United State* Office of Water Regulations
Environmental Protection and Standards
Agency Washington, D.C. 20460
Water
EPA Guidance for the
Implementation of
Section 303(d)/Total Maximum
Daily Loads
Draft 05/17/90
-------
Guidance for the Implementation of Section
303(d)/Total Maximum Daily Loads
Draft
May 1990
Assessment and Watershed Protection Division
U.S. Environmental Protection Agency
Washington, D.C. 20460
-------
This guidance will be reviewed and revised periodically to reflect changes in EPA's strategy for
the implementation of water quality-based controls, to inlcude new information, or to clarify/up-
date the text. Comments are invited and will be considered in these revisions. Comments or
inquiries should be directed to :
Monitoring Branch
Monitoring and Data Support Division (WH-553)
U.S. Environmental Protection Agency
401 M St. SW
Washington, D.C. 20460
Attention: Ed Drabkowski
-------
Letter of Transmittal
-------
Draft 051 15190
GUIDANCE FOR THE IMPLEMENTATION OF SECTION 303(d)/TOTAL MAXIMUM DAILY LOADS
EXECUTIVE SUMMARY i
CHAPTER 1 - INTRODUCTION 1
Purpose of Guidance 2
Summary of Section 303(d) Requirements 2
Regulatory Definitions 2
Requirements 3
Definitions for EPA Tracking 4
Statement of Policy 5
Roles of EPA and States 7
CHAPTER 2 - SECTION 303 (d) AND THE WATER QUALITY-BASED STANDARDS TO
PERMITS PROCESS 9
Standards-to-Permits Process 9
Identify and Prioritize Waters Needing Water Quality-based Controls 9
Review & Revise/Reaffirm Water Quality Standards 13
Develop Water Quality-based Controls 14
Implement Controls 15
Assess Result of Controls 15
Geographical Approach 16
CHAPTER 3 -- DEVELOPING TMDLs/WLAs/LAs 19
Technical Considerations 19
TMDL Process 19
Mathematical Models 20
Multiple Discharges 22
Allocation of Loads 23
Allocation Trading 24
Persistent and/or Highly Bioaccumulative Pollutants 24
Use of Two-number Criteria 25
Sediment Issues 26
Control Measures 26
Incorporating TMDLs/WLAs/LAs into permits 27
Nonpoint source controls - BMP Effectiveness Strategy 30
Phased Approach for TMDLs 3 1
CHAPTER 4 - IMPLEMENTATION 35
EPA/State Agreements 35
State Responsibilities 35
Development of Schedules and Timing 35
TMDL, WLA, and LA Development 36
Continuing Planning Process 38
Water Quality Management Planning 38
Public Notice and Participation 38
Reporting 39
Specific Requirements 39
-------
Draft 05/15190
EPA Responsibilities 40
TMDL Review and Approval 40
Tracking 42
Program Audits 42
Technical Assistance and Training 43
Guidance Documents and Reports 43
EPA Headquarters Responsibilities 43
EPA Regional Responsibilities 44
APPENDIX A SCREENING CATEGORIES 45
APPENDIX B RELATIONSHIP TO OTHER PROGRAMS 47
Monitoring Program 47
Section 304(1) - Impaired Waters 47
Section 319 ~ Nonpoint Source Program 47
Section 305(b) - Water Quality Assessment 48
EPA Criteria and Standards 48
Marine and Estuarine Waters 49
Groundwater 49
NPDES Permits and Individual Control Strategies 49
APPENDIX C RELATIONSHIP TO OTHER GUIDANCE 51
Monitoring Guidance 51
Wasteload Allocation Technical Guidance 51
Cooperative Monitoring 51
Technical Support Document for Water Quality-based Toxics Control 52
Permit Writers Guidance 52
Nonpoint Source Guidance 53
Antidegradation and Antibacksliding 53
APPENDIX D SUMMARY OF AVAILABLE MATHEMATICAL MODELS 54
APPENDIX E GENERAL OUTLINE EPA/STATE AGREEMENT FOR DEVELOPMENT
OF TMDLs, WLAs, and LAs 59
APPENDIX F EXAMPLE TRANSMITTAL LETTERS 60
LIST OF ACRONYMS 65
SELECTED OFFICES, DIVISIONS, BRANCHES, AND SECTIONS WITHIN EPA 66
-------
Draft 05115190
EXECUTIVE SUMMARY
This guidance document focuses on the Clean Water Act requirements under section 303(d) for the setting of total
maximum daily loads (TMDLs) for waters where effluent limitations are not stringent enough to meet State water
quality standards. The responsibility for overseeing the implementation of section 303(d) by the States is with the
EPA Regional offices and the EPA Headquarters' Office of Water Regulations and Standards.. This guidance is
intended for the use of State and EPA program managers to implement section 303(d) requirements. Technical
guidance is referenced and available for technical personnel responsible for developing TMDLs.
Total maximum daily loads include wasteload allocations (WLAs) for point source dischargers and load allocations
(LAs) for nonpoint source discharges. TMDLs represent the cumulative allowable loading to a waterbody.
EPA's surface water quality strategy is to ensure that current levels of controls on traditional point source
dischargers are in place and are maintained. Where these traditional controls are not sufficient and baseline
controls for non-traditional controls (i.e., best management practices for nonpoint sources, combined sewer
overflows, and stormwater discharges) are not yet in place, States should implement specific available practical
controls for the non-traditional sources causing the most serious impacts. If additional controls are still needed
to meet water quality standards, site-specific TMDLs would be developed.
Section 3Q3(d) Process
The implementation of section 303(d) can be described by a five-stepped process generally known as the "Water
Quality-based Standards to Permits" process. The steps in this process are: 1) identify and prioritize waters needing
water quality-based controls, 2) review and revise or reaffirm water quality standards, 3) develop water quality-
based controls (TMDLs, WLAs, LAs), 4) implement controls, and 5) assess results of controls.
EPA encourages the States to develop TMDLs in geographically targeted areas. Water quality management on a
broader geographic scale promotes efficient use of resources and effective management. Several States are
developing their programs following this concept.
Developing TMDLsAVLAs/LAs
After identifying needing water qulatiy-based controls, the TMDL process has four steps: 1) selecting the pollutant
to consider, 2) estimating the pollutant loading, 3) predicting pollutant concentrations, and 4) allocating pollutant
loads to meet water quality standards.
To aid in developing a TMDL, mathematical models have been developed for predicting characteristics of both
point and nonpoint source pollutants. Each model has a particular characteristic that makes it suitable for
application based on four categories: temporal/spatial characteristics; specific constituents; processes simulated;
and transport processes. Other considerations that must be decided include model selection based on its
application to the situation, appropriateness, and practical constraints.
Models provide the necessary information to enable the allocation of loadings among pollution sources. Some
innovations in allocating loads include trading loads between point and nonpoint sources which have demonstrated
cost savings.
Adequate site-specific information is needed to calibrate and verify mathematical procedures used during analysis.
Often, sufficient data is not available, particularly where load allocations from nonpoint sources are concerned.
To deal with these situations, EPA recommends that a phased approach to TMDL development be followed.
The phased approach establishes a process resulting in a final TMDL with a full margin of safety and includes the
following steps:
-------
Draft 05115/90
Phase I
Establish/maintain point source controls.
Establish practical NPS controls using best professional judgement (BPJ) and available data.
Begin collection of data on NPS loadings, etc.
Phase II
Develop provisional TMDL using NPS load/reduction estimates.
Phase III
Develop final TMDL.
Review/revise point source controls, if necessary.
Establish/revise NPS controls.
Program Implementation
EPA and the States have separate responsibilities for implementing section 303(d) requirements. Each State has
the responsibility for working with EPA to develop its schedules and timing for setting TMDLs based on its
identification and prioritization of waters needing water quality-based controls and reporting progress in complet-
ing the TMDLs.
EPA is responsible for seeing that the mandates regarding TMDL development are carried out, that program and
technical guidance is provided, and that adequate training and assistance is made available. EPA Regional offices
are responsible for reviewing and approving State submitted TMDLs and the lists of waters (and loads) still needing
TMDLs. EPA is also responsible for tracking the progress being made in TMDL development by the States and
in conducting general audits on their accomplishments.
-------
Draft 05115190
CHAPTER 1
INTRODUCTION
Under the Clean Water Act (CWA), the States and the Environmental
Protection Agency (EPA), in cooperation with State and local govern-
ments and other federal agencies, are responsible for restoring and
maintaining the chemical, physical, and biological integrity of the
nation's waters. Two key tools for water quality management are the
Total Maximum Daily Load (TMDL) process and monitoring. The
principal focus of this guidance is the TMDL process which is man-
dated under section 303(d) of the Clean Water Act (CWA). The EPA
Office of Water Regulation and Standards, Assessment and Water-
shed Protection Division (AWPD) is responsible for developing
guidance and technical support for TMDL development and monitor-
ing within the Monitoring Branch. AWPD is also responsible for
exposure assessments (e.g., National Bioaccumulation Study), infor-
mation services (e.g., databases), and special studies through the
Water Quality Analysis Branch. The Nonpoint Source Control Branch
is responsible for clean lakes program and nonpoint source (NFS)
evaluation and controls.
Total Maximum Daily Loads (TMDLs), Wasteload Allocations
(WLAs), and Load Allocations (LAs) are water quality planning and
management tools which are used to establish water quality-based
controls. The type of TMDL, WLA, or LA needed for a given water-
body will depend on the nature of the water quality problem(s), the
geographic target(s), whether the problem is localized or basin-wide,
and the characteristics of the receiving water (e.g., complexity of
natural circulation and mixing process, existence of multiple overlap-
ping discharges, influences from NPS).
This guidance is composed of four chapters. Chapter 1 describes the
requirements of section 303(d) of the Clean Water Act and the as-
sociated development of TMDLs, WLAs, and LAs. Identification and
prioritization of waters needing TMDLs and the Standards to Permits
process are described in Chapter 2. Technical considerations and
available control measures are summarized in Chapter 3. Chapter 4
describes State and EPA responsibilities in implementing the section
303(d) requirements.
-------
Draft 05115190
Purpose of Guidance
Summary of Section 303 (d)
Requirements
Regulatory Definitions
The purpose of this document is to provide the States and the EPA
Regional offices guidance on implementing the section 303(d) require-
ment of the Clean Water Act for developing water quality-based
controls. TMDLs, WLAs, and LAs are required for water quality
limited segments needing more stringent controls to meet water quality
standards. The guidance defines TMDLs, WLAs, and LAs in accord-
ance with EPA regulations and establishes definitions for purposes of
tracking TMDL development. Also, the guidance addresses EPA's
objectives of geographic targeting for nonpoint sources, time sequenc-
ing for TMDL development, phasing of TMDL development where
background NFS data may not be assessable, tracking the status of
actions on priority water quality-limited segments for both clean-up
purposes and preventive actions, and discusses related technical
aspects of the program.
The Water Quality Planning and Management regulation establishes
definitions for TMDLs, WLAs, and LAs. These definitions help pro-
vide for national consistency in developing water quality-based con-
trols.
Total Maximum Daily Loads The sum of the individual
WLAs for point sources and LAs for nonpoint sources and
natural background. If a receiving water has only one point
source discharger, the TMDL is the sum of the point source
WLA plus the LAs for any nonpoint sources of pollution and
natural background sources, tributaries, or adjacent seg-
ments. TMDLs can be expressed in terms of either mass per
time, toxicity, or other appropriate measure. If Best Manage-
ment Practices (BMPs) or other nonpoint source pollution
controls make more stringent load allocations practicable,
then WLAs can be made less stringent. Thus, the TMDL
process provides for nonpoint source control tradeoffs.
Wasteload Allocation ~ The portion of a receiving water's
loading capacity that is allocated to existing or future point
sources of pollution. WLAs constitute a type of water quality-
based effluent limitation.
Load Allocation The portion of a receiving water's loading
capacity that is attributed either to one of its existing or fu-
ture nonpoint sources of pollution or to natural background
sources. Load allocations are best estimates of the loading,
which may range from reasonably accurate estimates to gross
40 CFR 130.2
-------
Draft 05/15190
allotments. This will depend on the availability of data
and appropriate techniques for predicting the loading.
Wherever possible, natural and nonpoint source loads
should be distinguished.
A TMDL is a numerical quantification of the pollutant loading which
can be received by a waterbody and is based on the applicable State
water quality standard. The TMDL is comprised of WLAs for point
sources (e.g., industrial and municipal discharges), LAs for NPSs (e.g.,
agriculture, construction, silviculture), and a margin of safety. The
margin of safety is related to the uncertainty associated with estimating
loading capacities and the data or information available for a given
pollution problem. A greater margin of safety is associated with load
estimates which have larger uncertainties.
Section 303(d) of the Clean Water Act requires States to identify
waters that do not meet applicable water quality standards (including
thermal discharges) with technology-based controls alone. The States
are also required to establish a priority ranking for these waters, taking
into account the pollution severity and designated uses of waters.
TMDLs are to be established and approved for pollutants (and thermal
discharges) in order to achieve applicable water quality standards.
TMDLs must allow for seasonal variations and a margin of safety which
account for any lack of knowledge concerning site-specific discharge
conditions. In so doing, the States are to determine a TMDL for a
waterbody and to develop WLAs and LAs for related point source and
nonpoint source discharges to the same waterbody, respectively.
TMDLs, WLAs, and LAs must be established to meet antidegradation
and antibacksliding requirements.
Furthermore, States are required to submit to EPA "waters identified
and (pollutant) loads established" from time to time for review and
approval by EPA. After approval by EPA, States are to adopt these
pollutant loads into their continuing planning process (CPP). If dis-
approved by EPA, EPA will identify these waters and develop TMDLs
with related WLAs and LAs to be incorporated into the State's CPP.
Similar requirements for developing TMDLs are established for
waters that were not identified under section 303(d)(l)(A) of the
CWA, for the specific purpose of developing information. EPA has
interpreted this requirement to be completed as State resources allow.5
As a result, States may develop TMDLs for waters that are not im-
paired (e.g., threatened good quality waters).
Requirements
2 CWA section 303(d)(l)(C)
3 CWA section 303(d)(2)
4 CWA section 303(d)(3)
5 40 CFR 130.7(e)
-------
Draft 05115190
Definitions for EPA Tracking
If States do not submit a list of waters or required TMDLs to EPA,
EPA must interpret this as a constructive submission meaning that
there are no waters needing TMDLs in that State. It is incumbent on
EPA to approve or disapprove this submission. Should EPA disap-
prove a constructive submission, it is EPA's duty to identify waters
needing new or revised TMDLs. Similarly, if a State has defaulted to
act over a long period of time, it is EPA's duty to establish TMDLs as
necessary to carry out the goals and objectives of the Clean Water Act.6
In either case, it is EPA's strong preference to work with the States in
identifying waters and developing TMDLs.
For EPA to track the progress of TMDL, WLA, and LA development
at a national level, uniform definitions are necessary. In general,
WLAs represent the allowable loading allocated to the point sources,
LAs represent the allowable loadings to nonpoint sources, and
TMDLs represent the cumulative allowable loading to the waterbody
as described in the previous section. The following definitions,
developed by EPA, should be followed for the purposes of tracking
TMDL, WLA, and LA development.
One discharger will count as one WLA, even if the discharger
has multiple water quality-based parameters; revisions or ad-
ditions to the WLA will count as an additional WLA.
One LA will be counted for the estimate given to a nonpoint
pollution source which results in projected BMP controls;
multiple pollutants from the same nonpoint source do not
count as additional LAs unless different BMP controls are
projected; revisions or additions to the LA will count as an
additional LA.
One waterbody will count as one TMDL; the State-defined
water quality standard segment or the state-defined water
quality planning segment shall be used to delineate water-
bodies; if the water quality-based controls are designed to
protect more than one such waterbody (e.g., large basins),
more than one TMDL should be counted. For example, a
TMDL developed for a watershed which is composed of six
segments would count as six TMDLs.
All TMDLs, WLAs, and LAs should be tracked separately to provide
additional information to program administrators. In order to recog-
nize the different level of effort that is associated with the development
of some TMDLs, WLAs, and LAs, Regions should distinguish (count)
complex TMDLs. WLAs, and LAs. The intent is to identify simple
analyses that may be performed quickly with little effort, usually by
permit writers rather than water quality analysts. The Regions should
make the decision relative to complexity during the course of tracking.
Scott Decision (Scott vs. EPA, Nos. 81-2884 and 81-2885, decided on August 16,1984).
-------
Draft 05115190
The following examples are described to illustrate what constitute
complex situations. A "complex" condition exists when any of the
following situations occur:
Use of a water quality model is used which is more
sophisticated than the simple dilution calculation (e.g.,
continuous, dynamic models, steady state models that
model non-conservative water quality constituents, 2-d
and 3-d models, and models that consider sediment inter-
actions).
Use of simple dilution model is used that requires exten-
sive preparatory work (e.g., lengthy efforts to analyze
stream flow variables to develop critical flow, lengthy ef-
forts to analyze water quality data to characterize inputs
to the dilution model or to calibrate or verify the model).
A multiple discharge situation exists where either a
simple or sophisticated model and a WLA/TMDL dis-
tribution formula of some form is used (a distribution for-
mula, for example, may allocate loads on the basis of
flow, production, or relative water quality impacts).
Load allocations (LAs) situations where considerable ef-
fort is required to assess the transient and permanent na-
ture of adverse water quality impacts caused by various
nonpoint sources.
Any other situations where Regions feel justified that the
review or development of a particular WLA or TMDL
will require attention under EPA's tracking system (e.g.,
politically sensitive TMDLs, WLAs and LAs requiring
review by upper management levels).
TMDLs, WLAs, and LAs are to be counted at the time they are
approved by EPA. The WLA or LA does not have to be implemented
in a National Pollution Discharge Elimination System (NPDES) per-
mit or BMP control prior to this counting. Where a water quality
analysis has been performed and it is found that technology-based
requirements are adequate to maintain in-stream standards, the effort
should still be counted as a TMDL but not as a WLA or LA. Where
a water quality analysis has been performed and it is found that the
point (or nonpoint source as appropriate) has been relocated or
eliminated, a WLA (or a LA as appropriate) and a TMDL should still
be counted for tracking purposes, after review of the proposed water
quality-based controls.
Statement of Policy
EPA's objective is to first ensure that current levels of controls on
traditional sources are maintained. Next, States should focus on
geographic targeting of activities for waters that already exhibit sig-
nificant water quality problems or aquatic habitat loss, and waters that
may be pristine or are threatened and in need of protection. In many
of these areas with degraded waters, EPA finds that water quality is
impaired not by traditional sources (such as industrial and sewage
treatment plant discharges) but by non-traditional sources of pollution
-------
Draft 05115/90
(such as nonpoint sources, combined sewer overflows, and stormwater
discharges) for which baseline controls are not.yet in place. EPA's
immediate concern in these areas is to implement practical controls
for the non-traditional sources, while maintaining, or, as necessary,
improving, the current controls on traditional sources.
More intensive assessments of water quality and evaluation of the
sources should be conductedwhere water quality standards violations
or indications of declining water quality or habitat loss are observed
after controls on non-traditional sources are implemented. Allowable
pollution loading should be allocated among all sources on the basis of
water quality, and follow-up monitoring should be conducted peri-
odically to ensure that the water quality standards are met. (See
phased approach on page 31.) However, the lack of information about
non-traditional sources should not be used as a reason to delay im-
plementation of water quality-based controls when impairment is at-
tributed to point sources.
Where additional controls (in addition to practical controls) are still
needed to meet water quality standards, site specific TMDLs, WLA,
and LAs should be completed to meet water quality standards. TMDL
development is the primary method for developing water quality-based
controls hi waterbodies that are dominated by point source pollution
sources.
EPA recommends that States use the TMDL development process in
their water quality planning and management programs. The recom-
mendations summarized below are intended to guide the States in
managing their surface water quality programs, and are incorporated
throughout the remainder of this guidance.
Geographic Targets. States should develop TMDLs which in-
clude both point and nonpoint sources for State identified
waterbodies preferably on a geographically targeted basis.
Waterbodies could include segments, basins, watershed, and
ecoregions as defined by the States. (See page 16.)
Threatened Good Quality Waters. States are expected to in-
clude threatened good quality waters in their identification
and prioritization of waters still needing TMDLS. (See page
11.)
BMP Effectiveness Strategy. LAs for NPSs should be accom-
panied by a BMP effectiveness strategy for proposed NPS
reductions. Such plans would be referenced in reviewing
TMDLs for approval. (See page 30.)
Time Schedule. TMDLs should be developed on a schedule
negotiated with EPA Regional offices. Tune schedules for
the review of TMDLs should also be negotiated with EPA
Regional offices. (See page 35.)
Public Participation. States are encouraged to ensure ap-
propriate public participation in the TMDL review process.
(See page 38.)
Phased Approach for TMDL Development. When insuffi-
cient data exist to develop TMDLs (due to a lack of data to
quantify NPS loadings), EPA recommends that a phased ap-
-------
Draft 05/15/90
proach including an estimated provisional TMDL be es-
tablished as a practicable control measure toward
development of a final TMDL. (See page 31.)
Environmental Indicators. States should measure the ef-
fectiveness of control actions by monitoring changes in
ambient water quality or biological conditions. Measur-
ing environmental progress is a critical need.
States should perform regulatory monitoring, assess-
ments and program evaluations as needed to meet the re-
quirements of the Clean Water Act. States have the
primary responsibility for monitoring and water quality
analysis. In carrying out this responsibility, States are ex-
pected to implement a balanced monitoring program.
(See page 39.)
EPA Headquarters will provide overall policy, guidance, technical
assistance, training, and overview of program implementation by the
Regions and States. (See page 43.)
EPA Regions will provide overall policy, guidance, and overview of
program implementation by States. This includes providing oversight
of the States to ensure that adequate State resources from sections
106/205Q grants are directed to priority activities in monitoring, water
quality analysis, and data reporting. The Regions will also provide
technical assistance and training for States and ensure that needed
water quality-based controls are developed, and provide needed water
quality-based controls if the State fails to act in a timely manner.
Finally, the Regions will implement section 106(e) requirement for
adequate State monitoring programs and ensure that data are entered
into national data systems. (See page 44.)
Roles of EPA and the States
USEPA. 1985. Guidance for State Water Monitoring and Wasteload Allocation Program. EPA
440/4-85-031. OW/OWRS, Washington, D.C.
-------
Draft 05115190
-------
Draft 05!15/90
CHAPTER!
SECTION 303 (d) AND THE
WATER QUALITY-BASED
STANDARDS TO PERMITS
PROCESS
The process for identifying waters needing new or revised TMDLs,
establishing priorities, and developing needed pollution controls is
depicted by Figure 2-1, the Water Quality-Based Standards to Permits
process. The central role in this process is played by the State's water
quality standards. State water quality standards form the basic struc-
ture of the State's water quality management program and serve to
integrate the various water quality control requirements under section
303(d) into a manageable framework. The process is then made
effective by issuing water quality-based permits to regulate point
source dischargers and implementing BMPs to control nonpoint
polltuion sources, assuring that the water quality standards are met.
This process includes the following steps:
1. Identify and prioritize waters needing water quality-based
controls.
2. Review and revise/reaffirm water quality standards.
3. Develop water quality-based controls (TMDLs/WLA/LAs).
4. Implement controls.
5. Assess results of controls.
After technology-based controls on traditional sources are in place,
and practical controls are in place for non-traditional sources, a pro-
cedure is followed where States evaluate environmental data, review
water quality standards, and continue to perform assessments to iden-
tify waters needing water quality-based controls. As required by sec-
tion 303(d), these identified waters are listed based on the State's
Standards-to-Permits Process
Identify and Prioritize Waters
Needing Water Quality-Based
Controls
i£ UjC
^ £*
t
O
-------
Draft 05115190
Figure 2-1
General Elements of the Water Quality-Based
Standards-to-Permits Process
1. Identify and Prioritize
Waters Needing
Water Quality-Based
Controls
Set control strategies
Implement local
monitoring program
5. Assess Results of
Controls
Monitor point sources
for compliance
Monitor to determine
BMP effectiveness
2. Review and
Revise/Reaffirm
Water Quality
Standards
Perform ambient
monitoring to
document protection
of designated
uses
4. Implement Controls
Issue water quality-
based permits
3. Develop Water
Quality-Based
Controls
(TMDLs/WLAs/LAs)
Implement nonpolnt
source controls (BMPs)
Update WQMP
10
-------
Draft 05115 1901
established priorities for developing TMDLs. Once EPA has ap-
proved the list of waters (and loads) needing new or revised TMDLs
and the priority ranking for these waters, States prepare their annual
work plans to include the TMDL, WLA, and LA work to be done
during the following year as well as an estimate of work to be done over
the next five years. EPA recommends that States reserve some portion
of their resources to address hot-spots as they occur. The prioritized
list of waters developed by the State may be submitted as part of its
biennial section 305(b) report. As States implement their approved
work plans and submit TMDLs to EPA for approval, the TMDLs and
their component WLAs and LAs are incorporated into the State's
Water Quality Management Plan.
In accordance with the Clean Water Act, States are required to identify
and prepare a list of the waters (and loads) within their boundaries for
which existing pollution control requirements after technology-based
controls are or will not be stringent enough to meet the applicable
water quality standards. States should also include threatened good
quality waters in its lists of waters needing water quality-based controls.
Through the inclusion of waterbodies that are threatened, States may
incorporate a more proactive or preventative water quality manage-
ment policy which is strongly encouraged by EPA for the following
reasons:
A proactive policy is consistent with 40 CFR 130 which
requires that TMDLs be established for all pollutants
preventing or are expected to prevent water quality stand-
ards from being achieved.
It is often easier and less costly in the long term to
prevent impairments rather than cleaning up pollution
problems.
Meets EPA objectives which support coordination with
the States in collecting data on impacted or threatened
waters and implementing State plans for water quality
monitoring programs.
States should regularly update their lists of waters needing water
quality-based controls as assessments are made. For example, as new
data are collected and analyzed, it maybe determined that a previously
impaired waterbody is no longer impaired or vice versa. The list (or
the data base which stores the information to produce the list) is then
updated to reflect this change in status. To demonstrate that environ-
mental results are being achieved, States may provide summary infor-
mation on which waterbodies have been added or deleted from the list
and which waterbodies were assessed since the last reporting period.
40 CFR 130.6 (c)(l)
Identification
^
k
tv
Rj
fc'
11
-------
Draft 05115 190
1
I
I
Prioritization
$3
To develop the list of water quality limited waterbodies, States should
assemble and evaluate existing information on its waterbodies using
the general guidelines established under the several categories of
waters listed in Appendix A. In addition, data on waters available from
the Superfund and Reauthorization Act (SARA), Title III, Toxic
Chemicals Release Inventory (TRI) are applicable information for
listing purposes. Other data sources may include monitoring/assess-
ment reports from dischargers, environmental groups, universities, etc.
Also, States should consider waterbodies that have been previously
identified under CWA sections 319(a), 304(1), and 305(b) as needing
additional NFS controls, are water quality limited, are not meeting
designated uses, or are threatened. Information on these programs is
presented in Appendix B.
States must consider the following existing pollution control require-
ments in identifying waters needing new or revised TMDLs.
Technology-based effluent limitations required by:
- Sections 301(b), 306,307, and other sections of the CWA.
- State or local authority preserved by section 510 of the
CWA.
- Federal law, regulation, treaty, permit, lease, or other
authority.
Water quality-based effluent limitations required by:
- Section 301(b)(l)(C) of the CWA and incorporated into
an approved NPDES permit.
- State or local authority preserved by section 510 of the
Clean Water Act.
- Federal law, regulation, treaty, permit, lease, or other
authority.
Other pollution control requirements (e.g., Best Management
Practices) required by either Federal, State, or local authority.
Section 303(d) also requires each State to establish a priority ranking
for waters identified as needing new or revised TMDLs. It is recom-
mended that States establish a priority and time frame for developing
TMDLs over the next five years or a period negotiated with EPA
Regions in its State/EPA Agreement (see page 35.) These waters
should include all segments where TMDLs are needed to support
permits and BMPs during the coming year. Many of these waters do
not fully support designated uses; others waters may be threatened
good quality waters. Factors that States should consider in setting
priorities include:
The severity of the pollution.
The uses of the waters.
National policies and priorities such as EPA's annual Operat-
ing Guidance.
Court orders and decisions.
\il2
-------
Draft 05115190
Short-term water program needs; e.g., wasteload alloca-
tions needed for permits that are coming up for revisions
or for needed BMPs.
Data obtained in the development of the section
304(1)(1)(A) long list" and the several categories of
waters.
After waters have been identified and prioritized by States and ap-
proved by EPA, water quality standards for the selected waterbody are
reviewed by the State and revised or reaffirmed. The Water Quality
Standards Regulation sets forth the policies and procedures States
are to use in the development, review, revision, and approval of water
quality standards. The States have primary responsibility for setting
and enforcing water quality standards. At a nynimum, States must
hold public hearings for the adoption of water quality standards at least
once every three years. EPA is to ensure that State standards are
consistent with the CWA requirements and water quality standards
regulation. EPA has authority to approve or disapprove State stand-
ards and, when necessary, to promulgate federal water quality stand-
ards.
Standards adopted by States are composed of three parts: an an-
tidegradation statement, designated uses for individual waterbodies,
and a narrative or numerical criteria. According to antidegradation
requirements, if a designated use is currently being attained, the
waterbody may not be classified for a less stringent use. Likewise, if
the water quality is better than necessary to meet the designated use,
that level of water quality must be maintained unless the State meets
the conditions discussed in the Water Quality Standards regulations.
The criteria adopted in standards may apply State-wide, or may be
designated use specific or waterbody specific. Where narrative criteria
are adopted, the States should indicate as part of its water quality
standards submission how it intends to implement these criteria. In
general, State criteria may be developed for each parameter at two
levels of effect, typically acute and chronic.
UJ
Ul
Review and Revise/Reaffirm Water
Quality Standards
9 40 CFR 131
13
-------
Draft 05115190
Develop Water Quality-Based
Controls
EPA recommends adopting two-number acute and chronic criteria
whenever needed. National criteria may be used directly, or may be
adopted using site-specific criteria development protocols outlined in
the Water Quality Standards Handbook. ° Although the proposed
Water Quality Standards regulation requires that the State's process
for implementing its narrative criterion be described by the State, there
is no requirement that this concentration be adopted as a numerical
criterion in State water quality standards prior to use in developing
water quality-based controls. Additional technical information on use
attainability to support the development of water quality standards is
available from EPA.12
The third step of the standards to permits process is to use water quality
standards as the basis for developing TMDLs, WLA, and LAs. The
TMDL process gives States some flexibility in allocating pollutant
loads among various point and nonpoint sources impacting a water
body. To implement TMDLs, the States develop LAs for nonpoint
sources and WLAs for point sources, in accordance with 40 CFR 130.7.
The LA is that portion of a receiving water's assimilative capacity that
is allocated to existing or future sources of nonpoint pollution or to
natural background sources. The WLA is that portion of the receiving
water's loading capacity allocated to one of its existing or future point
sources of pollution. For nontoxic pollutants such as biochemical
oxygen demand (which may depress dissolved oxygen levels in the
receiving water) and nutrients (which may cause eutrophication),
mathematical models may be used to determine the pollution loading
consistent with the State's water quality standards and evaluate point
source or nonpoint source tradeoffs. In some simple situations, simple
dilution equations may be adequate for these analyses. Technical
guidance on the use of mathematical models for developing wasteload
allocations is available from EPA for a number of pollutants and types
of receiving waters (see Appendix C).
For toxic pollutants such as heavy metals, water quality analyses can be
done using one or both of two techniques: the pollutant-specific
approach and the biomonitoring approach.
10 USEPA. December, 1983. Water Quality Standards Handbook. OW/OWRS/Washington, D.C. '
11 40 CFR 131
12 USEPA. November, 1983. Technical Support Manual: Waterbody Surveys and Assessments for
Conducting Use Attainability Analyses. OW/OWRS, Washington, D.C
USEPA. . Technical Support Manual: Waterbody Surveys and Assessment for Conducting Use
Attainability Analyses, Volume II Estuarine Systems. OW/OWRS, Washington, D.C.
USEPA. November, 1984. Technical Support Manual: Waterbody Surveys and Assessments for
Conducting Use Attainability Analyses, Volume II Estuarine Systems. OW/OWRS, Washington, D.C.
14
-------
Draft 05/15190
The pollutant-specific approach is best suited for situa-
tions (effluents) with a few well-characterized pollutants
or when human health is a concern.
The biomonitoring approach should be used when the ef-
fluent is complex or when interactions of effluents in the
receiving water are of concern.
In many cases, both approaches will be needed. As discussed in
Appendix C EPA has prepared technical guidance on the development
of toxics controls using the pollutant-specific and the biomonitoring
approaches.
States should implement water quality-based controls in order to meet
loads established for individual point and nonpoint sources. It is the
responsibility of the State to:
Delegated States issue water quality-based permits.
Implement NFS controls (e.g., BMPs).
Update its water quality management plan (WQMP).
Monitoring may be required of dischargers (with appropriate quality
control by the regulatory authority) if existing information is inade-
quate to determine whether water quality-based controls are needed.
As with permits, construction decisions regarding publicly owned
treatment works (POTWs) or advanced treatments (ATs) must also
be based on the most stringent of technology-based or water quality-
based limitations. These decisions should be coordinated so that the
decision taken on the treatment facility is consistent with the limitations
in the permit. Implementation of BMPs should be coordinated with
other agencies to ensure that desired environmental results are
achieved. Since many implemented BMPs are not regulated, States
should establish a BMP effectiveness strategy which is used as a guide
for how States expect to meet LAs. This strategy should be designed
such that States can track BMP implementation and overall effective-
ness to ensure that progress is made towards meeting LAs. This
strategy should also describe the coordination which may be necessary
with other State agencies, landowners, operators, and managers. (See
page 30 for a discussion on BMP effectiveness strategy.)
Once water quality-based controls are in place, States should assess
environmental results. To facilitate State assessment, dischargers are
required to provide reports on compliance with NPDES permit limits.
They may also be required to assess the impact of their discharge on
the receiving water to ensure that the expected water quality is ac-
complished and water quality standards are met. Effluent and ambient
data collection requirements may be written into dischargers' permits
to assess the effectiveness of controls and to ensure that the designated
use of the water is maintained. If a State has not been approved to
implement the NPDES program, permitting and compliance reviews
of all permittees in that State are the responsibility of the EPA. In a
State with approved NPDES authority, EPA retains oversight respon-
Implement Controls
Assess Results of Controls
15
-------
Draft 05115190
Geographical Approach
sibility for the State compliance program and authority to conduct
compliance and enforcement in that State as necessary. Adequate
monitoring should be provided to ensure that BMPs are meeting their
designed goals. States are encouraged to use innovative monitoring
programs (e.g., cooperative monitoring ) to provide for adequate
nonpoint source monitoring.
Many water pollution concerns are area-wide phenomena that are
caused by multiple dischargers, multiple pollutants (with potential
synergistic and additive effects), or diffuse sources. As a result, tradi-
tional water quality-based procedures (those based on one discharger
or point source) may not be appropriate to address these types of
impairments. In order to efficiently manage the water quality needs of
the nation's surface waters, EPA recommends that States develop
TMDLs on a geographical basis such as the watershed. Several States
have already begun to base water quality management programs on
geographical approaches in order to provide more efficient use of
limited water quality program resources and to provide an effective
process for assessing both point and nonpoint sources.
Although States may define a waterbody to correspond with their
current programs, it is expected that States will consider the extent of
the pollution problem and sources when defining the geographic
region for developing TMDLs and associated WLAs and LAs. In
general, geographical approaches support sound environmental
management since many pollution concerns are not isolated to specific
locations. Similarly, monitoring and modeling efforts should cor-
respond to the same geographic regions.
Dissolved oxygen, for example, may be limited downstream from sour-
ces of BODs. In this case, it may be prudent for States to consider the
entire river reach, rather than limiting a study (monitoring and model-
ing) to a narrowly defined area such as a single river segment. Similar-
ly, pollutants which are adsorbed to sediment and are transported
downstream to reservoirs (or other settling pools) would be more
appropriately addressed by watershed level TMDLs. On the other
hand, pollutants which exhibit their maximum toxicity near outfalls and
do not pose harm to waters downstream may be addressed with a
relatively narrow geographic region. In the latter case, a near-Geld
mixing model may be adequate.
In cases where TMDLs are developed on watershed levels, States
should consider modifying their permitting cycle so that all permits on
a given watershed expire at the same time. Since TMDLs should
13
USEPA. 1984. Planning and Managing Cooperative Monitoring Projects. OW/OWRS, EPA 440/4-84-018,
Washington, D.C.
16
-------
Draft 05115190
consider all pollutant (including all permitted) sources, more efficient
use of resources may be accomplished by developing permits on a
similar geographic level as for the TMDLs.
17
-------
Draft 05115/90
18
-------
Draft 05/15190
CHAPTERS
DEVELOPING TMDLs/WLAs/LAs
After waters meeting new or revised TMDLs have been identified and
ranked by priority, EPA will review this information to ensure that all
significant water quality problems are included and to account for new
information on effluent concentrations associated with best available
technology (BAT), new water quality criteria, etc., prior to TMDL
development. To gain an understanding of the technical requirements
needed to develop TMDLs, this chapter describes selected technical
considerations associated with TMDL development as well as other
control measures that may be implemented to achieve load reduction
strategies.
The TMDL process includes four steps: 1) selection of the pollutant
or toxic characteristics to consider, 2) the estimation of pollutant
loading to waterbodies from all sources, 3) the prediction of resultant
pollutant concentrations and determination of allowable loads, and 4)
the allocation of the allowable loads among the different pollutant
sources in such a manner that water quality standards are achieved.
The analyst developing a TMDL must first identify the pollutants of
concern and their sources. This may entail additional monitoring, data
collection, and analysis. Then, the overall approach for allocating the
loads must be selected. For conventional pollutants, a pollutant-
specific approach is normally used. For toxic pollutants, a pollutant-
specific approach may be used if the effluent characteristics are known,
only a few specific toxicants are of interest, and multiple discharges do
not result in complex mixtures of toxicants. If the effluent toxics
component is not well characterized, or if several toxic constituents
with complex interactions (i.e., additive, synergistic, or antagonistic
effects) are involved, then the whole effluent approach should be used.
If any of the effluents contain chemicals that are persistent or that have
bioaccumulative, carcinogenic, teratogenic, or mutagenic potential,
then an integrated approach with both chemical specific analyses and
whole effluent analyses may be appropriate. Once the basic approach
is selected, screening methods may be used in a preliminary fashion to
estimate loadings, to identify and quantify processes influencing pol-
lutant behavior, and to estimate pollutant concentrations in the receiv-
ing water.
Technical Considerations
TMDL process
19
-------
Draft 05115/90
Mathematical models
Model characteristics
The use of national or site-specific criteria in computing TMDLs may
require the selection and use of a mathematical model. Models which
have been applied to point and nonpoint pollution sources are sum-
marized in Appendix D, Tables D-l and D-2. While it is beyond the
scope of this guidance to provide a detailed rationale for model
selection, it is appropriate to summarize the type of models available
and their applicability.
Models can be characterized in numerous ways such as data require-
ments, ease of application, etc. This section summarizes models based
on four categories: temporal characteristics, spatial characteristics,
specific constituents and process simulated, and transport processes.
Temporal characteristics - This includes whether the model is
steady-state (constant inputs and outputs), time averaged (for
example, tidally-averaged), or dynamic. If the model is
dynamic, an appropriate time step needs to be selected. For
example, streams with their small residence times may re-
quire short time steps (hourly or less) while lakes, which typi-
cally have residence times in excess of weeks, can generally
be modeled with longer time steps (e.g., daily or more).
Similarly, loads from NPS models are often lumped together
into event or annual loadings.
Spatial characteristics - This includes the number of dimen-
sions simulated and the degree of spatial resolution. In most
stream models, one-dimensional models are used since typi-
cally vertical and horizontal gradients are small. For large
lakes and estuaries, two- or three-dimensional models may be
more appropriate because both vertical and horizontal con-
centration gradients commonly occur. Segmented or multi-
ple catchment models may be more appropriate for
heterogeneous watersheds, whereas, lumped-single catch-
ment models are more appropriate for homogeneous or less
complex situations.
Specific constituents and processes simulated - Models vary
in the types of constituents and processes simulated and in
the complexity of the formulations used to represent each
process. For example, simple DO models include only
reaeration and BOD decay while more complex models in-
clude other processes such as nitrification, photosynthesis,
and algal respiration.
Transport processes - These include advection, dispersion,
runoff, interflow, anu rhe effects of stratification on these
processes. Most river models are concerned only with
downstream advection and dispersion. Lake and estuary
models may include advection and dispersion in one or more
dimensions, as well as the effects of density stratification. For
toxic modeling, it may be important to use models which ac-
count for near-field mixing since many of these pollutants
may exert maximum toxicity close to the point of discharge.
20
-------
Draft 05115190
To incorporate both point and nonpoint sources into
TMDLs, it will be important to consider integrated water-
shed models.
Model selection
A model should be selected based on its adequacy for the intended use,
for the specific waterbody, and for the critical conditions occurring at
that waterbody. While the selection of an appropriate model should
be made by a water quality analyst, it is useful for program managers
to be familiar with the decisions which must be made. Four basic steps
have been identified that an analyst would go through to select an
appropriate model:
Identify models applicable to the situation.
Define the appropriate level of analysis.
Incorporate practical constraints into the selection
criteria.
Select a specific model.
Identify models applicable to the situation. An obvious choice for
narrowing the selection of an appropriate model is based on the
waterbody type (river, estuary, or lake) and the type of analysis
(BOD/DO, toxics, etc.) A preliminary list of models may also be
screened by selecting models which consider the appropriate con-
stituents and processes that are important for the pollutant being
studied.
Define the appropriate level of analysis. The four levels of models are:
Simple calculator models - These include dilution and
mass balance calculations, Streeter-Phelps equations and
modifications thereof, analytical solutions to transport
equations, steady-state nutrient loading models, regres-
sion models, and other simplified modeling procedures
that can be performed on desk top calculators.
Steady-state computer models - These models compute
average spatial profiles of constituents along a river or es-
tuary assuming everything remains constant with time, in-
cluding loadings, upstream water quality conditions,
stream flow rates, meteorological conditions, etc.
Ouasi-dyr^mif; models - These models are a compromise
between steady-state models and dynamic models.
Quasi-dynamic models assume most of the above factors
remain constant, but allow one or more of them to vary
with time, for example waste loading rates or stream flow
rates. Some of the models hold the waste loading and
flow rates constant, but predict effects such as the diur-
nal variations in dissolved oxygen due to algal photosyn-
thesis and respiration.
Dynamic models - These models predict temporal and
spatial variations in water quality due to varied loadings,
flow conditions, meteorological conditions, and internal
processes within the watershed or waterbody. Dynamic
21
-------
Draft 05115190
Multiple Discharges
models are useful for analyzing transient events (e.g., storms
and long term seasonal cycles) such as those important in
lake eutrophication analyses.
The above levels of analysis are listed in order of increasing complexity,
data requirements, and cost of application. In general, the more
complicated approaches should provide more detailed and more ac-
curate analyses, assuming enough data are available for proper model
calibration and verification. Selected models are classified according
to their level of analysis and spatial representation in Appendix D,
Tables D-3 and D-4.
In addition, lognormal probabilistic models and Monte Carlo simula-
tion techniques have been used to modify some of the above ap-
proaches. Probabilistic models use lognormal probability
distributions of model inputs to calculate probability distributions of
model output. Since this method does not incorporate fate and
transport processes, it can only be used to predict the concentration of
a substance after complete mixing and before decay or transformation
significantly alters the concentration. Monte Carlo simulations com-
bine probabilistic inputs with deterministic models. A fate and
transport model is run a large number of tunes based on randomly
selected input values. The output from these models are then rank
ordered to produce a frequency distribution. These frequency dis-
tributions may then be compared to instream criteria (e.g., criteria
maximum concentration (CMC) and criteria continuous concentration
(CCC)) to determine if water quality standards are met.
Incorporate practical constraints. In general, the analyst should con-
sider the data requirements for each level of analysis, the availability
of historical data, the modeling effort required for each level of
analysis, and available resources. Availability of historical data for
calibration and verification is one of the key cost savings considera-
tions.
Select a specific model. The analyst should consider model familiarity,
technical support and model availability, documentation quality, ap-
plication ease, and professional recognition and acceptance of a
model.
[NOTE: This paragraph will be expanded to include current information
on what EPA/ORD supports and provides training on.J
Complex TMDLs should be developed for waterbodies when the
mixing zones from multiple pollution sources overlap. The key con-
cern associated with multiple point or nonpoint pollution sources is the
potential for additive or synergistic impacts. A recommended proce-
22
-------
Draft 05115190
clure for evaluating toxicity from multiple discharges is summarized in
a technical support document.14 To perform this analysis, it may be
necessary to apply near-field mixing models for each outfall (mixing
zone analysis) in addition to a far-field model which considers pol-
lutants from numerous point or nonpoint sources (after the mixing
zone).
The total pollutant load to a waterbody consists of point, nonpoint, and
natural background sources. When the total load is such that any
additional loading to a waterbody would produce a water quality
standard violation, the total load should be allocated to the various
pollution sources. The allocation of loads should consider technical,
socio-economic, institutional, and political constraints. States are also
encouraged to consider public participation and comment when al-
locating loads to point and nonpoint sources. By involving the local
community at an early stage in the TMDL development process,
greater public support and consensus building for controls may be
developed.
Individual States use various load allocation schemes appropriate to
their needs and may specify that a particular method be used. Three
common methods for allocating loads equal percent removal, equal
effluent concentrations, and a hybrid method, are discussed below.
(Other methods are summarized elsewhere.1 )
The first method is equal percent removal and exists in two forms. In
one, the overall removal efficiencies of the sources are set so they are
all equal. In the latter, the incremental removal efficiencies are set
equal. This method is appropriate when the incremental removal
efficiencies are relatively small, so that the necessary improvement in
water quality can be obtained by minor improvement in treatment at
each point source, at little cost.
The second common allocation method specifies equal effluent con-
centrations. This is similar to equal percent removal if influent con-
centrations at all sources are approximately the same. However, if one
source has substantially higher influent levels, then equal effluent
concentrations will require higher overall treatment levels than the
equal percent removal approach.
The third commonly used method of allocating loads can be termed a
hybrid method. With this method, the criteria for waste reduction may
not be the same from one source to the next. One source may be
allowed to operate unchanged while another may be required to
Allocation of Loads
14 USEPA. 1985. Technical Support Document for Water Quality-based Toxics Controls. OW/OWEP and
OWRS. EPA-440/4-085-032, Washington, D.C. [Note: TSD is currently being revised -final due in mid
1990.]
15 USEPA. 1985. Technical Support Document for Water Quality-based Toxics Controls. OW/OWEP and
OWRS. EPA-440/4-85-032, Washington, D.C.
23
-------
Draft 05115190
Allocation Trading
Persistent and/or Highly
Bioaccumulative Pollutants
provide the entire load reduction. More generally, a proportionality
rule may be assigned that requires the percent removal to be propor-
tional to the input source loading.
Where appropriate and technically feasible, certain efficiencies may
be realized by trading allocation of loads. Such a practice is similar to
what would be done during the original allocation of loads between
point and nonpoint sources. The objective for trades between point
and nonpoint sources is to exchange increased control of one pollution
source (decreased loading) for no change in control of another pollu-
tion source. This type of trading has been applied most often to
phosphorus. For example, some publicly-owned treatment works
(POTWs) may agree to install urban run-off BMPs in lieu of increased
controls (e.g., advanced treatment) at POTWs.
Five criteria need to be met in order to consider allocation trades:
NFS and point sources must both contribute substantially to
pollutant loadings in matching constituents.
The cost of NFS control per unit abatement must be sig-
nificantly less than the marginal point source control cost.
Trades must target the same compound, or target the same
ecological problem (e.g., a phosphorus and nitrate trade
aimed at eutrophication).
A single agency must have authority to administer, monitor,
and perform program enforcement.
Effluents must be comparable so that increases in other pol-
lutants do not violate applicable water quality standards.
Most pollutant trades occur between point and nonpoint sources.
However, where effluents from two different point source dischargers
are comparable and consistent with water quality standards (including
antidegradation and antibacksliding regulations and policies), and
have minimum technology-based limits applicable to point sources,
trades may be acceptable between these two point sources.
The Dillon Reservoir (west of Denver, Colorado) is one example of
where point and NFS phosphorous loads are being traded. In this
example, the cost associated with point source reduction was $1.5
million per year and the cost associated with NFS controls was $0.2 to
$1.0 million per year. Because of these cost savings, pollutant trades
allowed the point sources to achieve reductions in phosphorus loads
to the Dillon Reservoir by controlling NPSs rather than expanding the
sewage treatment system.
Persistent and/or bioaccumulative pollutants require special attention
during analysis of toxicity and TMDL development. The primary
concern is that persistent pollutants may enter a waterbody at unhazar-
dous levels and may accumulate downstream from other sources.
24
-------
Draft 05115190
Potentially these pollutants may accumulate in sediments or aquatic
biota resulting in effects on survival or reproduction. They may also
cause risk to humans by exposure to hazardous chemicals through
drinking water or consumption of contaminated fish or shellfish.
Chemicals that bioaccumulate at high rates include metals, organic
compounds, and organometallic compounds.
Any chemical that has high potential for persistence and bioaccumula-
tion should be a matter of concern until it can be demonstrated that
there are no adverse environmental and human health effects resulting
from the discharge of that pollutant into receiving waters. The first
step in addressing bioaccumulative or persistent pollutants in effluents
is to determine whether or not such pollutants are present The second
step is to determine if such pollutants are hazardous. The final step is
to calculate an acceptable discharge rate. Procedures for assessing
and controlling risk have been addressed in technical support
documentation. Current technical guidance for wasteload allocation
summarizes a number of models which are appropriate for modeling
the fate and transport of toxics in streams/rivers, lakes, and estuaries.
In some cases, development of TMDLs may not be the most efficient
use of resources to manage water quality and a goal of zero discharge
may be appropriate.
Because of inherent variation in effluent and receiving water flows and
pollutant concentrations, specifying a concentration that must not be
exceeded at any time or place may not be appropriate. The format that
was selected for expressing water quality criteria for aquatic life con-
sists of recommendations concerning concentrations, durations of
averaging periods, and average frequencies of allowed excursions. Use
of this concentration-duration-frequency format allows water quality
criteria for aquatic life to be adequately protective without being as
overprotective as would be necessary if criteria were expressed using
a simpler format.
Duration of exposure considers the amount of time organisms will be
exposed to toxicants. It is expressed as that period of time over which
the instream concentration is averaged for comparison with criteria
concentrations. Frequency is defined as how often exposures that
exceed the criteria can occur during a given period of time (e.g., once
every ten years) without unacceptably affecting the community. To
account for acute toxic effects, States should adopt acute criteria
expressed as the criteria maximum concentration (CMC) occurring in
a one-hour averaging period. Similarly, chronic criteria expressed as
the criteria continuous concentration (CCC) should be developed as
toxicant concentrations which should not be exceeded over protracted
periods of time. EPA currently recommends that no longer than a
four-day averaging period be used. For the purposes of modeling, the
ambient concentration should not exceed the CMC more than once
Use of Two-number Criteria
16
USEPA. 1985. Technical Support Document for Water Quality-based Toxics Control. OW/OWEP and
OWRS, EPA-440/4-85-032, Washington, D.C.
25
-------
Draft 05115190
Sediment Issues
Control Measures
every three years. (If the biological community is under stress because
of spills, multiple dischargers, etc., or has a low recovery potential, or
if a local species is very important, the frequency should be decreased.)
Although these criteria were developed for application to low flow
conditions, it is important for States to develop NFS pollution controls.
Therefore, to address NFS loading, EPA recommends that the two
number criteria should be applied for all flow conditions. However,
States should adopt duration and frequency parameters to account for
the high flow, intermittent nature of nonpoint source loadings. For
example, a typical "loading" from a nonpoint urban runoff source may
not last for more than two days. As a result, the four day averaging
period may not be appropriate.
The problems associated with clean and contaminated sediment are
not the same. Clean sediment can impair fish reproduction by silting-
up spawning areas, and can increase turbidity. The major concerns
regarding contaminated sediment are pollutant releases to the water
column, bioaccumulation, and biomagnification. Criteria being
developed for sediments have centered on evaluating and developing
an understanding of the principal factors that influence the sedi-
ment/contaminant interactions with the water column (Equilibrium
Partitioning Approach). Through such an understanding, exposure
estimates of benthic and other organisms can be made. Chronic water
quality criteria, or possibly other lexicological endpoints can then be
used to predict potential biological effects.
In some cases, sediment criteria alone would be sufficient to identify
and to establish clean up levels for contaminated sediments. In other
cases, the sediment criteria should be supplemented with biological or
other types of analysis before clean-up decisions can be made. The
Science Advisory Board will be reviewing methods for establishing
sediment criteria for metal contaminants and procedures for estab-
lishing standardized bioassays in 1991.
Technology-based controls for traditional sources are minimum con-
trols mandated by the Clean Water Act which must be met by
municipal and industrial discharges. When technology-based controls
are not sufficient to meet the designated uses (applicable water quality
standards), the water is determined to be water-quality limited and
more stringent controls are needed to meet the water quality standard.
Water quality-based controls may be developed to reduce pollutant
loadings to meet instream criteria, typically through the TMDL
process and associated WLAs and LAs.
Both technology-based and water quality-based controls may be im-
plemented through the National Pollution Discharge Elimination Sys-
tem (NPDES) permitting process. Permit limits based on WLAs are
called water-quality based limits. Under section 304(1)(1)(C) and (D)
of the CWA, Individual Control Strategies (ICSs) were established for
26
-------
Draft 05115190
certain point source discharges of priority toxic pollutants. An ICS is
composed of an NPDES permit and supporting documentation to
demonstrate that the permit contains adequate controls. A TMDL is
considered to be adequate documentation for the ICS. All waters with
approved ICSs developed by the States are to be in compliance with
water quality standards by June 1992. In addition to permits for point
sources, States should implement practical controls for NPSs (e.g.,
BMPs). Common BMPs are listed in Table 3-1. These controls should
be based on LAs when sufficient data exist or to apply best professional
judgement to estimate limits where data are not available.
Once allowable loadings have been developed for specific point sour-
ces and applicable nonpoint sources, these loads must be incorporated
into NPDES permits. The WLA or LA provides a measure of effluent
quality that is necessary to protect water quality in the receiving water.
It is important to consider how the WLA or LA addresses variability
in effluent quality. For example, allocations for nutrients or bioac-
cumulative pollutants could be expressed as the required average
effluent quality because the total loading of these pollutants is of
concern. On the other hand, an allocation for toxic pollutants should
be expressed as a maximum value for the effluent because the con-
centration of these pollutants is of more concern than the total loading.
It is important to recognize that the duration and frequency with which
the required effluent quality level may not exceed are critical aspects
of an allocation as well.
Permit limits are designed to require a particular level of effluent
quality. Effluent quality is variable, and limits are set at a level so that
if the treatment facility maintains the desired level of performance, the
probability of exceeding the limits is very low (e.g., the probability is
less than or equal to 0.05). If limits are set too high, a facility not
meeting the desired level of performance would not exceed the limits
as determined by typical monitoring practices. If limits are set too low,
a facility meeting the desired level of performance would often exceed
the limits. In either case, determination of compliance and enforce-
ment would be compromised.
There is a significant risk of incorrectly enforcing a WLA or LA if
effluent variability and the probability basis for both the WLA or LA
and the permit limits are not considered. For example, a steady state
WLA or LA may specify an effluent value with the assumption that it
is a value never to be exceeded. The same value used as the daily
maximum permit limit could allow the WLA value to be exceeded
perhaps an unacceptable amount of time without observing permit
violations using typical monitoring requirements. Even more con-
Incorporating TMDLs/WLAs/LAs
into Permits
27
-------
Draft 05115190
Table 3-1. Best management practice activity matrix
(Adopted from Guide to Nonpoint Source
Pollution Control).
BMP
AGRICULTURE
Conservation tillage
Contouring
;
Contour stno cropping
Cover crops
Integrated pest management
Range and oasture management
0 rotations
Waste management practices
CONSTRUCTION A URBAN RUNOFF
Structural control practices
Nonvegetative soil staolization
Porous pavements
Runoff detention/retention
Street cleaning
Surface rougnening
SILVICULTURE
Limiting disturbed areas
Log removal tecnnioues
Ground cover
Removal of debns
Proper nandling ot haul roads
MIMNO
Water diversion
Underarms
Block-cut or haui-bacK
MULTICATEGORY
Buffer Strips
Grassed waterway
Devices to encourage infiltration
Interception/diversion
Material ground cover
Sediment traps
Vegetative staoilizaoon/muicfiing
Source: USEPA. July. 1987, OWRS/CSD.
28
-------
Draft 05115190
fusion could result in translating a longer duration WLA requirement
(e.g., a four-day average) into daily maximum and average daily permit
limits.17
The procedures for developing water quality-based permit limits for
toxics at a source will normally result in new or more stringent water
quality-based limits than those contained in a previously issued permit.
In a limited number of cases, however, it is conceivable that less
stringent water quality-based limits could result. In these cases, permit
limits must conform to existing Federal regulations governing both
antidegradation (existing instream water uses shall be maintained and
protected) and antibacksliding (issuance of permit limits that are less
stringent than those contained in the existing permit is prohibited).
The pertinent regulations are 40 CFR Part 131 (131.12) and 40 CFR
Part 122 (122.44 and 122.62). Permit writers should keep apprised of
recent statutory or regulatory developments in this area.
Section 308 of the Clean Water Act and corresponding State statutes
authorize imposing of monitoring and data collection requirements on
the owner or operator of a point source discharge. Requirements may
include ambient and biological assessments, toxic reduction evalua-
tions, and in-plant monitoring, etc. The only limitation on this
authority is that there must be a reasonable need for the information,
the schedule and costs of the requirements must be reasonable, and
the request must meet the Paperwork Reduction Act. Needed data
collection may be initiated through a direct request (commonly
referred to as a "308 letter"), permit reporting requirements, or an
administrative order.
Permit requirements for data collection should be established when
longer term data (e.g., for several seasons) are needed and there are
insufficient data to set water quality-based limitations in the newly
issued permit. The permit should include a statement that the permit
can be modified or revoked and reissued if the data indicate violation
of State water quality standards. Several agencies have experienced
problems in negotiating study plans based on a generalized permit
requirement. If the permit requirement is non-specific (such as requir-
ing the development and execution of a plan of study) minimum
requirements should be included.
Antidegradation and antibacksliding
Data collection
17 The reader is referred to the Permit Writer's Guide to Water Quality-based Permitting for Toxic Pollutants
(July, 1987) and Technical Support Document for Water Quality-based Toxics Control for additional
information on deriving actual permit limits.
29
-------
Draft 05115190
Nonpoint Source Controls - BMP
Effectiveness Strategy
In order to manage waterbodies with NFS pollutant loads. States
should implement BMPs at geographically targeted pollution sources.
In some instances it is difficult to ensure, a priori, that implemented
NFS controls will achieve expected load reductions. BMP failure may
be due to an ineffective BMP or poor implementation. That is, a BMP
may not achieve expected load reductions because either the BMP did
not work or it was not implemented as designed. The latter case may
result from the lack of acceptance among participants such as in-
dividual land owners. Key components of a NFS control program
would include the following:
An analysis of institutional resources and capabilities.
Choosing priority areas for implementation efforts
(geographic targeting).
Developing an implementation strategy which accounts for
site-specific factors.
To ensure that BMPs are meeting the objectives established during the
development of TMDLs and LAs, States should adopt effectiveness
strategies. These strategies would describe NFS load reduction goals
and the procedure for reviewing and revising BMP controls. Since
many State agencies rely on local authority, grant conditions, cost
sharing agreements, cooperative agreements, etc. with other agencies
(e.g., Soil Conservation Service) to help implement controls, States are
encouraged to work with these agencies to implement workable
strategies. These strategies would allow State program managers to
monitor TMDL and LA effectiveness. At a minimum the information
a program manager needs to audit a TMDL includes:
Baseline BMPs for specific NPSs, including load reduction
strategies, percent of strategies to be achieved, and a tracking
measure/system for BMP implementation.
Appropriate biological, physical, chemical, and BMP effec-
tiveness monitoring (including why, when, where, what and
how to sample) to evaluate overall progress towards attaining
designated uses.
Time frame/schedule for implementation and evaluation of
targets, and achieving applicable water quality standards.
Excerpts from the State's section 319 management program.
The documentary information and assumptions used to develop the
TMDLs, WLAs, and LAs would also be made part of the BMP
effectiveness strategy.
Under the CLean Lakes Program (section 314), TMDLs are required
as a condition of the grant application for funding State projects.
30
-------
Draft 05/15190
Phased Approach for TMDLs
For setting TMDLs, an analyst needs to have sufficient information to
calculate the loadings from both point and nonpoint sources. Ade-
quate site-specific information is needed to calibrate and verify math-
ematical procedures used during analysis. In general, more data are
needed to calibrate and verify procedures for nonpoint sources than
for point sources, and often, these data are not existing and readily
available. Therefore, a phased approach should be considered when
sufficient data do not exist to develop final TMDLs due to the difficulty
in quantifying or modeling NFS impacts. Such an approach would
include an estimated or provisional TMDL as a practical control
measure until sufficient data are obtained to establish a final TMDL
with full margin of safety.
The phased approach would provide an opportunity to implement
controls on traditional point sources and "first level" controls on non-
traditional sources such as storm sewers and combined sewer over-
flows (CSOs), and to estimate the effectiveness of BMPs in order to
establish the provisional TMDL. During this interim period, addition-
al time is available to collect the needed data and also opens oppor-
tunities to obtain other resources for data collection (e.g., NFS
dischargers, cooperative monitoring, increased funding, etc.)
The phased approach provides States with a means to address priority
waterbodies in troubled or threatened watersheds which would other-
wise not be managed. In addition, such an approach will demonstrate
that the States and EPA are taking action to improve water quality and
develop a database for use in preparing final TMDLs.
A phased approach (Figure 3-1) resulting in a full TMDL would
include the following steps:
Phase I
Establish/maintain point source controls.
Establish practical NFS controls using best professional
judgement (BPJ) and available data.
Begin collection of data on NFS loadings, etc.
Phase II
Develop provisional TMDL using NFS load/reduction es-
timates.
Phase III
Develop final TMDL.
Review/revise point source controls, if necessary.
Establish/revise NFS controls.
A more complete description of this approach follows:
31
-------
Draft 05115190
Targeted Waterbody
YES
Adequate
data to estimate
NPS loads and BMR
reductions
Develop final TMDL
with afull margin
bf-safetyvXYXvXvXvX
Establish/revise
and NPS controls
.'*' Establish/maintain pp|nt
source> controlsv !X
Establish praetlcal NPS Cbntrols
using best prof essionai
Judgement and available data
Begin collection of data
on MPS!lbadlrigs,\etc.
t
-.Deyelqp provisional
TMDL using NPS load/
. reductlbhXestrmateis ;
MONITOR
Refine NPS load estimates
Evaluate effectiveness
of point and nonpoint
source controls
PKASEIII
Develop final TMDL
'fleylew/revJse point sburcV
X controls, if ^necessary/ X
Establish/revise NPS
Monitor for Effectiveness
Figure 3-1 Phased TMDL Approach
32
-------
Draft 05/15190
Establish/maintain pnint source controls. EPA's surface water quality
strategy is to ensure that established levels of controls on traditional
point source discharges are maintained. In addition, where a pollutant
discharger is in violation of the water quality standard, the State is
expected to prepare a WLA and establish a water quality-based permit
with limits for that discharger. Also, where a group of dischargers are
the cause of water quality standard violations without the addition of
NPSs or background sources, these sources should have water quality-
based permits for each discharger allowing for a margin of safety and
NPS loadings.
States are not to employ the Phase I approach as a tactic to delay
implementation of needed water quality-based controls. Rather,
States are required to establish controls so that water quality standards
can be met once sufficient practical controls are established for non-
point sources.
Establish practical NPS controls using best professional judgement
and available data. In the process of developing a provisional TMDL
for geographically targeted waterbodies, States may not be able to
calculate actual NPS loadings or the effectiveness of NPS controls.
Therefore, it may be necessary to use professional judgement to estab-
lish BMPs based on reasonable estimates and available data. Since it
could be several years before the effects of initiated BMPs can be
determined, it is recommended that care should be taken to document
the objectives and approaches used to determine the needed BMPs in
a BMP effectiveness strategy.
Begin collection of data on NPS loadings, etc. To compliment the
practical controls implemented, States should design a monitoring
program within the geographical targeted waterbody. The primary
monitoring objectives are: 1) establish NPS loading estimates, 2)
evaluate effectiveness of the BMP controls, and 3) continue collecting
data from all sources including compliance monitoring incorporated
as part of a discharger's permit. These efforts can demonstrate that
the State is developing a data base of current information to review and
revise as needed, the control practices established. The program
design should also be included in the State's BMP effectiveness
strategy. Sufficient data should collected in order to develop final
TMDLs and refine NPS controls during Phase III.
Develop provisional TMDL. Once the above components of Phase I
have been established, States are in a position to develop a provisional
TMDL for review by EPA. A provisional TMDL would be approvable
by EPA even though specific load allocations may not have been
identified for NPSs since reasonable estimates were provided. As part
of the provisional TMDL, States would establish a time frame for
development of a final TMDL with a full margin of safety. The tune
frame, negotiated with Regional EPA offices, is to be consistent with
the BMP effectiveness strategy.
Phase I
Phase II
33
-------
Draft 05115190
Phase III
In general, States should complete Phase I and II activities within three
years. Once BMP implementation has been initiated, States should
implement data collection activities indentified during Phase I. Actual
monitoring activities are expedited to vary from waterbody to water-
body. However, States should emphasize the collection of data neces-
sary to complete a final TMDL and evaluate practical NFS controls.
Phase III should be initiated when either the time frame agreed upon
during Phase II has elapsed. Phase III should proceed prior to the
scheduled time frame if sufficient data have been collected to calculate
NPS loads and to develop a final TMDL with a full margin of safety.
EPA views the completion of provisional or final TMDLs and the
periodic review of final TMDLs as an essential part of its water quality
management objective. Changing land use, agricultural practices,
population demographics, etc. may result in the need to revise TMDLs.
As a result, all TMDLs should have a time frame, negotiated with EPA
Regional offices, for periodic review based on data collected from
monitoring.
34
-------
Draft 05115190
CHAPTER 4:
IMPLEMENTATION
As a foundation for all TMDLs, WLAs, and LAs prepared by the State,
EPA and the State should agree on the process that the States will use
to develop TMDLs, WLAs and LAs and prepare a written agreement
which describes these procedures. (See Appendix E for a general
EPA/State Agreement Outline.) Such an agreement promotes consis-
tency between projects and between States (i.e., how background data
are applied, how and which models are to be used, how TMDLs are
determined, how loads will be allocated, etc.)- By agreeing on the
procedures that the State will follow (as described in the State's CPP
and/or the State/EPA technical agreement), only a sample of TMDLs,
WLAs, and LAs need to be reviewed in depth by EPA. This sample
in-depth review is to ensure that the State is following the agreed-upon
procedures and that the TMDLs, WLAs, and LAs are acceptable. If
a problem is found, all TMDLs, WLAs, and LAs may be reviewed in
greater detail. For any waterbody where developing wasteload alloca-
tions or load allocations is more complex or critical to the approval of
a large construction project, a major permit, or large expenditures of
Federal resources, the Regional office may, as its option, require the
State to submit additional information describing the proposed
project. In either event, the Regional office and the State should reach
an agreement on the level of detail that is appropriate.
Each year the EPA Regional office and the States should reach an
agreement on work plans for developing TMDLs as part of the State's
annual section 106 and 205(j) grant negotiations. To accomplish this,
each State should prepare a TMDL/WLA/LA element in its annual
work program that is submitted to EPA for approval. Waters iden-
tified in work plans should be based on State developed priorities.
These priorities must consider the severity of the impact and the uses
of the water. States may find it helpful to include additional informa-
tion in its work plans from the Waterbody System (WBS), such as:
segment descriptors (e.g., State ID numbers, River Reach File num-
bers or USGS hydrological codes if River Reach numbers are not
available), segment length, parameters causing the water quality
problems, uses supported or impaired, or special segment designations
(e.g., priority waters or national resource waters). For EPA review,
EPA/State Agreements
State Responsibilities
Development of Schedules and Timing
35
-------
Draft 05115190
(V
141
Ul
Uj
TMDL, WLA, and LA Development
enough additional information should be provided for comparison
with the list of waters required under section 303(d)(l) and submitted
in the State's section 305(b) report.
In order to effectively plan for TMDL development, States and
Regional offices are encouraged to establish schedules and time
frames in annual work plans and agree to long-term schedules for all
waters that will be addressed over the next five years. States would be
expected to allow some reserve capacity to address "hot spots" during
each year. This procedure:
Provides clear guidance to the States to establish a time
frame for the development, review, and revision of TMDLs.
Sets national consistency in developing TMDLs.
Establishes a basis for setting priorities.
Supports TMDL development for targeted waterbodies using
a geographical approach.
In accordance with the approved priority ranking for those waters and
the annual work program, each State develops its proposed TMDLs
for those pollutants that are expected to cause water quality standards
violations (including whole effluent toxicity) and for the approved list
of waters identified as needing new or revised TMDLs. The calcula-
tion of TMDLs are summarized in Figure 4-1. States are touseEPA's
guidance when developing TMDLs, copies of which may be obtained
from the Wasteload Allocation Coordinator in each Regional office.
For those TMDL projects that EPA reviews in detail, States should
prepare an abstract report describing each project and submit it to the
Regional office for review. This submission should contain: (1) the
proposed TMDLs, WLAs, LAs, and (2) supporting information that
the Region will need to evaluate the State's water quality analysis and
determine whether to approve or disapprove the proposed TMDLs,
WLAs, and LAs. Regions and States should reach an agreement on
the specific information that reports should contain and determine the
individual projects for which such reports are necessary as defined in
the EPA/State Technical Agreement.
Quality assurance (QA) and quality control (QC) requirements also
must be met. Specific technical QA/QC is necessary in the use of
environmental data and models. However, when using models, such
as wasteload allocation models which involve "real" environmental data
as well as parametric and mathematical relationships, model sensitivity
36
-------
Draft 05115190
Figure 4-1
Calculation of TMDLs
Approved lists of waters still needing
TMDLs ranked by priority
State
work programs will
provide priority TMDLs for
appropriate pollutants on a
timely basis?
State
modifies work
program to do needed
work on a timely
basis?
EPA does
needed work
TMDLs
correct and on
time?
EPA does
needed work
State
corrects
problems?
Approved TMDLs
incorporated into State
WQM plans
37
-------
Draft 05115190
Continuing Planning Process
Water Quality Management Plan
Public Notice and Participation
studies can help establish the levels of QA/QC required for specific
data. For example, the allowable range of uncertainty in the data can
be established through model sensitivity studies. This allowable range
of uncertainty may indicate, for example, the need for tight limits on
precision for a particular pollutant parameter. Further discussion is
provided elsewhere.
18 19 20
Each State is required to establish and maintain a continuing planning
process (CPP) as described in section 303(e) of the Clean Water Act.
A State's CPP must contain, among other items, a description of the
process that the State uses to identify waters needing water quality-
based controls, a priority ranking of these waters, developed TMDLs,
WLAs, and LAs, and a description of the State process used to receive
public review of each TMDL, WLA, and LA. This description may be
as detailed as the Regional office and the State feel is necessary to
adequately describe each step of the TMDL, WLA, and LA develop-
ment process. This process may be included as part of the EPA/State
Agreement for TMDL development (see page 35).
The State incorporates EPA approved TMDLs, WLAs, and LAs into
its Water Quality Management Plan (WQMP). The Water Quality
Management and Planning regulation"1 states that when EPA ap-
proves a TMDL submitted by a State under section 303(d), the TMDL,
WLA, and LA is to be deemed automatically incorporated into the
State's Water Quality Management Plan. The regulation treats this
submission and approval as the equivalent of a WQMP update, cer-
tification and approval.
In accordance with the Water Quality Management and Planning
regulation and as described in a State's CPP, TMDLs, WLAs, and LAs
should be made available for public review and comment. However,
States are encouraged to establish its own procedure for public par-
ticipation to assure that adequate coverage is given to decisions on
TMDLs. States and involved local communities should participate in
determining who (and which pollution sources) should bear the treat-
ment or control burden needed to reach allowable loadings. By involv-
ing the local communities in decision making, EPA expects that a
higher probability of successful TMDL implementation will result.
18
19
20
21
USEPA. September 1980. Guidelines and Specifications for Preparing Quality Assurance Project Plans,
QAMS-004/80, Washington, D.C.
USEPA. December 1980. Interim Guidelines and Specifications for Preparing Quality Assurance Plans,
QAMS-005/80, Washington, D.C.
USEPA. May 198- Guidance for Preparation of Combined Wor/w Quality Assurance Project Plans for
Environmental Monitoring, OWRS QA-1, Washington, D.C.
Federal Register, January 11,1985, page 1777.
40 CFR 35 and 130
38
-------
Draft 05/15190
The State should issue a public notice offering an opportunity for a
public hearing pertinent to the TMDL under review, however, if no
interest is shown as a result of the public notice, it is possible to waive
the hearing. It is also possible to include WLA and LA decisions in
conjunction with public notices and hearings on NPDES permits,
municipal wastewater treatment works, water quality standards
revisions, and WQMP updates. Each notice should identify TMDLs,
WLAs, and LAs as part of the subject matter.
Also, if a State feels that the water quality-based controls are critical
or if they anticipate that they may be controversial, the State should
involve the EPA Regional office as well as the public early in the
process and continue to involve them throughout the process rather
than waiting until WLAs are submitted to EPA for approval. (See
Appendix F for an example of a letter submitting a TMDL, WLA, and
LA to EPA for approval and the information to be included with the
letter to facilitate EPA review.)
Reporting section 303(d) lists of waters still needing TMDLs and
expected loads is required under 40 CFR 130.7 to be reported to EPA.
These lists should compliment EPA/State Agreements and the CPP,
and be incorporated into the WQMP.
Specific responsibilities of the State are to:
As the first priority, States should collect and analyze
data as needed to make water quality management
decisions:
- Identify: (a) waters still needing TMDLs, including high
quality waters, and (b) waters most needing water quality-
based and nonpoint source controls, or other actions to
prevent or reverse an impairment of the designated use.
- Develop needed water quality-based controls for both
conventional and toxic pollutants. For toxics, use both
the pollutant specific and the biomonitoring techniques,
as appropriate.
Ensure that needed environmental data are provided to
EPA, including appropriate assessment data; ap-
propriate screening data; and all regulatory data includ-
ing data needed for approvals of water quality standards
and TMDLs/WLAs/LAs.
Ensure that appropriate quality assurance/quality control
procedures are used for all data used in State decision
making and for all data reported to EPA, including data
reported by dischargers.
Reporting
Specific Responsibilities
39
-------
Draft 05/15190
EPA Responsibilities
TMDL Review and Approval
EPA reviews the State's annual work plans for developing TMDLs as
part of the State's section 106/2050) work program. If the EPA
Regional office disapproves a State's list of waters and/or loads need-
ing new or revised TMDLs, then the Region (working closely with the
State) identifies those waters and loads within the State where new or
revised TMDLs are necessary to implement the applicable water
quality standards. If EPA disapproves a State's priority ranking of
these waters, the Region and State are to negotiate acceptable revisions
to the priority ranking. If the State chooses not to develop the needed
TMDLs for appropriate pollutants on timely basis, EPA is under
obligation to develop the TMDLs in cooperation with the State. This
will be done by focusing available EPA resources on the most critical
water quality problems. The TMDL, WLA, and LA review/approval
process by EPA is summarized in Figure 4-2.
To meet the requirements of section 303(d) and the Water Quality
Planning and Management regulation (40 CFR 35 and 130), EPA must
review all TMDLs for approval or disapproval. EPA may tailor its
review to what is reasonable and appropriate; that is, where a State has
clearly described its process in its CPP (and EPA/State Technical
Agreement), EPA may conduct an in-depth review of a sample of the
State's TMDLs, WLAs, and LAs to determine how well the State is
implementing its approval process and give a less detailed review of
the remaining TMDLs, WLAs, and LAs. This review of samples of the
State submissions, in conjunction with a less detailed review of all other
TMDLs, WLAs, and LAs submitted to EPA by the State, will provide
a reasonable basis for EPA approving or disapproving individual
TMDLs, WLAs, and LAs. The in-depth sample review may include
TMDLs, WLAs, and LAs supporting major construction projects and
other major control measures." For those States that do not have an
approved WLA process, Regions are expected to conduct in-depth
reviews of all of the proposed TMDLs. When Regions review the State
TMDLs, they should also consider how well the States are following
the EPA technical guidance for conducting wasteload allocations.
In either case, EPA must, at a minimum, determine whether the State's
proposed TMDLs are "established at a level necessary to implement
the applicable water quality standards with seasonal variations and a
margin of safety that takes into account any lack of knowledge concern-
ing the relationship between effluent limitations and water
quality." No WLA or LA will be approved if it will result in a water
quality standard being violated, or, in the case of waters whose quality
exceed that necessary for the CWA 101(a)(2) goals, results in a lower-
22
23
Federal Register, January 11,1985, page 1777.
CWA section 303(d)(l)
40
-------
Figure 4-2 Review/Approval Procedure for State TMDL/WLA/LA
State/EPA Agreement
on Technical Procedures
State CPP Approved
by EPA
EPA Approved List of
Waters, by Priority,
Still Needing TMDLs
State Develops TMDLs/
WLAs/LAs Where Needed
Region May Assist State In
Developing TMDLs/WLAs/LAs
State Issues Public Notice
on TMDLs/WLAs/LAs; Holds
Hearing If Warranted. Submits
to EPA for Approval.
TMDL/WLA/LA
Acceptable
to EPA
No
EPA Approves TMDL as
Being Developed In
Accordance with
Section 303(d)
EPA Develops TMDL/WLA/LA
and Issues Public Notice
Seeking Comments. EPA Makes
Revisions as Needed and
Sends to State
i
State Includes Approved
TMDL/WLA/LA In:
NPDES Permits
BMP Controls
WQM Plan Update
I
-------
Draft 05115190
Tracking
Program Audits
ing of water quality unless the applicable public participation, inter-
governmental review, and baseline ^control requirements of the an-
tidegradation policy have been met.
24
EPA must either approve or disapprove the State's TMDL, WLA, or
LA within 30 days after submission by the State. An approved TMDL,
WLA, or LA is "certified" by the EPA as having been developed in
accordance with CWA section 303(d) and a letter of such approval is
transmitted to the State.
If EPA disapproves a State's TMDL and the State does not agree to
correct the problems, then EPA shall, within 30 days of the disapproval
date, establish such TMDLs as necessary to implement the water
quality standards. However, the Region should inform the State that
EPA would prefer to have the State develop the TMDLs, since the
short time available for EPA's establishment of the TMDLs would
likely necessitate using simplistic and overly conservative techniques
in developing the TMDLs and also because negative publicity might
arise should EPA be forced to step in.
The primary purpose of tracking TMDL development is for EPA to
assess the progress towards meeting the goals and requirements of
section 303(d) as well as other sections of the CWA. To measure this
progress, an increased emphasis has been given to measuring environ-
mental results.
To assist States in the water quality assessments, EPA has developed
the Water Body System (WBS). The WBS provides a geographically
based framework for entering, tracking, and reporting information on
the quality of individual waterbodies as they are defined by each State.
The primary function of the WBS is to keep track of water quality
assessments and the water quality status of waterbodies, including
causes and sources of use impairment. As a convenience to the States,
the WBS has been modified to include data fields on whether TMDLs
are still needed or are in place. The program is designed to help States
comply with the reporting requirements under sections 314(a), 319(a),
and 303(d). Once initial information concerning the identification and
status of waterbodies is entered into the system, the burden of sub-
sequent reporting will be reduced as States will need only to update
information.
EPA expects to measure performance on the basis of environmental
results and administrative goals by means of program audits. To
achieve this performance measurement EPA will periodically conduct
questionaire surveys of State water quality programs. These program
24 40 CFR 131.12
42
-------
Draft 05115190
audits will serve to determine where additional training or other assis-
tance may be needed and to determine implementation of program
objectives.
EPA Headquarters and Regional offices are available to provide
technical assistance and advice to the States in developing TMDLs,
WLAs, and LAs. EPA Headquarters provides for training and assis-
tance on modeling and the WBS.
EPA Headquarters is responsible for developing associated program
guidance, technical support with assistance from Research
Laboratories, and producing reports resulting from the section 30S(b)
assessment which includes the section 303(d) listing requirement.
EPA Headquarters is responsible for seeing that the mandates regard-
ing TMDLs in the CWA are carried out, providing oversight of the
Regional offices and the States, developing wasteload allocation pro-
gram policy and guidance, supporting the development of computer
software for calculating TMDLs, developing technical guidance docu-
ments and providing technical training and assistance.
Specific responsibilities of EPA Headquarters are to:
Prepare guidance and ensure that technical training and
technical assistance is available for monitoring, water
quality analysis, and data reporting.
Perform national assessments and evaluate the national
water quality effects of CWA programs.
Make national data systems more useful for national,
regional, and State managers by upgrading and cross-
linking the existing systems and developing interactive
data retrieval and analysis mechanisms for line managers.
Continue support of the River Reach and Industrial
Facility Discharge files.
Ensure that appropriate quality assurance/quality control
procedures are used in all national data collection efforts
and provide needed laboratory capability for national
studies of pollutants requiring special analyses, e.g.,
dioxin.
Prepare Headquarters budget requests, and in consult-
ation with the Regions, prepare requests for regional and
State water quality monitoring and analysis programs.
Peer review major agency program activities involving
water monitoring and consult with other program offices
on water monitoring activities.
Technical Assistance and Training
Guidance Documents and Reports
EPA Headquarters Responsibilities
43
-------
Draft 051 IS 190
EPA Regional Responsibilities
The EPA Regional offices are responsible for assisting Headquarters
in developing policy and guidance and distributing this policy and
guidance to the States, awarding grants to the States to provide them
with resources for developing and implementing wasteload allocations,
and providing technical assistance i.> the States. In addition, the
Regional offices are responsible for reviewing and approving, or dis-
approving, each State's wasteload allocation process; the wasteload
allocation element of the annual section 106/205(j) work program; the
list of waters where TMDLs, WLAs, and LAs are needed; the priority
ranking of these waters; and specific TMDLs, WLAs, and LAs. The
EPA Regional offices are also responsible for reporting on State
implementation to Headquarters.
Specific responsibilities of EPA Regional offices are to:
Ensure that the appropriate regulatory monitoring is per-
formed by States, the Region, or dischargers needed for
developing and implementing water quality based controls
and identifying needed nonpoint source controls. This in-
cludes data required to identify waters needing water quality
based controls, data needed to develop controls, and data
needed to assess the effectiveness of controls. Ensure that
the developed controls are implemented, and provide con-
trols if the State fails to act in a timely manner.
Provide technical assistance and training to the States. En-
sure that each Regional office has the capability to conduct
water quality monitoring and analyses. For work involving
toxics, where feasible, the Region is expected to have a
capability in both the pollutant specific and the biomonitor-
ing approaches.
Ensure that appropriate quality assurance/quality control pro-
cedures are used for all regional and State water quality data
and for all data used in regional decision making including
data reported by permittees.
Perform regional water quality assessments primarily based
on State data, as needed to prepare Environmental Manage-
ment Reports.
Ensure that regional data systems are compatible with and do
not unnecessarily duplicate national data systems. Ensure
that data collected by the States and the Regions are entered
into the national system, including data needed to update the
Industrial Facilities Discharge File.
44
-------
Draft 05/15/90
APPENDIX A
SCREENING CATEGORIES
1. Waters where fishing or shellfish bans and/or advisories are currently in effect or are anticipated.
2. Waters where there have been repeated fishkills or where abnormalities (cancers, lesions, tumors, etc.) have been observed in fish or
other aquatic life during the last ten years.
3. Waters where there are restrictions on water sports or recreational contact.
4. Waters identified by the state in its most recent state section 305(b) report as either "partially achieving" or "not achieving" designated
uses.
S. Waters identified by the states under section 303(d) of the CWA as waters needing water quality-based controls.
6. Waters identified by the state as priority waterbodies. (State Water Quality Management plans often include priority waterbody lists
which are those waters that most need water pollution control decisions to achieve water quality standards or goals.)
7. Waters where ambient data indicate potential or actual exceedances of water quality criteria due to toxic pollutants from an industry
classified as a primary industry in Appendix A of 40 CFR Part 122.
8. Waters for which effluent toxicity test results indicate possible or actual exceedances of state water quality standards, including narrative
"free from" water quality criteria or EPA water quality criteria where state criteria are not available.
9. Waters with primary industrial major dischargers where dilution analyses indicate exceedances of state narrative or numeric water
quality criteria (or EPA water quality criteria where state standards are not available) for toxic pollutants, ammonia, or chlorine. These
dilution analyses must be based on estimates of discharge levels derived from effluent guidelines development documents, NPDES
permits or permit application data (e.g., Form 2C), Discharge Monitoring Reports (DMRs), or other available information.
10. Waters with POTW dischargers requiring local pretreatment programs where dilution analyses indicate exceedances of state water
quality criteria (or EPA water quality criteria where state water quality criteria are not available) for toxic pollutants, ammonia, or
chlorine. These dilution analyses must be based upon data from NPDES permits or permit applications (e.g., Form 2C), Discharge
Monitoring Reports (DMRs), or other available information.
11. Waters with facilities not included in the previous two categories such as major POTWs, and industrial minor dischargers where dilution
analyses indicate exceedances of numeric or narrative state water quality criteria (or EPA water quality criteria where state water
quality criteria are not available) for toxic pollutants, ammonia, or chlorine. These dilution analyses must be based upon estimates of
discharge levels derived from effluent guideline development documents, NPDES permits or permit application data. Discharge
Monitoring Reports (DMRs), or other available information.
12. Waters classified for uses that will not support the "fishablc/swimmable" goals of the Clean Water Act.
13. Waters where ambient toxicity or adverse water quality conditions have been reported by local, state, EPA, or other Federal Agencies,
the private sector, public interest groups, or universities. These organizations and groups should be actively solicited for research they
may be conducting or reporting. For example, university researchers, the United States Department of Agriculture, the National
Oceanic and Atmospheric Administration, the United States Geological Survey, and the United States Fish and Wildlife Service are
good sources of field data and research.
14. Waters identified by the state as impaired in its most recent Clean Lake Assessments conducted under section 314 of the Clean Water
Act.
15. Waters identified as impaired by nonpoint sources in the America's Clean Water The States' Nnnpoint Snurre Assessments 1985
(Association of State and Interstate Water Pollution Control Administrators (ASIWPCA)) or waters identified as impaired or
threatened in a nonpoint source assessment submitted by the state to EPA under section 319 of the Clean Water Act.
16. Surface waters impaired by pollutants from hazardous waste sites on the National Priority List prepared under section 105(8)(A) of
CERCLA.
\l
45
-------
Draft 05115190
Figure A-1
USTING PROCESS
Review water quality data to
determine whether there
are historical WQS
violations, or trends
indicating the water is
threatened.
Do not list waterbody.
WQS
violations, or
threatened?
Yes
Determine whether all required
technology based pollution controls
(listed in 40 CFR 130.7(b)(1)(i,ii,iii)) are
implemented.
All
required
controls
implemented?
No
Yes
List waterbody, and
develop
TMDLs/WLAs/LAs
according to priority
ranking.
Run model to determine whether
implementing all of the required
pollution controls will meet WQSs.
Implementing the required
pollution controls is adequate to
meet WQSs.
What
are modeling
results?
Implementing the required
pollution controls is not
adeauateto meet WQSs.
Do not list waterbody.
List waterbody & develop
TMDLs/WLAs/LAs according
to priority ranking.
46
-------
Draft 05/15190
APPENDIX B
RELATIONSHIP TO OTHER PROGRAMS
Monitorina Procram
Ambient water quality monitoring is an information gathering tool used for almost all water quality analyses and
is required under section 104(a)(5) of the CWA. Monitoring can help identify waters needing TMDLs, quantify
loads, verify models, and evaluate overall water quality management (including BMP) implementation and
effectiveness. Once TMDLs, WLAs, and LAs have been developed for a given waterbody it is critical to follow-up
with monitoring to document improvement. Due to the complex nature of some waterbodies, one cannot expect
improvements immediately. Since the TMDL process is iterative, monitoring data can provide the information for
updating and revising current TMDLs, WLAs, and LAs. In addition to providing information for allocation of
assimilative capacities, monitoring can be used for setting permit conditions, compliance, enforcement, detecting
new problems and trends, etc.
Section 3Q4(H - Impaired waters
Section 304(1) of the CWA required States to submit lists of impaired waters and sources to EPA as a "one time"
effort. These lists of waters known as the short, long, and mini lists provide three types of designations for impaired
waters and source impacts. The mini list (section 304(e)(l)(A)(i)) is a list of waters the State does not expect to
achieve numeric water quality standards for priority pollutants (section 307(a)) after technology-based require-
ments have been met, due to point or nonpoint pollution sources. The long list (section 304(l)(l)(A)(ii)) is a
comprehensive list of waters that need additional pollution control actions whether due to toxicity or other
impairments; point or nonpoint sources; or toxic, conventional, or nonconventional pollutants. Waters meeting
designated uses, but not meeting the fishable/swimmable goals of the Clean Water Act are included on the long
list. A waterbody which meets its designated use criteria and does not meet fishable/swimmable criteria would be
listed on the section 304(1) long list but not on the section 303(d) list of waters needing TMDLs. It would be
appropriate for a State to include the information on all waters from its long lists and apply these data in developing
the section 303(d) list of waters that still do not meet applicable water quality standards. The short list (section
304(1)(1)(B)) is a list of State waters that are not expected to meet applicable standards after technology based
controls have been met, due entirely or substantially to point sources. A fourth list is the list of point sources of
priority pollutants which contribute to the impairment of waters identified on the short list.
Section 319 Nonpoint Source Program
One of the key initiatives of the 1987 Amendments to the Clean Water Act was the addition of section 319. The
establishment of a Nonpoint Source (NPS) Program is an inherent recognition of today's current water quality
programs. As a result of this section, States are required to assess their NPS pollution problems and submit that
assessment to EPA. The State assessments include a list of "navigable waters within the State which, without
additional action to control nonpoint sources of pollution, cannot reasonably be expected to attain or maintain
applicable water quality standards or the goals and requirements of this Act." Other paragraphs of section 319(a)
require the identification of categories and subcategories of NPS pollution which contribute to the identification
of unpaired waters, descriptions of the procedures for identifying and implementing BMPs and control measures
for reducing NPS pollution, and descriptions of State and local programs used to abate NPS pollution.
25 USEPA. March, 1988. Final guidance for Implementation of Requirements under section 304(1) of the
Clean Water Act as Amended. OWRS and OWEP, Washington, D.C.
47
-------
Draft 05/15/90
Since one of the requirements is to identify waters with impairments due primarily to NFS, a natural application
of section 303(d) is to develop TMDLs, WLAs, and most importantly LAs for these waters. Waters which meet
applicable water quality standards but do not meet the fishable/swimmable goals and requirements of the Clean
Water Act do not have the legal mandate under section 303(d)(l) to require TMDLs.
Section 305(V) - Water Quality Assessment26
Section 305(b) of the Clean Water Act establishes a process for developing information about the quality of the
Nation's water resources and a vehicle for reporting this information to EPA. Currently, each State, Territory, and
Interstate Commission develops a program to monitor the quality of its surface and ground waters and report the
current status of water quality biennially to EPA. This information is compiled, and EPA prepares a biennial
report to Congress. The 305(b) report has received additional attention in recent years due to the increased need
to assess environmental results. The section 305(b) report allows EPA to:
help determine the status of water quality;
help identify water quality problems and trends;
evaluate the causes of poor water quality and the relative contributions of pollution sources;
report on the activities underway to assess and restore water quality;
determine the effectiveness of control programs;
ensure that pollution control programs are focused on achieving environmental results in an efficient
manner;
determine the workload remaining in restoring waters with poor quality and protecting threatened
waters; and
maintain and update statutorily-required lists of waters identified under sections 303(d), 304(1), 314, and
319.
For each assessed waterbody under the waterbody specific information section of the section 305(b) report, States
are asked to provide information on the water quality limited status, nonattainment causes, nonattainment sources,
cause magnitude, and source magnitude. Much of this information results from section 305(b) waterbody
assessments and would provide useful information for meeting requirements of Clean Water Act section 303(d)
and 40 CFR 130.7. The WBS is a useful tracking tool designed to assist States in meeting these requirements.
EPA Criteria and Standards
EPA criteria published pursuant to section 304(a) of the Clean Water Act are guidance based on the latest scientific
information available on the effects of a pollutant on human health and aquatic life. States may adopt or modify
EPA's section 304(a) guidance in order to protect public health or welfare, and to enhance the quality of water
and to serve the purposes of the Clean Water Act. In addition to listing uses and criteria, State water quality
standards must contain an antidegradation policy that, at a minimum, ensures that the State maintains and protects
existing uses and the water quality necessary to protect those uses. EPA recommends establishing numerical values
wherever practical (section 303(c)(2)(B)). However, EPA recognizes many conditions for which narrative criteria
should be retained.
States may develop site-specific criteria in cases where background water quality parameters or aquatic organisms
differ from those used in the laboratory2 . The criteria adopted by States are water quality standards which are
enforceable requirements and are subject to public review. (Pubh'c hearings are required every three years. The
26 USEPA. 1989. Guidelines for the Preparation of the 1990 State Water Quality Assessment (section 305(b)
Report). OW/OWRS, Washington, D.C.
27 USEPA. 1983. Water Quality Standards Handbook. OW/OWRS, Washington, D.C.
28 Authority granted to States by CWA section 303(c).
48
-------
Draft 05115190
resulting standards are subject to EPA review and approval.) Once State criteria and standards are adopted, they
form a foundation of the State's water quality management program. (Refer to the Standards to Permits process
for further details.)
Marine and estuarine waters
In January 1990, EPA published its National Coastal and Marine Policy (NCMP), which states EPA's goals for
coastal and marine protection. They include:
recover full use of the nation's shores, beaches, and water;
restore the Nation's shell fisheries and salt-water fisheries;
minimize the use of coastal and marine water for waste disposal;
improve and expand coastal science; and
support international efforts to protect coastal and marine resources.
EPA's programs to protect ocean and coastal waters and the Great Lakes from nutrient and toxic pollutants
emanating from point and nonpoint sources are implemented under the Clean Water Act and the Marine
Protection, Research, and Sanctuaries Act (Ocean Dumping Act).
Marine and estuarine waters are, in many cases, the ultimate sink for pollutants which emanate from upland sources.
Estuaries and marine waters are particularly complex and it is difficult to predict pollutant fate and transport. To
address the increased complexity and effect on aquatic life, water quality management efforts must increase
accordingly. TMDLs can be a useful tool for management of marine and estuarine waters. Technical support is
currently being revised to support estuarine modeling.
Groundwater
Contaminated ground-water discharge to surface water may be a source of contaminants in water quality-limited
surface waters. While ground water and surface water are often treated as separate systems, they are in reality
highly interdependent components of the hydrologic cycle. Subsurface interactions with surface waters occur in
a variety of ways. In several studies, ground water discharge accounted for as much as 90% or more of stream flow
in humid regions. Therefore, the potential pollutant contributions from ground water to surface waters should be
evaluated when developing TMDLs.
NPDES permits and Individual Control Strategies
According to the Clean Water Act (section 402(a)), all discrete sources of wastewater must obtain a permit that
regulates the facility's discharge of pollutants. The Act's approach to control and elimination of water pollution
is focused on the pollutants determined to be harmful to receiving waters and on the sources of such pollutants.
Point sources are generally divided into two types: "industrial" and "municipal." Nationwide, there are ap-
proximately 50,000 industrial sources which include commercial and manufacturing facilities. Municipal sources,
also known as Publicly Owned Treatment Works (POTWs), number about 15,700 nationwide. Wastewater from
municipal sources results from domestic wastewater discharged to POTWs as well as the "indirect" discharge of
industrial wastes to sewers. In addition, EPA regulations designate several classes of sources as point sources for
NPDES purposes even though they may not have a discrete discharge (such as animal feedlots, fish farms, and
other aquatic production facilities, aquacultural operations). For purposes of permit issuance and oversight,
industrial and municipal sources are further divided into "major" and "minor" sources.
29 USEPA. . Technical Guidance Manual for Performing Wasteload Allocations, Book III - Estuaries.
49
-------
Draft 05115190
Permits for both industrial and municipal sources contain the following terms and conditions:"3
Standard conditions common to all permits,
Site-specific discharge or "effluent" limits,
Standard and site-specific compliance monitoring and reporting requirements, and
Other site-specific conditions that EPA deems necessary to adequately control the discharge.
Section 304(1)(1)(D) of the Clean Water Act requires the development of individual control strategies (ICSs) for
point source discharges of priority toxic pollutants to waters identified on the short list. (The short list is composed
of State waters for which applicable section 307(a) priority pollutant standards are not expected to be met after
technology-based controls have been met, due entirely or substantially to point sources.) In its section 304(1)
guidance, EPA requested that controls for all listed waters having known toxicity problems from any pollutant,
(including chlorine, ammonia, and whole effluent toxicity) be given the same priority as waters where only section
307(a) pollutants are involved. An ICS consists of an NPDES permit, to the extent possible, for each point source
listed and documentation that the permit has been developed with consideration of other dischargers. A TMDL
for the waterbody and a WLA for the individual dischargers would be considered as adequate documentation. An
approvable ICS would consist of effective NPDES permit limitations and schedules for achieving such limitations
if they cannot be achieved upon permit issuance, along with documentation which shows that the controls selected
are appropriate and adequate.
30 USEPA. 1989. A Primer on the Office of Water Enforcement and Permits and Its Programs.
OW/OWRS, Washington, D.C.
31 USEPA. 1985. Techncial Support Document for Water Quality-based Toxics Control. EPA-440/4-85-032.
32 USEPA. 1987. Permit Writer's Guide to Water Quality-based Permitting for Toxic Pollutants. EPA
440/4-87-005.
50
-------
Draft 05/15190
APPENDIX C
RELATIONSHIP TO OTHER GUIDANCE
Monitoring guidance
According to the Clean Water Act, States and Interstate Agencies, in cooperation with EPA, are to perform the
water quality monitoring necessary to establish and revise water quality standards, calculate TMDLs, assess
compliance with permits, and report on conditions and trends in ambient waters. The current program guidance
discusses the programmatic relationships of monitoring as an information collection tool for many of EPA's
program needs. With NPS pollution recently receiving additional attention, tools have been developed to monitor
and evaluate NPSs.34 Revised Monitoring Program Guidance will be available in late 1990.
Wasteload allocation technical guidance
States and EPA have developed WLAs for a number of years. As a result, extensive technical guidance has been
developed for preparing WLAs. In all, nine documents have been prepared and are summarized in Table B-l.
(Some of these documents are in draft form.)
Table B-l. Wasteland Allocation Guidance Documents
Book Guidance
I General Guidance (Program Guidance)
II Streams and Rivers
III Estuaries
IV Lakes and Impoundments
V Toxics Control Guidance
VI Design (Critical) Conditions
VII Permit Averaging
VIII Screening Manual
IX Innovative Wasteload Allocations
These guidance manuals have been developed to make improvements in methodology more widely available and
to provide a collection of procedures to support of development of WLAs. However, technical guidance for LAs
have not been developed to date.
Cooperative Monitoring
Cooperative monitoring involves shared efforts by individuals or groups in assessing water quality conditions and
developing local water quality-based controls. Cooperative arrangements are encouraged by the Clean Water Act
as referenced in section 104(a). Cooperative monitoring projects require careful planning and strong management
controls. Current guidance describes the factors to be considered in designing and implementing cooperative
33 USEPA. 1985. Guidance for State Water Monitoring and Wasteload Allocation Programs. OW/OWRS,
EPA 440/4-85-031, Washington, D.C
34 USEPA. 1987. Nonpoint Source Monitoring and Evaluation Guide (Draft). OW/OWRS, Washington,
D.C. [Monitoring Guide is currently being revised. New version due hi late 1990.]
35 USEPA. 1984. Planning and Managing Cooperative Monitoring Projects. OW/OWRS, EPA
440/4-84-018, Washington, D.C.
51
-------
Draft 05115190
monitoring projects so that specific provisions are made for the collection and analysis of scientifically valid water
quality data and so that the State water pollution control agencies have the necessary information for final review
and approval of all projects.
Cooperative monitoring projects can serve the same usefulness as other monitoring studies; however, they also
provide a mechanism to utilize additional resources. In addition to "tapping" additional resources for monitoring,
there are other incentives for States and the regulated community to cooperate, such as having more site-specific
data from which to develop site-specific, scientifically-based water quality criteria.
Technical Support Document for Water Quality-based Toxics Control
The Technical Support Document (TSD) for Water Quality-based Toxics Control presents recommendations to
regulatory authorities when they are faced with the task of controlling the discharge of toxic pollutants to the
Nation's waters. Included in this document are detailed discussions on EPA's recommended criteria for whole
effluent toxicity, a screening analysis methodology for effluent characterization, human health risk assessment, the
use of exposure assessments for wasteload allocations, and the development of permit requirements and com-
pliance monitoring. This TSD provides guidance for assessing and regulating the discharge of toxic substances. It
supports an EPA initiative involving the application of biological and chemical assessment techniques to control
toxic pollution and proposes solutions to complex and site-specific pollution problems. The TSD is currently being
updated and revised.
Permit Writers Guidance
The Permit Writer's Guide to Water Quality-based Permitting For Toxic Pollutants provides State and Federal
NPDES permit writers and water quality management staff with a reference on water quality-based permit issuance
procedures. This guidance presents fundamental concepts and procedures in detail and briefly refers to more
advanced toxics control procedures, such as dynamic modeling of complex discharge situations, which may not yet
be incorporated into many State programs. The Guidance is meant to explain aspects of water quality-based toxics
control in terms of what a permit writer currently needs to know to issue a water quality-based toxics control NPDES
permit.
The NPDES permits program is now focused on control of toxic pollutants. This document is directed at
supporting these toxics control efforts. Water quality problems related to conventional pollutants, such as those
associated with point source contributions to oxygen depletion, are addressed in other guidance documents.
The Permit Writer's guidance addresses three types of toxic effects: toxic effects on aquatic life, toxic effects of
human health, and toxic effects due to the bioaccumulation of specific chemicals. Each effect must be dealt with
on an individual basis using available data and tools. This guidance also catalogues the principal procedures and
tools available and presents them in the context of their relationship to permit issuance.
An integrated toxics control strategy using both whole effluent toxicity-based assessment procedures and pollutant-
specific assessment procedures is strongly for most permitting situations. Both procedures are needed to enforce
State water quality standards. Both have benefits and disadvantages, and so both are often needed in the toxics
control process. Chemical specific controls will almost always be needed to meet State standards for individual
toxicants and to assess an effluent for human health and bioaccumulation problems. Effluent toxicity testing will
usually be necessary to assess overall toxicity since effluents are often complex mixtures of pollutants.
36 USEPA. 1985. Technical Support Document for Water Quality-based Toxics Control. OW/OWRS &
OWEP, EPA-440/4-85-032, Washington, D.C.
37 USEPA. 1987. Permit Writer's Guide to Water Quality-based Permitting for Toxic Pollutants.
OW/OWEP, Washington, D.C.
52
-------
Draft 05115190
50
Nonpoint Source Guidance
Section 319 of the Clean Water Act establishes new direction and considerable Federal financial assistance for the
implementation of State NFS programs. NFS guidance encourages States to develop State Clean Water Strategies
for integrating and unifying the States' entire approach to water quality protection and clean-up. Three steps were
identified in the process: comprehensive assessment of impaired or threatened waters, target protection of waters,
and development of strategic management plans. EPA is encouraging States to develop NFS programs which build
upon related programs (e.g., Clean Lakes, National Estuaries, Stormwater Permits, Ground Water, Toxics
Controls, State Revolving Funds, and Wetlands) and to coordinate with other Federal Agencies.
Current guidance includes information on NFS requirements associated with section 319, principally development
of State Assessment Reports and State Management Programs. Provisions and grant application requirements
are also summarized.
Antidegradation and antibacksliding
Revisions to water quality standards may include revisions to the State's antidegradation policy or the procedures
through which the State plans to implement the antidegradation policy. Antidegradation policies and procedures
must ensure that the State maintains and protects existing uses and the quality of water necessary to protect those
uses.
Antidegradation policies must also ensure the protection of water quality above that necessary to maintain fish and
recreation, unless, after fulfilling public participation requirements, States can demonstrate that lower water quality
is necessary for important economic and social development in the vicinity of the water body. However, in no case
may a State allow water quality to deteriorate below that necessary to protect existing uses. Finally, antidegradation
policies must maintain and protect water quality for any outstanding national resource waters that the State
designates. Antidegradation implementation procedures must address how States will ensure that the permits and
control programs meet water quality standards and antidegradation requirements. States must provide an
opportunity for the public to review and comment on all aspects of water quality standard revisions. Any changes
to water quality standards are subject to EPA review and approval, and would include the review of the State's
antidegradation policy.
38 USEPA. 1987. Nonpoint Source Guidance. OW/OWRS, Washington, D.C.
53
-------
Draft 05115190
APPENDIX D
SUMMARY OF SELECTED MATHEMATICAL MODELS
Table D-1 WLA models and their applicability to different water quality problems.
Table D-2 Characteristics and Capabilities of Selected NFS Runoff Procedures and Models.
(after Review and Analysis of Available NFS and Integrated Watershed Models)
Table D-3 Level of analysis and spatial resolution of selected WLA models.
Table D-4 Characteristics and Capabilities of Integrated Watershed Models, (after Review and
Analysis of Available NFS and Integrated Watershed Models)
54
-------
Draft 05/15/90
Table D-l
WLA models and their applicability to different water quality problems.
Model
Name
Stream
D1ver
«ater Sody j water
Estuarv Lake
DO/800
Oual 1 tv
Eutroon-
i :3tlon
Prodi em
"3X1CS
Hand Calculation
Methods
WQAM
SNSIM
DOSAG-1
OOSA6-3
QUAL-II
QUAL-IIe
RECEIV-II
WASP
AESOP
HSPF
SLSA
MICHRIV
CTAP
EXAMS
MEXAMS
TOXIWASP
WASTOX
SERATRA
FETRA
TOOAM
TOXIC
CHNTRA
SEM
HAR03
FEDBAK03
OEM
MIT-ONM
EXPLORE-1
H.S. Chen
Steady-State
Nutrient Loading
Models
Chapra Dynamic
Loading node!
Larsen Dynamic '
Loading Model
CLEAN
CLEANER
MS.CLEANER
LAKECO
ONTARIO
WORRS
Grand Traverse
Bay Model
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X X X X
X
X
X X
X X
X X
X XX
X X X X
X X X X
XXX
X
X X
X X
X X
X X
X X
X
X
X
X
X X
X X
X X X
X X X
X X X
X XX
X X X
X X X
)
X
X
t
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
55
-------
Table D-2
Characteristics and Capabilities of Selected NFS Runoff Procedures and Models.
(after Review and Analysis of Available NFS and Integrated Watershed Models)
I
5
K*,
l-n
i
LAND USE/LOAD SOURCES / HYDROLdGY y^VATEH QUALITY/ TIME SCALE / DATA NEEDS / §CALE /
LOADING/SCREENING
PROCEDURES
Hydrosclence
A/M
EPA
Screening Procedures
WRENS
WLFNPS
3WMM - Level f
0
M/A
RUNOFF MODELS
Simplified SWMM
ARM
NPS
HSPF/PERLND t IMPLNO
o
CREAMS/CREAMS 2
ANSWERS
ACTMO
SWMM
STORM
MUNP
ILIUOAS/ORAINQUAL
OR3M
PRMS
o
o
o_
o
M
E/A
E/A
M
M
A
A
Notes: £-C.ptb,n,y included In model
Q-Gepablllly not enpllclly Included
but ten be usor defined
UM/Oocumenlitlon/3upporl
E -'Extensive
A - Adequele
M - Mlnlmel
-------
Draft 05/15/90
Table D-3
Level of analysis and spatial resolution of selected WLA models.
Model Name
Level of Analysis
Quasi
Hand Steady* Steady-
Calculations State State Dynamic
Spatial Representation
Dimensions
0-D 1-D 2-D 3-0
Hand Calculation
Methods
SNSIM
DOSAG-1
DOSAG-3
OUAL-II
RECEIV-II
WASP
AESOP
HSPF
SLSA
MICHRIV
CTAP
EXAMS
MEXAMS
TOXIWASP
WASTOX
SERATRA
FETRA
TOOAM
TOXIC
CHNTRA
SEM
HARD 3
FEDBAK03
DEM
MIT-DNM
EXPLORE- 1
H.S. Chen
Steady-State Nutrient
Loading Models
Chapra Dynamic
Loading Model
Larsen Dynamic
Loading Model
CLEAN
MS. CLEANER
LAKECO
ONTARIO
WQRRS
Grand Traverse
Bay Model
X XX XXX
X X
X X
X X
X X X2
X XX
xb xxx
X XXX
X X
X X
X X
X XXX
X XXX
X XXX
xb xxx
xb xxx
X XC
X X
X X
X XXX
X X
XX X
X XXX
X XXX
X X Xa
X X
X X Xa
X X
X X
X X
X X
X X
X XXX
X X
X XXX
X X
X XX
*Quas1 2-0
Hi daily-averaged dynamic estuary nodels
C2-D, vertical
57
-------
i
!
Table D-4
Characteristics and Capabilities of Integrated Watershed Models, (after Review and
Analysis of Available NFS and Integrated Watershed Models)
WATERBODY ft FLOW
CONDITIONS
WATER QUALITY
/TIME
SCALE
/
/
/ SPACE /
NEEDS / SCALE /
DATA
/
/
INTEGRATED
WATERSHED MODELS
H8PF
O
8WMM (RECEIV)
o
o
pns
UTM-TOX
o
M
SWAM
M/A
Nolei:
Included In modal
Q-C«p«blllly not xpllclly Included
but c«n ba ucer-dellned
Uie/Oocumenlillon/Suppoil
E -'Ententlv*
A - Adequate
M - Mlnlm.l
-------
Draft 05/15/90
APPENDIX E
GENERAL OUTLINE
EPA/STATE AGREEMENT FOR DEVELOPMENT OF TMDLs, WLAs, and LAs
Since conditions, procedures, and methodologies may vary between EPA Regions and their States, a general outline
of an example agreement is provided. This outline can be used in conjunction with the referenced technical
guidance documents to prepare EPA/State Agreements.
I. General
A. Purpose, Scope, and Authority
B. Statement of Policy
II. Water Quality Standards Considerations
A. General
B. Type of Stream Classifications
III. Allocation Procedures and Policies
A. Basic Approach for Establishing Boundaries for Effluent Limitations Determination
B. Determination of Effluent Limitations Using Water Quality Models
C. Determination of Effluent Limitations Using Other Analytical Tools
D. Special Case Policies
IV. Approval of TMDLs, WLAs, and LAs
V. Incorporation of Allocations into NPDES Permits
A. General
B. Priority Considerations
Appendix - State Continuing Planning Process (CPP)
59
-------
Draft 05115/90
APPENDIX F
EXAMPLE TRANSMITTAL LETTERS
The following letters are provided as examples to initiate the
review process and EPA's action. Included as examples are
the State's transmittal of completed TMDLs, WLAs, and LAs
to EPA requesting approval, EPA's letter approving the
State's TMDL, WLA, and LA, EPA's letter requesting addi-
tional information prior to approval, and EPA's letter of
disapproval.
60
-------
Draft 05115/90
EXAMPLE: STATE LETTER TO EPA REQUESTING
TMDL, WLA, AND LA APPROVAL
Regional Administrator
U.S. Environmental Protection Agency
Region
Street Address
City, State, Zip Code
Dear :
In accordance with 40 CFR 130.7(d) and section 303(d) of the Clean Water Act (33 U.S.C. 1251 et. seq.), the (State
water pollution control agency) submits for your review and approval the (wasteload allocations and/or total daily
maximum load) for the (discharges) to (waterbody) as being established at a level necessary to meet the applicable
water quality standard(s) with consideration of seasonal variation and a margin of safety.
This (wasteload allocation/total daily maximum load) was given public review during (date(s) of review period)
and approved by the State and will serve as the basis for NPDES permits, construction grants projects, and for
incorporation into the State's Water Quality Management Plan. To facilitate your review, we are enclosing the
calculations used to develop the TMDL, WLA, and LA.
Sincerely yours,
State Water Pollution Control Official
Enclosure3
39 Methods used, analyses, and calculations showing that the WLA is established at a level necessary to
implement the applicable water quality standards, (see 40 CFR 130.7(c)).
61
-------
Draft 05115190
EXAMPLE: EPA LETTER TO STATE APPROVING TMDL, WLA, AND LA
Chief, Water Division
State Water Pollution Control Agency
Street, Box Number
Citv State, Zip Code
Dear :
We have completed our review of the total maximum daily load/wasteload allocation for the (discharges) to
(waterbody) as submitted by your agency on (date). From our review, the effluent limits as established (e.g., oxygen
demanding substances, nutrients; general toxicity, toxic substances, etc.) for the defined segment are approved.
This total maximum daily load/wasteload allocation meets the requirements for total maximum daily loads and
wasteload allocations as specified under section 303(d) of the Clean Water Act and is hereby approved.
Sincerely yours,
Regional Administrator
62
-------
Draft 05115190
EXAMPLE: EPA LETTER TO STATE REQUESTING ADDITIONAL INFORMATION
Chief, Water Division
State Water Pollution Control Agency
Street, Box Number
City, State, Zip Code
Dear :
We have completed our review of the TMDL, WLA, and LA for the (discharges) to (waterbody) as submitted for
approval by your agency on (date). We have the following comments or questions:
1.
2.
3.
etc.
We cannot proceed in our review of your request for approval until a satisfactory reply is received on the above
comments or questions. A prompt response is requested to avoid disapproval.
Should the submitted TMDL, WLA, and LA be disapproved, EPA will, in accordance with section 303(d) of the
Clean Water Act, establish the TMDL, WLA, and LA for the (discharges) to the (waterbody) as defined and as
determined necessary to implement the applicable water quality standard(s).
If you have any questions, or need further clarification of our comments, please contact (namel on (phone
number).
Sincerely yours,
Regional Administrator
63
-------
Draft 05/15190
EXAMPLE: EPA LETTER TO STATE DISAPPROVING TMDL, WLA, AND LA
Chief, Water Division
State Water Pollution Control Agency
Street, Box Number
City, State, Zip Code
Dear :
We have completed our review of your response (dated) to our comments and questions (dated) regarding the
TMDL, WLA, and LA submitted by your agency (dated) for the (discharges) to (waterbody). We find the TMDL,
WLA, and LA not acceptable and is hereby disapproved for the following reasons:
1.
2.
3.
etc.
In accordance with section 303(d) of the Clean Water Act, EPA will, within thirty (30) days from this date, establish
the TMDL, WLA, and LA for (discharges) to (waterbody) necessary to implement the water quality standard(s)
including consideration of seasonal variation and a margin of safety.
Sincerely yours,
Regional Administrator
64
-------
Draft 05115190
LIST OF ACRONYMS
AT Advanced Treatment
BAT Best Available Technology
BCT Best Conventional Technology
BMP Best Management Practice
BODs 5-day Biochemical Oxygen Demand
BPJ Best Professional Judgement
CCC Criteria Continuous Concentration
CFR Code of Federal Regulations
CMC Criteria Maximum Concentration
CPP Continuing Planning Process
CSO Combined Sewer Overflow
CWA Clean Water Act
EPA Environmental Protection Agency
FR Federal Register
ICS Individual Control Strategy
LA Load Allocation
NCMP National Coastal and Marine Policy
NPDES National Pollution Discharge Elimination System
NFS Nonpoint Source
POTW Publicly Owned Treatment Works
QA/QC Quality Assurance/Quality Control
TMDL Total Maximum Daily Load
TRE Toxic Reduction Evaluation
TRI Toxic Release Inventory
TSD Technical Support Document
WBS Waterbody System
WLA Wasteload Allocation
WQMP Water Quality Management Plan
WWTP Wastewater Treatment Plant
65
-------
Draft 05115190
SELECTED OFFICES, DIVISIONS, BRANCHES, AND SECTIONS WITHIN EPA
General Contact
Phone Number
OW Office of Water 382-5700
OWRS Office of Water Regulations and Standards 382-5400
AED Analysis and Evaluation Division 382-5389
ITD Industrial Technology Division 382-7120
CSD Criteria and Standards Division 382-7301
AWPD Assessment and Watershed Protection Division 382-7040
Monitoring Branch 382-7056
Monitoring Management Section (TMDLs/WLAs)
Monitoring Analysis Section
Water Quality Analysis Branch 382-7046
Information Services Section
Special Studies Section
Exposure Assessment Section
Nonpoint Source Control Branch 382-7085
Clean Lakes Section
Nonpoint Source Control Section (BMPs/LAs)
OMEP Office of Marine and Estuarine Protection 382-7166
OWEP Office of Water Enforcement and Permits 475-8488
OMPC Office of Municipal Pollution Control 382-5850
ODW Office of Drinking Water 382-5543
OGWP Office of Ground Water Protection 382-7077
OWP Office of Wetlands Protection 475-7791
All area codes are 202.
66
------- |