EPA CONTRACT NO. 68-C8-0001
TC-4110
DRAFT REPORT
AMENDED SECTION 301 (h)
TECHNICAL SUPPORT
DOCUMENT
JANUARY 1991
PREPARED FOR:
OMEP
MARINE OPERATIONS DIVISION
OFFICE OF MARINE AND ESTUARINE PROTECTION
U.S. ENVIRONMENTAL PROTECTION AGENCY
WH-556F
WASHINGTON, DC 20460

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                                  PREFACE
     The  following  1s a  draft amended technical support  guidance document
for  the  Clean  Water  Act  Section  301(h)  program.    When finalized,  this
guidance  document will  completely  supercede the  earlier Revised  Section
301(h) Technical Support Document.

     This  guidance   document,  when  finalized,  will   provide  municipal
dischargers  and  the  U.S.  Environmental  Protection  Agency personnel  with
technical  guidance on  preparing  and evaluating  applications  for  Section
301(h)  modified permits.   One  of the primary  purposes for  revising this
guidance document Is  to  add guidance concerning  proposed revisions to EPA's
Section 301(h)  regulations  (Part  125,  Subpart 6) that the Agency Intends to
promulgate 1n  the near  future.   EPA  1s  revising the Section  301(h)  regu-
lations  primarily to Implement  new Section 301(h) requirements Imposed by
the Water Quality Act of 1987.

     This guidance document, when  finalized,  will be  a general  statement of
policy.   It  will not establish  or affect legal  rights  or  obligations.   It
will not  establish  a  binding norm  and will  not  be  finally determinative of
the Issues addressed.  Agency  decisions  1n  any particular case will be made
by  applying  the  law  and  regulations  on the basis  of  specific  facts  and
actual actions.
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                                 CONTENTS
                                                                        Paoe
PREFACE                                                                  11
LIST OF FIGURES '                                                        v11
LIST OF TABLES                                                         viil
EXECUTIVE SUMMARY                                                         x
INTRODUCTION                                                              1
    BACKGROUND                                                            3
    PURPOSE AND SCOPE                                                     8
STATUTORY CRITERIA AND REGULATORY REQUIREMENTS                           11
       PART 122                                                          16
       PART 125 Subpart G                                                17
DEMONSTRATIONS OF COMPLIANCE BY PERMITTEES                               27
    APPLICATION FORMAT                                                   28
    REQUIRED DATA                                                        30
    APPROPRIATE ANALYSES AND PRESENTATION OF RESULTS                     30
I.  Introduction                                                         32
II. General Information and Basic Data Requirements                      34
    A. Treatment System Description                                      34
       1.  Current, Improved or Altered Discharge                        34
       2.  Description of Treatment/Outfall System                       35
       3.  Primary or Equivalent Treatment Requirements                  36
       4.  Effluent Limitations and Characteristics                      37
       5.  Effluent Volume and Mass Emissions                            39
       6.  Average Daily Industrial Flow                                 40
                                    Hi

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       7.  Combined Sewer Overflows                                      41
       8.  Outfall/D1ffuser Design                                       41

    B. Receiving Utter Description                                       43

       1.  Discharge to Ocean or Saline Estuary                          43
       2.  Discharge to Stressed Haters                                  44
       3.  Seasonal Circulation                                          45
       4.  Oceanographlc Conditions                                      46
       5.  Previously Discharged Effluent                                48
       6.  Ambient Hater Quality Conditions during Maximum
           Stratification                                                49
       7,  Steady-state Sediment Dissolved Oxygen Demand and Oxygen
           Demand due to Sediment Resuspenslon                           53

    C. Biological Conditions                                             53

       1.  Representative Biological Communities                         55
       2.  Distinctive Habitats of Limited Distribution                  57
       3.  Commercial and Recreational Fisheries                         59

    D. State and Federal Laws                                            60

       1.  Applicable Water Quality Standards                            60
       2.  Hater Use Classification                                      60
       3.  Hater Quality Criteria at the ZID under Critical Conditions   61
       4.  Consistency with Coastal Zone, Marine Sanctuary, and
           Endangered Species Laws                                       62
       5.  Consistency with oMer Stat* and Federal Laws                 63

III.   Technical Evaluation                                              64

    A. Physical Characteristics of Discharge                             64

       1.  Critical Initial Dilution                                     64
       2.  Dimensions of the ZID                                         67
       3.  Effects of Ambient Currents and Stratification on
           Dilution and Transport of the Hastefield                      69
       4.  Significant Sedimentation of Suspended Solids                 72
       5.  Sedimentation of Suspended Solids                             72

    B. Compliance with Applicable Hater Quality Standards                73

       1.  Dissolved Oxygen                                              73
       2.  Farfield Dissolved Oxygen Depression                          74
       3.  Dissolved Oxygen Depression doe to Steady Sediment Demand
           and Sediment Resuspension                                     74
       4.  Suspended Solids                                              75
       5.  pH                                                            75
       6.  Compliance with^Applicable Hater Quality Standards            79
       7.  Compliance with Subpart 125.61(b)(2)                          80


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C. Impact on Public Hater Supplies                                   80

   1.  Presence of a Public Water Supply Intake                      80
   2.  Effects on Such Intake                                        81

D. Biological Impact of Discharge                                    81

   1.  Presence of a BIP                                             84
   2.  Effects on Distinctive Habitats of Limited Distribution       88
   3.  Effects on Commercial and Recreation*} Fisheries              90
   4.  Other Impacts Hi thin or Beyond the ZID                        93
   5.  Other Impacts for Discharges into Saline Estuarine Haters     96
   6.  Compliance with Subparts 125.62(a)-(
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EVALUATIONS OF COMPLIANCE BY U.S. EPA                                   133
    DETERMINATIONS OF COMPLIANCE WITH SECTION 301(h)  MODIFIED
    PERMIT CONDITIONS                                                   133
    DETERMINATIONS OF COMPLIANCE WITH 301 (h) CRITERIA                   136
    EVALUATIONS OF PREDICTED CONDITIONS AND PREDICTED CONTINUED
    COMPLIANCE                                                          142
RE ISSUANCE OR TERMINATION OF SECTION 301(ti) MODIFIED PERMITS            146
    PROCEDURES FOR REGULATORY ACTION                                    146
    REGULATORY OPTIONS                                                  147
REFERENCES                                                              149
APPENDICES
    APPENDIX A:  PHYSICAL ASSESSMENT
    APPENDIX B:  WATER QUALITY ASSESSMENT
    APPENDIX C:  BIOLOGICAL ASSESSMENT
    APPENDIX D:  NAVIGATIONAL REQUIREMENTS AND METHODS
    APPENDIX E:  URBAN AREA PRETREATMENT PROGRAM REQUIREMENTS
    APPENDIX F:  WATER QUALITY-BASED TOXICS CONTROL
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                                  FIGURES
Number                                                                  Page
  1     Wastefleld generated by a simple ocean outfall                   65
  2     01ffuser types and corresponding ZID configurations              68
  3     Generalized depiction of changes In species numbers, total
        abundances, and total blomass along a gradient of organic
        enrichment                                                      140
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                                   TABLES
Number                                                                  Page
  1     Estimated pH values after  Initial dilution                       77
  2     Toxic pollutants  and pesticides  as defined 1n Subparts
        125.58(aa) and  (p)                                              117
  3     Summary of U.S. EPA marine water quality criteria               119
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                              ACKNOWLEDGMENTS


     This draft  guidance  document was prepared by Tetra  Tech,  Inc. for,the
U.S.  Environmental  Protection Agency  under the technical  support contract
for marine  discharge monitoring  evaluations,  U.S.  EPA Contract  No.  68->C8-
0001.   Nr.  Barry Burgan  was  the Work Assignment Manager.   Major technical
contributors  were  Dr.  Gordon  Bllyard,  Dr.  Richard  Harris,  Dr,.  William
Muellenhoff,  Mr. James  Pagenkopf,  and  Dr. A.  Mills  Soldate.    Ms.  Nancy
Musgrove  and  Ms.  Karen  Keeley  compiled  and  edited  preliminary  draft
materials.   Ms. Marcy  Brooks-McAullffe  edited the document  and  supervised
document production.
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                             EXECUTIVE SUMMARY
     Section  301(h)  of the  1977  Clean  Water  Act  (CUA)  allows  the  U.S.
Environmental  Protection  Agency  (U.S.  EPA)  to  Issue National  Pollutant
Discharge  Elimination System  (NPOES)  permits  to  publicly owned treatment
works  (POTWs)  for  the discharge  of less-than-secondary  treated effluent.
One of  the primary purposes of  this document  1s to Identify  changes to the
Section  301(h)  regulations  promulgated  by EPA to  Implement new Section
301(h)  conditions  Imposed by  the  Water  Quality Act  (WQA)  of 1987  and to
provide technical guidance for Implementing those changes.  Guidance Is also
provided on assessments and data  analyses  that applicants must  perform to
satisfy  regulatory requirements,  and  on  methods that  regulatory personnel
may use to evaluate  compliance with  those  regulatory requirements.   This
guidance 1s provided  1n three forms:

     •     Explanations  of  WQA  Sections   303(a) through  303(g),  and
           resulting  changes  In  the Section 301(h)  regulations   (I.e.,
           all citations to Part  125)

     •     Technical guidance for implementing  the  new regulations, and
           updated  technical guidance for  implementing regulations that
           have not changed

     •     Guidance on the preparation of applications for reissuance of
           Section  301(h)  modified NPOES permits, on  the  evaluation of
           those  applications to determine compliance  with the regula-
           tions,  and  on the issuance  and reissuance  of Section  301(h)
          modified permits.

     The  WQA  of  1987  amended  CWA Section 301 (h)  in  eight respects,  as
summarized below.  References to key affected subsections of the amended CWA
301(h) regulations, as renumbered,  are shown in brackets.

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1)   Section  301(h)   modified  discharges  are  prohibited  from
     Interfering,  alone or In  combination  with pollutants  from
     other  sources,  with the  attainment or maintenance  of water
     quality  which  assures  the protection  and  uses  listed  1n
     Section 301(h)(2).  (emphasis added) [125.62(f)]

2)   The  scope  of monitoring Investigations  Is limited to  only
     those  Investigations  necessary  to  study  the effects  of the
     modified discharge.  [12S.63(a)]

3)   With   respect   to  any  toxic   pollutant   introduced  by  an
     Industrial  source  and  for which  there  1s  no  applicable
     pretreatment requirement  in effect, POTVs serving populations
     of  50,000  or more  are required to  demonstrate  that sources
     Introducing  waste Into  the POTW are in  compliance  with all
     applicable  pretreatment  requirements,  that the  POTW  will
     enforce those requirements, and  that the POTW has 1n effect a
     pretreatment program which, 1n  combination with the POTW's own
     treatment  processes,   removes   the  same  amount  of  toxic
     pollutant  as would  be  removed if  the  POTW  were  to apply
     secondary treatment  and had no pretreatment program for that
     pollutant.      [125.65,   125.58(g),  125.58(j),   125.58(q),
     125.58(w), 125.58(b)]

4)   At  the  time  the  Section  301 (h)  modified permit  becomes
     effective,  the   POTW  must  be  discharging effluent  that has
     received  at  least  primary  or  equivalent  treatment  [as
     defined  in  Subsection  125.58(r)],  and  that  meets  the water
     quality criteria established under 304(a)(l) of the WQA after
     Initial mixing  In the receiving waters.  [125.60, 125.58(r),
     125.62(a)]

5)   Section  301(h)   modified  permits  nay  not  be  Issued  for
     discharges  into  waters  that contain significant  amounts of
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          previously discharged  effluent  from the POTW.   [Regulations
          not amended.]

     6)   Section  301(h)  modified  permits  may  not  be  Issued  for
          discharges Into saline estuarlne waters that exhibit stressed
          conditions,  regardless of  the  applicant's contribution  to
          those stressed  conditions.   Section 301(h)  modified permits
          may not be Issued for discharges into the New York Bight Apex
          under any conditions.  [125.59(b)(4), 125.62(f)]

     7)   Any POTW  that had  an  agreement before  31 December  1982  to
          use an outfall operated by another POTW which had applied for
          or  received  a Section  301(h)  modified  permit  could  have
          applied for  Its own  Section 301(h)  modified permit within 30
          days of enactment of the WQA.   [Regulations not amended.]

     8)   Some provisions of the WQA do not  apply to applications that
          received tentative or  final approval before enactment of the
          WQA,  but  apply to  all applications for renewal  of Section
          301(h) modified permits.  [125.59(e)]

     Among the  eight  major  changes listed above,  numbers  1,  3,  4, 5, and 8
are most Important to applicants and permittees that are not prohibited from
applying for a  Section  301(h)  modified permit under other provisions of the
amended regulations.  The first  major change requires POTWs to consider the
impacts  of  their discharge  on  the  receiving   environment  and  biota  in
combination  with  pollutants  from other  sources.   Previously,  POTWs  were
required  only  to consider  whether  their  discharge  contributed to  such
impacts.

     Change number 3 requires  applicants  to  implement an urban pretreatment
program.   This  new statutory  requirement  complements  the  toxics  control
program  requirements  in  Part  125.66,   and   applies  in  addition  to  any
applicable  pretreatment  requirements   contained   in   40   CFR  Part  403.
Dischargers may demonstrate compliance  with  Part 125.65  by demonstrating

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that an applicable pretreatment requirement is in effect, or by demonstrating
•secondary removal equivalency."

     Applicable  pretreatment requirements  may be  in  the form of categorical
pretreatment  standards promulgated by  the U.S.  EPA  under CWA  Section  307,
local limits  developed 1n accordance with  40 CFR  Part 403,  or a combination
of both.   It  Is  anticipated that most dischargers will be required to use a
combination of both approaches  to satisfy Part 125.65 with  respect  to all
toxic substances  Introduced  Into the treatment works  by Industrial sources.

     Alternatively,  a  discharger nay  demonstrate that  Its own  treatment
processes,  In  combination  with  pretreatment by Industrial  dischargers,
achieves  secondary removal  equivalency.   Dischargers are required  to  make
this  demonstration  whenever they  cannot   show  that  a  toxic  pollutant
Introduced  by   an  Industrial  discharger  1s  subject  to  an  "applicable
pretreatment  requirement."   Although  secondary   treatment  1s  Intended  to
control  conventional,  nontoxlc  pollutants,  a certain amount of each toxic
pollutant In  the  Influent 1s removed during  the process.  The Intent of this
part  of UQA  Section  303(c)  1s  to ensure  that a  Section  301(h) discharger
removes that  same amount  of a toxic substance through Industrial pretreatment
plus  the applicant's own treatment  at  less-than-secondary levels,  as would
be  removed  1f  the applicant  were  to apply  secondary  treatment   and  no
pretreatment  requirements existed  for  that  pollutant.   This demonstration
requires  the  use of  a  secondary treatment pilot  plant  to  determine em-
pirically  the amount  of  a  toxic pollutant  the  would be removed  from the
Influent  1f  the applicant  were  to  apply  secondary  treatment.  For  each
pollutant  Introduced  by  an  Industrial source,  that  applicant  would  then
demonstrate   that  Industrial  pretreatment  plus  the  POTW's own  treatment
processes  removed  the   same  amount  of  pollutant as was  removed   by the
secondary treatment pilot plant.

     Change number 4  requires  all Section  301(h) dischargers  to achieve a
minimum  of primary or  equivalent  treatment, thereby  establishing a primary
treatment  floor  for all  marine and estuarine POTHs.   It  also requires all
Section  301(h) dischargers  to meet the water  quality criteria established
                                    xiii

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under UQA  Section 304(a)(l) after  Initial  mixing in the receiving  waters.
                                                                    •
Section  301(h)  dischargers have  always been required  to  meet state  water
quality  standards that are appropriate to  local  conditions,  and  that have
been approved by  the  U.S.  EPA.   For this  reason,  Section 301 (h) dischargers
are required  first to demonstrate compliance with water quality  standards,
and then to  demonstrate compliance with  water  quality criteria only  for
those pollutants  for which no directly corresponding numerical  water quality
standard exists.  For example, 1f a water quality standard exists only for a
group of toxic substances, such as metals, applicants would also be required
to  demonstrate  compliance  with  the water  quality criteria for  Individual
metals  (e.g.,  cadmium,  lead,  zinc)  to  demonstrate  compliance   with Part
125.60.

     The Section  301(h)  regulations  were  not  amended  with  respect to change
number 5--rec1rculat1on  and reentralnment of previously discharged effluent
from the POTW.    However,  POTWs  that discharge Into  receiving  environments
where reentralnment  Is  likely must consider the possible effects  of such
entrapment  when  demonstrating  compliance  with  applicable  water  quality
standards,  water  quality  criteria,  and  other   Section  301(h)  criteria.
Reentralnment 1s  most often  of  concern  in  bays  and estuaries where tidal
currents predominate,  and  where  previously  discharged effluent  is likely to
be advected Into  the ZID after the tidal currents reverse.

     Change number 8  in  the regulations "grandfathers"   applicants that had
received  tentative  or  final  approval  of  their  Section  301(h)  modified
permits before passage of  the UQA.   Such  applicants are "grandfathered" for
changes  1, 3, 4,  and  5 above,  but only for the term of the existing Section
301(h)  modified  permit.    Applicants for  reissuance of  Section  301(h)
modified  permits  must demonstrate  compliance  with  all applicable  Section
301(h)  criteria  to  qualify  for renewal  of  the  Section  301(h)  modified
permit.   Moreover,  under Subpart 12S.59(e)  applicants for new or reissued
Section  301(h)   modifications  (Including  grandfathered applicants)  must,
within 90  days  of  the effective date  of the amended  Section  301 (h) regu-
lations, submit to  the Administrator additional Information regarding their
Intent to  demonstrate compliance with  Part  125.60 (I.e.,  primary treatment
                                    xiv

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floor,  compliance with  water quality  criteria)  and Section  125.65  (I.e.,
urban area  pretreatment  requirements).   Such applicants  will  then have 2 yr
to demonstrate compliance with  Parts  125.60 and 125.65, or  In the case of
some  grandfathered  applicants,  until  the time  of application  for  permit
renewal 1f  that time  1s more  than 2 yr  away.

     In addition,  definitions of primary or equivalent treatment, pretreat-
ment,  categorical  pretreatment  standard,  secondary  removal  equivalency,
water quality  criteria,  permittee,  and New  York  Bight Apex have  been added
to the amended  Section 301(h)  regulations, and definitions  of  Industrial
source, ocean  waters, applications,  and application questionnaire have been
changed.

     New technical guidance given 1n this  document primarily addresses major
changes numbers 1, 3,  4, and  5 above.   Hence, It  Includes the following:

     •    Guidance  for  assessing  Impacts of the applicant's modified
          discharge  "alone or 1n combination with pollutants from other
          sources"

     •    Guidance  on methods for demonstrating  compliance with  urban
          area pretreatment requirements

     •    Guidance  on methods for demonstrating compliance with appli-
          cable water quality standards and  criteria

     •    Guidance  for  demonstrating  that  dilution water does  not
          contain significant amounts of previously discharged effluent.

Updated guidance  that reflects technical   advances made since publication of
the  earlier version  of  this  guidance  document,  the  Revised Section  301(h)
Technical Support Document,  1s  also provided  for demonstrating  compliance
with existing  Section 301(h)  regulations.  Technical areas  that have been
updated most extensively Include the physical and water quality assessments
and the discussion of navigational requirements.
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     General guidance, new guidance,  and updated guidance are provided 1n the
format  of  the  Application  Questionnaire,  with  supporting  appendices  as
warranted.  General guidance Includes discussions of the types of demonstra-
tions  that  should  be  Included  by applicants  when  responding  to  each
question.  Detailed technical explanations of analytical methods that may be
used  to  demonstrate  compliance  with  specific  regulatory  criteria  are
provided  1n six supporting appendices.   Methods  for calculating  Initial
dilution of the wastefleld are provided 1n Appendix A (Physical Assessment).
Detailed descriptions  of analytical  methods used  to  demonstrate compliance
with water  quality regulations  are  presented  In Appendix B  (Water  Quality
Assessment).   These methods address suspended  solids deposition,  dissolved
oxygen concentrations,  sediment oxygen demand,  suspended  solids concentra-
tions, effluent  pH,  light  transmlttance,  and other water  quality variables.
Guidance  for biological assessments,  as  represented by  benthic  community
evaluations,  1s  presented  1n  Appendix  C.   Navigational  considerations for
sampling 1n  estuarlne and coastal areas are discussed In Appendix  D.   The
new  urban  area  pretreatment   requirements  and methods   for  demonstrating
compliance  with  them  are  described 1n  Appendix  E.   Finally,  additional
Information on water quality-based toxics control 1s presented in Appendix F.

     Because of  the  extensive  redundancy that  existed between the Small and
Large Applicant Questionnaires  In the 1982 regulations, a single Application
Questionnaire  Is Included  In  the amended Section  301(h)  Regulations.   It
combines relevant questions from the two earlier questionnaires and Includes
new questions  that address the changes 1n the  Section 301(h) regulations.
In addition  to  providing technical guidance for responding  to questions in
the Application  Questionnaire,  this  document Identifies who  must respond to
each question  (I.e., large  dischargers,  small  dischargers,  or both).   It
also discusses  the levels  of  detail  that are  appropriate for responses by
dischargers of different sizes and Into different receiving environments.

     Each application for a Section 301(h) modified NPDES permit is submitted
to, and  reviewed  by,  the  appropriate  U.S.  EPA Region.   Having  reached a
decision  regarding  an  application   for  reissuance  of   a  Section  301(h)
                                    xv 1

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modified permit, the  Region  nay reissue the Section 301(h) modified permit
with the  same  or different  permit conditions, or  deny the Section 301 (h)
modification.    In  the  case of  denial,  the  NPOES  permit would  then be
reissued by the U.S.  EPA  (or, In  NPDES-delegated  states, by the  state)  with
secondary treatment  requirements.   This  document defines the conditions
.under which each  of these actions  1s  appropriate,  and provides the Region
with guidance  on procedures for reissuing  and  terminating Section 301(h)
modified permits.   It does not  provide  guidance on  the  preparation  of  NPDES
permits, which  has been published elsewhere (U.S.  EPA  1986b).
                                     xvii

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                                INTRODUCTION
     Section  301(h)   of the  1977  Clean  Water  Act  (CWA)  allows the  U.S.
Environmental Protection  Agency (U.S. EPA) Administrator,  upon application
by publicly owned treatment works (POTWs) and with concurrence of the state,
to Issue National Pollutant Discharge Elimination System (NPDES) permits for
the discharge of less-than-secondary  treated  effluent.   POTWs were eligible
to apply for such modified permits  If they discharged to marine or estuarine
waters,  and  1f  they  could  demonstrate  compliance  with  Section  301(h)
criteria and all other NPDES permit requirements.

     Section  301(h)  was  amended  In  1981  by  the  Municipal  Wastewater
Treatment Construction  Grants  Amendments,  and the deadline  for submittal of
Section 301(h)  applications was  extended to  29 December 1982.  In 1982, the
Revised  Section 301(h)  Technical  Support Document  (Tetra  Tech  1982b)  was
Issued.  It identified the new regulatory requirements of Section 301(h) and
provided technical  guidance on  the preparation of  Section  301(h)  applica-
tions.   A  companion document,  Design  of 301(h)  Monitoring  Programs  for
Municipal Hastewater Discharges  to Marine Haters  (Tetra Tech  1982a),  was
also Issued in  1982.   It provided guidance on the development and implemen-
tation of monitoring programs that would meet Section 301(h) requirements.

     Section  301(h)  was  amended again  by the  Water  quality  Act  (WQA) of
1987.  That  act did not extend  the 1982  application deadline or reopen the
application process  to  POTWs  that  had  not  applied by the  1982 deadline.
However, it did  amend Section  301(h)  for POTWs already in the program.  One
of the primary  purposes of this  document  is to  identify  changes  to  the
Section  301(h)   regulations  promulgated  by  EPA to  implement  new  Section
301(h) conditions  imposed by  the  Water  Quality Act of  1987  and to provide
technical guidance  for implementing  those  changes.    This  document   also
provides guidance on  assessments  and  data  analyses  that   applicants   must
perform to  satisfy all  applicable regulatory requirements,  and  on  methods
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that regulatory personnel may  use  to evaluate compliance with  those  regu-
latory requirements.

     This  document supercedes  the  Revised Section  301(h)  Technical  Support
Document.   It  Incorporates relevant guidance from that earlier document and
from more  recent  guidance documents produced under the 301(h) program since
1982.    Design  of  301 (h)  Monitoring  Programs  for  Municipal  Vastewater
Discharges to Marine Haters  remains relevant to the 301(h) program, although
much additional technical guidance Is now  available  (see Question  III.F.I
under  the  section  entitled  "Appropriate  Analyses   and  Presentations  of
Results" below).  The more recent guidance documents provide state-of-the-art
guidance on the collection,  analysis,  and  Interpretation of monitoring data,
Including   references  for  the  most   up-to-date  laboratory  and  analytical
techniques.  This more recent guidance and the general guidance provided In
the  1982  document  provide  a  solid  technical   basis  for  the design  and
execution  of Section 301(h)  monitoring programs.

     This  Amended Section 301(h) Technical Support Document 1s divided Into
two major  sections: a  main  body of text and  appendices.   The main  body of
text reviews the regulations  Implementing  Section 301(h)  (I.e., Part 125
Subpart 6)  and  highlights proposed changes to those regulations made by EPA
to reflect the references to  Section  301 (h) made by  the 1987 WQA.  It also
provides  general   technical  guidance  to  dischargers  on the  preparation of
Section  301(h)   applications  for  permit  relssuance,   Including  general
discussions of  the types  of  demonstrations  that should  be  Included  by
applicants  when responding to each question In  the application  questionnaire.
For example, 1t specifies whether large or snail dischargers  should respond
to a given  question, and  discusses the level of detail  that 1s  appropriate to
each.   Methods  that   EPA  personnel   may use to evaluate  compliance with
regulatory criteria are  also  discussed.   The  appendices contain detailed
technical  explanations  of the analytical methods that may be  used to demon-
strate  compliance  with  specific  regulatory  criteria  (e.g.,  formulas  to
determine   dissolved   oxygen   concentration  following  Initial  dilution,
detailed  discussions of  methods to demonstrate  compliance  with urban area
pretreatment requirements).
                                      2

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     The  Section  301(h)  regulations  distinguish  between  large and  small
dischargers,  and that distinction  Is maintained throughout  this  document.
Dischargers are considered to be large or small based on their effluent flow
and  service  population.   Large dischargers are defined  as  POTWs that "have
contributing populations equal to or  moire  than 50,000 people or average dry
weather  flows  of  5.0  MGD  (million  gallons  per  day)  or  more."    Small
dischargers  "have contributing populations of less than 50,000  people and
average dry weather flows of less  than 5.0 MGD."   The definition In Subpart
125.58(c)  further  stipulates that estimates of "the contributing population
and  flows shall  be based  on  projections for the end of the five year permit
term.  Average dry weather flows  shall be  the average dally total discharge
flows for the maximum month of the dry weather season."

BACKGROUND

     Section  301(h) was  amended  by  UQA Section  303,  entitled "Discharges
Into Marine  Waters."  Section 303 Includes Sections  303(a)  through 303(g).
The  Section  301(h) regulations  have  been  changed  1n  response  to  these
statutory  amendments,  and  guidance  Is now   needed  to  Implement  the  new
regulations.    As  background  to  providing   such  guidance,  each  of  the
statutory amendments 1s summarized below, followed by a brief description of
the  corresponding  changes  in the Section 301(h) regulations.   Citations to
the  Part  125,  Subpart  G regulations that appear  in the  discussion below
refer to the section numbers of the regulations as renumbered.

     Section 303(a)  amends  Subsection 301(h)(2) to state that the modified
discharge "will  not interfere a7one or  in combination  with pollutants from
other sources,  with the  attainment  or  maintenance  of water  quality which
assures protection  of public water supplies  and the protection and propaga-
tion of a  balanced, Indigenous population of  shellfish,  fish and wildlife,
and  allows recreational  activities,  in and on  the  water" (emphasis added).
This  amendment  strengthens  the existing  regulations  to  prohibit  Section
301(h) discharges  into receiving waters where  pollutants from the discharge
would, in combination with pollutants from other  sources, result in adverse
impacts to  water  quality, recreational  activities,  or  the  resident  biota.

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In response to WQA Section 303(a), language was added to Subpart 125.-62(f)  to
clarify this  Issue.   The new language makes clear that 1t 1s not sufficient
to demonstrate  that the  applicant's  own discharge will  not  Interfere  with
the attainment or maintenance of water quality  as specified 1n the remainder
of Part 125.62.  Applicants must now demonstrate compliance with Part 125.62
based  on  the  combined effects  of the  applicant's  modified discharge  and
pollutants from other  sources.

     Under WQA  Section 303(b), the scope of  a Section  301(h)  discharger's
monitoring program Is limited to  "those scientific  Investigations  that are
necessary to  study the effects of the proposed discharge."  This limitation
1s applicable only to modifications and  renewals  of  modifications  that are
tentatively  or finally  approved  after  the date  of  enactment of  the  WQA.
Although  the existing  Section  301(h) requirements for  monitoring  programs
were already  generally focused  on the effects of the applicant's discharge,
this limitation was added to Part 125.63 of the regulations.  This limitation
does not  affect the precedent for developing monitoring programs on a case-
by-case basis.

     WQA  Section  303(c)  1s  applicable  only  to large dischargers  that
discharge  toxic  pollutants  Introduced  by industrial  sources.   It  mandates
that for  any toxic  pollutant introduced by  an Industrial  source for which
there  are no applicable  pretreatment  requirements  in effect,  the applicant
will  demonstrate  that  sources  introducing   waste  into  the  POTW are  in
compliance  with  all  applicable   pretreatment  requirements,  the applicant
will enforce  those  requirements,  and the  applicant will demonstrate that the
POTW has  in  effect a pretreatment program which, in  combination  with the
POTW's own treatment processes, removes  the  sane  amount of toxic pollutant
as would be removed  if the POTW were to  apply  secondary treatment and had no
pretreatment  program  for  the  pollutant.    This "secondary  equivalency"
requirement  places  a  technology-based  standard  on  the  discharge  of toxic
pollutants by applicable Section 301(h) dischargers.   Under this provision,
each such applicant  must  demonstrate, for each toxic  pollutant  introduced by
an  industrial discharger,  either  that  1t has  an  "applicable pretreatment
requirement  in  effect" or  that it has  implemented a program that achieves

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 "secondary  removal  equivalency."    Section 303(c)  also requires  POTWs to
 demonstrate  that Industrial  sources of toxic substances are  In compliance
 with  all  of their  pretreatment  requirements,  Including numerical standards
 set by local limits, and that those  standards will be enforced.
                                                                     *
     To  Implement  HQA  Section 303(c), Part  125.65 was  added to the regula-
 tions, definitions  were added to  Part 125.58, and  existing definitions In
 Part 125.58 were revised.   Part  125.65 requires that an urban area pretreat-
 ment  program be Implemented  by  applicable POTWs to demonstrate that  toxic
 pollutants are  being controlled.  It also provides options for  Implementing
 that program.   Definitions  that  are relevant to the urban area  pretreatment
 program  and that  have  been revised  or  added  to the  regulations Include
 "categorical pretreatment  standard," "Industrial  discharger" or  "Industrial
 source," "pretreatment," "secondary  removal equivalency," and "water quality
 criteria."

     HQA Section 303(d), establishes a minimum of primary treatment (or  Its
 equivalent).    "Primary  or equivalent  treatment"  Is defined  1n Subsection
 303(d)(2) as  "treatment by  screening,  sedimentation,  and skimming adequate
 to remove  at least  30  percent  of the  biological  oxygen demanding material
 and  of the  suspended  sol Ids  In the  treatment  works  Influent,  and disin-
 fection, where  appropriate."  This  subsection also mandates compliance with
 federal  water  quality criteria  (U.S. EPA  1980,  1985b,  1986a)  for Section
 301(h) dischargers.

     To  Implement  WQA Section  303(d), Part  125.60  requiring a minimum of
 primary  or  equivalent  treatment  was  added to  the  regulations,   and   the
 definition  of  "primary  or equivalent  treatment"  stated  In  the  WQA   was
 incorporated  into   the  Section  301(h)   regulations  without   change   [see
 Subpart  125.58(r)].  Subpart 125.62(a) of  the regulations  was  also amended
 to state  that  at and  beyond the boundary of the zone  of  initial  dilution
 (ZID), applicants must meet all  applicable water quality standards, and  all
water  quality  criteria  established  under  Subsection  304(a)(l)   of  the   WQA
where  no  directly  corresponding numerical  water  quality  standards exist.
Hence, after demonstrating compliance with water  quality standards [as  was

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required  under the  1982 Section 301(h) regulations], applicants need  only
demonstrate compliance  with  those water quality criteria  (If  any) for which
no directly corresponding water  quality  standards exist.

     Under WQA Section  303(e),  Section  301(h)  modified  permits may  not  be
Issued 'for discharges Into marine waters where the  dilution  water  contains
"significant  amounts of previously discharged  effluent from  such  treatment
works."    Re-entra1nment  of  previously  discharged  effluent  1s  often  a
potential  problem 1n  receiving waters  that  exhibit poor  flushing  charac-
teristics,  such  as  semi -enclosed  bays or  long,  narrow  estuaries.    This
section  also  prohibits  Issuance  of  Section  301 (h)  modified permits  for
discharges  Into  the New York Bight  Apex,  and for discharges  Into  saline
estuarlne waters  unless  those  waters meet all of the following conditions:

     •    Support a  balanced  Indigenous population  (BIP)  of shellfish,
          fish, and  wildlife

     •    Allow for  recreational  activities

     •    Exhibit ambient   water  quality  characteristics  that  are
          adequate to protect  public water supplies; protect shellfish,
          fish,  and  wildlife; allow  for recreational activities;  and
          comply  with standards that assure the protection  of such uses.

A  Section 301 (h) permit  may not be  issued  if any  one  of  the  foregoing
conditions does  not exist,  regardless  of  whether  the applicant's discharge
contributes  to  departures  from  or  retards  recovery  of  such  conditions.
Hence, WQA Section 303(e) prohibits Section 301(h) modified NPDES permits for
discharges into stressed saline  estuarine waters.

     Subpart  125.62(a)(l) of  the  1982  regulations  required the applicant's
diffuser to be located  and designed to  provide  initial dilution, dispersion,
and  transport sufficient to ensure compliance with  water quality standards
at and  beyond the ZID  boundary under  critical  environmental  and treatment
plant conditions.  Because Subpart 125.62(a)  was viewed  to be a sufficient

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criterion; for  ensuring that "significant amounts" of  previously discharged
effluent  are not entrained, this  subpart was  not modified In  response  to
UQA  Section  303(e).    [However,  guidance   Is  provided  herein  on  how  to
position  monitoring stations to  determine compliance with  this  provision  of
the WQA.]   Subpart  125.59(b)(4)  was modified to  Include  the prohibition  of
Section  301(h)  modified discharges  Into stressed saline  estuarlne  waters,
and Subpart  125.62(f) was modified to apply only to stressed ocean waters.

     WQA  Section  303(f)  applies  only to POTWs  that had existing agreements
(I.e., prior to 31  December 1982) to use outfalls of  Section 301(h) POTWs.
This  provision allows  those  POTWs  to  apply for  their own  Section 301(h)
modified  permit within 30 days  of enactment of  the WQA.    Because  no POTW
applied  under  this  provision,  the  Section  301(h)   regulations were  not
amended to reflect Section 303(f).

     As stated  1n WQA Section  303(g), Sections  303(a), (c),  (d), and (e)  do
not  apply  to   Section  301(h)  modified permits  that   were  tentatively  or
finally  approved prior to  enactment of the WQA.  However,  Section 303(g)
further  states  that  those  sections  will apply to all renewals of  Section
301(h) modified permits that postdate  enactment  of the WQA.   In response,
Subpart  l25.59(e)(l)(111)(D) was added  to the regulations, allowing  certain
applicants to  defer compliance with the specified section of the WQA until
permit renewal.   [Applicants that had been Issued tentative denials,  or that
had withdrawn  their Section 301(h)  applications  prior to enactment of the
WQA may not  take  advantage  of  this "grandfathering"  provision.]  A require-
ment  was  also  added to  Subpart  125.59(e)  stating   that  "grandfathered"
applicants and  permittees must,  within  90 days  of the  effective date of the
regulatory revisions,  submit  additional information regarding  their intent
to  demonstrate  compliance  with  the new  requirements under  Parts 125.60
(primary  or  equivalent  treatment  requirements)  and 125.65   (urban  area
pretreatment requirements) upon permit renewal.

     The  statutory  deadline for  Section 301(h)  applications  was 29 December
1982.   Neither the  WQA nor the amended Section  301(h)  regulations extend
that  deadline.   Hence,  the  aforementioned  statute   and  changes  to  the

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regulations  only apply  to  POTUs  presently In  the  301(n)  program,   POTVIs
presently  1n the program  Include  those that presently hold  Section  301(h)
modified permits, and those  awaiting a final decision from U.S. EPA.

PURPOSE AND  SCOPE

     The primary purpose  of this  document Is to provide  technical support
for  Implementing  the  Section  301(h)  regulations   that  were  amended  In
response to  WQA  Section 303.   It does so in the following ways:

     •     Explaining WQA  Sections  303(a) through 303(g),  and resulting
           changes 1n the Section 301(h) regulations (provided above, 1n
           the  section  entitled "Background,"  and below, 1n the section
           entitled "Statutory Criteria and Regulatory Requirements")

     •     Providing   technical  guidance  for   Implementing   the  new
           regulations,   and   updating   that   guidance   for   existing
           regulations   (provided  below,   in  the   chapter   entitled
           "Demonstrations  of Compliance by Permittees")

     •     Providing  guidance  on  the  preparation  of  applications  for
           relssuance of Section 301(h) modified NPDES permits (provided
           below,  In  the chapter entitled "Demonstrations of Compliance
           by Permittees"), on the evaluation  of those applications to
           determine  compliance  with  the  regulations,   and  on  the
           Issuance  and relssuance  of Section  301(h)  modified permits
           (provided  below,  in the  chapters  entitled  "Evaluations of
           Compliance  by U.S.  EPA"  and  "Relssuance  or Termination of
           Section 301(h) Modified Permits," respectively).

     This  document provides the  following new technical guidance on how the
results of studies and monitoring can  be used to demonstrate compliance with
the new regulations:

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     •    Guidance  for assessing Impacts  of the applicant's  modified
       •'  discharge "alone or in combination with pollutants from other
       '• •" sources"

     •    Guidance  on  methods  for demonstrating compliance  with urban
          area pretreatment requirements

     •  ; Guidance  on  demonstrating compliance  with  applicable  water
          quality standards and criteria

     •    Guidance  for  demonstrating   that  dilution  water  does  not
          contain significant amounts of previously discharged effluent.

This  guidance appears  In the  section entitled  "Appropriate Analyses  and
Presentation of Results"  below, and  1n  some cases,  the appendices.   Updated
guidance 1s also provided on the calculation of Initial dilution, navigation
and station positioning methods, analysis of water quality data,  assessments
of the long-term effects  of  301(h)  discharges,  sedimentation and dispersion
models, calculations  of  Initial  mixing relative to  conditions  at  the  ZID
boundary, and  the  degree of recirculatlon  in the presence  of contaminated
receiving waters.

     Monitoring data collected during the term  of  the  modified NPDES permit
are  submitted  to the  regional jurisdiction of the  U.S.  EPA (hereinafter
referred to as  Regions)  1n accordance with  permit  procedures.  The Regions
use  these  data to determine  continuing  compliance  with the  terms  and
conditions  of  the  permit, and with Section 301(h)  regulations.   Although
this document was not  written  to help  the  Regions  evaluate monitoring data
during the  terms of  the modified  permits,  much  of the  guidance  provided
below Is applicable to such evaluations.

     NPOES permits  are Issued  for 5-yr  periods.   At least 180 days prior to
expiration,  POTWs  holding Section  301(h)  modified  permits must  apply  for
reissuance  of  their NPDES permits.   At the  same  time,  they  may  apply  for
relssuance  of their  Section 301(h)  modification,  as  stipulated  in  Parts

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125.59, 122.21(d), and 124.3.  Because the deadline for original applications
for Section 301 (h) modified permits has expired, only applications upon which
there  has  not yet  been  a decision and  applications for  re Issuance  will  be
considered by the U.S. EPA In the future.

     According  to Subpart 125.59(c),  "applicants for  permit  renewal  shall
support continuation  of  the  modification by supplying  to EPA,  upon request,
the. results of studies  and monitoring  performed  during the life of  the
permit."   However,  neither this  subpart  nor  other  subparts  of  Part 125,
Subpart  G  [Criteria  for Modifying  the  Secondary Treatment Requirements
under. Section  301(h) of  the Clean Water  Act]  provide  specific  guidance on
how  the results  of studies  and monitoring  should be  used to  support  the
application for permit reissuance.

     In the 1982 Section  301(h)  regulations,  U.S. EPA recognized the limited
financial  resources of  most small applicants  and  the lower  potential  for
environmental  Impacts typically associated  with small  discharges.   Those
regulations provided  separate questionnaires  for large and small applicants,
with fewer  requirements  placed  on small applicants.  To avoid the excessive
duplication  that  existed  with  the  separate  questionnaires,  the  amended
Section  301(h)  regulations,  and  hence  this  document,  present a  single
questionnaire.  In this document, each question in the combined questionnaire
is followed by  a  statement as to who must  respond  (i.e., large dischargers,
small dischargers,  or both), and guidance on  how  to respond.

     As was true under the 1982  regulations,  the  level of detail expected of
small  applicants  in their responses is considerably less than that  required
of  large applicants  for  the  same question.   Because the  amended Section
301(h) regulations  do not provide  specific guidance on the required  level of
detail,  the Regions  have  considerable  discretion  regarding  the  level  of
detail necessary for  applicants  to  demonstrate continued compliance  with the
301(h) regulations.  This document addresses the levels  of detail  that the
Regions  may  require  of  small  and  large  applicants   during  the  permit
reissuance process.
                                     10

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     This  document  provides  the  Regions  with procedures  for  evaluating
compliance with Section 301(h) regulations.  Appropriate uses  of monitoring
data  to   evaluate  compliance  with   regulatory   criteria   are  discussed,
Including the use  of monitoring  data to evaluate  predictions  of conditions
that were  expected to occur during the term of the  Section  301(h)  modified
permit.   Guidance  Is also  provided  to the Regions  on how to  evaluate  the
presence  or  absence  of environmental  Impacts, and  whether those  Impacts
comply .with 301(h)  criteria.

     Having reached a decision regarding an application for  relssuance of a
Section 301(h) modified permit,  the Region may reissue the Section  301(h)
modified permit with the same or  different permit conditions,  or  deny the
Section 301(h) modification.  In the case  of  denial,  the  NPDES permit would
then  be  reissued  by  the U.S. EPA (or, in NPOES-delegated  states,  by  the
state) with  secondary  treatment  requirements.  This document  defines  the
conditions under which  each of these  actions Is  appropriate,  and  provides
the Region with guidance on procedures for reissuing and terminating Section
301(h) modified permits.  It does not provide  guidance on  the preparation of
NPDES permits, which has been published elsewhere (U.S. EPA 1986b).

STATUTORY CRITERIA AND REGULATORY REQUIREMENTS

     The WQA of 1987  amended CWA Section 301(h)  in eight  respects.   Each of
these 1s summarized below,  followed by references  to key  subsections of the
301(h) regulations that respond to the statutory criteria of the CWA.

     1)   Section  301(h)   modified  discharges are  prohibited  from
          Interfering,  alone  or  in combination with pollutants from
          other sources,  with  the  attainment  or  maintenance  of water
          quality  which  assures   the  protection  and  uses  listed  in
          Subsection 301(h)(2).   (emphasis added) [125.62(f)]

     2)   The scope  of monitoring Investigations   1s  limited  to only
          those Investigations necessary  to  study the effects  of  the
          modified discharge.   [125.63(a)]
                                    11

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3)   With  respect   to  any  toxic  pollutant   Introduced  by  an
     Industrial  source  and  for  which  there   Is  no  applicable
     pretreatment requirement 1n effect, POTWs serving populations
     of  50,000 or more  are required to  demonstrate  that sources
     Introducing waste Into the  POTVf are 1n compliance  with all
     applicable  pretreatment  requirements,  that the  POTVf  will
     enforce those requirements, and  that the POTU has 1n effect a
     pretreatment program which, In combination with the POTU's own
     treatment  processes,,  removes  the  same   amount   of  toxic
     pollutant  as  would  be  removed  If  the POTU  were  to  apply
     secondary treatment  and had no pretreatment program for that
     pollutant.      [125.65,   125.58(g),  125.58(j),   125.58(q),
     125.58(w), 125.58(b)]

4)   At  the  time  the  Section  301(h)  modified permit  becomes
     effective,  the POTU  must be  discharging  effluent  that has
     received  at   least  primary  or  equivalent  treatment  [as
     defined  1n  Subpart  125.58(r)],  and  that  meets  the  water
     quality criteria  established under 304(a)(l) of the UQA after
     Initial mixing  in the receiving waters.  [125.60,  125.58(r),
     125.62(a)]

5)   Section  301(h)   modified  permits  may  not  be  issued  for
     discharges  Into  waters  that  contain significant  amounts of
     previously discharged effluent  from the POTU.   [Regulations
     not amended.]

6)   Section  301(h)   modified  permits  may  not  be  issued  for
     discharges Into saline estuarlne waters that exhibit stressed
     conditions,  regardless  of  the  applicant's  contribution to
     those stressed  conditions.   Section  301(h) modified permits
     may not be Issued for discharges into the Mew York Bight Apex
     under any conditions.   [125.59(b)(4), 125.62(f)j
                                12

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     7)   Any POTU that had an agreement before 31 December 1982 to use
          an outfall  operated  by another POTU that had  applied  for or
          received a  Section 301(h)  modified  permit could have applied
          for Its own Section  301(h) modified permit  within  30 days of
          enactment of the WQA.  [Regulations not amended.]

     8)   Some provisions of the WQA do not  apply to applications that
          received tentative or  final  approval  before enactment of the
          WQA,  but  apply to  all applications  for renewal  of Section
          301(h) modified permits.  [125.59(e)]

     Among the  eight  major  changes  listed above,  numbers  1, 3,  4, 5, and 8
are most Important to applicants and permittees that are not prohibited from
applying for a  Section 301(h)  modified permit under other provisions of the
amended regulations.  The first  major  change  requires POTUs to consider the
Impacts of their discharge  on  the receiving  environment and biota In combi-
nation with pollutants from other sources.   Previously,  POTWs  were required
only to consider whether their discharge contributed to such Impacts.

     Change number 3  requires  applicants to  Implement an urban pretreatment
program  (discussed  In detail  below  under "Demonstrations of  Compliance by
Permittees" and In Appendix E).   This  new statutory requirement complements
the  toxics  control  program requirements  In  Part 125.66,  and  applies  In
addition to  any applicable pretreatment requirements contained In Subpart
403.   Dischargers may  demonstrate  compliance with  Part  125.65  by demon-
strating that  an applicable  pretreatment requirement  1s  In  effect,  or by
demonstrating secondary equivalency.

     Applicable pretreatment requirements may be  In the form of categorical
pretreatment standards promulgated  by  the U.S.  EPA under CWA Section 307,
local limits developed in  accordance with Subsection  403,  or  a combination
of both.  It 1s anticipated that most  dischargers will be required to use a
combination of  both  approaches  to satisfy  Part 125.65 with respect to all
toxic substances introduced Into the treatment works by industrial sources.
                                     13

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     Alternatively,  dischargers  nay  demonstrate that  Us  own  treatment
processes,  In  combination  with  pretreatment by  Industrial  dischargers,
achieves  "secondary  removal  equivalency."   Dischargers are  required  to  make
this  demonstration  whenever  they  cannot  show  that  a  toxic  pollutant
Introduced  by  an   Industrial  discharger  1s  subject  to  an  "applicable
pretreatment  requirement."   Although  secondary  treatment  1s Intended  to
control  conventional,  nontoxlc pollutants,  a  certain amount of each  toxic
pollutant 1n the Influent  Is removed during the process.   The Intent of this
part  of WQA Section 303(c) 1s to ensure that a Section 301(h)  discharger
removes that same amount of a toxic substance through Industrial pretreatment
plus  the applicant's own  treatment at  less-than-secondary  levels,  as  would
be  removed  if  the applicant  were  to apply secondary treatment  and  no
pretreatment  requirements existed  for  that pollutant.   This demonstration
requires  the  use of a  secondary treatment pilot plant  to  determine empir-
ically  the  amount  of  a  toxic  pollutant  the would be  removed  from  the
Influent  If the  applicant  were  to  apply  secondary  treatment.   For  each
pollutant  Introduced by   an  industrial  source,  that applicant would  then
demonstrate  that  Industrial  pretreatment   plus  the  POTW's own  treatment
processes  removed  the  same amount  of  pollutant  as  was  removed  by  the
secondary treatment  pilot  plant.

     Change number 4 requires  all  Section  301(h) dischargers  to  achieve a
minimum  of  primary  or equivalent treatment,  thereby  establishing  a primary
treatment floor for all  marine and estuarine POTWs.   It  also requires all
Section  301(h)  dischargers  to  meet the water quality criteria established
under WQA Subsection 304(a)(l)  after  Initial nixing in the receiving waters.
Section  301(h)  dischargers  have always been  required to meet state  water
quality  standards  that are  appropriate  to  local  conditions,  and  that have
been  approved by the U.S. EPA.    For this reason, Section 301 (h) dischargers
are  required  first  to demonstrate compliance  with  water quality standards,
and  then to  demonstrate  compliance  with  water  quality criteria  only for
those pollutants for which no directly corresponding numerical water quality
standard exists.   For example,  if a water quality standard exists only for a
group of toxic  substances, such as metals,  applicants would  also be required
to  demonstrate  compliance with  the  water  quality criteria for individual
                                     14

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metals   (e.g.,   cadmium,  lead,   zinc)   to  demonstrate  compliance   with
Part 125.60.

     The  Section  301(h) regulations  were  not amended  with  respect to  the
change number  5,  redrculatlon and re-entra1nment of  previously discharged
effluent  from  the  POTH.    However,  POTUs  that discharge  Into  receiving
environments  where  re-entra1nment is  likely  must  consider  the  possible
effects  of such entrapment  when  demonstrating compliance with applicable
water quality  standards, water quality  criteria,  and  other Section  301(h)
criteria.   Re-entra1nment Is  most often of  concern In bays and estuaries
where  tidal currents  predominate, and  previously  discharged   effluent  Is
likely  to  be   advected  Into  the ZID  after  the  tidal  currents  reverse.
Technical guidance Is provided herein  to assist applicants with demonstrating
compliance with this new requirement.

     Finally,   the   change   number 8  1n   the  regulations   "grandfathers"
applicants  that had received tentative or  final approval  of their Section
301(h) modified permits  before  passage of the WQA.   Such applicants  are
"grandfathered" for  changes  1,  3,  4,  and 5 above, but  only for  the term of
the existing Section  301(h)  modified  permit.   Applicants for  reissuance of
Section  301(h)  modified  permits  must  demonstrate  compliance  with  all
applicable  Section  301(h) criteria to  qualify  for  renewal  of  the Section
301(h) modified permit.   Moreover, under Subpart 125.59(e), applicants for
new  or  reissued  Section  301(h)  modifications  (Including   grandfathered
applicants) must, within 90 days of the effective date of the amended Section
301(h)  regulations,  submit  to  the  Administrator  additional  information
regarding  their Intent  to  demonstrate compliance with Part 125.60  (I.e.,
primary  treatment  floor, compliance  with  water quality criteria)  and  Part
125.65 (I.e.,  urban area pretreatment requirements).   Such applicants  will
then have  2 yr to  demonstrate  compliance  with  Parts 125.60 and 125.65, or
in the case of  some  grandfathered  applicants,  until  the time  of application
for permit renewal  if that time is more.than 2 yr away.

     Each  of these  eight major statutory  changes  has  been Integrated  Into
the amended Section 301(h) regulations, and must be  satisfied  by applicants
                                    15

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for relssuance  of Section  301(h)  permits.   Regulations applicable to  such
applications  Include NPDES  permit regulations  (Part  122)  and the  amended
Section  301(h)  regulations  (Part 125,  Subpart  G).    These  regulations,
Including  the changes  that resulted  from  the  HQA  are discussed below  in
detail.

Part 122.  U.S. EPA Administered Programs;  The national Pollutant Discharge
Elimination System

Subpart 122.21 (d).  Duty to Apply-

     Under the  subpart, POTWs with an exiting  NPDES permit must  submit  an
application for a new NPDES permit a minimum of  180 days before the existing
permit expires.   The applicant may ask  to  submit the  new application after
this due  date, and  the Region  may  grant such  a request.   The  Region may
extend the due date  up to the expiration date of the existing permit.  Upon
review of  an  application,  the Region  may determine that additional Informa-
tion 1s  needed to determine  compliance  with  301(h) regulations  and  permit
conditions.   Such Information may be  requested  at  anytime  (Including after
the application deadline has passed) in accordance with Subpart 122.41(h).

     It  1s strongly  recommended  that  POTWs submit their  applications for
relssuance of Section 301(h) modified permits as early as  possible,  and no
later than 180 days  prior to expiration  of the  existing permit.  This early
submittal  1s  particularly  Important  because  of  the need  to  establish
compliance  with  the  recent  statutory amendments  to   Section  301(h).    As
discussed  below,  early submittal gives the  Regions  time  to review applica-
tions for  completeness, and  to  request  any  Information needed  to complete
applications  before  existing  permits  expire.   An applicant must  submit a
completed application containing all  required information prior to expiration
of the existing permit, or at the time the application 1s due, whichever is
first.   Timely submittal of  a completed application is required to qualify
for the continuation described below.
                                     16

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Part 122.6  Continuation of Expiring Permits--

     A permittee  may have submitted  a  complete,  timely application  to  the
Region,  but  through  no fault  of the  permittee,  the  Region  may not  have
Issued a new permit with  an  effective  date on or before the  expiration of
the  previous  permit.    This  section  provides  that  1n those  cases,  the
previous permit will remain fully effective and enforceable, pursuant to the
Administrative Procedures Act.

Part 125. Suboart G

Part 125.56.  Scope and Purpose--

     Part  125,  Subpart  6  establishes  the  criteria by which  the U.S.  EPA
evaluates requests for Section 301(h) modified permits.  It  also establishes
special  permit conditions  that must be Included In  Section 301(h)  modified
permits.

Part 125.57.  Law Governing Issuance of Section 301(h) Modified Permit--

     All  applicants  for Section  301(h) modified  permits  must  demonstrate
satisfactorily to the U.S.  EPA that nine  requirements will be met  by the
modified discharge:

     1.   An applicant must demonstrate  that an applicable water quality
          standard exists for each pollutant for which the modification
          is requested.  Details  of this requirement are given In Part
          125.61.     Demonstrations  that   applicable  water   quality
          standards exist will be superfluous for reissuance of Section
          301(h)   modified  permits because   the original  Section 301(h)
          modified  permit  was  based,  in   part,  on successful  demon-
          strations that such standards  exist.  However,  as  specified in
          Part 125.61,  an  applicant must demonstrate that the  modified
          discharge will comply with applicable water quality standards.
          An applicant  must  also provide a  determination signed  by an
                                     17

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     authorized  state  or  Interstate  agency,  stating  that  the
     modified  discharge Mill  comply  with  state  law.   Both  the
     demonstration  of  compliance with  applicable water  quality
     standards  and  the  state's  determination  are  required  of
     applicants for relssuance of Section 301 (h)  modified permits.

2.   An  applicant must  demonstrate  that the modified  discharge,
     alone or  In combination with pollutants from other sources,
     will  not  Interfere with  the  attainment  or maintenance  of
     water quality that  assures the  protection  of public  water
     supplies;  assures   the  protection  and   propagation  of  a
     balanced   Indigenous   population  of  fish,   shellfish,  and
     wildlife;  and allows for recreational  activities.   Specific
     demonstrations  that must  be performed by  an applicant  are
     stated  in  Part 125.62.   All are required of applicants  for
     relssuance of Section 301 (h) modified permits.

3.   An  applicant must demonstrate  that  a monitoring  program has
     been established, and that  this monitoring program Is capable
     of  documenting the Impact  of  the  modified  discharge on  a
     representative  sample of aquatic biota.   The scope  of that
     monitoring  program should  only  include those investigations
     necessary  to study  the effects  of  the modified  discharge.
     General  requirements of  monitoring program  design  and spe-
     cific requirements  of the biological, water quality, and ef-
     fluent  monitoring  components  are specified  in  Part 125.63.
     Demonstrating  that an effective  monitoring  program has been
     established  will   be simple  for most  POTWs that  apply  for
     relssuance   of  Section  301(h)   modified   permits  because
     monitoring data will have been  collected over the life of the
     existing  permit.    However, the U.S.  EPA  may  require  an
     applicant  to demonstrate the effectiveness of an established
     monitoring  program when the quality  of the  data  is suspect,
     or when Incomplete  data have been submitted to the U.S. EPA.
                                18

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4.   An  applicant  must  demonstrate  that  the modified  discharge
     will not result 1n  additional requirements on  other point  or
     nonpolnt  sources  of  pollutants.    Part  125.64  requires  an
     applicant to provide a determination  signed  by an  authorized
  .   state or  Interstate agency  Indicating  whether the modified
     discharge will  result 1n  any such additional requirements.
     The foregoing  demonstration  and determination of  compliance
     are required of  applicants for relssuance of  Section  301(h)
     modified permits.

5.   An applicant must demonstrate that pretreatment  requirements
     for sources  that  Introduce wastes  Into the treatment  works
     will  be  enforced.    This  demonstration  Includes chemical
     analyses  of the  discharge   for  all  toxic  pollutants  and
     pesticides;  Identification of sources of toxic  pollutants and
     pesticides;   and  development of,   Implementation of,   and
     compliance with an  approved  Industrial  pretreatment program,
     as  specified  1n Part  125.65.   However, these  requirements
     are waived  for small  applicants that certify  that there are
     no  known  or  suspected  sources  of  toxic  pollutants  and
     pesticides,   and  who  document   the  certification with  an
     Industrial user survey  as described  by  Subsection 403.8(f).
     Because they  receive Influent  only from municipal sources,
     most  small   applicants  for  reissuance  of  Section   301(h)
     modified permits will be  required  to  provide only  an  updated
     certification that there are no  known or suspected  sources of
     toxic pollutants or pesticides.   Because  Industrial  sources
     of pollutants may have changed over the  term of  the original
     Section  301(h)  modified  permit,   both  large   and   small
     applicants  should  review updated  information  on  industrial
     sources  of   pollutants  before   performing  the required
     demonstration or certifying that there are no known industrial
     sources of toxic pollutants or pesticides.
                                19

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6.   An  applicant with  treatment works  serving  a population .of
     50,000  or more must  demonstrate that at  the time of  final
     permit approval, applicable pretreatraent requirements  will  be
     1n  effect  for  each  toxic  pollutant  introduced  Into  the
     treatment works  from Industrial  users.   Applicable pretreat-
     ment  requirements  are defined  1n detail   In  Subpart  125.65.
     In  Part  125.65,  It  1s  further  stated  that applicants  may
     alternatively  meet  the  requirements  of  this  section  with
     respect to  a particular  toxic pollutant pretreatment  program
     1n effect [125.65(c)]» or  by having 1n  effect a  program that
     achieves  secondary  removal  equivalency  for that  pollutant
     [125.65(d)].

7.   An  applicant must demonstrate that  a schedule of activities
     has been  established to eliminate  the  Introduction of  toxic
     substances  from  nonlndustrlal  sources  Into  the  treatment
     works.  Just as was required  In  the original  Section 301(h)
     application,   applicants   must   comply  with  the  specific
     requirements of  Part 125.65(d).   These  requirements are that
     a public  education program  be developed,  submitted with the
     application,   and   Implemented;   that  nonindustrial   source
     control programs  be developed and  implemented  in accordance
     with  schedules submitted with the  application;  and that the
     foregoing  program  may be  revised  by  the  U.S.  EPA before
     Issuance  or reissuance of  a Section 301(h)  modified  permit,
     or  during  the term  of  that permit.    However,   for  small
     applicants  certifying that  there are no  known  or suspected
     problems  related to  toxic  pollutants  or pesticides in the
     discharge,  only  a public education  program  1s required.  As
     was true  for original Section 301(h) applications, most small
     applicants  should be  able  to  provide  the  foregoing certi-
     fication.    However,  updated  information  on  water quality,
     sediment  quality,   and  biological  conditions   should  be
     reviewed  by the small  applicant  before certifying that  there
     are   no   known   or  suspected  water   quality,   sediment
                                20

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     accumulation, or biological problems that are related to  the
     discharge of toxic pollutants or pesticides.

8.   An  applicant roust  demonstrate  that  the modified discharge
     will not result 1n  new or  substantially  Increased  discharges
     of the  pollutant  for which a Section 301(h) modification 1s
     being requested above the  discharge  specified 1n the Section
     301(h)  modified  permit.   Details  of this  requirement  are
     given  1n  Part  125.67,  which  states  that  where pollutant
     discharges  are attributable,   1n  part,  to  combined   sewer
     overflows,  an applicant  must  minimize  such  overflows  and
     prevent  Increased  discharges of pollutants.   An applicant
     must  also  project effluent volumes  and  mass emission  rates
     for  pollutants  to  which  the  modification  applies.    These
     projections  must  be provided  1n  5-yr  Increments  for  the
     design  life  of  the  facility.   This  demonstration  applies to
     applicants for relssuance of Section 301(h)  modified  permits.

9.   An applicant must  demonstrate that the modified discharge will
     have  received  at  least  primary  or  equivalent treatment,  as
     required under Part  125.60.  An  applicant must also meet  the
     criteria  established  under  CWA   Subsection  304(a)(l)   in
     accordance with  Subpart  125.62(a).   Section 301(h) defines
     primary or  equivalent  treatment.  It also  prohibits Section
     301(h)  modified  discharges  into waters  that  contain  "sig-
     nificant amounts of  previously discharged effluent from such
     treatment works," and  Into saline  estuarine waters that at
     the time of  application do not support a balanced  Indigenous
     population of shellfish,  fish  and wildlife, or allow  recre-
     ation in  or on the  waters,  or  which  exhibit  ambient  water
     quality that does not meet specified standards.  EPA has  de-
     termined that a  "significant.amount of  previously discharge
     effluent" is that  amount which would  cause the discharge plume
     to violate water quality  beyond  the zone  of Initial dilution.
                               21

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Part 125.58.  Definitions—

     This  section  defines  terms  applicable  to  Subpart  G  regulations.
Definitions  of primary  or equivalent  treatment,  pretreatment,  categorical
pretreatment   standard,    secondary   removal   equivalency,  water   quality
criteria, permittee,  and New York Bight Apex have been added to the amended
Section  301(h)  regulations, and  definitions of  Industrial source,  ocean
waters, applications, and application questionnaire have been changed.

Part 125.59.  General -

     This section establishes general criteria and requirements that must be
met by  applicants for Section 301(h) modified permits.   Also specified are
several  regulatory options  that may  be exercised  by U.S.  EPA  during the
application  process.   As Indicated  below,  some of  the  general  regulations
are not  relevant to  applications for relssuance  of  Section  301(h)  modified
permits.

     According  to  Subpart  125.59(a),  an  application may  be  based  on  a
current,  Improved,   or   altered  discharge   Into  ocean  waters  or  saline
estuarine  waters.   This  requirement  remains relevant to  applications for
reissuance of Section 301(h) modified permits.

     No  Section 301(h)  modified permits  may be  issued for the following
discharges [see Part  125.59(b)]:

     •    Discharges  that would not assure compliance  with Part 122 and
          Part  125, Subpart  G

     •    Discharges  of  sewage sludge

     •    Discharges  that would not be  1n compliance with state, local,
          or other federal laws and Executive Orders  [Subpart 125.59(b)]
                                     22

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     •    Applicants that  have  not met at least primary or  equivalent
          treatment requirements (Part 125.60)

     •    Discharges entering saline estuarlne waters that  are stressed
          1n the manner set forth In Subpart 125.59(b)(4)

     •    Discharges that enter the New York Bight.

This  requirement  Is  relevant  to  applications  for  relssuance  of  Section
301(h) modified permits.

     Subpart  125.59(c)  specifies that  all  applications for  Section 301(h)
modified permits must contain a  signed,  completed  NPDES application; a com-
pleted  Application Questionnaire;  and  a certification of veracity.   This
provision  remains  valid for applications  for relssuance  of  Section 301(h)
modified permits.  Applicants for permit renewal  should support continuation
of  their  modification  with  results of studies  and monitoring  performed
during the life  of the  permit.   As was  the case for original Section 301 (h)
applications,  the  level  of  detail  required of  applicants responding  to
questions  in  the  Application  Questionnaire  will  vary   according  to  the
volume,  composition,   and  characteristics  of  the  discharge,   and  to  the
characteristics  of the receiving environment and  biota.   Applicants should
consult with  the  EPA  Region  for permit relssuance  well  in  advance of the
application deadline.   Timely consultation will ensure that each applicant
is  informed  of  the appropriate  level  of detail  required to complete the
Application  Questionnaire, and  will  ensure  that  all data necessary for
completing  the  questionnaire  have  been  collected  and  are  adequate  to
demonstrate compliance with 301(h) criteria and regulations.

     Revisions to  original  Section 301(h) applications that were submitted
under  the  1979  and 1982  application  deadlines   are  discussed   1n  Subpart
125.59(d).   Such revisions are not relevant  to applications for reissuance
of Section 301(h) modified permits.  As noted above, a discharger holding an
existing Section 301(h) modified permit must submit an application for a new
                                     23

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Section 301(h) modified  permit  at least 180 days  before the existing permit
expires.

     Deadlines  for  subnrittal  of applications  for  relssuance  of  Section
301(h) modified permits  are specified 1n Subpart 122.21(d) and are discussed
above.  The distribution of such applications 1s not  specified In Part 124 or
Part 125, Subpart  G.   However,  applicants should  adhere to the distribution
schedule required  for original  Section  301(h) applications, as Indicated 1n
Subpart  125.59(f)(l):   one  original and  one copy to  the  appropriate  U.S.
EPA Regional  Administrator,   and  one copy to  state  and  Interstate agencies
authorized to provide certification  or  concurrence 1n accordance with Parts
124.53-124.55.     Deadlines   for  applicants  desiring  to  submit  revised
applications  following the Issuance  of a tentative decision  are  stated In
Subpart 125.59(f)(2).

     Under  Subpart  125.59(e),   applicants  or permittees  are required  to
submit   additional   Information  regarding   their  Intent  to  demonstrate
compliance with Part 125.60 (Primary or  Equivalent Treatment) and Part 125.65
(Urban Area  Pretreatment Program) within 90 days of  the effective date of
the regulations.    Subpart 125.59(e)  specifies the  additional  Information
required, and the  conditions under  which  the submittal  of this Information
may be  delayed until  the  time  of permit  renewal.   Deadlines  for providing
additional  Information  to  demonstrate  compliance  with  Parts  125.60  and
125.65 are specified  in  Subpart  125.59(f)(3).

     A favorable  state  determination 1s  required  before the Region reviews
an application.    Under  Subpart  125.59(f)(4),  state  determinations are due
to the regions no more than 90 days  after an application  1s submitted to the
U.S.  EPA.   The Regions  may extend this 90-day deadline upon request by the
state.   However,  extensions  are not recommended  because they decrease the
amount of time remaining until   expiration of the existing modified permit,
and the  amount of  time available for an  applicant to  respond to concerns of
the state.    It  is strongly  recommended that  the applicant  ensure that it
obtains a timely determination  from  the state to  submit  to  the Region, so as
                                     24

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not to diminish an applicant's likelihood of being reissued a Section 301(h)
modified permit.

     Under  Subpart  125.59(g),   the  Regions  may  authorize  or request  an
applicant  or  permittee  to  submit  additional  data  after the application
deadline. Such  Information must  be submitted  within 1 yr of the date of the
authorization or request.

     Options that the Regions and states may exercise In granting or denying
a  Section  301(h)  modified permit  are  specified 1n Subpart  125.59(1).   All
remain  relevant to applications  for reIssuance of Section  301(h)  modified
permits.  For the Administrator to grant a Section 301(h) modified permit, an
applicant  must  have  demonstrated  compliance  with  Parts  125.59-125.68.
State certification (concurrence)  Is also required, with the state director
coslgnlng  the  Section 301(h)  modified  permit  If  an intent to  do  so  was
indicated in the written concurrence.   Section  301(h) modified  permits must
be  Issued  in accordance with  procedures in Part 124, and  must contain all
applicable terms and conditions  specified in  Parts  122 and 125.69.   Appeals
of  Section 301(h)  determinations may be made in  accordance with procedures
in  Part  124.    Under  Subpart  125.59(h),  the  Administrator  may  grant  a
tentative decision on a Section  301(h)  modified permit if the applicant can
demonstrate that the  modified  discharge will comply  with  the provisions of
Subpart 125 based on a schedule submitted by the applicant.

Part 125.68.   Special Conditions for Section 301(h) Modified Permits--

     Part  125.68  sets forth special conditions  that must be  Included in
Section 301(h) modified permits, in addition to those specified 1n Part 122.
All remain valid  for  reissued Section 301(h) modified permits. The special
conditions are as follows:

     •    That effluent limitations and.mass loadings assure compliance
          with 301(h) regulations
                                     25

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That  schedules of  compliance be  Included  for  the  required
Industrial  pretreatment  program   [Subpart  125.66(c)],  the
nonIndustrial  toxics  control  program [Subpart  125.66(d)],
and control of combined sewer overflows [Part 125.67]

That  the  proposed monitoring program  Include provisions for
monitoring  biota  [Subpart 125.63(b)],  water quality [Subpart
125.63(c)], and effluent  [Subparts  125.60(b) and 125.63(d)]

That  the  monitoring  data  be  reported  at  the  frequency
prescribed  In the approved monitoring  program.
                           26

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                 DEMONSTRATIONS OF COMPLIANCE  BY  PERMITTEES
     The recently  promulgated amendments to  Part  125, Subpart G  have been
Integrated Into the  Section  301(h)  application questionnaire,  which must be
completed and  Included  with  all  applications  for renewal  of Section 301(h)
modified  permits.    Explanations  of  the  demonstrations   to  be  made  by
applicants are given below following each question, and 1n the appendices to
this document, as appropriate.

     All applicants  for new  or reissued Section 301(h) modified permits are
required  to  demonstrate  compliance  with  the  new  regulatory  criteria.
However,  Part  125.59  establishes   special   procedures  and deadlines  for
demonstrating  compliance  with Part  125.60  (I.e.,  primary  treatment floor)
and  126.65  (I.e., urban  area pretreatment  requirements).   Compliance with
Subpart 125.62(a)(l)  (i.e.,  water quality criteria) is not  included in the
special procedures and deadlines established under Part 125.59.

     Under Subpart 125.59(e),  applicants  for  new or reissued Section 301(h)
modified permits  must submit  a  letter of intent to  demonstrate compliance
with Parts 125.60 and 125.65.  For compliance  with Part 125.60, the letter of
intent  must  include a  description  of  the  proposed treatment  system and a
project  plan  for  achieving  compliance  (including   a  schedule  for  data
collection;  dates  for  design  and  construction  of  necessary  facilities;
submittal  of  influent,  effluent, and receiving water  quality  data;  and any
other  information  necessary  for determining  compliance with  Part 125.60).
For  compliance with Part   126.65,  the  letter of Intent  must  Include  a
description of the approach  that will  be used to  achieve  compliance and a
project plan  for  achieving  compliance  (including  necessary data collection
activities, submittal of  additional  information,  and  the  development of any
appropriate  pretreatment  limits).     Applicants  that  submit  additional
information must  modify their NPDES form and  Application  Questionnaire as
needed  to ensure  that the information  in their application is complete and
                                     27

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correct,  must  obtain new  state  determinations  as  specified 1n  Subparts
125.61(b)(2)  and  125.64(b),  and  must provide  the certification  required
under Subpart 122.22(d).

     Subpart  125.59(f)  requires permittees and applicants  with tentative or
final approval  of Section 301(h) modifications to  submit a letter of Intent
that  contains  the  Information   required  under Subpart  125.59(e)(l).   This
letter must  be  submitted within 90 days  of the promulgation  of the amended
Section 301(h)  regulations.   Applicants that have not yet received tentative
approval  of  a  Section  301(h) modification  must  submit a letter  of Intent
within 90 days  of receipt of that tentative approval.  Applicants that are
not  "grandfathered"  under  Subpart  125.59(e)(l)(1ii)(D)  must  demonstrate
compliance with Parts 125.60 and  125.65  within 2  years of the promulgation
of the  amended  Section 301(h)  regulations.   Applicants grandfathered under
the   aforementioned   subsection  must  demonstrate  compliance  with  these
subsections at  the time of permit  renewal or within 2 years of the promulga-
tion of the amended Section 301(h) regulations, whichever is later.

APPLICATION FORMAT

     As specified In  Subpart  125.59(c),  a full, completed  application for a
Section  301(h)   modified permit  contains  a  certification  of  veracity;  a
signed,  completed NPDES  application  [Short  Form  A  or Standard Form  A in
accordance with Subparts 122.21(d) and 124.3];  and a completed Application
Questionnaire.    The  order  in  which these  parts  are  assembled   Is  not
specified  in  the  301(h) regulations,   but  many  applicants  for  original
Section 301(h)  modified permits  used  the  following sequence: '

     •    Cover  letter  to  U.S.  EPA with  the  certification  of  the
          application's  veracity  either  Included  In,  or  attached to,
          the letter  [many large  applicants Included the  cover letter
          and  certification  of  veracity in  the  introduction  to the
          Application Questionnaire  (i.e.,  Part  I)]
                                     28

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     •    The  signed,  completed  NPDES  application,  establishing  the
          requested permit conditions (e.g., effluent limitations)

     •    The completed Application Questionnaire.
   .>
Although the foregoing sequence of application parts 1s not mandatory, it 1s
recommended  because  It  facilitates  review by  the Region and  appropriate
state  agencies.    Accessory documents  that would  be  useful  to  the Region
during review of the  application  (e.g.,  data reports)  should  be appended to
the application.

     The Application  Questionnaire given  as Appendix A  of Part  125,  Sub-
part G 1s  designed to provide  the U.S. EPA with  all  Information necessary
to determine whether  an applicant meets the statutory  criteria  and regula-
tions  of Subpart G.   Guidance provided 1n  this document and 1n  Design of
301 (h) Horn taring Programs  for Municipal  Hastewater  Discharges  to Marine
Haters (Tetra Tech 1982a) complements the questionnaire.  Although applicants
are required to  respond to applicable questions,  the  Regions  may determine
the appropriate  level  of response to each  question for each applicant.  The
Region may also allow  an  applicant  to Incorporate  data  by reference to
previous submlttals.

     The appropriate  levels  of response to questions should be communicated
by the Regions  to  each applicant  through  timely  consultation,  which will
help permittees  submit the  appropriate  Information on  time.   Because of the
substantial  differences  among permittees  and  their  respective  receiving
environments,  applicants' responses  to a  given  question  are  expected to
range  from a single  sentence to  a  very detailed  analysis.   Close working
relationships,  particularly during  the end of  the  existing permit term,
will  ensure that all  data  necessary   for  completion of  the  Application
Questionnaire are available well  in advance of the  application deadline, and
that each  applicant  understands  the level  of  detail  appropriate  for each
response.   Such  discussions should result  in more concise  responses to the
questions,  and   should  help  avoid unnecessary  effort and  expense  by  the
applicant during the  application process.
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REQUIRED DATA

     Applicants "shall support continuation of the modification by supplying
to EPA, upon request, the results of studies and monitoring performed during
the  life  of the  permit" [Subpart  125.59(c)].   For many  dischargers,  data
collected during  these  studies and monitoring programs will  be  relevant to
many, or all, of the questions In the Application Questionnaires.  Additional
relevant data may be found In publications and technical reports produced by
other agencies,  Institutions,  and companies working 1n nearby areas  of the
receiving  environment.    Data  from such  surveys  could be  used to  better
define  environmental factors,   such  as  the critical  density  profile  for
Initial dilution  calculations  or biological  conditions  in  a reference area.
However,  for  some   applicants,  no new data  [I.e., data collected  after
Issuance of  the original Section 301(h) modified permit]  will  be available
to respond to some of the questions in the Application Questionnaire.

     Although it  1s  the  permittee's responsibility to submit the appropriate
Information,  it  is  critical  that  the  Regions work with permittees,  and
communicate to them any perceived information deficiencies  well in advance of
the  application  deadline.    Once  informed of information  deficiencies,
permittees must collect, analyze, and  interpret  the necessary  information for
incorporation Into the application  for permit reissuance.  Failure to supply
necessary  information  could result in  permit  denial, based  on  the grounds
that  a  complete  application was not  submitted.   After an  application has
been received, however,  the  Region  may determine that additional Information
1s  needed  to  determine  compliance   with  301(h)   regulations  and  permit
conditions.  Such information may be  requested at any time (including after
the  application  deadline has  passed)  in accordance with  Subparts 125.59(f)
and 122.41(h).

APPROPRIATE ANALYSES AND PRESENTATION OF RESULTS

     Guidance is  provided below  for the preparation of complete  applications
for Section 301(h) modified permits.  Special instructions  and exceptions for
                                    30

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small applicants are also provided.  The  sequence  below corresponds .to that
recommended  In  the preceding discussion  of application format.   Accessory
documents (e.g., data reports) should be appended to the application.

     Just as  original  Section  301(h)  applications were based  on the most
recent, appropriate, and technically correct data  available at  the time the
application was  prepared,  applications for renewed Section 301(h) modified
permits  should  consider  monitoring data  collected  over  the  term  of  the
existing  modified  permit,  as  required  under Subpart  125.59(c)(4).    When
monitoring  data and  other  Information  collected  over the  term  of  the
existing  permit  confirm that  all  values  of the  variables  used In a  given
calculation or demonstration have not changed and are not expected to  change
over the term of the new modified permit,  the applicant may  simply reproduce
the calculation or demonstration that was  given in the original  application.
However, in cases where the values of one  or more variables  have changed, or
where new monitoring data  are useful for supporting  a  given  demonstration,
those data should be Included  in  the required  response. All  demonstrations
of  compliance  with applicable  statutes and  regulations must  consider  the
effects of the discharge singly and  in combination with pollutants from other
sources, if any other sources exist [301(h)(2)  and Subparts  125.57(a)(2) and
125.62(f)].
                                     31

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I.  INTRODUCTION
             •*  '                                              .

     For clarity  and consistency,  1t Is recommended that the application be
assembled, in the  following  sequence:

     •    A cover letter signed by the responsible official for the POTW

     •   .The  statement of veracity  mandated  in  Subpart 125.59(c)(3),
          also  signed by the responsible official  for the POTVI

     •    A  table  of  contents  for  the  application,   Including  any
          appendices

     •    A 11st  of  figures for the  application

     •    A 11st  of  tables  for the application

     •    A  signed,   completed  NPOES  Application  Short  Form  A  or
          Standard Form A

     •    A completed Application Questionnaire

     •    Any  accessory documents (e.g., technical reports) considered
          necessary  for an  Independent  review of the application.

     Guidance  for  preparing a  complete  application  for  reissuance  of a
Section 301(h)  modified permit 1s provided below.  The sequence in which the
application parts are discussed corresponds  to that recommended above.

     Just  as  original  Section  301(h)  applications  were based on  the most
recent, appropriate,  and  technically correct data available at the time the
application  was  prepared,  applications  for  reissuance of  Section  301(h)
modified permits  should consider monitoring data collected over the term of
the existing modified permit as required  under  Subpart  125.59(c}(4).  When
monitoring  data  and  other  information collected  over  the  term  of the
                                     32

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existing permit  confirm that  all  values of the  variables  used In a  given
calculation or demonstration have not changed and are not expected  to  change
over the term of the new modified permit, the applicant may  simply  reproduce
the calculation or demonstration that was given In the original  application.
However, 1n cases where the values of one or more variables  have changed, or
where new monitoring  data  are useful for supporting  a given  demonstration,
those data should be Included 1n the required response.

     Under 301(h)(2) and Subparts 125.57(a)(2)  and 125.62(f),  all demonstra-
tions of compliance with applicable statutes  and  regulations must consider
the effects of the  discharge  singly  and  In  combination with pollutants from
other  sources,  if  any other  sources  exist.    When  demonstrating  such
compliance, the level of detail required of small applicants Is  considerably
less  than  that  required of  large  applicants for the  same  demonstration.
Applicants  should  consult  with  U.S.  EPA  personnel  before  submitting  an
application to determine the  level  of detail  that 1s appropriate  for their
discharge.   POTUs  that have been classified as  small dischargers, but that
no longer meet the conditions of the definition of small discharger [Subpart
125.58(c)]  or that are not expected to meet those conditions during the next
permit  term,  must  apply for  reissuance of  this  Section  301(h)  modified
permit as a large discharger.
                                    33

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JJ.  GEHERAL INFORMATION AND BASIC DATA REOUIREHENTS

     II.A.  Treatment System Description

          II.A.I.   Are you applying  for a modification based on a  current
          discharge,  Improved  discharge,  or altered discharge as defined  in
          Part 125.58?  [Subpart 125.59(a)J

*** Large and small dischargers must respond.

     Applicants  should  consider  "current  discharge"  to  mean  the  actual
volume, composition,  and  location of a 301(h) permittee's discharge  at the
time of permit reappHcation.  Use of the latest 12 no of data would  be most
appropriate 1n the application.

     An "Improved discharge" may result from any of the following  changes:

     •    Improvements  to the  collection system,  treatment plant,  or
          outfall (Including outfall relocations)

     •    Improvements to treatment levels or discharge characteristics

     •    Improvements in the operation or maintenance of the treatment
          system

     •    Measures  to control  the  Introduction  of  pollutants  into  the
          treatment works.

For improved  discharges,  applicants  should  briefly describe the  changes  to
the treatment system  or Us operation upon which the application is  based.

     Discharge  alterations  include  all  changes  that  result in a  treatment
level  less than that currently achieved,  including changes in effluent volume
or  composition.    All changes  that  result  in  the downgrading of  effluent
                                     34

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characteristics,  regardless  of whether the outfall  was  previously -Improved
or  relocated  to  compensate  for  lower  effluent  quality,  are  considered
altered  discharges.    Applications  for altered  discharges are  permissible
only  for  downgrading  of effluent  characteristics  that  are  attributable
entirely  to population growth and/or Industrial growth within  the service
area.  Applicants  who propose  altered discharges based on  population growth
and/or Industrial growth, and who propose Improvements in treatments levels,
should briefly describe the changes to the treatment system or Its operation
upon which the application 1s based..

          II.A.2.   Description  of  the  Treatment/Outfall  System [Subparts
          125.62(a) and 125.62(e)]

               a.   Provide  detailed descriptions  and  diagrams  of  the
                    treatment  system  and outfall  configuration  which  you
                    propose  to satisfy the  requirements of Section 301(h)
                    and Part 125 Subpart  G.   Hhat is  the  total discharge
                    design flow upon which this application is based?

               b.   Provide  a  map  showing the  geographic  location  of  the
                    proposed  outfall(s)   (i.e.,  discharge).   What  is  the
                    latitude and longitude of the proposed outfall(s)?

               c.   For  a  modification   based  on  an  improved   or altered
                    discharge,  provide a  description and  diagram  of your
                    current  treatment  system  and  outfall  configuration.
                    Include the current outfall's latitude and longitude, if
                    different from the proposed outfall.

*** Large and small dischargers must respond.

     Most of the  above  Information  can  be  found  In  Sections 1-13  of  the
NPDES Standard  Form  A.   Past  experience In the  301 (h) program  has shown
that applicants often neglect  to describe the treatment and  outfall system
in sufficient detail  to allow evaluation of the technical merit of the appli-
                                     35

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cation.   Applicants  should" provide a  detailed  description of this  system
such that the reader will have a complete picture of the physical  aspects of
the treatment and outfall system and will be able to understand the treatment
processes that  occur therein.  Information  on dlffuser dimensions  that are
used  to  determine  the port  flow  distribution  achieved by the outfall  are
especially Important  (see Question  II.A.7 below), and should be specified as
accurately  as possible.    Figures  and  drawings with  dimensions should be
Included  1f possible.   In those descriptions,  applicants  should emphasize
any changes  In the  service area,  treatment  system, or outfall  system that
were  Implemented  during the term of the existing  permit.   Water depths and
navigational  coordinates  of the outfalls as  they  exist should be correctly
specified.   Water  depth  of  the  outfall should be  specified as the water
depth at  the  midpoint of the dlffuser, referenced  to mean sea level or mean
lower  low  water.    Water depths   and  navigational   coordinates  found  in
engineering design  documents  are often  not  correct because of changes in the
lengths  and  routes  of  the  outfalls   made  during construction.    Hence,
drawings  of as-built  conditions should  be used.

          II.A.3.     Primary  or  equivalent  treatment  requirements  [Part
          125.60]

               a.   Provide data  to demonstrate that your effluent meets at
                     least  primary  or  equivalent  treatment  requirements as
                    defined in Subpart  125.58 (r)?  [Part 125.60]

               b.   If your  effluent  does  not  meet primary  or equivalent
                     treatment requirements, when do you plan to meet them?
                    Provide a detailed schedule, including design, construc-
                    t/on,  start up, and full  operation, with your appli-
                    cation.   This  requirement must be met  by the effective
                    date  of the new section 30I(h) modified permit.
                                     36

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    Large and small dischargers must respond.

     Applicants must  demonstrate that  the  treatment works Mill  discharge,
at a minimum, primary treated effluent (or Its equivalent) at the time their
modification  becomes  effective,  as mandated  by  Parts  125.57 and  125.60.
Applicants are advised that  "primary or equivalent treatment"  1s  defined in
Subpart  125.58(r)  as  "treatment  by screening,  sedimentation,  and skimming
adequate to  remove at least  30 percent of  the  biological  oxygen demanding
material and  of the suspended  solids  1n the  treatment  works  Influent, and
disinfection,  where  appropriate."    To support   this  demonstration,  the
applicant should  supply  monthly averaged data (typically monthly averages)
for Influent BOD, effluent 6005, suspended sol Ids,  pH, and flow for the last
1-yr  period.    The form  of  such  data  (e.g.,  weekly averages,  monthly
averages)  should  be  specified  precisely  for  each  variable.    Applicants
should also submit  data  on the  predicted maximum 2- to 3-h flow for the new
end-of-permit year, and on measured effluent col 1form bacteria concentrations
1n a  form that  satisfies  state water quality regulations.   Where  average
values are given (e.g., average dry-weather flow),  applicants should specify
how they were calculated.

          II.A.4.    Effluent   Limitations   and  Characteristics  [Subparts
          125.61(b) and 125.62(e)(2)]

               a.   Identify  the   final   effluent  limitations  for  5-day
                    biochemical oxygen  demand (BODg),  suspended solids, and
                    pH upon  which  your application  for a modification is
                    based:

                    -  BOD$	mg/L
                    -  Suspended solids	mg/L
                    -  pH	 (range)
                                     37

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b.   Provide  data  on the following effluent  characteristics
     for your current discharge as well as for  the  modified
     discharge if different from the current discharge:

Flow (a? /sec):

     -  mini mm
     -  average dry weather
     -  average wet weather
     -  maximum
     -  annual average
     (mg/L) for the following plant flows:

     -  minimum
     -  average dry weather
     -  average wet weather
     -  maximum
     -  annual average
Suspended solids (mg/L) for the following plant flows:

     -  minimum
     -  average dry weather
     -  average wet weather
     -  maximum
     -  annual average

Toxic pollutants and pesticides (ug/L):

     -  list each identified toxic pollutant and
        pesticide
                      38

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               pH:

                    -  minimum
                    -  maxima

               Dissolved  oxygen  (ng/L,  prior  to  chlorination)   for  the
               following plant flows:

                    -  minimum
                    -  average dry weather
                    -  average wet weather
                    -  maximum
                    -  annual average

               Immediate dissolved oxygen demand (mg/L)

*** Large and small dischargers must respond.

     Applicants should specify  the  effluent limitations  requested  for their
Section  301(h) modified   permits,  and  the  basis  (e.g.,  monthly  average
values)  for those  limits.   Applicants  must  request  specific  limitations.
Except for pH, ranges of values or a list of alternatives are not acceptable.
The remaining  Information  on effluent characteristics can usually be found
by analyzing plant operating records.

          II.A.5.    Effluent  Volume  and Mass Emissions [Subpart  125.62(e)(2)
          and Part 125.67]

               a.    Provide  detailed  analyses   showing   projections   of
                    effluent  volume   (annual   average,  m*/sec)   and  mass
                    loadings (mt/yr)  of BODg and  suspended solids  for the
                    design life of your  treatment  facility in 5 year incre-
                    ments.   If  the  application  is  based  upon an improved or
                    altered discharge, the projections must be provided with
                    and without the proposed improvements or alterations.
                                     39

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               b.   Provide  projections for  the  end of your 5 year permit
                    tent  for   1)   the  treatment   facility   contributing
                    population  and  2)  the  average  dally total  discharge
                    flow for the maximum month of the dry weather season.

    Large and small dischargers oust respond.

     Applicants  should  project  effluent flows and  mass emissions  for  the
term  of the modified permit being  requested,  and for  subsequent  years at
5-yr  Intervals.    Projections should  be based  on annual  average  flows  and
annual average effluent characteristics.  Projections should reflect expected
changes  In  the  service area and  population  over the term of  the modified
permit  being  requested,  and over  the  subsequent  periods of time  being
considered.    Projections for  the new  end-of-permit year  must be  given,
including the  average dally flow  for the maximum month of the dry-weather
season, and average effluent characteristics for that month.

          11.A.6.    Average Dally  Industrial  Flow  (a?/sec).   Provide or
          estimate the  average  dally  Industrial  Inflow to your  treatment
          facility for  the same  time  Increments  as  in Question  II.A.5
          above.   [Part  125.66]

*** Large and small dischargers must respond.

     Annual average  flow  data will  generally  be  sufficient for nonseasonal
(I.e.,  continuous  operation) industries.   For  seasonal  industries, average
daily  flows  for the  periods of operation should be  provided.   Supporting
information  (e.g., lists of industries and  products manufactured)  may be
required.
                                     40

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          II.A.7.  Combined Sewer Overflows [Subpart 12S.67(b)]

               a.   Does   (will)   your  collection  and  treatment   system
                    Include combined sewer overflows?

               b.   If yes, provide a description of your plan for minimizing
                    combined sewer overflows to the receiving water.

*** Large and small dischargers must respond.

     Locations,  flow  quantities,   and  frequency  of  overflows  should  be
specified.  Data on total effluent flow and on effluent suspended solids and
BODs concentrations should be provided for  times when  overflows  occur.   The
effect of Increased Infiltration during the  rainy season should be discussed.
Applicants should  also provide a  narrative description and schedule  of  a
plan  for minimizing   the  discharge  of  combined   sewer  overflows  to  the
receiving water.

          II.A.8.  Outfall/Diffuser Design.  Provide the following data for
          your current discharge as well as for the modified discharge,  if
          different from the current discharge:  [Subpart  125.62(a)(l)]

                    Diameter and length of the outfall(s)  (meters)
                    Diameter and length of the diffuser(s)  (meters)
                    Angle(s)  of  port  orientatlon(s)   from  horizontal
                    (degrees)
                    Port diameter(s) (meters)
                    Orifice contraction coefficient(s), if known
                    Vertical distance from mean lower low  water (or mean low
                    water) surface and outfall port(s)  centerline (meters)
                    Number of ports
                    Port spacing (meters)
                    Design flow rate for each port,  if multiple  ports are
                    used (op/sec)
                                    41

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    Large and snail dischargers oust respond.

     The information requested above should be available from the engineering
drawings for the treatment plant outfall and diffuser system.  If risers are
used,  information  sufficient to  compute  the  riser discharge  coefficient
using the method of Koh  (1973) should also be provided.   For example,  if the
riser consists of a vertical  pipe the following details should be specified:
length and  Inside diameter of the pipe, material  from which It is made, and
diameter of the port orifice.  Missing  information should be so Indicated in
the responses  to the  foregoing  questions.   Because outfalls  and diffusers
are  often  built somewhat  differently  than  specified  In  the  engineering
design drawings, applicants are advised to provide as-built information.

     In  addition to  the foregoing  Information,  applicants should  provide
information on  the  slope of  the diffuser  and the slope  of the port center-
lines  if they  differ from  that of  the diffuser.   If the diffuser  ports
discharge  to  opposite  sides of  the diffuser, that  Information  should  be
noted.   The depths  of  the  ports  below mean  lower  low water  (or mean low
water  as  applicable) should  be  provided,  as  should any  variations  in port
depths along the length  of the diffuser.

     The  information  provided  In  this section  1s  routinely  used in the
review process  to determine whether the diffuser 1s  well-designed hydrauli-
cally for the range of flow  (dally minimum  to daily maximum) expected during
the requested  permit  term.   Among  the characteristics of  a  well-designed
diffuser  are  uniform port   flows  and  Individual  port densimetric  Froude
numbers that are always  greater than 1.  Methods  for computing the port flow
distribution from a multiport  diffuser are  described  by Grace  (1978) and
Fischer et  al. (1979).   Discharge coefficients  for risers  can be computed
using  methods  provided  by Koh  (1973).   [The explanation of  these methods
provided by Fischer et al. (1979) should not be used because  it 1s  incomplete
and contains  errors.]   The  effect of the  bottom slope must be included in
the diffuser hydraulics  computations because some diffusers behave properly
on a horizontal  seafloor, but poorly on a sloping bottom, especially at low
flow rates.
                                     42

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     II.B.  Receiving Water Description

          II.B.I.  Are you  applying  for a  modification based on a discharge
          to the  ocean  [Subpart 125.58(n)J or to a  saline  estuary [Subpart
          125.58(v)]?  [Subpart 125.59{a)J

    Large and small dischargers oust respond.

     "Ocean  waters"   are  defined  In  Subpart  125.58(n)  as coastal  waters
landward  of the  baseline  of the territorial  seas,  the deep waters  of the
territorial  seas,  or the waters  of  the contiguous  zone.   Territorial seas
extend  3  ml outward  from the  baseline  and  the contiguous  zone  extends an
additional 9 ml.  This term does not Include saline estuarine waters.

     "Saline estuarine  waters"  are  defined 1n  Subpart 125.58(v)  as semi-
enclosed coastal  waters that  have a  free connection to the territorial sea,
undergo  net  seaward  exchange  with  ocean  waters,  and  have  salinities
comparable  to  those  of  the  ocean.   Generally, these waters are  near the
mouth of  estuaries and have cross-sectional,  annual  mean salinities greater
than 25 ppt.   It  should  be noted, however, that 25 ppt 1s used as a general
test 1n Subpart 125.58(v).   The failure of the receiving water to meet this
salinity  concentration   does  not  absolutely  preclude   eligibility  for
consideration  under  Section  301(h).     However,   where  salinities  fall
substantially  below   this  concentration,  applicants  should  be  careful  to
document that  the waters Into which they  discharge  meet the other require-
ments of Subpart  125.58(v) (I.e., free connection to the territorial sea and
net seaward exchange with ocean waters).

     Estuarine dischargers  are  advised that  according to Subparts 125.57(a)
(9) and 125.59(b)(4), Section 301(h) modified  permits may not be Issued for
discharges Into saline estuarine  waters  unless those waters meet all of the
following conditions:
                                     43

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     •    Support  a  balanced Indigenous population  of shellfish,  fish,
          and wildlife

     •    Allow for  recreational activities in and on the waters

     •    Exhibit  ambient  water quality below applicable water quality
          standards  adopted for  the protection  of public water  sup-
          plies, shellfish, fish and wildlife or recreational activities
          or  such  other  standards necessary  to  assure support  and
          protection of such uses.

These  conditions  must be  met, regardless  of whether the  applicant's  dis-
charge  contributes  to  departures  from  such  conditions.    According  to
Section 301(h)(3)  and  Subpart 125.57(e), the foregoing prohibition does not
apply  to  discharges with  Section  301(h) modified permits that were  tenta-
tively or finally approved prior to the enactment  of the Water Quality Act
of 1987.   However,  1t  1s further stated that the foregoing prohibitions are
in force  for all  renewals  of  Section  301(h)  modified permits that postdate
enactment of the Water Quality Act  of 1987.   Thus, all estuarine dischargers
must demonstrate that the  receiving waters exhibit the above characteristics
(I.e.,  that  they  are not stressed)  at the  tine  of  permit  re issuance,
regardless  of whether  such  conditions  existed  at  the  tine the existing
Section 301(h) modified permit was  issued.

          II.B.2.    Is  your  current  discharge  or  modified discharge  to
          stressed  waters  as  defined  in Subpart 125.58(z)?  If  yes,  what
          are  the pollution sources contributing to the stress?  [Subparts
          125.59(b)(4) and 125.62(f)J

*** Large and small  dischargers must respond.

     "Stressed  waters"  are defined  In Subpart 125.58(z)  as  those  ocean
waters in which the  absence of a balanced indigenous population of  shellfish,
fish,  and wildlife  is caused  solely by human  perturbations  other than the
applicant's  modified discharge.    If the discharge is  to  stressed waters,
                                     44

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Subpart  125.57(a)  prohibits permit relssuance 1f the  discharge  alone  or in
combination  with  pollutants  from  other  sources  adversely  Impacts  the
balanced  Indigenous  population,  water quality,  or  recreational  activities.
In  addition, estuarine  dischargers are advised that under Section 301(h)(9)
and Subparts 125.57(a)(2)  and  125.59(b)(4),  permits may not  be reissued for
discharges to stressed saline estuarine waters.

     Applicants  that  respond "no" to  this  question should  state  the  basis
for their conclusion.

          17.0.3.  Provide a description and  data  on  the seasonal circula-
          tion patterns  In the vicinity  of your current and modified dis-
          charge(s).  [Subpart 125.62(a)]

*** Large and small dischargers must respond.

     The  applicant should  provide sufficient Information on current  speed
and direction 1n the vicinity of the discharge to predict the dispersion and
transport of diluted effluent.  This  Information  should Include a description
of  current  patterns  and general  density  structure on  a  seasonal  basis, as
well  as  the variation  over a tidal cycle.    Estimates of  near-surface and
near-bottom lowest 10 percentile  current  speeds  should be provided, as well
as  the  locations of the  current  meters  and  the time  span  over which data
were  collected.    Hydraulic  residence times  and  flushing  characteristics
should be  described  for discharges  Into  estuaries  and semi-enclosed bodies
of water.  Any periods  of net  drift stagnation and natural  upwelUng should
be described, Including changes in the current patterns and stratification.

     The  applicant should  also  discuss  the  occurrence of  onshore surface
currents.   Because onshore winds Induce onshore currents,  wind  speed and
direction statistics  that are appropriate for the  diffuser  location should
also  be  provided.   Useful  sources  of.  Information Include  data  collected
during execution of the monitoring program for the existing modified permit,
data collected  in the vicinity of the discharge by  other  researchers, and
                                     45

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U.S. Department of Commerce  tidal current tables (e.g., Tidal Current Tables
1988, Atlantic Coast of  North  America; Tidal Current Tables  1988,  Pacific
Coast of North America  and Asia).

     Subpart  125.57(a)(9)  prohibits  Section 301(h)  modified permits  for
discharges  where  the  dilution  water contains  "significant  amounts  of
previously discharged effluent  from  such treatment works."  In responding to
Question II.B.3,  applicants should discuss the potential for re-entra1nment
of  previously discharged  effluent.   Re-entrainment Is  a  potential  problem
primarily  In  receiving waters  that exhibit  poor  flushing characteristics.
Such  conditions  can also   occur,  however,  In  open  coastal  areas  during
periods of tidal  or wind-driven  current  reversals,  or temporary stagnation
of longshore  coastal currents.

          77.0.4.   Oceanographic conditions  in  the  vicinity of  the current
          and proposed  modified discharge(s).  Provide data  on the  fol-
           lowing:  [Subpart  125.62(a)]

                     Lowest  ten  percent He current speed  (a/sec)
                     Predominant current speed (m/sec) and direction (true)
                     during  the  four  seasons
                     Perlod(s) of  maximum stratification  (months)
                     Period(s)   of natural  upvelling  events  (duration  and
                     frequency,  months)
                     Density profiles during  pericd(s) of maximum stratifi-
                     cation

*** Only large dischargers  must respond.

     The vertical  and  areal  distribution  of currents and  water density in
both  the  near  field and far  field  are needed  to  evaluate plume dilution,
wastefield transport,  and potential  re-entrainnent of previously discharged
effluent.  Data collected from  previous studies  or nearby similar areas will
often be appropriate.
                                     46

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     The number  and location  of  sampling stations  needed  to provide  suf-
ficient data  will depend on  the  bathymetric and hydrograpMc environment.
For  open  coastal  sites  with  uniform  bathymetry   and  minimal   freshwater
Inflows, as few  as  five stations  may be  adequate.   However,  for  an  estuary
with significant  freshwater Inflow and highly variable bathymetry,  as  many
as 50 stations may be necessary.

     For existing discharges,  the measurements should be made In the vicinity
of the outfall but  outside  the region directly  Influenced by the  discharge.
For relocated outfalls, measurements  should be made In the  vicinity of the
proposed discharge  location.   Current  data should be obtained near  the
surface, at the  approximate depth  of the wastefleld, and In  the  bottom 2 m
(6.6  ft)  of  the water  column.   Water  depths  at   the  stations   should  be
similar to the water depth at the site of  the existing and relocated outfalls
(if present).

     The duration of time within which these measurements should be obtained
1s  dependent  on  the  current  regime  and  the  variability  of the  density
structure.   If the currents are predominantly tidal   (which  could be the case
for both open coastal and estuary  sites), the current measurements should be
at approximately  30-min  Intervals  for not  less than 29 days.  If seasonal
changes in oceanographic conditions (e.g., low or variable  longshore current
speeds or  directions,  upwelUng,  shoreward transport, high  and low  runoff)
are significant,  then  Information  should be obtained for each season.   The
question is based on the  presumption that periods of maximum stratification
will be important for calculating  critical Initial dilutions.  Field data on
other  potentially  critical   periods  (e.g.,  periods of  longshore  current
stagnation) may  be  necessary for determining  whether  this  presumption  is
true.

     Reduction and  presentation of data  should  be  of sufficient  detail  to
support the interpretation  and analyses  performed 1n the application.   The
following forms of data reduction  and presentation are recommended:
                                    47

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     •    Current persistence tables  - Summary  of the  frequency• and
          duration of specific current  speed and direction events.  For
          example', currents with speeds between 10 and 15 cm/sec (0.33
          and 0.49 ft/sec),  directions  between 260 and 280 degrees (T),
          and durations  of at least 1 h" occurred for 18 percent of the
          data record.

     •    Current speed  and direction  frequency  tables  - Frequency of
          specific current speed and direction Intervals.  For example,
          currents with  speeds  between 5  and 19 on/sec  (0.16  to 0.33
          ft/sec) occurred  for  20 percent  of  the  data record,  and
          currents  with  directions  between  80  and  90 degrees  (T)
          occurred for 23  percent of the data record.

     •    Net coastal  orthogonal component analysis -  By determining the
          predominant directions  of  current flow, a  primary axis for
          orthogonal  component decomposition of each current vector can
          be  selected.   The net  component  relative  to  each  axis can
          then  be determined.    If the currents  do  not  exhibit pre-
          dominant  flow  directions,  an  axis  parallel  to   the local
          bathymetry  or  1n the direction of  an  area of significance can
          be selected.

     •    Current mean  and variance -  For  the predominant directions
          of  current flow or the selected primary axis,  the mean and
          variance of the  current speed can  be  determined.

     Guidance   on  Instrumentation   and  methods  for  oceanographlc  data
collection  Is provided 1n  Design of 301(h) Monitoring Programs for Municipal
Hastewater  Discharges to Marine  Haters  (Tetra Tech  1982a).

          JJ.fl.5.   Do  the  receiving  waters  for  your  discharge contain
          significant amounts  of  effluent  previously discharged  from the
          treatment  works  for which you are applying  for a section 301 (h)
          modified permit? [Subpart 125.57(a)(9)]
                                     48

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    Large and small dischargers oust respond.

     Applicants  should  explain  the  basis  for  their  response  to  this
question.   Explanations should reflect the  hydrographic  characteristics of
the receiving  environment and  the behavior of  the effluent plume through
time.   Applicants that respond negatively to this question should demonstrate
that little  or  no previously discharged effluent will  be advected Into the
ZID (after having been transported out of the ZID) to become entrained in the
effluent plume.  This demonstration will be relatively simple for applicants
that discharge to open  coastal  areas  where currents are unidirectional  most
of  the time.   Those applicants should be able to plot  effluent transport
through time, and  thereby demonstrate that little  or  no  effluent re-enters
the ZID.   The demonstration  will  be much more  complicated  for dischargers
Into estuarlne  environments  where tidal currents oscillate.   In estuaries,
effluent  transported away from the ZID during  the first  half of  a tidal
cycle may be transported back Into the ZIO on the second half of that cycle.
If  effluent  1s  likely  to be transported  back  into the  ZID, the applicant
should estimate the quantities of effluent that would be entrained.

     In responding to  this question,  applicants  should demonstrate that all
applicable water quality standards and water quality criteria are met at and
beyond  the  ZID  boundary.    If the  dilution water  contained  significant
quantities  of  previously discharged  effluent,  it   is  unlikely   that  an
applicant would  be  able to meet all  applicable  water  quality standards and
criteria.  Responses given  for Questions  II.D.I, II.D.2,  and II.D.3 of the
Application Questionnaire may be cited to support this demonstration.

          1J.B.6.  Ambient water quality conditions during the  period(s) of
          maximum  stratification:   at  the zone of initial  dilution (ZJD)
          boundary,  at other areas  of potential  impact,  and  at  control
          stations.  [Subpart 125.62(a)]

               a.   Provide profiles  (with depth)  on  the following for the
                    current   discharge  location   and  for  the  modified
                                    49

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     discharge   location,   If  different   from  the .current
     discharge:

     •  BOD5 (mg/L)
     -  Dissolved oxygen (mg/L)
     -  Suspended solids (mg/L)
     -  pH
     •  Temperature (°C)
     •  Salinity (ppt)
     -  Transparency (turbidity, percent Tight transmlttance)
     -  Other  significant  variables (e.g.,  nutrients,  toxic
        pollutants and pesticides, fecal coll form bacteria)

b.   Provide available  data on the following in the vicinity
     of the current discharge  location and  for the modified
     discharge   location,   If  different   from  the  current
     discharge:

          Dissolved oxygen  (mg/L)
          Suspended solids  (mg/L)
     -    pH
          Temperature (°C)
          Salinity  (ppt)
          Transparency   (turbidity,   percent   light  trans-
          mlttance)
          Other significant  variables (e.g., nutrients, toxic
          pollutants and pesticides, fecal coliform bacteria)

c.   Are  there  other  periods  when  receiving  water quality
     conditions  nay be more critical  than  the period(s) of
     maximum  stratification?   If  so,  describe  these other
     critical  periods and  the data requested in 5.a. for  the
     other  critical period(s).  [Subpart 125.62(a)(l)]
                      50

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*** Large dischargers must respond to Parts a and c.   Small  dischargers must
respond to Parts b and c.
                                                                    •
     To  document the  periods  of maximum  stratification,  temperature  and
salinity profiles that  are sufficient to determine the most  stratified and
the typical conditions should be provided for each oceanographic season.  The
•most stratified" temperature and salinity profile with depth 1s the profile
that will  produce the  lowest  Initial  dilution  (see  Question  III.A.I  for
definition).  In some locations, such a  profile  has the steepest gradients of
temperature  or  salinity  near  mid-depth.    Both  temperature  (expressed  In
degrees C) and salinity  (expressed  In ppt)  should be measured accurately to
two decimal  places  so  that density  (expressed In gm/ciP)  can  be computed
accurately to  five decimal places.    Also, only measured  profiles should be
provided.  Averages of measured profiles or "representative" profiles should
never be substituted.  Density profiles should exhibit a stable water column
over the plume he1ght-of-r1se  (I.e.,  no higher  density water should overlie
lower density water).   The minimum period of time over which oceanographic
data must  be collected  to establish  typical and  most  stratified conditions
1s 1 yr.   Because oceanographic conditions vary among years,  1t 1s  recom-
mended that data collected over 5 yr  be provided.

     Sampling  for  nutrients, coll form  bacteria,  and  other  major variables
may be  conducted at  selected  depths.   Seech1  disc  depth  data  should  be
provided  1f transparency  data  are  not available.    However,  because  the
Seech 1   disc measures  transparency  from the surface  down  Into  the  water
column, use  of the Seech 1  disc Is not  appropriate when  the effluent plume
does not surface.   In addition, because sunlight  greatly Increases die-off
rates of enteric bacteria  (ElHot and Colwell  1985; Crane  and Moore 1986),
bacteriological  sampling  should  be  conducted  during early  morning  or  at
night.    Ambient water  quality  data  collection procedures  and requirements
are different for existing  and  for proposed or relocated discharge locations,
as discussed 1n Design of 301(h) Monitoring Program for Municipal Hastewater
Discharges to Marine Haters (Tetra Tech 1982a) and summarized below.
                                     51

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     For  existing discharges, station  locations  should  Include  sampling  at
the  ZID  boundaries  (both  upcurrent  and  downcurrent),  at control  (I.e.,
background  ambient)  stations,  along  the  primary  axis  of the  longshore
component  of the current  (both  upcurrent and downcurrent),  at Intermediate
upcurrent stations located between the ZID boundary and the upcurrent control
station,  and  1n  potential Impact  areas (e.g.,  In  the nearshore  zone  and
close  to  areas  with  distinctive  habitats).    The applicant  should  use
Information  on local currents and wastefield dispersion patterns  to select
sampling   station  locations   In  potentially  Impacted  areas.     Sampling
stations located  at the ZID boundary, at control  stations along the primary
axis of current,  and at Intermediate upcurrent stations should be 1n waters
of  approximately  the  same  depth.     Control (I.e.,   background  ambient)
stations  should  be  located  In  areas  not  Influenced  by  the  applicant's
discharge.  The Intermediate upcurrent stations are Intended  to represent the
approximate  residual  wastefield  concentrations   (I.e.,  affected  ambient)
upcurrent of the discharge location to account for potential  recirculatlon of
previously  discharged effluent  (by  reversing tidal  currents,  upwelUng,  or
stagnant net circulation).  Data should be  collected at the  Intermediate and
ZID stations at least twice during the day (e.g., high and  low tide slack),
to allow evaluation  of  short-term conditions.  The duration  of the longshore
current  1n  relation to  the time  of  sampling   1s  an   Important  factor  in
determining whether  the Intermediate upcurrent stations  are representative of
persistent conditions or of only a temporary  plume reversal.  For discharges
Involving  outfall  relocation,  monitoring  stations  must be located  at  the
existing  discharge  site  until  cessation  of  that  discharge,  and  at  the
relocation site.

     For  each  survey,  the following Information  should  be  submitted along
with the data:  a chart showing exact locations of the stations, the depth at
which the  measurements were  taken,  and the  sampling dates  and  times.   For
existing  discharges,   the  applicant  should  state  whether  effluent  was
discharging  from the outfall  at the time  of the survey and should provide
the flow rate,  BOD§  concentration, pH,  and  suspended solids  concentration of
the effluent,   If  available.    Any unusual meteorological  or oceanographic
conditions  (e.g.,   storms,  onshore   transport,   low  or  stagnant  longshore
                                     52

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currents)  should  be  discussed.    Current  data  or  other  oceanographic
Information  (e.g., drogues)  should  be  deployed  at  the time of the survey to
determine the direction of movement of the wastefield.

     Other  periods  when water quality  conditions  may  be  more  critical
Include  periods of  maximum  hydraulic loading  from  the  POTW,  exceptional
biological activity,  poor background water quality, minimum stratification,
low  net  circulation,  and  low  effective  net  flushing  or low  Intertidal
mixing.  The latter three cases represent the potential for redrculatlon of
previously discharged effluent.  The  degree of redrculatlon would become
significant  1f  1t  caused  the discharge to  violate  water quality  criteria at
the ZID boundary, when under normal  circulation conditions it would meet the
criteria at the ZIO boundary.

          II.0.7.   Provide  data on steady state  sediment  dissolved oxygen
          demand   and dissolved oxygen   demand  due  to  resuspension  of
          sediments in the vicinity  of your current and modified discharge(s)
          (mg/L/day).

*** only large dischargers must respond.

     Dissolved  oxygen  depletion due to steady  sediment  demand  and sediment
resuspension depends  on  sediment composition (e.g., grain size distribution
and  organic  content),   sediment accumulation  rates,  current  speeds,  and
circulation  patterns.    Field or laboratory measurements can sometimes be
used to determine  oxygen  consumption  rates.   If such measurements are made,
the results and procedures used should be described.

     II.C.  Biological Conditions

     In the  Section  301(h)  process,  the determination of adverse biological
effects  Involves  assessing  whether or not  a  BIP of shellfish,  fish,  and
wildlife  exists  in  the vicinity  of  the  discharge  and in  other  areas
potentially  affected by  the  discharge.   Since the  BIP concept  forms an
                                     53

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Integral part  of the applicant's biological assessment, it is  Important  to
establish  the  meaning  and Interpretation of the term  in  the context of  a
Section 301(h) biological  demonstration.

     The term  "population" does  not mean  a reproductive  unit of  a  single
species but rather all biological  communities existing 1n the receiving water
body.   Similarly, the  terms  "shellfish," "fish,"  and  "wildlife" should  be
Interpreted  to  include  any  and  all   biological  communities that may  be
affected adversely by a marine POTU discharge [Subpart 125.58(y)].

     A BIP is  defined in the Section 301(h) regulations [Subpart 125.58(f)]
as  "an  ecological community  which:  1) exhibits characteristics similar  to
those of nearby, healthy communities existing under comparable but unpolluted
environmental  conditions; or  2)  may reasonably be  expected  to become  re-
established  1n  the  polluted  water body  segment  from  adjacent waters  if
sources of pollution were removed."   Balanced  indigenous  populations occur
in unpolluted  waters.   The second part of the definition concerning the re-
establishment  of communities Is  included because  of its  relevance to pro-
posed,  Improved  discharges and to discharges into waters  that  are  stressed
by sources of  pollution other than the  applicant's modified discharge.

     The biological  community characteristics that might  be  examined in  an
evaluation of  a BIP  include  (but are  not  limited to)  species composition,
abundance, biomass,  dominance, and  diversity;  spatial  and temporal distri-
butions; growth  and  reproduction of populations; disease frequency; trophic
structure  and  productivity  patterns;  presence  or  absence  of  certain
Indicator species; bioaccumulatlon of toxic  materials; and the occurrence of
mass mortalities of fish  and  invertebrates.

     The first step  in an applicant's BIP demonstration  is to define the
"indigenous  population"   and  establish  the  natural  variability  of  the
"balanced  population."    Because  U.S.  EPA  has determined  thai these  are
observable characteristics of  natural  that communities  that exist  in the
absence of human disturbance, a comparative  strategy is found throughout the
Section  301(h)  regulations.    Biological variables  of concern within  and
                                     54

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beyond the ZID  should  be  compared  to the range of natural  variability found
1n comparable but unpolluted habitats.

     The  extent of documentation  provided  by the  applicant 1n  the  marine
biological  assessment  should  reflect  the  quality   and  quantity  of  the
effluent and the sensitivity of the receiving  environment.  Data requirements
will probably  be least for  applicants without substantial  Industrial  waste
sources  whose  discharges  Into ocean  waters do  not  potentially  affect
distinctive habitats of limited distribution or Important fishery resources.

          II.C.I.     Provide  a  detailed  description  of  representative
          biological  communities  (e.g., plankton,  macrobenthos,  demersal
          fish,  etc.)  In  the vicinity  of  your  current  and modified dis~
          charge(s):  within the ZID, at the ZID boundary,  at other areas of
          potential  discharge-related  impact,  and  at reference (control)
          sites.   Community characteristics  to  be described shall  include
          (but  not  be  limited to)  species composition; abundance; dominance
          and  diversity;  spatial/temporal  distribution;  growth  and  repro-
          duction;  disease  frequency;   trophic  structure  and  productivity
          patterns; presence of opportunistic species; bioaccumulation  of
          toxic materials; and the occurrence of mass mortalities.

*** Only large dischargers must respond.

     Of  the  marine communities that  may be  affected by POTW discharges,
benthic communities or other communities that depend  upon the  benthos as a
food source  (I.e.,  bottom-dwelling or bottom-feeding  organisms) are usually
the most  sensitive to pollutants.   The rate  of  accumulation  of discharged
solids  and  associated  toxic  substances near  a  POTW outfall   affects  the
magnitude and extent of Impacts to benthic communities.  Based on the review
of biological  conditions  near both large and  small discharges  in a variety
of marine  and  estuarlne  environments,   it  is apparent that the effects  of
POTW discharges on  the benthos  are determined primarily  by the  influence of
the  local  hydrographic  regimes  on  solids   deposition  and  accumulation.
Observed  biological  effects  in  areas of solids  accumulation  are generally
                                     55

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associated  with  decreased  abundances  of  suspension-feeding  animals  and
Increased  abundances  of deposit-feeding  animals.   Such  effects would  be
expected  to occur  1n  sediments  enriched with  organic  matter (e.g.,  from
POTWs).

     The biological  Information must be used to describe existing  conditions
near the  discharge  and to determine whether or  not  a BIP exists  (or will
exist) near the existing and modified discharges.  This  descriptive Infor-
mation must be used  as the basis for the applicant's  response to Question
III.D.I.

     Applicants   must  submit  descriptions  of  representative  biological
communities  (typically benthic Infauna and demersal fishes) 1n the receiving
water body.  These  descriptions  will  form the basis for the comparative BIP
demonstrations.    It  1s  Important  that  the  applicant   assess  biological
community characteristics  at  a minimum of  four sites:  within the ZID, at or
Immediately  beyond  the  ZIO boundary,  within the  expected discharge impact
area outside the  ZID,  and  at  appropriate reference sites.

     Benthic  data  should  be adequate  to  perform  valid statistical  and
community  analyses  for the  purposes  of determining  whether or  not  the
following conditions  exist:

     •    Benthic community  structure  in the  discharge  area differs
          from  that  1n the control area

     •    Benthic biomass  in  the discharge area differs  from that in
          the control  area

     •    Opportunistic or pollution-tolerant species dominate benthic
          communities in the  discharge area

     •    Anoxic  sediment  conditions occur in the discharge area
                                     56

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     •    Distinctive  habitats  of limited distribution  (when  present)
          are adversely affected by the applicant's discharge

     •    The discharge contributes  to or perpetrates ambient  stresses
          In the receiving environment (stressed water discharges only).

     When the applicant's discharge Is located In an area of soft substrates,
sediment data  must also be  collected simultaneously with the  benthlc com-
munity  at  each  sampling  station.    These  data should  Include grain size
composition and  a measure of organic content.  Data on  Kjeldahl  nitrogen,
sediment 6005, and other sediment variables may also be collected.  Sediment
data  will   be  used  to  Identify correlations between  benthlc  community
structure  and  attributes  of the  sedimentary environment 1n the  receiving
waters.   Detailed guidance  for evaluating benthlc community conditions in
the vicinity of outfall Is given 1n Appendix C.

          I1.C.2.   a.   Are distinctive habitats of limited  distribution
          (such as  kelp beds or  coral reefs)  located in  areas potentially
          affected by the modified discharge?  [Subpart 125.62(c)]

          b.   If  yes,  provide  information on  type,  extent,  and location of
          habitats.

*** Large and small dischargers must respond.

     "Distinctive habitats of limited distribution"  Include  marine environ-
ments whose  protection Is of special  concern because of their ecological
significance  or  value  to  humans.   These  habitats   include,  but are  not
limited to, coral reefs, kelp beds, seagrass meadows, salt marshes, spawning
or nursery  areas  for  commercial  species,  sites  of  aesthetic  appeal,  and
rocky intertidal  habitats  (where -they  are uncommon).  Distinctive habitats
of limited distribution may  be  highly  susceptible to the  potential  effects
of discharged  suspended solids  and  nutrients  on  the unique floral   (e.g.,
kelp, seagrass) or faunal  (e.g.,  coral) components of the communities.  The
potential  for  adverse  effects  of bioaccumulation of toxic substances is
                                     57

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also  relatively  high  because  sessile  floral  and  faunal  organisms  may
constitute  Important  trophic  pathways within  these communities.    These
attached  communities  are  also  susceptible  because  of  the potential  for
continuous exposure to the  effluent plume.

     The  applicant must  describe distinctive  habitats  of  limited  distri-
bution within the receiving water environment, as follows:

     •    Kinds  of  distinctive  habitats  that  occur In the  general
          vicinity of the discharge

     •    Areal extent and  location of the habitats 1n the region (shown
          on a map)

     •    Approximate distance from the discharge to sensitive habitats

     •    Physical  characteristics  of  each  distinctive  habitat (water
          column and substrate)

     •    Species composition of the  flora and fauna

     •    Abundance  or  percent  cover  (as  applicable)  of  resident
          species

     •    Spatial  and temporal  variations  1n  the  biotic  and  abiotic
          components of each distinctive habitat present.

The basic Information supplied by the applicant is expected to be descriptive
in  nature,  and  should  not require  field  surveys.   Possible  sources  for
information on  distinctive habitats  Include  contacts with  local  offices of
state  conservation agencies,  and literature  and  resource  maps,  which  are
available for many areas.
                                     58

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          JJ.C.3.   a.   Are commercial or  recreational  fisheries  located in
          areas potentially  affected  by the discharge?  [Subparts 125.62(c)
          and (d)J

          b.  If yes,  provide Information on  types,  location,  and value of
          fisheries.

    Large and small dischargers oust respond.

     Assessment  of  Impacts   on  fisheries  1s  Important  because of  their
economic significance,  their recreational  potential,  and  the  potential  for
human consumption of contaminated organisms.   The  applicant  should provide
Information on  all fishery resources, both  harvested  and  unharvested, near
the  outfall  and  In other areas  potentially  Influenced by the  discharge.
Emphasis should  be  placed upon regulatory  or health-related  factors that
prevent utilization of  the resource,  especially if  such factors are related
to contamination.  Sources of Information include natural resource agencies,
public health agencies,  local anglers,  and academic Institutions.  For this
assessment, the applicant should  specify  where species of  recreational  or
commercial   Importance  occur  (I.e.,  in  the  immediate  vicinity  of  the
discharge,  in the general  region of  the discharge,  as migrants through the
region).

     The immediate vicinity  of  a  discharge includes  the  outfall structure
and the area associated with the  discharge plume or clearly impacted by the
deposition of  discharged  sediment.    The  spatial  extent  of  the fisheries
data will depend  on  the size and  potential effects  of the discharge, and on
the  characteristics  of  the  data.   Many state fish and game  agencies have
established statistical areas for recording fisheries data.  In these cases,
an  applicant  can consider  regional  fisheries  as  those  occurring  in  the
statistical block that  includes  the  outfall.    If the outfall  is located
within an embayment  or estuary where fisheries occur,  the applicant should
address commercial  and  recreational  fisheries throughout the  embayment or
estuary.
                                     59

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     Distances of the various fishery resources from the discharge should be
provided.  The following  Information should be provided:

     •    Magnitude of the fisheries

               Effort  levels  (e.g.,  number  of vessels  or number  of
               fishermen)

               Economic value of commercial landings or sport fishery

     •    Temporal pattern of the fisheries.

     II.D.  State and Federal Laws  fSuboarts  125.61 and 125.621 a)(1)1

          II.D.I.    Are  there  water  quality  standards  applicable to  the
          following pollutants for  which a modification is requested:

                    Biochemical oxygen demand or dissolved oxygen?
                    Suspended  solids,  turbidity,   light  transmission,  light
                    scatteringt or  maintenance  of the euphotic zone?
                    pH of the receiving water?

*** Large and small dischargers must respond.

     Applicants should  contact  the  state water quality agency for an answer
to this question.

          II.D.2.   If yes,  what is  the water use classification  for your
          discharge  area?   Hhat   are  the  applicable  standards for  your
          discharge area  for each of the parameters for which a modification
          is  requested?  Provide   a  copy of all  applicable  water quality
          standards or a  citation to where they can be found.
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*** Large and saa77 dischargers oust respond.

     Applicants should contact the  state water  quality agency  for an answer
to this question.

          71.0.3.     If   there   are  ho  directly  corresponding  numerical
          applicable  water  quality standards approved by EPA,  provide data
          to  demonstrate  that  water  quality  criteria  established  under
          Subsection 304(a)(1) of the Hater Quality Act are met at or beyond
          the boundary of the ZID under critical environmental  and treatment
          plant  conditions  In  the waters  surrounding or  adjacent  to  the
          point  at which  your  effluent  1s discharged.    [Subpart  125.62-
          (*)(!)]

     At the  time  the  301(h) modification  becomes  effective, the applicant's
outfall  and dlffuser must  be  located and  designed  to   provide  adequate
dilution, dispersion, and transport of  wastewater to meet,  at  or beyond the
ZID, all applicable water quality standards and all applicable  water quality
criteria  for  which  there  are  no  corresponding   approved  water  quality
standards.

     To demonstrate compliance with water quality criteria, applicants must
demonstrate  the  applicable  numerical  criteria  are  not  exceeded  after
critical Initial  dilution.   Guidance for performing such  demonstrations is
given under  Questions III.B.1-III.B.6  for conventional water  quality vari-
ables,  under Questions  III.E.2  and  III.F.I  for conventional   and pathogen
variables,   and   under   Questions   III.H.1-III.H.4  for  toxic  substances.
Applicants are reminded  that  demonstrations  of compliance  must  be made for
the applicant's discharge in combination with pollutants from other sources.
Hence,  data  on pollutant  loadings in  the  ambient receiving waters  may be
required  to calculate   values   of  water  quality  variables  after  initial
dilution.

     Another approach that the  U.S.  EPA has  used to  assess  the potential
impacts  of  wastewater  discharges   on water quality and the  biota  in  the
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receiving  environment Is  the water  quality-based  toxics control approach.
Although  this  approach  Is  not directly  applicable to  the demonstrations
required  to answer this  question,  Information derived from Us use may be
used to further support the  applicant's  response.   Guidance  for  Implementing
the water quality-based toxics  control approach Is  given  1n  Appendix F.

          II.D.4.  Hill the  modified discharge:  [Subpart 125.59(b)(3)]

                    Be  consistent   with   applicable   State  coastal  zone
                    management  program(s)  approved under the  Coastal Zone
                    Management  Act  as amended, 16 U.S.C.  1451 et seq.?  [See
                    16 U.S.C. 1456(c)(3)(A)]
                    Be located  In a  marine sanctuary designated under Title
                    III of the  Marine Protection, Research, and Sanctuaries
                    Act (HPRSA) as  amended, 16 U.S.C. 1431 et seq., or in an
                    estuarlne sanctuary designated under the  Coastal Zone
                    Management  Act as amended,  16  U.S.C. 1461?  If  located
                    In a  marine sanctuary designated under Title III of the
                    HPRSA,  attach  a  copy of  any  certification  or permit
                    required   under   regulations   governing   such  marine
                    sanctuary.   [See 16  U.S.C.  1432(f)(2)]
                    Be consistent with the Endangered Species Act as amended,
                    16 U.S.C.  1531   et  seq.?   Provide  the  names  of  any
                    threatened  or endangered species that inhabit or  obtain
                    nutrients  from  waters  that  nay  be  affected  by  the
                    modified discharge.   Identify any critical  habitat that
                    may be affected  by  the modified discharge  and evaluate
                    whether  the modified discharge  will affect  threatened or
                    endangered  species  or modify  a critical habitat.  [See
                    16 U.S.C. 1536 (a) (2) J
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    Large and small dischargers oust respond.

     Applicants  should   contact   the   National   Marine  Fisheries  Service
(NMFS), U.S. Fish and Wildlife Service (USFWS), and applicable state coastal
zone management agency for answers to this question.

          JJ.0.5.  Are you aware of any State or Federal laws or regulations
          (other than  the Clean Hater Act or  the  three statutes identified
          in item 4 above) or an Executive Order which is applicable to your
          discharge?  If  yes, provide  sufficient information to demonstrate
          that  your  modified  discharge  will  comply  with  such  law(s),
          regulation(s), or order(s).  [Subpart 125.59 (b)(3)]

*** Large and small dischargers must respond.

     Because  each  application  for  permit  relssuance  Is  considered  to  be
an application for  a new NPOES permit,  applicants are required  to provide
new determinations  of  compliance  with  all  applicable  local,  state,  and
federal laws and regulations, as Indicated  above.   Moreover,  in response to
Question II.0.5, applicants should demonstrate compliance with federal  water
quality criteria established by the U.S. EPA (1986a) [Subpart 125.60(b)].

     Individual states often  have  water quality standards that  must be met
Independently from federal water quality criteria.  State standards that are
applicable to the discharge  must be provided  In  this  section,  and determi-
nations  of  compliance  with   those  standards  must be  provided  1n  Section
III.B.6.  Occasionally,  state water quality standards  are dependent on the
location of the outfall  dlffuser.   If the  effluent wastefield  1s trans-
ported to a location having different  standards  than  the  dlffuser location,
then both sets of standards apply.
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III.  TECHNICAL EVALUATION

     III.A.  Physical Characteristics of Discharge fSuboart  125.62fall

          III.A.I.   Uhat Is the critical  Initial dilution for your  current
          and  modified  discharge(s)  during  1)  the period(s)  of  maximum
          stratification?   and  2)  any other critical  period(s) of discharge
          volume/composition,   water  quality,   biological   seasons,   or
          oceanographic  conditions?

*** large and small dischargers must respond.

     POTW  effluents  are  normally discharged  Into  marine  waters  through
outfalls  that range from  open-ended pipes  to extensive  diffusers.    The
characteristics  of  the  effluent  and  the  receiving water,  the  diffuser
design,  and the depth  of  discharge  will  determine the amount  of effluent
dilution  achieved.    As shown  in  Figure  1,  the  lower-density  (nonsaline)
discharged  effluent  creates a  buoyant  plume  that rises rapidly  toward  the
water surface, entraining  significant amounts of ambient  saline  water.   The
momentum  and  buoyancy of the discharged  effluent  are primarily  responsible
for the entrainment  of  dilution water (I.e.,  mixing of ambient  saline water
with effluent).   As the plume  rises  and  entrains  ambient  saline water,  Its
density increases and Its  momentum and  buoyancy decrease  accordingly.   If a
sufficient  ambient  vertical density gradient  or  zone  of  stratification
(like  a  pycnocline  or  thermocline)  Is  present,  the  plume  will  spread
horizontally at the  level of neutral  buoyancy (I.e., where the plume density
equals  ambient water density).   If a  sufficient density  gradient  1s  not
present,  the  diluted  effluent  will  reach  the   water  surface  and  flow
horizontally.    The  vertical  distance  from the  discharge  points  to  the
centerline of the plume  when it reaches the level of neutral buoyancy or the
water surface  is called the "height-of-r1se"  (sometimes referred  to as  the
height to "trapping"  or  "equilibrium" level).

     The  dilution  achieved  at the completion of this process is called the
"initial  dilution."   Dilution is  the ratio  of the total  volume  of a sample
                                     64

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                                        SURFACE
                                                   T
                                                 TRAPPING
                                                  DEPTH
                                         PYCNOCUNE
                                           REGION
TRANSITION
   ZONE
Figure 1.  Wastefield generated by a simple ocean outfall.
                        65

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(ambient water plus effluent)  to  the volume of effluent in the sanlple.   A
dilution of 100  1s,  therefore, a mixture  composed  of 99 parts of  ambient
water to 1  part of effluent.   The Initial  dilution  is a critical  parameter
relative to compliance with water quality standards and is thus discussed in
some detail  In  the  evaluation of both  large and small  applications.   The
magnitude  of  Initial  dilution  achieved  1s dependent  on ambient  density
gradients and diffuser design.

     The lowest  (I.e.,  critical)  Initial  dilution must be computed for each
of  the  critical  environmental  seasons.    The  predicted  peak 2-  to  3-h
effluent flow  for  the new end-of-permit year and  the current speed no higher
than the lowest 10 percent11e current  speed must  be used.    A simplified
procedure for  computing Initial dilution is described  in Appendix A.   Five
U.S. EPA-approved computer models  (I.e., UPLJME, UOUTPLM,  UMERGE, UDKHDEN,
ULINE)  and  several  analytical  formulas  for  computing  Initial  dilution  are
described by Muellenhoff et al. (1985a,b).   ASCII files containing FORTRAN
code for these models  are available from the National Technical Information
Service, 5285   Port  Royal Road,  Springfield, VA  22161  [(703)  487-4650].
These files are  on either nine-track  tape or on floppy diskettes that can be
read by an  IBM-compatible personal  computer.  Muellenhoff  et  al.  (1985a)
discuss  guidelines for  use  of the  models.  During  computation  of initial
dilution by one of  these methods, the flow from each  of the ports modeled
should  be  approximately constant within  a  section  of the diffuser.   The
initial  dilution and trapping depth  for  each section should  be a flow-rate
averaged to obtain  the Initial dilution and trapping depth, respectively,
for  the entire  diffuser.   The depth of  the discharge  1s determined as the
depth of section  below  mean  lower low water or  mean  low water,  or as the
average  for the  diffuser.    If  the adjacent  ports discharge  on opposite
sides  of the  diffuser,  the  port  spacing  should be equal to  the distance
between  ports  discharging on  the  same side of the  diffuser.   (This stipu-
lation  1s  applicable  to  UMERGE  and UDKHDEN,  but not  JUNE.)    Sufficient
documentation  of  the  methods  and   parameters  used  by  the  applicant  to
calculate initial  dilution must be provided so  that the results obtained can
be duplicated  independently.
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     For Many  applicants,  conditions specified In  the  original  application
will  not have  changed, and  1t  will  be  necessary only  to reproduce  the
calculations given 1n the original application.  Other applicants will find,
however, that monitoring data or other Information collected during the term
of the original modified permit requires that new calculations be performed.
For  example,   new calculations  will be  required  where  the  water  column
density  profile  Is  better  defined, effluent flows  have  changed or  are
expected to change, or the number of open ports has changed.

          III.A.2.  Hhat are  the  dimensions  of the zone of initial dilution
          for your modified dlscharge(s)?

*** Large and small dischargers must respond.

     The ZID 1s the region  of Initial  mixing surrounding or adjacent to the
end  of  the  outfall  pipe  or diffuser  ports and  Includes the  underlying
seabed.   The  ZID describes  an  area  In which  Inhabitants,  Including  the
benthos,  may  be  chronically  exposed  to  concentrations  of  pollutants  in
violation of  water quality  standards  and criteria or at  least  to concen-
trations more severe than those  predicted  for critical  conditions.  The ZID
1s not  Intended to describe  the  area bounding the entire mixing process for
all conditions, or the total  area Impacted by the sedimentation of settleable
material.

     In general,  the  ZID can be  considered  to Include  that bottom area and
the water column  above  that  area  circumscribed by D distance from any point
of the  diffuser,  where D  1s equal  to  the  water depth.   Several  different
diffuser  configurations  and  corresponding   ZID   dimensions  are   shown  in
Figure 2.  The water depth  used  should  be the maximum water depth along the
diffuser axes  with respect to mean lower low water or mean  low  water,  as
applicable.

     Unless changes to the outfall system have been made or are anticipated,
or unless Incorrect water depths or outfall characteristics were used In the
original Section  301(h) application, the calculation  presented  here should
                                     67

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        Y-DIFFUSER
        SINGLE POINT
LINEAR DIFFUSER
  L-DIFFUSER
                       Note: d » Water Depth
Figure 2.  Diffuser types and corresponding ZIO configurations.
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be Identical  to  that presented in the original application.   Repetition  of
the  calculation  1n  the application for  relssuance of  the Section  301(h)
modified permit Is necessary to confirm that all values used In the original
application were correct, and that the outfall system has not,  and will  not,
change over the term of the new permit.

          III.A.3.   Hhat  are the effects of  ambient currents  and stratifi-
          cation on  dispersion and transport of  the discharge plune/waste-
          fleld?

*** Only large dischargers oust respond.

     A  general   description  of  the ambient  currents  expected within  the
Influence of the dlffuser site Is required by U.S. EPA.  Since this descrip-
tion  1s  primarily of  use in  determining  where the effluent  wastefield  Is
likely to  be transported  during several  days'  time,  the response  to  this
subsection should  be of sufficient detail  for this purpose.   Knowledge  of
the  subsequent  movement  of  the wastefield  is also needed to  address  the
potential for re-entralnment of  previously  discharged  effluent, which could
effectively  increase wastefield  concentrations at the boundary of the  ZID.
The applicant should take Into account that dilution water is entrained into
the  effluent plume  throughout the  depth  over  which  the plume  rises.   The
diluted  wastefield  may  be  transported  by  either  surface  currents  or
subpycnocllne currents at different times during a tidal  cycle.  In a region
where  currents  are  predominantly  tidal,  current  persistence  and  the  mean
current  speed  and its  variance  with  respect to the  primary  directions  of
water flow should be given.  If the currents have large components unrelated
to tidal  influences  (e.g.,  wind-induced  currents),  then  a  more detailed
analysis should  be  performed.   The  mean, variance,  and direction  of  the
tidal  component   should  be  determined,  and  a  synopsis of   the  nontidal
current  speed,  direction,  and  persistence  should be provided.   Vertical
variations in currents are important at depths where the effluent wastefield
is trapped.
                                     69

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     The  basis for  the current estimates  should.be provided.   Acceptable
sources   of  Information  are   site-specific   measurements   and   published
measurements or predictions.  The Tidal Current Tables published annually by
the U.S.  Department  of Commerce (see National  Ocean Survey 1988a,b)  provide
tidal current  Information  for a  large number of locations.  Information from
other published  documents 1s usable 1f the documents  are available  to U.S.
EPA on request. --         ..•-•-

     Expected  or  measured  effluent  dilutions   at   Important   shoreline
stations  should be Included.  Chapters B-I, B-III, and B-IV in Appendix B of
this document  provide  further guidance on  computing farfield dilutions for
water quality  variables.

     Under  certain circumstances, such as low nontidal currents or reversing
tidal currents,  the affected "ambient" water  quality  concentrations of the
ocean water with which the  plume  Is diluted nay be temporarily higher than
the normal  background concentration (I.e., when the  ocean  water 1s unaffected
by the discharge).   This issue  1s of primary concern for discharges located
in estuaries or  semi-enclosed  water bodies but may also be  of concern for
open costal  sites.   To ensure that the discharge meets all applicable water
quality  criteria  during  these  other  critical  conditions,  the  applicant
should  evaluate  the recirculation  potential   of the  existing or proposed
discharge through an analysis of currents,  dye or field mixing studies (for
existing  discharges only),  numerical  modeling analyses   (for  relocated or
proposed  new  discharges),  or  evaluation  of  water quality  data collected
during the  existing  discharge monitoring program.  A monitoring strategy 1s
described below in guidance  for Question III.F  (Establishment  of a Monitoring
Program).

     Dye  studies  are  particularly  useful to evaluate  the recirculation
potential under  short-term  tidal  cycle  Influences  for existing discharges.
Current-meter  data  should  be   made  available  to  evaluate  both the high
frequency (tidal)  and  low frequency  (nontidal)  current regimes that exist at
the time  of the dye  study.
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     For  relocated  or  proposed  new discharges,  numerical  circulation  and
transport models  are the most useful  methods for assessing the  effects  of
ambient  currents and  stratification  on dispersion  and transport  of  the
wastefleld and for  estimating the  potential  for redrculation  of previously
discharged effluent.   There  are two general  approaches.   The first  1s  to
simulate  a  conservative  substance  (I.e.,  no  decay)  as a  tracer for  the
wastefleld to estimate numerical  dilution factors surrounding the discharge.
These  dilution  factors  can be  used  to  estimate  the  affected  ambient
concentration  of any water quality variable as Input  to  the  Initial  and
subsequent dilution techniques  presented- elsewhere  1n this document.   The
second approach,  which  Is more  complex,  Is  to directly  simulate the water
quality variables and  kinetic processes  that govern their fate  (e.g.,  BOD
decay, suspected solids settling).

     Several specific guidelines can be  offered to  applicants  In the use of
numerical models.  Typically, the most critical conditions for redrculation
and build-up  of  previously discharged effluent would occur when the water
column 1s density-stratified 1n  the presence  of  tidally  reversing currents
and low  nontldal  currents, and  the  wastefleld remains submerged below  the
pycnocline  following Initial dilution.   If  such conditions  occur  at  the
applicant's outfall  site,  the numerical  model  should be layered vertically,
with  a  minimum  of  two  layers.    The  plume  should  be discharged Into  the
bottom layer to simulate  the  submerged discharge.   The applicant should set
up the grid  system  for the numerical  model  such  that the smallest segments
are located  in the  vicinity of the dlfruser  and  gradually  increase  in size
with distance  from  the  dlffuser.  The applicant  might choose  to experiment
with grid configuration  by starting with a coarse grid  and then decreasing
the grid size until  the model results do not change greatly.

     A variety of  numerical  circulation  and  transport  models  exist  with
various levels of detail, user documentation,  and  applicability.  Examples
of potentially applicable  models  Include CAFE/DISPER (Wang  and Connor 1975;
Christodoulou et  al.  1976a,b;  Pagenkopf  et al. 1976); TEA/ELA (Baptlsta et
al. 1984; Westerink et al.  1985);  AriathuHa  (1982); Spaulding  and  Ravish
(1984);  and Sheng and Butler (1984).  The applicant must use a model  that is
                                     71

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supported by  a fully documented computer program so that U.S.  EPA and other
Interested parties may conduct  analyses  (I.e., run simulations) on generally
available computer systems.

          III.A.4.   Will  there be  significant  sedimentation  of suspended
          solids  In  the  vicinity of  the  modified discharge?

*** Only small dischargers mist respond.

     The  accumulation   of  suspended   solids   from  municipal  wastewater
discharges may lower dissolved oxygen  concentrations  in near-bottom waters
and cause changes 1n benthic communities.  Accumulation of suspended solids
In  the  vicinity of a  discharge  1s  Influenced  by the  amount  of sol Ids
discharged,  the  settling velocity  distribution  of the  particles  In  the
discharge,  the   plume   he1ght-of-r1se,   and  current  velocities.    Hence,
sedimentation  of suspended solids Is generally  of  little  concern for small
discharges Into well-flushed receiving environments.

     In  response to  this question, the applicant  must predict  the seabed
accumulation  that results from the discharge of suspended  solids Into the
receiving  water.    The  applicant  may  use any  applicable  well-documented
sedimentation model.  A simplified approach for small dischargers  1s provided
in Chapter  B-I of Appendix  B.   A  simplified  sedimentation  model for large
discharges,  or small dischargers  for whom the  simplified  approach  1s not
appropriate,  Is  also described  In  Chapter B-I of Appendix B.   The sedimen-
tation model  DECAL  (a simplified Deposition Calculation) 1s  available as an
Ocean Data Evaluation System  (ODES)  tool.

          III.A.5.   Sedimentation of suspended solids.

          a.   Hhat  fraction of the modified discharge's suspended solids
               will  accumulate  within the vicinity of the modified discharge?
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          b.   Hhat  are  the calculated  area(s)  and  rate(s)  of -sediment
               accumulation within the vicinity of the modified discharge(s)
               (g/ot/yr)?

          c.   Hhat  is  the  fate  of settleable solids transported beyond the
               calculated sediment accumulation area?

    Only large dischargers must respond.

     Information  on the  fate  of  suspended  solids  1s  needed  to  calculate
oxygen consumption  rates and Interpret biological data.   Settling velocity
distributions of the effluent should be provided, 1f available.  Graphs that
show the  settling  velocity  (cm/sec)  and percent  of solids that  settle at
that velocity  or less  are  preferred.   The suspended  solids  concentration
(mg/L), test conditions,  and laboratory procedures that are used  should be
described.

     The  applicant   should  calculate whether  substantial   sedimentation of
suspended solids  occurs.   These calculations should be made  for the annual
period and  for the  critical 90-day period (I.e., the  90-day  period during
which the highest sedimentation  rate  occurs).   The average plume height-of-
rise with respect to the seafloor  should be  used  1n these calculations.  A
simplified procedure for calculating the effect  of  sedimentation  1s described
In Chapter B-I of Appendix B.

     III.B.    Compliance with Applicable  Water  Quality Standards  fSuboarts
     125.61fb) and 225.62fa)1

          III.B.I.  Hhat is  the concentration of dissolved oxygen immediately
          following  initial dilution  for  the  period(s)  of  maximum stratifi-
          cation and any other critical period(s) of discharge volume/compo-
          sition,  water  quality,   biological   seasons,   or  oceanographic
          conditions?
                                     73

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    large and small dischargers oust respond.

     Dissolved oxygen 1n the receiving water 1s diminished by the low oxygen
content and  Immediate dissolved  oxygen  demand  (IDOO)  of the  effluent within
the ZID  and by  the oxidation of  organic material  1n the diluted  effluent
beyond the ZIO.  A simplified procedure for calculating the dissolved oxygen
concentration  Immediately  following   Initial   dilution  1s  explained  1n
Chapter  B-II  of Appendix B.   Note  that  some states  limit the  maximum
allowable depression 1n dissolved oxygen concentration, and that the maximum
dissolved  oxygen depression may not occur  during  the season that  has the
lowest Initial dilution.

          III.B.2.   Hhat  Is the  farfield dissolved oxygen  depression and
          resulting  concentration  due  to  BOD  exertion  of  the  wastefield
          during the  period(s)   of maximum stratification  and any  other
          critical period(s)?

*** Large and small dischargers oust respond.

     A  simplified  procedure for  computing the farfield dissolved  oxygen
depression 1s given 1n Chapter B-III of Appendix B.

          JJJ.fi.3.  What  are the dissolved oxygen depressions and resulting
          concentrations  near the bottom due  to steady sediment demand and
          resuspension of  sediments?

*** Only large dischargers must  respond.

     Suspended sol Ids  that accumulate  on  the  seabed may  exert  a dissolved
oxygen  demand  due  to  continuous  oxidation  of  organic material  at  the
sediment surface and occasional  rapid oxidation of  resuspended sediments.
Estimates  of dissolved oxygen depressions  that  result from steady sediment
demand and resuspension of solids should be  made using the methods described
in  Chapter  B-IV of Appendix B.    If  field or  laboratory  measurements are
available,  the results can be used  in these  analyses.
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          III.£.4.  Hhat Is the Increase in receiving water suspended solids
          concentration  immediately  following   initial   dilution  of  the
          nodi fled discharge(s)?

*** large and small dischargers oust respond.

     Suspended solids 1n the water column may reduce light transmlttance and
thus water clarity.  Reduction of the depth to which sunlight penetrates may
also affect  biological  communities  within the water column.   The suspended
solids concentration following Initial dilution can be-estimated by a simple
mass balance calculation.

     The  formula  provided 1n  Chapter B-V of  Appendix B should  be  used to
calculate  the  receiving  water  suspended  solids  concentration  following
critical  Initial  dilution.    In  cases  where  the  Initial  dilution  or the
concentration of suspended sol Ids 1n the effluent have not changed since the
original application was submitted, and  are  not  expected  to change over the
term of  the new permit,  1t  will  be necessary only to reproduce the calcu-
lation  provided  1n the  original  application.    However,  changes  in either
variable will necessitate recalculating the receiving water suspended solids
concentration.

          III.B.5.   Hhat  is  the  change  in  receiving water  pH  immediately
          following initial dilution of the modified discharge(s)?

*** Only large dischargers must respond.

     The  pH of the  receiving  water  can  be affected  by the  discharge of
highly  acidic  or  highly alkaline  wastes.   Final  pH values  after  initial
dilution  can  be   estimated   from  field  measurements or  calculated  from
carbonate system alkalinity relationships.

     In most settings,  the influence of a municipal  waste discharge on the
receiving water pH 1s small. .  This section provides  a method to calculate
                                    75

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the pH change  of receiving waters due to a waste discharge and to determine
whether standards are violated.

     The pH at completion  of Initial dilution can be estimated from Table 1.
The  values shown  1n  this table  were generated by  a pH-alkallnlty  model
(based on  the carbonate  system)  that simulates the mixing of effluent  and
seawater.   The  methods  used  to  calculate the  values  in  this  table  are
explained  1n  Chapter B-VI of Appendix B.   Because  waste  plumes are usually
submerged  during  Initial  dilution,   no  exchange  with  the   atmosphere  1s
Included.   The  results are  based on  a seawater  alkalinity  of  2.3  meq/L
(Stumm and Morgan 1981),  and  dissociation  constants  from Stunrn  and Morgan
(1981) and Dlckson and  R1ley (1979).

     Effluent  alkalinity  depends on the alkalinity of  the  source water  and
any  Infiltrating water, the type of treatment process,  and  the  volume  and
type of  Industrial  waste  that  enters the  treatment plant.   Effluent alka-
linity  can  range from 0  to 6.0 meq/L.   A typical  value  for effluent
alkalinity 1s  2  meq/L or higher  (Metcalf and Eddy 1979).  Because alkalinity
data are scarce, final  pH values calculated for a range of alka!1n1t1es  are
provided  in Table  1.    If significant  Industrial  waste  Is  present  In  an
effluent,  or  1f  pure  oxygen  or  nltrlficatlon-denitrlflcatlon  treatment
processes  are used,  effluent pH  and alkalinity should  be measured.   For
cases  of weak primary effluents  with no  Industrial  waste  components,  an
alkalinity  value of 0.1  meq/L with  an  effluent pH of 6.0 can  be used to
estimate  the  final  pH.   If the  lowest  effluent pH  1s  6.5  or  higher,  an
alkalinity  value of 0.5  meq/L with  an  effluent pH of 6.5 can  be used to
estimate the final pH.

     The  applicant  should  first estimate  the  pH at completion  of initial
dilution  for the case  when the  effluent  pH  1s  6.0  and the  ambient  pH is
equal  to the  minimum  ambient  pH  in  the  vicinity of the discharge.   The
estimated  value  should be compared with the  appropriate  state standard to
determine whether the standard is  met.
                                     76

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TABLE 1.  ESTIMATE) pH VALUES AFTER INITIAL DILUTION
Seanter
Tenp. °c
Sea water
PH

7.00
7.50
7.70
8.00
8.30
8.50

7.00
7.50
7.70
8.00
8.30
8.50

7.00
7.50
7.70
8.00
8.30
8.50

7.00
7.50
7.70
8.00
8.30
8.50

7.00
7.50
7.70
8.00
8.30
8.50

7.00
7.50
7.70
8.00
8.30
8.50

10

6.97
7.40
7.58
7.89
8.23
8.46

6.80
7.05
7.13
7.29
7.57
7.90

6.70
6.89
6.94
7.04
7.20
7.39

6.53
6.64
6.67
6.72
6.79
6.86

6.95
7.35
7.52
7.81
8.16
8.40

6.90
7.23
7.35
7.59
7.96
8.24

25

6.98
7.46
7.65
7.96
8.27
8.48

6.91
7.28
7.42
7.69
8.06
8.32

6.85
7.17
7.28
7.50
7.86
8.17

6.75
6.97
7.04
7.17
7.39
7.67

6.98
7.44
7.62
7.93
8.25
8.46

6.95
7.38
7.55
7.84
8.18
8.41
5°C
50

6.99
7.48
7.67
7.98
8.28
8.49

6.95
7.38
7.55
7.85
8.19
8.41

6.92
7.31
7.46
7.74
8.11
8.35

6.85
7.17
7.28
7.50
7.87
8.17

6.99
7.47
7.66
7.96
8.27
8.48

6.97
7.43
7.62
7.92
8.24
8.45

75

6.99
7.48
7.68
7.98
8.29
8.49

6.96
7.42
7.60
7.90
8.23
8.44

6.94
7.37
7.54
7.83
8.18
8.40

6.90
7.26
7.40
7.66
8.03
8.29

6.99
7.48
7.67
7.97
8.28
8.48

6.98
7.45
7.65
7.95
8.26
8.47

100

6.99
7.49
7.68
7.99
8.29
8.49

6.97
7.43
7.62
7.92
8.24
8.46

6.96
7.40
7.57
7.87
8.21
8.43

6.92
7.31
7.46
7.74
8.11
8.35

6.99
7.48
7.68
7.98
8.28
8.49

6.98
7.46
7.66
7.96
8.27
8.48
15°C
10 25 50 75
Effluent pH - 6.0 Alk •
6.97 6.99 6.99 6.99
7.42 7.47 7.48 7.49
7.61 7.66 7.68 7.69
7.93 7.97 7.99 7.99
8.27 8.29 8.29 8.29
8.48 8.49 8.49 8.49
Effluent pH * 6.0 Alk •
6.80 6.91 6.95 6.96
7.07 7.30 7.39 7.42
7.18 7.46 7.58 7.62
7.40 7.78 7.90 7.93
7.82 8.15 8.23 8.25
8.15 8.38 8.44 8.46
Effluent pH - 6.0 Alk «
6.70 6.86 6.92 6.94
6.90 7.19 7.33 7.38
6.97 7.33 7.50 7.56
7.12 7.62 7.82 7.88
7.40 8.02 8.17 8.22
7.77 8.29 8.40 8.43
Effluent pH = 6.0 Alk =
6.53 6.75 6.86 6.90
6.65 6.99 7.19 7.28
6.69 7.08 7.33 7.44
6.76 7.27 7.62 7.75
6.88 7.64 8.02 8.12
7.01 8.00 8.28 8.36
Effluent pH « 6.5 Alk >
6.95 6.98 6.99 6.99
7.37 7.45 7.47 7.48
7.55 7.64 7.67 7.68
7.87 7.95 7.97 7.98
8.22 8.27 8.28 8.29
8.44 8.47 8.49 8.49
Effluent pH * 6.5 Alk *
6.90 6.96 6.98 6.98
7.25 7.39 7.44 7.46
7.40 7.58 7.64 7.66
7.70 7.89 7.95 7.96
8.09 8.22 8.26 8.27
8.33 8.44 8.47 8.48

100
0.1
6.99
7.49
7.69
7.99
8.29
8.49
0.6
6.97
7.44
7.64
7.95
8.26
8.47
1.0
6.96
7.41
7.60
7.91
8.24
8.45
2.0
6.92
7.33
7.50
7.82
8.17
8.40
0.5
6.99
7.48
7.68
7.98
8.29
8.49
1.0
6.98
7.47
7.-7
7.97
8.28
8.48

10

6.97
7.43
7.63
7.96
8.28
8.49

6.80
7.09
7.22
7.53
7.98
8.25

6.71
6.92
7.01
7.22
7.65
8.01

6.54
6.67
6.71
6.81
6.99
7.23

6.95
7.39
7.58
7.91
8.24
8.46

6.90
7.27
7.44
7.78
8.15
8.38

25

6.99
7.47
7.67
7.98
8.29
8.49

6.91
7.32
7.50
7.84
8.19
8.41

6.86
7.21
7.38
7.71
8.10
8.34

6.75
7.01
7.12
7.39
7.84
8.15

6.98
7.45
7.65
7.97
8.28
8.48

6.96
7.40
7.60
7.92
8.24
8.45
25°C
50

6.99
7.48
7.68
7.99
8.29
8.49

6.95
7.40
7.60
7.92
8.25
8.46

6.92
7.34
7.53
7.87
8.21
8.42

6.86
7.21
7.38
7.71
8.10
8.34

6.99
7.47
7.67
7.98
8.29
8.49

6.98
7.45
7.65
7.96
8.27
8.47

75

6.99
7.49
7.69
7.99
8.29
8.49

6.97
7.43
7.63
7.95
8.26
8.47

6.95
7.39
7.59
7.91
8.24
8.45

6.90
7.30
7.48
7.82
8.17
8.39

6.99
7.48
7.68
7.99
8.29
8.49

6.98
7.46
7.66
7.97
8.28
8.48

100

6.99
7.49
7.69
7.99
8.29
8.49

6.97
7.45
7.65
7.96
8.27
8.48

6.96
7.42
7.62
7.93
8.25
8.46

6.92
7.34
7.53
7.86
8.20
8.42

6.99
7.48
7.69
7.99
8.29
8.49

6.99
7.47
7.67
7.98
8.28
8.48
                     77

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TABLE 1.   (Continued)
Seauater
Tesp. °C
Seawater
PH

7.00
7.50
7.70
8.00
8.30
8.50

7.00
7.50
7.70
8.00
8.30
8.50

7.00
7.50
7.70
8.00
8.30
8.50

7.00
7.50
7.70
8.00
8.30
8.50

10
-.
6.82
7.06
7.U
7.28
7.54
7.85

7.06
7.56
7.75
8.03
8.31
8.50

7.10
7.59
7.76
8.02
8.29
8.47

7.14
7.61
7.78
8.02
8.27
8.44

25

6.91
7.28
7.42
7.68
8.04
8.30

7.02
7.52
7.72
8.01
8.30
8.50

7.04
7.53
7.72
8.01
8.29
8.48

7.05
7.54
7.73
8.00
8.28
8.47
5°C
50

6.95
7.38
7.55
7.84
8.18
8.40

7.01
7.51
7.70
8.00
8.30
8.50

7.02
7.51
7.71
8.00
8.29
8.49

7.02
7.52
7.71
8.00
8.29
8.48

75

6.97
7.41
7.59
7.89
8.22
8.44

7.00
7.50
7.70
8.00
8.30
8.50

7.01
7.51
7.70
8.00
8.29
8.49

7.01
7.51
7.71
8.00
8.29
8.49

100

6.97
7.43
7.62
7.92
8.24
8.45

7.00
7.50
7.70
8.00
8.30
8.50

7.00
7.50
7.70
8.00
8.29
8.49

7.01
7.51
7.70
8.00
8.29
8.49
15°C
10 25. 50 75
Effluent pH » 6.5 Alk *
6.82 6.91 6.95 6.97
7.08 7.29 7.39 7.42
7.18 7.46 7.57 7.61
7.39 7.76 7.89 7.92
7.78 8.13 8.22 8.24
8.10 8.36 8.43 8.45
Effluent pH « 9.0 Alk -
7.06 7.02 7.01 7.00
7.56 7.52 7.51 7.50
7.75 7.72 7.71 7.70
8.03 8.01 8.00 8.00
8.31 8.30 8.30 8.30
8.50 8.50 8.50 8.50
Effluent pH » 9.0 Alk -
7.10 7.04 7.02 7.01
7.59 7.53 7.51 7.51
7.76 7.72 7.71 7.70
8.02 8.00 8.00 8.00
8.28 8.29 8.29 8.29
8.46 8.48 8.49 8.49
Effluent pH - 9.0 Alk »
7.U 7.05 7.02 7.01
7.61 7.54 7.52 7.51
7.77 7.73 7.71 7.71
8.01 8.00 8.00 8.00
8.26 8.28 8.29 8.29
8.43 8.47 8.48 8.49

100
2.0
6.97
7.44
7.63
7.94
8.26
8.46
2.0
7.00
7.50
7.70
8.00
8.30
8.50
4.9
7.01
7.50
7.70
8.00
8.29
8.49
6.0
7.01
7.51
7.70
8.00
8.29
8.49

10

6.82
7.10
7.22
7.50
7.93
8.21

7.07
7.56
7.75
8.03
8.31
8.50

7.11
7.59
7.76
8.02
8.28
8.46

7.15
7.61
7.77
8.01
8.26
8.43

25

6.92
7.31
7.49
7.82
8.17
8.39

7.02
7.52
7.72
8.01
8.30
8.50

7.04
7.53
7.72
8.00
8.29
8.48

7.06
7.54
7.73
8.00
8.28
8.47
25°C
50

6.95
7.40
7.60
7.91
8.24
8.45

7.01
7.51
7.71
8.00
8.30
8.50

7.02
7.51
7.71
8.00
8.29
8.49

7.03
7.52
7.71
8.00
8.29
8.48

75

6.97
7.43
7.63
7.94
8.26
8.46

7.00
7.50
7.70
8.00
8.30
8.49

7.01
7.51
7.70
8.00
8.29
8.49

7.02
7.51
7.71
8.00
8.29
8.48

100

6.97
7.45
7.65
7.96
8.27
8.47

7.00
7.50
7.70
8.00
8.30
8.49

7.01
7.50
7.70
8.00
8.29
8.49


7.51
7.70
8.00
8.29
8.49
                                                        78

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     The applicant may  also perform laboratory tests when the  predicted pH
values 1n Table 1 Indicate that contraventions of pH standards are possible.
Some of  the buffering constituents  In  municipal  effluents are  not  readily
quantified  (e.g., organic  add llgands),  and have not been  Included in the
calculations used to  produce the table.  The  laboratory  test would  Include
measuring pH of effluent-receiving water mixtures as discussed below.

     If the effluent  pH drops below 6.0, the  applicant should Indicate the
number of times per year effluent pH values fell below 6.0 and the suspected
cause(s)  of those  low  values.   If  effluent  pH values  below 6.0  occur
frequently, a laboratory test  of pH  after mixing the effluent and receiving
water should be  performed  for the critical conditions.   The sample  mixture
should not  be allowed to equilibrate with the  atmosphere.  The pH should be
measured at close Intervals  until  no further  change in pH 1s observed.  The
applicant should describe conditions of the test, including temperature, pH,
and alkalinity  of the effluent  and  receiving water;  initial  dilution; and
the  measured values  after  mixing.    The  measured values  should  then be
compared with  the applicable  standard  to determine whether  a  violation is
likely.  The frequency of violations should be estimated.

          III.B.6.  Does (will) the modified discharge comply with applicable
          water quality standards for:
                    Dissolved oxygen?
                    Suspended solids or surrogate standards?
                    pH?

*** Large and small dischargers must respond.

     The  applicant  must  demonstrate compliance  with applicable  receiving
water quality  standards.   Typically, standards exist  for dissolved  oxygen,
suspended sol Ids, and pH, in which case the results of previous sections may
be used.  If a quantitative state standard exists for turbidity expressed in
a given  turbidity unit, then turbidity  of the effluent  and  the  receiving
water (expressed  in  turbidity units as a  function  of concentration) should
be measured to  demonstrate  that  the  standard will  be  met.    Other  state
                                     79

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standards may  also exist,  such  as for col1form bacteria  concentrations  at
the edge of a mixing zone.  Monitoring data collected during the term of the
original  Section . 301(h)   permit  may  also  be  useful  for  demonstrating
compliance with  applicable receiving water standards and  criteria,  and for
verifying predictions made  1n the original application.

     According  to Subpart  125.57(a)(9),  permits nay not  be Issued  1f the
dilution water  for  the discharge contains substantial  amounts of previously
discharged effluent.    In general,  this criterion will  be met  1f all water
quality standards are met.

     Detailed guidance  for assessing compliance with specific water quality
standards 1s provided 1n Chapters B-VII and B-VIII of Appendix B.

          7/7.5.7.  Provide the  determination required by Subpart 125.61 (b)-
          (2) or,  If the determination has not yet been received, a copy of
          a  letter  to  the appropriate  agency(s)  requesting  the  required
          determination.

*** Large and small dischargers  must respond.

     Because  all  applications  for  reIssuance  of Section  301(h)  modified
permits are considered  applications for new NPDES permits,  all applicants are
required  to  provide   new  determinations  of  compliance,   as   required  by
Subpart  125.61(b)(2).   A  copy of  the  letter that requests  the  required
determination may be provided if the determination by the appropriate state
agency has not yet been received.

     777.C.  Impact  on  Public Hater Supplies fSubpart 125.62(b)l

          III.C.I.    Is there  a planned or  existing  public  water supply
          (desalinizatlon facility)  intake in  the  vicinity of the current or
          modified discharge?

*** Large and small  dischargers  must respond.
                                     80

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     It 1s possible that a public water supply (desa11n1zat1on plant)  Intake
could be contaminated by marine POTU discharges.  Although such a possibility
may  be remote,  the  applicant  should verify  that no  public water  supply
Intakes are  located within 16 km  (10  ml)  of the discharge.   If  none exist
within 16  km (10 mi) of the discharge, no analyses are  required.   The name
of the  agencies contacted and  the person  involved should be  listed  in the
application.

          III.C.2.  If the answer to Question III.C.I. is yes,

          a.   What  is  the location of  the  intake(s) (latitude  and  longi-
               tude)?

          b.   Hill  the  modified discharge(s) prevent the use of intake(s)
               for public water supply?

          c.   Hill  the  modified  discharge(s)  cause  increased  treatment
               requirements for public water supply(s) to meet local,  state,
               and U.S.  EPA drinking water standards?
***
    Large and small dischargers must respond.
     If the  answer  to Question III.C.I is affirmative, the  location of the
desalinization  plant  should  be  shown on  a  nap  with the  discharge  site
marked.  The travel  time to the intake should be estimated using the average
current speed.  Using  the  methods  discussed  In this  document,  the applicant
should show that all water quality standards are met at the intake.

     III.D.  Biological Impact of Discharge fSuboart 125.62(c)l

     POTW discharges can affect biological communities  in the following ways:

     •    Modifications  to structure  of  benthic  communities  (bottom
          dwelling/feeding   fishes   and   Invertebrates)   caused   by
          accumulation of discharged solids on the seabed
                                    81

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     •    Increases  In  phytoplankton  or  macroalgal  growth  due  to
          nutrient Inputs

     •    Reductions  In  phytopl ankton  or  macroalgal  growth  due  to
          turbidity Increases

     •    Reductions  In dissolved  oxygen  due to  phytoplankton blooms
          and subsequent die-offs, leading to mass  mortalities of fishes
          or Invertebrates

     •    B1oaccumulat1on of toxic substances 1n marine  organisms due to
          direct  contact with sediment, 1ngest1on of sediment, direct
          uptake  from effluent, or  Ingestion of contaminated organisms

     •    Induction of diseases In  marine  organisms  caused by contact
          with   contaminated  sediments,   Ingestion  of  contaminated
          organisms, or  exposure to  effluent.

     Host  of   these   potential   impacts  are  associated  with  discharged
particulate  matter.    The  potential effects  of  discharged  solids may  be
compounded by  the toxic substances adsorbed  to these  solIds.   Hence,  the
primary  potential effects  of sediment enrichment by organic  particles  and
sediment  contamination  by  toxic  substances  are  closely  linked,  and  are
generally manifested  in  the same biotic groups.  Discharged effluent solids
tend  to accumulate  near  the sewage  outfalls,  and  bottom-dwell Ing marine
organisms  (e.g.,  benthic macroinvertebrates  and bottom-feeding fishes)  are
potentially affected  by these accumulations because  they  live  in or on the
sediments.

     Additional  environmental  effects are  associated with the discharge of
plant nutrients,  which may  result In eutrophication, especially in estuaries
or coastal embayments.   Related impacts can include stimulation of toxic or
nuisance  algal  blooms.     Such  phytoplankton  blooms  may  adversely affect
commercial and recreational  fisheries  because  the decomposition of phyto-
                                     82

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plankton  after massive blooms  can  cause dissolved oxygen deficiencies and
associated fish or Invertebrate kills.

     Biological assessments  for Improved discharges,  altered discharges, or
discharges Into stressed  waters Involve predictive demonstrations of future
biological conditions near the  outfall  and  elsewhere  In the  receiving water
body.   These analyses may Involve  establishing  relationships between water
quality conditions and biological  conditions and  predicting future conditions
based on  these relationships.   Thus,  biological  assessments  for Improved or
altered discharges  Involve not  only describing existing biological communi-
ties  but  also determining  whether a  BIP will  exist beyond the  ZID after
Improvements or alterations to the discharge.

     To support a Section 301(h)  modification,  the applicant does not have
to  show that conditions  of  each  biological community  at  all points beyond
the ZID fall within the natural range of variation observed at the reference
sites.  Rather, the applicant's assessment should concentrate on determining
the conditions of the following types  of biological  assemblages at control
sites and at the  areas of potential Impact:

     •    Communities  that  are most  susceptible to  impacts  from POTW
          discharges

     •    Communities  with   aesthetic,  recreational,   or   commercial
          importance

     •    Communities  with   distributional   patterns  that   enable
          quantitative  assessment  with reasonable  sampling  effort and
          resources.

     Using this approach,  applicants should be  able  to study the Important
communities  that  are  expected  to  demonstrate discharge-related  effects
while not wasting effort  on studies with a limited potential for providing
meaningful  results.    Based  on   the  review  of  existing   Section  301(h)
applications, the major potential  effects of POTW discharges are associated
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with  benthic  macroInvertebrates and  demersal  fishes.    Because  of  their
distribution  characteristics,  both of  these communities  can be  assessed
quantitatively  with  a  reasonable  level  of  sampling  effort.     Benthic
macrolnvertebrates  are  also the primary food  Items  for demersal fishes  and
early-life  stages  of  certain  other  fishes.    Consequently,  these  two
communities  are linked by a food  web  relationship, and  severe Impacts  on
benthic  macrolnvertebrates may  result  1n secondary Impacts to demersal  or
other fishes.

     Benthic macrolnvertebrates  and demersal fishes are two Important groups
that  typically  warrant BIP  demonstrations.   However,  it should  not  be
assumed  that  these  are  the  only biological  communities  that  should  be
studied  1n all  cases.  The concept of a BIP Includes any and all  biological
communities potentially affected by the discharge.

          HI.D.I.     Does  (will)  a  balanced  indigenous population  of
          shellfish,  fish,  and wildlife exist:

                a.   Immediately  beyond  the 21D of  the  current and modified
                    discharge(s)?
                b.   In  all other areas beyond the ZID where marine  life is
                    actually  or potentially  affected  by  the current  and
                    modified  dlscharge(s)?

*** Large and small dischargers  must respond.

     The  purpose  of  the  question 1s  to  determine whether unacceptable
biological Impacts  occur or will occur beyond  the ZIO.  Effective demonstra-
tions  that  the modified  discharge,  either singly  or In  combination with
other discharges,  does not contribute to adverse biological impacts include
comparisons  of biological  conditions  and  habitat characteristics  among
stations  or groups  of  stations.    The  applicant  should  demonstrate that
biological conditions and habitat characteristics do not differ substantially
among stations  (or  groups  of  stations) In ZID-boundary, nearfield, farfield,
and reference areas.
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     The  applicant  should compare the  ranges  of biological  characteristics
among  the four specified  areas where  communities  are to be assessed.   If
differences  that  are  attributable  to  the  discharge are detected  between
study areas  (e.g., ZID  boundary vs.  reference),  the applicant should assess
the spatial  extent of those  differences.   In addition, the magnitude of the
effect  should  be  characterized  with  regard to the  relative  deviation from
reference  conditions  (e.g.,  percent  reduction  In  species   richness),  the
potential for 1ntertroph1c effects (e.g.,  reductions In fish food organisms),
and  the   potential   for  Involvement  of  recreationally  or  commercially
Important species.

     Numerous  variables  may be used  to describe  and  compare  biological
communities  (e.g.,  numbers  of  species;  total   abundances  of  organisms;
abundances  of  selected  pollution-sensitive,  pollution-tolerant,  and  op-
portunistic  species).   [See Tetra Tech (1987f)  for further  guidance on the
selection of biological  Indices.]  Physical characteristics of the receiving
environment  that  are often  measured Include  water column characteristics,
(e.g.,  depth,  water  temperature, salinity, nutrient concentrations,  chloro-
phyll a concentrations)  and substrate characteristics  (e.g.,  bottom type and
composition).  Information on the physical characteristics of  the environment
may be  used to Interpret  the biological  data and  to determine whether the
discharge  Is  altering   the   physical   or  chemical  characteristics  of  the
receiving environment.

     Species vary in their  sensitivities to  pollutants,  Including  organic
enrichment.   Changes in species composition  and  abundance   begin to  occur
when the  mass  emission  rates of materials  in  a  sewage discharge are suffi-
ciently high to  affect  the most sensitive  species.   As  the abundances of
pollution-sensitive  species  decrease or  are driven to  zero,  abundances of
opportunistic  and pollution-tolerant species  are  typically  enhanced.   For
this reason, changes in  the  values  of community  variables (e.g.,  numbers of
species,  total  abundances, dominance)  are often accompanied by  changes in
the abundances of opportunistic and  pollution-tolerant species.  Additional
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guidance on  the evaluation of biological communities is  provided  in  Appen-
dix C.

Special Considerations for Small Dischargers

     During  the  preparation of  applications  for  original  Section  301(h)
modified permits, many small applicants were able to respond to this question
without conducting  field studies of  biological  communities  1n  the vicinity
of  the discharge.    Those  small  applicants  used  existing Information  to
demonstrate  that  the  characteristics  of  the  discharge  and  receiving
environment  indicated a very  low potential  for adverse  impacts.    If  an
applicant  was   not  required  to collect  biological  information during  the
term  of the existing  permit,  that   applicant  may continue  to  use  other
available  information   to   demonstrate  that  the  characteristics  of  the
discharge  and  receiving  environment  indicate  a  very  low potential  for
adverse Impacts.  Applicants are reminded, however, that such demonstrations
must consider the potential  for adverse impacts of the discharge singly and
in  combination  with other discharges   (1f any exist) [Subpart 125.57(a)(2)].
The following characteristics Indicate a low potential for impact:

     •    Location  of the discharge  in water  depths greater than  10 m
          (33 ft)

     •    Hydrographic conditions  that result  in  low  predicted solids
          accumulation rates

     •    The absence of distinctive habitats of limited distribution
          and the absence of fisheries in the vicinity of the outfall,
          when  such absences are not  due to anthropogenic stresses

     •    The absence of known  or  suspected sources of toxic pollutants
          and pesticides or  low  concentrations of these substances in
          the effluent.
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Most  small  dischargers  that  previously  demonstrated a  low potential  for
Impact  should be  able to  do so  again.   They  only need demonstrate  that
characteristics  of the discharge  and receiving environment did  not  change
greatly during the term of the existing permit.   Monitoring data collected
during the  term  of the original Section 301(h)  modified  permit should also
be useful for such demonstrations.

     Some small  dischargers may not be able  to  demonstrate  a low potential
for Impacts because characteristics of the discharge  or receiving environment
differ from those  listed  above.   In  some cases,  the discharge or receiving
environment may not have exhibited the aforementioned characteristics at the
time  the original  application for a  Section 301(h)  modified  permit  was
prepared.   In others, characteristics of  the  discharge  or  receiving  en-
vironment may  have changed, or additional  information may now be available
that documents a greater  potential  for impact than was previously supposed.
For example,  the composition  of  the  discharge may  have  changed  to include
toxic pollutants or pesticides from a new industrial source.   Alternatively,
a fishery for a  previously underutilized species  may  have  developed in the
vicinity of the discharge,  or research by  local scientists may have dis-
covered  that  the  habitat in  the  vicinity  of  the outfall   is  an important
nursery ground for a commercially harvested species of fish or shellfish.

     When  It  is  apparent for  one or  more  reasons  that  the  discharge or
receiving environment  does not exhibit characteristics that would indicate a
low potential  for  Impacts,  the Regions have  the discretion  to require that
an applicant  perform  a detailed assessment of  biological conditions  in the
vicinity of the outfall.  The level of detail that would be expected in such
a demonstration would  be comparable to that required by large dischargers.

     In some  cases,  the applicant may have  been required to monitor one or
more  biological  communities  under the conditions of the existing Section
301(h) modified permit.  The Region may require the applicant to analyze and
discuss those biological monitoring data in response to this question.  When
biological   monitoring  data  were not collected,  but  concern  exists that the
modified discharge might  cause adverse impacts to the biota, the Region may
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require  the applicant  to  collect biological  data  1n support  of the  ap-
plication for  permit reIssuance.  If the  Region  requires  the collection of
additional  data,  the  Region  should  consult  with  the applicant  well  in
advance  of  the .application deadline, thereby giving  the applicant adequate
time  to design  and  execute  appropriate  studies.   Applicants  required  to
perform these field  surveys should consult Tetra Tech (1982a, 1987a,c,f) for
guidance  on the design  and  execution  of  those  surveys.   To ensure  the
collection,  of  adequate, high quality  data,  the Region should  work closely
with the applicant during all phases of the  necessary studies.

          III.D.2.   Have distinctive habitats of United  distribution been
          Impacted adversely by  the current  discharge and will such habitats
          be Impacted adversely  by the modified discharge?

*** Large and small  dischargers  must respond.

     If  distinctive  habitats  are present  In areas potentially Influenced by
the discharge,  the  applicant should provide Information that documents the
extent and  condition of those habitats.  The applicant should also provide a
detailed  evaluation of  available historical Information  on  the  spatial
distribution  of  any distinctive  habitats near the  outfall  and  In  nearby
control  areas.   Trends  1n spatial  occurrence should be evaluated relative to
historical  discharges by the applicant  and  relative  to  other water quality
or biological factors that may Influence the habitat.

     If  available,   the applicant  should  Include  documentation  of  any long-
term  changes 1n the spatial  extent or  general  health of  the distinctive
habitat.  Examples  of such Information Include areal extent of  kelp beds or
condition  of algal  cover on  coral  reefs.    If  historical  changes  In the
habitat  have occurred,  the applicant should attempt to relate those changes
to  natural  or  pollution-related  events.    For example,   severe storms may
damage coral reefs,  and heavy pedestrian traffic can  degrade  rocky intertidal
communities.

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     •    Health-related   factors   [Including   paralytic   shellfish
          poisoning (PSP),  bacteriological contamination, and bioaccumu-
          latlon of toxic substances]

     •    Economic or marketing considerations

     •    Resource protection closures

     •    Other regulatory closures.

     If reasons for closures are due  to  tissue contamination,  the applicant
should specify the contributing pollutant sources.

     Many  sources  of  Information   are  available to  address  the fish  and
fishery concerns outlined above:

     •    Local anglers

     •    Public, Institutional, and agency libraries

     •    Academic Institutions (e.g., marine science, biology, zoology
          departments; Sea Grant offices;  cooperative fishery research
          units)

     •    Local (e.g., conservation boards), state (e.g., fish and game
          departments),  and  federal  natural  resource  agencies  and
          affiliated  laboratories   (e.g.,   National   Marine  Fisheries
          Service,  U.S. F1sh and Wildlife Service)

     •    Regional   fishery  management  councils  (contact  Information
          available from National Marine Fisheries Service)

     •    County, state,  and federal environmental protection and public
          health agencies.
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     Environmental protection and public health agencies should be contacted
to obtain Information on the health of fishes In the vicinity of an outfall.
These agencies monitor water quality and col 1 form bacteria concentrations In
shellfish  as part  of a  national  public  health  program.   They will  also
provide  Information  on  PSP If It  1s  known to occur In the geographic area.
Depending on the distribution of fishery  resources  and  pollutant levels In
receiving  waters, these  agencies  may  also  conduct laboratory  studies  on
toxic bloaccumulatlon  In  fish species harvested for human  consumption.   An
applicant should  request all available Information concerning the region and
Immediate  vicinity of  the discharge,  and, with the  assistance of  agency
personnel, attempt to determine the discharge's contribution to any observed
fish health  problems.   A conclusion  by  agency personnel  that the discharge
Is not  contributing to public  health problems should  be  documented  by the
applicant.

     State departments  of environmental  protection  or  ecology are generally
responsible  for  recording  occurrences  of fish kills  within  state waters.
Typically, a report  1s  filed by the departmental  agent who Investigated the
kill, recording  such  Information  as the  severity  of the  Incident and its
probable causes.  An applicant should request  and review reports of relevant
fish kills and  document whether the discharge has been Implicated  in any of
these Incidents.

     Most  environmental  protection  and   public  health  agencies  do  not
routinely  assess the  health status  of  fish unless a  serious problem with
toxics  bioaccumulation  1s  suspected in  species  sought  by  commercial  or
recreational  fishermen.   Sources  of Information  on fish  disease or abnor-
malities Include  academic Institutions or  fisheries  agencies, which may have
conducted fish  surveys in the vicinity of  an  outfall.

     A  careful   review  of  available  Information   should  enable  a  small
applicant  to characterize the  local  fish  communities  and fisheries without
an actual field  survey, unless  there  Is  sufficient evidence to Indicate that
the  discharge  has,  or  Is  likely  to,  adversely impact   important  fish
resources.
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     The  applicant  should  evaluate  any  effects  of  the  discharge  with
emphasis on the  physical,  chemical,  and  biological  conditions  that occurred
within the  distinctive habitats 1n  the  vicinity of the outfall  during the
term of  the existing 301(h)  permit.   The applicant's discussion should be
oriented towards an assessment  of  the  potential  for contact  of the effluent
plume with  any nearby distinctive habitats.   In cases where  a distinctive
habitat  occurs  near  an  outfall,  the applicant  can evaluate  Impacts  by
considering the following:

     •    Degree of Initial dilution

     •    Degree of farfleld dispersion

     •    Frequency and direction of waste transport

     •    Lack of prior appreciable harm.

     The most  effective  demonstrations of Impacts  (or the lack of Impacts)
Include  comparisons  of  potentially  Impacted  areas with  reference  areas
beyond the  Influence of  the discharge.   Experience with applications for
Section 301(h) modified  permits has  shown,  however, that  suitable reference
areas for distinctive habitats of limited distribution are often difficult to
find.    The biota  that  characterize  distinctive  habitats  often  require
specific  environmental  conditions  that  occur  dlscontinuously  within  the
blogeographlc  zone,  and  often  only  1n  small  areas.   When a  suitable ref-
erence area for  a distinctive habitat  of limited  distribution  does  not
occur  in the  vicinity  of the  applicant's  outfall,  the applicant  should
present  (to  the  extent  possible)  detailed  Information  on  the  typical
physical,  chemical,  and  biological  characteristics  of  that  distinctive
habitat within  the  blogeographlc  zone.   When suitable data  are available,
applicant should assess potential  Impacts to distinctive habitats of limited
distribution by using  the  graphical  and mathematical  tools  discussed in
Appendix C.
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Special Considerations for Small Dischargers

     When  1t  appears  that  a  small  discharger  1s  causing   (or  has  the
potential  to  cause)  Impacts  to  distinctive habitats  of limited  distri-
bution, the Region may require the applicant to perform a detailed assessment
of distinctive habitats  1n the  vicinity  of the  discharge.   Such a detailed
assessment would be  comparable  to that  required  of large dischargers,  as
described  above.   Therefore,  guidance  provided above and under Questions
II.C.2 and  III.D.I  of this questionnaire  Is  relevant  to  the  performance of
such detailed  demonstrations.   The Region  should  notify  the  applicant well
1n advance  of the  application deadline of the  need for  additional  data on
distinctive habitats, so as to  give the  applicant  adequate  time to design
and execute  appropriate  studies.  Moreover,  the Region  should work closely
with the applicant during all  phases of the studies to ensure that adequate,
high quality data are collected.

          III.0.3.   Have commercial or recreational fisheries been impacted
          adversely by  the current discharge  (e.g., warnings, restrictions,
          closures, or mass mortalities)  or will they be impacted adversely
          by the modified discharge?

*** Large and  small dischargers  must respond.

     If  fisheries  resources are present  1n areas  potentially Influenced by
the discharge, the  applicant  should assess  the  effects  of the discharge on
these  resources by  analyzing  catch records,  market acceptability,  contam-
ination  of  tissues  by toxic substances,  prevalence of disease, and harvest
warnings/closures.

     The  applicant  should  also  determine whether  any potential  fishery
resources remain unharvested in  the area because of warnings or closures.  If
unharvested  resources  are  Identified,  the  applicant  should  Indicate the
reasons why these resources  are  not  utilized,  such  as the following:
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          III.0.4.    Does  the  current  or  modified  discharge  cause  the
          following within or beyond the ZID:  [Subpart 125.62(c)(3)j

               a.   Mass mortality of fishes or invertebrates  due to oxygen
                    depletion,  high  concentrations  of  toxics,   or  other
                    conditions?
               b.   An Increased Incidence of disease in marine organisms?
               c.   An abnormal body burden  of  any  toxic material in marine
                    organisms?
               d.   Any other extreme,  adverse biological Impacts?

*** Only large dischargers must respond.

     This  question  requires  the  assessment of several specific  potential
Impacts  of POTU  discharges.   The  applicant   should  review  and  summarize
available Information on occurrences of mass mortalities of marine organisms
1n the receiving water environment.  The suspected causes of mass mortalities
should  be  evaluated  to  determine whether  any of  these events  could have
resulted  from  the  discharge.    Evaluation  of actual  or  potential  mass
mortalities  Is  especially  Important for  applicants  with discharges  Into
estuaries  or   enclosed   embayments.    Dissolved   oxygen   deficiencies  in
environments  with  limited   flushing  characteristics  may   result from  BOD
Inputs  or  algal  decomposition  following bloom conditions.    Evaluation  of
disease  incidence or  tissue contamination  In marine  organisms  should  be
conducted by spatial comparisons of communities near the discharge (ZID and
ZID boundary) with those in control  areas (see Tetra Tech 1985a-d; 1987d).

     Many  studies have  suggested  that  a relationship  exists between  the
Incidence of disease  In  marine organisms  and  contact with  POTU  effluents.
These diseases Include exophthalmia in  spotfln croakers (Roncador stearnsil)
and white  seabass  (Cynoscion nobilis),  Up  papilloma in  white  croakers
(Genyonemus lineatus), and  discoloration  In  halibut (Hacrostomus pacificus)
(Mearns and Sherwood  1974;  McDermott-Ehrlich et al.  1977).  Bloaccumulation
of chlorinated  hydrocarbons and trace  metals  has  been reported  in marine
organisms collected near  sewage outfalls off southern California.  Affected
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species  Included  the Dover sole  (Hlcrostonus padflcus), rock  crab-(Cancer
anthonyl),  mussel   (Hytllus  californlanus),  and  rock  scallop  (H1 twites
multirugosus)  (McOermott et al.  1976;  Young et al.  1976a;  McDermott-Ehrlich
et al. 1978; and Young et al. 1978;).

     The  discharge  of  sewage  effluents  containing  toxic  substances  can
result In bloaccumulatlon,  especially 1n areas of organic sediment accumula-
tion.    Toxic  heavy  metals  and  persistent   synthetic  organic  compounds
generally have the highest potential for bloaccumulatlon 1n marine organisms.
The  Identification  of substantial  concentrations of such  substances in  the
plant effluent  in combination with either  of  the following  receiving  water
characteristics Indicates the need  for evaluation of bloaccumulatlon:

     •    Evidence   of  effluent   transport  toward   areas   used  for
          shellfish  harvesting

     •    Significant occurrence of Important recreational or commercial
          species and  evidence  of  potential sediment accumulation near
          the outfall.

     The potential  for bloaccumulatlon  may be  evaluated  by the applicant by
comparing the concentrations of toxic substances after initial dilution with
U.S. EPA saltwater criteria.  Two types of  information are required for this
comparison:

     1.   Concentration  of  the pollutant in the discharged effluent

     2.   Critical Initial  dilution.

     The  value of   (1)  divided   by (2) should  then  be  compared  with  the
available criterion.

     Most of the toxic  substances with a high bloaccumulatlon potential will
be associated  with  organic particulates In  the discharged  effluent.   Thus,
in  determining  bioaccumulation  potential, it  is  important  not only  to
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evaluate  concentrations of  these substances  1n the  effluent and .In  the
receiving water  following Initial  dilution,  but also to examine  sediment
accumulation patterns.   Substantial  bloaccumulatlon  Is possible even  when
water  quality  criteria  are  met  because  of  localized  accumulation  of
contaminated  sediments.   Alternatively,   the   applicant  may  be  able  to
demonstrate that bloaccumulatlon  1s not a  serious problem even though toxic
substances  are  present 1n  the  effluent,  by  providing  Information  that
demonstrates the following:

     •    Adequate Initial  dilution

     •    Sufficient circulation  to prevent localized  accumulation  of
          solids or trapping of effluent plumes.

     The degree to which the  applicant may  be required to assess bloaccumula-
tlon  using  field  surveys  1s  also dependent  upon  the  kinds of  organisms
present.   Several  Investigators  have demonstrated  the ability of  bivalve
molluscs  and  crustaceans to accumulate metals and organic  substances  near
sewage discharges  (Young et  al.  1976b,  1978).   Studies  at  some of the same
sites and at  other contaminated  areas  have indicated that  demersal  marine
fishes  do  not  generally  accumulate  metals  in muscle tissue  (with  the
exception of organic mercury) but accumulate organic substances such as high
molecular weight chlorinated hydrocarbons (McDermott-Ehrlich et  al.  1978;
McOermott et   al.  1976).    Thus,  in  the  case  where  an effluent  contains
substantial  quantities of  heavy  metals,   the  potential data requirements
would be  greater  If  shellfish resources  occurred  In  potentially  impacted
areas than  if fishes  constituted the  only  locally  important  resources.
Furthermore, the potential for bloaccumulatlon  would  be less if fishes with
only  transitory  plume  exposure   were present  (e.g.,  pelagic or  migratory
species) than if demersal species dominated in areas of sediment deposition.

     Sessile   filter-feeding  molluscs . that   are  highly   susceptible  to
bioaccumulation,  and that  may  also be important commercial  or recreational
resources,  are  generally   found  in  nearshore  habitats,   especially  in
embayments  or  estuaries.    If  an  applicant can demonstrate  that  shellfish
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resources do not occur  In the outfall vicinity or in other areas potentially
Impacted by  the discharge,  or that  effluent  dispersion  Is  adequate,  tissue
analyses of  Indigenous  biota  may not be required to demonstrate the absence
of  adverse  bloaccumulatlon.     Discharges  located  1n  areas  with  limited
dispersion,  such  as  estuaries  or  embayroents,  may  cause  contamination  of
local  shellfish resources.   In  such cases,  the  applicant should  conduct
analyses  of tissue  concentrations  of toxic  substances Identified  In  the
plant  effluent.   Examples  of  species that  nay be appropriate for  tissue
analyses Include oysters, clams, mussels, crabs, or lobsters.

     An additional situation which will Influence the requirement for direct
assessment  of  bloaccumulatlon  Is  where  other  pollutant  sources  cause
observed contamination of fish or shellfish resources.  This would especially
pertain to  cases of nearby fishery  closures  or harvesting  restrictions  due
to  pollutant Inputs.   In  such  cases, it 1s  important for  the  applicant to
demonstrate  that  Its  discharge  1s  not contributing to the existing contami-
nation.  This demonstration can be accomplished by the previously  described
analyses of  effluent pollutant  concentrations  and  initial  dilutions, or by
evaluation  of  existing information  on the  spatial  patterns  of  pollutant
concentrations  in organisms  or  sediments.   It may  be necessary for  the
applicant to conduct tissue  or sediment analyses if  effluent  and dilution
analyses indicate  the potential for bloaccumulatlon  and if sufficient data
are  not available to  determine  pollutant  sources  in  areas  of existing
contamination of fishery resources.

          777.0.5.   for discharges  into  saline estuarine waters:   [Subpart
          125.62(c)(4)]

                a.   Does  or will  the current  or modified  discharge cause
                    substantial  differences in  the benthic population within
                    the ZID and  beyond the  ZID?
                6.   Does or will the current  or modified discharge interfere
                    with migratory pathways within the ZID?
                c.   Does or will the current  or modified discharge result in
                    bioaccumulation  of  toxic  pollutants  or pesticides at
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                    levels which  exert  adverse effects on the biota  within
                    the 210?

          Ho  section  301(h)  modified  penult  shall  be  used  where  the
          discharge enters  into stressed saline estuarine waters as  stated
          1n Subpart 12S.59(b)(4).

*** Large and small dischargers must respond.

     The Water Quality Act of  1987  prohibits the Issuance of Section 301(h)
modified  permits for discharges  Into  saline  estuaries with the following
characteristics:

     •    The estuary does not support a balanced Indigenous population
          of shellfish, fish, and wildlife

     •    The estuary does not allow for recreational activities

     •    The  estuary  exhibits ambient water  quality  characteristics
          that  are  not   adequate to  protect  public water  supplies;
          protect shellfish, fish, and wildlife; allow for recreational
          activities; and comply with standards that assure and protect
          such uses.

A Section 301(h) modified permit may not be Issued If the receiving waters
exhibit any of the  foregoing conditions,  regardless of the causes of any of
those conditions.

     Estuaries  are  generally  more  productive  than coastal  areas,  and are
often  more  sensitive  to pollutants.    They   also  serve  as  spawning  and
nursery grounds  for many Invertebrates  and  fishes.   Moreover,  the flushing
characteristics  of  estuaries may be considerably  less  than those of open
coastal areas, especially during periods of reduced freshwater Input.   Thus,
for a given discharge size,  there 1s generally a higher potential Impact In
estuaries than 1n open coastal  environments.
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     Additional  Information  1s  required  for saline estuarlne  discharges.
U.S. EPA regulations [Subpart 125.62(c)(4)] require applicants to demonstrate
that no substantial differences exist between berth1c communities within the
ZIO and beyond the ZID.   Hence, applicants discharging Into saline estuaries
must compare  benthlc  communities  within the ZID and  beyond the ZID boundary
with benthlc  communities  at  reference sites.

     The  applicant should  also  assess  the degree  to  which  the discharge
could Interfere  with  migratory pathways within the  ZID.   In conducting this
assessment, the applicant may calculate the proportion of the cross sectional
area  of  the  estuary  that  Is  Influenced by  the  ZID.    The  potential  for
migratory  Interference may  then be  evaluated by considering  the relative
size and  characteristics  of the discharge-affected  area  and its location in
the estuary with respect  to  known migratory pathways.

     Applicants  with  saline  estuarlne  discharges  must   also   assess  the
bioaccumulatlon  of  toxic   substances  within  the   ZID.    If  elevated  or
Increasing concentrations of toxic substances are found in fish or shellfish,
the  applicant  should assess  the  potential   for  adverse  Impacts such  as
restrictions  on human use (e.g., FDA Action Levels),  Induction of disease, or
Interference  with  fish  and shellfish growth or reproduction (see Tetra Tech
1985a-d;  1987d).

Special Considerations for Small  Dischargers

     When  there is  reasonable concern  that one or more  of  the foregoing
conditions  has come  Into existence  during  the term  of the  existing Sec-
tion 30I(h) modified permit, the Regions should require small applicants with
discharges  Into saline estuaries to demonstrate successfully  that  none of
the foregoing conditions  exist.   To do so, small applicants may  be required
to perform a detailed  biological survey  similar to that  required of large
dischargers.    Small   applicants  are  advised  to  consult the   Information
provided under Questions  II.C.I and  III.D.I  (above) and in  Section III.F for
guidance  on  the design and  execution of  detailed  biological  surveys.  The
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Regions should notify applicants well In advance of the application deadline
                                                                     •
If a demonstration Is required to document the absence of stressed conditions
1n the receiving environment.                      -                  ,

          III.D.6.    For Improved  discharges,  will  the proposed  improved
          discharge(s)  comply with  the  requirements of Subparts 125.62(a)
          through 125.62(d)?  [Subpart 125.62(e)J

*** large and small dischargers must respond.

     U.S. EPA regulations require  applicants who propose discharge Improve-
ments to  demonstrate that the  Improvements  will result 1n  compliance with
Subparts  125.62(a)   through  125.62(d).   This  demonstration  might be  ac-
complished  by  comparing conditions at the outfall  location  with conditions
near  discharges  that  are   similar  to  the proposed  Improved  discharge.
Assuming  that  there  1s  a  basic  similarity   In  Indigenous  biota of  the
receiving  environment,  such  a comparison  may  be  sufficient   to  predict
protection  of  a BIP.   Applicants  may  also conduct  predictive  analyses of
effluent  dispersion  and seabed  accumulation of  sol Ids  following discharge
Improvements.

     Applicants whose discharge Improvement plans Include outfall relocation
should  describe existing  biological conditions  at  both  the proposed  and
existing  outfall  sites.     Those  applicants  are  also  to  predict  future
biological  conditions  at  the  proposed site   following relocation of  the
outfall.   Such  predictions  might  be conducted  by  comparisons  with  other
discharges  that  are  similar to the  relocated  discharge.    Discharges used
for such comparisons  should  be located  In receiving environments similar to
the applicant's.

          III.D.7.   For altered dlscharge(s), will the altered dlscharge(s)
          comply  with   the   requirements   of   Subparts   125.62(a)  through
          125.62(d)?  [Subpart 125.62(e)J
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    Large and small dischargers oust respond.

     Applicants  that request modifications  for altered discharges may  use
predictive  methods  similar  to  those  described  for Improved  discharges.
However,  such  applicants  must  demonstrate  that  the Increased  pollutant
loading that will  result from population growth or Industrial  growth  within
the  service area  will  still enable compliance  with  Subpart 126.62(a)-(d).
These predictions  of compliance with 301(h)  criteria  during the 5-yr  permit
term may be technically  difficult, and may require extensive analyses.

          III.D.8.   If your current discharge  Is  to  stressed  ocean waters,
  -        does  or will your  current  or  modified  discharge:   [Subpart
          125.62(f)J

               a.   Contribute  to,  increase,  or  perpetuate  such  stressed
                    condition?
               6.   Contribute  to further degradation of the biota or water
                    quality if the  level  of human perturbation from other
                    sources increases?
               c.   Retard  the recovery of the biota or water quality if
                    human perturbation from other sources decreases?

*** Large and small dischargers must respond.

     When  it appears  that  art  applicant's receiving  waters are or  may be
stressed, the Region may require the applicant to demonstrate the presence or
absence  of stressed  conditions.   If stressed  conditions  exit,  the areal
extent  and  magnitude of  those  stresses  should  be  documented.    Because
stressed water determinations are largely based on biological  conditions in
the  receiving environment, applicants  may  be  required  by the  Regions to
perform  detailed  biological   surveys.    Applicants  required  to  perform
detailed biological  surveys for the purpose of  determining whether stressed
waters  exist  1n the  receiving  environment should consult  Section  III.F of
this document  and guidance documents  cited therein  for  information  on the
design and execution  of  those surveys.   The Regions should notify applicants
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 well  1n  advance of the  application deadline  If  surveys of  the b\ota are
 required to  determine whether  stressed  conditions exist  1n  the receiving
 environment.    Moreover,  the  Regions  should  work  closely  with applicants
 during   all  phases  of the  required  studies  to  ensure the  collection  of
 adequate,  high quality data.

    *7IJ.£.     Impacts of  Discharge  on  Recreational  Activities   fSuboart
      125.62(d)l

      It Is necessary to ensure that a 301(h) modified  discharge  will  1)  meet
'water quality standards relevant to recreational activities beyond  the  ZID,
 and 2)  will not cause legal restrictions on activities  that would be lifted
 or modified by upgrading  the  applicant's  POTW  to secondary treatment.

           III.E.I.     Describe   the  existing  or  potential   recreational
           activities  likely  to  be affected  by the  modified  discharge(s)
           beyond the zone of  initial dilution.

 *** Large and small  dischargers must respond.

      The  Impact of  POTW  discharges  on  recreational  activities  must  be
 assessed.   Recreational fisheries are considered 1n the biological evaluation
 section.  Other activities Involving  contact  with water may  be affected  by
 mlcroblal  contamination.  For recreational  Impact  assessment,  dispersion and
 transport  of  the  effluent  needs  to be considered  in conjunction with  the
 applicant's disinfection  procedures.

      All recreational  activities currently occurring within the bay,  estuary,
 or an  8-km  radius  of the  outfall  should  be  identified  (e.g., swimming,
 boating, fishing,  shellfishing,  underwater  diving,  picnicking,  other beach
 activities).   Any  additional  potential  future  recreational  activities should
 also  be  Identified  (e.g.,  new ports,,  boat   harbors).    A  map should  be
 provided that indicates the location of existing activities,  along  with  the
 location of  the existing or proposed outfall.   Qualitative or,   whenever
 possible,  quantitative Information should  be  provided  that  indicates  the
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extent of  the existing activities.  This could  Include the number of boats
or  boat  slips  In the  area,  species  of  fish and shellfish  recreatlonally
harvested, size of catch, and number of beach user days.

          III.E.2.   Hhat  are  the existing  and potential  Impacts  of  the
          modified  dlscharge(s)  on recreational  activities?  Your  answer
          should  Include,  but  not be Halted  to,  a discussion  of fecal
          coUform bacteria.

*** Large and small dischargers must respond.

     Water quality  standards  for protecting recreational  uses,  particularly
coUform  bacteria  or  enterococcl  standards,  should  be  provided.   Water
classifications  within 8  km  of  the  discharge  should be  Indicated.    The
schedule and  frequency of chlorination  should be established.   To  confirm
compliance with  standards  relevant to recreational  activities,  any  required
coUform or  enterococcl bacteria  monitoring  data  for the effluent, at  the
ZID boundary,  and on the adjacent shoreline  should  be submitted.   As noted
1n Section III.F.2,  bacteriological sampling  should  be limited  to the night
or  early morning  hours.    If  shoreline  areas are not normally monitored,
sampling should  occur  on the  shore near popular water-activity areas.   If
noncompl 1 ance with  coUform  bacteria  standards Is  noted,  an  explanation  and
corrective measures  should be  provided.   Other sources of coUform  bacteria
present  In the  area that could be contributing to  the  problem should  be
Identified.

          IJI.E.3.   Are there any Federal, State, or local  restrictions  on
          recreational  activities in  the vicinity of the modified  dischar-
          ge(s)?  If yes, describe the restrictions and provide citations to
          available references.

*** Large and small dischargers must respond.

     Any federal,  state,  or local  restrictions  or closures  relating  to  the
discharge  and  recreational  activities should  be identified.  The nature  of
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restrictions, the date  Implemented,  and  the  agency  responsible  (e.g.,  state
department of health) should be Indicated.

          III.£.4.   If  recreational  restrictions exist,  would such restric-
          tions be  lifted or modified  if you were discharging  a  secondary
          treatment effluent?

*** Large and small dischargers must respond.

     If restrictions  are In place,  the  relation of the  restriction  to the
current or modified discharge quantity and quality should be established.  If
an  Improvement 1n  the  discharge quality would  modify  or  eliminate  the
restriction  on  recreational  activities,  this  should  be Indicated.   In all
such  events,  1t  should  be  determined   whether  secondary treatment  would
Improve the discharge sufficiently to allow the restriction to be modified.

     III.F.  Establishment of a Monitoring Program fSuboart 125.631

     Establishment  of a monitoring  program  for  applicants granted Section
301(h) modified discharge permits Is Important to evaluate the impact of the
modified discharge on selected marine biological communities,  to demonstrate
continued compliance with applicable water quality standards,  and to monitor
effectiveness of  the urban pretreatment  and toxics control programs.   Only
those scientific  Investigations  that are necessary to  study  the effects of
the proposed discharge  should  be Included  in the scope  of  the monitoring
program  [Subpart  125.63(a)(l)(i)(B)].   Unless  special  circumstances  exist
(e.g., the  presence  of  distinctive  habitats,  high  mass emission  rates of
toxic substances),  monitoring programs  for  small  dischargers are typically
much less comprehensive than those for large discharges.

     The  monitoring  program  consists of three  parts:    biological,  water
quality,  and  effluent.   Although each .of these  parts  involves  sampling at
different  locations  and  for  different  variables,   they  should  not  be
considered as  Independent  activities,  but as  an  integrated study.   In this
manner,  the  applicant will be  able to meet specific objectives of each part
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of the study while also conducting a meaningful assessment of Impacts of the
discharge.  Moreover, as predictable relationships are established among the
biological, water quality, and effluent monitoring variables,  It  should be
possible to delete certain elements of the field monitoring studies.

     The  continued assessment  of marine  biota as part  of the  monitoring
program Involves  the  same  type  of comparative strategy as is required for a
BIP  demonstration  in the  application.   The  characteristics of  selected
marine  communities in the  discharge vicinity are compared  with  biological
characteristics  at reference areas.   Hence,  a primary  objective of  the
biological monitoring program 1s to evaluate continued compliance  with the
BIP  requirements.   This  demonstration can  be accomplished  by  conducting
periodic (e.g., quarterly) seasonal surveys of biological  communities.

     Biological  communities  selected  for study  in  the  monitoring program
should  Include  those communities  that  are most  likely affected by  the
discharge.   As  1s the case  for  BIP demonstrations in the  original  appli-
cation,  the monitoring  program  should address  any  biological  effects in
terms  of spatial  extent,  magnitude,  potential  for secondary  impacts,  and
potential  for  involvement  of commercial  or  recreational  species.    All of
these  factors  will be  Important In  determining whether or not  detectable
differences in biological characteristics are adverse.

     Bioaccumulatlon  determinations  and  sediment  sampling  are  used  to
evaluate  biological  effects of  toxic  substances  in  the  effluent.    The
results of  these studies can Indicate  the  potential  for  adverse effects on
human   health,   especially  if  recreationally  or  commercially   important
fishery resources occurred in the outfall  vicinity.   These results may  also
be used to determine the  need for additional  (or  fewer)  analyses of toxic
substances in sediments or  in organisms exposed to the diluted effluent.

     The water quality monitoring program Is  intended to evaluate compliance
with  applicable  water quality  standards and criteria,  and to  measure the
presence of toxic substances.  An additional objective of the water quality
monitoring  program  is  to  provide information  that  will  supplement  the
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biological  monitoring program,  In particular  to  assist  In the  Interpre-
tation of observed biological differences.

     Monitoring  POTW  effluent  1s  Important  for  providing  supplementary
Information  for  both the water  quality and biological programs.   Effluent
monitoring   data are also used  for demonstrating continued  compliance with
the  modified permit  effluent  limitations and  as  a data source  for permit
renewal applications.

          III.F.I.   Describe  the biological,  water  quality,  and effluent
          monitoring  programs which  you propose  to  meet  the criteria  of
          Part 125.63.    Only   those  scientific  investigations  that  are
          necessary to study the effects of the proposed discharge should be
          included in the scope  of the monitoring program [Subpart 125.63(a)
***
    Large and small dischargers must respond.
     The  extent of  the monitoring  program required  as  part of  a Section
301(h)  variance will depend upon  the characteristics of the  discharge and
the receiving  environment.   Monitoring of  the  effluent  and  receiving water
may also  be  required as part of the applicant's existing NPDES permit or to
meet state regulations.  The applicant's proposed monitoring program must be
submitted with  the Section 301(h) application.

     Detailed  guidance  on the design  of  Section  301(h)  monitoring programs
is provided  1n Design of 301(h) Monitoring Programs for Municipal Uastewater
Discharges  to   Marine  Water  (Tetra  Tech  1982a)  and  Framework for  301(h)
Monitoring Program  (Tetra Tech  1987e).  Although  some technical  Information
(primarily literature  citations,  analytical protocols, and  legal  citations
and requirements) provided  in  Tetra Tech  (1982a) has  been  superceded, most
of the  information   is  still  valid  and  applicable  to the design  of  301(h)
monitoring programs.   More  recent documents (e.g.,  Tetra Tech 1985e, 1986,
1987c,  1987e)  include the addition  of recent  literature  citations, updated
analytical protocols,  and  updated  legal  citations  and  requirements.   The
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updated  Information  1n  these more  recent  documents,  together  with  the
earlier  guidance provided  by  Tetra Tech  (1982a,  1987e),  1s  sufficient  to
design  and  Implement  an  effective  monitoring  program.    Applicants  are
referred to  the following  documents  for additional or updated  guidance  on
specific topics relevant to the  design and execution of  301(h) monitoring
programs:

     •    Tetra Tech   (1987a,  1988)  for  Information  on  positioning
          methods In nearshore marine and estuarine waters

     •    Tetra Tech  (1985c,d,e,  1986) for information on  analytical
          methods

     •    Tetra Tech  (1987c)   for Information  on quality  assurance/
          quality control procedures for field and laboratory methods

     •    Tetra Tech   (1985a,b,c,d,  1987d)  for  Information  on  bio-
          accumulation  monitoring  studies

     •    Tetra Tech (1987b)  for Information on  fish  liver pathology
          monitoring studies.

Biological Monitoring

     The  applicant's   biological  monitoring   program  must   Include  the
following elements to the extent  practicable:

     1.   Periodic surveys  of control   sites and biological communities
          most  likely to be affected by the discharge

     2.   Periodic bloaccumulatlon studies and examination of possible
          adverse effects of effluent-related toxic substances
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     3.   Periodic sampling of sediments

     4.   Periodic assessment  of commercial or  recreational  fisheries
          (If present).

Small applicants  are  not subject to Items  2 through  4  Immediately above If
they discharge at depths greater than  10  m, and If they demonstrate through
a suspended sol Ids deposition  analysis  that there  will  be  negligible seabed
accumulation In the vicinity of the modified discharge.

     The objectives of the biological monitoring program are to evaluate the
Impact of the modified discharge and to demonstrate compliance with Section
301(h)  biological  requirements.   Thus,  the  biological monitoring  program
must enable the same spatial comparisons (I.e., ZID, ZID boundary, discharge
Impact area, and control) as are required for demonstration of a BIP.

     The  applicant's  monitoring program  should  Include  only those  study
elements  that  are practicable and  appropriate   1n  the  receiving  water
environment.   When  the applicant  considers that one or more  of  the afore-
mentioned study elements  1s not practicable,  a justification for the proposed
deletion  from the  monitoring  program should  be  provided.    Examples  of
situations  1n  which  reductions in  the frequency  or extent  of  biological
surveys would be  reasonable might  include conditions  of high  current speeds
or  adverse  climatic  periods   (sampling not practical)   and  periods of low
biological  variability or extremely low  productivity  (sampling  not appro-
priate).

     Monitoring  program  specifications  supplied  by  the  applicant  must
include the following  Information:

     •    Biological  groups to be sampled

     •    Sampling methods

     •    Station locations
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     •    Sampling schedules

     •    Preservation techniques

     •    Analytical techniques

     •    Quality assurance/quality control procedures

     •    Statistical analyses

     •    Taxonomlc sources.

     The three types of  sampling stations that should generally be  Included
1n the periodic  biological  surveys to the extent practicable are located as
follows:

     •    In the vicinity of the ZID

     •    In other areas of potential discharge  Impact

     •    In control (I.e., reference) areas.

Monitoring  at  sites Intermediate  between  control  and outfall  locations  may
be  necessary,  especially  for  large discharges  where  definition  of  the
spatial  extent   of  biological   effects  is  an  important  consideration.
Additional  station requirements  would also  be associated  with discharges
into estuaries  (within-ZID  station),  into stressed waters,  or in situations
where other pollutant sources  potentially  affect biological communities near
the  discharge.    For  modified  discharges  involving outfall  relocation,
monitoring must  be  conducted  at the existing discharge site until cessation
of that discharge, and at the  relocation  site.

     Selection of  control  stations is one of the more important aspects of
monitoring  program  design,  as BIP comparisons  will  rely  on data from these
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sites.  Control  statlon(s)  should  be  located  in areas not Influenced by the
applicant's  previous  or existing discharge  or other  pollutant  sources.
Sediment characteristics at the control  station(s) should be similar to those
expected to occur naturally 1n the vicinity of the discharge.   Discharge and
control stations should be located at similar water depths.

     B1oaccumulat1on  studies  are  to  be Included in  the  monitoring program
to evaluate  the potential  adverse effects of toxic  substances.    In situ
bloassays  may  be  needed on  a case-by-case basis.   Caged  specimens  of
bivalve molluscs  (e.g.,  Mytllus edulls  or H.  californianus)  are recommended
as test organisms for In situ  bloassays.   Exposures should  be conducted in
the  discharge vicinity  and  at an appropriate reference  site.   Additional
exposure  sites  may  be  necessary for  Urge dischargers,  especially  in
situations where  other  pollutant sources  contribute toxic substances to the
receiving water body.  Only those toxic pollutants and pesticides Identified
in the applicant's discharge need to be measured in the exposed organisms.

     The monitoring program must  also  include sediment  sampling  for toxic
substances  in the  vicinity of  the  discharge,  in  other  areas  of expected
solids  accumulation,  and  at  appropriate  reference  sites.     VHthin-ZID
sampling should  be  undertaken  where practicable.   The sediment  sampling is
Intended  to  provide  an  indication  of  the  toxics  accumulation  within
sediments near the discharge and the associated contamination potential.  If
elevated or  Increasing  concentrations of  toxic substances are  detected, the
applicant must  also  analyze  tissue  concentrations of toxic  substances in
Indigenous organisms  to determine  whether adverse bioaccumulation is occur-
ring.   Recommended organisms  for such  analyses  Include demersal  fishes
(e.g., flounder or  sole), epibenthic  megainvertebrates (e.g.,  crabs or lob-
ster) or sessile filter-feeding organisms  (e.g.,  clams, mussels, or oysters).
                                       •

     Sediment  samples  should   also  be  analyzed  for characteristics  that
would  support the water  quality and biological  surveys.  These  variables
should include particle  size distribution and total volatile  solids.  Other
variables such as 6005,  sulfides,  and total organic carbon,  are also useful
and may be required by some states.
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     If recreational or commercial fisheries are present  In areas potentially
affected  by  the  discharge,  the  applicant must  also periodically assess those
fisheries.   The  kinds of evaluations conducted will  depend on the nature of
the  local  fisheries and on the level of detail  in available fisheries data.
These  evaluations  must reflect an understanding of the potential  Impacts of
the  discharge on  the  fisheries.   Sources  of  Information  used to determine
the  productivity  and  status of  fisheries  Include  state resource agencies,
voluntary logbooks, Interviews,  and field observations.  The periodic and
level  of  effort  of fishery  surveys will depend upon the  size and location of
the  discharge, concentrations  of toxic  substances  In the effluent, species
harvested, and the Importance of  the commercial  or recreational fishery.

Water  Quality Monitoring

     The  objectives of the  water quality  monitoring  program are  to provide
data for  determining compliance with applicable water quality standards and
criteria,  to measure  the  presence  of toxics  identified or  expected in the
effluent,  and to assist  in  the  evaluation  of biological  data.

     The  water  quality  measurements  usually  required  Include  dissolved
oxygen,   BODs,   suspended   sol Ids,   pH,  temperature,  salinity,  and  light
transmittance.   Light transmittance  standards may  be specified In terms of
turbidity,   Secchi  disc  depth,  extinction coefficient,  or  percent  light
transmittance.    With  the   exception of  Secchi disc  depth,  water column
profiles  should be determined for  these  variables.   However,  because the
Secchi disc  provides  cumulative data on water  transparency measured  from the
surface down to  the depth  at which  it disappears from sight,  the Secchi disc
should not  be  used  to detect  the  effect of  a submerged   plume  on light
transmittance.

     Other variables that may be  required include nitrogen  (nitrate,  nitrite,
total  Kjeldahl nitrogen,  and ammonia), total  and reactive phosphorus, toxic
substances identified  in the effluent, chlorophyll a,  floating participates,
color,  settleable   solids,   surface oil and grease,  total and  fecal  coliform
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bacteria, and  enterococd  bacteria.   Samples for these variables  should be
collected 1.0  n (3.3 ft)  below  the  water surface,  at mid-depth,  and  1.0 m
(3.3  ft)  above  the  bottom.   In deep water,  sampling at additional  water
column depths  may be required.   The applicant's monitoring  program should
specify  the variables  for which profiles  are  to be  taken  along with  the
sampling Interval.

     For. existing  discharges, stations  should  be located in  the  following
areas:

     •    ZID boundaries (both upcurrent and downcurrent)

     •    Control (I.e., background) stations along the primary axis of
          the  longshore component of  the current (both  upcurrent and
          downcurrent)

     •    Intermediate  upcurrent  stations  located  between  the  ZIO
          boundary and the upcurrent control station

     •    Potential  Impact  areas  (e.g.,   In  the nearshore  zone  and
          close to areas with distinctive habitats).

The  applicant  should  use  Information  on  local currents  and  wastefield
dispersion patterns when selecting sampling station locations  In potentially
impacted areas.    Sampling stations  located  at  the  ZID  boundary,  control
stations, and Intermediate upcurrent stations should be in approximately the
same  depth  of  water.   Control   stations  should  be  located  in  areas  not
influenced  by the  discharge.   Intermediate upcurrent  stations  should be
selected to represent  the  approximate  residual wastefield concentrations
upcurrent of the location, thereby accounting for potential recirculation of
previously discharged  effluent (by reversing tidal  currents,  upwelling, or
stagnant net circulation).  Data should be collected at the intermediate and
ZID  stations  at  least  twice  daily  (e.g., high  and  low slack tides),  to
evaluate short-term  conditions.   The  duration  of the longshore current in
relation to the  time  of  sampling  is  an  important  factor  in  determining
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whether the Intermediate  upcurrent  stations are representative of persistent
conditions or  of only a temporary plume reversal .   For discharges Involving
outfall  relocation,  monitoring  stations  must be  located  at the  current
discharge site until  cessation  of the discharge, and at the relocation site.

     For  all  cases,  the  applicant should  Include  a chart showing  the
location of  the outfall,  the shoreline, any distinctive habitats,  and all
sampling  stations.   The  latitude,  longitude,  and  depths  of  the  stations
should be specified.

     Sampling  frequencies should be selected to comply with state require-
ments  and  to  provide data for critical periods.    In  most  cases, quarterly
surveys that Include  the  critical periods (e.g., time of maximum stratifica-
tion)  should meet  state  requirements.    More frequent  sampling  (e.g.,  for
coliform bacteria)  in swimming  or shellfish harvesting  areas may be required
by some states.  The analytical  methods  and  quality control /quality assurance
procedures should be  described  (see Section  III.F.2  for  additional guidance).

Effluent Monitoring

     The major objectives of treatment  plant monitoring are to provide data
for  determining  compliance  with  permit  effluent  limitations  and  state
requirements,  to measure  the effectiveness of the  toxic  substance control
program,  and  to relate  discharge  characteristics  to  the  receiving water
biological and water  quality  conditions.  In  add 111 on,  influent and effluent
monitoring provide  data for assessment  of treatment plant performance, which
may be required  to  meet modified  discharge  permit conditions.
     Variables  that  should be  measured  in  the effluent  are  flow,
suspended  solids,  pH,  dissolved  oxygen,  and  the  toxic   pollutants  and
pesticides  present or  likely to  be present  in  the discharge.   The toxic
pollutants and  pesticides that should be measured are specified in Subparts
125.58(z) and  (o)  of the Section 301(h) regulations.  Additional variables,
which may  be required  by other permit  conditions,  include  grease and oil,
                                     112

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settleable  solids,  nutrients,  total  and  fecal  col 1 form  bacteria,  and
temperature.

     Influent, samples  for conventional pollutant and  nutrient  analyses,  1f
required, should be collected  just downstream  of any coarse screens or grit
chambers.  Effluent samples  should be collected  downstream of any chlor1 na-
tion  or disinfection  units.   Effluent  samples to  be analyzed  for toxic
substances should  be  collected just  upstream  of the  outfall.   In general,
grab  samples  should   be  collected  for  pH  and  total  and fecal  coll form
bacteria.   For the other conventional  pollutants  (e.g.,  suspended solids),
24-h flow composite samples are recommended.

          III.F.2.     Describe  the   sampling  techniques,  schedules,  and
          locations, analytical techniques, quality control, and verification
          procedures to be used.

*** Large and small dischargers must respond.

     The  following Information must  be  provided  for  all  portions  of the
proposed monitoring program:

     •    Variables to be measured

     •    Sampling methods

     •    Sampling schedule

     •    Sampling locations

     •    Analytical techniques

     •    Quality control and verification procedures.

     Guidance on the  above  subjects   is provided  In the documents listed In
Section  III.F.I.   Current U.S. EPA-approved methods  should be  used for all
                                    113

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variables.  Additional  guidance on navigational  requirements  Is provided  In
Appendix D.

          III.F.3.  Describe the personnel and financial resources  available
          to  implement  the monitoring programs upon issuance of a  modified
          permit and  to carry it out for the life of the modified permit.
                               _ t
*** Large and small dischargers must respond.

     The  applicant  must  provide  Information  on   available  personnel,
facilities,  and financial  resources to  show  that  the  proposed monitoring
program  can  be Implemented  and  continued  for  the  tern  of the  modified
discharge permit if  a  Section 301(h)  variance  Is  granted.  The  applicant
should  review  state  monitoring  requirements  to ensure that the  proposed
program meets those requirements.

     III.G.   Effect of Discharge  on Other Point  and Honooint Sources Wart
     125.641

          III.G.I.   Does (will) your modified discharge(s)  cause additional
          treatment  or  control  requirements  for  any other point or nonpoint
          pollution source(s)?

*** Large and small dischargers must respond.

     The  Section  301(h)  regulations  require  an  analysis  of  whether  a
decreased treatment level at the  applicant's  discharge would require other
pollution  sources   in  the vicinity  to Increase  their treatment   levels  or
apply  other  additional  controls.   For  open coastal  waters,  a list  of
discharges  within  the  anticipated impact area of  the applicant's modified
discharge should be provided.  The  subsequent dilution at  each outfall  can
be estimated using Table  B-5  in Chapter.B-IV of Appendix B of this  document.
The total dilution  is the product  of the  initial dilution and the  subsequent
dilution.   If  the effect  of the applicant's discharge is  small   at other
sources,  further analysis  may not  be needed.   Otherwise,  an analysis  of
                                     114

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 compliance with water  quality standards  at  the other  discharger sites  is
                                                                    •
 appropriate for  determining  the  effects  of  the  applicant's  discharge  at
 these sites. For  most  small POTW discharges,  the  effects on other  sources
•should be negligible.

      In  estuaries where  outfalls  are  close   together,  effects  on  other
 sources are possible.  The  approach outlined  above can be used to estimate
 total dilution  at  the other  outfalls.

           III.G.2.  Provide the determination required by Subpart 125.64(b)
           or,  if  the determination  has not yet been received,  a copy  of a
           letter  to the appropriate  agency(s)  requesting  the required
           determination.

 *** Large and small dischargers must respond.

      The applicant must provide a copy of  a determination from  the state or
 Interstate agencies that  are  authorized to establish wasteload  allocations
 Indicating whether the proposed discharge  will  result In the Imposition of
 additional pollution control  requirements  on  any  other  point or nonpoint
 sources.  This  determination must  also explain  the  basis  of the  conclusions.

      If the required determination has not been received when  the application
 1s  submitted to U.S.  EPA,  the  applicant should  Include copies of the  request
 letters to the  appropriate agencies.  When the  determination  Is  made, a copy
 of  the determination letter  should be forwarded to  U.S.  EPA.

      III.H.  Toxics Control  Program fPart 125.661

      The toxics control program is  designed to  identify and  assure  control
 of  toxic  pollutants and  pesticides discharged  to the  POTU.   The  Section
 301(h) toxic control regulations  require both  industrial and  nonindustrial
 source control   programs.    However, the  control of  industrial   sources  is
 addressed separately by pretreatment program regulations  [Subpart 403.8(d)]
 that  require all  industrial  pretreatment  programs to have been approved by 1
                                     115

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July  1983.   Applicants  must nonetheless adhere to the  Section  403  program
requirements and compliance  schedules.

     U.S. EPA's  Section 301(h) toxics control  program regulations apply to
all  applicants.    However,  small  applicants  who  certify that there  are no
known or suspected sources of toxic pollutants and pesticides to the POTVf are
relieved of most of the  cost burden for  toxics control program development.

          111.H.I.    a.    Do  you have  any  known  or suspected Industrial
          sources of  toxic pollutants or pesticides?

          b.     If  no,   provide  the  certification  required  by  Subpart
          125.66(a)(2).

          c.   If yes, provide the  results  of wet-  and dry-weather effluent
          analyses for toxic pollutants  and pesticides.

          d.   Provide an analysis of known or suspected industrial  sources
          of toxic pollutants  and pesticides  identified  in III.H.l.c above.

*** Large dischargers must respond to parts a  through d.

*** Small dischargers must  respond to parts a and b  in  full, and to parts c
and d to the extent practicable.

     Toxic pollutants and pesticides  are defined in Subparts 125.58(aa) and
125.58(p),  respectively, and  include those  substances  listed  in Table 2.
Marine  water  quality criteria   are  summarized in  Table 3.    Guidance on
sampling and analytical  methods  1s found in Tetra Tech  (1982a,  1987c,e) and
40 CFR Part 136.

     If  there  are  no  known  or  suspected  industrial sources  of  toxic
pollutants or pesticides, the  applicant  must  certify  this fact,  based on the
results  of  an  industrial user  survey.   This survey must  be  conducted as
described in 40 CFR 403.8(f)(2).
                                    116

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                 TABLE 2.  TOXIC POLLUTANTS AND PESTICIDES
                 AS DEFINED IN SECTION 125.58 (aa) and (p)
          Demeton
          Guthion
          Malathion
                                 Pesticides
         Methoxychlor
         Mi rex .
         Parathion
                              Toxic  Pollutants
 1. Acenaphthene
 2. Acrolein
 3. Acrylonitrile
 4. Aldrin/dieldrin
 5. Antimony and compounds3
 6. Arsenic and compounds
 7. Asbestos
 8. Benzene
 9. Benzidine
10. Beryllium and compounds
11. Cadmium and compounds
12. Carbon tetrachloride
13. Chlordane (technical mixture and
    metabolites)
14. Chlorinated benzenes (other than
    dichlorobenzenes)
15. Chlorinated ethanes (including
    1,2-dichloroethane, 1,1,1-
    trichloroethane, and hexa-
    chlnroethane)
16. Chloroalkyl  ethers (chloroethyl
    and mixed ethers)
17. Chlorinated naphthalene
18. Chlorinated phenols (other than
    those listed elsewhere;
    includes trichlorophenols and
    chlorinated cresols)
19. Chloroform
20. 2-Chlorophenol
21. Chromium and compounds
22. Copper and compounds
23. Cyanides
24. DDT and metabolites
25. Dichlorobenzenes (1,2-, 1,3-,
    and 1,4-dichlorobenzenes)
26. Dichorobenzidine
27. Dichloroethylenes (1,1-and 1,2-
    dichloroethylene)
28. 2,4-Dichlorophenol
29. Dichlorophropane and dichloro-
    propene
30. 2,4-Dimethylphenol
31. Dinitrotoluene
32. Diphenylhydrazine
                                    117

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TABLE 2.  (Continued)
33. Endosulfan and metabolites           47.
34. Endrin and metabolites.        .      48.
35. Ethyl benzene                         49.
36. Fluoranthene
37. Haloethers (other than those         50.
    listed elsewhere; Includes           51.
    chlorophenylphenyl ethers,           52.
    bromophenylphenylether,              53.
    bis(d1chloro1sopropyl) ether,        54.
    bls-(chloroethoxy) methane, and      55.
    polychlorinated diphenyl ethers)
38. Halomethanes  (other than those
    listed elsewhere; Includes
    methylene chloride, methyl-
    chloride, methyl bromide,             56.
    bromoform, and dichlorobromo-        57.
    methane)                             58.
39. Heptachlor and metabolites
40. Hexachlorobutadiene                  59.
41. Hexachlorocyclohexane                60.
42. Hexachlorocyclopentadiene            61.
43. Isophorone                           62.
44. Lead and compounds                   63.
45. Mercury and compounds                64.
46. Naphthalene                          65.
Nickel  and compounds
Nitrobenzene
Nitrophenols  (including  2,4-
dinitrophenol,  dinitrocresol)
Nitrosamines
Pentachlorophenol
Phenol
Phthalate esters
Polychlorinated biphenyls (PCBs)
Polynuclear aromatic  hydro-
carbons (including benzanthra-
cenes,  benzopyrenes,  benzofluor-
anthene,  chrysenes, dibenzanth-
racenes,  and indenopyrenes)
Selenium and compounds
Silver and compounds
2,3,7,8-Tetrachlorodibenzo-p-
dioxin (TCDD)
Tetrachloroethylene
Thai 1 i um and compounds
Toluene
Toxaphene
Trichloroethylene
Vinyl  chloride
Zinc and compounds
a The term "compounds"  includes  both organic and inorganic compounds.
                                    118

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STABLE 3.  SUMMARY OF U.S. EPA MARINE WATER QUALITY CRITERIA

Concentrations (ua/L)
Pollutant
Acenaphthene
Acrolein
Acrylonitrile
Aldrin
Antimony
Arsenic
Pentavalent
Trivalent
Asbestos
Benzene
Benzidine
Beryllium
Cadmium
Carbon tetrachloride
Chlordane
Chlorinated benzenes
Chlorinated ethanes
Dichloroethane 1,2
Hexachloroethane
Pentachl oroethane
Tetrachloroethane 1,1,2,2
Trichl oroethane 1,1,1
Chlorinated ethyl enes
Dichloroethylenes
Tetrachl oroethyl ene
Trichl oroethylene
Acute
970a
55a
b
1.3C
b
2,319a
69d
b
5,100a
b
b
43<1
50,000a
0.09C
160a
113,000a
940a
390a
9,020a
31,200a
224,000a
10,200d
2,000a
Chronic
710a
b
b
b
b
13a
36e
b
700a
b
b
9.3e
b
0.004f
129a
b
b
281 a
b
b
224,000a
450a
b
References
(see below)
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
                             119

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TABLE 3.  (Continued)

Concentrations (ua/L)
Pollutant
Chlorinated naphthalene
Chlorinated phenols
Chlorophenol 2
Chlorophenol 4
Pentachlorophenol (penta)
Tetrachlorophenol 2,3,5,6
Chlorine
Chloroalkyl ethers
Chloroethyl ether
Chloroform
Chlorpyrifos
Chromium
Hexavalent
Trivalent
Copper
Cyanide
DDT
DDT Metal bolites
ODD (TDE)
DDE
Demeton
Dichlorobenzenes
Dichlorobenzidines
Di Chlorophenol 2,4
Dichloropropanes
Dichloropropenes
Acute
7.5a
b
29,700*
13d
440a
13d
b
b
b
0.011d
l,100d
10,300a
2.9d
1.0d
0.13C
3.6a
14a
b
l,970a
b
b
10,300a.
790a
Chronic
b
b
b
7 ge
7>9b
7.5e
b
b
b
0.00566
5oeb
2.9e
1.0e
0.001f
b
b
0.1
b
b
b
3,040a
b
References
(see below)
Goldbook
Goldbook
Goldbook
Update No. 2
Goldbook

Goldbook
Goldbook
Goldbook
Update No. 2
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
                                    120

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TABLE 3.  (Continued)

Concentrations (ua/U
Pollutant
Dieldrin
Dimethyl phenol 2,4
Dlnltrotoluene
Dloxln (2,3,7,8-TCDD)
Diphenylhydrazine 1,2
Endosul fan
Endrln
Ethyl benzene
Fluoranthene
Guthion
Haloethers
Halomethanes
Heptachlor
Hexachlorobutadiene
Hexachlorocyclohexane (HCH)
Lindane (gamma -HCH)
HCH (mixture of isomers)
Hexachl orocycl opentadi ene
Isophorone
Lead
Malathion
Mercury
Acute
0.71C
b
590a
b
b
0.034C
0.037C
430a
40a
b
b
12,000a
0.053C
32a
0.16C
0.34a
7.0a
12,900a
140d
b
2.1d
Chronic
0.0019f
b
370a
b
b
0.0087f
0.0023f
a
16a
0.01
b
6,400a
0.0036f
b
b
b
b
b
5.6e
0.1
0.0256
References
(see below)
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
                                    121

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TABLE 3.  (Continued)

Concentrations fua/D
Pollutant
Methoxychlor
M1rex
Naphthalene
Nickel
Nitrobenzene
Nitrophenols
Nitrosamines 3
Parathlon
Phenol
Phosphorous (elemental)
Phthalate esters
Polychlorlnated blphenyls
Polynuclear aromatic
hydrocarbons
Selenium (Inorganic selenlte)
Silver
Sulfur (hydrogen sulfide, H2S)
Thallium
Toluene
Toxaphene
Vinyl chloride
Zinc
Acute
b
b
2,350a
75C
6,680a
4,850a
,300,000a
b
5,800a
b
2,944a
10a
300a
410C
2.3*
b
2,130a
6,300a
0.21d
b
95d
Chronic
0.03
0.001
b
8.3'
b
b
b
b
b
0.1
3.4*
0.03f
b
54*
b
2*
b
5,000a
0.00026
b
866
References
(see below)
Goldbook
Goldbook
Goldbook
Update No. 2
Goldbook
Goldbook
Goldbook
Update No. 2
Goldbook

Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Goldbook
Update No. 2
Goldbook
Update No. 2
                                    122

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TABLE 3.  (Continued)
a  Data Insufficient  to derive  criteria.   Value presented  is the  lowest
observed  effect  level   (LOEL).    These  concentrations  represent  apparent
threshold levels for acute and/or chronic toxic effects,  and are intended to
convey  information about  the  degree  of toxicity  of a  pollutant in  the
absence of established criteria.

b Criterion has not been established for marine water quality.

c Not to be exceeded at any time.

d Maximum 1-h average.   Not  to  be exceeded more than once every 3 yr on the
average.

e Maximum  96-h  (4-day)  average.   Not  to  be  exceeded more than  once  every
3 yr.

f Maximum 24-h average.  Not to be exceeded more than once every 3 yr.

References:  Goldbook-U.S.  EPA 1986a; Update No. 24J.S. EPA 1987.
                                    123

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     If  known  or  suspected  industrial   sources  of  toxic  pollutants  or
pesticides  exist,  applicants  must submit  results  of wet- and  dry-weather
analyses of the treatment plant effluent.   If available,  Influent data would
also be  helpful.   If historic data  are available,  they  should  be presented
as well.  Results of the analyses  should be tabulated in  a summary form that
allows the  toxic quality of the discharge to  be evaluated.  The applicant
should  describe  the  sampling  effort  by describing  the  procedures  for
collecting,  compositing,  and  preserving  the  samples.   The number of grab
samples  taken for  volatile  organics  analysis  should  be  included  in  the
discussion.

     Rainfall data submitted for at least 5 days preceding the sampling will
confirm  wet or dry  conditions at the  time of sampling.   In past analyses
(Feiler  1980),  toxics concentrations  have  been substantially higher  during
Monday  through  Friday  than  on  Saturday  and  Sunday.     It  is  therefore
recommended  that composite  effluent  samples  not  be collected  on weekends
unless it can be shown that  this sampling period is more representative.

     Analytical  methods  should be discussed,  with appropriate  references to
published analytical  procedures.   The  identity of the analytical laboratory
should be  given.  Quality  assurance procedures for  the  analysis should be
summarized, and  results  presented  for review.   Differences between the wet-
and  dry-weather  analysis  should  be  explained,   if possible.    Also,  a
comparison with past results could be made.

     Sources  of  detected toxic  pollutants must  be  identified   and,  to the
extent  practicable,  categorized  according to  industrial  and  nonindustrial
origins.    The  purpose  of  this  identification  and  categorization   is  to
provide  a  useful reference  for  toxics monitoring and source controls.  If
the  applicant   recognizes   that  the  source  list  requires   improvement,
procedures  to accomplish this improvement should be described.  In-system
sampling and  analysis,  industrial  discharge analysis, permit  data, and site
inspections could yield quantitative  information as to sources of  identified
priority pollutants.
                                     124

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Special Considerations for Small Dischargers

     In the  original  Section  301(h)  application,  many small  applicants were
exempted  from  providing an analysis  of toxic substances and  pesticides  in
their effluent because  they were  able to certify  that there are no known or
suspected sources of those substances in their service area.  However, those
exemptions were not permanent  (U.S.  EPA 1982,  p.  53673).  Subpart 125.62(d)
requires  all Section  301(h)  permittees to analyze their effluent for toxic
substances  and pesticides,  to the  extent  practicable, as  part of their
monitoring programs.   Hence,  to the extent  practicable,  all  Section 301(h)
permittees  shall  have performed  at  least one  effluent analysis  for toxic
substances  at  a representative  time during the  5-yr term of  the original
Section 301(h) permit.   To the extent  practicable,  they shall  also perform
another  effluent  analysis  for toxic  substances  at  a  representative  time
during  the  5-yr term of the  reissued permit.   Results of  those analyses
should be used to demonstrate  compliance with federal water quality criteria.

          III.H.2.    a.   Are  there  any  known  or suspected  water quality,
          sediment  accumulation,  or  biological  problems  related  to toxic
          pollutants  or  pesticides  from  nonindustrial  sources  to  your
          modified discharge(s).

          b.  If no, provide the certification required by Subpart 125.66(d)-
          (2) together with available supporting data.

          c.  If yes, provide  a schedule for development and implementation
          of nonindustrial toxics control programs  to meet  the requirements
          of Subpart I26.66(d)(3).
***
    Only small dischargers must respond.
     The purpose of nonindustrial source control programs is to identify the
specific nonindustrial sources of priority  pollutants  and pesticides and then
to develop  specific  means  for  their  control.   To  properly  address  these
                                    125

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requirements,  the applicant should describe existing programs or  present  a
schedule  and  description of proposed programs to Identify  and control  non-
Industrial  sources  of toxic  pollutants  and pesticides.   At  a minimum,  all
applicants  must develop  a  public education program to  limit nonindustrial
sources (see Question  III.H.7 below).

     Nonindustrial source control programs must be developed and  Implemented
on  the  earliest  possible schedule.   Implementation  1s required  within  18
months  of  the Issuance  of  a  30l(h)-mod1f1ed permit.   The schedule  must
Include the following  two elements:

     •    A schedule of activities for identification of nonindustrial
          sources of toxic  pollutants and pesticides

     •    A   schedule  for   the   development   and   Implementation  of
          practicable  control  programs  for  nonindustrial   sources  of
          toxic pollutants  and  pesticides.

     Activities  to  Identify  nonindustrial  sources  could Include literature
searches,   in-system  sampling  and  analysis,  research  on  nonindustrial
products  commonly released  to the sewer,  and pooling  of  information  with
other POTW operators having a similar mix of users.

     There  are no clearly  defined rules  to determine  the  level  of effort
that an applicant should apply to Identify nonindustrial sources.   However,
this level  of effort  1s  expected to  be  directly related to the  size of the
discharger.    For example,   dischargers  with diverse  land  uses within the
service  area  may  find  1t  necessary  to  perform  in-system sampling  and
analysis  to explain  the  occurrence  of toxic pollutants and pesticides.

     Concentrations  of pollutants within the  system  that  are not accounted
for  by   industrial  sources  are  generally  attributable   to nonindustrial
sources.   Applicants  should  therefore  be careful  not  to  duplicate any in-
system sampling efforts performed for compliance with  industrial pretreatment
regulations.
                                    126

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     Extensive control measures may be necessary where nonIndustrial'sources
produce concentrations of  toxic  pollutants  and  pesticides  within  50 percent
or  more of  the  receiving water  criteria  after  Initial  dilution.   These
measures could  Include  control  of  the  sale,  use,  handling,  and  disposal
stages of substances that contain priority pollutants and pesticides.

     U.S. EPA recognizes the serious potential for adverse effects on marine
organisms  and humans  that  can  result  from bioaccumulation of  discharged
toxic  pollutants  and pesticides.   U.S. EPA also recognizes the potential
complexity of nonindustrial  source control  programs.   Therefore,  applicants
are encouraged to consult  with U.S.  EPA during  development of  nonindustrial
source control programs.  Proposed nonindustrial source control  programs are
subject to review and revision by U.S. EPA prior to issuing a Section 301(h)
modified permit, and during the term of any such permit.

          IIJ.H.3   Provide  the  results  of  wet-  and  dry-weather  effluent
          analyses  for  toxic  pollutants   and  pesticides   as  required  by
          Subpart 125.66(a)(l).

*** Large dischargers must  respond in full.   Small dischargers  must respond
to the extent practicable.

          III.H.4   Provide  an  analysis  of  known or  suspected  industrial
          sources of toxic pollutants and pesticides identified in 2. above.

*** Large dischargers must  respond in full.   Small dischargers  must respond
to the extent practicable.

          III.H.5.  Do you have an approved  industrial pretreatment program?

          a.   If yes, provide the date of U.S. EPA approval.

          b.   If no, and if required by 40  CFR Part 403  to have an industrial
          pretreatment program,  provide  a  proposed schedule for development
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          and Implementation of your  industrial pretreatment program to meet
          the requirements of 40 CFR  Part 403.

    Large and small dischargers must  respond.

     An  applicant  with  known  or  suspected  industrial   sources  of  toxic
pollutants  or  pesticides must  have  an  approved pretreatment program and
demonstrate  compliance with  Its  requirements.  Applicants that certify to
the Administrator that  they have no known or suspected Industrial  sources of
toxic  pollutants  or  pesticides  are  not  required  to have  an  Industrial
pretreatment program.

     In this section,  applicants required to have an industrial pretreatment
program should  clearly present the history of compliance  with the Part 403
industrial  pretreatment  program.    If such  a  program   has  already  been
approved by  U.S.  EPA it 1s only necessary  to  indicate the date of approval.
If the  program has  not been approved,  a  schedule  of activities,  including
the expected date  of submittal  to U.S.  EPA,  that will lead  to  compliance
with Part 403 must  be  provided.

          III.H.6.  Urban area pretreatment requirement [Subpart 125.65]

          a.    Provide data  on all  toxic pollutants  introduced  into the
          treatment  works  from  industrial sources  (categorical   and non-
          categorical).

          b.    Hote  whether  applicable pretreatment  requirements are  in
          effect  for every industrial  source  of  each  toxic pollutant.  Are
          the   industrial sources  introducing  such  toxic  pollutants  in
          compliance  with all of  their pretreatment requirements?  Are  these
          pretreatment requirements being enforced?  [Subpart 125.65(b)(2)]

          c.  If applicable pretreatment requirements do  not exist for each
          toxic pollutant  in the  P07H  effluent introduced  by   industrial
          sources,
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               Provide a description and a schedule for your development and
       -  :>  "implementation  of   applicable  p re treatment   requirements
               [Subpart 125.65(c)], or

               Describe  how you  propose  to  demonstrate secondary  removal
               equivalency  for  each of those  toxic pollutants,  including a
               schedule for compliance, by using a secondary treatment pilot
               plant.  [Subpart 12S.65(d)]

     Dischargers serving populations of 50,000 or more must  respond.

     At the  time of final  permit  approval,  applicants must have  In effect
applicable pretreatment requirements for each toxic pollutant from Industrial
users  that  1s  found 1n  the  proposed  discharge.   Applicable  pretreatment
requirements may take the  form  of  categorical  standards,  local  limits, or a
combination  of both.   When an Industrial discharger  is  subject to  both a
categorical standard and a local limit, the more stringent of the two limits
applies.

     Categorical  standards  (see  40  CFR 403.6)  are  nationally  uniform,
technology-based limits developed for specific industries.  They are applied
when categorical  Industrial  users  are the only  sources of  particular toxic
pollutants  in  the   POTW  waste stream.    Local  limits  for specific  toxic
pollutants  found in the discharge  are applied when  the  toxic  pollutants
cannot be entirely attributed to categorical  industrial users.

     Local  limits  (see  40 CFR  403.5)  are   determined  from  general  and
specific  prohibitions.    General   prohibitions  include  requirements  that
industrial users  may not  Introduce  pollutants into a POTW  that  will  cause
pass-through or  Interference with  the  treatment  works.   Pass-through is the
discharge of concentrations of  toxic pollutants  or  pesticides  that alone or
in combination with discharges from other sources will cause violation of the
applicant's  NPDES permit.    Interference is  the  disruption  of  treatment
processes or  operations that alone  or in combination with  discharges from
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other sources  causes a violation of the applicant's NPDES permit.   Specific
prohibitions   include  requirements  that  pollutants  with  the  following
characteristics shall  not  be  discharged to a POTW by industrial users:

     •    Pollutants that  create a  fire or explosion hazard

i    . •    Pollutants that  will cause corrosion to  a  POTW or have a pH
          below 5.0

     •    Pollutants that are solid or viscous and  are  discharged in
          amounts  that  will  obstruct flow  in the POTW,  resulting in
          interference

     •    Pollutants (Including  oxygen-demanding pollutants)  that are
          released at a rate  that will cause interference

     •    Heat in  amounts  that inhibit biological  activity in the POTW
          and  result  in interference, or  cause the temperature at the
          POTW to exceed 40°  C (104° F) without approval.

     For  every toxic  pollutant  in  the discharge  that is  not  from a cate-
gorical industrial user and for which there  1s  no local limit, the applicant
must develop  local  limits, or demonstrate secondary  removal equivalency to
the U.S.  EPA, or  use a combination of these  alternatives.  To demonstrate
secondary equivalency, an  applicant must demonstrate that the combination of
its  own  treatment  plus  pretreatment  by  industrial  dischargers achieves
"secondary  removal   equivalency."    A successful  demonstration of secondary
removal  equivalency will  show,  for each  toxic substance  in  the effluent,
that the  applicant's own  less-than-secondary treatment plus pretreatment by
industrial  dischargers removes that same  amount of each  toxic substance as
would  be removed  if  the  applicant  were  to apply secondary  treatment and
there were  no  pretreatment requirements for  those pollutants.    Applicants
must  make  this  demonstration  whenever  they  cannot show  that a  toxic
pollutant introduced by an industrial discharger 1s subject to  an "applicable
pretreatment requirement"  in  effect.
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     To  demonstrate  secondary removal equivalency, an  applicant  would need
to use a secondary treatment pilot plant.  By diverting part of its Influent
to the pilot plant, the applicant would empirically determine the incremental
amount of  each toxic  pollutant  that would be removed  from  the Influent if
secondary  treatment  were  applied.    Haying  determined  the  amount  of each
toxic  pollutant  removed,  the  applicant  would  then  demonstrate that  its
existing less-than-secondary  treatment  plus  industrial  pretreatment removes
the same amount of each toxic substance as did the secondary treatment pilot
plant without any industrial pretreatment.

     In cases where an applicant  already has an ongoing industrial pretreat-
ment  program,  it  may be  simpler to  perform  this empirical  demonstration
using influent that has  been  subject to that industrial pretreatment.  Such
a demonstration would  be conservative because  it  would  overstate the amount
of  toxic  pollutant  that   would  be  removed  by  applying  only  secondary
treatment.   Because it would  be  conservative,  applicants are permitted (but
not required) to make  the secondary equivalency demonstration using effluent
that has undergone industrial pretreatment.

          III.H.7.   Describe  the public  education program you  propose to
          minimize  the  entrance of  nonindustrial  toxic  pollutants  and
          pesticides into your treatment system [Subpart 125.66(d)(l)].

*** Large and small dischargers must respond.

     The applicant must propose   a public  education program  to minimize the
amounts  of  nonindustrial  toxic  pollutants  and  pesticides  that  enter  the
waste stream.  The plan must be implemented within 18 months of the issuance
of  a  301(h)  modified  permit.    The public education  program  may  include
preparation  of   newspaper   articles,   posters,   or  radio  and  television
announcements to  increase  public awareness of the need for  proper disposal
of waste  oils,  solvents, herbicides, pesticides,  and  other  substances that
contain toxic pollutants.
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      III.H.8  Provide  a  schedule  for development a/id implementation of
      a nonindustrial tvics control program to meet  the  requirements of
      Subpart 125.
Only large dischargers must respond.
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                   EVALUATIONS OF COMPLIANCE BY U.S. EPA
DETERMINATIONS OF COMPLIANCE WITH SECTION 301(h) MODIFIED PERMIT CONDITIONS
                            \
     POTVIs  that  hold  Section  301(h)  modified  permits  must  comply  with
Section  301(h)   criteria  and  regulations,  applicable  state water  quality
standards  and regulations,  and  federal  water  quality criteria  (U.S.  EPA
1986a).    General   guidance is  presented  below  for  assessing  whether  a
permittee's demonstration of compliance with the conditions specified in the
Section 301(h) modified permit  is  reasonable.   As discussed under Questions
II.D.1-II.D.4 of the Application Questionnaire  (above),  the newly mandated
federal  water  quality  criteria  [Subpart   125.63(c)(l)]  place  additional
requirements on  all Section 301(h) dischargers.  These federal water quality
criteria  have  the  potential  to  expand the  scope  of  the water  quality
demonstrations  that  must   be  made  by each  Section  301 (h)  discharger  to
include more variables, but do not create a fundamentally different, or new,
class of criteria  or  requirements  that must be met.  Therefore, the general
guidance provided  below  is also  relevant  to determinations of  compliance
with  the  newly  mandated  federal   water  quality  criteria  that  will  be
performed by the Regions.

     The first step  in evaluating a permittee's demonstration of compliance
with applicable  criteria  and regulations, or in determining compliance with
criteria and regulations when monitoring data are examined  by the Regions, is
to  compare  the  data that  were  submitted  by  the  permittee with  the  data
collection  requirements specified  in  the existing Section  301(h) modified
permit.  The following two  key questions should be addressed:

     •    Were   all   physical,  chemical,   and   biological   variables
          required by the Section 301(h) modified permit measured?
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     •    Was each required variable measured at the specified locations
          and at the  specified frequency?

If either question cannot be  answered affirmatively, the applicant should be
considered  not to  have  complied with  the terms  of  the existing  Section
301(h) modified permit.

     In  cases of  apparent noncompllance,  the  Regions  have  the option  of
denying  the  application  for reissuance  of  the  modified  permit  without
further  examination  of the  monitoring  data.   However, the Regions  are
strongly  advised  to  ask the applicant  (if no  explanation of the  apparent
deficiencies  was previously  made  by the  applicant)  the  reasons   for  the
apparent  noncompliance.   Unforeseen events or conditions beyond the control
of  the  applicant  may  have  been  responsible  for  failures  to execute  the
conditions of the modified  permit.

     Having  received  all  the  appropriate  data  from  the  applicant,  the
Region's  second  step is to evaluate the technical  merit and (as warranted)
the applicant's  interpretation of those  data.   Three major issues should be
addressed during that evaluation:

     •    Data quality

     •    Execution of the  analyses
       «
     •    Interpretation of the  analytical results.

Successful demonstrations of  compliance should provide  sufficient information
for the Region to document  that  data quality  is high,  analyses were properly
executed, and data interpretation  is reasonable.

     To  determine whether the applicant's data were collected properly, the
Regions are referred  to  guidance given by  Tetra Tech (1982a,b, 1987c)  and to
guidance  given  under the appropriate questions  in the Application Question-
naire  (especially Questions III.F.1-III.F.2).   Of critical importance  to the
                                     134

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collection  of  data  for any  variable  is  whether appropriate  field  and
                                                                     »
laboratory  methods  were used to  collect the data, and  whether  appropriate
quality  assurance/quality control  procedures  were followed.   Data are  of
little value  if they were collected using  inappropriate methods,  or if the
collection process was so poorly executed that their accuracy is in doubt.

     As  is  true  for data  collection  methods,  data  analysis methods  vary
greatly  among  the  various types  of  physical,  chemical,  and  biological
variables.  Again, the Regions are referred to the aforementioned documents.
The following general questions should be addressed during the evaluation of
the data analyses:

     •    Are values for each variable reported 1n appropriate units?

     •    Are the  analytical  methods appropriate  for  the  type  of data
          being analyzed?

     •    Do  the mathematical or  graphical  analyses illustrate what is
          being discussed in the text of the application?

     •    Are calculations  correct,  and have  data points  been plotted
          correctly?

Provided that the  foregoing questions (and  other  questions  related to data
analysis that may be  relevant  in  specific instances)  are  answered in the
affirmative, the Region should determine whether the applicant's data and the
results of  analyses  of those data  support  the applicant's conclusions.  If
the Region  determines otherwise,  alternative  conclusions  must be developed
by the  Region  for  use in  determining  whether the applicant's  existing or
proposed discharge contributes  to adverse  impacts  on  the receiving  environ-
ment or biota.
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DETERMINATIONS OF COMPLIANCE  WITH 301(h) CRITERIA
                                                                     •

     When  the permittee's  monitoring data  Indicate  that Impacts to  water
quality, sediment quality,  or biota are occurring,  1t will  be necessary for
the Regions  to determine whether such  Impacts  are  adverse.   Determinations
of  adverse  Impacts are  reasonably  straightforward  for many physical  and
chemical criteria  (e.g.,  dissolved oxygen concentrations, concentrations of
toxic  substances in the  water column after  Initial  dilution) because such
criteria  are quantitative,  and because  determinations  of  compliance rely
primarily  on  the  results  of  wel1-documented mathematical  calculations.
Providing  that  the physical  and chemical  data were  properly  collected and
analyzed,  the resultant values for each physical  and chemical  variable need
only be  compared with  applicable  Section  301(h)  criteria,  state standards,
and federal  water  quality  criteria.    Results  of those  comparisons  can be
used to determine the presence of an adverse impact that causes noncompllance
with Section 301(h) criteria.

     When  the values  of one or more  physical or chemical  variables con-
sistently  fall  outside the ranges  specified  by the  foregoing  criteria, the
discharge  can  be inferred  (by  definition)  to be  causing adverse Impacts to
the  physical  or  chemical   characteristics  of  the  receiving  environment,
thereby resulting  in noncompliance with Section 301(h)  criteria.   In those
cases, the Regions  have the option of denying the request for reissuance of
the Section  301(h)  modified  permit,  or requesting that  the applicant make
improvements  to  the outfall  or treatment  system such  that  compliance with
applicable criteria  Is  assured.    In  most  cases,  applicants  proposing
improvements  will  be required  to  predict  the  values  of previously  noncom-
pl iant variables following  implementation  of  the proposed improvements.

      Determinations  of  the  presence or  absence of  adverse  environmental
impacts that  result in noncompliance with Section  301(h) criteria are more
difficult  for biological  criteria because adverse  impacts  are  not  defined
quantitatively.   Some  extreme  adverse  impacts may be  assessed  more  easily
because they are defined  specifically in the  301(h) regulations, and because
they are endpoints  in  a spectrum of possible biological  conditions that may
                                    136

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result  from  the  discharge  of  sewage  effluent.   For  example,  the  301(h)
regulations  state that  conditions  within the  ZID must  not contribute  to
extremely adverse biological Impacts, Including the following conditions:

     •    Destruction of distinctive habitats of limited distribution

     •    Presence of disease epicenters

     •    Stimulation of phytoplankton blooms that have adverse Impacts
          beyond the ZIO

     •    Conditions  that  result  in  mass   mortalities  of  fish  and
          Invertebrates.

The  regions  should deny  applications  for  reissuance  of  Section  301(h)
modified permits where such  impacts have been demonstrated to occur over the
life of  the  existing permit, or are  expected to  occur  over  the  life of the
reissued  permit.    The  Regions  may  consider   applications  that  propose
improvements to eliminate any of the foregoing adverse impacts.  But because
all of these impacts are considered extremely adverse, it would be difficult
to  demonstrate  that a  balanced Indigenous  population  will  become  rees-
tablished following  Improvements to the treatment plant or outfall.

     Many  biological  Impact assessments  that  are  required  under  301(h)
regulations  necessitate determinations of degrees  of  impact relative to
unstressed conditions,  and  subsequent  judgments  as  to  whether  documented
changes  are  in  compliance  with  301(h) criteria.   These assessments  rely
largely  on comparisons  of biological  conditions  between reference areas and
potentially  impacted  areas  to  determine the  locations  of changes  along
theoretically  or empirically derived gradients  of  impacts.   Quantitative
comparisons  between reference  and  potentially  impacted  areas may  be made
using various  types of  biological  date  [e.g.,  numbers of  individuals per
unit  area,  values  of  the   Infaunal  Trophic  Index  (Word 1978,   1980)]  and
various analytical tools (e.g.,  normal classification analysis) as discussed
under Question III.0.1  (above).  However,  no quantitative  biological criteria
                                    137

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have been  established by which the results of these analyses may be judged.
Therefore,  determinations  of  whether  changes  In,  or differences  among,
biological communities  constitute  noncompl1ance with Section 301(h) criteria
require careful  consideration of the types of responses that are manifested
by the pollutant  stress,  as well as  their  spatial extents and magnitudes.

     Three  approaches  have  been  used  1n the  301(h)  program  to  determine
whether a  specified degree of change 1n the biota (and associated receiving
environment)  should be  considered  to be 1n compliance with 301(h)  criteria.
The first  1s  to determine whether  the observed change represents a reduction
1n the areal  extent or  health of a community or ecosystem.  This approach has
most often been  used  1n cases  where  the major taxa  that characterize the
community greatly modify  the  environment,  thereby creating habitat for other
species.   Primary examples Include distinctive habitats of limited distribu-
tion such  as  kelp communities,  coral reefs, and seagrass beds.  Because most
of the taxa 1n these communities are highly dependent on the major taxa that
characterize  the community (and create habitat niches), the  loss  of those
major taxa due to pollutant Impacts  results 1n destruction of the community.
Unlike some  other communities  (such as benthic  Infauna),  one assemblage of
organisms  1s not replaced by  another 1n which  the  species  belong  to the
same, or similar, major taxonomlc  groups,  and  In which the new taxa are able
to  tolerate,  and   In  many  cases  thrive,   in   the  modified  environment.
Clearly,  1n  cases  where  a community or ecosystem  1s  highly dependent on a
limited  number  of   major taxa  to provide habitat  for  a wide variety of
dependent  species,  any  loss  or decline  in the health of those major taxa 1s
an adverse Impact,  and  1s therefore  not in compliance with 301(h) criteria.

     In  communities  where  pollutant  Impacts  result  in  changes  1n species
composition and  abundance,  but not 1n  the destruction of the  habitat,  It Is
more difficult  to  determine  whether  such changes  constitute noncompllance
with Section  301(h) criteria.   However,  two  approaches to the problem have
been used  In  the 301 (h) program.  The  first Is based on the assumption that
a major change  In the  function (I.e.,  trophic relationships)  of a community
(e.g.,  benthic  infauna,  demersal  fishes)  constitutes  noncompl1ance with
                                     138

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Section 301(h) criteria  because  1t  affects,  or  has  the potential  to affect,
all  of the  major  elements  of  the ecosystem.    The  second  approach 1s  a
corollary  of the first.   It assumes that a major  change in the  structure
(I.e.,  species  composition  and  abundance)  of  a  community  constitutes
noncompl1ance with  Section 301(h) criteria because  a change  In  the function
of that community  has occurred,  regardless  of whether a  change 1n function
can  be  demonstrated.   Because a change in the structure of  a  community is
usually much easier  to  document  than  1s  a change in the  function of  a
community, the  second approach  has been used  most commonly in the 301 (h)
program.

     Benthic  infauna  are used in the  following example to  demonstrate  how
the functional and structural approaches may  be implemented.  The generalized
model  developed  by Pearson  and Rosenberg  (1978)   for  changes in  benthic
communities along a gradient of  organic enrichment  (Figure 3) has  been used
extensively  in the 301(h) program,  and has  been successfully  applied to a
variety  of  soft-bottom  benthic  communities  in  temperate  and  tropical
latitudes.   At  low  to  moderate levels of  organic enrichment (I.e.,  the
"transition zone" in  Figure  3),  biomass increases moderately and numbers of
species Increase slightly.   Abundances do  not  increase greatly  until  the
"ecotone point"  is  approached.   In the "transition zone," there Is simply an
enhancement  of the community that  1s  typical of the biogeographic region,
with the  addition  of a  few  new  species.  There are  no  major functional or
structural changes.   Providing  that there are no major problems with other
aspects of the benthic  Infauna  (e.g.,  bi ©accumulation of toxic substances),
the  impact to benthic Infauna may not  be considered to be out of compliance
with Section 301(h) criteria.

     At and beyond  the  "peak of  opportunists" as shown in Figure 3, Pearson
and Rosenberg (1978)  document that  species composition and  abundance of the
benthic Infauna  change substantially.   The-fauna becomes dominated by a few
opportunistic  or   pollution-tolerant   species   whose  abundances  increase
dramatically  in  response to  Increased  organic loading.    Most   of  these
species are  surface or subsurface deposit feeders.   Suspension feeders and
surface detrital  feeders typically decrease  in abundance, or are eliminated.
                                    139

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                    Increasing Organic Input
                    S » Species numbers
                    A » Total abundance
                    B • Total biomass
                    PO « Peak of opportunists
                    E • Ecotone point
                    TR » Transition zone
                                    Reference: Figure 2 of Peaison and Rosenberg (1978).
Figure 3.  Generalized depiction of changes in species numbers, total
          abundances, and total biomass along a gradient of organic
          enrichment.

                            140

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Hence,  the  structure (I.e.,  species composition and abundance)  and function
(I.e.,  trophic  relationships)  of  the  benthic  infauna  are  altered  sub-
stantially.

     In most  cases,  Information 1s not available to  demonstrate that major
changes  in  the  structure and  function  of  a particular  benthic  community
affect  other  biological  communities (e.g.,  demersal fishes).   However, many
cases of  prey specificity by  demersal  fishes and  large  epibenthic invert-
ebrates that  prey on  benthic  Infauna have been recorded  in  the scientific
literature.   Hence,  there 1s  a  sound scientific  basis  for  assuming that
major changes In  the structure  and function  of  benthic communities  as a
result  of organic enrichment can  induce changes in the  species composition
and abundance of predators on  Infauna, most of which are demersal fishes and
large epibenthic  Invertebrates.   Therefore,  major  changes in  the structure
and function  of the  benthic  infaunal  community have  often been considered
to constitute noncompl1ance with Section 301(h) criteria.

     Decisions regarding  adverse Impacts  should be based  on the results of
the biological demonstrations  required of the applicant in the various parts
of the  Application  Questionnaire.   Those  biological  demonstrations should
Include monitoring data  collected over  the  term  of  the  existing modified
permit.   The Regions  are  referred  to discussions under relevant questions in
the questionnaire  (above) for  guidance on data analysis and interpretation.

     If  a  Region decides  that  an existing  discharge  may  be causing  an
adverse  impact  to  the biota,  or  that the proposed  discharge  will likely
cause  an  adverse  Impact to  the  biota,   the  Region  should  require  that
applicant  to  perform detailed  biological  demonstrations to  support  the
application.   Such  demonstrations would  most  likely be  required  in cases
where possible  adverse  Impacts  would result in noncompl1ance  with Section
301(h) criteria,  such as  adverse Impacts  to distinctive  habitats of limited
distribution, discharges  Into  estuarine waters, and discharges into  stressed
waters.    It  Is  Important that  the Region  work closely with  the applicant
over the  term of  the existing permit,  so  that  possible  adverse impacts or
conditions  that  would result  in  noncompllance  with Section 301(h)  criteria
                                    141

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are Identified well  1n advance of the application deadline.   Early notlflca-
                                                                     *
tion  of  potential  adverse  Impacts  will  ensure  that  the  applicant  has
sufficient  time  to  design  and  execute  appropriate  studies.   The  Region
should  also work closely with  the applicant  during  all  phases of  survey
design and execution to ensure the collection of adequate, high quality data.

EVALUATIONS OF PREDICTED  CONDITIONS AND PREDICTED CONTINUED COMPLIANCE

     POTWs  were  allowed  to  apply for  first-time  Section  301(h)  modified
permits  based  on current,   Improved,  or  altered  discharges.   A  current
discharge  1s  defined 1n  Part 125  Subpart G as the  volume,  composition,  and
location of an  applicant's  discharge  at the time of permit application.   An
Improved  discharge  may   Include  planned   Improvements in  the  outfall,  the
level of treatment,  discharge characteristics,  operation and maintenance, or
controls on  the  Introduction of pollutants Into the treatment  system.   An
altered discharge 1s defined  as  any discharge other than a current discharge
or an Improved discharge  as defined 1n  Part  125.58.

     For  Improved   and   altered  discharges,  applicants  were  required  to
predict conditions that  would occur  In the receiving  environment following
implementation  of the  proposed  Improvements or alterations.   Section 301(h)
modified  permits  were Issued  upon a  satisfactory demonstration  that  the
predicted  conditions  were  reasonable  and  would  satisfy  Section  301(h)
criteria  and  regulations.    For dischargers whose original  Section 301(h)
modified permit  was  issued based  1n  part on predictions  of conditions that
would occur after proposed Improvements or  alterations were implemented, it
1s  necessary  to evaluate   whether  the  predicted  conditions  have  been
realized.   Because  the  Regions  should  receive monitoring  data collected
during  the term  of  the  existing  permit  in support of the  application  for
permit  reissuance,  evaluations  of the applicant's original  predictions of
compliance are not unlike other determinations of compliance.  Therefore, the
Regions  should  conduct   those  evaluations  as  discussed  above  in  the  two
previous  sections of  this  chapter, entitled  "Determinations  of Compliance
with  Section  301(h)  Modified  Permit  Conditions"  and   "Determinations  of
Compliance with  301(h) Criteria."
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     As was permitted for original Section 301(h) applications, applications
for  reissuance  of  Section 301(h)  modified  permits  may propose  Improved
levels of  sewage  treatment,  either  1n response to comments by the U.S. EPA,
or at  the  permittee's Initiative.  Applications  for permit  reissuance that
are  based  -on  altered  discharges are  also permitted  when  downgrading  of
effluent  quality  1s  attributable  entirely  to  population  growth  and/or
Industrial  growth within  the  service area.    Proposals  for  Improved  and
altered  discharges   mandate  that   the  permittee  predict   the  physical,
chemical,  and  biological conditions  that will  occur In the  receiving  en-
vironment.  In  such  cases  [as 1n the original  Section 301(h) applications],
1t will  be necessary  for the  Regions to evaluate  whether  the permittee's
predictions  are  reasonable,  and whether  the  predicted conditions  would
satisfy Section 301(h) criteria and regulations.

     Evaluations  of  applicant's  predictions  should Include  the  following
assessments:

     •    Appropriateness of the models used to generate the predictions

     •  .  Data quality

     •    Execution of the analyses

     •    Interpretation of the analytical results.

It  1s  essential  that  the  applicant  conduct   each  of these  steps  In  the
predictive  process  properly.   Otherwise, the  validity  of the  results  and
compliance with applicable regulations and criteria will be suspect.

     To  predict  conditions  that will  occur  as a  result  of a  proposed
discharge,  applicants may compare attributes of the proposed discharge (e.g.,
volume and composition) and receiving environment with conditions near other
outfalls that  discharge effluent of  similar volume  and  composition  and in
similar receiving environments.   The validity  of such  comparisons  rests on
                                    143

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the  similarity  of  the  discharges  and  the  similarity  of  the  receiving
environments.  Substantial  differences  1n the volumes  of  the  two discharges
or  the mass  emission  rates of  pollutants from  the  two discharges  would
render  such  comparisons  questionable,  especially  for  biological  variables.
For  physical  and  chemical   variables,  it might be  possible to  compensate
mathematically  for  such  differences.    However,  biological  responses  to
pollutants  cannot  be  assumed  to be  linear.    Therefore,  the validity  of
predictions Involving comparisons between substantially different discharges
1s  very  tenuous  unless the  response  patterns  of  the biota  within  the
biogeographlc region are well known.

     Similarity  of  the  receiving  environments 1s  also  critical  to  such
comparisons.  It is important that both discharges  be located within the same
biogeographlc  zone  because  responses   to  pollutants  vary  among  species.
Species  in one  biogeographlc zone  may  respond somewhat  differently to  a
given  pollutant  than do species in  another biogeographlc  zone.   For that
reason, it may be  possible to predict the general  types of changes that may
occur  as  a result  of  the proposed discharge, but it  will not  generally be
possible  to  predict the areal  extent or magnitude of  such changes.   It is
also  important  that  the  physical  and  chemical  characteristics  of  both
receiving  environments   be  similar.     For  example,   discharges  into  open
coastal  areas should not be compared  with discharges in embayments.   The
more  similar the  two  receiving  environments are to  each  other,  the more
reliable the applicant's predictions may  be  assumed to be.

     Applicants  may also use models  that  describe  cause-and-effect  rela-
tionships to predict Impacts of the proposed discharge. Such models would be
especially helpful  for  physical  and chemical variables (e.g.,  deposition of
suspended  solids  in  the  receiving  environment,  concentrations  of  toxic
substances at the  ZID  boundary).   The appropriateness of such models should
be  judged on  their prior  use  in the  301(h) program, their  acceptance or
recommendation  by  the   U.S.  EPA, and  their  acceptance  by the  scientific
community.  Models  that have not been evaluated previously or that have not
been received favorably should be avoided.
                                     144

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     Having determined that the applicant used appropriate models to predict
conditions 1n the receiving environment and biota,  the Region  should address
the  Issues  of data  quality,  execution of  analyses,  and  interpretation  of
analytical results.  These Issues should be addressed in a manner similar to
that described above for determining compliance with Section 301(h) modified
permit conditions.
                                    145

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        REISSUANCE OR TERMINATION OF SECTION 301(h) MODIFIED  PERMITS
     As stated in Subpart  125.59(c)(4), Section 301(h) modified permits "may
be renewed  under the  applicable procedures of 40 CFR  Part  124."   Relevant
subparts  are Parts 124  Subparts A  (General  Program  Requirements)   and  D
(Specific Procedures Applicable to NPDES  Permits).   These subparts provide
an outline of the mechanics  of the permit  decision-making process,  including
review  of applications  for  completeness,   conditions for  permit reissuance
and  termination,   and   special  procedures   applicable  to  Section  301(h)
modified  permits.    Important  sections   of  these  subparts  are  discussed
briefly below.

      In  addition,   Part 124  provides  procedures for  public  notification,
public hearings, issuance of draft permits, and keeping  of the administrative
record  (Subparts A and D);  procedures governing evidentiary  hearings  for
U.S.  EPA-issued NPDES  permits  (Subpart  E);  and  procedures  governing non-
adversary panel  hearings  (Subpart  F).   These  procedures  are  not  discussed
below as they are beyond the scope of this document.

PROCEDURES FOR REGULATORY  ACTION

     Part 124 contains U.S.  EPA procedures for issuing, modifying, revoking
and reissuing,  and  terminating all  NPDES permits.   Other types of permits
are also  included.    Regulatory terms used in  Part  124 are  defined in Part
124.2.  All  definitions in  this subsection remain applicable to applicants
for reissuance of Section  301(h) modified  permits.

     Subpart D  of  Part  124  establishes decision-making procedures that are
specific  to NPDES  permits.    All tentative  decision  documents for  301(h)
permit  renewals  must be signed by  the  appropriate Administrator.   A tenta-
tive  decision  document  may  go  to  the checklist  procedure  recommended  for
                                     146

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original  301(h)  decisions, or  may simply  be  represented by a  cover sheet
referencing the fact sheet and draft permit.

     Special procedures relevant to applications for Section 301(h) modified
permits are set forth In Part 124.68.  These procedures were also applicable
to original  Section 301(h) applications, and  remain  applicable  to applica-
tions for relssuance of Section  301(h)  modified permits.   When an applicant
falls to meet Section 301(h) requirements, the Region must deny the request.
Information collected during monitoring studies and other studies conducted
during  the  term  of the  existing  Section  301(h)  modified  permit will  be
critical  to this  determination.    According  to  Subpart  125.59(e)(H1)(B),
125.61(b)(2),  and  125.64(b),  the  U.S.  EPA may not Issue a  Section  301(h)
modified  permit  unless  the state  has  concurred or waived concurrence.   It
also specifies  actions that may be taken  by  the State  Director in  states
with approved NPOES permit programs (discussed earlier).

REGULATORY OPTIONS

     Depending on  the  Region's  decision  regarding relssuance of a Section
301(h) modified permit, the applicant's permit may be reissued with changes,
reissued  without  changes,  or  terminated.   Administrative procedures  that
should  be followed by  the  Regions when permits  are  reissued or terminated
are  set forth 1n  Part  124.5,  and are  not  discussed herein.   However,  the
conditions  under  which each  of  these two  regulatory  options  apply  are
relevant  to the decision-making  process.   These  conditions, set  forth In
Part 122.62-122.64, are discussed below.

     Section 301(h)  modified  permits may be  terminated during  the term of
the  permit,  or may be  denied  during the permit  relssuance process for the
following reasons, which are set forth 1n Part 122.64:

     •    Noncompl1ance with the conditions of the modified permit

     •    Failure  to provide  all relevant  information  or misrepresen-
          tation of relevant information
                                    147

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                                                                     •
     •    A  determination that the  modified  discharge  endangers human
          health  or the environment, and that such adverse Impacts can
          be  reduced to  acceptable  levels  through permit modification
          or  termination

     •    Any condition  that  results  1n  a  temporary   or  permanent
          cessation of the discharge, such as the consolidation of two
          POTWs   that  results  1n   elimination   of  the  permittee's
          discharge.

All  terminations  of permits  must  be  made  in  accordance with procedures
specified in  Part  124.

     When it  1s evident for reasons specified in Part 122.64 that termination
of a Section  301(h) modified permit 1s warranted, the Regions may terminate
the permit under  applicable  procedures  of Part  124.  Section 301(h) modified
permits may  be  reissued under the provisions of Subpart 122.62(b).  Because
no specific guidance  is given  as to  which of  these two regulatory options is
appropriate  under different conditions,  the  Regions  have considerable dis-
cretionary authority over the reissuance or termination of a Section 301(h)
modified  permit  that has not been  in compliance with  all  of  the 301(h)
regulations.   In cases where  1t does not appear  that  the applicant will be
able to satisfy  the conditions of  the 301(h) regulations while holding a
Section 301(h)  modified permit,  the modified permit should be terminated or
allowed to expire  without reissuance.   However, 1n cases where conditions of
the permit may be adjusted to achieve compliance with the 301 (h)  regulations,
the  Region  may modify  the permit with different  permit  specifications, as
necessary.    Effective adjustments  of  the  permit conditions  will  require
careful examination of all  available data and accurate  predictions of the
conditions that will  result  as a consequence  of those adjustments.
                                     148

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Christodoulou, G.C., J.J.  Connor,  and B.R.  Pearce.   1976a.   Mathematical
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Christodoulou, G.C., J.J. Pagenkopf, B.R.  Pearce, and J.J. Connor.  1976.  A
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Elliot, E.L.,  and  R.R.  Colwell.   1985.  Indicator  organisms  for estuarine
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Fischer, H.B., E.J.  List, R.C.Y. Koh, J. Imberger,  and  N.H. Brooks.   1979.
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Grace, R.  1978.  Marine outfall systems planning, design, and construction.
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Koh, R.C.Y.   1973.   Hydraulic  test of discharge ports.  Technical Memorandum
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McDermott, D.J., G.V.  Alexander,  D.R.  Young,  and A.J.  Mearns.   1976.  Metal
contamination of flatfish around a large submarine outfall.   J. Water Pollut.
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McDermott-Ehrlich,  D.J.,  M.J. Sherwood,  T.C.  Heesen,  O.R.  Young,  and A.J.
Mearns.    1977.     Chlorinated  hydrocarbons  in  Dover  sole,  Microstomus
pacificus:  local migrations and fin erosion.  Fish.  Bull. 75:513-517.
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McDermott-Ehrlich, O.J., D.R. Young, and T.C. Heesen.  1978.  DDT and PCB In
flatfish  around   southern  California  municipal   outfalls.     Chemdsphere
6:453-461.

Mearns, A.J., and  M.  Sherwood.   1974.   Environmental aspects of fin erosion
and  tumors   in  southern  California Dover  sole.    Trans.  Amer.  Fish.  Soc.
103:799-810.

Metcalf and  Eddy.  1979.   Wastewater engineering:  treatment/disposal/reuse.
McGraw-Hill  Book Company,  New York, NY.  920 pp.

Muellenhoff,  W.P.,  A.M. Sol date, Jr.,  D.J.  Baumgartner,  M.D.  Schuldt,  L.R.
Davis, and W.E.  Prick.   1985a.   Initial mixing characteristics of municipal
ocean  discharges.   Volume I  -  procedures and  applications.   EPA-600/3-85-
073a.  U.S.  Environmental  Protection Agency, Narragansett, RI.  90 pp.

Muellenhoff,  W.P.,  A.M. Soldate, Jr.,  D.J.  Baumgartner,  M.D.  Schuldt,  L.R.
Davis, and W.E.  Frick.   1985b.   Initial mixing characteristics of municipal
ocean  discharges.  Volume  II  -  computer programs.   EPA-600/3-85-073b.  U.S.
Environmental Protection Agency, Narragansett, RI.  100 pp.

National Ocean Survey.  1988a.  Tidal current tables 1988, Atlantic Coast of
North America.  U.S.  Department of Commerce,  National Oceanic and Atmospheric
Administration, National Ocean Survey,  Washington, DC.

National Ocean Survey.   1988b.   Tidal  current tables 1988, Pacific Coast of
North  America and Asia.   U.S.  Department  of Commerce,  National Oceanic and
Atmospheric  Administration, National Ocean Survey, Washington, DC.

Pagenkopf, J.R., G.C. Christodoulou, B.R. Pearce, and J.J. Connor.  1976.  A
user's manual  for "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 of Civil Engineering.

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.

Sheng, Y.P.,  and H.L. Butler.   1982.  A three-dimensional numerical model of
coastal, estuarine, and lake  currents.   ARO Report 82-3.  Proc.  of the 1982
Army Numerical Analysis and Computer Conference.

Spaulding, M.L.,  and  D. Pavish.  1984.  A three-dimensional numerical model
of particulate  transport  for coastal waters.   Continental  Shelf Res. 3:55-
67.

Stumm, W., and J.J. Morgan.   1981.  Aquatic  chemistry.  John Wiley and Sons,
Inc.,  New York.  780  pp.

Tetra  Tech.    1982a.    Design  of  301(h) monitoring  programs  for municipal
wastewater  discharges  to  marine waters.   EPA-430/9-82-010.   U.S. Environ-
mental Protection  Agency,  Washington, DC.   135  pp.

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Tetra  Tech.    1982b.    Revised Section  301(h)  technical support  document.
EPA-430/9-82-011.  U.S. Environmental Protection Agency, Washington, DC.

Tetra Tech.  1985a.  Bioaccumulation monitoring  guidance:  1.  estimating the
potential  for  bioaccumulation of priority pollutants  and 301(h) pesticides
discharged  into marine and  estuarine  waters.    EPA-430/9-86-005.   Final
report  prepared  for  Marine  Operations Division,  Office  of  Marine  and
Estuarine  Protection,  U.S.  Environmental  Protection  Agency.   EPA Contract
No. 68-01-6938.  Tetra Tech,  Inc., Bellevue,  WA.  69 pp.

Tetra Tech.  1985b.   Bioaccumulation monitoring guidance:  2.   selection of
target species  and review of available  bioaccumulation  data.   Final  report
prepared  for Marine  Operations  Division,  Office of  Marine and  Estuarine
Protection,  U.S.  Environmental Protection Agency.  EPA Contract No.  68-01-
6938.  Tetra Tech, Inc., Bellevue, WA.   52 pp.

Tetra Tech.   1985c.   Bioaccumulation monitoring  guidance:   3.   recommended
analytical detection  limits.    Final report  prepared  for Marine Operations
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Protection Agency.  EPA Contract No.  68-01-6938.   Tetra Tech, Inc., Bellevue,
WA.  23 pp.

Tetra Tech.   1985d.   Bioaccumulation monitoring guidance:  4.   analytical
methods for  U.S.  EPA priority  pollutants and 301(h)  pesticides  in tissues
from  estuarine and  marine  organisms.    Final  report  prepared for  Marine
Operations Division, Office of Marine and Estuarine Protection, U.S. Environ-
mental Protection  Agency.   EPA Contract  Mo.  68-01-6938.   Tetra Tech, Inc.,
Bellevue, WA.

Tetra Tech.  1985e.  Summary  of U.S.  EPA-approved methods, standard methods,
and other  guidance for 301(h) monitoring variables.   Final  report prepared
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U.S. Environmental  Protection Agency.   EPA Contract No.  68-01-6938.   Tetra
Tech, Inc., Bellevue, WA.  16pp.

Tetra Tech.  1986.  Analytical  methods for U.S. EPA priority pollutants and
301(h) pesticides  in  estuarine and  marine sediments.   Final  report prepared
for Marine Operations Division, Office  of Marine and  Estuarine Protection,
U.S. Environmental  Protection Agency.   EPA Contract No.  68-01-6938.   Tetra
Tech, Inc., Bellevue, WA.

Tetra Tech.  1987a.   Evaluation of survey positioning methods  for nearshore
and estuarine waters.   EPA-430/9-86-003.  Final  report prepared for Marine
Operations  Division,  Office  of  Marine  and  Estuarine  Protection,  U.S.
Environmental Protection Agency.  Tetra  Tech, Inc.,  Bellevue,  WA.   54 pp.  +
appendices.
                                    151

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Tetra  Tech.  1987b.   Guidance for  conducting fish liver pathology  studies
during  301(h)  monitoring.    EPA-430/9-87-004.    Final  report prepared  for
Marine  Operations  Division,  Office  of  Marine  and  Estuarine  Protection,
U.S. Environmental  Protection  Agency.   Tetra  Tech,  Inc.,  Bellevue,  WA.
130 pp. +  appendix.         -

Tetra Tech.  1987c.  Quality assurance and quality control (QA/QC) procedures
for 301(h) monitoring programs:   pidance  on field  and laboratory methods.
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Tetra  Tech.   1987d.   Bioaccumulation monitoring  guidance:   5.   strategies
for  sample replication and  compositing.    EPA-430/9-87-003.    Final  report
prepared  for Marine  Operations  Division,   Office of Marine  and  Estuarine
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Bellevue,  WA.

Tetra Tech.  1987e.   Framework for 301(h) monitoring programs.  EPA-430/09-
88-002.   Final  report  prepared  for  Marine Operations Division,  Office of
Marine  and  Estuarine  Protection,  U.S.   Environmental  Protection  Agency.
Tetra Tech, Inc.,  Bellevue,  WA.   44  pp.

Tetra  Tech.   1987f.   Recommended biological  indices  for  301(h) monitoring
programs.   EPA-430/9-86-004.   Final  report prepared  for  Marine Operations
Division,  Office  of Marine and  Estuarine  Protection, U.S.  Environmental
Protection Agency.  Tetra Tech,  Inc.,  Bellevue, WA.   17 pp.

Tetra  Tech.   1988.   Evaluation  of  differential  Loran-C  for  positioning in
nearshore  marine  and  estuarine  waters.   Draft  report prepared  for Marine
operations  Division,   Office of Marine  and  Estuarine  Protection,  U.S.
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Inc.,  Bellevue,  WA.

U.S.  Environmental   Protection   Agency.     1980.     Water   quality  criteria
documents;  availability.    U.S.  EPA, Washington,  DC.    Federal  Register
Vol. 45, No. 231.  pp. 79318-79379.

U.S.  Environmental Protection Agency.   1982.   Modifications  of secondary
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EPA, Washington, DC.  Federal Register Vol.  47, No. 228.  pp. 53666-53684.

U.S.  Environmental Protection  Agency.   1985a.    Methods for measuring the
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Laboratory, Cincinnati, OH.   216 pp.

U.S.   Environmental   Protection   Agency.     1985b.  Water quality  criteria;
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U.S. Environmental  Protection  Agency.   1986a.  Quality  criteria  for water-
1986.   EPA-440/5-86-001.   U.S.  EPA,  Office of Water  Regulations  and Stan-
dards, Washington, DC.

U.S. Environmental  Protection Agency.   1986b.   Training manual  for NPDES
permit writers.  U.S. EPA, Office of Water Enforcement and Permits, Washing-
ton, DC.  98 pp. -i- appendices.

U.S.  Environmental   Protection Agency.    1987.    Update No.  2 to  quality
criteria  for water  -  1986.    U.S.  EPA,  Office  of  Water  Regulations  and
Standards, Washington, DC.  (1 May 1987).

Wang, J.D.,  and J.J. Connor.   1975.   Mathematical modeling  of near coastal
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Westerink,  J.J., K.D.  Stolzenbach and  J.J.  Connor.    1985.   A  frequency
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Word, J.Q.   1978.   The infaunal trophic  index,   pp. 19-39.   In:   Coastal
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Coastal Water Research Project, El  Segundo, CA.

Word, J.Q.    1980.   Classification of benthie invertebrates  into infaunal
trophic  index feeding  groups,   pp.  103-121.   In:   Coastal  Water Research
Project, Biennial Report for the years 1979-1980.  W. Bascom (ed).  Southern
California Coastal Water Research Project, Long Beach, CA.

Young,  D.R.,  D.J. McDermott,  and T.C.  Heesen.  1976a.  DDT in sediments and
organisms around southern California outfalls. J.  Water  Pollut. Control Fed.
48:1919-1928.

Young,  D.R.,  T.C. Heesen,  and  D.J. McDermott.  1976b.  An offshore biomoni-
toring system for chlorinated hydrocarbons.  Mar.  Pollut. Bull. 7:156-159.

Young,  D.R.,  M.D. Moore,  G.V.  Alexander, T.-K.  Jan,  D. McDermott-Ehrlich,
R.P.  Eganhouse,  and  P.  Hershelman.    1978.    Trace  elements in  seafood
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104 pp.
                                    153

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    APPENDIX A
PHYSICAL ASSESSMENT

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                                 APPENDIX A
                            PHYSICAL ASSESSMENT
     The  primary  focus  of  this appendix  is  to  provide  guidance on  the
calculation  of initial  dilution and  trapping  depth.   For the  purpose  of
Section 301(h) evaluations,  "dilution"  is defined  as  the ratio of the total
volume  of  a  sample  (ambient   water  plus  wastewater)   to the  volume  of
wastewater in  that  sample.   A dilution of 100 to 1,  therefore, is a mixture
composed  of  99  parts  of ambient  water and  1 part of  wastewater.    The
calculation  of initial  dilution and trapping  depth  consists of  two  set  of
procedures:

     •    Calculate  the  port   flow  distribution   along  the  outfall
          diffuser(s) for the total  effluent flow rates of importance

     •    Compute  initial  dilution  and trapping depth   based  on  a
          characterization of the computed  port flow distribution,  the
          physical   characteristics   of  the   outfall   diffuser,   and
          receiving water density and current velocity profiles.

An important  variable in  both sets  of  procedures is  the total effluent flow
rate.   Historical data  should   be  used to  determine  the  minimum,  average,
highest 2-  to 3-h  average,  and maximum flow  rates  for  dry-weather,  wet-
weather,  and annual  average conditions.   The  adequacy of  the  diffuser's
hydraulic design  is  dependent on the  port flow distribution of the diffuser
during minimum and  maximum flow.  Characteristics of a  hydraulically well-
designed diffuser  are  described by  Grace (1978).  According  to the Section
301(h) regulations,  the critical (i.e., minimum)  initial  dilutions must  be
calculated  on the  basis  of the  highest  2-  to  3-h  average flow  rates.
Average flow rates, together with  average  receiving  water current speeds,
are commonly  used  to compute the trapping  depth used in effluent suspended
solids accumulation predictions.
                                    A-l

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     Port flow distribution along an outfall diffuser is commonly calculated
using computer  programs based on well-known  hydraulic  methods  (Grace  1978;
Fischer et  al.  1979).   This distribution depends  on the total  effluent flow
rate, the effluent  density,  the  density of seawater at the average diffuser
port depth,  and the physical specifications  of the diffuser.   The physical
specifications  include diffuser  pipe diameter,  depth,  and  port diameter and
type (i.e.,  bell-mouth or  sharp-edged)  for each  port  in the  diffuser.   In
the  event  that  the risers are  used instead of ports,  then  specifications
sufficient to compute  the discharge coefficient of the risers must be known.
These specifications include the diameter,  length, shape, type of transition
between the  riser pipe and  the diffuser pipe, number of ports,  and shape and
diameter of the ports  for  each  riser.   The report  of Koh  (1973) contains a
useful  method  for computing riser discharge  coefficients.   (The summary of
this method in  Fischer et  al.   (1979) contains errors.)    Head loss deter-
minations for  contractions, expansions, and bends  can  be  found in standard
engineering  and  hydraulics  texts   (Brater and  King  1976;  Daugherty  and
Franzini 1977).

     The  port  flow distribution  should  be  computed  for  the  minimum  and
maximum  flows to  ensure that  the  diffuser  is hydraulically  well-designed
(Grace  1978).    For any diffuser,  there  is a minimum  flow below  which  the
diffuser  is inoperable.   For  lower flows than the  minimum, not all  of the
ports flow  full  and the port flows from the diffuser can behave erratically
(Grace  1978).    On  a  sloping  bottom, the  minimum  operational  flow usually
increases with  increasing bottom slope.   Port  flows along the diffuser may
be  very  uneven on a sloping  bottom,  even  for  flows  above  the  minimum
operational  flow.    The hydraulic behavior of the  diffuser should  also be
checked to  investigate whether or not the  port flows vary greatly at maximum
flows.

     Initial  dilution   computations are  usually not performed  for each port
individually, but  rather on groups  of ports within which the port flows are
relatively  uniform.  The initial dilution and trapping depth for each group
of  ports  are then  computed based on the average port flow and port depth
                                     A-2

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within the group.   The  group  initial  dilutions  and  trapping  depths can then
be  group flow-rate  averaged to  obtain  estimates  of  the  average'initial
dilution and  trapping depth for the diffuser for a  specific total effluent
flow rate and set of receiving water conditions.  A common choice for a group
is a diffuser pipe  section, within  which  the diffuser pipe  diameter and the
diffuser port (riser) specifications are constant.

     .Initial  dilution   is  the  flux-averaged dilution  achieved during  the
period when  dilution is  primarily a  result of plume  entrainment.   It is
averaged over the cross-sectional area of the plume,  and characterized by a
time  scale  on  the  order  of minutes.   With proper location and design,
marine outfalls  can achieve  initial  dilution values of about 100 to 1 or
better before the  plume begins a transition  from essentially vertical flow
to  an  essentially  horizontal  flow  dominated  by  ambient  oceanographic
conditions.

     Adequate initial dilution  is necessary  to  assure compliance  with water
quality  standards.   The following  factors influence the degree  of initial
dilution that will be achieved:

     •    Discharge depth

     •    Flow rates

     •    Density of effluent

     •    Density gradients in the receiving water

     •    Ambient current speed and direction

     •    Diffuser characteristics

               Port sizes

               Port spacing
                                    A-3

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               Port orientation

               Port depth.

     Because  initial  dilution  calculations can be  strongly  dependent on the
vertical  gradient of  ambient  density,  larger applicants should  evaluate  a
substantial  amount of  data from both  the discharge site  and  nearby areas
that  have  similar environmental conditions  before  selecting  a  worst-case
density  profile  (i.e., the  profile  producing the  lowest initial  dilution).
Often the worst-case profiles  are  not the most stratified,  but  rather are
those  having  sufficiently  steep  density gradients  some  distance  [on  the
order of  5  m (16 ft)] above a diffuser port.  These profiles can usually be
identified  only  by computing  initial dilutions for several  or  all  of the
available density  profiles.  Because ambient  currents may affect the initial
dilution  achieved, a  modest amount of current (the lowest 10 percentile) can
be used  when predicting  initial dilution  for use  in determining compliance
with applicable water quality  standards and criteria.

     Five   numerical  mathematical   models  to  calculate   initial  dilution
(Muellenhoff  et   al.  1985a, 1985b)  are available from U.S.  EPA.   Charac-
teristics of  these models are  summarized below and in Table A-l:

     •    UPLUME  - Analyzes a single,  positively buoyant  plume  in an
          arbitrarily stratified stagnant  environment.

     •    UOUTPLM -  Analyzes  a single,  positively buoyant  plume in an
          arbitrarily stratified flowing environment.

     •    UDKHDEN  - Analyzes a multiport,  positively buoyant plume in a
          linearly stratified  flowing receiving water.
                                     A-4

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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
Direction e6
•
90°
45° < 9 < 135°
90°
0 < 9 < 180°
Port Type
Single
Single
Multiple
Multiple
Line
Density Profile
Type
Arbitrary
Arbi trary
Arbitrary
Arbitrary
Arbi trary

a From Table 1 of Muellenhoff et al.  (1985a).

b A current flowing perpendicular to the diffuser axis has current direction
e - 90°.  The widest range of possible angles is 0 to 180°.
                                    A-5

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     •    UMERGE  -  Analyzes either  positively or  negatively  buoyant
          discharges.   Analyzes a plume element through the history of
          its  trajectory and  dilution,  accounting for  the  effects of
          adjacent   plume  interference  in  a  receiving  water  with
          arbitrary  vertical density  and current variation.

     •    ULINE  - Treats discharges,  as  a line source  accounting for
          adjacent plume interference.  Can analyze positively buoyant
          discharges in an arbitrarily stratified receiving water with
          a current  flowing  parallel  or perpendicular to the diffuser.

     In  situ  observation  may  also be used to  determine  initial  dilution.
However,  if in  situ  observations are used, the applicant should demonstrate
that they represent  the lowest dilutions in center sections of the effluent
wastefield, not merely  a typical  dilution.

     Other mathematical  methods  available  in the published literature can be
adapted  for estimating initial dilution.   The following references describe
several  of these methods:    Abraham (1963,  1971);  Baumgartner  and  Trent
(1970);  Baumgartner  et al.  (1971);  Briggs (1969); Brocard  (1985);  Brooks
(1973);  Cederwall   (1971);  Davis  (1975);   Davis  and  Shirazi   (1978);  Fan
(1967);  Hinwood  and  Wall is (1985); Hirst (1971a,b); Isaacson et al. (1983);
Kannberg  and Davis (1976);  Koh  and Fan (1970);  Lee  and Cheung (1986); Morton
(1959);  Morton et al.   (1956);  Priestley  and Ball  (1955);  Roberts (1979);
Roberts  et  al. (1989a,b.c);  Rouse et al.  (1952);  Sotil  (1971); Teeter and
Baumgartner  (1979);  Wallace  and Sheff (1987);  Winiarski  and  Frick (1976);
and Wright  (1982).   Only flux-averaged  initial  dilutions should be used in
water  quality  computations.   Other  types  of  initial  dilutions,  such as
center!ine and minimum  surface,  must  be converted to flux-averaged.  Many of
the  above  investigations  provide ways  to estimate  flux-averaged initial
dilutions (see  Fischer  et al.  1979 for additional guidance).
                                     A-6

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                                 REFERENCES


Abraham,  G.   1963.    Jet  diffusion in  stagnant  ambient fluid.   Delft Hy-
draulics  Publication No. 29, Delft, Netherlands.  183 pp.

Abraham,  G.   1971.  The flow  of round buoyant jets issuing vertically into
ambient  fluid flowing in  a horizontal direction.   Delft  Hydraulics Publi-
cation No. 81, Delft,  Netherlands.  7  pp.

Baumgartner,  D.J.,  and D.S. Trent.   1970.  Ocean  outfall  design:   Part I.
Literature  review and  theoretical development.  U.S. Department of Interior,
Federal Water Quality  Administration,  Washington, DC.

Baumgartner,  D.J.,  D.S. Trent,  and K.V.  Byram.    1971.    User's  guide and
documentation for  outfall  plume  model.    Working  Paper  No.  80.    U.S.
Environmental   Protection   Agency,  Pacific   Northwest   Water  Laboratory,
Corvallis, OR.

Brater, E.F., and H.W. King.   1976.  Handbook of hydraulics for the solution
of  hydraulic  engineering  problems.  6th ed.   McGraw-Hill  Book Company, New
York, NY.

Briggs, G.A.   1969.   Plume rise.  U.S. Atomic Energy Commission, Oak Ridge,
TN.  81 pp.

Brocard,  D.N.    1985.    Surface  buoyant  jets  in  steady  and  reversing
crossflows.   ASCE J. Hydraul.  Eng. 111:793-809.

Brooks,  N.H.    1973.    Dispersion in  hydrologic  and coastal  environments.
EPA-660/3-73-010.  U.S. Environmental  Protection Agency,  Corvallis, OR.

Cederwall, K.  1971.  Buoyant slot jets into stagnant or flowing environment.
Report No. KH-R-25.  Cal.  Inst. of Tech., Keck Hydraulics Lab.  Pasadena, CA.

Daugherty, R.L., and J.B.  Franzini.  1977.  Fluid mechanics with engineering
applications.  7th ed.  McGraw-Hill Book Company, New York, NY.  564 pp.

Davis,  L.R.   1975.   Analysis  of multiple  cell  mechanical  draft  cooling
towers.   EPA-660/3-75-039.  U.S.  Environmental  Protection Agency, Environ-
mental Research Laboratory, Corvallis, OR.

Davis, L.R.,  and  M.A.  Shirazi.   1978.  A review of thermal plume modeling.
Keynote address.  In:  Proc. of the Sixth  International  Heat Transfer Conf.,
ASME, Aug. 6-11, 1978, Toronto, Canada.

Fan, L.H.  1967.  Turbulent buoyant jets into stratified and flowing ambient
fluids.    Rep.  No.   KH-R-15.    Cal.  Inst.  Tech., Keck   Hydraulics  Lab.,
Pasadena, CA.

                                    A-7

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Fischer, H.B.,  E.J.  List, R.C.Y. Koh, J.  Imberger,  and  N.H.  Brooks'.   1979.
Mixing in inland and coastal waters.  Academic Press, New York,  NY.   483 pp.

Grace, R.  1978.  Marine  outfall systems planning, design, and construction.
Prentice-Hall,  Inc., Englewood Cliffs, NJ.  600 pp.

Hinwood,  J.B.,  and  I.G. Wallis. .   1985.   Initial  dilution  for  outfall
parallel to current.  ASCE J. Hydraul. Eng. 111:828-845.

Hirst, E.A.   1971a.   Analysis of  round,  turbulent,  buoyant jets discharged
into  flowing  stratified  ambients.   Rep.  ORNL-4685.    U.S.  Atomic  Energy
Commission, Oak Ridge Nat. Lab., Oak Ridge, TN.

Hirst,  E.A.    1971b.   Analysis  of buoyant  jets within the zone of  flow
establishment.   Rep. N.  ORNL-TM-3470.   U.S. Atomic Energy Commission,  Oak
Ridge Nat. Lab., Oak Ridge, TN.

Isaacson,  M.S., R.C.Y.  Koh,  and  N.H.  Brooks.    1983.    Plume  dilution  for
diffusers with multiport  risers.  ASCE J.  Hydraul. Eng. 109:199-220.

Kannberg, L.D., and L.R. Davis.  1976.  An  experimental/analytical investiga-
tion  of  deep submerged multiple buoyant jets.   EPA-600/3-76-001.  U.S. En-
vironmental Protection Agency, Environmental  Research Laboratory, Corvallis,
OR.

Koh, R.C.Y.   1973.   Hydraulic test of discharge ports.  Technical Memorandum
73-4.  California Institute of Technology,  W.M.  Keck  Laboratory of Hydraulics
and Water Resources, Pasadena, CA.

Koh,  R.C., and L.N.  Fan.   1970.   Mathematical  models  for the prediction of
temperature  distribution resulting  from  the discharge  of heated  water in
large bodies  of water.   Water  Poll.  Cont.  Res. Series  Rep. 1613  ODWO/70.
U.S. Environmental Protection Agency.

Lee,  J.H.W.,   and  V.W.L.  Cheung.    1986.    Inclined  plane  buoyant  jet in
stratified fluid.  ASCE J. Hydraul.  Eng. 112:580-589.

Morton,  B.R.   1959.  Forced plumes.  J.  Fluid Mech.  5:151-163.

Morton,  B.R.,  G.I.  Taylor,  and J.S. Turner.  1956.  Turbulent gravitational
convection from maintained and  instantaneous sources,   pp. 1-23.  Proc. of
the Royal Soc.  of London, Vol. A234.

Muellenhoff,  W.P.,  A.M.  Soldate,  Jr., D.J. Baumgartner,  M.D. Schuldt,   L.R.
Davis, and W.E.  Frick.   1985a.  Initial  mixing characteristics of municipal
ocean discharges.   Volume  I  - procedures  and  applications.   EPA-600/3-85-
073a.  U.S. Environmental Protection Agency,  Narragansett,  RI.  90 pp.
                                     A-8

-------
Muellenhoff, W.P.,  A.M.  Soldate, Jr., D.J. Baumgartner, M.D.  Schuldt,  L.R.
Davis, and H.E.  Frick.   1985b.   Initial  mixing characteristics of municipal
ocean  discharges.    Volume  II  -  computer  programs.    EPA-600/3-85-073b.
U.S. Environmental Protection Agency, Narragansett, RI.  100 pp.

Priestley,  C.H.B.,  and  F.K.  Ball.   1955.   Continuous convection  from an
isolated source of heat.  Quarterly J. Royal Meteor. Soc. 81:144-157.

Roberts,  P.J.W.    1979.    A mathematical  model  of  initial  dilution  for
deepwater ocean outfalls,   pp.  218-225.   In:   Proceedings of  a Specialty
Conference  on  Conservation and  Utilization of Water  and  Energy Resources.
American Society of Civil Engineers.

Roberts, P.J.W., W.H. Snyder, and D.J. Baumgartner.  1989a.  Ocean outfalls.
I:  Submerged wastefield formation.  ASCE J. Hydraul. Eng. 115:1-25.

Roberts, P.J.W., W.H. Snyder, and D.J. Baumgartner.  1989b.  Ocean outfalls.
II:   Spatial  evolution  of submerged wastefield.   ASCE  J.  Hydraul.  Eng.
115:26-48.

Roberts, P.J.W., W.H. Snyder, and D.J. Baumgartner.  1989c.  Ocean outfalls.
Ill:  Effect of diffuser design on  submerged  wastefield.   ASCE J. Hydraul.
Eng. 115:49-70.

Rouse, H.,  C.S. Yin, and  W.G.  Humphreys.  1952.   Gravitational convection
from a boundary source.  Tell us 4:201-210.

Sotil, C.A.   1971.   Computer program  for slot buoyant jets into stratified
ambient environments.  Tech. Memo 71-2.  Cal.  Inst.  of Tech., Keck Hydraulics
Lab., Pasadena, CA.

Teeter,  A.M., and D.J. Baumgartner.   1979.   Predictions of initial dilution
for  municipal   ocean  discharges.    Environmental  Research  Laboratory  Pub.
No. 043.  U.S. Environmental Protection Agency, Corvallis, OR.

Wallace, R.B.,  and B.B.  Sheff.   1987.   Two-dimensional buoyant  jets  in  a
two-layer ambient fluid.  ASCE J. Hydraul.  Eng. 113:992-1005.

Winiarski,   L.D.,  and W.E.  Frick.    1976.    Cooling  tower  plume  model.
EPA-600/3-76-100.     U.S.  Environmental   Protection  Agency,  Environmental
Research Laboratory, Corvallis,  OR.

Wright,  S.J.  1982.   Outfall  diffuser behavior in stratified ambient fluid.
ASCE J.  Hydraul. Eng. 108:483-489.
                                    A-9

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       APPENDIX B
WATER QUALITY ASSESSMENT

-------
                                 CONTENTS
                                                                        Page
LIST OF FIGURES                                                         iii
LIST OF TABLES                                                           iv
INTRODUCTION                                                            B-l
B-I.  SUSPENDED SOLIDS DEPOSITION                                       B-2
     SMALL DISCHARGER APPROACH                                          B-2
     LARGE DISCHARGER APPROACH                                          B-6
B-II.  DISSOLVED OXYGEN CONCENTRATION FOLLOWING INITIAL DILUTION       B-15
B-III.  FARFIELD DISSOLVED OXYGEN DEPRESSION                           B-23
     SIMPLIFIED MATHEMATICAL MODELS                                    B-25
     NUMERICAL MODELS                                                  B-35
     EVALUATION OF FIELD DATA                                          B-36
B-IV.  SEDIMENT OXYGEN DEMAND                                          B-38
B-V.  SUSPENDED SOLIDS CONCENTRATION FOLLOWING INITIAL DILUTION        B-44
B-VI.  EFFLUENT pH AFTER INITIAL DILUTION                              B-48
B-VII.  LIGHT TRANSMITTANCE                                            B-53
B-VIII.  OTHER WATER QUALITY VARIABLES                                 B-61
     TOTAL DISSOLVED GASES                                             B-61
     CHLORINE RESIDUAL                                                 B-61
     NUTRIENTS                                                         B-62
     COLIFORM BACTERIA                                                 B-64.
REFERENCES                                                             B-68
                                    B-ii

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                                  FIGURES


Number                                                                  Page

  B-l   Projected relationships between suspended solids mass
        emission, plume height-of-rise, sediment accumulation,
        and dissolved oxygen depression for open coastal areas          B-3

  B-2   Projected relationships between suspended solids mass
        emission, plume height-of-rise, sediment accumulation,
        and dissolved oxygen depression for semi-enclosed
        embayments and estuaries                                        B-5

  B-3   Example of predicted steady-state sediment accumulation
        around a marine outfall                                        B-10

  B-4   Dissolved oxygen deficit vs. travel time for a submerged
        wastefield                                                     B-28

  B-5   Farfield dilution as a function of 12e0t/B2                    B-33
                                   B-iii

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                                  TABLES
Number                                                                  Page
  B-l   Example tabulations of settleable organic component by
        group and maximum settling distance by group                   B-12
  B-2   Example tabulations of deposition rates and accumulation
        rates by contour                                               B-13
  B-3   Typical IDOD values                                            B-17
  B-4   Dissolved oxygen saturation values                             B-21
  B-5   Subsequent dilutions for various initial field widths and
        travel times                                                   B-41
  B-6   Selected background suspended solids concentrations            B-46
  B-7   Calculated values for the critical effluent Secchi depth (cm)
        for selected ambient Secchi depths, initial dilutions, and a
        water quality standard for minimum Secchi disc visibility of
        1 m                                                            B-58
                                    B-iv

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                                INTRODUCTION


     This  appendix  provides  detailed  guidance  for  responding  to  water
quality-related  questions  in  the  Application Questionnaire.   Methods  for
predicting values of the following water quality variables are presented:

     •    Suspended solids deposition

     •    Dissolved oxygen concentration following initial dilution

     •    Farfield dissolved oxygen depression

     •    Sediment oxygen demand

     •    Suspended solids concentration following initial dilution

     •    Effluent pH after initial dilution

     •    Light transmittance

     •    Other water quality variables.
                                    B-l

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                     B-I.  SUSPENDED SOLIDS DEPOSITION
     The applicant must predict the seabed accumulation due to the discharge
of  suspended  solids into  the receiving water.  Two  prediction  methods  are
described  in  this  appendix.  The first  Is  a  simplified approach  for  small
dischargers only.    If this  method  is applicable,  then a  small  discharger
need not perform dissolved  oxygen calculations dependent on settled effluent
suspended  solids  accumulations.   The second prediction method is applicable
for both small and large dischargers.

SMALL DISCHARGER APPROACH

     Two  types  of  problems  (dissolved  oxygen  depletion  and  biological
effects)  and  two  types  of receiving  water environments (open  coastal  and
semi-enclosed bays or  estuaries) are considered in the following approach.

     Figure B-l  is  to be  used  for open  coastal  areas that  are  generally
considered well flushed.   The dashed line represents  combinations  of solids
mass emission rates  and plume heights-of-rise  that would result in a steady-
state sediment  accumulation  of  50  g/m2.  Review of  data  from several  open
coast discharges   has  indicated  that   biological effects  are minimal  when
accumulation rates were  estimated  to be below this  level.   Consequently, if
the applicant's mass emission rate and height-of-rise fall  below this dashed
line no further sediment accumulation  analyses are needed.   Applicants whose
charge  characteristics fall  above the line should conduct  a  more detailed
analysis of sediment accumulation discussed in the following section.

     The solid line  in Figure B-l represents a combination of mass emission
rates and  plume heights-of-rise  that were projected to result in sufficient
sediment  accumulation  to  cause  a 0.2 mg/L oxygen depression.   Applicants
whose discharge  falls  below  this solid  line need not  provide  any further
analysis of sediment accumulation as it  relates to dissolved oxygen.
                                     B-2

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    7000 r-
    6000
 $
 « 5000
   4000
   3000
    2OOO
    WOO
 *
 III


 "
             I
       02468101214161820

                         HEIGHT Of RISE, m
            STEADY STATE SEDIMENT ACCUMULATION LESS THAN 50g/m2
            DO DEPRESSION DUE TO STEADY-STATE SEDIMENT
            DEMAND > 012 mg/l
                                                     Raf»r»ne»: Tetra Tech (1982).
Figure B-1.  Projected relationships between suspended solid mass
            emission, plume height-of-rise, sediment accumulation,
            and dissolved oxygen depression for open coastal areas.
                          B-3

-------
     Figure  B-2  should be used  in  a similar manner for discharges to semi-
enclosed  embayments  or  estuaries.   Because  estuaries and  semi-enclosed
embayments  are  potentially  more   sensitive  than   open  coastal  areas,  the
critical sediment accumulation was  set at 25 g/m2.

     Methods described in Tetra  Tech (1982) were used to determine the mass
emission  rates and  heights-of-rise resulting in  the sediment accumulation
rates specified  above.   In  order  to use these methods, several  assumptions
were made.   A  current velocity of  5 cm/sec was assumed for the open coastal
sites  and  a  velocity  of  2.5  cm/sec  was assumed  for the  semi-enclosed
embayments.  these  velocities are  conservative estimates of average current
velocities over a 1-yr period.   The settling velocity (Vs) distribution used
is considered  typical  of primary or advanced primary effluents and is shown
below:

                      5 percent have Vs > 0.1 cm/sec
                     20 percent have Vs > 0.01 cm/sec
                     30 percent have Vs > 0.006 cm/sec
                     50 percent have Vs > 0.001 cm/sec

The  remaining  solids  settle so  slowly that  they  are  assumed  to  remain
suspended  in the water  column indefinitely.   The  effluent  is considered to
be 80 percent  organic  and  20 percent inorganic.   The above distribution is
based  on  the  review  of data  in  Section 301(h)  applications  and  other
published data (Myers  1974;  Herring and  Abati 1978).

     The  annual  suspended  solids  mass  emission rate  should  be calculated
using the  average flow  rate and an average suspended solids  concentration.
The  plume  height-of-rise,  determined   previously   in the  Initial  dilution
calculation, or  0.6 times  the water depth, whichever  is larger,  should be
used to enter  the appropriate figure (Figure B-l or B-2).
                                     B-4

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    4000
  g  3000

  O
  (A
  uj  2000
  M  1OOO
             J	I
I
         0     24    6     8    10   12   14   16   18   20

                           HEIGHT OF RISE, m
                STEADY STATE SEDIMENT ACCUMULATION LESS THAN 25g/m2
                DO DEPRESSION DUE TO STEADY-STATE SEDIMENT
                DEMAND > 0.2 mg/l
                                                       Reference: Tetra Tech (1982).
Figure B-2.  Projected relationships between solid mass emission, plume
            height-of-rise, sediment accumulation, and dissolved oxygen
            depression for semi-enclosed embayments and estuaries.
                              B-5

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LARGE DISCHARGER APPROACH

     The  approach  described  here  considers  the  processes  of  sediment
deposition,  decay  of organic materials,  and  resuspension.   However,  the
strictly quantitative prediction of seabed accumulation is based only on the
processes of deposition and decay.   Because resuspension is  not evaluated
easily using simplified approaches, the analyses described  in  this chapter
consider resuspension separately and  in  a more qualitative manner  that  is
based on measured near-bottom current speeds in  the vicinity of the diffuser.

Data Requirements

     To  predict seabed deposition rates of  suspended  solids,  the following
information  is  required:

     •    Suspended solids mass emission rate

     •    Current speed and direction

     •    Height-of-rise of the plume

     •    Suspended solids settling velocity distribution.

     The mass emission rate, M (kg/day), is:

                               M = 86.4(S)(Q)                            B-l

where:

     S "  Suspended solids concentration,  mg/L

     Q =  Volumetric  flow rate, m3/sec.

It  is  suggested that  the  applicant  develop  estimates  of  the suspended
solids mass  emission  rate for the  season  (90-day period) critical for seabed
                                    B-6

-------
deposition and  for  a yearly period.   If  the  applicant  anticipates  the mass
emission rate will  increase during the permit term,  the  mass  emission rate
at the end of the permit term should be used.

     Current-speed  data  are needed  to  determine  the  distance  from  the
outfall that  the sediments will  travel  before accumulating on  the bottom.
Consequently,  depth-averaged values  are  best,  if  available.    Otherwise,
current speeds near mid-depth may be sufficient.   The following current data
are needed for the assessment:

     •    Average value upcoast, when the current is upcoast

     •    Average value downcoast, when the current is downcoast

     •    Average value onshore, when the current is onshore

     •    Average value offshore, when the current is offshore.

If no current data are available, values of 5 cm/sec for longshore transport
and 3 cm/sec for onshore-offshore transport have been found to be reasonable
values.

     Plume trapping  levels  representative  of  the  critical  90-day period and
of the annual cycle  are  needed.   The applicant should use density profiles,
effluent volumetric flow rates,  and ambient currents characteristic of these
time  periods.    Extreme  values  should  not   be  used.   Usually the  annual
average and  critical  90-day average  flow rates  and  current  speeds (in the
predominant current  direction)  should be used.  The  expected  average plume
heights-of-rise  above the  seafloor  should   be  determined using  available
receiving water  density  profiles.   If large  numbers of  profiles  exist for
each month (or  oceanographic season), then the applicant  could  compute the
plume height-of-rise  above  the  seafloor  for each  of the available profiles,
and then average the  heights.   If relatively  few profiles are available for
each month,  then the applicant  could compute the plume  height  of  risk for
each profile and use  the  lowest  height-of-rise as  the average.   The monthly
                                    B-7

-------
average heights  of rise can then be  used to compute  the average  height-of-
rise for annual  and critical  90-day periods.  If so few profiles  exist that
It Is not possible  to determine whether differences exist between  months (or
oceanographlc  seasons),  then  the  applicant  should  use  the  lowest  plume
height-of-rise  (based  on  calculations  using the average effluent  flow and
current  speed)  as  the  average  height-of-rise  for  both  the  annual  and
critical 90-day periods.

     If  the  applicant  has  not determined  a  suspended  solids  settling
velocity distribution,  the following can be used based  on data  from other
Section 301(h) applications:

Primary or Advanced Primary Effluent              Raw Sewage

   5 percent have Vs >0.1  cm/sec          5 percent have Vs >1.0 cm/sec
  20 percent have Vs >0.01 cm/sec       20 percent have Vs >0.5 cm/sec
  30 percent have Vs >0.006 cm/sec      40 percent have Vs >0.1 cm/sec
  50 percent have Vs >0.001 cm/sec      60 percent have Vs >0.01 cm/sec
                                        85 percent have Vs >0.001  cm/sec.

The  remaining  solids   settle  so  slowly  that  they  are  assumed  to  remain
suspended  in  the  water column  indefinitely (i.e.,  they act  as  colloids).
Consequently,  50 percent  of the suspended  solids  in  a  treated effluent and
85 percent  of those in  a raw  sewage discharge are assumed to be settleable
in the ambient environment.

Prediction of Deposition

     Although  a  portion of the  settled solids is inert, primary concern is
with  the  organic  fraction of the  settled  solids.   For purposes  of this
evaluation,  composition  of the  waste discharge  can be assumed to  be as
fol1ows:
                                     B-8

-------
     •    80 percent  organic and 20 percent inorganic, for primary  or
          advanced primary effluent

     •    50 percent organic and 50 percent inorganic, for raw sewage.

     Accumulation  should  be predicted  for  the critical 90-day  period when
seabed deposition  is  likely to  be  highest and for  steady-state conditions
where average  annual  values are  used.   The results  should be  presented in
graphical  form,  as   shown   in  Figure  B-3.    Supporting   tables should  be
submitted with  the application.   The applicant must  exercise  judgment when
developing the  contours,  especially when  accounting  for rapid  depth  changes
offshore.  Sediment contours should be expressed in units  of g/m2, not as an
accumulation depth.

     An applicant  may  use a  proprietary or publicly  available  sedimentation
model.   Two widely  known models are those  of Hendricks   (1987), which  has
been  used  extensively offshore  of  Palos Verdes  Peninsula in  the  Southern
California Bight,  and Farley  (Tetra  Tech 1987),  which describes the Ocean
Data  Evaluation System  (ODES)  model  DECAL.   The model  DECAL  is  publicly
available through the U.S. EPA.  A simple model is described herein.   It can
be used to obtain acceptable estimates of sediment accumulation in a variety
of environments.   If  its  use results  in sediment  accumulations that lead to
violations  of  state   standards  or  federal  criteria  for receiving  water
quality,  an  applicant  may  use a   more sophisticated  effluent  sediment
accumulation model that better simulates the marine environment.

     The method described  below assumes that effluent sediment  particles
having  a  specific  particle  fall   velocity  settle  uniformly  within  an
elliptical  area.  This area  depends on  the  plume  height-of-rise relative to
the  seafloor (not  the port depth),  the particle  fall  velocity,   and  the
average currents speeds in four directions (upcoast,  downcoast, onshore,  and1
offshore) appropriate for an effluent  wastefield at the plume height-of-rise.
For  the  following sample calculations,  the  diffuser was  assumed  to be  a
point source.  Use of this assumption  may  not produce  reasonable estimates of
sediment accumulation  if the  diffuser  is long.   If the  diffuser  is long,
                                    B-9

-------
CONTOURS IN FEET
Figure B-3.  Examples of predicted steady-state sediment accumulation
            around a marine outfall.
                           B-10

-------
then estimates  of the sediment accumulation from each  diffuser  port can be
summed to obtain  an  estimate  for  the entire diffuser.   This sum is approxi-
mately the same as that obtained from assuming that the sediment accumulation
area is a ZIO-like area (with ends the same as the similar elliptical halves
computed  for a  single point discharge)  and  that  the effluent  suspended
solids having the specific particle fall velocity uniformly  settle  in this
area.  The  sediment  accumulation  due to the entire  discharge is the sum of
the accumulations for each particle fall velocity modeled.

     To  begin  computations  for   a  discharge   at   a  point  location,  the
applicant can  create a table similar to  Table  B-l, showing the  amount of
organic  solids  that  settle within  each  settling velocity  group,  and  the
maximum  distance  from  the outfall  at  which each  group settles.    If  the
applicant has current data for more  than  four quadrants, those  data can be
used.  The  maximum settling distances for  each  group  in each direction  are
calculated using the formula shown in the footnote of Table 6-1.

     With a sufficiently detailed map (e.g., a NOAA bathymetric chart), each
point 0}  through  0^5, or  Rj  through  R2Q»  can be plotted with the center of
the diffuser  as the  reference  point.  Depositional  contours are formed by
the  four points  that  define  the  perimeter of  a depositional field (e.g.,
0^030304).  The applicant  should  join these points  by smooth lines,  so that
the contours are  elliptically  shaped.   If  the  applicant has current data at
60°  or  30°  intervals,  instead of the  90° intervals  used  here, then  the
contours could be created more accurately.

     The  deposition  rates corresponding to each contour are  determined as
follows.   First, predict the deposition rate within each contour due to each
individual settling  velocity  group,  as  shown  in Table  B-2.   This quantity
is  Mi/Aj,  or  the group  deposition  rate   divided  by  the  area  within  the
contour.    The  area  within any contour is a function  of  the  four points
(e.g.,  Dj, D2,  03,  and 04), and  is denoted in the table by f(0^20304).  A
planimeter is probably  the most accurate method of  finding the  area.  Once
the deposition  rates by  group have  been  found, then  the  total  deposition
rate can  be  calculated by  summing all  contributing deposition  rates.   For
                                    B-ll

-------
                        TABLE B-1.  EXAMPLE TABULATIONS OF SETTlEAfllE ORGANIC COMPONENT
                                BY GROUP, AND  MAXIMUM  SETTLING OISVMCE BY GROUP
Mass Emission Rate - MT
Organic Component * Mo *
                              0.8 Mf, for primary effluent
                              0.5 My, for raw effluent
  Percent by Settling
Organic Component
Maximum Settlinfl Distance from Outfall
Velocity Group
Primary Effluent
5 (V. * 0.1 cm/sec)
15 (V » 0.01 cm/sec)
10 (V* * 0.006 cm/sec)
20 (V * 0.001 cm/sec)
by Group

0.04 NT
0.12 MT
0.08 MT
0.16 MT
upcoast Oowncoast Onshore

0, D2 03
Dj Dg Oy
D9 °10 °11
Offshore

D4
o8
                                    Sum » Q.40 M,
Rax Sewage
10
10
20
20
25


(VS

-------
                                              TABLE B-2.  EXAMPLE TABULATIONS OF DEPOSITION RATES AND ACCUMULATION RATES BY CONTOUR
CD
i
Organic Mass Com-
ponent by Group
Primary Effluent
0.04 M- = M.
0.12 MT " M2
0.08 MT = Mj
0.16 MT = M4
Rax Sewage
0.05 MT = MI
0.05 NT - M2
0.10 MT = Mj
0.10 MT = M4
0.125 MT = Mj
Mass Deposition Total Oroanic Deposition Rate 	 Accumulation (a/of )
Bottoa Area Rate, by Group within Area (g/nr/yr) SteaoV-State

A, - f(D1D2D3D4) M,/A, M^A^/A^/A^^ - f,
A, • fCOrO-O-D.) M,/A- M-/A-+M,/A.«M./A, » f, f,
2 56 IS f f c « i i 4 4 2 1
Aj * f(09D1QD1lD12) Mj/Aj Hj/Aj^^ - fj kd
A4 ' f(D13D14D15D16> VA4 VA4 ' f 4

A, « f(R1R2R3R4) M^A, M1/A1*M2/A2*M3/A3*M4/A4.M5/A5 - f,
Am f/0 D P R \ U /A U /A <44I /A All /A 4*1 /A n 4 f
A i\"C"i"T"O' "<%/"K "o/ "^^"^/ ^i^"/ /"/^"e/^c 'o * I
£ J O / O £ C ££OO%*t33 •> |
A^ * f ( RQK . »R 44^49) 3 i '^»/*5*''* / "**"c/"e ° * 5 *
Antf/DDDDl H / A U /A +M /A • f
A * IX 1A 1^ *. A* A* A A * A ' nC' ^^ A
Aaf/DDDD\ li/A U /A a f
5 17^ IS 19^20 5 'o O 5 5
90 Day


p [1-txp(-90kJ]



ji H-expC-Wk^l


      Note:  Units of fj are 9/0?/day.

-------
example, the Innermost contour receives contributions from all  groups*  while
the outermost contour receives a contribution only from one group.

     So far, only the rates of organic deposition (in units of g/m2/yr) have
been  predicted.   The  accumulation  of the  organic  material  (S-j)  can  be
predicted by including decay as follows:

                  .      fi
          Si  (g/mz) •   jp » at steady state
                          d
                                                                         B-2
          Si  (g/m2) -   ^   [1 - exp  (-90 kd)]t for 90 days.
                          d

The f-j  are  the deposition rates in  units  of g/mVday,  as contrasted to the
units of  g/m2/yr in Table B-2.  The decay rate constant,  k01)day x  [1-exp  (-90 x 0.01)j = 49 g/m2.    B-4
This example shows that  input data for the 90-day and steady-state accumula-
tions  are  different.   Consequently,  Tables B-l  and B-2  should  each  be
completed  twice.   Also  the accumulation over a  critical  90-day period can
exceed  the  steady-state   accumulation.    This  is  caused  by  short-term
deposition  rates  that  are considerably higher than  the  long-term average.
In  the example,  the maximum  90-day deposition  rate of  300  g/m2/yr would
eventually decrease  to values below  100  g/m2/yr,  so  that on a yearly basis
the deposition rate  is  100 g/m2/yr.

                                    B-14

-------
      B-II. -DISSOLVED OXYGEN  CONCENTRATION  FOLLOWING  INITIAL DILUTION


     When wastewater  is discharged through  a  single  port  or  a  diffuser, the
effluent  forms  a  buoyant  plume  that  entrains ambient water  as  it  rises.
Because the  initial  dilution  process occurs rapidly  (i.e.,  on  the order of
minutes), BOD exertion (a relatively slow process) is negligible during this
period.    However,  an  immediate dissolved   oxygen  demand  (IDOD),  which
represents  the  oxygen  demand  of  reduced  substances  that   are  rapidly
oxidized  (e.g.,  sulfides  to sulfates),  might  not  be  negligible.    The
dissolved oxygen  concentration following initial dilution can  be predicted
using the following expression:

                     D0f - D0a + (D0e - IDOD - D0a)/Sa                   B-5

where:

   DOf -  Final dissolved  oxygen concentration  of  receiving  water at the
          plume trapping level, mg/L

   D0a -  Affected   ambient   dissolved  oxygen   concentration   immediately
          upcurrent of the diffuser  averaged over the tidal  period (12.5 h)
          and from the diffuser port depth to the trapping level, mg/L

   D0e •  Dissolved oxygen of effluent, mg/L

  IDOD -  Immediate dissolved oxygen demand, mg/L

    Sa =  Initial  dilution (flux-averaged).

     The applicant should use  the least  favorable combination  of values for
effluent  dissolved  oxygen,  IDOD, affected ambient  dissolved   oxygen,  and
initial dilution.   The effluent dissolved oxygen  concentration  at the  point
                                   B-15

-------
of  discharge  from the  treatment plant  is often  0.0 mg/L.   Because  the
critical  case  is desired,  a  concentration  of  0.0  mg/L  is  a  reasonable
value.  However,  if data  show  that dissolved oxygen concentrations in  the
effluent  are greater than 0.0 mg/L during  the  critical  periods,  then  these
data may  be  used.

     The  IDOD values typically  vary  from 0 to  10  mg/L,  but can be  higher
depending  on  the level  of  treatment and  presence  of  industrial  flows.
Table B-3  can be used to select reasonable IDOO values.   Alternatively,  the
IDOD can  be  measured  as discussed below.  The influence of the effluent IDOD
on  ambient  dissolved oxygen  can  be  estimated  from the  following  table
(calculated  as  -IDOD/Sa):

               Contribution of IDOD to Lowering  of DOf  (mg/L)

                              	Initial Dilution
           IDOD (mg/L)

                 1
                 2
                 5
                10
                20

At  high  initial  dilutions,  the  IDOD contribution  is  small.   Thus,  the
expense of laboratory tests may  be unwarranted.   If IDOD is to be determined
experimentally,  the  procedures  in  Standard Methods  (American  Public  Health
Association  1985, p.  530)  should be  generally followed  except that  the
dilution  water  should  be  seawater   from  the  discharge   site  instead  of
distilled  water, and the effluent  sample should be  incubated  anaerobically
for a  length of time equal  to the travel  times  from  the plant  through  the
diffuser  for minimum, average,  and  maximum flow conditions.  The  effluent
sample  should  be mixed  with  the dilution  water  after  incubation.    The
dissolved oxygen concentration  of the effluent  and  dilution water should be
measured  separately  after  incubation and  before mixing  the samples.   The
dissolved oxygen of the mixture  should  be measured 15 min after preparation.
                                    B-16
10
-0.1
-0.2
-0.5
-1.0
-2.0
30
-0.03
-0.07
-0.17
-0.33
-0.67
50
-0.02
-0.04
-0.1
-0.2
-0.4
100
-0.01
-0.02
-0.05
-0.10
-0.20

-------
                      TABLE B-3.  TYPICAL IDOD VALUES

Treatment Level
Untreated or less
than primary



Primary








Advanced primary

Effluent
BODs, mg/L




50-100
50-100
50-100
100-150
100-150
100-150
150-200
150-200
150-200
<50
<50
Travel Time, mina
<60
60-200
200-300
>300
0-100
100-300
>300
0-100
100-300
>300
0-100
100-300
>300
0-60
>60
IDOD, mg/L
5
10
15
20
2
3
4
3
4
5
5
7
8
0
1

a Travel time should  include  the  total  travel  time from the treatment plant
through the diffuser, including any land portion of the outfall.

Note:  Information compiled from 301(h) applications.
                                     B-17

-------
     The IDOD Is calculated  using the following equation:
(00D)(PD)  + (S)(PS)  -
            - *
                        IDOD  - - - - 5 - * -                   B-6
                                         PS
where:

  IDOD -   Immediate dissolved oxygen demand, mg/l

   DOQ >   Dissolved oxygen  of dilution water (seawater), mg/L

    PQ *   Decimal  fraction  of dilution water used

     S -   Dissolved oxygen  of effluent after incubation, mg/L

    PS »   Decimal  fraction  of effluent used

           Dissolved oxygen  of mixture after 15 min, mg/L.
Several  dilutions should  be used,  preferably  close to the  actual  initial
dilution, unless  the  difference  between  the  initial  and mixed concentrations
is  less  than  0.1  mg/L.    All  data  used  in  the   above  calculations,  the
incubation  times,  and the computed results for each test should be included
in the application.

     The  lowest  initial  dilution  (flux-averaged)   should  be used  for  the
final dissolved oxygen calculation.  Usually, this  dilution will correspond
to  the  maximum  flow rate  at  the  end  of  the permit  term.   Low  initial
dilutions can  also occur  at smaller effluent  flow rates  if stratification is
sufficiently   severe.    Typically,  dilutions  Huring   periods  of  maximum
stratification should be  used for the final  dissolved oxygen  calculation.

     The  affected  ambient  dissolved  oxygen  concentrations   should  also
represent  critical  conditions.     Usually,  critical conditions  will  occur
                                    B-18

-------
during the maximum stratification period in the late summer or in the spring
                                                                    *
when  upwelling  of deep  ocean water occurs.   For existing discharges,  the
affected ambient data should be collected at locations directly upcurrent of
the diffuser, thereby  incorporating  the potential  effects  of  recirculation.
For proposed new  or  relocated discharges,  affected ambient dissolved oxygen
levels  upcurrent  of the  diffuser  should  be  estimated  from  mathematical
models  of  the discharge  or  by  extrapolation   from  similar  situations.
Dissolved oxygen data, as well as any ambient water quality constituent, may
be averaged between  the  depth of the discharge ports and the  plume trapping
level, which  corresponds to  the lowest initial  dilution  that was  used to
predict  the  final dissolved  oxygen  concentrations.    If  applicants use  a
mathematical  model that allows multiple vertical levels of input for ambient
water quality instead of an average value,  this should be noted.

     The time period over which ambient data  may  be averaged may depend on
specifications of intensity and duration factors in applicable water quality
standards.  For example,  if certain numerical values  shall not be compromised
over a period of 4 h, a 4-h average of input data may be reasonable.  Absent
any more stringent specification in locally applicable standards, an average
over  a  half tidal cycle (approximately 12.5  h)  would  provide  a generally
conservative estimate.

     The  affected   ambient  dissolved  oxygen   concentration   can  change
substantially as  a function of depth,  depending on environmental character-
istics and seasonal   influences (e.g., upwelling).   As the plume rises during
initial  dilution, water  from  deeper parts of  the  water column is entrained
into the plume  and  advected to  the  plume  trapping level.   If the dissolved
oxygen concentration is  lower in the bottom of the water column than at the
trapping  level,   the low dissolved  oxygen water  is  advected  to  a  region
formerly occupied by  water containing  higher concentrations  of dissolved
oxygen.   The result  is an oxygen depression caused by entrainment.

     This oxygen  depression  caused  by  the  waste discharge  and associated
entrainment  (ADOj)   should  be  computed as  the  difference between  DOf as
                                    B-19

-------
defined  in  Equation B-5  and  the affected ambient dissolved  oxygen  concen-
tration at the trapping depth  (D0t).

           ADOj  - D0f -  D0t - D0a -  D0t * (DOC_  -  IDOD - D0a)/Sa         B-7

The  oxygen  depression  of  the wastefield  relative  to  the  trapping  depth
expressed in percent  is  (-ADOi/DOt)lQO.

     For cases when the  effect of entraining low dissolved oxygen water can
be  neglected,  the  oxygen  depletion  (ADO?)  should be   computed  as  the
difference between the average affected ambient dissolved  oxygen concentra-
tion (D0a) in the  entrained water and OOf as shown below.

                  AD02 -  DOf  - D0a -  (D0e - IDOD - D0a)/Sa                B-8

The  oxygen  depletion  of the wastefield relative to the  average  affected
ambient dissolved  oxygen  concentration  is (-AD02/DOa)100.

     The equation  of  Baumgartner  (1981)  for the percentage depression is:

                               (D0f -  D00 -i- IDOD)
                                   D0t  x Sa	*

This equation can  be  derived by assuming that  D0a  - DO^  In Equation B-7.
Use of Equation  B-9 has  been  allowed  in the State of California.

     These  differences  can  be  described as  a percentage  of  the  ambient
concentration or as a  numerical difference, depending on the  requirements of
the state.  In some states, the  final dissolved oxygen concentration must be
above  a  specified limit  or must  be   converted  to  percent  saturation to
determine  whether  the  final concentration  is above  a  prescribed limit.
Dissolved oxygen saturation  can be  determined  as  a  function of temperature
and  salinity  using the  method of Green and Carritt  (1967)  and Hyer et al.
(1971)  as  tabulated  in  Table B-4.    The applicant may want to consult with

                                    B-20

-------
TABLE B-4.  DISSOLVED OXYGEN SATURATION VALUES

Dissolved Oxvaen Saturation. ma/L
Temperature
(° C) 20
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
12
12
12
11
11
11
11
10
10
10
10
9
9
9
9
8
8
8
8
8
8
7
7
7
7
7
7
7
7
7
7
.8
.5
.1
.8
.5
.3
.0
.7
.5
.2
.0
.6
.5
.3
.1
.9
.7
.6
.4
.2
.1
.9
.8
.7
.6
.5
.4
.2
.2
.1
.1
22
12.
12.
12.
11.
11.
11.
10.
10.
10.
10.
9.
9.
9.
9.
9.
8.
8.
8.
8.
8.
8.
7.
7.
7.
7.
7.
7.
7.
7.
7.
7.

6
3
0
7
4
1
9
6
3
1
9
6
4
2
0
8
6
5
3
1
0
9
7
6
5
4
3
2
1
1
1
24
12.5
12.2
11.9
11.5
11.3
11.0
10.7
10.5
10.2
10.0
9.7
9.5
9.3
9.1
8.9
8.7
8.5
8.4
8.2
8.0
7.9
7.7
7.6
7.5
7.4
7.3
7.2
7.2
7.1
7.0
7.0
Salinity (ppt)
26 28 30
12.3
12.0
11.7
11.4
11.1
10.8
10.6
10.4
10.1
9.8
9.6
9.4
9.2
9.0
8.8
8.6
8.4
8.3
8.1
8.0
7.7
7.7
7.6
7.5
7.4
7.3
7.2
7.1
7.0
7.0
6.9
12.1
11.8
11.5
11.2
11.0
10.7
10.4
10.2
9.9
9.7
9.5
9.3
9.1
8.9
8.7
8.5
8.3
8.2
8.0
7.9
7.7
7.6
7.5
7.4
7.3
7.2
7.1
7.0
7.0
6.9
6.9
12.0
11.7
11.4
11.1
10.8
10.6
10.3
10.1
9.8
9.6
9.4
9.2
9.0
8.8
8.6
8.4
8.2
8.1
7.9
7.8
7.6
7.5
7.4
7.3
7.2
7.1
7.1
7.0
6.9
6.9
6.8
32
11.8
11.5
11.2
10.9
10.7
10.4
10.2
9.9
9.7
9.5
9.2
9.0
8.8
8.7
8.5
8.3
8.1
8.0
7.8
7.6
7.6
7.5
7.4
7.3
7.2
7.1
7.0
6.9
6.9
6.8
6.8
34
11.7
11.4
11.1
10.8
10.5
10.3
10.0
9.8
9.6
9.3
9.1
8.9
8.7
8.5
8.4
8.2
8.0
7.9
7.7
7.6
7.5
7.4
7.3
7.2
7.1
7.0
7.0
6.9
6.9
6.8
6.8
36
11.5
11.2
10.9
10.7
10.4
10.1
9.9
9.7
9.4
9.2
9.0
8.8
8.6
8.4
8.3
8.1
8.0
7.8
7.6
7.5
7.4
7.3
7.2
7.1
7.1
7.0
7.0
6.9
6.8
6.8
6.7
                      B-21

-------
the state  water quality  agency  to determine whether any other methods  are
                                                                    i

used to determine compliance with the dissolved oxygen standards.
                                    B-22

-------
                B-III.   FARFIELD  DISSOLVED OXYGEN DEPRESSION
     Subsequent to Initial dilution, dissolved oxygen in the water column is
consumed  by  the  BOD  in the  wastefield.   The  effluent 800$  after  initial
dilution  is  needed to  estimate farfield dissolved  oxygen depletion.   The
final BODs concentration can be estimated using the following expression:
                       BODf -  BODa  -i-  (BODe  -  BODa)/Sa                    B-10

where:

  BODf =  Final 6005 concentration, mg/L

  BODa =  Affected  ambient BODs  concentration  immediately  updrift  of  the
          diffuser averaged over one-half the tidal period (12.5 h) and from
          the diffuser port depth to the trapping depth, mg/L

  BODe =  Effluent BODs concentration, rng/L

    Sa =  Initial dilution  (flux-averaged).

     This equation  provides an estimate of  the  total  BODs  concentration in
the receiving water.  The maximum contribution due to the effluent alone can
be determined  by dividing  the effluent BODs  concentration by  the  initial
dilution.   This  value is  used  later to  estimate farfield effects  of  the
effluent.   As a  critical  case, the  maximum monthly  average  effluent BODs
concentration  should  be  used with the  (monthly)  critical  initial dilution.
For existing  plants,  the  previous  12 mo of effluent  BODs  data  is  used to
support  the  selection of  a BODs  concentration.   For  proposed  or modified
treatment plants where  effluent  data  are  not  available,   monthly  average
influent BODs data  should  be  provided along  with the range  of daily  values.
                                    B-23

-------
The average removal  efficiency  for the new or modified plant is also needed
to compute estimated effluent BODs concentrations.

     Three  approaches  to assessing  farfield dissolved  oxygen demand  are
described below:

     •    Simplified  mathematical models  predicting  dissolved  oxygen
          depletions,  using  calculation  techniques  that do not require
          computer support

     •    Numerical models predicting dissolved oxygen  depletions, using
          a computer

     •    Evaluation  of  field  data,  using a  data-intensive  approach
          where  dissolved  oxygen concentrations are  measured  in  the
          water column  and compared to ambient concentrations.

     Before  undertaking  any  analysis  to determine  whether   farfield  BOD
exertion causes a violation  of the dissolved oxygen standard,  the applicant
should first check to  see whether:

                DO$TD < DOf - BODfu,  for critical  conditions             B-ll

where:

 DO$TD *  Dissolved oxygen standard

   DOf »  Dissolved  oxygen  concentration  at  the  completion  of  initial
          dilution

 BODfu «  Ultimate BOD  at the completion of initial  dilution  (- BODf x 1.46).

If  the  above  inequality is true,  then  the discharge will  not violate the
dissolved  oxygen  standard  due  to BOD  exertion and no  further analysis of
                                    B-24

-------
farfield  BOD exertion  is  required.   If the  Inequality  is  not  true,  then
further analysis Is required.

SIMPLIFIED MATHEMATICAL MODELS

     Oxygen  depletion  due  to coastal or  estuarine  wastewater  discharges 1s
primarily caused by exertion  of BOD,  although increased nutrient levels can
affect oxygen concentrations indirectly by altering algal photosynthesis and
respiration  rates.    BOD  consists  of a  carbonaceous component  (CBOD)  and
nitrogenous  component  (NBOD).    Both components can contribute  to  oxygen
depletion.  CBOD is often reported as BODs, the 5-day BOD.  Before using BOD
to predict  oxygen  depletion, the  applicant  should  convert  it  to BOD|_, the
ultimate BOD, by the following  relationship:

                              BODL -1.46 BOD5                          B-12

A typical decay rate  for CBOD is 0.23/day (base e)  at 20° C.  A temperature
correction should be made as follows:

                         kT - 0.23 x  1.047T-20/day                      B-13

where:

     kj »  BOD decay rate at temperature T (° C).

     NBOD might not always contribute to oxygen depletion.  If the applicant
discharges into open coastal waters where there are  no other major discharges
in the vicinity, the  background population of  nitrifying  bacteria might be
negligible.    Under  these  circumstances,  the  NBOD  will   not   be  exerted
immediately.   In more  enclosed  estuarine waters,  nitrification in the water
column has been documented  from numerous water quality studies.  Applicants
should  analyze  the  potential   impact  of NBOD,   if  they  discharge  into
estuarine waters.
                                    B-25

-------
     NBOD  can  be  estimated based  on  data  for  total  Kjeldahl   nitrogen
concentration  (the sum  of  organic  nitrogen and ammonia  nitrogen) in  the
waste discharge using the  following relationships:

                             NBODL -  4.57 (TKN)                          B-14

                             NBOD5 -  NBODL/2.54

where:

     TKN -  Total  Kjeldahl  nitrogen

   NBODL -  Ultimate NBOO

   NBODs *  5-day  NBOO.

The decay rate of  NBOO can be taken  as:

                         kT » 0.10 x 1.047T-20/day                      B-15

where:

     kj -  The decay rate  at temperature T  (° C)

   0.10 -  The decay rate  at 20°  C (base e).

     Simplified  mathematical models  are an acceptable alternative to  the
more complex  numerical  models.    In  the  simplest model  of oxygen depletion,
the following are  generally assumed:

     •    The  wastewater   plume  is  submerged  at   the completion  of
          initial  dilution for  critical   conditions  (so that  direct
          reaeration of  atmospheric  oxygen  into  the wastefield does not
          occur).

                                    B-26

-------
     •    Oxygen depletion is a function of distance from the discharge
          and  is  caused by carbonaceous oxygen demand  and  nitrogenous
          oxygen demand.

     •    The wastefield entrains ambient water as a function of travel
          time.    Lateral  dilution  is  the  predominant  mechanism  of
          entrainment.

If the  applicant  demonstrates  that the plume will  always surface,  then the
effects of atmospheric reaeration can be included; otherwise they should not
be included.

     When applying  a model that  predicts  farfield oxygen depletion,  it is
suggested that  the  applicant  plot dissolved oxygen depletion  as  a  function
of travel  time so that  the  behavior of dissolved  oxygen concentrations in
the wastefield can be examined to locate minimum values.

     Example oxygen depletion curves as  a  function  of travel  time are shown
in Figure B-4.  The  depletion  indicated  at time,  t=0, denotes the depletion
immediately  following  initial  dilution.    The  dissolved  oxygen  deficits
plotted in the figure are relative to the ambient concentration, and tend to
approach zero at travel times longer than those shown in the figure.

     For the three cases, the maximum deficits occur at the  following travel
times:

     •    0.0 days for Curve A

     •    Approximately 0.2 days for Curve B

     •    Approximately 4.0 days for Curve C.

The primary reason for the difference in magnitude and time  of occurrence of
the maximum  deficits is the IDOD, which  varies  from a high of 66  mg/L for
Curve A to  0.0 mg/L for Curve C.   When  the IDOD  is  66 mg/L (a high value,
                                   B-27

-------
        1.0 -
        0.9 -
        0.8 -
        0.7 -
    5  0.6 -
    2
    X  0.5 —
    o
    UJ  0.4 —

    I:;:
        0.1 —
        0.0
                    I         I        I
                    1        2        3
                    TRAVEL TIME (days)
CURVE
A
B
C
BODf
(ultimata)
(mg/L)
3.5
3.5
3.5
INITIAL
DO DEMAND
(rng/l.)
66.
44.
0.
Figure B-4.  Dissolved oxygen deficit vs. travel time for a submerged
           wastefield.
                       B-28

-------
but one  that could  be associated with  an unusual discharge),  the maximum
depletion  is  caused by  initial  mixing  processes,  and not by  farfield  BOD
exertion.   Conversely,  when  IDOD  is 0.0 mg/L,  the  maximum  depletion  is
caused by BOD exertion, and occurs at some distance from the discharge.

     The  simplified  farfield oxygen  depletion  model  for coastal  waters
suggested  herein  is  based  on an  approach developed, by Brooks  (1960)  for
 i                                     ...
predicting  wastefield  dilution   subsequent   to  initial   dilution.     The
dissolved oxygen concentration in the receiving waters can be expressed as a
function of travel time as follows:

                 D0f-D0a    L<-                 Lfn
   D0(t) - D0a +   Tn  * -  ^  l-exp(-k t) - fr11  l-exp(kt)          B-16
             a      us      us           c     us          n

where:

 D0(t) =  Dissolved  oxygen   concentration  in  a  submerged  wastefield as  a
          function of travel time t, mg/L

   D0a -  Affected   ambient   dissolved  oxygen   concentration   immediately
          updrift of the diffuser, mg/L

   DOf =  Dissolved  oxygen  concentration  at  the  completion  of  initial
          dilution calculated using Equation B-5, mg/L

    kc =  CBOD decay rate constant

    kn =  NBOD decay rate constant

   Lfc =  Ultimate CBOD concentration above ambient at completion of initial
          dilution, mg/L
                                    B-29

-------
   Lfn -  Ultimate NBOO concentration above ambient at completion of initial
          dilution, mg/L

    Ds -  Dilution attained subsequent  to Initial  dilution  as a function of
          travel time.

     The  above  equation expresses the  dissolved oxygen  deficit that arises
because of an initial deficit at the completion of  initial dilution (D0a-D0f)
plus that  caused by exertion of  BOD  in the  water  column.   The last term in
the above equation estimates the  exertion due  to NBOD.  The dissolved oxygen
deficit tends  to decrease  at longer  travel  tines  as a result of subsequent
dilution  and to  increase   as a  result  of BOD exertion.    Depending  on  the
particular case  being  analyzed,  one influence can  dominate the other over a
range  of  travel  times so  that  a minimum dissolved oxygen  level  can occur
either  immediately  following  initial  dilution  or  at a  subsequent  travel
time, as previously shown  in Figure B-4.

     To  predict  farfield oxygen  distribution,  one  must  determine  the
dilution  attained within  the wastefield  as  a  function of  time  following
discharge.   For open  coastal  areas,  dilution is  often  predicted  using  the
4/3 law  (Brooks 1960), which states  that the lateral  diffusion coefficient
increases as the 4/3 power of the wastefield width.  In mathematical form:
                                                                        B-17
                                   °\"/
where:

     e -  Lateral diffusion  coefficient,  ft^/sec

    c0 »  Diffusion  coefficient  when  L  =  b

     L »  Width of sewage  field  at any  distance from the ZID, ft

     b =  Initial  width   of sewage  field  (approximately  as  the  longest
          dimension  of the ZID),  ft.
                                    B-30

-------
The initial diffusion coefficient can be predicted from:
                              €0 - 0.001
Based on the 4/3 law, the centerline dilution, 0$, is given by:
                          1/erf
                                               -1
                                                   1/2
where:
     t -  Travel time, sec
   erf -  The error function.
B-18
B-19
     The 4/3  law is not  always  applicable,  especially  in  coastal  areas or
estuaries.    In  coastal  areas,  Grace  (1978}  suggests  that the  diffusion
coefficient vary linearly with L.   The subsequent dilution can  be expressed
as:
                    1/erf
                                                1/2
B-20
A  more conservative  choice  is  to  assume  the  diffusion  coefficient  is  a
constant.  The subsequent dilution can then be expressed as:
                      1/erf
                              116
B-21
                                    B-31

-------
     These  three equations  are cumbersome  to  use,  especially if  repeated
applications  are needed.   To  facilitate predicting subsequent  dilutions,
values of  Ds as a  function  of 12e0t/b2 are shown in Figure B-5  for  values
of Brooks'  n equal  to 0,  1, and  4/3.    For  example,  1f b - 100 ft,  and
t - 9,000 sec (2.5  h), then e0 - 0.464 ft2/sec and 12e0t/b2 - 5.0.  Assuming
that Brooks' n - 1, then use of Figure B-5 shows  that Ds -4.3 approximately.

     The figure  also  reveals that the predicted dilutions are  substantially
different,  depending  on  the relationship  obeyed  by the  lateral  diffusion
coefficient.   In some  instances,  the Brooks'  n - 1  law  might overestimate
subsequent  dilution,  even if  the  outfall is in coastal  waters.   To  attain
the subsequent dilutions  predicted  at large travel times, a large amount of
dilution water must be available.   Because many outfalls,  particularly small
ones, are not far  from shore, the entrainment  rate of dilution water can be
restricted  by the  presence of the shoreline and the  depth of the water.   As
the wastefield widens substantially,  the  rate of entrainment could decrease,
and neither the Brooks' n  - 4/3 nor the Brooks' n - 1 law may be obeyed.   It
is suggested that applicants  be conservative and base subsequent dilution on
a constant  lateral  diffusion  coefficient  (i.e.,  Brooks' n - 0), rather than
the Brooks'  n  - 1  or  Brooks'  n «  4/3 laws.   However,  if the  applicant  can
show  that   the  4/3 law  (or  some other relationship)  is   applicable  to  the
discharge site, then that  relationship should be used.

     If the applicant's discharge  is near  the  mouth  of a wide estuary,  the
approach just  discussed can  be  used directly to  predict oxygen  depletion.
If, however, the applicant discharges into a long narrow estuary,  then it is
likely that  the sides of the  estuary  will  limit the lateral dilution that is
attainable.   Under these  conditions, the maximum dissolved  oxygen deficit
with respect to saturation can be predicted as:
                            kW
                          A(k2-k)
                                                                        B-22
                                    B-32

-------
CD
u>
CO
                           16  -i
                           14  -
                           12  -
                           10  -
3   >H
UJ
C   6 -
DC

     4 "*"•
                            2 -
                                     	 n = 4/3
                                     	 n=1
                                     —*- ~<~r~m-L ™~ --~i n = 0
                                               I
                                               2
                                                \
                                                5
I
8
 I
10
                                                                 !2e0t/B2
                                                                                               Reference: Brooks (1060).
                 Figure B-5.  Farfield dilution as a function of 12

-------
where:

      D -  Dissolved oxygen deficit

      A -  Cross-sectional area of the estuary near the discharge site

      k *  CBOD decay  rate constant

     k£ -  Reaeration  rate constant

     E|_ -  Longitudinal dispersion coefficient

      W -  Mass loading rate  of CBOD.

The applicant  can  predict the deficits due to NBOD by using the appropriate
k and W values and  adding the two deficits to get the  total.  With reasonable
values for  the constants, the total  dissolved  oxygen deficit for discharge
to narrow estuaries becomes:

                       D - (3.14 Wc ^ 2.55 Wn) 10'4/A                    B-23

where:

      A »  Cross-sectional area in m^

     Wc -  Mass emission  rate of  CBOD, g/day

     Wn -  Mass emission  rate of  NBOD, g/day

      D -  Dissolved oxygen deficit,  mg/L.

The NBOD term  can  be added when data  are  available.
                                    B-34

-------
NUMERICAL MODELS

     Numerical  models   are   an   acceptable   method   of  predicting  oxygen
depletion caused by a discharge.  Numerical models may consider the combined
effect of  farfleld  demand In the water column,  as discussed  above, and the
oxygen demand associated  with organic  sediments.   If not,  the applicant may
have  to  augment  the  numerical  modeling  analysis   to address  unanswered
questions associated with sediment oxygen demand.

     The  applicant   should  try  to  isolate  the  impact of the outfall  on
dissolved oxygen concentrations  by considering that the applicant's discharge
1s  the  sole source of  oxygen depletion in  the  system being  modeled.   The
applicant  can  then  predict  the  dissolved oxygen depletion  caused  by  the
discharge  by  subtracting the background  dissolved  oxygen level  from those
predicted  by  the  model.   This  approach  also  simplifies the  applicant's
analysis because data from other wastewater sources are not required.

     Specific guidelines can be offered  to applicants who  choose  to  use
numerical models.   Typically, the most severe dissolved oxygen depletion due
to  BOD  exertion occurs when  the water column is density  stratified in the
presence of tidally reversing currents and  low nontidal   currents,  and the
wastefield remains submerged following initial dilution.  If such conditions
occur at  the  applicant's outfall  site,  then the numerical model  should be
layered  vertically,  with  a  minimum of two layers.   The plume  should be
discharged into the bottom layer  to simulate the submerged  discharge with
the consequence that  direct  atmospheric reaeration  is not present  in this
layer.

     The applicant  should set  up the grid  system  for the numerical  model
such that the smallest segments  are  located  in  the  vicinity of the diffuser
and gradually increase in size with  distance from the diffuser.  The volume
of the segments in the immediate vicinity of the diffuser  should approximate
the  volume of  the  ZID  in order to  prevent  an initial  dilution  that  is
artificially high and that would  cause  the model  to  underestimate dissolved
oxygen  depletion.    The  applicant  might  choose  to  experiment  with  grid
                                   B-35

-------
configuration by  starting with a coarse grid  and  then  decreasing  grid  size
until the model results do not significantly change.

     A  steady-state numerical model  will  be  acceptable for  the  dissolved
oxygen  analysis  because  dynamic  or  unsteady  analyses  are generally  more
costly, more  difficult to implement, and  require  more  data..  The  applicant
should  consider,  however,  whether  intratidal  variations  can  cause  more
severe depletions than are predicted  by a  steady-state model that calculates
average  oxygen  depletions  over  a  tidal   cycle.   Slack tide, for example,
might  be  critical because oxygen-demanding materials can  accumulate  in the
vicinity  of the  discharge.   For  existing discharges,  the  applicant  might
want  to  augment  the  steady-state  modeling   analysis  by  an  abbreviated
sampling  program  to determine dissolved oxygen depletions  during slack-tide
periods within  a tidal cycle.   Intratidal  variations  are  likely to be  more
important in enclosed  estuaries  than  along open coastal areas.

EVALUATION OF FIELD  DATA

     Extensive  field  data collection  and analysis  are  required  to  fully
implement this  third  approach.   Limited   samples  of  water  column  dissolved
oxygen  may  be  inadequate  to demonstrate compliance with  standards  under
critical  conditions.    Limited  information  should  be  supplemented  with
analyses  based  on numerical  or simplified  mathematical modeling.

     These  statements  should not  discourage  applicants from collecting and
submitting dissolved oxygen  data from the  vicinity of an existing discharge.
To the  contrary,  such  data,  if available, should  be submitted, particularly
if  the Section 301(h) application is for  a current  discharge or  for an
improved  or altered  discharge at the  same  location.  However, the data might
reveal  only a  portion of the  impact of  the  wastefield,  for  the following
reasons:

     •    The  location of the  maximum  oxygen depletion might  not be
          sampled.
                                    B-36

-------
     •    The  sampling  program could  have  been  conducted  during* a
          period that  was not  critical  with  respect to the  discharge
          or receiving water conditions.  Critical  discharge  conditions
          are  generally  associated  with high  effluent BOD  and  high
          volumetric flow  rates.   Critical  receiving  water  conditions
          are  usually   associated  with  minimum   initial   dilutions
          (maximum density stratification),  maximum water temperatures,
          and possibly slack-tide or low nontidal  current conditions.

     •    Ambient dissolved  oxygen  concentrations  can vary  spatially
          and  temporally  for  conditions unrelated  to the  discharge
          (e.g.,  upwelling effects).   Consequently, dissolved  oxygen
          depletions associated  with the discharge can  be  masked  by
          background variability.

     Some  applicants might  have  access to  dissolved  oxygen  demand  data
collected adjacent to another outfall at a nearby coastal area and attempt to
use those data to  show that their own  discharge will  not  violate dissolved
oxygen standards.   This approach can be, but is not always,  reliable.  The
applicants  should  include  in  the application  sufficient information  such
that the  data  collection  program  for the nearby area  can be reviewed,  and
then show that the  predicted  dissolved oxygen  depletions are  the  maximum
likely to  be produced   at  the  nearby discharge site.   The applicant  should
also demonstrate that the results of  the nearby discharge can be extrapolated
to the applicant's  discharge.   Essentially, the dissolved oxygen depletion
at the adjacent  discharge (due to both  BOD utilization and  sediment  oxygen
demand) will  need  to   be  at  least  as  severe  as that at the  applicant's
discharge.
                                    B-37

-------
                       B-IV.  SEDIMENT OXYGEN DEMAND
     The  oxygen depletion  due to  a steady  sediment  oxygen  demand can  be
predicted by:
                              SB  XM   -  a S kd XH                     R ,.
                            86,400 UNO   86,400 UHD                     b~"

where:

   ADO  -   Oxygen depletion, mg/L

    SB -  Average benthic oxygen demand over the deposition area, -g 02/mVday

    XM »  Length  of  deposition   area  (generally  measured  in  longshore
          direction), m

     H -  Average  depth  of  water  column  influenced   by  sediment  oxygen
          demand, measured  above bottom, m

     U -  Minimum sustained current speed over deposition area, m/sec

    kd -  Sediment decay rate constant, 0.01/day

     a =  Oxygen:sediment stoichiometric ratio, 1.07 mg 02/mg sediment

     S=  Average  concentration  of  deposited  organic  sediments over  the
          deposition area,  g/m?

     D =  Dilution  caused   by horizontal entrainment of  ambient  water as  it
          passes over the deposition  area  (always >1).

                                    B-38

-------
Both  S  and Xjyj can  be determined from  the  analysis performed in  the  Chap-
ter B-I on "Suspended Solids  Deposition."   Figure  B-4  in that chapter shows
an  example plot  of seabed deposition.   For  that example,  an  appropriate
estimate of S is the average of the maximum and minimum values, or

                                      - 52 g/m2                         B-25
The  distance XM,  measured  parallel  to  the  coast  and within  the  5
contour, is 8,000 m.

     The depth of water affected by the sediment oxygen demand is not really
a  constant  value  (as  suggested by  the previous  formula)  but varies  as a
function of the travel  time across the  zone  of deposition.   The affected
depth H  (in meters)  is chosen to  represent the average depth influenced by
the sediment oxygen demand and can be estimated as:


                                   sM1/2
                         H - 0.8 I -V*)                               B-26

where:

     ez -  Vertical diffusion coefficient (cm2/sec).

For the example case where U - 3 cm/sec, XM = 8,000 m, and ez « 1

               H . 0.8 x/l * MOO y 100y/2 x J. „ . 4.j .           „.„


     If the  applicant  desires to  compute  a value  of vertical  diffusivity,
the following empirical expression can be used:
                                    B-39

-------
                               z   1 d£
                                   p dz
where:

     €z «  Vertical diffusion coefficient, c

      p -  Ambient water density, kg/m3 (1,024)

        -  Ambient density gradient, kg/m4.
The  density  gradient used  should reflect  the most  severe  stratification
condition that  is  likely  to  occur  during the critical period.

     The dilution  D  that  is  used in Equation B-24 can be found from Table B-5
where  the  field  width   is  the width  of  the  deposition  area.    For  the
appropriate  travel time  and field width,  the  smaller of  the  two estimates
shown in the  table should be used.

     In  Chapter B-I  (Suspended Solids  Deposition),  the applicant  is asked
to compute  the  long-term accumulation and the critical 90-day accumulation.
Because the critical  90-day  accumulation might  exceed the long-term average,
the  applicant should  use the  more  critical  case when  predicting  sediment
oxygen demand.

Oxygen Demand Due  to Resusoension  of  Sediments

     It  is  more  difficult  to accurately  predict  oxygen demand   due  to
resuspension  than due to either  farfield BOD decay  or a  steady  sediment
oxygen  demand.    To  simplify the analysis,  the approach here  considers  a
worst-case  situation.   The amount of sediment to be resuspended  is equal to
the critical  90-day  accumulation,  which  is found  using the methods discussed
in the above  guidance on  "Suspended Solids Deposition."

                                    B-40

-------
              TABLE B-5.  SUBSEQUENT DILUTIONS* FOR VARIOUS INITIAL FIELD WIDTHS AND TRAVEL TIMES
Travel
Tine (h)
0.5
1.0
2.0
4.0
8.0
12
24
48
72
96
Initial Field Width (ft)
10
2.3/5.5
" : 3.1/13
4.3/32
6.1/85
8.5/>100
10/>100
15/>100
21/>100
26A100
29/>100
50
1.5/2.0
2.0/3.9
2.7/8.5
3.7/21
5.2/53
6.3/95
8.9/>100
13/>100
15/>100
18/>100
100
1.3/1.6
1.6/2.6
2.2/5.1
3.0/11
4.1/29
5.1/50
7.1/100
10/>100
12/>100
14/>100
500
1.0/1.1
1.2/1.3
1.4/1.9
1.9/3.5
2.5/7.3
3.0/12
4.2/30
5.9/80
7.3/>100
8.4/>100
1,000
1.0/1.0
1.1/1.1
1.2/1.5
1.5/2.3
2.0/4.4
2.4/6.8
3.4/16
4.7/41
5.8/73
6.6/100
5,000
1.0/1.0
1.0/1.0
1.0/1.0
1.1/1.2
1.4/1.7
1.6/2.3
2.1/4.4
2.8/10
3.4/17
3.9/24
* The  dilutions are entered  in the table as  N./H,,  where M. is  the  dilution assuning a constant diffusion
coefficient, and N2 is  the dilution assuming the A/3 law.
                                                    B-41

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     For the material  to remain  suspended,  the ambient current  speed has  to
be  sufficiently  great that  the  volume of water containing  the resuspended
material increases  over time as ambient water is  entrained.   It is assumed
that this process continues  for up to 24 h.

     The applicant  should compute the oxygen depletion as a function of time
during this period.  This can be done using the following relationship:

                                    S         /-k t
                              ADO -    [
where:

   ADO -.  Oxygen depletion, mg/L

    Sr »  Average  concentration  (in  g/m^)  of  resuspended  organic  sediment
           (based on 90-day  accumulation)

     H -  Depth of water  volume  containing resuspended materials, m

    kr -  Decay rate  of resuspended sediments,  O.I/day

     t =  Elapsed time following resuspension,  h  (t varies from 0 to 24 h)

     D =  Dilution as defined  previously  (generally set equal to 1).

     The variable H is a  function of  travel time  and can be predicted from:

                          H -lj§ (3,600  t €^1/2                       B-30

where:

   e^ »   Vertical  diffusion  coefficient  when  resuspension   is  occurring
           (5 cm2/sec)

     t =  Elapsed time following resuspension,  h.
                                    B-42

-------
The  applicant  should  check  to  be  sure that  H does  not  exceed the  water
depth.  If it does, set H equal to the water depth.

     The concentration  of resuspended  sediments  Sr can be approximated  as
the  average  concentration over the width  of the zone of deposition.   This
can be determined directly from  the contour plots  of sediment accumulation,
developed in response to the  guidance  on  "Suspended Solids  Deposition"  in
Chapter B-I.

     The applicant  should calculate  ADO for 3-h  increments  for a period of
up  to 24  h.   The  results  can  be  tabulated  as  shown  below.   Data  and
calculations should be included in the application.

                    t (h)                    DO (mq/Ll
                       0                          0
                       3
                       6
                       9
                      12
                      15
                      18
                      21
                      24                     predictions

Most often,  a maximum depletion will  occur  somewhere in the 24-h period, with
depletions decreasing for larger travel times.
                                    B-43

-------
      B-V.  SUSPENDED SOLIDS  CONCENTRATION FOLLOWING INITIAL DILUTION
     The  concentration  of suspended  solids at  the  completion  of  Initial
dilution should be calculated using  the following equation:
                                        SS   - SS
                             SSf - SSa
where:

   SSf -  Suspended  solids concentration at completion of initial dilution,
          mg/L

   SSa «  Affected   ambient  suspended   solids   concentration  Immediately
          upcurrent  of the diffuser averaged over ore-half the tidal period
          (12.5  h)  and from the  diffuser port  depth  to the trapping level,
          mg/L

   SSe -  Effluent suspended  solids  concentration, mg/L

    Sa =  Initial dilution (flux-averaged).

The maximum change,  AS, due to the effluent can be computed  as follows:

                                 AS = SSe/Sa                             B-32

where the terms  are  as defined above.   Equation B-32  is appropriate as long
as the  effluent  suspended solids  concentration  is  much  greater  than  the
background  concentration.    During  spring  runoff in some  estuaries,  the
background suspended solids concentration may exceed  the effluent concentra-
tion.   In  these cases,  the  final  suspended solids  concentration  will  be
below the background concentration.
                                    B-44

-------
     U.S. EPA  requires data for  periods  of maximum stratification  and  for
other periods when discharge characteristics, oceanographic conditions, water
quality, or biological seasons indicate more critical situations exist.  The
critical  period  generally  occurs  when  water  quality  standards are  most
likely to be violated.   If  the standard is expressed as a maximum numerical
limit, the  critical  period  would be when  the background concentrations  are
highest and the  initial  dilution  is  low.   If the standard is expressed as a
numerical difference  from  background, the  critical period  would  be  when
effluent  concentrations  are  high  and  initial  dilution  low.    When  the
standard is expressed  as  a  percent  difference  from background,  the critical
period could occur when background concentrations are low.

     Because   effluent   suspended  solids  concentrations  can   vary  with
discharge flow rate, the concentration at the completion of initial dilution
should be computed for the minimum,  average dry- and wet-weather, and maximum
flow rates,  using  the  associated  suspended solids concentration.   The range
and average effluent concentrations should be provided in the application by
month, unless  locally applicable standards require  compliance  over shorter
durations.  This information should be available from operating records.

     The selection  of an appropriate  background suspended solids concentra-
tion may be difficult due to  a general lack of data.   A common problem for
coastal sites  is that measurements may be available only  at the mouths of
large  rivers.    Concentrations  are  often higher  at  such locations  than
farther offshore  because of the solids contribution from  runoff.   Selected
values of background suspended solids concentrations are shown in Table B-6.
Suspended solids background data  should be obtained  at  control  stations, at
the ZID  boundary of  the existing discharges,  and at  stations  between  the
ZID-boundary and control  stations.  Data  should be collected over the tidal
cycle and at several depths so the average concentration over the height-of-
rise of the  plume over the tidal cycle can be calculated.  This value should
be used in Equation B-31.
                                    B-45

-------
      TABLE 8-6.  SELECTED BACKGROUND SUSPENDED SOLIDS CONCENTRATIONS
                                                      Suspended Solids
          Water Body                                Concentration, mg/L
Cook Inlet, AK                                          250-1,280
Southern California Bight                                0.7-60
Pacific Ocean near San Francisco, CA                      1-33
Broad Sound, MA                                         18.6-25.2
Massachusetts Bay near South Essex                      1.2-30.5
New Bedford Harbor, MA                                  0.4-6.1
East River, NY                                          6.0-25.6
Ponce, PR (near shore)                                    13.5
Puget Sound, WA                                         0.5-2.0
Outer Commencement Bay, Tacoma, WA                        33-51
Commencement Bay near Puyallup River, WA                 23-136
Tacoma Narrows, WA                                        33-63

Note:  Data are from 301(h) applications.
                                    B-46

-------
     Compliance with  the  water quality standard can  be  determined  directly
if the standard is expressed in the form of suspended solids  concentrations.
If only a general standard  exists,  the  maximum increase  due  to the  effluent
should  be  computed.    If the  increase is less  than 10  percent,  then  no
substantial  effect in the  water column is likely.  However, seabed deposition
could still  be substantial  depending on the mass  emission rate of suspended
solids  and  ambient  currents  at the  discharge  site,  and  thus should  be
evaluated.

     The water quality  standards may  also specify limitations  on the level
of suspended solids removal.  For example,  California has a requirement that
75 percent  of  the solids entering  POTWs must be removed.   Compliance with
this standard can be determined by estimating the average removal efficiency
for each month based  on the average monthly  influent and effluent suspended
solids concentrations.  The removal  efficiency should be  equal  to or greater
than the required percentage  in  all months.   The applicant  should include
the monthly  average  influent  and effluent suspended  solids  concentrations
along with the computed removal efficiencies.
                                   B-47

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                 B-VI.   EFFLUENT pH AFTLi INITIAL DILUTION
     The calculation of effluent pH following initial dilution is chemically
more sophisticated  than  other chemical  calculations  in  this  document.   This
appendix details  the basis for Table 1  in the  main  text showing the ranges
of  probable  effluent  pH  following  initial   dilution.    The  method  for
calculating  effluent  pH  following  initial dilution  is described  herein,
assuming  that all  of the required variables  are  known.   These variables
include initial dilution and the temperature,  salinity,  pH, and alkalinity of
the  effluent  and  the  receiving  water.     Effluent   and  receiving  water
temperature,  salinity, and pH  are normally  measured.   The (usually critical)
initial  dilution  is routinely  calculated as  part  of either  the  Section
301(h)  waiver  application  process  or  the  Section  301(h)   permit  renewal
process.  However,  neither the alkalinity of the receiving water nor that of
the effluent  is  usually  measured.   The alkalinity of seawater is relatively
constant,  however,  at a  value of 2.3  meq/L  (Stumm  and Morgan  1981).   The
alkalinity of effluent varies  from 0.1  to 6.0 meq/L.

     The method  described  herein predicts  pH at the completion of initial
dilution  of  an  effluent-receiving water mixture.     Because  the  initial
dilution process  occurs over  a  short  time period,  mixing  is considered to
occur  in  a  closed  system.    Also,  in  stratified  receiving  waters,  the
wastewater plume  is often  trapped below the  surface.   Thus,  the plume does
not equilibrate with the  atmosphere, and carbon dioxide exchange between the
atmosphere and mixture is considered negligible.   This  method is useful for
the calculation  of pH, alkalinity,  and total  inorganic  carbon concentration
in the plume  after  initial  dilution.

     The pH of  the  effluent receiving  water mixture  is  calculated using the
equations  for aqueous carbonate  equilibrium  in a closed  system (Stumm and
Morgan  1981).   For this  condition, the  five  equations that  describe the
relationships between  pH,  the  carbonate species, and alkalinity  are:
                                    B-48

-------
                              [HC03-]/[H2C03*] = K!

                               [C032-]/[HC03-] - K2
                                    [OH'] - Kw
                                      [HC03~] +  [C032-]
               Alkalinity - [HC03']  + 2[C032'] + [OH'] - [H+]
B-33

B-34

B-35

B-36

B-37
where:
   [H2C03*] =  The sum of aqueous C02 and true H2C03 concentrations

         Cf -  Total carbonate concentration.

The carbonate species can also be expressed  in terms of  ionization fractions
on, 01, and 02:
                              [H2C03*] = CT

                               [HC03-] = CT

                               [C032-] = CT
B-38

B-39

B-40
where:
                         °b
                                                    -1
                                                                         B-41
                                                   -1
                                                                         B-42
                                    B-49

-------
                                                   "
Substituting   the  hydroxide -hydrogen   Ion   relationship   and   ionization
fractions Into the alkalinity equation yields:

                                             Kw      +
               Alkalinity - CT (a, + 2aJ + —7- - [H*]                 B-44
                             '  • *    "      +
Because total  carbonate is conserved and oq  and  erg  are  functions  solely  of
pH, the above  equation has only one  variable:   hydrogen ion  concentration.
The model  solves  the equation to determine  the pH of the effluent-receiving
water mixture.  The  steps  involved in the calculations are listed below:

     •    Determine  input  data

     •    Calculate  ion product of water, 
-------
     •    Use  a  stepping procedure  to find pH  based on the  competed
          values  for  total  carbonate  and alkalinity  of  the  effluent-
          receiving water mixture

     •    Record results.

The Ion product and dissociation constants are calculated for the appropriate
temperature and salinity based  on  the  equations  given below.   The equations
for the  receiving  water have been revised  so that  salinity (in ppt) can be
used.
For effluent:
           3|4°7t7 + 0.03279T - 14.8435 (Kelts and Hsu 1978, p. 300)    B-45
     pK  - ***•  + 0.02379T - 6.498 (Kelts and Hsu 1978, p. 300)      B-46
           4 471 0
     PKW =  ' j*   + 0.01706T - 6.0875 (Stumm and Morgan 1981, p. 127)  B-47


For receiving water and the effluent-receiving water mixture:


     pKj = 3l4°4'7 + 0.03279T - 14.712 - 9.1575S1/3                     B-48
                              (Stumm and Morgan 1981, p. 205)


     pK2 => 2l9°2'4 + 0.02379T - 6.471 - 0.3855S1/3                      B-49
                              (Stumm and Morgan 1981, p. 206)


     PKW - 3l441>0 + 2.241 - 0.0925S1/2                                 B-50
                              (Dickson and Riley 1979, p. 97)
                                    B-51

-------
where:                  .





     T -  Temperature in degrees Kelvin





     S -  Salinity in ppt.





The receiving water equations are valid for salinities down to about 10 ppt.
                                    B-52

-------
                        B-VII.  LIGHT TRANSMITTANCE
     Increased  suspended  solids  concentrations  associated  with  municipal
discharges can cause a decrease In light penetration within the water column.
Reductions  in  light penetration can  result in a  decrease  in phytoplankton
productivity as  well  as a  reduction  in the areal distribution  of attached
macroalgae such as kelp.  Therefore, several states have enacted regulations
governing the allowable levels of interference with light transmittance.

     The  evaluation  of light  transmittance may require the  measurement  of
one or more  water clarity variables and a  comparison  of values  recorded  in
the vicinity of the outfall with those recorded in control  areas.  Variables
that are  widely measured  to  assess light  transmittance  include turbidity,
Secchi  disc depth, beam transmittance,  and  downward  irradiance.   While many
of the state requirements  are  very  specific in terms of the  light transmit-
tance measurements,  others leave the  selection  of the  sampling  methods  to
the discretion of the applicant.

     Turbidity  is a  measure  of the  optical   clarity of water, and  many
standards  are  written  in  terms of  Nephelometric  Turbidity Units  (NTU).
Measurements are made with a nephelometer, which provides a comparison of the
light-scattering  characteristics  of the  sample  with  a  standard reference.
Differences in the optical  design of  nephelometers can cause  differences  in
measured  values  even when  calibrated  against  the same  turbidity standard.
For this  reason,  caution must  be  exercised when  comparing measurements  of
turbidity made from different field sampling programs.

     A Secchi  disc is  used to make  visual observations of  water clarity.
Records of the depth at which  the  Secchi  disc  is  just barely visible can  be
used to   make  comparisons  of  light  transmittance  among  sampling  sites.
Measurements of Secchi disc depth are probably the most widely used means  of
estimating light  penetration.   The  Secchi  disc is easy  to use,  is accurate
                                    B-53

-------
over a wide range of conditions, and can be used to estimate the attenuation
coefficients  for collimated  and  diffuse  light and, therefore, to  estimate
the depth  of the euphotlc  zone.   However, since a wastewater  plume may  be
held below the  upper  regions of this zone during periods of stratification,
Seech1 disc measurements may  not be appropriate under all conditions.

     Beam transmittance  is  measured  with  a transmissometer  and  1s  a measure
of the  attenuation of a collimated  beam of artificial  light along a  fixed
path  length   (usually  1m).   The  attenuation is  caused  by suspended  and
dissolved  material  as  well   as  the  water  itself.    These  measurements,
therefore,  provide  information about  both the  absorption and  scattering
properties of the water.  The attenuation of a collimated beam of light in a
water path is described  by  the Beer-Lambert law:

                                 Td = e'od                              B-51

where:

    T(j -  The proportion of light transmitted  along a path of length d, m

     a -  Light  attenuation coefficient, m"1.

Measurements  of  beam transmittance are made in situ at any depth.

     The intensity and attenuation of daylight penetration are measured with
an irradiance meter,  which utilizes a photovoltaic cell  to record incident
light levels.   Measurements are made just below the surface and at selected
depth intervals  throughout the water column so  that  light  attenuation over
specific depths  can  be determined.   Unlike beam transmittance measurements,
irradiance  measurements  are  influenced   by   sunlight  as  well as  surface
conditions.

     Empirical  relationships  can be  derived  among the  light transmittance
variables  measured by these methods,  which permits  the estimation of one
based on  recorded values  of  another.   These  values can also  be  predicted
                                    B-54

-------
from suspended solids concentrations.  The derivation of these relationships
from existing  data,  in  some  instances,  may be sufficient to  allow  for the
demonstration of compliance with state standards.   Existing data can also be
used  to predict  the  transparency  characteristics  in  the  vicinity of  an
improved discharge.   Alternatively, a  sampling  program can be  designed  to
assess compliance with light transmittance standards based on such empirical
relationships.

     Where standards are written  in terms  of maximum allowable turbidity or
turbidity  increase,   predicted turbidity  in  the  receiving  water  at  the
completion of  initial  dilution can  be  used to demonstrate  compliance.   By
treating  turbidity  as  a  conservative  variable,  the  turbidity  in  the
receiving water at the completion of initial dilution can be predicted as:

                              T    T  x Te " Ta                         B-52
                              Tf • Ta * -IT"

where:

     Tf «• Turbidity in receiving water  at the completion of initial dilution,
          typically NTU  or Jackson Turbidity Units (JTU)

     Ta -Ambient or background turbidity

     Te - Effluent turbidity

     Sa - Initial dilution.

     Initial  dilution  can  be  predicted  based on  the methods  presented  in
Appendix A.  Equation B-52  can be  used, then,  to directly evaluate compliance
with  standards  written  in   terms   of   maximum  allowable  turbidity  or  a
turbidity increase.

     Laboratory experimental  work can also be used in lieu of field sampling
to demonstrate  compliance  with standards  written  in terms of an allowable
                                    B-55

-------
turbidity Increase.   These analyses consist of determining the turbidity of
a seawater-ef f 1 uent  mixture prepared  In  the sane proportions corresponding
to  the predicted  concentrations following  initial  dilution.   Experiments
should  be  conducted  to   simulate  worst-case  conditions.    Simulations  of
expected  receiving water  turbidity should  be  made  for periods  of highest
effluent  turbidity  (greatest  suspended  solids  concentrations)  as well  as
lowest initial  dilutions.   Values of the initial turbidity of the seawater,
the effluent  mixture, and the simulated  dilution  should  accompany all  test
results.

     By  deriving  a   relationship  between  turbidity  and  Seech 1   depth  and
utilizing  the method of  prediction  for turbidity  in  the  receiving  water
following  initial  dilution (Equation B-52), compliance  with state standards
written  in  terms of  Secchi  depth  can  be  evaluated.    Secchi   disc  and
turbidity can  be related in the following manner.  Assume that the extinction
coefficient of visible light (a) is  directly proportional  to turbidity (T)
and inversely  proportional to Secchi  disc (SO),  or:

                                  a = kj T                              B-53

and
                                                                        B-54
where kj  and  k£ are constants which need not  be specified since they cancel
out  in  further  calculations.    These  two relationships  have theoretical
bases, as discussed in  Austin (1974)  and Graham  (1966).  Combining those two
expressions,  the  relationship between  Secchi disc and turbidity becomes:
                                                                        B-55
When  state  standards are written  in  terms of Secchi disc, it is convenient
to combine  Equations  B-52  and B-55 to yield:
                                    B-56

-------
                                           j. SDo   S°a                  R «
                                 SDf - SDa * -«§	»          "        B-56
or
SO
                       e
             _
         SO.   SDa    a   SDa
                                                    -1
                                                                        B-57
where:
   SDf -  Minimum allowable Secchi disc reading In receiving water such that
          the water quality standard Is not violated

   SDa -  Ambient Secchi disc reading

    Sa -  Minimum initial dilution that occurs when the plume surfaces

   SDe -  Critical Secchi disc depth of effluent.

     In  this  manner,   the  critical  effluent  Secchi   depth   (SDe)  can  be
calculated.   An  effluent  reading  higher  than this  value indicates  that
standards will not be  violated.   This  method of predicting the final Secchi
depth in the  receiving water can be utilized  to provide  an estimate of the
effect  of  the wastewater discharge on  the receiving  water.   This method
should  only  be  used  where the  standard   is  exclusively  in  terms of  the
acceptable decrease in the Secchi depth.

     Values  of  the  critical  effluent Secchi  depth (SDe)  calculated  using
Equation B-57  are  presented  in  Table  B-7.    In  this  example,   the  water
quality  standard  for  the  minimum  Secchi  visibility  is  1  m   (3.3  ft).
Effluent having a Secchi depth greater than those presented for the selected
ambient  conditions  and  initial  dilution  will   not  violate  the  clarity
standard of  the  example receiving water.   Primary effluents  typically have
                                   B-57

-------
TABLE B-7.  CALCULATED VALUES FOR THE CRITICAL EFFLUENT SECCHI DEPTH (cm)
    FOR  SELECTED AMBIENT SECCHI  DEPTHS,  INITIAL DILUTIONS, AND A WATER
        QUALITY STANDARD FOR MINIMUM SECCHI  DISC  VISIBILITY OF 1 m

Initial
Dilution
10
20
40
60
100

2
18
10
5
3
2
Ambient
3
14
7
4
2
1
Secchi
4
13
7
3
2
1
Death (nO
5
12
6
3
2
1

10
11
6
3
2
1
                                    B-58

-------
Secchi disc  values of 5-30  cm  (2-12 in).   For this case, with  an,initial
dilution  greater  than 40  and  an ambient  Secchi  depth of  2  m (6.6  ft)  or
greater, these calculations indicate that the standard would not be violated.

     Since  Secchi  disc  measurements  are  made  from  the  water  surface
downward, critical  conditions  (in  terms of  the Secchi disc  standard)  will
occur when  the initial  dilution is just  sufficient  to allow the  plume to
surface.    It  is  notable  that  maximum  turbidity  or light  transmittance
impacts of a wastewater plume will occur when the water column is stratified,
the plume remains submerged, and initial dilution is a minimum.  Under these
same conditions, however,  Secchi disc readings  night  not  be altered at all,
if the plume is  trapped below the  water's surface  at  a depth exceeding the
ambient Secchi disc depth.

     The  ability  to  relate measurements  of turbidity  to the  attenuation
coefficient  (a) for collimated light has been demonstrated by Austin (1974).
The attenuation coefficient can be expressed in terms of turbidity as:

                                a = k x JTU                             B-58

where:

   JTU -  Turbidity, JTU

     k -  Coefficient of proportionality.

Combining Equations B-51 and B-58, turbidity can be expressed as:
                                                                        B-59
where:

     T(j =  Fraction of beam transmittance over distance d.

                                    B-59

-------
The coefficient  of  proportionality (k)  takes on values 0.5-1.0.   Therefore,
to utilize these relationships for demonstrating compliance with a turbidity
standard based on existing light transnrittance data,  the value of k must be
determined  empirically.   This  requires  simultaneous  measurements  of  beam
transmittance and determination  of turbidity covering  the complete range of
existing light  transmittance records.   If data are not available,  the "k"
value can be set equal  to  1  as a conservative  estimate.

     Where  a relationship  between suspended  solids concentration  and  beam
transmittance data  at a particular site can  be derived, the suspended solids
concentration at the completion of  initial  dilution from Equation B-31 can
be  used to  predict  compliance  with  standards written  in  terms  of  light
transmittance.
                                    B-60

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                   B-VIII.   OTHER WATER QUALITY VARIABLES
     Other  variables  for  which  water  quality  standards may  exist  Include
total  dissolved gases,  coliform  bacteria,  chlorine  residual,  temperature,
salinity, radioactivity,  and nutrients.   Variables  concerned with aesthetic
effects  that  also may be  included  are color,  floating  material,  taste and
odor,  and  hydrocarbons  (i.e.,  grease  and  oil).    For most  dischargers,
temperature,  salinity,  and  radioactivity   standards are   unlikely  to  be
violated.    Aesthetic effects  are  more likely  to  occur  when  the  plume
surfaces  and  the dilution is low.   Compliance  with aesthetic standards can
best be  checked by field  observations at the discharge site  and  along the
shore.

TOTAL DISSOLVED GASES

     Several states have a limit for total dissolved gases of 110 percent of
saturation.   Supersaturation of dissolved gases  is not considered to  be a
likely problem for municipal wastewater discharges to the marine environment
and is not discussed further.

CHLORINE RESIDUAL

     Chlorine residual  standards  may be expressed  as  a  concentration limit
in  the effluent  or  as  a  maximum concentration  in the  receiving water at
the completion of initial  dilution.   If the  effluent is  not chlorinated, no
further  information  is  required.    If  the  standard  is  expressed  as  an
effluent  limit,  chlorine  residual   data from  treatment  plant  operating
reports,   or  other sources,  should be  presented in the  application.   If no
data  are available,  then  the procedure  for  chlorination,  including  the
compound  used, quantity, and occurrence of any  operational  problems,  should
be  described.    If the  standard is expressed as  a  maximum  limit  at  the
                                    B-61

-------
completion  of Initial  dilution,  the concentration in the  receiving^ water,
assuming the  ambient  concentration is 0.0 mg/L, can be estimated as follows:

                                Clf = C1e/Sa                            B-60

where:

   Clf -  Chlorine residual  at completion of initial dilution, mg/L

   Cle -  Chlorine residual  in effluent, mg/L

    Sa -  Lowest flux-averaged initial dilution.

As  a worst-case  approach,  the  maximum observed  chlorine  residual  in  the
effluent  should  be  used with  the  lowest dilution.    If  violations  are
predicted,  the  applicable water quality standard may require information on
the frequency of occurrence.

NUTRIENTS

     Standards can be expressed  as maximum  receiving water concentrations of
total  nitrogen  or total  phosphorus  or as  a  general  prohibition on amounts
that  would   cause  objectionable  aquatic  life.     In  general,  for  small
discharges  when  the  initial dilution  is  large,  nutrients  are not likely to
cause problems.  Appropriate state agencies should be contacted to ascertain
if  algal  blooms,  red tides,  or  other  unusual  biological   activity  have
occurred near the discharge  site in  the past.

     Receiving  water  and effluent  nutrient  data can  be used  to estimate
concentrations  at  the  completion  of  initial   dilution.     For  screening
purposes,  the  nutrients   can  be  treated  as  conservative  variables.   The
concentration is estimated as  follows  in  a  similar  manner  to  suspended
solids:
                                    B-62

-------
                                        c  - c
                                        --1                         B-61
where:

    Ca •  Affected ambient  concentration  immediately upcurrent of diffuser,
          mg/L

    Ce •  Effluent concentration, mg/L

    Sa •  Initial dilution  (flux-averaged)

    Cf -  Concentration at  the completion of initial dilution, mg/L.

The predicted concentration can then be compared to the state standard.

     Because water  quality criteria are often  prescribed  as  maximum values
not to be exceeded following initial dilution, it is useful to rearrange the
above  equation  to express  the  maximum allowable effluent  concentration as
follows:

                       (Ce)max -  Ca. + (Sa)min  (Cc-Ca)                    B-62

where:

    (Ce)max -  Maximum  allowable  effluent  concentration   such  that  water
               quality criteria are not exceeded

         Cc •  Applicable water quality criterion

    (Sa)min =  Minimum expected initial dilution.

The maximum  observed  effluent  concentration  can  then be  compared to  the
predicted  allowable   concentration.    This  approach  can  be  used  for  any
conservative constituent.   Thus,  if  other  specific limits  exist  such as
                                    B-63

-------
for color,  effects  due  to  the  discharge  can  be  determined  as  shown  in
Equations B-61 and B-62.

COLIFORM BACTERIA

     Standards may exist  for total or fecal collform bacteria or enterococci
and are usually  expressed as a mean or median bacterial count and a maximum
limit that  cannot be exceeded  by more  than 10 percent of the  samples.   If
the effluent is  continuously disinfected using chlorination or an equivalent
process,  analyses for  coliform bacteria may  be  needed only to verify  the
effectiveness  of disinfection.   If  disinfection  is done part  of  the year,
analyses should  be  representative of conditions  when  the  effluent  is not so
treated.   The chemicals  used, quantities,  and  frequency of use  should be
provided along with  a discussion  of  the reliability of the system.

     The coliform bacteria count at the completion of  initial  dilution  due
to the discharge can be estimated as follows:

                                 Bf = Be/Sa                             B-63

where:

     Be -  Effluent  coliform bacteria count, MPN/100 ml

     Sa -  Initial dilution.

As  a conservative  approach,   the  maximum  effluent  count  and the  lowest
initial  dilution should  be  used.   If onshore currents occur only during a
particular season,  the  coliform count at the completion of initial dilution
can  be  estimated  using  the  lowest initial  dilution appropriate  for that
season.    Effluent coliform  data  should be  submitted  to  support the appli-
cant's  values.    The predicted value  can  be  compared  with  the appropriate
standard at  the  ZID boundary.  This value can also be used to estimate the
bacterial concentration at  specific  locations  away  from the ZID.
                                    B-64

-------
     Because different  limits  may apply to specific areas (e.g., shellfish
harvesting areas, beaches, diving areas),  the maximum bacterial  count at a
specified distance  from the discharge  may be of  concern.   This bacterial
count can be estimated in a manner  analogous to the estimation of the BOO
exerted as the  wastefield  spreads out from the  ZID.  The maximum bacterial
count at the centerline of the wastefield  can be estimated as  a  function of
distance from the discharge as  follows:

                                   Bf '  Ba
                         Bx ' Ba * T^                              B'64

where:

    Bx -  Bacteria count at distance x from ZID,  #/100 ml.

    Ba -  Affected ambient bacteria count immediately upcurrent of diffuser,
          #/100 mL

    Bf a  Bacteria count at completion of initial dilution, #/lQQ ml

    Ds =  Dilution attained subsequent to initial dilution at distance  x

    05 =  "Dilution"  due   to  dieoff  of  bacteria   caused  by  the  combined
          effects of exposure to seawater and sunlight.

when x  - 0,  Bx -  Bf.   In cases where the  background  bacterial  count  is
negligible or the effect  of the  discharge alone is desired,   the terms  for
the ambient  bacterial count can be dropped, simplifying  Equation  B-64  to:


                                   B*'5A

Values  for  subsequent  dilution  as a  function  of  12e0t/B2  in  Figure B-5.
Guidance is  included in Chapter B-III  ("Farfield Dissolved Oxygen Demand")

                                   B-65

-------
on methods  for estimating  subsequent  dilution for sites located in^ narrow
estuaries or bays.

     The  decay  rate  of  bacteria  in  the  ocean  is  Influenced  by  water
temperature, incident light, salinity, and other factors.  As a conservative
estimate, the  minimum  decay  rate should be  used.   If  no violations  would
occur, then further  calculations  are not  needed.   Flocculation and  sedimen-
tation can cause an  apparent decrease in coliform count in the water column,
but the  bacteria are retained  in the sediment.  Thus,  this  process  is  not
included in the above approach.   If  the applicant has information indicating
that the decay rate at the discharge  site  should be a different value,  the
revised decay  rate  may be used.   The evidence for  the  revised decay rate,
including any  data or results of  laboratory tests, should be included in  the
application.

     In  this  report,  dieoff  due to  the combined  effects  of  exposure  to
saltwater and  exposure  to  sunlight  only  are  considered.   The dieoff due to
exposure to saltwater,  Dsw, and the  dieoff due to exposure to sunlight, Ds-j,
are (Gameson and Gould  1975):

                              Dsw =  exp(kswt)                           B-66

                              Osl  = exp[al(t)]                           B-67

where:

   ksw -  Bacteria decay  rate due to exposure  to  saltwater, 1/h

     a -  Constant,  m2/MJ

  I(t) =  Total  intensity of  sunlight  received  by  bacteria during  the
          travel time,  MJ/m2

     t =  Travel time,  h.
                                    B-66

-------
The bacteria dieoff due to the combined effects of saltwater and sunlight is
Db "  Dsw°s1-   Gameson and Gould (1975) indicate that a • 1.24 m2/MJ in situ
for Dorset, England seawater.    The total  intensity of sunlight received at
the water  surface  can be  measured,  or estimated using site-specific data or
general methods  (Wallace  and Hobbs 1977).   If the  wastefield is submerged,
then  the  calculation of  the  total  sunlight  received  should  reflect  the
effect of  turbidity on light transmission from the sea surface to the top of
the wastefield.

      The bacteria  decay  rate due to  the exposure to saltwater Is known for
both  coliform bacteria and enterococcus bacteria.  For coliform bacteria,

                ksw - 2.303 exp[(0.0295T - 2.292)2.303] / h             B-68

where T  -  water temperature (°  C),  based  on field  measurements at Bridport
(Dorset, England)  (Gameson and Gould 1975).   The enterococcus bacteria dieoff
rate  due to exposure  to saltwater is:

                           ksw - 0.5262 / (24 h)                        B-69
at  a  temperature of  20°  C (Hanes and  Fragala 1967).   [It  should be noted
that Hanes  and Fragala (1967) determined that ksw  for coliform bacteria is
0.0424/h  at 20° C, a value slightly smaller  than the  value  of 0.0457/h at
20° C based on the formula  from Gameson and Gould (1975).]

     The  estimated coliform  count at  the  location  of interest  should be
compared to the applicable  standard.  If a violation  is predicted, the water
quality  standards may require  that  the  approximate  frequency  should be
discussed based on the percentage or likelihood of currents transporting the
wastefield  in the direction of interest.
                                    B-67

-------
                                 REFERENCES


American  Public  Health  Association.    1985.    Standard  methods  for  the
examination  of water and wastewater.  APHA,  Washington, OC.   16th  Edition.
1268 pp.

Austin,  W.R.   1974.   Problems  in measuring  turbidity  as  a  water  quality
parameter.    EPA-600/4-74-004.    pp.  23-54.    In:    Proc.   on  Seminar  on
Methodology  for Monitoring  the Marine Environment.

Baumgartner, D.   1981.   Environmental  Protection Agency, Office  of  Research
and Development,  presentation at 301(h) Task Force Meeting.   13 March 1981.

Brooks,  N.H.   1960.   Diffusion of sewage effluent in an ocean current,  pp.
246-267.   In:   Proc. of  the 1st International Conference on  Waste  Disposal
in  the  Marine Environment,  University  of  California,  Berkeley,  CA,  July
1959.  Pergamon Press,  Elmsford, NY.

Dickson,  A.G.,  and J.P. Riley.   1979.   The estimation of acid dissociation
constants in seawater media from potentiometric titrations with strong base;
I.  The  ionic  product of water-^.  Mar. Chem. 7:89-99.

Gameson,  A.L.M.,  and D.J.  Gould.   1975.   Effects of solar  radiation on the
mortality  of  some  terrestrial  bacteria  in  seawater.   pp.  209-219.   In:
Discharge of Sewage  from Sea Outfalls.   Proc. of an International  Symposium
held at  Church House, London, 27 August to 2 September 1984.  A.L.M.  Gameson
(ed).  Pergamon Press,  Oxford, UK.

Grace, R.  1978.   Marine outfall systems planning, design,  and construction.
Prentice-Hall, Inc., Englewood Cliffs, NO.  600 pp.

Graham,  J.J.   1966.  Secchi disc observations  and extinction coefficients in
the central  and eastern North  Pacific Ocean.   Limnol. Oceanogr. 2:184-190.

Green, E.J.,  and  D.E.   Carritt.   1967.   New tables for oxygen saturation of
seawater.  J.  Mar. Res. 25:140-147.

Hanes,  N.B., and  R. Fragala.   1967.   Effect of  seawater  concentration on
survival of  indicator bacteria.  J. Water  Pollut. Control Fed. 39:97-104.

Hendricks, T.J.   1987.  Development of methods for estimating the changes in
marine sediments  as a  result of the discharge  of sewered  municipal waste-
waters through  submarine  outfalls.   Part I -  sedimentation  flux estimation.
Final Report.  Prepared for U.S.  Environmental  Protection Agency, Environmen-
tal  Research  Laboratory,   Newport, OR.   Southern California  Coastal Water
Research Project  Authority, Long Beach, CA.  65 pp.
                                    B-68

-------
Herring,  J.R.,  and  A.L.  Abati.    1978.    Effluent  particle  dispersion.
pp. 113-125.   In:   Coastal Water Research Project  Annual  Report.  'Southern
California Coastal Water Research Project,  El Segundo, CA.

Hyer, P.V.,  C.S. Fang, E.P.  Ruzecki,  and  W.J. Hargis.  1971.   Hydrography
and hydrodynamics of  Virginia estuaries.   II.   Studies  of the distribution
of  salinity  and dissolved  oxygen  in the  upper  York  system.    Virginia
Institute of Marine Science, Gloucester Point,  VA.  167 pp.

Kelts, K., and  K.J. Hsu.   1978.   p. 295+.   In:  Lakes:  Chemistry, Geology,
Physics.  Lerman, A.  (ed).  Springer, New York, NY.

Myers, E.P.   1974.   The concentration and isotrophic composition  of carbon
in  marine  sediments  affected  by  a  sewage  discharge.     Ph.D.  thesis.
California Institute of Technology, Pasadena, CA.  179 pp.

Stumm, W., and J.J. Morgan.  1981.  Aquatic chemistry.  John Wiley and Sons,
Inc., New York.  780 pp.

Tetra  Tech.    1982.   Revised  Section 301(h)  technical  support  document.
EPA-430/9-82-011.  U.S. Environmental Protection Agency,  Washington, DC.

Tetra Tech.   1987.  A simplified deposition  calculation  (DECAL) for organic
accumulation near marine outfalls.   Final Report.  Prepared for U.S. Environ-
mental  Protection  Agency,  Office  of  Marine  and  Estuarine  Protection,
Washington, DC.  Tetra Tech, Inc., Bellevue,  WA.  49 pp.  + appendices.

Wallace, J.M., and P.V. Hobbs.  1977.  Atmospheric science:  an introductory
survey.  Academic Press, New York NY.  467 pp.
                                    B-69

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     APPENDIX C
BIOLOGICAL ASSESSMENT

-------
                                 APPENDIX  C
                           BIOLOGICAL ASSESSMENT
     Because  benthic  infauna  are  sedentary  and  must  adapt to  pollutant
stresses  or perish,  this  assemblage  is  often used  to define  the  spatial
extent  and  magnitude of biological  impacts  in the vicinity  of  sewage dis-
charges.   The general changes  in  benthic community  structure and  function
that occur  under conditions of  organic  enrichment of the  sediments  (e.g.,
due  to  municipal sewage  effluent)  have  been  well documented (Pearson  and
Rosenberg 1978).  Slight to  moderate enrichment  results  in  slight increases
in numbers  of  species,  abundances,  and biomass of benthic  communities (see
Figure  3  in main  text),  while  species  composition remains  unchanged.   As
enrichment  increases,  numbers   of   species  decline  because  less  tolerant
species are eliminated.  The total  abundance of organisms increases as a few
species adapted  to  disturbed environments or organically enriched sediments
become  very abundant.   When enrichment  levels are  optimal  for those  few
species,  they  become extremely abundant and  overwhelmingly dominate  the
benthic  community  (corresponding  to  the "peak of opportunists" shown  in
Figure  3).    Biomass generally  decreases,  however,  because  many of those
opportunistic  species  are  small.    Further  organic  enrichment  of  the
sediments  drastically  reduces   the  number  of  species  and  abundances  of
benthic organisms, as conditions become intolerable for most taxa.

     Because the  model  developed by  Pearson and  Rosenberg (1978)  has been
shown to  be valid in many benthic environments,  it is often  instructive to
examine the abundances of species that the authors identify as opportunistic
or pollution-tolerant.  Those data,  in conjunction with the applicant's data
on numbers  of  species,  total  abundances,  and biomass  at  stations  in  the
vicinity  of the  outfall,  are  often sufficient to determine the  relative
degree of impact within and beyond the ZID.
                                    C-l

-------
     Comparable  models that describe changes  In the  structure  and  function
of plankton  and  demersal  fish communities in organically enriched receiving
environments have  not  yet  been developed.  However, it may be instructive to
examine  the  scientific  literature that is available for  the biogeographic
region  in which  the  outfall  is  located.   That  literature  often  contains
information describing the responses of the local fauna and flora to organic
materials and other  pollutants,  and identifying opportunistic and pollution-
tolerant  species.    Such  information  is  extremely useful  for  interpreting
data collected in  the  vicinity of  the outfall.

     A  variety  of  analytical   tools  may  be  used  to  conduct  biological
comparisons  for Section  301(h)  applications.   Applicants may  analyze  the
data graphically or  statistically, or may use other mathematical tools such
as multivariate  analyses  (e.g., classification  and ordination  procedures).
Graphical analyses can be  especially useful for presenting data in an easily
understood  format.    In  Figure C-l,  data on numbers   of species  in  each
replicate sample at  stations  in  the vicinity of an outfall have been plotted
to show  the  range of  reference  values  in comparison  with values at within-
ZID,  ZID-boundary,  nearfield,  and farfield  stations.    These  data may  be
tested statistically to determine those  test  stations at  which mean values
differ  from mean  values  at  either  or both  reference  stations.   But  even
without  such tests,  the data in Figure C-l clearly indicate that a gradient
of  effects  occurs  near  the outfall.    Relative  to reference conditions,
numbers  of  species  are depressed at  the  within-ZID and  downcurrent  ZID-
boundary  stations, and may be depressed at the nearfield and upcurrent ZID-
boundary  stations.

     Graphical  analyses are  especially  useful  for presenting  data  on  the
physical  characteristics  of the  habitat.    For  example,  it  is  often  in-
structive  to plot water column  or substrate  characteristics  in relation to
distance  from  the outfall  (see  Figures  C-2  and C-3).  Gradients of effects
(as  in   Figure  C-3)  are  often   revealed  in  such simple  presentations.   An
especially   useful  method  for  presenting  data   on  sediment  grain  size
distributions  that  has   proven   useful  in  analyses of  301(h)   data  was
developed by Shepard (1954).  Sediments are classified by  the proportions of
                                    C-2

-------
                    50n
o
I
CO
UJ
H

O

O.
UJ
OC

OC
UJ
0-

(0
UJ
o
UJ
o.
(0

u.
o

OC
UJ
CD
                    40-
                    30-
                    20-
                    10-
                                                                                                     RANGEOF
                                                                                                    h REFERENCE
                                                                                                     CONDITIONS
                                    NET
                                    CURRENT^

                                    DIRECTION
                               REFERENCE  REFERENCE
                                  1          2
                                        ZID-
                                     BOUNDARYt
WITHIN

  ZIO
   ZID-
BOUNDARY2
                                                                                    NEARFIELO
                                                                                               FARFIELD
                                                       STATION
                 Figure C-1.  Numbers of species collected in replicate benthic grab samples at stations in the
                              vicinity of the outfall.

-------
        34-
        33-
  Q.

  IX
 z
 Zj
 <
 (0
        32-
        31-
        30
                   REFERENCE   REFERENCE      ZID-        WITHIN-       210

                       t           2      BOUNDARY 1      210      BOUNDARY 2
    I           I

NEARFICLO    FARFIELD
                                              STATION
Figure C-2.  Salinity at stations in the vicinity of the outfall.

-------
                  o
                  ffi
                  DC
                  <


                  o
                  Z
                  <
                  5

i
tn

                  O
1.0-
                           o.o
                                      REFERENCE  REFERENCE      ZIO-       WITHIN-       ZIO-

                                          I          2       BOUNDARY 1      ZID      BOUNDARY 2
                                                                   NEARFIELO
FARFIELD
                                                                  STATION
                  Figure C-3.  Total organic carbon content of the sediments at stations in the vicinity of the

                               outfall.

-------
their three major grain-size categories  (Figure C-4)
   Sand,  silt,  and  clay are often the most useful categories.  However,  the
gravel, sand, and mud  (silt plus clay) categories are useful  where sediments
are  relatively  coarse.    [See  Shepard  (1963)  for  information on  sediment
grain size scales.]

     Statistical  tests  are  among  the  most  effective  tools  for  comparing
biological communities among  stations.  A  variety  of statistical  tests  are
available, the  most widely  used of  which  is one way analysis of variance
(ANOVA).   ANOVA and other statistical tests  have been  used  extensively  for
biological comparisons in  the  301 (h)  program, but they  have  often been used
improperly.   For  this  reason,  procedures  for conducting statistical  com-
parisons  using  biological  data are discussed briefly below.   Applicants  are
encouraged to consult  references on biostatistics (e.g.,  Zar 1974; Sokal  and
Rohlf  1981)  for  more  specific  guidance on  the  application of  these  pro-
cedures.

      The  use  of  one  way ANOVA  for biological  comparisons is  preferred
because  ANOVA  is  an  efficient  and  robust test.   ANOVA compares  the  mean
values  of a  given  variable  among stations  (or groups of  stations)  for  the
purpose  of detecting significant differences at a predetermined probability
level.   ANOVA requires  a  minimum  of  three  replicate values  at each station
to estimate the mean value and associated variance.

     ANOVA is a parametric test  based  on three  assumptions:  the error of an
estimate  is a random normal  variate,  the data are normally distributed,  and
the  data  exhibit  homogeneous variances.  Corrections for  the first are not
easily  achieved,  and an erroneous assumption can greatly affect the results
of  the  test.    Fortunately,  error  estimates  in  survey  data are usually
independent.

     ANOVA is relatively robust  with  respect  to the assumption that the data
are  normally  distributed.  Substantial  departures  from  normality can occur
before  the value  of the F-statistic  is  affected greatly (Green 1979).   For
                                     C-6

-------
                                     SAND
NEARFIELO
REFERENCE 2
Z1D-BOUNDARY 1
REFERENCE 1
FARFIELD
WITHIN-ZID

2ID-BOUNDARY2
SILT
CLAY
          Figure C-4.  Sediment grain size characteristics at stations in the
                      vicinity of the outfall.
                                     C-7

-------
this reason,  tests for normality are not  usually conducted  before  data  are
analyzed using ANOVA.

     The  third assumption,  that  variances are homogeneous,  is  critical  to
execution of ANOVA.  Heterogeneous variances can greatly affect the value of
the  F-statistic,  especially  in  cases where the  statistical  design  is
unbalanced  (i.e.,  where numbers  of  replicate values  vary among the stations
or station  groups  being tested).

     Several  tests are available to determine whether  variances  are  homo-
geneous.  The  Fmax test (see Zar  1974; Sokal and Rohlf 1981)  and Cochran's C
test  (Winer 1971)  are both appropriate,  although  the  latter  is  preferred
because it  uses more of the  information in the data set.  Bartlett's test is
not recommended  because it is  overly sensitive to departures from normality
(Sokal and  Rohlf  1981).

     When  sample  variances  are  found  to  differ significantly  (P<0.01),  a
transformation  should   be  applied to the  data.   [A more  conservative pro-
bability level  (e.g.,  P<0.05)  should be used when the statistical  design is
unbalanced.  ANOVA is  sensitive  to unbalanced statistical designs.]   Sokal
and Rohlf  (1981)  describe  several transformations that may be used.  Because
ANOVA  on  transformed  data  is usually  a  more efficient test  for  detecting
departures  from the null  hypothesis than  is the Kruskal-Wallis  test (the
nonparametric  analog of ANOVA),  the Kruskal-Wallis  test should only be used
when  the  appropriate  transformation  fails to  correct for  heterogeneous
variances  (Sokal and Rohlf 1981).  The Kruskal-Wallis test requires a minimum
of five replicate  values per station  because it is a test of ranks.

     When   ANOVA   or   a Kruskal-Wallis  tests  are  performed,  significant
differences  (P<0.05) among individual stations or groups of stations may be
determined  using  the   appropriate  a posteriori  comparison.   Of  most  im-
portance  in 301(h) demonstrations  are  differences  among reference stations
and stations within the ZID, at the  ZID boundary, and beyond the ZID.  It is
primarily  these  comparisons upon  which   determination  of  the  presence  or
absence of  a balanced  indigenous  population  is based.
                                     C-8

-------
     Classification  analyses  (e.g., cluster  analyses)  have also  been  used
extensively  in the  301(h) program.    In the  normal classification  mode,
stations are  grouped by the attributes of the  assemblages  that occur there
(e.g.,  species  composition and abundance).   This type of  analysis  is  very
useful  for identifying  the stations  that  are the  most  similar  and least
similar to one another in fauna and/or  flora.  Because biological communities
respond  to  organic  materials  and other  pollutants,  stations  at  which
pollutant  impacts  are occurring typically cluster together  in interpretable
groups.  Inverse  classification analysis,  in  which  taxa are grouped  by the
stations  at  which  they  co-occur, is   also helpful  because  it  defines
assemblages  that  are  characteristic   of different  levels  and  types  of
pollutant impacts.

     Classification  analysis  involves  two analytical steps:  calculation of
a matrix of similarity values for all possible station pairs, and grouping of
stations based on  those between-station similarity  values.   Many similarity
indices  and clustering strategies are available to  perform these  two tasks
(see  Boesch  1977;  Green  1979;  Gauch  1982;   Pielou  1984;   Romesburg  1984).
However, only the  Bray-Curtis  similarity  index  and  either the group average
clustering strategy  (i.e., the  unweighted pair-group method  using arithmetic
averages) or the flexible  sorting strategy have been used commonly in 301(h)
demonstrations.  Their continued  use is recommended.  The  Bray-Curtis index
is  easily understood, and  has  been  used  widely  in ecological  studies.
Moreover,  two comparisons  of  similarity  indices  (i.e.,  Bloom  1981;  Hruby
1987)  have shown  it  to  be  superior  to many  of  the other commonly  used
resemblance measures.   Both the  group average clustering  strategy  and the
flexible  sorting  strategy  are  recommended  because they produce  little
distortion of  the original similarity matrix.   [See  Tetra Tech (1985) for
additional rationale on the use of  these three indices.]
                                    C-9

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                                 REFERENCES


Bloom,  S.A.    1981.   Similarity  indices  in  community studies:  potential
pitfalls.  Mar. Ecol. Prog. Ser. 5:125-128.

Boesch, D.F.   1977.  Application  of  numerical  classification  in  ecological
investigations  of water  pollution.   EPA-600/3-77-033.  U.S.  Environmental
Protection Agency,  Corvallis, OR.  115 pp.

Gauch,  H.G.   1982.  Multivariate  analysis  in  community ecology.   Cambridge
Studies in Ecology:  1.   Cambridge University Press, Cambridge, UK.  298 pp.

Green,  R.H.  1979.  Sampling design and statistical methods for environmental
biologists.  John  Wiley & Sons,  Inc., Mew York, NY.  257 pp.

Hruby,  T.   1987.    Using  similarity  measures  in benthic impact assessments.
Environmental Monitoring  and Assessment 8:163-180.

Pearson, T.H., and R. Rosenberg.   1978.  Macrobenthic succession in relation
to organic  enrichment and  pollution  of  the marine environment.   Oceanogr.
Mar. Biol. Annu.  Rev. 16:229-311.

Pielou,  E.G.   1984.   The  interpretation  of  ecological data - a  primer on
classification and ordination.   John  Wiley  & Sons, New  York, NY.  263 pp.

Romesburg, H.C.   1984.  Cluster  analysis for researchers.  Lifetime Learning
Publications, Belmont, CA.  334  pp.

Sokal,  R.R., and  F.J. Rohlf.  1981.   Biometry.  2nd ed.  W.H. Freeman & Co.,
San Francisco, CA.   859 pp.

Tetra Tech.   1985.  Summary of U.S.  EPA-approved methods,  standard methods,
and other  guidance for 301(h) monitoring  variables.   Final  report prepared
for Marine  Operations Division, Office  of Marine and  Estuarine Protection,
U.S.  Environmental Protection Agency.   EPA Contract  No.  68-01-6938.   Tetra
Tech, Inc., Bellevue, WA.  16pp.

Winer,  B.J.   1971.  Statistical  principles in experimental design.  2nd ed.
McGraw-Hill Book  Co., New York,  NY.   907 pp.

Zar,  J.H.   1974.    Biostatistical  analysis.  Prentice-Hall,  Inc.,  Englewood
Cliffs, NJ.  620  pp.
                                    C-10

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             APPENDIX 0
NAVIGATIONAL REQUIREMENTS AND METHODS

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                                 CONTENTS
                                                                        Page
LIST OF FIGURES                                                         iii
LIST OF TABLES                                                           iv
MONITORING STATION LOCATIONS                                            D-l
ACCURACY LIMITATIONS                                                    D-l
POSITIONING ERROR                                                       D-4
SUMMARY OF RECOMMENDED PROCEDURES AND EQUIPMENT                         D-7
CANDIDATE SYSTEM SELECTION                                              D-7
SHALLOW-WATER POSITIONING METHODS                                      0-11
USE OF LORAN-C                                                         D-13
SYSTEM SELECTION PROCEDURE                                             D-14
REFERENCES                                                             D-18
                                     ii

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                                  FIGURES
Number                                                                  Page
  0-1   Examples of some key 301(h) monitoring station locations for
        a medium-large marine municipal discharge                       D-2
  D-2   Locations of ZID-boundary stations for selected ZID sizes       D-6
  D-3   Examples of differential Loran-C error ellipse orientation
        at a ZID-boundary sampling station                             D-15
  D-4   Navigation system preliminary screening criteria               D-17
                                    m

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                                   TABLES
Number                                                                  Page
  D-l   Example ZID-boundary station locations                          D-5
  0-2   Summary of recommended systems                                  D-9
  D-3   Theoretical error ellipses of differential Loran-C for
        various U.S. locations                                         D-16
                                     IV

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                                 APPENDIX  0
                   NAVIGATIONAL REQUIREMENTS AND METHODS
     Information  presented  below addresses  navigational  requirements  and
methods  for Section  301(h)  dischargers.   It  is  summarizes more  detailed
discussions in Tetra Tech  (1987,  1988).

MONITORING STATION LOCATIONS

          Compliance  with  conditions  of  a   secondary  treatment  variance
requires  monitoring  at  a  site-specific array  of  sampling locations.   The
types  of  stations  usually  specified  in  301(h)   monitoring  programs  are
depicted  in Figure  D-l.   Positioning  accuracy  is most  critical  for  the
within-ZID  and  ZID-boundary  stations  (Stations ZQ,  1\,  T-i  in  Figure D-l).
Applicants  must  be  able to  sample  at  a specific  boundary  location  on  any
given  occasion,  and  to return  to nearly  the same location on  subsequent
trips.  At gradient  (Gj, 63,  63, 64) and control or reference (Cj) stations,
initial accurate  location  is not as critical.  However,  it  is  important to
relocate  these  stations  accurately during  subsequent  surveys  to  enable
quantification of  temporal changes  in  the  variables  sampled (e.g.,  benthic
community characteristics).   This requirement  for  high  repeatable  accuracy
also applies to stations in  or near special habitats (Hj,  H£).   The ability
to conduct sampling at the appropriate depth contour is also very important.
Sampling  programs  for 301(h)  typically include requirements that  a  bottom
sampling station can be  relocated to within 10 m (32.8 ft).

ACCURACY LIMITATIONS

     Both  the  procedures  and  equipment  used  to  establish a  navigational
position  contribute  errors  that  affect  the   overall  accuracy  of   a  fix.
Absolute or predictable  accuracy  is  a  measure  of  nearness to which a system
can define a position by latitude and longitude (Bowditch 1984).  Repeatable
                                    D-l

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o
ro
                                                COASTAL
                                               TREATMENT:
              . ..10m	"
                                                                                               SHELLFISH
                                                                                               HABITATS
            KEY:

               GRADIENT
            H  HABITAT
               REFERENCE
               NEARSHORE
            T  TRAWL
            Z  ZONE OF INITIAL DILUTION
                                                                             	30m	\!L*:**!*
ZIO BOUNDARY-
                                                                    ,-zi
                                                                           z,
                             • X   -60m	Jt-l
                              GI
                                PREDOMINANT
                                	^
                                CURRENT
                                      .gom ••
                Figure D-1.  Examples of some key 301 (h) monitoring station locations for a medium-large
                             marine municipal discharge.

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or relative  accuracy  is a measure of  a  system's  ability to  return the user
to a given position with  coordinates  that were previously  measured with the
same system.  The difference between these two  accuracies can be substantial.
For example, depending on one's location in the coverage area,  Loran-C has a
repeatable accuracy in offshore areas  of 15-90  m (49-295 ft), but an absolute
accuracy  of  185-463  m (607-1,519 ft)  (Dungan 1979).   In  many  instances,
repeatable   accuracy   is   more  important  than  absolute   accuracy  (e.g.,
retrieval of crab pots,  return  to desirable  fishing grounds,  avoidance of
underwater obstructions, and reoccupation of reference stations).

     For  coastal  outfall  monitoring,   both  repeatable  and  absolute accuracy
can be  important, depending on  the  type of sampling site.   For  within-ZID
and ZID-boundary  stations, both  accuracies are  important  because sampling
stations must be  located  within  or very near the  boundary  and be repeatedly
occupied  during the  program.   For gradient, special  habitat,  and reference
stations,  repeatable  accuracy  is more  important than absolute  geographic
location.  Once  such  a station  is established within  a special habitat, it
is often necessary to return to the same  site to identify temporal  variations
in the  previously sampled  biological  community.   Thus, it  is important to
select  navigational   procedures  and   equipment with  both  the  absolute and
repeatable accuracies needed to meet the monitoring program objectives.

     Because  repeatable accuracy  of   navigational  equipment is  usually at
least  1  order  of  magnitude  better  than  absolute accuracy,  the  latter
frequently  limits the  overall  positioning accuracy of  a  sampling  vessel
during  coastal  monitoring  programs.    Therefore,  the  following  discussion
focuses on  absolute  accuracies  that  can be achieved by various  procedures
and associated equipment.

     Practical  considerations  also   limit  the  accuracy  of  an  offshore
positional fix.   Resolution of a position to better than 1-2 m (3.3-6.6 ft)
becomes meaningless when  measuring the  location  of a  moving  vessel  (e.g.,
during  trawling)  or  a  vessel  that is on  station  but  pitching and rolling.
                                    D-3

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Antenna  movement  alone  usually precludes  higher  resolution  in  position
coordinates.    Exceptions  to  this  rule can  occur  when  conditions   are
unusually calm.

POSITIONING ERROR

     Many  factors  contribute  to the total  error  in position of the water
column or  benthic  sampling point.   These factors  include  movement  or drift
of the "on-station" vessel, offsets  between the deployment point of  sampling
equipment  and  the navigational  system  antenna,  and  offsets  between  the
deployment  point  and the  subsurface location of the  sampling  or profiling
equipment,  and  error  in the ship's  initial location.  Most of these factors
are  site-  or operationally  specific,  and  can be  estimated with  varying
degrees  of  confidence.   Because the accuracy to which  the  actual  sampling
point  is known  is highly  dependent on  all  these  factors,  they should  be
carefully considered  in both the design and conduct of monitoring programs.

     A  ZID-boundary  error  proportional   to  some   percentage  of  the  ZID
dimension   has  been   selected  as   the   controlling  parameter  for  301(h)
navigational  requirements.  Because  ZID size  is proportional  to water depth,
the  allowable error  in position is  thus also proportional  to depth.   For
example,  ZID-boundary  stations  can be   located  at  a distance  from  the
diffuser  axis equal  to  one-half  the ZID  width plus  20 percent  of the water
depth  at mean tide  level.   The  allowable maximum error in  the location of
these stations can then be ±20 percent of the water depth.  As a result, the
closest  to  the diffuser that  sampling  would occur  is  at  the ZID boundary,
and  the  farthest  from  the  diffuser  that  sampling  would occur is 40 percent
of the water  depth beyond this boundary.   Nominally, however, sampling would
be performed  within  a distance from the ZID  boundary equal to 20 percent of
the water depth.   Example ZID-boundary station  locations using this  approach
for  a  variety of  ZID sizes are  listed in Table D-l.   The ZID-boundary and
sampling station  locations  for discharges at the 100-, 60-,  and 20-m (328-,
197-, and 66-ft) depths are shown in Figure  D-2.
                                     D-4

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             TABLE D-l.   EXAMPLE ZID-BOUNDARY  STATION  LOCATIONS

Average
Diffuser
Depth
(»)
100
90
80
70
60
50
40
30
20
15
10
5
3
Average
Diffuser
Diameter
(m)
4.0
3.6
3.4
3.2
3.0
2.5
2.2
2.0
1.8
1.5
1.5
1.0
0.5
ZID
Width
(m)
204.0
183.6
163.4
143.2
123.0
102.5
82.2
62.0
41.8
31.5
21.5
11.0
6.5
Recommended
Station
Location3
(•)
122.0
109.8
87.7
85.6
73.5
61.3
49.1
37.0
24.9
18.8
13.8
8.5
6.3
Recommended
Allowable
Error6
(m)
±20
±18
±16
±14
±12
±10
±8
±6
±4
±3
±3
±3
±3

a  Distance from  the zone  of initial  dilution  centerline to  the station,
based on 0.5  times  the  ZID width plus 20 percent of the average water depth
of the diffuser when over  15 m (49 ft).

b  Error  magnitude  is  equal to ±20  percent  of the  average  diffuser depth,
when over  15 m (49 ft).
                                    0-5

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          3D BOUNDARY
               STATION
              LOCATION
100 m DEPTH
4.0 m DIFFUSER"
                ERROR_J 40m
                  LIMIT^^ W
                         I
                       210.
                 BOUNDARY
                                   -204m-
 122m
                                               ^OUTFALL PIPE
                                              , DIFFUSER
 60m DEPTH
 3.0 m DIFFUSER"
                        24m-
•*•
                                      123m
    735m
     -*•
 20m DEPTH
 1.8 m DIFFUSER
      -I*
                                  1 m-
                                         249
*r
     Figure D-2.  Locations of ZID-boundary stations for selected ZID sizes.
                                    D-6

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     When discharge depths  are  less  than  approximately 15  ro (49 ft), the 20
percent  error allowance  results  in  an overly  restrictive  positional  error
[i.e.,  less  than ±3 m  (9.8 ft)].   Therefore,  a positioning error  of +3 m
(9.8 ft)  is  considered to be more appropriate  when  sampling station depths
are  less  than 15 m  (49 ft).   Although  the percent error  as a function of
water depth  increases  at  shallower depths,  this minimum error is considered
reasonable given  available  navigating techniques for small sampling vessels
in  other  than  extremely  calm  waters.    Stations  beyond the  ZID may be
similarly located using the 20 percent of depth rule beyond the 15-m (49-ft)
contour and  the ±3-m  (9.8 ft)  error  limitation  for shallower locations.  As
indicated  earlier,  it  is  recognized that  the  ability to  reoccupy  a  given
site  can  be as  important  as  knowing  its exact  geographical  location.
However, relocation beyond the ZID probably will not  be a problem if the  same
navigational  equipment used  to locate  ZID-boundary stations  is  also  used
elsewhere.

SUMMARY OF RECOMMENDED  PROCEDURES AND EQUIPMENT

     Based on Tetra Tech's  evaluation  of optional positioning  methods, the
systems  recommended  for coastal  positioning  include theodolites,  sextants,
electronic  distance  measuring  instruments  (EDMIs),   total  stations,  and
microwave  and  range-azimuth  systems.    Although  satellite systems  offer
adequate  accuracy  (when  used  in a  differential  mode),  their use may be
limited  because  a  sufficient  number  of  satellites may not  always be
available.

CANDIDATE SYSTEM SELECTION

     The  details of  positioning  techniques and  associated equipment are
described  in  Tetra  Tech  (1987).   No single system  is best for all coastal
monitoring purposes.  Needs vary according to the  size and  complexity of the
planned  monitoring  program,  the nature  of  the  immediate  and surrounding
areas, and other navigational or surveying requirements of  a municipality.
                                    D-7

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     Positioning techniques fall into three principal measurement categories:

     •    Multiple horizontal angles

               Theodolite  intersection

               Sextant angle resection

     •    Multiple electronic ranges

               Distance-measuring instruments

               Range-range mode

               Hyperbolic  mode

               Satellite ranging

     •    Range and angle

               Theodolite  and EDMI

               Total station

               Range-azimuth navigation systems

Systems  within these  categories that  will  meet  or exceed the positional
accuracy' recommended  herein  are  summarized  in   Table  D-2.    Additional
information on the recommended  categories  is provided below.

Multiple Horizontal Angles

     In  the  multiple horizontal angles category,  theodolites  were  found to
have  the angular  accuracies required  for the  maximum  ranges  anticipated.
Their  costs  range from  $1,000  to $4,000  (30-sec  vs.  10-sec  accuracy),  and
                                     D-8

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                                                              TABLE 0-2.  SUMMARY OF RECOMMENDED SYSTEMS
Representative9
Category Equipment
Theodolite Table B-l
Table B-2
Accuracy
10-30
±1 m (3
sec
.3 ft)
Cost Advantages
$1.000-$4.000 Traditional method.
Inexpensive. High
accuracy . Success f u 1 1 y
applied. Restricted
areas.
Oi sadvantages
Line-of-sight. TMO
manned shore stations.
Simultaneous measure-
ments. Limits on
intersection angles.
Area coverage; station
movement .
     Sextant
Table B-3
    +10 sec
 ±2 m (6.6 ft)
  $1.000-12.000
     EON I
Table B-4
   1.5-3.0 cm
  $3.500-$15,000
     Total stations
     Microwave
     navigation
     systems
     Range-azimuth
     systems
     Satellite systems
Table B-5
Table B-6
Table B-10
Table B-9
     5-7  cm
      1-3 m
0.01° and 0.5 m
     1-10 m
  $8.000-130,000



 S40.000-J90.000




 $65,000-$100.000
$150.000-$300.000
 (initial units)
Rapid.  Easy to imple-
ment.  Most widely used.
Low cost.  No shore party.
High accuracy.
Extremely accurate.
Usable for other surveying
projects.  Cost.  Compact,
portable, rugged.
Single onshore station.
Other uses.  Minimum
logistics.

No visibility restric-
tions.  Multiple users.
Highly accurate.  Radio
I1ne-of-sight.

High accuracy.  Single
station.  Circular cover-
age.

High accuracy.  Minimum
logistics.  Use in re-
stricted/congested areas.
Future cost.  No shore
stations.
Simultaneous measure-
ment of two angles.
Target visibilities,
location,  maintenance.
Llne-of-sight.   Best
In calm conditions.
Limits on acceptable
angles.

Motion and direction-
ality of reflectors.
Visibility, unless
microwave.  Two shore
stations.   Ground wave
reflection.

Reflector movement and
directionality.  Prlsn
costs.

Cost.  Multiple onshore
stations.   Logistics.
Security.
Single user.  Cost.
Current coverage.   Ini-
tial development cost.
a Table references refer to Tetra Tech  (1987).

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they  are  readily  available  because they  are widely used  as  a  surveying
instrument.    At  least  two  theodolites,   two operators,  a  vessel  siting
target,  and   a  three-way  communications  link  to  coordinate  fixes   are
required.  Visibility can be  a  limiting factor.

     By  comparison,  sextant  angle  resection  can  be  performed  using  one
instrument  if the  vessel   is  stationary,   or  using  two instruments  simul-
taneously  if  the vessel  is moving.   Achievable angular  accuracy  of ±10  sec
is adequate,  and relatively inexpensive sextants ($1,000-52,000) are readily
available.  Again,  visible  range can be limiting.   Shooting  an  accurate  fix
from a non-stationary platform  in  any significant sea or swell could be more
difficult  than shooting  with theodolites from shore.  A distinct advantage
of  sextant angle  resection  is  location  of  the navigators  on  the  survey
vessel.   The  method  generally  requires highly visible  shore targets and  a
three-arm protractor  for plotting  positions.

Multiple Electronic Ranges

     Positioning using multiple ranges  can be accomplished with two staffed
EDMI stations.  Accuracies were found  to  be  more than  adequate  but ranges
were found  to be marginal  [if  needed beyond  3 km  (1.9 mi)]  unless multiple
prisms  are  used.    Because  such prisms   are directional,  procurement  of
multiple clusters  for more  than one direction could  result  in substantial
additional costs.  The initial  investment  (i.e., without multiple prisms) is
$3,500-$5,000  each for two shorter-range  units, or  $8,000-$ 15,000 each  for
two longer-range units.  Several microwave  navigation systems with more  than
adequate range and sufficient accuracy  are available in  the $40,000-$90,000
range.   Limitations  include geometry  of  shore stations;  position of  the
vessel in the  coverage area (i.e., crossing angle limitations);  and possible
interferences  due  to  line-of-sight  obstructions,   sea-surface  reflective
nulls, and  land-sea boundaries.  The hyperbolic mode provides multiple  user
capability, but at the cost of  an  additional shore station.

     Satellite ranging  holds promise because  required accuracies should be
achievable in  the  near future.   Transit satellite-based  systems do not offer
                                    D-10

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sufficient  accuracy,  except with  multiple  passes,  and multiple  passes  are
impractical  when  a  given  sampling  station  is  occupied  only  briefly.
Accuracies  needed  will  undoubtedly  be achievable   in  the  future  using
differential global positioning system (GPS) techniques ($10,000-$40,000 for
first units; as low as $1,000 for subsequent production models).  Commercial
geosynchronous satellite  networks,  such  as  GEOSTAR,  may become available at
a proposed  system interrogator cost  of  $450 plus a monthly  fee.  However,
this  system is in the  very early stages of  planning,  having only recently
received FCC  approval  of requested frequencies.  Finally,  the codeless GPS
systems  (SERIES  or  Aero  Services  Marine  GPS  System)  currently  under
development could be used, but at a current cost of over $250,000.

Ranoe and Angle

     Systems  in  the  range-azimuth category  show  great promise.   Required
angular  and  range  accuracies  are  available,  only  one  shore  station  is
needed,  and costs  depend on  system refinements.   At the low  end  of the
scale, an EDMI and  theodolite  could be paired with a communication link for
approximately  $10,000-$12,000.    Total  stations developed  specifically for
this requirement range  in cost  from $8,000  for a manual station to $15,000-
$30,000  for a  fully automatic station.  Optical  and infrared range limita-
tions apply to these  systems.   The three range-azimuth navigational systems
examined provide  sufficient  positional  accuracy with  a single  station at
costs ranging from $65,000 for manual tracking to $70,000-$100,000 for fully
automatic tracking.

SHALLOW-WATER POSITIONING METHODS

     When sampling  stations are  located in  relatively shallow water,  they
can be  identified  by relatively  inexpensive methods  (in  addition  to those
discussed earlier in  this report).   Provided the center of the ZID over the
outfall can be located (e.g., by diver-positioned surface float), an optical
range finder may be used  to establish the required distances to nearby water
quality or biological sampling stations.  An optical range finder is used by
simply  focusing  a  split-image  on  the  target  float,  enabling the  slant
                                    D-ll

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distances to the target  to  be read from the instrument scale.  When combined
with a careful  compass reading,  this distance reading allows positioning  of
the sampling vessel.

     A survey  of accuracies claimed for  commercially available instruments
suggests that the ±3 m (9.8 ft)  recommended minimum accuracy can be achieved
for ranges  up to  approximately  100 m (328 ft) from the surface target.  The
Lietz Model 1200,  for example,  provides  an  accuracy of. ±1 m  (3.3  ft)  at
100 m (328  ft).  Beyond  this distance, instrumental errors increase rapidly.
For the  instrument  cited,  a +9  m (29.5 ft) accuracy is quoted at 300 m (984
ft).  The  suggested U.S. list prices of optical range finders vary from $35
to $120  (Folk,  L.,  21  March 1985, personal communication).

     An  acceptable alternative  method for  collecting  bottom  samples  from
desired  locations in shallow water is to use divers.  Provided visibility is
adequate,  divers  may  measure   radial  distances  to  desired  locations  by
holding  a  tape  at  the outfall and  traversing the appropriate distance over
the bottom  in the proper direction.

     Visual ranges  have  sometimes been used to establish a station position.
This  method  requires  that a  minimum  of two  objects  are  in  alignment,
enabling the vessel to be placed on a common axis extending to the vessel's
position.   Simultaneous siting  on  a second  set of  at  least  two objects
places the  vessel  at  the intersection of the two common axes.  The accuracy
of each  visual  range  is highly  dependent on the quality of the visual range
(e.g., alignment),  the  distance  from the alignment objects  to the vessel,
and the  angle  between  each range.   Also, the  number  of  visual ranges used
affects  the magnitude of the positional  error.   Although this technique is
frequently  used for positioning single  sampling  stations in bays, harbors,
and other  areas in which two or more conveniently alignable targets can be
selected, the method  is  not considered acceptable for coastal monitoring at
ZID-boundary stations.  Also, it is not  likely that a sufficient number of
alignment  target-pairs  will  be present  for  all  desired  locations.    In
addition,  the   unpredictability  of   repeatable position error detracts from
the value of this method.
                                    D-12

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     Permanent  installation of  a marker  buoy  at the  outfall  terminus  or
midpoint  of the  diffuser allows  easy  return to  this  point on  subsequent
sampling trips.   Using  the previously  discussed  range-finder technique or a
line of  desired  length  enables positioning  at  desired distances  from the
marker  buoy.    However,  it is  not uncommon  to  lose  such  a  buoy  due  to
vandalism,  impact, or severe weather conditions.   Therefore, it is necessary
that the sampling party be prepared to relocate the outfall (e.g., by diver,
sonar,  or pinger  mounted  on the outfall  itself),  if location of stations is
dependent on knowledge of the outfall location.

     Because the  techniques  described  here are inexpensive to implement (as
are use  of  the sextant resection  or theodolite  intersection methods), they
are  attractive to  small  coastal  municipalities.    However,  use  of more
sophisticated  and  less  labor-dependent   techniques  may  be achievable  at
moderate costs by renting or leasing, rather than buying such equipment.

USE OF LORAN-C

     In their evaluation of positioning methods,  Tetra Tech (1987) concluded
that Loran-C did  not  provide the  absolute and repeatable  accuracies needed
for the 301(h)  program.  However, because  Loran-C is in such wide use and is
relatively  inexpensive,  use of Loran-C in  a  special  operating  mode was re-
examined  in Tetra  Tech   (1988).    The  special  operating  mode  is  called
differential Loran-C, which requires  an  additional Loran-C receiver onshore
at a known  geographic location.   At this  location,  the Loran-C signals are
received,  and   a  correction  is  generated and  transmitted  to  the  survey
vessel,  allowing  the correction  to be applied  to signals  received  by the
ship's  Loran-C unit.

     Differential  Loran-C  was  found to significantly improve the positional
accuracies  achievable compareu  to Loran-C  in  the  normal  mode.    During a
simulated monitoring  program near Newport  Beach,  California, normal Loran-C
positional errors of  40-50  m (131-164  ft)  were reduced  to  7-15 m (23-49 ft)
using  differential  Loran-C in  conjunction with  special   vessel  operating
                                    D-13

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procedures,  a  video  display,  and  data  averaging  techniques.     Higher
accuracies  are  expected  in other coastal  areas where  improved  lattice  line
crossing angles occur.  Acceptability may depend on relative orientations of
the diffuser and  the error ellipse axes (Figure D-3,  Table D-3).   For those
considering  use  of  differential Loran-C,  a  procedure for  determining  the
error in a ZID-boundary station  location is provided in Tetra Tech  (1988).

SYSTEM SELECTION  PROCEDURE

     A procedure  for selecting an appropriate navigation system is  described
in  detail   in   Tetra Tech  (1987).    The  procedure  involves definition  of
positioning  requirements,  establishment of screening criteria (e.g., range,
accuracy,  availability,   and  costs),  review  of  candidate  systems,  and
evaluation  of  purchase/lease  options.   As  indicated  in  Figure  D-4,  a
stepwise screening  technique  is recommended  to identify  an  optimal system
for  a  given monitoring  program.   At  each  step  in the  screening process,
systems that cannot  achieve the required criterion are removed from further
consideration.
                                    D-14

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                                              OUTFALL PIPE
  ZID
  BOUNDARY
  ELLIPSE ROUGHLY
PARALLEL TO DIFFUSER
 95% PROBABILITY
     ELLIPSE

X.Y)


I	ACROSS-ZID
    ERROR VARIATION
           ACROSS ZID
           ERROR VARIATION
  ELLIPSE ROUGHLY
 PERPENDICULAR TO
     DIFFUSER
    X.Y    Coordinates of ZID-
          Boundary Sampling
          Station.

    EH    95% Probability of
          Actual Sampling
          Station Position being
          in this Area.
       Figure D-3.  Examples of differential Loran-C error ellipse orientation
                    at a ZID-boundary sampling station.
                                    D-15

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       TABLE D-3.   THEORETICAL ERROR ELLIPSES OF DIFFERENTIAL LORAN-C
                         FOR VARIOUS U.S.  LOCATIONS

Location
Anchorage, AK
Puget Sound, WA
San Francisco, CA
Los Angeles, CA
San Diego, CA
Mississippi Delta, LA
Panama City, FL
Chesapeake Bay, VA
Boston, MA
Approximate
Direction
of
Major Axis
NW/SE
NW/SE
NE/SW
NE/SW
N/S
NW/SE
N/S
W/E
N/S
Length
of
Major Axis3
70
180
60
90
90
50
30
40 ~
30
Length
of
Minor Axis3
20
40
30
30
20
20
20
20
20

a Lengths are given to  the  nearest  10 m based on 95 percent confidence level
error  ellipses.    Standard  deviation  of  time differences  is  25  nsecs
(achievable with differential  Loran-C).
                                     D-16

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                                 2 i
                       CANDIDATE I SYSrEV
Figure 0-4.  Navigation system preliminary screening criteria.
                             D-17

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                                 REFERENCES


Bowditch, N.  1984.  American practical navigator.  An epitome of navigation.
Defense Mapping Agency  Hydrographic/Topographic Center, Washington, DC.  pp.
1272, 1278.

Dungan, R.G.   1979.   How to get the most our of LORAM-C.  SG 54.  Extension
marine advisory Program,  Oregon  State  University, Corvallis, OR.  12 pp.

Folk, L.   21 March  1985.  Personal Communication (phone by  Dr.  William P.
Muellenhoff, TetraTech).   Kuker-Rankin,  Inc., Settle, WA.

Tetra Tech.   1987.   Evaluation  of survey positioning methods for nearshore
and  estuarine  waters.  EPA-430/9-86-003.   Final  report  prepared for Marine
Operations  Division,   Office  of  Marine   and  Estuarine  Protection,  U.S.
Environmental Protection  Agency.  Tetra Tech,  Inc.,  Bellevue,  WA.  54 pp. +
appendices.

Tetra Tech.   1988.   Evaluation of differential  Loran-C for positioning in
nearshore  marine  and  estuarine  waters.   Draft report  prepared  for Marine
operations  Division,   Office  of  Marine   and  Estuarine  Protection,  U.S.
Environmental Protection  Agency.  EPA Contract No.  68-C8-0001.   Tetra Tech,
Inc., Bellevue, WA.
                                    D-18

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             APPENDIX E
URBAN AREA PRETREATMENT REQUIREMENTS

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                                  CONTENTS
                                                                        Page
LIST OF FIGURES                                                         iii
LIST OF TABLES                                                           iv
INTRODUCTION                                                            E-l
APPLICABLE TREATMENT PROGRAM APPROACH                                   E-3
     U.S. EPA GUIDANCE                                                  E-3
     LOCAL LIMITS                                                       E-5
SECONDARY REMOVAL EQUIVALENCY APPROACH                                  E-7
     SECONDARY TREATMENT PILOT PLANT DESIGN CRITERIA                   E-10
     SECONDARY TREATMENT PILOT PLANT STARTUP                           E-14
     SECONDARY TREATMENT PILOT PLANT OPERATING CRITERIA                E-16
TOXIC POLLUTANT MONITORING PROGRAM, TESTING PROCEDURES, AND
     QUALITY ASSURANCE/QUALITY CONTROL                                 E-24
     SAMPLING FREQUENCY                                                E-25
     SAMPLE COLLECTION AND ANALYSIS                                    E-26
     QA/QC                                                             E-43
UPGRADING TO A FULL-SCALE SECONDARY TREATMENT FACILITY                 E-50
DEMONSTRATING COMPLIANCE USING PILOT PLANT DATA                        E-55
REFERENCES                                                             E-56
ATTACHMENT 1:  U.S. EPA OFFICE OF WATER ENFORCEMENT AND PERMITS
     PROCEDURES FOR DEVELOPING TECHNICALLY BASED LOCAL LIMITS          E-59
ATTACHMENT 2:  U.S. EPA GUIDANCE MANUAL ON THE DEVELOPMENT AND
     IMPLEMENTATION OF LOCAL DISCHARGE LIMITATIONS UNDER THE
     PRETREATMENT PROGRAM                                              E-68
                                    E-ii

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                                  FIGURES
Number                                                                  Pace
  E-l   Components of a conventional activated sludge system           E-12
                                    E-iii

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                                   TABLES
Number                                 .                                 Page
  E-l   Effluent water quality values that shall not be exceeded
        under secondary treatment                                       E-9
  E-2   Secondary treatment pilot plant design criteria                E-ll
  E-3   Conventional activated sludge design parameters                E-13
  E-4   Pliot plant monitoring schedule                                E-17
  E-5   List of test procedures approved by U.S. EPA for inorganic
        compounds in effluent                                          E-28
  E-6   List of test procedures approved by U.S. EPA for non-
        pesticide organic compounds in effluent                        E-35
  E-7   List of test procedures approved by U.S. EPA for pesticides
        in effluent                                                    E-38
  E-8   Recommended sample sizes, containers, preservation, and
        holding times for effluent samples                             E-41
  E-9   Reported values for activated sludge biological process
        tolerance limits of organic priority pollutants                E-51
  E-10  Reported values for activated sludge biological process
        tolerance limits of inorganic priority pollutants              E-53
                                    E-iv

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                                INTRODUCTION
     Section 303(c) of  the Water Quality Act of 1987 amended Section 301(h)
of the  1977  Clean  Water Act by adding the "urban area pretreatment require-
ment."   This requirement  applies  only to POTWs serving a  population of at
least  50,000 and  only  to  toxic pollutants  introduced  by  industrial  dis-
chargers.   For  each toxic  pollutant  introduced  by  an industrial discharger
in affected  POTWs,  the  applicant must demonstrate  that  it  meets one of the
following two conditions:

     •    Has an "applicable pretreatment requirement in effect"

     •    Achieves  "secondary  removal equivalency."

This  new  statutory  requirement  complements  the   toxics   control  program
requirements in  the existing  Section 301(h)  regulations  (40 CFR 125.66) and
other pretreatment  requirements  in 40 CFR 403.

     The intent  of  this appendix is  to help POTWs interpret and comply with
the  new requirement.   For site-specific reasons,   concepts  and procedures
recommended  herein may not  necessarily  apply to  all  301(h)  applicants.
Issues that are not addressed by this appendix should be directed to U.S. EPA
Regional offices.   Applicants should also check with appropriate state and
local agencies for  any  explicit  requirements  (e.g.,  water quality standards)
that  apply  to  them.    The procedures  to demonstrate compliance  with this
urban area requirement  must be formulated and implemented  by each POTW with
concurrence from the  appropriate U.S.  EPA Regional  office.   Compliance with
the urban area  pretreatment requirement  is  required before a 301(h) permit
may be  issued  by U.S.  EPA, although tentative approval may be   granted on
demonstration of the applicant's good faith  effort.
                                    E-l

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     When  a review  of the 301(h)  application  indicates  that noncompliance
with pretreatment  requirements is substantial  and that  the applicant is not
taking  effective  steps  to assure  compliance,  then U.S.  EPA may  deny the
permit.    Factors  relevant to  such a decision  include the number  of  non-
complying  industrial  sources,  the  nature of their  toxic  pollutant contri-
bution  to  the  POTW,  and  potential  or  actual  POTW interference  of  pass-
through.
                                     E-2

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                   APPLICABLE TREATMENT PROGRAM APPROACH
     Applicable pretreatment  requirements for each  toxic  pollutant may take
one of two forms:

     •    Categorical standards

     •    Local limits.

Categorical standards  are  nationally uniform, technology-based pretreatment
limitations developed  for  specific  industrial categories under  Section 307
of  the  Clean  Water Act.    All  categorical  industries  must comply  with
categorical standards, even if  they  discharge to a  POTW without  a federally
approved  local  pretreatment  program.    By  contrast,  local  limits  are
developed by  the POTW to  prevent  interference with  the  treatment works or
pass-through of toxic pollutants, as required by 40 CFR 403.5(b).

     A given  industrial  discharger may be  subject  to categorical  standards
for some pollutants  and  local  limits for  other pollutants,  or to both types
of  limitations  for  the  same  pollutant.   In  the latter  case, the stricter
standard applies.    The  urban area  pretreatment requirement  for  all  toxic
pollutants entering  a POTW will probably require a combination of both forms
of pretreatment standards.

U.S. EPA GUIDANCE

     The U.S.  EPA Office  of  Water  Enforcement  and  Permits  (OWEP)  and the
U.S. EPA Office of  Water  Regulations  and Standards  (OWRS)  have issued the
following  guidance  manuals  to  assist POTWs  in implementing pretreatment
regulations and developing technically based local limits:
                                    E-3

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     •    Guidance  Manual  for  POTW Pretreatment Program  Development
          (U.S. EPA  1983a)

     •    Procedures  Manual for Reviewing  a POTH Pretreatment Program
          Submission  (U.S.  EPA 1983b)

     •    NPDES Compliance  Inspection Manual  (U.S. EPA 1984)

     •    Guidance Manual for  Implementing  Total  Toxic  Organics (TTO)
          Pretreatment Standards (U.S.  EPA  1985a)

     •    Guidance Manual for the Use of Production-Based Pretreatment
          Standards  and  the  Combined  Uastestream  Formula  (U.S.  EPA
          19855)

     •    Pretreatment  Compliance Monitoring  and Enforcement Guidance
          (U.S. EPA  1986a)

     •    Guidance Manual for Preventing Interference at  POTUs (U.S. EPA
          1987a)

     •    Guidance for Reporting and Evaluating POTH Noncompliance with
          Pretreatment Implementation Requirements (U.S. EPA  1987b)

     •    Guidance  Manual  on  the  Development  and  Implementation  of
          Local  Discharge  Limitations  Under  the Pretreatment Program
          (U.S. EPA  1987c)  (enclosed as Attachment 2 to  this  appendix).

The  implementation  and enforcement  guidelines in these  manuals require the
POTW to undertake the following:

     •    In the POTW industrial waste  survey (which must be  updated on
          a  regular  basis),  identify  and  locate all  industries that
          discharge  pollutants into  the POTW
                                     E-4

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     •    Demonstrate that the. sampling procedures and analysis program
          undertaken  were  adequate  to  characterize  industrial   and
          nonindustrial  pollutant  loading to  the POTW, and  pollutant
          concentrations in the POTW influent,  effluent, and sludge

     •    Compare measured pollutant concentrations to applicable sludge
          criteria or  guidelines,  water quality criteria or standards,
          and POTW process inhibition thresholds

     •    Demonstrate   that   the  existing  pretreatment   program  is
          adequate to  control  industrial user  discharges,   and that it
          contains specific numerical limits for industrial pollutants

     •    Demonstrate that local limits are technically based, adequate
          to  protect  the  POTW, and allow  compliance  with  its  NPDES
          permit

     •    Demonstrate that steps have been taken to identify the causes
          of past POTW operating problems (e.g., industrial discharges,
          equipment  failures,  plant  upsets,  NPDES  permit violations,
          sludge contamination) and correct them

     •    Demonstrate  that  POTW inspection  and  compliance monitoring
          procedures exist and are being implemented

     •    Demonstrate  that  the  needed  resources (e.g., funds,  staff,
          equipment) are available to carry out program requirements.

LOCAL LIMITS

     The  technical   approach  used  by  a POTW  to develop  local   limits  is
primarily a  local  decision,  provided that the  local  limits are enforceable
and scientifically  based.   Most POTWs  use the  headworks  loading  method in
the  U.S.  EPA  (1987c)  local   limits  guidance manual.    OWEP-recommended
procedures  for developing  local  limits  appear as  Attachment  1  to this
                                     E-5

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appendix.  Best  professional  judgment can  be used  to establish  pretreatment
requirements when  data or criteria are insufficient to perform  a  pollutant
loading  analysis for  a specific pollutant  of concern.   The applicant  may
implement  the  local limits via  uniform maximum  allowable concentrations or
discharger-specific maximum allowable mass emissions.

     Local limits should  be reviewed  and revised periodically in response to
changes  in federal  or state regulations,  environmental  protection  criteria,
plant design  and operational  criteria, or the nature of  industrial  contri-
butions  to POTW influent.   For  example,  the  following  specific  changes
could affect criteria  used to derive  local limits:

     •    Changes  in  NPDES permit  limits  to include additional  or  more
          restrictive  toxic pollutant limits

     •    Changes  in  water quality  limits  including toxicity require-
          ments

     •    Changes in sludge disposal  standards or POTW disposal  methods

     •    Availability of additional site-specific  data pertaining  to
          pollutant removal efficiencies and/or process inhibition.

     OWEP  is  presently  developing  guidance  to   determine the  technical
adequacy  of  ""ocal  limits and to  ensure  their enforcement.  This guidance
will also clarify  the use of  best professional judgment  for  establishing
local  discharge limits   or  technology-based limits  when  the  data  are
insufficient.
                                     E-6

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                   SECONDARY REMOVAL  EQUIVALENCY APPROACH
     One approach  that 301 (h) applicants may  use to  satisfy  the new urban

area  pretreatment  requirement is  to demonstrate secondary  removal  equiva-

lency.  As noted in 40 CFR 125.65(d):


     An applicant  shall  demonstrate that it achieves secondary removal
     equivalency through  the use of a  secondary  treatment  pilot plant
     at the applicant's facility which provides an empirical determina-
     tion of the amount of a toxic pollutant removed by the application
     of secondary  treatment  to  the  applicant's  discharge, where the
     applicant's influent  has not  been  pretreated.   Alternatively,  an
     applicant may make this determination using influent that has been
     pretreated, notwithstanding section 125.58(w).


In  effect,   the applicant's existing  treatment processes  and  industrial

pretreatment program  must remove at  least  as much  of  a  toxic pollutant as

would be  removed if  the  applicant  applied  secondary  treatment  and  did not

have  an  industrial   pretreatment   requirement  for  that pollutant.    This

approach can be represented as follows:


     POTW existing  +  industrial  =  POTW existing  +  no industrial
       treatment       pretreatment      treatment        pretreatment
                                       upgraded to
                                   secondary treatment


U.S.  EPA  recognizes,   however,  that it  would  be simpler for  applicants to

perform this demonstration by using a secondary treatment pilot plant on the

actual pretreated influent.  This approach is shown  below:


     POTW existing  +  industrial  =  POTW existing  +  industrial
       treatment       pretreatment      treatment       pretreatment
                                       upgraded to
                                   secondary treatment
                                    E-7

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Although  U.S.  EPA  will  consider  them,  demonstrations  to  account for  the
effects  of   industrial   pretreatment  will  probably  be  difficult.     The
secondary  treatment pilot plant approach is conservative (i.e.,  protective)
where it uses influent that has received  industrial pretreatment, because the
calculated  required removals  will  be greater  than  those resulting  from  a
demonstration using influent that has not been pretreated.

     Secondary  treatment  at  POTWs  typically  involves  biological  processes
that remove organic matter through  biochemical oxidation, usually variations
of the activated sludge process.  Other physical-chemical secondary treatment
processes  (e.g.,  coagulation,  filtration,  carbon adsorption)  may also  be
used, particularly  for  nonbiodegradable wastewaters.   The specific secondary
treatment  process  used by a  POTW  is dependent on numerous  factors  such as
wastewater quantity, waste biodegradability, and available space at the POTW
site.   Each  POTW must  determine the best  strategy  and  the  most applicable
treatment  process  for  complying  with  the  secondary  removal  equivalency
requirements.

     The  level  of  effluent quality  attainable through the  application of
secondary  treatment  is  defined in  40  CFR  133  (Table  E-l).    Treatment
processes  that  are  considered  equivalent to  secondary treatment  (e.g.,
trickling  filter,   waste  stabilization  pond)  are  discussed  in  40  CFR
133.105.  Minimum levels of effluent quality attainable from these equivalent
treatment processes differ from those shown in  Table E-l.

     Because  secondary  treatment levels were defined only for BOD, suspended
solids,  and  pH,  POTWs were  usually not  required to  institute technology
specifically  to control toxic  pollutants.   Under  the  1977 Clean Water Act,
toxic pollutants in the POTW effluents were controlled predominantly through
pretreatment  programs,  categorical  standards,  and local  POTW limits required
by the issuance of  NPDES  permits.
                                     E-8

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          TABLE  E-l.   EFFLUENT  WATER  QUALITY  VALUES  THAT SHALL NOT
                   BE EXCEEDED UNDER SECONDARY TREATMENT

Variable3
BOD5
CBOD5b
SS
PH
30-Day
Average
30 mg/L
25 rag/L
30 mg/L
6.0
7 -Day 30-Day Average
Average (Percent Removal)
45 mg/L
40 mg/L
45 mg/L
to 9.0
>85
>85
>85


a BODs =  5-day measure of biochemical oxygen  demand;  CBOD5  = 5-day measure
of carbonaceous biochemical oxygen demand; SS = suspended solids.

b At the  option of  the NPDES-permitting  authority,  CBODs may be substituted
for 8005.
                                    E-9

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SECONDARY TREATMENT PILOT  PLANT DESIGN CRITERIA

     A  secondary treatment  pilot  plant should  be  designed for  an  average
flow of approximately 150  GPD.   The flow rate should remain constant over a
24-h period.    The  pilot  plant  should .require minimum  operation  and main-
tenance time,   and  must be  able to  operate unattended  for  16-24 h.   The
organic loading will  vary  with  the diurnal  and seasonal fluctuations in the
BODs concentration  in the existing POTVI effluent.   Design  criteria for the
secondary treatment pilot  plant are shown in Table E-2.

     A conventional activated sludge  system  (Figure E-l) for a POTW includes
the following related components:

     •    Single or  multiple  reactor basins  (i.e.,   aeration  tanks)
          where microorganisms  consume  the  organic   wastes.    These
          basins are  designed  to  allow  for complete mixing of its
          contents, which  are defined as mixed liquor suspended solids
          (MLSS).   Each basin must provide typical hydraulic retention
          times of 2-24 h.

     •    Pressurized or  atmospheric  oxygen-containing  gases  that are
          dispersed into the reactor  basin.

     •    Settling  basin  (i.e., final  clarifier)  to separate the MLSS
          from  the treated wastewater.

     •    Equipment  to  collect  the solids  in the  settling basin, and
          to  recycle the  active  biological  solids  (i.e.,  activated
          sludge) to  the reactor basin.

     •    Equipment  to remove excess active biological  solids from the
          system.

Typical design   variables  for the  conventional  activated sludge process are
shown  in  Table   E-3.   Additional  information on  activated sludge  systems is
                                    E-10

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        TABLE E-2.  SECONDARY TREATMENT PILOT PLANT DESIGN CRITERIA
Reactor Basin (Aeration Tank)
     Volume
     Detention time
     Organic loading
     Air requirement
50 gal (189 L)
8 h
25-60 Ib BOD/1,000 ft3/day (0.4-1.0 kg/m3/day)
0.20-0.44 ftVnrin (0.33-0.75 n^/h)
Settling Basin (Final Clarifier)
     Volume
     Surface Area
     Overflow Area
     Solids Loading
     Weir Length
     Detention Time
20 gal (76 L)
0.375 ft2 (0.035 m2)
400 gal/ft2/day (16.3 mW/day)
14 Ib/ft2/day (68.4 kg/m2/day)
0.5 ft (0.152 m)
3 h
Influent Feed Pump
     Capacity
     Type
0-290 gal/day (0-12.7 L/sec)
Peristaltic
Return Activated Sludge Pump
     Capacity                 0-130 gal/day (0-5.7 L/sec)
                                    E-ll

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MR.UENT
                                                                                    EFFLUENT
                                                                                           WASTE
                                                                                         SLUDGE (WAS)
     Figure E-1.  Components of a conventional activated sludge system.

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   TABLE E-3.  CONVENTIONAL ACTIVATED SLUDGE DESIGN PARAMETERS
Food to microorganism ratio
Mean cell residence time
Aeration detention time
Oxygen requirements
Return activated sludge
  flow rate
0.15-0.4 Ib BOD5/lb MLSS/day
5-15 days
4-8 h
0.8-1.1 Ib (kg)  02/lb (kg)
6005 removed
30-100 percent influent flow
Mixed liquor suspended solids (MLSS)    1,500-4,000 mg/L
Organic loading at
  3,000 mg/L MLSS
Respiration (oxygen uptake) rate
  at 3,000 mg/L MLSS
Sludge volume index
Waste activated sludge
20-60 Ib BOD/1,000 ft3
(0.3-1.0 kg BOD/m3)
15-45 mg oxygen/L/h
90-150
0.4-0.6 Ib (kg)/lb (kg)
BOD removed
                               E-13

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provided by  the Water Pollution Control  Federation  [(WPCF)  1976,  1987]  and
WPCF/American Society  for  Civil  Engineers  (1977).

SECONDARY TREATMENT  PILOT  PLANT  STARTUP

     In the  activated sludge  process,  microorganisms  metabolize  nearly all
soluble organic matter  in  the influent.  The  microorganisms  (i.e.,  active
biological  solids)  must  be removed from  the settling basin to  produce an
acceptable  effluent,  and   the  proper  operation  of the  settling basin  is
critical.   The  following  process control  parameters should  be  monitored to
ensure proper operation  of the activated sludge system:

     •    MLSS

     •    Mixed  liquor volatile  suspended  solids (MLVSS)

     •    Dissolved  oxygen

     •    Sludge volume  index  (SVI)

     •    Sludge density index (SDI)

     •    Organic loading

     •    Return activated sludge  (RAS)  flow rate

     •    Waste  activated  sludge (WAS) flow  rate

     •    Mean  cell  residence  time  (MCRT)/solids retention time (SRT)

     •    Food/microorganism ratio  (F/M)

     •    Temperature
                                    E-14

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     •    Hydrogen ion concentration (pH)

     •    Respiration rate (RR).

In addition to  these  process  control  parameters,  microscopic examination of
the MLSS should be performed.

     An initial F/M ratio of 0.2 should be achieved.  Field operators should
adjust  the F/M  ratio  by  changing the  MLSS  concentration  in the  reactor
basin if the  required 30-day  average  effluent quality (i.e., 30  mg/L BOD,
30 mg/L  suspended  solids)   cannot be  achieved.     If  temperature  varies
substantially between summer and winter, the F/M ratio will probably need to
be lowered during winter to achieve the required effluent quality.

     The  pilot plant should  be  seeded  with  MLSS  from  a  local  domestic
wastewater treatment  facility.   Acclimation  of the pilot  plant will  require
about 4-6  wk.   If there is no local source  of MLSS,  the  pilot plant may be
started using  the POTW's effluent.   An  additional 4-6 wk may  be needed to
ensure that the MLSS meets the desired design concentration.

     The MLSS should be fed with domestic wastewater  for the first 2-3 days.
The  volumetric  proportion of the  effluent  should then  be adjusted  to 10
percent of the total feed for 4-5 days.  After  the  initial week of operation,
the  volumetric  proportion  of  the  regular  POTW effluent  in  the pilot plant
feed can  be  increased approximately  5 percent per day until  the system is
receiving 100 percent POTW effluent.

     Sampling for 8005 and suspended solids should be conducted daily during
and after the acclimation period.   Sampling  for toxic pollutants should not
be started until  2 wk  after  the pilot plant  is  receiving  100 percent POTW
effluent.
                                    E-15

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SECONDARY TREATMENT PILOT PLANT OPERATING CRITERIA

     The  process  control  parameters  identified  in  the preceding  section
should  be  monitored  to  provide  information  for  process  control  and  to
determine treatment efficiency.  A monitoring schedule is shown in Table E-4.
The  frequency of  sample collection  and analysis may  vary for  each  POTW,
however, depending on the size of  the POTW, available laboratory facilities,
available staff, and technical skills of personnel.  Additional  sampling and
analysis may be required for abnormal  conditions or during periods of process
upsets.   Implementation of  the monitoring program,  data interpretation,  and
pilot plant operation  and maintenance is estimated  to require about 5 labor
hours per day.  Each process control parameter is discussed below.

Mixed Liquor Suspended  Solids

     Samples  of  MLSS  should  be  collected from  the effluent  end of  the
reactor basin  twice daily  and analyzed for suspended solids.   This analysis
will  measure  the total  amount  of  solids in  the  aeration  system.    The
concentration  of the MLSS, which depends on the influent BODs concentration,
should be adjusted based on the daily average.

Mixed Liouor Volatile Suspended Solids  (MLVSS)

     Each MLSS sample should be analyzed for MLVSS.   This analysis indirectly
measures the  living biological percentage of the MLSS.  The concentration of
MLVSS is normally  70 to 80 percent of the concentration of the NLSS.

Dissolved Oxygen

     The  concentration  of dissolved oxygen  in the  reactor  basins should be
measured  twice daily  to ensure that  a concentration of 1-3  mg/L is main-
tained.   Samples  should  be collected  about 2  ft below the  surface of the
reactor basin, near the effluent weir.  .The plant operator should adjust the
air  supply  to  provide more air if  the dissolved oxygen concentration is less
than 1 mg/L and  less  air if  it is  greater than 3 mg/L.
                                    E-16

-------
                TABLE E-4.   PILOT PLANT MONITORING  SCHEDULE

Sampling Point
Primary Effluent
Parameters3
Temperature
pH
SS
BOD5
Overflow rate
CBOD5
Frequency
1 grab daily
1 grab daily
4 grabs weekly and
3 24-h composites weekly
3 24-h composites weekly
1 grab daily
1 24-h composite weekly
MLSS
WAS/RAS

Secondary Clarifier

Final Effluent
      Temperature
           pH
    Dissolved  oxygen
    Respiration  rate
  Sludge volume index
           SS
          VSS
Microscopic examination

           SS

  Sludge  blanket depth

      Temperature
           PH
   Settleable solids
           SS

          BODc
         CBOD5
1 grab daily
1 grab daily
2 grabs daily
2 grabs daily
2 grabs daily
1 grab daily
1 grab daily
1 grab daily

1 grab daily

2 grabs daily

1 grab daily
1 grab daily
1 grab daily
4 grabs weekly and
3 24-h composites weekly
3 24-h composites weekly
1 24-h composite weekly
a SS  = Suspended  solids;  8005
5-day  carbonaceous  biochemical
solids.
            -  5-day biochemical  oxygen  demand;  CBODc =
            oxygen  demand;  VSS  = volatile  suspended
                                    E-17

-------
Sludge Volume  Index  (SVH

     The rate  at which the MLSS settles in the settling basin depends  on  the
sludge  characteristics.    These characteristics are  described  by a  simple
settling test:  1,000 mL of the MLSS effluent is collected  and  allowed  to
settle  for 30 min  in a  Mai lory  settleometer.   At the  end  of  30 rain,  the
volume of  the  settled sludge  is measured.  The SVI is calculated as follows:

                     volume of settled sludge (mi] x l.QOO
                   '             MLSS (mg/L)

The  lower  the SVI,  the  more dense  the  sludge.   An  SVI  of  150 or less  is
usually considered good.

Sludoe Density Index  (SDI)

     The SDI  test  is also used to  indicate  the settling characteristics  of
the sludge, and it is arithmetically related to the SVI:
                              SDI
                              bD1   SVI

SDI  of  a  "good  settling  sludge"  is  about 1.0.  A  value of less  than  1.0
indicates  light  sludge that  settles slowly.   An  index greater  than  1.5
indicates dense sludge  that  settles rapidly.

Organic Loading

     From routine  laboratory BODs  analysis, the plant operator can determine
organic loading in  the  reactor  basin.

                  Organic loading = (Ib BOD/1,000  ft3/day)

     DHTUI c«i,,an*  onn  /«,«/i\ „ PQTW  Effluent Flow (HGD^  x 0.0624
     POTW Effluent  BOD  (mg/L) x    Reactor Basin Volume  (MS)

                                    E-18

-------
Return Activated Sludge  (RAS) Flow Rate

     To properly operate the  activated  sludge  process,  an  MLSS that settles
adequately  must be  achieved  and maintained.   The  MLSS are settled  in  the
settling  basin and  then returned  to the  reactor  basin  as  RAS.   The  RAS
allows the  microorganisms to  remain  in  the treatment system longer than the
flowing wastewater.   Changes in  the activated sludge  quality  and settling
characteristics will require different RAS flow rates.

     Two  basic approaches can  be used  to control  the  RAS flow rate.   One
approach  establishes a constant RAS  flow  rate,  independent  of the influent
flow.    This  approach  is  simple   (i.e.,  maximum  solids  loading   in  the
settling  basin occurs  at  the  start of  the  peak  flow  periods)   and  less
operator  attention  is  needed.  A disadvantage  of  this  approach is that the
F/M ratio  is  constantly  changing.   However,  because of short-term variation
in the  MLSS due to  hydraulic loading,  the range of  fluctuation  in the F/M
ratio  is   generally  small  enough to ensure that  no  significant  problems
arise.

     A second approach establishes the RAS flow rate as  a constant percentage
of  the  influent  flow.    This approach  reduces  variations   in  the  MLSS
concentration  and  the  F/M ratio, and the  MLSS  remain in  the settling basin
for shorter time periods (which  may  reduce the possibility of denitrification
in the basin).   The most significant disadvantage  of this approach is that
the settling  basin  is  subjected to  maximum solids  loading when  the basin
contains the maximum amount of sludge, which  produces excessive  solids in the
effluent.

     Two  methods  are  commonly  used  to  determine the  RAS flow rate.   The
settleability  method uses the  settled  sludge  volume from the SVI test to
calculate the RAS flow rate:
                                    E-19

-------
                           RAS Flow Rate (MGD) =
     w i    «* c ++1 A ci A   ' i ,\   TPQTW Effluent Flow (MGD)1
     Volume of Settled Sludge (ml) x •LJ-M	   i 000 ml —

The  second  and more  direct method  is  to monitor  the depth of the  sludge
blanket  in  the settling  basin.   The depth of the  sludge blanket  should  be
less  than  one-fourth  of the water depth of the  settling  basin  sidewall.
The operator must  check  the sludge blanket depth  twice daily,  adjusting the
RAS flow to control the blanket depth.  If the depth of the sludge blanket is
increasing,  increasing   the RAS  flow  is   only  a   short-term  solution.
Increases in sludge blanket  depth may result from too much  activated sludge
in the  treatment  system, a  poorly  settling  sludge, or both.   If the sludge
is settling  poorly,  increasing the RAS flow  may cause even more problems
by further  increasing  the  flow   through  the  settling basin.    Long-term
corrections noted  below must be made to improve the settling characteristics
of the sludge or remove the  excess  solids from the treatment system:

     •    If  the  sludge is  settling poorly  because of bulking,  the
          environmental   conditions  for  the  microorganisms  must  be
          improved

     •    If there is too much activated sludge in the  treatment system,
          the excess sludge  must  be wasted.

     The best time to measure RAS flow  is during  the period of maximum daily
flow, because  the clarifier is  operating under  the  highest solids loading
rate.   Adjustments in the RAS flow rate should be needed  only occasionally
if the activated sludge  process is  operating properly.

Waste Activated Sludge (WAS) Flow Rate

     The increase  of activated sludge is a cumulative  process that eventually
produces surplus  WAS.   This surplus  has  to  be permanently  removed from the
treatment  process  and collected  for ultimate disposal.  The  WAS  flow rate
should  be  determined and adjusted daily to  maintain  the desired  mean cell

                                    E-20

-------
residence time  (MCRT), based on the MLSS in the entire secondary system, and
RAS suspended solids concentration:

                                       [Aeration Tank Volume (MG) +
  WAS Flow Rate (MGD) = MLSS (mg/L) x	[dlsirlr ^^ ^^	
                                                               x
                                       [RAS Suspended Solids'(mg/L)]

Mean Cell Residence Time (MCRT)/Solids Retention Time (SRT)

     The MCRT,  which  is  also called  the  SRT,  is  a measure of  the  age of
sludge.  Under normal conditions, the MCRT is 5-15 days.  MCRT is defined as:

           Suspended solids in total secondary system (1b)   _
          Solids wasted (Ib/day) + effluent solids  (Ib/day)
TMLSS  (mo/DI x  [Aeration Tank Volume(MG) + Secondary Clarifier Volume(MG)1
               [WAS Suspended solids  (mg/L) x WAS Flow  (MGD)] +
          [Effluent Suspended solids  (mg/L) x Effluent  Flow  (MGD)]
     MCRT  is the  best  process control  technique  available  to  the plant
operator.  By using  the MCRT,  the operator can control the quantity  of food
available  to  the microorganisms   and  calculate  the  amount of  activated
sludge that should be wasted.

Food/Microorganism Ratio  (F/M)

     The F/M  ratio is  the  ratio  of BOD in the POTW effluent to the MLVSS.
An F/M ratio of 0.15 to 0.4 is  desirable.  F/M is defined as:

                          POTW Effluent BOD fmo/L)
                              MLVSS  (mg/L)

To control the F/M ratio, the operator must adjust  the MLSS by wasting more
or less sludge.
                                    E-21

-------
Temperature

     In  process  control, accurate  temperature measurements  are  required  to
predict  and  evaluate   process  performance,  thereby  enhancing  microbial
growth.   Typically,  the rate of microbial  growth  doubles  for every  10°  C
increase  in  temperature  within  the  specific  temperature  range  of  the
microbe.

Hvdrooen Ion Concentration  (oH)

     The activity and health  of microorganisms  is affected by  pH.   Sudden
changes  or abnormal  pH  values may indicate an adverse industrial discharge.
A pH drop  will  also  result  when nitrification  is  occurring in a biological
process; alkalinity is  destroyed and carbon  dioxide  Is  produced during  the
nitrification process.

Respiration Rate  (RR)

     The efficiency  of  the  activated  sludge process depends primarily  on
the  activity  of  bacteria that  use organic  compounds in sewage for energy
and  reproduction.   When  in contact with  an adequate  food  supply,  viable
bacteria will have a respiration rate (i.e., oxygen uptake rate) of 5-15 mg
oxygen/h/g  MLSS.    Respiration  rate  data  provide   immediate  information
concerning viability,  nitrification, organic loading,  nutrient  levels,  and
toxicity in the activated sludge.
             f
     The  respiration  rate,  or  oxygen  uptake  rate,  is monitored  with  a
dissolved  oxygen  meter  over  a  time interval  (t)  (e.g.,  6-10  min).   The
respiration rate  is  a  measure of  the  decrease  in  dissolved oxygen concen-
tration:

     RR  (mg oxygen/h/g MLSS) = TOO  change  over t (ma/Pi x  [60.0001
                                     [MLSS  (rngyt)] x [t (min)]
                                    E-22

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Microscopic Examination

     Microscopic  examination  of the  MLSS  can  be  used  to  evaluate  the
effectiveness of  the activated  sludge process.   The most  important  micro-
organisms are the protozoa, heterotrophic bacteria, and autotrophic bacteria
responsible for  purifying the  wastewater.   Both  protozoa  (e.g.,  ciliates)
and rotifers  are  indicators  of treatment performance, and  large numbers of
these organisms in the  MLSS  indicate good quality sludge.   Large numbers of
filamentous organisms  and certain ciliates Indicate  poor sludge quality, a
condition commonly  associated with  a  sludge  that settles poorly  (i.e.  the
sludge floe is usually  light and fluffy because it has a low density).  Many
other organisms  in  the sludge (e.g.,  nematodes,  waterborne  insect larvae)
may be found in the  sludge.  However, these organisms are not significant to
the activated sludge process.
                                    E-23

-------
          TOXIC POLLUTANT  MONITORING  PROGRAM, TESTING PROCEDURES,
               AND QUALITY ASSURANCE/QUALITY CONTROL (QA/QC)
     A  sampling  strategy  must  be developed  to  estimate the  difference
between toxic  pollutant concentrations  in  the  existing  discharge and those
in the secondary treatment  pilot  plant discharge.  Samples must be collected
using proper techniques and  analyzed  using appropriate analytical  methods.
Both  field  and  laboratory methods must be  performed under  defined QA/QC
procedures.

     Applicants  are  referred  to  the following  documents  for  guidance on
specific  topics  relevant to  the  design  and  execution  of  301(h)  monitoring
programs:

     •    Sampling/Monitoring Program

               NPDES  Compliance Sampling Manual  (U.S.  EPA 1979a)

               Design  of   301(h)   Monitoring Programs  for  Municipal
               Uostewater Discharges to  Marine Haters  (U.S. EPA 1982a)

               Handbook for Sampling and Sample Preservation  of Water
               and Uastewater (U.S. EPA  1982c)

     •    Chemical Analytical Methods

               Methods  for Chemical Analysis of Uater and Hastes (U.S.
               EPA 1979b,  revised 1983)

               Guidelines Establishing Test Procedures for  the Analysis
               of Pollutants  [40  CFR  Part 136 (1984)]
                                    E-24

-------
               Standard  Methods  for  the  Examination  of  Hater  and
               Hastewater (16th ed.) (American Public Health Association
               1985)

               Analytical  Methods  for  EPA  Priority  Pollutants  and
               301(h)  Pesticides  in  Estuarine  and Marine  Sediments
               (Tetra Tech 1986a)

               Analytical  Methods  for  EPA  Priority  Pollutants  and
               301(h) Pesticides  in Tissues from Estuarine  and Marine
               Organisms (Tetra Tech 1986b)

     •    Quality Assurance/Quality Control (QA/QC)

               Handbook  for Analytical  Quality  Control  in  Mater and
               Wastewater Laboratories (U.S. EPA  1979c)

               Quality  Assurance/Quality  Control  (QA/QC)  for  301(h)
               Monitoring Programs:   Guidance  on Field and Laboratory
               Methods (Tetra Tech  1987).

Information from these documents is summarized  below.

SAMPLING FREQUENCY

     The frequency of sampling  is  dependent  on  the characteristics  of  the
discharge  (e.g.,  influent and  effluent  toxic  pollutant  variability, flow,
size  and  location  of  the discharge).   For example,  large  applicants with
substantial  quantities  of  toxic  pollutants   should conduct  more frequent
sampling  than small  dischargers  with fewer  toxic  pollutants.    Also,   if
existing  toxic pollutant  data  are minimal,  and  estimates  of  periods   of
maximum pollutant  loadings and  peak concentrations are not known, then more
frequent monitoring is needed.
                                    E-25

-------
     The  concentrations of  toxic  pollutants in the  discharge  may vary  in
response  to  periodic peak  inflows.   If a  fixed periodic trend  is  observed
(e.g., a  sine  curve)  the sampling  plan could be designed to collect samples
during the peak period.

     If a fixed sampling interval  is  chosen that  is  equal  to or a multiple
of the period,  every  sample would  be taken at the sane inflow condition and
the  estimate  of  the  mean difference  in  toxic  pollutant  concentrations
between samples  would not take  into effect all  possible inflows.   The most
favorable sampling situation occurs when the fixed sampling interval  is  an
odd multiple of the half-period  (i.e., successive deviations above and below
the  mean  inflow  would mathematically  cancel  one  another,  and  the  mean
difference in  concentration between  samples would  take into effect the mean
inflow).   However, toxic pollutant effluent data from the applicant may not
be  sufficient  to  identify  the  odd  multiple of the  half-period.    In  this
case, a fixed  sampling  interval  would  not be recommended.

     Assuming  that the  toxic pollutant limits for  the POTW will  be based on
the pollutant  concentrations measured  in the secondary treatment effluents,
a flexible sampling scheme  for secondary treatment pilot plant effluents may
involve sample collection  for 1  day/wk (over 24 h) on different days of the
week over a 1-yr  period of pilot plant operation.   This flexible sampling
frequency would generate a  data  set that represents an acclimated biological
treatment system.   It would also address the day/night, weekday/weekend, and
seasonal  variations  in  domestic,  industrial/commercial, and wet-  and dry-
weather discharges.

SAMPLE COLLECTION  AND ANALYSIS

     Representative   samples must  be   collected  to  ensure  that   data  are
reliable.   Care must be taken  to select  appropriate sampling  devices and
procedures.  Depending  upon the toxic  pollutant to be analyzed,  three types
of samples may be  collected:
                                    E-26

-------
     •    Grab sample  -  a discrete sample volume is  collected.   (This
          type of sample will  not always provide an  accurate  measure
          of wastewater  characteristics,  particularly when  the  flow or
          pollutants are heterogeneous or vary with time.)

     •    Simple  composite  sample  -  equal  sample volumes are collected
          sequentially  overtime and  combined  in  a  single  reservoir.
          (This type of  sample  does  not  measure the mass of pollutants
          discharged,  because  pollutant  loading  is  a  flow-related
          value.)

     •    Flow-proportioned composite  sample  - incremental  samples are
          collected  over time  and  sample volumes are proportional  to
          flow.  Incremental samples are  combined in a  single reservoir.
          (This type  of sample provides  the  most accurate  measurement
          of wastewater quality and pollutant loading.)

     The  methods  to  be used  for  the   analysis  of  toxic pollutants  are
summarized in  Tables  E-5,  E-6,  and  E-7.   Grab samples for  volatile organic
compounds,  total   recoverable  phenolic  compounds,  and cyanide  should  be
collected manually at  least four times during the discharging period of the
POTW during  a  24-h period  (e.g.,  at least every 6 h  within  a  24-h period,
assuming continuous  discharge).   Samples for all other variables  should be
collected using an automatic  sampler.  The automatic sampler should collect
a selected  number of  sample  aliquots (minimum  of  100 ml  each)  during the
discharging  period  of the  POTW.    Recommended  sample sizes,  containers,
preservation techniques,  and  holding times are  shown  In Table  E-8.   Sample
analyses will  generally  be completed by the analytical laboratory within
4-6 wk; data analyses  will  generally require  an additional  week.   Interpre-
tation  of  all  data collected  at  the  pilot plant during 1 yr  will  require
about 2 wk.
                                    E-27

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        TABLE E-5.  LIST OF TEST PROCEDURES APPROVED  BY  U.S. EPA
                  FOR  INORGANIC COMPOUNDS  IN EFFLUENT

Note:  This table is an  exact reproduction  of Table  IB in 40 CFR 136.3,

Parameter, units, and method

1 Acidity, u CjCOj mg/L Electrometric
end potm or pnenoipmhaiem tnd point.
2. Alkalinity, a* CaCOi mg/L
Eloctrometnc & coiorirnetnc titration
to pH 4.5. manual, or.
Automated 	
3. Aluminum— Total ' mg/L: OigmMn '
followed by:
AA diract aspvation 	
AA furnace
inductively coupled ptainia of
Cotonmatric (Encnrome cyanma fl)
4. Ammonia (as N), mg/L: Manual di-
lation (at pH 9.5) » loiiowad by.
Nessienxaoon 	

.
Automatad aiecuode
5. Antimony— Total ». mg/L Digestion »
touowadby:
AA drect aspvation 	
AA fumaca or
inductual> coupiad plasma
6 Arsemc— Total '. mg/L Oigastion »
loiiowad by
AA gasaous hydnda 	
AA fumaca 	
inductively coupiad plasma, or
Cotonmetnc (SDDC) 	
7 Banum— Total J. mg/L Digestion > tot-
lowad br
AA direct aspiration
AA fumaca. or 	
inductivaty coupiad plasma
8. Baryibum— Total '. mg/L Oigastion *
followed by:
AA d»act aspraton 	
AA furnace 	
inductively coupled plasma, or 	
Colonmetnc (ahxxnon) 	
9 Biochemcal oxygen demand (BOO.).
mg/L
Omsofved Oxygen Depletion 	
10. Boron— Total. mg/L
or induciNtly Coupisd ptfttnta

12. Cadmium— Total >. mg/L Digestion »
followed by:
AA droct aspiration 	
AA lumaet
induchvety coupled plasma
vottametry I0 or
Colonmetnc (Ditnizone)
13 Caiouin— Total ]. mg/L Oigestwn 3
loiiowed by
AA direct aspiration 	
Reference (method No or pag«>
EPA 1979
305.1 	
310 1
310.2 	
202.1 	
202.2 	


3502 ..
350.2 	
350.2 	
3503
350.1 	
204.1 	
2042.

206.5
206.3 	
206.2 	

206.4 	
2061
206.2 	

210.1 	
210.2


4051 .
2123...

320.1 	
213.1 	
21 3.2 	



215.1 	
Standard
metnodt
istn Ea.
402(4 •) 	
4Q3

303C 	
304 	

3068..
41 7A 	
41 7B 	
41 7O 	
417 E OfF...
41 7G

303A 	
304


303E 	
304 	

307B 	
303C
304 	

303C 	
304

3098
507 ....
404A


303 A or 8,
304 	


31 OB
! 303A 	
ASTM
106742(E) 	
01067-62(6) 	
	 	 	



01428-79IA) 	
01426.79(0) ..
01426-79(0) 	




02972-64(8) 	

02972-64(AK..-


036S4-64(A) 	





01246-82IC)....
0355744 (A
or 8).

USGS'
1-1030-44 	
I-2C30-44 	
I-3051-A4 . .




I-3S20-44 	

1-4523-44 	




I-3062-44 	

I-3060-44 	
I- 3094^*4


I-309S-94 	



1 -1578-76 7 	
1-311 2-»4 	
l-1125-«4 	
1-3135-44 or
1-3136-44
i
03557-64(C) -

1
OS11-*4(B) 	
!
I-315J-44 ..
Otner
33014^
2007*
33 057 '
33 057 '
NOW 6.
200.7.«
2007*
200.7'
200.7 «
33.019'. p. 17'
200.7. •
P. S44.»
33 089 ». p. 37 '
200 7 «
i
                                  E-28

-------
TABLE E-5.  (Continued)
Parameter units, ana metfoo
nefefence imetnod No or page)
Standard
EPA 1979 metnoas *STM uSGS ' Otner
i6m '6d
inductively couoiea piasma. or
T.tnmetnc lEOTA) 2152 3nC..
'4 Carbonaceous oiocnemtcai orygen 507(5 e 6)
demana (CBOD .). mg/L " Dissolved •
Oxygen Oeoienon with iitnticawn in-
hibitor
is Chemical oxygen demand (COO).
mg/L
TitnmetPC or ! 410 i I 508A
Spectropnotometnc. manual or auto-
mated.
16. Chloode. mg/L.
Titnmetnc (silver nitrate)
or (Mercuric nitrate), or 	
Colonmetnc manual or
Automated (Femcyanide) 	
1 7 Chlorine— Total residual. mg/L.
Titnmetnc: 	 .
Amoerometnc dvect
Starch end pomt direct
Back mratton either end
point '«. or
OPO-PAS
Spectropnotometnc. OPO 	
Or Electrode
18 Chromium VI dissolved. mg/L: 045
micron filtration followed by:
AA cheJabon-extraction. or 	
Colonmetnc (DiphenytcarOanOe) 	
19 Chromium— Total ]. mg/L. Diges-
tion ' followed by:
AA direct aspiration
A A cneiauon extraction ....
AA furnace 	
inductively coupled plasma or
Colonmetnc (Qiphenylcaroagde) 	
20 Cobalt— Total '. mg/L: Digestion J
followed by:
AA direct aspiration 	
AA "umace or
i-?jctiveiy coupled plasma 	
21 Cc-or platinum cobalt urets or don*-
nam wavelength, hue. luminance
Ounty:
Colonmetnc (AOMI) or . .
(Platinum cobalt), or 	
22 Copper— Total1 mg/L Digestion-1 fol-
lowed by:
AA direct aspiration 	
AA furance 	 ' 	
inductively coupled plasma
Colonmetnc (Neocuproine) or
(Bictncnoninate)
23. Cyaraoe— Total. mg.L: Manual distil-
lation with MgCk followed by
Titnmetnc or
410.2. or 	
410.3 	 !
4104 '

325.3 	
3251. or 	
325.2 	
330 1
3303
330.2 	
3304
330.5 	

407A 	
407B 	
4070 	
408C
408A 	
4088 	
4080 	
408E 	

21B.4 	 i 303B 	

218 1
2183
218.2..

219.1 	
2192

110 1
110.2 	 	 	
110.3 	
220.1 	
220.2 	




303A
303B
304 	

3128 	
303 A or B...
30*

2040
204A 	
2048
303 A or 8...
304 	

3138

O5n-84
Note 15
307B.'«
33.089'
200.7'
P 37«
200.7 •
Note 17
33.089'. p 37 •
200.7."
Note 16.
p. 22.'
                                    E-29

-------
TABLE E-5.    (Continued)
Parameter units, and memoa

: Sundaro
EPA 1979 ; metnads
I • 16th Ed'
Seferenct
(mttnod Ho. or page)
: ASTM I USGS <

Other
24 Cyandie amendable to cnionnaMn
mg.'L Manual distillation with MgO..
followed by ntnmetnc or spectropnoto-
metnc
25 Fluonde— Total. mg/L. Manual distil-
lation' followed by
Electrode manual or
Automated.
Cotonmetnc (SPAONS) 	
Or Automated comptexone 	
26 Gold— Total9. mg/L Digestion' 
-------
TABLE E-5.  (Continued)
Parameter, unrta. and method
Refer
j Standard !
EPA 1979 ' metnoda !
: tern Ed. !
•nca (ntattiod No. or pagv)
i !
ASTM | USQS1 Othar

35. Mercury— Total ». mg/L
CoM vapor manual or .... ...
Automated
36. Molybdenum— Total ». mg/L Oigee-
ton* followed by:
AA diraet aapvation
AA furnace or 	 	

37. Mien* Total'. mg/L Oigaetton'
tallowed by:
AA direct aapratton 	
AA furnace

^.AbMtah^Vb* /U^MtMVMMAh
36. Nitrate •*• N). mg/L Cotortmetrtc
(Bruome ..fata), or Nr&ate-nrmte N
minua Nitna N (See parameter! 39
and 40).
39. Nttata-flrtrite (aa N). mg/L Cadmium
reduction. Manual or
Automated, or 	 ,„„....., 	

40. Nttite (aa N). mg/L Spectropholo-
«*%^Me*^>
ii*WiC*
Manutf or 	 	 	


HIQ/LJ QnvvnMftc (wttoctton)*
^2 Organic ruTinn Tntil (TOC), mg/L
ComDuftttoo or oBOBDon.
43. OrgMe ratroQ^n <•• N) mg/L Tot*
Kj*dlN N (P.¥aVn.JtO 31) fTWM «IV
morw N (Pwrwttr 4.).
44. OrtfnpnoapnaM (aa P). mg/L Aaoor.
DIC acid moffodt
Automated or... 	 	
Manual angle reagent ...._.„.„.
or Manual two reagent 	
45. Oamium— Total «. mg/L Oigaatton'
followed by:
AA diraet *T**ittrff*. or
AA furnace . „

(A«od»K fWoinC4uori}( or
Etoemde
47. Palladium— Total '. mg/L Dlgeetten •
followed by
AA furnace , , 	
48. Phenol mg/L
FoNOVMQ by!
CoiorvTwtlc (-1AAP) m.vu^. or
Autormtvd >t
49 ptmrjftorm (•tomtnttf) mg/L: QM-

SO. Pho«pfwfu»— Total, mg/U PvaUfaia
dlgMtton foNowad by
Manual or

or.

245.1 	
245.2.
246.1
246J. 	

249. 1._ 	 _..
249.2. . 	


352 1
393 S
353.2, 	
353 1
3941

413.1 	 „ 	
4151 .

368.1 	 	
30&2.
MS 3
252.1
352,2,, 	
MQ2
380.1
253.1
253,2
420.1 	 —
420 1
420.2. . _

'
36U.
365 3. or
365.3.
366.1 	
365.4 	

303F 	

303C
304 ...

303 A or B...
304 .... _ ...

3218

416C.._ 	
416F 	

419 	

W3A
SOS ....

424Q 	
424F 	

303C
304
4218 	
421 F .







424C4III)
424F .
424G 	


03223-80 	




01866-64 (C
orO).


0992-71 	
O3867-«5(B) 	
D3867-«5(A) 	

01254-67... 	


02579.65 (A or
8).

051S-62(A)...:....



0888-61 (C) 	



01783-60 (A
or 8).




051S-62(A)



I-3462-84 	

I -34 90-84


1^499-44 	





I-4S49-64


I-4540HM



l_4601-64 	




1-1575-76' 	
M 576-76 T 	









1 4600 'S4 	
•

33095 *



2007 4


2007 *

33063* 4190 >•
p. 26.'


Note 24.


33.044 >, p. 4."

33.116. '
33.111.*



33.026. •

P. S27.»
P. S26.'
Note 26,
Note 26.

Note 27.

33.111.'

33.116.'

                                   E-31

-------
TABLE E-5.  (Continued)

Pwrt0t6f , unrts, and fnatnoo
51. Platinum— Total ». mg/L DigaWon'
toflowad OIT
AA direct aapirabon or
AA fumaca
52. PotnaMm— total *. mg/L Oigaation
feftowadby:

RMM jJyiinitMtig- *doa*cata) or

62. Silvar— Total '*. mg/L Pgaation •
(oltowadby:
AA diract aapranon
AA lumaca 	 „..


63. Sodium— Total ». mg/L Ogaatton »
tonowadbr
AA diract Mpraoon 	
inducovaty coupiad piaama. or .
Rama photomatnc .. . .

_4_ At 4C'^> lAA»^i^^«*«k^b^ ^- 	 -• 	
cm •! 2a w. wn*Mmon9 DnOQ0
65. SuHatt (M SO«). mg/L
AutomsMd cotefimtuic. (bwwm
craoranrtatt).
Turbidwnatne 	
66. Suffida (ai S). mg/L
Tttnmatnc (iodma) or 	
Cotormatnc (mattiyiana Wua) 	
67. Sulfita (a» SC>). mg/L Tttnmatnc
dodmaiodata)
68 Surlactants. mg/L: Cotonmatnc
(m»my»«na bloat.
69 Tamoaratura. 'C.. Tharmomatnc 	

EPA 1079
2551
255.2 	
258.1 	



160.3 	
1601
160.2.... 	
160.5 	

1604
2651
2654. 	
267 1
267.2. 	 	
270.2.

270.3.. .
370.1 	


272.1
2724. 	


273 1



375.1 .
! 375.3
375.4 	
I 376.1 	
! 376.2 	
j 3771
: 425.1 	
i 170.1 	
Ra
Standard
fnainoos
letfiEd.
303A
304
303A

322B

209A 	
2096
209C 	
2096 	

2090
909A
304 	 _.
303A
304
304

303E
425C


3O3 A r* 8
304 	


303A

3256


I
426 A or B.

j 4270 	
! 427C 	
' 428A
5128 	
. 212 	
Faranca (inathod I
ASTM




D142B>J9(A1












038S9-44(A) . .
0659-40(8) 	








01 426-821 A)


: OS 16-621 A)
0516-62(8) 	
01339-84(C)
02330-821 A)

40. orpaga)
USGS'


1-3630-M 	

'

U3750-64 	
1-1750-64 	
t-3765-64 	
1 _ 	 _ 	

1-3753-64






1-3667-44 	
M700-64 	
1-2700-64

1-3790-64



1-3735-64 .






1 1-3640-64 	



Othar


33103'
90O 7 4

317B '•










200.7«



20074
33 089 * p 37 '

3196 '•
2007«
33.107 «
200.7.«

i 11 Afi9 1

' 33.124 .»
426C."
22BA .'«

Nota 31
                                    E-32

-------
TABLE  E-5.     (Continued)
                                                                Reference (method No. or oagei
        Parameter, units, and method
                                           EPA  1979
                                                     Standard
                                                     metnods
                                                     i6in Ed.
                                                                        ASTM
USGS'
                                                                                                         Other
   70  Thallium—Total3.  mg/L Digestion 9
     followed by:
       AA drect aspvstnn	279.1	  303A	:	
       AA furnace, or	279.2	304	
       inductively coupled plasma	,	;	  200.7 •
       Tin—Total 9.  mg/L dotation >  tot- '             ;
           by:                           •             '
       AA *wct aspiration, or	j 282.1	1 303*	I	; 1-3850-78'	:
       AA tumact	i 282.2	: 304	j	,	:
       Titanium—Total 9.  mg/L Digestion3 j             '            |                ,               ;
     followed by:
71
72.
AA dvect sspvstion or
AA furnace 	
73 TurtMWy NTU" Nephelornelnc
74. Vanadium. Tout '. mg/L: Digestion »
followed by:
AA direct aspiration
AA furnace 	

Cotonmecnc (Game acid) 	
75. Zinc-Total9. mg/L Digestion1 tot-
ISM*^Btf4 t*u>
KJWPQ afi
AA direct Mpirabon . .
AA fumtc* 	


(Ztncon) 	

283 1
2832
180 1
286 1
2862


2M1
2892




303C
304 	
214A
303C
304 	

3278 	
303A Of B
30*

32BC 	




01889-81



03373-84 Manual disiMation is not required if comparability data on representative effluent  samples are on company Me to show that
ths prekmnary  drstillatton step ia not necessary;  however,  manual distillation w*  be rrjursd to resolve any controversies.
  •Ammoraa. Automated Electrode Method. Industrial Method Number 379-75 WE. dated February 19.  1976,  Techncon
AutoAnatyzer II.  Techncon Industrial Systems, Tarrytown. NY. 10591.
  'The approved  method  is  that cited  in "Methods  for  Determination
Sediments". USGS TWRI. Book 5. Chapter A1 (1979).
  • American  National Standard on Photographic  Proceseng Effluents.  Apr. 2.  1975. Available from ANSI.  1430  Broadway.
New York. NY 10018.
  • "Selected Analytical Methods Approved and Cited by the United States Environmental Protection Agency." Supplement to
the Fifteenth Edition of Standartf Xefnuui for me £wnrwaon of Wmr *W rVjsrewerer (1981).
  10 The use of normal and  differential pulse voltage ramps to increase sensitivity and resolution is  acceptable.
  1' Carbonaceous bnchemwal oxygen demand (CBOD.) must not be confused with the traditional BOO. test which measures
"total BOO." The addition of the minftcauoH inhibitor is not a procedural option, but must M included to report jhe CBOD,
parameter. A discharger  whose permrt requires reporting ths  traditional BOO* may not  use  a  mvrficaoon tnhtotor in the
procedure for reporting tne  results. Only when a discharger's permrt specmcalty states C8OO» «  reoured. can the permittee
report data using tne nrmticaoon nr*drtor.

                                                       E-33

-------
TABLE  E-5.     (Continued)
    1 -' QIC Chemical Oxygen Demand Method. Oceanography international Corporation. S12 West Loop. P.O. Boi 2980. College
 Station. TX 77840
    1:1 Chemical Oxygen Demand. Method 8000. Hach Handbook ol Water Analysis. 1979. HICK chemical Company. P.O Box
 389. Lovetand. CO 80537
    1' The back titration method will be used to resolve controversy.
    '••Onon Research  Instruction Manual. Residual Chlorine Electrode Model  97-70. 1977. Onon Research incorporated. 840
 Memorial Drive. Cambridge. MA 02138.
    '" The approved method « mat cited m Sunava Hmthoa* for th» EamatMn ol  Wiur tna Wuifwat*. I4tn Edition.
 1976.
    IT National Council ol the Paper industry for Ar and Stream improvement, (inc.) Technical Bulletin 253. December  1971.
    "Copper. Biconchomate Method. Method 8906. Hach Handbook of Water Analysis.  1979.  Htcti Chemeil Company. P0.
 Box  389. Loveland. CO 80537
    10 After the manual doMlauon is completed, the autoanalyzer manrfoMs in EPA Methods 3353 (cyande) or 420.2 (phenols)
 are simplified by connecting the re-sample line dvactty to the sampler. When unrig the rnantoM setup shown m Method 335.3.
 the butler 6.2 should  be replaced with the butler 7.6 found m Method 335.2.
    10 Hydrogen  ion (pH) Automated Electrode Method, industrial Method Numeer 378-7SWA. October 1976. Techmcon  Auto-
 Analyzer II. Techmcon Industrial Systems. Tanytown. NY 10591.
    " Iron. 1.10-PhenanthroMne Method.  Method 8008. 1980. Hech Chemical Company. P.O. Boi 389.  Loveland.  CO 80537
    " Manganese. Penodate Oxidation Method. Method 8034. Hach Handbook of Wastewater Analysts. 1979.  pages 2-113 «na
 2-117. Hach Chemical Company. Loveland. CO 80537.
    " Goerfitz. D.. Brown. E.. "Methods  for  Analyst* of Organ* Substance* m Water." U.S.  Geotoocal Survey Techniques of
 Water-Resources Inv.. book 5. eft. A3. page 4 (1972).
    " Nitrogen. Nitnte.  Method  8507. Hach Chemical Company, P.O. Box 389. Loveland. CO 80537.
    " Just poor to dmtillation. admit the suHure-aod-preterved sample to pM 4 wrtti .1  * 9 NaOH
    '• The approved method is that cited in Sttnoiro Afemootf lor ttm ejomnitiofi ol Wtttr ana Wmittmtwr,  14th Edition The
 coionmetnc reaction « conducted at a OH  of 10.0=0.2. The approved method* «r» gtven on pp. 576-81 of the 14th Edition:
 Method  510A   tor distillation.  Method 5108 for  the manual coionmetnc procedure,  or  Method 510C tor  the  manual
 spectrophotometnc procedure.
    " R.  P.  Addnon and R. G.  Ackman.  "Direct Determination ol  Elemental Phosphorus  by Gat-Liquid  Chromatography."
 Journal of Chromttognphy. vol. 47. No. 3. pp. 421-426. 1970.
    " Approved  methods for the analysis of rtver m industrial wutewater* it concentration* of 1  mg/L and above  ire
 inadequate  where silver exist* as an inorganic haMe. Silver hahdes such as the bromide and crdonde are relatively insoluble in
 reagents such as nrtnc aod but are readily  soluble m an aqueous butter of sodium thiosurfat* tnd sodwm hydroxide to a  pH ol
 12 Therefore, for levels of stover above 1 mg/L  20 ml of sample should be dduted to 100 ml by adding 40 TIL each of 2 M
 Na,S.-O)  and 2M NaOH. Standards should  be  prepared in the  same manner. For levels of silver MOW 1 mg/L the approved
 method is satisfactory.
    " The approved method is that cited in Sonavt MtmoOs (or fne Extrrwnitori of Vtmtmt if* Wmttmittr, 15m Edition
    10 The approved method is that cited in SunOira Mtfflods lor ttm Sxtmnttori of W*M tna W*$ttwtttf 13th Edition.
    :" Stevens. H. H..  Ficke. J. P.. and Smoot. G. P.. "Water Temperature—influentiel Factors. Field Meisurement and Data
 Presentation." U.S. Geological Survey. Technique* of Water Resources investigation*. Book i. Chapter 01. 1975.
    " Zinc. Zincon  Method. Method 8009. Hach Handbook of Water Analysis. 1979. page* 2-231 and  2-333. Hach Chemical
 Company. Loveland. CO 80537.
                                                        E-34

-------
        TABLE  E-6.   LIST  OF  TEST  PROCEDURES APPROVED BY U.S. EPA
                  FOR NON-PESTICIDE ORGANIC COMPOUNDS

Note:  This table is an exact reproduction of Table 1C in 40 CFR 136.3.


1 Acenaphthene 	
2 ArimapMftyijuw
3 Acrolein
4 Acrytorntnle
5 Anthracene . 	

7 Benzidme . .
8 Benzol a ^anthracene
9 Benzo|a)pyrene
10 Benzolblfiuorantnene 	
1 1 Benzo(9 h Operyiene
1 2 Benzo(k)fluorantnene
13 Benzyl cnionde
14 Benzyl butyl phthaiate
IS Bis(2-chioroethoxy) methane
16 Bis(2-cftloroethyl) ether
17 BiK2-ethyihexyi) phthaiate
1 8 Bromodichlor orriethane
19 Bromotorm 	
20 Bromomethane
21 4-Bromopnenyiphenyi ether . . . 	
22 Caroon tetracnioode 	
23 4-Chloro-3-methylphenol 	
24 Chiorooenzene 	
25 Chioroethane 	
26 2-Chioroethviwinyi ether 	
EPA*
GC
610
610
603
603
610
602

610
610
610
610
610

606
i 611
' 611
' 606
I 601
! 601
i 601
611
601
604
601.602
i 601
i 601
lethod Number - :
GC/MS
625. 1625
625. 1625
'624. 1624
•624. 1624
625. 1625
624. 1624
'625. 1625
625. 1625
625. 1625
625. 1625
625. 1625
625. 1625

625 1625
625 1625
625. 1625
625. 1625
624. 1624
624. 1624
624. 1624
625. 1625
624. 1624
: 625. 1625
, 624. 1624
i 624. 1624
• 624. 1624

HPLC
610
610


610

605
610
610
610
610
610










OthAT







Note3. p. 1:





Note 3. p. 130:
Note 6. p
Si 02.






Note 3. p 130
Note 3. p 130.
i
i
                                  E-35

-------
TABLE E-6.  (Continued)
sarameter
27 CriiottJlorm
28 Chiorometnane
29 2-CMoronaontnaiene
30 2-CNoroontnol
31 4-Oioropntnyipntnyl ttntr
32 Orystnt 	
33 Dib*nzo(a.n)anthracan« 	
34 Oioromocnioromttnana 	 	
35 1 2-OicniorODtnztnt 	 :
36. i .3-Oicnioroo*nztfl« 	
37 i 4-OicniorODtnztfl* 	 ;
38 3.3 -OictiforoMnzidmt 	 	 i
39 OicnioroOifiuorornttfiant j
40. i i-Dicnioro*tnan« 	
41 i 2-0«ri*oro«man« 	 i
42 i 1 -Oichkxottnan* 	
43 trans* 1 2-OiCflloro*th*nt
44 2 4-Dichloropfwiol • i
45 1 2-QicfMOfOpropant
46 os-1 3-OicniOfooroDtn*
47 trftna.1 3-PichHMtiQfQoafia
49 Dictnyi pntnaiatt
49 2 4.0irn«tfiytpf»«nol
50 Dimtthyi pfwhaiat*
Si Oi-o-outyi pfitnaiatt
52 Oi-n-ociyt pfitnaiatt
53 2 4-Oinitrop'Mnel
54 2 4 Dinitrotolutrn
55 2 6"OinitfolOKj4>n*
56 Epicniorofiydnn 	
57 Etnyibtnrtnt.. . . . 	
56. Fluoranttwn* . 	
59 Fluortot
60 ^yae^'yofrt^Ty^
§1 Hnacnxxooutadicff*
62 H»iaefilofocyclootntaO«r>t
S3 "•*aeflK>fo#ifan*,
64. Id«no<1.2.3-Cd)pyrto« 	 	
65 isopftofon*
66 M*tnyttn* cfflono* 	
67 3 Mttfiyl < 0 onnropftanol 	
66 Naofttnaicn*
09 NitroMnnffM
70 I Nitroptnool
71 4-Nrtrnptwnl

73 N*NitfOMdHv0ropyla)fiww
74 N-NitroMdipMnytamnc
75 2 2*-Ovytm4l-%ftloropropan«)
76 PC8-1016
77 PCS- 1221
78 PCS- 1232
79 PCS- 1242
80 PC8-1248
81 PCS- 1254
82 PC8-1260 .. .
83 py«ac'"flfort>tQfQQ'to9ftIQ-&TGWtrt
88 112 2-T*tracniofo«ttian*
89 Tatfacfliofo
-------
TABLE E-6.    (Continued)
                                                             EPA MetrtOO Numoer • '
                    Parameter                    —	Otner
                                                       GC             GC/MS
92 1.1.1-Tncnioraetnane . . 	
93 1.1.2-Trtcnioroemane . . 	
94 Tncmoroetnene 	
95 Tncniorotluoromethane 	
96 2 < 6-Tnchlorophenol 	
97 Vinyl chloride

601 •
601 !
601 I
601 I
604 |
601

624. 1624 L
624. 1624 L.
624. 1624 (. .
624 L
625 1625 L
624 1624 j.


Not* 3 0 '30

•



    Tab* 1C NOtM
    ' All parameters «r* expressed in rmcrograms per liter (
    'The full text  o) Methods 601-613. 624. 625.  1624. and 1625. are grven at Appendix A.  "Test Procedures lor  Analysis oi
  Organic Pollutams." of this Part 136  The standardized test  procedure to oe used to  determine the method detection limit
  (MOD for these (Ml procedure* « given at  Appendn 8. "Definition and  Procedure  tor me Determination of trie Metnoo
  Detection umrt." of tmt Part 136.
    '"Method* for Benrdme: Chlorinated Organic Compound*. PemacMoropnenoi  and Petbodn m Water and  wastewater"
  U.S. Enwonmental Protection Agency. September. 1978.
    •Metnod 624  may be extended to screen  sample* for Acrotem and  Aoytonrtrte. However. «nen they are  known  to De
  preaent. tne preferred method for the*e two compounds » Metnod 603 or Method  1624
    'Method 625  may be extended to include bera**ne. neiacntorocyOopenudiene.  N-mtra*odwmemyamme. and  N-mtrosodi-
  phenyiamme. However, when they are known to be present. Method*  605. 607. and 612. or Metnod 1625.  are  preferred
  method* tor these compounds.
    • 625 Screenmo only
    •"Selected Analytical Method* Approved and Cited by the  United Slates Enwonmemal Protection Agency." Supplement to
  the Fifteenth Edrnon of Stsnuv Utthoe* lor tn» &nmn»aon ol Wtttr tna HfiammMr (1901).
    ' Each analyst must make an initial, one-am*,  demonstration ol me* aMity to generate acceptable precwon  and  accuracy
  with Method* 601-613. 624. 625. 1624. and 1625 (See Appendn A of thi* Part 136) m accordance with procedures each m
  section 8.2 ol each of these Method*. Additionally, each laboratory, on an orveomg bases must spike and analyze '0% (SS
  for Methods 624 and 625 and  100% for methods 1624. and 1625)  of aH samples to  monitor and evaluate laboratory data
  quality  in  accordance with sections 6.3 and 8.4 of these  Method*.  When  the recovery iof any parameter falls  outside me
  warning limits, me  analytical results for that  parameter m  tne un*p*ed sample are suspect  and  cannot be  reported to
  demonstrate regulatory compliance.
    NOTE: These warning limits are promulgated  as an "interim final actnn with a request lor comments."
                                                       E-37

-------
              TABLE E-7.  LIST OF TEST PROCEDURE! APPROVED
                       BY U.S. EPA FOR PESTICIDES1

Note:  This table  is an exact reproduction of Table ID in 40 CFR 136.3.
Pvanwtar nQ u
1. Alorm 	

2. Am*tryn . ... 	 	


5 Atrtim* 	 , 	
8. Aanphot m*thyt 	
7 Ba/twn
8. o-BMC 	

9. 0-8HC 	

10. 5-8MC 	 	

11 y-8HC (Lindan*) 	

12 C*ptan
13. CaiDvyi 	
14 Cmt*--* •••**•««
15 Cmoraan* 	 	

16 ChtoropropMin
17 24-O 	 ... .
18. 44-OOO 	

19. 4.4'-O06 	

20. 4.4'-OOT 	 	

ii^imil
wvinoQ
ac 	
GC/MS
GC.
TLC
oc 	
GC 	
OC 	
TLC 	
GC...: 	
GC/MS ...
GC 	
GC/MS 	
GC 	
GC/MS ..
GC 	
GC/MS ...
GC 	
TUC 	
GC
GC 	
GO-MS
TUC
GC .
GC 	
GC-MS 	
GC 	
GC/MS ...
GC 	
GC/MS 	
EPA"
808
825






808
»825
sot
825
808
•825
808
825



808
825


808
825
808
825
808
825
Sttnfr
vd
M«fv

-------
TABLE  E-7.   (Continued)
               'arametar "0/U
                                       M*moo
                   Suno-
                    4Td
                   Mtm-
                    oas
                    iStn
                    Ed
                                                                ASTM
                                                                                 Om*r
  21
  22
  23
Demeton-0
Dementon-S
Oiazinon
GC.
3C
 Not* 3. p 25:  Nota 6. p. SSt
, Not* 3. p. 25:  Not* 6. p S51
: Now 3. p.  25: Nota 4. p. 30:
   Nota 6. p. S51
24 Oicamba 	
25. Dicnlofemmon 	
26 Dicmoran 	
27 OiCOfOl... 	
28 Dtetdnn 	

29 ~ oxatf»ofi
30 Qitultoton
31 Duron 	
32 Endotutfan 1

33. Endosulfan 11 	

34 EndotuHan lutfata

35 Endrtn

36 Endnn atdenyde

37 Eihion 	
38. Panuron 	
39. Fenuron-TCA 	
40. Hepwcnior 	

41 Hepwcnior aponde .

42 isodnn 	
43. Linuron 	
44. Maiatnion 	
45 Metnocarb 	
46. Metnoxycnlor 	
47 Mexacarbata
48. Mrex 	
49. Monuron 	
50. Monuron-TCA 	
Si, Neburon 	
52. Paratnion methyl 	
53. Paratnion atnyl 	
54. PCNB 	
55. Pennane 	
mm Qmftfft m if ftm

58 Propaztne 	
59 Propnam 	
60 Propoiur 	
61 Sectnimeton
62 Siduron 	
63 Stmuine , ^ 	
94 Strooan* 	
65 Swep 	
66 245-T 	
67 2 4 5-TP (Sdvei) 	
68 Taroutriylazm*
69 Toiapnene

70 Tnfluralm

ac
GC 	
GC
GC 	
GC
GC/MS 	
GC
GC 	
TLC 	
GC 	
GC/MS 	
GC 	
GC/MS 	
GC
GC/MS
GC.
GC/MS . .
GC 	
GC/MS 	
GC 	
TLC 	
TLC 	
GC 	
GC/MS 	
GC
GC/MS
GC
TLC
GC
TLC
GC...
TLC 	
GC
TLC
TLC ....
TLC 	
GC.
GC.. .
GC 	
GC
GC..
GC 	
GC 	
TLC 	
TLC
TLC ..
TLC .
GC 	
GC
TLC
GC ..
GC 	
GC
GC 	
GC/MS ... .
GC





608
625



608
•625
606
'625
606
625
608
•625
608
625



608
625
608
625



























608
625




S09A

509A




509A

509A



S09A






S09A

509A



509A

S09A

509A



SOBA
509A
509A









509A

5098
5098

509A

509A




03086





03086

03086



03086






03086

03086





03086








03086













O3086



Nott 3 p 1 1 5
Nott 4 p 30' Nota 6 p S73
Nott 3 P 7

Nott 3 p 7* Nota 4 p 30

Nota 4 p 30' Nota 6 p S73
Nott 3 p. Note 6 p SSt.
Nott 3. p 104 Note 6 p S64
Nott 3. p. 7

Nott 3. p 7



Nott 3 p 7 Nota 4 p 30



Nota 4 p 30' Nota 6 p 573.
Nota 3 p 104- Note 6 p S64.
Nota 3 p 104- Note 6 p S64.
Nota 3 p 7- Nota 4 p 30

Nota 3 p 7' Note 4 p 30' Nota
6. p. S73.
Nota 4 p 30- NOW 6 p S73
Now 3 p 104' Note 6 p S64
Note 3 p 25- Note 4 p 30:
NOW 6. p. SSI
Now 3, p. 94- NoM 6 0 S60.
Note 3, p. 7- Note 4 p. 30.
Note 3. p. 94: Note 6. p. S60.
Note 3 p 7
Nota 3. p. 104- Note 6. p. S64.
Note 3. p. 104: Note 6. p. S6*
NoM 3, p. 104; Note 8, p. S64.
NoM 3. p 25; New 4. p. 30.
NOW 3. p. 25.
NOW 3. p. 7.

Now 3. . 83: Now 6. p. S68
Now 3. . 83: Note 6, . S68.
Net* 3. . 83: Now 6. . S88.
NOW 3. 104; NOW 6. . S64.
Now 3. . 94: Not* 6. . S50.
Now 3. . 83: Now 6. . S88.
NOW 3. 104; NOW 6. . S84.
New 3. . 83: Note 6. . S68.
NOW 3. p. 7
NOW 3. P. 104; Note 6. p. S64.
New 3. p. 115: Now 4, p. 35.
Note 3. p. 115.
New 3. p. 83: Note 6. p. S68.
NOW 3. p. 7; NOW 4. p. 30.

Note 3. p. 7

    Tibia 10 Not**
    ' PastiooM ar* listed m ttus tawa by common nam* for ma convcnwnca of the reader. AomooaJ P*»BCK»*» may be found
  und*r Tabtt iC. wfi*r* antnea v* natad by cnamtc* nam*.
                                                    E-39

-------
TABLE  E-7.    (Continued)
     • The Ml text ol methods 608 ana 625 art given at Append" A. -Test Procedures 'or Analysis of Organ* Pollutants   31
  mis  Pan  '36  Th«  standardized test procedure to oe used  10 determine tn« method detection urmt  (MOD 'or these test
  procedures is given at Appendix 9. "Definition and Procedure for tne Determination of trie Method Detection Limit", of this Pan
  •36
     '  Memoas for 9enz«Jine. Chlorinated Organic Compounds, Pemacftioropnenoi  and  Pesticides m Water and Wastewater.
  U S  Environmental  Protection  Agency.  Septemoer.  1978.  This EPA  puOtication include*  thin-layer crvomatography  (T|.C)
  methods.
     4  Methods  'or Analysis of  Organic  Suostances >n  Water." U.S.  Geological Survey.  Techniques  of Water-resources
  investigations.  Book 5. Chapter A3 (1972).
     * The method may Be extended to include a-8MC. 6-BHC. enoosulfavt I. endosuHan n. and endnn. Houwver. omen they are
  known to exist. Method 608 » me preferred method.
     ' "Selected Analytical Methods Approved and Cited  by tne United Slates Environmental  Protection Agency." Supplement to
  tne Fifteenth Edition of Stina»n] MttfioOt lor me Ettmnitxyi ol Wittr ana Wtsttunnr (i9ti)
     : Eacn analyst must make an initial, one-time, demonstration of me* aMty to generate aceeptafaM precision and accuracy
  •nth Methods 60S and  625 (See Appendn A of this Part  136) in accordance mm procedures gwen in section 8.2 of eacn of
  these methods. Additionally, eacn laooratory. on an on-going basis,  must spike and anaJyie '0% otaJi samoies analyzed with
  Method 608 or SS  of  all  samples analyzed «rtn Method 82$ to monitor and  evaluate laooraton/ data  quality m accordance
  with Sections 8.3 and 8.4 of these methods.  When tne recovery of any  parameter 'alls outside trie warning limits, tne analytical
  results for mat parameter m me unso*ed sample are  suspect and cannot be rtoorted to demonstrate regulatory compliance.
         : These warning limits are promulgated as an "interim final acton with a request for comments."
                                                           E-40

-------
TABLE E-8.  RECOHMENOEO SAMPLE SIZES, CONTAINERS. PRESERVATION.
            AND HOLDING TIMES FOR EFFLUENT SAMPLES3
Minimum
Sample Sizeb
Measurement (mL)
PH
Temperature
Turbidity
Total suspended solids
Settleable solids
Floating participates
Dissolved oxygen
Probe
Winkler
Biochemical oxygen demand
Total chlorine residual
Oil and grease
Nitrogen
Ammonia-N
Total Kjeldahl-N
Nitrate+Nitrite-N
Phosphorus (total)
Priority pollutant metals
Metals, except mercury
Mercury
Priority pollutant organic
compounds
Extractable compounds
(includes phthalates.
nitrosamines. organo-
chlorine pesticides.
PCBs, nitroaromatics,
isophorone, polycyclic
aromatic hydrocarbons.
haloether, chlorinated
hydrocarbons, phenols.
and TCOO)
Purgeable compounds
25
1.000
100
1.000
1.000
5.000

300
300
1.000
200
1.000

400
500
100
50

100
100

4.000
40
Container0
P. G
P, 6
P. G
P. G
P. G
P. G

G bottle and top
G bottle and top
P. G
P. G
G only

P. G
P. G
P. G
P. G

P. G
P. G

G only,
TFE-lined cap
6 only,
TFE-lined septum
Preaervatl ver
None
None
Cool , 4° C
Cool, 4° C
Cool . 4° C
Nona

None
Fix onsite;
store in dark
Cool . 4° C
None
Cool. 4° C
H2S04 to pH<2

Cool , 4° C
H2S04 to pH<2
Cool. 4° C
H2S04 to pH<2
Cool, 4° C
H2S04 to pH<2
Cool. 4° C
H2S04 to pH<2

HN03 to pH<2
HN03 to pH<2

Cool . 4° C
0.008X Na2S2039
Store in dark
Cool . 4° C
0.008% Na2S2039
Maximum
Holding Time
Analyze i mediately8
Measure immediately6
48 h
7 days
48 h
Analyze immedl atel ye' f

Analyze 1 mediately8
8 h
48 h
Analyze Immediately8
28 days

28 days
28 days
23 days
28 days

6 mo
28 days

7 days until
extraction
40 days after
extractl on
7 daysh

-------
TABLE E-8.  (Continued
. Minimum
Sample Size"
Measurement . (ml)
Total and fecal col i form
bacteria 2SO-500
Enterococcus bacteria 2SO-500
Container0 Preservative
P, G Cool . 4° C
0.003X Na^Oj9
P, G Cool . 4° C
0.008* ^2^2^ 2
Maximum
Holding Time
6 h
6 h
a Reference:  Adapted from U.S. EPA  (1979b), 40 CFR Part 136.

   Recommended  field  sample  sizes  for  one  laboratory  analysis.    If  additional   laboratory
analyses are required (e.g.. replicates), the  field sample size should be  adjusted  accordingly.

c P « Polyethylene: G - Glass.

° Sample preservation  should  be performed  immediately upon sample  collection.    For composite
samples, each aliquot  should be preserved at  the time of collection.  Wrier use  of an automated
sampler makes it  impossible to preserve each  aliquot, the samples should be maintained at  4° C
until compositing.

e Immediately means as  soon as possible after the sample  1s collected, general ly  within  15 mtn
(U.S. EPA 1984).

  No  recommended  holding time is given by U.S. EPA  for  floating  particulates.   Analysis  should
therefore be made as soon as possible.

' Should only be used in the presence of chlorine residual.

  Holding   time  and preservation technique  for  purgeable  compounds are based on  the use of
U.S. EPA Method 624 for screening all priority pollutant volatiles organic compounds, including
acrolein and acrylonitrile.    If analysis  of acrolein  and acryloni tri le is  found to  be of
concern, a  separate subsample should  be  preserved  by adjusting the pH  to  4-5 and the  sample
should then be analyzed by U.S. EPA  Method 603.
                                                E-42

-------
QA/QC

     QA/QC  procedures  should be  detailed  in the quality assurance  project
plan  (QAPP)  (U.S.  EPA  1979c; Tetra Tech 1987).   The  following  items should
be discussed in the QAPP:

     •    Statement and prioritization of study objectives

     •    Responsibilities   of  personnel   associated  with   sample
          collection and analysis

     •    Sampling locations, frequency, and procedures

     •    Variables  to be measured,  sample sizes, sample  containers,
          preservatives, and sample holding times

     •    Equipment checklist

     •    Sample splits or performance samples to be submitted with the
          samples

     •    Sample handling,  packaging, labeling,  and  shipping  require-
          ments

     •    Laboratories to which samples will be shipped.

Tetra Tech  (1987) provides QA/QC guidance for the following activities:

     •    Preparation for sampling program

     •    Sample collection

     •    Sample processing

     •    Sample size
                                    E-43

-------
     •    Sample containers

     •    Sample preservation

     •    Sample holding times

     •    Sample shipping

     •    Recordkeeping

     •    Labeling

     •    Custody procedures

     •    Analytical methods

     •    Calibration and preventive maintenance

     •    Quality control checks

     •    Corrective action

     •    Data reporting requirements.

Field Sampling Procedures

     For the field sampling effort, the following procedures are recommended:

     •    Establish  and implement  chain-of-custody protocols  to  track
          samples from  the point of collection to final disposition

     •    Establish and implement protocols to prepare sample containers
                                    E-44

-------
     •    Prepare  field  "blank"  samples  to  assess  potential  sample
          contamination by the sampling devices

     •    Prepare  "trip blanks"  to assess potential  contamination  by
          volatile organic analytes en  route  to the laboratory (1 trip
          blank per sample shipment)

     •    Collect replicate  samples to  assess sample precision and the
          homogeneity of samples collected

     •    Use appropriate sample collection procedures (see Table E-8).

     Volatile  organic   samples   and  split  composite  samples  should  be
collected carefully.   Grab samples for volatile  organic  analyses should be
collected  in duplicate.   Residual  chlorine  should be eliminated,  and the
volatile sample containers should be filled with  a minimum of mixing and to
capacity  leaving  no  headspace.    When  splitting  composite  samples  into
discrete  aliquots  for  analyses,  the composite sample should be mixed  to
provide  a  homogeneous mixture.   A  representative  portion of any solids in
the  container should  be  suspended  in the  composite  sample.   Composite
samples  may be  homogenized  by hand  stirring with  clean  glass  rods  or by
mechanical  stirring with teflon-coated paddles.  Metal mixing devices should
not be used.

Laboratory  Procedures

     Laboratory analytical results must be  accurate and reliable.  Laboratory
QA/QC  procedures  are  generally  specified for  each different  analytical
method,  and  the  level  of  QA/QC  and  associated  deliverables  vary  among
methods  (Tables E-5 to  E-7).  The following documentation is  required by the
analytical  laboratory  for  QA  review of  data on  organic  substances  (see
Tables E-6  and E-7):
                                    E-45

-------
     •    Initial multipoint calibration

     •    Demonstration of method proficiency

     •    Determination of method detection limit [usually 5-10 ppb for
          base,  neutral,  and  acid  organic compounds  (U.S.  EPA Method
          625);  0.005-0.10  ppb  for  pesticide/PCB  analysis  (U.S.  EPA
          Method 608); and 1-10 ppb for volatiles  (U.S. EPA Method 624)]

     •    Daily checks of calibration  and  instrument tuning

     •    Daily analysis of  method blanks  (1 blank/20 samples)

     •    Analysis  of  duplicate  samples  (minimum  of   5  percent  of
          samples  analyzed)  and conduct  of  matrix  spikes to determine
          organic  recoveries.

The following  documentation  is required by the analytical laboratory for QA
review of data on  inorganic  substances (see Table E-5):

     •    Multipoint  calibration

     •    Analysis  of reagent  blanks

     •    Matrix spikes of 0.5-5 times the sample concentration

     •    Determination of method detection  limits

     •    Analysis  of  full  method  blanks  at a minimum frequency of
          every 20  samples,  rather than reagent water blanks

     •    Verification of calibration  by analysis of standards (daily or
          with every  10 sample batches)
                                    E-46

-------
     •    Performance of duplicate analyses for a minimum of  5  percent
          of the total number of samples analyzed

     •    Use of  the method  of  standard additions for samples  demon-
          strating interferences.

Data Evaluation

     Data generated  from the  monitoring program  should be evaluated using
the step-wise approach discussed below.

1.   Assemble the original  raw data reports and the  associated  QA/QC data.
     The analytes  and analytical methods used  will  determine the  types of
     QA/QC data generated, and may include the following:

     •    Sample results

     •    Blank sample results

     •    Instrument calibrations (initial and continuing)

     •    Matrix spike/matrix spike duplicate results

     •    Surrogate recovery data

     •    Instrument tuning data

     •    Chain-of-custody records

     •    Analytical request forms

     •    Gas chromatograms

     •    Mass spectra

                                    E-47

-------
     •    Instrument detection limit determinations

     •    Serial dilution results

     •    Clean-water precision and accuracy studies

     •    Furnace atomic absorption quality control data

     •    Interference check data

     •    Laboratory control sample results

     •    Holding time documentation.

2.   Because  the  resulting  data  will  be  used   to  determine  regulatory
     compliance  of  the discharge, the  following sequence  is  recommended  to
     conduct a QA review of the data:

     •    Confirm  the sample  identifier,  container,  and  preservation
          with chain-of-custody records

     •    Confirm   the   analytical  (e.g.,  extraction  or  digestion)
          procedure used with the  procedure requested

     •    Confirm  that  an  acceptable  instrument   detection  limit  was
          achieved

     •    Confirm that the analysis proceeded  in the manner specified

     •    Confirm that  all  quality control data deliverables specified
          by the analytical protocol have been submitted

     •    Confirm that  the analysis was  performed within the specified
          sample holding time

                                    E-48

-------
Confirm that the instrumentation used was properly calibrated
initially and that the method was validated

Confirm  detection  limits, precision,  and accuracy  for  each
substance and review duplicate analysis results

Confirm  that  blank samples were analyzed  and  that  the field
sampling  and  analytical  procedures  did not contaminate  the
data

Evaluate the presence of matrix interferences through the use
of surrogate recoveries and matrix spikes

Annotate  the  data  with   appropriate  qualifiers,  and  note
deviations from prescribed methods

Detail problems associated with the analyses.
                          E-49

-------
           UPGRADING TO A FULL-SCALE SECONDARY TREATMENT FACILITY
     Data obtained  from  the monitoring program described  above  will  be used
to  determine  the  mean   and peak  concentrations  and  site-specific  toxic
pollutant removal  capabilities  for secondary treatment.   Performance of the
secondary treatment pilot plant will be closely related to the attention and
expertise of the  operator controlling  the plant.   If the pilot plant is not
properly operated,  the data will  not approximate  the removals that could be
achieved with  a  full-scale facility.   Conventional pollutant  data (e.g.,
suspended  solids,  BOD)  can be used  to determine  when  the pilot plant  is
operating  within  the  expected  design  removal  efficiencies.    The  most
important  factor  in  performing  site-specific   toxic  pollutant  removal
investigations is  to  ensure that  an acclimated biological  seed exists prior
to initiating sample  collection for pollutant  analyses.

     Plant operators  should be aware that activated  sludge microorganisms are
susceptible to biological and chemical effects that  may  kill  the organisms
or   severely  inhibit their effectiveness.   Accumulations  of  toxic waste
components (via  gradual  concentration  from continuous discharges, or sudden
slugs)  could  limit the  ability  of the activated  sludge system to  achieve
design  effluent  quality  (see Tables E-9  and E-10).  Disruptions or changes
could be found by reviewing operating records (e.g.,  settling characteristics
of secondary  sludge, species  populations  in  the MLSS).   If inhibition or
upset conditions are  found, the concentration and  source of each  pollutant of
concern should be determined.  Concentrations shown  in Tables E-9 and E-10
are  not  absolute  and   should  be  used  only   for  comparison  purposes  and
preliminary investigations.

     Toxic pollutant  removal efficiencies  at  the secondary treatment pilot
plant may be greater  than those expected  in a  full-scale secondary treatment
facility.  The pilot  plant  will be operated at a  constant flow rate  and will
not  be  subject   to  the  diurnal   and  seasonal  flow  fluctuations   normally
                                    E-50

-------
   TABLE E-9.  REPORTED VALUES FOR ACTIVATED SLUDGE BIOLOGICAL
     PROCESS TOLERANCE LIMITS OF ORGANIC PRIORITY POLLUTANTS
                                       Threshold of
Pollutant                        Inhibitory Effect (mg/L)a

Acenaphthene                             NIb at 10
Acrolein                                  NI at 62
Acrylonitrile                            NI at 152
Benzene                                     125
Benzidine                                    5
Carbon tetrachloride                      NI at 10
Chlorobenzene                             NI at 1
1,2,4-Trichlorobenzene                    NI at 6
Hexachlorobenzene                            5
1,2-Dichloroethane                       NI at 258
1,1,1-Trichloroethane                     NI at 10
Hexachloroethane                          NI at 10
1,1-Dichloroethane                        NI at 10
1,1,2-Trichloroethane                     NI at   5
1,1,2,2-Tetrachloroethane                NI at 201
Ms-(2-Chloroethyl) ether                 NI at 10
2-Chloroethyl vinyl ether                 NI at 10
2-Chloronaphthalene                       NI at 10
2,4,6-Trichlorophenol                       50
porc-Chloro-OTeto-cresol                   NI at 10
Chloroform                                NI at 10
2-Chlorophenol                            NI at 10
1,2-Dichlorobenzene                          5
1,3-Oichlorobenzene                          5
1,4-Dichlorobenzene                          5
1,1-Dichloroethylene                      NI at 10
1,2-trcrns-Dichloroethylene                NI at 10
2,4-Dichlorophenol                        NI at 75
1,2-Dichloropropane                      NI at 182
1,3-Dichloropropylene                     NI at 10
2,4-Dimethyl phenol                        NI at 10
2,4-Dinitrotoluene                           5
2,6-Dinitrotoluene                           5
1,2-Diphenylhydrazine                        5
Ethyl benzene                              NI at 10
Fluoranthene                              NI at   5
                               E-51

-------
TABLE E-9.  (Continued)
                                            Threshold of
     Pollutant                        Inhibitory  Effect  (rag/L)a

     Ms-(2-Chloroisopropyl) ether            Nlb at  10
     Chloromethane                            NI  at 180
     Bromoform                                NI at 10
     Dichlorobromomethane                     NI at 10
     Trichlorofluoromethane                   NI at 10
     Chlorodibromomethane                     NI at 10
     Hexachlorobutadiene                      NI at 10
     Hexachlorocyclopentadiene                NI at 10
     Isophorone                              NI at 15.4
     Naphthalene                                 500
     Nitrobenzene                                500
     2-Nitrophenol                            NI at 10
     4-Nitrophenol                            NI at 10
     2,4-Dinitrophenol                            1
     N-Nitrosodiphenylamine                   MI at 10
     N-Nitroso-di-N-propylamine          .     MI at 10
     Pentachlorophenol                          0.95
     Phenol                                      200
     Ms-(2-Ethyl Hexyl) phthalate            MI at 10
     Butyl Benzyl phthalate                   NI at 10
     Di-n-butyl phthalate                     NI at 10
     Di-n-octyl phthalate                    NI at 16.3
     Oiethyl phthalate                        NI at 10
     Dimethyl phthalate                       NI at 10
     Chrysane                                 NI at  5
     Acenaphthylene                           NI at 10
     Anthracene                                  500
     Fluorene                                 NI at 10
     Phenanthrene                                500
     Pyrene                                   NI at  5
     Tetrachloroethylene                      NI at 10
     Toluene                                  NI at 35
     Trichloroethylene                        NI at 10
     Aroclor-1242                             NI at  1
     Aroclor-1254                             NI at  1
     Aroclor-1221                             NI at  1
     Aroclor-1232                             NI at 10
     Aroclor-1016                             NI at  1


a Unless otherwise indicated.

b NI = no inhibition at tested concentrations.  No concentration is listed  if
reference lacked concentration data.

Reference:  U.S. EPA  (1986c).


                                     E-52

-------
TABLE E-10.  REPORTED VALUES FOR ACTIVATED SLUDGE BIOLOGICAL
  PROCESS  TOLERANCE  LIMITS OF  INORGANIC PRIORITY  POLLUTANTS
                                     Threshold of
        Pollutant               Inhibitory Effect (mg/L)
Arsenic
Cadmium
Chromium (VI)
Chromium (III)
Copper
Cyanide
Lead
Mercury
Nickel
Silver
Zinc
0.1
1
1
10
1
0.1
0.1
0.1
1
5
0.03

   Reference:   U.S.  EPA  (1986c).
                           E-53

-------
experienced  at  treatment  facilities,  nor  the  slug  loadings  and  batch
discharges which  POTWs can experience in daily operation.   In  addition,  at
the  relatively higher aeration  rates of  the pilot  plant system,  higher
degrees  of volatile  organics  stripping  may  occur, thereby  implying  higher
levels of  removal of  biodegradable material than might actually happen under
full-scale situations.
                                    E-54

-------
              DEMONSTRATING COMPLIANCE USING PILOT PLANT DATA
     The  purpose  of operating  a  secondary  treatment  pilot  plant  is  to
determine the concentrations of  toxic  substances  in  the  effluent  that would
be realized if the applicant were providing secondary treatment,  rather than
less-than-secondary  treatment  as  requested  in  the  301(h)   application.
Effluent  from  the  secondary  treatment  pilot  plant  is then  analyzed  to
determine the concentration of each toxic substance  in the  effluent.   These
concentrations define  the maximum allowable concentrations  in  the discharge
of less-than-secondary treated effluent.

     To  demonstrate  secondary equivalency,  the applicant must  demonstrate
that  the  concentration   of  each  toxic substance in the  effluent  of  the
Section  301(h)  modified  discharge  is  equal  to,  or  less than, the concen-
tration  achieved  using  the secondary treatment  pilot  plant.   For toxic
substances  whose  concentration  in  the  Section  301(h)  modified  discharge
is greater  than  the  concentration   in  the  secondary  treated  effluent,
the applicant  must  lower the concentration  using  either  or  both  of  two
approaches.    The first  approach  is  to  establish   local  limits  for  such
substances,  in  accordance with the  guidance  given above.    The  second
approach  is  to   upgrade  the treatment process  within  the  POTW.    Having
implemented  either  or  both  of  these  approaches, the applicant must  then
provide  results  of  additional   effluent  analyses to demonstrate  that  the
maximum  allowable concentrations  of toxic substances are not being  exceeded
after the proposed controls have been  implemented.
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                                 REFERENCES


American  Public Health  Association/American Water  Works  Association/Water
Pollution Control  Federation.   1985.   Standard methods  for  the examination
of water and wastewater  (16th ed).  Port City Press,  Baltimore, MD.  1268 pp.

Tetra  Tech.    1982a.    Design  of  301(h)  monitoring programs  for municipal
wastewater discharges to  marine  waters.   EPA 430/9-82-010.   Prepared  for
U.S. EPA, Office of Marine Discharge Evaluation, Washington DC.  Tetra Tech,
Inc., Bellevue, WA.   135 pp.

Tetra Tech.  1982b.   Revised Section 301(h)  technical support document.  EPA
430/9-82-011.   Prepared  for  U.S. EPA,  Office of  Water,   Washington,  DC.
Tetra Tech, Inc.,  Bellevue, WA.  248 pp.

Tetra  Tech.    1986a.    Analytical  methods  for EPA  priority  pollutants  and
301(h) pesticides  in  estuarine and marine sediments.  Final Report.  Prepared
for  the  Marine Operations Division, Office  of Marine  and  Estuarine Protec-
tion,  U.S.  Environmental  Protection  Agency.   EPA  Contract  No. 68-01-6938.
Tetra Tech, Inc.   Bellevue, WA.  120 pp.

Tetra  Tech.    1986b.   Bioaccumulation monitoring guidance:   4.  analytical
methods  for  U.S.   EPA priority pollutants and  301(h)  pesticides  in tissues
from estuarine and marine  organisms.   Final  Report.  Prepared for the Marine
Operations  Division,  Office  of  Marine  and  Estuarine  Protection,  U.S.
Environmental  Protection Agency.   EPA Contract No.  68-01-6938.  Tetra Tech,
Inc.  Bellevue, WA.   118 pp.

Tetra  Tech.    1987.    Quality  assurance/quality control (QA/QC)  for 301(h)
monitoring programs:   guidance on field and laboratory methods.  EPA 430/9-
86-004.   Prepared  for U.S. EPA,  Office of Marine and Estuarine Protection,
Washington, DC.  Tetra Tech, Inc., Bellevue, WA.  277 pp.

U.S.  Environmental Protection Agency.   1979a.  NPDES  compliance sampling
manual.  MCD-51.   U.S. EPA, Enforcement Division,  Office  of Water Enforcement
Compliance Branch, Washington, DC.   138 pp.'

U.S. Environmental Protection  Agency.   1979b  (revised March  1983).  Methods
for  chemical   analysis  of water and  wastes.   EPA 600/4-79-020.   U.S. EPA,
Environmental  Monitoring and Support  Laboratory, Cincinnati,  OH.

U.S.  Environmental  Protection Agency.   1979c.    Handbook   for  analytical
quality  control in water  a.id  wastewater  laboratories.  U.S.  EPA, National
Environmental  Research Center, Cincinnati, OH.

U.S.  Environmental Protection  Agency.   1982c.   Handbook for sampling and
sample preservation  of water  and  wastewater.   EPA 600/4-82-029.   U.S. EPA,
Environmental  Monitoring and Support  Laboratory, Cincinnati,  OH.  402  pp.

                                    E-56

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U.S.  Environmental  Protection  Agency.    1983a.   Guidance  manual  for  POTW
pretreatment program development.  U.S. EPA, Office of Hater Enforcement and
Permits, Washington, DC.  270 pp.

U.S.  Environmental   Protection  Agency.     1983b.    Procedures  manual  for
reviewing a POTW pretreatment program submission.  U.S. EPA, Office of Water
Enforcement and Permits, Washington, DC.  125 pp.

U.S.  Environmental  Protection Agency.   1984a.   NPDES  compliance inspection
manual.  U.S.  EPA,  Office  of Water Enforcement and Permits, Washington, DC.
159 pp.

U.S.  Environmental  Protection Agency.   1984b.   Report  on the implementation
of  Section  301(h).    EPA 430/9-84-007.   U.S.  EPA,  Office  of Water Program
Operations.  Washington, DC.  79 pp.

U.S.  Environmental Protection Agency.  1985a.  Guidance manual  for implemen-
ting  total  toxic  organics  (TTO) pretreatment  standards.  U.S.  EPA,  Permits
Division, Washington, DC.  86 pp.

U.S.  Environmental Protection Agency.  19855.  Guidance manual for the use of
production-based  pretreatment   standards  and  the   combined   wastestream
formula.   U.S.  EPA,  Permits  Division and  Industrial  Technology  Division,
Washington, DC.  82 pp.

U.S.  Environmental   Protection  Agency.    1986a.   Pretreatment  compliance
monitoring and enforcement guidance.   U.S.  EPA,  Office of Water Enforcement
and Permits, Washington, DC.  135 pp.

U.S.  Environmental   Protection  Agency.    1986b.   Pretreatment  compliance
inspection and audit  manual  for approval authorities.   U.S.  EPA,  Office of
Water Enforcement and Permits, Washington, DC.  107 pp.

U.S.  Environmental  Protection  Agency.   1986c.   Report to  Congress  on the
discharge  of  hazardous  wastes  to publicly  owned   treatment  works   (the
domestic  sewage  study).    EPA 530-SW-86-004.   U.S.  EPA,  Office  of Water
Regulations and Standards, Washington,  DC.  450 pp.

U.S. Environmental Protection Agency.  1987a.   Guidance manual for preventing
interference at  POTWs.   U.S. EPA, Office of Water Enforcement and Permits,
Washington, DC.  113 pp.

U.S.  Environmental  Protection Agency.    1987b.  Guidance for  reporting and
evaluating POTW noncompliance with pretreatment implementation requirements.
U.S. EPA, Office of Water Enforcement and Permits, Washington,  DC.  23 pp.

U.S.  Environmental   Protection  Agency.    1987c.    Guidance manual   on  the
development  and   implementation of  local   discharge  limitations  under the
pretreatment program.   U.S.  EPA,  Office of Water  Enforcement  and Permits,
Washington, DC.  355 pp.


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Water Pollution Control Federation.  1976.  Manual of practice No. 11 - oper-
ation of wastewater treatment plants.  Lancaster Press, Inc., Lancaster,  PA.
pp. 117-160.

Water  Pollution  Control  Federation.     1987.    Manual  of  practice  OM-9,
activated sludge.  WPCF,  Alexandria, VA,  182 pp.

Water  Pollution  Control  Federation/American  Society  of  Civil  Engineers.
1977.  Wastewater treatment  plant design.   Lancaster Press, Inc., Lancaster,
PA.  pp. 217-282.
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               ATTACHMENT 1 TO APPENDIX E

    U.S. EPA OFFICE OF WATER ENFORCEMENT AND PERMITS
PROCEDURES FOR DEVELOPING TECHNICALLY BASED LOCAL LIMITS
                     E-59

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        U.S. EPA OFFICE OF WATER ENFORCEMENT AND PERMITS PROCEDURES
               FOR DEVELOPING TECHNICALLY BASED LOCAL LIMITS
INTRODUCTION

     Publicly  owned  treatment  works  (POTWs)  which  discharge  wastewater
into marine  waters may  be  granted a  waiver under Section  301(h)  of  the
Clean Water  Act  (CWA)  from the  requirement for secondary treatment  [Sec-
tion 301(b)(l)(B)].    The  Water Quality  Act  (WQA)  of  1987  added  a  new
requirement, the  urban area pretreatment program, to Section  301(h)  of  the
CWA for  POTWs  serving a population  of  50,000 or  more with  respect to toxic
pollutants introduced by industrial  dischargers.   This provision now requires
each applicant  to demonstrate that  it  has  a pretreatment  program in  effect
for each toxic  pollutant which,  in combination with  the applicant's  own
treatment of discharges,  removes  the same amount  of a given toxic pollutant
as would  be  removed if the  applicant were  to apply secondary treatment  (as
defined  in  40 CFR  Part  133)  and if it had  no pretreatment program  for  the
toxic  pollutant.    This  new  "secondary  removal equivalency"  requirement
applies only with respect to a toxic pollutant  introduced  into a POTW by an
industrial  discharger  for which  there  is  no  "applicable pretreatment  in
effect."

     Under this new  provision,  for each toxic  pollutant  introduced  by  an
industrial  user,   the  applicant must  demonstrate either that there  is  an
applicable pretreatment requirement  in effect  or  that  it has  a secondary
removal  equivalency program for any toxic pollutant from industrial  sources
for which there  is  no  applicable  pretreatment requirement.   Applicable
pretreatment requirements  may  take  the  form  of Federal categorical pretreat-
ment standards,  local  limits  developed in  accordance with  40 CFR Part 403,
or a combination  thereof.
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     POTWs  must demonstrate  that local  limits  developed are  adequate  and
enforceable.  This new CWA provision also requires POTWs to demonstrate that
industrial  sources  are  in  compliance  with  all  of  their  pretreatment
requirements,  including  numerical standards  set  by local  limits,  and that
those requirements will be enforced.

     The following discussion provides a review of procedures for developing
technically-based  local  limits.   Further details  on  the various approaches
are provided  in  U.S.  EPA's  Guidance  Manual  on the Development and Implemen-
tation  of  Local  Discharge  Limitations  Under  the  Pretreatment  Program
(December  1987).   Questions  about this  guidance should  be directed to the
U.S.  EPA  Regional  Pretreatment  Coordinators or to  The  Office of  Water
Enforcement and Permits in Washington, DC.

OVERVIEW OF LOCAL LIMITS

     Local  discharge  limitations  are requirements developed by a POTW based
on  local  conditions  and  unique requirements  at the  POTW.  These limits are
primarily intended to protect the treatment plant from industrial discharges
which  could  interfere with POTW  treatment  processes  or pass  through  the
treatment  plant to  receiving waters  and  adversely  impact  water  quality.
Local  limits  are also designed to prevent  sludge contamination and protect
workers at the treatment plant.

     Local limits are usually developed on a chemical specific basis and are
implemented  as  requirements  that  individual  industrial  dischargers must
meet.  Once adopted, local limits are deemed to be Federal standards for the
purposes of the Clean Water Act Section 307(d) prohibition against violating
pretreatment standards [40 CFR 403.5(d) and 40 CFR 403.3(j)].

LOCAL LIMITS DEVELOPMENT APPROACHES

     U.S.  EPA's Guidance  on the Development and Implementation  of  Local
Discharge   Limitations  Under  the  Pretreatment  Program  (1987)  provides
various  methods for  calculating  local  limits.    The  predominant  approach
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used by  POTWs  and advocated in the Guidance is a chemical  specific approach
known  as  the  maximum allowable  headworks  loading  method.    This  method
involves  back  calculating  from  environmental  and  plant  protection criteria
to a maximum allowable headworks  loadings.   This  is  accomplished  pollutant
by pollutant for each  environmental  criteria or plant requirement and  the
lowest  or most  limiting  value  for each  pollutant serves  as  the  basis  for
allocation to  industry and ultimate local limits.   The steps  of the maximum
allowable  headworks loading  local  limits development process are  shown  in
Figure 1, and  discussed below.

Maximum Allowable Headworks Loadino Method

Determine Applicable Environmental Criteria--

     The  first  step  in  developing  local  limits  by  the maximum  allowable
headworks  loading method is to determine applicable environmental  criteria.
Environmental  criteria generally include NPOES permit limits,  water quality
standards  or  criteria,  sludge  disposal  requirements,  and  unit  process
inhibition   values.     The  POTW  should  use  all  applicable  environmental
criteria  when  developing  local  limits.   Other appropriate  requirements  may
include  worker   health  and  safety  criteria,  collection  system  effects,
incinerator  emission  requirements  or  other applicable  federal,  state,  or
local environmental  protection requirements.  Further information  on how to
incorporate  applicable  environmental   criteria  into  the   local  limits
development  process  is  contained in the guidance manual.

     Another  less  frequently  used environmental  criterion  is  biological
toxicity.   POTWs that  have conducted biological toxicity testing indicating
toxicity  should  develop  local  limits  to  correct  the toxicity.   Although
there  is  no method in the guidance manual  to  calculate  maximum  allowable
headworks  loadings  based on  the results  of toxicity testing, the  manual
provides  guidance  and  additional  references  on the  Toxicity  Reduction
Evaluation  (TRE)  process.
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Characterize Existing Loadings--

     Industrial Users—During the local limits development  process,  the POTW
must characterize  existing loadings to the  treatment  plant.   Local  limits
should be based on  site-specific  monitoring  data.   This  can be accomplished
by conducting  monitoring of all  industrial  users.   Either POTW  monitoring
or  self-monitoring data  are acceptable,  and information from the  POTW's
industrial waste survey may also be of use.

     Hauled Waste—If hauled wastes are accepted at the  POTW,  they  may be a
significant  source of toxic  pollutant loadings.    In  such a  case  the POTW
should consider them  as  a significant nondomestic  source  in the  determina-
tion of local limits.

     Domestic  Loadings—The  POTW  must also  characterize domestic  loadings.
Site-specific monitoring of a representative  portion of the POTW's collection
system should  form the basis  for  loadings from domestic/background  sources.
Use of literature values must be justified by the POTW.

     Treatment Plant Monitoring—The POTW must conduct sufficient monitoring
at  the  treatment   plant   to  characterize  influent,   effluent,  and  sludge
loadings.  Monitoring of  the  treatment plant influent, effluent,  and  sludge
should represent  a minimum of  5  consecutive days.    Preferably,  monitoring
should  include  data for  at  least  1  day  per month over at  least  1  yr for
metals and  other inorganic pollutants, and  1 day of  sampling per  year for
toxic pollutants [priority pollutants and Resource Conservation and Recovery
Act (RCRA) Appendix 9 constituents].

Determine Pollutants of Concern--

     As one  approach for  achieving compliance with Section 301(h)  regula-
tions,  POTWs  serving  a population  of 50,000 or more  must demonstrate that
applicable pretreatment  requirements  are  in effect for any  and all  toxic
pollutants contributed  by an  industrial  user.   Therefore,  data should  be
collected  for any  toxic  pollutants  of  concern  that could  reasonably  be
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expected to  be  discharged to the POTW In quantities that could pass through
or  interfere with  the POTW treatment  process,  contaminate the sludge,  or
jeopardize worker health  and safety or the collection system.

     The POTW  should  perform  at least one priority pollutant  scan  and one
RCRA  Appendix  9  scan to identify potential  pollutants  of concern  in the
influent,  effluent,  and  sludge.    The POTW  must then  address all  toxic
pollutants   (40  CFR  401.15)   that are  identified  in   any  analysis  above
detection limits by developing a local  limit for each pollutant.

Calculate Maximum Headworks Loadings—

     The  POTW  must calculate  the maximum  amount (Ib/day)  of each  toxic
pollutant contributed  by an  industrial  user or received at the headworks of
the  treatment  plant that will  allow the  POTW to  achieve all  of  the above
applicable  environmental  criteria.    If the  POTW does  not calculate the
maximum allowable headworks  loading to the POTW for each toxic pollutant, it
must  provide justification  why it  has not  done  so.    The nonconservative
pollutants   (volatiles)    require  special   consideration   when  conducting
headworks analysis  (e.g.,  alternative formulas and allocation methods).  All
calculations should be consistent  with the approach outlined in the guidance
manual.

     During  this step of the  local  limits  development process,   the POTW
should demonstrate  that  an acceptable mass balance exists between the actual
loadings  of pollutants   at  the  headworks  and  the  estimated   loadings  of
pollutants  from  specific source  discharges.   This  mass  balance  can  be
accomplished  by  calculating  the actual  loading  of  each pollutant  from
influent  monitoring  data and   comparing  this value  with  the sum  of the
estimated loadings  from  all  individual sources (e.g.,  domestic, industrial,
hauled  waste).    The  resulting  calculated  loadings  from  various  sources
should be within 80 to 120 percent of the actual total  influent loading and
flow.
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Calculate Allowable Industrial Loadings—

     Once the  POTW has calculated the maximum allowable headworks  loading,
a safety factor must be applied  and  the  value  discounted for  domestic/back-
ground  loadings  in  order  to determine  the  maximum allowable  allocation
available  for  industrial  users.    A  safety  factor  is  incorporated  into
the calculations  to  allow  for  future  industrial   growth  and  other  dis-
crepancies  that  may  enter  into the  calculations   because  of  the use  of
default  data  or  variations  in  analytical  procedures.    The  POTW  should
provide  justification  for  the  selected safety  factor,  which will  usually
range from 10 to 30 percent.

Allocate Allowable Industrial Loading--

     After  the POTW  has  calculated the  allowable  industrial loading,  the
method chosen  to  allocate this  loading  depends  on  the number and  types  of
industrial users  and the method  of  application  (permits, contract,  or sewer
use  ordinance) employed  by  the POTW.    Where  the current  loading of  a
pollutant exceeds the maximum allowable  headworks  loading,  the  POTWs  must
establish  a  local  limit  to reduce  loadings  to within  the  range of  the
maximum allowable headworks  loading.  Where the current loading is far below
or  approaches  the maximum  allowable headworks  loading, the  POTW  must  set
industrial discharge limits  at current loadings to maintain  the status quo.

     The  POTW should  ensure that  it has  selected  local  limits  that  are
reasonable.    All  local  limits  should be  at  or  above detection  limits  and
should not  be so lenient  as to  provide industry additional  opportunity to
pollute or encourage discharge of hazardous waste to the POTW.

Revise Local Limits--

     Many variables on  which these  local limits calculations  are based may
vary with time.  Local limits must be revised on a periodic  basis to reflect
changes  in  conditions  or assumptions.   Conditions which might  require that
local limits  be  revised include  but are not  limited to  changes  in environ-
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mental  criteria,  availability of  additional  monitoring data,  changes  in
plant processes, and changes in POTW capacity or configuration.

Implement Local  Limits--

     Once  local  limits  have  been  developed,  they  must  be  effectively
implemented.    Local   limits  should  be  incorporated   into  the  sewer  use
ordinance or some form of  individual control mechanisms.

OTHER LOCAL LIMITS APPROACHES

     Other  methods of  local  limits  development  have  been  used by  POTWs.
They  include  the collection  system approach,  industrial  user  management
practice  plans, and  case-by-case discharge  limits.   These approaches  are
briefly described  below.   U.S. EPA has  published  extensive  guidance  on the
development and implementation of local  limits.  Further information on each
of these  methods and the  maximum allowable headworks  loading  method  can be
found in  the Guidance  Manual on the Development and Implementation  of Local
Discharge Limitations Under  the Pretreatment Program (U.S. EPA 1987).

Collection System Approach

     To  apply   this method,  the POTW  identifies  pollutants  that may cause
fire  and explosion  hazards  or other  worker  health  and safety  concerns.
Pollutants  found  to  be  present  are  evaluated  for  their  propensity  to
volatilize  and are  simplistically  modeled   to  evaluate  their  expected
concentration  in  air.   Comparisons  are made  with worker  health  exposure
criteria  and lower explosive limits.   Where values are of concern,  the POTW
may  set  limits  or require  development  of management  practices  to control
undesirable  discharges.    The collection system approach may  also  consider
the prohibition of pollutants  with specific flashpoints to prevent discharge
of ignitable wastes.
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Industrial User Management Practice Plans

     This  approach  consists  of POTWs requiring industrial users  to develop
management  practices  as  enforceable  pretreatment  requirements  for  the
handling  of  chemicals and wastes.    Examples  of management  practice plans
include chemical  management  practices,  best management practices,  and spill
prevention plans.   Management practice plans  are usually  narrative local
limits.

Case-bv-Case Discharge Limits

     In  this  approach  a  POTW  sets  numeric  local  limits   based on  best
professional  judgment and on  available technologies  that  are known  to be
economically feasible.   This approach is most often  used  when insufficient
data are available to employ the other methods noted above.
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          ATTACHMENT 2 TO APPENDIX  E

U.S. EPA GUIDANCE MANUAL ON THE DEVELOPMENT AND
 IMPLEMENTATION OF LOCAL DISCHARGE LIMITATIONS
         UNDER  THE  PRETREATMENT  PROGRAM
                      E-68

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            APPENDIX F
WATER QUALITY-BASED TOXICS CONTROL

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                     WATER QUALITY-BASED  TOXICS  CONTROL
     Most   applicants   for  Section  301(h)   modified  NPDES  permits  must
demonstrate satisfactorily to  the  U.S.  EPA that discharge  from the POTWs to
the marine  or estuarine waters is  in compliance with Section  301(h)  of the
Clean  Water  Act  (CWA).    POTWs  must  enforce  all  applicable  industrial
pretreatment   requirements   and  demonstrate   the   effectiveness  of  both
industrial  and nonindustrial  source control  programs.   (Small dischargers,
with  service  area  populations  of  less  than  50.000 people  and  average dry
weather  flows of less  than  5.0 MGD, are  exempt  from effluent analysis and
industrial  pretreatment requirements if they can certify that there  are no
known or suspected  sources of  toxic pollutants  or  pesticides  to the POTW.)
Section  301(h) industrial source  control  programs  must be  consistent  with
pretreatment  regulations  and  NPDES permit  requirements.   Under Sections 308
and 402  of the  CWA, NPDES  permit applicants  [including 301 (h)  POTWs] are
required  to  collect effluent  chemical  (and  possibly  toxicity)  data and
receiving  water  biological   data   to  assure  compliance with state  water
quality  standards.   [If no state  standards have been developed for specific
pollutants  at  the time  of permit  issuance, small and large dischargers must
then meet  U.S. EPA's marine  water quality criteria  at  the  boundary  of the
zone of  initial dilution  (ZID).]

     In  1984,  U.S.  EPA  (1984)  recommended  that  whole-effluent  toxicity
testing  be  used  as a  complement   to chemical-specific  analyses  to  assess
effluent  discharges  and determine NPDES  permit  limitations.    [U.S. EPA
developed this approach  because  of certain disadvantages of  the chemical -
specific  techniques (i.e.,  the difficulty  in  identifying  all  potentially
toxic  pollutants;   the  antagonistic,  synergistic,  or  additive  effects  of
toxic pollutants;  and  the  possibility  of  complex  chemical  interactions).]
The integrated approach  is  recommended to  assure  the  attainment  of water
                                    F-l

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quality  standards,  to protect designated water uses, and to  provide a tool
to  control  pollutants  beyond the CWA  technology-based  requirements [e.g.,
Best Available Technology Economically Achievable (BAT)].

     The  Water Quality  Act   (WQA) of  1987  also emphasized  the need for an
integrated   approach   of  whole-effluent  and  chemical-specific  analyses.
Congress  required  U.S.  EPA  to report  on  methods for  establishing  and
measuring water quality  criteria for toxic  pollutants  through the  use of
biological   monitoring  and   assessment  methods,   and   pollutant-specific
analyses.    The  WQA  also  signalled  a  shift  in  emphasis   from  discharge
requirements   that   were  based  primarily  on  technology-based  pollution
controls  to  requirements  that  combined both  technology-based  and  water
quality-based pollution  controls.

     In  1985,  U.S.  EPA's Office of Water Enforcement and Permits (OWEP) and
the Office  of  Water Regulations and Standards (OWRS) prepared the Technical
Support  Document for  Voter  Quality-based Toxics Control (U.S.  EPA 1985a).
Guidance  was provided on  the implementation of a  biomom'toring  policy for
the  assessment  and  control  of toxics  using  both the  chemical-specific
approach  and the whole-effluent toxicity approach.   The chemical-specific
approach  uses  water quality  criteria or state standards to  limit  specific
pollutants  directly.   The whole-effluent toxicity approach,  as described in
the technical support  document predominantly  for non-marine waters,  involves
the  use  of test  organisms  [e.g.,  Daphnia  spp.  (water flea),  Pimephales
Promelas  (fathead minnow)] that are  exposed to  serial dilutions of municipal
or  industrial  effluent/receiving water  to  measure acute  (rapid  response)
and/or  chronic (long  term  response) toxicity.   The document also  provided
guidance  for each  step  in  the  water-quality based  toxics  control   program,
including the  development of water quality standards and criteria,  effluent
characterization,  health  hazard assessment,  wasteload  allocation, permit
requirements, and compliance monitoring.

     In  1985, the U.S. EPA also  issued a manual  that  established standardized
methods  for measuring the  acute toxicity of  effluents to  freshwater and
marine  organisms  (U.S. EPA  1985b)  and  the  chronic toxicity of effluents to
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freshwater  organisms  (U.S.   EPA 1985c).    In  1988,  U.S.   EPA  released  a
document  that  established standardized methods  for estimating  the chronic
toxicity  of effluents to  marine and  estuarine  organisms  (U.S.; EPA 1988).
Chronic toxicity test methods were provided for five species:  the sheepshead
minnow  (Cyprinodon  variegatus),  the inland  silverside (Menidia  beryllina),
the mysid  (Mysidopsis  bahia),  the sea urchin (Arbacia punctulata)   and the
red macroalga  (Champia parvula).    However,  because  these  tests  use  non-
indigenous  species  to  estimate  the   chronic  toxicity  of  effluents  and
receiving  waters  to marine  and  estuarine  organisms,  test  results  may not
necessarily  reflect  actual  field  conditions  within  or  near  the  ZID.
Moreover,  test results may  not  accurately represent impacts of  pollutant
discharges on balanced indigenous populations (BIPs).

     U.S.  EPA  developed  a permit  writer's guide (U.S. EPA  1987)  to assist
state and  Federal  NPDES permit  writers in establishing water quality-based
permit  limits  for  toxic  pollutants.   To meet  these water  quality-based
limits,   the U.S.  EPA is  continuing to develop  criteria  that  will assist
states  in  establishing their water quality standards and  effluent permit
limitations.   The U.S. EPA  criteria under  development include  recommended
magnitudes, durations, and allowable frequencies  of exceedance of pollutant
concentrations for both  acute and chronic  biological  effects.   POTW permit
limits on  effluent toxicity  could  be imposed,  and the NPDES permittee would
be required to conduct a  toxicity  reduction evaluation (TRE) and implement,
if necessary, a toxics control program (TCP) (U.S. EPA 1985a, 1987).

     The TRE, a critical  component of the TCP, must be conducted to  identify
effluent toxicity  sources,  to determine   (if possible) specific pollutants
responsible for the  toxicity,  and to  identify source  control  options.   The
TRE includes a  review of the magnitude and extent  of the  toxicity problem,
the discharge characteristics, the receiving water characteristics, the need
for additional  monitoring to determine water quality/toxicity effects   and
chc other potential point  and nonpoint toxicity  sources  in  the POTW service
area.
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     Because  all  NPDES-permitted discharges  are  unique,  no single effluent
TRE  procedure is applicable  to  every case.  A TCP must  be developed  on an
individual case-by-case  basis,  and  must include an evaluation of the impact
of 1) the  existing  POTW wastewater treatment process,  2)  point and nonpoint
contributors  to  the  POTW influent,  3) types  of industries  in the  POTW
service  area,. 4) the variability,  toxicity, and  treatability  of chemicals
in the  effluent;  and 5)  the variability  in species sensitivity based on
whole-effluent  toxicity  test results.    Either  technology-based or  water
quality-based) source control options also  need to be evaluated to determine
their effectiveness  in reducing effluent toxicity and alleviating the water
quality violations.
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                                 REFERENCES


U.S. Environmental Protection Agency.   1984.   Development of water quality-
based permit  limitations  for toxic pollutants; national .policy    U.S.. EPA,
Washington, DC.  Federal Register Vol. 49, No. 48.  pp. 9016-9019.

U.S. Environmental  Protection Agency.   1985a.   Technical  support'document
for water  quality-based toxics  control. EPA 440/4-85-032.   U.S.  EPA Office
of Water, Washington, DC.  74 pp. + appendices.

U.S. Environmental  Protection Agency.   1985b.   Methods for  measuring the
acute toxicity  of  effluents  to freshwater and marine organisms.  EPA 600/4-
85-013.   U.S. EPA Environmental Monitoring  and  Support Laboratory, Cincin-
nati, OH.

U.S.  Environmental  Protection   Agency.    1985c.    Short-term methods  for
estimating  the  chronic  toxicity  of  effluents   and  receiving  waters  to
freshwater organisms.   EPA 6QO/4-85-014.   U.S. EPA Environmental  Monitoring
and Support Laboratory, Cincinnati, OH.

U.S.  Environmental   Protection  Agency.   1987.    Permit  writer's  guide  to
water  quality-based  permitting  for  toxic  pollutants.    EPA  440/4-87-005.
U.S. EPA Office of Water, Washington, DC.

U.S.  Environmental  Protection  Agency.    1988.     Short-term methods  for
estimating the  chronic  toxicity  of effluents  and receiving waters to marine
and  estuarine  organisms.    EPA  600/4-87-028.    U.S.  EPA  Environmental
Monitoring and Support  Laboratory, Cincinnati, OH.
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