EPA CONTRACT NO. 68-C8-0001
TC-4110
DRAFT REPORT
AMENDED SECTION 301 (h)
TECHNICAL SUPPORT
DOCUMENT
JANUARY 1991
PREPARED FOR:
OMEP
MARINE OPERATIONS DIVISION
OFFICE OF MARINE AND ESTUARINE PROTECTION
U.S. ENVIRONMENTAL PROTECTION AGENCY
WH-556F
WASHINGTON, DC 20460
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PREFACE
The following 1s a draft amended technical support guidance document
for the Clean Water Act Section 301(h) program. When finalized, this
guidance document will completely supercede the earlier Revised Section
301(h) Technical Support Document.
This guidance document, when finalized, will provide municipal
dischargers and the U.S. Environmental Protection Agency personnel with
technical guidance on preparing and evaluating applications for Section
301(h) modified permits. One of the primary purposes for revising this
guidance document Is to add guidance concerning proposed revisions to EPA's
Section 301(h) regulations (Part 125, Subpart 6) that the Agency Intends to
promulgate 1n the near future. EPA 1s revising the Section 301(h) regu-
lations primarily to Implement new Section 301(h) requirements Imposed by
the Water Quality Act of 1987.
This guidance document, when finalized, will be a general statement of
policy. It will not establish or affect legal rights or obligations. It
will not establish a binding norm and will not be finally determinative of
the Issues addressed. Agency decisions 1n any particular case will be made
by applying the law and regulations on the basis of specific facts and
actual actions.
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CONTENTS
Paoe
PREFACE 11
LIST OF FIGURES ' v11
LIST OF TABLES viil
EXECUTIVE SUMMARY x
INTRODUCTION 1
BACKGROUND 3
PURPOSE AND SCOPE 8
STATUTORY CRITERIA AND REGULATORY REQUIREMENTS 11
PART 122 16
PART 125 Subpart G 17
DEMONSTRATIONS OF COMPLIANCE BY PERMITTEES 27
APPLICATION FORMAT 28
REQUIRED DATA 30
APPROPRIATE ANALYSES AND PRESENTATION OF RESULTS 30
I. Introduction 32
II. General Information and Basic Data Requirements 34
A. Treatment System Description 34
1. Current, Improved or Altered Discharge 34
2. Description of Treatment/Outfall System 35
3. Primary or Equivalent Treatment Requirements 36
4. Effluent Limitations and Characteristics 37
5. Effluent Volume and Mass Emissions 39
6. Average Daily Industrial Flow 40
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7. Combined Sewer Overflows 41
8. Outfall/D1ffuser Design 41
B. Receiving Utter Description 43
1. Discharge to Ocean or Saline Estuary 43
2. Discharge to Stressed Haters 44
3. Seasonal Circulation 45
4. Oceanographlc Conditions 46
5. Previously Discharged Effluent 48
6. Ambient Hater Quality Conditions during Maximum
Stratification 49
7, Steady-state Sediment Dissolved Oxygen Demand and Oxygen
Demand due to Sediment Resuspenslon 53
C. Biological Conditions 53
1. Representative Biological Communities 55
2. Distinctive Habitats of Limited Distribution 57
3. Commercial and Recreational Fisheries 59
D. State and Federal Laws 60
1. Applicable Water Quality Standards 60
2. Hater Use Classification 60
3. Hater Quality Criteria at the ZID under Critical Conditions 61
4. Consistency with Coastal Zone, Marine Sanctuary, and
Endangered Species Laws 62
5. Consistency with oMer Stat* and Federal Laws 63
III. Technical Evaluation 64
A. Physical Characteristics of Discharge 64
1. Critical Initial Dilution 64
2. Dimensions of the ZID 67
3. Effects of Ambient Currents and Stratification on
Dilution and Transport of the Hastefield 69
4. Significant Sedimentation of Suspended Solids 72
5. Sedimentation of Suspended Solids 72
B. Compliance with Applicable Hater Quality Standards 73
1. Dissolved Oxygen 73
2. Farfield Dissolved Oxygen Depression 74
3. Dissolved Oxygen Depression doe to Steady Sediment Demand
and Sediment Resuspension 74
4. Suspended Solids 75
5. pH 75
6. Compliance with^Applicable Hater Quality Standards 79
7. Compliance with Subpart 125.61(b)(2) 80
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C. Impact on Public Hater Supplies 80
1. Presence of a Public Water Supply Intake 80
2. Effects on Such Intake 81
D. Biological Impact of Discharge 81
1. Presence of a BIP 84
2. Effects on Distinctive Habitats of Limited Distribution 88
3. Effects on Commercial and Recreation*} Fisheries 90
4. Other Impacts Hi thin or Beyond the ZID 93
5. Other Impacts for Discharges into Saline Estuarine Haters 96
6. Compliance with Subparts 125.62(a)-(
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EVALUATIONS OF COMPLIANCE BY U.S. EPA 133
DETERMINATIONS OF COMPLIANCE WITH SECTION 301(h) MODIFIED
PERMIT CONDITIONS 133
DETERMINATIONS OF COMPLIANCE WITH 301 (h) CRITERIA 136
EVALUATIONS OF PREDICTED CONDITIONS AND PREDICTED CONTINUED
COMPLIANCE 142
RE ISSUANCE OR TERMINATION OF SECTION 301(ti) MODIFIED PERMITS 146
PROCEDURES FOR REGULATORY ACTION 146
REGULATORY OPTIONS 147
REFERENCES 149
APPENDICES
APPENDIX A: PHYSICAL ASSESSMENT
APPENDIX B: WATER QUALITY ASSESSMENT
APPENDIX C: BIOLOGICAL ASSESSMENT
APPENDIX D: NAVIGATIONAL REQUIREMENTS AND METHODS
APPENDIX E: URBAN AREA PRETREATMENT PROGRAM REQUIREMENTS
APPENDIX F: WATER QUALITY-BASED TOXICS CONTROL
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FIGURES
Number Page
1 Wastefleld generated by a simple ocean outfall 65
2 01ffuser types and corresponding ZID configurations 68
3 Generalized depiction of changes In species numbers, total
abundances, and total blomass along a gradient of organic
enrichment 140
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TABLES
Number Page
1 Estimated pH values after Initial dilution 77
2 Toxic pollutants and pesticides as defined 1n Subparts
125.58(aa) and (p) 117
3 Summary of U.S. EPA marine water quality criteria 119
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ACKNOWLEDGMENTS
This draft guidance document was prepared by Tetra Tech, Inc. for,the
U.S. Environmental Protection Agency under the technical support contract
for marine discharge monitoring evaluations, U.S. EPA Contract No. 68->C8-
0001. Nr. Barry Burgan was the Work Assignment Manager. Major technical
contributors were Dr. Gordon Bllyard, Dr. Richard Harris, Dr,. William
Muellenhoff, Mr. James Pagenkopf, and Dr. A. Mills Soldate. Ms. Nancy
Musgrove and Ms. Karen Keeley compiled and edited preliminary draft
materials. Ms. Marcy Brooks-McAullffe edited the document and supervised
document production.
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EXECUTIVE SUMMARY
Section 301(h) of the 1977 Clean Water Act (CUA) allows the U.S.
Environmental Protection Agency (U.S. EPA) to Issue National Pollutant
Discharge Elimination System (NPOES) permits to publicly owned treatment
works (POTWs) for the discharge of less-than-secondary treated effluent.
One of the primary purposes of this document 1s to Identify changes to the
Section 301(h) regulations promulgated by EPA to Implement new Section
301(h) conditions Imposed by the Water Quality Act (WQA) of 1987 and to
provide technical guidance for Implementing those changes. Guidance Is also
provided on assessments and data analyses that applicants must perform to
satisfy regulatory requirements, and on methods that regulatory personnel
may use to evaluate compliance with those regulatory requirements. This
guidance 1s provided 1n three forms:
• Explanations of WQA Sections 303(a) through 303(g), and
resulting changes In the Section 301(h) regulations (I.e.,
all citations to Part 125)
• Technical guidance for implementing the new regulations, and
updated technical guidance for implementing regulations that
have not changed
• Guidance on the preparation of applications for reissuance of
Section 301(h) modified NPOES permits, on the evaluation of
those applications to determine compliance with the regula-
tions, and on the issuance and reissuance of Section 301(h)
modified permits.
The WQA of 1987 amended CWA Section 301 (h) in eight respects, as
summarized below. References to key affected subsections of the amended CWA
301(h) regulations, as renumbered, are shown in brackets.
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1) Section 301(h) modified discharges are prohibited from
Interfering, alone or In combination with pollutants from
other sources, with the attainment or maintenance of water
quality which assures the protection and uses listed 1n
Section 301(h)(2). (emphasis added) [125.62(f)]
2) The scope of monitoring Investigations Is limited to only
those Investigations necessary to study the effects of the
modified discharge. [12S.63(a)]
3) With respect to any toxic pollutant introduced by an
Industrial source and for which there 1s no applicable
pretreatment requirement in effect, POTVs serving populations
of 50,000 or more are required to demonstrate that sources
Introducing waste Into the POTW are in compliance with all
applicable pretreatment requirements, that the POTW will
enforce those requirements, and that the POTW has 1n effect a
pretreatment program which, 1n combination with the POTW's own
treatment processes, removes the same amount of toxic
pollutant as would be removed if the POTW were to apply
secondary treatment and had no pretreatment program for that
pollutant. [125.65, 125.58(g), 125.58(j), 125.58(q),
125.58(w), 125.58(b)]
4) At the time the Section 301 (h) modified permit becomes
effective, the POTW must be discharging effluent that has
received at least primary or equivalent treatment [as
defined in Subsection 125.58(r)], and that meets the water
quality criteria established under 304(a)(l) of the WQA after
Initial mixing In the receiving waters. [125.60, 125.58(r),
125.62(a)]
5) Section 301(h) modified permits nay not be Issued for
discharges into waters that contain significant amounts of
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previously discharged effluent from the POTW. [Regulations
not amended.]
6) Section 301(h) modified permits may not be Issued for
discharges Into saline estuarlne waters that exhibit stressed
conditions, regardless of the applicant's contribution to
those stressed conditions. Section 301(h) modified permits
may not be Issued for discharges into the New York Bight Apex
under any conditions. [125.59(b)(4), 125.62(f)]
7) Any POTW that had an agreement before 31 December 1982 to
use an outfall operated by another POTW which had applied for
or received a Section 301(h) modified permit could have
applied for Its own Section 301(h) modified permit within 30
days of enactment of the WQA. [Regulations not amended.]
8) Some provisions of the WQA do not apply to applications that
received tentative or final approval before enactment of the
WQA, but apply to all applications for renewal of Section
301(h) modified permits. [125.59(e)]
Among the eight major changes listed above, numbers 1, 3, 4, 5, and 8
are most Important to applicants and permittees that are not prohibited from
applying for a Section 301(h) modified permit under other provisions of the
amended regulations. The first major change requires POTWs to consider the
impacts of their discharge on the receiving environment and biota in
combination with pollutants from other sources. Previously, POTWs were
required only to consider whether their discharge contributed to such
impacts.
Change number 3 requires applicants to implement an urban pretreatment
program. This new statutory requirement complements the toxics control
program requirements in Part 125.66, and applies in addition to any
applicable pretreatment requirements contained in 40 CFR Part 403.
Dischargers may demonstrate compliance with Part 125.65 by demonstrating
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that an applicable pretreatment requirement is in effect, or by demonstrating
•secondary removal equivalency."
Applicable pretreatment requirements may be in the form of categorical
pretreatment standards promulgated by the U.S. EPA under CWA Section 307,
local limits developed 1n accordance with 40 CFR Part 403, or a combination
of both. It Is anticipated that most dischargers will be required to use a
combination of both approaches to satisfy Part 125.65 with respect to all
toxic substances Introduced Into the treatment works by Industrial sources.
Alternatively, a discharger nay demonstrate that Its own treatment
processes, In combination with pretreatment by Industrial dischargers,
achieves secondary removal equivalency. Dischargers are required to make
this demonstration whenever they cannot show that a toxic pollutant
Introduced by an Industrial discharger 1s subject to an "applicable
pretreatment requirement." Although secondary treatment 1s Intended to
control conventional, nontoxlc pollutants, a certain amount of each toxic
pollutant In the Influent 1s removed during the process. The Intent of this
part of UQA Section 303(c) 1s to ensure that a Section 301(h) discharger
removes that same amount of a toxic substance through Industrial pretreatment
plus the applicant's own treatment at less-than-secondary levels, as would
be removed 1f the applicant were to apply secondary treatment and no
pretreatment requirements existed for that pollutant. This demonstration
requires the use of a secondary treatment pilot plant to determine em-
pirically the amount of a toxic pollutant the would be removed from the
Influent 1f the applicant were to apply secondary treatment. For each
pollutant Introduced by an Industrial source, that applicant would then
demonstrate that Industrial pretreatment plus the POTW's own treatment
processes removed the same amount of pollutant as was removed by the
secondary treatment pilot plant.
Change number 4 requires all Section 301(h) dischargers to achieve a
minimum of primary or equivalent treatment, thereby establishing a primary
treatment floor for all marine and estuarine POTHs. It also requires all
Section 301(h) dischargers to meet the water quality criteria established
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under UQA Section 304(a)(l) after Initial mixing in the receiving waters.
•
Section 301(h) dischargers have always been required to meet state water
quality standards that are appropriate to local conditions, and that have
been approved by the U.S. EPA. For this reason, Section 301 (h) dischargers
are required first to demonstrate compliance with water quality standards,
and then to demonstrate compliance with water quality criteria only for
those pollutants for which no directly corresponding numerical water quality
standard exists. For example, 1f a water quality standard exists only for a
group of toxic substances, such as metals, applicants would also be required
to demonstrate compliance with the water quality criteria for Individual
metals (e.g., cadmium, lead, zinc) to demonstrate compliance with Part
125.60.
The Section 301(h) regulations were not amended with respect to change
number 5--rec1rculat1on and reentralnment of previously discharged effluent
from the POTW. However, POTWs that discharge Into receiving environments
where reentralnment Is likely must consider the possible effects of such
entrapment when demonstrating compliance with applicable water quality
standards, water quality criteria, and other Section 301(h) criteria.
Reentralnment 1s most often of concern in bays and estuaries where tidal
currents predominate, and where previously discharged effluent is likely to
be advected Into the ZID after the tidal currents reverse.
Change number 8 in the regulations "grandfathers" applicants that had
received tentative or final approval of their Section 301(h) modified
permits before passage of the UQA. Such applicants are "grandfathered" for
changes 1, 3, 4, and 5 above, but only for the term of the existing Section
301(h) modified permit. Applicants for reissuance of Section 301(h)
modified permits must demonstrate compliance with all applicable Section
301(h) criteria to qualify for renewal of the Section 301(h) modified
permit. Moreover, under Subpart 12S.59(e) applicants for new or reissued
Section 301(h) modifications (Including grandfathered applicants) must,
within 90 days of the effective date of the amended Section 301 (h) regu-
lations, submit to the Administrator additional Information regarding their
Intent to demonstrate compliance with Part 125.60 (I.e., primary treatment
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floor, compliance with water quality criteria) and Section 125.65 (I.e.,
urban area pretreatment requirements). Such applicants will then have 2 yr
to demonstrate compliance with Parts 125.60 and 125.65, or In the case of
some grandfathered applicants, until the time of application for permit
renewal 1f that time 1s more than 2 yr away.
In addition, definitions of primary or equivalent treatment, pretreat-
ment, categorical pretreatment standard, secondary removal equivalency,
water quality criteria, permittee, and New York Bight Apex have been added
to the amended Section 301(h) regulations, and definitions of Industrial
source, ocean waters, applications, and application questionnaire have been
changed.
New technical guidance given 1n this document primarily addresses major
changes numbers 1, 3, 4, and 5 above. Hence, It Includes the following:
• Guidance for assessing Impacts of the applicant's modified
discharge "alone or 1n combination with pollutants from other
sources"
• Guidance on methods for demonstrating compliance with urban
area pretreatment requirements
• Guidance on methods for demonstrating compliance with appli-
cable water quality standards and criteria
• Guidance for demonstrating that dilution water does not
contain significant amounts of previously discharged effluent.
Updated guidance that reflects technical advances made since publication of
the earlier version of this guidance document, the Revised Section 301(h)
Technical Support Document, 1s also provided for demonstrating compliance
with existing Section 301(h) regulations. Technical areas that have been
updated most extensively Include the physical and water quality assessments
and the discussion of navigational requirements.
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General guidance, new guidance, and updated guidance are provided 1n the
format of the Application Questionnaire, with supporting appendices as
warranted. General guidance Includes discussions of the types of demonstra-
tions that should be Included by applicants when responding to each
question. Detailed technical explanations of analytical methods that may be
used to demonstrate compliance with specific regulatory criteria are
provided 1n six supporting appendices. Methods for calculating Initial
dilution of the wastefleld are provided 1n Appendix A (Physical Assessment).
Detailed descriptions of analytical methods used to demonstrate compliance
with water quality regulations are presented In Appendix B (Water Quality
Assessment). These methods address suspended solids deposition, dissolved
oxygen concentrations, sediment oxygen demand, suspended solids concentra-
tions, effluent pH, light transmlttance, and other water quality variables.
Guidance for biological assessments, as represented by benthic community
evaluations, 1s presented 1n Appendix C. Navigational considerations for
sampling 1n estuarlne and coastal areas are discussed In Appendix D. The
new urban area pretreatment requirements and methods for demonstrating
compliance with them are described 1n Appendix E. Finally, additional
Information on water quality-based toxics control 1s presented in Appendix F.
Because of the extensive redundancy that existed between the Small and
Large Applicant Questionnaires In the 1982 regulations, a single Application
Questionnaire Is Included In the amended Section 301(h) Regulations. It
combines relevant questions from the two earlier questionnaires and Includes
new questions that address the changes 1n the Section 301(h) regulations.
In addition to providing technical guidance for responding to questions in
the Application Questionnaire, this document Identifies who must respond to
each question (I.e., large dischargers, small dischargers, or both). It
also discusses the levels of detail that are appropriate for responses by
dischargers of different sizes and Into different receiving environments.
Each application for a Section 301(h) modified NPDES permit is submitted
to, and reviewed by, the appropriate U.S. EPA Region. Having reached a
decision regarding an application for reissuance of a Section 301(h)
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modified permit, the Region nay reissue the Section 301(h) modified permit
with the same or different permit conditions, or deny the Section 301 (h)
modification. In the case of denial, the NPOES permit would then be
reissued by the U.S. EPA (or, In NPDES-delegated states, by the state) with
secondary treatment requirements. This document defines the conditions
.under which each of these actions 1s appropriate, and provides the Region
with guidance on procedures for reissuing and terminating Section 301(h)
modified permits. It does not provide guidance on the preparation of NPDES
permits, which has been published elsewhere (U.S. EPA 1986b).
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INTRODUCTION
Section 301(h) of the 1977 Clean Water Act (CWA) allows the U.S.
Environmental Protection Agency (U.S. EPA) Administrator, upon application
by publicly owned treatment works (POTWs) and with concurrence of the state,
to Issue National Pollutant Discharge Elimination System (NPDES) permits for
the discharge of less-than-secondary treated effluent. POTWs were eligible
to apply for such modified permits If they discharged to marine or estuarine
waters, and 1f they could demonstrate compliance with Section 301(h)
criteria and all other NPDES permit requirements.
Section 301(h) was amended In 1981 by the Municipal Wastewater
Treatment Construction Grants Amendments, and the deadline for submittal of
Section 301(h) applications was extended to 29 December 1982. In 1982, the
Revised Section 301(h) Technical Support Document (Tetra Tech 1982b) was
Issued. It identified the new regulatory requirements of Section 301(h) and
provided technical guidance on the preparation of Section 301(h) applica-
tions. A companion document, Design of 301(h) Monitoring Programs for
Municipal Hastewater Discharges to Marine Haters (Tetra Tech 1982a), was
also Issued in 1982. It provided guidance on the development and implemen-
tation of monitoring programs that would meet Section 301(h) requirements.
Section 301(h) was amended again by the Water quality Act (WQA) of
1987. That act did not extend the 1982 application deadline or reopen the
application process to POTWs that had not applied by the 1982 deadline.
However, it did amend Section 301(h) for POTWs already in the program. One
of the primary purposes of this document is to identify changes to the
Section 301(h) regulations promulgated by EPA to implement new Section
301(h) conditions imposed by the Water Quality Act of 1987 and to provide
technical guidance for implementing those changes. This document also
provides guidance on assessments and data analyses that applicants must
perform to satisfy all applicable regulatory requirements, and on methods
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that regulatory personnel may use to evaluate compliance with those regu-
latory requirements.
This document supercedes the Revised Section 301(h) Technical Support
Document. It Incorporates relevant guidance from that earlier document and
from more recent guidance documents produced under the 301(h) program since
1982. Design of 301 (h) Monitoring Programs for Municipal Vastewater
Discharges to Marine Haters remains relevant to the 301(h) program, although
much additional technical guidance Is now available (see Question III.F.I
under the section entitled "Appropriate Analyses and Presentations of
Results" below). The more recent guidance documents provide state-of-the-art
guidance on the collection, analysis, and Interpretation of monitoring data,
Including references for the most up-to-date laboratory and analytical
techniques. This more recent guidance and the general guidance provided In
the 1982 document provide a solid technical basis for the design and
execution of Section 301(h) monitoring programs.
This Amended Section 301(h) Technical Support Document 1s divided Into
two major sections: a main body of text and appendices. The main body of
text reviews the regulations Implementing Section 301(h) (I.e., Part 125
Subpart 6) and highlights proposed changes to those regulations made by EPA
to reflect the references to Section 301 (h) made by the 1987 WQA. It also
provides general technical guidance to dischargers on the preparation of
Section 301(h) applications for permit relssuance, Including general
discussions of the types of demonstrations that should be Included by
applicants when responding to each question In the application questionnaire.
For example, 1t specifies whether large or snail dischargers should respond
to a given question, and discusses the level of detail that 1s appropriate to
each. Methods that EPA personnel may use to evaluate compliance with
regulatory criteria are also discussed. The appendices contain detailed
technical explanations of the analytical methods that may be used to demon-
strate compliance with specific regulatory criteria (e.g., formulas to
determine dissolved oxygen concentration following Initial dilution,
detailed discussions of methods to demonstrate compliance with urban area
pretreatment requirements).
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The Section 301(h) regulations distinguish between large and small
dischargers, and that distinction Is maintained throughout this document.
Dischargers are considered to be large or small based on their effluent flow
and service population. Large dischargers are defined as POTWs that "have
contributing populations equal to or moire than 50,000 people or average dry
weather flows of 5.0 MGD (million gallons per day) or more." Small
dischargers "have contributing populations of less than 50,000 people and
average dry weather flows of less than 5.0 MGD." The definition In Subpart
125.58(c) further stipulates that estimates of "the contributing population
and flows shall be based on projections for the end of the five year permit
term. Average dry weather flows shall be the average dally total discharge
flows for the maximum month of the dry weather season."
BACKGROUND
Section 301(h) was amended by UQA Section 303, entitled "Discharges
Into Marine Waters." Section 303 Includes Sections 303(a) through 303(g).
The Section 301(h) regulations have been changed 1n response to these
statutory amendments, and guidance Is now needed to Implement the new
regulations. As background to providing such guidance, each of the
statutory amendments 1s summarized below, followed by a brief description of
the corresponding changes in the Section 301(h) regulations. Citations to
the Part 125, Subpart G regulations that appear in the discussion below
refer to the section numbers of the regulations as renumbered.
Section 303(a) amends Subsection 301(h)(2) to state that the modified
discharge "will not interfere a7one or in combination with pollutants from
other sources, with the attainment or maintenance of water quality which
assures protection of public water supplies and the protection and propaga-
tion of a balanced, Indigenous population of shellfish, fish and wildlife,
and allows recreational activities, in and on the water" (emphasis added).
This amendment strengthens the existing regulations to prohibit Section
301(h) discharges into receiving waters where pollutants from the discharge
would, in combination with pollutants from other sources, result in adverse
impacts to water quality, recreational activities, or the resident biota.
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In response to WQA Section 303(a), language was added to Subpart 125.-62(f) to
clarify this Issue. The new language makes clear that 1t 1s not sufficient
to demonstrate that the applicant's own discharge will not Interfere with
the attainment or maintenance of water quality as specified 1n the remainder
of Part 125.62. Applicants must now demonstrate compliance with Part 125.62
based on the combined effects of the applicant's modified discharge and
pollutants from other sources.
Under WQA Section 303(b), the scope of a Section 301(h) discharger's
monitoring program Is limited to "those scientific Investigations that are
necessary to study the effects of the proposed discharge." This limitation
1s applicable only to modifications and renewals of modifications that are
tentatively or finally approved after the date of enactment of the WQA.
Although the existing Section 301(h) requirements for monitoring programs
were already generally focused on the effects of the applicant's discharge,
this limitation was added to Part 125.63 of the regulations. This limitation
does not affect the precedent for developing monitoring programs on a case-
by-case basis.
WQA Section 303(c) 1s applicable only to large dischargers that
discharge toxic pollutants Introduced by industrial sources. It mandates
that for any toxic pollutant introduced by an Industrial source for which
there are no applicable pretreatment requirements in effect, the applicant
will demonstrate that sources introducing waste into the POTW are in
compliance with all applicable pretreatment requirements, the applicant
will enforce those requirements, and the applicant will demonstrate that the
POTW has in effect a pretreatment program which, in combination with the
POTW's own treatment processes, removes the sane amount of toxic pollutant
as would be removed if the POTW were to apply secondary treatment and had no
pretreatment program for the pollutant. This "secondary equivalency"
requirement places a technology-based standard on the discharge of toxic
pollutants by applicable Section 301(h) dischargers. Under this provision,
each such applicant must demonstrate, for each toxic pollutant introduced by
an industrial discharger, either that 1t has an "applicable pretreatment
requirement in effect" or that it has implemented a program that achieves
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"secondary removal equivalency." Section 303(c) also requires POTWs to
demonstrate that Industrial sources of toxic substances are In compliance
with all of their pretreatment requirements, Including numerical standards
set by local limits, and that those standards will be enforced.
*
To Implement HQA Section 303(c), Part 125.65 was added to the regula-
tions, definitions were added to Part 125.58, and existing definitions In
Part 125.58 were revised. Part 125.65 requires that an urban area pretreat-
ment program be Implemented by applicable POTWs to demonstrate that toxic
pollutants are being controlled. It also provides options for Implementing
that program. Definitions that are relevant to the urban area pretreatment
program and that have been revised or added to the regulations Include
"categorical pretreatment standard," "Industrial discharger" or "Industrial
source," "pretreatment," "secondary removal equivalency," and "water quality
criteria."
HQA Section 303(d), establishes a minimum of primary treatment (or Its
equivalent). "Primary or equivalent treatment" Is defined 1n Subsection
303(d)(2) as "treatment by screening, sedimentation, and skimming adequate
to remove at least 30 percent of the biological oxygen demanding material
and of the suspended sol Ids In the treatment works Influent, and disin-
fection, where appropriate." This subsection also mandates compliance with
federal water quality criteria (U.S. EPA 1980, 1985b, 1986a) for Section
301(h) dischargers.
To Implement WQA Section 303(d), Part 125.60 requiring a minimum of
primary or equivalent treatment was added to the regulations, and the
definition of "primary or equivalent treatment" stated In the WQA was
incorporated into the Section 301(h) regulations without change [see
Subpart 125.58(r)]. Subpart 125.62(a) of the regulations was also amended
to state that at and beyond the boundary of the zone of initial dilution
(ZID), applicants must meet all applicable water quality standards, and all
water quality criteria established under Subsection 304(a)(l) of the WQA
where no directly corresponding numerical water quality standards exist.
Hence, after demonstrating compliance with water quality standards [as was
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required under the 1982 Section 301(h) regulations], applicants need only
demonstrate compliance with those water quality criteria (If any) for which
no directly corresponding water quality standards exist.
Under WQA Section 303(e), Section 301(h) modified permits may not be
Issued 'for discharges Into marine waters where the dilution water contains
"significant amounts of previously discharged effluent from such treatment
works." Re-entra1nment of previously discharged effluent 1s often a
potential problem 1n receiving waters that exhibit poor flushing charac-
teristics, such as semi -enclosed bays or long, narrow estuaries. This
section also prohibits Issuance of Section 301 (h) modified permits for
discharges Into the New York Bight Apex, and for discharges Into saline
estuarlne waters unless those waters meet all of the following conditions:
• Support a balanced Indigenous population (BIP) of shellfish,
fish, and wildlife
• Allow for recreational activities
• Exhibit ambient water quality characteristics that are
adequate to protect public water supplies; protect shellfish,
fish, and wildlife; allow for recreational activities; and
comply with standards that assure the protection of such uses.
A Section 301 (h) permit may not be issued if any one of the foregoing
conditions does not exist, regardless of whether the applicant's discharge
contributes to departures from or retards recovery of such conditions.
Hence, WQA Section 303(e) prohibits Section 301(h) modified NPDES permits for
discharges into stressed saline estuarine waters.
Subpart 125.62(a)(l) of the 1982 regulations required the applicant's
diffuser to be located and designed to provide initial dilution, dispersion,
and transport sufficient to ensure compliance with water quality standards
at and beyond the ZID boundary under critical environmental and treatment
plant conditions. Because Subpart 125.62(a) was viewed to be a sufficient
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criterion; for ensuring that "significant amounts" of previously discharged
effluent are not entrained, this subpart was not modified In response to
UQA Section 303(e). [However, guidance Is provided herein on how to
position monitoring stations to determine compliance with this provision of
the WQA.] Subpart 125.59(b)(4) was modified to Include the prohibition of
Section 301(h) modified discharges Into stressed saline estuarlne waters,
and Subpart 125.62(f) was modified to apply only to stressed ocean waters.
WQA Section 303(f) applies only to POTWs that had existing agreements
(I.e., prior to 31 December 1982) to use outfalls of Section 301(h) POTWs.
This provision allows those POTWs to apply for their own Section 301(h)
modified permit within 30 days of enactment of the WQA. Because no POTW
applied under this provision, the Section 301(h) regulations were not
amended to reflect Section 303(f).
As stated 1n WQA Section 303(g), Sections 303(a), (c), (d), and (e) do
not apply to Section 301(h) modified permits that were tentatively or
finally approved prior to enactment of the WQA. However, Section 303(g)
further states that those sections will apply to all renewals of Section
301(h) modified permits that postdate enactment of the WQA. In response,
Subpart l25.59(e)(l)(111)(D) was added to the regulations, allowing certain
applicants to defer compliance with the specified section of the WQA until
permit renewal. [Applicants that had been Issued tentative denials, or that
had withdrawn their Section 301(h) applications prior to enactment of the
WQA may not take advantage of this "grandfathering" provision.] A require-
ment was also added to Subpart 125.59(e) stating that "grandfathered"
applicants and permittees must, within 90 days of the effective date of the
regulatory revisions, submit additional information regarding their intent
to demonstrate compliance with the new requirements under Parts 125.60
(primary or equivalent treatment requirements) and 125.65 (urban area
pretreatment requirements) upon permit renewal.
The statutory deadline for Section 301(h) applications was 29 December
1982. Neither the WQA nor the amended Section 301(h) regulations extend
that deadline. Hence, the aforementioned statute and changes to the
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regulations only apply to POTUs presently In the 301(n) program, POTVIs
presently 1n the program Include those that presently hold Section 301(h)
modified permits, and those awaiting a final decision from U.S. EPA.
PURPOSE AND SCOPE
The primary purpose of this document Is to provide technical support
for Implementing the Section 301(h) regulations that were amended In
response to WQA Section 303. It does so in the following ways:
• Explaining WQA Sections 303(a) through 303(g), and resulting
changes 1n the Section 301(h) regulations (provided above, 1n
the section entitled "Background," and below, 1n the section
entitled "Statutory Criteria and Regulatory Requirements")
• Providing technical guidance for Implementing the new
regulations, and updating that guidance for existing
regulations (provided below, in the chapter entitled
"Demonstrations of Compliance by Permittees")
• Providing guidance on the preparation of applications for
relssuance of Section 301(h) modified NPDES permits (provided
below, In the chapter entitled "Demonstrations of Compliance
by Permittees"), on the evaluation of those applications to
determine compliance with the regulations, and on the
Issuance and relssuance of Section 301(h) modified permits
(provided below, in the chapters entitled "Evaluations of
Compliance by U.S. EPA" and "Relssuance or Termination of
Section 301(h) Modified Permits," respectively).
This document provides the following new technical guidance on how the
results of studies and monitoring can be used to demonstrate compliance with
the new regulations:
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• Guidance for assessing Impacts of the applicant's modified
•' discharge "alone or in combination with pollutants from other
'• •" sources"
• Guidance on methods for demonstrating compliance with urban
area pretreatment requirements
• ; Guidance on demonstrating compliance with applicable water
quality standards and criteria
• Guidance for demonstrating that dilution water does not
contain significant amounts of previously discharged effluent.
This guidance appears In the section entitled "Appropriate Analyses and
Presentation of Results" below, and 1n some cases, the appendices. Updated
guidance 1s also provided on the calculation of Initial dilution, navigation
and station positioning methods, analysis of water quality data, assessments
of the long-term effects of 301(h) discharges, sedimentation and dispersion
models, calculations of Initial mixing relative to conditions at the ZID
boundary, and the degree of recirculatlon in the presence of contaminated
receiving waters.
Monitoring data collected during the term of the modified NPDES permit
are submitted to the regional jurisdiction of the U.S. EPA (hereinafter
referred to as Regions) 1n accordance with permit procedures. The Regions
use these data to determine continuing compliance with the terms and
conditions of the permit, and with Section 301(h) regulations. Although
this document was not written to help the Regions evaluate monitoring data
during the terms of the modified permits, much of the guidance provided
below Is applicable to such evaluations.
NPOES permits are Issued for 5-yr periods. At least 180 days prior to
expiration, POTWs holding Section 301(h) modified permits must apply for
reissuance of their NPDES permits. At the same time, they may apply for
relssuance of their Section 301(h) modification, as stipulated in Parts
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125.59, 122.21(d), and 124.3. Because the deadline for original applications
for Section 301 (h) modified permits has expired, only applications upon which
there has not yet been a decision and applications for re Issuance will be
considered by the U.S. EPA In the future.
According to Subpart 125.59(c), "applicants for permit renewal shall
support continuation of the modification by supplying to EPA, upon request,
the. results of studies and monitoring performed during the life of the
permit." However, neither this subpart nor other subparts of Part 125,
Subpart G [Criteria for Modifying the Secondary Treatment Requirements
under. Section 301(h) of the Clean Water Act] provide specific guidance on
how the results of studies and monitoring should be used to support the
application for permit reissuance.
In the 1982 Section 301(h) regulations, U.S. EPA recognized the limited
financial resources of most small applicants and the lower potential for
environmental Impacts typically associated with small discharges. Those
regulations provided separate questionnaires for large and small applicants,
with fewer requirements placed on small applicants. To avoid the excessive
duplication that existed with the separate questionnaires, the amended
Section 301(h) regulations, and hence this document, present a single
questionnaire. In this document, each question in the combined questionnaire
is followed by a statement as to who must respond (i.e., large dischargers,
small dischargers, or both), and guidance on how to respond.
As was true under the 1982 regulations, the level of detail expected of
small applicants in their responses is considerably less than that required
of large applicants for the same question. Because the amended Section
301(h) regulations do not provide specific guidance on the required level of
detail, the Regions have considerable discretion regarding the level of
detail necessary for applicants to demonstrate continued compliance with the
301(h) regulations. This document addresses the levels of detail that the
Regions may require of small and large applicants during the permit
reissuance process.
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This document provides the Regions with procedures for evaluating
compliance with Section 301(h) regulations. Appropriate uses of monitoring
data to evaluate compliance with regulatory criteria are discussed,
Including the use of monitoring data to evaluate predictions of conditions
that were expected to occur during the term of the Section 301(h) modified
permit. Guidance Is also provided to the Regions on how to evaluate the
presence or absence of environmental Impacts, and whether those Impacts
comply .with 301(h) criteria.
Having reached a decision regarding an application for relssuance of a
Section 301(h) modified permit, the Region may reissue the Section 301(h)
modified permit with the same or different permit conditions, or deny the
Section 301(h) modification. In the case of denial, the NPDES permit would
then be reissued by the U.S. EPA (or, in NPOES-delegated states, by the
state) with secondary treatment requirements. This document defines the
conditions under which each of these actions Is appropriate, and provides
the Region with guidance on procedures for reissuing and terminating Section
301(h) modified permits. It does not provide guidance on the preparation of
NPDES permits, which has been published elsewhere (U.S. EPA 1986b).
STATUTORY CRITERIA AND REGULATORY REQUIREMENTS
The WQA of 1987 amended CWA Section 301(h) in eight respects. Each of
these 1s summarized below, followed by references to key subsections of the
301(h) regulations that respond to the statutory criteria of the CWA.
1) Section 301(h) modified discharges are prohibited from
Interfering, alone or in combination with pollutants from
other sources, with the attainment or maintenance of water
quality which assures the protection and uses listed in
Subsection 301(h)(2). (emphasis added) [125.62(f)]
2) The scope of monitoring Investigations 1s limited to only
those Investigations necessary to study the effects of the
modified discharge. [125.63(a)]
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3) With respect to any toxic pollutant Introduced by an
Industrial source and for which there Is no applicable
pretreatment requirement 1n effect, POTWs serving populations
of 50,000 or more are required to demonstrate that sources
Introducing waste Into the POTVf are 1n compliance with all
applicable pretreatment requirements, that the POTVf will
enforce those requirements, and that the POTU has 1n effect a
pretreatment program which, In combination with the POTU's own
treatment processes,, removes the same amount of toxic
pollutant as would be removed If the POTU were to apply
secondary treatment and had no pretreatment program for that
pollutant. [125.65, 125.58(g), 125.58(j), 125.58(q),
125.58(w), 125.58(b)]
4) At the time the Section 301(h) modified permit becomes
effective, the POTU must be discharging effluent that has
received at least primary or equivalent treatment [as
defined 1n Subpart 125.58(r)], and that meets the water
quality criteria established under 304(a)(l) of the UQA after
Initial mixing in the receiving waters. [125.60, 125.58(r),
125.62(a)]
5) Section 301(h) modified permits may not be issued for
discharges Into waters that contain significant amounts of
previously discharged effluent from the POTU. [Regulations
not amended.]
6) Section 301(h) modified permits may not be issued for
discharges Into saline estuarlne waters that exhibit stressed
conditions, regardless of the applicant's contribution to
those stressed conditions. Section 301(h) modified permits
may not be Issued for discharges into the Mew York Bight Apex
under any conditions. [125.59(b)(4), 125.62(f)j
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7) Any POTU that had an agreement before 31 December 1982 to use
an outfall operated by another POTU that had applied for or
received a Section 301(h) modified permit could have applied
for Its own Section 301(h) modified permit within 30 days of
enactment of the WQA. [Regulations not amended.]
8) Some provisions of the WQA do not apply to applications that
received tentative or final approval before enactment of the
WQA, but apply to all applications for renewal of Section
301(h) modified permits. [125.59(e)]
Among the eight major changes listed above, numbers 1, 3, 4, 5, and 8
are most Important to applicants and permittees that are not prohibited from
applying for a Section 301(h) modified permit under other provisions of the
amended regulations. The first major change requires POTUs to consider the
Impacts of their discharge on the receiving environment and biota In combi-
nation with pollutants from other sources. Previously, POTWs were required
only to consider whether their discharge contributed to such Impacts.
Change number 3 requires applicants to Implement an urban pretreatment
program (discussed In detail below under "Demonstrations of Compliance by
Permittees" and In Appendix E). This new statutory requirement complements
the toxics control program requirements In Part 125.66, and applies In
addition to any applicable pretreatment requirements contained In Subpart
403. Dischargers may demonstrate compliance with Part 125.65 by demon-
strating that an applicable pretreatment requirement 1s In effect, or by
demonstrating secondary equivalency.
Applicable pretreatment requirements may be In the form of categorical
pretreatment standards promulgated by the U.S. EPA under CWA Section 307,
local limits developed in accordance with Subsection 403, or a combination
of both. It 1s anticipated that most dischargers will be required to use a
combination of both approaches to satisfy Part 125.65 with respect to all
toxic substances introduced Into the treatment works by industrial sources.
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Alternatively, dischargers nay demonstrate that Us own treatment
processes, In combination with pretreatment by Industrial dischargers,
achieves "secondary removal equivalency." Dischargers are required to make
this demonstration whenever they cannot show that a toxic pollutant
Introduced by an Industrial discharger 1s subject to an "applicable
pretreatment requirement." Although secondary treatment 1s Intended to
control conventional, nontoxlc pollutants, a certain amount of each toxic
pollutant 1n the Influent Is removed during the process. The Intent of this
part of WQA Section 303(c) 1s to ensure that a Section 301(h) discharger
removes that same amount of a toxic substance through Industrial pretreatment
plus the applicant's own treatment at less-than-secondary levels, as would
be removed if the applicant were to apply secondary treatment and no
pretreatment requirements existed for that pollutant. This demonstration
requires the use of a secondary treatment pilot plant to determine empir-
ically the amount of a toxic pollutant the would be removed from the
Influent If the applicant were to apply secondary treatment. For each
pollutant Introduced by an industrial source, that applicant would then
demonstrate that Industrial pretreatment plus the POTW's own treatment
processes removed the same amount of pollutant as was removed by the
secondary treatment pilot plant.
Change number 4 requires all Section 301(h) dischargers to achieve a
minimum of primary or equivalent treatment, thereby establishing a primary
treatment floor for all marine and estuarine POTWs. It also requires all
Section 301(h) dischargers to meet the water quality criteria established
under WQA Subsection 304(a)(l) after Initial nixing in the receiving waters.
Section 301(h) dischargers have always been required to meet state water
quality standards that are appropriate to local conditions, and that have
been approved by the U.S. EPA. For this reason, Section 301 (h) dischargers
are required first to demonstrate compliance with water quality standards,
and then to demonstrate compliance with water quality criteria only for
those pollutants for which no directly corresponding numerical water quality
standard exists. For example, if a water quality standard exists only for a
group of toxic substances, such as metals, applicants would also be required
to demonstrate compliance with the water quality criteria for individual
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metals (e.g., cadmium, lead, zinc) to demonstrate compliance with
Part 125.60.
The Section 301(h) regulations were not amended with respect to the
change number 5, redrculatlon and re-entra1nment of previously discharged
effluent from the POTH. However, POTUs that discharge Into receiving
environments where re-entra1nment is likely must consider the possible
effects of such entrapment when demonstrating compliance with applicable
water quality standards, water quality criteria, and other Section 301(h)
criteria. Re-entra1nment Is most often of concern In bays and estuaries
where tidal currents predominate, and previously discharged effluent Is
likely to be advected Into the ZID after the tidal currents reverse.
Technical guidance Is provided herein to assist applicants with demonstrating
compliance with this new requirement.
Finally, the change number 8 1n the regulations "grandfathers"
applicants that had received tentative or final approval of their Section
301(h) modified permits before passage of the WQA. Such applicants are
"grandfathered" for changes 1, 3, 4, and 5 above, but only for the term of
the existing Section 301(h) modified permit. Applicants for reissuance of
Section 301(h) modified permits must demonstrate compliance with all
applicable Section 301(h) criteria to qualify for renewal of the Section
301(h) modified permit. Moreover, under Subpart 125.59(e), applicants for
new or reissued Section 301(h) modifications (Including grandfathered
applicants) must, within 90 days of the effective date of the amended Section
301(h) regulations, submit to the Administrator additional information
regarding their Intent to demonstrate compliance with Part 125.60 (I.e.,
primary treatment floor, compliance with water quality criteria) and Part
125.65 (I.e., urban area pretreatment requirements). Such applicants will
then have 2 yr to demonstrate compliance with Parts 125.60 and 125.65, or
in the case of some grandfathered applicants, until the time of application
for permit renewal if that time is more.than 2 yr away.
Each of these eight major statutory changes has been Integrated Into
the amended Section 301(h) regulations, and must be satisfied by applicants
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for relssuance of Section 301(h) permits. Regulations applicable to such
applications Include NPDES permit regulations (Part 122) and the amended
Section 301(h) regulations (Part 125, Subpart G). These regulations,
Including the changes that resulted from the HQA are discussed below in
detail.
Part 122. U.S. EPA Administered Programs; The national Pollutant Discharge
Elimination System
Subpart 122.21 (d). Duty to Apply-
Under the subpart, POTWs with an exiting NPDES permit must submit an
application for a new NPDES permit a minimum of 180 days before the existing
permit expires. The applicant may ask to submit the new application after
this due date, and the Region may grant such a request. The Region may
extend the due date up to the expiration date of the existing permit. Upon
review of an application, the Region may determine that additional Informa-
tion 1s needed to determine compliance with 301(h) regulations and permit
conditions. Such Information may be requested at anytime (Including after
the application deadline has passed) in accordance with Subpart 122.41(h).
It 1s strongly recommended that POTWs submit their applications for
relssuance of Section 301(h) modified permits as early as possible, and no
later than 180 days prior to expiration of the existing permit. This early
submittal 1s particularly Important because of the need to establish
compliance with the recent statutory amendments to Section 301(h). As
discussed below, early submittal gives the Regions time to review applica-
tions for completeness, and to request any Information needed to complete
applications before existing permits expire. An applicant must submit a
completed application containing all required information prior to expiration
of the existing permit, or at the time the application 1s due, whichever is
first. Timely submittal of a completed application is required to qualify
for the continuation described below.
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Part 122.6 Continuation of Expiring Permits--
A permittee may have submitted a complete, timely application to the
Region, but through no fault of the permittee, the Region may not have
Issued a new permit with an effective date on or before the expiration of
the previous permit. This section provides that 1n those cases, the
previous permit will remain fully effective and enforceable, pursuant to the
Administrative Procedures Act.
Part 125. Suboart G
Part 125.56. Scope and Purpose--
Part 125, Subpart 6 establishes the criteria by which the U.S. EPA
evaluates requests for Section 301(h) modified permits. It also establishes
special permit conditions that must be Included In Section 301(h) modified
permits.
Part 125.57. Law Governing Issuance of Section 301(h) Modified Permit--
All applicants for Section 301(h) modified permits must demonstrate
satisfactorily to the U.S. EPA that nine requirements will be met by the
modified discharge:
1. An applicant must demonstrate that an applicable water quality
standard exists for each pollutant for which the modification
is requested. Details of this requirement are given In Part
125.61. Demonstrations that applicable water quality
standards exist will be superfluous for reissuance of Section
301(h) modified permits because the original Section 301(h)
modified permit was based, in part, on successful demon-
strations that such standards exist. However, as specified in
Part 125.61, an applicant must demonstrate that the modified
discharge will comply with applicable water quality standards.
An applicant must also provide a determination signed by an
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authorized state or Interstate agency, stating that the
modified discharge Mill comply with state law. Both the
demonstration of compliance with applicable water quality
standards and the state's determination are required of
applicants for relssuance of Section 301 (h) modified permits.
2. An applicant must demonstrate that the modified discharge,
alone or In combination with pollutants from other sources,
will not Interfere with the attainment or maintenance of
water quality that assures the protection of public water
supplies; assures the protection and propagation of a
balanced Indigenous population of fish, shellfish, and
wildlife; and allows for recreational activities. Specific
demonstrations that must be performed by an applicant are
stated in Part 125.62. All are required of applicants for
relssuance of Section 301 (h) modified permits.
3. An applicant must demonstrate that a monitoring program has
been established, and that this monitoring program Is capable
of documenting the Impact of the modified discharge on a
representative sample of aquatic biota. The scope of that
monitoring program should only include those investigations
necessary to study the effects of the modified discharge.
General requirements of monitoring program design and spe-
cific requirements of the biological, water quality, and ef-
fluent monitoring components are specified in Part 125.63.
Demonstrating that an effective monitoring program has been
established will be simple for most POTWs that apply for
relssuance of Section 301(h) modified permits because
monitoring data will have been collected over the life of the
existing permit. However, the U.S. EPA may require an
applicant to demonstrate the effectiveness of an established
monitoring program when the quality of the data is suspect,
or when Incomplete data have been submitted to the U.S. EPA.
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4. An applicant must demonstrate that the modified discharge
will not result 1n additional requirements on other point or
nonpolnt sources of pollutants. Part 125.64 requires an
applicant to provide a determination signed by an authorized
. state or Interstate agency Indicating whether the modified
discharge will result 1n any such additional requirements.
The foregoing demonstration and determination of compliance
are required of applicants for relssuance of Section 301(h)
modified permits.
5. An applicant must demonstrate that pretreatment requirements
for sources that Introduce wastes Into the treatment works
will be enforced. This demonstration Includes chemical
analyses of the discharge for all toxic pollutants and
pesticides; Identification of sources of toxic pollutants and
pesticides; and development of, Implementation of, and
compliance with an approved Industrial pretreatment program,
as specified 1n Part 125.65. However, these requirements
are waived for small applicants that certify that there are
no known or suspected sources of toxic pollutants and
pesticides, and who document the certification with an
Industrial user survey as described by Subsection 403.8(f).
Because they receive Influent only from municipal sources,
most small applicants for reissuance of Section 301(h)
modified permits will be required to provide only an updated
certification that there are no known or suspected sources of
toxic pollutants or pesticides. Because Industrial sources
of pollutants may have changed over the term of the original
Section 301(h) modified permit, both large and small
applicants should review updated information on industrial
sources of pollutants before performing the required
demonstration or certifying that there are no known industrial
sources of toxic pollutants or pesticides.
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6. An applicant with treatment works serving a population .of
50,000 or more must demonstrate that at the time of final
permit approval, applicable pretreatraent requirements will be
1n effect for each toxic pollutant introduced Into the
treatment works from Industrial users. Applicable pretreat-
ment requirements are defined 1n detail In Subpart 125.65.
In Part 125.65, It 1s further stated that applicants may
alternatively meet the requirements of this section with
respect to a particular toxic pollutant pretreatment program
1n effect [125.65(c)]» or by having 1n effect a program that
achieves secondary removal equivalency for that pollutant
[125.65(d)].
7. An applicant must demonstrate that a schedule of activities
has been established to eliminate the Introduction of toxic
substances from nonlndustrlal sources Into the treatment
works. Just as was required In the original Section 301(h)
application, applicants must comply with the specific
requirements of Part 125.65(d). These requirements are that
a public education program be developed, submitted with the
application, and Implemented; that nonindustrial source
control programs be developed and implemented in accordance
with schedules submitted with the application; and that the
foregoing program may be revised by the U.S. EPA before
Issuance or reissuance of a Section 301(h) modified permit,
or during the term of that permit. However, for small
applicants certifying that there are no known or suspected
problems related to toxic pollutants or pesticides in the
discharge, only a public education program 1s required. As
was true for original Section 301(h) applications, most small
applicants should be able to provide the foregoing certi-
fication. However, updated information on water quality,
sediment quality, and biological conditions should be
reviewed by the small applicant before certifying that there
are no known or suspected water quality, sediment
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accumulation, or biological problems that are related to the
discharge of toxic pollutants or pesticides.
8. An applicant roust demonstrate that the modified discharge
will not result 1n new or substantially Increased discharges
of the pollutant for which a Section 301(h) modification 1s
being requested above the discharge specified 1n the Section
301(h) modified permit. Details of this requirement are
given 1n Part 125.67, which states that where pollutant
discharges are attributable, 1n part, to combined sewer
overflows, an applicant must minimize such overflows and
prevent Increased discharges of pollutants. An applicant
must also project effluent volumes and mass emission rates
for pollutants to which the modification applies. These
projections must be provided 1n 5-yr Increments for the
design life of the facility. This demonstration applies to
applicants for relssuance of Section 301(h) modified permits.
9. An applicant must demonstrate that the modified discharge will
have received at least primary or equivalent treatment, as
required under Part 125.60. An applicant must also meet the
criteria established under CWA Subsection 304(a)(l) in
accordance with Subpart 125.62(a). Section 301(h) defines
primary or equivalent treatment. It also prohibits Section
301(h) modified discharges into waters that contain "sig-
nificant amounts of previously discharged effluent from such
treatment works," and Into saline estuarine waters that at
the time of application do not support a balanced Indigenous
population of shellfish, fish and wildlife, or allow recre-
ation in or on the waters, or which exhibit ambient water
quality that does not meet specified standards. EPA has de-
termined that a "significant.amount of previously discharge
effluent" is that amount which would cause the discharge plume
to violate water quality beyond the zone of Initial dilution.
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Part 125.58. Definitions—
This section defines terms applicable to Subpart G regulations.
Definitions of primary or equivalent treatment, pretreatment, categorical
pretreatment standard, secondary removal equivalency, water quality
criteria, permittee, and New York Bight Apex have been added to the amended
Section 301(h) regulations, and definitions of Industrial source, ocean
waters, applications, and application questionnaire have been changed.
Part 125.59. General -
This section establishes general criteria and requirements that must be
met by applicants for Section 301(h) modified permits. Also specified are
several regulatory options that may be exercised by U.S. EPA during the
application process. As Indicated below, some of the general regulations
are not relevant to applications for relssuance of Section 301(h) modified
permits.
According to Subpart 125.59(a), an application may be based on a
current, Improved, or altered discharge Into ocean waters or saline
estuarine waters. This requirement remains relevant to applications for
reissuance of Section 301(h) modified permits.
No Section 301(h) modified permits may be issued for the following
discharges [see Part 125.59(b)]:
• Discharges that would not assure compliance with Part 122 and
Part 125, Subpart G
• Discharges of sewage sludge
• Discharges that would not be 1n compliance with state, local,
or other federal laws and Executive Orders [Subpart 125.59(b)]
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• Applicants that have not met at least primary or equivalent
treatment requirements (Part 125.60)
• Discharges entering saline estuarlne waters that are stressed
1n the manner set forth In Subpart 125.59(b)(4)
• Discharges that enter the New York Bight.
This requirement Is relevant to applications for relssuance of Section
301(h) modified permits.
Subpart 125.59(c) specifies that all applications for Section 301(h)
modified permits must contain a signed, completed NPDES application; a com-
pleted Application Questionnaire; and a certification of veracity. This
provision remains valid for applications for relssuance of Section 301(h)
modified permits. Applicants for permit renewal should support continuation
of their modification with results of studies and monitoring performed
during the life of the permit. As was the case for original Section 301 (h)
applications, the level of detail required of applicants responding to
questions in the Application Questionnaire will vary according to the
volume, composition, and characteristics of the discharge, and to the
characteristics of the receiving environment and biota. Applicants should
consult with the EPA Region for permit relssuance well in advance of the
application deadline. Timely consultation will ensure that each applicant
is informed of the appropriate level of detail required to complete the
Application Questionnaire, and will ensure that all data necessary for
completing the questionnaire have been collected and are adequate to
demonstrate compliance with 301(h) criteria and regulations.
Revisions to original Section 301(h) applications that were submitted
under the 1979 and 1982 application deadlines are discussed 1n Subpart
125.59(d). Such revisions are not relevant to applications for reissuance
of Section 301(h) modified permits. As noted above, a discharger holding an
existing Section 301(h) modified permit must submit an application for a new
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Section 301(h) modified permit at least 180 days before the existing permit
expires.
Deadlines for subnrittal of applications for relssuance of Section
301(h) modified permits are specified 1n Subpart 122.21(d) and are discussed
above. The distribution of such applications 1s not specified In Part 124 or
Part 125, Subpart G. However, applicants should adhere to the distribution
schedule required for original Section 301(h) applications, as Indicated 1n
Subpart 125.59(f)(l): one original and one copy to the appropriate U.S.
EPA Regional Administrator, and one copy to state and Interstate agencies
authorized to provide certification or concurrence 1n accordance with Parts
124.53-124.55. Deadlines for applicants desiring to submit revised
applications following the Issuance of a tentative decision are stated In
Subpart 125.59(f)(2).
Under Subpart 125.59(e), applicants or permittees are required to
submit additional Information regarding their Intent to demonstrate
compliance with Part 125.60 (Primary or Equivalent Treatment) and Part 125.65
(Urban Area Pretreatment Program) within 90 days of the effective date of
the regulations. Subpart 125.59(e) specifies the additional Information
required, and the conditions under which the submittal of this Information
may be delayed until the time of permit renewal. Deadlines for providing
additional Information to demonstrate compliance with Parts 125.60 and
125.65 are specified in Subpart 125.59(f)(3).
A favorable state determination 1s required before the Region reviews
an application. Under Subpart 125.59(f)(4), state determinations are due
to the regions no more than 90 days after an application 1s submitted to the
U.S. EPA. The Regions may extend this 90-day deadline upon request by the
state. However, extensions are not recommended because they decrease the
amount of time remaining until expiration of the existing modified permit,
and the amount of time available for an applicant to respond to concerns of
the state. It is strongly recommended that the applicant ensure that it
obtains a timely determination from the state to submit to the Region, so as
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not to diminish an applicant's likelihood of being reissued a Section 301(h)
modified permit.
Under Subpart 125.59(g), the Regions may authorize or request an
applicant or permittee to submit additional data after the application
deadline. Such Information must be submitted within 1 yr of the date of the
authorization or request.
Options that the Regions and states may exercise In granting or denying
a Section 301(h) modified permit are specified 1n Subpart 125.59(1). All
remain relevant to applications for reIssuance of Section 301(h) modified
permits. For the Administrator to grant a Section 301(h) modified permit, an
applicant must have demonstrated compliance with Parts 125.59-125.68.
State certification (concurrence) Is also required, with the state director
coslgnlng the Section 301(h) modified permit If an intent to do so was
indicated in the written concurrence. Section 301(h) modified permits must
be Issued in accordance with procedures in Part 124, and must contain all
applicable terms and conditions specified in Parts 122 and 125.69. Appeals
of Section 301(h) determinations may be made in accordance with procedures
in Part 124. Under Subpart 125.59(h), the Administrator may grant a
tentative decision on a Section 301(h) modified permit if the applicant can
demonstrate that the modified discharge will comply with the provisions of
Subpart 125 based on a schedule submitted by the applicant.
Part 125.68. Special Conditions for Section 301(h) Modified Permits--
Part 125.68 sets forth special conditions that must be Included in
Section 301(h) modified permits, in addition to those specified 1n Part 122.
All remain valid for reissued Section 301(h) modified permits. The special
conditions are as follows:
• That effluent limitations and.mass loadings assure compliance
with 301(h) regulations
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That schedules of compliance be Included for the required
Industrial pretreatment program [Subpart 125.66(c)], the
nonIndustrial toxics control program [Subpart 125.66(d)],
and control of combined sewer overflows [Part 125.67]
That the proposed monitoring program Include provisions for
monitoring biota [Subpart 125.63(b)], water quality [Subpart
125.63(c)], and effluent [Subparts 125.60(b) and 125.63(d)]
That the monitoring data be reported at the frequency
prescribed In the approved monitoring program.
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DEMONSTRATIONS OF COMPLIANCE BY PERMITTEES
The recently promulgated amendments to Part 125, Subpart G have been
Integrated Into the Section 301(h) application questionnaire, which must be
completed and Included with all applications for renewal of Section 301(h)
modified permits. Explanations of the demonstrations to be made by
applicants are given below following each question, and 1n the appendices to
this document, as appropriate.
All applicants for new or reissued Section 301(h) modified permits are
required to demonstrate compliance with the new regulatory criteria.
However, Part 125.59 establishes special procedures and deadlines for
demonstrating compliance with Part 125.60 (I.e., primary treatment floor)
and 126.65 (I.e., urban area pretreatment requirements). Compliance with
Subpart 125.62(a)(l) (i.e., water quality criteria) is not included in the
special procedures and deadlines established under Part 125.59.
Under Subpart 125.59(e), applicants for new or reissued Section 301(h)
modified permits must submit a letter of intent to demonstrate compliance
with Parts 125.60 and 125.65. For compliance with Part 125.60, the letter of
intent must include a description of the proposed treatment system and a
project plan for achieving compliance (including a schedule for data
collection; dates for design and construction of necessary facilities;
submittal of influent, effluent, and receiving water quality data; and any
other information necessary for determining compliance with Part 125.60).
For compliance with Part 126.65, the letter of Intent must Include a
description of the approach that will be used to achieve compliance and a
project plan for achieving compliance (including necessary data collection
activities, submittal of additional information, and the development of any
appropriate pretreatment limits). Applicants that submit additional
information must modify their NPDES form and Application Questionnaire as
needed to ensure that the information in their application is complete and
27
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correct, must obtain new state determinations as specified 1n Subparts
125.61(b)(2) and 125.64(b), and must provide the certification required
under Subpart 122.22(d).
Subpart 125.59(f) requires permittees and applicants with tentative or
final approval of Section 301(h) modifications to submit a letter of Intent
that contains the Information required under Subpart 125.59(e)(l). This
letter must be submitted within 90 days of the promulgation of the amended
Section 301(h) regulations. Applicants that have not yet received tentative
approval of a Section 301(h) modification must submit a letter of Intent
within 90 days of receipt of that tentative approval. Applicants that are
not "grandfathered" under Subpart 125.59(e)(l)(1ii)(D) must demonstrate
compliance with Parts 125.60 and 125.65 within 2 years of the promulgation
of the amended Section 301(h) regulations. Applicants grandfathered under
the aforementioned subsection must demonstrate compliance with these
subsections at the time of permit renewal or within 2 years of the promulga-
tion of the amended Section 301(h) regulations, whichever is later.
APPLICATION FORMAT
As specified In Subpart 125.59(c), a full, completed application for a
Section 301(h) modified permit contains a certification of veracity; a
signed, completed NPDES application [Short Form A or Standard Form A in
accordance with Subparts 122.21(d) and 124.3]; and a completed Application
Questionnaire. The order in which these parts are assembled Is not
specified in the 301(h) regulations, but many applicants for original
Section 301(h) modified permits used the following sequence: '
• Cover letter to U.S. EPA with the certification of the
application's veracity either Included In, or attached to,
the letter [many large applicants Included the cover letter
and certification of veracity in the introduction to the
Application Questionnaire (i.e., Part I)]
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• The signed, completed NPDES application, establishing the
requested permit conditions (e.g., effluent limitations)
• The completed Application Questionnaire.
.>
Although the foregoing sequence of application parts 1s not mandatory, it 1s
recommended because It facilitates review by the Region and appropriate
state agencies. Accessory documents that would be useful to the Region
during review of the application (e.g., data reports) should be appended to
the application.
The Application Questionnaire given as Appendix A of Part 125, Sub-
part G 1s designed to provide the U.S. EPA with all Information necessary
to determine whether an applicant meets the statutory criteria and regula-
tions of Subpart G. Guidance provided 1n this document and 1n Design of
301 (h) Horn taring Programs for Municipal Hastewater Discharges to Marine
Haters (Tetra Tech 1982a) complements the questionnaire. Although applicants
are required to respond to applicable questions, the Regions may determine
the appropriate level of response to each question for each applicant. The
Region may also allow an applicant to Incorporate data by reference to
previous submlttals.
The appropriate levels of response to questions should be communicated
by the Regions to each applicant through timely consultation, which will
help permittees submit the appropriate Information on time. Because of the
substantial differences among permittees and their respective receiving
environments, applicants' responses to a given question are expected to
range from a single sentence to a very detailed analysis. Close working
relationships, particularly during the end of the existing permit term,
will ensure that all data necessary for completion of the Application
Questionnaire are available well in advance of the application deadline, and
that each applicant understands the level of detail appropriate for each
response. Such discussions should result in more concise responses to the
questions, and should help avoid unnecessary effort and expense by the
applicant during the application process.
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REQUIRED DATA
Applicants "shall support continuation of the modification by supplying
to EPA, upon request, the results of studies and monitoring performed during
the life of the permit" [Subpart 125.59(c)]. For many dischargers, data
collected during these studies and monitoring programs will be relevant to
many, or all, of the questions In the Application Questionnaires. Additional
relevant data may be found In publications and technical reports produced by
other agencies, Institutions, and companies working 1n nearby areas of the
receiving environment. Data from such surveys could be used to better
define environmental factors, such as the critical density profile for
Initial dilution calculations or biological conditions in a reference area.
However, for some applicants, no new data [I.e., data collected after
Issuance of the original Section 301(h) modified permit] will be available
to respond to some of the questions in the Application Questionnaire.
Although it 1s the permittee's responsibility to submit the appropriate
Information, it is critical that the Regions work with permittees, and
communicate to them any perceived information deficiencies well in advance of
the application deadline. Once informed of information deficiencies,
permittees must collect, analyze, and interpret the necessary information for
incorporation Into the application for permit reissuance. Failure to supply
necessary information could result in permit denial, based on the grounds
that a complete application was not submitted. After an application has
been received, however, the Region may determine that additional Information
1s needed to determine compliance with 301(h) regulations and permit
conditions. Such information may be requested at any time (including after
the application deadline has passed) in accordance with Subparts 125.59(f)
and 122.41(h).
APPROPRIATE ANALYSES AND PRESENTATION OF RESULTS
Guidance is provided below for the preparation of complete applications
for Section 301(h) modified permits. Special instructions and exceptions for
30
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small applicants are also provided. The sequence below corresponds .to that
recommended In the preceding discussion of application format. Accessory
documents (e.g., data reports) should be appended to the application.
Just as original Section 301(h) applications were based on the most
recent, appropriate, and technically correct data available at the time the
application was prepared, applications for renewed Section 301(h) modified
permits should consider monitoring data collected over the term of the
existing modified permit, as required under Subpart 125.59(c)(4). When
monitoring data and other Information collected over the term of the
existing permit confirm that all values of the variables used In a given
calculation or demonstration have not changed and are not expected to change
over the term of the new modified permit, the applicant may simply reproduce
the calculation or demonstration that was given in the original application.
However, in cases where the values of one or more variables have changed, or
where new monitoring data are useful for supporting a given demonstration,
those data should be Included in the required response. All demonstrations
of compliance with applicable statutes and regulations must consider the
effects of the discharge singly and in combination with pollutants from other
sources, if any other sources exist [301(h)(2) and Subparts 125.57(a)(2) and
125.62(f)].
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I. INTRODUCTION
•* ' .
For clarity and consistency, 1t Is recommended that the application be
assembled, in the following sequence:
• A cover letter signed by the responsible official for the POTW
• .The statement of veracity mandated in Subpart 125.59(c)(3),
also signed by the responsible official for the POTVI
• A table of contents for the application, Including any
appendices
• A 11st of figures for the application
• A 11st of tables for the application
• A signed, completed NPOES Application Short Form A or
Standard Form A
• A completed Application Questionnaire
• Any accessory documents (e.g., technical reports) considered
necessary for an Independent review of the application.
Guidance for preparing a complete application for reissuance of a
Section 301(h) modified permit 1s provided below. The sequence in which the
application parts are discussed corresponds to that recommended above.
Just as original Section 301(h) applications were based on the most
recent, appropriate, and technically correct data available at the time the
application was prepared, applications for reissuance of Section 301(h)
modified permits should consider monitoring data collected over the term of
the existing modified permit as required under Subpart 125.59(c}(4). When
monitoring data and other information collected over the term of the
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existing permit confirm that all values of the variables used In a given
calculation or demonstration have not changed and are not expected to change
over the term of the new modified permit, the applicant may simply reproduce
the calculation or demonstration that was given In the original application.
However, 1n cases where the values of one or more variables have changed, or
where new monitoring data are useful for supporting a given demonstration,
those data should be Included 1n the required response.
Under 301(h)(2) and Subparts 125.57(a)(2) and 125.62(f), all demonstra-
tions of compliance with applicable statutes and regulations must consider
the effects of the discharge singly and In combination with pollutants from
other sources, if any other sources exist. When demonstrating such
compliance, the level of detail required of small applicants Is considerably
less than that required of large applicants for the same demonstration.
Applicants should consult with U.S. EPA personnel before submitting an
application to determine the level of detail that 1s appropriate for their
discharge. POTUs that have been classified as small dischargers, but that
no longer meet the conditions of the definition of small discharger [Subpart
125.58(c)] or that are not expected to meet those conditions during the next
permit term, must apply for reissuance of this Section 301(h) modified
permit as a large discharger.
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JJ. GEHERAL INFORMATION AND BASIC DATA REOUIREHENTS
II.A. Treatment System Description
II.A.I. Are you applying for a modification based on a current
discharge, Improved discharge, or altered discharge as defined in
Part 125.58? [Subpart 125.59(a)J
*** Large and small dischargers must respond.
Applicants should consider "current discharge" to mean the actual
volume, composition, and location of a 301(h) permittee's discharge at the
time of permit reappHcation. Use of the latest 12 no of data would be most
appropriate 1n the application.
An "Improved discharge" may result from any of the following changes:
• Improvements to the collection system, treatment plant, or
outfall (Including outfall relocations)
• Improvements to treatment levels or discharge characteristics
• Improvements in the operation or maintenance of the treatment
system
• Measures to control the Introduction of pollutants into the
treatment works.
For improved discharges, applicants should briefly describe the changes to
the treatment system or Us operation upon which the application is based.
Discharge alterations include all changes that result in a treatment
level less than that currently achieved, including changes in effluent volume
or composition. All changes that result in the downgrading of effluent
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characteristics, regardless of whether the outfall was previously -Improved
or relocated to compensate for lower effluent quality, are considered
altered discharges. Applications for altered discharges are permissible
only for downgrading of effluent characteristics that are attributable
entirely to population growth and/or Industrial growth within the service
area. Applicants who propose altered discharges based on population growth
and/or Industrial growth, and who propose Improvements in treatments levels,
should briefly describe the changes to the treatment system or Its operation
upon which the application 1s based..
II.A.2. Description of the Treatment/Outfall System [Subparts
125.62(a) and 125.62(e)]
a. Provide detailed descriptions and diagrams of the
treatment system and outfall configuration which you
propose to satisfy the requirements of Section 301(h)
and Part 125 Subpart G. Hhat is the total discharge
design flow upon which this application is based?
b. Provide a map showing the geographic location of the
proposed outfall(s) (i.e., discharge). What is the
latitude and longitude of the proposed outfall(s)?
c. For a modification based on an improved or altered
discharge, provide a description and diagram of your
current treatment system and outfall configuration.
Include the current outfall's latitude and longitude, if
different from the proposed outfall.
*** Large and small dischargers must respond.
Most of the above Information can be found In Sections 1-13 of the
NPDES Standard Form A. Past experience In the 301 (h) program has shown
that applicants often neglect to describe the treatment and outfall system
in sufficient detail to allow evaluation of the technical merit of the appli-
35
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cation. Applicants should" provide a detailed description of this system
such that the reader will have a complete picture of the physical aspects of
the treatment and outfall system and will be able to understand the treatment
processes that occur therein. Information on dlffuser dimensions that are
used to determine the port flow distribution achieved by the outfall are
especially Important (see Question II.A.7 below), and should be specified as
accurately as possible. Figures and drawings with dimensions should be
Included 1f possible. In those descriptions, applicants should emphasize
any changes In the service area, treatment system, or outfall system that
were Implemented during the term of the existing permit. Water depths and
navigational coordinates of the outfalls as they exist should be correctly
specified. Water depth of the outfall should be specified as the water
depth at the midpoint of the dlffuser, referenced to mean sea level or mean
lower low water. Water depths and navigational coordinates found in
engineering design documents are often not correct because of changes in the
lengths and routes of the outfalls made during construction. Hence,
drawings of as-built conditions should be used.
II.A.3. Primary or equivalent treatment requirements [Part
125.60]
a. Provide data to demonstrate that your effluent meets at
least primary or equivalent treatment requirements as
defined in Subpart 125.58 (r)? [Part 125.60]
b. If your effluent does not meet primary or equivalent
treatment requirements, when do you plan to meet them?
Provide a detailed schedule, including design, construc-
t/on, start up, and full operation, with your appli-
cation. This requirement must be met by the effective
date of the new section 30I(h) modified permit.
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Large and small dischargers must respond.
Applicants must demonstrate that the treatment works Mill discharge,
at a minimum, primary treated effluent (or Its equivalent) at the time their
modification becomes effective, as mandated by Parts 125.57 and 125.60.
Applicants are advised that "primary or equivalent treatment" 1s defined in
Subpart 125.58(r) as "treatment by screening, sedimentation, and skimming
adequate to remove at least 30 percent of the biological oxygen demanding
material and of the suspended solids 1n the treatment works Influent, and
disinfection, where appropriate." To support this demonstration, the
applicant should supply monthly averaged data (typically monthly averages)
for Influent BOD, effluent 6005, suspended sol Ids, pH, and flow for the last
1-yr period. The form of such data (e.g., weekly averages, monthly
averages) should be specified precisely for each variable. Applicants
should also submit data on the predicted maximum 2- to 3-h flow for the new
end-of-permit year, and on measured effluent col 1form bacteria concentrations
1n a form that satisfies state water quality regulations. Where average
values are given (e.g., average dry-weather flow), applicants should specify
how they were calculated.
II.A.4. Effluent Limitations and Characteristics [Subparts
125.61(b) and 125.62(e)(2)]
a. Identify the final effluent limitations for 5-day
biochemical oxygen demand (BODg), suspended solids, and
pH upon which your application for a modification is
based:
- BOD$ mg/L
- Suspended solids mg/L
- pH (range)
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b. Provide data on the following effluent characteristics
for your current discharge as well as for the modified
discharge if different from the current discharge:
Flow (a? /sec):
- mini mm
- average dry weather
- average wet weather
- maximum
- annual average
(mg/L) for the following plant flows:
- minimum
- average dry weather
- average wet weather
- maximum
- annual average
Suspended solids (mg/L) for the following plant flows:
- minimum
- average dry weather
- average wet weather
- maximum
- annual average
Toxic pollutants and pesticides (ug/L):
- list each identified toxic pollutant and
pesticide
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pH:
- minimum
- maxima
Dissolved oxygen (ng/L, prior to chlorination) for the
following plant flows:
- minimum
- average dry weather
- average wet weather
- maximum
- annual average
Immediate dissolved oxygen demand (mg/L)
*** Large and small dischargers must respond.
Applicants should specify the effluent limitations requested for their
Section 301(h) modified permits, and the basis (e.g., monthly average
values) for those limits. Applicants must request specific limitations.
Except for pH, ranges of values or a list of alternatives are not acceptable.
The remaining Information on effluent characteristics can usually be found
by analyzing plant operating records.
II.A.5. Effluent Volume and Mass Emissions [Subpart 125.62(e)(2)
and Part 125.67]
a. Provide detailed analyses showing projections of
effluent volume (annual average, m*/sec) and mass
loadings (mt/yr) of BODg and suspended solids for the
design life of your treatment facility in 5 year incre-
ments. If the application is based upon an improved or
altered discharge, the projections must be provided with
and without the proposed improvements or alterations.
39
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b. Provide projections for the end of your 5 year permit
tent for 1) the treatment facility contributing
population and 2) the average dally total discharge
flow for the maximum month of the dry weather season.
Large and small dischargers oust respond.
Applicants should project effluent flows and mass emissions for the
term of the modified permit being requested, and for subsequent years at
5-yr Intervals. Projections should be based on annual average flows and
annual average effluent characteristics. Projections should reflect expected
changes In the service area and population over the term of the modified
permit being requested, and over the subsequent periods of time being
considered. Projections for the new end-of-permit year must be given,
including the average dally flow for the maximum month of the dry-weather
season, and average effluent characteristics for that month.
11.A.6. Average Dally Industrial Flow (a?/sec). Provide or
estimate the average dally Industrial Inflow to your treatment
facility for the same time Increments as in Question II.A.5
above. [Part 125.66]
*** Large and small dischargers must respond.
Annual average flow data will generally be sufficient for nonseasonal
(I.e., continuous operation) industries. For seasonal industries, average
daily flows for the periods of operation should be provided. Supporting
information (e.g., lists of industries and products manufactured) may be
required.
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II.A.7. Combined Sewer Overflows [Subpart 12S.67(b)]
a. Does (will) your collection and treatment system
Include combined sewer overflows?
b. If yes, provide a description of your plan for minimizing
combined sewer overflows to the receiving water.
*** Large and small dischargers must respond.
Locations, flow quantities, and frequency of overflows should be
specified. Data on total effluent flow and on effluent suspended solids and
BODs concentrations should be provided for times when overflows occur. The
effect of Increased Infiltration during the rainy season should be discussed.
Applicants should also provide a narrative description and schedule of a
plan for minimizing the discharge of combined sewer overflows to the
receiving water.
II.A.8. Outfall/Diffuser Design. Provide the following data for
your current discharge as well as for the modified discharge, if
different from the current discharge: [Subpart 125.62(a)(l)]
Diameter and length of the outfall(s) (meters)
Diameter and length of the diffuser(s) (meters)
Angle(s) of port orientatlon(s) from horizontal
(degrees)
Port diameter(s) (meters)
Orifice contraction coefficient(s), if known
Vertical distance from mean lower low water (or mean low
water) surface and outfall port(s) centerline (meters)
Number of ports
Port spacing (meters)
Design flow rate for each port, if multiple ports are
used (op/sec)
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Large and snail dischargers oust respond.
The information requested above should be available from the engineering
drawings for the treatment plant outfall and diffuser system. If risers are
used, information sufficient to compute the riser discharge coefficient
using the method of Koh (1973) should also be provided. For example, if the
riser consists of a vertical pipe the following details should be specified:
length and Inside diameter of the pipe, material from which It is made, and
diameter of the port orifice. Missing information should be so Indicated in
the responses to the foregoing questions. Because outfalls and diffusers
are often built somewhat differently than specified In the engineering
design drawings, applicants are advised to provide as-built information.
In addition to the foregoing Information, applicants should provide
information on the slope of the diffuser and the slope of the port center-
lines if they differ from that of the diffuser. If the diffuser ports
discharge to opposite sides of the diffuser, that Information should be
noted. The depths of the ports below mean lower low water (or mean low
water as applicable) should be provided, as should any variations in port
depths along the length of the diffuser.
The information provided In this section 1s routinely used in the
review process to determine whether the diffuser 1s well-designed hydrauli-
cally for the range of flow (dally minimum to daily maximum) expected during
the requested permit term. Among the characteristics of a well-designed
diffuser are uniform port flows and Individual port densimetric Froude
numbers that are always greater than 1. Methods for computing the port flow
distribution from a multiport diffuser are described by Grace (1978) and
Fischer et al. (1979). Discharge coefficients for risers can be computed
using methods provided by Koh (1973). [The explanation of these methods
provided by Fischer et al. (1979) should not be used because it 1s incomplete
and contains errors.] The effect of the bottom slope must be included in
the diffuser hydraulics computations because some diffusers behave properly
on a horizontal seafloor, but poorly on a sloping bottom, especially at low
flow rates.
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II.B. Receiving Water Description
II.B.I. Are you applying for a modification based on a discharge
to the ocean [Subpart 125.58(n)J or to a saline estuary [Subpart
125.58(v)]? [Subpart 125.59{a)J
Large and small dischargers oust respond.
"Ocean waters" are defined In Subpart 125.58(n) as coastal waters
landward of the baseline of the territorial seas, the deep waters of the
territorial seas, or the waters of the contiguous zone. Territorial seas
extend 3 ml outward from the baseline and the contiguous zone extends an
additional 9 ml. This term does not Include saline estuarine waters.
"Saline estuarine waters" are defined 1n Subpart 125.58(v) as semi-
enclosed coastal waters that have a free connection to the territorial sea,
undergo net seaward exchange with ocean waters, and have salinities
comparable to those of the ocean. Generally, these waters are near the
mouth of estuaries and have cross-sectional, annual mean salinities greater
than 25 ppt. It should be noted, however, that 25 ppt 1s used as a general
test 1n Subpart 125.58(v). The failure of the receiving water to meet this
salinity concentration does not absolutely preclude eligibility for
consideration under Section 301(h). However, where salinities fall
substantially below this concentration, applicants should be careful to
document that the waters Into which they discharge meet the other require-
ments of Subpart 125.58(v) (I.e., free connection to the territorial sea and
net seaward exchange with ocean waters).
Estuarine dischargers are advised that according to Subparts 125.57(a)
(9) and 125.59(b)(4), Section 301(h) modified permits may not be Issued for
discharges Into saline estuarine waters unless those waters meet all of the
following conditions:
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• Support a balanced Indigenous population of shellfish, fish,
and wildlife
• Allow for recreational activities in and on the waters
• Exhibit ambient water quality below applicable water quality
standards adopted for the protection of public water sup-
plies, shellfish, fish and wildlife or recreational activities
or such other standards necessary to assure support and
protection of such uses.
These conditions must be met, regardless of whether the applicant's dis-
charge contributes to departures from such conditions. According to
Section 301(h)(3) and Subpart 125.57(e), the foregoing prohibition does not
apply to discharges with Section 301(h) modified permits that were tenta-
tively or finally approved prior to the enactment of the Water Quality Act
of 1987. However, 1t 1s further stated that the foregoing prohibitions are
in force for all renewals of Section 301(h) modified permits that postdate
enactment of the Water Quality Act of 1987. Thus, all estuarine dischargers
must demonstrate that the receiving waters exhibit the above characteristics
(I.e., that they are not stressed) at the tine of permit re issuance,
regardless of whether such conditions existed at the tine the existing
Section 301(h) modified permit was issued.
II.B.2. Is your current discharge or modified discharge to
stressed waters as defined in Subpart 125.58(z)? If yes, what
are the pollution sources contributing to the stress? [Subparts
125.59(b)(4) and 125.62(f)J
*** Large and small dischargers must respond.
"Stressed waters" are defined In Subpart 125.58(z) as those ocean
waters in which the absence of a balanced indigenous population of shellfish,
fish, and wildlife is caused solely by human perturbations other than the
applicant's modified discharge. If the discharge is to stressed waters,
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Subpart 125.57(a) prohibits permit relssuance 1f the discharge alone or in
combination with pollutants from other sources adversely Impacts the
balanced Indigenous population, water quality, or recreational activities.
In addition, estuarine dischargers are advised that under Section 301(h)(9)
and Subparts 125.57(a)(2) and 125.59(b)(4), permits may not be reissued for
discharges to stressed saline estuarine waters.
Applicants that respond "no" to this question should state the basis
for their conclusion.
17.0.3. Provide a description and data on the seasonal circula-
tion patterns In the vicinity of your current and modified dis-
charge(s). [Subpart 125.62(a)]
*** Large and small dischargers must respond.
The applicant should provide sufficient Information on current speed
and direction 1n the vicinity of the discharge to predict the dispersion and
transport of diluted effluent. This Information should Include a description
of current patterns and general density structure on a seasonal basis, as
well as the variation over a tidal cycle. Estimates of near-surface and
near-bottom lowest 10 percentile current speeds should be provided, as well
as the locations of the current meters and the time span over which data
were collected. Hydraulic residence times and flushing characteristics
should be described for discharges Into estuaries and semi-enclosed bodies
of water. Any periods of net drift stagnation and natural upwelUng should
be described, Including changes in the current patterns and stratification.
The applicant should also discuss the occurrence of onshore surface
currents. Because onshore winds Induce onshore currents, wind speed and
direction statistics that are appropriate for the diffuser location should
also be provided. Useful sources of. Information Include data collected
during execution of the monitoring program for the existing modified permit,
data collected in the vicinity of the discharge by other researchers, and
45
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U.S. Department of Commerce tidal current tables (e.g., Tidal Current Tables
1988, Atlantic Coast of North America; Tidal Current Tables 1988, Pacific
Coast of North America and Asia).
Subpart 125.57(a)(9) prohibits Section 301(h) modified permits for
discharges where the dilution water contains "significant amounts of
previously discharged effluent from such treatment works." In responding to
Question II.B.3, applicants should discuss the potential for re-entra1nment
of previously discharged effluent. Re-entrainment Is a potential problem
primarily In receiving waters that exhibit poor flushing characteristics.
Such conditions can also occur, however, In open coastal areas during
periods of tidal or wind-driven current reversals, or temporary stagnation
of longshore coastal currents.
77.0.4. Oceanographic conditions in the vicinity of the current
and proposed modified discharge(s). Provide data on the fol-
lowing: [Subpart 125.62(a)]
Lowest ten percent He current speed (a/sec)
Predominant current speed (m/sec) and direction (true)
during the four seasons
Perlod(s) of maximum stratification (months)
Period(s) of natural upvelling events (duration and
frequency, months)
Density profiles during pericd(s) of maximum stratifi-
cation
*** Only large dischargers must respond.
The vertical and areal distribution of currents and water density in
both the near field and far field are needed to evaluate plume dilution,
wastefield transport, and potential re-entrainnent of previously discharged
effluent. Data collected from previous studies or nearby similar areas will
often be appropriate.
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The number and location of sampling stations needed to provide suf-
ficient data will depend on the bathymetric and hydrograpMc environment.
For open coastal sites with uniform bathymetry and minimal freshwater
Inflows, as few as five stations may be adequate. However, for an estuary
with significant freshwater Inflow and highly variable bathymetry, as many
as 50 stations may be necessary.
For existing discharges, the measurements should be made In the vicinity
of the outfall but outside the region directly Influenced by the discharge.
For relocated outfalls, measurements should be made In the vicinity of the
proposed discharge location. Current data should be obtained near the
surface, at the approximate depth of the wastefleld, and In the bottom 2 m
(6.6 ft) of the water column. Water depths at the stations should be
similar to the water depth at the site of the existing and relocated outfalls
(if present).
The duration of time within which these measurements should be obtained
1s dependent on the current regime and the variability of the density
structure. If the currents are predominantly tidal (which could be the case
for both open coastal and estuary sites), the current measurements should be
at approximately 30-min Intervals for not less than 29 days. If seasonal
changes in oceanographic conditions (e.g., low or variable longshore current
speeds or directions, upwelUng, shoreward transport, high and low runoff)
are significant, then Information should be obtained for each season. The
question is based on the presumption that periods of maximum stratification
will be important for calculating critical Initial dilutions. Field data on
other potentially critical periods (e.g., periods of longshore current
stagnation) may be necessary for determining whether this presumption is
true.
Reduction and presentation of data should be of sufficient detail to
support the interpretation and analyses performed 1n the application. The
following forms of data reduction and presentation are recommended:
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• Current persistence tables - Summary of the frequency• and
duration of specific current speed and direction events. For
example', currents with speeds between 10 and 15 cm/sec (0.33
and 0.49 ft/sec), directions between 260 and 280 degrees (T),
and durations of at least 1 h" occurred for 18 percent of the
data record.
• Current speed and direction frequency tables - Frequency of
specific current speed and direction Intervals. For example,
currents with speeds between 5 and 19 on/sec (0.16 to 0.33
ft/sec) occurred for 20 percent of the data record, and
currents with directions between 80 and 90 degrees (T)
occurred for 23 percent of the data record.
• Net coastal orthogonal component analysis - By determining the
predominant directions of current flow, a primary axis for
orthogonal component decomposition of each current vector can
be selected. The net component relative to each axis can
then be determined. If the currents do not exhibit pre-
dominant flow directions, an axis parallel to the local
bathymetry or 1n the direction of an area of significance can
be selected.
• Current mean and variance - For the predominant directions
of current flow or the selected primary axis, the mean and
variance of the current speed can be determined.
Guidance on Instrumentation and methods for oceanographlc data
collection Is provided 1n Design of 301(h) Monitoring Programs for Municipal
Hastewater Discharges to Marine Haters (Tetra Tech 1982a).
JJ.fl.5. Do the receiving waters for your discharge contain
significant amounts of effluent previously discharged from the
treatment works for which you are applying for a section 301 (h)
modified permit? [Subpart 125.57(a)(9)]
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Large and small dischargers oust respond.
Applicants should explain the basis for their response to this
question. Explanations should reflect the hydrographic characteristics of
the receiving environment and the behavior of the effluent plume through
time. Applicants that respond negatively to this question should demonstrate
that little or no previously discharged effluent will be advected Into the
ZID (after having been transported out of the ZID) to become entrained in the
effluent plume. This demonstration will be relatively simple for applicants
that discharge to open coastal areas where currents are unidirectional most
of the time. Those applicants should be able to plot effluent transport
through time, and thereby demonstrate that little or no effluent re-enters
the ZID. The demonstration will be much more complicated for dischargers
Into estuarlne environments where tidal currents oscillate. In estuaries,
effluent transported away from the ZID during the first half of a tidal
cycle may be transported back Into the ZIO on the second half of that cycle.
If effluent 1s likely to be transported back into the ZID, the applicant
should estimate the quantities of effluent that would be entrained.
In responding to this question, applicants should demonstrate that all
applicable water quality standards and water quality criteria are met at and
beyond the ZID boundary. If the dilution water contained significant
quantities of previously discharged effluent, it is unlikely that an
applicant would be able to meet all applicable water quality standards and
criteria. Responses given for Questions II.D.I, II.D.2, and II.D.3 of the
Application Questionnaire may be cited to support this demonstration.
1J.B.6. Ambient water quality conditions during the period(s) of
maximum stratification: at the zone of initial dilution (ZJD)
boundary, at other areas of potential impact, and at control
stations. [Subpart 125.62(a)]
a. Provide profiles (with depth) on the following for the
current discharge location and for the modified
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discharge location, If different from the .current
discharge:
• BOD5 (mg/L)
- Dissolved oxygen (mg/L)
- Suspended solids (mg/L)
- pH
• Temperature (°C)
• Salinity (ppt)
- Transparency (turbidity, percent Tight transmlttance)
- Other significant variables (e.g., nutrients, toxic
pollutants and pesticides, fecal coll form bacteria)
b. Provide available data on the following in the vicinity
of the current discharge location and for the modified
discharge location, If different from the current
discharge:
Dissolved oxygen (mg/L)
Suspended solids (mg/L)
- pH
Temperature (°C)
Salinity (ppt)
Transparency (turbidity, percent light trans-
mlttance)
Other significant variables (e.g., nutrients, toxic
pollutants and pesticides, fecal coliform bacteria)
c. Are there other periods when receiving water quality
conditions nay be more critical than the period(s) of
maximum stratification? If so, describe these other
critical periods and the data requested in 5.a. for the
other critical period(s). [Subpart 125.62(a)(l)]
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*** Large dischargers must respond to Parts a and c. Small dischargers must
respond to Parts b and c.
•
To document the periods of maximum stratification, temperature and
salinity profiles that are sufficient to determine the most stratified and
the typical conditions should be provided for each oceanographic season. The
•most stratified" temperature and salinity profile with depth 1s the profile
that will produce the lowest Initial dilution (see Question III.A.I for
definition). In some locations, such a profile has the steepest gradients of
temperature or salinity near mid-depth. Both temperature (expressed In
degrees C) and salinity (expressed In ppt) should be measured accurately to
two decimal places so that density (expressed In gm/ciP) can be computed
accurately to five decimal places. Also, only measured profiles should be
provided. Averages of measured profiles or "representative" profiles should
never be substituted. Density profiles should exhibit a stable water column
over the plume he1ght-of-r1se (I.e., no higher density water should overlie
lower density water). The minimum period of time over which oceanographic
data must be collected to establish typical and most stratified conditions
1s 1 yr. Because oceanographic conditions vary among years, 1t 1s recom-
mended that data collected over 5 yr be provided.
Sampling for nutrients, coll form bacteria, and other major variables
may be conducted at selected depths. Seech1 disc depth data should be
provided 1f transparency data are not available. However, because the
Seech 1 disc measures transparency from the surface down Into the water
column, use of the Seech 1 disc Is not appropriate when the effluent plume
does not surface. In addition, because sunlight greatly Increases die-off
rates of enteric bacteria (ElHot and Colwell 1985; Crane and Moore 1986),
bacteriological sampling should be conducted during early morning or at
night. Ambient water quality data collection procedures and requirements
are different for existing and for proposed or relocated discharge locations,
as discussed 1n Design of 301(h) Monitoring Program for Municipal Hastewater
Discharges to Marine Haters (Tetra Tech 1982a) and summarized below.
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For existing discharges, station locations should Include sampling at
the ZID boundaries (both upcurrent and downcurrent), at control (I.e.,
background ambient) stations, along the primary axis of the longshore
component of the current (both upcurrent and downcurrent), at Intermediate
upcurrent stations located between the ZID boundary and the upcurrent control
station, and 1n potential Impact areas (e.g., In the nearshore zone and
close to areas with distinctive habitats). The applicant should use
Information on local currents and wastefield dispersion patterns to select
sampling station locations In potentially Impacted areas. Sampling
stations located at the ZID boundary, at control stations along the primary
axis of current, and at Intermediate upcurrent stations should be 1n waters
of approximately the same depth. Control (I.e., background ambient)
stations should be located In areas not Influenced by the applicant's
discharge. The Intermediate upcurrent stations are Intended to represent the
approximate residual wastefield concentrations (I.e., affected ambient)
upcurrent of the discharge location to account for potential recirculatlon of
previously discharged effluent (by reversing tidal currents, upwelUng, or
stagnant net circulation). Data should be collected at the Intermediate and
ZID stations at least twice during the day (e.g., high and low tide slack),
to allow evaluation of short-term conditions. The duration of the longshore
current 1n relation to the time of sampling 1s an Important factor in
determining whether the Intermediate upcurrent stations are representative of
persistent conditions or of only a temporary plume reversal. For discharges
Involving outfall relocation, monitoring stations must be located at the
existing discharge site until cessation of that discharge, and at the
relocation site.
For each survey, the following Information should be submitted along
with the data: a chart showing exact locations of the stations, the depth at
which the measurements were taken, and the sampling dates and times. For
existing discharges, the applicant should state whether effluent was
discharging from the outfall at the time of the survey and should provide
the flow rate, BOD§ concentration, pH, and suspended solids concentration of
the effluent, If available. Any unusual meteorological or oceanographic
conditions (e.g., storms, onshore transport, low or stagnant longshore
52
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currents) should be discussed. Current data or other oceanographic
Information (e.g., drogues) should be deployed at the time of the survey to
determine the direction of movement of the wastefield.
Other periods when water quality conditions may be more critical
Include periods of maximum hydraulic loading from the POTW, exceptional
biological activity, poor background water quality, minimum stratification,
low net circulation, and low effective net flushing or low Intertidal
mixing. The latter three cases represent the potential for redrculatlon of
previously discharged effluent. The degree of redrculatlon would become
significant 1f 1t caused the discharge to violate water quality criteria at
the ZID boundary, when under normal circulation conditions it would meet the
criteria at the ZIO boundary.
II.0.7. Provide data on steady state sediment dissolved oxygen
demand and dissolved oxygen demand due to resuspension of
sediments in the vicinity of your current and modified discharge(s)
(mg/L/day).
*** only large dischargers must respond.
Dissolved oxygen depletion due to steady sediment demand and sediment
resuspension depends on sediment composition (e.g., grain size distribution
and organic content), sediment accumulation rates, current speeds, and
circulation patterns. Field or laboratory measurements can sometimes be
used to determine oxygen consumption rates. If such measurements are made,
the results and procedures used should be described.
II.C. Biological Conditions
In the Section 301(h) process, the determination of adverse biological
effects Involves assessing whether or not a BIP of shellfish, fish, and
wildlife exists in the vicinity of the discharge and in other areas
potentially affected by the discharge. Since the BIP concept forms an
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Integral part of the applicant's biological assessment, it is Important to
establish the meaning and Interpretation of the term in the context of a
Section 301(h) biological demonstration.
The term "population" does not mean a reproductive unit of a single
species but rather all biological communities existing 1n the receiving water
body. Similarly, the terms "shellfish," "fish," and "wildlife" should be
Interpreted to include any and all biological communities that may be
affected adversely by a marine POTU discharge [Subpart 125.58(y)].
A BIP is defined in the Section 301(h) regulations [Subpart 125.58(f)]
as "an ecological community which: 1) exhibits characteristics similar to
those of nearby, healthy communities existing under comparable but unpolluted
environmental conditions; or 2) may reasonably be expected to become re-
established 1n the polluted water body segment from adjacent waters if
sources of pollution were removed." Balanced indigenous populations occur
in unpolluted waters. The second part of the definition concerning the re-
establishment of communities Is included because of its relevance to pro-
posed, Improved discharges and to discharges into waters that are stressed
by sources of pollution other than the applicant's modified discharge.
The biological community characteristics that might be examined in an
evaluation of a BIP include (but are not limited to) species composition,
abundance, biomass, dominance, and diversity; spatial and temporal distri-
butions; growth and reproduction of populations; disease frequency; trophic
structure and productivity patterns; presence or absence of certain
Indicator species; bioaccumulatlon of toxic materials; and the occurrence of
mass mortalities of fish and invertebrates.
The first step in an applicant's BIP demonstration is to define the
"indigenous population" and establish the natural variability of the
"balanced population." Because U.S. EPA has determined thai these are
observable characteristics of natural that communities that exist in the
absence of human disturbance, a comparative strategy is found throughout the
Section 301(h) regulations. Biological variables of concern within and
54
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beyond the ZID should be compared to the range of natural variability found
1n comparable but unpolluted habitats.
The extent of documentation provided by the applicant 1n the marine
biological assessment should reflect the quality and quantity of the
effluent and the sensitivity of the receiving environment. Data requirements
will probably be least for applicants without substantial Industrial waste
sources whose discharges Into ocean waters do not potentially affect
distinctive habitats of limited distribution or Important fishery resources.
II.C.I. Provide a detailed description of representative
biological communities (e.g., plankton, macrobenthos, demersal
fish, etc.) In the vicinity of your current and modified dis~
charge(s): within the ZID, at the ZID boundary, at other areas of
potential discharge-related impact, and at reference (control)
sites. Community characteristics to be described shall include
(but not be limited to) species composition; abundance; dominance
and diversity; spatial/temporal distribution; growth and repro-
duction; disease frequency; trophic structure and productivity
patterns; presence of opportunistic species; bioaccumulation of
toxic materials; and the occurrence of mass mortalities.
*** Only large dischargers must respond.
Of the marine communities that may be affected by POTW discharges,
benthic communities or other communities that depend upon the benthos as a
food source (I.e., bottom-dwelling or bottom-feeding organisms) are usually
the most sensitive to pollutants. The rate of accumulation of discharged
solids and associated toxic substances near a POTW outfall affects the
magnitude and extent of Impacts to benthic communities. Based on the review
of biological conditions near both large and small discharges in a variety
of marine and estuarlne environments, it is apparent that the effects of
POTW discharges on the benthos are determined primarily by the influence of
the local hydrographic regimes on solids deposition and accumulation.
Observed biological effects in areas of solids accumulation are generally
55
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associated with decreased abundances of suspension-feeding animals and
Increased abundances of deposit-feeding animals. Such effects would be
expected to occur 1n sediments enriched with organic matter (e.g., from
POTWs).
The biological Information must be used to describe existing conditions
near the discharge and to determine whether or not a BIP exists (or will
exist) near the existing and modified discharges. This descriptive Infor-
mation must be used as the basis for the applicant's response to Question
III.D.I.
Applicants must submit descriptions of representative biological
communities (typically benthic Infauna and demersal fishes) 1n the receiving
water body. These descriptions will form the basis for the comparative BIP
demonstrations. It 1s Important that the applicant assess biological
community characteristics at a minimum of four sites: within the ZID, at or
Immediately beyond the ZIO boundary, within the expected discharge impact
area outside the ZID, and at appropriate reference sites.
Benthic data should be adequate to perform valid statistical and
community analyses for the purposes of determining whether or not the
following conditions exist:
• Benthic community structure in the discharge area differs
from that 1n the control area
• Benthic biomass in the discharge area differs from that in
the control area
• Opportunistic or pollution-tolerant species dominate benthic
communities in the discharge area
• Anoxic sediment conditions occur in the discharge area
56
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• Distinctive habitats of limited distribution (when present)
are adversely affected by the applicant's discharge
• The discharge contributes to or perpetrates ambient stresses
In the receiving environment (stressed water discharges only).
When the applicant's discharge Is located In an area of soft substrates,
sediment data must also be collected simultaneously with the benthlc com-
munity at each sampling station. These data should Include grain size
composition and a measure of organic content. Data on Kjeldahl nitrogen,
sediment 6005, and other sediment variables may also be collected. Sediment
data will be used to Identify correlations between benthlc community
structure and attributes of the sedimentary environment 1n the receiving
waters. Detailed guidance for evaluating benthlc community conditions in
the vicinity of outfall Is given 1n Appendix C.
I1.C.2. a. Are distinctive habitats of limited distribution
(such as kelp beds or coral reefs) located in areas potentially
affected by the modified discharge? [Subpart 125.62(c)]
b. If yes, provide information on type, extent, and location of
habitats.
*** Large and small dischargers must respond.
"Distinctive habitats of limited distribution" Include marine environ-
ments whose protection Is of special concern because of their ecological
significance or value to humans. These habitats include, but are not
limited to, coral reefs, kelp beds, seagrass meadows, salt marshes, spawning
or nursery areas for commercial species, sites of aesthetic appeal, and
rocky intertidal habitats (where -they are uncommon). Distinctive habitats
of limited distribution may be highly susceptible to the potential effects
of discharged suspended solids and nutrients on the unique floral (e.g.,
kelp, seagrass) or faunal (e.g., coral) components of the communities. The
potential for adverse effects of bioaccumulation of toxic substances is
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also relatively high because sessile floral and faunal organisms may
constitute Important trophic pathways within these communities. These
attached communities are also susceptible because of the potential for
continuous exposure to the effluent plume.
The applicant must describe distinctive habitats of limited distri-
bution within the receiving water environment, as follows:
• Kinds of distinctive habitats that occur In the general
vicinity of the discharge
• Areal extent and location of the habitats 1n the region (shown
on a map)
• Approximate distance from the discharge to sensitive habitats
• Physical characteristics of each distinctive habitat (water
column and substrate)
• Species composition of the flora and fauna
• Abundance or percent cover (as applicable) of resident
species
• Spatial and temporal variations 1n the biotic and abiotic
components of each distinctive habitat present.
The basic Information supplied by the applicant is expected to be descriptive
in nature, and should not require field surveys. Possible sources for
information on distinctive habitats Include contacts with local offices of
state conservation agencies, and literature and resource maps, which are
available for many areas.
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JJ.C.3. a. Are commercial or recreational fisheries located in
areas potentially affected by the discharge? [Subparts 125.62(c)
and (d)J
b. If yes, provide Information on types, location, and value of
fisheries.
Large and small dischargers oust respond.
Assessment of Impacts on fisheries 1s Important because of their
economic significance, their recreational potential, and the potential for
human consumption of contaminated organisms. The applicant should provide
Information on all fishery resources, both harvested and unharvested, near
the outfall and In other areas potentially Influenced by the discharge.
Emphasis should be placed upon regulatory or health-related factors that
prevent utilization of the resource, especially if such factors are related
to contamination. Sources of Information include natural resource agencies,
public health agencies, local anglers, and academic Institutions. For this
assessment, the applicant should specify where species of recreational or
commercial Importance occur (I.e., in the immediate vicinity of the
discharge, in the general region of the discharge, as migrants through the
region).
The immediate vicinity of a discharge includes the outfall structure
and the area associated with the discharge plume or clearly impacted by the
deposition of discharged sediment. The spatial extent of the fisheries
data will depend on the size and potential effects of the discharge, and on
the characteristics of the data. Many state fish and game agencies have
established statistical areas for recording fisheries data. In these cases,
an applicant can consider regional fisheries as those occurring in the
statistical block that includes the outfall. If the outfall is located
within an embayment or estuary where fisheries occur, the applicant should
address commercial and recreational fisheries throughout the embayment or
estuary.
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Distances of the various fishery resources from the discharge should be
provided. The following Information should be provided:
• Magnitude of the fisheries
Effort levels (e.g., number of vessels or number of
fishermen)
Economic value of commercial landings or sport fishery
• Temporal pattern of the fisheries.
II.D. State and Federal Laws fSuboarts 125.61 and 125.621 a)(1)1
II.D.I. Are there water quality standards applicable to the
following pollutants for which a modification is requested:
Biochemical oxygen demand or dissolved oxygen?
Suspended solids, turbidity, light transmission, light
scatteringt or maintenance of the euphotic zone?
pH of the receiving water?
*** Large and small dischargers must respond.
Applicants should contact the state water quality agency for an answer
to this question.
II.D.2. If yes, what is the water use classification for your
discharge area? Hhat are the applicable standards for your
discharge area for each of the parameters for which a modification
is requested? Provide a copy of all applicable water quality
standards or a citation to where they can be found.
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*** Large and saa77 dischargers oust respond.
Applicants should contact the state water quality agency for an answer
to this question.
71.0.3. If there are ho directly corresponding numerical
applicable water quality standards approved by EPA, provide data
to demonstrate that water quality criteria established under
Subsection 304(a)(1) of the Hater Quality Act are met at or beyond
the boundary of the ZID under critical environmental and treatment
plant conditions In the waters surrounding or adjacent to the
point at which your effluent 1s discharged. [Subpart 125.62-
(*)(!)]
At the time the 301(h) modification becomes effective, the applicant's
outfall and dlffuser must be located and designed to provide adequate
dilution, dispersion, and transport of wastewater to meet, at or beyond the
ZID, all applicable water quality standards and all applicable water quality
criteria for which there are no corresponding approved water quality
standards.
To demonstrate compliance with water quality criteria, applicants must
demonstrate the applicable numerical criteria are not exceeded after
critical Initial dilution. Guidance for performing such demonstrations is
given under Questions III.B.1-III.B.6 for conventional water quality vari-
ables, under Questions III.E.2 and III.F.I for conventional and pathogen
variables, and under Questions III.H.1-III.H.4 for toxic substances.
Applicants are reminded that demonstrations of compliance must be made for
the applicant's discharge in combination with pollutants from other sources.
Hence, data on pollutant loadings in the ambient receiving waters may be
required to calculate values of water quality variables after initial
dilution.
Another approach that the U.S. EPA has used to assess the potential
impacts of wastewater discharges on water quality and the biota in the
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receiving environment Is the water quality-based toxics control approach.
Although this approach Is not directly applicable to the demonstrations
required to answer this question, Information derived from Us use may be
used to further support the applicant's response. Guidance for Implementing
the water quality-based toxics control approach Is given 1n Appendix F.
II.D.4. Hill the modified discharge: [Subpart 125.59(b)(3)]
Be consistent with applicable State coastal zone
management program(s) approved under the Coastal Zone
Management Act as amended, 16 U.S.C. 1451 et seq.? [See
16 U.S.C. 1456(c)(3)(A)]
Be located In a marine sanctuary designated under Title
III of the Marine Protection, Research, and Sanctuaries
Act (HPRSA) as amended, 16 U.S.C. 1431 et seq., or in an
estuarlne sanctuary designated under the Coastal Zone
Management Act as amended, 16 U.S.C. 1461? If located
In a marine sanctuary designated under Title III of the
HPRSA, attach a copy of any certification or permit
required under regulations governing such marine
sanctuary. [See 16 U.S.C. 1432(f)(2)]
Be consistent with the Endangered Species Act as amended,
16 U.S.C. 1531 et seq.? Provide the names of any
threatened or endangered species that inhabit or obtain
nutrients from waters that nay be affected by the
modified discharge. Identify any critical habitat that
may be affected by the modified discharge and evaluate
whether the modified discharge will affect threatened or
endangered species or modify a critical habitat. [See
16 U.S.C. 1536 (a) (2) J
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Large and small dischargers oust respond.
Applicants should contact the National Marine Fisheries Service
(NMFS), U.S. Fish and Wildlife Service (USFWS), and applicable state coastal
zone management agency for answers to this question.
JJ.0.5. Are you aware of any State or Federal laws or regulations
(other than the Clean Hater Act or the three statutes identified
in item 4 above) or an Executive Order which is applicable to your
discharge? If yes, provide sufficient information to demonstrate
that your modified discharge will comply with such law(s),
regulation(s), or order(s). [Subpart 125.59 (b)(3)]
*** Large and small dischargers must respond.
Because each application for permit relssuance Is considered to be
an application for a new NPOES permit, applicants are required to provide
new determinations of compliance with all applicable local, state, and
federal laws and regulations, as Indicated above. Moreover, in response to
Question II.0.5, applicants should demonstrate compliance with federal water
quality criteria established by the U.S. EPA (1986a) [Subpart 125.60(b)].
Individual states often have water quality standards that must be met
Independently from federal water quality criteria. State standards that are
applicable to the discharge must be provided In this section, and determi-
nations of compliance with those standards must be provided 1n Section
III.B.6. Occasionally, state water quality standards are dependent on the
location of the outfall dlffuser. If the effluent wastefield 1s trans-
ported to a location having different standards than the dlffuser location,
then both sets of standards apply.
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III. TECHNICAL EVALUATION
III.A. Physical Characteristics of Discharge fSuboart 125.62fall
III.A.I. Uhat Is the critical Initial dilution for your current
and modified discharge(s) during 1) the period(s) of maximum
stratification? and 2) any other critical period(s) of discharge
volume/composition, water quality, biological seasons, or
oceanographic conditions?
*** large and small dischargers must respond.
POTW effluents are normally discharged Into marine waters through
outfalls that range from open-ended pipes to extensive diffusers. The
characteristics of the effluent and the receiving water, the diffuser
design, and the depth of discharge will determine the amount of effluent
dilution achieved. As shown in Figure 1, the lower-density (nonsaline)
discharged effluent creates a buoyant plume that rises rapidly toward the
water surface, entraining significant amounts of ambient saline water. The
momentum and buoyancy of the discharged effluent are primarily responsible
for the entrainment of dilution water (I.e., mixing of ambient saline water
with effluent). As the plume rises and entrains ambient saline water, Its
density increases and Its momentum and buoyancy decrease accordingly. If a
sufficient ambient vertical density gradient or zone of stratification
(like a pycnocline or thermocline) Is present, the plume will spread
horizontally at the level of neutral buoyancy (I.e., where the plume density
equals ambient water density). If a sufficient density gradient 1s not
present, the diluted effluent will reach the water surface and flow
horizontally. The vertical distance from the discharge points to the
centerline of the plume when it reaches the level of neutral buoyancy or the
water surface is called the "height-of-r1se" (sometimes referred to as the
height to "trapping" or "equilibrium" level).
The dilution achieved at the completion of this process is called the
"initial dilution." Dilution is the ratio of the total volume of a sample
64
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SURFACE
T
TRAPPING
DEPTH
PYCNOCUNE
REGION
TRANSITION
ZONE
Figure 1. Wastefield generated by a simple ocean outfall.
65
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(ambient water plus effluent) to the volume of effluent in the sanlple. A
dilution of 100 1s, therefore, a mixture composed of 99 parts of ambient
water to 1 part of effluent. The Initial dilution is a critical parameter
relative to compliance with water quality standards and is thus discussed in
some detail In the evaluation of both large and small applications. The
magnitude of Initial dilution achieved 1s dependent on ambient density
gradients and diffuser design.
The lowest (I.e., critical) Initial dilution must be computed for each
of the critical environmental seasons. The predicted peak 2- to 3-h
effluent flow for the new end-of-permit year and the current speed no higher
than the lowest 10 percent11e current speed must be used. A simplified
procedure for computing Initial dilution is described in Appendix A. Five
U.S. EPA-approved computer models (I.e., UPLJME, UOUTPLM, UMERGE, UDKHDEN,
ULINE) and several analytical formulas for computing Initial dilution are
described by Muellenhoff et al. (1985a,b). ASCII files containing FORTRAN
code for these models are available from the National Technical Information
Service, 5285 Port Royal Road, Springfield, VA 22161 [(703) 487-4650].
These files are on either nine-track tape or on floppy diskettes that can be
read by an IBM-compatible personal computer. Muellenhoff et al. (1985a)
discuss guidelines for use of the models. During computation of initial
dilution by one of these methods, the flow from each of the ports modeled
should be approximately constant within a section of the diffuser. The
initial dilution and trapping depth for each section should be a flow-rate
averaged to obtain the Initial dilution and trapping depth, respectively,
for the entire diffuser. The depth of the discharge 1s determined as the
depth of section below mean lower low water or mean low water, or as the
average for the diffuser. If the adjacent ports discharge on opposite
sides of the diffuser, the port spacing should be equal to the distance
between ports discharging on the same side of the diffuser. (This stipu-
lation 1s applicable to UMERGE and UDKHDEN, but not JUNE.) Sufficient
documentation of the methods and parameters used by the applicant to
calculate initial dilution must be provided so that the results obtained can
be duplicated independently.
66
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For Many applicants, conditions specified In the original application
will not have changed, and 1t will be necessary only to reproduce the
calculations given 1n the original application. Other applicants will find,
however, that monitoring data or other Information collected during the term
of the original modified permit requires that new calculations be performed.
For example, new calculations will be required where the water column
density profile Is better defined, effluent flows have changed or are
expected to change, or the number of open ports has changed.
III.A.2. Hhat are the dimensions of the zone of initial dilution
for your modified dlscharge(s)?
*** Large and small dischargers must respond.
The ZID 1s the region of Initial mixing surrounding or adjacent to the
end of the outfall pipe or diffuser ports and Includes the underlying
seabed. The ZID describes an area In which Inhabitants, Including the
benthos, may be chronically exposed to concentrations of pollutants in
violation of water quality standards and criteria or at least to concen-
trations more severe than those predicted for critical conditions. The ZID
1s not Intended to describe the area bounding the entire mixing process for
all conditions, or the total area Impacted by the sedimentation of settleable
material.
In general, the ZID can be considered to Include that bottom area and
the water column above that area circumscribed by D distance from any point
of the diffuser, where D 1s equal to the water depth. Several different
diffuser configurations and corresponding ZID dimensions are shown in
Figure 2. The water depth used should be the maximum water depth along the
diffuser axes with respect to mean lower low water or mean low water, as
applicable.
Unless changes to the outfall system have been made or are anticipated,
or unless Incorrect water depths or outfall characteristics were used In the
original Section 301(h) application, the calculation presented here should
67
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Y-DIFFUSER
SINGLE POINT
LINEAR DIFFUSER
L-DIFFUSER
Note: d » Water Depth
Figure 2. Diffuser types and corresponding ZIO configurations.
68
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be Identical to that presented in the original application. Repetition of
the calculation 1n the application for relssuance of the Section 301(h)
modified permit Is necessary to confirm that all values used In the original
application were correct, and that the outfall system has not, and will not,
change over the term of the new permit.
III.A.3. Hhat are the effects of ambient currents and stratifi-
cation on dispersion and transport of the discharge plune/waste-
fleld?
*** Only large dischargers oust respond.
A general description of the ambient currents expected within the
Influence of the dlffuser site Is required by U.S. EPA. Since this descrip-
tion 1s primarily of use in determining where the effluent wastefield Is
likely to be transported during several days' time, the response to this
subsection should be of sufficient detail for this purpose. Knowledge of
the subsequent movement of the wastefield is also needed to address the
potential for re-entralnment of previously discharged effluent, which could
effectively increase wastefield concentrations at the boundary of the ZID.
The applicant should take Into account that dilution water is entrained into
the effluent plume throughout the depth over which the plume rises. The
diluted wastefield may be transported by either surface currents or
subpycnocllne currents at different times during a tidal cycle. In a region
where currents are predominantly tidal, current persistence and the mean
current speed and its variance with respect to the primary directions of
water flow should be given. If the currents have large components unrelated
to tidal influences (e.g., wind-induced currents), then a more detailed
analysis should be performed. The mean, variance, and direction of the
tidal component should be determined, and a synopsis of the nontidal
current speed, direction, and persistence should be provided. Vertical
variations in currents are important at depths where the effluent wastefield
is trapped.
69
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The basis for the current estimates should.be provided. Acceptable
sources of Information are site-specific measurements and published
measurements or predictions. The Tidal Current Tables published annually by
the U.S. Department of Commerce (see National Ocean Survey 1988a,b) provide
tidal current Information for a large number of locations. Information from
other published documents 1s usable 1f the documents are available to U.S.
EPA on request. -- ..•-•-
Expected or measured effluent dilutions at Important shoreline
stations should be Included. Chapters B-I, B-III, and B-IV in Appendix B of
this document provide further guidance on computing farfield dilutions for
water quality variables.
Under certain circumstances, such as low nontidal currents or reversing
tidal currents, the affected "ambient" water quality concentrations of the
ocean water with which the plume Is diluted nay be temporarily higher than
the normal background concentration (I.e., when the ocean water 1s unaffected
by the discharge). This issue 1s of primary concern for discharges located
in estuaries or semi-enclosed water bodies but may also be of concern for
open costal sites. To ensure that the discharge meets all applicable water
quality criteria during these other critical conditions, the applicant
should evaluate the recirculation potential of the existing or proposed
discharge through an analysis of currents, dye or field mixing studies (for
existing discharges only), numerical modeling analyses (for relocated or
proposed new discharges), or evaluation of water quality data collected
during the existing discharge monitoring program. A monitoring strategy 1s
described below in guidance for Question III.F (Establishment of a Monitoring
Program).
Dye studies are particularly useful to evaluate the recirculation
potential under short-term tidal cycle Influences for existing discharges.
Current-meter data should be made available to evaluate both the high
frequency (tidal) and low frequency (nontidal) current regimes that exist at
the time of the dye study.
70
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For relocated or proposed new discharges, numerical circulation and
transport models are the most useful methods for assessing the effects of
ambient currents and stratification on dispersion and transport of the
wastefleld and for estimating the potential for redrculation of previously
discharged effluent. There are two general approaches. The first 1s to
simulate a conservative substance (I.e., no decay) as a tracer for the
wastefleld to estimate numerical dilution factors surrounding the discharge.
These dilution factors can be used to estimate the affected ambient
concentration of any water quality variable as Input to the Initial and
subsequent dilution techniques presented- elsewhere 1n this document. The
second approach, which Is more complex, Is to directly simulate the water
quality variables and kinetic processes that govern their fate (e.g., BOD
decay, suspected solids settling).
Several specific guidelines can be offered to applicants In the use of
numerical models. Typically, the most critical conditions for redrculation
and build-up of previously discharged effluent would occur when the water
column 1s density-stratified 1n the presence of tidally reversing currents
and low nontldal currents, and the wastefleld remains submerged below the
pycnocline following Initial dilution. If such conditions occur at the
applicant's outfall site, the numerical model should be layered vertically,
with a minimum of two layers. The plume should be discharged Into the
bottom layer to simulate the submerged discharge. The applicant should set
up the grid system for the numerical model such that the smallest segments
are located in the vicinity of the dlfruser and gradually increase in size
with distance from the dlffuser. The applicant might choose to experiment
with grid configuration by starting with a coarse grid and then decreasing
the grid size until the model results do not change greatly.
A variety of numerical circulation and transport models exist with
various levels of detail, user documentation, and applicability. Examples
of potentially applicable models Include CAFE/DISPER (Wang and Connor 1975;
Christodoulou et al. 1976a,b; Pagenkopf et al. 1976); TEA/ELA (Baptlsta et
al. 1984; Westerink et al. 1985); AriathuHa (1982); Spaulding and Ravish
(1984); and Sheng and Butler (1984). The applicant must use a model that is
71
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supported by a fully documented computer program so that U.S. EPA and other
Interested parties may conduct analyses (I.e., run simulations) on generally
available computer systems.
III.A.4. Will there be significant sedimentation of suspended
solids In the vicinity of the modified discharge?
*** Only small dischargers mist respond.
The accumulation of suspended solids from municipal wastewater
discharges may lower dissolved oxygen concentrations in near-bottom waters
and cause changes 1n benthic communities. Accumulation of suspended solids
In the vicinity of a discharge 1s Influenced by the amount of sol Ids
discharged, the settling velocity distribution of the particles In the
discharge, the plume he1ght-of-r1se, and current velocities. Hence,
sedimentation of suspended solids Is generally of little concern for small
discharges Into well-flushed receiving environments.
In response to this question, the applicant must predict the seabed
accumulation that results from the discharge of suspended solids Into the
receiving water. The applicant may use any applicable well-documented
sedimentation model. A simplified approach for small dischargers 1s provided
in Chapter B-I of Appendix B. A simplified sedimentation model for large
discharges, or small dischargers for whom the simplified approach 1s not
appropriate, Is also described In Chapter B-I of Appendix B. The sedimen-
tation model DECAL (a simplified Deposition Calculation) 1s available as an
Ocean Data Evaluation System (ODES) tool.
III.A.5. Sedimentation of suspended solids.
a. Hhat fraction of the modified discharge's suspended solids
will accumulate within the vicinity of the modified discharge?
72
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b. Hhat are the calculated area(s) and rate(s) of -sediment
accumulation within the vicinity of the modified discharge(s)
(g/ot/yr)?
c. Hhat is the fate of settleable solids transported beyond the
calculated sediment accumulation area?
Only large dischargers must respond.
Information on the fate of suspended solids 1s needed to calculate
oxygen consumption rates and Interpret biological data. Settling velocity
distributions of the effluent should be provided, 1f available. Graphs that
show the settling velocity (cm/sec) and percent of solids that settle at
that velocity or less are preferred. The suspended solids concentration
(mg/L), test conditions, and laboratory procedures that are used should be
described.
The applicant should calculate whether substantial sedimentation of
suspended solids occurs. These calculations should be made for the annual
period and for the critical 90-day period (I.e., the 90-day period during
which the highest sedimentation rate occurs). The average plume height-of-
rise with respect to the seafloor should be used 1n these calculations. A
simplified procedure for calculating the effect of sedimentation 1s described
In Chapter B-I of Appendix B.
III.B. Compliance with Applicable Water Quality Standards fSuboarts
125.61fb) and 225.62fa)1
III.B.I. Hhat is the concentration of dissolved oxygen immediately
following initial dilution for the period(s) of maximum stratifi-
cation and any other critical period(s) of discharge volume/compo-
sition, water quality, biological seasons, or oceanographic
conditions?
73
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large and small dischargers oust respond.
Dissolved oxygen 1n the receiving water 1s diminished by the low oxygen
content and Immediate dissolved oxygen demand (IDOO) of the effluent within
the ZID and by the oxidation of organic material 1n the diluted effluent
beyond the ZIO. A simplified procedure for calculating the dissolved oxygen
concentration Immediately following Initial dilution 1s explained 1n
Chapter B-II of Appendix B. Note that some states limit the maximum
allowable depression 1n dissolved oxygen concentration, and that the maximum
dissolved oxygen depression may not occur during the season that has the
lowest Initial dilution.
III.B.2. Hhat Is the farfield dissolved oxygen depression and
resulting concentration due to BOD exertion of the wastefield
during the period(s) of maximum stratification and any other
critical period(s)?
*** Large and small dischargers oust respond.
A simplified procedure for computing the farfield dissolved oxygen
depression 1s given 1n Chapter B-III of Appendix B.
JJJ.fi.3. What are the dissolved oxygen depressions and resulting
concentrations near the bottom due to steady sediment demand and
resuspension of sediments?
*** Only large dischargers must respond.
Suspended sol Ids that accumulate on the seabed may exert a dissolved
oxygen demand due to continuous oxidation of organic material at the
sediment surface and occasional rapid oxidation of resuspended sediments.
Estimates of dissolved oxygen depressions that result from steady sediment
demand and resuspension of solids should be made using the methods described
in Chapter B-IV of Appendix B. If field or laboratory measurements are
available, the results can be used in these analyses.
74
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III.£.4. Hhat Is the Increase in receiving water suspended solids
concentration immediately following initial dilution of the
nodi fled discharge(s)?
*** large and small dischargers oust respond.
Suspended solids 1n the water column may reduce light transmlttance and
thus water clarity. Reduction of the depth to which sunlight penetrates may
also affect biological communities within the water column. The suspended
solids concentration following Initial dilution can be-estimated by a simple
mass balance calculation.
The formula provided 1n Chapter B-V of Appendix B should be used to
calculate the receiving water suspended solids concentration following
critical Initial dilution. In cases where the Initial dilution or the
concentration of suspended sol Ids 1n the effluent have not changed since the
original application was submitted, and are not expected to change over the
term of the new permit, 1t will be necessary only to reproduce the calcu-
lation provided 1n the original application. However, changes in either
variable will necessitate recalculating the receiving water suspended solids
concentration.
III.B.5. Hhat is the change in receiving water pH immediately
following initial dilution of the modified discharge(s)?
*** Only large dischargers must respond.
The pH of the receiving water can be affected by the discharge of
highly acidic or highly alkaline wastes. Final pH values after initial
dilution can be estimated from field measurements or calculated from
carbonate system alkalinity relationships.
In most settings, the influence of a municipal waste discharge on the
receiving water pH 1s small. . This section provides a method to calculate
75
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the pH change of receiving waters due to a waste discharge and to determine
whether standards are violated.
The pH at completion of Initial dilution can be estimated from Table 1.
The values shown 1n this table were generated by a pH-alkallnlty model
(based on the carbonate system) that simulates the mixing of effluent and
seawater. The methods used to calculate the values in this table are
explained 1n Chapter B-VI of Appendix B. Because waste plumes are usually
submerged during Initial dilution, no exchange with the atmosphere 1s
Included. The results are based on a seawater alkalinity of 2.3 meq/L
(Stumm and Morgan 1981), and dissociation constants from Stunrn and Morgan
(1981) and Dlckson and R1ley (1979).
Effluent alkalinity depends on the alkalinity of the source water and
any Infiltrating water, the type of treatment process, and the volume and
type of Industrial waste that enters the treatment plant. Effluent alka-
linity can range from 0 to 6.0 meq/L. A typical value for effluent
alkalinity 1s 2 meq/L or higher (Metcalf and Eddy 1979). Because alkalinity
data are scarce, final pH values calculated for a range of alka!1n1t1es are
provided in Table 1. If significant Industrial waste Is present In an
effluent, or 1f pure oxygen or nltrlficatlon-denitrlflcatlon treatment
processes are used, effluent pH and alkalinity should be measured. For
cases of weak primary effluents with no Industrial waste components, an
alkalinity value of 0.1 meq/L with an effluent pH of 6.0 can be used to
estimate the final pH. If the lowest effluent pH 1s 6.5 or higher, an
alkalinity value of 0.5 meq/L with an effluent pH of 6.5 can be used to
estimate the final pH.
The applicant should first estimate the pH at completion of initial
dilution for the case when the effluent pH 1s 6.0 and the ambient pH is
equal to the minimum ambient pH in the vicinity of the discharge. The
estimated value should be compared with the appropriate state standard to
determine whether the standard is met.
76
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TABLE 1. ESTIMATE) pH VALUES AFTER INITIAL DILUTION
Seanter
Tenp. °c
Sea water
PH
7.00
7.50
7.70
8.00
8.30
8.50
7.00
7.50
7.70
8.00
8.30
8.50
7.00
7.50
7.70
8.00
8.30
8.50
7.00
7.50
7.70
8.00
8.30
8.50
7.00
7.50
7.70
8.00
8.30
8.50
7.00
7.50
7.70
8.00
8.30
8.50
10
6.97
7.40
7.58
7.89
8.23
8.46
6.80
7.05
7.13
7.29
7.57
7.90
6.70
6.89
6.94
7.04
7.20
7.39
6.53
6.64
6.67
6.72
6.79
6.86
6.95
7.35
7.52
7.81
8.16
8.40
6.90
7.23
7.35
7.59
7.96
8.24
25
6.98
7.46
7.65
7.96
8.27
8.48
6.91
7.28
7.42
7.69
8.06
8.32
6.85
7.17
7.28
7.50
7.86
8.17
6.75
6.97
7.04
7.17
7.39
7.67
6.98
7.44
7.62
7.93
8.25
8.46
6.95
7.38
7.55
7.84
8.18
8.41
5°C
50
6.99
7.48
7.67
7.98
8.28
8.49
6.95
7.38
7.55
7.85
8.19
8.41
6.92
7.31
7.46
7.74
8.11
8.35
6.85
7.17
7.28
7.50
7.87
8.17
6.99
7.47
7.66
7.96
8.27
8.48
6.97
7.43
7.62
7.92
8.24
8.45
75
6.99
7.48
7.68
7.98
8.29
8.49
6.96
7.42
7.60
7.90
8.23
8.44
6.94
7.37
7.54
7.83
8.18
8.40
6.90
7.26
7.40
7.66
8.03
8.29
6.99
7.48
7.67
7.97
8.28
8.48
6.98
7.45
7.65
7.95
8.26
8.47
100
6.99
7.49
7.68
7.99
8.29
8.49
6.97
7.43
7.62
7.92
8.24
8.46
6.96
7.40
7.57
7.87
8.21
8.43
6.92
7.31
7.46
7.74
8.11
8.35
6.99
7.48
7.68
7.98
8.28
8.49
6.98
7.46
7.66
7.96
8.27
8.48
15°C
10 25 50 75
Effluent pH - 6.0 Alk •
6.97 6.99 6.99 6.99
7.42 7.47 7.48 7.49
7.61 7.66 7.68 7.69
7.93 7.97 7.99 7.99
8.27 8.29 8.29 8.29
8.48 8.49 8.49 8.49
Effluent pH * 6.0 Alk •
6.80 6.91 6.95 6.96
7.07 7.30 7.39 7.42
7.18 7.46 7.58 7.62
7.40 7.78 7.90 7.93
7.82 8.15 8.23 8.25
8.15 8.38 8.44 8.46
Effluent pH - 6.0 Alk «
6.70 6.86 6.92 6.94
6.90 7.19 7.33 7.38
6.97 7.33 7.50 7.56
7.12 7.62 7.82 7.88
7.40 8.02 8.17 8.22
7.77 8.29 8.40 8.43
Effluent pH = 6.0 Alk =
6.53 6.75 6.86 6.90
6.65 6.99 7.19 7.28
6.69 7.08 7.33 7.44
6.76 7.27 7.62 7.75
6.88 7.64 8.02 8.12
7.01 8.00 8.28 8.36
Effluent pH « 6.5 Alk >
6.95 6.98 6.99 6.99
7.37 7.45 7.47 7.48
7.55 7.64 7.67 7.68
7.87 7.95 7.97 7.98
8.22 8.27 8.28 8.29
8.44 8.47 8.49 8.49
Effluent pH * 6.5 Alk *
6.90 6.96 6.98 6.98
7.25 7.39 7.44 7.46
7.40 7.58 7.64 7.66
7.70 7.89 7.95 7.96
8.09 8.22 8.26 8.27
8.33 8.44 8.47 8.48
100
0.1
6.99
7.49
7.69
7.99
8.29
8.49
0.6
6.97
7.44
7.64
7.95
8.26
8.47
1.0
6.96
7.41
7.60
7.91
8.24
8.45
2.0
6.92
7.33
7.50
7.82
8.17
8.40
0.5
6.99
7.48
7.68
7.98
8.29
8.49
1.0
6.98
7.47
7.-7
7.97
8.28
8.48
10
6.97
7.43
7.63
7.96
8.28
8.49
6.80
7.09
7.22
7.53
7.98
8.25
6.71
6.92
7.01
7.22
7.65
8.01
6.54
6.67
6.71
6.81
6.99
7.23
6.95
7.39
7.58
7.91
8.24
8.46
6.90
7.27
7.44
7.78
8.15
8.38
25
6.99
7.47
7.67
7.98
8.29
8.49
6.91
7.32
7.50
7.84
8.19
8.41
6.86
7.21
7.38
7.71
8.10
8.34
6.75
7.01
7.12
7.39
7.84
8.15
6.98
7.45
7.65
7.97
8.28
8.48
6.96
7.40
7.60
7.92
8.24
8.45
25°C
50
6.99
7.48
7.68
7.99
8.29
8.49
6.95
7.40
7.60
7.92
8.25
8.46
6.92
7.34
7.53
7.87
8.21
8.42
6.86
7.21
7.38
7.71
8.10
8.34
6.99
7.47
7.67
7.98
8.29
8.49
6.98
7.45
7.65
7.96
8.27
8.47
75
6.99
7.49
7.69
7.99
8.29
8.49
6.97
7.43
7.63
7.95
8.26
8.47
6.95
7.39
7.59
7.91
8.24
8.45
6.90
7.30
7.48
7.82
8.17
8.39
6.99
7.48
7.68
7.99
8.29
8.49
6.98
7.46
7.66
7.97
8.28
8.48
100
6.99
7.49
7.69
7.99
8.29
8.49
6.97
7.45
7.65
7.96
8.27
8.48
6.96
7.42
7.62
7.93
8.25
8.46
6.92
7.34
7.53
7.86
8.20
8.42
6.99
7.48
7.69
7.99
8.29
8.49
6.99
7.47
7.67
7.98
8.28
8.48
77
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TABLE 1. (Continued)
Seauater
Tesp. °C
Seawater
PH
7.00
7.50
7.70
8.00
8.30
8.50
7.00
7.50
7.70
8.00
8.30
8.50
7.00
7.50
7.70
8.00
8.30
8.50
7.00
7.50
7.70
8.00
8.30
8.50
10
-.
6.82
7.06
7.U
7.28
7.54
7.85
7.06
7.56
7.75
8.03
8.31
8.50
7.10
7.59
7.76
8.02
8.29
8.47
7.14
7.61
7.78
8.02
8.27
8.44
25
6.91
7.28
7.42
7.68
8.04
8.30
7.02
7.52
7.72
8.01
8.30
8.50
7.04
7.53
7.72
8.01
8.29
8.48
7.05
7.54
7.73
8.00
8.28
8.47
5°C
50
6.95
7.38
7.55
7.84
8.18
8.40
7.01
7.51
7.70
8.00
8.30
8.50
7.02
7.51
7.71
8.00
8.29
8.49
7.02
7.52
7.71
8.00
8.29
8.48
75
6.97
7.41
7.59
7.89
8.22
8.44
7.00
7.50
7.70
8.00
8.30
8.50
7.01
7.51
7.70
8.00
8.29
8.49
7.01
7.51
7.71
8.00
8.29
8.49
100
6.97
7.43
7.62
7.92
8.24
8.45
7.00
7.50
7.70
8.00
8.30
8.50
7.00
7.50
7.70
8.00
8.29
8.49
7.01
7.51
7.70
8.00
8.29
8.49
15°C
10 25. 50 75
Effluent pH » 6.5 Alk *
6.82 6.91 6.95 6.97
7.08 7.29 7.39 7.42
7.18 7.46 7.57 7.61
7.39 7.76 7.89 7.92
7.78 8.13 8.22 8.24
8.10 8.36 8.43 8.45
Effluent pH « 9.0 Alk -
7.06 7.02 7.01 7.00
7.56 7.52 7.51 7.50
7.75 7.72 7.71 7.70
8.03 8.01 8.00 8.00
8.31 8.30 8.30 8.30
8.50 8.50 8.50 8.50
Effluent pH » 9.0 Alk -
7.10 7.04 7.02 7.01
7.59 7.53 7.51 7.51
7.76 7.72 7.71 7.70
8.02 8.00 8.00 8.00
8.28 8.29 8.29 8.29
8.46 8.48 8.49 8.49
Effluent pH - 9.0 Alk »
7.U 7.05 7.02 7.01
7.61 7.54 7.52 7.51
7.77 7.73 7.71 7.71
8.01 8.00 8.00 8.00
8.26 8.28 8.29 8.29
8.43 8.47 8.48 8.49
100
2.0
6.97
7.44
7.63
7.94
8.26
8.46
2.0
7.00
7.50
7.70
8.00
8.30
8.50
4.9
7.01
7.50
7.70
8.00
8.29
8.49
6.0
7.01
7.51
7.70
8.00
8.29
8.49
10
6.82
7.10
7.22
7.50
7.93
8.21
7.07
7.56
7.75
8.03
8.31
8.50
7.11
7.59
7.76
8.02
8.28
8.46
7.15
7.61
7.77
8.01
8.26
8.43
25
6.92
7.31
7.49
7.82
8.17
8.39
7.02
7.52
7.72
8.01
8.30
8.50
7.04
7.53
7.72
8.00
8.29
8.48
7.06
7.54
7.73
8.00
8.28
8.47
25°C
50
6.95
7.40
7.60
7.91
8.24
8.45
7.01
7.51
7.71
8.00
8.30
8.50
7.02
7.51
7.71
8.00
8.29
8.49
7.03
7.52
7.71
8.00
8.29
8.48
75
6.97
7.43
7.63
7.94
8.26
8.46
7.00
7.50
7.70
8.00
8.30
8.49
7.01
7.51
7.70
8.00
8.29
8.49
7.02
7.51
7.71
8.00
8.29
8.48
100
6.97
7.45
7.65
7.96
8.27
8.47
7.00
7.50
7.70
8.00
8.30
8.49
7.01
7.50
7.70
8.00
8.29
8.49
7.51
7.70
8.00
8.29
8.49
78
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The applicant may also perform laboratory tests when the predicted pH
values 1n Table 1 Indicate that contraventions of pH standards are possible.
Some of the buffering constituents In municipal effluents are not readily
quantified (e.g., organic add llgands), and have not been Included in the
calculations used to produce the table. The laboratory test would Include
measuring pH of effluent-receiving water mixtures as discussed below.
If the effluent pH drops below 6.0, the applicant should Indicate the
number of times per year effluent pH values fell below 6.0 and the suspected
cause(s) of those low values. If effluent pH values below 6.0 occur
frequently, a laboratory test of pH after mixing the effluent and receiving
water should be performed for the critical conditions. The sample mixture
should not be allowed to equilibrate with the atmosphere. The pH should be
measured at close Intervals until no further change in pH 1s observed. The
applicant should describe conditions of the test, including temperature, pH,
and alkalinity of the effluent and receiving water; initial dilution; and
the measured values after mixing. The measured values should then be
compared with the applicable standard to determine whether a violation is
likely. The frequency of violations should be estimated.
III.B.6. Does (will) the modified discharge comply with applicable
water quality standards for:
Dissolved oxygen?
Suspended solids or surrogate standards?
pH?
*** Large and small dischargers must respond.
The applicant must demonstrate compliance with applicable receiving
water quality standards. Typically, standards exist for dissolved oxygen,
suspended sol Ids, and pH, in which case the results of previous sections may
be used. If a quantitative state standard exists for turbidity expressed in
a given turbidity unit, then turbidity of the effluent and the receiving
water (expressed in turbidity units as a function of concentration) should
be measured to demonstrate that the standard will be met. Other state
79
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standards may also exist, such as for col1form bacteria concentrations at
the edge of a mixing zone. Monitoring data collected during the term of the
original Section . 301(h) permit may also be useful for demonstrating
compliance with applicable receiving water standards and criteria, and for
verifying predictions made 1n the original application.
According to Subpart 125.57(a)(9), permits nay not be Issued 1f the
dilution water for the discharge contains substantial amounts of previously
discharged effluent. In general, this criterion will be met 1f all water
quality standards are met.
Detailed guidance for assessing compliance with specific water quality
standards 1s provided 1n Chapters B-VII and B-VIII of Appendix B.
7/7.5.7. Provide the determination required by Subpart 125.61 (b)-
(2) or, If the determination has not yet been received, a copy of
a letter to the appropriate agency(s) requesting the required
determination.
*** Large and small dischargers must respond.
Because all applications for reIssuance of Section 301(h) modified
permits are considered applications for new NPDES permits, all applicants are
required to provide new determinations of compliance, as required by
Subpart 125.61(b)(2). A copy of the letter that requests the required
determination may be provided if the determination by the appropriate state
agency has not yet been received.
777.C. Impact on Public Hater Supplies fSubpart 125.62(b)l
III.C.I. Is there a planned or existing public water supply
(desalinizatlon facility) intake in the vicinity of the current or
modified discharge?
*** Large and small dischargers must respond.
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It 1s possible that a public water supply (desa11n1zat1on plant) Intake
could be contaminated by marine POTU discharges. Although such a possibility
may be remote, the applicant should verify that no public water supply
Intakes are located within 16 km (10 ml) of the discharge. If none exist
within 16 km (10 mi) of the discharge, no analyses are required. The name
of the agencies contacted and the person involved should be listed in the
application.
III.C.2. If the answer to Question III.C.I. is yes,
a. What is the location of the intake(s) (latitude and longi-
tude)?
b. Hill the modified discharge(s) prevent the use of intake(s)
for public water supply?
c. Hill the modified discharge(s) cause increased treatment
requirements for public water supply(s) to meet local, state,
and U.S. EPA drinking water standards?
***
Large and small dischargers must respond.
If the answer to Question III.C.I is affirmative, the location of the
desalinization plant should be shown on a nap with the discharge site
marked. The travel time to the intake should be estimated using the average
current speed. Using the methods discussed In this document, the applicant
should show that all water quality standards are met at the intake.
III.D. Biological Impact of Discharge fSuboart 125.62(c)l
POTW discharges can affect biological communities in the following ways:
• Modifications to structure of benthic communities (bottom
dwelling/feeding fishes and Invertebrates) caused by
accumulation of discharged solids on the seabed
81
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• Increases In phytoplankton or macroalgal growth due to
nutrient Inputs
• Reductions In phytopl ankton or macroalgal growth due to
turbidity Increases
• Reductions In dissolved oxygen due to phytoplankton blooms
and subsequent die-offs, leading to mass mortalities of fishes
or Invertebrates
• B1oaccumulat1on of toxic substances 1n marine organisms due to
direct contact with sediment, 1ngest1on of sediment, direct
uptake from effluent, or Ingestion of contaminated organisms
• Induction of diseases In marine organisms caused by contact
with contaminated sediments, Ingestion of contaminated
organisms, or exposure to effluent.
Host of these potential impacts are associated with discharged
particulate matter. The potential effects of discharged solids may be
compounded by the toxic substances adsorbed to these solIds. Hence, the
primary potential effects of sediment enrichment by organic particles and
sediment contamination by toxic substances are closely linked, and are
generally manifested in the same biotic groups. Discharged effluent solids
tend to accumulate near the sewage outfalls, and bottom-dwell Ing marine
organisms (e.g., benthic macroinvertebrates and bottom-feeding fishes) are
potentially affected by these accumulations because they live in or on the
sediments.
Additional environmental effects are associated with the discharge of
plant nutrients, which may result In eutrophication, especially in estuaries
or coastal embayments. Related impacts can include stimulation of toxic or
nuisance algal blooms. Such phytoplankton blooms may adversely affect
commercial and recreational fisheries because the decomposition of phyto-
82
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plankton after massive blooms can cause dissolved oxygen deficiencies and
associated fish or Invertebrate kills.
Biological assessments for Improved discharges, altered discharges, or
discharges Into stressed waters Involve predictive demonstrations of future
biological conditions near the outfall and elsewhere In the receiving water
body. These analyses may Involve establishing relationships between water
quality conditions and biological conditions and predicting future conditions
based on these relationships. Thus, biological assessments for Improved or
altered discharges Involve not only describing existing biological communi-
ties but also determining whether a BIP will exist beyond the ZID after
Improvements or alterations to the discharge.
To support a Section 301(h) modification, the applicant does not have
to show that conditions of each biological community at all points beyond
the ZID fall within the natural range of variation observed at the reference
sites. Rather, the applicant's assessment should concentrate on determining
the conditions of the following types of biological assemblages at control
sites and at the areas of potential Impact:
• Communities that are most susceptible to impacts from POTW
discharges
• Communities with aesthetic, recreational, or commercial
importance
• Communities with distributional patterns that enable
quantitative assessment with reasonable sampling effort and
resources.
Using this approach, applicants should be able to study the Important
communities that are expected to demonstrate discharge-related effects
while not wasting effort on studies with a limited potential for providing
meaningful results. Based on the review of existing Section 301(h)
applications, the major potential effects of POTW discharges are associated
83
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with benthic macroInvertebrates and demersal fishes. Because of their
distribution characteristics, both of these communities can be assessed
quantitatively with a reasonable level of sampling effort. Benthic
macrolnvertebrates are also the primary food Items for demersal fishes and
early-life stages of certain other fishes. Consequently, these two
communities are linked by a food web relationship, and severe Impacts on
benthic macrolnvertebrates may result 1n secondary Impacts to demersal or
other fishes.
Benthic macrolnvertebrates and demersal fishes are two Important groups
that typically warrant BIP demonstrations. However, it should not be
assumed that these are the only biological communities that should be
studied 1n all cases. The concept of a BIP Includes any and all biological
communities potentially affected by the discharge.
HI.D.I. Does (will) a balanced indigenous population of
shellfish, fish, and wildlife exist:
a. Immediately beyond the 21D of the current and modified
discharge(s)?
b. In all other areas beyond the ZID where marine life is
actually or potentially affected by the current and
modified dlscharge(s)?
*** Large and small dischargers must respond.
The purpose of the question 1s to determine whether unacceptable
biological Impacts occur or will occur beyond the ZIO. Effective demonstra-
tions that the modified discharge, either singly or In combination with
other discharges, does not contribute to adverse biological impacts include
comparisons of biological conditions and habitat characteristics among
stations or groups of stations. The applicant should demonstrate that
biological conditions and habitat characteristics do not differ substantially
among stations (or groups of stations) In ZID-boundary, nearfield, farfield,
and reference areas.
84
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The applicant should compare the ranges of biological characteristics
among the four specified areas where communities are to be assessed. If
differences that are attributable to the discharge are detected between
study areas (e.g., ZID boundary vs. reference), the applicant should assess
the spatial extent of those differences. In addition, the magnitude of the
effect should be characterized with regard to the relative deviation from
reference conditions (e.g., percent reduction In species richness), the
potential for 1ntertroph1c effects (e.g., reductions In fish food organisms),
and the potential for Involvement of recreationally or commercially
Important species.
Numerous variables may be used to describe and compare biological
communities (e.g., numbers of species; total abundances of organisms;
abundances of selected pollution-sensitive, pollution-tolerant, and op-
portunistic species). [See Tetra Tech (1987f) for further guidance on the
selection of biological Indices.] Physical characteristics of the receiving
environment that are often measured Include water column characteristics,
(e.g., depth, water temperature, salinity, nutrient concentrations, chloro-
phyll a concentrations) and substrate characteristics (e.g., bottom type and
composition). Information on the physical characteristics of the environment
may be used to Interpret the biological data and to determine whether the
discharge Is altering the physical or chemical characteristics of the
receiving environment.
Species vary in their sensitivities to pollutants, Including organic
enrichment. Changes in species composition and abundance begin to occur
when the mass emission rates of materials in a sewage discharge are suffi-
ciently high to affect the most sensitive species. As the abundances of
pollution-sensitive species decrease or are driven to zero, abundances of
opportunistic and pollution-tolerant species are typically enhanced. For
this reason, changes in the values of community variables (e.g., numbers of
species, total abundances, dominance) are often accompanied by changes in
the abundances of opportunistic and pollution-tolerant species. Additional
85
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guidance on the evaluation of biological communities is provided in Appen-
dix C.
Special Considerations for Small Dischargers
During the preparation of applications for original Section 301(h)
modified permits, many small applicants were able to respond to this question
without conducting field studies of biological communities 1n the vicinity
of the discharge. Those small applicants used existing Information to
demonstrate that the characteristics of the discharge and receiving
environment indicated a very low potential for adverse impacts. If an
applicant was not required to collect biological information during the
term of the existing permit, that applicant may continue to use other
available information to demonstrate that the characteristics of the
discharge and receiving environment indicate a very low potential for
adverse Impacts. Applicants are reminded, however, that such demonstrations
must consider the potential for adverse impacts of the discharge singly and
in combination with other discharges (1f any exist) [Subpart 125.57(a)(2)].
The following characteristics Indicate a low potential for impact:
• Location of the discharge in water depths greater than 10 m
(33 ft)
• Hydrographic conditions that result in low predicted solids
accumulation rates
• The absence of distinctive habitats of limited distribution
and the absence of fisheries in the vicinity of the outfall,
when such absences are not due to anthropogenic stresses
• The absence of known or suspected sources of toxic pollutants
and pesticides or low concentrations of these substances in
the effluent.
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Most small dischargers that previously demonstrated a low potential for
Impact should be able to do so again. They only need demonstrate that
characteristics of the discharge and receiving environment did not change
greatly during the term of the existing permit. Monitoring data collected
during the term of the original Section 301(h) modified permit should also
be useful for such demonstrations.
Some small dischargers may not be able to demonstrate a low potential
for Impacts because characteristics of the discharge or receiving environment
differ from those listed above. In some cases, the discharge or receiving
environment may not have exhibited the aforementioned characteristics at the
time the original application for a Section 301(h) modified permit was
prepared. In others, characteristics of the discharge or receiving en-
vironment may have changed, or additional information may now be available
that documents a greater potential for impact than was previously supposed.
For example, the composition of the discharge may have changed to include
toxic pollutants or pesticides from a new industrial source. Alternatively,
a fishery for a previously underutilized species may have developed in the
vicinity of the discharge, or research by local scientists may have dis-
covered that the habitat in the vicinity of the outfall is an important
nursery ground for a commercially harvested species of fish or shellfish.
When It is apparent for one or more reasons that the discharge or
receiving environment does not exhibit characteristics that would indicate a
low potential for Impacts, the Regions have the discretion to require that
an applicant perform a detailed assessment of biological conditions in the
vicinity of the outfall. The level of detail that would be expected in such
a demonstration would be comparable to that required by large dischargers.
In some cases, the applicant may have been required to monitor one or
more biological communities under the conditions of the existing Section
301(h) modified permit. The Region may require the applicant to analyze and
discuss those biological monitoring data in response to this question. When
biological monitoring data were not collected, but concern exists that the
modified discharge might cause adverse impacts to the biota, the Region may
87
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require the applicant to collect biological data 1n support of the ap-
plication for permit reIssuance. If the Region requires the collection of
additional data, the Region should consult with the applicant well in
advance of the .application deadline, thereby giving the applicant adequate
time to design and execute appropriate studies. Applicants required to
perform these field surveys should consult Tetra Tech (1982a, 1987a,c,f) for
guidance on the design and execution of those surveys. To ensure the
collection, of adequate, high quality data, the Region should work closely
with the applicant during all phases of the necessary studies.
III.D.2. Have distinctive habitats of United distribution been
Impacted adversely by the current discharge and will such habitats
be Impacted adversely by the modified discharge?
*** Large and small dischargers must respond.
If distinctive habitats are present In areas potentially Influenced by
the discharge, the applicant should provide Information that documents the
extent and condition of those habitats. The applicant should also provide a
detailed evaluation of available historical Information on the spatial
distribution of any distinctive habitats near the outfall and In nearby
control areas. Trends 1n spatial occurrence should be evaluated relative to
historical discharges by the applicant and relative to other water quality
or biological factors that may Influence the habitat.
If available, the applicant should Include documentation of any long-
term changes 1n the spatial extent or general health of the distinctive
habitat. Examples of such Information Include areal extent of kelp beds or
condition of algal cover on coral reefs. If historical changes In the
habitat have occurred, the applicant should attempt to relate those changes
to natural or pollution-related events. For example, severe storms may
damage coral reefs, and heavy pedestrian traffic can degrade rocky intertidal
communities.
-------
• Health-related factors [Including paralytic shellfish
poisoning (PSP), bacteriological contamination, and bioaccumu-
latlon of toxic substances]
• Economic or marketing considerations
• Resource protection closures
• Other regulatory closures.
If reasons for closures are due to tissue contamination, the applicant
should specify the contributing pollutant sources.
Many sources of Information are available to address the fish and
fishery concerns outlined above:
• Local anglers
• Public, Institutional, and agency libraries
• Academic Institutions (e.g., marine science, biology, zoology
departments; Sea Grant offices; cooperative fishery research
units)
• Local (e.g., conservation boards), state (e.g., fish and game
departments), and federal natural resource agencies and
affiliated laboratories (e.g., National Marine Fisheries
Service, U.S. F1sh and Wildlife Service)
• Regional fishery management councils (contact Information
available from National Marine Fisheries Service)
• County, state, and federal environmental protection and public
health agencies.
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Environmental protection and public health agencies should be contacted
to obtain Information on the health of fishes In the vicinity of an outfall.
These agencies monitor water quality and col 1 form bacteria concentrations In
shellfish as part of a national public health program. They will also
provide Information on PSP If It 1s known to occur In the geographic area.
Depending on the distribution of fishery resources and pollutant levels In
receiving waters, these agencies may also conduct laboratory studies on
toxic bloaccumulatlon In fish species harvested for human consumption. An
applicant should request all available Information concerning the region and
Immediate vicinity of the discharge, and, with the assistance of agency
personnel, attempt to determine the discharge's contribution to any observed
fish health problems. A conclusion by agency personnel that the discharge
Is not contributing to public health problems should be documented by the
applicant.
State departments of environmental protection or ecology are generally
responsible for recording occurrences of fish kills within state waters.
Typically, a report 1s filed by the departmental agent who Investigated the
kill, recording such Information as the severity of the Incident and its
probable causes. An applicant should request and review reports of relevant
fish kills and document whether the discharge has been Implicated in any of
these Incidents.
Most environmental protection and public health agencies do not
routinely assess the health status of fish unless a serious problem with
toxics bioaccumulation 1s suspected in species sought by commercial or
recreational fishermen. Sources of Information on fish disease or abnor-
malities Include academic Institutions or fisheries agencies, which may have
conducted fish surveys in the vicinity of an outfall.
A careful review of available Information should enable a small
applicant to characterize the local fish communities and fisheries without
an actual field survey, unless there Is sufficient evidence to Indicate that
the discharge has, or Is likely to, adversely impact important fish
resources.
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The applicant should evaluate any effects of the discharge with
emphasis on the physical, chemical, and biological conditions that occurred
within the distinctive habitats 1n the vicinity of the outfall during the
term of the existing 301(h) permit. The applicant's discussion should be
oriented towards an assessment of the potential for contact of the effluent
plume with any nearby distinctive habitats. In cases where a distinctive
habitat occurs near an outfall, the applicant can evaluate Impacts by
considering the following:
• Degree of Initial dilution
• Degree of farfleld dispersion
• Frequency and direction of waste transport
• Lack of prior appreciable harm.
The most effective demonstrations of Impacts (or the lack of Impacts)
Include comparisons of potentially Impacted areas with reference areas
beyond the Influence of the discharge. Experience with applications for
Section 301(h) modified permits has shown, however, that suitable reference
areas for distinctive habitats of limited distribution are often difficult to
find. The biota that characterize distinctive habitats often require
specific environmental conditions that occur dlscontinuously within the
blogeographlc zone, and often only 1n small areas. When a suitable ref-
erence area for a distinctive habitat of limited distribution does not
occur in the vicinity of the applicant's outfall, the applicant should
present (to the extent possible) detailed Information on the typical
physical, chemical, and biological characteristics of that distinctive
habitat within the blogeographlc zone. When suitable data are available,
applicant should assess potential Impacts to distinctive habitats of limited
distribution by using the graphical and mathematical tools discussed in
Appendix C.
89
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Special Considerations for Small Dischargers
When 1t appears that a small discharger 1s causing (or has the
potential to cause) Impacts to distinctive habitats of limited distri-
bution, the Region may require the applicant to perform a detailed assessment
of distinctive habitats 1n the vicinity of the discharge. Such a detailed
assessment would be comparable to that required of large dischargers, as
described above. Therefore, guidance provided above and under Questions
II.C.2 and III.D.I of this questionnaire Is relevant to the performance of
such detailed demonstrations. The Region should notify the applicant well
1n advance of the application deadline of the need for additional data on
distinctive habitats, so as to give the applicant adequate time to design
and execute appropriate studies. Moreover, the Region should work closely
with the applicant during all phases of the studies to ensure that adequate,
high quality data are collected.
III.0.3. Have commercial or recreational fisheries been impacted
adversely by the current discharge (e.g., warnings, restrictions,
closures, or mass mortalities) or will they be impacted adversely
by the modified discharge?
*** Large and small dischargers must respond.
If fisheries resources are present 1n areas potentially Influenced by
the discharge, the applicant should assess the effects of the discharge on
these resources by analyzing catch records, market acceptability, contam-
ination of tissues by toxic substances, prevalence of disease, and harvest
warnings/closures.
The applicant should also determine whether any potential fishery
resources remain unharvested in the area because of warnings or closures. If
unharvested resources are Identified, the applicant should Indicate the
reasons why these resources are not utilized, such as the following:
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III.0.4. Does the current or modified discharge cause the
following within or beyond the ZID: [Subpart 125.62(c)(3)j
a. Mass mortality of fishes or invertebrates due to oxygen
depletion, high concentrations of toxics, or other
conditions?
b. An Increased Incidence of disease in marine organisms?
c. An abnormal body burden of any toxic material in marine
organisms?
d. Any other extreme, adverse biological Impacts?
*** Only large dischargers must respond.
This question requires the assessment of several specific potential
Impacts of POTU discharges. The applicant should review and summarize
available Information on occurrences of mass mortalities of marine organisms
1n the receiving water environment. The suspected causes of mass mortalities
should be evaluated to determine whether any of these events could have
resulted from the discharge. Evaluation of actual or potential mass
mortalities Is especially Important for applicants with discharges Into
estuaries or enclosed embayments. Dissolved oxygen deficiencies in
environments with limited flushing characteristics may result from BOD
Inputs or algal decomposition following bloom conditions. Evaluation of
disease incidence or tissue contamination In marine organisms should be
conducted by spatial comparisons of communities near the discharge (ZID and
ZID boundary) with those in control areas (see Tetra Tech 1985a-d; 1987d).
Many studies have suggested that a relationship exists between the
Incidence of disease In marine organisms and contact with POTU effluents.
These diseases Include exophthalmia in spotfln croakers (Roncador stearnsil)
and white seabass (Cynoscion nobilis), Up papilloma in white croakers
(Genyonemus lineatus), and discoloration In halibut (Hacrostomus pacificus)
(Mearns and Sherwood 1974; McDermott-Ehrlich et al. 1977). Bloaccumulation
of chlorinated hydrocarbons and trace metals has been reported in marine
organisms collected near sewage outfalls off southern California. Affected
93
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species Included the Dover sole (Hlcrostonus padflcus), rock crab-(Cancer
anthonyl), mussel (Hytllus californlanus), and rock scallop (H1 twites
multirugosus) (McOermott et al. 1976; Young et al. 1976a; McDermott-Ehrlich
et al. 1978; and Young et al. 1978;).
The discharge of sewage effluents containing toxic substances can
result In bloaccumulatlon, especially 1n areas of organic sediment accumula-
tion. Toxic heavy metals and persistent synthetic organic compounds
generally have the highest potential for bloaccumulatlon 1n marine organisms.
The Identification of substantial concentrations of such substances in the
plant effluent in combination with either of the following receiving water
characteristics Indicates the need for evaluation of bloaccumulatlon:
• Evidence of effluent transport toward areas used for
shellfish harvesting
• Significant occurrence of Important recreational or commercial
species and evidence of potential sediment accumulation near
the outfall.
The potential for bloaccumulatlon may be evaluated by the applicant by
comparing the concentrations of toxic substances after initial dilution with
U.S. EPA saltwater criteria. Two types of information are required for this
comparison:
1. Concentration of the pollutant in the discharged effluent
2. Critical Initial dilution.
The value of (1) divided by (2) should then be compared with the
available criterion.
Most of the toxic substances with a high bloaccumulatlon potential will
be associated with organic particulates In the discharged effluent. Thus,
in determining bioaccumulation potential, it is important not only to
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evaluate concentrations of these substances 1n the effluent and .In the
receiving water following Initial dilution, but also to examine sediment
accumulation patterns. Substantial bloaccumulatlon Is possible even when
water quality criteria are met because of localized accumulation of
contaminated sediments. Alternatively, the applicant may be able to
demonstrate that bloaccumulatlon 1s not a serious problem even though toxic
substances are present 1n the effluent, by providing Information that
demonstrates the following:
• Adequate Initial dilution
• Sufficient circulation to prevent localized accumulation of
solids or trapping of effluent plumes.
The degree to which the applicant may be required to assess bloaccumula-
tlon using field surveys 1s also dependent upon the kinds of organisms
present. Several Investigators have demonstrated the ability of bivalve
molluscs and crustaceans to accumulate metals and organic substances near
sewage discharges (Young et al. 1976b, 1978). Studies at some of the same
sites and at other contaminated areas have indicated that demersal marine
fishes do not generally accumulate metals in muscle tissue (with the
exception of organic mercury) but accumulate organic substances such as high
molecular weight chlorinated hydrocarbons (McDermott-Ehrlich et al. 1978;
McOermott et al. 1976). Thus, in the case where an effluent contains
substantial quantities of heavy metals, the potential data requirements
would be greater If shellfish resources occurred In potentially impacted
areas than if fishes constituted the only locally important resources.
Furthermore, the potential for bloaccumulatlon would be less if fishes with
only transitory plume exposure were present (e.g., pelagic or migratory
species) than if demersal species dominated in areas of sediment deposition.
Sessile filter-feeding molluscs . that are highly susceptible to
bioaccumulation, and that may also be important commercial or recreational
resources, are generally found in nearshore habitats, especially in
embayments or estuaries. If an applicant can demonstrate that shellfish
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resources do not occur In the outfall vicinity or in other areas potentially
Impacted by the discharge, or that effluent dispersion Is adequate, tissue
analyses of Indigenous biota may not be required to demonstrate the absence
of adverse bloaccumulatlon. Discharges located 1n areas with limited
dispersion, such as estuaries or embayroents, may cause contamination of
local shellfish resources. In such cases, the applicant should conduct
analyses of tissue concentrations of toxic substances Identified In the
plant effluent. Examples of species that nay be appropriate for tissue
analyses Include oysters, clams, mussels, crabs, or lobsters.
An additional situation which will Influence the requirement for direct
assessment of bloaccumulatlon Is where other pollutant sources cause
observed contamination of fish or shellfish resources. This would especially
pertain to cases of nearby fishery closures or harvesting restrictions due
to pollutant Inputs. In such cases, it 1s important for the applicant to
demonstrate that Its discharge 1s not contributing to the existing contami-
nation. This demonstration can be accomplished by the previously described
analyses of effluent pollutant concentrations and initial dilutions, or by
evaluation of existing information on the spatial patterns of pollutant
concentrations in organisms or sediments. It may be necessary for the
applicant to conduct tissue or sediment analyses if effluent and dilution
analyses indicate the potential for bloaccumulatlon and if sufficient data
are not available to determine pollutant sources in areas of existing
contamination of fishery resources.
777.0.5. for discharges into saline estuarine waters: [Subpart
125.62(c)(4)]
a. Does or will the current or modified discharge cause
substantial differences in the benthic population within
the ZID and beyond the ZID?
6. Does or will the current or modified discharge interfere
with migratory pathways within the ZID?
c. Does or will the current or modified discharge result in
bioaccumulation of toxic pollutants or pesticides at
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levels which exert adverse effects on the biota within
the 210?
Ho section 301(h) modified penult shall be used where the
discharge enters into stressed saline estuarine waters as stated
1n Subpart 12S.59(b)(4).
*** Large and small dischargers must respond.
The Water Quality Act of 1987 prohibits the Issuance of Section 301(h)
modified permits for discharges Into saline estuaries with the following
characteristics:
• The estuary does not support a balanced Indigenous population
of shellfish, fish, and wildlife
• The estuary does not allow for recreational activities
• The estuary exhibits ambient water quality characteristics
that are not adequate to protect public water supplies;
protect shellfish, fish, and wildlife; allow for recreational
activities; and comply with standards that assure and protect
such uses.
A Section 301(h) modified permit may not be Issued If the receiving waters
exhibit any of the foregoing conditions, regardless of the causes of any of
those conditions.
Estuaries are generally more productive than coastal areas, and are
often more sensitive to pollutants. They also serve as spawning and
nursery grounds for many Invertebrates and fishes. Moreover, the flushing
characteristics of estuaries may be considerably less than those of open
coastal areas, especially during periods of reduced freshwater Input. Thus,
for a given discharge size, there 1s generally a higher potential Impact In
estuaries than 1n open coastal environments.
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Additional Information 1s required for saline estuarlne discharges.
U.S. EPA regulations [Subpart 125.62(c)(4)] require applicants to demonstrate
that no substantial differences exist between berth1c communities within the
ZIO and beyond the ZID. Hence, applicants discharging Into saline estuaries
must compare benthlc communities within the ZID and beyond the ZID boundary
with benthlc communities at reference sites.
The applicant should also assess the degree to which the discharge
could Interfere with migratory pathways within the ZID. In conducting this
assessment, the applicant may calculate the proportion of the cross sectional
area of the estuary that Is Influenced by the ZID. The potential for
migratory Interference may then be evaluated by considering the relative
size and characteristics of the discharge-affected area and its location in
the estuary with respect to known migratory pathways.
Applicants with saline estuarlne discharges must also assess the
bioaccumulatlon of toxic substances within the ZID. If elevated or
Increasing concentrations of toxic substances are found in fish or shellfish,
the applicant should assess the potential for adverse Impacts such as
restrictions on human use (e.g., FDA Action Levels), Induction of disease, or
Interference with fish and shellfish growth or reproduction (see Tetra Tech
1985a-d; 1987d).
Special Considerations for Small Dischargers
When there is reasonable concern that one or more of the foregoing
conditions has come Into existence during the term of the existing Sec-
tion 30I(h) modified permit, the Regions should require small applicants with
discharges Into saline estuaries to demonstrate successfully that none of
the foregoing conditions exist. To do so, small applicants may be required
to perform a detailed biological survey similar to that required of large
dischargers. Small applicants are advised to consult the Information
provided under Questions II.C.I and III.D.I (above) and in Section III.F for
guidance on the design and execution of detailed biological surveys. The
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Regions should notify applicants well In advance of the application deadline
•
If a demonstration Is required to document the absence of stressed conditions
1n the receiving environment. - ,
III.D.6. For Improved discharges, will the proposed improved
discharge(s) comply with the requirements of Subparts 125.62(a)
through 125.62(d)? [Subpart 125.62(e)J
*** large and small dischargers must respond.
U.S. EPA regulations require applicants who propose discharge Improve-
ments to demonstrate that the Improvements will result 1n compliance with
Subparts 125.62(a) through 125.62(d). This demonstration might be ac-
complished by comparing conditions at the outfall location with conditions
near discharges that are similar to the proposed Improved discharge.
Assuming that there 1s a basic similarity In Indigenous biota of the
receiving environment, such a comparison may be sufficient to predict
protection of a BIP. Applicants may also conduct predictive analyses of
effluent dispersion and seabed accumulation of sol Ids following discharge
Improvements.
Applicants whose discharge Improvement plans Include outfall relocation
should describe existing biological conditions at both the proposed and
existing outfall sites. Those applicants are also to predict future
biological conditions at the proposed site following relocation of the
outfall. Such predictions might be conducted by comparisons with other
discharges that are similar to the relocated discharge. Discharges used
for such comparisons should be located In receiving environments similar to
the applicant's.
III.D.7. For altered dlscharge(s), will the altered dlscharge(s)
comply with the requirements of Subparts 125.62(a) through
125.62(d)? [Subpart 125.62(e)J
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Large and small dischargers oust respond.
Applicants that request modifications for altered discharges may use
predictive methods similar to those described for Improved discharges.
However, such applicants must demonstrate that the Increased pollutant
loading that will result from population growth or Industrial growth within
the service area will still enable compliance with Subpart 126.62(a)-(d).
These predictions of compliance with 301(h) criteria during the 5-yr permit
term may be technically difficult, and may require extensive analyses.
III.D.8. If your current discharge Is to stressed ocean waters,
- does or will your current or modified discharge: [Subpart
125.62(f)J
a. Contribute to, increase, or perpetuate such stressed
condition?
6. Contribute to further degradation of the biota or water
quality if the level of human perturbation from other
sources increases?
c. Retard the recovery of the biota or water quality if
human perturbation from other sources decreases?
*** Large and small dischargers must respond.
When it appears that art applicant's receiving waters are or may be
stressed, the Region may require the applicant to demonstrate the presence or
absence of stressed conditions. If stressed conditions exit, the areal
extent and magnitude of those stresses should be documented. Because
stressed water determinations are largely based on biological conditions in
the receiving environment, applicants may be required by the Regions to
perform detailed biological surveys. Applicants required to perform
detailed biological surveys for the purpose of determining whether stressed
waters exist 1n the receiving environment should consult Section III.F of
this document and guidance documents cited therein for information on the
design and execution of those surveys. The Regions should notify applicants
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well 1n advance of the application deadline If surveys of the b\ota are
required to determine whether stressed conditions exist 1n the receiving
environment. Moreover, the Regions should work closely with applicants
during all phases of the required studies to ensure the collection of
adequate, high quality data.
*7IJ.£. Impacts of Discharge on Recreational Activities fSuboart
125.62(d)l
It Is necessary to ensure that a 301(h) modified discharge will 1) meet
'water quality standards relevant to recreational activities beyond the ZID,
and 2) will not cause legal restrictions on activities that would be lifted
or modified by upgrading the applicant's POTW to secondary treatment.
III.E.I. Describe the existing or potential recreational
activities likely to be affected by the modified discharge(s)
beyond the zone of initial dilution.
*** Large and small dischargers must respond.
The Impact of POTW discharges on recreational activities must be
assessed. Recreational fisheries are considered 1n the biological evaluation
section. Other activities Involving contact with water may be affected by
mlcroblal contamination. For recreational Impact assessment, dispersion and
transport of the effluent needs to be considered in conjunction with the
applicant's disinfection procedures.
All recreational activities currently occurring within the bay, estuary,
or an 8-km radius of the outfall should be identified (e.g., swimming,
boating, fishing, shellfishing, underwater diving, picnicking, other beach
activities). Any additional potential future recreational activities should
also be Identified (e.g., new ports,, boat harbors). A map should be
provided that indicates the location of existing activities, along with the
location of the existing or proposed outfall. Qualitative or, whenever
possible, quantitative Information should be provided that indicates the
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extent of the existing activities. This could Include the number of boats
or boat slips In the area, species of fish and shellfish recreatlonally
harvested, size of catch, and number of beach user days.
III.E.2. Hhat are the existing and potential Impacts of the
modified dlscharge(s) on recreational activities? Your answer
should Include, but not be Halted to, a discussion of fecal
coUform bacteria.
*** Large and small dischargers must respond.
Water quality standards for protecting recreational uses, particularly
coUform bacteria or enterococcl standards, should be provided. Water
classifications within 8 km of the discharge should be Indicated. The
schedule and frequency of chlorination should be established. To confirm
compliance with standards relevant to recreational activities, any required
coUform or enterococcl bacteria monitoring data for the effluent, at the
ZID boundary, and on the adjacent shoreline should be submitted. As noted
1n Section III.F.2, bacteriological sampling should be limited to the night
or early morning hours. If shoreline areas are not normally monitored,
sampling should occur on the shore near popular water-activity areas. If
noncompl 1 ance with coUform bacteria standards Is noted, an explanation and
corrective measures should be provided. Other sources of coUform bacteria
present In the area that could be contributing to the problem should be
Identified.
IJI.E.3. Are there any Federal, State, or local restrictions on
recreational activities in the vicinity of the modified dischar-
ge(s)? If yes, describe the restrictions and provide citations to
available references.
*** Large and small dischargers must respond.
Any federal, state, or local restrictions or closures relating to the
discharge and recreational activities should be identified. The nature of
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restrictions, the date Implemented, and the agency responsible (e.g., state
department of health) should be Indicated.
III.£.4. If recreational restrictions exist, would such restric-
tions be lifted or modified if you were discharging a secondary
treatment effluent?
*** Large and small dischargers must respond.
If restrictions are In place, the relation of the restriction to the
current or modified discharge quantity and quality should be established. If
an Improvement 1n the discharge quality would modify or eliminate the
restriction on recreational activities, this should be Indicated. In all
such events, 1t should be determined whether secondary treatment would
Improve the discharge sufficiently to allow the restriction to be modified.
III.F. Establishment of a Monitoring Program fSuboart 125.631
Establishment of a monitoring program for applicants granted Section
301(h) modified discharge permits Is Important to evaluate the impact of the
modified discharge on selected marine biological communities, to demonstrate
continued compliance with applicable water quality standards, and to monitor
effectiveness of the urban pretreatment and toxics control programs. Only
those scientific Investigations that are necessary to study the effects of
the proposed discharge should be Included in the scope of the monitoring
program [Subpart 125.63(a)(l)(i)(B)]. Unless special circumstances exist
(e.g., the presence of distinctive habitats, high mass emission rates of
toxic substances), monitoring programs for small dischargers are typically
much less comprehensive than those for large discharges.
The monitoring program consists of three parts: biological, water
quality, and effluent. Although each .of these parts involves sampling at
different locations and for different variables, they should not be
considered as Independent activities, but as an integrated study. In this
manner, the applicant will be able to meet specific objectives of each part
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of the study while also conducting a meaningful assessment of Impacts of the
discharge. Moreover, as predictable relationships are established among the
biological, water quality, and effluent monitoring variables, It should be
possible to delete certain elements of the field monitoring studies.
The continued assessment of marine biota as part of the monitoring
program Involves the same type of comparative strategy as is required for a
BIP demonstration in the application. The characteristics of selected
marine communities in the discharge vicinity are compared with biological
characteristics at reference areas. Hence, a primary objective of the
biological monitoring program 1s to evaluate continued compliance with the
BIP requirements. This demonstration can be accomplished by conducting
periodic (e.g., quarterly) seasonal surveys of biological communities.
Biological communities selected for study in the monitoring program
should Include those communities that are most likely affected by the
discharge. As 1s the case for BIP demonstrations in the original appli-
cation, the monitoring program should address any biological effects in
terms of spatial extent, magnitude, potential for secondary impacts, and
potential for involvement of commercial or recreational species. All of
these factors will be Important In determining whether or not detectable
differences in biological characteristics are adverse.
Bioaccumulatlon determinations and sediment sampling are used to
evaluate biological effects of toxic substances in the effluent. The
results of these studies can Indicate the potential for adverse effects on
human health, especially if recreationally or commercially important
fishery resources occurred in the outfall vicinity. These results may also
be used to determine the need for additional (or fewer) analyses of toxic
substances in sediments or in organisms exposed to the diluted effluent.
The water quality monitoring program Is intended to evaluate compliance
with applicable water quality standards and criteria, and to measure the
presence of toxic substances. An additional objective of the water quality
monitoring program is to provide information that will supplement the
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biological monitoring program, In particular to assist In the Interpre-
tation of observed biological differences.
Monitoring POTW effluent 1s Important for providing supplementary
Information for both the water quality and biological programs. Effluent
monitoring data are also used for demonstrating continued compliance with
the modified permit effluent limitations and as a data source for permit
renewal applications.
III.F.I. Describe the biological, water quality, and effluent
monitoring programs which you propose to meet the criteria of
Part 125.63. Only those scientific investigations that are
necessary to study the effects of the proposed discharge should be
included in the scope of the monitoring program [Subpart 125.63(a)
***
Large and small dischargers must respond.
The extent of the monitoring program required as part of a Section
301(h) variance will depend upon the characteristics of the discharge and
the receiving environment. Monitoring of the effluent and receiving water
may also be required as part of the applicant's existing NPDES permit or to
meet state regulations. The applicant's proposed monitoring program must be
submitted with the Section 301(h) application.
Detailed guidance on the design of Section 301(h) monitoring programs
is provided 1n Design of 301(h) Monitoring Programs for Municipal Uastewater
Discharges to Marine Water (Tetra Tech 1982a) and Framework for 301(h)
Monitoring Program (Tetra Tech 1987e). Although some technical Information
(primarily literature citations, analytical protocols, and legal citations
and requirements) provided in Tetra Tech (1982a) has been superceded, most
of the information is still valid and applicable to the design of 301(h)
monitoring programs. More recent documents (e.g., Tetra Tech 1985e, 1986,
1987c, 1987e) include the addition of recent literature citations, updated
analytical protocols, and updated legal citations and requirements. The
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updated Information 1n these more recent documents, together with the
earlier guidance provided by Tetra Tech (1982a, 1987e), 1s sufficient to
design and Implement an effective monitoring program. Applicants are
referred to the following documents for additional or updated guidance on
specific topics relevant to the design and execution of 301(h) monitoring
programs:
• Tetra Tech (1987a, 1988) for Information on positioning
methods In nearshore marine and estuarine waters
• Tetra Tech (1985c,d,e, 1986) for information on analytical
methods
• Tetra Tech (1987c) for Information on quality assurance/
quality control procedures for field and laboratory methods
• Tetra Tech (1985a,b,c,d, 1987d) for Information on bio-
accumulation monitoring studies
• Tetra Tech (1987b) for Information on fish liver pathology
monitoring studies.
Biological Monitoring
The applicant's biological monitoring program must Include the
following elements to the extent practicable:
1. Periodic surveys of control sites and biological communities
most likely to be affected by the discharge
2. Periodic bloaccumulatlon studies and examination of possible
adverse effects of effluent-related toxic substances
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3. Periodic sampling of sediments
4. Periodic assessment of commercial or recreational fisheries
(If present).
Small applicants are not subject to Items 2 through 4 Immediately above If
they discharge at depths greater than 10 m, and If they demonstrate through
a suspended sol Ids deposition analysis that there will be negligible seabed
accumulation In the vicinity of the modified discharge.
The objectives of the biological monitoring program are to evaluate the
Impact of the modified discharge and to demonstrate compliance with Section
301(h) biological requirements. Thus, the biological monitoring program
must enable the same spatial comparisons (I.e., ZID, ZID boundary, discharge
Impact area, and control) as are required for demonstration of a BIP.
The applicant's monitoring program should Include only those study
elements that are practicable and appropriate 1n the receiving water
environment. When the applicant considers that one or more of the afore-
mentioned study elements 1s not practicable, a justification for the proposed
deletion from the monitoring program should be provided. Examples of
situations 1n which reductions in the frequency or extent of biological
surveys would be reasonable might include conditions of high current speeds
or adverse climatic periods (sampling not practical) and periods of low
biological variability or extremely low productivity (sampling not appro-
priate).
Monitoring program specifications supplied by the applicant must
include the following Information:
• Biological groups to be sampled
• Sampling methods
• Station locations
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• Sampling schedules
• Preservation techniques
• Analytical techniques
• Quality assurance/quality control procedures
• Statistical analyses
• Taxonomlc sources.
The three types of sampling stations that should generally be Included
1n the periodic biological surveys to the extent practicable are located as
follows:
• In the vicinity of the ZID
• In other areas of potential discharge Impact
• In control (I.e., reference) areas.
Monitoring at sites Intermediate between control and outfall locations may
be necessary, especially for large discharges where definition of the
spatial extent of biological effects is an important consideration.
Additional station requirements would also be associated with discharges
into estuaries (within-ZID station), into stressed waters, or in situations
where other pollutant sources potentially affect biological communities near
the discharge. For modified discharges involving outfall relocation,
monitoring must be conducted at the existing discharge site until cessation
of that discharge, and at the relocation site.
Selection of control stations is one of the more important aspects of
monitoring program design, as BIP comparisons will rely on data from these
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sites. Control statlon(s) should be located in areas not Influenced by the
applicant's previous or existing discharge or other pollutant sources.
Sediment characteristics at the control station(s) should be similar to those
expected to occur naturally 1n the vicinity of the discharge. Discharge and
control stations should be located at similar water depths.
B1oaccumulat1on studies are to be Included in the monitoring program
to evaluate the potential adverse effects of toxic substances. In situ
bloassays may be needed on a case-by-case basis. Caged specimens of
bivalve molluscs (e.g., Mytllus edulls or H. californianus) are recommended
as test organisms for In situ bloassays. Exposures should be conducted in
the discharge vicinity and at an appropriate reference site. Additional
exposure sites may be necessary for Urge dischargers, especially in
situations where other pollutant sources contribute toxic substances to the
receiving water body. Only those toxic pollutants and pesticides Identified
in the applicant's discharge need to be measured in the exposed organisms.
The monitoring program must also include sediment sampling for toxic
substances in the vicinity of the discharge, in other areas of expected
solids accumulation, and at appropriate reference sites. VHthin-ZID
sampling should be undertaken where practicable. The sediment sampling is
Intended to provide an indication of the toxics accumulation within
sediments near the discharge and the associated contamination potential. If
elevated or Increasing concentrations of toxic substances are detected, the
applicant must also analyze tissue concentrations of toxic substances in
Indigenous organisms to determine whether adverse bioaccumulation is occur-
ring. Recommended organisms for such analyses Include demersal fishes
(e.g., flounder or sole), epibenthic megainvertebrates (e.g., crabs or lob-
ster) or sessile filter-feeding organisms (e.g., clams, mussels, or oysters).
•
Sediment samples should also be analyzed for characteristics that
would support the water quality and biological surveys. These variables
should include particle size distribution and total volatile solids. Other
variables such as 6005, sulfides, and total organic carbon, are also useful
and may be required by some states.
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If recreational or commercial fisheries are present In areas potentially
affected by the discharge, the applicant must also periodically assess those
fisheries. The kinds of evaluations conducted will depend on the nature of
the local fisheries and on the level of detail in available fisheries data.
These evaluations must reflect an understanding of the potential Impacts of
the discharge on the fisheries. Sources of Information used to determine
the productivity and status of fisheries Include state resource agencies,
voluntary logbooks, Interviews, and field observations. The periodic and
level of effort of fishery surveys will depend upon the size and location of
the discharge, concentrations of toxic substances In the effluent, species
harvested, and the Importance of the commercial or recreational fishery.
Water Quality Monitoring
The objectives of the water quality monitoring program are to provide
data for determining compliance with applicable water quality standards and
criteria, to measure the presence of toxics identified or expected in the
effluent, and to assist in the evaluation of biological data.
The water quality measurements usually required Include dissolved
oxygen, BODs, suspended sol Ids, pH, temperature, salinity, and light
transmittance. Light transmittance standards may be specified In terms of
turbidity, Secchi disc depth, extinction coefficient, or percent light
transmittance. With the exception of Secchi disc depth, water column
profiles should be determined for these variables. However, because the
Secchi disc provides cumulative data on water transparency measured from the
surface down to the depth at which it disappears from sight, the Secchi disc
should not be used to detect the effect of a submerged plume on light
transmittance.
Other variables that may be required include nitrogen (nitrate, nitrite,
total Kjeldahl nitrogen, and ammonia), total and reactive phosphorus, toxic
substances identified in the effluent, chlorophyll a, floating participates,
color, settleable solids, surface oil and grease, total and fecal coliform
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bacteria, and enterococd bacteria. Samples for these variables should be
collected 1.0 n (3.3 ft) below the water surface, at mid-depth, and 1.0 m
(3.3 ft) above the bottom. In deep water, sampling at additional water
column depths may be required. The applicant's monitoring program should
specify the variables for which profiles are to be taken along with the
sampling Interval.
For. existing discharges, stations should be located in the following
areas:
• ZID boundaries (both upcurrent and downcurrent)
• Control (I.e., background) stations along the primary axis of
the longshore component of the current (both upcurrent and
downcurrent)
• Intermediate upcurrent stations located between the ZIO
boundary and the upcurrent control station
• Potential Impact areas (e.g., In the nearshore zone and
close to areas with distinctive habitats).
The applicant should use Information on local currents and wastefield
dispersion patterns when selecting sampling station locations In potentially
impacted areas. Sampling stations located at the ZID boundary, control
stations, and Intermediate upcurrent stations should be in approximately the
same depth of water. Control stations should be located in areas not
influenced by the discharge. Intermediate upcurrent stations should be
selected to represent the approximate residual wastefield concentrations
upcurrent of the location, thereby accounting for potential recirculation of
previously discharged effluent (by reversing tidal currents, upwelling, or
stagnant net circulation). Data should be collected at the intermediate and
ZID stations at least twice daily (e.g., high and low slack tides), to
evaluate short-term conditions. The duration of the longshore current in
relation to the time of sampling is an important factor in determining
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whether the Intermediate upcurrent stations are representative of persistent
conditions or of only a temporary plume reversal . For discharges Involving
outfall relocation, monitoring stations must be located at the current
discharge site until cessation of the discharge, and at the relocation site.
For all cases, the applicant should Include a chart showing the
location of the outfall, the shoreline, any distinctive habitats, and all
sampling stations. The latitude, longitude, and depths of the stations
should be specified.
Sampling frequencies should be selected to comply with state require-
ments and to provide data for critical periods. In most cases, quarterly
surveys that Include the critical periods (e.g., time of maximum stratifica-
tion) should meet state requirements. More frequent sampling (e.g., for
coliform bacteria) in swimming or shellfish harvesting areas may be required
by some states. The analytical methods and quality control /quality assurance
procedures should be described (see Section III.F.2 for additional guidance).
Effluent Monitoring
The major objectives of treatment plant monitoring are to provide data
for determining compliance with permit effluent limitations and state
requirements, to measure the effectiveness of the toxic substance control
program, and to relate discharge characteristics to the receiving water
biological and water quality conditions. In add 111 on, influent and effluent
monitoring provide data for assessment of treatment plant performance, which
may be required to meet modified discharge permit conditions.
Variables that should be measured in the effluent are flow,
suspended solids, pH, dissolved oxygen, and the toxic pollutants and
pesticides present or likely to be present in the discharge. The toxic
pollutants and pesticides that should be measured are specified in Subparts
125.58(z) and (o) of the Section 301(h) regulations. Additional variables,
which may be required by other permit conditions, include grease and oil,
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settleable solids, nutrients, total and fecal col 1 form bacteria, and
temperature.
Influent, samples for conventional pollutant and nutrient analyses, 1f
required, should be collected just downstream of any coarse screens or grit
chambers. Effluent samples should be collected downstream of any chlor1 na-
tion or disinfection units. Effluent samples to be analyzed for toxic
substances should be collected just upstream of the outfall. In general,
grab samples should be collected for pH and total and fecal coll form
bacteria. For the other conventional pollutants (e.g., suspended solids),
24-h flow composite samples are recommended.
III.F.2. Describe the sampling techniques, schedules, and
locations, analytical techniques, quality control, and verification
procedures to be used.
*** Large and small dischargers must respond.
The following Information must be provided for all portions of the
proposed monitoring program:
• Variables to be measured
• Sampling methods
• Sampling schedule
• Sampling locations
• Analytical techniques
• Quality control and verification procedures.
Guidance on the above subjects is provided In the documents listed In
Section III.F.I. Current U.S. EPA-approved methods should be used for all
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variables. Additional guidance on navigational requirements Is provided In
Appendix D.
III.F.3. Describe the personnel and financial resources available
to implement the monitoring programs upon issuance of a modified
permit and to carry it out for the life of the modified permit.
_ t
*** Large and small dischargers must respond.
The applicant must provide Information on available personnel,
facilities, and financial resources to show that the proposed monitoring
program can be Implemented and continued for the tern of the modified
discharge permit if a Section 301(h) variance Is granted. The applicant
should review state monitoring requirements to ensure that the proposed
program meets those requirements.
III.G. Effect of Discharge on Other Point and Honooint Sources Wart
125.641
III.G.I. Does (will) your modified discharge(s) cause additional
treatment or control requirements for any other point or nonpoint
pollution source(s)?
*** Large and small dischargers must respond.
The Section 301(h) regulations require an analysis of whether a
decreased treatment level at the applicant's discharge would require other
pollution sources in the vicinity to Increase their treatment levels or
apply other additional controls. For open coastal waters, a list of
discharges within the anticipated impact area of the applicant's modified
discharge should be provided. The subsequent dilution at each outfall can
be estimated using Table B-5 in Chapter.B-IV of Appendix B of this document.
The total dilution is the product of the initial dilution and the subsequent
dilution. If the effect of the applicant's discharge is small at other
sources, further analysis may not be needed. Otherwise, an analysis of
114
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compliance with water quality standards at the other discharger sites is
•
appropriate for determining the effects of the applicant's discharge at
these sites. For most small POTW discharges, the effects on other sources
•should be negligible.
In estuaries where outfalls are close together, effects on other
sources are possible. The approach outlined above can be used to estimate
total dilution at the other outfalls.
III.G.2. Provide the determination required by Subpart 125.64(b)
or, if the determination has not yet been received, a copy of a
letter to the appropriate agency(s) requesting the required
determination.
*** Large and small dischargers must respond.
The applicant must provide a copy of a determination from the state or
Interstate agencies that are authorized to establish wasteload allocations
Indicating whether the proposed discharge will result In the Imposition of
additional pollution control requirements on any other point or nonpoint
sources. This determination must also explain the basis of the conclusions.
If the required determination has not been received when the application
1s submitted to U.S. EPA, the applicant should Include copies of the request
letters to the appropriate agencies. When the determination Is made, a copy
of the determination letter should be forwarded to U.S. EPA.
III.H. Toxics Control Program fPart 125.661
The toxics control program is designed to identify and assure control
of toxic pollutants and pesticides discharged to the POTU. The Section
301(h) toxic control regulations require both industrial and nonindustrial
source control programs. However, the control of industrial sources is
addressed separately by pretreatment program regulations [Subpart 403.8(d)]
that require all industrial pretreatment programs to have been approved by 1
115
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July 1983. Applicants must nonetheless adhere to the Section 403 program
requirements and compliance schedules.
U.S. EPA's Section 301(h) toxics control program regulations apply to
all applicants. However, small applicants who certify that there are no
known or suspected sources of toxic pollutants and pesticides to the POTVf are
relieved of most of the cost burden for toxics control program development.
111.H.I. a. Do you have any known or suspected Industrial
sources of toxic pollutants or pesticides?
b. If no, provide the certification required by Subpart
125.66(a)(2).
c. If yes, provide the results of wet- and dry-weather effluent
analyses for toxic pollutants and pesticides.
d. Provide an analysis of known or suspected industrial sources
of toxic pollutants and pesticides identified in III.H.l.c above.
*** Large dischargers must respond to parts a through d.
*** Small dischargers must respond to parts a and b in full, and to parts c
and d to the extent practicable.
Toxic pollutants and pesticides are defined in Subparts 125.58(aa) and
125.58(p), respectively, and include those substances listed in Table 2.
Marine water quality criteria are summarized in Table 3. Guidance on
sampling and analytical methods 1s found in Tetra Tech (1982a, 1987c,e) and
40 CFR Part 136.
If there are no known or suspected industrial sources of toxic
pollutants or pesticides, the applicant must certify this fact, based on the
results of an industrial user survey. This survey must be conducted as
described in 40 CFR 403.8(f)(2).
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TABLE 2. TOXIC POLLUTANTS AND PESTICIDES
AS DEFINED IN SECTION 125.58 (aa) and (p)
Demeton
Guthion
Malathion
Pesticides
Methoxychlor
Mi rex .
Parathion
Toxic Pollutants
1. Acenaphthene
2. Acrolein
3. Acrylonitrile
4. Aldrin/dieldrin
5. Antimony and compounds3
6. Arsenic and compounds
7. Asbestos
8. Benzene
9. Benzidine
10. Beryllium and compounds
11. Cadmium and compounds
12. Carbon tetrachloride
13. Chlordane (technical mixture and
metabolites)
14. Chlorinated benzenes (other than
dichlorobenzenes)
15. Chlorinated ethanes (including
1,2-dichloroethane, 1,1,1-
trichloroethane, and hexa-
chlnroethane)
16. Chloroalkyl ethers (chloroethyl
and mixed ethers)
17. Chlorinated naphthalene
18. Chlorinated phenols (other than
those listed elsewhere;
includes trichlorophenols and
chlorinated cresols)
19. Chloroform
20. 2-Chlorophenol
21. Chromium and compounds
22. Copper and compounds
23. Cyanides
24. DDT and metabolites
25. Dichlorobenzenes (1,2-, 1,3-,
and 1,4-dichlorobenzenes)
26. Dichorobenzidine
27. Dichloroethylenes (1,1-and 1,2-
dichloroethylene)
28. 2,4-Dichlorophenol
29. Dichlorophropane and dichloro-
propene
30. 2,4-Dimethylphenol
31. Dinitrotoluene
32. Diphenylhydrazine
117
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TABLE 2. (Continued)
33. Endosulfan and metabolites 47.
34. Endrin and metabolites. . 48.
35. Ethyl benzene 49.
36. Fluoranthene
37. Haloethers (other than those 50.
listed elsewhere; Includes 51.
chlorophenylphenyl ethers, 52.
bromophenylphenylether, 53.
bis(d1chloro1sopropyl) ether, 54.
bls-(chloroethoxy) methane, and 55.
polychlorinated diphenyl ethers)
38. Halomethanes (other than those
listed elsewhere; Includes
methylene chloride, methyl-
chloride, methyl bromide, 56.
bromoform, and dichlorobromo- 57.
methane) 58.
39. Heptachlor and metabolites
40. Hexachlorobutadiene 59.
41. Hexachlorocyclohexane 60.
42. Hexachlorocyclopentadiene 61.
43. Isophorone 62.
44. Lead and compounds 63.
45. Mercury and compounds 64.
46. Naphthalene 65.
Nickel and compounds
Nitrobenzene
Nitrophenols (including 2,4-
dinitrophenol, dinitrocresol)
Nitrosamines
Pentachlorophenol
Phenol
Phthalate esters
Polychlorinated biphenyls (PCBs)
Polynuclear aromatic hydro-
carbons (including benzanthra-
cenes, benzopyrenes, benzofluor-
anthene, chrysenes, dibenzanth-
racenes, and indenopyrenes)
Selenium and compounds
Silver and compounds
2,3,7,8-Tetrachlorodibenzo-p-
dioxin (TCDD)
Tetrachloroethylene
Thai 1 i um and compounds
Toluene
Toxaphene
Trichloroethylene
Vinyl chloride
Zinc and compounds
a The term "compounds" includes both organic and inorganic compounds.
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STABLE 3. SUMMARY OF U.S. EPA MARINE WATER QUALITY CRITERIA
Concentrations (ua/L)
Pollutant
Acenaphthene
Acrolein
Acrylonitrile
Aldrin
Antimony
Arsenic
Pentavalent
Trivalent
Asbestos
Benzene
Benzidine
Beryllium
Cadmium
Carbon tetrachloride
Chlordane
Chlorinated benzenes
Chlorinated ethanes
Dichloroethane 1,2
Hexachloroethane
Pentachl oroethane
Tetrachloroethane 1,1,2,2
Trichl oroethane 1,1,1
Chlorinated ethyl enes
Dichloroethylenes
Tetrachl oroethyl ene
Trichl oroethylene
Acute
970a
55a
b
1.3C
b
2,319a
69d
b
5,100a
b
b
43<1
50,000a
0.09C
160a
113,000a
940a
390a
9,020a
31,200a
224,000a
10,200d
2,000a
Chronic
710a
b
b
b
b
13a
36e
b
700a
b
b
9.3e
b
0.004f
129a
b
b
281 a
b
b
224,000a
450a
b
References
(see below)
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
119
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TABLE 3. (Continued)
Concentrations (ua/L)
Pollutant
Chlorinated naphthalene
Chlorinated phenols
Chlorophenol 2
Chlorophenol 4
Pentachlorophenol (penta)
Tetrachlorophenol 2,3,5,6
Chlorine
Chloroalkyl ethers
Chloroethyl ether
Chloroform
Chlorpyrifos
Chromium
Hexavalent
Trivalent
Copper
Cyanide
DDT
DDT Metal bolites
ODD (TDE)
DDE
Demeton
Dichlorobenzenes
Dichlorobenzidines
Di Chlorophenol 2,4
Dichloropropanes
Dichloropropenes
Acute
7.5a
b
29,700*
13d
440a
13d
b
b
b
0.011d
l,100d
10,300a
2.9d
1.0d
0.13C
3.6a
14a
b
l,970a
b
b
10,300a.
790a
Chronic
b
b
b
7 ge
7>9b
7.5e
b
b
b
0.00566
5oeb
2.9e
1.0e
0.001f
b
b
0.1
b
b
b
3,040a
b
References
(see below)
Goldbook
Goldbook
Goldbook
Update No. 2
Goldbook
Goldbook
Goldbook
Goldbook
Update No. 2
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
120
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TABLE 3. (Continued)
Concentrations (ua/U
Pollutant
Dieldrin
Dimethyl phenol 2,4
Dlnltrotoluene
Dloxln (2,3,7,8-TCDD)
Diphenylhydrazine 1,2
Endosul fan
Endrln
Ethyl benzene
Fluoranthene
Guthion
Haloethers
Halomethanes
Heptachlor
Hexachlorobutadiene
Hexachlorocyclohexane (HCH)
Lindane (gamma -HCH)
HCH (mixture of isomers)
Hexachl orocycl opentadi ene
Isophorone
Lead
Malathion
Mercury
Acute
0.71C
b
590a
b
b
0.034C
0.037C
430a
40a
b
b
12,000a
0.053C
32a
0.16C
0.34a
7.0a
12,900a
140d
b
2.1d
Chronic
0.0019f
b
370a
b
b
0.0087f
0.0023f
a
16a
0.01
b
6,400a
0.0036f
b
b
b
b
b
5.6e
0.1
0.0256
References
(see below)
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
121
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TABLE 3. (Continued)
Concentrations fua/D
Pollutant
Methoxychlor
M1rex
Naphthalene
Nickel
Nitrobenzene
Nitrophenols
Nitrosamines 3
Parathlon
Phenol
Phosphorous (elemental)
Phthalate esters
Polychlorlnated blphenyls
Polynuclear aromatic
hydrocarbons
Selenium (Inorganic selenlte)
Silver
Sulfur (hydrogen sulfide, H2S)
Thallium
Toluene
Toxaphene
Vinyl chloride
Zinc
Acute
b
b
2,350a
75C
6,680a
4,850a
,300,000a
b
5,800a
b
2,944a
10a
300a
410C
2.3*
b
2,130a
6,300a
0.21d
b
95d
Chronic
0.03
0.001
b
8.3'
b
b
b
b
b
0.1
3.4*
0.03f
b
54*
b
2*
b
5,000a
0.00026
b
866
References
(see below)
Goldbook
Goldbook
Goldbook
Update No. 2
Goldbook
Goldbook
Goldbook
Update No. 2
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Update No. 2
Goldbook
Update No. 2
122
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TABLE 3. (Continued)
a Data Insufficient to derive criteria. Value presented is the lowest
observed effect level (LOEL). These concentrations represent apparent
threshold levels for acute and/or chronic toxic effects, and are intended to
convey information about the degree of toxicity of a pollutant in the
absence of established criteria.
b Criterion has not been established for marine water quality.
c Not to be exceeded at any time.
d Maximum 1-h average. Not to be exceeded more than once every 3 yr on the
average.
e Maximum 96-h (4-day) average. Not to be exceeded more than once every
3 yr.
f Maximum 24-h average. Not to be exceeded more than once every 3 yr.
References: Goldbook-U.S. EPA 1986a; Update No. 24J.S. EPA 1987.
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If known or suspected industrial sources of toxic pollutants or
pesticides exist, applicants must submit results of wet- and dry-weather
analyses of the treatment plant effluent. If available, Influent data would
also be helpful. If historic data are available, they should be presented
as well. Results of the analyses should be tabulated in a summary form that
allows the toxic quality of the discharge to be evaluated. The applicant
should describe the sampling effort by describing the procedures for
collecting, compositing, and preserving the samples. The number of grab
samples taken for volatile organics analysis should be included in the
discussion.
Rainfall data submitted for at least 5 days preceding the sampling will
confirm wet or dry conditions at the time of sampling. In past analyses
(Feiler 1980), toxics concentrations have been substantially higher during
Monday through Friday than on Saturday and Sunday. It is therefore
recommended that composite effluent samples not be collected on weekends
unless it can be shown that this sampling period is more representative.
Analytical methods should be discussed, with appropriate references to
published analytical procedures. The identity of the analytical laboratory
should be given. Quality assurance procedures for the analysis should be
summarized, and results presented for review. Differences between the wet-
and dry-weather analysis should be explained, if possible. Also, a
comparison with past results could be made.
Sources of detected toxic pollutants must be identified and, to the
extent practicable, categorized according to industrial and nonindustrial
origins. The purpose of this identification and categorization is to
provide a useful reference for toxics monitoring and source controls. If
the applicant recognizes that the source list requires improvement,
procedures to accomplish this improvement should be described. In-system
sampling and analysis, industrial discharge analysis, permit data, and site
inspections could yield quantitative information as to sources of identified
priority pollutants.
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Special Considerations for Small Dischargers
In the original Section 301(h) application, many small applicants were
exempted from providing an analysis of toxic substances and pesticides in
their effluent because they were able to certify that there are no known or
suspected sources of those substances in their service area. However, those
exemptions were not permanent (U.S. EPA 1982, p. 53673). Subpart 125.62(d)
requires all Section 301(h) permittees to analyze their effluent for toxic
substances and pesticides, to the extent practicable, as part of their
monitoring programs. Hence, to the extent practicable, all Section 301(h)
permittees shall have performed at least one effluent analysis for toxic
substances at a representative time during the 5-yr term of the original
Section 301(h) permit. To the extent practicable, they shall also perform
another effluent analysis for toxic substances at a representative time
during the 5-yr term of the reissued permit. Results of those analyses
should be used to demonstrate compliance with federal water quality criteria.
III.H.2. a. Are there any known or suspected water quality,
sediment accumulation, or biological problems related to toxic
pollutants or pesticides from nonindustrial sources to your
modified discharge(s).
b. If no, provide the certification required by Subpart 125.66(d)-
(2) together with available supporting data.
c. If yes, provide a schedule for development and implementation
of nonindustrial toxics control programs to meet the requirements
of Subpart I26.66(d)(3).
***
Only small dischargers must respond.
The purpose of nonindustrial source control programs is to identify the
specific nonindustrial sources of priority pollutants and pesticides and then
to develop specific means for their control. To properly address these
125
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requirements, the applicant should describe existing programs or present a
schedule and description of proposed programs to Identify and control non-
Industrial sources of toxic pollutants and pesticides. At a minimum, all
applicants must develop a public education program to limit nonindustrial
sources (see Question III.H.7 below).
Nonindustrial source control programs must be developed and Implemented
on the earliest possible schedule. Implementation 1s required within 18
months of the Issuance of a 30l(h)-mod1f1ed permit. The schedule must
Include the following two elements:
• A schedule of activities for identification of nonindustrial
sources of toxic pollutants and pesticides
• A schedule for the development and Implementation of
practicable control programs for nonindustrial sources of
toxic pollutants and pesticides.
Activities to Identify nonindustrial sources could Include literature
searches, in-system sampling and analysis, research on nonindustrial
products commonly released to the sewer, and pooling of information with
other POTW operators having a similar mix of users.
There are no clearly defined rules to determine the level of effort
that an applicant should apply to Identify nonindustrial sources. However,
this level of effort 1s expected to be directly related to the size of the
discharger. For example, dischargers with diverse land uses within the
service area may find 1t necessary to perform in-system sampling and
analysis to explain the occurrence of toxic pollutants and pesticides.
Concentrations of pollutants within the system that are not accounted
for by industrial sources are generally attributable to nonindustrial
sources. Applicants should therefore be careful not to duplicate any in-
system sampling efforts performed for compliance with industrial pretreatment
regulations.
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Extensive control measures may be necessary where nonIndustrial'sources
produce concentrations of toxic pollutants and pesticides within 50 percent
or more of the receiving water criteria after Initial dilution. These
measures could Include control of the sale, use, handling, and disposal
stages of substances that contain priority pollutants and pesticides.
U.S. EPA recognizes the serious potential for adverse effects on marine
organisms and humans that can result from bioaccumulation of discharged
toxic pollutants and pesticides. U.S. EPA also recognizes the potential
complexity of nonindustrial source control programs. Therefore, applicants
are encouraged to consult with U.S. EPA during development of nonindustrial
source control programs. Proposed nonindustrial source control programs are
subject to review and revision by U.S. EPA prior to issuing a Section 301(h)
modified permit, and during the term of any such permit.
IIJ.H.3 Provide the results of wet- and dry-weather effluent
analyses for toxic pollutants and pesticides as required by
Subpart 125.66(a)(l).
*** Large dischargers must respond in full. Small dischargers must respond
to the extent practicable.
III.H.4 Provide an analysis of known or suspected industrial
sources of toxic pollutants and pesticides identified in 2. above.
*** Large dischargers must respond in full. Small dischargers must respond
to the extent practicable.
III.H.5. Do you have an approved industrial pretreatment program?
a. If yes, provide the date of U.S. EPA approval.
b. If no, and if required by 40 CFR Part 403 to have an industrial
pretreatment program, provide a proposed schedule for development
127
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and Implementation of your industrial pretreatment program to meet
the requirements of 40 CFR Part 403.
Large and small dischargers must respond.
An applicant with known or suspected industrial sources of toxic
pollutants or pesticides must have an approved pretreatment program and
demonstrate compliance with Its requirements. Applicants that certify to
the Administrator that they have no known or suspected Industrial sources of
toxic pollutants or pesticides are not required to have an Industrial
pretreatment program.
In this section, applicants required to have an industrial pretreatment
program should clearly present the history of compliance with the Part 403
industrial pretreatment program. If such a program has already been
approved by U.S. EPA it 1s only necessary to indicate the date of approval.
If the program has not been approved, a schedule of activities, including
the expected date of submittal to U.S. EPA, that will lead to compliance
with Part 403 must be provided.
III.H.6. Urban area pretreatment requirement [Subpart 125.65]
a. Provide data on all toxic pollutants introduced into the
treatment works from industrial sources (categorical and non-
categorical).
b. Hote whether applicable pretreatment requirements are in
effect for every industrial source of each toxic pollutant. Are
the industrial sources introducing such toxic pollutants in
compliance with all of their pretreatment requirements? Are these
pretreatment requirements being enforced? [Subpart 125.65(b)(2)]
c. If applicable pretreatment requirements do not exist for each
toxic pollutant in the P07H effluent introduced by industrial
sources,
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Provide a description and a schedule for your development and
- :> "implementation of applicable p re treatment requirements
[Subpart 125.65(c)], or
Describe how you propose to demonstrate secondary removal
equivalency for each of those toxic pollutants, including a
schedule for compliance, by using a secondary treatment pilot
plant. [Subpart 12S.65(d)]
Dischargers serving populations of 50,000 or more must respond.
At the time of final permit approval, applicants must have In effect
applicable pretreatment requirements for each toxic pollutant from Industrial
users that 1s found 1n the proposed discharge. Applicable pretreatment
requirements may take the form of categorical standards, local limits, or a
combination of both. When an Industrial discharger is subject to both a
categorical standard and a local limit, the more stringent of the two limits
applies.
Categorical standards (see 40 CFR 403.6) are nationally uniform,
technology-based limits developed for specific industries. They are applied
when categorical Industrial users are the only sources of particular toxic
pollutants in the POTW waste stream. Local limits for specific toxic
pollutants found in the discharge are applied when the toxic pollutants
cannot be entirely attributed to categorical industrial users.
Local limits (see 40 CFR 403.5) are determined from general and
specific prohibitions. General prohibitions include requirements that
industrial users may not Introduce pollutants into a POTW that will cause
pass-through or Interference with the treatment works. Pass-through is the
discharge of concentrations of toxic pollutants or pesticides that alone or
in combination with discharges from other sources will cause violation of the
applicant's NPDES permit. Interference is the disruption of treatment
processes or operations that alone or in combination with discharges from
129
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other sources causes a violation of the applicant's NPDES permit. Specific
prohibitions include requirements that pollutants with the following
characteristics shall not be discharged to a POTW by industrial users:
• Pollutants that create a fire or explosion hazard
i . • Pollutants that will cause corrosion to a POTW or have a pH
below 5.0
• Pollutants that are solid or viscous and are discharged in
amounts that will obstruct flow in the POTW, resulting in
interference
• Pollutants (Including oxygen-demanding pollutants) that are
released at a rate that will cause interference
• Heat in amounts that inhibit biological activity in the POTW
and result in interference, or cause the temperature at the
POTW to exceed 40° C (104° F) without approval.
For every toxic pollutant in the discharge that is not from a cate-
gorical industrial user and for which there 1s no local limit, the applicant
must develop local limits, or demonstrate secondary removal equivalency to
the U.S. EPA, or use a combination of these alternatives. To demonstrate
secondary equivalency, an applicant must demonstrate that the combination of
its own treatment plus pretreatment by industrial dischargers achieves
"secondary removal equivalency." A successful demonstration of secondary
removal equivalency will show, for each toxic substance in the effluent,
that the applicant's own less-than-secondary treatment plus pretreatment by
industrial dischargers removes that same amount of each toxic substance as
would be removed if the applicant were to apply secondary treatment and
there were no pretreatment requirements for those pollutants. Applicants
must make this demonstration whenever they cannot show that a toxic
pollutant introduced by an industrial discharger 1s subject to an "applicable
pretreatment requirement" in effect.
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To demonstrate secondary removal equivalency, an applicant would need
to use a secondary treatment pilot plant. By diverting part of its Influent
to the pilot plant, the applicant would empirically determine the incremental
amount of each toxic pollutant that would be removed from the Influent if
secondary treatment were applied. Haying determined the amount of each
toxic pollutant removed, the applicant would then demonstrate that its
existing less-than-secondary treatment plus industrial pretreatment removes
the same amount of each toxic substance as did the secondary treatment pilot
plant without any industrial pretreatment.
In cases where an applicant already has an ongoing industrial pretreat-
ment program, it may be simpler to perform this empirical demonstration
using influent that has been subject to that industrial pretreatment. Such
a demonstration would be conservative because it would overstate the amount
of toxic pollutant that would be removed by applying only secondary
treatment. Because it would be conservative, applicants are permitted (but
not required) to make the secondary equivalency demonstration using effluent
that has undergone industrial pretreatment.
III.H.7. Describe the public education program you propose to
minimize the entrance of nonindustrial toxic pollutants and
pesticides into your treatment system [Subpart 125.66(d)(l)].
*** Large and small dischargers must respond.
The applicant must propose a public education program to minimize the
amounts of nonindustrial toxic pollutants and pesticides that enter the
waste stream. The plan must be implemented within 18 months of the issuance
of a 301(h) modified permit. The public education program may include
preparation of newspaper articles, posters, or radio and television
announcements to increase public awareness of the need for proper disposal
of waste oils, solvents, herbicides, pesticides, and other substances that
contain toxic pollutants.
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III.H.8 Provide a schedule for development a/id implementation of
a nonindustrial tvics control program to meet the requirements of
Subpart 125.
Only large dischargers must respond.
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EVALUATIONS OF COMPLIANCE BY U.S. EPA
DETERMINATIONS OF COMPLIANCE WITH SECTION 301(h) MODIFIED PERMIT CONDITIONS
\
POTVIs that hold Section 301(h) modified permits must comply with
Section 301(h) criteria and regulations, applicable state water quality
standards and regulations, and federal water quality criteria (U.S. EPA
1986a). General guidance is presented below for assessing whether a
permittee's demonstration of compliance with the conditions specified in the
Section 301(h) modified permit is reasonable. As discussed under Questions
II.D.1-II.D.4 of the Application Questionnaire (above), the newly mandated
federal water quality criteria [Subpart 125.63(c)(l)] place additional
requirements on all Section 301(h) dischargers. These federal water quality
criteria have the potential to expand the scope of the water quality
demonstrations that must be made by each Section 301 (h) discharger to
include more variables, but do not create a fundamentally different, or new,
class of criteria or requirements that must be met. Therefore, the general
guidance provided below is also relevant to determinations of compliance
with the newly mandated federal water quality criteria that will be
performed by the Regions.
The first step in evaluating a permittee's demonstration of compliance
with applicable criteria and regulations, or in determining compliance with
criteria and regulations when monitoring data are examined by the Regions, is
to compare the data that were submitted by the permittee with the data
collection requirements specified in the existing Section 301(h) modified
permit. The following two key questions should be addressed:
• Were all physical, chemical, and biological variables
required by the Section 301(h) modified permit measured?
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• Was each required variable measured at the specified locations
and at the specified frequency?
If either question cannot be answered affirmatively, the applicant should be
considered not to have complied with the terms of the existing Section
301(h) modified permit.
In cases of apparent noncompllance, the Regions have the option of
denying the application for reissuance of the modified permit without
further examination of the monitoring data. However, the Regions are
strongly advised to ask the applicant (if no explanation of the apparent
deficiencies was previously made by the applicant) the reasons for the
apparent noncompliance. Unforeseen events or conditions beyond the control
of the applicant may have been responsible for failures to execute the
conditions of the modified permit.
Having received all the appropriate data from the applicant, the
Region's second step is to evaluate the technical merit and (as warranted)
the applicant's interpretation of those data. Three major issues should be
addressed during that evaluation:
• Data quality
• Execution of the analyses
«
• Interpretation of the analytical results.
Successful demonstrations of compliance should provide sufficient information
for the Region to document that data quality is high, analyses were properly
executed, and data interpretation is reasonable.
To determine whether the applicant's data were collected properly, the
Regions are referred to guidance given by Tetra Tech (1982a,b, 1987c) and to
guidance given under the appropriate questions in the Application Question-
naire (especially Questions III.F.1-III.F.2). Of critical importance to the
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collection of data for any variable is whether appropriate field and
»
laboratory methods were used to collect the data, and whether appropriate
quality assurance/quality control procedures were followed. Data are of
little value if they were collected using inappropriate methods, or if the
collection process was so poorly executed that their accuracy is in doubt.
As is true for data collection methods, data analysis methods vary
greatly among the various types of physical, chemical, and biological
variables. Again, the Regions are referred to the aforementioned documents.
The following general questions should be addressed during the evaluation of
the data analyses:
• Are values for each variable reported 1n appropriate units?
• Are the analytical methods appropriate for the type of data
being analyzed?
• Do the mathematical or graphical analyses illustrate what is
being discussed in the text of the application?
• Are calculations correct, and have data points been plotted
correctly?
Provided that the foregoing questions (and other questions related to data
analysis that may be relevant in specific instances) are answered in the
affirmative, the Region should determine whether the applicant's data and the
results of analyses of those data support the applicant's conclusions. If
the Region determines otherwise, alternative conclusions must be developed
by the Region for use in determining whether the applicant's existing or
proposed discharge contributes to adverse impacts on the receiving environ-
ment or biota.
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DETERMINATIONS OF COMPLIANCE WITH 301(h) CRITERIA
•
When the permittee's monitoring data Indicate that Impacts to water
quality, sediment quality, or biota are occurring, 1t will be necessary for
the Regions to determine whether such Impacts are adverse. Determinations
of adverse Impacts are reasonably straightforward for many physical and
chemical criteria (e.g., dissolved oxygen concentrations, concentrations of
toxic substances in the water column after Initial dilution) because such
criteria are quantitative, and because determinations of compliance rely
primarily on the results of wel1-documented mathematical calculations.
Providing that the physical and chemical data were properly collected and
analyzed, the resultant values for each physical and chemical variable need
only be compared with applicable Section 301(h) criteria, state standards,
and federal water quality criteria. Results of those comparisons can be
used to determine the presence of an adverse impact that causes noncompllance
with Section 301(h) criteria.
When the values of one or more physical or chemical variables con-
sistently fall outside the ranges specified by the foregoing criteria, the
discharge can be inferred (by definition) to be causing adverse Impacts to
the physical or chemical characteristics of the receiving environment,
thereby resulting in noncompliance with Section 301(h) criteria. In those
cases, the Regions have the option of denying the request for reissuance of
the Section 301(h) modified permit, or requesting that the applicant make
improvements to the outfall or treatment system such that compliance with
applicable criteria Is assured. In most cases, applicants proposing
improvements will be required to predict the values of previously noncom-
pl iant variables following implementation of the proposed improvements.
Determinations of the presence or absence of adverse environmental
impacts that result in noncompliance with Section 301(h) criteria are more
difficult for biological criteria because adverse impacts are not defined
quantitatively. Some extreme adverse impacts may be assessed more easily
because they are defined specifically in the 301(h) regulations, and because
they are endpoints in a spectrum of possible biological conditions that may
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result from the discharge of sewage effluent. For example, the 301(h)
regulations state that conditions within the ZID must not contribute to
extremely adverse biological Impacts, Including the following conditions:
• Destruction of distinctive habitats of limited distribution
• Presence of disease epicenters
• Stimulation of phytoplankton blooms that have adverse Impacts
beyond the ZIO
• Conditions that result in mass mortalities of fish and
Invertebrates.
The regions should deny applications for reissuance of Section 301(h)
modified permits where such impacts have been demonstrated to occur over the
life of the existing permit, or are expected to occur over the life of the
reissued permit. The Regions may consider applications that propose
improvements to eliminate any of the foregoing adverse impacts. But because
all of these impacts are considered extremely adverse, it would be difficult
to demonstrate that a balanced Indigenous population will become rees-
tablished following Improvements to the treatment plant or outfall.
Many biological Impact assessments that are required under 301(h)
regulations necessitate determinations of degrees of impact relative to
unstressed conditions, and subsequent judgments as to whether documented
changes are in compliance with 301(h) criteria. These assessments rely
largely on comparisons of biological conditions between reference areas and
potentially impacted areas to determine the locations of changes along
theoretically or empirically derived gradients of impacts. Quantitative
comparisons between reference and potentially impacted areas may be made
using various types of biological date [e.g., numbers of individuals per
unit area, values of the Infaunal Trophic Index (Word 1978, 1980)] and
various analytical tools (e.g., normal classification analysis) as discussed
under Question III.0.1 (above). However, no quantitative biological criteria
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have been established by which the results of these analyses may be judged.
Therefore, determinations of whether changes In, or differences among,
biological communities constitute noncompl1ance with Section 301(h) criteria
require careful consideration of the types of responses that are manifested
by the pollutant stress, as well as their spatial extents and magnitudes.
Three approaches have been used 1n the 301(h) program to determine
whether a specified degree of change 1n the biota (and associated receiving
environment) should be considered to be 1n compliance with 301(h) criteria.
The first 1s to determine whether the observed change represents a reduction
1n the areal extent or health of a community or ecosystem. This approach has
most often been used 1n cases where the major taxa that characterize the
community greatly modify the environment, thereby creating habitat for other
species. Primary examples Include distinctive habitats of limited distribu-
tion such as kelp communities, coral reefs, and seagrass beds. Because most
of the taxa 1n these communities are highly dependent on the major taxa that
characterize the community (and create habitat niches), the loss of those
major taxa due to pollutant Impacts results 1n destruction of the community.
Unlike some other communities (such as benthic Infauna), one assemblage of
organisms 1s not replaced by another 1n which the species belong to the
same, or similar, major taxonomlc groups, and In which the new taxa are able
to tolerate, and In many cases thrive, in the modified environment.
Clearly, 1n cases where a community or ecosystem 1s highly dependent on a
limited number of major taxa to provide habitat for a wide variety of
dependent species, any loss or decline in the health of those major taxa 1s
an adverse Impact, and 1s therefore not in compliance with 301(h) criteria.
In communities where pollutant Impacts result in changes 1n species
composition and abundance, but not 1n the destruction of the habitat, It Is
more difficult to determine whether such changes constitute noncompllance
with Section 301(h) criteria. However, two approaches to the problem have
been used In the 301 (h) program. The first Is based on the assumption that
a major change In the function (I.e., trophic relationships) of a community
(e.g., benthic infauna, demersal fishes) constitutes noncompl1ance with
138
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Section 301(h) criteria because 1t affects, or has the potential to affect,
all of the major elements of the ecosystem. The second approach 1s a
corollary of the first. It assumes that a major change in the structure
(I.e., species composition and abundance) of a community constitutes
noncompl1ance with Section 301(h) criteria because a change In the function
of that community has occurred, regardless of whether a change 1n function
can be demonstrated. Because a change in the structure of a community is
usually much easier to document than 1s a change in the function of a
community, the second approach has been used most commonly in the 301 (h)
program.
Benthic infauna are used in the following example to demonstrate how
the functional and structural approaches may be implemented. The generalized
model developed by Pearson and Rosenberg (1978) for changes in benthic
communities along a gradient of organic enrichment (Figure 3) has been used
extensively in the 301(h) program, and has been successfully applied to a
variety of soft-bottom benthic communities in temperate and tropical
latitudes. At low to moderate levels of organic enrichment (I.e., the
"transition zone" in Figure 3), biomass increases moderately and numbers of
species Increase slightly. Abundances do not increase greatly until the
"ecotone point" is approached. In the "transition zone," there Is simply an
enhancement of the community that 1s typical of the biogeographic region,
with the addition of a few new species. There are no major functional or
structural changes. Providing that there are no major problems with other
aspects of the benthic Infauna (e.g., bi ©accumulation of toxic substances),
the impact to benthic Infauna may not be considered to be out of compliance
with Section 301(h) criteria.
At and beyond the "peak of opportunists" as shown in Figure 3, Pearson
and Rosenberg (1978) document that species composition and abundance of the
benthic Infauna change substantially. The-fauna becomes dominated by a few
opportunistic or pollution-tolerant species whose abundances increase
dramatically in response to Increased organic loading. Most of these
species are surface or subsurface deposit feeders. Suspension feeders and
surface detrital feeders typically decrease in abundance, or are eliminated.
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Increasing Organic Input
S » Species numbers
A » Total abundance
B • Total biomass
PO « Peak of opportunists
E • Ecotone point
TR » Transition zone
Reference: Figure 2 of Peaison and Rosenberg (1978).
Figure 3. Generalized depiction of changes in species numbers, total
abundances, and total biomass along a gradient of organic
enrichment.
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Hence, the structure (I.e., species composition and abundance) and function
(I.e., trophic relationships) of the benthic infauna are altered sub-
stantially.
In most cases, Information 1s not available to demonstrate that major
changes in the structure and function of a particular benthic community
affect other biological communities (e.g., demersal fishes). However, many
cases of prey specificity by demersal fishes and large epibenthic invert-
ebrates that prey on benthic Infauna have been recorded in the scientific
literature. Hence, there 1s a sound scientific basis for assuming that
major changes In the structure and function of benthic communities as a
result of organic enrichment can induce changes in the species composition
and abundance of predators on Infauna, most of which are demersal fishes and
large epibenthic Invertebrates. Therefore, major changes in the structure
and function of the benthic infaunal community have often been considered
to constitute noncompl1ance with Section 301(h) criteria.
Decisions regarding adverse Impacts should be based on the results of
the biological demonstrations required of the applicant in the various parts
of the Application Questionnaire. Those biological demonstrations should
Include monitoring data collected over the term of the existing modified
permit. The Regions are referred to discussions under relevant questions in
the questionnaire (above) for guidance on data analysis and interpretation.
If a Region decides that an existing discharge may be causing an
adverse impact to the biota, or that the proposed discharge will likely
cause an adverse Impact to the biota, the Region should require that
applicant to perform detailed biological demonstrations to support the
application. Such demonstrations would most likely be required in cases
where possible adverse Impacts would result in noncompl1ance with Section
301(h) criteria, such as adverse Impacts to distinctive habitats of limited
distribution, discharges Into estuarine waters, and discharges into stressed
waters. It Is Important that the Region work closely with the applicant
over the term of the existing permit, so that possible adverse impacts or
conditions that would result in noncompllance with Section 301(h) criteria
141
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are Identified well 1n advance of the application deadline. Early notlflca-
*
tion of potential adverse Impacts will ensure that the applicant has
sufficient time to design and execute appropriate studies. The Region
should also work closely with the applicant during all phases of survey
design and execution to ensure the collection of adequate, high quality data.
EVALUATIONS OF PREDICTED CONDITIONS AND PREDICTED CONTINUED COMPLIANCE
POTWs were allowed to apply for first-time Section 301(h) modified
permits based on current, Improved, or altered discharges. A current
discharge 1s defined 1n Part 125 Subpart G as the volume, composition, and
location of an applicant's discharge at the time of permit application. An
Improved discharge may Include planned Improvements in the outfall, the
level of treatment, discharge characteristics, operation and maintenance, or
controls on the Introduction of pollutants Into the treatment system. An
altered discharge 1s defined as any discharge other than a current discharge
or an Improved discharge as defined 1n Part 125.58.
For Improved and altered discharges, applicants were required to
predict conditions that would occur In the receiving environment following
implementation of the proposed Improvements or alterations. Section 301(h)
modified permits were Issued upon a satisfactory demonstration that the
predicted conditions were reasonable and would satisfy Section 301(h)
criteria and regulations. For dischargers whose original Section 301(h)
modified permit was issued based 1n part on predictions of conditions that
would occur after proposed Improvements or alterations were implemented, it
1s necessary to evaluate whether the predicted conditions have been
realized. Because the Regions should receive monitoring data collected
during the term of the existing permit in support of the application for
permit reissuance, evaluations of the applicant's original predictions of
compliance are not unlike other determinations of compliance. Therefore, the
Regions should conduct those evaluations as discussed above in the two
previous sections of this chapter, entitled "Determinations of Compliance
with Section 301(h) Modified Permit Conditions" and "Determinations of
Compliance with 301(h) Criteria."
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As was permitted for original Section 301(h) applications, applications
for reissuance of Section 301(h) modified permits may propose Improved
levels of sewage treatment, either 1n response to comments by the U.S. EPA,
or at the permittee's Initiative. Applications for permit reissuance that
are based -on altered discharges are also permitted when downgrading of
effluent quality 1s attributable entirely to population growth and/or
Industrial growth within the service area. Proposals for Improved and
altered discharges mandate that the permittee predict the physical,
chemical, and biological conditions that will occur In the receiving en-
vironment. In such cases [as 1n the original Section 301(h) applications],
1t will be necessary for the Regions to evaluate whether the permittee's
predictions are reasonable, and whether the predicted conditions would
satisfy Section 301(h) criteria and regulations.
Evaluations of applicant's predictions should Include the following
assessments:
• Appropriateness of the models used to generate the predictions
• . Data quality
• Execution of the analyses
• Interpretation of the analytical results.
It 1s essential that the applicant conduct each of these steps In the
predictive process properly. Otherwise, the validity of the results and
compliance with applicable regulations and criteria will be suspect.
To predict conditions that will occur as a result of a proposed
discharge, applicants may compare attributes of the proposed discharge (e.g.,
volume and composition) and receiving environment with conditions near other
outfalls that discharge effluent of similar volume and composition and in
similar receiving environments. The validity of such comparisons rests on
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the similarity of the discharges and the similarity of the receiving
environments. Substantial differences 1n the volumes of the two discharges
or the mass emission rates of pollutants from the two discharges would
render such comparisons questionable, especially for biological variables.
For physical and chemical variables, it might be possible to compensate
mathematically for such differences. However, biological responses to
pollutants cannot be assumed to be linear. Therefore, the validity of
predictions Involving comparisons between substantially different discharges
1s very tenuous unless the response patterns of the biota within the
biogeographlc region are well known.
Similarity of the receiving environments 1s also critical to such
comparisons. It is important that both discharges be located within the same
biogeographlc zone because responses to pollutants vary among species.
Species in one biogeographlc zone may respond somewhat differently to a
given pollutant than do species in another biogeographlc zone. For that
reason, it may be possible to predict the general types of changes that may
occur as a result of the proposed discharge, but it will not generally be
possible to predict the areal extent or magnitude of such changes. It is
also important that the physical and chemical characteristics of both
receiving environments be similar. For example, discharges into open
coastal areas should not be compared with discharges in embayments. The
more similar the two receiving environments are to each other, the more
reliable the applicant's predictions may be assumed to be.
Applicants may also use models that describe cause-and-effect rela-
tionships to predict Impacts of the proposed discharge. Such models would be
especially helpful for physical and chemical variables (e.g., deposition of
suspended solids in the receiving environment, concentrations of toxic
substances at the ZID boundary). The appropriateness of such models should
be judged on their prior use in the 301(h) program, their acceptance or
recommendation by the U.S. EPA, and their acceptance by the scientific
community. Models that have not been evaluated previously or that have not
been received favorably should be avoided.
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Having determined that the applicant used appropriate models to predict
conditions 1n the receiving environment and biota, the Region should address
the Issues of data quality, execution of analyses, and interpretation of
analytical results. These Issues should be addressed in a manner similar to
that described above for determining compliance with Section 301(h) modified
permit conditions.
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REISSUANCE OR TERMINATION OF SECTION 301(h) MODIFIED PERMITS
As stated in Subpart 125.59(c)(4), Section 301(h) modified permits "may
be renewed under the applicable procedures of 40 CFR Part 124." Relevant
subparts are Parts 124 Subparts A (General Program Requirements) and D
(Specific Procedures Applicable to NPDES Permits). These subparts provide
an outline of the mechanics of the permit decision-making process, including
review of applications for completeness, conditions for permit reissuance
and termination, and special procedures applicable to Section 301(h)
modified permits. Important sections of these subparts are discussed
briefly below.
In addition, Part 124 provides procedures for public notification,
public hearings, issuance of draft permits, and keeping of the administrative
record (Subparts A and D); procedures governing evidentiary hearings for
U.S. EPA-issued NPDES permits (Subpart E); and procedures governing non-
adversary panel hearings (Subpart F). These procedures are not discussed
below as they are beyond the scope of this document.
PROCEDURES FOR REGULATORY ACTION
Part 124 contains U.S. EPA procedures for issuing, modifying, revoking
and reissuing, and terminating all NPDES permits. Other types of permits
are also included. Regulatory terms used in Part 124 are defined in Part
124.2. All definitions in this subsection remain applicable to applicants
for reissuance of Section 301(h) modified permits.
Subpart D of Part 124 establishes decision-making procedures that are
specific to NPDES permits. All tentative decision documents for 301(h)
permit renewals must be signed by the appropriate Administrator. A tenta-
tive decision document may go to the checklist procedure recommended for
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original 301(h) decisions, or may simply be represented by a cover sheet
referencing the fact sheet and draft permit.
Special procedures relevant to applications for Section 301(h) modified
permits are set forth In Part 124.68. These procedures were also applicable
to original Section 301(h) applications, and remain applicable to applica-
tions for relssuance of Section 301(h) modified permits. When an applicant
falls to meet Section 301(h) requirements, the Region must deny the request.
Information collected during monitoring studies and other studies conducted
during the term of the existing Section 301(h) modified permit will be
critical to this determination. According to Subpart 125.59(e)(H1)(B),
125.61(b)(2), and 125.64(b), the U.S. EPA may not Issue a Section 301(h)
modified permit unless the state has concurred or waived concurrence. It
also specifies actions that may be taken by the State Director in states
with approved NPOES permit programs (discussed earlier).
REGULATORY OPTIONS
Depending on the Region's decision regarding relssuance of a Section
301(h) modified permit, the applicant's permit may be reissued with changes,
reissued without changes, or terminated. Administrative procedures that
should be followed by the Regions when permits are reissued or terminated
are set forth 1n Part 124.5, and are not discussed herein. However, the
conditions under which each of these two regulatory options apply are
relevant to the decision-making process. These conditions, set forth In
Part 122.62-122.64, are discussed below.
Section 301(h) modified permits may be terminated during the term of
the permit, or may be denied during the permit relssuance process for the
following reasons, which are set forth 1n Part 122.64:
• Noncompl1ance with the conditions of the modified permit
• Failure to provide all relevant information or misrepresen-
tation of relevant information
147
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•
• A determination that the modified discharge endangers human
health or the environment, and that such adverse Impacts can
be reduced to acceptable levels through permit modification
or termination
• Any condition that results 1n a temporary or permanent
cessation of the discharge, such as the consolidation of two
POTWs that results 1n elimination of the permittee's
discharge.
All terminations of permits must be made in accordance with procedures
specified in Part 124.
When it 1s evident for reasons specified in Part 122.64 that termination
of a Section 301(h) modified permit 1s warranted, the Regions may terminate
the permit under applicable procedures of Part 124. Section 301(h) modified
permits may be reissued under the provisions of Subpart 122.62(b). Because
no specific guidance is given as to which of these two regulatory options is
appropriate under different conditions, the Regions have considerable dis-
cretionary authority over the reissuance or termination of a Section 301(h)
modified permit that has not been in compliance with all of the 301(h)
regulations. In cases where 1t does not appear that the applicant will be
able to satisfy the conditions of the 301(h) regulations while holding a
Section 301(h) modified permit, the modified permit should be terminated or
allowed to expire without reissuance. However, 1n cases where conditions of
the permit may be adjusted to achieve compliance with the 301 (h) regulations,
the Region may modify the permit with different permit specifications, as
necessary. Effective adjustments of the permit conditions will require
careful examination of all available data and accurate predictions of the
conditions that will result as a consequence of those adjustments.
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and other guidance for 301(h) monitoring variables. Final report prepared
for Marine Operations Division, Office of Marine and Estuarine Protection,
U.S. Environmental Protection Agency. EPA Contract No. 68-01-6938. Tetra
Tech, Inc., Bellevue, WA. 16pp.
Tetra Tech. 1986. Analytical methods for U.S. EPA priority pollutants and
301(h) pesticides in estuarine and marine sediments. Final report prepared
for Marine Operations Division, Office of Marine and Estuarine Protection,
U.S. Environmental Protection Agency. EPA Contract No. 68-01-6938. Tetra
Tech, Inc., Bellevue, WA.
Tetra Tech. 1987a. Evaluation of survey positioning methods for nearshore
and estuarine waters. EPA-430/9-86-003. Final report prepared for Marine
Operations Division, Office of Marine and Estuarine Protection, U.S.
Environmental Protection Agency. Tetra Tech, Inc., Bellevue, WA. 54 pp. +
appendices.
151
-------
Tetra Tech. 1987b. Guidance for conducting fish liver pathology studies
during 301(h) monitoring. EPA-430/9-87-004. Final report prepared for
Marine Operations Division, Office of Marine and Estuarine Protection,
U.S. Environmental Protection Agency. Tetra Tech, Inc., Bellevue, WA.
130 pp. + appendix. -
Tetra Tech. 1987c. Quality assurance and quality control (QA/QC) procedures
for 301(h) monitoring programs: pidance on field and laboratory methods.
EPA-430/9-86-004. Final report prepared for Marine Operations Division,
Office of Marine and Estuarine Protection, U.S. Environmental Protection
Agency. Tetra Tech, Inc., Bellevue, WA. 267 pp. + appendices.
Tetra Tech. 1987d. Bioaccumulation monitoring guidance: 5. strategies
for sample replication and compositing. EPA-430/9-87-003. Final report
prepared for Marine Operations Division, Office of Marine and Estuarine
Protection, U.S. Environmental Protection Agency. Tetra Tech, Inc.,
Bellevue, WA.
Tetra Tech. 1987e. Framework for 301(h) monitoring programs. EPA-430/09-
88-002. Final report prepared for Marine Operations Division, Office of
Marine and Estuarine Protection, U.S. Environmental Protection Agency.
Tetra Tech, Inc., Bellevue, WA. 44 pp.
Tetra Tech. 1987f. Recommended biological indices for 301(h) monitoring
programs. EPA-430/9-86-004. Final report prepared for Marine Operations
Division, Office of Marine and Estuarine Protection, U.S. Environmental
Protection Agency. Tetra Tech, Inc., Bellevue, WA. 17 pp.
Tetra Tech. 1988. Evaluation of differential Loran-C for positioning in
nearshore marine and estuarine waters. Draft report prepared for Marine
operations Division, Office of Marine and Estuarine Protection, U.S.
Environmental Protection Agency. EPA Contract No. 68-C8-0001. Tetra Tech,
Inc., Bellevue, WA.
U.S. Environmental Protection Agency. 1980. Water quality criteria
documents; availability. U.S. EPA, Washington, DC. Federal Register
Vol. 45, No. 231. pp. 79318-79379.
U.S. Environmental Protection Agency. 1982. Modifications of secondary
treatment requirements for discharges into marine waters; final rule. U.S.
EPA, Washington, DC. Federal Register Vol. 47, No. 228. pp. 53666-53684.
U.S. Environmental Protection Agency. 1985a. Methods for measuring the
acute toxicity of effluents to freshwater and marine organisms. Third
Edition. EPA-600/4-85-013. U.S. EPA, Environmental Monitoring and Support
Laboratory, Cincinnati, OH. 216 pp.
U.S. Environmental Protection Agency. 1985b. Water quality criteria;
availability of documents. U.S. EPA, Washington, DC. Federal Register
Vol. 50, No. 145. pp. 30784-30796.
152
-------
U.S. Environmental Protection Agency. 1986a. Quality criteria for water-
1986. EPA-440/5-86-001. U.S. EPA, Office of Water Regulations and Stan-
dards, Washington, DC.
U.S. Environmental Protection Agency. 1986b. Training manual for NPDES
permit writers. U.S. EPA, Office of Water Enforcement and Permits, Washing-
ton, DC. 98 pp. -i- appendices.
U.S. Environmental Protection Agency. 1987. Update No. 2 to quality
criteria for water - 1986. U.S. EPA, Office of Water Regulations and
Standards, Washington, DC. (1 May 1987).
Wang, J.D., and J.J. Connor. 1975. Mathematical modeling of near coastal
circulation. Report No. 200. Massachusetts Institute of Technology, R.M.
Parsons Laboratory for Water Resources and Hydrodynamics, Cambridge, MA.
Westerink, J.J., K.D. Stolzenbach and J.J. Connor. 1985. A frequency
domain finite element model for tidal circulation. Report No. 85-006.
Massachusetts Institute of Technology, Energy Laboratory, Cambridge, MA.
Word, J.Q. 1978. The infaunal trophic index, pp. 19-39. In: Coastal
Water Research Project Annual Report. W. Bascom (ed). Southern California
Coastal Water Research Project, El Segundo, CA.
Word, J.Q. 1980. Classification of benthie invertebrates into infaunal
trophic index feeding groups, pp. 103-121. In: Coastal Water Research
Project, Biennial Report for the years 1979-1980. W. Bascom (ed). Southern
California Coastal Water Research Project, Long Beach, CA.
Young, D.R., D.J. McDermott, and T.C. Heesen. 1976a. DDT in sediments and
organisms around southern California outfalls. J. Water Pollut. Control Fed.
48:1919-1928.
Young, D.R., T.C. Heesen, and D.J. McDermott. 1976b. An offshore biomoni-
toring system for chlorinated hydrocarbons. Mar. Pollut. Bull. 7:156-159.
Young, D.R., M.D. Moore, G.V. Alexander, T.-K. Jan, D. McDermott-Ehrlich,
R.P. Eganhouse, and P. Hershelman. 1978. Trace elements in seafood
organisms around southern California municipal wastewater outfalls. Publ.
No. 60. Southern California Coastal Water Research Project, El Segundo, CA.
104 pp.
153
-------
APPENDIX A
PHYSICAL ASSESSMENT
-------
APPENDIX A
PHYSICAL ASSESSMENT
The primary focus of this appendix is to provide guidance on the
calculation of initial dilution and trapping depth. For the purpose of
Section 301(h) evaluations, "dilution" is defined as the ratio of the total
volume of a sample (ambient water plus wastewater) to the volume of
wastewater in that sample. A dilution of 100 to 1, therefore, is a mixture
composed of 99 parts of ambient water and 1 part of wastewater. The
calculation of initial dilution and trapping depth consists of two set of
procedures:
• Calculate the port flow distribution along the outfall
diffuser(s) for the total effluent flow rates of importance
• Compute initial dilution and trapping depth based on a
characterization of the computed port flow distribution, the
physical characteristics of the outfall diffuser, and
receiving water density and current velocity profiles.
An important variable in both sets of procedures is the total effluent flow
rate. Historical data should be used to determine the minimum, average,
highest 2- to 3-h average, and maximum flow rates for dry-weather, wet-
weather, and annual average conditions. The adequacy of the diffuser's
hydraulic design is dependent on the port flow distribution of the diffuser
during minimum and maximum flow. Characteristics of a hydraulically well-
designed diffuser are described by Grace (1978). According to the Section
301(h) regulations, the critical (i.e., minimum) initial dilutions must be
calculated on the basis of the highest 2- to 3-h average flow rates.
Average flow rates, together with average receiving water current speeds,
are commonly used to compute the trapping depth used in effluent suspended
solids accumulation predictions.
A-l
-------
Port flow distribution along an outfall diffuser is commonly calculated
using computer programs based on well-known hydraulic methods (Grace 1978;
Fischer et al. 1979). This distribution depends on the total effluent flow
rate, the effluent density, the density of seawater at the average diffuser
port depth, and the physical specifications of the diffuser. The physical
specifications include diffuser pipe diameter, depth, and port diameter and
type (i.e., bell-mouth or sharp-edged) for each port in the diffuser. In
the event that the risers are used instead of ports, then specifications
sufficient to compute the discharge coefficient of the risers must be known.
These specifications include the diameter, length, shape, type of transition
between the riser pipe and the diffuser pipe, number of ports, and shape and
diameter of the ports for each riser. The report of Koh (1973) contains a
useful method for computing riser discharge coefficients. (The summary of
this method in Fischer et al. (1979) contains errors.) Head loss deter-
minations for contractions, expansions, and bends can be found in standard
engineering and hydraulics texts (Brater and King 1976; Daugherty and
Franzini 1977).
The port flow distribution should be computed for the minimum and
maximum flows to ensure that the diffuser is hydraulically well-designed
(Grace 1978). For any diffuser, there is a minimum flow below which the
diffuser is inoperable. For lower flows than the minimum, not all of the
ports flow full and the port flows from the diffuser can behave erratically
(Grace 1978). On a sloping bottom, the minimum operational flow usually
increases with increasing bottom slope. Port flows along the diffuser may
be very uneven on a sloping bottom, even for flows above the minimum
operational flow. The hydraulic behavior of the diffuser should also be
checked to investigate whether or not the port flows vary greatly at maximum
flows.
Initial dilution computations are usually not performed for each port
individually, but rather on groups of ports within which the port flows are
relatively uniform. The initial dilution and trapping depth for each group
of ports are then computed based on the average port flow and port depth
A-2
-------
within the group. The group initial dilutions and trapping depths can then
be group flow-rate averaged to obtain estimates of the average'initial
dilution and trapping depth for the diffuser for a specific total effluent
flow rate and set of receiving water conditions. A common choice for a group
is a diffuser pipe section, within which the diffuser pipe diameter and the
diffuser port (riser) specifications are constant.
.Initial dilution is the flux-averaged dilution achieved during the
period when dilution is primarily a result of plume entrainment. It is
averaged over the cross-sectional area of the plume, and characterized by a
time scale on the order of minutes. With proper location and design,
marine outfalls can achieve initial dilution values of about 100 to 1 or
better before the plume begins a transition from essentially vertical flow
to an essentially horizontal flow dominated by ambient oceanographic
conditions.
Adequate initial dilution is necessary to assure compliance with water
quality standards. The following factors influence the degree of initial
dilution that will be achieved:
• Discharge depth
• Flow rates
• Density of effluent
• Density gradients in the receiving water
• Ambient current speed and direction
• Diffuser characteristics
Port sizes
Port spacing
A-3
-------
Port orientation
Port depth.
Because initial dilution calculations can be strongly dependent on the
vertical gradient of ambient density, larger applicants should evaluate a
substantial amount of data from both the discharge site and nearby areas
that have similar environmental conditions before selecting a worst-case
density profile (i.e., the profile producing the lowest initial dilution).
Often the worst-case profiles are not the most stratified, but rather are
those having sufficiently steep density gradients some distance [on the
order of 5 m (16 ft)] above a diffuser port. These profiles can usually be
identified only by computing initial dilutions for several or all of the
available density profiles. Because ambient currents may affect the initial
dilution achieved, a modest amount of current (the lowest 10 percentile) can
be used when predicting initial dilution for use in determining compliance
with applicable water quality standards and criteria.
Five numerical mathematical models to calculate initial dilution
(Muellenhoff et al. 1985a, 1985b) are available from U.S. EPA. Charac-
teristics of these models are summarized below and in Table A-l:
• UPLUME - Analyzes a single, positively buoyant plume in an
arbitrarily stratified stagnant environment.
• UOUTPLM - Analyzes a single, positively buoyant plume in an
arbitrarily stratified flowing environment.
• UDKHDEN - Analyzes a multiport, positively buoyant plume in a
linearly stratified flowing receiving water.
A-4
-------
TABLE A-l. SUMMARY OF PLUME MODEL CHARACTERISTICS*
Model
Name
UPLUME
UOUTPLM
UDKHPLM
UMERGE
ULINE
Current
Speed
No
Yes
Yes
Yes
Yes
Current
Direction e6
•
90°
45° < 9 < 135°
90°
0 < 9 < 180°
Port Type
Single
Single
Multiple
Multiple
Line
Density Profile
Type
Arbitrary
Arbi trary
Arbitrary
Arbitrary
Arbi trary
a From Table 1 of Muellenhoff et al. (1985a).
b A current flowing perpendicular to the diffuser axis has current direction
e - 90°. The widest range of possible angles is 0 to 180°.
A-5
-------
• UMERGE - Analyzes either positively or negatively buoyant
discharges. Analyzes a plume element through the history of
its trajectory and dilution, accounting for the effects of
adjacent plume interference in a receiving water with
arbitrary vertical density and current variation.
• ULINE - Treats discharges, as a line source accounting for
adjacent plume interference. Can analyze positively buoyant
discharges in an arbitrarily stratified receiving water with
a current flowing parallel or perpendicular to the diffuser.
In situ observation may also be used to determine initial dilution.
However, if in situ observations are used, the applicant should demonstrate
that they represent the lowest dilutions in center sections of the effluent
wastefield, not merely a typical dilution.
Other mathematical methods available in the published literature can be
adapted for estimating initial dilution. The following references describe
several of these methods: Abraham (1963, 1971); Baumgartner and Trent
(1970); Baumgartner et al. (1971); Briggs (1969); Brocard (1985); Brooks
(1973); Cederwall (1971); Davis (1975); Davis and Shirazi (1978); Fan
(1967); Hinwood and Wall is (1985); Hirst (1971a,b); Isaacson et al. (1983);
Kannberg and Davis (1976); Koh and Fan (1970); Lee and Cheung (1986); Morton
(1959); Morton et al. (1956); Priestley and Ball (1955); Roberts (1979);
Roberts et al. (1989a,b.c); Rouse et al. (1952); Sotil (1971); Teeter and
Baumgartner (1979); Wallace and Sheff (1987); Winiarski and Frick (1976);
and Wright (1982). Only flux-averaged initial dilutions should be used in
water quality computations. Other types of initial dilutions, such as
center!ine and minimum surface, must be converted to flux-averaged. Many of
the above investigations provide ways to estimate flux-averaged initial
dilutions (see Fischer et al. 1979 for additional guidance).
A-6
-------
REFERENCES
Abraham, G. 1963. Jet diffusion in stagnant ambient fluid. Delft Hy-
draulics Publication No. 29, Delft, Netherlands. 183 pp.
Abraham, G. 1971. The flow of round buoyant jets issuing vertically into
ambient fluid flowing in a horizontal direction. Delft Hydraulics Publi-
cation No. 81, Delft, Netherlands. 7 pp.
Baumgartner, D.J., and D.S. Trent. 1970. Ocean outfall design: Part I.
Literature review and theoretical development. U.S. Department of Interior,
Federal Water Quality Administration, Washington, DC.
Baumgartner, D.J., D.S. Trent, and K.V. Byram. 1971. User's guide and
documentation for outfall plume model. Working Paper No. 80. U.S.
Environmental Protection Agency, Pacific Northwest Water Laboratory,
Corvallis, OR.
Brater, E.F., and H.W. King. 1976. Handbook of hydraulics for the solution
of hydraulic engineering problems. 6th ed. McGraw-Hill Book Company, New
York, NY.
Briggs, G.A. 1969. Plume rise. U.S. Atomic Energy Commission, Oak Ridge,
TN. 81 pp.
Brocard, D.N. 1985. Surface buoyant jets in steady and reversing
crossflows. ASCE J. Hydraul. Eng. 111:793-809.
Brooks, N.H. 1973. Dispersion in hydrologic and coastal environments.
EPA-660/3-73-010. U.S. Environmental Protection Agency, Corvallis, OR.
Cederwall, K. 1971. Buoyant slot jets into stagnant or flowing environment.
Report No. KH-R-25. Cal. Inst. of Tech., Keck Hydraulics Lab. Pasadena, CA.
Daugherty, R.L., and J.B. Franzini. 1977. Fluid mechanics with engineering
applications. 7th ed. McGraw-Hill Book Company, New York, NY. 564 pp.
Davis, L.R. 1975. Analysis of multiple cell mechanical draft cooling
towers. EPA-660/3-75-039. U.S. Environmental Protection Agency, Environ-
mental Research Laboratory, Corvallis, OR.
Davis, L.R., and M.A. Shirazi. 1978. A review of thermal plume modeling.
Keynote address. In: Proc. of the Sixth International Heat Transfer Conf.,
ASME, Aug. 6-11, 1978, Toronto, Canada.
Fan, L.H. 1967. Turbulent buoyant jets into stratified and flowing ambient
fluids. Rep. No. KH-R-15. Cal. Inst. Tech., Keck Hydraulics Lab.,
Pasadena, CA.
A-7
-------
Fischer, H.B., E.J. List, R.C.Y. Koh, J. Imberger, and N.H. Brooks'. 1979.
Mixing in inland and coastal waters. Academic Press, New York, NY. 483 pp.
Grace, R. 1978. Marine outfall systems planning, design, and construction.
Prentice-Hall, Inc., Englewood Cliffs, NJ. 600 pp.
Hinwood, J.B., and I.G. Wallis. . 1985. Initial dilution for outfall
parallel to current. ASCE J. Hydraul. Eng. 111:828-845.
Hirst, E.A. 1971a. Analysis of round, turbulent, buoyant jets discharged
into flowing stratified ambients. Rep. ORNL-4685. U.S. Atomic Energy
Commission, Oak Ridge Nat. Lab., Oak Ridge, TN.
Hirst, E.A. 1971b. Analysis of buoyant jets within the zone of flow
establishment. Rep. N. ORNL-TM-3470. U.S. Atomic Energy Commission, Oak
Ridge Nat. Lab., Oak Ridge, TN.
Isaacson, M.S., R.C.Y. Koh, and N.H. Brooks. 1983. Plume dilution for
diffusers with multiport risers. ASCE J. Hydraul. Eng. 109:199-220.
Kannberg, L.D., and L.R. Davis. 1976. An experimental/analytical investiga-
tion of deep submerged multiple buoyant jets. EPA-600/3-76-001. U.S. En-
vironmental Protection Agency, Environmental Research Laboratory, Corvallis,
OR.
Koh, R.C.Y. 1973. Hydraulic test of discharge ports. Technical Memorandum
73-4. California Institute of Technology, W.M. Keck Laboratory of Hydraulics
and Water Resources, Pasadena, CA.
Koh, R.C., and L.N. Fan. 1970. Mathematical models for the prediction of
temperature distribution resulting from the discharge of heated water in
large bodies of water. Water Poll. Cont. Res. Series Rep. 1613 ODWO/70.
U.S. Environmental Protection Agency.
Lee, J.H.W., and V.W.L. Cheung. 1986. Inclined plane buoyant jet in
stratified fluid. ASCE J. Hydraul. Eng. 112:580-589.
Morton, B.R. 1959. Forced plumes. J. Fluid Mech. 5:151-163.
Morton, B.R., G.I. Taylor, and J.S. Turner. 1956. Turbulent gravitational
convection from maintained and instantaneous sources, pp. 1-23. Proc. of
the Royal Soc. of London, Vol. A234.
Muellenhoff, W.P., A.M. Soldate, Jr., D.J. Baumgartner, M.D. Schuldt, L.R.
Davis, and W.E. Frick. 1985a. Initial mixing characteristics of municipal
ocean discharges. Volume I - procedures and applications. EPA-600/3-85-
073a. U.S. Environmental Protection Agency, Narragansett, RI. 90 pp.
A-8
-------
Muellenhoff, W.P., A.M. Soldate, Jr., D.J. Baumgartner, M.D. Schuldt, L.R.
Davis, and H.E. Frick. 1985b. Initial mixing characteristics of municipal
ocean discharges. Volume II - computer programs. EPA-600/3-85-073b.
U.S. Environmental Protection Agency, Narragansett, RI. 100 pp.
Priestley, C.H.B., and F.K. Ball. 1955. Continuous convection from an
isolated source of heat. Quarterly J. Royal Meteor. Soc. 81:144-157.
Roberts, P.J.W. 1979. A mathematical model of initial dilution for
deepwater ocean outfalls, pp. 218-225. In: Proceedings of a Specialty
Conference on Conservation and Utilization of Water and Energy Resources.
American Society of Civil Engineers.
Roberts, P.J.W., W.H. Snyder, and D.J. Baumgartner. 1989a. Ocean outfalls.
I: Submerged wastefield formation. ASCE J. Hydraul. Eng. 115:1-25.
Roberts, P.J.W., W.H. Snyder, and D.J. Baumgartner. 1989b. Ocean outfalls.
II: Spatial evolution of submerged wastefield. ASCE J. Hydraul. Eng.
115:26-48.
Roberts, P.J.W., W.H. Snyder, and D.J. Baumgartner. 1989c. Ocean outfalls.
Ill: Effect of diffuser design on submerged wastefield. ASCE J. Hydraul.
Eng. 115:49-70.
Rouse, H., C.S. Yin, and W.G. Humphreys. 1952. Gravitational convection
from a boundary source. Tell us 4:201-210.
Sotil, C.A. 1971. Computer program for slot buoyant jets into stratified
ambient environments. Tech. Memo 71-2. Cal. Inst. of Tech., Keck Hydraulics
Lab., Pasadena, CA.
Teeter, A.M., and D.J. Baumgartner. 1979. Predictions of initial dilution
for municipal ocean discharges. Environmental Research Laboratory Pub.
No. 043. U.S. Environmental Protection Agency, Corvallis, OR.
Wallace, R.B., and B.B. Sheff. 1987. Two-dimensional buoyant jets in a
two-layer ambient fluid. ASCE J. Hydraul. Eng. 113:992-1005.
Winiarski, L.D., and W.E. Frick. 1976. Cooling tower plume model.
EPA-600/3-76-100. U.S. Environmental Protection Agency, Environmental
Research Laboratory, Corvallis, OR.
Wright, S.J. 1982. Outfall diffuser behavior in stratified ambient fluid.
ASCE J. Hydraul. Eng. 108:483-489.
A-9
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APPENDIX B
WATER QUALITY ASSESSMENT
-------
CONTENTS
Page
LIST OF FIGURES iii
LIST OF TABLES iv
INTRODUCTION B-l
B-I. SUSPENDED SOLIDS DEPOSITION B-2
SMALL DISCHARGER APPROACH B-2
LARGE DISCHARGER APPROACH B-6
B-II. DISSOLVED OXYGEN CONCENTRATION FOLLOWING INITIAL DILUTION B-15
B-III. FARFIELD DISSOLVED OXYGEN DEPRESSION B-23
SIMPLIFIED MATHEMATICAL MODELS B-25
NUMERICAL MODELS B-35
EVALUATION OF FIELD DATA B-36
B-IV. SEDIMENT OXYGEN DEMAND B-38
B-V. SUSPENDED SOLIDS CONCENTRATION FOLLOWING INITIAL DILUTION B-44
B-VI. EFFLUENT pH AFTER INITIAL DILUTION B-48
B-VII. LIGHT TRANSMITTANCE B-53
B-VIII. OTHER WATER QUALITY VARIABLES B-61
TOTAL DISSOLVED GASES B-61
CHLORINE RESIDUAL B-61
NUTRIENTS B-62
COLIFORM BACTERIA B-64.
REFERENCES B-68
B-ii
-------
FIGURES
Number Page
B-l Projected relationships between suspended solids mass
emission, plume height-of-rise, sediment accumulation,
and dissolved oxygen depression for open coastal areas B-3
B-2 Projected relationships between suspended solids mass
emission, plume height-of-rise, sediment accumulation,
and dissolved oxygen depression for semi-enclosed
embayments and estuaries B-5
B-3 Example of predicted steady-state sediment accumulation
around a marine outfall B-10
B-4 Dissolved oxygen deficit vs. travel time for a submerged
wastefield B-28
B-5 Farfield dilution as a function of 12e0t/B2 B-33
B-iii
-------
TABLES
Number Page
B-l Example tabulations of settleable organic component by
group and maximum settling distance by group B-12
B-2 Example tabulations of deposition rates and accumulation
rates by contour B-13
B-3 Typical IDOD values B-17
B-4 Dissolved oxygen saturation values B-21
B-5 Subsequent dilutions for various initial field widths and
travel times B-41
B-6 Selected background suspended solids concentrations B-46
B-7 Calculated values for the critical effluent Secchi depth (cm)
for selected ambient Secchi depths, initial dilutions, and a
water quality standard for minimum Secchi disc visibility of
1 m B-58
B-iv
-------
INTRODUCTION
This appendix provides detailed guidance for responding to water
quality-related questions in the Application Questionnaire. Methods for
predicting values of the following water quality variables are presented:
• Suspended solids deposition
• Dissolved oxygen concentration following initial dilution
• Farfield dissolved oxygen depression
• Sediment oxygen demand
• Suspended solids concentration following initial dilution
• Effluent pH after initial dilution
• Light transmittance
• Other water quality variables.
B-l
-------
B-I. SUSPENDED SOLIDS DEPOSITION
The applicant must predict the seabed accumulation due to the discharge
of suspended solids into the receiving water. Two prediction methods are
described in this appendix. The first Is a simplified approach for small
dischargers only. If this method is applicable, then a small discharger
need not perform dissolved oxygen calculations dependent on settled effluent
suspended solids accumulations. The second prediction method is applicable
for both small and large dischargers.
SMALL DISCHARGER APPROACH
Two types of problems (dissolved oxygen depletion and biological
effects) and two types of receiving water environments (open coastal and
semi-enclosed bays or estuaries) are considered in the following approach.
Figure B-l is to be used for open coastal areas that are generally
considered well flushed. The dashed line represents combinations of solids
mass emission rates and plume heights-of-rise that would result in a steady-
state sediment accumulation of 50 g/m2. Review of data from several open
coast discharges has indicated that biological effects are minimal when
accumulation rates were estimated to be below this level. Consequently, if
the applicant's mass emission rate and height-of-rise fall below this dashed
line no further sediment accumulation analyses are needed. Applicants whose
charge characteristics fall above the line should conduct a more detailed
analysis of sediment accumulation discussed in the following section.
The solid line in Figure B-l represents a combination of mass emission
rates and plume heights-of-rise that were projected to result in sufficient
sediment accumulation to cause a 0.2 mg/L oxygen depression. Applicants
whose discharge falls below this solid line need not provide any further
analysis of sediment accumulation as it relates to dissolved oxygen.
B-2
-------
7000 r-
6000
$
« 5000
4000
3000
2OOO
WOO
*
III
"
I
02468101214161820
HEIGHT Of RISE, m
STEADY STATE SEDIMENT ACCUMULATION LESS THAN 50g/m2
DO DEPRESSION DUE TO STEADY-STATE SEDIMENT
DEMAND > 012 mg/l
Raf»r»ne»: Tetra Tech (1982).
Figure B-1. Projected relationships between suspended solid mass
emission, plume height-of-rise, sediment accumulation,
and dissolved oxygen depression for open coastal areas.
B-3
-------
Figure B-2 should be used in a similar manner for discharges to semi-
enclosed embayments or estuaries. Because estuaries and semi-enclosed
embayments are potentially more sensitive than open coastal areas, the
critical sediment accumulation was set at 25 g/m2.
Methods described in Tetra Tech (1982) were used to determine the mass
emission rates and heights-of-rise resulting in the sediment accumulation
rates specified above. In order to use these methods, several assumptions
were made. A current velocity of 5 cm/sec was assumed for the open coastal
sites and a velocity of 2.5 cm/sec was assumed for the semi-enclosed
embayments. these velocities are conservative estimates of average current
velocities over a 1-yr period. The settling velocity (Vs) distribution used
is considered typical of primary or advanced primary effluents and is shown
below:
5 percent have Vs > 0.1 cm/sec
20 percent have Vs > 0.01 cm/sec
30 percent have Vs > 0.006 cm/sec
50 percent have Vs > 0.001 cm/sec
The remaining solids settle so slowly that they are assumed to remain
suspended in the water column indefinitely. The effluent is considered to
be 80 percent organic and 20 percent inorganic. The above distribution is
based on the review of data in Section 301(h) applications and other
published data (Myers 1974; Herring and Abati 1978).
The annual suspended solids mass emission rate should be calculated
using the average flow rate and an average suspended solids concentration.
The plume height-of-rise, determined previously in the Initial dilution
calculation, or 0.6 times the water depth, whichever is larger, should be
used to enter the appropriate figure (Figure B-l or B-2).
B-4
-------
4000
g 3000
O
(A
uj 2000
M 1OOO
J I
I
0 24 6 8 10 12 14 16 18 20
HEIGHT OF RISE, m
STEADY STATE SEDIMENT ACCUMULATION LESS THAN 25g/m2
DO DEPRESSION DUE TO STEADY-STATE SEDIMENT
DEMAND > 0.2 mg/l
Reference: Tetra Tech (1982).
Figure B-2. Projected relationships between solid mass emission, plume
height-of-rise, sediment accumulation, and dissolved oxygen
depression for semi-enclosed embayments and estuaries.
B-5
-------
LARGE DISCHARGER APPROACH
The approach described here considers the processes of sediment
deposition, decay of organic materials, and resuspension. However, the
strictly quantitative prediction of seabed accumulation is based only on the
processes of deposition and decay. Because resuspension is not evaluated
easily using simplified approaches, the analyses described in this chapter
consider resuspension separately and in a more qualitative manner that is
based on measured near-bottom current speeds in the vicinity of the diffuser.
Data Requirements
To predict seabed deposition rates of suspended solids, the following
information is required:
• Suspended solids mass emission rate
• Current speed and direction
• Height-of-rise of the plume
• Suspended solids settling velocity distribution.
The mass emission rate, M (kg/day), is:
M = 86.4(S)(Q) B-l
where:
S " Suspended solids concentration, mg/L
Q = Volumetric flow rate, m3/sec.
It is suggested that the applicant develop estimates of the suspended
solids mass emission rate for the season (90-day period) critical for seabed
B-6
-------
deposition and for a yearly period. If the applicant anticipates the mass
emission rate will increase during the permit term, the mass emission rate
at the end of the permit term should be used.
Current-speed data are needed to determine the distance from the
outfall that the sediments will travel before accumulating on the bottom.
Consequently, depth-averaged values are best, if available. Otherwise,
current speeds near mid-depth may be sufficient. The following current data
are needed for the assessment:
• Average value upcoast, when the current is upcoast
• Average value downcoast, when the current is downcoast
• Average value onshore, when the current is onshore
• Average value offshore, when the current is offshore.
If no current data are available, values of 5 cm/sec for longshore transport
and 3 cm/sec for onshore-offshore transport have been found to be reasonable
values.
Plume trapping levels representative of the critical 90-day period and
of the annual cycle are needed. The applicant should use density profiles,
effluent volumetric flow rates, and ambient currents characteristic of these
time periods. Extreme values should not be used. Usually the annual
average and critical 90-day average flow rates and current speeds (in the
predominant current direction) should be used. The expected average plume
heights-of-rise above the seafloor should be determined using available
receiving water density profiles. If large numbers of profiles exist for
each month (or oceanographic season), then the applicant could compute the
plume height-of-rise above the seafloor for each of the available profiles,
and then average the heights. If relatively few profiles are available for
each month, then the applicant could compute the plume height of risk for
each profile and use the lowest height-of-rise as the average. The monthly
B-7
-------
average heights of rise can then be used to compute the average height-of-
rise for annual and critical 90-day periods. If so few profiles exist that
It Is not possible to determine whether differences exist between months (or
oceanographlc seasons), then the applicant should use the lowest plume
height-of-rise (based on calculations using the average effluent flow and
current speed) as the average height-of-rise for both the annual and
critical 90-day periods.
If the applicant has not determined a suspended solids settling
velocity distribution, the following can be used based on data from other
Section 301(h) applications:
Primary or Advanced Primary Effluent Raw Sewage
5 percent have Vs >0.1 cm/sec 5 percent have Vs >1.0 cm/sec
20 percent have Vs >0.01 cm/sec 20 percent have Vs >0.5 cm/sec
30 percent have Vs >0.006 cm/sec 40 percent have Vs >0.1 cm/sec
50 percent have Vs >0.001 cm/sec 60 percent have Vs >0.01 cm/sec
85 percent have Vs >0.001 cm/sec.
The remaining solids settle so slowly that they are assumed to remain
suspended in the water column indefinitely (i.e., they act as colloids).
Consequently, 50 percent of the suspended solids in a treated effluent and
85 percent of those in a raw sewage discharge are assumed to be settleable
in the ambient environment.
Prediction of Deposition
Although a portion of the settled solids is inert, primary concern is
with the organic fraction of the settled solids. For purposes of this
evaluation, composition of the waste discharge can be assumed to be as
fol1ows:
B-8
-------
• 80 percent organic and 20 percent inorganic, for primary or
advanced primary effluent
• 50 percent organic and 50 percent inorganic, for raw sewage.
Accumulation should be predicted for the critical 90-day period when
seabed deposition is likely to be highest and for steady-state conditions
where average annual values are used. The results should be presented in
graphical form, as shown in Figure B-3. Supporting tables should be
submitted with the application. The applicant must exercise judgment when
developing the contours, especially when accounting for rapid depth changes
offshore. Sediment contours should be expressed in units of g/m2, not as an
accumulation depth.
An applicant may use a proprietary or publicly available sedimentation
model. Two widely known models are those of Hendricks (1987), which has
been used extensively offshore of Palos Verdes Peninsula in the Southern
California Bight, and Farley (Tetra Tech 1987), which describes the Ocean
Data Evaluation System (ODES) model DECAL. The model DECAL is publicly
available through the U.S. EPA. A simple model is described herein. It can
be used to obtain acceptable estimates of sediment accumulation in a variety
of environments. If its use results in sediment accumulations that lead to
violations of state standards or federal criteria for receiving water
quality, an applicant may use a more sophisticated effluent sediment
accumulation model that better simulates the marine environment.
The method described below assumes that effluent sediment particles
having a specific particle fall velocity settle uniformly within an
elliptical area. This area depends on the plume height-of-rise relative to
the seafloor (not the port depth), the particle fall velocity, and the
average currents speeds in four directions (upcoast, downcoast, onshore, and1
offshore) appropriate for an effluent wastefield at the plume height-of-rise.
For the following sample calculations, the diffuser was assumed to be a
point source. Use of this assumption may not produce reasonable estimates of
sediment accumulation if the diffuser is long. If the diffuser is long,
B-9
-------
CONTOURS IN FEET
Figure B-3. Examples of predicted steady-state sediment accumulation
around a marine outfall.
B-10
-------
then estimates of the sediment accumulation from each diffuser port can be
summed to obtain an estimate for the entire diffuser. This sum is approxi-
mately the same as that obtained from assuming that the sediment accumulation
area is a ZIO-like area (with ends the same as the similar elliptical halves
computed for a single point discharge) and that the effluent suspended
solids having the specific particle fall velocity uniformly settle in this
area. The sediment accumulation due to the entire discharge is the sum of
the accumulations for each particle fall velocity modeled.
To begin computations for a discharge at a point location, the
applicant can create a table similar to Table B-l, showing the amount of
organic solids that settle within each settling velocity group, and the
maximum distance from the outfall at which each group settles. If the
applicant has current data for more than four quadrants, those data can be
used. The maximum settling distances for each group in each direction are
calculated using the formula shown in the footnote of Table 6-1.
With a sufficiently detailed map (e.g., a NOAA bathymetric chart), each
point 0} through 0^5, or Rj through R2Q» can be plotted with the center of
the diffuser as the reference point. Depositional contours are formed by
the four points that define the perimeter of a depositional field (e.g.,
0^030304). The applicant should join these points by smooth lines, so that
the contours are elliptically shaped. If the applicant has current data at
60° or 30° intervals, instead of the 90° intervals used here, then the
contours could be created more accurately.
The deposition rates corresponding to each contour are determined as
follows. First, predict the deposition rate within each contour due to each
individual settling velocity group, as shown in Table B-2. This quantity
is Mi/Aj, or the group deposition rate divided by the area within the
contour. The area within any contour is a function of the four points
(e.g., Dj, D2, 03, and 04), and is denoted in the table by f(0^20304). A
planimeter is probably the most accurate method of finding the area. Once
the deposition rates by group have been found, then the total deposition
rate can be calculated by summing all contributing deposition rates. For
B-ll
-------
TABLE B-1. EXAMPLE TABULATIONS OF SETTlEAfllE ORGANIC COMPONENT
BY GROUP, AND MAXIMUM SETTLING OISVMCE BY GROUP
Mass Emission Rate - MT
Organic Component * Mo *
0.8 Mf, for primary effluent
0.5 My, for raw effluent
Percent by Settling
Organic Component
Maximum Settlinfl Distance from Outfall
Velocity Group
Primary Effluent
5 (V. * 0.1 cm/sec)
15 (V » 0.01 cm/sec)
10 (V* * 0.006 cm/sec)
20 (V * 0.001 cm/sec)
by Group
0.04 NT
0.12 MT
0.08 MT
0.16 MT
upcoast Oowncoast Onshore
0, D2 03
Dj Dg Oy
D9 °10 °11
Offshore
D4
o8
Sum » Q.40 M,
Rax Sewage
10
10
20
20
25
(VS
-------
TABLE B-2. EXAMPLE TABULATIONS OF DEPOSITION RATES AND ACCUMULATION RATES BY CONTOUR
CD
i
Organic Mass Com-
ponent by Group
Primary Effluent
0.04 M- = M.
0.12 MT " M2
0.08 MT = Mj
0.16 MT = M4
Rax Sewage
0.05 MT = MI
0.05 NT - M2
0.10 MT = Mj
0.10 MT = M4
0.125 MT = Mj
Mass Deposition Total Oroanic Deposition Rate Accumulation (a/of )
Bottoa Area Rate, by Group within Area (g/nr/yr) SteaoV-State
A, - f(D1D2D3D4) M,/A, M^A^/A^/A^^ - f,
A, • fCOrO-O-D.) M,/A- M-/A-+M,/A.«M./A, » f, f,
2 56 IS f f c « i i 4 4 2 1
Aj * f(09D1QD1lD12) Mj/Aj Hj/Aj^^ - fj kd
A4 ' f(D13D14D15D16> VA4 VA4 ' f 4
A, « f(R1R2R3R4) M^A, M1/A1*M2/A2*M3/A3*M4/A4.M5/A5 - f,
Am f/0 D P R \ U /A U /A <44I /A All /A 4*1 /A n 4 f
A i\"C"i"T"O' "<%/"K "o/ "^^"^/ ^i^"/ /"/^"e/^c 'o * I
£ J O / O £ C ££OO%*t33 •> |
A^ * f ( RQK . »R 44^49) 3 i '^»/*5*''* / "**"c/"e ° * 5 *
Antf/DDDDl H / A U /A +M /A • f
A * IX 1A 1^ *. A* A* A A * A ' nC' ^^ A
Aaf/DDDD\ li/A U /A a f
5 17^ IS 19^20 5 'o O 5 5
90 Day
p [1-txp(-90kJ]
ji H-expC-Wk^l
Note: Units of fj are 9/0?/day.
-------
example, the Innermost contour receives contributions from all groups* while
the outermost contour receives a contribution only from one group.
So far, only the rates of organic deposition (in units of g/m2/yr) have
been predicted. The accumulation of the organic material (S-j) can be
predicted by including decay as follows:
. fi
Si (g/mz) • jp » at steady state
d
B-2
Si (g/m2) - ^ [1 - exp (-90 kd)]t for 90 days.
d
The f-j are the deposition rates in units of g/mVday, as contrasted to the
units of g/m2/yr in Table B-2. The decay rate constant, k01)day x [1-exp (-90 x 0.01)j = 49 g/m2. B-4
This example shows that input data for the 90-day and steady-state accumula-
tions are different. Consequently, Tables B-l and B-2 should each be
completed twice. Also the accumulation over a critical 90-day period can
exceed the steady-state accumulation. This is caused by short-term
deposition rates that are considerably higher than the long-term average.
In the example, the maximum 90-day deposition rate of 300 g/m2/yr would
eventually decrease to values below 100 g/m2/yr, so that on a yearly basis
the deposition rate is 100 g/m2/yr.
B-14
-------
B-II. -DISSOLVED OXYGEN CONCENTRATION FOLLOWING INITIAL DILUTION
When wastewater is discharged through a single port or a diffuser, the
effluent forms a buoyant plume that entrains ambient water as it rises.
Because the initial dilution process occurs rapidly (i.e., on the order of
minutes), BOD exertion (a relatively slow process) is negligible during this
period. However, an immediate dissolved oxygen demand (IDOD), which
represents the oxygen demand of reduced substances that are rapidly
oxidized (e.g., sulfides to sulfates), might not be negligible. The
dissolved oxygen concentration following initial dilution can be predicted
using the following expression:
D0f - D0a + (D0e - IDOD - D0a)/Sa B-5
where:
DOf - Final dissolved oxygen concentration of receiving water at the
plume trapping level, mg/L
D0a - Affected ambient dissolved oxygen concentration immediately
upcurrent of the diffuser averaged over the tidal period (12.5 h)
and from the diffuser port depth to the trapping level, mg/L
D0e • Dissolved oxygen of effluent, mg/L
IDOD - Immediate dissolved oxygen demand, mg/L
Sa = Initial dilution (flux-averaged).
The applicant should use the least favorable combination of values for
effluent dissolved oxygen, IDOD, affected ambient dissolved oxygen, and
initial dilution. The effluent dissolved oxygen concentration at the point
B-15
-------
of discharge from the treatment plant is often 0.0 mg/L. Because the
critical case is desired, a concentration of 0.0 mg/L is a reasonable
value. However, if data show that dissolved oxygen concentrations in the
effluent are greater than 0.0 mg/L during the critical periods, then these
data may be used.
The IDOD values typically vary from 0 to 10 mg/L, but can be higher
depending on the level of treatment and presence of industrial flows.
Table B-3 can be used to select reasonable IDOO values. Alternatively, the
IDOD can be measured as discussed below. The influence of the effluent IDOD
on ambient dissolved oxygen can be estimated from the following table
(calculated as -IDOD/Sa):
Contribution of IDOD to Lowering of DOf (mg/L)
Initial Dilution
IDOD (mg/L)
1
2
5
10
20
At high initial dilutions, the IDOD contribution is small. Thus, the
expense of laboratory tests may be unwarranted. If IDOD is to be determined
experimentally, the procedures in Standard Methods (American Public Health
Association 1985, p. 530) should be generally followed except that the
dilution water should be seawater from the discharge site instead of
distilled water, and the effluent sample should be incubated anaerobically
for a length of time equal to the travel times from the plant through the
diffuser for minimum, average, and maximum flow conditions. The effluent
sample should be mixed with the dilution water after incubation. The
dissolved oxygen concentration of the effluent and dilution water should be
measured separately after incubation and before mixing the samples. The
dissolved oxygen of the mixture should be measured 15 min after preparation.
B-16
10
-0.1
-0.2
-0.5
-1.0
-2.0
30
-0.03
-0.07
-0.17
-0.33
-0.67
50
-0.02
-0.04
-0.1
-0.2
-0.4
100
-0.01
-0.02
-0.05
-0.10
-0.20
-------
TABLE B-3. TYPICAL IDOD VALUES
Treatment Level
Untreated or less
than primary
Primary
Advanced primary
Effluent
BODs, mg/L
50-100
50-100
50-100
100-150
100-150
100-150
150-200
150-200
150-200
<50
<50
Travel Time, mina
<60
60-200
200-300
>300
0-100
100-300
>300
0-100
100-300
>300
0-100
100-300
>300
0-60
>60
IDOD, mg/L
5
10
15
20
2
3
4
3
4
5
5
7
8
0
1
a Travel time should include the total travel time from the treatment plant
through the diffuser, including any land portion of the outfall.
Note: Information compiled from 301(h) applications.
B-17
-------
The IDOD Is calculated using the following equation:
(00D)(PD) + (S)(PS) -
- *
IDOD - - - - 5 - * - B-6
PS
where:
IDOD - Immediate dissolved oxygen demand, mg/l
DOQ > Dissolved oxygen of dilution water (seawater), mg/L
PQ * Decimal fraction of dilution water used
S - Dissolved oxygen of effluent after incubation, mg/L
PS » Decimal fraction of effluent used
Dissolved oxygen of mixture after 15 min, mg/L.
Several dilutions should be used, preferably close to the actual initial
dilution, unless the difference between the initial and mixed concentrations
is less than 0.1 mg/L. All data used in the above calculations, the
incubation times, and the computed results for each test should be included
in the application.
The lowest initial dilution (flux-averaged) should be used for the
final dissolved oxygen calculation. Usually, this dilution will correspond
to the maximum flow rate at the end of the permit term. Low initial
dilutions can also occur at smaller effluent flow rates if stratification is
sufficiently severe. Typically, dilutions Huring periods of maximum
stratification should be used for the final dissolved oxygen calculation.
The affected ambient dissolved oxygen concentrations should also
represent critical conditions. Usually, critical conditions will occur
B-18
-------
during the maximum stratification period in the late summer or in the spring
*
when upwelling of deep ocean water occurs. For existing discharges, the
affected ambient data should be collected at locations directly upcurrent of
the diffuser, thereby incorporating the potential effects of recirculation.
For proposed new or relocated discharges, affected ambient dissolved oxygen
levels upcurrent of the diffuser should be estimated from mathematical
models of the discharge or by extrapolation from similar situations.
Dissolved oxygen data, as well as any ambient water quality constituent, may
be averaged between the depth of the discharge ports and the plume trapping
level, which corresponds to the lowest initial dilution that was used to
predict the final dissolved oxygen concentrations. If applicants use a
mathematical model that allows multiple vertical levels of input for ambient
water quality instead of an average value, this should be noted.
The time period over which ambient data may be averaged may depend on
specifications of intensity and duration factors in applicable water quality
standards. For example, if certain numerical values shall not be compromised
over a period of 4 h, a 4-h average of input data may be reasonable. Absent
any more stringent specification in locally applicable standards, an average
over a half tidal cycle (approximately 12.5 h) would provide a generally
conservative estimate.
The affected ambient dissolved oxygen concentration can change
substantially as a function of depth, depending on environmental character-
istics and seasonal influences (e.g., upwelling). As the plume rises during
initial dilution, water from deeper parts of the water column is entrained
into the plume and advected to the plume trapping level. If the dissolved
oxygen concentration is lower in the bottom of the water column than at the
trapping level, the low dissolved oxygen water is advected to a region
formerly occupied by water containing higher concentrations of dissolved
oxygen. The result is an oxygen depression caused by entrainment.
This oxygen depression caused by the waste discharge and associated
entrainment (ADOj) should be computed as the difference between DOf as
B-19
-------
defined in Equation B-5 and the affected ambient dissolved oxygen concen-
tration at the trapping depth (D0t).
ADOj - D0f - D0t - D0a - D0t * (DOC_ - IDOD - D0a)/Sa B-7
The oxygen depression of the wastefield relative to the trapping depth
expressed in percent is (-ADOi/DOt)lQO.
For cases when the effect of entraining low dissolved oxygen water can
be neglected, the oxygen depletion (ADO?) should be computed as the
difference between the average affected ambient dissolved oxygen concentra-
tion (D0a) in the entrained water and OOf as shown below.
AD02 - DOf - D0a - (D0e - IDOD - D0a)/Sa B-8
The oxygen depletion of the wastefield relative to the average affected
ambient dissolved oxygen concentration is (-AD02/DOa)100.
The equation of Baumgartner (1981) for the percentage depression is:
(D0f - D00 -i- IDOD)
D0t x Sa *
This equation can be derived by assuming that D0a - DO^ In Equation B-7.
Use of Equation B-9 has been allowed in the State of California.
These differences can be described as a percentage of the ambient
concentration or as a numerical difference, depending on the requirements of
the state. In some states, the final dissolved oxygen concentration must be
above a specified limit or must be converted to percent saturation to
determine whether the final concentration is above a prescribed limit.
Dissolved oxygen saturation can be determined as a function of temperature
and salinity using the method of Green and Carritt (1967) and Hyer et al.
(1971) as tabulated in Table B-4. The applicant may want to consult with
B-20
-------
TABLE B-4. DISSOLVED OXYGEN SATURATION VALUES
Dissolved Oxvaen Saturation. ma/L
Temperature
(° C) 20
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
12
12
12
11
11
11
11
10
10
10
10
9
9
9
9
8
8
8
8
8
8
7
7
7
7
7
7
7
7
7
7
.8
.5
.1
.8
.5
.3
.0
.7
.5
.2
.0
.6
.5
.3
.1
.9
.7
.6
.4
.2
.1
.9
.8
.7
.6
.5
.4
.2
.2
.1
.1
22
12.
12.
12.
11.
11.
11.
10.
10.
10.
10.
9.
9.
9.
9.
9.
8.
8.
8.
8.
8.
8.
7.
7.
7.
7.
7.
7.
7.
7.
7.
7.
6
3
0
7
4
1
9
6
3
1
9
6
4
2
0
8
6
5
3
1
0
9
7
6
5
4
3
2
1
1
1
24
12.5
12.2
11.9
11.5
11.3
11.0
10.7
10.5
10.2
10.0
9.7
9.5
9.3
9.1
8.9
8.7
8.5
8.4
8.2
8.0
7.9
7.7
7.6
7.5
7.4
7.3
7.2
7.2
7.1
7.0
7.0
Salinity (ppt)
26 28 30
12.3
12.0
11.7
11.4
11.1
10.8
10.6
10.4
10.1
9.8
9.6
9.4
9.2
9.0
8.8
8.6
8.4
8.3
8.1
8.0
7.7
7.7
7.6
7.5
7.4
7.3
7.2
7.1
7.0
7.0
6.9
12.1
11.8
11.5
11.2
11.0
10.7
10.4
10.2
9.9
9.7
9.5
9.3
9.1
8.9
8.7
8.5
8.3
8.2
8.0
7.9
7.7
7.6
7.5
7.4
7.3
7.2
7.1
7.0
7.0
6.9
6.9
12.0
11.7
11.4
11.1
10.8
10.6
10.3
10.1
9.8
9.6
9.4
9.2
9.0
8.8
8.6
8.4
8.2
8.1
7.9
7.8
7.6
7.5
7.4
7.3
7.2
7.1
7.1
7.0
6.9
6.9
6.8
32
11.8
11.5
11.2
10.9
10.7
10.4
10.2
9.9
9.7
9.5
9.2
9.0
8.8
8.7
8.5
8.3
8.1
8.0
7.8
7.6
7.6
7.5
7.4
7.3
7.2
7.1
7.0
6.9
6.9
6.8
6.8
34
11.7
11.4
11.1
10.8
10.5
10.3
10.0
9.8
9.6
9.3
9.1
8.9
8.7
8.5
8.4
8.2
8.0
7.9
7.7
7.6
7.5
7.4
7.3
7.2
7.1
7.0
7.0
6.9
6.9
6.8
6.8
36
11.5
11.2
10.9
10.7
10.4
10.1
9.9
9.7
9.4
9.2
9.0
8.8
8.6
8.4
8.3
8.1
8.0
7.8
7.6
7.5
7.4
7.3
7.2
7.1
7.1
7.0
7.0
6.9
6.8
6.8
6.7
B-21
-------
the state water quality agency to determine whether any other methods are
i
used to determine compliance with the dissolved oxygen standards.
B-22
-------
B-III. FARFIELD DISSOLVED OXYGEN DEPRESSION
Subsequent to Initial dilution, dissolved oxygen in the water column is
consumed by the BOD in the wastefield. The effluent 800$ after initial
dilution is needed to estimate farfield dissolved oxygen depletion. The
final BODs concentration can be estimated using the following expression:
BODf - BODa -i- (BODe - BODa)/Sa B-10
where:
BODf = Final 6005 concentration, mg/L
BODa = Affected ambient BODs concentration immediately updrift of the
diffuser averaged over one-half the tidal period (12.5 h) and from
the diffuser port depth to the trapping depth, mg/L
BODe = Effluent BODs concentration, rng/L
Sa = Initial dilution (flux-averaged).
This equation provides an estimate of the total BODs concentration in
the receiving water. The maximum contribution due to the effluent alone can
be determined by dividing the effluent BODs concentration by the initial
dilution. This value is used later to estimate farfield effects of the
effluent. As a critical case, the maximum monthly average effluent BODs
concentration should be used with the (monthly) critical initial dilution.
For existing plants, the previous 12 mo of effluent BODs data is used to
support the selection of a BODs concentration. For proposed or modified
treatment plants where effluent data are not available, monthly average
influent BODs data should be provided along with the range of daily values.
B-23
-------
The average removal efficiency for the new or modified plant is also needed
to compute estimated effluent BODs concentrations.
Three approaches to assessing farfield dissolved oxygen demand are
described below:
• Simplified mathematical models predicting dissolved oxygen
depletions, using calculation techniques that do not require
computer support
• Numerical models predicting dissolved oxygen depletions, using
a computer
• Evaluation of field data, using a data-intensive approach
where dissolved oxygen concentrations are measured in the
water column and compared to ambient concentrations.
Before undertaking any analysis to determine whether farfield BOD
exertion causes a violation of the dissolved oxygen standard, the applicant
should first check to see whether:
DO$TD < DOf - BODfu, for critical conditions B-ll
where:
DO$TD * Dissolved oxygen standard
DOf » Dissolved oxygen concentration at the completion of initial
dilution
BODfu « Ultimate BOD at the completion of initial dilution (- BODf x 1.46).
If the above inequality is true, then the discharge will not violate the
dissolved oxygen standard due to BOD exertion and no further analysis of
B-24
-------
farfield BOD exertion is required. If the Inequality is not true, then
further analysis Is required.
SIMPLIFIED MATHEMATICAL MODELS
Oxygen depletion due to coastal or estuarine wastewater discharges 1s
primarily caused by exertion of BOD, although increased nutrient levels can
affect oxygen concentrations indirectly by altering algal photosynthesis and
respiration rates. BOD consists of a carbonaceous component (CBOD) and
nitrogenous component (NBOD). Both components can contribute to oxygen
depletion. CBOD is often reported as BODs, the 5-day BOD. Before using BOD
to predict oxygen depletion, the applicant should convert it to BOD|_, the
ultimate BOD, by the following relationship:
BODL -1.46 BOD5 B-12
A typical decay rate for CBOD is 0.23/day (base e) at 20° C. A temperature
correction should be made as follows:
kT - 0.23 x 1.047T-20/day B-13
where:
kj » BOD decay rate at temperature T (° C).
NBOD might not always contribute to oxygen depletion. If the applicant
discharges into open coastal waters where there are no other major discharges
in the vicinity, the background population of nitrifying bacteria might be
negligible. Under these circumstances, the NBOD will not be exerted
immediately. In more enclosed estuarine waters, nitrification in the water
column has been documented from numerous water quality studies. Applicants
should analyze the potential impact of NBOD, if they discharge into
estuarine waters.
B-25
-------
NBOD can be estimated based on data for total Kjeldahl nitrogen
concentration (the sum of organic nitrogen and ammonia nitrogen) in the
waste discharge using the following relationships:
NBODL - 4.57 (TKN) B-14
NBOD5 - NBODL/2.54
where:
TKN - Total Kjeldahl nitrogen
NBODL - Ultimate NBOO
NBODs * 5-day NBOO.
The decay rate of NBOO can be taken as:
kT » 0.10 x 1.047T-20/day B-15
where:
kj - The decay rate at temperature T (° C)
0.10 - The decay rate at 20° C (base e).
Simplified mathematical models are an acceptable alternative to the
more complex numerical models. In the simplest model of oxygen depletion,
the following are generally assumed:
• The wastewater plume is submerged at the completion of
initial dilution for critical conditions (so that direct
reaeration of atmospheric oxygen into the wastefield does not
occur).
B-26
-------
• Oxygen depletion is a function of distance from the discharge
and is caused by carbonaceous oxygen demand and nitrogenous
oxygen demand.
• The wastefield entrains ambient water as a function of travel
time. Lateral dilution is the predominant mechanism of
entrainment.
If the applicant demonstrates that the plume will always surface, then the
effects of atmospheric reaeration can be included; otherwise they should not
be included.
When applying a model that predicts farfield oxygen depletion, it is
suggested that the applicant plot dissolved oxygen depletion as a function
of travel time so that the behavior of dissolved oxygen concentrations in
the wastefield can be examined to locate minimum values.
Example oxygen depletion curves as a function of travel time are shown
in Figure B-4. The depletion indicated at time, t=0, denotes the depletion
immediately following initial dilution. The dissolved oxygen deficits
plotted in the figure are relative to the ambient concentration, and tend to
approach zero at travel times longer than those shown in the figure.
For the three cases, the maximum deficits occur at the following travel
times:
• 0.0 days for Curve A
• Approximately 0.2 days for Curve B
• Approximately 4.0 days for Curve C.
The primary reason for the difference in magnitude and time of occurrence of
the maximum deficits is the IDOD, which varies from a high of 66 mg/L for
Curve A to 0.0 mg/L for Curve C. When the IDOD is 66 mg/L (a high value,
B-27
-------
1.0 -
0.9 -
0.8 -
0.7 -
5 0.6 -
2
X 0.5 —
o
UJ 0.4 —
I:;:
0.1 —
0.0
I I I
1 2 3
TRAVEL TIME (days)
CURVE
A
B
C
BODf
(ultimata)
(mg/L)
3.5
3.5
3.5
INITIAL
DO DEMAND
(rng/l.)
66.
44.
0.
Figure B-4. Dissolved oxygen deficit vs. travel time for a submerged
wastefield.
B-28
-------
but one that could be associated with an unusual discharge), the maximum
depletion is caused by initial mixing processes, and not by farfield BOD
exertion. Conversely, when IDOD is 0.0 mg/L, the maximum depletion is
caused by BOD exertion, and occurs at some distance from the discharge.
The simplified farfield oxygen depletion model for coastal waters
suggested herein is based on an approach developed, by Brooks (1960) for
i ...
predicting wastefield dilution subsequent to initial dilution. The
dissolved oxygen concentration in the receiving waters can be expressed as a
function of travel time as follows:
D0f-D0a L<- Lfn
D0(t) - D0a + Tn * - ^ l-exp(-k t) - fr11 l-exp(kt) B-16
a us us c us n
where:
D0(t) = Dissolved oxygen concentration in a submerged wastefield as a
function of travel time t, mg/L
D0a - Affected ambient dissolved oxygen concentration immediately
updrift of the diffuser, mg/L
DOf = Dissolved oxygen concentration at the completion of initial
dilution calculated using Equation B-5, mg/L
kc = CBOD decay rate constant
kn = NBOD decay rate constant
Lfc = Ultimate CBOD concentration above ambient at completion of initial
dilution, mg/L
B-29
-------
Lfn - Ultimate NBOO concentration above ambient at completion of initial
dilution, mg/L
Ds - Dilution attained subsequent to Initial dilution as a function of
travel time.
The above equation expresses the dissolved oxygen deficit that arises
because of an initial deficit at the completion of initial dilution (D0a-D0f)
plus that caused by exertion of BOD in the water column. The last term in
the above equation estimates the exertion due to NBOD. The dissolved oxygen
deficit tends to decrease at longer travel tines as a result of subsequent
dilution and to increase as a result of BOD exertion. Depending on the
particular case being analyzed, one influence can dominate the other over a
range of travel times so that a minimum dissolved oxygen level can occur
either immediately following initial dilution or at a subsequent travel
time, as previously shown in Figure B-4.
To predict farfield oxygen distribution, one must determine the
dilution attained within the wastefield as a function of time following
discharge. For open coastal areas, dilution is often predicted using the
4/3 law (Brooks 1960), which states that the lateral diffusion coefficient
increases as the 4/3 power of the wastefield width. In mathematical form:
B-17
°\"/
where:
e - Lateral diffusion coefficient, ft^/sec
c0 » Diffusion coefficient when L = b
L » Width of sewage field at any distance from the ZID, ft
b = Initial width of sewage field (approximately as the longest
dimension of the ZID), ft.
B-30
-------
The initial diffusion coefficient can be predicted from:
€0 - 0.001
Based on the 4/3 law, the centerline dilution, 0$, is given by:
1/erf
-1
1/2
where:
t - Travel time, sec
erf - The error function.
B-18
B-19
The 4/3 law is not always applicable, especially in coastal areas or
estuaries. In coastal areas, Grace (1978} suggests that the diffusion
coefficient vary linearly with L. The subsequent dilution can be expressed
as:
1/erf
1/2
B-20
A more conservative choice is to assume the diffusion coefficient is a
constant. The subsequent dilution can then be expressed as:
1/erf
116
B-21
B-31
-------
These three equations are cumbersome to use, especially if repeated
applications are needed. To facilitate predicting subsequent dilutions,
values of Ds as a function of 12e0t/b2 are shown in Figure B-5 for values
of Brooks' n equal to 0, 1, and 4/3. For example, 1f b - 100 ft, and
t - 9,000 sec (2.5 h), then e0 - 0.464 ft2/sec and 12e0t/b2 - 5.0. Assuming
that Brooks' n - 1, then use of Figure B-5 shows that Ds -4.3 approximately.
The figure also reveals that the predicted dilutions are substantially
different, depending on the relationship obeyed by the lateral diffusion
coefficient. In some instances, the Brooks' n - 1 law might overestimate
subsequent dilution, even if the outfall is in coastal waters. To attain
the subsequent dilutions predicted at large travel times, a large amount of
dilution water must be available. Because many outfalls, particularly small
ones, are not far from shore, the entrainment rate of dilution water can be
restricted by the presence of the shoreline and the depth of the water. As
the wastefield widens substantially, the rate of entrainment could decrease,
and neither the Brooks' n - 4/3 nor the Brooks' n - 1 law may be obeyed. It
is suggested that applicants be conservative and base subsequent dilution on
a constant lateral diffusion coefficient (i.e., Brooks' n - 0), rather than
the Brooks' n - 1 or Brooks' n « 4/3 laws. However, if the applicant can
show that the 4/3 law (or some other relationship) is applicable to the
discharge site, then that relationship should be used.
If the applicant's discharge is near the mouth of a wide estuary, the
approach just discussed can be used directly to predict oxygen depletion.
If, however, the applicant discharges into a long narrow estuary, then it is
likely that the sides of the estuary will limit the lateral dilution that is
attainable. Under these conditions, the maximum dissolved oxygen deficit
with respect to saturation can be predicted as:
kW
A(k2-k)
B-22
B-32
-------
CD
u>
CO
16 -i
14 -
12 -
10 -
3 >H
UJ
C 6 -
DC
4 "*"•
2 -
n = 4/3
n=1
—*- ~<~r~m-L ™~ --~i n = 0
I
2
\
5
I
8
I
10
!2e0t/B2
Reference: Brooks (1060).
Figure B-5. Farfield dilution as a function of 12
-------
where:
D - Dissolved oxygen deficit
A - Cross-sectional area of the estuary near the discharge site
k * CBOD decay rate constant
k£ - Reaeration rate constant
E|_ - Longitudinal dispersion coefficient
W - Mass loading rate of CBOD.
The applicant can predict the deficits due to NBOD by using the appropriate
k and W values and adding the two deficits to get the total. With reasonable
values for the constants, the total dissolved oxygen deficit for discharge
to narrow estuaries becomes:
D - (3.14 Wc ^ 2.55 Wn) 10'4/A B-23
where:
A » Cross-sectional area in m^
Wc - Mass emission rate of CBOD, g/day
Wn - Mass emission rate of NBOD, g/day
D - Dissolved oxygen deficit, mg/L.
The NBOD term can be added when data are available.
B-34
-------
NUMERICAL MODELS
Numerical models are an acceptable method of predicting oxygen
depletion caused by a discharge. Numerical models may consider the combined
effect of farfleld demand In the water column, as discussed above, and the
oxygen demand associated with organic sediments. If not, the applicant may
have to augment the numerical modeling analysis to address unanswered
questions associated with sediment oxygen demand.
The applicant should try to isolate the impact of the outfall on
dissolved oxygen concentrations by considering that the applicant's discharge
1s the sole source of oxygen depletion in the system being modeled. The
applicant can then predict the dissolved oxygen depletion caused by the
discharge by subtracting the background dissolved oxygen level from those
predicted by the model. This approach also simplifies the applicant's
analysis because data from other wastewater sources are not required.
Specific guidelines can be offered to applicants who choose to use
numerical models. Typically, the most severe dissolved oxygen depletion due
to BOD exertion occurs when the water column is density stratified in the
presence of tidally reversing currents and low nontidal currents, and the
wastefield remains submerged following initial dilution. If such conditions
occur at the applicant's outfall site, then the numerical model should be
layered vertically, with a minimum of two layers. The plume should be
discharged into the bottom layer to simulate the submerged discharge with
the consequence that direct atmospheric reaeration is not present in this
layer.
The applicant should set up the grid system for the numerical model
such that the smallest segments are located in the vicinity of the diffuser
and gradually increase in size with distance from the diffuser. The volume
of the segments in the immediate vicinity of the diffuser should approximate
the volume of the ZID in order to prevent an initial dilution that is
artificially high and that would cause the model to underestimate dissolved
oxygen depletion. The applicant might choose to experiment with grid
B-35
-------
configuration by starting with a coarse grid and then decreasing grid size
until the model results do not significantly change.
A steady-state numerical model will be acceptable for the dissolved
oxygen analysis because dynamic or unsteady analyses are generally more
costly, more difficult to implement, and require more data.. The applicant
should consider, however, whether intratidal variations can cause more
severe depletions than are predicted by a steady-state model that calculates
average oxygen depletions over a tidal cycle. Slack tide, for example,
might be critical because oxygen-demanding materials can accumulate in the
vicinity of the discharge. For existing discharges, the applicant might
want to augment the steady-state modeling analysis by an abbreviated
sampling program to determine dissolved oxygen depletions during slack-tide
periods within a tidal cycle. Intratidal variations are likely to be more
important in enclosed estuaries than along open coastal areas.
EVALUATION OF FIELD DATA
Extensive field data collection and analysis are required to fully
implement this third approach. Limited samples of water column dissolved
oxygen may be inadequate to demonstrate compliance with standards under
critical conditions. Limited information should be supplemented with
analyses based on numerical or simplified mathematical modeling.
These statements should not discourage applicants from collecting and
submitting dissolved oxygen data from the vicinity of an existing discharge.
To the contrary, such data, if available, should be submitted, particularly
if the Section 301(h) application is for a current discharge or for an
improved or altered discharge at the same location. However, the data might
reveal only a portion of the impact of the wastefield, for the following
reasons:
• The location of the maximum oxygen depletion might not be
sampled.
B-36
-------
• The sampling program could have been conducted during* a
period that was not critical with respect to the discharge
or receiving water conditions. Critical discharge conditions
are generally associated with high effluent BOD and high
volumetric flow rates. Critical receiving water conditions
are usually associated with minimum initial dilutions
(maximum density stratification), maximum water temperatures,
and possibly slack-tide or low nontidal current conditions.
• Ambient dissolved oxygen concentrations can vary spatially
and temporally for conditions unrelated to the discharge
(e.g., upwelling effects). Consequently, dissolved oxygen
depletions associated with the discharge can be masked by
background variability.
Some applicants might have access to dissolved oxygen demand data
collected adjacent to another outfall at a nearby coastal area and attempt to
use those data to show that their own discharge will not violate dissolved
oxygen standards. This approach can be, but is not always, reliable. The
applicants should include in the application sufficient information such
that the data collection program for the nearby area can be reviewed, and
then show that the predicted dissolved oxygen depletions are the maximum
likely to be produced at the nearby discharge site. The applicant should
also demonstrate that the results of the nearby discharge can be extrapolated
to the applicant's discharge. Essentially, the dissolved oxygen depletion
at the adjacent discharge (due to both BOD utilization and sediment oxygen
demand) will need to be at least as severe as that at the applicant's
discharge.
B-37
-------
B-IV. SEDIMENT OXYGEN DEMAND
The oxygen depletion due to a steady sediment oxygen demand can be
predicted by:
SB XM - a S kd XH R ,.
86,400 UNO 86,400 UHD b~"
where:
ADO - Oxygen depletion, mg/L
SB - Average benthic oxygen demand over the deposition area, -g 02/mVday
XM » Length of deposition area (generally measured in longshore
direction), m
H - Average depth of water column influenced by sediment oxygen
demand, measured above bottom, m
U - Minimum sustained current speed over deposition area, m/sec
kd - Sediment decay rate constant, 0.01/day
a = Oxygen:sediment stoichiometric ratio, 1.07 mg 02/mg sediment
S= Average concentration of deposited organic sediments over the
deposition area, g/m?
D = Dilution caused by horizontal entrainment of ambient water as it
passes over the deposition area (always >1).
B-38
-------
Both S and Xjyj can be determined from the analysis performed in the Chap-
ter B-I on "Suspended Solids Deposition." Figure B-4 in that chapter shows
an example plot of seabed deposition. For that example, an appropriate
estimate of S is the average of the maximum and minimum values, or
- 52 g/m2 B-25
The distance XM, measured parallel to the coast and within the 5
contour, is 8,000 m.
The depth of water affected by the sediment oxygen demand is not really
a constant value (as suggested by the previous formula) but varies as a
function of the travel time across the zone of deposition. The affected
depth H (in meters) is chosen to represent the average depth influenced by
the sediment oxygen demand and can be estimated as:
sM1/2
H - 0.8 I -V*) B-26
where:
ez - Vertical diffusion coefficient (cm2/sec).
For the example case where U - 3 cm/sec, XM = 8,000 m, and ez « 1
H . 0.8 x/l * MOO y 100y/2 x J. „ . 4.j . „.„
If the applicant desires to compute a value of vertical diffusivity,
the following empirical expression can be used:
B-39
-------
z 1 d£
p dz
where:
€z « Vertical diffusion coefficient, c
p - Ambient water density, kg/m3 (1,024)
- Ambient density gradient, kg/m4.
The density gradient used should reflect the most severe stratification
condition that is likely to occur during the critical period.
The dilution D that is used in Equation B-24 can be found from Table B-5
where the field width is the width of the deposition area. For the
appropriate travel time and field width, the smaller of the two estimates
shown in the table should be used.
In Chapter B-I (Suspended Solids Deposition), the applicant is asked
to compute the long-term accumulation and the critical 90-day accumulation.
Because the critical 90-day accumulation might exceed the long-term average,
the applicant should use the more critical case when predicting sediment
oxygen demand.
Oxygen Demand Due to Resusoension of Sediments
It is more difficult to accurately predict oxygen demand due to
resuspension than due to either farfield BOD decay or a steady sediment
oxygen demand. To simplify the analysis, the approach here considers a
worst-case situation. The amount of sediment to be resuspended is equal to
the critical 90-day accumulation, which is found using the methods discussed
in the above guidance on "Suspended Solids Deposition."
B-40
-------
TABLE B-5. SUBSEQUENT DILUTIONS* FOR VARIOUS INITIAL FIELD WIDTHS AND TRAVEL TIMES
Travel
Tine (h)
0.5
1.0
2.0
4.0
8.0
12
24
48
72
96
Initial Field Width (ft)
10
2.3/5.5
" : 3.1/13
4.3/32
6.1/85
8.5/>100
10/>100
15/>100
21/>100
26A100
29/>100
50
1.5/2.0
2.0/3.9
2.7/8.5
3.7/21
5.2/53
6.3/95
8.9/>100
13/>100
15/>100
18/>100
100
1.3/1.6
1.6/2.6
2.2/5.1
3.0/11
4.1/29
5.1/50
7.1/100
10/>100
12/>100
14/>100
500
1.0/1.1
1.2/1.3
1.4/1.9
1.9/3.5
2.5/7.3
3.0/12
4.2/30
5.9/80
7.3/>100
8.4/>100
1,000
1.0/1.0
1.1/1.1
1.2/1.5
1.5/2.3
2.0/4.4
2.4/6.8
3.4/16
4.7/41
5.8/73
6.6/100
5,000
1.0/1.0
1.0/1.0
1.0/1.0
1.1/1.2
1.4/1.7
1.6/2.3
2.1/4.4
2.8/10
3.4/17
3.9/24
* The dilutions are entered in the table as N./H,, where M. is the dilution assuning a constant diffusion
coefficient, and N2 is the dilution assuming the A/3 law.
B-41
-------
For the material to remain suspended, the ambient current speed has to
be sufficiently great that the volume of water containing the resuspended
material increases over time as ambient water is entrained. It is assumed
that this process continues for up to 24 h.
The applicant should compute the oxygen depletion as a function of time
during this period. This can be done using the following relationship:
S /-k t
ADO - [
where:
ADO -. Oxygen depletion, mg/L
Sr » Average concentration (in g/m^) of resuspended organic sediment
(based on 90-day accumulation)
H - Depth of water volume containing resuspended materials, m
kr - Decay rate of resuspended sediments, O.I/day
t = Elapsed time following resuspension, h (t varies from 0 to 24 h)
D = Dilution as defined previously (generally set equal to 1).
The variable H is a function of travel time and can be predicted from:
H -lj§ (3,600 t €^1/2 B-30
where:
e^ » Vertical diffusion coefficient when resuspension is occurring
(5 cm2/sec)
t = Elapsed time following resuspension, h.
B-42
-------
The applicant should check to be sure that H does not exceed the water
depth. If it does, set H equal to the water depth.
The concentration of resuspended sediments Sr can be approximated as
the average concentration over the width of the zone of deposition. This
can be determined directly from the contour plots of sediment accumulation,
developed in response to the guidance on "Suspended Solids Deposition" in
Chapter B-I.
The applicant should calculate ADO for 3-h increments for a period of
up to 24 h. The results can be tabulated as shown below. Data and
calculations should be included in the application.
t (h) DO (mq/Ll
0 0
3
6
9
12
15
18
21
24 predictions
Most often, a maximum depletion will occur somewhere in the 24-h period, with
depletions decreasing for larger travel times.
B-43
-------
B-V. SUSPENDED SOLIDS CONCENTRATION FOLLOWING INITIAL DILUTION
The concentration of suspended solids at the completion of Initial
dilution should be calculated using the following equation:
SS - SS
SSf - SSa
where:
SSf - Suspended solids concentration at completion of initial dilution,
mg/L
SSa « Affected ambient suspended solids concentration Immediately
upcurrent of the diffuser averaged over ore-half the tidal period
(12.5 h) and from the diffuser port depth to the trapping level,
mg/L
SSe - Effluent suspended solids concentration, mg/L
Sa = Initial dilution (flux-averaged).
The maximum change, AS, due to the effluent can be computed as follows:
AS = SSe/Sa B-32
where the terms are as defined above. Equation B-32 is appropriate as long
as the effluent suspended solids concentration is much greater than the
background concentration. During spring runoff in some estuaries, the
background suspended solids concentration may exceed the effluent concentra-
tion. In these cases, the final suspended solids concentration will be
below the background concentration.
B-44
-------
U.S. EPA requires data for periods of maximum stratification and for
other periods when discharge characteristics, oceanographic conditions, water
quality, or biological seasons indicate more critical situations exist. The
critical period generally occurs when water quality standards are most
likely to be violated. If the standard is expressed as a maximum numerical
limit, the critical period would be when the background concentrations are
highest and the initial dilution is low. If the standard is expressed as a
numerical difference from background, the critical period would be when
effluent concentrations are high and initial dilution low. When the
standard is expressed as a percent difference from background, the critical
period could occur when background concentrations are low.
Because effluent suspended solids concentrations can vary with
discharge flow rate, the concentration at the completion of initial dilution
should be computed for the minimum, average dry- and wet-weather, and maximum
flow rates, using the associated suspended solids concentration. The range
and average effluent concentrations should be provided in the application by
month, unless locally applicable standards require compliance over shorter
durations. This information should be available from operating records.
The selection of an appropriate background suspended solids concentra-
tion may be difficult due to a general lack of data. A common problem for
coastal sites is that measurements may be available only at the mouths of
large rivers. Concentrations are often higher at such locations than
farther offshore because of the solids contribution from runoff. Selected
values of background suspended solids concentrations are shown in Table B-6.
Suspended solids background data should be obtained at control stations, at
the ZID boundary of the existing discharges, and at stations between the
ZID-boundary and control stations. Data should be collected over the tidal
cycle and at several depths so the average concentration over the height-of-
rise of the plume over the tidal cycle can be calculated. This value should
be used in Equation B-31.
B-45
-------
TABLE 8-6. SELECTED BACKGROUND SUSPENDED SOLIDS CONCENTRATIONS
Suspended Solids
Water Body Concentration, mg/L
Cook Inlet, AK 250-1,280
Southern California Bight 0.7-60
Pacific Ocean near San Francisco, CA 1-33
Broad Sound, MA 18.6-25.2
Massachusetts Bay near South Essex 1.2-30.5
New Bedford Harbor, MA 0.4-6.1
East River, NY 6.0-25.6
Ponce, PR (near shore) 13.5
Puget Sound, WA 0.5-2.0
Outer Commencement Bay, Tacoma, WA 33-51
Commencement Bay near Puyallup River, WA 23-136
Tacoma Narrows, WA 33-63
Note: Data are from 301(h) applications.
B-46
-------
Compliance with the water quality standard can be determined directly
if the standard is expressed in the form of suspended solids concentrations.
If only a general standard exists, the maximum increase due to the effluent
should be computed. If the increase is less than 10 percent, then no
substantial effect in the water column is likely. However, seabed deposition
could still be substantial depending on the mass emission rate of suspended
solids and ambient currents at the discharge site, and thus should be
evaluated.
The water quality standards may also specify limitations on the level
of suspended solids removal. For example, California has a requirement that
75 percent of the solids entering POTWs must be removed. Compliance with
this standard can be determined by estimating the average removal efficiency
for each month based on the average monthly influent and effluent suspended
solids concentrations. The removal efficiency should be equal to or greater
than the required percentage in all months. The applicant should include
the monthly average influent and effluent suspended solids concentrations
along with the computed removal efficiencies.
B-47
-------
B-VI. EFFLUENT pH AFTLi INITIAL DILUTION
The calculation of effluent pH following initial dilution is chemically
more sophisticated than other chemical calculations in this document. This
appendix details the basis for Table 1 in the main text showing the ranges
of probable effluent pH following initial dilution. The method for
calculating effluent pH following initial dilution is described herein,
assuming that all of the required variables are known. These variables
include initial dilution and the temperature, salinity, pH, and alkalinity of
the effluent and the receiving water. Effluent and receiving water
temperature, salinity, and pH are normally measured. The (usually critical)
initial dilution is routinely calculated as part of either the Section
301(h) waiver application process or the Section 301(h) permit renewal
process. However, neither the alkalinity of the receiving water nor that of
the effluent is usually measured. The alkalinity of seawater is relatively
constant, however, at a value of 2.3 meq/L (Stumm and Morgan 1981). The
alkalinity of effluent varies from 0.1 to 6.0 meq/L.
The method described herein predicts pH at the completion of initial
dilution of an effluent-receiving water mixture. Because the initial
dilution process occurs over a short time period, mixing is considered to
occur in a closed system. Also, in stratified receiving waters, the
wastewater plume is often trapped below the surface. Thus, the plume does
not equilibrate with the atmosphere, and carbon dioxide exchange between the
atmosphere and mixture is considered negligible. This method is useful for
the calculation of pH, alkalinity, and total inorganic carbon concentration
in the plume after initial dilution.
The pH of the effluent receiving water mixture is calculated using the
equations for aqueous carbonate equilibrium in a closed system (Stumm and
Morgan 1981). For this condition, the five equations that describe the
relationships between pH, the carbonate species, and alkalinity are:
B-48
-------
[HC03-]/[H2C03*] = K!
[C032-]/[HC03-] - K2
[OH'] - Kw
[HC03~] + [C032-]
Alkalinity - [HC03'] + 2[C032'] + [OH'] - [H+]
B-33
B-34
B-35
B-36
B-37
where:
[H2C03*] = The sum of aqueous C02 and true H2C03 concentrations
Cf - Total carbonate concentration.
The carbonate species can also be expressed in terms of ionization fractions
on, 01, and 02:
[H2C03*] = CT
[HC03-] = CT
[C032-] = CT
B-38
B-39
B-40
where:
°b
-1
B-41
-1
B-42
B-49
-------
"
Substituting the hydroxide -hydrogen Ion relationship and ionization
fractions Into the alkalinity equation yields:
Kw +
Alkalinity - CT (a, + 2aJ + —7- - [H*] B-44
' • * " +
Because total carbonate is conserved and oq and erg are functions solely of
pH, the above equation has only one variable: hydrogen ion concentration.
The model solves the equation to determine the pH of the effluent-receiving
water mixture. The steps involved in the calculations are listed below:
• Determine input data
• Calculate ion product of water,
-------
• Use a stepping procedure to find pH based on the competed
values for total carbonate and alkalinity of the effluent-
receiving water mixture
• Record results.
The Ion product and dissociation constants are calculated for the appropriate
temperature and salinity based on the equations given below. The equations
for the receiving water have been revised so that salinity (in ppt) can be
used.
For effluent:
3|4°7t7 + 0.03279T - 14.8435 (Kelts and Hsu 1978, p. 300) B-45
pK - ***• + 0.02379T - 6.498 (Kelts and Hsu 1978, p. 300) B-46
4 471 0
PKW = ' j* + 0.01706T - 6.0875 (Stumm and Morgan 1981, p. 127) B-47
For receiving water and the effluent-receiving water mixture:
pKj = 3l4°4'7 + 0.03279T - 14.712 - 9.1575S1/3 B-48
(Stumm and Morgan 1981, p. 205)
pK2 => 2l9°2'4 + 0.02379T - 6.471 - 0.3855S1/3 B-49
(Stumm and Morgan 1981, p. 206)
PKW - 3l441>0 + 2.241 - 0.0925S1/2 B-50
(Dickson and Riley 1979, p. 97)
B-51
-------
where: .
T - Temperature in degrees Kelvin
S - Salinity in ppt.
The receiving water equations are valid for salinities down to about 10 ppt.
B-52
-------
B-VII. LIGHT TRANSMITTANCE
Increased suspended solids concentrations associated with municipal
discharges can cause a decrease In light penetration within the water column.
Reductions in light penetration can result in a decrease in phytoplankton
productivity as well as a reduction in the areal distribution of attached
macroalgae such as kelp. Therefore, several states have enacted regulations
governing the allowable levels of interference with light transmittance.
The evaluation of light transmittance may require the measurement of
one or more water clarity variables and a comparison of values recorded in
the vicinity of the outfall with those recorded in control areas. Variables
that are widely measured to assess light transmittance include turbidity,
Secchi disc depth, beam transmittance, and downward irradiance. While many
of the state requirements are very specific in terms of the light transmit-
tance measurements, others leave the selection of the sampling methods to
the discretion of the applicant.
Turbidity is a measure of the optical clarity of water, and many
standards are written in terms of Nephelometric Turbidity Units (NTU).
Measurements are made with a nephelometer, which provides a comparison of the
light-scattering characteristics of the sample with a standard reference.
Differences in the optical design of nephelometers can cause differences in
measured values even when calibrated against the same turbidity standard.
For this reason, caution must be exercised when comparing measurements of
turbidity made from different field sampling programs.
A Secchi disc is used to make visual observations of water clarity.
Records of the depth at which the Secchi disc is just barely visible can be
used to make comparisons of light transmittance among sampling sites.
Measurements of Secchi disc depth are probably the most widely used means of
estimating light penetration. The Secchi disc is easy to use, is accurate
B-53
-------
over a wide range of conditions, and can be used to estimate the attenuation
coefficients for collimated and diffuse light and, therefore, to estimate
the depth of the euphotlc zone. However, since a wastewater plume may be
held below the upper regions of this zone during periods of stratification,
Seech1 disc measurements may not be appropriate under all conditions.
Beam transmittance is measured with a transmissometer and 1s a measure
of the attenuation of a collimated beam of artificial light along a fixed
path length (usually 1m). The attenuation is caused by suspended and
dissolved material as well as the water itself. These measurements,
therefore, provide information about both the absorption and scattering
properties of the water. The attenuation of a collimated beam of light in a
water path is described by the Beer-Lambert law:
Td = e'od B-51
where:
T(j - The proportion of light transmitted along a path of length d, m
a - Light attenuation coefficient, m"1.
Measurements of beam transmittance are made in situ at any depth.
The intensity and attenuation of daylight penetration are measured with
an irradiance meter, which utilizes a photovoltaic cell to record incident
light levels. Measurements are made just below the surface and at selected
depth intervals throughout the water column so that light attenuation over
specific depths can be determined. Unlike beam transmittance measurements,
irradiance measurements are influenced by sunlight as well as surface
conditions.
Empirical relationships can be derived among the light transmittance
variables measured by these methods, which permits the estimation of one
based on recorded values of another. These values can also be predicted
B-54
-------
from suspended solids concentrations. The derivation of these relationships
from existing data, in some instances, may be sufficient to allow for the
demonstration of compliance with state standards. Existing data can also be
used to predict the transparency characteristics in the vicinity of an
improved discharge. Alternatively, a sampling program can be designed to
assess compliance with light transmittance standards based on such empirical
relationships.
Where standards are written in terms of maximum allowable turbidity or
turbidity increase, predicted turbidity in the receiving water at the
completion of initial dilution can be used to demonstrate compliance. By
treating turbidity as a conservative variable, the turbidity in the
receiving water at the completion of initial dilution can be predicted as:
T T x Te " Ta B-52
Tf • Ta * -IT"
where:
Tf «• Turbidity in receiving water at the completion of initial dilution,
typically NTU or Jackson Turbidity Units (JTU)
Ta -Ambient or background turbidity
Te - Effluent turbidity
Sa - Initial dilution.
Initial dilution can be predicted based on the methods presented in
Appendix A. Equation B-52 can be used, then, to directly evaluate compliance
with standards written in terms of maximum allowable turbidity or a
turbidity increase.
Laboratory experimental work can also be used in lieu of field sampling
to demonstrate compliance with standards written in terms of an allowable
B-55
-------
turbidity Increase. These analyses consist of determining the turbidity of
a seawater-ef f 1 uent mixture prepared In the sane proportions corresponding
to the predicted concentrations following initial dilution. Experiments
should be conducted to simulate worst-case conditions. Simulations of
expected receiving water turbidity should be made for periods of highest
effluent turbidity (greatest suspended solids concentrations) as well as
lowest initial dilutions. Values of the initial turbidity of the seawater,
the effluent mixture, and the simulated dilution should accompany all test
results.
By deriving a relationship between turbidity and Seech 1 depth and
utilizing the method of prediction for turbidity in the receiving water
following initial dilution (Equation B-52), compliance with state standards
written in terms of Secchi depth can be evaluated. Secchi disc and
turbidity can be related in the following manner. Assume that the extinction
coefficient of visible light (a) is directly proportional to turbidity (T)
and inversely proportional to Secchi disc (SO), or:
a = kj T B-53
and
B-54
where kj and k£ are constants which need not be specified since they cancel
out in further calculations. These two relationships have theoretical
bases, as discussed in Austin (1974) and Graham (1966). Combining those two
expressions, the relationship between Secchi disc and turbidity becomes:
B-55
When state standards are written in terms of Secchi disc, it is convenient
to combine Equations B-52 and B-55 to yield:
B-56
-------
j. SDo S°a R «
SDf - SDa * -«§ » " B-56
or
SO
e
_
SO. SDa a SDa
-1
B-57
where:
SDf - Minimum allowable Secchi disc reading In receiving water such that
the water quality standard Is not violated
SDa - Ambient Secchi disc reading
Sa - Minimum initial dilution that occurs when the plume surfaces
SDe - Critical Secchi disc depth of effluent.
In this manner, the critical effluent Secchi depth (SDe) can be
calculated. An effluent reading higher than this value indicates that
standards will not be violated. This method of predicting the final Secchi
depth in the receiving water can be utilized to provide an estimate of the
effect of the wastewater discharge on the receiving water. This method
should only be used where the standard is exclusively in terms of the
acceptable decrease in the Secchi depth.
Values of the critical effluent Secchi depth (SDe) calculated using
Equation B-57 are presented in Table B-7. In this example, the water
quality standard for the minimum Secchi visibility is 1 m (3.3 ft).
Effluent having a Secchi depth greater than those presented for the selected
ambient conditions and initial dilution will not violate the clarity
standard of the example receiving water. Primary effluents typically have
B-57
-------
TABLE B-7. CALCULATED VALUES FOR THE CRITICAL EFFLUENT SECCHI DEPTH (cm)
FOR SELECTED AMBIENT SECCHI DEPTHS, INITIAL DILUTIONS, AND A WATER
QUALITY STANDARD FOR MINIMUM SECCHI DISC VISIBILITY OF 1 m
Initial
Dilution
10
20
40
60
100
2
18
10
5
3
2
Ambient
3
14
7
4
2
1
Secchi
4
13
7
3
2
1
Death (nO
5
12
6
3
2
1
10
11
6
3
2
1
B-58
-------
Secchi disc values of 5-30 cm (2-12 in). For this case, with an,initial
dilution greater than 40 and an ambient Secchi depth of 2 m (6.6 ft) or
greater, these calculations indicate that the standard would not be violated.
Since Secchi disc measurements are made from the water surface
downward, critical conditions (in terms of the Secchi disc standard) will
occur when the initial dilution is just sufficient to allow the plume to
surface. It is notable that maximum turbidity or light transmittance
impacts of a wastewater plume will occur when the water column is stratified,
the plume remains submerged, and initial dilution is a minimum. Under these
same conditions, however, Secchi disc readings night not be altered at all,
if the plume is trapped below the water's surface at a depth exceeding the
ambient Secchi disc depth.
The ability to relate measurements of turbidity to the attenuation
coefficient (a) for collimated light has been demonstrated by Austin (1974).
The attenuation coefficient can be expressed in terms of turbidity as:
a = k x JTU B-58
where:
JTU - Turbidity, JTU
k - Coefficient of proportionality.
Combining Equations B-51 and B-58, turbidity can be expressed as:
B-59
where:
T(j = Fraction of beam transmittance over distance d.
B-59
-------
The coefficient of proportionality (k) takes on values 0.5-1.0. Therefore,
to utilize these relationships for demonstrating compliance with a turbidity
standard based on existing light transnrittance data, the value of k must be
determined empirically. This requires simultaneous measurements of beam
transmittance and determination of turbidity covering the complete range of
existing light transmittance records. If data are not available, the "k"
value can be set equal to 1 as a conservative estimate.
Where a relationship between suspended solids concentration and beam
transmittance data at a particular site can be derived, the suspended solids
concentration at the completion of initial dilution from Equation B-31 can
be used to predict compliance with standards written in terms of light
transmittance.
B-60
-------
B-VIII. OTHER WATER QUALITY VARIABLES
Other variables for which water quality standards may exist Include
total dissolved gases, coliform bacteria, chlorine residual, temperature,
salinity, radioactivity, and nutrients. Variables concerned with aesthetic
effects that also may be included are color, floating material, taste and
odor, and hydrocarbons (i.e., grease and oil). For most dischargers,
temperature, salinity, and radioactivity standards are unlikely to be
violated. Aesthetic effects are more likely to occur when the plume
surfaces and the dilution is low. Compliance with aesthetic standards can
best be checked by field observations at the discharge site and along the
shore.
TOTAL DISSOLVED GASES
Several states have a limit for total dissolved gases of 110 percent of
saturation. Supersaturation of dissolved gases is not considered to be a
likely problem for municipal wastewater discharges to the marine environment
and is not discussed further.
CHLORINE RESIDUAL
Chlorine residual standards may be expressed as a concentration limit
in the effluent or as a maximum concentration in the receiving water at
the completion of initial dilution. If the effluent is not chlorinated, no
further information is required. If the standard is expressed as an
effluent limit, chlorine residual data from treatment plant operating
reports, or other sources, should be presented in the application. If no
data are available, then the procedure for chlorination, including the
compound used, quantity, and occurrence of any operational problems, should
be described. If the standard is expressed as a maximum limit at the
B-61
-------
completion of Initial dilution, the concentration in the receiving^ water,
assuming the ambient concentration is 0.0 mg/L, can be estimated as follows:
Clf = C1e/Sa B-60
where:
Clf - Chlorine residual at completion of initial dilution, mg/L
Cle - Chlorine residual in effluent, mg/L
Sa - Lowest flux-averaged initial dilution.
As a worst-case approach, the maximum observed chlorine residual in the
effluent should be used with the lowest dilution. If violations are
predicted, the applicable water quality standard may require information on
the frequency of occurrence.
NUTRIENTS
Standards can be expressed as maximum receiving water concentrations of
total nitrogen or total phosphorus or as a general prohibition on amounts
that would cause objectionable aquatic life. In general, for small
discharges when the initial dilution is large, nutrients are not likely to
cause problems. Appropriate state agencies should be contacted to ascertain
if algal blooms, red tides, or other unusual biological activity have
occurred near the discharge site in the past.
Receiving water and effluent nutrient data can be used to estimate
concentrations at the completion of initial dilution. For screening
purposes, the nutrients can be treated as conservative variables. The
concentration is estimated as follows in a similar manner to suspended
solids:
B-62
-------
c - c
--1 B-61
where:
Ca • Affected ambient concentration immediately upcurrent of diffuser,
mg/L
Ce • Effluent concentration, mg/L
Sa • Initial dilution (flux-averaged)
Cf - Concentration at the completion of initial dilution, mg/L.
The predicted concentration can then be compared to the state standard.
Because water quality criteria are often prescribed as maximum values
not to be exceeded following initial dilution, it is useful to rearrange the
above equation to express the maximum allowable effluent concentration as
follows:
(Ce)max - Ca. + (Sa)min (Cc-Ca) B-62
where:
(Ce)max - Maximum allowable effluent concentration such that water
quality criteria are not exceeded
Cc • Applicable water quality criterion
(Sa)min = Minimum expected initial dilution.
The maximum observed effluent concentration can then be compared to the
predicted allowable concentration. This approach can be used for any
conservative constituent. Thus, if other specific limits exist such as
B-63
-------
for color, effects due to the discharge can be determined as shown in
Equations B-61 and B-62.
COLIFORM BACTERIA
Standards may exist for total or fecal collform bacteria or enterococci
and are usually expressed as a mean or median bacterial count and a maximum
limit that cannot be exceeded by more than 10 percent of the samples. If
the effluent is continuously disinfected using chlorination or an equivalent
process, analyses for coliform bacteria may be needed only to verify the
effectiveness of disinfection. If disinfection is done part of the year,
analyses should be representative of conditions when the effluent is not so
treated. The chemicals used, quantities, and frequency of use should be
provided along with a discussion of the reliability of the system.
The coliform bacteria count at the completion of initial dilution due
to the discharge can be estimated as follows:
Bf = Be/Sa B-63
where:
Be - Effluent coliform bacteria count, MPN/100 ml
Sa - Initial dilution.
As a conservative approach, the maximum effluent count and the lowest
initial dilution should be used. If onshore currents occur only during a
particular season, the coliform count at the completion of initial dilution
can be estimated using the lowest initial dilution appropriate for that
season. Effluent coliform data should be submitted to support the appli-
cant's values. The predicted value can be compared with the appropriate
standard at the ZID boundary. This value can also be used to estimate the
bacterial concentration at specific locations away from the ZID.
B-64
-------
Because different limits may apply to specific areas (e.g., shellfish
harvesting areas, beaches, diving areas), the maximum bacterial count at a
specified distance from the discharge may be of concern. This bacterial
count can be estimated in a manner analogous to the estimation of the BOO
exerted as the wastefield spreads out from the ZID. The maximum bacterial
count at the centerline of the wastefield can be estimated as a function of
distance from the discharge as follows:
Bf ' Ba
Bx ' Ba * T^ B'64
where:
Bx - Bacteria count at distance x from ZID, #/100 ml.
Ba - Affected ambient bacteria count immediately upcurrent of diffuser,
#/100 mL
Bf a Bacteria count at completion of initial dilution, #/lQQ ml
Ds = Dilution attained subsequent to initial dilution at distance x
05 = "Dilution" due to dieoff of bacteria caused by the combined
effects of exposure to seawater and sunlight.
when x - 0, Bx - Bf. In cases where the background bacterial count is
negligible or the effect of the discharge alone is desired, the terms for
the ambient bacterial count can be dropped, simplifying Equation B-64 to:
B*'5A
Values for subsequent dilution as a function of 12e0t/B2 in Figure B-5.
Guidance is included in Chapter B-III ("Farfield Dissolved Oxygen Demand")
B-65
-------
on methods for estimating subsequent dilution for sites located in^ narrow
estuaries or bays.
The decay rate of bacteria in the ocean is Influenced by water
temperature, incident light, salinity, and other factors. As a conservative
estimate, the minimum decay rate should be used. If no violations would
occur, then further calculations are not needed. Flocculation and sedimen-
tation can cause an apparent decrease in coliform count in the water column,
but the bacteria are retained in the sediment. Thus, this process is not
included in the above approach. If the applicant has information indicating
that the decay rate at the discharge site should be a different value, the
revised decay rate may be used. The evidence for the revised decay rate,
including any data or results of laboratory tests, should be included in the
application.
In this report, dieoff due to the combined effects of exposure to
saltwater and exposure to sunlight only are considered. The dieoff due to
exposure to saltwater, Dsw, and the dieoff due to exposure to sunlight, Ds-j,
are (Gameson and Gould 1975):
Dsw = exp(kswt) B-66
Osl = exp[al(t)] B-67
where:
ksw - Bacteria decay rate due to exposure to saltwater, 1/h
a - Constant, m2/MJ
I(t) = Total intensity of sunlight received by bacteria during the
travel time, MJ/m2
t = Travel time, h.
B-66
-------
The bacteria dieoff due to the combined effects of saltwater and sunlight is
Db " Dsw°s1- Gameson and Gould (1975) indicate that a • 1.24 m2/MJ in situ
for Dorset, England seawater. The total intensity of sunlight received at
the water surface can be measured, or estimated using site-specific data or
general methods (Wallace and Hobbs 1977). If the wastefield is submerged,
then the calculation of the total sunlight received should reflect the
effect of turbidity on light transmission from the sea surface to the top of
the wastefield.
The bacteria decay rate due to the exposure to saltwater Is known for
both coliform bacteria and enterococcus bacteria. For coliform bacteria,
ksw - 2.303 exp[(0.0295T - 2.292)2.303] / h B-68
where T - water temperature (° C), based on field measurements at Bridport
(Dorset, England) (Gameson and Gould 1975). The enterococcus bacteria dieoff
rate due to exposure to saltwater is:
ksw - 0.5262 / (24 h) B-69
at a temperature of 20° C (Hanes and Fragala 1967). [It should be noted
that Hanes and Fragala (1967) determined that ksw for coliform bacteria is
0.0424/h at 20° C, a value slightly smaller than the value of 0.0457/h at
20° C based on the formula from Gameson and Gould (1975).]
The estimated coliform count at the location of interest should be
compared to the applicable standard. If a violation is predicted, the water
quality standards may require that the approximate frequency should be
discussed based on the percentage or likelihood of currents transporting the
wastefield in the direction of interest.
B-67
-------
REFERENCES
American Public Health Association. 1985. Standard methods for the
examination of water and wastewater. APHA, Washington, OC. 16th Edition.
1268 pp.
Austin, W.R. 1974. Problems in measuring turbidity as a water quality
parameter. EPA-600/4-74-004. pp. 23-54. In: Proc. on Seminar on
Methodology for Monitoring the Marine Environment.
Baumgartner, D. 1981. Environmental Protection Agency, Office of Research
and Development, presentation at 301(h) Task Force Meeting. 13 March 1981.
Brooks, N.H. 1960. Diffusion of sewage effluent in an ocean current, pp.
246-267. In: Proc. of the 1st International Conference on Waste Disposal
in the Marine Environment, University of California, Berkeley, CA, July
1959. Pergamon Press, Elmsford, NY.
Dickson, A.G., and J.P. Riley. 1979. The estimation of acid dissociation
constants in seawater media from potentiometric titrations with strong base;
I. The ionic product of water-^. Mar. Chem. 7:89-99.
Gameson, A.L.M., and D.J. Gould. 1975. Effects of solar radiation on the
mortality of some terrestrial bacteria in seawater. pp. 209-219. In:
Discharge of Sewage from Sea Outfalls. Proc. of an International Symposium
held at Church House, London, 27 August to 2 September 1984. A.L.M. Gameson
(ed). Pergamon Press, Oxford, UK.
Grace, R. 1978. Marine outfall systems planning, design, and construction.
Prentice-Hall, Inc., Englewood Cliffs, NO. 600 pp.
Graham, J.J. 1966. Secchi disc observations and extinction coefficients in
the central and eastern North Pacific Ocean. Limnol. Oceanogr. 2:184-190.
Green, E.J., and D.E. Carritt. 1967. New tables for oxygen saturation of
seawater. J. Mar. Res. 25:140-147.
Hanes, N.B., and R. Fragala. 1967. Effect of seawater concentration on
survival of indicator bacteria. J. Water Pollut. Control Fed. 39:97-104.
Hendricks, T.J. 1987. Development of methods for estimating the changes in
marine sediments as a result of the discharge of sewered municipal waste-
waters through submarine outfalls. Part I - sedimentation flux estimation.
Final Report. Prepared for U.S. Environmental Protection Agency, Environmen-
tal Research Laboratory, Newport, OR. Southern California Coastal Water
Research Project Authority, Long Beach, CA. 65 pp.
B-68
-------
Herring, J.R., and A.L. Abati. 1978. Effluent particle dispersion.
pp. 113-125. In: Coastal Water Research Project Annual Report. 'Southern
California Coastal Water Research Project, El Segundo, CA.
Hyer, P.V., C.S. Fang, E.P. Ruzecki, and W.J. Hargis. 1971. Hydrography
and hydrodynamics of Virginia estuaries. II. Studies of the distribution
of salinity and dissolved oxygen in the upper York system. Virginia
Institute of Marine Science, Gloucester Point, VA. 167 pp.
Kelts, K., and K.J. Hsu. 1978. p. 295+. In: Lakes: Chemistry, Geology,
Physics. Lerman, A. (ed). Springer, New York, NY.
Myers, E.P. 1974. The concentration and isotrophic composition of carbon
in marine sediments affected by a sewage discharge. Ph.D. thesis.
California Institute of Technology, Pasadena, CA. 179 pp.
Stumm, W., and J.J. Morgan. 1981. Aquatic chemistry. John Wiley and Sons,
Inc., New York. 780 pp.
Tetra Tech. 1982. Revised Section 301(h) technical support document.
EPA-430/9-82-011. U.S. Environmental Protection Agency, Washington, DC.
Tetra Tech. 1987. A simplified deposition calculation (DECAL) for organic
accumulation near marine outfalls. Final Report. Prepared for U.S. Environ-
mental Protection Agency, Office of Marine and Estuarine Protection,
Washington, DC. Tetra Tech, Inc., Bellevue, WA. 49 pp. + appendices.
Wallace, J.M., and P.V. Hobbs. 1977. Atmospheric science: an introductory
survey. Academic Press, New York NY. 467 pp.
B-69
-------
APPENDIX C
BIOLOGICAL ASSESSMENT
-------
APPENDIX C
BIOLOGICAL ASSESSMENT
Because benthic infauna are sedentary and must adapt to pollutant
stresses or perish, this assemblage is often used to define the spatial
extent and magnitude of biological impacts in the vicinity of sewage dis-
charges. The general changes in benthic community structure and function
that occur under conditions of organic enrichment of the sediments (e.g.,
due to municipal sewage effluent) have been well documented (Pearson and
Rosenberg 1978). Slight to moderate enrichment results in slight increases
in numbers of species, abundances, and biomass of benthic communities (see
Figure 3 in main text), while species composition remains unchanged. As
enrichment increases, numbers of species decline because less tolerant
species are eliminated. The total abundance of organisms increases as a few
species adapted to disturbed environments or organically enriched sediments
become very abundant. When enrichment levels are optimal for those few
species, they become extremely abundant and overwhelmingly dominate the
benthic community (corresponding to the "peak of opportunists" shown in
Figure 3). Biomass generally decreases, however, because many of those
opportunistic species are small. Further organic enrichment of the
sediments drastically reduces the number of species and abundances of
benthic organisms, as conditions become intolerable for most taxa.
Because the model developed by Pearson and Rosenberg (1978) has been
shown to be valid in many benthic environments, it is often instructive to
examine the abundances of species that the authors identify as opportunistic
or pollution-tolerant. Those data, in conjunction with the applicant's data
on numbers of species, total abundances, and biomass at stations in the
vicinity of the outfall, are often sufficient to determine the relative
degree of impact within and beyond the ZID.
C-l
-------
Comparable models that describe changes In the structure and function
of plankton and demersal fish communities in organically enriched receiving
environments have not yet been developed. However, it may be instructive to
examine the scientific literature that is available for the biogeographic
region in which the outfall is located. That literature often contains
information describing the responses of the local fauna and flora to organic
materials and other pollutants, and identifying opportunistic and pollution-
tolerant species. Such information is extremely useful for interpreting
data collected in the vicinity of the outfall.
A variety of analytical tools may be used to conduct biological
comparisons for Section 301(h) applications. Applicants may analyze the
data graphically or statistically, or may use other mathematical tools such
as multivariate analyses (e.g., classification and ordination procedures).
Graphical analyses can be especially useful for presenting data in an easily
understood format. In Figure C-l, data on numbers of species in each
replicate sample at stations in the vicinity of an outfall have been plotted
to show the range of reference values in comparison with values at within-
ZID, ZID-boundary, nearfield, and farfield stations. These data may be
tested statistically to determine those test stations at which mean values
differ from mean values at either or both reference stations. But even
without such tests, the data in Figure C-l clearly indicate that a gradient
of effects occurs near the outfall. Relative to reference conditions,
numbers of species are depressed at the within-ZID and downcurrent ZID-
boundary stations, and may be depressed at the nearfield and upcurrent ZID-
boundary stations.
Graphical analyses are especially useful for presenting data on the
physical characteristics of the habitat. For example, it is often in-
structive to plot water column or substrate characteristics in relation to
distance from the outfall (see Figures C-2 and C-3). Gradients of effects
(as in Figure C-3) are often revealed in such simple presentations. An
especially useful method for presenting data on sediment grain size
distributions that has proven useful in analyses of 301(h) data was
developed by Shepard (1954). Sediments are classified by the proportions of
C-2
-------
50n
o
I
CO
UJ
H
O
O.
UJ
OC
OC
UJ
0-
(0
UJ
o
UJ
o.
(0
u.
o
OC
UJ
CD
40-
30-
20-
10-
RANGEOF
h REFERENCE
CONDITIONS
NET
CURRENT^
DIRECTION
REFERENCE REFERENCE
1 2
ZID-
BOUNDARYt
WITHIN
ZIO
ZID-
BOUNDARY2
NEARFIELO
FARFIELD
STATION
Figure C-1. Numbers of species collected in replicate benthic grab samples at stations in the
vicinity of the outfall.
-------
34-
33-
Q.
IX
z
Zj
<
(0
32-
31-
30
REFERENCE REFERENCE ZID- WITHIN- 210
t 2 BOUNDARY 1 210 BOUNDARY 2
I I
NEARFICLO FARFIELD
STATION
Figure C-2. Salinity at stations in the vicinity of the outfall.
-------
o
ffi
DC
<
o
Z
<
5
i
tn
O
1.0-
o.o
REFERENCE REFERENCE ZIO- WITHIN- ZIO-
I 2 BOUNDARY 1 ZID BOUNDARY 2
NEARFIELO
FARFIELD
STATION
Figure C-3. Total organic carbon content of the sediments at stations in the vicinity of the
outfall.
-------
their three major grain-size categories (Figure C-4)
Sand, silt, and clay are often the most useful categories. However, the
gravel, sand, and mud (silt plus clay) categories are useful where sediments
are relatively coarse. [See Shepard (1963) for information on sediment
grain size scales.]
Statistical tests are among the most effective tools for comparing
biological communities among stations. A variety of statistical tests are
available, the most widely used of which is one way analysis of variance
(ANOVA). ANOVA and other statistical tests have been used extensively for
biological comparisons in the 301 (h) program, but they have often been used
improperly. For this reason, procedures for conducting statistical com-
parisons using biological data are discussed briefly below. Applicants are
encouraged to consult references on biostatistics (e.g., Zar 1974; Sokal and
Rohlf 1981) for more specific guidance on the application of these pro-
cedures.
The use of one way ANOVA for biological comparisons is preferred
because ANOVA is an efficient and robust test. ANOVA compares the mean
values of a given variable among stations (or groups of stations) for the
purpose of detecting significant differences at a predetermined probability
level. ANOVA requires a minimum of three replicate values at each station
to estimate the mean value and associated variance.
ANOVA is a parametric test based on three assumptions: the error of an
estimate is a random normal variate, the data are normally distributed, and
the data exhibit homogeneous variances. Corrections for the first are not
easily achieved, and an erroneous assumption can greatly affect the results
of the test. Fortunately, error estimates in survey data are usually
independent.
ANOVA is relatively robust with respect to the assumption that the data
are normally distributed. Substantial departures from normality can occur
before the value of the F-statistic is affected greatly (Green 1979). For
C-6
-------
SAND
NEARFIELO
REFERENCE 2
Z1D-BOUNDARY 1
REFERENCE 1
FARFIELD
WITHIN-ZID
2ID-BOUNDARY2
SILT
CLAY
Figure C-4. Sediment grain size characteristics at stations in the
vicinity of the outfall.
C-7
-------
this reason, tests for normality are not usually conducted before data are
analyzed using ANOVA.
The third assumption, that variances are homogeneous, is critical to
execution of ANOVA. Heterogeneous variances can greatly affect the value of
the F-statistic, especially in cases where the statistical design is
unbalanced (i.e., where numbers of replicate values vary among the stations
or station groups being tested).
Several tests are available to determine whether variances are homo-
geneous. The Fmax test (see Zar 1974; Sokal and Rohlf 1981) and Cochran's C
test (Winer 1971) are both appropriate, although the latter is preferred
because it uses more of the information in the data set. Bartlett's test is
not recommended because it is overly sensitive to departures from normality
(Sokal and Rohlf 1981).
When sample variances are found to differ significantly (P<0.01), a
transformation should be applied to the data. [A more conservative pro-
bability level (e.g., P<0.05) should be used when the statistical design is
unbalanced. ANOVA is sensitive to unbalanced statistical designs.] Sokal
and Rohlf (1981) describe several transformations that may be used. Because
ANOVA on transformed data is usually a more efficient test for detecting
departures from the null hypothesis than is the Kruskal-Wallis test (the
nonparametric analog of ANOVA), the Kruskal-Wallis test should only be used
when the appropriate transformation fails to correct for heterogeneous
variances (Sokal and Rohlf 1981). The Kruskal-Wallis test requires a minimum
of five replicate values per station because it is a test of ranks.
When ANOVA or a Kruskal-Wallis tests are performed, significant
differences (P<0.05) among individual stations or groups of stations may be
determined using the appropriate a posteriori comparison. Of most im-
portance in 301(h) demonstrations are differences among reference stations
and stations within the ZID, at the ZID boundary, and beyond the ZID. It is
primarily these comparisons upon which determination of the presence or
absence of a balanced indigenous population is based.
C-8
-------
Classification analyses (e.g., cluster analyses) have also been used
extensively in the 301(h) program. In the normal classification mode,
stations are grouped by the attributes of the assemblages that occur there
(e.g., species composition and abundance). This type of analysis is very
useful for identifying the stations that are the most similar and least
similar to one another in fauna and/or flora. Because biological communities
respond to organic materials and other pollutants, stations at which
pollutant impacts are occurring typically cluster together in interpretable
groups. Inverse classification analysis, in which taxa are grouped by the
stations at which they co-occur, is also helpful because it defines
assemblages that are characteristic of different levels and types of
pollutant impacts.
Classification analysis involves two analytical steps: calculation of
a matrix of similarity values for all possible station pairs, and grouping of
stations based on those between-station similarity values. Many similarity
indices and clustering strategies are available to perform these two tasks
(see Boesch 1977; Green 1979; Gauch 1982; Pielou 1984; Romesburg 1984).
However, only the Bray-Curtis similarity index and either the group average
clustering strategy (i.e., the unweighted pair-group method using arithmetic
averages) or the flexible sorting strategy have been used commonly in 301(h)
demonstrations. Their continued use is recommended. The Bray-Curtis index
is easily understood, and has been used widely in ecological studies.
Moreover, two comparisons of similarity indices (i.e., Bloom 1981; Hruby
1987) have shown it to be superior to many of the other commonly used
resemblance measures. Both the group average clustering strategy and the
flexible sorting strategy are recommended because they produce little
distortion of the original similarity matrix. [See Tetra Tech (1985) for
additional rationale on the use of these three indices.]
C-9
-------
REFERENCES
Bloom, S.A. 1981. Similarity indices in community studies: potential
pitfalls. Mar. Ecol. Prog. Ser. 5:125-128.
Boesch, D.F. 1977. Application of numerical classification in ecological
investigations of water pollution. EPA-600/3-77-033. U.S. Environmental
Protection Agency, Corvallis, OR. 115 pp.
Gauch, H.G. 1982. Multivariate analysis in community ecology. Cambridge
Studies in Ecology: 1. Cambridge University Press, Cambridge, UK. 298 pp.
Green, R.H. 1979. Sampling design and statistical methods for environmental
biologists. John Wiley & Sons, Inc., Mew York, NY. 257 pp.
Hruby, T. 1987. Using similarity measures in benthic impact assessments.
Environmental Monitoring and Assessment 8:163-180.
Pearson, T.H., and R. Rosenberg. 1978. Macrobenthic succession in relation
to organic enrichment and pollution of the marine environment. Oceanogr.
Mar. Biol. Annu. Rev. 16:229-311.
Pielou, E.G. 1984. The interpretation of ecological data - a primer on
classification and ordination. John Wiley & Sons, New York, NY. 263 pp.
Romesburg, H.C. 1984. Cluster analysis for researchers. Lifetime Learning
Publications, Belmont, CA. 334 pp.
Sokal, R.R., and F.J. Rohlf. 1981. Biometry. 2nd ed. W.H. Freeman & Co.,
San Francisco, CA. 859 pp.
Tetra Tech. 1985. Summary of U.S. EPA-approved methods, standard methods,
and other guidance for 301(h) monitoring variables. Final report prepared
for Marine Operations Division, Office of Marine and Estuarine Protection,
U.S. Environmental Protection Agency. EPA Contract No. 68-01-6938. Tetra
Tech, Inc., Bellevue, WA. 16pp.
Winer, B.J. 1971. Statistical principles in experimental design. 2nd ed.
McGraw-Hill Book Co., New York, NY. 907 pp.
Zar, J.H. 1974. Biostatistical analysis. Prentice-Hall, Inc., Englewood
Cliffs, NJ. 620 pp.
C-10
-------
APPENDIX 0
NAVIGATIONAL REQUIREMENTS AND METHODS
-------
CONTENTS
Page
LIST OF FIGURES iii
LIST OF TABLES iv
MONITORING STATION LOCATIONS D-l
ACCURACY LIMITATIONS D-l
POSITIONING ERROR D-4
SUMMARY OF RECOMMENDED PROCEDURES AND EQUIPMENT D-7
CANDIDATE SYSTEM SELECTION D-7
SHALLOW-WATER POSITIONING METHODS 0-11
USE OF LORAN-C D-13
SYSTEM SELECTION PROCEDURE D-14
REFERENCES D-18
ii
-------
FIGURES
Number Page
0-1 Examples of some key 301(h) monitoring station locations for
a medium-large marine municipal discharge D-2
D-2 Locations of ZID-boundary stations for selected ZID sizes D-6
D-3 Examples of differential Loran-C error ellipse orientation
at a ZID-boundary sampling station D-15
D-4 Navigation system preliminary screening criteria D-17
m
-------
TABLES
Number Page
D-l Example ZID-boundary station locations D-5
0-2 Summary of recommended systems D-9
D-3 Theoretical error ellipses of differential Loran-C for
various U.S. locations D-16
IV
-------
APPENDIX 0
NAVIGATIONAL REQUIREMENTS AND METHODS
Information presented below addresses navigational requirements and
methods for Section 301(h) dischargers. It is summarizes more detailed
discussions in Tetra Tech (1987, 1988).
MONITORING STATION LOCATIONS
Compliance with conditions of a secondary treatment variance
requires monitoring at a site-specific array of sampling locations. The
types of stations usually specified in 301(h) monitoring programs are
depicted in Figure D-l. Positioning accuracy is most critical for the
within-ZID and ZID-boundary stations (Stations ZQ, 1\, T-i in Figure D-l).
Applicants must be able to sample at a specific boundary location on any
given occasion, and to return to nearly the same location on subsequent
trips. At gradient (Gj, 63, 63, 64) and control or reference (Cj) stations,
initial accurate location is not as critical. However, it is important to
relocate these stations accurately during subsequent surveys to enable
quantification of temporal changes in the variables sampled (e.g., benthic
community characteristics). This requirement for high repeatable accuracy
also applies to stations in or near special habitats (Hj, H£). The ability
to conduct sampling at the appropriate depth contour is also very important.
Sampling programs for 301(h) typically include requirements that a bottom
sampling station can be relocated to within 10 m (32.8 ft).
ACCURACY LIMITATIONS
Both the procedures and equipment used to establish a navigational
position contribute errors that affect the overall accuracy of a fix.
Absolute or predictable accuracy is a measure of nearness to which a system
can define a position by latitude and longitude (Bowditch 1984). Repeatable
D-l
-------
o
ro
COASTAL
TREATMENT:
. ..10m "
SHELLFISH
HABITATS
KEY:
GRADIENT
H HABITAT
REFERENCE
NEARSHORE
T TRAWL
Z ZONE OF INITIAL DILUTION
30m \!L*:**!*
ZIO BOUNDARY-
,-zi
z,
• X -60m Jt-l
GI
PREDOMINANT
^
CURRENT
.gom ••
Figure D-1. Examples of some key 301 (h) monitoring station locations for a medium-large
marine municipal discharge.
-------
or relative accuracy is a measure of a system's ability to return the user
to a given position with coordinates that were previously measured with the
same system. The difference between these two accuracies can be substantial.
For example, depending on one's location in the coverage area, Loran-C has a
repeatable accuracy in offshore areas of 15-90 m (49-295 ft), but an absolute
accuracy of 185-463 m (607-1,519 ft) (Dungan 1979). In many instances,
repeatable accuracy is more important than absolute accuracy (e.g.,
retrieval of crab pots, return to desirable fishing grounds, avoidance of
underwater obstructions, and reoccupation of reference stations).
For coastal outfall monitoring, both repeatable and absolute accuracy
can be important, depending on the type of sampling site. For within-ZID
and ZID-boundary stations, both accuracies are important because sampling
stations must be located within or very near the boundary and be repeatedly
occupied during the program. For gradient, special habitat, and reference
stations, repeatable accuracy is more important than absolute geographic
location. Once such a station is established within a special habitat, it
is often necessary to return to the same site to identify temporal variations
in the previously sampled biological community. Thus, it is important to
select navigational procedures and equipment with both the absolute and
repeatable accuracies needed to meet the monitoring program objectives.
Because repeatable accuracy of navigational equipment is usually at
least 1 order of magnitude better than absolute accuracy, the latter
frequently limits the overall positioning accuracy of a sampling vessel
during coastal monitoring programs. Therefore, the following discussion
focuses on absolute accuracies that can be achieved by various procedures
and associated equipment.
Practical considerations also limit the accuracy of an offshore
positional fix. Resolution of a position to better than 1-2 m (3.3-6.6 ft)
becomes meaningless when measuring the location of a moving vessel (e.g.,
during trawling) or a vessel that is on station but pitching and rolling.
D-3
-------
Antenna movement alone usually precludes higher resolution in position
coordinates. Exceptions to this rule can occur when conditions are
unusually calm.
POSITIONING ERROR
Many factors contribute to the total error in position of the water
column or benthic sampling point. These factors include movement or drift
of the "on-station" vessel, offsets between the deployment point of sampling
equipment and the navigational system antenna, and offsets between the
deployment point and the subsurface location of the sampling or profiling
equipment, and error in the ship's initial location. Most of these factors
are site- or operationally specific, and can be estimated with varying
degrees of confidence. Because the accuracy to which the actual sampling
point is known is highly dependent on all these factors, they should be
carefully considered in both the design and conduct of monitoring programs.
A ZID-boundary error proportional to some percentage of the ZID
dimension has been selected as the controlling parameter for 301(h)
navigational requirements. Because ZID size is proportional to water depth,
the allowable error in position is thus also proportional to depth. For
example, ZID-boundary stations can be located at a distance from the
diffuser axis equal to one-half the ZID width plus 20 percent of the water
depth at mean tide level. The allowable maximum error in the location of
these stations can then be ±20 percent of the water depth. As a result, the
closest to the diffuser that sampling would occur is at the ZID boundary,
and the farthest from the diffuser that sampling would occur is 40 percent
of the water depth beyond this boundary. Nominally, however, sampling would
be performed within a distance from the ZID boundary equal to 20 percent of
the water depth. Example ZID-boundary station locations using this approach
for a variety of ZID sizes are listed in Table D-l. The ZID-boundary and
sampling station locations for discharges at the 100-, 60-, and 20-m (328-,
197-, and 66-ft) depths are shown in Figure D-2.
D-4
-------
TABLE D-l. EXAMPLE ZID-BOUNDARY STATION LOCATIONS
Average
Diffuser
Depth
(»)
100
90
80
70
60
50
40
30
20
15
10
5
3
Average
Diffuser
Diameter
(m)
4.0
3.6
3.4
3.2
3.0
2.5
2.2
2.0
1.8
1.5
1.5
1.0
0.5
ZID
Width
(m)
204.0
183.6
163.4
143.2
123.0
102.5
82.2
62.0
41.8
31.5
21.5
11.0
6.5
Recommended
Station
Location3
(•)
122.0
109.8
87.7
85.6
73.5
61.3
49.1
37.0
24.9
18.8
13.8
8.5
6.3
Recommended
Allowable
Error6
(m)
±20
±18
±16
±14
±12
±10
±8
±6
±4
±3
±3
±3
±3
a Distance from the zone of initial dilution centerline to the station,
based on 0.5 times the ZID width plus 20 percent of the average water depth
of the diffuser when over 15 m (49 ft).
b Error magnitude is equal to ±20 percent of the average diffuser depth,
when over 15 m (49 ft).
0-5
-------
3D BOUNDARY
STATION
LOCATION
100 m DEPTH
4.0 m DIFFUSER"
ERROR_J 40m
LIMIT^^ W
I
210.
BOUNDARY
-204m-
122m
^OUTFALL PIPE
, DIFFUSER
60m DEPTH
3.0 m DIFFUSER"
24m-
•*•
123m
735m
-*•
20m DEPTH
1.8 m DIFFUSER
-I*
1 m-
249
*r
Figure D-2. Locations of ZID-boundary stations for selected ZID sizes.
D-6
-------
When discharge depths are less than approximately 15 ro (49 ft), the 20
percent error allowance results in an overly restrictive positional error
[i.e., less than ±3 m (9.8 ft)]. Therefore, a positioning error of +3 m
(9.8 ft) is considered to be more appropriate when sampling station depths
are less than 15 m (49 ft). Although the percent error as a function of
water depth increases at shallower depths, this minimum error is considered
reasonable given available navigating techniques for small sampling vessels
in other than extremely calm waters. Stations beyond the ZID may be
similarly located using the 20 percent of depth rule beyond the 15-m (49-ft)
contour and the ±3-m (9.8 ft) error limitation for shallower locations. As
indicated earlier, it is recognized that the ability to reoccupy a given
site can be as important as knowing its exact geographical location.
However, relocation beyond the ZID probably will not be a problem if the same
navigational equipment used to locate ZID-boundary stations is also used
elsewhere.
SUMMARY OF RECOMMENDED PROCEDURES AND EQUIPMENT
Based on Tetra Tech's evaluation of optional positioning methods, the
systems recommended for coastal positioning include theodolites, sextants,
electronic distance measuring instruments (EDMIs), total stations, and
microwave and range-azimuth systems. Although satellite systems offer
adequate accuracy (when used in a differential mode), their use may be
limited because a sufficient number of satellites may not always be
available.
CANDIDATE SYSTEM SELECTION
The details of positioning techniques and associated equipment are
described in Tetra Tech (1987). No single system is best for all coastal
monitoring purposes. Needs vary according to the size and complexity of the
planned monitoring program, the nature of the immediate and surrounding
areas, and other navigational or surveying requirements of a municipality.
D-7
-------
Positioning techniques fall into three principal measurement categories:
• Multiple horizontal angles
Theodolite intersection
Sextant angle resection
• Multiple electronic ranges
Distance-measuring instruments
Range-range mode
Hyperbolic mode
Satellite ranging
• Range and angle
Theodolite and EDMI
Total station
Range-azimuth navigation systems
Systems within these categories that will meet or exceed the positional
accuracy' recommended herein are summarized in Table D-2. Additional
information on the recommended categories is provided below.
Multiple Horizontal Angles
In the multiple horizontal angles category, theodolites were found to
have the angular accuracies required for the maximum ranges anticipated.
Their costs range from $1,000 to $4,000 (30-sec vs. 10-sec accuracy), and
D-8
-------
TABLE 0-2. SUMMARY OF RECOMMENDED SYSTEMS
Representative9
Category Equipment
Theodolite Table B-l
Table B-2
Accuracy
10-30
±1 m (3
sec
.3 ft)
Cost Advantages
$1.000-$4.000 Traditional method.
Inexpensive. High
accuracy . Success f u 1 1 y
applied. Restricted
areas.
Oi sadvantages
Line-of-sight. TMO
manned shore stations.
Simultaneous measure-
ments. Limits on
intersection angles.
Area coverage; station
movement .
Sextant
Table B-3
+10 sec
±2 m (6.6 ft)
$1.000-12.000
EON I
Table B-4
1.5-3.0 cm
$3.500-$15,000
Total stations
Microwave
navigation
systems
Range-azimuth
systems
Satellite systems
Table B-5
Table B-6
Table B-10
Table B-9
5-7 cm
1-3 m
0.01° and 0.5 m
1-10 m
$8.000-130,000
S40.000-J90.000
$65,000-$100.000
$150.000-$300.000
(initial units)
Rapid. Easy to imple-
ment. Most widely used.
Low cost. No shore party.
High accuracy.
Extremely accurate.
Usable for other surveying
projects. Cost. Compact,
portable, rugged.
Single onshore station.
Other uses. Minimum
logistics.
No visibility restric-
tions. Multiple users.
Highly accurate. Radio
I1ne-of-sight.
High accuracy. Single
station. Circular cover-
age.
High accuracy. Minimum
logistics. Use in re-
stricted/congested areas.
Future cost. No shore
stations.
Simultaneous measure-
ment of two angles.
Target visibilities,
location, maintenance.
Llne-of-sight. Best
In calm conditions.
Limits on acceptable
angles.
Motion and direction-
ality of reflectors.
Visibility, unless
microwave. Two shore
stations. Ground wave
reflection.
Reflector movement and
directionality. Prlsn
costs.
Cost. Multiple onshore
stations. Logistics.
Security.
Single user. Cost.
Current coverage. Ini-
tial development cost.
a Table references refer to Tetra Tech (1987).
-------
they are readily available because they are widely used as a surveying
instrument. At least two theodolites, two operators, a vessel siting
target, and a three-way communications link to coordinate fixes are
required. Visibility can be a limiting factor.
By comparison, sextant angle resection can be performed using one
instrument if the vessel is stationary, or using two instruments simul-
taneously if the vessel is moving. Achievable angular accuracy of ±10 sec
is adequate, and relatively inexpensive sextants ($1,000-52,000) are readily
available. Again, visible range can be limiting. Shooting an accurate fix
from a non-stationary platform in any significant sea or swell could be more
difficult than shooting with theodolites from shore. A distinct advantage
of sextant angle resection is location of the navigators on the survey
vessel. The method generally requires highly visible shore targets and a
three-arm protractor for plotting positions.
Multiple Electronic Ranges
Positioning using multiple ranges can be accomplished with two staffed
EDMI stations. Accuracies were found to be more than adequate but ranges
were found to be marginal [if needed beyond 3 km (1.9 mi)] unless multiple
prisms are used. Because such prisms are directional, procurement of
multiple clusters for more than one direction could result in substantial
additional costs. The initial investment (i.e., without multiple prisms) is
$3,500-$5,000 each for two shorter-range units, or $8,000-$ 15,000 each for
two longer-range units. Several microwave navigation systems with more than
adequate range and sufficient accuracy are available in the $40,000-$90,000
range. Limitations include geometry of shore stations; position of the
vessel in the coverage area (i.e., crossing angle limitations); and possible
interferences due to line-of-sight obstructions, sea-surface reflective
nulls, and land-sea boundaries. The hyperbolic mode provides multiple user
capability, but at the cost of an additional shore station.
Satellite ranging holds promise because required accuracies should be
achievable in the near future. Transit satellite-based systems do not offer
D-10
-------
sufficient accuracy, except with multiple passes, and multiple passes are
impractical when a given sampling station is occupied only briefly.
Accuracies needed will undoubtedly be achievable in the future using
differential global positioning system (GPS) techniques ($10,000-$40,000 for
first units; as low as $1,000 for subsequent production models). Commercial
geosynchronous satellite networks, such as GEOSTAR, may become available at
a proposed system interrogator cost of $450 plus a monthly fee. However,
this system is in the very early stages of planning, having only recently
received FCC approval of requested frequencies. Finally, the codeless GPS
systems (SERIES or Aero Services Marine GPS System) currently under
development could be used, but at a current cost of over $250,000.
Ranoe and Angle
Systems in the range-azimuth category show great promise. Required
angular and range accuracies are available, only one shore station is
needed, and costs depend on system refinements. At the low end of the
scale, an EDMI and theodolite could be paired with a communication link for
approximately $10,000-$12,000. Total stations developed specifically for
this requirement range in cost from $8,000 for a manual station to $15,000-
$30,000 for a fully automatic station. Optical and infrared range limita-
tions apply to these systems. The three range-azimuth navigational systems
examined provide sufficient positional accuracy with a single station at
costs ranging from $65,000 for manual tracking to $70,000-$100,000 for fully
automatic tracking.
SHALLOW-WATER POSITIONING METHODS
When sampling stations are located in relatively shallow water, they
can be identified by relatively inexpensive methods (in addition to those
discussed earlier in this report). Provided the center of the ZID over the
outfall can be located (e.g., by diver-positioned surface float), an optical
range finder may be used to establish the required distances to nearby water
quality or biological sampling stations. An optical range finder is used by
simply focusing a split-image on the target float, enabling the slant
D-ll
-------
distances to the target to be read from the instrument scale. When combined
with a careful compass reading, this distance reading allows positioning of
the sampling vessel.
A survey of accuracies claimed for commercially available instruments
suggests that the ±3 m (9.8 ft) recommended minimum accuracy can be achieved
for ranges up to approximately 100 m (328 ft) from the surface target. The
Lietz Model 1200, for example, provides an accuracy of. ±1 m (3.3 ft) at
100 m (328 ft). Beyond this distance, instrumental errors increase rapidly.
For the instrument cited, a +9 m (29.5 ft) accuracy is quoted at 300 m (984
ft). The suggested U.S. list prices of optical range finders vary from $35
to $120 (Folk, L., 21 March 1985, personal communication).
An acceptable alternative method for collecting bottom samples from
desired locations in shallow water is to use divers. Provided visibility is
adequate, divers may measure radial distances to desired locations by
holding a tape at the outfall and traversing the appropriate distance over
the bottom in the proper direction.
Visual ranges have sometimes been used to establish a station position.
This method requires that a minimum of two objects are in alignment,
enabling the vessel to be placed on a common axis extending to the vessel's
position. Simultaneous siting on a second set of at least two objects
places the vessel at the intersection of the two common axes. The accuracy
of each visual range is highly dependent on the quality of the visual range
(e.g., alignment), the distance from the alignment objects to the vessel,
and the angle between each range. Also, the number of visual ranges used
affects the magnitude of the positional error. Although this technique is
frequently used for positioning single sampling stations in bays, harbors,
and other areas in which two or more conveniently alignable targets can be
selected, the method is not considered acceptable for coastal monitoring at
ZID-boundary stations. Also, it is not likely that a sufficient number of
alignment target-pairs will be present for all desired locations. In
addition, the unpredictability of repeatable position error detracts from
the value of this method.
D-12
-------
Permanent installation of a marker buoy at the outfall terminus or
midpoint of the diffuser allows easy return to this point on subsequent
sampling trips. Using the previously discussed range-finder technique or a
line of desired length enables positioning at desired distances from the
marker buoy. However, it is not uncommon to lose such a buoy due to
vandalism, impact, or severe weather conditions. Therefore, it is necessary
that the sampling party be prepared to relocate the outfall (e.g., by diver,
sonar, or pinger mounted on the outfall itself), if location of stations is
dependent on knowledge of the outfall location.
Because the techniques described here are inexpensive to implement (as
are use of the sextant resection or theodolite intersection methods), they
are attractive to small coastal municipalities. However, use of more
sophisticated and less labor-dependent techniques may be achievable at
moderate costs by renting or leasing, rather than buying such equipment.
USE OF LORAN-C
In their evaluation of positioning methods, Tetra Tech (1987) concluded
that Loran-C did not provide the absolute and repeatable accuracies needed
for the 301(h) program. However, because Loran-C is in such wide use and is
relatively inexpensive, use of Loran-C in a special operating mode was re-
examined in Tetra Tech (1988). The special operating mode is called
differential Loran-C, which requires an additional Loran-C receiver onshore
at a known geographic location. At this location, the Loran-C signals are
received, and a correction is generated and transmitted to the survey
vessel, allowing the correction to be applied to signals received by the
ship's Loran-C unit.
Differential Loran-C was found to significantly improve the positional
accuracies achievable compareu to Loran-C in the normal mode. During a
simulated monitoring program near Newport Beach, California, normal Loran-C
positional errors of 40-50 m (131-164 ft) were reduced to 7-15 m (23-49 ft)
using differential Loran-C in conjunction with special vessel operating
D-13
-------
procedures, a video display, and data averaging techniques. Higher
accuracies are expected in other coastal areas where improved lattice line
crossing angles occur. Acceptability may depend on relative orientations of
the diffuser and the error ellipse axes (Figure D-3, Table D-3). For those
considering use of differential Loran-C, a procedure for determining the
error in a ZID-boundary station location is provided in Tetra Tech (1988).
SYSTEM SELECTION PROCEDURE
A procedure for selecting an appropriate navigation system is described
in detail in Tetra Tech (1987). The procedure involves definition of
positioning requirements, establishment of screening criteria (e.g., range,
accuracy, availability, and costs), review of candidate systems, and
evaluation of purchase/lease options. As indicated in Figure D-4, a
stepwise screening technique is recommended to identify an optimal system
for a given monitoring program. At each step in the screening process,
systems that cannot achieve the required criterion are removed from further
consideration.
D-14
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OUTFALL PIPE
ZID
BOUNDARY
ELLIPSE ROUGHLY
PARALLEL TO DIFFUSER
95% PROBABILITY
ELLIPSE
X.Y)
I ACROSS-ZID
ERROR VARIATION
ACROSS ZID
ERROR VARIATION
ELLIPSE ROUGHLY
PERPENDICULAR TO
DIFFUSER
X.Y Coordinates of ZID-
Boundary Sampling
Station.
EH 95% Probability of
Actual Sampling
Station Position being
in this Area.
Figure D-3. Examples of differential Loran-C error ellipse orientation
at a ZID-boundary sampling station.
D-15
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TABLE D-3. THEORETICAL ERROR ELLIPSES OF DIFFERENTIAL LORAN-C
FOR VARIOUS U.S. LOCATIONS
Location
Anchorage, AK
Puget Sound, WA
San Francisco, CA
Los Angeles, CA
San Diego, CA
Mississippi Delta, LA
Panama City, FL
Chesapeake Bay, VA
Boston, MA
Approximate
Direction
of
Major Axis
NW/SE
NW/SE
NE/SW
NE/SW
N/S
NW/SE
N/S
W/E
N/S
Length
of
Major Axis3
70
180
60
90
90
50
30
40 ~
30
Length
of
Minor Axis3
20
40
30
30
20
20
20
20
20
a Lengths are given to the nearest 10 m based on 95 percent confidence level
error ellipses. Standard deviation of time differences is 25 nsecs
(achievable with differential Loran-C).
D-16
-------
2 i
CANDIDATE I SYSrEV
Figure 0-4. Navigation system preliminary screening criteria.
D-17
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REFERENCES
Bowditch, N. 1984. American practical navigator. An epitome of navigation.
Defense Mapping Agency Hydrographic/Topographic Center, Washington, DC. pp.
1272, 1278.
Dungan, R.G. 1979. How to get the most our of LORAM-C. SG 54. Extension
marine advisory Program, Oregon State University, Corvallis, OR. 12 pp.
Folk, L. 21 March 1985. Personal Communication (phone by Dr. William P.
Muellenhoff, TetraTech). Kuker-Rankin, Inc., Settle, WA.
Tetra Tech. 1987. Evaluation of survey positioning methods for nearshore
and estuarine waters. EPA-430/9-86-003. Final report prepared for Marine
Operations Division, Office of Marine and Estuarine Protection, U.S.
Environmental Protection Agency. Tetra Tech, Inc., Bellevue, WA. 54 pp. +
appendices.
Tetra Tech. 1988. Evaluation of differential Loran-C for positioning in
nearshore marine and estuarine waters. Draft report prepared for Marine
operations Division, Office of Marine and Estuarine Protection, U.S.
Environmental Protection Agency. EPA Contract No. 68-C8-0001. Tetra Tech,
Inc., Bellevue, WA.
D-18
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APPENDIX E
URBAN AREA PRETREATMENT REQUIREMENTS
-------
CONTENTS
Page
LIST OF FIGURES iii
LIST OF TABLES iv
INTRODUCTION E-l
APPLICABLE TREATMENT PROGRAM APPROACH E-3
U.S. EPA GUIDANCE E-3
LOCAL LIMITS E-5
SECONDARY REMOVAL EQUIVALENCY APPROACH E-7
SECONDARY TREATMENT PILOT PLANT DESIGN CRITERIA E-10
SECONDARY TREATMENT PILOT PLANT STARTUP E-14
SECONDARY TREATMENT PILOT PLANT OPERATING CRITERIA E-16
TOXIC POLLUTANT MONITORING PROGRAM, TESTING PROCEDURES, AND
QUALITY ASSURANCE/QUALITY CONTROL E-24
SAMPLING FREQUENCY E-25
SAMPLE COLLECTION AND ANALYSIS E-26
QA/QC E-43
UPGRADING TO A FULL-SCALE SECONDARY TREATMENT FACILITY E-50
DEMONSTRATING COMPLIANCE USING PILOT PLANT DATA E-55
REFERENCES E-56
ATTACHMENT 1: U.S. EPA OFFICE OF WATER ENFORCEMENT AND PERMITS
PROCEDURES FOR DEVELOPING TECHNICALLY BASED LOCAL LIMITS E-59
ATTACHMENT 2: U.S. EPA GUIDANCE MANUAL ON THE DEVELOPMENT AND
IMPLEMENTATION OF LOCAL DISCHARGE LIMITATIONS UNDER THE
PRETREATMENT PROGRAM E-68
E-ii
-------
FIGURES
Number Pace
E-l Components of a conventional activated sludge system E-12
E-iii
-------
TABLES
Number . Page
E-l Effluent water quality values that shall not be exceeded
under secondary treatment E-9
E-2 Secondary treatment pilot plant design criteria E-ll
E-3 Conventional activated sludge design parameters E-13
E-4 Pliot plant monitoring schedule E-17
E-5 List of test procedures approved by U.S. EPA for inorganic
compounds in effluent E-28
E-6 List of test procedures approved by U.S. EPA for non-
pesticide organic compounds in effluent E-35
E-7 List of test procedures approved by U.S. EPA for pesticides
in effluent E-38
E-8 Recommended sample sizes, containers, preservation, and
holding times for effluent samples E-41
E-9 Reported values for activated sludge biological process
tolerance limits of organic priority pollutants E-51
E-10 Reported values for activated sludge biological process
tolerance limits of inorganic priority pollutants E-53
E-iv
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INTRODUCTION
Section 303(c) of the Water Quality Act of 1987 amended Section 301(h)
of the 1977 Clean Water Act by adding the "urban area pretreatment require-
ment." This requirement applies only to POTWs serving a population of at
least 50,000 and only to toxic pollutants introduced by industrial dis-
chargers. For each toxic pollutant introduced by an industrial discharger
in affected POTWs, the applicant must demonstrate that it meets one of the
following two conditions:
• Has an "applicable pretreatment requirement in effect"
• Achieves "secondary removal equivalency."
This new statutory requirement complements the toxics control program
requirements in the existing Section 301(h) regulations (40 CFR 125.66) and
other pretreatment requirements in 40 CFR 403.
The intent of this appendix is to help POTWs interpret and comply with
the new requirement. For site-specific reasons, concepts and procedures
recommended herein may not necessarily apply to all 301(h) applicants.
Issues that are not addressed by this appendix should be directed to U.S. EPA
Regional offices. Applicants should also check with appropriate state and
local agencies for any explicit requirements (e.g., water quality standards)
that apply to them. The procedures to demonstrate compliance with this
urban area requirement must be formulated and implemented by each POTW with
concurrence from the appropriate U.S. EPA Regional office. Compliance with
the urban area pretreatment requirement is required before a 301(h) permit
may be issued by U.S. EPA, although tentative approval may be granted on
demonstration of the applicant's good faith effort.
E-l
-------
When a review of the 301(h) application indicates that noncompliance
with pretreatment requirements is substantial and that the applicant is not
taking effective steps to assure compliance, then U.S. EPA may deny the
permit. Factors relevant to such a decision include the number of non-
complying industrial sources, the nature of their toxic pollutant contri-
bution to the POTW, and potential or actual POTW interference of pass-
through.
E-2
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APPLICABLE TREATMENT PROGRAM APPROACH
Applicable pretreatment requirements for each toxic pollutant may take
one of two forms:
• Categorical standards
• Local limits.
Categorical standards are nationally uniform, technology-based pretreatment
limitations developed for specific industrial categories under Section 307
of the Clean Water Act. All categorical industries must comply with
categorical standards, even if they discharge to a POTW without a federally
approved local pretreatment program. By contrast, local limits are
developed by the POTW to prevent interference with the treatment works or
pass-through of toxic pollutants, as required by 40 CFR 403.5(b).
A given industrial discharger may be subject to categorical standards
for some pollutants and local limits for other pollutants, or to both types
of limitations for the same pollutant. In the latter case, the stricter
standard applies. The urban area pretreatment requirement for all toxic
pollutants entering a POTW will probably require a combination of both forms
of pretreatment standards.
U.S. EPA GUIDANCE
The U.S. EPA Office of Water Enforcement and Permits (OWEP) and the
U.S. EPA Office of Water Regulations and Standards (OWRS) have issued the
following guidance manuals to assist POTWs in implementing pretreatment
regulations and developing technically based local limits:
E-3
-------
• Guidance Manual for POTW Pretreatment Program Development
(U.S. EPA 1983a)
• Procedures Manual for Reviewing a POTH Pretreatment Program
Submission (U.S. EPA 1983b)
• NPDES Compliance Inspection Manual (U.S. EPA 1984)
• Guidance Manual for Implementing Total Toxic Organics (TTO)
Pretreatment Standards (U.S. EPA 1985a)
• Guidance Manual for the Use of Production-Based Pretreatment
Standards and the Combined Uastestream Formula (U.S. EPA
19855)
• Pretreatment Compliance Monitoring and Enforcement Guidance
(U.S. EPA 1986a)
• Guidance Manual for Preventing Interference at POTUs (U.S. EPA
1987a)
• Guidance for Reporting and Evaluating POTH Noncompliance with
Pretreatment Implementation Requirements (U.S. EPA 1987b)
• Guidance Manual on the Development and Implementation of
Local Discharge Limitations Under the Pretreatment Program
(U.S. EPA 1987c) (enclosed as Attachment 2 to this appendix).
The implementation and enforcement guidelines in these manuals require the
POTW to undertake the following:
• In the POTW industrial waste survey (which must be updated on
a regular basis), identify and locate all industries that
discharge pollutants into the POTW
E-4
-------
• Demonstrate that the. sampling procedures and analysis program
undertaken were adequate to characterize industrial and
nonindustrial pollutant loading to the POTW, and pollutant
concentrations in the POTW influent, effluent, and sludge
• Compare measured pollutant concentrations to applicable sludge
criteria or guidelines, water quality criteria or standards,
and POTW process inhibition thresholds
• Demonstrate that the existing pretreatment program is
adequate to control industrial user discharges, and that it
contains specific numerical limits for industrial pollutants
• Demonstrate that local limits are technically based, adequate
to protect the POTW, and allow compliance with its NPDES
permit
• Demonstrate that steps have been taken to identify the causes
of past POTW operating problems (e.g., industrial discharges,
equipment failures, plant upsets, NPDES permit violations,
sludge contamination) and correct them
• Demonstrate that POTW inspection and compliance monitoring
procedures exist and are being implemented
• Demonstrate that the needed resources (e.g., funds, staff,
equipment) are available to carry out program requirements.
LOCAL LIMITS
The technical approach used by a POTW to develop local limits is
primarily a local decision, provided that the local limits are enforceable
and scientifically based. Most POTWs use the headworks loading method in
the U.S. EPA (1987c) local limits guidance manual. OWEP-recommended
procedures for developing local limits appear as Attachment 1 to this
E-5
-------
appendix. Best professional judgment can be used to establish pretreatment
requirements when data or criteria are insufficient to perform a pollutant
loading analysis for a specific pollutant of concern. The applicant may
implement the local limits via uniform maximum allowable concentrations or
discharger-specific maximum allowable mass emissions.
Local limits should be reviewed and revised periodically in response to
changes in federal or state regulations, environmental protection criteria,
plant design and operational criteria, or the nature of industrial contri-
butions to POTW influent. For example, the following specific changes
could affect criteria used to derive local limits:
• Changes in NPDES permit limits to include additional or more
restrictive toxic pollutant limits
• Changes in water quality limits including toxicity require-
ments
• Changes in sludge disposal standards or POTW disposal methods
• Availability of additional site-specific data pertaining to
pollutant removal efficiencies and/or process inhibition.
OWEP is presently developing guidance to determine the technical
adequacy of ""ocal limits and to ensure their enforcement. This guidance
will also clarify the use of best professional judgment for establishing
local discharge limits or technology-based limits when the data are
insufficient.
E-6
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SECONDARY REMOVAL EQUIVALENCY APPROACH
One approach that 301 (h) applicants may use to satisfy the new urban
area pretreatment requirement is to demonstrate secondary removal equiva-
lency. As noted in 40 CFR 125.65(d):
An applicant shall demonstrate that it achieves secondary removal
equivalency through the use of a secondary treatment pilot plant
at the applicant's facility which provides an empirical determina-
tion of the amount of a toxic pollutant removed by the application
of secondary treatment to the applicant's discharge, where the
applicant's influent has not been pretreated. Alternatively, an
applicant may make this determination using influent that has been
pretreated, notwithstanding section 125.58(w).
In effect, the applicant's existing treatment processes and industrial
pretreatment program must remove at least as much of a toxic pollutant as
would be removed if the applicant applied secondary treatment and did not
have an industrial pretreatment requirement for that pollutant. This
approach can be represented as follows:
POTW existing + industrial = POTW existing + no industrial
treatment pretreatment treatment pretreatment
upgraded to
secondary treatment
U.S. EPA recognizes, however, that it would be simpler for applicants to
perform this demonstration by using a secondary treatment pilot plant on the
actual pretreated influent. This approach is shown below:
POTW existing + industrial = POTW existing + industrial
treatment pretreatment treatment pretreatment
upgraded to
secondary treatment
E-7
-------
Although U.S. EPA will consider them, demonstrations to account for the
effects of industrial pretreatment will probably be difficult. The
secondary treatment pilot plant approach is conservative (i.e., protective)
where it uses influent that has received industrial pretreatment, because the
calculated required removals will be greater than those resulting from a
demonstration using influent that has not been pretreated.
Secondary treatment at POTWs typically involves biological processes
that remove organic matter through biochemical oxidation, usually variations
of the activated sludge process. Other physical-chemical secondary treatment
processes (e.g., coagulation, filtration, carbon adsorption) may also be
used, particularly for nonbiodegradable wastewaters. The specific secondary
treatment process used by a POTW is dependent on numerous factors such as
wastewater quantity, waste biodegradability, and available space at the POTW
site. Each POTW must determine the best strategy and the most applicable
treatment process for complying with the secondary removal equivalency
requirements.
The level of effluent quality attainable through the application of
secondary treatment is defined in 40 CFR 133 (Table E-l). Treatment
processes that are considered equivalent to secondary treatment (e.g.,
trickling filter, waste stabilization pond) are discussed in 40 CFR
133.105. Minimum levels of effluent quality attainable from these equivalent
treatment processes differ from those shown in Table E-l.
Because secondary treatment levels were defined only for BOD, suspended
solids, and pH, POTWs were usually not required to institute technology
specifically to control toxic pollutants. Under the 1977 Clean Water Act,
toxic pollutants in the POTW effluents were controlled predominantly through
pretreatment programs, categorical standards, and local POTW limits required
by the issuance of NPDES permits.
E-8
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TABLE E-l. EFFLUENT WATER QUALITY VALUES THAT SHALL NOT
BE EXCEEDED UNDER SECONDARY TREATMENT
Variable3
BOD5
CBOD5b
SS
PH
30-Day
Average
30 mg/L
25 rag/L
30 mg/L
6.0
7 -Day 30-Day Average
Average (Percent Removal)
45 mg/L
40 mg/L
45 mg/L
to 9.0
>85
>85
>85
a BODs = 5-day measure of biochemical oxygen demand; CBOD5 = 5-day measure
of carbonaceous biochemical oxygen demand; SS = suspended solids.
b At the option of the NPDES-permitting authority, CBODs may be substituted
for 8005.
E-9
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SECONDARY TREATMENT PILOT PLANT DESIGN CRITERIA
A secondary treatment pilot plant should be designed for an average
flow of approximately 150 GPD. The flow rate should remain constant over a
24-h period. The pilot plant should .require minimum operation and main-
tenance time, and must be able to operate unattended for 16-24 h. The
organic loading will vary with the diurnal and seasonal fluctuations in the
BODs concentration in the existing POTVI effluent. Design criteria for the
secondary treatment pilot plant are shown in Table E-2.
A conventional activated sludge system (Figure E-l) for a POTW includes
the following related components:
• Single or multiple reactor basins (i.e., aeration tanks)
where microorganisms consume the organic wastes. These
basins are designed to allow for complete mixing of its
contents, which are defined as mixed liquor suspended solids
(MLSS). Each basin must provide typical hydraulic retention
times of 2-24 h.
• Pressurized or atmospheric oxygen-containing gases that are
dispersed into the reactor basin.
• Settling basin (i.e., final clarifier) to separate the MLSS
from the treated wastewater.
• Equipment to collect the solids in the settling basin, and
to recycle the active biological solids (i.e., activated
sludge) to the reactor basin.
• Equipment to remove excess active biological solids from the
system.
Typical design variables for the conventional activated sludge process are
shown in Table E-3. Additional information on activated sludge systems is
E-10
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TABLE E-2. SECONDARY TREATMENT PILOT PLANT DESIGN CRITERIA
Reactor Basin (Aeration Tank)
Volume
Detention time
Organic loading
Air requirement
50 gal (189 L)
8 h
25-60 Ib BOD/1,000 ft3/day (0.4-1.0 kg/m3/day)
0.20-0.44 ftVnrin (0.33-0.75 n^/h)
Settling Basin (Final Clarifier)
Volume
Surface Area
Overflow Area
Solids Loading
Weir Length
Detention Time
20 gal (76 L)
0.375 ft2 (0.035 m2)
400 gal/ft2/day (16.3 mW/day)
14 Ib/ft2/day (68.4 kg/m2/day)
0.5 ft (0.152 m)
3 h
Influent Feed Pump
Capacity
Type
0-290 gal/day (0-12.7 L/sec)
Peristaltic
Return Activated Sludge Pump
Capacity 0-130 gal/day (0-5.7 L/sec)
E-ll
-------
MR.UENT
EFFLUENT
WASTE
SLUDGE (WAS)
Figure E-1. Components of a conventional activated sludge system.
-------
TABLE E-3. CONVENTIONAL ACTIVATED SLUDGE DESIGN PARAMETERS
Food to microorganism ratio
Mean cell residence time
Aeration detention time
Oxygen requirements
Return activated sludge
flow rate
0.15-0.4 Ib BOD5/lb MLSS/day
5-15 days
4-8 h
0.8-1.1 Ib (kg) 02/lb (kg)
6005 removed
30-100 percent influent flow
Mixed liquor suspended solids (MLSS) 1,500-4,000 mg/L
Organic loading at
3,000 mg/L MLSS
Respiration (oxygen uptake) rate
at 3,000 mg/L MLSS
Sludge volume index
Waste activated sludge
20-60 Ib BOD/1,000 ft3
(0.3-1.0 kg BOD/m3)
15-45 mg oxygen/L/h
90-150
0.4-0.6 Ib (kg)/lb (kg)
BOD removed
E-13
-------
provided by the Water Pollution Control Federation [(WPCF) 1976, 1987] and
WPCF/American Society for Civil Engineers (1977).
SECONDARY TREATMENT PILOT PLANT STARTUP
In the activated sludge process, microorganisms metabolize nearly all
soluble organic matter in the influent. The microorganisms (i.e., active
biological solids) must be removed from the settling basin to produce an
acceptable effluent, and the proper operation of the settling basin is
critical. The following process control parameters should be monitored to
ensure proper operation of the activated sludge system:
• MLSS
• Mixed liquor volatile suspended solids (MLVSS)
• Dissolved oxygen
• Sludge volume index (SVI)
• Sludge density index (SDI)
• Organic loading
• Return activated sludge (RAS) flow rate
• Waste activated sludge (WAS) flow rate
• Mean cell residence time (MCRT)/solids retention time (SRT)
• Food/microorganism ratio (F/M)
• Temperature
E-14
-------
• Hydrogen ion concentration (pH)
• Respiration rate (RR).
In addition to these process control parameters, microscopic examination of
the MLSS should be performed.
An initial F/M ratio of 0.2 should be achieved. Field operators should
adjust the F/M ratio by changing the MLSS concentration in the reactor
basin if the required 30-day average effluent quality (i.e., 30 mg/L BOD,
30 mg/L suspended solids) cannot be achieved. If temperature varies
substantially between summer and winter, the F/M ratio will probably need to
be lowered during winter to achieve the required effluent quality.
The pilot plant should be seeded with MLSS from a local domestic
wastewater treatment facility. Acclimation of the pilot plant will require
about 4-6 wk. If there is no local source of MLSS, the pilot plant may be
started using the POTW's effluent. An additional 4-6 wk may be needed to
ensure that the MLSS meets the desired design concentration.
The MLSS should be fed with domestic wastewater for the first 2-3 days.
The volumetric proportion of the effluent should then be adjusted to 10
percent of the total feed for 4-5 days. After the initial week of operation,
the volumetric proportion of the regular POTW effluent in the pilot plant
feed can be increased approximately 5 percent per day until the system is
receiving 100 percent POTW effluent.
Sampling for 8005 and suspended solids should be conducted daily during
and after the acclimation period. Sampling for toxic pollutants should not
be started until 2 wk after the pilot plant is receiving 100 percent POTW
effluent.
E-15
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SECONDARY TREATMENT PILOT PLANT OPERATING CRITERIA
The process control parameters identified in the preceding section
should be monitored to provide information for process control and to
determine treatment efficiency. A monitoring schedule is shown in Table E-4.
The frequency of sample collection and analysis may vary for each POTW,
however, depending on the size of the POTW, available laboratory facilities,
available staff, and technical skills of personnel. Additional sampling and
analysis may be required for abnormal conditions or during periods of process
upsets. Implementation of the monitoring program, data interpretation, and
pilot plant operation and maintenance is estimated to require about 5 labor
hours per day. Each process control parameter is discussed below.
Mixed Liquor Suspended Solids
Samples of MLSS should be collected from the effluent end of the
reactor basin twice daily and analyzed for suspended solids. This analysis
will measure the total amount of solids in the aeration system. The
concentration of the MLSS, which depends on the influent BODs concentration,
should be adjusted based on the daily average.
Mixed Liouor Volatile Suspended Solids (MLVSS)
Each MLSS sample should be analyzed for MLVSS. This analysis indirectly
measures the living biological percentage of the MLSS. The concentration of
MLVSS is normally 70 to 80 percent of the concentration of the NLSS.
Dissolved Oxygen
The concentration of dissolved oxygen in the reactor basins should be
measured twice daily to ensure that a concentration of 1-3 mg/L is main-
tained. Samples should be collected about 2 ft below the surface of the
reactor basin, near the effluent weir. .The plant operator should adjust the
air supply to provide more air if the dissolved oxygen concentration is less
than 1 mg/L and less air if it is greater than 3 mg/L.
E-16
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TABLE E-4. PILOT PLANT MONITORING SCHEDULE
Sampling Point
Primary Effluent
Parameters3
Temperature
pH
SS
BOD5
Overflow rate
CBOD5
Frequency
1 grab daily
1 grab daily
4 grabs weekly and
3 24-h composites weekly
3 24-h composites weekly
1 grab daily
1 24-h composite weekly
MLSS
WAS/RAS
Secondary Clarifier
Final Effluent
Temperature
pH
Dissolved oxygen
Respiration rate
Sludge volume index
SS
VSS
Microscopic examination
SS
Sludge blanket depth
Temperature
PH
Settleable solids
SS
BODc
CBOD5
1 grab daily
1 grab daily
2 grabs daily
2 grabs daily
2 grabs daily
1 grab daily
1 grab daily
1 grab daily
1 grab daily
2 grabs daily
1 grab daily
1 grab daily
1 grab daily
4 grabs weekly and
3 24-h composites weekly
3 24-h composites weekly
1 24-h composite weekly
a SS = Suspended solids; 8005
5-day carbonaceous biochemical
solids.
- 5-day biochemical oxygen demand; CBODc =
oxygen demand; VSS = volatile suspended
E-17
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Sludge Volume Index (SVH
The rate at which the MLSS settles in the settling basin depends on the
sludge characteristics. These characteristics are described by a simple
settling test: 1,000 mL of the MLSS effluent is collected and allowed to
settle for 30 min in a Mai lory settleometer. At the end of 30 rain, the
volume of the settled sludge is measured. The SVI is calculated as follows:
volume of settled sludge (mi] x l.QOO
' MLSS (mg/L)
The lower the SVI, the more dense the sludge. An SVI of 150 or less is
usually considered good.
Sludoe Density Index (SDI)
The SDI test is also used to indicate the settling characteristics of
the sludge, and it is arithmetically related to the SVI:
SDI
bD1 SVI
SDI of a "good settling sludge" is about 1.0. A value of less than 1.0
indicates light sludge that settles slowly. An index greater than 1.5
indicates dense sludge that settles rapidly.
Organic Loading
From routine laboratory BODs analysis, the plant operator can determine
organic loading in the reactor basin.
Organic loading = (Ib BOD/1,000 ft3/day)
DHTUI c«i,,an* onn /«,«/i\ „ PQTW Effluent Flow (HGD^ x 0.0624
POTW Effluent BOD (mg/L) x Reactor Basin Volume (MS)
E-18
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Return Activated Sludge (RAS) Flow Rate
To properly operate the activated sludge process, an MLSS that settles
adequately must be achieved and maintained. The MLSS are settled in the
settling basin and then returned to the reactor basin as RAS. The RAS
allows the microorganisms to remain in the treatment system longer than the
flowing wastewater. Changes in the activated sludge quality and settling
characteristics will require different RAS flow rates.
Two basic approaches can be used to control the RAS flow rate. One
approach establishes a constant RAS flow rate, independent of the influent
flow. This approach is simple (i.e., maximum solids loading in the
settling basin occurs at the start of the peak flow periods) and less
operator attention is needed. A disadvantage of this approach is that the
F/M ratio is constantly changing. However, because of short-term variation
in the MLSS due to hydraulic loading, the range of fluctuation in the F/M
ratio is generally small enough to ensure that no significant problems
arise.
A second approach establishes the RAS flow rate as a constant percentage
of the influent flow. This approach reduces variations in the MLSS
concentration and the F/M ratio, and the MLSS remain in the settling basin
for shorter time periods (which may reduce the possibility of denitrification
in the basin). The most significant disadvantage of this approach is that
the settling basin is subjected to maximum solids loading when the basin
contains the maximum amount of sludge, which produces excessive solids in the
effluent.
Two methods are commonly used to determine the RAS flow rate. The
settleability method uses the settled sludge volume from the SVI test to
calculate the RAS flow rate:
E-19
-------
RAS Flow Rate (MGD) =
w i «* c ++1 A ci A ' i ,\ TPQTW Effluent Flow (MGD)1
Volume of Settled Sludge (ml) x •LJ-M i 000 ml —
The second and more direct method is to monitor the depth of the sludge
blanket in the settling basin. The depth of the sludge blanket should be
less than one-fourth of the water depth of the settling basin sidewall.
The operator must check the sludge blanket depth twice daily, adjusting the
RAS flow to control the blanket depth. If the depth of the sludge blanket is
increasing, increasing the RAS flow is only a short-term solution.
Increases in sludge blanket depth may result from too much activated sludge
in the treatment system, a poorly settling sludge, or both. If the sludge
is settling poorly, increasing the RAS flow may cause even more problems
by further increasing the flow through the settling basin. Long-term
corrections noted below must be made to improve the settling characteristics
of the sludge or remove the excess solids from the treatment system:
• If the sludge is settling poorly because of bulking, the
environmental conditions for the microorganisms must be
improved
• If there is too much activated sludge in the treatment system,
the excess sludge must be wasted.
The best time to measure RAS flow is during the period of maximum daily
flow, because the clarifier is operating under the highest solids loading
rate. Adjustments in the RAS flow rate should be needed only occasionally
if the activated sludge process is operating properly.
Waste Activated Sludge (WAS) Flow Rate
The increase of activated sludge is a cumulative process that eventually
produces surplus WAS. This surplus has to be permanently removed from the
treatment process and collected for ultimate disposal. The WAS flow rate
should be determined and adjusted daily to maintain the desired mean cell
E-20
-------
residence time (MCRT), based on the MLSS in the entire secondary system, and
RAS suspended solids concentration:
[Aeration Tank Volume (MG) +
WAS Flow Rate (MGD) = MLSS (mg/L) x [dlsirlr ^^ ^^
x
[RAS Suspended Solids'(mg/L)]
Mean Cell Residence Time (MCRT)/Solids Retention Time (SRT)
The MCRT, which is also called the SRT, is a measure of the age of
sludge. Under normal conditions, the MCRT is 5-15 days. MCRT is defined as:
Suspended solids in total secondary system (1b) _
Solids wasted (Ib/day) + effluent solids (Ib/day)
TMLSS (mo/DI x [Aeration Tank Volume(MG) + Secondary Clarifier Volume(MG)1
[WAS Suspended solids (mg/L) x WAS Flow (MGD)] +
[Effluent Suspended solids (mg/L) x Effluent Flow (MGD)]
MCRT is the best process control technique available to the plant
operator. By using the MCRT, the operator can control the quantity of food
available to the microorganisms and calculate the amount of activated
sludge that should be wasted.
Food/Microorganism Ratio (F/M)
The F/M ratio is the ratio of BOD in the POTW effluent to the MLVSS.
An F/M ratio of 0.15 to 0.4 is desirable. F/M is defined as:
POTW Effluent BOD fmo/L)
MLVSS (mg/L)
To control the F/M ratio, the operator must adjust the MLSS by wasting more
or less sludge.
E-21
-------
Temperature
In process control, accurate temperature measurements are required to
predict and evaluate process performance, thereby enhancing microbial
growth. Typically, the rate of microbial growth doubles for every 10° C
increase in temperature within the specific temperature range of the
microbe.
Hvdrooen Ion Concentration (oH)
The activity and health of microorganisms is affected by pH. Sudden
changes or abnormal pH values may indicate an adverse industrial discharge.
A pH drop will also result when nitrification is occurring in a biological
process; alkalinity is destroyed and carbon dioxide Is produced during the
nitrification process.
Respiration Rate (RR)
The efficiency of the activated sludge process depends primarily on
the activity of bacteria that use organic compounds in sewage for energy
and reproduction. When in contact with an adequate food supply, viable
bacteria will have a respiration rate (i.e., oxygen uptake rate) of 5-15 mg
oxygen/h/g MLSS. Respiration rate data provide immediate information
concerning viability, nitrification, organic loading, nutrient levels, and
toxicity in the activated sludge.
f
The respiration rate, or oxygen uptake rate, is monitored with a
dissolved oxygen meter over a time interval (t) (e.g., 6-10 min). The
respiration rate is a measure of the decrease in dissolved oxygen concen-
tration:
RR (mg oxygen/h/g MLSS) = TOO change over t (ma/Pi x [60.0001
[MLSS (rngyt)] x [t (min)]
E-22
-------
Microscopic Examination
Microscopic examination of the MLSS can be used to evaluate the
effectiveness of the activated sludge process. The most important micro-
organisms are the protozoa, heterotrophic bacteria, and autotrophic bacteria
responsible for purifying the wastewater. Both protozoa (e.g., ciliates)
and rotifers are indicators of treatment performance, and large numbers of
these organisms in the MLSS indicate good quality sludge. Large numbers of
filamentous organisms and certain ciliates Indicate poor sludge quality, a
condition commonly associated with a sludge that settles poorly (i.e. the
sludge floe is usually light and fluffy because it has a low density). Many
other organisms in the sludge (e.g., nematodes, waterborne insect larvae)
may be found in the sludge. However, these organisms are not significant to
the activated sludge process.
E-23
-------
TOXIC POLLUTANT MONITORING PROGRAM, TESTING PROCEDURES,
AND QUALITY ASSURANCE/QUALITY CONTROL (QA/QC)
A sampling strategy must be developed to estimate the difference
between toxic pollutant concentrations in the existing discharge and those
in the secondary treatment pilot plant discharge. Samples must be collected
using proper techniques and analyzed using appropriate analytical methods.
Both field and laboratory methods must be performed under defined QA/QC
procedures.
Applicants are referred to the following documents for guidance on
specific topics relevant to the design and execution of 301(h) monitoring
programs:
• Sampling/Monitoring Program
NPDES Compliance Sampling Manual (U.S. EPA 1979a)
Design of 301(h) Monitoring Programs for Municipal
Uostewater Discharges to Marine Haters (U.S. EPA 1982a)
Handbook for Sampling and Sample Preservation of Water
and Uastewater (U.S. EPA 1982c)
• Chemical Analytical Methods
Methods for Chemical Analysis of Uater and Hastes (U.S.
EPA 1979b, revised 1983)
Guidelines Establishing Test Procedures for the Analysis
of Pollutants [40 CFR Part 136 (1984)]
E-24
-------
Standard Methods for the Examination of Hater and
Hastewater (16th ed.) (American Public Health Association
1985)
Analytical Methods for EPA Priority Pollutants and
301(h) Pesticides in Estuarine and Marine Sediments
(Tetra Tech 1986a)
Analytical Methods for EPA Priority Pollutants and
301(h) Pesticides in Tissues from Estuarine and Marine
Organisms (Tetra Tech 1986b)
• Quality Assurance/Quality Control (QA/QC)
Handbook for Analytical Quality Control in Mater and
Wastewater Laboratories (U.S. EPA 1979c)
Quality Assurance/Quality Control (QA/QC) for 301(h)
Monitoring Programs: Guidance on Field and Laboratory
Methods (Tetra Tech 1987).
Information from these documents is summarized below.
SAMPLING FREQUENCY
The frequency of sampling is dependent on the characteristics of the
discharge (e.g., influent and effluent toxic pollutant variability, flow,
size and location of the discharge). For example, large applicants with
substantial quantities of toxic pollutants should conduct more frequent
sampling than small dischargers with fewer toxic pollutants. Also, if
existing toxic pollutant data are minimal, and estimates of periods of
maximum pollutant loadings and peak concentrations are not known, then more
frequent monitoring is needed.
E-25
-------
The concentrations of toxic pollutants in the discharge may vary in
response to periodic peak inflows. If a fixed periodic trend is observed
(e.g., a sine curve) the sampling plan could be designed to collect samples
during the peak period.
If a fixed sampling interval is chosen that is equal to or a multiple
of the period, every sample would be taken at the sane inflow condition and
the estimate of the mean difference in toxic pollutant concentrations
between samples would not take into effect all possible inflows. The most
favorable sampling situation occurs when the fixed sampling interval is an
odd multiple of the half-period (i.e., successive deviations above and below
the mean inflow would mathematically cancel one another, and the mean
difference in concentration between samples would take into effect the mean
inflow). However, toxic pollutant effluent data from the applicant may not
be sufficient to identify the odd multiple of the half-period. In this
case, a fixed sampling interval would not be recommended.
Assuming that the toxic pollutant limits for the POTW will be based on
the pollutant concentrations measured in the secondary treatment effluents,
a flexible sampling scheme for secondary treatment pilot plant effluents may
involve sample collection for 1 day/wk (over 24 h) on different days of the
week over a 1-yr period of pilot plant operation. This flexible sampling
frequency would generate a data set that represents an acclimated biological
treatment system. It would also address the day/night, weekday/weekend, and
seasonal variations in domestic, industrial/commercial, and wet- and dry-
weather discharges.
SAMPLE COLLECTION AND ANALYSIS
Representative samples must be collected to ensure that data are
reliable. Care must be taken to select appropriate sampling devices and
procedures. Depending upon the toxic pollutant to be analyzed, three types
of samples may be collected:
E-26
-------
• Grab sample - a discrete sample volume is collected. (This
type of sample will not always provide an accurate measure
of wastewater characteristics, particularly when the flow or
pollutants are heterogeneous or vary with time.)
• Simple composite sample - equal sample volumes are collected
sequentially overtime and combined in a single reservoir.
(This type of sample does not measure the mass of pollutants
discharged, because pollutant loading is a flow-related
value.)
• Flow-proportioned composite sample - incremental samples are
collected over time and sample volumes are proportional to
flow. Incremental samples are combined in a single reservoir.
(This type of sample provides the most accurate measurement
of wastewater quality and pollutant loading.)
The methods to be used for the analysis of toxic pollutants are
summarized in Tables E-5, E-6, and E-7. Grab samples for volatile organic
compounds, total recoverable phenolic compounds, and cyanide should be
collected manually at least four times during the discharging period of the
POTW during a 24-h period (e.g., at least every 6 h within a 24-h period,
assuming continuous discharge). Samples for all other variables should be
collected using an automatic sampler. The automatic sampler should collect
a selected number of sample aliquots (minimum of 100 ml each) during the
discharging period of the POTW. Recommended sample sizes, containers,
preservation techniques, and holding times are shown In Table E-8. Sample
analyses will generally be completed by the analytical laboratory within
4-6 wk; data analyses will generally require an additional week. Interpre-
tation of all data collected at the pilot plant during 1 yr will require
about 2 wk.
E-27
-------
TABLE E-5. LIST OF TEST PROCEDURES APPROVED BY U.S. EPA
FOR INORGANIC COMPOUNDS IN EFFLUENT
Note: This table is an exact reproduction of Table IB in 40 CFR 136.3,
Parameter, units, and method
1 Acidity, u CjCOj mg/L Electrometric
end potm or pnenoipmhaiem tnd point.
2. Alkalinity, a* CaCOi mg/L
Eloctrometnc & coiorirnetnc titration
to pH 4.5. manual, or.
Automated
3. Aluminum— Total ' mg/L: OigmMn '
followed by:
AA diract aspvation
AA furnace
inductively coupled ptainia of
Cotonmatric (Encnrome cyanma fl)
4. Ammonia (as N), mg/L: Manual di-
lation (at pH 9.5) » loiiowad by.
Nessienxaoon
.
Automatad aiecuode
5. Antimony— Total ». mg/L Digestion »
touowadby:
AA drect aspvation
AA fumaca or
inductual> coupiad plasma
6 Arsemc— Total '. mg/L Oigastion »
loiiowad by
AA gasaous hydnda
AA fumaca
inductively coupiad plasma, or
Cotonmetnc (SDDC)
7 Banum— Total J. mg/L Digestion > tot-
lowad br
AA direct aspiration
AA fumaca. or
inductivaty coupiad plasma
8. Baryibum— Total '. mg/L Oigastion *
followed by:
AA d»act aspraton
AA furnace
inductively coupled plasma, or
Colonmetnc (ahxxnon)
9 Biochemcal oxygen demand (BOO.).
mg/L
Omsofved Oxygen Depletion
10. Boron— Total. mg/L
or induciNtly Coupisd ptfttnta
12. Cadmium— Total >. mg/L Digestion »
followed by:
AA droct aspiration
AA lumaet
induchvety coupled plasma
vottametry I0 or
Colonmetnc (Ditnizone)
13 Caiouin— Total ]. mg/L Oigestwn 3
loiiowed by
AA direct aspiration
Reference (method No or pag«>
EPA 1979
305.1
310 1
310.2
202.1
202.2
3502 ..
350.2
350.2
3503
350.1
204.1
2042.
206.5
206.3
206.2
206.4
2061
206.2
210.1
210.2
4051 .
2123...
320.1
213.1
21 3.2
215.1
Standard
metnodt
istn Ea.
402(4 •)
4Q3
303C
304
3068..
41 7A
41 7B
41 7O
417 E OfF...
41 7G
303A
304
303E
304
307B
303C
304
303C
304
3098
507 ....
404A
303 A or 8,
304
31 OB
! 303A
ASTM
106742(E)
01067-62(6)
01428-79IA)
01426.79(0) ..
01426-79(0)
02972-64(8)
02972-64(AK..-
036S4-64(A)
01246-82IC)....
0355744 (A
or 8).
USGS'
1-1030-44
I-2C30-44
I-3051-A4 . .
I-3S20-44
1-4523-44
I-3062-44
I-3060-44
I- 3094^*4
I-309S-94
1 -1578-76 7
1-311 2-»4
l-1125-«4
1-3135-44 or
1-3136-44
i
03557-64(C) -
1
OS11-*4(B)
!
I-315J-44 ..
Otner
33014^
2007*
33 057 '
33 057 '
NOW 6.
200.7.«
2007*
200.7'
200.7 «
33.019'. p. 17'
200.7. •
P. S44.»
33 089 ». p. 37 '
200 7 «
i
E-28
-------
TABLE E-5. (Continued)
Parameter units, ana metfoo
nefefence imetnod No or page)
Standard
EPA 1979 metnoas *STM uSGS ' Otner
i6m '6d
inductively couoiea piasma. or
T.tnmetnc lEOTA) 2152 3nC..
'4 Carbonaceous oiocnemtcai orygen 507(5 e 6)
demana (CBOD .). mg/L " Dissolved •
Oxygen Oeoienon with iitnticawn in-
hibitor
is Chemical oxygen demand (COO).
mg/L
TitnmetPC or ! 410 i I 508A
Spectropnotometnc. manual or auto-
mated.
16. Chloode. mg/L.
Titnmetnc (silver nitrate)
or (Mercuric nitrate), or
Colonmetnc manual or
Automated (Femcyanide)
1 7 Chlorine— Total residual. mg/L.
Titnmetnc: .
Amoerometnc dvect
Starch end pomt direct
Back mratton either end
point '«. or
OPO-PAS
Spectropnotometnc. OPO
Or Electrode
18 Chromium VI dissolved. mg/L: 045
micron filtration followed by:
AA cheJabon-extraction. or
Colonmetnc (DiphenytcarOanOe)
19 Chromium— Total ]. mg/L. Diges-
tion ' followed by:
AA direct aspiration
A A cneiauon extraction ....
AA furnace
inductively coupled plasma or
Colonmetnc (Qiphenylcaroagde)
20 Cobalt— Total '. mg/L: Digestion J
followed by:
AA direct aspiration
AA "umace or
i-?jctiveiy coupled plasma
21 Cc-or platinum cobalt urets or don*-
nam wavelength, hue. luminance
Ounty:
Colonmetnc (AOMI) or . .
(Platinum cobalt), or
22 Copper— Total1 mg/L Digestion-1 fol-
lowed by:
AA direct aspiration
AA furance '
inductively coupled plasma
Colonmetnc (Neocuproine) or
(Bictncnoninate)
23. Cyaraoe— Total. mg.L: Manual distil-
lation with MgCk followed by
Titnmetnc or
410.2. or
410.3 !
4104 '
325.3
3251. or
325.2
330 1
3303
330.2
3304
330.5
407A
407B
4070
408C
408A
4088
4080
408E
21B.4 i 303B
218 1
2183
218.2..
219.1
2192
110 1
110.2
110.3
220.1
220.2
303A
303B
304
3128
303 A or B...
30*
2040
204A
2048
303 A or 8...
304
3138
O5n-84
Note 15
307B.'«
33.089'
200.7'
P 37«
200.7 •
Note 17
33.089'. p 37 •
200.7."
Note 16.
p. 22.'
E-29
-------
TABLE E-5. (Continued)
Parameter units, and memoa
: Sundaro
EPA 1979 ; metnads
I • 16th Ed'
Seferenct
(mttnod Ho. or page)
: ASTM I USGS <
Other
24 Cyandie amendable to cnionnaMn
mg.'L Manual distillation with MgO..
followed by ntnmetnc or spectropnoto-
metnc
25 Fluonde— Total. mg/L. Manual distil-
lation' followed by
Electrode manual or
Automated.
Cotonmetnc (SPAONS)
Or Automated comptexone
26 Gold— Total9. mg/L Digestion'
-------
TABLE E-5. (Continued)
Parameter, unrta. and method
Refer
j Standard !
EPA 1979 ' metnoda !
: tern Ed. !
•nca (ntattiod No. or pagv)
i !
ASTM | USQS1 Othar
35. Mercury— Total ». mg/L
CoM vapor manual or .... ...
Automated
36. Molybdenum— Total ». mg/L Oigee-
ton* followed by:
AA diraet aapvation
AA furnace or
37. Mien* Total'. mg/L Oigaetton'
tallowed by:
AA direct aapratton
AA furnace
^.AbMtah^Vb* /U^MtMVMMAh
36. Nitrate •*• N). mg/L Cotortmetrtc
(Bruome ..fata), or Nr&ate-nrmte N
minua Nitna N (See parameter! 39
and 40).
39. Nttata-flrtrite (aa N). mg/L Cadmium
reduction. Manual or
Automated, or ,„„.....,
40. Nttite (aa N). mg/L Spectropholo-
«*%^Me*^>
ii*WiC*
Manutf or
HIQ/LJ QnvvnMftc (wttoctton)*
^2 Organic ruTinn Tntil (TOC), mg/L
ComDuftttoo or oBOBDon.
43. OrgMe ratroQ^n <•• N) mg/L Tot*
Kj*dlN N (P.¥aVn.JtO 31) fTWM «IV
morw N (Pwrwttr 4.).
44. OrtfnpnoapnaM (aa P). mg/L Aaoor.
DIC acid moffodt
Automated or...
Manual angle reagent ...._.„.„.
or Manual two reagent
45. Oamium— Total «. mg/L Oigaatton'
followed by:
AA diraet *T**ittrff*. or
AA furnace . „
(A«od»K fWoinC4uori}( or
Etoemde
47. Palladium— Total '. mg/L Dlgeetten •
followed by
AA furnace , ,
48. Phenol mg/L
FoNOVMQ by!
CoiorvTwtlc (-1AAP) m.vu^. or
Autormtvd >t
49 ptmrjftorm (•tomtnttf) mg/L: QM-
SO. Pho«pfwfu»— Total, mg/U PvaUfaia
dlgMtton foNowad by
Manual or
or.
245.1
245.2.
246.1
246J.
249. 1._ _..
249.2. .
352 1
393 S
353.2,
353 1
3941
413.1 „
4151 .
368.1
30&2.
MS 3
252.1
352,2,,
MQ2
380.1
253.1
253,2
420.1 —
420 1
420.2. . _
'
36U.
365 3. or
365.3.
366.1
365.4
303F
303C
304 ...
303 A or B...
304 .... _ ...
3218
416C.._
416F
419
W3A
SOS ....
424Q
424F
303C
304
4218
421 F .
424C4III)
424F .
424G
03223-80
01866-64 (C
orO).
0992-71
O3867-«5(B)
D3867-«5(A)
01254-67...
02579.65 (A or
8).
051S-62(A)...:....
0888-61 (C)
01783-60 (A
or 8).
051S-62(A)
I-3462-84
I -34 90-84
1^499-44
I-4S49-64
I-4540HM
l_4601-64
1-1575-76'
M 576-76 T
1 4600 'S4
•
33095 *
2007 4
2007 *
33063* 4190 >•
p. 26.'
Note 24.
33.044 >, p. 4."
33.116. '
33.111.*
33.026. •
P. S27.»
P. S26.'
Note 26,
Note 26.
Note 27.
33.111.'
33.116.'
E-31
-------
TABLE E-5. (Continued)
Pwrt0t6f , unrts, and fnatnoo
51. Platinum— Total ». mg/L DigaWon'
toflowad OIT
AA direct aapirabon or
AA fumaca
52. PotnaMm— total *. mg/L Oigaation
feftowadby:
RMM jJyiinitMtig- *doa*cata) or
62. Silvar— Total '*. mg/L Pgaation •
(oltowadby:
AA diract aapranon
AA lumaca „..
63. Sodium— Total ». mg/L Ogaatton »
tonowadbr
AA diract Mpraoon
inducovaty coupiad piaama. or .
Rama photomatnc .. . .
_4_ At 4C'^> lAA»^i^^«*«k^b^ ^- -•
cm •! 2a w. wn*Mmon9 DnOQ0
65. SuHatt (M SO«). mg/L
AutomsMd cotefimtuic. (bwwm
craoranrtatt).
Turbidwnatne
66. Suffida (ai S). mg/L
Tttnmatnc (iodma) or
Cotormatnc (mattiyiana Wua)
67. Sulfita (a» SC>). mg/L Tttnmatnc
dodmaiodata)
68 Surlactants. mg/L: Cotonmatnc
(m»my»«na bloat.
69 Tamoaratura. 'C.. Tharmomatnc
EPA 1079
2551
255.2
258.1
160.3
1601
160.2....
160.5
1604
2651
2654.
267 1
267.2.
270.2.
270.3.. .
370.1
272.1
2724.
273 1
375.1 .
! 375.3
375.4
I 376.1
! 376.2
j 3771
: 425.1
i 170.1
Ra
Standard
fnainoos
letfiEd.
303A
304
303A
322B
209A
2096
209C
2096
2090
909A
304 _.
303A
304
304
303E
425C
3O3 A r* 8
304
303A
3256
I
426 A or B.
j 4270
! 427C
' 428A
5128
. 212
Faranca (inathod I
ASTM
D142B>J9(A1
038S9-44(A) . .
0659-40(8)
01 426-821 A)
: OS 16-621 A)
0516-62(8)
01339-84(C)
02330-821 A)
40. orpaga)
USGS'
1-3630-M
'
U3750-64
1-1750-64
t-3765-64
1 _ _
1-3753-64
1-3667-44
M700-64
1-2700-64
1-3790-64
1-3735-64 .
1 1-3640-64
Othar
33103'
90O 7 4
317B '•
200.7«
20074
33 089 * p 37 '
3196 '•
2007«
33.107 «
200.7.«
i 11 Afi9 1
' 33.124 .»
426C."
22BA .'«
Nota 31
E-32
-------
TABLE E-5. (Continued)
Reference (method No. or oagei
Parameter, units, and method
EPA 1979
Standard
metnods
i6in Ed.
ASTM
USGS'
Other
70 Thallium—Total3. mg/L Digestion 9
followed by:
AA drect aspvstnn 279.1 303A :
AA furnace, or 279.2 304
inductively coupled plasma , ; 200.7 •
Tin—Total 9. mg/L dotation > tot- ' ;
by: • '
AA *wct aspiration, or j 282.1 1 303* I ; 1-3850-78' :
AA tumact i 282.2 : 304 j , :
Titanium—Total 9. mg/L Digestion3 j ' | , ;
followed by:
71
72.
AA dvect sspvstion or
AA furnace
73 TurtMWy NTU" Nephelornelnc
74. Vanadium. Tout '. mg/L: Digestion »
followed by:
AA direct aspiration
AA furnace
Cotonmecnc (Game acid)
75. Zinc-Total9. mg/L Digestion1 tot-
ISM*^Btf4 t*u>
KJWPQ afi
AA direct Mpirabon . .
AA fumtc*
(Ztncon)
283 1
2832
180 1
286 1
2862
2M1
2892
303C
304
214A
303C
304
3278
303A Of B
30*
32BC
01889-81
03373-84 Manual disiMation is not required if comparability data on representative effluent samples are on company Me to show that
ths prekmnary drstillatton step ia not necessary; however, manual distillation w* be rrjursd to resolve any controversies.
•Ammoraa. Automated Electrode Method. Industrial Method Number 379-75 WE. dated February 19. 1976, Techncon
AutoAnatyzer II. Techncon Industrial Systems, Tarrytown. NY. 10591.
'The approved method is that cited in "Methods for Determination
Sediments". USGS TWRI. Book 5. Chapter A1 (1979).
• American National Standard on Photographic Proceseng Effluents. Apr. 2. 1975. Available from ANSI. 1430 Broadway.
New York. NY 10018.
• "Selected Analytical Methods Approved and Cited by the United States Environmental Protection Agency." Supplement to
the Fifteenth Edition of Standartf Xefnuui for me £wnrwaon of Wmr *W rVjsrewerer (1981).
10 The use of normal and differential pulse voltage ramps to increase sensitivity and resolution is acceptable.
1' Carbonaceous bnchemwal oxygen demand (CBOD.) must not be confused with the traditional BOO. test which measures
"total BOO." The addition of the minftcauoH inhibitor is not a procedural option, but must M included to report jhe CBOD,
parameter. A discharger whose permrt requires reporting ths traditional BOO* may not use a mvrficaoon tnhtotor in the
procedure for reporting tne results. Only when a discharger's permrt specmcalty states C8OO» « reoured. can the permittee
report data using tne nrmticaoon nr*drtor.
E-33
-------
TABLE E-5. (Continued)
1 -' QIC Chemical Oxygen Demand Method. Oceanography international Corporation. S12 West Loop. P.O. Boi 2980. College
Station. TX 77840
1:1 Chemical Oxygen Demand. Method 8000. Hach Handbook ol Water Analysis. 1979. HICK chemical Company. P.O Box
389. Lovetand. CO 80537
1' The back titration method will be used to resolve controversy.
'••Onon Research Instruction Manual. Residual Chlorine Electrode Model 97-70. 1977. Onon Research incorporated. 840
Memorial Drive. Cambridge. MA 02138.
'" The approved method « mat cited m Sunava Hmthoa* for th» EamatMn ol Wiur tna Wuifwat*. I4tn Edition.
1976.
IT National Council ol the Paper industry for Ar and Stream improvement, (inc.) Technical Bulletin 253. December 1971.
"Copper. Biconchomate Method. Method 8906. Hach Handbook of Water Analysis. 1979. Htcti Chemeil Company. P0.
Box 389. Loveland. CO 80537
10 After the manual doMlauon is completed, the autoanalyzer manrfoMs in EPA Methods 3353 (cyande) or 420.2 (phenols)
are simplified by connecting the re-sample line dvactty to the sampler. When unrig the rnantoM setup shown m Method 335.3.
the butler 6.2 should be replaced with the butler 7.6 found m Method 335.2.
10 Hydrogen ion (pH) Automated Electrode Method, industrial Method Numeer 378-7SWA. October 1976. Techmcon Auto-
Analyzer II. Techmcon Industrial Systems. Tanytown. NY 10591.
" Iron. 1.10-PhenanthroMne Method. Method 8008. 1980. Hech Chemical Company. P.O. Boi 389. Loveland. CO 80537
" Manganese. Penodate Oxidation Method. Method 8034. Hach Handbook of Wastewater Analysts. 1979. pages 2-113 «na
2-117. Hach Chemical Company. Loveland. CO 80537.
" Goerfitz. D.. Brown. E.. "Methods for Analyst* of Organ* Substance* m Water." U.S. Geotoocal Survey Techniques of
Water-Resources Inv.. book 5. eft. A3. page 4 (1972).
" Nitrogen. Nitnte. Method 8507. Hach Chemical Company, P.O. Box 389. Loveland. CO 80537.
" Just poor to dmtillation. admit the suHure-aod-preterved sample to pM 4 wrtti .1 * 9 NaOH
'• The approved method is that cited in Sttnoiro Afemootf lor ttm ejomnitiofi ol Wtttr ana Wmittmtwr, 14th Edition The
coionmetnc reaction « conducted at a OH of 10.0=0.2. The approved method* «r» gtven on pp. 576-81 of the 14th Edition:
Method 510A tor distillation. Method 5108 for the manual coionmetnc procedure, or Method 510C tor the manual
spectrophotometnc procedure.
" R. P. Addnon and R. G. Ackman. "Direct Determination ol Elemental Phosphorus by Gat-Liquid Chromatography."
Journal of Chromttognphy. vol. 47. No. 3. pp. 421-426. 1970.
" Approved methods for the analysis of rtver m industrial wutewater* it concentration* of 1 mg/L and above ire
inadequate where silver exist* as an inorganic haMe. Silver hahdes such as the bromide and crdonde are relatively insoluble in
reagents such as nrtnc aod but are readily soluble m an aqueous butter of sodium thiosurfat* tnd sodwm hydroxide to a pH ol
12 Therefore, for levels of stover above 1 mg/L 20 ml of sample should be dduted to 100 ml by adding 40 TIL each of 2 M
Na,S.-O) and 2M NaOH. Standards should be prepared in the same manner. For levels of silver MOW 1 mg/L the approved
method is satisfactory.
" The approved method is that cited in Sonavt MtmoOs (or fne Extrrwnitori of Vtmtmt if* Wmttmittr, 15m Edition
10 The approved method is that cited in SunOira Mtfflods lor ttm Sxtmnttori of W*M tna W*$ttwtttf 13th Edition.
:" Stevens. H. H.. Ficke. J. P.. and Smoot. G. P.. "Water Temperature—influentiel Factors. Field Meisurement and Data
Presentation." U.S. Geological Survey. Technique* of Water Resources investigation*. Book i. Chapter 01. 1975.
" Zinc. Zincon Method. Method 8009. Hach Handbook of Water Analysis. 1979. page* 2-231 and 2-333. Hach Chemical
Company. Loveland. CO 80537.
E-34
-------
TABLE E-6. LIST OF TEST PROCEDURES APPROVED BY U.S. EPA
FOR NON-PESTICIDE ORGANIC COMPOUNDS
Note: This table is an exact reproduction of Table 1C in 40 CFR 136.3.
1 Acenaphthene
2 ArimapMftyijuw
3 Acrolein
4 Acrytorntnle
5 Anthracene .
7 Benzidme . .
8 Benzol a ^anthracene
9 Benzo|a)pyrene
10 Benzolblfiuorantnene
1 1 Benzo(9 h Operyiene
1 2 Benzo(k)fluorantnene
13 Benzyl cnionde
14 Benzyl butyl phthaiate
IS Bis(2-chioroethoxy) methane
16 Bis(2-cftloroethyl) ether
17 BiK2-ethyihexyi) phthaiate
1 8 Bromodichlor orriethane
19 Bromotorm
20 Bromomethane
21 4-Bromopnenyiphenyi ether . . .
22 Caroon tetracnioode
23 4-Chloro-3-methylphenol
24 Chiorooenzene
25 Chioroethane
26 2-Chioroethviwinyi ether
EPA*
GC
610
610
603
603
610
602
610
610
610
610
610
606
i 611
' 611
' 606
I 601
! 601
i 601
611
601
604
601.602
i 601
i 601
lethod Number - :
GC/MS
625. 1625
625. 1625
'624. 1624
•624. 1624
625. 1625
624. 1624
'625. 1625
625. 1625
625. 1625
625. 1625
625. 1625
625. 1625
625 1625
625 1625
625. 1625
625. 1625
624. 1624
624. 1624
624. 1624
625. 1625
624. 1624
: 625. 1625
, 624. 1624
i 624. 1624
• 624. 1624
HPLC
610
610
610
605
610
610
610
610
610
OthAT
Note3. p. 1:
Note 3. p. 130:
Note 6. p
Si 02.
Note 3. p 130
Note 3. p 130.
i
i
E-35
-------
TABLE E-6. (Continued)
sarameter
27 CriiottJlorm
28 Chiorometnane
29 2-CMoronaontnaiene
30 2-CNoroontnol
31 4-Oioropntnyipntnyl ttntr
32 Orystnt
33 Dib*nzo(a.n)anthracan«
34 Oioromocnioromttnana
35 1 2-OicniorODtnztnt :
36. i .3-Oicnioroo*nztfl«
37 i 4-OicniorODtnztfl* ;
38 3.3 -OictiforoMnzidmt i
39 OicnioroOifiuorornttfiant j
40. i i-Dicnioro*tnan«
41 i 2-0«ri*oro«man« i
42 i 1 -Oichkxottnan*
43 trans* 1 2-OiCflloro*th*nt
44 2 4-Dichloropfwiol • i
45 1 2-QicfMOfOpropant
46 os-1 3-OicniOfooroDtn*
47 trftna.1 3-PichHMtiQfQoafia
49 Dictnyi pntnaiatt
49 2 4.0irn«tfiytpf»«nol
50 Dimtthyi pfwhaiat*
Si Oi-o-outyi pfitnaiatt
52 Oi-n-ociyt pfitnaiatt
53 2 4-Oinitrop'Mnel
54 2 4 Dinitrotolutrn
55 2 6"OinitfolOKj4>n*
56 Epicniorofiydnn
57 Etnyibtnrtnt.. . . .
56. Fluoranttwn* .
59 Fluortot
60 ^yae^'yofrt^Ty^
§1 Hnacnxxooutadicff*
62 H»iaefilofocyclootntaO«r>t
S3 "•*aeflK>fo#ifan*,
64. Id«no<1.2.3-Cd)pyrto«
65 isopftofon*
66 M*tnyttn* cfflono*
67 3 Mttfiyl < 0 onnropftanol
66 Naofttnaicn*
09 NitroMnnffM
70 I Nitroptnool
71 4-Nrtrnptwnl
73 N*NitfOMdHv0ropyla)fiww
74 N-NitroMdipMnytamnc
75 2 2*-Ovytm4l-%ftloropropan«)
76 PC8-1016
77 PCS- 1221
78 PCS- 1232
79 PCS- 1242
80 PC8-1248
81 PCS- 1254
82 PC8-1260 .. .
83 py«ac'"flfort>tQfQQ'to9ftIQ-&TGWtrt
88 112 2-T*tracniofo«ttian*
89 Tatfacfliofo
-------
TABLE E-6. (Continued)
EPA MetrtOO Numoer • '
Parameter — Otner
GC GC/MS
92 1.1.1-Tncnioraetnane . .
93 1.1.2-Trtcnioroemane . .
94 Tncmoroetnene
95 Tncniorotluoromethane
96 2 < 6-Tnchlorophenol
97 Vinyl chloride
601 •
601 !
601 I
601 I
604 |
601
624. 1624 L
624. 1624 L.
624. 1624 (. .
624 L
625 1625 L
624 1624 j.
Not* 3 0 '30
•
Tab* 1C NOtM
' All parameters «r* expressed in rmcrograms per liter (
'The full text o) Methods 601-613. 624. 625. 1624. and 1625. are grven at Appendix A. "Test Procedures lor Analysis oi
Organic Pollutams." of this Part 136 The standardized test procedure to oe used to determine the method detection limit
(MOD for these (Ml procedure* « given at Appendn 8. "Definition and Procedure tor me Determination of trie Metnoo
Detection umrt." of tmt Part 136.
'"Method* for Benrdme: Chlorinated Organic Compound*. PemacMoropnenoi and Petbodn m Water and wastewater"
U.S. Enwonmental Protection Agency. September. 1978.
•Metnod 624 may be extended to screen sample* for Acrotem and Aoytonrtrte. However. «nen they are known to De
preaent. tne preferred method for the*e two compounds » Metnod 603 or Method 1624
'Method 625 may be extended to include bera**ne. neiacntorocyOopenudiene. N-mtra*odwmemyamme. and N-mtrosodi-
phenyiamme. However, when they are known to be present. Method* 605. 607. and 612. or Metnod 1625. are preferred
method* tor these compounds.
• 625 Screenmo only
•"Selected Analytical Method* Approved and Cited by the United Slates Enwonmemal Protection Agency." Supplement to
the Fifteenth Edrnon of Stsnuv Utthoe* lor tn» &nmn»aon ol Wtttr tna HfiammMr (1901).
' Each analyst must make an initial, one-am*, demonstration ol me* aMity to generate acceptable precwon and accuracy
with Method* 601-613. 624. 625. 1624. and 1625 (See Appendn A of thi* Part 136) m accordance with procedures each m
section 8.2 ol each of these Method*. Additionally, each laboratory, on an orveomg bases must spike and analyze '0% (SS
for Methods 624 and 625 and 100% for methods 1624. and 1625) of aH samples to monitor and evaluate laboratory data
quality in accordance with sections 6.3 and 8.4 of these Method*. When the recovery iof any parameter falls outside me
warning limits, me analytical results for that parameter m tne un*p*ed sample are suspect and cannot be reported to
demonstrate regulatory compliance.
NOTE: These warning limits are promulgated as an "interim final actnn with a request lor comments."
E-37
-------
TABLE E-7. LIST OF TEST PROCEDURE! APPROVED
BY U.S. EPA FOR PESTICIDES1
Note: This table is an exact reproduction of Table ID in 40 CFR 136.3.
Pvanwtar nQ u
1. Alorm
2. Am*tryn . ...
5 Atrtim* ,
8. Aanphot m*thyt
7 Ba/twn
8. o-BMC
9. 0-8HC
10. 5-8MC
11 y-8HC (Lindan*)
12 C*ptan
13. CaiDvyi
14 Cmt*--* •••**•««
15 Cmoraan*
16 ChtoropropMin
17 24-O ... .
18. 44-OOO
19. 4.4'-O06
20. 4.4'-OOT
ii^imil
wvinoQ
ac
GC/MS
GC.
TLC
oc
GC
OC
TLC
GC...:
GC/MS ...
GC
GC/MS
GC
GC/MS ..
GC
GC/MS ...
GC
TUC
GC
GC
GO-MS
TUC
GC .
GC
GC-MS
GC
GC/MS ...
GC
GC/MS
EPA"
808
825
808
»825
sot
825
808
•825
808
825
808
825
808
825
808
825
808
825
Sttnfr
vd
M«fv
-------
TABLE E-7. (Continued)
'arametar "0/U
M*moo
Suno-
4Td
Mtm-
oas
iStn
Ed
ASTM
Om*r
21
22
23
Demeton-0
Dementon-S
Oiazinon
GC.
3C
Not* 3. p 25: Nota 6. p. SSt
, Not* 3. p. 25: Not* 6. p S51
: Now 3. p. 25: Nota 4. p. 30:
Nota 6. p. S51
24 Oicamba
25. Dicnlofemmon
26 Dicmoran
27 OiCOfOl...
28 Dtetdnn
29 ~ oxatf»ofi
30 Qitultoton
31 Duron
32 Endotutfan 1
33. Endosulfan 11
34 EndotuHan lutfata
35 Endrtn
36 Endnn atdenyde
37 Eihion
38. Panuron
39. Fenuron-TCA
40. Hepwcnior
41 Hepwcnior aponde .
42 isodnn
43. Linuron
44. Maiatnion
45 Metnocarb
46. Metnoxycnlor
47 Mexacarbata
48. Mrex
49. Monuron
50. Monuron-TCA
Si, Neburon
52. Paratnion methyl
53. Paratnion atnyl
54. PCNB
55. Pennane
mm Qmftfft m if ftm
58 Propaztne
59 Propnam
60 Propoiur
61 Sectnimeton
62 Siduron
63 Stmuine , ^
94 Strooan*
65 Swep
66 245-T
67 2 4 5-TP (Sdvei)
68 Taroutriylazm*
69 Toiapnene
70 Tnfluralm
ac
GC
GC
GC
GC
GC/MS
GC
GC
TLC
GC
GC/MS
GC
GC/MS
GC
GC/MS
GC.
GC/MS . .
GC
GC/MS
GC
TLC
TLC
GC
GC/MS
GC
GC/MS
GC
TLC
GC
TLC
GC...
TLC
GC
TLC
TLC ....
TLC
GC.
GC.. .
GC
GC
GC..
GC
GC
TLC
TLC
TLC ..
TLC .
GC
GC
TLC
GC ..
GC
GC
GC
GC/MS ... .
GC
608
625
608
•625
606
'625
606
625
608
•625
608
625
608
625
608
625
608
625
S09A
509A
509A
509A
S09A
S09A
509A
509A
S09A
509A
SOBA
509A
509A
509A
5098
5098
509A
509A
03086
03086
03086
03086
03086
03086
03086
03086
O3086
Nott 3 p 1 1 5
Nott 4 p 30' Nota 6 p S73
Nott 3 P 7
Nott 3 p 7* Nota 4 p 30
Nota 4 p 30' Nota 6 p S73
Nott 3 p. Note 6 p SSt.
Nott 3. p 104 Note 6 p S64
Nott 3. p. 7
Nott 3. p 7
Nott 3 p 7 Nota 4 p 30
Nota 4 p 30' Nota 6 p 573.
Nota 3 p 104- Note 6 p S64.
Nota 3 p 104- Note 6 p S64.
Nota 3 p 7- Nota 4 p 30
Nota 3 p 7' Note 4 p 30' Nota
6. p. S73.
Nota 4 p 30- NOW 6 p S73
Now 3 p 104' Note 6 p S64
Note 3 p 25- Note 4 p 30:
NOW 6. p. SSI
Now 3, p. 94- NoM 6 0 S60.
Note 3, p. 7- Note 4 p. 30.
Note 3. p. 94: Note 6. p. S60.
Note 3 p 7
Nota 3. p. 104- Note 6. p. S64.
Note 3. p. 104: Note 6. p. S6*
NoM 3, p. 104; Note 8, p. S64.
NoM 3. p 25; New 4. p. 30.
NOW 3. p. 25.
NOW 3. p. 7.
Now 3. . 83: Now 6. p. S68
Now 3. . 83: Note 6, . S68.
Net* 3. . 83: Now 6. . S88.
NOW 3. 104; NOW 6. . S64.
Now 3. . 94: Not* 6. . S50.
Now 3. . 83: Now 6. . S88.
NOW 3. 104; NOW 6. . S84.
New 3. . 83: Note 6. . S68.
NOW 3. p. 7
NOW 3. P. 104; Note 6. p. S64.
New 3. p. 115: Now 4, p. 35.
Note 3. p. 115.
New 3. p. 83: Note 6. p. S68.
NOW 3. p. 7; NOW 4. p. 30.
Note 3. p. 7
Tibia 10 Not**
' PastiooM ar* listed m ttus tawa by common nam* for ma convcnwnca of the reader. AomooaJ P*»BCK»*» may be found
und*r Tabtt iC. wfi*r* antnea v* natad by cnamtc* nam*.
E-39
-------
TABLE E-7. (Continued)
• The Ml text ol methods 608 ana 625 art given at Append" A. -Test Procedures 'or Analysis of Organ* Pollutants 31
mis Pan '36 Th« standardized test procedure to oe used 10 determine tn« method detection urmt (MOD 'or these test
procedures is given at Appendix 9. "Definition and Procedure for tne Determination of trie Method Detection Limit", of this Pan
•36
' Memoas for 9enz«Jine. Chlorinated Organic Compounds, Pemacftioropnenoi and Pesticides m Water and Wastewater.
U S Environmental Protection Agency. Septemoer. 1978. This EPA puOtication include* thin-layer crvomatography (T|.C)
methods.
4 Methods 'or Analysis of Organic Suostances >n Water." U.S. Geological Survey. Techniques of Water-resources
investigations. Book 5. Chapter A3 (1972).
* The method may Be extended to include a-8MC. 6-BHC. enoosulfavt I. endosuHan n. and endnn. Houwver. omen they are
known to exist. Method 608 » me preferred method.
' "Selected Analytical Methods Approved and Cited by tne United Slates Environmental Protection Agency." Supplement to
tne Fifteenth Edition of Stina»n] MttfioOt lor me Ettmnitxyi ol Wittr ana Wtsttunnr (i9ti)
: Eacn analyst must make an initial, one-time, demonstration of me* aMty to generate aceeptafaM precision and accuracy
•nth Methods 60S and 625 (See Appendn A of this Part 136) in accordance mm procedures gwen in section 8.2 of eacn of
these methods. Additionally, eacn laooratory. on an on-going basis, must spike and anaJyie '0% otaJi samoies analyzed with
Method 608 or SS of all samples analyzed «rtn Method 82$ to monitor and evaluate laooraton/ data quality m accordance
with Sections 8.3 and 8.4 of these methods. When tne recovery of any parameter 'alls outside trie warning limits, tne analytical
results for mat parameter m me unso*ed sample are suspect and cannot be rtoorted to demonstrate regulatory compliance.
: These warning limits are promulgated as an "interim final acton with a request for comments."
E-40
-------
TABLE E-8. RECOHMENOEO SAMPLE SIZES, CONTAINERS. PRESERVATION.
AND HOLDING TIMES FOR EFFLUENT SAMPLES3
Minimum
Sample Sizeb
Measurement (mL)
PH
Temperature
Turbidity
Total suspended solids
Settleable solids
Floating participates
Dissolved oxygen
Probe
Winkler
Biochemical oxygen demand
Total chlorine residual
Oil and grease
Nitrogen
Ammonia-N
Total Kjeldahl-N
Nitrate+Nitrite-N
Phosphorus (total)
Priority pollutant metals
Metals, except mercury
Mercury
Priority pollutant organic
compounds
Extractable compounds
(includes phthalates.
nitrosamines. organo-
chlorine pesticides.
PCBs, nitroaromatics,
isophorone, polycyclic
aromatic hydrocarbons.
haloether, chlorinated
hydrocarbons, phenols.
and TCOO)
Purgeable compounds
25
1.000
100
1.000
1.000
5.000
300
300
1.000
200
1.000
400
500
100
50
100
100
4.000
40
Container0
P. G
P, 6
P. G
P. G
P. G
P. G
G bottle and top
G bottle and top
P. G
P. G
G only
P. G
P. G
P. G
P. G
P. G
P. G
G only,
TFE-lined cap
6 only,
TFE-lined septum
Preaervatl ver
None
None
Cool , 4° C
Cool, 4° C
Cool . 4° C
Nona
None
Fix onsite;
store in dark
Cool . 4° C
None
Cool. 4° C
H2S04 to pH<2
Cool , 4° C
H2S04 to pH<2
Cool. 4° C
H2S04 to pH<2
Cool, 4° C
H2S04 to pH<2
Cool. 4° C
H2S04 to pH<2
HN03 to pH<2
HN03 to pH<2
Cool . 4° C
0.008X Na2S2039
Store in dark
Cool . 4° C
0.008% Na2S2039
Maximum
Holding Time
Analyze i mediately8
Measure immediately6
48 h
7 days
48 h
Analyze immedl atel ye' f
Analyze 1 mediately8
8 h
48 h
Analyze Immediately8
28 days
28 days
28 days
23 days
28 days
6 mo
28 days
7 days until
extraction
40 days after
extractl on
7 daysh
-------
TABLE E-8. (Continued
. Minimum
Sample Size"
Measurement . (ml)
Total and fecal col i form
bacteria 2SO-500
Enterococcus bacteria 2SO-500
Container0 Preservative
P, G Cool . 4° C
0.003X Na^Oj9
P, G Cool . 4° C
0.008* ^2^2^ 2
Maximum
Holding Time
6 h
6 h
a Reference: Adapted from U.S. EPA (1979b), 40 CFR Part 136.
Recommended field sample sizes for one laboratory analysis. If additional laboratory
analyses are required (e.g.. replicates), the field sample size should be adjusted accordingly.
c P « Polyethylene: G - Glass.
° Sample preservation should be performed immediately upon sample collection. For composite
samples, each aliquot should be preserved at the time of collection. Wrier use of an automated
sampler makes it impossible to preserve each aliquot, the samples should be maintained at 4° C
until compositing.
e Immediately means as soon as possible after the sample 1s collected, general ly within 15 mtn
(U.S. EPA 1984).
No recommended holding time is given by U.S. EPA for floating particulates. Analysis should
therefore be made as soon as possible.
' Should only be used in the presence of chlorine residual.
Holding time and preservation technique for purgeable compounds are based on the use of
U.S. EPA Method 624 for screening all priority pollutant volatiles organic compounds, including
acrolein and acrylonitrile. If analysis of acrolein and acryloni tri le is found to be of
concern, a separate subsample should be preserved by adjusting the pH to 4-5 and the sample
should then be analyzed by U.S. EPA Method 603.
E-42
-------
QA/QC
QA/QC procedures should be detailed in the quality assurance project
plan (QAPP) (U.S. EPA 1979c; Tetra Tech 1987). The following items should
be discussed in the QAPP:
• Statement and prioritization of study objectives
• Responsibilities of personnel associated with sample
collection and analysis
• Sampling locations, frequency, and procedures
• Variables to be measured, sample sizes, sample containers,
preservatives, and sample holding times
• Equipment checklist
• Sample splits or performance samples to be submitted with the
samples
• Sample handling, packaging, labeling, and shipping require-
ments
• Laboratories to which samples will be shipped.
Tetra Tech (1987) provides QA/QC guidance for the following activities:
• Preparation for sampling program
• Sample collection
• Sample processing
• Sample size
E-43
-------
• Sample containers
• Sample preservation
• Sample holding times
• Sample shipping
• Recordkeeping
• Labeling
• Custody procedures
• Analytical methods
• Calibration and preventive maintenance
• Quality control checks
• Corrective action
• Data reporting requirements.
Field Sampling Procedures
For the field sampling effort, the following procedures are recommended:
• Establish and implement chain-of-custody protocols to track
samples from the point of collection to final disposition
• Establish and implement protocols to prepare sample containers
E-44
-------
• Prepare field "blank" samples to assess potential sample
contamination by the sampling devices
• Prepare "trip blanks" to assess potential contamination by
volatile organic analytes en route to the laboratory (1 trip
blank per sample shipment)
• Collect replicate samples to assess sample precision and the
homogeneity of samples collected
• Use appropriate sample collection procedures (see Table E-8).
Volatile organic samples and split composite samples should be
collected carefully. Grab samples for volatile organic analyses should be
collected in duplicate. Residual chlorine should be eliminated, and the
volatile sample containers should be filled with a minimum of mixing and to
capacity leaving no headspace. When splitting composite samples into
discrete aliquots for analyses, the composite sample should be mixed to
provide a homogeneous mixture. A representative portion of any solids in
the container should be suspended in the composite sample. Composite
samples may be homogenized by hand stirring with clean glass rods or by
mechanical stirring with teflon-coated paddles. Metal mixing devices should
not be used.
Laboratory Procedures
Laboratory analytical results must be accurate and reliable. Laboratory
QA/QC procedures are generally specified for each different analytical
method, and the level of QA/QC and associated deliverables vary among
methods (Tables E-5 to E-7). The following documentation is required by the
analytical laboratory for QA review of data on organic substances (see
Tables E-6 and E-7):
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• Initial multipoint calibration
• Demonstration of method proficiency
• Determination of method detection limit [usually 5-10 ppb for
base, neutral, and acid organic compounds (U.S. EPA Method
625); 0.005-0.10 ppb for pesticide/PCB analysis (U.S. EPA
Method 608); and 1-10 ppb for volatiles (U.S. EPA Method 624)]
• Daily checks of calibration and instrument tuning
• Daily analysis of method blanks (1 blank/20 samples)
• Analysis of duplicate samples (minimum of 5 percent of
samples analyzed) and conduct of matrix spikes to determine
organic recoveries.
The following documentation is required by the analytical laboratory for QA
review of data on inorganic substances (see Table E-5):
• Multipoint calibration
• Analysis of reagent blanks
• Matrix spikes of 0.5-5 times the sample concentration
• Determination of method detection limits
• Analysis of full method blanks at a minimum frequency of
every 20 samples, rather than reagent water blanks
• Verification of calibration by analysis of standards (daily or
with every 10 sample batches)
E-46
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• Performance of duplicate analyses for a minimum of 5 percent
of the total number of samples analyzed
• Use of the method of standard additions for samples demon-
strating interferences.
Data Evaluation
Data generated from the monitoring program should be evaluated using
the step-wise approach discussed below.
1. Assemble the original raw data reports and the associated QA/QC data.
The analytes and analytical methods used will determine the types of
QA/QC data generated, and may include the following:
• Sample results
• Blank sample results
• Instrument calibrations (initial and continuing)
• Matrix spike/matrix spike duplicate results
• Surrogate recovery data
• Instrument tuning data
• Chain-of-custody records
• Analytical request forms
• Gas chromatograms
• Mass spectra
E-47
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• Instrument detection limit determinations
• Serial dilution results
• Clean-water precision and accuracy studies
• Furnace atomic absorption quality control data
• Interference check data
• Laboratory control sample results
• Holding time documentation.
2. Because the resulting data will be used to determine regulatory
compliance of the discharge, the following sequence is recommended to
conduct a QA review of the data:
• Confirm the sample identifier, container, and preservation
with chain-of-custody records
• Confirm the analytical (e.g., extraction or digestion)
procedure used with the procedure requested
• Confirm that an acceptable instrument detection limit was
achieved
• Confirm that the analysis proceeded in the manner specified
• Confirm that all quality control data deliverables specified
by the analytical protocol have been submitted
• Confirm that the analysis was performed within the specified
sample holding time
E-48
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Confirm that the instrumentation used was properly calibrated
initially and that the method was validated
Confirm detection limits, precision, and accuracy for each
substance and review duplicate analysis results
Confirm that blank samples were analyzed and that the field
sampling and analytical procedures did not contaminate the
data
Evaluate the presence of matrix interferences through the use
of surrogate recoveries and matrix spikes
Annotate the data with appropriate qualifiers, and note
deviations from prescribed methods
Detail problems associated with the analyses.
E-49
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UPGRADING TO A FULL-SCALE SECONDARY TREATMENT FACILITY
Data obtained from the monitoring program described above will be used
to determine the mean and peak concentrations and site-specific toxic
pollutant removal capabilities for secondary treatment. Performance of the
secondary treatment pilot plant will be closely related to the attention and
expertise of the operator controlling the plant. If the pilot plant is not
properly operated, the data will not approximate the removals that could be
achieved with a full-scale facility. Conventional pollutant data (e.g.,
suspended solids, BOD) can be used to determine when the pilot plant is
operating within the expected design removal efficiencies. The most
important factor in performing site-specific toxic pollutant removal
investigations is to ensure that an acclimated biological seed exists prior
to initiating sample collection for pollutant analyses.
Plant operators should be aware that activated sludge microorganisms are
susceptible to biological and chemical effects that may kill the organisms
or severely inhibit their effectiveness. Accumulations of toxic waste
components (via gradual concentration from continuous discharges, or sudden
slugs) could limit the ability of the activated sludge system to achieve
design effluent quality (see Tables E-9 and E-10). Disruptions or changes
could be found by reviewing operating records (e.g., settling characteristics
of secondary sludge, species populations in the MLSS). If inhibition or
upset conditions are found, the concentration and source of each pollutant of
concern should be determined. Concentrations shown in Tables E-9 and E-10
are not absolute and should be used only for comparison purposes and
preliminary investigations.
Toxic pollutant removal efficiencies at the secondary treatment pilot
plant may be greater than those expected in a full-scale secondary treatment
facility. The pilot plant will be operated at a constant flow rate and will
not be subject to the diurnal and seasonal flow fluctuations normally
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TABLE E-9. REPORTED VALUES FOR ACTIVATED SLUDGE BIOLOGICAL
PROCESS TOLERANCE LIMITS OF ORGANIC PRIORITY POLLUTANTS
Threshold of
Pollutant Inhibitory Effect (mg/L)a
Acenaphthene NIb at 10
Acrolein NI at 62
Acrylonitrile NI at 152
Benzene 125
Benzidine 5
Carbon tetrachloride NI at 10
Chlorobenzene NI at 1
1,2,4-Trichlorobenzene NI at 6
Hexachlorobenzene 5
1,2-Dichloroethane NI at 258
1,1,1-Trichloroethane NI at 10
Hexachloroethane NI at 10
1,1-Dichloroethane NI at 10
1,1,2-Trichloroethane NI at 5
1,1,2,2-Tetrachloroethane NI at 201
Ms-(2-Chloroethyl) ether NI at 10
2-Chloroethyl vinyl ether NI at 10
2-Chloronaphthalene NI at 10
2,4,6-Trichlorophenol 50
porc-Chloro-OTeto-cresol NI at 10
Chloroform NI at 10
2-Chlorophenol NI at 10
1,2-Dichlorobenzene 5
1,3-Oichlorobenzene 5
1,4-Dichlorobenzene 5
1,1-Dichloroethylene NI at 10
1,2-trcrns-Dichloroethylene NI at 10
2,4-Dichlorophenol NI at 75
1,2-Dichloropropane NI at 182
1,3-Dichloropropylene NI at 10
2,4-Dimethyl phenol NI at 10
2,4-Dinitrotoluene 5
2,6-Dinitrotoluene 5
1,2-Diphenylhydrazine 5
Ethyl benzene NI at 10
Fluoranthene NI at 5
E-51
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TABLE E-9. (Continued)
Threshold of
Pollutant Inhibitory Effect (rag/L)a
Ms-(2-Chloroisopropyl) ether Nlb at 10
Chloromethane NI at 180
Bromoform NI at 10
Dichlorobromomethane NI at 10
Trichlorofluoromethane NI at 10
Chlorodibromomethane NI at 10
Hexachlorobutadiene NI at 10
Hexachlorocyclopentadiene NI at 10
Isophorone NI at 15.4
Naphthalene 500
Nitrobenzene 500
2-Nitrophenol NI at 10
4-Nitrophenol NI at 10
2,4-Dinitrophenol 1
N-Nitrosodiphenylamine MI at 10
N-Nitroso-di-N-propylamine . MI at 10
Pentachlorophenol 0.95
Phenol 200
Ms-(2-Ethyl Hexyl) phthalate MI at 10
Butyl Benzyl phthalate NI at 10
Di-n-butyl phthalate NI at 10
Di-n-octyl phthalate NI at 16.3
Oiethyl phthalate NI at 10
Dimethyl phthalate NI at 10
Chrysane NI at 5
Acenaphthylene NI at 10
Anthracene 500
Fluorene NI at 10
Phenanthrene 500
Pyrene NI at 5
Tetrachloroethylene NI at 10
Toluene NI at 35
Trichloroethylene NI at 10
Aroclor-1242 NI at 1
Aroclor-1254 NI at 1
Aroclor-1221 NI at 1
Aroclor-1232 NI at 10
Aroclor-1016 NI at 1
a Unless otherwise indicated.
b NI = no inhibition at tested concentrations. No concentration is listed if
reference lacked concentration data.
Reference: U.S. EPA (1986c).
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TABLE E-10. REPORTED VALUES FOR ACTIVATED SLUDGE BIOLOGICAL
PROCESS TOLERANCE LIMITS OF INORGANIC PRIORITY POLLUTANTS
Threshold of
Pollutant Inhibitory Effect (mg/L)
Arsenic
Cadmium
Chromium (VI)
Chromium (III)
Copper
Cyanide
Lead
Mercury
Nickel
Silver
Zinc
0.1
1
1
10
1
0.1
0.1
0.1
1
5
0.03
Reference: U.S. EPA (1986c).
E-53
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experienced at treatment facilities, nor the slug loadings and batch
discharges which POTWs can experience in daily operation. In addition, at
the relatively higher aeration rates of the pilot plant system, higher
degrees of volatile organics stripping may occur, thereby implying higher
levels of removal of biodegradable material than might actually happen under
full-scale situations.
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DEMONSTRATING COMPLIANCE USING PILOT PLANT DATA
The purpose of operating a secondary treatment pilot plant is to
determine the concentrations of toxic substances in the effluent that would
be realized if the applicant were providing secondary treatment, rather than
less-than-secondary treatment as requested in the 301(h) application.
Effluent from the secondary treatment pilot plant is then analyzed to
determine the concentration of each toxic substance in the effluent. These
concentrations define the maximum allowable concentrations in the discharge
of less-than-secondary treated effluent.
To demonstrate secondary equivalency, the applicant must demonstrate
that the concentration of each toxic substance in the effluent of the
Section 301(h) modified discharge is equal to, or less than, the concen-
tration achieved using the secondary treatment pilot plant. For toxic
substances whose concentration in the Section 301(h) modified discharge
is greater than the concentration in the secondary treated effluent,
the applicant must lower the concentration using either or both of two
approaches. The first approach is to establish local limits for such
substances, in accordance with the guidance given above. The second
approach is to upgrade the treatment process within the POTW. Having
implemented either or both of these approaches, the applicant must then
provide results of additional effluent analyses to demonstrate that the
maximum allowable concentrations of toxic substances are not being exceeded
after the proposed controls have been implemented.
E-55
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REFERENCES
American Public Health Association/American Water Works Association/Water
Pollution Control Federation. 1985. Standard methods for the examination
of water and wastewater (16th ed). Port City Press, Baltimore, MD. 1268 pp.
Tetra Tech. 1982a. Design of 301(h) monitoring programs for municipal
wastewater discharges to marine waters. EPA 430/9-82-010. Prepared for
U.S. EPA, Office of Marine Discharge Evaluation, Washington DC. Tetra Tech,
Inc., Bellevue, WA. 135 pp.
Tetra Tech. 1982b. Revised Section 301(h) technical support document. EPA
430/9-82-011. Prepared for U.S. EPA, Office of Water, Washington, DC.
Tetra Tech, Inc., Bellevue, WA. 248 pp.
Tetra Tech. 1986a. Analytical methods for EPA priority pollutants and
301(h) pesticides in estuarine and marine sediments. Final Report. Prepared
for the Marine Operations Division, Office of Marine and Estuarine Protec-
tion, U.S. Environmental Protection Agency. EPA Contract No. 68-01-6938.
Tetra Tech, Inc. Bellevue, WA. 120 pp.
Tetra Tech. 1986b. Bioaccumulation monitoring guidance: 4. analytical
methods for U.S. EPA priority pollutants and 301(h) pesticides in tissues
from estuarine and marine organisms. Final Report. Prepared for the Marine
Operations Division, Office of Marine and Estuarine Protection, U.S.
Environmental Protection Agency. EPA Contract No. 68-01-6938. Tetra Tech,
Inc. Bellevue, WA. 118 pp.
Tetra Tech. 1987. Quality assurance/quality control (QA/QC) for 301(h)
monitoring programs: guidance on field and laboratory methods. EPA 430/9-
86-004. Prepared for U.S. EPA, Office of Marine and Estuarine Protection,
Washington, DC. Tetra Tech, Inc., Bellevue, WA. 277 pp.
U.S. Environmental Protection Agency. 1979a. NPDES compliance sampling
manual. MCD-51. U.S. EPA, Enforcement Division, Office of Water Enforcement
Compliance Branch, Washington, DC. 138 pp.'
U.S. Environmental Protection Agency. 1979b (revised March 1983). Methods
for chemical analysis of water and wastes. EPA 600/4-79-020. U.S. EPA,
Environmental Monitoring and Support Laboratory, Cincinnati, OH.
U.S. Environmental Protection Agency. 1979c. Handbook for analytical
quality control in water a.id wastewater laboratories. U.S. EPA, National
Environmental Research Center, Cincinnati, OH.
U.S. Environmental Protection Agency. 1982c. Handbook for sampling and
sample preservation of water and wastewater. EPA 600/4-82-029. U.S. EPA,
Environmental Monitoring and Support Laboratory, Cincinnati, OH. 402 pp.
E-56
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U.S. Environmental Protection Agency. 1983a. Guidance manual for POTW
pretreatment program development. U.S. EPA, Office of Hater Enforcement and
Permits, Washington, DC. 270 pp.
U.S. Environmental Protection Agency. 1983b. Procedures manual for
reviewing a POTW pretreatment program submission. U.S. EPA, Office of Water
Enforcement and Permits, Washington, DC. 125 pp.
U.S. Environmental Protection Agency. 1984a. NPDES compliance inspection
manual. U.S. EPA, Office of Water Enforcement and Permits, Washington, DC.
159 pp.
U.S. Environmental Protection Agency. 1984b. Report on the implementation
of Section 301(h). EPA 430/9-84-007. U.S. EPA, Office of Water Program
Operations. Washington, DC. 79 pp.
U.S. Environmental Protection Agency. 1985a. Guidance manual for implemen-
ting total toxic organics (TTO) pretreatment standards. U.S. EPA, Permits
Division, Washington, DC. 86 pp.
U.S. Environmental Protection Agency. 19855. Guidance manual for the use of
production-based pretreatment standards and the combined wastestream
formula. U.S. EPA, Permits Division and Industrial Technology Division,
Washington, DC. 82 pp.
U.S. Environmental Protection Agency. 1986a. Pretreatment compliance
monitoring and enforcement guidance. U.S. EPA, Office of Water Enforcement
and Permits, Washington, DC. 135 pp.
U.S. Environmental Protection Agency. 1986b. Pretreatment compliance
inspection and audit manual for approval authorities. U.S. EPA, Office of
Water Enforcement and Permits, Washington, DC. 107 pp.
U.S. Environmental Protection Agency. 1986c. Report to Congress on the
discharge of hazardous wastes to publicly owned treatment works (the
domestic sewage study). EPA 530-SW-86-004. U.S. EPA, Office of Water
Regulations and Standards, Washington, DC. 450 pp.
U.S. Environmental Protection Agency. 1987a. Guidance manual for preventing
interference at POTWs. U.S. EPA, Office of Water Enforcement and Permits,
Washington, DC. 113 pp.
U.S. Environmental Protection Agency. 1987b. Guidance for reporting and
evaluating POTW noncompliance with pretreatment implementation requirements.
U.S. EPA, Office of Water Enforcement and Permits, Washington, DC. 23 pp.
U.S. Environmental Protection Agency. 1987c. Guidance manual on the
development and implementation of local discharge limitations under the
pretreatment program. U.S. EPA, Office of Water Enforcement and Permits,
Washington, DC. 355 pp.
E-57
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Water Pollution Control Federation. 1976. Manual of practice No. 11 - oper-
ation of wastewater treatment plants. Lancaster Press, Inc., Lancaster, PA.
pp. 117-160.
Water Pollution Control Federation. 1987. Manual of practice OM-9,
activated sludge. WPCF, Alexandria, VA, 182 pp.
Water Pollution Control Federation/American Society of Civil Engineers.
1977. Wastewater treatment plant design. Lancaster Press, Inc., Lancaster,
PA. pp. 217-282.
E-58
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ATTACHMENT 1 TO APPENDIX E
U.S. EPA OFFICE OF WATER ENFORCEMENT AND PERMITS
PROCEDURES FOR DEVELOPING TECHNICALLY BASED LOCAL LIMITS
E-59
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U.S. EPA OFFICE OF WATER ENFORCEMENT AND PERMITS PROCEDURES
FOR DEVELOPING TECHNICALLY BASED LOCAL LIMITS
INTRODUCTION
Publicly owned treatment works (POTWs) which discharge wastewater
into marine waters may be granted a waiver under Section 301(h) of the
Clean Water Act (CWA) from the requirement for secondary treatment [Sec-
tion 301(b)(l)(B)]. The Water Quality Act (WQA) of 1987 added a new
requirement, the urban area pretreatment program, to Section 301(h) of the
CWA for POTWs serving a population of 50,000 or more with respect to toxic
pollutants introduced by industrial dischargers. This provision now requires
each applicant to demonstrate that it has a pretreatment program in effect
for each toxic pollutant which, in combination with the applicant's own
treatment of discharges, removes the same amount of a given toxic pollutant
as would be removed if the applicant were to apply secondary treatment (as
defined in 40 CFR Part 133) and if it had no pretreatment program for the
toxic pollutant. This new "secondary removal equivalency" requirement
applies only with respect to a toxic pollutant introduced into a POTW by an
industrial discharger for which there is no "applicable pretreatment in
effect."
Under this new provision, for each toxic pollutant introduced by an
industrial user, the applicant must demonstrate either that there is an
applicable pretreatment requirement in effect or that it has a secondary
removal equivalency program for any toxic pollutant from industrial sources
for which there is no applicable pretreatment requirement. Applicable
pretreatment requirements may take the form of Federal categorical pretreat-
ment standards, local limits developed in accordance with 40 CFR Part 403,
or a combination thereof.
E-60
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POTWs must demonstrate that local limits developed are adequate and
enforceable. This new CWA provision also requires POTWs to demonstrate that
industrial sources are in compliance with all of their pretreatment
requirements, including numerical standards set by local limits, and that
those requirements will be enforced.
The following discussion provides a review of procedures for developing
technically-based local limits. Further details on the various approaches
are provided in U.S. EPA's Guidance Manual on the Development and Implemen-
tation of Local Discharge Limitations Under the Pretreatment Program
(December 1987). Questions about this guidance should be directed to the
U.S. EPA Regional Pretreatment Coordinators or to The Office of Water
Enforcement and Permits in Washington, DC.
OVERVIEW OF LOCAL LIMITS
Local discharge limitations are requirements developed by a POTW based
on local conditions and unique requirements at the POTW. These limits are
primarily intended to protect the treatment plant from industrial discharges
which could interfere with POTW treatment processes or pass through the
treatment plant to receiving waters and adversely impact water quality.
Local limits are also designed to prevent sludge contamination and protect
workers at the treatment plant.
Local limits are usually developed on a chemical specific basis and are
implemented as requirements that individual industrial dischargers must
meet. Once adopted, local limits are deemed to be Federal standards for the
purposes of the Clean Water Act Section 307(d) prohibition against violating
pretreatment standards [40 CFR 403.5(d) and 40 CFR 403.3(j)].
LOCAL LIMITS DEVELOPMENT APPROACHES
U.S. EPA's Guidance on the Development and Implementation of Local
Discharge Limitations Under the Pretreatment Program (1987) provides
various methods for calculating local limits. The predominant approach
E-61
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used by POTWs and advocated in the Guidance is a chemical specific approach
known as the maximum allowable headworks loading method. This method
involves back calculating from environmental and plant protection criteria
to a maximum allowable headworks loadings. This is accomplished pollutant
by pollutant for each environmental criteria or plant requirement and the
lowest or most limiting value for each pollutant serves as the basis for
allocation to industry and ultimate local limits. The steps of the maximum
allowable headworks loading local limits development process are shown in
Figure 1, and discussed below.
Maximum Allowable Headworks Loadino Method
Determine Applicable Environmental Criteria--
The first step in developing local limits by the maximum allowable
headworks loading method is to determine applicable environmental criteria.
Environmental criteria generally include NPOES permit limits, water quality
standards or criteria, sludge disposal requirements, and unit process
inhibition values. The POTW should use all applicable environmental
criteria when developing local limits. Other appropriate requirements may
include worker health and safety criteria, collection system effects,
incinerator emission requirements or other applicable federal, state, or
local environmental protection requirements. Further information on how to
incorporate applicable environmental criteria into the local limits
development process is contained in the guidance manual.
Another less frequently used environmental criterion is biological
toxicity. POTWs that have conducted biological toxicity testing indicating
toxicity should develop local limits to correct the toxicity. Although
there is no method in the guidance manual to calculate maximum allowable
headworks loadings based on the results of toxicity testing, the manual
provides guidance and additional references on the Toxicity Reduction
Evaluation (TRE) process.
E-62
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Characterize Existing Loadings--
Industrial Users—During the local limits development process, the POTW
must characterize existing loadings to the treatment plant. Local limits
should be based on site-specific monitoring data. This can be accomplished
by conducting monitoring of all industrial users. Either POTW monitoring
or self-monitoring data are acceptable, and information from the POTW's
industrial waste survey may also be of use.
Hauled Waste—If hauled wastes are accepted at the POTW, they may be a
significant source of toxic pollutant loadings. In such a case the POTW
should consider them as a significant nondomestic source in the determina-
tion of local limits.
Domestic Loadings—The POTW must also characterize domestic loadings.
Site-specific monitoring of a representative portion of the POTW's collection
system should form the basis for loadings from domestic/background sources.
Use of literature values must be justified by the POTW.
Treatment Plant Monitoring—The POTW must conduct sufficient monitoring
at the treatment plant to characterize influent, effluent, and sludge
loadings. Monitoring of the treatment plant influent, effluent, and sludge
should represent a minimum of 5 consecutive days. Preferably, monitoring
should include data for at least 1 day per month over at least 1 yr for
metals and other inorganic pollutants, and 1 day of sampling per year for
toxic pollutants [priority pollutants and Resource Conservation and Recovery
Act (RCRA) Appendix 9 constituents].
Determine Pollutants of Concern--
As one approach for achieving compliance with Section 301(h) regula-
tions, POTWs serving a population of 50,000 or more must demonstrate that
applicable pretreatment requirements are in effect for any and all toxic
pollutants contributed by an industrial user. Therefore, data should be
collected for any toxic pollutants of concern that could reasonably be
E-63
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expected to be discharged to the POTW In quantities that could pass through
or interfere with the POTW treatment process, contaminate the sludge, or
jeopardize worker health and safety or the collection system.
The POTW should perform at least one priority pollutant scan and one
RCRA Appendix 9 scan to identify potential pollutants of concern in the
influent, effluent, and sludge. The POTW must then address all toxic
pollutants (40 CFR 401.15) that are identified in any analysis above
detection limits by developing a local limit for each pollutant.
Calculate Maximum Headworks Loadings—
The POTW must calculate the maximum amount (Ib/day) of each toxic
pollutant contributed by an industrial user or received at the headworks of
the treatment plant that will allow the POTW to achieve all of the above
applicable environmental criteria. If the POTW does not calculate the
maximum allowable headworks loading to the POTW for each toxic pollutant, it
must provide justification why it has not done so. The nonconservative
pollutants (volatiles) require special consideration when conducting
headworks analysis (e.g., alternative formulas and allocation methods). All
calculations should be consistent with the approach outlined in the guidance
manual.
During this step of the local limits development process, the POTW
should demonstrate that an acceptable mass balance exists between the actual
loadings of pollutants at the headworks and the estimated loadings of
pollutants from specific source discharges. This mass balance can be
accomplished by calculating the actual loading of each pollutant from
influent monitoring data and comparing this value with the sum of the
estimated loadings from all individual sources (e.g., domestic, industrial,
hauled waste). The resulting calculated loadings from various sources
should be within 80 to 120 percent of the actual total influent loading and
flow.
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Calculate Allowable Industrial Loadings—
Once the POTW has calculated the maximum allowable headworks loading,
a safety factor must be applied and the value discounted for domestic/back-
ground loadings in order to determine the maximum allowable allocation
available for industrial users. A safety factor is incorporated into
the calculations to allow for future industrial growth and other dis-
crepancies that may enter into the calculations because of the use of
default data or variations in analytical procedures. The POTW should
provide justification for the selected safety factor, which will usually
range from 10 to 30 percent.
Allocate Allowable Industrial Loading--
After the POTW has calculated the allowable industrial loading, the
method chosen to allocate this loading depends on the number and types of
industrial users and the method of application (permits, contract, or sewer
use ordinance) employed by the POTW. Where the current loading of a
pollutant exceeds the maximum allowable headworks loading, the POTWs must
establish a local limit to reduce loadings to within the range of the
maximum allowable headworks loading. Where the current loading is far below
or approaches the maximum allowable headworks loading, the POTW must set
industrial discharge limits at current loadings to maintain the status quo.
The POTW should ensure that it has selected local limits that are
reasonable. All local limits should be at or above detection limits and
should not be so lenient as to provide industry additional opportunity to
pollute or encourage discharge of hazardous waste to the POTW.
Revise Local Limits--
Many variables on which these local limits calculations are based may
vary with time. Local limits must be revised on a periodic basis to reflect
changes in conditions or assumptions. Conditions which might require that
local limits be revised include but are not limited to changes in environ-
E-65
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mental criteria, availability of additional monitoring data, changes in
plant processes, and changes in POTW capacity or configuration.
Implement Local Limits--
Once local limits have been developed, they must be effectively
implemented. Local limits should be incorporated into the sewer use
ordinance or some form of individual control mechanisms.
OTHER LOCAL LIMITS APPROACHES
Other methods of local limits development have been used by POTWs.
They include the collection system approach, industrial user management
practice plans, and case-by-case discharge limits. These approaches are
briefly described below. U.S. EPA has published extensive guidance on the
development and implementation of local limits. Further information on each
of these methods and the maximum allowable headworks loading method can be
found in the Guidance Manual on the Development and Implementation of Local
Discharge Limitations Under the Pretreatment Program (U.S. EPA 1987).
Collection System Approach
To apply this method, the POTW identifies pollutants that may cause
fire and explosion hazards or other worker health and safety concerns.
Pollutants found to be present are evaluated for their propensity to
volatilize and are simplistically modeled to evaluate their expected
concentration in air. Comparisons are made with worker health exposure
criteria and lower explosive limits. Where values are of concern, the POTW
may set limits or require development of management practices to control
undesirable discharges. The collection system approach may also consider
the prohibition of pollutants with specific flashpoints to prevent discharge
of ignitable wastes.
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Industrial User Management Practice Plans
This approach consists of POTWs requiring industrial users to develop
management practices as enforceable pretreatment requirements for the
handling of chemicals and wastes. Examples of management practice plans
include chemical management practices, best management practices, and spill
prevention plans. Management practice plans are usually narrative local
limits.
Case-bv-Case Discharge Limits
In this approach a POTW sets numeric local limits based on best
professional judgment and on available technologies that are known to be
economically feasible. This approach is most often used when insufficient
data are available to employ the other methods noted above.
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ATTACHMENT 2 TO APPENDIX E
U.S. EPA GUIDANCE MANUAL ON THE DEVELOPMENT AND
IMPLEMENTATION OF LOCAL DISCHARGE LIMITATIONS
UNDER THE PRETREATMENT PROGRAM
E-68
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APPENDIX F
WATER QUALITY-BASED TOXICS CONTROL
-------
WATER QUALITY-BASED TOXICS CONTROL
Most applicants for Section 301(h) modified NPDES permits must
demonstrate satisfactorily to the U.S. EPA that discharge from the POTWs to
the marine or estuarine waters is in compliance with Section 301(h) of the
Clean Water Act (CWA). POTWs must enforce all applicable industrial
pretreatment requirements and demonstrate the effectiveness of both
industrial and nonindustrial source control programs. (Small dischargers,
with service area populations of less than 50.000 people and average dry
weather flows of less than 5.0 MGD, are exempt from effluent analysis and
industrial pretreatment requirements if they can certify that there are no
known or suspected sources of toxic pollutants or pesticides to the POTW.)
Section 301(h) industrial source control programs must be consistent with
pretreatment regulations and NPDES permit requirements. Under Sections 308
and 402 of the CWA, NPDES permit applicants [including 301 (h) POTWs] are
required to collect effluent chemical (and possibly toxicity) data and
receiving water biological data to assure compliance with state water
quality standards. [If no state standards have been developed for specific
pollutants at the time of permit issuance, small and large dischargers must
then meet U.S. EPA's marine water quality criteria at the boundary of the
zone of initial dilution (ZID).]
In 1984, U.S. EPA (1984) recommended that whole-effluent toxicity
testing be used as a complement to chemical-specific analyses to assess
effluent discharges and determine NPDES permit limitations. [U.S. EPA
developed this approach because of certain disadvantages of the chemical -
specific techniques (i.e., the difficulty in identifying all potentially
toxic pollutants; the antagonistic, synergistic, or additive effects of
toxic pollutants; and the possibility of complex chemical interactions).]
The integrated approach is recommended to assure the attainment of water
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quality standards, to protect designated water uses, and to provide a tool
to control pollutants beyond the CWA technology-based requirements [e.g.,
Best Available Technology Economically Achievable (BAT)].
The Water Quality Act (WQA) of 1987 also emphasized the need for an
integrated approach of whole-effluent and chemical-specific analyses.
Congress required U.S. EPA to report on methods for establishing and
measuring water quality criteria for toxic pollutants through the use of
biological monitoring and assessment methods, and pollutant-specific
analyses. The WQA also signalled a shift in emphasis from discharge
requirements that were based primarily on technology-based pollution
controls to requirements that combined both technology-based and water
quality-based pollution controls.
In 1985, U.S. EPA's Office of Water Enforcement and Permits (OWEP) and
the Office of Water Regulations and Standards (OWRS) prepared the Technical
Support Document for Voter Quality-based Toxics Control (U.S. EPA 1985a).
Guidance was provided on the implementation of a biomom'toring policy for
the assessment and control of toxics using both the chemical-specific
approach and the whole-effluent toxicity approach. The chemical-specific
approach uses water quality criteria or state standards to limit specific
pollutants directly. The whole-effluent toxicity approach, as described in
the technical support document predominantly for non-marine waters, involves
the use of test organisms [e.g., Daphnia spp. (water flea), Pimephales
Promelas (fathead minnow)] that are exposed to serial dilutions of municipal
or industrial effluent/receiving water to measure acute (rapid response)
and/or chronic (long term response) toxicity. The document also provided
guidance for each step in the water-quality based toxics control program,
including the development of water quality standards and criteria, effluent
characterization, health hazard assessment, wasteload allocation, permit
requirements, and compliance monitoring.
In 1985, the U.S. EPA also issued a manual that established standardized
methods for measuring the acute toxicity of effluents to freshwater and
marine organisms (U.S. EPA 1985b) and the chronic toxicity of effluents to
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freshwater organisms (U.S. EPA 1985c). In 1988, U.S. EPA released a
document that established standardized methods for estimating the chronic
toxicity of effluents to marine and estuarine organisms (U.S.; EPA 1988).
Chronic toxicity test methods were provided for five species: the sheepshead
minnow (Cyprinodon variegatus), the inland silverside (Menidia beryllina),
the mysid (Mysidopsis bahia), the sea urchin (Arbacia punctulata) and the
red macroalga (Champia parvula). However, because these tests use non-
indigenous species to estimate the chronic toxicity of effluents and
receiving waters to marine and estuarine organisms, test results may not
necessarily reflect actual field conditions within or near the ZID.
Moreover, test results may not accurately represent impacts of pollutant
discharges on balanced indigenous populations (BIPs).
U.S. EPA developed a permit writer's guide (U.S. EPA 1987) to assist
state and Federal NPDES permit writers in establishing water quality-based
permit limits for toxic pollutants. To meet these water quality-based
limits, the U.S. EPA is continuing to develop criteria that will assist
states in establishing their water quality standards and effluent permit
limitations. The U.S. EPA criteria under development include recommended
magnitudes, durations, and allowable frequencies of exceedance of pollutant
concentrations for both acute and chronic biological effects. POTW permit
limits on effluent toxicity could be imposed, and the NPDES permittee would
be required to conduct a toxicity reduction evaluation (TRE) and implement,
if necessary, a toxics control program (TCP) (U.S. EPA 1985a, 1987).
The TRE, a critical component of the TCP, must be conducted to identify
effluent toxicity sources, to determine (if possible) specific pollutants
responsible for the toxicity, and to identify source control options. The
TRE includes a review of the magnitude and extent of the toxicity problem,
the discharge characteristics, the receiving water characteristics, the need
for additional monitoring to determine water quality/toxicity effects and
chc other potential point and nonpoint toxicity sources in the POTW service
area.
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Because all NPDES-permitted discharges are unique, no single effluent
TRE procedure is applicable to every case. A TCP must be developed on an
individual case-by-case basis, and must include an evaluation of the impact
of 1) the existing POTW wastewater treatment process, 2) point and nonpoint
contributors to the POTW influent, 3) types of industries in the POTW
service area,. 4) the variability, toxicity, and treatability of chemicals
in the effluent; and 5) the variability in species sensitivity based on
whole-effluent toxicity test results. Either technology-based or water
quality-based) source control options also need to be evaluated to determine
their effectiveness in reducing effluent toxicity and alleviating the water
quality violations.
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REFERENCES
U.S. Environmental Protection Agency. 1984. Development of water quality-
based permit limitations for toxic pollutants; national .policy U.S.. EPA,
Washington, DC. Federal Register Vol. 49, No. 48. pp. 9016-9019.
U.S. Environmental Protection Agency. 1985a. Technical support'document
for water quality-based toxics control. EPA 440/4-85-032. U.S. EPA Office
of Water, Washington, DC. 74 pp. + appendices.
U.S. Environmental Protection Agency. 1985b. Methods for measuring the
acute toxicity of effluents to freshwater and marine organisms. EPA 600/4-
85-013. U.S. EPA Environmental Monitoring and Support Laboratory, Cincin-
nati, OH.
U.S. Environmental Protection Agency. 1985c. Short-term methods for
estimating the chronic toxicity of effluents and receiving waters to
freshwater organisms. EPA 6QO/4-85-014. U.S. EPA Environmental Monitoring
and Support Laboratory, Cincinnati, OH.
U.S. Environmental Protection Agency. 1987. Permit writer's guide to
water quality-based permitting for toxic pollutants. EPA 440/4-87-005.
U.S. EPA Office of Water, Washington, DC.
U.S. Environmental Protection Agency. 1988. Short-term methods for
estimating the chronic toxicity of effluents and receiving waters to marine
and estuarine organisms. EPA 600/4-87-028. U.S. EPA Environmental
Monitoring and Support Laboratory, Cincinnati, OH.
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