EPA
-United States
Environmental Protection
Agency
Office of'Water
(4S04F)
EPA 842-B-94-007
-September T994
Amended Section 301 (h)
Technical Support
Document
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EPA 842-B-94-007
September 1994
Amended Section 301 (h) Technical
Support Document
Oceans and Coastal Protection Division (4504F)
Office of Wetlands, Oceans and Watersheds
United States Environmental Protection Agency
Washington, DC 20460
Recycled/Recyclable
Printed with Soy/Canda Ink on papartnat
contains at least 50% recycled fber
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CONTENTS
vii
FIGURES j
^ vii
TABLES
viii
PREFACE
ix
ACKNOWLEDGMENTS \ "."• '
x
EXECUTIVE SUMMARY
1
INTRODUCTION
; 3
BACKGROUND " '
6
PURPOSE AND SCOPE :
STATUTORY CRITERIA AND REGULATORY REQUIREMENTS - 9
14
40 CFR Part 122 _ 15
40 CFR Part 125, Subpart G
22
DEMONSTRATIONS OF COMPLIANCE BY PERMITTEES - -
... 23
APPLICATION FORMAT
24
REQUIRED DATA ']"."•'
24
INTEGRATION OF DATA WITH EPA DATABASES -
*
25
I. Introduction
26
II. General Information and Basic Data Requirements
26
A. Treatment System Description
fjf-
1 Current, Improved or Altered Discharge 2?
2 Description of Treatment/Outfall System 2g
3. Primary or Equivalent Treatment Requirements ^
4. Effluent Limitations and Characteristics
in
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CONTENTS (continued)
Pas
5. Effluent Volume and Mass Emissions
6. Average Daily Industrial Flow 33
7. Combined Sewer Overflows 34
8. Outfall/Diffuser Design 34
: 35
B. Receiving Water Description
36
1. Discharge to Ocean or Saline Estuary
2. Discharge to Stressed Waters 36
3. Seasonal Circulation Patterns ' " 37
4. Oceanographic Conditions 38
5. Previously Discharged Effluent ......''' 39
7.
C. Biological Conditions
45
1. Representative Biological Communities
2. Distinctive Habitats of Limited Distribution ' 4f
J. Commercial and Recreational Fisheries 48
49
D. State and Federal Laws
50
1. Applicable Water Quality Standards
2. Water Use Classification 50
3. Consistency with Coastal Zone, Marine' Sanctuary/and 5°
Endangered Species Laws . .
4. Consistency with Other State "and Federal Laws' .'.'.'.'.'.'.' 52
EL Technical Evaluation
52
A. Physical Characteristics of Discharge
5 52
1. Critical Initial Dilution
2. Dimensions of the ZED 52
3. Effects of Ambient Currents and Stratification on 56
Dispension and Transport of the Wastefield
4. Significant Sedimentation of Suspended Solids ?5
S. Sedimentation of Suspended Solids 60
60
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CONTENTS (continued)
Pas
B. Compliance with Applicable Water Quality Standards and Criteria 61
1. Dissolved Oxygen . . , : . . . 61
2. Farfield Dissolved Oxygen Depression I 61
3. Dissolved Oxygen Depression Due to Steady Sediment Demand
and Sediment Resuspension , 61
4. Suspended Solids 62
5. PH 62
6. Compliance with Applicable Water Quality Standards 65
7. Water Quality Criteria at the ZED Under Critical Conditions 66
8. Compliance with 40 CFR 125.61(b)(2) . . 77
C. Impact on Public Water Supplies ....*.... 77
1. Presence of a Public Water Supply Intake : 77
2. Effects on Such Intake 78
D. Biological Impact of Discharge 78
1. Presence of a BIP • • • 80
2. Effects on Distinctive Habitats of Limited Distribution 83
3. Effects on Commercial and Recreational Fisheries 85
4. Other Impacts Within or Beyond the ZED 87
5. Other Impacts for Discharges into Saline Estuarine Waters 92
6. Compliance with 40 CFR 125.62(a)-(d) for Improved Discharges 95
7. Compliance with 40 CFR 125.62(a)-(d) for Altered Discharges 95
8. Stressed Ocean Waters . . 95
I
E. Impacts of Discharge on Recreational Activities 96
1. Activities Likely to be Affected 96
2. Impacts, including Discussion of Fecal Coliform Bacteria . 97
3. Federal, State, or Local Restrictions . ;. 97
4. Modification of Such Restrictions under Secondary Treatment 98
F. Establishment of a Monitoring Program ; . . . . 98
".•.•'.; • .• ' - - - • • • - j
1. Biological, Water Quality, and Effluent Monitoring Programs 100
2. Sampling Techniques, Schedules, Locations, Analytical
Techniques, Quality Control, and Verification Procedures 107
3. Personnel and Financial Resources Available . 108
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CONTENTS (continued)
G. Effects of Discharge on Other Point and Nonpoint Sources 108
1. Additional Treatment or Control Requirements for Other
Point or Nonpoint Sources 108
2. Determination Required by 40 CFR 125.64(b) :. . 109
H. Toxics Control Program 109
1. Industrial Sources of Toxic Pollutants or Pesticides 109
2. Related Water Quality, Sediment Accumulation, or
Biological Problems 112
3. Public Education Program to Minimize Entrance of
Nonindustrial Toxic Pollutants and Pesticides 113
4. Industrial Pretreatment Program 114
5. Urban Area Pretreatment Requirement 115
DETERMINATIONS OF COMPLIANCE WITH SECTION 301(h) MODIFIED
PERMIT CONDITIONS AND 301(h) CRITERIA 123
PERMIT CONDITIONS [ 123
DETERMINATIONS OF COMPLIANCE WITH SECTION 301(h) CRITERIA . . 125
EVALUATIONS OF PREDICTED CONDITIONS AND PREDICTED
CONTINUED COMPLIANCE 131
REFERENCES 134
APPENDICES
APPENDIX A: PHYSICAL ASSESSMENT A-l
APPENDIX B: WATER QUALITY ASSESSMENT B-l
APPENDIX C: BIOLOGICAL ASSESSMENT C-l
APPENDIX D: NAVIGATIONAL REQUIREMENTS AND METHODS D-l
APPENDIX E: TOXIC CONTROL REQUIREMENTS E-l
APPENDIX F: WATER QUALITY-BASED TOXICS CONTROL F-l
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FIGURES
Number
1
2
3
Wastefield generated by a simple ocean outfall 53
Diffuser types and corresponding ZID configurations 57
Generalized depiction of changes in species numbers, total j .
abundances, and total biomass along a gradient of organic !
enrichment 130
TABLES
Number
1
2
3
Estimated pH values after initial dilution . .63
List of pesticides and toxic pollutants as defined
in sections 125.58(aa) and (p) 59
Summary of U.S. EPA marine water quality criteria 71
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PREFACE
The following is the amended technical support document for the Clean Water Act section
301(h) program. This document completely supersedes and replaces the earlier Revised Section
301 (h) Technical Support Document and was made available in draft form for comment on
January 24, 1991 (56 FR 2814).
This Amended Section 301(h) Technical Support Document (TSD) provides municipal
dischargers with technical guidance on preparing applications for section 301 (h) modified permits
and evaluating the effects of 301 (h) discharges on water quality. One of the primary purposes
for amending the TSD is to add guidance concerning revisions to EPA's section 301(h)
regulations (40 CFR Part 125, Subpart G) that the Agency promulgated on August 23, 1994 (59
FR 40642 August 9, 1994). EPA revised the section 301(h) regulations primarily to implement
new section 301(h) requirements imposed by the Water Quality Act of 1987.
The guidance provided in this TSD is a general statement of policy. It does not establish
or affect legal rights or obligations. It does not establish a binding norm and is not finally
determinative of the issues addressed. Agency decisions in any particular case will be made by
applying the law and regulations to the specific facts of the case.
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ACKNOWLEDGMENTS
^ This guidance document was prepared by Tetra Tech, Inc. for the U.S. Environmental
Pro ec ,on Agency under the technical support contracts for marine discharge monitoring
eva,naUons.and technical support for the Office of Marine and Estuarine .Lection dTt!
- -
Cl 0008. Ms^Vu-gmia Fox-Norse was tt,e Work Assignment Manager. Major technical contri-
butors were D, Gordon Bilyard, D, Richard Harris, D, John HochheLr, Dr.
Muellenhofl, Mr. James Pagenkopf, and Dr. A. Mills Soldate ;
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EXECUTIVE SUMMARY
Section 301
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(2) The scope of monitoring investigations is limited to only those investigations
necessary to study the effects of the modified discharge. [§125.63(a)]
'
(3) With respect to any toxic pollutant introduced by an industrial source and for
which there is no applicable pretreatment requirement in effect, POTWs
serving populations of 50,000 or more are required to demonstrate that
industrial 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 in effect a pretreatment program which,
in combination with the POTW's own treatment processes, removes at least
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. [§§125.58(g), 125.580), 125.58(q), 125.58(w), 125.58(aa), 125.65]
(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 §125.58(r)], and that meets applicable water quality
criteria established under section 304(a)(l) of the CWA after initial mixing
in the receiving waters. [§§125.58(r), 125.60, 125.62(a)]
(5) Section 301(h) modified permits may not be issued for discharges into marine
waters that contain significant amounts of previously discharged effluent from
the POTW. [§125.62] !
(6) Section 301(h) modified permits may not be issued for discharges into saline
estuarine 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), 125.59(b)(5)]
j
(7) Any POTW that had an agreement before 31 December 1982 to use an
outfall operated by another POTW 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. [No such
application was filed]
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(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. [§125.590)]
Among the changes listed above, changes 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 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 to consider only whether
their discharge contributed to such impacts.
Change 3 requires applicants serving a population of 50,000 or more to implement
additional' toxics control efforts (urban area pretreatment program). This new statutory
requirement complements the toxics control program requirements in §125.66 and applies in
addition to any applicable pretreatment requirements contained in 40 CFR Part 403. Dischargers
may demonstrate compliance with §125.65 by demonstrating that "an applicable pretreatment
requirement is in effect" for the toxic pollutant or by demonstrating "secondary removal
equivalency."
Applicable pretreatment requirements may be in the form of categorical pretreatment
standards promulgated by EPA under CWA section 307, local limits developed in 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 categorical pretreatment standards and local limits to satisfy
§125.65 with respect to toxic pollutants introduced into the treatment works by industrial sources.
For any toxic pollutant introduced by an industrial source for which there is no categorical
pretreatment standard and it is determined that no local limit is needed, for 301 (h) purposes, an
applicable pretreatment requirement can also be met by the following: annual monitoring and
technical review of industrial discharges, and, where appropriate, implementation of industrial
management practices plans, best management practices, and other pollution prevention activities,
and determination on an annual basis of the need to revise local limits and/or to demonstrate that
there is no need for a local limit for a specific toxic pollutant. When an industrial discharger is
subject to both a categorical standard and a numerical local limit for a specific toxic pollutant,
the more stringent of the two limits applies.
Alternatively, a discharger may 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 is subject to an "applicable
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pretreatment requirement." Although secondary treatment is intended to control conventional
pollutants, a certain amount of toxic pollutants in the influent is removed during the process.
This part of WQA section 303(c) requires that a section 301(h) discharger remove at least that
same amount of a toxic pollutant 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. A secondary
treatment pilot plant could be used to determine empirically the amount of a toxic pollutant that
would be removed from the influent if the applicant were to apply secondary treatment. For each
pollutant introduced by an industrial source, the applicant would then demonstrate that industrial
pretreatment plus the POTW's own treatment processes removed at least the same amount of
pollutant as was removed by the secondary treatment pilot plant. The permit will contain effluent
limits based on data from the secondary equivalency demonstration when these values are more
stringent than effluent limits required to assure all applicable environmental protection criteria
are met. The POTW would then use local limits or perform additional treatment at the POTW,
or combine the two to achieve the permit limit.
I
Change 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, to demonstrate compliance with §125.60. This section (§125.60) requires at least 30
percent removal of both BOD and SS. Section 301(h) dischargers have always been required to
meet state water quality standards that are appropriate for local conditions and that have been
approved by EPA. In addition to the primary or equivalent treatment requirements (§125.60),
§125.62 implements the new WQA requirement that 301 (h) dischargers meet water quality
criteria established under CWA section 304(a)(l) after initial mixing in the receiving waters.
Under the new provision, dischargers must determine whether there is an EPA-approved state
water quality standard that directly corresponds to the CWA section 304(a)(l) water quality
criterion for each specific pollutant. If there is, this directly corresponding state standard would
apply. In the absence of such a state standard, the section 304(a)(l) water quality criterion would
apply. An EPA-approved state water quality standard would be deemed to "directly correspond"
if (1) the state water quality standard addresses the same pollutant as EPA's water quality
criterion and (2) the state water quality standard specifies a numeric criterion for that pollutant,
or an objective methodology for deriving such a pollutant-specific criterion; For example, if a
state 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 §125.62(a).
•
The section 301(h) regulations were not amended with respect to change 5, recirculation
and reentrainment of previously discharged effluent from the POTW. However, POTWs,
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especially those that discharge into receiving waters where reentrainment is likely, need to
address the possible effects of such entrainment when demonstrating compliance with applicable
state water quality standards, water quality criteria, and other section 301(h) criteria. Reentrainm-
ent is most often of concern where tidal currents predominate, and where previously discharged
effluent is likely to be advected into the zone of initial dilution after the tidal currents reverse.
Change 8 in 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 3, 4, and 5 above, but only for the term of that 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.
Under §125.59(e), those applicants that have akeady received tentative or final approvals
(including grandfathered applicants) must submit to the EPA Regional Administrator a letter of
intent to demonstrate compliance with the primary or equivalent treatment requkements (§ 125.60)
by November 7, 1994. Also, applicants serving a population of 50,000 or more must, under
§125.59(e), submit a letter of intent to demonstrate compliance with the urban area pretreatment
requirements (§125.65). Those applicants without tentative approval must submit a letter of
intent to demonstrate compliance with §§125.60 and 125.65 (if applicable) within 90 days of
receiving tentative approval. Applicants that are not grandfathered must, by August 9, 1996,
demonstrate compliance with §§125.60 and 125.65. Those applicants that are grandfathered must
at the time of permit renewal or by August 9, 1996, whichever is later, meet all of the
requirements of §§125.60 and 125.65.
In addition, 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, stressed waters, applications, and applicant questionnaire have
been changed.
New technical guidance given hi this document primarily addresses major changes 1, 3,
4, and 5 above. Hence, it includes the following:
» Guidance for assessing impacts of the applicant's modified discharge "alone
or hi combination with pollutants from other sources";
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• Guidance on methods for demonstrating compliance with urban area
pretreatment requirements;
'• -'-... • '
" Guidance for demonstrating compliance with primary or equivalent treatment;
I
• Guidance for demonstrating compliance with applicable water quality
standards and criteria; and
• 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 (1982), is
also provided for demonstrating compliance with the 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.
General guidance, new guidance, and updated guidance are provided in the format of the
Applicant Questionnaire, with supporting appendices as warranted. General guidance includes
discussions of the types of demonstrations 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 in six supporting
appendices. Methods for calculating initial dilution of the wastefield are provided in Appendix
A (Physical Assessment). Detailed descriptions of analytical methods to demonstrate compliance
with water quality requirements are presented in Appendix B (Water Quality Assessment). These
methods address suspended solids deposition, dissolved oxygen concentrations, sediment oxygen
demand, suspended solids concentrations, effluent pH, light transmittance, and other water quality
variables. Guidance for biological assessments, as represented by benthic community evaluations,
is presented in Appendix C. Navigational considerations for sampling in estuarine and coastal
areas are discussed in Appendix D. The new urban area pretreatment requirements and methods
for demonstrating compliance with them are described in Appendix E. Finally, additional
information on water quality-based toxics control is presented in Appendix F;
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Because of the redundancy that existed between the Small and Large Applicant
Questionnaires in the 1982 regulations, a single Applicant 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 in the section 301(h)
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regulations. In addition to providing technical guidance for responding to questions in the
Applicant 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 EPA Region. Having reached a decision regarding an application
for issuance of a section 301(h) modified permit, the Region may issue or reissue the section
301 (h) modified permit with the same or different permit conditions or may deny the section
301 (h) modification. In the case of denial, the NPDES permit would then be reissued by EPA
(or, in NPDES-delegated states, by the state) with secondary treatment requirements. This
document provides guidance on procedures for reapplying for section 301(h) modified permits.
However, it does not provide guidance on the preparation of NPDES permits, which has been
published in the Training Manual for NPDES Permit Writers (U.S. EPA 1986b).
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INTRODUCTION
Section 301(h) of the Clean Water Act (CWA) allows the U.S. Environmental Protection
Agency (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 EPA may issue
a 301 (h) modified permit if the POTW can demonstrate compliance with section 301 (h) criteria
and all other NPDES permit requirements. The statuatory deadline for 301 (h) applications was
December 29, 1982. EPA issued regulations and a technical support document (TSD) in 1979.
'
Section 301(h) was amended in 1981 by the Municipal Wastewater Treatment
Construction Grants Amendments. In 1982, revised regulations and the Revised Section 301(h)
Technical Support Document (U.S. EPA 1982c) were issued. The revised TSD identified the new
regulatory requirements of section 301(h) and provided technical guidance on the preparation of
section 301 (h) applications. A companion document, Design of 301 (h) Monitoring Programs for
Municipal Wastewater Discharges to Marine Waters (U.S. EPA 1982a), was also issued in 1982.
It provided guidance on the development and implementation 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 technical support document is to identify
changes to the regulations promulgated by EPA to implement new section 301 (h) conditions
resulting from 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 section 301(h) regulatory requirements and
general considerations for applicants in preparing section 301 (h) applications.
This document supersedes 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 Wastewater Discharges to Marine Waters remains relevant to the 301(h)
program, although much additional technical guidance is now available (see Question III.F.1
below). These more recent guidance documents provide updated guidance on the collection,
analysis, and interpretation of monitoring data, including references for updated laboratory and
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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 is divided into two major
sections: a main body of text and six appendices. The main body of text reviews the regulations
implementing section 301(h) (i.e., Code of Federal Regulations, Title 40, Part 125, Subpart G,
59 FR 40642, August 9, 1994)* and highlights changes to those regulations made by EPA to
reflect the amendments 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
reissuance, including general discussions of the types of demonstrations that should be included
by applicants when responding to each question in the Applicant Questionnaire. For example,
it specifies whether large or small dischargers should respond to a given question and discusses
the level of detail that is appropriate for each. Guidance on general considerations for
dischargers in preparing section 301(h) applications is also discussed. The appendices contain
detailed technical explanations of the analytical methods that may be used to demonstrate
compliance with specific regulatory criteria (e.g., formulas to determine dissolved oxygen
concentration following initial dilution and detailed discussions of methods to demonstrate
compliance with urban area pretreatment requirements).
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 in
§125.58(c) as POTWs that "have contributing populations equal to or more 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" [§125.58(c)]. The definition 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 daily total discharge flows for the maximum
month of the dry weather season."
* hereinafter referred to as 40 CFR Part 125, Subpart G.
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BACKGROUND
Clean Water Act section 301 (h) was amended by WQA section 303, entitled "Discharges
into Marine Waters." Section 303 includes sections 303(a) through 303(g). The section 301(h)
regulations have been changed in 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 is summarized below, followed by a brief description of the
corresponding changes in the section 301(h) regulations. Citations to the 40 CFR Part 125,
Subpart G, regulations that appear in the discussion below refer to the section numbers of the
regulations as renumbered. (The 1994 regulations added requirements and are therefore
numbered differently from the 1982 regulations.)
Section 303(a) amends subsection 301(h)(2) to state that the modified discharge "will not
interfere, alone or in combination with pollutants from other sources, with title attainment or
maintenance of water quality which assures protection of public water supplies and the protection
and propagation of a balanced indigenous population of shellfish, fish and wildlife, and allows
.recreational activities, in and on the water" (emphasis added). In response to WQA section
303(a), language was added to §125.62(f) to clarify that it is not sufficient to demonstrate that
the applicant's discharge alone will not interfere with the attainment or maintenance of water
quality as specified in the remainder of §125.62. Applicants must also demonstrate compliance
with §125.62 based on the combined effects of the applicant's modified discharge and pollutants
from other sources. This amendment [WQA section 303(a)] strengthens the existing regulatory
requirements of §125.62(f) allowing discharges to stressed waters provided that the discharger
can demonstrate (1) that the inability to achieve compliance with the requirements of §125.62(a)
through (e) is due to perturbations other than its discharge, (2) that its modified discharge will
not contribute to the stressed conditions or further degrade the biota or water quality, and (3) that
its discharge will not retard the recovery of biota or water quality if the level of human
perturbation from other sources decreases.
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 is 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 focused
on the effects of the applicant's discharge, this limitation was added to §125.63 of the regula-
tions. This limitation does not affect the precedent for developing monitoring programs on a
case-by-case basis.
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WQA section 303(c) is applicable only to large dischargers that receive toxic pollutants
from 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 has
in effect a pretreatment program that, in combination with the POTW's own treatment processes,
removes at least the same amount of toxic pollutant as would be removed if the POTW were to
apply secondary treatment and had no pretreatment program for the pollutant. Under this
provision, each such applicant must demonstrate, for each toxic pollutant introduced by an
industrial discharger, either that it has an "applicable pretreatment requirement in effect" or that
it has implemented a program that achieves "secondary removal equivalency." In accordance
with WQA section 303(c), POTWs are required to demonstrate that industrial sources of toxic
pollutants are in compliance with all of thek pretreatment requirements, including local limits,
and that those standards will be enforced in accordance with Code of Federal Regulations, Title
40, Part 403, 46 FR 9439, 28 January 1981.*
To implement WQA section 303(c), §125.65 was added to the regulations, definitions
were added to §125.58, and existing definitions in §125.58 were revised. Section 125.65 requires
that an urban area pretreatment program be implemented by applicable POTWs to demonstrate
that toxic pollutants are being controlled. It also provides alternative approaches for
implementing urban area pretreatment. Definitions that are relevant to the urban area
pretreatment program and that have been revised or added to the 301(h) regulations include
categorical pretreatment standard, industrial discharger or industrial source, pretreatment,
secondary removal equivalency, and water quality criteria.
WQA section 303(d) establishes a minimum of primary treatment (or its equivalent).
Primary or equivalent treatment is defined in subsection 303(d)(2) as "treatment by screening,
sedimentation, and skimming adequate to remove at least 30 percent of the biochemical oxygen
demanding material and of the suspended solids in the treatment works influent, and disinfection,
where appropriate." This section also mandates compliance with federal water quality criteria
(U.S. EPA 1980, 1985f, 1986a) for section 301(h) dischargers.
To implement WQA section 303(d), §125.60, which requires 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 at §125.58(r).
hereinafter referred to as 40 CFR Part 403.
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Primary or equivalent treatment requires removal of both 30 percent of biochemical oxygen
demand (BOD) and 30 percent of suspended solids (SS) [§125.58(r)].
i
Section 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 section 304(a)(l) of the CWA where
no directly corresponding numerical water quality standards exist. Hence, in addition to
demonstrating compliance with water quality standards [already required under the 1982 section
301(h) regulations], applicants will need to 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." Reentrainment of previously
discharged effluent is often a potential problem in receiving waters that exhibit poor flushing
characteristics, such as semi-enclosed bays or long, narrow estuaries. This section flatly prohibits
issuance of section 301(h) modified permits for discharges into the New York Bight Apex and
further prohibits 301(h) modifications for discharges into saline estuarine 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; and
• 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) modified permit for discharges into saline estuarine waters may not be issued
if any one of the foregoing conditions is not met, regardless of whether the applicant's discharge
contributes to departures from or retards recovery of such conditions.
Section 125.62(a)(l) of the 1982 regulations required the applicant's diffuse! 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 § 125.62(a) was viewed to be a sufficient regulatory criterion
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for ensuring that "significant amounts" of previously discharged effluent are not entrained, this
subsection was not modified in response to WQA section 303(e). (However, additional technical
guidance is provided herein on how to position monitoring stations to determine compliance with
this provision of the WQA.) Section 125.59(b)(4) was modified to include the prohibition of
section 301(h) modified discharges into stressed saline estuarine waters, and §125.62(f) was
modified so that §125.62(f)(l)-(3) ("stressed water test") applies only to ocean waters, as defined.
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 in 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, §125.59© 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 requirement was also added to §125.59(e) and
(f) 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 §125.60 (primary or equivalent
treatment requirements) and §125,65 (urban area pretreatment requirements) within 2 years (non-
grandfathered) or upon permit renewal, whichever is later (grandfathered).
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 regulations apply only to POTWs presently in the
301(h) program. POTWs currently in the program include those presently holding section 301(h)
modified permits and those awaiting a final decision from 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:
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H Explains WQA sections 303(a) through 303(g), and resulting changes in the
section 301(h) regulations (provided above, in the section entitled
"Background," and below, in the section entitled "Statutory Criteria and
Regulatory Requirements");
• ' ' ••
• Provides technical guidance for implementing the new regulations and
updates that for existing regulations (provided below, in the chapter entitled
"Demonstrations of Compliance by Permittees");
• i
I
I
" Provides technical guidance on preparing applications for reissiuance of
section 301(h) modified permits (provided below, in the chapter entitled
"Demonstrations of Compliance by Permittees"); and
• Provides additional technical guidance on preparing applications to
demonstrate compliance with the regulations and on the issuance and
reissuance of section 301 (h) modified permits [provided below, in the chapter
entitled "Determinations of Compliance with Section 301(h) Modified Permit
Conditions and 301 (h) Criteria"].
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:
Guidance for assessing impacts of the applicant's modified discharge "alone
or hi combination with pollutants from other sources";
I
Guidance for demonstrating compliance with at least primary or equivalent
treatment;
Guidance on methods for demonstrating compliance with urban area
pretreatment requirements;
Guidance for demonstrating compliance with applicable water quality
standards and criteria; and
Guidance for demonstrating that dilution water does not contain significant
amounts of previously discharged effluent.
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This guidance appears in the chapter entitled "Demonstrations of Compliance by Permittees"
below and, in some cases, the appendices. Updated guidance is 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,
and the degree of recirculation in the presence of contaminated receiving waters.
Monitoring data collected during the term of the 301 (h) modified permit are submitted
to the regional jurisdiction of the U.S. EPA (hereinafter referred to as Regions) in 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.
NPDES permits are issued for 5-year 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 reissuance of their section 301 (h) modification,
as stipulated in §§125.59, 122.21(d),* and 124.3.1" In the future, EPA will consider only section
301(h) applications submitted by the deadline (29 December 1982) on which there has not yet
been a decision and those applications for reissuance.
According to §125.59(c), "applicants for permit renewal shall support continuation of the
modification by supplying to EPA the results of studies and monitoring performed in accordance
with §125.63 during the life of the permit." However, neither this section nor other parts of 40
CFR Part 125, Subpart G, provide specific guidance on how the results of studies and monitoring
should be used to support the application for permit reissuance. This amended TSD with its
appendices generally provides technical guidance to show how to use these results (see the
chapter entitled "Determinations of Compliance with Section 301(h) Modified Permit Conditions
and 301(h) Criteria").
In the 1982 section 301(h) regulations, 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
* Found in Code of Federal Regulations, Tide 40, Part 122, 48 FR 14153, 1 April 1983 (hereinafter referred
to as 40 CFR Part 122).
1 Found in Code of Federal Regulations, Title 40, Part 124, 48 FR 14264, 1 April 1983 (hereinafter referred
to as 40 CFR Part 124).
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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 most small appli-
cants in their responses is considerably less than that required of large applicants in their
responses to the same questions. 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 may be required of
j
small and large applicants during the permit reissuance process.
I
This document provides considerations for assessing compliance with section 301(h)
regulations. Appropriate uses of monitoring data to assess 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.
I
Having reached a decision regarding an application for reissuance 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 may deny the section 301(h) modification. In the case of denial,
the NPDES permit would then be reissued by EPA (or, in NPDES-delegated states, by the state)
with secondary treatment requirements. This document provides guidance on procedures for
reapplying for section 301(h) modified permits. However, it does not provide guidance on the
preparation of NPDES permits, which has been published elsewhere (see U.S. EPA, 1986b).
STATUTORY CRITERIA AND REGULATORY REQUIREMENTS
I
The WQA of 1987 amended CWA section 301(h) in eight respects. Each of these is
summarized below, followed by references to key sections 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
section 301(h)(2) (i.e., assures protection of public water supplies and the
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protection and propagation of a balanced, indigenous population of shellfish,
fish, and wildlife, and allows recreational activities in and on the water).
(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. [§125.63(a)]
(3) With respect to any toxic pollutant introduced by an industrial source and for
which there is no applicable pretreatment requirement hi effect, POTWs
serving populations of 50,000 or more are required to demonstrate that
industrial 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 in effect a pretreatment program which,
hi combination with the POTW's own treatment processes, removes at least
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. [§§125.58(g), 125.58(j), 125.58(q), 125.58(w), 125.58(aa), 125.65]
(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 §125.58(r)], and that meets the water quality criteria
established under section 304(a)(l) of the CWA after initial mixing in the
receiving waters. [§§125.58(r), 125.60, 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
POTW. [§125.62]
(6) Section 301(h) modified permits may not be issued for discharges into saline
estuarine 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), 125.59(b)(5)]
(7) Any POTW that had an agreement before 31 December 1982 to use an
outfall operated by another POTW that had applied for or received a section
301 (h) modified permit could have applied for its own section 301(h)
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modified permit within 30 days of enactment of the WQA. [ [No such
application was filed.] ;
(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(j)]
i
Among the changes listed above, changes 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 change requires POTWs to
consider the impacts of their discharge on the receiving water and biota in combination with
pollutants from other sources. Previously, POTWs were required to consider only whether their
discharge contributed to such impacts. !
Change 3 requires applicants serving a population of 50,000 or more to implement
additional toxics control efforts (urban area pretreatment program), discusised in detail below
under "Demonstrations of Compliance by Permittees" and in Appendix E. This new statutory
requirement complements the toxics control program requkements in §125.66 and applies in
addition to any applicable pretreatment requirements contained in 40 CFR Part 403. Dischargers
may demonstrate compliance with §125.65 by demonstrating that "an applicable pretreatment
requirement is in effect" for the toxic pollutant or by demonstrating "secondary removal
equivalency."
i
Applicable pretreatment requkements may be in the form of categorical pretreatment
standards promulgated by EPA under CWA section 307, local limits developed in accordance
with 40 CFR Part 403, or a combination of both. It is anticipated that most dischargers will be
requked to use a combination of categorical pretreatment standards and local limits to satisfy
§125.65 with respect to toxic pollutants introduced into the treatment works by industrial sources.
For any toxic pollutant introduced by. an industrial source for which there is no categorical
pretreatment standard and it is determined that no local limit is needed, for 301 (h) purposes, an
applicable pretreatment requkement can also be met by the following: annual monitoring and
technical review of industrial discharges, and, where appropriate, implementation of industrial
management practices plans (IMPs), best management practices (BMPs), and other pollution
prevention activities, and determination on an annual basis of the need to revise local limits
and/or to demonstrate that there is no need for a local limit for a specific feme pollutant. When
an industrial discharger is subject to both a categorical standard and a numeric local limit for a
specific toxic pollutant, the more stringent of the two limits applies.
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Alternatively, a discharger may 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 is subject to an "applicable
pretreatment requirement." Although secondary treatment is intended to control conventional
pollutants, a certain amount of toxic pollutants in the influent is removed during the process.
This part of WQA section 303(c) requires that a section 301(h) discharger remove at least 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. A secondary
treatment pilot plant could be used to determine empirically the amount of a toxic pollutant that
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 at least the same amount of
pollutant as was removed by the secondary treatment pilot plant. The pemit will contain effluent
limits based on data from the secondary equivalency demonstration when these values are more
stringent than effluent limits required to ensure all applicable environmental protection criteria
are met. The POTW would then use local limits or perform additional treatment at the POTW,
or combine the two to achieve the permit limit.
Change 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, to demonstrate compliance with §125.60. This section (§125.60) requires at least 30
percent removal of both BOD and SS. Section 301(h) dischargers have always been required to
meet state water quality standards that are appropriate for local conditions and that have been
approved by EPA. In addition to the primary or equivalent treatment requirements (§125.60),
(§125.62) implements the new WQA requirement that 301 (h) dischargers meet water quality
criteria established under CWA section 304(a)(l) after initial mixing in the receiving waters.
Under the new provision, dischargers must determine whether there is an EPA-approved state
water quality standard that directly corresponds to the CWA section 304(a)(l) water quality
criterion for each specific pollutant. If there is, this directly corresponding state standard would
apply. In the absence of such a state standard, the section 304(a)(l) water quality criterion would
apply. An EPA-approved state water quality standard would be deemed to "directly correspond"
if (1) the state water quality standard addresses the same pollutant as EPA's water quality
criterion and (2) the state water quality standard specifies a numeric criterion for that pollutant,
or an objective methodology for deriving such a pollutant-specific criterion. For example, if a
state water quality standard exists only for a group of toxic substances, such as metals, applicants
12
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would also be required to demonstrate compliance with the water quality criteria for individual
metals (e.g., cadmium, lead, zinc) to demonstrate compliance with §125.62(a).
The section 301(h) regulations were not amended with respect to change 5, recirculation
and reentrainment of previously discharged effluent from the POTW. However, POTWs,
especially those that discharge into receiving waters where reentrainment is likely, need to
address the possible effects of such entrainment when demonstrating compliance with applicable
state water quality standards, water quality criteria, and other section 301(h) criteria.
Reentrainment is most often of concern where tidal currents predominate, and where previously
discharged effluent is likely to be advected into the ZID after the tidal currents reverse.
Technical guidance is provided hereunto assist applicants in demonstrating compliance with this
new requirement. . . i
Finally, change 8 in 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 3, 4, and 5 above, but only for the term of that 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.
Under § 125.59(e), those applicants that have already received tentative or final approvals
(including grandfathered applicants) must submit to the EPA Regional Administrator a letter of
intent to demonstrate compliance with the primary or equivalent treatment requirements (§ 125.60)
by November 7, 1994. Also, applicants serving a population of 50,000 or more must, under
§125.59(e), submit a letter of intent to demonstrate compliance with the urban area pretreatment
requkements (§125.65). Those applicants without tentative approval must submit a letter of
intent to demonstrate compliance with §§125.60 and 125.65 (if applicable) within 90 days of
receiving tentative approval. Applicants that are not grandfathered must, by August 9, 1996,
demonstrate compliance with §§125.60 and 125.65. Those applicants that arc grandfathered must
at the time of permit renewal or by August 9, 1996, whichever is later, meet all of the
requirements of §§125.60 and 125.65.
All but one (change 7) of these eight statutory changes have been integrated into the
amended section 301(h) regulations and must be satisfied by all 301(h) applicants, including those
for reissuance of section 301(h) modified permits. Regulations applicable to such applications
include NPDES permit regulations (40 CFR Part 122) and the amended section 301(h) regulations
(40 CFR Part 125, Subpart G). These regulations, including the changes that resulted from the
WQA, are discussed below in detail. As previously noted, this document does not provide
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guidance on the preparation of NPDES permits. Guidance on 40 CFR Part 122 can be found in
U.S. EPA (1986b). For convenience, a portion is briefly discussed below.
40 CFR Part 122. U.S. EPA Administered Programs: The National Pollutant Dischari
Elimination System
Section 122.21 (d). Duty to Reapply-
Under this section, POTWs with an existing 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 information
is 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 §122.41 (h).
It is strongly recommended that POTWs submit their applications for reissuance 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 is 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 applications for completeness and to request any
information needed to complete applications before existing permits expire. Timely submittal
of a completed application is required to qualify for the continuation described below.
Section 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 in those cases, the
previous permit wiU remain fully effective and enforceable, pursuant to the Administrative
Procedure Act.
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40 CFR Part 125. Subpart G
Section 125.56. Scope and Purpose-
40 CFR Part 125, Subpart G, establishes the criteria by which 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.
Section 125.57. Law Governing Issuance of Section 301(h) Modified Permit-
All applicants for section 301(h) modified permits must demonstrate satisfactorily to EPA
that the modified discharge will meet all of the following nine requirements to qualify for a
I
section 301(h) modified permit:
I
(1) An applicant must demonstrate that an applicable water quality standard
exists for each pollutant for which the modification is requested. Details of
this requkement are given in §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 demonstrations that such standards exist.
However, as specified in §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 authorized state or
interstate agency, stating that the modified discharge will comply with state
law. Both the demonstration of compliance with applicable water quality
standards and the state's determination are required of applicants for
reissuance of section 301(h) modified permits. !
I
(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 § 125.62. All are required of applicants for reissuance
of section 301(h) modified permits.
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(3) An applicant must demonstrate that a monitoring program has been
established to monitor the impact of the modified discharge on a representa-
tive sample of aquatic biota. The scope of that monitoring program should
include only those investigations necessary to study the effects of the
modified discharge. General requirements of monitoring program design and
specific requirements of the biological, water quality, and effluent monitoring
components are specified in §125.63. Demonstrating that an effective
monitoring program has been established will be simple for most POTWs
that apply for reissuance of section 301 (h) modified permits because
monitoring data will have been collected over the life of the existing permit.
However, EPA may require an applicant to demonstrate the effectiveness of
an established monitoring program if the quality of the data is suspect, if
incomplete data have been submitted to EPA, or if when the data are
analyzed it is evident that additional data collection is needed to adequately
characterize and detect the effects of the discharge.
(4) An applicant must demonstrate that the modified discharge will not result in
additional requirements on other point or nonpoint sources of pollutants.
Section 125.64 requires an applicant to provide a determination signed by an
authorized state or interstate agency indicating whether the modified
discharge will result in any such additional requirements. The foregoing
demonstration and determination of compliance are required of applicants for
reissuance of section 301 (h) modified permits.
(5) An applicant with a treatment works that serves a population of 50,000 or
more and that receives toxic pollutants introduced into the treatment works
by one or more industrial dischargers must demonstrate that it has an urban
area pretreatment program in effect at the time of final permit approval
(§125.65). This requirement can be met in one of two ways. An applicant
may demonstrate that applicable pretreatment requirements, as defined in
§125.65(c), will be in effect for each toxic pollutant introduced by an
industrial source into the treatment works. Alternatively, an applicant may
demonstrate that it has a program in effect that achieves "secondary removal
equivalency," as defined in §125.58(w) and explained in §125.65(d).
(6) 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 ali toxic
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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 in §§125.65 and
125.66. However, these requirements are waived for small, applicants that
certify that there are no known or suspected sources of toxic pollutants and
pesticides, and that document the certification with an industrial waste survey
as described by 40 CFR 403.8(f). 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 industrM sources of
pollutants before performing the required demonstration or certifying that
there are no known industrial sources of toxic pollutants of pesticides.
(7) An applicant must demonstrate that a schedule of activities has been
established to eliminate the introduction of toxic substances from nonin-
dustrial sources into the treatment works. Just as was required in the original
section 301(h) application, applicants must comply with the specific
requirements of §125.66(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; amd that the
foregoing program may be revised by 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 is required. As was true for the original section
301(h) applications, most small applicants should be able to provide the
foregoing certification. However, the small applicant should review updated
information on water quality, sediment quality, and biological conditions
before certifying that there are no known or suspected water quality, sediment
accumulation, or biological problems that are related to the discharge of toxic
i
pollutants or pesticides. I
' . ' ' ' • I
(8) An applicant must demonstrate that the modified discharge will not result in
new or substantially increased discharges of the pollutant for which a section
301 (h) modification is being requested above the discharge specified in the
l
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section 301(h) modified permit. Details of this requirement are given in
§125.67, which states that where pollutant discharges are attributable, in 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 hi 5-year
increments for the design life of the facility. This demonstration applies to
applicants for reissuance 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 §125.60 and
defined in §125.58(r). An applicant must also meet the criteria established
under CWA section 304(a)(l) in accordance With §125.62(a). Section 301(h)
modified discharges are prohibited into waters that contain "significant
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, do not allow
recreation in or on the waters, or exhibit ambient water quality that does not
meet specified standards. "A significant amount of previously discharged
effluent" is that amount which would cause the discharge plume to violate
water quality standards or water quality criteria beyond the zone of initial
dilution.
Section 125.58. Definitions-
This section defines terms applicable to the 40 CFR Part 125, 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, stressed waters, applications, and applicant questionnaire have been changed.
Section 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 EPA during the application process. As indicated below, some of the general
regulations are not relevant to applications for reissuance of section 301 (h) modified permits.
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According to §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:
I
• Discharges that would not assure compliance with 40 CFR Part: 122 and 40
CFR Part 125, Subpart G; !
I
I
• Discharges of sewage sludge; !
•• r i
n Discharges that would not be in compliance with applicable provisions of
state, local, or other federal laws and Executive orders;
H Applicants that have not met at least primary or equivalent treatment
requirements;
.
'
B Discharges entering saline estuarine waters that are stressed in the manner set
forth in §125.59(b)(4); and
Discharges that enter the New York Bight Apex.
These prohibitions are relevant to applications for reissuance of section 301(h) modified permits.
Section 125.59(c) specifies that all applications for section 301(h) modified permits must
contain a signed, completed NPDES application; a completed Applicant Questionnaire; and a
certification of completeness and accuracy. This provision remains valid for applications for
reissuance 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 Applicant Questionnaire will vary according
to the volume, composition, and characteristics of the discharge, as well as the characteristics of
the receiving water and biota. Applicants should consult with the EPA Region about permit
reissuance well in advance of the application deadline. Timely consultation will.'help ensure that
each applicant is informed of the appropriate level of detail requked to complete the Applicant
Questionnaire and that all data necessary for completing the questionnaire have been collected
and are adequate to demonstrate compliance with 301 (h) criteria and regulations.
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Revisions to original section 3Gl(h) applications that were submitted under the 1979 and
1982 application deadlines are discussed in §125.59(d). Such revisions are not relevant to
applications for reissuance of section 301 (h) modified permits. Also as noted above, a discharger
holding an existing section 301 (h) modified permit must submit an application for a new section
301(h) modified permit at least 180 days before the existing permit expires if the section 301(h)
modification is to be renewed. [See §125.59(f)(l).]
Deadlines for submittal of applications for reissuance of section 301 (h) modified permits
are specified in §122.21(d) and are discussed above. The distribution of such applications is not
specified in 40 CFR Part 124 or 40 CFR Part 125, Subpart G. However, applicants should
adhere to the distribution schedule required for original section 301 (h) applications, as indicated
in §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
in accordance with §§124.53-124.55. Deadlines for applicants desiring to submit revised
applications following the issuance of a tentative decision are stated in §125.59(f)(2).
Under §125.59(e), applicants or permittees are required to submit additional information
regarding their intent to demonstrate compliance with §125.60 (primary or equivalent treatment
requirements) and §125.65 (urban area pretreatment requirements) by November 7, 1994. Section
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 §§125.60 and 125.65 are
specified in §125.59(f)(3).
A favorable state determination is required before the Region reviews an application.
Under §125.59(f)(4), state determinations are due to the Regions no more than 90 days after an
application is submitted to EPA. The Regions may extend this 90-day deadline upon request by
the state. However, extensions may 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.
Under §125.59(g), the Regions may authorize or request an applicant to submit additional
data after the application deadline. Such information must be submitted within 1 year 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 in §125.59(i). All remain relevant to applications for reissuance
of section 301(h) modified permits. For the Administrator to grant a section 301 (h) modified
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permit, an applicant must have demonstrated compliance with §§125.59 through 125.68. State
certification (concurrence) is also required, with the state director cosigning 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 40 CFR Part: 124 and must
contain all applicable terms and conditions specified in 40 CFR Part 122 and §125.68. Appeals
of section 301 (h) determinations may be made in accordance with procedures in 40 CFR Part
124. Under §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 40 CFR Part 125, Subpart G, based on a schedule submitted by the applicant.
Section 125.68. Special Conditions for Section 301(h) Modified Permits-
• i
Section 125.68 sets forth special conditions that must be included in section 301(h)
modified permits, in addition to those specified in 40 CFR 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;
• That schedules of compliance, if needed (e.g., if a permittee had been a small
applicant but became a large applicant and would need to develop a
pretreatment program) be included for the required industrial pretreatment
program [§125.66(c)], the nonindustrial source control program [§125.66(d>],
and control of combined sewer overflows [§125.67].
• That the proposed monitoring program include provisions for monitoring
biota [§125.63(b)], water quality [§125.63(c>], and effluent [§§125.60(b) and
125.63(d)]; and
I
• 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 1994 amendments to 40 CFR Part 125, Subpart G, have been integrated into the
section 301(h) Applicant Questionnaire, which must be completed and included with all
applications for renewal of section 301(h) modified permits. Explanations of the demonstrations
that are required of applicants are given below following each question, and in 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, §125.59 establishes special
procedures and deadlines for demonstrating compliance with §125.60 (i.e., primary or equivalent
treatment requirements) and §125.65 (i.e., urban area pretreatment requirements). Compliance
with §125.62(a)(l) (i.e., water quality standards and criteria, as applicable) is not included in the
special procedures and deadlines established under §125.59.
Under §125.59(e), applicants for new or reissued section 301 (h) modified permits must
submit a letter of intent to demonstrate compliance with §§125.60 and 125.65. For compliance
with §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 §125.60). For
compliance with §125.65, 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 Applicant Questionnaire as needed to ensure that the information in their
application is complete and correct, must obtain new state determinations as specified in
§§125.61(b)(2) and 125.64(b), and must provide the certification required under §122.22(d).
Section 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 §125.59(e)(l). This letter must be submitted by November 7, 1994. 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 §125.590) must demonstrate compliance with §§125.60 and 125.65 by August 9, 1996.
Applicants grandfathered under the aforementioned subsection must demonstrate compliance with
these subsections at the time of permit renewal or by August 9, 1996, whichever is later.
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APPLICATION FORMAT
As specified in §125.59(c), a full, completed application for a section 301(h) modified
permit contains a certification of completeness and accuracy; a signed, completed NPDES
application [Short Form A or Standard Form A in accordance with §§122.21(d) and 124.3]; and
a completed Applicant Questionnaire. The order in which these parts are to be assembled is not
specified in the 301 (h) regulations.
To facilitate review by the Region and appropriate state agencies, it is recommended that
the application be assembled in the following sequence:
• A cover letter signed by the responsible official for the POTW;
i
• The statement of completeness and accuracy mandated in § 122.22(d), signed
by the responsible official for the POTW [§125.59(c)(3)];
A table of contents for the application, including any appendices;
A list of figures for the application;
A list of tables for the application;
• A signed, completed NPDES application Short Form A or Standard
A completed Applicant Questionnaire; and
Foim A;
• Any accessory documents (e.g., technical reports) considered necessaiy for
an independent review of the application.
The Applicant Questionnaire given as Appendix A of 40 CFR Part 125, Subpart G, is
designed to provide EPA with all information necessary to determine whether an. applicant meets
the statutory criteria and regulations of 40 CFR Part 125, Subpart G. Guidance provided in this
document and in Design of 301 (h) Monitoring Programs for Municipal Wastewater Discharges
to Marine Waters (U.S. EPA 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 submittals.
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Applicants/permittees should consult with the appropriate EPA Region in a timely manner
so the Region can assist in determining the level of response needed. This will help the permittee
to submit the appropriate information on time. EPA encourages applicants to work closely with
the Region, particularly during the end of the existing permit term. This will help to ensure that
all data necessary for completion of the Applicant Questionnaire are available well in advance
of the application deadline, and that the 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.
REQUIRED DATA
Applicants "shall support continuation of the modification by supplying to EPA the results
of studies and monitoring performed in accordance with §125.63 during the life of the permit"
[§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 Applicant Questionnaire. Additional
relevant data may be found in publications and technical reports produced by other agencies,
institutions, and companies working in nearby areas of the receiving waters. 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 Applicant Questionnaire.
Although the Regions may be of assistance in clarifying the appropriate application
requirements, it is the permittee's responsibility to contact the Region 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 is 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 §§122.41(h)
and 125.59(f).
INTEGRATION OF DATA WITH EPA DATABASES
Many EPA databases are available for the storage, retrieval, and analysis of water quality,
sediment, and biological sampling data. Although the use of these systems is not mandated by
24
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current legislation, they are useful tools for both the regulated community and the various federal,
state, and regional regulatory authorities. EPA is modernizing its water information systems,
which include ODES (Ocean Data Evaluation System), STORET (Water Quality Information
System), and BIOS (Biological Information System). The systems are used extensively because
of their unique functionality: to manage and analyze water quality and biological monitoring
data. The major objective of the modernization program is to move ODES, STORET, and BIOS
into a relational database environment, facilitating data integration and sharing while
accommodating emerging informational needs. Applicants for 301(h) peirmil: waivers are
encouraged to use these systems for storing and analyzing data required for the application, as
well as for ongoing monitoring programs.
PREPARATION OF THE APPLICANT QUESTIONNAIRE FOR MODIFICATION OF
SECONDARY TREATMENT REQUIREMENTS
/. INTRODUCTION
l
i ( ' '
The Applicant Questionnaire is to be submitted by both small and large applicants for
modification of secondary treatment requirements under CWA section 301(h). A small applicant
is defined as a POTW that has a population contributing to its wastewater treatment facility of
less than 50,000 and a projected average dry-weather flow of less than 5.0 MOD (0.22 cubic
meters/sec) [§125.58(c)]. A large applicant is defined as a POTW that has a population
contributing to its wastewater treatment facility of at least 50,000 or a projected average dry-
weather flow of its discharge of at least 5.0 MOD [§125.58(c)]. The questionnaire is in two
sections, a general information and basic requirements section (Part II) and a technical evaluation
section (Part III). Satisfactory completion by small and large dischargers of the appropriate
questions is necessary to enable EPA to determine whether the applicant's modified discharge
meets the criteria of section 301 (h) and EPA regulations (40 CFR Part 125, Subpart G).
Most small applicants should be able to complete the questionnaire using available
information; However, small POTWs having low initial dilution, discharging into shallow waters
or waters with poor dispersion and transport characteristics, discharging nesir distinctive and
susceptible biological habitats, or discharging substantial quantities of toxics should anticipate
the need to collect additional information and/or conduct additional analyses to demonstrate
compliance with section 301(h) criteria. If there are questions in this regard, applicants should
contact the appropriate EPA Regional. Office for guidance. |
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Guidance for preparing a complete application for reissuance of a section 30l(h) modified
permit is provided below. Special instructions and exceptions for small applicants are also
provided. The sequence in which the application parts are discussed corresponds to that
recommended in the "Application Format" section of this document. Accessory doucments (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
reissuance of section 301 (h) modified permits should consider monitoring data collected over the
term of the existing modified permit, as required under §125.59(c)(4). When monitoring data
and other information, collected over the term of the existing permit, confirm that all the values
used in analyses provided hi the original application have not changed and are not expected to
change over the term of the new modified permit, the applicant may summarize the available data
and provide evidence demonstrating the basis for determining that no change in information has
been realized or expected. In cases where the values of one or more parameters have changed,
however, or where new monitoring data are useful for supporting a given demonstration, those
data should be included in the requked response.
Under section 301(h)(2) and §§125.57(a)(2) and 125.62(f), all demonstrations of
compliance with applicable statutes and regulations must consider the effects of the discharge
singly and hi combination with pollutants from other sources, if any other sources exist. When
demonstrating such compliance, the level of detail requked of small applicants is considerably
less than that requked of large applicants for the same demonstration. Applicants should consult
with the appropriate EPA Region before submitting an application to determine the level of detail
that is appropriate for thek discharge. POTWs that have been classified as small dischargers, but
that no longer meet the conditions of the definition of small discharger [§125.58(c)] or that are
not expected to meet those small discharger conditions during the next permit term, must apply
for reissuance of this section 301 (h) modified permit as large dischargers.
//. GENERAL INFORMATION AND BASIC DATA REQUIREMENTS
ILA. Treatment System Description
II.A.L On which of the following are you basing your application: a current
discharge, improved discharge, or altered discharge, as defined in 40 CFR
125.58? [40 CFR 125.59(a)]
*** Large and small dischargers must respond.
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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 reapplication. Use of the
latest 12 months of data would be most appropriate in the application.
An "unproved 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; or
i •
• Measures to control the introduction of pollutants into the treatment works.
i
.
For improved discharges, applicants should briefly describe the changes to the treatment system
or its operation on which the application is based.
i
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 characteristics, regardless of whether the outfall was previously
improved or relocated to compensate for lower effluent quality, are considered altered discharges.
An applicant that proposes downgrading treatment levels and/or changes outfall and diffuser
location and design must justify the proposal on the basis of substantial changes in circumstances
beyond the applicant's control since the time of application submission and must comply with
applicable state antidegradation policy. Applicants that propose altered discharges based on
changed circumstances and that propose improvements in treatment levels must comply with the
applicable state's antidegradation policy and should briefly describe the changes to the treatment
system or its operation on which the application is based.
ILA.2. Description of the Treatment/Outfall System [40 CFK. 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 40 CFR Part 125, Subpart G. What is the total
discharge design flow upon which this application is based?
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b. Provide a map showing the geographic location of the proposed outfall(s)
(Le., 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 hi sufficient detail to allow evaluation of the technical
merit of the application. 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 diffuser
dimensions used to determine the port flow distribution achieved by the outfall is especially
important (see Question II.A.8 below) and should be specified as accurately as possible. Figures
and drawings with dimensions should be included if 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 diffuser, referenced to mean sea level or mean
lower low water. Water depths and navigational coordinates found in engineering design
documents are often incorrect 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 [40 CFR 125.60]
a. Provide data to demonstrate that your effluent meets at least primary or
equivalent treatment requirements as defined in 40 CFR 125.58 (r). [40
CFR 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, construction, start-up and full operation, with
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* your application. This requirement must be met by the effective data of
the new section 301(h) modified permit.
*** Large and small dischargers must respond.
Applicants must demonstrate that the treatment works will discharge, at a minimum,
primary treated effluent (or its equivalent) at the time their modification becomes effective, as
mandated by §§125.57 and 125.60. Applicants are advised that "primary or equivalent treatment"
is defined in §125.58(r) as "treatment by screening, sedimentation, and skimming adequate to
remove at least 30 percent of the biochemical oxygen demanding material and of the suspended
solids in the treatment works influent, and disinfection, where appropriate." To support this
demonstration, the applicant should supply monthly averaged data for influent aind effluent BOD,
suspended solids, and flow for the last 1-year period. The averaging period (e.g., weekly) for
such data should be specified precisely for each parameter.
EPA believes that the monthly period for averaging monitoring results to determine
compliance with the ,30 percent BOD removal requirement will be appropriate for most
applicants. However, as noted in the preamble discussion of primary treatment in the 1994
regulations, EPA also recognizes that the 30 percent removal rate for BOD may be difficult to
achieve on a monthly average basis in certain cases, e.g., where there is dilute wastewater or
proportionately low concentrations of insoluble BQD, Because of this, §125.60(c) provides
flexibility in achieving 30 percent removal of BOD, in certain instances, by allowing compliance
monitoring data to be averaged for a period longer than monthly, up to annually.
• . • ' • i •
EPA anticipates that compliance, requirements established for loriger-than-monthly
averaging periods for BOD, removal will be the exception, not the general practice. An applicant
that has demonstrated a consistent ability to achieve 30 percent removal of BOD on a monthly
average basis over the year preceding the promulgation of these regulations (or another time
period established by the Regional Administrator when this time period is not applicable) will
not be eligible for the longer-than-monthly averaging period. Eligibility for the longer period is
limited to those POTWs that, based on circumstances listed below, and subject to the
qualifications listed below, truly cannot achieve 30 percent removal on a monthly average.
Eligibility for longer-than-monthly averaging periods will be determined by the Regional
Administrator on a case-by case basis. The Regional Administrator will judge each eligible case,
taking into account climatic, seasonal, or other factors causing significant fluctuations in influent
characteristics that could affect BOD removal efficiencies. Appropriate circumstances may
include:
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• Seasonally dilute influent BOD concentrations due to relatively high
(although nonexcessive) inflow and infiltration;
• Relatively high soluble-to-insoluble BOD ratios on a fluctuating basis; or
• Cold climates resulting in cold influent.
The longer period must be requested by the applicant, and the burden of justifying a
longer averaging period will be on the applicant. In addition to justifying the application on the
basis of the conditions listed above, to qualify for the longer averaging period the applicant must
demonstrate to the satisfaction of the Regional Administrator that the treatment facility is
properly designed and operated; that the applicant wih1 be able to meet all section 301(h)
requirements with the longer averaging basis; and, because of circumstances beyond the
applicant's control (listed above), the applicant cannot achieve the 30 percent removal
requirement for BOD on a monthly averaging basis. Section 125.60(c)(2) of the new regulations
also requires that inflow and infiltration (I&I) be nonexcessive to ensure that applicants have
corrected, as feasible, deficiencies in their collection system that result in extremely dilute
wastewater. The determination of whether the I&I is excessive will be based on the definition
of excessive I&I in 40 CFR 35.2005(b)(16),* plus the additional criterion that inflow is
nonexcessive if the total flow to the primary treatment plant is less than 275 gallons per capita
per day, consistent with 40 CFR 133.103(d)f of the secondary treatment regulations.
If the applicant has received the Regional Administrator's approval to demonstrate
compliance with the 30 percent BOD removal requirement on other than a monthly average basis
[§125.60(c)(l)], monitoring data for determining compliance based on the approved compliance
period should be submitted. The Regional Administrator has discretion to establish averaging
periods up to yearly (e.g., quarterly or semi-annually).
The applicant must maintain the sampling and reporting frequencies for all parameters,
as specified in its permit (e.g., weekly averages, monthly averages). The modified time period
used to calculate compliance with the 30 percent removal requirements applies only to BOD, not
to other measured parameters. For BOD, the goal for whichever averaging period is approved,
As found in Code of Federal Regulations, Title 40, Part 35, 47 FR 44954, 12 October 1982 (hereinafter
referred to as 40 CFR Part 35).
f As found in Code of Federal Regulations Title 40, Part 133, 49 FR 37006, 20 September 1984 (hereinafter
referred to as 40 CFR Part 133).
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up to annually, is to achieve at least 30 percent removal. If the problem is seasonal, a separate
averaging period can be established for that season. However, the POTW will still need to
achieve a 30 percent removal rate for that period. This type of averaging period may require
bracketing the season with monthly average removals greater than 30 percent to achieve the
seasonal 30 percent removal rate. The Regional Administrator may require 30 percent removal
on a monthly average basis for other times of the year.
i
In the event the averaging period is lengthened to a year, the permit may be written to
provide for timely and effective enforcement of the specified 30 percent removal of BOD and
suspended solids and, at the discretion of the permit writer, set interim monthly minimums.
These monthly minimums would be set on a case-by-case basis so that compliance with the 30
percent removal on the basis of an alternative averaging period would be maintained. Historical
performance levels pertaining to the percent removal of BOD and suspended solids and seasonal
fluctuations from month to month, accounting for changes in I&I, could be a factor in
determining the minimum levels. This information could also help to ensure that POTWs
maintain or surpass their historical operating performance. These minimum valu.es, based on past
removal performance, could be set as high as practicable for the applicant to maintain operating
efficiency, which depends on the particular situation and conditions. In addition, permits would
still incorporate daily, 7-day average, and monthly average concentrations, as well as mass
emission rate (MER)-based limits according to the limits on BOD and suspended solids proposed
in waiver applications.
Additional provisions address the primary treatment compliance time frame
[§125.59(f)(3)]. Under §125.59(f)(3), by August 9, 1996 applicants that are riot grandfathered
have to comply and applicants that are grandfathered have until permit renewal or by August 9,
1996, whichever is later, to comply with the primary treatment requirements. This 2-year time
period is designed to allow 1 year for plant construction and another year to demonstrate
compliance with the primary treatment requirements. If approved by the Regional Administrator,
compliance demonstration may be based on less than 1 year's worth of data.. The period to
determine compliance may be less than 1 year if there are sufficient data to determine
compliance, the plant is well designed and there are no operational or maintenance problems, and
the applicant has been complying with the 30 percent removal rate for at least 3 months.
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II.A.4. Effluent Limitations and Characteristics [40 CFR 125.61(b) and
125.62(e)(2)]
a. Identify the final effluent limitations for five-day biochemical oxygen
demand (BODS), suspended solids, and pH upon which your application
for a modification is based:
- BOD5 mg/L
- Suspended solids mg/L
- pH (range)
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 (m3/sec):
- minimum
- average dry weather
- average wet weather
- maximum
- annual average
BODS (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 toxic pollutant and pesticide
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- list each 304(a)(l) criteria and toxic pollutant and pesticides
pH:
- minimum
- maximum
Dissolved oxygen (mg/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)
i
*** 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 is 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 [40 CFR 125.62(e)(2) and 125.67]
a. Provide detailed analyses showing projections of effluent volume (annual
average, ms/sec) and mass loadings (mt/yr) of BODs and suspended solids
for the design life of your treatment facility in five-year increments. If the
application is based upon an improved or altered discharge,, the projections
must be provided with and without the proposed improvements or
alterations.
i • •' ' ' •
b. Provide projections for the end of your five-year permit term for 1) the
treatment facility contributing population and 2) the average daily total
discharge flow for the maximum month of the dry weather season.
\
*** Large and small dischargers must respond. \
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Applicants should project effluent flows and mass emissions for the term of the modified
permit being requested, and for subsequent years at 5-year intervals. Projections should be based
on the 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 daily flow for the maximum month
of the dry-weather season and the average effluent characteristics for that month.
ILA.6. Average Daily Industrial Flow (m3/sec). Provide or estimate the average
daily industrial inflow to your treatment facility for the same time increments as
in question II.A.5 above. [40 CFR 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.
II.A. 7. Combined Sewer Overflows [40 CFR 125.67(b)]
a. Does (will) your treatment and collection 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 BOD5 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 plan, including a narrative description and
implementation schedule for minimizing the discharge of combined sewer overflows to the
receiving water.
34
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**#
ILA.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: [40 CFR 125.62(a)(l)J
Diameter and length of the outfatt(s) (meters)
Diameter and length of the diffuser(s) (meters)
Angle(s) of port orientation(s) from horizontal (degrees)
Port diameter(s) (meters)
Orifice contraction coefficients), if known \
Vertical distance from mean lower low water (or mean tow 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 (m3/sec)
Large and small dischargers must 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 by 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 iraformation on the
slope of the diffuser and the slope of the port centerlines 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) should be provided,
as should any variations in port depths along the length of the diffuser. ;
The information provided in this section is routinely used in the review process to
determine whether the diffuser is well-designed hydraulically for the range of flow (daily
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 poit flow distribution
from a multiport diffuser are described by Grace (1978). Discharge coefficients for risers can
35
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be computed using methods provided by Koh (1973). 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.
ILB.
Receiving Water Description
ILB.l. Are you applying for a modification based on a discharge to the ocean [40
CFR 125.58(n)] or to a saline estuary [40 CFR 125.58(v)J? [40 CFR 125.59(a)J
*** Large and small dischargers must respond.
Ocean waters are defined hi §125.58(n) as coastal waters, other than saline estuarine
waters (defined below), 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 miles outward
from the baseline, and the contiguous zone extends an additional 9 miles.
Saline estuarine waters are defined in §125.58(v) as coastal waters inside the baseline
from which the territorial seas are measured which have a free connection to the territorial sea
in which the salinity is diluted by freshwater inflows, 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 parts per
thousand (ppt). It should be noted, however, that 25 ppt is used as a general test hi §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 requirements of §125.58(v) (i.e., inside the baseline from which
the territorial seas are measured, free connection to the territorial sea in which the salinity is
diluted by freshwater inflows, and net seaward exchange with ocean waters).
Estuarine dischargers are advised that according to §§ 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:
• Support a balanced indigenous population of shellfish, fish, and wildlife;
• Allow for recreational activities hi and on the waters; and
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• Exhibit ambient water quality that meets applicable water quality standards
adopted for the protection of public water supplies, shellfish, fish, and
wildlife, or recreational activities, or such other standards necessaiy to assure
support and protection of such uses.
.
•
These conditions must be met, regardless of whether the applicant's discharge contributes to
departures from such conditions. According to section 301(h) and §125.57(e), the foregoing
prohibition does not apply to discharges with section 301 (h) modified permits that were
tentatively or finally approved prior to the enactment of the Water Quality Act of 1987.
However, 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 estuariine dischargers
must demonstrate that the receiving waters exhibit the above characteristics (i.e., that they are
not stressed) at the time of permit reissuance, regardless of whether such conditions existed at
the time the existing section 301(h) modified permit was issued.
ILB.2. Is your current discharge or modified discharge to stressed waters as
defined in 40 CFR 125.58(z)? If yes, what are the pollution sources contributing
to the stress? [40 CFR 125.59(b)(4) and 125.62(f)J
***
Large and small dischargers must respond.
Stressed wafers are defined in §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. Section 12',5.57(a) prohibits
reissuance of section 301(h) modified permits if the discharge alone or in combination with
pollutants from other sources adversely impacts the balanced indigenous population, water
quality, or recreational activities. In addition, dischargers to estuaries are advised that under
section 301(h)(9) and §§125.57(a)(9) and 125.59(b)(4), permits may not be reissued for
discharges to stressed saline estuarine waters. \
i
i
Guidance for establishing monitoring programs to determine whether receiving waters
should be characterized as stressed waters is found in section III.F of this document. Detailed
guidance on the design of section 301(h) monitoring programs is provided in Design of 301 (h)
Monitoring Programs for Municipal Wastewater Discharges to Marine Water (U.S. EPA 1982a)
and Framework for 301(h) Monitoring Program (U.S. EPA 1987e).
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Sections (a) through (e) of §125.62 address the attainment and maintenance of water
quality, assuring the protection of public water supplies and the protection and propagation of
a balanced indigenous population of shellfish, fish, and wildlife and allowing recreational
activities. In accordance with §125.62(f), stressed waters, if an applicant that discharges into
ocean waters believes that its failure to meet the requirements of §125.62(a) through (e) is
entirely attributable to conditions resulting from human perturbations other than its modified
discharge (including, without limitation, other municipal or industrial dischargers, nonpoint source
runoff, and the applicant's previous discharges), the applicant need not demonstrate compliance
if it demonstrates to the satisfaction of the Administrator that its modified discharge does not or
will not (1) contribute to, increase, or perpetuate stressed conditions; (2) contribute to further
degradation of the biota or water quality if the level of human perturbation from other sources
increases; and/or (3) retard the recovery of the biota or water quality if the level of human
perturbation from other sources decreases.
Applicants that respond "no" to this question should explain the basis for their conclusion.
ILB.3. Provide a description and data on the seasonal circulation patterns in the
vicinity of your current and modified discharge(s). [40 CFR 125.62(a)J
*** Large and small dischargers must respond.
The applicant should provide sufficient information on current speed and direction in 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, as well as the locations of the current meters and the
time span over which data were collected, should also be provided. 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 upwelling 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 U.S. Department of Commerce
tidal current tables (e.g., National Ocean Survey 1988a, 1988b).
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Section 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
reentrainment of previously discharged effluent or the presence of nuisance materials (e.g.,
floatables, scum, oil sheen) in and around the discharge area. Reentrainment 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.
H.B.4. Oceanographic conditions in the vicinity of the current and proposed
modified discharge(s). Provide data on the following: [40 CFR 125.62(a)]
\
- Lowest ten percentile current speed (m/sec)
- Predominant current speed (m/sec) and direction (true)' during the four
seasons
- Period(s) of maximum stratification (months)
- Period(s) of natural upwelling events (duration and frequency, months)
- Density profiles during period(s) of maximum stratification
***
Only large dischargers must respond.
The vertical and areal distribution of currents and water density in both the nearfield and
farfield are needed to evaluate plume dilution, wastefield transport, and potential reentrainment
of previously discharged effluent. Data collected from previous studies or nearby similar areas
will often be appropriate.
The number and location of sampling stations needed to provide sufficient data will
depend on the bathymetric and hydrographic environment. For open coastal sites with uniform
bathymetry and minimal freshwater inflows, as few as five stations may be adequate. For an
estuary with significant freshwater inflow and highly variable bathymetry, -however, as many as
50 stations may be necessary.
i
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
The direction is specified in terms of true north (T).
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obtained near the surface, at the approximate depth of the wastefield, and in the bottom 2 meters
(6.6 feet) 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 tune within which these measurements should be obtained is 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-minute intervals for not less than 29 days. If
seasonal changes in oceanographic conditions (e.g., low or variable longshore current speeds or
directions, upwelling, 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 in the application. The following forms of data reduction
and presentation are recommended:
• 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 hour 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 10 cm/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
predominant flow directions, an axis parallel to the local bathymetry or in the
direction of an area of significance can be selected.
40
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• 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 oceanographic data collection is provided
in Design of 301(h) Monitoring Programs for Municipal Wastewater Discharges to Marine
Waters (U.S. EPA 1982a).
ILB.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? [40 CFR 125.57(a)(9)]
***
Large and small dischargers must respond.
Applicants should explain the basis for their response to this question. Explanations
should consider the hydrographic characteristics of the receiving water 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 carried 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 reenters the ZID. The
demonstration will be much more complicated for dischargers into estuarine 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 ZID on the second half of that cycle. If effluent
is 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 water quality
criteria. Responses given for Questions II.D.l, II.D.2, and ILD.3 of the Applicant Questionnaire
may be cited to support this demonstration.
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H.B.6. Ambient water quality conditions during the period(s) of maximum
stratification: at the zone of initial dilution (ZID) boundary, at other areas of
potential impact, and at control stations. [40 CFR 125.62(a)J
a. Provide profiles (with depth) on the following for the current discharge
location and for the modified 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 light transmittance)
- Other significant variables (e.g., nutrients, 304(a)(l) criteria and toxic
pollutants and pesticides, fecal coliform 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: [40 CFR 125.61(b)(l)]
- Dissolved oxygen (mg/L)
Suspended solids (mg/L)
- pH
Temperature (°C)
Salinity (ppt)
Transparency (turbidity, percent light transmittance)
- Other significant variables (e.g., nutrients, 304(a)(l) criteria and toxic
pollutants and pesticides, fecal coliform bacteria)
c. Are there other periods when receiving water quality conditions may be
more critical than the period(s) of maximum stratification? If so, describe
these and other critical periods and data requested in 6.a. for the other
critical period(s). [40 CFR 125.62(a)(l)]
*** Small dischargers must respond to parts b and c.
*** Large dischargers must respond to parts a and c.
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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 is
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 Celsius) and salinity (expressed in parts per
thousand, ppt) should be measured accurately to two decimal places so that density (expressed
hi grams per cubic centimeter, gm/cm3) 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 height-of-rise (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 is 1 year. Because oceanographic conditions vary among years,
it is recommended that data collected over 5 years be provided. |
Sampling for nutrients, coliform or other indicator bacteria, and other major parameters
may be conducted at selected depths and should be measured in terms that can be compared with
water quality standards. The evaluation of light transmittance may require the measurement of
one or more water clarity parameters and a comparison of values recorded in the vicinity of the
outfall with those recorded in control areas. Parameters that are widely measured to assess light
transmittance include turbidity, Secchi disc depth, beam transmittance, and downward irradiance.
The applicant should review Chapter B-VII in Appendix B for more information on the selection
of sampling methods appropriate for various waterbody conditions (e.g., the presence of
submerged plumes). The applicant should state the reason(s) for the light transmittance
method(s) selected. In addition, because sunlight greatly increases die-off rates of enteric bacteria
(Crane and Moore 1986, Elliot and Colwell 1985), 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 hi Design of 301(h) Monitoring Program for Municipal Wastewater Discharges to
Marine Waters (U.S. EPA 1982a) and summarized below.
i
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 ZED boundary and the upcurrent control
station, and in 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
43
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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 in 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 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 during the day (e.g., high and low slack tides) to aUow evaluation of short-
term conditions. The duration of the longshore current in relation to the time of sampling is 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 current 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, BOD5 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 currents) should be discussed. Current data or other oceanographic
information should be collected (e.g., deploy drogues) at the time of the survey in order 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 frequency and duration of each of these observed conditions should be
provided. Any unusual meteorological, oceanographic, or POTW operating conditions should
also be described. The last three cases represent the potential for recirculation or reentrainment
of previously discharged effluent or the presence of nuisance materials (e.g., floatables, scum,
oil sheen) in and around the discharge area. The degree of recirculation would become
significant if the discharge caused a violation in water quality standards or water quality criteria,
as appropriate, at the ZID boundary, when under normal circulation conditions it would meet the
standards or criteria at the ZID boundary.
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ILB.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.
i '
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 be used to determine oxygen consumption rates. The results of these measurements and the
procedures used should be described.
ILC. Biological Conditions
In the section 301(h) process, the determination of adverse biological effects involves
assessing whether a balanced indigenous population (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 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 in the receiving water body. Similarly, the terms shellfish, fish,
and wildlife should be interpreted to include any and all biological communities that might be
affected adversely by a marine POTW discharge [§125.58(y)].
A BIP is defined in the section 301(h) regulations [§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 in the polluted water body segment from adjacent waters if
sources of pollution were removed." Balanced indigenous populations generally occur hi
unpolluted waters. The second part of the definition concerning the re-establishment of
communities is included because of its relevance to proposed, improved discharges and to
discharges into waters that are stressed by sources of pollution other than the applicant's modified
discharge.
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The biological community characteristics that might be examined hi an evaluation of a
BIP include (but are not limited to) species composition, abundance, biomass, dominance, and
diversity; spatial and temporal distributions; growth and reproduction of populations; disease
frequency; trophic structure and productivity patterns; presence or absence of certain indicator
species; bioaccumulation 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 EPA has determined
that these are observable characteristics of natural communities that exist in the absence of human
disturbance, a comparative strategy is found throughout the section 301(h) regulations. Biological
parameters of concern within and beyond the ZID should be compared to the range of natural
variability found in comparable but unpolluted habitats.
The extent of documentation provided by the applicant in the marine biological
assessment should reflect the quality and quantity of the effluent and the sensitivity of the
receiving water. 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.L Provide a detailed description of representative biological communities
(e.g., plankton, macrobenthos, demersal fish, etc.) in the vicinity of your current
and modified discharge(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 reproduction; 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 on 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 estuarine
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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
associated with decreased abundances of suspension-feeding animals and increased abundances
of deposit-feeding animals. Such effects would be expected to occur in 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 a BIP exists (or will exist) near the existing and modified discharges.
This descriptive information must be used as the basis for the applicant's response to Question
III.D.1. The applicant should design the monitoring program to collect data on biological
conditions and habitat characteristics within and at the ZID-boundary, nearfield, farfield, and
reference sites, ensuring that conditions near the discharge and shoreward are not excluded.
i
Applicants must submit descriptions of representative biological communities (typically
benthic infauna and demersal fishes) in the receiving water body. These descriptions will form
the basis for the comparative BIP demonstrations. It is important that the applicant assess
biological community characteristics at a minimum of four sites: within the ZED, at or immedia-
tely beyond the ZID boundary, within the expected discharge impact area outside the ZED, and
at appropriate reference sites.
i
Benthic data should be adequate to perform valid statistical and community analyses for
the purposes of determining whether the following conditions exist:
i
• Benthic community structure in the discharge area differs from that in 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.
Distinctive habitats of limited distribution (when present) are adversely
affected by the applicant's discharge.
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• The discharge contributes to or perpetuates ambient stresses in the receiving
water (stressed water discharges only).
When the applicant's discharge is located in an area of soft substrates, sediment data
should also be collected simultaneously with the benthic community at each sampling station.
These data should include grain size composition and a measure of organic content. Data on
Kjeldahl nitrogen, sediment BOD5, and other sediment parameters may also be collected.
Sediment data will be used to identify correlations between benthic community structure and
attributes of the sedimentary environment in the receiving waters. Detailed guidance for
evaluating benthic community conditions in the vicinity of an outfall is given in Appendix C.
J/.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? [40
CFR 125.62(c)J
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 environments 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 fauna! (e.g., coral) components of the communities. The potential
for adverse effects of bioaccumulation of toxic substances is also relatively high because sessile
floral and fauna! 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 should describe distinctive habitats of limited distribution within the
receiving water environment, as follows:
• Kinds of distinctive habitats that occur in the general vicinity of the
discharge;
• Area! extent and location of the habitats in the region (shown on a map);
48
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• Approximate distance from the discharge to sensitive habitats;
• Physical characteristics of each distinctive habitat (water column and
substrate);
i
i
• Species composition of the flora and fauna;
I '. 4'
• Abundance or percent cover (as applicable) of resident species; and
• Spatial and temporal variations in the biotic and abiotic components of each
distinctive habitat present. i
i
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. j
i
ILC.3. a. Are commercial or recreational fisheries located in areas potentially
affected by the discharge? [40 CFR 125.62(c) and (d)]
b. If yes, provide information on types, location, and value of fisheries.
***
Large and small dischargers must respond.
Assessment of impacts on fisheries is 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 on regulatory or health-related factors that prevent utilization of the resource,
especially if such factors are related to contamination. Information pertaining to water quality
criteria and the associated human health risk levels is discussed under Question HI.F.1.
Additionally, Question III.F.l discusses the possibilities of adverse effects due to the current
discharge and references the guidance needed to effectively assess the levels of toxic
accumulation in any contaminated organisms. 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).
49
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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.
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) and
Economic value of commercial landings or sport fishery;
» Temporal pattern of the fisheries.
ILD. State and Federal Laws 140 CFR 125.61 and 125.62(a)(l)J
ILD.l. 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 scattering, 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.
ILD.2. If yes, what is the water use classification for your discharge area? What
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.
*** Large and small dischargers must respond.
50
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In response to Question II.D, applicants should demonstrate compliance with state water
quality standards [§125..61(b)]. Individual states often have water quality standards that must be
met independently from federal water quality criteria. State standards that ares applicable to the
discharge must be provided in this response, and determinations of compliance with those
standards must be provided in the response to Questions III.B.6 and III.B.7. Occasionally, state
water quality standards are dependent on the location of the outfall diffuseir. If the effluent
wastefieid is transported to a location having standards different from those of the diffuser
location, then both sets of standards apply [§125.62(a)(l)].
II.D.3. Will the modified discharge: [40 CFR 125.59(b)(3)J \
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 (MPRSA) as amended, 16
U.S.C. 1431 et seq., or in an estuarine 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 MPRSA, 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 may 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
*** Large and small dischargers must respond.
\
Applicants should contact the National Marine Fisheries Service (NMFS), U.S. Fish and
Wildlife Service (USFWS), and applicable state coastal zone management ag;ency for answers
to this question.
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II.D.4. Are you aware of any State or Federal laws or regulations (other than the
Clean Water Act or the three statutes identified in item 3 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^), or order(s). [40 CFR 125.59 (b)(3)J
*** Large and small dischargers must respond.
Because each application for permit reissuance is considered to be an application for a
new NPDES permit, applicants are required to provide new determinations of compliance with
all applicable local, state, and federal laws and regulations, as indicated above.
///. TECHNICAL EVALUATION
III.A. Physical Characteristics of Discharge [40 CFR 125.62(a)l
IILA.1. What is the critical initial dilution for your current and modified
discharge(s) during 1) theperiod(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 is 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
52
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SURFACE
TRAPPING
DEPTH
PYCNOCUNK
REGION
TRANSITION
ZONE
DRIFT FIELD
MERGING
ZONE
RISING
PLUMES
HEIGHT-
OF-RISE
ENTRAPMENT
OF DILUTION ,
WATER
Figure 1. Wastefield generated by a simple ocean outfall.
53
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called the "height-of-rise" (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 (ambient water plus effluent) to the volume
of effluent in the sample. A dilution of 100 is, 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 is 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-hour effluent flow for the new end-of-permit
year and a current speed no higher than the lowest 10 percentile current speed must be used. A
simplified procedure for computing initial dilution is described in Appendix A. Five EPA-
supported computer models (i.e., UPLUME, UOUTPLM, UMERGE, UDKHDEN, ULINE) and
several analytical formulas for computing initial dilution are described by Muellenhoff et al.
(1985a, 1985b). These five models were designed for submerged discharges in oceans. All but
one can be used on rivers, lakes, and estuaries with appropriate input modifications; UPLUME
is restricted to stagnant water environments where ambient water current velocity is zero (e.g.,
lakes, reservoirs). Also available through EPA is CORMIX, an expert system that guides the
user in selecting an appropriate modeling strategy for rivers or estuaries (U.S. EPA 1991b).
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 floppy diskettes that can be read by an IBM-
compatible personal computer. Muellenhoff et al. (1985a) discuss guidelines for use of the
models. >
The method described in Appendix A to calculate initial dilution is most applicable to
situations where ample dilution waters are available. Three assumptions are made when using
the simplified method: (1) the discharge is submerged; (2) the submergence depth of the port is
more than 10 times the diameter of the port; and (3) the hydraulic pressure within the port is
greater than ambient water pressure (i.e., there is a constant flow out of the outfall).
Care should be taken when using this method of calculation in situations where ample
dilution waters are not available. Using these calculations for discharges into shallow waters or
estuarine areas may result in overconservative or invalid results. Additional information for
54
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modeling of estuarine areas can be found in Technical Guidance Manual for Performing Waste
Load Allocations, Book III: Estuaries, Part 3 Use of Mixing Zone Models in Estuarine Waste
Load Allocations (Ambrose et al. 1992). , •
The method presented Appendix A is for use in the absence of site-specific information.
Where site-specific information is available, or where site-specific circumstances, make the
calculation of the initial dilution ratio suspect, the numerical model UPLUME or UMERGE can
be used to provide a better estimate of initial dilution. Case-by-case assessments of the accuracy
of calculations made using the Appendix A method may be necessary in such instances. Site-
specific information on topography, density profile, type of outfall, current measurements,
physical circulation patterns, and temperature is needed to obtain an accurate calculation of initial
dilution. Recalculation with site-specific information using the methods in Mixing in Inland and
Estuarine Waters (Fischer et al. 1979) could be conducted.
I-
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 is
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 stipulation is applicable to UMERGE and UDKHDEN, but not ULINE.)
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.
When monitoring data and other information, collected over the term of the existing
permit, confirm that all the values .used hi analyses provided in the original application have not
changed and are not expected to change over the term of the new modified permit, the applicant
may summarize the available data and provide evidence demonstrating the basis for determining
that no change in information has been realized or expected. In cases where the values of one
or more parameters have changed, however, or where new monitoring da1:a are useful for
supporting a given demonstration, those data should be included hi the required response.
•
•
Under section 301(h)(2) and §§125.57(a)(2) and 125.62(f), 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. Some
applicants will find, however, that monitoring data or other information collected during the term
55
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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.
IILA.2. What are the dimensions of the zone of initial dilution for your modified
discharge(s)?
*** Large and small dischargers must respond.
The zone of initial dilution (ZID) is 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
concentrations more severe than those predicted for critical conditions. The ZID is 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 distance d from any point of the diffuser, where d is 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) and may not be larger than
allowed by mixing zone restrictions in applicable water quality standards [§125.58(dd)].
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 be identical to that presented in the original
application. Repetition of the calculation in the application for reissuance of the section 301(h)
modified permit is necessary to confirm that all values used hi the original application were
correct and that the outfall system has not changed and will not change over the term of the new
permit.
III.A.3. What are the effects of ambient currents and stratification on dispersion
and transport of the discharge plume/wastefield?
*** Only large dischargers must respond.
56
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Y-DIFFUSER
LINEAR DIFFUSER
SINGLE POINT
L-DIFFUSER
Note: d * Water Depth
Figure 2. Diffuser types and corresponding ZID configurations.
57
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A general description of the ambient currents expected within the influence of the diffuser
site is required by EPA. Since this description is 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 reentrainment of
previously discharged effluent, which could effectively increase wastefield concentrations at the
boundary of the ZDD. 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 subpycnocline 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.
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, 1988b) provide tidal current information for a large number of locations. Information
from other published documents is usable if the documents are made available to EPA on request.
Expected or measured effluent dilutions at important shoreline stations should be included.
Chapters B-H, Dissolved Oxygen Concentration Following Initial Dilution, and B-III, Farfield
Dissolved Oxygen Depression, in Appendix B of this document provide further guidance on
computing farfield dilutions for water quality parameters.
Under certain circumstances, such as low nontidal currents or reversing tidal currents, the
affected "ambient" water quality concentrations of the dilution water for the plume may be
temporarily higher than the normal background concentration. Thus, higher concentrations of
pollutants may occur within the ZED. This issue is of primary concern for discharges located in
estuaries or semi-enclosed water bodies but may also be of concern for open coastal 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 coUected during the existing discharge monitoring program. A monitoring
58
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strategy is described below in guidance for questions in 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.
For relocated or proposed new discharges, numerical circulation and toinsport models are
the most useful methods for assessing the effects of ambient currents and stratification on
dispersion and transport of the wastefield and for estimating the potential for recireulation of
previously discharged effluent.. There are two general approaches. The first is to simulate a
conservative substance (i.e., no decay) as a tracer for the wastefield to estimate numerical dilution
factors surrounding the discharge. These dilution factors can be used to estimate the affected
ambient concentration of any water quality parameter as input to the initial and subsequent
dilution techniques presented elsewhere in this document. The second approach, which is more
complex, is to simulate directly the water quality parameters and the 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 recirculation and build-up of previously discharged
effluent would occur when the water column is density-stratified in the presence of tidally
reversing currents and low nontidal currents and the wastefield 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 diffuser and the segments gradually increase in size with distance from the
diffuser. 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, Connor, et at. 1976; Christodoulou,
Pagenkopf, et al. 1976; Pagenkopf et al. 1976); TEA/ELA (Baptista et al. 1984, Westerink et al.
1985); Spaulding and Pavish (1984); and Sheng and Butler (1982). The applicant must use a
model that is supported by a fully documented computer program so that EPA and other
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interested parties can 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 must respond.
The accumulation of suspended solids from municipal wastewater discharges may lower
dissolved oxygen concentrations in near-bottom waters and cause changes in benthic
communities. Accumulation of suspended solids in the vicinity of a discharge is influenced by
the amount of solids discharged, the settling velocity distribution of the particles in the discharge,
the plume height-of-rise, and current velocities. Hence, sedimentation of suspended solids is
generally of little concern for small discharges into well-flushed receiving waters.
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 is provided in Chapter B-I of Appendix B. A simplified sedimentation model for
large dischargers, or small dischargers for whom the simplified approach is not appropriate, is
also described in Chapter B-I of Appendix B. The sedimentation model DECAL (a simplified
Deposition Calculation) is available as an Ocean Data Evaluation System (ODES) tool.
III.A.5. Sedimentation of suspended solids.
a. What fraction of the modified discharge's suspended solids will
accumulate within the vicinity of the modified discharge?
b. What are the calculated area(s) and rate(s) of sediment accumulation
within the vicinity of the modified discharge(s) (g/m2/yr)?
c. What 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 is needed to calculate oxygen consumption
rates and interpret biological data. Settling velocity distributions of the effluent should be
provided, if available. Graphs showing the settling velocity (cm/sec) and percent of solids that
60
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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 in these calculations. A
simplified procedure for calculating the effect of sedimentation is described in Chapter B-I of
Appendix B.
.
IILB. Compliance with Applicable Water Quality Standards and CWA §304(a)(l)
water quality criteria 140 CFR 125.6Kb) and 125.62(a)J
III.B.l. What is the concentration of dissolved oxygen immediately following
initial dilution for the period(s) of maximum stratification and any other critical
period(s) of discharge volume/composition, water quality, biological seasons, or
oceanographic conditions?
i
*** Large and small dischargers must respond.
Dissolved oxygen in the receiving water is diminished by the low oxygen content and
immediate dissolved oxygen demand (BDOD) of the effluent'within the ZID and by oxidation of
organic material in the diluted effluent beyond the ZID. A simplified procedure for calculating
the dissolved oxygen concentration immediately following initial dilution is explained in Chapter
B-II of Appendix B. Note that some states limit the maximum allowable depression in 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. What 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)?
i • • - . '•
*** Large and small dischargers must respond. •
A simplified procedure for calculating the farfield dissolved oxygen depression is given
in Chapter B-III of Appendix B.
i . . ..
IILB.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.
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Suspended solids that accumulate on the seabed can 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
state 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.
IILB.4. What is the increase in receiving water suspended solids concentration
immediately following initial dilution of the modified discharge(s)?
*** Large and small dischargers must respond.
Suspended solids in the water column can reduce light transmittance and thus water
clarity. Reduction of the depth to which sunlight penetrates can 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 hi 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 solids in the effluent has not changed since
the original application was submitted, and is not expected to change over the term of the new
permit, it will be necessary only to reproduce the calculation provided in the original application.
However, changes in either parameter will necessitate recalculating the receiving water suspended
solids concentration.
III.B.5. What is the change in receiving water pH immediately following initial
dilution of the modified disckarge(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
is small. This section provides a method to calculate 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 hi this table were generated by a pH-alkalinity 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 hi Chapter B-VI of Appendix B. Because waste plumes are usually
submerged during initial dilution, no exchange with the atmosphere is included. The results are
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TABLE 1. ESTIMATED pH VALUES AFTER INITIAL DILUTION
Seawater
Temp.
Seawater
PH
5 °C 15 °C
Initial Dilution
10 25 50 75 100 10 25 50 75 100
1
25 °C
I
1
10 25 50 75 100
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
6.97 6.98 6.99 6.99 6,99
7.40 7.46 7.48 7.48 7.49
7.58 7.65 7.67 7.68 7.68
7.89 7.96 7.98 7.98 7.99
8.23 8.27 8.28 8.29 8.29
8.46 8.48 8.49 8.49 8.49
6.80 6.91 6.95 6.96 6.97
7.05 7.28 7.38 7.42 7.43
7.13 7.42 7.55 7.60 7.62
7.29 7.69 7.85 7.90 7.92
7.57 8.06 8.19 8.23 8.24
7.90 8.32 8.41 8.44 8.46
6.70 6.85 6.92 6.94 6.96
6.89 7.17 7.31 7.37 7.40
6.94 7.28 7.46 7.54 7.57
7.04 7.50 7.74 7.83 7.87
7.20 7.86 8.11 8.18 8.21
7.39 8.17 8.35 8.40 8.43
6.53 6.75 6.85 6.90 6.92
6.64 6.97 7.17 7.26 7,31
6.67 7.04 7.28 7.40 7.46
6.72 7.17 7.50 7.66 7.74
6.79 7.39 7.87 8.03 8.11
6.86 7.67 8.17 8.29 8.35
6.95 6.98 6.99 6.99 6.99
7.35 7.44 7.47 7.48 7.48
7.52 7.62 7.66 7.67 7.68
7.81 7.93 7.96 7.97 7.98
8.16 8.25 8.27 8.28 8.28
8.40 8.46 8.48 8.48 8.49
6.90 6.95 6.97 6.98 6.98
7.23 7.38 7.43 7.45 7.46
7.35 7.55 7.62 7.65 7.66
7.59 7.84 7.92 7.95 7.96
7.96 8.18 8.24 8.26 8.27
8.24 8.41 8.45 8.47 8.48
Effluent pH = 6.0 Alk = 0.1
6.97 6.99 6.99 6.99 6.99
7.42 7.47 7.48 7.49 7.49
7.61 7.66 7.68 7.69 7.69
7.93 7.97 7.99 7.99 7.99
8.27 8.29 8.29 8.29 8.29
8.48 8.49 8.49 8.49 8.49
Effluent pH = 6.0 Alk = 0.6
6.80 6.91 6.95 6.96 6.97
7.07 7.30 7.39 7.42 7.44
7.18 7.46 7.58 7.62 7.64
7.40 7.78 7.90 7.93 7.95
7.82 8.15 8.23 8.25 8.26
8.15 8.38 8.44 8.46 8.47
Effluent pH = 6.0 Alk = 1.0
6.70 6.86 6.92 6.94 6.96
6.90 7.19 7.33 7.38 7.41
6.97 7.33 7.50 ,7.56 7.60
7.12 7.62 7.82 7.88 7.91
7.40 8.02 8.17 8.22 8.24
7.77 8.29 8.40 8.43 8.45
Effluent pH = 6.0 Alk = 2.0
6.53 6.75 6.86 6.90 6.92
6.65 6.99 7.19 7.28 7.33
6.69 7.08 7.33 7.44 7.50
6.76 7.27 7.62 7.75 7.82
6.88 7.64 8.02 8.12 8.17
7.01 8.00 8.28 8.36 8.40
Effluent pH = 6.5 Alk = 0.5
6.95 6.98 6.99 6.99 6.99
7.37 7.45 7.47 7.48 7.48
7.55 7.64 7.67 7.68 7.68
7.87 7.95 7.97 7.98 7.98
8.22 8.27 8.28 8.29 8.29
8.44 8.47 8.49 8.49 8.49
Effluent pH = 6.5 Alk = 1.0
6.90 6.96 6.98 6.98 6.98
7.25 7.39 7.44 7.46 7.47
7.40 7.58 7.64 7.66 7.67
7.70 7.89 7.95 7.96 7.97
8.09 8.22 8.26 8.27 8.28
8.33 8.44 8.47 8.48 8.48
6.97 6.99 6.99 6.99 6.99
7.43 7.47 7.48 7.49 7.49
7.63 7.67 7.68 7.69 7.69
7.96 7.98 7.99 7.99 7.99
8.28 8.29 8.29 8.29 8.29
8.49 8.49 8.49 8.49 8.49
6.1!0 6.91 6.95 6.97 6.97
7.09 7.32 7.40 7.43 7.45
7.;i2 7.50 7.60 7.63 7.65
7.53 7.84 7.92 7.95 7.96
7.98 8.19 8.25 8.26 8.27
8.25 8.41 8.46 8.47 8.48
6.71 6.86 6.92 6.95 6.96
6.92 7.21 7.34 7.39 7.42
7.01 7.38 7.53 7.59 7.62
7.22 7.71 7.87 7.91 7.93
7.65 8.10 8.21 8.24 8.25
8.01 8.34 8.42 8.45 8.46
6.54 6.75 6.86 6.90 6.92
6.67 7.01 7.21 7.30 7.34
6.71 7.12 7.38 7.48 7.53
6.«1 7.39 7.71 7.82 7.86
6.99 7.84 8.10 8.17 8.20
7.23 8.15 8.34 8.39 8.42
6.95 6.98 6.99 6.99 6.99
7.39 7.45 7.47 7.48 7.48
7.58 7.65 7.67 7.68 7.69
7.91 7.97 7.98 7.99 7.99
8.24 8.28 8.29 8.29 8.29
8.46' 8.48 8.49 8.49 8.49
6.90 6.96 6i98 6.98 6.99
7.27 7.40 7.45 7.46 '7.47
7.44 7.60 7.65 7.66 7.67
7.78 7.92 7.96 7.97 7.98
8.15 8.24 8.27 8.28 8.28
8.38 8.45 8.47 8.48 8.48
63
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TABLE 1. (Continued)
Seawater
Temp.
Seawater
PH
5 °C 15 °C
Initial Dilution
10 25 50 75 100 10 25 50 75 100
25 °C
10 25 50 75 100
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
6.82 6.91 6.95 6.97 6.97
7.06 7.28 7.38 7.41 7.43
7.14 7.42 7.55 7.59 7.62
7.28 7.68 7.84 7.89 7.92
7.54 8.04 8.18 8.22 8.24
7.85 8.30 8.40 8.44 8.45
7.06 7.02 7.01 7.00 7.00
7.56 7.52 7.51 7.50 7.50
7.75 7.72 7.70 7.70 7.70
8.03 8.01 8.00 8.00 8.00
8.31 8.30 8.30 8.30 8.30
8.50 8.50 8.50 8.50 8.50
7.10 7.04
7.59 7.53
7.76 7.72
8.02 8.01
8.29 8.29
8.47 8.48
7.02 7.01 7.00
7.51 7.51 7.50
7.71 7.70 7.70
8.00 8.00 8.00
8.29 8.29 8.29
8.49 8.49 8.49
7.14 7.05 7.02
7.61 7.54 7.52
7.78 7.73 7.71
8.02 8.00 8.00
8.27 8.28 8.29
8.44 8.47 8.48
7.01 7.01
7.51 7.51
7.71 7.70
8.00 8.00
8.29 8.29
8.49 8.49
Effluent pH = 6.5 Alk = 2.0
6.82 6.91 6.95 6.97 6.97
7.08 7.29 7.39 7.42 7.44
7.18 7.46 7.57 7.61 7.63
7.39 7.76 7.89 7.92 7.94
7.78 8.13 8.22 8.24 8.26
8.10 8.36 8.43 8.45 8.46
Effluent pH = 9.0 Alk = 2.0
7.06 7.02 7.01 7.00 7.00
7.56 7.52 7.51 7.50 7.50
7.75 7.72 7.71 7.70 7.70
8.03 8.01 8.00 8.00 8.00
8.31 8.30 8.30 8.30 8.30
8.50 8.50 8.50 8.50 ' 8.50
Effluent pH = 9.0 Alk = 4.0
7.10 7.04 7.02 7.01 7.01
7.59 7.53 7.51 7.51 7.50
7.76 7.72 7.71 7.70 7.70
8.02 8.00 ' 8.00 8.00 8.00
8.28 8.29 8.29 8.29 8.29
8.46 8.48 8.49 8.49 8.49
Effluent pH = 9.0 Alk = 6.0
7.14 7.05 7.02 7.01 7.01
7.61 7.54 7.52 7.51 7.51
7.77 7.73 7.71 7.71 7.70
8.01 8.00 8.00 8.00 8.00
8.26 8.28 8.29 8.29 8.29
8.43 8.47 8.48 8.49 8.49
6.82 6.92 6.95 6.97 6.97
7.10 7.31 7.40 7.43 7.45
7.22 7.49 7.60 7.63 7.65
7.50 7.82 7.91 7.94 7.96
7.93 8.17 8.24 8.26 8.27
8.21 8.39 8.45 8.46 8.47
7.07 7.02 7.01 7.00 7.00
7.56 7.52 7.51 7.50 7.50
7.75 7.72 7.71 7.70 7.70
8.03 8.01 8.00 8.00 8.00
8.31 8.30 8.30 8.30 8.30
8.50 8.50 8.50 8.49 8.49
7.11 7.04 7.02 7.01 7.01
7.59 7.53 7.51 7.51 7.50
7.76 7.72 7.71 7.70 7.70
8.02 8.00 8.00 8.00 8.00
8.28 8.29 8.29 8.29 8.29
8.46 8.48 8.49 8.49 8.49
7.15 7.06 7.03 7.02 7.01
7.61 7.54 7.52 7.51 7.51
7.77 7.73 7.71 7.71 7.70
8.01 8.00 8.00 8.00 8.00
8.26 8.28 8.29 8.29 8.29
8.43 8.47 8.48 8.48 8.49
based on a seawater alkalinity of 2.3 meq/L (Stumm and Morgan 1981) and dissociation
constants from Stumm and Morgan (1981) and Dickson and Riley (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 alkalinity can range from 0 to 6.0 meq/L. A typical value for effluent
alkalinity is 2 meq/L or higher (Metcalf and Eddy 1979). Because alkalinity data are scarce,
final pH values calculated for a range of alkalinities are provided in Table 1. If significant
industrial waste is present hi an effluent, or if pure oxygen or nitrification-denitrification
treatment processes are used, effluent pH and alkalinity should be measured. For cases of weak
64
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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 is 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 is 6.0 and the ambient pH is equal to the irunimuna 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.
The applicant may also perform laboratory tests when the predicted pH values in
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 acid ligands) and have
not been included in the calculations used to produce the table. The laboratory test would
include measuring the pH of effluent-receiving water mixtures as discussed below.
1 i ' * ' '" i
/ If the effluent pH drops below 6.0, the applicant should indicate the number of times per
year effluent pH values feh1 below 6.0 and the suspected causes 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 is 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 solids, and pH, in which
65 :
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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 wiU be met. Methods to determine compliance with water quality standards for
DO, TSS, pH, and turbidity are discussed in Appendix B, Chapters B-I to B-VII.
According to §125.57(a)(9), permits may not be issued if the dilution water for the
discharge contains significant amounts of previously discharged effluent. In general, this criterion
will be met if all water quality standards and/or water quality criteria established under section
304(a)(l) of the Clean Water Act, as noted in Question III.B.7 below, are met.
IILB.7. Provide data to demonstrate that all applicable State water quality
standards, and all applicable water quality criteria established under Section
304(a)(l) of the Clean Water Act for which there are no directly corresponding
numerical applicable water quality standards approved by EPA, are met at and
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 is discharged. [40 CFR 125.62(a)(l)]
*** Large and small dischargers must respond.
At the time the 301(h) modification becomes effective, the applicant's outfall and diffuser
must be located and designed to provide adequate dilution, dispersion, and transport of
wastewater to meet, at and beyond the ZED, all applicable water quality standards and all
applicable water quality criteria for which there are no directly corresponding approved water
quality standards. A state water quality standard is considered to "directly correspond" to an
EPA water quality criterion only if (1) the state water quality standard addresses the same
pollutant as that addressed by the EPA water quality criterion and (2) the state water quality
standard specifies a numeric criterion for that pollutant or a state objective methodology for
deriving such a numeric criterion [§125.62(a)]. Compliance with criteria and standards other than
those discussed in Question III.B.6, such as standards for nutrients, toxic pollutants, and coliform
bacteria concentrations at the edge of the ZID, is necessary.
To support this demonstration, applicants should submit pollutant concentration data in
a form that satisfies state water quality regulations and all applicable EPA water quality criteria.
Where average values are given (e.g., average dry-weather flow), applicants should specify how
they were calculated. Applicants should also submit data on the predicted maximum 2- to 3-hour
flow for the end-of-permit year (U.S. EPA 1985e). Monitoring data collected during the term
66
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of the original section 301 (h) permit may be useful for demonstrating compliance with applicable
receiving water standards and criteria, and for verifying predictions made in the original appli-
cation [§125.59(c)(4)]. Detailed guidance for assessing compliance with some specific water
quality standards is provided in Appendix B, Chapter B-VIII. Also note that according to
§125.57(a)(9), permits may not be issued if the dilution water for the discharge contains
significant amounts of previously discharged effluent. In general, demonstrated compliance with
this criterion can be shown if all water quality standards and 304(a)(l) water quality criteria are
met. :
Under the CWA, states may develop water quality standards based on the 304(a)(l)
criteria, as modified to reflect site-specific conditions, or they may use other scientifically
defensible methods for developing water quality standards. State water quality standards are
developed, by states, to protect the types of biota in and beneficial uses of their local waters, and
thus represent scientifically appropriate standards for each state's specific situation. State
standards are subject to EPA review and approval. In the absence of an EPA-approved state
water quality standard that directly corresponds to the section 304(a)(l) water quality criteria for
a given pollutant, EPA requires compliance with the section 304(a)(l) water quality criteria.
To demonstrate compliance with state water quality standards and water quality criteria,
applicants must show that the applicable numerical criteria are not exceeded after critical initial
dilution. For most cases, either analytical or computer models can be used to evaluate the water
quality impacts. The dilution achieved during the initial mixing process is dependent on ambient
and discharge conditions and is, therefore, highly variable. In evaluating a discharge's effect on
water quality, the appropriate conditions to consider are those which result in the "lowest"
dilution and those which occur at tunes when the. environment is most sensitive. For example,
minimum dilution can be predicted using a combination of maximum vertical density
stratification, minimum initial density difference between the effluent and the ambient seawater,
maximum waste flow rate, and minimum currents for a particular site. Other situations may be
more critical depending on the ambient water quality and applicable criteria.
To determine initial dilutions, it is necessary to know specific characteristics of the
discharge, the outfall, and the receiving waters. The discharge volumetric How rate and density
are required. Alternately, the effluent temperature and salinity (major inorganic ions contributing
to density) can be used to estimate density based on known relationships to seawater. Municipal
effluent densities typically range from 0.9970 to 1.0003 g/cm3, and salinities range to 5 ppt. The
highest 2- to 3-hour flow rate during a period of concern should be used to calculate the
minimum initial dilution for that period. The principal environmental quantities to consider in
dilution prediction are the ambient density stratification and local currents. These parameters
67 !
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should be considered for periods of maximum wastewater flow; any other periods of maximum
loadings; and tunes of seasonal maximum and minimum stratification, low ambient water quality,
low net circulation or flushing, or exceptional biological activity. The quantities selected to
represent these periods should reflect lowest 10 percentile conditions (U.S. EPA 1985e).
The critical initial dilution factor can be calculated with any or all of the following data:
(1) effluent monitoring, (2) ambient water quality monitoring, or (3) modeling. A list of toxic
pollutants [as defined in §125.58(p) and (aa)] is found in Table 2, and corresponding marine
water quality criteria are summarized in Table 3. Guidance on sampling and analytical methods
for 301(h) monitoring programs is found in EPA guidance (U.S. EPA 1982a, 1987c, 1987e) and
40 CFR Part 136. Remember, in addition to factoring in reentrainment of previously discharged
effluent, section 301 (h) of the Clean Water Act requires an applicant to demonstrate that the
301(h) modified discharge will not interfere, alone or in combination with pollutants from other
sources, with the attainment or maintenance of water quality. Hence, data on pollutant loadings
in the ambient receiving waters may be required to calculate values of water quality parameters
after initial dilution. Furthermore, the modified discharge must not result in any additional
requirements on any other point or nonpoint sources of pollution [§125.64].
Compliance with water quality standards and the 304(a)(l) water quality criteria in marine
waters can be determined by the applicant's documenting water quality in the vicinity of the ZID
boundary, at control or reference stations, and at areas beyond the ZID where discharge impacts
might reasonably be expected. Monitoring should reflect conditions during all critical
environmental periods as identified in the 301(h) application (e.g., dry-weather flow or maximum
2- to 3-hour flow conditions). Selection of specific sampling station locations depends on the
monitoring requirements. For example, when determining compliance with water quality
standards at the edge of the ZID, sampling stations should be located at various points around
the ZID boundary. Sampling in estuaries should be conducted at slack water. Where tidal
effects are to be discriminated, sampling should be done at several times over a tidal cycle for
both spring and neap tides. To verify continuing compliance with 301(h) requirements, the ZID
boundary stations should be sampled during those times of the year when the discharge is least
diluted (U.S. EPA 1982a).
Applicants should be aware that EPA promulgated the National Toxics Rule (Code of
Federal Regulations, Title 40, Part 131, 57 FR 60848, 22 December 1992),* which establishes
chemical-specific, numeric criteria for the priority toxic pollutants necessary to bring all states
'hereinafter referred to as 40 CFR Part 131.
68
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TABLE 2. LIST OF PESTICIDES AND TOXIC POLLUTANTS
(as defined in §l25.58(p) and (aa))
Pesticides
Demeton
Guthion
MalathiOn
Methoxychlor
Mirex
Parathion
Toxic Pollutants3
Chlorinated Benzenes
Chlorobenzene
1,2-Dichlorobenzene
1,3-Dichlorobenzene
1,4-Dichlorobenzene
1,2,4-Trichlorobenzene
Hexachlorobenzene
Chlorinated Ethanes
Chloroethane
1,1-Dichloroethane
1,2-Dichloroethane
1,1,1-Trichloroethane
1,1,2-Trichloroethane
1,1,2,2-Tetrachloroethane
Hexachloroethane
Chlorinated Phenols
2-Chlorophenol
2,4-Dichlorophenol
2,4,6-Trichlorophenol
4-Chloro-3-methyl phenol
Other Chlorinated Organics
Chloroform (trichloromethane)
Carbon tetrachloride (tetrachloromethane)
bis(2-Chloroethoxy)methane
bis(2-Chloroethyl)ether
2-Chloroethyl vinyl ether (mixed)
2-Chloronaphthalene
3,3-Dichlorobenzidine
1,1-Dichloroethylene
trans-1,2-Dichloroethylene
1,2-Dichloropropane
l,2-Dichloropropylene(l,3-dichloropropene)
Tetrachloroethylene
Trichloroethylene
Vinyl chloride (chloroethylene)
Hexachlorobutadiene
2,3,7,8-Tetrachloro-dibenzo-p-dioxin (TCDD)
Haloethers I
4-Chlorophenyl phenyl ether
2-Bromophenyl phenyl ether
bis(2-Chloroisopropyl) ether
Halomethanes
Methylene chloride (dichloromethane)
Methyl chloride (chloromethane)
Methyl bromide (bromomethane)
Bromofonn (tribrombmethane)
Dichlorobromomethane
Chlorodibromomethane
Nitrosamines
N-Nitrosodimethylamine
N-Nitrosodiphenylamine
N-Nitrosodi-n-propylamine
Phenols (other than chlorinated)
2-Nitrophenol
4-Nitrophenol
2,4-Dinitrophenol ; ' ' .
4,6-Dinitro-o-cresol (4,6-dinitro-2-
methylphenol)
Pentachlorophenol
Phenol
2,4-dimethylphenol
Phthalate Esters
bis(2-Ethylhexyl)phthalate
Butyl benzyl phthallate
Di-n-butyl phthalate
Di-n-6ctyl phthalate
Diethyl phthalate
Dimethyl phthalate
Polynuclear Aromatic Hydrocarbons (PAHs)
Acenaphthene
1,2-Benzanthracene (benzo(a)anthracene)
3,4-Benzo(a)pyrene(benzo(a)pyrene)
69
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TABLE 2. (Continued)
PAHs (continued)
3,4-Benzofluoranthene(benzo(b)fluoranthene)
11,12-Benzofluoranthene (benzo(k)
fluoranthene)
Chrysene
Acenaphthalene
Anthracene
l,12-Benzopeiylene(benzo(g,h,i)perylene)
Huorene
Fluoranthene
Phenanthrene
1,2,5,6-Dibenzanthracene (dibenzo(a,h)
anthracene)
Indeno(l,2,3-cd)pyrene(2,3-o-phenylene
pyrene)
Pyrene
Pesticides and Metabolites
Aldrin
Dieldrin
Chlordane (technical mixture and metabolites)
alpha-Endosulfan
beta-Endosulfan
Endosulfan sulfate
Endrin
Endrin aldehyde
Heptachlor
Heptachlor epoxide (BHC-
hexachlorocyclohexane)
alpha-BHC
beta-BHC
gamma-BHC (Lindane)
delta-BHC
Toxaphene
DDT and Metabolites
4,4-DDT
4,4-DDE (p.p-DDX)
4,4-DDD (p,p-TDE)
Polychlorinated Biphenyls (PCBs)
PCB-1242 (Arochlor 1242)
PCB-1254 (Arochlor 1254)
PCB-1221 (Arochlor 1221)
PCB-1232 (Arochlor 1232)
PCB-1248 (Arochlor 1248)
PCB-1260 (Arochlor 1260)
PCB-1016 (Arochlor 1016)
Other Organics
Acrolein
Acrylonitrile
Benzene
Benzidine
2,4-Dinitrotoluene
2,6-Dinitrotoluene
1,2-Diphenylhydrazine
Ethylbenzene
Isophorone
Naphthalene
Nitrobenzene
Toluene
Inorganics
Antimony
Arsenic
Asbestos
Beryllium
Cadmium
Chromium
Copper
Cyanide, total
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
'Source: U.S. EPA 1993b.
70
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TABLE 3. SUMMARY OF U.S. EPA MARINE WATER QUALITY CRITERIA
(NOTE- This summary should be used only as estimates for the criteria. These values are subject to change. Refer
to the appropriate criteria source (e.g., the current Quality Criteria for Water) for up-to-date criteria values.)
Pollutant
Pollutants with numeric criteria:
Acenaphthene
Acrolein
Acrylonitrile
Aldrin
Anthracene
Antimony
Arsenic
Benzene
Benzidine
Benzofluoranthene 3,4
Benzofluoranthene 11,12
Benzoanthrancene 1,2
Benzopyrene 3,4
BHC
BHC - alpha
BHC - beta
BHC - gamma
Bromoform
Cadmium
Carbon tetrachloride
Chlordane
Chlorinated benzenes
Chlorobenzene
Dichlorobenzenes
Dichlorobenzene 1,2
Dichlorobenzene 1,3
Dichlorobenzene 1,4
Hexachlorobenzene
Pentachlorobenzene
Tetrachlorobenzene 1,2,4,5
Chlorinated ethanes
Dichloroethane 1,2
Hexachloroethane
Pentachloroethane
Tetrachloroethane 1,1,2,2
Trichloroethane 1,1,1
Trichloroethane 1,1,2
Chlorinated ethylenes
Dichlofoethylenes.
Saltwater Acute
Criteria (|ig/L)
970a
. 55a
_b
1.3C
_b
_b
69'
5,100a
_b
_b
_b
_b
b
0.34a
_b
_b
0.16C
b
43'
50,000a
0.09C
160a
_b
l,970a
_b
_b
_b
b
b
_b
113,000"
940a
390a
9,020a
31,200a
b
, 224,000a
Saltwater Chronic
Criteria (ug/L)
710a
_b
_b
_b
_b
_b
361
700a
_b
_b
_b
_b
b
_b
_b
b
_b
_b
9.31
_b
0.004f
129a
_b
_b
b
_b
_b
_b
b
_b
_b
_b
281a
_b
_b
_b
_b
Human Health8 (ug/L)
2,700k
780!
0.6611
0.00014h
10,000h
4,300h
0.14m
71h
0.00054h
0.03 lh
0.031h
0.031"
0.03 lh
_j
0.013h
0.046h
0.063h
a/cnh
J\J\J
n
4.4"
0.00059h
j
21,000"
2,600'
17,000h
2,600"
2,600h
0.00077"
«v
OJ
48' , .
99"
8.9h
_j
11. Oh
_n
42h
_j
71
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TABLE 3. (Continued)
Pollutant
Dichloroethylene 1,1
Tetrachloroethylene
Trichloroethylene
Chlorodibromomethane
Chloronaphthalene 2
Chlorinated phenols
Chlorophenol 2
Chlorophenol 4
Dichlorophenol 2,4
Pentachlorophenol (penta)
Tetrachlorophenol 2,3,5,6
Trichlorophenol 2,4,6
Chlorine
Chloroethyl ether 2
Chloroisopropyl ether 2
Chloromethyl ether
Chloroform
Chlorpyrifos
Chromium
Hexavalent
Trivalent
Chrysene
Copper1
Cyanide
DDT
DDT Metabolites
ODD (TDE)
DDE
Demeton
Dibenzo(a,h)anthrancene
Dichlorobenzidine 3,3
*
Dichlorobromomethane
Dichloropropane
Dichloropropane 1,2
Dichloropropene
Dichloropropylene 1,3
Dieldrin
Dimethylphenol 2,4
Dimethyl dinitrophenol 4,6
Dinitrophenol
Dinitrophenol 2,4
Saltwater Acute
Criteria (|ag/L)
_b
10,200"
2,000a
_b
7.5"
_b
29,700a
_b
13d
440a
_b
13d
_b
_b
_b
_b
0.011°
1,100'
10,300a
_b
2.9'
1.0d
0.13°
3.6a
1 A&
14
_b
_b
b
~
_b
10,300a
10,300a
790a
_b
0.7 lc
_b
_b
_b
_b
Saltwater Chronic
Criteria (|ag/L)
_b
450a
_b
_b
_b
_b
_b
_b
7.9e
_b
_b
7.5e
_b
_b
_b
b
0.0056"
50'
_b
_b
2.9'
1.0e
0.001f
_b
O.le
_b
b
_b
3,040a
3,040a
_b
_b
0.0019f
_b
_b
_b
_b
Human Health8 (fig/L)
3.2h
8.85!
81h
34h
4,300k
400k
_j
790h
' 8.2h
_j
6.5"
j
1.4h
170,000h
0.00184'
470h
_j
_n
_n
0.0311"
_j
220,000h
0.00059h
0.00084"
0.00059"
_j
0.0311"
0.077"
22"
_j
39k
14,100'
l,700h
0.00014"
2,300k
765"
14,300'
14,000"
72
-------
TABLE 3. (Continued)
^Pollutant
Dinitro-o-cresol 2,4
Dinitrotoluene 2,4
Dioxin (2,3,7,8-TCDD)
Diphenylhydrazine 1,2
Endosulfan
Endosulfan sulfate
Endosulfan-alpha
Endosulfan-beta
Endrin
Endrin aldehyde
Ethylbenzene
Fluoranthene
Fluorene
Guthion
Halomethanes
Heptachlor
Heptachlor epoxide
Hexachlorobutadiene
Hexachlorocyclohexane (HCH)
Lindane (gamma-HCH)
HCH (mixture of isomers)
HCH-alpha
HCH - beta
HCH - technical
Hexachlorocyclopentadiene
Indenopyrene 1,2,3-cd
Isophorone
Lead
Malathion
Manganese
Mercury
Methoxychlor
Methyl bromide
Methylene chloride
Mirex
Naphthalene
Nickel
Nitrobenzene
Nitrophenols '
Nitrosamines
Nitrosodibutylamine N
saltwater Acute
Criteria (ng/L)
IE
590a
_b
_b
0.034°
_b
0.034C
0.034C
0.037°
_b
430"
40"
_b
b
12,000a
0.053°
0.053°
32a
0.16°
0.34a
_b
_b
_b
7.0a
_b
12,900a
140d
_b
_b
2.1d
b
_b
b
2,350*
75C
6,680""
, 4,850"
3,300,000" '
Saltwater Chronic
Criteria (ng/L)
b™
370"
b
b
0.0087f
0.0087f
0.0087f
0.0023f
-
b
16"
0.01
6,400a
0.0036f
0.0036f
_b
b
_b
_b
b
b
b
b
_b
5.6e
0.1
_b
0.0256
0.03
_b
''• J> '• : : ' .
0.001
1 _b
8.3f
' ' _b
_b
_b
Human Health8 (\igfL)
765h
9.r
0.000000014'
0.54"
159s
2.0"
2.0" ;
2.0"
0.81"
0.81"
29,000"
370"
14,000"
• J :.
15.7s
0.00021"
OiOOOll"
50"
0.063h
•
0.013"
0.046"
0.0414s
17,400"
0.0311"
490,000"
j
100s
0.15"
.j
4,000"
1,600"
j
j ; . .
3,800"
1,900"
J"
i
0.587s
-------
TABLE 3. (Continued)
Saltwater Chronic
Pollutant
— —
Nitrosodiethylamine N
Nitrosodimethylamine N
Nitrosodiphenylamine N
Nitrosopyrolidine N
N-Nitrosodi-n-propylamine
pH
Phenol
Phosphorous (elemental)
Phthalate esters
Butylbenzyl phthalate
Di-n-butyl phthalate
Diethyl phthalate
Dimethyl phthalate
Ethylhexyl phthalate
Polychlorhiated biphenyls
PCB - 1016
PCB - 1221
PCB - 1232
PCB - 1242
PCB - 1248
PCB - 1254
PCB - 1260
Polynuclear aromatic hydrocarbons
Pyrene
Selenium (inorganic selenite)
Silver
Sulfide (hydrogen sulfide, H2S)
Thallium
Toluene
Toxaphene
Vinvl chloride
Zinc
/did rtx-uu/
;ria (iig/L)
_b
_b
_b
_b
_b
_b
5,800a
_b
2,944a
_b
_b
_b
_b
_b
10a
_b
_b
_b
_b
_b
_b
_b
300a
_b
300C
2.31
_b
2,130a
6,300a
0.21d
_b
OS1
Criteria (ng/L)
~~J>
b
_b
_b
_b
6.5-8.5
_b
0.1
3.4a
_b
_b
_b
_b
_b
0.03f
_b
_b
_b
_b
_b
_b
_b
_b
_b
71f
_b
2f
_b
5,000a
0.0002e
_b
86'
Human Health8 («
0.0012'
8.1h
16h
91.9'
1.4k
-j
4,600,000"
•J
' 5,200k
12,000h
120,000h
2,900,000'
5.9h
0.000079'
0.000045h
0.000045h
0.000045"
0.000045h
0.000045h
0.000045h
0.000045"
0.0311'
11,000"
_j
j
j
6.3"
200,000"
0.00075"
525"
_j
Acenaphthylene
Aluminum (pH dependent)
Atrizine
Benzoperylene 1,12
BHC - delta
Chloride
Chloroethoxy methane 2
Alachlor
Ammonia (pH and temperature
dependent)
Bacteria (use dependent)
Beryllium"
Bromophenyl phenyl ether 4
Chloroalkyl ethers
Chloroethyl vinyl ether 2
^——————
Asbestos
Barium
Beta particle and photon activity
Carbofuran
Chloroethane
Chlorophenoxy Herbicide 2,4,5-TP
'
74
-------
TABLE 3. (Continued)
Chlorophenoxy Herbicide 2,4-D
Dibromochloropropane
Dichloroethylene trans l,2k
Ethylene Dibromide
Haloethers
Methylchlorophenol 3,4
Nitrophenol 2
Oxygen, dissolved
Radium 226/228
Styrene
Trichlorinated ethanes
Xylenes
Chlorophenyl phenyl ether 4
Dichloroethane 1,1
Dinitrotoluene 2,6
Gasses, total dissolved
Iron
Nitrate
Nitrophenol 4
Parathion
Solids, dissolved and salinity
Temperature
Trichlorobenzene 1,2,4
Color
Dichloroethylene cis 1,2
Di-n-octyl phithalate
Gross alpha particle activity
Methyl Chloride
Nitrite
Oil and grease
Phenanthrene
Solids, suspended and turbidity
Tetrachloroethanes
Trichlorophenol 2,4,5
Criterion has not been established for marine water quality.
Tinal acute value, which by 1980 guidelines is instantaneous (U.S. EPA 1986a) •
'MaZum ifr TIT; ^ t0 bexeXCeeded more ^ once every 3 years on the average (U.S. EPA 1986a)
Maximum 96-hour (4-da) average. Not to be exceeded more than once every 3 years (US EPA 1986a)
*
*** presented • reguiatory
tntena for these metals are expressed as a function of the water effect ratio, as defined in 40 CFR 131
mumh K 198° (45 ^ 79331> "d were wi**awn in 1992 (57 FR ,50848)
Maximum 1-hour average. Not to be exceeded more than once every 3 years on the average (U S EPA 1987^
"Max,mum 96-hour (4-day) average. Not to be exceeded more than once every 3 years SI EPA
, ye)
Recalculated values using IRIS, as of December 22, 1992 Toxics Rule 57 FR 6091 1-60916
Wiblisned human health criteria values (U.S. EPA 1986a). ' ]
JNo value available.
- — '*-
-------
adopted for section 301(h) provides consideration of the state's views on an appropriate risk level
or, in the absence of such state input, provides for EPA to consider all relevant information in
setting a risk level. This information will include evidence that the state has consistently used
a particular risk level when establishing its water quality standards for other carcinogens (see 56
FR 2814, 24 January 1991, for a more detailed description).
In the absence of an EPA-approved state water quality standard for a carcinogenic
pollutant, the Administrator will consider a consistently used, or state-adopted or formally
proposed, risk level recommendation with a satisfactory demonstration that the level is adequately
protective of human health in light of exposure and uncertainty factors and population exposed
(refer to Assessing Human Health Risks from Chemically Contaminated Fish and Shellfish: A
Guidance Manual, U.S. EPA 1989a). Exposure factors would include, for example, local patterns
of fish consumption, cumulative effects of multiple contaminants, and local population
sensitivities. Factors related to uncertainty would include, for example, the weight of scientific
evidence concerning exposures and health effects and the reliability of exposure data. The state
demonstration will need to account for the relevant exposure and uncertainty factors, show
adequate public participation in the selection of the risk level, and show that use of the selected
risk level is adequately protective of human health. EPA considers these and other pertinent
factors to complete an overall judgment of human health risk factors. In cases where there is no
consistent state policy or satisfactory state demonstration on which to base a risk level, EPA will
set a specific risk level (for example, 10'6) based on the circumstances of each case.
Additional guidance for demonstrating compliance with applicable state water quality
standards and section 304(a)(l) criteria is provided in Appendix B; under Questions III.B.l
through ffl.B.6 for conventional water quality parameters; under Questions III.E.2 and III.F.1 for
conventional parameters, toxic substances, and pathogens; and under Questions III.H.l and III.H.2
for toxic substances. Guidance for performing the monitoring necessary to demonstrate
compliance with these requirements can be found in the EPA documents Design of 301(h)
Monitoring Programs for Municipal Wastewater Discharges to Marine Waters (U.S. EPA 1982a)
and Summary of U.S. EPA-Approved Methods, Standard Methods, and Other Guidance for 301 (h)
Monitoring Variables (U.S. EPA 1985e). Applicants should also refer to Appendix E of this
document for further guidance regarding toxic pollutant criteria. The "Determinations of
Compliance with Section 301(h) Modified Permit Conditions and 301(h) Criteria" chapter of this
document should also be reviewed.
Another approach that EPA has used to assess the potential impacts of wastewater
discharges on water quality and the biota in the receiving waters is the water quality-based toxics
76
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control approach. Information derived from this approach may be used to further support the
applicant's response. Guidance for implementing the water quality-based toxics control approach
can be found in the Technical Support Document for Water Quality-Based Toxics Control (U.S.
EPA 1985g). Information regarding the water quality-based toxics control approach is briefly
summarized in Appendix F.
IILB.8. Provide the determination required by 40 CFR 125.61(b)(2) for
compliance with all applicable provisions of State law, including water quality
standards 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 §125.61(b)(2). A copy of the letter thai: requests the required
determination may be provided if the determination by the appropriate state agency has not yet
been received. •
HI.C. Impact on Public Water Supplies 140 CFR 125.62(b)l
IILC.l. Is there a planned or existing public water supply (desalinization facility)
intake in the vicinity of the current or modified discharge ?
*** Large and small dischargers must respond.
It is possible that a public water supply (desalinization plant) intake could be
contaminated by marine POTW discharges. Although such a possibility may be remote, the
applicant should verify that no public water supply intakes are located within 16 km (10 mi) of
the discharge. If none exist within 16 km (10 mi) of the discharge, no analyses are required.
The names of the agencies contacted and the person(s) involved should be listed in the
application.
77
-------
IILC.2. If yes,
a. What is the location of the intake(s) (latitude and longitude)?
b. Will the modified discharge(s) prevent the use of intake(s) for public water
supply?
c. Will the modified discharge(s) cause increased treatment requirements for
public water supply(s) to meet local, state, and EPA drinking water
standards?
*** Large and small dischargers must respond.
If the answer to Question III.C.l is affirmative, the location of the desalinization plant
should be shown on a map with the discharge site marked. The travel time to the intake should
be estimated using the average current speed. The applicant should show that all applicable
water quality standards for use as a public water supply are met at the intake and that water
quality at the intake will not result hi any significant increase in treatment requirements to
comply with local, state, and EPA standards for treated water.
IILD. Bioloeical Impact of Discharge [40 CFR 125.62MJ
POTW discharges can affect biological communities in the following ways:
• Modifications to the structure of benthic communities (bottom-dwell-
ing/feeding fishes and invertebrates) caused by accumulation of discharged
solids on the seabed;
» Increases in phytoplankton or macroalgal growth due to nutrient inputs;
• Reductions in phytoplankton or macroalgal growth due to turbidity increases;
• Reductions in dissolved oxygen due to phytoplankton blooms and subsequent
die-offs, leading to mass mortalities of fish or invertebrates;
• Bioaccumulation of toxic substances in marine organisms due to direct
contact with sediment, ingestion of sediment, direct uptake from effluent, or
ingestion of contaminated organisms; and
78
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• Induction of diseases in marine organisms caused by contact with
contaminated sediments, ingestion of contaminated organisms, or exposure
to effluent.
Most 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-dwelling 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 (e.g.,
nitrogen, phosphorus), 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 phytoplankton after massive blooms can cause dissolved oxygen deficiencies
and associated fish or invertebrate kills.
j '
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 communities 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:
. ' i
• Communities that are most susceptible to impacts from POTW discharges;
Communities of threatened and endangered species;
79
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• Communities with aesthetic, recreational, or commercial importance; and
• 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 with benthic macroin-
vertebrates and demersal fishes. Because of their distribution characteristics, both of these
communities can be assessed quantitatively with a reasonable level of sampling effort. Benthic
macroinvertebrates 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 macroinvertebrates may result in secondary impacts on demersal
or other fishes.
Benthic macroinvertebrates and demersal fishes are two important groups that typically
warrant BIP demonstrations. It should not be assumed, however, that these are the only
biological communities that should be studied in all cases. Particular attention should be given
to threatened and endangered species. The concept of a BIP includes any and all biological
communities potentially affected by the discharge.
III.D.1. Does (will) a balanced indigenous population of shellfish, fish, and
wildlife exist:
- Immediately beyond the ZID of the current and modified discharge(s)?
- In all other areas beyond the ZID where marine life is actually or
potentially affected by the current and modified discharge(s)?
*** Large and small dischargers must respond.
The purpose of the question is to demonstrate whether unacceptable biological impacts
are occurring or will occur beyond the ZED as a result of the modified discharge, either alone or
hi combination with other discharges. Effective demonstrations include comparisons of biological
conditions and habitat characteristics among stations or groups of stations at ZID-boundary,
nearfleld, farfield, and reference areas.
80
-------
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 intertrophic effects (e.g., reductions in fish
food organisms), and the potential for involvement of threatened and endangered species and
recreationally or commercially important species.
'
Numerous parameters can 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 opportunistic species). [See U.S. EPA (1987f) for further guidance on the
selection of biological indices.] Physical characteristics of the receiving water that are often
measured include water column characteristics, (e.g., depth, water temperature, salinity, nutrient
concentrations, chlorophyll 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 water.
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 sufficiently 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 parameters (e.g., numbers of species, total abundances, dominance) are
often accompanied by changes in the abundances of opportunistic and poUution-tolerant species.
Additional guidance on the evaluation of biological communities is provided in Appendix C.
i • •
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 in the vicinity of the discharge. Those small applicants used existing
information to demonstrate that the characteristics of the discharge and receiving water 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 water
81
-------
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 alone and in
combination with other discharges (if any exist) [§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; and
• The absence of known or suspected sources of toxic pollutants and pesticides
or low concentrations of these substances in the effluent.
Most small dischargers that previously demonstrated a low potential for impact should be able
to do so again. They need demonstrate only that characteristics of the discharge and receiving
waters 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 water differ from those listed above. In
some cases, the discharge or receiving water 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 water 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 discovered 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 water 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
82
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the vicinity of the outfall. The level of detail that would be expected in such a demonstration
would be comparable to that required of 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 hi 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 require the
applicant to collect biological data in support of the application for permit reissuance. The
applicant should consult with the Region well in advance of the application deadline, especially
if the Region required the collection of additional data. This will give the applicant adequate
time to prepare and execute appropriate studies. Applicants required to perform these field
surveys should consult U.S. EPA (1982a, 1987a, 1987c, 1987f) for guidance on the design and
execution of such surveys. It is the applicant's responsibility to ensure the collection of adequate,
high-quality data during all phases of the necessary studies.
I " ' -
III.D.2. Have distinctive habitats of limited 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 documenting 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 reference areas.
Trends in 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.
I
If available, the applicant should include documentation of any long-term changes in
spatial extent of 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 can damage coral reefs and heavy pedestrian traffic
can degrade rocky intertidal communities.
j
The applicant should evaluate any effects of the discharge with emphasis on the physical,
chemical, and biological conditions that occurred within the distinctive habitats in the vicinity
83
-------
of the outfall during the term of the existing 301 (h) permit. The applicant's discussion should
be oriented toward 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 farfield dispersion;
• Frequency and direction of waste transport; and
• 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 discontinuously within the biogeographic zone, and often only in small areas. When a
suitable reference 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 biogeographic zone. When suitable data are available, the applicant should
assess potential impacts to distinctive habitats of limited distribution by using the graphical and
mathematical tools discussed in Appendix C,
Special Considerations for Small Dischargers
When it appears that a small discharger is causing (or has the potential to cause) impacts
to distinctive habitats of limited distribution, the Region may require the applicant to perform a
detailed assessment of distinctive habitats in 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.l of the questionnaire
is relevant to the performance of such detailed demonstrations. It is the applicant's responsibility
to identify the need for additional data on distinctive habitats and provide adequate time to design
and execute appropriate studies. Moreover, the applicant should work closely with the Region
during all phases of the studies to ensure that adequate, high-quality data are collected.
84
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HLD.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.
•
•• . i •
If fishery resources are present in areas potentially influenced by the discharge, the
applicant should assess the effects of the discharge on these resources by analyzing catch records,
market acceptability, contamination of tissues by toxic substances, prevalence of disease, and
harvest warnings/closures.
.... • i
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: '
• Health-related factors [including paralytic shellfish poisoning (PSP),
bacteriological contamination, and bioaccumulation of toxic substances];
t ,
• Economic or marketing considerations;
i •' • •
• Resource protection closures; and
.
• i
•
• Other regulatory closures. ,
" [••'-.-
; .If closures are the result of 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);
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• 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. Fish and Wildlife Service);
• Regional fishery management councils (contact information available from
National Marine Fisheries Service); and
• County, state, and federal environmental protection and public health
agencies.
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 coliform bacteria concentrations in shellfish as part of a national public health
program. They will also provide information on PSP if it is known to occur in the geographic
area. Depending on the distribution of fishery resources and pollutant levels in receiving waters,
the agencies may also conduct laboratory studies on toxic bioaccumulation 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 is filed by a
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.
Some environmental protection and public health agencies do not routinely assess the
health status offish unless a serious problem with toxics bioaccumulation is suspected in species
sought by commercial or recreational fishermen. However, many state environmental agencies
conduct biological surveys as a part of intensive surveys and use attainability analyses. Also,
numerous agencies are adding fish tissue monitoring to statewide monitoring efforts. Sources
of information on fish diseases or abnormalities include academic institutions or fisheries
agencies, many of which have conducted fish surveys in the vicinity of an outfall. In addition,
the applicant should not overlook the possibility of state environmental agencies as sources of
information.
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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 adversely impacted, or is likely to adversely impact,
important fish resources. Where a survey of fish and/or shellfish is necessary to determine levels
of toxics accumulation in tissues, applicants should consult the EPA guidance documents
Bioaccumulation Monitoring Guidance: 4. Analytical Methods for U.S. EPA Priority Pollutants
and 301(h) Pesticides in Tissue from Estuarine and Marine Organisms (U.S. EPA 1985d) and
Assessing Human Health Risks from Chemically Contaminated Fish and Shellfish: A Guidance
Manual (U.S. EPA 1989a). The first document describes analytical methods that allow for
sensitive analyses of the target compounds with a reasonable amount of laboratory effort. The
second document contains information on how to perform a health risk assessment based on
standard lexicological parameters and criteria. Information on sampling design, target species
selection, sampling location, quality assurance/quality control (QA/QC) protocols, and, other
topics is also presented.
"
III.D.4. Does the current or modified discharge cause the following within or
beyond the ZID: [40 CFR 125.62(c)(3)J ,
.
i
Mass mortality of fishes or invertebrates due to oxygen depletion, high
concentrations of toxics, or other conditions?
- An increased incidence of disease in marine organisms?
i •-.-..
- An abnormal body burden of any toxic material in marine organisms?
Any other extreme, adverse biological impacts?
i
*** Small dischargers must respond to the extent practicable
*** Large dischargers must respond.
This question requires the assessment of several specific potential impacts of POTW
discharges. The applicant should review and summarize available information on occurrences
of mass mortalities of marine organisms in 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 waters with limited flushing characteristics may result from BOD inputs
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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 U.S. EPA 1985a,
1985b, 1985c, 1985d, 1987a).
Many studies have suggested that a relationship exists between the incidence of disease
in marine organisms and contact with POTW effluents. These diseases include exophthahnia in
spotfin croakers (Roncador stearnsit) and white seabass (Cynoscion nobilis), lip papilloma in
white croakers (Genyonemus lineatus), and discoloration in halibut (Macrostomus pacificus)
(McDermott-Ehrlich et al. 1977, Mearns and Sherwood 1974). Bioaccumulation of chlorinated
hydrocarbons and heavy metals has been reported in marine organisms collected near sewage
outfalls off southern California. Affected species included the Dover sole (Microstomus
pacificus), rock crab (Cancer anthonyi), mussel (Mytilus californianus), and rock scallop
(Hinnites multirugosus) (McCain et al. 1992; McDermott et al. 1976; McDermott-Ehrlich et al.
1978; Waterman and Kranz 1992; Young, McDermott, et al. 1976a; Young et al. 1978). A
methodology for portraying the seriousness of probable pollutant-induced diseases to facilitate
defensible decisions is presented in Index of Pollutant-Induced Fish and Shellfish Disease
(National Ocean Survey 1987). Disease prevalence is indexed on a simple numeric scale, with
corresponding categories of seriousness labeled "normal," "warning," and "alarm."
The discharge of sewage effluents containing toxic substances can result in
bioaccumulation, especially in areas of organic sediment accumulation. Toxic heavy metals and
persistent synthetic organic compounds generally have the highest potential for bioaccumulation
in marine organisms (Office of Technology Assessment 1987). 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 bioaccumulation:
• Evidence of effluent transport toward areas used for shellfish harvesting or
• Significant occurrence of important recreational or commercial species and
evidence of potential sediment accumulation near the outfall.
One approach the applicant may use to evaluate the potential for bioaccumulation is to
compare the concentrations of toxic pollutants after initial dilution with EPA aquatic life water
quality criteria. Two types of information are required for this comparison:
(1) Concentration of the pollutant in the discharged effluent and
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(2) Critical initial dilution.
.. i
The value of (1) divided by (2) should then be compared with the available criterion.
Most of the toxic pollutants with a high bioaccumulation potential, however, will be
associated with organic particulates in the discharged effluent. Thus, hi determining
bioaccumulation potential, it is important not only to evaluate concentrations of these substances
in the effluent and in the receiving .water following initial dilution, but also to examine sediment
accumulation patterns. Substantial bioaccumulation 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 bioaccumulation is not a serioms problem even though
toxic substances are present in the effluent, by providing information that demonstrates the
rfollowing:
•
_
• Adequate initial dilution and
I
• Sufficient circulation to prevent localized accumulation of solids or trapping
of effluent plumes in the nearfield and farfield.
The degree to which the applicant may be required to assess bioaccumulation using field
surveys is 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 (Brown et al. 1984; McLean et al. 1992; Young, McDermott,
et al. 1976b; Young et al. 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, McDermott et al.
1976). The degree to which pollutants bioaccumulate in aquatic organisms depends on the type
of food chain, on the availability and persistence of the pollutant, and especially on the physical-
chemical properties of the pollutant (Rand and Petrocelli 1985). The degree of bioaccumulation
is generally correlated with the partition coefficient measured in an octanol-water mixture.
Chemicals with large partition coefficients (e.g., halogenated hydrocarbons) are more likely to
bioaccumulate. The physical fate of trace metals in seawater is directly related to their particle
or biological reactivity (NOAA 1988). Additional guidance on bioaccumulaition can be found hi
Assessing Human Health Risks from Chemically Contaminated Fish and Shellfish: A Guidance
Manual (U.S. EPA 1989). Thus, in cases where an effluent contains substantial amounts of heavy
metals, the potential data requirements would be greater if shellfish resources also occurred in
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potentially impacted areas than if fishes constituted the only locally important resources.
Furthermore, the potential for bioaccumulation 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 moUuscs 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 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 bioaccumulation. Information can be obtained from The 1990
National Shellfish Register of Classified Estuarine Water, which contains data on 3,172
shellfishing areas encompassing 18.7 million acres of classified estuarine and offshore waters in
23 states (National Ocean Survey 1991). Discharges located in areas with limited dispersion,
such as estuaries or embayments, 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 may be appropriate for tissue analyses include
oysters, clams, mussels, crabs, and lobsters (U.S. EPA 1985b).
An additional situation that will influence the requirement for direct assessment of
bioaccumulation 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 is important for the applicant to
demonstrate that its discharge is not contributing to the existing contamination. This demonstra-
tion can be accomplished by the previously described analyses of effluent pollutant concentrations
and initial dilutions, and/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
bioaccumulation and sufficient data are not available to determine pollutant sources in areas of
existing contamination of fishery resources. Where a survey offish and/or shellfish is necessary
to determine levels of toxics accumulation in tissues, applicants should consult the EPA guidance
documents Bioaccumulation Monitoring Guidance: 4. Analytical Methods for U.S. EPA Priority
Pollutants and 301(h) Pesticides in Tissue from Estuarine and Marine Organisms (U.S. EPA
1985d) and Assessing Human Health Risks from Chemically Contaminated Fish and Shellfish:
A Guidance Manual (U.S. EPA 1989a). These documents contain information on how to perform
a health risk assessment based on standard lexicological parameters and criteria. Information on
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sampling design, target species selection, sampling location, QA/QC protocols, etc. is also
, i
presented.
Special Considerations for Small Dischargers
i -,
As indicated in the regulations [125.63(b)(2)], small applicants are not subject to the
biological monitoring requirements of paragraphs 125.63(b)(l)(ii) through (iv) under special
circumstances, which relate to assessments required for this question. These special
circumstances include discharging at depths greater than 10 meters and demonstrating through
a suspended solids deposition analysis that there will be negligible seabed accumulation in the
vicinity of the modified discharge. Many of the small applicants used existing information to
demonstrate that the characteristics of the discharge and receiving water 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 water 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 alone and in
combination with other discharges (if any exist) [§125.57(a)(2)]. The following characteristics
indicate a low potential for impact:
i
• Location of the discharge in water depths greater than 10 m (33 ft);
• Hydrographic conditions that result in low predicted solids accumulation
rates; .
i • • • <
• 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; and ,
j , ' •
• The absence of known or suspected sources of toxic pollutants and pesticides
in the effluent.
Most small dischargers that previously demonstrated a low potential for impact should be able
to do so again. They need demonstrate only that characteristics of the discharge and receiving
water 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.
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Some small dischargers may not be able to demonstrate a low potential for impacts
because the characteristics of the discharge or receiving water differ from those listed above. In
some cases, the discharge or receiving water 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 water 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 discovered 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 water 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 of 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 requke 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 requke the
applicant to coUect biological data in support of the application for permit reissuance. It is the
applicant's responsibility to identify the need for additional biological data and provide adequate
time to design and execute appropriate studies. Moreover, the applicant should work closely with
the Region during all phases of the studies to ensure that adequate, high-quality data are
collected. Applicants requked to perform these field surveys should consult U.S. EPA (1982a,
1987a, 1987c, 1987f) for guidance on the design and execution of those surveys.
IILD.5. For discharges into saline estuarine waters: [40 CFR 125.62(c)(4)J
- Does or will the current or modified discharge cause substantial
differences in the benthic population within the ZID and beyond the ZID?
- Does or will the current or modified discharge interfere with migratory
pathways within the ZID?
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Does or will the current or modified discharge result in bioaccumulation
of toxic pollutants or pesticides at levels which exert adverse effects on the
biota within the ZID?
i - ' '
No section 301(h) modified permit shall be issued where the discharge enters into
stressed saline estuarine waters as stated in 40 CFR 125.59(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 any of the following characteristics regardless of the
causes of any of those conditions:
• 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.
Estuaries are generally more productive than nonestuarine 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 is generally a higher potential impact in estuaries than in open coastal
environments. j
i. ....
Additional information is required for saline estuarine discharges. U.S. EPA regulations
[§125,62(c)(4)] require applicants to demonstrate that no substantial differences exist between the
benthic communities within the ZID and those beyond the ZID. Hence, applicants discharging
into saline estuaries must compare benthic communities within the ZID and beyond the ZID
boundary with benthic communities at reference sites.
The applicant should also assess the degree to which the discharge could interfere with
migratory pathways within the ZID. Where a survey of fish and/or shellfish is necessary to
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determine levels of toxics accumulation in tissues, applicants should consult the EPA guidance
documents Bioaccumulation Monitoring Guidance: 4. Analytical Methods for U.S. EPA Priority
Pollutants and 301(h) Pesticides in Tissue from Estuarine and Marine Organisms (U.S. EPA
1985d) and Assessing Human Health Risks from Chemically Contaminated Fish and Shellfish:
A Guidance Manual (U.S. EPA 1989a). These documents contain information on how to perform
a health risk assessment based on standard toxicological parameters and criteria. Information on
sampling design, target species selection, sampling location, QA/QC protocols, and other topics
is also presented. In conducting this assessment, the applicant can calculate the proportion of the
cross sectional area of the estuary that is influenced by the ZID. The potential for migratory
interference can 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 estuarine discharges must also assess the bioaccumulation of toxic
substances within the ZID (see U.S. EPA 1985a, 1985b, 1985c, 1985d, 1987d). There are several
advantages of using caged indicator species versus indigenous species to monitor bioaccumulation
(U.S. EPA 1992a). However, results using caged organisms may not provide an accurate
estimate of the bioavailability of certain contaminants occurring at the site. 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 (U.S.
EPA 1986a).
Special Considerations for Small Dischargers
When there is reasonable concern that one or more of the three foregoing conditions
prohibiting the issuance of section 301(h) modified permits for discharges into saline estuaries
has come into existence during the term of an existing section 301 (h) modified permit, the
Regions may require small applicants to demonstrate successfully that none of the 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 n.C.l and m.D.l (above) and in section III.F for guidance on the
design and execution of detailed biological surveys. It is the applicant's responsibility to identify
the need for a detailed biological survey to document the absence of stressed conditions in the
receiving water and to allow adequate time to design and execute appropriate studies. Moreover,
the applicant should work closely with the Region during all phases of the studies to ensure that
adequate, high-quality data are collected.
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IILD.6. For improved discharges, will the proposed improved discharge(s) comply
with the requirements of 40 CFR 125.62(a) through 125.62(d)? [40 CFR
125.62(e)]
*** Large and small dischargers must respond.
i
I
EPA regulations require applicants that propose discharge improvements to demonstrate
that the improvements will result in compliance with §125.62(a) through (d). This demonstration
might be accomplished by comparing conditions at the outfall location with conditions near
discharges that are similar to the proposed improved discharge. Assuming that there is a basic
similarity in indigenous biota of the receiving water, 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 solids following discharge improvements. . ,v .
'• . I
Applicants whose discharge improvement plans include outfall relocation should describe
existing biological conditions at both the existing and proposed outfall sites. Those applicants
are also to predict future biological conditions at the proposed site following relocation of, the
outfall. Such predictions might be made on the basis of comparisons with other discharges that
are similar to the relocated discharge. Discharges used for such comparisons should be located
in receiving waters similar to the applicant's.
III.D.7. For altered discharge(s), will the altered discharges) comply with the
requirements of 40 CFR 125.62(a) through 125.62(d)? [40 CFR 125.62(e)]
|
*** Large and small dischargers must respond.
Applicants requesting 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 resulting from population growth or industrial growth within
the service area will still enable compliance with §125.62(a) through (d) as well as the
appropriate state's antidegradation requirements. These predictions of compliance with 301(h)
criteria during the 5-year 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: [40 CFR 125.62(f)]
~
! .
Contribute to, increase, or perpetuate such stressed condition?
I
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Contribute to further degradation of the biota or water quality if the level
of human perturbation from other sources increases?
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 an 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 exist, the area! extent and magnitude of those stresses should be documented.
Because stressed water determinations are largely based on biological conditions in the receiving
water, the Region may require applicants to perform detailed biological surveys. Applicants
required to perform detailed biological surveys for the purpose of determining whether stressed
conditions exist hi the receiving water should consult section III.F of this document and guidance
documents cited therein for information on the design and execution of those surveys. It is the
applicant's responsibility to identify the need for a detailed biological survey to determine
whether stressed conditions exist in the receiving water and to allow adequate time to design and
execute appropriate studies. The applicant should work closely with the Region during all phases
of the studies to ensure that adequate, high-quality data are collected.
IILE. Impacts of Discharge on Recreational Activities [40 CFR 125.62(d)l
It is necessary to ensure that a 301(h) modified discharge (1) will meet water quality
standards relevant to recreational activities beyond the ZED and (2) will not cause legal
restrictions on activities that would be lifted or modified if the applicant's POTW were updated
to secondary treatment.
III.E.l. 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 in the biological evaluation section. Other activities involving contact
with water may be affected by microbial contamination. For recreational impact assessment,
dispersion and transport of the effluent need to be considered in conjunction with the applicant's
disinfection procedures.
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All recreational activities currently occurring within the bay, estuary, or an 8-km (5-mi)
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 that indicates the
location of current activities, along with the location of the existing or proposed outfall, should
: be provided. Qualitative or, whenever possible, quantitative information that indicates the extent
of the existing activities should be provided. This information could include the number of boats
or boat slips in the area, species of fish and shellfish recreationally harvested, size of catch, and
number of beach user days.
IILE.2. What are the existing and potential impacts of the modified discharge(s)
on recreational activities? Your answer should include, tut not be limited to, a
discussion of fecal coliform bacteria.
*** Large and small dischargers must respond.
I •
Water quality standards for protecting recreational uses, particularly coliform bacteria or
enteroeocci standards, should be provided. Water classifications within 8 km (5 mi) 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 coliform
or enteroeocci bacteria monitoring data for the effluent obtained at the ZID boundary and on the
adjacent shoreline should be submitted. 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 noncompliance with coliform bacteria standards
is noted, an explanation and corrective measures should be provided. Other sources of coliform
bacteria present in the area that could be contributing to the problem should be identified.
III.E.3. Are there any Federal, State, or local restrictions on recreational activities
in the vicinity of the modified discharge(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 the restrictions, the date implemented,
and the agency responsible (e.g., state department of health) should be indicated.
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IILE.4. If recreational restrictions exist, would such restrictions 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 in the discharge quality
would modify or eliminate the restriction on recreational activities, this should be indicated. In
all such events, it should be determined whether secondary treatment would improve the
discharge sufficiently to allow the restriction to be modified.
HLF. Establishment of a Monitorine Program [40 CFR 125.63]
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 or
criteria, and to monitor the effectiveness of the urban pretreatment and toxics control programs.
Only those scientific investigations which are necessary to study the effects of the proposed
discharge should be included in the scope of the monitoring program [§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 dischargers.
The monitoring program consists of four parts: biological, water quality, influent, and
effluent. Although each of these parts involves sampling at different locations and for different
parameters, they should not be considered as independent activities, but as an integrated study.
In this manner, the applicant will be able to meet the specific objectives of each part 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, influent, and effluent
monitoring parameters, 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 is to evaluate continued compliance with the BIP requirements. This
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demonstration can be accomplished by conducting periodic (e.g., quarterly) seasonal surveys of
i
biological communities.
Biological communities selected for study in the monitoring program should include those
communities which are most likely affected by the discharge. As is the case for BIP
demonstrations in the original application, the monitoring program should address any biological
effects hi 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 detectable differences in biological characteristics are adverse.
i "
Bioaccumulation 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 National Research Council (1989) and, more recently, U.S.
EPA (1992b) have completed studies on the assessment and classification of contaminated
sediments. Also, considerable work is currently under way on how contaminated sediments and
the potential for bioaccumulation are related.
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 biological monitoring program, in particular to assist im the interpretation of
observed biological differences.
! • '
j
Monitoring POTW influent and effluent is important for providing supplementary
information for both the water quality and biological programs. Influent and effluent data are
also used as a means of demonstrating continued compliance with the. modified permit effluent
limitations and removal efficiency requirements, and as a data source for permit renewal
applications.
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///.F.I. Describe the biological, water quality, and effluent monitoring programs
which you propose to meet the criteria of 40 CFR 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 301(h) monitoring program [40 CFR
*** Large and small dischargers must respond.
The extent of the monitoring program required as part of a section 301(h) variance will
depend on the characteristics of the discharge and the receiving water. Monitoring of the
influent, 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 in
Design of301(h) Monitoring Programs for Municipal Waste-water Discharges to Marine Water
(U.S. EPA 1982a) and Framework for 301(h) Monitoring Program (U.S. EPA 1987e). Although
some technical information (primarily literature citations, analytical protocols, and legal citations
and requirements) provided in U.S. EPA (1982a) has been superseded, most of the information
is still valid and applicable to the design of 301 (h) monitoring programs. More recent documents
(e.g., U.S. EPA 1985e, 1986c, 1987c, 1987e) include the addition of recent literature citations,
updated analytical protocols, and updated legal citations and requirements. The updated
information in these more recent documents, together with the earlier guidance provided by U.S.
EPA (1982a, 1987e), is 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:
• U.S. EPA (1987a) for information on positioning methods in nearshore
marine and estuarine waters;
• U.S. EPA (1985c, 1985d, 1985e, 1986c) for information on analytical
methods;
• U.S. EPA (1987c) for information on quality assurance/quality control
procedures for field and laboratory methods;
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• U.S. EPA (1985a, 1985b, 1985c, 1985d, 1987d) for information on bio-
accumulation monitoring studies;
• U.S. EPA (1987b) for information on fish liver pathology monitoring studies;
and
• U.S. EPA (1989a) for information on human health risk assessments
associated with contaminated fish and shellfish.
I
j
The full titles and facts of publication for these documents can be found in the reference section
of this manual.
Biological Monitoring
I
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 bioaccumulation studies and examination of possible adverse effects
of effluent-related toxic substances;
i .
(3) Periodic sampling of sediments; and
•••••'•
(4) Periodic assessment of commercial or recreational fisheries (if present).
Small applicants are not subject to items (2) through (4) above if they discharge at depths greater
than 10 meters and if they demonstrate through a suspended solids deposition analysis that there
will be negligible seabed accumulation in the vicinity of the modified discharge.
.1
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 which are
practicable and appropriate in the receiving water. When the applicant believes that one or more
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of the aforementioned study types is not practicable, a justification for the proposed deletion from
the monitoring program should be provided. Examples of situations in 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 appropriate).
Monitoring program specifications supplied by the applicant must include the following
information:
• Biological groups to be sampled;
• Sampling methods;
• Station locations;
• Sampling schedules;
• Preservation techniques;
• Analytical techniques;
• Quality assurance/quality control procedures;
• Statistical analyses; and
• Taxonomic sources.
The three types of sampling stations that should generally be included in 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; and
• In control (i.e., reference) areas.
Monitoring at intermediate sites 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
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discharges involving outfall relocation, monitoring must be conducted at the existing discharge
site until cessation of discharge, and at the relocation site.
Selection of control stations is one of the more important aspects of monitoring program
design because BIP comparisons will rely on data from these sites. Control, stations should be
located in areas not influenced by the applicant's previous or existing discharge or other pollutant
sources. Sediment characteristics at control station(s) should be similar to those expected to
occur naturally in the vicinity of the discharge. Discharge and control stations should be located
j
at similar water depths. i
Bioaccumulation studies are to be included in the monitoring program to evaluate the
potential adverse effects of toxic substances. Section III.D.4 provides additional discussion on
bioaccumulation studies. In situ bioassays may be needed on a case-by-case basis. Caged
specimens of bivalve molluscs (e.g., Mytilus edulis or M. californianus) are recommended as test
organisms for in situ bioassays. Exposures should be conducted in the discharge vicinity and at
an appropriate reference site. Additional exposure sites may be necessary for large dischargers,
especially in situations where other pollutant sources contribute toxic substances to the receiving
water body. Those toxic pollutants and pesticides known or suspected in the applicant's
discharge need to be measured in the exposed organisms. Specific guidance on bioaccumulation
studies can be found in the following documents:
• Bioaccumulation Monitoring Guidance: 1. Estimating the Potential for
Bioaccumulation of Priority Pollutants and 301(h) Pesticides Discharged into
Marine and Estuarine Waters (U.S. EPA 1985a).
I
• Bioaccumulation Monitoring Guidance: 2. Selection of Target Species and
Review of Available Bioaccumulation Data (U.S. EPA 1985b).
.
• Bioaccumulation Monitoring Guidance: 3. Recommended Analytical
Detection Limits (U.S. EPA 1985c).
Bioaccumulation Monitoring Guidance: 4. Analytical Methods for U.S. EPA
Priority Pollutants and 301(h) Pesticides in Tissues from Estuarine and
Marine Organisms (U.S. EPA 1985d). i
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• Summary of U.S. EPA-Approved Methods, Standard Methods, and Other
Guidance for 302(h) Monitoring Variables (U.S. EPA 1985e).
• Analytical Methods for U.S. EPA Priority Pollutants and 301 (h) Pesticides
in Estuarine and Marine Sediments (U.S. EPA 1986c).
• Guidance for Conducting Fish Liver Pathology Studies During 301(h)
Monitoring (U.S. EPA 1987b).
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. Within-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 occurring.
Recommended organisms for such analyses include demersal fishes (e.g., flounder or sole),
epibenthic megainvertebrates (e.g., crabs or lobster), or sessile filter-feeding organisms (e.g.,
clams, mussels, or oysters). Detailed guidance on sediment sampling can be found in Analytical
Methods for EPA Priority Pollutants and 301 (h) Pesticides in Estuarine and Marine Sediments
(U.S. EPA 1986c).
Sediment samples should also be analyzed for characteristics that would support the water
quality and biological surveys. These parameters should include particle size distribution and
total volatile solids. Other parameters, such as BOD5, sulfides, and total organic carbon, are also
useful and may be required by some states.
If recreational or commercial fisheries are present hi areas potentially affected by the
discharge, the applicant should 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 of available
fisheries data. These evaluations should 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 period and level of effort of fishery surveys will depend on the size and
location of the discharge, concentrations of toxic substances hi the effluent, species harvested,
and importance of the commercial or recreational fishery.
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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 and to measure the
presence of toxics identified or expected in the effluent. However, some pollutants are not
readily detected in the water column alone. As a result, the collection of biological data and
sediment sampling are necessary for a comprehensive monitoring program.
The water quality measurements usually required include dissolved oxygen, BOD5,
suspended solids, 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 parameters, However, because the Secchi disc provides cumulative data on
water transparency measured from the surface down to the depth at which the Secchi disk
disappears from sight, the Secchi disc should not be used to detect the effect of a submerged
plume on light transmittance.
I
.Other parameters 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 particulates, color, settleable solids, surface oil arid grease, total and fecal
coliform bacteria, and enterococci bacteria. Samples for these parameters should be collected
1.0 m (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^
monitoring program should specify the parameters for which profiles are to be taken along with
the sampling interval. Table 2 provides a list of the priority pollutants and 30 l(h) pesticides.
For existing discharges, stations should be located in the following areas:
-.''-'
• ZID boundaries (both upcurrent and downcurrent);
i
• Control (i.e., background) stations along the primary axis of the longshore
component of the current (both upcurrent and downcurrent);
'
• Intermediate upcurrent stations between the ZID boundary ;and the upcurrent
. control station; and
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• 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
in selecting sampling station locations in potentially impacted areas. Sampling stations located
at the ZED 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 recrrculation of previously discharged effluent (by reversing tidal currents, upwelling,
or stagnant net circulation). Data should be collected at the intermediate and ZED 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
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 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 latitudes, longitudes, and depths
of the stations should be specified.
Sampling frequencies should be selected to comply with state requirements and to provide
data for critical periods. In most cases, quarterly surveys that include the critical periods (e.g.,
time of maximum stratification) 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. [For
detailed guidance on quality assurance/quality control procedures for field and laboratory
methods, refer to Quality Assurance/Quality Control Procedures for 301 (h) Monitoring Programs
(U.S. EPA 1987c)J
Influent and Effluent Monitoring
The major objectives of treatment plant monitoring are to provide data for determining
compliance with permit effluent limitations, section 304(a)(l) water quality criteria, 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
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addition, influent and effluent monitoring provides data for assessment of treatment plant
performance that may be required to meet modified discharge permit conditions.
I . ,
Parameters that should be measured in the influent are BOD5 and suspended solids;
however, other parameters may also require measurement. Parameters that should be measured
in the effluent are BOD5, suspended solids, pH, dissolved oxygen, section 304(a)(l) water quality
criteria pollutants, 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 §125.58(aa) and (p).
Monitoring of other parameters, such as grease and oil, settleable solids, nutrients, fecal coliform
bacteria, pathogens, and temperature, may also be required by other permit conditions or
monitoring requirements.
i
Required influent samples should be collected just downstream of any coarse screens or
grit chambers.. Effluent samples should be collected downstream of any chlorination or
disinfection units. Effluent samples to be analyzed for toxic substances should be collected just
upstream of the outfall. Sample collection and analysis should be performed as required in 40
CFR Part 136, or as specified by EPA.
III.F.2. Describe the sampling techniques, schedules, and locations, analytical
techniques, quality control and verification procedures to be used.
I
*** Large and small dischargers must respond.
The following information must be provided for all portions of the proposed monitoring
I
program: . . \
i • •
• Parameters to be measured; ;
• Sampling methods;
• Sampling schedule;
• Sampling locations; ;
• Analytical techniques; and |
i
• Quality control and verification procedures. i
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Guidance on the above subjects is provided in the documents listed under Question III.F.1.
Current EPA-approved methods should be used for all parameters. Additional guidance on
navigational requirements is provided in Appendix D.
IILF.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.
*** 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 term of the modified discharge permit if a section 301(h) modification is granted. The
applicant should review state monitoring requirements to ensure that the proposed program meets
those requirements.
ULG- Effect ofDischaree on Other Point and Nonnoint Sources [40 CFR 125.641
IILG.l. 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 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 on other sources is small, further
analysis may not be needed. Otherwise, an analysis of compliance with water quality standards
at the other discharger sites is appropriate for determining the effects of the applicant's discharge
at those sites. For most small POTW discharges, the effects on other sources should be
negligible.
Li 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.
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III.G.2. Provide the determination required by 40 CFR 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.
I
' ' •' I
If the required determination has not been received when the application is submitted to
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 EPA.
IIIH Toxics control Program and Urban Area Pretreatment Program [40 CFR
125.65 and 125.66]
|
The toxics control program is designed to identify and ensure control of toxic pollutants
and pesticides discharged to the POTW. The section 301 (h) toxics control provisions (§125.66)
require both industrial and nonindustrial source control programs. In addition, applicants serving
a population of 50,000 or more must now comply with the urban area pretreatment requirements
under §125.65. Applicants must also comply with the pretreatment program requirements and
compliance schedules in 40 CFR Part 403, The pretreatment program regulations [40 CFR
403.8(d)] require all industrial pretreatment programs to have been approved by 1 July 1983.
U.S. EPA's section 301(h) toxics control program regulations (§125.66) apply to all
30100 applicants'. However, small applicants that certify that there are no known or suspected
sources of toxic pollutants and pesticides to the POTW are-relieved of most of the cost burden
for industrial pretreatment toxics control program development.
i
III.H.1. a. Do you have any known or suspected industrial sources of toxic
pollutants or pesticides?
b. If no, provide the certification required by 40 CFR 125.66(a)(2) for small
dischargers, and required by 40 CFR 125.66(c)(2) for large dischargers.
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c. Provide the remit, of wet and dry weather effluent analyse, for toxic
pollutants and pesticides as required by 40 CFK 125.66(a)(l).
d. Provide an analysis of known or suspected industrial sources of toxic
pollutant, and pesticides identified in (l)(c) above in accordance with 40
CFR 125.66 (I,).
« f"° *"*"»"• ~ ' re^"rf "> P°«* • — » '"rough d to the extent practicable.
* Large dischargers must respond to parts a through d.
Applicants must conduct an industrial waste survey, as described in 40 CFR 403 8ffl(2>
as the basis for determining whether there are any known or suspected industrial sources of toxic
EPA
" UanS a" ""'
indnd - »d
"'"^^-otaownorsuspectedindustrialsourcesoftoxicpollutantsorpcsticides the
t must certify mis fact, based on the results of an industria! waste survey
Md smaU Wlicailte must submit results of wet- and dry-weather analyses of the
p '1™0™ or suspected fadustrial
,
Z d ^ T Perf0mied °n " minimUm °f "" 24-"<»- Composite effluent sampies
(one dry-weather and one wet-weather). Applicants subject to the urban area pretreatment
"«••• -der 1 125.65 must also conduct representative sampUng and ana,ysis of the POTW
mflueat effluent and sludge for toric PoUutaK. The ^treatment Regulations (40 CFR Part
9 ' T"te 40' *« 5"3, 58
9387, 19 February 1993 (Smndards for the Use or Disposa. of Sewage Sludge). Sludge
sampling ,s reqmred m order to determine compliance with 40 CFR Part 503. Other applicants
not subject to the pretreatment Cations may also be required to conduct sludge sampled
analysis. The HOWS** Sampling and Analysis Guidance Docwnen, (US EPA 198%)
proves guidance on sludge sampling and analysis. If historic data are available, they should
hereinafter referred to as 40 CFR Part 503.
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be presented as well. Results of the analyses should be tabulated in a summary form that allows
fceTxie quality of the discharge to be evaluated. The applicant should describe *e samphns
effort by describing the procedures for collecting, compositing, and preserving the samples. The
of grab samples taken for volatile organics analysis should be incl.ded in the discussion.
Rainfall data submitted for at least 5 days preceding the sampling will confirm wet or dry
conditions a, the time of sampling. In past analyses (Feiler 1980), toxics ™™™°™^
been substantially higher on Monday through Friday than on Saturday and Sunday. I, . therefore
recommended thlt composite effluent samples no, be collected on weekends unless it can be
shown that this sampling period is more representative. ;
I
Analytical methods should be discussed, with appropriate references to published
analytical pLedures. The analytical laboratory should be identified. Quality _«« «
"oelres for the analysis should be summarized, and results presented for review. Differences
between the we,- and dry-weather analyses should be explained, if possible. Also, a comparison
with past results can 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 ttns .dentlficauon
andtZrization is to provide a useful reference for toxics monitoring and source controls. I
fce applL, recognizes that the source list requires improvement, procedures to accomplish this
"mentshouTdbe described. In-sys,em sampling and analysis, industrial «e*
and site inspections could yield quantitative information » to sources of identified
tants. A list entitled "Industrial Categories Subject to National Categorical
Standards' can be found at 40 CFR Part 403, Appendix C Additional .nformation
pretreatmen, standards can be found at 40 CFR 403.6 «. under appropriate
sections of 40 CFR chapter I, subchapter N (Effluent Guidelrnes).
In the original section 30100 application, unless required by the state, many small
applicants were exempted from providing an analysis of toxic substances and pesticide* m tar
JLnt because they were able to certify that there were no known or suspected sources of those
substances in their service area. However, those exemptions were not permanent (U.S. EPA
"section 125.63(d) requires all section 30104 modified permit holders to analyze the,
fluent for toxic substances and pesticides, to the extent practicable, - par, of ~=
programs and to measure the effectiveness of the toxic control program. Hence, to the extent
praSeTble, aU section 30100 permittees will have performed at least oee effluent analysis for
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toxic substances at a representative time during the 5-year term of the original section 301(h)
permit. To the extent practicable, they will also perform another effluent analysis for toxic
substances at a representative time during the 5-year term of the reissued permit. Results of
those analyses should be used to demonstrate compliance with federal water quality criteria.
IILH.2. a. Are there any known or suspected water quality, sediment accumu-
lation or biological problems related to tojcic pollutants or pesticides from your
modified discharge(s)?
b. If no, provide the certification required by 40 CFR 125.66(d)(2) together
with available supporting data.
c.
If yes, provide a schedule for development and implementation of
nomndustrial toxics control programs to meet the requirements of 40 CFR
125.66(d)(3).
d. Provide a schedule for development and implementation of a nonindustrial
toxics control program to meet the requirements of 40 CFR 125.66(d)(3).
*** Small dischargers must respond to parts a through c
&&dk 7" _T- T
""• Large dischargers must respond to part d.
. of nonindustrial source contort programs is to identify the specific
nonrndustnal sources of priority pollutants and pesticides and then to develop specific means for
the* control. To properly address these requirements, the applicant should describe existing
programs or present a schedule and description of proposed programs to identify and control non
mdustaa, sources of toxic pollutants and pesticides. A, a minimum, au applicants must develop
a public education program to limit nonindustrial sources (see Question m.H.3 below).
mn ,„ f C°ntr01 Pr°gramS must be de«>loped *»d implemented within 18
months of the issuance of a section 301(h) modified permit; applicants for reissued 301ft)
Z^TT ^ ^ nODindUSttiaI S°Urce ««* P"*™* » P'ace. Tne schedule m s
include the following two elements:
• A schedule of activities for identification of nonindustrial sources of toxic
pollutants and pesticides and
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. 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
poolg of information with other POTW operators having a similar mix of user, ™—^
should also consult the data and guidance on nonindustrial sources provided by EPA (U.S. EPA
199 la).
There are no clearly defined rules to determine the level of effort that an applicant should
apply to identify nonindustrial sources. This level of effort, however, is expected to be directly
reTated to the size of the discharge, For example, dischargers with diverse land uses w*hm he
service area may find it necessary to perform uvsystem sampling and analysis to explain the
occurrence of toxic pollutants and pesticides.
Concentrations of pollutants within the system 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.
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 containing priority pollutants and pesticides.
EPA recognizes the potential for serious adverse effects on marine organisms and humans
that can result from the accumulation and bioaccumulation of discharged toxic pollutants and
pesticides. EPA also recognizes the potential complexity of nonindustrial source conttol
programs. Therefore, applicants are encouraged to consult with EPA during development of
nonindustrial source control programs. Proposed nonindustrial source control programs are
^ct to review and revision by EPA prior to the issuance of a section 301(h) modified permit
and during the term of any such modified permit.
IIIH3 Describe the public education program you propose to minimize the
entrance of nonindustrial toXic pollutants andpesticides into your treatment system
[40 CFR 125.66(d)(l)]
*** Large and small dischargers must respond.
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the
„„ • „ , ""' m°St PrOP°Se a PUWiC edUCatton ""
normal toxto pollutant and pesticides tha, enter the waste stream.
developed and unplemented wiMn lg months of ^
apphcants ^issued 30,00 modified permits mus, have apublic education p
The pubhc educate program may inc.ude preparation of newspaper articles poLrs
and te.ev.ston announcements to increase public awareness of the need for proper cnspo
waste ous, solvents, herbicides, pesticides, and other substances that contain Jc po,hZt
of
I1LH.4.
Do you have an approved industrial pretreatment program (40 CFR
125.66(c)(l)?
a- If yes, provide the date of EPA approval.
If no, and if required by 40 CFR Part 403 to have an industrial
pretreatment program, provide a proposed schedule for development 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 ™^n
be ore a w.ver may be granted. Applicants that certify to the Administrator that they" o
k.ovvn or suspected industrial sources of toxic pollutants or pesticides are not requ ired tolv
an industrial pretreatment program.
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TTIH5 Urban area pretreatment requirement [40 CFR 125.65]
serving a population of 50,000 or greater must respond
a Provide data on all toxic pollutants introduced into the treatment works
from industrial sources (categorical and noncategoiical).
b. Note whether applicable pretreatment requirements are in effect for each
toxic pollutant. Are the industrial sources infrodwng such tone
pollutants in compliance with all ^^'ntnia^"
these pretreatment requirements being enforced? [40 CFR
c If applicable pretreatment requirements do not exist for each toxic
pollutant in the POTW effluent introduced by industrial sources,
. provide a description and a schedule for your development, md
implementation of applicable pretreatment requirements [40 CFR
125.65(c)], or
• . describe how you propose to demonstrate Secondary removal
equivalencyforeachofthosetoxicpollutant^includtngaschedule^
compliance, by using a secondary treatment pilot plant. [40 CFR
125.65(d)]
*** Dischargers serving a population of 50,000 or more must respond.
Applicants must conduct an industrial waste survey, as described in 40 CFR 403.8(0®.
as thesis for characterizing industrial sources by ^try type (SIC cod^ *pes and
concentrations of toxic pollutants in discharge(s), wastewater flow to the PO1W, and other
"::m^^
be identified separately as categorical or noncategorical industries., It is hkely that this
Lfo^ln has lady been developed as part of the applicant's approved industnal pretreatment
program under 40 CFR Part 403. j
Once the toxic pollutants being introduced by industrial sources and those sources have
been idenrified, the applicant can choose between two methods to comply wrth the urban area
The applicant must address each toxic poUutant mtroduced by
me pUcant would demonstrate that it has in effect applicable pretreatmen,
*th L poUu^n, discharged to the POTW by industry K125.65(c)]. I. me second method,
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[uivalency
— ' "JTJC—~» TTUUJ.U utsxuvsuauaic uicti me
treatment process (including any existing pretreatment) removes at least the same
amount of that toxic pollutant as would have been removed by secondary treatment if there were
no pretreatment for that toxic pollutant [§125.65(d)]. Appendix E provides guidance for
conducting the above demonstrations for compliance with urban area pretreatment requirements
A summary of these methods is provided below. Cements.
Applicable Pretreatment Requirement Approach
General Approach. Under §125.65(b)(l)(i), an applicant must have in effect appUcable
pretreatment requirements for each toxic pollutant discharged to the POTW from one or more
mdustnal users Applicable pretreatmen, requirements may take the form of (1) categorical
standards; (2) ,ocal limits (numeric and/or narrative), or a combination of (!) and (2*^
momtorto ^L^^^ ** '^ ""*" "" n°' DeCeSSaiy for a toxic P0'1"""". ™™1
pllMrnWtvrnao?rntPraCtiCeS PlaOS OMPS)' "**'^^P^^MPsXrdoaer
xi/u • j . i - J.IIIUL iur d. spcciric toxic pollutont
When an mdustnal discharger is subject to both a categorical standard (1) and a numeric local
limit (2) for a specific toxic pollutant, the more stringent of the two limits applies.
Categorical standards (see 40 CFR 403.6) are nationally uniform, technology-based limits
ped for specific industries and for specific toxic pollutants All '
f with categorical standards, even if they discharge to a POTW 'th ^ ""^
approved local pretreatment program. By contrast, local limits are developed by the POW
among other purposes, to prevent interference with the treatment works or pass-through of toxic'
pollutants, as required by 40 CFR 403.5(b). "gn or TOXIC
and .„ f ans
a D±1 ^ 7 POUntantS- ^ ^ 10Cal "«*• -* «»*«-*- •»*» ""dress
a pamcu ar pollu^t for a specific industry, the more sftagent requirement applies. Furthermore
oca, touts for specific toxic pollutants found in the POTW waste strej can apply ^
ategonca, and noncategorica, indusMes when the toxic poUu^nts cannot be en Jy Lb
to categoncal mdustries and/or when categorical standards alone are no, sufficient to satisfy
requirements of 40 CFR Part 403. ^
- S" 4° CER 403'5> ^ re^temenB ^^ "y a POTW based on local
and umque requuements at me POTW. These limits are primarily intended to protect
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the treatment plant from industrial discharges that could interfere with PCXfW treatment processes
or pass through the treatment plant to receiving waters and adversely impact water quality or the
environment. Local limits are also designed to prevent sludge contamination and protect workers
at the treatment plant.
Under the applicable pretreatment requirement approach, the applicant must address each
toxic pollutant introduced by industry. However, the POTW need not develop a specific numeric
local limit that applies to each industrial source of each toxic pollutant. After conducting a local
limit analysis, the POTW may apportion the allocation of the numeric local limit (if any) to any
number of industrial sources of the toxic pollutant (categorical and/or noncategorical) that the
POTW deems appropriate, subject to approval of the applicable Regional office. Moreover, when
it is not appropriate or practical to develop and implement numeric local limits to prevent
pollutant pass-through or interference for a specific toxic pollutant, the EPA pretreatment program
has provided for narrative local limits (i.e., industrial management and best management
practices) as useful supplements to numeric limits. Narrative local limits Eire most appropriate
where management plans are needed to help control or eliminate chemical spills or leaks, slug
discharges, or the handling of hazardous or toxic materials from both categorical and
I
noncategorical industries.
For toxic pollutants for which the POTW determines that neither numeric nor narrative
local limits are necessary, a program of periodic POTW monitoring and annual technical review
of data on industrial discharges would be conducted by the POTW and, where appropriate, would
require industrial users to institute IMPs and other pollution prevention activities to control and
reduce the levels of those toxic pollutants for selected industries. For those toxic pollutants, the
POTW would report annually to EPA on the status of the need for development of local limits.
If such monitoring and technical review of data indicate that a local limit is needed, the POTW
would establish and implement a local limit.
1 . i
IMPs are intended to minimize the discharge of toxic pollutants to the sewer, or reduce
the impact of toxic pollutant discharges by avoiding short-term, high-concentration discharges.
IMPs can be applied to all classes of industrial users, e.g., major and minor industrial users.
Examples of appropriate uses of IMPs include control of chemical spills and slug discharges to
the POTW through formal chemical or waste management plans (including BMPs), solvent
management plans, batch discharge policies, waste recycling, and waste minimization. It would
also be appropriate to consider IMPs in cases where the POTW does not include biological
treatment processes, or provides less treatment, e.g., primary treatment, hi these cases, IMPs can
be tailored for industrial sources of toxic pollutants that might otherwise interfere with biological
treatment or would be degraded or removed through additional treatment.
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EPA's Guidance on the Development and Implementation of Local Discharge Limitations
Under the Pretreatment Program (U.S. EPA 1987h) provides various methods for calculating
numeric local limits. Applicants should consult the appropriate EPA Regional office for more
specific information regarding pretreatment programs and local limits development. The
following discussion is intended as a guidance framework for a process to demonstrate and
comply with the §125.65 urban area pretreatment requirements through the applicable
pretreatment requirement approach.
Maximum Allowable Headworks Loading (MAHL) Method. The predominant approach used
is a chemical-specific approach known as the maximum allowable headworks loading (MAHL)
method. This is accomplished pollutant by pollutant for each environmental criterion or plant
requirement, and the lowest or most limiting value for each pollutant serves as the basis for
allocation to industry and ultimate numeric local limits. As an example, steps of the maximum
allowable headworks loading method are summarized below, as the method might be applied for
purposes of meeting the urban area pretreatment requirements (i.e., applicable pretreatment
requirement in effect). Other approaches for establishing numeric local limits may also be
appropriate. Applicants should establish local limits programs in coordination with Regional
Administrators on a case-by-case basis. Appendix E provides additional information on the
MAHL approach and on alternative approaches.
Determine Pollutants of Concern-The applicant must address all toxic pollutants [40 CFR
401.15 and §125.65(b)(l)] that are identified as known or suspected to be discharged by industry
to the POTW. An initial screening of the known or suspected toxic pollutants may be performed
to select those likely to require numeric local limits as determined under the MAHL method.
For the remaining toxic pollutants, the POTW must evaluate the need to set narrative local limits
(i.e., industrial management and best management practices) to control and reduce levels of these
toxic pollutants from appropriate industrial sources. For toxic pollutants for which the POTW
determines that neither numeric nor narrative local limits are necessary, the POTW must conduct
periodic monitoring and annual review of industrial discharges to check the status of the need
for development of local limits.
Characterize Existing Loadings-An industrial waste survey must be conducted, as
previously discussed, using guidance provided by EPA (U.S. EPA 1983). The POTW must
characterize existing loadings to the treatment plant by conducting monitoring of all industrial
users. Either POTW monitoring data or self-monitoring data are acceptable, and information
from the industrial waste survey may also be of use. The applicant should also characterize
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nonindustrial sources of toxic pollutants such as hauled wastes and domestic/background sources.
The applicant must conduct sufficient monitoring at the treatment plant to adequately characterize
influent, effluent, and sludge loadings of toxic pollutants. Monitoring of the treatment plant
influent, effluent, and sludge should represent a minimum of 5 consecutive days to capture the
typical short-term range and variability in the wastewater composition. Preferably, in addition,
monitoring should include data for at least 1 day per month over at least 1 year for metals and
other inorganic pollutants and 1 day of sampling per year for all other toxic pollutants. The
method for analysis of a toxic pollutant should be selected according to the type of pollutant to
be analyzed (i.e., grab samples over 24 hours for volatile organic compounds, total recoverable
phenolic compounds, and cyanide and flow-proportioned 24-hour composite samples for all other
toxic pollutants). Appendix E provides additional guidance on development of a toxic pollutant
monitoring program.
Determine Applicable Environmental Criteria-Environmental criteria generally include
NPDES permit limits, water quality standards or criteria, sludge disposal requirements, and unit
process inhibition values. 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. ,
Calculate Maximum Headworks Loadings-If using the MAHL approach, the applicant
calculates 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. All calculations should be consistent with the
approach outlined in the EPA guidance manual (U.S. EPA 1987h).
Calculate Allowable Industrial Loadings-If using the MAHL approach, the applicant
incorporates a safety factor (range of 10 to 30 percent) and discounts the value for
domestic/background loadings in order to determine the maximum allowable allocation available
for industrial users.
Allocate Allowable Industrial Loadings-The method chosen to allocate the allowable
industrial loading depends on the number and types of industrial users and the method of
application (permits, contract, or sewer use ordinance) employed by the E'OTW. Where the
current loading of a toxic pollutant exceeds the maximum allowable headworks loading, the
applicant must establish a numeric local limit to reduce loadings to within the range of the
maximum allowable headworks loading. Under the applicable pretreaitment requirement
approach, the POTW must address each toxic pollutant introduced by industiy. The POTW may
allocate the allowable industrial loading among any number of industrial sources of the toxic
j
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pollutant (categorical and/or noncategorical) that the POTW deems appropriate, subject to the
approval of EPA. Where the current loading is below the maximum allowable headworks
loading, the applicant is encouraged, but not required, to set industrial discharge limits at current
loadings to provide a safety factor. Numeric local limits could be allocated, for example,
according to the following classification scheme developed under the industrial waste survey.
For major or significant industries, the POTW could set specific effluent limitations (categorical
standards, numeric local limits, or both). For minor industries, the POTW may choose to set
numeric local limits when these industries as a group represent a significant source of toxic
pollutants to the POTW; otherwise, the POTW could evaluate the need to set narrative local
limits for appropriate industries (i.e., industrial management and best management practices) to
control and reduce levels of toxic pollutants. Examples of industrial management practices
include waste recycling, solvent management plans, batch discharge policies, and other "good
housekeeping" practices. Narrative local limits may also be implemented in conjunction with
numeric local limits for the same industry, if deemed appropriate. 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 mechanism.
Ongoing Review/Revision of Local Limits and Screening Pollutants of Concern. Local limits
should be reviewed and revised on a periodic basis to reflect changes in conditions or
assumptions. Conditions that might require that local limits be revised include, but are not
limited to, changes in environmental criteria, changes in the industrial users, availability of
additional monitoring data, changes in plant processes, and changes in POTW capacity or
configuration.
Annual monitoring should be conducted by the POTW as described above and in
Appendix E. The results of the monitoring and data review must be made available in the annual
report required under 40 CFR 403.12. If the applicant determines, based on results of annual
monitoring of the POTW influent/effluent/sludge and/or technical review of data on discharges
from industrial sources (also updated annually), that the level of a toxic pollutant is expected to
exceed the maximum allowable level determined through the local limits analysis, the applicant
should establish a new numeric local limit and modify the individual control mechanism or sewer
use ordinance, as appropriate, to implement the new local limit. Furthermore, the applicant should
update the initial screening of toxic pollutants based on results of the same technical review to
determine the need for inclusion of any new toxic pollutants/industries in the local limits analysis
(either numeric or narrative).
Ongoing Analysis of Other Toxic Pollutants Not Addressed by Local Limits. For toxic pollutants
for which the POTW determines that neither numeric nor narrative local limits are necessary
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(e.g., not pollutants of concern, insignificant industrial contribution), a program of periodic
POTW monitoring (as described above and in Appendix E) and annual technical review of data
on industrial sources should be conducted. Where appropriate, the POTW should require
industrial users to institute IMPs and other pollution prevention activities to control and reduce
the levels of these toxic pollutants for selected industries. For these toxic pollutants, the POTW
should report annually to EPA on the status of the need for development of local limits (e.g.,
whether these toxics are now pollutants of concern; whether IMPs are needed for additional
industries, etc.). If such monitoring and technical review of data indicate that a local limit is
needed, the POTW would establish and implement a local limit.
Secondary Removal Equivalency Approach
!
Alternatively, an applicant may demonstrate that its own treatment processes, in
combination with existing pretreatment by industrial dischargers, achieves "secondary removal
equivalency." Applicants are required to make this demonstration when they cannot show that
a known or suspected toxic pollutant introduced by an industrial discharger has an "applicable
pretreatment requirement" in effect as defined in §125.65(c) and discussed above. Although
secondary treatment removes conventional pollutants, a certain amount of toxic pollutants in the
influent is incidentally removed during the process. In the absence of an applicable pretreatment
requirement in effect for a toxic pollutant, WQA section 303(c) requires that a section 301(h)
discharger remove at least that same amount of a toxic pollutant, through a combination of
industrial pretreatment and 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 program
existed for that pollutant.
To demonstrate secondary removal equivalency, an applicant would need to use a
secondary treatment pilot plant. By diverting part of its primary effluent (secondary influent) to
the pilot plant, the applicant would empirically determine the increment^ amount of each toxic
pollutant that would be removed from the primary effluent (secondary influent) if secondary
treatment were applied. Having determined the amount of each toxic pollutant removed, the
applicant would then demonstrate that its existing less-than-secondary treatment plus industrial
pretreatment removes at least the same amount of each toxic pollutant as did the secondary
treatment pilot plant (including removals in the primary effluent) without any industrial
pretreatment.
In cases where an applicant already has an ongoing industrial pretreatment program that
addresses categorical industries but not all toxic pollutants discharged to the POTW .from
categorical and noncategorical industries, the applicant may choose to perform the empirical
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secondary removal equivalency demonstration using influent that has been subject to that existing
industrial pretreatment. (The applicant is not expected, in most cases, to be able to provide
"unpretreated" industrial wastewaters to perform the empirical demonstration.) Such a
demonstration may then be conservative because it may overstate the amount of toxic pollutant
that would be removed by applying only primary and secondary treatment. Because it would be
conservative, applicants are permitted (but not required) to make the secondary equivalency
demonstration using effluent that has undergone partial industrial pretreatment.
Effluent limits (concentration values and/or flow-corrected mass loading values) will be
developed based on data from the secondary removal equivalency demonstration when these
values are more stringent than effluent limits based on state water quality standards or water
quality criteria, or required to ensure that all applicable environmental protection criteria are met.
Once the effluent limits are established, the applicant may either develop local limits (as
described above) or perform additional treatment at the POTW, or combine the two to achieve
the permit limit.
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DETERMINATIONS OF COMPLIANCE WITH SECTION 301(h)
MODIFIED PERMIT CONDITIONS AND 301(h) CRITERIA
PERMIT CONDITIONS
POTWs that hold section 301(h) modified permits must comply with section 301(h)
criteria and regulations, as well as all applicable state water quality standards, state and federal
laws, regulations, and Executive orders. General guidance is presented below for assessing the
effects of POTW discharges into the marine environment, including water quality, physical, and
biological evaluations. Question III.B.7 of the Applicant Questionnaire places additional
requirements to meet federal water quality criteria, as well as applicable state standards
[§125.62(a)(l)] on all section 301(h) dischargers. These requirements 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 parameters, but do not create a fundamentally different, or new, class
of standards, criteria, or requirements that must be met. Therefore, the general guidance provided
below includes information relevant to determinations of compliance with the federal water
quality criteria and applicable state standards. Guidance is also presented on the evaluation of
biological monitoring data collected to identify biological impacts that may occur as a result of
a discharge. Such biological monitoring efforts should be designed to identify potential problems
early, as well as to demonstrate compliance with 301(h) requirements.
The first step in evaluating effects of 301(h) discharges on water quality, especially when
applicants are seeking renewal of a 301 (h) modified permit, is to compare the data to be
submitted for the renewal with the data collection requirements specified in the existing section
301(h) modified permit. The following two key questions should be addressed:
• Are all physical, chemical, and biological parameters required by the section
301 (h) modified permit measured? |
I
• Is each required parameter measured at the specified locations and at the
specified frequency?
If either question cannot be answered affirmatively, the applicant could be considered in
noncompliance with the terms of the existing section 301 (h) modified permit. In cases of
apparent noncompliance, the applications for reissuance of the modified permit may be denied
without further examination of the monitoring data.
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Assuming that all the appropriate data are available, the second step is to evaluate the
technical merit and interpretation of the data. Three major areas should be considered when
preparing assessments of the data:
• Data quality;
• Execution of the analyses; and
• Interpretation of the analytical results.
Applicants should provide sufficient information to document that data quality is high, analyses
are properly executed, and data interpretation is reasonable. Procedures for proper data collection
are found in guidance presented in U:S. EPA (1982a, 1982c) and guidance given under the
appropriate questions in the Applicant Questionnaire (especially Questions III.F.1 and III.F.2).
Of critical importance to the collection of data for any parameter is whether appropriate field and
laboratory methods are used to collect the data and whether appropriate QA/QC procedures are
followed. Data are of little value if they are collected using inappropriate methods or if the col-
lection process is so poorly executed that their accuracy is hi doubt. Refer to U.S. EPA (1987c)
for additional QA/QC guidance.
As is true for data collection methods, data analysis methods vary greatly in terms of the
various types of physical, chemical, and biological parameters. Applicants are referred to the
aforementioned documents for guidance on evaluating data analysis methods. The following
questions should be kept in mind during the presentation of the data analyses:
• Are values for each parameter reported in 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, applicants should indicate how the
data and the results of analyses of those data support the applicant's conclusions concerning
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whether the existing or proposed discharge contributes to adverse impacts on the receiving water
or biota.
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DETERMINATIONS OF COMPLIANCE WITH SECTION 301(h) CRITERIA
When monitoring data indicate that impacts to water quality, sediment quality, or biota
are occurring, it will be necessary to determine whether such impacts are adverse. Many physical
and chemical criteria (e.g., dissolved oxygen concentrations, concentrations of toxic pollutants
in the water column after initial dilution) are quantitative. Determinations; of water quality values
are reasonably straightforward and rely primarily on the results of well-documented mathematical
calculations s Provided that the physical and chemical data were properly collected and analyzed,
the resulting values for each physical and chemical parameter can be compared with applicable
section 301(h) criteria, state standards, and federal water quality criteria. Results of such com-
parisons can be used to determine the presence of an adverse impact.
The initial dilution is a critical parameter relative to compliance with water quality
standards and 304(a)(l) water quality criteria. The magnitude of initial dilution achieved depends
on ambient water density gradients and diffuser design. The ZID size is important to determine
compliance with water quality and biological criteria. Methods for determining the size of the
ZID can be found in discussions of Questions III.A.I and III.A.2 and Appendix A.
The transport of diluted effluent beyond the ZID is also important to determine whether
a discharge will comply with water quality standards. In addition, dischargers—particularly those
to estuaries or partially enclosed (e.g., restricted flow) areas—may need to demonstrate that
reentrainment or accumulation of effluent will not result in violations of applicable water quality
standards. , l
I
When the values of one or more physical or chemical parameters consistently 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 water. Ap-
plicants that propose improvements to outfall or treatment systems will msed to predict the values
of parameters relevant to 301(h) criteria that can be expected following implementation of the
proposed improvements.
; ,.-• The assessment of adverse biological effects in the section 301 (la) process involves
assessment of whether a balanced indigenous population 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 integral part of the applicant's biological assessment, it is important to
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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 reproducing unit of a single species, but rather
all biological communities existing in 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 POTW discharge [§125.58(y)].
A BIP is defined in the section 301(h) regulations [§125.58(f)] as "an ecological
community that: (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 in 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 reestablishment of communities is
included because of its relevance to proposed, 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/temporal distributions; growth and reproduction of populations; disease
frequency; trophic structure and productivity patterns; presence or absence of certain indicator
species; bioaccumulation 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 EPA has determined
that these are observable characteristics of natural communities existing in the absence of human
disturbance, a comparative strategy is found throughout the section 301(h) regulations. Biological
parameters of concern near the discharge should be compared to the range of natural variability
found in comparable, but unpolluted, habitats. The section 301(h) applicant should compare
biological conditions at reference (control) sites with conditions hi areas of potential discharge
impact within and beyond the ZED.
While biological criteria are not defined hi the same straightforward, quantitative way as
physical and chemical criteria, some extreme adverse impacts are defined specifically in the
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301 (h) regulations and are known endpoints in a spectrum of possible biological conditions that
might 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; !
i
I
• Presence of disease epicenters;
• Stimulation of phytoplankton blooms that have adverse impacts beyond the
ZID; and
• Conditions that result in mass mortalities of fish and in vertebrates.
i , :
In addition, other biological effects on a particular marine community that result in substantial
secondary effects on another community, or result in a potential for adverse effects on humans,
would normally be. considered adverse. For example, within and beyond the ZID, adverse
impacts include, but are not limited to, the following:
• Damage to distinctive habitats of limited distribution;
I
• Creation of disease epicenters in commercially or recreationally important
species;
• Contamination of fishery resources by pathogenic microorganisms or their
indicators;
• Mass mortalities of fish or shellfish;
- i
• Bioaccumulation of toxic substances in fish and shellfish at levels injurious
to the marine organisms or humans; or
i,
i
• Substantially decreased abundance of commercially or recreationally
important species.
Applications that propose improvements to eliminate any of these adverse impacts may be
considered. Because all of these impacts are considered extremely adverse, however, it would
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be difficult to demonstrate that a balanced indigenous population will become reestablished
following improvements to the treatment plant or outfall.
Many biological impact assessments that are necessary under 301(h) regulations require
determinations of degrees of impact relative to unstressed conditions. 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 impact
gradients. Quantitative comparisons between reference sites and potentially impacted areas may
be made using various types of biological data [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.D.1 above. However, no quantitative
biological criteria have been established. Therefore, changes in, or differences between,
biological communities require careful consideration of the types of responses that are manifested
by the pollutant stress, as well as their spatial extent and magnitude.
Three approaches have been used in the 301(h) program to assess the degree of change
in the biota (and associated receiving water). The first is to determine whether the observed
change represents a reduction in the area! extent or health of a community or ecosystem. This
approach has most often been used in cases where a change in major taxa that characterize the
community greatly modifies the environment, thereby creating habitat for other, less desirable
species. Primary examples include distinctive habitats of limited distribution, such as kelp
communities, coral reefs, and seagrass beds. Because most of the taxa in 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 in destruction of the community.
One assemblage of organisms is not replaced by another in which the species belong to the same,
or similar, major taxonomic groups, and in which the new taxa are able to tolerate, and in many
cases thrive in, the modified environment. In cases where a community or ecosystem is 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 is an adverse impact.
In communities where pollutant impacts result in changes in species composition and
abundance, but not in the destruction of the habitat, it is more difficult to assess changes.
However, two approaches to the problem have been used in the past. 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) affects, or has the potential to affect, all of the major elements
of the ecosystem. The second approach is a corollary of the first. It assumes that a major
change in the structure (i.e., species composition and abundance) of a community indicates that
change in the function of that community has occurred, even if a change in function cannot be
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demonstrated. A change in the structure of a community is usually much easier to document than
is a change in the function of a community.
Benthic infauna are used in the following example to demonstrate how the functional and
structural approaches may be implemented to demonstrate compliance with section 301(h)
regulatory requirements. 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. Total abundance does not increase significantly until the "ecotone
point" is approached. In the "transition zone," there is simply an enhancement of the community
that is typical of the biogeographic region, with the addition of a few new species. There are no
major functional or structural changes. If there are no major impacts associated with other
aspects of the benthic hifauna (e.g., bioaccumulation of toxic substances), the impact to benthic
infauna may or may not be evidence of the presence of a BIP.
At and beyond the "peak of opportunists" as shown in Figure 3, Pearson and Rosenberg
(1978) document that the number of species and abundance of the bentbic infauna change
substantially. The fauna becomes dominated by a few opportunistic or pollution-tolerant species
whose abundance increases 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. 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 is 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 invertebrates that prey on benthic infauna have been recorded in the scientific
literature. Hence, there is 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.
The concepts of spatial extent of the discharge-related biological and intercommunity
effects are important in a BIP demonstration. Therefore, if differences between the ZID
boundary communities and control communities are observed, the assessment of a BIP should
include a characterization of the extent and possible interrelationship of effects beyond the ZID.
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PO
— s
Increasing Organic Input
S - Spocies numbers
A » Total abundance
B » Total biomass
PO ». Peak of opportunists
E - Ecotone point
TR » Transition zone
Figure 3.
Generalized depiction of changes in species numbers, total abundances, and total biomass along
a gradient of organic enrichment (Pearson and Rosenberg 1978).
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Special emphasis should be placed on any predicted changes in the areal extent of discharge-
related effects following discharge improvements or alterations. Further, in addition to assessing
benthic communities and demersal fishes, the applicant should consider the need to assess other
discharge-related effects on other biological communities. In assessing tliis need, the applicant
should consider the nature of the discharge (e.g., flow, location, solids emission rates, and
concentrations of discharged pollutants, including toxic substances) and characteristics of the
receiving water body (e.g., circulation patterns, productivity, and trophic relationships). For
example, if a discharge is located close to shore or there is significant onshore transport, the
assessment of effects on intertidal or subtidal macroalgae may be another important component
of the BIP demonstration. Similarly, if a discharge is located in an estuary or enclosed
embayment where phytoplankton blooms may be stimulated by nutrient inputs, the assessment
of plankton communities may be appropriate as part of the applicant's demonstration.
I.
If an existing discharge may be causing an adverse impact to the biota or if the proposed
discharge has the potential to cause an adverse impact to the biota or would result in non-
compliance with section 301 (h) criteria, then the applicant should perform a detailed biological
demonstration to support approval of the application. The Region could require detailed
biological demonstrations to be performed to validate the acceptability of proposed improvements.
It is the applicant's responsibility to allow sufficient time to design and execute appropriate
studies.
EVALUATIONS OF PREDICTED CONDITIONS AND PREDICTED CONTINUED
COMPLIANCE
Under the original 301(h) regulations, POTWs were allowed to apply for first-time section
301(h) modified permits based on current, improved, or altered discharges. A "current discharge"
is defined in §125.58(h) 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
procedures, or controls on the introduction of pollutants into the treatment system [§125.58(i)].
An "altered discharge" is defined as any discharge other than a current discharge or an improved
discharge as defined in §125.58(b).
For improved and altered discharges, applicants were required to predict conditions that
would occur in the receiving water 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 in part on
131
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predictions of conditions that would occur after proposed improvements or alterations were
implemented, prior to reissuance of a permit it is necessary to evaluate whether the predicted con-
ditions have been realized. Because monitoring data collected during the term of the existing
permit should be used in support of the application for permit reissuance, evaluations of the
applicant's original predictions of compliance are not unlike other determinations of compliance.
As was the case for original section 301(h) applications, applications for reissuance of
section 301(h) modified permits may propose improved levels of sewage treatment, either in
response to comments by EPA or at the permittee's initiative. Applications for permit reissuance
that are based on altered discharges are also allowed when downgrading of effluent quality is
attributable entirely to population growth and/or industrial growth within the service area.
Applicants that propose improved or altered discharges must also comply with the appropriate
state's antidegradation requirements. Proposals for improved and altered discharges require that
the permittee predict the physical, chemical, and biological conditions that will occur in the
receiving water as a result of the proposed discharge. In such cases [as in the original sec-
tion 301 (h) applications], it will be necessary to evaluate whether the permittee's predictions are
reasonable and whether the predicted conditions would satisfy section 301 (h) criteria and
regulations.
Applicants should consider the following when preparing applications with predictions
based on improved or altered discharges:
• Appropriateness of the models used to generate the predictions (see
discussion in Appendix A);
• Data quality;
» Execution of the analyses; and
• Interpretation of the analytical results.
It is 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 may
be questionable.
To predict conditions that might occur as a result of a proposed discharge, applicants may
compare attributes of the proposed discharge (e.g., volume and composition) and receiving water
with conditions near other outfalls that discharge effluent of similar volume and composition and
in similar receiving waters. The validity of such comparisons rests on the similarity of the
132
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discharges and the similarity of the receiving waters. Substantial differences in the diffuser
design, 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 parameters.
For physical and chemical parameters, 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 is very tenuous unless the response patterns of the biota within the biogeographic
region are well known.
Similarity of the receiving waters is also critical to such comparisons. It is important that
both discharges be located within the same biogeographic zone because responses to pollutants
vary among species. Species in one biogeographic zone may respond somewhat differently to
a given pollutant than do species in another biogeographic zone. For that reason, it may be
possible to predict the general types of changes that might 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 unless both discharges are in the same biogeographic zone. It is also important that the
physical and chemical characteristics of both receiving waters be similar, For example,
discharges into open coastal areas should not be compared with discharges into embayments.
The more similar the two receiving waters are, the more reliable the applicant's predictions may
be assumed to be.
Applicants may also use water quality models to predict impacts of the proposed
discharge. Such models would be especially, helpful for physical and chemical parameters (e.g.,
deposition of suspended solids in the receiving water, 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 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.
133
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McDermott-Ehrlich, DJ., MJ. Sherwood, T.C. Heesen, D.R. Young, and AJ. Mearns. 1977
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McDermott-Ehrlich, DJ D.R. Young, and T.C. Heesen. 1978. DDT and PCB in flatfish around
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"CAFE-2" - a two-layer finite element circulation model. TR No. 220. Massachusetts Institute
of Technology, R.M. Parsons Laboratory for Water Resources and Hydrodynamics, Department
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Pearson, T.H., and R. Rosenberg. 1978. Macrobenthic succession in relation to organic
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Rand, GM., and S.R. Petrocelli. 1985. Fundamentals of aquatic toxicology. Hemisphere
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Shene YP andHL Butler. 1982. A three-dimensional numerical model of coastal, estuarine
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SWmm,W., and J.J. Morgan. 1981. Aquatic chemistry. John Wiley and Sons, Inc., New York.
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to marine waters. EPA-430/9-82-010. U.S. Environmental Protection Agency, Washington, DC.
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waters; final rule. U.S. Environmental Protection Agency, Washington, DC. Federal Register
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U S EPA 1983 Guidance manual for POTW pretreatment program development. U.S.
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tstuanne Protection, Manne Operations Division, Washington, DC. ;
U.S. EPA. 1985b. Bioaccumulation monitoring guidance: 2. Selection of target species and
«Tn™ fvTm ^f*Umulation data. 2 vols. EPA 430/9-86-005 (Vol. I) and EPA 430/9-
86-006 (Vol II). U.S. Environmental Protection Agency, Office of Marine and Estuarine
Protection, Marine Operations Division, Washington, DC.
' • , i
U.S EPA^1985c Bioaccumulation monitoring guidance: 3. Recommended analytical detection
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bstuanne Protection, Marine Operations Division, Washington, DC.
U.S. EPA. 1985d. Bioaccumulation monitoring guidance: 4. Analytical methods for U.S. EPA
?m£^n ™?^rtSc^d 3°1(h) Pesticides in tissues fr°m estuarine and marine organisms EPA-
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Manne Operations Division, Washington, DC.
i • " ' i -
U.S. EPA. 1985* Summary of U.S. EPA-approved methods, standard methods, and other
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Agency, Office of Manne and Estuarine Protection, Marine Operations Division, Washington,
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i
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!fSSUance Suidance document for small dischargers. EPA-
DC Protection ^ency, Office of Marine and Estuarine Protection,
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U.S. EPA. 1987a. Evaluation of survey positioning methods for nearshore and estuarine waters.
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Protection, Marine Operations Division, Washington, DC.
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Estuarine Protection, Marine Operations Division, Washington, DC.
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monitoring programs: Guidance on field and laboratory methods. EPA-430/9-86-004. U.S.
Environmental Protection Agency, Office of Marine and Estuarine Protection, Marine Operations
Division, Washington, DC.
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Environmental Protection Agency, Office of Marine and Estuarine Protection, Marine Operations
Division, Washington, DC.
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430/9-86-004. U.S. Environmental Protection Agency, Office of Marine and Estuarine Protection,
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Water Enforcement and Permits, Washington, DC.
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I
Word, J,Q. 1980. Classification of benthic invertebrates into infaunal trophic index feeding
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,|
Young, D.R., T.C. Heesen, and D.J. McDermott. 1976b. An offshore biomonitoring system for
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APPENDIX A
PHYSICAL ASSESSMENT
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PHYSICAL ASSESSMENT
The primary purpose 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 sets of procedures:
I
• 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 the 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-hour 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 Mullenhoff et al. (1985a) the critical (i.e., minimum)
initial dilutions must be calculated on the basis of the highest 2- to 3-hour 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.
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 the
ports, 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. Koh
(1973) provides a useful method for computing riser discharge coefficients. (Note, however, that
the summary of this method in Fischer et al. (1979) contains errors.) Head loss determinations
A-l
-------
for contractions, expansions, and bends can be found in standard engineering and hydraulics texts
(e.g., 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 flows lower than the minimum, not
all of the ports flow fully 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 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 within the group. The group initial dilutions and trapping depths can then be flow-
rate-averaged as a group 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 an essentially vertical flow to an essentially horizontal flow dominated
by ambient oceanographic conditions.
Adequate initial dilution is necessary to ensure 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;
A-2
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Ambient current speed and direction;
Diffuser characteristics:
Port sizes,
Port spacing,
Port orientation, and
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 are available from EPA
(Muellenhoff et al. 1985a, 1985b). Characteristics 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.
' * - • I
• UDKHDEN - Analyzes a multiport, positively buoyant plume in a linearly
stratified flowing receiving water.
A-3
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TABLE A-l. SUMMARY OF PLUME MODEL CHARACTERISTICS
Model
Name
UPLUME
UOUTPLM
UDKHPLM
UMERGE
ULINE
Current
Speed
No
Yes
Yes
Yes
Yes
Current
Dkection 0a
90°
45° < 0 < 135°
90°
0 < 0 < 180°
Port Type
Single
Single
Multiple
Multiple
Line
Density Profile
Type
Arbitrary
Arbitrary
Arbitrary
Arbitrary
Arbitrary
Source- From Table 1 of Muellenhoff et al. (1985a). . _„
Sent flowing perpendicular to the diffuser axis has current direction 0 = 90°. The widest range of poss.ble angles ,s 0 to 180 .
• 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 observations 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);
Hinwo'od and Wallis (1985); Hirst (1971a, 1971b); 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, 1989b, 1989c); 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
A-4
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quality computations. Other types of initial dilutions, such as centerline 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-5
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REFERENCES
Abraham, G. 1963. Jet diffusion in stagnant ambient fluid. Delft Hydraulics Publication No.
29. Delft, Netherlands.
Abraham G 1971. The flow of round buoyant jets issuing vertically into ambient fluid flowing
in a horizontal direction. Delft Hydraulics Publication No. 81. Delft, Netherlands.
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.
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. California Institute of Technology, W.M. Keck Laboratory of Hydraulics and Water
Resources, Pasadena, CA.
Daugherty, R.L., and J.B. Franzini. 1977. Fluid mechanics with engineering applications. 7th
ed. McGraw-Hill Book Company, New York, NY.
Davis, L.R. 1975. Analysis of multiple cell mechanical draft cooling towers. EPA-660/3-75-
039. U.S. Environmental Protection Agency, Environmental 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, 6-11 August 1978, Toronto,
Canada.
Fan L H 1967 Turbulent buoyant jets into stratified and flowing ambient fluids. Report No.
KH-R-15. California Institute of Technology, W.M. Keck Laboratory of Hydraulics and Water
Resources, Pasadena, CA.
A-6
-------
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.
Grace, R. 1978. Marine outfall systems planning, design, and construction. Prentice-Hall, Inc.,
Englewood Cliffs, NJ. !
i
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. 197la. Analysis of round, turbulent, buoyant jets discharged into flowing stratified
ambients. Report No. ORNL-4685. U.S. Atomic Energy Commission, Oak Ridge National
Laboratory, Oak Ridge, TN. - \
Hirst, E.A. 1971b. Analysis of buoyant jets within the zone of flow establishment. Report No.
ORNL-TM-3470. U.S. Atomic Energy Commission, Oak Ridge National Laboratory, Oak Ridge,
TN. ' ,i
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 investigation of deep
submerged multiple buoyant jets. EPA-600/3-76-001. U.S. Environmental Protection Agency,
Environmental Research Laboratory, Corvallis, OR.
t '
Koh,R.CXY. 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.
• ''.-.'.. ' i. •
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. Proc. of the Royal Society of London, Vol. A234, pp. 1-
23.
Muellenhoff, W.P., A.M. Soldate, Jr., DJ. Baumgartner, M.D. Schuldt, L.R. Davis, and W.E.
Frick. 1985a. Initial mixing characteristics of municipal ocean discharges. Vol. I. Procedures
and applications. EPA-600/3-85-073a. U.S. Environmental Protection Agency, Narragansett, RL
A-7
-------
Muellenhoff, W.P., A.M. Soldate, Jr., DJ. Baumgartner, M.D. Schuldt, L.R. Davis, and W.E.
Frick. 1985b. Initial mixing characteristics of municipal ocean discharges. Vol. II. Computer
programs. EPA-600/3-85-073b. U.S. Environmental Protection Agency, Narragansett, RI.
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.
In Proceedings of a Specialty Conference on Conservation and Utilization of Water and Energy
Resources, pp. 218-225. American Society of Civil Engineers.
Roberts, P.J.W., W.H. Snyder, and DJ. Baumgartner. 1989a. Ocean outfalls. I: Submerged
wastefield formation. ASCE J. Hydraul. Eng. 115:1-25.
Roberts, P.J.W., W.H. Snyder, and DJ. Baumgartner. 1989b. Ocean outfalls. II: Spatial
evolution of submerged wastefield. ASCE J. Hydraul. Eng. 115:26-48.
Roberts, PJ.W., W.H. Snyder, and DJ. Baumgartner. 1989c. Ocean outfalls. Ill: Effect of
diffuser design on submerged wastefield. ASCE J. Hydraul. Eng. 115:49-70.
Rouse, H., C.S. Yih, and W.G. Humphreys. 1952. Gravitational convection from a boundary
source. Tellus 4:201-210.
Sotil, C.A. 1971. Computer program for slot buoyant jets into stratified ambient environments,.
Tech. Memo 71-2. California Institute of Technology, W.M. Keck Laboratory of Hydraulics and
Water Resources, Pasadena, CA.
Teeter, A.M., and DJ. 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-8
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APPENDIX B
WATER QUALITY ASSESSMENT
-------
-------
CONTENTS
. Page
FIGURES '...' • • • • • • • • • : • • B'iv
TABLES . .;::....-. • • • • • • B'v
INTRODUCTION 1 B-l
B-I.
SUSPENDED SOLIDS DEPOSITION B-2
SMALL DISCHARGER APPROACH B-2
LARGE DISCHARGER APPROACH • B-5
B-II. DISSOLVED OXYGEN CONCENTRATION FOLLOWING
INITIAL DILUTION • •
B-III. FARFIELD DISSOLVED OXYGEN DEPRESSION
B-14
B-20
B-21
B-IV.
SIMPLIFIED MATHEMATICAL MODELS
NUMERICAL MODELS B~32
EVALUATION OF FIELD DATA B-33
SEDIMENT OXYGEN DEMAND fi-35
B-V. SUSPENDED SOLIDS CONCENTRATION FOLLOWING
INITIAL DILUTION B-40
B-VI. EFFLUENT pH AFTER INITIAL DILUTION B-43
B-VII. LIGHT TRANSMITTANCE B'47
B-VIII. OTHER WATER QUALITY VARIABLES B-53
TOTAL DISSOLVED GASES B-53
CHLORINE RESIDUAL B-53
NUTRIENTS • \ B-54
COLEFORM BACTERIA B-55
REFERENCES
B-59
B-iii
-------
FIGURES
Number
B-l
B-2
B-3
B-4
B-5
jage
Projected relationships between suspended solid mass
emission, plume height-of-rise, sediment accumulation,
and dissolved oxygen depression for open coastal areas B-3
Projected relationships between suspended solid mass
emission, plume height-of-rise, sediment accumulation,
and dissolved oxygen depression for semi-enclosed
embayments and estuaries B_4
Example of predicted steady-state sediment accumulation
around a marine outfall 3.9
Dissolved oxygen deficit vs. travel, time for a submerged
wastefield B-26
Farfield dilution as a function of 12e0t/B2 - B-30
B-iv
-------
TABLES
Number
B-l Example tabulations of settleable organic components
by group and maximum settling distance by group ; B-10
!
B-2 Example tabulations of deposition rates and
accumulation rates by contour B-12
B-3 Typical IDOD values B-15
B-4 Dissolved oxygen saturation values B-19
i
•
B-5 Subsequent dilutions for various initial field
widths and travel times B-37
•
B-6 Selected background suspended solids concentrations B-41
i
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-51
B-v
-------
-------
INTRODUCTION
This appendix provides detailed guidance for responding to water quality-related questions
in the Applicant Questionnaire. Methods for predicting values of the following water quality
variables are presented: ,
1 •>.
* Suspended solids deposition;
• Dissolved oxygen concentration following initial dilution;
• Farfield dissolved oxygen depression;
• Sediment oxygen demand;
I.
• Suspended solids concentration following initial dilution;
Effluent pH after initial dilution;
Light transmittance; and
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 are 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, as 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.
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 U.S. EPA (1982a) were used to determine the mass emission rates
and heights-of-rise resulting in the sediment accumulation rates specified above. 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-year period.
B-2
-------
7000
8000
500O
V)
Q
S 4000
ik
o
UI
* 3000
(A
i
20OO
1000
i 10 12 14
HEIGHT OF RISE, nt
18 18 20
STEADY STATE SEDIMIHT ACCUMULATION LESS THAN 50f|/m2
00 DEPRESSION DUE T§ STEADY-STATE SEDIMEMT
DEMAND > O£ mg/l
Figure B-l. Projected relationships between suspended solid mass emission, plume height-of-rise, sediment
accumulation, and dissolved oxygen depression for open coastal areas (U.S. EPA 1982b).
B-3
-------
4000 r-
8 X) 12 14
HEIGHT OF RISE, m
18
\WVV\\ STEADY STATE SEDIMENT ACCUMULATION LESS THAN 25g/m2
DO DEPRESSION DUE TO STEADY-STATE SEDIMENT
DEMAND > O.2 mg/l
Figure *-z. ^Relationships between suspended solid mass emission, plume height-of-rise. sedimen
accnmnlat-nn, ^d ^^ oxygen depression for semi.enclosed einbayments ^ estiiaries (y.s.
B-4
-------
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, wMchever is larger,
should be used in the appropriate figure (Figure B-l or B-2),
LARGE DISCHARGER APPROACH
i
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 i
j
To predict seabed deposition rates gf suspended solids, the following information is
required:
• Suspended solids mass emission rate; ;
• Current speed and direction;
I
• Height-of-rise of the plume; and
B-5
-------
• Suspended solids settling velocity distribution.
The mass emission rate, M (kg/day), is:
where:
M = 86.4(5)
B-l
S = Suspended solids concentration, mg/L
Q = Volumetric flow rate, mVsec.
It is suggested that the applicant develop estimates of the suspended solids mass emission rate
for the season (90-day period) critical for seabed deposition and for a yearly period. If the
applicant anticipates that 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; and
• 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.
Plume-trapping levels representative of both the critical 90-day period and 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
B-6
-------
the seafloor should be determined using available receiving water density profiles. If large
numbers of profiles exist for each month (or oceanographic seasdn), then,the applicant can
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
can compute the plume height of rise for each profile and substitute the lowest height-of-rise as
the average. The monthly 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 oceanographic seasons), then
the applicant should substitute 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
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
Raw Sewage
5 percent have Vs > 1.0 cm/sec
20 percent have V, > 0.5 cm/sec
40 percent have Ys £ 0.1 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
i
settleable hi the ambient environment. ,'•'•.
Prediction of Deposition - |
Although a portion of the settled solids is inert, the organic fraction of the settled solids
is a primary concern. For purposes of this evaluation, composition of the waste discharge can
be assumed to be as follows:
B 80 percent organic and 20 percent inorganic for primary or advanced primary
effluent or
, i .
H 50 percent organic and 50 percent inorganic for raw sewage. ;
B-7
-------
Accumulation of solids 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 iri 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 that of Hendricks (1987), which has been used extensively offshore
of Palos Verdes Peninsula in the Southern California Bight, and that of Farley (U.S. EPA 1987),
which describes the Ocean Data Evaluation System (ODES) model DECAL. The model DECAL
is publicly available through EPA. A simple model is described herein. It can be used to obtain
estimates of sediment accumulation in a variety of environments. If its use predicts sediment
accumulations that lead to violations of state standards or federal criteria for receiving water
quality, an applicant may opt to try 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 current speeds in four directions (upcoast, downcoast, onshore, and offshore) appropriate
for an effluent wastefield at the plume height-of-rise. For the following sample calculations, the
diffuser was assumed to have a single point of discharge. Use of this assumption may'not
produce reasonable estimates of sediment accumulation if the diffuser is long. If the diffuser is
long, then estimates of the sediment accumulation from each diffuser port can be summed to
obtain an estimate for the entire diffuser. This sum is approximately the same as that obtained
from assuming that the sediment accumulation area is a ZID-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 single point of discharge, 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 B-l.
B-8
-------
0 2
CONTOURS IN FEET
Figure B-3. Examples of predicted steady-state sediment accumulation around a marine outfall.
B-9
-------
TABLE B-l. EXAMPLE TABULATIONS OF SETTLEABLE ORGANIC COMPONENTS
BY GROUP AND MAXIMUM SETTLING DISTANCE BY GROUP
Mass Emission Rate = MT
Organic Component = M0 =
0.8 MT for primary effluent
0.5 MT for raw effluent
Organic Component
Maximum Settling Distance from Outfall3
Velocity Group
Primary Effluent
5 (Vs = 0.1 cm/sec)
15 (Vs = 0.01 cm/sec)
10 (Vs = 0.006 cm/sec)
20 (Vs = 0.001 cm/sec)
Raw Sewage
10 (Vs = 1.0 cm/sec)
10 (Vs = 0.5 cm/sec)
20 (Vs = 0.1 cm/sec)
20 (Vs = 0.01 cm/sec)
25 (Vs = 0.001 cm/sec)
by Group
0.04 MT
0.12 MT
0.08 MT
0.16 MT
Sum = 0.40 MT
0.05 MT
0.05 MT
0.10 MT
0.10 MT
0.125 MT
Sum = 0.425 MT
Upcoast
Dl
D5
D9
DI3
RI
R5
R9
RIS
R,7
Downcoast
D2
D6
D10
D14
R2
R6
RIO
Rl4
RIS
Onshore
D3
D7
Dn
DIS
R3
R7
R,,
R,5
R19
Offshore
D4
D8
D12
D16
R4
R8
R12
Rl6
R20
* The distance D (or R) is calculated as: D (or R) =
where:
V, = Ambient velocity = 5 cm/sec upcoast and downcoast (default) and 3 cm/sec onshore and offshore
(default)
HT = Average trapping level of plume, measured above bottom
Vs = Appropriate settling velocity by group for primary or raw discharges
If the bottom slope is 5 percent or greater, D (or R) should be calculated as follows:
D =
tLiri
where:
S = Slope, m/m, positive if onshore, negative if offshore.
B-10
-------
With a sufficiently detailed map (e.g., a NOAA bathymetric chart), each point DI through
D16, or RI through R20, 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., D15 D2, D3, and D4). 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 can be created more accurately.
The deposition rates corresponding to each contour are determined as follows, First, the
deposition rate within each contour due to each individual settling velocity group is predicted,
as shown in Table B-2. This quantity is M/A;, 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., D15 D2, D3,
and D4) and is denoted in the table by fXD^DjD^). A planimeter is probably the most accurate
method of finding the area. Once the deposition rates by group have been found, the total
deposition rate can be calculated by summing all contributing disposition rates. For example, the
innermost contour receives contributions from all groups, while the outermost contour receives
a contribution from only 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;) can be predicted by including decay as follows:
f
i2) = —, at steady state
kd
B-2
St (Sim2) = - [1 - exp (-90 kd)l for 90 days
The f; are the deposition rates in units of g/m2/day, as contrasted to the units of g/rn2/yr in Table
B-2. The decay rate constant, kd, has a typical value of 0.01/day. For example, if the organic
deposition rate for annual conditions is 100 g/m2/yr, the steady-state accumulation is:
100 g/m2/yr x
lyr
X
1
365 days Q.Ol/day
= 27 gjm/
B-3
If the organic deposition rate for the critical 90-day period is 300 g/m2/yr, the 90-day
accumulation is:
B-ll
-------
C*
p
2
0
ri
>
a'
H
P§
O
S
1
o
3
'a.
s
p*
CO
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s
1
5
H
a
1
M
w
CQ
<
H
^
<3
^
o
. "3
"3
S
9
o
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at
i
O
S
^
; 1
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' 1
1
!i
0
o
P
1 1
w *-<
&?,
en
i— i
"•?!•»?
s^l^8
II .,
,,. 4-1
^ II • «
,-f -* t*-l
? ^ »
^m ^ ^ "
* 3 * <
1 1 1 ^
€ ^ •••
^
^ € 4 4
1 il|
BQ Q Q
^3- ^*s ^2?
< ^ i^j ' i^1 »^
^ ^ i^ ^ ^
pq ii ii ii ii
S •* O C3 O
CO
A2+N3/A3+N4/A4+N5/.
,+N3/A3+N4/A4+N5/A
t, >
^ 5
z; Z
sT ^
W'
»
>n ^^
•3 »
!i
? ^
-------
300 g/m2/yr x
lyr
365 days 0.01/day
x [1- exp (-90 x 0.01)] = 49 glm:
B-4
This example shows that input data for the 90-day and steady-state aiccumulations 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-13
-------
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 prbcess) 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:
DOf = DOa
DOa - IDOD - DO.
B-5
where:
DOf
DO,
DOC =
IDOD =
Final dissolved oxygen concentration of receiving water at the plume
trapping level, mg/L
Affected ambient dissolved oxygen concentration immediately upcurrent of
the diffuser averaged over the tidal period (12.5 hours) and from the diffuser
port depth to the trapping level, mg/L
Dissolved oxygen of effluent, mg/L
Immediate dissolved oxygen demand, mg/L
= 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 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
IDOD 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):
B-14
-------
TABLE B-3. TYPICAL IDOD VALUES
Treatment Level
Untreated or less
than primary
Primary
Advanced primary
Effluent
BOD5 (mg/L) Travel Time (min)a
5Q-1QQ
50-100
50-100
100-150
100-150
100-150
150-200
150-200
150-200
<50
<50
<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
I
10
15
20
2
3
4
1
3
4
' 5
'5
i 7
8
|
0
1
1
"Travel time should include the total travel time from the treatment plant through the difuser, including any land portion of the outfall.
Note: Information compiled from 301(h) applications.
Initial Dilution
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
IDOD (mg/L)
1
• 2
.5 >
10
20
At high initial dilutions, the IDOD contribution is small. Thus, the expense of laboratpry tests
may be unwarranted. If IDOD is to be determined experimentally, the procedures in Standard
Methods (American Public Health Association et al 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
B-15
-------
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 minutes after preparation. . .
The IDOD is calculated using the following equation:
IDOD =
B-6
where:
IDOD
DOD
DO,
M
Immediate dissolved oxygen demand, mg/L
Dissolved oxygen of dilution water (seawater), mg/L
Decimal fraction of dilution water used
Dissolved oxygen of effluent after incubation, mg/L
Decimal fraction of effluent used
Dissolved oxygen of mixture after 15 minutes, 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 during 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 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
B-16
-------
taput for ambient water quality instead of an average value, ft» should be noted.
.
conservative estimate.
ambient dissolved oxygen
concentration at the trapping depth (DO,).
(D0e - IDOD -
oxygen depression of the
wastefield relative ,o the .rapping depth, expressed in percent, is
AD02 = D0f - D0a =
- IDOD - Doa]
B-8
B-17
-------
The equation of Baumgartner (1981) for the p
percentage depression is:
(D0t - D0e -+ IDOD]
D0
x 100
B-9
oxygen saturaeion
B-18
-------
DISSOLVED OXYGEN SATURATION
Dissolved fr^tt Saturatian (ing
Salinity (ppt)
30 32
Temperature
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
20
~
12.8
12.5
12.1
11.8
11.5
11.3
11.0
10.7
10.5
10.2
10.0
9.6
9.5
9.3
9.1
8.9
8.7
8.6
8.4
8.2
8.1
7.9
7.8
7.7
7.6
7.5
7.4
7.2
7.2
7.1
7.1
-•i ••"
22
i
12.6
12.3
12.0
11.7
11.4
11.1
10.9
10.6
10.3
10.1
9.9
9.6
9.4
9.2
9.0
8.8
8.6
8.5
8,3
8.1
8.0
7.9
7.7
7.6
7.5
7.4
7.3
7.2
7.1
7.1
7.1
Z4
.1
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
— - — —
Z.U
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
i . "~*
• ii i HP.
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
.i.ii *•
• M -
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
S,2
g,l
7,9
7Q
.©
7,6
7J
7,4
7,3
7,2
7,1
1,1
7,0
6.9
6.9
6J
11.8 11.7 11-5
11.5 11.4 11-2
11.2 H.l 10-9
10.9 10.8 10.7
10.7 10.5 10.4
10.4 10.3 104
10.2 10.0 9.9
9.9 9.8 9.7
9.7 9.6 9.4
9.5 9.3 9.2.
9.2 9.1 9.0
9.0 8.9 8.8
g.8 8.7 8.6
8.7 8.5 8.4
8.5 8.4 8.3
8.3 8.2 8.1
8.1 8.0 8.0
8.0 7.9 7.8
7.8 7.7 7.6
7.6 7.6 7.5
7.6 7.5 7.4
7.5 7.4 . 7.3
7.4 7.3 7.2
7.3 7.2 7.1
7.2 7.1. 7.1
7.1 7.0 7.0
7.0 7.0 7.0
6.9 6.9 6.9
6.9 6.9 6.8
6.8 6.8 6.8
6.8 6,8 6.7
L. 1
B-19
-------
B-ln. FARHELD DISSOLVED OXYGEN DEPRESSION
dissolved oxygen
expression:
°" " """" '" eStoate
s eaaaat^ « »<= estimated osing the Mowing
where:
BOD, = BOD
B-10
BODf
BOD.
BOD. =
Final BOD5 concentration, mg/L
Affected ambient BOD5 concentration immediately
: depth to the trapping depth, mg/L
Effluent BOD5 concentration, mg/L
Initial dilution (flux-averaged).
BOD5 concentration by
of the effluent As a critical
should be used '
the
* "^ ""
'° esttaate farfleld
»erage effluent BOD5 concenttation
Three approaches to assessing farfield dissolved
oxygen demand are described below:
Simplified mathematical models that predict dissolved oxygen depletion usin*
calculate techniques that do not require computer suppL; §
Numerical models that predict dissolved
and
oxygen depletion using a computer;
B-20
-------
• Evaluation of field data, using a data-intensive approach in which 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 detenmne for critical
conditions whether:
DO
STD
D0f - BODfa
B-ll
Where:
DOSTD = 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 farfield BOD exertion is required. If the
inequality is not true, then further analysis is requked.
SIMPLIFIED MATHEMATICAL MODELS
I
Oxygen depletion due to coastal or estuarine wastewater discharges is 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.
The first phase of the BOD reaction involves the oxidation of the carbonaceous organic
material. The nitrogenous stage includes conversion of organic nitrogen to ammonia and the
subsequent oxidation of ammonia to nitrite and then to nitrate. By U.S. convention, BOD
measurements are typically conducted for 5 days. In addition, many of the tests are run with a
nitrification inhibitor so that the test measures the oxidation of carbonaceous material only.
When total BOD is measured after 5 days (an inhibitor is not used), these tests are designated
as BOD5. When the 5-day test employs a nitrification inhibitor, the results are designated as
CBOD5 (U.S. EPA 1992). Long-term tests are also employed to measure ultimate BOD
to reflect the potential strength of the oxygen consumption.
B-21
-------
The effluent CBODL-to-CBOD5 ratio is required in dissolved oxygen modeling analyses
to estimate POTW GBODL from effluent CBOD5 data. For in-stream CBOD arising from a
wastewater inflow, the degree of treatment of the wastewater is important. Thomann and Mueller
(1987) summarize the CBODL-to-CBOD5 ratios for municipal wastes as 1.2 for no treatment, 1.6
for primary/secondary, 3.2 for activated sludge, and 2.84 for advanced primary (U.S. EPA 1992).
Some computer models (e.g., QUAL-II, QUAL2EU) specify this ratio as 1.46. The ratios are
a function of the deoxygenation rate coefficients and are wasteload- and receiving-water-specific.
In general, the higher the degree of treatment, the greater the degree of waste stabilization and
the lower the deoxygenation rate. The range of values reported as in-stream deoxygenation rates
or simply decay rates is wide, spanning more than two orders of magnitude (U.S. EPA 1985).
Before using CBOD5 to predict oxygen depletion, the applicant should convert it to
CBODL, the ultimate CBOD, by the following relationship:
CBODL = 1.46 CBOD-
B-12a
where the CBODL-to-CBODs ratio of 1..46 is calculated using a 0.23 day'1 decay rate at 20 °C
(U.S. EPA 1985) by the equation (Sawyer et al. 1978):
CBOD5
CBOD,
= l-e
B-12b
where:
k,, = the CBOD decay rate coefficient at T (°C)
t = Travel time corresponding to BOD5 (5 days).
A number of factors, including temperature, are known to influence the rate at which
CBOD is removed from the water column. The influence of these factors has been described by
both theoretical and empirical formulations. Like all biochemical processes, CBOD decay occurs
at a rate that increases with increasing temperature. Therefore, a temperature correction should
be made to account for the temperature dependence of the rate constant as follows:
kc = 0.23 x
c
B-13
B-22
-------
where:
kc ;= CBOD decay rate at temperature T (°C)
0.23 = CBOD decay rate coefficient at 20 °C i
0 = Temperature correction factor.
Once the temperature-corrected decay rate, kc, is calculated, the new CBODL-to-CBOD5 ratio can
be calculated using Equation B-12b. Studies indicate that the value of 1.047 for ® is valid
between 20 9C and 30 °C, but higher values are appropriate at lower temperatures (U.S. EPA
1985).
i
Data on the CBODL-to-CBOD5 ratio can vary considerably, not only between different
treatment levels but also between different sites with the same treatment levels. The consequence
of using a ratio that has not been developed from field data could be to underestimate the effect
of the wastewater on receiving water oxygen concentrations. Because of the importance of this
parameter and the observed variability in the ratio from site to site, it is recommended that site-
specific ratios be developed on a case-by-case basis (U.$. EPA 1984). In lieu of using average
values for CBOD decay rates, the applicant can determine actual values by collecting data on
effluent "bottle rates" using guidance found in Rates, Constants, and Kinetics Formulations on
Surface Water Quality Modeling (U.S. EPA 1985). i
I
i
The second phase of the BOD reaction involves the oxidation of the nitrogenous
compounds in the waste or water body. Th© transformation of reduced forms of nitrogen to more
oxidized forms (nitrification) consumes oxygen. Nitrification is a two-stage process facilitated
by nitrifying bacteria. The first stage i§ th§ oxidation of ammonia to nitrite principally by
nitrosompnas bacteria; the second stag§ i§ the oxidation of nitrite to nitxate principally by
nitrobacter bacteria. NBOD might not always, gontribute to oxygen depletion. If the applicant
discharges into open coastal waters where th@£@ 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 m0f@ enclosed estuarine waters, nitrification in the
water column has been documented by numerous water quality studies. Applicants should
analyze the potential impact of NBOD if thjy discharge into estuarine waters.
I
Although nitrification is a multistep proeess, a simplified approach to determining the
oxygen demand uses an overall oxidation rate of the NBOD, kN. The range of values of k^ is
approximately the same as for the deoxygenation coefficient of the CBOD. For deep, large
bodies of water, values of kN of 0.1-0.5/day at 20 °C are typical (Thomann and Mueller 1987),
B-23
-------
Assuming all reactions go to completion, the overall oxygen depletion can be estimated
based on data for total Kjeldahl nitrogen (TKN is the sum of organic nitrogen and ammonia
nitrogen) in the waste discharge using the following relationships:
NBODL = 4.57 (TKN)
B-14a
where NB,ODL is the ultimate NBOD. As with carbonaceous BOD, if NBOD5 is to be used to
predict oxygen depletion, the applicant should convert it to NBODL, the ultimate NBOD, by the
following relationship:
NBODL= 2.54 NBOD5
B-14b
where the NBODL-to-NBOD5 ratio of 2.54 is calculated using a 0.1 day'1 nitrification rate at 20
°C (U.S. EPA' 1985) by the equation (Thomann and Mueller 1987):
NBOD5
NBODL
= l-e
B-14c
where:
kN = the nitrification rate coefficient at T (°C)
t = Travel time corresponding to BOD5 (5 days).
A number of factors, including temperature, are known to influence the rate of
nitrification. The influence of these factors has been described by both theoretical and empirical
formulations. Like all biochemical processes, NBOD decay occurs at a rate that increases with
increasing temperature. Therefore,,a temperature correction should be made to account for the
temperature dependence of the rate constant as follows:
- o.iq x 0
-------
Once the temperature-corrected decay rate, KN, is calculated, the new NBODL-to-NBOD5 ratio
can be calculated using Equation B-14c. Although temperature correction factors are available
for both ammonia oxidation and nitrate oxidation, typically only one temperature correction factor
is used. Studies indicate that the value of 1.08 for 0 is valid between 10 °C and 30 °C; beyond
this temperature the nitrification rate is inhibited by the high temperature, sio the relationship no
longer holds (U.S. EPA 1985). At temperatures below 10 °C, the nitrifying bacteria apparently
do not multiply in any significant amount. Therefore, the rate kN is usually set equal to zero at
about 5-10 °C (Thomann and Mueller 1987).
•
The influence of pH on rates of nitrification is also quite important. If pH is outside the
range of 7.0 to 9.8, significant reductions in nitrification rates occur. The optimal pH for
nitrification is approximately 8.5; at pH values below approximately 6.0, nitrification is not
expected to occur (U.S. EPA 1985).
Simplified mathematical models are an acceptable alternative to the more complex
numerical models. In the simplest model of oxygen depletion, the following assumptions are
generally made:
I •
• 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).
I
• 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.
i
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 thai; the behavior of
dissolved oxygen concentrations in the wastefield can be examined to locate minimum values.
i
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.
i
B-25
-------
12 3
TRAVEL TIME (days)
CURVE
A
B
C
BODf
(ultimata)
(mg/L)
3.5
3.5
3.5
INITIAL
DO DEMAND
(mg/L)
66.
44.
0.
Figure B-4. Dissolved oxygen deficit vs. travel time for a submerged wastefield.
B-26
-------
For the three cases, the maximum deficits occur at the following travel times:
• 0.0 days for Curve A; ,..,.•
• - . I
• Approximately 0.2 day for Curve B; and
i •
• Approximately 4.0 days for Curve C.
i •'
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 rng/L for Curve
C. When the IDOD is 66 mg/L (a high value, 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. i
The simplified farfield oxygen depletion model for coastal waters suggested herein is
based on an approach developed by Brooks (1960) for 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:
DO(t) = DOa
DOf-DO.
B-16
where:
DO(t) = Dissolved oxygen concentration in a submerged wastefield as a function of
travel time t, mg/L ;
DOa = 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 coefficient
k,,; = NBOD nitrification rate coefficient
Lfc = Ultimate CBOD concentration above ambient at completion of initial
dilution, mg/L
Lfn = Ultimate NBOD concentration above ambient at completion of initial
dilution, mg/L
B-27
-------
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 (DOa-DOf) plus that caused by exertion of BOD in the
water column. The last term in the equation estimates the exertion due to NBOD. The dissolved
oxygen deficit tends to decrease at longer travel times 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 attauied 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:
e = e_ —
' olb
B-17
where:
, 6 = Lateral diffusion coefficient, ft2/sec
E0 = 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.
The initial diffusion coefficient can be predicted from:
e0 = 0.001 b4'3 ft2/sec
B-18
Based on the 4/3 law, the centerline dilution, Ds, is given by:
B-28
-------
1.5
- 1
1/2
B-19
where:
t = Travel time, sec
erf = The error function.
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
Ds -erf
1.5
- 1
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:
,2 V/2
B-21
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, if 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.
I
The figure also reveals that the predicted dilutions are substantially idifferent, 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
B-29
-------
•
-------
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: !
D =
kw
where:
D
A:
k
k2
EL
w
A(k2-k)
Dissolved oxygen deficit ;
Cross-sectional area of the estuary near the discharge site
CBOD decay rate constant
Reaeration rate constant
Longitudinal dispersion coefficient
Mass loading rate of CBOD.
B-22
The applicant can predict the deficits due to NBOD by using the appropriate k and W values and
adding the two deficits to obtain 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
A
-4
B.23
where:
= Cross-sectional area in m2
B-31
-------
W,
D
P,.,
.= Mass emission rate of CBOD, g/day
= Mass emission rate of NBOD, g/day
= Dissolved oxygen deficit, mg/L.
ThejNBOD term can be added when data are available.
'NUMERICAL MODELS
Numerical models are an acceptable method of predicting oxygen depletion caused by a
discharge. Numerical models may consider the combined effect of farfield demand in the water
'column as discussed ab6ve, 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 is 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 that 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 distarice
from the diffuser. The volume of the segments in the immediate vicinity of the diffuser should
approximate the volume of the ZID 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 configuration by starting with a coarse grid and then decreasing grid size
until the model results do not significantly change.
B-32
-------
, A steady-state numerical model is acceptable for the dissolved ox3^gen analysis because
dynamic of unsteady analyses are generally more costly, are more difficult to implement, and
require more data. The applicant should consider, however, whether intfatidal 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.
i
• 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 usually 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
because of conditions unrelated to the discharge (e.g., upwelling effects).
Consequently, dissolved oxygen depletions associated with the discharge can
be masked by background variability.
B-33
-------
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 should 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-34
-------
B-IV. SEDIMENT OXYGEN DEMAND
The oxygen depletion due to a steady sediment oxygen demand can be predicted by:
where;
ADO =
SB XM
B-24
86,400 UHD 86,400 UHD
ADO
SB
XM
H
U
a =
S
D
Oxygen depletion, mg/L
Average benthic oxygen demand over the deposition area, g O2/m2/day
Length of deposition area (generally measured hi longshore direction), m
Averap depth of water column influenced by sediment oxygen demand,
measured above bottom, m "
Minimum sustained current speed over deposition area, m/sec
Sediment decay rate constant, 0.0 I/day
Oxygen:sediment stoichiometric ratio, 1.07 mg O2/mg sediment
Average concentration of deposited organic sediments over the deposition
area, g/m2 !
Dilution caused by horizontal entrainment of ambient water as it passes over
the deposition area (always > 1).
Both S and XM can be determined from the analysis performed in Chapter B-I, Suspended Solids
Deposition. Figure B-3 in that chapter shows an example plot of seabed deposition. For that
example, an estimate of S is the average of the maximum and minimum values, or
= 52
B-25
The distance XM, measured parallel to the coast and within the 5-g/m2 contour, is 8,000 m,
The depth of water affected by the sgdjment 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:
a/2
H = 0.8
U
B-35
-------
where:
= Vertical diffusion coefficient (cmVsec).
For the example case where U = 3 cm/sec, XM = 8,000 m, and ez = 1 cnWsec,
„ . 0.8 x
x
. u m
B-27
If the applicant desires to compute a value of vertical diffusivity, the following empirical
expression can be used:
1(T4
ez =
B-28
p dz
where: .
P
d£
dz
= Vertical diffusion coefficient, cnvVsec
= 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 obtained 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.
B-36
-------
TABLE B-5. SUBSEQUENT DILUTIONS" FOR VARIOUS INITIAL FIELD
WIDTHS AND TRAVEL TIMES
Travel
Time (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
26/>100
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 1,000 5,000
1.0/1.1
1.2/1.3
1.4/1.9
1.9/3,5
2.5/7.3
3.0/12
1.0/1.0 1.0/1.0
l.l/l.l 1.0/1.0
1.2/1.5 1.0/1.0
1.5/2.3 1.1/1.2
2.0/4.4 1.4/1.7
2.4/6.8 1.6/2.3
4.2/30 3.4/16 2.1/4.4
5.9/80
7.3/>100
t.7/41 2.8/10
5.8/73 3.4/17
8.4/>100 6.6/1.00 3.9/24
" The dilutions are entered in the table as N,/N2, where N, is the dilution assuming a constant diffusion coefficient 2nd N2 is the dilution assuming
the 4/3 law.
Oxygen Demand Due to Resuspension of Sediments
It is more difficult to accurately predict oxygen demand due to resuspension than that 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 (Chapter B-I).
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 hours.
B-37
-------
The applicant should compute the oxygen depletion as a function of time during this
period. This can be done using the following relationship:
Sr (-kt\
ADO = —r- [ 1-exp—- ]
DH I 24 J
B-29
where:
ADO = Oxygen depletion, mg/L
Sr = Average concentration (in g/m2) of resuspended organic sediment (based on
90-day accumulation)
H = Depth of water volume containing resuspended materials, m
k,. = 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 =
1.6
100
(3,600 t e'z)1/2
B-30
where:
e'z = Vertical diffusion coefficient when resuspension is occurring (5 cm2/sec)
t = Elapsed tune following resuspension, h.
The applicant should check to be sure that H does not exceed the water depth. If it does, H
should be set 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-hour increments for a period of up to 24 hours.
The results can be tabulated as shown below. Data and calculations should be included in the
application.
B-38
-------
t(h)
0
3
6
9
12
15
18
21
24
DO (mg/U
0
predictions
Most often, a maximum depletion will occur somewhere in the 24-hour period, with depletions
decreasing for larger travel times.
B-39
-------
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:
where:
SSf
SSa
SSe
S.
- ss
B-31
Suspended solids concentration at completion of initial dilution, mg/L
Affected ambient suspended solids concentration immediately upcurrent of
the diffuser averaged over one-half the tidal period (12.5 hours) and from
the diffuser port depth to the trapping level, mg/L
Effluent suspended solids concentration, mg/L
Initial dilution (flux-averaged).
The maximum change, DS, due to the effluent can be computed as follows:
AS = SSJSa
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
concentration. In these cases, the final suspended solids concentration will be below the
background concentration.
EPA requires data for periods of maximum stratification and for other periods when
discharge characteristics, oceanographic conditions, water quality, or biological seasons indicate
that 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.
B-40
-------
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 concentration may be
difficult because of a general lack of data. A common problem for coastal sites is that measure-
ments 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 ZED 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. ;
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
TABLE B-6. SELECTED BACKGROUND SUSPENDED SOLIDS CONCENTRATIONS
Water Body
Suspended Solids
Concentration, mg/L
Cook Inlet, AK
Southern California Bight
Pacific Ocean near San Francisco, CA
Broad Sound, MA
Massachusetts Bay near South Essex
New Bedford Harbor, MA
East River, NY
Ponce, PR (near shore)
Puget Sound, WA
Outer Commencement Bay, Tacoma, WA
Commencement Bay near Puyallup River, WA
Tacoma Narrows, WA
250-1,280
0.7-60
1-33
18.6-25.2
1.2-30.5
0.4-6.1
6.0-25.6
13.5
0.5-2.0
33-51
23-136
33-621
Note: Data are from 301 (h) applications.
B-41
-------
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-42
-------
B-VI. EFFLUENT pH AFTER INITIAL DILUTION
The calculation of effluent pH following initial dilution is chemically more sophisticate4
than other chemical calculations in this document. This chapter 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, assuming that all of the required variables
are known, is described herein. These variables include initial dilution and the temperature,
salinity, pH, and alkalinity of the effluent and the receiving water. Effluent ;ind receiving water
temperature, salinity, and pH are normally measured. The initial dilution (usually critical) 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 v/ater nor that of
the effluent is usually measured. The alkalinity of seawater is relatively constant, however, a^
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 tune
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:
[H+] [HCOi] I [H2COi] ^
[JT] [CO,2'] I [HCOi] = K2
[H+] [OH-] = Kw
CT =
Alkalinity =
2[CO32"] + [OH~] - [H+]
B-33
B-34
B-35
B-36
B-37
where:
B-43
-------
[H2CO3*j = The sum of aqueous CO2 and true H2CO3 concentrations
Cj. = Total carbonate concentration.
The carbonate species can also be expressed in terms of ionization fractions a0, a1? and cc2
[HCO3~] = CTa1
[co32-] = CT «2
B-38
B-39
B-40
where:
-i
12
-1
B-41
B-42
B-43
Substitutuig the hydroxide-hydrogen ion relationship and ionization fractions into the alkalinity
equation yields:
Alkalinity = CT (a. + 2a,) + —^- - \H+]
T \ 2f +
B-44
Because total carbonate is conserved and a! and cc2 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.
B-44
-------
• Calculate ion product of water, Kw, and carbonate dissociation
constants, Kt and K2, of the effluent and receiving water based on
temperature and salinity data.
• Check consistency between alkalinity and pH of both effluent and
receiving water.
,i
• Calculate total carbonate in effluent and receiving water separately.
• Calculate total carbonate, alkalinity, salinity, and temperature of the
effluent-receiving water mixture following initial dilution (based on
proportions of effluent and receiving water).
• Calculate K^,, Kt, and K2 for the effluent-receiving water mixture
following initial dilution.
• Use a stepping procedure to find pH based on the computed values for
total carbonate and alkalinity of the effluent-receiving water mixture.
,
• Record results.
i
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:
^ = 3'407-7 + 0.03279T - 14.8435
(Kelts and Hsu 1978, p. 300)
B-45
K = 2,902.4 + 0.023797- - 6.498
2 T
(Kelts and Hsu 1978, p. 300)
B-46
—lYf _ yT* * f\ f\if](\fZ'T' _ fi
P w T~ ' '
(Stumm and Morgan 1981, p. 127) B-47
For receiving water and the effluent-receiving water mixture:
B-45
-------
pK = 3,404.7 + Q.03279T - 14.712 - 9.157551/3
* L fin
(Stumm and Morgan 1981, p. 205)
= 2>902'4 + 0.02379T - 6.471 - 0.385551/3
T
pKw =
3>44LO + 2.241 - 0.09255 1/2
where:
T
S
= Temperature in degrees Kelvin
= Salinity in ppt.
The receiving water equations are valid for salinities down to about 10 ppt.
B-48
(Stumm and Morgan 1981, p. 206) B-49
(Dickson and Riley 1979, p. 97) B-50
B-46
-------
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 tide sireal 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 transmittance measurements,
others leave the selection of the sampling methods to the discretion of the applicant.
I
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 hi 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.
i
A Secchi disc is used to make visual observations of water clarity. ELecords 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
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 euphotic zone. Since a
wastewater plume can be held below the upper regions of this zone during periods of
stratification, however, Secchi disc measurements may not be appropriate under all conditions.
i
I
Beam transmittance is measured with a transmissometer and is a measure of the
attenuation of a collimated beam of artificial light along a fixed path length (usually 1 m). 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:
B-47
-------
T =
B-51
where:
a
= The proportion of light transmitted along a path of length d, m
= 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 uses 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 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 unproved 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:
Tf=T
f a
B-52
where:
Turbidity in receiving water at the completion of initial dilution, typically
NTU or Jackson turbidity units (JTU)
Ambient or background turbidity
B-48
-------
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 turbidity increase. These analyses
consist of determining the turbidity of a seawater-effluent mixture prepared in 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 isolids concentrations)
as well as lowest initial dilutions. Values of the initial turbidity of the sieawater, the effluent
mixture, and the simulated dilution should accompany all test results.
', I
i
By deriving a relationship between turbidity and Secchi depth and using 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 depth
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
depth, or:
B-53
and
oc -
A
SD
B-54
where k^ and k2 are constants that 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 depth and
turbidity becomes:
B-49
-------
B-55
When state standards are written in terms of Secchi depth, it is convenient to combine Equations
B-52 and B-55 to yield:
1
SDf SO
B-56
or
SDe =
SDf
S +
a
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
SDC = Critical Secchi disc depth of effluent.
In this manner, the critical effluent Secchi depth (SDJ 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 used to provide an estimate of the
effect of the wastewater discharge on the receiving water. This method should be used only
where the standard is exclusively hi 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 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.
B-50
-------
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
Ambient Secchi Depth (m)
2
18
10
5
3
2
3
14
7
4
2
1
4
13
7
3
2
1
5
12
6
3
2
1
10
11
6
3
2
1
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 at a minimum. Under these same conditions,
however, Secchi disc readings might 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 liquations B-51 and B-58, turbidity can be expressed as:
B-51
-------
JTU =
B-59
kd
where:
= Fraction of beam transmittance over distance d.
The coefficient of proportionality (k) takes on values 0.5-1.0. Therefore, to use these
relationships to demonstrate compliance with a turbidity standard based on existing light
transmittance 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-52
-------
B-VIII. OTHER WATER QUALITY VARIABLES
l
i
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 completion of initial
dilution, the concentration in the receiving water, assuming the ambient concentration is 0.0
mg/L, can be estimated as follows:
a = cie i sa
B-60
where:
Clf = Chlorine residual at completion of initial dilution, mg/I
Cle = Chlorine residual in effluent, mg/L
Sa = Lowest flux-averaged initial dilution.
B-53
-------
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 whether algal
blooms, red tides, or other unusual biological activity has occurred near the discharge site hi 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 manner similar to that used for
suspended solids:
B-61
where:
Q
= Affected ambient concentration immediately upcurrent of diffuser, mg/L
= Effluent concentration, mg/L
= Initial dilution (flux-averaged)
= 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:
(CJmax = Ca + (Sfl)min (C--CJ
B-62
B-54
-------
where:
= Maximum allowable effluent concentration such that water quality criteria
are not exceeded
= Applicable water quality criterion
Minimum expected initial dilution. '
(Sa)min =
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 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 coliform bacteria or enterococci and are usually
expressed as a mean or median bacteria count and a maximum limit that carimot 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.
j
The coliform bacteria count at the completion of initial dilution due to the discharge can
be estimated as follows:
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 applicant's values. The
B-55
-------
predicted value can be compared with the appropriate standard at the ZID boundary. This value
can also be used to estimate the bacteria concentration at specific locations away from the ZID.
Because different limits may apply to specific areas (e.g., shellfish-harvesting areas,
beaches, diving areas), the maximum bacteria count at a specified distance from the discharge
may be of concern. This bacteria count can be estimated in a manner analogous to the estimation
of the BOD exerted as the wastefield spreads out from the ZID. The maximum bacteria count
at the centerline of the wastefield can be estimated as a function of distance from the discharge
as follows:
B-64
where:
Bx = Bacteria count at distance x from ZID, #7100 mL
Ba = Affected ambient bacteria count immediately upcurrent of diffuser,
#7100 mL
Bf = Bacteria count at completion of initial dilution, #7100 mL
Ds = Dilution attained subsequent to initial dilution at distance x
Db = "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 bacteria count is negligible or the effect
of the discharge alone is desired, the terms for the ambient bacteria count can be dropped,
simplifying Equation B-64 to:
B =
B-65
Values for subsequent dilution as a function of 12e0t/B2 are shown in Figure B-5. Guidance on
methods for estimating subsequent dilution for sites located in narrow estuaries or bays is
included in Chapter B-III (Farfield Dissolved Oxygen Demand).
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.
B-56
-------
If no violations would occur, then further calculations are not needed. Floccula.tion and sedimen-
tation can cause an apparent decrease in the 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 ssiltwater and exposure
to sunlight only are considered. The dieoff due to exposure to saltwater, Disw, and the dieoff due
to exposure to sunlight, Dsl, are (Gameson and Gould 1975):
B-66
Dsl =
B-67
where:
ksw = Bacteria decay rate due to exposure to saltwater, 1/h
oc = Constant, m2/MJ
I(t) = Total intensity of sunlight received by bacteria during the travel time, MJ/m2
t = Travel tune, h.
The bacteria dieoff due to the combined effects of saltwater and sunlight is Db = D^D^.
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 can be 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 exposure to saltwater is known for both coliform bacteria
and enterococcus bacteria. For coliform bacteria,
= 2.303 exp[(0.0295T - 2.292)2.303] / h
B-57
B-68
-------
where
T = water temperature (in degrees Celsius), based on~fteH measurements at
Bridport (Dorset, England) (Gameson and Gould 1975).
The enterococcus bacteria dieoff rate due to exposure to saltwater is:
= 0.5262 / (24 A)
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 hi the direction of interest.
B-58
-------
REFERENCES
American Public Health Association, American Water Works Association, and Water Pollution
Control Federation. 1985. Standard methods for the examination of water and wastewater. 16th
ed. Port City Press, Baltimore, MD. '
Austin, W.R. 1974. Problems in measuring turbidity as a water quality parameter. In Proc.
Seminar on Methodology for Monitoring the Marine Environment, EPA-600/4-74-Q04, pp, 23-54,
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. In Pjroc. 1st International
Conference on Waste Disposal in the Marine Environment, University of California, Berkeley,
CA, July 1959, pp. 246-267. 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-K^,. Mar
Chem. 7:89-99. i
Gameson, A.L.M., and D.J. Gould. 1975. Effects of solar radiation on the mortality of some
terrestrial bacteria hi seawater. In Discharge of sewage from sea outfalls. Proc. of an
international symposium held at Church House, London, 27 August to 2 September 1984, ed.
A.L.M. Gameson, pp. 209-219. Pergamon Press, Oxford, UK.
Grace, R. 1978. Marine outfall systems planning, design, and construction. Prentice-Hall, Inc.,
Englewbod Cliffs, NJ.
Graham, J.J. 1966. Secchi disc observations and extinction coefficients in the central and
eastern North Pacific Ocean. Limnol. Oceanogr. 2:184-190.
i
Green, E.J., and D.E. Carritt. 1967. New tables for oxygen saturation of seaiwater. 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 wastewaters through submarine outfalls. Part
I. Sedimentation flux estimation. Final report. Prepared for U.S. Environmental Protection
Agency, Environmental Research Laboratory, Newport, OR. Southern California Coastal Water
Research Project Authority, Long Beach, 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.
B-59
-------
Kelts, K., and KJ. Hsu. 1978. In Lakes: Chemistry, geology, physics, ed. A. Lerman, pp.
295+. 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.
Sawyer, C.N. and P.L. McCarty 1978. Chemistry for environmental engineers. McGraw-Hill
Book Company, New York, NY.
Stumm, W., and JJ. Morgan. 1981. Aquatic chemistry. John Wiley and Sons, Inc., New York,
NY.
Thomann, R.V., and J.A. Mueller 1987. Principles of surface water quality modeling and control.
Harper and Row, Publishers, New York, NY.
U.S. EPA. 1982. Revised section 301 (h) technical support document. EPA-430/9-82-011. U.S.
Environmental Protection Agency, Washington, DC.
U.S. EPA. 1982b. Design of 301(h) monitoring programs for municipal wastewater discharges
to marine waters. EPA-430/9-82-010. U.S. Environmental Protection Agency, Washington, DC.
U.S. EPA. 1984. Before and after case studies: Comparisons of water quality following
municipal treatment plant improvements. EPA 430/9-007. U.S. Environmental Protection
Agency, Office of Water, Washington, DC.
U.S. EPA. 1985. Rates, constants, and kinetics formulations on surface water quality modeling.
2d ed. EPA/600/3-85/040. U.S. Environmental Protection Agency, Environmental Research
Laboratory, Athens, GA.
U.S. EPA. 1987. A simplified deposition calculation (DECAL) for organic accumulation near
marine outfalls. Final report. U.S. Environmental Protection Agency, Office of Marine and
Estuarine Protection, Washington, DC.
U.S. EPA. 1992. Technical guidance manual for performing waste load allocations, Book II, Part
1: Biochemical oxygen demand/dissolved oxygen and nutrients/eutrophication. Draft report. U.S.
Environmental Protection Agency, Office of Science and Technology, Washington, DC.
Wallace, J.M., and P.V. Hobbs. 1977. Atmospheric science: An introductory survey. Academic
Press, New York, NY.
B-60
-------
APPENDIX C
BIOLOGICAL ASSESSMENT
-------
-------
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 discharges. 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). Table C-l lists biological
assessment documents developed to support the activities of the 301(h) program. Slight to
moderate enrichment results in slight increases in number of species, abundance, and biomass of
benthic communities (see Figure 3 in main text), while species composition remains unchanged.
As enrichment increases, the number of species declines 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 the
abundance of benthic organisms as conditions become intolerable for most taxa.
TABLE C-l. TECHNICAL SUPPORT AND GUIDANCE DOCUMENTS FOR
BIOLOGICAL ASSESSMENT
Document
EPA Document Number
Recommended biological indices for 301(h) monitoring
programs.
Bioaccumulation monitoring guidance: 1. Estimating the
potential for bioaccumulation of priority pollutants and 301(h)
pesticides discharged into marine and estuarine waters.
Bioaccumulation monitoring guidance: 2. Selection of target
species and review of available bioaccumulation data. Volume I.
Bioaccumulation monitoring guidance: 2. Selection of target
species and review of available bioaccumulation data. Volume
II.
Bioaccumulation monitoring guidance: 3. Recommended
analytical detection limits.
Bioaccumulation monitoring guidance: 4. Analytical methods
for U.S. EPA priority pollutants and 301(h) pesticides in tissue
from estuarine and marine organisms.
Bioaccumulation monitoring guidance: 5. Strategies for sample
replication and compositing.
EPA 430/9-86-002
EPA 503/3-50-001
EPA 430/9-86-005
EPA 430/9-86-006
!
EPA 503/6-90-001
I
EPA 503/6-90-002
EPA 430/9-87-003
C-l
-------
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 abundance 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 abundance, 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.
Comparable models that describe changes in the structure and function of plankton and
demersal fish communities hi 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 can be used to conduct biological comparisons for section
301(h) applications. Applicants can analyze the data graphically or statistically or can 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-ZED, 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 reference station or both. Even without such tests, however, 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 ZED-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 instructive 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 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.]
C-2
-------
1U
u
Ij
a
ui
cc
cc
ui
a.
to
ui
u
Ul
U.
O
OC
ui
m
«,-
30-
10-
REFEHENCE REFERENCE
1 2
ZO-
BOUNDARY 1
WITHt*-
ZID
ZID-
BOUNDARY 2
NEAHFIELD
STATION
RANGE OF
- REFERENCE
CONDITIONS
NET
CURRENT^
DIRECTION
FARFIELI)
Figure €-1. Number of species collected in replicate grab samples at stations in the vicinity of the outfall.
Q.
a.
34-i
33-
32H
31-
30
REFERENCE REFERENCE ZIO- tMIHM- ZID- NEA8FIELD FA11FIELD
1 2 80UNOABY1 ZIO BOUNOARY2
STATION
Figure C-2.1 Salinity at stations in the vicinity of the outfall.
C-3
-------
z
o
m
oc
<
o _
0=
is
o
H
1.0-
0.0
REFERENCE REFERENCE ZID-
1 2 BOUNDARY 1
WITHIN-
210
ZIO- NEARFIELD FA/1FIEI 0
STATION
Figure C-3. Total organic carbon content of the sediments at stations in the vicinity of the outfall.
SAND
NEARREID
REFERENCE a
' (Clayey Sflt) j (SiByCtay)
SILT
CLAY
Figure C-4. Sediment grain size characterization at stations in the vicinity of the outfall.
C-4
-------
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 comparisons 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
procedures.
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: (1) the error of an estimate is
a random normal variate, (2) the data are normally distributed, and (3) 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. j
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 this reason, tests for normality are not usually conducted
i
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).
: i
Several tests are available to determine whether variances are homogeneous. 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).
C-5
-------
When sample variances are found to differ significantly (P<0.01), a transformation should
be applied to the data. [A more conservative probability 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 be used only 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 test is performed, significant differences (P<0.05)
among individual stations or groups of stations may be determined using the appropriate a
posteriori comparison. Of most importance 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 on which determination of the presence or absence of a balanced
indigenous population is based.
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: (1) calculation of a matrix of
similarity values for all possible station pairs and (2) 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 has 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 ecol-
ogical 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
C-6
-------
the group average clustering strategy and the flexible sorting strategy are recommended because
they produce little distortion of the original similarity matrix. [See U.S. EPA (1985) for
additional rationale on the use of these three indices.]
C-7
-------
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.
Gauch, H.G. 1982. Multivariate analysis in community ecology. Cambridge Studies in Ecology:
1. Cambridge University Press, Cambridge, UK.
Green, R.H. 1979. Sampling design and statistical methods for environmental biologists. John
Wiley & Sons, Inc., New York, NY.
Hruby, T. 1987. Using similarity measures in benthic impact assessments. Envir. Mon. Assess.
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.
Romesburg, H.C. 1984. Cluster analysis for researchers. Lifetime Learning Publications,
Belmont, CA.
Shepard, P.P. 1954. Nomenclature based on sand-silt-clay ratios. J. Sed. Petrol. 24:151-158.
Shepard, P.P. 1963. Submarine geology. 2d ed. Harper and Row, New York, NY.
Sokal, R.R., and FJ. Rohlf. 1981. Biometry. 2ded. W.H. Freeman & Co., San Francisco, CA.
U.S. EPA. 1985. Summary of U.S. EPA-approved methods, standard methods, and other
guidance for 301(h) monitoring variables. EPA-503/4-90-002. U.S. Environmental Protection
Agency, Office of Water, Washington, DC.
Winer, BJ. 1971. Statistical principles in experimental design. 2d ed. McGraw-Hill Book Co.,
New York, NY.
Zar, J.H. 1974. Biostatistical analysis. Prentice-Hall, Inc., Englewood Cliffs, NJ.
Co
-o
-------
APPENDIX D
NAVIGATIONAL REQUIREMENTS AND METHODS
-------
-------
CONTENTS
FIGURES • D-iv
TABLES . I D-iv
MONITORING STATION LOCATIONS . . . D-l
ACCURACY LIMITATIONS ....... |. . . . D-l
POSITIONING ERROR D-3
SUMMARY OF RECOMMENDED PROCEDURES AND EQUIPMENT D-6
CANDIDATE SYSTEM SELECTION [ D-6
SHALLOW-WATER POSITIONING METHODS : D-8
USE OF LORAN-C i D-10
SYSTEM SELECTION PROCEDURE D-10
REFERENCES [ D-14
D-iii
-------
FIGURES
Number
Page
D-l 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-5
D-3 Examples of differential Loran-C error ellipse orientation
at a ZID-boundary sampling station D-ll
D-4 Navigation system preliminary screening criteria . , D-l3
TABLES
Number Page
D-l Example ZID-boundary station locations D-4
D-2 Summary of recommended systems D-7
D-3 Theoretical error ellipses of differential Loran-C for
various U.S. locations D-12
D-iv
-------
NAVIGATIONAL REQUIREMENTS AND METHODS
The information presented below addresses navigational requirements and methods for
section 301(h) dischargers. It summarizes more detailed discussions in U.S. EPA (1987, 1988).
i
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-bouhdary stations (Stations Z0, Zt, Z2 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 (Gt, G2, G3, G4) and control or reference (Ct)
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 (H15 H2). The ability to conduct
sampling at the appropriate depth contour is also very important. Sampling programs for 301(h)
typically include the requirement 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 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
D-l
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< CQ
(T < IU
OX CC
««•«•«
it OXECOH-IM
D-2
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boundary and must 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.
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,
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.
1 i
j
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 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 ZED boundary, and the
farthest from the diffuser that sampling would occur is 40 percent of the water depth beyond this
D-3
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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.
When discharge depths are less than approximately 15 m (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 ZED 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 ZED probably will not be a problem if
the same navigational equipment used to locate ZID-boundary stations is also used elsewhere.
TABLE D-l. EXAMPLE ZED-BOUNDARY STATION LOCATIONS
Average
Diffuser
Depth
(m)
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
3,1.5
21.5
11.0
6.5
Recommended
Station
Location3
(m)
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
Error1"
(m)
±20
±18
±16
±14
±12
±10
±8
±6
±4
±3
±3
±3
±3
"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 15m (49 ft).
*Error magnitude is equal to ±20 percent of the average diffuser depth when over 15m (49 ft).
D-4
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ZID BOUNDARY
STATION
LOCATION
100 m DEPTH
4.0 m OlFFUSEFf
ERROR
LIMIT
. . Z!D
BOUNDARY
60 m DEPTH
3:0 m DIFFUSEFf
24m-
123m
73.5 m
20 m DEPTH
1.8 m DIFFUSER
a m.
24.9
Figure D-2. Locations of ZID-boundary stations for selected ZID sizes.
D-5
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SUMMARY OF RECOMMENDED PROCEDURES AND EQUIPMENT
Based on the U.S. EPA'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 might not always be available.
CANDIDATE SYSTEM SELECTION
The details of positioning techniques and associated equipment are described in U.S. EPA
(1988). 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.
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.
D-6
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TABLE D-2. SUMMARY OF RECOMMENDED SYSTEMS
Representative
Category Equipment8 Accuracy
Advantages
Disadvantages
Theodolite
Sextant
Table B-l
Table B-2
Table B-3
EDMI
Table B-4
Total stations Table B-5
Microwave Table B-6
navigation
systems
Range-azimuth Table B-10
systems
10-30 sec
±1 m (3.3 ft)
±10
±2 m (6.6 ft)
1.5-3.0 cm
5-7 cm
±1-3 m
Traditional method. Line-of-sight. Two manned
Inexpensive. High accuracy, shore stations. Simultaneous
Successfully applied. measurements. Limits on
Restricted areas. intersection angles. Area
coverage; station movement.
Rapid. Easy to implement. Simultaneous measurement of
Most widely used. Low cost, two angles. Target visibilities
No shore party. High location, maintenance. Line-of-
accuracy. sight. Eiest in calm conditions.
Limits on acceptable angles.
Extremely accurate. Usable
for other surveying projects.
Cost. Compact, portable,
rugged.
Motion .and directionality of
reflectors. Visibility, unless
microwave. Two shore stations
Ground wave reflection.
Single onshore station. Other Reflector movement and
uses. Minimum logistics. directionality. Prism costs.
Satellite
systems
Table B-9
No visibility restrictions.
Multiple users. Highly
accurate. Radio line-of-
sight.
0.01° and 0.5 m High accuracy. Single
station. Circular coverage.
1-10 m High accuracy. Minimum
(initial units)logistics. Use
in restricted/congested areas.
Future cost. No shore
stations.
Cost. Multiple onshore stations
Logistics. Security.
Single user. Cost.
Current coverage. Initial
development cost.
" Table references refer to U.S. EPA (1987).
i
Multiple Horizontal Angles
.
In the multiple horizontal angles category, theodolites were found to have the angular
accuracies required for the maximum ranges anticipated. They are relatively inexpensive, and
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.
i
By comparison, sextant angle resection can be performed using one instrument if the
vessel is stationary or using two instruments simultaneously if the vessel is moving. Achievable
angular accuracy of ±10 seconds is adequate, and relatively inexpensive sextants are readily
D-7
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available. Again, visible range can be limiting. Shooting an accurate fix from a nonstationary
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 usually 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 dkection could result in
substantial additional costs. 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 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.
Range and Angle
Systems hi 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. Optical and infrared range limitations apply to these systems. The three
range-azimuth navigational systems examined provide sufficient positional accuracy with a single
station.
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 can be used to establish the required distances to nearby water quality or
D-8
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biological sampling stations. An optical range finder is used by simply focusing a split image
on the target float, enabling the slant 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 nip 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 rn (984 ft).
An acceptable alternative method for collecting bottom samples from desired locations
in shallow water is to use divers. If visibility is adequate, divers can 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 the ranges. 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 hi 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.
' " ' " j
Permanent installation of a marker buoy at the outfall terminus or midpoint of the diffuser
i '
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. It is not uncommon, however, 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.
D-9
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Because the techniques described here are inexpensive to implement (as is use of the
sextant resection or theodolite intersection method), 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 its evaluation of positioning methods, U.S. EPA (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 reexamined in Evaluation of Differential Loran-C for Positioning in Near shore Marine
andEstuarine Waters (U.S. EPA 1988). The special operating mode, called differential Loran-C,
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.
Use of differential Loran-C was found to significantly improve the positional accuracies
achievable with 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 procedures, a video display, and data-averaging techniques. Higher accuracies are
expected in other coastal areas where unproved 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 ZDD-boundary station location is provided in U.S. EPA (1988).
SYSTEM SELECTION PROCEDURE
A procedure for selecting an appropriate navigation system is described in detail in
U.S. EPA (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 me screening process, systems that cannot achieve the required criterion are removed
from further consideration.
D-10
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OUTFALL PIPE
Z!D
BOUNDARY
ELLIPSE ROUGHLY
PARALLEL TO DIFFUSER
ACROSS ZID
ERROR VARIATION
ELLIPSE ROUGHLY •
PERPENDICULAR TO
DIFFUSER
95% PROBABILITY
ELLIPSE
ACROSS-Z1D
ERROR VARIATION
X.Y Coordinates of Z1D-
Etoundary Sampling
Station.
I
HU 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-ll
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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 Axis"
70
180
60
90
90
50
30
40
30
Length
of
Minor Axis8
20
40
30
30
20
20
20
20
20
"Lengths are given to the nearest 10 m based on 95 percent confidence level error ellipses. Standard deviation of time differences is 25 nsec
(achievable with differential Loran-C).
D-12
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Figure D-4. Navigation system preliminary screening criteria.
D-13
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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 out of LORAN-C.
Advisory Program, Oregon State University, Corvallis, OR.
SG 54. Extension Marine
U.S. EPA. 1987. Evaluation of survey positioning methods for nearshore and estuarine waters.
EPA-430/9-86-003. U.S. Environmental Protection Agency, Office of Marine and Estuarine
Protection, Marine Operations Division, Washington, DC.
U.S. EPA. 1988. Evaluation of differential Loran-C for positioning in nearshore marine and
estuarine waters. Draft report. U.S. Environmental Protection Agency, Office of Marine and
Estuarine Protection, Marine Operations Division, Washington, DC.
D-14
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APPENDIX E
URBAN AREA PRETREATMENT REQUIREMENTS
-------
-------
CONTENTS
FIGURES i E-v
TABLES , E-vi
INTRODUCTION j E-l
CHARACTERIZATION OF DISCHARGE AND SELECTION OF APPROACH E-4
i
INDUSTRIAL WASTE SURVEY | E-4
REPRESENTATIVE SAMPLING PROGRAM AT POTW ! E-12
SELECTION OF APPROACH i E-12
I
APPLICABLE PRETREATMENT REQUIREMENT APPROACH . E-14
BACKGROUND AND GENERAL APPROACH E-14
U.S. EPA PROCEDURES FOR DEVELOPING TECHNICALLY
BASED LOCAL LIMITS E-16
SECONDARY REMOVAL EQUIVALENCY APPROACH '\ E-32
SECONDARY TREATMENT PILOT PLANT DESIGN CRITERIA E-36
SECONDARY TREATMENT PILOT PLANT START-UP E-37
SECONDARY TREATMENT PILOT PLANT OPERATING CRITERIA E-41
TOXIC POLLUTANT MONITORING PROGRAM, TESTING PROCEDURES,
AND QUALITY ASSURANCE/QUALITY CONTROL (QA/QC) E-48
SAMPLING FREQUENCY E-49
SAMPLE COLLECTION AND ANALYSIS E-50
QUALITY ASSURANCE/QUALITY CONTROL (QA/QC) E-63
•
UPGRADING TO A FULL-SCALE SECONDARY TREATMENT FACILITY E-70
DEMONSTRATING COMPLIANCE USING PILOT PLANT DATA E-74
REFERENCES E-75
E-iii
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CONTENTS (continued)
ATTACHMENT 1: INDUSTRIAL USER MANAGEMENT PRACTICES
ATTACHMENT 2: LOCAL LIMITS DERIVATION EXAMPLE
-------
FIGURES
Number
E-l
E-2
E-3
E-4
E-5
Urban area pretreatment requirements E-5
Detailed flow sheet for a chemical-specific approach
to identifying pollutants of concern to treatment plant
operations , E-22
Equation for deriving allowable POTW influent loadings ;
from in-plant criteria E-27
i
!
Secondary pilot plant demonstration j E-33
Components of a conventional activated sludge system E-3 8
E-v
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TABLES
Number Page
E-l Pollutant occurrence in industrial waste water E-7
E-2 List of pesticides and toxic pollutants E-18
E-3 Resource Conservation and Recovery Act (RCRA)
Appendix 9 constituents E-20
E-4 Effluent water quality values that shall not be exceeded
under secondary treatment E-36
E-5 Secondary treatment pilot plant design criteria E-37
E-6 Conventional activated sludge design parameters E-39
E-7 Pilot plant monitoring schedule E-41
E-8 List of test procedures approved by U.S. EPA for
inorganic compounds in effluent E-51
E-9 List of test procedures approved by U.S. EPA for
non-pesticide organic compounds E-58
E-10 List of test procedures approved by U.S. EPA for
pesticides E-60
E-ll Recommended sample sizes, containers, preservation,
and holding times for effluent samples . ; . . E-62
E-l2 Reported values for activated sludge biological process
tolerance limits of organic priority pollutants E-71
E-13 Reported values for activated sludge biological process
tolerance limits of inorganic priority pollutants E-73
E-vi
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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 requirements." These requirements
apply only to POTWs serving a population of at least 50,000 and only to toxic pollutants
introduped by industrial dischargers. For each toxic pollutant introduced by an industrial
discharger to an affected POTW, the applicant must demonstrate that it meets one of the
following two conditions:
• It has an "applicable pretreatment requirement in effect."
' j
• It achieves "secondary removal equivalency."
This new statutory requirement (§125.65) complements the toxics control program requirements
in the section 301 (h) regulations (§125.66) and other pretreatment requirements in 40 CFR Part
403.
The purpose of this appendix is to help 301(h) applicants 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 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 the urban area pretreatment requirements must
be formulated and implemented by each applicant with approval from (he appropriate EPA
Regional office. Compliance with the urban area pretreatment requirements is required before
a 301(h) modified permit can be issued by EPA, although tentative approval may be granted on
demonstration of the applicant's good faith effort to comply. !
When a review of the 301(h) application indicates noncompliance with pretreatment
requirements and shows that the applicant is not taking effective steps to ensure compliance, EPA
may deny the permit. Factors relevant to such a decision include the number of noncomplying
industrial sources, the nature of their toxic pollutant contribution to the POTW, and potential or
actual POTW interference or pass-through.
For urban area POTWs with significant numbers of industrial users., at any given tune it
is reasonable to expect that at least one or more of those users might be out of compliance. EPA
intends to determine a POTW's continuing eligibility for a 301(h) waiver under section 301(h)(6)
E-l
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by measuring industrial user compliance and POTW enforcement activities against existing
criteria in the Agency's National Pretreatment Program. In 1989, EPA established criteria for
determining POTW compliance with pretreatment implementation obligations. One element of
those criteria is the level of significant noncompliance of the POTW's industrial users. The
General Pretreatment Regulations (40 CFR Part 403) identify the circumstances when industrial
user noncompliance is significant. The industrial user significant noncompliance (SNC) criteria
are set out in 40 CFR 403.8(f)(2)(vii) and address both effluent and reporting violations.
In enforcing the pretreatment programs, POTWs are expected to respond to industrial user
noncompliance using local enforcement authorities in accordance with an approved enforcement
response plan (ERP), which is required of all approved pretreatment programs (see 40 CFR
403.5). POTWs, including 301(h) POTWs, with greater than 15 percent of their users in SNC,
or which fail to enforce appropriately against any single industrial user causing pass-through or
interference, are deemed to be failing to enforce their pretreatment programs. Thus, the POTW
is also deemed to be in SNC.
EPA will base its determination on data collected during site visits to the POTW and from
the POTW's pretreatment program performance report requked by 40 CFR 403.12(i). This report
includes compliance information on industrial users gathered by the POTW as well as a
description of the enforcement activities of the POTW. EPA believes that the combination of
industrial user compliance and POTW enforcement provides an appropriate measurement of the
POTW's eligibility for the 301(h) waiver under section 301(h)(6).
The process that an applicant must follow to achieve compliance is based on guidelines
established by EPA's pretreatment program. The U.S. EPA Office of Waste water Management
(OWM) and Office of Science and Technology (OST) have issued the following guidance
manuals to assist POTWs in implementing pretreatment regulations and developing technically
based local limits:
• Fate of Priority Toxic Pollutants in Publicly Owned Treatment Works (U.S. EPA
1982d);
• Guidance Manual for POTW Pretreatment Program Development (U.S. EPA
1983a);
« Procedures Manual for Reviewing a POTW Pretreatment Program Sub-
mission (U.S. EPA 1983b);
E-2
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NPDES Compliance Inspection Manual (U.S. EPA 1984a);
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 Wastestream Formula (U.S. EPA 1985b);
Pretreatment Compliance Monitoring and Enforcement Guidance (U.S. EPA
1986a);
Guidance Manual for Preventing Interference at POTWs (U.S. EPA 1987a);
Guidance for Reporting and Evaluating POTW 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);
Supplemental Manual on the Development and Implementation of Local
Discharge Limitations Under the Pretreatment Program: Residential and
Commercial Toxic Pollutant Loadings and POTW Removal Efficiency
Estimation (U.S. EPA 1991a); and
Training Manual for NPDES Permit Writers (U.S. EPA 1993a).
E-3
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CHARACTERIZATION OF DISCHARGE AND SELECTION OF APPROACH
Figure E-l presents an overview of the process and decision points that the applicant
should follow to comply with the urban area pretreatment requirements. Next to each step in the
process are page numbers indicating sections in this appendix that explain the procedures for that
step. Under the urban area pretreatment provisions, the applicant must select one of two basic
approaches to demonstrate compliance:
• The Applicable Pretreatment Requirement Approach or
• The Secondary Removal Equivalency (Pilot Plant) Approach.
Figure E-l presents the Applicable Pretreatment Requirement Approach in detail. Figures
illustrating the details of the Pilot Plant Approach will be presented later in this appendix. There
is a first step common to both approaches. Prior to making the selection, the applicant should
adequately characterize the industrial users discharging waste to the POTW, as well as conduct
representative sampling of the POTW influent, effluent, and sludge to identify any and all toxic
pollutants introduced by industrial sources.
INDUSTRIAL WASTE SURVEY
A comprehensive survey of industrial users is critical to characterizing the types and
concentrations of toxic pollutants being discharged to the POTW. All industrial users, including
major or significant industries (including categorical users) and minor industries, including
noncategorical users (small industries and some commercial users), should be included in the
industrial waste survey (IWS). A typical IWS may require submission of some or all of the
following information from each industrial user:
Name
" Address
Standard Industrial Classification (SIC) code
Wastewater flow
Types and concentrations of pollutants in discharge(s)
E-4
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Industrial User and
Influent/Effluent/Sludge
Characterizations
(PagesE-4toE-12)
(PagesE-14toE-31) (each toxic)
Applicable
Pretreatment s^ Secondary Removal
Requirement /.\ Equivalency (Pilot Plant)
Approach
Numeric &
Narrative
LL analysis
(Pages E-32 to E-74)
Monitoring; technical data
review; IMPs and other
pollution prevention practices
and annual report
(Type 3) j
(Pages E-30 to
E-31)
(Pages E-26 to E-29)
Monitoring;
technical data review;
and annual report
Yes
(Pages E-29 to E-30)
(Page E-30)
*Local limits can include numeric,
narrative, or a combination of both.
Figure E-l. Urban area pretreatment requirements.
E-5
-------
« Major products manufactured and/or services rendered
• Locations of discharge points
• Process diagram and/or descriptions
• An inventory of raw feedstocks, including periodically used solvents,
surfactants, pesticides, etc.
• Results of inspections, including documentation of spills, compliance history,
general practices
» Treatment processes and management practices, such as spill prevention plans
and solvent management plans, employed
• Discharge practices, such as batch versus continuous, variability in waste
constituent concentrations and types, discharge volume
• Pollutant characteristics data (i.e., including carcinogenicity, toxicity,
mutagenicity, neurotoxicity, volatility, explosivity, treatability,
biodegradability, bioaccumulative tendency).
It is likely that this information has already been developed as part of the POTW's
industrial pretreatment program. The IWS should be comprehensive and up-to-date, however,
at the time the 301 (h) application is submitted for review. Guidance on conducting an IWS is
provided in Chapter 2 of EPA's Guidance Manual for POTW Pretreatment Program
Development (U.S. EPA 1983a) and in Chapter 2 of Guidance on the Development and
Implementation of Local Discharge Limitations Under the Pretreatment Program (U.S. EPA
1987c). IWS data may be reviewed in conjunction with the pollutant occurrence matrix provided
in Table E-l. This table relates specific industries with the toxic pollutants commonly expected
to occur with them. Other sources of information that will aid the POTW in identifying
pollutants of concern are provided hi the EPA guidance manuals listed on pages E-2 and E-3.
A classification scheme should be developed to assist in establishing a monitoring plan
and conducting any local limits analyses. Industrial users can be initially grouped according to
the following three broad categories (U.S. EPA 1983a):
E-6
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Group 1: Major or significant industries, defined as: !
All categorical industrial users;
Noncategorical industrial users that discharge a nondonaestic waste
stream of 25,000 gallons per day (0.025 MOD) or more;
Noncategorical industrial users that contribute a nondomestic waste
stream that makes up 5 percent or more of the average dry-weather
hydraulic or organic (BOD, TSS, etc.) capacity of the treatment plant; or
Noncategorical industrial users that have a reasonable potential, in the
opinion of the POTW applicant, to adversely affect the POTW treatment
plant (inhibition, pass-through of toxic pollutants, sludge contamination,
or endangerment of POTW workers).
These industries would be regulated individually and would most likely have
specific effluent limitations (categorical standards, numeric local limits, or
both) placed on their discharges. They should also be moioitored and
inspected periodically to ensure compliance with their limitations.
Group 2: Minor industrial users, defined as small industries (all
noncategorical) and some commercial users (restaurants, auto repair shops,
car and truck washes, etc.), as well as any hauled waste ancl/or landfill
leachate, whose individual discharges are not likely to significantly impact
the POTW treatment system, degrade receiving water quality, or contaminate
sludge, but which have the potential as a group or as subgroups to represent
a significant source of toxic pollutants to the POTW. The E'OTW may
choose to apportion numeric local limits among minor industrial users when
these industries as a group represent a significant source of toxic pollutants
to the POTW; otherwise, the POTW should determine the need to set
narrative local limits, which may include industrial management practices and
best management practices (such as through a sewer ordinance or general
permit) to control and reduce levels of toxic pollutants.
Industries in this classification should be monitored and inspected
periodically to determine whether their status as minor industrial users has
changed. EPA's Supplemental Manual on the Development and
Implementation of Local Discharge Limitations Under the Pretreatment
Program: Residential and Commercial Toxic Pollutant Loadings and POTW
E-ll
-------
Removal Efficiency Estimation (U.S. EPA 1991a) provides data on toxic
pollutant types and levels for a variety of minor industrial users.
• Group 3: Insignificant industrial users, defined as those industries which do
not discharge to the POTW or do not have any reasonable likelihood of
discharging a nondomestic waste stream to the POTW. These industries
would be randomly monitored to ensure their status has not changed.
REPRESENTATIVE SAMPLING PROGRAM AT POTW
At this point the applicant must conduct sufficient monitoring at the treatment plant to
identify and characterize influent, effluent, and sludge concentrations of toxic pollutants.
Monitoring of the treatment plant influent, effluent, and sludge should represent a minimum of
5 consecutive days (Monday through Friday), preferably under dry weather conditions (U.S. EPA
1987c). Guidance on sampling techniques and QA/QC requirements are provided later in this
appendix. Results of these analyses, along with historic data (if available) and data and
information gathered during the IWS, should be tabulated in a summary form that allows the
toxic quality of the discharge to be evaluated. The applicant must report all toxic pollutants (40
CFR 401.15) that are identified in any analysis at or above detection limits in the influent,
effluent, and sludge as well as toxic pollutants known or suspected to be discharged by industry
to the POTW (based on historic data and information collected during the IWS). Sources of
detected and/or known or suspected toxic pollutants must be identified and, to the extent
practicable, categorized according to industrial and nonindustrial origins, using the results of the
IWS.
SELECTION OF APPROACH
Once the toxic pollutants being introduced by industrial sources have been identified, the
applicant can choose between two methods to comply with the urban area pretreatment
requirements for each toxic pollutant introduced by an industrial source. In the first method,
called the Applicable Pretreatment Requirement Approach, the applicant would demonstrate that
it has in effect applicable pretreatment requirements for each toxic pollutant discharged to the
POTW from an industrial source. Applicable pretreatment requirements may take the form of
(1) federal categorical pretreatment standards or (2) local limits developed in accordance with 40
CFR Part 403, or a combination of (1) and (2). A third applicable pretreatment requirement exists
where it is determined that local limits are not necessary for a toxic pollutant. In this case, the
POTW should implement a program of periodic monitoring and/or technical review of data on
E-12
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industrial discharges and require industrial management practices plans (IMPs) and other
pollution prevention practices where appropriate. The POTW should also determine on an annual
basis over the permit term the need to revise local limits and/or demonstrate that there is no need
for a local limit for each specific toxic pollutant.
lii the second method, called the Secondary Removal Equivalency Approach (Pilot Plant
Approach), the applicant would demonstrate that the POTW's treatment process, in combination
with pretreatment, removes at least the same amount of that toxic pollutant as would have been
removed by secondary treatment (as defined in 40 CFR Part 133) without industrial pretreatment
for that toxic pollutant. These methods are detailed in the following sections. The applicant
should review these procedures fully prior to selecting the method for addressing the urban area
pretreatment requirements for each toxic pollutant introduced by industrial discharges.
E-13
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APPLICABLE PRETREATMENT REQUIREMENT APPROACH
BACKGROUND AND GENERAL APPROACH
Applicable pretreatment requirements for each toxic pollutant may take the form of
categorical standards, local limits (numeric or narrative), or a combination of both. They should
include periodic monitoring and technical review of industrial discharges and POTW
influent/effluent/sludge to determine the need for revising local limits and/or to demonstrate that
there is no need for a local limit for a specific toxic pollutant. When an industrial discharger
is subject to both a categorical standard (Type 1) and a local limit for a specific toxic pollutant
(Type 2), the more stringent of the two limits applies. For toxic pollutants for which the POTW
determines that a local limit is not needed (Type 3), the POTW can show that it has an applicable
pretreatment requirement in effect by the following:
(1) Implement a periodic monitoring program and annual technical review of
industrial discharges.
(2) Institute industrial management practices plans (IMPs), best management
practices (BMPs), and other pollution prevention activities, where appropriate.
(3) Provide a determination on an annual basis of the need to develop local
limits and/or to demonstrate that there is no need for a local limit for those
toxic pollutants.
Categorical standards (see 40 CFR 403.6) are nationally uniform, technology-based limits
developed for specific industries and for specific toxic pollutants. 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,
among other purposes, to prevent interference with the treatment works or pass-through of toxic
pollutants, as required by 40 CFR 403.5(b).
A specific categorical industry may be subject to categorical standards for some pollutants
and local limits for other pollutants. When both local limits and categorical standards address
a particular pollutant for a specific industry, the more stringent requirement applies. Furthermore,
local limits for specific toxic pollutants found in the POTW waste stream can apply to both
categorical and noncategorical industries when the toxic pollutants cannot be entirely attributed
E-14
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to categorical industries and/or when categorical standards alone are not sufficient to satisfy the
requirements of 40 CFR Part 403.
Local limits (see 40 CFR 403.5) 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 that could interfere with POTW treatment processes
or pass through the treatment plant to receiving waters and adversely affect water quality. Local
limits are also designed to prevent sludge contamination and protect workers at the treatment
POTW.
Under the Applicable Pretreatment Requirement Approach, the applicant must address
each toxic pollutant introduced by industry. After conducting a local limits sinalysis, the POTW
may apportion the allocation of the numeric local limit (if any) to any number of industrial
sources of the toxic pollutant (categorical and/or noncategorical) that the POTW deems
appropriate, subject to the approval of the applicable EPA Regional office. Moreover, when it
is not appropriate or practical to develop and implement numeric local limits to prevent pollutant
pass-through or interference, the EPA pretreatment program has provided for narrative local
limits (i.e., industrial management and best management practices) as useful supplements to
numeric limits. Narrative local limits are most appropriate where management plans are needed
to help control or eliminate chemical spills or leaks, slug discharges, or the handling of hazardous
or toxic materials from both categorical and noncategorical industries. \
For toxic pollutants for which the POTW determines that neither numeric nor narrative
local limits are necessary (e.g., categorical or noncategorical industries where not all toxic
pollutants discharged require a categorical standard or local limit), a program of periodic POTW
monitoring and annual technical review of data on industrial discharges would be conducted by
the POTW and, where appropriate, would include industrial management practices plans (IMPs)
and other pollution prevention activities. The permit for this latter case will nsquire the applicant
to demonstrate on an annual basis over the permit term that a local limit is not necessary and
where appropriate will require the applicant to institute IMPs. If such monitoring and technical
review of data indicate that a local limit is needed, the POTW shall establish and implement a
local limit.
1 I
I
IMPs are intended to minimize the discharge of toxic pollutants to the sewer, or reduce
the impact of toxic pollutant discharges by avoiding short-term, high-concentration discharges.
IMPs can be applied to all classes of industrial users, e.g., major and minor industrial users.
Examples of appropriate uses of IMPs include control of chemical spills and slug discharges to
E-15
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the POTW through formal chemical or waste management plans (including BMPs), solvent
management plans, batch discharge policies, waste recycling, and waste minimization. It would
also be appropriate to consider IMPs in cases where the POTW does not include biological
treatment processes, or provides less treatment, e.g., primary treatment. In these cases, IMPs can
be tailored for industrial sources of toxic pollutants that might otherwise interfere with biological
treatment or would be degraded or removed through additional treatment.
POTWs must demonstrate that the local limits developed are adequate and enforceable.
Section 301(h)(6) and §125.65(b)(2) also require 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 (see previous discussion regarding
compliance and enforcement).
U.S. EPA PROCEDURES FOR DEVELOPING TECHNICALLY BASED LOCAL LIMITS
Details on the various approaches for developing technically based local limits are
provided in U.S. EPA's Guidance Manual on the Development and Implementation of Local
Discharge Limitations Under the Pretreatment Program (December 1987) (hereafter called
"EPA's Local Limits Guidance"). Questions about this guidance should be directed to the U.S.
EPA Regional Pretreatment Coordinators or to EPA's Office of Wastewater Management hi
Washington, DC.
Several methods are available to develop local limits, including the Maximum Allowable
Headworks Loading (MAHL) Method, the Collection System Approach, Industrial User
Management Practice Plans, and Case-by-Case Permitting (U.S. EPA 1987c). The Collection
System Approach is most appropriate to address pollutants that may cause air releases or
explosive conditions or may otherwise endanger POTW worker health and safety. Case-by-Case
Permitting is based on best professional judgment and is most appropriate where data on pollutant
effects are insufficient to use other methods (e.g., the MAHL method or Collection System
Approach). It largely relies on pollutant removal efficiencies and economic achievability data
for pollution control from comparable industries/discharges.
The predominant approach used by POTWs and advocated in EPA's Local Limits
Guidance is a chemical-specific approach known as the Maximum Allowable Headworks Loading
(MAHL) Method. This method involves back-calculating from environmental and plant
protection criteria to a maximum allowable headworks loading. This is accomplished pollutant
by pollutant for each environmental criterion or plant requirement, and the lowest or most
E-16
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limiting value for each pollutant serves as the basis for allocation to industry and ultimate
numeric local limits. Industrial User Management Practices Plans may be used in conjunction
with the MAHL method through narrative local limits to address toxic pollutants and/or industries
for which numeric local limits may not be applicable or adequate alone to achieve control of
toxic chemical discharges. Narrative local limits may be required because the nature of the
industrial activity (slug discharges, chemical handling, etc.) requires pollution prevention
activities to ensure adequate control of accidental or haphazard toxic chemical releases. Narrative
local limits are discussed later and in Attachment 1 to this appendix. The steps of the MAHL
method .are discussed below.
i
Maximum Allowable Headworks Loading Method
a) Determine Pollutants of Concern (U.S. EPA 1987c)~
.
The first step of the MAHL method is to determine the pollutants of concern. Prior to
this step, the applicant will have completed the IWS and will have identified the toxic pollutants
that its industrial users are reasonably expected to be discharging to the POTW. The applicant
should then design a sampling and monitoring program that is thorough enough to verify the
actual concentration levels of toxic pollutants expected to be discharged in significant quantities
and broad enough to detect any toxic pollutants that were not detected by the IWS or
representative sampling activities. Before designing the sampling program, the POTW may want
to review environmental quality criteria/effects data for pollutants that are potentially of concern
(U.S. EPA 1987c). The applicant should perform at least one priority pollutant scan and one
RCRA Appendix 9 scan (refer to Tables E-2 and E-3, respectively) to identify potential pollutants
of concern in the influent, effluent, and sludge.
Figure E-2 is a detailed decision diagram of one possible approach for determining
pollutants of concern that may require numeric local limits through the MAHL method (U.S.
EPA 1987c). This approach is based primarily on analysis of the POTW's influent, with limited
effluent'and sludge sampling to screen for pollutants that may not be detectable in the influent
but may have been concentrated in the effluent or sludge. Figure E-2 provides a series of
reference levels that POTWs can use in assessing influent wastewater data and determining the
need to proceed with a headworks analysis. These reference levels, provided as guidance for
each of Ithe protection criteria, are intended to be conservative in order to account for the daily
fluctuations in pollutant loadings experienced by POTWs and for the fact that decisions are
usually made on the basis of limited data. The reason for emphasizing the us:e of influent data hi
this example in which only limited effluent and sludge data are used is to conserve resources
E-17
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TABLE E-2. LIST OF PESTICIDES AND TOXIC POLLUTANTS
Pesticides
Demeton
Guthion
Malathion
Methoxychlor
Mirex
Parathion
Toxic Pollutants'
Chlorinated Benzenes
Chlorobenzene
1,2-Dichlorobenzene
1,3-Dichlorobenzene
1,4-Dichlorobenzene
1,2,4-Trichlorobenzene
Hexachlorobenzene
Chlorinated Ethanes
Chloroethane
1,1 -Dichloroethane
1,2-Dichloroethane
1,1,1-Trichloroethane
1,1,2-Trichloroethane
1,1,2,2-Tetrachloroethane
Hexachloroethane
Chlorinated Phenols
2-Chlorophenol
2,4-Dichlorophenol
2,4,6-Trichlorophenol
4-Chloro-3-methyl phenol
Other Chlorinated Organics
Chlorofonn (trichloromethane)
Carbon tetrachloride (tetrachloromethane)
bis(2-chloroethoxy)methane
bis(2-chloroethyl)ether
2-Chloroethyl vinyl ether (mixed)
2-Chloronaphthalene
3,3-Dichlorobenzidine
1,1-Dichloroethylene
trans-1,2-dichloroethylene
1,2-Dichloropropane
1,2-Dichloropropylene (1,3-dichloropropene)
Tetrachloroethylene
Trichloroethylene
Vinyl chloride (chloroethylene)
Hexachlorobutadiene
2,3,7,8-Tetrachloro-dibenzo-p-dioxin(TCDD)
Haloethers
4-Chlorophenyl phenyl ether
2-Bromophenyl phenyl ether
bis(2-Chloroisopropyl) ether
Halomethanes
Methylene chloride (dichloromethane)
Methyl chloride (chloromethane)
Methyl bromide (bromomethane)
Bromoform (tribromomethane)
Dichlorobromomethane
Chlorodibromomethane
Nitrosamines
N-Nitrosodimethylamine
N-Nitrosodiphenylamine
N-Nitrosodi-n-propylamine
Phenols (other than chlorinated)
2-Nitrophenol
4-Nitrophenol
2,4-Dinitrophenol
4,6-Dinitro-o-cresol (4,6-dinitro-2-
methylphenol)
Pentachlorophenol
Phenol
2,4-dimethylphenol
Phthalate Esters
bis(2-Ethylhexyl)phthalate
Butyl benzyl phthalate
Di-n-butyl phthalate
Di-n-octyl phthalate
Diethyl phthalate
Dimethyl phthalate
Polynuclear Aromatic Hydrocarbons (PAHs)
Acenaphthene
1,2-Benzanthracene (benzo(a)anthracene)
3,4-Benzo(a)pyrene (benzo(a)pyrene)
E-18
-------
TABLE E-2. (Continued)
PAHs (continued)
3,4-Benzofluoranthene (benzo(b)fluoranthene)
11,12-Benzofluoranthene (benzo(k)
flupranthene)
Chrysene
Acenaphthalene
Anthracene
1,12-Benzoperylene (benzo(g,h,i)perylene)
Fluorpne
Fluoranthene
Phenanthrene
1,2,5,6-Dibenzanthracene (dibenzo(a,h)
anthracene)
Indeno(l,2,3-cd)pyrene (2,3-o-phenylene
pyrene)
Pyrene
Pesticides; and Metabolites
Aldrin
Dieldrin
Chlordane (technical mixture and metabolites)
alpha^Endosulfan
beta-Endosulfan
Endosulfan sulfate
Endrin
Endrin aldehyde
Heptachlor
Heptachlor epoxide (BHC-
hexachlorocyclohexane)
alpha-BHC
beta-BHC
gamma-BHC (Lindane)
delta-BHC
Toxaphene
DDT and Metabolites
4,4-DpT
4,4-DDE (p,p-DDX)
4,4-DDD (p.p-TDE)
Polychlorinated Biphenyls (F'CBs)
PCB-1242 (Arochlor 1242)
PCB-1254 (Arochlor 1254)
PCB-1221 (Arochlor 1221)
PCB-1232 (Arochlor 1232)
PCB-1248 (Arochlor 1248)
PCB-1260 (Arochlor 1260)
PCB-1016 (Arochlor 1016)
Other Organies
Acrolein !
Acrylonitrile
Benzene
Benzidine
2,4-Dinitrotoluene
2,6-Dinitrotoluene
1,2-Diphenylhydrazine
Ethylbenzene
Isophorone
Naphthalene
Nitrobenzene i
Toluene
•
Inorganics
Antimony
Arsenic
Asbestos I
Beryllium
Cadmium
Chromium
Copper
Cyanide, total
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
"Source: U.S. EPA 1993b.
E-19
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TABLE E-3. RESOURCE CONSERVATION AND RECOVERY ACT (RCRA)
APPENDIX 9 CONSTITUENTS
Acenaphthene
Acenaphthylene
Acetone
Acetonitrile
2-Acetylaminofluorene
Acrolein
Acrylonitrile
Aldrin
alpha-BHC
4-Aminobiphenyl
Aniline
Anthracene
Antimony (6010)
Aramite
Arsenic (7061)
Barium (6010)
Benzene
Benzo[a]anthracene
Benzo[a]pyrene
Bcnzo[b]fluoranthene
Benzo[g,h,i]perylene
Benzo[k] fluoranthene
Benzyl alcohol
Beryllium (6010)
beta-BHC
bis(2-Chloroethoxy)methane
bis(2-Chloroethyl)ether
bis(2-Chloroisopropyl)ether
bis(2-Ethylhexyl)phthalate
Broraodichloromethane
Bromoform
Bromomethane
4-Bromophenyl phenyl ether
Butyl benzyl phthalate
2-sec-Butyl-4,6-dinitrophenol
Cadmium (6010)
Carbon disulfide
Carbon tetrachloride
4-Chlorophenyl phenyl ether
Chlordane
2-Chloro-l,3-butadiene
p-Chloro-m-cresol
p-Chloroaniline
Chlorobenzilate
Chlorodibromomethane
Chlorobenzene
Chloroethane
Chloroform
2,4-DunethylphenoI
4,6-Dinitro-o-cresol
Chloromethane
2-Chloronaphthalene
2-Chlorophenol
3-Chloropropene
Chromium (6010)
Chrysene
Cobalt (6010)
Copper (6010)
o, m, p-Cresol
Cyanide (9010)
2,4-D
4,4-DDD
4,4-DDE
4,4-DDT
Di-n-butyl phthalate
Di-n-octyl phthalate
Di-n-propylnitrosamine
Diallate
Dibenzofuran
Dibenz[a,h]anthracene
1,2-Dibromo-3-chloropropane
Dibromoethane
Dibromomethane
trans-1,4-Dichloro-2-butene
3,3-Dichlorobenzidine
m-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
Dichlorodifluoromethane
1,1 -Dichloroethane
1,2-Dichloroethane
trans-1,2-Dichloroethene
1,1 -Dichloroethylene
Dichloromethane
2,4-Dichlorophenol
2,6-Dichlorophenol
1,2-Dichloropropane
cis-1,3-Dichloropropene
trans-1,3-Dichloropropene
Dieldrin
Diethyl phthalate
Dimethoate
3,3-Dimethyl benzidine
Dimethyl phthalate
p-(Dimethylamino)azobenzene
7,12-Dimethylbenz[a]anthracene
a,a-Dimethylphenethylamine
m-Dinitrobenzene
2,4-Dinitrophenol
2,4-Dinitrotoluene
2,6-Dinitrotoluene
1,4-Dioxane
Diphenylamine
Disulfoton
Endosulfan I
Endosulfan sulfate
Endosulfan II
Endrin
E-20
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TABLE E-3. (Continued)
Endrin aldehyde
Ethyl benzene
Ethyl cyanide
Ethyl me'thacrylate
Ethyl methanesulfonate
Famphur
Fluoranthene
Fluorene
Heptachlor epoxide
Heptachlor
Hexachlorobutadiene
Hexachlorocyclopentadiene
Hexachloroethane
Hexachloropropene
Hexachlorophene
2-Hexanone
Hexchlorobenzene
Indeno(l ,2,3-cd)pyrene
Isobutyl alcohol
lodomethane
Isodrin
Isophorone
Isosafrole
Kepone ;
Lead (7421)
Lindane
Mercury: (7470)
Methacrylonitrile
Methapyrilene
Methoxychlor
Methyl parathion
Methyl ethyl ketone
Methyl methanesulfonate
Methyl methacrylate
4-Methyl-2-pentanone
3-Methylcholanthrene
2-Methylnaphthalene
Naphthalene
1,4-Naphthoquinone
1-Naphthylamine
2-Naphthylamine
Nickel (6010)
o-Nitroaniline
5-Nitro-o-toluidine
m-Nitroaniline
p-Nitroaniline
Nitrobenzene
o-Nitrophenol
p-Nitrophenol
4-Nitroquinoline-1 -oxide
N-Nitrosodi-n-butylamine
N-Nitrosbdimethylamine
N-Nitrospdiethylamine
N-Nitrosbdiphenylamine
N-Nitrosomethylethylamine
N-NitrosomorphoUne
N-Nitrosopiperidine
N-NitroSopyrroIidine
Parathion i
PCBs !
Pentachlorobenzene
Pentachloroethane
Pentachloronitrobenzene
Pentachlorophenol |
Phenacetin
Phenanthrene
Phenol ,
p-Phenylenediamine
Phorate !
2-Picoline
Polychlorinated Dibenzofuran« (PCDFs)
Polychlorinated Dibenzo-p-dicixins (PCDDs)
Pronamide
Pyrene
Pyridine
Safrole
Selenium (7741)
SEver (6010)
Styrene |
Suffide (9030)
2,4,5-T
2,3,7,8-TCDD
1,2,4,5-Tetrachlorobenzene
1,1,1,2-Tetrachloroethane ;
1,1,2,2-Tetrachloroethane i
Tetrachloroethene
2,3,4,6-Tetrachlorophenol !
Tetraethyldithiopyrothosphate
ThaUium (7841)
Thionazin ]
Tin (6010) |
Toluene
o-Toluidine
Toxaphene
2,4,5-TP (Silvex)
1,2,4-Trichlorobenzene
1,1,1-Trichloroethane
1,1,2-Trichloroethane
Trichloroethene
Trichlorofluoromethane
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
1,2,3-Trichloropropane
O,O,O-Triethyl phosphorothioate
sym-Trinitrobenzene
Vanadium (6010)
Vinyl Chloride
Vinyl Acetate
Xylene
Zinc (6010) I
Source: 40 CFR Part 264T
E-21
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E-22
-------
during the preliminary screening and allow more resources to be used for the detailed headworks
analysis of specific pollutants. The need to proceed with a headworks analysis for particular
pollutants is indicated when:
n The maximum concentration of the pollutant in the POTW's effluent is more
than one-half the allowable effluent concentration required to meet water
• quality criteria/standards or the maximum sludge concentration is more than
one-half the applicable sludge criteria guidelines or
V The maximum concentration of the pollutant in a grab sample from the
1 POTW's influent is more than half the inhibition threshold or the maximum
concentration of the pollutant in a 24-hour composite sample from the
, POTW's influent is more than one-fourth the inhibition threshold.
1
• i
• The maximum concentration of the pollutant in the POTW's influent is more
than l/500th of the applicable sludge use criteria [with the use of a
"l/500th" reference level being suggested based on a review of POTW data
(Fate of Priority Toxic Pollutants in Publicly Owned Treatment Works, U.S.
EPA 1982d) indicating that a 500-fold concentration of pollutants can occur
in digested sewage sludges as compared to the wastewater influent to the
treatment plant] or
• ,
• The concentration of the pollutant in the plant influent exceeds water quality
criteria adjusted through a simple dilution analysis. j
Decisions as to whether to conduct a detailed headworks loading analysis are represented
by the diamonds in Figure E-2. If a pollutant level exceeds the reference levels, the POTW
should conduct a detailed headworks loading analysis for that pollutant to assess whether a
numeric and/or narrative local limit is needed. The headworks loading analysis should be based
on comprehensive influent, effluent, and sludge sampling and industrial contribution as discussed
in the following section. If the reference-level analysis above does not point to the need for a
detailed headworks loading analysis, the POTW should evaluate the need to set narrative limits
(i.e., industrial management practices plans and best management practices) to control and reduce
levels of these toxic pollutants from industrial sources, and determine on an annual basis the need
to revise local limits and/or to demonstrate that there is no need for a local limit for a specific
toxic pollutant.
E-23
-------
Furthermore, for toxic pollutants for which the POTW determines [after completing the
IWS, screening analysis, and MAHL (if applicable)] that neither numeric nor narrative local
limits are necessary (e.g., insignificant industrial contribution), a program of periodic POTW
monitoring and annual technical review of data on industrial discharges would be conducted by
the POTW and, where appropriate, would require industrial users to institute industrial
management practices plans and other pollution prevention activities. For these toxic pollutants,
the POTW would report annually to EPA on the status of the need for development of local
limits. (For further discussion of these requests, see section below entitled Ongoing Analysis of
Other Toxic Pollutants Not Addressed by Local Limits).
b) Characterize Existing Loadings (U.S. EPA 1987c)--
rndustrial 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 is especially important where a discharge makes up a large percentage of
the total industrial pollutant loading to the system, or when toxic pollutants are known or
suspected to be discharged in large quantities or concentrations. This loading characterization
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 determination 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. Treatment plant influent
and effluent sampling must be conducted to obtain data for use in calculating overall POTW
removal efficiencies. The POTW should also monitor its sludge at the influent to the sludge
digesters and at the point of disposal of the processed sludge. The resulting sludge monitoring
data are used to derive digester removal efficiencies and sludge partitioning constants necessary
for converting of sludge disposal criteria/standards and digester inhibition threshold data into
E-24
-------
corresponding headworks loadings. Specific guidance on sludge sampling and analysis can be
found in POTW Sludge Sampling and Analysis Guidance Document (U.S. EPA 1989).
The initial monitoring program should include (as a minimum) at least 5 consecutive days
of sampling for both metals and toxic organics. A minimum of 5 consecutive days (Monday
through Friday) is necessary to adequately characterize the typical short-term range and
variability in toxic quality of the POTW and industrial user wastewater discharge activity.
Preferably, longer-term monitoring should also be conducted to include data for at least 1 day
of sampling per month over at least 1 year for metals and other inorganic pollutants and 1 day
of sampling per year for toxic organics to assess long-term variations in wasitewater composition.
To ensure valid data, representative measurements of flow rates must be taken at the point and
time of isample collection. Flow measurements and sampling can be conducted either manually
or with automatic devices.
The method for analysis of a toxic pollutant should be selected according to the type of
pollutant to be analyzed (i.e., grab samples over 24 hours for volatile organic compounds, total
recoverable phenolic compounds, and cyanide and flow-proportioned 24-hour composite samples
for all other toxic pollutants). Guidance on sampling techniques and QA/QC requirements are
provided later in this appendix.
c) Determine Applicable Environmental Criteria (U.S. EPA 1987c)~
Environmental criteria usually include NPDES 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 EPA's Local Limits Guidance.
Another environmental criterion is biological toxicity of whole effluents. POTWs that
have conducted biological toxicity testing indicating toxicity of whole effluents should develop
local limits to correct the toxicity. Although there is no method in EPA's Local Limits Guidance
for calculating 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. (Also, refer to U.S. EPA 1988 and U.S. EPA 1991b for additional information.)
E-25
-------
d) Calculate Maximum Headworks Loadings (U.S. EPA 1987c)-
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. Figure E-3
presents the formulas and data elements necessary to perform these calculations. In addition,
Attachment 2 to this appendix presents a sample local limits headworks loading calculation. 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 EPA's Local Limits Guidance.
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 determined 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.
e) Calculate Allowable Industrial Loadings (U.S. EPA 1987c)-
Once the POTW has calculated the maximum allowable headworks loading, a safety
factor must be applied and the value discounted for domestic/background 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 discrepancies
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.
f) Allocate Allowable Industrial Loading (allocation of local limits) (U.S. EPA 1987c)~
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
E-26
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In-Plant Criterion
NPDES permit limit
Water quality standard
Secondary treatment (e.g., activated sludge)
threshold inhibition level
Tertiary treatment (e.g., nitrification)
threshold inhibition level
Sludge digester threshold inhibition level
Sludge disposal criterion/standard
Mass Balance Equation
_ (8.34)(Ccm)(gfOJW)
-'IN
-"IN
TR
^ P
where:
•'-'INF
CRIT =
CSLCRIT =
QPOTW =
RPOTW =
QSTR =
CSTR =
PRIM
R
RSEC
QDIG
QDISP
PS
Allowable influent loading, Ib/day
In-plant criterion, mg/L
Sludge disposal criterion/standard, mg/kg dry sludge
POTW flow, millions of gallons per day (mgd)
Removal efficiency across POTW, as a decimal
Receiving stream (upstream) flow, mgd
Receiving stream background level, mg/L
Receiving stream water quality standard, mg/L
Removal efficiency across primary treatment, as a decimal
Removal efficiency across secondary treatment, as a decimal
Sewage sludge flow rate to digester, mgd
Sewage sludge flow rate to disposal, mgd
Percent of sludge to disposal
Uniform concentration local limits can be derived through the use of the following equation:
(1-fflOtf-J-L.
''DOM
"UM
(8.34)02™,)
where:
Q.IM
MN '
SF
IND
Uniform concentration local limit, mg/L
Maximum allowable influent loading, Ib/day
Safety factor, as a decimal •
Loading for domestic/uncontrollable sources, Ib/day
Total industrial flow, mgdlevel). The discharge limit derived is applied only to those
industrial users which contribute the pollutant.
Figure E-3. Equation for deriving allowable POTW influent loadings from in-plant criteria.
E-27
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current loading of a pollutant exceeds the MAHL, the POTW must establish a numeric local limit
to reduce loadings to within the range of the MAHL. Where the current loading is below the
MAHL, the POTW is encouraged, but not required, to set industrial discharge limits at current
loadings to provide a safety factor.
A variety of procedures for the allocation of the allowable industrial loading exist. The
four allocation methods most frequently used by POTWs are:
• Uniform concentration — The MAHL for each pollutant is divided by the
total flow for all industrial users (even those which do not discharge the
pollutant). The resultant discharge concentration for each pollutant is applied
to all industrial user discharges.
» Concentration based on industrial contributory flow — The MAHL for each
pollutant is divided by the flow from only those industrial users which
actually have the pollutant in their untreated wastewaters (in concentration
greater than the background concentration.
• Mass production — The ratio of the MAHL to the current loading for each
industrial user contributing a particular pollutant is calculated, and the mass
loading limit is derived by multiplying this ratio by the industry's current
pollutant loading. The limit derived is unique for each industry, and limits
are developed and applied only to industries that contribute the pollutant.
• Selected industrial reduction — Individual pollutant loading reductions for
each industry are determined; typically the loading reductions are based on
the treatability of the industrial wastewater for each pollutant.
The POTW should ensure that it has selected local limits that are reasonable (i.e., they
incorporate appropriate safety factors, account for domestic/background loadings, and consider
appropriate environmental and plant protection criteria). All numeric 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. Under the
applicable pretreatment requirement approach, the applicant must address each toxic pollutant
introduced by industry. After conducting the local limits analysis, the POTW may allocate the
allowable industrial loading among any number of industrial sources of the toxic pollutant
(categorical and/or noncategorical) that the POTW deems appropriate, subject to the approval of
E-28
-------
the applicable EPA Regional office. Local limits could be allocated, for example, according to
the classification scheme developed under the industrial waste survey. For the major or
significant industries, the POTW would most likely set specific effluent limitations (categorical
standards, numeric local limits, or both). For the minor industries, the POTW may choose to
apportion numeric local limits among minor industrial users when these industries as a group
represent a significant source of toxic pollutants to the POTW; otherwise, the POTW should
determine the need to set narrative local limits (i.e., industrial management practice plans and
best management practices; see Attachment 1 to this appendix) where appropriate to control and
reduce Iqvels of toxic pollutants. Narrative local limits may also be implemented in conjunction
with numeric local limits for the same industry, if deemed appropriate.
i
If the initial screening process described in step (a) of the MAHL process (see Figure E-2)
does not point to the need for a detailed headworks loading analysis for a specific toxic pollutant,
the POTW should evaluate the need to set narrative local limits (i.e., industrial management
practices plans and best management practices) where appropriate to control and reduce levels
of these toxic pollutants from selected industries. Guidance on how to identify industries for
which narrative local limits may be appropriate is given in Attachment 1 to this appendix.
Once local limits have been developed for a toxic pollutant (numeric, narrative, or a
combination of both), they must be effectively implemented. Local limits should be incorporated
into the sewer use ordinance or some form of individual control mechanism.
i
g) Ongoing Review/Revision of Local Limits (numeric/narrative)(U.S. EPA 1987c)~
I
Local limits must be revised on a periodic basis to reflect changes in conditions or
assumptions. Conditions that might require that local limits be revised include, but are not
limited to, changes in environmental criteria, changes in the industrial users, availability of
additional monitoring data, changes in plant processes, and changes in POTW capacity or
configuration.
For those toxic pollutants for which numeric or narrative local limits were developed
through the MAHL analysis (or other method as appropriate), the POTW must demonstrate to
EPA on an annual basis, through annual monitoring and appropriate technical review of data on
discharges from industrial sources, that levels of these toxic pollutants in the POTW influent do
not exceed the maximum allowable headworks loading (MAHL) determined: in the analysis of
local limits described above. Annual monitoring should follow the guidelines discussed
previously hi this appendix for long-term treatment plant monitoring.
E-29
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The results of the monitoring and data review must be made available in the annual report
required under 40 CFR 403.12. If the POTW determines, based on results of annual monitoring
of the POTW influent/effluent/sludge and/or technical review of data on discharges from
industrial sources (also updated annually), that the level of a toxic pollutant is expected to exceed
the maximum allowable level determined through the local limits analysis, the POTW should
modify the local limit and the individual control mechanism or sewer use ordinance, as
appropriate, to implement the new local limit. Furthermore, the POTW should update the initial
screening of toxic pollutants based on results of the same technical review to determine the need
for inclusion of any new toxic pollutants/industries in the local limits analysis (either numeric or
narrative).
Ongoing Analysis of Other Toxic Pollutants Not Addressed by Local Limits
For those toxic pollutants which the POTW determines that neither numeric nor narrative
local limits are necessary (e.g., insignificant industrial contribution) the POTW must continue to
conduct periodic monitoring of the POTW influent and effluent and conduct annual technical
reviews of data on discharges from industrial sources during the term of the permit, to determine
any change in status of the toxic quality of the POTW wastewater and industrial sources.
Further, where appropriate the POTW should require industrial users to institute industrial
management practices plans (IMPs) and other pollution prevention activities such as through
individual control mechanisms or local sewer ordinances, to reduce or control the levels of these
toxic pollutants from industrial sources. These plans and activities could include best
management practices (BMPs). For more information, see Attachment 1 to this appendix and
EPA's Guidance Manual on the Development and Implementation of Local Discharge Limitations
Under the Pretreatment Program (U.S. EPA 1987c) and Supplemental Manual on the
Development and Implementation of Local Discharge Limitations Under the Pretreatment
Program: Residential and Commercial Toxic Pollutant Loadings and POTW Removal Efficiency
Estimation (U.S. EPA 1991a). If such monitoring and technical review of data indicate that a
local limit is needed, the POTW would establish and implement a local limit. The monitoring
program should follow the guidelines discussed previously in this appendix.
The basic philosophy of instituting management practices (IMPs) is to minimize the
discharge of toxic or hazardous pollutants to the sewer, or reduce the impact of toxic/hazardous
pollutant discharges by avoiding short-term, high-concentration discharges. Examples of
appropriate uses of IMPs include the control of chemical spills and slug discharges to the POTW
through formal chemical or waste management plans, including BMPs, solvent management
plans, batch discharge policies, waste recycling, and waste minimization. It would also be
E-30
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appropriate to consider IMPs in cases where the POTW does not include biological treatment
processes, or provides less treatment, e.g., primary treatment. In these cases, IMPs can be
tailored for industrial sources of toxic pollutants that might otherwise interfere with biological
treatment or would be degraded or removed through additional treatment.
E-31
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SECONDARY REMOVAL EQUIVALENCY APPROACH
The second approach that 301 (h) applicants may use to satisfy the new urban area
pretreatment requirements is to demonstrate secondary removal equivalency. As noted in
§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- determination 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 §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.
To demonstrate secondary removal equivalency, an applicant would need to use a
secondary treatment pilot plant. By diverting part of its primary effluent (secondary influent) to
the pilot plant (see Figure E-4), the applicant would empirically determine the incremental
amount of each toxic pollutant that would be removed from the primary effluent (secondary
influent) if secondary treatment were applied. Having determined the amount of each toxic
pollutant removed, the applicant would then demonstrate that its existing less-than-secondary
treatment plus existing industrial pretreatment removes at least the same amount of each toxic
pollutant as did the secondary treatment pilot plant (including removals in the primary effluent)
without any industrial pretreatment.
Figure E-4 schematically represents how the secondary removal equivalency test would
work for a POTW that has an existing industrial pretreatment program. Toxic pollutant scans
would be conducted on the effluent from the existing POTW (SCAN El) and from the secondary
pilot plant (SCAN E2). To achieve secondary removal equivalency for a toxic pollutant, the
following must hold:
El concentration
E2 concentration
E-32
-------
-o
§
8 o
G
1/3 .55
Figure E-4. Secondary pilot plant demonstration.
E-33
-------
The above relationship is equivalent to the following, restated in terms of removals of a toxic
pollutant:
Removals by Existing Treatment
Removals by Secondary Treatment (and no
industrial pretreatment)
removals by any
existing industrial
pretreatment*
removals by existing
primary and any
existing additional
POTW treatment
removals by any
existing POTW
primary treatment
removals by
secondary pilot
plant treatment
(scaled up)
If the POTW is able to estimate the amount of a toxic pollutant removed by its existing
industrial pretreatment (*), then secondary equivalency demonstration using the above formula
is straightforward. In many instances, however, the POTW will not have the necessary data with
which to estimate removals of toxic pollutants by existing industrial pretreatment. In those
instances, the above equation is revised as follows:
Removals by Existing Treatment
Removals by Secondary Treatment (with existing industrial
pretreatment)
removals by
any existing
industrial
pretreatment
removals by
existing primary
.{. and any >
existing
additional
POTW
treatment
removals by
any existing
industrial
pretreatment
removals by
any existing
POTW +
primary
treatment
removals by
secondary
pilot plant
treatment
(scaled up)
Ideally the (*) term should not appear on the right side of the equation, but this cannot
be avoided unless the POTW can factor out this term by knowing, through independent means
(e.g., a rigorous industrial wastewater pretreatment survey) the amount of a toxic pollutant
removed by existing industrial pretreatment. Otherwise, the POTW may choose to perform the
empirical (pilot plant) secondary removal equivalency demonstration using influent that has been
subject to that existing industrial pretreatment. Such a demonstration may then be conservative
because it may overstate the amount of toxic pollutant that would be removed by applying only
primary and secondary treatment.
If the POTW's above demonstration fails to demonstrate attainment of secondary removal
equivalency, then the POTW must evaluate the need for additional industrial pretreatment,
additional POTW treatment, or a combination of the two to achieve the necessary additional
removals, as defined in the revised equation shown below:
E-34
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Removals by Existing Plus Any New Additional
Treatment
Removals by Secondary Treatment (with
existing industrial pretreatment)
removals by any
existing industrial
pretreatment
removals by
existing primary
and any existing
additional POTW
treatment
+ new additional
pretreatment
**
+ new additional
POTW treatment
removals
by any
existing
industrial
pretreat-
ment
removals
4. ty any
existing
POTW
primary
treatment
removals by
_j_ secondary
pilot plant
treatment
(scaled up)
**
The "new" removals shown on the left side of the equation (**) represent additional future
removals by any new industrial pretreatment or new POTW treatment added to achieve secondary
equivalency. The applicant will be required to develop effluent limits based, on data from, the
secondary removal equivalency demonstration when these values are more stringent than effluent
limits based on state water quality standards or water quality criteria or will, be required to ensure
that all applicable environmental protection: .criteria are met. Once the effluent limits are
established, the applicant may either develop local limits (as described earlier) or perform
additional treatment at the POTW, or combine the two to achieve the permit limit.
I 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 .sepondary 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 CER Part 133 (Table E-4). 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-4.
" ' .-'-"'••» |
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
E-35
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TABLE E-4. EFFLUENT WATER QUALITY VALUES THAT SHALL NOT
BE EXCEEDED UNDER SECONDARY TREATMENT
Variable"
BOD5
CBOD5b .
SS
PH
30-Day
Average
30mg/L
25 mg/L
30mg/L
6.0 to
7-Day .
Average
45 mg/L
40 mg/L
45 mg/L
9.0
30-Day Average
(Percent Removal)
>85
>85
. >85
*BODS - 5-day measure of biochemical oxygen demand; CBOD5 = 5-day measure of carbonaceous biochemical oxygen demand; SS =
suspended solids.
kAt the option of the NPDES permitting authority, CBOD5 may be substituted for BOD5.
controlled predominantly through pretreatment programs, categorical standards, and local POTW
limits required by the issuance of NPDES permits. >
SECONDARY TREATMENT PILOT PLANT DESIGN CRITERIA
A secondary treatment pilot plant should be designed for an average flow of approxi-
mately 150 GPD. The flow rate should remain constant over a 24-hour period. The pilot plant
should requke minimum operation and maintenance time and must be able to operate unattended
for 16-24 hours. The organic loading will vary with the diurnal and seasonal fluctuations in the
BOD5 concentration in the existing POTW effluent. Design criteria for the secondary treatment
pilot plant are shown in Table E-5.
A conventional activated sludge system (Figure E-5) for a POTW includes the following
related components:
• Single or multiple reactor basins (i.e., aeration tanks) in which microorgan-
isms consume the organic wastes. These basins are designed to allow for
complete mixing of their contents, which are defined as mixed liquor
suspended solids (MLSS). Each basin must provide typical hydraulic
retention times of 2-24 hours.
• Pressurized or atmospheric oxygen-containing gases that are dispersed into
the reactor basin.
E-36
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TABLE E-5. SECONDARY TREATMENT PILOT PLANT DESIGN CRITERIA
Reactor Basin (Aeration Tank)
Volume
Detention time
Organic loading
Air requirement
Settling Basin (Final Clarifier)
Volume
Surface area
Overflow area
Solids loading
Weir length
Detention time
Influent Feed Pump
Capacity
Type
Return Activated Sludge Pump
Capacity
50 gal (189 L)
8h
25-60 Ib BOD/1,000 ftVday (0.4-1.0 kg/m3/day)
0.20-0.44 ftVmin (0.33-0.75 m3/h) ;
20 gal (76 L)
0.375 ft2 (0.035 m2)
400 gal/fWday (16.3 inVmVday)
14 Ib/ft2/day (68.4 kg/m2/day)
0.5 ft (0.152 m)
3h
0-290 gal/day (0-12.7 L/sec)
Peristaltic
0-130 gal/day (0-5.7 L/sec)
• Settling basin (i.e., final clarifier) to separate the MLSS from the treated
wastewater. j
• Equipment to collect the solids hi 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-6. Additional information on activated sludge systems is provided by the Water Pollution
Control Federation, or WPCF (1976, 1987) and WPCF/American Society for Civil Engineers
(1977).
SECONDARY TREATMENT PILOT PLANT START-UP
.
i
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
E-37
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Figure E-S. Components of a conventional activated sludge system.
E-38
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TABLE E-6. CONVENTIONAL ACTIVATED SLUDGE DESIGN PARAMETERS
Food-to-microorganism ratio
Mean cell residence time
Aeration detention time
; Oxygen requirements
Return activated sludge
flow rate
Mixed liquor suspended solids (MLSS)
Organic loading at
3,000 mg/L MLSS
, Respiration (oxygen uptake) rate
at 3,000 mg/L MLSS
Sludge volume index
, Waste activated sludge
0.15-0.4 Ib BOD5/lb MLSS/day
5-15 days
i
4-8 h ;
0.8-1.1 Ib (kg) 02/lb (kg)
BOD5 removed
30-100 percent influent flow
1,500-4,000 mg/L |
20-60 Ib BOD/1,000 ft3
(0.3-1.0 kg BOD/m3)
15-45 mg oxygen/L/h
I
I
90-150
0.4-0.6 Ib (kg)/lb (kg)
,BOD removed
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:
I
• Mixed liquor suspended solids (MLSS); ;
; • Mixed liquor volatile suspended solids (MLVSS); i
• Dissolved oxygen;
Sludge volume index (SVI);
Sludge density index (SDI);
Organic loading;
Return activated sludge (RAS) flow rate;
E-39
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• Waste activated sludge (WAS) flow rate;
• Mean cell residence time (MCRT)/solids retention time (SRT);
• Food-to-microorganism (F/M) ratio;
• Temperature;
• Hydrogen ion concentration (pH); and
• Respiration rate (RR).
In addition to monitoring these process control parameters, microscopic examination of the MLSS
should be performed.
An initial food-to-microorganism (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 weeks. If there is no local source
of MLSS, the pilot plant may be started using the POTW's effluent. An additional 4-6 weeks
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 BOD5 and suspended solids should be conducted daily during and after the
acclimation period. Sampling for toxic pollutants should not be started until 2 weeks after the
pilot plant is receiving 100 percent POTW effluent.
E-40
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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-7. 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 the technical skills of the 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.
TABLE E-7. PILOT PLANT MONITORING SCHEDULE
Sampling Point
Primary Effluent
1
MLSS
i
WAS/RAS
Secondary Clarifier
Final Effluent
Parameters"
Temperature
pH
SS
BOD5
Overflow rate
CBOD5
Temperature
PH
Dissolved oxygen
Respiration rate
Sludge volume index
SS
VSS
Microscopic examination
SS
Sludge blanket depth
Temperature
pH
Settleable solids
SS
BOD5
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
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
•SS = Suspended solids; BOD5 = 5-day biochemical oxygen demand; CBOD5 = 5-day carbonaceous biochemicd oxygen demand; VSS •.
volatile suspended solids.
E-41
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Mixed Liquor Suspended Solids (MLSS)
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 BOD5
concentration, should be adjusted based on the daily average.
Mixed Liquor 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 MLSS.
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 maintained. Samples should be collected
about 2 ft below the surface of the reactor basin, near the effluent weir. The plant operator
should adjust the ah* 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.
Sludge Volume Index (SVI)
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 minutes in a Mallory settleometer. At
the end of 30 minutes, the volume of the settled sludge is measured. The SVI (mL/g) is
calculated as follows:
_ sludge volume after settling (mL/L) x 1,000
MLSS (mg/L)
The lower the SVI, the more dense the sludge. An SVI of 150 or less is usually
considered good.
E-42
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Sludge Density Index (SDD
I
The SDI test is also used to indicate the settling characteristics of the sludge, and it is
arithmetically related to the SVI:
SDI =
100
SVI
The SDI (g/rnL) of a "good settling sludge" is about 1.0. A value of less than 1.0
indicates light sludge that settles slowly, and a value greater than 1.5 indicates dense sludge that
settles^ rapidly.
',
Organic Loading
From routine laboratory BOD5 analysis, the plant operator can determine organic loading
in the, reactor basin.
Organic loading (ib SOD/1,000 ft3/day) =
POJW effluent BOD (mg/L] x POTW ' *ffl«**Jlo» (MGD) 2L():p624
reactor basin volume (MG)
Return Activated Sludge (RAS) Flow Rate :
j
To properly operate the activated sludge process, MLSS that settle 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 charac-
teristics will require different RAS flow rates.
I
; 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. TMs 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 usually small enough to ensure that no
significant problems arise.
E-43
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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:
Volume of Settled Sludge (mL/L) x
RAS Flow Rate (MOD) =
\POTW Effluent Flow (MOD)]
1,000 mL/L
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 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. The 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 hi the treatment system, the excess
sludge must be wasted.
The best tune to measure RAS flow is during the period of maximum daily flow because
at that time 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.
E-44
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Waste Activated Sludge (WAS) Flow Rate
I
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 residence time (MCRT), based on the MLSS in the entire secondary system,
and RAS suspended solids concentration:
WAS flow rate (MOD) = MLSS (mg/L) x
[aeration tank volume (MG) +
clarifier volume (MG)}
[desired MCRT (days)} x
[RAS suspended solids (mg/L)]
Mean Cell Residence Time (MCRD/Solids Retention Time CSRD
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:
MCRT = SUSJ)enaed solids in total secondary system (Ib) _
Solids wasted (Ib/day) + effluent solids (Ib/day)
[MLSS (mg/L) x [aeration tank volume (MG) + secondary clarifier volume (MG)}
[WAS suspended solids (mg/L) x WAS flow (MGD)]~
[Effluent suspended solids (mg/L) x effluent flow (MGDj\
The 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-to-Microorganism (F/M) Ratio
i 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
MLVSS (mgIL)
To control the F/M ratio, the operator must adjust the MLSS by wasting more or less sludge
E-45
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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.
Hydrogen Ion Concentration (pH)
The activity and health of microorganisms are affected by pH. Sudden changes or
abnormal pH values may indicate an adverse industrial discharge. A pH drop also results 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 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.
The respiration rate, or oxygen uptake rate, is monitored with a dissolved oxygen meter
over a time interval (t) (e.g., 6-10 minutes). The respiration rate is a measure of the decrease in
dissolved oxygen (DO) concentration:
RR (mg oxygen/h/g MLSS) =
***j ^
x [60.000]
ri r~w tin f IWT nx'VT
[MLSS (mg/L)] x [t (mm)]
Microscopic Examination
Microscopic examination of the MLSS can be Used to evaluate the effectiveness of the
activated sludge process. The most important microorganisms 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
E-46
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that settles poorly (i.e., the sludge floe is usually light and fluffy because it has a low density).
Many other organisms (e.g., nematodes, waterborne insect larvae) may be found in the sludge,
but these organisms are not significant to the activated sludge process.
,E-47
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TOXIC POLLUTANT MONITORING PROGRAM, TESTING PROCEDURES,
AND QUALITY ASSURANCE/QUALITY CONTROL
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 Wastewater
Discharges to Marine Waters (U.S. EPA 1982a); and
Handbook for Sampling and Sample Preservation of Water and
Wastewater (U.S. EPA 1982c);
• Chemical Analytical Methods:
- Methods for Chemical Analysis of Water and Wastes (U.S. EPA 1979b,
revised 1983);
Guidelines Establishing Test Procedures for the Analysis of Pollutants
(40 CFR Part 136);
- Standard Methods for the Examination of Water and Wastewater, 16th
ed. (American Public Health Association et al. 1985);
- Analytical Methods for EPA Priority Pollutants and 301(h) Pesticides in
Estuarine and Marine Sediments (U.S. EPA 1986d); and
- Analytical Methods for EPA Priority Pollutants and 301(h) Pesticides in
Tissues from Estuarine and Marine Organisms (U.S. EPA 1986e).
E-48
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• Quality Assurance/Quality Control (QA/QC):
- f -
Handbook for Analytical Quality Control in Water and Wastewater
Laboratories (U.S. EPA 1979c) and
Quality Assurance/Quality Control (QA/QC) for 301(h) Monitoring
Programs: Guidance on Field and Laboratory Methods (U.S. EPA
1987d). :
Information from these documents is summarized below.
SAMPLING FREQUENCY i
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.
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), then the sampling plan
could be designed to collect samples during the peak period.
If a fixed sampling interval that is equal to or a multiple of the period is chosen, every
sample would be taken at the same inflow condition and the estimate of the mean difference in
toxic pollutant concentrations between samples would not take into account 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 account 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/week (over
E-49
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24 hours) on different days of the week over a 1-year 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 on the toxic pollutant
to be analyzed, three types of samples may be collected:
• 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
over time 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.)
* How-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-8,
E-9, and E-10. Grab samples for volatile organic compounds, total recoverable phenolic
compounds, and cyanide should be collected manually at least four tunes during the discharging
period of the POTW during a 24-hour period (e.g., at least every 6 hours within a 24-hour 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-ll. Sample
analyses will generally be completed by the analytical laboratory within 4-6 weeks; data analyses
will generally require an additional week. Interpretation of all data collected at the pilot plant
during 1 year will require about 2 weeks.
E-50
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TABLE E-8. 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, as CaCO. mg/L Sectrometric
end point or phenolphthalein end point
2. Alkalinity, as CaCO, mg/L
Etectrometric or cotorimetric titration
to pH 4.S, manual, or.
Automated „
3. Aluminum— Total,' mg/L Digestion*
\ followed by:
AA direct aspiration-
AA furnace
Inductively coupted plasma (ICP)
Direct current plasma (DCP) or
Cotoometnc (Eriochrome cyanme R)...
4. Ammonia (as N). mg/L: Manual distil-
lation (at pH 9.5) • followed by:
Nnssktrization..,,, „,„..,,,.,,..,, ,
Electrode _
Automated pnenat* or...
: Automated electrode
5. Antimony— Total *. mg/L Digestion*
followed by.
AA direct aspiration
AA furnace, or
i Inductively coupled plasma
',6. Arsenic— Total *, mg/L Digestion*
followed by
AA gaseous hydride
AA furnace
Inductively couptad plasma, or
i Colorimetric (SDOC)
7. Barium— Total,* mg/L Digestion * fot-
; lowed by:
AA direct aspiration
AA furnace
ICP. or
! DCP
fl. BeryiliurfH-Total,* mg/L Digestion*
followed by:
AA direct aspiration „
AA furnace „.._.
ICP
DCP, or
CokXBnetric (alurrtnon) _
9. Biochamical oxygen demand (BODS).
: mg/L
Dissotvad Oxygen Depletion ..
10. Boron— Total. mg/L
Colorimetric (curcumin) _..
ICP, or_ ..._......_
DCP
'11. Bromide, mg/L Trtrimetric
:12. Cadmium— Total,* mg/L Digestion*
followed by:
AA direct aspiration
AA furnace
ICP
DCP...
Voltametry,'0 or
i Colorimetric (DHhizone) _
EPA 1979
305.1
310.1
310.2
202.1 _....
202.2...
350.2.
350JJ_
350.2
350.3 „
350.1
204.1....
204.2
206.5
206.3
206.2... .
206.4
208.1
208.2
_
210.1
210.2. .
405.1
21 2J
320.1
213 1
213.2
Re
Standard
ITrOfhOdS
16th Ed.
402(4.a)...
403
303C
304
306B
41 7A
41 7B
41 7D
417 E or F
41 7G
303A.....
304
303E
304
3078
303C —
304
303C
304
3098
507
404A
303 A or B
304
3108
iterance (method
ASTM
1067-82(E)
01067-82(8)
'
D149ft_7QfAl
D1 426-79(0)
D1426-79(C)
02972-84(8)
D2972-84(A)
M ...I..I...UIII.
D3645-64(A)
....
* ""
01246-62(0) —
03557-64 (A
or 8).
D3557-84(Q
No. or pagii)
USGS. '
1-1030-8^1
t^QSi j>it
1-4523-84
i
1-3062-84
1-3060-84
l-3084-8!i
••W....M...M. M«*M*.K».
l-3095-«!i
..».H.»».**.H
1-1578-70*
I^l119^l
1-3133-flS.
Other
33.014*.
qo n^7 * '
33.057.*
onn 7 «
33.019 «, p. 17.'
p. S44.»
p. 37.8
E-51
-------
TABLE E-8. (Continued)
Reference (method No. or paga)
Parameter, unrtt, and mathod
EPA 1979
13. Calcium — Total.1 mg/L; Digestran-1
followed by.
AA direct aspiration
ICP _
DCP, or
Trtrimemc (EDTA)
14. Carbonaceous biochemical oxygen
demand (CBOD,), mg/L": Dissolved
Oxygen Depletion with nitrification in-
hibrtor.
15. Chemical oxygen demand (COD),
mg/U
Titrimetnc, or
Spectrophotornetnc. manual or auto-
mated.
16. Chloride. mg/L:
Titnmetnc (silver nitrate)
215.1
215.Z
410.1
410.2. or
410.3
410.4
or (Mercuric nitrate), or ; 325.3
Colonmetnc. manual or !
Automated (Femcyanide) i 325.1. or
325.2
17. Chlorine — Total residual, mg/L:
Titrimetnc:
Amperometnc direct
Starch end point direct
Back titration either end
point l«, or.
DPD-FAS
Spectrophotometric. DPD
Or Electrode
18. Chromium VI dissolved. mg/L: 0.4S
rracron filtration followad by:
AA chelaton-extrmction, or.
Cotonnwtnc (Dipnanytcarbaade)
19. Chromium— Total.3 mg/L; Dig«*t>on *
foHowedby.
AA direct aspiration
AA chelabon-extnction
AA furnace
ICP
DCP. or
Colonmetnc (DiphenytcartoazxJe)
20. Cobalt— Total,3 mg/L; Digestkxi »
followad by:
AA direct aspiration
AA furnace „ „
330.1
330.3
330.2
330.4
330.5
218.4
218.1
218.3
218.2
219.1
219.2
ICP, or _
DCP . |
21. Color platinum cobalt units or domi-
nant wavelength, hue, lummanca
putty:
Cotoomethc (ADMI). or
(Platinum cobalt), or
Spactrophotomatric
22. Copper— Total.* mg/L; Digestion'
followed by:
AA direct aspiration
AA furnace
ICP .„
DCP, or
Cotoometrtc (Naocuprotna), or (Bi-
ctncnonmata).
110.1
110.2......
110.3
220.1
220.2
Standard
methods
16th Ed.
303A ,
31 1C
507(5.e.6) ....
508A
407A
407B :
407D
408C
408A
408B
4080
408E
303B-
303A
303B
304
3 128
303 A or B...
304
2040
204A
204B
303 A or B...
304
313B
ASTM
D51 1-84(8)
D511^34(A)
01252-83
0512-81(8)
D512-8KA)
D512-81(C)
D1253-76(A)
01253-76(8)
Part 18.3
01687-84(0)
D1687-84(A)
03558-84 (A
or B).
01688-84(0
orE).
D1688-84(A)
USGS'
1-3152-85
I-3560-84CT
I-3562-84.
1-3561-84
1-1183-84
1-1184-84
1-2187-84
.
1-1232-84
1-19*WJ14
1-3236-85
I-3239-8S or
l-3240-65b.
Ul9mV-AA
1-3270-85 or
1-3271-85.
Other
200.7.4
Note 33.
33.034 », p. 1 7.«
Notes 12 or 13.
33.067.'
Note 15.
3078. '•
33.089.'
200.7.4
Note 33.
p. 37."
200.7.«
Note 33.
Note 17.
33.089.1 p. 37.«
200.7.4
Note 33.
Note 18.
E-52
-------
TABLE E-8. (Continued)
Parameter, units, and method
23. Cyanide— Total. mg.L: Manual distil-
lation with MgCl, followed by
Spectrophotometrie. manual or
Automated.'*
24. Cyanide amendable to chlorinaton,
mg/L: Manual distillation with MgCh
. followed by tjtnmatrtc or spectrophoto-
metric:
25. Fluoride— Total. mg/L: Manual distil-
lation* followed by:
Electrode, manual or
Automated
Cotonmetnc (SPADNS)
Or Automated complexone
26. Gold— Total,8 mg/L; Digestion' fol-
lowed by:
AA direct aspiration
AA furnace, or
OCP
27. Hardness— Total, as CaCO, mg/L:
Automated colorimetnc
Titnmetnc (EDTA), or Ca plus Mg as
: their carbonates, by inductively
coupled plasma or AA direct aspi-
ration. (Sea Parameters 13 and
33.).
28. Hydrogen ion (pH), pH units:
1 Electromotnc. measurement or
Automated electrode
29. Indium— Total', mg/L; Digestion* fa-
: lowed by:
AA direct aspiration, or
AA Jumace ._
30. Iron— Total,3 mg/L; Digeston' fol-
! lowed by:
AA direct aspiration _
'. AA furnace _
ICP
DCP, or
Cotorimetnc (Phenanthroline)
31. Kjeldahl nitrogen— Total, (as N), mg/
L: Digestion and distillation followed
;by:
Tttration
N«SSi3ftZCt»J1.
Electrode
Automated pnenate
Semi-automated block digastor. or
Potenttomeiric.
32. Lead— Total.' mg/L; Digestion » foi-
' lowed by:
AA direct aspiration
AA furnace
ICP
DCP
Voltametry,10 or. ,.
Colorimetric (Drthizone)
33. Magnesium— Total,' mg/L; Diges-
tion ' followed by:
AA direct aspiration
ICP
QCP nr
Gravimetric
EPA 1979
335.2
335.3
335.1
340.2
340.1
340.3
231.2
231.2
130.1
130.2
150.1
235.1
235.2
236.1...
236.2.
351.3
351.3
351.3
351.3
351.1
351.2.
239.1
239.2
242.1
j
Reference (method No. or pagti)
Standard
methods
16th Ed.
ASTM ' USGS »
412B
412C
41 2D
412F
413A
413B
413C
413E
303A....
304 ...
314B
423
303A
304
303 A or B...
304
3158...!!!!!!."!!
420 A or 8...
4170
4178
417 E or F...
303 A or B...
304
3168..
303A
318B i
D2036-82(A)
D2036-82(A)
02036-82(8)
,
i I-3300-84
D1 179-80(8) !...
I D1179-80(A)
D1 126-80
D1 293-84 (A
or 8).
01068-84 (C
orO).
D1068-64(A)!!!!!!
D3590-84(A)
D359O-A4fAl
D3590-84(A)
D3590-84(A)
D3590-84(A)...
03559-84 (A
orB).
D3559-85(C)
0511-84(8)
D511-77(A)
i
1-1338-84
1-1586-84:..
1-3381-85 „..
*•»»•**».....»..,!„.,»..,„
I-4S51-78 •'
1-3399-85 :'.
1-3447-85 .!
;
Other
i
p. 22.«
Note 33.
33.082.'
33.006.'
Note 20.
33.089.'
200.7.*
Note 33.
Note 21.
33.051.'
33.089.*
200.7.«
Note 33.
33.089.'
200.7.*
Note 33.
E-53
-------
TABLE E-8. (Continued)
Paramour, uncts, and memod
34. Manganese— Total,1 mg/L Diges-
600 ' followed by:
AA direct aspnitoon
AA furnace .
icp
DCP of
Cotorimetnc (Persullate) of
(Pfloortite) ,
35. Mercury— Total '. mg/L
Cold vapof, manual or „
Automated
36. Morybdenum— Total,' mg/L Diges-
tion * followed by:
AA direct aspiration
AA furnace .. ..
ICP or
DCP
37. Nickel— Total,1 mg/U Digestion » fol-
lowed by.
AA direct aspiration ,..,.,...,........,.....
AA furnace
ICP : „
DCP Of
Cdofirnetnc (Heptoxmne)
38. Nrtrate (as N), mg/L: Cotorimetric
(Brucme sulfate). or Nitrate-nitrite N
mtnus Nitrite N (See parameters 39
and 40).
39. NHrate-nrtnte (as N). mg/L Cadmium
reduction. Manual or
Automated, or «...
40. Nitrite (as N), mg/L: Spectrophoto-.
metric:
Manual or ... .« «
Automated (Oiazotization)
41. Oil and grease— Total recoverable,
mg/L Gravimetric (extraction).
42. Organic carbon— Total (TOC), mg/L
Combustion or oxidation.
43. Organic nitrogen (as N) mg/L Total
KjettaM N (Parameter 31) minus am-
monia N (Parameter 4.).
44. Orthophosphtte (as P), mg/L Ascor-
bic acid method:
Automated or «.
Manual single re*9ent « .......
or Manuel two reagent .«
45. Osmium— Total *, mg/L Digestion*
followed by:
AA direct aspiration, or.
AA furnace*.. . ......... . .. .. .....
46. Oxygen dissolved. mg/L Wmkler
(Aade: modification), or
Electrode
47. Palladium— Total,3 mg/L Digestion '
followed by.
AA direct aspiration ..
AA furnace _
DCP
48. Phenols. mg/L
Manual distillation "
Followed by:
Colorimetrie (4AAP) manual, or..
Automated '•
Reference (method No. or page)
EPA 1979
2431
243.2
245.1
245.2
246.1
248 2
249.1
249.2
352.1
353 3 .
353.;!....
353.1 „
354.1
413.1 „
415.1
365.1
3o6iZ «~..~.
365.3_.
252.1
252-2_
360.2.
330.1
253 1
253 ,2.
420.1
420.1
420.2
Standard
methods
16th Ed.
304 A or B...
304
31 98
303F
303C
304
303 A or B...
304
321B
41 8C
41 8F
419 —
503A
505
424G
424F
303C
304
4218
421 F
ASTM USGS '
D8S8-84 (B or
C).
D858-84(A)
D3223-80
D1886-84(C
orD).
0992-71 „._
03807-85(8)......
D3887-85(A)
01254-87
02579.85 (A or
8).
D515-82(A)
0888-81(0)
. 01783-80 (A
CxrB).
-3454-85
1-3462-84
-3490-85
1-3499-85
1-4545-84
1-4540-64
1-4601-84
Other
33.089.*
200.7.«
Note 33.
33.126.«
Note 22.
33.095.«
200.7.4
Note 33.
200.7.«
Note 33.
33.063 «, 419O >*,
p. 28.*
Note 24.
33.044 *, p. 4.*"
33.1 16. »
33.111.'
1-1575-78 T _. 33.028. *
1-1576-78 * „
. p. S27.*
p. S28.*
. Note 33.
. Note 26.
. Note 26.
E-54
-------
TABLE E-8. (Continued)
Parameter, units, and method
Reforms* (method No. or page)
EPA 1979
Standard
mo mods
16th Ed.
ASTM
49. Phosphorus (elemental) mg/L Gas- |
liquid chromatography. I
50. Phosphorus— Total. mg/L Persulfata i 365.2
digestion followed by
Manual or
Automated ascorbic acid reduction,
or.
Semi-automated block digester
51. Platinum—Total.1 mg/L; Digestion1
followed by:
AA direct aspiration
365.2 or
365.3.
365.1
365.4
AA furnace j 255.2.
255.1
DCP..
52. Potassium—total ". mg/L Digestion I
followed by:
AA direct aspiration
Inductively coupled plasma..
I
258.1
424CXIII).
424F
424G
303A
304
303A
"I"
Rame photometric, or i 322B
160.3..
209A..
160.1 i 209B
D515-82(A).....
D1428-a2(A)..
Colorimetnc (Cobaltinrtrato).
53. Residue—Total. mg/L: Gravimetric,
103-105'C.
54. Residue—filterable, mg/L Gravime-
tric. 180'C.
55. Residua—oontilterabte. (TSS), mg/L I 160.2 209C j
Gravimetnc, 103-105'C post washing i |
of residue.
56. Residue—settleabte, mg/L Volumet- I 160.5 209E
nc, (Imhoff cone) or gravimetric. ; i
57. Residue—Volatile. mg/L Gravime- i 160.4 209D
trie. 550'C. !
58. Rhodium—Total », mg/L Digestion ' i
followed by:. I
AA direct aspiration, or ! 265.1
AA furnace : 265.2
59. Ruthenium—Total'. mg/L: Diges- i
tion » followed by: i
AA direct aspiration, or '. 267.1
AA furnace j 267.2
60. Selenium—Total *, mg/L Digestion * |
followed by: i
AA furnace i 270.2
Inductively coupled plasma, or i
303A..
304....
303A
304
304.
..I..
AA gaseous hydride , 270.3 j 303E
61. Silica—Dissolved. mg/L 0.45 micron i
filtration followed by: ;
Cokximetrks, Manual or _ j 370.1 425C
Automated (Motybdcsjiicata). or
Inductively coupled plasma
62. .Silver—Total,** mg/U Digestion3
followed by:
AA direct aspiration j 272.1 303 A or 8.,
AA furnace. j 272.2 304,
Cotorimetric (Dtthizone)
ICP, or
DCP
63. Sodium—Total,1 mg/L Digestion
followed by:
AA direct aspiration 273.1 303A
ICP
120.1 ;..
32SB
205
DCP. or
Flame photometric
64. Specific conductance, microtnhos/
cm at 25*C: Wneatstone bridge
65. Sulfate (as SO*), mg/L
Automated cotorimetric (banum i 375.1
chlormnriate). i i
Gravimetric, or j 375.3 ! 426 A or B..
Turbidimetric '. 375.4
D3859-84(A)..
D859-80(B).
D1428-82(A)..
D1125-82(A)..
D516-fl2(A)..
D516-82(B)..
UJiGS1
I
Other
Note 27.
33.111.«
I-4600-84 ; 33.116.«
Note 33.
I-3630-84.
I 33.103.'
j 200.7."
i 317B.l«
-I
I-375CI-84.
I-175CI-84.
l-376fi-64.
1 !
1-37531-64.
l-3667'-84.
1-1700-84.
I-270CI-84,
l-372(>-85.
l-373!i-85.
1-1780-84.
200.7*
200.7.4
33.089.1 p. 37.'
319B."
200.7.4
Note 33.
33.107.*
200.7.«
Note 33.
33.002.*
i 33.124.*
, 426C.*»
E-55
-------
TABLE E-8. (Continued)
(msthod No. or page)
Parameter, units, and method
Standard
EPA 1979 I methods
16th Ed.
ASTM
USGS>
Other
o6. Sulfide (aa S). mg/U '
Titrimetnc (iodine) or i 376.1 '. 427D
I-3840-64 228A."
67 SuHHe (as SO>), mg/U Titrimetnc
(iodins-ttdate). j
68 Surfactants, mg/U Colonmetnc
(mathylene blue). \
69. Temperature, 'C.: Thermometnc
70. Thallium— Total s, mg/U Digestion a
followed by:
AA cjiroct aspiration .....,,. .
Inductively coupled plasma .
71. Tin— Total1. mg/U Digestion5 fol-
lowed by:
AA direct aspiration, or
72. Titanium— Total,' mg/U Digestion'
followed by:
73. Turbidity. NTU: NephetomeWc..
74. Vanadum— Total.* mg/U Digestion *
followed by:
fj^ olrect aspiration «••
AA furnace -.
OCP or
Cotorimsttic (GiUta acid) ,.„.„„„„
75. Zinc— TotaL* mg/U Digeation* fol-
lowed by:
AA dnct •ipifa.tfQf1 .___.___...............
AA furnace ..„........_
OCP or .................
Cotorimetric (Oithtzone) or .
377 1
425.1
i
170.1
279.1 |
2792
282.1
282.2
283 1
283.2
180.1
286.1 ....-__..
2864! -
289.1 ...____
289.2. ..
428A
512B
212
303A
304
303A
304
303C
304
214A
303C...._~.
304
327B
303 A or B...
304
3OTC
D1339-84(C)
D2330-82CA)
01839-81 _..
D3373-84(A).....
01691-84 (C
orO).
'
I
I-3850-78 i
1-3860-84
1-3900-85
Note 31.
200.7.4
Note 33.
200.7.4
Note 33.
33.089.* p. 37.«
200.7.4
Note 33.
Note 32.
> "Mettiods for Analysis of Inorganic Substance* h Water and Buvtal !3
-------
TABLE E-8. (Continued)
< Ammoria. Automated Electrode Method, Industrie; Method Numbs? 379-75 WE. dated Febnjary 19. 1976. Technieon
AutoAnalyzer II. Techwcon Industrial Systems. Tarrytown. NY. 10591.
1 The approved method is mat cited in "Methods for Determination of Inorganic Substances in Water and Fluvial
Sediment*". USGS TWRI, Book 5. Chapter A1 (1979).
• American National Standard on Photographic Processing Effluents. Apr. 2, 1975. Available from ANSI, 1430 Broadway.
New York. NY 10018.
9 "Selected Analytical Methods Approved and Crted by the United States Environmental Protection Agency," Supplement to
the Fifteenth Ecfition of Standard Methods for the Examination of Water and Wastowattr (1981).
10 The use of normal and differential pulse voltage ramps to increase sensitivity and resolution is ncceptaWe.
"Carbonaceous biochemical oxygen demand (CSOOi) must not be confused with the traditional BOD, test which measures
'total BOO." The addition of the nitrification inhibitor is not a procedural option, but must bo included to report the CBOD,
parameter. A discharger whose permit require* reporting the traditional BOD, may not uso a nitrification inhibitor in the
procedure for reporting the results. Only when a discharger's permit spocrtically states C8OO, is requred, can the permittee
report data using the nitrification inhibitor.
"QIC Cherracal Oxygen Demand Method. Oceanography International Corporation. 512 Wetit Loop. P.O. Box 2980. College
Station. TX 77840.
"Chemical Oxygen Demand, Method 8000. Hach Handbook of Water Analysis, 1979, Hach chomical Company, P.O. Box
389. Lovetand, CO 80537.
14 The back trtration method will be used to resolve controversy.
11 Orion Research Instruction Manual. Residual Chlorine Electrode Model 97-70, 1977. Orion Research Incorporated. 840
Memorial Drive. Cambridge, MA 02138.
'• The approved method is that cited in Standard Methods for the Examination of Water and Wasiawator, 14th Edition,
1976.
11 National Council of the Paper Industry for Air and Stream Improvement (Inc.) Technical Bulletin 253, December 1971.
'•Copper, Biocatchoinate Method. Method 8506, Hach Handbook of Water Analysis, 1979. Hach Chemical Company, P.O.
Box 389. Lovetand, CO 80537.
'• After the manual ontiHation is comptetad. the autoanaiyzer manrfokts in EPA Methods 335.3 (cyarade) or 420.2 (phenols)
are simplified by connecting the re-sample line directly to the sampler. When using the manifold setup shown «i Method 335.3,
the buffer 6.2 should be replaced with the buffer 7.6 found n Method 335.2.
"> Hydrogen Ion
-------
TABLE E-9. 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;
I
1 Acenapnthene
2. AceneplHnyhioe
3. Acrolen .. ..
5. Anthracene „_
6 Benzene
7. Benzidine „
9 BerwXatovrert*
10. B*nzoDichlofoetlmie
49 1 UlIpJllaHlMllBM
43 trina-UJXctilaraetfiene
i44 " t HL I-Jj-ujuih^wJ
45 1^-OJcNoroptopane ™.
46. ct»-1 343lcMofOpfopBf>fl
47. trana-1 ,3-Oichlof opr open* .. ._..._...„
JO 1 4JYjTyMtiu4r4uonJ
50 DuiwUiyl ptrthaiat*
51. W-n-bmyl pnthalate ,
52. OHHKtyl phtttalate. .....,.,..,.,.„„,
53. 2.4-DWtrophww*
54. 2.4-Oinitrotoluen*.
55. 2,6-OHtrolokMn*
58. EpicMorohydrin.
EPA IV
SC
610
610
603
603
610
602
610
610
610
610
610
606
611
611
608
601
601
611
601
Qf\A
601 602
601
601
601
601
612
604
A11
A1O
A1A
RO1 AO9 A19
601 602, 612
601, 602. 612
fini
601
601
601
fiO1
604
601
Mil
601
AIM
AfU.
AM
606
608
604
609
609
lathed Number »'
GC/MS
COC 1A4C
4 Q24 1 Q24
•624, 1624
625 1625
624 1624
'825 1625
cog 1R9S
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
624 1624
624 1624
624, 1624
624. 1624
624, 1624
625, 1625
625 1625
09C 1AQK
625 1625
A94 1A9A
R94 A9K 1A9t
694 898. 1O2S
625, 1624. 1625
* IGco
624, 1624
A9ot 1A9.1
A94 1A9A
ao« 1A9IC
624, 1624
624 1624
A94 1A94
625, 1625
625 1625
625, 1625
625, 1625
625. 1625
HPLC
610
""""""""""
610
610
610
" ""'"jj-
•»••»*•••••»•»••
4...H..«.<...H».
_-_
OAK
• •«••!•.. ..IKOIIH
•-"""•""""""
'**** ***
(* »• »H »««>.•»
Other
Not* 3 p 130*
Not* 6, p.
S102.
Not* 3 p 130*
Uf*m O M 1«V
Not* 3. p. 130:
i
Not* 3 p 130*
Not* 6, p.
E-58
-------
TABLE E-9. (Continued)
EPA Method Number
.
57. ^Ethytbenzene „
58. : Fluoranthene
59. Fluoreoe _
60. 'Hexacnkxobenzane
61 , '• Hexachlorobuttdiene
62. Hexachlorocyclopentadiene _
63. Hexacnloroethana
64. :ldeno<1,2.3-cd)pyrens
65. ilsopoorone
66. 'Methylane chloride
67. 2-MettiyM,6-
74. -N-Nfroaodiphenylairine _ „_
75. ' 2,2'-Oxybis<1-ehloropropane)
76.'PC8-1016
77. PC8-1 221
78. ! PC8-1 232
79. ; PCB-1 242
80. : PCB-1248.
81 . ! PCB-1 254
82.IPCB-1260
83. Pentachlorophenol :.'.
84. ! Phenantnrene
85. ' Phenol
86. i Pyrane... „
87., 2.3,7,8-Tetrachlorodibanzo-p-dioxin
88.! 1.1.2.2-Tetrachlefoathane .„
89. TotrachlorostrMne ,,,,,,,,,,
90. ' Toluene _.
91.1 ,2.4-Trichlorobenzene „
92. 1 . 1 , 1 -Tricnloroethane
93.: 1,1,2-Trichlofoethane
94. Trichloroethena
95.' TricMoroftuoromethana...
97 J Viny* chloride
GC
6O2
612
619
619
612
R1O
609
601
604
61O
fif!4
604
RO7
fiffl
607
611
608
608
608
608
608
608
608
604
610
CAA
610
601
601
any
612
601
601
ent
601
604
601
GC/MS
695 1A9te
625, 1625
695 1 69*!
*695 169*
coc 1 AOK
cpc
696
coc
coe
COB
695
coc
625 1625
fSOC 1COC
ftoc 4 coe
* Alt
624 1624
694 1 (394
695 1 fi9*S
624 1 624
694
695 1695
694 1694
1 Ottwr
HPLC !
'
610
~;
•
j
~ Note 3, p. 130;
;
— I
;
— -" — r-|
I
~—r Noto 3, p. 43;
."...., Noia 3, p. 130;
1
Table 1C Notes
'All parameters are expressed in micrograms per Bar (jig/L).
i fuN text of Methods 601-613. 624, 625. 1624. and 1625. are given at Appendix A, •Test Procedures for
', Pollutants." of this Part 138. .The standardized test preeedurete be usedUdetermine ™ ^°u— •
19?8 Pentacnlorophenol and Pesticides in Water and Wastewater."
^b* •*»"*<• » screen sample* tor AcroMn and Acrytonitrte. However, when they are known to be
efened method for these two compounds is Method 603 or Method 1624.
" " " ' rnev*0 inChTOwn*m'tit^riiinLhy?mSd?!)*nt*d'*n*' N-lWre*x*um*tlr»r«mir*»' «""* '
*AW
<• 825, Screening only.
»"Satected Anatytieat Meth
i and Cited by the United States Environmental Protection
the Fifteenth EoDton of Sttndtat MMAoo* for th» BamnfUon of Wet* tnd M4MWMMT (1981).
'Each analyst must make an initial, one-time, demonstration of their ability to generate aoei
Supplement to
with Methods 601-613. 624, 625. 1624, and 1625 (See Appendix A of this
section 8.2 of each of these Methods. AddHkxwlty, Men laboratory, on an <
for, Methods 624 and 625 and 100% for methods 1624. and 1625) of att samples to monitor
in accordance with sections 8.3 and 8.4 of these Methods. When the recovery at >n
"— — analytical results for that peramsiar in the unapfcad "*"-*
date
and owot t» rapatd to
are promulgated as an "interim final action with a request tar comments."
E-59
-------
TABLE E-10. LIST OF TEST PROCEDURES APPROVED
BY U.S. EPA FOR PESTICIDES'
NOTE: This table is an exact reproduction of Table ID in 40 CFR 136.3.
Parameter pg/L)
1. Alririn , , , , , „ ,„
9 An-ttfyff,,, .'. ,„,,,,
4. Atr_tOO_. _ _ ... "~I!1~~~ !
5, A*HHW>» ,,..............,.„„ , ,
6. Aanphpj mathyl --,„-,„„„-„,„„„.„,.„
7. 8*ft*n__ ._ „ . ....
fl. »JM*V ,. , .,„ , „,,... 1U ,
9. £-8HC
10. 6-8HC „__.
11. y-RHC (Linden*) „
1?, C«ptin.... .,„„.,„
13 r-rhfiyi, ,,,,. ,„„ „,„„„„,,„ -„„..„„.
14, CartKphtnotMon
i«; cft'ordtn*
16 CMoroprophmi , , .... ,-,-,---,,-
17 !>,_-n „ ,
IB -^'-QOO
10 A 4'_nr>P ',.„„„„„-,-„„- —,-,-,-,„
90 *>'-nnr , „.,.„ .„....„.,., ,
21. O^fmrtotvO -,-,-„„,,,,,,„
9?, n»m«rtn»_S .,,,,, ,, . Mlll,., ,,, M1J
5>3t Owin^-,,-,-,,,-,,,,,,,,,,,,,,,,,,,,,,,,,,,,
24. Dfcunb*
25. Dfchtofontfitoo
9* nirMnran
P7, pIcoW-,,,,,,,,, .„,„
29. DWdrin. ,„„-,,
f9. Dioxitt*>n „„;,
30. DftuHoton
31, Dhimn ,--„-,-„„- - -
•i?. E'Kkwjf'm 1., ,
93. Eodowttwi H.. „
34. Erxtotutftn tuHtto , ,
35. Pnririn .,-,-,-,„„„„„,-„,„„„„„„„„„„ , ,.
H8 E: ndrtn ftlcMiydff
37. Ethton.
39. Fwwroo „
39. Ftnuroo-TCA
40. H«pt*^iior. „„„,„
hMfcod
GC
GC/MS
GC
TIC
GC _
GC
GC
TLC
GC
GC/MS
GC
GC/MS
GC
GC/MS
GC
GC/MS
GC .
IXC
GC _______
SC
G&MS
TLC
«C-M-
GC
GC44S
GC
GC/MS
GC _.
GC/MS
GC---,,,,, ,
GC
GC
GC
eft
GC
ac--,,,...M.
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
EPA*-»
608
625
608
•625
608
625
608
•625
608
625
608
625
608
625
608
625
608
625
608
625
_.
60S
•625
608
•625
608
625
608
•625
608
625
608
625
Stand-
ard
M«-v
cxte
15th
Ed
S09A
509A
509A~
5O9A
508A
SO»B'
SOSA
S09A
SOSA
SOflA
S09A
~5OBA
SOSA
509A
SOBA
ASTM
D3088
03088
"'cooes"
"'cabeiT
03088
03086
03068
"oaoeaT
03066
03068
03088
03089
03086
03086
Ottwr
Note 3. p. 7; Not* 4. p. 30.
Not* 3. p. 83; Not* 6 p. S68.
Not* 3. p. 94; Not* 6 p. S16.
Not* 3, p. 83; Not* 6 p. S68.
Not* 3, p. S3; Not* « p. S88.
Not* 3, p. 25; Not* 6 p. S51.
Not* 3. p. 104; Not* 6. p. S64.
Not* 3. p. 7.
Not* 3, p. 7; Not* 4, p, 30.
Not* 3. p. 7.
Not* 3. p. 94; Not* 6, p. SCO.
Not* 4, p. 30; Not* 6. p. S73.
Not* 3. p. 7.
Not* 3. p. 104; Not* 6. p. S64.
Not* 3. p. 115; Not* 4, p. 35.
Not* 3, p. 7; Not* 4, p. 30.
Not* 3. p. 7; Not* 4. p. 30.
Not* 3. p. 7; Not* 4. p. 30.
Note 3, p. 25; Not* 6. p. SSI.
Not* 3. p. 25; Not* 6, p. SSI.
Not* 3, p. 25; Not* 4. p. 30;
Not* 6, p. SSI.
Not* 3. p. 115.
Not* 4. p. 30; Not* 6. p. S73.
Not* 3. p. 7.
Not* 3, p. 7; Not* 4, p. 30.
Not* 4. p. 30; Not* 6. p. S73.
Not* 3, p. ; Not* 6, p. SSI.
Not* 3. p. 104; Not* 6, p. S64.
Not* 3, p. 7.
Not* 3, p. 7.
Not* 3, p. 7; Note 4, p. 30.
Not* 4, p. 30; Not* 6, p. S73.
Not* 3, p. 104; Not* 6, p. S64.
Not* 3, p. 7; Not* 4, p. 30.
E-60
-------
TABLE E-10. (Continued)
Parameter pg/L)
41. Heptachtor epoxxto
i
42 ' Isodrin . . ....
43.' Unuron
44.; Malathion ....
45.; Methiocarb „
46' MothoxycnKx
47' MwtaCaitHrt*.,,,,. „„,„ „ .,..„„„„„ , , , „ ,„.,
48J Mirex
49: Monuron
50i Moouroo-TCA
51 1 Neburon
52. Parathion methyl
531 Parathion ethyl „
54 ! PCNB
55i Perthan* _ _
S7i Prometryn............. „
58i Propazin*
59i Propham.. ™
€0' Propoxur .. .
61 1 Secbumeton
62l SkJuron „ _.
63 Simazm*. . .
641, Stroban*
<55' Swep ,..,
68. 2,4.5-T
67. 2,4,5-TP (Slvex)
68 Twbuthylazjrw
69 TOXaPhflne -X -*- X J . * ..,,4*1,,.^ ,....** 1......J*
70 Trifluraiin.
Method
GC...
j
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
EPA1-'
608
625 I
'
608
625
Stand-
ard
Meth-
od*
15th
Ed
509A
509A
509A
509A
509A
509A
509A
509A
5098
5098
509A
509A
ASTM
03088
D3086
03086
03086
I
; Othar
Not* 3. p. 7; Note 4, p. 30; Not*
6. p. S73.
Not* 4. p. 30; Not* 6, p. S73.
Not* 3, p. 104; Not* 6. p. S64.
Not* 3, p. 25; Not* 4. p. 30;
Not* 6, p. 851.
Not* 3, p. 94; Not* 6. p. S60.
Not* 3. p. 7; Not* 4, p. 30.
Not* 3. p. 94; Not* 8, p. SCO.
Not* 3, |). 7.
Not* 3, p. 104; Not* 6. p. S64.
Not* 3. p. 104; Not* 6. p. S64.
Not* 3, p. 104; Not* 6. p. S64.
Not* 3. p. 25; Not* 4, p. 30.
Not* 3, f>. 25.
Not* 3, p. 7.
Not* 3. p. 83; Not* 6. p. S86.
Not* 3. p. 83; Not* 6. p. S68.
Not* 3. p. 83; Not* 6. p. S68.
Not* 3, p. 1C4; Note 8, p. S64.
Not* 3. p. 94; Not* 6. p. S60.
Not* 3, p. 83: Not* 6. p. S68.
Not* 3. p. 104; Not* 6. p. S64.
Not* 3. p. a'3; Not* 6. p. S6B.
Not* 3, [J. 7.
Not* 3, p. 104; Not* 6. p. S64.
Not* 3, p. 1 15; Not* 4, p. 35.
Not* 3, p. 11 !5.
Not* 3, p. 83; Not* 6. p. S68,
Not* 3. p. 7; Not* 4, p. 30.
Not* 3, p. 7
Tab* ID Note*
:' Period** an tsttd in this tabi* by common ram* (or the convenience of the reader. Additional pestksbe* may be found
under Table 1C. wner* «iHifM ar* titled by chemical name.
* The Ml text of method* 608 and 625 ar* given at Appendix A, 'Test Procedures for AnaJyei* of Organic Pollutants," of
this Part 136. The standardized teat procedure to be used to determine the method detection limit (VIOL) for
procedure* is given at Appendix 8. "Definition and Procedure for th* Determination of the Method Detirtori Limit", of thia Part
138.
* "Method* for Benzidin*, Chlorinated Organic Compound*. Pentachlorophanot and Peattddes in Water and Wattwater,"
U.S. Environmental Protection Agency, September. 1978. This EPA publication indud** thin-layer crranatography (TLC)
method*.
'"Methods for Analysis of Organic Subatancm in Watar," U.S. Geological Survey, Technique* of Watar-fi*eourc*e
Investigations. Book 5. Chapter A3 <1972).
;• The method may be extended to include a-BHC, 5-BHC. endosurtan I, endowrfan II, and^endrin. Howovar, whan they ere
known to exist. Method 608 is the prelerred method.
'• "Solected Analytical Method* Approved and Cited by the United State* Environmental Protection Agency." Supplement to
the Fifteenth Edition of Sttndffd Methods far the Extmimtion of W»t»r tnd WtatftmHr (19S1).
!' Each analyst must make an initial, one-time, demonstration of their ability to generate acceptaoki precision and accuracy
with Methods 608 and 625 (See Appendix A of thti Part 136) in accordance with procedure* given in section 8.2 of eacn of
these method*. Additionally, each laboratory, on an on-going bast*, mutt spike and analyze 10% of ill sample* analyzed wrth
Method 608 or 5% of an sample* analyzed wrth Method 625 to monitor and evaluate laboratory dita quality in accordance
with Section* 8 J and 8.4 of the** method*. When th* recovery of any parameter faHs outside th* wanting hrnrta, th* analytical
results for that parameter in th* unsoiked sampt* ar* suspect and cannot be reported to demonstrate regulatory compliance.
NOTE: Theee warning fenrt* ar* promulgated as an "Interim final action with a request for comment*."
E-61
-------
TABLE E-ll. RECOMMENDED SAMPLE SIZES, CONTAINERS, PRESERVATION, AND HOLDING
TIMES FOR EFFLUENT SAMPLES
Measurement
pH
Temperature
Turbidity
Total suspended solids
Settleable solids
Floating particulates
Dissolved oxygen
Probe
Winkler
Biochemical oxygen demand
Total chlorine residual
Oil and grease
Nitrogen
Aramonia-N
Total Kjeldahl-N
Nitrate+Nitrite-N
Phosphorus (total)
Priority pollutant metals
Metals, except mercury
Mercury
Minimum
Sample Size*
(mL)
25
1,000
100
1,000
1,000
5,000
300
300
1,000
200 '
1,000
400
500
100
50
100
100
Container11
P, G
P, G
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
Preservative'
None
None
Cool, 4 °C
Cool, 4 °C
Cool, 4 °C
None
None
Fix. onsite;
store in dark
Cool, 4 °C
None
Cool, 4 °C
H2S04 to PH<2
Cool, 4 °C
H2SO4topH<2
Cool, 4 °C
H2SO4 to pH<2
Cool, 4 °C
H2SO4 to pH<2
Cool, 4 °C
H2SO4 to pH<2
HN03 to pH<2
HN03 to pH<2
Maximum
Holding Time
Analyze, immediately11
Measure immediately11
48 h
7 days
48 h
Analyze immediately'1''
Analyze immediatelyd
8h
48 h
Analyze immediatelyd
28 days
28 days
28 days
28 days
28 days
6 mo
28 days
E-62
-------
TABLE E-ll. (Continued)
Measurement
Minimum
Sample Size'
(mL)
Container11
Preservative0
Maximum
Holding Time
Priority pollutant organic
compourids
Extractable compounds 4,000
(includes phthalates,
nitrosamines, organo-
chlorine pesticides,
PCBs, nitroaromatics,
isophorbne, polycyclic
aromatic hydrocarbons,
haloether, chlorinated
hydrocarbons, phenols,
and TCDD)
Purgeable compounds 40
Total and fecal coliform
bacteria : 250-500
Enterococcus bacteria 250-500
G only, Cool, 4 °C
TFE-lined cap 0.008% Na^CX
Store in dark
G only,. Cool, 4 °C
TFE-lined septum 0.008%
P, G Cool, 4°C
0.008%
P, G Cool, 4 °C
0.008%
7 days until
extraction
40 days after
extraction
7 days8
6h
6h
Source: 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.
bP = 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. When use of an automated sampler makes it impossible to preserve each aliquot, the samples should be maintained at
4 °C until compositing.
"Immediately means as soon as possible after the sample is collected, usually within 15 min (U.S. EPA 1984b).
'No recommended holding time is given by EPA for floating particulates. Analysis should therefore be made as soon as possible.
'Should be used only in the presence of chlorine residual.
*Holding time and preservation technique for purgeable compounds are based on the use of EPA Method 624 for screening all priority pollutant
volatiles organic compounds, including acrolein and acrylonitrile. If analysis of acrolein and acrylonitrile 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 EPA Method 603.
QUALITY ASSURANCE/QUALITY CONTROL
procedures should be detailed in the quality assurance project plan (U.S. EPA
1979c, l987d). The following items should be discussed in the quality assurance project plan:
P Statement and prioritization of study objectives;
Responsibilities of personnel associated with sample collection and analysis;
E-63
-------
• 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 requirements; and
• Laboratories to which samples will be shipped.
U.S. EPA (1987d) provides QA/QC guidance for the folio whig activities:
• Preparation for sampling program;
• Sample collection;
• Sample processing;
• Sample size;
• Sample containers;
• Sample preservation;
• Sample holding tunes;
• Sample shipping;
• Record keeping;
» Labeling;
• Custody procedures;
E-64
-------
• Analytical methods;
\ • Calibration and preventive maintenance;
i • Quality control checks;
• Corrective action; and
i
: • Data reporting requirements.
Field iSampling Procedures
For the field sampling effort, the following procedures are recommended:
• Establish and implement chain-of-custody protocols to track saimples from the
: point of collection to final disposition.
i
, • Establish and implement protocols to prepare sample containers.
i (.
• Prepare field "blank" samples to assess potential sample contamination by the
sampling devices.
• i
1 • Prepare "trip blanks" to assess potential contamination by volatile organic
analytes en route to the laboratory (one trip blank per sample shipment).
• Collect replicate samples to assess sample precision and the homogeneity of
samples collected.
i
• Use appropriate sample collection procedures (see Table E-11).
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
E-65
-------
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-9 to E-ll). The following
documentation is requked by the analytical laboratory for QA review of data on organic
substances (see Tables E-10 and E-l 1):
• 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); and
• Analysis of duplicate samples (rninimum of 5 percent of samples analyzed)
and use of matrix spikes to determine organic recoveries.
The following documentation is requked by the analytical laboratory for QA review of data on
inorganic substances (see Table E-8):
• Multipoint calibration;
* Analysis of reagent blanks;
• Use of matrix spikes of 0.5-5 times the sample concentration;
• Determination of method detection limits;
E-66
-------
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);
Performance of duplicate analyses for a minimum of 5 percent of the total
number of samples analyzed; and
Use of the method of standard additions for samples demonstrating
interferences. i
Data Evaluation
Data generated from the monitoring-program should be evaluated using the stepwise
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);
i
1 Matrix spike/matrix spike duplicate results;
• Surrogate recovery data;
• Instrument tuning data;
Chain-of-custody records;
Analytical request forms;
E-67
-------
2.
• Gas chromatograms;
• Mass spectra;
• 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; and
« Holding time documentation.
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 procedure (e.g., extraction or digestion) 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-68
-------
• 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-69
-------
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. The 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 before 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-12 and E-13). 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-12 and E-13 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 differ from
than those expected in a full-scale secondary treatment facility. For example, the pilot plant will
be operated at a constant flow rate and will not be subject to the diurnal and seasonal flow
fluctuations normally experienced at treatment facilities or to the slug loadings and batch
discharges that POTWs can experience in daily operation. Also, 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 conditions.
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TABLE E-12. REPORTED VALUES FOR ACTIVATED SLUDGE BIOLOGICAL
PROCESS TOLERANCE LIMITS OF ORGANIC PRIORITY POLLUTA>>fTS
Pollutant
Threshold of
Inhibitory Effect (mg/L)"
Acenaptithene
Acrolein
Acrylonitrile
Benzene1
Benzidine
Carbon tetrachloride
Chlorobenzene
1,2,4-Tribhlorobenzene
Hexachlorobenzene
1,2-Dichioroethane
1,1, 1-Trichloroethane
Hexachloroethane
1,1-Dichloroethane
1,1,2-Tri0hloroethane
1,1,2,2-Tetrachloroethane
bis(2-Ch|oroethyl)ether
2-Chloro'ethyl vinyl ether
2-Chloro^iaphthalene
2,4,6-Trif:hlorophenol
4-Chloror3-methyl phenol
Chloroform
2-Chlorojphenol
1,2-Dichlorobenzene
1,3-Dichiorobenzene
1,4-Dichlorobenzene
1,1-Dichtoroethylene
trans-1,2-Dichloroethylene
2,4-Dichlorophenol
1,2-Dichloropropane
1,3-Dichloropropylene
2,4-Dimethylphenol
2,4-Dinittotoluene
2,6-Diniti:otoluene
1,2-Diphenylhydrazine
Ethylbenzene
Fluoranthene
bis(2-Chloroisopropyl)ether
Chloromethane
Bromoform
Dichlorobromomethane
Trichlorofluoromethane
Chlorodibromomethane
Hexachlorobutadiene
Hexachlorocyclopentadiene
Isophorone
Naphthalene
Nitrobenzene
NIb at 10
Mat 62
NI at 152
125
5
Mat 10
Mat 1
Mat6
5
M at 258
Mat 10
Mat 10
Mat 10
Mat 5
M at 201
Mat 10
Mat 10
Mat 10
50
Mat 10
Mat 10
Mat 10
5
5
5
Mat 10
Mat 10
Mat 75
M at 182
Mat 10
Mat 10
5
5
5
Mat 10
Mat 5
Mb at 10
M at 180
Mat 10
Mat 10
Mat 10
Mat 10
Mat 10
Mat 10
M at 15.4
500
500
E-71
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TABLE E-12. (Continued)
Pollutant
Threshold of
Inhibitory Effect (mg/L)a
2-Nitrophenol
4-Nitrophenol
2,4-Dinitrophenol
N-Nitrosodiphenylamine
N-Nitrosodi-n-propylamine
Pentachlorophenol
Phenol
bis(2-Ethylhexyl)phthalate
Butyl benzyl phthalate
Di-n-butyl phthalate
Di-n-octyl phthalate
Diethyl phthalate
Dimethyl phthalate
Chrysene
Acenaphthylene
Anthracene
Fluorene
Phenanthrene
Pyrene
Tetrachloroethylene
Toluene
Trichloroethylene
Aroclor-1242
Aroclor-1254
Aroclor-1221
Aroclor-1232
Aroclor-1016
Mat 10
NI at 10
1
Mat 10
Mat 10
0.95
200
Mat 10
Mat 10
Mat 10
M at 16.3
Mat 10
Mat 10
Mat 5
Mat 10
500
M at 10
500
Mat 5
M at 10
M at 35
M at 10
Mat 1
Mat 1
Mat 1
Mat 10
Mat 1
Source: U.S. EPA (1986c).
•Unless otherwise indicated.
'NI = no inhibition at tested concentrations. No concentration is listed if reference lacked concentration data.
E-72
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TABLE E-13. REPORTED VALUES FOR ACTIVATED SLUDGE BIOLOGICAL
PROCESS TOLERANCE LIMITS OF INORGANIC PRIORITY POLLUTANTS
Pollutant
Threshold of
Inhibitory Effect (mg/L)
Arsenic
Cadmium
Chromium (VI)
Chromium (HI)
Copper
Cyanide
Lead
Mercury
Nickel
Silver
Zinc
0.1
1
1
10
1
0.1
0.1
0.1
1
5
0.03
Source: U.S. EPA (1986c).
E-73
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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 pollutants 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 pollutant in the effluent. If these concentrations are
more stringent than effluent limits based on state water quality standards or 304(a)(l) water
quality criteria, if applicable, or are otherwise required to ensure that all environmental protection
criteria are met, then 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 pollutant in the effluent of the section 301(h) modified discharge is
equal to, or less than, the concentration achieved using the secondary treatment pilot plant. For
toxic pollutants whose concentration hi 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
pollutants, in accordance with the guidance given earlier. These would be in the form of numeric
local limits, allocated according to one of the approaches outlined previously in this appendix.
As discussed in this section of the appendix, local limits allocations can be based on
concentration limits or on flow-corrected mass loading limits, depending on the type of toxic
pollutant (conservative vs. nonconservative) and the type and mix of industrial sources of that
toxic pollutant. 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-74
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REFERENCES
American i Public Health Association, American Water Works Association, and Water Pollution
Control Federation. 1985. Standard methods for the examination of water and wastewater. 16th
ed. Port City Press, Baltimore, MD.
U.S. EPA. 1979a. NPDES compliance sampling manual. MCD-51. U.S. Environmental
Protection Agency, Enforcement Division, Office of Water Enforcement Compliance Branch,
Washington, DC.
U.S. EPA. 1979b (revised March 1983). Methods for chemical analysis of water and wastes.
EPA 600/4-79-020. U.S. Environmental Protection Agency, Environmental Monitoring and
Support Laboratory, Cincinnati, OH.
U.S. EPA; 1979c. Handbook for analytical quality control in water and wastewater laboratories.
U.S. Environmental Protection Agency, National Environmental Research Center, Cincinnati, OH.
U.S. EPA. 1982a. Design of 301(h) monitoring programs for municipal wastewater discharges
to marine iwaters. EPA 430/9-82-010. U.S. Environmental Protection Agency, Office of Marine
Discharge Evaluation, Washington, DC.
i
i
U.S. EPA. 1982b. Revised section 301(h) technical support document. EPA 430/9-82-011.
Prepared for U.S. Environmental Protection Agency, Office of Water, Washington, DC.
U.S. EPA. 1982c. Handbook for sampling and sample preservation of water and wastewater.
EPA 600/4-82-029. U.S. Environmental Protection Agency, Environmental Monitoring and
Support Laboratory, Cincinnati, OH.
U.S. EPA. 1982d. Fate of priority toxic pollutants in publicly owned treatment works. EPA
440/182/303. U.S. Environmental Protection Agency, Office of Water, Effluent Guideline
Division, Washington DC.
U.S. EPA. 1983a. Guidance manual for POTW pretreatment program development. U.S.
Environmental Protection Agency, Office of Water Enforcement and Permits, Washington, DC.
U.S. EPA. 1983b. Procedures manual for reviewing a POTW pretreatment program submission.
U.S. Environmental Protection Agency, Office of Water Enforcement and Permits, Washington,
DC.
U.S. EPA, 1984a. NPDES compliance inspection manual. U.S. Environmental Protection
Agency, Office of Water Enforcement and Permits, Washington, DC.
U.S. EPA: 1984b. Report on the implementation of section 301(h). EPA 430/9-84-007. U.S.
Environmental Protection Agency, Office of Water Program Operations. Washington, DC
E-75
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U.S. EPA. 1985a. Guidance manual for implementing total toxic organics (TTO) pretreatment
standards. U.S. Environmental Protection Agency, Permits Division, Washington, DC.
U.S. EPA. 1985b. Guidance manual for the use of production-based pretreatment standards and
the combined wastestreamformula. U.S; Environmental Protection Agency, Permits Division and
Industrial Technology Division, Washington, DC.
U.S. EPA. 1986a. Pretreatment compliance monitoring and enforcement guidance. U.S.
Environmental Protection Agency, Office of Water Enforcement and Permits, Washington, DC.
U.S. EPA. 1986b. Pretreatment compliance inspection and audit manual for approval authorities.
U.S. Environmental Protection Agency, Office of Water Enforcement and Permits, Washington,
DC.
U.S. EPA. 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. Environmental
Protecti'on Agency, Office of Water Regulations and Standards, Washington, DC.
U.S. EPA. 1986d. Analytical methods for EPA priority pollutants and 301(h) pesticides in
estuarine and marine sediments. EPA 50316-90-004. U.S. Environmental Protection Agency.
Office of Marine and Estuarine Protection, Marine Operations Division, Washington, DC.
U.S. EPA. 1986e. Bioaccumulation monitoring guidance: 4. Analytical methods for U.S. EPA
priority pollutants and 301 (h) pesticides in tissues from estuarine and marine organisms. EPA
50316-90-002. U.S. Environmental Protection Agency, Office of Marine and Estuarine
Protection, Marine Operations Division, Washington, DC.
U.S. EPA. 1987a. Guidance manual for preventing interference at POTWs. U.S. Environmental
Protection Agency, Office of Water Enforcement and Permits, Washington, DC.
U.S. EPA. 1987b. Guidance for reporting and evaluating POTW noncompliance with
pretreatment implementation requirements. U.S. Environmental Protection Agency, Office of
Water Enforcement and Permits, Washington, DC.
U.S. EPA. 1987c. Guidance manual on the development and implementation of local discharge
limitations under the pretreatment program. U.S. Environmental Protection Agency, Office of
Water Enforcement and Permits, Washington, DC.
U.S. EPA. 1987d. Quality assurance/quality control (QA/QC) for 301(h) monitoring programs:
guidance on field and laboratory methods. EPA 430/9-86-004. U.S. Environmental Protection
Agency, Office of Marine and Estuarine Protection, Washington, DC.
U.S. EPA. 1988. Toxicity reduction evaluation protocols for municipal wastewater treatment
plants. EPA 600/2-88-062. U.S; Environmental Protection Agency, Washington, DC.
U.S. EPA. 1989. POTW sludge sampling and analysis guidance document. U.S. Environmental
Protection Agency, Office of Water Enforcement and Permits, Washington, DC.
E-76
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U.S. EPA. 1991a. Supplemental manual on the development and implementation of local
discharge limitations under the pretreatment program: Residential and commercial toxic pollutant
loadings and POTW removal efficiency estimation. U.S. Environmental Protection Agency,
Office of Wastewater and Compliance, Washington, DC.
U.S. EpA. 1991b. Technical support document for water quality-based toxics control. EPA
505/2-90-001. U.S. Environmental Protection Agency, Office of Water, Washington, DC.
U.S. EPA. 1993a. Training manual for NPDES permit writers. U.S. Environmental Protection
Agency, Office of Water, Washington, DC.
U.S. EPA. 1993b. Water quality standards handbook. 2d ed. EPA-823/B-93-002. U.S.
Environmental Protection Agency, Office of Water, Washington, D.C.
t I
i
Water Pollution Control Federation. 1976. Manual of practice no. 11, Operation of wastewater
treatment plants. Lancaster Press, Inc., Lancaster, PA.
Water Pollution Control Federation. 1987. Manual of practice OM-9, Activated sludge. Water
Pollution Control Federation, Alexandria, VA.
Water Ppllution Control Federation/American Society of Civil Engineers. 1977. Wastewater
treatment plant design. Lancaster Press, Inc., Lancaster, PA.
E-77
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ATTACHMENT 1 TO APPENDIX E
U.S. EPA GUIDANCE MANUAL ON THE DEVELOPMENT AND
IMPLEMENTATION OF LOCAL DISCHARGE LIMITATIONS
UNDER THE PRETREATMENT PROGRAM
(DECEMBER 1987) !
CHAPTER 5 - INDUSTRIAL USERS MANAGEMENT PRACTICES
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5. INDUSTRIAL USER MANAGEMENT PRACTICES
5.i INTRODUCTION
The development and implementation of numeric local limits is not always
the only appropriate or practical method for preventing pollutant pass through
i
and interference, or for protecting POTW vorker health and safety. Control of
chemical spills and s.lug discharges to the POTW through formal chemical or
waste management plans can go a long way toward preventing problems. A local
requirement for an IU to develop and submit such a plan can be considered as a
i
type of narrative local limit and can be a useful supplement to numeric
limits.
i • i
the basic philosophy of instituting management practices is to minimize
the discharge of toxic or hazardous pollutants to the sever, or at least to
reduce the impact of toxic/hazardous pollutant discharges by avoiding short- °
term, high concentration discharges. Management practice plains generally are
developed to prevent or control the discharge of hazardous or toxic materials,
such as acids, solvents, paints, oils, fuels and explosives by means of
appropriate handling procedures, possibly in addition to pretreatment. Slug
discharges of process wastevater (including high BOD/COD wastes) can also be
effectively controlled through the use of management.practices.
In the NPDES permitting program for direct dischargers, industries can be
required under 40 CFR Part 125, Subpart K to implement best management
practices (BMPs) to minimize the discharge of toxicants to surface waters.
These*plans are meant to address:
i
I
* Toxic and hazardous chemical spills and leaks
» Plant site run-off
• Sludge and waste disposal
• Drainage from material storage areas
• Other "good housekeeping" practices.
While direct discharger BMPs address only activities which are ancillary to
manufacturing or treatment processes, IU management practices under a local
pretrieatment program can also include:
5-1
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• Solvent management plans
• Batch discharge policies
• Waste recycling
• Waste minimization.
The first step a POTW must take in implementing its program is to be
certain that the POTV has the requisite legal authority. This involves
ensuring that proper language regarding IU management practices are contained
in the sever use ordinance (at a minimum) and in IU permits. The sewer use
ordinances or regulations of most POTWs may already include provisions for
requiring Ills to develop management practice plans.
When evaluating the need for IU management plans, POTWs may follow the
following steps:
• Evaluation of the potential for toxic and hazardous chemicals onsite
to reach the sewer system
• Assessing the adequacy of any industry management plans and practices
already in place, and requiring revisions to these as necessary.
!• Evaluation of the Potential for Toxic and Hazardous Chemic-is Ons • .0
Reach the Sewer System. The primary concern on the part of the POTW when
evaluating the adequacy of IU management practices is the likelihood of slugs/
spills of chemicals reaching the sewer system. Inspectors need,to focus on:
(1) the types of and quantities of chemicals that are handled (e.g., trans-
ferred), stored, or disposed onsite; and (2) the location(s) of all chemical
handling, storage and disposal activities with respect to sever access. The
chemicals managed in areas of highest risk of being discharged to the sewers
(through spills, slug loading, or accidents) should be of the highest priority
to be addressed in management plans.
2- Assessing the Adequacy of Existing Management Plans and Practices. POTW
officials should carefully evaluate any existing industry management plans.
Receiving particular scrutiny should be:
• The practices that are proposed (and whether they are currently being
followed)
5-2
-------
• Whether the plan is reflective of current operations at: the industry
• Whether the plan vas designed to prevent discharges to the severs
• iWhether plant personnel are required to follow the plan
• The familiarity of personnel with the plan !
• Any conditions that must be met before a response/corr«ct:lve action
can be taken
I ;
• ; Whether all toxic chemicals managed in areas with access to sewers are
addressed.
If deficiencies are found in the existing plans, the IU should be required to
correct: them before submitting a revised plan to the POTW for approval.
Further details of recommended plan specifics are discussed later in this
section.
I i
, «
The following sections of this chapter outline the elements of three
types of industry management practice plans; chemical management plans, spill
contingency, and best management practices plans. POTWs should be aware that
hybrids of the plans presented may be appropriate for a particular situation
and that some overlap of management practice requirements exists. Key to each
of these plans is the continued training of staff and proper implementation.
5.2 CHEMICAL MANAGEMENT PLANS
Chemical management plans differ from the other two types of: management
plans introduced above because they target specific chemicals or groups of
chemicals that are considered to be of concern. One example of a chemical
management plan that is widespread is the solvent management plan required of
metal finishers by federal categorical standards.
POTVs may wish to pay special attention to certain groups; of chemicals
that have historically caused management problems. Examples of such chemical
groups: are:
Sitrong acids (e.g., hydrochloric acid, sulfuric acid, nitric acid, and
chromic acid)
•I
Strong bases (e.g., caustic soda, lye, ammonia, lime, etc.)
-
5-3
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Noxious/fuming chemicals .(e.g.., phosphorus pentachloride, hydrofluoric
acid, benzene, chloroform) /utuj.iuoiric
Flammable chemicals (e.g., acetone, naptha, hexane, cyclohexane)
(e
-------
data gathering effort. These data should be gathered through onsite inspec-
tions whenever possible. Once this basic information is compiled, its
accuracy should be verified with the IU and should subsequently provide the
basis for assessing the need for, and adequacy of, chemical management plans
submitted by the industry. Elements of the industry's chemical management
plan should address each of the potential release points. Whenever possible,
the industry should be provided with specific language indicating the accept-
able levels of the chemical in the sewer so that a clear yardstick is estab-
lished against which the success or failure of the management plan can be
measured. An example of this is again provided by the metal finishing
industry's solvent management plans which attempt to achieve a total toxic
organic (TTO) pollutant limit of 2.13 mg/1.
Examples of plan components that would target specific release points
are: 'prevent access through floor drains to sewers in areas of possible t
chemical spillage; the installation of sumps in floor drains providing a
capacity that exceeds the largest projected potential spill volume by a safety
margin of perhaps 10 percent; and the education of plant workers handling the
chemicals of concern in areas with access to sewers.
POTW staff could also discuss the feasibility of possible chemical
substitution, process modifications, and/or waste segregation as means of
source control. j
,
• Chemical substitution may be possible if there are other compounds
that will fulfill the same function demanded of the chemical of
concern; assuming that the substitute itself does not exhibit any
properties with the potential to cause problems for the POTV. Key
factors in the feasibility of this option will be the cost and
availability of the substitute chemical; the chemical and physical
properties of the substitute and whether these properties will have a
substantive effect on the manufacturing process or subsequent wastes
handling operations/liabilities.
• Process modifications that would reduce or eliminate the presence of
the chemicals of concern would be an attractive option if feasible.
It is likely that industry officials will have a better understanding
of the limitations to such modifications than POTV personnel, but this
should not inhibit inspectors from raising this option as a possi-
bility. Examples of process modification are the use of different,
more effective polymers during wastewater treatment, resulting in an
improved removal efficiency for the target pollutant; and changing the
5-5
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degreasing procedures utilized in cleaning product components,
possibly rrom immersion in solvent baths and subsequent rinsing with
water, to the wiping of the components manually with the solvent, and
air drying under a vacuum hood.
• waste segregation may be an effective means for improving wastevater
treatment efficiency. If the presence of more than one wastewater
component acts to limit the efficiency of a treatment process, it may
be possible to undertake some form of waste segregation (possibly by
distillation) that would separate the components sufficiently to allow
for efficient subsequent treatment.
In some instances the institution of formal procedures for the handling,
transfer, and storage of chemicals will be useful. For example, if a specific
chemical is only used in the manufacturing process in small quantities, the
dispensing of the chemical in bulk quantities could be discouraged. This
action would reduce the quantities potentially spilled during transfer and
also reduce the quantity of "left-over" chemicals that might be carelessly
discarded. In some instances the centralized storage of chemicals could
improve the logistics of chemical use supervision and provide a principle
point of focus for chemical management efforts.
The chemical management plan for each facility should be endorsed by
a responsible official at the facility and include a written commitment that
the practices described will be followed as a matter^of company policy. In
instances where industries appear reluctant to implement the procedures
delineated in the management plans, POTWs may wish to withhold formal approval
of the management plan until a trial period illustrates that the procedures
are indeed being implemented.
5.3 SPILL CONTINGENCY PLANS
Many industries with large storage tanks onsite may already have spill
contingency plans in place, sometimes as a matter of company policy. This
kind of familiarity with planning and response procedures is a definite plus
from the POTW's point of view. However, existing spill plans may address only
a portion of the potential pollutant sources of concern to the POTV and may
not be as sensitive to protection of the sewer system as needed. Also, the
quantity and types of materials spilled that would initiate a spill response
under existing contingency plans may be inconsistent with pretreatment
5-6
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concerns land needs. With this in mind, POTV inspectors should carefully
reviev any existing plans for their adequacy as opposed to accepting them at
face value. The items which should be focused upon in reviewing a spill
contingency plan are the same as those considered in the design of a new plan
and include:
• Identification of high risk chemicals
• Identification of high risk handling and storage procedure!; and plant
locations
I
• Identification and mapping of potential release points relative to
sewer access points ,
• Identification of and preparation-for possible spill containment
and/or countermeasures , I
• Identification of individuals responsible for implementation of the
spill plan, individuals with the authority to commit additional
resources to a response action, if necessary; and designation of a
predetermined chain of command for coordinating spill response
activities—depending on the type of spill
• Documentation of the entire spill contingency plan, including:
- Maps of key area
- Equipment lists, and equipment storage and, in-plant staging
locations
;- Names and functions of all plant officials with a role in spill
contingency planning and implementation
- Names and phone numbers of POTW officials who should be contacted
i in the event of a spill (the industry may choose to also include
local fire department, police, and emergency rescue information)
- A commitment to provide the POTV with a written notification or
' report within a short period (3 days) following an incident,
explaining the cause of the spill, and steps that are being taken
: to prevent recurrence ,
'.- An endorsement of the spill plan by responsible industry officials,
including a commitment to implement the plan as per the facility's
permit requirement ,
!- An indication as to the date when the plan was last updated, and a
commitment to update the plan periodically, or following a spill
incident.
5-7
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Inspectors should carefully rev.iew all the details of the plan and be
satisfied that it is adequate from, the POTW's perspective before recommending
formal approval. Additional information on spill contingency plans may be '
found in "EPA Region X Guidance Manual for the Development of Accidental Spill
Prevention Programs." U.S. EPA Region X, Seattle, VA, February 1986. An
example is also provided in Appendix K. In addition, EPA is currently
developing a guidance manual to help identify the need and methods for
developing slug control plans.
5.4 BEST MANAGEMENT PRACTICES PLANS
The concept of best management practices plans (BMPs) is veil accepted in
the NPDES program, and many of the same principles apply equally well to
indirect dischargers. In this section, the types of requirements that could
be required of an IU under the provisions of a BMP are -discussed. As in the
case of the other types of management plans, the^actual requirement imposed on
any particular industry will vary depending on site-specific needs.
Much of the focus of BMPs is on good housekeeping and proper operation
and maintenance measures. While these items may at first seem obvious or
trivial, experience has shown that the documentation of proper procedures and
a requirement that 'the procedures be followed are very effective in reducing
the number of (preventable) breakdowns in equipment, and miscommunication that
can lead- to unwanted discharges to the sewers. In considering the need for
BMPs and in reviewing the design of BMPs proposed by industry, the following
should be considered:
• Equipment 0 & H. While most facilities yill make every effort to take
care-of the equipment that they have purchased and installed for waste
management purposes, this cannot be assumed to always be the case.
Where equipment is at a level of sophistication that is beyond the
comprehension of its operators, or when the equipment is simply old,
attention paid to operation and maintenance practices becomes all the
more important. In such cases, BMP requirements should be directed at
ensuring that necessary routine maintenance is performed and that
equipment failures are not due to neglect. Where sophisticated elec-
tronics are a part of a treatment system the manufacturers of such
equipment frequently provide either technical training or the option
of equipment maintenance contracts. These services should be encour-
aged by POTW staff wherever appropriate.
• Reduction of contaminated runoff. The potential exists for contami-
nated runotf from any process operation, chemical transfer area, or
raw materials, product, or waste storage area that is exposed to
5-8
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rainfall. Walk through inspections of a facility may reveal telltale
stains on the ground in problem areas. Depending on the nature of the
contamination, this type of runoff may be of concern. If the contami-
nated runoff is readily treated by the lU's pretreatment processes and
does not contribute to hydraulic overloading of the system, then it
may be of little consequence. However, if pollutants (or the flow)
resulting from runoff appear to be a problem, then some form of
mitigation should be considered by the IU. After discussing the
problems and possible solutions with industry staff, the POTV inspec-
tors should leave the selection of remedial measures to industry
management. Mitigative measures might include the construction of
berms and/or diversion structures, the shifting of operations to
covered areas, recontouring of surfaces, or even the modification of
pretreatment systems onsite. The ongoing maintenance and implementa-
tion of runoff control measures are appropriately contained in the
facility's BMP.
Segregation of wastes for reclamation. In some instances, oppor-
tunities will exist to segregate wastes within a facility for the
purpose of reclamation. This practice also reduces the quantities of
possibly hazardous waste that must be disposed and may even reduce
pollutant loadings in the wastewater. Contaminated oils and spent J
solvents are examples of wastes for which a substantial reclamation
market exists.
Routine cleaning operations. Many industries will schedule routine
cleaning of plant areas and equipment. This may conws at the end of
every few shifts, on specified days of the week, or posjsibly at the
end of seasonal operations. While these cleaning activities are
necessary for the continued efficient (and perhaps samittary) nature of
plant operations, the use of large quantities, of detesrgonts and
solvents, and the pollutants carried by these chemicals, can be of
concern. In some instances, it is possible for industries to reduce
the loadings to the sewers through the substitution of dry methods of
cleaning or modification of cleaning procedures. For instance, it is
often possible to achieve highly efficient cleaning of surfaces while
reducing chemical usage by using high pressure application wands.
This type of chemical application also allows for more direct
application and more efficient chemical usage. Vhen reviewing routine
cleaning operations, POTWs should also endeavor to ensure that
requited cleaning of grease traps are indeed conducted with necessary
frequency. Once again, the use of formal procedures., and perhaps even
operations log books could be of help.
Chemical storage practices. A walk through of a facility's process
operations may reveal that chemicals and fuels are b
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5.5 LEGAL AUTHORITY CONSIDERATIONS
All POTWs must have the minimum legal authority required by 40 CFR
403.8(f)(i), to deny or condition discharges of pollutants that could violate
local or Federal pretreatment standards and requirements. The goals of
management practice requirements are the same as those of numerical local
limits — to prevent pass through, interference, and violations of the
specific prohibitions. However, the imposition of the management plans
described in this chapter may or may not be within the scope and authority of
some local ordinances. Therefore, it is suggested that each POTtf specifically
evaluate its legal ability to impose these requirements. Once verified or
obtained, specific requirements for industrial users to submit a management
plan should be included in the user's control mechanism (i.e., industrial user
permit).
5.6 APPROVAL OF INDUSTRIAL USER MANAGEMENT PLANS
Once the need for a chemical management plan, spill prevention plan or
BMP is determined, the POTW may require the plan(s) to be submitted in
conjunction with the industrial user's permit application and approved in
conjunction with issuance of the permit. The industrial user permit should be
reissued to include the requirements of the management plan if necessary.
Satisfactory implementation of the plans should then 1se verified during the
periodic industrial inspections by the POTW.
5-10
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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
(DECEMBER 1987)
.
APPENDIX I - LOCAL LIMITS DERIVATION EXAMPLE
-------
-------
APPENDIX I
LOCAL LIMITS DERIVATION EXAMPLE
In 'this appendix, local limits for a hypothetical POTU are derived.
POTV is a conventional activated sludge plant, with anaerobic sludge
digestion. POTU characteristics are as follows:
This
• POTV influent flow « 3.35 MGD
• POTW sludge flow to disposal =0.01 MGD
•; POTU sludge flow to digester = 0.015 MGD
• Percent solids of sludge to disposal = 7.5%
•i Receiving stream flow = 47 MGD (7Q10)
26 MGD (1Q10)
i
Ih the first section of this appendix, local limits will be derived for
four mietals. The second section of this appendix discusses the identification
of organic pollutants of concern, and details the calculation of local limits
for these organic pollutants.
DERIVATION OF LOCAL LIMITS FOR METALS i
The derivation of local limits for metals (cadmitim, chromium, copper and
lead have been selected as representative) is demonstrated in this section.
The methodology for deriving local limits for these metals entails:
i
• Acquisition of representative removal efficiency data
• Identification of applicable treatment plant/environmental criteria
', and conversion of criteria into allowable headworks loadings
« Allocation of maximum allowable headworks loadings to domestic and
1 industrial sources, thereby setting local limits
; !
Representative Removal Efficiency Data
Representative removal efficiency data are crucial to the development of
allowable headworks loadings. In this section, the acquisition of
1-1
-------
representative metal pollutant removal efficiencies for the hypothetical POTW
is discussed.
The POTU has monitored its effluent and sludge for the metals cadmium and
copper on a monthly basis over the past year. Tables 1-1 and 1-2 present
these monthly effluent and sludge monitoring data, respectively.
Corresponding monthly removal efficiency data can be derived from the monthly
effluent and sludge monitoring data shovn in Tables 1-1 and 1-2. In order to
derive removal efficiencies from the Table 1-1 and 1-2 data, the following
equation can be used:
(CSLDG) (PS/100) «> ) (100)
SLOG •
Err
(CSLDG) (PS/100) (QSLDQ) H. (CBrf
) (QPOTW)
where: R
Err-
SLDG
PS
Err
POTW removal efficiency, percent
Sludge level, mg/kg dry sludge
Percent solids of sludge to disposal
Sludge flow to disposal, MGD
POTW effluent level, mg/1
POTW flow, MGD
This removal efficiency expression was derived from the removal efficiency
equation for metals presented in Section 3.2.4. The above equation is based
upon the assumption for metals that the POTW influent pollutant loading is
equal to the sum of the POTW's effluent and sludge pollutant loadings.
Table 1-3 presents site-specific removal efficiencies derived from the
above removal^ efficiency equation, the Table 1-1 and 1-2 data, and the
following POTW operational data:
• POTW flow .3.35 MGD
• Sludge flow to disposal a 0.01 MGD
• Percent solids of sludge to disposal « 7.5*
1-2
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As surrogates for Table 1-1 pollutant levels designated as below
detection, pollutant levels corresponding to one-half the analytical detection
limit (i.e., Cd * 0.0005 mg/1) were used in the removal efficiency
calculations.
Section 3.2.4.2 of the manual suggests the use of removal efficiency
deciles in deriving allowable headworks loadings. Following these procedures,
the second and eighth removal efficiency deciles for cadmium and copper can be
obtained from the Table 1-3 removal efficiency data. Table 1-4 presents
second and eighth decile removal efficiency data-for these two pollutants, as
well as literature decile removal efficiency data for the additional metals
chromium and lead. The removal efficiencies shown in this table will be used
in deriving allowable headworks loadings for the four metals.
Removal efficiencies for the four metals across primary treatment will
also be needed, to derive allowable headworks loadings based on activated
sludge inhibition threshold data. The POTW conducted an additional monitoring
effort to obtain representative primary removal efficiencies for the four
metals. The result of this effort is the median primary removal efficiency
data shown in Table 1-5. Primary removals varied only slightly from month to
month; as a consequence, the POTW elected to use median primary removals and
did not consider the use of the removal efficiency decile approach to be
necessary.
Derivation of Allowable Headworks Loadings
Having obtained removal efficiency data, allowable headworks loadings are
now derived, .based on the following treatment plant/environmental criteria:
• NPDES permit limits
• Water quality standards
• Activated sludge inhibition data
• Anaerobic digester inhibition data
• Sludge disposal criteria
1-6
-------
TABLE I-4> naBPRBSEWTATIVE REMQVAL, EFFICIENCIESFOR THE
HYPOTHETICAL POTV u - V :
Pollutant
Cd
Cr
Cu !
Pb
Second Decile
Removal
29* "
68Z*
27%
39**
Eighth Decile
Retnoval
'•'•'• -96*' •
'. 9U*
11%
76X*
*Literatu!re value from Table 3-9.
1-7
-------
TABLE 1-5. REPRESENTATIVE PRIMARY TREATMENT
REMOVAL EPPICIENCES FOR THE
HYPOTHETICAL POTW
Pollutant
Cd
Cr
Cu
Pb
Median Removal
Across Primary Treatment
212
3IX
23*
12%
1-8
-------
The derivation of allowable headvorks loadings on each of the
above-listed bases are discussed in this section.
NPDES Permit Limits
The following equation is used to derive allowable headworks loadings
based on NPDES permit limits (from Section 3.2.1.1 of the manual):
where:
(8.34)(C T)(Q
'CRIT ' VWPOTW'
IN
(1-R
POTW'
= Allowable headworks loading, Ibs/d
CRIT = NPDES permit limit, mg/1
POTW
POTW
POTV flow, MGD
decile
efficiency across POTW based on second
The hypothetical POTV has only one metal pollutant NPDES permit limit, a
0.5 mg/1 limit for cadmium. To calculate the corresponding allowable
headworks loading of cadmium for the hypothetical POTV, the following values
have been established: CCRJT = 0.5 mg/1, QpQTW = 3.35 MGD, and RpoTW = 0.29
(from Table 1-4). Thus, the allowable headworks loading for cadmium, based on
the NPDES permit limit, is:
(8.34)(0.5)(3.35)
(1-0.29)
19.7 Ibs/d
Water Quality Standards
The following equations are used to derive allowable headworks loadings
based o(n water quality standards (from Section 3.2.1.2 of the manual):
i
L _ (8.3A)[CeWQ(Q7Q10 * QPOTW)-(C3TRQ7QIO)1
IM/C
IM/A
(8.34){CAwg(Q1Qlo + QpOTW)-(CSTRQlg;lo)J
1-9
-------
where:
IN/C
IN/A
CWQ
7Q10
1Q10
pOTW
POTW
= Allowable headvorks loading based on chronic
toxicity standard, Ibs/d
= Allowable headworks loading based on acute toxicity
standard, Ibs/d
* Chronic toxicity standard, mg/1
= Acute toxicity standard, mg/1
= Lowest 7-day average receiving stream flow over the
past 10 years, MGD
= Lowest single day receiving stream flow over the
past 10 years, MGD
= POTV flow, MGD
= Background (upstream) pollutant level in receiving
stream, mg/1
Removal efficiency across POTW based on second
decile
The POTV contacted the State environmental agency and obtained the
following receiving stream flow data for deriving allowable headworks loadings
based on water quality standards:
-7010
The POTW also obtained, from the State agency the applicable water quality
standards and receiving stream background level data presented in Table 1-6.
The Table 1-6. water quality standards are converted into corresponding allow-
able headworks loadings, by means of the above equations. These calculations
are illustrated below for cadmium:
(8.
. 001)(47 + 3.35)-(0)(47)l
*i»/c " ' (1-0.29) ~~~
4.
(8.3/+)[(0.005)(26 + 3.35)-(0)(26)l
IN/A
(1-6.29)
0.59 Ibs/d
1.72 Ibs/d
1-10
-------
TABLE 1-6. VATER QUALITY STANDARDS AND RECEIVING STREAM
BACKGROUND LEVELS FOR THE HYPOTHETICAL POTtf
Chronic Vater
Quality Standard,
Pollutant:
Cd !
i .
Cr ;
Cu
Pb .
i
mg/1 "
O.'OOl
0.012
0.015
0.005
Acute Vater
Quality Standard,
mg/1
0.005
0.025
0.05
0.008
Receiving Stream
Background Level,
mg/1
0.0*
•0.002
0.003
0.001
^Assumed. No data available.
1-11
-------
The chronic toxicity-based allowable headworks loading (0.59 Ibs/d) is
more stringent and is selected as the POTV's overall water quality standard-
based allowable headworks loading for cadmium.
The water quality standard-based allowable headworks loadings for the
remaining three metals are calculated in an identical fashion. The water
quality standard-based allowable headworks loadings for all four metals are
listed in Table 1-8.
Biological Treatment Process Inhibition
The following equations are used to derive allowable headworks loadings
based on biological treatment process inhibition (from Section 3.2.2.1 of the
manual):
(8.34)(CT
IN/AS
where:
and:
IN/AS
IN/AD
IN/AS
'IN/AS
*POTW
PRIM
IN/AD
'IS/AD
*DI<1
XPOTW
POTW
= Allowable headworks loading based on activated
sludge process inhibitions Ibs/d
= Activated sludge inhibition threshold level, mg/1
= POTW flow, MGD
= Median primary removal efficiency (Table 1-5)
* Allowable headworks loading based on anaerobic
digester inhibition, Ibs/d
* Anaerobic digester inhibition threshold level,
mg/1
- Sludge flow to digester, MGD
3 Removal efficiency across POTV based on eighth
decile (Table 1-4)
The inhibition threshold levels provided in Tables 3-4 and 3-6 of the
text are used'in these calculations. The sludge flow to the digester (QDIG)
is 0.015 MGD.
1-12
-------
Demonstrating the use of the above equations in calculating allowable
headworks loadings for cadmium:
I!|/M)
From Table 3-3, C
From Table 3-6, C
QPOTW =-3.35 MGD
Q3to = 0.015 MGD
RPRIM = 0.21 (Table 1-5)
= 1 mg/1
= 20 mg/1
POTW
0.96 (Table I-<
(8.34(1)(3.35)
-IS/AS (1-0.21)
(8-34)(20)(0.015)
'IN/AD = (0.96)
= 35.4 Ibs/d
= 2.6 Ibs/d
The activated sludge and anaerobic digester inhibition-based allowable
headvorks loadings for all four metals are presented in Table 1-8.
'
Sludge iDisposal Criteria !
j
The POTV land-applies 0.01 MGD of sludge (7.5* consistency) to 500 acres
of cropland (soil pH = 7.0, cation exchange capacity =» 12 meq/lOOg). The site
life is estimated at 20 years. The POTV contacted the State environmental
agency, which advised the POTV that the sludge disposal criteria presented in
Table 1-7 apply to the POTV's current sludge disposal practices.
Tw,o sludge disposal criteria must be compared for each pollutant: 1) the
sludge disposal limit taken directly from Table 1-7, and 2) the corresponding
sludge 'disposal limit based on the cumulative application limit from Table
1-7. Tjhe latter sludge disposal limit is calculated from the following
equation (from Section 3.2.2.2 of the manual):
where:
(CARXSA)
LIM(C) ~ (SL)(QSLDQ)(PS/100)(3046)
CLiM(o 3 Slud8e disposal limit based on cumulative
application rate limit, mg/kg dry sludge
CAR = Cumulative application rate limit; Ibs/acre over
the site life
1-13
-------
TABLE 1-7. SLUDGE DISPOSAL CRITERIA FOR LAND APPLICATION
OP SLUDGE BY THE HYPOTHETICAL POTV
Pollutant
Cd
Cu
Pb
Sludge Limit,
mg/kg dry veight
25
1000
1000
Cumulative Application
Limit, Ibs/acre
8.92
223.1
892.2
1-14
-------
SA
SL
SLOG
PS
= Site area, acres ;
= Site life, years
= Sludge flow to disposal, MGD
= Percent solids of sludge to disposal
Demonstriating the use of this equation for cadmium:
« From Table 1-7, CAR
• SA =500 acres
• SL = 20 years
• QSLDO = °-01 MGD
0 PS = 7.5%
= 8-. 92 Ibs/acre
*LIM< C
(8.92)(500)
(ZO)(0.01)(/'.b/lOO)(3646)
97.6 mg/kg dry sludge
Since th^> sludge disposal limit listed in Table 1-7 (25 mg/kg) is mote
stringenjt than the above-calculated limitation, the 25 mg/kg limit should be
used in deriving the sludge disposal-based allowable headworks loading for
cadmium. Similar calculations show that the sludge disposal limits listed in
Table 1-7 are more stringent for the other two metals as well.
In order to convert a sludge disposal criterion into an allowable
headworks loading, the following equation is used (from Section 3.2.2.2 of the
manual):
whete:
(8.34)(C
SLCRIT
)(PS/100)(QstM)
IN
IN
R
'POTW
Allowable headworks loading, Ibs/d
CSLCRIT * Sludge disposal criterion, mg/kg dry sludge
PS = Percent solids of sludge to disposjil
"SLOG
POTW
= Sludge flow to disposal, MGD i
= Removal efficiency across the POTW, based on
eighth decile
1-15
-------
For cadmium:
From above, C
SLCRIT
25 mg/kg
PS
Q
7.5X
0.01 MGD
SLOG
From Table 1-4, R
POTW
0.70
IN
(8.34)(25)(7.5/100)(0.01)
(0.70)
0.16 Ibs/d
Allowable headworks loadings based on sludge disposal criteria are listed in
Table 1-8 for the three metals.
Table 1-8 presents a comparison of allowable headworks loadings for the
four metals, derived on all five bases. As can be seen from Table 1-8, the
smallest loading for each pollutant is selected as the pollutant's maximum
allowable headworks loading. Local limits are to be derived from these
maximum allowable headworks loadings.
Allocating Maximum Allowable Headworks Loadings
The allocation of maximum allowable headworks loadings entails:
-J
• Incorporation of a safety factor and subtraction of domestic/
background wastewater loadings
• Allocation of resulting maximum allowable industrial loadings to
individual industrial users
Four methods for allocating allowable industrial loadings are
demonstrated l.n this section:
• Uniform concentration method
• Industrial contributory flow method
• Mass proportion method
• Selected industrial reduction method
1-16
-------
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1-17
-------
The uniform concentration method derives limits vhich apply to all industrial
users, whereas the other three methods are lU-specific, in that derived limits
only apply to those industrial users known to be discharging a given
pollutant at greater than the domestic/background level.
Incorporation of a Safety Factor/Subtraction of Domestic Loadings
The following equation is used to convert maximum allowable headworks
loadings into maximum allowable industrial loadings, through 1) the
incorporation of a safety factor, and 2) the subtraction of the total
pollutant loading from domestic/background sources:
ALL
- L
DOM
where:
ALL
MAHL
SF
LOOM
or,
DOM
Maximum allowable industrial loading, Ibs/d
Maximum allowable headworks loading, Ibs/d
• Safety factor, decimal
* Domestic/background wastewater pollutant loading,
Ibs/d (uniform concentration method)
Domestic/unregulated wastewater pollutant loading,
Ibs/d (Ill-specific methods)
It can be seen from the above equation that the domestic/background loading
(LOOH) for each pollutant depends on the allocation method selected. For the
Ill-specific allocation methods, Ills which do not discharge the particular
pollutant are-^considered as background sources, discharging at normal domes-
tic/background pollutant levels. Therefore for the Ill-specific allocation
methods, LOOM for each pollutant includes background pollutant loadings from
these lUs. As a result, LDOH for the Ill-specific allocation methods is
greater than LDOH for the uniform concentration allocation method.
Table 1-9 presents a summary of industrial user and domestic/background
wastewater flow, concentration, and pollutant loading data for the hypotheti-
cal FOTV. The distinction between the two types of domestic/background
1-18
-------
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1-19
-------
vastewater loadings is evident from the Table 1-9 data; the domestic/back-
ground loadings for the Ill-specific method are increased to account for
industrial user background loadings. The amount of this increase equals the
flow from those industries not discharging the pollutant times the domestic
vastevater background concentration.
The calculation of maximum allowable industrial loadings, using domestic/
background pollutant loading data from Table 1-9, is demonstrated below for
cadmium:
•
t
•
•
From Table 1-8, L,
From Table 1-9, L
MAHL
DON
3 0.16 lbs/d
0.044 lbs/d (Uniform Concentration Method)
From Table 1-9, LDOM = 0.054 lbs/d (lU-specific methods)
SF = 0.10 (ten percent safety factor assumed)
ALL
ALL
(1-0.10H0.16) - 0.044
Concentration Method)
(1-0.10)(0.16) - 0.054
methods)
0.10 lbs/d (Uniform
0.09 lbs/d (lU-specific
Table 1-10 presents maximum allowable industrial, loadings for the four
metals. These loadings were derived from the above equation, incorporating a
ten percent safety factor and using the domestic/background pollutant loading
data presented in Table 1-9.
Allocation of Maximum Allowable Industrial Loadings
Table 1-11 to 1-13 present local limits for each of the hypothetical
POTW's industrial users, derived by application of the four industrial loading
allocation methods discussed in Chapter 3 of the manual. The equations and
calculations pertinent to the derivation of these local limits are discussed
in the following sections.
Uniform Concentration Allocation Method
The uniform allocation method derives local limits which apply to all
three of the hypothetical POTU's industrial users. The equation for this
method is (from Figure 3-2 of the manual):
•ALL
(8.34)(QIMD)
1-20
-------
TABLE 1-10. MAXIMUM ALLOWABLE INDUSTRIAL
LOADINGS, LBS/D
Pollutant
Cd
Cr
Cu
Pb
Uniform
Concentration
Method
0.10
10.34
2.19
IU-Specific
Allocation
Methods
0.09
10.02
I
4.01
; 2.13
1-21
-------
TABLE 1-11. LOCAL LIMITS FOR THE HYPOTHETICAL CHEMICAL MANUFACTURER
Uniform
Pollutant
Cd
Cr
Cu
Pb
Concentration
0.02
r.oa
0.67
0.35
Local Limit, mg/1
Industrial Mass
Contributory* Proportion*
Selected
Industrial
Reduction**
0.82
0.89
*Local limits not derived for pollutants discharged by the IU at levels below
the domestic sewage background concentration. The IU would be notified that
it is not. allowed to increase its discharge above the domestic sewage
background level.
**Calculation of limits by the selected industrial reduction method is
illustrated for lead only.
1-22
-------
TABLE 1-12. LOCAL LIMITS FOR HYPOTHETICAL EQUIPMENT REliUlLDBR
local Limit, mg/1
[Pollutant;
Cd :
Cu
Uniform
Concentration
0.02
1.68
0.67
0.35
Industrial
Contributory*
0.13
5.01
0.82
1.06
Mass
Proportion*
0.13
8.35
0.44
1.87
Selected
Industrial
Reduction**
1.0
*Local limits not derived for pollutants discharged by the IU at levels below
the domestic sewage background concentration. The IU would be notified thatt
it is not allowed to increase its discharge above the domestic sewage
background level.
|**Calculation of limits by the selected industrial reduction method is
illustrated for lead only.
1-23
-------
TABLE 1-13. LOCAL LIMITS FOR HYPOTHETICAL CERAMIC MANUFACTURER
Industrial User:
Pollutant
Cd
Cr
Cu
Pb
Uniform
Concentration
0.02 . .
1.68 ..
0.67 .
0.35
Local Limit, mg/1
Industrial Mass
Contributory* Proportion*
5.01
1.06
3.17
0.62
•Selected
Industrial
Reduction**
1.0
*Local limits .not derived for pollutants discharged.by the IU at 'levels below
the domestic sewage background concentration. The IU would be notified that
it is not allowed to increase its discharge above the domestic sewage
background level.
**Calculation of limits by the selected industrial reduction method is
illustrated for lead only.
1-24
-------
where:
LIM
= Uniform concentration limit, mg/1
LXLL = Maximum allowable industrial loading, Ibs/d
IND
Total industrial flow, MGD
As an example, for chromium:
. L.
ALL
lbs/d
Table 1-
= 0.74 MGD (Table 1-9)
(10.34)
(8.34)(0.74)
1.68 mg/1
This limit applies to all three industrial users of the hypothetical POTtf (See
Tables 1-11 to 1-13).
Industrial Contributory Flov Method
The industrial contributory flow method derives local limits which apply
only to those industrial users discharging the particular pollutant at greater
than the normal background concentration in domestic sewage. The equation for
this method is (from Figure 3-2 of the manual):
ALL
(8.34)(Q
CONT'
where:
'LIM
ALL
*CONT
Industrial contributory flow-based limit, mg/1
Maximum allowable industrial loading, lbs/d
Industrial contributory flow, MGD
As an example, for chromium:
ALL
10.02 lbs/d (See Table 1-10)
} _ - flow from chromium dischargers
0.24 MGD (See Table 1-9)
0.085 + 0.155
10.02
(8.34)(0.24)
5.01 mg/1
1-25
-------
This limit applies only to the hypothetical equipment rebuilding and ceramic
manufacturing industrial users. (See Tables 1-11 to 1-13).
Mass Proportion Method
The mass proportion method allocates allowable industrial loadings to
individual lUs in direct proportion to each Ill's current pollutant loading.
This allocation method is also lU-specific. The equation for this method,is
(from Figure 3-2 of the manual):
vhere:
LIM< X )
LIM< x
ALL
CURR(X)
CURRt t )
'( X )
'cURRIx)CURR(t) '
(8.34)(Q(x))X LALL
Local limit for industrial user (x), mg/1
Maximum allowable industrial loading, Ibs/d
Current loading from industrial user (x), Ibs/d
Total industrial loading, Ibs/d
Industrial user (x) discharge flow, MGD
As an example, for chromium:
ALL
CURR(t)
Equipment Rebuilder:
L.
CURRIX)
10.02 Ibs/d (Table 1-10)
2.69 Ibs/d (Table 1-9)
1.59 Ibs/d
0.085 MGD
(1.59/2.69)
) * (8.34)(0.085)
Ceramic Manufacturer:
x (10.02) =* 8.35 mg/1
^t x >
(1.10/2.69)
= 0.155 MGD
'LIMIX)
(8.34K6.15)
(10'02) ' 3'17
1-26
-------
I ! i
The above limits apply only to the industrial users indicated (See tables i>il
to 1-13).! i
Selected Industrial Reduction Method ;
The Selected industrial reduction method is based upon the reduction of
current industrial user discharge loadings by the installation of treatment
technologies. As an example of the application of this method, selected
industrial reduction limits for lead'vill be derived in this section.
I -•-'','
From Table 1-9, the current total industrial loading of lead is 4.28
Ibs/d. The maximum allowable industrial loading, from Table 1-10, is 2.13
Ibs/d. The required industrial loading reduction is:
\ 4.28 Ibs/d - 2.13 Ibs/d = 2.15 Ibs/d
Appendix ,L (Table L-l) 'and Table 6-1 in Chapter 6 document that a reduction of
lead to less than 1.0 mg/1 can be achieved through the installation of
precipitation technologies. This concentration limit may be imposed upon the
POTW's current lead dischargers as long as it results in the minimum required
industrial loading reduction of 2.15 Ibs/d. That this loading reduction can
be achieved with a 1.0 mg/1.limit is demonstrated as follows:
• For the equipment rebuilder, current lead loading = 2.66 Ibs/d (from
table 1-9)
| At 1.0 mg/1, the lU's lead loading is reduced to:
(8.34)(1.0 mg/l)(0.085 MGD) - 0.71 Ibs/d
The lead loading reduction effected by the equipment rebuilder equals:
! . 2.66 Ibs/d - 0.71 Ibs/d = 1.95 Ibs/d
• For the ceramic manufacturer, current lead loading
Table 1-9)
At 1.0 mg/1, the lU's lead loading is reduced to:
<8.34)<1.0 mg/l)(0.155 MGD) - 1.29 Ibs/d
1.62 Ibs/d (from
1-27
-------
The lead loading reduction effected., by the ceramic manufacturer .-
equals:
1.62 Ibs/d - 1.29 Ibs/d = 0.33 Ibs/d
• The combined lead loading reduction brought about by the two
industrial users equals:
1.95 Ibs/d + 0.33 ,lbs/d. = 2,.28 Ibs/d .-
Since this lead loading reduction of,2.28 Ibs/d exceeds the required loading
reduction of 2.15 Ibs/d, the 1.0 mg/. lead limit may be imposed upon the
equipment rebuilder and the ceramic .manufacturer'(see Tables 1-11 to 1-13).
DERIVATION OF LOCAL LIMITS FOR ORGANICS ,
The derivation of organic pollutant local limits for the hypothetical
POTW entails:
i
* Identification of organic pollutants of concern for which local limits
may be needed
• Derivation of maximum allowable headworks loadings
• Allocation of maximum allowable headworks loadings
• Establishing local limits to address pollutant flammability/
explosivity and fume toxicity concerns
Each of the above tasks are discussed in the following sections.
Identification of Organic Pollutants of Concern
The firs.t step in deriving organic pollutant local limits for the
hypothetical POTVwill be to identify organic pollutants of concern for which
local limits may be needed. As discussed in Chapter 2 of this manual, the
first step involves completion of a thorough industrial user survey which
identifies chemicals used, produced, stored, or disposed by the Ills. Then,
sampling of IU discharges and at the POTV is performed to screen for the
presence of those pollutants reasonably expected to be present in significant
quantities. Based on the results of this preliminary sampling, some quick
rules of thumb may be used to determine whether more extensive coordinated
1-28
-------
influent/effluent/sludge sampling for particular pollutants is needed to
!
provid^ data necessary for calculation of local limits. For uxarnple, the
following conservative rules of thumb could be used to decide vhich pollutants
vould warrant further consideration:
•j Vater quality-based local limits - Does the result of a receiving
; stream dilutional analysis based on maximum POTV effluent concen-
tration exceed State water quality standards? j
•; Inhibition-based local limits - Does the maximum POTV influent grab
sample concentration exceed one-half, or the maximum POTV influent
; 24-hour composite sample concentration exceed one-fouirth, of the
'. activated sludge inhibition threshold level?
Does the maximum POTW influent concentration exceed one five-hundredth
of the anaerobic digester inhibition threshold level?
•, Sludge disposal criteria-based local limits - Does thia maximum
concentration of the pollutant in POTW sludge exceed one-half of the
State sludge disposal criterion?
•! Flammability/explosivity and fume toxicity-based local limits - Are IU
! discharge levels in excess of flammability/explosivity - and/or fume
: toxicity-based discharge screening levels?
The above pollutant evaluation scheme is based on the chemical-specific
approach to identifying pollutant of concern, discussed in Section 2.3.3.1 and
Figure 2-2 of the manual, and the flammable/explosive and fume toxic pollutant
screening techniques discussed in Sections 4.1.1.5 and 4.2.3 of the manual.
This evaluation scheme focuses on POTV influent and IU discharge data, but
also incorporates the use of effluent and sludge data. As discussed in
Section 2.3.3.1 of the manual, the POTV should perform at least a limited
amount of effluent and sludge monitoring as part of its preliminary sampling
program, in otder to screen for pollutants which have concentrated to
detectable levels in effluent or sludge even though not detectable in the
influent. !
' I
Table 1-14 and 1-15 summarize organic pollutant monitoring data for the
hypothetical POTV's influent and effluent, respectively, and Table 1-16
summarizes organic pollutant monitoring data for the POTV's principal
industrial user, an organic chemical manufacturing facility. The monitoring
data presented in these tables will be used in demonstrating the above-
described pollutant evaluation scheme. The application of each step of the
pollutant evaluation scheme is demonstrated in the following sections.
1-29
-------
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1-33
-------
Screening o£ Organic Pollutants on the Basis of Water Quality Standards
The first step of the evaluation scheme consists of a receiving stream
dilutional analysis to identify pollutants of potential vater quality concern.
The equation for conducting this dilutional analysis is as follows:
'POTW
where:
PROJ
PROJ
EFF
"POTW
'STR
*STR
= Projected downstream level, mg/1
= Maximum POTW effluent level, from Table 1-15, mg/1
= POTV flow, HGD
= Receiving stream flow, MGD
- 7Q10 flow for comparison to chronic criteria
- 1Q10 flow for comparison to acute criteria
Projected downstream levels calculated from the above equation are compared
with State water quality standards. Table 1-17 presents organic pollutant
State water quality standards for the POTW.
-J
The screening technique is demonstrated below for chlorobenzene:
••POTW
Chronic:
Acute:
'EFF
PROJ
'PROJ
3.35 HGD
47 HGD (7Q10)
26 MGD (1Q10)
23 mg/1 (Table 1-15)
3.35
23 x (
23 x (
3.35 + 47
3.35
3.35 + 26:
) = 1.5 mg/1
2.6 mg/1
Table 1-17 indicates that the chronic water quality standard for chlorobenzene
is 0.026 mg/1 and the acute standard is 0.59 rag/1. Since the above-derived
projected in-stream levels exceed these water quality standards, the develop-
ment of water quality-based local limits for chlorobenzene is warranted.
1-34
-------
TABLE 1-17. ORGANIC POLLUTANT WATER QUALITY STANDARDS F01R THE POTV
Pollutant
Acetone '.
Chlorobenzene
Chlorofo;rm
Ethylben|zene
Methylente Chloride
Phenol
Toluene ;
Nitrobenzene
Acute
Water
Quality
Standard, mg/1
550
0.59
1.8
1.4
9.7
5.3
2.4
27.0
Chronic
Water
Quality
Standard, mg/1
78
I 0,026
0.079
0.062
| 0.43
i 0.37
i
1.7
I ;
i ._ *
*No standard available.
1-35
-------
Based on this screening technique, the .POTW determined that water
quality-based local limits should be developed for the following organic
pollutants:
S :
• Chlorobenzene
• Ethylberizene
Screening of Organic Pollutants on the Basis of Biological Process Inhibition
The second step of the pollutant evaluation scheme entails the comparison
of POTW influent levels of organic pollutants with activated sludge and
anaerobic digester inhibition threshold data, as follows:
• Maximum level in grab sample of POTW influent compared with one-,half
of the activated sludge inhibition threshold
• Maximum level in composite sample compared with one-fourth of the •'
activated sludge inhibition threshold
• Maximum POTW influent level compared with one-five hundredth of the
anaerobic digester inhibition threshold
Activated sludge inhibition data are provided in Table 3-2 of the manual.
Comparing POTW influent data from Table 1-14 with inhibition threshold cutoffs
derived from the Table 3-2 data: ->
Pollutant
Ethylbenzene
Nitrobenzene
Phenol
Toluene
Maximum
Grab Sample
Level, mg/1
0.003
Not detected
0.002
0.008
One-half
of Inhibition
Threshold,
mg/1
100
15
25
100
Maximum
Composite
Sample Level,
mg/1
One-fourth of!
the Inhibition
Threshold,
mg/1
0.005
0.28
0.036
0.043
50 11
7.5 111
12.5 11
50 11
The above-listed organics are present in the POTW influent at levels well
below their corresponding cutoffs. Local limits for these organics need not
be developed from activated sludge process inhibition data.
1-36
-------
Talble 3-5 of the manual presents anaerobic digester threshold inhibition
data. Comparing maximum POTW influent levels with anaerobic digester
inhibition cutoffs derived from Table 3-5 data:
Pollutant
Chlorobenzene
Chloroform
He'thyl Chloride
Maximum Influent
Level, mg/1
1.16
0.38
3.48
One-five hundredth
of the Digester
Inhibition Level, mg/1
0.002
0.002
0.007
All three pollutants are present in the POTW influent at levels in excess of
their cutoffs. Based on this screening analysis, local limits! based on
anaerobic digester inhibition may be needed for all three pollutsints. The
POTW should therefore perform the additional sampling necessary t:o perform a
headwords loading analysis. It would also be wise for the POTW to sample for*
pollutants in the digester to determine whether inhibition threshold levels
are currently exceeded.
Screening of Organic Pollutants on the Basis of Sludge Disposal Criteria
The hypothetical POTW contacted the State environmental agency to
determine if any State sludge disposal guidelines had been established for
organic pollutants in land-applied sludge. The POTW was informed that State
sludge! disposal guidelines for organic pollutants had not beem established.
The hypothetical POTW concluded that without sludge disposal criteria, no
basis 'existed for a sludge disposal criteria analysis.
Screening of Organic Pollutants Based on Flammability/Explosivity and Fume
Toxicity ~ ~ ~~:
, • I
The final step of the pollutant evaluation scheme is to compare
industrial user discharge levels with IU discharge screening levels based on
pollutant flammability/explosivity and fume toxicity. These screening levels
are developed as per the methodologies presented in Sections 4.1.1.5 and 4.2.3
i
of the manual.
1-37
-------
Table 1-18 presents a comparison of IU discharge levels (from Table 1-16)
with discharge screening levels developed in accordance with the Section
4.1.1.5 and Section 4.2.3 methodologies. The comparison suggests that fume
toxicity-based local limits may be needed for the following pollutants:
o Chlorobenzene
o Chloroform ,
o Ethylbenzene
o Methyl chloride
o Nitrobenzene
The comparison also suggests that flammability/explosivity-based local limits
may be needed, for methyl chloride.
Derivation of-Maximum Allowable Headworks Loadings
The pollutant evaluation scheme identified the following pollutants for
which allowable headworks loadings should be developed:
Water Quality-based Headvorks Loadings
o Chlorobenzene
o Ethylbenzene J
Anaerobic Digester Inhibition-based Headworks Loadings
o Chlorobenzene
o Chloroform
o Methyl chloride
Earlier in this appendix, allowable headworks loadings for metals were derived
from State water quality standards. The same procedures can be followed here
to derive water quality-based allowable headworks loadings for Chlorobenzene
and ethylbenzene. Based on the following data:
o Receiving stream flow, 7Q10 = 47 MGD
o Receiving stream flow, 1Q10 = 26 MGD
o POTtf. flow =3.35 MGD
1-38
-------
TABLE 1-18.
COMPARISON OP III DISCHARGE LEVELS VTIH
IU DISCHARGE SCREENING LEVELS
Pollutant
Chlorobenzene
|
Chloroform
Ethylbenzene
Methyl Chloride
Methylene Chloride
Nitrobenzene
Phenol
Toluene;
Aniline
N,N-Dimethylaniline
Methyl Acetate
Methyl ;Ethyl Ketone
Methyl 'Isobutyl Ketone
Maximum IU
Discharge
Level, mg/1
13.8
0.9
12.2
39.27
2.4
34.0
17.0
0.62
108.0
4.0
1.7
0.9
0.15
Flammability/ !
Explosivity- Fume Toxicity-
Based Screening Based Screening
Level, mg/1 Level, mg/1
403.
_ *
158.
11.
5760.
98035.
_ *
173.
2.35
0.42
1.59
0.007
4.15
5.41
688.4
1.35
712086. . 143.9
_ * 71.4
21531. 1^0.0
24848. 249.0
24601. 88.0
*Screening level not developed (LEL data not available)
1-39
-------
• Receiving stream background levels = 0 (i.e., not available)
• Chlorobenzene chronic standard ,« 0.026 mg/1
• Chlorobenzene acute standard =0.59 mg/1
• Ethylbenzene chronic standard = 0.062 mg/1
• Ethylbenzene acute standard =1.4 mg/1
• Chlorobenzene removal efficiency = 90%*
• Ethylbenzene removal efficiency = 67% (Table 3-10)
Allowable headworks loadings of 109.2 Ibs/d Chlorobenzene and 78.9 Ibs/d
ethylbenzene are derived.
The following equation is used to derive allowable headworks loadings for
organic pollutants based on anaerobic digester inhibition data (from Section
3.2.2.1 of the manual):
IH
LINF x
(8.34)(QpQTW)(C )
IMF '
x C
DIG )
CHIT
where:
IN
INF
CRIT
'DIG
*POTH
IMF
Allowable headworks loading, Ibs/d
POW influent pollutant loading, Ibs/d
v
Anaerobic digester inhibition threshold level, mg/1
Pollutant level in sludge to digester, mg/1
POTV flow, MGD
POTW influent level, mg/1
Table 3-11 presents anaerobic digester inhibition levels (Cc ) for
incorporation into the above expression; however, CL.../C,. data must be
X If F DIG
obtained through site-specific monitoring. CDIO data are not currently
available for the hypothetical POTW. For the three pollutants of concern
(Chlorobenzene, chloroform, methyl chloride), the hypothetical POTW should
perform coordinated monitoring of the POTW influent and the sludge to the
digester, in order to obtain CINy/CDI(J data for incorporation into the above
expression.
*From Reference [19].
1-40
-------
Allocation of Maximum Allowable Headworks Loadings
Requisite pollutant loading reductions for nonconservativcs pollutants can
be calculated from the following equation:
" L
iu (100)
where:
INF
IN
Requisite pollutant loading reduction, percent
Current POTV influent loading of the pollutant,
Ibs/d
Maximum allowable headvorks loading, Ibs/d
Use of ' the above equation requires that the current POTV influent loading of
the particular pollutant exceeds the maximum allowed (L,Kr > L1H>-
The application of the above equation is demonstrated below for
chlorobenzene:
Recent composite sampling of the hypothetical POTV quamtified the
current POTV influent level of chlorobenzene at A. 50 mg/1. Therefore!
J
I (8.34)(3.35)(4.50) - 125.7 Ibs/d
o! Uncontrollable sources of chlorobenzene have been assitssud to be
' negligible
o The allowable headworks loading for chlorobenzene (wat:er quality-
based), is 109.2 Ibs/d
o Required removal is:
i i
125.7 - 109.2
R . (100) - 13.IX
125.7
o The hypothetical POTV's chemical manufacturing IU is the only known
discharger of chlorobenzene to the POTV. For this IU:
- Discharge flow - Q(X, - 0.5 MGD
- Discharge level - LCURR(X, - 13.8 mg/1 (Table 1-16)
T) , (8.34XQ(X)XLCORR(X))
(8.34)(0.5)(13.8) - 57..S Ibs/d
1-41
-------
o The lU's chlorobenzene discharge limit is derived as follows:
CURRtX
, - (1 -
'LIMIx)
"LIMlX)
57.5 - (1 - 0.131)
(8.34)(0.5)
12.0 mg/1
The above minimum discharge limit should be incorporated into the industrial
user's permit.
This minimum industrial reduction may need to- be increased further to
account for domes tic/background sources if the assumption that these sources
are negligible is not accurate. These limits should be reassessed during
routine evaluation of local limit effectiveness. If subsequent evaluation of
the actual influent loading indicates insufficient reduction has been
achieved, the POTW should consider whether the industrial reduction needs to
be increased.
Local Limits to Address Pollutant Flammability/Explosivitv and Fume Toxicity
Concerns '
The pollutant evaluation scheme determined that the hypothetical POTW's
chemical manufacturing IU is discharging potentially ^fume toxic levels of the
following five pollutants:
o Chlorobenzene
o Chloroform
o Ethylbenzene
o Methyl chloride
o Nitrobenzene
The POTW decided to adopt the Cincinnati MSD volatile organic pollutant
local limit procedure (See Sections 4.1.1.2 and 4.2.1, and Appendix J) and
impose a volatile organic pollutant local limit on the chemical manufacturer's
discharge. The MSD volatile organic pollutant local limit consist of a 300
ppm hexane equivalent limit on volatile organics in headspace gases collected
over an equilibrated wastewater sample.
1-42
-------
In addition to imposing the volatile organic pollutant local limit, the
POTW has planned a comprehensive inspection of the chemical manufacturer's
industrial processes. This inspection is to identify IU chemical management
practice deficiencies which might account for the presence of the above-listed
volatile organics in the lU's discharge. The POTW plans to impose chemical
management practice requirements on the IU to correct these deficiencies and
prevent1 the IU from discharging flammable/explosive and fume toxic levels of
the five organics.
1-43
-------
-------
APPENDIX F
WATER QUALITY-BASED TOXICS CONTROL
-------
-------
WATER QUALITY-BASED TOXICS CONTROL
In addition to compliance with section 301(h) of the Clean Water Act and its
implementing regulations, permits issued to facilities with 301(h) waivers must also ensure
compliance with other appropriate sections of the CWA. Among these is section 301(b)(l)(C),
which tequkes, in part, the imposition of any conditions necessary to meet water quality
standards. Regulations that implement section 301(b)(l)(C) are found at 40 CFR 122.44(d), and
the following discussion highlights some of the requirements of those regulations. This appendix
is not intended as a comprehensive statement of NPDES permitting requirements. Rather, the
information is presented as an overview to advise the 301 (h) applicant of some of the additional
CWA requirements and to guide the applicant to requkements similar or complementary to the
301 (h) requkements.
Under 40 CFR 122.44(d), NPDES permits must contain limitations to control all pollutants
or pollutant parameters that are or may be discharged at a level -which will cause, have
reasonable potential to cause, or contribute to an excursion above any state water quality
standard, including state narrative criteria for water quality. The regulations requke these
evaluations to be made using procedures that account for existing controls on point and nonpoint
sources of pollution, the variability of the pollutant in the effluent, species sensitivity (for
toxicity), and, where appropriate, dilution in the receiving water. The limits must be stringent
enough! to ensure that water quality standards are met and must be consistent with any available
wastelqad allocation.
;The regulations also specifically address when toxicity and chemical-specific limits are
required. A toxicity limit is requked whenever toxicity has the reasonable potential to cause or
contribute to an excursion above either a numeric or narrative standard for toxicity. The only
exceptibn is where chemical-specific limits will achieve the narrative standard. A chemical-
specific limit is requked whenever an individual pollutant is at a level of concern [as defined at
40 CFR 122.44(d)(l)] relative to the numeric standard for that pollutant.
;40 CFR 122.44(d)(l)(vi) outlines the options to be used to interpret a state narrative
criterion hi the absence of a numeric criterion for a pollutant. Under the fkst option, the
permitting authority [in the case of 301(h) modified NPDES permits, EPA] may use a criterion
that is | derived based on a proposed state criterion or an explicit state policy or regulation
interpreting its narrative criterion, supplemented with other relevant information. The second
option is to establish effluent limitations based on EPA's water quality criteria. Finally, the
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permitting authority may establish limits on an indicator pollutant, provided that certain
conditions are met.
EPA's Technical Support Document for Water Quality-based Toxics Control (U.S. EPA
199la) provides guidance for evaluating "reasonable potential" and establishing water quality-
based effluent limits for specific chemicals, as well as whole effluent toxicity. Although the
whole-effluent toxicity discussions focus primarily on fresh water, the approach outlined in U.S.
EPA (1991a) is appropriate for marine waters as well.
In addition to the Technical Support Document for Water Quality-based Toxics Control,
EPA has published several manuals that provide guidance for conducting whole-effluent toxicity
testing and for addressing any toxicity that is found. Methods for Measuring the Acute Toxicity
of Effluents and Receiving Waters to Freshwater and Marine Organisms, 4th ed. (U.S. EPA
1991b) addresses acute (e.g., rapid response) toxicity. EPA's Short-term Methods for Estimating
the Chronic Toxicity of Effluents and Receiving Waters to Marine andEstuarine Organisms (U.S.
EPA 1988a) provides protocols for conducting chronic (e.g., long-term) testing.
If toxicity is found in an effluent, the permittee will be required to conduct a toxicity
identification evaluation (TIE) and,-if appropriate, a toxicity reduction evaluation (TRE) to
control toxicity. Two EPA manuals, Toxicity Identification Evaluations: Characterization of
Chronically Toxic Effluents, Phase 1 (U.S. EPA 1991c) and Toxicity Reductions Evaluation
Protocols for Municipal Waste-water Treatment Plants (U.S. EPA 1988b), address TIE/TRE
procedures for POTWs.
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; REFERENCES
U.S. EPA. 1988a. Short-term methods for estimating the chronic toxiicity of effluents and
receiving waters to marine and estuarine organisms. EPA 600/4-87-028. U.S. Environmental
Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, OH.
U.S. EPA. 1988b. Toxicity Reductions Evaluation Protocols for Municipal Wastewater Treatment
Plants.1 EPA 600/2-88/062. U.S. Environmental Protection Agency.
U.S. EPA. 1991a. Technical support document for water quality-based toxics control. EPA
505/2-90-001. U.S. Environmental Protection Agency, Office of Water, Washington, DC.
! ,i
U.S. EPA. 199Ib. Methods for measuring the acute toxicity of effluents to freshwater and
marine: organisms. 4th ed. EPA 600/4-90-027. U.S. Environmental Protection Agency,
Environmental Monitoring and Support Laboratory, Cincinnati, OH. i
U.S. EPA 1991c. Toxicity Identification Evaluations: Characterization of Chronically Toxic
Effluents, Phase 1. EPA 600/6-91-005F. U.S. Environmental Protection Agency.
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