ADDENDUM TO THE REPORT ENTITLED:
ASSESSMENT OF THE IMPACTS OF INDUSTRIAL DISCHARGES
ON PUBLICLY OWNED TREATMENT WORKS
Submitted to the Environmental Protection Agency
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ADDENDUM TO THE REPORT ENTITLED:
ASSESSMENT OF THE IMPACTS OF INDUSTRIAL DISCHARGES
ON PUBLICLY OWNED TREATMENT WORKS
February 25, 1983
Submitted to:
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C.
In Response to:
EPA Contract No 68-01-5052, DOW 54
JRB Project No. 2-834-03-587-37
EPA Contract No. 68-01-6514, WA #2
JRB Project No. 2-834-03-434-32
Submitted by:
JRB Associates
8400 Westpark Drive
McLean, Virginia 22102
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February 25, 1983
Mr. Tom O'Farrell
Office of Water Regulations and Standards
Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
Dear Tom:
Enclosed is a copy of our third revision of the RIA Addendum Report. A
number of specific changes have been made in response to your comments. In
addition, certain modelling assumptions have been verified and corrected with
the resulting impacts incorporated throughout the report.
Should you have any questions concerning this report or any additional
changes you wish made, please do not hesitate to contact me at the above
address or by telephoning (703) 821-4619.
Sincerely
cc: Bill Diamond
Robert Eagen
Bruce Clemens
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TABLE OF CONTENTS
Page
INTRODUCTION i
1.0 REGULATORY BACKGROUND AND PUBLIC COMMENTS 1-1
1.1 BACKGROUND 1-1
1.2 PUBLIC COMMENTS ON THE CONTRACTOR'S REPORT 1-2
2.0 METHODOLOGY 2-1
2.1 PRETREATMENT RIA METHODOLOGY 2-1
2.1.1 Environmental Measures 2-1
2.1.2 Cost Assessment 2-3
2.1.3 Data Limitations 2-4
2.2 DATA INPUT CHANGES 2-5
2.2.1 Industrial Pollutant Loadings 2-5
2.2.2 Industrial Discharger Flow 2-6
2.2.3 Pretreatraent Technology Cost 2-9
2.2.4 Stream Flow Data 2-9
2.3 METHODOLOGY CHANGES 2-12
2.3.1 Toxic Organics 2-12
2.3.2 Modified Water Quality Criteria 2-15
2.3.3 Metal Finishing Software Package 2-18
2.3.4 Industrial Sludge 2-19
2.3.5 Low Stream Flows 2-21
2.3.6 Prediction of Inhibitory Potential at POTWs 2-22
3.0 FINDINGS 3-1
3.1 WATER POLLUTION 3-2
3.1.1 Exceedances of Water Quality Criteria 3-2
3.1.2 Improvement in POTW Effluent Ouality 3-7
3.1.3 Potential Interference with POTW Operation 3-9
3.2 SLUDGE CONTAMINATION 3-9
4.0 ANALYSIS OF PRETREATMENT OPTIONS 4-1
4.1 ENVIRONMENTAL EFFECTS OF THE OPTIONS 4-2
4.1.1 Removal of Pollutants 4-2
4.1.2 Effectiveness in Reducing Water Quality Exceedances 4-4
4.2 COMPLIANCE COST OF THE OPTIONS 4-5
4.3 SUMMARY 4-8
APPENDIX
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LIST OF TABLES
Table Title Page
1.1 Substance of the Comments on the JRB Report 1-4
2.1 Comparison of Direct Versus Indirect Discharges 2-7
2.2 Average Flow (CO) of Model Industrial User 2-8
2.3 Pretreatment Technology Cost/1,000 Gallons 2-10
2.4 Current Industrial Wastewater Characteristics Total Toxic
Organics 2-14
2.5 Comparison of the Federal Water Quality Criteria
For Aquatic Life to the Modified Criteria 2-17
2.6 Onset Concentrations for Process Inhibitions at POTWs 2-22
3.1 Model Indicators of Water Quality Exceedances Using Mean Flows and
Modified Criteria 3-4
3.2 Model Indicators of Water Quality Exceedances Using Low Flows And
Modified Criteria 3-6
3.5 Percent Improvement in POTW Effluent Quality with Pretreatment
Program 3-8
3.6 POTWs Predicted to Experience Inhibition Potentials In
Nitrification, and Activated Sludge Processes 3-10
3.7 Sludge Quality With and Without Pretreatment From Modeling Exercise 3-11
3.8 Percent Improvement in Sludge with Pretreatment Program 3-13
4.2 Impact of the Options on Environmental Residuals 4-3
4.3 Effectiveness of the Options in Reducing Exceedances 4-6
4.4 Total Cost of the Options for POTW and Industry 4-7
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INTRODUCTION
The following report is an addendum to a report prepared for the
Environmental Protection Agency in conjunction with the Agency's performance
of a regulatory impact analysis of the National Pretreatment Program. The
original report entitled, "An Assessment of the Impact of Industrial
Dischargers on Publicly Owned Treatment Works," (JRB Associates, Nov. 1981)
contained data and analytical results on the following:
The operation and status of the current pretreatment program
The need for pretreatment
Six regulatory alternatives for industrial waste control
The costs and benefits of the current program and regulatory
options.
To generate this contractor report, an extensive computer model was developed.
The report and accompanying appendices, therefore, also contained detailed
descriptions of the data files and methodologies used to make economic and
environmental predictions about the National Pretreatment Program and the
alternative approaches for industrial waste control at POTWs.
The original report was made available to the public on December 22, 1981
(46 Fed. Reg. 62098). At this time, the public was invited to submit
additional data bearing on the analysis, and to comment on the methodology,
data base, options, and preliminary results of the contractor's report.
This addendum report presents new findings for the RIA stemming from data
modifications and methodological changes made as a result of public comments,
meetings held with interested parties, and additional review by EPA offices.
It constitutes a final refinement of the technical work for the Pretreatment
RIA.
1)
2)
3)
4)
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This addendum report is organized into four chapters:
Chapter 1 provides the regulatory background for this report
and presents a summary of the public comments received on the initial
report.
Chapter 2 gives detailed information on the data modifications
and methodological changes made to the RIA model and data bases.
Chapter 3 presents new findings (paralleling those presented
in the tables of the interim report) resulting from the changes
described in Chapter 2. Revised predictions are made for
environmental improvements attributable to implementation of
pretreatment and brief comparisons are made with the original report.
Chapter 4 takes the new model results and presents a revised
comparison of the costs and benefits of the current pretreatment
program with the other regulatory options analyzed. Again the
results are presented in tables corresponding to those in Chapter 4
of the original report, and brief comparisons are made.
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1.0 REGULATORY BACKGROUND AND PUBLIC COMMENTS
1.1 BACKGROUND
EPA issued amendments to the General Pretreatment Regulations on January
28, 1981, which were to have taken effect on March 13, 1981. On January 29,
1981, the Administration froze a number of regulations including the General
Pretreatment Regulations (GPR) and postponed their effective dates until March 30,
1981. On February 17, 1981, Executive Order 12291 was issued altering the
procedural and substantive review requirement incumbent on Federal agencies
for new, existing and pending regulations. Executive Order 12291 was invoked
on March 27, 1981, to indefinitely suspend the applicability of the GPR until a
regulatory impact analysis (RIA) was prepared by EPA. An R1A is essentially an
evaluation of the need for and consequences of a proposed regulatory action and
alternatives to this action. The goal of an RIA is to determine if the potential
benefits to society outweigh potential costs for any regulatory action.
EPA commenced the Pretreatment Regulatory Impact Analysis in February of 1981
with the formation of an Intra-agency Working Group on Pretreatment. This group
assumed responsibility for directing a comprehensive evaluation of the National
Pretreatment Program to fulfill the objectives of Executive Order 12291. The group
selected an approach which melded in-house analyses with contractor support, drawing
on several offices and resources within EPA and employing JRB Associates as the
principal consultant to the project. The results of several studies and data
collection efforts performed by the Office of Analysis and Evaluation and the
Effluent Guidelines Division of OWRS, and the Permits Dvision of OWEP were merged
with additional work conducted by JRB Associates and five subcontractors to assess
the magnitude of problems caused by indirect industrial dischargers, the efficacy of
the Agency's current approach to their control (as embodied in the National
Pretreatment Program), and potential alternatives for industrial waste control at
POTWs.
Specifically, JRB Associates was contracted to gather data, create an extensive
data base and produce a preliminary report which evaluated the environmental,
health, and interference impacts of industrial discharges of toxic pollutants to
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publicly owned treatment works. Additionally, the costs and benefits of possible
alternatives were to be examined. Work commenced in April of 1981 and an interim
final report was submitted to EPA in November 1981. This report, entitled "An
Assessment of the Impacts of Industrial Discharges on Publicly Owned Treatment
Works" was made available to the public on December 22, 1981 (46 Fed. Reg. 62099),
and a comment period of 45 days to February 5, 1982, was provided. The public was
invited to submit additional data for inclusion in the analysis and to comment on
the methodology, database, options, and preliminary results of the contractor's
report.
Concomitant with the preparation of this technical report, several major
regulatory and legislative developments have occurred which affect the status of the
National Pretreatment Program and the General Pretreatment Regulations. On February
1, 1982, the amended 1981 General Pretreatment Regulations (except for four
provisions) were promulgated (47 Fed. Reg. 4518). Then, in July of 1982, a Federal
court in the Third District found that in the course of suspending the General
Pretreatment Regulations to allow the RIA to be conducted, EPA failed to follow
procedures required in the Administrative Procedures Act (NRDC v. EPA, No. 81-2068).
As a result, the court reinstated the General Pretreatment Regulations in their
entirety, making their effective date retroactive to March 30, 1981. This was
announced in the Federal Register on September 28, 1982 (47 Fed. Reg. 42688). At
the same time, EPA issued a proposed rule to modify the removal credits provisions
of the General Pretreatment Regulations (47 Fed. Reg. 42698).
1.2 PUBLIC COMMENTS ON THE CONTRACTOR'S REPORT
EPA received 53 formal comments on the Contractor's report for the
Pretreatment RIA. This included responses from 18 local governments, eight
State governments, two EPA Regions, 19 industrial commenters, five private
individuals or consultants, and one public interest/environmental group.
Thirty-seven of these respondents directed their remarks solely to the
selection of a preferred option. Seventeen comments included both options
recommendations, data, and methodological observations. Table 1.1 presents a
distillation of the substantive issues raised by these public comments.
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EPA and JRB took an extensive look at the validity and the implications
of theBe criticisms. Responses were prepared for each in an in-house exercise
to evaluate where modifications to the model or findings were warranted. In
many instances, the comments reiterated limitations and assumptions acknow-
ledged in the report for which no better alternatives existed. For instance,
the enhancement of municipal sludge disposal options due to improved sludge
quality attributable to pretreatment is one of the central goals of the
National Pretreatment Program. Quantitative measures of these benefits are
therefore crucial to an overall evaluation of the program. Yet, no reliable
mechanism could be devised to systematically predict and credit these benefits
given the variability in municipal sludge disposal options and State and local
restrictions. Thus, the report presents estimates of improvements in sludge
quality as predicted by the model, case studies, and the 40 POTW study, but is
unable to attach associated monetary or operational benefits to this improve-
ment .
On the other hand, several comments were identified for which time and
data were available to permit revisions to the Pretreatment model. A detailed
discussion of the data and modelling modifications undertaken in response to
conments is presented in Chapter 2. Briefly, this effort included expansion
of the stream flow file, revision of the pretreatment technology costs, a
model verification study, changes to raw industrial wasteload data where
warranted, and validation of the data sources used. In addition, seven major
methodological changes were undertaken in response to the comments. These
entailed changes to the stream flows and water quality standards employed to
predict violations, an analysis of industrial hazardous waste definitions,
toxic organics predictions, the method of identifying metal finishers, pre-
diction of POTW inhibition, and the reporting of environmental impact
findings.
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TABLE 1.1
SUBSTANCE OF THE COMMENTS ON THE JRB REPORT
Data Comments
Industrial pretreatment technology cost data are too low.
Raw toxic metals discharge estimates are too high for the iron and
steel, the pulp and paper, the metal finishing, leather tanning,
textile, and inorganic chemical industries.
Estimates of current levels of pretreatment in place are too high.
Electroplater contributions to POTW influent are overstated.
Removal estimates for primary treatment plants are based on only
one facility.
Data on toxic metal loadings from non-point sources are weak.
Methodological Comments
The methodology used to identify indirect dischargers (Dun &
Bradstreet, PCS, and normalization) is inaccurate.
The benefits analysis is limited and not representative.
To do an accurate assessment of economic impacts, plant closures
should have been examined.
Methodological assumption that all industrial residuals are hazardous
wastes overstates the costs of industrial sludge disposal.
Model does not address the impacts on POTWs of the industrial
discharge of conventional pollutants.
Methodology places undue emphasis on water quality exceedances
rather than the mass of toxic pollutants discharged in assessing
environmental impacts.
Given that the number of POTWs required to have programs will
fluctuate, all quantitative results are unreliable.
The environmental impacts from the 114 tcxic organic pollutants are
ignored by modelling total toxic organics instead of individual
organic pollutants.
The Federal Water Quality Criteria are unrealistic, overly
restrictive, and should not have been used as the measure of water
quality attainment.
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TABLE 1.1 (continued)
7Q10 stream flows should have been used instead of average annual
stream flows to calculate dilution of POTW discharges.
The model did not address the impacts of bypasses, upsets, inhibition,
or groundwater contamination.
Policy Comments
The report overlooks the administrative difficulties in implementing
different regulatory options.
The report fails to deal with specific provisions of the Pretreatment
Regulations such as FDF variances and deadlines for categorical
determinations.
The report should have quantified options in terms of sludge disposal
alternatives.
The report overlooks the incompatiblity of proposed options with
the Clean Water Act.
The report should compare the cost of industrial pretreatment with
advanced wastewater treatment by POTWs.
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2.0 METHODOLOGY
This chapter summarizes the data and methodological changes made to the
model employed in the Pretreatment RIA to estimate the environmental and cost
impacts of industrial discharges to POTWs. Section 2.1 reviews briefly the
original analytical approach used to evaluate the General Pretreatment
Regulations (40 CFR 403) and a range of possible alternative regulatory
strategies. Sections 2.2 and 2.3 discuss in detail the input data and
methodological changes to this analytic approach. These were undertaken in an
attempt to strengthen the initial report and to address public comments.
2.1 PRETREATMENT RIA METHODOLOGY
To assist EPA in assessing impacts of industrial discharges to POTWs, JRB
developed a mass-balance computer model of a POTW system which quantifies -the
environmental benefits and costs for alternative pretreatment programs. JRB
developed this mathematical model for the approximately 2000 POTWs across the
country required to implement local pretreatment programs under the General
Pretreatment Regulations. The model simulates the operation of a single POTW,
distributes pounds of priority pollutants from industry among POTWs to allow
an assessment of water quality and sludge impacts, and allows aggregation of
individual results to national or regional totals. It consists of eleven data
sources, including Dun and Bradstreet industrial lists, EGD Industrial data,
EPA's Permit Compliance System, STORET, USGS, and EPA's NEEDS Survey, among
others. The types of outputs of the model are discussed in the following
subsections.
2.1.1 Environmental Measures
The POTW model estimates the following quantitative environmental
measures for alternative pretreatment options for each of the 2000 POTWs:
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Problem
Measure
Water Pollution
Exceedances of Water Ouality Criteria
Mass of Pollutants
Net Change in Effluent Quality
Sludge Contamination Volume and Contamination of Municipal Sludge
Volume and Contamination of Industrial Sludge
Air Pollution
Mass of Volatile Priority Pollutants Discharged
to Air
Most of these measures quantify for comparison among pretreatment options, the
volume of pollution reduced, the volume that continues to be discharged and
the concentration of toxics in the POTW effluent and in sludges.
Water quality exceedances, used as an indicator of potential water
quality problems, were calculated by comparing the concentration of a toxic in
the receiving stream to Federal Water Quality Criteria values for those
toxics. Where this in-stream concentration was greater than these criteria
values, an "exceedance" was said to occur. In the pretreatment RIA,
exceedances were calculated for nine heavy metals and cyanide. Due to the
lack of data available for individual toxic organics, toxic organics were
modeled in aggregate form only.
A parallel effort was made to analyze the significance of changes in the
concentration of priority pollutants in municipal sludge resulting from
indirect industrial discharges. However, due to the lack of currently
existing sludge disposal guidelines, JRB and EPA eventually decided that,
given time constraints, no meaningful sludge criteria could be constructed
for the pretreatment RIA. Therefore, the report made predictions on sludge
quantity and quality both for industry and municipalities. However, given the
lack of regulatory triggers, it is assumed that all industrial sludge is
hazardous (although some industrial sludges are no longer classified as
hazardous by EPA) and all municipal sludge is nonhazardous in calculating
associated disposal costs, regardless of sludge quality improvement or
degradation under the various options.
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Use or disclosure of proposal data is subject to the restriction on the Title page of this Proposal.
2.1.2 Cost Assessment
Having identified the central environmental problems to be controlled
under aiiy pretreatment program, and having chosen key criteria used to measure
the environmental impacts of alternative programs, it was necessary to
identify where the costs of compliance would be sustained so that data could
be collected and impacts estimated. The principal actors under any
pretreatment strategy are industry, POTWs, States, and the Federal government.
A decision was made to limit the cost assessment to the following direct
costs:
Industrial Impacts
Pretreatment Technology Compliance Costs
Sludge Disposal Costs
Municipal Impacts
POTW Pretreatment Program Development Costs
POTW Pretreatment Program Operational Costs
POTW Sludge Disposal Costs
State Impacts
State Pretreatment Program Development Costs
State Pretreatment Program Operational Costs
Federal Impacts
EPA Administrative Costs
Construction Grants for Pretreatment
The POTW Model provided treatment and sludge disposal costs. Administra-
tive costs for municipalities, States and the Federal government were based on
historical estimates and case study extrapolations.
A number of cost factors had to be excluded due to the lack of adequate
data or as a result of regulatory assumptions made above. For example,
municipal costs were net reduced to account for savings experienced by POTWs
due to the fewer operational problems attributable to an effective pretreat-
ment program. Sludge disposal cast savings similarly could not be passed on
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to cities where the improvement in sludge quality due to pretreatment
facilitates the use of a less expensive disposal option.
2.1.3 Data Limitations
In the pretreatment RIA, the ability to analyze the existing pretreatment
program and possible alternatives in a logical and complete manner was often
hindered by the lack of available health and environmental data. Solutions
were designed to overcome these data deficiencies where possible, but some
gaps could not be filled in the time frame of this study. For instance, no
single data source had complete data on the number, type, and location of
categorical industries discharging to individual POTWs. This information is
critical for constructing the raw wasteloads entering POTWs as a result of
industrial users. To surmount this inadequacy, Dun and Bradstreet computer
lists were searched by SIC codes to identify the universe of categorical
industries in the vicinity of a POTW. The Permit Compliance System Data Base
was then used to back out direct dischargers holding NPDES permits from this
total and these were assigned to the appropriate municipality according to the
city name of the POTW as stated on the NEEDS Survey. To ensure model accuracy
on a plant-by-plant basis, industrial flows to POTWs were then normalized to
approximate those reported in the NEEDS Survey.
In fact, every component variable in the assessment of water quality
impacts required assumptions in order to achieve results. The mass and volume
of discharge of priority pollutants from all IUs in an industrial category
were all assumed to be the same equal to those of an average firm. The
POTW receiving these wastes was assumed to attain average treatability levels.
Perhaps the greatest frustration with data weaknesses was experienced with
data on receiving stream characteristics. Stream flows were available for
less than half of the stream segments on which the approximately 2000 POTWs
are sited. Ambient water quality fcr all ten toxic pollutant parameters (nine
metals and cyanide) were almost uniformly unavailable resulting in the
assumption that POTWs are discharging to pristine waters, and the lack of
widespread State toxic water quality standards resulted in JRB's use of
Federal water quality criteria.
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Given that toxic water quality criteria are not widely accepted, that few
standards have been adopted by States, that State and local sludge disposal
criteria vary, and that there are not Federal sludge guidelines covering all
sludge disposal options, there were major shortcomings in the analysis. In an
attempt to overcome some of these weaknesses, correct input data errors, and
incorporate new input data received, JRB has modified some of the analytical
approaches to the pretreatment RIA. A detailed description of these
modifications are presented in Sections 2.2 and 2.3 of this chapter.
2.2 DATA INPUT CHANGES
Certain data inputs in the pretreatment model have been altered, either
in response to public comment or the acquisition of updated information, in
order to revise previous estimates of the impacts of industrial discharges on
publicly owned treatment works. These data input changes include industrial
pollutant loadings, the average flow from industrial dischargers, estimates of
pretreatment technology cost per gallon discharged, and the number of POTWs
for which stream flow information is available. These changes are discussed
in the following sections.
2.2.1 Industrial Pollutant Loadings
For the original report, the Effluent Guidelines Division of EPA supplied
data on the effluent characteristics for each of the categorical industries
modeled. The effluent description included specific concentrations for the
priority pollutant metals, but only a total concentration of the organic
priority pollutants. These effluent characteristics combined with industrial
flow (Section 2.2.2) were used for each categorical industry to determine the
flow and toxic loading of discharges to P0TW3.
Upon review of the industrial pollutant loadings presented in the
original RIA report, and on the basis of the comments received from
industry, pollutant loadings for certain industrial categories were thought to
be suspect. Therefore, each of the pollutant loadings was verified by
contacting specific EGD project officers, recalculating all of the data
originally supplied by EGD, and utilizing any updated information available
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since submission of the original report. In some instances, review of these
data necessitated changes while in others original estimates were verified by
EGD and therefore preserved. The results of this review are presented in
Table 2.1 (formerly Table 1.1 of the original report). The table reflects
changes in pollutant loadings for the iron and steel, leather tanning,
aluminum forming, pulp and paper, and coil coating industries. Additional
changes to industrial pollutant loadings and their impacts are reflected in
the results of the modelling exercise presented in Chapters three and four of
this report.
2.2.2 Industrial Discharger Flow
EGD also provided average flow data for model industrial users in each of
the 34 categorical industries. This flow information was combined with the
average industrial effluent concentrations provided by EGD to determine the
total pollutant load contributed to the POTW by industrial discharges.
As in the case of industrial pollutant loadings, the accuracy of these
average flow numbers was brought into question when the pretreatment RIA was
released for public comment. Therefore, a verification of the average flow
data supplied by EGD was undertaken to determine their accuracy. This
verification procedure consisted of recalculating all of the flow numbers from
the original EGD data as well as any updated information provided by the EPA
project officers. These numbers were then compared to both the average
industrial flow numbers presented in Table C3-IV of the RIA appendix, and the
average flow numbers actually inserted into the model. Discrepancies were
resolved in keeping with the original EGD estimates. It should be remembered
that these flow and concentration data are national averages. Values for
individual plants within an industrial category may vary considerably.
The results of this verification analysis are presented in Table 2.2.
The first column in Table 2.2 shows the average flow listed in Table C3-IV of
the RIA Appendix while the second column shows the average flow recalculated
from the EGD-supplied data and inserted into the model. The average flow of
the model industrial users in the iron and steal, and pulp and paper categor-
ies has been revised based on updated information from EGD. In addition, the
ft
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TABLE 2.1 COMPARISON OF DIRECT VERSOS INDIRECT DISCHARGES*
Indirect Discharge**
Metal Finishing/
fc! cr r roplat! ng
Iron & Steel
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TABLE 2.2
AVERAGE FLOW (CQ MODEL) OF MODEL INDUSTRIAL USER
Average Flow (mgd) Average Flow (mgd)
Category Table C3-IV Model
1. Aahesives & Sealants
2. Aluminum Forming
3. Auto & Other Laundries
4. Battery Manufacturing
5. Coal Mining
6. Coil Coating
7. Copper Forming
8. Electrical & Electronic Products
9. Electroplating & Job Shops
10. Explosives Manufacturing
11. Foundries
12. Gum & Wood Chemicals
13. Inorganic Chemical Mfg.
14. Iron & Steel
Leather Tanning
Electroplating & Captive Shops
17. Nonferrous Metals
18. Ore Mining & Dressing
Organic Chemical Mfg.
Paint & Ink Formulating
15.
16.
19.
20.
21. Pesticides
22. Petroleum Refining
23. Pharmaceutical Mfg.
24. Photographic Equip. & Supplies
25. Plastic & Synthetics
26. Plastics Processing
27. Porcelain Enameling
28. Printing & Publishing
29. Pulp, Paper & Fiberboard
30. Rubber
0.0106
0.0822
0.0062
0.0254
0.0
0.065
0.112
0.088
0.019
0.008
0.061
0.233
0.664
0.017
0.221
0.069
0.041
0.0
0.802
0.0007
0.0937
0.0936
0.1561
0.0117
0.802
0.01
0.0067
0.0028
0.878
0.0
0.0106
0.0822
0.0062
0.0254
0.0
0.065
0.112
0.088
0.019
0.0008
0.061
0.233
0.664
5.638
0.221
0.069
0.041
0.0
0.802
0.0007
0.0937
0.936
0.1561
0.0117
0.802
0.0
0.006 7
0.0028
2.099
C.O
31. Soap & Detergent Mfg.
32. Steam Electric Power Generation
33. Textile
34. Timber
35. Noncategorical Industries
0.0553
0.1414
0.2187
0.14457
0.113
0.0553
0.1414
0.2187
0,14457
0.113
Flow data are national averages
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average flow numbers for explosives manufacturing, petroleum refining, and
plastics processing are also different from those appearing in Table C3-IV.
These numbers were reported incorrectly in Table C3-IV but had been entered
correctly into the pretreatment RIA model.
2.2.3 Pretreatment Technology Cost
One of the outputs of the pretreatment RIA model is an estimate of the
total cost of pretreatment technology to industry. The Office of Analysis and
Evaluation supplied data estimating the total annual cost to each categorical
industry installing the pretreatment technology necessary to comply with the
pretreatment regulations, excluding costs expended to obtain current levels of
treatment. By dividing this number by the total categorical flow for that
industry, an estimate of the pretreatment technology cost per thousand gallons
of wastewater discharged was derived. This number was then used in the RIA
model in conjunction with the total industrial flow calculated for each
industry to estimate the pretreatment technology cost per industrial category.
This estimate was then summed across categories to arrive at the total cost of
industrial pretreatment technology assuming full implementation of categorical
standards.
Due to the constantly changing nature of this type of data and questions
concerning the accuracy of the estimates as they appear in Table C3-IV of the
RIA appendix, new estimates of the pretreatment technology cost per thousand
gallons discharged by industrial category were derived and incorporated into
this study. Table 2.3 presents the results of this analysis. The first column
presents the technology cost estimates as they appeared in Table C3-IV of the
RIA appendix and the second column shows the new estimates incorporated into
the model for this study. The discrepancies in these two columns reflect
incorrect reporting in the RIA appendix and new input data received from EGD
since the completion of the RIA.
2.2.4 Stream Flow P£ta
A total of 2000 POTWs nationwide were estimated by EPA and the States to
be subject to the General Pretreatment Regulations. Only 1,839 of these 2,000
POTWs were included in the RIA analysis. The remaining 161 POTWs were found
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Use or disclosure of proposal dats is subject to the restriction on the Title page of this Proposal.
TABLE 2.3
PRETREATMENT TECHNOLOGY COST/1,000 GALLOWS
TABLE C3-V
INDUSTRY APPENDIX C MODEL
Adhesives & Sealants* 8 a/a
Aluminum Forming 22.00 4.25
Auto & Other Laundries* n/a
Battery Manufacturing 8.20 3.13
Coal Mining* n/a
Coil Coating 2.80 2.74
Copper Forming 1.40 1.44
Electrical 25.00 2.87
Metal Finishing-Job Shops 1.96 4.00
Mech. Products-Captive Shops 3.17 1.65
Explosive Manufacturing* n/a
Foundries 1.80 1.05
Gum & Wood Chemicals* n/a
Inorganic Chemical Manufacturing 0 .85
Iron & Steel .09
Leather Tanning 5.30 3.25
Non-Ferrous Metals 7.90 7.17
Ore Mining & Dressing* n/a
Organic Chemicals Manufacturing 1.30 1.64
Paint & Ink Formulating 34.00 49.50
Pesticides 12.00 6.70
Petroleum Refining .29
Pharmaceutical Manufacturing* a/a
Photographic Equipment* a/a
Plastics & Synthetics 1.30 1.64
Plastics Processing* n/a
Porcelain Enameling 59.00 45.35
Printing & Publishing* n/a
Pulp, Paper & Paperboard .034 .00
Rubber* n/a
Soaps & Detergents* n/a
Steam Electric .00
Textiles 2.60 .26
Timber* n/a
~Industries not currently required to meet categorical standards,
n/a - not applicable.
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to have no flow according to the NEEDS survey attributable either to file
error or that the plant is currently under construction and were, there-
fore, excluded from the analysis. In order to estimate the water quality
impacts resulting from the industrial discharge of toxic pollutants via these
POTWs, it was necessary to obtain flow information on the streams receiving
these discharges. By utilizing POTW-to-stream dilution, the model calculates
the concentration of each pollutant in the receiving water body as a result of
the POTW discharges. In the original model, the complete stream data
necessary to estimate these in-stream pollutant concentrations were available
for only 665 POTWs.
In order to improve the accuracy of the predictions of water quality
impacts presented in the RIA analysis, additional receiving stream flows
for the 1,839 POTWs modeled have been included in this study. Specifically,
receiving stream flows for 853 additional POTWs (bringing the total to 1518)
have been incorporated into the computer model. The remaining 321 POTWs
discharge into lakes and oceans. As no simplified methodology existed for
estimating the dilution of these discharges by dispersion and mixing in these
receiving water bodies, they were excluded from the RIA analysis. The
additional 853 receiving stream flows were generated from the STORET data base
which had been updated since the completion of the RIA.
A comparison of the receiving stream flows reported for the 665 POTWs
modeled in the contractor's report and the 1518 POTWs modeled for this report
reveals some significant differences. The average receiving stream flow of
the 665 POTWs in the initial data file was 13,400 CFS with a median of 547
CFS. For the 1518 POTWs modeled in this report the average receiving stream
flow is 8,000 CFS and the median is 160 CFS. This means that the results of
the modeling exercise presented in the original RIA report were biased towards
higher receiving stream flows and, therefore, higher stream dilutions than are
representative of the 2,000 POTWs thought to require pretreatment. An
analysis of how these additional stream flows affected predictions of the
water quality impacts resulting from the imposition of pretreatment is
presented in Chapter 3.
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2.3 METHODOLOGICAL CHANGES
The methodology used in the computer modeling exercise to assess the
impacts of industrial discharges on POTWs has been revised for this study to
reflect a number of criticisms received from public comment on the RIA report.
Efforts were made to include the modelling of individual toxic organic pollu-
'» tants, the use of site specific water quality criteria to measure water
quality exceedances, the inclusion of a software package which provides a more
detailed accounting of the metal finishing category, a more precise methodo-
logy of determining the cost of industrial sludge disposal, and the use of
7Q10 stream flows to calculate water quality exceedances. A detailed des-
cription of each of these methodological changes is presented below.
2.3.1 Toxic Organics
At the time the pretreatment RIA was conducted, time constraints and data
availability prohibited the estimation of the impact of individual toxic
organic pollutants on water quality. Instead, the water quality impacts
resulting from industrial discharge of toxic organic pollutants to POTWs were
addressed in aggregate form. However, recognizing the importance of the
discharge of these toxic organic pollutants to water quality, an effort was
made in this study to estimate their impacts on an individual basis.
While individual toxic organic pollutants have been included in the RIA
computer model for this study, certain constraints limited the level of detail
possible. First, EGD has not entirely verified all organic priority pollutant
discharge data from the 34 industrial categories modelled. Therefore, it was
necessary to focus our data collection efforts on those industrial categories
believed to be the primary contributors of toxic organic pollutants to POTWs.
Based on this criterion, the EPA project officers for the organics and
plastics, metal finishing, and iron and steel industrial categories were
contacted to obtain specific toxic organic pollutant concentrations. More
than 100 toxic organic compounds appear on the priority pollutant list - a
number unmanageable in this revision. Therefore, the disaggregation of
organics was limited to the five most significant pollutants discharged by the
thrae industrial categories selected.
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The following methodology was used to select the five toxic organics to
be modeled in this report. Data on the total pounds of specific toxic
organics discharged by the organics and plastics, metal finishing, and iron
and steel categories (supplied by the EGD project officers) were ranked from
highest to lowest. The top five organics for each industry in terms of pounds
discharged annually, were selected and then compared to determine any
similarities between industries. This resulted in a list of eight different
toxic organic pollutants. This list was reduced to five based on a
calculation which estimated the potential of these eight organics to exceed
water quality standards. Where it was clear that an exceeedance could never
be calculated, this pollutant was eliminated. This calculation was based on
the following equation:
potential ¦ toxic organic concentration x (1 - removal)
threshold value for chronic effects
where:
(1) Toxic organic concentration equals the highest concentration of
a specific organic observed for the three industrial categories
supplied by EGD (Table 2.4)
(2) Removal equals the estimated POTW removal for the toxic organic
as derived from the 40 POTW study
(3) Threshold value for chronic effects is the concentration taken
from the Federal Water Quality Criteria Documents at which chronic
aquatic life effects have been observed to occur as a result of the
presence of the particular toxic organic pollutant.
Based on the results of this analysis, the toxic organic pollutants
modeled in this study include: benzene, toluene, phenols, 1,1,1-trichloro-
ethans, and Bis (2 ethyl-hexyl) phthalate. Having selected both the key
industrial contributions end the major toxic organics to be considered in the
model, POTW water quality exceedances attributable to these toxic organic
discharges were forecast using the same methodology employed for toxic metals.
Wasteloads of these five compounds discharged to POTWs were constructed using
average pollutant concentrations for each of the three industrial categories.
These are presented in Table 2.4. The POTW removals assumed to calculate POTW
effluent were 35 percent for primary treatment plants, 79 percent for
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TABLE 2.4
CURRENT INDUSTRIAL WASTEWATER CHARACTERISTICS
TOXIC ORGANIC POLLUTANTS (mg/1)
Iron &
Steel
Chronic
Metal . Organics . Threshold
Finishing & Plastics Levels
Benzene 3.39 .080
Toluene 1.68 .170
Phenols 14.84 -
1,1,1-Trichloroethane - 1.90
Bis (2 Ethyl-Hexyl) Phthalate
8.70
5.70
11.10
.0039
.082
.053
.175
2.56
.528
.003
* Industrial effluent concentration prior to POTW treatment
2
Threshold levels in stream concentration triggering water quality
exceedances
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secondary treatment, and 86 percent for tertiary treatment. These removals
were derived from the 40 POTW Study (see Appendix C of the original RIA
report) and account for the removal within the POTW.
The resulting concentrations of each toxic organic pollutant in POTW
effluent were then compared with water quality benchmarks to predict
exceedances. The benchmarks employed were taken from the Federal Water
Quality Criteria Documents (45 Fed. Reg. 79318 et seq, November 28, 1980). As
with the metals predictions, chronic freshwater aquatic life values were used
to determine exceedances. Specific aquatic life criteria have not been
recommended for all priority pollutants due to a lack of data. In their
place, narrative descriptions of apparent threshold levels for acute and/or
chronic effects are presented to convey a sense of toxicity. The lowest
values of these apparent threshold levels (ATLs) were used as the modeling
surrogate for actual criteria recommendations. For three of the five organic
pollutants analyzed, no apparent threshold levels were presented for chron.ic
effects. Since the model relies on chronic freshwater aquatic life criteria
as exceedance benchmarks, chronic values for benzene, toluene, and 1,1,1-tri-
chloroethane were input to be one hundredth of the acute threshold level. The
last column in Table 2.4 presents the chronic threshold levels employed in the
model to determine water quality exceedances. Findings on the sludge and
water quality impacts of the discharge of these five toxic organic pollutants
to POTWs by the metal finishing, iron and steel, and organic chemicals
industries are presented in Chapter 3 of this report.
2.3.2 Modified Water Quality Criteria
Water quality exceedances were predicted in the contractor's report by
comparing the in-stream pollutant concentrations calculated in the model to
benchmark concentration levels to determine the likelihood of a pollutant
exceedance. Cue to the lack of widespread State toxic water quality standards
with which to evaluate water quality, Federal Water Quality Criteria values
were selected as the benchmark for exceedances and, therefore, potential water
quality problems. However, the selection of these criteria values as a bench-
mark evoked heavy criticism in the public comment to the RIA report.
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Use or disclosure of proposal data is subject to the restriction on the Title page of this Proposal.
Specifically, it was suggested that these numbers were overly stringent and
not representative of actual standards which would be adopted by States.
The Federal Water Quality Criteria were developed by EPA for specific
toxic pollutants in order to provide states with guidance in setting specific
water quality goals for receiving waters located in their domain. These
criteria values are derived by relating the concentration of specific pollu-
tants to information on water hardness, and the presence of aquatic species in
the receiving waters. The Federal criteria numbers were set to a level which
would be compatible with protecting the vast majority of life in all aquatic
communities. Direct application of the Federal criteria as the appropriate
value for water quality on that stream has been criticized as too stringent.
A more accurate indicator of water quality conditions would be one that is
sensitive to the site specific characteristics of receiving waters. For this
reason, a set of modified water quality criteria, derived from site specific
receiving water characteristics and resident species, has been inserted into
the RIA computer model in place of these Federal criteria.
Specific criteria values for some of the pollutants modeled in the RIA
were supplied by EPA for each of the streams modeled. These values are based
on specific species and water hardness characteristics determinations for
groups of receiving streams represented by a unique combination of State and
USGS cataloging units. In this report, these specific criteria are inserted
in the model for each group of receiving streams, replacing the set of generic
Federal criteria values used in the RIA. Table 2.5 presents a comparison of
the Federal water quality criteria values for aquatic life (RIA Appendix Table
C3-VIII) to the modified criteria values inserted into the model for this
Addendum report. For the purpose of comparison, minimum, maximum, and median
values for the modified criteria used in the model are shown in Table 2.5.
Of the ten pollutants presented in Table 2.5, five of them were not modified
and therefore their median values are the same as the Federal criteria values.
Median values for two of them, copper and lead, are more stringent, while
cadmium and nickel are less stringent. Cyanide remains the same. The water
quality impacts predicted by the model after these modified criteria were
inserted are presented in Chapter 3.
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TABLE 2.5
COMPARISON OF THE FEDERAL WATER OUALITY CRITERIA
FOR AQDATIC LIFE TO THE MODIFIED CRITERIA
Pollutant
Silver (Ag)
Arsenic (Ag)
Cadmium (Cd)
Total Chromium (Cr)
Copper (Cu)
Mercury (Hg)
Nickel (Ni)
Lead (Pb)
Zinc (Zn)
Cyanide(Cn)
Federal
Criteria Modified Criteria Values
Values (ug/1)
(ug/1) Max. Median Min.
.12 .12
440 440
.025 3.8 .038 .001
44 44
5.6 33.7 3.11 .132
.2 ~ .2
96 712.1 124.7 10.29"
3.8 70.2 2.76 .057
47 47
3.5 5.3 3.5 3.5
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2.3.3 Metal Finishing Software Package
The computer model developed for the pretreatment RIA has been modified
for this report to include a more detailed accounting of the metal finishing
category. Because of the importance of the metal finishing category as a
source of toxic pollutant discharges, this software package has been included
to better evaluate the impacts of industrial discharges on POTWs.
The metal finishing software package was designed by JRB under contract
to EPA to evaluate the environmental impacts of the proposed metal finishing
regulations and a range of alternative standards for indirect dischargers. In
order to improve the sensitivity of the environmental impacts attributable to
metal finishers, this industrial category was divided into several segments
The segments selected by EPA for analysis in this project were:
Captive Shops. Captive shops finish metal parts which they
themselves produce. There are two types of captive metal finishing
firms:
- Integrated Captive Shops. This segment of the metal
finishing category includes firms which electroplate parts and also
provides other metal finishing services (e.g., painting, sintering,
and welding).
- Hon-Integrated Captive Shops. These firms only use
electroplating processes.
Electroplating Job Shops. Firms providing both electro-
plating and metal finishing processes under contract to commercial
clients. This subcategory does not distinguish between integrated and
nonintegrated firms.
In the original contractor's report, the metal finishing category
included only the broader job and captive segments. The identification of the
number of IUs in each of these segments served by a POTW was based on two
surveys conducted by EPA which directly related the number of indirect
dischargers to the number of direct dischargers. This approach was neces-
sitated for the metal finishing category, as opposed to EGD estimates, because
of the larger number of sites that were defined as metal finishers according
to the SIC Code definition but which generate no wastewater. Therefore, the
computer modeling results presented in Chapter 3 of this reporc include a
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counting of metal finishing IUs and their contribution of flow and pollutant
loading consistent with the methodology used to calculate these variables for
all of the other categorical industries modeled. A detailed explanation of
this basic methodology can be found in Appendix C-3 of the contractor's
report.
2.3.4 Industrial Sludge
Calculations of the incremental cost of industrial sludge disposal as a
result of industrial pretreatment received criticism in the public comment on
the contractor's report. In the initial report, the RIA computer model
generated estimates of the total quantity of industrial sludge generated based
on some simplifying assumptions concerning toxic metals and TSS removals.
Sludge generated by all industrial categories was assumed to be hazardous,
with a disposal cost of $400 per ton of dry solids (including transportation).
By applying this disposal cost to the pounds of industrial sludge generated,
the total cost for industrial sludge disposal was derived.
In an attempt to provide a more realistic prediction of the total cost
for industrial sludge disposal, the following tasks were undertaken in this
report:
Identification of sludges generated by industrial
categories which could be classified as nonhazardous
Verification of the cost per ton of disposing of
hazardous sludge.
The methods used and results of these tasks are described in .detail below.
The disposal costs of landfilling wastewater pretreatment sludges are
expected to vary according to whether or not the sludge would be defined as a
RCRA hazardous waste. Such a designation requires that the sludge be disposed
in a secure landfill and therefore be subject to average hazardous waste
disposal costs. Any nonhazardous pretreatment sludges could be disposed of in
a lass expensive manner.
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An industrial sludge is determined to be a RCRA hazardous waste if it is
specifically listed in Subpart D of AO CFR, Part 261, or if it "fails" one of
the four RCRA characteristics in Subpart C of 40 CFR, Part 261. To determine
whether a given industrial pretreatment category or subcategory may produce a
hazardous sludge (and therefore may pay higher sludge disposal costs), the
following sequential procedure was used:
« Each wastewater treatment sludge was compared to sludges listed in
Subpart D of 40 CFR, Part 261. If a sludge was found to be a listed
hazardous waste, the industry producing that sludge was assumed to be
paying secure landfill disposal costs.
For each industrial category or subcategory not producing a listed
RCRA sludge, raw wastewater was evaluated to obtain a conservative
estimate on whether the resulting sludge, would be EP toxic under
Subpart C of 40 CFR, Part 261. The evaluation procedure used a
multiplier which was applied to the concentration in mg/1 of each SP
contaminant in the waste stream. If, after application of the
multiplier, the concentration of the contaminant exceeded the EP toxic
limit, the sludge was assumed to be potentially hazardous and
therefore subject to higher disposal costs. The conservative
multiplier was devised by assuming:
- 100 percent removal of EP contaminants from the
raw wastewater
- 100 percent dissolution of the EP contaminants
from the sludge during the EP procedure
- a low sludge generation rate of .003 lbs/gallon of
wastewater tc ensure maximum concentration of EP contaminants in the
sludge.
For each industrial category or subcategory not producing a listed
RCRA sludge or a raw wastewater with EP contaminants, it was assumed
that the sludge would be nonhazardous. This assumption is based on
the knowledge that most hazardous sludges are hazardous because they
exhibit the characteristic of EP toxicity. Most hazardous sludges
would not "fail" the RCRA characteristics of ignitability, corro-
sivity, or reactivity without also failing the characteristic of EP
toxicity.
^ This low sludge generation rate was developed based on the professional
judgment of individuals knowledgeable in industrial treatment processes.
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Based on the results of this review of industrial sludge character-
ization, wastewater sludges from only a few industrial processes could clearly
be classified as nonhazardous. Only wastewater sludges generated by the
adhesives and sealants and rubber processing categories are not specifically
listed as hazardous under RCRA and meet the EP toxicity tests described above.
All other industrial wastewater sludges are either specifically listed or fail
the EP toxicity test devised above. Therefore, the contractor's original
assumption that all industrial sludges are hazardous has been accepted
in this report.
A telephone survey of the cost of disposing of metal finishing sludges
was conducted to determine the accuracy of the assumption that the cost of
disposing of hazardous industrial sludge is $400 per dry ton. Metal finishing
sludges were chosen for this survey because they represent a fairly hazardous
industrial sludge and therefore provide a conservative estimate of the cost of
disposing of hazardous sludges. Cost estimates received in the telephone,
survey included the actual disposal cost per barrel as well as transportation
cost estimates. Based on the results of this survey, it was determined that
the $400 per dry ton estimate provided in the contractor's report represented
a high estimate of the actual cost of disposing of industrial sludges.
2.3.5 Low Stream Flows
The methodology used in the original pretreatment model to forecast water
quality exceedances assumed dilution of POTW discharges by stream flows equal
to^the average annual flows of receiving streams using chronic water quality
criteria values as the measure of toxicity. Public comments were received
which suggested that this assumption resulted in an understatement of water
quality impacts due to the exaggeration of actual stream flows and dilutions.
It was suggested that given seasonal stream flow variations, incorporation of
low flow values for streams should also be considered in modelling water
quality impacts.
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The use of low flows, as represented by 7Q10 data, has been performed for
this revised report to provide an upper bound for POTW water quality
exceedances with and without pretreatment. These low flow values were derived
using the same methodology as the derivation of average annual flows described
in Section 2.2.4 of this report. The results of this analysis are presented
( in Table 3-2(A)(B) of this report.
2.3.6 Prediction of Inhibitory Potential at POTWs
The original RIA report contained data showing that industrial discharges
of toxic pollutants caused process inhibitions, interference, O&M problems,
and upsets at POTWs. However, no systematic method could be developed for the
model which made quantitative predictions of the impact of industrial dis-
charges on POTW operations on a national scale under different regulatory
options. As one of the central goals of the Pretreatment Program is to
protect the integrity of POTW operations, a simplified methodology has now
been developed for the RIA model to allow an assessment of the effectiveness
of the current program and alternatives in reducing industry-related inter-
ference at POTWs. The approach chosen focuses on predicting the inhibitory
potential of industrial discharges on POTWs. No attempt was made to estimate
increased costs incurred by POTWs or the deleterious impacts on water quality
resulting from the occurrence of POTW inhibition.
To predict inhibitory potentials, the model is used to generate estimates
of industrial contributions to POTW influent under different pretreatment
options. These influent concentrations are then compared with threshold
values at which POTW processes are known to experience inhibition. Where the
influent concentrations of the selected toxic pollutants resulting from
industrial discharges exceed one or more of the inhibition onset values, the
POTW is deemed to have the potential to experience a process inhibition.
Table 2.6 presents the threshold values used to predict inhibition potential.
These were derived from the best judgement of EPA and JRB engineers.
As indicated in Table 2.6, inhibition onset concentrations for nine
pollutants are presented for two POTW processes - nitrification and activated
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Use or disclosure of proposal data is subject to the restriction on the Title page of this Proposal.
TABLE 2.6
ONSET CONCENTRATIONS FOR PROCESS INHIBITIONS AT POTWS
ONSET CONC. ONSET CONC.
FOR NITRIFICATION FOR ACTIVATED
PROCESS INHIBITION SLUDGE PROCESS
(mg/1) INHIBITION (mg/1)
ARSENIC
(AS)
N.A.
0.10
CADMIUM
(CD)
5.00
1.00
CHROMIUM
(CR)*
0.25
1.00
COPPER
(CU)
N.A.
1.00
MERCURY
(HG)
2.00
0.10
NICKEL
(NI)
0.50
1.00
T.RAT)
(PB)
0.50
0.10
ZINC
(ZN)
N.A.
5.00
TOTAL CYANIDE (CN)
0.34
0.10
* Including trivalent and hexavalent chromium species
N.A. Not Available
Source: MDSD Data; EPA Cincinnati Lab; and 304(g) Guidance Document Revised
Fretreatment Guidelines, Volume II, October 1981.
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sludge. As these processes are associated with secondary and tertiary
treatment plants, the model does not predict inhibitory potentials at 295
primary POTWs. The methodology assumes the presence of both of these
processes for the 1544 FOTWs which employ at least secondary treatment. For
each of these 1544 POTWs, the inhibitory threshold values for each of the
processes are compared to projected POTW influent concentrations.
If influent concentrations at each PCTW for any of the nine pollutants
exceed onset concentrations, a process inhibition could occur. By comparing
the number of POTWs predicted to experience inhibitions under different
regulatory schemes, conclusions can be drawn on the effectiveness of
pretreatment in protecting POTW operations. These results are presented in
Section 3.1.3 of this report.
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3.0 FINDINGS
This chapter presents revised findings on the impacts of toxic industrial
waste discharge on POTWs. The numerical results included in this chapter are
derived primarily from additional modeling efforts undertaken to incorporate
revisions suggested in public comments. These results are presented in tables
which correspond in form and numbering to those presented in the original RIA
report to facilitate a comparison of the new results.
The results in this chapter are based on model runs predicting three
levels of industrial pretreatment in place:
(1) Raw Discharge - assumes discharge of toxic industrial waste
with no industrial pretreatment
(2) Current Pretreatment - assumes the current level of
industrial pretreatment
(3) Full PSES - assumes level of industrial pretreatment
resulting from the application of 40 CFR 403 pretreatment
requirements, including all Categorical Standards.
These alternatives are cited throughout this chapter as "Raw Discharge,"
"Current Pretreatment," and "Full PSES," respectively for the comparison of
the six regulatory options considered in this report and its predecessor.
This chapter examines the environmental impacts of indirect toxic
discharges on water and sludge quality. In particular, numerical results
presented here indicate how toxic discharges to POTWs affect ambient water
quality, POTW effluent quality, POTW operations, and POTW sludge quality.
The analysis pays particular attention to the effectiveness of the Full PSES
alternative in mitigating each of the environmental impacts.
The interpretation of this analysis depends upon regulatory provisions
and guidelines which define acceptable levels of toxic discharges to the
environment. Unfortunately, ambient toxic limits are not in place in many
States. State sludge criteria are spotty and varied, and Federal sludge
guidelines exist for only a few of the disposal methods available to POTWs.
In addition, local sludge management decisions are controlled by site
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specific variables which could not be adequately generated in a national
model. As a result, it is impossible to report with great confidence the
absolute severity of environmental impacts. Still, the relative environ-
mental impacts of various pretreatment alternatives can be effectively
studied.
3.1 WATER POLLUTION
The POTW model was used to simulate the interaction among industrial
users, POTWs, and receiving water bodies. The analysis for this report was
conducted on the 1518 POTWs for which stream flow information was complete.
Numerical results were then scaled up to apply to 1839 POTWs out of a total
population of 2000 POTWs thought by EPA and the States to need pretreatment
programs. The model considered the water and sludge quality impacts of eight
(8) toxic metals, five (5) toxic organics, and cyanide.
3.1.1 Exceedances of Water Quality Criteria
The POTW model utilized a POTW-to-strearn dilution ratio to calculate the
ambient concentration of each toxic pollutant discharged from the POTW into a
receiving body. This projected ambient concentration is then compared to the
appropriate modified Federal water quality criteria to determine whether an
exceedance exists for the individual pollutant. In the original report, the
absolute values for the Federal water quality criteria were applied to
calculate exceedances. For this report, the Federal criteria have been
modified on a stream specific basis, where warranted, based on the indigenous
species and water hardness of each stream.
For two reasons, model figures for numbers of water quality criteria
exceedances should be taken as minimum values. First, the model assumes that
all POTWs having secondary treatment in place are meeting the standard
removals achievable at a well-operated secondary treatment plant. However, in
many instances POTWs may be achieving lower removals which would tend to bias
the results in favor of better water quality. Second, the model fails to
consider background, ambient levels of toxic pollutants. One would reasonably
expect additional exceedances of water quality criteria where background
ambient levels of toxic pollutants can be accurately measured.
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The tables provided in this section give estimates for number and
percentage of POTWs in exceedance of 100 percent and 50 percent of the
modified Federal water quality criteria. The former percentage, 100 percent,
posits the POTW as the sole contributor of the toxic pollutant to the
receiving water body. The latter figure, 50 percent, assumes that other
discharge sources contribute toxic pollutants at a rate sufficient to produce
ambient concentrations equal to 50 percent of the modified water quality
criterion. Consequently, a POTW discharging at a level corresponding to only
50 percent of the water quality criterion will nonetheless produce a pollutant
exceedance.
Tables 3.1(A) and (B) provide estimates of criteria exceedances for 100
percent and 50 percent of modified Federal water quality criteria,
respectively, when discharges are diluted by average annual stream flow
values. Both tables show large numbers of POTW exceedances for silver,
cadmium, copper, lead, and cyanide. Lesser but significant numbers of
exceedances are predicted for chromium, mercury, nickel, and zinc, and
insignificant numbers of exceedances for the five toxic organics. As
expected, there are greater numbers of exceedances for all toxic pollutants
when the POTW effluent is measured against only 50 percent of the modified
water quality criteria. These observations hold for both the raw discharge
and current pretreatment alternatives.
The results presented in Tables 3.1(A) and (s) differ from those
presented in Table 3.1 of the original RIA report. First, at both 50 and 100
percent of the aquatic life criteria, a greater percentage of POTWs are shown
exceeding those criteria than in the original report. The original report
also showed very few POTWs exceeding the water criteria for any pollutants
other than silver, cadmium, and cyanide, whereas Tables 3.1(A) and (B) show a
much larger percentage of POTWs violating copper, mercury, lead, and zinc.
Therefore the variety of pollutants causing water quality problems may have
been underestimated originally, as well as the number of POTWs experiencing
those problems. The differences in these results can be explained by the
inclusion of modified criteria values, which are more stringent than the
Federal criteria for copper and lead, and additional receiving stream flows
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TABLE 3.1
MODEL INDICATORS OF HATER QUALITY EXCEEDANCES USING MEAN FLOWS AND MODIFIED CRITERIA
(A)
POTW EXCEEDING 50Z OF AQUATIC LIFE WATER QUALITY CRITERIA
RAW
No. of
Exceedances
CURRENT
FULL PSES
PERCENT REDUCTION
Z No. of
POTWs Exceedances
Silver
1016
55
1014
Benzene
8
.4
4
Toluene
12
1
8
Cadmium
1347
73
1330
Chromium
292
16
216
Copper
803
44
749
Mercury
374
20
348
Nickel
183
10
115
Lead
869
47
803
Phenol
0
0
0
1,1,1-Trichloroethane
0
0
0
Bis(2 Ell) Phthalate
0
0
0
Zinc
395
21
325
Cyanide
704
38
672
(B)
POTWS
EXCEEDING
Silver
873
47
870
Benzene
2
0
1
Toluene
1
0
1
Cadmium
1221
66
1197
Chromium
193
10
121
Copper
663
36
602
Mercury
209
11
183
Nickel
134
7
67
Lead
729
40
643
Thenol
0
0
0
1,1,1-Tr ichloroethane
0
0
0
Bis(2 EH) Phthalate
0
0
0
Zinc
228
12
151
Cyanide
589
32
546
Z
POTWs
55
0
0
72
12
41
19
6
44
0
0
0
18
37
47
0
0
65
6
33
10
4
35
0
0
0
8
30
No. of
Exceedances
1009
2
5
1305
82
688
325
42
764
0
0
0
262
597
Z
POTWs
55
0
Q
71
4
37
18
2
42
0
0
0
14
32
Raw
to Full
1
75
58
3
72
14
13
77
12
0
0
0
34
15
Current
to Full
0
50
38
2
62
8
7
63
5
0
0
0
19
11
862
47
1
1
0
0
100
100
1
0
0
0
1161
63
5
3
18
1
91
85
528
29
20
12
152
8
27
17
10
.5
92
85
618
34
15
4
0
0
0
0
0
0
0
0
0
0
0
0
75
4
67
50
454
25
23
17
-------
which on average are lower than those originally modeled, thereby lowering
stresm dilution.
In order to better evaluate the effects of the Full PSES alternative, two
additional columns were presented in Tables 3.1(A) and (B) which show the
percentage reduction in pollutant exceedances as a measure of ambient water
quality improvement.
The figures for percentage exceedances reduction are less revealing as
they relate to the five (5) toxic organics. Because there are few toxic
organics exceedances to begin with, figures for percentage exceedances
reduction tend to be artifically high or low. It is difficult, at best, to
draw firm conclusions regarding the effects of full 403 pretreatment options
on these toxic organics with such a small population of initial criteria
exceedances.
The numerical results are considerably more revealing as they apply to
toxic metals. The figures for percentage exceedances reduction due to
application of Full PSES tend to be similar for both the 100 percent and 50
percent water quality criteria cases [see Tables 3.1(A) and (B)]. The Full
PSES alternative produced large percentage exceedances reductions for chromium
and nickel, lesser but significant reductions for copper, mercury and cyanide,
and insignificant reductions for lead, silver, and cadmium. These results
were consistent across the 100 percent water quality criteria cases for all
nonorganic toxic pollutants with the exception of zinc, which showed large
percentage reduction in the 100 percent water quality criteria case, and a
somewhat smaller reduction in the 50 percent case. These reductions are
somewhat misleading since the highest percentage reductions were for metals
with the lowest number of initial exceedances. These observations refer to
the eighth column of Tables 3.1(A) and (B), which reflect percentage exceed-
ances reductions in moving from current pretreatment to Full PSES.
Tables 3.2(A) and (B) present predictions of POTW water quality
exceedances when POTW effluent is diluted by 7Q10 low flows rather than
average annual flows. Not surprisingly, the number of POTWs and the per-
centage of all POTWs exceeding the modified water quality criteria increase
significantly. For example, the percentage of POTWs exceeding 50 percent of
i JRB Associates
3-5
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TABLE 3.2
MODEL INDICATORS OF WATER QUALITY EXCEEDANCES USING LOW FLOWS AND MODIFIED CRITERIA
(A) POTW EXCEEDING SOX OF AQUATIC LIFE HATER QUALITY CRITERIA
RAW CURRENT FULLPSES PERCENT REDUCTION
No. of X No. of X No. of * Raw Current
Exceedances POTWs Exceedances POTWs Exceedances POTWs to Ful1 to Full
Silver
Benzene
Toluene
Cudinium
Chromium
Copper
Mercury
Nickel
Lead
Pheuol
11l-Trichloroethane
Bis(2 EH) Phthalate
Zinc
Cyanide
(B)
Silver
Benzene
Toluene
Cadmium
Chromium
Copper
Mercury
tlickel
Lead
Phenol
I,I,1-Trichloroethane
Bis(2 EH) Phthalate
Zinc
Cyanide
146;
80
1465
80
1459
79
.4
36
2
12
.6
7
.3
80
42
36
3
26
1.4
18
.9
50
44
1635
89
1630
89
1621
88
.8
518
27
453
25
285
15
45
37
1286
70
1262
69
1222
66
5
3
894
49
863
47
833
45
7
3
328
16
244
13
112
6
66
54
1352
73
1300
71
1285
70
5
1
1
0
0
0
0
0
100
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
873
47
816
44
750
41
14
8
1223
66
1193
65
1156
63
5
3
POTWS EXCEEDING
100Z OF AQUATIC LIFE WATER QUALITY CRITERIA
1348
73
1348
73
1342
73
1
10
1
3
.2
1
0
91
67
11
1
8
1
5
.2
62
38
1558
84
1549
84
1534
83
1
1
332
17
252
12
72
4
77
71
1138
61
1099
59
1043
57
8
5
558
30
514
28
471
26
15
8
234
11
138
6
33
1.8
85
76
1230
67
1184
64
1164
63
5
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
495
26
421
22
268
14
46
36
1103
59
1075
58
1022
55
6
5
.5
.5
-------
the criterion value at current levels of pretreatment for cadmium increases
from 72 percent to 89 percent, for lead from 44 percent to 71 percent. The
numbers remain consistently higher when 100 percent of the criteria are used
to determine exceedances.
On the other hand, Table 3.2(A) and (B) indicate that implementation of
full pretreatment is somewhat less effective in reducing exceedances when low
flows are used to predict exceedances. For example, chromium exceedances are
shown to be reduced at Full PSES by 37 percent instead of the 62 percent pre-
dicted when annual flows dilute POTW chromium discharges.
3.1.2 Improvement in POTW Effluent Quality
Table 3.5 provides a measure of the improvement in POTW effluent quality
in moving from current pretreatment to Full PSES. The figures in the second
column are derived as the ratio of the difference between POTW effluent con-
centrations with and without pretreatment (i.e., Full PSES vs. current pre-
treatment) to POTW effluent concentration without pretreatment.*
Not surprisingly, the model predicts significant improvement in effluent
quality for most toxic pollutants, including seven of eight toxic metals and
all five toxic organics. For toxic metals, those experiencing the greatest
percentage reductions are nickel (51 percent) and chromium (74 percent); those
experiencing the least percentage reductions are silver (4 percent) and
cadmium (18 percent). Total metals are reduced 52 percent, total toxic
organics, 77 percent, through the application of the Full PSES alternative.
Also compared in Table 3.5 are the updated model predictions for effluent
quality improvement after pretreatment with those observed in the 40 POTW
study, selected case studies, and the original R1A report. Pretreatment is
revealed to significantly reduce the concentrations of toxic pollutants in
POTW effluent for all but two parameters. An anomaly in the data occurs for
cyanide and copper in the case studies and for copper in the 40 POTW study.
% improvement = current pretreatment effluent cone.-Full PSES affluent cone.
current pretreatment effluent concentration
3-7
JRB Associates
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TABLE 3.5
PERCENT IMPROVEMENT IN FOTW EFFLUENT QUALITY WITH PRETREATMENT PROGRAM
Pollutant
Parameter
40 POTW Study
Model
(Addendum)
Model
(Original RIA
Report)
Selected
Case Studies
Silver
(Ag)
0
4
6
n/a
Benzene
100
32
n/a
n/a
Toluene
50
31
n/a
n/a
Cadmium
(Cd)
33
18
26
53
Chromium
(Cr)
33
74
81
62
Copper
(Cu)
(7)
46
57
(56)
Mercury
(Hg)
n/a
31
29
65
Nickel
(Ni)
(9)
51
74
28
Lead
(Pb)
59
22
21
74
Phenol
100
35
n/a
1,1,1-Trichloroethane
69
96
n/a
n/a
Bis (2 EH)
' Phthaiate
0
28
n/a
n/a
Zinc
(Zn)
51
38
47
64
Cyanide
(CN)
16
n/a
n/a
(30)
Total Metals
26
52
63
36
Toxic Organics
75
77
70
99
(1) Percent improvements are derived from different cities with and without
pretreatment programs.
. JRB Associates
3-8
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While the model predicts consistent improvement for all toxic metal and
organic compounds, the percent improvement is slightly lower for metals and
slightly higher for organics in this report than predictions made in the
original report. Again, this difference can be attributed to the data and
methodological changes incorporated in this report.
3.1.3 Potential Interference with POTW Operation
Table 3.6 shows the model predictions for potential nitrification and
activated sludge process inhibitions at treatment plants attributable to toxic
metals discharged by industrial users to POTWs. For the purposes of this
analysis, the universe of POTWs is 1544 those plants of the 1839 which have
secondary or AWT capability. The analysis assumes the presence of these pro-
cesses at all 1544 POTWs, instead of determining the actual treatment pro-
cesses at each plant. Nonetheless, the results provide an indication of the
likelihood of process inhibitions due to industrial discharges at POTWs using
these treatment processes.
Results are presented for potential process inhibitions at three levels
of removal raw (assuming no industrial pretreatment), current (assuming a
moderate amount of industrial pretreatment currently in place), and Full PSES
(assuming that all categorical industries pretreat to comply with Pretreatment
Standards for Existing Sources). As evidenced in Table 3.6, the full pre-
treatment option is extremely effective in preventing potential inhibitions of
nitrification and activated sludge processes at POTWs.
3.2 SLUDGE CONTAMINATION
Paralleling findings for water quality improvement, the Full PSES alter-
native results in substantially improved sludge quality for most toxic
pollutants. Table 3.7 shows large reductions in chromium, copper, mercury,
nickel, and zinc concentrations (mg/kg, dry vt.), while producing less
significant reductions in silver and cadmium concentrations. Overall toxic
metal concentrations in sludge decline by 43 percent. Four of the five toxic
organic concentrations are reduced by approximately 30 percent through appli-
cation of the Full FSES alternative. Overall, the toxic organic concentration
is reduced by 75 percent. These results are similar to those predicted in the
3-9
JRB Associates
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Use or disclosure of proposal data is subject to the restriction on the Title page of this Proposal.
TABLE 3.6
POTWS PREDICTED TO EXPERIENCE INHIBITION POTENTIALS IN NITRIFICATION,
AND ACTIVATED SLUDGE PROCESSES*
NIT
R I F I C
A T I 0 N
% REDUCTION
CURRENT TO
RAW
CURRENT
FULL PSES
FULL PSES
ARSENIC
(AS)
N. A.
N.A.
N.A.
. N.A.
CADMIUM
(CD)
0
0
0
0
CHROMIUM
(CR)**
376
255
30
88
COPPER
(CU)
N.A.
N.A.
N.A.
N.A.
MERCURY
(HG)
0
0
0
0
NICKEL
(HI)
204
59
0
100
LEAD
(PB)
138
14
0
100
ZINC
(ZN)
N.A.
N.A.
N.A.
N.A.
TOTAL CYANIDE
(CN)
197
94
1
99
A C T I
V A T E D
SLUDGE
% REDUCTION
CURRENT TO
RAW
CURRENT
FULL PSES
FULL PSES
ARSENIC
(AS)
236
207
171
17
CADMIUM
(CD)
1
0
0
0
CHROMIUM
(CR)**
177
54
2
96
COPPER
(CU)
131
17
0
100
MERCURY
(HG)
0
0
0
0
NICKEL
(NI)
104
14
0
100
LEAD
(P3)
440
229
110
52
ZINC
(ZN)
20
2
0
100
TOTAL CYANIDE
(CN)
430
328
101
69
* Only secondary POTWs and AWTs are considered. (Total of 1544 secondary
POTWs and AWTs among 1339 POTWs examined.)
** Including trival-snt and hexavalent chromium species.
II.A. Not available.
3-10
JRB Associates
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C J
TABI.E 3.7
SI,URGE QUALITY WITH AND WITHOUT PR6TREATMENT FROM MODELING EXKRCISE
AVERAGE POTW SLUDGE QUALITY (mg/kg dry wt)
Silver (Ag)
Benzene
Tolueno
Cadmium (Cd)
Chromium (Cr)
Copper (Cu)
Mercury (llg)
Nickel (Ni)
Lead (Pb)
Zinc (Zu)
Phenols
11i-Trichloroethane
Bie(2 Ell) Plithalate
Cyanide (ON)
Total Murals
Toxic Organics
Without
Pretreatment
(Addendum)
45
297
183
36
633
468
2
119
166
838
399
29
2
u/a
2307
1342
Without
Pretreatment
(181 Report)
32
n/a
n/a
26
831
563
1.3
181
147
923
n/a
n/a
n/a
n/a
2704
913
With
Pretreatment
(Addendum)
44
213
132
31
227
270
1
46
141
552
269
1
2
n/a
1312
330
With
Pretreatment
(let Report)
32
n/a
n/a
21
222
274
60
132
547
n/a
n/a
n/a
n/a
1296
306
Percent
Improvement
(Addendum)
2
28
28
14
64
42
50
61
15
34
32
96
0
n/a
43
75
Percent
Improvement
(1st Report)
0
n/a
n/a
19
73
51
23
67
10
41
n/a
n/a
n/a
n/a
52
67
-------
original modelling results. In the initial report, toxic metal concentrations
were found to decrease by 52 percent, toxic organics by 67 percent.
Table 3.8 provides a comparison of the updated POTW model sludge results
with the previous model and local case study results. Upon the implementation
of pretreatment, all data sources indicate consistent improvement in sludge
quality for all parameters examined. The model results appear conservative
when compared with actual POTW experiences.
3-12
JRB Associates
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TABLE 3.8
PERCENT IMPROVEMENT IN SLUDGE WITH PRETREATMENT PROGRAM
Model
Pollutant Model (Original RIA
Parameter Case Studies (Addendum) Report)
Silver
n/a
2
0
Cadmium
20
14
19
Chromium
74
64
73
Copper
51
42
51
Mercury
50
23
Nickel
75
61
67
Lead
71
15
10
Zinc
51
34
41
Cyanide
n/a
n/a
n/a
Total Metals
49
43
52
Total Organics
n/a
75
67
Benzene
n/a
28
n/a
Toluene
n/ a
28
n/a
Phenol
n/a
32
n/a
1,1,1-Trichlorethane
n/a
96
n/a
Bis(2 EH) Phthalate
n/a
0
n/ a
5
3-13
JRB Associates
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Use or disclosure of proposal data is subject to the restriction on the Title page of this Proposal.
4.0 ANALYSIS OF PRETREATMENT OPTIONS
This chapter presents modelling results pertaining to the
environmental impacts and costs of different pretreatment options. These
pretreatment options are discussed at greater length in Chapter 4 of the
original regulatory impact analysis report. The tables in this chapter are
again numbered as they were in the original report to allow comparison.
The following options are examined in this chapter.
1. Existing Program - assumes full implementation of 40 CFR 403
pretreatment program, including mandatory Categorical Standards for
34 industries
2. Existing Program, Reduced Scope - assumes full 403 program, but
a reduced number of Categorical Standards; modelled with standard for
¦netal finishing industry only
3. Technology-Based Limits for POTWs - assumes development and
imposition of end-of-pipe toxic limits for POTW effluent, and
inclusion of these toxic limits in the POTW NPDES permit
4. Water Quality-Based Limits for POTWs - assumes development and
imposition of toxic limits for POTW effluent only in cases where
water quality standards are violated
5. Local Program for Documented Problems - assumes the develop-
ment of full 40 CFR 403 programs only in response to documented
problems at POTWs
6. Guidance Only - assumes the use of 40 CFR 403 regulation and
Categorical Standards as guidance only.
Option 2 in the original regulatory impact analysis considered existing 40 CFR
403 program with reduced scope of application. This option assumes applica-
tion of national Categorical Standard only to the metal finishing industry - a
major source of problem pollutants.
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JRB Associates _
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Finally, the tables in this chapter include waivers for Options 1, 2, and
3. A waiver system would allow a POTW to forego development of a complete 40
CFR 403 pretreatment program when no demonstrated water quality problems exist
at the POTW. For the purpose of this analysis, a POTW is exempted from pre-
treatment requirements if its discharges cause no exceedances of the modified
Federal water quality criteria.
4.1 ENVIRONMENTAL EFFECTS OF THE OPTIONS
This section describes the environmental effects of the options. As
discussed in Chapter 2, the results for the 2000 POTWs are currently based on
modelling the impacts of the options on 1839 POTWs. The remaining 161 POTWs
were not included because all of the available information showed that they
either had no industrial contribution or that they discharged into other
POTWs. Thus, the results of the 1839 POTWs should reasonably represent the
total impacts.
This section focuses on the impact of the options on the pass-through of
pollutants and the resulting effects on water quality as measured by
exceedances. The impact of the options on reducing the number or severity of
bypasses and upsets has not been quantified in the model.
4.1.1 Removal of Pollutants
Table 4.2 quantifies the following environmental effects: pounds of
toxic organics and toxic metals removed, percent reduction of toxic pollutants
in POTW effluent, and the percent reduction of toxic contaminants in effluent
sludge. The number of POTWs affected by an option strongly influences the
volume of pollutants removed and total cost of treatment. Where the appli-
cation of the option does not depend on water quality conditions, all 1839
POTWs are affected. If requirements apply only where water quality problems
are currently occurring, then the number of POTWs affected is reduced to the
model estimate of 1220. This can be compared to the original R1A report where
846 POTWa were predicted to be currently experiencing water quality problems.
As illustrated in Table 4.2, the RIA computer model predicts that 59,000
tons of organics and 15,000 tons of metals will be removed annually by POTWs
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JRB Associates _
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TABLE 4-2
IMPACT OF THE OPTIONS ON ENVIRONMENTAL RESIDUALS
OPTION
l.a Existing Program
1.b l.a with waiver
2.a Existing Program
Reduced Scope
2.b 2.a with waiver
3.a Tech-Based Limits
for POTW
3.b 3.a with waiver
4. Water Quality
Limits for POTW
5. Local Program for
Documented Problems
6. Guidance Only
PERCENT
IMPROVEMENT
ANNUAL TONS REMOVED IN POTW EFFLUENT
POTWs
AFFECTED ORGANICS METALS ORGANICS METALS
1839 58,887 18,561
1220* 38,865 12,250
1839 19,606 11,246
1220 12,940 7,426
1839 58,887 18,561
1220* 38,865 12,250
1220*
N.A.
N.A.
1220** <38,865 <12,250
76
76
25
<25
76
<76
N.A.
<76
1839
0-58,887 0-18,561 0-76
52
52
29
<29
52
<52
N.A.
<52
0-52
PERCENT
IMPROVEMENT
IN POTW
SLUDGE
43
<43
25
<25
43
<43
N.A.
<43
0-43
N.A. Not Available.
* Assuming no ambient concentration of toxic pollutants.
** Only includes those options that have water quality problems. Does not include
those POTWs that have upset or bypass problems, but no chronic water problems.
-------
under the existing 403 program. In addition there is a 77 percent improvement
in POTW effluent quality for organics, a 52 percent improvement for metals,
and a 43 percent improvement in sludge quality under the existing 403 program.
The remaining options result in similar environmental benefits depending on
the number of POTWs affected.
In general, the uniform national programs produce the largest reductions
in the volume of pollutants discharged into water bodies. This is primarily
because the requirements apply to more POTWs than do the other options. The
uniform national programs also significantly improve (on a percentage basis)
the quality of the POTW effluent discharge and the quality of the sludge.
While the options significantly reduce the volume of the pass-through of
toxic pollutants, the ultimate importance of these reductions depends on
resulting impacts on water quality. In the following subsection, the impacts
on water quality have been analyzed using exceedances as an indicator. Still,
there are important water quality impacts even where there are no immediate
exceedances since the reduction in pollutant discharges can reduce ambient
pollutant levels, facilitating the attainment of water quality objectives
downstream. Moreover, exceedances are thresholds values. Often, there are
benefits associated with reducing pollution even where there are no
exceedances, or where exceedances persist in spite of controls.
4.1.2 Effectiveness In Reducing Water Quality Exceedances
An exceedance is an indicator of the possibility that there may be water
quality problems associated with the discharge of a particular pollutant to
the environment. In the baseline analysis, current modelling runs predict
that 1220 POTWs will experience at least one exceedance at current levels of
pretreatment. The estimate of 1220 is low because it does not take into
account ambient levels of toxics in the receiving water or the contribution to
water quality degradation due to upsets or bypasses at a POTW. In addition,
the normalizing assumptions used in modelling industrial discharge loadings
and POTW removal efficiencies may affect the estimate of water quality
exceedances.
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JRB Associates
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Table 4.3 shows the reduction in the number of exceedances due to the
application of each of the options. About 34 POTWs have all exceedances
eliminated by most of the options. It is not known how effective Option 4
(water quality-based limits for POTW) would be. At least 34 POTWs would
have all exceedances eliminated through this option. Nonetheless, there
are limits to the extent that exceedances can be reduced through more
stringent controls on industry. Non-industrial sources can contribute
significant amounts of some pollutants, and where stream dilution is low,
these sources themselves may cause water quality exceedances. Since the
Federal back-up for Option 5 is the application of categorical pretreatment
standards, it is assumed that 34 municipalities will eliminate all of their
exceedances (as in Option 1).
These results can be compared to Table 4.3 in the original RIA report
which shows that each of the pretreatment options will result in a minimum of
61 POTWs having all of their pollutant exceedances eliminated. While on the
surface the reduction from 61 POTWs to 34 POTWs having all exceedances
eliminated seems to weaken the case for pretreatment, the figures can be
misleading. As discussed in Chapter 3, the current set of modelling runs show
more POTWs with exceedances for a wider variety of pollutants than in the
original report. This is due to the additional stream flows, lower dilution
and, in some instances, more stringent modified criteria. Since the number of
pollutant exceedances per POTW has increased, it becomes much more difficult
to eliminate all of the exceedances at any particular POTW. In fact, Tables
3.1(A) and (B) show that on a pollutant by pollutant basis pretreatment is
effective in reducing the number of exceedances.
4.2 COMPLIANCE COSTS OF THE OPTIONS
Table 4.4 shows the total annual compliance cost to industry and POTWs as
a result of each option. The industrial cost is divided into two components:
the additional cost of pretreatment and the cost of disposing of the addi-
tional hazardous waste that is generated. The total cost depends signifi-
cantly on the number of POTWs affected by each option. Excluding the metal
finishing only option, the total annual cost (for pretreatment) ranges from
approximately $1.2 to $1.8 billion. This is compared to original estimates of
4-5
JRB Associates
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TABLE 4-3
EFFECTIVENESS OF THE OPTIONS IN REDUCING EXCEEDANCES*
(Based on a total of 1,839 POTWs)
OPTION
l.a Existing Program
1.b l.a with waiver
2.a Existing Program,
Reduced Scope
2.b 2.a with waiver
3.a Tech-Based Limits
for POTW
3.b 3.a with waiver
4. Water Ouality
Limits for POTW
5. Local Program for
Documented Problems
6. Guidance Only
POTWs WITH
ONE OR MORE
INITIAL
EXCEEDANCES*
1220
1220
1220
1220
1220
1220
1220
1220
1220
POTWs WITH
ALL
EXCEEDANCES
ELIMINATED
34
34
17
17
34
34
>34
<34**
0-1220
POTWs WITH
0N2 OR MORE
EXCEEDANCES
REMAINING
1186
1186
1203
1203
1186
1186
<1186
>1186
* It is assumed that there is no ambient concentration of toxic pol-
lutants. If there is an ambient concentration of toxic pollutants, then
the number of initial exceedacces will be higher.
** Assumed to be limited to the effectiveness of the Federal back-up
(Option l.a). However, the actual effectiveness could be as high as for
Option 4 depending on the steps taken by the POTWs.
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TABLE 4-4
TOTAL COST OF THE OPTIONS FOR POTWs AND INDUSTRY
(Millions of 1981 dollars)
(Based on a total of 1,839 POTWs)
OPTION
l.a Existing Program
1.b l.a with waiver
2.a Existing Program,
Reduced Scope
2.b 2.a with waiver
3.a Tech-Based Limits
for POTW
3.b 3.a with waiver
4. Water Quality
Limits for POTW
5. Local Program for
Document Problems*
6. Guidance Only**
POTW COST
DEVELOPMENT ANNUAL
63
42
63
42
63
42
42
42
30
75
50
75
50
75
50
50
50
33
ANNUAL
INDUSTRY COST
PRE-
TREATMENT SLUDGE
1154
761
576
380
<1154
>761
>761
<761
0-761
586tt
387
302
199
<586
<387
>387
<387
0-387
TOTAL ANNUAL
COST
1815
1198t
953
629
<1815
<1198
>1198
<1198
<1198
* Assumed to be limited to the cost of the Federal back-up. Actually, the
costs could be higher depending on the local programs.
** The extent of local action in the absence of a Federal back-up is not known.
While the range reflects a maximum cost equivalent to the existing program
with waivers (l.b), the cost could be higher depending on local action.
t Assumes no ambient toxic pollutant levels.
tt This figure is currently being verified in new model runs. It is suspected
to be too high.
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between $0.9 and $1.9 billion in annual pretreatment costs. The cost of
pretreatment under the waiver options has increased due to the increased
number of POTWs initially experiencing water quality problems (i.e., 1220 vs.
846) while the cost has decreased slightly for the uniform options as a result
of data input changes discussed in Chapter 2.
The total municipal cost contains two components: the program development
cost (a one-time cost) and the annual cost of operating the program. Sludge
disposal costs for the POTWs are not affected by the improvement in sludge
quality because municipal sludges are not now subject to Federal regulations
that require more costly disposal. If there were sludge criteria that
resulted in more expensive disposal, then some of the options could lower the
POTW cost (and possibly the net total cost of both POTWs and industry),
potentially affecting the relative cost-effectiveness of the options.
4.3 SUMMARY
The RIA Addendum effort was undertaken to expand and refine the technical
basis for the Pretreatment RIA in response to public comments. New stream
flow data were incorporated, almost doubling the universe of streams for which
predictions, based on actual data, could be made. Revisions were made to a
number of key industrial data inputs determining industrial wasteloads, and
pretreatment compliance costs. The number of pollutants analyzed was expanded
to include selected toxic organic chemicals. New analytic methodologies were
employed to answer questions about the effectiveness of pretreatment in
preventing POTW interference, and in reducing water quality exceedances when
different water quality measures are employed as triggers.
The preceding sections have presented information on the nature of these
data and methodological changes, and the new findings resulting from this
work. Revised model predictions have been briefly compared with those
presented in the initial RIA report to provide a context for assessing the new
findings.
Predictions of the values for many of the measures chosen to evaluate
pretreatment in the RIA do change as a result of the data and methodological
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changes. More POTWs are forecast to have water quality exceedances.
Estimates of the percent improvement for metals in the POTW effluent and
sludge after pretreatment are somewhat lower, while estimates of the percent
improvement for toxic organics in effluent and sludge are higher in the RIA
Addendum. The cost predictions for the National Pretreatment Program (Option
1) are slightly lower due to decreases in industrial compliance costs, while
those for the options based on water quality waivers increase due to the
larger universe of POTWs predicted to experience water quality problems.
Overall, the results of the RIA Addendum work reinforce conclusions of
the original report concerning the need for and effectiveness of pretreatment
in controlling the impacts of industrial discharges of toxic pollutants on
POTWs. Industrial pretreatment is still predicted to reduce toxic loadings to
POTWs, to lessen the potential for interference at treatment plants, and to
decrease the presence and concentration of toxic pollutants in POTW effluent
and sludge.
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