which will involve the 
sharing of toxicological and other data to assist in the development of 
additional water quality criteria and values.
    The results of the above efforts have assisted in the development 
of the final Guidance through broad communication with a full range of 
interested parties, sharing of additional information, and 
incorporation of features to improve the implementation of the final 
Guidance.
    EPA has estimated the total annual State government burden to 
implement the final Guidance as approximately 5,886 hours, resulting in 
a State government cost of $175,992 annually. Such burden and costs 
were estimated based upon the burden and costs associated with 
developing water quality criteria, review of antidegradation policy 
demonstrations, review of approvable control strategies and BCC 
monitoring data, and review of variance requests. The total annual 
local government burden is estimated to be 42,296 hours with an 
associated cost of $2,008,624. All of the burden and costs to local 
governments are associated with being a regulated entity as an operator 
of a POTW.

VIII. Paperwork Reduction Act

    The information collection requirements in this final Guidance have 
been approved by OMB under the Paperwork Reduction Act, 44 U.S.C. 3501 
et seq., and have been assigned OMB control number 2040-0180. EPA has 
prepared an Information Collection Request (ICR) document (ICR No. 
1639.02). A copy of ICR 1639.02 may be obtained by writing to Ms. Sandy 
Farmer, Information Policy Branch, EPA 2136, Washington, D.C. 20460, or 
by calling (202) 260-2740.
    The annual public reporting and record keeping burden for this 
regulation is estimated to be 128,787 hours for the affected 3,795 
permittees, or an average of 34 hours. This includes the total annual 
burden to local governments as POTW operators, estimated to be 45,296 
hours. The total annual burden to State governments is estimated to be 
5,886 hours. These estimates include time for reviewing instructions, 
searching existing data sources, gathering and maintaining the data 
needed, and completing and reviewing the collection of information.
    Send comments regarding the burden estimate or any other aspect of 
this collection of information, including suggestions for reducing this 
burden to Chief, Information Policy Branch, Mail Code 2136, U.S. 
Environmental Protection Agency, 401 M St., S.W., Washington, DC 20460; 
and to the Office of Information and Regulatory Affairs, Office of 
Management and Budget, Washington, DC 20503.
    In this rulemaking EPA is also amending the table of currently 
approved ICR control numbers issued by OMB for various regulations into 
40 CFR 9.1. This amendment updates the table to accurately display 
those information requirements promulgated under the CWA. The affected 
regulations are codified at 40 CFR parts 122, 123, 131, and 132. EPA 
will continue to present OMB control numbers in a consolidated table 
format. The table will be codified in 40 CFR part 9 of EPA's 
regulations and in each 40 CFR volume containing EPA regulations. The 
table lists the section numbers with reporting and recordkeeping 
requirements, and the current OMB control numbers. This display of the 
OMB control numbers and their subsequent codification in the CFR 
satisfies the requirements of the Paperwork Reduction Act (44 U.S.C. 
3501 et seq.) and OMB's implementing regulations at 5 CFR part 1320.
    The ICR for this rulemaking was previously subject to public notice 
and comment prior to OMB approval. As a result, EPA finds that there is 
``good cause'' under section 553(b)(B) of the Administrative Procedure 
Act (5 U.S.C. 553(b)(B)) to amend this table without prior notice and 
comment. Due to the technical nature of the table, further notice and 
comment would be unnecessary.

IX. Endangered Species Act

    Pursuant to section 7(a)(2) of the ESA, EPA consulted with the FWS 
concerning EPA's publication of the final Guidance. EPA and the FWS 
have now completed both informal and formal consultation conducted over 
a two-year period.
    As a result of the consultation, as well as an analysis of 
comments, EPA modified several provisions of the final Guidance. The 
procedure for site-specific modifications provides that Great Lakes 
States and Tribes must make site-specific modifications to criteria and 
values where necessary to ensure the resulting water quality does not 
cause jeopardy to listed or proposed species. Similarly, the 
antidegradation policy and implementation procedures restrict certain 
actions States and Tribes may take to allow lowering of water quality 
in high quality waters, or to adopt variances or mixing zones. 
Additionally, the regulatory requirements were modified to require 
Great Lakes States and Tribes to include in their part 132 submissions 
any provisions that EPA determines, based on EPA's authorities under 
the CWA and the results of consultation under section 7 of the ESA, are 
necessary to ensure that water quality is not likely to cause jeopardy 
to listed species. EPA and the FWS also agreed on how further 
consultations will be conducted as the final Guidance is implemented. 
The two agencies also agreed that EPA will undertake a review of water 
quality standards and implementation of those standards for ammonia and 
chlorine in the Great Lakes basin as part of EPA's responsibilities 
under section 303(c) of the CWA.
    During the consultation, two issues were identified that required 
formal consultation, as defined in 40 CFR part 402. These issues were: 
the absence of toxicological data concerning effects of contaminants on 
three species of freshwater mussels in the Great Lakes basin, and the 
adequacy of the wildlife criteria methodology to protect three 
endangered or threatened wildlife species in the basin. On February 21, 
1995, the FWS provided EPA with a written Biological Opinion (Opinion) 
on these issues. The Opinion is available in the docket for this 
rulemaking. On both issues, the FWS concluded that the water quality 
resulting from implementation of the final Guidance will not cause 
jeopardy to the listed species. To minimize the amount or extent of any 
incidental take that might [[Page 15385]] occur, the FWS consulted 
closely with EPA to develop a coordinated approach. The final Opinion 
specified reasonable and prudent measures that the FWS considers 
necessary or appropriate to minimize such impact. EPA has agreed to 
implement the measures, and the FWS and EPA will continue to work 
cooperatively during the implementation.

X. Judicial Review of Provisions Not Amended

    In some situations, EPA has renumbered or included other editorial 
changes to regulations that have been promulgated in past rulemakings. 
Additionally, to provide for ease in reading changes to existing 
regulations, EPA has in some cases repeated entire sections, including 
portions not changed. The promulgation of this final rule, however, 
does not provide another opportunity to seek judicial review on the 
substance of the existing regulations.

XI. Supporting Documents

    All documents that are referenced in this preamble are available 
for inspection and photocopying in the docket for this rulemaking at 
the address listed at the beginning of this preamble. A reasonable fee 
will be charged for photocopies.
    Selected documents supporting the final Guidance are also available 
for viewing by the public at locations listed below:
    Illinois: Illinois State Library, 300 South 2nd Street, 
Springfield, IL 62701 (217-785-5600)
    Indiana: Indiana Department of Environmental Management, Office of 
Water Management, 100 North Senate Street, Indianapolis, IN 46204 (317-
232-8671)
    Michigan: Library of Michigan, Government Documents Service, 717 
West Allegan, Lansing, MI 48909 (517-373-1300); Detroit Public Library, 
Sociology and Economics Department, 5201 Woodward Avenue, Detroit, MI 
48902 (313-833-1440)
    Minnesota: Minnesota Pollution Control Agency, Library, 520 
Lafayette, St. Paul, MN (612-296-7719)
    New York: U.S. EPA Region 2 Library, Room 402, 26 Federal Plaza, 
New York, NY 10278 (212-264-2881); U.S. EPA Public Information Office, 
Carborundum Center, Suite 530, 345 Third Street, Niagara Falls, NY 
14303 (716-285-8842); New York State Department of Environmental 
Conservation (NYSDEC), Room 310, 50 Wolf Road, Albany, NY 12333 (518-
457-7463); NYSDEC, Region 6, 7th Floor, State Office Building, 317 
Washington Street, Watertown, NY 13602 (315-785-2513); NYSDEC, Region 
7, 615 Erie Boulevard West, Syracuse, NY 13204 (315-426-7400); NYSDEC, 
Region 8, 6274 East Avon-Lima Road, Avon, NY 14414 (716-226-2466); 
NYSDEC, Region 9, 270 Michigan Avenue, Buffalo, NY 14203 (716-851-7070)
    Ohio: Ohio Environmental Protection Agency Library--Central 
District Office, 1800 Watermark Road, Columbus, OH 43215 (614-644-
3024); U.S. EPA Eastern District Office, 25809 Central Ridge Road, 
Westlake, OH 44145 (216-522-7260)
    Pennsylvania: Pennsylvania Department of Environmental Resources, 
230 Chestnut Street, Meadville, PA 16335 (814-332-6945); U.S. EPA 
Region 3 Library, 8th Floor, 841 Chestnut Building, Philadelphia, PA 
19107-4431 (215-597-7904)
    Wisconsin: Water Resources Center, University of Wisconsin-Madison, 
2nd Floor, 1975 Willow Drive, Madison, WI (608-262-3069)
    EPA is also making a number of documents available in electronic 
format at no incremental cost to users of the Internet. These documents 
include the contents of this Federal Register document, the SID, many 
documents listed below, and other supporting materials.
    The documents listed below are also available for a fee upon 
written request or telephone call to the National Technical Information 
Center (NTIS), U.S. Department of Commerce, 5285 Port Royal Road, 
Springfield, VA 22161 (telephone 800-553-6847 or 703-487-4650). 
Alternatively, copies may be obtained for a fee upon written request or 
telephone call to the Educational Resources Information Center/
Clearinghouse for Science, Mathematics, and Environmental Education 
(ERIC/CSMEE), 1200 Chambers Road, Room 310, Columbus, OH 43212 (614-
292-6717). When ordering, please include the NTIS or ERIC/CSMEE 
accession number.
    A. Final Water Quality Guidance for the Great Lakes System: 
Supplementary Information Document (SID). NTIS Number: PB95187266. ERIC 
Number: D046.
    B. Great Lakes Water Quality Initiative Criteria Document for the 
Protection of Aquatic Life in Ambient Water. NTIS Number: PB95187282. 
ERIC Number: D048.
    C. Great Lakes Water Quality Initiative Technical Support Document 
for the Procedure to Determine Bioaccumulation Factors. NTIS Number: 
PB95187290. ERIC Number: D049.
    D. Great Lakes Water Quality Initiative Criteria Document for the 
Protection of Human Health. NTIS Number: PB95187308. ERIC Number: D050.
    E. Great Lakes Water Quality Initiative Technical Support Document 
for Human Health Criteria and Values. NTIS Number: PB95187316. ERIC 
Number: D051.
    F. Great Lakes Water Quality Initiative Criteria Document for the 
Protection of Wildlife: DDT; Mercury; 2,3,7,8-TCDD; PCBs. NTIS Number: 
PB95187324. ERIC Number: D052.
    G. Great Lakes Water Quality Initiative Technical Support Document 
for Wildlife Criteria. NTIS Number: PB95187332. ERIC Number: D053.
    H. Assessment of Compliance Costs Resulting from Implementation of 
the Final Great Lakes Water Quality Guidance. NTIS Number: PB95187340. 
ERIC Number: D054.
    I. Regulatory Impact Analysis of the Final Great Lakes Water 
Quality Guidance. NTIS Number: PB95187357. ERIC Number: D055.

List of Subjects

40 CFR Part 9

    Reporting and recordkeeping requirements.

40 CFR Part 122

    Administrative practice and procedure, Confidential business 
information, Great Lakes, Hazardous substances, Reporting and 
recordkeeping requirements, Water pollution control.

40 CFR Part 123

    Administrative practice and procedure, Confidential business 
information, Great Lakes, Hazardous substances, Indians-lands, 
Intergovernmental relations, Penalties, Reporting and recordkeeping 
requirements, Water pollution control.

40 CFR Part 131

    Great Lakes, Reporting and recordkeeping requirements, Water 
pollution control.

40 CFR Part 132

    Administrative practice and procedure, Great Lakes, Indians-lands, 
Intergovernmental relations, Reporting and recordkeeping requirements, 
Water pollution control.

    Dated: March 13, 1995.
Carol M. Browner,
Administrator.

    For the reasons set out in the preamble, title 40, chapter I, parts 
9, 122, 123, and 131 are amended, and part 132 is added as follows: 
[[Page 15386]] 

PART 9--OMB APPROVALS UNDER THE PAPERWORK REDUCTION ACT

    1. The authority citation for part 9 continues to read as follows:

    Authority: 7 U.S.C. 135 et seq., 136-136y; 15 U.S.C. 2001, 2003, 
2005, 2006, 2601-2671; 21 U.S.C. 331j, 346a, 348; 31 U.S.C. 9701; 33 
U.S.C. 1251 et seq., 1311, 1313d, 1314, 1318, 1321, 1326, 1330, 
1342, 1344, 1345 (d) and (e), 1361; E.O. 11735, 38 FR 21243, 3 CFR, 
1971-1975 Comp. p. 973; 42 U.S.C. 241, 242b, 243, 246, 300f, 300g, 
300g-1, 300g-2, 300g-3, 300g-4, 300g-5, 300g-6, 300j-1, 300j-2, 
300j-3, 300j-4, 300j-9, 1857 et seq., 6901-6992k, 7401-7671q, 7542, 
9601-9657, 11023, 11048.

    2. Section 9.1 is amended as follows:
    a. By adding in numerical order the entry ``122.44(r)'' under the 
heading ``EPA Administered Permit Programs: The National Pollutant 
Discharge Elimination System''.
    b. By revising the entries under the heading ``State Permit 
Requirements'';
    c. By adding in numerical order the entries ``131.1'' and ``131.5'' 
and by revising the entries ``131.20'', ``131.21'' and ``131.22'' under 
the heading ``Water Quality Standards Regulations''; and
    d. By adding in numerical order a new heading and new entries for 
``Water Quality Guidance for the Great Lakes System'' to read as 
follows:


Sec. 9.1  OMB approvals under the Paperwork Reduction Act.

* * * * *

                                                                        
                    40 CFR citation                      OMB control No.
                                                                        
   EPA Administered Permit Programs: The National Pollutant Discharge   
                           Elimination System                           
                                                                        
                  *        *        *        *        *                 
122.44(r).............................................  2040-0180       
                 *        *        *        *        *                  
                       State Permit Requirements                        
123.21-123.24.........................................  2040-0057,      
                                                        2040-0170       
123.25................................................  2040-0004,      
                                                        2040-0110,      
                                                        2040-0170,      
                                                        2040-0180       
123.26-123.29.........................................  2040-0057,      
                                                        2040-0170       
123.43................................................  2040-0057,      
                                                        2040-0170       
123.44................................................  2040-0057,      
                                                        2040-0170,      
                                                        2040-0180       
123.45................................................  2040-0057,      
                                                        2040-0170       
123.62................................................  2040-0057,      
                                                        2040-0170,      
                                                        2040-0180       
123.63................................................  2040-0057,      
                                                        2040-0170,      
                                                        2040-0180       
123.64................................................  2040-0057,      
                                                        2040-0170       
                   Water Quality Standards Regulation                   
131.1.................................................  2040-0180       
131.5.................................................  2040-0180       
                                                                        
                  *        *        *        *        *                 
131.20................................................  2040-0049       
131.21................................................  2040-0049,      
                                                        2040-0180       
131.22................................................  2040-0049       
                                                                        
                 *        *        *        *          *                
           Water Quality Guidance for the Great Lakes System            
132.1.................................................  2040-0180       
132.2.................................................  2040-0180       
132.3.................................................  2040-0180       
132.4.................................................  2040-0180       
132.5.................................................  2040-0180       
Appendix A............................................  2040-0180       
Appendix B............................................  2040-0180       
Appendix C............................................  2040-0180       
Appendix D............................................  2040-0180       
Appendix E............................................  2040-0180       
Appendix F............................................  2040-0180       
                                                                        

* * * * *

PART 122--EPA ADMINISTERED PERMIT PROGRAMS: THE NATIONAL POLLUTANT 
DISCHARGE ELIMINATION SYSTEM

    3. The authority citation for part 122 continues to read as 
follows:

    Authority: The Clean Water Act, 33 U.S.C. 1251 et seq.

    4. Section 122.44 is amended by adding a new paragraph (r) to read 
as follows:


Sec. 122.44  Establishing limitations, standards, and other permit 
conditions (applicable to State NPDES programs, see Sec. 123.25).

* * * * *
    (r) Great Lakes. When a permit is issued to a facility that 
discharges into the Great Lakes System (as defined in 40 CFR 132.2), 
conditions promulgated by the State, Tribe, or EPA pursuant to 40 CFR 
part 132.

PART 123--STATE PROGRAM REQUIREMENTS

    5. The authority citation for part 123 continues to read as 
follows:

    Authority: Clean Water Act, 33 U.S.C. 1251 et seq.

    6. Section 123.25 is amended by removing ``and'' at the end of 
paragraph (a)(36), removing the period at the end of paragraph (a)(37) 
and adding ``; and'' in its place, and adding a new paragraph (a)(38) 
to read as follows:


Sec. 123.25  Requirements for permitting.

    (a) * * *
    (38) For a Great Lakes State or Tribe (as defined in 40 CFR 132.2), 
40 CFR part 132 (NPDES permitting implementation procedures only).
* * * * *
    7. Section 123.44 is amended by adding a new paragraph (c)(9) to 
read as follows:


Sec. 123.44  EPA review of and objections to State permits.

* * * * *
    (c) * * *
    (9) For a permit issued by a Great Lakes State or Tribe (as defined 
in 40 CFR 132.2), the permit does not satisfy the conditions 
promulgated by the State, Tribe, or EPA pursuant to 40 CFR part 132.
* * * * *
    8. Section 123.62 is amended by adding a new paragraph (f) to read 
as follows:


Sec. 123.62  Procedures for revision of State programs.

* * * * *
    (f) Revision of a State program by a Great Lakes State or Tribe (as 
defined in 40 CFR 132.2) to conform to section 118 of the CWA and 40 
CFR part 132 shall be accomplished pursuant to 40 CFR part 132.
    9. Section 123.63 is amended by adding a new paragraph (a)(6) and 
adding and reserving paragraph (b) to read as follows:


Sec. 123.63  Criteria for withdrawal of State programs.

    (a) * * *
    (6) Where a Great Lakes State or Tribe (as defined in 40 CFR 132.2) 
fails to adequately incorporate the NPDES permitting implementation 
procedures promulgated by the State, Tribe, or EPA pursuant to 40 CFR 
part 132 into individual permits.
    (b) [Reserved]

PART 131--WATER QUALITY STANDARDS

    10. The authority citation for part 131 continues to read as 
follows:

    Authority: 33 U.S.C. 1251 et seq.

    11. Section 131.1 is revised to read as follows:


Sec. 131.1  Scope.

    This part describes the requirements and procedures for developing, 
reviewing, revising, and approving water quality standards by the 
States as authorized by section 303(c) of the Clean Water Act. 
Additional specific procedures for developing, reviewing, revising, and 
approving water quality standards for Great Lakes States or Great Lakes 
Tribes (as defined in 40 CFR 132.2) to conform to section 118 of the 
[[Page 15387]] Clean Water Act and 40 CFR part 132, are provided in 40 
CFR part 132.
    12. Section 131.5 is amended by revising paragraph (a)(5), by 
redesignating paragraph (b) as paragraph (c), and by adding a new 
paragraph (b) to read as follows:


Sec. 131.5  EPA Authority.

    (a) * * *
    (5) Whether the State submission meets the requirements included in 
Sec. 131.6 of this part and, for Great Lakes States or Great Lakes 
Tribes (as defined in 40 CFR 132.2) to conform to section 118 of the 
Act, the requirements of 40 CFR part 132.
    (b) If EPA determines that the State's or Tribe's water quality 
standards are consistent with the factors listed in paragraphs (a)(1) 
through (a)(5) of this section, EPA approves the standards. EPA must 
disapprove the State's or Tribe's water quality standards and 
promulgate Federal standards under section 303(c)(4), and for Great 
Lakes States or Great Lakes Tribes under section 118(c)(2)(C) of the 
Act, if State or Tribal adopted standards are not consistent with the 
factors listed in paragraphs (a)(1) through (a)(5) of this section. EPA 
may also promulgate a new or revised standard when necessary to meet 
the requirements of the Act.
* * * * *
    13. Section 131.21 is amended by revising paragraph (b) to read as 
follows:


Sec. 131.21  EPA review and approval of water quality standards.

* * * * *
    (b) The Regional Administrator's approval or disapproval of a State 
water quality standard shall be based on the requirements of the Act as 
described in Secs. 131.5 and 131.6, and, with respect to Great Lakes 
States or Tribes (as defined in 40 CFR 132.2), 40 CFR part 132.
* * * * *
    14. Part 132 is added as follows:

PART 132--WATER QUALITY GUIDANCE FOR THE GREAT LAKES SYSTEM

Sec.
132.1  Scope, purpose, and availability of documents.
132.2  Definitions.
132.3  Adoption of criteria.
132.4   State adoption and application of methodologies, policies 
and procedures.
132.5  Procedures for adoption and EPA review.
132.6  Application of part 132 requirements in Great Lakes States 
and Tribes. [Reserved]

Tables to Part 132

Appendix A to Part 132--Great Lakes Water Quality Initiative 
Methodologies for Development of Aquatic Life Criteria and Values
Appendix B to Part 132--Great Lakes Water Quality Initiative 
Methodology for Development of Bioaccumulation Factors
Appendix C to Part 132--Great Lakes Water Quality Initiative 
Methodology for Development of Human Health Criteria and Values
Appendix D to Part 132--Great Lakes Water Quality Initiative 
Methodology for the Development of Wildlife Criteria
Appendix E to Part 132--Great Lakes Water Quality Initiative 
Antidegradation Policy
Appendix F to Part 132--Great Lakes Water Quality Initiative 
Implementation Procedures

    Authority: 33 U.S.C. 1251 et seq.


Sec. 132.1  Scope, purpose, and availability of documents.

    (a) This part constitutes the Water Quality Guidance for the Great 
Lakes System (Guidance) required by section 118(c)(2) of the Clean 
Water Act (33 U.S.C. 1251 et seq.) as amended by the Great Lakes 
Critical Programs Act of 1990 (Pub. L. 101-596, 104 Stat. 3000 et 
seq.). The Guidance in this part identifies minimum water quality 
standards, antidegradation policies, and implementation procedures for 
the Great Lakes System to protect human health, aquatic life, and 
wildlife.
    (b) The U.S. Environmental Protection Agency, Great Lakes States, 
and Great Lakes Tribes will use the Guidance in this part to evaluate 
the water quality programs of the States and Tribes to assure that they 
are protective of water quality. State and Tribal programs do not need 
to be identical to the Guidance in this part, but must contain 
provisions that are consistent with (as protective as) the Guidance in 
this part. The scientific, policy and legal basis for EPA's development 
of each section of the final Guidance in this part is set forth in the 
preamble, Supplementary Information Document, Technical Support 
Documents, and other supporting documents in the public docket. EPA 
will follow the guidance set out in these documents in reviewing the 
State and Tribal water quality programs in the Great Lakes for 
consistency with this part.
    (c) The Great Lakes States and Tribes must adopt provisions 
consistent with the Guidance in this part applicable to waters in the 
Great Lakes System or be subject to EPA promulgation of its terms 
pursuant to this part.
    (d) EPA understands that the science of risk assessment is rapidly 
improving. Therefore, to ensure that the scientific basis for the 
methodologies in appendices A through D are always current and peer 
reviewed, EPA will review the methodologies and revise them, as 
appropriate, every 3 years.
    (e) Certain documents referenced in the appendixes to this part 
with a designation of NTIS and/or ERIC are available for a fee upon 
request to the National Technical Information Center (NTIS), U.S. 
Department of Commerce, 5285 Port Royal Road, Springfield, VA 22161. 
Alternatively, copies may be obtained for a fee upon request to the 
Educational Resources Information Center/Clearinghouse for Science, 
Mathematics, and Environmental Education (ERIC/CSMEE), 1200 Chambers 
Road, Room 310, Columbus, Ohio 43212. When ordering, please include the 
NTIS or ERIC/CSMEE accession number.


Sec. 132.2  Definitions.

    The following definitions apply in this part. Terms not defined in 
this section have the meaning given by the Clean Water Act and EPA 
implementing regulations.
    Acute-chronic ratio (ACR) is a standard measure of the acute 
toxicity of a material divided by an appropriate measure of the chronic 
toxicity of the same material under comparable conditions.
    Acute toxicity is concurrent and delayed adverse effect(s) that 
results from an acute exposure and occurs within any short observation 
period which begins when the exposure begins, may extend beyond the 
exposure period, and usually does not constitute a substantial portion 
of the life span of the organism.
    Adverse effect is any deleterious effect to organisms due to 
exposure to a substance. This includes effects which are or may become 
debilitating, harmful or toxic to the normal functions of the organism, 
but does not include non-harmful effects such as tissue discoloration 
alone or the induction of enzymes involved in the metabolism of the 
substance.
    Bioaccumulation is the net accumulation of a substance by an 
organism as a result of uptake from all environmental sources.
    Bioaccumulation factor (BAF) is the ratio (in L/kg) of a 
substance's concentration in tissue of an aquatic organism to its 
concentration in the ambient water, in situations where both the 
organism and its food are exposed and the ratio does not change 
substantially over time.
    Bioaccumulative chemical of concern (BCC) is any chemical that has 
the potential to cause adverse effects which, upon entering the surface 
waters, by itself or as its toxic transformation 
[[Page 15388]] product, accumulates in aquatic organisms by a human 
health bioaccumulation factor greater than 1000, after considering 
metabolism and other physicochemical properties that might enhance or 
inhibit bioaccumulation, in accordance with the methodology in appendix 
B of this part. Chemicals with half-lives of less than eight weeks in 
the water column, sediment, and biota are not BCCs. The minimum BAF 
information needed to define an organic chemical as a BCC is either a 
field-measured BAF or a BAF derived using the BSAF methodology. The 
minimum BAF information needed to define an inorganic chemical, 
including an organometal, as a BCC is either a field-measured BAF or a 
laboratory-measured BCF. BCCs include, but are not limited to, the 
pollutants identified as BCCs in section A of Table 6 of this part.
    Bioconcentration is the net accumulation of a substance by an 
aquatic organism as a result of uptake directly from the ambient water 
through gill membranes or other external body surfaces.
    Bioconcentration factor (BCF) is the ratio (in L/kg) of a 
substance's concentration in tissue of an aquatic organism to its 
concentration in the ambient water, in situations where the organism is 
exposed through the water only and the ratio does not change 
substantially over time.
    Biota-sediment accumulation factor (BSAF) is the ratio (in kg of 
organic carbon/kg of lipid) of a substance's lipid-normalized 
concentration in tissue of an aquatic organism to its organic carbon-
normalized concentration in surface sediment, in situations where the 
ratio does not change substantially over time, both the organism and 
its food are exposed, and the surface sediment is representative of 
average surface sediment in the vicinity of the organism.
    Carcinogen is a substance which causes an increased incidence of 
benign or malignant neoplasms, or substantially decreases the time to 
develop neoplasms, in animals or humans. The classification of 
carcinogens is discussed in section II.A of appendix C to part 132.
    Chronic toxicity is concurrent and delayed adverse effect(s) that 
occurs only as a result of a chronic exposure.
    Connecting channels of the Great Lakes are the Saint Mary's River, 
Saint Clair River, Detroit River, Niagara River, and Saint Lawrence 
River to the Canadian Border.
    Criterion continuous concentration (CCC) is an estimate of the 
highest concentration of a material in the water column to which an 
aquatic community can be exposed indefinitely without resulting in an 
unacceptable effect.
    Criterion maximum concentration (CMC) is an estimate of the highest 
concentration of a material in the water column to which an aquatic 
community can be exposed briefly without resulting in an unacceptable 
effect.
    EC50 is a statistically or graphically estimated concentration that 
is expected to cause one or more specified effects in 50 percent of a 
group of organisms under specified conditions.
    Endangered or threatened species are those species that are listed 
as endangered or threatened under section 4 of the Endangered Species 
Act.
    Existing Great Lakes discharger is any building, structure, 
facility, or installation from which there is or may be a ``discharge 
of pollutants'' (as defined in 40 CFR 122.2) to the Great Lakes System, 
that is not a new Great Lakes discharger.
    Federal Indian reservation, Indian reservation, or reservation 
means all land within the limits of any Indian reservation under the 
jurisdiction of the United States Government, notwithstanding the 
issuance of any patent, and including rights-of-way running through the 
reservation.
    Final acute value (FAV) is (a) a calculated estimate of the 
concentration of a test material such that 95 percent of the genera 
(with which acceptable acute toxicity tests have been conducted on the 
material) have higher GMAVs, or (b) the SMAV of an important and/or 
critical species, if the SMAV is lower than the calculated estimate.
    Final chronic value (FCV) is (a) a calculated estimate of the 
concentration of a test material such that 95 percent of the genera 
(with which acceptable chronic toxicity tests have been conducted on 
the material) have higher GMCVs, (b) the quotient of an FAV divided by 
an appropriate acute-chronic ratio, or (c) the SMCV of an important 
and/or critical species, if the SMCV is lower than the calculated 
estimate or the quotient, whichever is applicable.
    Final plant value (FPV) is the lowest plant value that was obtained 
with an important aquatic plant species in an acceptable toxicity test 
for which the concentrations of the test material were measured and the 
adverse effect was biologically important.
    Genus mean acute value (GMAV) is the geometric mean of the SMAVs 
for the genus.
    Genus mean chronic value (GMCV) is the geometric mean of the SMCVs 
for the genus.
    Great Lakes means Lake Ontario, Lake Erie, Lake Huron (including 
Lake St. Clair), Lake Michigan, and Lake Superior; and the connecting 
channels (Saint Mary's River, Saint Clair River, Detroit River, Niagara 
River, and Saint Lawrence River to the Canadian Border).
    Great Lakes States and Great Lakes Tribes, or Great Lakes States 
and Tribes means the States of Illinois, Indiana, Michigan, Minnesota, 
New York, Ohio, Pennsylvania, and Wisconsin, and any Indian Tribe as 
defined in this part which is located in whole or in part within the 
drainage basin of the Great Lakes, and for which EPA has approved water 
quality standards under section 303 of the Clean Water Act or which EPA 
has authorized to administer an NPDES program under section 402 of the 
Clean Water Act.
    Great Lakes System means all the streams, rivers, lakes and other 
bodies of water within the drainage basin of the Great Lakes within the 
United States.
    Human cancer criterion (HCC) is a Human Cancer Value (HCV) for a 
pollutant that meets the minimum data requirements for Tier I specified 
in appendix C of this part.
    Human cancer value (HCV) is the maximum ambient water concentration 
of a substance at which a lifetime of exposure from either: drinking 
the water, consuming fish from the water, and water-related recreation 
activities; or consuming fish from the water, and water-related 
recreation activities, will represent a plausible upper-bound risk of 
contracting cancer of one in 100,000 using the exposure assumptions 
specified in the Methodologies for the Development of Human Health 
Criteria and Values in appendix C of this part.
    Human noncancer criterion (HNC) is a Human Noncancer Value (HNV) 
for a pollutant that meets the minimum data requirements for Tier I 
specified in appendix C of this part.
    Human noncancer value (HNV) is the maximum ambient water 
concentration of a substance at which adverse noncancer effects are not 
likely to occur in the human population from lifetime exposure via 
either: drinking the water, consuming fish from the water, and water-
related recreation activities; or consuming fish from the water, and 
water-related recreation activities using the Methodologies for the 
Development of Human Health Criteria and Values in appendix C of this 
part.
    Indian Tribe or Tribe means any Indian Tribe, band, group, or 
community recognized by the Secretary of the Interior and exercising 
governmental authority over a Federal Indian reservation.
    LC50 is a statistically or graphically estimated concentration that 
is expected [[Page 15389]] to be lethal to 50 percent of a group of 
organisms under specified conditions.
    Load allocation (LA) is the portion of a receiving water's loading 
capacity that is attributed either to one of its existing or future 
nonpoint sources or to natural background sources, as more fully 
defined at 40 CFR 130.2(g). Nonpoint sources include: in-place 
contaminants, direct wet and dry deposition, groundwater inflow, and 
overland runoff.
    Loading capacity is the greatest amount of loading that a water can 
receive without violating water quality standards.
    Lowest observed adverse effect level (LOAEL) is the lowest tested 
dose or concentration of a substance which resulted in an observed 
adverse effect in exposed test organisms when all higher doses or 
concentrations resulted in the same or more severe effects.
    Method detection level is the minimum concentration of an analyte 
(substance) that can be measured and reported with a 99 percent 
confidence that the analyte concentration is greater than zero as 
determined by the procedure set forth in appendix B of 40 CFR part 136.
    Minimum Level (ML) is the concentration at which the entire 
analytical system must give a recognizable signal and acceptable 
calibration point. The ML is the concentration in a sample that is 
equivalent to the concentration of the lowest calibration standard 
analyzed by a specific analytical procedure, assuming that all the 
method-specified sample weights, volumes and processing steps have been 
followed.
    New Great Lakes discharger is any building, structure, facility, or 
installation from which there is or may be a ``discharge of 
pollutants'' (as defined in 40 CFR 122.2) to the Great Lakes System, 
the construction of which commenced after March 23, 1997.
    No observed adverse effect level (NOAEL) is the highest tested dose 
or concentration of a substance which resulted in no observed adverse 
effect in exposed test organisms where higher doses or concentrations 
resulted in an adverse effect.
    No observed effect concentration (NOEC) is the highest 
concentration of toxicant to which organisms are exposed in a full 
life-cycle or partial life-cycle (short-term) test, that causes no 
observable adverse effects on the test organisms (i.e., the highest 
concentration of toxicant in which the values for the observed 
responses are not statistically significantly different from the 
controls).
    Open waters of the Great Lakes (OWGLs) means all of the waters 
within Lake Erie, Lake Huron (including Lake St. Clair), Lake Michigan, 
Lake Ontario, and Lake Superior lakeward from a line drawn across the 
mouth of tributaries to the Lakes, including all waters enclosed by 
constructed breakwaters, but not including the connecting channels.
    Quantification level is a measurement of the concentration of a 
contaminant obtained by using a specified laboratory procedure 
calibrated at a specified concentration above the method detection 
level. It is considered the lowest concentration at which a particular 
contaminant can be quantitatively measured using a specified laboratory 
procedure for monitoring of the contaminant.
    Quantitative structure activity relationship (QSAR) or structure 
activity relationship (SAR) is a mathematical relationship between a 
property (activity) of a chemical and a number of descriptors of the 
chemical. These descriptors are chemical or physical characteristics 
obtained experimentally or predicted from the structure of the 
chemical.
    Risk associated dose (RAD) is a dose of a known or presumed 
carcinogenic substance in (mg/kg)/day which, over a lifetime of 
exposure, is estimated to be associated with a plausible upper bound 
incremental cancer risk equal to one in 100,000.
    Species mean acute value (SMAV) is the geometric mean of the 
results of all acceptable flow-through acute toxicity tests (for which 
the concentrations of the test material were measured) with the most 
sensitive tested life stage of the species. For a species for which no 
such result is available for the most sensitive tested life stage, the 
SMAV is the geometric mean of the results of all acceptable acute 
toxicity tests with the most sensitive tested life stage.
    Species mean chronic value (SMCV) is the geometric mean of the 
results of all acceptable life-cycle and partial life-cycle toxicity 
tests with the species; for a species of fish for which no such result 
is available, the SMCV is the geometric mean of all acceptable early 
life-stage tests.
    Stream design flow is the stream flow that represents critical 
conditions, upstream from the source, for protection of aquatic life, 
human health, or wildlife.
    Threshold effect is an effect of a substance for which there is a 
theoretical or empirically established dose or concentration below 
which the effect does not occur.
    Tier I criteria are numeric values derived by use of the Tier I 
methodologies in appendixes A, C and D of this part, the methodology in 
appendix B of this part, and the procedures in appendix F of this part, 
that either have been adopted as numeric criteria into a water quality 
standard or are used to implement narrative water quality criteria.
    Tier II values are numeric values derived by use of the Tier II 
methodologies in appendixes A and C of this part, the methodology in 
appendix B of this part, and the procedures in appendix F of this part, 
that are used to implement narrative water quality criteria.
    Total maximum daily load (TMDL) is the sum of the individual 
wasteload allocations for point sources and load allocations for 
nonpoint sources and natural background, as more fully defined at 40 
CFR 130.2(i). A TMDL sets and allocates the maximum amount of a 
pollutant that may be introduced into a water body and still assure 
attainment and maintenance of water quality standards.
    Tributaries of the Great Lakes System means all waters of the Great 
Lakes System that are not open waters of the Great Lakes, or connecting 
channels.
    Uncertainty factor (UF) is one of several numeric factors used in 
operationally deriving criteria from experimental data to account for 
the quality or quantity of the available data.
    Uptake is acquisition of a substance from the environment by an 
organism as a result of any active or passive process.
    Wasteload allocation (WLA) is the portion of a receiving water's 
loading capacity that is allocated to one of its existing or future 
point sources of pollution, as more fully defined at 40 CFR 130.2(h). 
In the absence of a TMDL approved by EPA pursuant to 40 CFR 130.7 or an 
assessment and remediation plan developed and approved in accordance 
with procedure 3.A of appendix F of this part, a WLA is the allocation 
for an individual point source, that ensures that the level of water 
quality to be achieved by the point source is derived from and complies 
with all applicable water quality standards.
    Wet weather point source means any discernible, confined and 
discrete conveyance from which pollutants are, or may be, discharged as 
the result of a wet weather event. Discharges from wet weather point 
sources shall include only: discharges of storm water from a municipal 
separate storm sewer as defined at 40 CFR 122.26(b)(8); storm water 
discharge associated with industrial activity as defined at 40 CFR 
122.26(b)(14); discharges of storm water and sanitary wastewaters 
(domestic, [[Page 15390]] commercial, and industrial) from a combined 
sewer overflow; or any other stormwater discharge for which a permit is 
required under section 402(p) of the Clean Water Act. A storm water 
discharge associated with industrial activity which is mixed with 
process wastewater shall not be considered a wet weather point source.


Sec. 132.3   Adoption of criteria.

    The Great Lakes States and Tribes shall adopt numeric water quality 
criteria for the purposes of section 303(c) of the Clean Water Act 
applicable to waters of the Great Lakes System in accordance with 
Sec. 132.4(d) that are consistent with:
    (a) The acute water quality criteria for protection of aquatic life 
in Table 1 of this part, or a site-specific modification thereof in 
accordance with procedure 1 of appendix F of this part;
    (b) The chronic water quality criteria for protection of aquatic 
life in Table 2 of this part, or a site-specific modification thereof 
in accordance with procedure 1 of appendix F of this part;
    (c) The water quality criteria for protection of human health in 
Table 3 of this part, or a site-specific modification thereof in 
accordance with procedure 1 of appendix F of this part; and
    (d) The water quality criteria for protection of wildlife in Table 
4 of this part, or a site-specific modification thereof in accordance 
with procedure 1 of appendix F of this part.


Sec. 132.4  State adoption and application of methodologies, policies 
and procedures.

    (a) The Great Lakes States and Tribes shall adopt requirements 
applicable to waters of the Great Lakes System for the purposes of 
sections 118, 301, 303, and 402 of the Clean Water Act that are 
consistent with:
    (1) The definitions in Sec. 132.2;
    (2) The Methodologies for Development of Aquatic Life Criteria and 
Values in appendix A of this part;
    (3) The Methodology for Development of Bioaccumulation Factors in 
appendix B of this part;
    (4) The Methodologies for Development of Human Health Criteria and 
Values in appendix C of this part;
    (5) The Methodology for Development of Wildlife Criteria in 
appendix D of this part;
    (6) The Antidegradation Policy in appendix E of this part; and
    (7) The Implementation Procedures in appendix F of this part.
    (b) Except as provided in paragraphs (g), (h), and (i) of this 
section, the Great Lakes States and Tribes shall use methodologies 
consistent with the methodologies designated as Tier I methodologies in 
appendixes A, C, and D of this part, the methodology in appendix B of 
this part, and the procedures in appendix F of this part when adopting 
or revising numeric water quality criteria for the purposes of section 
303(c) of the Clean Water Act for the Great Lakes System.
    (c) Except as provided in paragraphs (g), (h), and (i) of this 
section, the Great Lakes States and Tribes shall use methodologies and 
procedures consistent with the methodologies designated as Tier I 
methodologies in appendixes A, C, and D of this part, the Tier II 
methodologies in appendixes A and C of this part, the methodology in 
appendix B of this part, and the procedures in appendix F of this part 
to develop numeric criteria and values when implementing narrative 
water quality criteria adopted for purposes of section 303(c) of the 
Clean Water Act.
    (d) The water quality criteria and values adopted or developed 
pursuant to paragraphs (a) through (c) of this section shall apply as 
follows:
    (1) The acute water quality criteria and values for the protection 
of aquatic life, or site-specific modifications thereof, shall apply to 
all waters of the Great Lakes System.
    (2) The chronic water quality criteria and values for the 
protection of aquatic life, or site-specific modifications thereof, 
shall apply to all waters of the Great Lakes System.
    (3) The water quality criteria and values for protection of human 
health, or site-specific modifications thereof, shall apply as follows:
    (i) Criteria and values derived as HCV-Drinking and HNV-Drinking 
shall apply to the Open Waters of the Great Lakes, all connecting 
channels of the Great Lakes, and all other waters of the Great Lakes 
System that have been designated as public water supplies by any State 
or Tribe in accordance with 40 CFR 131.10.
    (ii) Criteria and values derived as HCV-Nondrinking and HNV-
Nondrinking shall apply to all waters of the Great Lakes System other 
than those in paragraph (d)(3)(i) of this section.
    (4) Criteria for protection of wildlife, or site-specific 
modifications thereof, shall apply to all waters of the Great Lakes 
System.
    (e) The Great Lakes States and Tribes shall apply implementation 
procedures consistent with the procedures in appendix F of this part 
for all applicable purposes under the Clean Water Act, including 
developing total maximum daily loads for the purposes of section 303(d) 
and water quality-based effluent limits for the purposes of section 
402, in establishing controls on the discharge of any pollutant to the 
Great Lakes System by any point source with the following exceptions:
    (1) The Great Lakes States and Tribes are not required to apply 
these implementation procedures in establishing controls on the 
discharge of any pollutant by a wet weather point source. Any adopted 
implementation procedures shall conform with all applicable Federal, 
State and Tribal requirements.
    (2) The Great Lakes States and Tribes may, but are not required to, 
apply procedures consistent with procedures 1, 2, 3, 4, 5, 7, 8, and 9 
of appendix F of this part in establishing controls on the discharge of 
any pollutant set forth in Table 5 of this part. Any procedures applied 
in lieu of these implementation procedures shall conform with all 
applicable Federal, State, and Tribal requirements.
    (f) The Great Lakes States and Tribes shall apply an 
antidegradation policy consistent with the policy in appendix E for all 
applicable purposes under the Clean Water Act, including 40 CFR 131.12.
    (g) For pollutants listed in Table 5 of this part, the Great Lakes 
States and Tribes shall:
    (1) Apply any methodologies and procedures acceptable under 40 CFR 
part 131 when developing water quality criteria or implementing 
narrative criteria; and
    (2) Apply the implementation procedures in appendix F of this part 
or alternative procedures consistent with all applicable Federal, 
State, and Tribal laws.
    (h) For any pollutant other than those in Table 5 of this part for 
which the State or Tribe demonstrates that a methodology or procedure 
in this part is not scientifically defensible, the Great Lakes States 
and Tribes shall:
    (1) Apply an alternative methodology or procedure acceptable under 
40 CFR part 131 when developing water quality criteria; or
    (2) Apply an alternative implementation procedure that is 
consistent with all applicable Federal, State, and Tribal laws.
    (i) Nothing in this part shall prohibit the Great Lakes States and 
Tribes from adopting numeric water quality criteria, narrative 
criteria, or water quality values that are more stringent than criteria 
or values specified in Sec. 132.3 or that would be derived from 
application of the methodologies set forth in appendixes A, B, C, and D 
of this part, or to adopt antidegradation standards and implementation 
procedures more [[Page 15391]] stringent than those set forth in 
appendixes E and F of this part.


Sec. 132.5  Procedures for adoption and EPA review.

    (a) Except as provided in paragraph (c) of this section, the Great 
Lakes States and Tribes shall adopt and submit for EPA review and 
approval the criteria, methodologies, policies, and procedures 
developed pursuant to this part no later than September 23, 1996.
    (b) The following elements must be included in each submission to 
EPA for review:
    (1) The criteria, methodologies, policies, and procedures developed 
pursuant to this part;
    (2) Certification by the Attorney General or other appropriate 
legal authority pursuant to 40 CFR 123.62 and 40 CFR 131.6(e) as 
appropriate;
    (3) All other information required for submission of National 
Pollutant Discharge Elimination System (NPDES) program modifications 
under 40 CFR 123.62; and
    (4) General information which will aid EPA in determining whether 
the criteria, methodologies, policies and procedures are consistent 
with the requirements of the Clean Water Act and this part, as well as 
information on general policies which may affect their application and 
implementation.
    (c) The Regional Administrator may extend the deadline for the 
submission required in paragraph (a) of this section if the Regional 
Administrator believes that the submission will be consistent with the 
requirements of this part and can be reviewed and approved pursuant to 
this section no later than March 23, 1997.
    (d) If a Great Lakes State or Tribe makes no submission pursuant to 
this part to EPA for review, the requirements of this part shall apply 
to discharges to waters of the Great Lakes System located within the 
State or Federal Indian reservation upon EPA's publication of a final 
rule indicating the effective date of the part 132 requirements in the 
identified jurisdictions.
    (e) If a Great Lakes State or Tribe submits criteria, 
methodologies, policies, and procedures pursuant to this part to EPA 
for review that contain substantial modifications of the State or 
Tribal NPDES program, EPA shall issue public notice and provide a 
minimum of 30 days for public comment on such modifications. The public 
notice shall conform with the requirements of 40 CFR 123.62.
    (f) After review of State or Tribal submissions under this section, 
and following the public comment period in subparagraph (e) of this 
section, if any, EPA shall either:
    (1) Publish notice of approval of the submission in the Federal 
Register within 90 days of such submission; or
    (2) Notify the State or Tribe within 90 days of such submission 
that EPA has determined that all or part of the submission is 
inconsistent with the requirements of the Clean Water Act or this part 
and identify any necessary changes to obtain EPA approval. If the State 
or Tribe fails to adopt such changes within 90 days after the 
notification, EPA shall publish a notice in the Federal Register 
identifying the approved and disapproved elements of the submission and 
a final rule in the Federal Register identifying the provisions of part 
132 that shall apply to discharges within the State or Federal Indian 
reservation.
    (g) EPA's approval or disapproval of a State or Tribal submission 
shall be based on the requirements of this part and of the Clean Water 
Act. EPA's determination whether the criteria, methodologies, policies, 
and procedures in a State or Tribal submission are consistent with the 
requirements of this part will be based on whether:
    (1) For pollutants listed in Tables 1, 2, 3, and 4 of this part. 
The Great Lakes State or Tribe has adopted numeric water quality 
criteria as protective as each of the numeric criteria in Tables 1, 2, 
3, and 4 of this part, taking into account any site-specific criteria 
modifications in accordance with procedure 1 of appendix F of this 
part;
    (2) For pollutants other than those listed in Tables 1, 2, 3, 4, 
and 5 of this part. The Great Lakes State or Tribe demonstrates that 
either:
    (i) It has adopted numeric criteria in its water quality standards 
that were derived, or are as protective as or more protective than 
could be derived, using the methodologies in appendixes A, B, C, and D 
of this part, and the site-specific criteria modification procedures in 
accordance with procedure 1 of appendix F of this part; or
    (ii) It has adopted a procedure by which water quality-based 
effluent limits and total maximum daily loads are developed using the 
more protective of:
    (A) Numeric criteria adopted by the State into State water quality 
standards and approved by EPA prior to March 23, 1997; or
    (B) Water quality criteria and values derived pursuant to 
Sec. 132.4(c); and
    (3) For methodologies, policies, and procedures. The Great Lakes 
State or Tribe has adopted methodologies, policies, and procedures as 
protective as the corresponding methodology, policy, or procedure in 
Sec. 132.4. The Great Lakes State or Tribe may adopt provisions that 
are more protective than those contained in this part. Adoption of a 
more protective element in one provision may be used to offset a less 
protective element in the same provision as long as the adopted 
provision is as protective as the corresponding provision in this part; 
adoption of a more protective element in one provision, however, is not 
justification for adoption of a less protective element in another 
provision of this part.
    (h) A submission by a Great Lakes State or Tribe will need to 
include any provisions that EPA determines, based on EPA's authorities 
under the Clean Water Act and the results of consultation under section 
7 of the Endangered Species Act, are necessary to ensure that water 
quality is not likely to jeopardize the continued existence of any 
endangered or threatened species listed under section 4 of the 
Endangered Species Act or result in the destruction or adverse 
modification of such species' critical habitat.
    (i) EPA's approval of the elements of a State's or Tribe's 
submission will constitute approval under section 118 of the Clean 
Water Act, approval of the submitted water quality standards pursuant 
to section 303 of the Clean Water Act, and approval of the submitted 
modifications to the State's or Tribe's NPDES program pursuant to 
section 402 of the Clean Water Act.


Sec. 132.6  Application of part 132 requirements in Great Lakes States 
and Tribes. [Reserved]

Tables to Part 132

Table 1.--Acute Water Quality Criteria for Protection of Aquatic Life 
in Ambient Water

    EPA recommends that metals criteria be expressed as dissolved 
concentrations (see appendix A, I.A.4 for more information regarding 
metals criteria).
    (a)

------------------------------------------------------------------------
                                                              Conversion
                  Chemical                   CMC(g/    factor  
                                                    L)           (CF)   
------------------------------------------------------------------------
Arsenic (III)..............................     a,b339.8          1.000 
Chromium (VI)..............................      a,b16.02         0.982 
Cyanide....................................        c22              n/a 
Dieldrin...................................         d0.24           n/a 
Endrin.....................................         d0.086          n/a 
Lindane....................................         d0.95           n/a 
Mercury (II)...............................       a,b1.694        0.85  
Parathion..................................         d0.065          n/a 
Selenium...................................      a,b19.34         0.922 
------------------------------------------------------------------------
aCMC=CMCtr.                                                             
bCMCd=(CMCtr) CF. The CMCd shall be rounded to two significant digits.  
[[Page 15392]]                                                          
                                                                        
cCMC should be considered free cyanide as CN.                           
dCMC=CMCt.                                                              
                                                                        
Notes:                                                                  
The term ``n/a'' means not applicable.                                  
CMC is Criterion Maximum Concentration.                                 
CMCtr is the CMC expressed as total recoverable.                        
CMCd is the CMC expressed as a dissolved concentration.                 
CMCt is the CMC expressed as a total concentration.                     

    (b)

------------------------------------------------------------------------
                                                              Conversion
               Chemical                     mA         bA       factor  
                                                                 (CF)   
------------------------------------------------------------------------
Cadmiuma,b............................     1.128     -3.6867      0.85  
Chromium (III)a,b.....................     0.819     +3.7256      0.316 
Coppera,b.............................     0.9422    -1.700       0.960 
Nickela,b.............................     0.846     +2.255       0.998 
Pentachlorophenolc....................     1.005     -4.869         n/a 
Zinca,b...............................     0.8473    +0.884       0.978 
------------------------------------------------------------------------
aCMCtr=exp { mA [ln (hardness)]+bA}.                                    
bCMCd=(CMCtr) CF. The CMCd shall be rounded to two significant digits.  
cCMCt=exp mA { [pH]+bA}. The CMCt shall be rounded to two significant   
  digits.                                                               
                                                                        
Notes:                                                                  
The term ``exp'' represents the base e exponential function.            
The term ``n/a'' means not applicable.                                  
CMC is Criterion Maximum Concentration.                                 
CMCtr is the CMC expressed as total recoverable.                        
CMCd is the CMC expressed as a dissolved concentration.                 
CMCt is the CMC expressed as a total concentration.                     

Table 2.--Chronic Water Quality Criteria for Protection of Aquatic Life 
in Ambient Water

    EPA recommends that metals criteria be expressed as dissolved 
concentrations (see appendix A, I.A.4 for more information regarding 
metals criteria).
    (a)

------------------------------------------------------------------------
                                                              Conversion
                  Chemical                   CCC(g/    factor  
                                                    L)           (CF)   
------------------------------------------------------------------------
Arsenic (III)..............................    a,b147.9           1.000 
Chromium (VI)..............................     a,b10.98          0.962 
Cyanide....................................        c5.2             n/a 
Dieldrin...................................        d0.056           n/a 
Endrin.....................................        d0.036           n/a 
Mercury (II)...............................      a,b0.9081        0.85  
Parathion..................................        d0.013           n/a 
Selenium...................................      a,b5             0.922 
------------------------------------------------------------------------
aCCC=CCCtr.                                                             
bCCCd=(CCCtr) CF. The CCCd shall be rounded to two significant digits.  
cCCC should be considered free cyanide as CN.                           
dCCC=CCCt.                                                              
                                                                        
Notes:                                                                  
The term ``n/a'' means not applicable.                                  
CCC is Criterion Continuous Concentration.                              
CCCtr is the CCC expressed as total recoverable.                        
CCCd is the CCC expressed as a dissolved concentration.                 
CCCt is the CCC expressed as a total concentration.                     

    (b)

------------------------------------------------------------------------
                                                              Conversion
                 Chemical                      mc       bc    factor(CF)
------------------------------------------------------------------------
Cadmiuma,b................................   0.7852  -2.715       0.850 
Chromium (III)a,b.........................   0.819   +0.6848      0.860 
Coppera,b.................................   0.8545  -1.702       0.960 
Nickela,b.................................   0.846   +0.0584      0.997 
Pentachlorophenolc........................   1.005   -5.134         n/a 
Zinca,b...................................   0.8473  +0.884       0.986 
------------------------------------------------------------------------
aCCCtr=exp {mc[ln (hardness)]+bc}.                                      
bCCCd=(CCCtr) (CF). The CCCd shall be rounded to two significant digits.
cCMCt=exp {mA[pH]+bA}. The CMCt shall be rounded to two significant     
  digits.                                                               
                                                                        
Notes:                                                                  
The term ``exp'' represents the base e exponential function.            
The term ``n/a'' means not applicable.                                  
CCC is Criterion Continuous Concentration.                              
CCCtr is the CCC expressed as total recoverable.                        
CCCd is the CCC expressed as a dissolved concentration.                 
CCCt is the CCC expressed as a total concentration.                     


                         Table 3.--Water Quality Criteria for Protection of Human Health                        
----------------------------------------------------------------------------------------------------------------
                                                           HNV (g/L)            HCV (g/L)     
                      Chemical                       -----------------------------------------------------------
                                                         Drinking     Nondrinking      Drinking     Nondrinking 
----------------------------------------------------------------------------------------------------------------
Benzene.............................................  1.9E1          5.1E2          1.2E1          3.1E2        
Chlordane...........................................  1.4E-3         1.4E-3         2.5E-4         2.5E-4       
Chlorobenzene.......................................  4.7E2          3.2E3                                      
Cyanides............................................  6.0E2          4.8E4                                      
DDT.................................................  2.0E-3         2.0E-3         1.5E-4         1.5E-4       
Dieldrin............................................  4.1E-4         4.1E-4         6.5E-6         6.5E-6       
2,4-Dimethylphenol..................................  4.5E2          8.7E3                                      
2,4-Dinitrophenol...................................  5.5E1          2.8E3                                      
Hexachlorobenzene...................................  4.6E-2         4.6E-2         4.5E-4         4.5E-4       
Hexachloroethane....................................  6.0            7.6            5.3            6.7          
Lindane.............................................  4.7E-1         5.0E-1                                     
Mercury1............................................  1.8E-3         1.8E-3                                     
Methylene chloride..................................  1.6E3          9.0E4          4.7E1          2.6E3        
PCBs (class)........................................                                3.9E-6         3.9E-6       
2,3,7,8-TCDD........................................  6.7E-8         6.7E-8         8.6E-9         8.6E-9       
Toluene.............................................  5.6E3          5.1E4                                      
Toxaphene...........................................                                6.8E-5         6.8E-5       
[[Page 15393]]                                                                                                  
                                                                                                                
Trichloroethylene...................................                                2.9E1          3.7E2        
----------------------------------------------------------------------------------------------------------------
\1\Includes methylmercury.                                                                                      


       Table 4.--Water Quality Criteria for Protection of Wildlife      
------------------------------------------------------------------------
                                                              Criteria  
                         Chemical                           (g/
                                                                 L)     
------------------------------------------------------------------------
DDT and metabolites.......................................  1.1E-5      
Mercury (including methylmercury).........................  1.3E-3      
PCBs (class)..............................................  7.4E-5      
2,3,7,8-TCDD..............................................  3.1E-9      
------------------------------------------------------------------------

Table 5.--Pollutants Subject to Federal, State, and Tribal Requirements

    Alkalinity
    Ammonia
    Bacteria
    Biochemical oxygen demand (BOD)
    Chlorine
    Color
    Dissolved oxygen
    Dissolved solids
    pH
    Phosphorus
    Salinity
    Temperature
    Total and suspended solids
    Turbidity

Table 6.--Pollutants of Initial Focus in the Great Lakes Water Quality 
Initiative

    A. Pollutants that are bioaccumulative chemicals of concern 
(BCCs):
    Chlordane
    4,4'-DDD; p,p'-DDD; 4,4'-TDE; p,p'-TDE
    4,4'-DDE; p,p'-DDE
    4,4'-DDT; p,p'-DDT
    Dieldrin
    Hexachlorobenzene
    Hexachlorobutadiene; hexachloro-1, 3-butadiene
    Hexachlorocyclohexanes; BHCs
    alpha-Hexachlorocyclohexane; alpha-BHC
    beta-Hexachlorocyclohexane; beta-BHC
    delta-Hexachlorocyclohexane; delta-BHC
    Lindane; gamma-hexachlorocyclohexane; gamma-BHC
    Mercury
    Mirex
    Octachlorostyrene
    PCBs; polychlorinated biphenyls
    Pentachlorobenzene
    Photomirex
    2,3,7,8-TCDD; dioxin
    1,2,3,4-Tetrachlorobenzene
    1,2,4,5-Tetrachlorobenzene Toxaphene
    B. Pollutants that are not bioaccumulative chemicals of concern:
    Acenaphthene
    Acenaphthylene
    Acrolein; 2-propenal
    Acrylonitrile
    Aldrin
    Aluminum
    Anthracene
    Antimony
    Arsenic
    Asbestos
    1,2-Benzanthracene; benz[a]anthracene
    Benzene
    Benzidine
    Benzo[a]pyrene; 3,4-benzopyrene
    3,4-Benzofluoranthene; benzo[b]fluoranthene
    11,12-Benzofluoranthene; benzo[k]fluoranthene
    1,12-Benzoperylene; benzo[ghi]perylene
    Beryllium
    Bis(2-chloroethoxy) methane
    Bis(2-chloroethyl) ether
    Bis(2-chloroisopropyl) ether
    Bromoform; tribomomethane
    4-Bromophenyl phenyl ether
    Butyl benzyl phthalate
    Cadmium
    Carbon tetrachloride; tetrachloromethane
    Chlorobenzene
    p-Chloro-m-cresol; 4-chloro-3-methylphenol
    Chlorodibromomethane
    Chlorethane
    2-Chloroethyl vinyl ether
    Chloroform; trichloromethane
    2-Chloronaphthalene
    2-Chlorophenol
    4-Chlorophenyl phenyl ether
    Chlorpyrifos
    Chromium
    Chrysene
    Copper
    Cyanide
    2,4-D; 2,4-Dichlorophenoxyacetic acid
    DEHP; di(2-ethylhexyl) phthalate
    Diazinon
    1,2:5,6-Dibenzanthracene; dibenz[a,h]anthracene
    Dibutyl phthalate; di-n-butyl phthalate
    1,2-Dichlorobenzene
    1,3-Dichlorobenzene
    1,4-Dichlorobenzene
    3,3'-Dichlorobenzidine
    Dichlorobromomethane; bromodichloromethane
    1,1-Dichloroethane
    1,2-Dichloroethane
    1,1-Dichloroethylene; vinylidene chloride
    1,2-trans-Dichloroethylene
    2,4-Dichlorophenol
    1,2-Dichloropropane
    1,3-Dichloropropene; 1,3-dichloropropylene
    Diethyl phthalate
    2,4-Dimethylphenol; 2,4-xylenol
    Dimethyl phthalate
    4,6-Dinitro-o-cresol; 2-methyl-4,6-dinitrophenol
    2,4-Dinitrophenol
    2,4-Dinitrotoluene
    2,6-Dinitrotoluene
    Dioctyl phthalate; di-n-octyl phthalate
    1,2-Diphenylhydrazine
    Endosulfan; thiodan
    alpha-Endosulfan
    beta-Endosulfan
    Endosulfan sulfate
    Endrin
    Endrin aldehyde
    Ethylbenzene
    Fluoranthene
    Fluorene; 9H-fluorene
    Fluoride
    Guthion
    Heptachlor
    Heptachlor epoxide
    Hexachlorocyclopentadiene
    Hexachloroethane
    Indeno[1,2,3-cd]pyrene; 2,3-o-phenylene pyrene
    Isophorone
    Lead
    Malathion
    Methoxychlor
    Methyl bromide; bromomethane
    Methyl chloride; chloromethane
    Methylene chloride; dichloromethane
    Napthalene
    Nickel
    Nitrobenzene
    2-Nitrophenol
    4-Nitrophenol
    N-Nitrosodimethylamine
    N-Nitrosodiphenylamine
    N-Nitrosodipropylamine; N-nitrosodi-n-propylamine
    Parathion
    Pentachlorophenol
    Phenanthrene
    Phenol
    Iron
    Pyrene
    Selenium
    Silver
    1,1,2,2-Tetrachloroethane
    Tetrachloroethylene
    Thallium
    Toluene; methylbenzene
    1,2,4-Trichlorobenzene
    1,1,1-Trichloroethane
    1,1,2-Trichloroethane
    Trichloroethylene; trichloroethene
    2,4,6-Trichlorophenol
    Vinyl chloride; chloroethylene; chloroethene
    Zinc

Appendix A to part 132--Great Lakes Water Quality Initiative 
Methodologies for Developments of Aquatic Life Criteria and Values

Methodology for Deriving Aquatic Life Criteria: Tier I

    Great Lakes States and Tribes shall adopt provisions consistent 
with (as protective as) this appendix. [[Page 15394]] 

I. Definitions

    A. Material of Concern. When defining the material of concern 
the following should be considered:
    1. Each separate chemical that does not ionize substantially in 
most natural bodies of water should usually be considered a separate 
material, except possibly for structurally similar organic compounds 
that only exist in large quantities as commercial mixtures of the 
various compounds and apparently have similar biological, chemical, 
physical, and toxicological properties.
    2. For chemicals that ionize substantially in most natural 
bodies of water (e.g., some phenols and organic acids, some salts of 
phenols and organic acids, and most inorganic salts and coordination 
complexes of metals and metalloid), all forms that would be in 
chemical equilibrium should usually be considered one material. Each 
different oxidation state of a metal and each different non-
ionizable covalently bonded organometallic compound should usually 
be considered a separate material.
    3. The definition of the material of concern should include an 
operational analytical component. Identification of a material 
simply as ``sodium,'' for example, implies ``total sodium,'' but 
leaves room for doubt. If ``total'' is meant, it must be explicitly 
stated. Even ``total'' has different operational definitions, some 
of which do not necessarily measure ``all that is there'' in all 
samples. Thus, it is also necessary to reference or describe the 
analytical method that is intended. The selection of the operational 
analytical component should take into account the analytical and 
environmental chemistry of the material and various practical 
considerations, such as labor and equipment requirements, and 
whether the method would require measurement in the field or would 
allow measurement after samples are transported to a laboratory.
    a. The primary requirements of the operational analytical 
component are that it be appropriate for use on samples of receiving 
water, that it be compatible with the available toxicity and 
bioaccumulation data without making extrapolations that are too 
hypothetical, and that it rarely result in underprotection or 
overprotection of aquatic organisms and their uses. Toxicity is the 
property of a material, or combination of materials, to adversely 
affect organisms.
    b. Because an ideal analytical measurement will rarely be 
available, an appropriate compromise measurement will usually have 
to be used. This compromise measurement must fit with the general 
approach that if an ambient concentration is lower than the 
criterion, unacceptable effects will probably not occur, i.e., the 
compromise measure must not err on the side of underprotection when 
measurements are made on a surface water. What is an appropriate 
measurement in one situation might not be appropriate for another. 
For example, because the chemical and physical properties of an 
effluent are usually quite different from those of the receiving 
water, an analytical method that is appropriate for analyzing an 
effluent might not be appropriate for expressing a criterion, and 
vice versa. A criterion should be based on an appropriate analytical 
measurement, but the criterion is not rendered useless if an ideal 
measurement either is not available or is not feasible.
    Note: The analytical chemistry of the material might have to be 
taken into account when defining the material or when judging the 
acceptability of some toxicity tests, but a criterion must not be 
based on the sensitivity of an analytical method. When aquatic 
organisms are more sensitive than routine analytical methods, the 
proper solution is to develop better analytical methods.
    4. It is now the policy of EPA that the use of dissolved metal 
to set and measure compliance with water quality standards is the 
recommended approach, because dissolved metal more closely 
approximates the bioavailable fraction of metal in the water column 
that does total recoverable metal. One reason is that a primary 
mechanism for water column toxicity is adsorption at the gill 
surface which requires metals to be in the dissolved form. Reasons 
for the consideration of total recoverable metals criteria include 
risk management considerations not covered by evaluation of water 
column toxicity. A risk manager may consider sediments and food 
chain effects and may decide to take a conservative approach for 
metals, considering that metals are very persistent chemicals. This 
approach could include the use of total recoverable metal in water 
quality standards. A range of different risk management decisions 
can be justified. EPA recommends that State water quality standards 
be based on dissolved metal. EPA will also approve a State risk 
management decision to adopt standards based on total recoverable 
metal, if those standards are otherwise approvable under this 
program.
    B. Acute Toxicity. Concurrent and delayed adverse effect(s) that 
results from an acute exposure and occurs within any short 
observation period which begins when the exposure begins, may extend 
beyond the exposure period, and usually does not constitute a 
substantial portion of the life span of the organism. (Concurrent 
toxicity is an adverse effect to an organism that results from, and 
occurs during, its exposure to one or more test materials.) Exposure 
constitutes contact with a chemical or physical agent. Acute 
exposure, however, is exposure of an organism for any short period 
which usually does not constitute a substantial portion of its life 
span.
    C. Chronic Toxicity. Concurrent and delayed adverse effect(s) 
that occurs only as a result of a chronic exposure. Chronic exposure 
is exposure of an organism for any long period or for a substantial 
portion of its life span.

II. Collection of Data

    A. Collect all data available on the material concerning 
toxicity to aquatic animals and plants.
    B. All data that are used should be available in typed, dated, 
and signed hard copy (e.g., publication, manuscript, letter, 
memorandum, etc.) with enough supporting information to indicate 
that acceptable test procedures were used and that the results are 
reliable. In some cases, it might be appropriate to obtain written 
information from the investigator, if possible. Information that is 
not available for distribution shall not be used.
    C. Questionable data, whether published or unpublished, must not 
be used. For example, data must be rejected if they are from tests 
that did not contain a control treatment, tests in which too many 
organisms in the control treatment died or showed signs of stress or 
disease, and tests in which distilled or deionized water was used as 
the dilution water without the addition of appropriate salts.
    D. Data on technical grade materials may be used if appropriate, 
but data on formulated mixtures and emulsifiable concentrates of the 
material must not be used.
    E. For some highly volatile, hydrolyzable, or degradable 
materials, it might be appropriate to use only results of flow-
through tests in which the concentrations of test material in test 
solutions were measured using acceptable analytical methods. A flow-
through test is a test with aquatic organisms in which test 
solutions flow into constant-volume test chambers either 
intermittently (e.g., every few minutes) or continuously, with the 
excess flowing out.
    F. Data must be rejected if obtained using:
    1. Brine shrimp, because they usually only occur naturally in 
water with salinity greater than 35 g/kg.
    2. Species that do not have reproducing wild populations in 
North America.
    3. Organisms that were previously exposed to substantial 
concentrations of the test material or other contaminants.
    4. Saltwater species except for use in deriving acute-chronic 
ratios. An ACR is a standard measure of the acute toxicity of a 
material divided by an appropriate measure of the chronic toxicity 
of the same material under comparable conditions.
    G. Questionable data, data on formulated mixtures and 
emulsifiable concentrates, and data obtained with species non-
resident to North America or previously exposed organisms may be 
used to provide auxiliary information but must not be used in the 
derivation of criteria.

III. Required Data

    A. Certain data should be available to help ensure that each of 
the major kinds of possible adverse effects receives adequate 
consideration. An adverse effect is a change in an organism that is 
harmful to the organism. Exposure means contact with a chemical or 
physical agent. Results of acute and chronic toxicity tests with 
representative species of aquatic animals are necessary so that data 
available for tested species can be considered a useful indication 
of the sensitivities of appropriate untested species. Fewer data 
concerning toxicity to aquatic plants are usually available because 
procedures for conducting tests with plants and interpreting the 
results of such tests are not as well developed.
    B. To derive a Great Lakes Tier I criterion for aquatic 
organisms and their uses, the following must be available:
    1. Results of acceptable acute (or chronic) tests (see section 
IV or VI of this appendix) with at least one species of freshwater 
animal in at least eight different families such that all of the 
following are included: [[Page 15395]] 
    a. The family Salmonidae in the class Osteichthyes;
    b. One other family (preferably a commercially or recreationally 
important, warmwater species) in the class Osteichthyes (e.g., 
bluegill, channel catfish);
    c. A third family in the phylum Chordata (e.g., fish, 
amphibian);
    d. A planktonic crustacean (e.g., a cladoceran, copepod);
    e. A benthic crustacean (e.g., ostracod, isopod, amphipod, 
crayfish);
    f. An insect (e.g., mayfly, dragonfly, damselfly, stonefly, 
caddisfly, mosquito, midge);
    g. A family in a phylum other than Arthropoda or Chordata (e.g., 
Rotifera, Annelida, Mollusca);
    h. A family in any order of insect or any phylum not already 
represented.
    2. Acute-chronic ratios (see section VI of this appendix) with 
at least one species of aquatic animal in at least three different 
families provided that of the three species:
    a. At least one is a fish;
    b. At least one is an invertebrate; and
    c. At least one species is an acutely sensitive freshwater 
species (the other two may be saltwater species).
    3. Results of at least one acceptable test with a freshwater 
algae or vascular plant is desirable but not required for criterion 
derivation (see section VIII of this appendix). If plants are among 
the aquatic organisms most sensitive to the material, results of a 
test with a plant in another phylum (division) should also be 
available.
    C. If all required data are available, a numerical criterion can 
usually be derived except in special cases. For example, derivation 
of a chronic criterion might not be possible if the available ACRs 
vary by more than a factor of ten with no apparent pattern. Also, if 
a criterion is to be related to a water quality characteristic (see 
sections V and VII of this appendix), more data will be required.
    D. Confidence in a criterion usually increases as the amount of 
available pertinent information increases. Thus, additional data are 
usually desirable.

IV. Final Acute Value

    A. Appropriate measures of the acute (short-term) toxicity of 
the material to a variety of species of aquatic animals are used to 
calculate the Final Acute Value (FAV). The calculated Final Acute 
Value is a calculated estimate of the concentration of a test 
material such that 95 percent of the genera (with which acceptable 
acute toxicity tests have been conducted on the material) have 
higher Genus Mean Acute Values (GMAVs). An acute test is a 
comparative study in which organisms, that are subjected to 
different treatments, are observed for a short period usually not 
constituting a substantial portion of their life span. However, in 
some cases, the Species Mean Acute Value (SMAV) of a commercially or 
recreationally important species of the Great Lakes System is lower 
than the calculated FAV, then the SMAV replaces the calculated FAV 
in order to provide protection for that important species.
    B. Acute toxicity tests shall be conducted using acceptable 
procedures. For good examples of acceptable procedures see American 
Society for Testing and Materials (ASTM) Standard E 729, Guide for 
Conducting Acute Toxicity Tests with Fishes, Macroinvertebrates, and 
Amphibians.
    C. Except for results with saltwater annelids and mysids, 
results of acute tests during which the test organisms were fed 
should not be used, unless data indicate that the food did not 
affect the toxicity of the test material. (Note: If the minimum 
acute-chronic ratio data requirements (as described in section 
III.B.2 of this appendix) are not met with freshwater data alone, 
saltwater data may be used.)
    D. Results of acute tests conducted in unusual dilution water, 
e.g., dilution water in which total organic carbon or particulate 
matter exceeded five mg/L, should not be used, unless a relationship 
is developed between acute toxicity and organic carbon or 
particulate matter, or unless data show that organic carbon or 
particulate matter, etc., do not affect toxicity.
    E. Acute values must be based upon endpoints which reflect the 
total severe adverse impact of the test material on the organisms 
used in the test. Therefore, only the following kinds of data on 
acute toxicity to aquatic animals shall be used:
    1. Tests with daphnids and other cladocerans must be started 
with organisms less than 24 hours old and tests with midges must be 
started with second or third instar larvae. It is preferred that the 
results should be the 48-hour EC50 based on the total percentage of 
organisms killed and immobilized. If such an EC50 is not available 
for a test, the 48-hour LC50 should be used in place of the desired 
48-hour EC50. An EC50 or LC50 of longer than 48 hours can be used as 
long as the animals were not fed and the control animals were 
acceptable at the end of the test. An EC50 is a statistically or 
graphically estimated concentration that is expected to cause one or 
more specified effects in 50% of a group of organisms under 
specified conditions. An LC50 is a statistically or graphically 
estimated concentration that is expected to be lethal to 50% of a 
group of organisms under specified conditions.
    2. It is preferred that the results of a test with embryos and 
larvae of barnacles, bivalve molluscs (clams, mussels, oysters and 
scallops), sea urchins, lobsters, crabs, shrimp and abalones be the 
96-hour EC50 based on the percentage of organisms with incompletely 
developed shells plus the percentage of organisms killed. If such an 
EC50 is not available from a test, of the values that are available 
from the test, the lowest of the following should be used in place 
of the desired 96-hour EC50: 48- to 96-hour EC50s based on 
percentage of organisms with incompletely developed shells plus 
percentage of organisms killed, 48- to 96-hour EC50s based upon 
percentage of organisms with incompletely developed shells, and 48-
hour to 96-hour LC50s. (Note: If the minimum acute-chronic ratio 
data requirements (as described in section III.B.2 of this appendix) 
are not met with freshwater data alone, saltwater data may be used.)
    3. It is preferred that the result of tests with all other 
aquatic animal species and older life stages of barnacles, bivalve 
molluscs (clams, mussels, oysters and scallops), sea urchins, 
lobsters, crabs, shrimp and abalones be the 96-hour EC50 based on 
percentage of organisms exhibiting loss of equilibrium plus 
percentage of organisms immobilized plus percentage of organisms 
killed. If such an EC50 is not available from a test, of the values 
that are available from a test the lower of the following should be 
used in place of the desired 96-hour EC50: the 96-hour EC50 based on 
percentage of organisms exhibiting loss of equilibrium plus 
percentage of organisms immobilized and the 96-hour LC50.
    4. Tests whose results take into account the number of young 
produced, such as most tests with protozoans, are not considered 
acute tests, even if the duration was 96 hours or less.
    5. If the tests were conducted properly, acute values reported 
as ``greater than'' values and those which are above the solubility 
of the test material should be used, because rejection of such acute 
values would bias the Final Acute Value by eliminating acute values 
for resistant species.
    F. If the acute toxicity of the material to aquatic animals has 
been shown to be related to a water quality characteristic such as 
hardness or particulate matter for freshwater animals, refer to 
section V of this appendix.
    G. The agreement of the data within and between species must be 
considered. Acute values that appear to be questionable in 
comparison with other acute and chronic data for the same species 
and for other species in the same genus must not be used. For 
example, if the acute values available for a species or genus differ 
by more than a factor of 10, rejection of some or all of the values 
would be appropriate, absent countervailing circumstances.
    H. If the available data indicate that one or more life stages 
are at least a factor of two more resistant than one or more other 
life stages of the same species, the data for the more resistant 
life stages must not be used in the calculation of the SMAV because 
a species cannot be considered protected from acute toxicity if all 
of the life stages are not protected.
    I. For each species for which at least one acute value is 
available, the SMAV shall be calculated as the geometric mean of the 
results of all acceptable flow-through acute toxicity tests in which 
the concentrations of test material were measured with the most 
sensitive tested life stage of the species. For a species for which 
no such result is available, the SMAV shall be calculated as the 
geometric mean of all acceptable acute toxicity tests with the most 
sensitive tested life stage, i.e., results of flow-through tests in 
which the concentrations were not measured and results of static and 
renewal tests based on initial concentrations (nominal 
concentrations are acceptable for most test materials if measured 
concentrations are not available) of test material. A renewal test 
is a test with aquatic organisms in which either the test solution 
in a test chamber is removed and replaced at least once during the 
test or the test organisms are transferred into a new test solution 
of the same composition at least once during the test. A static test 
is a test with aquatic organisms in which the solution 
[[Page 15396]] and organisms that are in a test chamber at the 
beginning of the test remain in the chamber until the end of the 
test, except for removal of dead test organisms.

    Note 1: Data reported by original investigators must not be 
rounded off. Results of all intermediate calculations must not be 
rounded off to fewer than four significant digits.

    Note 2: The geometric mean of N numbers is the Nth root of the 
product of the N numbers. Alternatively, the geometric mean can be 
calculated by adding the logarithms of the N numbers, dividing the 
sum by N, and taking the antilog of the quotient. The geometric mean 
of two numbers is the square root of the product of the two numbers, 
and the geometric mean of one number is that number. Either natural 
(base e) or common (base 10) logarithms can be used to calculate 
geometric means as long as they are used consistently within each 
set of data, i.e., the antilog used must match the logarithms used.

    Note 3: Geometric means, rather than arithmetic means, are used 
here because the distributions of sensitivities of individual 
organisms in toxicity tests on most materials and the distributions 
of sensitivities of species within a genus are more likely to be 
lognormal than normal. Similarly, geometric means are used for ACRs 
because quotients are likely to be closer to lognormal than normal 
distributions. In addition, division of the geometric mean of a set 
of numerators by the geometric mean of the set of denominators will 
result in the geometric mean of the set of corresponding quotients.

    J. For each genus for which one or more SMAVs are available, the 
GMAV shall be calculated as the geometric mean of the SMAVs 
available for the genus.
    K. Order the GMAVs from high to low.
    L. Assign ranks, R, to the GMAVs from ``1'' for the lowest to 
``N'' for the highest. If two or more GMAVs are identical, assign 
them successive ranks.
    M. Calculate the cumulative probability, P, for each GMAV as R/
(N+1).
    N. Select the four GMAVs which have cumulative probabilities 
closest to 0.05 (if there are fewer than 59 GMAVs, these will always 
be the four lowest GMAVs).
    O. Using the four selected GMAVs, and Ps, calculate
[GRAPHIC][TIFF OMITTED]TR23MR95.104


    Note: Natural logarithms (logarithms to base e, denoted as ln) 
are used herein merely because they are easier to use on some hand 
calculators and computers than common (base 10) logarithms. 
Consistent use of either will produce the same result.

    P. If for a commercially or recreationally important species of 
the Great Lakes System the geometric mean of the acute values from 
flow-through tests in which the concentrations of test material were 
measured is lower than the calculated Final Acute Value (FAV), then 
that geometric mean must be used as the FAV instead of the 
calculated FAV.
    Q. See section VI of this appendix.

V. Final Acute Equation

    A. When enough data are available to show that acute toxicity to 
two or more species is similarly related to a water quality 
characteristic, the relationship shall be taken into account as 
described in sections V.B through V.G of this appendix or using 
analysis of covariance. The two methods are equivalent and produce 
identical results. The manual method described below provides an 
understanding of this application of covariance analysis, but 
computerized versions of covariance analysis are much more 
convenient for analyzing large data sets. If two or more factors 
affect toxicity, multiple regression analysis shall be used.
    B. For each species for which comparable acute toxicity values 
are available at two or more different values of the water quality 
characteristic, perform a least squares regression of the acute 
toxicity values on the corresponding values of the water quality 
characteristic to obtain the slope and its 95 percent confidence 
limits for each species.

    Note: Because the best documented relationship is that between 
hardness and acute toxicity of metals in fresh water and a log-log 
relationship fits these data, geometric means and natural logarithms 
of both toxicity and water quality are used in the rest of this 
section. For relationships based on other water quality 
characteristics, such as Ph, temperature, no transformation or a 
different transformation might fit the data better, and appropriate 
changes will be necessary throughout this section.

    C. Decide whether the data for each species are relevant, taking 
into account the range and number of the tested values of the water 
quality characteristic and the degree of agreement within and 
between species. For example, a slope based on six data points might 
be of limited value if it is based only on data for a very narrow 
range of values of the water quality characteristic. A slope based 
on only two data points, however, might be useful if it is 
consistent with other information and if the two points cover a 
broad enough range of the water quality characteristic. In addition, 
acute values that appear to be questionable in comparison with other 
acute and chronic data available for the same species and for other 
species in the same genus should not be used. For example, if after 
adjustment for the water quality characteristic, the acute values 
available for a species or genus differ by more than a factor of 10, 
rejection of some or all of the values would be appropriate, absent 
countervailing justification. If useful slopes are not available for 
at least one fish and one invertebrate or if the available slopes 
are too dissimilar or if too few data are available to adequately 
define the relationship between acute toxicity and the water quality 
characteristic, return to section IV.G of this appendix, using the 
results of tests conducted under conditions and in waters similar to 
those commonly used for toxicity tests with the species.
    D. For each species, calculate the geometric mean of the 
available acute values and then divide each of the acute values for 
the species by the geometric mean for the species. This normalizes 
the acute values so that the geometric mean of the normalized values 
for each species individually and for any combination of species is 
1.0.
    E. Similarly normalize the values of the water quality 
characteristic for each species individually using the same 
procedure as above.
    F. Individually for each species perform a least squares 
regression of the normalized [[Page 15397]] acute values of the 
water quality characteristic. The resulting slopes and 95 percent 
confidence limits will be identical to those obtained in section 
V.B. of this appendix. If, however, the data are actually plotted, 
the line of best fit for each individual species will go through the 
point 1,1 in the center of the graph.
    G. Treat all of the normalized data as if they were all for the 
same species and perform a least squares regression of all of the 
normalized acute values on the corresponding normalized values of 
the water quality characteristic to obtain the pooled acute slope, 
V, and its 95 percent confidence limits. If all of the normalized 
data are actually plotted, the line of best fit will go through the 
point 1,1 in the center of the graph.
    H. For each species calculate the geometric mean, W, of the 
acute toxicity values and the geometric mean, X, of the values of 
the water quality characteristic. (These were calculated in sections 
V.D and V.E of this appendix).
    I. For each species, calculate the logarithm, Y, of the SMAV at 
a selected value, Z, of the water quality characteristic using the 
equation:

Y=ln W-V(ln X-ln Z)

    J. For each species calculate the SMAV at X using the equation:

SMAV=eY

    Note: Alternatively, the SMAVs at Z can be obtained by skipping 
step H above, using the equations in steps I and J to adjust each 
acute value individually to Z, and then calculating the geometric 
mean of the adjusted values for each species individually. This 
alternative procedure allows an examination of the range of the 
adjusted acute values for each species.

    K. Obtain the FAV at Z by using the procedure described in 
sections IV.J through IV.O of this appendix.
    L. If, for a commercially or recreationally important species of 
the Great Lakes System the geometric mean of the acute values at Z 
from flow-through tests in which the concentrations of the test 
material were measured is lower than the FAV at Z, then the 
geometric mean must be used as the FAV instead of the FAV.
    M. The Final Acute Equation is written as:

FAV=e(V[ln(water quality characteristic)]+A-V[ln Z]),

    where:
V=pooled acute slope, and A=ln(FAV at Z).

    Because V, A, and Z are known, the FAV can be calculated for any 
selected value of the water quality characteristic.

VI. Final Chronic Value

    A. Depending on the data that are available concerning chronic 
toxicity to aquatic animals, the Final Chronic Value (FCV) can be 
calculated in the same manner as the FAV or by dividing the FAV by 
the Final Acute-Chronic Ratio (FACR). In some cases, it might not be 
possible to calculate a FCV. The FCV is (a) a calculated estimate of 
the concentration of a test material such that 95 percent of the 
genera (with which acceptable chronic toxicity tests have been 
conducted on the material) have higher GMCVs, or (b) the quotient of 
an FAV divided by an appropriate ACR, or (c) the SMCV of an 
important and/or critical species, if the SMCV is lower than the 
calculated estimate or the quotient, whichever is applicable.

    Note: As the name implies, the ACR is a way of relating acute 
and chronic toxicities.

    B. Chronic values shall be based on results of flow-through 
(except renewal is acceptable for daphnids) chronic tests in which 
the concentrations of test material in the test solutions were 
properly measured at appropriate times during the test. A chronic 
test is a comparative study in which organisms, that are subjected 
to different treatments, are observed for a long period or a 
substantial portion of their life span.
    C. Results of chronic tests in which survival, growth, or 
reproduction in the control treatment was unacceptably low shall not 
be used. The limits of acceptability will depend on the species.
    D. Results of chronic tests conducted in unusual dilution water, 
e.g., dilution water in which total organic carbon or particulate 
matter exceeded five mg/L, should not be used, unless a relationship 
is developed between chronic toxicity and organic carbon or 
particulate matter, or unless data show that organic carbon, 
particulate matter, etc., do not affect toxicity.
    E. Chronic values must be based on endpoints and lengths of 
exposure appropriate to the species. Therefore, only results of the 
following kinds of chronic toxicity tests shall be used:
    1. Life-cycle toxicity tests consisting of exposures of each of 
two or more groups of individuals of a species to a different 
concentration of the test material throughout a life cycle. To 
ensure that all life stages and life processes are exposed, tests 
with fish should begin with embryos or newly hatched young less than 
48 hours old, continue through maturation and reproduction, and 
should end not less than 24 days (90 days for salmonids) after the 
hatching of the next generation. Tests with daphnids should begin 
with young less than 24 hours old and last for not less than 21 
days, and for ceriodaphnids not less than seven days. For good 
examples of acceptable procedures see American Society for Testing 
and Materials (ASTM) Standard E 1193 Guide for conducting renewal 
life-cycle toxicity tests with Daphnia magna and ASTM Standard E 
1295 Guide for conducting three-brood, renewal toxicity tests with 
Ceriodaphnia dubia. Tests with mysids should begin with young less 
than 24 hours old and continue until seven days past the median time 
of first brood release in the controls. For fish, data should be 
obtained and analyzed on survival and growth of adults and young, 
maturation of males and females, eggs spawned per female, embryo 
viability (salmonids only), and hatchability. For daphnids, data 
should be obtained and analyzed on survival and young per female. 
For mysids, data should be obtained and analyzed on survival, 
growth, and young per female.
    2. Partial life-cycle toxicity tests consist of exposures of 
each of two more groups of individuals of a species of fish to a 
different concentration of the test material through most portions 
of a life cycle. Partial life-cycle tests are allowed with fish 
species that require more than a year to reach sexual maturity, so 
that all major life stages can be exposed to the test material in 
less than 15 months. A life-cycle test is a comparative study in 
which organisms, that are subjected to different treatments, are 
observed at least from a life stage in one generation to the same 
life-stage in the next generation. Exposure to the test material 
should begin with immature juveniles at least two months prior to 
active gonad development, continue through maturation and 
reproduction, and end not less than 24 days (90 days for salmonids) 
after the hatching of the next generation. Data should be obtained 
and analyzed on survival and growth of adults and young, maturation 
of males and females, eggs spawned per female, embryo viability 
(salmonids only), and hatchability.
    3. Early life-stage toxicity tests consisting of 28- to 32-day 
(60 days post hatch for salmonids) exposures of the early life 
stages of a species of fish from shortly after fertilization through 
embryonic, larval, and early juvenile development. Data should be 
obtained and analyzed on survival and growth.
    Note: Results of an early life-stage test are used as 
predictions of results of life-cycle and partial life-cycle tests 
with the same species. Therefore, when results of a life-cycle or 
partial life-cycle test are available, results of an early life-
stage test with the same species should not be used. Also, results 
of early life-stage tests in which the incidence of mortalities or 
abnormalities increased substantially near the end of the test shall 
not be used because the results of such tests are possibly not good 
predictions of comparable life-cycle or partial life-cycle tests.
    F. A chronic value may be obtained by calculating the geometric 
mean of the lower and upper chronic limits from a chronic test or by 
analyzing chronic data using regression analysis.
    1. A lower chronic limit is the highest tested concentration:
    a. In an acceptable chronic test;
    b. Which did not cause an unacceptable amount of adverse effect 
on any of the specified biological measurements; and
    c. Below which no tested concentration caused an unacceptable 
effect.
    2. An upper chronic limit is the lowest tested concentration:
    a. In an acceptable chronic test;
    b. Which did cause an unacceptable amount of adverse effect on 
one or more of the specified biological measurements; and,
    c. Above which all tested concentrations also caused such an 
effect.
    Note: Because various authors have used a variety of terms and 
definitions to interpret and report results of chronic tests, 
reported results should be reviewed carefully. The amount of effect 
that is considered unacceptable is often based on a statistical 
hypothesis test, but might also be defined in terms of a specified 
percent reduction from the controls. A small percent reduction 
(e.g., three percent) might be considered acceptable even if it is 
statistically significantly different from the control, whereas a 
large percent reduction (e.g., 30 percent) might be considered 
unacceptable even if it is not statistically significant.
    G. If the chronic toxicity of the material to aquatic animals 
has been shown to be related [[Page 15398]] to a water quality 
characteristic such as hardness or particulate matter for freshwater 
animals, refer to section VII of this appendix.
    H. If chronic values are available for species in eight families 
as described in section III.B.1 of this appendix, a SMCV shall be 
calculated for each species for which at least one chronic value is 
available by calculating the geometric mean of the results of all 
acceptable life-cycle and partial life-cycle toxicity tests with the 
species; for a species of fish for which no such result is 
available, the SMCV is the geometric mean of all acceptable early 
life-stage tests. Appropriate GMCVs shall also be calculated. A GMCV 
is the geometric mean of the SMCVs for the genus. The FCV shall be 
obtained using the procedure described in sections IV.J through IV.O 
of this appendix, substituting SMCV and GMCV for SMAV and GMAV 
respectively. See section VI.M of this appendix.
    Note: Section VI.I through VI.L are for use when chronic values 
are not available for species in eight taxonomic families as 
described in section III.B.1 of this appendix.
    I. For each chronic value for which at least one corresponding 
appropriate acute value is available, calculate an ACR, using for 
the numerator the geometric mean of the results of all acceptable 
flow-through (except static is acceptable for daphnids and midges) 
acute tests in the same dilution water in which the concentrations 
are measured. For fish, the acute test(s) should be conducted with 
juveniles. The acute test(s) should be part of the same study as the 
chronic test. If acute tests were not conducted as part of the same 
study, but were conducted as part of a different study in the same 
laboratory and dilution water, then they may be used. If no such 
acute tests are available, results of acute tests conducted in the 
same dilution water in a different laboratory may be used. If no 
such acute tests are available, an ACR shall not be calculated.
    J. For each species, calculate the SMACR as the geometric mean 
of all ACRs available for that species. If the minimum ACR data 
requirements (as described in section III.B.2 of this appendix) are 
not met with freshwater data alone, saltwater data may be used along 
with the freshwater data.
    K. For some materials, the ACR seems to be the same for all 
species, but for other materials the ratio seems to increase or 
decrease as the SMAV increases. Thus the FACR can be obtained in 
three ways, depending on the data available:
    1. If the species mean ACR seems to increase or decrease as the 
SMAVs increase, the FACR shall be calculated as the geometric mean 
of the ACRs for species whose SMAVs are close to the FAV.
    2. If no major trend is apparent and the ACRs for all species 
are within a factor of ten, the FACR shall be calculated as the 
geometric mean of all of the SMACRs.
    3. If the most appropriate SMACRs are less than 2.0, and 
especially if they are less than 1.0, acclimation has probably 
occurred during the chronic test. In this situation, because 
continuous exposure and acclimation cannot be assured to provide 
adequate protection in field situations, the FACR should be assumed 
to be two, so that the FCV is equal to the Criterion Maximum 
Concentration (CMC). (See section X.B of this appendix.)
    If the available SMACRs do not fit one of these cases, a FACR 
may not be obtained and a Tier I FCV probably cannot be calculated.
    L. Calculate the FCV by dividing the FAV by the FACR.
    FCV=FAVFACR
If there is a Final Acute Equation rather than a FAV, see also 
section V of this appendix.
    M. If the SMCV of a commercially or recreationally important 
species of the Great Lakes System is lower than the calculated FCV, 
then that SMCV must be used as the FCV instead of the calculated 
FCV.
    N. See section VIII of this appendix.

VII. Final Chronic Equation

    A. A Final Chronic Equation can be derived in two ways. The 
procedure described in section VII.A of this appendix will result in 
the chronic slope being the same as the acute slope. The procedure 
described in sections VII.B through N of this appendix will usually 
result in the chronic slope being different from the acute slope.
    1. If ACRs are available for enough species at enough values of 
the water quality characteristic to indicate that the ACR appears to 
be the same for all species and appears to be independent of the 
water quality characteristic, calculate the FACR as the geometric 
mean of the available SMACRs.
    2. Calculate the FCV at the selected value Z of the water 
quality characteristic by dividing the FAV at Z (see section V.M of 
this appendix) by the FACR.
    3. Use V=pooled acute slope (see section V.M of this appendix), 
and
    L=pooled chronic slope.
    4. See section VII.M of this appendix.
    B. When enough data are available to show that chronic toxicity 
to at least one species is related to a water quality 
characteristic, the relationship should be taken into account as 
described in sections C through G below or using analysis of 
covariance. The two methods are equivalent and produce identical 
results. The manual method described below provides an understanding 
of this application of covariance analysis, but computerized 
versions of covariance analysis are much more convenient for 
analyzing large data sets. If two or more factors affect toxicity, 
multiple regression analysis shall be used.
    C. For each species for which comparable chronic toxicity values 
are available at two or more different values of the water quality 
characteristic, perform a least squares regression of the chronic 
toxicity values on the corresponding values of the water quality 
characteristic to obtain the slope and its 95 percent confidence 
limits for each species.

    Note: Because the best documented relationship is that between 
hardness and acute toxicity of metals in fresh water and a log-log 
relationship fits these data, geometric means and natural logarithms 
of both toxicity and water quality are used in the rest of this 
section. For relationships based on other water quality 
characteristics, such as Ph, temperature, no transformation or a 
different transformation might fit the data better, and appropriate 
changes will be necessary throughout this section. It is probably 
preferable, but not necessary, to use the same transformation that 
was used with the acute values in section V of this appendix.

    D. Decide whether the data for each species are relevant, taking 
into account the range and number of the tested values of the water 
quality characteristic and the degree of agreement within and 
between species. For example, a slope based on six data points might 
be of limited value if it is based only on data for a very narrow 
range of values of the water quality characteristic. A slope based 
on only two data points, however, might be more useful if it is 
consistent with other information and if the two points cover a 
broad range of the water quality characteristic. In addition, 
chronic values that appear to be questionable in comparison with 
other acute and chronic data available for the same species and for 
other species in the same genus in most cases should not be used. 
For example, if after adjustment for the water quality 
characteristic, the chronic values available for a species or genus 
differ by more than a factor of 10, rejection of some or all of the 
values is, in most cases, absent countervailing circumstances, 
appropriate. If a useful chronic slope is not available for at least 
one species or if the available slopes are too dissimilar or if too 
few data are available to adequately define the relationship between 
chronic toxicity and the water quality characteristic, it might be 
appropriate to assume that the chronic slope is the same as the 
acute slope, which is equivalent to assuming that the ACR is 
independent of the water quality characteristic. Alternatively, 
return to section VI.H of this appendix, using the results of tests 
conducted under conditions and in waters similar to those commonly 
used for toxicity tests with the species.
    E. Individually for each species, calculate the geometric mean 
of the available chronic values and then divide each chronic value 
for a species by the mean for the species. This normalizes the 
chronic values so that the geometric mean of the normalized values 
for each species individually, and for any combination of species, 
is 1.0.
    F. Similarly, normalize the values of the water quality 
characteristic for each species individually.
    G. Individually for each species, perform a least squares 
regression of the normalized chronic toxicity values on the 
corresponding normalized values of the water quality characteristic. 
The resulting slopes and the 95 percent confidence limits will be 
identical to those obtained in section VII.B of this appendix. Now, 
however, if the data are actually plotted, the line of best fit for 
each individual species will go through the point 1,1 in the center 
of the graph.
    H. Treat all of the normalized data as if they were all the same 
species and perform a least squares regression of all of the 
normalized chronic values on the corresponding normalized values of 
the water quality characteristic to obtain the pooled chronic slope, 
L, and its 95 percent confidence limits.
    If all normalized data are actually plotted, the line of best 
fit will go through the point 1,1 in the center of the 
graph. [[Page 15399]] 
    I. For each species, calculate the geometric mean, M, of the 
toxicity values and the geometric mean, P, of the values of the 
water quality characteristic. (These are calculated in sections 
VII.E and F of this appendix.)
    J. For each species, calculate the logarithm, Q, of the SMCV at 
a selected value, Z, of the water quality characteristic using the 
equation:

Q=ln M--L(ln P-ln Z)

    Note: Although it is not necessary, it is recommended that the 
same value of the water quality characteristic be used here as was 
used in section V of this appendix.

    K. For each species, calculate a SMCV at Z using the equation:

SMCV=eQ

    Note: Alternatively, the SMCV at Z can be obtained by skipping 
section VII.J of this appendix, using the equations in sections 
VII.J and K of this appendix to adjust each chronic value 
individually to Z, and then calculating the geometric means of the 
adjusted values for each species individually. This alternative 
procedure allows an examination of the range of the adjusted chronic 
values for each species.

    L. Obtain the FCV at Z by using the procedure described in 
sections IV.J through O of this appendix.
    M. If the SMCV at Z of a commercially or recreationally 
important species of the Great Lakes System is lower than the 
calculated FCV at Z, then that SMCV shall be used as the FCV at Z 
instead of the calculated FCV.
    N. The Final Chronic Equation is written as:

FCV=e(L[ln(water quality characteristic)]+lnS-L[lnZ])

Where:

L=pooled chronic slope and S = FCV at Z.

    Because L, S, and Z are known, the FCV can be calculated for any 
selected value of the water quality characteristic.

VIII. Final Plant Value

    A. A Final Plant Value (FPV) is the lowest plant value that was 
obtained with an important aquatic plant species in an acceptable 
toxicity test for which the concentrations of the test material were 
measured and the adverse effect was biologically important. 
Appropriate measures of the toxicity of the material to aquatic 
plants are used to compare the relative sensitivities of aquatic 
plants and animals. Although procedures for conducting and 
interpreting the results of toxicity tests with plants are not well-
developed, results of tests with plants usually indicate that 
criteria which adequately protect aquatic animals and their uses 
will, in most cases, also protect aquatic plants and their uses.
    B. A plant value is the result of a 96-hour test conducted with 
an alga or a chronic test conducted with an aquatic vascular plant.

    Note: A test of the toxicity of a metal to a plant shall not be 
used if the medium contained an excessive amount of a complexing 
agent, such as EDTA, that might affect the toxicity of the metal. 
Concentrations of EDTA above 200 g/L should be considered 
excessive.

    C. The FPV shall be obtained by selecting the lowest result from 
a test with an important aquatic plant species in which the 
concentrations of test material are measured and the endpoint is 
biologically important.

IX. Other Data

    Pertinent information that could not be used in earlier sections 
might be available concerning adverse effects on aquatic organisms. 
The most important of these are data on cumulative and delayed 
toxicity, reduction in survival, growth, or reproduction, or any 
other adverse effect that has been shown to be biologically 
important. Delayed toxicity is an adverse effect to an organism that 
results from, and occurs after the end of, its exposure to one or 
more test materials. Especially important are data for species for 
which no other data are available. Data from behavioral, 
biochemical, physiological, microcosm, and field studies might also 
be available. Data might be available from tests conducted in 
unusual dilution water (see sections IV.D and VI.D of this 
appendix), from chronic tests in which the concentrations were not 
measured (see section VI.B of this appendix), from tests with 
previously exposed organisms (see section II.F.3 of this appendix), 
and from tests on formulated mixtures or emulsifiable concentrates 
(see section II.D of this appendix). Such data might affect a 
criterion if the data were obtained with an important species, the 
test concentrations were measured, and the endpoint was biologically 
important.

X. Criterion

    A. A criterion consists of two concentrations: the CMC and the 
Criterion Continuous Concentration (CCC).
    B. The CMC is equal to one-half the FAV. The CMC is an estimate 
of the highest concentration of a material in the water column to 
which an aquatic community can be exposed briefly without resulting 
in an unacceptable effect.
    C. The CCC is equal to the lowest of the FCV or the FPV (if 
available) unless other data (see section IX of this appendix) show 
that a lower value should be used. The CCC is an estimate of the 
highest concentration of a material in the water column to which an 
aquatic community can be exposed indefinitely without resulting in 
an unacceptable effect. If toxicity is related to a water quality 
characteristic, the CCC is obtained from the Final Chronic Equation 
or FPV (if available) that results in the lowest concentrations in 
the usual range of the water quality characteristic, unless other 
data (see section IX) show that a lower value should be used.
    D. Round both the CMC and the CCC to two significant digits.
    E. The criterion is stated as:
    The procedures described in the Tier I methodology indicate 
that, except possibly where a commercially or recreationally 
important species is very sensitive, aquatic organisms should not be 
affected unacceptably if the four-day average concentration of (1) 
does not exceed (2) g/L more than once every three years on 
the average and if the one-hour average concentration does not 
exceed (3) g/L more than once every three years on the 
average.
Where:

(1) = insert name of material
(2) = insert the CCC
(3) = insert the CMC

    If the CMC averaging period of one hour or the CCC averaging 
period of four days is inappropriate for the pollutant, or if the 
once-in-three-year allowable excursion frequency is inappropriate 
for the pollutant or for the sites to which a criterion is applied, 
then the State may specify alternative averaging periods or 
frequencies. The choice of an alternative averaging period or 
frequency shall be justified by a scientifically defensible analysis 
demonstrating that the alternative values will protect the aquatic 
life uses of the water. Appropriate laboratory data and/or well-
designed field biological surveys shall be submitted to EPA as 
justification for differing averaging periods and/or frequencies of 
exceedance.

XI. Final Review

    A. The derivation of the criterion should be carefully reviewed 
by rechecking each step of the Guidance in this part. Items that 
should be especially checked are:
    1. If unpublished data are used, are they well documented?
    2. Are all required data available?
    3. Is the range of acute values for any species greater than a 
factor of 10?
    4. Is the range of SMAVs for any genus greater than a factor of 
10?
    5. Is there more than a factor of 10 difference between the four 
lowest GMAVs?
    6. Are any of the lowest GMAVs questionable?
    7. Is the FAV reasonable in comparison with the SMAVs and GMAVs?
    8. For any commercially or recreationally important species of 
the Great Lakes System, is the geometric mean of the acute values 
from flow-through tests in which the concentrations of test material 
were measured lower than the FAV?
    9. Are any of the chronic values used questionable?
    10. Are any chronic values available for acutely sensitive 
species?
    11. Is the range of acute-chronic ratios greater than a factor 
of 10?
    12. Is the FCV reasonable in comparison with the available acute 
and chronic data?
    13. Is the measured or predicted chronic value for any 
commercially or recreationally important species of the Great Lakes 
System below the FCV?
    14. Are any of the other data important?
    15. Do any data look like they might be outliers?
    16. Are there any deviations from the Guidance in this part? Are 
they acceptable?
    B. On the basis of all available pertinent laboratory and field 
information, determine if the criterion is consistent with sound 
scientific evidence. If it is not, another criterion, either higher 
or lower, shall be derived consistent with the Guidance in this 
part.

Methodology for Deriving Aquatic Life Values: Tier II [[Page 15400]] 

XII. Secondary Acute Value

    If all eight minimum data requirements for calculating an FAV 
using Tier I are not met, a Secondary Acute Value (SAV) for the 
waters of the Great Lakes System shall be calculated for a chemical 
as follows:
    To calculate a SAV, the lowest GMAV in the database is divided 
by the Secondary Acute Factor (SAF) (Table A-1 of this appendix) 
corresponding to the number of satisfied minimum data requirements 
listed in the Tier I methodology (section III.B.1 of this appendix). 
(Requirements for definitions, data collection and data review, 
contained in sections I, II, and IV shall be applied to calculation 
of a SAV.) If all eight minimum data requirements are satisfied, a 
Tier I criterion calculation may be possible. In order to calculate 
a SAV, the database must contain, at a minimum, a genus mean acute 
value (GMAV) for one of the following three genera in the family 
Daphnidae--Ceriodaphnia sp., Daphnia sp., or Simocephalus sp.
    If appropriate, the SAV shall be made a function of a water 
quality characteristic in a manner similar to that described in Tier 
I.

XIII. Secondary Acute-Chronic Ratio

    If three or more experimentally determined ACRs, meeting the 
data collection and review requirements of Section VI of this 
appendix, are available for the chemical, determine the FACR using 
the procedure described in Section VI. If fewer than three 
acceptable experimentally determined ACRs are available, use enough 
assumed ACRs of 18 so that the total number of ACRs equals three. 
Calculate the Secondary Acute-Chronic Ratio (SACR) as the geometric 
mean of the three ACRs. Thus, if no experimentally determined ACRs 
are available, the SACR is 18.

XIV. Secondary Chronic Value

    Calculate the Secondary Chronic Value (SCV) using one of the 
following:
[GRAPHIC][TIFF OMITTED]TR23MR95.099


    If appropriate, the SCV will be made a function of a water 
quality characteristic in a manner similar to that described in Tier 
I.

XV. Commercially or Recreationally Important Species

    If for a commercially or recreationally important species of the 
Great Lakes System the geometric mean of the acute values or chronic 
values from flow-through tests in which the concentrations of the 
test materials were measured is lower than the calculated SAV or 
SCV, then that geometric mean must be used as the SAV or SCV instead 
of the calculated SAV or SCV.

XVI. Tier II Value

    A. A Tier II value shall consist of two concentrations: the 
Secondary Maximum Concentration (SMC) and the Secondary Continuous 
Concentration (SCC).
    B. The SMC is equal to one-half of the SAV.
    C. The SCC is equal to the lowest of the SCV or the Final Plant 
Value, if available, unless other data (see section IX of this 
appendix) show that a lower value should be used.
    If toxicity is related to a water quality characteristic, the 
SCC is obtained from the Secondary Chronic Equation or FPV, if 
available, that results in the lowest concentrations in the usual 
range of the water quality characteristic, unless other data (See 
section IX of this appendix) show that a lower value should be used.
    D. Round both the SMC and the SCC to two significant digits.
    E. The Tier II value is stated as:
    The procedures described in the Tier II methodology indicate 
that, except possibly where a locally important species is very 
sensitive, aquatic organisms should not be affected unacceptably if 
the four-day average concentration of (1) does not exceed (2) 
g/L more than once every three years on the average and if 
the one-hour average concentration does not exceed (3) g/L 
more than once every three years on the average.

Where:

(1) = insert name of material
(2) = insert the SCC
(3) = insert the SMC
    As discussed above, States and Tribes have the discretion to 
specify alternative averaging periods or frequencies (see section 
X.E. of this appendix).

XVII. Appropriate Modifications

    On the basis of all available pertinent laboratory and field 
information, determine if the Tier II value is consistent with sound 
scientific evidence. If it is not, another value, either higher or 
lower, shall be derived consistent with the Guidance in this part.

                   Table A-1.-- Secondary Acute Factors                 
------------------------------------------------------------------------
                                                              Adjustment
        Number of minimum data requirements satisfied           factor  
------------------------------------------------------------------------
1...........................................................        21.9
2...........................................................        13.0
3...........................................................         8.0
4...........................................................         7.0
5...........................................................         6.1
6...........................................................         5.2
7...........................................................         4.3
------------------------------------------------------------------------

Appendix B to Part 132--Great Lakes Water Quality Initiative

Methodology for Deriving Bioaccumulation Factors

    Great Lakes States and Tribes shall adopt provisions consistent 
with (as protective as) this appendix.

I. Introduction

    A. The purpose of this methodology is to describe procedures for 
deriving bioaccumulation factors (BAFs) to be used in the 
calculation of Great Lakes Water Quality Guidance (Guidance) human 
health Tier I criteria and Tier II values and wildlife Tier I 
criteria. A subset of the human health BAFs are also used to 
identify the chemicals that are considered bioaccumulative chemicals 
of concern (BCCs).
    B. Bioaccumulation reflects uptake of a substance by aquatic 
organisms exposed to the substance through all routes (i.e., ambient 
water and food), as would occur in nature. Bioconcentration reflects 
uptake of a substance by aquatic organisms exposed to the substance 
only through the ambient water. Both BAFs and bioconcentration 
factors (BCFs) are proportionality constants that describe the 
relationship between the concentration of a substance in aquatic 
organisms and its concentration in the ambient water. For the 
Guidance in this part, BAFs, rather than BCFs, are used to calculate 
Tier I criteria for human health and wildlife and Tier II values for 
human health because they better account for the total exposure of 
aquatic organisms to chemicals.
    C. For organic chemicals, baseline BAFs can be derived using 
four methods. Measured baseline BAFs are derived from field-measured 
BAFs; predicted baseline BAFs are derived using biota-sediment 
accumulation factors (BSAFs) or are derived by multiplying a 
laboratory-measured or predicted BCF by a food-chain multiplier 
(FCM). The lipid content of the aquatic organisms is used to account 
for partitioning of organic chemicals within organisms so that data 
from different [[Page 15401]] tissues and species can be integrated. 
In addition, the baseline BAF is based on the concentration of 
freely dissolved organic chemicals in the ambient water to 
facilitate extrapolation from one water to another.
    D. For inorganic chemicals, baseline BAFs can be derived using 
two of the four methods. Baseline BAFs are derived using either 
field-measured BAFs or by multiplying laboratory-measured BCFs by a 
FCM. For inorganic chemicals, BAFs are assumed to equal BCFs (i.e., 
the FCM is 1.0), unless chemical-specific biomagnification data 
support using a FCM other than 1.0.
    E. Because both humans and wildlife consume fish from both 
trophic levels 3 and 4, two baseline BAFs are needed to calculate 
either a human health criterion or value or a wildlife criterion for 
a chemical. When appropriate, ingestion through consumption of 
invertebrates, plants, mammals, and birds in the diet of wildlife 
species to be protected may be taken into account.

II. Definitions

    Baseline BAF. For organic chemicals, a BAF that is based on the 
concentration of freely dissolved chemical in the ambient water and 
takes into account the partitioning of the chemical within the 
organism; for inorganic chemicals, a BAF that is based on the wet 
weight of the tissue.
    Baseline BCF. For organic chemicals, a BCF that is based on the 
concentration of freely dissolved chemical in the ambient water and 
takes into account the partitioning of the chemical within the 
organism; for inorganic chemicals, a BCF that is based on the wet 
weight of the tissue.
    Bioaccumulation. The net accumulation of a substance by an 
organism as a result of uptake from all environmental sources.
    Bioaccumulation factor (BAF). The ratio (in L/kg) of a 
substance's concentration in tissue of an aquatic organism to its 
concentration in the ambient water, in situations where both the 
organism and its food are exposed to and the ratio does not change 
substantially over time.
    Bioconcentration. The net accumulation of a substance by an 
aquatic organism as a result of uptake directly from the ambient 
water through gill membranes or other external body surfaces.
    Bioconcentration factor (BCF). The ratio (in L/kg) of a 
substance's concentration in tissue of an aquatic organism to its 
concentration in the ambient water, in situations where the organism 
is exposed through the water only and the ratio does not change 
substantially over time.
    Biota-sediment accumulation factor (BSAF). The ratio (in kg of 
organic carbon/kg of lipid) of a substance's lipid-normalized 
concentration in tissue of an aquatic organism to its organic 
carbon-normalized concentration in surface sediment, in situations 
where the ratio does not change substantially over time, both the 
organism and its food are exposed, and the surface sediment is 
representative of average surface sediment in the vicinity of the 
organism.
    Depuration. The loss of a substance from an organism as a result 
of any active or passive process.
    Food-chain multiplier (FCM). The ratio of a BAF to an 
appropriate BCF.
    Octanol-water partition coefficient (KOW). The ration of 
the concentration of a substance in the n-octanol phase to its 
concentration in the aqueous phase in an equilibrated two-phase 
octanol-water system. For log KOW, the log of the octanol-water 
partition coefficient is a base 10 logarithm.
    Uptake. Acquisition of a substance from the environment by an 
organism as a result of any active or passive process.

III. Review and Selection of Data

    A. Data Sources.  Measured BAFs, BSAFs and BCFs are assembled 
from available sources including the following:
    1. EPA Ambient Water Quality Criteria documents issued after 
January 1, 1980.
    2. Published scientific literature.
    3. Reports issued by EPA or other reliable sources.
    4. Unpublished data.
    One useful source of references is the Aquatic Toxicity 
Information Retrieval (AQUIRE) database.
    B. Field-Measured BAFs. The following procedural and quality 
assurance requirements shall be met for field-measured BAFs:
    1. The field studies used shall be limited to those conducted in 
the Great Lakes System with fish at or near the top of the aquatic 
food chain (i.e., in trophic levels 3 and/or 4).
    2. The trophic level of the fish species shall be determined.
    3. The site of the field study should not be so unique that the 
BAF cannot be extrapolated to other locations where the criteria and 
values will apply.
    4. For organic chemicals, the percent lipid shall be either 
measured or reliably estimated for the tissue used in the 
determination of the BAF.
    5. The concentration of the chemical in the water shall be 
measured in a way that can be related to particulate organic carbon 
(POC) and/or dissolved organic carbon (DOC) and should be relatively 
constant during the steady-state time period.
    6. For organic chemicals with log Kow greater than four, 
the concentrations of POC and DOC in the ambient water shall be 
either measured or reliably estimated.
    7. For inorganic and organic chemicals, BAFs shall be used only 
if they are expressed on a wet weight basis; BAFs reported on a dry 
weight basis cannot be converted to wet weight unless a conversion 
factor is measured or reliably estimated for the tissue used in the 
determination of the BAF.
    C. Field-Measured BSAFs. The following procedural and quality 
assurance requirements shall be met for field-measured BSAFs:
    1. The field studies used shall be limited to those conducted in 
the Great Lakes System with fish at or near the top of the aquatic 
food chain (i.e., in trophic levels 3 and/or 4).
    2. Samples of surface sediments (0-1 cm is ideal) shall be from 
locations in which there is net deposition of fine sediment and is 
representative of average surface sediment in the vicinity of the 
organism.
    3. The Kows used shall be acceptable quality as described 
in section III.F below.
    4. The site of the field study should not be so unique that the 
resulting BAF cannot be extrapolated to other locations where the 
criteria and values will apply.
    5. The tropic level of the fish species shall be determined.
    6. The percent lipid shall be either measured or reliably 
estimated for the tissue used in the determination of the BAF.
    D. Laboratory-Measured BCFs. The following procedural and 
quality assurance requirements shall be met for laboratory-measured 
BCFs:
    1. The test organism shall not be diseased, unhealthy, or 
adversely affected by the concentration of the chemical.
    2. The total concentration of the chemical in the water shall be 
measured and should be relatively constant during the steady-state 
time period.
    3. The organisms shall be exposed to the chemical using a flow-
through or renewal procedure.
    4. For organic chemicals, the percent lipid shall be either 
measured or reliably estimated for the tissue used in the 
determination of the BCF.
    5. For organic chemicals with log Kow greater than four, 
the concentrations of POC and DOC in the test solution shall be 
either measured or reliably estimated.
    6. Laboratory-measured BCFs should be determined using fish 
species, but BCFs determined with molluscs and other invertebrates 
may be used with caution. For example, because invertebrates 
metabolize some chemicals less efficiently than vertebrates, a 
baseline BCF determined for such a chemical using invertebrates is 
expected to be higher than a comparable baseline BCF determined 
using fish.
    7. If laboratory-measured BCFs increase or decrease as the 
concentration of the chemical increases in the test solutions in a 
bioconcentration test, the BCF measured at the lowest test 
concentration that is above concentrations existing in the control 
water shall be used (i.e., a BCF should be calculated from a control 
treatment). The concentrations of an inorganic chemical in a 
bioconcentration test should be greater than normal background 
levels and greater than levels required for normal nutrition of the 
test species if the chemical is a micronutrient, but below levels 
that adversely affect the species. Bioaccummulation of an inorganic 
chemical might be overestimated if concentrations are at or below 
normal background levels due to, for example, nutritional 
requirements of the test organisms.
    8. For inorganic and organic chemicals, BCFs shall be used only 
if they are expressed on a wet weight basis. BCFs reported on a dry 
weight basis cannot be converted to wet weight unless a conversion 
factor is measured or reliably estimated for the tissue used in the 
determination of the BAF.
    9. BCFs for organic chemicals may be based on measurement or 
radioactivity only when the BCF is intended to include metabolites 
or when there is confidence that there is no interference due to 
metabolites.
    10. The calculation of the BCF must appropriately address growth 
dilution.
    11. Other aspects of the methodology used should be similar to 
those described by ASTM (1990). [[Page 15402]] 
    E. Predicted BCFs. The following procedural and quality 
assurance requirements shall be met for predicted BCFs:
    1. The Kow used shall be of acceptable quality as described 
in section III.F below.
    2. The predicted baseline BCF shall be calculated using the 
equation: predicted baseline BCF = Kow
    where:
    Kow = octanol-water partition coefficient.
    F. Octanol-Water Partition Coefficient (Kow). 1. The value 
of Kow used for an organic chemical shall be determined by 
giving priority to the experimental and computational techniques 
used as follows:
    Log Kow < 4:

------------------------------------------------------------------------
              Priority                            Technique             
------------------------------------------------------------------------
1..................................  Slow-stir.                         
1..................................  Generator-column.                  
1..................................  Shake-flask.                       
2..................................  Reverse-phase liquid chromatography
                                      on C18 chromatography packing with
                                      extrapolation to zero percent     
                                      solvent.                          
3..................................  Reverse-phase liquid chromatography
                                      on C18 chromatography packing     
                                      without extrapolation to zero     
                                      percent solvent.                  
4..................................  Calculated by the CLOGP program.   
------------------------------------------------------------------------

    Log Kow > 4:

------------------------------------------------------------------------
   Priority                            Technique                        
------------------------------------------------------------------------
1............  Slow Stir.                                               
1............  Generator-column.                                        
2............  Reverse-phase liquid chromatography on C18 chromatography
                packing with extrapolation to zero percent solvent.     
3............  Reverse-phase liquid chromatography on C18 chromatography
                packing without extrapolation to zero percent solvent.  
4............  Shake-flask.                                             
5............  Calculated by the CLOGP program.                         
------------------------------------------------------------------------

    2. The CLOGP program is a computer program available from Pomona 
College. A value of Kow that seems to be different from the 
others should be considered an outlier and not used. The value of 
Kow used for an organic chemical shall be the geometric mean of 
the available Kows with highest priority or can be calculated 
from the arithmetic mean of the available log Kow with the 
highest priority. Because it is an intermediate value in the 
derivation of a BAF, the value used for the Kow of a chemical 
should not be rounded to fewer than three significant digits and a 
value for log Kow should not be rounded to fewer than three 
significant digits after the decimal point.
    G. This methodology provides overall guidance for the derivation 
of BAFs, but it cannot cover all the decisions that must be made in 
the review and selection of acceptable data. Professional judgment 
is required throughout the process. A degree of uncertainty is 
associated with the determination of any BAF, BSAF, BCF or Kow. 
The amount of uncertainty in a baseline BAF depends on both the 
quality of data available and the method used to derive the BAF.
    H. Hereinafter in this methodology, the terms BAF, BSAF, BCF and 
Kow refer to ones that are consistent with the procedural and 
quality assurance requirements given above.

IV. Four Methods for Deriving Baseline BAFs

    Baseline BAFs shall be derived using the following four methods, 
which are listed from most preferred to least preferred:
    A. A measured baseline BAF for an organic or inorganic chemical 
derived from a field study of acceptable quality.
    B. A predicted baseline BAF for an organic chemical derived 
using field-measured BSAFs of acceptable quality.
    C. A predicted baseline BAF for an organic or inorganic chemical 
derived from a BCF measured in a laboratory study of acceptable 
quality and a FCM.
    D. A predicted baseline BAF for an organic chemical derived from 
a Kow of acceptable quality and a FCM.
    For comparative purposes, baseline BAFs should be derived for 
each chemical by as many of the four methods as available data 
allow.

V. Calculation of Baseline BAFs for Organic Chemicals

    A. Lipid Normalization. 1. It is assumed that BAFs and BCFs for 
organic chemicals can be extrapolated on the basis of percent lipid 
from one tissue to another and from one aquatic species to another 
in most cases.
    2. Because BAFs and BCFs for organic chemicals are related to 
the percent lipid, it does not make any difference whether the 
tissue sample is whole body or edible portion, but both the BAF (or 
BCF) and the percent lipid must be determined for the same tissue. 
The percent lipid of the tissue should be measured during the BAF or 
BCF study, but in some cases it can be reliably estimated from 
measurements on tissue from other organisms. If percent lipid is not 
reported for the test organisms in the original study, it may be 
obtained from the author; or, in the case of a laboratory study, 
lipid data for the same or a comparable laboratory population of 
test organisms that were used in the original study may be used.
    3. The lipid-normalized concentration, Cl, of a chemical in 
tissue is defined using the following equation:
[GRAPHIC][TIFF OMITTED]TR23MR95.100


Where:

CB=concentration of the organic chemical in the tissue of 
aquatic biota (either whole organism or specified tissue) 
(g/g).
fl=fraction of the tissue that is lipid.

    B. Bioavailability. By definition, baseline BAFs and BCFs for 
organic chemicals, whether measured or predicted are based on the 
concentration of the chemical that is freely dissolved in the 
ambient water in order to account for bioavailability. For the 
purposes of this Guidance in this part, the relationship between the 
total concentration of the chemical in the water (i.e., that which 
is freely dissolved plus that which is sorbed to particulate organic 
carbon or to dissolved organic carbon) to the freely dissolved 
concentration of the chemical in the ambient water shall be 
calculated using the following equation:
[GRAPHIC][TIFF OMITTED]TR23MR95.101


Where:

Cfdw=freely dissolved concentration of the organic 
chemical in the ambient water;
Ctw=total concentration of the organic chemical in the 
ambient water;
ffd=fraction of the total chemical in the ambient water that is 
freely dissolved.

    The fraction of the total chemical in the ambient water that is 
freely dissolved, ffd, shall be calculated using the following 
equation:
[GRAPHIC][TIFF OMITTED]TR23MR95.102


Where:

DOC=concentration of dissolved organic carbon, kg of dissolved 
organic carbon/L of water.
KOW=octanol-water partition coefficient of the chemical.
POC=concentration of particulate organic carbon, kg of particulate 
organic carbon/L of water.

    C. Food-Chain Multiplier. In the absence of a field-measured BAF 
or a predicted BAF derived from a BSAF, a FCM shall be used to 
calculate the baseline BAF for trophic levels 3 and 4 from a 
laboratory-measured or predicted BCF. For an organic chemical, the 
FCM used shall be derived from Table B-1 using the chemical's log 
KOW and linear interpolation. A FCM greater than 1.0 applies to 
most organic chemicals with a log KOW of four or more. The 
trophic level used shall take into account the age or size of the 
fish species consumed by the human, avian or mammalian predator 
because, for some species of fish, the young are in trophic level 3 
whereas the adults are in trophic level 4.
    D. Calculation of a Baseline BAF from a Field-Measured BAF. A 
baseline BAF shall be calculated from a field-measured BAF of 
                    acceptable quality using the following equation:
[[Page 15403]]

[GRAPHIC][TIFF OMITTED]TR23MR95.103


Where:

BAFtT=BAF based on total concentration in tissue and 
water.
fl=fraction of the tissue that is lipid.
ffd=fraction of the total chemical that is freely dissolved in 
the ambient water.

The trophic level to which the baseline BAF applies is the same as 
the trophic level of the organisms used in the determination of the 
field-measured BAF. For each trophic level, a species mean measured 
baseline BAF shall be calculated as the geometric mean if more than 
one measured baseline BAF is available for a given species. For each 
trophic level, the geometric mean of the species mean measured 
baseline BAFs shall be calculated. If a baseline BAF based on a 
measured BAF is available for either trophic level 3 or 4, but not 
both, a measured baseline BAF for the other trophic level shall be 
calculated using the ratio of the FCMs that are obtained by linear 
interpolation from Table B-1 for the chemical.
    E. Calculation of a Baseline BAF from a Field-Measured BSAF. 1. 
A baseline BAF for organic chemical ``i'' shall be calculated from a 
field-measured BSAF of acceptable quality using the following 
equation:
[GRAPHIC][TIFF OMITTED]TR23MR95.105


Where:

(BSAF)i=BSAF for chemical ``i''.
(BSAF)r=BSAF for the reference chemical ``r''.
(KOW)i=octanol-water partition coefficient for chemical 
``i''.
(KOW)r=octanol-water partition coefficient for the 
reference chemical ``r''.

    2. A BSAF shall be calculated using the following equation:
[GRAPHIC][TIFF OMITTED]TR23MR95.106


Where:

Ct=the lipid-normalized concentration of the chemical in 
tissue.
CSOC=the organic carbon-normalized concentration of the 
chemical in sediment.

    3. The organic carbon-normalized concentration of a chemical in 
sediment, CSOC, shall be calculated using the following 
equation:
[GRAPHIC][TIFF OMITTED]TR23MR95.107



Where:

CS=concentration of chemical in sediment (g/g 
sediment).
fOC=fraction of the sediment that is organic carbon.

    4. Predicting BAFs from BSAFs requires data from a steady-state 
(or near steady-state) condition between sediment and ambient water 
for both a reference chemical ``r'' with a field-measured 
BAFlfd and other chemicals ``n=i'' for which BSAFs are to 
be determined.
    5. The trophic level to which the baseline BAF applies is the 
same as the trophic level of the organisms used in the determination 
of the BSAF. For each trophic level, a species mean baseline BAF 
shall be calculated as the geometric mean if more than one baseline 
BAF is predicted from BSAFs for a given species. For each trophic 
level, the geometric mean of the species mean baseline BAFs derived 
using BSAFs shall be calculated.
    6. If a baseline BAF based on a measured BSAF is available for 
either trophic level 3 or 4, but not both, a baseline BAF for the 
other trophic level shall be calculated using the ratio of the FCMs 
that are obtained by linear interpolation from Table B-1 for the 
chemical.
    F. Calculation of a Baseline BAF from a Laboratory-Measured BCF. 
A baseline BAF for trophic level 3 and a baseline BAF for trophic 
level 4 shall be calculated from a laboratory-measured BCF of 
acceptable quality and a FCM using the following equation:
[GRAPHIC][TIFF OMITTED]TR23MR95.108


Where:

BCFtT=BCF based on total concentration in tissue and 
water.
fl=fraction of the tissue that is lipid.
ffd=fraction of the total chemical in the test water that is 
freely dissolved.
FCM=the food-chain multiplier obtained from Table B-1 by linear 
interpolation for trophic level 3 or 4, as necessary.

For each trophic level, a species mean baseline BAF shall be 
calculated as the geometric mean if more than one baseline BAF is 
predicted from laboratory-measured BCFs for a given species. For 
each trophic level, the geometric mean of the species mean baseline 
BAFs based on laboratory-measured BCFs shall be calculated.
    G. Calculation of a Baseline BAF from an Octanol-Water Partition 
Coefficient. A baseline BAF for trophic level 3 and a baseline BAF 
for trophic level 4 shall be calculated from a KOW of 
acceptable quality and a FCM using the following equation:
    Baseline BAF=(FCM) (predicted baseline BCF)=(FCM) (KOW)

Where:

FCM=the food-chain multiplier obtained from Table B-1 by linear 
interpolation for trophic level 3 or 4, as necessary.
KOW=octanol-water partition coefficient.

VI. Human Health and Wildlife BAFs for Organic Chemicals

    A. To calculate human health and wildlife BAFs for an organic 
chemical, the KOW of the [[Page 15404]] chemical shall be used 
with a POC concentration of 0.00000004 kg/L and a DOC concentration 
of 0.000002 kg/L to yield the fraction freely dissolved:
[GRAPHIC][TIFF OMITTED]TR23MR95.109


    B. The human health BAFs for an organic chemical shall be 
calculated using the following equations:
    For trophic level 3:
[GRAPHIC][TIFF OMITTED]TR23MR95.110


    For trophic level 4:
[GRAPHIC][TIFF OMITTED]TR23MR95.111


Where:

    0.0182 and 0.0310 are the standardized fraction lipid values for 
trophic levels 3 and 4, respectively, that are used to derive human 
health criteria and values for the GLI.
    C. The wildlife BAFs for an organic chemical shall be calculated 
using the following equations:
    For trophic level 3:
[GRAPHIC][TIFF OMITTED]TR23MR95.112


    For trophic level 4:
[GRAPHIC][TIFF OMITTED]TR23MR95.113


Where:
    0.0646 and 0.1031 are the standardized fraction lipid values for 
trophic levels 3 and 4, respectively, that are used to derive 
wildlife criteria for the GLI.

VII. Human Health and Wildlife BAFs for Inorganic Chemicals

    A. For inorganic chemicals, the baseline BAFs for trophic levels 
3 and 4 are both assumed to equal the BCF determined for the 
chemical with fish, i.e., the FCM is assumed to be 1 for both 
trophic levels 3 and 4. However, a FCM greater than 1 might be 
applicable to some metals, such as mercury, if, for example, an 
organometallic form of the metal biomagnifies.
    B. BAFs for Human Health Criteria and Values.
    1. Measured BAFs and BCFs used to determine human health BAFs 
for inorganic chemicals shall be based on edible tissue (e.g., 
muscle) of freshwater fish unless it is demonstrated that whole-body 
BAFs or BCFs are similar to edible-tissue BAFs or BCFs. BCFs and 
BAFs based on measurements of aquatic plants and invertebrates 
should not be used in the derivation of human health criteria and 
values.
    2. If one or more field-measured baseline BAFs for an inorganic 
chemical are available from studies conducted in the Great Lakes 
System with the muscle of fish:
    a. For each trophic level, a species mean measured baseline BAF 
shall be calculated as the geometric mean if more than one measured 
BAF is available for a given species; and
    b. For each trophic level, the geometric mean of the species 
mean measured baseline BAFs shall be used as the human health BAF 
for that chemical.
    3. If an acceptable measured baseline BAF is not available for 
an inorganic chemical and one or more acceptable edible-portion 
laboratory-measured BCFs are available for the chemical, a predicted 
baseline BAF shall be calculated by multiplying the geometric mean 
of the BCFs times a FCM. The FCM will be 1.0 unless chemical-
specific biomagnification data support using a multiplier other than 
1.0. The predicted baseline BAF shall be used as the human health 
BAF for that chemical.
    C. BAFs for Wildlife Criteria.
    1. Measured BAFs and BCFs used to determine wildlife BAFs for 
inorganic chemicals shall be based on whole-body freshwater fish and 
invertebrate data unless it is demonstrated that edible-tissue BAFs 
or BCFs are similar to whole-body BAFs or BCFs.
[[Page 15405]]

    2. If one or more field-measured baseline BAFs for an inorganic 
chemical are available from studies conducted in the Great Lakes 
System with whole body of fish or invertebrates:
    2. For each trophic level, a species mean measured baseline BAF 
shall be calculated as the geometric mean if more than one measured 
BAF is available for a given species.
    b. For each trophic level, the geometric mean of the species 
mean measured baseline BAFs shall be used as the wildlife BAF for 
that chemical.
    3. If an acceptable measured baseline BAF is not available for 
an inorganic chemical and one or more acceptable whole-body 
laboratory-measured BCFs are available for the chemical, a predicted 
baseline BAF shall be calculated by multiplying the geometric mean 
of the BCFs times a FCM. The FCM will be 1.0 unless chemical-
specific biomagnification data support using a multiplier other than 
1.0. The predicted baseline BAF shall be used as the wildlife BAF 
for that chemical.

VIII. Final Review

    For both organic and inorganic chemicals, human health and 
wildlife BAFs for both trophic levels shall be reviewed for 
consistency with all available data concerning the bioaccumulation, 
bioconcentration, and metabolism of the chemical. For example, 
information concerning octanol-water partitioning, molecular size, 
or other physicochemical properties that might enhance or inhibit 
bioaccumulation should be considered for organic chemicals. BAFs 
derived in accordance with this methodology should be modified if 
changes are justified by available data.

IX. Literature Cited

    ASTM. 1990. Standard Practice for Conducting Bioconcentration 
Tests with Fishes and Saltwater Bivalve Molluscs. Standard E 1022. 
American Society for Testing and Materials, Philadelphia, PA.

     Table B-1.--Food-Chain Multipliers for Trophic Levels 2, 3 & 4     
------------------------------------------------------------------------
                                     Trophic     Trophic\1\    Trophic  
             Log Kow                 level 2      level 3      level 4  
------------------------------------------------------------------------
2.0..............................        1.000        1.005        1.000
2.5..............................        1.000        1.010        1.002
3.0..............................        1.000        1.028        1.007
3.1..............................        1.000        1.034        1.007
3.2..............................        1.000        1.042        1.009
3.3..............................        1.000        1.053        1.012
3.4..............................        1.000        1.067        1.014
3.5..............................        1.000        1.083        1.019
3.6..............................        1.000        1.103        1.023
3.7..............................        1.000        1.128        1.033
3.8..............................        1.000        1.161        1.042
3.9..............................        1.000        1.202        1.054
4.0..............................        1.000        1.253        1.072
4.1..............................        1.000        1.315        1.096
4.2..............................        1.000        1.380        1.130
4.3..............................        1.000        1.491        1.178
4.4..............................        1.000        1.614        1.242
4.5..............................        1.000        1.766        1.334
4.6..............................        1.000        1.950        1.459
4.7..............................        1.000        2.175        1.633
4.8..............................        1.000        2.452        1.871
4.9..............................        1.000        2.780        2.193
5.0..............................        1.000        3.181        2.612
5.1..............................        1.000        3.643        3.162
5.2..............................        1.000        4.188        3.873
5.3..............................        1.000        4.803        4.742
5.4..............................        1.000        5.502        5.821
5.5..............................        1.000        6.266        7.079
5.6..............................        1.000        7.096        8.551
5.7..............................        1.000        7.962       10.209
5.8..............................        1.000        8.841       12.050
5.9..............................        1.000        9.716       13.964
6.0..............................        1.000       10.556       15.996
6.1..............................        1.000       11.337       17.783
6.2..............................        1.000       12.064       19.907
6.3..............................        1.000       12.691       21.677
6.4..............................        1.000       13.228       23.281
6.5..............................        1.000       13.662       24.604
6.6..............................        1.000       13.980       25.645
6.7..............................        1.000       14.223       26.363
6.8..............................        1.000       14.355       26.669
6.9..............................        1.000       14.388       26.669
7.0..............................        1.000       14.305       26.242
7.1..............................        1.000       14.142       25.468
7.2..............................        1.000       13.852       24.322
7.3..............................        1.000       13.474       22.856
7.4..............................        1.000       12.987       21.038
7.5..............................        1.000       12.517       18.967
7.6..............................        1.000       11.708       16.749
7.7..............................        1.000       10.914       14.388
7.8..............................        1.000       10.069       12.050
7.9..............................        1.000        9.162        9.840
8.0..............................        1.000        8.222        7.798
8.1..............................        1.000        7.278        6.012
[[Page 15406]]                                                          
                                                                        
8.2..............................        1.000        6.361        4.519
8.3..............................        1.000        5.489        3.311
8.4..............................        1.000        4.683        2.371
8.5..............................        1.000        3.949        1.663
8.6..............................        1.000        3.296        1.146
8.7..............................        1.000        2.732        0.778
8.8..............................        1.000        2.246        0.521
8.9..............................        1.000        1.837        0.345
9.0..............................        1.000        1.493        0.226
------------------------------------------------------------------------
\1\The FCMs for trophic level 3 are the geometric mean of the FCMs for  
  sculpin and alewife.                                                  

Appendix C to Part 132--Great Lakes Water Quality Initiative 
Methodologies for Development of Human Health Criteria and Values

    Great Lakes States and Tribes shall adopt provisions consistent 
with (as protective as) this appendix.

I. Introduction

    Great Lakes States and Tribes shall adopt provisions consistent 
with this appendix C to ensure protection of human health.
    A. Goal. The goal of the human health criteria for the Great 
Lakes System is the protection of humans from unacceptable exposure 
to toxicants via consumption of contaminated fish and drinking water 
and from ingesting water as a result of participation in water-
oriented recreational activities.
    B. Definitions.
    Acceptable daily exposure (ADE). An estimate of the maximum 
daily dose of a substance which is not expected to result in adverse 
noncancer effects to the general human population, including 
sensitive subgroups.
    Adverse effect. Any deleterious effect to organisms due to 
exposure to a substance. This includes effects which are or may 
become debilitating, harmful or toxic to the normal functions of the 
organism, but does not include non-harmful effects such as tissue 
discoloration alone or the induction of enzymes involved in the 
metabolism of the substance.
    Carcinogen. A substance which causes an increased incidence of 
benign or malignant neoplasms, or substantially decreases the time 
to develop neoplasms, in animals or humans. The classification of 
carcinogens is discussed in section II.A of appendix C to part 132.
    Human cancer criterion (HCC). A Human Cancer Value (HCV) for a 
pollutant that meets the minimum data requirements for Tier I 
specified in appendix C.
    Human cancer value (HCV). The maximum ambient water 
concentration of a substance at which a lifetime of exposure from 
either: drinking the water, consuming fish from the water, and 
water-related recreation activities; or consuming fish from the 
water, and water-related recreation activities, will represent a 
plausible upper-bound risk of contracting cancer of one in 100,000 
using the exposure assumptions specified in the Methodologies for 
the Development of Human Health Criteria and Values in appendix C of 
this part.
    Human noncancer criterion (HNC). A Human Noncancer Value (HNV) 
for a pollutant that meets the minimum data requirements for Tier I 
specified in appendix C of this part.
    Human noncancer value (HNV). The maximum ambient water 
concentration of a substance at which adverse noncancer effects are 
not likely to occur in the human population from lifetime exposure 
via either: drinking the water, consuming fish from the water, and 
water-related recreation activities; or consuming fish from the 
water, and water-related recreation activities using the 
Methodologies for the Development of Human Health criteria and 
Values in appendix C of this part.
    Linearized multi-stage model. A conservative mathematical model 
for cancer risk assessment. This model fits linear dose-response 
curves to low doses. It is consistent with a no-threshold model of 
carcinogenesis, i.e., exposure to even a very small amount of the 
substance is assumed to produce a finite increased risk of cancer.
    Lowest observed adverse effect level (LOAEL). The lowest tested 
dose or concentration of a substance which resulted in an observed 
adverse effect in exposed test organisms when all higher doses or 
concentrations resulted in the same or more severe effects.
    No observed adverse effect level (NOAEL). The highest tested 
dose or concentration of a substance which resulted in no observed 
adverse effect in exposed test organisms where higher doses or 
concentrations resulted in an adverse effect.
    Quantitative structure activity relationship (OSAR) or structure 
activity relationship (SAR). A mathematical relationship between a 
property (activity) of a chemical and a number of descriptors of the 
chemical. These descriptors are chemical or physical characteristics 
obtained experimentally or predicted from the structure of the 
chemical.
    Relative source contribution (RSC). The factor (percentage) used 
in calculating an HNV or HNC to account for all sources of exposure 
to a contaminant. The RSC reflects the percent of total exposure 
which can be attributed to surface water through water intake and 
fish consumption.
    Risk associated dose (RAD). A dose of a known or presumed 
carcinogenic substance in (mg/kg/day) which, over a lifetime of 
exposure, is estimated to be associated with a plausible upper bound 
incremental cancer risk equal to one in 100,000.
    Slope factor. Also known as q1*, slope factor is the 
incremental rate of cancer development calculated through use of a 
linearized multistage model or other appropriate model. It is 
expressed in (mg/kg/day) of exposure to the chemical in question.
    Threshold effect. An effect of a substance for which there is a 
theoretical or empirically established dose or concentration below 
which the effect does not occur.
    Uncertainty factor (UF). One of several numeric factors used in 
operationally deriving criteria from experimental data to account 
for the quality or quantity of the available data.
    C. Level of Protection. The criteria developed shall provide a 
level of protection likely to be without appreciable risk of 
carcinogenic and/or noncarcinogenic effects. Criteria are a function 
of the level of designated risk or no adverse effect estimation, 
selection of data and exposure assumptions. Ambient criteria for 
single carcinogens shall not be set at a level representing a 
lifetime upper-bound incremental risk greater than one in 100,000 of 
developing cancer using the hazard assessment techniques and 
exposure assumptions described herein. Criteria affording protection 
from noncarcinogenic effects shall be established at levels that, 
taking into account uncertainties, are considered likely to be 
without an appreciable risk of adverse human health effects (i.e., 
acute, subchronic and chronic toxicity including reproductive and 
developmental effects) during a lifetime of exposure, using the risk 
assessment techniques and exposure assumptions described herein.
    D. Two-tiered Classification. Chemical concentration levels in 
surface water protective of human health shall be derived based on 
either a Tier I or Tier II classification. The two Tiers are 
primarily distinguished by the amount of toxicity data available for 
deriving the concentration levels and the quantity and quality of 
data on bioaccumulation.

II. Minimum Data Requirements

    The best available toxicity data on the adverse health effects 
of a chemical and the best data on bioaccumulation factors shall be 
used when developing human health Tier I criteria or Tier II values. 
The best available toxicity data shall include data from well- 
[[Page 15407]] conducted epidemiologic and/or animal studies which 
provide, in the case of carcinogens, an adequate weight of evidence 
of potential human carcinogenicity and, in the case of 
noncarcinogens, a dose-response relationship involving critical 
effects biologically relevant to humans. Such information should be 
obtained from the EPA Integrated Risk Information System (IRIS) 
database, the scientific literature, and other informational 
databases, studies and/or reports containing adverse health effects 
data of adequate quality for use in this procedure. Strong 
consideration shall be given to the most currently available 
guidance provided by IRIS in deriving criteria or values, 
supplemented with any recent data not incorporated into IRIS. When 
deviations from IRIS are anticipated or considered necessary, it is 
strongly recommended that such actions be communicated to the EPA 
Reference Dose (RfD) and/or the Cancer Risk Assessment Verification 
Endeavor (CRAVE) workgroup immediately. The best available 
bioaccumulation data shall include data from field studies and well-
conducted laboratory studies.
    A. Carcinogens. Tier I criteria and Tier II values shall be 
derived using the methodologies described in section III.A of this 
appendix when there is adequate evidence of potential human 
carcinogenic effects for a chemical. It is strongly recommended that 
the EPA classification system for chemical carcinogens, which is 
described in the 1986 EPA Guidelines for Carcinogenic Risk 
Assessment (U.S. EPA, 1986), or future modifications thereto, be 
used in determining whether adequate evidence of potential 
carcinogenic effects exists. Carcinogens are classified, depending 
on the weight of evidence, as either human carcinogens, probable 
human carcinogens, or possible human carcinogens. The human evidence 
is considered inadequate and therefore the chemical cannot be 
classified as a human carcinogen, if one of two conditions exists: 
(a) there are few pertinent data, or (b) the available studies, 
while showing evidence of association, do not exclude chance, bias, 
or confounding and therefore a casual interpretation is not 
credible. The animal evidence is considered inadequate, and 
therefore the chemical cannot be classified as a probable or 
possible human carcinogen, when, because of major qualitative or 
quantitative limitations, the evidence cannot be interpreted as 
showing either the presence or absence of a carcinogenic effect.
    Chemicals are described as ``human carcinogens'' when there is 
sufficient evidence from epidemiological studies to support a causal 
association between exposure to the chemicals and cancer. Chemicals 
described as ``probable human carcinogens'' include chemicals for 
which the weight of evidence of human carcinogenicity based on 
epidemiological studies is limited. Limited human evidence is that 
which indicates that a causal interpretation is credible, but that 
alternative explanations, such as chance, bias, or confounding, 
cannot adequately be excluded. Probable human carcinogens are also 
agents for which there is sufficient evidence from animal studies 
and for which there is inadequate evidence or no data from 
epidemiologic studies. Sufficient animal evidence is data which 
indicates that there is an increased incidence of malignant tumors 
or combined malignant and benign tumors: (a) in multiple species or 
strains; (b) in multiple experiments (e.g., with different routes of 
administration or using different dose levels); or (c) to an unusual 
degree in a single experiment with regard to high incidence, unusual 
site or type of tumor, or early age at onset. Additional evidence 
may be provided by data on dose-response effects, as well as 
information from short-term tests (such as mutagenicity/genotoxicity 
tests which help determine whether the chemical interacts directly 
with DNA) or on chemical structure, metabolism or mode of action.
    ``Possible human carcinogens'' are chemicals with limited 
evidence of carcinogenicity in animals in the absence of human data. 
Limited animal evidence is defined as data which suggests a 
carcinogenic effect but are limited because: (a) The studies involve 
a single species, strain, or experiment and do not meet criteria for 
sufficient evidence (see preceding paragraph); or (b) the 
experiments are restricted by inadequate dosage levels, inadequate 
duration of exposure to the agent, inadequate period of follow-up, 
poor survival, too few animals, or inadequate reporting; or (c) the 
studies indicate an increase in the incidence of benign tumors only. 
More specifically, this group can include a wide variety of 
evidence, e.g., (a) a malignant tumor response in a single well-
conducted experiment that does not meet conditions for sufficient 
evidence, (b) tumor response of marginal statistical significance in 
studies having inadequate design or reporting, (c) benign but not 
malignant tumors with an agent showing no response in a variety of 
short-term tests for mutagenicity, and (d) response of marginal 
statistical significance in a tissue known to have a high or 
variable background rate.
    1. Tier I: Weight of evidence of potential human carcinogenic 
effects sufficient to derive a Tier I HCC shall generally include 
human carcinogens, probable human carcinogens and can include, on a 
case-by-case basis, possible human carcinogens if studies have been 
well-conducted albeit based on limited evidence, when compared to 
studies used in classifying human and probable human carcinogens. 
The decision to use data on a possible human carcinogen for deriving 
Tier I criteria shall be a case-by-case determination. In 
determining whether to derive a Tier I HCC, additional evidence that 
shall be considered includes but is not limited to available 
information on mode of action, such as mutagenicity/genotoxicity 
(determinations of whether the chemical interacts directly with 
DNA), structure activity, and metabolism.
    2. Tier II: Weight of evidence of possible human carcinogenic 
effects sufficient to derive a Tier II human cancer value shall 
include those possible human carcinogens for which there are at a 
minimum, data sufficient for quantitative risk assessment, but for 
which data are inadequate for Tier I criterion development due to a 
tumor response of marginal statistical significance or inability to 
derive a strong dose-response relationship. In determining whether 
to derive Tier II human cancer values, additional evidence that 
shall be considered includes but is not limited to available 
information on mode of action such as mutagenicity/genotoxicity 
(determinations of whether the chemical interacts directly with 
DNA), structure activity and metabolism. As with the use of data on 
possible human carcinogens in developing Tier I criteria, the 
decision to use data on possible human carcinogens to derive Tier II 
values shall be made on a case-by-case basis.
    B. Noncarcinogens. All available toxicity data shall be 
evaluated considering the full range of possible health effects of a 
chemical, i.e., acute/subacute, chronic/subchronic and reproductive/
developmental effects, in order to best describe the dose-response 
relationship of the chemical, and to calculate human noncancer 
criteria and values which will protect against the most sensitive 
endpoint(s) of toxicity. Although it is desirable to have an 
extensive database which considers a wide range of possible adverse 
effects, this type of data exists for a very limited number of 
chemicals. For many others, there is a range in quality and quantity 
of data available. To assure minimum reliability of criteria and 
values, it is necessary to establish a minimum database with which 
to develop Tier I criteria or Tier II values. The following 
represent the minimum data sets necessary for this procedure.
    1. Tier I: The minimum data set sufficient to derive a Tier I 
human HNC shall include at least one well-conducted epidemiologic 
study or animal study. A well-conducted epidemiologic study for a 
Tier I HNC must quantify exposure level(s) and demonstrate positive 
association between exposure to a chemical and adverse effect(s) in 
humans. A well-conducted study in animals must demonstrate a dose 
response relationship involving one or more critical effect(s) 
biologically relevant to humans. (For example, study results from an 
animal whose pharmacokinetics and toxicokinetics match those of a 
human would be considered most biologically relevant.) Ideally, the 
duration of a study should span multiple generations of exposed test 
species or at least a major portion of the lifespan of one 
generation. This type of data is currently very limited. By the use 
of uncertainty adjustments, shorter term studies (such as 90-day 
subchronic studies) with evaluation of more limited effect(s) may be 
used to extrapolate to longer exposures or to account for a variety 
of adverse effects. For Tier I criteria developed pursuant to this 
procedure, such a limited study must be conducted for at least 90 
days in rodents or 10 percent of the lifespan of other appropriate 
test species and demonstrate a no observable adverse effect level 
(NOAEL). Chronic studies of one year or longer in rodents or 50 
percent of the lifespan or greater in other appropriate test species 
that demonstrate a lowest observable adverse effect level (LOAEL) 
may be sufficient for use in Tier I criterion derivation if the 
effects observed at the LOAEL were relatively mild and reversible as 
compared to [[Page 15408]] effects at higher doses. This does not 
preclude the use of a LOAEL from a study (of chronic duration) with 
only one or two doses if the effects observed appear minimal when 
compared to effect levels observed at higher doses in other studies.
    2. Tier II: When the minimum data for deriving Tier I criteria 
are not available to meet the Tier I data requirements, a more 
limited database may be considered for deriving Tier II values. As 
with Tier I criteria, all available data shall be considered and 
ideally should address a range of adverse health effects with 
exposure over a substantial portion of the lifespan (or multiple 
generations) of the test species. When such data are lacking it may 
be necessary to rely on less extensive data in order to establish a 
Tier II value. With the use of appropriate uncertainty factors to 
account for a less extensive database, the minimum data sufficient 
to derive a Tier II value shall include a NOAEL from at least one 
well-conducted short-term repeated dose study. This study shall be 
of at least 28 days duration, in animals demonstrating a dose-
response, and involving effects biologically relevant to humans. 
Data from studies of longer duration (greater than 28 days) and 
LOAELs from such studies (greater than 28 days) may be more 
appropriate in some cases for derivation of Tier II values. Use of a 
LOAEL should be based on consideration of the following information: 
severity of effect, quality of the study and duration of the study.
    C. Bioaccumulation factors (BAFs).
    1. Tier I for Carcinogens and Noncarcinogens: To be considered a 
Tier I cancer or noncancer human health criterion, along with 
satisfying the minimum toxicity data requirements of sections II.A.1 
and II.B.1 of this appendix, a chemical must have the following 
minimum bioaccumulation data. For all organic chemicals either: (a) 
a field-measured BAF; (b) a BAF derived using the BSAF methodology; 
or (c) a chemical with a BAF less than 125 regardless of how the BAF 
was derived. For all inorganic chemicals, including organometals 
such as mercury, either: (a) a field-measured BAF or (b) a 
laboratory-measured BCF.
    2. Tier II for Carcinogens and Noncarcinogens: A chemical is 
considered a Tier II cancer or noncancer human health value if it 
does not meet either the minimum toxicity data requirements of 
sections II.A.1 and II.B.1 of this appendix or the minimum 
bioaccumulation data requirements of section II.C.1 of this 
appendix.

III. Principles for Development of Tier I Criteria or Tier II Values

    The fundamental components of the procedure to calculate Tier I 
criteria or Tier II values are the same. However, certain of the 
aspects of the procedure designed to account for short-duration 
studies or other limitations in data are more likely to be relevant 
in deriving Tier II values than Tier I criteria.
    A. Carcinogens.
    1. A non-threshold mechanism of carcinogenesis shall be assumed 
unless biological data adequately demonstrate the existence of a 
threshold on a chemical-specific basis.
    2. All appropriate human epidemiologic data and animal cancer 
bioassay data shall be considered. Data specific to an 
environmentally appropriate route of exposure shall be used. Oral 
exposure should be used preferentially over dermal and inhalation 
since, in most cases, the exposure routes of greatest concern are 
fish consumption and drinking water/incidental ingestion. The risk 
associated dose shall be set at a level corresponding to an 
incremental cancer risk of one in 100,000. If acceptable human 
epidemiologic data are available for a chemical, it shall be used to 
derive the risk associated dose. If acceptable human epidemiologic 
data are not available, the risk associated dose shall be derived 
from available animal bioassay data. Data from a species that is 
considered most biologically relevant to humans (i.e., responds most 
like humans) is preferred where all other considerations regarding 
quality of data are equal. In the absence of data to distinguish the 
most relevant species, data from the most sensitive species tested, 
i.e., the species showing a carcinogenic effect at the lowest 
administered dose, shall generally be used.
    3. When animal bioassay data are used and a non-threshold 
mechanism of carcinogenicity is assumed, the data are fitted to a 
linearized multistage computer model (e.g., Global '86 or equivalent 
model). Global '86 is the linearized multistage model, derived by 
Howe, Crump and Van Landingham (1986), which EPA uses to determine 
cancer potencies. The upper-bound 95 percent confidence limit on 
risk (or, the lower 95 percent confidence limit on dose) at the one 
in 100,000 risk level shall be used to calculate a risk associated 
dose (RAD). Other models, including modifications or variations of 
the linear multistage model which are more appropriate to the 
available data may be used where scientifically justified.
    4. If the duration of the study is significantly less than the 
natural lifespan of the test animal, the slope may be adjusted on a 
case-by-case basis to compensate for latent tumors which were not 
expressed (e.g., U.S. EPA, 1980) In the absence of alternative 
approaches which compensate for study durations significantly less 
than lifetime, the permitting authority may use the process 
described in the 1980 National Guidelines (see 45 FR 79352).
    5. A species scaling factor shall be used to account for 
differences between test species and humans. It shall be assumed 
that milligrams per surface area per day is an equivalent dose 
between species (U.S. EPA, 1986). All doses presented in mg/kg 
bodyweight will be converted to an equivalent surface area dose by 
raising the mg/kg dose to the 2/3 power. However, if adequate 
pharmacokinetic and metabolism studies are available, these data may 
be factored into the adjustment for species differences on a case-
by-case basis.
    6. Additional data selection and adjustment decisions must also 
be made in the process of quantifying risk. Consideration must be 
given to tumor selection for modeling, e.g., pooling estimates for 
multiple tumor types and identifying and combining benign and 
malignant tumors. All doses shall be adjusted to give an average 
daily dose over the study duration. Adjustments in the rate of tumor 
response must be made for early mortality in test species. The 
goodness-of-fit of the model to the data must also be assessed.
    7. When a linear, non-threshold dose response relationship is 
assumed, the RAD shall be calculated using the following equation:
[GRAPHIC][TIFF OMITTED]TR23MR95.114


Where:

RAD=risk associated dose in milligrams of toxicant per kilogram body 
weight per day (mg/kg/day).
0.00001 (1 x 10-5)=incremental risk of developing cancer equal 
to one in 100,000.
q1*=slope factor (mg/kg/day)-1.

    8. If human epidemiologic data and/or other biological data 
(animal) indicate that a chemical causes cancer via a threshold 
mechanism, the risk associated dose may, on a case-by-case basis, be 
calculated using a method which assumes a threshold mechanism is 
operative.
    B. Noncarcinogens.
    1. Noncarcinogens shall generally be assumed to have a threshold 
dose or concentration below which no adverse effects should be 
observed. Therefore, the Tier I criterion or Tier II value is the 
maximum water concentration of a substance at or below which a 
lifetime exposure from drinking the water, consuming fish caught in 
the water, and ingesting water as a result of participating in 
water-related recreation activities is likely to be without 
appreciable risk of deleterious effects.
    For some noncarcinogens, there may not be a threshold dose below 
which no adverse effects should be observed. Chemicals acting as 
genotoxic teratogens and germline mutagens are thought to possibly 
produce reproductive and/or developmental effects via a genetically 
linked mechanism which may have no threshold. Other chemicals also 
may not demonstrate a threshold. Criteria for these types of 
chemicals will be established on a case-by-case basis using 
appropriate assumptions reflecting the likelihood that no threshold 
exists.
    2. All appropriate human and animal toxicologic data shall be 
reviewed and evaluated. To the maximum extent possible, data most 
specific to the environmentally relevant route of exposure shall be 
used. Oral exposure data should be used preferentially over dermal 
and inhalation since, in most cases, the exposure routes of greatest 
concern are fish consumption and drinking water/incidental 
ingestion. When acceptable human data are not available (e.g., well-
conducted epidemiologic studies), animal data from species most 
biologically relevant to humans shall be used. In the absence of 
data to distinguish the most relevant species, data from the most 
sensitive animal species tested, i.e., the species showing a toxic 
effect at the lowest administered dose (given a relevant route of 
exposure), should generally be used. [[Page 15409]] 
    3. Minimum data requirements are specified in section II.B of 
this appendix. The experimental exposure level representing the 
highest level tested at which no adverse effects were demonstrated 
(NOAEL) from studies satisfying the provisions of section II.B of 
this appendix shall be used for criteria calculations. In the 
absence of a NOAEL, the LOAEL from studies satisfying the provisions 
of section II.B of this appendix may be used if it is based on 
relatively mild and reversible effects.
    4. Uncertainty factors shall be used to account for the 
uncertainties in predicting acceptable dose levels for the general 
human population based upon experimental animal data or limited 
human data.
    a. An uncertainty factor of 10 shall generally be used when 
extrapolating from valid experimental results from studies on 
prolonged exposure to average healthy humans. This 10-fold factor is 
used to protect sensitive members of the human population.
    b. An uncertainty factor of 100 shall generally be used when 
extrapolating from valid results of long-term studies on 
experimental animals when results of studies of human exposure are 
not available or are inadequate. In comparison to a, above, this 
represents an additional 10-fold uncertainty factor in extrapolating 
data from the average animal to the average human.
    c. An uncertainty factor of up to 1000 shall generally be used 
when extrapolating from animal studies for which the exposure 
duration is less than chronic, but greater than subchronic (e.g., 90 
days or more in length), or when other significant deficiencies in 
study quality are present, and when useful long-term human data are 
not available. In comparison to b, above, this represents an 
additional UF of up to 10-fold for less than chronic, but greater 
than subchronic, studies.
    d. An UF of up to 3000 shall generally be used when 
extrapolating from animal studies for which the exposure duration is 
less than subchronic (e.g., 28 days). In comparison to b above, this 
represents an additional UF of up to 30-fold for less than 
subchronic studies (e.g., 28-day). The level of additional 
uncertainty applied for less than chronic exposures depends on the 
duration of the study used relative to the lifetime of the 
experimental animal.
    e. An additional UF of between one and ten may be used when 
deriving a criterion from a LOAEL. This UF accounts for the lack of 
an identifiable NOAEL. The level of additional uncertainty applied 
may depend upon the severity and the incidence of the observed 
adverse effect.
    f. An additional UF of between one and ten may be applied when 
there are limited effects data or incomplete sub-acute or chronic 
toxicity data (e.g., reproductive/developmental data). The level of 
quality and quantity of the experimental data available as well as 
structure-activity relationships may be used to determine the factor 
selected.
    g. When deriving an UF in developing a Tier I criterion or Tier 
II value, the total uncertainty, as calculated following the 
guidance of sections 4.a through f, cited above, shall not exceed 
10,000 for Tier I criteria and 30,000 for Tier II values.
    5. All study results shall be converted, as necessary, to the 
standard unit for acceptable daily exposure of milligrams of 
toxicant per kilogram of body weight per day (mg/kg/day). Doses 
shall be adjusted for continuous exposure (i.e., seven days/week, 24 
hours/day, etc.).
    C. Criteria and Value Derivation.
    1. Standard Exposure Assumptions. The following represent the 
standard exposure assumptions used to calculate Tier I criteria and 
Tier II values for carcinogens and noncarcinogens. Higher levels of 
exposure may be assumed by States and Tribes pursuant to Clean Water 
Act (CWA) section 510, or where appropriate in deriving site-
specific criteria pursuant to procedure 1 in appendix F to part 132.
    BW = body weight of an average human (BW = 70kg).
    WCd = per capita water consumption (both drinking and 
incidental exposure) for surface waters classified as public water 
supplies = two liters/day.
          --or--
    WCr = per capita incidental daily water ingestion for 
surface waters not used as human drinking water sources = 0.01 
liters/day.
    FC = per capita daily consumption of regionally caught 
freshwater fish = 0.015kg/day (0.0036 kg/day for trophic level 3 and 
0.0114 kg/day for trophic level 4).
    BAF = bioaccumulation factor for trophic level 3 and trophic 
level 4, as derived using the BAF methodology in appendix B to part 
132.
    2. Carcinogens. The Tier I human cancer criteria or Tier II 
values shall be calculated as follows:
[GRAPHIC][TIFF OMITTED]TR23MR95.115


Where:

HCV=Human Cancer Value in milligrams per liter (mg/L).
RAD=Risk associated dose in milligrams toxicant per kilogram body 
weight per day (mg/kg/day) that is associated with a lifetime 
incremental cancer risk equal to one in 100,000.
BW=weight of an average human (BW=70 kg).
WCd=per capita water consumption (both drinking and incidental 
exposure) for surface waters classified as public water supplies=two 
liters/day.
      or
WCr=per capita incidental daily water ingestion for surface 
waters not used as human drinking water sources=0.01 liters/day.
FCTL3=mean consumption of trophic level 3 of regionally caught 
freshwater fish=0.0036 kg/day.
FCTL4=mean consumption of trophic level 4 of regionally caught 
freshwater fish=0.0114 kg/day.
BAFHHTL3=bioaccumulation factor for trophic level 3 fish, 
as derived using the BAF methodology in appendix B to part 132.
BAFHHTL4=bioaccumulation factor for trophic level 4 fish, 
as derived using the BAF methodology in appendix B to part 132.

    3. Noncarcinogens. The Tier I human noncancer criteria or Tier 
II values shall be calculated as follows:
[GRAPHIC][TIFF OMITTED]TR23MR95.116


Where:

HNV=Human noncancer value in milligrams per liter (mg/L).
ADE=Acceptable daily exposure in milligrams toxicant per kilogram 
body weight per day (mg/kg/day).
RSC=Relative source contribution factor of 0.8. An RSC derived from 
actual exposure data may be developed using the methodology outlined 
by the 1980 National Guidelines (see 45 FR 79354).
BW=weight of an average human (BW=70 kg).
WCd=per capita water consumption (both drinking and incidental 
exposure) for surface waters classified as public water supplies=two 
liters/day.
      or
WCr=per capita incidental daily water ingestion for surface 
waters not used as human drinking water sources=0.01 liters/
day. [[Page 15410]] 
FCTL3=mean consumption of trophic level 3 fish by regional 
sport fishers of regionally caught freshwater fish=0.0036 kg/day.
FCTL4=mean consumption of trophic level 4 fish by regional 
sport fishers of regionally caught freshwater fish=0.0114 kg/day.
BAFHHTL3=human health bioaccumulation factor for edible 
portion of trophic level 3 fish, as derived using the BAF 
methodology in appendix B to part 132.
BAFHHTL4=human health bioaccumulation factor for edible 
portion of trophic level 4 fish, as derived using the BAF 
methodology in appendix B to part 132.

IV. References

    A. Howe, R.B., K.S. Crump and C. Van Landingham. 1986. Computer 
Program to Extrapolate Quantitative Animal Toxicity Data to Low 
Doses. Prepared for EPA under subcontract #2-251U-2745 to Research 
Triangle Institute.
    B. U.S. Environmental Protection Agency. 1980. Water Quality 
Criteria Availability, Appendix C Guidelines and Methodology Used in 
the Preparation of Health Effects Assessment Chapters of the Consent 
Decree Water Quality Criteria Documents. Available from U.S. 
Environmental Protection Agency, Office of Water Resource Center 
(WH-550A), 401 M St., SW., Washington, DC 20460.
    C. U.S. Environmental Protection Agency. 1986. Guidelines for 
Carcinogen Risk Assessment. Available from U.S. Environmental 
Protection Agency, Office of Water Resource Center (WH-550A), 401 M 
St., SW., Washington, DC 20460.

Appendix D to Part 132--Great Lakes Water Quality Initiative 
Methodology for the Development of Wildlife Criteria

    Great Lakes States and Tribes shall adopt provisions consistent 
with (as protective as) this appendix.

I. Introduction

    A. A Great Lakes Water Quality Wildlife Criterion (GLWC) is the 
concentration of a substance which is likely to, if not exceeded, 
protect avian and mammalian wildlife populations inhabiting the 
Great Lakes basin from adverse effects resulting from the ingestion 
of water and aquatic prey taken from surface waters of the Great 
Lakes System. These criteria are based on existing toxicological 
studies of the substance of concern and quantitative information 
about the exposure of wildlife species to the substance (i.e., food 
and water consumption rates). Since toxicological and exposure data 
for individual wildlife species are limited, a GLWC is derived using 
a methodology similar to that used to derive noncancer human health 
criteria (Barnes and Dourson, 1988; NAS, 1977; NAS, 1980; U.S. EPA, 
1980). Separate avian and mammalian values are developed using 
taxonomic class-specific toxicity data and exposure data for five 
representative Great Lakes basin wildlife species. The wildlife 
species selected are representative of avian and mammalian species 
resident in the Great Lakes basin which are likely to experience the 
highest exposures to bioaccumulative contaminants through the 
aquatic food web; they are the bald eagle, herring gull, belted 
kingfisher, mink, and river otter.
    B. This appendix establishes a methodology which is required 
when developing Tier I wildlife criteria for bioaccumulative 
chemicals of concern (BCCs). The use of the equation provided in the 
methodology is encouraged, but not required, for the development of 
Tier I criteria or Tier II values for pollutants other than those 
identified in Table 6-A for which Tier I criteria or Tier II values 
are determined to be necessary for the protection of wildlife in the 
Great Lakes basin. A discussion of the methodology for deriving Tier 
II values can be found in the Great Lakes Water Quality Initiative 
Technical Support Document for Wildlife Criteria (Wildlife TSD).
    C. In the event that this methodology is used to develop 
criteria for pollutants other than BCCs, or in the event that the 
Tier II methodology described in the Wildlife TSD is used to derive 
Tier II values, the methodology for deriving bioaccumulation factors 
under appendix B to part 132 must be used in either derivation. For 
chemicals which do not biomagnify to the extent of BCCs, it may be 
appropriate to select different representative species which are 
better examples of species with the highest exposures for the given 
chemical. The equation presented in this methodology, however, is 
still encouraged. In addition, procedure 1 of appendix F of this 
part describes the procedures for calculating site-specific wildlife 
criteria.
    D. The term ``wildlife value'' (WV) is used to denote the value 
for each representative species which results from using the 
equation presented below, the value obtained from averaging species 
values within a class, or any value derived from application of the 
site-specific procedure provided in procedure 1 of appendix F of 
this part. The WVs calculated for the representative species are 
used to calculate taxonomic class-specific WVs. The WV is the 
concentration of a substance which, if not exceeded, should better 
protect the taxon in question.
    E. ``Tier I wildlife criterion,'' or ``Tier I criterion'' is 
used to denote the number derived from data meeting the Tier I 
minimum database requirements, and which will be protective of the 
two classes of wildlife. It is synonymous with the term ``GLWC,'' 
and the two are used interchangeably.

II. Calculation of Wildlife Values for Tier I Criteria

    Table 4 of Part 132 and Table D-1 of this appendix contain 
criteria calculated by EPA using the methodology provided below.
    A. Equation for Avian and Mammalian Wildlife Values. Tier I 
wildlife values for the pollutants designated BCCs pursuant to part 
132 are to be calculated using the equation presented below.
[GRAPHIC][TIFF OMITTED]TR23MR95.117


Where:
WV=Wildlife Value in milligrams of substance per liter (mg/L).
TD=Test Dose (TD) in milligrams of substance per kilograms per day 
(mg/kg-d) for the test species. This shall be either a NOAEL or a 
LOAEL.
UFA=Uncertainty Factor (UF) for extrapolating toxicity data 
across species (unitless). A species-specific UF shall be selected 
and applied to each representative species, consistent with the 
equation.
UFS=UF for extrapolating from subchronic to chronic exposures 
(unitless).
UFL=UF for LOAEL to NOAEL extrapolations (unitless).
Wt=Average weight in kilograms (kg) for the representative species.
W=Average daily volume of water consumed in liters per day (L/d) by 
the representative species.
FTLi=Average daily amount of food consumed from trophic level i 
in kilograms per day (kg/d) by the representative species.
BAFWLTLi=Bioaccumulation factor (BAF) for wildlife food in 
trophic level i in liters per kilogram (L/kg), developed using the 
BAF methodology in appendix B to part 132, Methodology for 
Development of Bioaccumulation Factors. For consumption of 
piscivorous birds by other birds (e.g., herring gull by eagles), the 
BAF is derived by multiplying the trophic level 3 BAF for fish by a 
biomagnification factor to account for the biomagnification from 
fish to the consumed birds.

    B. Identification of Representative Species for Protection. For 
bioaccumulative chemicals, piscivorous species are identified as the 
focus of concern for wildlife criteria development in the Great 
Lakes. An analysis of known or estimated exposure components for 
avian and mammalian wildlife species is presented in the Wildlife 
TSD. This analysis identifies three avian species (eagle, kingfisher 
and herring gull) and two mammalian species (mink and otter) as 
representative species for protection. The TD obtained from toxicity 
data for each taxonomic class is used to calculate WVs for each of 
the five representative species.
    C. Calculation of Avian and Mammalian Wildlife Values and GLWC 
Derivation. The avian WV is the geometric mean of the WVs calculated 
for the three representative avian species. The mammalian WV is the 
geometric mean of the WVs calculated for the two representative 
mammalian species. The lower of the mammalian and avian WVs must be 
selected as the GLWC.

III. Parameters of the Effect Component of the Wildlife Criteria 
Methodology

    A. Definitions. The following definitions provide additional 
specificity and guidance in the evaluation of toxicity data and the 
application of this methodology.
    Acceptable endpoints. For the purpose of wildlife criteria 
derivation, acceptable subchronic and chronic endpoints are those 
which affect reproductive or developmental success, organismal 
viability or growth, or any other endpoint which is, or is directly 
related to, parameters that influence population dynamics. 
[[Page 15411]] 
    Chronic effect. An adverse effect that is measured by assessing 
an acceptable endpoint, and results from continual exposure over 
several generations, or at least over a significant part of the test 
species' projected life span or life stage.
    Lowest-observed-adverse-effect-level (LOAEL). The lowest tested 
dose or concentration of a substance which resulted in an observed 
adverse effect in exposed test organisms when all higher doses or 
concentrations resulted in the same or more severe effects.
    No-observed-adverse-effect-level (NOAEL). The highest tested 
dose or concentration of a substance which resulted in no observed 
adverse effect in exposed test organisms where higher doses or 
concentrations resulted in an adverse effect.
    Subchronic effect. An adverse effect, measured by assessing an 
acceptable endpoint, resulting from continual exposure for a period 
of time less than that deemed necessary for a chronic test.
    B. Minimum Toxicity Database for Tier I Criteria Development. A 
TD value is required for criterion calculation. To derive a Tier I 
criterion for wildlife, the data set shall provide enough data to 
generate a subchronic or chronic dose-response curve for any given 
substance for both mammalian and avian species. In reviewing the 
toxicity data available which meet the minimum data requirements for 
each taxonomic class, the following order of preference shall be 
applied to select the appropriate TD to be used for calculation of 
individual WVs. Data from peer-reviewed field studies of wildlife 
species take precedence over other types of studies, where such 
studies are of adequate quality. An acceptable field study must be 
of subchronic or chronic duration, provide a defensible, chemical-
specific dose-response curve in which cause and effect are clearly 
established, and assess acceptable endpoints as defined in this 
document. When acceptable wildlife field studies are not available, 
or determined to be of inadequate quality, the needed toxicity 
information may come from peer-reviewed laboratory studies. When 
laboratory studies are used, preference shall be given to laboratory 
studies with wildlife species over traditional laboratory animals to 
reduce uncertainties in making interspecies extrapolations. All 
available laboratory data and field studies shall be reviewed to 
corroborate the final GLWC, to assess the reasonableness of the 
toxicity value used, and to assess the appropriateness of any UFs 
which are applied. When evaluating the studies from which a test 
dose is derived in general, the following requirements must be met:
    1. The mammalian data must come from at least one well-conducted 
study of 90 days or greater designed to observe subchronic or 
chronic effects as defined in this document.
    2. The avian data must come from at least one well-conducted 
study of 70 days or greater designed to observe subchronic or 
chronic effects as defined in this document.
    3. In reviewing the studies from which a TD is derived for use 
in calculating a WV, studies involving exposure routes other than 
oral may be considered only when an equivalent oral daily dose can 
be estimated and technically justified because the criteria 
calculations are based on an oral route of exposure.
    4. In assessing the studies which meet the minimum data 
requirements, preference should be given to studies which assess 
effects on developmental or reproductive endpoints because, in 
general, these are more important endpoints in ensuring that a 
population's productivity is maintained. The Wildlife TSD provides 
additional discussion on the selection of an appropriate toxicity 
study.
    C. Selection of TD Data. In selecting data to be used in the 
derivation of WVs, the evaluation of acceptable endpoints, as 
defined in Section III.A of this appendix, will be the primary 
selection criterion. All data not part of the selected subset may be 
used to assess the reasonableness of the toxicity value and the 
appropriateness of the Ufs which are applied.
    1. If more than one TD value is available within a taxonomic 
class, based on different endpoints of toxicity, that TD, which is 
likely to reflect best potential impacts to wildlife populations 
through resultant changes in mortality or fecundity rates, shall be 
used for the calculation of WVs.
    2. If more than one TD is available within a taxonomic class, 
based on the same endpoint of toxicity, the TD from the most 
sensitive species shall be used.
    3. If more than one TD based on the same endpoint of toxicity is 
available for a given species, the TD for that species shall be 
calculated using the geometric mean of those TDs.
    D. Exposure Assumptions in the Determination of the TD. 1. In 
those cases in which a TD is available in units other than 
milligrams of substance per kilograms per day (mg/kg/d), the 
following procedures shall be used to convert the TD to the 
appropriate units prior to calculating a WV.
    2. If the TD is given in milligrams of toxicant per liter of 
water consumed by the test animals (mg/L), the TD shall be 
multiplied by the daily average volume of water consumed by the test 
animals in liters per day (L/d) and divided by the average weight of 
the test animals in kilograms (kg).
    3. If the TD is given in milligrams of toxicant per kilogram of 
food consumed by the test animals (mg/kg), the TD shall be 
multiplied by the average amount of food in kilograms consumed daily 
by the test animals (kg/d) and divided by the average weight of the 
test animals in kilograms (kg).
    E. Drinking and Feeding Rates. 1. When drinking and feeding 
rates and body weight are needed to express the TD in milligrams of 
substance per kilograms per day (mg/kg/d), they are obtained from 
the study from which the TD was derived. If not already determined, 
body weight, and drinking and feeding rates are to be converted to a 
wet weight basis.
    2. If the study does not provide the needed values, the values 
shall be determined from appropriate scientific literature. For 
studies done with domestic laboratory animals, either the Registry 
of Toxic Effects of Chemical Substances (National Institute for 
Occupational Safety and Health, the latest edition, Cincinnati, OH), 
or Recommendations for and Documentation of Biological Values for 
Use in Risk Assessment (U.S. EPA, 1988) should be consulted. When 
these references do not contain exposure information for the species 
used in a given study, either the allometric equations from Calder 
and Braun (1983) and Nagy (1987), which are presented below, or the 
exposure estimation methods presented in Chapter 4 of the Wildlife 
Exposure Factors Handbook (U.S. EPA, 1993), should be applied to 
approximate the needed feeding or drinking rates. Additional 
discussion and recommendations are provided in the Wildlife TSD. The 
choice of the methods described above is at the discretion of the 
State or Tribe.
    3. For mammalian species, the general allometric equations are:

    a. F = 0.0687  x  (Wt)0.82

Where:

F = Feeding rate of mammalian species in kilograms per day (kg/d) 
dry weight.
Wt = Average weight in kilograms (kg) of the test animals.

    b. W = 0.099  x  (Wt)0.90

Where:

W = Drinking rate of mammalian species in liters per day (L/d).
 Wt = Average weight in kilograms (kg) of the test animals.
    4. For avian species, the general allometric equations are:

    a. F = 0.0582 (Wt)0.65

Where:

F = Feeding rate of avian species in kilograms per day (kg/d) dry 
weight.
Wt = Average weight in kilograms (kg) of the test animals.

    b. W = 0.059  x  (Wt)0.67

Where:

W = Drinking rate of avian species in liters per day (L/d).
Wt = Average weight in kilograms (kg) of the test animals.
    F. LOAEL to NOAEL Extrapolations (UFL). In those cases in 
which a NOAEL is unavailable as the TD and a LOAEL is available, the 
LOAEL may be used to estimate the NOAEL. If used, the LOAEL shall be 
divided by an UF to estimate a NOAEL for use in deriving WVs. The 
value of the UF shall not be less than one and should not exceed 10, 
depending on the dose-response curve and any other available data, 
and is represented by UFL in the equation expressed in Section 
II.A of this appendix. Guidance for selecting an appropriate 
UFL, based on a review of available wildlife toxicity data, is 
available in the Wildlife TSD.
    G. Subchronic to Chronic Extrapolations (USS). In instances 
where only subchronic data are available, the TD may be derived from 
subchronic data. In such cases, the TD shall be divided by an UF to 
extrapolate from subchronic to chronic levels. The value of the UF 
shall not be less than one and should not exceed 10, and is 
represented by UFS in the equation expressed in Section II.A of 
this appendix. This factor is to be used when assessing highly 
bioaccumulative substances where toxicokinetic considerations 
suggest that a bioassay of limited length 
[[Page 15412]] underestimates chronic effects. Guidance for 
selecting an appropriate UFS, based on a review of available 
wildlife toxicity data, is available in the Wildlife TSD.
    H. Interspecies Extrapolations (UFA). 1. The selection of 
the UFA shall be based on the available toxicological data and 
on available data concerning the physicochemical, toxicokinetic, and 
toxicodynamic properties of the substance in question and the amount 
and quality of available data. This value is an UF that is intended 
to account for differences in toxicological sensitivity among 
species. Guidance for selecting an appropriate UFA, based on a 
review of available wildlife toxicity data, is available in the 
Wildlife TSD. Additional discussion of an interspecies UF located in 
appendix A to the Great Lakes Water Quality Initiative Technical 
Support Document for Human Health Criteria may be useful in 
determining the appropriate value for UFA.
    2. For the derivation of Tier I criteria, a UFA shall not 
be less than one and should not exceed 100, and shall be applied to 
each of the five representative species, based on existing data and 
best professional judgment. The value of UFA may differ for 
each of the representative species.
    3. For Tier I wildlife criteria, the UFA shall be used only 
for extrapolating toxicity data across species within a taxonomic 
class, except as provided below. The Tier I UFA is not intended 
for interclass extrapolations because of the poorly defined 
comparative toxicokinetic and toxicodynamic parameters between 
mammals and birds. However, an interclass extrapolation employing a 
UFA may be used for a given chemical if it can be supported by 
a validated biologically-based dose-response model or by an analysis 
of interclass toxicological data, considering acceptable endpoints, 
for a chemical analog that acts under the same mode of toxic action.

IV. Parameters of the Exposure Component of the Wildlife Criteria 
Methodology

    A. Drinking and Feeding Rates of Representative Species. The 
body weights (Wt), feeding rates (FTli), drinking rates (W), 
and trophic level dietary composition (as food ingestion rate and 
percent in diet) for each of the five representative species are 
presented in Table D-2 of this appendix. Guidance on incorporating 
the non-aquatic portion of the bald eagle and mink diets in the 
criteria calculations is available in the Wildlife TSD.
    B. BAFs. The Methodology for Development of Bioaccumulation 
Factors is presented in appendix B to part 132. Trophic level 3 and 
4 BAFs are used to derive Wvs because these are the trophic levels 
at which the representative species feed.

V. References

    A. Barnes, D.G. and M. Dourson. 1988. Reference Dose (RfD): 
Description and Use in Health Risk Assessments. Regul. Toxicol. 
Pharmacol. 8:471-486.
    B. Calder III, W.A. and E.J. Braun. 1983. Scaling of Osmotic 
Regulation in Mammals and Birds. American Journal of Physiology. 
244:601-606.
    C. Nagy, K.A. 1987. Field Metabolic Rate and Food Requirement 
Scaling in Mammals and Birds. Ecological Monographs. 57(2):111-128.
    D. National Academy of Sciences. 1977. Chemical Contaminants: 
Safety and Risk Assessment, in Drinking Water and Health, Volume 1. 
National Academy Press.
    E. National Academy of Sciences. 1980. Problems of Risk 
Estimation, in Drinking Water and Health, Volume 3. National Academy 
Press.
    F. National Institute for Occupational Safety and Health. Latest 
edition. Registry of Toxic Effects of Chemical Substances. Division 
of Standards Development and Technology Transfer. (Available only on 
microfiche or as an electronic database.)
    G. U.S. EPA. 1980. Appendix C. Guidelines and Methodology Used 
in the Preparation of Health Effect Assessment Chapters of the 
Consent Decree Water Criteria Documents, pp. 79347-79357 in Water 
Quality Criteria Documents; Availability. Available from U.S. 
Environmental Protection Agency, Office of Water Resource Center 
(WH-550A), 401 M St. SW, Washington, DC 20460.
    H. U.S. EPA. 1988. Recommendations for, and documentation of, 
biological values for use in risk assessment. NTIS-PB88-179874.
    I. U.S. EPA. 1993. Wildlife Exposure Factors Handbook, Volumes I 
and II. EPA/600/R-93/187a and b.

Tables to Appendix D to Part 132

            Table D-1.--Tier I Great Lakes Wildlife Criteria            
------------------------------------------------------------------------
                                                              Criterion 
                         Substance                          (g/
                                                                 L)     
------------------------------------------------------------------------
DDT & Metabolites.........................................  1.1E-5      
Mercury...................................................  1.3E-3      
PCBs (total)..............................................  7.4E-5      
2,3,7,8-TCDD..............................................  3.1E-9      
------------------------------------------------------------------------


          Table D-2.--Exposure Parameters for the Five Representative Species Identified for Protection         
----------------------------------------------------------------------------------------------------------------
                                             Water                                                              
                              Adult body   ingestion    Food ingestion rate of prey     Trophic level of prey   
       Species (units)          weight      rate (L/    in each trophic level (kg/        (percent of diet)     
                                 (kg)         day)                 day)                                         
----------------------------------------------------------------------------------------------------------------
Mink........................        0.80        0.081  TL3: 0.159; Other: 0.0177...  TL3: 90; Other: 10.        
Otter.......................        7.4         0.600  TL3: 0.977; TL4: 0.244......  TL3: 80; TL4: 20.          
Kingfisher..................        0.15        0.017  TL3: 0.0672.................  TL3: 100.                  
Herring gull................        1.1         0.063  TL3: 0.192; TL4: 0.0480.....  Fish: 90--TL3: 80; TL4: 20.
                                                       Other: 0.0267...............  Other: 10.                 
Bald eagle..................        4.6         0.160  TL3: 0.371; TL4: 0.0929.....  Fish: 92--TL3: 80; TL4: 20.
                                                       PB: 00283; Other: 0.0121....  Birds: 8--PB: 70; non-     
                                                                                      aquatic: 30.              
----------------------------------------------------------------------------------------------------------------
Note: TL3=trophic level three fish;  TL4=trophic level four fish;  PB=piscivorous birds;  Other=non-aquatic     
  birds and mammals.                                                                                            

Appendix E to Part 132--Great Lakes Water Quality Initiative 
Antidegradation Policy

    Great Lakes States and Tribes shall adopt provisions consistent 
with (as protective as) appendix E to part 132.
    The State or Tribe shall adopt an antidegradation standard 
applicable to all waters of the Great Lakes System and identify the 
methods for implementing such a standard. Consistent with 40 CFR 
131.12, an acceptable antidegradation standard and implementation 
procedure are required elements of a State's or Tribe's water 
quality standards program. Consistent with 40 CFR 131.6, a complete 
water quality standards submission needs to include both an 
antidegradation standard and antidegradation implementation 
procedures. At a minimum, States and Tribes shall adopt provisions 
in their antidegradation standard and implementation methods 
consistent with sections I, II, III and IV of this appendix, 
applicable to pollutants identified as bioaccumulative chemicals of 
concern (BCCs).

I. Antidegradation Standard

    This antidegradation standard shall be applicable to any action 
or activity by any source, point or nonpoint, of pollutants that is 
anticipated to result in an increased loading of BCCs to surface 
waters of the Great Lakes System and for which independent 
regulatory authority exists requiring compliance with water quality 
standards. Pursuant to this standard:
    A. Existing instream water uses, as defined pursuant to 40 CFR 
131, and the level of water quality necessary to protect existing 
uses shall be maintained and protected. Where designated uses of the 
waterbody are impaired, there shall be no lowering of the water 
quality with respect to the pollutant or pollutants which are 
causing the impairment;
    B. Where, for any parameter, the quality of the waters exceed 
levels necessary to support the propagation of fish, shellfish, and 
wildlife and recreation in and on the waters, that water shall be 
considered high quality for that parameter consistent with the 
definition of high quality water found at section II.A of this 
appendix and that quality [[Page 15413]] shall be maintained and 
protected unless the State or Tribe finds, after full satisfaction 
of intergovernmental coordination and public participation 
provisions of the State's or Tribe's continuing planning process, 
that allowing lower water quality is necessary to accommodate 
important economic or social development in the area in which the 
waters are located. In allowing such degradation, the State or Tribe 
shall assure water quality adequate to protect existing uses fully. 
Further, the State or Tribe shall assure that there shall be 
achieved the highest statutory and regulatory requirements for all 
new and existing point sources and all cost-effective and reasonable 
best management practices for nonpoint source control. The State or 
Tribe shall utilize the Antidegradation Implementation Procedures 
adopted pursuant to the requirements of this regulation in 
determining if any lowering of water quality will be allowed;
    C. Where high quality waters constitute an outstanding national 
resource, such as waters of national and State parks and wildlife 
refuges and waters of exceptional recreational or ecological 
significance, that water quality shall be maintained and protected; 
and
    D. In those cases where the potential lowering of water quality 
is associated with a thermal discharge, the decision to allow such 
degradation shall be consistent with section 316 of the Clean Water 
Act (CWA).

II. Antidegradation Implementation Procedures

    A. Definitions.
    Control Document. Any authorization issued by a State, Tribal or 
Federal agency to any source of pollutants to waters under its 
jurisdiction that specifies conditions under which the source is 
allowed to operate.
    High quality waters. High quality waters are water bodies in 
which, on a parameter by parameter basis, the quality of the waters 
exceeds levels necessary to support propagation of fish, shellfish, 
and wildlife and recreation in and on the water.
    Lake Superior Basin--Outstanding International Resource Waters. 
Those waters designated as such by a Tribe or State consistent with 
the September 1991 Bi-National Program to Restore and Protect the 
Lake Superior Basin. The purpose of such designations shall be to 
ensure that any new or increased discharges of Lake Superior 
bioaccumulative substances of immediate concern are subject to best 
technology in process and treatment requirements.
    Lake Superior Basin--Outstanding National Resource Waters. Those 
waters designated as such by a Tribe or State consistent with the 
September 1991 Bi-National Program to Restore and Protect the Lake 
Superior Basin. The purpose of such designations shall be to 
prohibit new or increased discharges of Lake Superior 
bioaccumulative substances of immediate concern from point sources 
in these areas.
    Lake Superior bioaccumulative substances of immediate concern. A 
list of substances identified in the September 1991 Bi-National 
Program to Restore and Protect the Lake Superior Basin. They 
include: 2, 3, 7, 8-TCDD; octachlorostyrene; hexachlorobenzene; 
chlordane; DDT, DDE, and other metabolites; toxaphene; PCBs; and 
mercury. Other chemicals may be added to the list following States' 
or Tribes' assessments of environmental effects and impacts and 
after public review and comment.
    Outstanding National Resource Waters. Those waters designated as 
such by a Tribe or State. The State or Tribal designation shall 
describe the quality of such waters to serve as the benchmark of the 
water quality that shall be maintained and protected. Waters that 
may be considered for designation as Outstanding National Resource 
Waters include, but are not limited to, water bodies that are 
recognized as:
    Important because of protection through official action, such as 
Federal or State law, Presidential or secretarial action, 
international treaty, or interstate compact;
    Having exceptional recreational significance;
    Having exceptional ecological significance;
    Having other special environmental, recreational, or ecological 
attributes; or waters whose designation as Outstanding National 
Resource Waters is reasonably necessary for the protection of other 
waters so designated.
    Significant Lowering of Water Quality. A significant lowering of 
water quality occurs when there is a new or increased loading of any 
BCC from any regulated existing or new facility, either point source 
or nonpoint source for which there is a control document or 
reviewable action, as a result of any activity including, but not 
limited to:
    (1) Construction of a new regulated facility or modification of 
an existing regulated facility such that a new or modified control 
document is required;
    (2) Modification of an existing regulated facility operating 
under a current control document such that the production capacity 
of the facility is increased;
    (3) Addition of a new source of untreated or pretreated effluent 
containing or expected to contain any BCC to an existing wastewater 
treatment works, whether public or private;
    (4) A request for an increased limit in an applicable control 
document;
    (5) Other deliberate activities that, based on the information 
available, could be reasonably expected to result in an increased 
loading of any BCC to any waters of the Great Lakes System.
    b. Notwithstanding the above, changes in loadings of any BCC 
within the existing capacity and processes, and that are covered by 
the existing applicable control document, are not subject to an 
antidegradation review. These changes include, but are not limited 
to:
    (1) Normal operational variability;
    (2) Changes in intake water pollutants;
    (3) Increasing the production hours of the facility, (e.g., 
adding a second shift); or
    (4) Increasing the rate of production.
    C. Also, excluded from an antidegradation review are new 
effluent limits based on improved monitoring data or new water 
quality criteria or values that are not a result of changes in 
pollutant loading.
    B. For all waters, the Director shall ensure that the level of 
water quality necessary to protect existing uses is maintained. In 
order to achieve this requirement, and consistent with 40 CFR 
131.10, water quality standards use designations must include all 
existing uses. Controls shall be established as necessary on point 
and nonpoint sources of pollutants to ensure that the criteria 
applicable to the designated use are achieved in the water and that 
any designated use of a downstream water is protected. Where water 
quality does not support the designated uses of a waterbody or 
ambient pollutant concentrations exceed water quality criteria 
applicable to that waterbody, the Director shall not allow a 
lowering of water quality for the pollutant or pollutants preventing 
the attainment of such uses or exceeding such criteria.
    C. For Outstanding National Resource Waters:
    1. The Director shall ensure, through the application of 
appropriate controls on pollutant sources, that water quality is 
maintained and protected.
    2. Exception. A short-term, temporary (i.e., weeks or months) 
lowering of water quality may be permitted by the Director.
    D. For high quality waters, the Director shall ensure that no 
action resulting in a lowering of water quality occurs unless an 
antidegradation demonstration has been completed pursuant to section 
III of this appendix and the information thus provided is determined 
by the Director pursuant to section IV of this appendix to 
adequately support the lowering of water quality.
    1. The Director shall establish conditions in the control 
document applicable to the regulated facility that prohibit the 
regulated facility from undertaking any deliberate action, such that 
there would be an increase in the rate of mass loading of any BCC, 
unless an antidegradation demonstration is provided to the Director 
and approved pursuant to section IV of this appendix prior to 
commencement of the action. Imposition of limits due to improved 
monitoring data or new water quality criteria or values, or changes 
in loadings of any BCC within the existing capacity and processes, 
and that are covered by the existing applicable control document, 
are not subject to an antidegradation review.
    2. For BCCs known or believed to be present in a discharge, from 
a point or nonpoint source, a monitoring requirement shall be 
included in the control document. The control document shall also 
include a provision requiring the source to notify the Director or 
any increased loadings. Upon notification, the Director shall 
require actions as necessary to reduce or eliminate the increased 
loading.
    3. Fact Sheets prepared pursuant to 40 CFR 124.8 and 124.56 
shall reflect any conditions developed under sections II.D.1 or 
II.D.2 of this appendix and included in a permit.
    E. Special Provisions for Lake Superior.The following conditions 
apply in addition to those specified in section II.B through II.C of 
this appendix for waters of Lake Superior so designated.
    1. A State or Tribe may designate certain specified areas of the 
Lake Superior Basin as Lake Superior Basin--Outstanding National 
Resource Waters for the purpose of prohibiting the new or increased 
discharge of [[Page 15414]] Lake Superior bioaccumulative substances 
of immediate concern from point sources in these areas.
    2. States and Tribes may designate all waters of the Lake 
Superior Basin as Outstanding International Resource Waters for the 
purpose of restricting the increased discharge of Lake Superior 
bioaccumulative substances of immediate concern from point sources 
consistent with the requirements of sections III.C and IV.B of this 
appendix.
    F. Exemptions. Except as the Director may determine on a case-
by-case basis that the application of these procedures is required 
to adequately protect water quality, or as the affected waterbody is 
an Outstanding National Resource Water as defined in section II.A of 
this appendix, the procedures in this part do not apply to:
    1. Short-term, temporary (i.e., weeks or months) lowering of 
water quality;
    2. Bypasses that are not prohibited at 40 CFR 122.41(m); and
    3. Response actions pursuant to the Comprehensive Environmental 
Response, Compensation and Liability Act (CERCLA), as amended, or 
similar Federal, State or Tribal authorities, undertaken to 
alleviate a release into the environment of hazardous substances, 
pollutants or contaminants which may pose an imminent and 
substantial danger to public health or welfare.

III. Antidegradation Demonstration

    Any entity seeking to lower water quality in a high quality 
water or create a new or increased discharge of Lake Superior 
bioaccumulative substances of immediate concern in a Lake Superior 
Outstanding International Resource Water must first, as required by 
sections II.D or II.E.2 of this appendix, submit an antidegradation 
demonstration for consideration by the Director. States and Tribes 
should tailor the level of detail and documentation in 
antidegradation reviews, to the specific circumstances encountered. 
The antidegradation demonstration shall include the following:
    A. Pollution Prevention Alternatives Analysis. Identify any 
cost-effective pollution prevention alternatives and techniques that 
are available to the entity, that would eliminate or significantly 
reduce the extent to which the increased loading results in a 
lowering of water quality.
    B. Alternative or Enhanced Treatment Analysis. Identify 
alternative or enhanced treatment techniques that are available to 
the entity that would eliminate the lowering of water quality and 
their costs relative to the cost of treatment necessary to achieve 
applicable effluent limitations.
    C. Lake Superior. If the States or Tribes designate the waters 
of Lake Superior as Outstanding International Resource Waters 
pursuant to section II.E.2 of this appendix, then any entity 
proposing a new or increased discharge of any Lake Superior 
bioaccumulative substance of immediate concern to the Lake Superior 
Basin shall identify the best technology in process and treatment to 
eliminate or reduce the extent of the lowering of water quality. In 
this case, the requirements in section III.B of this appendix do not 
apply.
    D. Important Social or Economic Development Analysis. Identify 
the social or economic development and the benefits to the area in 
which the waters are located that will be foregone if the lowering 
of water quality is not allowed.
    E. Special Provision for Remedial Actions. Entities proposing 
remedial actions pursuant to the CERCLA, as amended, corrective 
actions pursuant to the Resource Conservation and Recovery Act, as 
amended, or similar actions pursuant to other Federal or State 
environmental statutes may submit information to the Director that 
demonstrates that the action utilizes the most cost effective 
pollution prevention and treatment techniques available, and 
minimizes the necessary lowering of water quality, in lieu of the 
information required by sections III.B through III.D of this 
appendix.

IV. Antidegradation Decision

    A. Once the Director determines that the information provided by 
the entity proposing to increase loadings is administratively 
complete, the Director shall use that information to determine 
whether or not the lowering of water quality is necessary, and, if 
it is necessary, whether or not the lowering of water quality will 
support important social and economic development in the area. If 
the proposed lowering of water quality is either not necessary, or 
will not support important social and economic development, the 
Director shall deny the request to lower water quality. If the 
lowering of water quality is necessary, and will support important 
social and economic development, the Director may allow all or part 
of the proposed lowering to occur as necessary to accommodate the 
important social and economic development. In no event may the 
decision reached under this section allow water quality to be 
lowered below the minimum level required to fully support existing 
and designated uses. The decision of the Director shall be subject 
to the public participation requirements of 40 CFR 25.
    B. If States designate the waters of Lake Superior as 
Outstanding International Resource Waters pursuant to section II.E.2 
of this appendix, any entity requesting to lower water quality in 
the Lake Superior Basin as a result of the new or increased 
discharge of any Lake Superior bioaccumulative substance of 
immediate concern shall be required to install and utilize the best 
technology in process and treatment as identified by the Director.

Appendix F to Part 132--Great Lakes Water Quality Initiative 
Implementation Procedures

Procedure 1: Site-specific Modifications to Criteria and Values

    Great Lakes States and Tribes shall adopt provisions consistent 
with (as protective as) this procedure.
    A. Requirements for Site-specific Modifications to Criteria and 
Values. Criteria and values may be modified on a site-specific basis 
to reflect local environmental conditions as restricted by the 
following provisions. Any such modifications must be protective of 
designated uses and aquatic life, wildlife or human health and be 
submitted to EPA for approval. In addition, any site-specific 
modifications that result in less stringent criteria must be based 
on a sound scientific rationale and shall not be likely to 
jeopardize the continued existence of endangered or threatened 
species listed or proposed under section 4 of the Endangered Species 
Act (ESA) or result in the destruction or adverse modification of 
such species' critical habitat. More stringent modifications shall 
be developed to protect endangered or threatened species listed or 
proposed under section 4 of the ESA, where such modifications are 
necessary to ensure that water quality is not likely to jeopardize 
the continued existence of such species or result in the destruction 
or adverse modification of such species' critical habitat. More 
stringent modifications may also be developed to protect candidate 
(C1) species being considered by the U.S. Fish and Wildlife Service 
(FWS) for listing under section 4 of the ESA, where such 
modifications are necessary to protect such species.
    1. Aquatic Life.
    a. Aquatic life criteria or values may be modified on a site-
specific basis to provide an additional level of protection, 
pursuant to authority reserved to the States and Tribes under Clean 
Water Act (CWA) section 510.
    Guidance on developing site-specific criteria in these instances 
is provided in Chapter 3 of the U.S. EPA Water Quality Standards 
Handbook, Second Edition--Revised (1994).
    b. Less stringent site-specific modifications to chronic or 
acute aquatic life criteria or values may be developed when:
    i. The local water quality characteristics such as Ph, hardness, 
temperature, color, etc., alter the biological availability or 
toxicity of a pollutant; or
    ii. The sensitivity of the aquatic organisms species that 
``occur at the site'' differs from the species actually tested in 
developing the criteria. The phrase ``occur at the site'' includes 
the species, genera, families, orders, classes, and phyla that: are 
usually present at the site; are present at the site only seasonally 
due to migration; are present intermittently because they 
periodically return to or extend their ranges into the site; were 
present at the site in the past, are not currently present at the 
site due to degraded conditions, and are expected to return to the 
site when conditions improve; are present in nearby bodies of water, 
are not currently present at the site due to degraded conditions, 
and are expected to be present at the site when conditions improve. 
The taxa that ``occur at the site'' cannot be determined merely by 
sampling downstream and/or upstream of the site at one point in 
time. ``Occur at the site'' does not include taxa that were once 
present at the site but cannot exist at the site now due to 
permanent physical alteration of the habitat at the site resulting, 
for example, from dams, etc.
    c. Less stringent modifications also may be developed to acute 
and chronic aquatic life criteria or values to reflect local 
physical and hydrological conditions.
    Guidance on developing site-specific criteria is provided in 
Chapter 3 of the U.S. EPA Water Quality Standards Handbook, Second 
Edition--Revised (1994). [[Page 15415]] 
    d. Any modifications to protect threatened or endangered aquatic 
species required by procedure 1.A of this appendix may be 
accomplished using either of the two following procedures:
    i. If the Species Mean Acute Value (SMAV) for a listed or 
proposed species, or for a surrogate of such species, is lower than 
the calculated Final Acute Value (FAV), such lower SMAV may be used 
instead of the calculated FAV in developing site-specific modified 
criteria; or,
    ii. The site-specific criteria may be calculated using the 
recalculation procedure for site-specific modifications described in 
Chapter 3 of the U.S. EPA Water Quality Standards Handbook, Second 
Edition--Revised (1994).
    2. Wildlife.
    a. Wildlife water quality criteria may be modified on a site-
specific basis to provide an additional level of protection, 
pursuant to authority reserved to the States and Tribes under CWA 
section 510.
    b. Less stringent site-specific modifications to wildlife water 
quality criteria may be developed when a site-specific 
bioaccumulation factor (BAF) is derived which is lower than the 
system-wide BAF derived under appendix B of this part. The 
modification must consider both the mobility of prey organisms and 
wildlife populations in defining the site for which criteria are 
developed. In addition, there must be a showing that:
    i. Any increased uptake of the toxicant by prey species 
utilizing the site will not cause adverse effects in wildlife 
populations; and
    ii. Wildlife populations utilizing the site or downstream waters 
will continue to be fully protected.
    c. Any modification to protect endangered or threatened wildlife 
species required by procedure 1.A of this appendix must consider 
both the mobility of prey organisms and wildlife populations in 
defining the site for which criteria are developed, and may be 
accomplished by using the following recommended method.
    i. The methodology presented in appendix D to part 132 is used, 
substituting appropriate species-specific toxicological, 
epidemiological, or exposure information, including changes to the 
BAF;
    ii. An interspecies uncertainty factor of 1 should be used where 
epidemiological data are available for the species in question. If 
necessary, species-specific exposure parameters can be derived as 
presented in Appendix D of this part;
    iii. An intraspecies uncertainty factor (to account for 
protection of individuals within a wildlife population) should be 
applied in the denominator of the effect part of the wildlife 
equation in appendix D of this part in a manner consistent with the 
other uncertainty factors described in appendix D of this part; and
    iv. The resulting wildlife value for the species in question 
should be compared to the two class-specific wildlife values which 
were previously calculated, and the lowest of the three shall be 
selected as the site-specific modification.

    Note: Further discussion on the use of this methodology may be 
found in the Great Lakes Water Quality Initiative Technical Support 
Document for Wildlife Criteria.

    3. BAFs.
    a. BAFs may be modified on a site-specific basis to larger 
values, pursuant to the authority reserved to the States and Tribes 
under CWA section 510, where reliable data show that local 
bioaccumulation is greater than the system-wide value.
    b. BAFs may be modified on a site-specific basis to lower 
values, where scientifically defensible, if:
    i. The fraction of the total chemical that is freely dissolved 
in the ambient water is different than that used to derive the 
system-wide BAFs (i.e., the concentrations of particulate organic 
carbon and the dissolved organic carbon are different than those 
used to derive the system-wide BAFs);
    ii. Input parameters of the Gobas model, such as the structure 
of the aquatic food web and the disequilibrium constant, are 
different at the site than those used to derive the system-wide 
BAFs;
    iii. The percent lipid of aquatic organisms that are consumed 
and occur at the site is different than that used to derive the 
system-wide BAFs; or
    iv. Site-specific field-measured BAFs or biota-sediment 
accumulation factor (BSAFs) are determined.
    If site-specific BAFs are derived, they shall be derived using 
the methodology in appendix B of this part.
    c. Any more stringent modifications to protect threatened or 
endangered species required by procedure 1.A of this appendix shall 
be derived using procedures set forth in the methodology in appendix 
B of this part.
    4. Human Health.
    a. Human health criteria or values may be modified on a site-
specific basis to provide an additional level of protection, 
pursuant to authority reserved to the States and Tribes under CWA 
section 510. Human health criteria or values shall be modified on a 
site-specific basis to provide additional protection appropriate for 
highly exposed subpopulations.
    b. Less stringent site-specific modifications to human health 
criteria or values may be developed when:
    i. local fish consumption rates are lower than the rate used in 
deriving human health criteria or values under appendix C of this 
part; and/or
    ii. a site-specific BAF is derived which is lower than that used 
in deriving human health criteria or values under appendix C of this 
part.
    B. Notification Requirements. When a State proposes a site-
specific modification to a criterion or value as allowed in section 
4.A above, the State should notify the other Great Lakes States of 
such a proposal and, for less stringent criteria, supply appropriate 
justification.
    C. References.
    U.S. EPA. 1984. Water Quality Standards Handbook--Revised. 
Chapter 3 and Appendices. U.S. Environmental Protection Agency, 
Office of Water Resource Center (RC-4100), 401 M Street, SW., 
Washington, DC 20960.

Procedure 2: Variances from Water Quality Standards for Point Sources

    The Great Lakes States or Tribes may adopt water quality 
standards (WQS) variance procedures and may grant WQS variances for 
point sources pursuant to such procedures. Variance procedures shall 
be consistent with (as protective as) the provisions in this 
procedure.
    A. Applicability. A State or Tribe may grant a variance to a WQS 
which is the basis of a water quality-based effluent limitation 
included in a National Pollutant Discharge Elimination System 
(NPDES) permit. A WQS variance applies only to the permittee 
requesting the variance and only to the pollutant or pollutants 
specified in the variance. A variance does not affect, or require 
the State or Tribe to modify, the corresponding water quality 
standard for the waterbody as a whole.
    1. This provision shall not apply to new Great Lakes dischargers 
or recommencing dischargers.
    2. A variance to a water quality standard shall not be granted 
that would likely jeopardize the continued existence of any 
endangered or threatened species listed under Section 4 of the 
Endangered Species Act (ESA) or result in the destruction or adverse 
modification of such species' critical habitat.
    3. A WQS variance shall not be granted if standards will be 
attained by implementing effluent limits required under sections 
301(b) and 306 of the Clean Water Act (CWA) and by the permittee 
implementing cost-effective and reasonable best management practices 
for nonpoint source control.
    B. Maximum Timeframe for Variances. A WQS variance shall not 
exceed five years or the term of the NPDES permit, whichever is 
less. A State or Tribe shall review, and modify as necessary, WQS 
variances as part of each water quality standards review pursuant to 
section 303(c) of the CWA.
    C. Conditions to Grant a Variance. A variance may be granted if:
    1. The permittee demonstrates to the State or Tribe that 
attaining the WQS is not feasible because:
    a. Naturally occurring pollutant concentrations prevent the 
attainment of the WQS;
    b. Natural, ephemeral, intermittent or low flow conditions or 
water levels prevent the attainment of the WQS, unless these 
conditions may be compensated for by the discharge of sufficient 
volume of effluent to enable WQS to be met without violating State 
or Tribal water conservation requirements;
    c. Human-caused conditions or sources of pollution prevent the 
attainment of the WQS and cannot be remedied, or would cause more 
environmental damage to correct than to leave in place;
    d. Dams, diversions or other types of hydrologic modifications 
preclude the attainment of the WQS, and it is not feasible to 
restore the waterbody to its original condition or to operate such 
modification in a way that would result in the attainment of the 
WQS;
    e. Physical conditions related to the natural features of the 
waterbody, such as the lack of a proper substrate cover, flow, 
depth, pools, riffles, and the like, unrelated to chemical water 
quality, preclude attainment of WQS; or [[Page 15416]] 
    f. Controls more stringent than those required by sections 
301(b) and 306 of the CWA would result in substantial and widespread 
economic and social impact.
    2. In addition to the requirements of C.1, above, the permittee 
shall also:
    a. Show that the variance requested conforms to the requirements 
of the State's or Tribe's antidegradation procedures; and
    b. Characterize the extent of any increased risk to human health 
and the environment associated with granting the variance compared 
with compliance with WQS absent the variance, such that the State or 
Tribe is able to conclude that any such increased risk is consistent 
with the protection of the public health, safety and welfare.
    D. Submittal of Variance Application. The permittee shall submit 
an application for a variance to the regulatory authority issuing 
the permit. The application shall include:
    1. All relevant information demonstrating that attaining the WQS 
is not feasible based on one or more of the conditions in section 
C.1 of this procedure; and,
    2. All relevant information demonstrating compliance with the 
conditions in section C.2 of this procedure.
    E. Public Notice of Preliminary Decision. Upon receipt of a 
complete application for a variance, and upon making a preliminary 
decision regarding the variance, the State or Tribe shall public 
notice the request and preliminary decision for public comment 
pursuant to the regulatory authority's Administrative Procedures Act 
and shall notify the other Great Lakes States and Tribes of the 
preliminary decision. This public notice requirement may be 
satisfied by including the supporting information for the variance 
and the preliminary decision in the public notice of a draft NPDES 
permit.
    F. Final Decision on Variance Request. The State or Tribe shall 
issue a final decision on the variance request within 90 days of the 
expiration of the public comment period required in section E of 
this procedure. If all or part of the variance is approved by the 
State or Tribe, the decision shall include all permit conditions 
needed to implement those parts of the variance so approved. Such 
permit conditions shall, at a minimum, require:
    1. Compliance with an initial effluent limitation which, at the 
time the variance is granted, represents the level currently 
achievable by the permittee, and which is no less stringent than 
that achieved under the previous permit;
    2. That reasonable progress be made toward attaining the water 
quality standards for the waterbody as a whole through appropriate 
conditions;
    3. When the duration of a variance is shorter than the duration 
of a permit, compliance with an effluent limitation sufficient to 
meet the underlying water quality standard, upon the expiration of 
said variance; and
    4. A provision that allows the permitting authority to reopen 
and modify the permit based on any State or Tribal triennial water 
quality standards revisions to the variance.
    The State shall deny a variance request if the permittee fails 
to make the demonstrations required under section C of this 
procedure.
    G. Incorporating Variance into Permit. The State or Tribe shall 
establish and incorporate into the permittee's NPDES permit all 
conditions needed to implement the variance as determined in section 
F of this procedure.
    H. Renewal of Variance. A variance may be renewed, subject to 
the requirements of sections A through G of this procedure. As part 
of any renewal application, the permittee shall again demonstrate 
that attaining WQS is not feasible based on the requirements of 
section C of this procedure. The permittee's application shall also 
contain information concerning its compliance with the conditions 
incorporated into its permit as part of the original variance 
pursuant to sections F and G of this procedure. Renewal of a 
variance may be denied if the permittee did not comply with the 
conditions of the original variance.
    I. EPA Approval. All variances and supporting information shall 
be submitted by the State or Tribe to the appropriate EPA regional 
office and shall include:
    1. Relevant permittee applications pursuant to section D of this 
procedure;
    2. Public comments and records of any public hearings pursuant 
to section E of this procedure;
    3. The final decision pursuant to section F of this procedure; 
and,
    4. NPDES permits issued pursuant to section G of this procedure.
    5. Items required by sections I.1 through I.3. of this procedure 
shall be submitted by the State within 30 days of the date of the 
final variance decision. The item required by section I.4 of this 
procedure shall be submitted in accordance with the State or Tribe 
Memorandum of Agreement with the Regional Administrator pursuant to 
40 CFR 123.24.
    6. EPA shall review the State or Tribe submittal for compliance 
with the CWA pursuant to 40 CFR 123.44, and 40 CFR 131.21.
    J. State WQS Revisions. All variances shall be appended to the 
State or Tribe WQS rules.

Procedure 3: Total Maximum Daily Loads, Wasteload Allocations for Point 
Sources, Load Allocations for Nonpoint Sources, Wasteload Allocations 
in the Absence of a TMDL, and Preliminary Wasteload Allocations for 
Purposes of Determining the Need for Water Quality Based Effluent 
Limits

    The Great Lakes States and Tribes shall adopt provisions 
consistent with (as protective as) this procedure 3 for the purpose 
of developing Total Maximum Daily Loads (TMDLs), Wasteload 
Allocations (WLAs) in the Absence of TMDLs, and Preliminary 
Wasteload Allocations for Purposes of Determining the Need for Water 
Quality Based Effluent Limits (WQBELs), except as specifically 
provided.
    A. Where a State or Tribe develops an assessment and remediation 
plan that the State or Tribe certifies meets the requirements of 
sections B through F of this procedure and public participation 
requirements applicable to TMDLs, and that has been approved by EPA 
as meeting those requirements under 40 CFR 130.6, the assessment and 
remediation plan may be used in lieu of a TMDL for purposes of 
appendix F to part 132. Assessment and remediation plans under this 
procedure may include, but are not limited to, Lakewide Management 
Plans, Remedial Action Plans, and State Water Quality Management 
Plans. Also, any part of an assessment and remediation plan that 
also satisfies one or more requirements under Clean Water Act (CWA) 
section 303(d) or implementing regulations may be incorporated by 
reference into a TMDL as appropriate. Assessment and remediation 
plans under this section should be tailored to the level of detail 
and magnitude for the watershed and pollutant being assessed.
    B. General Conditions of Application. Except as provided in 
Sec. 132.4, the following are conditions applicable to establishing 
TMDLs for all pollutants and pollutant parameters in the Great Lakes 
System, with the exception of whole effluent toxicity, unless 
otherwise provided in procedure 6 of appendix F. Where specified, 
these conditions also apply to wasteload allocations (WLAs) 
calculated in the absence of TMDLs and to preliminary WLAs for 
purposes of determining the needs for WQBELs under procedure 5 of 
appendix F.
    1. TMDLs Required. TMDLs shall, at a minimum, be established in 
accordance with the listing and priority setting process established 
in section 303(d) of the CWA and at 40 CFR 130.7. Where water 
quality standards cannot be attained immediately, TMDLs must reflect 
reasonable assurances that water quality standards will be attained 
in a reasonable period of time. Some TMDLs may be based on attaining 
water quality standards over a period of time, with specific 
controls on individual sources being implemented in stages. 
Determining the reasonable period of time in which water quality 
standards will be met is a case-specific determination considering a 
number of factors including, but not limited to: receiving water 
characteristics; persistence, behavior and ubiquity of pollutants of 
concern; type of remediation activities necessary; available 
regulatory and non-regulatory controls; and individual State or 
Tribal requirements for attainment of water quality standards.
    2. Attainment of Water Quality Standards. A TMDL must ensure 
attainment of applicable water quality standards, including all 
numeric and narrative criteria, Tier I criteria, and Tier II values 
for each pollutant or pollutants for which a TMDL is established.
    3. TMDL Allocations.
    a. TMDLs shall include WLAs for point sources and load 
allocations (LAs) for nonpoint sources, including natural 
background, such that the sum of these allocations is not greater 
than the loading capacity of the water for the pollutant(s) 
addressed by the TMDL, minus the sum of a specified margin of safety 
(MOS) and any capacity reserved for future growth.
    b. Nonpoint source LAs shall be based on:
    i. Existing pollutant loadings if changes in loadings are not 
reasonably anticipated to occur;
    ii. Increases in pollutant loadings that are reasonably 
anticipated to occur; [[Page 15417]] 
    iii. Anticipated decreases in pollutant loadings if such 
decreased loadings are technically feasible and are reasonably 
anticipated to occur within a reasonable time period as a result of 
implementation of best management practices or other load reduction 
measures. In determining whether anticipated decreases in pollutant 
loadings are technically feasible and can reasonably be expected to 
occur within a reasonable period of time, technical and 
institutional factors shall be considered. These decisions are case-
specific and should reflect the particular TMDL under consideration.
    c. WLAs. The portion of the loading capacity not assigned to 
nonpoint sources including background, or to an MOS, or reserved for 
future growth is allocated to point sources. Upon reissuance, NPDES 
permits for these point sources must include effluent limitations 
consistent with WLAs in EPA-approved or EPA-established TMDLs.
    d. Monitoring. For LAs established on the basis of subsection 
b.iii above, monitoring data shall be collected and analyzed in 
order to validate the TMDL's assumptions, to varify anticipated load 
reductions, to evaluate the effectiveness of controls being used to 
implement the TMDL, and to revise the WLAs and LAs as necessary to 
ensure that water quality standards will be achieved within the 
time-period established in the TMDL.
    4. WLA Values. If separate EPA-approved or EPA-established TMDLs 
are prepared for different segments of the same watershed, and the 
separate TMDLs each include WLAs for the same pollutant for one or 
more of the same point sources, then WQBELs for that pollutant for 
the point source(s) shall be consistent with the most stringent of 
those WLAs in order to ensure attainment of all applicable water 
quality standards.
    5. Margin of Safety (MOS). Each TMDL shall include a MOS 
sufficient to account for technical uncertainties in establishing 
the TMDL and shall describe the manner in which the MOS is 
determined and incorporated into the TMDL. The MOS may be provided 
by leaving a portion of the loading capacity unallocated or by using 
conservative modeling assumptions to establish WLAs and LAs. If a 
portion of the loading capacity is left unallocated to provide a 
MOS, the amount left unallocated shall be described. If conservative 
modeling assumptions are relied on to provide a MOS, the specific 
assumptions providing the MOS shall be identified.
    6. More Stringent Requirements. States and Tribes may exercise 
authority reserved to them under section 510 of the CWA to develop 
more stringent TMDLs (including WLAs and LAs) than are required 
herein, provided that all LAs in such TMDLs reflect actual nonpoint 
source loads or those loads that can reasonably be expected to occur 
within a reasonable time-period as a result of implementing nonpoint 
source controls.
    7. Accumulation in Sediments. TMDLs shall reflect, where 
appropriate and where sufficient data are available, contributions 
to the water column from sediments inside and outside of any 
applicable mixing zones. TMDLs shall be sufficiently stringent so as 
to prevent accumulation of the pollutant of concern in sediments to 
levels injurious to designated or existing uses, human health, 
wildlife and aquatic life.
    8. Wet Weather Events. Notwithstanding the exception provided 
for the establishment of controls on wet weather point sources in 
Sec. 132.4(e)(1), TMDLs shall reflect, where appropriate and where 
sufficient data are available, discharges resulting from wet weather 
events. This procedure does not provide specific procedures for 
considering discharges resulting from wet weather events. However, 
some of the provisions of procedure 3 may be deemed appropriate for 
considering wet weather events on a case-by-case basis.
    9. Background Concentration of Pollutants. The representative 
background concentration of pollutants shall be established in 
accordance with this subsection to develop TMDLs, WLAs calculated in 
the absence of a TMDL, or preliminary WLAs for purposes of 
determining the need for WQBELs under procedure 5 of appendix F. 
Background loadings may be accounted for in a TMDL through an 
allocation to a single ``background'' category or through individual 
allocations to the various background sources.
    a. Definition of Background. ``Background'' represents all 
loadings that: (1) flow from upstream waters into the specified 
watershed, waterbody or waterbody segment for which a TMDL, WLA in 
the absence of a TMDL or preliminary WLA for the purpose of 
determining the need for a WQBEL is being developed; (2) enter the 
specified watershed, waterbody or waterbody segment through 
atmospheric deposition or sediment release or resuspension; or (3) 
occur within the watershed, waterbody or waterbody segment as a 
result of chemical reactions.
    b. Data considerations. When determining what available data are 
acceptable for use in calculating background, the State or Tribe 
should use best professional judgment, including consideration of 
the sampling location and the reliability of the data through 
comparison to reported analytical detection levels and 
quantification levels. When data in more than one of the data sets 
or categories described in section B.9.c.i through B.9.c.iii below 
exist, best professional judgment should be used to select the one 
data set that most accurately reflects or estimates background 
concentrations. Pollutant degradation and transport information may 
be considered when utilizing pollutant loading data.
    c. Calculation requirements. Except as provided below, the 
representative background concentration for a pollutant in the 
specified watershed, waterbody or waterbody segment shall be 
established on a case-by-case basis as the geometric mean of:
    i. Acceptable available water column data; or
    ii. Water column concentrations estimated through use of 
acceptable available caged or resident fish tissue data; or
    iii. Water column concentrations estimated through use of 
acceptable available or projected pollutant loading data.
    d. Detection considerations.
    i. Commonly accepted statistical techniques shall be used to 
evaluate data sets consisting of values both above and below the 
detection level.
    ii. When all of the acceptable available data in a data set or 
category, such as water column, caged or resident fish tissue or 
pollutant loading data, are below the level of detection for a 
pollutant, then all the data for that pollutant in that data set 
shall be assumed to be zero.
    10. Effluent Flow. If WLAs are expressed as concentrations of 
pollutants, the TMDL shall also indicate the point source effluent 
flows assumed in the analyses. Mass loading limitations established 
in NPDES permits must be consistent with both the WLA and assumed 
effluent flows used in establishing the TMDL.
    11. Reserved Allocations. TMDLs may include reserved allocations 
of loading capacity to accommodate future growth and additional 
sources. Where such reserved allocations are not included in a TMDL, 
any increased loadings of the pollutant for which the TMDL was 
developed that are due to a new or expanded discharge shall not be 
allowed unless the TMDL is revised in accordance with these 
proceudres to include an allocation for the new or expanded 
discharge.
    C. Mixing Zones for Bioaccumulative Chemicals of Concern (BCCs). 
The following requirements shall be applied in establishing TMDLs, 
WLAs in the absence of TMDLs, and preliminary WLAs for purposes of 
determining the need for WQBELs under procedure 5 of appendix F, for 
BCCs:
    1. Beginning on March 23, 1997, there shall be no mixing 
available for new discharges of BCCs to the Great Lakes System. WLAs 
established through TMDLs, WLAs in the absence of TMDLs, and 
preliminary WLAs for purposes of determining the need for WQBELs for 
new discharges of BCCs shall be set equal to the most stringent 
applicable water quality criteria or values for the BCCs in 
question.
    2. For purposes of section C of procedure 3 of appendix F, new 
discharges are defined as: (1) discharges from new Great Lakes 
dischargers; or (2) new or expanded discharges from an existing 
Great Lakes discharger. All other discharges of BCCs are defined as 
existing discharges.
    3. Up until March 23, 2007, mixing zones for BCCs may be allowed 
for existing discharges to the Great Lakes System pursuant to the 
procedures specified in sections D and E of this procedure.
    4. Except as provided in sections C.5 and C.6 of this procedure, 
permits issued on or after March 23, 1997 shall not authorize mixing 
zones for existing discharges of BCCs to the Great Lakes System 
after March 23, 2007. After March 23, 2007, WLAs established through 
TMDLs, WLAs established in the absence of TMDLs and preliminary WLAs 
for purposes of determining the need for WQBELs under procedure 5 of 
appendix F for existing dischrges of BCCs to the Great Lakes System 
shall be set equal to the most stringent applicable water quality 
criteria or values for the BCCs in question.
    5. Exception for Water Conservation. States and Tribes may grant 
mixing zones for any existing discharge of BCCs to the Great Lakes 
[[Page 15418]] System beyond the dates specified in sections C.3 and 
C.4 of this procedure, where it can be demonstrated, on a case-by-
case basis, that failure to grant a mixing zone would preclude water 
conservation measures that would lead to overall load reductions in 
BCCs, even though higher concentrations of BCCs occur in the 
effluent. Such mixing zones must also be consistent with sections D 
and E of this procedure.
    6. Exception for Technical and Economic Considerations. States 
and Tribes may grant mixing zones beyond the dates specified in 
sections C.3 and C.4 of this procedure for any existing discharges 
of a BCC to the Great Lakes System upon the request of a discharger 
subject to the limited circumstances specified in sections C.6.a 
through C.6.d below. Such mixing zones shall also be consistent with 
sections D and E of this procedure.
    a. The permitting authority must determine that:
    i. The discharger is in compliance with and will continue to 
implement all applicable technology-based treatment and pretreatment 
requirements of CWA sections 301, 302, 304, 306, 307, 401, and 402, 
and is in compliance with its existing NPDES water quality-based 
effluent limitations, including those based on a mixing zone; and
    ii. The discharger has reduced and will continue to reduce the 
loading of the BCC for which a mixing zone is requested to the 
maximum extent possible.
    b. In making the determination in section C.6.a above, the State 
or Tribal authority should consider:
    i. The availability and feasibility, including cost 
effectiveness, of additional controls or pollution prevention 
measures for reducing and ultimately eliminating BCCs for that 
discharger, including those used by similar dischargers;
    ii. Whether the discharger or affected communities will suffer 
unreasonable economic effects if the mixing zone is eliminated;
    iii. The extent to which the discharger will implement an 
ambient monitoring plan to ensure compliance with water quality 
criteria at the edge of any authorized mixing zone or to ensure 
consistency with any applicable TMDL or such other strategy 
consistent with section A of this procedure; and,
    iv. Other information the State or Tribe deems appropriate.
    c. Any exceptions to the mixing zone elimination provision for 
existing discharges of BCCs granted pursuant to this section shall:
    i. Not result in any less stringent limitations than those 
existing March 23, 1997;
    ii. Not likely jeopardize the continued existence of any 
endangered or threatened species listed under section 4 of the ESA 
or result in the destruction or adverse modification of such 
species' critical habitat;
    iii. Be limited to one permit term unless the permitting 
authority makes a new determination in accordance with this section 
for each successive permit application in which a mixing zone for 
the BCC(s) is sought;
    iv. Reflect all information relevant to the size of the mixing 
zone considered by the State or Tribe under subsection b above;
    v. Protect all designated and existing uses of the receiving 
water;
    vi. Meet all applicable aquatic life, wildlife and human health 
criteria and values at the edge of the mixing zone and, as 
appropriate, within the mixing zone or be consistent with any 
appropriate TMDL or such other strategy consistent with section A of 
this procedure;
    vii. Ensure the discharger has developed and conducted a 
pollutant minimization program for the BCC(s) if required to do so 
under regulations adopted consistent with procedure 8 of appendix F; 
and
    viii. Ensure that alternative means for reducing BCCs elsewhere 
in the watershed are evaluated.
    d. For each draft NPDES permit that would allow a mixing zone 
for one or more BCCs after March 23, 2007, the fact sheet or 
statement of basis for the draft permit, required to be made 
available through public notice under 40 CFR 124.6(e), shall:
    i. Specify the mixing provisions used in calculating the permit 
limits; and
    ii. Identify each BCC for which a mixing zone is proposed.
    D. Deriving TMDLs, WLAs, and LAs for Point and Nonpoint Sources: 
WLAs in the Absence of a TMDL; and Preliminary WLAs for Purposes of 
Determining the Need for WQBELs for OWGL. This section addresses 
conditions for deriving TMDLs for Open Waters of the Great Lakes 
(OWGL), inland lakes and other waters of the Great Lakes System with 
no appreciable flow relative to their volumes. State and Tribal 
procedures to derive TMDLs under this section must be consistent 
with (as protective as) the general conditions in section B of this 
procedure, CWA section 303(d), existing regulations (40 CFR 130.7), 
section C of this procedure, and sections D.1. through D.4 below. 
State and Tribal procedures to derive WLAs calculated in the absence 
of a TMDL and preliminary WLAs for purposes of determining the need 
for WQBELs under procedure 5 of appendix F must be consistent with 
sections B.9, C.1, C3 through C.6, and D. 1 through D.4 of this 
procedure.
    1. Individual point source WLAs and preliminary WLAs for 
purposes of determining the need for WQBELs under procedure 5 of 
appendix F shall assume no greater dilution than one part effluent 
to 10 parts receiving water for implementation of numeric and 
narrative chronic criteria and values (including, but not limited to 
human cancer criteria, human cancer values, human noncancer values, 
human noncancer criteria, wildlife criteria, and chronic aquatic 
life criteria and values) unless an alternative mixing zone is 
demonstrated as appropriate in a mixing zone demonstration conducted 
pursuant to section F of this procedure. In no case shall a mixing 
zone be granted that exceeds the area where discharge-induced mixing 
occurs.
    2. Appropriate mixing zone assumptions to be used in calculating 
load allocations for nonpoint sources shall be determined, 
consistent with applicable State or Tribal requirements, on a case-
by-case basis.
    3. WLAs and preliminary WLAs based on acute aquatic life 
criteria or values shall not exceed the Final Acute Value (FAV), 
unless a mixing zone demonstration is conducted and approved 
pursuant to section F of this procedure. If mixing zones from two or 
more proximate sources interact or overlap, the combined effect must 
be evaluated to ensure that applicable criteria and values will be 
met in the area where acute mixing zones overlap.
    4. In no case shall a mixing zone be granted that would likely 
jeopardize the continued existence of any endangered or threatened 
species listed under section 4 of the ESA or result in the 
destruction or adverse modification of such species' critical 
habitat.
    E. Deriving TMDLs, WLAs, and LAs for Point and Nonpoint Sources; 
WLAs in the Absence of a TMDL; and Preliminary WLAs for the Purposes 
of Determining the Need for WQBELs for Great Lakes Systems 
Tributaries and Connecting Channels. This section describes 
conditions for deriving TMDLs for tributaries and connecting 
channels of the Great Lakes System that exhibit appreciable flows 
relative to their volumes. State and Tribal procedures to derive 
TMDLs must be consistent with the general conditions listed in 
section B of this procedure, section C of this procedure, existing 
TMDL regulations (40 CFR 130.7) and specific conditions E.1 through 
E.5. State and Tribal procedures to derive WLAs calculated in the 
absence of a TMDL, and preliminary WLAs for purposes of determining 
reasonable potential under procedure 5 of this appendix for 
discharges to tributaries and connecting channels must be consistent 
with sections B.9, C.1, C.3 through C.6, and E.1 through E.5 of this 
procedure.
    1. Stream Design. These design flows must be used unless data 
exist to demonstrate that an alternative stream design flow is 
appropriate for stream-specific and pollutant-specific conditions. 
For purposes of calculating a TMDL, WLAs in the absence of a TMDL, 
or preliminary WLAs for the purposes of determining reasonable 
potential under procedure 5 of this appendix, using a steady-state 
model, the stream design flows shall be:
    a. The 7-day, 10-year stream design flow (7Q10), or the 4-day, 
3-year biologically-based stream design flow for chronic aquatic 
life criteria or values;
    b. The 1-day, 10-year stream design flow (1Q10), for acute 
aquatic life criteria or values;
    c. The harmonic mean flow for human health criteria or values;
    d. The 90-day, 10-year flow (90Q10) for wildlife criteria.
    e. TMDLs, WLAs in the absence of TMDLs, and preliminary WLAs for 
the purpose of determining the need for WQBELs calculated using 
dynamic modelling do not need to incorporate the stream design flows 
specified in sections E.1.a through E.1.d of this procedure.
    2. Loading Capacity. The loading capacity is the greatest amount 
of loading that a water can receive without violating water quality 
standards. The loading capacity is initially calculated at the 
farthest downstream location in the watershed drainage basin. The 
maximum allowable loading consistent with the attainment of each 
applicable numeric [[Page 15419]] criterion or value for a given 
pollutant is determined by multiplying the applicable criterion or 
value by the flow at the farthest downstream location in the 
tributary basin at the design flow condition described above. This 
loading is then compared to the loadings at sites within the basin 
to assure that applicable numeric criteria or values for a given 
pollutant are not exceeded at all applicable sites. The lowest load 
is then selected as the loading capacity.
    3. Polluant Degradation. TMDLs, WLAs in the absence of a TMDL 
and preliminary WLAs for purposes of determining the need for WQBELs 
under procedure 5 of appendix F shall be based on the assumption 
that a pollutant does not degrade. However, the regulatory authority 
may take into account degradation of the pollutant if each of the 
following conditions are met.
    a. Scientifically valid field studies or other relevant 
information demonstrate that degradation of the pollutant is 
expected to occur under the full range of environmental conditions 
expected to be encountered;
    b. Scientifically valid field studies or other relevant 
information address other factors that affect the level of 
pollutants in the water column including, but not limited to, 
resuspension of sediments, chemical speciation, and biological and 
chemical transformation.
    4. Acute Aquatic Life Criteria and Values. WLAs and LAs 
established in a TMDL, WLAs in the absence of a TMDL, and 
preliminary WLAs for the purpose of determining the need for WQBELs 
based on acute aquatic life criteria or values shall not exceed the 
FAV, unless a mixing zone demonstration is completed and approved 
pursuant to section F of this procedure. If mixing zones from two or 
more proximate sources interact or overlap, the combined effect must 
be evaluated to ensure that applicable criteria and values will be 
met in the area where any applicable acute mixing zones overlap. 
This acute WLA review shall include, but not be limited to, 
consideration of:
    a. The expected dilution under all effluent flow and 
concentration conditions at stream design flow;
    b. Maintenance of a zone of passage for aquatic organisms; and
    c. Protection of critical aquatic habitat.
    In no case shall a permitting authority grant a mixing zone that 
would likely jeopardize the continued existence of any endangered or 
threatened species listed under section 4 of the ESA or result in 
the destruction or adverse modification of such species' critical 
habitat.
    5. Chronic Mixing Zones. WLAs and LAs established in a TMDL, 
WLAs in the absence of a TMDL, and preliminary WLAs for the purposes 
of determining the need for WQBELs for protection of aquatic life, 
wildlife and human health from chronic effects shall be calculated 
using a dilution fraction no greater than 25 percent of the stream 
design flow unless a mixing zone demonstration pursuant to section F 
of this procedure is conducted and approved. A demonstration for a 
larger mixing zone may be provided, if approved and implemented in 
accordance with section F of this procedure. In no case shall a 
permitting authority grant a mixing zone that would likely 
jeopardize the continued existence of any endangered or threatened 
species listed under section 4 of the ESA or result in the 
destruction or adverse modification of such species' critical 
habitat.
    F. Mixing Zone Demonstration Requirements.
    1. For purposes of establishing a mixing zone other than as 
specified in sections D and E above, a mixing zone demonstration 
must:
    a. Describe the amount of dilution occurring at the boundaries 
of the proposed mixing zone and the size, shape, and location of the 
area of mixing, including the manner in which diffusion and 
dispersion occur;
    b. For sources discharging to the open waters of the Great Lakes 
(OWGLs), define the location at which discharge-induced mixing 
ceases;
    c. Document the substrate character and geomorphology within the 
mixing zone;
    d. Show that the mixing zone does not interfere with or block 
passage of fish or aquatic life;
    e. Show that the mixing zone will be allowed only to the extent 
that the level of the pollutant permitted in the waterbody would not 
likely jeopardize the continued existence of any endangered or 
threatened species listed under section 4 of the ESA or result in 
the destruction or adverse modification of such species' critical 
habitat;
    f. Show that the mixing zone does not extend to drinking water 
intakes;
    g. Show that the mixing zone would not otherwise interfere with 
the designated or existing uses of the receiving water or downstream 
waters;
    h. Document background water quality concentrations;
    i. Show that the mixing zone does not promote undesirable 
aquatic life or result in a dominance of nuisance species; and
    j. Provide that by allowing additional mixing/dilution:
    i. Substances will not settle to form objectionable deposits;
    ii. Floating debris, oil, scum, and other matter in 
concentrations that form nuisances will not be produced; and
    iii. Objectionable color, odor, taste or turbidity will not be 
produced.
    2. In addition, the mixing zone demonstration shall address the 
following factors:
    a. Whether or not adjacent mixing zones overlap;
    b. Whether organisms would be attracted to the area of mixing as 
a result of the effluent character; and
    c. Whether the habitat supports endemic or naturally occurring 
species.
    3. The mixing zone demonstration must be submitted to EPA for 
approval. Following approval of a mixing zone demonstration 
consistent with sections F.1 and F.2, adjustment to the dilution 
ratio specified in section D.1 of this procedure shall be limited to 
the dilution available in the area where discharger-induced mixing 
occurs.
    4. The mixing zone demonstration shall be based on the 
assumption that a pollutant does not degrade within the proposed 
mixing zone, unless:
    a. Scientifically valid field studies or other relevant 
information demonstrate that degradation of the pollutant is 
expected to occur under the full range of environmental conditions 
expected to be encountered; and
    b. Scientifically valid field studies or other relevant 
information address other factors that affect the level of 
pollutants in the water column including, but not limited to, 
resuspension of sediments, chemical speciation, and biological and 
chemical transformation.

Procedure 4: Additivity

    The Great Lakes States and Tribes shall adopt additivity 
provisions consistent with (as protective as) this procedure.
    A. The Great Lakes States and Tribes shall adopt provisions to 
protect human health from the potential adverse additive effects 
from both the noncarcinogenic and carcinogenic components of 
chemical mixtures in effluents. For the chlorinated dibenzo-p-
dioxins (CDDs) and chlorinated dibenzofurans (CDFs) listed in Table 
1, potential adverse additive effects in effluents shall be 
accounted for in accordance with section B of this procedure.
    B. Toxicity Equivalency Factors (TEFs)/Bioaccumulation 
Equivalency Factors (BEFs).
    1. The TEFs in Table 1 and BEFs in Table 2 shall be used when 
calculating a 2,3,7,8-TCDD toxicity equivalence concentration in 
effluent to be used when implementing both human health noncancer 
and cancer criteria. The chemical concentration of each CDDs and 
CDFs in effluent shall be converted to a 2,3,7,8-TCDD toxicity 
equivalence concentration in effluent by (a) multiplying the 
chemical concentration of each CDDs and CDFs in the effluent by the 
appropriate TEF in Table 1 below, (b) multiplying each product from 
step (a) by the BEF for each CDDs and CDFs in Table 2 below, and (c) 
adding all final products from step (b). The equation for 
calculating the 2,3,7,8-TCDD toxicity equivalence concentration in 
effluent is:
[GRAPHIC][TIFF OMITTED]TR23MR95.118


where:

(TEC)tcdd=2,3,7,8-TCDD toxicity equivalence concentration in 
effluent
(C)x=concentration of total chemical x in effluent
(TEF)x=TCDD toxicity equivalency factor for x
(BEF)x=TCDD bioaccumulation equivalency factor for x

    2. The 2,3,7,8-TCDD toxicity equivalence concentration in 
effluent shall be used when developing waste load allocations under 
procedure 3, preliminary waste load allocations for purposes of 
determining reasonable potential under procedure 5, and for purposes 
of establishing effluent quality limits under procedure 5.

        Table 1.--Toxicity Equivalency Factors for CDDs and CDFs        
------------------------------------------------------------------------
                          Congener                               TEF    
------------------------------------------------------------------------
2,3,7,8-TCDD...............................................        1.0  
1,2,3,7,8-PeCDD............................................        0.5  
[[Page 15420]]                                                          
                                                                        
1,2,3,4,7,8-HxCDD..........................................        0.1  
1,2,3,6,7,8-HxCDD..........................................        0.1  
1,2,3,7,8,9-HxCDD..........................................        0.1  
1,2,3,4,6,7,8-HpCDD........................................        0.01 
OCDD.......................................................        0.001
2,3,7,8-TCDF...............................................        0.1  
1,2,3,7,8-PeCDF............................................        0.05 
2,3,4,7,8-PeCDF............................................        0.5  
1,2,3,4,7,8-HxCDF..........................................        0.1  
1,2,3,6,7,8-HxCDF..........................................        0.1  
2,3,4,6,7,8-HxCDF..........................................        0.1  
1,2,3,7,8,9-HxCDF..........................................        0.1  
1,2,3,4,6,7,8-HpCDF........................................        0.01 
1,2,3,4,7,8,9-HpCDF........................................        0.01 
OCDF.......................................................        0.001
------------------------------------------------------------------------


     Table 2.--Bioaccumulation Equivalency Factors for CDDs and CDFs    
------------------------------------------------------------------------
                          Congener                               BEF    
------------------------------------------------------------------------
2,3,7,8-TCDD...............................................        1.0  
1,2,3,7,8-PeCDD............................................        0.9  
1,2,3,4,7,8-HxCDD..........................................        0.3  
1,2,3,6,7,8-HxCDD..........................................        0.1  
1,2,3,7,8,9-HxCDD..........................................        0.1  
1,2,3,4,6,7,8-HpCDD........................................        0.05 
OCDD.......................................................        0.01 
2,3,7,8-TCDF...............................................        0.8  
1,2,3,7,8-PeCDF............................................        0.2  
2,3,4,7,8-PeCDF............................................        1.6  
1,2,3,4,7,8-HxCDF..........................................        0.08 
1,2,3,6,7,8-HxCDF..........................................        0.2  
2,3,4,6,7,8-HxCDF..........................................        0.7  
1,2,3,7,8,9-HxCDF..........................................        0.6  
1,2,3,4,6,7,8-HpCDF........................................        0.01 
1,2,3,4,7,8,9-HpCDF........................................        0.4  
OCDF.......................................................        0.02 
------------------------------------------------------------------------

Procedure 5: Reasonable Potential To Exceed Water Quality Standards

    Great Lakes States and Tribes shall adopt provisions consistent 
with (as protective as) this procedure. If a permitting authority 
determines that a pollutant is or may be discharged into the Great 
Lakes System at a level which will cause, have the reasonable 
potential to cause, or contribute to an excursion above any Tier I 
criterion or Tier II value, the permitting authority shall 
incorporate a water quality-based effluent limitation (WQBEL) in an 
NPDES permit for the discharge of that pollutant. When facility-
specific effluent monitoring data are available, the permitting 
authority shall make this determination by developing preliminary 
effluent limitations (PEL) and comparing those effluent limitations 
to the projected effluent quality (PEQ) of the discharge in 
accordance with the following procedures. In all cases, the 
permitting authority shall use any valid, relevant, representative 
information that indicates a reasonable potential to exceed any Tier 
I criterion or Tier II value.
    A. Developing Preliminary Effluent Limitations on the Discharge 
of a Pollutant From a Point Source.
    1. The permitting authority shall develop preliminary wasteload 
allocations (WLAs) for the discharge of the pollutant from the point 
source to protect human health, wildlife, acute aquatic life, and 
chronic aquatic life, based upon any existing Tier I criteria. Where 
there is no Tier I criterion nor sufficient data to calculate a Tier 
I criterion, the permitting authority shall calculate a Tier II 
value for such pollutant for the protection of human health, and 
aquatic life and the preliminary WLAs shall be based upon such 
values. Where there is insufficient data to calculate a Tier II 
value, the permitting authority shall apply the procedure set forth 
in section C of this procedure to determine whether data must be 
generated to calculate a Tier II value.
    2. The following provisions in procedure 3 of appendix F shall 
be used as the basis for determining preliminary WLAs in accordance 
with section 1 of this procedure: procedure 3.B.9, Background 
Concentrations of Pollutants; procedure 3.C, Mixing Zones for 
Bioaccumulative Chemicals of Concern (BCCs), procedures 3.C.1, and 
3.C.3 through 3.C.6; procedure 3.D, Deriving TMDLs for Discharges to 
Lakes (when the receiving water is an open water of the Great Lakes 
(OWGL), an inland lake or other water of the Great Lakes System with 
no appreciable flow relative to its volume); procedure 3.E, Deriving 
TMDLs, WLAs and Preliminary WLAs, and load allocations (LAs) for 
Discharges to Great Lakes System Tributaries (when the receiving 
water is a tributary or connecting channel of the Great Lakes that 
exhibits appreciable flow relative to its volume); and procedure 
3.F, Mixing Zone Demonstration Requirements.
    3. The permitting authority shall develop PELs consistent with 
the preliminary WLAs developed pursuant to sections A.1 and A.2 of 
this procedure, and in accordance with existing State or Tribal 
procedures for converting WLAs into WQBELs. At a minimum:
    a. The PELs based upon criteria and values for the protection of 
human health and wildlife shall be expressed as monthly limitations;
    b. The PELs based upon criteria and values for the protection of 
aquatic life from chronic effects shall be expressed as either 
monthly limitations or weekly limitations; and
    c. The PELs based upon the criteria and values for the 
protection of aquatic life from acute effects shall be expressed as 
daily limitations.
    B. Determining Reasonable Potential Using Effluent Pollutant 
Concentration Data.
    If representative, facility-specific effluent monitoring data 
samples are available for a pollutant discharged from a point source 
to the waters of the Great Lakes System, the permitting authority 
shall apply the following procedures:
    1. The permitting authority shall specify the PEQ as the 95 
percent confidence level of the 95th percentile based on a log-
normal distribution of the effluent concentration; or the maximum 
observed effluent concentration, whichever is greater. In 
calculating the PEQ, the permitting authority shall identify the 
number of effluent samples and the coefficient of variation of the 
effluent data, obtain the appropriate multiplying factor from Table 
1 of procedure 6 of appendix F, and multiply the maximum effluent 
concentration by that factor. The coefficient of variation of the 
effluent data shall be calculated as the ratio of the standard 
deviation of the effluent data divided by the arithmetic average of 
the effluent data, except that where there are fewer than ten 
effluent concentration data points the coefficient of variation 
shall be specified as 0.6. If the PEQ exceeds any of the PELs 
developed in accordance with section A.3 of this procedure, the 
permitting authority shall establish a WQBEL in a NPDES permit for 
such pollutant.
    2. In lieu of following the procedures under section B.1 of this 
procedure, the permitting authority may apply procedures consistent 
with the following:
    a. The permitting authority shall specify the PEQ as the 95th 
percentile of the distribution of the projected population of daily 
values of the facility-specific effluent monitoring data projected 
using a scientifically defensible statistical method that accounts 
for and captures the long-term daily variability of the effluent 
quality, accounts for limitations associated with sparse data sets 
and, unless otherwise shown by the effluent data set, assumes a 
lognormal distribution of the facility-specific effluent data. If 
the PEQ exceeds the PEL based on the criteria and values for the 
protection of aquatic life from acute effects developed in 
accordance with section A.3 of this procedure, the permitting 
authority shall establish a WQBEL in an NPDES permit for such 
pollutant;
    b. The permitting authority shall calculate the PEQ as the 95th 
percentile of the distribution of the projected population of 
monthly averages of the facility-specific effluent monitoring data 
using a scientifically defensible statistical method that accounts 
for and captures the long-term variability of the monthly average 
effluent quality, accounts for limitations associated with sparse 
data sets and, unless otherwise shown by the effluent data set, 
assumes a lognormal distribution of the facility-specific effluent 
data. If the PEQ exceeds the PEL based on criteria and values for 
the protection of aquatic life from chronic effects, human health or 
wildlife developed in accordance with section A.3 of this procedure, 
the permitting authority shall establish a WQBEL in an NPDES permit 
for such pollutant; and
    c. The permitting authority shall calculate the PEQ as the 95th 
percentile of the distribution of the projected population of weekly 
averages of the facility-specific effluent monitoring data using a 
scientifically defensible statistical method that accounts for and 
captures the long-term variability of the weekly average effluent 
quality, accounts for limitations associated with sparse data sets 
and, unless otherwise shown by the effluent data set, assumes a 
lognormal distribution of the facility-specific effluent data. If 
the PEQ exceeds the PEL based on criteria and values to protect 
aquatic life from chronic effects developed in accordance with 
section A.3 of this procedure, the permitting 
[[Page 15421]] authority shall establish a WQBEL in an NPDES permit 
for such pollutant.
    C. Developing Necessary Data to Calculate Tier II Values Where 
Such Data Does Not Currently Exist.
    1. Except as provided in sections C.2, C.4, or D of this 
procedure, for each pollutant listed in Table 6 of part 132 that a 
permittee reports as known or believed to be present in its 
effluent, and for which pollutant data sufficient to calculate Tier 
II values for non-cancer human health, acute aquatic life and 
chronic aquatic life do not exist, the permitting authority shall 
take the following actions:
    a. The permitting authority shall use all available, relevant 
information, including Quantitative Structure Activity Relationship 
information and other relevant toxicity information, to estimate 
ambient screening values for such pollutant which will protect 
humans from health effects other than cancer, and aquatic life from 
acute and chronic effects.
    b. Using the procedures specified in sections A.1 and A.2 of 
this procedure, the permitting authority shall develop preliminary 
WLAs for the discharge of the pollutant from the point source to 
protect human health, acute aquatic life, and chronic aquatic life, 
based upon the estimated ambient screening values.
    c. The permitting authority shall develop PELs in accordance 
with section A.3 of this procedure, which are consistent with the 
preliminary WLAs developed in accordance with section C.1.b of this 
procedure.
    d. The permitting authority shall compare the PEQ developed 
according to the procedures set forth in section B of this procedure 
to the PELs developed in accordance with section C.1.c of this 
procedure. If the PEQ exceeds any of the PELs, the permitting 
authority shall generate or require the permittee to generate the 
data necessary to derive Tier II values for noncancer human health, 
acute aquatic life and chronic aquatic life.
    e. The data generated in accordance with section C.1.d of this 
procedure shall be used in calculating Tier II values as required 
under section A.1 of this procedure. The calculated Tier II value 
shall be used in calculating the preliminary WLA and PEL under 
section A of this procedure, for purposes of determining whether a 
WQBEL must be included in the permit. If the permitting authority 
finds that the PEQ exceeds the calculated PEL, a WQBEL for the 
pollutant or a permit limit on an indicator parameter consistent 
with 40 CFR 122.44(d)(1)(vi)(C) must be included in the permit.
    2. With the exception of bioaccumulative chemicals of concern 
(BCCs), a permitting authority is not required to apply the 
procedures set forth in section C.1 of this procedure or include 
WQBELs to protect aquatic life for any pollutant listed in Table 6 
of part 132 discharged by an existing point source into the Great 
Lakes System, if:
    a. There is insufficient data to calculate a Tier I criterion or 
Tier II value for aquatic life for such pollutant;
    b. The permittee has demonstrated through a biological 
assessment that there are no acute or chronic effects on aquatic 
life in the receiving water; and
    c. The permittee has demonstrated in accordance with procedure 6 
of this appendix that the whole effluent does not exhibit acute or 
chronic toxicity.
    3. Nothing in sections C.1 or C.2 of this procedure shall 
preclude or deny the right of a permitting authority to:
    a. Determine, in the absence of the data necessary to derive a 
Tier II value, that the discharge of the pollutant will cause, have 
the reasonable potential to cause, or contribute to an excursion 
above a narrative criterion for water quality; and
    b. Incorporate a WQBEL for the pollutant into an NPDES permit.
    4. If the permitting authority develops a WQBEL consistent with 
section C.3 of this procedure, and the permitting authority 
demonstrates that the WQBEL developed under section C.3 of this 
procedure is at least as stringent as a WQBEL that would have been 
based upon the Tier II value or values for that pollutant, the 
permitting authority shall not be obligated to generate or require 
the permittee to generate the data necessary to derive a Tier II 
value or values for that pollutant.
    D. Consideration of Intake Pollutants in Determining Reasonable 
Potential.
    1. General.
    a. Any procedures adopted by a State or Tribe for considering 
intake pollutants in water quality-based permitting shall be 
consistent with this section and section E.
    b. The determinations under this section and section E shall be 
made on a pollutant-by-pollutant, outfall-by-outfall, basis.
    c. This section and section E apply only in the absence of a 
TMDL applicable to the discharge prepared by the State or Tribe and 
approved by EPA, or prepared by EPA pursuant to 40 CFR 130.7(d), or 
in the absence of an assessment and remediation plan submitted and 
approved in accordance with procedure 3.A. of appendix F. This 
section and section E do not alter the permitting authority's 
obligation under 40 CFR 122.44(d)(vii)(B) to develop effluent 
limitations consistent with the assumptions and requirements of any 
available WLA for the discharge, which is part of a TMDL prepared by 
the State or Tribe and approved by EPA pursuant to 40 CFR 130.7, or 
prepared by EPA pursuant to 40 CFR 130.7(d).
    2. Definition of Same Body of Water.
    a. This definition applies to this section and section E of this 
procedure.
    b. An intake pollutant is considered to be from the same body of 
water as the discharge if the permitting authority finds that the 
intake pollutant would have reached the vicinity of the outfall 
point in the receiving water within a reasonable period had it not 
been removed by the permittee. This finding may be deemed 
established if:
    i. The background concentration of the pollutant in the 
receiving water (excluding any amount of the pollutant in the 
facility's discharge) is similar to that in the intake water;
    ii. There is a direct hydrological connection between the intake 
and discharge points; and
    iii. Water quality characteristics (e.g., temperature, Ph, 
hardness) are similar in the intake and receiving waters.
    c. The permitting authority may also consider other site-
specific factors relevant to the transport and fate of the pollutant 
to make the finding in a particular case that a pollutant would or 
would not have reached the vicinity of the outfall point in the 
receiving water within a reasonable period had it not been removed 
by the permittee.
    d. An intake pollutant from groundwater may be considered to be 
from the same body of water if the permitting authority determines 
that the pollutant would have reached the vicinity of the outfall 
point in the receiving water within a reasonable period had it not 
been removed by the permittee, except that such a pollutant is not 
from the same body of water if the groundwater contains the 
pollutant partially or entirely due to human activity, such as 
industrial, commercial, or municipal operations, disposed actions, 
or treatment processes.
    e. An intake pollutant is the amount of a pollutant that is 
present in waters of the United States (including groundwater as 
provided in section D.2.d of this procedure) at the time it is 
withdrawn from such waters by the discharger or other facility 
(e.g., public water supply) supplying the discharger with intake 
water.
    3. Reasonable Potential Determination.
    a. The permitting authority may use the procedure described in 
this section of procedure 5 in lieu of procedures 5.A through C 
provided the conditions specified below are met.
    b. The permitting authority may determine that there is no 
reasonable potential for the discharge of an identified intake 
pollutant or pollutant parameter to cause or contribute to an 
excursion above a narrative or numeric water quality criterion 
within an applicable water quality standard where a discharger 
demonstrates to the satisfaction of the permitting authority (based 
upon information provided in the permit application or other 
information deemed necessary by the permitting authority) that:
    i. The facility withdraws 100 percent of the intake water 
containing the pollutant from the same body of water into which the 
discharge is made;
    ii. The facility does not contribute any additional mass of the 
identified intake pollutant to its wastewater;
    iii. The facility does not alter the identified intake pollutant 
chemically or physically in a manner that would cause adverse water 
quality impacts to occur that would not occur if the pollutants were 
left in-stream;
    iv. The facility does not increase the identified intake 
pollutant concentration, as defined by the permitting authority, at 
the edge of the mixing zone, or at the point of discharge if a 
mixing zone is not allowed, as compared to the pollutant 
concentration in the intake water, unless the increased 
concentration does not cause or contribute to an excursion above an 
applicable water quality standard; and
    v. The timing and location of the discharge would not cause 
adverse water quality impacts to occur that would not occur if the 
identified intake pollutant were left in-stream.
    c. Upon a finding under section D.3.b of this procedure that a 
pollutant in the [[Page 15422]] discharge does not cause, have the 
reasonable potential to cause, or contribute to an excursion above 
an applicable water quality standard, the permitting authority is 
not required to include a WQBEL for the identified intake pollutant 
in the facility's permit, provided:
    i. The NPDES permit fact sheet or statement of basis includes a 
specific determination that there is no reasonable potential for the 
discharge of an identified intake pollutant to cause or contribute 
to an excursion above an applicable narrative or numeric water 
quality criterion and references appropriate supporting 
documentation included in the administrative record;
    ii. The permit requires all influent, effluent, and ambient 
monitoring necessary to demonstrate that the conditions in section 
D.3.b of this procedure are maintained during the permit term; and
    iii. The permit contains a reopener clause authorizing 
modification or revocation and reissuance of the permit if new 
information indicates changes in the conditions in section D.3.b of 
this procedure.
    d. Absent a finding under section D.3.b of this procedure that a 
pollutant in the discharge does not cause, have the reasonable 
potential to cause, or contribute to an excursion above an 
applicable water quality standard, the permitting authority shall 
use the procedures under sections 5.A through C of this procedure to 
determine whether a discharge causes, has the reasonable potential 
to cause, or contribute to an excursion above an applicable 
narrative or numeric water quality criterion.
    E. Consideration of Intake Pollutants in Establishing WQBELs.
    1. General. This section applies only when the concentration of 
the pollutant of concern upstream of the discharge (as determined 
using the provisions in procedure 3.B.9 of appendix F) exceeds the 
most stringent applicable water quality criterion for that 
pollutant.
    2. The requirements of sections D.1-D.2 of this procedure shall 
also apply to this section.
    3. Intake Pollutants from the Same Body of Water.
    a. In cases where a facility meets the conditions in sections 
D.3.b.i and D.3.b.iii through D.3.b.v of this procedure, the 
permitting authority may establish effluent limitations allowing the 
facility to discharge a mass and concentration of the pollutant that 
are no greater than the mass and concentration of the pollutant 
identified in the facility's intake water (``no net addition 
limitations''). The permit shall specify how compliance with mass 
and concentration limitations shall be assessed. No permit may 
authorize ``no net addition limitations'' which are effective after 
March 23, 2007. After that date, WQBELs shall be established in 
accordance with procedure 5.F.2 of appendix F.
    b. Where proper operation and maintenance of a facility's 
treatment system results in removal of a pollutant, the permitting 
authority may establish limitations that reflect the lower mass and/
or concentration of the pollutant achieved by such treatment, taking 
into account the feasibility of establishing such limits.
    c. For pollutants contained in intake water provided by a water 
system, the concentration of the intake pollutant shall be 
determined at the point where the raw water supply is removed from 
the same body of water, except that it shall be the point where the 
water enters the water supplier's distribution system where the 
water treatment system removes any of the identified pollutants from 
the raw water supply. Mass shall be determined by multiplying the 
concentration of the pollutant determined in accordance with this 
paragraph by the volume of the facility's intake flow received from 
the water system.
    4. Intake Pollutants from a Different Body of Water. Where the 
pollutant in a facility's discharge originates from a water of the 
United States that is not the same body of water as the receiving 
water (as determined in accordance with section D.2 of this 
procedure), WQBELs shall be established based upon the most 
stringent applicable water quality criterion for that pollutant.
    5. Multiple Sources of Intake Pollutants. Where a facility 
discharges intake pollutants that originate in part from the same 
body of water, and in part from a different body of water, the 
permitting authority may apply the procedures of sections E.3 and 
E.4 of this procedure to derive an effluent limitation reflecting 
the flow-weighted average of each source of the pollutant, provided 
that adequate monitoring to determine compliance can be established 
and is included in the permit.
    F. Other Applicable Conditions.
    1. In addition to the above procedures, effluent limitations 
shall be established to comply with all other applicable State, 
Tribal and Federal laws and regulations, including technology-based 
requirements and antidegradation policies.
    2. Once the permitting authority has determined in accordance 
with this procedure that a WQBEL must be included in an NPDES 
permit, the permitting authority shall:
    a. Rely upon the WLA established for the point source either as 
part of any TMDL prepared under procedure 3 of this appendix and 
approved by EPA pursuant to 40 CFR 130.7, or as part of an 
assessment and remediation plan developed and approved in accordance 
with procedure 3.A of this appendix, or, in the absence of such TMDL 
or plan, calculate WLAs for the protection of acute and chronic 
aquatic life, wildlife and human health consistent with the 
provisions referenced in section A.1 of this procedure for 
developing preliminary wasteload allocations, and
    b. Develop effluent limitations consistent with these WLAs in 
accordance with existing State or Tribal procedures for converting 
WLAs into WQBELs.
    3. When determining whether WQBELs are necessary, information 
from chemical-specific, whole effluent toxicity and biological 
assessments shall be considered independently.
    4. If the geometric mean of a pollutant in fish tissue samples 
collected from a waterbody exceeds the tissue basis of a Tier I 
criterion or Tier II value, after consideration of the variability 
of the pollutant's bioconcentration and bioaccumulation in fish, 
each facility that discharges detectable levels of such pollutant to 
that water has the reasonable potential to cause or contribute to an 
excursion above a Tier I criteria or a Tier II value and the 
permitting authority shall establish a WQBEL for such pollutant in 
the NPDES permit for such facility.

Procedure 6: Whole Effluent Toxicity Requirements

    The Great Lakes States and Tribes shall adopt provisions 
consistent with (as protective as) procedure 6 of appendix F of part 
132.
    The following definitions apply to this part:
    Acute toxic unit (TUa). 100/LC50 where the LC50 
is expressed as a percent effluent in the test medium of an acute 
whole effluent toxicity (WET) test that is statistically or 
graphically estimated to be lethal to 50 percent of the test 
organisms.
    Chronic toxic unit (TUc). 100/NOEC or 100/IC25, where 
the NOEC and IC25 are expressed as a percent effluent in the 
test medium.
    Inhibition concentration 25 (IC25). the toxicant 
concentration that would cause a 25 percent reduction in a non-
quantal biological measurement for the test population. For example, 
the IC25 is the concentration of toxicant that would cause a 25 
percent reduction in mean young per female or in growth for the test 
population.
    No observed effect concentration (NOEC). The highest 
concentration of toxicant to which organisms are exposed in a full 
life-cycle or partial life-cycle (short-term) test, that causes no 
observable adverse effects on the test organisms (i.e., the highest 
concentration of toxicant in which the values for the observed 
responses are not statistically significantly different from the 
controls).
    A. Whole Effluent Toxicity Requirements. The Great Lakes States 
and Tribes shall adopt whole effluent toxicity provisions consistent 
with the following:
    1. A numeric acute WET criterion of 0.3 acute toxic units 
(TUa) measured pursuant to test methods in 40 CFR part 136, or 
a numeric interpretation of a narrative criterion establishing that 
0.3 TUa measured pursuant to test methods in 40 CFR part 136 is 
necessary to protect aquatic life from acute effects of WET. At the 
discretion of the permitting authority, the foregoing requirement 
shall not apply in an acute mixing zone that is sized in accordance 
with EPA-approved State and Tribal methods.
    2. A numeric chronic WET criterion of one chronic toxicity unit 
(TUc) measured pursuant to test methods in 40 CFR part 136, or 
a numeric interpretation of a narrative criterion establishing that 
one TUc measured pursuant to test methods in 40 CFR part 136 is 
necessary to protect aquatic life from the chronic effects of WET. 
At the discretion of the permitting authority, the foregoing 
requirements shall not apply within a chronic mixing zone consistent 
with: (a) procedures 3.D.1 and 3.D.4, for discharges to the open of 
the Great Lakes (OWGL), inland [[Page 15423]] lakes and other waters 
of the Great Lakes System with no appreciable flow relative to their 
volume, or (b) procedure 3.E.5 for discharges to tributaries and 
connecting channels of the Great Lakes System.
    B. WET Test Methods. All WET tests performed to implement or 
ascertain compliance with this procedure shall be performed in 
accordance with methods established in 40 CFR part 136.
    C. Permit Conditions.
    1. Where a permitting authority determines pursuant to section D 
of this procedure that the WET of an effluent is or may be 
discharged at a level that will cause, have the reasonable potential 
to cause, or contribute to an excursion above any numeric WET 
criterion or narrative criterion within a State's or Tribe's water 
quality standards, the permitting authority:
    a. Shall (except as provided in section C.1.e of this procedure) 
establish a water quality-based effluent limitation (WQBEL) or 
WQBELs for WET consistent with section C.1.b of this procedure;
    b. Shall calculate WQBELs pursuant to section C.1.a. of this 
procedure to ensure attainment of the State's or Tribe's chronic WET 
criteria under receiving water flow conditions described in 
procedures 3.E.1.a (or where applicable, with procedure 3.E.1.e) for 
Great Lakes System tributaries and connecting channels, and with 
mixing zones no larger than allowed pursuant to section A.2. of this 
procedure. Shall calculate WQBELs to ensure attainment of the 
State's or Tribe's acute WET criteria under receiving water flow 
conditions described in procedure 3.E.1.b (or where applicable, with 
procedure 3.E.1.e) for Great Lakes System tributaries and connecting 
channels, with an allowance for mixing zones no greater than 
specified pursuant to section A.1 of this procedure.
    c. May specify in the NPDES permit the conditions under which a 
permittee would be required to perform a toxicity reduction 
evaluation.
    d. May allow with respect to any WQBEL established pursuant to 
section C.1.a of this procedure an appropriate schedule of 
compliance consistent with procedure 9 of appendix F; and
    e. May decide on a case-by-case basis that a WQBEL for WET is 
not necessary if the State's or Tribe's water quality standards do 
not contain a numeric criterion for WET, and the permitting 
authority demonstrates in accordance with 40 CFR 122.44(d)(1)(v) 
that chemical-specific effluent limits are sufficient to ensure 
compliance with applicable criteria.
    2. Where a permitting authority lacks sufficient information to 
determine pursuant to section D of this procedure whether the WET of 
an effluent is or may be discharged at levels that will cause, have 
the reasonable potential to cause, or contribute to an excursion 
above any numeric WET criterion or narrative criterion within a 
State's or Tribe's water quality standards, then the permitting 
authority should consider including in the NPDES permit appropriate 
conditions to require generation of additional data and to control 
toxicity if found, such as:
    a. WET testing requirements to generate the data needed to 
adequately characterize the toxicity of the effluent to aquatic 
life;
    b. Language requiring a permit reopener clause to establish WET 
limits if any toxicity testing data required pursuant to section 
C.2.a of this procedure indicate that the WET of an effluent is or 
may be discharged at levels that will cause, have the reasonable 
potential to cause, or contribute to an excursion above any numeric 
WET criterion or narrative criterion within a State's or Tribe's 
water quality standards.
    3. Where sufficient data are available for a permitting 
authority to determine pursuant to section D of this procedure that 
the WET of an effluent neither is nor may be discharged at a level 
that will cause, have the reasonable potential to cause, or 
contribute to an excursion above any numeric WET criterion or 
narrative criterion within a State's or Tribe's water quality 
standards, the permitting authority may include conditions and 
limitations described in section C.2 of this procedure at its 
discretion.
    D. Reasonable Potential Determinations. The permitting authority 
shall take into account the factors described in 40 CFR 
122.44(d)(1)(ii) and, where representative facility-specific WET 
effluent data are available, apply the following requirements in 
determining whether the WET of an effluent is or may be discharged 
at a level that will cause, have the reasonable potential to cause, 
or contribute to an excursion above any numeric WET criterion or 
narrative criterion within a State's or Tribe's water quality 
standards.
    1. The permitting authority shall characterize the toxicity of 
the discharge by:
    a. Either averaging or using the maximum of acute toxicity 
values collected within the same day for each species to represent 
one daily value. The maximum of all daily values for the most 
sensitive species tested is used for reasonable potential 
determinations;
    b. Either averaging or using the maximum of chronic toxicity 
values collected within the same calendar month for each species to 
represent one monthly value. The maximum of such values, for the 
most sensitive species tested, is used for reasonable potential 
determinations:
    c. Estimating the toxicity values for the missing endpoint using 
a default acute-chronic ratio (ACR) of 10, when data exist for 
either acute WET or chronic WET, but not for both endpoints.
    2. The WET of an effluent is or may be discharged at a level 
that will cause, have the reasonable potential to cause, or 
contribute to an excursion above any numeric acute WET criterion or 
numeric interpretation of a narrative criterion within a State's or 
Tribe's water quality standards, when effluent-specific information 
demonstrates that:

(TUa effluent) (B) (effluent flow/(Qad+effluent flow))>AC

Where TUa effluent is the maximum measured acute toxicity of 
100 percent effluent determined pursuant to section D.1.a. of this 
procedure, B is the multiplying factor taken from Table F6-1 of this 
procedure to convert the highest measured effluent toxicity value to 
the estimated 95th percentile toxicity value for the discharge, 
effluent flow is the same effluent flow used to calculate the 
preliminary wasteload allocations (WLAs) for individual pollutants 
to meet the acute criteria and values for those pollutants, AC is 
the numeric acute WET criterion or numeric interpretation of a 
narrative criterion established pursuant to section A.1 of this 
procedure and expressed in TUa, and Qad is the amount of the 
receiving water available for dilution calculated using: (i) the 
specified design flow(s) for tributaries and connecting channels in 
section C.1.b of this procedure, or where appropriate procedure 
3.E.1.e of appendix F, and using EPA-approved State and Tribal 
procedures for establishing acute mixing zones in tributaries and 
connecting channels, or (ii) the EPA-approved State and Tribal 
procedures for establishing acute mixing zones in OWGLs. Where there 
are less than 10 individual WET tests, the multiplying factor taken 
from Table F6-1 of this procedure shall be based on a coefficient of 
variation (CV) or 0.6. Where there are 10 or more individual WET 
tests, the multiplying factor taken from Table F6-1 shall be based 
on a CV calculated as the standard deviation of the acute toxicity 
values found in the WET tests divided by the arithmetic mean of 
those toxicity values.
    3. The WET of an effluent is or may be discharged at a level 
that will cause, have the reasonable potential to cause, or 
contribute to an excursion above any numeric chronic WET criterion 
or numeric interpretation of a narrative criterion within a State's 
or Tribe's water quality standards, when effluent-specific 
information demonstrates that:

(TUc effluent) (B) (effluent flow/Qad+effluent flow))>CC

Where TUc effluent is the maximum measured chronic toxicity 
value of 100 percent effluent determined in accordance with section 
D.1.b. of this procedure, B is the multiplying factor taken from 
Table F6-1 of this procedure, effluent flow is the same effluent 
flow used to calculate the preliminary WLAs for individual 
pollutants to meet the chronic criteria and values for those 
pollutants, CC is the numeric chronic WET criterion or numeric 
interpretation of a narrative criterion established pursuant to 
section A.2 of this procedure and expressed in TUc, and Qad is 
the amount of the receiving water available for dilution calculated 
using: (i) the design flow(s) for tributaries and connecting 
channels specified in procedure 3.E.1.a of appendix F, and where 
appropriate procedure 3.E.1.e of appendix F, and in accordance with 
the provisions of procedure 3.E.5 for chronic mixing zones, or (ii) 
procedures 3.D.1 and 3.D.4 for discharges to the OWGLs. Where there 
are less than 10 individual WET tests, the multiplying factor taken 
from Table F6-1 of this procedure shall be based on a CV of 0.6. 
Where there are 10 more individual WET tests, the multiplying factor 
taken from Table F6-1 of this procedure shall be based on a CV 
calculated as the standard deviation of the WET tests divided by the 
arithmetic mean of the WET tests.

                                                                        
[[Page 15424]]                                                          
                                              Table F6-1.--Reasonable Potential Multiplying Factors: 95% Confidence Level and 95% Probability Basis                                             
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                               Coefficient of variation                                                         
                  Number of Samples                  -------------------------------------------------------------------------------------------------------------------------------------------
                                                       0.1    0.2    0.3    0.4    0.5    0.6    0.7    0.8    0.9    1.0    1.1    1.2    1.3    1.4    1.5    1.6    1.7    1.8    1.9    2.0 
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1...................................................    1.4    1.9    2.6    3.6    4.7    6.2    8.0   10.1   12.6   15.5   18.7   22.3   26.4   30.8   35.6   40.7   46.2   52.1   58.4   64.9
2...................................................    1.3    1.6    2.0    2.5    3.1    3.8    4.6    5.4    6.4    7.4    8.5    9.7   10.9   12.2   13.6   15.0   16.4   17.9   19.5   21.1
3...................................................    1.2    1.5    1.8    2.1    2.5    3.0    3.5    4.0    4.6    5.2    5.8    6.5    7.2    7.9    8.6    9.3   10.0   10.8   11.5   12.3
4...................................................    1.2    1.4    1.7    1.9    2.2    2.6    2.9    3.3    3.7    4.2    4.6    5.0    5.5    6.0    6.4    6.9    7.4    7.8    8.3    8.8
5...................................................    1.2    1.4    1.6    1.8    2.1    2.3    2.6    2.9    3.2    3.6    3.9    4.2    4.5    4.9    5.2    5.6    5.9    6.2    6.6    6.9
6...................................................    1.1    1.3    1.5    1.7    1.9    2.1    2.4    2.6    2.9    3.1    3.4    3.7    3.9    4.2    4.5    4.7    5.0    5.2    5.5    5.7
7...................................................    1.1    1.3    1.4    1.6    1.8    2.0    2.2    2.4    2.6    2.8    3.1    3.3    3.5    3.7    3.9    4.1    4.3    4.5    4.7    4.9
8...................................................    1.1    1.3    1.4    1.6    1.7    1.9    2.1    2.3    2.4    2.6    2.8    3.0    3.2    3.3    3.5    3.7    3.9    4.0    4.2    4.3
9...................................................    1.1    1.2    1.4    1.5    1.7    1.8    2.0    2.1    2.3    2.4    2.6    2.8    2.9    3.1    3.2    3.4    3.5    3.6    3.8    3.9
10..................................................    1.1    1.2    1.3    1.5    1.6    1.7    1.9    2.0    2.2    2.3    2.4    2.6    2.7    2.8    3.0    3.1    3.2    3.3    3.4    3.6
11..................................................    1.1    1.2    1.3    1.4    1.6    1.7    1.8    1.9    2.1    2.2    2.3    2.4    2.5    2.7    2.8    2.9    3.0    3.1    3.2    3.3
12..................................................    1.1    1.2    1.3    1.4    1.5    1.6    1.7    1.9    2.0    2.1    2.2    2.3    2.4    2.5    2.6    2.7    2.8    2.9    3.0    3.0
13..................................................    1.1    1.2    1.3    1.4    1.5    1.6    1.7    1.8    1.9    2.0    2.1    2.2    2.3    2.4    2.5    2.5    2.6    2.7    2.8    2.9
14..................................................    1.1    1.2    1.3    1.4    1.4    1.5    1.6    1.7    1.8    1.9    2.0    2.1    2.2    2.3    2.3    2.4    2.5    2.6    2.6    2.7
15..................................................    1.1    1.2    1.2    1.3    1.4    1.5    1.6    1.7    1.8    1.8    1.9    2.0    2.1    2.2    2.2    2.3    2.4    2.4    2.5    2.5
16..................................................    1.1    1.1    1.2    1.3    1.4    1.5    1.6    1.6    1.7    1.8    1.9    1.9    2.0    2.1    2.1    2.2    2.3    2.3    2.4    2.4
17..................................................    1.1    1.1    1.2    1.3    1.4    1.4    1.5    1.6    1.7    1.7    1.8    1.9    1.9    2.0    2.0    2.1    2.2    2.2    2.3    2.3
18..................................................    1.1    1.1    1.2    1.3    1.3    1.4    1.5    1.6    1.6    1.7    1.7    1.8    1.9    1.9    2.0    2.0    2.1    2.1    2.2    2.2
19..................................................    1.1    1.1    1.2    1.3    1.3    1.4    1.5    1.5    1.6    1.6    1.7    1.8    1.8    1.9    1.9    2.0    2.0    2.0    2.1    2.1
20..................................................    1.1    1.1    1.2    1.2    1.3    1.4    1.4    1.5    1.5    1.6    1.6    1.7    1.7    1.8    1.8    1.9    1.9    2.0    2.0    2.0
30..................................................    1.0    1.1    1.1    1.1    1.2    1.2    1.2    1.3    1.3    1.3    1.3    1.4    1.4    1.4    1.4    1.5    1.5    1.5    1.5    1.5
40..................................................    1.0    1.0    1.1    1.1    1.1    1.1    1.1    1.1    1.2    1.2    1.2    1.2    1.2    1.2    1.2    1.2    1.2    1.2    1.3    1.3
50..................................................    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.1    1.1    1.1    1.1    1.1    1.1    1.1    1.1    1.1    1.1    1.1    1.1    1.1
60..................................................    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0    1.0
70..................................................    1.0    1.0    1.0    1.0    1.0    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.9
80..................................................    1.0    1.0    1.0    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.8    0.8    0.8    0.8    0.8    0.8
90..................................................    1.0    1.0    0.9    0.9    0.9    0.9    0.9    0.9    0.9    0.8    0.8    0.8    0.8    0.8    0.8    0.8    0.8    0.8    0.8    0.8
100.................................................    1.0    1.0    0.9    0.9    0.9    0.9    0.9    0.8    0.8    0.8    0.8    0.8    0.8    0.8    0.8    0.8    0.8    0.7    0.7    0.7
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Procedure 7: Loading Limits

    The Great Lakes States and Tribes shall adopt provisions 
consistent with (as protective as) this procedure.
    Whenever a water quality-based effluent limitation (WQBEL) is 
developed, the WQBEL shall be expressed as both a concentration 
value and a corresponding mass loading rate.
    A. Both mass and concentration limits shall be based on the same 
permit averaging periods such as daily, weekly, or monthly averages, 
or in other appropriate permit averaging periods.
    B. The mass loading rates shall be calculated using effluent 
flow rates that are consistent with those used in establishing the 
WQBELs expressed in concentration.

Procedure 8: Water Quality-based Effluent Limitations Below the 
Quantification Level

    The Great Lakes States and Tribes shall adopt provisions 
consistent with (as protective as) this procedure.
    When a water quality-based effluent limitation (WQBEL) for a 
pollutant is calculated to be less than the quantification level:
    A. Permit Limits. The permitting authority shall designate as 
the limit in the NPDES permit the WQBEL exactly as calculated.
    B. Analytical Method and Quantification Level.
    1. The permitting authority shall specify in the permit the most 
sensitive, applicable, analytical method, specified in or approved 
under 40 CFR part 136, or other appropriate method if one is not 
available under 40 CFR part 136, to be used to monitor for the 
presence and amount in an effluent of the pollutant for which the 
WQBEL is established; and shall specify in accordance with section 
B.2 of this procedure, the quantification level that can be achieved 
by use of the specified analytical method.
    2. The quantification level shall be the minimum level (ML) 
specified in or approved under 40 CFR part 136 for the method for 
that pollutant. If no such ML exists, or if the method is not 
specified or approved under 40 CFR part 136, the quantification 
level shall be the lowest quantifiable level practicable. The 
permitting authority may specify a higher quantification level if 
the permittee demonstrates that a higher quantification level is 
appropriate because of effluent-specific matrix interference.
    3. The permit shall state that, for the purpose of compliance 
assessment, the analytical method specified in the permit shall be 
used to monitor the amount of pollutant in an effluent down to the 
quantification level, provided that the analyst has complied with 
the specified quality assurance/quality control procedures in the 
relevant method.
    4. The permitting authority shall use applicable State and 
Tribal procedures to average and account for monitoring data. The 
permitting authority may specify in the permit the value to be used 
to interpret sample values below the quantification level.
    C. Special Conditions. The permit shall contain a reopener 
clause authorizing modification or revocation and reissuance of the 
permit if new information generated as a result of special 
conditions included in the permit indicates that presence of the 
pollutant in the discharge at levels above the WQBEL. Special 
conditions that may be included in the permit include, but are not 
limited to, fish tissue sampling, whole effluent toxicity (WET) 
tests, limits and/or monitoring requirements on internal waste 
streams, and monitoring for surrogate parameters. Data generated as 
a result of special conditions can be used to reopen the permit to 
establish more stringent effluent limits or conditions, if 
necessary.
    D. Pollutant Minimization Program. The permitting authority 
shall include a condition in the permit requiring the permittee to 
develop and conduct a pollutant minimization program for each 
pollutant with a WQBEL below the quantification level. The goal of 
the pollutant minimization program shall be to reduce all potential 
sources of the pollutant to maintain the effluent at or below the 
WQBEL. In addition, States and Tribes may consider cost-
effectiveness when establishing the requirements of a PMP. The 
pollutant minimization program shall include, but is not limited to, 
the following:
    1. An annual review and semi-annual monitoring of potential 
sources of the pollutant, which may include fish tissue monitoring 
and other bio-uptake sampling;
    2. Quarterly monitoring for the pollutant in the influent to the 
wastewater treatment system;
    3. Submittal of a control strategy designed to proceed toward 
the goal of maintaining all sources of the pollutant to the 
wastewater collection system below the WQBEL;
    4. When the sources of the pollutant are discovered, appropriate 
cost-effective control [[Page 15425]] measures shall be implemented, 
consistent with the control strategy; and
    5. An annual status report that shall be sent to the permitting 
authority including:
    a. All minimization program monitoring results for the previous 
year;
    b. A list of potential sources of the pollutant; and
    c. A summary of all action taken to reduce or eliminate the 
identified sources of the pollutant.
    6. Any information generated as a result of procedure 8.D can be 
used to support a request for subsequent permit modifications, 
including revisions to (e.g., more or less frequent monitoring), or 
removal of the requirements of procedure 8.D, consistent with 40 CFR 
122.44, 122.62 and 122.63.

Procedure 9: Compliance Schedules

    The Great Lakes States and Tribes shall adopt provisions 
consistent with (as protective as) procedure 9 of appendix F of part 
132.
    A. Limitations for New Great Lakes Dischargers. When a permit 
issued on or after March 23, 1997 to a new Great Lakes discharger 
(defined in Part 132.2) contains a water quality-based effluent 
limitation (WQBEL), the permittee shall comply with such a 
limitation upon the commencement of the discharge.
    B. Limitations for Existing Great Lakes Dischargers.
    1. Any existing permit that is reissued or modified on or after 
March 23, 1997 to contain a new or more restrictive WQBEL may allow 
a reasonable period of time, up to five years from the date of 
permit issuance or modification, for the permittee to comply with 
that limit, provided that the Tier I criterion or whole effluent 
toxicity (WET) criterion was adopted (or, in the case of a narrative 
criterion, Tier II value, or Tier I criterion derived pursuant to 
the methodology in appendix A of part 132, was newly derived) after 
July 1, 1977.
    2. When the compliance schedule established under paragraph 1 
goes beyond the term of the permit, an interim permit limit 
effective upon the expiration date shall be included in the permit 
and addressed in the permit's fact sheet or statement of basis. The 
administrative record for the permit shall reflect the final limit 
and its compliance date.
    3. If a permit establishes a schedule of compliance under 
paragraph 1 which exceeds one year from the date of permit issuance 
or modification, the schedule shall set forth interim requirements 
and dates for their achievement. The time between such interim dates 
may not exceed one year. If the time necessary for completion of any 
interim requirement is more than one year and is not readily 
divisible into stages for completion, the permit shall require, at a 
minimum, specified dates for annual submission of progress reports 
on the status of any interim requirements.
    C. Delayed Effectiveness of Tier II Limitations for Existing 
Great Lakes Discharges.
    1. Whenever a limit (calculated in accordance with Procedure 3) 
based upon a Tier II value is included in a reissued or modified 
permit for an existing Great Lakes discharger, the permit may 
provide a reasonable period of time, up to two years, in which to 
provide additional studies necessary to develop a Tier I criterion 
or to modify the Tier II value. In such cases, the permit shall 
require compliance with the Tier II limitation within a reasonable 
period of time, no later than five years after permit issuance or 
modification, and contain a reopener clause.
    2. The reopener clause shall authorize permit modifications if 
specified studies have been completed by the permittee or provided 
by a third-party during the time allowed to conduct the specified 
studies, and the permittee or a third-party demonstrates, through 
such studies, that a revised limit is appropriate. Such a revised 
limit shall be incorporated through a permit modification and a 
reasonable time period, up to five years, shall be allowed for 
compliance. If incorporated prior to the compliance date of the 
original Tier II limitation, any such revised limit shall not be 
considered less-stringent for purposes of the anti-backsliding 
provisions of section 402(o) of the Clean Water Act.
    3. If the specified studies have been completed and do not 
demonstrate that a revised limit is appropriate, the permitting 
authority may provide a reasonable additional period of time, not to 
exceed five years with which to achieve compliance with the original 
effluent limitation.
    4. Where a permit is modified to include new or more stringent 
limitations, on a date within five years of the permit expiration 
date, such compliance schedules may extend beyond the term of a 
permit consistent with section B.2 of this procedure.
    5. If future studies (other than those conducted under 
paragraphs 1, 2, or 3 above) result in a Tier II value being changed 
to a less stringent Tier II value or Tier I criterion, after the 
effective date of a Tier II-based limit, the existing Tier II-based 
limit may be revised to be less stringent if:
    (a) It complies with sections 402(o) (2) and (3) of the CWA; or,
    (b) In non-attainment waters, where the existing Tier II limit 
was based on procedure 3, the cumulative effect of revised effluent 
limitation based on procedure 3 of this appendix will assure 
compliance with water quality standards; or,
    (c) In attained waters, the revised effluent limitation complies 
with the State or Tribes' antidegradation policy and procedures.
[FR Doc. 95-6671 Filed 3-22-95; 8:45 am]
BILLING CODE 6560-50-P