PB90-108853
Interferences at Publicly Owned Treatment Works
Montgomery (James M.) Consulting Engineers, Inc., Pasadena, CA
Prepared for:
Environmental Protection Agency, Cincinnati, OH
Sep 86
I
wa

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EPA/600/2-89/053
September 1986
INTERFERENCES AT PUBLICLY OWNED
TREATMENT WORKS
by
Edward D. Wetzel and Scott B. Murphy
James M. Montgomery, Consulting Engineers, Inc.
Pasadena, California 91109
Contract No. 68-03-1821
Project Officer
Sidney A. Hannah
Wastewater Research Division
Water Engineering Research Laboratory
Cincinnati, Ohio 45268
WATER ENGINEERING RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268

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TECHNICAL REPORT DATA
(Plrcsc rcod //utrucftoits un the rcicrte before completing)
\. REPORT NO. 7.
EPA/600/2-89/053
3. R.F£i£JlNTS ACCESSION NO.
PB 90 1 0 3 8 5 3 /AS
¦». TITLE AND SUBTITLE
Interferences at Publicly Owned Treatment Works
5.	REPORT DATE
September 1986
6.	PERFORMING ORGANIZATION COOt
\ AUTHOH(S)
Edward D. Wetzel and Scott B. Murphy
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME ANO AOORESS
James M. Montgomery, Consulting Engineers, Inc.
Pasadena, CA 91109
10.	PROGRAM ELEMENT NO.
11.	CONTRACT/GRANT NO.
68-03-1821
12. SPONSORING. AGENCJV NAME ANO AOORESS
Water Engineering Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
26 W. St. Clair St., Cincinnati, OH 45268
13. TYPE OF REPORT AND PERlOO COVI HEO
Working Document 7/85-9/86
14. SPONSORING AGENCY COOG
EPA/600/14
^.SUPPLEMENTARY NOTES
Project Officer: S. A. Hannah (513-569-2621; FTS: 684-2621)
16. ABSTRACT
The discharge of heavy metals, Loxic oryunics and variable strength conventional pollu-
tants from industrial (and other nondomestic) sources can have negative impacts on the
operation of publicly owned treatment works (POTWs). Such industrial discharges can
result in an interference at POTWs, recently redefined by the U.S. Environmental
Protection Agency (EPA) to mean "...causation of a POTW's noncompliance with its permit
or inability to lawfully use or dispose of its sludge." This LPA-funded study considers
the sources of and contaminants causing interference , the impact on the POTW, and the
mitigation techniques available for interference prevention. The approach to the study
involved a review of the technical literature published during the last 5 years, a
telephone survey of all state environmental agencies and identified municipalities, and
site visits to nearly 30 POTWs that have been successful in their attempts to mitigate
interference problems. ;The results of the study indicate thai interference effects can
be minimized with an effective program that combines the following elements: technical 1/
sound and enforceable industrial waste permits for all significant discharges, comprehen
sive monitoring of industrial discharges and POTW plant influent, the ability to track
plant upsets to the source of the discharge; and in-plant operational control to mitiyat-
the impact of industrial wastes on POTWs. Information in this work document was condense
into a "Guidance Manual for Preventing Interference at POTWs" (September 1987) distribut.
by U.S. EPA, Office of Water Enforcement and Permits. 401 M. St.. SW. , w,i',liin.jfmi nr
' (-7V KEY WORDS AND DOCUMENT ANALYSIS
i. DESCRIPTORS
b. IDENTIFIERS/OPEN ENDED TERMS
c. cosati Field/Group



18. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURI T Y CLASS (Tins Report)
UNCLASSIFIED
21. NO. OF PAGES
231
20. SECURITY CLASS lT!lis page!
UNCLASSIFIED
22. PRICE
-41/
EPA porm 2220-1 (R«v. 4-77) Pnevioui edition n obsolcte
i

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DISCLAIMER
The information in this document has been funded wholly or in part by the United
States Environmental Protection Agency under Contract No. 63-03-1821 to
James M. Montgomery, Consulting Engineers, Inc. It has been subject to the
Agency's peer and administrative review, and it has been approved for
publication as an EPA document. Mention of trade names or commercial
products does not constitute endorsement or recommendation for use.
ii

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FOREWORD
The U.S. Environmental Protection Agency is charged by Congress with
protecting the Nation's land, air, and water systems. Under a mandate of
national environmental laws, the agency strives to formulate and implement
actions leading to a compatible balance between human activities and the ability
of natural systems to support and nurture life. The Clean Water Act, the Safe
Drinking Water Act, and the Toxic Substances Control Act are three of the
major congresssional laws that provide the framework for restoring and
maintaining the integrity of our Nation's water, for preserving and enhancing the
water we drink, and for protecting the environment from toxic substances.
These laws direct the EPA to perform research to define our environmental
problems, measure the impacts, and search for solutions.
The Water Engineering Research Laboratory is that component of EPA's
Research and Development program concerned with preventing, treating, and
managing municipal and industrial wastewater discharges; establishing practices
to control and remove contaminants from drinking water and to prevent its
deterioration during storage and distribution; and assessing the nature and
controllability of releases of toxic substances to the air, water, and land from
manufacturing processes and subsequent product uses. This publication is one of
the products of that research and provides a vital communication link between
the research and the user community.
This document addresses problems encountered by municipal wastewater
treatment facilities in meeting the goals of the Clean Water Act. It specifically
relates to the Water Engineering Research Laboratory's concern for the
protection of publicly owned treatment works from the discharge of
conventional, nonconventional, and toxic pollutants from industrial sources.
Francis T. Mayo, Director
Water Engineering Research Laboratory
iii

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ABSTRACT
The discharge of heavy metals, toxic organics and variable strength conventional
pollutants from industrial (and other nondomestic) sources can have negative
impacts on the operation of publicly owned treatment works (POTWs). Such
industrial discharges can result in an interference at POTWs, recently redefined
by the U.S. Environmental Protection Agency (EPA) to mean "...the causation of
a POTW's noncompliance with its permit or inability to lawfully use or dispose of
its sludge".
This EPA-funded study considers the sources of and contaminants causing
interference, the impact on the POTW, and the mitigation techniques available
for interference prevention.
The approach to the study involved a review of the technical literature published
during the last 5 years, a telephone survey of all state environmental agencies
and identified municipalities, and site visits to nearly 30 POTWs that have been
successful in their attempts to mitigate interference problems. The results of
the study indicate that interference effects can be minimized with an effective
program that combines the following elements:
•	technically sound and enforceable industrial waste permits for all
significant dischargers;
•	comprehensive monitoring of industrial discharges and POTW plant
influent;
•	the ability to track plant upsets to the source of the discharge; and
•	in-plant operational control to mitigate the impact of industrial
wastes on POTWs.
This report was submitted in fulfillment of Contract No. 68-03-1821 by
James M. Montgomery, Consulting Engineers, Inc., under the sponsorship of the
U.S. Environmental Protection Agency. This report covers the period
July 17, 1985, to September 30, 1986, and work was completed as of
September 30, 1986.
iv

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CONTENTS
Page
Foreward			 iii
Abstract			. .		iv
Figures		vi
Tables					vii
Acknowledgements 						 viii
Conversion Factors 								ix
1.	Introduction				 				.		1
Background 			-				1
Scope of Work						2
2.	Conclusions						4
Summary 		4
Research Needs				5
3.	Literature Review 		8
General Wastewater		10
Primary Treatment				14
Secondary Biological Treatment				16
Advanced Treatment 			 . . 			37
Sludge Processing 			45
Summary 				48
4.	Telephone Survey 				51
Procedure						51
General Survey Results		52
Regional Results			54
5.	Case Studies 				61
Selection Process						61
Site Visit Logistics 										72
Case Study Reports 							78
6.	Results							 79
Monitoring								79
Interference				 ,	84
Mitigation 						93
References		102
Appendices
A.	List of Interfering Substances	 125
B.	Project Forms	 128
C.	Case Study Reports 					139
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FIGURES
Number	Page
1	Geographical Regions						55
2	Potential Case Studies		62
3	Selected Case Studies 		74
C-l Impact of Industrial Waste Discharge on		141
POTW Loadings (Bayshore, NJ)
C-2 Wastewater Discharge at Influent 			160
Metering Station (Maiden Creek, PA)
C-3 Monthly Acute Toxicity (Patapsco, MD)			169
C-4 HCPCF Influent pH (Horse Creek, SC)		179
C-5 91st Avenue Influent Metals				199
C-6 West Point Chromium Concentrations		220
(Metro Seattle, WA)
vi

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TABLES
Number	Page
1	Common Treatment Plant Upsets 		15
2	Metal Removal Efficiency by Activated		23
Sludge
3	Metal Concentrations Inhibiting the 		23
Activated Sludge Process
4	Potential Case Studies - Northeast		63
5	Potential Case Studies - Southeast 		66
6	Potential Case Studies - Midwest		68
7	Potential Case Studies - Southwest		70
8	Potential Case Studies - Northwest		71
9	Selected Case Study Sites		73
10	Case Study Sites - Secondary Treatment 		75
Process
11	Case Study Sites - Treatment Plant Size 		76
12	Case Study Sites - Industrial Contributors 		77
13	Metal Concentrations Inhibiting Acclimated		89
Biological Processes
14	Organic Compound Concentrations Inhibiting 		90
Acclimated Biological Processes
15	Conventional Pollutant and Inorganic Compound		91
Concentrations Inhibiting Acclimated
Biological Processes
vii

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ACKNOWLEDGEMENTS
Thjs document was prepared by James M. Montgomery, Consulting Engineers,
Inc., under EPA Contract No. 68-03-1821. Mr. John Grantham was the Project
Manager, with Dr. Edward Wetzel and Mr. Scott Murphy acting as Project
Engineer and Assistant Froject Engineer, respectively. Messrs. Wetzel and
Murphy are the principal authors of this report, with contributions from
Dr. Roger Stephenson to portions of Section Z (Literature Review), hi addition
to the staff listed above, site visits were made by Messrs. David Harrison and
Paul Skage:* ajid by Ms. Sheila McShane. The contributions of a number of other
members of me Pasadena engineering staff to the literature review, and of the
support staff to the production of this report, are gratefully acknowledged.
This report was prepared under the technical direction of Dr. Sidney Hannah of
the Water Engineering Research Laboratory (WERL), with M.-. Gregory McBrien
and Ms. LeAnne Hammer of the Permits Division, Office of Water Enforcement
ar.d Permits. Additional guidance and assistance was provided by the other
members of the Pretreatment Support Group of WERL, consisting of
Messrs. James Kreissl, Dolloff Bishop, Richard Dobbs, Kenneth Dostal and Henry
Tabak.
viii

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CONVERSION FACTORS
This document is written primarily using English (customary) units. The
following multipliers can bo used to convert from English to the applicable SI
units for parameters user! h. this report.
Customary Unit
Multiplier
SI Unit
foot (ft)
gallon (gal)
gal/cf/day
gal/sf/day
gal/min (gpm)
lb/cf/day
Ib/sf/day
mgd
0.3048
3.735
0.1337
0.04074
5.450
16.02
4.883
3785
meter (m)
liter (1)
m^/m^/d
ni^/m^/d
m3/d
kg/m^/d
kg/m2/d
m^/a
i:r

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SECTION 1
INTRODUCTION
The purpose of this study is to investigate the impact of industrial dischai-ges on
the operation of publicly owned treatment works (POTWs). Specifically,
interferences resulting from the presence of toxic organics, heavy metals, or
variable-strength conventional pollutants emanating from industrial sources are
the focus of this report. Industrial wastewaters are often blamed for process
ups-its that occur at municipal wastewater treatment facilities. However, in
many cases, such upsets may simply be the result of improper operation and
maintenance practices. Pajak, et al. (1977) have indicated a lack of definitive
information 0,1 treatment plant upsets, particularly with respect to the actual
causes of violating discharge permit standards. The intent of this document is
not to assess blame, but rather to identify cause and effect relationships and to
seek techniques for the mitigation of upsets created by the introduction of
abnormal contaminants into POTWs.
BACKGROUND
The enactment of the Federal Water Pollution Control Act Amendments
(FWPCA, PL 92-500) on October 18, 1972, established the National Pollutant
Discharge Elimination System (NPDES) permit program requiring any entity
discharging treated wastewater into a receiving water course to obtain a NPDES
Permit. Industrial permits issued under PL 92-50^' required industries to employ
the best practicable technology (BPT) available to limit discharges of conven-
tional pollutants such as BOD, TSS, and fats, oil, and grease (FOG) (Silva, 1981).
The FWPCA requirements were amended by the Clean Water Act (CWA,
PL 95-217), which was signed into law on December 28, 1977. This legislation
brought about significant changes for industrial dischargers, calling on the EPA
to focus its attention on controlling toxic pollutants. The EPA Administrator
was directed to establish a list of toxic pollutants with effluent limitations for
each. Industries with permits would then be required to utilize the best available
technology (BAT) economically feasible for the control of toxics and the best
conventional technology (BCT) currently available to control the discharge of
conventional pollutants (Snyder, 1978).
Industries that discharge to POTWs need not obtain a NPDES Permit; rather they
are subject to the General Pretreatment Regulations promulgated on
June 26, 1978, and subsequently amended on January 28, 1981 (40 CFR Part 403).
The regulations establish both categorical preireatment standards and prohibited
discharge standards for the control of wastewater discharges into POTWs. The
categorical pretreatment standards apply to the most significant industrial and
1

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commercial sources of toxic pollutants from specific industrial categories. The
prohibited discharge standards, which apply to all industrial and commercial
sources, prohibit the discharge of pollutants that:
•	create a fire or explosion hazard;
•	are corrosive;
•	obstruct wastewater flow;
a upset treatment processes, or
•	increase the influent wastewater temperature above 40°C.
The General Pretreatment Regulations require POTWs with a hydraulic design
capacity greater than 5 mgd to establish a formal pretreatment program.
POTWs with smaller design flow may also be required to establish such programs
if their industries are subject to national categorical pretreatment standards or
if there is a history of nondomestic discharge problems or NPDES permit
violations. A POTW without a pretreatment program may still develop and
enforce local limits for the prevention of specific interference problems as
needed to ensure compliance with an MPDE5 permit or sludge disposal practices.
Problems associated with the implementation and perceived complexity of the
pretreatment program slowed the progress of this effort. In response, the
Pretreatment Implementation Review Task Force (PIRT) was established on
February 3, 1984 by EPA Administrator Ruckeishaus. The task force was
composed of 17 representatives from POTWs, States, industry, environmental
groups, and EPA Regions. The charge given to the PIRT was to identify
problems experienced by industry, States, and POTWs with respect to the
pretreatment program, and to make recommendations to the EPA for program
improvement.
In their Final Report to the Administrator (U.S. EPA, 1985), the PIRT considered
five problem areas affecting implementation. The first problem area was *.he
perception that the pretreatment program is complex and difficult to under-
stand. For this problem, the task force recommended that the EPA sponsor a
program of regional workshops, guidance manuals and seminars. One of the
specific problems identified by PIRT was the difficulty experienced by POTWs in
the recognition, tracking, and mitigation of interferences caused by industrial
discharges. Their recommendation was for the EPA to provide guidance to
municipalities regarding such interference problems. This report is part of the
EPA's response to that recommendation.
SCOPE or WORK
Impacts of industrial waste discharges on POTWs were broken down by JRB
Associates (1981b) into six categories:
•	Pass-through and water quality
•	Interference and upsets
•	Sludge contamination
•	Worker health and safety
•	Air pollution
•	Groundwater pollution
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It is the second category, interference and upsets, that is addressed in this study.
The U.S. Congress recently redefined (Federal Register, June 19, 1985) inter-
ference to generally mean "...the causation of a POTW's noncompliance with its
permit or inability to lawfully use or dispose of its sludge". The operative word
in this new definition is causation, which replaces the phraseology "contributes
to a violation" from the original regulations. Since the interference definition
includes sludge disposal considerations, category three above (sludge contamina-
tion) is also within the scope of this study. The work associated with the
production of this report extended over a 9-month period from mid-July 1985
until the end of April 198o. The overall work plan was divided into three main
task assignments:
•	Literature review
•	Telephone survey
•	Case histories
An extensive search of the recent literature pertaining to the treatabilty and
impact of industrial wastes in the POTWs was the first step taken to understand
the problem. Three hundred articles and reports were selected for detailed
review from an initial list of nearly 8,000 titles. The complete review is
presented in Section 3 of this report.
State and Federal regulatory agencies, sanitation districts, and major cities and
municipalities were contacted by telephone in an effort to uncover specific
interference problems in their respective jurisdictions. Surveying each of the
50 state environmental agencies was also a primary source for contacts at
POTWs with industrial wastewater problems. Section 4 documents the results of
this work effort.
The literature review and telephone surveys helped generate a list of some
120 municipal treatment facilities as potential case studies. Thirty of these
plants were selected for one-day site visits based on the criteria discussed in
Section 5. This portion of the study was the most productive in terms of
developing effective procedures for the correction of industrial waste contamin-
ation problems.
Section 6 attempts to synthesize the information presented in the report into a
coherent plan of action for POTWs. This section will become the basis for the
preparation of an abridged guidance manual for operations and management
personnel at municipal treatment facilities.
3

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SECTION 2
CONCLUSIONS
SUMMARY
The literature and case studies discussed in this report reflect the diversity of
interference issues and concerns. The literature reviewed in Section 3 consists
of all English-language-published work from 1980 through 1985 available to the
authors by established searching techniques, pertaining to interference or
treatment of industrial wastewaters. A large portion of that work is devoted to
the effects of industrial pollutants on activated sludge processes. In general, the
quantity of literature available on interferences decreases from suspended
growth biological processes (including anaerobic systems) to fixed film processes
to physical-chemical treatment. The design and operations concepts that
permeated the reviewed literature included:
•	Acclimation. Biological systems will acclimate to industrial wastes
that are discharged at a consistent level. Highly variable industrial
discharges cause the greatest inhibition problems.
•	Staged Treatment. The use of staged or series treatment typically
results in better degradation of industrial wastes than if the same
treatment units are used in parallel.
•	Operations Modifications. The POTW operator has operational tools
available (particularly at an activated sludge plant) that can mitigate
the effects of industrial contaminants.
•	Influent Wastewater Characteristics. The concentration and form of
metal and organic contaminants has an important effect on the
treatability of the waste and is dependent on a number of inter-
related factors.
The telephone survey discussed in Section 4 served to reinforce the idea of the
diversity of industrial interference being experienced by POTWs. The survey was
conducted nationwide and consisted of telephone interviews with regional, State,
and local officials involved with wastewater treatment and pretreatment
programs in all 50 states. The findings of the telephone survey support several
general conclusions about POTW interference:
•	The major cause of interference is highly variable discharge of
conventional pollutants.
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•	Treatment plants most adversely affected are less than 5 mgd in size
with one or two major industrial contributors.
•	Interference mitigation is most successful when POTWs have inv )lved
industry in source control (pretreatrnent) program development in a
cooperative atmosphere.
•	Some POTW interference problems result from poor wastewater
characterization before facility design.
The case studies reported in Section 5 represent a wide cross-section of
interference mitigation efforts. The POTWs studied reflect diversity in terms of
size, treatment process, interfering pollutants and industries, and methods
utilized to control interference. The reports served to reinforce the findings of
the previous two chapters in addition to presenting interesting methods for
implementing source control measures.
Section 6, Results, synthesizes the information presented in the previous three
chapters and discusses the necessary aspects of a successful pretreatrnent
program. Monitoring of POTW wastewater streams (influent, side streams, etc.),
operations monitoring and industrial user monitoring are discussed. Interference
is also discussed with special emphasis on identification and type of interference.
A section is included that lists interfering compounds and typical reported
inhibiting concentrations. Section 6 also discusses the many aspects of
interference mitigation including pretreatrnent and source controls and
treatment plant controls.
RESEARCH NEEDS
The literature review, surveys and site visits performed as part of this project
have identified a number of areas where additional bench-scale, pilot-scale and
full-scale research would be helpful in identifying and mitigating the impacts of
industrial wastewaters on POTWs. For convenience, these research needs have
been subdivided into four general areas:
•	treatment processes
•	plant operations
•	toxicity testing
•	management aspects
Treatment Processes
The volume of data available on the impact of nonconventional pollutants
(particularly the heavy metals) on activated sludge and anaerobic digestion is
sizeable. Unfortunately, the results demonstrate the vulnerability of both
processes to the discharges from a variety of industrial wastewaters. Design
engineers are becoming less inclined toward conventional suspended growth
biological processes. This has been largely responsible for the use of powdered
activated carbon augmentation of activated sludge for adsorption of priority
organics. Additional process modifications such as the use of pure oxygen or
anaerobic selector zones should be more thoroughly evaluated relative to their
resistance to industrial discharges.
5

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Fixed film treatment had nearly become a forgotten technology for wastewater
processing prior to the development and acceptance of plastic media. Since
then, RBC and biotower systems have become popular alternatives because of
their low maintenance and ease of operation. However, problems of clogging,
excess biomass development, odors and reduced process efficiency potentially
attributable to industrial wastes have occurred. More research on the impacts of
specific substances on RBCs, plastic media trickling filters and fluidized bed
systems (aerobic and anaerobic) is needed. Staged systems such as roughing
filters followed by activated sludge or the trickling filter-solids contact process
should be similarly evaluated.
The final area of research regarding unit operations deals with solid-liquid
separation. The impacts of metals and organics on the performance of clarifiers,
thickeners (flotation and gravity) and dewatering devices (vacuum filters, belt
presses, plate and frame presses and centrifuges) are essentially unknown at this
time. Similarly, little consideration has been given to the response of advanced
wastewater treatment processes to industrial compounds, except as pertains to
the treatment of contaminated sources for drinking water purposes.
Plant Operations
The major research need in the area of plant operations is the identification of
specific cause and effect relationships between industrial pollutants and
individual unit processes. For example, high levels of surfactants in an influent
wastewater stimulates the production of white foam on top of activated sludge
reactors; yet the growth of a dark brown foam may indicate a toxicity problem.
It would be quite useful to relate the color and degree of foaming to specific
classes of toxic compounds. Such knowledge would aid in both the mitigation and
source identification efforts following an incident. Unfortunately, responses of
complex biological populations to any stimulus tend to be site specific.
A second need in operations is the development of more useful control measures
(analogous to MLSS, MCRT and F/M) for fixed film treatment technologies.
Although measurements of DO and slime thickness are acceptable performance
monitors, little positive control exists to respond to influent wastewater
changes. Recycle ratios and feeds are the only adjustments in trickling filter
operations, while RBC plants provide no control other than reversal of rotation
direction or the use of supplemental aeration for biomass control.
Inorganic chemical salts and polymers are now used extensively in POTWs for
improved settleability, sludge conditioning and odor control. The removability of
industrial pollutants, especially metals, by chemicals has been widely studied.
However, the effect of a sudden discharge of a priority organic on existing
chemical feeds is not well known and needs attention.
Toxicity Testing
The use of biological inhibition testing procedures for the identification and
tracing of industrial sources to POTWs should continue to grow in the future.
Before this technology is widely accepted and utilized by operations personnel,
low-cost portable units and in-line instrumentation will need to be commercially
6

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available. The automatic detection of inhibitory substances before reaching the
POTW would be a significant breakthrough in interference mitigation.
Additional research efforts should continue to be directed at correlating the
results of acute toxicity procedures with the more widely accepted fish bioassay
methods. Such correlations allow for routine toxicity testing without the
logistical problems and high costs associated with traditional biomonitoring.
Management Aspects
The final report of the Pretreatment Implementation Review Task Force (U.S.
EPA, 1985) indicated five general conclusions regarding the existing pretreat-
ment program:
1.	Pretreatment programs are perceived as too complex.
2.	Enforcement and consistent implementation of these programs is critical
to their success.
3.	Adequate financial resources are needed for proper implementation.
4.	Program success depends on a cooperative partnership between the Federal
and State government and the POTWs.
5.	Specific changes to the regulatory requirements were needed (and have
since been implemented).
Treatment plant and sewer authority management must properly implement their
pretreatment programs in order to satisfy the requirements of the regulations
and to eliminate interferences at their facilities. There is a need to identify the
perceived or actual stumbling blocks facing the POTW managers and to develop
programs to aid them in implementation and enforcement. A common problem
identified during the telephone survey and site visits was the political sensitivity
of pressuring industrial waste dischargers who are significant employers and
taxpayers in a community. Programs designed to educate both the industry and
municipal operator about the regulations and rationale for pretreatment could
prove beneficial.
7

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SECTION 3
LITERATURE REVIEW
To accomplish the efficient and thorough gathering of information on pollutants
which interfere with POTW operation, two literature search approaches were
utilized. The initial approach involved accessing several computerized technical
literature databases. The second approach involved studying pertinent litera-
ture:
1.	reviewed annually by the Water Pollution Control Federation (WPCF);
2.	presented at applicable technical conferences;
3.	categorized at year end in the Journal of the Environmental
Engineering Division (JEED) of ASCE; and
4.	compiled in the Revised Pretreatment Guidelines (JRB Associates,
1981a) and in a study by the Franklin Research Center
(Geating, 1981).
Prior to starting the literature review portion of the project, it was necessary to
establish a time period for the literature contained in the computer databases.
Such a constraint served to keep the number of citations down to a manageable
level, while at the same time did not duplicate the efforts of previous
researchers. The two documents listed in Item No. 4 above contain sizeable
bibliographies pertaining to the treatability and impact of pollutants in municipal
treatment facilities. Both reports utilized computerized searching techniques,
and in the case of the Franklin Research Center report, considered literature
dating back to 1914. A check on the breadth and depth of the references
indicates that the bibliographies contained in the abovementioned reports
provide complete coverage of the literature prior to 1980. The current effort
therefore limits the computerized database search to the time period from 1980
to 1985.
A list of eighteen appropriate databases available through the Dialog network
was developed and prioritized. The first, five databases were accessed and the
suitable reference abstracts were obtained and screened. The number of
citations generated by each database was as follows:
National Technical Information Service
Compendex
Engineering Meetings
Aqualine
Dissertation Abstracts
Total
932
666
1,054
100
	60
2,812
8

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With a large number of duplicate references being noted by several of the
accessed databases, and with no pertinent unique databases left unaccessed,
further computerized database searching was not pursued.
The second part of the literature review was designed to locate additional
references of interest to the study and to validate the computer-based search.
Cross checks were made to see if citations of interest obtained from the WPCF,
technical conferences and JEED searches were also included in the computerized
databases. Approximately 5,000 references were screened in the second
approach to the literature search.
As a final check of the literature search process, the resulting references were
scanned for the presence of several journal and conference articles known to be
important to this study. Based upon the positive checks, it was decided that the
literature search was successful and complete. The combination of all literature
search efforts resulted in reviewing nearly ®,000 reference titles. As a result of
"key word" limitations in the searching procedures, a large number of the
8,000 references reviewed were either not applicable to this project or were not
deemed sufficiently important to warrant futher investigation. Through careful
scrutiny, some 400 articles/reports were selected for potential comprehensive
review. Approximately 25 percent of these documents proved to be inappro-
priate to this study upon receipt of the full article, resulting in a final
bibliography numbering just over 300 references.
The selected articles 'and reports were distributed for review among ten
members of the Wastewater Department in JMM's Pasadena, California
headquarters. The literature review form shown in Appendix B was developed
and utilized by the reviewers for each reference read. This approach generates
more consistent information about each article, and provides a more efficient
transfer of data to the authors than if critiques were independently written by
the reviewers. Each docum- t reviewed was coded, so that the literature review
authors could easily refer back to the reference if they sought more information
than the form provided.
The literature review is divided into several categories and subcategories
according to treatment process. The major process categories with the number
of references reviewed in each are given below:
General Wastewater
32
Primary Treatment
5
Secondary Biological Treatment

General
7
Suspended Growth Processes
134
Fixed Film Processes
48
Advanced Treatment

Biological Nutrient Removal
11
Physical/Chemical Process
35
Sludge Processing

Treatment
15
Disposal
13
9

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GENERAL WASTEWATER
It is generally assumed that the sources of the contaminants causing process
upsets and interferences in municipal treatment are industrial wastewaters. In
an analysis of numerous surveys conducted over the last ten years at POTWs
across the country, JRB Associates (1981b) concluded that process upsets and
O&M problems were typically associated with industrial wastewaters. Specifi-
cally:
•	Approximately 80 percent of POTWs with O&M problems receive
industrial wastes.
•	Over 70 percent of the POTWs receiving industrial wastes implicated
the industrial flows as a source of the O&M problems.
© 65 percent of the operators at plants with permit violations attri-
buted those violations to industrial discharges.
•	84 percent of the POTWs sustaining upsets claimed the industrial
wastes contributed to the upsets.
Other conclusions were that smaller facilities (less than 5 mgd) were more
susceptible to interferences from industrial contaminants than larger plants, and
that a high incidence of upsets were attributable to wastewater discharge from
the food, electroplating, mechanical products and textile industries. Similar
conclusions could be drawn from a series of unpublished inspection reports
investigating the cause(s) of POTW permit non-compliance (JRB Associates,
1982-1984).
Some authors argue that industrial discharges are used as scapegoats by
municipal treatment plant operators for their O&M problems. Gray, et al. (1979)
ranked industrial loadings fifth on their list of ten factors contributing to O&M
problems in a survey of 120 Eastern, U.S. plants. In a similar survey of
50 western, U.S. facilities, Hegg, et al. (1980) concluded that plant operations
problems resulting from poor process control were unjustifiably blamed on toxic
inputs. The discrepancy between these conclusions and those of JRB Associates
(1981b) may stem from the fact that JRB chose POTWs with significant
industrial contributions, while Hegg, et al. and Gray, et al. focused their efforts
on organically and hydraulically underloaded facilities with generally insignifi-
cant industrial waste loads. In both of the latter studies, performance limiting
factors at activated sludge plants mainly resulted from inadequate process
control, while trickling filter problems commonly resulted from design deficien-
cies.
Some studies have focused on the characterization of the wastewater at specific
locations. Ongerth and DeWalle (1980) analyzed the influent at Metro Seattle
and found that although industries were contributing only 10 percent of the
10

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wastewater flow volume, it represented 20 percent of the organic load. They
also discovered that the concentration of toxic pollutants in the influent
increased in proportion to the industrial flows. Similar results were discovered
at the Moccasin Bend Plant in Chattanooga, Tennessee. Seventy-two of the
priority pollutants (including cyanide, zinc, chromium, phenol and toluene) are
present in the influent, representing 21 of the 37 EPA designated industrial
categories. Industrial wastewater constituted 50 percent of the dry weather
flow at the plant, but 65 percent of the influent BOD. lannone, et al. (1984)
studied the wastewater influent to 12 New York City plants where the industrial
contribution ranged from less than 1 percent to 8 percent by volume. In contrast
to the Seattle example, the authors found that only 13 of the 114 organic priority
pollutants were present in greater than 10 percent of the samples, and that the
major source of these organics wai from domestic or storm water svources4
Similar wastewater characterization was performed by Levins, et al. (1981) at
Cincinnati, St. Louis, Atlanta and Hartford. They found that although industrial
sources dominated the loading on the POTW, few toxic pollutants were found in
the wastewaters, and those present generally existed at low concentrations.
Two studies were funded by the U.S. EPA in an effort to quantify the contribu-
tion of toxicants from non-industrial sources. Hatl.away (1980) identified
common household uses for the priority pollutants, including a breakdown of
sources for each within the home (i.e., toilet flushing, laundry, kitchen sink,
etc.). The appendix contains lists of abbreviations, synonyms and trade names
for each of the 129 compounds on the priority pollutant list.
E.C. Jordan Company (1984) analyzed a series of storm events and discovered
that high concentrations of heavy metals (> 1 mg/1) and toxic organics (0.5 mg/1)
were sometimes present in combined sewer flows. Comparisons of these data
with dry weather flow analyses indicates that the stormwater contribution is
significant, but that the concentrations are still less than those present in typical
sanitary wastewater.
The U.S. EPA has previously sponsored research on the treatability and effects
of pollutants at POTWs using a combination of literature and actual plant data.
The three-volume Federal Guidelines for State and Local Pretreatment Programs
(U.S. EPA, 1977) included a summary of treatability and impact for a variety of
metals, conventional pollutants and organics. Wastewater processes considered
include primary sedimentation, activated sludge treatment (including nitrifica-
tion), trickling filters and anaerobic digestion. A series of useful figures is
presented indicating the concentration levels at which specific contaminants
produce no effect, are inhibitory or cause upsets in activated sludge, nitrifica-
tion and digestion. These guidelines were later updated and consolidated into a
two-volume, unpublished EPA report (JRB Associates, 1981a).
Perhaps the most comprehensive work done to date on toxic pollutants was the
publication of a five-volume Treatability Manual (U.S. EPA, 1981). This project
utilized the literature and treatment plant records to produce separate volumes
on treatability, industrial processes and descriptions, and treatment technol-
ogies. Excellent coverage of the literature pertaining to biodegradibility and
toxicity was provided by Geating (1981, Volume I). Volume II of that same
document develops a "permutated index" of chemicals in water from over
600 references published from 1974-79. While the index was not particularly
11

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useful to this project, the extensive bibliography provided 150 additional relevant
references to be considered for this review.
Process Comparisons
Six different treatment processes were subjected to 21 organics plus background
concentrations of five metals in order to compare removal efficiencies of the
five alternatives with the conventional activated sludge process acting as a
control (Hannah, et al., 1985). Suspended growth systems (lagoons) proved to be
the best alternatives, followed by high rate trickling filters and then physical-
chemical processes. Smith, et al. (1981) subjected two complete-mix activated
sludge units (one with powdered activated carbon addition) and a rotating
biological contactor (RBC) to shock loadings of pesticides. The RBC unit proved
to be more stable with lower oxygen requirements, and not subject to the sludge
bulking which occurred in activated sludge treatment. However, the testing was
performed using non-acclimated bacterial cultures.
Some research compares suspended growth and fixed film processes for their
reliability and stability in treating specific wastewaters. Stracke and Baumann
(1977) set up a side-by-side pilot scale comparison of trickling filter and
activated sludge treatment at a chemical manufacturing industry which was
causing a POTW to violate their NPDES Permit for BOD, TSS and NH3.
Although the trickling filters were easier to operate and not as susceptible to
upsets from shock loads, the long detention times required for treatment made
the activated sludge system a more practical design alternative.
Coal derived wastewaters containing phenols, cyanides, thiocyanates and
ammonia have been analyzed by Holladay, et al. (1978) and Medwith and
Lefelholz (1982). In the former reference, a continuous stirred-tank bioreactor
(CSTBR), a packed-bed bioreactor (PBBR) and a fluidized-bed bioreactor (FBBR)
used acclimated cultures to degrade the waste. The results indicate:
•	good biodegradation of phenols and thiocyanate in all reactors
•	phenol degradation rates decreased from FBBR > PBBR > CSTBR
•	the CSTBR is most vulnerable to shock loadings
•	the PBBR tended to develop excess biomass.
The later study tested a bench-scale, hybrid, suspended growth-fixed film
reactor using coal dust as an inert support medium in a suspended culture of
organisms acclimated to the wastewater. Simultaneous carbonaceous and
nitrogenous oxidation occurred, with improved sedimentation resulting from the
coal dust addition. Use of powdered activated carbon (PAC) in lieu of the inert
coal did not improve the treatment.
Austin, et al. (1981) found the oxygen activated sludge process to be more stable
and flexible, with better settling characteristics than air activated sludge when
treating Carson, California wastewater in pilot reactors. Both systems met
discharge standards for all parameters except chromium, nickel and zinc. The
air system accomplished nitrification (the oxygen system did not), but suffered
from sludge resuspension due to denitrification in the final clarifier.
12

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Gaudy, et al. (1982b) compared the behavior of 24 organic compounds dosed at
5 mg/1 into settled municipal sewage in batch reactors. Only pentachlorophenol
and 2-chlorophenol caused increases in effluent COD. Eight of the compounds
were then tested in continuous flow reactors with no increase in COD, but phenol
and methylene chloride caused effluent TSS to rise. Wher; four of the organics
were treated by extended aeration, improved effluent quality existed in each
case, with no evidence of pass through.
Conventional activated sludge and extended aeration were compared by Kincan-
non, et al. (1981) in bench scale reactors treating varying dosages of phenolics.
At 5 mg/1 there was no increase in effluent COD, but slightly higher TSS values
in conventional treatment. However, as the phenol concentrations increased, the
effluent COD and TSS also increased in the effluent. The extended aeration
process was affected at all levels of dosing, but generally produced a higher
quality effluent than the conventional system.
Niku, et al. (1981) studied over 40 activated sludge wastewater treatment plants
for general reliability, stability and variability. The following generalities for
activated sludge process variations were found: (1) step feed and step aeralion
processes provide the best year-round BOD removal efficiency, (2) conventional
activated sludge provides the best total suspended solids removal, (3) completely
mixed activated sludge performance is lower than the previous three variations,
and (4) contact stabilization provides the lowest performance of all.
Some research efforts have compared RBCs with other biological processes.
Lytle (1984) determined that operating costs were lower for RBCs than either
trickling filters or activated sludge systems when treating photofinishing waste-
waters. An acclimated RBC fed liquid detergent effluent (MBAS = 2.8 mg/1)
provided comparable treatment to that of an aerated lagoon, as long as the
wastewater temperature remained above 15°C (Lense, et al., 1978).
Toxicity and Inhibition
The most relevant literature for this study are those references pertaining to the
impact of pollutants on POTW operations. Pajak, et al. (1977) lists the six
general ways in which biological treatment process upsets are manifested as:
•	direct toxicity to organisms
•	inhibition of biological processes
•	exertion of BOD after treatment (e.g., in receiving stream)
»	high effluent COD caused by refractory material
•	disruption of sludge treatment
•	high oxygen demands resulting in a poor bioreaction environment
The report further develops a "Hazardous Materials Effects Matrix", including an
alphabetical listing of chemicals with inhibition/toxicity and treatability dat?..
Russell, et al. (19S3) reviewed the literature on inhibition of the activated
sludge, nitrification and anaerobic digestion processes by metals and organics.
They noted some disagreement with previous publications concerning threshold
inhibitory effect concentrctions. The authors concluded that generally organic
13

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toxic pollutants do not occur at concentrations that would affect POTW
operations, but that metals are often found above threshold levels in influent
wastewaters. The form of the metals is considered as important as total
concentration when assessing the impact on treatment processes. In the
literature survey section of another article (Yost, et al., 1981), trickling filters
where shown to be loss sensitive to he.ivy metal shock loadings than activated
sludge systems. In their work at the Kokomo, Indiana plant, the authors noted
high removals of metals, particularly for chromium (98 percent), iron
(98 percent) and lead (95 percent). The metals were determined to be predomi-
nantly from industrial point sources throughout the sewer system, but the highly
variable levels did not affect their removal.
An advanced treatment pilot plant was used to treat Indianapolis wastewater
containing between 0.15 and 1.0 mg/1 of a variety of organics in a study
performed by Cain, et al. (1983). Phenols at 1 mg/1 caused a 10 percent to
20 percent, reduction in nitrification, and 0.15 mg/1 of pentachlorophenol
destroyed the nitrification process, but no other inhibitory or toxic effects were
realized. A number cf typical ca,':. Cu > Zn > Cd > Cr > Ni.
Patterson, et al. (1983) developed similar conclusions in their bench scale work
to those of Lester, v'th metals removals ranging from 14 to 41 percent. A
significant contradiction, however, is their ranking of metals removability which
they show to decrease from Ni > Fe > Pb > Cr > Al > Cd > Cu > Zn. Having
14

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TABLE 1
COMMON TREATMENT PLANT UPSETS
from JRB Associates (1981b)
Cause
Effect
Low pH
Solids or viscous pollutants
High concentrations of volatiles
Organic or hydraulic overloads
Heated discharges
Presence of toxics
Coj *-osion of pipes and equipment
Flow obstruction
Explosion/fire hazards
Process upsets
Altered biological activity
Inibition of biological activity
most readily removed in primary treatment is inconsistent with nearly all other
authors, who typically indicate nickel to be one of the least removable.
Pilot scale testing on th j removal of 13 metals from the Mill Creek (Cincinnati)
wastewater was conducted by Petrasek and Kugelman (1983). Removals ringed
from 15 to 40 percent for most elements except arsenic, calcium and magne-
sium, which demonstrated negligible partitioning in the clarifier. Relative
concentrations of metals found in the waste activated sludge were two to five
times greater than in the primary sludge, indicating stronger removals of metals
in secondary treatment, Nielsen and Hrudey (1983) studied the fate of metals at
the Gold Bar Plant in Alberta (Canada), and found that with the exception of
cadmium, most of the removal took place in primary sedimentation. This
apparent contradiction with the work of Petrasek and Kugeltncn-i results from the
particulate form of the metals in the Gold Bar influent wastewater. Low overall
removal of zinc (< 55 percent) contradicts results obtained at other facilities.
Organics -- A few authors have considered the fate of priority organics in
primary clarifiers. Ongerth and DeWalle (1980) observed tha» Lhe high molecular
weight compounds were more easily removed than the smaller compounds,
presumably due to their adsorption onto the settling solid particles. Petrasek,
et al. (1983) noted that removals tended to be variable between classes of
compounds, but consistent within a particular class. Two references (Mclntyre,
et al., 1981b; Gutierrez, et al., 1984) have looked at the behavior of PCB's and
other organochlorine insecticides in primary sedimentation. Both papers indi-
cated a direct relationship between suspended solids removal and the removal of
these organics. M .rlntyre, et al. found that comparable removals (50-75 percent)
of suspended solids and insecticides existed at the Sandford V/orks in Oxford,
England. Gutierrez, et al. discovered that optimizing suspended solids removals
in a pilot scale application also resulted in optimum removals of PCB and other
organochlorines. The authors also nottri that organics removals were inversely
proportional to hydraulic loading, but were not affected by varying concentra-
15

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tions of suspended solids, surfactants (MBAS) or fats, ^ils and greases (FOG). In
contrast to the abovementioned results with insecticides, Hill, et al. (1985) found
insignificant removals of chlorophenoxy herbicides in primary clarification
during pilot scale testing.
Case Studies -- In a 30 day study (E.C. Jordan, 1982) of the Moccasin Send
Wastewater Plant, organics and metals removals averaged less than 20 percent in
primary treatment, compared with 30 percent removal of suspended solids.
A one-week study (U.S. EPA, 1977b) of the 80 mgd T.E. Maxson plant in
Memphis, Tennessee uncovered numerous problems with primary treatment.
High influent BOD and TSS values resulted from the discharges from
162 industries, particularly brewery and food-processing wastes. Sludge buildup
in the clarifiers produced septicity, bubbling and excessive solids carryover.
Lowry and Chwirka (1983) reported on the impact of papermill wastewater on a
3 mgd combined treatment facility in Brewer, Maine. The industrial flows were
responsible for large flow and TSS fluctuations, plus occasional high temperature
flows resulting from mill boilouts and washups. Such variations resulted in
stratification and short-circuiting in the primary clarif?er. Polymer addition to
the clarifier influent and by-passing the domestic fraction of the wastewater
around the primaries directly to the aeration basins have proven successful in
mitigating the upsets.
SECONDARY BIOLOGICAL TREATMENT
This section of the literature review is divided into two major treatment
categories: suspended growth and fixed film processes. Activated sludge is the
dominant secondary biological treatment method studied in the literature, with
the addition of powdered activated carbon to activated sludge, lagoons and
anaerobic reactors also considered in this review. Despite their relatively recent
entrance into the marketplace, more research has been performed on the
treatability and impact of various pollutants on rotating biological contactors
(RBCs) than any other fixed film treatment method. Other processes covered
are trickling filters (including biotowers), aerated submerged filters and anae-
robic filters.
Some studies have considered the biodegradability of pollutants irrespective of
the treatment system. Bedard (1976) focused his attention on the inherent
treatability of numerous organic compounds based on the results of bench-scale
testing. Compounds were assigned a numerical refractory index (R.I.) indicating
their potential for total biodegradation, or a biological interference value (B.I.V.)
based on the degree of interference with the biological system. Oxygenated
compounds such as the glycols demonstrated a high degree of biodegradability
(high R.I.), while the PCB's and halogenated aliphatics (notably vinyl chloride)
show low R.I. values. Similarly, aliphatics (chloroform) and phenols (dichloro-
phenol) produced the largest B.I.V.'s, indicating a tendency toward causing
interference. Tabak, et al. (1981) used static culture flask biodegradation
screening methods to determine degradability and rate of acclimation for 96
compounds. The phenolics, phthalate esters and naphthalenes demonstrated
16

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significant degradation and rapid acclimation, while PCB's and organochlorine
insecticides were poorly degraded with variable acclimation ra as.
Baxter, et al. (1975) exposed prepared cultures of microorganisms to varying
concentrations of numerous PCB compounds alone and in combination with one
another. They observed that:
•	the presence of PCB reduced the rate of biodegradation.
•	the degradation rate is inversely proportional to the number of
chlorine atoms per molecule.
•	the degradation rate may increase when the PCB compounds are
present in a mixture of compounds.
Two studies considered the biodegradation of polyethylene glycols. Haines and
Alexander (1975) determined the rate of degradation to be inversely proportional
to molecular weight. The prepared cultures used in the research were able to
fully degrade ethylene glycol in 2 days, di, tri, and tetra-ethylene glycol in
5 days, and the polyethylene glycols (PEG) up to a molecular weight of 20,000
only after extended time periods. The mechanism for PEG degradation is
apparently the depolymerization of the compounds by extracellular enzymes, at
which time the simpler molecules can be absorbed through the cell membrane.
Similar results were obtained by Watson and Jones (1977) using bacterial strains
isolated from sewage. The three strains used successfully degraded PEG up to a
molecular weight of 4000. The authors also noted that biodegradation was
frequently more rapid in the presence of other nutrients.
DiGeronimo, et al. (1979) studied the utilization of chlorobenzoates by sewage
bacteria. They observed that all configurations of chlorobenzoate and
3, 4-dichlorobenzoate were readily degraded, but that 2, 4-dichlorobenzoate and
2, 3, 6-trichlorobenzoate were not metabolized.
Suspended Growth Processes
Activated Sludge —
In one of the earlier studies on the degradability of organics, Pitter (1976)
outlined the three factors affecting treatability as:
•	physical-chemical (temperature, pH, solubility, DO level)
•	biological (microbial culture)
•	chemical (pollutants)
The research tested 94 aromatic, 15 hydroaromatic and 14 aliphatic compounds
in a bench scale adapted activated sludge.
The mechanisms for removal of organics in the activated sludge process were
outlined by Kincannon, et al. (1983) as:
•	air stripping (volatilization)
•	biodegradation
•	adsorption onto sludge floes
•	chemical oxidation
17

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The authors performed bench scale testing on a synthetic wastewater spiked with
varying concentrations of 15 toxic pollutants. The acclimated cultures present
in the complete-mix system were able to achieve greater than 99 percent
removal for all compounds except tetrachloroethane, nitrobenzene and
2, 4-dichlorophenol. In general, biodegradation was the prevalent mechanism for
the oxygenated, nitrogen and phenolic compounds, while the halogenated hydro-
carbons were removed by stripping. Aromatic compounds were removed by a
combination of stripping and biological oxidation, leaving sorption as an insignifi-
cant mechanism. The authors also investigated the effects of ozone on
treatability, and found it can have a significant but inconsistent impact. For
example, 1, 2 -dichloropropane became biodegradable in the presence of ozone,
while acrylonitrile demonstrated reduced biodegradability. In similar bench
scale studies (Lawson and Siegrist, 1981) run at food-to-microorganism (F/M)
ratios less than 1.0, biodegradation rates were greater than those observed at
higher F/M values. Air stripping rate constants were found to be sensitive to
temperature changes, and sludge sorption was a significant mechanism for
dioctyl phthalate only.
A few studies have measured removals of contaminants by the activated sludge
process. Bishop (1982) determined the total removal (including primaries) to be
greater than 90 percent for organics, and between 60 and 80 percent for metals.
In E.C. Jordan's (1982) study at Moccassin Bend, the activated sludge removed
74 percent of the metals, 80 percent of volatile organics, 69 percent of the acid
extractables and 62 percent of the base neutral compounds. Neiheisel, et al.
(1982) tested for acute aquatic toxicity on the influent, primary effluent and
final effluent of a plug flow activated sludge pilot plant. Fifty ug/1 of
16 priority organics were added to a combined municipal/industrial wastewater
feed, but they did not alter the toxicity. The activated sludge reduced the
toxicity level from the primary effluent to the final effluent, while insignificant
changes in toxicity occurred through the primary clarifier.
Conventional Pollutants -- A study by Manickan »nd Gaudy (1983) compared the
response of an activated sludge system to ¦ rp- ic, hydraulic and combined
organic-hydraulic shocks of the same total ma^. loading. After dosing six-fold
mass loading increases, it was determined that the three types of shocks
produced three different operational disruptions. Hydraulic and organic-hydrau-
lic shock produced equal increases in total effluent COD, but the disruptions
were primarily due to decreased suspended solids removal and soluble COD
leakage, respectively. Organic shock resulted in the greatest effluent COD
increase, but in terras of total mass leakage, hydraulic shock was most
disruptive. Predictive kinetic equations did not adequately describe the disrup-
tion of solids or substrate concentration. Selna and Schroeder (1978) reported
similar changes to kinetic parameters for organic shocks of five hour durations.
Only minor increases in effluent suspended solids were reported, but noticeable
increases in effluent COD values were observed for increased organic loading
(three times normal) at mean cell residence times of five and ten days.
George and Gaudy (1973b) showed that a bench-scale activated sludge unit could
withstand substantial pH shock and concluded that full scale units could
accommodate a change of 1.0 pH unit without a not:,;eable decrease in organic
removal efficiency. A study of the effect of the dissolved oxygen (DO) level on
18

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the activated sludge process showed no relationship between DO concentrations
and COD removal efficiency, respiration rate or solids yield (Thabaras and
Gaudy, 1969). The response of the activated sludge process to organic shock
loads was independent of DO as well. From a baseline temperature of 25°C, the
activated sludge process responded more favorably to increases in temperature
than decreases (George and Gaudy, 1973a). In once-through reactors, eight hour
hydraulic residence times were more favorable than four hour residence times.
In utilizing a synthetic substrate (BOD=200mg/l) which included readily biodegra-
dable synthetic surfactants, inconsistent COD removal was observed until
2-5 mg/1 of phosphate was added (Painter and King, 1978). Before addition of
the phosphate, the activated sludge exhibited signs of bulking as well. Tokuz and
Eckenfelder (1979) showed that their bench-scale activated sludge system was
not inhibited by the addition of sodium chloride and sodium sulfate salts up to
the levels 35 g/1 and 30 g/1, respectively. It appeared that the reactor solids
level and the number of filamentous organisms were proportional to the salt
concentration, while the number of protozoa was inversely proportional to the
salt concentration. However, no sludge bulking was observed in the range of salt
concentrations mentioned above. During the acclimation of an activated sludge
unit to a substrate with the salinity of sea water, the sludge volume index (SVD
decreased, but at the same time an increase in the number of pinpoint floes
caused serious degradation of the supernatant (Imai, et al., 1979).
Studies of the biodegradation of cationic surfactants in activated sludge were
conducted by Fenger, et al. (1973) and Sullivan (1983). Fenger showed that
tetradecyldimethylbenzylrammonium chloride (TDBA) was reduced by up to
75 percent at influent levels as high as 20 mg/1 in acclimated cultures, but
unacclimated activated sludge was inhibited by TDBA levels as low as a few
mg/1. Sullivan showed that ditallowdimethyl-ammonium chloride (DTDMAC) was
biodegradable in conventional and extended aeration activated sludge, with
ultimate biodegradation being more rapid in extended aeration. DTDMAC
removal also appeared to be the result of sorption/precipitation mechanisms.
Removal of a nonionic surfactant (NEODOL 45-7, Shell Chemical Corporation)
was 90 percent complete in a full scale contact stabilization activated sludge
treatment plant with influent concentrations as high as 10 mg/1 (Sykes, et al.,
1979). Cook (1979) investigated another nonionic surfactant (DOBANOL 45-7)
that showed rapid and complete biodegradation by activated sludge micro-
organisms at concentrations up to 500 mg/1.
In a study of biodegradability by prepared activated sludge cultures, Gerike,
et al. (1978) concluded that quaternary ammonium salts could be degraded in
acclimated activated sludge treatment plants in concentrations up to 15 mg/1. In
another biodegradation test, Novak and Kraus (1973) reported that the degrada-
tion of saturated long chain fatty acids was proportional to their solubility. The
degradation of unsaturated long chain fatty acids was independent of chain
length or degree of saturation.
The T.E. Maxson plant in Memphis suffers from high influent BOD, TSS and FOG,
the presence of pesticides and other toxic organics, plus rapid pH fluctuations
(U.S. EPA, 1977b). Consequently, a one-week EPA study discovered numerous
problems with the contact stabilization process used for secondary treatment,
including:
19

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•	low DO in the contact basins
•	high F/M
•	growth of filamentous bacteria
•	poor sludge settling
•	foul odors
Their recommendations were to add an additional air compressor to maintain the
DO levels between 1.0 and 2.0 mg/1 during peak flow periods, and to increase the
SRT.
Phenols and Cyanides -- A number of studies reported generally successful
treatment of phenolic bearing wastewaters by acclimated activated sludge
(Dechev and Matveena, 1977; Neufeld and Valiknae, 1979; Khararjian, et al.
1979; Luthy and Jones, 1980; Kim and Armstrong, 1981; Luthy, 1981; DeWalle,
et al., 1982; Gaudy, et al., 1982a; and Rozich and Gaudy, 1985). DeWalle, et al.,
presented records from 25 treatment plants (locations not specified), nearly all
of which employed the activated sludge process. Activated sludge was shown to
exhibit generally good removal of phenolics, with methylated phenols showing
greater removal than chlorinated phenols. Particularly poor removal was shown
for 2-nitrophenol, 2-chlorophenol and 2,4-dichlorophenol.
The response of an activated sludge process utilizing a phenolic substrate to
quantitative shock loadings was studied by Rozich and Gaudy (1985). An
acclimated pilot-scale plant showed no substantial changes in operation when the
phenol concentration was stepped from 500 mg/1 to 1,000 mg/1, but eventual
washout occurred in stepping from 1,000 mg/1 to 2,000 mg/1. Radical changes in
biomass characteristics occurred during the second shock, the biomass becoming
viscous, clumpy and highly dispersed. The first indication of process failure was
a white foam which collected at the top of the aeration basin.
Dechev and Matveena (1977) showed that the rate of oxygen uptake is proportio-
nal to the phenol concentration in activated sludge. Khararjian, et al. (1979)
demonstrated that the oxidation rate was independent of SRT in the range of 3
to 15 days, but that high SRTs were required to treat low COD and phenol
concentrations. The authors also showed effective removal of phenol to below
0.1 mg/1, with good sludge settling characteristics.
A study of thiocyanate inhibition of phenol biodegradation showed that the
effect was particularly significant when low effluent phenol levels were desired
(Neufeld and Valiknae, 1979). A design and operation equation was developed
relating sludge age (SRT), effluent phenol level, thiocyanal^ level and tempera-
ture. In a treatability study, the substrate utilization rate (rsu) for a phenol
substrate decreased as pH deviated from neutral and as salinity increased (Kim
and Armstrong, 1977). In contrast, nitrogen and phosphorus levels did not affect
rsu. Phenol decomposition resulted in a considerable decrease in pH, so that the
buffering capacity of the wastewater was the most important factor in determi-
ning treatability.
Capestany, et al. (1977), treating a mixture of phenol, toluene and benzoic acid
observed good phenol and BOD removal (>97 percent) only after sufficient sulfur
was added to satisfy a BOD:N:P:S ratio of 1000:5:5:5. Three studies investigated
20

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the activated sludge treatment cf chlorophenols. Broecker and Zahn (1977)
showed that activated sludge, treating an industrial waste, successfully
acclimated to the addition of 5 mg/1 of 3,5-dichlorophenol (DCP) with only a
slight, temporary lowering of wastewater biodegradation. Higher DCP levels
were not treated as successfully and the authors suggested 5 mg/1 as the toxicity
limit. Edgehill and Finn (1983) and Moos, et al., (1983) both addressed the
activated sludge treatment of pentachlorophenol (PCP). In the former article,
activated sludge (without recycle) required seven days to acclimate to
40-120 mg/1 PCP and showed poor response to PCP shock in an acclimated
culture. The latter article reported that PCP concentrations as low as 250 ug/1
inhibited PCP biodegradation, but that the activated sludge could be acclimated
to 20 mg/1 PCP or higher. PCP biodegradation was proportional to biomass
concentration, while sorption and volatilization were not significant removal
mechanisms.
Lordi, et al. (1980) studied six wastewater treatment plants for cyanide problems
in the Metropolitan Sanitation District of Chicago. They found variable removal
efficiencies with influent cyanide concentrations varying from a low of 0.07 mg/1
in domestic plants to 0.40 mg/1 in industrial plants. In general, 0.67 to
0.80 pounds of cyanide were removed per million gallons of waste treated.
Gaudy, et al. (1982a) estimated a maximum of 60 percent of the cyanide removal
was by air stripping at influent levels of 20 mg/1. Raef, et al. (1982) ranked the
cyanide removal mechanisms in decreasing importance at neutral pH as: air
stripping > biological metabolism > bio-adsorption > chemical reaction with
substrate. Neufield, et al. (1981) showed virtually complete thiocyanate
removal by acclimated activated sludge at thiocyanate levels of 1,000 mg/1 in
the pH range of 5-7. At higher pH values or sludge ages less than six days,
significant process instability resulted. The critical sludge age for thiocyanate
biodegradation in this study was 4.14 days.
A substantial amount of work has been done on the treatment of coal coking and
coal gasification wastewaters, which are characterized by high concentrations of
phenols, cyanide and thiocyanates. Luthy (1981) reviewed the literature con-
cerning treatment of these wastes by activated sludge. It was indicated that
under proper conditions of acclimation, good COD, BOD, phenolics, ammonia-
nitrogen and cyanide removal could be expected. Low microbial yield was a
typical characteristic of coal byproduct wastewater treatment, resulting from
inhibitory constituents in the wastewater. Single stage nitrification was possible
under controlled conditions.
Jones, et al. (1984) studied the biological treatment of a high-strength coke plant
ammonia liquor where operation of the activated sludge system led to filamen-
tous growth. A pH increase, exposure to hydrogen peroxide, 4 percent wasting of
the mixed liquor and elevated operation temperatures (42°C) were all attempted
to mitigate filamentous effects. Only the l?.st response was successful, although
long term effects were not studied. Luthy and Jones (1980) utilized a similar
wastewater in a completely-mixed activated sludge unit, resulting in good
removal of phenolics, thiocyanate and COD at a mean cell residence time of
40 days. In the absence of substantial nitrification, the effluent ammonia-
nitrogen was higher '.han the influent due to degradation of the thiocyanate and
release of ammonia. Another study of a similar waste showed good phenol and
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COD removal for an SRT of only 6.4 days when preceded by lime precipitation,
ammonia stripping and solvent extraction (Hung, et al., 1981).
Metals -- Numerous studies dealing with the relationship of metals and the
activated sludge process have been reported. Concentrations which reportedly
inhibit the activated sludge process and reduce metal removal efficiency by
activated sludge vary widely for most metals, but are remarkably similar in some
cases. The wide range of reported values can be attributed to a number of
factors including varying metal forms and solubilities, metal complexation and
competition, characteristics of the substrate and activated sludge biomass, and
process variations and conditions.
A number of references deal primarily with removal efficiencies of metals in the
activated sludge process (Nielsen and Hrudey, 1983; Rossin, et al., 1982; Sterritt
and Lester, 1981; Petrasek and Kugelman, 1983; Lester, 1983; and Patterson,
et al., 1983). In general, the studies agree on the broad removal efficiency
classifications presented in Table 2.
In most cases, the studies used to construct Table 2 utilized acclimated
activated sludge and showed that the activated sludge process is at least as
important as primary sedimentation in metals removal. Due to sludge recycle,
metals concentrations are consistently higher in activated sludge than in the
primary clarifier sludge.
Sterritt and Lester (1981) and Rossin, et al. (1982) showed that heavy metals
removal varied with SRT for those metals effectively removed by activated
sludge (Cd, Cr, Cu, Pb, Zn). Maximum affinity of the metals for the biomass
occurred at SRTs of 9-12 days, but maximum removal occurred from 12-16 days,
indicating the increased mixed liquor suspended solids (MLSS) more than offset
the metal's lower biomass affinity. Both studies observed Pb removal to be
proportional to suspended solids (SS) removal, as was Cr, Ni and Zn removal
according to Rossin. Sterritt and Lester reported Ag, Cu, Ni, and Zn removal to
be proportional to COD removal. The study by Rossin, et al., and another by
Nielsen and Hrudey (1983) indicated the ratio of soluble metal to total metal
increased as most metals passed through the activated sludge plant, with the
effluent being predominantly in soluble form.
Studies by Nelson, et al. (1981) and Patterson, et al. (1983) both showed that
adsorption isotherms adequately represented the distribution of metals between
the solid biomass phase and the solution phase. In the Patterson, et al. study,
sorption of seven metals in activated sludge mixed liquor ranged from a low of
8 percent to a high of 98 percent with the following sorption ranking:
Fe < Ni < Zn < Cd < Cr < Cu < Pb. A metals distribution model and full system
metals removal model were developed. Nelson, et al., determined that the
equilibrium distribution of metals between solids and solution was affected
primarily by physical-chemical factors and not by biological transport processes.
pH was the single most important factor influencing the chemical speciation of
metals and their solids-solution distribution.
After studying the inhibition of the activated sludge process by several metals,
Kang, et al. (1981) found that chromium was a fairly sensitive overall indicator
22

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Table 2
Metal Removal Efficiency by Activated Sludge
Metal	Removal Efficiency
Ag	Fair
A1	Poor
As	Poor
Ca	Poor
Cd	Good
Co	Poor
Cr	Good
Cu	Good
Fe	Good
Mg	Poor
Mn	Fair
Mo	Poor
Ni	Poor
Pb	Fair-Good
Zn	Fair-Good
Poor = < 20% Fair = 20-50% Good = >50%
Table 3
Metal Concentrations Inhibiting the Activated Sludge Process
Metal
Concentration (me/1)
Cd
4.0 - 5.0
Cr
1.0 - 20
Cu
0.7 - 1.0
Ni
1.0 - 5.0
Pb
0.1 - 1.0
Zn
2.5 - 20
Hg
1.0 - 2.5
Co
<5.0
V
20
23

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uf the occurrence of heavy metals in a waste stream. Additional studies on
treatability of metals and metal inhibition of activated sludge were also
conducted by Sujarittanonta and Sherrard (1981), Bagby and Sherrard (1981),
Weber and Sherrard (1980), Petra^ek (1981a, 1981b, 1981c), Bieszkiewicz and
Hosezowski (1978), Robins and Green (1974), and Kunz, et al. (1976). Volesky,
et al. (1977) reviewed the literature concerning the effects of metallic species
on the performance of biological treatment systems. Table 3 presents a
compilation of metals inhibition data f.rom the previous ten references. Inhibi-
tion is variously defined as causing an increase in effluent COD or suspended
solids, decreasing sludge settleability, or a combination thereof. As defined,
inhibition does not include inhibition of nitrifying organisms. The values
reported in Table 3 are in general higher than values listed as inhibitive by EPA
(JRB Associates, 1981a).
In reviewing the literature, Volesky, et al. found the following general relation-
ships to be true:
•	For a given metal ion concentration, a decrease in sewage strength
results in lower organic removal efficiency.
•	Increased metai ion concentrations result in lower organic removal
efficiency and longer process recovery times.
•	Inhibitory concentrations of metals are proportional to the MLSS
concentration.
•	Some metals appear to behave independently of others (when in
mixtures) in the activated sludge process.
•	The order of increasing toxicity to activated sludge is:
Cr(VD < Co < Zn < Cd < Cr(m) < Cu < Ni.
Lester (1983) drew many of the same conclusions in another literature survey.
He concluded that metal toxicity depends on the following six factors: metal
concentration, the form of the metal, species of organisms, suspended solids
concentration, sludge age and concentration of other cations.
Morozzi and Cenci (1978) compared the toxicity levels of some metals to that of
their tetracyanide salt complexes in activated sludge. The results showed:
cadmium and zinc complexes to be more toxic than the elemental form, nickel
metal toxicity was higher than the corresponding complex and no difference in
the effect of mercury and the corresponding tetracyanide complex. In contrast,
Cenci and Morozzi (1977) found no evidence of inhibitory differences between
cadmium and its corresponding tetracyanide complex at the 0.5 to 2.0 mg/1 level.
This inconsistency was suggested to be a result of higher MLSS in the 1978 study.
Webber, et al. (1977) showed that acclimated activated sludge could accommo-
date continuous boron concentrations up to 150 mg/1 with no decrease in COD
removal efficiency. The fate of the boron was not discussed, but boron
pretreatment guidelines at the time suggested only 1 mg/1 of boron as being
inhibitory. The organotin compound, tributyl tin oxide (TBTO), was treatable in
acclimated and unacclimated activated sludge at levels up to 100vjg/l and 25]jg/l
respectively (Argaman, et al., 1984). Activated sludge exposed to TBTO showed
less biomass diversity compared to control sludge.
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Two studies concerning the effect of nickel on the activated sludge process
found that increased substrate concentration and increased SRT were mitigating
responses to inhibiting nickel concentrations (Sujarittanota and Sherrard, 1981;
Bagby and Sherrard, 1981). The latter article showed the same relationship for
cadmium. Kao, et al. (1982) found that in the presence of the chelating agent
EDTA, cadmium uptake into the biomass was an order of magnitude less than
without EDTA, and the soluble portion of cadmium increased. A pilot-scale
study of cadmium using municipal sewage showed some cadmium breakthrough
into the effluent at influent concentrations as low as 2 mg/1, but activated
sludge inhibition did not occur until influent concentrations were greater than
4 mg/1 (Petrasek, 1981c). At higher cadmium concentrations (>8.0 mg/1), large
decreases in protozoa populations and sludge settleability occurred.
Casey and Wu (1978) found that cadmium and copper (and presumably other
metals) were more readily adsorbed to activated sludge biomass under
phosphorus-limited conditions than under normal operating conditions. Optimum
COD to phosphorus ratios depended on the metal involved.
Henney, et al. (1980) documen' id an accidental spill of 225 kg of chromium (VI)
to the Mankato, Minnesota wastewater treatment plant that resulted in a
maximum aeration basin concentration of 10 mg/1. By the day after the spill,
the respiration rate had dropped by a factor of three, free swimming protozoa
disappeared from the aeration tank and stalked ciliates were noticeably reduced.
Recovery was fairly rapid however, with effluent suspended solids levels
returning to normal after another day. BOD and COD removal efficiency
decreased for three days (from 89 percent to a 76 percent low) and returned to
normal in three weeks. The greater part of the Cr(VI) passed through the plant,
being removed only to the extent that it was reduced to Cr(ffl). The highly
insoluble Cr(IH) remained largely adsorbed to the biomass but did not appear to
be harmful to the activated sludge in moderate amounts. The first indication of
plant problems after the nightime spill was a characteristic (chromium) yellow
coloration of the plant wastewater.
Muttamara and Islam (1983) studied the activated sludge treatment of a tannery
waste high in chromium. They found COD removal will remain unaffected if the
food to microorganism ratio (F/M) is j10.?.5, with a metal to biomass ratio
£. 0.005. They found lime addition improved sludge settleability and reduced
toxic effects by causing precipitation of chromium.
Petrasek (1981b) found that mercury partitions strongly to the activated sludge
mixed liquor. Design and operation equations were developed con-elating Hg
levels in the influent and effluent with return activated sludge concentrations,
MLSS and primary sludge concentration. In a similar study, lead was also :ound
to partition strongly to the mixed liquor (Petrasek, 1981a).
A study by Mirzadeh, et al. (1977) investigated the effect of sodium bentonite
(clay) and ferric chloride on the activated sludge treatment of wastewater. It
was concluded that additions of sodium bentonite (0-500 mg/1) and ferric
chloride (0-200 mg/1) in the presence of sodium bentonite (100 mg/1) were
ineffective in improving an unstable activated sludge system.
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Other Organics — A comprehensive investigation of the fate of 22 toxic organic
compounds in an activated sludge treatment plant was conducted by Petrasek,
et al. (1983). Four pesticides, three phenols, six phthalates and nine polynuclear
aromatic hydrocarbons were dosed in municipal sewage at approximately 50 ug/1
each. Ninety-seven percent removal occurred for all compounds except lindane,
bis-(2-ei.hylhexyl)-phthalate, di-n-butyl-phthalate and pyrene.
Klecka (1982) showed that methylene * hloride rapidly degraded to CO^ and CI in
acclimated activated sludge. The rate of biodegradation was determined to be
twelve times greater than the rate of volatilization. Unacclimated activated
sludge did not successfully degrade methylene chloride. Vaicum and Eminovici
(1974) looked at the effect of Lindane on activated sludge characteristics and
found no effect at or below 5 mg/1 (Lindane), but found reduced COD removal,
biomass protein levels and enzymatic activity at Lindane levels of 10 mg/1.
Ishikawa, et al. (1979) investigated the removal of organic acids by r.cclimated
activated sludge. Acetic, propionic and butyric acid were removed at the rate of
35.9, 23.1 and 29-3 mg acid/gm MLSS/hour, respectively. Lau (1978) studied
process stability and removal efficiency of an activated sludge system treating
various aromatic acids. Two or three stage aeration provided much better
stability in dealing with quantitative shocks than did conventional single-stage
aeration.
Methyl alcohol and ethylene glycol did not affect an acclimated activated sludge
process at concentrations up to 1500 mg/1 and 200 mg/1, respectively
(Bieszkiewicz, et al., 1979). Concentrations above those levels caused reduced
biodegradation and poorly settling sludge. Aircraft de-icing fluid (the main
component being glycols) was successfully treated at concentrations less than
193 mg/1 (as carbon) with a total BOD load of 480 mg/1 (Jank, et al., 1974).
Organic loadings were kept to less than 0.15 kg BOD/kg MLSS/day to control
bulking, thus operating in the extended aeration range. Cox (1978) reviewed the
literature concerning polyethylene glycol (PEG) biodegradation and found
successful results for molecular weights less than 400. Biodegradation was
generally inversely proportional to molecular weight.
Four adipic acid esters were treated by acclimated activated sludge in a study by
Saeger (1976). In the range cf concentrations studieu (20-56 mg/1), the esters
vere substantially degraded with no inhibition of the activated sludge process.
Ui. nate biodegradation did occur. In a study of the activated sludge treatment
of a combination of methanol, acetylene, vinyl acetate, acetic acid and
formaldehyde, BOD removal was 99 percent at influent levels up to 1000 mg/1
(Schwartz, 1984). A two-stage (series) activated sludge unit provided more
process control and a low rate (extended aeration) activated sludge unit was not
as easily upset as conventional activated sludge.
Avendt and Avendt (1983) reported that an unspecified organometallic pesticide
dosed at levels up to 75 ug/1 in a municipal wastewater did not affect the
performance or stability of a full scale plant. Due to sluuge recycle, pesticide
concentrations up to 80 times the raw feed concentration were observed in the
activated sludge mixed liquor. Iannone, et al, (1984) found that pesticides
"passed through" New York City wastewater treatment plants utilizing activated
26

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sludge rather than being treated. Another study utilizing a pesticide mixture
observed significantly lower BOD removal at the 0.5 mg/1 pesticide level and
aome decrease in removal efficiency at 0.1 mg/1 (Smith, et al., 1981). At both
levels, however, the pesticides were significantly removed by the activated
sludge.
Kaneko, et al. (1976) reported no change in BOD removal efficiency at
polychlorinated biphenyl (PCB) concentrations up to 10vig/l, however there were
resulting changes in microflora, and increased aldolase and oxygen uptake
activity. PCBs were concentrated in the activated sludge by a factor of
103-104 without showing any appreciable decay. Kerbst (1977) found no organic
degradation of PCBs as well, but did find some volatilization occurring.
Furukawa (1978) and Liu (1980) studied the biodegradation of PCBs by micro-
organisms isolated from activated sludge cultures. Varying rates of biodegrada-
tion were reported, with the following two relationships being evident:
•	Degradation is inversely proportional to the level of chlorination.
•	PCBs containing two CI atoms in the ortho position (2, 2- or 2, 6-)
showed great resistance to degradation.
Baird (1977) and Barth and Bunch (1979) reported that benzidine inhibits aerobic
digestion in unacclimated cultures, but the laU.T article reported no inter-
ference to acclimated activated sludge in concentrations up to 30 mg/1.
Hydrazine had no effect on the activated sludge process and underwent complete
treatment at the 1 mg/1 level (Farmwald and MacNaughton, 1981). At levels
greater than 5 mg/1, COD removal seriously degraded and hydrazine in the
effluent was > 0.4 mg/1. Non-acclimated activated sludge handled slug doses of
hydrazine up to 44 mg/1 without serious impairment of COD removal.
Trisodium nitrilotriacetate (NTA) was 80-90 percent biodegradable in acclimated
activated sludge at levels up to 30 mg/1 (Renn, 1974). Treatment was poor using
unacclimated cultures. Nay, et al. (1974) reported successful biodegradation of
trinitrotoluene (TNT) with no substantial effects on acclimated extended
aeration activated sludge up to concentrations of 20 mg/1. At higher TNT levels,
biodegradation is inverse' ' proportional to the TNT concentration. Contact
stabilization with extended aeration is suggested for best biological treatment.
Chow and Ng (1983) studied the biodegradation of n-methyl-Z-pyrrolid one at
100 mg/1. The compound was 95 percent biodegradable but produced an inter-
mediate carbonyl metabolite with a significant COD. Vaicum and Eminovici
(1974) found that 50 mg/1 of trinitrophenol had no effect on acclimated activated
sludge processes while 200 mg/1 caused substantial reduction in COD removal
efficiency.
Activated sludge treatment efficiency was not affected by various organic dyes
at 10 mg/1 concentrations (Dohanyos, et al., 1978). The removability of dyes by
activated sludge is proportional to the number of hydroxyl groups, the number of
nitro groups, the number of azo groups, the length of the molecule, increasing
electrokinetic potential and is inversely proportional to the number of sulfo
groups. Gledhill (1975) found rapid activated sludge acclimation to 200 vg/1 of
3, 4. 4'-trichlorocarbanilide (TCC). TCC was also substantially degraded.
27

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Miscellaneous industries -- A wide variety of aqueous wastes are generated by
industrial concerns and these wastes can result in a range of operational
difficulties in an activ ted sludge system. Hegg, et al. (1980) conducted a survey
of operational and maintenance problems at 50 POTWs. Problems such as toxi<~
pH conditions due to an acid discharge, turbid supernatant due to crankcase oil,
and loss of sludge inventory due to a suspected metal plating waste were
reported. A survey of German activated sludge plants (Wagner, 1984) revealed
that wastes from paper, milk processing, vegetable processing, hide and glue,
fruit processing, and distillation industries may exhibit a tendency to cause
bulking sludge associated with filamentous organisms because of unbalanced
nutrient loadings (high organic carbon and nitrogen, low phosphorus).
Slaughterhouse, metal processing and textile wastes were felt to be less likely to
cause bulking problems. Appr Viriate responses for sludge bulking could be
pretreatment denitrification, phosphorus addition or precipitation, and/or lime
addition for maintenance of favorable nutrient levels and mixed liquor pH.
Interferences with activated sludge processes may also be the result of parti-
culate types of contaminants. Wilson, et al. (1980) reported poor process
performance result) from the introduction of filamentous organisms into the
system from a pharmaceutical manufacturer -- a condition that was corrected
by increasing the SRV and MLSS of the system.
Wastes from petrochemical industries can contain degradable, nonbiodegradable,
and toxic organic compounds. The effects of urea and dichloromethane, two
possible constituents of refinery wastewater, on activated sludge treatment were
investigated by Gerber, et al. (1979). Urea was removed, but high ammonia
nitrogen concentrations insulted. Dichloromethane was removed by stripping
and it had a detrimental effect on nitrification prior to acclimation of the
system. Matsui, et al. (1975) examined the degradability of organic substances
found in wastewater from petrochemical industries. Thirty-five substaaces were
evaluated, the following fifteen of which were found to be highly resistant to
biodegradation:
4-chloro-2-methyl aniline
p-toluene-m-sulfonic acid
2-chloi->-5-amino-p-toluene	sulfonic acid
dinitrotoluene
P-naphthol
3-oxvnaphthoic	acid
4,4-dimethyl-l,3-dioxane
polyethylene glycol
PVA
silicon surfactant
methyl cellulose
2-chloroethanol
higher alcohol surfactant
acetoacetic-o-anilide (3A-4)
acetoacetic-m-xylidide (3A-5)
For wastewaters from individual industries, activated sludge COD removals
(after 24 hours of aeration) ranged from 14 to Jl percent.
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Stover and Kincannon (1983) experimentally investigated the treatability of
12 organic compounds using a bench-scale, activated sludge system. The results
of their thorough investigation included the removal efficiencies and biokinetic
constants for the individual compounds and various combinations, and the
percent removals attributed to volatilization. Kincannon, et al. (1982) evaluated
the treatability of two semiconductor-industry wastewaters containing a wide
variety of organic compounds, concluding that the two types of wastewaters
examined were compatible with the activated sludge process.
Monnig, et al. (1981) conducted investigations on the suitability of various
pesticide manufacturing wastewaters for discharge to municipal activated sludge
treatment facilities. The wastewaters examined were characterized only by the
type of pesticide from which they were generated and the results were described
qualitatively. Carbaryl, maneb, mancozeb, and dazomet wastewaters at
dilutions ranging from 0.1 to 10 percent were degraded with no adverse effects
on COD removal. Glyphosate and atrazine wastewaters were nondegradable with
no adverse effects while dinoseb and oryzalin wastewaters disrupted treatment
(even at low dilutions) and mancozeb, dazomet, and carbaryl wastewaters
inhibited nitrification.
Food processing wastewaters are generally amenable to activated sludge treat-
ment as illustrated by the work of Heddle (1979). Interferences with POTW
operation can occur due to organic overloading. Gerardi (1981) reported on the
interference of a fatty acid derivative waste from a manufacturer of food
emulsifiers on the performance of a POTW. This particular waste resulted in an
excess of filamentous organisms and poor sludge settleability. The problem was
resolved by equalization of flow and pretreatment of the manufacturing
wastewater. Other remedial measures attempted had no effect. Tolaney (1976)
characterized citrus processing wastewaters, described pilot-scale testing, and
presented design criteria for the high purity oxygen activated sludge treatment
of such a wastewater. An operational problem encountered was the result of
excessive filamentous organism growth within the system. This was a result of a
high influent temperature which was remedied by including a cooling tower in
the process scheme.
Wilson (1981) reported several problems associated with the discharge of a
potato chip processing wastewater to a small POTW. Very poor primary
sedimentation performance was possibly due to oil and grease, caustic process
water, and/or nonsettleable starches. Pretreatment of the industrial wastewater
stream was the appropriate response. Poor sludge setteability in the secondary
clarifier was the result of low amounts of phosphorus with respect to other
nutrients and substrate. Identification of the causes of the poor performance of
this POTW was confounded by the occurrence of hydraulic surging.
Radik (1984) documented the experiences of more than five years of operation of
a dairy industry wastewater treatment plant. Spills from various processes
resulting from equipment malfunctions and operator errors, and their effects on
the wastewater treatment process, were documented in addition to other
experiences related to both the diary product and wastewater treatment
facilities.
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Textile manufacturing facilities produce wastewaters with significant contami-
nants. The discharge of textile fibers to the wastewater stream can result in
fouling and plugging of aerators and pumps and dense blanket formation on
claiifiers (Troxler and Hopkins, 1982). In general, however, such textile
wastewaters have a higher BOD and lower TSS than domestic wastewater
Contaminants such as kerosene, polyvinyl alcohol and textile dyes may be
present which have various degrees of removal by activated sludge (Porter and
Snider, 1976). Polyvinyl alcohol can be removed by activated sludge treatment
without inhibiting the process (Hahn, et al., 1977). Gaffney (1976) reported that
chloro-biphenyls, while removed by activated sludge treatment, caused an
unbalanced microbial population and poor overall process performance. Textile
dyeing wastewaters were tested by Horning (1978) using bench-scale biological
and physical-chemical processes. The author discovered that dye bath
components were not inhibitory to carbonaceous BOD removal, but could inhibit
nitrification. The optimum treatment turned out to be staged biological plus
physical-chemical processing, as not eveD acclimated bacterial seeds could
metabolize the color-producing dye molecules.
Shock loads of textile mill wastewater can also interfere with POTW process
performance. Blevins (1982) reported that following such fluctuations in loading,
variations in an activated sludge microbial population occurred, resulting in poor
sludge settleability.
Dagon (1973) characterized photoprocessing wastewaters and presented a discus-
sion of the possible effects of the various constituents on the activated sludge
process. Experiments were also conducted in which it was found that the
presence of a photoprocessing wastewater at dilutions of 20 percent or less with
municipal wastewater had no adverse effects on an activated sludge process.
Bard, et al. (1976) considered the effects of various forms of silver in photo-
processing effluents on activated sludge treatment. It was concluded that
insoluble silver or silver thiosulfate would exhibit no effects while silver nitrate
and silver chloride would inhibit the activated sludge process.
Reinbold and Malleville (197 5) investigated the activated sludge treatability of
proc-ess water from the steaming of timber. Such waters are characterized by a
wide range of soluble and insoluble organic compounds and bench-scale experi-
mentation revealed that they are treatable provided that sufficient nitrogen and
phosphorus are added. Lowry and Chwirka (1983) reported that the activated
sludge treatment of combined municipal and papermill wastewater was hampered
by nutrient deficiencies and paper mill wastewater dumping, typically
characterized by high flow, extreme pH and fluctuating temperature. Dissolved
oxygen fluctuations resulted from the papermill wastewater variability which in
turn resulted in excessive filamentous growths and the attendant sludge bulking.
A buildup of papermill clay in the mixed liquor suspended solids was also
observed.
Kashinaya and Yoshimoto (1980) characterized tannery wastewater with respect
to the specific tanning processes that were involved. Pure oxygen activated
sludge treatment of combined municipal and tanning wastewater was also
successfully demonstrated and design criteria were presented.
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Cummins (1981) experimentally evaluated the effect of sanitary landfill leachate
on the activated sludge process. His primary result was that at the higher
leachate loadings, poor settleability of the sludge solids occurred. It was
recommended that further studies be conducted with respect to possible system
acclimation and process control strategies.
Powdered activated carbon/activated sludge process—
The ability of an activated sludge process to handle organic contaminants can be
enhanced by the addition of powdered activated carbon (PAC). Bauer, et al.
(1981) compared the treatment of coke plant wastewater by the RBC and PAC
enhanced activated sludge (PAC/AS) processes. Both processes performed
comparably, but the PAC/AS process had a better capability for nitrification on
a continuous basis, independent of the COD loading. Weber, et al. (1983) found
that lindane could be removed by the PAC/AS process. Other studies have
similarly examined the applicability of the PAC/AS process for treating a
variety of wastewaters and contaminants (Soderberg and Bockrath, 1985;
Janaczek and Lamb, 1983; and Shaul, et. al., 1983).
Variables of importance related to PAC enhancement of activated sludge include
the carbon dosage and the degree of mixing--both of which can govern the
contaminant removal efficiency of the process (Weber, et al., 1983).
From bench-scale experimentation of the pretreatment of chemical production
wastewaters, Leipzig and Hockenburg (1980) found that the PAC/AS process had
the capacity to handle organic shock loads in addition to allowing nitrification to
occur despite the presence of inhibitory materials. Sundstrom, et al. (1979)
found that periodic addition of PAC to an activated sludge system was effective
in removing shock loads of phenol but glucose shock loads were moderated only
slightly.
Ferguson, et al. (1979) evaluated PAC used in conjunction with contact stabiliza-
tion activated sludge. Shock loadings of trichlorophenol were evidenced by a loss
of COD removal efficiency only when the PAC dosage was low. Excessive
carbon dosages were, however, also detrimental to the process.
Several studies of full-scale PAC/AS systems have been published. Dunn and
Hutton (1983) reported that organic and heavy metal removals of 50 to
60 percent could be obtained. Hutton and Temple (1979) found that a PAC/AS
process could outperform a conventional activated sludge system — particularly
in the removal of extractable organics. Pitkat and Berndt (1981) discussed the
treatment of textile waste at a municipal PAC/AS treatment plant and
presented operational data for both the overall treatment process and for the
wet air oxidation-carbon recovery process.
Lagoons —
Little research has been conducted on pollutant interference of municipal
wastewater lagoons, however some characteristics of an aerated lagoon or
oxidation pond are similar to extended aeration activated sludge. Facultative
lagoons cannot be as easily likened.
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Abeliovich and Azov (1976) found that ammonia and metbylaraine concentrations
over 2.0 mM at pH levels greater than 8 inhibit photosynthesis and therefore
oxygen levels in an oxidation pond. Increasing the detention time of the
oxidation pond lowered the ammonia concentration and restored proper operating
conditions. In another oxidation pond study, Miller, et al. (1977) studied the
impact of increased carbon supply on algae growth. Growth of algae {and
therefore oxygen production) was enhanced due to the additional nutrients of an
added sludge stream.
A three-cell, 0.40 mgd lagoon system in Eudora, Kansas was studied by McKinney
(1977). Most of the biodegradation was accomplished in the first cell, but
inadequate settling of the dead microbes in cells two and three resulted in an
effluent TSS which exceeded the 30 mg/1 permit limit.
The performance of an aerated lagoon treating a refinery waste was improved
after the addition of a selective bacteria (Nyer and Bourgeois, 1981). Belly,
et al. (1975) showed that the ferric chelate of EDTA was biologically degraded
by a mixed population of aerated lagoon microbes.
Meel, et al. (1976) investigated the treatment of combined potato processing and
municipal wastewater by anaerobic and aerobic lagoons. Various combinations
were studied and best results were obtained by staging the lagoons in an
anaerobic/aerobic series. Low pH and temperatures had little effect on the
process. In another study, Klein (1974) found 90 percent steady state removal of
trisodium nitrilotriacetate (NTA) in an aerobic stabilization pond.
Anaerobic Reactors —
Engineers have historically been reluctant to design anaerobic treatment systems
for industrial wastewaters containing toxicants. The belief that methanogens
are inherently more sensitive to contaminants than aerobic or facultative
organisms is disputed by Parkin, et al. (1983). The authors tested four pollutants
(nickel, sulfide, formaldehyde and ammonium) in batch, semi-batch and contin-
uous flow reactors, and discovered that acclimated cultures could tolerate
toxicant concentrations 2.4 to IE times higher than unacclimated systems with
no upsets. Hie use of high SRTs promotes such acclimation, mitigating the
effects of decreased gas production resulting from process inhibition. The study
also noted that extended periods of zero gas production may not indicate total
process failure, but rather the system will often start up again after the toxicant
is purged from the system.
Additional evidence promoting the use of anaerobic treatment with acclimated
cultures is provided by other authors. Pearson, et al. (1980) note the inhibitory
effects of formaldehyde, zinc sulfate, phenol and ammonium in bench-scale
testing of recreational vehicle tank waste, but observed greater stability of
acclimated over non-acclimated systems at the 50 percent kill dosages. Sulfide
and sulfite inhibition of anaerobic treatment in both continuous flow and batch
modes was studied by Eis, et al. (1983). The impact of these contaminants on
methane production and COD removal efficiency was minimized when the
reactors were acclimated to sulfur.
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There is some discrepancy in the literature regarding the anaerobic degradation
of phenol. Healy and Young (1978) report complete degradation of phenol to
methane and carbon dioxide following an 18-day acclimation period plus an
additional 14-days of biodegradation. The authors even cite the first reported
case of anaerobic degradation of catechol, using a 32-day acclimation period.
Neufeld, et al. (1980b) indicate the need for a 40-day SRT for effective and
stable phenol decomposition to organic acids, but no methane production. At
phenol concentrations above 686 rag/1, they note distinct substrate inhibition to
non-methanogenic decomposition. Later work by Healy and Young (1979)
produced results similar to their phenol study for eleven simple aromatic
compounds. Anaerobic decomposition to methane was achieved with long
acclimation and treatment periods.
Fixed Film Processes
Trickling Filters —
An overview of trickling filter performance was provided by Haugh, et al. (1981)
in a survey of 11 plants in 6 states with flows ranging from 0.5 to 33.7 mgd.
They found that increased effluent BOD generally resulted from:
•	increased flow rates.
•	increased influent BOD.
•	pH out of 6.5 to 8.5 range.
•	the presence of toxics.
Most of the recent literature has studied the treatment or effects of specific
industrial wastes on trickling filter processes. Two references have shown that
using trickling filters as a first-stage preceding activated sludge can control
bulking sludge problems resulting from filamentous organisms. Anderson (1980)
reported on a pharmaceutical wastewater in Lincoln, Nebraska containing high
concentrations of sugars in a nitrogen deficient environment. The addition of an
equalization basin and a biotower mitigated the effects of shock loadings on the
activated sludge system, resulting in overall BOD and COD removals of 94 to
99 percent and 86 to 91 percent, respectively. The use of a pilot-scale plastic
media trickling filter preceding an oxidation ditch for the treatment of brewery
wastes was analyzed by Biesinger, et al. (1980). High organic loadings (400 to
1200 lb BOD/d/1000 ft-^) to the fi*ed film reactors serves as a population
selector for non-filamentous organisms, eliminating their presence in the
oxidation ditch.
High hydraulic and organic loadings coupled with high concentrations of fats, oils
and grease make slaughterhouse wastewaters troublesome. Li, et al. (1984)
found that employing air flotation for oil and grease removal ahead of biofiltra-
tion was an effective treatment system. Combined domestic and tannery
wastewater was treated by a combination of pilot-scale systems in Alexandria,
Egypt (Hamza, et al., 1982). High concentrations of metals, organics, sulfide
salts and ammonia result in a highly toxic wastewater. A combination of
physical/chemical, biofiltration and post-filtration processes were successfully
employed to remove conventional pollutants and reduce the toxicity of the
wastewater.
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Chloro-biphenyls are present in dye carriers used in the carpet industry which
severely inhibit secondary biological treatment processes. Trickling filters
subject to such compounds have produced thin slimes, a red color, black deposits,
large populations of filamentous bacteria with no attached ciliates or rotifiers in
northwest Georgia (Gaffney- 1976). These facilities showed poor treatment of
conventional pollutants, but were removing the biphenyls. Fox and Merrick
(1982) studied a PCB spill contamination at an Alcoa facility treating combined
domestic and industrial waste in Lafayette, Indiana. In this case, the authors
noted that 84 percent of the PCBs were removed in the clarifiers, with only an
additional 10 percent taken out by the trickling filters. Upsets were prevented
by optimizing the polymer feed to the clarifiers which minimized the effect on
the biological process.
Nitrification inhibition by fertilizer constituents was analyzed by Beg, et al.
(1981). A packed-bed, bench-scale reactor was fed synthetic wastewater
containing a fixed ammonia concentration with varying dosages of sodium
fluoride, sodium arsenate and potassium dichromate. Inhibition, defined as a
50 percent reduction in biological activity, occurred at 50, 292 and 1218 mg/1 for
Cr, As and F, respectively.
Rotating Biological Contactors —
The rotating biological contactor (RBC) process has only been commercially
available in this country since the early 1970's, yet more research has been
performed regarding industrial pollutant treatability and impact on this process
than all other fixed-film processes. Such high levels of activity are partly due to
the notoriety of RBCs and" partly resulting from the availability of suitable pilot-
scale equipment.
Coventional pollutants -- Pilot-scale studies (Fry, et al., 1982; Ouyang, 1984)
have analyzed the impact of hydraulic and organic shock loads on the treatment
of domestic or synthetic wastewater. At three times the normal flow rate, the
dissolved oxygen level in the basins decreased and nitrification was inhibited. At
still higher flows, BOD and COD removals may also become inhibited. No
adverse effects were noted with organic shock loadings until they reached three
to four times the design loads. Hammer (1983) reported on the organic shock
loadings from a cheese processing wastewater discharged to the Newman
Grove, Nebraska municipal treatment plant. One to two hour flows containing
35,000 mg/1 BOD would cause the effluent BOD to increase from 10 to 60 mg/1
for a two day period. Attempts to equalize organic loads throughout the RBC
trains by altering the staging arrangements proved unsuccessful in this case.
Organic overloads are a common problem at numerous municipal RBC facilities.
The Kirksville, Missouri plant witnessed excessive biomass growth (and
ultimately a shaft failure) and decreased BOD removal due to organic overloads
(Newbry, et al., 1982). Supplemental air at 70 cfm/shaft increased sloughing,
thereby reducing shaft weight, but with no noticeable improvement in BOD
removal. Similar results were obtained by Surampalli, et al. (1984) at
Ames, Iowa in their use of supplemental air to eliminate Beggiatoa and reduce
biomass thickness. RBC system staging and configuration has also been shown to
influence organic loading capacity (Zogorski, 1984). An eight shaft, eight-stage
(one shaft/stage) train arrangement could not withstand the same organic
loadings as an eight shaft, four-stage (4-2-1-1 configuration) system.
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RBC treatment of munitions manufacturing wastewater at the Radford, Virginia
Army Base is subject to shock organic loadings and severe pH fluctuations (Smith
and Greene, 1982). The organic shocks cause an initial decrease in BOD removal,
with a subsequent growth of biomass to accommodate the loading. Similar BOD
removal reductions occur with pH shock, but the system quickly recovers
following pH correction. Attempts to mitigate these effects with adjustments in
the equalization basin have met with modest success.
Metals -- A few studies have considered the effects of metals on RBCs. Copper
has no impact on the process up to 10 mg/1, (Chang, et al., 1985; Smith and
Moore, 1984) but reduces the organics removal efficiency by 10 to 15 percent in
the 25 to 50 mg/1 concentration range. Cadmium has been shown to limit
organics reduction by 10 percent over the entire range from 5 to 20 mg/1 (Chang,
et al., 1985). Hexavalent chromium levels of 1.4 mg/1 resulted in a slight
reduction of both BOD and 1, 1, 1 -trichloroethane removal over a wide range of
applied loadings for these parameters (Blumenschein and Helwick, 1983).
Pretreatment -- Numerous industrial wastewaters have been tested in RBC pilot
systems for treatability in pretreatment applications. Coal gasification
wastewater was treated in a single-stage RBC by Turner, et al. (1984), who
observed BOD and phenol removals of 94 percent and 100 percent, respectively,
30 to 35 percent removal of COD and TOC, with negligible treatment of
ammonia, cyanide or thiocyanate. The results indicate that these refractory
organics are not inhibitory to biological processes. Bracewell, et al. (1980) noted
40 to 80 percent reductions for COD, phenols and formaldehyde in an acclimated
RBC pilot system.
Two separate studies by Landon-Arnold and Chan (1982, 1984) have demonstrated
the treatability of aqueous film forming foam (AFFF), a combination of
fluorochemical surfactants, hydrocarbon surfactants, ethylene glycol and water.
The results indicate significant BOD reduction (97 percent) up to 2000 mg/1
AFFF concentrations, provided pH adjustments are made and nutrients are added
if not mixed with domestic sewage. At higher concentrations, foaming problems
may occur.
Landfill leachates have been successfully treated in a couple of pilot-scale RBC
applications. Coulter (1984 observed significant degrees of COD, BOD, NH3,
phenols, cyanide and iron removal, with limited toxicity reduction. Smith and
Moore (1984) obtained similar results using synthetic leachate ind pesticides.
Eighty-five to 95 percent pesticide removals were recorded for influent
concentrations of 100 mg/1 and less. COD and BOD removals i^nained high,
with pesticide concentrations as large as 2000 mg/1.
Pilot-scale tests were performed comparing the addition of air with j. 11 ^ oxygen
to an RBC system treating high strength starch waste (Li, et al., 1982). At
loading rates of 38 and 95 g COD/m^/d, the air system experienced foaming and
septic conditions, while no problems were encountered in the oxygen-fed system.
Watt and Cahill (1980) exceeded 80 percent BOD and COD removals when
treating synthetic wastewaters containing phthalate esters and other oxochemi-
cals with bench-scale RBCs. When COD loadings were kept beiow 40 g/m^/d,
35

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removals consistently topped 90 percent. The treatment of relatively high
strength (1600 mg/1 BOD) synthetic wastewater was not affected by the presence
of explosives (RDX, IIMX, TNT), as BOD removals were at least 95 percent
(Chesler, 1980).
Slaughterhouse industrial wastewater discharging to a 16-shaft POTW was
studied by Stover and Rakness (1984). The soluble BOD loading of
5 lb/d/1000 ft^ resulted in a dark black, thick biomass covered with a white,
stringy growth. Staged treatment at the municipal site was deemed the best
alternative for achieving NPDES permit compliance.
Aerated Submerged Filters —
Comparatively little research has been reported in the literature on aerated
submerged filters (ASF), particularly regarding treatment and effects of
industrial contaminants. Most of the information appears in manufacturer's
literature or in-house reports. Like any emerging technology, objective analysis
will follow as such systems become popular and are installed in treatment
facilities. References that do exist in the literature have focused on treatability
of specific contaminants or comparisons with existing technologies, with nothing
written on process upset or mitigation.
Kao and Kang (1984) treated soda pulp wastewater with a bench-scale submerged
biofilter, and found it to be more efficient than the reported performance of
activated sludge plants over the range of BOD loadings tested. Rusten and
Thorvaldsen (1983) compared the performance of a pilot-scale ASF with an
activated sludge unit for the treatment of a combination of food processing
wastes. The authors noted that the desired effluent COD concentration could be
achieved by the ASF at an organic loading rate four times greater than the
activated sludge system.
A fluidized bed reactor was employed that successfully removed cadmium,
copper and zinc from a synthetic industrial wastewater (Remacle and Houba,
1983). The metals were present in soluble form, and were subject to a two-day
detention period at 150 percent bed expansion with a dissolved oxygen
concentration of 4 mg/1.
Biodegradation of phenol (50 to 200 mg/1) in synthetic wastewater was
accomplished by Richards, et al. (1983) in a bench-scale, fluidized-bed apparatus.
Inert coal was used as the attached medium with oxygen bubbled into the
reaction flasks. The kinetics of phenol degradation were described on the basis
of a competitive inhibition model. Phenol treatability was also studied (Olthof
and Oleszkiewicz, 1983) in a pilot-scale packed bed reactor fed coke plant
wastes. Over a range of hydraulic loadings, there seemed to be a random pattern
of phenol degradation with organic loading.
Anaerobic Filters —
Anaerobic processes have become popular among a number of researchers
because of their process stability and the methane produced as a by-product of
the reactions. Kennedy and Berg (1982) demonstrated that their bench-scale
anaerobic filters maintained satisfactory removal efficiencies over a wide range
of loadings and temperatures when treating three different wastewater streams.
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Smith (1980) noted that an anaerobic RBC was not very sensitive to overload
conditions when properly acclimated to the wastewater.
Acclimation was further stressed by Wu, et al. (198Z) in a comprehensive
literature review of submerged anaerobic reactors. General conclusions of their
work were that:
•	Influent metals resulted in decreased gas production and increased
effluent COD.
•	Acclimation to high concentrations (specified) of sulfide, sodium,
formaldehyde, acrylic acid and acrolein was possible.
•	Cyanide, ammonia and nickel toxicity was reversible, but was non-
reversible for chloroform, formaldehyde and sulfide.
Rivera (1983) used acclimated cultures in an upflow reactor to treat zinc levels
ranging from 100 to 1000 mg/1, resulting in decreased COD removal and gas
production.
Slonim, et al. (1984) studied anaerobic/aerobic treatment of 4,
6-dinitro-o-cresol (DNOC). Their results indicate that DNOC is toxic to
anaerobic processing, unless a readily degradable carbon source (sucrose) is also
present in the waste stream, in which case DNOC is converted into simpler,
biodegradable compounds. Although anaerobic treatment did not remove BOD,
the conversion of DNOC in the anaerobic step made the waste amenable to COD
reduction in the aerobic process.
Two studies analyzed the impact of phenolics on bench-scale anaerobic activated
carbon filters used for industrial treatment (Khan, et al., 1981; Suidan, et al.,
1981). Long detention times (140 days) were required for acclimation, but once
acclimated, the cultures were resistant to shock loading effects. Stover, et al.
(1984) found that high loadings of fuel alcohol wastes resulted in increased
volatile acid levels and subsequent reduction in methane production and treat-
ment efficiency.
A fluidized, anaerobic, activated carbon filter was used by Skrinde and Bhagat
(1982) for denitrification of a mixed food-processing wastewater. The authors
noted that when the system was pre-acclimated with methanol, no inhibition
would occur when the feed switched to the industrial wastes. Lower hydraulic
detention times were required for this process than for other denitrification
systems, although as denitrification increased, so did the effluent BOD.
ADVANCED TREATMENT
Advanced treatment includes the physical, chemical, and biological wastewater
treatment processes that are used foi the removal of nutrients or as a polishing
step following secondary treatment. In this section of the review of the
literature, the effects of various pollutants and process conditions on biological
nutrient removal and physical/chemical processes used in wastewater treatment
are considered.
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Biological Nutrient Removal
The removal of nitrogen and phosphorus can be achieved biologically through the
processes of nitrification/denitrific ition and phosphorus uptake. Biological
nutrient removal is subject to interferences due to contaminants, or other
conditions, which inhibit the metabolic processes of the bacteria. Several recent
articles examine the effects of various wastewater contaminants on the nitrifi-
cation of ammonia to nitrate. An additional article compared the ability of
several processes to achieve nitrification in the presence of a suspected
contaminant. A dearth of information exists on the subjects of interferences to
denitrification and biological pnosphorus uptake in the recent literature.
Nitrification —
Conditions which can influence nitrification are temperature, pH and organic
loading. Low pH was found to retard nitrification in a second-stage RBC in a
study conducted by Stratta, et al. (1982). The system under study was for the
nitrification of a high-rate, trickling filter effluent with nitrogen concentrations
of 19-21 mg/1. Low alkalinity reduced nitrification in the long-term for pH
values less than 8.5. Short-term conditions of pH values from 7.0 to 8.5 had
little impact. An interference such as this could be remedied by pH monitoring
and adjustment. Neufeld, et al. (1986) studied the influence of elevated
temperatures on nitrification biokinetics. The authors found an apparent
maximum rate at 30°C for stable nitrification. Rates of nitrification decreased
on either side of this optimum. Ito and Matsuo (1980) found that high organic
loadings reduced nitrification in an RBC system. This would be expected since
nitrification is a function of the relative amounts of carbonaceous and
nitrogenous substrates. Yu, et al. (1984) examined RBC performance at various
wastewater treatment plants and established loading criteria for which
nitrification could occur.
Metals -- The influence of cadium, chromium, and/or nickel on biological
treatment has been the subject of a number of investigations. Sujarittanonta and
Sherrard (1981) found that while carbonaceous substrate removal was not
significantly affected in their bench-scale, completely-mixed activated sludge
system, a nickel concentration of 5 mg/1 caused nearly complete inhibition of
nitrification. The nitrifying organisms were thus more sensitive to nickel
interference than were the heterotrophic bacteria. Similar activated sludge
system behavior in the presence of nickel and cadmium was evidenced by the
work of Bagby and Sherrard (1981). Weber and Sherrard (1980) found that at
cadmium concentrations of 5 and 10 mg/1, nitrification was reduced by
30 percent and 60 percent, respectively. Nitrification in an RBC secondary
treatment system was studied by Kang and Borchardt (1982). Steady levels of
chromium caused suppression of nitrification. Shock loads at 50 mg/1 of
chromium resulted in immediate reductions of both COD removal and
nitrification. Evidence was also presented supporting the concept that inhibition
is the result of the adsorption of chromium onto active organisms.
Huang and Skeikhdeslami (1983) investigated the inhibition of bench-scale
nitrification in the presence of metals. Chromium, nickel, and zinc were found
to be inhibitory to both the ammonia and nitrite oxidation steps, although
ammonia oxidation was the most sensitive. Chromium reduced the rate of
38

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ammonia oxidation by 40 percent at a concentration of 0.065 rag/1 Cr. Nickel
concentrations of 2 mg/1 or greater completely inhibited ammonia oxidation,
while at lower concentrations, zinc was found to be the most lethal metal with
respect to ammonia oxidation.
Braam and Klapwijk (1981) investigated copper inhibition of nitrification in a
bench-scale, fill-and-draw activated sludge process. They exam^ed the form of
copper (soluble versus insoluble) as governed by the prevailing chemical condi-
tions and they found that the rate of nitrification varied inversely with the ratio
of insoluble copper to mixed liquor suspended solids. The effects of pH on the
rate of nitrification were therefore due, at least in part, to the effect of pH on
the amount of insoluble copper present for a given total copper concentration. It
is also interesting to note that the addition of nitrilotriacetic acid, (NTA)
cancelled the inhibitory effect of copper when the NTA was added within
24 hours of the addition of the copper.
Beg, et al. (1982) investigated the use of a fixed-film process for the nitrifica-
tion of a fertilizer manufacturing wastewater containing chromium, arsenic, and
fluoride. All three constituents were toxic with chromium having the most
significant effect and fluoride the least. Beg and Atiquallah (1983) found that
for a given concentration of fluoride or arsenic, the degree of inhibition due to
the weak inhibitor increased with increasing chromium concentration up to some
maximum degree of inhibition. As a result of their work, chromium, arsenic and
fluoride were all classified as reversible, non-competitive inhibitors.
Miscellaneous industries •-- Stafford (1974), Greenfield and Neufeld (1982),
Neufeld, et al. (1980a), and Yurovskaya (1982) investigated the effects of coking
plant wastewater constituents on nitrification. All three investigations involved
bench-scale testing in which nitrification was achieved using populations of
nitrifying organisms to which no organic carbon sources were fed (other than the
compound under study). Their results indicated that phenols and other
heterocyclic compounds interfered with the nitrification process by inhibition of
the Nitrosomonas bacteria. Thus, the oxidation of ammonia to nitrite was
inhibited, whereas the biological oxidation of nitrite to nitrate was unaffected.
Stafford (1974) found that inhibition occurred for phenol tconcentrations
exceeding 3 mg/1, and further suggested that upon acclimation of the nitrifying
organisms, the sensitivity to shock loadings could be minimized. Neufeld, et al.
(1980) examined the mechanism of phenol inhibition and presented a "modified
non-competitive" kinetic model.
Stafford (1974) also examined the effects of five pyridine compounds and found
that either nitrification step (ammonia to nitrite or nitrite to nitrate) could be
inhibited depending upon the specific compound. Thiocyanate, another consti-
tuent of coking plant wastewater, also inhibits nitrification, but only at much
higher concentrations ihan those observed for phenol inhibition (Greenfield and
Neufeld, 1982). Likewise, unionized ammonia in coking plant wastewater also
has been found to be an inhibitor (Neufeld, et al., 1980).
Other work by Neufeld, et al. (1986) found the toxic inhibition to biological
nitrification decreased in the order of free cyanide, coal tar acid phenolics
(derived from a coke plant), phenol, 2,3,6-trimethylphenol, 2-ethylpyridine,
39

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2,4.,6-trimethyphenol, complexed cyaniJ.es and thiocyanate. All substances
except free cyanide appear to follow a "shoulder effect" where low levels of
inhibitor had no influence on rates of biological nitrification while higher levels
had profound effects. The concentrations up to which there is no effect on the
maximum rate of nitrification are 1.2 mg/1 for the tar acid phenolics, 1.4 mg/1
for reagent phenol, 4.9 mg/1 for 2,3,6-trimethylphenol, 10.0 mg/1 for 2 ethylpyri-
dine, 30.0 mg/1 for 2,4,6-trimethylphenol, 69.0 mg/1 for complexed cyanide and
236 mg/1 for thiocyanate. Based upon the experimental observations, it appears
that free cyanide levels greater than 0.20 mg/1 must be avoided for stable
operation of biological nitrification. Inhibitory effects of moderately toxic
substances such as complexed cyanides, thiocyanates and methylated phenolics
can be compensated for by increasing the sludge age.
Ganczarczyk (1979) evaluated a two-stage activated sludge system with second-
stage nitrification for the treatment of coking plant wastewater. Dephenoliza-
tion was achieved in the first-stage, and despite significant fluctuations of
ammonia, thiocyanate, and phenol concentrations, second-stage nitrification was
achieved. Both stages were operated with long hydraulic residence times and
relatively high mixed liquor suspended solids concentrations.
An additional organic nitrification inhibitor that has been investigated is aniline
— a compound that is known to severely interfere with nitrification. Joel and
Grady (1977) found that nitrification occurred in a completely - mixed activated
sludge system of 7-day solids residence time that was fully acclimated to
aniline. When plug flow reactor conditions were simulated, however, nitrifica-
tion did not occur for the same SRT, although the aniline substrate underwent
degradation to less-than-toxic levels.
Panzer (1982) compared a conventional extended aeration nitrification system
with a combined nitrification/denitrification (N/D) extended aeration process for
the secondary treatment of cattlehide tannery wastewaters. Both systems
produced good COD and TKN removals (> 90%), but the N/D process was able to
handle a 40 percent greater COD loading rate while producing 28 percent less
sludge.
Hill and Gelman (1978) evaluated the effect of saline wastewater, as may be
generated by certain food and cheese processing operations, on nitrification.
They used a bench-scale activated sludge process with second-stage nitrification.
Chloride concentrations of 10,000 and 20,000 mg/1 as Cl~ reduced the rate of
nitrification by 70 percent or more at temperatures of 15°, 25°, and 35°C. The
three previous citations indicated that the maintenance of high mixed liquor
suspended solids concentrations cam lessen the impact of those contaminants.
Process comparisons -- Sampayo and Hollopeter (1979) reported on the bench-
and pilot-scale testing that was conducted for process selection for the treat-
ment of a combined domestic and industrial waste. Several alternatives
(conventional activated sludge, sludge reaeration, and rotating biological contac-
tors) were eliminated from consideration because of insufficient and/or inconsis-
tent nitrification. The absence of nitrification with these alternatives was felt
to be due to the presence of some unidentified, volatile organic contaminant. A
two-stage, high-purity-oxygen activated sludge system with second-stage nitrifi-
40

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cation similarily failed to provide ammonia oxidation. An intermediate strip-
ping-stage was added prior to the second-stage so that air-stripping of the
suspected volatile contaminant could be achieved. Some nitrification was
achieved when dissolved oxygen levels of 6 mg/1 or greater were maintained
within the stripping stage. Additional improvement in process performance was
achieved when the second-stage, high-purity-oxygen process was replaced by an
open reactor operated at a minimum dissolved oxygen level of 5 mg/1. Although
consistent and acceptable nitrification was not realized, carbonaceous BOD
removals occurred. The final process evaluated was a single-stage, powdered-
carbon, activated sludge process followed by filtration. With this process,
consistent ammonia reductions of 70 percent and greater were achieved. The
results of the field testing did indicate the presence of some volatile nitrifica-
tion inhibitor. An on-site gas analysis revealed 6 chlorinated hydrocarbons, of
which 1, Z-dichloroethane was the major contaminant, at a concentration of two
milligrams per cubic meter.
Phosphorus Removal —
As previously stated, the recent literature contains little information on
interference in biological phosphorus removal. Yall and Sinclair (1971) found
that 10"^M concentrations of 2,4-dinitrophenol resulted in anywhere from
20 percent to 80 percent inhibition of phosphorus uptake by activated sludge. At
10"^M, the inhibition was 100 percent. A literature review was conducted by
Elliot, et al. (1978) in which proposed mechanisms of biological phosphorus
removal in the activated sludge process were examined. The conclusions were in
the form of recommendations for maximizing phosphorus removal and as such,
they may be useful in handling an interference to wastewater treatment that
results from high phosphorus loadings. The recommendations were the following:
•	Prevent anaerobic conditions in the secondary clarifier.
•	Separately treat nutrient rich return flows, supernatants, and
filtrates.
•	Maintain a minimum mixed liquor pH of 6.
Physical/Chemical Processes
The physical/chemical treatment processes of adsorption, flotation, precipita-
tion, ion exchange, filtration, and oxidation can be used alone or in various
combinations as tertiary treatment following secondary biological treatment, or
as processes for the selective removal of organics or metals. The emphasis of
the recent literature has been on the treatability and removal of wastewater
contaminants by various physical/chemical processes. In this section, the
removals of organic and inorganic pollutants by physical/chemical processes will
be presented followed by an examination of the performance of several advanced
wastewater treatment processes for the simultaneous removal of organic and
inorganic pollutants.
Organic Pollutants —
The use of activated carbon for the removal of organic pollutants has been
widely investigated. El-Dib and Badaway (1979), Wood, et al. (1983), and
McManus, et al. (1985) demonstrated the effectiveness of granular activated
carbon for the removal of a wide variety of organic pollutants. The operational
41

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variables of surface loading rate and pH can have significant effects on
adsorption efficiency (Wood, .;t al., 1983). Additionally, the presence of multiple
pollutants can reduce the efficiency of the process, the desorption of pollutants
from the carbon can be significant, and activated carbon adsorption appears
selective for organics over metals (McManus, et al., 1985).
Ion exchange can be used as an alternative to activated carbon for the removal
of organics. Fox (1979) surveyed the available literature and concluded that ion
exchange resins could perform better than activated carbon. Concentration
reductions of chlorinated pesticides, pher ols, and other compounds of three
orders-of-magnitude and greater were reported.
Beds of ion exchange resins are subject to fouling due to a number of causes
which result in decreased capacity, reduced effluent quality, and operational
difficulties (Pelosi and McCarthy, 1982a, 1982b). Cationic resins are subject to
fouling by numerous cations. For example, iron, manganese and copper fouling
can result in channelling, decreased capacity and disruption of cross-linkages
within the resin -- problems that can be corrected through washing and chemical
treatment. Both cationic and anionic resins are subject to fouling because of the
accumulation of oil and grease, silt and clay, and microorganisms.
Organics removals can also be achieved using membrane filtration processes.
Phenolic compound removals by bench-scale membrane processes were demon-
strated by Klemetson and Scharbow (1979) and by Bhattacharyya, et ai. (1983).
Important variables that must be considered include the membrane characteri-
stics and pH. Hrubec, et al. (1983) found that reverse osmosis followed by
activated carbon adsorption was effective in the removal of micropollutants
from treated municipal wastevster. F.vmovaJs of trihalomethanes (THM's) and
chlorinated solvents were not, however, o:Hained.
The chemical oxidation of organic pollubirKS can be a feasible way of removing
those pollutants from the process >ftfa-ti., Rice (1981) described the known
aqueous reactions of ozone with both r.Tganic and inorganic hazardous chemicals.
Ozone oxidation is dependent upon condhiors of pH and the specific compounds
undergoing oxidation. For example, unsaturated aliphatic compounds generally
are readily reactive with ozone, while saturated aliphatic hydrocarbons are
unreactive toward ozone. The formation of intermediate oxidation products
must also be considered -¦• Mine of whicn may be hazardous. Ozonation of a
wastewater can also influence the biodegradation of organic constituents.
Medley and Stover (1983) examined the effects of ozone on the biodegradability
of three organic compounds with varying vesalts. Acrylonitrile was not oxidized
by ozonation and adverse effects on biodegradation were apparent. l,2--dichloro-
propane was readily oxidized with small o^one doses and although not oxidized,
the biodegradability of ('-,4-dinitrophenol was increased.
Oxidation of organics by ozone may be promoted in the presence of ultraviolet
(UV) radiation (Nail, 1980). Termed photc-ozonation, this process u-as found to
result in higher reaction rates than for Ihe oxidation of phenol? with ozone
(Otake, et al., 1979). Organic compound oxidation can be conducted in other
ways as well. DeLuca, et al. (1983) experimentally investigated the oxidation
and removal of toxic organics using a tv.'o-step process of oxidation with
42

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potassium ferrate followed by alum coagulation. One-hundred-percent removals
of trichloroethylene and napthalene were acheived while other results showed
little process effects. Other workers examined the oxidation of phenols with
hydrogen peroxide in the presence of an iron catalyst- (Butler and Nandam, 1981).
McCarty and Reinhard (1980) investigated the removal of 25 trace organics by a
full-scale, advanced wastewater treatment (AWT) plant (Water Factory 21,
Orange County, California). The treatment scheme consisted of lime clarifica-
tion, ammonia stripping, recarbonation, filtration, activated carbon adsorption,
and reverse osmosis. Treatment plant records spanning three years were
examined in detail and very high organics removal efficiencies had been
achieved. The data also revealed a significant improvement in organics removal
upon the near simultaneous change from trickling filters to activated sludge
preceding the AWT process and a reduction in the industrial component of the
wastewater. Although the separate effects of each change could not be
ascertained, they were both felt to be of possible significance.
Inorganic Pollutants —
As with organic pollutants, several physical and chemical processes can be used
for the removal of metals and other inorganic pollutants from wastewater.
Metals can be readily precipitated from water as described by Jenke, et al.
(1983). Upon the addition of lime (or other strong base), metals can precipitate
out of solution in the form of metal hydroxides which can then be removed by
conventional solid-liquid separation processes. Kim and Amodeo (1983), how-
ever, reported on am instance in which the presence of chelating agents or
synthetic fat in the waste interfered with hydroxide-precipitation treatment of
an industrial wastewater. The interference was reduced by the precipitation of
heavy metal sulfides following the addition of calcium sulfide.
Christensen and Delwiche (1982) reported a pilot-scale investigation on the
removal of metals by hydroxide precipitation, flocculation, and ultrafiltration.
In this instance, the presence of cyanide interfered with hydroxide precipitation
because of an increase in copper solubility resulting from the formation of
copper-cyanide complexes. It was felt that the interferences from cyanide
would be reduced at higher process temperatures due to reduced stability of
cyanide complexes, or upon chemical destruction of the cyanide by chlorination.
Other processes have been proposed for the removal of metals which involve
dissolved air flotation. Chavalitnitikul and Brunker (1981) conducted bench-scale
testing of foam flotation. With this process, soluble metals combine with added
surfactants and are removed with the float. Percent removals of 60 to 75 for
several metals including cadmium, chromium, and lead were achieved. A similar
process termed colloid foam flotation was investigated by Mclntyre, et al.
(1983). In this process, soluble metals adsorb onto the surface of inorganic
coagulant floes and can then be removed with the float. Good removals of
copper, chromium, and zinc were achieved and suggested design and operational
data were presented. Benjamin and Leckie (1981) investigated the mechanism of
heavy metal removal by adsorption onto amorphous iron oxyhydroxide which,
while serving as the basis for the flotation process investigated by Mclntyre,
et al. (1983), would also serve as a basis for metals removal by conventional
coagulation/sedimentation/filtration processes.
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The removal of metals from wastewater can also be accomplished with ion
exchange or membrane filtration processes. Huang and Wirth {1981) demon-
strated the removal of cadmium to concentrations less than 0.1 mg/1 using an
aluminosilicate ion exchange material. Although a nonmetal, cyanide is also
subject to removal by the ion exchange process (Chanda, et al., 1983). Bhatta-
charyya, et al. (1979) demonstrated the feasibility of heavy metals, sulfate, and
suspended solids removal from a scrubber blow-down water using ultrafiltration.
Beckwith, et al. (1983) investigated the removal of particulate mercury in three
activated sludge POTWs. They concluded that the addition of aluminum sulfate
or sodium aluminate had no measurable effect on the fate of mercury within the
process. Chen, et al. (1984) investigated the removal of organic and inorganic
forms of mercury by a sulfide precipitation/activated carbon/neutralization
process. Reductions from greater than 100 mg/1 to less than 1 mg/1 were
realized, and it was felt by the authors that the process was superior to
precipitation by either carbonate or sodium borohydride addition.
As noted by Rice (1981), metals of lower oxidation states are readily oxidized to
their highest state and inorganic anions (e.g. cyanide, sulfide, and thiocyanate),
can be destroyed by ozonation and converted to carbon dioxide, sulfate, and
nitrogen. Bench-and pilot-scale investigations conducted by Sukes, et al. (1984)
demonstrated cyanide destruction by ozone oxidation. As a result of their work,
they formulated a lengthy list of conclusions regarding the process and a set of
design criteria were established.
The destruction of cyanide by a copper-catalyzed, sulfur dioxide/air oxidation
process was demonstrated on a laboratory-scale by Nutt and Zaidi (1984). The
process was proposed for the treatment of cyanide-containing wastewaters from
gold mills and metal finishing plants.
Miscellaneous Processes —
Osantowski and Hendricks (1982) investigated the treatment of coke plant
wastewater using several advanced processes. The most efficient process
examined consisted of a two-stage activated sludge process followed by acti-
vated carbon adsorption and granular-media filtration. Excellent volatile
organics removals with incomplete metals removal were obtained. Zwikl, et al.
(1982) investigated the treatment of a similar wastewater using activated carbon
followed by alkaline chlorination. Effective removals of organic and inorganic
contaminants, except phenol, were achieved.
Vuceta, et al., (1979) examined the removals of inorganic and oily waste
contaminants by various physical and chemical processes including the chemical
destruction of cyanide and reduction of chromium, followed by precipitation,
Hocculation and sedimentation, and filtration. The bench-scale tests demon-
strated that the various pollutants could be effectively removed.
Rooney and Wu (1982) reported on the performance of a full-scale tertiary
treatment facility for the joint treatment of municipal and meat-packing
wastewaters. After pretreatment in anaerobic lagoons, the industrial waste-
water was combined with domestic waste to further biological treatment in an
aerated pond. The tertiary treatment step consisted of coagulation, floccula-
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tion, clarification, filtration, and chlorination. With the exception of ammonia,
final effluent standards were met. Although recommendations for further
ammonia reductions were presented (increase detention times of ponds and/or
breakpoint chlorination), supporting data were not made available.
SLUDGE PROCESSING
Interferences in sludge processing operations at POTW facilities can be of a
primary or secondary nature. Primary interferences are those in which a
contaminant directly inhibits or otherwise decreases the efficiency of a sludge
processing operation. Secondary interferences are those interferences in sludge
processing which are the result of a change in the characteristics of the sludge
which accompanies an interference of a preceding wastewater treatment
process.
For purposes of this literature review, sludge processing has been defined to
include biological and physical-chemical sludge treatment operations and the
ultimate disposal of the processed waste sludge solids.
Sludge Treatment
Digestion—
The focus of recent literature on the inhibition of biological digestion processes
has been on anaerobic digestion. This perhaps is the result of the known,
sensitive nature of the process. It would, however, be logical to conclude that
interferences to aerobic digestion can occur. Additionally, the interferences
may be similar to those experienced by the activated sludge process with the
exceptions that the typically long solids residence times and high biological
solids concentrations of aerobic digestion may serve to reduce the effects of
some contaminants.
Metals -- Interferences of the anaerobic digestion process can be caused by the
presence of metals and other inorganic contaminants. However, noted by Barth
and Bunch (1979), metal toxicity in full-scale POTWs may be primarily related to
shock loading situations, since the continuous sulfide precipitation of heavy
metals within a digeslor can preclude the adverse effects of the metals.
The toxicities of zinc, cadmium, copper, iron and chromium to bench-scale
anaerobic digestion have been investigated (Mosey and Hughes, 1975; Matsumoto
and Noike, 1978; Parkin and Miller, 1982). Suggested "safe" levels of metal ions
for anaerobic digestion of sludge have also been presented (Barth and Bunch,
1979). But, it is apparent that the effect of a given concentration of a metal
toxicant will be a function of the temperature and solids residence times of the
digestor (Parkin and Miller, 1982) and of the conditions within the digestor with
respect to pH and the sulfide and carbonate concentrations (Mosey and Hughes,
197 5). The latter chemical conditions control the solubilities of the various
metals and their possible precipitation and removal from the supernatant.
Henney, et al. (1980) documented the effect of an accidental spill of chromium
on the performance of a municipal wastewater treatment plant. Forty-one
kilograms of chromium (VI) gradually entered the anaerobic digestors with the
45

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maximum concentration reaching 17.4 mg/1. There was, however, no noticeable
effect on the digestion process.
Kobylinski and Bell (1983) reported that the light metals calcium and sodium
could inhibit volatile solids destruction at relatively high metal concentrations.
Ammonia inhibition of anaerobic digestion of poultry manure has also been
documented (Ripley, et al., 1984). In this case, very long acclimation periods
resulted in a biomass that was tolerant to high ammonia concentrations.
Organics -- Chou, et al. (1978) evaluated the effects of 52 petrochemical
compounds on a bench-scale, anaerobic fermentation process. The testing was
done using acclimated microbial populations and inhibition or toxicity was
indicated by reduced methane production. Relationships between the chemical
structure of the contaminants and their toxicities were examined. Aldehydes,
for example, were found to be toxic and the toxicity varied with the reciprocal
of the carbon chain length. Upon acclimation of t)"e system, the aldehyde
toxicity was reduced. The presence of amino, hydroxyl, and carboxyl functional
groups in various compounds were found to result in a decrease in the observed
toxicity.
Parkin and Miller (1982) evaluated the response of bench-scale methane fermen-
tation to the continuous addition of toxic compounds. The effects of process
temperature and solids residence time were also evaluated. For inhibition by
chloroform, formaldehyde, and hydrazine, the longer solids residence times (SRT)
of 25 to 50 days tended to lessen the severity of the inhibition through the
acclimation of the bacteria to the toxicant. A process temperature of 3 5°C also
appeared to optimize the acclimation process.
Parkin and Speece (1982) reported the results of a similar bench-scale investiga-
tion of the effects of shock loading of various toxicants, including formaldehyde,
on methane fermentation. Temporary reductions in methane production were
observed. It was found that by increasing the SRT of the system, the recovery
process was promoted. Also, models for predicting the rate of recovery were
presented.
The inhibition of anaerobic digestion by 24 organic pollutants was investigated by
Johnson and Young (1983). Of those compounds exhibiting toxicity at concentra-
tions of 100 mg/1 (50 percent or more reduction in gas production), ring-structure
compounds containing nitro-groups were distinguished by the reversal of inhibi-
tion following the biological reduction of the nitro-groups to amines. Hexachlo-
roethane was also degraded, at least in part, as evidenced by apparent dechlori-
nation of this compound. Other compounds were removed from solution not by
degradation, but by adsorption onto the biological solids. As demonstrated by
other investigators, inhibitory effects were again found to be lessened by
biological acclimation and longer SRTs. It was also hypothesized, but not
substantiated, that inhibitory effects should vary directly with the hydraulic
residence time of the system.
Choate, et al., (1982) reported on the less-than-expected capacity of an anaero-
bic digestor used to pretreat a high-strength, soluble starch waste prior to
discharge to a municipal treatment system. The diminished capacity of the
46

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digestor was, however, the result of a loss of solids with the supernatant. By
retaining the solids using ultrafiltration, an acceptable effluent was achieved.
The bulk of the literature has dealt with toxic effects, and not treatibility of a
contaminant during anaerobic digestion. An exception to this is the work of
Moore and Barth (1976) who found that a salt of nitrilotriacetic acid (NTA) was
biodegradable and did not inhibit digestion. This could be significant in view of
the use of NTA as a complexing agent for minimizing the effects of metals in
biological treatment (Braam and Klapwijk, 1981).
Dewatering and Thickening—
The review of the recent literature yielded no published work on the interference
of sludge dewatering and thickening operations by contaminants. Interferences
of a secondary nature can be inferred. For example, Gerhardi (1981) reported on
an interference of an activated sludge process that was caused by a food
manufacturing waste. The overall result was the production of biological solids
of poor settleability and such a change in the sludge characteristics could be a
secondary interference that would affect the handling, thickening, and
dewatering characteristics of the waste activated sludge.
Disposal
The primary interference to sludge disposal which results from pollutants
entering the POTW process stream is contamination of the sludge which may
preclude lower cost sludge disposal options. JRB Associates (1981b) reported
that of the POTWs with known sludge contamination, the sludge disposal method
was affected in two-thirds of those facilities.
The presence of metallic and organic contaminants in waste sludges has been
documented by Bailey and Zimomra (1981), Clevenger, et al. (1983), Fricke,
et al. (1985), and Strachan, et al. (1983). The occurance of heavy metal
contaminants has been primarily related to industrial sources (Coker and
Mathews, 1983; and Kock, et al.,1982).
Numerous studies have been conducted regarding the possible effects of land
disposal of contaminated sludges. (Naylor and Loehr, 1982a, 1982b; Beckett and
Davis, 1982; Coker and Matthews, 1983; Chang, et al., 1981; Weber, et al., 1983;
Baxter, et al., 1983; Jeffus, 1981; and Theis and Podgett, 1983). These studies
have considered such factors as crop uptake of pollutants, crop damage, and
leaching phenomena.
Mclntyre, et al. (1981a) found that the distribution of PCBs and organochlorine
insecticides between the solid and liquid phase in sludge was not altered by
common chemical conditioning and dewatering operations. Thus, the uptake of
pollutants by biological adsorption could result in a sludge disposal problem.
A possible remedial measure for the removal of metals from sludge is acid
treatment to lower the pH and subsequent leaching of the metal contaminants
(Woyniak and Huang, 1982; Jenkins, et al., 1981; and Button and Gaudy, 1982).
Cornwell and Westerhoff (1980) demonstrated that metals could be removed
from sludge using a liquid ion exchange solvent. The tests were, however, of a
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preliminary nature and additional work would be required before such a tech-
nique could be fully evaluated. Metals removal by chelation has also been
examined by Jenkins, et al. (1981), but they concluded t'.iat neither method of
metals removal and recovery would be economically attractive. However, such
methods may be necessary when no other disposal option exists.
Werthman, et al. (1982) presented a case study in which several alternatives for
the disposal of a contaminated sludge were evaluated. Included in the evaluation
were co-disposal with municipal refuse, separate landfilling, incineration, and a
re-evaluation of sludge dewatering operations in light of the increased disposal
costs resulting from the "hazardous" classification of the sludge.
SUMMARY
The literature concerning process upsets and interferences at municipal treat-
ment facilities is not equally distributed among the various process operations.
Clearly, the activated sludge processes have received the bulk of the attention
by researchers in bench, pilot and full-scale studies. Activated sludge treatment
rests on a firm theoretical foundation, is widely used in POTWs and is relatively
easy to model using pilot-scale reactors -- so it is not surprising that its'
database regarding interferences is more substantial than other processes. In
general, the quantity of literature available on interferences decreased from
suspended growth biological systems (including anaerobic degradation) to fixed
film processes to physical-chemical treatment. In fact, the use of physical-
chemical advanced treatment in POTWs is so infrequent that industrial waste-
water treatment literature must be consulted to properly review these processes.
The above literature review investigated the treatability and impact of conven-
tional and toxic pollutants on a process-by-process basis. However, several
design and operations concepts permeate the literature across arbitrary process
distinctions.
Acclimation
The most important concept in the resistance of biological treatment processes
to upsets caused by priority organics (and to a lesser extent metals) is the
acclimation of the microbial system to the contaminant. Suspended growth and
fixed film systems alike have demonstrated a two to twenty-fold increase in
tolerance of shock loads when switching from unaccliinated to acclimated
treatment. Some evidence suggests that acclimation to a particular compound
may provide a measure of resistance to similar compounds. Biological systems in
POTWs will acclimate to industrial organic wastes that are discharged at a
consistent level. It is therefore the occasional or highly variable industrial
discharges that create toxic inhibition problems, which must be handled by at-
the-source pretreatment or flow equalization.
Staged Treatment
Staged treatment can be defined as the use of separate biological systems linked
together in series for the removal of soluble organics and metals, and possibly
nitrification. A common example is the use of biotowers (roughing filters)
48

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preceding either activated sludge or RBC treatment- Such sytems have been
shown to be more resistant to contaminant upset and not as susceptible to
classical problems such as filamentous bacteria in an aeration basin or Begiattoa
in an RBC biofilm. The use of step-feed or step-aeration activated sludge
represents a compromise between single-stage and two-stage operation. Staged
treatment also helps protect the sensitive autotrophic organisms responsible for
nitrification, as contaminant shock loads are mediated by the first stage
treatment system.
Operations
The literature has consistently demonstrated a number of operational tools which
may prove valuable ;n mitigating the effects of contaminants. Most of these
tools are available to operators of activated sludge plants, as this is where the
research has been focused and such facilities generally provide the most
flexibility. Maintaining high mean cell residence times (for both secondary
treatment and digestion) and high mixed liquor suspended solids concentrations
helps to resist process upsets. Increasing the SRT and MLSS at the first
indication of a toxic dump will also help weather the storm. The addition of
powdered activated carbon to activated sludge aeration basins has been shown to
improve priority organic treatability and reduce the potential for process
inhibition. Adjustment of the wastewater pH to provide a more suitable
environment for microorganisms or to help control metal solubility is a very
important operational parameter.
Influent Wastewater Characteristics
The concentration and form of metal or organic contaminants can play a
significant role in downstream processing. The effects of metals on POTW
operation is largely dependent on whether they exist in a soluble or insoluble
form when they enter the plant. The metals-to-microorganism ratio has been
shown by some authors to be just as important to the fate of metals as F/M is to
organic degradation.
Obviously the higher the influent concentrations of pollutants, the more detri-
mental to treatment plant operations. However, the literature indicates no
consistent relationship between influent concentration of organics and effluent
concentration, treatability or toxicity. Some authors have indicated consistency
in particular classes of compounds, but not among organics with widely varying
properties. Pesticides and metals have demonstrated the least consistent results
of the contaminants considered by this review. The literature offers widely
varying conclusions concerning the treatability and impact of these compounds
by wastewater treatment systems.
In general, metals either enter POTWs at concentrations near their inhibition
levels, or concentrate in sludges to critical values. Priority organics, on the
other hand, enter at non-toxic concentrations and then are biodegraded by
acclimated aerobic or anaerobic systems. Hence, metals contamination is
generally more troublesome to POTWs than organics. Exceptions to this rule
would be the presence of non-biodegradable organics cr large diurnal fluctuations
of BOD or TSS not mediated by equalization. It is these exceptions which
49

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provide insight into why specific industries, such as textile producers or certain
food processors, are undersirable indirect dischargers who should install pre-
treatment and/or equalization facilities.
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SECTION 4
TELEPHONE SURVEY
A nationwide telephone survey was conducted to identify occurrences of POTW
interference and investigate the circumstances surrounding such events. While
the literature documented a few cases of POTW interferences, most cases
resulting from industrial waste discharges were identified through contacts with
regional and state water quality officials. This section describes the telephone
survey procedure and approach, follows with a summary of general survey
results, and closes with discussions concerning each state, grouped by geographi-
cal region.
PROCEDURE
Initial telephone contacts were made at the state level. Personnel in state water
quality agencies were interviewed, using the form in Appendix B as a general
outline. In many instances it was necessary to interview more than one state
official in order to obtain all the required information. Typically, discussions
were conducted with personnel in both "permits and compliance" and "pretreat-
ment". EPA has yet to delegate authority to some states for NPDES permit
writing, enforcement or pretreatment programs, and in such cases, state and
regional EPA officials were also contacted and interviewed following the same
outline used for state officials. The purpose of these interviews was two-fold:
•	to gain an understanding of pretreatment programs and interferences
on a general, state-wide basis; and
•	to identify specific POTWs experiencing interferences.
Over 90 state and regional wastewater officials were contacted in all.
Information explaining the circumstances surrounding an identified POTW inter-
ference was obtained from state personnel. In all instances, when sites were
identified as interference cases, the name of a plant operations or management
contact was obtained.
Follow-up telephone contact was made with POTWs identified by state personnel
as experiencing interferences. Interviews were conducted with POTW personnel,
which generally allowed for POTW characterization into one of three categories:
1. POTWs which are currently violating their NPDES Permit or are
experiencing sludge contamination as a result of industrial
discharges, and are working to correct the problems;
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2.	POTWs which had previously violated their NPDES Permit or had
experienced sludge contamination as a result of industrial discharges,
and have mitigated the problems to the point of consistent permit
compliance; and
3.	POTWs with past or present NPDES Permit violations or sludge
contamination, not principally due to industrial wastes.
For POTWs belonging in category 1 or 2 above, additional data or documents to
further describe the interference and the resulting mitigation efforts were
requested. Documentation typically consisted of engineering repoits, operating
data or correspondence files.
In addition to locating POTW interferences through state contacts, the 25 largest
cities in the United States were contacted independently to identify any
industrial related treatment plant operations problems. The premise of such
direct contact was that large metropolitan areas potentially treat wastewaters
with substantial industrial contributions, however, very few POTW interferences
were identified through this approach. Interviews were conducted using the form
presented in Appendix B, and when interference occurrences were identified,
additional information was obtained. Similarly, in October, 1985, the Associa-
tion of Metropolitan Sewerage Agencies (AMSA) published an article in the
AMSA Monthly Report, at the request of the EPA-Office of Water Enforcement
and Permits, asking member cities to contact EPA if they have experienced
POTW operational problems associated with industrial discharges. Although
there was limited response to the article, several AMSA members were indenti-
fied and contacted.
In all, over 160 municipalities or sanitation districts were identified and con-
tacted concerning POTW interference.
GENERAL SURVEY RESULTS
The findings of the telephone survey support several general conclusions about
POTW interference:
•	The major causes of interference can be ranked in decreasing order
as highly variable discharge of conventional pollutants (BOD, SS,
NH3), followed by metals and then toxic organics.
•	Food processing, textile, and chemical/pharmaceutical industries are
most commonly responsible for treatment plant upsets.
•	Treatment plants most adversely affected are small in size (<_5 mgd)
with one or two major industrial contributors.
•	The most successful interference mitigation efforts have occurred
when POTWs and industry have cooperatively worked to solve
problems.
•	Some POTW interference problems result from poor wastewater
characterization prior to facility design.
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Despite identification of numerous problems relating to toxic pollutants, the
majority of the POTW interferences were associated with highly variable
discharges of conventional pollutants. In some cases, flow equalization by
industry or by the municipality has alleviated or substantially reduced the
problems relating to BOD, SS, pH and NII3. Interferences associated with metals
or toxic organics usually result from "shock loadings" as well, giving the
biological treatment system insufficient time to acclimate.
The industries identified with POTW interferences were placed into or.e of six
categories. Since this project is not limited to interferences created by
"categorical industries", the industrial descriptions shown below are not neces-
sarily consistent with the EPA Standard Industrial Codes. The percentage of
plants surveyed which identified industries in these categories as interference
contributors are:
Metal plating/finishing and electronics
39%
Foovi and meat processing
38%
Chemicals, pharmaceuticals and dyes
27%
Textiles
12%
Wood and paper products
8%
Leather Tanning
7%
Metal plating/finishing and electronics industries generally cause interference
with sludge disposal due to biomass metals partitioning, although they can also
cause treatment upsets. The remaining industries primarily contribute large
loadings of conventional pollutants. The types of industries causing interfer-
ences were consistent with those identified through the literature survey.
The telephone survey revealed that wastewater treatment plants experiencing
interferences are generally less than 10 mgd in size (average dry weather design
flow), with those smaller than 5 mgd being most severely impacted. This fact
can be attributed to two factors. First, .'mall to medium size treatment plants
are more abundant tnan large ones. Secondly, dilution is an important factor in
larger plants, as domestic/industrial wastewater flow ratios tend to be higher.
Industrial waste streams which would impact small to medium sized plants are
treatable when diluted with large amounts of domestic wastewater in large
metropolitan plants, some in excess of 1 bgd. Most of the small to medium sized
plants experiencing interferences fall into two general categories: plants of less
than 5 mgd with a few key, identifiable industrial dischargers, and medium sized
plants (5-10 mgd) with several industrial dischargers.
State water quality representatives and local treatment plant personnel fre-
quently stressed that cooperation between industries and municipalities was an
important element in eliminating POTW interferences and implementing effec-
tive pretreatment programs. A simple formula or standard plan for achieving
this end does not exist, but the first step towards this goal must necessarily
come from the municipality or sanitation district. Industries may not realize
that practices they employ are detrimental to the municipal treatment plant's
operation. Through heightened awareness, municipalities can cause industries to
employ minor housecleaning or process modification steps to the benefit of both
the industry (reduced sewer charges or increased efficiency) and the POTW
(mitigated interference problems).
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Finally, some POTW problems are the result of poor wastewater characterization
by design engineers, resulting in treatment plants which experience interference
problems shortly after start-up. The problems may be the result of organic or
hydraulic overloads, improper plant equalization/pretreatment or a lack of
process variability and control. Plant personnel occasionally overstate design
deficiencies in an attempt to explain away problems created by operation and
maintenance inadequacies, but the problem appears to exist at a level deserving
attention.
REGIONAL RESULTS
For the purpose of this study, the couniry was divided into the five geographical
regions shown in Figure 1. Discussions for each region and state follow.
Northeast
Consistent with its reputation as an industrialized area, the greatest number of
POTW interferences were reported for the Northeast. In addition, this region is
the most diverse in terms of POTW interference as measured by plant size,
secondary treatment process and industrial contributors. All of the six major
categories of industrial users are represented as causing some POTW interfer-
ence, with chemical/pharmaceutical industries topping the list.
Connecticut, Delaware, Maine, Massachusetts, New Hampshire and Vermont —
POTW interference in these states is primarily confined to small facilities
(< 5mgd) with a single, significant industrial discharger. The industries include
metal plating, leather tanning, textiles, and food and fish processing. In some
cases pretreatment programs have yet to be implemented and enforced while in
other cases industries continue to violate pretreatment limits, occasionally
resulting in litigation. Extended aeration activated sludge and aerated lagoon
treatment systems are common biological processes at the POTWs identified.
New Jersey —
Chemical industries, including pharmaceutical and paint manufacturers, are the
principal cause of POTW interference in New Jersey, affecting both fixed film
and suspended growth treatment facilities. A secondary plant with a treatment
capacity of 300 mgd experiences interference due to paint manufacturing waste,
and was the largest site identified through all telephone contacts.
New York —
New York experiences POTW upsets and interferences primarily due to industries
discharging highly variable quantities of conventional pollutants. Dairy, paper
products and pharmaceutical manufacturing wastes are among the most difficult
to treat, due to the changing nature of the waste products. Industry water
conservation and process modifications have been successful in dealing with
some interference problems.
Pennsylvania —
All identified POTWs experiencing interferences in Pennsylvania are 6 mgd or
smaller in size. In most cases, a single significant industry discharges to the
municipal system, some causing chronic POTW effluent discharge limit violations
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Ul
t-n
NORTHWEST
SOUTHWEST
NORTHEAST
MIOWEST
SOUTHEAST
FIGURE 1
GEOGRAPHICAL REGIONS

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and others causing periodic treatment plant upsets. As is typical of the region, a
wide variety of pollutants and industrial sources are responsible for interfer-
ences.
Southeast
Like the Northeast region, the states of the Southeast region reported POTW
interference?-, being caused by a wide variety of industries. The textile, wood and
paper products, and leather tanning industries were mentioned as interference
causes nearly as often as the metal plating and food and meat processing
industries. No facility smaller than 1 mgd was identified as experiencing
interference.
Alabama and Mississippi —
Isolated POTW interferences are experienced in Alabama and Mississippi as a
result of food processing and timber products industries. Highly variabie
discharges of conventional pollutants make for difficult treatment situations;
chicken processing is the major "problem" industry. In Mississippi, most local
pretreatment programs are administered and enforced by the state, rather than
by municipalities. State officials report this arrangement to be working
satisfactorily.
Florida —
NPDES Permit violations as a result of industrial discharges are infrequent and
difficult to identify according to regional U.S. EPA officials. The U.S. EPA
retains control over NPDES Permits and pretreatment programs in Florida, while
the state enforces water quality standards. Since the great majority of
municipalities requiring pretreatment have existing programs, interferences are
not common. Problems are typically the result of toxic metal "dumps" or sludge
disposal limitations caused by metals accumulation.
Georgia, North Carolina, South Carolina —
The textile industry is a major economic force in these three states and at the
same time causes some POTW interferences. Textile mill operations often
involve batch processes that result in large, fluctuating wastewater flows at the
POTW if pretreatment/equalization is not employed. Flow equalization is
sometimes the only step necessary to keep POTWs from experiencing interfer-
ences. Metal plating and food processing industries were also reported as
causing interferences.
Kentucky and Tennessee —
Leather tanning, metal plating and steel industries create the majority of the
POTW interferences in Kentucky and Tennessee. The reported problems occur
when the industries are located in small towns with POTW treatment capacities
less than 10 mgd. In addition to BOD, SS and metal loadings, tanning operations
can cause colored water which presents a pass-through problem. Pretreatment
program implementation has significantly curtailed the occurrence of interfer-
ences. Better monitoring efforts at POTWs and in collection systems has
enabled wastewater officials to mitigate the effects of occasional toxic spills
and determine the source of contaminants.
56

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Maryland —
Typical of many states, Maryland possesses myriad industries, some causing
POTW interference. In contrast to other states however, two large plants
(greater than 60 mgd) in a major metropolitan area experience interferences
because of metal plating, chemical and paint manufacturing industries. Smaller
facilities report fats, oils and grease (FOG) and BOD associated problems.
Virginia and West Virginia —
Very few POTW interferences were reported for these two states, with high
conventional pollutant concentrations creating the biggest industrial wastewater
problem.
Midwest
The Midwest region is composed of many states with a mixture of agricultural
(food and meat processing) industries and more traditional heavy industries. As
such, interferences experienced at POTWs are diverse. POTW operation upsets
are not widely occurring due to industrial contaminants, but are still of
considerable concern to most state water quality agencies.
Illinois —
Industrial interference problems in Illinois were portrayed by state officials as
being difficult to identify. It was stated that non-compliance could be directly
attributed to industrial discharges in only a few cases. In these instances, both
conventional and metals were involved as the interfering pollutant, primarily
originating from food processing and electroplating industries, respectively. In
contrast to other states, most facilities identified as experiencing interferences
were medium to large in size (f 10 mgd).
Indiana —
Indiana is presently experiencing most of its industrial related POTW upsets in
plants with ] 2 mgd hydraulic capacity. Small facilities have difficulties meeting
effluent ammonia limits (particularly in trickling filter plants) and high conven-
tional pollutant loadings on the part of meat and food processors can periodically
inhibit plants to the point of non-compliance. Two cases of interference
problems in larger plants were identified as sludge contamination by metals,
eliminating land application as a disposal option.
Iowa and Nebraska —
Neither Iowa nor Nebraska are heavily industrialized states, with most existing
industry being confined to several of the larger cities. Isolated industrial
interferences exist, primarily due to meat and food processing or small electro-
plating facilities. In some small towns, meat and food processing industries
contribute as much as 50 percent of the total wastewater flow and strength.
Municipality/industry cooperation and pretreatment programs have corrected
and/or controlled most of the potentially serious situations.
Kansas —
Typical of many Midwestern and Southwestern states, greater than 70 percent of
municipal wastewater facilities in the state are lagoon/pond systems, often with
no direct discharge. Consequently, the permit compliance rate is high and state
57

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water quality officials indicate very few POTW interferences. Municipalities
with past interference problems have established pretreatment programs and
now maintain properly operating facilities.
Michigan —
State wastewater officials indicated that few POTW interferences are presently
occurring in the state. Metal and paper industries have caused operational
problems in the past, but long established pretreatment programs have virtually
eliminated POTW interferences. In at least one instance, a municipality has not
limited industrial pollutant concentrations through a pretreatment program, but
instead has opted to adjust it's facilities to accommodate all industrial waste-
water, with considerable success.
Missouri —
Missouri is typical of other Midwestern states, as it experiences a small number
of conventional and metal-caused POTW interferences. Most interferences
occur in small to medium sized towns with a single industrial contributor.
Industries identified by state personnel as causing operational problems include
poultry processing, cheese production and circuit board manufacturing. Many of
the interferences are related to non-equalized hydraulic and organic loading.
Ohio —
Ohio has the largest number of municipal wastewater treatment facilities of any
Midwestern state, yet reported fewer than six cases of plant process upsets due
to industrial wastewaters, most of these being isolated. Process upsets result
mainly from heavy, fluctuating conventional pollutant loadings. Occasional
heavy metals contamination of sludge was reported, but metals did not interfere
with POTW biological process operation. No POTW interference problems were
reported for the larger, heavily industrialized cities of Ohio.
Wisconsin —
Like Ohio, Wisconsin has a large number of POTWs, but state officials report
very few interference problems. Because of recent facility upgrades and new
facility construction, Wisconsin wastewater treatment plant flows and organic
loadings are generally under design capacities, possibly hindering identification
of wastewaters that might otherwise cause interferences. Past problems have
been connected with the state's dairy industry.
Southwest
POTW interferences in the Southwest region are primarily due to food and meat
processing industries and occasionally are due to metal plating and electronics
manufacturers. Metals and chemicals are not causing interferences hi expanding
high-technology areas, presumably because of sophisticated wastewater pre-
treatment and reuse facilities. Warm temperatures and ample space make non-
discharging treatment facilities popular for small communities, thus reducing the
likelihood of traditional interferences.
Arizona —
Arizona has fewer than 20 discharging NPDES wastewater treatment facilities in
the entire state. Only two POTW interference cases were reported, one
involving metal contamination in sludge, and another involving meat processing.
58

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Arkansas —
Discharge permit non-compliance resulting from interferences occur at approxi-
mately 2.5 percent of the regulated POTWs. Most major problems are associated
with the state's poultry industry, with processing plants often located in small
towns. The state has experienced some difficulty in working with POTWs and
industries to correct the problems.
California —
Despite its large population and supporting economic base, California does not
experience many interferences at wastewater treatment facilities. Most inter-
ferences appear to be isolated events, associated with "midnight dumps" of toxic
chemicals. Interferences caused by food processors may have been a problem in
the past but appear to be corrected. Well implemented and enforced pretreat-
ment programs prevent interferences in the larger metropolitan areas.
Colorado, Nevada, New Mexico, Oklahoma and Utah —
These five states have sparse populations and limited industrial bases.
Oklahoma, New Mexico and Utah state personnel essentially reported no
interference problems. Colorado and Nevada reported isolated interferences,
principally associated with periodic metal toxicity. Media publicity of toxic
upsets and improved pollutant detection equipment have helped limit the
occurrences and mitigate the negative impacts of toxic pollutant dumps.
Hawaii —
Interferences were not reported by Hawaii state personnel. Interference from
seasonal fruit processors may be a potential problem when primary facilities are
upgraded to full secondary treatment.
Louisiana —
Interferences are not significant at POTWs. Most notable industries are direct
dischargers, while others are encouraged to pretreat by stiff user surcharges.
Texas —
Texas reported a larger number of POTW interferences than any other state in
the region. Food and meat processing was the most often cited cause of plant
upsets. The discharge of these industries is typified by high BOD, SS and NH3
concentrations in addition to heavy grease loadings. Cooperative efforts on the
part of industry and treatment plant personnel have resulted in some remarkable
turnarounds in plant performance and effluent discharge compliance.
Northwest
The Northwest region is principally composed of non-industrialized states, caul
consequently experiences fewer POTW interference events than do other regions.
Alaska, Idaho and Montana —
These three states reported very few POTW interference problems. None of the
three states has a substantial industrial base and no food processors were
reported as causing interferences. Some municipalities are developing pretreat-
ment programs, not in response to present industrial dischargers, but in anticipa-
tion of future industrial development.
59

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Minnesota —
State water quality personnel report a small number of POTWs experiencing
interference problems, primarily due to highly variable discharges of conven-
tional pollutants originating in the food processing and dairy industries. The
state appears to keep close watch on non-complying facilities and is involved in
litigation as a.result of interfering industrial dischargers. Most problems are
associated with industries that are significant contributors to small (] 5 mgd)
treatment facilities.
North Dakota, South Dakota and Wyoming —
These three states experience very few POTW interference problems. A large
majority of the facilities are lagoon treatment systems, some of which are non-
discharging. Occasional problems are experienced in all three states with
variable discharges of conventional pollutants from food or meat processing
plants to small treatment facilities.
Oregon —
Oregon reported infrequent POTW interferences. State and regional personnel
noted only one recent incidence of interference, where a small municipal facility
(2 mgd) was periodically upset by toxic metals. An agreement between the city
and the metal plater has reduced the likelihood of such occurrences in the
future.
Washington —
The state experiences some problems with POTW interference, but has imple-
mented pretreatment programs to prevent these occurrences in most instances.
Interference potential exists in the central portion of the state where apple
processing is prevalent. Many of the chemicals used in apple processing can
cause toxic upsets and therefore cooperation between processors and treatment
plant personnel is required to prevent such events. Occasional upsets occur when
food processing waste volume or strength is suddenly increased at smaller
treatment facilities. Many communities discharging to Pacific Coast or Puget
Sound waters have primary treatment facilities which must be upgraded to
secondary treatment in the near future. The increased susceptibility of
biological treatment to upset could result in interference causation by some
presently non-interfering waste streams.
60

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SECTION 5
CASE STUDIES
A list of potential POTW interference case studies was developed as a result of
the telephone survey discussed in Section 4. Potential case studies identified
through the literature search (Section 3) were also followed up with phone calls,
adding a small number of sites to the list. A total of 117 potential case studies
were identified and they are presented in Figure 2 and in Tables 4 through 8 for
the Northeast, Southeast, Midwest, Southwest and Northwest regions
respectively. Forty-two (42) potential case studies were identified in the
Northeast, the largest number of any region, while the smallest number of
potential case studies, 5, were identified for the Northwest region. Thirty
(30) potential cases were identified in the Southeast region, 21 in the Midwest
region and 19 in the Southwest region. The design average flow, the secondary
treatment process, the type of pollutants involved and the responsible industries
are indicated in Tables 4 through 8 for each potential case study.
SELECTION PROCESS
The scope of this project prohibited making 117 case study site visits and so it
was necessary to reduce the number of case study sites to a manageable level.
The selection process involved several steps, the first of which was to evaluate
each potential POTW considering the following:
•	Has the interference problem been successfuly mitigated or has the
discharge permit compliance rate substantially improved?
•	Were treatment plant officials receptive to inquiries concerning this
project and interested in providing further assistance?
•	Has there been adequate documentation of the interference and its
correction?
Affirmative answers to the first two questions were necessary for the POTW to
be considered further as a case study site. Concerning the third question, the
interests of this study are best served by documenting successful interference
mitigation techniques not previously studied in this manner.
As a group, case study sites were chosen to reflect diversity in terms of:
•	geographical location
•	secondary treatment process
•	treatment plant size
•	industrial contributors
61

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6*»Q!
FIGURE 2
POTENTIAL CASE STUDIES

-------
TABLE 4
POTENTIAL CASE STUDIES - NORTHEAST

Design Flow
Secondary
Contaminants

Location
(mgd)
Treatment
Con. Met.
Org.
Industries
Connecticut





Branford
3
Oxygen AS
•
•
Textiles, Laundries
Vernon
6.5
PAC
•
•
Textiles, Metal Plating
Delaware





Bridgeville
0.8
Trickling Filters
•

Food Processing
Maine





Brewer
3
Complete Mix AS
•
•
Paper, Food Processing
Corinna
1 .Z
Ext. Aeration AS

•
Textiles
Lisbon
1.5
Ext. Aeration AS
• •
•
Metal Plating, Paper, Textiles
Massachusetts





Amesbury
1.9
Ext. Aeration AS
•

Metal Plating
Fall River
30
Oxygen AS
• •
•
Textiles, Chemicals, Metal Finishin
Gloucester
15
Prims-y Plant
•

Fish Processing
South Essex
41
Primary Plant
•

Tannery
New Hampshire





Ashland
l.t
Aerated Lagoons
•
•
Textiles
Derry
l.Z
Aerated Lagoons
•

Metal Plating
Merrimack
4.2
TF/AS
•

Brewery
Penacook
4.Z
Conventional AS
• •

Tannery
Pittsfield
0.4
Aerated Lagoons
• •

Tannery
Troy
0.3
Aerated Lagoons
•
•
Synthetic Materials

-------
TABLE 4 (Continued)
POTENTIAL CASE STUDIES - NORTHEAST

Design Flow
Secondary
Contaminants

Location
(mgd)
Treatment
Con. Met.
Org.
Industries
New Jersey





Bay Shore
8
Complete Mix AS

•
Fragrances
Hamilton Township
9.5
TF/RBC
•

Pharrnaceut icals
Passaic Valley
300
Oxygen AS
•

Paint
Perth Amboy
10
Primary Plant

•
Chemicals
New York





Beacon
6
Staged Aeration AS
•

Dairy (cheese)
Binghamton/Johnson City
18
Contact Stab. AS
•
•
Paper
Canandaigua
6.5
RBC
•

Winery
Gloversville/Johnstown
9.5
TF/AS
•

Tannery
Hornell
4
Complete Mix AS
•

Dairy
Niagara Falls
60
Physical/Chemical
•
•
Chemicals
Oswego (East)
3
Conventional AS
•

Paper
Rensselaer County
24
Step Aeration AS
•
•
Dyes, Pharmaceuticals
Syracuse Metro
86
Conventional AS
•
•
Pharmaceuticals
Pennsylvania





Danville
3.2
Contact Stab. AS
•

Metal Finishing
Hatfield Township
3.6
Complete Mix AS/AWT
•
•
Electronics, Chemicals
Lackawanna River Basin (Moosic)
1
Ext. Aeration AS

•
Paper
Lower Lackawanna Valley
6
Contact Stab. AS

•
Wood Preservatives
Maiden Creek
0.4
Aerated Fixed Film
•

Food Processing

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TABLE 4 (Continued)
POTENTIAL CASE STUDIES - NORTHEAST

Design Flow
Secondary
Contaminants

Location
(mgd)
Treatment
Con. Met.
Org.
Industries
Pennsylvania (continued)





Monaca
1.2
Conventional AS
•

Glass, Steel
Quakertown
4
Trickling Filters
•

Metal Plating
Telford
0.7
Ext. Aeration AS
•

Poultry
Williamsport
2.4
Conventional AS

•
Chemicals
Rhode Island





Warren
2
Conventional AS
•

Metal Plating
Warwick
5
Conventional AS
•

ElectTical Switches,





Metal Finishing
Vermont





Hinesburg »
0.3
Aerated Lagoons
•

Dairy (Cheese)
Williamstown
0.2
Aerated Lagoons
• •
»
Laundry

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TABLE 5
POTENTIAL CASE STUDIES - SOUTHEAST
Location
Design Flow
(mgd)
Secondary
Treatment
Contaminants
Con. Met. Org.
Industries
Florida





Tampa
60
Oxygen AS
• •
•
Brewery, Food Processing, Metal
Plating and Finishing
Georgia





Macon (2 Plants)
Sylvania
14, 14
0.5
TF, AS
AS
• •
•
•
•
Paper, Metal Plating
Textiles, Metal Plating
Kentucky





Ashland
Campbellsville
Elizabethtown
Middlesboro
Nicholasville
11
4.2
4.5
3.0
2.3
Oxidation Ditch
Oxidation Ditch
RBC
Conventional AS
RBC
• •
•
•
• •
•
•
•
•
•
Steel, Tannery
Textiles, Metal Plating
Ink and Dye, Metal Plating
Tannery
Metal Plating
Maryland





Baltimore (Back River)
180
TF/AS
• •
•
Metal Plating, Paint, Liquid
Waste Hauler
Baltimore (Patapsco)
Elkton
Frederick
70
3
7
Oxygen AS
RBC
Trickling Filters
Chemicals
Paint, Metal Finishing
Dairy, Metal Plating

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TABLE 5 (Continued)
POTENTIAL CASE STUDIES - SOUTHEAST
Design Flow	Secondary	Contaminants
Location	(mgd)	Treatment	Con. Met. Org.	Industries
Mississippi
Laurel (2 Plants)
Meridian
North Carolina
2,2
20
Conventional AS
Conventional AS
Food Processing
• Timber Products

Asheboro
Columbus
Raleigh
Rae ford
South Carolina
4	Trickling Filters
0.9	Ext. Aeration AS
23	AS
3	Ext. Aeration AS
Chemical, Textiles
Textiles
Metal Plating, Dairy
Poultry, Fragrances, Textiles
Chester (2 plants)
Gaffney (3 plants)
North Augusta
Tennessee
Chattanooga
Murfreesboro
Tullahoma
West Virginia
Martinsburg
2, 1	Ext. Aeration AS
1.5, 3.2, 3.6 AS
20	Ext. Aeration AS
65
10
5
Oxygen AS	•
Air/Oxygen AS	•
Batch Ext. Aeration AS •
Trickling Filters
Chemicals, Metal Plating
• Food Processing, Textiles
Textiles
c • Various
•	Dairy, Metal Plating
•	Tannery, Metal Plating
Fruit Processing

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TABLE 6
POTENTIAL CASE STUDIES - UIDWEST
Location
Design Flow
(mgd)
Secondary
Treat ment
Contaminants
Con. Met. Org.
Industries
Illinois
Dakota
Decatur
Gurnee (N.S.S.D.)
Rockford
Indiana
Indianapolis
Plymouth
East Chicago
Io*
Lake Mills
Marshalltown
Mi iscatine
Sioux City
0.05	Contact Stab. AS
27	AS/Ponds
20	Step Feed AS
60	Complete Mix AS
125	TF/Oxygen AS
1.5	Conventional AS
20	Conventional AS
0.4	TF/Pcnds
7.5	Conventional AS
13	Oxygen AS
30	Step Feed AS
Dairy (Cheese)
Food Processing
Metal Plating, Printing, Misc.
Metal Plating
Metal Plating, Pharmaceuticals
Food Processing
Steel, Chemicals, Meta! Plating
Electronics
Meat Packing, Metal Finishing
Food Processing
Metal Plating,
Pharmaceuticals
Michigan
Kalamazoo
Grand Rapids
54	PAC
66	Conventional AS
Paper, Pharmaceuticals
Metal Plating, Misc.

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TABLE 6 (Continued)
POTENTIAL CASE STUDIES - MIDWEST
Location
Design Flow
(mgd)
Secondary
Treatment
Contaminants
Con. Met. Org. Industries
Missouri




Joplin (3 plants)
St. Josephs
Springfield (2 plants)
15,12, 8.5
27
6.5, 30
Conventional AS
Conventional AS
Conventional AS
• •
•
•
Food Processing, Metal Plating
Food Processing
Electronics
Ohio




Newark
Cleveland (Westerly)
8
50
Conventional AS
Physical/Chemical
•
•	Dairy, Fiberglass
•	Motnl Plating, Chemicals

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TABLE 7
POTENTIAL CASE STUDIES - SOUTHWEST

Design Flow
Secondary
Contaminants

Location
(mgd)
Treatment
Con. Met.
Org.
Industries
Arizona





Phoenix (91st Ave)
120
Complete Mix AS
•

Electronics, Metal Plating
Tolleson
7.5
TF/Solids Contact
•

Meat Packing
California





Victor Valley
4.8
Modified Step Feed AS

•
Military Installation
Colorado





So. Fort Collins
1.5
AS
•

Metal Plating
Nevada





Minden-Gardnerville
1.5
Trickling Filters
•
•
Electronics
Reno-Sparks
24
AS (Phostrip)
• •

Metal Plating, Electronics,





Bottling Plants
Texas





Corsicana (2 plants)
3, 1
Conventional AS
•

Food Processing
Denisen (3 Plants)
2, 1.5, 1
Ext. Aer. AS, TF
•

Food Processing
Huntsville
I
Ext. Aeration AS
•
•
Metal Plating, Paint
Montgomery County
0.3
Contact Stab. AS

•
Photo Processing
Mt. Pleasant
1
Ext. Aeration As
•

Meat Packing
Nort'i Greens
0.3
Contact Stab, AS
•

Meat Packing
Paris
4.2
Ext. Aeration AS
•

Food Processing
Park Ten
1
Conventional AS
• •

Food Processing, Metal Plating
Sherman
8
TF/AS
•
•
Food Processing
Sulphur Springs
4
Conventional AS
•

Food Processing, Dairy

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TABLE 8
POTENTIAL CASE STUDIES - NORTHWEST

Design Flow
Secondary
Contaminants

Location
(mgd)
Treatment
Con. Met.
Org.
Industries
Oregon





Newberg
2
Conventional AS
•

Electronics
Washington





Seattle
190
Primary Plant
• •
•
Metal Finishing, Bottling
Lynden
1.7
ABF/Oxidation Ditch
•

Food Processing
Oroville
0.4
Ext. Aeration AS

•
Fruit Processing
Brewster
0.4
Ext. Aeration AS

•
Fruit Processing

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The final consideration for site selection involved budgetary constraints.
Twenty-five to thirty-five (25-3 5) case study site visits were considered feasible
provided the POTWs could be clustered into approximately ten trips. Final site
selection involved several iterations to satisfy the previously described criteria.
The 29 selected case study sites are listed in Table 9 and shown in Figure 3. As
can be seen, eight sites were chosen from the Northeast region, six from the
Southeast, six from the Midwest, seven from the Southwest and two from the.
Northwest. Table 10 shows the distribution of sites by secondary treatment
process, Table 11 shows the distribution of sites by treatment plant size, and
Table 12 shows the distribution of sites by major industrial contributor.
SITE VISIT LOGISTICS
The task of making the site visits was divided among five members of the
Wastewater Department of JMM's Pasadena Office. Case files were prepared
containing all telephone notes, letters, operating data or other information
concerning a selected case study. Sites were assigned to individuals such that
they could schedule two to four visits in any one trip.
Supervisory personnel at each POTW were contacted by the appropriate JMM
site visitor and a tentative visit date was arranged by telephone. After dates
were arranged for all sites to be visited in one trip, letters were sent to the same
supervisory personnel confirming the visit dates and detailing some of the
project objectives. The letters offered a suggested agenda and encouraged the
participation of POTW and municipal personnel from operations, laboratory and
pretreatment groups in the site visit discussions. The following is a typical
agenda for the one day visit:
Interview discussion was conducted in an informal fashion—the length and depth
of the interview varied depending on the size of the facility, the number of
personnel involved and the pre-visit organization of the contact person.
Typically, in audition to talking with the plant superinterdent/manager contact,
aji individual from operations and/or another from pretreatment were involved in
the discussions. Laboratory personnel occasionally participated in the discus-
sions as well.
An interview usually began by JMM personnel giving a brief overview of the
goals of the project, the work done to date, the purpose of the site visits and a
description of the site selection process. The discussions then typically
transitioned to the interference issues at the POTW. As a guide to insure that
the desired information was obtained on each visit, a standard site visit
interview form was developed prior to making any visits.' The form was intended
to remind interviewers about some specific information that was required from
each site, some of which might have been overlooked in the natural course of
10:00
11:00
12:00
1:00
2:00
Introduction and General Discussion
Operations
Lunch
Plant Tour
Laboratory and Records
72

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TABLE 9
SELECTED CASE STUDY SITES
REGION
STATE
LOCATION
NORTHEAST
SOUTHEAST
MIDWEST
New Jersey
New York
Pennsylvania
Georgia
Maryland
North Carolina
South Carolina
Illinois
Iowa
Ohio
Bayshore (Union Beach)
Hamilton Township (Trenton)
Passaic Valley (Newark)
Binghamton/Johnson City
Canandaigua
East Side (Oswego)
Hatfield Township (Colmar)
Maiden Creek (Blandon)
Rocky Creek (Macon)
Baltimore (Back River,
Patapsco)
Raeford
Neuse River (Raleigh)
Horse Creek (North Augusta)
Gurnee (NSSD)
Rockford
Lake Mills
Marshalltown
Sioux City
Newark
SOUTHWEST
NORTHWEST
Arizona
California
Texas
Oregon
Washington
91st Avenue (Phoenix)
Tolleson
Victor Valley (Victorville)
Denisen (Duck Creek,
Paw Paw)
Paris
Sherman
Newberg
Metro-West Point (Seattle)
73

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FIGURE 3
SELECTED CASE STUDIES

-------
TABLE 10
CASE STUDY SITES-SECONDARY TREATMENT PROCESS
Activated
Fixed
Fixed Film and

Sludge
Film
Suspended Growth
Primary
Baltimore, MD (Patapsco)
Canandaigua, NY
Baltimore, MD (Back River)
Metro, WA
Bayshore, NJ
Denison, TX (Paw Paw)
Lake Mills, IA

Binghamton, NY
Hamilton Township, NJ
Sherman, TX

Denison, TX (Duck Creek)
Maiden Creek, PA
Tolleson, AZ

East Side, NY



Gurnee, IL



Hatfield Township, PA



Horse Creek, SC
Marshalltown, IA
Newark, OH
Newberg, OR
Neuse River, NC
91st Avenue, AZ
Paris, TX
Passaic Valley, NJ
Raeford, NC
Rockford, IL
Rocky Creek, GA
Sioux City, IA
Victor Valley, CA

-------
TABLE 11
CASE STUDY SITES-TREATMENT PLANT SIZE
< 1.0 mgd
1-5 mgd
5-10 mgd
> 10 mgd
Lake Mills, IA
Maiden Creek, PA
Denison, TX (2 plants)
East Side, NY
Hatfield Township, PA
Newberg, OR
Paris, TX
Raeford, NC
Victor Valley, CA
Bayshore, NJ
Canandaipua, NY
Hamilton Township, NJ
Marshalltown, IA
Newark, OH
Sherman, TX
Tolleson, AZ
Baltimore, MD (2 plants)
Binghamton, NY
Gurnee, IL
Horse Creek^ SC
Neuse River, NC
91st Avenue, AZ
Passaic Valley, NJ
Rockford, IL
Rocky Creek, GA
Seattle, \VA
Sioux City, IA

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TABLE 12
CASE STUDY SITES-INDUS TRIAL CONTRIBUTORS
Food, Meat
and Dairy
Metal
and
Electronics
Chemical
and
Pharmaceutical
Textile
Pulp
and
Paper
Canandaigua, NY
Denison, TX (Both)
Maiden Creek, PA
Marshalltown, IA
Metro, WA
Newark, OH
Neuse River, NC
Paris, TX
Raeford, NC
Sherman, TX
Tolleson, AZ
Baltimore, MD (B.R.)
Gurnee, IL
Hatfield Township,
Lake Mills, IA
Marshalltown, IA
Metro, WA
Neuse River, NC
Newberg, OR
91st Avenue, AZ
Rockford, IL
Sioux City, IA
Baltimore, MD (Both)
Bayshore, NJ
Hamilton Township, NJ
Hatfield Township, PA
Newark, OH
Passaic Valley, NJ
Raeford, NC
Sioux City, IA
Victor Valley, CA
Horse Creek, SC
Raeford, NC
Binghamton, NY
East Side, NY
Rocky Creek, GA

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discussions. Most of the form was filled out during the POTW visit or shortly
thereafter. A copy of the site visit interview form is included in Appendix B.
After returning to the office, the interview notes, site visit interview form and
operations/laboratory data from the plant were incorporated into a written
report of one to two pages, accompanied by a standardized data sheet and a
treatment process schematic. The written reports were sent to the principal
individuals involved in the discussions at each site for their comments, along
with a followup letter of thanks. The comments and corrections to the returned
draft reports were considered before making revisions to the copies included in
this document.
CASE STUDY REPORTS
The twenty nine case study reports are included in Appendix C. The first page of
Appendix C presents an index to the reports.
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SECTION 6
RESULTS
MONITORING
A critical aspect to any successful industrial waste program is a comprehensive
monitoring of industrial discharges, POTW influent and important process
streams within the plant. Numerous options exist regarding such monitoring
programs. The benefits derived by the municipalities in terms of understanding
their influent wastewater characteristics and sources of specific contaminants
are obvious. Monitoring is also performed to provide data from which to develop
local limits and to later evaluate an industry's compliance with those limits.
Industries can utilize rr.onitoring to identify sidestream characteristics and
incorporate the data into in-house conservation, recycle and reuse efforts. Such
an approach can generate positive benefits from a program initially perceived by
industry as costly and unnecessary.
POTW Influent
Most municipalities surveyed and visited on this project now have some form of
influent wastewater monitoring. The most common approach is to install a
composite sampler at the headworks of the plant. State of the art sampling
equipment provides the POTW with three options:
•	hourly sampling and collection in 24 sample containers;
•	composite sampling; and
•	flow-proportioned composite sampling.
Hourly samples provide a means of identifying diurnal fluctuations in wastewater
characteristics. Such an approach can be costly if all 24 samples are analyzed,
but is particularly useful if "midnight dumping" of prohibited substances is
suspected.
Composite sampling involves the collection of a fixed volume of wastewater at
regular intervals into a single, large container. A typical approach is to collect
100 ml every 15 minutes for 24 hours into a 10-liter sample bottle. This is the
most common method of obtaining average daily influent samples. A better
approach is to proportion the sample volume consistent with the influent
volumetric discharge at the time of collection. This technique requires a
feedback signal from an influent flowmeter to the sampler, but results in a
sample that is consistent with the mass loadings to the POTW.
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Other POTW Locations
POTW effluent is generally composite sampled and analyzed in accordance with
NPDES Permit requirements. Operators may, however, select other process
streams within a facility for intermittent monitoring. For example, sampling
primary effluent allows for calculations of loadings to the secondary treatment
system. The response of a biological process is more easily explained if one
knows the specific wastewater feed characteristics, as opposed to assuming a
primary clarifier performance based on influent characteristics.
An informative yet infrequently employed sampling methodology is to evaluate
the strength of sidestream flows, particularly from solids processing. Recycle
flows can add 50 to 100 percent of the influent solids and organics to the liquid
processing trains when inefficient sludge solids capture persists. POTW design
often neglects the impact of recycle streams, a problem magnified when
unanticipated quantities of heavy metals and priority organics are discharged
from industrial sources. While monitoring such sidestreams on a daily or weekly
basis may prove impractical (and costly), periodic sampling and flow
measurement permits mass balancing around solids processing units, and can
provide insight into the presence of substances in the POTW effluent not
necessarily present in the influent.
Recycle flows can be intermittent, or at least shift dependent, and as such are
poor candidates for 24-hour composite sampling. Grab sambling is done by
extracting a representative sample of sufficient quantity to perform the
necessary analytical tests. Some procedures, such as the extraction methods for
oil and grease, must be grab sampled to prevent deposition of the material on the
container over the 24 hour composite period.
Operations Monitoring
In addition to sample collection and analysis throughout a POTW, there are
numerous tools available to the plant operator to monitor the condition and
performance of the facility. Suspended growth biological treatment systems
generally provide more control, and therefore monitoring opportunities, than do
fixed film systems. However, all POTWs have processes that can be easily
checked on a daily basis which can signal the onset of an interference problem.
Making use of the available tools may be the difference between total process
failure and catching the problem before it fully develops.
The operational tools available fall into the following categories:
9 sensory
9 instrumentation/equipment
• analytical -esults
The sensory category refers to what operations personnel observe around the
plant through the senses of sight, sound, touch and smell. Examples of what
operators should typically notice as they work around a POTW are the:
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•	surface appearance of clarifiers;
•	amount and color of foam in aeration tanks;
•	presence of nuisance organisms, insects or odors near fixed film
systems;
•	common odors at each plant location; and
•	sludge and recycle flow appearance at each processing step.
Instrumentation is designed into treatment facilities as an aid to the operations
staff. Whether located at the central control panel or at the piece of equipment
being monitored, digital and dial gage readouts provide instant feedback to an
experienced operator concerning the conditions in the plant. Strip chart
recorders maintain permanent records of the critical parameters such as raw
wastewater feed to identify long-term trends and isolated indiscretions. Despite
the amount of instrumentation and level of sophistication, much of the hardware
is unused or simply ignored by operators because of a perceived complexity
and/or unreliability. Operator distrust of the instruments would not be a
problem if more time was spent in the plant, but the tendency is to remain in the
control room and monitor a control panel for which the operators have little
appreciation. A major thrust of the Hamilton Township, NJ interference
identification program was to require that operators spend a minimum number of
hours each shift "walking the grounds." Such a requirement can result in the
identification of late night spill events that might otherwise go unnoticed until
morning, when it may be too late for the biological processes to recover.
The use of simple portable instruments and equipment while on routine site
inspection can be quite useful to the operator. The use of a device to measure
the depth of sludge in clarifiers may be the best way to learn that a sludge pump
did not operate as expected. Dissolved oxygen, pH, temperature and
conductivity meters can be used to monitor plant performance on a routine basis
with little training or time commitment required.
The final category of operations monitoring deals with the analytical testing
other than what is performed on the wastewater samples, as previously
discussed. Typical analyses are:
•	MLSS, SVI and uptake rates of activated sludge;
•	soluble BOD in each RBC stage;
•	solids content of sludges throughout the plant, especially from the
dewatering process;
•	volatile acids-to-alkalinity ratios in anaerobic digesters;
•	methane content of digester gas; and
•	metals contents of dewatered sludge.
Experienced operations people can sense an upset from small fluctuations in
these data. Isolation of industrial waste problems early in the spill event may
prevent a catastrophic impact to the POTW.
Industrial Discharges
Sewer use ordinances and industrial waste management programs typically
provide for some means of monitoring an industry's discharge to the municipal
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collection system, Such ordinances require measurement of both quantity and
quality of the industrial or combined domestic/industrial flow. Industrial
discharges are either self-monitored by industry with regular reporting
requirements, or else monitoring is handled by the municipality or a contractor
on behalf of the municipality. Municipal expenditures for these programs are
either billed directly to the specific industries or are recovered through
industrial surcharges to the normal sewer use rate.
The quantity of an industrial wastewater can be obtained from:
•	metered water usage;
•	metered water usage corrected for evaporative losses or product
content; or
•	measured sewer flow.
Industries with significant consumptive water usage have found it prudent to
install flow measurement devices in their outfall sewer with continuous
recorders. Pay-back periods of less than one year are not uncommon with this
type of equipment. The discharge quality coupled with the flow volume will
dictate the industry's sewer bill based on a formula contained within the local
sewer use ordinance.
Analytical Testing
Analyses performed on a POTW influent should routinely include BOD, SS and
other conventional pollutants, (such as NH3 and P) contained on the NPDES
Permit. The testing intervals for the priority organics and metals is determined
01. a site-specific basis as a function of permit violations, pretreatment program
requirements, process upsets, types of industrial discharges and budgetary
constraints.
Industries should similarly be monitored for conventional pollutants, with the
testing of other compounds determined by the nature of the specific industrial
waste. In the case of categorical industries, the substances of concern and
pretreatment requirements are already specified by the regulations. For
noncategorical industries, the initial permit application and questionnaire
responses combined with supportive analytical analyses should provide sufficient
information to establish a testing program.
Sewer Use Ordinances
Many of the municipalities visited for this project calculate sewer fees based on
three levels of conventional pollutant (BOD, SS, NH3) concentrations:
•	less than or equal to domestic strength;
•	greater than domestic strength but less than a prohibited limit;
and
•	greater than a prohibited waste strength limit.
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The established limits and parameters included in the ordinances varies from
municipality to municipality as a function of local domestic waste strength and
POTW capacity. If an industry's wastewater falls into the middle category, the
discharge is permitted by the POTW, but a surcharge is applied which is partially
intended to create an economic incentive to the industry for waste load
reduction.
A common alternative approach to the sewer use fee structure described above
is a uniform charge per pound of BOD, SS and/or NII3 discharged to the POTW.
This type of unit cost approach is probably fairest, but requires frequent
sampling of all industry to accurately characterize the wastewater strength. In
these cases, prohibitive limits for various pollutants (such as toxics and
explosives) are still established for the protection of the POTW.
In all municipalities surveyed and visited who had an established wastewater
ordinance and approved pretreatment program, the language was consistent with
the General Pretreatment Regulations (40 CFR Part 403) concerning prohibited
discharges and categorical standards. A key deficiency was in the development
of local limits for nonconventional pollutants from noncategorical industries.
Local limits are perceived by municipalities as being complicated to establish
and politically sensitive to enforce.
Monitoring methods and frequency are also specified by each municipality in its
ordinance. Self monitoring by industry with monthly spot checking by the
municipality is the simplest and least expensive alternative. Such an approach is
only successful when:
•	sampling procedures are clearly outlined and followed;
•	a certified laboratory performs the analytical testing;
•	rigorous reporting requirements are established for the industries;
and
•	spot checking by the municipality, including occasional sample
splitting and testing, be performed on a frequent yet random basis.
The alternative to self monitoring is for the municipality to perform all sampling
and analytical services on a once-per-month or once-per-quarter basis, depending
on the significance of the specific industry to the POTW. Under this scenario,
split samples should be made available to the industry each time they are
sampled to provide them with the opportunity to verify the test results from
which their compliance status and user fees will be determined.
Regardless of the approach taken, the objective of any industrial monitoring
program is to obtain representative analytical results of the wastewater flow and
characteristics. An industry with highly variable quality should be sampled more
frequently than one with a consistent effluent quality. Municipalities tend to be
more accommodating to industries who conform to the requirements of the
ordinance in a spirit of cooperation than to those industries who are secretive
and unyielding. Of the POTWs visited, the most successful efforts at monitoring
and pollutant load reduction occurred where open lines of communication existed
between industry and municipal treatment plant operators.
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INTERFERENCE
As defined in Section 1, the term interference refers to a violation of an NPDES
Permit or a limitation on the ability to dispose of sludge as a direct consequence
of industrial wastewater being discharged to the POTW. While the recognition of
a problem is trivial, attributing that upset or violation to a specific industry or
group of industries can be difficult. Plant superintendents occasionally use
industry as a scapegoat for poor performance, when in fact the problems may be
due to poor operations and maintenance practices. Conversely, public officials
(particularly if elected) are sometimes reluctant to apply too much pressure to
local industry who in many cases are significant employers and taxpayers, even if
directly linked to upsets at the POTW.
Identification of Interference
Officials at POTWs experiencing process upsets and permit violations sometimes
find it convenient to blame industrial discharges for the problems. However, in
many cases the upsets can be traced to design, administration, operation and
maintenance deficiencies at the POTW unrelated to industrial wastewater. The
U.S. EPA has developed a Composite Correction Program (CCP) for use by
POTWs to economically improve the performance of existing facilities. A CCP
has two distinct phases. The evaluation phase attempts to assess the capability
of each unit process and to identify the performance limiting factors in a POTW.
The performance improvement phase is designed to systematically eliminate the
limiting factors and to optimize the operation of the existing facility. The U.S.
EPA has published a handbook to assist POTWs in their evaluation and correction
efforts (Hegg, et al., 1984).
It is incumbent upon POTW personnel to both prove that plant upsets result from
industrial discharges and tc identify the specific source of that upset. This
"burden of proof" provides the necessary justification for a substantial
monitoring program as outlined in a previous subsection. The case study
examples in Section 4 tend to fall into one of three categories regarding
interferences:
1.	A single major industry in town dominates the waste characteristics
at a relatively small POTW.
2.	One or two industries among several are primarily responsible for
waste strength fluctuations in small to medium-sized POTWS.
3.	Industrial wastewater from numerous sources controls the
wastewater feed characteristics, with no single dominant industry.
The first category listed above is by far the easiest situation to deal with from
an identification standpoint. By monitoring the industry's discharge, POTW
influent and effluent and other relevant plant operations, the impact of the
industrial waste on the POTW can be determined. The political ramifications of
category one are more complicated, as such industries can be the largest
employer and taxpayer in a town. A number of the case studies from Section 5
provide examples for this category:
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Bayshorj, NJ
Canandaigua, NY
Denison, TX
Horse Creek Plant, SC
Lake Mills, IA
Maiden Creek Plant, PA
Paris, TX
Raeford, NC
Tollesor., AZ
Victory Valley Plant, CA
Category two corresponds to a less sensitive situation politically, but is a more
difficult interference to trace. The monitoring program may be sufficient if a
large data base exists over a period of time. Unfortunately, when numerous
industries must be tested on a frequent basis, the sampling and analysis costs are
high and difficult to justify with the non-troublesome industries. An alternate
approach is to look for one or two specific pollutants unique to certain
industries. Examples range from odor tracing back through the collection system
to toxicity analyses to the sophisticated backtracking computer program used by
the City of Baltimore. Examples from this category include:
Gurnee, IL	Newark, OH
Hamilton Township, NJ	Patapsco Plant, MD
Hatfield Township, PA	Sioux City, IA
The third and final category generally applies to larger facilities which are less
likely to be susceptible to any particular industrial effluent. As pointed out in
Section 3, the telephone survey indicated that most larger POTNVs are
infrequently affected by industrial wastes and rarely experience interference.
Some exceptions to this rule were, however, identified and are presented in the
case studies. Notable among them are:
Back River Plant, MD
Passaic Valley, NJ
Raleigh, NC
Types of Interference
Interference can generally be divided into two distinct typos: chronic and
isolated. The chronic interference refers to a more or less consistent pattern of
peimit violation or sludge disposal problem characterized by regular pollutant
concentration levels. Chronic interferences result from both continuous and
intermittent discharges. Continuous discharges of toxics can lead to inhibition
of biological process efficiency without a noticeable upset. In contrast,
intermittent discharges manifest themselves in a variety of ways in the
treatment plant processes as observed by the operations monitoring program.
Changes in DO levels, MLSS, SVI, reactor temperature, etc. are indications of
process changes potentially resulting from industrial wastes. Chronic,
intermittent problems tend to produce similar impacts on the PO'l'W from
incident to incident.
Isolated industrial discharge problems tend to product; a more drastic effect on
the POTW, such as complete loss of unit processes. Since biological populations
are not acclimated to either the specific compounds or concentration levels
observed in an isolated discharge, the impact on biological processes is severe
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and rapid, with long recovery periods generally required. Such interferences
commonly affect the effluent quality rather than the stabilized and dewatered
sludge characteristics, although loss of an anaerobic digestor due to slug loads of
heavy metals is not unusual.
The distinction between an isolated and an intermittent discharge is not well
defined. One approach is to consider whether the biological population remains
partially acclimated to the contaminant between incidents. An isolated
discharge would be to a nonacclimated bacterial culture, while an intermittent
waste feed would be discharged to at least a partially acclimated population.
The important difference between the two is the response and rate of recovery
of the biological system. Establishing a maximum recurrence interval for an
intermittent discharge is site specific as a function of the type and strength of
the industrial waste, the type of treatment system affected and the regularity of
the discharge.
Waste haulers and industrial spill incidents makes planning for isolated
interference problems difficult. One approach taken by some municipalities is to
disallow waste haulers from discharging to their POTW. In cases where waste
haulers are allowed, permit requirements and testing procedures have tightened
up considerably over the past few years.
Another approach at the POTW is to have off-line tankage available to re-route
the influent flow and contain the spill contents. Treatment plants that are
currently undergoing renovation (such as Newark, Ohio or Hatfield Township,
Pennsylvania) are considering the usefulness of existing tankage for this purpose.
In order to recognize that such a spill is imminent, however, the POTW must
depend upon the industry for immediate notification of a problem. In-line
monitoring is useful for some problems such as explosivity, pH or temperature,
but many of the toxic compounds would not be detected by instrumentation.
Interfering Compounds
POTW interference can be caused by a wide variety of chemical, biological and
physical factors. Of the chemical factors, the types and concentrations of
industrial wastewater constituents which cause interference are highly variable.
The studies reported in the literature discussing chemical interference/inhibition
range frum research done in the laboratory to studies of actual treatment plant
operations. There has been a substantial body of work published and many
researchers have devoted a great deal of effort to these types of studies.
However, to draw definitive, broadly based conclusions on pollutant
concentrations which cause ir.terference/inhibition of biological systems is at
best unsound and at worst, impossible.
An attempt has been made to synthesize the available information on the types
and concentrations of pollutants and compounds which inhibit biological
treatment systems and present it in a manner that is of use in determining likely
POTW interfering levels. Tables 13-15 present ranges of concentrations for
metal, organic, and conventional and inorganic pollutants which inhibit
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acclimated biological processes. The references used in developing these tables
are:
•	Revised Pretreatment Guidelines (JRB Associates, 1981a);
•	Literature Study of the Biodegradability of Chemicals in Water -
Volume 1 (Geating, 981);
•	Biodegradation an Treatability of Specific Pollutants (Earth and
Bunch, 1979);
•	the literature review presented in Section 3 of this report; and
•	data obtained from the case studies.
The wide range of concentrations presented in Tables 13-15 is a result of the
significant amount of data in the literature that are apparently contradictory. In
general, it can be said that this situation is a result of the method of measuring
inhibition and the different conditions surrounding the biological process.
Unfortunately, some study conditions are seldom documented in the literature.
The most important conditions that affect biological inhibition are: biomass
characteristics, pH, temperature, synergism (or antagonism) and acclimation.
There are various ways of measuring inhibition and the fact that different
researchers use different methods results in a range of published "inhibiting
concentrations", even for nearly identical study conditions. The two most
typical methods of determining activated sludge inhibition are by measuring
1) decreases in COD or BOD removal or 2) decreases in oxygen utilization rates
as compared to controls. Threshold inhibition levels as measured by these two
methods are usually defined differently by individual researchers, but are most
typically set at the 10-50 percent range. Anaerobic treatment inhibition is
typically defined as increased volatile acid levels or decreased methane
generation, but once again the threshold levels are variously defined.
Nitrification inhibition is specified as a certain decrease in the degree of
ammonia conversion.
For most studies biomass characteristics are not typified, except as it relates tc
acclimation. The diverse biomass population is likely to be very different from
one reported study to the next and this will have a significant impact on the
inhibitory concentration levels of pollutants. pH and temperature generally are
reported study conditions in the literature. Once again the actual conditions
vary dramatically from study to study, with the result being that inconsistent
values are reported. pH plays a particularly important role in metal-caused
inhibition. pH affects the solubility of metal ions, and it is the soluble metal
species that is toxic to microorganisms. Synergism, or the increase in the
inhibitory effect of one substance by the presence of another, is most important
when considering combinations of metals. Toxic organics do not exhibit this
effect as often as metals. On the other hand, some compounds are antagonistic
towards each other, decreasing the inhibitory effect of either compound alone.
Good examples are chelating agents, such as EDTA, which are antagonistic
toward inetal ions and reduce their toxic effects.
Acclimation, which is a biological phenomenon, is an important factor which
must be considered to understand the inhibitory effect of pollutants. Biomass
characteristics (relative populations) will change with time so that a given
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pollutant will become less toxic to the biomass as a whole and may in fact
become a significant substrate. The values reported in Tables 13-15 are in
general for acclimated biological systems. Some studies have been done and
reported in the literature on the effects of pollutants on non-acclimated
biological systems, as wel! as what could be termed shock loading or short-term
non-acclimated studies. These studies were not included in developing
Tables 13-15 because inconsistencies between studies were even more
pronounced than for acclimated studies. Non-acclimated systems can in
general withstand much lower pollutant concentrations before Leing inhibited
and from this standpoint, the lower values in Tables 13-15 could possibly be used
to estimate the upper limits of inhibition for unacclimated systems. Russell,
et al. (1983) present a good summary of the non-acclimated studies performed
primarily during the 1960s and early 1970s.
Table 13 presents a range of metal pollutant concentrations inhibiting
acclimated biological processes. The literature is more abundant and consistent
in reporting inhibitory concentrations of metals than for organic compounds.
The most significant factors affecting the range of reported values in Table 13
are pH and the method of reporting inhibition, both of which were discussed
previously.
Table 14 presents ranges of concentrations for toxic organic compounds which
inhibit acclimated biological systems. A dearth of information exists on the
effects of toxic organics on fixed film processes and so this column was
eliminated from the table. Scattered data exists for other organic compounds,
often only available from one study. To present information in a condensed,
useable and consistent manner, organic compounds were classified into eight
broad categories and the information on inhibitory pollutant concentrations was
synthesized within that structure. The premise was that compounds of similar
structure or characteristics would inhibit biological processes at similar
concentration levels. This approach was found to be fairly consistent to the
levels shown in Table 14. However it is extremely important to note that the
categories in Table 14 are very broad and the concentration ranges presented are
simply typical reported values for some compounds and should not be construed
as defining a definitive inhibition range for all compounds that might fall into
the broad classifications. Appendix A lists the compounds that fall into these
broad classifications. Some compounds fit more than one classification, but an
attempt has been made to place these compounds into the most appropriate
category.
Additional explanation for several of the compound types is in order. It appeared
from the literature that the following generalizations could also be made:
•	multi-chlorinated aromatics inhibited activated sludge at much lower
concentrations than did other aromatics, with threshold levels
generally less than 1 mg/1; and
•	for oxygenated compounds, alcohols were generally not inhibitory to
activated sludge at levels below 1,000 mg/1 and acids were inhibitory
to anaerobic processes at levels less than 10 mg/1.
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TABLE 13
METAL CONCENTRATIONS INHIBITING
ACCLIMATED BIOLOGICAL PROCESSES
(in mg/1)
Biological Process

Activated

Fixed

Metal
Sludge
Nitrification
Film
Anaerobic
Arsenic
0.04 - 0.4
-
290
0.1 - 1.0
Boron
0.05 - 10
-
-
-
Cadmium
0.5 - 10
5-9
5-20
0.02 - 1.0
Calcium
2,500
-
-
-
Chromium
0.1 - 20
0.25 - 1.0
50
1.5 - 50
Copper
0.1 - 1.0
0.05 - 0.5
25 - 50
1.0 - 100
Cyanide
0.05 - 20
0.3 - 20
-
0.10 - 1.0
Iron
500


-
Lead
0.10 - 10
0.5 - 1.7
-
50 - 70
Manganese
10
-
-
-
Magnesium
-
50
-
1,000
Mercury
0.1 - 5.0
2 - 12.5
-
-
Nickel
1 - 5
1 - 5
-
2 - 200
Silver
0.03 - 0.05
0.25
-
-
Sodium
-
-
-
3,500
Tin
-
-
-
9
Vanadium
20
-
-
-
Zinc
0.30 - 20
0.01 - 1
-
5-10
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TABLE 14
ORGANIC COMPOUND CONCENTRATIONS INHIBITING
ACCLIMATED BIOLOGICAL PROCESSES
(in mg/1)
Biological Process

Activated


Compound Type
Sludge
Nitrification
Anaerobic
Agricultural Chemicals
Common Pesticides
0.05 - 0.10


Lindane
5 - 10
-
-
Aromatics
50-150
-
100 - 870
Halogenated Aliphatics
150 - 250
< 0.1 - 10
1 - 20
Nitrogen Compounds
1 - 500
0.1 - 100
5 - 500
Oxygenated Compounds
120 - 500
-
50 - 1,000
Phenols
100 - 1,000
1 - 10
100 - 200
Chlorophenols
Nitrophenols
5 - 100
50 - 200
—
100
100
Methylphenols
Phthalates
Polynuclear Aromatic
Hydrocarbons
500 - 2,500*
5-50
*Unacclimated
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TABLE 15
CONVENTIONAL POLLUTANT AND INORGANIC COMPOUND
CONCENTRATIONS INHIBITNG
ACCLIMATED BIOLOGICAL PROCESSES
(in mg/1, except pH)
Biological Process
Compound Type
Activated
Sludge
Nitrification
Anaerobic
Alkalinity
Ammonia
Chloride
Iodine
Iron Salts
pH
Sulfate
Sulfide
Surfactants
1,600
480
10
100
> (11-12)
25 - 50
100 - 500
180
<(7.0 - 8.5)
1,500 - 8,000
500
500 - 1,000
50 - 100
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Table 15 presents information on conventional pollutants and inorganic
compounds inhibitory to acclimated biological systems. Information on
inhibitory concentrations is limited, possibly due in part to the perception that
conventional and inorganic pollutants are not inhibitory to biological systems.
Conventional organic pollutants (BOD, COD, etc.) and ammonia (for
nitrification) are not presented.
Toxicity Testing
All states now operate with water quality regulations that prohibit the discharge
of toxic substances in toxic amounts into natural watercourses. Such regulations
are applicable to the point source effluents from POTWs, which has prompted
EPA and the state agencies to encourage, and in some of the more recent
permits, require municipalities to perform biomonitoring on their effluent.
What this type of effluent toxicity testing actually measures is the "pass
through" pollution from a POTW, and is therefore not relevant to this study.
However, toxicity testing of industrial discharges, particularly from new sources,
might prove useful in evaluating the impact of that wastewater on the POTW.
Biomonitoring procedures utilize certain species of fish, such as fathead minnows
or rainbow trout, to indicate the level of toxicity of a particular wastewater.
The rate of survival in varying concentrations of pollutants over a 24 to 96-hour
test period can be measured (expressed as an LC50, or median lethal concentra-
tion), and comparisons made between different chemicals or wastewaters. While
biomonitoring of this type might well rank industrial discharges in terms of
toxicity, the results would do little to predict the impact of such discharges on a
POTW.
Recently, a number of acute toxicity test procedures have been developed which
have applications to industrial wastewater evaluation and control. The most
straightforward procedure is to add varying concentrations of an industrial
wastewater to a BOD bottle containing an active biological culture from the
secondary treatment system. A DO meter equipped with a BOD probe can be
used to measure the oxygen uptake rate after the sample is saturated with
oxygen. If the industrial wastewater is toxic, increased doses will result in
reduced oxygen utilization due to the inhibition of the bacterial oxidation. A
similar approach using respirometers allows for the use of larger reactors (up to
10-liters), continuous oxygen feed and strip-chart recording of the uptake rate
with time.
Recent variations of the respirometry approach utilize special cultures of
microorganisms, instead of the POTW bacteria, as more j. -ecise predictors of
toxic effects. One manufacturer uses specially prepared and packaged bacterial
cultures in conjunction with a DO meter to plot families of inhibition curves and
to develop an LC50 value analogous to those obtained by bioassay testing. A
second technique uses photo-luminescent marine microorganisms, whose light
output decreases proportionally to the level of toxic shock when fed varying
concentrations of industrial wastewater. This approach has been used exten-
sively in Baltimore, Maryland and Chattanooga, Tennessee to evaluate the
toxicity of influent wastewaters to the POTW.
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A comparison between the fish bioassay technique and the use of photo-
luminescent organisms (Cawley, 1981) indicated that despite some limitations,
the latter procedure offers a number of advantages over the former in terms of
speed (15 minutes versus 24 to 96 hours) and cost-effectiveness. The author
does not suggest that the fish bioassay procedures be abandoned, but does
indicate that a correlation between the two techniques would be an important
breakthrough in the years ahead.
Rapid toxicity testing procedures will he valuable tools for identification of
interference sources as they gain acceptance by municipalities. A toxic impact
can be traced upstream '.nrough a collection system very rapidly when the test
procedure takes less than 30 minutes. Such an approach to interference tracing
is only useful if the troublesome industry discharges toxicants. Municipalities
must continue to rely on more conventional monitoring practices for upsets
resulting from non-toxic contamination.
MITIGATION
The success of any effort to mitigate interference is dependent to a great extent
on the characteristics of the pollutant(s) causing the interference, the
characteristics of the treatment plant (size, biological process, etc.) and the
type of mitigation attempted. It is important to note that while some mitigation
efforts can probably be utilized with success on a wide variety of interference
cases (pretreatment for instance), other measures may be more specific to a
particular pollutant or set of operating conditions. The bottom line is that any
POTW experiencing interference has a unique set of circumstances and
conditions that may require unique mitigation efforts. The purpose for
describing successful interference mitigation efforts is that they may in some
way be adapted to other POTWs with similar characteristics.
The information on mitigation efforts from the previous three chapters has been
synthesized and categorized under three major headings:
•	Treatment Plant Control
•	Pretreatment and Source Control
•	Legal and Enforcement Remedies
Treatment Plant Control refers to mitigation efforts that are implemented at
the POTW and are as simple as biological process control, or as extensive as new
or modified treatment processes. Pretreatment and Source Control describes
some of the elements of a successful pretreatment or source control program for
mitigating interferences. Legal and enforcement remedies include fines,
litigation and sewer disconnection.
Treatment Plant Control
Mitigation of the effects of interfering industrial pollutants is generally first
attempted by modifications of some type at the POTW. In the short terra (and
possibly long term) these measures, typically plant operation modifications, can
prevent an interference or lessen its impact. Other long-term efforts to
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mitigate interferences at POTWs include capital improvements or modifications
of a permanent nature.
Plant Operations Modifications —
The first attempt to mitigate the deleterious effects of industrial pollutants at a
POTW usually consists of modifications to plant operations. These measures
might be in response to a spill of an industrial contaminant, or to a chronic
indust ial waste problem, but typically can be categorized into two basic types:
biological process control and treatment step modifications.
Biological Process Control -- Many investigator's work in the literature review
reported successful prevention or reduction of interferences by adjusting
activated sludge process parameters such as the mean cell residence time
(MCRT), mixed liquor suspended solids (MLSS) and food to microorganism ratio
(F/M). This same conclusion was borne out in discussions with many operating
personnel during the case study site visits reported in. Chapter 4. Process control
of other biological systems like trickling filters is not as easily accomplished, but
parameters such as recirculation ratio can be modified.
The following changes to activated sludge process parameters have been
observed to mitigate the effects of industrial pollutants on a biological system.
Although they are interrelated, they are addressed separately because any one
may be typically utilized as a process control tool at a POTW.
1.	Increase the Mean Cell Residence Time. Increasing the MCRT (sludge age)
has been shown to have the effect of reducing the toxicity of all forms of
industrial contaminants. Biological systems with higher MCRTs have been
observed to acclimate faster to a foreign pollutant than systems with low
MCRTs. By increasing the MCRT at the first sign of a possible toxic upset,
(by decreasing the solids wasting rate) the effect of any toxicant will be
less than if no action is taken.
2.	Increase the Mixed Liquor Suspended Solids. High mixed liquor suspended
solids (MLSS) concentrations have been shown to offset some of the effects
of industrial pollutants. A high MLSS provides the best conditions for bio-
absorption and acclimation to a toxic substrate. Increasing the sludge
return rate to the aeration basin at the first indication of toxic upset,
while at the same time bypassing any remaining toxic influent around the
aeration basins, will lessen the impact of a short term upset and cause
quicker biomass acclimation to a long term problem.
3.	Decrease the Food to Microorganism Ratio. This parameter is directly
related to both the MCRT and the MLSS. It has been observed thai
decreasing the F/M causes improved biodegradation of toxic contaminants,
and expedites biomass acclimation.
The process control modifications just described appear to apply as well to
activated sludge systems attempting to achieve nitrification as they do to
strictly carbonaceous removal systems. In general, increasing the MCRT and
MLSS, and decreasing the F/M is beneficial for treating any type of industrial
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contaminant, whether it is a toxic metal, U'-.ic organic or high-strength
conventional pollutant.
Fixed film biological processes do not lend themselves to the same type of
process control measures as suspended growth systems, but several techniques
have been employed with some success. Varying the amount and point of
recirculation in a trickling filter can modify the effect of industrial pollutants.
Recirculating secondary clarifier effluent is a means of achieving the greatest
diluting effect, which may be desirable for high-strength organic waste or toxics.
Should excessive biomass sloughing be a problem due to toxic pollutants,
returning secondary clarifier underflow may htlp in maintaining a proper biomass
population.
Treatment step operations modifications A further mdans of mitigating the
effects of industrial pollutants on POTWs is through modifying the operation of
existing treatment steco. Activated sludge systems are often designed to
operate in several different "modes" (i.e. step aeration, contact stabilization,
etc.) by providing the appropriate physical layout. Some modes oi operation
have been shown to be more successful than others at mitigating the effects of
industrial contaminants, particularly those dosed ir. highly variable concentra-
tions. It has been shown at the laboratory and plant-scale that extended aeration
and step aeration (step feed) are generally more stable than complete mix and
conventional activated sludge. Some contradiction exists as to whether conven-
tional plug flow or complete mix activated sludge treatment is more resistant to
industrial contaminants, but it appears that complete mix generally provides
more consistent treatment, particularly under shock loading conditions. The
contact stabilization mode has been reported as being less successful at trc..:ing
industrial pollutants than other modes, particularly when the organic matter is
predominantly soluble and waste strength fluctuations are common.
A successful means of mitigating the effects of industrial contaminants on any
biological treatment process is through the use of staged treatment. Many
treatment systems have realized improved conventional and industrial pollutani
removal when switching from parallel treatment to series treatment. For
example, two aeration basins operating in series are generally more successful at
mitigating the effects of industrial contaminants than the same two basins
operating in parallel. The same principles have been observed to apply equally to
fixed film processes and fixed film/suspended growth combinations.
A typical response of a fixed film process to industrial waste stressing is
excessive biomass growth, resulting in clogged media and reduced treatment
efficiency. Treatment is generally improved if the biomass population (thick-
ness) can be reduced, and several modifications have been successful in achieving
this end. By increasing or altering shearing forces, biomass sloughing increases.
This can be accomplished by altering the direction of flow through RBCs and
submerged fixed film basins, or by increasing or a.Ur.ring the aeration pattern (if
any) in the basins. A second means of inducing increased biomass sloughing is
through chemical addition, but this approach is potentially dangerous and should
only be attempted under the guidance of professionals skilled in the use of such
chemicals.
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Treatment Plant Modifications --
The most permanent type of industrial pollutant mitigation efforts corne in the
form of physical addition to or modification of the treatment system. Successful
modification of treatment plants for industrial waste effects mitigation have
included f.he addition of new plant facilities such as flow equalization and
physicf.l/chemical treatment steps, the addition of facilities for adding
chemicals to existing treatment processes, and the modification of existing
biological systems (i.e. converting to oxygen activated sludge and replacing old
rock trickling filter media).
Adding flow equalization prior to biological treatment units has the effect of
dampening any slug or diurnal loads of non-compatible or high-strength industrial
contaminants entering o treatment plant. Pollutants that periodically enter a
POTW in inhibiting concentrations can be diluted by flow equalization to non-
inhibitory levels and thus, not adversely impact the biological system.
Some POTWs use a variation of this principle with success, especially when toxic
metal pollutants are involved. pH and conductivity of influent wastewater are
measured and recorded continuously in the influenL. When the pH drops or
conductivity rises drastically, possibly indicating an increased heavy metal level,
the influent flow is diverted to a holding basin until such time that the metal
concentrations in the influent return to normal. At that time, the diverted
wastewater can be bled back to the influent wastestream in a manner such that
metal concentrations are diluted and do no* inhibit the biological system. This
type of technique may become more useful in the future as continuously
recording specific ion electrodes are developed for more pollutants.
Other treatment steps that r.'ight be added depend on the interfering industrial
pollutant. The addition of flotation/skimming tanks arc beneficial for removing
pollutants like oils, greases or other water immiscible compounds. Separate
settling basins may be beneficial in some cases for chemical treatment to
precipitate metals or cause coagulation of unsettleable solids.
The addition of chemicals or nutrients to the wastewater stream in existing
treatment steps has been shown in many instances to mitigate some industrial
pollutant's effects. The following chemicals or additives have been shown to
improve industrial wastestream treatability or biological process stability for
one reason or another:
•
chlorine
•
phosphorus
9
nitrogen
•
lime (pH control)
•
polymers
•
alum and ferric chloride
•
powdered activated carbon
Chlorine has been shown t,o be successful in controlling bulking sludge caused by
industrial pollutants from such industries as textiles, and wood and paper
products. Points of chlorine addition vary, but best results generally occur when
chlorine is added to the aeration basin effluent or RAS.
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Phosphorus addition and, to a lesser extent, sulfur and nitrogen addition
occasionally improves biological treatment and sludge settleability of industrial
wastewater with high carbonaceous content. In general, better treatment and
settleability is attributed to correcting a nutrient deficient condition resulting
from a high industrial/domestic wastewater ratio.
Lime is sometimes successful at mitigating the effects of some heavy metals on
activated sludge systems. Addition of lime before primary treatment has the
effect of raising the pH which improves precipitation of heavy metals in primary
clarifiers. Optimum pH ranges exist for metal insolubilities, but these ranges
are affected by many factors ar.d are therefore system dependent.
Polymers and inorganic coagulants such as alum and ferric chloride are
introduced to POTW wastestreams in part to help mitigate the effects of
industrial pollutants. Added prior to primary treatment, the coagulants improve
primary sedimentation and may increase the removal of toxic pollutants before
they reach the aeration basin. Added after the aeration basin, the coagulant aid?
can assist in controlling bulking siudge and reducing effluent suspended solids.
Jar testing is an important part of any chemical addition program as the best
means of determining optimum dosages.
The addition of powdered activated carbon to an activated sludge unit has been
successful at reducing the effect of toxic organic chemicals. By providing
adsorption sites, the organic pollutants are removed by the activated carbon.
The activated carbon also improves sludge settleability by providing dense floe
nuclei. A patented process exists employing this treatment concept.
Another type of treatment plant modification that has seen some success at
mitigating industrial interference is the replacement of an existing activated
sludge unit with oxygen activated sludge. Pure oxygen activated sludge nas been
reported to be a more biologically stable process than conventional air facilities
when responding to toxic or high-strength organic loadings. In addition, sludge
settleability is reported to be improved. Increasing the efficiency of oxygen
transfer in an aeration basin will help mitigate the effects of high-strength
conventional pollutants. Retrofitting existing coarse bubble or turbine aeration
units with fine bubble units may work to provide the added treatment capacity
necessary to treat a high-sti-ength waste.
Pretreatment and Source Control
Pretreatment and source control of interfering industrial pollutants is the most
direct and efficient way of mitigating the effects of industrial pollutants
because the cause of the interference never reaches the POTW. This reasoning
is the impetus for the U.S. EPA promulgated General Pretreatmr.it Regulations
which specify the guidelines under which municipalities must develop pretreat-
ment programs. It is not the intent of this report to discuss pretreatment
guidelines, complete program development or details of industrial treatment
processes. Rather, this discussion is intended to document elements important
to bringing about pollutant source control, whether as part of a municipal/indus-
trial cooperative agreement or a fully approved pretreatment program. The
discussions are divided into three major headings:
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•	Industrial Waste Discharge Agreement Development
•	Industrial Pretreatment Works
•	Industrial Waste Discharge Agreement Monitoring and Enforcement
Industrial Waste Discharge Agreement Development —
With the exception of the categorical industries who are required to construct
applicable pretreatment facilities, industries are not likely to voluntarily reduce
the quantity or improve the quality of their wastewater. It is incumbent upon the
municipalities to convince their industries of the importance of an effective
industrial waste management program to the proper operation of a POTW.
Judging from comments made during the 29 case study site visits, the single
most important element necessary to realize successful implementation of
source control (pretreatment) is cooperation between industry and the POTW. It
was frequently stated by POTW officials that without the cooperation of
industry, their source control programs would not be as successful, nor would it
have been as quickly and easily implemented.
Although cooperation appears to be the key to successfully implementing source
control (and thus mitigating interference at the POTW), a number of specific
program elements have proven to be important:
•	involve industry from the inception;
•	treat industry fairly and equitably; and
•	set local discharge limits.
It is important to solicit the input of industry when initiating or revising source
control measures. Communicating the hows and whys of a source control
program is tied to the emphasis on trust and cooperation. In some cases
industries do not realize they are capable of impacting a POTW, particularly if
they discharge high-strength conventional pollutants which they perceive to be
compatible.
Industrial involvement in all phases of a pretreatment program is essential. In
the Paris, Texas case study described in Section 4, the municipality firmly upheld
the regulations, yet demonstrated a reasonable approach to their program by
establishing fair milestone dates in the industrial compliance schedules. An
important element is that all industries were treated in an equitable manner
within a specified size classification. That is, no industry was singled out as
being the "biggest problem" or "worst offender". If em industry perceives a
POTW to be singling them out, they are very likely not to cooperate. It is
important to include all industries in a source control program whether they are
presently a problem or not.
The final point about developing and setting local limits is also illustrated by the
Paris example. Industry will respond most favorably to discharge limits when the
allocation of a treatment plants capacity for a particular pollutant is done in a
fair and equitable manner, based on a rational wastestream monitoring program.
If pollutant discharge limits for non-categorical industries are arbitrarily set,
resistance to these limits are more likely than if they are developed rationally
based on the treatment capacity of the POTW, the impact on the receiving
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stream or sludge quality considerations. Setting local limits for categorical
industries may also be perceived better by industries than arbitrarily applying
federal standards, despite the fact that local limits would possibly be more
stringent. A rational, methodical approach to setting industrial waste discharge
limits will be most acceptable to industry.
Industrial Pre treatment Works —
A source control agreement sets the framework for the mitigation of industrial
interference, but it is the industrial process modifications or added industrial
treatment steps which result that actually effect the change. There exists a
wide variety of treatment processes applicable to industrial pretreatment,
depending on the wastestream pollutants, the volume of the wastestream and the
extent to which the waste must be treated. The application of specific
treatment streams will not be discussed here, as it is not in the scope of work.
However, typical municipal treatment processes can be applied to industrial
wastestreams, and the comments in that portion of this section apply to
industrial plants as well.
In many cases where industries have been forced to alter waste discharges, it has
been found that wastewater flow equalization, pH neutralization or simple
process modifications have been all that are necessary to meet discharge limits
and eliminate interferences. Process modifications or wastestream recovery
processes (such as for metals) have in some cases ended up saving industries
money in addition to reducing pollutant loads.
Industrial Waste Agreement Monitoring and Enforcement —
With a source control program developed, monitoring of industries and enforce-
ment of the industrial waste discharge permits (or sewer use ordinance) is
designed to prevent and control industries from causing interferences. The
extent to which this works is greatly dependent on the way in which the source
control program was developed — many of the elements of successful source
control development are equally as important in monitoring. Details on
wastestream monitoring, detection of interferences and tracking the sources of
an interference back through a sewer system are found elsewhere in this
document. The following points are monitoring and enforcement program
elements that have been found to be important to the success of some programs:
•	Continued industry/POTW communication
•	Frequent industrial discharge sampling and analysis
•	Development of an effective spill prevention program
•	Consistent and appropriate response to industry discharge violations
•	Listing of industrial discharge violators in a local newspaper or
publication
Communication and the exchange of information must continue between the
POTW and industries even after the pretreatment program has been developed.
These open lines of communication can often divert an impending problem or
lessen its effect. As an example, many of the 29 case study POTWs have
received calls from industries when an accidental pollutant spill has occurred,
thus warning operators of an impending upset condition and allowing them to
possibly take precautionary measures.
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~t is in the best interests of any medium to large municipality to develop an
ac idental spill prevention program (ASPP). The EPA has funded a Guidance
Manual for POTWs on the subject. The purpose of an ASPP is to provide "...a set
of procedures and a regulatory structure that will minimize the chance that
accidential spills of toxic materials will damage a municipality's collection
system or treatment plant" (SAIC, 1986). The principal elements of an effective
municipal ASPP are:
•	identification of potential sources and types of spill materials;
•	adequate regulatory control;
•	POTW review of industrial user spill prevention programs;
•	complete emergency response procedures; and
•	documentation of the development strategy.
Industrial users should be primarily concerned with spill prevention, containment
and cleanup procedures in their ASPP.
Consistency and fairness are stressed throughout these discussions on source
control measures and they are particulary important for the response to
industrial discharge violators. A consistent approach to violation punishment,
tailored to the specific industries in a system, will set the stage for fewer
complaints and less litigation because of violations.
Finally, as was mentioned earlier, public pressure goes a long way toward
inducing industries to comply with discharge permits. Publishing the names of
industrial waste violators in local newspapers is specified by EPA to be part of a
permitted pretreatment program, but can also be an element of any source
control program. For some industries, the possibility of adverse public reaction
arising from their names being published as a "polluter" was the single most
effective deterrent to discharge permit violation. This is particularly true of
retail sales industries, where the company name is listed on product labels to be
selected or passed over by the consuming public.
Legal and Enforcement Remedies
Thr. final methods of mitigating POTW interference are those formal remedies
used when less formal attempts to solve the problems in a cooperative fashion
have failed. Often only the threat of their use is needed for other actions to
resolve an issue. As defined here, the three types of measures available to most
POTWs to attempt to stop an interference are: fine the nuisance industry, sue
the nuisance industry or disconnect them from the sewer system altogether.
These three measures are in some way tied to a sewer use ordinance, industrial
waste permit, or some other sort of agreement or law regulating discharges to
public sewers.
Fines —
After noncompliance warnings and efforts to cause industries to pretreat their
wastes properly have failed, the enforcement option most POTWs first turn to is
fines (provided regulations exist for this measure). Fines can be structured many
ways, but to be effective must be linked to the severity of the interference
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caused, or in proportion to the quantity of interfering pollutant. Fines are
typically not intended to be a means of actually correcting an interference
problem, but rather a measure to economically pressure an industry into
providing acceptable pretreatment. The intent is clearly not to put industry out
of business, however a POTW needs to have methods available to protect itself
from uncooperative industrial polluters.
Litigation —
POTW-initiated litigation (including public hearings) can be a first step in
causing an industry to comply with a sewer use ordinance or other regulations, or
it can be a further attempt to cause compliance after fines have failed to bring
about the desired result. Litigation is sometimes a necessary step before
proceeding to sewer disconnection, or it may be a way of enlisting public
pressure to bring about a change. Litigation brings media attention and public
pressure and has caused more than one industry to implement or improve
pretreatment when pressure from a sewer authority has failed. In some cases
(such as Bayshore, New Jersey), litigation is instituted to collect unpaid fines,
which can be a sizeable sum of money if the delinquent industry is a significant
contributor.
Sewer disconnection —
If litigation does not precede a sewer disconnection, disconnecting an industrial
sewer line is likely to bring about litigation. The most drastic of all measures,
disconnection will eliminate an interfering pollutant, but will significantly
reduce the likelihood of a negotiated settlement being reached. Sewer discon-
nection should be judiciously considered before being implemented, but is an
option available to POTWs under extreme circumstances.
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REFERENCES
Abeliovich, A. and Azov, Y. (1976) "Toxicity of Ammonia to Algae in Sewage
Oxidation Ponds." Appl. & Environ.^Microbiol. 31:801-806.
Andersen, D. R. (1981) "Pharmaceutical Wastewater Treatment: A Case Study."
Proc. 35th Ind. Waste Conf.' Ann Arbor Science, Ann Arbor, Michigan. 456-462.
Argaman, Y., Hucks, C. E. and Shelby, S. E., Jr. (1984) "The Effects of Organotin
on the Activated Sludge Process." Water Res. 18:535-542.
Austin, S., Yunt, F. and Wuerdeman, D. (1981) "Parallel Evaluation of Air and
Oxygen-Activated Sludge." EPA-600/2-81-155. U.S. EPA, Cincinnati, Ohio.
43pp.
Avendt., R. J. and Avendt, J. B. (1983) "Municipal Activated Sludge Treatment
of Organometallic Pesticide Residues." Proc. 15th Mid-Atlantic Ind. Waste
Conf.1; Butterworth Publ.£ Boston, MA. 619-628.
Bagby, M. M. and Sherrard, J. H. (1981) "Combined Effects of Cadmium and
Nickel on the Activated Sludge Process." Journal WPCF. 53:1609—1619-
Bailey, S. W. and Zimomra, D. C. (1981) "Nationwide Survey of Heavy Metals in
Municipal Sludge." Proc. 13th Mid-Atlantic Ind. Waste Conf. Ann Arbor
Publishing, Ann Arbor, Michigan. 15-25.
Baird. R., Carmona, L. and Jenkins, R. L. (1977) "Behavior of Benzidine and
Other Aromatic Amines in Aerobic Wastewater Treatment." Journal WPCF.
49:1609-1615.
Bard, C. C.f Murphy, J. J., Stone, D. L. and Terhaar, C. J. (1976) "Silver in
Photoprocessing Effluents." Journal WPCF. 48:389-394.
Barth, E. F., and Bunch, R. L. (19"9) "Biodegradation and Treatability of Specific
Pollutants." EPA-600/9-79-034. U.S. EPA, Cincinnati, Ohio. 60 pp.
Bauer, G. L., Hardie, M.^G.'and Vollstedt, T. J. (1981) "Biophysical Treatment of
Coke Plant Wastewaters." Proc. 35th Ind. Waste Conf. Ann Arbor Publishing,
Ann Arbor, Michigan. 332-342.
Baxter, R. A., Gilbert, P. E., Lidgett, R. A., Mainprize, J. H. and Vodden, H. A.
(1975) "The Degradation of Poylchlorinated Biphenyls by Micro-Organisms." The
Science of the Total Envir. 4:53-61.
102

-------
Baxter, J. C., Aguiler, M. and Brown, K. (1983) "Heavy Metals and Persistent
Organics at a Sewage Sludge Disposal Site." J. Environ. Qual. 12:311-316
Beckett, P. H. T., Phil, D. and Davis, R. D. (1982) "Heavy Metals in Sludge - Are
Their Toxic Effects Additive?" Water Pollution Control 1982. Water Research
Center, Stevenage, Herts. 112-119.
Beckwith, E., Greaves, K., Meyer, M.A., Vasudevan, C., Aulenbach, D.B. and
Clesceri, N.L (1983) "Removal of Mercury in POTW Using Aluminum Salts for
Phosphorus Removal." Proc.f 15th Mid-Atlantic Ind. Waste Conf. Butterworth
Publishers, Boston, Massachusetts. 293-303.
Bedard, R.G. (1976) "Biodegradability of Organic Compounds." M.S.. Thesis.
Univ. of Connecticut. Storrs, Connecticut. 84 pp.
Beg, S. A., Siddiqi, R. H. and Ilias, S. (1981) "Effect of Toxicants on Biological
Nitrification for Treatment of Ferttilizer Industry Wastewater." Froc. 35th Ind.
Waste Conf. Ann Arbor Publishing, Ann Arbor, Michigan. 826-834.
Beg, S. A., Siddiqi, R. H. and Ilias, S. (1982) "Inhibition of Nitrification by
Arsenic, Chromium and Fluoride." Journal WPCF. 54:482-488.
Beg, S. A., and Atiqullah, M. (1983) "Interactions of Noncompetitive Inhibitors on
the Nitrification Process." Journal WPCF. 55:1080-1086.
Belly, R. T., Lauff, J. J. and Goodhue, C. T. (1975) "Degradation of Ethyltne-
diaminetetracetic Acid by Microbial Populations from an Aerated Lagoon.?
Appl. Microb. 29:787-794.
Benjamin, M.fM. and Leckie, J. O. (1981) "Competitive Adsorption of Cd, Cu, Zn,
and Pb on Amorphous Iron Oxyhydroxide." J. Colloid and Interface Sci.
83:410-419.
Bhattacharyya, D., Jumawan, A.B. and Grieves, R.B. (1979) "Charged Membrane
Ultrafiltration of Heavy Metals from Nonferrous Metal." Journal WPCF.
51:176-186.
Bhattacharyya, D., Kermode, R.I. and Dickinson, R.L. (1983) "Coal Gasification
Process Wastewater Reusability: Separation of Organics by Membranes."
Environ. Prog. 2:38-46.
Biesinger, M. G.'and Jenkins, D. (1981) "Brewery Wastewater Treatment Without
Activated Sludge Bulking Problems." Proc. 35th Industrial Waste Conf. Ann
Arbor Science, Ann Arbor, Michigan. 596-609.
Bieszkiewicz, E. and Hoszowski, A. (1978) "Effect of Copper and Tri- and
Hexavalent Chromium on the Work of an Activated Sludge." Acta Microbiol.
Polonica. 27:147-153.
Bieszkiewicz, E., Hoi, D.'V. and Matusiak, K. (1979) "Effect of Methyl Alcohol
and Ethylene Glycol on the Work of Activated Sludge." Acta Microbiol.
Polonica. 28:255-260.
103

-------
Bishop, D. F. (1982) "The Role of Municipal Wastewater Treatment in Control of
Toxics." EPA-600/D-82-360. U.S. EPA, Cincinnati, Ohio. 38 pp.
Blevins, W.'T. (1982) "Factors Affecting Floe Formation and Bulking in the
Activated Sludge Process for Treatment of Textile Waste Waters." Office of
Water Research and Technology, U.S. Dept of Interior, Washington, D.C. 26 pp.
Blumenschein, C. D. and Helwick, R. (1983) "Removal of Chlorinated Organics
Utilizing Rotating Biological Contactors." Proc. 44th Annugl Mtg., Int'l Water
Conf. IWC-83-2:10-15.
Braam, F. and Klapwijk, A. (1981) "Effect of Copper on Nitrification in
Activated Sludge." Water Res. 15:1093-1098.
Bracewell, L. W.[ Jenkins, D. and Cameron, W. (1980) "Treatment of Phenol-
Formaldehyde Resin Wastewater Using Rotating Biological Contactors." Proc.
First N?.t'l. Symposium on RBC Tech. Univ. of Pittsburgh. 733-758.
Broecker, B. and Zahn, R. (1977) "The Performance of Activated Sludge Plants
Compared with the Results of Various Bacterial Toxicity Tests - A Study with
3,5-Dichlorophenol." Water Res. 11:165-172.
Brown, J. A. and Weintraub. M. (1982) "Biooxidation of Paint Process
Wastewater." Journal WPCF. 54:1127-1130.
Butler, L. and Nandan, S. (1981) "Destructive Oxidation of Phenols and Sulfides
using Hydrogen Peroxide." Water 1980: AIChE Symposium Series. 77:108-111.
Button, M. P. and Gaudy, A. F., Jr. (1982) "A Process for Removal of Heavy
Metals from Secondary Sludge." Proc. 36th Ind. Waste Conf. Ann Arbor
Publishing, Ann Arbor, Michigan.0 509-518.
Cain, C. B., Russell, L. L., and Keramida, V. (1983) "Development of Reasonable
Limitations on Discharge of Industrial Pollutants to Municipal Sewers.0 Proc.c
56th Annual Conf., WPCF.
Capestany, G. J., McDaniels, J. and Opgrande, J. L. (1977) "The Influence of
Sulfate on Biological Treatment of Phenolbenzaldehyde Wastes." Journal WPCF.
49:256-261.
Casey, J. D. and Wu, Y.'C. (1978) "Removal of Copper and Cadmium by
Metabolically Controlled Activated Sludge." Proc. 32nd Ind. Waste Conf. Ann
Arbor Publishing, Ann Arbor, Michigan. 141-152.
Caw ley, W. A. Jr. (1981) "Comparison of Bacterial Luminescence Bioussay and
Fish Bioassay for Complex Wastewater.0 M.S. Thesis, University of Cincinnati,
Cincinnati, Ohio. 75 pp.
Cenci, G. and Morozzi, G. (1977) "Evaluation of the Toxic Effect of Cd^+ and
Cd(CN)4^~ Ions on the Growth of Mixed Microbial Population of Activated
Sludges.? The Science of Total Environ. 7:131-143.^
104

-------
Chanda, M., O'Driscoll, X. F. and Rampel, G. L. (1983) "Cyanide Detoxification
by Selective Ion Exchange with Protonated Poly (4-Vinyl Pyridine)." J. Chem.
Tech. Biotechnol. 33A:97-108.
Chang, A. C>, Page, A. L. and Bingham, F. T. (1981) "Re-utilization of Municipal
Wastewater Sludges - Metals and Nitrate." Journal WPCF. 53:237-245.
Chang, S. Y., Huang, J. C., Liu, Y.C. (1985) "Effects of Cd and Cu on a Biofilm
Treatment System." Proc. 39th Ind. Waste Conf. Butterworth Pub., Boston,
Massachusetts. 305-313.
Chavalitnitikul, C. and Brunker, R.L. (1981) "The Removal of Heavy Metals from
Sewage Influent Waters by Foam Flotation." Proc. 13th Mid-Atlantic Ind. Waste
Conf. Ann Arbor Publishing, Ann Arbor, Michigan. 72-86.
Chen, Y.S.E., Peluso, R.A. and Mureebe, A.K. (1984) "Mercury Waste Treatment"
Proc. Ind. Wastes Symposia, 57th Annual WPCF Conf. 242-256.
Chesler, P. G. and Eskelund, G. R. (1980) "RBC for Munitions Wastewater
Treatment." Proc. First Nat'I. Symposium on RBC Tech. Univ. of Pittsburgh.
711-723.
Choate, W. T., Houldsworth, D. and Butler, G. A. (1983) "Membrane-Enhanced
Anaerobic Digesters." Proc. 37th Ind. Waste Conf. Ann Arbor Publishing, Ann
Arbor, Michigan. 661-666.
Chou, W. L., Speece, R. E., Siddiqi, R. H. and McKeon, K. (1978) "The Effect of
Petrochemical Structure on Methane Fermentation Toxicity." Prog. Water Tech.
10:545-558.
Chow, S. T. and Ng, T. L. (1983) "The Biodegradation of N-Methyl-2-Pyrrolidone
in Water by Sewage Bacteria." Technical Note. Water Res. 17:117 — 118.
Christensen, E. R. and Delwiche, J. T. (1982) "Remova )f Heavy Metals from
Electroplating Rinsewaters by Precipitation, Flocculation and Ultrafiltration."
Water Res. 16:729-737.
Clevenger, T. E., Hemphill, D. D., Roberts, K. and Mullins, W. A. (1983)
"Chemical Composition and Possible Mutagenicity of Municipal Sludges."
Journal WPCF. 55:1470-1475.
Coker, E. G. and Matthews, P. J. (1983) "Metals in Sewage Sludge and Their
Potential Effects in Agriculture." Wat. Sci. Tech. 15:209-225.
Cook, K.'A. (1979) "Degradation of the Non-Ionic Surfactant Dobanol 45-7 By
Activated Sludge." Water Res. 13:259-266.
Cornwell, D. A. and Westerhoff, G. F. (1980) "Extract Heavy Metals Via Liquid
Ion-Exchange." Water and Wastes Engr. 17:36-42.
105

-------
Coulter, R. R. (1984) "Pilot Plant Study of Landfill Leachate Treatability by
Rotating Biological Contactors." Proc. Znd Int'l Conf. on Fixed-Film Biological
Processes. Univ. of Pittsburgh. 777-813.
Cox, D. P. (1978) "The Biodegradation of Polyethylene Glycols." Adv. Appl.
Microbiol. 23:173-194.
Culp, Wesner, Culp (1978) "Field Manual for Performance Evaluation and
Troubleshooting at Municipal Wastewater Treatment Facilities." EPA-430-9-78-
001. U.S. EPA, Washington, DC. 387 pp.
Cummins, M. D. (1981) "Effect of Sanitary Landfill Leachate on the Activated
Sludge Process." EPA-600/9-81-002a. U.S. EPA, Cincinnati, Ohio. 170-178.
Dagon, T. J. (1973) "Biological Treatment of Photo Procsssing Effluents."
Journal WPCF. 45:2123-2135.
Dechev, G. B. and Matveeva, E. G. (1977) "Study of Oxygen Uptake Variations of
Activated Sludge Depending on Phenol Concentration." Biologie Biophysique.
30:595-598.
DeLuca, S.J., Chao, A.C. and Smallwood, C. Jr. (1983) "Removal of Organic
Priority Pollutants by Oxidation-Coagulation." Journal Environ. Engr. Div.,
ASCE. 109:36-46.
DeWalle, F. B., Kalinan, D. A., Dills, R., Norman, D., Chian, E. S. K., Giabbai,
M. and Ghosal, M. (1982) "Presence fo Phenolic Compounds in Sewage, Effluent
and Sludge from Municipal Sewage Treatment Plants." Water Science Tech.
14:143-150.
DiGeronimo, M. J., Nikaido, M. and Alexander, M. (1979) "Utilization of
Chlorobenzoates by Microbial Populations in Sewage." Appl. and Environ.
Microbiol. 37:619-625.
Dohanyos, M., Madera, V. and Sedlacek, M. (1978) "Removal of Organic Dyes by
Activated Sludge." Prog. Water Tech. 10:559-575.
Dunn, G. F., Jr.'and Hutton, D. G. (1983) "The Combined Powdered Activated
Carbon-Activated Sludge (PACT) Process for Toxics Control." Water Resources
Symposium No. 10. Univ. of Texas, Austin, Texas. 53-76.
E. C. Jordan Co. (1982) "Fate of Priority Pollutants in Publicly Owned Treatment
Works: 30 Day Study." EPA-440/1-82/302. U.S. EPA, Washington, DC. 263 pp.f
E. C. Jordan Co. (1984) "Combined Sewer Overflow Toxic Pollutant Study."
EPA-440/1 -84-304. U.S. EPA, Washington, DC. 212 pp.
Edgehill, R. U. and Finn, R. K. (1983) "Activated Sludge Treatment of Synthetic
Wastewater Containing Pentachlorophenol." Biotech and Bioengr. 25:2165-2176.
Eis, B. J., Ferguson, J. F. and Benjamin, M. M. (1983) "The Fate and Effect of
Bisulfate in Anaerobic Treatment." Journal WPCF. 55:1355-1365.
106

-------
El-Dib, M. A. and Badawy, M. I. (1979) "Adsorption of Soluble Aromatic Hydro-
carbons on Granular Activated Carbon." Water Res. 13:255-258.
Elliott, W. R., Riding, J. T. and Sherrard, J. H. (1978) "Maximizing Phosphorus
Removal in Activated Sludge." Wat. & Sew. Works. March, 1978:88-92.
Environmental Resources Training Center, Southern Illinois University (1979) "A
Course on Troubleshooting O&M Problems in Wastewater Treatment Facilities."
U.S. EPA, Cincinnati, Ohio.
Farmwald, J. A. and MacNaughton, M. G. (1981) "Effects of Hydrazine on the
Activated Sludge Process" Journal WPCF. 53:565-575.
Fenger, B. H., Mandrup, M., Rohde, G. and Sorensen, J. C. K. (1979)
"Degradation of a Cationic Surfactant in Activated Sludge Pilot Plaints." Water
Res. 7:1195-1208.
Ferguson, J. F., Keay, G. F. P., Merrill, M. S. and Benedict, A. H. (1979)
"Powdered Activated Carbon in Contact Stabilization Activated Sludge."
Journal WPCF. 51:2314-2323.
Fox, C. R. (1979) "Removing Toxic Organics from Wastewater." Chem Engr.
Prog. 75:70-77.
Fox, L. L. and Merrick, N. J. (1983) "Controlling Residual Polychlorinated
Biphenyls in Wastewater Treatment Through Conventional Means." Proc. 37th
Industrial Waste Conf. Ann Arbor Science, Ann Arbor, Michigan. 413-423.
Fricke, C., Clarkson, C., Lomnitz, E. and O'Farrell, T. (1985) "Comparing
Priority Pollutants in Municipal Sludges." Biocycle. Jan./Feb. 1985:35-37.
Fry, F. F., Smith, T. G. and Sherrard, J. H. (1982) "Start-up and Shock Loading
Characteristics of a Rotating E'.alogical Contactor Package Plant." Proc. First
Int'l Conf. on Fixed-Film Biological Processes. Univ. of Pittsburgh. 542-568.
Furukawa, K., Tonomura, K. and Kamibayashi, A. (1978) "Effect of Chlorine
Substitution on the Biodegradability of Polychlorinated Biphenyls." Appl and
Environ. Microbiol. 35:223-227.
Gaffney, P.E. (1976) "Carpet and Rug Industry Case Study I: Water and
Wastewater Treatment Plant Operation." Journal WPCF. 48:2590-2598.
Ganczarczyk, J. J. (1979) "Second-Stage Activated Sludge Treatment of Coke-
Plant Effluents." Water Res. 13:337-342.
Gaudy, A. F., Jr., Gaudy, E. T., Feng, Y. J. and Brueggemann, G. (1982 a)
"Treatment of Cyanide Waste by the Extended Aeration Process." Journal
WPCF. 54:153-164.
Gaudy, A. F. Jr., Kincannon, D. F. and Manickam, T.S. (1982 b) "Treatment
Compatibility of Municipal Waste and Biologically Hazardous Industrial
Compounds." EPA-600/2-82-075a. U.S. EPA, Ada, Oklahoma. 203 pp.
107

-------
Geating, J. (1981) "Literature Study of the Biodegradability of Chemicals in
Water (Vols. 1 and 2)" U.S. EPA, Cincinnati, Ohio. 241 pp.
George, T. K. and Gaudy, A. F., Jr. (1973a) "Transient Reponse of Continuously
Cultured Heterogeneous Populations to Changes in Temperatures." Appl.
Microbiol. 26:796-803.
George, T. K. and Gaudy, A. F., Jr. (1973b) "Response of Completely Mixed
Systems to pH Shock." Biotech & Bioengr. 15:933-949.
Gerardi, M. H. (1981) "Sludge Settling Hampered by Industrial Discharge." Public
Works. June, 1981:95-97.
Gerber, V. Y., Gorobets, L. D. and Ioakimis, E. G. (1979) "Effects of Urea and
Dichloromethane on Biochemical Treatment of Refinery Wastewater" in
Chemistry and Technology of Fuels and Oils. Plenum Publishing. 269-272.
Gerike, P., Fischer, W. K. and Jasiak, W. (1978) "Surfactant Quaternary
Ammonium Salts in Aerobic Sewage Digestion." Water Res. 12:1117-1122.
Gledhill, W. E. (1975) "Biodegradation of 3,4,4' - Trichlorocarbanilide (TCC) in
Sewage and Activated Sludge." Water Res. 9:649-654.
Gray, A. C. Jr., Paul, P. E. and Roberts, H. D. (1979) "Evaluation of Operation
and Maintenance Factors Limiting Biological Wastewater Treatment Plant
Performance." EPA-600/2-79-078. U.S. EPA, Cincinnati, Ohio. 149 pp.
Greenfield, J. H. and Neufeld, R. D. (1982) "Quantification of the Influence of
Steel Industry Trace Organic Substances on Biological Nitrification." Proc. 36th
Ind. Waste Conf. Ann Arbor Publishing, Ann Arbor, Michigan. 772-783.
Gutierrez, A. G., Mclntyre, A. E., Perry, R. and Lester, J. N. (1984) "Behaviour
of Persistent Organochlorine Micropollutants During Primary Sedimentation of
Wastewater." The Science of the Total Envir. 39:27-47.
Hahn, W. H., Barnhart, E. L. and Meighan, R. B. (1977) "The Biodegradability of
Synthetic Size Material Used in Textile Processing." Proc. 30th Ind. Waste Conf.
Ann Arbor Publishing, Ann Arbor, Michigan. 530-539.
Haines, J. R. and Alexander M. (1975) "Microbial Degradation of Polyethylene
Glycols." Appl.?MicrobioI. 29:621-625.
Hammer, M. J. (1983) "Rotating Biological Contactors Treating Combined
Domestic and Cheese-Processing Wastewaters." Proc. 37th Ind. Waste Conf.
Ann Arbor Science, Ann Arbor, Michigan. 29-38.
Hamza, A. A., El-Sharkawi, F. M. and Younis, M. A. (1982) "Biofiltration of
Tannery Wastewater." Proc. First Intl. Conf. on Fixed-Film Biological
Processes. Univ. of Pittsburgh. 1093-1112.
108

-------
Hannah, S. A., Austern, B. M., Eralp, A. E. and Wis
-------
Hrubec, J., van Kreijl, C. F., Morra, C. F. H. and Slooff, W. (1983) "Treatment of
Municipal Wastewater by Reverse Osmosis ard Activated-Carbon-Removal of
Organic Micropollutants and Reduction of Toxicity." The Science of the Total
Environ. 27:71-88.
Huang, C. P. and Wirth, P. K. (1981) "Treatability of Cadmium (II) Plating
Wastewater by Alummosilicate Adsorption." Proc. 13th Mid-Atlantic Ind.
Wastes Conf. Ann Arbor Publishing, Ann Arbor, Michigan. 87-94.
Huang, J. Y. C. and Skeikhdeslami, B. (1983) 'Metal Inhibition on Nitrification."
Proc. 37th Ind. Wast> Conf. Ann Arbor Publishing, Ann Arbor, Michigan. 85-93.
Hung, Y. T., Fossum, G. 0., Paulson, L. E. and V/iilson, W. G. (1981) "Assessment
of Activated Sludge Process in Treating Solvent-Extracted Coal Gasification
Wastewaters." Proc. 13th Mid-Atlantic Ind. Waste Conf. Ann 'rbor Publishing,
Ann Arbor, Michigan. ZZ8-P38.
Hutton, D. G. and Temple, S. (!'? .'9) "Priority Po'lutant Removal: Comparison of
Dupont PACT Process and \ctivated Sludge." Chemical and Petrochemical
Waste Treatment Session. Proc. Ind. Waste Symposia, 52nd WPCF Conf. 1-19.
Iannone, J., Pai, M., and Papamichael, F. (1984) "Organic Priority Pollutants in
New York City Wastewater: Their Sources and Impacts." Proc. Ind. Wastes
Symposia, 57th Annual Conf., WPCF. 392-405.
Imai, H., Endoh, K., Kobayashi, C. (1979) "Activated Sludge During Acclimation
to Saline Water." J. Ferment. Technoi. 57:454-459.
Ishikawa, T., Ose, Y. and bato, T. (1979) "Removal jf Organic Acids by Activated
Sludges." Water Res. 13:681—685.
Ito, K. and Matsuo, T. (1980) "The Effect of Organic Loading on Nitrification in
RBC Wastewater Treatment Processes." Proc. First Nat'l Symposium or. RBC
Tech. Univ. of Pittsburgh. 1165-1175.
Janeczek, J. Jr. and Lamb, J. C. HI (1983) "Treatability of a Coal Gasification
Wastewater Using the Powdered Activated Carbon/Activated Sludge Process."
Proc. 37th Ind. Waste Conf. Ann Arbor Publishing, Ann Arbor, Michigan.
497-505.
Jank, B. E., Guo, H. M. and Cairns, V. W. (1974) "Activated Sludge Treatment of
Airport Wastewater Containing Aircraft De-Icin£ Fluids." Water Res.
8:875-880.
Jeffus, H. M. (1981) "Problems with Metals in the Residue from Combined
Municipal/Industrial Waste Treatment " Proc. Ctnf. on Combined Mun./Ind.
Wastewater Treat. EPA-600/9-81-021. U.S. EPA, Ada, Oklahoma. 544-550.
Jenke, D. R., Pagenkopf, G. K. and Diebold, F. E. (1983) "Chemical Changes in
Concentrated, Acidic, Metal-Bearing Wastewaters When Treated with Lime."
Environ. Sci. Technoi. 17:217-223.
110

-------
Jenkins, R. L., Scheybeler, B. J., Smith, M. L., Baird, R., Lo, M. and Haug,
R. T. (1981) "Metals Removal and Recovery from Municipal Sludge." Journal
WPCF. 53:25-32.
Joel, A. R. arid Grady, C. P. L., Jr. (1977) "Inhibition of Nitrification - Effects of
Aniline After Biodegradation." Journal WPCF. 49:778-788.
Johnson, L. D. and Young, J. C. (1983) "Inhibition of Anaerobic Digestion by
Organic Priority Pollutants." Journal WPCF. 55:1441-1449.
Jones, D. D., Speake, J. L., White, J. and Gauthier, J. J. (1984) "Biological
Treatment of High-Strength Coke-Plant Wastewater." Proc. 38th Ind. Waste
Conf. Butterworth Pub., Boston, MA. 561-570.
JRB Associates (1981a) "304(g) Guidance Document: Revised Pretreatment
Guidelines (Vols. I and II)." Internal Report.. U.S. EPA, Cincinnati, Ohio.
JRB Associates (1981b) "Assessment of the Impacts of Industrial Discharges on
Publicly Owned Treatment Works." Report submitted to the Office of Water
Enforcement, U.S. EPA, Washington, D.C.
JRB Associates (1982-1984) "POTW Inspection Reports(s)." A Series of Internal
Reports (Contract No. 68-01-6514). U.S. EPA, Washington, DC.
Kang, S. J.. Bulkkey, J. W. and Spangler, J. L. (1981) "Fate of Heavy Metals and
Tolerance Limits in POTW." Proc. 1981 Environ. Engr. Div. Conf., ASCE.
400-407.
Kang, S. J. and Borchardt, J. A. (1982) "Inhibition of Nitrification by Chromium
in a Biodisc System." Proc. First Int'l. Conf. on Fixed-Film Biological Processes.
Univ. of Pittsburgh. 990-1006.
Kao, J. F., Hsieh, L. P., Cheng, S. S. and Huang, C. P. (1982) "Effect of EDTA on
Cadmium in Activated Sludge Systems." Journal WPCF. 54:1118-1126.
Kao, J. F. and Kang, S. F. (1984) "A Study of Soda Pulp Wastewater Treatment
by Submerged Bio filter." Proc 2nd Int'l. Conf. on Fixed-Film Biological
Processes. Univ. of Pittsburgh. 1681-1692.
Kashiwaya, M. and Yoshimoto, K. (1980) "Tannery Wastewater Treatment by the
Oxygen Activated Sludge Process." Journal WPCF. 52:999-1007.
Kennedy, K. J. and vandenBerg, L. (1982) "Effects of Temperature and Over-
loading on the Performance of Anaerobic Fixed-Film Reactors/' Proc. 36th Lid.
Waste Conf. Ann Arbor Publishing, Ann Arbor, Michigan. 678-685.
Khan, K. A., Suidan, M. T. and Cross, W. H. (1981) "Anaerobic Activated Carbon
Filter for the Treatment of Phenol-Bearing Wastewater." Journal WPCF.
53:1519-1532.
Ill

-------
Khararjian, H. A., Smith, J. W. and Ledoux, G. A. (1979) "Treatment oi Phenolic
Wastewater." Proc. 11th Mid. Atlantic Ind. Waste Conf. Ann Arbor Publishing,-
Ann Arbor, Michigan, 189-195.
Kim, J. W. and Armstrong, N. A. (1981) "A Comprehensive Study on the
Biological Treatabilities of Phenol and Methanol-II: The Effects of Tempera-
ture, pH, Salinity and Nutrients." Water Res. 15:1233-1247.
Kim, B. M. and Amodeo, P. A. (1983) "Calcium Sulfide Process for Treatment of
Metal-Containing Wastes." Environ. Prog. 2:175-180.
Kincannon, D. F., Gaudy, A. F. Jr., and Manickam, T.S. (1981) "Treatment of
Municipal Wastewaters Containing Biologically Hazardous Industrial Compounds
by Conventional Activated Sludge and Extended Aeration." Proc. Conf. on
Combined Mun./Ind. Wastewater Treat. EPA-600/9-81-021. U.S. EPA, Ada,
Oklahoma. 60-78.
Kincannon, D. F., Esfandi, A. and Manickam, T. S. (1982) "Compatibility of
Semiconductor Industry Wastewater with Municipal Activated Sludge Systems."
Proc. 36th Ind. Waste Conf. Ann Arbor Publishing, Ann Arbor, Michigan.
533-539.
Kincannon, D. F., Stover, E. L., Nichols, V. ai»u Medley, D. (1983) "Removal
Mechanisms for Toxic Priority Pollutants." Journal WPCF. 55:157-163.
Klecka, G. M. (1982) "Fate and Effects of Methylene Chloride in Activated
Sludge." Appl and Environ. Microbiol. 44:701-707.
Klein, S. A. (1974) "NTA Removal in Septic Tank and Oxidation Pond Systems."
Journal WPCF. 46:78-88.
Klemetson, S.L. and Scharbow, M.D. (1979) "Filtration of Phenolic Compounds in
Coal Gasification Wastewater." Journal WPCF. 51:2752-2763.
Kobylinski, E. A. and Bell, B. A. (1983) "Light Metal Cation Inhibition in
Anaerobic Digestion." Proc. 1983 Nat'l. Conf. on Env. Engr., ASCE. 399-402.
Koch, C. M., Stroka, J. G., Perna, R. K. and Forester, R. E. (1982) "Impact of
Pretreatment on Sludge Content of Heavy Metals." Journal WPCF. 54:339-343.
Kunz, R. G., Giannelli, J. F. and Stensel, H.D. (1976) "Vanadium Removal From
Industrial Wastewaters." Journal WPCF. 48:762-770.
Landon-Arnold, S. and Chan, D. B. (1982) "Application of Rotating Biological
Contactor (RBC) Process for Treatment of Wastewater Containing a Firefighting
Agent (AFFF). Proc. First Int'l. Conf. on Fixed-Film Biological Processes. Univ.
of Pittsburgh. 927-943.
Landon-Arnold, S. and Chan, D. B. (1984) "Microbial Treatability of Aqueous
Film Forming (AFFF) with a Rotating Biological Contactor." Proc. 2nd Int'l.
Conf. on Fixed-Film Biological Processes. 1296-1314.
112

-------
Lau, C. M. (1978) "Staging Aeration for High-Efficiency Treatment of Aromatic
Acids Plant Wastewater." Proc. 32nd Ind. Waste Conf. Ann Arbor Publishing,
Ann Arbor, Michigan. 63-74.
Lawson, C. T. and Siegrist, S. A. (1981) "Removal Mechanisms for Selected
Priority Pollutants in Activated Sludge Systems." Proc. of the 1981 National
Conf. on Environ. Engr., ASCE. 356-363.
Leipzig, N. A. and Hockenbury, M. R. (1980) "Powdered Activated
Carbon/Activated Sludge Treatment of Chemical Production Wastewaters."
Proc. 34th Ind. Waste conf. Ann Arbor Publishing, Ann Arbor, Michigan.
195-205.
Lense, F. T., Mileski, S. E. and Ellis, C. W. (1978) "Effects of Liquid Detergent
Plant Effluent on the Rotating Biological Contactor." EPA-600/2-78-129. U.S.
EPA, Cinncinnati, Ohio. 57 pp.
Lester, J. N. (1983) "Significance and Behviour of Heavy Metals in Wastewater
Treatment Processes: I. Sewage Treatment and Effluent Discharge." The Science
of the Total Environment. 30:1-44.
Levins, P., Adams, J., Brenner, P., Coons, S., Harris, G., Jones, C., Thrun, K. and
Wechsler, A. (1981) "Sources of Toxic Pollutants Found in Influents to Sewage
Treatment Plants: Vol. VI. Integrated Interpretation." EPA-440/4-81-008.
U.S. EPA, Washington, DC. 125 pp.
Li, C. T., Chen, H. T. and Wu, Y. C. (1982) "Treatment of Starch Industrial Waste
by RBCs." Proc. First Int'l. Conf. on Fixed-Film Biological Processes. Univ. of
Pittsburgh. 960-989.
Li, C. T. Hwu, N. T. and Whang, J. S. (1984) "Treatment of Slaughterhouse
Wastewater by Biofiltration Tower." Proc. 2nd Intl. Conf. on Fixed-Film
Biological Processes. Univ. of Pittsburgh. 1336-1359-
Liu, D. (1980) "Enhancement of PCBs Biodegradation by Sodium Ligninsulfonate."
Water Res. 14:1467-1475.
Lordi, D. T., Lue-Hing, C. and Whitebloom, S. W. (1980) "Cyanide Problems in
Muicipal Wastewater Treatment Plants." Journal WPCF. 52:597-609.
Lowry, J. D., and Chwirka, J. (1983) "Papermill Wastewater Treatment." Envir.
Progress. 2:158-166.
Luthy, R. G., Sekel, D. J. and Tallon, J. T. (1980) "Biological Treatment of
Synthetic Fuel Wastewater." J. Environ. Engr. Div., ASCE. 106:609-629.
Luthy, R. G. and Jones, L. D. (1980) "Biological Oxidation of Coke Plant
Effluent." J. Environ. Engr. Div., ASCE. 106:847-851.
Luthy, R. G. (1981) "Treatment of Coal Coking and Coal Gasification Waste-
waters." Journal WPCF. 53:325-339.
113

-------
Lytle, P. E. (1984) "Treatment of Photofinishing Effluents Using Rotating
Biological Contactors (RBCs)." Journal of Imaging Tech. 10:221-226.
Manickan, T. S. and Gaudy, A. F., Jr. (1983) "Comparison of Activated Sludge
Response to Quantitative, Hydraulic and Combined Shock for the Same Increases
in Mass Loading." Proc. 37th Ind. Waste Conf. Ann Arbor Publishing, Ann Arbor,
Michigan. 601-618.
Matsui, S., Murakami, T., Sasaki, T., Hirose, Y. and Iguma, Y. (1975) "Activated
Sludge Degradability of Organic Substances in the Wastewater of the Kashima
Petroleum and Petrochemical Industrial Complex in Japan." Prog. Water Tech.
7:645-659.
Matsumoto, J. and Noike, T. (1978) "Effects of Heavy Metals on Anaerobic
Sludge Digestion: I. Studies by the Batch Digestion Experiment." Tech. Reports.
Tohoka Univ. 43:173-189.
McCarty, P.L. and Reinhard, M. (1980) "Trace Organics Removal by Advanced
Wastewater Treatment." Journal WPCF. 52:1907-1922.
Mclntyre, A. E., Lester, J. N. and Perry, R. (1981a) "The Influence of Chemical
Conditioning and Dewatering on the Distribution of Polychlorinated Biphenyls
and Organochlorine Insecticides in Sewage Sludges." Envir. Pollut. (Series B).
2:309-320.
Mclntyre, A. E., Perry, R. and Lester, J. N. (1981b) "The Behaviour of
Polychlorinated Biphenyls and Organochlorine Insecticides in Primary Mechanical
Wastewater Treatment." Envir. Poll. (Series B). 2:223-233.
Mclntyre, G., Rodriguez, J.J., Thackston, E.L. and Wilson, D.J. (1983)
"Inexpensive Heavy Metal Removal by Foam Flotation." Journal WPCF.
55:1144-1149.
McKinney, R. E. (1977) "Performance Evaluation of an Existing Lagoon System
at Eudora, Kansas." EPA-600/2-77-167. U.S. EPA, Cinci- ua Ohio. 240 pp.
McManus, A. M. C., Werthman, P. H. and Westendorf, J. R. (1985) "Granular
Activated Carbon Removal of Priority Pollutants in a Combined
Municipal/Industrial Wastewater." Proc. 39th Ind. Waste Conf. Butterworth
Pub., Boston, Massachusetts. 719-735.
Medley, D.R. and Stover, E.L. (1983) "Effects of Ozone on the Biodegradability
of Biorefractory Pollutants." Journal WPCF. 55:489-494.
Medwith, B. W. and Lefelhocz, J. F. (1982) "Single-Stage Biological Treatment of
Coke-Plant Wastewaters with a Hybrid Suspended Growth-Fixed Film Reactor."
Proc. 36th Ind. Waste Conf. Ann Arbor Publishing, Ann Arbor, Michigan. 68-76.
Miller, S., Abeliovich, A. and Belfort, G. (1977) "Effects of High Organic Loading
on Mixed Photosynthetic Wastewater Treatment." Journal WPCF. 49:436-440.
114

-------
Mirzadeh, A., Maeda, Y. and Fazeli, A. (1977) "Effects of Sodum Bentonite and
Ferric Chloride on Activated Sludge Treatment of Wastewater." J. Ferment.
Technol. 55:258-264.
Monnig, E. C., Little, L. W. and Zweidinger, R. (1981) "Investigations on the
Suitability of Various Pesticide Manufacturing Wastewater for Discharge to
Municipal Waste Treatment Facilities." Proc. Conf. on Combined Mun./Ind.
Wastewater Treat. EPA-600/9-81-021. U.S. EPA, Ada, Oklahoma. 259-271.
Moore, L. and Barth, E. F. (1976) "Degradation of NTA Acid During Anaerobic
Digestion." Journal WPCF. 48:2406-2409.
Moos, L. P., Kirsch, E. J., Wukasch, R. F. and Grady, C. P. L., Jr. (1983)
"Pentachlorophenol Biodegradation - I:Aerobic." Water Res. 17:1575-1584.
Morimoto, M. K. and Nambu, S. (1976) "The Response of Activated Sludge to a
Polychlorinated Biphenyl (KC-500)." Water Res. 10:157-163.
Morozzi, G. and Cenci, G. (1978) "Comparison of the Toxicity of Some Metals
and Their Tetracyanide Complexes on the Respiration of Non Acclimated
Activated Sludges." Zbl. Bakt. Hyg. 167:478-488.
Mosey, F. E. and Hughes, D. A. (1975) "The Toxicity of Heavy Metal Ions to
Anaerobic Digestion." Water Pollution Control 1975. Water Research Center,
Stevenage, Herts. 18-39.
Muttamora, S. and Islam, S. (1983) "Effect of Chromium on Activated Sludge
Process Performance." Proc. 15th Mid-Atlantic Ind. Waste Conf. Butterworth
Pub., Boston, MA. 144-154.
Nail, A.E. (1980) "Economically Remove Toxics." Water and Wastes Engr. Feb.
1980:43, 48, 52-53.
Nay, M. W. Jr., Randall, C. W. and King, P. H. (1974) "Biological Treatability of
Trinitrotoluene Manufacturing Wastewater." Journal WPCF. 46:485-497.
Naylor, L. M. and Loehr, R. C. (1982a) "Priority Pollutants in Municipal Sewage
Sludge." Biocycle. July/Aug. 1982:18-22.
Naylor, L. M. and Loehr. R. C. (1982b) "Priority Pollutants in Municipal Sewage
Sludge - Part II." Biocycle. Nov./Dec. 1982:37-42.
Neel, J. K., Vennes, J. W., Fossum, G. O. and Orthmeyer, F. B. (1976) "Anaerobic
and Aerobic Treatment of Combined Potato Processing and Municipal Wastes."
EPA-600/2-76-236. U.S. EPA, Cincinnati, Ohio. 142 pp.
Neiheisel, T. W., Horning, W. B., Petrasek, A. C., Asberry, V. R., Jones, D. A.,
Marcum, R. L. and Hall, C. T. (1982) "Effects on Toxicity of Volatile Priority
Pollutants Added to a Conventional Wastewater Treatment System." Internal
Report. U.S. EPA, Cncinnati, Ohio. 9 pp.
115

-------
Nelson, P. O., Chung, A. K. and Hudson, M. C. (1931) "Factors Affecting the
Fate of Heavy Metals in the Activated Sludge Process." Journal WPCF.
53:1323-1333.
Neufeld, R. D. (1976) "Heavy Metals-Induced Deflocculation of Activated
Sludge." Journal WPCF. 48:1940-1947.
Neufeld, R. D. and Valiknae, T. (1979) "Inhibition of Phenol Biodegradation by
Thiocyanate." Journal WPCF. 51:2283-2291.
Neufeld, R. D., Hill, A. J. and Adekoya, D. O. (1980a) "Phenol and Free Ammonia
Inhibition to Nitrosomonas Activity." Water Res. 14:1695-1703.
Neufeld, R. D., Mack, J. D. and Strakey, J. P. (1980b) "Anaerobic Phenol Bio-
kinetics." Journal WPCF. 52:2367-2377.
Neufeld, R. D., Mattson, L. and Lubon, P. (1981) "Thiocyanate Bio-Oxidation
Kinetics." J. Environ. Engr. Div., ASCE. 107:1035-1049.
Newbry, B. W., Macaulay, M. N., Musterman, J. L. and Davison, W. E., Jr. (1982)
"Troubleshooting an Existing RBC Facility." Proc. First Int'l Conf. on Fixed-
Film Biological Processes. Univ. of Pittsburgh. 1710-1730.
Nielson, J. S. and Hrudey, S. E. (1983) "Metal Loadings and Removal at a
Municipal Activated Sludge Plant." Y/ater Res. 17:1041-1052.
Niku, S., Schroeder, E.D., Tchobanoglous, G. and Samaniego, F. J. (1981)
"Performance of Activated Sludge Processes: Reliability, Stability and Vari-
ability." Project Summary. EPA-600/S2-81-227. U.S. EPA, Cincinnati, Ohio.
11 pp.
Novak, J. T. and Kraus, D. L. (1973) "Degradation of Long Chain Fatty Acids by
Activated Sludge." Water Res. 7:843-851.
Nutt, S.G. and Zaidi, S.A (1984) "Treatment of Cyanide-Containing Wastewaters
by the Copper-Catalyzed S02/Air Oxidation Process." Proc. 38th Ind. Wastes
Conf. Ann Arbor Publishing, Ann Arbor, Michigan. 357-368.
Nyer, E. K. and Bourgeois, H. J., Jr. (1981) "Operational Troubleshooting in
Industrial Biological Treatment Systems." Proc. 35th Ind. Waste Conf. Ann
Arbor Publishing, Ann Arbor, Michigan. 849-854.
Olthof, M. and Oleszkiewicz, J. (1983) "Benzol Plant Wastewater Treatment in a
Packed-Bed Reactor." Proc. 37th Ind. Waste Conf. Ann Arbor Publishing, Ann
Arbor, Michigan. 519-525,
Ongerth, J. E. and DeWalle, F. B. (1980) "Pretreatment of Industrial Discharges
To Publicly Owned Treatment Works." Journal WPCF. 52:2246-2256.
Osantowski, R. and Hendriks, R.V. (1982) "Physical/Chemical and Biological
Treatment of Coke-Plant Wastewater." Proc. 36th Ind. Waste Conf. Ann Arbor
Publishing, Ann Arbor, Michigan. 168—176T
116

-------
Otake, T., Tone, S., Kono, K. and Nakao, K. (1979) "Photo-Oxidation of Phenols
with Ozone." J. Chem. Engr. Japan. 12:289-295.
Ouyang, C. F. (1984) "Effect of Influent Conditions on Nutrient Removal in RBC
System." Proc. 2nd Int'l Conf. on Fixed-Film Biological Processes. Univ. of
Pittsburgh. 683-708.
Painter, Ii. A. and King, E. F. (1978) "The Effect of Phosphate and Temperature
on Growth of Activated Sludge and on Biodegradation of Surfactants." Water
Res. 12:909-915.
Pajak, A. P., Martin, E. J., Brinsko, G. A., and Erny, F. J. (1977) "Effect of
Hazardous Material Spills on Biological Treatment Processes." EPA-600/2-
77/239. U.S. EPA, Cincinnati, Ohio. 204 pp.
Panzer, C. C. (1982) "Biological Nitrogen Control - A Comparison of Methods."
J. Am. Leather Chem. Assoc. 77:149-160.
Parkin, G. F. and Speece, R. E. (1982) "Modeling Toxicity in Methane Fermen-
tation Systems." Journal Env. Engr. Div., ASCE. 108:515-531.
Parkin, G. F. and Miller, S. W. (1983) "Response of Methane Fermentation to
Continuous Addition of Selected Industrial Toxicants." Proc. 37th Ind. Waste
Conf. Ann Arbor Publishing, Ann Arbor, Michigan. 729-743.
Parkin, G. F., Speece, R. E., Yang, C. H. J. and Kocher, W. M. (1983) "Response
of Methane Fermentation Systems to Industrial Toxicants." Journal WPCF.
55:44-53.
Patterson, J. W., Kodukula, P. and Aratani, T. (1983) "Removal of Metals in
Combined Treatment Systems." EPA-600/2-83-051. U.S. EPA, Ada, Oklahoma.
274 pp.
Pearson, F., Shiun-Chung, C. and Gautier, M. (1980) "Toxic Inhibition of
Anaerobic Biodegradation." Journal WPCF. 52:472-482.
Pelosi, P. and McCarthy, J. (1982a) "Preventing Fouling of Ion-Exchange Resins
-	I." Chem. Engr. Aug. 9, 1982:75-78.
Pelcsi, P. and McCarthy, J. (1982b) "Preventing Fouling of Ion-Exchange Resins
-	n." Chem. Engr. Sept. 6, 1982:125-128.
Petrasek, A. C. and Kugelman, I. J. (1983) "Metals Removal and Partitioning in
Conventional Wastewater Treatment Plants." Journal WPCF. 55:1183-1190.
Petrasek, A. C., Kugelman, I. J., Austern, B. M., Pressley, T. A., Winslow, i^. A.
and Wise, R. H. (1983) "Fate of Toxic Organic Compounds in Wastewater
Treatment Plants." Journal WPCF. 55:1286-1296.
Petrasek, A. C. (1981a) "Inhibition, Removal and Partitioning Interactions
Between Lead and the Activated Sludge Process." Internal Report. U.S. EPA,
Cincinnati, Ohio 62 pp.
117

-------
Petrasek, A. C. (1981b) "Removal and Partitioning Interactions and the Inhibitory
Effects of Mercury on the Activated Sludge Process." Internal Report. U.S.
EPA, Cincinnati, Ohio. 58 pp.
Petrasek, A. C. (1981c) "Inhibition of the Activated Sludge Process by
Cadmium." Internal Report. U.S. EPA, Cincinnati, Ohio. 39 pp.
Pitkat, C. A. and Berndt, C. L. (1981) "Textile Waste Treatment of a Municipal
PACT Facility." Proc 35th Ind. Waste Conf. Ann Arbor Publishing, Ann Arbor,
Michigan. 178-185.
Pitter, P. (1976) "Determination of Biological Degradability of Organic Sub-
stances." Water Res. 10:231-235.
Porter, J. J. and Snider, E. H. (1976) "Long-Term Biodegradability of Textile
Chemicals." Journal WPCF. 48:2198-2210.
Radick, K. A. (1984) "Start-up Problems at a Dairy Waste Treatment Plane,"
Proc. Ind. Wastes Symposia, 57th Annual WPCF Conf. 63-77.
Raef, S. F., Characklis, W. G., Kessick, M. A. and Ward, C. H. (1977) "Fate of
Cyanide and Related Compounds in Aerobic Microbial Systems - II. Microbial
Degradation." Water Res. 11:485-492.
Reinhold, M. and Mallevialle, M. (1975) "Biodegradation by the Activated Sludge
System of Steam Process Water in the Timber Industry." Water Res. 9:87-93.
Remacle, J. and Hauba, C. (1983) "The Removal of Heavy Metals from Industrial
Effluents in a Biological Fluidized Bed." Envir. Tech. Letters. 4:53-58.
Renn, C. E. (1974) "Biodegradation of NTA Detergents in a Wastewater Treat-
ment System." Journal WPCF. 46:2363-2371.
Rice, R.G. (1981) "Ozone for the Treatment of Hazardous Materials". Water
1980: AIChE Symposium Series. 77:79-93.
Richards, A. D., Fricke, A. M. and Scott, J. E. (1983) "Phenol Degradation in a
Three-Phase, Fluidized-Bed Bioreactor." ORNL/MIT-361. Oak Ridge National
Lab, Oak Ridge, Tennessee. 57 pp.
Ripley, L. E., Kmet, N. M. Boyle, W. C. and Converse, J. C. (1985) "The Effects
of Ammonia Nitrogen on the Anaerobic Digestion of Poultry Manure." Proc.
39th Ind. Waste Conf. Butterworth Pub., Boston, Massachusetts. 73-79.
Rivera, A. L. (1983) "Heavy Metal Removal in a Packed-Bed, Anaerobic Upflow
(ANFLOW) Bioreactor." Journal WPCF. 55:1450-1456.
Robins, J.H. and Green, A.C. (1974) "Development of On-Shore Treatment
System for Sewage from Watercraft Waste Retention System."
EPA 670/2-74-056. U.S. EPA, Cincinnati, Ohio. 114 pp.
118

-------
Rooney, M. C. and Wu, M. H. (1982) "Joint Treatment of Meat-Packing and
Municipal Wastewater by Full-Scale AWT Facilities." Proc. 36th Ind. Waste
Conf. Ann Arbor Publishing, Ann Arbor, Michigan. 301-309.
Rossin, A. C., Sterritt, R. M. and Lester, J. N. (1982) "Removal of Heavy Metals
in Activated Sludge." Water, Air and Soil Poll. 17:185-198.
Rozich, A. F. and Gaudy, A. F., Jr. (1985) "Response of Phenol-Acclimated
Activated Sludge Process to Ouantitive Shock Loading." Journal WPCF.
57:795-804.
Russell, L.L., Cain, C.B. and Jenkins, D.I. (1983) "Impact of Priority Pollutants
on Publicly Owned Treatment Works Processes: A Literature Review." Proc.
37th Ind. Waste Conf. Ann Arbor Publishing, Ann Arbor, Michigan. 871-883.
Rusten, B. and Thorvaldsen, G. (1983) "Treatment of Food Industry Effluents -
Activated Sludge vs. Aerated Submerged Biological Filters." Environ. Letters.
4:441-450.
Saeger, V. W., Kaley, R. G., Hicks, O., Tucker, E. S. and Mieure, J. P. (1976)
"Activated Sludge Degradation of Adipic Acid Esters." Appl. and Environ.
Microbiol. 31:746-749.
Sampayo, F. F. and Hollopeter, D. C. (1979) "The Influence of Industrial Waste on
Nitrification." Proc. 33rd Ind. Waste Conf. Ann Arbor Publishing, Ann Arbor,
Michigan. 142-154.
Schwartz, M. (1984) "Biological Treatment of Formald.ehyde Wastes in a Mixture
of Wastewater From Methanol, Acetylene, Vinyl Acetate and Acetic Acid
Production." Proc. Ind. Wastes Symposia, 57th Annual WPCF Conf. 26-41.
Science Applications International Corp. (1986) "Guidance Manual for the
Development of an Accidental Spill Prevention Program." U.S. EPA, Regional X,
Seattle, Washington.
Selna, M. W. and Schroeder, E. D. (1978) "Response of Activated Sludge
Processes to Organic Transients-Kinetics." Journal WPCF. 50:944-957.
Shaul, G. M., Barnett, M. W. and Dostal, K. A. (1983) "Treatment of Dye and
Pigment Processing Wastewaters by the Activated Sludge Process." Proc. 37th
Ind. Waste Conf. Ann Arbor Publishing, Ann Arbor, Michigan. 677-689.
Silva, S.J. (1981) "EPA Moving to Control Industrial Toxic Pollutants with New
NPDES Permits." Civil Engr. 51:76.
Skrinde, J. R. and Bhagat, S. K. (1982) "Industrial Wastes as Carbon Sources in
Biological Denitrification." Journal WPCF. 54:370-377.
Slonim, Z., Lien, L. T., Eckenfelder, W. W. and Roth, J. A. (1984) "Removal of
4,6-Dinitro-o-Cresol: Pilot-Scale Anaerobic-Aerobic System." Proc. 2nd Int'l
Conf. on Fixed-Film Biological Processes. Univ. of Pittsburgh. 1095-1118.
119

-------
Smith, L. L. (1980) "Evaluation of an Anaerobic Rotating Surface System for
Treatment of a Munition Wastewater Containing Organic and Inorganic
Nitrates." Proc. 34th Ind. Waste Conf. Ann Arbor Publishing, Ann Arbor,
Michigan. 628-634.
Smith, J. W., Khararjian, H. and Harvell, G. (1981) "Performance of Three Types
of Activated Sludge Processes Under Variable Organic and Pesticide Loadings."
Proc. 13th Mid-Atlantic Ind. Waste Conf. Ann Arbor Publishing, Ann Arbor,
Michigan. 250-263.
Smith, L. L. and Greene, W. C. (1982) "Operation of a RBC Facility for the
Treatment of Munition Manufacturing Plaint Wastewater." Proc. First Int'l Conf.
on Fixed-Film Biological Processes. Univ. of Pittsburgh. 944-959.
Smith, J. W. and Moore, L. W. (1984) "Biodetoxification of Hazardous Waste-
waters with Activated Rotating Biological Contactors." Proc. 16th Mid-Atlantic
Ind. Waste Conf. Technomic Publishing, Lancaster, Pennsylvania. 15-28.
Snyder, D.J. HI, ed. (1978) "Digest of the Clean V/ater Act of 1977." Roy F.
Weston, Inc., West Chester, Pennsylvania. 17 pp.
Soderberg, R. W. and Bockrath, R. E. (1985) "Treatability of Diverse Waste
Streams in the PACT Activated Carbon-Biological Process." Proc. 39th Ind.
Waste Conf. Butterworth Pub., Boston, Massachusetts. 121-127.
Speece, R. E., Parkin, G. F. and Gallagher, D. (1983) "Nickel Stimulation of
Anaerobic Digestion." Water Res. 17:677-683.
Stafford, D. A. (1974) "The Effect of Phenols and Heterocyclic Bases on
Nitrification in Activated Sludges." J. Appl. Bact. 37:75-82.
Sterritt, R. M. and Lester, J. N. (1981) "The Influence of Sludge Age on Heavy
Metal Removal in the Activated Sludge Process." Water Res. 15:59-65.
Stover, E. L. and Kincannon, D. F. (1983) "Biological Treatability of Specific
Organic Compounds Found in Chemical Industry Wastewaters." Journal WPCF.
55:97-109.
Stover, E. L., Gonzalez, R. and Gomathinayagem, G. (1984) "Anaerobic Fixed-
Film Biological Treatment Kinetics of Fuel Alcohol Production Wastewaters."
Proc. 2nd Int'l Conf. on Fixed-Film Biological Processes. Univ. of Pittsburgh.
1625-1646.
Stover, E. L. and Rakness, K. L. (1984) "Process Evaluation at Fixed Film
Biological Treatment Plants-Two Case Studies." Proc. 2nd Intl. Conf. on Fixed-
Film Biological Processes. Univ. of Pittsburgh. 814-830.
Strachan, S. D., Nelson, D. W. and Sommers, L. E. (1983) "Sewage Sludge
Components Extractable with Nonaqueous Solvents." J. Environ. Qual.
12:69-74.
120

-------
Stracke, R. J. and Baumann, E. R. (1978) "Biological Treatment of a Toxic
Industrial Waste-Performance of an Activated Sludge and Trickling Filter Pilot
Plant." Proc. 30th Ind. Waste Conf. Ann Arbor Science, Ann Arbor, Michigan.
1131-1160.
Stratta, J. M., Long, D. A. and Doherty, M. C. (1982) "Improvement of Nitrifi-
cation in Rotating Biological Contactors by Means of Alkaline Chemical
Addition." Proc. First Int'l Conf. on Fixed-Film Biological Processes. Univ. of
Pittsburgh. 758-801.
Suidan, M. T., Cross, W. H., Fong, M. and Calvert, J. W. (1981) "Anaerobic
Carbon Filter for Degradation of Phenols." Journal Envir. Engr. Div., ASCE.
107:563-579.
Sujarittanonta, S. and Sherrard, J. H. (1981) "Activated Sludge Nickel Toxicity
Studies." Journal WPCF. 53:1314-1322.
Sukes, G.L., Pordon, R.G. and Gupta, K. (1984) "The Destruction of Cyanide in
Wastewater with Ozone." Proc. Ind. Wastes Symposia, 57th Annual WPCF Conf.
154-170.
Sullivan, D. E. (1983) "Biodegradation of a Cationic Surfactant in Activated
Sludge." Water Res. 17:1145-1151.
Sundstrom, D. W., Klei, H. E., Tsui, T. and Nayar, S. (1979) "Response of
Biological Reactors to the Addition of Powdered Activated Carbon." Water Res.
13:1225-1231.
Surampalli, R. Y., TeKippe, R. J. and Baumann. E. R. (1984) "The Value of
Supplemental Air in Improving RBC Performance." Proc. 2nd Int'.. Conf. on
Fixed-Film Biological Processes. Univ. of Pittsburgh. 944-964.
Sykes, R. M., Rubin, A. J., Roth, S. A. and Chang, M. C. (1979) "Treatability of
a Nonionic Surfactant by Activated Sludge." Journal WPCF. 51:71-77.
Tabak, H. H., Quave, S. A., Mashni, C. I. and Barth, E. F. (1981)
"Biodegradability Studies with Organic Priority Pollutant Compounds." Journal
WPCF. 53:1503-1518.
Thabaraj, G. J., and Gaudy, A. F., Jr. (1969) "Effect of Dissolved Oxygen
Concentration on the Metabolic Response of Completely Mixed Activated
Sludge." Journal WPCF. 41:R322-R335.
Theis, T. L. and Padgett, L. E. (1983) "Factors Affecting the Release of Trace
Metals from Municipal Sludge Ashe*." Journal WPCF. 55:1271-1279-
Tokuz, R. Y. and Eckenfelder, W. W., Jr. (1979) "The Effect of Inorganic Salts on
the Activated Sludge Process Performance." Water Res. 13:99-104.
Tolaney, M. (1977) "Treatment of High Strength Citrus Wastewater with High
Purity Oxygen Activated Sludge Process." Proc. 30th Ind. Wastes Conf. Ann
Arbor Publishing, Ann Arbor, Michigan. 171-183.
121

-------
Troxler, R. W. and Hopkins, K.S. (1982) "Case Histories: Carpet Manufacturing
Wastewater Treatment in Municipal Points." Proc. 36th Ind. Waste Conf. Ann
Arbor Publishing, Ann Arbor, Michigan. 755-765.
Turner, C. D., Wernberg, K., Strain, J. H. and Gallagher, J. R. (1984) "Treatment
of Coal Gasification Wastewater Using Rotating Biological Contactors." Proc.
2nd Int'l Conf. on Fixed-Film Biological Processes. Univ. ,f Pittsburgh.
1257-1276.
U.S. EPA (1977a) "Federal Guidelines: State and Local Pretreatment Programs
(Vols. I, n, and III)." MCD-43, EPA-430/9-76/017. U.S. EPA, Washington, DC.
U.S. EPA (1977b) "Results of Investigations, T. E. Maxson WTP and Significant
Industrial Contributors, Memphis, Tennessee." EPA-904/9-77-005. U.S. EPA,
Athens, Georgia. 246 pp.
U.S. EPA (1981) "Treatability Manual (Vols. I through V)." EPA-600/2-82/001.
U.S. EPA, Washington, D.C.
U.S. EPA (1985) "Pretreatment Implementation Review Task Force: Final Report
to the Administrator." U.S. EPA, Washington, DC. 75 pp.
Vaicum, L. and Eminovici, A. (1974) "The Effect of Trinitro-Phenol and
-Hexachlorocyclohexane on the Biochemical Characteristics of Activated
Sludge." Water Res. 8:1007-1012,
Volesky, B., Samak, Q. and Waller, P. (1977) "The Effect of Metallic and Ionic
Species on the Performance of a Biological Effluent Treatment System." Proc.
12th Canadian Symp. Water Pollution Research (Canada). 191-212.
Vuccta, J., Anderson, J. R., TeKippe, R. J., Calkins, R. J. and Bishop, W. J.
(1979) "Bench-Scale Testing for Residual Waste Treatment." Journal WPCF.
51:2366-2383.
Wagner, F. (1984) "Studies on the Causes and Prevention of Bulking Sludge in
Germany." Water Sci. Tech. 1^:1-14.
Wats- . G. K. and Jones, N. (1^771 "The Liodegradation of Polyethylene Glycols
by Sewage Bacteria." Water Res. 11:95-100.
Watt, J. C. and Cah: , C. J. (1980) "Wastewater Treatability Studies for a
Grassroots Chemical Complex Using Bench Scale Rotating Biologicai
Contactors." Proc. First Nat'l. Symposium on RBC Tc<_h. Univ. of Pittsburgh.
661-690.
Webber, W. G., Kemp, D. W. and Rice, S. E. (1977) "Study of the Effect of Eoron
Toxicity on an Activated Sludge System." Proc. 31st Ind. Waste Conf. Ann Arbor
Publishing, Ann Arbor, Michigan. 743-752.
Webber, M. D., Monteith, H. D. and Corneau, D. G. M. (1983) "Assessment of
Heavy Metals and PCB's at Sludge Application Sites." Journal WPCF.
55:187-195.
122

-------
Weber, A. S. and Sherrand, J. II. (1980) "Effects of Cadmium on the Completely
Mixed Activated Sludge Process." Journal WPCF. 52:2378-2388.
Weber, W.'J.J Corfis, N. H. and Jones, B. E. (1983) "Removal of Priority
Pollutants in Integrated Activated Sludge-Activated Carbon Treatment
Systems." Journal WPCF.( 55:369-376.
Werthman, P. H., Matthews, R. R., Martens, R. R.'and McManus, K. R. (1982)
"Residuals Management at a Combined Industrial/Municipal Wastewater
Treatment Plant." Proc. 14th Mid-Atlantic Ind. Waste Conf. Ann Arbor
Publishing- Ann Arbor, Michigan. 1-14.
Wilson, A. W. (1931) "Case Study of a Potato Chip Producer Discharging to a
Small Municipal Treatment System." Proc. Conf. on Combined Mun./Ind.
Wastewater Treat. EPA-600/9-81-021. U.S. EPA, Ada, Oklahoma. 329-352.
Wilson, T. E., Lukasik, G. and Ogle, D. (1980) "Treatment of a Filamentous
Industrial Waste in a Municipal Step Aeration Plant.." Prog. Wat. Tech.
12:189-199.
Wood, K. N., Hunt, O. R. and Anderson, J. J. (1983) "Carbon Treatment of
Pesticide Wastewaters in Light of Best Available Technology Effluent Limitation
Guidelines." Proc 37th Ind. Wastes Conf. Ann Arbor Publishing, Ann Arbor,
Michigan. 451-463.
Wozniak, D. J. and Huang, J. Y. C. (1982) "Variables Affecting Metal Removal
from Sludge." Journa' WPCF. 54:1574-1580.
Wozniak, D. J. and Huang, J. Y. C. (1982) "Variables Affecting Metal Removal
from Sludge." Journal WPCF. 54:1574-1580.
Wu, Y. C., Kennedy, J. C., Gaudy, A. F., Jr. and Smith, E. D. (1982) "Treatment
of High-Strength Organic Wastes by Submerged Medi- Anaerobic Reactors:
State- of-the-Art Review." Proc. First Int'l Conf. on Fixed-Film Biological
Processes. Univ. of Pittsburgh. 1212-1238.
Yall, I. and Sinclair, N.A. (1971) "Mechanisms of Biological Luxury Phosphate
Uptake." U.S. EPA, Project No. 17010 DDQ, Washington, D.C., 77 pp.
Yost, K.J., Wukasch, R.F., Adams, T.G. and Michalczyk, B. (19S1) "Heavy Metal
Sources and Flows in a Municipal Sewage System: Literature Survey and Field
Investigation of the Kokomo, Indiana Sewage System," EPA-600/2-81-244. U.S.
EPA, Cincinnati, Ohio. 282 pp.
Yu, T. S., Jiang, M. L. and Denny, R. G. (1984) "Evaluation of Nitrification
Performance by Rotating Biological Contactors." Proc. 2nd Int'l. Conf. on
Fixed-Film Biological Processes, 1405-1426.
Yurovskaya, E. M. (1982) "Microbial Nitrification in Coking Plant Wastewater."
Sov. J. Water Chem. Technol. 4:106-111.
123

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Zogorski, J.'S. (1984) "Comoarison of RBC Treatment Performance Between the
Conventional (Hydraulic) and an Alternative (Organic) Flow Configuration."
Proc.( 2nd Int'l Conf/on Fixed-Film Biological Processes. Univ.'of Pittsburgh.
906-927.
Zwikl, J. R., Buchko, N. S. and Junkins, D. R. (1982) "Physical/Chemical Treat-
ment of Coke Plant Wastewaters." Environ. Prog. 1:244-251.
124

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APPENDIX A
INTERFERING SUBSTANCES
CONVENTIONAL AND INORGANIC
Alkalinity
Ammonia
Biochemical Oxygen Demand
Chemical Oxygen Demand
Chloride
Fats, Oil and Grease
Iodine
Iron Salts
Nutrients
pH
Sulfate
Sulfide
Surfactants
Suspended Solids
METALS
Arsenic
Barium
Beryllium
Boron
Cadmium
Calcium
Chromium
Cobalt
Copper
Cyanide
Iron
Lead
Magnesium
Manganese
Mercury
Molybdenum
Nickel
Selenium
Silver
Sodium
Tin
Vanadium
Zinc
AGRICULTURAL CHEMICALS
Aklrin/Dieldrin
Chlordane
Chlorophenoxy Herbicides
DDT
Endrin
Heptachlor
Lindane
Malathion
Organometallic Pesticides
PCBs
Toxaphene
AROMATICS
Benzene
Chlorobenzene
Dichlorobenze
Hexachlorobenzene
Nitrobenzene
Toluene
Xylene
125

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HALOGENATED ALIPHATICS
Carbon Tetrachloride
Chloroform
Dichloroethane
Dichloroethylene
Dichloropropar.e
Hexachlorobenzene
Hexachlorobutadiene
Hexachlorocyclohexane
Hexachloroethane
NITROGEN COMPOUNDS
Acetanilide
Acetonitrile
Acrylonitrile
Aniline
Benzidine
Benzonitrile
Chloroaniline
Dichlorobenzidine
Dimethylnitrosamine
OXYGENATED COMPOUNDS (Acids,
Ketones)
Acetone
Acrolein
Adipic Acid Esters
Allyl Alcohol
Benzoic Acid
Boric Acid
Butanol
Butyl Benzoate
Chlorobenzoate
Chloroethyl Ether
Cinnamic Acid
Crotonol
Cyclohexanecarboxylic Acid
Diethylene Glycol
Ethoxy Ethanol
Ethyl Acetate
Methylene Chloride
Tetrachlorodibenzodioxins
Tetrachlorodibenzofurans
Tetrachloroethane
Tetrachloroethylene
Trichloroethane
Trichloroethylene
Vinyl Chloride
Dyes
EDTA
Ethylpyridine
Fluorenamine
Hydrazine
Nitrosodiphenylamine
Pyridine
Trisodium Nitrilotriacetate
Urea
Alcohols, Aldehydes, Esters, Ethers,
Ethylene Glycol
Formaldehyde
Formic Acid
Heptanol
Hexanol
Isophorone
Linoleic Acid
Malonic Acid
Methanol
Methylethyl Ketone
Methylisobutyl Ketone
Octanol
Polyethylene Glycols
Polyvinyl Alcohols
Protocatechuic Acid
Syringic Acid
126

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PHENOLS
Catechol
Chlorophenol
Cresol
Dichlorophenol
Dinitrophenol
Pentachlorophenol
Phenol
Trichlorophenol
Trinitrophenol
Vanillin
Nitropheno]
PHTHALATES
Dimethylphthalate
D.iocty ipnthalate
Ethylhexylphthalate
POLYNUCLEAR AROMATIC HYDROCARBONS
Anthracene	di-Isopropylnaphthalene
Benzo (a) Anthracene	Naphthalene
Chloronaphthalenes	Pyrene
127

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APPENDIX B
PROJECT FORMS
DfTKrKRXKCm ATPOTWe
UTHUTT7IU RJCVTXW
Authorei
TltWi					
CltltlflRl
JMHRntarai		JMM Code:
•	On a icale of 1 (lowett) to 10 (highest), rat* this reference in term* of itx
applicability to tlus EPA project __	technical quality 	
•	The focus of ihi* refereeem >ui
contaam«ni treatability in a POT* unit procea* Q
impact of cocumment tm POT* proc«*» operation | |
other (specify)
•	The conclusions of the study »ase baaed am
bench teal* tasting Q	treatment plant record*/teat log O City/?lant Namei
pilot icaia testing Q literature	Q
•	In the space provided below, list the treatment procaaaaa (PROCESS) analysed is the study, the Industrial waate or
contaminate (CAUSE) identified, any immediate or secondary effect* (EFFECT on the treatment proeeea, and action*
useful in mitigating the negative affect* (RESPONSE). Include quantitative information on loading*, concentrations
etc. U a biological treatment process la considered, indicate whether the bacterial populations vera acclimated to the
contaminants. Use tba back oI this sheet If additional apace ta required.
PROCK31	CA03E	KTTtCT	RESPOMSK
e What other variable* ware considered in this work, and bo* did they impact the proc*** or contaminant? Be specific.
• Any other relevant information tram thi* reference?
128

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INTERFERENCES AT POTWs
STATE AGENCY TELEPHONE SURVEY
State:	Date:
Agency:		
Office/Section: 	 Agency Contact:
Phone No.: ( )	 JMM Staff Members:
EXPLANATION: We have been contracted by EPA to prepare a guidance manual
for operators pertaining to interferences at POTWs. One of our
project tasks is to survey all state regulatory agencies in order
to uncover specific operations problems created by the
introduction of contaminants from industrial sources.
QUESTIONS	ANSWER	COMMENTS
• How many municipal treatment
plants do you have subject to
state or EPA regulations?
• Do you compile data on NPDES
Permit violations other than
Quarterly Non-compliance
Reports sent to EPA?
• To what extent are these
violations related to industrial
discharges?
• Have there been problems in
POTW operations associated
with industrial discharges? Are
summary data available?
• Does documentation exist on
specific case histories?
• Are there other contacts I can
make within your state that
might prove helpful?
END OF CALL
Further Action Required?
129

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INTERFERENCES AT POTWs
TREATMENT FACILITY SITE VISIT
JMM Staff Member:	
Date:		
General Information
A.	Plant Name: 	
B.	Address:
C.	Telephone No.: 	
D.	Key Personnel:
Name	Title
E.	Capacity:	 Ave. Flow: 	 Pop. Served:
F.	NPDES Permit:
Permit No. 	 Date Issued: 	
Receiving Water	
Discharge Limits BOD5 = 	 mg/1
T3S = 	 nog/1
NH3 = 	 mg/1 (summer)
	 mg/1 (winter)
Other 	
Plant History
A.	Date of initial construction: 	
B.	Significant upgrades:
Year	Descripf' •>..
130

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3. Flow Diagram
Sketch or attach a flow diagram of the wastewater treatment facility,
indicating the number and size of each major process component.
131

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4. Plant Operations - Liquid Processing
A.	Preliminary:
Racks/Screens 	
Shredding		
Grit Removal 	
Flow Measurement	
Other		
B.	Primary Treatment:
Scraping/Skimming	
Sludge Pumping 	
Detention Time 	 Overflow rate 	
C.	Secondary Biological Treatment:
Fixed Film	 Suspended Growth
Process		 	
Aeration			
Organic Loading 	 	
Recirculation " 	 	
Detention Time 	 	
D.O.		 	
MLSS		
F/M		
MCRT		
SVI		
D.	Secondary Clarification:
Scraping/Skimming	
Sludge Pumping 	
Detention Time	Overflow rate 	
E.	Disinfection:
Chemical Feed 	 Residual 	
Detention Time 	 Coliforms 	
F.	Other:		
132

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Plant Operations - Sludge Processing
A. Thickening:
Process
Solids Loading
Chemical Feed
Return Flow
Other
B. Stabilization:
Process
Detention Time
Chemical Feed
Withdrawal
Return Flow
Other
C. Dewatering:
Process
Solids Loading
Chemical Feed
Return Flow
Other
D. Disposal:
E. Other:

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6. Performance Data
Indicate in the space provided (or attach) any relevant performance data
for typical and upset conditions. Include design data if available.
A. Treatment Plant Influent:
B. Primary Clarifier Effluent:
C. Treatment Plant Effluent:
D. Sludge:
134

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7. Industrial Discbarges
A. Pretreatment Program:
Effective Date		 Local Limits
Total No. Industries 	
Categorical Industries 	
B. Significant Contributors:
Industry	Flow	Pollutants (Concentrations)
C. Waste Haulers:
Number 		Approximate Flow
Types of Waste 	
135

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8. Interferences
A. Compliance Record:
B. Chronic Problems: (include rate of pollutant introduction)
	Cause		Effect	Detection/Mitigation
136

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8. Interferences (cont.)
C. Isolated Problems:
Cause	Effect
D. Comments:
Detection/Mitigation
137

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9. JMM Evaluation
	Category		Rating*		Comments
A.	Management:				
B.	Operations:			
C.	Maintenance:				
D.	Laboratory:				
E.	Pretreatment Program:			
* Rating Code: 1 = Excellent, to 5 = Poor
10. Miscellaneo us Comments
138

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APPENDIX C
CASE STUDY REPORTS
INDEX
Plaint	Page
Bayshore (Union Beach, NJ) 	. . *		140
Hamilton Township (Trenton, NJ)		143
Passaic Valley (Newark, NJ)		146
Binghamton - Johnson City (Binghamton, NY)		149
Canandaigua, NY 		151
East Side (Oswego, NY)		154
Hatfield Township (Colmar, PA)		157
Maiden Creek (Blandon, PA)		160
Rocky Creek (Macon, GA)		163
City of Baltimore (Baltimore, MD) 		166
Back River (Baltimore, ML) 		167
Patapsco (Baltimore, MD)		169
Raeford, NC 		172
Neuse River (Raleigh, NC) 		175
Horse Creek (North Augusta, SC)		178
North Shore (Gurnee, IL)		181
Rockford, IL 		184
Lake Mills, IA		187
Marshalltown, IA		189
Sioux City, IA		192
Newark, OH		195
91st Avenue (Phoenix, AZ) 		198
Tolleson, AZ 				201
Victor Valley (Victorville, CA)		204
Duck Creek, Paw Paw (Denison, TX)		207
Paris, TX 		211
Post Oak (Sherman, TX)		214
Newberg, OR	.		216
Metro (Seattle, WA) -		219
139

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BAYSHORE REGIONAL SEWERAGE AUTHORITY
Union Beach, New Jersey
The Bayshore Regional Sewerage Authority (BRSA) operates an activated sludge
treatment facility whose performance is largely dictated by a single industrial
waste discharger. Three manufacturers of flavors-and fragrances (one of whom
is a perfume retailer) represent the total industrial wastewater flow of
325,000 gpd, or less than 5 percent of the POTW total. All three industries
discharge high concentrations of conventional pollutants and routinely violate
the maximum allowable monthly concentration limits for BOD (500), COD (1500)
and TSS (500) as specified in their industrial waste permits. Two of the three
manufacturers contribute less than 0.5 percent of the POTW flow, hence their
impact is minimal. However, one building of the largest industry produces in
excess of 200,000 gpd of wastewater with the following characteristics (in mg/1):
Parameter
BOD
COD
TSS
Ave.
1004
3238
776
1984
Monthly
High
2054
4998
1835
Monthly
Low
245
1440
94
Ave.
2624
7084
1113
October 1985
Daily
High
5250
11380
1698
Daily
Low
522
2520
672
The large variation in wastewater quality indicates that an activated sludge
pretreatment system located at the industry at times produces a suitable
effluent, but is obviously not sufficient to meet the fluctuating demands of their
process wastes.
The potential impact of such an industrial discharge is evident when analyzing
Figure C-l. The bar graph represents the percentage of total BOD being
contributed by the industry on a daily basis. The upper plot on the line graph
corresponds to the mass BOD loading, with the industry's contribution plotted
beneath. This graph clearly demonstrates that the effluent from this single
industry has increased the BRSA plant loading above the design limit of
15,000 pounds of BOD per day.
The BRSA has been particularly aggressive in their dealings with the industry in
question. Since the manufacturer is not a retailer, adverse publicity has little
effect, particularly since the industry is the largest employer in town. Conse-
quently, the BRSA has taken a two-pronged approach:
•	notification of violation and intent to pursue fines with a subsequent
discontinuation of service if noncompliance persists after 30 days,
and
•	legal action to recover $1.25 million in back surcharge payments and
costs.
140

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•OO COMPANION
7
7
2
i
to 11 12 ti K ts it >t is i« 20«i aaat 74 asn ar at a# soai
i
OCTMM Ittt
IMMJtTDV WK> At % OF TOTAL *00
tO |		
i a a 4 t t r t t 10 it ia is 14 it it tr it it aoai aa aa t4 at at ar at at to
OCTOMA Ittt
Figure C-l
Impact of Industrial Waste Discharge on POTW Loadings
October 1985
A similar approach proved successful during the 1960's, when the Keansburg, NJ
water treatment plant was pumping the contents of their backwash water
storage tank into the sewer system approximately twice per year. In the absence
of am industrial wastewater permitting system, the BRSA's only recourse was to
take the Keansburg authority to court and have them disconnected until a
backwash recycle system could be installed at the water treatment plant.
141

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BAYSHORE REGIONAL SEWERAGE AUTHORITY
Union Beach, New Jersey
Design Flow:
Secondary Treatment:
8.0
Activated Shidge
(Modified Contact Stabilisation)
Location:
Population Served:
Eastern shore
80,000
INFLUENT WASTEWATER
SIGNIFICANT INDUSTRIES
Ave. Flow, mgd
% Industrial
BODg, mg/1
SS, mg/1
Typical (Upset)
6.6
5
220 (380)
250 (400)
Industry
Flavors & Fragrance*
(3 industries)
Flowrate
(1000 gpd)
325
Problem Pollutants
BOD, TSS, COD
Primary Clariflers
Overflow Rate, gal/sf/day
Detention Time, hours
Effluent BOD$, mg/1
Effluent SS, mg/1
Secondary Clarlfiers
Overflow Rate, gal/sf/day
Detention Time, hours
SV1, ml/gm
PLANT LOADING
Typical (Upset)	Aeration Basins
825
1.75
150 (aso)
100 (200)
Typical (Upset)
540
3.35
125 (500)
F/M, lbs BOD5/lbs MLSS/day
MCRT, days
MLSS, mg/1
Return Flow, %
Detention Time, hours
Cont act
Reaeration
Typical (Upset)
0.65 (1.25V
8-10
2000-2500
25
3
12
PLANT PERFORMANCE
Permit Unit	Typical (Upset)
BOD5, mg/1 30	35 (400)
SS, mg/1 30	27 (80)
D.O. mg/1 5	2-5
RAW
WASTEWATER
FINAL
EFFLUENT
RAKE
CLARIFIER
RA8
PRIMARY
CLAAIFIER9 (4)
SECONDARY
(CLARIFIERS]
V <*> J
CYCLONE
OEQRITTER
WAS
BELT FILTER
PRES8ES
ASM TO
SLUDOE LAGOON
f<2)
INCINERATOR
f GRAVITY
HICKENERl
. (2)
CHLORINE
CONTACT
CHAMBERS
(2)
AERATION
BA8IN8
(4)
142

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HAMILTON TOWNSHIP WASTEWATER TREATMENT PLANT
Trenton, New Jersey
The Hamilton Township Wastewater Treatment Plant (HTWTP) is an unusual
facility in that plant upgrades over the past 30 years have been constructed as
parallel flow processes rather than as replacements for older, outdated techno-
logy. Although this results in a complicated plant schematic (see below), parallel
flow paths do provide operational flexibility and an opportunity to study the
impact of a combined industrial/domestic wastewater on different fixed-film
biological treatment processes. The HTWTP has had a difficult time meeting its
permit limit for BOD over the past few years, and is currently under a Consent
Order and Agreement and Compliance Schedule from the State Department of
Environmental Protection.
Despite being at just over 50 percent of the plaint's hydraulic capacity, Hamilton
Township has experienced organic overloads, resulting in at least partial failure
of 15 of the 48 RBC units. With the advent of an Industrial Waste Monitoring
Program as part of a Sewers and Sewage Disposal Ordinance, the reasons for
such overloading became apparent. Although the industrial waste program is
still in its' infancy, observations and analytical data have identified a pharma-
ceuticals manufacturer as a significant and potentially harmful discharger to the
POTW.
Dating back to the summer of 1984, high concentrations of volatile organics
were being discharged to the POTW on a once or twice-per-week basis. A
monitoring program at the HTWTP uncovered ail increase in influent BOD from
150 to 3 50-500 mg/1 and high atmospheric levels of organic constituents with
this discharge pattern. The specific industry was identified when a high influent
pH reading lead Hamilton Township personnel to the pharmaceuticals manu-
facturer in March, 1985. Sampling conducted at that time detected significant
levels of ethyl benzene, toluene and xylene in the industry's effluent. These
findings precipitated an extensive testing program by the Township, with an
independent engineering study conducted by the industry. The results indicated a
correlation between the pharmaceutical discharges and high influent soluble BOD
at the POTW. Analyses conducted on the industry's flow streams resulted in the
following calculated average effluent concentrations:
Parameter	Concentration (mg/1)
Arsenic	2.6
Phenols	25.7
Total Toxic Volatile Organics (TTVO)	1.3
BOD	21,800
TSS	557
TDS	65,800
Based on an average flow of 15,000 gpd, these wastewater characteristics should
not be harmful to an 8.5 mgd facility if discharged on a steady basis. It is the
intermittent discharge of this wastewater which has contributed to the over-
loading of the biological population of the POTW.
143

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During a three week shutdown of the industry in July of 1985, the HTWTP
recovered to the point of meeting their permit limits. Consequently, the
Township only permitted the industry access to the sewer system after the
installation of metering pumps to equalize flows. This requirement initially
improved POTW performance during the Fall of 1985, but a gradual deterioration
in effluent quality (indicating possible toxicity effects) lead the Township to
terminate service to the industry in late-November.
While the most recent action is being challenged, the industry is constructing an
anaerobic pretreatment facility on site which should reduce the financial impact
of a surcharge to be instituted with the next version of the industrial waste
management program.
A number of operations and personnel changes have been instituted at the
HTWTP to help mitigate the impact of the industrial discharges. These changes
include:
•	installation of aeration equipment in the influent channels to the
RBCs to increase the first stage DO to 2-3 mg/1;
•	extensive use of sludge judges and visual monitoring to augment
reliance on control room instrumentation;
•	performance of bioassay testing by an independent contractor to
assess toxicity effects;
•	purchase of a toxicity tester to be used in calculation of local limits
for toxic contaminants; and
•	hiring of four more people plus the purchase of a vehicle for an
extensive industrial sampling program.
At this time, only a few industries have been sampled to any degree. One of the
electroplaters in town was discovered with up to 60 mg/1 of cadmium and
160 mg/1 of chromium in their wastewater. Although pretreatment has not been
installed, conservation efforts on the part of the industry has reduced their
discharge from 14,000 to under 10,000 gpd.
144

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HAMILTON TOWNSHIP WASTEWATER TREATMENT PLANT
Treat os, New J«ntf
Design Flow:
Secondary Treatment:
16 «|d
Trickling Filter tod RBC
Location:	Central West*
Population Served: 87,000
INFLUENT WASTEWATER
SIGNIFICANT INDUSTRIES
Ave. Flow, mgd
% Industrial
BOD$, og/1
SS, mg/1
Typical (Upeet)
8.5
10 (est)
240 (500)
160 (400)
Industry
Pharmaceutic*]
Electroplaters (2)
Flowrate
(1000 gpd)
15
160
Problem PoUutaat*
BOD, phenol, ethyl benzene, toluene, xylene
Cd, Cr, Zn, Ni
Primary Clarl(l«ni
Overflow Rate, gal/sf/day
Detention Time, hours
PLANT LOADING
Typical (Upaet)	Trieliiag I Ut«
630, 260, 320
1.8, 4.8, 5.6
Plant Flow (mgd)
Hydraulic Loading, gal/sf/day
Organic Loading, lbs BOD/1,000 cf/day
Return Flow, %
Typical (Upaet)
2.5, 1.0
100, 210
15, 16 (30)
20,100
Stcoadary CUrlflm
Overflow Rate, gal/sf/day
Detention Tlcne, hours
Typical (Upset)
520, 260, 265
2,8, 4.8, 6.8
RBCa
Plant Flow (mgd)
First Stage Organic
Loading, lbs BOD/1,000 sf/day
-	Total
-	Soluble
PLANT PERFORMANCE
Per nit Limit
BOD5, mg/1
SS, og/1
NHj, og/1 (Effective 6/86)
30
30
10
Typical (Upeet)
45 (100)
20 (50)
20 (30)
Typical (Upaet)
5.0
5.3 (10.8)
3.5 (6.7)
RAW

BAR
SCREENS
FINAL
EFFLUEN7
RECYCLE
GRIT • /
CHAMBEH8
VACUUM
FILTER
CHLORME
CONTACT
CHAMBER
PRIMARY
CLARIFIER
SECONDARY
CL ARIFIERS
(6)
RBCa
6 W/S SHAFTS
145

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PASSAIC VALLEY WASTEWATER TREATMENT PLANT
Newark, New Jersey
Coping with industrial waste discharges to a 300 mgd POTW in a highly
industrialized area is a challenging task. The Passaic Valley Sewerage
Commissioners (PCSC) maintain an industrial waste control staff to monitor
nearly 400 industries that contribute 20 percent of the wastewater volume and
50 percent of the waste strength. The PVSC performed their first Industrial
Waste Survey for database development in 1972, and adopted a set of Rules and
Regulations (including local limits) in 1976. By 1982, a comprehensive system
consistent with the Federal Clean Water Act of 1977 had been adopted, which
established uniform user fees for mass and volumetric loadings in the Passaic
Valley plant.
The influent wastewater to the POTW is considered a high-strength waste, with
typical BOD and TSS values of 290 and 450 mg/1, respectively. Despite the
strength of the influent, the plant is close to meeting the 30/30 NPDES discharge
limits, even though the primary clarifiers are not scheduled to go on-line until
later this year (1986). The PVSC believes that the addition of primary treatment
coupled with the economic incentives for pretreatment created by the user
charge system will reduce the effluent to consistently below the limits.
The individual constituents of concern to the PVSC fall into three general
categories:
•	metals
•	flammables
•	fibers
The sources of heavy metals are chemical manufacturers, platers and tanneries.
One of the smaller (30,000 gpd) chemical companies had been identified as a
signficant contributor (120 lbs/day) of mercury to the POTW. Although the
mercury level of 50 ug/1 at the influent was not inhibitory to the activated
sludge, the concentration of mercury in the sludge limited the municipality's
disposal options. It is anticipated that ocean disposal of sludge will not be
permitted much longer, which will require the PVSC to incinerate. The Federal
Air Pollution Standards limit the mercury discharge to 3,200 g/day, which
translates into a local limit of 0.4 lbs/day in the wastewater from the industry in
question. The chemical company responded by isolating the relevant process
streams and utilizing a batch recovery system for the mercury, reducing the
discharge from 120 down to 5 lbs/day. When ocean disposal is formally
eliminated as a disposal option, the company can employ carbon treatment for
removal of the remaining mercury.
The oxidation of trivalent chromium to the hexavalent. form in a POTW sludge
incinerator is a problem caused by the chromium-ladon discharge from various
industrial users. An additional problem caused by the tanning industrial category
is the clogging of local sewers that results from hides being inadvertently
discharged from the companies. Similar clogging problems existed at the
pretreatment plant due to the balled-up fibers from the pulp and paper
146

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manufacturers which close off sludge return line", orifices and nozzles. This
condition improved substantially when the moving-bridge primary clarifiers were
placed in service in December, 1985.
The Passaic Valley plant had a unique problem with high concentrations of
flammable materials in the influent wastewater. The lower explosive limit (LEL)
is defined as the "lowest concentration of a combustible substance in air through
which a flame, once ignited, will continue to propogate". When a wastewater
approaches 50 percent of the LEL, it is important that it not be discharged into
the sewer collection system. The pure oxygen process has a control built into
the system which vents all oxygen away from the activated sludge treatment
process when high LEL is detected. Since the venting of the oxygen reduces the
treatment efficiency and can result in a permit violation, such discharges are not
only health hazards, but interferences as well.
The PVSC instituted a three-part program in October of 1984 to mitigate the
problems of flammables:
•	required industries using or manufacturing solvents which come in
contact with discharged wastewater to install LEL detection
instruments, and to provide pretreatment to isolate the flammables if
high LELs were detected;
•	surveyed other industries which used solvents but 'had no such
discharge to determine if a potential existed, requiring necessary
control mechanisms; and
•	monitored the collection system more closely for illegal dumping of
such chemicals.
Representatives of Passaic Valley made it clear that a cooperative attitude on
the part of industry was an important factor in successful mitigation of
interference pro' l^ms. In fact, it was the local pharmaceutical manfacturer
that conducted the research resulting in the type of LEL instrument
recommended by the Advisory Committee when the LEL regulation was adopted.
147

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PASSAIC VAX-LEY WASTEWATER TREATMENT PLANT
Newark, New Jcnmy
Design Flow:
Secondary Treatment:
330 mgd
Activated Sludge
(Pure Oxygen)
Location:
Population Served;
Adjacent to Newark Bay
1.5 Million
INFLUENT WASTEWATER
SIGNIFICANT INDUSTRIES
Ave. Flow, mgd
% Industrial
BOD$, mg/l
SS, mg/l
Typical (Upeet)
250
19
liO ($00)
4SO (7S0)
Industry
Pulp and Paper (2)
Pharmaceutical*
Tanneries (3)
Chemicals (3)
Flowrate
(mgd)
10.3
6
l.S
0.5
Problem Pollutant*
Fibers
Xylene, Toluene, Hexane
Cr
Cd, Cr, Hg, Pb
PLANT LOADING
Primary ClaxifVerm
Overflow Rate, gal/sf/day
Detention Time, hours
Effluent BOD$r mg/l
Effluent SS, mg/l
Secondary Clarifterv
Overflow Rate, gal/sf/day
Detention Time, hours
SVI, ml/gm
Typical (Upeet)
1,100
2.0
225
125
Typical (Upeet)
480
5
65
Aeration Wait—
F/M, lbs BOD5/lbs MLSS/day
MCRT, days
MLSS, mg/l
Detention Time, hcurs
Return Flow, %
D.O. Level, mg/l
Typical (Upeet)
0.6
5
2,800
1.6
35
4-12
BOD$, mg/l
S$, mg/l
PLANT PERFORMANCE
Permit Limit
30
30
Typical (UpeeO
25 (40)
25 (60)
RAW
WASTEWATER
GRIT
CHANNELS
RACKS
AND
SCREENS
CLARIFIERO
RA8

1
IXYQENATIOti

SECONDARY
BA8IN8

CLARIFIER8
(a)

(12)


FINAL
EFFLUENT
(OCEAN)
SLUDGE
THICKENERS!
(12)
HEAT
TREATMENT
(Z1MPRO)
CLARIFIER
(4)
OXYGENATION
TANK8
SLUDGE
8TORAQE
(6)
DECANT
TANKS
(6)
OCEAN
DISPOSAL
1 43

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BINGHAMTON-JOHNSON CITY JOINT SEWAGE TREATMENT PLANT
Binghamton, New York
In 1981, the Binghamton-Johnson City Joint Sewage Treatment Plant had to
terminate landspreading of sludge because the sludge did not meet the cadmium
criteria established by the New York State Department of Environmental
Conservation (NYDEC) for such disposal. A paper coating industry in
Binghamton was the only identified industry that used and discharged high
concentrations of cadmium. The industry cooperated with the Joint Sewage
Authority and reduced their cadmium discharge levels by installing a
pretreatmer.t system that utilizes ammonia stripping followed by metal
precipitation. During the 1975-1979 period, cadmium levels in the sludge from
the Joint Sewage Treatment Plant were n the range of 100 to 150 mg/kg. In
1982, the level was reduced to 53 rag/kg, and presently the level is at 15 mg/kg.
The cadmium limit imposed by the N f DEC for land spreading of the sludge is 25
mg/kg. The treatment plant is presently landfilling sludge but intends to install
sludge composting equipment in the future.
There are approximately twelve significant industries contributing flow to the
Joint Sewage Treatment Plant. There are several electroplaters who discharge
metals, (other than cadmium), to the plant. Most of the electroplaters have
installed pretreatment equipment in order to comply with industry categorical
standards. The Binghamton-Johnson City Joint Sewage Board adopted rules and
regulations effective March 1, 1985 that gave the board direct control over
industrial wastewaters discharged to the sewage treatment plant. In the near
future the Joint Sewer Board will issue industrial discharge permits in order to
enforce local limits which will be set to ensure compliance with state water
quality standards, (which are presently being revised), and sludge disposal
criteria. At the present time, chromium, zinc ind nickel concentration levels in
the sludge occasionally approach or exceed tie NYDEC landspreading limits.
The imposition of local industrial waste discharge limits are expected to result in
reduction in metal levels in the sludge to acceptable levels.
The Joint Sewage Treatment Plant has had consistent operational problems
associated with biosolids losses frc.m the secondary clarifiers. The poor
operation of the clarifiers has been due to severe short circuiting as well as
hydraulic surges from infiltration/inflow and stormwater flows. The Joint
Sewage Board is presently undertaking corrective action to alleviate the
problem. The secondary clarifiers are being modified by the addition of new
influent baffling and the relocation of the effluent weirs. The reduction of
infiltration/inflow and stormwater flows into the plant will be reduced by
extensive sewer system rehabilitation.
149

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VNGHAMTON - JOHNSON CITY JOINT
SEWAGE TREATMENT PLANT
BMGHAUTON, NEW YORK
Design Flo*:	19	Location:	Ccttlral N»« York
Secondary Treatment: Activated Shalf*	Population Served: 129,000
(CoapWtaty MLaW or
Contact StaMUaalhoa)
INFLUENT WASTEWATER
SIGNIFICANT INDUSTRIES
Ave. Flow, rogd
% Industrial
BOD^ mg/l
SS, reg/l
Typical (UyMtJ
20
1
210
210
Mwtry
Paper Coating
Electroplaters
Flowrate
(IOOP gp4)
2 £0
JS
PrakUa fS>ll*tMU
Cadreiura
Zinc, Nickel, Chromium
PLANT LOADING
Pfriaary CUHIkm
Typical (Upaat)
A*ratkm Baiiaft
Typical (Upbcl)
Overdo* Rate, gal/sf/day
Detention Time, hour*
Effluent BOD^, reg/l
Effluent SS, cog/1
Secondary CUri(i«n
Overflow Rate, gal/sf/day
Detention Tire*, hours
S\1, rel/gre
1,000
2
US
95
Typical (Upaat)
8S0
2.S
170
MCRT, days
MI.SS, reg/l
Detention Tire*, hours
O.O. Level, rag/1
2-S
2,S00
2
2
PLANT PERFORMANCE
P*r»it UmK	Typical (Upaal)
RiiiMir of
Susmt	Year
BOD$, reg/l	4S	70	SS
SS, reg/l	80	100	90
SLUDGE METAL CONCENTRATION
1942	PMt
I U»il Lml	Ui« 1
C.'admium, mg/kg 25 53	IS
Chromium, rag/kg 1,000 689	840
Nickel, rag/kg 200 219	)19
CHLORINE
CONTACT
CMAMfttM
LANOfIII
PRIMARY
CLAftlPltftt
(•)
•CCONOAAY
ClARtPlC**
(•)
aeration
• AftlMt
(•)
150

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CITY OF CANANDAIGUA WASTEWATER TREATMENT PLANT
Canandaigua, New York
During its first year of operation, the City of Canandaigua Wastewater
Treatment Plant failed to meet its NPDES Permit limits for BOD and Ultimate
Oxygen Demand (UOD)* approximately half of the time- Violations were due to
high influent organic loads from a winery in the city. In 1982, the winery
discharged an average flow of 100,000 gpd having a BOD concentration of 3,500
mg/1. This was in violation of the discharge limitations that were in effect for
the winery under the sewer use ordinance. The pretreatment limits for the
winery had been set at the following concentrations:
The City of Canandaigua initiated court action against the winery in early 1983
for violations of the sewer use ordinance. Subsequently, the city and winery
agreed out of court on a compliance schedule for the winery.
The limits in the sewer use ordinance v/ill be integrated into the industrial
discharge permit that will be issued to the winery in the near future. The winery
expanded its pretreatment facility and in 1984 its discharge had an average BOD
concentration of 400 mg/1. The City of Canandaigua Wastewater Treatment
Plant operation has improved dramatically as its effluent met its discharge
permit requirements for all of 1984.
The City of Canandaigua Wastewater Treatment Plant uses air driven rotating
biological contactors (RBCs) i'or carbonaceous organics removal followed by
nitrification. In 1982, the RBCs were not effectively removing CBOD or
ammonia from the wastestream because of excessive organic overloading from
the winery. In addition, the organic overload caused excessive growth on the
RBCs resulting in inadequate rotation of the units. During 1982, up to half of
the RBCs were not operational.
The winery, which is the only major industry in the city, had increased
production and was overloading its existing pretreatment facility in 1982. Aii a
result of the agreement in early 1983 that set a compliance schedule, an
expansion of the winery's pretreatment facility was on line by late 1983. Both
the original and expanded pretreatment systems utilize an extended aeration
activated sludge process for organic concentration reduction. The winery's
expanded pretreatment facility has experienced problems with filamentous
UOD = (1.5 x CBOD5) + (4.5 x TKN), where CBOD5 is the five day
carbonaceous biochemical demand and TKN is total nitrogen.
Suspended Solids
Total Kjeldahl Nitrogen
Phosphorus
COD
BOD
600 mg/1
300 mg/1
350 mg/1
55 mg/1
10 mg/1
151

-------
organism growth in its sludge. The winery is attempting to control this problem
through chlorination. The City of Canandaigua Wastewater Treatment Plant has
not experienced problems with sludge bulking in their secondary clarifiers.
Generally RBC sludge does not tend to bulk and additionally the use of ferric
chloride for phosphorus removal prior to secondary clarification further enhances
kludge settleability. Bulking of the sludge has occasionally occurred, however, in
the city's sludge gravity thickeners. The winery periodically exceeds its organic
discharge limits due to pretreatment plant upsets. When this occurs
simultaneously with inflows of leachate and septic tank waste from truckers, a
slight reduction >m g;>s production from the city's anaerobic digestors has been
noted.
152

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CANANDA1GUA WASTEWATER TREATMENT PLANT
CANANDAIGUA, NEW YORK
Design Flow:
Secondary Treatment:
6.5 mgd
Rotating Biological
Contact on
Location:	Central New York St»te
Population Served: 25,000
INFLUENT WASTEWATER
Ave. Flow, mgd
% Industrial
BOD5, mg/1
SS, mg/1
Typical (Upaet)
3.0
3
160 (360)
230
Industry
Winery
SIGNIFICANT INDUSTRIES
Flowrate
(1000 gpd)
100
Problem Pollntarta
aOD, COD
Priaary Clarifiers
Overflow Rate, gal/sf/day
Detention Time, hours
Effluent BOD5, mg/1
Effluent SS, mg/1
Secondary Clarifiers
Overflow Rate, gal/sf/day
Detention Time, hours
PLANT LOADING
Typical (Upaet)	Rotating Biological Contactors	Typical (Upset)
800
2.7
120 (230)
80
Typical (UpMt)
600
3
Organic Loading, lbs BOD$/1,000 sf/d
Hydraulic Loading, gal/sf/day
Carbonaceous Contactors
Nitrification Contactors
1.5 (2.9)
2.5
1.6
PLANT PERFORMANCE
Permit Limit	Typical (Up»'t)
BOD;, mg/1	30	11(45)
SS, mg/1	30	<1
UOD, mg/1
Summer and Fall	50.7	31 (76)
Spring	97.0	22 (148)
Winter	134.0	35 (73)
RAW
FINAL
EFFLUENT
PO«T
AERATION
BASIN
EQUALIZATION
BASIN
AERATED
OR IT
CHAMBER*
 /
AIR-DRIVEN
RBC* |_
> W/S SHAFTS )
SECONDARY
CLARIFIERS
(2)
FLASH FUJCCULATOR
MIXERS
<2)
k-
QHAV1TY
8LU00E
BLBO
TANK
BELT FILTER
PRESSES(a)
153

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EAST SIDE SEWAGE TREATMENT PLANT
Oswego, New York
The City of Oswego, East Side Treatment Plant has experienced significant non-
compliance problems associated with the loss of solids from their secondary
clarifiers. Half of the plant's hydraulic flow is from a paper mill which is the
only major industry in the city. From 1981 to 1983, the noncompliance problems
at the plant were attributed to severe hydraulic and organic load peaks from the
paper mill as well as operational difficulties such as frequent breakdowns of the
return sludge pump drives. It is not known whether filamentous growth in the
sludge occurred at that time. In 1983 the paper mill voluntarily reduced the
hydraulic and organic peaks to the plant. Solids losses from the secondary
clarifier still remained a problem. During 1984, the plant frequently exceeded
their NPDES discharge suspended solids by five times the limit and the BOD by
three timcu r.he limit. During that period, the plant still occasionally received
hydraulic peaks from the paper mill which were twice the average rate for two
to three hour periods, but a substantial cause of the problem was identified as
poor sludge settleability due to filamentous growth. The frequent washout of
biosolids from the secondary clarifiers resulted in a low mean cell residence
time and the generation of a young sludge that did not settle well. In the spring
of 1985, the belt drives on the return sludge pumps which had frequently been
out of service were replaced with electronic variable speed drives. This
improvement allowed the plant operators to maintain better control of the solids
inventory in the aeration tanks. Plant performance was still poor, however,
because of sludge bulking.
Several measures have been taken at the plant in an attempt to alleviate the
sludge bulking problem. The measures that were taken are:
•	switching from plug flow feed to a step feed in the aeration tanks in
order to achieve better dissolved oxygen distribution;
•	varying process control strategies such as sludge return and wasting
rates, and sludge blanket depth; and
•	chlorination of the return sludge for the destruction of filamentous
growth in the sludge.
The step feed operation has resulted in better dissolved oxygen distribution but
did not significantly improve sludge settleability. The second two mitigation
efforts were ongoing at the time of writing. A chlorination dosage of
6 lb Cl^/1000 lb solids had been applied to the return sludge. Microscopic
examination of the sludge indicated that the filaments had shrunk and the SVI
level had dropped to the range of 60-80. The plant operators intend to chlorinate
whenever the SVI increases to 150. It has not been determined if these
mitigation measures can result in plant performance that will consistently meet
the permit discharge limits.
The paper mill periodically discharges slugs of waste containing high suspended
solids to the treatment plant. At these times, the sludge in the primary tanks
154

-------
takes on a gelatinous quality which makes sludge removal difficult. High
periodic input of clay filler materials from the paper mill has resulted in poor
sludge incineration with associated high fuel usage.
The City of Oswego is presently preparing an industrial discharge permit for the
paper mill. The permit will restrict the monthly and daily average BOD and
suspended solids levels in the influent from the paper mill as well as restrict the
daily maximum hydraulic peak allowed. Under the permit provisions the paper
mill will be required to submit listings of the chemicals used in their processes.
The paper mill is presently voluntarily investigating the possible relationship of
the chemicals used in their manufacturing processes to the occurrence of
filamentous growth in the activated sludge process.
155

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EAST SIDE SEWAGE TREATMENT PLANT
OSWEGO, NEW YORK
Design Flow:
Secondary Treatment:
3 mgd
Plug or Step Feed
Activated Sludge
Location:
Population Served:
Northern Nee
10,000
York
INFLUENT WASTEWATER
SIGNIFICANT INDUSTRIES
Typical (Upaet)
Ave. Flow, mgd
'o Industrial
2.5
50
industry
Paper Mill
Flowrate
(1000 gpdj
1,Z00
Problem Pollutants
SS, BOD
BOD5, rag/1
SS, rag/1
Municipal Paper Mill
100
120
300
450 (1000)
Primary Clariflera
Overflow Rate, gal/sf/day
Detention Time, hours
Effluent BOD5, mg/1
Effluent SS, rog/1
PLANT LOADING
Typical (Upaet)	Aeration Baaina
Municipal
70
40
600
Z
Paper MU1
UO
100
F/M, lbs BODj/lbs MLSS/day
MCRT, days
MLSS, rog/1
Detention Time, hours
Return Flow, %
D.O. Level, rag/1
Typical (Upaet)
0.2
7 (3)
2,000 (300)
7
25 - 45
2 - ~
Secondary Clariflera
Overflow Rate, gal/sf/day
Detention Time, hours
SVI, ml/gm
Typical (Upaet)
800
2
100 (1000)
PLANT PERFORMANCE
Permit Limit	Typical (Upaet)
Remainder of
Summer	Year
BOD 5, rag/1	30	45	20 (120)
SS, rag/I	30	70	25 (300)
RAW DOME8TIC
WASTEWATER
RAW PAPER MILL
WASTEWATER
i
EFFLUENT
CREEN8
CHLORINE
CONTACT
CHAMBER
QRI
CHAMBERS
PRIMARY
CL ARIFIER8(2
8EC0NDARY
CLARIFIER8
(3)
PRIMARY
ICL ARIFIERS (2X
ORAVITY
HtCKENER
(2)
ASH TO
LANDFILL
MULTIPLE HEARTH
INCINERATORS <2)
156

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HATFIELD TOWNS HIP ADVANCED TREATMENT FACILITY
Colmar, Pennsylvania
The Hatfield Township Municipal Authority (HTMA) operates an advanced
wastewater treatment facility which receives two-thirds of its domestic flow
from Hatfield Township and one-third from Montgomery Township, Pennsylvania.
Although less than 10 percent of the plant flow is supplied by industry, up to
60 percent of the influent waste strength can result from industrial and waste
hauler sources. The HTMA was issued a Consent Order and Agreement by the
Pennsylvania Department of Environmental Resources in March 1985 for non-
compliance with their NPDES Permit due to hydraulic and organic overloading at
the POTW. The Order gives the HTMA until May 1, 1987 to meet a new set of
discharge limits, which, in addition to those shown on the attached data sheet,
includes a 2/6 mg/1 (summer/winter) ammonia limit. A new 6.4 mgd Shreiber
process facility including nitrification/denitrification capability is currently
under construction to meet the goals of the post-1987 permit.
Violations of the total phosphorus limit (2 mg/1) and occasional problems with the
ammonia (32) and BOD (15, summer) limits are the primary reasons for the
Consent Order. The advanced treatment facility has performed well enough in
the area of suspended solids removal that pressure filters installed following the
tube settlers in the flow schematic have been taken out of service. Feeding
FeS04 to the return activated sludge improved the total-P removal from
43 percent to 65 percent, and is enough to consistently reduce the effluent P to
below 2 mg/1.
While industial discharges can not be blamed for exceeding the phosphorus limits,
high influent BOD, SS and nitrogen are directly attributable to a few of the key
industries. The Industrial Wastewater Discharge Permits issued by the HTMA
limit the concentrations of these compounds to the following monthly averages
(in mg/1):
Parameter
BOD
SS
TKN + N02 + NO3
Total-P
FOG



Maximum
Surchargeable
2,000
800
160
20
250
195
180
15
The most significant violator of the discharge limits is a 120,000 gpd industrial
waste pretreatment facility that uses a physical-chemical process for metals
removal and pH neutralization. The average effluent from this plant was
measured in 1984 as:
BOD (soluble)	3109
SS	1718
Nitrogen	586
Total-F	7.7
157

-------
Additionally, numerous organic compounds have been identified in their dis-
charge with concentrations ranging from 10 to 5,500 ug/1, but no interference
due to these organics has been detected to date. Given the nature of the
wastewater, it is not surprising that the HTMA has denied a permit to the
industrial waste pretreater for expansion of their facility. However, the
feasibility of utilizing the existing POTW to treat larger volumes of this
wastewater after the new municipal facility is on-line is now being evaluated.
A second significant contributor of conventional pollutants had been a 17,000 gpd
dairy, who was being surcharged for excess BOD, SS and nitrogen. In this case,
the solution was to truck the whey waste rather than discharge to the sewer,
resulting in a cost savings to the dairy and reduced loadings at the POTW.
A small (1,500 gpd) chemical company was being surcharged $ 10,000 per quarter
for an ammonia discharge of up to 30,000 mg/1. At times, the NH3 concentra-
tion at the POTW influent would reach 100 mg/1. In 1983, the industry installed
a pretreatment system which reduced the NH3 concentration, so that the
company's quarterly surcharge now ranges from $ 1,000 to $ 1,500.
The HTMA permits 13 haulers of septage, holding tank contents and leachate to
discharge 115,000 gpd into the effluent launder of the primary clarifiers. While
this practice generated over $ 350,000 of income in 1984, the impact of these
discharges on the treatment plant are difficult to assess given the limited
sampling of these wastewaters. A single day's testing of the discharges in
April 1985 produced suspended solids results ranging from 23 to 65,000 mg/1, and
COD values of from 800 to 36,000 mg/1. HTMA has estimated that the hauler
wastewater increases the sludge production at the POTW by 40 percent over the
volume generated by the influent wastewater.
158

-------
HATFIELD TOWNSHIP ADVANCED VASTS TREATMENT FACILITY
COLMAR, PENNSYLVANIA
Design Flowt
Secondary Treatment:
3.6 >|<
ActlntW Sfcadf*
(Coapktt MU)
Location:
Population Served:
Soathaaaten Penury lv*mia
20,000
INFLUENT WASTEWATER
SIGNIFICANT INDUSTRIES
Ave. Flow, mgd
% Industrial
BOD5, mg/1
SS, mg/1
NHj, mg/l
Typical (DpaeO
3.4 (6)
10
230 (350)
235 (390)
25 (35)
hliatry
Ind. Waste Treatment
Dairy
Steel (Paint Shop)
Chemical
Waste Haulers (13)
Flowratc
(1000 gpd)
120
17
25
1.5
115
Problem Pollutants
BOD, SS, N, Organict
BOD, SS, NH3
Paint slugs
NH3
COD, SS
PLANT LOADING
Primary Clarifian
Overflow Rate, gal/sf/day
Detention Time, hours
Effluent BOD5, mg/1
Effluent SS, mg/1
Sscndiry ClarifWrs
Overflow Rate, gal/sf/day
Detention Time, hours
SVI, ml/gm
Effluent BOD5, mg/1
Effluent SS, mg/1
Typical (Upaat)
600 (1,050)
3 (1.7)
170
205
Typical (Opaat)
720 (1,250)
3 (1.7)
75
50
75
Aeration Hasina
F/M, lbs BODj/lbs Ml.SS/day
MCRT, days
MLSS, mg/1
Detention Time, hours
Return Flow, %
D.O. Level, mg/1
Typical (Upaat)
0.33
4.3
4,500-5,000
4 (2.2)
50
4
PLANT PERFORMANCE
Permit Unit	Typical (OpaaO
BOD5, mg/1	15/30	12 (20)
SS, mg/1	20	5 (10)
NHj, mg/1	32	24 (40)
NOj ~ NO3, mg/1	N/A	3 (6)
Total-P, mg/1	2	4 (20)
FINAL
EFFLUENT
WASTEWATER
BAR
SCREENS
AERATED
OniT/OREASE
CHAMBER
SECONDARY
CLARIFIER8
(2)
I'OUALIZATIOf
TANKS
(2>
/PRIMARV\
[CLARIFIERI
V <2> J
AERATION
BASINS
(2)
FLOCCULATTON
BA8INS
(2)
TUBE
SETTLERS
(2)
WAS
DILUTION WATER
INCINERATION
ASH TO
LAOOON
159

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MAIDEN CREEK WASTEWATER TREATMENT PLANT
Blandon, Pennsylvania
The Maiden Creek Wastewater Treatment Plant (MCWTP) went on-line in
December, 1981 as a secondary treatment facility designed to remove both
carbonaceous and nitrogenous BOD. The plant uses a patented aerated sub-
merged fixed film biological treatment system, where flat asbestos plates
hanging vertically in the settled wastewater provide a growth surface for the
bacteria. Each of three contact basins contains 320 plates with 200 sq. ft. of
surface area. Oxygen is provided by fine bubble aeration through ceramic
diffusers.
During the first six months of operation following am initial acclimation period,
the MCWTP experienced gradual flow increases from 0.1 to 0.15 mgd while
consistently meeting their permit limits. In August of 1981, a local mushroom
processor began batch discharging high BOD wastewater to the POTW at flows
sometimes exceeding 100 gpm. The hydraulic and organic shock loadings
resulted in nitrifier washouts, solids carryover, reduced BOD removal efficiency
and at times total biological process failure. Although the industry was not
measuring their wastewater flow rates at that time, they were the only
significant non-domestic contributor. After factoring out any potential infiltra-
tion/inflow from stormwater flows, the discharge pattern from the industry was
obvious from an inspection of the weekly flow recordings at the POTW.
Figure C-2 illustrates the dramatic effect of the industrial discharges on the
MCWTP influent.
April, 1982	October, 1982
FIGURE C-2
WASTEWATER DISCHARGE AT INFLUENT METERING STATION (MGD)
160

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As a result of significant time and effort on the part of Maiden Creek Township
Municipal Authority two years ago, the food processor installed a physical-
chemical treatment system which included surge control tanks and aeration. The
system did reduce the solids load and partially mitigated the flow spike problem,
although the surge tanks were not capable of providing complete equalization.
Unfortunately, the great percentage of their organic waste is soluble, so the
pretreatment facility is ineffective in reducing the BOD loading to the POTW.
Additionally, wastewater production far exceeds the 50,000 gpd limit imposed by
their permit, so occasional flow spikes are still evident. The industry has
requested nearly ten times the current flow limit, necessitating the design of a
full secondary system to reduce their waste strength to domestic levels. Such a
system, including a 650,000 gallon aerated equalization basin, is scheduled to go
on-line in mid-1986. In the interim, the municipality has required that the
industry;
•	control flow surges;
•	meter and record their flows continuously;
•	reduce the BOD in the effluent by in-house methods; and
•	composite sample their discharge on a regular basis.
Failure to comply with the abovementioned program will result in a shut off by
the POTW, a measure used previously in February, 1985 when the industry's
wastewater was responsible for total process failure at the plant.
A number of operational changes were instituted in May of 1985 to help combat
the high organic loads in the contact basins. These changes included:
•	increasing the aeration by using all blowers at the plant, resulting in
an increase in the first stage D.O. from 2 mg/1 to 5 mg/1;
•	addition of selective strains of bacteria to increase the rate of BOD
removal;
•	recycling the plant effluent to the head of the plant to dilute the
incoming wastewater; and
•	reducing the allowable flow from the food processor and closely
monitoring their adherence to the limits.
Since these changes were implemented concurrently, it is impossible to isolate
the individual impacts of each operations change. However, the collective result
was a substantially improved compliance record. There have also been no flow
spikes at the POTW since mid-December, 1 985, indicating better flow control on
the part of the food processor.
161

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MAIDEN CROT WASTEWATER TRiATMKNT PLANT
BLANDON, PENNSYLVANIA
Design Flow:	0.45 ngd	Location:	Soatbeaatarn Pvnnaylraala
Secondary Treatment: Acraiad Submu|l<1 Fliad	Population Served: £,000
FUm (Coatact Aaratioa)
INTLUENT WASTEWATER
SIGNIFICANT INDUSTRIES
Typical (Upaat)
Industry *
Fiovrata
(1060 gyd)
Problem Pollutants
Ave. Flow, rogd
% Indut trial
BOD$, mg/1
SS, mg/1
NH3, mg/1
0.2?.
20 ((o)
3 SO f)00)
200
60
Food Processor
Dental Office
SO
negl.
BOD, Flow suige*
Hg
Primary Clarifisri
Overflow Rate, gal/sf/day
Detention Time, hours
Effluent BODj, mg/1
Effluent SS, mg/1
fi«riiil«iy Clutfln
Overflo* Rate, gal/sf/day
Detention Time, hours
PLANT LOADING
Typical iOpaatJ	Coatact Bulaa
350 (1,000)
3.75 (1.25)
260
100
Typical (Op**0
450 (1,300)
2.8 (1.0)
Typical (UptMt)
Organic Loading (lb* BOD5/IOOO sf/iay)
Total Plant	2.8
First Stag*	8.4
Detention Time, hours	12
D.O. Level, mg/1	5-10
BOD5, tag/1
SS, mg/1
NH3, mg/1
PLANT PERFORMANCE
Permit Llait
30
30
10/20
Typical (O|m0
IS (400)
10 (50)
1 (60)
RAW
WA8TEWATER
COMMINUTOR
CLARIFIER
1*1 8TAQE
CONTACT
AERATION
BA8IN
INTERMEDIATE
CLARIFIER
~r
.J.
2nd 8TAQE
CONTACT
AERATION
BA8IN
INTERMEDIATE
CLARIFIER
r
.1
FINAL
EFFLUENT

3rd 8TAQE

CONTACT

AERATION

BASIN

1
~
FINAL
CLARIFIED


I	
PRIMARY
DIQE9TER
ECONDAR
DIGESTER
LAND APPLICATION
OR
SLUDQE DRYING BEDS
162

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ROCKY CREEK WATER POLLUTION CONTROL PLANT
Macon, Georgia
The Rocky Creek Water Pollution Control Plant (RCTP) treats an average of
12 mgd of wastewater, nearly half of which is contributed by industrial users.
40 percent of the total plant flow and 70 to 80 percent of the organic and solids
loading is contributed by one paper products manufacturer. Additional major
industrial users are an animal food processor, two food processors and a wood
preserving plant. The RCTP has been in substantial non-compliance of its
NPDES permit since coming on line in 1975, primarily because of variable
discharge of high strength organic waste. Although industrial wastes continue to
make up a large portion of the organic loading to the RCTP, the plant has not
experienced a NPDES permit violation in the last six months, coinciding with the
development and implementation of an industrial pretreatment program.
The RCTP utilizes the extended aeration activated sludge process to treat the
high-strength domestic/industrial wastewater. The large organic contribution of
the paper products manufacturer is nutrient deficient and requires phosphorus
and nitrogen addition for proper biological treatment. Despite the large organic
contribution and poor solids settling characteristics of this industrial
wastestream, it has not historically presented chronic treatment problems
because of its fairly consistent strength. Interferences identified at the RCTP
were primarily attributed to the other major industrial users, in particular the
animal food processor. Operations at the animal food processing plant were such
that periodic slugs of organic wastes w
-------
pretreatment improvements have been a major factor in the RCTP treatment
improvements, as the plant has gone from being overloaded and upset 50 percent
of the time to being upset twice a month at most. As a result, no NPDES permit
violations have been experienced since September, 1985.
164

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ROCKY CREEK WATER POLLUTION CONTROL PLANT
Macon, Georgia
Design Flow:
Secondary Treatment:
14 ogd
Fix tended Aeration
Activated Sludge
Location:	Central Georgia
Population Served: 75,000
INFLUENT WASTEWATER
SIGNIFICANT D'COS TRIES
Ave. Flow, mgd
"o Industrial
BOD$, mg/1
SS, mg/1
Typical (Upset)
12
50
150 (525)
230 (500)
Industry
Paper products
Animal Food processing
Food processing
V/ood preserving
Flowrate
(1000 gpd)
5000
7
130
9
Problem Pollutants
BOD, COD, SS
BOD, COD, SS
BOD.SS
oils, phenols
Aeration Basins
MCRT, days
MLSS, mg/1
Detention Time, hours
Return Flow, %
D.O. Level, mg/1
PLANT LOADING
Typical (Upset)	Secondary Clarifiers
20-40
3000
28
40-60
2.0 (4.0)
Overflow Rate, gal/sf/day
Detention Time, hours
Typical (Upset)
350
5.4
BOD<;, mg/1
SS, mg/1
PLANT PERFORMANCE
Permit Limit
30
75
Typical (Upset)
20 (80)
40 (150)
PAFER
MANUFACTURING
WASTEWATER
MUMCIPAL
AMO
INDUSTRIAL
WASTEWATER
I - I iNLfTWCNT
" 	ADDITION
:ipal t
3 —»Ol "
HAS
WAS
AERATION

BASINS

(2)

LARIFIERS
(3)
EFFLUENT
SLUDGE
HOLDING
TANK
BELT
FILTER
PRESSES
INCINERATION
AT LOCAL
PAPER MANUFACTURER
165

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CITY OF BALTIMORE, MARYLAND
The City of Baltimore owns and operates two wastewater treatment facilities,
Back River and Patapsco, with a combined volumetric flow rate of approxi-
mately 250 million gallons per day. The plants serve a combined population of
nearly 1.3 million, residing in the City and the Counties of Baltimore, Anne
Arundel and Howard. In accordance with the requirements of the General
Pretreatment Regulations (40 CFR Part 403) established by the U.S. EPA, the
City developed an extensive industrial waste control program to:
•	safeguard the public's health;
•	protect the wastewater systems and its employees; and
•	prevent deterioration of the receiving waters and lands.
The final report outlining the details of the industrial waste program identified
4,700 sources or potential sources of nondomestic wastewater, of which about
220 are EPA-designated categorical industries. A program of this magnitude
requires a significant committment in terms of personnel, equipment, office
space, and supplies. Annual operating costs are expected to exceed $2.5 million
by fiscal year 1989.
As part of an initial sampling effort, 35 nonconventional organic and inorganic
pollutants were identified in the influent to the two POTWs. Based on these
data, the following industrial discharge criteria were recommended or reiterated
in the industrial waste control program final report:

Limitations
Parameter
(mg/1, except pH)
PH
6.0
FOG
100
CN"
0.2
Cd
0.18
Cr (Total)
5
Cu
1.9
Pb
0.7
Hg
0.01
Ni
2.5
Zn
2.6
Explosivity
10% LEL
The report further specifies the need for continual monitoring of influent and
effluent toxicity through the use of Microtox and bioassay methods at both
treatment plants.
One of the more interesting aspects of the Baltimore program is the computer
coding of the sewer collection system. By knowing the constituents of each
industry's discharge, the flow rate and their location in the coded sewer system,
a contaminant discovered at either POTW can theoretically be traced back to its
potential source or sources. While such a backtracking program is of little use
for isolated discharges, it could prove beneficial in locating chronic dischargers
of specific compounds.
166

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BACK RIVER WASTEWATER TREATMENT PLANT
Baltimore, Maryland
The F?.ck River facility is hydraulically and organically overloaded, resulting in
etfluent BOD and SS consistently in excess of the 45 cng/1 interim limits. The
plant is currently undergoing a major renovation to replace the 30 acres of
trickling filter rock media with complete-mix activated sludge, along with
significant alteration and expansion of most process units. The renovation work
is in preparation for new NPDES Permit limits of 10/10 and 2 rag/1 (NH3), which
will require the addition of powdered activated carbon as an aid for nitrification.
Industrial flows to Back River total approximately 27 mgd, and are dominated by
metals and solvents in the discharge.
The primary source of metals in the system is from the 12 metal plating
operations identified by the industrial waste survey. The problem with the
metals content in the wastewater is that it restricts the ultimate disposal
options for the digested and dewatered sludge. When local limits were
calculated based on unrestricted distribution of the s'udge, the limits were
occasionally one-fourth of the achievable levels. Consequently, the City of
Baltimore opted for the less stringent 10,000 gpd electroplater standards for the
noncategorical industries. A compost facility now under construction is
expected to process 150 wet tons of the 450 tons produced each day, beginning in
March 1987. The metals content continues to remain a concern for this disposal
option.
The benefits of pretreatment for metals removal have been demonstrated at
Back River. An incinerator h^d been discharging 2 tons of fly ash per hour into
the collection system, which was high in metal content and was responsible for
90 percent of the cadmium in the POTW influent. Other wastewater containing
metals were from steel and automobile manufacturing. In each case, pretreat-
ment facilities have come on-line during the past year, with a measureable drop
in influent and sludge concentrations. The situation has improved to the point
where the City is reevaluating limits and granting exemptions to some industries
or d case-by-case basis.
The second major area of concern at the Back River plant stems from the large,
batch discharges of solvents, petroleum hydrocarbons and other toxic organics.
A 2:00 am discharge of ethylbenzene, xylene and toluene resulted in the
evacuation of the largest pump station and other buildings in town. The problem
was traced to a paint and chemicals manufacturer, who hits since improved its
in-house solvent recovery system. A similar evacuation resulted from a
4,000 gallon discharge of xylene by a waste hauler, which was traced to a
specific location in the collection system. Tetrachloroethylene has been
discovered and traced to dry cleaning operations. While such discharges have not
resulted in process inhibition at the plant, the health and safety issues and
potential for explosion are of serious concern to the City.
167

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BACK RJVTUl WASTEWATER TREATMENT PLANT
BALTIMORE, MARYLAND
Deiign Flow:
Secondary Treatment:
IPO mjd
Trickling Filters and Activated Sludge
INFLUENT WASTEWATER
SIGNIFICANT INDUSTRIES



Klowrate


Typical (Opset)
bdustry
(m(,d)
Problem Polkitaau
Avu, Flow, rage1
210 1235)
Metal Pilling (12)
0.18
Metals
% Industrial
15
Auto M tr.
1.5
Cr, Cu, Ni, Zn
BOD5l mg/1
230
Plant and Chemical
N/A
Ethyl benrene, toluene, xylene
SS, mg/1
190
Incinerator
n/a
Cd, Hg


Waste Hauitrs
n/a
Solvents, petroleum hydrocarbons
PLANT LOADING
Primary Clariftara
Overflow Rate, gal/sf/day
Detention Time, hour*
Effluent BOD5, rag/1
Effluent SS, mg/1
Secondary Clarifiers (A-o./T.PI
Orerflow Rate, gal/sf/day
Detention Time, hours
SVT, ml/gta
Typical (Opeet)
1,300 (1,500)
1.6
ieo
135
Typical (Opeet)
750/950
2.5/2.1
95
Aerattaa Castas
Ave. Flow, mgd
F/M, lba BOD5/lbs MLSS/day
MCRT, day»
MLSS, mg/1
Detention Time, hours
Return Flow, %
D.O. Level, mg/1
Trickltoc FUten
Ave. Flow, ragd
Hydraulic Loadings, ga/sf/d
Organic Loading, lb* BOD/1000 cf/d
Return Floe, W
Typical (Upset)
60
0.5
6.1
2,000
3.5
30-35
2-3
Typical (Upeet)
150 (170)
120 (136)
20
10
BOD;, mg/1
SS, mg/1
PLANT PERFORMANCE
Per rait Limit
45
45
Typical (Opeet)
70 («SJ
55 (70)
RAW WASTEWATER
BETHLEHEM 8TEEL
COOLING WATER
FINAL EFFLUENT
BAR SCREENS
AND
GRIT CHAMBERS
TRICKLING
FILTERS
(30 ACRES)
HUMU8
TANKS
(6)
CHLORINE
CONTACT
CHAMBERS
PRIMARY
LARIFIER3
(7)
_jqecondary\	}/
, CLARIFIERSf
I ^7
I
AERATION
BASINS
(2)
8LUDQE
DEGRITTERS
ELUTRIATION
/tanks\
GRAVITY
HICKENER)
(8)
HIGH RATE
SLUDGE
IGF8TEH
(«)
VACUUM
FILTER8
8LUDGE
TO
LANDFILL
168

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PATAPSCO WASTEWATER TREATMENT PLANT
Baltimore, Maryland
A 1981 EPA-sponsored project on biomonitoring of direct discharges rated the
Patapsco plant as having the most toxic effluent of those surveyed. Ironically,
the second most toxic discharge came from an agricultural chemicals manufac-
turer who, in 1983, ceased direct discharging and now sends their pretreated
wastewater to Patapsco. The high level of toxicity has resulted in the collection
of much bioassay, acute toxicity and respirometer data over the past four years.
Despite £\ high level of measured toxicity in the influent, the plant currently
meets its discharge limit for BOD and SS, indicating the ability of activated
sludge to acclimate to consistent levels of many organic compounds. Acute
toxicity data using a Beckman Microtox unit have been collected since November
1980. Some of the results of these analyses are shown on Figure C-3. The data
are on an inverse scale, with the lowest values indicating highest toxicity and
approximately 4?> percent corresponding to no toxic effect.
couaiuev
j£Ez IHFLUEHT
EEPUAfT
= trnue>fr
atillllilUllHiililiiti
inumiui
UillilliiiimntiUH
FIGURE C-3
MONTHLY ACUTE TOXICITY
(Courtesy G.H. Slattery, City of Baltimore)
Figure C-3 illustrates the toxic nature of the plant influent and effluent until
September 1982, at. which time the secondary treatment system went on-line.
The acclimation of the activated sludge improved effluent toxicity from
5 percent to 40 percent by December, where it remained until secondary
shutdown in February 1983. The effluent again became toxic until the secon-
daries were returned to service on June 15, providing clear evidence of the
detoxification capability of acclimated activated sludge.
169

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The attached data sheet indicates that Patapsco's noncompliance has resulted
from the discharge of excess phosphorus and an effluent pH below 6.5. The
phosphorus problem is being dealt with by installing A/O technology in the
oxygenation basins as a means of biological phosphorus removal. The low pH is
inherent in oxygen activated sludge systems, typically producing an effluent in
excess of 250 mg/1 of CO2 £Lnd a pH of 6.2. The problem can be corrected with
either chemical adjustment or post-aeration of the wastewater.
Although compliance with the NPDES Permit has been achieved for BOD and SS
at Patapsco, the plant flow is well below the 70 mgd design capacity. Toxic
inhibition is still present despite the improvement since 1983 (see Figure C-3).
Evidence of this inhibition is provided by the operating F/M of 0.3, which is
significantly less than the design value of 0.5. As a means of further improving
the situation, the State of Maryland included the following in the consent order
issued to the City in 1984:
•	install on-line toxicity monitoring of the plant influent
•	develop a toxics emergency response plan
•	enlarge the scope of the City sewer ordinance to include specifics on
toxicity and flammability for industrial effluents.
170

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PATAP5CO WASTEWATER TREATMEKT PLAKT
0ALTTMOHS* yAHYLAUD
Design Flow:	70
Secondary Tr«sto«ni: ActWetei Sludge 0*y§«*)
(NFLUKNT WASTWATKR
siGKmcAKT moos nun
Aft. Flow, mgd
% Industrie
BOD5, tng/l
SS. tng/l
TOX, t
Typical (UpMtJ
*Z
30
*65 :JiO)
3is '470)
IS
fete try
Chemical*
Metal Finishing
Flov?ai«
lag*)	ProfeWa Pollutaau
1.0	Insecticides, VolAtiles, phenols, mets
0.1)	pK, iolr«nti. metals
Priwary CUrtOan
Overflow Rate, gAl/sf/d«y
Oetentlon Tine, hour*
Effluent BOO$, mg/1
Effluent SS, tag/1
Seceeiery Clarito*
Overflow Rate. gal/s(/d*y
Detention Time, hours
SVI, ml/gm
PLAKT LOADING
Typical (Upaat)
l.ISO
l.S
1V0
i)
Typical (Opaat)
450
6 J
S0-7S
F/M, lbs BOO$/lbs MLSS/day
MCRT, days
MLSS, mg/1
Detention Time* hours
Return Flow. %
O.O. La*«l. mg/1
Typical (OpesU
0.3
10-IS
5,000
I
30
i-4
BOD$, mg/1
SS. reg/1
Totsl-P, mg/1
P«
tox, n
PLAKT PtftTORMAMCK
Parmlt Uait
30
30
*.0
6.S-«.S
Typical (OpMt)
18 (40)
dS <40)
1.5
6-6.S
40
RAW WASTEWATER
RA8
FINAL EFFLUENT
BAR SCREENS
PRIMARY
.
OXYGENATION
CLARIFIERS


BA8IN8
(3)


(4)
CONDARY
CLARIFIER
(4)
AIR
FLOTATION
THICKENERS

-------
CITY OF RAEFORD WASTEWATER TREATMENT PLANT
Raeford, North Carolina
The single most significant discharger to the Raeford Wastewater Treatment
Plant is a turkey processor who contributes 30 percent of the flow volume. Until
two years ago, the industry was discharging high concentrations of oil and grease
(1000 to 1200 mg/1) and large quantities cf feathers to the POTW. The problem
was so prevalent that flotation thickeners were used in lieu of primary clarifiers
in the original plant design during the 1950's. The problem had become
unmanageable from a plant operations perspective, hence the municipality
required the industry to install flotation on-site, thereby reducing the FOG level
to under 100 mg/1.
Raeford's pretreatment program defines a set of surchargeable and prohibitive
limits for five parameters:
Parameter	Surchargeable	Prohibitive
(mg/1)	(mg/1)
BOD	400	800
COD	1000	1600
TSS	350	600
TKN	40	80
FOG	--	100
If an industry's wastewater exceeds the limits defined in the first column during
their twice-per-month sampling, the sewer use fees are computed using mass-
based unit costs in addition to the flow-based rates. Should an industry discharge
wastewater concentrations in excess of the prohibitive values, a notice of
violation is issued and the industry is given 30 days to correct the problem prior
to the initiation of a five consecutive day sampling program. Consistent
noncompliance with these limits can result in a shut-off of services, but such a
drastic step has not been necessary for any of the three industries to date.
The turkey processor is routinely surcharged for their discharge, and at the time
of the site visit, were in violation of the prohibitive BOD limit. Their most
recent sampling analysis indicated the following concentrations (in mg/1):
BOD = 1000
COD = 1400
TSS 500
TKN = 70
The two other industries in town (a textile mill and a cosmetics manufacturer)
each contribute high BOD (600-800) and COD (1200-1400) wastewater to the
plant. Since Raeford is only at 2/3 hydraulic capacity, these organic loads do not
adversely affect the extended aeration process.
The cosmetics manufacturer has discharged low pH (1.5) wastewater to the plant
in the past, which can be toxic to the biological population in the activated
172

-------
sludge. Effluent BOD has climbed as high as 90 mg/1 on occasion. When
operations personnel became aware of the problem either by industry notifica-
tion or increased D.O. in the aeration basins, two procedures have been
implemented to mitigate the impact:
•	ilecycle portions of the aerobic digester to the plant influent, which
serves to dilute the low pH wastewater and return healthy organisms
to the aeration basins.
•	Add lime to the aeration basins to elevate the mixed liquor pH above
6.0.
The other major stumbling block to consistent compliance at Raeford had been
the high infiltration/inflow in the collection system. During the summer of 1985,
influent flows reached 4 mgd, resulting in a substantial washout of the biological
populations. Performing a television survey revealed that one of the two main
trunk lines to the plant (an 18" pipeline) had collapsed. By simply closing off the
collapsed line (the parallel 24" pipeline was adequate), the I/I flow increment was
reduced to 100,000 gpd.
173

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RAEFORD WASTEWATER TREATMENT PLANT
RAEFORD, NORTH CAROLINA
Design Flow:
Secondary Treatment:
3.0 ogd
Activated Shidge
(Extended Aeration)
Location:
Population Served:
South-Central TVorth Carolina
4500
INFLUENT WASTEWATER
SIGNIFICANT INDUSTRIES
Ave. Flow, mgd
°J Industrial
BOD5, rag/1
SS, mg/1
Typical (Upset)
2.0
60
300 (7SO)
200 (500)
Industry
Poultry
Textile
Cosmetics
Flowrate
(1000 gpd)
650
500
35
Problem Pollutant*
COD, BOD, TSS, TKN
COD, BOD
pH, COD, BOD
PLANT LOADING
Primary Flotation
Overflow Rate, gal/sf/day
Detention Time, hours
Secondary Clarifiers
Overflow Rate, gal/jf/day
Detention Time, hours
SVI, ml/gm
Typical (Up«et)
1050
1.5
Typical (Upset)
230
9
150-250
Aeration Basins
F/M, lbs BOD5/lbs MLSS/day
MCRT, days
MLSS, rag/1
Detention Time, hours
D.O. Level, rag/1
Typical (Upset)
0.1-0.15
5-10
3000
9.2
3-5
BOD5, rag/1
SS, mg/1
PLANT PERFORMANCE
Permit Limit
30
30
Typical (Upset)
25 (50)
25 (50)
RAW
WASTEWATER
RA8
tfCONOAh
PRIMAR
LOTATIO
TANKS
(2)
AERATION
/ WAS
ORIT
CHAMBER
AND
COMMINUTOR
CHLORINE
CONTACT
CHAMBERS
(3)
FINAL
EFFLUENT
SLUOOE
HOLOMQ
TANK
SLUOQE
DRYING
BEOS
(6)
174

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NEUSE RIVER WASTEWATER TREATMENT PLANT
Raleigh, North Carolina
In 1976, the 30 mgd Neuse River Wastewater Treatment Plant (NRWTP) went on-
line to replace the overloaded 16 mgd Walnut Creek plant. The City of Raleigh
has historically been a community that embraced industry. In the early 1960's,
influent BODs exceeded 300 mg/1 at Walnut Creek, with the effluent ranging
from 3 5 to 55 mg/1. Industries were encouraged to conserve and recycle wastes,
resulting in a 250 mg/1 BOD by the mid-1960's. The City's first Sewer Use
Ordinance was enacted in 1972, with continual modification to comply with
changes in the Federal regulations. The net effect is a current influent BOD
consistently below 200 mg/1, despite an industrial flow volume representing
25 percent of the plant flow.
The only significant industrial discharge to the V/alnut Creek plant was a large
electroplater whose occasional plating bath dumps were not prohibited by a
sewer use ordinance during the 1950's. Digester upsets (decreased gas produc-
tion) and high sludge metals content were traced to this particular industry.
Since dried sludge was being made available to the community for landscaping
purposes at the time, concern for the metals levels prompted adoption of a
proposed ordinance which directed the industry to construct a physical-chemical
pretreatment facility.
Two other metals-related industries have been responsible for high sludge metals
since the construction of the NF.WTP. In the current facility, wet sludge is land
applied to farmland adjacent to the POTW, hence metal content is critical. In
each case (an electroplater and a printed circuit board manufacturer), the
industries were discharging levels of Cr, Ni, Zn, Pb and Cu sometimes in excess
of 1,000 mg/1, with highly variable effluent pH, and were uncooperative in
dealing with the City of Raleigh. Fining the former industry $ 1,000, and
threatening the latter with same, provided sufficient incentive to install
pretreatment.
In the early 1980's a producer of amino acids for pharmaceuticals was attracted
to Raleigh and given the false impression they would be able to discharge slug
loads totaling 1,000 lbs of NH3 to the POTW each day. Fortunately, an activated
sludge system had been constructed for their facility for BOD reduction, which
possessed sufficient capacity to nitrify their wastewater to an ammonia
concentration of 50 mg/1. On one occasion, the NH3 levels became toxic to the
pretreatment activated sludge, resulting in a gradual loss of nitrification at the
POTW. Continual monitoring of alkalinity and NH3 allowed the City to preserve
their own nitrifier population while at the same time re-seeding the industry's
activated sludge with a viable nitrifier population for a speedy recovery. The
rapid response prevented the monthly effluent NII3 level:; from exceeding the
permit limit, despite high daily concentrations following the incident.
A dairy product manufacturer who cleans the stainless steel tanker trucks on-
site had previously discharged these wastes directly to the sewer. Average BODs
of 10,000 mg/1, with occasional values in the 30,000 to 40,000 mg/1 range were
typical. Working with the North Carolina State University, a vacuum recovery
175

-------
system was developed and a market identified for the collected whey waste. The
effluent; BOD now averages 2,000 mg/1, still resulting in a high surcharge
payment. The City of Raleigh has waived the prohibitive BOD limit of
1,500 mg/1 in this case because space limitations on the industry's property
prevents them from installing additional pretreatment.
An unusual case at the NRWTP was the discovery of high zinc levels (1,000 mg/1)
in the discharge from an office building with no manufacturing component.
Through discussions with maintenance personnel, the City of Raleigh discovered
that the contaminated discharges corresponded to floor stripping activities in the
building. It turns out that a Zn-based floor wax had been used, and stripping an
entire office building over the course of a week discharged enough Zn to the
POTW to significantly raise the level in their sludge.
The Raleigh plant is currently under construction to increase the hydraulic
capacity from 30 to 40 mgd, with an additional expansion to 60 mgd planned for
the near future (the schematic shown on the next page is for the 40 mgd
facility). The rapid growth of this community will continue to bring with it a
variety of challenging new industrial wastewaters with, in some cases, unpredict-
able impacts on the POTW. The Raleigh case study illustrates the need for
continuous survey and monitoring even after the implementation of a successful
industrial waste program in any dynamic population center.
176

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NEUSE RIVER WASTEWATER TREATMENT P'^ANT
RALEIGH, NORTH CAROLINA
Design Flow:
Secondary Treatment:
40 mgti
Activated Shidge
(Extended Aeration)
Location:
Population Served:
Central North Carolina
195,000
INFLUENT WASTEWATER
SIGNIFICANT INDUSTRIES
Ave. Flow, mgd
% Industrial
BOD^, mg/1
SS, mg/1
Typical (Upeet)
25
25
165 (350)
170 (500)
Induatry
Electroplate™, Metal
Finishers (5)
Pharmaceutical
Dairy
Snack Foods
Flowrate
(1000 gpd)
750
4C0
110
100
Problem Pollntaata
Cd, Cr, Cu, Nl, Pb, Zn, Cn", Fe, pH
NH3
BOD
BOD
PLANT LOADING
Primary Clarlfiera
Overflow Rate, gal/sf/day
Detention Time, hours
Secondary Clariilen
Overflow Rate, gal/sf/day
Detention Time, Hours
SVI, ml/gm
Effluent BOD5, mg/1
Effluent SS, mg/1
Effluent NH3, mg/1
BOD5, mg/1
SS, mg/1
NHj, mg/1
Typical (Upaet)
650
3.0
Typical (Opeat)
680
3.2
150-200
5
15
3
Aeration Bairtne
F/M, lbs BOD;/lbs MLSS/day
MCRT, day*
MLSS, mg/1
Detention Time, hours
Return Flow, %
D.O. Level, mg/1
Multi-Media Filter*
Hydraulic loading, gpm/sf
PLANT PERFORMANCE
Permit Limit
Summer Winter
6
30
3
12
30
6
Typical (Upaat)
3 (15)
4
1.5 (8)
Typical (Upeet)
.08-1.0
12-20
2500
15
50
2
Typical (Upeet)
2.5
RAW
WASTEWATER
BAR 8CREENS
AND
GRIT CHAMBER
EFFLUENT
RAS
PRIMARY
CLARIFIER8
(4)
WA8
—/centrifuge
DEWATERING
(12)
LAND
APPLICATION
/BLUDGE^
STORAGE
, TANKS ,
V<2> y
OAF
THICKENER
AEROBIC
DIGESTERS
(2)
MULTI-MEDIA
FILTERS
(0)
AERATION
BA8M8
(4)
CHLORINE
CONTACT
TANKS
177

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HORSE CREEK POLLUTION CONTROL FACILITY
North Augusta, South Carolina
The Horse Creek Pollution Control Facility (HCPCF) is a regional plant,
operated by the Aiken County Public Service Authority (ACPSA), treating a
predominantly industrial wastewater. Ninety five percent of the industrial
wasteload is contributed by several large textile mills and is characterized by
high COD, BOD, alkalinity and pH. Combined domestic/industrial influent
wastewater pH fluctuations of up to 2.5 units per day and alkalinity fluctuations
of up to 600 mg/1 per day caused inhibition of the biomass, poorly settling sludge
and caused effluent suspended solids permit violations. Since implementing a
pretreatment program and issuing industrial wastewater discharge permits, the
treatability of the industrial waste has improved, the result being that HCPCF
has been free of NPDES permit violations for over eight months.
Local textile processes include grading operations, finishing processes utilizing
dyes, and specialized textile chemical manufacturing. The textile wastewater is
highly caustic with alkalinity as high as 2400 mg/1, and pH exceeding 12.5. Prior
to pretreatment the combined industrial/domestic influent to the HCPCF had
the following characteristics:
Other distinguishing characteristics of the influent wastewater included the
extremely light nature of the suspended solids and a dark blue/black color,
typical of textile wastewater from washing and dying operations.
Prior to the summer of 1985, the textile industries employed a limited type of
pretreatment and flow equalization. This limited pretreatment and flow
equalization resulted in the previously mentioned plant influent pH fluctuations
of 2 to 2.5 units and alkalinity fluctuations of up to 600 mg/1 in a given day.
These fluctuations caused some inhibition of the biomass, but because the
hydraulic detention time in the aeration basins was in excess of 3.5 days,
effluent BOD was within the permit limit of 33 mg/1. These pH and alkalinity
fluctuations had their most detrimental effect on biomass settling
characteristics and solids carryover in the secondary clarifier often resulted,
lasting for 24-36 hours. During these episodes, filamentous organisms were
occasionally observed in the biomass. The solids carryover problem worsened in
the winter months when wastewater temperatures were lower, but chlorination
of the return activated sludge, the influent to the secondary clarifier and the
contents of the aeration basin was somewhat successful at improving settle-
ability. Despite this, the HCPCF still experienced effluent suspended solids
violations in 15 of the 19 months prior to September, 1985.
The State of South Carolina mandated that the ACPSA implement and enforce a
pretreatment program in the spring of 1984. The ACPSA responded by
pH
>11
Alkalinity
TSS
BOD
COD
360	mg/1
910	mg/1
1100	mg/1
210	mg/1
178

-------
developing such a program and issuing draft industrial wastewater discharge
permits. Final State approval came in May, 1985. As presently written, tne
industrial wastewater discharge permits are not restrictive, allowing BOD, COD
and alkalinity levels as high as 600 mg/1, 1300 mg/1 and 1500 mg/1, respectively.
However, the permits have caused the textile industries to make small, but
meaningful alterations to their wastewater discharge practices, resulting in
average plant influent pH levels dropping from 11-12 to 10 and alkalinity from
1100 mg/1 to 700 mg/1. More importantly, maximum daily influent pH
fluctuations have been reduced to 0.5 units or less. Figure C-4 shows the
magnitude of pH fluctuations both" before and after the implementation of
pretreatment. Simple modifications at textile facilities to process operations
and waste pumping schedules were typical of the changes that were necessary to
realize the described results. Because of the more stable wastewater discharge,
the HCPCF has realized more consistent plant operation and has not violated its
NPDES permit in over eight months.
Some of the textile dischargers do not currently meet the pH and alkalinity
limits of their industrial wastewater discharge permits and are under a
compliance schedule to do so. The facilities are installing pretreatment works
for caustic recovery that should significantly lower pH and alkalinity levels. Tne
HCPCF is also presently studying the addition of floating mixing units to
augment the turbine surface aerators in the aeration basins. To date, evidence
indicates that a more consistent secondary clarifier solids feed is achieved which
improves the quality of the secondary effluent.
I 1 ] M t ' I f « nil Q I« H « I It » n n U X )! M 1' N » K n
FIGURE C-4
HCPCF INFLUENT pH
179

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HORSE CREEK POLLUTION CONTROL FACELTTY
Aiksn County, South Carolina
Design Flow:
Secondary Treatment:
20 ragd
Extended Aeration
Activated Sludge
Location:
Population Sorved:
West-central South Carolina
70,000
IN FLUENT WASTEWATER
SIGNIFICANT INDUSTRIES
Ave. Flow, mgd
% Industrial
BOD5, mg/1
SS, mg/1
COD, mg/1
Alkalinity, m^/1
pH
Typical (Upset)
10.4
80
360
210
910
1100 (1600)
10-11 (12.5)
Industry
Textile
Textile chemicals
Flowrate
(1000 gpd)
8,400
300
Problem Pollutant*
COD, Alkalinity, pH
COD, pH
PLANT LOADING
Primary CLarifiers
Overflow Pate, gal/sf/day
Detention rime, hours
Secondary Clarifiers
Overflow Rate, gal/sf/day
Detention Time, hours
Typical (Upset)
300
4.J
Typical (Upset)
195
9.1
Aeration Basin*
F/M, lbs BOD5/lbs MLSS/day
M CRT, days
MLSS, mg/1
Detention Time, hours
Return Plow, %
D.O. Level, mg/1
Typical (Upset)
0.05-0.10
50-90
3800-4 500
92
40-60
1-3 (4)
BOD5, mg/1
SS, mg/1
COD, mg/1
pH
PLANT PERFORMANCE
Permit Limit
33
57
Typical (Upset)
15
40 185)
175
9 (10)
RAW
WASTEWATER
RA8
IECONDAR1
CLARIFIERS
1 (4) .
FINAL
EFFLUENT
PRIMARY \
ILARIFIERS
(4) j
8CREKN8 AND
AERATED GRIT
CHAMBERS (2)
IWAS
SLUDGE
STORAGE
TAMKS
„ (2)
VACUUM
FILTER8
(2) .
DECANT
TANK
LANDflLL
CHLORINE
CONTACT
CHAMEER
AERATION
BASINS
(6)
180

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NORTH SHORE SANITARY DISTRICT GURNEE PLANT
Gurnee, Illinois
The-Gurnee Plant of the Worth Shore Sanitary D;strict (NSSDGP) receives an
average daily wastewater flow of 12.4 mgd from a variety of sources. Those
sources include a major naval installation, domestic sewage discharges,
secondary effluent fro.n the District's North Chicago Sewage Treatment Plant,
and other industries which contribute 17 percent of the total flow.
Since .startup in 1976, the NSSDGP has experienced periodic failures at achieving
nitrification in the two-stage activated sludge system. The failures to achieve
nitrification to the ammonia levels of the District's NPDES effluent limits have
also, at times, been accompanied by general process upsets which have resulted
in effluent SS and BOD5 violations. One of the major industrial contributors to
the Gurnee Plant, a pharmaceutical manufacturer discharging an average flow of
750,000 gpd, has similarly experienced upsets of its own activated sludge
pretreatment system which have resulted in violations of the District's local
sewer use ordinance. It was initially believed that the observed interferences at
the NSSDGP were the result of the discharge of filamentous organisms and other
solids by the manufacturer. The initiation of in-plant solids control methods
(which significantly lessened the quantity of solids entering the industrial
wastewater pretreatment system) and pretreatment system upgrades did not,
however, eliminate interferences at the NSSDGP.
In 1980, District personnel began to suspect that the presence of a nitrification
inhibiting antibiotic, erythromycin, in the pharmaceutical wastewater was the
main cause of the process upsets at the NSSDGP. By 1983, test and control
bench-scale activated sludge reactors were placed in operation and the effects
of the pharmaceutical wastewater and erythromycin on the NSSDGP were
investigated. A bioassay test for the presence of erythromycin and other
nitrification inhibitors was also developed, along with a Direct Insertion
Probe/Mass Spectrometric technique for confirmation. The results of the bench-
scale testing indicated that the presence of soluble and/or solid constituents of
the pretreated pharmaceutical wastewater inhibited nitrification and, at high
levels, could completely suppress nitrification. Additionally, it was found that
although erythromycin inhibited nitrification, acclimation to low concentrations
of erythromycin could occur in the absence of extreme concentration
fluctuations.
During January of 1984, an observed average industrial pretreatment effluent
erythromycin concentration of 53 tng/1 with mass loading fluctuations of greater
than two orders of magnitude eomplete'y inhibited nitrification in the Gurnee
Plant, The resulting BOD5 and SS concentrations were as high as 26 mg/1 and
67 mg/1, respectively, Lower concentrations of erythromycin in the absence of
such strong concentration fluctuations did not interfere with the performance < f
the Gurnee PJant during August of 1984, with average effluent BOD5 and SS
concentrations ui 11 mg/1 and 8 mg/1, respectively, and effluent ammonia
concentrations ranging from 0.4 mg/1 to 1.5 mg/1 as N. Experience at the
Gurnee Plant and with the bench-scale test systems has also indicated that a lag
period of two to three muan cell residence times is required before the effects
181

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of erythromycin on the activated sludge process become apparent. Erythromycin
also was found to disrupt the settling of the first-stage carbonaceous organisms.
Measures undertaken by District personnel to lessen the effect of the
pharmaceutical discharge on plant performance have included:
•	The addition of inorganic coagulants to aid primary clarifier
performance;
•	the addition of polymer to the first-stage activated sludge system,
•	daily bioassays of industrial wastewaters for the presence of
inhibiting substances; and
•	the development of an ordinance governing the discharge of
erythromycin to the NSSDGP.
Since passage of the ordinance in November, 1985, in which the discharge limits
of erythromycin were established, the NSSDGP has substantially been in
compliance with its NPDES permit and ammonia levels of 0.25 rag/1 to 1 mg/1 as
N have been consistently achieved.
182

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NORTH SHORE SANITARY DISTRICT GORNEK PLANT
GURNEK, ILUONOB
Design Flow;
Secondary Treatment:
13.8 mgd
Actlvttad Shadge
(Two-Stage, Modlfled-Contact)
Location:
Population Served:
Northeastern Illinois
65,000
INFLUENT WASTEWATER
SIGNIFICANT INDUSTRIES
Ave. Flow, mgd
% Industrial
BOD5, mg/1
SS, mg/1
NHj, mg/1
Typical (Upset)
12.4
37
140
180
15
Industry
Pharmaceutical
Electroplating
Chemical
Nonferrous Metals
Military Installation
Flowrate
(1000 gjM)
750
100
170
90
3,500
Problem Pollutant*
Antibiotics, SS
Cu, CN
Organic*
W
pH
PLANT LOADING
Primary Clariflers
Overflow Rate, gal/sf/day
Detention Time, hours
Effluent BOD$, mg/1
Effluent SS, mg/1
First Stage Clitifim
Overflow Rate, gal/sf/day
Detention Time, hours
Second Stag* Clariflers
Overflow Rate, gal/sf/day
Detention Time, hours
Typical (Upeet)
695
2.7
100
100
Typical (Upaet)
780
2.5
Typical (upaet)
645
3.1
First Stag* Aeration —
F/M, lbs BODj/lbi MLVSS/day
MCRT, days
MLSS, mg/1
Detention Time, hours
Return Flow, %
D.O. Level, mg/1
Second Stage Aeration
F/M, lbs NH3-N/lbs MLVSS/day
MCRT, days
MLSS, mg/1
Detention Time, hours
Return Flow, %
D.O. Levels, mg/1
Typical (Upset)
0.95
7
3000
4.2
25
2.5
Typical (Upset)
0.07
13
3500
5.8
50
2.5
BOD5, mg/1
SS, mg/1
NHj, mg/1 (summer)
PLANT PERFORMANCE
Permit Limit
10
12
1.5
Typical (Upaet)
S
5
0.5
(17)
(23)
(15)
RAW
WA8TE WATER
COAGULANT
J

POLYMER
PRIMARY
CLARIFIERS

1ST STAGE
AERATION


(4)


BASINS
(e)


1
1
}rA8 \


1
I

1ST 8TAGE


|

CLARIFIER8
_

1

(4)

1
1
I
1
(WAS
1
L.	
*

2ND 8TAGE
AERATION
BASIN8
(«)
Jl
RA8
WAS
2ND 8TAQE
CLARIFIERS
(4)
FINAL
EFFLUENT
SAND
FILTERS
AERATION
TANKS
CHLORINE
CONTACT
CHAMBER
I /GRAVITY
I r fHICKENERi
(2)
STORAGE'
TANK
TO
CENTRALIZED
'dewatering
FACILITY
183

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SANITARY DISTRICT OF ROCKFORD SEWAGE TREATMENT PLANT
Rockford, Illinois
The Sanitary District of Rockford operates the Rockford Sewage Treatment
Plant (SDRSTP) which serves a population of 240,000 and more than
400 industries. Forty-five metal finishers, two dairies, three food processing
plants, several large machine tool manufacturers, twenty-five permitted batch
waste haulers, a contract waste treatment facility, and several paint
manufacturing plants are among the major sources of industrial wastewater.
Industrial wastewater contributes 45 percent of the daily average treatment
plant flow of 35 mgd. Over the years, the District has experienced sludge
disposal problems and isolated excursions of their NPDES permit discharge limits
that were related to the industrial discharges to the POTW.
Upon passage of the Resource Conservation and Recovery Act in 1980, the
District's thickened sludge was found to be classified as hazardous because of the
cadmium content. The local industrial discharge limits, which had been in
existence for several years, were therefore tightened for cadmium from 2.0 mg/1
down to 0.9 mg/1 and sewer use surcharges were applied. The result was that
from initial sludge cadmium concentrations of 800 rag/kg in 1980, a level of
50 mg/kg was achieved by 1984. The addition of excess amounts of limn prior to
vacuum filtration was practiced as an interim method of rendering the vacuum
filter cake nonhazardous (EP-Toxicity method) and therefore acceptable for ' u.nd
filling. This was done to allow contributing industries time to install
pretreatment systems and come into compliance with the lower local discharge
limits. Presently, the District is investigating the feasibility of land application
for ultimate disposal of sludge.
Isolated incidents of batch discharges of concentrated manufacturing process
solutions to the POTW have resulted in process upsets and effluent discharge
violations. A batch discharge of a nickel plating solution to the POTW in 1981
resulted in a treatment system upset and effluent BOD and SS concentrations of
38 mg/1 and 34 mg/1, respectively. Upon notification of the incident by the
industry, the POTW personnel attempted to isolate the contaminated incoming
wastewater and confine the nickel slug within the primary clarifiers. However,
most of the nickel had passed through the primary treatment units by the time of
notification and the process recovered after only a few days. Prior to the nickel
spill incident the POTW was subject to a shock load of cyanide in 1977. Upon the
arrival of an unknown amount of cyanide at the POTW, it was found to be
difficult to maintain a chlorine residual after the disinfection of the secondary
effluent. Subsequent analyses revealed effluent cyanide concentrations as high
as 1.06 mg/1 which were in violation of the NPDES permitted limits of 0.2 mg/1
CN~. Extensive industrial site visits, sampling and interviews were undertaken,
but the source of the spill was not verified. The most intensive shock level of
cyanide may have occurred in 1970 when the raw wastewater cyanide
concentration increased from less than 0.5 rrg/1 to 34 mg/1 in a period of one
hour. Although such shock load interferences as experienced by the SDRSTP are
isolated events, they have not been uncommon at the SDRSTP. For example, in
1979 there were 36 NPDES permit violations of the concentrations or mass
loadings of cyanide, chromium and zinc.
184

-------
The District's pretreatment program has been characterized by the
establishment of effective local limits for the discharge of metals and toxic
substances, an extensive industrial monitoring program, the development of spill
notification procedures, and cooperation between the District and the local
industries. Over the past ten to fifteen years, 34 industrial pretreatment
systems have been installed and the metal finishing industry has reduced its
discharge by more than one-half to about 3 mgd. The overall result has been a
reduction of the number toxic, noncompatible-pollutant NPDES violations
from the historical numbers of excursions, such as 36 in 1979, to zero in 1984.
185

-------
ROCK FORD SANITARY DISTRICT SEWAGE TREATMENT PLANT
ROCK FORD, ILLINOIS
Design Flow:
Secondary Treatment:
60 mti
Acttoata4 SU|i
(Ccanitloul)
Location:	NortWra mtaola
Population Served: 240,000
INFLUENT WASTEWATER
SIGNIFICANT INDUSTRIES
A»e. Flow, mgd
% Industrial
BOD5, mg/1
SS, tng/I
Typical (Opaat)
35
45
164
245
Metal Finishing
Metal Plating
Dairy
Flowrate
(1000 cpd)
725
587
470
Prablta PolkitiaU
Zn, Ca, Cd. Nl, Cr
CN, Cu, Zd
BOD5, SS
PLANT LOADING
Primary Civilian
Overflow Rate, gal/tf/day
Detention Time, hours
Effluent BOD5, mg/1
Effluent SS, mg/1
Sccoidary ClariAan
Overflow Rate, gal/if/day
Detention Time, hour*
SVT, ml/gin
Typical (TJpaet)
563
3.4
110
77
Typical fDpaet)
486
3.6
125
Aeratioa Baitm
F/M, lbs BODj/lbs MLSS/day
MCRT, days
MLSS, mg/1
Detention Time, hours
Return Flow, %
D.O. Level, mg/1
Typical (Upast)
0.2
14
2500
4.8
33
1.5
BOD;, mg/1
SS, mg/1
PLANT PERFORMANCE
Permit Limit
20
25
Typical (Opaat)
20
13
RAW
WASTEWATER
RE-AERATION
TANKS
(•)
RAS
AERATION
BASINS
(•)
SECONDARY
CLARIFIERS
(1»
	r
CHLORINE
CONTACT
CHAMBER
FINAL
EFFLUENT
GRAVITY
THICKENERS*
TORAOS
TANKS >
TO
_ CENTRALIZED
0EWATERN4Q
FACILITY
186

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LAKE MILLS WASTEWATER TREATMENT PLANT
I-ake Mills, Iowa
The Lake Mills Wastewater Treatment Plant (LMWTP) serves a community of
2,200 persons in North-Central Iowa* Approximately 37 percent of the average
flow of 0.3 5 mgd is industrial in nature and arises from the two major industries
within the community. A printed cr uit board manufacturer discharges an
average flow of 80,000 gpd which contains copper, lead, chromium, nickel and
zinc. The other major manufacturing concern discharges 50,000 gpd to the
POTW. Presently, there are no problem pollutants associated with this second
discharge.
The circuit board manufacturer experienced growth during the past decade which
resulted in increased discharges of copper, lead find other metals to the POTW.
In 1980, the copper and lead levels in the anaerobically digested sludge were
observed to be 4,300 mg/kg and 1,100 mg/kg of dried sludge, respectively. The
State then intervened and halted the LMWTP's prior disposal practice of
spreading the sludge on agricultural land. Because of a lack of a disposal option,
the sludge solids were allowed to accumulate within the single-stage digester of
the treatment works with digester supernatant recirculation to the head of the
facility. A one-time disposal of 90,000 gal of sludge to a landfill was allowed by
the State in 1982 after which solids were again held within the treatment works.
Prior to the receipt of a high-rate land application permit in the fall of 1984, t'.ie
sludge held in the digester contained as much as 16,000 mg/kg of copper.
•
A program of monitoring the circuit board manufacturer's discharge was
initiated in May of 1984 at which time the average copper and lead
concentrations being discharged to the POTW were 2 to 4 mg/1 and 0.4 to
1.2 mg/1, respectfully. The municipality and the manufacturer entered into a
pretreatment agreement which resulted in the installation of an ion exchange
and precipitation metals removal system. The pretreatment program has
resulted in lower metals loading to the POTW. Monthly average copper and lead
concentrations of 2.64 mg/1 and 0.3 mg/1 have been observed in the pretreated
industrial discharge. Current municipal regulations require pretreatment
discharge limits for metals which are consistent with those of 40 CFR 433 and
fines are imposed for each incidence of noncompliance.
As a result of the reduced metals loading to the POTW and of the ability to
dispose of digested sludge solids on a regular basis, the metals content of the
digested sludge has been reduced to the vicinity of 5100 mg/kg as was observed
in December of 1985.
During the periods for which sludge disposal was not practiced on a regular basis,
the overall plant performance was found to deteriorate. From average effluent
BOD5 concentrations of 29 mg/1 and 24 mg/1 in 1982 and 1983, respectively, a
yearly average effluent BOD5 of 40 mg/1 was observed for 1984. The effluent
BOD5 for the last quarter of 1985 averaged 22 mg/1. Although the results axe
not conclusive, it is believed by some that the poor overall plant performance of
recent years was the result of high organic and solids loadings (because of
digestor supernatant recycling) to the trickling filter and possible metal toxicity.
187

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LAKE MILLS WASTEWATER TREATMENT PLANT
LAKE MILLS, IOWA
Design Flow.	0.36 (1.1 hydraulic)	Location:	North Iowa
Secondary Treatment: Trickling Filter	Population Served: 2,200
(High Rate; Rock Media)
INFLUENT WASTEWATER
SIGNIFICANT INDUSTRIES
Ave. Flow, rogd
% Industrial
BOD$, rag/1
SS, rag/1
Typical (Upaet)
0.35
37
460
SO
Industry
Electroplating
Automotive Products
Flow rate
(1000 gpd)
80
50
Problem Pollutants
Cu, Pb, Cr, Ni, Zn
None
Primary Clarifiers
Overflow Rate, gal/sf/day
Detention Tiroe, hours
PLANT LOADING
Typical (Upset)	Trickling Filter
680
3.7
Typical (Upaet)
Organic Loading, lb BOD5/IOOO cf/day	47
Recirculation, %	123
Covered; Rock Media
Secondary Clarifiers
Overflow Rate, gal/sf/day
Detention Time, hours
Typical (Upaet)
500
2.3
Polishing Pood
Detention Time, days
Effluent BOD5, mg/1
Effluent BODj, rag/1
Typical (Upaet)
54
22 (40)
38 (64)
PLANT PERFORMANCE
Permit Limit	Typical (Upaet)
BOD5, rag/1 30	22 (40)
SS, rag/1 30	38(64)
NH3 mg/1 (Summer) 10	3 (4)
RECIRCULATION
SECONDARY
CLARIFIERS
(2)
RAW _
WASTEWATER
~ FINAL
EFFLUENT
LAND
APPLICATION
188

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MARSHALLTOWN WATER POLLUTION CONTROL PLANT
Marshalltown, Iowa
The Marshalltown Water Pollution Control Plant (MWPCP) experienced brief periods
of effluent BOD limitation violations p.-ior to 1982. The violations were the
combined result of high hydraulic loadings to the plant because of infiltration
and inflow and excessive BOD5 loadings which exceeded the capacity of the
treatment facilities. Whereas the MWPCP was designed for average daily and
peak hydraulic flows of 5.5 and 8.0 mgd, respectively, extreme wet weather
flows as great as 20 mgd were experienced. Flows in excess of 8 mgd were found
to result in an excessive loss of microorganisms from the activated sludge
system and it was necessary to provide only primary treatment for the total flow
and bypass secondary treatment for the excess wastewater flows. At the same
time that high hydraulic loadings were experienced, BOD5 loads averaging
14,000 lb BODs/day were contributed by a meat packing facility. The average
BOD5 of the industrial loadings represented 65 percent of the average
wastewater strength and maximum industrial contributions of j3,000 lb
BOD5/day were observed. Additionally, excessive discharges of grease (up to
15,000 lb/day) had also occurred. Prior to 1982, the industrial wastewater in
question was not receiving pretreatment. The effluent limitation violations
arose during periods of high hydraulic and high organic loadings at which times
plant effluent (secondary effluent plus bypassed primary effluent) BOD5
concentrations of up to 170 mg/1 occurred.
A significant upgrade of the MWPCP wai .ompleted in 1982. Included in the
upgrade were additional treatment units for increased hydraulic capacity, the
installation of a jet aeration system which substantially increased the organic
loading capacity, and new sludge handling facilities. The typical data presented
in the following table characterize the MWPCP as it now exists. The reported
upset parameter values represent the process conditions prior to the 1982 plant
upgrade and during periods of high hydraulic and organic loadings.
In conjunction with expansion of the capacity of the MWPCP, ths meat packing
industrial concern instituted a waste minimization/pretreatment program, upon
State intervention, which has reduced the average organic load of the industrial
wastewater to 8000 lb BODs/day with a solids loading of 4000 lb/day. Livestock
holding pen runoff is now subject to primary sedimentation. A blood collection
and drying system was installed. The remaining wastewaters are strained and
subjected to dissolved air flotation for grease removal. Although other
wastewater pretreatment alternatives were proposed, the selected system was
economically advantageous because of the potential for protein and grease
recovery.
A total of 37 industries were identified in a city-wide industrial survey. Of the
37 industries, 20 were classified as sources of industrial wastewater and of these,
six are monitored regularly. One categorical electroplater is subject to a
compliance schedule. The total industrial wastewater flow averages 1.2 mgd.
The present industrial pretreatment program consists of sampling and analysis of
the industrial discharges, as conducted by MWPCP personnel, and close co-
operation between the municipality and the various industries. There have been
189

-------
no recent events of noncompliance on behalf of the MWPCP because of industrial
waste discharges. There have, however, been several instances of potential
interferences to MWPCP operation because of industrial waste discharges. For
example, elevated but noninterfering concentrations of lead :n the treatment
plant influent were traced to the batch dumping of a lead-acetate solution used
in the manufacture of latex paint. The lead was voluntarily eliminated from the
wastewater initially by reuse and more recently by process substitution.
190

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MARSHALLTOWN WATER POLLUTION CONTROL PLANT
MARSIIALLTOWN, IOWA
Design Flow:
Secondary Treatment:
7.5 mgd (11.0 hydraulic)
Activated Sludge
(Conventional)
Location:
Populate' Served:
Central Io«
27,000
INFLUENT WASTEWATER
SIGNIFICANT INDUSTRIES
Ave. Flow, ragd
% Industrial
BOD5, mg/1
SS, mg/1
Typical (Ur*e»!
o.5 (> £)
18
400 (900)
370
Industry
Meat Packing
Electroplating
Metal Finishing
Paint Manufacturing
Flowrate
(1000 gpdj
800
30
18
1
Problem Pollutants
BOD5, grease
Cu, Ni, Cr
Zn
Hg
PLANT LOADING
Primary Clarifiers
Overflow Rate, gal/sf/day
Detention Ti;ne, hours
Effluent BOD5, ro^/l
Effluent SS, mg/1
typical (Upset)
1000 (> 14501
1.25 (< 0.86)
320 (700)
185
Aeration
F/M, lbs BOD5/lbs MLSS/day
MCKT, days
MLSS, mg/1
Detention Time, hours
D.O. Level, mg/1
Typical (Up»et)
0.4
13
2900
7 (4.8)
1.0
Secondary Clarifiers
Overflow Rate, gal/sf/day
Detention Time, hours
Typical (Upset)
450 (650)
2.2 (1.5)
PLANT PERFORMANCE
Permit Limit	Typical (Upset)
BOD5, mg/1 25	<25 (170)
SS, mg/1 25	<25
RAW
WASTEWATER
FINAL
EFFLUENT
RA8
COMMINUTORS
CHLOHM8
CONTACT
CHAMBER
| WAS
D.A.F.
THICKENER
ARAVITV
THICKENERS
„ LAND
APPLICATION
191

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SIOUX CITY WASTE TREATMENT PLANT (SCWTP)
Sioux City, Iowa
The Sioux City Waste Treatment Plant (SCWTP) treats a combined industrial and
municipal wastewater average flow of 13.!> mgd and discharge." to the Missouri
River. More than 140 industries were identified by an industrial survey as
potential sources of wastewater. Of these, four are categorical metai finishing
or electroplating industries and, as of recently, eleven industries contributed
significantly to the suspended solids, BOD and o;,I and grease discharged to the
SCWTP. Although the total volumetric load of the industrial wastewater is
typically less than 10 percen: of the total ilow, the industrial organic loads to
the plant account for greater than 50 percen* of the observed loads.
The SCWTP has experiencad two separate instances in which industrial
discharges have interfered with normal plant operations. Isolated slug loads of,
zinc were experienced by the SCWTP in March and again in April of 1984.
Levels as high as 16 mg/1 Zn were observed in the treatment plant influent and
both slug-load incidences resulted in an upset of the activated sludge process and
violations of the NPDES discharge limits. Effluent BOD5 concentrations
exceeded 60 mg/1 and effluent suspended solids concentrations in excess of
200 mg/i were observed. The investigation of the first slug load of zinc was
somewhat hampered by the lack of in-house capabilities for metals analysis and
the first indication of a contamination problem was the pr<-:.css upset itself.
Upon confirmation of the nature of the interference, a temporary system for the
continuous addition of lime to the primary clarifiers, which would result in the
precipitation of subsequent slug loads of zinc, was installed and operated until
such time that frequent and periodic monitoring and analysis of the influent for
metals could be performed at the SCWTP.
The source of the metal discharge was identified from the City's industrial use
survey and from samples of wastewater and solids collected at specific locations
in the wastewater collection system. In addition to the process upsets, sludge
held in storage lagoons at the facilities became contaminated with zinc and plans
to dispose of several years accumulation of sludge by spreading on agricultural
land were modified upon receipt of special permitting from the State.
In 1?85, a pharmaceutical extractor came on line discharging batches of high
strength waste without pretreatment. The strength of the waste ranged from
10,000 to 100,000 mg EOD5/I and the waste contained high levels of salt and
sulfite. The average BOD5 of the waste vas 3 5,000 mg/1 and the batch dumps
represented 45 percent of the total organic load to the SCWTP. The activated
sludge process was severely overloaded and intermittent depressions of the D.O.
level occurred. It was possible to operate the activated sludge process to
accommodate the severe organic loads, but the process would again be upset
during the weekends when the pharmaceutical extractor was not discharging
waste and the organic loads were reduced. Throughout 198% the SCWTP
experienced severe violations of their NPDES BOD5 and suspended solids
discharge limits. Frequent violations of the pharmaceutical extractor's
discharge permit occurred with respect to the organic strength and daily mass
loading of the waste. The industrial user was placed on a compliance schedule
192

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and continued violations of the discharge permit necessitated actions that would
result in flow equalization and reductions in the levels of methyl mercaptan.
sulfite and sulfide. Presently, all batch waste dumps are transported by bulk to
the SCWTP where they are meterec', by SCWTP personnel, into the plant influent
under controlled conditions.
The upset conditions presented in the following table represent conditions
related to the discharge of the pharmaceutical wastewater. The reported upset
conditions represent averages for several months of 1985 whereas the typical
conditions were based on data for 1984 which spanned nine months and included
those months in which the slug loads of zinc were experienced.
193

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•MUWA Vl<
tlWlB 1 IVbA * M »<« i ( U/U1
SIOOX CITY, IOWA
Design Flow:	10 mgd
Secondary Treatment: Activated Stodge
(Conotlaaal)
Location:	Northveat Iowa
Population Served: 235,000
INFLUENT WASTEWATER
SIGNIFICANT INDUSTRIES
Typical (Dpaet)
Industry
FTowrate
(1000 gpd)
Problem PoilataaU
Ave. Flow, mgd
Vt Industrial
BOD;, mg/1
SS, mg/1
13.5
7
380 (612)
550 (630)
Meat Processing	1,000	BOD;, oil and grease, SS
Pharmaceutical	70	BOD;, methyl mecaptan, sulfite
Metal Finishing	20	Zn, Cr, Ni
PLANT LOADING
Primary CUriWsn
Overflow Rate, ga]/sf/day
Detention Time, hours
Effluent BOD$, mg/1
Effluent SS, mg/1
Clarificn
Orerflaw Rate, gal/sf/day
Detention Time, hours
SVI, ml/go
Tfpic.il (Upaet)
577
2.9
220 (370)
240 (235)
Typical (Dpaet)
722
1
150
Aeratfcoa Bail—
F/M, lbs BOD;/]bs MLSS/d«y
MCRT, days
MLSS, mg/1
Detention Time, hours
Return Flow, %
D.O. Level, mg/1
Typical (DpeeO
0.2 (0.3)
10
2500
15
40
2.5
BOD;, mg/1
SS, mg/1
PLANT PERFORMANCE
Permit Limit
30
30
Typical (Upawt)
34 (37)
33 (45)
RAW
WASTfcWATER
BAR SCREENS
AND
QRIT CHANNELS
FINAL
EFFLUENT
RA8
WAS
PRE-AERATION
TANKS
(4)
8LUDQE LAQOON8
MQE8TER8
V <4> )
PRIMARY
CLARIFIER8
(4)
CHLORINE
CONTACT
TANKS
(2)
AERATION
BASINS
(4)
194

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NEWARK WASTEWATER TREATMENT PLANT (NWTP)
Newark, Ohio
The NWTP had been in substantial non-compliance of their 1981 NPDES Permit
from the beginning of 1983 until the middle of 1984. This consistent violation
had resulted primarily from increased waste loads on the POTW from industrial
sources. Between 1979 and 1984, the percentage of industrial wastewater
increased from 12 to 22 percent by volume, with influent BOD increasing from
220 to 330 mg/1, while suspended solids increased from 200 to 350 mg/1. To
complicate the non-compliance problem, four separate ammonia discharge
episodes occurred from August to October, 1983 which resulted in the killing of
80,000 fish in the Licking River. The fish kill precipitated the submission of
Verified Complaints to the Ohio EPA on August 6, 1984 by the Black Hand Gorge
Preservation Association, against the City of Newark find the NWTP. Following
an investigation, the Ohio EPA issued Director's Final Findings and Orders,
specifying a compliance schedule and interim discharge limits until a planned
facility upgrade is completed by July 1988.
There are two significant industrial contributors to the NWTP who were also
issued Director's Final Findings and Orders in May, 1985. A fiberglas insulation
manufacturer had been discharging high concentrations of phenol (2-5 mg/1) and
NH3 (up to 500 mg/1), with occasional spills of formaldehyde into the collection
system. The activated sludge bacteria were acclimated to the phenol in the
wastewater, but were susceptible to shock loadings of the NH3 and formalde-
hyde. Fortunately, the industry was responsive to the problems of the NWTP,
and instituted a corrective program to:
•	conserve and recycle plant flows, which have reduced their discharge
by 60 percent (from 1.22 to 0 45 mgd) over the past two years;
•	construct an aerated equalization basin to air-strip phenol and
distribute diurnal fluctuations; and
•	construct a pretreatment facility for their landfill leachate.
The POTW is still subject to occasionally high NH3 loads from the industry,
which is currently the only identifiable cause of interference problems in the
plant. The municipality and industry continue to work cooperatively to resolve
this problem through the implementation of a spill prevention and control
program. Additionally, the renovated POTW will use some of the existing
clarifier tankage for off-line storage in the event of future spill episodes.
A second major industry is a dairy which came on-line in 1976. Initially, the
dairy stored their whey waste in a silo and typically bled it into the sewer
system. The discharge was high in both BOD and suspended solids (2,000 mg/1),
and would occasionally be batch discharged to the POTW, resulting in a shock
loading to the activated sludge. The industry has since installed a reverse
osmosis treatment system for the whey waste which has reduced the solids and
organic loading to the plant.
195

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The only categorical industry that currently discharges to NWTP is an electro-
plater who constructed a metals removal system in conformance with federal
pretreatment regulations. In the past, dewatered sludge had been applied to corn
fields adjacent to the plant property. However, when heavy metals were
detected in seven of ten monitoring wells, Newark began hauling liquid sludge
off-site. The planned facility upgrade will include installation of belt filter
presses, so that the existing sludge (with acceptable levels of heavy metals) can
once again be dewatered and more economically hauled off-site to farm land.
The replacement of coarse bubble aerators with fine bubble equipment in mid-
1984	significantly improved BOD removals and the NWTP compliance record.
Nitrification, which did not occur previously, now takes place in the last two
aeration basins. The only incident of non-compliance with the interim permit in
1985	resulted from an NH3 discharge from the fiberglass manufacturer. In this
case, even though the average monthly BOD measured 29 mg/1, the carbonaceous
component was less than 10 mg/1. The final permit will have a more stringent
NH3 requirement and will also designate CBOD as a permitted parameter.
196

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NEWARK WASTEWATER TREATMENT PLANT
NEWARK, OHIO
Design Flow:
Secondary Treatment:
S.O (12.0 Hydraulic) mgd
Activated 9ud|>
(Conventional)
Location:
Population Served:
Caatral Ohio
41,000
INFLUENT WASTEWATER
SIGNIFICANT INDUSTRIES
Ave. Flow, mgd
% Industrial
BOD5, mg/1
SS, mg/1
NH3, mg/1
Typical (Opaet)
7.5
15
305 (450)
360 (550)
35 (60)
Industry
Fiberglass
Dairy
Electroplater
Klowrate
(1000 gpd)
450
ZZ3
97
Problem Pollutants
Phenol, NH3, Formaldehyde
BOD, Phosphorus, SS
Cr, Cd, Pb, Ni, Zn, Cyanide
Primary Clariflan
Overflow Rate, gal/>(/day
Detention Time, hours
Effluent 30D$, mg/1
Effluent SS, mg/1
Secondary Clariflan
Overflow Rate, gal/sf/day
Detention Time, hours
SVT, ml/gm
Typical (Upaat)
560
3.2
194 (280)
147 (218)
Typical (Upaat)
500
3.7
150 (350)
PLANT LOADING
Aeration Basins
F/M, lbs BOD5/lbs MLSS/day
MCRT, days
MLSS, mg/1
Detention Time, hours
Return Flow, %
D.O. Level, mg/1
Typical (Upaat)
0.25 (0.4)
5-6
2,000
6.3
50
2.0
PLANT PERFORMANCE
Permit Limit	Typical (UpaaO
BOD5, mg/1 20	15 (60)
SS, mg/1 40	15 (95)
NH3, mg/1 (Summer) 25	15 (30)
RAW
WASTEWATER
FINAL
EFFLUENT
BAR
SCREENS
WA8
RAS |
AERATED
QRIT
CHAMBER
ANAEROBIC
0IQE8TER8
(3)
LIQUID
SLUDGE
HAULING
SECONDARY
CLARIFIER8
PRIMARY
CL ARIFIERS
CHLORINE
CONTACT
CHAMBER
AERATION
BASIN8
197

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9lst AVENUE WASTEWATER TREATMENT PLANT
Phoenix, Arizona
The 91st Avenue Wastewater Treatment Plant (NAWTP) provides secondary
treatment for a major portion of the wastewater flow from the greater Phoenix
area. The most significant industrial contributors to the NAWTP are electro-
platers and metal finishers—their principal pollutants being cadmium, copper,
chromium and cyanide. Because of acclimation, the effect of these metals has
not been measureably detrimental to the NAWTP's biological system, although
occasionally Cu and Cd pass through the plant to the effluent in concentrations
violating permit limits of 0.05 mg/1 and 0.01 mg/1, respectively. Most of the
metals entering the NAWTP partition to the sludge, which prevented land
disposal as an option in the past. An industrial pretreatment program, developed
over the last four years and approved in July, 1985, has markedly decreased the
amount of metals entering the NAWTP and consequently the pass through and
sludge disposal problems have been nearly eliminated.
Prior to industrial pretreatment, influent copper and cadmium concentrations at
the NAWTP were approximately 0.25-0.32 mg/1 and 0.03 mg/1, respectively. Six
to eight percent of the influent wastewater was industrial, nearly all of which
originated at metal finishing and plating operations. Typical copper discharge
concentrations for some circuit board manufacturers were as high as 40- 60 mg/1.
Heavy metals removal from the wastestream was generally greater than
75-80 percent; copper and cadmium concentrations in the digested sludge were
measured at 2,020 mg/1 and 44 mg/1, respectively in 1983. The concentrations
precluded disposal of the sludge on agricultural lands. Fortunately for the City
of Phoenix, at about the time these metal concentrations were discovered, a
precious metals processor became interested in utilizing the sludge and for five
years incinerated all the sludge produced by the NAWTP, recovered the metal
content and disposed of the ash to a landfill. Despite the high metals
partitioning to the sludge, pass through of copper and cadmium in excess of
permitted effluent concentrations was not uncommon. In response, an industrial
pretreatment program was developed in 1982 to decrease the influent metal
concentrations to the NAWTP. Industries were involved by the City in the
program development, and the City of Phoenix offered technical knowledge,
short of design, to the industries trying to meet the reduced metal discharge
limits. Prior to the implementation of a pretreatment program, most industries
had no pretreatment other than flow equalization, and many installed pretreat-
ment works in order to meet the new copper and cadmium discharge limits of
4.5 mg/1 and 0.1 mg/1, respectively. A pretreatment and metal recovery system
at one large circuit board manufacturer cost in excess of $ 2.5 million.
As a result of the pretreatment program, typical treatment plant influent copper
and cadmium concentrations have been cut to 0.15 mg/1 and 0.012 mg/1, respec-
tively, and treatment plant Cu and Cd effluent limits are generally not
exceeded. With the reduction in influent wastewater metals concentrations a
corresponding reduction in the sludge metal concentrations occurred and it was
no longer profitable for the precious metal recovery firm to continue processing
and disposing of the NAWTP sludge. However, the metal concentrations were
198

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reduced to a level where the sludge was acceptable as a soil conditioner, and as a
result another company has begun marketing the dried sludge commercially.
Industries are presently self-monitoring their discharge, with the City sampling
most industries at least eight times per year as well. The monitoring frequency
is increased when an industry is in non-compliance with its permit. Figure C-5
shows the change in influent metals levels at the 91st Avenue Plant between
1982 and 1985.
91st Ave. Influent Metals
)M2
91st Ave. Influent Metals
O.JA
0.2ft H
0 16
O.OB
9 1st Ave. Influent Metals
1
9 1st Ave. Influent Metals
0.J4
0 2®
0 29
0 24
0 12

FIGURE C-5
91st AVENUE INFLUENT METALS
199

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91»t AVENUE WASTEWATER TREATMENT PLANT
PHOENIX, ARIZONA
Design Flow:
Secondary Treatment:
120 mgd
Activated Sludge
(Complete Mis)
Location:
Population Served:
Soutli Central Arisoaa
1,100,000
INFLUENT WASTEWATER
SIGNIFICANT INDUSTRIES
Ave. Flow, mgd
¥* Industrial
BOD5, mg/1
SS, rag/1
Cd, mg/1
Cu, mg/1
Typical
140
7
220
150
0.012 (0.03)a
0.15 (0.3)a
India try
Electroplaters and
Metal Finishers
Flowrate
(mgd)
1C
Problem Pollutants
Cd, Cr, Cu, CN"
PLANT LOADING
Primary Clarlfiera
Overflow Rate, gal/if/day
Detention Time, hours
Effluent BOD5, rag/1
Effluent SS, mp/1
Secondary ClariFieri
Overflow Rate, gal/sf/day
Detention Time, hours
Typical
1,050
1.8
180
80
Typical
700
2.2
Aeration Ba»in»
N'CRT, days
MLSS, mg/1
Detention Time, hour*
Return Flow, %
D.O. Level, mg/1
Typical
1-2
500-800
5
35
2.0
PLANT PERFORMANCE
Permit Limit	Typical
BOD5, rag/1 30	16
SS, mg/1 30	12
Cd, mg/1 0.01	0.005 (0.03)«
Cu, mg/1 0.05	0.03 (0.10)a
- Before Pretreatment
CHLORINE
CONTACT
BASINS
AERATION
BASINS
(4)
PRIMARY
SECONDARY
CLARIFIERS
(4)
RAW «
WASTE
WATER
O)
BAR SCREENS
AND
GRIT CHAMBERS
(2)
DAF
SLUDOE
LAOOONO
"•"-8LUOOE
TO LANDFILL
200

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TOLLESON WASTEWATER TREATMENT PLANT
Tolleson, Arizona
The Tolleson Wastewater Treatment Plant (TWTP) is a two stage trickling filter
plant that treats a predominantly domestic wastewater from Phoenix, Arizona
suburbs. The successful operation of the TWTP is dependent on the one
significant industrial contributor to the treatment plant, a meatpacker who
processes 1,000 to 1,400 head of beef per day. The treatment plant typically
discharges effluent with BOD5 and SS levels both below 10 mg/1, but has been
upset on occasion to the point of effluent permit non-compliance when it
receives slug loads of blood and grease from the meatpacker with BOD5 and SS
levels of up to 2,200 mg/1 and 1,375 mg/1, respectively. Upset frequency and
severity have been reduced in recent years through improved industrial waste
monitoring and treatment process monitoring, respectively.
The influent to the TWTP could be typified as medium to high-strength municipal
wastewater with average BOD5 and SS levels being 275 mg/1 and 225 mg/1,
respectively. Approximately 25 to 30 percent of the organic and solids loading is
contributed by the meatpacker on an average basis at levels of 1,100-1,600 mg/1
BOD5 and 700-1,400 mg/1 SS, for wastewater flows of 0.8-1.0 mgd. In general,
the domestic/industrial waste stream can be treated to well within
30/30 discharge limits, but in the past the meatpacker would upset the treatment
process by slug discharging blood or some other high strength organic slaughter
by-product. Prior to 1982, these upset conditions would last for several days and
result in weekly and monthly effluent r-spended solids of 30-40 mg/1, in violation
of permit limits.
Treatment upsets have diminished in frequency and intensity since 1982 for two
reasons:
•	A legal contract with the meatpacker limits flow to 0.8 mgd, BOD5
to 10,675 lbs per day (1,600 mg/1) and SS to 6,670 lbs per day
(1,000 mg/1), and provides for fines or disconnection if these limits
are exceeded, and
•	Improved treatment plant process monitoring has enabled operators
to better detect, and thus act on, a potentially upsetting condition.
The contract with the meat packer attempts to prevent waste blood from being
stored for more than about eight hours at a time before discharging to the sewer.
Prior practice resulted in blood being held back for up to a week at a time before
being discharged all at once.
Primarily through trial and error, the operators of the TWTP have established
several operating parameters that help them in detecting upset conditions in the
plant. The depth of sludge in the primary clarifiers is monitored closely; a high
or rapidly increasing sludge depth is indicative of upset conditions and is caused
by the high solids content of the meatpacking waste. The mixed liquor in the
solids contact basin following the second trickling filter is monitored closely as
well, with levels above 500 mg/1 signaling possible problems. Mixed liquor
201

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concentrations of 1,500 mg/1 generally result in effluent suspended solids of
greater than 30 mg/1. To remedy am upset condition, primary sludge pumping
rates are manually increased above their normal levels to reduce the solids
inventory and prevent escape in the effluent.
As a result of all industrial wastewater interference prevention work, the TWTP
has gone from experiencing periodic effluent permit vilolations to experiencing
infrequent upsets, seldom resulting in NPDES Permit violations.
202

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TOLLESON WASTEWATER TREATMENT PLANT
TOUJSON, ARIZONA
Detign Flow:	8.3 mgd	Location:	South Central Arlso
Secondary Treatment: 2 Stage Triciltng Filter	Population Served: 65,000
with Solid* Contact
INFLUENT WASTEWATER
SIGNIFICANT D40USTRIBS
Ave. Flow, mgd
% Industrial
BOD$, mg/1
SS, mg/1
Typical (Upeet)
7.4
14
275 (340)
225 (280)
Industry
Meat Packer
Flowrate
(1000 gpdJ
1000
Problem Pollutants
BOD, SS
Primary Clarifiers
Overflow Rate, gal/sf/day
Detention Time, hour*
Effluent BOD5, mg/1
Effluent SS, mg/1
Intermediate Clarifiers
Overflow Rate, gal/if/day
Detention Time, hours
Effluent BOD;, mg/1
Effluent SS, mg/1
PLANT LOADING
Typical (Upset)	Flrat Stage Trickliag FUt«r
860
1.9
160
95
Typical (Upeet)
735
2.4
30
30
Hydraulic Loading, gal/sf/day
Organic Loading, lbi BODj/1000 cf/day
Recirculation, %
Second Stags Trickling Filter
Hydraulic Loading, gal/if/day
Recirculation, %
Typical
1,000
45
100
Typical
500
100
Secondary Clariflers
Overflow Rate, gal/»f/day
Detention Time, hour*
Typical (Upaet)
480
7.4
BOD;, mg/1
SS, mg/1
PLANT PERFORMANCE
Permit Limit
30
30
Typical (Opset)
9 (25)
9 (35)
RAW WASTEWATER
EFFLUENT TO
TURF IRRIGATION
BAR SCREEN AND
GRIT CHAMBER
INTERMEDIATE
, CLARIFIER8 (2)
1ST STAGE
TRICKLING
. FILTER j
2NO STAGE
TRICKLING
t FILTERS
v<2> y
, W8
fSECONDAR'
iCLARIFIER!
V <2) ,
PRIMARY
CLARIFIER8
(3)
SOLIDS
CONTACT
CHANNEL
SLUDGE
DRYING BED8
SLUOGE TO TURF FARM
203

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VICTOR VALLEY REGIONAL WATER RECLAMATION PLANT (WRWRP)
Victorville, California
The WRWRP has, since 1981, experienced periodic activated sludge upsets
accompanied by chronic aeration basin and anaerobic digester foaming problems,
believed to be caused by solvent-type chemicals. During this same period, COD
levels up to three times the permitted effluent limit of 15 mg/1 have also been
discharged. Initial efforts to discern the cause of the upsets and foaming, and
document the source of the pollutants were limited to visual and olfactory
investigation of the treatment facilities and sewer interceptors. Recently, more
thorough attempts to document the upsets (wastewater sampling and laboratory
analyses) have resulted in positive identification of the upsetting pollutants and
source, and have established the framework for the correction of the problems.
Start-up of the WRWRP, treating primarily domestic wastewater, was com-
pleted in June, 1981 with the connection of an Air Force Base (AFB) sewer
interceptor. The AFB ccntributas both domestic and industrial wastewater with
vehicle and plane washing, jet fueling and paint stripping facilities producing the
largest industrial flows. The WRWRP began experiencing effluent COD permit
violations, aeration basin foaming and occasional biological upsets shortly after
the connection of the AFB sewer interceptor. The foaming and upset problems
continued into 1985 without significant efforts made to document the cause or
source of the problems. Chemical addition and variation of the food to
microorganism ratio and the mixed liquor suspended solids were unsuccessful at
mitigating the foaming problems. Periodically, strong solvent or oil odors were
detected at the treatment facility and in the influent wastewater, coinciding
with two-fold effluent BOD and COD increases. Attempts to trace the odor of
the pollutants to the source generally implicated the AFB, but no further action
to substantiate the AFB as the pollutant source was immediately initiated.
Decisive steps were taken to document and correct the problems following a
February, 1985 "spill" of pollutants with a strong solvent smell into the treat-
ment plant. Wastewater samples were immediately taken at the plant influent,
the AFB interceptor and the sewer above the AFB connection. Laboratory
analyse- showed significant concentrations of a number of pollutants in both the
plant intiuent and in the AFB wastewater. Other similar events were sampled
and analyzed from July through September, 1985. The ranges of concentrations
detected for six compounds during the July-September upset sampling are shown
below:
Compound

WRWRP Influent
(ug/1)
AFB Effluent
(ug/D
Chloroform
Methylene Chloride
Toluene
m, p-Xylene
Phenol
bis (2-Ethylhexyl) phthalate
15-23
11-43
11-29
11-19
11-12
39-210
10-55
11-1600
43-400
F6-320
11-230
17-830
"04

-------
During upset conditions, effluent COD values doubled to approximately 3 5 mg/1
and turbidity levels exceeded 2 NTTJ, also ir> violation of effluent limits.
Methylene chloride concentrations as high as 68 mg/1 were measured in the
February analysis of the AFB effluent.
The documented upsets resulted in discussions between VVRWRP and the AFB
officials, with the district requesting that base practices causing the discharge
of inhibitory levels of contaminants be stopped. The AFB pretreatment
currently consists only of poorly operated oil-water separation units.
Despite the VVRWRP-AFB dialog, the treatment plant continues to experience
foaming problems and violate effluent COD limits, presumably because of the
AFB discharges. A formal "Cease and Desist" order was issued to the AFB in
September, 1985. As of this writing, a wastewater sampling and analysis
program is being completed by the AFB as the first step of a negotiated
agreement to correct the sewer discharge/treatment plant interference problem.
205

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»h-iub val.l.e.1 ncuiunAt «Aie,K KiULAMAiiun ruim
V1CTORVILLE, CALIFORNIA
Design Flow:
Secondary Treatment:
4.8 mgd
Activated Sluice
(Modified Step Feed)
Location:
Population Served:
Southcentral California
40,000
INFLUENT WASTEWATER
SIGNIFICANT INDUSTRIES
Avi. Flow, mgd
Industrial
BODn, rap/1
CCC, raj/1
SS, mg/I
Typical (Upset)
3.8
15
^00 (300)
350 !i0W
200 (440)
Industry
Military Base
Cement Mfr.
Restaurants
Flovrate
(1000 gpd)
850
110
Problem Pollutant*
Methylene chloride; Toluene; ra, p-Xylene
cement dust
fats and grease
PLANT LOADING
Primary Clarifiera
Typical (Upaet)
Overflow Rate, gal/sf/day
Detention Time, hours
972
1.71
Secondary Clarifiera
Typical (Upaet)
Overflow Rate, gal/sf/day
Detention Time, hours
533
4.71
Aeration Basins
Typical (Upaet)
F/M, lbs BODc/lbs MLSS/day
MCRT, days
MLSS, iirg/1
Detention Time, hours
Return Flow, *'o
D.O. Level, ras/l
0.3-0.4
5-10
2000
7.3
50-100
0.5-1.0
Plemira rliter*
Filtration Rate, gal/sf/min
Typical
2.54
PLANT PERFORMANCE
Permit Limit	Typical (Upset)
BOD5, mg/1
COD, mg/1
SS, ing/1
Turbidity, NTU
10
15
10
2
3-4 (6-7)
20 (35)
1-3 (1-3)
1 (2-5)
a*w
WASTIWATtft
FMAL IFriUtNT
OAf
CKKNCI
206

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DTICK CREEK SEWAGE TREATMENT PLANT, PAW PAW SEWAGE
TREATMENT PLANT
Denison, Texas
The Duck Creek Sewage Treatment Plant (DCSTP) is one of four small treatment
facilities owned, operated and maintained by the City of Denison, Texas. The
plant is located on the far north end of town, adjacent to the Red River. The
Paw Paw Sewage Treatment Plant (PPSTP), located on the east end of Denison,
is one the older sewage treatment facilities operated by the City.
The DCSTP and PPSTP had consistently failed to n.eet NPDES discharge
standards for BOD and suspended solids prior to 1978. A state court order
required Denison to monitor the industrial waste discharges from the four largest
industries in town on a 5 day per week basis. Two of these industries were
deleted from the court order when they initiated their own pretreatment
program and constructed pretreatment facilities. In 1985, Denison was issued an
EPA Administrative Order to implement a pretreatment program. A revised
City Sewer Ordinance was approved by the City Council on January 6, 1986.
The four largest industries in Denison are all food processors; of these, the two
that do not pretreat are the major source of industrial interferences at the
PPSTP. These two industries are a food oil refinery, and an oily-type food
processor (marqarine, salad oil, etc.). These two facilities have a common
discharge pump station and have the capability tc flow by gravity to the DCSTP.
The influent to the DCSTP has a BOD5 concentration of 400-500 mg/1 and a TS3
concentration ranging from 50-300 mg/1. Concentrations of fats, oils and grease
(FOG) cause problems at the DCSTP, particularly when one of those industries
releases a batch dump of their waste. Apparently, such an incident had occurred
on Monday, February 3, 1986, and the residual effects of this batch dump were
noted at the plant during the JMM site visit on Tuesday, February 4, 1986. Major
effects included clogging of the bar screen, and scum on the secondary clarifier.
There would also have been a thick grease layer on the oxidation ditch, but a
previous day's rain (4 inches in 6 hours) had caused the headworks to overflow,
and a substantial quantity of grease was noted on the ground adjacent to the
oxidation ditch. Due to the overloaded condition and lack of parallel units at
this plant, there are no process control alternatives for responding to these batch
discharges other than bypassing the bar screen and running the influent
comminutor. The DCSTP is in compliance with the NPDES discharge permit
about 65 percent of the time. When it is in an upset condition, effluent BOD and
TSS concentrations exceed 140 mg/1 and 200 mg/1, respectively, on the average.
The most significant industrial flows are processed through the PPSTP. This
plant receives upwards of 400,000 gpd of industrial waste with a BOD ranging
from 1,200 to 2,000 mg/1, TSS range of 400 to 650 mg/1 and FOG of 300 to
400 mg/1. The FOG is noted to be extremely high. In addition, the flow
contributed by these industries is only a City estimate, based on their f'.ow
measurements wh 2n tha flow from these industries has been diverted to the
DCSTP due to pump station problems. The two industries in question claim total
combined discharge of 140,000 gpd, based on pump station wet well size and
207

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pump cycling. There is no flow meter on this pump station, nor have water
consumption records been used to gage discharge flow due to uncertainties
regarding in-plant consumptive use values.
At the time of the administrative order, the City was asked to guarantee NPDES
discharge permit compliance for the PPSTP. To accomplish this, a chemical
addition system was added to feed cationic polymer and liquid alum into the
PPSTP influent flow. The result of this program is the reduction of effluent
BOD and TSS from averages around 35 mg/1 each, to less than 20 mg/1 each. The
cost of this chemical addition program is approximately $ 8,000 per month,
essentially due to the cost of alum ($137/ton, 8 gpd feed rate) and polymer
($1.85/lb, 6.1 gpd feed rate). Due to mechanical problems at this plant, one of
two trickling filters is out of service, and has been so for over two months,
awaiting arrival of replacement parts from the manufacturer.
Other problems noted at PPSTP are the grease accumluation, and foam due to
detergents. The grease can accumulate on the bar screen, primary clarifier, or
chlorine contact tanks, and can plug the trickling filter distributor ports.
Several ports were noted to be plugged during the site visit, and the wastewater
superintendent noted that if the ports awe cleaned, they generally plug up again
within less than one hour's time. The greatest accumulation of grease was noted
on the chlorine contact tanks' water surface. The City has received permission
from the EPA to periodically pump these tanks down to remove accumulated
grease. Foaming was noted at the downstream side of the mechanical grit
chamber, and the influent splitter box to the chlorine contact tanks. The oil and
grease do not appear to significantly impact effluent quality.
In mid-1985, the City hired a consultant to examine their wastewater treatment
system and recommend any necessary modifications. The consultant recom-
mended a new 2.5 mgd Trickling Filter/Activated Sludge plant to be constructed
by late 1987, replacing both the Paw Paw and Duck Creek Sewage Treatment
Plants.
208

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PAW PAW SEWAGE TREATMENT PLANT
DENISON, TEXAS
Design Flow:
Secondary Ttutaoit!
2.S mgd
Trickling Filte
Location:	North Texas
Population Served: 5,000
INFLUENT WASTEWATER
Ave. Flow, mgd
To Industrial
BOD5, mg/1
SS, mg/1
Typical (Dpaet)
1
50
480
440
Industry
Food Processor
Food Oil Processor
SIGNIFICANT INDUSTRIES
Flowrate
(1000 gpd)
24
200
Problem Poltotanta
BOD, TSS, FOG
BOD, TSS, FOG
Primary Ciarifier
Overflow Rate, gal/sf/day
Detention Time, hours
Effluent BOD5, mg/1
Effluent SS, mg/1
PLANT LOADING
Typical (dpaet)	Trickling Filte
230
7
100
80
Loading lbs BODs/1,000 cu ft
Return Flow, %
Typical (Dpaet)
5 (15)
400
Secondary Clarifier*
Overflow Rate, gal/sf/day
Detention Time, hours
Typical (Upaet)
350
4.5
BOD5, mg/1
SS, mg/1
PLANT PERFORMANCE
Permit Limit
20
20
Typical (Dpaet)
18 (34)
12 (39)
RAW
WASTEWATER
PRIMARY
CLARIFIER
FINAL
CLARIFIER
ICKLINQ
FILTERS
(2)
BAR SCREEN
FINAL
EFFLUENT
CHLORt NATION
PRIMARY
DIGESTER
Z09

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DUCK CREEK SEWAGE TREATMENT PLANT
DENISON, TEXAS
Design Flow:
Secondary Treatment:
1.0 mgd
Activated Stodge (Oxidation
Ditch Ext. Aeration)
Location:
Population Served:
North Texas
7,000
INFLUENT WASTEWATER
Ave. Flow, mgd
% Industrial
BOD5, mg/1
SS, mg/1
Typical (Upaet)
1.2
50
320
330
.industry
Food Processor
Food Processor
Wood Preserver
SIGNIFICANT INDUSTRIES
Problem Pollutants
Flowrate
(1000 gpd)
39
4 (up to 30)
30
BOD, 04G
BOD, TSS, O & G
Creosote
PLANT LOADING
Primary Clarifiers	Aeration R"t—	Typical (Opaet)
No Primary Clarifiers F/M, lbs BODj/lbs MLSS/day	0.13
MCRT, days	7.7
MLSS, mg/1	1,800
Detention Time, hours	26
Return Flow, Vo	50
D.O. Level, mg/1	1.5 - 2.0
Secondary Clarifiers	Typical (Upaat)
Overflow Rate, gal/sf/dey	' 0
Detention Time, hours	2.
PLANT PERFORMANCE
Permit Limit	Typical (Opaet)
BOD5, mg/1 20	35 (140)
SS, mg/1 20	45 (200)
OXIDATION
DITCH
RAW _
WASTEWATER
» FINAL
EFFLUENT
WAS
8LUDOE DRYING
SED8
210

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PARE WASTEWATER TREATMENT PLANT
Paris, Texas
The Paris Wastewater Treatment Plant (PWTP) was constructed in 1972 to serve
the municipal and industrial needs of this north Texas community. The City
fathers had adopted a policy of bringing industries into the City by making
generous allowances in the areas of municipal taxes and utilities. There were no
industrial waste discharge requirements for industries in Paris until 1983, when
the EPA issued an administrative order for the City to improve discharges from
the PWTP such that they would comply with their NPDES permit. The City
Utilities Department staff then set up a comprehensive 90 day industrial
discharge monitoring program to determine which industrial discharges were
responsible for the treatment plant overloading. The plant was designed to treat
a maximum BOD loading of 8,000 lbs/day, but was receiving an average of
10,000 lbs/day with peaks of over 15,000 lbs/day. The sampling program
revealed that greater than 53 percent of the influent BOD loading was attribut-
able to four large industries.
The Utilities Department developed an industrial sewer use ordinance which was
put into effect by the City Council in late 1983. This ordinance is strictly
enforced by the Utilities Department. In the first year, over $ 350,000 in
surcharge fees were collected. This has subsequently dropped to about $ 190,000
per year. The Utilities Department required the four largest industries to
install permanent recording flow meters and refrigerated composite samplers. A
second set of industries was required to install flow meters, flow monitors, and
manholes for the City to take samples. A third group of industries was required
to install a Parshall Flume, with the City making periodic flow measurements
c.nd taking samples. Finally, the smallest industrial dischargers were required to
install an effluent manhole from which the City could withdraw samples. The
result of the ordinance and strict enforcement of the surcharge program is that
the /najority of the large industries have all installed their own pretreatment
systems. Two have their own NPDES permits, and one of these operates a 6 mgd
overland flow treatment system.
Of the major industries in Paris, most are food processors or paper products
manufacturers. One of the four largest, however, is a categorical (metal
finishing) industry. This discharger still contributes an average of 40-50 rag/1 of
ammonia, 30 mg/1 of copper and 17 mg/1 of zinc into the PWTP. The City has
worked with this industry to develop a timetable whereby it will reduce its
ammonia discharge to 30 mg/1 and its heavy metals discharge to EPA categorical
standards by June 1986. The presence of heavy metals in the sludge limits sludge
disposal to non-agricultural lands.
The PWTP now receives an average of 6,000 lbs/day of BOD5, which it can easily
handle with its existing facilities. Occasional slug loads of up to 27,000 lbs/day
have been received at the PWTP. These are typically handled by increasing the
MCRT and MLSS concentrations. The most recent episode of a slug of high
strength waste did not have any adverse effects on the PWTP.
211

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The City is starting construction of an upgrade to the PWTP which is scheduled
to be completed by December, 1986. The major feature of the upgrading will be
the addition of an 80 foot diameter by 15 foot deep plastic media roughing filter
ahead of the activated sludge system. This is being paid for by the largest
industry in town, and will increase the design BOD5 loading for the PWTP to
15,000 lbs/day.
One other major feature of the City's ordinance is their refusal to take wastes
which are high in oil and grease content. The PWTP has no primary clarifiers
and can therefore not easily remove oily wastes from the flow stream. All local
restaurants are required to have a grease trap to remove grease from their waste
flows before discharge to the City sewer system.
At the core of the City's successful pretreatrnent program is their willingness to
enforce the City ordinance, and their laboratory. The City has its own
water/wastewater laboratory which produces duplicate analyses of all samples.
The City provides effluent analyses of industrial discharges to industries at no
charge to that industry. The City data are consistently accurate, and match
quarterly EPA sampling data.
212

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PARIS WASTEWATER TREATMENT PLANT
PARIS, TEXAS
D*d|i Flowi	6 u|i	LMittai	North T<
Secondary Drutaatt Actlnlad SW|i	Population Sou »«di 26,000
(CHbdatiaa Dltcfc Est
Aeration)
INFLUENT WASTEWATER
SIGNIFICANT INDUSTRIES
A»e. Flow, mgd
% Industrial
8OD5, mg/1
SS, mg/1
Typical (Upaat)
4
1$
ZOO (1,000)
zoo
Food Proceaior
Metal Finiaher
Flowrate
(1000 IP*}
Z10
100
ProblaB PoUutaat*
BODs, TSS
N»3, Cu, Zo
PLANT LOADING
Priauur Clarifim
No Primary Claritieri
Secondary ClarlflaH
Overflow Rate, gal 'sf/day
Detention Time, hcun
SVI, ml/gm
Typical (Upaat)
800
2.5
1Z0 (160)
Aaratioo Bariaa
F/M, Ibi BODj/lbi MLSS/day
MCRT, days
MLSS, mg/1
Detentioa Tine, hour*
Return Flow, %
D.O. Level, mg/1
Typical (OpaaO
0.09 (0.33)
16 (ZO)
2,500 (3,200)
22.5
SO
0.5
PLANT PERFORMANCE
Permit Limit	Typical (Opaat)
BOD$, ®g/l 20	10 (30)
SS, mg/1 20	10 (30)
RAW
WA8TEWATER
LARIFIER
(2)
FINAL
EFFLUENT
AERATED
GRIT
CHAMBER
rAEROBIC*
DIGESTER
GRAVITY
HCKENEI
- LAND
APPLICATION
CHLORINE
CONTACT
CHAMBER
AERATION
8A8IN8
(2)
213

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POST OAK WASTEWATER TREATMENT PLANT
Sherman, Texas
The Post Oak Wastewater Treatment Plant (POWTP) treats all municipal and
industrial wastewater generated in the City of Sherman, Texas. In 1982, the
City was issued an EPA Administrative Order to institute a pretreatment
program. With the assistance of the Director of Utilities for the City of Paris, a
sewer use ordinance was developed and passed by the City Council in 1983.
In addition to the implementation of the sewer use ordinance, the POWTP was
upgraded in 1983 with the addition of an activated sludge system following the
existing trickling filters. As soon as this system was placec' on-line, the plant
effluent concentrations of BOD and TSS dropped from over 30 for each, to less
than 13 for each. Prior to the addition of the activated sludge system, the
POWTP was never able to respond to industrial discharges due to a lack of
control on the trickling filter recycle pumps. The POWTP now consistently
meets its discharge permit requirements.
The implementation of the sewer use ordinance led to the installation of
pretreatment plants at all five of the City's major industries. One of these, a
coffee processor, utilizes an overland flow system during dry weather, and
discharges to the POWTP during wet weather. Wet weather flows to the POTW
typically peak in excess of 17 mgd.
Another industry of interest is an edible oil - food processor. This industry has
installed a pH adjustment/heat treatment system to remove fats, oils and grease
from its discharge, but still discharges in excess of 2,000 mg/1 BOD, 600 rag/1
TSS and 600 mg/1 FOG to the POWTP. This user pays approximately $ 250,000
per year in surcharge fees. Influent FOG to the POWTP averages 40-50 mg/1 due
to dilution, and does not cause amy significant process problems.
The one major categorical industry is a chromium plater who discharges in
excess of 1 mgd to the POWTP. This user has installed a chromium reduction,
pH adjustment, metal hydroxide precipitation pretreatment facility to reduce its
surcharge liability. Dewatered metal hydroxide sludge is trucked to Houston for
appropriate disposal.
214

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POST OAK WASTEWATER TREATMENT PLANT
SHERMAN, TEXAS
Design Flow:
Secondary Treatment:
8 mgd
Two-stage; IVickling Filte
Activated Sludge
Locations	North Texas
rg/	Population Served? 30,000
INFLUENT WASTEWATER
SIGNIFICANT INDUSTRIES
Ave. Flow, mgd
% Industrial
BOP5, rag/1
SS, cog/1
Typical (Upaet)
6.5
60
200
lfO
ladua try
Food Processor
First Aid Products Mfr.
Coffee Processor
Electronics Mfr.
Flowrate
(1000 gpd)
610
440
260
1,020
Problem Pollutant*
BOD, TSS, FOG
BOD, FOG, pH
" BOD, TSS, FOG, Color
Primary Clarifier*
Overflow Rate, gal/sf/day
Detention Time, hours
PLANT LOADING
Typical (Upaet)	Tricklint Filters
500
3.6
BOD5 loading, lbs/1,000 cu ft/day
Recycle, %
Typical (Upaet)
33
100
Secondary Clarillara
Typical (Upaet)
Overflow Rate, gal/sf/day
Detention Time, hours
415
4.3
Aeration Basins
F/M, lbs BOOj/lbs MLSS/day
MCRT, days
MLSS, mg/1
Detention Time, hours
Return Floi, %
D.O. Level, mg/1
0.27 (0.30)
5-6
1,800 (2,000)
7.5
50 (60)
I
PLANT PERFORMANCE
Permit Limit	Typical (Upaet)
BOD5, mg/1 20	8 (36)
SS, mg/1 20	12(37)
UUf
WASTEWATER
FINAL
BAH
SCREENS
CHLORINE
CONTACT
, BASINS
(a) y
onrr
CHAMBERS
RAS
EQUAUZA1
BAStM
LARIFIERI
. (2) ,
PRIMARY
CLAMI-
, FIERS j
1ST
STAOE
/TRICK UNO
FILTERS
(2)
2 NO
STAGE
TRK*UNO\
FILTERS
(2)
ZmwiarX
fotQESTEWlV	,
215

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NEWBERG WASTEWATER TREATMENT PLANT
Newberg, Oregon
The Newberg Wastewater Treatment Plant (NWTP) has experienced periodic
episodes of non-compliance with their NPDES Permit for approximately ten
years due to fluctuating BOD loadings, and biological upsets caused by excessive
copper discharges. In general, copper discharges have not limited sludge disposal
options. With implementation of a pretreatment program and tighter industrial
discharger limits, interference incidences have become more infrequent since
mid-1984. NPDES discharge permit compliance should increase in the next two
years as some industrial waste permit limits are tightened and a completely new
treatment facility with greater hydraulic capacity is brought on line.
The two main industrial contributors to the NWTP are a circuit board manufac-
turer (cbm) and a fruit processor (fp), both of which operate year-round. The
cbm has been discharging wastewater to the NWTP since 1974, but the flowrate
was increased in 1978 when it was discovered by the Oregon Department of
Environmental Quality (DEQ) that a wastestream with copper concentrations as
high as 50-80 ppm was being directly discharged to a local stream. Subsequent
biological failure of the NWTP showed copper levels as high as 100 ppm in the
primary clarifier sludge. The incident required reseeding of the biological
population and 45 days to completely recover. Because of regular upsets, the
City began sampling and testing for pH and copper in 1981 at the first manhole
downstream of the cbm facility. The City experienced great difficulty in
working with the cbm to reduce copper levels and periodic discharge problems
continued until May, 1984 when copper discharges caused a complete activated
sludge and anaerobic digester failure. With pressure on the City by the DEQ and
an updated sewer ordinance with more "teeth", the City aggressively pursued
compliance by the cbm. A "show cause" hearing resulted and rather than address
the pretreatment issue, the cbm chose to cease production and lay off
50-60 people.
The cbm reopened later that summer with the new pretreatment equipment
required to comply with its industrial waste discharge permit. Since installing
pretreatment, the cbm has been in constant compliance. Wastewater monitoring
of the cbm continues.
The second major industrial discharger which has caused the NWTP to violate its
NPDES Permit is a processor of pie cherries. The fp requires on the average,
one third of the NWTP BOD treatment capacity which normally does not present
a problem. However, waste strength variability can result in the fp contributing
2900 pounds of BOD in one day to the plant which is designed to handle
3200 pounds/day. With the addition of the domestic BOD load, the biological
process is overwhelmed. Typically, this occurs in the summer at low plant
flowrates and can cause the effluent BOD to rise to 50 mg/1. The fp has been
responsive to the City's pretreatment program and tighter industrial waste
discharge limits, which have attempted to solve the problem. Stricter industrial
discharge limits may be imposed by the City when the fp's permit is renewed in
the near future. A good working relationship between the City and the fp has
made corrective actions easier to implement than in the case of the cbm.
216

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In dealing with all industries in town, the City has attempted to work coopera-
tively to implement pretreatment and issue industrial waste discharge permits.
The City has paid up to one half of all consulting fees associated with industries
implementing pretreatment, and has paid for most laboratory analysis of
wastewater samples.
Newberg experiences substantial I/I which on occasion contributes to non-
compliance problems by hydraulically overloading the treatment process. The I/I
problem is being addressed by the City.
217

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NKVBKRC WASTEWATER TREATMENT PLANT
NEW BERG, OREGON
Deaipn Flow:	2.0 mgi	Location:	Noflio«tl
Secondary Treatment: Coayblt UU	Population Served: 11,000
Activated Skiigl
INFLUENT VASTl'iATIR
SIGNIFICANT MDOSTRIB
Ave. Flow, nigd
H Industrial
BODj, rag/1
SS, rag/I
Cu, rag/1
Typical (Opawt)
S>m	Wtalw
1.26	Z.O
10
2J0DS0)	130 (2)0)
170	90
< I (10-50)
Circuit Board Manuf.
Fruit proceaaiag
Pbet«t«
llONoi)
4i
ftafclam MktaU
Cu, pH
BOD
Priaarr Civilian
Overflow Rate, gal/sf/day
Detention Time, bours
Civilian
Overflow Rate, gal/»f/day
detention Time, hours
PLANT LOADING
Typical (Upaat)	A
1,070
1.0
Typical (Opaat)
5)0 and 470
>.4 and 5
MCRT, day*
MLSS, mg/1
Detention Time, houra
Return Flow,
D.O. Level, mg/1
Typicel (Opaati
4-S
1200-2000
4.7
50-70
1.5-2.5
PLANT PERFORMANCE
Paralt Umit Typical (Upaat)
Sum Ibia
BOD;, mg/1	20	)0	25 150-100)
SS, mg/1	20 )0	IS
RAW
WASTEWATER
SECONDARY
CLARIFIER8
AERATION
¦ A8INS
(2)
CHLORINE
CONTACT
CHAMBER
OR1T CHANNELS
AMO
COMMIWJTORS
(2)
WAS
V
LAND
APPLICATION
Anaei
218

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METRO-WEST POINT TREATMENT PI.ANT
Seattle, Washington
The Municipality of Metropolitan Seattle (METRO) has had an operational
industrial pretreatment program since 1969. With minor modifications, the
program was EPA-approved in 1981 as one of the fn-i in the nation. Successful
reductions in influent wastewater and primary sludge heavy metal concentrations
during the last five years can, to a great extent, be attributed to implementation
and enforcement of pretreatment standards. As an outcome of this, self-
monitoring by industrial dischargers augmented with year-round spot monitoring
by Metro's Industrial Waste Section has reduced the incidences of toxic upsets in
the anaerobic digesters of the West Po.nt Treatment Plant and in the activated
sludge process of the neighboring Renton Treatment Plant.
The Metro-West Point Treatment Plant provides primary treatment and sludge
digestion for an average daily wastewater flow of 132 m^d, 4.7 percent origi -
nating from industrial sources. Approximately 7U metal finishing/electroplating
industries discharge to the sewer system in addition to a variety of other
categorical and non-categorical industries. Records of periodic digester upsets
go back as early as 1967, but their occurrences have become less frequent since
1980, coinciding with substantial overall reductions in heavy metal concen-
trations. Past upsets directly linked to toxic metals (generally chromium) caused
increased volatile acid concentrations, increased carbon dioxide content of the
gas produced, reduced gas production, and in a few cases caused complete failure
of the digesters. An October, 1980 chromium spill to the West Point facility
caused a typical upset and resulted in the plant influent chromium concentration
jumping 10 fold to greater than 2 mg/1. Primary sludge concentrations of
chromium reached 71r mg/1, resulting in a 30 mg/1 increase in digester
concentrations above their normal 16-17 mg/1 level. Land application of the
sludge was not altered, as presently there are no established allowable metals
application rates for silvercultural use.
Figure C-6 below typifies the reduction in metals realized during the 198'—1985
time period. Plant influent chromium levels dropped approximately 55 percent
while the digested sludge concentrations were reduced by more than 40 percent.
The magnitude of these decreases cue typical of other heavy metrls as will,
averaging 44 percent for chromium, cadmium, copper, lead, nickel and zinc
combined (see the accompanying data sheet). The primary reason for the
reduction of cadmium and chromium concentrations is improved industrial
pretreatment. In addition to pretreatment, a less corrosive city water supply has
also resulted in lower background metal concentrations for the other metals,
especially for copper. The city recently began chemically conditioning its water
in an attempt to extend conduit life.
Success of the Metro Industrial Pretreatment Program can be attributed to a
number of important factors including:
• development of stringent local limits for industrial discharges;
219

-------
•	year-round industrial waste sampling programs supported financially
by industry; and
•	follow-up procedures to industrial waste spills, taking enforcement
action and levying fines when necessary.
Metro has recently implemented the following steps to improve their
pretreatment program:
•	information exchange wifh industries through the use of quarterly
newsletters and personal communications and
•	increasing public awareness of industrial discharge violators by
publ.hing the names of violating companies in local papers along
with a statement ot Metro's enforcement policy.
Chromium Waat Point 1981 to 1905
100-j-
Cr Trand Sludga
& uo- ¦
-	O— EFFLUENT L0S/OAY
INFLUENT L3S/0AY
-	7- 00 SLUQCE MG/KC
	BEST UNE FIT SLUOCf
FIGURE C-6
WEST POINT CHROMIUM CONCENTRATIONS
220

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WIST rr-TMT TREATMENT PLANT
SEATTLE, WASHINGTON
Design Flow;
Primary Ttutaat
115 mgi
Location:
Population Served:
W«»t-Ce
500, OOC
itrai Waahiagtoa
INFLUENT WASTEWATER
Are. Flow, mgd
r. Industrial
BOD5, tng/1
SS, mg/1
Cr, Mg/1
Typical (Op»e0
132
5
160
260
0.05 (2.0)
SIGNIFICANT INDUSTRIES
Industry
Metal finishing and
electroplating
Flowrate
(mgd)
1.1
PNbltH Pollutant*
Cd, Cr, Cu, Ni, Z»
Primary Clxxifierv
Overflow Rate, gal/if/day
Detention Time, hours
Effluent BOD$, mg/1
Efflueot SS, mg/1
PLANT LOADING
Typical (OpMt)
1080
1.58
75-110
60-90
Digested Sludge Uetal Coacaattaticne
Cadmium, mg/kg
Chromium, mg/V.g
Copper, mg/kg
Nickel, mg/kg
Lead, mg/kg
I9SI Iml
45
480
1300
160
800
198S Level
28
250
700
120
400
PLANT PERFORMANCE
BOD5, mg/1
SS, mg/1
Cr, mg/L
Permit limit	Typical
Summer Winter	Summer Winter
135 85	110 75
125 65	90 60
0.07 0.07	<0.05 (0.15)
RAW
WASTEWATER
FINAL
EFFLUENT
AERATED
QRIT CHAMBERS
(4)
BAR
SCREENS
LAND
APPLICATION
CENTRIFUGE
CENTRIFUGE
CHLORINE
CONTACT
CHANNELS
(2)
PRIMARY
CLARIFIERS
(12)
CENTRIFUGE
THICKENING
ANAEROBIC
DIGESTERS
(3)
CENTRIFUGE
DEWATERING
(2)
221

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