CONSTRUCTION GRANTS PROGRAM VOLUME I
INFORMATION
EPA-430/9-76-017o
FEDERAL GUIDELINES
STATE AND LOCAL
PRETREATMENT PROGRAMS
JANUARY 1977
U.S.ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF WATER PROGRAM OPERATIONS
MUNICIPAL CONSTRUCTION DIVISION
WASHINGTON, D.C. 20460
MCD-43
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NOTE
To order this publication, MCD-43, Federal Guidelines;
State and Local Pretreatment Programs, (3 volumes),
write:
General Services Administration (8FFS)
Centralized Mailing Lists Services
Bldg. 41, Denver Federal Center
Denver, Colorado 80225
Please indicate the MCD number and title 'of publication.
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CONSTRUCTION GRANTS PROGRAM VOLUME!
INFORMATION
EPA-430/9-76-017a
FEDERAL GUIDELINES
STATE AND LOCAL
PRETREATMENT PROGRAMS
JANUARY 1977
U.S.ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF WATER PROGRAM OPERATIONS
MUNICIPAL CONSTRUCTION DIVISION
WASHINGTON, D.C. 20460
MCD-43
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U.S. ENVIRONMENTAL PROTECTION AGENCY
FOREWORD
In response to the Federal Water Pollution Control Act Amendments
of 1972 (P.L. 92-500), this country has undertaken an unprecedented
program of cleaning up our Nation's waters. There will be a substantial
investment by Federal, State, and local governments as well as by private
industry in treatment works to achieve the goals of the Act. It is
important that this investment in publicly owned treatment works (POTW's)
be protected from damage and from interference with proper operation,
and that receiving waters be protected from pollutants which may pass
through the POTW.
These guidelines were developed by the Environmental Protection
Agency in accordance with Section 304(f) of the Act for the purpose of
assisting States and municipalities in carrying out programs under
Section 402 including NPDES permit requirements. It is important to
note the clear requirements in the Act that there be both national
pretreatment standards, Federally enforceable, and pretreatment guide-
lines to assist States and municipalities in developing local pretreat-
ment requirements. The Environmental Protection Agency encourages the
establishment of local pretreatment requirements, tailored-to local
conditions.
The guidelines are a revision of the previous guidelines, "Pre-
treatment of Pollutants Introduced Into Publicly Owned Treatment Works."
Contained in this revision is additional technical information on
pollutants which may interfere with or pass through publicly owned
treatment works. Also, guidance is presented to assist State and local
governments in developing their own pretreatment programs to comply with
NPDES permit conditions. The guidelines are the result of extensive
reviews and numerous field trips and discussions with EPA Regional
Offices, industry, city, regional, State and interstate agencies. We
are extremely grateful for the cooperation of those who assisted in the
preparation of the guidelines.
/s/ John Quarlsg
DEC 2 Z &/b The Administrator
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TABLE OF CONTENTS,
VOLUME I
Title
SECTION A - INTRODUCTION.
Purpose A-l
Background A-l
Authority A-2
Federal Pretreatment Standards A-3
Planning Agencies & Pretreatment Responsibility A-5
Effluent Limitations for POTWs A-6
Organization of Guidelines A-8
SECTION B - MANAGEMENT OF A CONTROL PROGRAM
Purpose B-l
Organizational Structure B-3
Financial Aspects B-13
Policy B-14
Public Relations B-17
SECTION C - LEGAL ASPECTS OF A CONTROL PROGRAM
Introduction C-l
Legal Authority C-l
Sewer Use Ordinances C-3
Recommended Ordinance for Industrial Use of C-5
Publicly Owned Sewerage Facilities
SECTION D - MONITORING
Functions of a Monitoring Program D-l
Field Considerations in Monitoring D-9
Laboratory Considerations in Monitoring D-18
SECTION E - POLLUTANTS WHICH INTERFERE WITH PUBLICLY
OWNED TREATMENT WORKS
Introduction E-l
Materials Which Inhibit Biological Treatment Works E-l
Other Substances Which Interfere with POTW E-45
Facilities
Environmental Considerations E-48
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TABLE OF CONTENTS (Continued)
VOLUME I
SECTION F - REMOVAL AND PASS THROUGH OF POLLUTANTS
IN PUBLICLY OWNED TREATMENT WORKS
Introduction F-l
Data Collection F-2
Data Analysis F-4
SECTION G - GLOSSARY G-l
SECTION H - ACKNOWLEDGMENTS H-l
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TABLE OF CONTENTS
VOLUME II
Title page
APPENDIX 1 - PRETREATMENT STANDARDS
APPENDIX 2 - SECONDARD TREATMENT INFORMATION
Secondary Treatment information 2-1
APPENDIX 3 - TEST PROCEDURES FOR ANALYSIS OF
POLLUTANTS
Guidelines Establishing Test Procedures for 3-1
Analysis of Pollutants
APPENDIX 4 - EFFLUENT GUIDELINES AND STANDARDS
Pretreatment Standards for Oil and Grease 4-1
APPENDIX 5 - POLLUTANT INTERFERENCE DATA
Pollutant interference Data 5-1
APPENDIX 6 - POLLUTANT REMOVAL AND PASS THROUGH DATA
Computer Report No. 1 - Summary of POTW Removal 6-1
Data by EPA Region
Computer Report No. 2 - POTW Categorization 6-2
Computer Report No. 3 - POTW Removal Data, 6-4
Reference Information
Computer Report No. 4 - POTW Removal Data Analysis, 6-10
24 hr. Composite - 6 Hr. Simultaneous Composite,
Comparison of Results
Computer Report No. 5 - POTW Removal Data Analysis, 6-16
by Plant Category
Computer Report No. 6 - Summary of POTW Removal 6-22
Data
Computer Report No. 7 - POTW Effluent Data Analysis 6-30
Computer Report No. 8 - Summary of POTW Effluent 6-37
Data
Table 6-1 - Cumulative Frequency Distribution of 6-45
Removal Data
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TABLE OF CONTENTS (continued)
VOLUME II
Table 6-2 - Cumulative Frequency Distribution of 6-47
Effluent Data
Evaluation of Limited Data 6-49
APPENDIX 7 - ANNOTATED BIBLIOGRAPHY
Section A - Introduction 7~1
Section B - Management of a Control Program 7-11
Section C - Legal Aspects of a Control Program 7-19
Section D - Monitoring 7-28
Section E - Pollutants which Interfere with 7-59
Publicly Owned Treatment Works
Section F - Removal of Pollutants in Publicly 7-94
Owned Treatment Works
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TABLE OF CONTENTS (Continued)
VOLUME III
APPENDIX 8
Title Section
Introduction i
Code of Federal
Regulations (CFR
Industry Description Number)
Dairy Products 405 1
Grain Mills 406 2
Canned and Preserved Fruits
and Vegetables 407 3
Canned and Preserved Seafood 408 4
Sugar 409 5
Textiles 410 6
Cement 411 7
Feed Lots 412 8
Metal Finishing and
Electroplating 413 9
Organic Chemicals 414 10
Inorganic Chemicals 415 11
Plastics and Synthetic
Materials 416 12
Soap and Detergents 417 13
Fertilzer 418 14
Petroleum 419 15
Iron and Steel 420 16
Non Ferrous Metals 421 17
Phosphates 422 18
Steam Electric Power Plants 423 19
Ferro Alloys 424 20
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TABLE OF CONTENTS(Continued)
VOLUME III
APPENDIX 8
Leather 425 21
Glass 426 22
Asbestos 427 23
Rubber 428 24
Timber 429 25
Pulp, Paper and Paperboard 430 26
Builders Paper and Roofing Felt 431 27
Meat Products 432 28
Water Supply 437 29
Misc. Foods and Beverages 438 30
Misc. Chemicals 439 31
Auto and Other Laundries 444 32
Paint and Ink Formulation 446&447 33
Steam Supply and Noncontact
Cooling 449 34
Index
List of References
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LIST OF TABLES
VOLUME I
Table Title page
C-l Calculation of Maximum Allowable industrial C-10
Discharge Concentrations - County Sanitation
Districts of Los Angeles County
E-l Threshold Concentrations of Inorganic Pollu- E-7
tants that are Inhibitory to Biological
Treatment Processes
E-2 Threshold Concentrations of Organic Pollu- E-28
tants that are Inhibitory to Biological
Treatment Processes
F-l Distribution of POTW Data by Plant Process F-6
F-2 Removal Data Summary for Primary, Trickling F-8
Filter and Activated Sludge Plants (Selected
Parameters)
F-3 Effluent Data Summary for Primary, Trickling F-9
Filter and Activated Sludge Plants (Selected
Parameters)
F-4 Characterization of Primary and Biological F-10
Plant Performance
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LIST OF FIGURES
VOLUME I
Figure Title
B-l
Conceptual organization of an industrial
Wastewater Control Program
B-2 Typical Organization of a Large System
B-3 Typical Organization of a Medium Size System
B-4 Typical Organization of a Small System
D-l Monitoring Feedback System
F-l Cumulative Frequency Distribution Curves
thru for Effluent Concentration and Percent
F-17 Removal of the following parameters:
F-l Cadmium
F-2 Chromium
F-3 Lead
F-4 Mercury
F-5 Copper
F-6 Nickel
F-7 Zinc
F-8 Iron
F-9 Manganese
F-10 Total Phosphates
F-ll Total Kjeldahl Nitrogen
F-12 Ammonia
F-13 Phenolics
F-14 Total Organic Carbon
F-15 Chemical Oxygen Demand
F-16 Suspended Solids
F-17 Biochemical Oxygen Demand
B-6
B-ll
B-12
D-2
F-13
F-14
F-15
F-16
F-17
F-18
F-19
F-20
F-21
F-22
F-23
F-24
F-25
F-26
F-27
F-28
F-29
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SECTION A
INTRODUCTION
Purpose
Background
Authority
Federal Pretreatment Standards
planning Agencies & Pretreatment Responsibility
Effluent Limitations for POTWs
Organization of Guidelines
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SECTION A
INTRODUCTION
Purpose
These guidelines are established to assist municipalities,
States, Federal agencies, and others in developing require-
ments for the pretreatment of wastewaters which are intro-
duced into publicly owned treatment works (POTW's). This
document is a revision of an earlier publication dated
October 1973, and presents a compilation of technical and
administrative information relative to pretreatment and the
control of industrial wastewaters in publicly owned systems.
Information contained herein is designed to provide the
operators of POTW systems with a sound basis for determining
the impact of non-residential wastewaters, as well as
appropriate approaches for controlling pollutants from these
sources.
Additionally, this document provides guidance helpful
in complying with those special conditions of the National
Pollutant Discharge Elimination System (NPDES) permits issued
to POTW's that relate to non-residential wastewaters. Tech-
nical aspects, including data on pollutants which may inter-
fere with the operation of POTW's, and the removal of pollu-
tants in treatment facilities are covered in detail. Legal
considerations encompassing methods for establishing pollu-
tant limitations and a recommended ordinance for industrial
use of sewers are also addressed. Additionally, information
on the management and monitoring requirements of an industrial
wastewater control program and summaries of the wastewater
characteristics and pretreatment information for major
industrial categories are included.
In summary, this document provides guidance to State
and local governments concerned with implementing pretreat-
ment programs. The guidelines are subject to modification
as a result of EPA review of its policy in pretreatment.
Background
Up until 1972, the emphasis in Federal legislation had
been oriented toward water quality standards. With the
enactment of the Federal Water Pollution Control Act Amend-
ments of 1972 (Public Law 92-500) a number of fundamental
changes in the approach to achieving clean water were
instituted. One of the most significant changes was from an
emphasis on the ambient quality of streams to direct control
of effluents through the establishment of regulations and
standards which form a basis for the issuance of discharge
permits. In addition, the 1972 Amendments required the
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development of pretreatment guidelines and standards to pro-
vide a uniform approach to the control of industrial pollu-
tants introduced into POTW1s.
Public Law 92-500 established a national system for
preventing, reducing, and eventually eliminating water
pollution. By the creation of the National Pollutant Dis-
charge Elimination System (NPDES), the Act has required that
all point sources (including POTW's) obtain a permit for the
discharge of wastewaters to the navigable waters of the
United States.
The Act further requires that as a minimum intermediate
objective, all point sources other than POTW's treat their
wastewaters by the application of the best practicable con-
trol technology- Subsequently, the minimum requirement for
industrial wastewaters would be the application of best
available treatment technology. For POTW's the initial
objective is secondary treatment, as outlined in "Secondary
Treatment Information" promulgated by the Environmental
Protection Agency on August 17, 1973 (Appendix 2).
As an additional measure designed to protect the
quality of navigable waters, Public Law 92-500 also contains
provisions that require regulating the pretreatment of non-
domestic wastewaters contributed to POTW's. In the following
section, those portions of the Act that pertain to pre-
treatment, including the section providing authority for
the development of this document are discussed.
Authority
Under Title III of the Act, "Standards and Enforcement,"
several sections are included that specifically refer to the
pretreatment of pollutants introduced into POTW's. Authority
for development and revision of this guidelines document is
contained in Section 304(f) which states:
"For the purpose of assisting States in carrying
out programs under section 402 of this Act, the
Administrator shall publish and review at
least annually thereafter and if appropriate,
revise guidelines for pretreatment of pollutants
which he determines are not susceptible to treat-
ment by publicly owned treatment works. Guide-
lines under this subsection shall be established
to control and prevent the discharge into the
navigable waters, the contiguous zone, or the
ocean (either directly or through publicly owned
treatment works) of any pollutant which interferes
with, passes through, or otherwise is incompatible
with such works."
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These guidelines should not be confused with pretreat-
ment standards for both existing and new sources, promulgated
under the authority of Sections 307 (b) and 307(c) respectively.
Section 307(b) is directed toward existing sources, and
states:
"The Administrator shall publish proposed
regulations establishing pretreatment standards
for introduction of pollutants into treatment
works which are publicly owned for those
pollutants which are determined not to be sus-
ceptible to treatment by such treatment works
or which would interfere with the operation of
such treatment works."
Under the authority of this Section, the EPA promulgated on
November 8, 1973, general pretreatment standards, which are
included in Appendix 1 of this document. These pretreatment
standards set forth rules and regulations designed to protect
POTW's from the possible harmful effects of industrial waste-
waters introduced into such systems. In addition to the
general pretreatment standards, this section also provides
authority for the development of pretreatment standards for
specific major industrial categories of non-residential
contributors. Similarly, Section 307(c) authorizes the
promulgation of pretreatment performance standards for new
sources.
The distinction between pretreatment standards and
pretreatment guidelines must be emphasized. This document,
as indicated, is strictly advisory, for the purpose of pro-
viding pretreatment assistance to interested parties. As
such, these guidelines only recommend approaches to developing
pretreatment policy. In contrast, the pretreatment standards
as promulgated under Section 307 of the Act, represent rules
and regulations which are enforceable by the Federal
government.
Federal Pretreatment Standards
EPA has issued general standards for pretreatment of
pollutants introduced into POTW's (Appendix 1). Subsequent
to the promulgation of pretreatment standards on November 8,
1973, the Agency has proposed and promulgated numerous
pretreatment standards relative to specific industry cate-
gory wastewater discharges for both existing sources and
new sources. As a result of these proposed and promulgated
regulations, the Agency has received numerous indications
that its pretreatment procedures, both for the establishment
of and for the enforcement of pretreatment standards, and
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the pretreatment standards themselves were not clearly
understood by many segments of the general public. _For this
reason, the Agency has decided to clarify and simplify_the
existing pretreatment standards. This will be accomplished
by proposing new general pretreatment regulations to replace
the existing standards contained in Appendix 1. It is antici-
pated that the proposed standards will be published in the
Federal Register in the near future. At that time the
proposed regulation and an appropriate discussion will be
incorporated in these guidelines.
The pretreatment standards are intended to be national
in scope. In many cases, it will be necessary for a State
or a municipality to supplement the Federal standards with
additional pretreatment requirements which take into account
local conditions. Factors such as stringent water quality
standards reflected in the POTW1s NPDES permit or character-
istics of the treatment process may necessitate more restric-
tive pretreatment requirements in specific instances. The
Federal pretreatment standards do not preclude municipalities
and States from establishing pretreatment standards of their
own, not in conflict with any Federal pretreatment standard,
as stated in Section 307(b)(4) of P.L.92-500. State or
local standards may be necessary to control types, flows,
concentration and variability of industrial and commercial
discharges into municipal treatment works.
There may be specific situations when the Federal pre-
treatment standards will not be sufficient to protect the
operation of the publicly owned treatment works. This might
be the case when the quantity of a pollutant not susceptible
to treatment in a POTW, introduced by a major contributing
industry, would result in a concentration of the pollutant
in the influent to the treatment works which would inhibit
the performance of the treatment process. In such a case,
the municipality would have to supplement the Federal standards,
Additionally, State or local pretreatment standards may be
necessary for pollutants susceptible to treatment in a POTW.
Pretreatment of wastewaters containing susceptible pollutants
may be necessary in the form of spill protection or flow
equalization in order to ensure compliance with the Federal
pretreatment standards and permitted effluent limitations.
EPA has been, and is currently in the process of promul-
gating rules and regulations setting forth effluent limitations
guidelines and standards of performance for the treatment of
specific industrial wastes discharged to navigable waters.
In pursuit of this goal, EPA has categorized wastewater pro-
ducing commercial activities, and has, on an industry by
industry basis, published effluent standards in the Federal
Register (40 CFR 400 series). In each of these rules and
regulations for specific major industries, pretreatment
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standards are either proposed or promulgated in addition to
the requirements for wastewaters which are directly dis-
charged. To date, pretreatment standards for new sources
have generally been established in final form, while final
rules and regulations for the pretreatment of existing
sources have only been partially promulgated. Pretreatment
standards for existing sources within fifteen major indus-
trial categories were promulgated on February 11, 1975
(Appendix 1), with approximately twenty additional indus-
trial pretreatment standards still pending. The pretreat-
ment standards published for the first fifteen industries do
not establish limitations on pollutants contributed to
municipal systems because the pollutants from these indus-
tries are usually susceptible to treatment in a POTW. In
other words, for the first fifteen industrial categories,
there is no specific numerical pretreatment requirement at
the Federal level. However, there are general prohibitions
provided in the pretreatment standards contained in Appendix 1,
On the other hand, the pretreatment standards promul-
gated for new sources in various industrial categories
generally contain limitations on the level of specific
pollutants allowable in the wastewater discharged to POTW's.
The nature of the pretreatment standards to be established
for the remaining major industrial categories is unknown at
this time. When issued, the information in these remaining
standards will be useful to local governments in determining
exact pretreatment requirements for the industries in question,
For new sources, pretreatment standards have been estab-
lished for a number of major industries and have been pub-
lished in the Federal Register.
Planning Agencies & Pretreatment Responsibility
Section 208(b)(2)(C)(iii) provides for:
The establishment of a regulatory program to assure
that any industrial or commercial wastes discharged into any
treatment works in such areas meet applicable pretreatment
requirements.
Accordingly, a Water Quality Management Planning (208)
Agency will play a major role in ensuring that all indus-
trial wastes discharged into POTW's comply with Federal
pretreatment standards promulgated under Section 307 of the
Act. Additionally, such a planning agency will assist
municipalities in establishing pretreatment programs.
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in many cases as a result of water quality requirements
or other factors specific to a plant or its NPDES permit, it
will be necessary for the municipality to establish pretreat-
ment requirements more stringent than the Federal_standards.
The planning agency will assist the municipality in developing
these pretreatment requirements and ensuring their compliance.
Industrial users will be required to meet both Federal
and applicable State and local pretreatment requirements.
These requirements will be evaluated within the Water Quality
Management process in order to ensure that effluent limit-
ations for the POTW designated in its NPDES permit can be
met. Similarly, facilities plans will be reviewed and
pretreatment will be an issue in these reviews. In practice,
(208) planning agencies will work closely with municipal-
ities, giving expert advice on how to write pretreatment
requirements for inclusion into the municipal ordinance.
Effluent Limitations for POTW's
As a result of the fundamental changes instituted by
Public Law 92-500, POTW's are now required to obtain permits
for their discharges and to meet certain minimum effluent
standards. Both POTW permits and effluent standards have a
direct bearing on the control of industrial pollutants that
must be undertaken within a particular system.
Since most POTW's discharge their effluents to navigable
waters, the Act requires that effluent limiting regulations
be promulgated. As indicated, EPA has published in the
Federal Register rules and regulations governing POTW dis-
charges entitled "Secondary Treatment Information," (Appen-
dix 2). These regulations set forth specific concentration
limits to be achieved by secondary wastewater treatment
facilities. Limits are placed on permissible discharge
concentrations (or removal efficiencies) for BOD, suspended
solids, and fecal coliform bacteria. Additionally, an
acceptable pH range for secondary POTW effluents is set.
The pollutants limited in the regulation are generally
susceptible to treatment in POTW's. As a consequence, indus-
trial pollutants only become important with regard to second-
ary treatment standards when the contribution causes these
pollutant discharge limitations to be exceeded.
In many instances, State or local water quality stand-
ards require a degree of treatment greater than that re-
quired to meet the secondary treatment regulations, such
as more stringent BOD or suspended solids requirements.
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Additionally, water quality standards often exist for pollu-
tants other than those regulated in the secondary treatment
standards, such as phosphorous, nitrogen compounds, metals,
etc. Treatment requirements necessary to meet water quality
standards are normally incorporated into the NPDES permit.
Consequently, control of applicable industrial pollutants
can be extremely important in helping the municipality meet
its NPDES permit requirements.
Procedures developed under Section 402 of the Act pro-
vide details for implementation of the NPDES permit program.
Under the program, all point sources, including POTW's,
must obtain a permit to discharge to navigable waters of the
United States. NPDES permits are not required for indus-
trial sources contributing to POTW's, but many limitations
placed on a POTW, beyond standard secondary treatment, are
aimed at controlling the effects of non-domestic waste-
waters.
The NPDES permit has several impacts on State or local
pretreatment policy. First, as a part of the permit
application, the permittee must obtain preliminary infor-
mation on the activities and wastewater characteristics of
major industrial contributors within the collection system.
Based on this information, effluent limitations for pollu-
tants not susceptible to treatment in a POTW may be indivi-
dually established by the permitting agency.
Secondly, under the Federal NPDES permit regulations
(40CFR126) the permitee is required to provide notice to
the Regional Administrator of the following:
(i) Any new introduction of pollutants into such treat-
ment works from a source which would be a new source as
defined in Section 306 of the Act if such source were dis-
charging pollutants;
(ii) Any new introduction of pollutants which exceeds
10,000 gallons on any one day into such treatment works from
a source which would be subject to Section 301 of the Act
if such source were discharging pollutants; and
(iii) Any substantial change in volume or character
of pollutants being introduced into such treatment works by
a source introducing pollutants into such works at the time
of issuance of the permit.
This notice must include information on the quantity
and quality of wastewater introduced by the new source into
the publicly owned treatment works, and any anticipated
impact on the effluent discharged from such works.
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In addition to effluent limitations, the permit sets
forth special conditions that pertain to pretreatment activi-
ties. Municipalities are considered the first line of
defense for Federal pretreatment programs. For this reason,
they are encouraged to enact an ordinance giving them the
power to enforce Federal pretreatment standards as well as
State and local standards "not in conflict" with Federal
pretreatment standards. Areawide planning agencies will
also play an important role in both ordinance development
by municipalities as well as ensuring that pretreatment
requirements accomplish the goals of the Act. In an effici-
ent POTW system, a properly designed ordinance acts as the
impetus for a responsible approach to control and pretreat-
ment of industrial pollutants. Guidance is provided in this
document to aid in the development of a municipal ordinance
for industrial use of publicly owned sewers.
Organization of Guidelines
These guidelines are presented in three volumes. Volume
I contains the main body of the guidelines, .and Volumes II
and III contain appendices furnishing the backup data to
various sections of the document. Volume III is devoted to
Appendix 8, containing pretreatment information for major
industrial source categories compiled from published and un-
published Effluent Limitation Guidelines Development Documents,
The main body of the guidelines is composed of six major
sections. The first four sections provide the essential
information necessary to establish and administer an
industrial pollutant control program. Specific aspects dis-
cussed include organization, financial considerations,
policy and public relations in Section B, legal aspects
in Section C and monitoring in Section D. The legal
aspects consist primarily of considerations related to an
ordinance for industrial use of publicly owned sewerage
facilities. A recommended ordinance is contained in
Section C of the first volume.
One of the prime considerations in the development of
a workable ordinance is the establishment of limitations for
specific pollutants contained in industrial discharges to
publicly owned sewexage systems. Administrative considera-
tions for setting such limits are discussed in Section C.
The technical information necessary to establish limits in
a particular system is contained in Sections E and F of
Volume I, Appendices 5 and 6 of Volume II, and Appendix 8
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of Volume III. Section E and Appendix 5 present technical
data on the interference and inhibition characteristics of
pollutants contained in industrial discharges. The data
presented includes information on major organic and inorganic
constituents, explosive and corrosive wastes and excessive
discharges. Section F and Appendix 6 provide the results
of a survey to determine the removal or pass through charac-
teristics of various pollutants in POTW's. Appendix 8 is a
compilation of information on major industries, with
emphasis on the typical wastewater characteristics of plants
within the subcategories established for each industry-
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SECTION B
MANAGEMENT OF A CONTROL PROGRAM
Purpose
Organizational Structure
Large Systems
Administrative
Industrial Waste Division
Field Monitoring
Laboratory
Legal-Enforcement
Medium Size Systems
Small Systems
Financial Aspects
Policy
Pretreatment
Joint Treatment
Sludge Disposal
Summary
Public Relations
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SECTION B
MANAGEMENT OF A CONTROL PROGRAM
Purpose
The objective of an industrial pollutant control program
is to assure continuity of treatment, provide physical pro-
tection of treatment facilities, and prevent the discharge
of pollutants from the treatment facilities which would be in
violation of NPDES permit conditions and other regulatory
requirements. In order to achieve these objectives, POTW
operators must develop programs which provide a data base
for establishing local requirements and which after the
requirements have been established, form a framework for
administering these requirements. The purpose of this sec-
tion is to discuss various aspects relating to the management
of an industrial pollutant control program.
The scope of such a program depends to a large degree
on a number of factors. Of prime importance is the size
of the sewerage system and the number and type of industries
utilizing the system. Other significant elements include
the type of treatment facility, the water quality standards
applicable to the POTW and the provisions of the plant's
NPDES permit.
In this section, management approaches are discussed
on three levels, for large, medium, and small systems, referring
in general to systems with average dry weather flows in excess
of 100 mgd, between 10 and 100 mgd, and less than 10 mgd.
However, a system with a heavy industrial contribution, but
an average flow of under 10 mgd may opt for a more extensive
program, whereas a system with an average flow in excess of
10 mgd but only limited industrial contribution may adopt a
less comprehensive program. Thus the categorization by size
is provided as a general guideline only, and should be con-
sidered flexible depending upon the needs of a particular system.
In the case of small and intermediate size systems, the 208
areawide planning agency can provide valuable assistance to
a POTW in development of a viable control program. The degree
of industrialization in a community and the type of industrial
facilities contributing to the system, are major factors in
determining the requirements of an industrial pollutant control
program for a given POTW.
Historically, municipalities and authorities that have
developed effective programs to control industrial pollutants
have generally been motivated by several factors. The most
effective industrial pollutant control programs have generally
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been instituted where the need to protect treatment facil
ities, plant operation or receiving waters has been apparent.
in those cases, the motivating force toward a control program
was either frequent or serious plant upsets or the require-
ment of meeting stringent water quality standards. Also,
many POTW's have established industrial programs primarily
as a revenue producing mechanism through the use of user
charges. User charges have been applied not only to
flow and organic loading, but in many instances user charges
have been imposed upon incompatible pollutants as well.
For many POTW s interest in controlling non-residential
contributions to their system is an outgrowth of the require-
ments of Public Law 92-500 and the subsequent receipt of an
NPDES permit. The permit generally places limitations on
the quality of discharge permissible by the POTW. As a
result, it is important that interferences that might decrease
the treatment plant's operating efficiency, or pollutants
that might pass through a system be avoided. In addition,
the permit may require that an enforceable ordinance be
enacted. Municipalities are encouraged by the EPA to adopt
local ordinances to control pollutants which might upset the
POTW, decrease treatment efficiency, or cause a violation of
the effluent limitations in the NPDES permit. Consequently,
an effective program is essential not only to control pollu-
tants entering the treatment plant which in turn affect its
effluent, but also to develop and enforce an appropriate
ordinance for the control of industrial pollutants.
Beyond fulfilling the specific requirements of the NPDES
permit, a properly administered industrial pollutant control
program also serves several other essential functions. Depend-
ing on the degree to which the POTW is cognizant of non-
residential contributions to its system, the control program
can serve as a basis for obtaining data on industrial contri-
butors and in turn identify potential problem areas. The
program should offer an ordered mechanism through which
information can be transfered on the degree of compliance
with ordinance requirements and Federal regulations. Above
all, the control program provides the mechanism and enforce-
ment tools necessary to assure treatment continuity and the
protection of public facilities.
Additionally, industrial pollutant control programs
may be used to establish procedures for implementing sur-
charge or user charge policies. The EPA Construction
Grant Regulations (40 CFR 35) require construction grant
applicants for funds authorized under Title II of PL-92-500
to establish and maintain a proportionate system of user
B-2
-------
charges for operation and maintenance costs and industrial
cost recovery for capital costs. These requirements can be
most effectively implemented through an industrial pollu-
tant control program.
The inclusion of references to user charges and indus-
trial cost recovery in this document is not intended as a
guide for implementation of any specific cost recovery
technique. However, in most POTW systems, there is a close
tie between control of industrial pollutants and user charge
administration. This results from the fact that both sub-
jects relate to the same contributors to the sewer system.
Consequently, reference to user charges is merely a recogni-
tion of mutual concern over cost recovery and pollutant con-
trol by POTW personnel responsible for the management of
industrial pollutant control programs.
Organizational Structure
The industrial pollutant control program consists of
the activities and personnel assigned specific functions
and responsibilities in relation to the control of industrial
pollutants. For most larger systems, this involves a well-
defined organizational structure with assigned personnel
having specialized training and qualifications. For smaller
systems, it may involve only a part time assignment for a
single individual. However, even small systems should be
aware of the functional steps involved in an industrial
pollutant control program and provide for these functions
on an appropriate scale.
Figure B-l illustrates a conceptual organizational
structure based on the functions required for a workable
control program. The manner in which these elements are
organized can vary greatly depending on the local situation.
The essential aspect is the need for an efficient information
transfer mechanism. The typical organization shown outlines
the interrelationship of the essential elements of a program.
Generally, the larger the system,the more complex the
organization. Individual responsibilities also become more
clearly defined as the system increases in size. For very
small systems, outside experts are frequently utilized to
provide engineering, legal and laboratory expertise. In
order to supply the most meaningful guidance, the organization
necessary for an effective industrial pollutant control pro-
gram is specifically discussed in the following paragraphs in
terms of small, medium and large systems.
B-3
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MUNICIPAL
GOVERNMENT
OR
REGIONAL BOARD
STATE&
FEDERAL
REGULATORY
AGENCIES
POTW
ADMINISTRATION
PUBLIC
RELATIONS
LEGAL-
ENFORCEMENT
COLLECTION &
TREATMENT
SYSTEM
OPERATION
-i
INDUSTRIAL
WASTE
DIVISION
LABORATORY
FIELD
MONITORING
CONCEPTUAL ORGANIZATION OF AN
INDUSTRIAL WASTEWATER CONTROL PROGRAM
FIGURE B-l
B-4
-------
Large Systems
Figure B-2 presents an example of an industrial waste
control program organization for a large POTW system. The
chart illustrates the need for a structured organization to
most effectively administer a control program in a large
system. The larger and more complex the POTW, the more
highly developed and structured the organization should be.
Nevertheless the components of an effective organization
demonstrated by the chart are essential for a functional
industrial waste control program in any large system.
Specific sections of an industrial waste control organization
for a large system should include the following:
B-5
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MUNICIPAL GOVERNMENT
OR
BOARD OF COMMISSIONERS
DIRECTOR OF
POLLUTION CONTROL
TREATMENT PLANT
OPERATION & MAINTENANCE
INDUSTRIAL WASTE
DIVISION
OPERATIONS SECTION
UAdministers permit program
a.Reviews applications
b. Issues permits
c.Maintains permit files
2£valuates pretreatment practices
a.Reviews plans and specifications
b.Checks operation of facilities
3,Coordinates enforcement activities
a.Analyzes self-monitoring and compliance
monitoring data
b.Conducts conciliation meetings
.c,Provides technical expertise in court actions
4.Formulates industrial wastewater policy
a.Evaluates Federal and State standards
b.Recommends specific policy action
5.Administers user charge and
industrial cost recovery programs
SEWER SYSTEM
OPERATION &
MAINTENANCE
LABORATORY}- -\
J
MONITORING SECTION
I,Develops industrial wastewoter data base
a. Reviews applicable records and files
b.Checks industrial plant in field
2,Conducts on-site monitoring and inspection
a,Scheduled monitoring for compliance,
usercharge,industrial cost recovery and EPA
reports
(l)Composife sample with flow measurement
over several days
(2)0nce per year for all major industries if
possible -
b. Da-scheduled surveillance for compliance
(I) Composite or grab sample with or without
flow measurement as often as possible
c.Demand monitoring as required
RESEARCH &
DEVELOPMENT
TYPICAL ORGANIZATION OF A LARGE SYSTEM
FIGURE B-2
-------
Administrative
Administrative responsibility for the program should
rest with a single person who has intimate knowledge of all
aspects of pollution control and wastewater treatment within
the jurisdictional boundaries. In municipal systems, usually
the Director of Public Works or Superintendent of Sanitation
would be the appropriate individual. In regional authorities,
there is most often a Board of Commissioners which has
overall responsibility for the entire POTW system. Commissioners
are generally appointed by appropriate governmental officials
such as the governor of the state, and frequently act only in
an overall policy and management capacity. In this sense,
such boards can be considered as analogous to the mayor
and council in a municipality. Day-to-day operations are
usually administered by an Executive Director, General Manager,
Chief Engineer or Superintendent who can be compared for
these purposes to the Commissioner of Public Works in
municipal operations.
Decisions pertinent to pretreatment policy should
be made by this individual drawing upon information supplied
by key subordinates. These subordinates should include
personnel such as the Chief Industrial Waste Engineer, Chief
Plant Operator, Chief Chemist, and other specialists concerned
with the control program, including field investigators,
engineers and attorneys.
Specific functions of the administrative section
should include (1) basic policy decisions (2) management of
budgetary needs (3) personnel administration and (4) coordin-
ation with the public and appropriate municipal, State and
Federal authorities.
Industrial Waste Division
The individuals comprising the industrial waste
division represent the heart of any industrial waste control
program. Generally the division is comprised of engineers
that conduct the program and secretarial personnel, field
inspectors and laboratory technicians that provide the neces-
sary support for effective operation. The engineering staff
engaged in this activity should be the most knowledgeable
group of individuals on all aspects of industrial wastewater
within a given system. They should be thoroughly familiar
with the operation and wastewater produced by industries in
the system, pretreatment facilities utilized by the industries,
applicable provisions of Federal and State standards and local
ordinances and characteristics of the treatment processes
B-7
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utilized in the system. If a local permit program is employed,
the industrial waste division would undoubtedly administer
its operation. Generally this group will formulate industrial
wastewater policy and recommend specific policies to the
administrator for implementation. The industrial waste division
would also generally coordinate enforcement activities and
provide necessary technical expertise to the legal staff in
court actions.
Staff levels vary considerably depending upon size,
fiscal resources, organizational structure, number and type
of industries present and the specific NPDES permit require-
ments of the system. The largest POTW systems in the country
have as many as 50 to 80 individuals reporting to the Chief
Industrial Waste Engineer. Smaller cities and regional
authorities obviously require smaller staffs, with the level
generally varying from approximately 1/2 to 2 individuals per
10 MGD, depending upon the factors indicated above.
Field Monitoring
The organization should include a group of inspectors
whose only responsibility is the monitoring of non-residential
contributors. These field investigations should include
initial plant surveys, data acquisition at the plant site,
and all follow-up monitoring and inspection activities. Moni-
toring and the general conduct of field investigations is an
important subject which is covered in detail in Section D
of these guidelines.
The field monitoring section should have total
responsibility for surveillance of non-residential sources.
Specific functions to be carried out by field inspectors
include: (1) sampling and flow measurement at wastewater
sources, (2) inspection of plant and pretreatment operations
at the time of sampling, (3) maintenance of specialized
field equipment, and (4) performance of specialized monitoring
activities in connection with locating the source of problems
within the system, enforcement activities, etc. The Metro-
politan Sanitary District of Greater Chicago provides uniforms
and badges for its inspectors to formalize their status in the
community. This can be helpful in gaining quick access to
industrial facilities when necessary- In any event, all
field inspectors should be provided with proper credentials
which should be carried for identification at all times.
B-8
-------
Laboratory
An industrial pollutant control program will gen-
erally require some expansion of the typical laboratory
required for control of biological treatment processes. As
a result, additional personnel may be necessary to carry out
analyses in conjunction with a monitoring program. Frequently,
these technicians are incorporated into the existing laboratory
organization, so that coordination with the industrial waste
division is essential. Some POTWs are structured so that
laboratory personnel engaged in industrial wastewater analysis
report directly to the Chief Industrial Waste Engineer.
Such an arrangement may be preferable for improved communica-
tions and delineation of responsibility.
Where this function is part of the overall labora-
tory responsibility, then data must be reported to the indus-
trial waste division so that pretreatment performance can be
evaluated. If any ordinance violations are suscepted, then
analytical data would also be passed on to the legal staff
for evaluation and possible enforcement action. The specific
functions of the laboratory in connection with industrial
wastewaters include (1) analysis of field samples, (2) main-
tenance of laboratory equipment and (3) proper record keeping
and reporting in support of industrial waste division activities,
Legal - Enforcement
One or more attorneys may be required to provide
legal services with regard to enforcement of ordinance regu-
lations. Attorneys may not have full time responsibility
in connection with ordinance enforcement. Instead the legal
staff may serve the dual function of supporting legal action
against ordinance violators, and general legal support of
other activities in the water pollution control area.
For enforcement activity, the legal group should
receive information directly from the industrial waste
division staff, as well as from field monitoring and labora-
tory personnel. The special functions of enforcement include
(1) assistance in evaluation of suspected ordinance violations,
(2). notification of suspected violators, (3) participation in
follow-up meetings with violators (4) preparation of briefs
for litigation; and (5) court action.
Medium Size Systems
As the size of a POTW decreases, the operation of the
industrial pollutant control program becomes less of a separate
entity, and more entwined in the overall operation of the
B-9
-------
wastewater collection and treatment facility. Because of
limited resources, administrative and laboratory personnel
generally become responsible for both plant operations and
control of pollutants contributed by non-residential sources.
Figure B-3 provides a typical organization chart for a
medium size POTW system.
Although fewer individuals are involved, the specific
organizational elements of a control program must be main-
tained. The organization will not be as structured as in
large systems, but the essential functions of industrial
waste control must be performed in conjunction with other
duties. Among these functions is the use of a field moni-
toring group to carry out plant inspections and effluent
sampling. The field crew is essential for all of the
specific monitoring requirements necessary to control
industrial contributors to the system. Likewise, other
specific functions of a control program would have to be
maintained in a medium size system, such as ordinance
enforcement, summary and analysis of industrial data and
user charge administration. However, unlike the large system
organization where individuals or groups of individuals
have well defined task assignments, the control program for a
medium size system will most likely contain individuals
with multiple functions and responsibilities. Some medium
size systems with many industrial contributors may find
it necessary to have an industrial waste engineer or other
individual specifically assigned to the control of discharges
from these facilities.
Small Systems
A large proportion of municipal POTWs that treat non-
residential wastes fall into the small system category. In
a small system, adequate resources would generally not be
available to have any individual whose sole responsibility
lies in the area of non-domestic pollutant control. Instead,
all of the elements of an industrial pollutant control pro-
gram that are delineated for large systems would have to
be handled by personnel currently employed by the municipality.
This is not unrealistic, since quite often a small system
would be concerned with only a few, or even a single industrial
contributor.
Figure B-4 illustrates an organizational arrangement for
a typical small system. The structure shown is only one of
several that could be effectively utilized in a small
municipality. The variety encountered in the organization of
small local governments suggests that a number of different
B-10
-------
MUNICIPAL
ATTORNEY
r
l_
SEWER SYSTEM
OPERATION &
MAINTENANCE
I
MUNICIPAL
GOVERNMENT
COMMISSIONER
OF PUBLIC WORKS
j
DIRECTOR OF
POLLUTION
CONTROL
Overall responsibility
for industrial waste
CONSULTING
ENGINEER
IF REQUIRED
(Contract)
ASSISTANT DIRECTOR
OF POLLUTION CONTROL
Administers industrial
waste program
TREATMENT PLANT
OPERATION &
MAINTENANCE
I
LABORATORY
FIELD
MONITORING
Conducts field
monitoring of
industrial wastes
TYPICAL ORGANIZATION
OF A MEDIUM SIZE SYSTEM
FIGURE B-3
B-ll
-------
MUNICIPAL
ATTORNEY
(controct)
MUNICIPAL
GOVERNMENT
T
I
I
"1
COMMISSIONER
OF PUBLIC WORKS
Overall responsibility
for industrial waste
TREATMENT PLANT
& SEWER SYSTEM
OPERATION &
MAINTENANCE
TOWN AND/OR
CONSULTING
ENGINEER
IF REQUIRED
(contract)
Administers Industrial
waste program
PLANT LABORATORY
Conducts field
monitoring of
industrial wastes
CONTRACT LABORATORY
SERVICES FOR
SPECIALIZED ANALYSES
IF REQUIRED
TYPICAL ORGANIZATION OF A SMALL SYSTEM
FIGURE B-4
B-12
-------
arrangements may be equally effective in the administration of
an industrial pollutant control program. Nevertheless, in
the small system case, generally one person has responsibility
for monitoring and all specialized analysis is contracted to
commercial laboratories. Similarly, the Director of Public
Works would most likely have overall administrative respon-
sibility in addition to performing the functions of the
industrial waste engineer. A town engineer may be utilized
for industrial waste control, reporting either to the Director
of Public Works or directly to the governing body. The town
engineer may be a full time employee if the needs of the
system dictate, but he is most frequently a consulting
engineer under a retainer type contract to the municipality.
Specialized engineering requirements would usually be provided
by either the town engineer or another consultant, with
legal questions being handled by the municipal attorney. Since
the NPDES permit program for POTW's, large or small, encourage
implementation of Federal pretreatment standards, it is
recommended that industrial pollutant control be implemented,
even in the smallest of systems, where there are industrial
users.
Financial Aspects
As might be expected, the cost of an industrial pollutant
control program is a function of both the total system flow
and of the proportion of the industrial wastewater contribution,
A survey of municipal and regional sewerage systems with dry
weather flows ranging from 15 to over 1,000 mgd was conducted.
The survey showed that the annual direct cost of the industrial
pollutant control program was generally in the order of _$1LL000
to_$JL«_500 per million gallons per day of dry weather flow for
systems having some significant portion of the total wastewater
flow "from industrial contributors. On this basis, the direct
cost of a program covering industries for a system with an
average flow of 50 mgd might be $50,000 to $75,000 per year
(1975 dollars). Assuming an average salary level of $15,000
per year for personnel assigned to such a program, this system
would support a staff of 3 to 5 persons.
Many systems have traditionally recovered the additional
costs for treating and monitoring industrial wastewater,
through imposition of a user charge. These user charges have
generally been related to the additional cost of treating for
removal of suspended solids and BOD for industrial wastewaters
that exceed domestic sewage in these components. In addition,
PL 92-500 and the EPA construction grant regulations now
require Federal construction grant recipients to establish
and maintain a user charge program and a system of industrial
B-13
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cost recovery. The proportionate costs of an industrial
pollutant control program such as outlined above, could be
added to the user charge for the industrial contributors.
In this way, the cost of the industrial pollutant control
program would be distributed back to the contributor of the
industrial wastewater being controlled. The cost of the
control program could be recovered through a formula
similar to the user charge formula where flow, loading, and
a charge per connection or a charge per monitoring visit
are used to determine an equitable cost distribution.
It should be noted that a well run, efficient industrial
pollutant control program may be cost effective for both the
POTW and the industrial contributors to the system. In some
cases, the control program can pay for itself by means of
increased user charge revenue derived from the
identification and continued surveillance of industrial
discharges to the POTW. Industries in the system, may also
benefit from the cost savings in economy of scale realized in
cases where the municipality performs all of the monitoring
functions. In such instances, lower costs should result
from the use of a central laboratory and experienced monitor-
ing field personnel, than the industry would incur in admin-
istering its own monitoring program. In particular, small
industries with limited resources may prefer that the
municipality perform this function.
Policy
Pretreatment
Most States or municipalities will require pretreatment
in order to comply with the effluent limitations in the
NPDES permit. Pollutants which would interfere with or pass
through the POTW, resulting in a violation of any of these
NPDES permit requirements, must be pretreated or rejected
from the system. The following sections of the guidelines
contain technical information to assist the State or munici-
pality in determining specific pretreatment requirements.
Pretreatment may be necessary for compatible or incompatible
pollutants since both may be limited in the NPDES permit, and
since either can cause plant upsets. Generally, however, where
design capacity is available, except for shock loading pro-
visions, pretreatment would not be required for compatible
pollutants. Pretreatment is most commonly required for
incompatible pollutants to prevent interference with treatment
processes or pass through to receiving waters.
B-14
-------
Federal pretreatment standards for fifteen categories of
existing industrial sources have been promulgated (Appendix 1)
but these standards, in effect, require no pretreatment as
the wastewaters involved are generally susceptible to treat-
ment in POTW facilities. However, this does not preclude
local pretreatment requirements for compatible pollutants,
if necessary, in particular, where design capacity is not avail-
able, pretreatment for compatible pollutants may be necessary to
comply with NPDES permit effluent limitations. Pretreatment
regulations for the remaining major existing industrial cate-
gories are still pending, with specific standards anticipated
for most incompatible pollutants.
In addition to the regulatory aspects, pretreatment of
incompatible wastes offers several operational advantages to
POTW's. One significant advantage to the municipality is
the specialized treatment that each wastewater contribution
receives, and the fact that the potential for plant upset is
greatly reduced by pretreatment. Local control can also
serve as an insurance measure to protect against damage to
the POTW from industrial wastes. Finally, the problem of
incompatible pollutants contaminating the sludge from the
POTW is reduced, as discussed in the following section on
sludge disposal.
Joint Treatment
Joint treatment is a policy alternative that can be
advantageous to both the POTW and the industry with regard to
pollutants susceptible to treatment in POTW's. Generally,
the treatment of industrial wastewaters in a POTW is incidental
to its primary function of treating domestic sewage. Where
the industrial contribution constitutes a significant portion
of the total flow and substantially alters the concentration
of pollutants normally contained in domestic sewage, the
public agency may resort to the joint treatment approach.
In this approach, the industry or industries contributing
the pollutants is made a partner in the design and construction
of the system, and the treatment works are designed to
specifically remove the industrial pollutants. Both capital
costs and operating costs are allocated to the industry and
the public agency according to an agreement arrived at through
negotiation, or as required by Federal regulations if construction
grant funds are involved.
Joint treatment of industrial wastewaters with municipal
domestic sewage offers these advantages:
- Savings in capital and operating expenses due to
the economics of large-scale treatment facilities
B-15
-------
- Increased flow over separate treatment which can result
in reduced ratios of peak to average flows
- More efficient use of land resources, particularly
in cases where available land for treatment facilities
is scarce
- Improved operation (larger plants are potentially
better operated than smaller plants)
- Increased number of treatment modules with resultant
gains in reliability and flexibility
- More efficient disposal of sludges resulting from
treatment of wastewaters containing pollutants sus-
ceptible to treatment in POTWs
- Utilization of the nutrients available in domestic
wastes for biological treatment of industrial wastes
which are nutrient deficient
Possible disadvantages of joint treatment are as follows:
- Where the pollutants are different from those usually
treated in a POTW, design to treat the combined
industrial-domestic waste stream for these pollutants
may not be cost-effective (Reference F-25)
- Joint treatment by definition implies that the POTW
was designed so as not to be interfered with by indus-
trial wastes. However, where this requires design
modifications ordinarily not required for domestic
wastes, joint treatment may not be cost effective
- If joint treatment results in sludge disposal or
utilization problems it may not be acceptable
- Some costs for the construction of joint treatment works
solely to treat industrial pollutants are not eligible
for Federal construction grants
Sludge Disposal
The ultimate disposal of sludges produced by either pre-
treatment or joint treatment operations is an important factor
to consider. The POTW must be aware of the effect of its
policies on environmental problems that may result from sludge
disposal.
B-16
-------
Generally pretreatment facilities will remove incompatible
pollutants that may eventually be deposited in the sludge
produced by the operation of the publicly owned treatment
works. This can be a meaningful advantage in terms of the
environmental effects of the ultimate disposal of sludge from
the POTW. Incompatible pollutants in sludges can cause
problems in most disposal techniques utilized, including
incineration, landfills, ocean dumping and land spreading.
Consequently, the removal of incompatible pollutants at their
source by pretreatment is usually advantageous to the POTW
in terms of its sludge disposal.
Nevertheless, incompatible pollutants removed by pretreat-
ment also require an ultimate disposition, although the
impact on the POTW may have been eliminated. In some cases
the sludge produced by pretreatment operations may be pure
enough to warrant by-product recovery or recycle. When this
is not economically or technically feasible, disposal of
sludge is necessary. Although the sludges produced by
industrial pretreatment may not technically be under muni-
cipal regulatory control, the impact on other environmental
areas should be noted. A possible approach to this problem
would be an effort by the municipality to coordinate off-site
disposal with appropriate regulatory agencies. If on-site
disposal is utilized by the industry, attempts should be
made to evaluate proposed disposal schemes to prevent future
air and water pollution problems.
Summary
The treatment policy instituted by a POTW, whether
pretreatment or joint treatment, should be determined on the
basis of the conditions within the system. One of the most
important factors to consider is the potential effect of
the chosen course of action. The POTW must be aware of its
policy's effect on critical environmental problems such as
sludge disposal. As a result, the treatment policy should
be instituted on the basis of a broad overview of all aspects
and consequences of action taken.
Public Relations
It must be recognized that some industries using a
public sewerage system will be reluctant to provide the
necessary pretreatment facilities, particularly if they have
been using the public system for some time and the effects of
their contribution are not apparent. One way in which some
public agencies have been able to enlist the support of their
contributing industries is through the formation of an informal
coordinating committee, which would consist of representatives
B-17
-------
of the affected industries and the public agency. This
committee would explore all aspects of the Federal regulation,
including pretreatment requirements and the NPDES permit for
the POTW, and develop programs which would meet the require-
ment of the regulatory agencies. Such committees would be
purely advisory and would not have any legal status, but
could serve as a forum for the exchange of ideas.
B-18
-------
SECTION C
LEGAL ASPECTS OF A CONTROL PROGRAM
Introduction
Legal Authority
Sewer Use Ordinances
Historical Development
Types of Ordinances
Recommended Ordinance for Industrial Use of Publicly Owned
Sewerage Facilities
Introductory Sections
Regulatory Sections
Excessive Discharge Rate
Establishing Limitations for Pollutant Parameters
Other Regulatory Sections
Optional and Procedural Clauses
Recommended Ordinance
-------
SECTION C
LEGAL ASPECTS OF A CONTROL PROGRAM
Introduction
The legal considerations inherent in the development and
administration of an industrial pollutant control program are
perhaps the most significant factor in the establishment of a
viable program. The legal aspects are particularly important
in instituting a control program in terms of providing the
legal authority over industrial discharges to the sewerage
system. In many cases, legal authority may be complicated by
the structure of a sewer district or regional sewer authority.
Many districts and regional authorities act essentially as
wholesalers serving a number of political subdivisions, and
do not have any direct contact with industries in the system.
However, where the service area coincides with political
boundaries, then legal authority can usually be established
in a relatively simple manner, by the promulgation of an
ordinance for the control of industrial use of publicly owned
sewerage facilities.
The ordinance is the heart of any industrial pollutant
control program, providing the essential mechanism for con-
trolling the discharge from industries within the POTW system.
Consequently, the ordinance must be carefully drawn to include
all essential ingredients for the particular system. Once
promulgated, the ordinance should be utilized for the control
of all industrial wastewater discharges and the eventual
enforcement of its terms against all violators. Therefore,
the administration or enforcement of the ordinance is equally
as important as its contents. Enforcement must be an integral
part of any industrial pollutant control program. Consequently,
legal assistance must be viewed as a continuing need which does
not end once the ordinance is drawn and instituted. Proper
enforcement requires teamwork between administrators, engineers,
attorneys and field and laboratory personnel, with the legal
role being the key to eventual resolution of problems through
conciliation or court action.
Legal Authority
One of the most significant factors in the establishment
of a viable industrial pollutant control program is the provision
of adequate legal authority to develop, administer and enforce
the program. Whatever agency is designated to operate the
program must have sufficient power to enforce its rules and
regulations on industrial users and to obtain the data necessary
to monitor how its rules are being complied with.
C-l
-------
If the service area of a public sewerage agency coincides
with the boundaries of a political subdivision (city, county,
etc.) the legal problems are usually relatively simple.
However, if the sewerage agency serves more than one political
jurisdiction, and particularly if it serves them essentially
as a wholesaler, the problems can become more complicated.
The solution depends to some extent on the legal structure
of the sewerage agency- If it is only a voluntary association
of independent municipalities, the agency will generally only
have such authority as has been delegated to it by the compact
creating the sewerage authority or district. If the sewerage
agency has been established by a superior governmental
jurisdiction, it then may be able to superimpose its authority
on that of the local municipalities.
In any case, many existing regional sewerage authorities
or districts are not able to legally interface with industries
in the system because the industries discharge to municipal
sewers which in turn connect to the regional agency. In
such instances, the development and enforcement of ordinances
controlling the discharge of industrial wastewaters is
legally the responsibility of the individual municipalities
in the system. They may look toward the regional agency for
guidance in such matters, but nevertheless the municipalities
in these cases would retain the legal authority to deal with
industries in their systems in these situations.
With the advent of the NPDES permit program, it becomes
increasingly important for the permittee to have the right to
directly control the wastewaters from all contributors within
the sewerage system. If an industrial discharger causes an
upset in treatment plant operations and a resulting violation
of the permit provisions, the POTW must have the right to
directly and immediately control the industrial discharge.
Regional agencies with the most effective industrial pollutant
control programs at present have obtained the legal authority
to control industries in their system directly. In some
instances it was necessary to have the state legislature
revise the compact or charter of the regional agency in order
to obtain this authority. In other instances, renegotiation
of the agreement between the regional agency and the munici-
palities in the service area might be the most direct method
for obtaining legal authority. in particular, the 208 planning
agency can provide assistance in obtaining legal authority.
In. any case, to comply with NPDES permit requirements, it is
essential that the operating agency of the POTW obtain the
power to deal directly with the industries contributing to
its system in order to establish a viable industrial pollutant
C-2
-------
control program. POTW1 s faced with the problem of obtaining
legal authority, should have their legal counsel examine all
aspects of their charter or compact to determine the most
direct method for acquiring such authority.
Sewer Use Ordinances
The following describes the content of sewer use
ordinances, factors that control the content, the historical
development of such ordinances, types of ordinances, and the
application of sewer use ordinances to industrial users of
publicly owned sewerage facilities.
Historical Development
The content of sewer use ordinances has evolved over
the years roughly paralleling the increased sophistication
in wastewater treatment facilities. Early ordinances were
outgrowths of local plumbing and health codes, the contents
of which were primarily devoted to standardization of mate-
rials used in the construction of sewers and connections
thereto. Since sewage treatment was limited to settling of
solid material, the content of ordinances at this stage
focused on protection of sewers from clogging, corrosion
and explosive hazards. Most ordinances are built around
these basic provisions and have increased in scope as new
needs have arisen.
With the advent of secondary treatment processes and
the development of anaerobic digestion, closer control over
certain dissolved organic and inorganic pollutants became
necessary to prevent inhibitory effects in these units. In
many instances, this type of control was provided by setting
concentration limits for the acceptable discharge of critical
pollutants.
The recent application of State and Federal water quality
standards, which in many cases require the removal of even
trace quantities of certain toxic pollutants, has caused many
POTW1s to establish direct control over significant industrial
users. To gain information and control over these sources,
many ordinances are now including permit provisions and self-
monitoring provisions, or both.
Finally, as the costs of providing increased levels of
treatment have risen, many POTW's have been forced to expand
their revenue base. This has taken the form of a user
charge provision for contributors whose wastes have greater
strength than normal domestic sewage.
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There is no single ordinance now in force that could be
considered typical of all, or even most, ordinances currently
being utilized. Effective control of sewer use has been
obtained by both simple and complex ordinance structures.
Types of Ordinances
Two factors influence the size and content of a sewer
use ordinance. The first of these is whether the ordinance
is designed to be self-contained, or whether it simply states
general provisions and relies on separately published rules
and regulations for interpretation and implementation. The
second factor is whether or not the ordinance incorporates a
permit system for either industrial users or all users of
the system. Obviously, an ordinance which is self-contained
will be a longer document than one which is not. Permit
systems, if used, will also add length. Generally, smaller
communities with relatively few industries will use a self-
contained ordinance and will not employ a permit system.
Enforcement of the ordinance for the few industrial users in
such cases can be achieved on the basis of personal contact
between the pollution control officer and the industry plant
manager. As the size of the POTW increases or, more impor-
tantly, as the number of industrial users increases, it
becomes more difficult to provide flexibility for the numerous
individual differences between users within the ordinance
document itself. In these systems, a shorter document stating
general provisions may be more effective. This type of
ordinance is usually supplemented by a separate set of rules
and regulations that explain the responsibilities of users
with respect to the general provisions. The supplemental
regulations may take the form of a permit system with or
without industrial self-monitoring provisions. Permit and
self-monitoring requirements are particularly useful for POTW's
which are starting a comprehensive industrial discharge con-
trol program to meet NPDES requirements, and have to comply
with a schedule for the development of information on
industrial users. By using these provisions, the enforce-
ment authority can expand the coverage of a smaller initial
staff. In subsequent years, as both field and laboratory
capability is increased, more direct methods of compliance
monitoring can be used. In a fully developed industrial waste
control program, compliance monitoring is usually the most
effective tool for enforcement of the ordinance.
Regardless of the type of ordinance employed, its scope
and complexity should be limited to the resources available
to the enforcement authority. If enforcement of the ordinance
relies heavily on a permit system and self-monitoring, then
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there should be an adequate office and field staff to issue
and review permits and to check the periodic self-monitoring
information. If enforcement is based on analysis of samples
taken by the authority, then an adequate field and laboratory
capability is necessary. In all cases, sufficient manpower
should be available to follow up violations through the
administrative procedures provided in the ordinance. Only
by following up on each violation to gain compliance, will
credibility for both the ordinance and the enforcement
authority be established.
Recommended Ordinance for Industrial Use of Publicly Owned
Sewerage Facilities
The recommended ordinance contained herein covers
those portions of a complete sewer use ordinance which relate
only to the industrial use of sewer systems. Excluded from
the recommended ordinance are those parts of a typical ordi-
nance which relate to standards for construction of sewers
and appurtenances, provisions relating to the control of
infiltration and inflow, user charges and other miscel-
laneous provisions. These portions of a typical sewer use
ordinance are adequately covered in other reference sources.
The recommended ordinance is designed to be self-
contained, and in its full form could be used independently
as a separate document to control the industrial use of
sewerage facilities. In addition, individual sections of
the recommended ordinance may be used separately as an
addendum or a major revision to an existing ordinance.
Finally, individual clauses contained in the recommended
ordinance may be used to supplement an otherwise complete
document.
The recommended ordinance contains ten sections which
can be grouped into four basic parts as follows:
A. Introductory sections consisting of the introduction,
purpose, legislative background and definitions.
B. The body of the regulation consisting of prohibitions
and limitations on discharges, control of prohibited wastes,
sampling and analysis of wastes and enforcement procedures.
C. Optional add-on sections for a local permit program
if desired.
D. Procedural clauses.
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Introductory Section
The introductory section is simply a short statement of
the content of the ordinance. It usually includes the
precise location (city, county, State) of the area under
jurisdiction of the ordinance. This is left blank in the
recommended ordinance and, as well as all other blank spaces
in the ordinance, must be completed to suit the enforcement
agency responsible for implementation.
All ordinances contain a section on definition of terms
used in the body of the ordinance. As few as 10, and as
many as 50 definitions have been used depending on the
sophistication of the ordinance. The recommended document
contains an average length definition section. If a POTW
has other sewer ordinances, then the definitions should be
changed to be compatible with existing terminology. Many
ordinances also have an entry for "other terms" which refers
to the "Glossary-Water and Sewage Control Engineering"
published by the Water Pollution Control Federation.
Regulatory Sections
This portion of the ordinance contains the essential
regulations controlling discharges to sewerage systems, pro-
visions for sampling and analysis, and procedures for enforce-
ment of the ordinance.
Most ordinances cover prohibitions and limitations of
wastewater discharges in two parts; general prohibitions on
materials which have proven to be hazardous, or interfere
with both collection and treatment systems, and limitations
on certain critical pollutants which either interfere with
or pass through the treatment facilities. The general pro-
hibitions should delineate all objectionable materials as
specifically as possible, and also should provide legal
coverage for unanticipated problems. In this context, it
should provide the POTW with the flexibility to effectively
act against violators discharging materials not specifically
named in the ordinance.
Excessive Discharge Rate
One instance in which flexibility is essential is in
regard to excessive discharge rate. The recommended ordinance
includes, in Section 2, Paragraph (a) (7) a general prohi-
bition of wastes containing high concentrations of suspended
solids, BOD or COD, or unusually high flows which would
cause a treatment process upset and subsequent loss of
treatment efficiency. This clause is of particular importance
to many POTW systems. In a number of instances, industrial
dischargers constitute a large percentage of the flow to a
POTW. Excessive discharge can be extremely damaging in such
C-6
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cases. In addition, frequently industries with wide seasonal
variations in their wastewater characteristics discharge to
POTW's. Excessive discharge can also be a significant
problem with industries having such seasonal variations in
their plant effluent. In any case, it may be possible for a
POTW to define excessive discharge more specifically for the
system in question. This may be done in terms of design
capacity, NPDES permit conditions, or by taking into account
the most cost effective means of dealing with excessive
discharge. If it is possible to delineate specific limits
for excessive discharge incorporating local conditions, that
is generally more desirable than the general clause con-
tained in the recommended ordinance.
Establishing Limitations for Pollutant Parameters
The provisions for limitations on wastewater discharges
have been shown in both general and specific terms in the
recommended ordinance. Whichever option is utilized, the
NPDES permit conditions and Federal pretreatment standards
should be either referenced directly or used in the develop-
ment of specific numerical limitations for applicable pol-
lutant parameters. The general limitations provide flexi-
bility for systems which are unable to determine what specific
limitations to establish.
If sufficient information is available to select pollutant
parameters and set specific numerical limitations, that
option is usually preferable. However, it requires thorough
knowledge of the sewerage system, data on industrial con-
tributors, and familiarity with applicable water quality
standards, Federal pretreatment standards and the provisions
of the NPDES permit for the POTW. In establishing specific
limits, there are three major factors to consider; (1) Federal
pretreatment standards, (2) pass through of pollutants which
would affect the POTW's NPDES permit or water quality
standards and (3) inhibition of treatment processes or
interference with sludge handling or disposal operations.
The following paragraphs detail methods of determining
concentration based pretreatment requirements. It should be
noted, however, that the utilization of concentration pre-
treatment requirements in these guidelines is strictly an
example. Pretreatment standards expressed as mass or con-
centration are being evaluated by EPA. Federal pretreatment
standards may ultimately be based on one or both.
Federal Pretreatment Requirements
Federal pretreatment standards for new and existing
sources within major industrial categories are in various
states of development as described in other sections of
these guidelines. When finalized, the limitations prescribed
therein should be incorporated into the ordinance for all
affected industries. As a result, specific numerical limi-
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tations for various incompatible pollutant parameters will
be established for a number of major industries. Standards
applicable to industries within a given system should be
incorporated directly into this section of the ordinance.
An efficient way in which this may be accomplished is by use
of the Standard Industrial Category (SIC) code for each
industry established by the Office of Management and Budget.
The SIC numbers are utilized by the EPA in pretreatment
rules and regulations, and thus provide a convenient method
of cross-referencing for a given industrial category.
Pollutant Pass-Through
The second major consideration in setting specific
limitations is the pass through of pollutants which would
cause the POTW to violate its permit conditions or water
quality standards. The method required to establish limits
for industrial contributors based on permit or water quality
provisions is "back-calculating," using the allowable dis-
charge level in the standard as a starting point. This
procedure requires knowledge of the removal capability of
the treatment plant for the pollutant parameters of interest,
in addition to information on dilution and background levels
in the system. Frequently it is necessary to sample the
influent and effluent of the treatment plant to establish
its removal capability for a specific pollutant. If* data
for the system in question is not available, the removal
information contained in Section F and Appendix 6 may be
utilized to obtain average values for use in calculating
specific pollutant limitations. Those portions of the
document present the results of a survey of 269 treatment
plants to determine the removal capability of treatment
processes in regard to various pollutant parameters.
One major POTW system has developed a formula for use
in establishing limits on its industrial contributors based
on allowable pollutant concentrations in the treatment plant
discharge set by the State.
There are at least two other approaches including
economic equity between direct and indirect dischargers, and
equity of pollutant loading to the stream. The following
approach is exemplary only; no one approach is advocated by
EPA. The formula in the exemplary approach is as follows:
L = PR ^ Lf - La (1 - S)
where:
La = Average yearly influent concentration to the
treatment plant (mg/1)
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L = Maximum allowable concentration in an industrial
wastewater discharge (mg/1) .
Le = Allowable effluent concentration at the treatment
plant (mg/1) .
O*
R = Dilution ratio = ^
E = Treatment plant removal efficiency (%)
Q* = Total daily dry weather flow to the treatment
plant (millions of gallons) .
Q = Total daily industrial flow to which L applies
(millions of gallons) .
P = Assumed ratio of the maximum to average concen-
tration for any wastewater component in an in-
dustrial wastewater discharge.
S = Assumed portion of total that can be controlled
In this formula, L is determined for each pollutant
parameter for which an Le has been established. The di-
lution ratio (R) is estimated by determining the total flow
(Q) of all industries to be regulated for the pollutant in
question, and dividing it into the total flow to the treat-
ment plant (Q*) . Values for E, the treatment plant removal
efficiency for the pollutant parameter, should be based on
operating experience of the specific treatment plant. If
such information is unavailable, data for similar treatment
facilities presented in Section F may be utilized. The peak
to average ratio, P, is an estimate of the ratio of the
maximum concentration of a constituent in an industrial
effluent to the average concentration of the constituent for
all industries included in Q. The more tightly a pollutant
is controlled, the lower this ratio will be. The factor S
is included to account for background levels in the system.
If there is no background level for a particular pollutant,
with industry providing the total concentration, then the
value of S is 1.0. La is obtained from monitoring the
pollutant parameters of interest in the treatment plant
influent, and is included since the factor La (1-S) represents
the background concentration of a specific pollutant which
will not be controlled by the established limit.
The originators of the formula, the County Sanitation
Districts of Los Angeles County, have utilized it to aid in
determining allowable pollutant concentrations for industrial
dischargers within the system. Table C-l provides a numerical
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TABLE C-l
CALCULATION OF MAXIMUM ALLOWABLE INDUSTRIAL DISCHARGE CONCENTRATIONS
COUNTY SANITATION DISTRICTS OF LOS ANGELES COUNTY
CONSTITUENT
Le
Ocean Plan
Effluent
Limit
(mg/1)
E
Removal
Efficiency
at plant
w/Biolog .
Secondary
Treatment
Lp
Permissible
Influent
Limit to
Plant
Le
(1-E)
La
Average
Treatment
Plant Influent
Concentration
in 1974
R
Dilution
Ratio
2*
Q
(1)
(mg/1)
P
Assumed
Ratio of
Maximum
to
Average
Concentration
s
Assumed
Fraction
from
Controllable
Sources
L
Calculated
Maximum
Concentration
Allowable
in Industrial
Discharge
(%) (mg/1)
0
1
h-1
O
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Silver
Zinc
Cyanide
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
01
02
05
2
05
001
1
01
3
1
48
73
77
76
80
84
53
69
77
55
0.
0.
0.
0.
0.
0.
0.
0.
1.
0.
02
09
22
4(2)
25
008
23
032
58
24
0
0
0
0
0
0
0
0
1
0
.025
.032
.887
.635
.370
.0012
.295
.010
.99
.430
35
35
14
23
19
350
23
70
18
18
10
10
5
5
10
15
5
10
5
10
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
L = PR (Lp-La (1-S))
47
86
88
76
75
60
85
73
84
93
2
29
7
28
29
39
21
20
113
37
.4
.4
.9
.5
.9
.5
.4
.5
.5
.8
Notes (1) Dilution ratios are based on the Industrial Waste Inventories of the Sanitation Districts.
They are obtained by dividing 350 mgd by the total industrial wastewater flow of all
industries identified in the inventory as significant contributors of the particular
constituent.
(2) The limit of 0.4 mg/1 copper is based upon the toxicity relationship of copper to
biological wastewater treatment processes and is more restrictive than the influent
limit required by the Ocean Plan effluent limit. The restrictive Lp value of 0.4 mg/1
was used in lieu of Le/(l-E) in the calculation of L.
Reference: C-47e, page 7-27
-------
illustration of how the formula was applied to the ocean
standards established by the State of California for arsenic,
cadmium, chromium, copper, lead, mercury, nickel, silver,
zinc, and cyanide. The table is included herein only as a
guide for utilization of the formula, and not for the pre-
sentation of numerical information. It represents a revised
version of the table in the reference indicated, to reflect
an updating of the formula and the values of the individual
factors based on subsequent data obtained by the County
Sanitation Districts. POTW's applying the formula to their
own situation must determine applicable values for all of
the factors in the formula based on the characteristics of
the individual system. In summary, the formula provides a
systematic method for establishing specific numerical limit-
ations for industrial pollutants based on the allowable
concentration of each pollutant in the treatment plant
effluent.
Inhibition or Interference
The third major consideration in setting numerical
limitations is the inhibition of treatment processes or
interference with sludge handling or disposal operation that
may be caused by particular incompatible pollutants. In
this connection, Section E and Appendix 5 of this document
provide technical data on the inhibitory effects of both
inorganic and organic constituents of industrial waste-
waters. The data presented represents a summary of inform-
ation available in the literature on this subject. It
should be used as a guide in establishing a range of values
for specific pollutants which may inhibit or upset treatment
processes. Nevertheless, a number of factors within a given
collection and treatment system will affect the acceptable
level of a specific pollutant in a specific treatment plant.
Of the many factors to be considered, the type of treatment
process utilized is of prime importance. In addition to the
inherent differences between unit processes such as activated
sludge and trickling filtration, other treatment considerations
such as chemical addition and wastewater flow pattern strongly
affect inhibition characteristics. Consequently, information
that may be available for a particular system should be
utilized preferentially as compared to the data contained in
these guidelines.
Additional factors to be considered in setting limits
based on inhibition or interference are the natural dilution
available from other contributors to the system, and background
levels of the pollutant present in the collection system.
Dilution is primarily a function of the size of the system,
ranging from insignificant dilution in many small systems,
to extremely high levels of dulution in very large systems.
Several of the largest systems report that upset of treat-
ment processes is extremely rare, regardless of the concen-
tration of individual industrial contributions. The background
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level of a specific pollutant in a sewerage system should
also be considered in setting numerical standards based on
inhibition. Normally this is a difficult determination, but
information from systems without industrial contributors may
be helpful. Also, monitoring of all industrial dischargers
and plant influent levels, with subsequent calculations will
reveal background levels within the system.
In general, judgment is required in developing approp-
riate limitations based on inhibition of treatment processes,
and all factors affecting the determination must be taken
into account at the local level. A final consideration in
establishing limitations based on inhibition, is the incorpor-
ation of an appropriate safety factor into the numerical
limits for each pollutant. The inhibition data presented in
these guidelines summarizes the results of studies reported
in the literature indicating actual numerical values in
which inhibition or process upset was observed for specific
pollutants. Establishment of limitations based on this
information requires the use of a suitable safety factor to
ensure that adequate protection is provided for the treatment
process.
In a fashion similar to that used in the preceding
section for calculating the pass-through of incompatible
pollutants, the maximum allowable concentration of inhibitory
or interfering pollutants at the inlet to a POTW or a specific
unit process can also be calculated.
Inhibition of Treatment Plant Operations
Calculation of pollutant levels at the influent to a
treatment plant that will inhibit a unit process within the
plant can be determined using the following equation:
LP = (1 -\P)
where:
Lp = Permissible influent limit to the treatment plant.
Li = Maximum allowable concentration in the influent to
the unit process that will not inhibit that unit
process.
Ep = Removal efficiency of the unit processes upstream
of the unit process of concern.
Once Lp has been determined using this formula, concen-
tration limits at the point of industrial contribution can
be ascertained by substituting Lp for Le in the Los Angeles
County formula and calculating L.
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Bo.th Li and Ep are unique for each treatment plant and
should be determined in advance before attempting any cal-
culations, For illustrative purposes, approximate values
for Li and Ep can be obtained from Sections E and F of this
document. In Section E, specific levels of incompatible
pollutants which have been found to be deleterious to the
efficient operation of biological treatment processes have
been listed. The inhibitory levels given focus on the con-
centrations of particular dissolved chemical species in the
influent to specific wastewater treatment unit processes.
For example, in Table E-l three ranges of copper concen-
trations experimentally found to be inhibitory to activated
sludge, anaerobic digestion and nitrification processes are
listed. From these ranges, values of 1, 5 and 0.1 mg/1 have
been used for Li in sample calculations for inhibition of
activated sludge, anaerobic digestion and nitrification
processes, respectively.
Similarly, Section F addresses the subject of removal
and pass through of pollutants in POTW's. Table F-2 lists
average removals for copper in primary and activated sludge
plants as 26% .and 57%, respectively. These numbers are used
in the following sample calculations.
- Activated Sludge Processes
Using 1 mg/1 for Li and 0.26 for Ep since some
copper will be removed in primary treatment prior to the
activated sludge process, the permissible copper concentra-
tion in the influent to the treatment plant is calculated as
follows:
LP = - = (1 - .26) = 1>35 mg/1
- Nitrification Processes
Since a standard activated sludge plant will
precede most nitrification processes, 0.57 is appropriate
for Ep. Using 0.1 mg/1 for Li, the permissible copper concen-
tration to avoid inhibition of nitrification processes is
calculated as follows:
' = °'23
I-lp- (1 -057)
- Anaerobic Digestion
The type of calculation completed above cannot be
directly applied to anaerobic digestion processes. In a
digester, inhibitory materials may be present as either
aqueous species or as insoluble precipitates. High concen-
trations of potentially inhibitory materials, inorganics in
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particular, are frequently observed in digester sludge with
no apparent decrease in operating efficiency. This is
explained by the fact that the high levels typically result
from a concentration of insoluble inorganic materials, which
do not impact on biological activity.
The major concern in anaerobic digestor operations
is the concentration of inhibitory materials in the super-
natant transferred with the sludge solids. Many of the
concentrations of inhibitory materials cited in Section E
for anaerobic sludge digestion refer to the concentration of
pollutants in the supernatant entering the digestor with the
raw sludge. The complicating factor in attempting to complete
calculations such as those shown above is that the chemical
environment in a digestor such as pH changes or the presence
of sulfide, often causes the pollutant to precipitate before
inhibiting the process. Therefore, calculations of limits
based on inhibition of anaerobic digestion processes require
a detailed evaluation of each individual plant's operations,
and cannot be adequately illustrated in general terms.
It is important to observe that the inhibitory
concentration observed for activated sludge processes may be
higher than that for nitrification or anaerobic digestion
processes. Since the activated sludge process utilizes many
different bacteria, it can more readily withstand the effects
of an inhibitory substance by adapting to the changing
environment. On the other hand, nitrification and anaerobic
digestion processes rely on the performance of a single
strain of bacteria, thus making these processes less adapt-
able to the presence of inhibitory pollutants.
Interference with Sludge Handling or Disposal Operations
Essentially any inorganic material removed in a typical
biological treatment process is contained in the sludge
wasted from the system. Using the example of a 57% copper
removal cited above for an activated sludge plant, it is
possible to determine the level of copper expected in the
raw sludge. Assuming 1.0 mg/1 of copper is present in the
influent to a 1 MGD plant, then the quantity of copper found
in the sludge can be calculated as follows:
Copper in Sludge = 1'° ""' ('57) =4.75 Ib/day
Since a typical activated sludge plant produces 20,000
gallons of sludge containing 1% solids, per million gallons
daily, the concentration of copper in the waste sludge may
be calculated as follows:
Copper in Waste Sludge = 4 ' 7 (r 000) =28.5 mg/1
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The dewatering of this sludge to a typical 20% concen-
tration, prior to disposal, would increase the copper concen-
tration to 570 mg/1. This calculation demonstrates that for
a relatively small concentration of copper in the plant
influent, the final concentration in the sludge is relatively
high. As a result, it may be necessary to establish limits
on the level of pollutants entering the plant, on the basis
of the ultimate disposal of sludge. The example cited above
shows that one of the most critical impacts of industrial
contributions of incompatible pollutants may be interference
with sludge disposal operations.
As with setting limits to avoid inhibition of anaerobic
digestion processes, calculating limits to protect against
interference with sludge handling and disposal methods is
difficult. Factors such as digestor detention time, methods
of decanting and mixing, and various other operational con-
siderations may impact on the quality of dewatered sludge
obtained. Consequently, factors of this type should be
defined prior to attempting to calculate limits based on
interference with sludge handling or disposal operations.
Summary
Responsible State or local regulating agencies should
recognize that concentration based limitations have some in-
herent deficiencies, particularly where the ordinances'
numerical limitations are intended to meet water quality
requirements. Mainly, in cases where water and sewer costs
are less than the cost of installing and operating pretreat-
ment facilities, industrial dischargers may be tempted to
use dilution to comply with the concentration limitations,
resulting in the degradation of water quality. Dilution
could result from the addition of city water, non-contact
cooling water or relatively clean process water or storm
water.
To detect diluters, the responsible authority should
review industrial plans and specifications for pretreatment
facilities, and use on-site inspection of pretreatment
facilities and plant piping to determine that the appro-
priate pretreatment facilities have been installed, are
being operated, and that there are no permanent connections
for dilution water. Additionally, close surveillance of
water meter readings and records can often pinpoint diluters.
However, this is usually most effective when the concen-
tration limitations first become effective and are first
enforced. With these safeguards, concentration limitations
will usually provide an effective and enforceable means of
preventing interference with treatment processes or the pass
through of pollutants which could cause the POTW to violate
its permit conditions or water quality standards.
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Other Regulatory Sections
Section 3 of the recommended ordinance establishes the
authority and procedure for the control of prohibited wastes.
It includes the necessary clauses relative to regulatory
actions, submission of plans for pretreatment facilities,
proper operation and maintenance of pretreatment facilities,
admission of POTW personnel to industrial plants and reporting
of accidental discharges. Section 4 of the ordinance is
devoted to sampling and analysis of industrial wastewater.
Several clauses are included with regard to monitoring and
record keeping, encompassing the type and frequency of
samples required. Section D of these guidelines includes a
complete summary of monitoring information for the sampling
and analysis of industrial wastewaters.
The sections of the recommended ordinance dealing with
enforcement provides a structured approach for the handling
of violations. The first step in the procedure is notifi-
cation in writing of the violation, which would generally be
followed by conference and conciliation. If these steps are
unsuccessful in solving the problem, then more formal pro-
ceedings are instituted. The first is a show cause hearing,
which provides the violator with an opportunity to show
cause why an order should not be issued directing the dis-
continuance of the discharge. Show cause hearings are
usually open to the public, and held before a hearing board
composed of appropriate officials of the municipality,
authority or district. Upon submission of all evidence, the
hearing board has the option of issuing an order for the
cessation of the discharge within a specified time period.
If an order is issued, and not complied with, then court
action is the next and final step in enforcement of the
ordinance. This step-by-step approach to enforcement pro-
vides the maximum opportunity for the resolution of ordinance
violations without resorting to court proceedings until
absolutely necessary.
Optional and Procedural Clauses
An optional clause is included in the recommended
ordinance pertaining to a permit program for industrial
contributors to the system. Local permit programs are most
applicable to large systems, and to date have been used
successfully by several large regional agencies. Permit
programs greatly increase the paper work associated with
industrial pollutant control programs. Although the onus for
filing permits is placed on the industries in the system,
the POTW must nevertheless scrutinize the permits for completeness,
truthfulness, accuracy, etc. The use of permits can be
particularly advantageous in instituting a control program
in a large system. At the outset, industries must provide all
C-16
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relevant information on their discharges, thus relieving the
POTW staff from this initial data gathering task. Local
permit programs offer an option which is systematic and
thorough, but one which requires a well-trained capable staff
to administer.
The procedural clauses included in the recommended
ordinance serve several varying functions. The principal
clause provides that the bulk of the ordinance remains in
force if any section is declared invalid or unconstitutional.
Only the affected section is no longer in force, thus "saving
the remainder of the ordinance. This section also references
other related ordinances and reconciles differences that may
exist between the various ordinances. Finally, the pro-
cedural clauses also set forth the date that the ordinance
becomes effective.
Recommended Ordinance
The following pages contain the recommended industrial
waste ordinance as outlined in the preceding paragraphs that
may be utilized by a typical municipality, sewer district or
authority. This ordinance is presented herein for reference
purposes only, and it should be tailored to meet the needs
of the specific governmental jurisdiction.
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ORDINANCE NO.
AN ORDINANCE establishing rules and regu-
lations for the discharge of wastewaters into
the wastewater treatment system of the City
of .
WHEREAS, the Federal Water Pollution Con-
trol Act Amendments of 1972, P.L. 92-500
(hereinafter referred to as the "Act") have
resulted in an unprecedented program of
cleaning up our Nation's waters;
WHEREAS, this City has already made and
will continue to make a substantial financial
investment in its wastewater treatment system
to achieve the goals of the Act; and,
WHEREAS, this City seeks to provide for
the use of its wastewater treatment system by
industries served by it without damage to the
physical facilities, without impairment of
their normal function of collecting, treating
and discharging domestic wastewater, and with-
out the discharge by this City's wastewater
treatment system of pollutants which would
violate the discharge allowed under its
National Pollutant Discharge Elimination System
(NPDES) permit and the applicable rules of all
governmental authorities with jurisdiction
over such discharges.
NOW, THEREFORE, BE IT ORDAINED AND ENACTED
by the City Council of the City of ,
County of , State of ,
as follows:
SECTION 1; DEFINITIONS.
Unless the context specifically
indicates otherwise, the following terms, as
used in this Ordinance, shall have the meanings
hereinafter designated:
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(a) "Biochemical Oxygen Demand"
(BOD) means the quantity of oxygen utilized in
the biochemical oxidation of organic matter
under standard laboratory procedure in five
(5) days at 20 C, expressed in terms of weight
and concentration (milligrams per liter).
(b) "Cooling Water" means the
water discharged from any use such as air
conditioning, cooling or refrigeration, during
which the only pollutant added to the water is
heat.
(c) "Compatible pollutant" means
BOD, suspended solids, pH and fecal coliform
bacteria, and such additional pollutants as are
now or may be in the future specified and con-
trolled in this City's NPDES permit for its
wastewater treatment works where said works
have been designed and used to reduce or remove
such pollutants.
(d) "Director "/P'Superintendent"]
means the [director/superintendent of waste-
water treatment system/of water pollution
control/of public works] of this City or his
duly appointed deputy, agent or representative.
(e) "Domestic wastes" means
liquid wastes (i) from the non-commercial pre-
paration, cooking and handling of food or (ii)
containing human excrement and s'imilar matter
from the sanitary conveniences of dwellings,
commercial buildings, industrial facilities,
and institutions.
(f) "Garbage" means solid wastes
from the domestic and commercial preparation,
cooking and dispensing of food, and from the
handling, storage and sale of food.
(g) "Incompatible pollutant"
means any pollutant which is not a "compatible
pollutant" as defined in this section.
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(h) "Industrial wastewater"
means the liquid wastes resulting from the
processes employed in industrial, manufac-
turing, trade or business establishments, as
distinct from domestic wastes.
(i) "National Pollutant Dis-
charge Elimination System" (NPDES) means the
program for issuing, conditioning and denying
permits for the discharge of pollutants from
point sources into the navigable waters, the
contiguous zone and the oceans pursuant to
section 402 of the Act.
(j) "Person" means any individual,
firm, company, partnership, corporation,
association, group or society, and includes
the State of , and agencies, dis-
tricts, commissions and political subdivisions
created by or pursuant to State law.
(k) "pH" means the logarithm of
the reciprocal of the concentration of hydrogen
ions in grams per liter of solution.
(1) "Pretreatment" means appli-
cation of physical, chemical and biological
processes to reduce the amount of pollutants
in or alter the nature of the pollutant proper-
ties in a wastewater prior to discharging such
wastewater into the publicly owned wastewater
treatment system.
(m) "Pretreatment standards"
means all applicable Federal rules and regu-
lations implementing section 307 of the Act,
as well as any nonconflicting State or local
standards. In cases of conflicting standards
or regulations, the more stringent thereof shall
be applied.
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(n) "Significant industrial user"
means any industrial user of the City's waste-
water treatment system whose flow exceeds (i)
[50,000] gallons per day, or (ii) [five (5)]
percent of the daily capacity of the treatment
system.
(o) "Storm Water" means any flow
occurring during or immediately following any
form of natural precipitation and resulting
therefrom.
(p) "Suspended solids" means the
total suspended matter that floats on the sur-
face of, or is suspended in, water, wastewater
or other liquids, and which is removable by
laboratory filtering.
(q) "Unpolluted Water" is water
not containing any pollutants limited or pro-
hibited by the effluent standards in effect, or
water whose discharge will not cause any violation
of receiving water quality standards.
(r) "User" means any person who
discharges, causes or permits the discharge of
wastewater into the City's wastewater treatment
system.
(s) "User classification" means
a classification of user based on the 1972 (or
subsequent) edition of the Standard Industrial
Classification (SIC) Manual prepared by the
Office of Management and Budget.
(t) "Wastewater" means the liquid
and water-carried industrial or domestic
wastes from dwellings, commercial buildings,
industrial facilities, and institutions,
together with any groundwater, surface water,
and storm water that may be present, whether
treated or untreated, which is discharged into
or permitted to enter the City's treatment
works.
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(u) "Wastewater treatment system"
(system) means any devices, facilities, struc-
tures, equipment or works owned or used by the
City for the purpose of the transmission,
storage, treatment, recycling, and reclamation
of industrial and domestic wastes, or necessary
to recycle or reuse water at the most economical
cost over the estimated life of the system,
including intercepting sewers, outfall sewers,
sewage collection systems, pumping, power, and
other equipment, and their appurtenances;
extensions, improvements, remodeling, additions,
and alterations thereof; elements essential to
provide a reliable recycled supply such as
standby treatment units and clear well facilities;
and any works, including site acquisition of the
land that will be an integral part of the treat-
ment process or is used for ultimate disposal
of residues resulting from such treatment.
(v) Terms not otherwise defined
herein shall be as adopted in the latest
edition of Standard Methods for the Examination
of Water & Wastewater, published by the American
Public Health Association, the American Water
Works Association and the Water Pollution
Control Federation.
SECTION 2; PROHIBITIONS AND LIMITATIONS
ON WASTEWATER DISCHARGES
(a) Prohibitions on Wastewater
Discharges. No person shall discharge or deposit
or cause or allow to be discharged or deposited
into the wastewater treatment system any waste-
water which contains the following:
(1) Oils and Grease. (A) Oil
and grease concentrations or amounts from
industrial facilities violating Federal pre-
treatment standards. (B) Wastewater from indus-
trial facilities containing floatable fats, wax,
grease or oils. [Optional: (C) Wax, grease or
oil concentration of mineral origin of more
than ( ) mg/1 whether emulsified or not,
or containing substances which may solidify
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or become viscous at temperatures between
32° and 150°F (0° and 65 C) at the point of
discharge into the system.] [optional: (D)
Total fat, wax, grease or oil concentration
of more than ( )mg/l, whether emulsified
or not, or containing substances which may
solidify or become viscous at temperatures
between 32°and 150°F(0°and 65°C) at the point
of discharge into the system.]
(2) Explos ive Mixtures.
Liquids, solids or gases which by reason of
their nature or quantity are, or may be, suf-
ficient either alone or by interaction with
other substances to cause fire or explosion or
be injurious in any other way to the sewerage
facilities or to the operation of the system.
At no time shall two successive readings on an
explosion hazard meter, at the point of dis-
charge into the sewer system, be more than five
percent (5%) nor any single reading over ten per-
cent (10%) of the Lower Explosive Limit (L.E.L.)
of the meter. Prohibited materials include,
but are not limited to, gasoline, kerosene,
naphtha, benzene, toluene, zylene, ethers, alcohols,
ketones, aldehydes, peroxides, chlorates, per-
chalorates, bromates, carbides, hydrides and
sulfides.
(3) Noxious Material. Noxious
or malodorous solids, liquids or gases, which,
either singly or by interaction with other
wastes, are capable of creating a public
nuisance or hazard to life, or are or may be
sufficient to prevent entry into a sewer for
its maintenance and repair.
(4) Improperly Shredded Garbage.
Garbage that has not been ground or comminuted
to such a degree that all particles will be
carried freely in suspension under flow con-
ditions normally prevailing in the public sewers,
with no particle greater than one-half (1/2)
inch in any dimension.
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(5) Radioactive Wastes.
Radioactive wastes or isotopes of such half-
life or concentration that they do not comply
with regulations or orders issued by the approp-
riate authority having control over their use
and which will or may cause damage or hazards
to the sewerage facilities or personnel opera-
ting the system.
(6) Solid or Viscous Wastes.
Solid or viscous wastes which will or may cause
obstruction to the flow in a sewer, or otherwise
interfere with the proper operation of the waste-
water treatment system. Prohibited materials
include, but are not limited to, grease, uncom-
minuted garbage, animal guts or tissues, paunch
manure, bones, hair, hides or fleshings, entrails,
whole blood, feathers, ashes, cinders, sand,
spent lime, stone or marble dust, metal, glass,
straw, shavings, grass clippings, rags, spent
grains, spent hops, waste paper, wood, plastic,
tar, asphalt residues, residues from refining
or processing of fuel or lubricating oil, and
similar substances.
(7) Excessive Discharge Rate.
Wastewaters at a flow rate or containing such
concentrations or quantities of pollutants that
exceeds for any time period longer than fifteen
(15) minutes more than five (5) times the average
twenty-four (24) hour concentration, quantities
or flow during normal operation and that would
cause a treatment process upset and subsequent
loss of treatment efficiency.
(8) Toxic Substances. Any
toxic substances in amounts exceeding standards
promulgated by the Administrator of the United
States Environmental Protection Agency pursuant
to section 307(a) of the Act, and chemical
elements or compounds, phenols or other taste-
or odor-producing substances, or any other sub-
stances which are not susceptible to treatment
or which may interfere with the biological
processes or efficiency of the treatment system,
or that will pass through the system.
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(9) Unpolluted Waters. Any
unpolluted water including, but not limited to,
water from cooling systems or of stormwater
origin, which will increase the hydraulic
load on the treatment system.
(10) Discolored Material.
Wastes with objectionable color not removable
by the treatment process.
(11) Corrosive Wastes. Any
waste which will cause corrosion or deterioration
of the treatment system. All wastes discharged
to the public sewer system must have a pH value
in the range of [6] to [B] standard units.
Prohibited materials, include, but are not
limited to, acids, sulfides, concentrated
chloride and fluoride compounds and substances
which will react with water to form acidic
products.
(b) Limitations on Wastewater
Discharges. [use either Option A or Option B]
[Option A - General Limitations]
No person shall discharge or
convey, or permit or allow to be discharged or
conveyed, to a public sewer any wastewater con-
taining pollutants of such character or quantity
that will:
(1) Not be susceptible to
treatment or interfere with the process or
efficiency of the treatment system.
(2) Constitute a hazard to
human or animal life, or to the stream or water
course receiving the treatment plant effluent.
(3) Violate pretreatment
standards.
(4) Cause the treatment
plant to violate its NPDES permit or applicable
receiving water standards.
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[Option B - Specific Limitations]
The following are the maximum
concentrations of pollutants allowable in waste-
water discharges to the wastewater treatment
system. Dilution of any wastewater discharge
for the purpose of satisfying these requirements
shall be considered a violation of this Ordinance.
Pollutant
Arsenic
Barium
Boron
Cadmium
Chromium (total
Chromium (Trivalent)
Chromium (Hexavalent)
Chlorinated Hydrocarbons
Copper
Cyanide
Iron
Lead
Manganese
Mercury
Nickel
Phenolic Compounds
Phosphorus
Selenium
Silver
Surfactants
Zinc
PH
Temperature
Concentration(mg/1) or
Mass Limitations(kg/kkq)
[Options: See, e.g.
Federal Guidelines;
State and Local Pre-
treatment Programs,
Volume I, Section c]
Not over 150 F (except
where higher tempera-
tures are permitted
by law)
(c) Special Agreements. Nothing
in this section shall be construed as preventing
any special agreement or arrangement between the
City and any user of the wastewater treatment
system whereby wastewater of unusual strength
or character is accepted into the system and
specially treated subject to any payments or
user charges as may be applicable.
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SECTION 3; CONTROL OF PROHIBITED WASTES
(a) Regulatory Actions. If waste-
waters containing any substance described in
Section 2 of this Ordinance are discharged or
proposed to be discharged into the sewer system
of the City or to any sewer system tributory
thereto, the Director and [corporation Counsel/
City Attorney] may take any action necessary to:
(1) Prohibit the discharge
of such wastewater.
(2) Require a discharger to
demonstrate that in-plant modifications will
reduce or eliminate the discharge of such sub-
stances in conformity with this Ordinance.
(3) Require pretreatment,
including storage facilities, or flow equalization
necessary to reduce or eliminate the objectionable
characteristics or substances so that the dis-
charge will not violate these rules and regulations.
(4) Require the person making,
causing or allowing the discharge to pay any
additional cost or expense incurred by the City
for handling and treating excess loads imposed
on the treatment system.
(5) Take such other remedial
action as may be deemed to be desirable or necessary
to achieve the purpose of this Ordinance.
(b) Submission of Plans. Where pre-
treatment or equalization of wastewater flows prior
to discharge into any part of the wastewater
treatment system is required, plans, specifi-
cations and other pertinent data or information
relating to such pretreatment or flow-control
facilities shall first be submitted to the
Director for review and approval. Such approval
shall not exempt the discharge or such facilities
from compliance with any applicable code, ordinance,
rule, regulation or order of any governmental
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authority. Any subsequent alterations or
additions to such pretreatment or flow-control
facilities shall not be made without due notice
to and prior approval of the Director.
(c) Pretreatment Facilities
Operations. If pretreatment or control of waste
flows is required, such facilities shall be
maintained in good working order and operated
as efficiently as possible by the owner or
operator at his own cost and expense, subject
to the requirements of these rules and regula-
tions and all other applicable codes, ordinances,
and laws.
(d) Admission to Property. When-
ever it shall be necessary for the purposes of
these rules and regulations, the Director, upon
the presentation of credentials, may enter upon
any property or premises at reasonable times
for the purpose of (1) copying any records
required to be kept under the provisions of
this Ordinance, (2) inspecting any monitoring
equipment or method , and (3) sampling any dis-
charge of wastewater to the treatment works.
The Director may enter upon the property at any
hour under emergency circumstances.
(e) Protection from Accidental
Discharge. Each industrial user shall provide
protection from accidental discharge of pro-
hibited materials or other wastes regulated by
this Ordinance. Facilities to prevent accidental
discharge of prohibited materials shall be pro-
vided and maintained at the owner or operator's
own cost and expense. Detailed plans showing
facilities and operating procedures to provide
this protection shall be submitted to the
Director for review, and shall be approved by
him before construction of the facility. Review
and approval of such plans and operating pro-
cedures shall not relieve the industrial user
from the responsibility to modify his facility
as necessary to meet the requirements of this
Ordinance.
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(f) Reporting of Accidental
Discharge. If, for any reason, a facility
does not comply with or will be unable to comply
with any prohibition or limitations in this
Ordinance, the facility responsible for such
discharge shall immediately notify the Director
so that corrective action may be taken to pro-
tect the treatment system. In addition, a
written report addressed to the Director detailing
the date, time and cause of the accidental dis-
charge, the quantity and characteristics of
the discharge and corrective action taken to
prevent future discharges, shall be filed by
the responsible industrial facility within
five (5) days of the occurrence of the noncom-
plying discharge.
SECTION 4; INDUSTRIAL WASTEWATER
MONITORING AND REPORTING
(a) Discharge Reports.
(1) Every significant
industrial user shall file a periodic Discharge
Report at such intervals as are designated by
the Director. The Director may require any other
industrial users discharging or proposing to
discharge into the treatment system to file
such periodic reports.
(2) The discharge report
shall include, but, in the discretion of the
Director, shall not be limited to, nature of
process, volume, rates of flow, mass emission
rate, production quantities, hours of operation,
concentrations of controlled pollutants or
other information which relates to the generation
of waste. Such reports may also include the
chemical constituents and quantity of liquid
materials stored on site even though they are
not normally discharged. In addition to dis-
charge reports, the Director may require infor-
mation in the form of [industrial Discharge
Permit Applications and (optional)] self-monitoring
reports.
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(b) Records and Monitoring.
(1) All industrial users
who discharge or propose to discharge waste-
waters to the wastewater treatment system shall
maintain such records of production and related
factors, effluent flows, and pollutant amounts
or concentrations as are necessary to demonstrate
compliance with the requirements of this Ordinance
and any applicable State or Federal pretreatment
standards or requirements.
(2) Such records shall be
made available upon request by the Director. All
such records relating to compliance with pre-
treatment standards shall be made available to
officials of the U. S. Environmental Protection
Agency upon demand. A summary of such data
indicating the industrial user's compliance with
this Ordinance shall be prepared [quarterly]
(optional) and submitted to the Director.
(3) The owner or operator of
any premises or facility discharging industrial
wastes into the system shall install at his own
cost and expense suitable monitoring equipment
to facilitate the accurate observation, sampling,
and measurement of wastes. Such equipment shall
be maintained in proper working order and kept
safe and accessible at all times.
(4) The monitoring equipment
shall be located and maintained on the industrial
user's premises outside of the building. When
such a location would be impractical or cause
undue hardship on the user, the Director may
allow such facility to be constructed in the
public street or sidewalk area, with the approval
of the public agency having jurisdiction over
such street or sidewalk, and located so that it
will not be obstructed by public utilities,
landscaping or parked vehicles.
(5) When more than one user
can discharge into a common sewer, the Director
may require installation of separate monitoring
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equipment for each user. When there is a
significant difference in wastewater constituents
and characteristics produced by different
operations of a single user, the Director may
require that separate monitoring facilities be
installed for each separate discharge.
(6) Whether constructed on
public or private property, the monitoring
facilities shall be constructed in accordance
with the Director's requirements and all appli-
cable construction standards and specifications.
(c) Inspection, Sampling and
Analysis.
(1) Compliance Determination.
Compliance determinations with respect to Section 2
prohibitions and limitations may be made on the
basis of either instantaneous grab samples or
composite samples of wastewater. Composite samples
may be taken over a 24 hour period, or over a
longer or shorter time span, as determined
necessary by the Director to meet the needs of
specific circumstances.
(2) Analysis of Industrial
Wastewaters. Laboratory analysis of industrial
wastewater samples shall be performed in accordance
with the current edition of "Standard Methods",
"Methods for Chemical Analysis of Water and
Waste" published by the U. S. Environmental
Protection Agency or the "Annual Book of Standards,
Part 23, Water, Atmospheric Analysis" published
by the American Society for Testing and Materials.
Analysis of those pollutants not covered by
these publications shall be performed in accor-
dance with procedures established by the [State
Department of Environmental Health.J
(3) Sampling Frequency
[Optional]. Sampling of industrial wastewater
for the purpose of compliance determination with
respect to Section 2 prohibitions and limitations
will be done at such intervals as the Director
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may designate. However, it is the intention of
the Director to conduct compliance sampling or
to cause such sampling to be conducted for all
major contributing industries at least once
in every (1 year) (optional) period.
SECTION 5; INDUSTRIAL DISCHARGE PERMIT
SYSTEM [OPTIONAL]
(a) wastewater Discharge Permits
Required. All significant industrial users pro-
posing to connect to or discharge into any
part of the wastewater treatment system must
first obtain a discharge permit therefor. All
existing significant industrial users connected
to or discharging to any part of the City system
must obtain a wastewater discharge permit within
ninety (90) (optional) days from and after the
effective date of this Ordinance.
(b) Permit Application. Users
seeking a wastewater discharge permit shall com-
plete and file with the Director an application
on the form prescribed by the Director, and
accompanied by the applicable fee. In support
of this application, the user shall submit the
following information:
(1) Name, address, and SIC
number of applicant.
(2) Volume of wastewater to
be discharged.
(3) Wastewater constituents
and characteristics including, but not limited
to, those set forth in Section 2 of this
Ordinance as determined by a reliable analytical
laboratory.
(4) Time and duration of
discharge.
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(5) Average and [30]
(optional) minute peak wastewater flow rates,
including daily, monthly and seasonal variations,
if any.
(6) Site plans, floor plans,
mechanical and plumbing plans and details to
show all sewers and appurtenances by size,
location and elevation.
(7) Description of activities,
facilities and plant processes on the premises
including all materials and types of materials
which are, or could be, discharged.
(8) Each product produced
by type, amount, and rate of production.
(9) Number and type of
employees, and hours of work.
(10) Any other information
as may be deemed by the Director to be necessary
to evaluate the permit application.
The Director will evaluate the data furnished
by the user and may require additional information.
After evaluation and acceptance of the data fur-
nished, the Director may issue a wastewater
discharge permit subject to terms and conditions
provided herein.
(c) Permit Conditions. Waste-
water discharge permits shall be expressly sub-
ject to all provisions of this Ordinance and
all other regulations, user charges and fees
established by the City. The conditions of
wastewater discharge permits shall be uniformly
enforced in accordance with this Ordinance, and
applicable State and Federal regulations. Per-
mit conditions will include the following:
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(1) The unit charge or
schedule of user charges and fees for the waste-
water to be discharged to the system.
(2) The average and maximum
wastewater constituents and characteristics.
(3) Limits on rate and time
of discharge or requirements for flow regulations
and equalization.
(4) Requirements for installa-
tion of inspection and sampling facilities, and
specifications for monitoring programs.
(5) Requirements for main-
taining and submitting technical reports and
plant records relating to wastewater discharges.
(6) Daily average and daily
maximum discharge rates, or other approp-
riate conditions when pollutants subject to
limitations and prohibitions are proposed or
present in the user's wastewater discharge.
(7) Compliance schedules.
(8) Other conditions to
ensure compliance with this Ordinance.
(d) Duration of Permits. Permits
shall be issued for a specified time period,
not to exceed (five) (optional) years. A per-
mit may be issued for a period of less than
(one) (optional) year, or may be stated to
expire on a specific date. If the user is not
notified by the Director (30) (optional) days
prior to the expiration of the permit, the permit
shall automatically be extended for (x) months.
The terms and conditions of the permit may be
subject to modification and change by the
(responsible official) during the life of the
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permit, as limitations or requirements as
identified in Section 2 are modified and
changed. The user shall be informed of any
proposed changes in his permit at least (30)
(optional) days prior to the effective date of
change. Any changes or new conditions in the
permit shall include a reasonable time schedule
for compliance.
(e) Transfer of a Permit.
Wastewater discharge permits are issued to a
specific user for a specific operation. A
wastewater discharge permit shall not be reassigned
or transferred or sold to a new owner, new user,
different premises, or a new or changed operation.
(f) Revocation of Permit. Any
user who violates the following conditions of
his permit or of this Ordinance, or of appli-
cable State and Federal regulations, is subject
to having his permit revoked. Violations sub-
jecting a user to possible revocation of his
permit include, but are not limited to, the
following:
(1) Failure of a user to
accurately report the wastewater constituents
and characteristics of his discharge;
(2) Failure of the user to
report significant changes in operations, or
wastewater constituents and characteristics;
(3) Refusal of reasonable
access to the user's premises for the purpose
of inspection or monitoring; or,
(4) Violation of conditions
of the permit.
SECTION 6; ENFORCEMENT PROCEDURES
(a) Notification of Violation.
Whenever the Director finds that any person has
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violated or is violating his Ordinance, or any
prohibition, limitation or requirement con-
tained herein, he may serve upon such person
a written notice stating the nature of the
violation and providing a reasonable time, not
to exceed thirty (30) days, for the satisfactory
correction thereof.
(b) Show Cause Hearing.
(1) if the violation is not
corrected by timely compliance, the Director may
order any person who causes or allows an unautho-
rized discharge to show cause before the (hearing
authority) why service should not be terminated.
A notice shall be served on the offending party,
specifying the time and place of a hearing to
be held by the [hearing authority] regarding the
violation, and directing the offending party to
show cause before [said authority] why an order
should not be made directing the termination of
service. The notice of the hearing shall be
served personally or by registered or certified
mail (return receipt requested) at least [ten]
days before the hearing. Service may be made on
any agent or officer of a corporation.
(2) The [hearing authority]
may itself conduct the hearing and take the
evidence, or may designate any of its members
or any officer or employee of the [assigned
department] to:
(A) Issue in the name
of the [hearing authority] notices of hearings
requesting the attendance and testimony of
witnesses and the production of evidence rele-
vant to any matter involved in any such hearings.
(B) Take the evidence.
(C) Transmit a report
of the evidence and hearing, including trans-
cripts and other evidence, together with
recommendations to the [hearing authority^ for
action thereon.
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(3) At any public hearing,
testimony taken before the- hearing authority
or any person designated by it, must be under
oath and recorded stenographically. The trans-
cript, so recorded, will be made available to
any member of the public or any part to the.
hearing upon payment of the usual charges
therefor.
(4) After the [hearing
authority] has reviewed the evidence, it may
issue an order to the party responsible for
the discharge directing that, following a speci-
fied time period, the sewer service be discon-
tinued unless adequate treatment facilities,
devices or other related appurtenances shall
have been installed or existing treatment
facilities, devices or other related appur-
tenances are properly operated, and such
further orders and directives as are necessary
and appropriate.
(c) Legal Action. Any discharge
in violation of the substantive provisions of
this Ordinance or an Order of the [hearing
authority] shall be considered a public nuisance.
If any person discharges sewage, industrial
wastes or other wastes into the City treatment
system contrary to the substantive provisions
of this Ordinance or any Order of the [hearing
authority^, the [Corporation Counsel/City
AttorneyJ shall commence an action for appro-
priate legal and/or equitable relief in the
[Circuit"] Court of this County.
SECTION 7; PENALTY; COSTS
Any person who is found to have vio-
lated an Order of the [hearing authority] or
who willfully or negligently failed to comply
with any provision of this Ordinance, and the
orders, rules and regulations issued hereunder,
shall be fined not less than fOne Hundred Dollars]
(optional) nor more than [One Thousand Dollars^
(optional) for each offense. Each day on which
a violation shall occur or continue shall be
C-37
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deemed a separate and distinct offense. in
addition to the penalties provided herein, the
City may recover reasonable attorneys' fees,
court costs, court reporters' fees and other
expenses of litigation by appropriate suit at
law against the person found to have violated
this Ordinance or the orders, rules and regu-
lations issued hereunder.
SECTION 8; SAVINGS CLAUSE
If any provision, paragraph, word,
section or article of this Ordinance is invali-
dated by any court of competent jurisdiction,
the remaining provisions, paragraphs, words,
sections, and articles shall not be affected
and shall continue in full force and effect.
SECTION 9; CONFLICT
All ordinances and parts of ordinances
inconsistent or conflicting with any part of
this Ordinance are hereby repealed to the extent
of such inconsistency or conflict.
SECTION 10; EFFECTIVE DATE
This Ordinance shall be in full force
and effect [Option A] from and after its
passage, approval and publication, as provided
by law. [Option B ] on the day of , 19 .
INTRODUCED the day of , 19 .
FIRST READING: , 19 .
SECOND READING: , 19 .
PASSED this day of , 19 .
AYES:
NAYS:
ABSENT:
NOT VOTING:
APPROVED by me this day of , 19_
MAYOR
ATTEST: (Seal) City Clerk
Published the day of , 19
C-3R
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SECTION D
MONITORING
Functions of a Monitoring Program
Introduction
Development of a Data Base
Scheduled Monitoring
Unscheduled Surveillance
Demand Monitoring
Self-Monitoring
Enforcement
Field Considerations in Monitoring
Background
Scheduled Monitoring
Scheduling
Preparation for a Monitoring Visit
Equipment
Sample Handling
Chain of Possession
On-Site Safety
Equipment Set-up and Field Analysis
Continuous On-Line Monitoring
Demand Monitoring
Laboratory Considerations in Monitoring
Standard Analytical Techniques
Analytical Quality Control
Equipment
Atomic Absorption
Specific Ion Electrodes
Automatic Analyzers
Gas Chromatography
IR-UV Spectrophotometry
Personnel and Degree of Expertise
Special Analytical Considerations
Correlation of Analytical Techniques
Standard Reporting Procedures
Contracting for Analytical Services
Conducting an Industrial Waste and Pretreatment Survey
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SECTION D
MONITORING
Functions of a Monitoring Program
Introduction
As outlined in the preceding sections, the management of
a pollutant control program requires a constant flow of infor-
mation on the quality and quantity of industrial contributions
to the publicly owned system. In general, the function of a
monitoring program is to provide a mechanism by which the POTW
operator can obtain information on the pollutants introduced
into the sewer system. The information obtained through mon-
itoring activities may then be applied to specific areas of
concern to the municipality. These specific areas include
compliance to ordinance requirements, ascertaining user charge
fees, and completion of reports required by EPA. Additionally,
the POTW operator may use monitoring information to determine
the contributors who are responsible for releasing materials
potentially harmful to collection or treatment systems.
Depending on the specific situation, information obtained
by monitoring may also be used in the development of the
ordinance and in its enforcement. Monitoring information can
be especially useful in developing those sections of the
ordinance that set levels for incompatible pollutants, as
well as determining orders of magnitude for an equitable
system of user charge fees. As a result, ordinance devel-
opment and enforcement work hand in hand with monitoring
activities.
Although monitoring in a broad sense performs the single
function of transferring quantitative and qualitative informa-
tion on non-residential contributors, specific subfunctions
should also be completed to provide a total program. For mon-
itoring, there are well defined intermediate steps that should
be accomplished during the course of the overall program. In
a well managed system for industrial pollutant control, informa-
tion should be transferred in a closed loop where monitoring,
ordinance" compliance, ordinance enforcement and user
charge fees determination all input to one another. A
typical monitoring feedback system is depicted in Figure D-l.
Each of the monitoring functions shown are discussed in detail
in the following paragraphs. The interrelation of each function
is addressed with commentary included on the implementation of
the specific monitoring activity.
D-l
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DATA BASE
DEVELOPMENT
REPORTS TO
EPA
n
SELF
MONITORING
DEVELOPMENT OF
COMPLIANCE AND
SURCHARGE SYSTEM
Li
ORDINANCE
DEVELOPMENT
UN SCHEDULED
SURVEILLANCE
I
DEMAND
MONITORING
SCHEDULED
MONITORING
i
ENFORCEMENT
MONITORING FEEDBACK SYSTEM
FIGURE D-l
D-2
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Development of a Data Base
NPDES permits issued to.POTW's often stipulate that the
permittee must promulgate an enforceable ordinance. In
addition, the permittee is required to submit reports and
forms to the EPA regional office concerning the character-
istics of contributions from major contributing industries
(MCI1s)within their system. Once an ordinance is in effect,
reports on the progress of the MCI's toward compliance
are usually required. The ordinance cannot be completely
developed unless the municipality or authority has acquired
preliminary information on non-residential contributions in
the system. The mechanism for obtaining this data base is
provided by the requirement in the typical NPDES permit
that the permittee must submit, for each MCI within its
system, an EPA Standard Form A - Municipal; Section IV
entitled "Industrial Waste Contribution to Municipal Systems."
Completion of the Section IV form requires information on
production, wastewater flow and wastewater concentration.
This information can serve as an initial data base, from which
the municipality or authority can plan or implement its
industrial pollutant control program. The Section IV form is
only required by EPA for MCI's. However, this form provides a
convenient tool that could be utilized by municipalities to
obtain data on all industrial establishments within their juris-
diction. Consequently, a systematic approach to obtaining
Section IV information should be developed. An important
preliminary step in this regard is the location, evaluation
and classification of non-residential contributors. In order
to develop the Section IV data base, two specific tasks must
be completed; the identification of non-residential contrib-
utors, and differentiating between major and minor sources.
For the small municipality, identifying contributors
within the wastewater collection system is usually an easy
task. The plant operator, or the system's superintendent,
is generally familiar with the area served, and the contribu-
tors within it. For larger systems, and those small systems
where this familiarity does not exist, identifying industrial
contributors can be more complex. The location of wastewater
sources can be accomplished by using the various listings of
commercial establishments that are available to the public.
Such listings include:
Labor Department Records
Property Tax Records
Chamber of Commerce Rosters
Census Bureau Records
Local Telephone Directory
Water Consumption Records
D-3
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These documents can provide a variety of information on
industrial establishments, such as location, product line,
production volume and water usage.
Combining the information that can be obtained_from the
individual listings can provide the municipality with an
understanding of which contributors may be considered major
or minor. Using the criteria for an MCI established by the
EPA, a preliminary breakdown between major and minor con-
tributors generally can be established on the basis of flow.
In addition to the Federal definition of a major industry,
the municipality must decide, on the basis of specific factors
in the POTW system, which industrial facilities to consider
significant contributors. The EPA definition of an MCI should
be used as a first step in a major-minor delineation. However,
other factors including water quality standards, and the POTWs
sensitivity to a particular type of wastewater, must also be
taken into account. Establishing a list of significant con-
tributing industries on this basis requires direct contact with
industry, and detailed analysis or evaluation of each plant's
wastewater.
Once a preliminary list of possible MCI's and other signi-
ficant industries has been developed, each major contributor
should be classified into the proper Standard Industrial
Category (SIC). This may be accomplished by matching the
industry's products or commercial activities to the SIC codes
as listed in the Standard Industrial Classification Manual
published by the Executive Office of the President; Office of
Management and Budget. Depending on the size and resources
of the municipality or authority, the MCI's might be required
to self-monitor their effluent to provide the Section IV
analytical information. If the municipality has the resources,
it may elect to do analytical surveys on its own. Once the
Section IV reports have been completed, the municipality can
then use this information as a data base for the development
of ordinance stipulations, including compliance requirements
and user charge fee schedules.
Scheduled Monitoring
Scheduled monitoring involves the systematic sampling
and inspection of significant industrial contributors to the
POTW system in accordance with a predetermined schedule. The
schedule should be developed by the POTW personnel administer-
ing the industrial pollutant control program, and should be
maintained as confidential information so that the industries
in the system are unaware of contemplated monitoring visits
well in advance of their occurrence. Notification is necessary,
however, prior to the visit when the sampling point is located
on plant property, to arrange for required utilities and proper
access to sampling areas. The schedule should attempt to
D-4
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provide for the monitoring of each significant industrial con-
tributor at least once per year if at all possible. If
resources do not permit this type of coverage, then visits
should be planned as often as possible within the limitations
of available resources.
Scheduled monitoring should serve a number of specific
needs, including: (1) checking for compliance with the ord-
inance, (2) user charge and industrial cost recovery deter-
minations, and (3) completion of required EPA reports.
Scheduled compliance monitoring should be aimed at obtaining
all the information necessary to determine adherence to the
local ordinance. The information required for user charge
and capital cost recovery coincides to a large degree with
the data necessary for the completion of required EPA reports.
In addition to the Section IV forms, many NPDES permits
require the municipality to furnish the EPA with periodic
reports on the progress of industrial contributors toward
compliance with pretreatment regulations. Also, if the POTW
is the recipient of Federal construction grant funds, it is
required by Federal regulations to review user charges on an
annual basis. This review would usually require that the
municipality monitor the quality and quantity of major indus-
trial contributors. Even if the municipality has not been
granted Federal funds, a periodic review of user charge fees
is usually needed to keep abreast of changing conditions in
the system.
The three elements of scheduled monitoring outlined
above (compliance, user charge and EPA reports), although
designed to meet differing needs, all require a similar field
effort and technique. All three should be conducted on a
reasonably rigorous basis to assure the validity of the data
obtained. Each element of scheduled monitoring should provide
for a single visit to a specific industrial facility for the
duration of time necessary to obtain all data required for
the purposed indicated above.
In general, scheduled monitoring would include on-site
inspection of pretreatment facilities and plant operations,
and composite samples and flow measurements taken over a
period of several days. On-site inspection is necessary to
insure that pretreatment facilities are being operated
properly and to detect any dilution of plant wastewaters.
The determination of flow is important for several reasons.
Primarily, flow information is essential in the calculation
of user charge fees. Additionally, flow readings are neces-
sary as an added safeguard against dilution and to confirm
D-5
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the validity of concentration measurements taken for ordi-
nance compliance. The degree of care and conformance to
established procedures in obtaining samples and flow measure-
ments during scheduled monitoring visits is an extremely
important consideration. Information obtained during this
process may ultimately be used in enforcement activities cul-
minating in court action. Additionally, in the determination
of user charges, the municipality may be compelled to monitor
with sufficient rigor to satisfy the industry that the infor-
mation obtained is sufficiently accurate. This situation is
especially valid in those cases where sewer use charges are a
significant expense for the industry.
Although detailed composite sampling may be most desirable
for compliance monitoring, simple grab samples may often be^
sufficient to determine ordinance compliance. It is recognized
that many POTW systems do not have sufficient resources to
monitor each significant contributing industry once per year
for a period of several days. The essential aspect is to
obtain a sample that will have sufficient validity should it
become necessary to use the data for enforcement activities.
The applicability of less rigorous sampling, such as simple
grab samples, depends largely on the stipulations of the
ordinance concerning sampling technique and the municipality's
ability to enforce the ordinance using the data derived from
a grab sample.
Unscheduled Surveillance
In addition to the planned approach, POTWs should institute
a less formal type of compliance monitoring designed to provide
a spot check of industrial contributors. This random type of
compliance monitoring should be focused on maintaining a degree
of surveillance, and would generally not be formally planned
by the POTW.
Scheduled compliance monitoring is designed primarily to
establish the characteristics of contributions from major
sources, whereas unscheduled surveillance attempts to randomly
survey all sources within the system. By checking all con-
tributors over an extended period of time, the municipality
can continue to expand its data base, and keep abreast of
trends and changes within the system. This type of monitor-
ing should be conducted on a random basis, with contributors
being observed during normal operation, thus providing infor-
mation on the true nature of the wastewater. If ordinance
violations are suspected, the information obtained during
unscheduled surveillance can also be used to evaluate the
need for further, more detailed, evaluation oi" a particular
contributor.
D-6
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Unscheduled surveillance can be conducted with less
rigor than scheduled compliance monitoring. Since sur-
veillance activities are intended only to provide a quick
spot check to determine the need for future more detailed
analysis and evaluation, this type of monitoring can be
less formal than a full compliance monitoring visit.
Unscheduled surveillance should involve no more than a few
samples, perhaps composited over a short period of time,
and a cursory inspection of plant operations and pretreatment
activities. Where resources are limited, grab samples are
frequently used for this type of surveillance. Flow measure-
ments should be taken if facilities are available to obtain
readings without difficulty.
Demand Monitoring
As the name implies, demand monitoring should be conducted
when an upset or other disruption of system operation occurs,
which may have been caused by an industrial source. Additionally,
any discharge of prohibited or limited materials can prompt
demand monitoring. Specific occurrences that may initiate a
demand monitoring sequence are as follows:
1. Contributions of Explosive or Corrosive
Materials to the Sewer
Release of these types of materials are generally pro-
hibited by the municipal ordinance. Because of the magnitude
and immediacy of the potential impact of explosive or corro-
sive materials, swift location of the source is essential.
The most effective means of locating sources of explosive
or corrosive materials is by utilizing sewer back tracking,
which is a systematic search upstream through the sewer
system until the source is pinpointed.
2. Operating Difficulties
Treatment plant and collection system operating diffi-
culties can also prompt demand monitoring. One of the more
serious operating problems is caused by the release of mat-
erials into sewers which can cause blockages or plugging.
Similarly, excessive quantities of viscous or floating solids
entering a treatment plant can disrupt unit operations such
as sludge digestion. The presence of excessive foaming can
also cause operating difficulties, and may prompt a demand
search. In general, any upset of normal operating routine
may be considered cause for initiating demand monitoring.
D-7
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3. Violation of thePOTW's Permit Requirements
A POTW's permit generally contains limits on the concen-
trations of specific pollutants that it can discharge to nav-
igable waters. If the treatment process is disrupted to the
extent that these limits are exceeded, it becomes the respon-
sibility of the municipality to determine the source of the
materials that might be passing through the system, or caus-
ing poor removal of the pollutants that the treatment system
is designed to remove.
4. Violation of Pretreatment Regulations
Since many NPDES permits require the development of an
ordinance that contains requirements for compliance by MCI's
to pretreatment regulations, a suspected violation of these
standards can initiate demand monitoring. In such cases,
demand monitoring should provide information on the cause
of interferences, and the responsible party. In these sit-^
uations, demand monitoring can be most successful when the
municipality has access to a good data base. Using data
base information, the probable sources of interfering mat-
erials can generally be determined and monitored so that
responsibility can be properly assigned.
It should be noted that in those cases where demand
monitoring is prompted by the presence of an explosive mat-
erial, the removal of the explosion hazard must have top
priority. It is unwise to attempt sewer backtracking until
any possible danger has been eliminated.
Self-Monitoring
Many of the monitoring activities that have been out-
lined in the preceding paragraphs require that samples be
taken at the effluent of an industrial contributor, and
analyzed for appropriate pollutant parameters. Depending
on the available resources and manpower, the municipality
may not be able to perform all of the various monitoring
functions required for industrial contributors. At a min-
imum, the municipality should attempt to conduct r with
their own personnel, compliance and demand monitoring
activities for ail significant industrial cor.tri utors within
the system. However, complete coverage of all contributors
within the system may be more difficult to implement using
municipal personnel and resources. One way to circumvent
this problem is to require each major contributor to do its
own sampling and analysis, a function which is usually termed
self-monitoring.
D-8
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Self-monitoring systems require that a. mechanism for
reporting and record-keeping be maintained by the industrial
establishment. Periodic reports would generally be sent
directly to the municipality. The recordkeeping function
permits access to a history of source quantity and quality
which can aid in both data base development and compliance
determination.
Self-monitoring can be particularly helpful in the
development of the initial data base. Forms can be forwarded
to industrial contributors requesting information on the flow
and pollutant characteristics of their effluents. This type of
approach is most applicable where a local permit program is
utilized, and the form then becomes a permit applicaton. Data
accumulated in this manner can serve as the basis for estab-
lishment of an industrial pollutant control program, with
verification achieved through subsequent compliance monitoring.
Enforcement
An important function of a monitoring program is its
ability to provide specific information required by enforce-
ment activities. Enforcement implies that there has been a
violation of a regulation. In general, municipalities will
use monitoring information to assess deviations from ordinance
stipulations. If conducted with the proper rigor and quality
control, wastewater sampling and analysis previously performed
by the municipality can be used in enforcement activities
directed at ordinance violators. Self-monitoring information
generally is not used for enforcement. If an industry is
aware that its contribution is in violation of the ordinance,
it is not likely that it would be willing to submit such data
to the municipality for use in enforcement proceedings. There-
fore, self-monitoring data should not be considered suitable
for enforcement activities. Instead, the municipality should
rely on its own monitoring information, legally obtained, with
proper technical execution.
Field Considerations in Monitoring
Background
Organizational and managerial aspects of a monitoring
program may vary considerably from system to system, but the
approach to the technical problems encountered in any field
monitoring activities remain fairly constant. The need to
maintain rigor and objectivity dictates that sound, uniform
D-9
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and well defined procedures be maintained during plant inves-
tigations and sampling programs. Some guidance on how to
develop and carry out a monitoring program is available in
an EPA Technology Transfer document entitled "Handbook for
Monitoring Industrial Wastewater." This handbook describes
technical aspects of monitoring, but its major emphasis is
directed at industries discharging directly to navigable
waters that are engaged in self-monitoring activities.
Although many of the details remain the same, field consider-
ations for monitoring industrial contributors in a pretreat-
ment situation have a slightly different orientation. Special
field considerations for monitoring pollutants introduced into
POTW's are outlined in this section.
An ordinance will generally prohibit, or set limits on
the release of specific materials to the municipal wastewater
treatment system. Wastes that cause an explosion hazard, or
block or corrode the sewer are generally completely prohibited.
Other pollutants that may either inhibit biological processes,
or pass through the system, may be limited by ordinance. It
is therefore essential that the monitoring program supply data
on the contributions of prohibited and limited substances as
stipulated in the ordinance. Furthermore, the ordinance may
establish the frequencies and the type of sampling required
for non-residential contributors. Monitoring activities must
also be coordinated with these aspects of the ordinance.
The approach to monitoring in the field subdivides into
three basic categories: (1) Monitoring on a scheduled and
planned basis, (2) Unscheduled surveillance on a random
basis, and (3) Demand monitoring prompted by an emergency
condition or violation of standards. Field considerations
in plant sampling during a planned visit or random visit for
unscheduled surveillance are similar in many respects,
although less rigor is required during an unscheduled visit.
Consequently, details on the field aspects of monitoring
have only been provided for scheduled and demand monitoring,
since the information provided under scheduled monitoring
may generally be used as a guide for unscheduled surveillance.
Scheduled Monitoring
Scheduling
An attempt should be made to systematically cover all
significant contributing industries annually if resources
permit. After initial data base development, monitoring should
be conducted at each major contributor to determine progress
toward compliance. Once compliance is achieved, the contributor
D-10
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must be sampled periodically to assess continued compliance.
Additionally, when a scheduled compliance monitoring visit
uncovers a violation, scheduling should be altered to provide
more detailed analysis of the wastewater. This extended
sampling program is normally required to obtain data suffi-
ciently valid for enforcement activities.
In all cases, the frequency and order of investigations
should be determined on the basis of size and importance of
the contributor. Sampling should be started with the largest,
or most significant industry. Once the major industries are
covered for data base and initial compliance purposes, a
continuing program of follow-up monitoring should be instituted.
It may not be within the resources of the municipality to
cover all contributors within its system thoroughly and equally.
A schedule in which major contributors are monitored more
frequently than minor contributors will generally be necessary.
Preparation for a Monitoring Visit
Industries should not be notified well in advance of
scheduled monitoring or unscheduled surveillance visits. It
is generally agreed that by not giving prior notice to the
industry, the samples that are obtained will be mo-re represen-
tative of daily operation. Nevertheless, notification just
prior to the visit is necessary when the sampling point is
located on plant property, to allow for necessary utility and
access arrangements by plant personnel.
Prior to sampling at a contributor, the sampling crew or
inspector should obtain specific information about the indus-
try. During the initial visit a plant inspection report should
be prepared. Several specific items should be included in this
report:
A sketch of the location of all wastewater effluent
lines that flow into the publicly owned sewer
system. The sketch should also include the layout
of major plant features.
A description of major product lines and processes
utilized within the plant. For MCI's this informa-
tion may be obtained from the Section IV report.
A detailed description and appropriate sketches of
existing pretreatment facilities, including operating
data if available.
A list of pollutants of interest at the plant, with
emphasis on materials limited or prohibited by the
ordinance.
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Equipment
On-site inspection, flow measurement and sampling should
be accomplished during each visit. Accurate flow measurement
and sampling techniques are of prime importance in obtaining
valid monitoring information. Both flow measurements and sampl-
ing can be accomplished either manually or through the use of
automatic devices. Three types of sampling may be utilized:
Grab samples, in which a single volume of wastewater
is obtained and analyzed. This type of sample will
not always provide an accurate measure of wastewater
characteristics, especially when the flow is heter-
ogeneous, or varies with time.
Simple composite sampling is a timed sequential
collection of equal volume grab samples that are
combined in a single reservoir. This type of
sample can give a partial evaluation of the
variability of wastewater composition with time.
It does not provide any measure of the total
pounds of pollutant discharged since pollutant
loading is a flow related value.
Flow proportioned composite samples are obtained by
collecting incremental samples with volumes propor-
tional to flow. This type of sample, when analyzed
and compared to total flow,provides the most
accurate measure of wastewater quality and pollutant
loading.
Automatic sampling devices that can obtain all three
sampling types are commercially available. These automatic
samplers vary over a wide range in cost, applicability and
reliability. Two EPA documents are available which provide
thorough evaluation of commercial automatic samplers:
"Sampling of Wastewater," by Philip E. Shelley
Available through EPA Technology Transfer
"Wastewater Sampling Methodologies and Flow
Measurement Techniques"
EPA Report 907/9-74-005
The second document also includes information on the
performance of portable automatic flow measuring devices.
There are considerably fewer devices of this type on the
market than automatic samplers. However, a few portable
instruments are available that can provide reasonably
accurate flow measurement data.
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For the smaller sys -m, or those municipalities that
have only limited resources, both sampling and flow measure-
ment may be accomplished using manual techniques. All three
sample types can be collected using manual methods. In gen-
eral, there is little equipment commercially available for
manual sampling. What is usually needed is an extendable
pole, with a stoppered bottle attached to the end. This
type of sampling pole can be easily fabricated. The sample
bottle should be hinged so that it can be tilted to align
parallel to the wastewater flow. This orientation allows
for sampling from very shallow streams. The bottle stopper
should be attached to a string so that it can be removed
while the sample bottle is submerged.
With regard to flow determination, the accuracy of any
flow measurement depends greatly on the control surface utilized.
Some ordinances may require that major contributors install a
special control manhole designed to provide sufficient access
for sampling and an appropriate control surface for flow
measurement. Depending on the situation, permanent flow
recording equipment may also be required. The installation
of a standard weir or flume makes flow measurement a simple
matter of measuring wastewater depth. No control surface is
completely accurate, but the combined use of a quality auto-
matic flow mesuring device and a control surface can typically
yield flow measurement accuracy of better than +_ 15%.
Special attention should be paid to the accuracy of
sampling activities. Whereas flow measurement accuracy can
be held to the 15% level, sampling errors can range up to
200% of the true value. The basic problem results from the
fact that the typical industrial waste may have a large pro-
portion of its pollutants in the form of suspended solids.
As a result, it is important that the quantity of suspended
solids entrained during sampling be proportional to the sus-
pended solid content of the total wastewater stream. Common
practice is to simply place a suction tube in the wastewater
flow, or to immerse an open sampling bottle in the stream.
Since solids entrainment is a velocity controlled process,
an attempt should be made to obtain samples isokinetically.
There should be a. minimum fluid velocity difference between
the interior and exterior of the sampling tube. Accomplish-
ing this type of sampling is a difficult procedure, but the
situation can be significantly improved by aligning the sam-
ple tube such that it is facing upstream and is secured
rigidly in place. Because of the potential for large errors
associated with sampling, it is essential that extreme care
be exercised in selecting sampling devices and procedures.
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Sample Handling
Once an accurate sample has been obtained, several steps
should be taken to assure that the validity and objectivity
of the monitoring operation is maintained. All samples must
be properly preserved. Sample preservation techniques are
outlined in various analytical handbooks such as Standard
Methods and the EPA Chemical Methods Manual. The content
of these and other similar handbooks are discussed in more
detail in the section devoted to laboratory considerations
in monitoring.
Because of the heterogeneous nature of many industrial
wastewaters, the parameters to be analyzed may require the
use of incompatible stabilizing reagents. To solve this
problem, it is usually necessary to take a relatively large
volume of sample, so that it may be divided for appropriate
preservation. In addition to assuring adequate volume for
sample preservation, sufficient sample size must be maintained
so that a portion of the sample can be offered to the indus-
trial contributor. The option should be given to the industry
of independently checking the municipality's analytical
results if they so desire.
Chain of Possession
Once an appropriate sample is obtained and properly
stabilized, it is essential that the possession of the sam-
ple be properly documented. That is, the person completing
the field sampling should maintain a log, containing pertin-
ent information such as date, time and location of the sam-
pling activity- Before releasing the sample to the labora-
tory, or any other appropriate official, a signed receipt
should be obtained documenting the exchange. As the sample
is transported, a continuous history of its condition and
locations should be maintained through successive log entries
and receipts.
The reason for such caution in the handling and transfer
of samples stems from the need to be certain of sample inte-
grity as part of any enforcement activity. It should be
assumed that every scheduled compliance monitoring sample may
become evidence in a court of law. In practice, few ordinance
violations will require legal action, but nevertheless, sample
integrity must be maintained. If the municipality cannot
prove that a sample has not been mishandled or tampered with,
then any inferences regarding the quality of the wastewater
that the sample represents fall into jeopardy. It is therefore
essential that a chain of possession be maintained and recorded,
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On-Site Safety
Visitors to industrial establishments are usually re-
quired to abide by any safety regulations observed by plant
management. ideally, access to wastewater flows should be
available from manholes or junction boxes located outside of
plant property. In this way, plant inspectors would not be
exposed to any hazardous operating activities and would be
able to sample without the need to gain entry to the plant.
Unfortunately, accessible manholes located outside of plant
boundaries are rare, and consequently inspectors are generally
required to enter upon plant property. Under these circumstances,
all pertinent safety rules in force at the plant must be adhered
to. The first step upon presenting credentials and entering
the plant, is to notify appropriate plant management, and
request applicable safety information. In most cases, a
formal set of safety rules are in effect, and these rules
should be recorded and filed with the plant inspection report.
Minimum safety equipment that must be carried by each
inspector or inspection crew includes:
Hard Hat
Safety Goggles
Rubber Gloves, Boots and Other Protective Clothing
First Aid Kit
Special safety precautions and equipment are necessary for
any sampling activity that requires manhole entry. The
most dangerous aspect of sewer sampling and inspection is
the possible presence of dangerous gases in sewers. These
gases may include either explosive vapors or poisonous mix-
tures. Conversely, there may be an oxygen deficiency in
the sewer. In order to avoid possible injury, several pre-
cautions should be taken and proper equipment should be util-
ized during the course of sewer inspection as follows:
Manholes should be opened with a hook rather than
a pry bar. Using a hook reduces the possibility
of having metal rub against metal, causing a
spark and possible explosion.
Before entering a manhole, the atmosphere within
the sewer should be tested for oxygen content,
explosion hazard and poisonous gases. Several
portable, probe type oxygen and explosion meters
are commercially available. Equipment of this
type should be utilized during every sewer entry.
Many types of indicating ampoules and gas
detection test kits are available which can
signal the presence of poisonous gases. A
D-15
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complete set of such test materials must be
present and utilized during each sewer inspection.
--Appropriate gas masks and breathing mask respirators
should be used whenever there is the slightest
indication of danger.
Actual entry into a manhole requires additional special
safety precautions. Although nearly all manholes are built
with ladder rungs, these rungs may have been used infrequently,
As £ result of the often corrosive atmosphere in a manhole,
it is not advisable to use sewer ladder rungs, since it is
possible that they may not be structurally sound. Descent
into a manhole should, be accomplished utilizing a portable
rigid ladder or flexible rope ladder. Even when a ladder
is used, each individual entering a manhole should be har-
nessed, with a safety rope leading to the surface. In this
way, in the event of a fall, asphyxiation or other injury,
the individual can be pulled to the surface with relative
ease.
Fire safety should always be practiced whenever within
an industrial plant or near an open manhole. No open flames
shculd be permitted, and all equipment should be explosion
proof and water resistant. Since many manholes are located
i :. fcti.fc.-ets 01 other thoroughfares, additional satety pre-
cautions shculd be taken to avoid automobile accidents and
the possibility of pedestrians falling into open manholes.
Consequently, appropriate pylons, barricades and flashing
lights should be used in the vicinity of the manholes.
Equipment Set-Up and Field Analysis
In the absence of a control manhole equipped with
brackets or ledges for mounting automatic samplers and flow
measuring devices, a method must be devised for securing and
mounting equipment. Within the boundaries of a plant some
degree of security can be assumed, but unattended sampling
points in public areas can be tempting to vandals. One solu-
tion to this type of field problem is the use of a self-
contained trailer or van outfitted with appropriate materials
and equipment. A further advantage to using a monitoring
vehicle is that the time required for set-up and removal of
equipment is greatly reduced. Furthermore, the vehicle can
be outfitted with appropriate field analytical equipment.
Certain parameters require immediate analysis upon sampling,
such as dissolved oxygen and pH. Equipment for these analy-
yses can be mounted in the vehicle to facilitate rapid
analysis.
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For the small system, resources may not be available,
nor the need apparent, for a sophisticated well equipped
monitoring vehicle. At the very least, a compact package
containing necessary equipment should be utilized. A mini-
mum number of separate equipment packages should be main-
tained, with the dimensions of a foot locker being an ideal
size for each equipment carrier.
Continuous On-Line Monitoring
In recent years, equipment has been developed which can
automatically monitor various wastewater characteristics.
For industrial wastewaters, numerous constituents may be of
interest. However, as a result of operating difficulties,
generally only a few parameters can be successfully analyzed
on a continuous basis. The sensors typically used in auto-
matic monitoring equipment are often very sensitive to inter-
ferences found in wastewater, and as a consequence great care
should be exercised in choosing this type of specialized
equipment. Because of the commonly encountered operating
difficulties, continuous on-line monitors generally require
a high level of maintenance and attention. If the equipment
works well, it can serve as an excellent source of continuous
data which wiTl not only aid in wastewater and process opera-
tion evaluations, but through the use of auto punching can
also reduce the amount of manual handling of data. Various
manufacturers offer continuous on-line analyticaT equipment
which can provide excellent monitoring information. However,
it should be noted that automatic analysis is still a develop-
ing technology, which should be approached with an appropriate
degree of caution.
Demand Monitoring
Unlike scheduled monitoring in which a planned and orderly
approach can be maintained, demand monitoring results from
emergency conditions occurring on a random basis. As outlined
under the functions of a monitoring program, specific emergency
conditions can prompt a demand monitoring sequence. These
situations include:
Explosion Hazard
Slugs of Inhibitory Materials
Plant Upsets
Sewer Blockages
Violations of the POTW's NPDES Permit
Any danger to public health or safety
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For demand monitoring, rapid initial detection and prompt
location of the violator are essential. To facilitate detec-
tion it is advisable where possible that permanent continuous
surveillance stations be established at key points throughout
the collection system. As soon as an abnormal wastewater
quality or flow rate is detected, either at the treatment
plant or at some point in the collection system, an immediate
investigation should be initiated. This investigation should
be systematic, back tracking in the sewer until the source of
the violation is located.
As a result of the transient nature of many violations,
it is essential that analytical work done in the course of
sewer back tracking be completed rapidly. Presence of a
prohibited or limited material in a trunk sewer cannot be
used as evidence that a specific industry is the source of
the problem. As a result, it is advisable to use quick spot-
check methods during back tracking operations. The object of
the procedure is to isolate the pollutant in question in a
lateral sewer in which a particular industry is the only
contributor. Once the source of the problem is located, then
rigorous analytical techniques should be utilized to facili-
tate possible enforcement activities.
Laboratory Considerations in Monitoring
Once an administrative approach, and technical method-
ology are developed for obtaining industrial wastewater sam-
ples, a mechanism for accurate and rapid analysis of the
samples must be provided. It is essential that analytical
results be accurate and reproducible to assure that monitor-
ing activities will provide the quality of information neces-
sary for a successful industrial pollutant control program.
Standard Analytical Techniques
Precise and well recognized techniques have been estab-
lished for the analysis of wastewaters. EPA has promulgated
rules and regulations on this subject entitled "Guidelines
Establishing Test Procedures for Analysis of Pollutants,"
dated October 15, 1973 with a proposed revision dated Decem-
ber 1, 1976 (Appendix 3). These rules stipulate specific
analytical methods that are recommended by EPA for the deter-
mination of 115 chemical and biological parameters as reported
in three analytical handbooks. The three referenced manuals
are:
"Manual of Methods for Chemical Analysis of Water
and Wastes " available through EPA Technology
Transfer
D-18
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"Standard Methods for the Examination of
Water and Wastewater," published by the
American Public Health Association
"Annual Book of Standards, Part 31, Water,
Atmospheric Analysis, 1975," published by
the American Society for Testing and
Materials (ASTM)
Each of these documents provides a short synopsis of the
analytical method for each parameter, information on inter-
fering substances, and step-by-step instructions on how to
carry out the analysis. Also included is information on the
calculation of results, the precision and accuracy of the
analytical method, and techniques for chemically stabilizing
and preserving samples.
These three publications should be considered a minimum
requirement for any analytical laboratory. These manuals
and handbooks supply the basic information that a trained lab
technician would need to successfully perform nearly all
analytical procedures that may be required in connection with
monitoring programs.
Analytical Quality Control
The potential errors encountered during analysis of
wastewater samples, although not as great as the errors
associated with poor sampling techniques, can nevertheless
have a great impact on the acceptability of monitoring
information. Without the aid of independent checks and gen-
eral quality control, the lab technician can report erroneous
results without being aware that a problem exists.
Analytical quality control assistance is available in
several forms from EPA. A document entitled "Handbook for
Analytical Quality Control in Water and Wastewater Laborato:-
ries," has been published by the EPA Technology Transfer
Program. In this handbook, specific information is provided
that can guide the lab technician or chemist toward sound
and reliable techniques and procedures. In addition, stan-
dard approaches to data handling and reporting, and informa-
tion on calibrating equipment are included.
The EPA "Manual of Methods for Chemical Analysis of
Water and Wastes" also includes information pertinent to
laboratory quality control. Each of the ten EPA regional
offices has an office of Analytical Quality Control headed
by a Regional Analytical Quality Control Coordinator.
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Included in the EPA Methods Manual are a listing of the ten
Quality Control Coordinators, accompanied by appropriate
addresses and telephone numbers. Through the Quality Control
Coordinators, any interested party can obtain preanalyzed
samples that can be used to test the accuracy of analytical
techniques. Periodic analysis of known samples can provide
the lab technician with an independent check of his
accuracy, providing the opportunity to correct any improper
procedures.
Equipment
A document entitled "Estimating Laboratory Needs for
Municipal Wastewater Treatment Facilities" published by the
Operation and Maintenance Program of the EPA Office of Water
Program Operations, provides specific information on the^min-
imum requirements for laboratory facilities at various sized
wastewater treatment plants. This publication also includes
recommendations on how a laboratory operation may be altered
to handle the analysis of pollutants contributed by non-
residential sources.
Laboratory equipment required for a municipal wastewater
treatment plant is generally standard, with variations
occurring only in degree, as the size of the plant varies.
If, however, a publicly owned system receives wastewater from
a particular industry, specialized analytical equipment may
be required. The range of applicability of several special
types of equipment are discussed in the following paragraphs.
Atomic Absorption
Atomic absorption spectrophotometry provides a rapid and
easily performed technique for the analysis of metals in
wastewater. Nearly all of the more than thirty elements that
can be analyzed by atomic absorption, can be analyzed by
standard wet chemical techniques. However, the wet chemical
methods can be tedious and time consuming, requiring detailed
sample pretreatment procedures. Atomic absorption methods
provide for metal analyses with minimum sample preparation
and, in many instances, analyses can be completed to the
parts per billion level, which is not attainable with standard
wet chemical techniques.
In some respects atomic absorption does have limitations.
In all cases, atomic absorption provides only the total con-
centration of the element. Unless specialized pretreatment
is utilized, no breakdown of oxidation state or ionic species
can be determined. However, for the analysis of metals at
very low concentrations, atomic absorption is unsurpassed in
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speed and accuracy. In situations where a large number of
metal analyses may be necessary, such as those POTWs that
receive wastewaters from metal processing or finishing indus-
tries, atomic absorption capabilities may be required. But
in all cases, the relatively high cost of atomic absorption
equipment should be weighed against the need for high volume
trace metal analysis.
Specific Ion Electrodes
Specific ion electrodes are sensing probes that can
detect the concentration of chemical species when immersed
in a solution containing the substance to be measured. As
long as the probe is completely submerged, a concentration
can be measured regardless of the volume of sample present.
In contrast to atomic absorption, specific ion electrodes,
as the name implies, detect only certain ionic species as
they exist in solution. As a consequence, specific ion
electrode readings are greatly dependent on the environmental
conditions within the sample, such as pH and oxidation-r-
eduction potential.
More than two dozen ionic species can be analyzed using
specific ion electrodes. Analyses are rapid, but require
some pretreatment to remove interferences prior to simple
immersion of the probe in the sample and meter readout. The
drawbacks to this type of specialized equipment include
possible fouling of the probe membrane, long readout equili-
brium periods and the ability to detect only specific ionic
species. However, progress is continually being made in ion
sensing electrode technology. Excellent use has been made of
the commercially available dissolved oxygen probes for
measuring oxygen demand, and an ammonia sensing electrode
has been successfully used for monitoring nitrification in
an activated sludge treatment plant. Because of the potential
ease and speed of analysis that can be realized with specific
ion electrodes, consideration should be given to the possible
use of these methods for selected ionic species.
Automatic Analyzers
A few manufacturers currently market automated wet chem-
ical analyzers that are typically called automatic analyzers.
These devices automatically draw a small sample, add pretreat-
ment chemicals, filter the sample if necessary, add chemicals
to develop a color with an intensity proportional to the con-
centration, and finally automatically read and record the con-
D-21
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centration proportional to the developed color. Other more
sophisticated automatic analyzers may use infrared or ultraviolet
spectrophotometric detection, and some use fluorometers or
flame photometers. In effect, the typical automatic analyzer
eliminates the steps that a technician would have to perform in
carrying out typical wet chemical analysis.
Although an automatic analyzer can greatly reduce the time
required to perform a particular analysis, use of_these
instruments is only economical when the analysis is required
on a mass production basis. Furthermore, automatic analysis
instruments are relatively complex devices that can require a
substantial maintenance effort. As indicated for the other
specialized equipment described in this section, automatic
analyzers should only be used when the presence of a specific
pollutant contributed by a particular industrial source is
so important that frequent analyses are required.
Gas Chromatography
Gas Chromatography refers to several variations of a
technique in which a wastewater sample is vaporized, and the
organic fraction is then analyzed. Gas Chromatography is by
far the most efficient way of analyzing for trace organics
in wastewater, especially pesticides. However, most gas
chromatographs are relatively expensive and require highly
skilled operators. As a result, this type of equipment finds
only limited application in POTW analytical laboratories.
IR-UV Spectrophotometry
Infrared (IR) and ultraviolet (UV) spectrophotometers,
like gas chromatographs are used to analyze for organic mat-
erials in wastewater. UV Spectrophotometry has been used
recently for detecting oil and grease in wastewater samples.
However, these two types of specialized equipment generally
have only limited and specialized uses because of cost and
the requirement for skilled operators.
Personnel and Degree of Expertise
Laboratory manpower requirements are outlined in the
Operation and Maintenance Program document "Estimating
Laboratory Needs for Municipal Wastewater Treatment Facili-
ties." Some quantitative information is provided for deter-
mining how laboratory manpower should be altered to handle
non-residential contributions. Although a thorough general
analysis is provided in the publication, it should be noted
that each system presents a unique situation. Nevertheless,
it can be stated in general terms, that any monitoring pro-
gram will require an added degree of laboratory support.
For very small systems with few industrial contributors, the
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additional analytical work can probably be handled by the
technician performing regular sanitary chemistry. Larger
systems may require the addition of personnel to handle the
greater load created by the industrial monitoring program.
If analyses in connection with the monitoring program
require the use of any of the specialized analytical equip-
ment outlined above, technicians or chemists with more than the
usual level of expertise may be required. Although the
utilization of specific ion electrodes is relatively simple,
proper use of atomic absorption, automatic analyzers, gas chroma-
tographs or IR-UV spectrophotometers does require a higher
degree of expertise. Automatic analyzers and atomic absorption
require good technique, and special attention to equipment
maintenance. In order to properly utilize either gas chro-
matography or IR-UV spectrophotometry, special technical
expertise beyond the 4-year college level may be required.
Special Analytical Considerations
Underlying the compliance and enforcement uses of anal-
ytical data is the need to know the true composition of
wastewater contributions so that the presence of harmful
materials can be detected. In general, EPA recommends that
wastewater samples be stabilized in a manner that will sol-
ubilizeotherwise insoluble, or suspended materials. This
is an especially important factor in the case of metals which
are generally insoluble at high pH levels. Metal concentrations
are of particular interest to plant operators since relatively
small quantities of these materials can cause operating prob-
lems. However, the metallic pollutant generally must be in
solution before it can cause an upset of biological treatment
processes. As a result, the practice of acidifying samples
and obtaining total, rather than dissolved metal concentrations
can give misleading results for samples with high pH levels.
Metallic pollutants at high pH values would tend to be in the
form of suspended solids, and would most likely be substantially
removed prior to reaching biological treatment facilities.
Consequently, the impact of a wastewater stream can greatly
depend on the pH of the wastewater as it enters the treatment
system.
Another similar example is the importance of the oxida-
tion state of the constituent being measured. For example,
hexavalent chromium is generally considered to have a greater
impact on biological treatment processes than trivalent
chromium. The impact of hexavalent chromium can be signifi-
cant, but the typical environment in a sewer system would tend
to reduce this material, and often ensure that only trivalent
chromium reaches the treatment plant. Clearly, the analysis
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of wastewaters containing materials having various impacts
which depend on the conditions in the sample, must be approached
prudently, considering the state of the pollutant as it enters
the treatment system.
Correlation of Analytical Techniques
In determining compatible pollutant loadings, it is
necessary to analyze industrial wastewater contributions for
the typical oxygen demand parameters. BOD .historically has
been used to measure oxygen demand, but this test is time
consuming and can be inaccurate. COD has been used in place
of BOD, but it too can be tedious, and it also takes a signi-
ficant amount of time to complete. In recent years, catalytic
oxidation approaches have been developed that yield measures
of oxidizable substances that can be correlated to the more
standard BOD or COD tests. These analyses, which are termed
total organic carbon (TOC) and total oxygen demand (TOD), are
rapid and reproducible.
A large body of data has been developed showing that the
more rapid TOC and TOD methods can be correlated to BOD, and
therefore can act as a more efficient measurement tool for an
operating facility. Other similar correlations can be devel-
oped that can increase the efficiency of laboratory operations.
For example, oil and grease is usually measured by an
extraction gravimetric technique. This measurement can be
simplified or accelerated by utilizing a UV spectrophotometer
to detect the levels of organics if this type of device is
available. Substitutions of methods that are either faster,
more accurate, or encompass a broader range of parameters
should be considered for unofficial use, when they can be
correlated to standard methods.
Standard Reporting Procedures
Laboratory data handling and reporting require two basic
considerations; reliable methods for recording both laboratory
and field data, and criteria for determining the significance
and acceptability of the data. Without a good system in which
standard procedures are used for accurate recording of anal-
ytical and field data, the usefulness of the information
obtained from monitoring operations can be greatly diminished.
Standard forms should be developed for recording field infor-
mation, which would include the conditions at the time of
sampling. All laboratory data should be recorded in bound
notebooks with numbered pages. This assures a continuity in
time, with a sequence for all analytical data. All forms
should be completed in duplicate, with each copy being stored
separately as a precaution against accidental loss of data.
D-24
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Of equal importance to proper recording methods is the
significance and acceptability of data collected. One must
be certain that the sample being analyzed is representative,
and has. not been influenced by infrequent or rare laboratory
or plant occurrences. Numerous statistical techniques are
available that can provide a measure of the appropriate con-
fidence that should be assigned to the data. These statis-
tical techniques are adequately covered in several of the
handbooks cited above. However, caution should be exercised
when using statistical methods. Generally, statistics offer
a means by which variations in a set of data can be analyzed,
assuming that all of the data used in the analysis is equally
valid. Although statistics can be a powerful tool, it is
always preferable to evaluate the significance of data vari-
ation on the basis of first-hand knowledge of the situation
during sampling and analysis. Many times, if unusual circum-
stances are apparent, the data can be eliminated from consid-
eration by inspection, and the problem can be rectified with-
out the use of more sophisticated statistical analysis.
Contracting for Analytical Services
Many of the considerations discussed above concerning
laboratory aspects of a monitoring program are based on the
assumption that a POTW either has an existing laboratory which
will be expanded to handle industrial wastewater, or has the
resources to develop such facilities. This may be true for
the larger systems, but the more numerous small systems may
not have the resources or capability to complete the necessary
analyses required for proper monitoring of industrial wastes.
In such systems, analytical work must frequently be performed
by commercial laboratories. When choosing a laboratory several
criteria should be considered to assure that proper services
are being provided.
At the present time only a few states have developed a
certification system for commercial laboratories. EPA is
currently in the process of developing a guidance document
for lab certification programs. As a result, for the short
term,POTW s wishing to engage qualifie'd laboratory services
will be required to evaluate laboratory performance independ-
ently. For the long term, use may be made of the upcoming
guidance to be supplied by EPA.
Several techniques can be used to compare the quality of
analytical services provided by commercial labs:
1. Use of samples spiked with known amounts of
pollutants of interest. Chemicals used in
the spiked samples can be obtained from the
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appropriate EPA Regional Quality Control
Coordinator. Use of spiked samples is a
desirable method for testing laboratory per-
formance when analyzing complex wastewater
mixtures.
2. Parallel analysis of identical samples at two
or more commercial labs. This procedure can
provide information on the relative performance
of the laboratories in question.
3. Adherence to standard procedures is essential,
and as a result should be used as a primary
criteria for evaluating lab performance.
4. Competitive costs are also important, providing
that an acceptable quality of analytical services
is provided.
Conducting ah Industrial Waste and Pretreatment Survey
EPA's Office of Research and Development has published
a case study titled "Industrial Waste and Pretreatment in
the Buffalo Municipal System" (EPA 600/2-77-018) which
includes a comprehensive description of how to organize and
conduct an industrial waste and pretreatment survey. This
document provides an excellent framework for municipalities
wishing to gain detailed information concerning the mechanics
of conducting an industrial survey. It is recommended that
the reader refer to this document for further information,
which is available by writing: General Services Administration,
Centralized Mailing Lists Services, Bldg. 41, Denver Federal
Center, Denver, CO 80225, and requesting MCD-31.
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SECTION E
POLLUTANTS WHICH INTERFERE WITH PUBLICLY
OWNED TREATMENT WORKS
Introduction
Materials Which Inhibit Biological Treatment Processes
Synergism
Antagonism
Acclimation
Significance of Data on the Inhibitory Effects of Pollutants
Inorganic Substances
Acidity, Alkalinity, pH
Ammonia
Alkali and Alkaline Earth Metals
Arsenic
Borate (and other boron species)
Cadmium
Chromium
Copper
Cyanide
Iron
Lead
Manganese
Mercury
Nickel
Silver
Sulfate
Sulfide
Zinc
Organic Substances
Alcohols
Phenols
Chlorinated Hydrocarbons
Chloroform
Carbon Tetrachloride
Methylene Chloride
Chlorobenzenes
Miscellaneous Chlorinated Hydrocarbons
Agricultural Chemicals
Organic Nitrogen Compounds
Surfactants
Miscellaneous Organic Chemicals
Oil and Grease
Discharge of Excessive Levels of Pollutants
Introduction
Impact of Excessive Discharge and Shock
Loading on POTW Operation
-------
Other Substances Which Interfere with POTW Facilities
Corrosive Materials
Materials Which Cause Sewer Blockages
Explosive and Flammable Materials
Environmental Considerations
Sludge Disposal or Utilization
Reuse of Wastewaters
-------
SECTION E
POLLUTANTS WHICH INTERFERE WITH PUBLICLY
OWNED TREATMENT WORKS
Introduction
Interference with the operation of a POTW system can be
caused by a wide variety of chemical, biological and physi-
cal phenomena. In a broad sense, interference consists not
only of materials which inhibit biological sewage treatment
processes, but also substances which cause problems in sew-
age collection systems, sludge disposal or utilization methods,
water reuse, land application of wastewater or other opera-
tions. Collection system problems include fire and explo-
sion hazards, corrosion and solid or viscous wastes which
cause plugging of sewers, and a discussion of these problems
is included herein. Interference with sludge disposal or
utilization and reuse of wastewaters consists primarily of
incompatible pollutants which are concentrated in sludge or
by reuse techniques.
This section of the report primarily presents technical
data on the various substances which inhibit biological treat-
ment processes, including the problems caused by the excessive
discharge of pollutants to a treatment facility. Consideration
was given to interference with physical-chemical sewage treat-
ment systems, employing activated carbon adsorption following
primary treatment such as chemical coagulation and filtration.
Although many facilities of this type are currently being
designed and constructed, operating data from full scale
physical-chemical plants is extremely limited at this time.
In addition, the characteristics of the activated carbon
adsorption process are such that there are few substances
which cause interference. Consequently, although it is
recognized that physical-chemical treatment facilities will
become more prevalent in the future, a detailed discussion
of interference with such processes has not been included in
these guidelines.
Materials Which Inhibit Biological Treatment Processes
In an effort to describe inhibitory effects, treatment
processes and interfering substances have been grouped into
broad categories. Three basic categories of treatment
processes have been delineated, including aerobic processes,
anaerobic processes, and nitrification. The aerobic pro-
cesses have been further subdivided into activated sludge
and trickling filter operations, while anaerobic processes
consist essentially of sludge digestion. Although many
currently operating biological treatment plants utilize the
E-l
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trickling filter process, relatively little data is available
on pollutant interferences. Consequently, the information
on aerobic biological treatment presented is predominantly
concerned with the activated sludge process. Since both
activated sludge and trickling filtration are aerobic pro-
cesses, the lack of information on trickling filtration-may
be compensated for by cautiously drawing parallels with
activated sludge data.
The general categories established for interfering sub-
stances are inorganics and organics, with acidity, alkal-
inity, pH, ammonia, transition metals, metals, sulfate and
sulfide comprising the major components of the inorganic
category. Organic substances discussed include alcohols,
amines, chlorinated hydrocarbons, pesticides and herbicides,
phenol, surfactants and miscellaneous organic chemicals.
Most analytical methods used for determing the concentra-
tions of the pollutants covered in this section yield a total
result, including the contribution of both the dissolved and
the precipitated substances in the original sample. In most
cases, a precipitated pollutant has relatively little in-
hibitory impact as compared to its soluble counterpart. This
results from the fact that most settleable solids and a por-
tion of the suspended solids are removed in primary treatment,
and therefore never reach the potentially inhibited biological
unit process. Because the insoluble fraction of a pollutant
parameter will have relatively little or no effect on biologi-
cal treatment processes, most investigators have conducted
their tests using only dissolved pollutants. As a consequence,
unless otherwise noted, the concentration of pollutants reported
in this section are only for dissolved species, not the more
common total value.
Whether a substance is inhibitory depends on a number
of factors, including its concentration and the presence of
other chemicals which have synergistic or antagonistic
effects. Some substances, such as mercury, present in waste-
water at a very low concentration, can disrupt one or more
functions of a biological treatment system. Other substances,
such as chloride ion, are inhibitory only at relatively high
concentrations. Some of the special phenomena that may alter
the inhibitory nature of a substance are outlined below as a
prelude to the detailed discussion of specific pollutants.
Synergism
Synergism can be generally characterized as an increase
in the inhibitory effect of one substance by the presence of
E-2
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another. Synergism, as well as its opposite, antagonism,
is found to be most prevalent when considering combinations
of transition metals or heavy metals. The inhibitory effects
of these metallic constituents are also enhanced by acidity.
The synergistic effects of metals with acidity is under-
standable in terms of the chemistry of these metals. The
transition and heavy metals tend to be insoluble by hydrolysis
in the pH range of sewage influent. They therefore tend to
precipitate or adsorb on solids, and interact with polyelectro-
lytes or various chemical species containing anionic functional
groups. Acidity suppresses hydrolysis, and the hydrogen ion
competes with the metal ion for adsorption sites on solids or
anionic functional groups in solution.
Another type of synergism is encountered with cyanide or
other complexing substances which are easily biodegradable.
In these cases, it is possible for the microorganism to
ingest excessive levels of complexed metal ion and then to
destroy by assimilation the complexing substance which is
shielding the microorganism from the metal ion. The result
is the release of an excessive level of the metal within the
organism, upsetting its biological life processes.
Antagonism
Antagonism is the opposite of synergism in that it is
characterized as a decrease in the inhibitory effect of one
substance by the presence of another. The most notable
antagonistic effects occur with the combination of metallic
and anionic pollutants. For example, several chelating
agents, such as EDTA (Disodium salt of ethylenediamine tetra-
acetic acid) and HEDTA (disodium salt of hydroxy-
ethylenediamene triacetic acid) have exhibited antagonistic
properties with metals. These chelating agents are used
in culturing microorganisms to regulate the level of metals
needed to grow bacterial cultures. Bacteria thrive in culture
solutions containing concentrations of these metals well into
the inhibitory range, when chelating agents are also present.
Some ambiguity as to the inhibitory effects of metals on
sludge digestion has been found in the literature. Part of
the ambiguity can be explained by the antagonistic effect of
the sulfide normally present in a digester. Sulfide ion
precipitates metals, removing them from solution and conse-
quently eliminating their inhibitory effect. In fact, this re-
duction in inhibitory effects by the addition of sulfide has
been used effectively in restoring upset digesters to opera-
tion (E-35). Besides sulfide, other ions such as hydroxide
E-3
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(i.e., high pH) chromate, ferro-cyanide, phosphate, carbonate,
and arsenate will tend to precipitate with metals, thereby
reducing the inhibitory effect.
Acclimation
In addition to chemical factors, there are significant
biological factors which must be considered to understand
the inhibitory effect of pollutants. In the activated sludge
process, a healthy biomass contains a broad distribution of
microorganisms, including many species of bacteria and protozoa,
These organisms compete for the available food, oxygen and
nutrients, and grow and reproduce according to the suit-
ability of the aquatic environment to their existence. In
the absence of sufficient food, reproduction slows and the
microorganisms devour each other. Whenever the environment
changes due to the introduction of, or omission of a given
pollutant, the opportunities for reproduction and growth of
different species change, so that the relative populations
of different species are altered with conditions.
Therefore, the previous history of a particular activated
sludge biomass, including its distribution of microorganism
populations, affects how it will respond when a new pollutant
enters its environment. When a new pollutant is introduced,
those species which cannot tolerate this substance fail to
reproduce and grow,and tend to die off, while more tolerant
species consume the food supply and grow and reproduce.
When a biomass becomes accustomed to the presence of a
normally inhibitory concentration of a substance, it can be
characterized as acclimated to that pollutant. Sludge
digestion and nitrification do not have the same flexibility
of adaptation to changing environmental conditions as do
other biological processes. Both nitrification and sludge
digestion are biological processes that rely on particular
strains of bacteria. In the case of sludge digestion, the
process proceeds in two steps,using two specific bacterial
strains to achieve digestion. Nitrification is also limited
to particular bacterial types. As a consequence, when
adverse conditions are encountered in these processes, there
is no possibility of another organism taking over for the
affected strain of bacteria. Consequently, neither nitri-
fication nor sludge digestion are readily acclimated to a
new pollutant and may be easily upset when new conditions are
encountered.
E-r-4
-------
Significance of Data on the Inhibitory Effects
of Pollutants
As a result of the chemical and biological factors which
affect the inhibitory impact of a pollutant, a given con-
centration of that pollutant may be inhibitory to a biological
process under a given set of conditions and non-inhibitory
under another set of conditions'. Therefore, it is not
surprising that a significant amount of data in the litera-
ture are apparently contradictory/ in that certain concen-
trations have been reported as inhibitory, while higher
concentrations are reported to be harmless. In most cases,
these inversions of effects with concentration are not due
to errors-of observation, but rather to different conditions
surrounding the biological processes, such as those described.
The following paragraphs summarize the current available
data on the inhibitory effects of specific substances, as
well as the chemistry and occurence of the pollutant. Where
applicable, special effects of each pollutant are described.
Important industrial sources of many of the pollutants dis-
cussed in this section are summarized in Appendix 8 of these
guidelines. Additionally, Appendix 5 contains tables summarizing
the data on the effects of inorganic, substances. Appendix 5
also contains graphical presentations of the data for inorganics.
Inorganic Substances
Wastewater entering a POTW may contain any combination
of thousands of inorganic compounds present as major or
minor constituents. Fortunately, since most inorganic sub-
stances dissolved in wastewater are present in ionic form,
it is possible to reduce the number of parameters of
interest to a smaller list of cations and anions which
comprise these dissolved substances. In addition, a few non-
ionic substances must also be considered.
The cations of interest consist of the ammonium ion and
various metal ions. A few metal ions; i.e., sodium, calcium,
and magnesium, are prevalent in wastewaters, but are not
inhibitory except at very high concentrations (about 1000
mg/1, order of magnitude). Most metal cations, on the other
hand, are beneficial or non-inhibitory at very low concen-
trations. However, at somewhat higher concentrations (a few
mg/1, order of magnitude) they become inhibitory to biological
processes.
E-5
-------
A number of metals of interest are amphoteric; that is,
they may exist in solution as a cation or anion. For example,
chromium may form chromic or chromous cations or the chro-
ma te or dichromate anion. Arsenic can likewise exist as
arsenic or arsenous cations or arsenate or arsenite anions.
Many anions (chloride or bicarbonate, for example) are
relatively compatible with biological treatment processes. _
Others, such as cyanide, borate, and chlorate can pose diffi-
culties to the biological processes. A few neutral substances
are important, especially ammonia and elemental chlorine.
The significant inorganic constituents which have been
identified as having inhibitory effects are discussed below,
in alphabetical order. A summary of the major inhibitory
effects for each inorganic pollutant is given in Table E-l.
Acidity, Alkalinity and pH
The pH of a wastewater represents the relative concen-
tration of hydrogen ions in the fluid. Although pH is fre-
quently used to describe the acidity or alkalinity of a
sample, there are fundamental differences between these con-
cepts. pH is reported on a scale of 0 to 14, with each pH
unit representing a factor of 10 in hydrogen ion concentra-
tion. A pH of 7 is considered neutral, while a solution
with a pH of less than 7 is acidic, and above 7 is alkaline.
A distinction should be made between acidity and an acidic
solution, and similarly between alkalinity and an alkaline solu-
tion. As discussed above, a pH of less than 7 indicates an acidic
solution. On the other hand, the acidity of the solution
is a measure of its capacity to maintain its pH during the
addition of an alkaline solution. For example, if an acidic
solution has a pH of 6 and the addition of one drop of an
alkali raises its pH to 9, it has less acidity than an
equal volume of another pH 6 solution that needs ten drops
of the same alkali to increase its pH to 9.
Most natural unpolluted waters have a pH value near
neutral (pH 6 to 8) . Excess carbonic acid gas (carbon
dioxide) can result in lower (more acidic) pH values, while
soluble carbonates, borates or silicates may produce higher
(more alkaline) pH values.
Most bacteria favor an environment of pH 6 to 8. Rare
ex^rfV1360163 ^ tolerate or even thrive in wastes
extremely low or extremely high pH, but these are not
E-6
-------
TABLE E-1
THRESHOLD CONCENTRATIONS OF INORGANIC POLLUTANTS
POLLUTANT
Ammonia
Arsenic
Bora te( Boron)
Cadmi urn
Calcium
Chromium
(Hexavalent)
Chromi urn
(Trivalent)
Copper
Cyanide
Iron
Lead
Manganese
Magnesium
Mercury
Nickel
Silver
Sodium
Sulfate
Sulfide
Zinc
THAT
ACTIVATED
SLUDGE
PROCESSES
480
0.1
0.05-100
10-100
2500
1-10
50
1.0
0.1-5
1000
0.1
10
0.1-5.0
1.0-2.5
5
0.08-10
ARE INHIBITORY TO BIOLOGICAL
TREATMENT PROCESSES
CONCENTRATION (mg/1)
ANAEROBIC NITRIFICATION
DIGESTION PROCESS
PROCESSES
1500
1.6
2
0.02
5-50 0.25
50-500
1.0-10 0.005-0.5
4 0.34
5
0.5
1000 50
1365
0.25
3500
500
50
5-20
REFERENCES
E-17,E-20,E-29
E-5.E-21
E-5.E-9.E-44,
E-128
E-21.E-29.E-104
E-26,E-37,E-120
E-5.E-29.E-78,
E-117.E-129
E-88
E-2,E-5,E-24,
E-78,E-100,E-109, E-129
E-5,E-15,E-21,
E-118, E-129
A-l, E-21
E-5
E-21
E-26.E-37.E-100
E-120
E-21,E-28,E-70,
E-118
E-14,E-25,E-118, E-129
E-8,E-9,E-21
E-26,E-37, E-120
E-ll.E-17
E-19.E-35
E-4,E-5,E-6,E-7,E-29
0.08-0.5
Note: Concentrations shown represent influent to
the unit processes in dissolved form.
E-33,E-78,E-100,E-1T8
E-7
-------
significant in biological treatment systems. As a result, pH
values outside this range can cause severe upsets in biological
treatment processes. This is particularly true of acidic waste-
waters with low pH values in relation to nitrification or anaerobic
sludge digestion.
Of equal importance to the absolute pH level in waste-
water is a sudden change in pH. Sudden swings of pH are
always disruptive to an otherwise stabilized system. The
effect of extreme fluctuations in pH in a waste stream can
be overcome by collecting, storing, and mixing the variable
waste mixture in a storage vessel or pond. The effluent from
this pond will show less variability and consequently will
respond to biological treatment more favorably.
Discharges of wastes from commercial manufacturing or
processing industries may typically result in wastes ranging
in pH from about 3 to 11. Wastes outside this range are
rare and represent corrosive and dangerous levels.
Acidic contributions may be received from many industrial
processes including metal cleaning, plating or treatment plants,
manufacture of drugs and explosives, processing of photographic
films, etc.
Alkaline contributions may be received from laundries,
detergent manufacture, bottle cleaners (dairies, for example),
textile processing and cement manufacturing.
Summary of Inhibitory Properties :
1. The activated sludge process can treat waste solu-
tions ranging from about pH 3 to 11, provided that the pH
level has been stabilized (E-51).
2. Another source states that inhibitory effects are
related to temperature and were noted above pH 10 at 20°C
and above pH 9 at 10 C (E-21).
3. It has been reported that at pH 4 the activated
sludge process is 43% effective (E-51).
4. The sludge digestion process is extremely sensitive
to pH, and deviations of pH outside the range 6.5 to 7.5
generally cause upset of sludge digesters.
Synergistic and Antagonistic Effects:
While high acidity (low pH) is generally inhibitory
to biological treatment systems, the presence of most metal
ions with excess acidity results in much more severe inhibi-
tory effects. The reason for this phenomenon is that at
E-8
-------
near-neutral pH values, most transition metal ions tend
to precipitate out as insoluble floes. These ions also
tend to form hydroxo-complexes at neutral or alkaline pH
values, and these complexes mask the inhibitory properties
of the. metal ions. As the pH is reduced (acidity increased),
the hydroxo-complexes are decomposed, and insoluble metal
hydrous oxide floes redissolve. The result is that the
full effect of the metal ion concentration is felt by the
microorganism. Thus, the presence of acidity which is in
itself inhibitory, causes the full release of metal ions
(copper, zinc, iron, lead, etc.) which are also inhibitory,
and a synergistic result occurs.
Conversely, alkalinity causes the neutralization of
acidity, increases the pH, and tends to precipitate metals
out of solution. Thus, alkalinity is antagonistic or decreases
the effect of metals. At high pH levels, where hydroxyl ion
is inhibitory, acidity is antagonistic to excess alkalinity.
Therefore, substances which tend to drive the pH value of
the waste toward the neutral point, tend to help the activated
sludge process to operate satisfactorily.
Ammonia
Ammonia (NH_) is a common chemical substance, which is
a gas at room temperature. It is extremely soluble in water
and its water solution is used as a household cleaning agent.
Ammonia forms a series of salts called ammonium salts.
Inasmuch as ammonia and ammonium ion occur together in
solution and are transformed from one form to another by
shifts in the solution pH, the two substances are usually
treated as a single substance in most of the wastewater
literature.
Ammonia is an important substance in wastewaters and
serves as a nutrient material to supply nitrogen needed for
microorganism growth. All ammonium salts encountered are
completely soluble in wastewater.
Ammonia occurs naturally in most wastewaters as a
result of decomposition of nitrogen containing compounds
in sanitary wastes. In addition, ammonia is used extensively
in chemical manufacture, water softening, agricultural
fertilizers, refrigeration, metal cleaning and other diverse
applications.
E-9
-------
Summary of Inhibitory Properties=
1. At low concentration levels, ammonia serves as an
important nutrient in a healthy biological oxidation system.
2. No adverse effects on oxygen consumption are noted
at concentrations of up to 100 mg/1 of ammonia.
3. At excessively high levels (about 480 mg/1) ammonia
exhibits inhibitory effects on the activated sludge process
(E-29).
4. At a concentration of 1500 to 3000 mg/1 ammonia is
inhibitory to anaerobic digestion (E-17, E-20).
Alkali and Alkaline Earth Metals
The common alkali metals, sodium and potassium, and alkaline
earths, calcium and magnesium, are widely distributed in nature
and are significant components as salts in most water supplies.
Consequently, these metals are almost universally present in
all wastewater flows, usually as chloride, sulfate or bi-
carbonate salts.
These metal ions are well tolerated by activated sludge
operations, and only at relatively high concentration levels
have inhibitory effects been noted. For example, inhibitory
effects on the activated sludge process were noted with slug
dose concentrations of sodium chloride (common table salt)
of 3Q,000 to 50,000 mg/1 CE-5, E^22, E-^49) , but these inhibi-
tions may be primarily caused by the accompanying high chloride
levels (E-91). Upsets of biological treatment processes have
been reported in which wastewater contributions containing high
chloride levels were indicated as the cause of the upset. Inter-
ference with a trickling filter was noted at 20,000 mg/1 sodium
chloride (E-22). At more moderate concentrations of salt, no
interference with these processes were noted.
However, the anaerobic sludge digestion and nitrifica-
tion processes are more sensitive to these cations, and it
appears that important effects are noted when the relative
concentrations and absolute concentrations of these metal
cations deviate from certain beneficial values. Thus, it
has been reported that calcium levels of 100 to 200 mg/1 are
stimulatory to anaerobic digestion; 2500 to 4500 mg/1 are
moderately inhibitory to the process; and a concentration
level of 8000 mg/1 is strongly inhibitory (E-26,- E-37, E-120) .
E-10
-------
Similar relations are noted for magnesium, sodium and potas-
sium. Also, it has been reported that various combinations
of alkali and alkaline earth ions and the ammonium ion show
either synergistic or antagonistic effects in the operation
of the anaerobic sludge digestion process. For nitrification
processes a magnesium concentration of 12.5 to 50 mg/1 was
found to be stimulatory, whereas 50-100 mg/1 inhibited the
process (E-100) .
Arsenic
Arsenic is a metallic element which forms cationic
salts of the arsenic and arsenous forms and anion salts of
the arsenate and arsenite forms. It is well known for the
poisonous properties of its compounds. Arsenic is found at
very low concentration levels in most natural waters and is
likewise a trace constituent in most foods.
Arsenic can enter sewage treatment systems from a number
of commercial operations. A major use of arsenic compounds
is agricultural pesticides, where it is used in liquid sprays
and dusting powders. Other uses associated with its toxic
nature are wood preservatives and medicines. Arsenic com-
pounds also find commercial use in artists' pigments, glass
manufacture, and pyrotechnics. Probably the most significant
source of arsenic pollution is from agricultural pesticide
use.
Summary of Inhibitory Properties:
1. A level of 0.1 mg/1 sodium arsenate (arsenic concen-
tration 0.04 mg/1) showed no effect on oxygen uptake, while
a level of 1.0 mg/1 of this compound depressed oxygen uptake
about 50% (E-21) .
2. A 0.1 mg/1 concentration of arsenic trichloride
(about 0.04 mg/1 arsenic) likewise reduced oxygen uptake
about 50% (E-21) .
3. A 4 mg/1 concentration of sodium arsenate (about
1.6 mg/1 arsenic) resulted in a significant reduction in
sludge digestion efficiency (E-5).
Borate (and other boron species)
Boron is a light metal. It forms a series of anionic
salts, including borate, metaborate and tetraborate. Boron
E-ll
-------
salts are found widely distributed in natural waters and
foods, and therefore are natural constituents of sewage.
In addition, boron compounds are constituents of household
detergents and medications which also contribute to boron in
domestic wastewaters. Boron compounds find application in
the manufacture of glass and ceramics, fireproofing, high
energy rocket fuels and in the operation of nuclear reactors.
Contributions of boron from these sources are probably small.
Summary of Inhibitory Properties:
1. Boron concentrations of 0.005 to 0.05 mg/1 are
reported to have had no effect on microorganism growth (E-29).
2. Levels of borate from 0.05 to 100 mg/1 have been
reported to interfere with the activated sludge process in
various ways, such as interference with sludge settling and
COD removal (E-5, E-9 , E-29, E-44) .
3. Boron shock loads of 2 mg/1 have been reported to
have affected anaerobic digestion (E-128) .
Cadmium
Cadmium is a transition metal which forms divalent salts.
Cadmium salts are somewhat toxic, and are found in domestic
water and wastewater sources only at very low levels. Con-
tributions to POTW's come from industrial or commercial sources,
with the principal contributions of cadmium coming from metal
plating processes. Cadmium also finds significant use in
pigment manufacture, photographic applications, dyeing and
calico printing.
Summary of Inhibitory Properties:
1. Cadmium has no adverse effects on the activated
sludge process up to a concentration level of about 1 mg/1
(E-21) .
2. In the range of 10 to 100 mg/1, cadmium shows var-
ious deleterious effects, such as decrease in BOD removal
efficiency and reduction in oxygen uptake (E-21, E-29).
3. An investigator reports that 0.02 mg/1 should be
considered a threshold concentration for cadmium in digesters
(E-104) . *
E-12
-------
Synergistic and Antagonistic Effects:
Synergistic effects have been reported on cadmium
and zinc, as well as cadmium and manganese. Other heavy
metals may also show Synergistic effects with cadmium.
There is no doubt that acidity would show a synergistic effect
with cadmium.
Sulfide and high pH (8 and above) are strongly antagon-
istic with cadmium, since they precipitate the insoluble
sulfide and hydroxide compounds.
Chromium
Chromium is a transition metal which forms two import-
ant series of salts, the trivalent chromic cation and the
hexavalent chromate anion. Chromium is present as a trace
constituent in domestic sewage, but the levels encountered
are not significant relative to POTW operation.
Chromium is contributed to wastewater from numerous
industrial and other commercial operations. Especially sig-
nificant sources are the electroplating and electrofinishing
industries. Another significant source is the use of soluble
chromates as corrosion inhibitors in cooling towers and in-
soluble chromates in corrosion resistant coatings. Other
sources of commercial discharge of chromium salts include
leather tanning, photographic processing, and textile dyeing.
Unless stated otherwise, the inhibitory properties outlined
below are for hexavalent chromium.
Summary of Inhibitory Properties:
1. Effect of Chromium on the Activated Sludge Process:
a. At a concentration level of 0.005 to 0.05 mg/1,
chromium has a stimulatory effect on microorganism growth
(E-5) .
b. Interference with biological processes is re-
ported at the 1 mg/1 concentration level (E-5).
c. Another investigator identifies 10 mg/1 as the
threshold level for deleterious effects (E-29, E-78).
d. In the concentration range of 1 to 50 mg/1, the
published literature is quite confusing and contradictory,
ranging from serious interference to insignificant effects
(E-29, E-118).
E-13
-------
e. In the range of 50 to 500 mg/1, the published results
describe various deleterious effects. These include syner-
gistic effects of chromium with acidity, iron and copper
(E-5, E-29, E-21, E-118).
f. Slug doses up to 500 mg/1 of chromium have been
reported to result in relatively minor disturbances to the
activated sludge process (E-29, E-12, E-36).
g. Up to 50 mg/1 of trivalent chromium was reported
to have an adverse effect on activated sludge processes (E-88).
2. Sludge Digestion
a. Chromium levels of up to 500 mg/1 in the plant
influent do not affect digestion of the resultant sludge.
This result may be due to precipitation of the insoluble
chromic hydrous oxide (E-118).
b. The addition of up to 50 mg/1 of chromium directly
to a sludge digester had a serious effect on digestion (E-78),
and the addition of 500 mg/1 to the digester stopped the
process completely (E-118).
c. The effect of trivalent chromium on digestor
operation has been reported to be dependent on the digestion
period . 500 mg/1 trivalent chromium is tolerated in digesters
with 20 day digestion periods, 100 mg/1 with 17 days of
digestion,and 50 mg/1 with 14 days (E-88).
3. Nitrification
a. It has been reported that 0.25 mg/1 of chromium
will inhibit nitrification to some extent (E-119).
b. From 2 to 5 mg/1 of chromium completely inhib-
its the nitrification process (E-29, E-117, E-13).
4. Sludge Settling
a. Concentrations ranging from 7 to 500 mg/1 of
chromium interferes with sludge settling (E-29) .
Copper
Copper is a transition metal which forms salts and
other compounds in two valence forms. Monovalent copper,
copper (I), forms a series of chemical salts called "cuprous",
E-14
-------
while divalent copper, cnpper (II),forms a series of "cupric"
compounds. The cuprous compounds are all relatively insolu-
ble and uncommon, and are not significant in water pollution
or water treatment chemistry. Therefore, in this document,
attention has been focused on cupric compounds only, and
references to "copper" below signify the cupric form only.
The majority of common copper compounds are insoluble,
and therefore do not pose a problem to sewage systems in that
form. However, copper nitrate, sulfate, chloride salts, and
a number of copper complexes are soluble and these may pose
problems when discharged to sewage treatment plants.
Copper compounds occur naturally in surface and ground
waters, usually at relatively low concentration levels, and
are natural constituents of domestic drinking water supplies.
Copper also enters domestic sewage flows as a result of rou-
tine household activities, such as washing and preparing of
foods, cleaning of copper utensils, and use of garbage dis-
posal units to macerate waste foods. In addition, copper
salts discharge to sanitary sewers as a result of corrosion
of copper and brass plumbing fixtures and pipes. Also, cor-
rosion of copper roofing and surface run-off leads to addi-
tional discharge of copper to combined sewage systems.
Finally, copper compounds are discharged from a number
of industrial operations such as metal cleaning and electro-
plating operations. Engraving, jewelry, electrical manu-
facturing, chemical industrial processes, and algicide and
insecticide uses all add copper to industrial wastewaters.
Copper is an essential nutritional food element for man
and lower organisms, and is no doubt essential to the proper
operation of biological waste treatment systems at some un-
determined trace level. At extremely high concentration
levels (about 1000 mg/1 and above) essentially all forms of
living species are destroyed and essentially sterile water
results (E-121).
The sewage plant operator is concerned with intermediate
concentration levels, at which copper-bearing wastewater may
be processed through the system without causing significant
plant upset. Above this safe copper concentration, he may be
interested in the various inhibitory effects which may
result. It is expected that the various biological treatment
systems may respond differently to the same level of copper
in wastewater.
E-15
-------
Summary of Inhibitory Properties :
1. Synergism of copper with the following substances
has been identified: cyanide, acidity (low pH) and other
heavy metals.
2. Antagonism of copper with the following substances
has been identified: sulfide, high pH, and certain chelat-
ing agents such as EDTA (E-100).
3. Effect of Copper and Copper Complexes on Activated
Sludge Plants
a. One mg/1 of copper has been reported to be the
threshold limit for continuous feed of copper to the activated
sludge process (E-5, E-2, E-109 , E-24, E-78) .
b. A pilot plant study showed an effect on the
process at 1.2 mg/1, while at 10 mg/1 a small reduction of
plant efficiency of about 4% or less was reported (E-4,
E-24, E-78, E-118).
c. The combination of 3.6 mg/1 of copper with 8.6
mg/1 of cyanide caused a serious upset of the process (E-16).
d. Another reference cites 0.1 mg/1 as the recom-
mended upper limit of copper ion in sewage feed (E-2) .
e. For slug doses, it has been reported that doses
above 50 mg/1 for 4 hours show a severe effect (E-21) ; a
64 mg/1 dose for 4 hours showed a slight effect (E-118); a
75 mg/1 dose for 4 hours "affected" the system (E-29); and
100 to 400 mg/1 showed a severe effect in which plant ef-
ficiency dropped to about 50% for 48 hours as a result of the
slug dose (E-118, E-2).
f. Ten mg/1 of copper in the presence of cyanide
caused a severe effect (E-29) , while 25 mg/1 of copper in
the presence of cyanide caused a very severe effect for
24 hours (E-118).
g. It has been reported that there is an approximate
one-to-one relationship between copper concentration and
effluent COD. A one mg/1 increase in copper will result in
a one mg/1 increase in effluent COD (E-60).
E-16
-------
Note that the severity of effects reported for slug
doses of copper does not correspond quite proportionally
with the concentrations of these doses. Nevertheless, it
may be concluded that slug doses of copper from 50 to 400
mg/1 result in serious upset conditions with the activated
sludge process.
4. Effect of Copper on Sludge Digestion
a. Data reported on the effect of continuous dos-
ages of from 0.1 to 10 mg/1 of copper in influent wastewater
on sludge digester operation vary widely.
b. Two investigators recommend 1.0 mg/1 as the
maximum concentration of copper in influent wastewater to
avoid digestor operating difficulty (E-5, E-15).
c. For direct feed to a combined sludge digestor,
a 5 mg/1 copper dosage is recommended as an upper limit. For
primary sludge digestion, 10 mg/1 copper is the recommended
upper limit (E-78).
d. Various copper concentrations in digestors greater
than 10 mg/1 have been found to be inhibitory (E-l, E-2,
E-118) .
These data may be summarized by stating that over
the range of copper concentration from 0.1 to 10 mg/1, there
are reports of digestor problems attributed to the presence
of copper, and other reports of digestor tolerance to these
same levels. These discrepancies are no doubt explicable in
terms of differences in operating conditions, and antagonistic
or synergistic effects.
5. Nitrification - One investigator reports that 0.005
to 0.03 mg/1 of copper is stimulatory to nitrifying bacteria,
concentrations above 0.05 mg/1 copper were found to be
inhibitory (E-100), and 0.5 mg/1 of copper as copper sulfate
has been reported as inhibitory to nitrification (E-2).
Cyanide
The cyanide ion (CN~) is a pollutant parameter of sig-
nificant interest in POTW influent and effluent, as well as
in rivers, streams and lakes. Its poisonous character is
universally known, and accounts for the interest in this
pollutant. The poisonous nature of cyanide is actually
associated more with hydrogen cyanide, which generally is
more prevalent below pH 7, than with the free cyanide
ion. Therefore, cyanide toxicity is directly tied
E-17
-------
to the pH of the wastewater. Another interesting aspect of
its poisonous character is that its toxicity is principally
applicable to higher life forms. Microorganisms present in
sewage treatment plants can adapt to the presence of cyanide,
and metabolize and destroy it even at fairly high concentra-
tion levels.
An important property of the cyanide ion is that it is
a powerful complexing agent and can bind with transition and
other heavy metal ions to form metal cyanide complexes.
These complexes exhibit neither the properties of the metal
ion nor the cyanide ion, and thus are actually different
chemical substances.
Cyanide is not a normal constituent of domestic sewage,
and its presence in wastewaters is almost exclusively a
result of manufacturing processes and commercial operations.
Principal sources of cyanide in wastewater are the electro-
plating, coke, petroleum gas, steel, plastics, and chemical
industries. The electroplating industry is particularly
noteworthy because it combines cyanide wastes with transi-
tion and heavy metal ion wastes.
Summary of Inhibitory Properties:
1. Wastewaters containing 0.01 to 0.05 mg/1 of cyanide
have no deleterious effect on an activated sludge plant (E-118).
At levels of from 0.3 to 3 mg/1 of cyanide, some adverse
effects are reported (E-21).
2. Recommended maximum limits of 0.1 to 2 mg/1 of cy-
anide have been reported in the literature (E-5, E-118).
3. 5 mg/1 of cyanide in raw wastewater has been found
to interfere with activated sludge processes (E-15).
4. A slug dose of 40 mg/1 of cyanide upset an activated
sludge plant for two days (E-29). On the other hand, after
acclimation, 60 mg/1 was tolerated in an activated sludge
plant (E-21) and 200 mg/1 was tolerated in a trickling filter
plant (E-29).
5. It has been reported that the toxicity of copper
and nickel are enhanced by the presence of cyanide (E-16 , E-118)
6. It was reported that cyanide levels of 4 to 100
mg/1 upset the sludge digestion process from four days to
complete retardation (E-5).
E-18
-------
7. Trickling filter operations have been impaired by
30 mg/1 of cyanide (E-7), but 10 mg/1 were destroyed by trick-
ling filter operations.
8. The nitrification process was reported to be in-
hibited by about 75% by 0.65 mg/1 of sodium cyanide (0.34
mg/1 of cyanide) (E-129). Other reports indicate that 2 to 72 mg/1
of cyanide as HCN interfered with nitrification, the upper
value completely inhibiting the process (E-5).
9. The cyanide ion shows a remarkable range of behavior
with biological processes, from interference at low concen-
trations with non-acclimated systems, to tolerance at high
levels in acclimated systems.
Iron
Iron is a transition metal forming two groups of salts,
the divalent ferrous salt series and the trivalent ferric
salt series. Both the ferrous ion and the ferric ion are
precipitated from solution at neutral pH values as hydrox-
ides .
Iron salts are natural constituents of both domestic
and commercial wastewaters. While the levels in domestic
sewage are always low, the levels in certain industrial or
commercial wastes may be excessive. Major industrial sources
include metal pickling and cleaning processes, chemical manu-
facturing, electric utilities, etc.
Summary of Inhibitory Properties:
1. Iron is a necessary element for microbiological
growth and its absence causes a reduction in metabolic
activity (E-39, E-112).
2. The activated sludge process appears to be rather
insensitive to iron concentration except for very high con-
centration levels. It is reported that 100 mg/1 causes
little adverse effect, but 1000 mg/1 stops oxygen uptake
(E-21) .
3. The sludge digestion process is more sensitive to
soluble iron concentration. It is reported that 5 mg/1 is a
maximum level, as higher iron levels cause interference with
the process, due to hydrolysis of the iron and release of
acidity (A-l). As has been previously emphasized, the sludge
digestion process is very sensitive to pH values outside the
optimum range of 6.5 to 7.5. Therefore, the inhibitory effect
E-19
-------
of iron is no doubt due to the acidity released (E-5, E-118).
4. A technique to control metal interference with sludge
digestion is to add iron sulfide directly to the digester.
Iron sulfide, although very insoluble, is more soluble than
most other metal sulfides. When a metal, e.g., copper,
enters the digestor, it reacts with the iron sulfide to pre-
cipitate the copper sulfide, and thus removes the copper
from solution. The less "toxic" iron is solubilized as a
result. If the pH is stabilized in the optimum range, the
iron is largely precipitated out as the hydroxide, and the
digester is protected from the effect of the copper. The
selection of iron sulfide for this use is a result of its
inherent low "toxicity" to microorganisms.
Synergistic and Antagonistic Effects:
Synergistic effects occur between pairs of transition
metal ions present in a wastewater. A specific effect of
iron synergism with chromium has been reported and synergism
with other metals may also occur (E-29).
Antagonistic effects may be anticipated with sulfide ion
and hydroxyl ion (high pH), due to precipitation of the sul-
fides and hydroxides of iron. An antagonistic effect should
be expected with cyanide, since the ferrocyanide complex is
very stable and no doubt non-inhibitory to biological pro-
cesses .
Lead
Lead is found in natural waters at trace levels as the
divalent ion. It occurs in domestic sewage as a result of
its presence in the water supply and also as a result of
corrosion of lead plumbing. It is present in industrial
wastewaters from storage battery manufacture, tetraethyl
lead production, and pigment, paint and cement industries.
It also is contributed to wastewater flow as a result of
manufacture and use of lead-containing pesticides.
Summary of Inhibitory Properties:
1. At concentration levels of 0.005 to 0.05 mg/1, lead
has no effect on the activated sludge process. A moderate
"toxicity" of lead to microorganisms has been reported above
0.1 mg/1 and also above 1 mg/1 (E-5).
2. In apparently contradictory results, one paper
states that a significant effect on oxygen uptake is noted
E-20
-------
in the presence of lead from 10 to 100 mg/1 (E-29) , while a
second paper states that no significant change in oxygen con-
sumption is noted at up to 50 mg/1 (E-21).
3. Lead concentrations of up to 0.05 mg/1 have been
reported to have no effect on the nitrifying bacteria
nitrosonomas (E-100).
Manganese
Manganese is found in domestic sewage in trace amounts.
The significant aqueous form is the divalent ion. Manganese
is contributed in the wastewaters from storage battery manu-
facture, paint manufacture, chemical manufacture, etc.
Summary of Inhibitory Properties:
1. It has been reported that a concentration of 7 mg/1
of manganese has no adverse effect on the activated sludge
process. However, two reports indicate that at 10 mg/1 of
manganese, a severe adverse reaction occurred with the acti-
vated sludge process, and a severe inhibition of oxygen up-
take was experienced. Oxygen uptake was completely inhibited
at 50 mg/1 of manganese (E-21).
2. Manganese salts in the concentration range of 12.5
to 50 mg/1 have the unusual property of stimulating the growth
of the microorganism nitrosonomas (E-29).
Synergistic and Antagonistic Effects :
Synergistic effects of manganese with zinc and cadmium
have been reported (E-29). It is probable that similar syn-
ergistic effects may occur with other transition and heavy
metals, and with acidity-
Although no data have been found on antagonistic ef-
fects with manganese, it may be presumed that hydroxide and
sulfide, which can precipitate manganese, will act in this
manner.
Mercury
Mercury forms two series of salts, the monovalent mer-
curous salts and the divalent mercuric salts. Most mercury
salts (of either valence form) are considered to be in-
soluble or sparingly soluble. However, because of the severe
toxicity of mercury to man, fish, wildlife, and lower organisms,
even the slight solubility poses a substantial threat.
E-21
-------
Mercury is found in typical domestic wastewaters at
extremely low levels. Commercial contributions occur
principally from the chlor-alkali industry (chlorine-caustic
soda manufacture). Other sources include chemical, drug,
herbicide, fungicide, and paper products from these industries.
Summary of Inhibitory Properties:
1. At a concentration level of 0.1 mg/1 of mercury, one
paper reports no effect on the activated sludge process
(E-21); another paper reports a 10% reduction in oxygen up-
take (E-28) .
2. A threshold level for adverse effects of mercury on
the activated sludge process is reported at about 2.5 mg/1
(E-21).
3. An investigator reports that at less than 2.5 mg/lr
mercury has little effect on aerobic processes, but at above
5.0 mg/1,aerobic processes are definitely inhibited (E-70).
4. In the concentration range of 1 to 200 mg/1 there
are numerous reports of different degrees of inhibitory effects
on the activated sludge process (E-122, E-29 , E-21).
5. A study of mercury behavior in the sludge digestion
process indicated that 43 mg/1 of mercury in the digester
had no adverse effect, and that 1365 mg/1 had an adverse
effect (E-18).
Nickel
Nickel is a transition metal which forms a series of
divalent (nickelous) salts and trivalent (nickelic) salts.
Only the divalent salts are of interest in wastewater manage-
ment. Nickel is present as a trace constituent in domestic
wastewaters. Nickel is contributed from some commercial
sources at much higher levels, which could disrupt the opera-
tion of a POTW if no control were used.
The major source of nickel contribution to wastewaters
is from electroplating and related metal finishing processes.
Other minor sources of nickel in wastewater arise from cor-
rosion of alloys, dyeing, and printing operations.
Summary of Inhibitory Properties:
1. Activated Sludge Process
a. There appears to be no significant adverse effect
E-22
-------
from nickel concentrations of less than one mg/1 (E-118).
b. A threshold effect of nickel on the activated
sludge process is reported between one and 2.5 mg/1 (E-118).
c. Various adverse effects on the activated sludge
process are reported for nickel influent concentrations of
2.5 to 200 mg/1 (E-19 , E-21, E-25). These include reduced
oxygen uptake between 10 to 50 mg/1 of nickel and inter-
ference with solids settling between 2.5 and 10 mg/1 of
nickel (E-14).
2. Sludge Digestion - The data available on sludge diges
tion in the presence of nickel show little or no effect of
nickel (from 10 to 500 mg/1) on the sludge digestion process
(E-l, E-3, E-4, E-19, E-21, E-29 , E-118). In view of the sen-
sitivity of microorganisms to nickel ions, it is clear that
the reason no effect was noted (except in one instance (A-l),
with up to 500 mg/1 of nickel, is because sulfide and per-
haps hydroxide have precipitated the nickel out of solution,
rendering it harmless. In the absence of adequate sulfide
(or sulfate) in the digester one would expect lower levels
of nickel to interfere with the process.
3. Nitrification - It is reported that a level of one-
half to three mg/1 of nickel has an adverse effect, and 10
mg/1 has a very adverse effect on the nitrification process
(E-25, E-118).
Silver
Silver is a transition metal which forms a series of
monovalent salts. It has few soluble salts. Silver is not
normally a significant constituent of domestic wastewaters.
Because of its relatively high cost, commercial contributors
usually make an effort to recover as much silver as is
economically practical.
The principal source of silver in wastewaters is the
photo processing industry. Silver salts are removed from
photographic film with sodium thiosulfate (hypo), and the
films are rinsed free of the hypo. In large photoprocessing
installations, the silver is recovered from the hypo. Resid-
ual traces in rinse water are not economical to recover, and
these residuals result in contributions to the waste load.
Silver ion is extremely toxic to microorganisms, being
one of the most reliable disinfectants known. Therefore,
it would be anticipated that silver discharges to a POTW
E-23
-------
could cause interferences with its operation. However, in
the case of contributions from the photoprocessing industry,
the sterilizing effect of silver is generally not encountered.
The reason for this anomaly is that virtually all of the sil-
ver released from a photoprocessing plant is in the form of
the thiosulfate complex. This complex does not display any
of the "toxic" properties of silver ion.
Summary of Inhibitory Properties:
1. Free silver ion at the 5 mg/1 level causes an 84%
inhibition of the activated sludge process (E-8, E-9). At
the 25 mg/1 level, inhibition is complete (E-21).
2. In contrast, silver present as the thiosulfate com-
plex, at levels of from 2 mg/1 to greater than 250 mg/1 of
silver had no effect (E-8, E-9).
Sulfate
The sulfate radical is a common constituent of natural
water supplies and, as a result, is also a common constituent
of domestic and commercial wastewater streams. Numerous
industries release sulfates; for example, metal cleaning or
"pickling" is carried out with sulfuric acid, which may be
neutralized and contributed to a municipal sewer. Similarly,
air pollution scrubbers collect abundant quantities of sul-
fates and sulfites which may be released to the sewers.
Summary of Inhibitory Properties:
1. No data have been found on inhibitory effects of
sulfate on the activated sludge process but presumably,
adverse effects would occur at some elevated concentrations.
2. Inhibitory effects have been noted in sludge diges-
tion. At greater than 500 mg/1, an adverse effect of sul-
fate in sludge digesters is reported (E-ll, E-17). At a
level of 2400 mg/1 of sulfate, it is reported that the gas
generation was reduced by less than 12% from that without
high sulfate level. At a sulfate level greater than 2400
mg/1, there is a report of complete cessation of gas pro-
duction (E-19).
Sulfide
The sulfide ion is a common constituent of domestic
wastewater, especially when anaerobic conditions occur. Sul-
fides may be discharged in wastes from petroleum refining,
E-24
-------
the leather tanning industry, and chemical manufacturing in-
dustries.
Summary of Inhibitory Properties:
1. Excessive levels of sulfide would interfere with the
activated sludge process by depleting the dissolved oxygen
transferred in the aeration process. One investigator reports
that 25 to 50 mg/1 of sulfide, is tolerable for about one
week (E-29).
2. Sulfide is beneficial to the anaerobic digestion
process at low concentrations because of its ability to pre-
cipitate transition and heavy metals out of solution. At
higher concentrations, and subject to conditions in the
digester, sulfide becomes inhibitory.
3. Reports of tolerance to sulfide in the sludge
digestion process include the following reports: 50 to 100
mg/1 of sulfide can be tolerated (E-120); 200 mg/1 causes
less than 12% loss in gas generation (E-19); and up to 200
mg/1 of sulfide can be tolerated (E-120).
4. Sulfide concentrations of 150 to 200 mg/1 in the
digester feed reduced gas production considerably (E-35,
E-19).
5. Reports of inhibitory effects include the follow-
ing conclusions: Greater than 50 mg/1 of sulfide reduces gas
production considerably; 100 mg/1 of sulfide causes from
a 33% to 50% loss in gas generation; no methane forms with
more than 165 mg/1 of sulfide; 200 mg/1 of sulfide causes
an 80% loss of gas generation; greater than 200 mg/1 of
sulfide is quite toxic, causing complete cessation of gas
generation; and 400 mg/1 of sulfide causes 95% loss of gas
generation (E-19).
It is clear that the effect of a given level of sul-
fide ion may be quite variable, depending on specific process
conditions. The reported contradictory effects of sulfide on
anaerobic digestion, points to the dependence of inhibition
or tolerance on other factors.
Zinc
Zinc is a transition metal which forms a series of
divalent salts. It has amphoteric behavior; i.e., it forms
zinc cations and zincate anions. Zinc has a rather wide-
spread occurrence, and is a normal constituent of domestic
E-25
-------
wastewaters. Zinc is contributed to sewage flow from a number
of industries, including electroplating, dye and pigment manu-
facture, rubber processing, and electrical generation.
Summary of Inhibitory Properties:
1. Activated Sludge Process
a. A number of reports cite tolerance of the acti-
vated sludge process to zinc, up to concentration levels of
10 mg/1 (E-4, E-6, E-21).
b. There is a report of an adverse effect in the
0.08 to 0.5 mg/1 range and a report that the threshold level
is between 5 and 10 mg/1 (E-29, E-33).
c. Reports of inhibitory effects are given over the
range of 20 to 160 mg/1 (E-118, E-29, E-6, E-5, E-67).
d. Synergistic effects are noted between one mg/1
of zinc with 10 mg/1 of cadmium,between 10 mg/1 of zinc and
100 mg/1 of manganese, and between 10 mg/1 of zinc and 10
mg/1 of cadmium.
2. Sludge Digestion
a. Two references cite no adverse effects of zinc
with the sludge digestion process for 10 mg/1 and 10 to 20
mg/1 of zinc, respectively (E-3, E-6).
b. Two references cite adverse effects of zinc on
the sludge digestion process at 20 mg/1 and 1000 mg/1 re-
spectively (E-118, E-5). Other investigators indicate 5 mg/1
zinc as the upper limit to prevent decreases in digestor gas
production (E-7, A-l), and 10 mg/1 as the highest continuous
dosage that will allow satisfactory digestion (E-78).
3. Solids Settling
a. Adverse effects on solids settling have been
reported for 7.5 and 15 mg/1 slug doses of zinc solution over
a half hour period (E-29).
4. Nitrification - Inhibition of nitrifying bacteria by
0.08 to 0.5 mg/1 of zinc has been reported (E-100)
E-26
-------
Organic Substances
Organic chemicals may be characterized as those com-
pounds made up of carbon in combination with hydrogen, oxygen,
nitrogen, sulfur or phosphorus. The following list is rep-
resentative of some of the categories of organic compounds
with biological and/or commercial importance.
Petroleum products
Perfumes and flavors
Antibiotics and vitamins
Insecticides and fertilizers
Plastics and synthetics
Dyes and pigments
Sugars
Paint and coatings
Explosives and propellants
Wastewaters reaching a POTW may contain any number of organic
substances.
Although most organic compounds appear to be compatible
with aerobic biological treatment systems, some have been.
known to cause treatment plant upsets.
It appears to be generally true that anaerobic digestion
is the biological treatment process which is most susceptible
to upset by inhibitory substances, especially chlorinated
hydrocarbons (E-109). Nitrification is also sensitive to
organics, although acclimation is possible. Autotrophic
bacteria which are involved in nitrification are more readily
inhibited than are the heterotrophic bacteria which are
involved in the oxidation of carbon compounds. Organic
sulfur compounds, especially those with sulfur-carbon-nitrogen
linkage are inhibitors of nitrification (E-109).
The significant organic constituents which have been
identified as having inhibitory effects are discussed below,
and are summarized in Table E-2. In addition to inhibitory
effects, there may be other compelling reasons for limiting
specific parameters, such as those organic constituents which
are proven carcinogens.
Alcohols
An alcohol is a hydrocarbon in which one of the hydrogens
is replaced by a hydroxy (-OH) group. The lower molecular
weight alcohols are relatively polar substances and are com-
pletely miscible with water. With increasing size of the
hydrocarbon group the alcohols become increasingly insoluble
in water. Polyhydroxy alcohols contain more than one hydroxy
group per molecule. One of these, ethylene glycol, is used
E-27
-------
TABLE E-2
THRESHOLD CONCENTRATIONS OF ORGANIC POLLUTANTS
THAT ARE INHIBITORY TO BIOLOGICAL
TREATMENT PROCESSES
CONCENTRATION (mg/1)
POLLUTANT
ACTIVATED
SLUDGE
PROCESSES
ANAEROBIC
DIGESTION
PROCESSES
NITRIFI-
CATION
PROCESSES
REFERENCES
Alcohols
Allyl
Crotonyl
Heptyl
Hexyl
Octyl
Propargyl
Phenols
Phenol
Creosol
2-4 Dinitrophenol
200
100
500
500
1000
200
500
19.5 E-ll, E-129
E-ll
E-ll
E-ll
E-ll
E-ll
4-10 E-23, E-102
4-16 E-102, E-129
150 E-129
Chlorinated Hydro-
carbons
Chloroform
Carbon Tetrachloride
Methylene Chloride
1-2 Dichloroethane
Dichlorophen*
Hexachlorocyclohexane
Pentachlorophenol*
Tetrachloroethylene
1,1,1,-Trichloroethane
Trichloroethylene
Trichlorofluoromethane*
Trichlorotriflouroethane
(Freon)
Allyl Chloride
Dichlorophen
Organic Nitrogen Compounds
Acrylonitrile
10-16
10-20
100-500
1
1
48
0.4
20
1
20
0.7
180
50
E-ll, E-110
E-51, E-103,
E-109, E-107
E-51, E-107
E-109
E-109
E-109
E-109
E-109
E-109
E-109
E-109
E-109
E-129
E-129
E-109
E-28
-------
TABLE E-2 (Continued)
CONCENTRATION (mg/1)
ACTIVATED
SLUDGE
POLLUTANT PROCESSES
Organic Nitrogen Compounds
(Continued)
Thiourea
Thioacetamid
Analine
Trinitrotoluene (TNT) 20-25
EDTA 25
Pyridine
Surfactants
Nacconol 200
Ceepryn 100
Miscellaneous organic
Compounds
Benzidine 500
Thiosemicarbazide
Methyl isothiocyanate
Allyl isothiocyanate
Dithio-oxamide
Potassium thiocyanate
Sodium methyl
dithiocarbamate
Sodium dimethyl
dithiocarbamate
Dimethyl ammonium
dimethyl
dithiocarbamate
Sodium cyclopentamethylene
dithiocarbamate
Piperidinium
cyclopentamethylene
dithiocarbamate
Methyl thiuronium
sulphate
Benzyl thiuronium
chloride
ANAEROBIC
DIGESTION
PROCESSES
NITRIFI-
CATION
PROCESSES
0.075
0.14
0.65
300
100
19.3
23
57
6.5
49
REFERENCES
E-109, E-129
E-109, E-129
E-129
E-33
E-93, E-129
E-102
E-63
E-63
0.18
0.8
1.9
1.1
300
0.9
13.6
E-10
E-129
E-129
E-129
E-129
E-129
E-129
E-129
E-129
E-129
E-129
E-129
E-129
E-29
-------
TABLE E-2 (Continued)
CONCENTRATION (mg/1)
POLLUTANT
Miscellaneous Organic
Compounds (Contd.)
Tetramethyl thiuram
momosuIphide
Tetramethyl thiuram
disulphide
Diallyl Ether
Dimethyl-
par an it roso aniline
Guanidine carbonate
Skatole
Strychnine
hydrochloride
2 chloro6 trichloro-
methyl-pyridine
Ethyl urethane
Hydrazine
Methylene blue
Carbon disulphide
Acetone
8-hydroxyqu inoline
Streptomycin
ACTIVATED
SLUDGE
PROCESSES
ANAEROBIC
DIGESTION
PROCESSES
NITRIFI-
CATION
PROCESSES
50
30
100
7.7
19
16.5
7.0
175
100
250
58
100
35
840
73
400
Note: Concentrations shown represent influent to
the unit process. Where indicated with a *,
the concentration represents total plant
influent.
REFERENCES
E-129
E-129
E-129
E-129
E-129
E-129
E-129
E-129
E-129
E-129
E-129
E-129
E-129
E-129
E-129
E-30
-------
extensively as an antifreeze. Alcohols may be found in the
effluents from the Pharmaceuticals, alcoholic beverages,
anti-freeze chemicals and plastics manufacturing industries.
One investigator reports that 19.5 mg/1 of alkyl alcohol
inhibits nitrification by 75% (E-129) .
Effect of Some Alcohols on Anaerobic Digestion
Inhibitory
Water Concentration
Alcohol Use Solubility (mg/1) _
Allyl Plastics Miscible 100
(CH2=CH-CH2OH)
Propargyl Miscible 50
(CH=C-CH2OH)
Crotonyl Partly 500
(CH3-CH=CH-CH2OH) Soluble
Hexyl Antiseptic Slight 1000
(C6H13OH)
Heptyl Slight 500
(C7H15OH)
Octyl Perfume Insoluble 200
Phenols
Phenols are aromatic hydrocarbons with a hydroxy (-OH )
group substituted for a hydrogen in the ring. Cresols are
phenols with a methyl group substituted for a second hydrogen
in the benezene ring. Domestic wastewaters do not generally
contain significant amounts of phenols. Phenols can cause
significant problems if present in domestic water supplies
since the chlorophenols that may be produced during chlorinat-
ion can be odorous.
Phenols are basic organic chemicals used in many indus-
trial syntheses, including plastics production, dyes, and
E-31
-------
Pharmaceuticals. Phenolic wastewater is also produced as a
by-product of petroleum refining.
Summary of Inhibitory Properties:
There is an extremely diverse reaction to phenolic
wastes in the activated sludge process depending upon whether
the sludge has been acclimated to phenol. Relatively small
amounts of phenol can be inhibitory to unacclimated sludge.
However, with acclimation, and use of the complete mixing
mode of operation, high concentrations of phenol can be tol-
erated. The following results taken from the literature
substantiate this conclusion (E-23).
1. Phenol slug doses of 200 mg/1 can deactivate aerobic
treatment plants by killing the biomass (E-23).
2. One investigator reports a progressive inhibition of
nitrification between 4 and 10 mg/1 of phenol or creosol.
5.6 mg/1 of phenol has been found to inhibit nitrification
by 78% (E-129). Cresol at concentrations of 4-5 mg/1
inhibits nitrification(E-102). 12.6 mg/1 of o-cresol, 11.4
mg/1 of m-cresol and 16.5 mg/1 of p_-cresol were found to
inhibit nitrification by 75% (E-129).
3. 150 mg/1 of 2-4 dinitrol phenol also decreased
nitrification by 75% (E-129).
4. A particular bacteria found in the activated sludge
biomass (bacillus cerus) is capable of metabolizing phenol.
Concentrations of up to 1000 mg/1 of phenol are not harmful
to this species (E-32).
Chlorinated Hydrocarbons
Hydrocarbons in which one or more hydrogen atom is
replaced by a chlorine atom can be classified as chlorinated
hydrocarbons. These materials do not occur in nature but
can be found in domestic water supplies as a result of chlorine
disinfection and the consequent chlorination of trace hydro-
carbons . Chlorinated hydrocarbons are known for their per-
sistance in the environment and are considered especially
dangerous because of their ability to be accummulated in the
tissues of higher life forms. As a result, many chlorinated
hydrocarbons, particularly pesticides, have been banned from
environmental use, or their use has been curtailed.
Chlorinated hydrocarbons are employed in a broad range
of industrial applications including use as solvents and
E-32
-------
degreasing agents, agricultural chemicals, disinfectants,
dry cleaning agents, soaps and shampoos wood preservatives,
propellants and refrigerants, as well as in chemical manu-
facturing. The inhibitory properties of several important
chlorinated hydrocarbons are detailed below.
Chloroform
Chloroform (CHCl^) is a low boiling point liquid which
is only slightly soluble in water. It is used as a solvent
for fats, oils, rubber, alkaloids, waxes, resins, as a
cleansing agent, in fire extinguishers, and in the rubber
manufacturing industry.
Summary of Inhibitory Properties:
1. Continuous doses of chloroform at 16 mg/1 or more
in the raw sludge feed caused inhibition of anaerobic diges-
tion. Continuous doses at concentrations of 10 and 11 mg/1
produced a noticeable drop in gas yield (E-110 , E-ll) .
2. At 1.5 mg/1 of chloroform there is no inhibition of
sludge digestion,while at 14.9 mg/1 inhibition is complete
(E-51) .
3. One investigator reported slight reduction in diges-
ter gas production caused by chloroform at a concentration
of 0.1 mg/1. Also included in this report is a reference
to an investigation that reported a 50% gas reduction due
to 0.96 mg/1 of chloroform (E-107).
4. The effect of shock dosing with chloroform was
determined in laboratory digesters. The table shows the
average percentage inhibition of gas production for each
shock dose in the raw sludge (E-110):
Shock Dose of CHC1,, in
Raw Sludge Feed (mg/1)
1
5
10
16
20
Average % Inhibition
3.1
10
16.9
42.3
54.3
Carbon Tetrachloride
Carbon tetrachloride
is a colorless nonflammable
E-33
-------
liquid which is insoluble in water and has a characteristic
odor. It is very toxic to humans. It is a general purpose
solvent with broad industrial applications. Carbon tetra-
chloride has been used as a fire extinguisher, a drying agent,
a chemical intermediate, and as an exterminating agent.
Summary of Inhibitory Properties:
1. Carbon tetrachloride at levels of 10 mg/1 in sludge
has been found to be toxic to anaerobic digestion (E-109).
2. Carbon tetrachloride is reported to inhibit digestion
as follows (E-51) :
Concentration Level
(mg/1) Percent Inhibition
0.8 0
7.9 40
19.7 90
159.4 100
3. 50% reduction in methane production occurred at 2.2
mg/1 (E-107) .
4. Another investigator showed that 100% inhibition
of gas production during anaerobic digestion required a carbon
tetrachloride dosage of 16 mg/1 (E-103).
Methylene Chloride
Methylene chloride (CH^Cl^) is a colorless, nonflammable,
liquid which is slightly water soluble. It is used as a
solvent for cellulose acetate, as a degreasing agent, clean-
ing fluid and anesthetic.
Summary of Inhibitory Properties:
1. Methane production in anaerobic digestion was re-
duced by 50% in the presence of 100 mg/1 of methylene chloride
(E-107) .
2. Methylene chloride showed the following reduction in
gas production during anaerobic digestion for each dosaqe in
the raw sludge (E-51) :
E-34
-------
Concentration
(mg/1)
Percent Inhibition
1.3
3.3
9.9
132.6
530.4
Chlorobenzenes
0
40
60
80
100
Chlorobenzenes are used as solvents, chemical inter-
mediates , for moth control and as deodorants.
Summary of Inhibitory Properties:
1. The following table presents data on the
inhibitory effect of Chlorobenzenes in batch digestion tests
(E-107) :
Material
Chlorobenzene
Time from
start of
Test (days)
2
4
6
Concentration (% wt/wt dry
sludge solids) in digester
contents
% Reduction in Gas Production
20
1.3
1.0
0.94
35
1.7
1.4
1.3
50
2.1
1.9
1.7
80
3.4
3.4
3.0
Orthodichloro-
benzene
2
4
6
1.1
0.88
0.73
1.6
1.4
1.2
2.4
2.0
1.6
5.4
4.7
3.8
Paradichloro-
benzene
Certi-chlor*
2
4
6
2
4
6
2.1
1.8
1.4
0,7
0.62
0.54
2.6
2.4
2.1
1.6
1.3
1.1
3.0
3.1
2.7
2.5
2.1
2.0
8
7-8
5.3
4.9
4.9
4.3
* A proprietary material similar to ortho-dichlorobenzene
and consisting largely of that material.
E-35
-------
Miscellaneous Chlorinated Hydrocarbons
1. The following table was developed by an investigator
to describe the concentrations of various chlorinated hydro-
carbons that have exhibited inhibitory effects on anaerobic
treatment processes (E-109).
Toxicity of Some Chlorinated Hydrocarbons
to Anaerobic Digestion
Chlorinated Hydrocarbon
Carbon tetrachloride
1,2 Dichloroethane
Dichlorophen
Hexachlorocyclohexane
Methylene Chloride
Pentachlorophenol
Tetrachloroethylene
1,1,1-Trichloroethane
Trichloroethylene
Trichlorofluoromethane
Trichlorotrifluoroethane
Inhibitory Concentrations
In Sewage
img/±;
1
0.4
0.7
In Sludge
10
1
48
20
1
20
2. A slight reduction in digester gas production was
observed as a result of a concentration of 0.1 mg/1 of
1,1,1-trichloroethane (E-107).
3. A 75% reduction in nitrification was reported in
the presence of 180 mg/1 of allyl chloride (E-129).
Agricultural Chemicals
Insecticides, pesticides, and herbicides are manu-
factured from chlorinated hydrocarbons and from organo-phos-
phorus compounds. Some of these materials are damaging to
sewage treatment processes and to fish and wildlife in very
small concentrations (DDT, aldrin, dieldrin). Whereas most
other chlorinated hydrocarbons enter the wastewater stream
as a result of industrial manufacturing processes, agricultural
chemicals usually enter wastewater and natural streams by means of
runoff.
E-36
-------
Summary of Inhibitory Properties:
1. One laboratory test revealed that two pesticides,
aldrin and simazine,were not inhibitory to the growth of
nitrifying bacteria, Nitrobacter, whereas five other pesti-
cides including chlordane, heptachlor, lindane, CIPC, and
DDD prevented growth. Heptachlor was the most deleterious
compound (E-99) .
Organic Nitrogen Compounds
Many organic compounds contain nitrogen, commonly in
the form of a carbon-nitrogen bond. Because of the numerous
nitrogen oxidation levels,the chemistry of organic nitrogen
substances is quite diverse. At its lowest oxidation state
nitrogen forms amines. The most common amine is ammonia.
Amines are classified according to the number of hydrocar-
bon groups attached to the nitrogen atom. Thus one substitu-
tion gives a primary amine, two substitutions give a second-
ary amine, three yields a tertiary amine, and four produces
quaternary ammonium salts. Amines are generally soluble
in water, and ionize, exhibiting varying pH dependent proper-
ties. At its highest oxidation state, nitrogen forms nitro
compounds. These materials are chemically unstable, and are
easily, and sometimes violently reduced (Trinitrotoluene, TNT,
is a typical example). Nitrogen exists at intermediate oxi-
dation states, each producing compounds with differing proper-
ties .
This plethora of nitrogen compounds exerts a wide range
of environmental effects. While some nitrogen compounds
are compatible with biological treatment, others are inhibi-
tory. Some nitrogen is required for satisfactory treatment
plant operation and a nitrogen source must be added to those
trade wastes which are nitrogen deficient. Some organic nitro'
gen compounds are completely biodegradable, whereas others
are toxic to wildlife and some are carcinogenic to man.
Organic nitrogen is contributed to sewage from domestic
wastewaters which contain complex proteinaceous materials,
from agricultural runoff, and from a variety of industrial
operations.
Specifically, this class of compounds is used in the
textile, dye, pharmaceutical, plastics, varnishes, perfume,
insecticide, tanning, synthetic fibers, and solvents indus-
tries .
E-37
-------
Summary of Inhibitory Properties:
1. One investigator reports that 5 mg/1 of acrylonitrile
in sludge has an inhibitory effect on anaerobic digestion
(E-109).
2. Another investigator reports that more than 20 mg/1
of acrylonitrile in sludge is not harmful to anaerobic diges-
tion (E-47) .
3. 0.075 and 0.076 mg/1 of thiourea have been reported
by two investigators as inhibiting nitrification (E-109,
(E-129) .
4. 0.14 and 0.18 mg/1 of thioacetamide have been re-
ported as inhibiting nitrification (E-109, E-129).
5. Analine at a concentration of 0.65 mg/1 was found
to inhibit nitrification by 75% (E-129).
6. At concentrations of 20-25 mg/1 of TNT, aerobic pro-
cesses were severly inhibited (E-33).
7. Increasing amounts of EDTA adversely effect
settleability of secondary sludge and increases surface scum.
At greater than 10 mg/1 there is a decreased utilization
of oxygen. At more than 25 mg/1 there is a toxic effect on
coliform bacteria (E-93). A concentration of 300 mg/1 of
EDTA has been found to inhibit nitrification by 75% (E-129).
g. Pyridine and the methylpyridines which occur in coke
oven liquors are varied in the ability to inhibit nitrifica-
tion (E-102) as follows:
Concentration % Inhibition of
(mg/1) Nitrification
Pyridine 100 100
4-Methylpyridine 100 100
3-methylpyridine 100 No Effect
2-methylpyridine 100 40
Surfactants
This group of chemicals comprises those substances which
have surface active properties. This includes synthetic
detergents, emulsifiers, foaming agents, and wetting agents.
These substances comprise normal constituents in domestic
E-38
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sewage, mostly associated with laundry detergents and com-
mercial cleaning formulations. In addition, they are con-
tributed by numerous industrial and commercial sources, in-
cluding commercial laundries, wool scouring plants, dyeing,
and rubber processing.
Surfactants may interfere with operation of a POTW in
a number of ways. The surfactant may be inhibitory to biologi-
cal processes because of its chemical properties. The sur-
factant may also interfere through various physical effects by
causing excessive foaming, interfering with oxygen transfer
or dispersing the biomass floe and causing loss of solids.
Summary of Inhibitory Properties:
1. Laboratory tests with the anionic surfactant Nacconol
(at 100 mg/1) showed a stimulatory effect on the activated
sludge process. At concentration levels greater than 200
mg/1, inhibitory effects were noted. These effects were
worse at low pH (about 5) and low sludge loadings (E-63).
2. In another laboratory test with the cationic surfactant
Ceepryn, 100 mg/1 of this material suppressed oxygen uptake.
The effect was more deleterious at high pH (about 9) (E-63).
3. In a pilot plant study, it was noted that 10 mg/1
of an alkyl benzene sulfonate (ABS) surfactant had a
negligible effect on the activated sludge process. It was
reported that higher concentrations can be very inhibitory
(E-61) .
4. In another test, 10 and 20 mg/1 levels of ABS
caused minor losses (5 to 8%) in BOD removal efficiency in
the activated sludge process. In the same study, a linear
alkyl sulfate (LAS) at 10 and 20 mg/1 caused a loss of only
one to two percent BOD removal in the activated sludge
process (E-50).
5. A laboratory study determined that a surface active
agent at concentration levels from near zero to 50 mg/1 inter-
fered with oxygen transfer to water (E-92).
6. Digestion is likely to be seriously affected if
the detergent concentration exceeds 2% of the weight of sus-
pended solids. Initiation of digestion processes may be
difficult at a detergent concentration of only 1% (E-109).
E-39
-------
Miscellaneous Organic Chemicals
Benzidine
A laboratory experiment is reported which showed that
500 mg/1 of benzidine inhibited oxygen uptake for 144 hours.
At 5 mg/1, sludge activity decreased (E-10) .
t-butyl Borane
In laboratory tests 500 mg/1 of t-butyl borane was found
to be inhibitory to activated sludge processes.
Formaldehyde
A level of 500 mg/1 of formaldehyde was found to be
stimulatory to activated sludge processes.
Benzene, Toluene, Xylene
Benzene and Xylene at the 1000 mg/1 level are reported
to seriously retard sludge digestion. Toluene at the 500
mg/1 level has no appreciable effect on the process.
Oil and Grease
The term oil and grease covers a wide variety of sub-
stances that might be found in the influent to a POTW. Unlike
other constituents, which usually have well defined chemical
forms, oil and grease characteristics are usually dependent
on the method by which the material is analyzed. Instead
of oil and grease representing a specific chemical species,
it is best defined as those organic substances with similar
solubilities in a particular extracting solvent.
The most commonly used solvents for oil and grease
analysis are hexane, petroleum ether and freon. These sol-
vents will extract a broad spectrum of organic materials,
including fatty acids, soaps, esters, fats, waxes and various
petroleum products (E-131). Frepn is specifically recommended
by EPA as the solvent for oiP"and_...gr.ease extractions. Con-
sequently, it is essential that all oil and grease measure-
ments be completed utilizing the freon method to assure
uniformity of results.
Oil and grease is a natural constituent of sewage. It
has been reported that fecal material contains more than 25%
E-40
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grease (E-129). Additionally, domestic kitchen wastes con-
tribute a large quantity of solvent extractable materials.
Commercial or industrial sources of oil and grease include
slaughter houses, food processers and restaurants, as well
as automobile service stations and petroleum refineries or
storage depots. Although oil and grease from all of these
sources may be extracted by the same solvent, and therefore
considered a single constituent, the substances included
in the analysis may or may not be biodegradeable.
In general, the delineation between biodegradeable oil
and grease and the more refractory extractable substances,
corresponds to the distinction between oil and grease of
animal and vegetable origin versus that of petroleum origin.
Oil and grease of animal and vegetable origin has been reported
to be more biodegrade'able than that of'^etf oleum origin
(E-13) . Nevertheless, many municipalities limit only total
oil and grease (C-98). Traditionally, oil and grease con-
centration limits were focused on the prevention of sewer
clogging and coating of pumping stations and treatment
facilities, in which case the type of extractable material
present was not important. However, distinguishing between
petroleum and animal origin oil and grease can yield informa-
tion on both oil and grease treatability and source.
Another factor to be considered in the impact on POTW
operation is the distinction between the two physical forms
of oil and grease, namely floatable and dispersed or dissolved
material. Generally, many of the adverse effects experienced
by POTW's, which are described below, result from the float-
able portion of oil and grease present in wastewater. These
problems can usually be avoided by employing gravity separation
treatment techniques at the source. If such facilities are
properly operated and^ maintained, floatable oil can be skimmed
and .thus kept out of the sewer system to a substantial degree.
In addition to partially passing through a biol9gical
treatment plant, petroleum oil at concentrations ranging
between 50 and 100 mg/1 has been reported to interfere with
the aerobic processes in a POTW (E-23). It is believed
that the principal interference is caused by attachment of
oil, which has a density less than water, to the bacterial
floe particles, which are to be gravity settled. The result
is a slower settling rate, loss of solids by carryover out
of the settling basin, and excessive release of BOD from the
POTW to the environment (E-108). Additionally, in activated
sludge units, oil and grease may coat the biomass, interfering
with oxygen transfer. As a consequence of this "smothering"
action, a lower degree of treatment may be achieved (E-130).
Oil and grease may also interfere with the operation of physical-
E-41
-------
chemical treatment facilities by quoting the activated carbon
and thus diminishing the adsorption of organic pollutants.
Oil and grease may also cause other problems in POTW
operation. Actual operating problems have been reported in
which oil and grease have clogged screens and interfered with
skimming operations. Large quantities of oil and grease may
block screens, scum draw-off systems and sludge pumps,
causing excessive loads on mechanical scraping and cleaning
devices. Excessive oil and grease may also cause serious
problems in pumping station operation by fouling float systems
so that pumps fail to operate, and by blocking pump intakes.
Additionally, oil and grease may foul electrodes used for
monitoring volatile and explosive mixtures, causing a serious
hazard. Since wetwells are seldom pumped dry, the accumula-
tion of floating oil and grease can cause operational problems
in this portion of the system (E-130).
Among the more troublesome operational problems caused by
oil and grease are those associated with anaerobic digestor
operation. Oil and grease can be responsible for foaming
throughout the plant and especially in digestor vessels. If
oil and grease reaches a covered digestor, a crust may form
on the underside of the cover, causing serious maintenance
problems, and reducing the available digestor volume. Scum
layers in digesters may also interfere with effective mixing,
temperature control and gas separation (E-130).
An ordinance should provide a prohibition on floatable
oil and grease, and a provision for a numerical limitation
on oil and grease of mineral origin. In a majority of cases,
if enforced, these requirements should provide adequate pro-
tection of treatment facilities and enable the municipality
to meet NPDES permit requirements. In cases where the ordi-
nance provisions are inadequate to meet NPDES permit condi-
tions, the POTW would have three options:
1. establish a limitation on oil and grease of mineral
origin more stringent than the proposed Federal pretreatment
standards;
2. provide additional treatment at the municipal plant;
E-42
-------
3. promulgate a limitation on total oil and grease con-
centration adequate to meet NPDES permit conditions.
Option 1 or 3 may require additional pretreatment by industrial
contributors beyond gravity separation for the removal of oil
and grease. If it is necessary to formulate a limit on total
oil and grease concentration, or a more stringent standard
for oil and_grease of mineral origin, the POTW should not
estabTish arbitrary numbers. Rather a systematic approach,
such as utilization of the formula on page C-10, should be
employed to develop equitable limitations appropriate for the
particular system. Stringent oil and grease limits without
a proper basis may result in unnecessary duplication of
treatment provided at the POTW by industrial contributors.
Before deciding which option is most suitable, the munici-
pality should conduct a sampling program to determine the
existing level and characteristics of oil and grease concen-
trations in the treatment plant influent and effluent. The
sampling program should establish the total oil and grease
level, and delineate between oil and grease of mineral origin
and that of animal and vegetable origin, to provide a basis
for selecting the most appropriate course of action.
Discharge of Excessive Levels of Pollutants
Introduction
Sewage plant operations may be impaired by various types
of shock loads. Shock loading has been defined as any rapidly
occurring change in the chemical or physical environment of
a plant's biomass caused by the introduction of a new pollu-
tant, or a change in the rate of flow of a pollutant (E-73).
Four specific types of shock loads are commonly encountered
in POTW ss
1. Materials Deleterious at Trace Levels
The introduction of specifically deleterious mater-
ials such as metallic pollutants (copper, zinc, chromium,
etc.) at trace levels has a well defined impact on treatment
plant operation. These materials interfere with the metabolic
activities within the biomass cells. Because of the precise
nature of this type of shock load, it is possible to set
down in advance the maximum acceptable concentration for
such pollutants.
E-43
-------
2. Qualitative Shock Loads
It has been reported that if a treatment system has
become acclimated to a pollutant, the introduction of a new
type of organic load can block the assimilation of the waste
that the system was treating (E-89). This type of shock
load is termed Qualitative (E-73), and may be caused by the
introduction to a system of a new waste which would normally
be biologically treatable.
3. Quantitative Shock Loads
Quantitative shock loads may be characterized as any
sudden changed in the BOD loading that a plant receives.
Since the type of BOD loading is not changed, as in the case
of qualitative shocks, the result is an inability of the POTW
to treat all of the increased amount of organic matter enter-
ing the plant. Quantitative shock loads are often called
Excessive Discharge to the POTW, and generally refer to the
introduction of unusually large amounts of BOD to the system.
Other oxygen demand parameters such as COD or TOG may be used
to describe quantitative shock loads, but BOD is the most com-
mon measure of organic loading and therefore its use offers
the most general description of the phenomenon.
4. Hydraulic Shock Loads
Hydraulic shock loads are generally characterized by
a rapid decrease in the concentration of the waste or organic
loading of the system (E-73). Such a decrease in loading may
result from the sudden introduction of relatively clean storm-
water into the system, as is common with combined sewers. It
should be noted that the initial portion of runoff from rain-
fall or "first flush" in a combined sewer may contribute a
large quantity of organic matter, actually increasing the BOD
loading as the flow simultaneously increases. Hydraulic shock
loads often cause operating difficulties in POTWs resulting
from the washout of solids from either primary or secondary
sedimentation tanks.
Impact of Excessive Discharge and Shock Loading on
POTW Operation
Contributions of trace deleterious materials and quali-
tative shock loads pose a relatively small, although signifi-
cant, problem to the POTW operation. These two types of
treatment interference can be controlled if the municipality
E-44
-------
places an upper limit on the quantity of the material that
would be acceptable. However, for quantitative shock load-
ing and hydraulic shock loading, setting limits is not
straightforward. Several specific problems arise when trying
to define an approach to controlling these two types of plant
disruption. Each POTW is designed to treat a specific maxi-
mum amount of loading. Most POTW s are operating at levels
which are either above or below design capacity, and each may be
designed to handle differing diurnal flow patterns. Because
of the heterogeneous nature of POTW operations and waste
flows it becomes very difficult to predict in advance what
kind of transient loads a POTW can handle. Some work has been
completed in this area, and one investigator states that
hydraulic shock loads of up to 100% above normal flow can be
accepted without serious disruption of plant operations
(E-71). Another researcher has presented a kinetic model
that may enable some operators to predict the response of
treatment plants to quantitative shock loads (E-72).
The apparent lack of data on approaches to handling
excessive discharges points out that more research into this
area is needed. A first order of priority should be the
development of a firm definition of what constitutes exces-
sive discharge or shock loading, and how differing plant
conditions alter the effects of these types of plant upsets.
For the short term, certain remedial steps can be taken by
plant operators that will reduce the impact of excessive
discharge. Wherever possible, industrial contributors should
be required to implement equalization of concentrated organic
wastes so that they can be released at low flow periods.
Additionally, an effort should be made to regulate industrial
sources of stormwater. Quite often, industrial facilities
discharge stormwater, collected on their plant property, to
sanitary systems that otherwise do not carry stormwater.
To avoid hydraulic overloading, the municipality should dis-
courage this type of activity when practiced indiscriminately-
However, the typical industrial stormwater may be contaminated,
and consequently not of high enough quality to be discharged
to a navigable water directly. Industries should be required
to segregate runoff within the plant, providing for the direct
discharge of clean stormwater. Contaminated runoff should be
collected and stored for subsequent discharge to the sewer.
Equalization of contaminated stormwater for discharge during
low flow periods should decrease the possibility of hydraulically
overloading the POTW, and should be strongly encouraged as a
solution to this problem.
Other Substances Which Interfere with POTW Facilities
This category includes those substances which may interfere
with the operation of a sewage treatment system, but which
E-45
-------
are not necessarily inhibitory to biological processes-
Typical substances of this class include corrosive materials,
substances which cause blockages in sewer lines and flammable
or explosive materials. Although these materials may not
inhibit biological processes, they can cause serious dis-
ruptions of treatment system operations. In the case of-
corrosive or explosive substances, severe damage to collection
or treatment facilities may result from their introduction
into the system. Consequently, corrosive or explosive
materials, as well as substances that may cause sewer line
blockages, are generally totally excluded from POTW systems
by ordinance. Unlike trace inhibitory materials that may
be tolerable, or even beneficial at low levels, the
prohibited materials included in this section should be
closely regulated because of the severity of their effect
on treatment and collection systems.
Corrosive Materials
Corrosion in relation to sewerage systems can be defined
as the phenomenon in which a pipe ,conduit ,or piece of
equipment is gradually deteriorated by the fluid with which
it comes in contact.
For sewage collection systems, one of the most prevalent
types of corrosion is a deterioration of concrete pipe
called "crown" corrosion. In this process, sulfates in
wastewater are reduced under anaerobic conditions to sulfides,
which hydrolyze to hydrogen sulfide. In addition, an
industry such as an oil refinery or textile manufacturer
may discharge sulfides directly to the sewer. If the con-
crete pipe is only partially filled, the H2S formed may
diffuse into the air above the fluid, where the bacteria
Thiobacillus can convert it to sulfuric acid. Sulfuric
acid then reacts with the calcium oxide in the concrete,
forming calcium sulfate or gypsum. This material is
structurally unsound, and will eventually crumble.
Coating the interior of concrete pipes with an inert
material can avoid crown corrosion, but an equally effective
preventative measure is the exclusion of sulfides from the
collection system. Chlorinating sulfide carrying industrial
wastewater is one way of achieving this goal. However, when
the wastewater contains sulfate, which may be present as a
result of non-carbonate hardness in the water supply,
anaerobic conditions in the sewer should be avoided since
they provide the necessary atmosphere for the creation of
H-S. Nevertheless, anaerobic conditions may be unavoidable
in many instances. In those cases, proper sewer ventilation
is necessary not only to provide a measure of safety from
potentially lethal hydrogen sulfide, but also to avoid the
oxidation of E^S to sulfuric acid. Although sulfide may
be beneficial in terms of precipitating metals, its presence
should be closely monitored to avoid crown corrosion.
E-46
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The second type of corrosion is the dissolution of
metallic pipes and structures. This commonly occurs when
wastewater has a low pH, or contains some other oxidizing
agent. Generally, waste mixtures should be pretreated to
fall in the pH range of 6 to 9. Lower pH (acidic) discharges
will attack and disintegrate metal and concrete pipes and
structures. Higher pH values are more tolerable, and enforce-
ment of the high pH restriction should be at the discretion
of the POTW operator. High fluoride levels, especially in
acidic solutions, are a potential corrosion threat. High
concentrations of chlorine, hypochlorites and chlorides are
all corrosive to metals.
Many other products, when reacted with water will form
acidic products which are detrimental to sewer systems.
For example, acetic anhydride will hydrolize to form acetic
acid; acetyl chloride will form acetic and hydrochloric
acids, and ferric chloride will release hydrochloric acid upon
hydrolysis. Sulfur dioxide and sulfurous acid are also common
materials corrosive to sewers and sewage treatment plants.
Materials Which Cause Sewer Blockages
Discharges from commercial and industrial establishments
must be controlled to prohibit materials which will clog
sewers or treatment plants, or form deposits that adversely
affect a sewer's hydraulic characteristics. Precipitates
such as ferric hydrous oxide can interfere with the activated
sludge system by inhibiting oxygen or food transfer between
sludge particles and the surrounding liquids. Sulfates and
carbonates can react with calcium salts to form a scale
which can coat and ultimately block pipes. Fatty acids
similarly react with calcium salts to form a curdy scum
which can coat and block sewer lines.
Very high levels of suspended solids can cause blockages
in sewer lines and overload primary settling tanks. Small
fibers from textile industry operations may interfere
with screens and filters by matting and blocking the passage
of wastewaters.
Grease accumulation can cause sewer line clogging
both in the collection system and in the interconnecting
sewers within the POTW. Collection systems with restuarant
connections are especially prone to blockages, unless suitable
grease collection facilities are provided at the contributing
source. Sewer clogging is most prevalent in small sewer
lines, such as laterals, with 12 inch or smaller diameters.
To cause a blockage problem, oil and grease which is typically
discharged in a liquid or emulsion form, must congeal or
E-47
-------
solidify. Generally, the temperatures encountered in sewers
are high enough to prevent solidification of oil and grease
of petroleum origin (hydrocarbon type). However,oil and
grease of animal or vegetable origin can exhibit a broad
range of congealing temperatures. Some oils and greases of
animal or vegetable origin will congeal at the highest tem-
peratures encountered in sewers, while others may remain
fluid at the lowest temperatures. The probability that oil
and grease will congeal in a sewer pipe depends on a number
of factors including the type of oil and grease involved,
temperature and the fluid velocity in the pipe. A sufficiently
high velocity in the sewer can prevent clogging by keeping
all congealed material in suspension, even if all other con-
ditions are appropriate for solidification.
Explosive and Flammable Materials
The discharge of potentially explosive or flammable
materials to sewer lines must be strictly controlled.
A serious hazard can be created by hydrocarbon solvents,
which float on the surface of water, and exert their full
vapor pressure on the air space above. Such substances as
gasoline, kerosene, naphtha, benzene,toluene and xylene
therefore, are particularly hazardous. Ethers, alcohols,
ketones, aldehydes and organic peroxides similarly pose
fire or explosion hazards.
Powerful oxidizing substances such as peroxides, chlorates,
perchlorates and bromates are potentially dangerous and
should be restricted. Substances which can liberate flammable
or explosive gases such as carbides, hydrides, and sulfides
must also be carefully controlled.
Many of the above chemicals originate from facilities
that manufacture or use organic chemicals. POTWs with such
facilities among their contributors should give special
attention to the control of explosive or flammable materials.
The production of methane in sewers resulting fron anaerobic
conditions also presents a well known potential explosion
hazard. Because of the potential hazards caused by the
presence of explosive materials in sewers, extreme care should
be taken whenever entering a sewer manhole.
Environmental Considerations
Sludge Disposal or Utilization
Interference with the biological unit processes of a
POTW does not represent the only, or necessarily the most
significant impact of industrial contributions. The sludges
produced during the course of biological treatment will
E-48
-------
generally contain, in a concentrated form, many of the pol-
lutants contributed to the POTW that may be considered inhib-
itory. Likewise, if pretreatment of industrial wastes is
practiced, many of the undesirable industrial constituents
undoubtedly will be concentrated in the industrial sludge.
Those responsible for disposing of these sludges should be
aware of the potential impact of industrial wastes (A-20).
Of most concern are those pollutants that are generally con-
sidered deleterious to the environment. Specifically, the
so-called "heavy metals" and various chlorinated hydrocarbons,
such as polychlorinated biphenyls are of major concern.
Depending on the sludge disposal or utilization method
employed, potentially harmful materials in sludges may have
varying effects. Four methods of sludge disposal or utiliza-
tion are currently in common practice. These methods include
(1) land application, (2) disposal in sanitary landfills, (3)
ocean dumping and (4) incineration (A-20, E-132, E-134).
Spreading sludges on land is generally considered a
sludge utilization method, since the sludge acts as a source
of nutrients or as a soil conditioner. Since this method may
result in the contamination of food, however, extreme caution
should be exercised. Because the wastewaters from certain
industries contain concentrations of potentially harmful ele-
ments such as zinc, copper, nickel, cadmium, boron, lead or
mercury which are concentrated in the sludge, it is important
to be aware of the possible effect of these substances on the
environment (E-133). Although trace levels of many of these
elements are essential to plant growth, adding to the natural
elements already present may lead to harmful concentrations.
High concentrations of many of the substances mentioned
above have been noted in sludges derived from purely domestic
wastewaters. Undoubtedly, metals in such systems originate
from relatively uncontrolled sources. Corrosion of metallic
plumbing elements in soft water areas may be such a source,
as is storm water runoff in urban areas having combined sewer
systems. Consequently, the introduction of industrial waste-
water containing incompatible pollutants may intensify the
problem. Special attention must be paid to details such as
the cation exchange capacity of the soils upon which the
sludge is placed, and the general chemistry of the runoff and
ground water likely to be encountered.
Sanitary landfill operations pose similar problems for
disposal of sludges from POTW s with significant industrial
E-49
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wastewater components. Proper precautions must be taken to
adequately protect the environment from the impact of such
sludges when applied to a landfill. The principal considera-
tion in this regard is the leachate that is created by rain-
fall and runoff interacting with the sludge in the landfill.
Metals and other substances present in the sludge are trans-
ferred to the leachate which in turn can adversely affect
surface and ground water in the area. Consequently, control
of leachate in landfills handling sludges with industrial
waste components is of prime importance in the protection
of the aquatic environment.
Incineration of sludges containing incompatible pollu-
tants can also cause environmental problems. Incineration
of such sludges may create a serious air pollution problem.
This situation is not limited only to the volatilization of
heavy metals or chlorinated hydrocarbons, but to other sub-
stances as well. The increasing use of incineration for
sludge disposal in the recent past highlights the importance
of proper consideration of potential air pollution problems.
The design of such facilities must provide adequate safe-
guards to assure that the stack gases will comply with
Federal, State and local air quality and emission standards
and will not cause an adverse impact on the environment.
Sludge may also be disposed of in the ocean. This method
has been practiced on both the east and west coasts of the
United States. East coast POTWs have utilized barges to
transport sludge to areas in the ocean designated for dump-
ing by the EPA and the Corps of Engineers. West coast POTW1s
have utilized long pipelines for ocean disposal of sludge.
Ocean disposal of sewage sludge is currently regulated by the
EPA, with permits being required for this operation. The
environmental impact on the ocean of sludges from POTW's
has been the subject of many studies in the recent past. The
effect on the ocean of incompatible pollutants in sludge has
been an integral part of these studies, which have led to
the close control of ocean disposal currently being exercised.
Reuse of Wastewaters
Environmental considerations relating to the reuse of
wastewaters from POTW's containing industrial contributions
are similar to the factors involved in sludge disposal or
utilization. The primary concern in the reuse of such
wastewaters is the presence of incompatible pollutants
from industrial wastes which may be deleterious to the
environment. The variety of wastewater reuse practices
currently employed result in a wide variation of associated
environmental considerations.
E-50
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The major categories of wastewater reuse are land
application, in which either raw or treated wastewater is
spread over a specific land area, and reuse involving re-
cycle for domestic or industrial purposes. In the case
of land application, reuse generally involves utilization
of the wastewater for agricultural purposes. In addition,
it also implies completion of the hydrologic cycle by return
of the wastewater to the ground water aquifer. Consequently,
the land application of raw or treated wastewater containing
incompatible pollutants to a large degree involves the
same basic concerns as delineated above for the land appli-
cation of sludge.
In the case of direct land application of wastewater,
particularly treated wastewater, the concentration of in-
compatible pollutants from industrial wastes being applied
to the land may be lower than with sludge. In sludge, there
is generally a concentration of such pollutants that occurs
through removal in the wastewater treatment process and de-
watering steps. However, many incompatible pollutants may
only experience incidental removal in the treatment process,
so that the quantity passing through the POTW is greater
than that being removed. Additionally, the volume of
treated effluent from a POTW greatly exceeds the volume of
sludge generated. These two factors suggest that in many
cases the net quantity of incompatible pollutants from
industrial wastes being applied to the land may be greater
with treated wastewater than with sludge. In any event,
careful evaluation of all environmental factors must be
made prior to embarking on a program of wastewater reuse
by land application.
The recycling of treated wastewater varies from reuse
for industrial purposes, to the return of the treated effluent
to the domestic water supply either directly or indirectly.
Concerns associated with the presence of incompatible pollutants
in wastewater being reused in industrial facilities vary
widely depending upon the specific circumstances of the appli-
cation. Many such recycle schemes involve reuse of the waste-
water for cooling purposes or. for make-up to a closed cooling
system. In most industrial situations, environmental con-
siderations are more closely related to the ultimate dis-
position of the wastewater rather than the factors involved
in the industrial reuse application.
The recycling of treated wastewaters to domestic water
supplies by both direct and indirect methods is the area of
greatest concern regarding the presence of incompatible
E-51
-------
pollutants from industrial wastes. In these applications
the principal concern is public health, so that even trace
quantities of many incompatible pollutants may be intolerable,
The methods utilized for recycling vary from direct return to
water supply impoundments, to indirect return via injection
into the groundwater aquifer or discharge to a water course
used for domestic purposes. In either case, the treated
effluent is diluted so that trace quantities of incompatible
pollutants may become undetectable. Nevertheless, it is
possible that a build-up of refractory pollutants may occur
with such recycling over an extended period of time. Con-
sequently, it is imperative that POTWs with industrial
wastewater components contemplating or practicing waste-
water reuse for domestic purposes, exercise careful control
over the incompatible pollutants present to avoid any
possibility of a public health hazard.
E-52
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SECTION F
REMOVAL AND PASS THROUGH OF POLLUTANTS
IN PUBLICLY OWNED TREATMENT WORKS
Introduction
Data Collection
Data Compilation
Data Analysis
Limitations of Data Reported
Plant Performance
Characterization of Primary and Biological Plant
Performance
-------
SECTION F
REMOVAL AND PASS THROUGH OF POLLUTANTS IN
PUBLICLY OWNED TREATMENT WORKS
Introduction
The purpose of this section of the report is to summarize
available information on removal and effluent concentrations,
or pass-through of pollutants in POTW's. It is intended to
be responsive to the portion of Section 304(f) of PL 92-500
which states, "Guidelines under this subsection shall be
established to control and prevent the discharge....(either
directly or through publicly owned treatment works) of any
pollutant which interferes with, passes through, or otherwise
is incompatible with such works".
The information contained herein was obtained from a survey
of POTW's having analytical data for influent and effluent
concentrations of incompatible pollutants. Specific emphasis
was placed on obtaining data on the concentration of metals in
POTW systems. Data was obtained from a total of 269 treatment
facilities for 61 pollutant parameters. Wastewater flow in
the POTW's represented by the survey varied from less than 0.05
MGD to more than 110 MGD. The major portion of plants in the
survey, a total of 101 POTW's,were in the range of 1.0 to
5.5 MGD,representing 38 percent of the total number of facilities
reporting data. Computer facilities were utilized to summarize
and analyze the data obtained. The summary computer reports
are presented in Appendix 6 of these guidelines.
The discussion which follows describes data sources,
procedures used in data compilation, limitations of the
reported data, and plant performance evaluation for primary,
trickling filter and activated sludge plants. A limited
discussion of biological treatment plants with chemical
addition and tertiary plants is also presented, along with the
results of correlation and regression analyses for selected
pollutant parameters. A characterization of the performance
of primary and biological treatment plants (trickling filter
and activated sludge) is presented in terms of percent removal
and efffluent concentration (pass through) for the 17 most
significant pollutant parameters.
The performance characterization results contained in
this section, are presented only to provide guidance in deter-
mining pretreatment requirements where sufficient operational
data is not available at a specific POTW. The data is not
intended to serve as a substitute for detailed influent and
effluent sampling of the treatment plant, which will provide
F-l
-------
the most reliable removal and pass through information for
the system in question. However, the data does present removal
and pass through information which may be considered typical
of many conventional primary and biological treatment plants.
Data Collection
In accumulating data, an attempt was made to compile a
broad base of valid removal and pass through information on
various sewage treatment processes. An extensive search was
undertaken covering data in the published literature and
unpublished data collected by Federal, State and interstate
agencies, and individual sewerage system operators. With the
cooperation of the EPA Region II office, NPDES permit
applications from publicly owned treatment works were evaluated
as a potential source of removal and pass through data. It
was concluded that permit applications were generally not a
good source for this information.
However, another data source from the EPA regional
offices, compliance monitoring reports, was identified as a
significant source of removal and pass through information.
Compliance monitoring reports are prepared by the EPA
regional enforcement or State enforcement programs^for POTWs
with NPDES permits. These reports summarize the results of
on-site monitoring, usually performed on a continuous basis
for 24 or 48 hours. In some EPA regions, monitoring encom-
passes both influent and effluent streams, while in other
regions only the plant effluent is sampled. In the regions
where influent and effluent data were available, these reports
were found to be an excellent data source in that they usually
covered a wide range of pollutant parameters and were generally
uniform in format.
Although the compliance monitoring program has just
recently begun, these reports nevertheless represent about
40 percent of the total data base compiled. Most of the
reports obtained were from EPA Regions V and VII, as their
programs are well advanced, and both plant influent and
effluent are sampled.
Interstate pollution control agencies, river basin
commissions, State agencies, and individual sewer system
operators were contacted in the data collection phase of the
work. Most of the governmental agencies contacted did not
compile removal or effluent data on parameters other than
those normally associated with domestic sewage, except where
it was known or suspected that industrial wastewater was
interfering with or passing through the system. However,
P-2
-------
those State agencies and interstate commissions which did pro-
vide valid comprehensive data comprised about 50 percent of
the total data base compiled. Individual POTWs and the pub-
lished literature constituted only an estimated 10 percent
of the compiled data. Most POTW1s contacted were not sampling
for comprehensive removal parameters on a routine basis.
The literature was found to contain very little specific
plant removal or pass through data on parameters other than
those normally used for the analysis of domestic sewage.
Altogether, removal and pass through data was obtained
from 269 plants, geographically distributed according to
Report No. 1 of Appendix 6.
Data Compilation
Reported data was categorized according to treatment
process, treatment flow rate, and percent industrial flow.
Report No. 2 of Appendix 6 summarizes the treatment process
and flowrate categories, most of which were used in grouping
the data reported. Plant processes were categorized into five
major classes as follows:
A - Primary Sedimentation Treatment Process
B - Trickling Filter
C - Activated Sludge
D - Filtration
J - Miscellaneous
Additional plant and sampling information was also
collected. Report No. 3 of Appendix 6 details the sampling
procedure, sampling date, major industrial contributors, and
level of POTW control over industrial contributors. The
sampling procedure is indicated as either flow proportioned
composite (FC), time composite (C), or grab (G). If a com-
posite sample was taken the sampling duration is then indi-
cated. The final item shown under sampling procedure is (S)
for simultaneous sampling at influent and effluent, or (R)
for sampling performed with plant retention time taken into
account. The sampling date is indicated as Year/Month/Day,
and under the remarks column, the composite interval, or the
method of data summary is indicated. Where the information
,was readily available, major industrial contributors and the
level of POTW control over industry is also shown. The
level of control is a subjective measure ranging from no
control (0) to very tight control (10) with surveillance
and monitoring.
Data was compiled according to STORET numbers for 61
parameters as indicated in Report No. 7 of Appendix 6. Com-
puter processing was utilized in data handling and analysis,
F-3
-------
resulting in the reports shown in Appendix 6, and the corre-
lation and regression analyses which follow.
Data Analysis
Analysis of accumulated data includes a discussion of
the limitations of the data reported, analysis of 6 hour
simultaneous sampling results, evaluation of plant perfor-
mance data, and correlation and regression analyses for
statistical relationships within the reported data.
Limitations of Data Reported
There are three major areas in which the data reported
is limited; selection of plants, sampling variation, and
plant performance variation. One governmental source of
reported data indicated that in most cases their basis for
selecting POTWs for sampling was that the plant was having,
or was suspected of having, operating problems. This type of
data has been excluded from the data compilation insofar as
it could be recognized. However, the possibility of data
bias toward malfunctioning plants should be noted. This
could be particularly true with regard to data obtained from
enforcement or compliance activities. Nevertheless, signifi-
cant differences on a broad basis between data from compliance
monitoring and that obtained from other sources was not noted.
Since the reported data was not obtained from a controlled
survey, the method of sampling was therefore not consistent.
It was suspected that data from 6 hour simultaneous sampling
procedures might not be valid, because plant detention time
was not taken into account. Report No. 4 of Appendix 6 was
prepared to compare sampling results from 24 hour composites
and 6 hour simultaneous composites for similar plants. It
was expected that this comparison might show a higher level
of removal with 6 hour sampling. This was not confirmed by
the comparison, and, in fact, an opposite trend was exhibited
in some instances. It was therefore concluded that the 6
hour, and all simultaneous sampling results, should be
included in the reported data. However, since sampling
methods could not be compared at a single plant, a potential
data misrepresentation still exists due to sampling variation.
Plant performance variation is the greatest single area
of data limitation. A single days sample from what may be
a highly variable plant operation may not accurately charac-
terize the removal effectiveness of the plant in question.
Much of the data obtained in the survey is of this type and
therefore may be open to question on the basis of represen-
tativeness .
Insofar as possible, the reported data is for typical
plant operation, and where more than one sampling was
F-4
-------
available, average values were reported. In several instances,
a great deal of data was available for specific plants where
specialized test programs are underway or thorough monitoring
is performed on a routine basis. Average values for these
facilities were utilized and entered as one data point for
each pollutant parameter in the computer analysis. Consequently,
several of the data points in the analysis are extremely rep-
resentative of plant performance, but were compared on an
equal basis with data far less representative. This is a
possible additional limitation of the results reported.
Nevertheless, a broad spectrum of plants was covered by this
analysis and significant variation between the average results
obtained and values reported for the plants with significant
quantities of data was not noted.
Plant Performance
Report No. 5 of Appendix 6 is a summary of removal data
for 40 parameters grouped by plant treatment process as
follows: conventional primary plants (Al), other primary
plants (A02), conventional trickling filter plants (Bl),
other trickling filter plants (B02, B04, BOS), conventional
activated sludge plants (Cl), other activated sludge plants
(C02, COS, C06, C09, C19, C20), and miscellaneous plants
(D, J). It was concluded from this report that the conventional
primary, trickling filter, and activated sludge plant groups
could be expanded by incorporating the specialized categories
of these processes into a summary type of analysis. Similarly,
Report No. 7 of Appendix 6 is a summary of effluent or pass
through data for all 61 parameters for plant groups as out-
lined above for Report No. 5.
In addition to the regrouping of plants under the expanded
headings of primary, trickling filter, and activated sludge
plants, upon review of Reports 5 and 7, it was also decided
that the miscellaneous and "other" plants should be grouped
as biological treatment plants with chemical addition, and
tertiary plants. The following table summarizes the various
treatment plant groups as discussed above, and defines the
plant categories included in each group for further reference.
Report No. 6 of Appendix 6 is a summary of removal data
for all primary, trickling filter and activated sludge plants
not utilizing chemical addition. Additional plant groups
also included in this report defined as "biological plants"
include the sum of trickling filter and activated sludge
plants; "secondary plants", those plants meeting the EPA
definition of secondary treatment (an effluent BOD and SS
less than or equal to 30 mg/1, and a removal of 85% or
greater for both parameters); and "total all plants", the
F-5
-------
TABLE F-l
DISTRIBUTION OF POTW DATA BY PLANT PROCESS
(PP) Primary Plants
(TFP) Trickling Filter Plants
(ASP) Activated Sludge Plants
(BPCD) Biological Plants
with Chemical
addition
(TP) Tertiary Plants
Other Plants
Category
A01, A02
601,602,604,605
C01,C02,C05,C06,C09,
C19,C20
603,C03,C04,C14
C07,C08,C10
D01,D02,D03,D04,D05,
D06,D07
A03,A04,A05
J01,J02
No. of
Plants
79
81
83
8
3
8
3
4
243
8
11
TOTAL
269
F-6
-------
sum of all 269 plants' data. The number of plants reporting,
the maximum and minimum percent removal/ the mean removal, and
the standard deviation of the removal data are given for each
parameter under the plant groups discussed above. It should
be pointed out that the number of secondary plants can not
be related as a percentage of the number of biological
plants because not all biological plants reported the data
required for secondary plant selection. Report No. 8 of
Appendix 6 is a summary of effluent or pass through data in
a format similar to the removal report discussed above.
The removal and effluent data summary reports were
utilized in a selection of parameters for more detailed
examination. The criteria used in this selection were twofold;
the importance of the parameter in the context of project
objectives, and the number of plants for which data was
reported. On this basis the following parameters were selected:
Cadmium (CD)
Chromium (CR)
Lead (PB)
Mercury (KG)
Copper (CU)
Nickel (NI)
Zinc (ZN)
Iron (FE)
Manganese (MN)
Phosphorus-Total (P-TOTAL)
Total Kjeldahil Nitrogen (TKN)
Ammonia (NH3)
Phenolics (PHEN)
Total Organic Carbon (TOC)
Chemical Oxygen Demand (COD)
Suspended Solids (SS)
Biochemical Oxygen Demand, 5 Day (BOD)
All the metallic parameters represent total concentrations
rather than the soluble fraction of the metal. COD data
represents the sum of COD values obtained by the three
methods of analysis listed in Reports 6 and 8 of Appendix 6.
Tables F-2 and F-3 are summaries of the removal and effluent
or pass through data for the selected parameters. Figures
F-l thru F-17 are cumulative distribution curves of the
removal and effluent data for the same parameters. The data
utilized for these curves is presented in Tables 6-1 and
6-2 of Appendix 6.
Characterization of Primary and Biological Plant
Performance
Table F-4 summarizes the removal and effluent or pass
through data reported for primary and biological treatment
F-7
-------
TABLE F-2
REMOVAL DATA SUMMARY
FOR PRIMARY, TRICKLING FILTER
AND ACTIVATED SLUDGE PLANTS (SELECTED PARAMETERS)
I
no
Parameter Primary Plants (PP)
StandardMax/ No.of
Mean Deviation Min Plants
CD 8 17 76/0 31
CR 26 26 80/0 36
PB 24 26 88/0 34
HG 27 29 75/0 21
CU 26 24 77/0 44
NI 6 18 92/0 28
ZN 31 22 88/0 38
FE 40 22 89/0 27
MN 15 20 81/0 16
P-TOTAL 13 8 24/0 7
TKN 22 20 60/0 7
NH3 20 16 64/0 42
PHENOL 38 - 50/25 2
TOC 24 19 56/0 30
COD 26 - 82/0 18
SS 51 18 92/17 47
BOD 30 22 89/0 52
Trickling Filter Plants(TFP) Activated Sludge Plants (ASP)
Mean
20
37
37
30
54
21
46
50
31
26
50
41
50
64
71
75
77
Standard
Deviation
25
30
31
23
24
23
22
26
23
22
27
30
28
18
-
19
18
Max/
Min.
75/0
99/0
93/0
67/0
95/0
86/0
89/0
90/0
72/0
99/0
94/7
99/0
85/0
84/8
95/34
97/20
96/5
No. o
Plant
35
48
41
20
49
32
52
30
21
24
20
48
12
23
36
66
60
Standard
Max/ No. of
lean Deviation Min. Plants
17
46
39
39
57
20
58
63
38
42
34
49
69
73
75
75
84
27
34
32
32
24
21
25
27
32
25
26
31
31
12
-
22
15
88/0
98/0
95/0
99/0
95/0
80/0
9S/0
98/8
93/0
92/0
92/5
99/4
98/0
89/42
94/24
99/9
99/18
44
54
49
34
63
44
58
35
19
36
11
47
16
13
40
62
65
Notes:
1. PP = A01, A02 plants (Ref. Appendix 6, Report No. 2)
2. TFP = B01, B02, D04, BOS (Ref. Appendix 6, Report No. 2)
3. ASP = C01, C02, COS, C06, C09, C19, C20 (Ref. Appendix 6, Report No. 2)
-------
TABLB P-3
EFFLUENT DATA SUMMARY
FOR PRIMARY, TRICKLING FILTER
AND ACTIVATED SLUDGE PLANTS (SELECTED PARAMETERS)
i
vo
Mean
CD (jig/1) 14
CR " 188
PB " 156
HG " 1.0
CO " 191
NI " 165
ZN " 550
FE " 1520
MN " 176
P-TOTAL(ng/l)12.9
TKN 24.4
NH3 " 20.2
PHENOL ()ig/l)16
TOC (mg/l)142
COD " 346
SS " 93
BOD " 167
Primary Plants (PP)
Standard
Deviation
9
406
272
1.3
278
387
658
1020
112
22
11.6
34.6
23
84.2
-
62
111
Max/Min
40/3
2600/6
1700/10
5.0/0.1
1700/10
1700/6
3600/30
5000/400
390/30
77/1 . 3
47/8.5
256/2.1
53/0.1
539/52
768/58
314/15
650/20
No. of
Plants
35
40
37
23
48
33
49
30
22
10
-
63
-
35
19
54
58
Trickling Filter Plants (TFP)
Mean
11
235
116
1.0
133
198
316
2910
136
9.02
16.8
16.6
209
54.3
133
43
48.6
Standard
Deviation
10
563
276
2.0
283
336
464
11000
130.
3.8
11.9
17.2
772
26.3
-
37
47.3
Max/Min
66/1
3200/3
1800/5
10.0/0.1
1800/3
1533/7
2800/40
65600/100
580/20
18.3/3.3
47.8/1.2
.115/0.03
3000/0.03
129/23
361/18
228/5
245/4.0
No. of
Plants
41
52
45
22
54
38
57
34
28
27
21
65
13
23
38
66
61
Activated Sludge Plants (ASP)
Mean
50
202
67
6.0
92
165
238
747
144
5.2
19.0
11.1
135
35.3
86
37
28.3
Standard
Deviation
277
515
68
32
195
387
257
1170
200
2.7
9.6
7.6
473
22.4
-
39
40.7
Max/Min
1970/1
2520/5
350/3
200/0.1
1600/8
1700/6
1400/10
6800/100
940/10
10.4/1.0
34/1.5
27.5/0.07
2000/0.02
95.0/10
275/14
185/2
230/2.0
No. of
Plant*
46
60
51
37
68
56
66
37
23
40
12
63
16
14
42
64
65
Notes >
1. PP - A01, A02 Plants (Ref. Appendix 6, Report Nc. 2)
2. TFP - B01, B02, B04, BOS (Ref. Appendix 6, Report Mo. 2)
3. ASP - C01, C02, COS, C06, C09, C19, C20 (Ref. Appendix 6, Report No. 2)
-------
TABLE F-4
CHARACTERIZATION OF PRIMARY AND BIOLOGICAL
PLANT PERFORMANCE
Primary Plants (PP)
Biological Plants (BP)
Parameter
Percent
Removal
CD
CR
PB
HG
CU
NI
ZN
FE
MN
P-TOT
TKN
NH3
PHEN
TOC
COD
SS
BOD
Oig/D
it
it
11
H
ii
it
11
"
(mg/l)
II
II
fug/1)
(mg/l)
II
II
II
7/8
16/26
20/24
22/27
18/26
6/6
26/31
35/40
8/15
ID/13
ID/22
17/20
ID/ 38
20/24
18/26
50/51
28/30
Effluent
Concentration
Percent
Removal
Effluent
Concentration
(50% >)/(mean) (50% <)/(mean) (50% >)/(mean) (50% <)/(mean)
11/14
90/188
110/156
0.6/1.0
110/191
75/165
300/550
1300/1518
160/176
10/13
ID/24
13/20
ID/16
125/142
340/346
78/93
140/167
9/18
41/42
41/38
38/35
56/56
16/21
52/52
59/57
28/35
32/34
40/42
37/45
68/60
71/69
75/73
80/75
85/81
10/30
50/218
60/92
0.6/3.5
50/113
65/182
160/277
600/1827
90/140
6/7
17/18
12/14
2.5/175
45/25
100/110
30/40
28/39
Notes:
1. ID
2. PP
3. BP
= Insufficient data reported.
= A01, A02 (Ref. Appendix 6, Report No. 2)
= TFP + ASP = B01, B02, B04, BOS, C01, C02,
COS, C06, C09, C19, C20.
F-10
-------
plants. Removal data has been reported as the mean and the
removal equalled or exceeded by 50% of the plants reporting,
as estimated from Figures F-l thru F-17. The estimated 50%
value should be considered an approximation of the median,
since a graphical determination does not meet the statisti-
cal definition of median. Similarly, effluent data has been
reported as the mean and the effluent concentration which
has not been equalled or exceeded by 50% of the plants re-
porting, as estimated from Figures F-l thru F-17.
Table F-4 and the figures show that the removal of metals
in primary plants was generally low, with cadmium, nickel and
manganese having the lowest removals. Mean effluent con-
centrations were 14 jug/1 for cadmium, 165 pg/1 for nickel and
176 pg/1 for manganese. Removal of chromium, lead, copper and
mercury was somewhat higher, while zinc and iron removals were
the highest of the metals in primary plants. Mean effluent
concentrations were 550 jug/1 for zinc, and 1518 Jjg/l for iron.
In biological treatment plants, cadmium, nickel and
manganese were removed least, with chromium, lead, copper
and mercury removals being slightly higher. Mean effluent
concentrations of up to 30 jug/1 for cadmium, 182 jug/1 for
nickel, and 140 jug/1 for manganese were reported. Zinc,
iron, and copper had a relatively high percentage of removal
in biological treatment plants. Mean effluent concentra-
tions of up to 277 >ug/l for zinc, 1827 /ag/1 for iron, and
113 ;ug/l for copper were reported. These data would tend
to indicate that iron, zinc and copper are most susceptible
to removal in conventional treatment facilities, while
cadmium, nickel and manganese are the least susceptible
of the metals to removal.
The removal of pollutant parameters related to organic
pollution, total phosphorus, kjeldahl nitrogen, ammonia,
and phenolics in primary plants was on the order of 13 to
38 percent. Mean effluent concentrations of 13 mg/1 for
P-TOT, 24 mg/1 for TKN, 20 mg/1 for NH3 and 16 ;ug/l for
phenolics were reported. In biological plants, the remov-
als for these parameters were on the order of 32 to 65 per-
cent. Mean effluent concentrations of 7 mg/1 for P-TOT,
18 mg/1 for TKN, 14 mg/1 for NH3, and 175 ;ug/l for phenolics
were reported.
The removal of the more general parameters of pollu-
tion, TOC, COD, SS, and BOD in primary plants was on the
order of 18 to 51 percent. Mean effluent concentrations of
142 mg/1 for TOC, 346 mg/1 for COD, 93 mg/1 for SS, and
F-ll
-------
167 mg/1 for BOD were reported. Removals of these param-
eters in biological plants were on the order of 69 to
81 percent, with mean effluent concentrations of 25 mg/1
for TOC, 110 mg/1 for COD, 40 mg/1 for SS, and 39 mg/1
for BOD.
F-12
-------
FIGURE F-l
CADMIUM
CUMULATIVE DISTRIBUTION OF EFFLUENT DATA
CUMULATIVE DISTRIBUTION OF REMOVAL DATA
Al
16-
z 8-
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tu
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0 20 40 60 80 100
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0 20 40 60 80 100 0 20 40 60 80 100
PERCENT OF PLANTS
20 40 60 80 100
TRICKLIN3 FIUTER
PLANTS
0 20 40 60
100
0 20 40 60 80 100
20 40 60 80 100
PERCENT OF PLANTS
NOTES'-1-WlS THE NUMBER OF PLANTS REPORTED
2-BIOLOGICAL PLANTS" IS THE TOTAL OF TRICKLING FILTER & ACTIVATED SLUDGE PLANTS
3-CADMIUM REPORTED AS CD, TOTAL
-------
FIGURE F2
CHROMIUM
CUMULATIVE DISTRIBUTION OF EFFLUENT DATA
CUMULATIVE DISTRIBUTION OF REMOVAL DATA
I
M
4^
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A AA
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PERCENT OF PLANTS
0 20 40 60 80 100 0 20 40 60 80 10
PERCENT OF PLANTS
NOTES'- 1-WlS THE NUMBER OF PLANTS REPORTED
2-"BIOLOGICAl PLANTS" IS THE TOTAL OF TRICKLING FILTER & ACTIVATED SLUDGE PLANTS
3-CHROMIUM DEPORTED AS CR,TOTAL
-------
CUMULATIVE DISTRIBUTION OF EFFLUENT DATA
CUMULATIVE DISTRIBUTION OF REMOVAL DATA
ouu-
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2-"BIOLOGICAL PLANTS" IS THE TOTAL OF TRICKLING FILTER & ACTIVATED SLUDGE PLANTS
3-LEAD REPORTED AS PB,TOTAL
-------
FIGURE P4
MERCURY
'-t.U
^ P -
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\ 1 C -
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0 20 40 60 80 100 0 20 40 60 80 100
PERCENT OF PLANTS
NOTES'- I-VIS THE NUMBER OF PLANTS REPORTED
2-"BIOLOGICAL PLANTS" IS THE TOTAL OF TRICKLING FILTER & ACTIVATED SLUDGE PLANTS
3-MERCURY REPORTED AS HG, TOTAL.
-------
FIGURE F-5
COPPER
CUMULATIVE DISTRIBUTION OF EFFLUENT DATA
CUMULATIVE DISTRIBUTION OF REMOVAL DATA
DUVJ
400
3 AA
OUVJ
J AA
C.\J{J
1 AA
1 UU
n
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0 20 40 60 80 100 0 20 40 60 80 100
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80-
PR
PLA^JTS
100-
80-
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0 20 40 60 80 100
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0 20 40 60 80 100
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A
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0 20 40 60 80 100 0 20 40 60 80 100
PERCENT OF PLANTS
NOTES'-I-VlS THE NUMBER OF PLANTS REPORTED
2-"BIOLOGICAL PLANTS" IS THE TOTAL OF TRICKLING FILTER & ACTIVATED SLUDGE PLANTS
3-COPPER REPORTED AS CU,TOTAL
-------
FIGURE F6
NICKEL
CUMULATIVE DISTRIBUTION OF EFFLUENT DATA CUMULATIVE DISTRIBUTION OF REMOVAL DAT/
Fwr\A ' c.r\f\ i/-v/-\ . ir\r^
DUU
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0 20 40 60 80 100 0 20 40 60 80 100
PERCENT OF PLANTS
NOTES'-1-VlS THE NUMBER OF PLANTS REPORTED
2-"BIOLOGICAL PL ANTS" IS THE TOTAL OF TRICKLING FILTER & ACTIVATED SLUDGE PLANTS
3-NICKEL REPORTED AS NI;TOTAL
-------
FIGURE F-7
ZINC
CUMULATIVE DISTRIBUTION OF EFFLUENT DATA
CUMULATIVE DISTRIBUTION OF REMOVAL DAT/
800-
0-
TRICKLJNG FRjTER
PLANTS
51
0 20 40 60 80 100
1000-
BIOLOGIC/L PL
X
0 20 40 60 80 100 0 20 40 60 80 IQO
PERCENT Of PLANTS
PR
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PLA *TS
s °-
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0 20 40 60 80 100 0 20 40 60 80 100
PERCENT OF PLANTS
NOTES'-1-"N" IS THE NUMBER OF PLANTS REPORTED
2-BIOLOGICAL PLANTS" IS THE TOTAL OF TRICKLING FILTER &. ACTIVATED SLUDGE PLANTS
3-ZINC REPORTED AS ZN/TOTAL
-------
FIGURE F-8
IRON
CUMULATIVE DISTRIBUTION OF EFFLUENT DATA
CUMULATIVE DISTRIBUTION OF REMOVAL DATA
CiSGOO-
^ O
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to
o
1=3D
PLA (ITS
4800'
0 20 40 60 80 100
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kNTS
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0 20 40 60 80 100 0 20 40 60 80 100
PERCENT Of PLANTS
80-
Al
I
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PLA
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0 20 40 60 80 100
100-
80-
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PERCENT OF PLANTS
NOTES'--1-VlS THE NUMBER OF PLANTS REPORTED
2-'BIOLOGICAt. PLANTS" IS THE TOTAL OF TRICKLING FILTER & ACTIVATED SLUDGE PLANTS
3-IRON REPORT ED AS FE, TOTAL
-------
FIGURE F-9
MANGANESE
CUMULATIVE DISTRIBUTION OF EFFLUENT DATA CUMULATIVE DISTRIBUTION OF REMOVAL DAT/
/*!«»/> /~/-\/-\. . i/-\*-% irs/^,
480
Al ~m A
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NOTES'- I-VIS THE NUMBER OF PLANTS REPORTED
2-BIOLOGICAL PLANTS" IS THE TOTAL OF TRICKLING FILTER & ACTIVATED SLUDGE PLANTS
3-MANGANESE RE PORTED AS MN, TOTAL
-------
FIGURE F-IO
PHOSPHORUS
CUMULATIVE DISTRIBUTION OF EFFLUENT DATA CUMULATIVE DISTRIBUTION OF REMOVAL DAT/
Al 1 p_
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0 20 40 60 80 100 0 20 40 60 80 100
PERCENT OF PLANTS
NOTES:-1-VlS THE NUMBER OF PLANTS REPORTED
2-BIOLOGICAL PL ANTS" IS THE TOTAL OF TRICKLING FILTER & ACTIVATED SLUDGE PLANTS
3-PHOSPHORUS REPORTED AS P, TOTAL
-------
FIGURE F-ll
KJELD-AHL NITROGEN
40
i '°
7-^0
s
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PRI
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DATA
PLA-
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0 20 40 60 80 100
ACTI\ATEC SLUPGE
P LAI ITS
10-
0:
""
6 20 40 60 80 100 0 20 40 60 80 100
PERCENT OF PLANTS
)N OF EFFLUENT DATA CUMULATIVE DISTRIBUTION OF REMOVAL DATA
50 'I t r\r\ \r\f\
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NOTES'- I-VIS THE NUMBER OF PLANTS REPORTED
2-"BIOLOGICAL PLANTS" IS THE TOTAL OF TRICKLING FILTER & ACTIVATED SLUDGE PLANTS
-------
FIGURE F-12
AMMONIA
CUMULATIVE DISTRIBUTION OF 'EFFLUENT DATA
CUMULATIVE DISTRIBUTION OF REMOVAL DATA
Al
24-
2 '
8-
cc
UJ
Q
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0 20 40 60 80 100
24
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PL/iNTS
0 20 40 60 80 100
BIOL
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X
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0 20 40 60 80 100 0 20 40 60 80 100
PERCENT OF PLANTS
80-
60-
4
PRIMARY
PLA
MTS
0 20 40 60 80 100
IUU
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0 20 40 60 80 100
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BIOLQGICA. PL/
N=95
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NTS
0 20 40 60 80 100 0 20 40 60 80 100
PERCENT OF PLANTS
NOTES'-I-VlS THE NUMBER OF PLANTS REPORTED
2-BIOLOGICAL PLANTS" IS THE TOTAL OF TRICKLING FILTER & ACTIVATED SLUDGE PLANTS
-------
FIGURE F-13
PHENOLICS
CUMULATIVE DISTRIBUTION OF EFFLUENT DATA
CUMULATIVE DISTRIBUTION OF REMOVAL DATA
/M
e>
<
cc
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15
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0 20 40 60 80 100 0 20 40 60 80 100
PERCENT Of PLANTS
Al
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-------
FIGURE F-14
TOTAL ORGANIC CARBON
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-------
FIGURE F-15
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-------
FIGURE F-16
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CUMULATIVE DISTRIBUTION OF REMOVAL DATA
20 40 60 80 100
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PLANTS" 4S THE TOTAL OF TRICKLING FILTER & ACTIVATED SLUDGE PLANTS
-------
FIGURE. F-l 7
BIOCHEMICAL OXYGEN DEMAND
CUMULATIVE DISTRIBUTION OF EFFLUENT DATA
CUMULATIVE DISTRIBUTION OF REMOVAL DATA
200-
0 20 40 60 80 100
20 40 60 80 100
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NOTES'- I-VIS THE NUMBER OF PLANTS REPORTED
2-"BIOLOGICAL PLANTS" IS THE TOTAL OF TRICKLING FILTER & ACTIVATED SLUDGE PLANTS
-------
SECTION G
GLOSSARY
Acclimatization (Acclimation) - A process by which the bio-
logical organisms in a biological treatment system develop
the capability of maintaining normal life cycles in the
presence of concentrations of pollutants that would normally
inhibit their activity.
Antagonism - Reduction of the inhibitory effect of one sub-
stance by the presence of another.
Compatible Pollutant - A pollutant which is normally treated
by conventional biological sewage treatment processes.
Contribution (Contributors) - A point source originating
within the area served by a sewerage system and treatment
works.
Existing Source - Any wastewater source, which was contri-
buting to a sewerage system, (or a potential source that was
under construction), at the time of publication of proposed
regulations.
Federal Water Pollution Control Act Amendments of 1972 -
Public Law 92-500 which provides the legal authority for
current EPA water pollution abatement projects, regulations
and policies.
Incompatible Pollutant - Any pollutant which is not normally
treated by conventional biological sewage treatment processes,
Industrial Waste Ordinance - An enforceable local law which
establishes rules, regulations, limitations and prohibitions
to be adhered to by wastewater sources within the service
area of a publicly owned sewer system.
Inhibition - A contribution that decreases the pollution
removal efficiency of a biological treatment facility -
Interference - A contribution that hinders in any way the.
operation of a wastewater collection and treatment system.
Inhibition can be considered a type of interference.
Joint Treatment - The treatment of a wastewater consisting
of a combination of domestic and industrial flows in a
single treatment system which has been specifically designed
to handle the combined wastewater.
G-l
-------
Limited Waste - A waste, which by either local ordinance or
Federal regulation, cannot be present in a contribution or
direct discharge above a certain concentration.
Major Contributing Industry (MCI) - A major source of
industrial wastewater within a POTW system, as defined in
the Federal pretreatment standards.
Monitoring - The practice of investigating, surveying and/
or sampling wastewater sources in an effort to obtain infor-
mation on the quality or quantity of the wastewater flow.
National Pollutant Discharge Elimination System (NPDES) -
A system of permits to discharge wastewaters to navigable
waters developed under the authority of Section 402 of Public
Law 92-500. The permit system has as its objectives the
achievements of the goal of that law, the elimination of
the discharge of pollutants by 1985.
New Source - A wastewater source for which construction
began after the publication of proposed regulations.
Pass Through - The discharge to the receiving waters from
a publicly owned treatment works of a pollutant without sub-
stantial modification or removal.
Pretreatment - The treatment of a wastewater contribution,
at the point of origin, prior to release to a publicly owned
treatment system.
Prohibited Waste - A material which must be excluded from
any discharge of wastewater to a collection system in any
concentration. Prohibited wastes include, among others,
explosive or corrosive materials.
Publicly Owned Treatment Works (POTW) - A sewerage facility
which collects, treats or otherwise disposes of waste-
waters, owned and operated by a village, town, county,
authority or other public agency.
Synergism - An increase in the inhibitory effect of one
substance caused by the presence of another.
Upset - A substantial decrease in the treatment efficiency
of a biological treatment system caused by changes in the
life cycles of the biological organisms comprising the
system.
G-2
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SECTION H
ACKNOWLEDGMENTS
The Environmental Protection Agency wishes to acknowl-
edge the following members of the Burns and Roe technical
staff for their significant contributions to the overall
project effort and the development of these guidelines:
Arnold S. Vernick, P.E. Project Manager
William A. Foy, P.E. Senior Environmental Engineer
Howard D. Feiler, P.E. Senior Environmental Engineer
John L. Rose, P.E. Manager, Environmental
Engineering
Paul D. Lanik, P.E. Senior Environmental Engineer
Barry S. Langer, P.E. Environmental Engineer
Benjamin J. Intorre, Ph.D. Engineering Specialist
Paul J. Storch Environmental Engineer
Judith Liebeskind Environmental Engineer
Jameel Ahmad, Ph.D. Senior Civil Engineer
Edgar G. Kaup, P.E. Senior Chemical Engineer
The assistance of Mrs. Marilyn Moran of Burns and Roe
in the physical preparation of this document is specifically
noted.
The support of all Environmental Protection Agency per-
sonnel contributing to this effort is specifically noted.
The development of the Guidelines was under the direc-
tion of:
Gary F. Otakie Project Officer
William A. Whittington Chief, Municipal Technology
Branch
Charles H. Sutfin Deputy Director, Municipal
Construction Division
The following organizations within the Environmental
Protection Agency were extremely helpful and enthusiastic in
providing all assistance and information requested:
Region I Office, Boston, Massachusetts
Region II Office, New York, New York
H-l
-------
Philadelphia, Pennsylvania
Atlanta, Georgia
Chicago, Illinois
Dallas, Texas
Kansas City Missouri
Denver, Colorado
San Francisco, California
Seattle, Washington
Cincinnati, Ohio
Cincinnati, Ohio
Edison, New Jersey
Office of Planning and
Standards
Office of Planning and
Standards
Region III Office,
Region IV Office,
Region V Office,
Region VI Office,
Region VII Office,
Region VIII Office,
Region IX Office,
Region X Office,
National Environmental
Research Center,
Quality Assurance and
Methods Development
Laboratory,
Edison Water Quality
Research Laboratory,
Effluent Guidelines
Division,
Criteria and Standards
Division,
Office of Research and
Development,
Office of Planning and
Evaluation
Office of Enforcement
Office of General Counsel.
The Environmental Protection Agency wishes to thank rep-
resentatives of the following State, interstate, city, county
and regional agencies for their cooperation and assistance in
meeting with EPA and Burns and Roe representatives, and fur-
nishing requested data,information, and providing guidance
for the formulation of these guidelines:
Bureau of Pollution Control
Atlanta, Georgia
Department of Natural Resources
State of Georgia
Sewer Utility
Boulder, Colorado
Department of Water and Pollution Control
Wichita, Kansas
H-2
-------
Water Pollution Control Department
Topeka, Kansas
Department of Environmental Protection
State of Connecticut
Department of Public Works
Wilmington, Delaware
Maryland Water Resources Administration
Havre De Grace, Maryland
Department of Public Works
Fitchburg, Massachusetts
Department of Environmental Protection
State of Massachusetts
Department of Water Resources
New York, New York
Township of Towamencin, Pennsylvania
Interstate Sanitation Commission
New York, New York
County Sanitation Districts of Los Angeles County
Whittier, California
Department of Ecology
State of Washington
Municipality of Metropolitan Seattle
Seattle, Washington
Regional Water Quality Control Board
State of California
Delaware River Basin Commission
Trenton, New Jersey
Metropolitan Sewer District of Greater Cincinnati
Hamilton County, Ohio
Division of Water Quality
Muncie, Indiana
H-3
-------
East Bay Municipal Utility District
Oakland, California
Dallas Water Utilities
Dallas, Texas
Water Reclamation Research Center
Dallas, Texas
Metropolitan Sanitary District of Greater Chicago
Chicago, Illinois
Department of Natural Resources
State of Wisconsin
Department of Natural Resources
State of Michigan
Department of Environmental Resources
State of Pennsylvania
Department for Natural Resources and Environmental
Pollution, State of Kentucky
New England Interstate Water Pollution Control
Commission, Boston, Massachusetts
Cleveland Regional Sewer District
Cleveland, Ohio
Sanitary District of Rockford, Illinois
Acknowledgment is made to the following industrial
organizations for assistance provided:
Soap and Detergent Association
New York, New York
National Canners Association
Washington, D.C.
Diamond Crystal Salt Company
Akron, Ohio
H-4
-------
Rohm and Haas Company
Spring House, Pennsylvania
Contributors to the preparation of the Effluent Guide
lines Development Documents which served as a basis
for Appendix 8.
Information furnished by the following consulting
engineers is also hereby acknowledged:
Camp Dresser & McKee
Boston, Massachusetts
McPhee, Smith, Rosenstein Engineers
Buffalo, New York
H-5
* U.S. Government Printing Office: 1977-778-501/118 Regions
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