-------
upstream of the POTW. The background level is obtained by sampling and
analysis of the receiving water upstream of the POTW considering that such
samples should be taken downstream of any other discharges to the receiving
water with allowance for a mixing zone. The use of mixing zones is appro-
priate for evaluating compliance with criteria in most States. Each State's
mixing zone policy is somewhat unique. State standards must be consulted to
determine appropriate application of a mixing zone so that proper calculations
of acceptable instream concentrations can be made. In addition, guidance on
determining suitable mixing zone dimensions and their applications is provided
in the Office of Water's Technical Support Document for Water Quality-based
Toxics Control (July 1985). This document gives specific recommendations on
the design of toxicologically based mixing zones and should be consulted when
analyzing effluent mixing conditions. The maximum level in the receiving
waters after the addition of the POTW discharge can then be compared with
water quality criteria or standards to verify that they will continue to be
met after revision of the categorical standards. An example of this water
quality calculation is found in the model removal credits application on page
C-10.
3-40
-------
i.
8.
9.
Table 3.3
Bibliography
U.S. Environmental Protection Agency. Federal Guidelines - State and
Local Pretreatment Programs. Vols. I, II, and III. EPA-430/9-76-Ol7a,
b, and c. January 1977.
2. U.S. Environmental Protection Agency. Fate of Priority Pollutants in
Publicly Owned Treatment Works. EPA-440/1-82-303. September 1982.
3. Anthony, Richard M., and Breimhurst, Lawrence H. "Determining Maximum
Influent Concentrations of Priority Pollutants for Treatment Plants."
Journal of the Water Pollution Control Federation. Vol. 53. October
1981.
4. Dyer, Jon; Feiler, Howard; and Bernick, Arnold. Handbook of Industrial
Waste Pretreatment, Water Management Series. New York: Garland Pub-
lishing Inc. 1981.
5. Eick, Richard W. "History of Priority Pollutants at the District and
Determination of Prohibitive Discharge Limits (PDL)." 2nd Edition.
Sanitary District of Rockford, Illinois. March 1982.
6. U.S. Environmental Protection Agency. Ambient Water Quality Criteria.
EPA-440/5-80. October 1980. ~~
7. U.S. Environmental Protection Agency. "Municipal Sludge Management-
Environmental Factors." Federal Register. 41, No. 108, pp. 22531, 22543',
June 1976.
JRB Associates. "How to Set Local Limits." Handout prepared for Pre-
treatment Seminars, sponsored by U.S. Environmental Protection Agency
under Contract No. 68-01 --5052. May 1982.
JRB Associates. "Assessment of the Impacts of Industrial Discharges on
Publically Owned Treatment Works." Prepared for U.S. Environmental Pro-
tection Agency under Contract No. 68-01-5052. November 1981.
10. U.S. Environmental Protection Agency. Determining National Removal
Credits for Selected Pollutants for Publicly Owned Treatment Works. EPA-
440/2-82-008. September 1982.
11. U.S. Environmental Protection Agency. Guidance Manual for POTW Pre-
treatment Program Development. Prepared for U.S. Environmental Pro-
tection Agency by JRB Associates under Contract No. 68-01-6514. October
1983.
12. U.S. Environmental Protection Agency. Guidance Document: Revised
Pretreatment Guidelines. Vol. I. Prepared for U.S. Environmental
Protection Agency. October 1981.
13. U.S. Environmental Protection Agency. Technology Transfer: Use and
Disposal of Municipal Wastewater Sludge. EPA-625/10-84-003, September
1984.
3-41
-------
Table 3.3
Bibliography (Continued)
14. U.S. Environmental Protection Agency. Technical Support Document for
Water Quality-based Toxics Control. July 1985.
15. U.S. Environmental Protection Agency. Methods for Measuring the Acute
Toxicity of Effluents to Freshwater and Marine Organisms.
EPA/600/4-85/013. March 19, 1985.
3-42
-------
4. Alternative Procedures Available To
Satisfy Application Requirements
The removal credits provision allows for alternative means and procedures
to demonstrate consistent removal where sampling and analysis data are not
complete or suitable for demonstrating consistent removal. Plant data may not
accurately reflect actual pollutant removals due to the effects of dilution by
nonindustrial wastes and the limits of analytical procedures such that
quantifiable influent and/or effluent concentrations cannot be measured.
However, the inherent complexities of any alternate methodology proposed by a
POTW necessitates both a clear justification for its use, and careful
evaluation by the Approval Authority.
POTWs need to be aware that alternative means and procedures may only be
used with the concurrence of the Approval Authority, and that these alternate
procedures will also be subject to review by EPA Regional staff and EPA
Headquarters Office of Water Enforcement and Permits. As such, POTWs are
advised to carefully consider their decision to pursue this option, and to
consult with the Approval Authority regarding the method's appropriateness at
the earliest possible stage. A discussion of each of the alternatives
available is presented below.
4.1 Use of Historical Data For POTW Removals
Complete sampling and analytical data for 12 sets of influent and
effluent samples may not provide enough data points to accurately predict the
plant's consistent removal rate. In another instance, the POTW may have
4-1
-------
sampled for only six months but wants to apply for removal credits as soon as
possible. Where applicable, POTWs may wish to rely on available historical
data concerning the pollutants in question. In many instances, these data
were gathered for other reasons (i.e., pretreatment program development, water
quality or sludge quality studies, or as the basis for the design of replace-
ment equipment or plant expansion). This type of database can be included to
calculate POTW removal rates of the toxic pollutants providing samples were
collected at proper locations, with proper care and attention to sampling and
analytical techniques and at approximately equivalent frequencies (at least
one per month).
In evaluating whether historical data are usable for calculating
consistent removal rates, the applicant must determine whether sampling and
analytical techniques were in conformance with current requirements. Sampling
and analytical protocols, particularly for some toxic pollutants, are
periodically refined and improved. It is possible, therefore, that historical
data were collected under different protocols than are now required and that
the sampling techniques were inconsistent with those needed for removal
credits, which must be based on 24-hour composite samples (except in those
cases where the type of pollutant being sampled dictates grab samples be
used). Similarly, the POTW should verify that analytical techniques asso-
ciated with historical data were in conformance with Federal requirements for
priority pollutant sampling, with detection limits that will be suitable for
removal credit calculations.
Another major factor is that the POTW must ensure historical data are
respresentative of the wastestream currently entering the plant. This
includes such considerations as changes in the community served by the POTW
(especially with regard to industrial users) and treatment plant operational
parameters and processes. The historical data must be carefully evaluated for
these considerations before it is used for calculation of consistent removal.
In regard to the IDs of the system, then the POTW must demonstrate to the
Approval Authority that industrial contributors continue to discharge similar
quantities and concentrations of toxic pollutants of concern. In the last ten
4-2
-------
years, advances in industrial technology, new processes and compounds, energy
and water conservation, economic incentives to recover pollutants which were
previously discharged, and an increased awareness of environmental issues have
caused many industrial facilities to change their internal processes and
operations, often dramatically altering flow rates and wastewater character-
istics. Before a POTW relies on its own historical sampling data, industrial
consistency should be demonstrated by showing that the industrial community
served by the POTW (in particular, the sampling results of IU monitoring) has
remained consistent over that period. The relative proportions of industrial
vs. residential/commercial flow during the historical period and at present
should also be indicated. Other indicators for industrial dischargers, such
as employment statistics or water usage, are not by themselves adequate to
provide this verification. If such verification cannot be provided, then the
POTW may be limited in its use of historical data.
fr
Another prerequisite for use of historical data is that the POTW
demonstrate its operations have not changed since the data were collected. It
is relatively straightforward to indicate that the POTW unit operations are
the same but it is also important to note whether POTW operational changes may
have affected toxic pollutant removals. For example, the addition of chemi-
cals or varying the dose rate of chemicals can dramatically affect the removal
of metals with only a minimal effect on BOD or TSS removals. Changes in
wastewater pH may affect operations as well as removal of some toxic pol-
lutants, particularly metals. Similarly, volatilization of certain organic
priority pollutants may be a function of a variety of factors including
turbulence, aeration horsepower supplied, and temperature. If there have been
substantial modifications or additions to the POTW since the period that the
historical data was collected, then historical data is probably invalid.
4.2 Use of Alternative Sampling Designs
Some POTWs may want to propose an alternative sampling program based on
factors that would result in more than 12 equally spaced samples being used in
calculating consistent removal. Situations such as a POTW with seasonally
discharging industries or POTWs that experience significantly different
weather conditions (e.g., temperature, precipitation) may justify a change in
4-3
-------
sampling frequency. In these cases, it may be more appropriate to take a
different number of samples during one time of the year than another. Plants
with these different seasonal conditions may need to take a higher number of
samples during a particular season. The affected lUs may provide technical
insight into appropriate alternative sampling designs. However, regardless of
the total number of samples collected, all sampling data must be used and at
least one sample each month is required. Furthermore, the data should be
handled such that the resulting removal rate is representative of the entire
year. In some cases this may require that different numbers of samples each
month be averaged and then these averaged monthly influent and effluent values
themselves be averaged to compute the representative removal rate.
4.3 Use of Treatability Studies or Removal Data From
Similar Treatment Plants To Demonstrate Removal
i
Some POTWs may not be able to detect the pollutants in their influent or
effluent for which removal credits are being sought. This is particularly
true of systems where industrial contributions of priority pollutants are
small relative to the total flow into the treatment plant and also in the case
of many of the organic priority pollutants. These POTWs, with the Approval
Authority's concurrence, may take advantage of provisions in the regulations
which allow for use of alternative data sources from treatability studies or
data transfer from a similar POTW. Again, interaction with the lUs serviced
by the POTW may help define possible alternative data sources.
4.3.1 Treatability Studies
If treatability studies are to be used, the POTW must demonstrate that
the removal rates obtained apply to the full-scale POTW. The criteria that
would need to be addressed and demonstrated in the POTW's application for
removal credit authority include the following:
• Similar influent pollutant characteristics
• Attempts to collect actual pollutant removal data were unsuccessful
• Consistent influent and effluent sampling were uninfluenced by recycle
streams
4-4
-------
• Proper sampling and analytical techniques were employed
• Operation of the pilot plant was in the same manner as the facility
being modeled.
This last item requires the POTW to demonstrate that treatability studies
were set up properly and operated with the same constraints as the full scale
facility. POTWs interested in performing treatability studies are encouraged
to consult the Approval Authority for more specific information on setting-up
and operating such a study.
4.3.2 Transfer of Data From Similar POTWs
Another alternative provided by the regulations for demonstrating
consistent removal is to rely upon data from similar treatment plants. While
this alternative may be difficult, the POTW must attempt to demonstrate that
these data are accurately transferable for the pollutants of concern. Trans-
fer of data for one pollutant to another pollutant is especially difficult.
EPA, through its many sampling programs and industry studies, has found very
few occurrences of reliable "indicator" pollutants.* Therefore, it may be
difficult to show that a pollutant removal rate at a POTW with the same basic
operation as the applicant plant will be equivalent to the removal rate for
the pollutant at the applicant: plant.
Before the pollutant data is transferred to the applicant POTW, the POTW
should evaluate such issues as the chemical form of the pollutant, acclima-
tion, synergism and antagonism of the various pollutants, type arid location of
recycle streams within a plant, and any other factors that may contribute to
the problem of reliable data transfer from one plant to another. For example,
the removal of toxic pollutants is complicated because removal depends largely
upon the percent of the pollutant in soluble versus suspended form (most
measurements only report the "total" metal concentration) and the removal
mechanisms available for a particular pollutant. Since toxic pollutants are
*An indicator pollutant is an easy-to-measure pollutant that will predict
either the occurrence or removal of a more difficult to measure pollutant.
4-5
-------
primarily associated with industrial contributors, the nature of the pollutant
composition is likely to be industry specific. Thus, the ratio of soluble to
suspended concentrations for any pollutant may vary, even when two cities have
a similar total pollutant concentration.
A POTW that wishes to demonstrate that sampling results at another POTW
are directly transferable for use in the calculation of removal credits should
address the following questions:
• Whether the plant unit operations and operational characteristics
(such as SRT, MLSS, aeration rate, etc.) are similar
• Whether the composition of industrial dischargers (including type of
pollutants, concentrations and flow volume) is approximately the same
for both plants, and POTW influent wastewater characteristics
(including daily load fluctuations and the effects of infiltration/
inflow) are similar
• Whether the variability in performance of the two plants, at least as
measured in conventional pollutants, is comparable
• Whether raw water characteristics at both plants are similar
• Whether the sampling and analytical techniques used to generate the
data to be used are satisfactory for the purposes of removal credit
calculation, and would satisfy all of the requirements of the
regulations
• Whether the data accurately reflect the current industrial composition
and the current POTW operations that are to be portrayed
• Whether the pollutants present in sludge are comparable.
4-6
-------
5. Sampling and Analytical
Requirements
5.1 Sampling Methods
The removal credit regulation requires at least 12 representative samples
of the POTW's influent and effluent taken at approximately equal intervals
throughout one full year (historical data or an alternative sampling design
may be used under certain circumstances with the Approval Authority's con-
currence). A POTW may accept assistance from its industrial users in the form
of financial support to cover the cost of additional sampling, and technical
support to aide the POTW in selecting appropriate sampling equipment and
techniques, and perhaps even to contribute employee time and labor. It is
ultimately the affected industrial users that benefit from the granting of
removal credit authority and therefore the Ill's should be encouraged by the
POTW to participate in applying for and maintaining the removal credit.
Typically, laboratory analyses must be based on composite samples unless grab
samples are more appropriate. The regulation does not attempt to specify when
grab samples are more appropriate, but rather provides general guidance in
Appendix E of the regulations along with a description of the methods.
Appendix E of the regulations recommends that influent and effluent data be
obtained by 24-hour flow-proportional composite sampling. It is recommended
that effluent sample collection be delayed to compensate for hydraulic
detention within the treatment plant. The detention period is defined as the
hydraulic residence time through the plant without consideration of recircu-
lating flows. The Approval Authority may require detention time compensation.
5-1
-------
An exception to composite samples is where the pollutants being analyzed
cannot be held for an extended period because of biological, chemical or
physical interaction which may take place after sample collection and affect
the results. For these pollutants, such as cyanide, phenol, and a number of
toxic organics, grab sampling should be employed. The collection of influent
grab samples according to the suggested procedures should precede the collec-
tion of effluent samples by approximately one detention period.
When collecting or examining existing analytical data, it is important to
determine whether the influent and effluent samples are suitable for cal-
culating removal credits. A common problem with the use of analytical data is
that influent samples do not always accurately characterize the POTW influent.
This can be particularly true where a POTW is considering use of a historical
data base and the samples were not collected for the primary purpose of cal-
culating an accurate percent removal. Many POTWs contain internal plant
recycle lines from various sludge processing operations back to the headworks.
Sampling downstream from recycle flows is often suitable for routine POTW
activities or to calculate unit process loading rates, but data -obtained from
such a sample point are not appropriate to calculate removal credits. Thus,
POTW sampling of influent at a convenient or perhaps often used location that
includes these recycle flows will substantially overstate percent removals.
In order to calculate an accurate percent removal, influent samples must be
taken upstream of all recycle flows. Because of the importance of this issue,
the POTW should address it in the application (a flow diagram is often useful)
and the Approval Authority must verify that pollutant removals were correctly
calculated.
A problem that may arise for some POTWs is that sampling prior to all
recycle flows is not necessary for routine treatment plant operations.
Therefore, some POTWs will have a piping system that is arranged such that
obtaining a sample prior to all recycle flows may be almost physically
impossible. Where a POTW can demonstrate that it falls into this category, it
will be necessary to obtain the correct value for the influent concentration
to the treatment plant by conducting a mass balance around the point that can
be sampled, subtracting out the pollutant concentration attributable to
recycle flows. For example, the piping configuration may be represented as
below:
5-2
-------
Fr, Cr
Ft, Ci #1
#2 Fs, Gs
where Fr is a recycle flow (in units of volume per time) with a pollutant
concentration of Cr. The sampling location necessary to obtain an accurate
influent sample for calculating consistent removal is location #1. If it is
not possible to sample at location #1, the concentration at that point would
have to be calculated by measuring the flows (Fr and Fs) and concentrations
(Cr and Cs) at locations #2 and #3. The proper influent pollutant concen-
tration (Ci) would then be calculated as follows:
Ci
(Fs)(Cs) - (Fr)(Cr)
Fs - Fr
This method of obtaining the influent pollutant concentration is not the
preferred method and should only be used when absolutely necessary. The POTW
should obtain the prior concurrence of the Approval Authority before investing
time and money into the sampling and analysis to calculate the influent
concentration by this method.
5.2 Analytical Methods
As specified in the final removal credit rule, the POTW is to use the
analytical techniques prescribed in 40 CFR 136 for sample analysis. The POTW
may use alternate analytical methods if the Approval Authority concurs or has
established alternate methods. Analytical techniques for certain pollutants
may not be contained in 40 CFR 136 or the technique may be inappropriate. In
such cases an alternative analytical technique may be used with the concur-
rence of the Approval Authority. Other sources of analytical techniques
include Standard Methods for the Examination of Water and Wastewater;
Fifteenth Edition, published by the American Public Health Association,
Washington, D.C.; Handbook for Sampling and Sample Preservation of Water and
Wastewater (EPA Publication No. 600/4-82-029); and Methods for Chemical
Analysis of Water and Wastes (EPA Publication No. 600/4-79-020).
5-3
-------
-------
Part II:
Guidance for the Approval Authority
The revised removal credit regulation defines roles and responsibilities
of the Approval Authority in the removal credit process. These can be divided
into three general areas:
• Reviewing and approving POTW proposals to satisfy application require-
ments
• Reviewing the removal credit application and taking appropriate action
• Ongoing review and monitoring of the POTW to determine that consistent
removals and other application requirements continue to be achieved.
Each of these roles and responsibilities will be discussed in more detail in
the following chapters. Some Approval Authority functions are straight-
forward; others require that Approval Authority officials exercise technical
or policy discretion. Where appropriate in these chapters, guidance will be
included concerning the Approval Authority's exercise of that discretion.
Upon submission, a POTW application may be found to be inadequate in some
areas. The Approval Authority reviewer should give careful consideration to
any weaknesses in an application and then provide specific and constructive
guidance to POTW officials to correct any noted problems. By providing clear
and specific comments to the POTW, the reviewer can save the POTW time in
revising its application and ensure that subsequent resubmissions respond
adequately to the reviewer's concerns.
-------
-------
6. Review of Removal Credit
Applications
6.1 Genera!
This section addresses the Approval Authority's review of a removal
credit application. The specific information required in a removal credit
application is described in Part I of this manual. The review of most items
submitted in an application is straightforward. These items and a brief
description of the criteria to be met are listed below:
• Calculations of consistent removal and revised discharge limits -
Check to make sure that appropriate data were used and the calcula-
tions were done correctly. The technical issues associated with this
aspect of the application teview are particularly important.
• Pretreatment program certification - Check to make sure the POTW has
an approved pretreatment program or qualifies for an exception.
• Sludge management certification - Check the requirements applicable to
the POTW's method of sludge use or disposal to verify that the
requirements match those stated in the application and that granting
removal credits will riot cause a violation of these requirements.
• NPDES permit limit certification - Check the NPDES permit limits and
compliance file to determine if granting the credits will cause the
POTW to violate NPDES permit limits and conditions. If it has been in
violation in the recent past, an assessment of the potential for a
reduction or increase in future violations should be made.
The Approval Authority conducting the review should also consider
historical information and records of the POTW's operation and compliance
status in making the determination to grant a removal credit authorization.
6-1
-------
Such information may include: the POTW's pretreatment program submission;
operational and effluent data for the wastewater treatment plant(s); 301(h)
waiver applications; pretreatment program audit reports; and the NPDES permit
compliance file.
6.2 Procedural Requirements
The Approval Authority must review the application in accordance with the
procedures in 40 CFR 403.11. These are the same procedures used to review
pretreatment program submissions. After the Approval Authority has completed
review of the application, it can approve or deny the application, or it can
authorize a lower removal credit than the POTW sought. Additional discussion
of the procedural requirements of 40 CFR 403.11 may be found in Guidance
Manual for POTW Pretreatment Program Development, EPA, Office of Water
Enforcement and Permits, October 1983.
6.3 Consistent Removal Rate
The Approval Authority should conduct a review of data in the removal
credit application to determine if the removal rates are reasonable, con-
sidering the following:
• Treatment plant processes employed
• Sludge generation and disposal method used
• Maintenance of a consistent quality effluent in compliance with the
POTW's NPDES permit limits.
In addition, the removal rates demonstrated by other similar POTWs can be
compared with the removal credits being requested. This type of comparison,
using the data discussed below, is intended to serve only as a guide for a
review of POTW influent and effluent data to obtain a general idea of the
removal rates which are considered typical of many conventional secondary
biological treatment plants.
6-2
-------
In 1978, EPA began a project which is commonly referred to as the "40
POTW Study," formally titled Fate of Priority Pollutants in Publicly Owned
Treatment Works. Volumes I and II (EPA 440/1-82/303, September 1982). The
Agency initiated the study to determine the removal of toxic pollutants in 40
well-operated POTWs that were meeting secondary treatment effluent limits.
The scope of the project included 6-day, 24-hour sampling at the 40 POTWs,
representing a variety of municipal treatment technologies, size ranges, and
percentages of industrial flow. The types of treatment plants sampled
included activated sludge plants, trickling filter plants, pure oxygen
activated sludge plants, an RBC plant, an aerated lagoon, and four treatment
plants that have both activated sludge processes and trickling filters in
parallel modes. The information discussed below is from the 40 POTW Study and
focuses on metals. Information on organic priority pollutants was much less
consistent, and particular attention should be given to removal credits
requests for these. As more information concerning the behavior of organic
pollutants in POTW treatment systems becomes available, EPA will issue further
guidance.
Removal data from the 40 POTW Study for the nine toxic metals detected in
POTW influents 50 percent or more of the time are summarized in Table 6.1.
Presented in the table are percent removals for two subgroups of analytical
data: removals where the priority pollutant average influent concentration
was greater than zero, and removals when the plant average influent concen-
tration was significantly above the pollutant's detection limit. For this
table, "significantly above the detection limit" was defined as four times the
most frequent detection limit to minimize the effect of the detection limit on
calculating percent removals. The number of data points for each subgroup is
indicated by N.
Table 6.1 shows that 50 percent of the POTWs sampled achieved minimum
priority pollutant metal removals ranging from 35 percent to 97 percent. The
purpose of the 40 POTW Study was to measure the effectiveness of well operated
POTWs in removing priority pollutants considering a range of treatment
processes and influent characteristics. Thus, one of the selection criteria
for identifying the POTWs sampled during the study was that an engineering
6-3
-------
Table 6.1 Summary of Minimum
Percent Removals^ Achieved by Secondary Treatment
Average Influent > 0 Average Influent > Lower Limit'^'
Parameter
Zinc
Cyanide
Copper
Chromium
Nickel
Silver
Mercury
Lead
Cadmium
Percent of Plants
N<2> 50 75 80 90
40
40
40
40
36
36
35
34
29
77
59
82
76
35
95
86
97
93
64
36
58
66
18
82
65
74
46
55
33
56
64
17
79
61
58
39
44
5
46
48
8
66
25
35
4
N
40
40
40
35
22
2
9
3
12
Percent
of Plants Lower
50 Limit (ug/l)'4>
77
59
82
76
32
94
86
81
92
80
4
8
; 20
40
20
800
200
8
(2)
Removals based on average influent and effluent concentration.
N » Number of plants meeting average influent criteria „ ,
Lower limit chosen significantly above (approximately 4 times) the
parameter's detection limit. ,
Mercury in ng/1.
6-4
-------
judgement be made that POTWs were well operated. Approval authorities may not
conclude that all POTWs applying for removal credits are well operated and
capable of attaining the range of removal found in the study. Conversely,
factors such as operation, design, sludge settling characteristics, etc., may
combine to produce a removal rate higher than the range shown for some
pollutants. The 40 POTW Study values for removal rates for priority pollutant
metals are presented in this manual solely to give Approval Authorities the
benefit of the results of an extensive study of priority pollutant removal in
POTWs. The values should not be presumed to be the highest or lowest rates of
consistent removal a given POTW can demonstrate. A removal request for a
removal credit signficantly higher than that found in the 40 POTW Study,
however, should alert an Approval Authority to scrutinize the factors at the
particular POTW which appear to demonstrate an unusually high removal rate.
If the application does not contain sufficient information to support the
removal rate, the Approval Authority must request additional information to
fully analyze the reasons why such removals may be achievable at that POTW.
The results of the 40 POTW Study should not be used to deny a request for
removal credit authorization higher than the removals found in the Study.
Similarly, if a POTW is only able to demonstrate a consistent removal lower
than the range found in the Study, the Approval Authority should not assume an
error was made in the application process. The applying POTW may not maintain
the type of operating procedures that were determined to be good operating
practices in selecting candidate POTWs for the study or for other reasons may
not be able to achieve removals found in the study.
The 40 POTW Study also analyzed removals for selected conventional and
priority toxic pollutants at the various treatment plants sampled. Among the
treatment plants examined, trickling filters, activated sludge, the RBC, and
the pure oxygen systems achieved good removals of conventional pollutants and
most of the measurable priority pollutants. At those plants that had acti-
vated sludge and trickling filter systems in parallel, the activated sludge
process appeared to remove slightly more priority pollutant metals and
organics than the trickling filter. However, for some parameters, the
trickling filter process achieved higher removal rates.
6-5
-------
Primary treatment was less effective than any secondary treatment for
conventional and priority pollutant removal. It should be noted, however,
that the primary effluent samples from this study are probably not represen-
tative of treatment plants employing only primary treatment since the primary
treatment plants considered in this study in all cases preceded secondary
treatment. Secondary treatment plants (which generate a much greater volume
of sludge than primary plants) return many of the sludge processing side
streams to the primary tanks. This practice often causes the influent to the
primary tanks to be much higher in organic loading than the influent to a
typical primary treatment plant. Nevertheless, primary treatment removed from
10 to 57 percent of priority pollutant metals based on the plant influent and
the primary effluent.
6.4 Sludge Management Certification
The Approval Authority must review the POTW's method of sludge disposal
and its ability to comply with any applicable Federal, State, or local laws or
regulations governing specific disposal methods. The method of sludge
disposal determines the applicable pollutant criteria. For those P'OTWs
utilizing more than one method of disposal, all applicable criteria must be
complied with. Currently, there are three primary methods of disposal for
which there are major Federal regulations: landspreading, landfilling, and
incineration. These regulations are shown in Table 6.2. In addition to these
Federal regulations, all applicable State and local requirements must be met.
During the review of a removal credit application, the Approval Authority
should confirm that all applicable regulations have been properly considered
by the POTW to determine their effect on sludge management options. The
various regulatory agencies at the Federal and State level have requirements
for or in most cases will at least address the following pollutants: arsenic,
boron, cadmium, copper, chromium, lead, mercury, nickel, PCBs, and zinc. Once
all applicable disposal regulations are identified, the POTW should have
calculated the effect of applying the removal credit on the pollutant
concentration in the sludge. Step-by-step procedures outlining this
development were provided in Section 3.5 of this manual. The Approval
Authority must then review the POTW's information to determine that adequate
6-6
-------
Table 6.2
Major Federal Regulations Relating to
Sewage Sludge Disposal
Sludge Disposal
1.
2.
3.
4.
Landspreading
a, Food-Chain Application
b. Non-Food-Chain
Application
Land Disposal
a. Solid Wastes
( non-hazardous )
b. Hazardous Wastes
c. PCBs Disposal
Incineration
a. New Stationary Sources
of Air Emissions
b. Hazardous Pollutants
c. Hazardous Wastes
d. PCBs Disposal
Ocean Dumping
Regulation
40 CFR 257
40 CFR 257
40 CFR 257
40 CFR 260
et seq.
40 CFR 761
40 CFR 60
40 CFR 61
40 CFR 260
et seq.
40 CFR 761
40 CFR 220
et seq .
Date of
Promulgation
9/79
9/79
9/79
5/80
5/79
10/75
10/75
5/80
5/79
1/77
Authority
RCRA/CWA
RCRA/CWA
$
RCRA/CWA
RCRA
TSCA
CAA
CAA
RCRA
TSCA
MPRSA
Key: RCRA = Resource Conservation and Recovery Act
CWA = Clean Water Act
TSCA = Toxic Substances Control Act
CAA = Clean Air Act
MPRSA = Marine Protection„ Research, and Sanctuaries Act
6-7
-------
protection of the sludge is maintained with the implementation of removal
credits.
6.5 NPDES Permit Certification
The removal credit regulation requires that an application contain a
certification that, by granting removal credits, the POTW will not violate its
NPDES permit limits and conditions. The Approval Authority should verify that
the POTW has fully considered the potential impact of revised discharge limits
on its ability to meet its NPDES requirements. The POTW should document, in
its application, that it has adequately considered two major impacts:
• Interference with its operations
• Its ability to meet specific discharge limitations in its permit.
In contrast to the situation described above, some NPDES permits will
already contain limitations for toxic pollutant discharges because of State
water quality standards or as a result of a wasteload allocation on a water
quality limited stream. Where removal credit authority is sought for
pollutants contained in the POTW's NPDES permit, the POTW must demonstrate
that loadings of the pollutant that result from granting the removal credit
will not exceed the capacity of the its treatment system to remove those
pollutants to the levels required in the NPDES permit. The application should
contain sufficient documentation to allow the Approval Authority to evaluate
the analysis. The Approval Authority should approve the application only
after the POTW has fully and accurately demonstrated by calculations the
capacity of the POTW treatment system to remove the anticipated loadings of
pollutants limited in the NPDES permit. Again the technical information
prepared as part of the development of local limits should provide this
information.
As an aid in the review, the Approval Authority will generally have
historical NPDES monitoring data that the POTW has submitted. The past
history of the plant in maintaining a consistent quality effluent, therefore,
can be reviewed by the Approval Authority. This review may give an indication
6-8
-------
of the plant's operational stability and its ability to maintain the consis-
tent removal rate specified in the application. The data to be reviewed might
include, where available, effluent data, treatment plant operating informa-
tion, and NPDES violation incidents. If a particular plant has consistently
met its effluent limits and experienced few upsets or operational problems,
then it is likely the plant will be able to maintain consistent removal..
However, if the plant has had a series of operational problems and been unable
to consistently comply with its effluent limits, it will be less likely to
achieve consistent removal of toxic pollutants. For this latter case, only a
removal rate lower than the rate requested in the application might be
authorized by the Approval Authority.
For the case of a PQTW applying for removal credit authority even though
NPDES compliance may not be achieved until categorical industries comply with
the adjusted categorical standards for the pollutant applied for, the Agency
has taken the following position. The POTW will not receive removal credit
authority until compliance with its NPDES permit for the pollutant applied for
is demonstrated. This does not apply in instances where the NPDES permit
violation is unrelated to the pollutant for which removal credits are being
sought.
6.6 NPDES Permit Modifications
The pollutant discharge limitations, requirements and conditions
contained in 3 POTW's NPDES permits are key to both the removal credit
application process, and 'enforcement of the demonstrated removal rate. There
are two types of revisions which are necessary to the success of this process.
The Approval Authority should include in the permit:
• Discharge limitations for the parameters for which removal credits are
sought
• A requirement that the POTW maintain its demonstrated consistent
removal rate
• Sampling and reporting requirements.
6-9
-------
Discharge limitations should be incorporated into a POTW's NPDES permit
for each parameter for which a removal credit is sought. These permit
limitations serve a dual function; providing a broader technical basis for the
development of local limits and assuring the protection of receiving stream
water quality. Inclusion of the demonstrated consistent removal rate in the
NPDES permit provides both documentation and the necessary mechanism for any
later enforcement actions. The procedure by which the POTW must demonstrate
consistent removal should also be included in the revised permit. Calculation
and reporting of a rolling twelve month average would provide such a demon-
stration. Sample NPDES permit modification language for removal credits is
provided for guidance in Appendix D of this manual.
The Approval Authority is encouraged to provide guidance to NPDES and
Pretreatment delegated States so that permit modifications proceed as
expeditiously as possible. Delegated States should consider developing the
necessary removal credit agreements and permit modifications as an activity
during their 106 planning procedures. It is suggested that simultaneous
public notices be issued for approval of the removal credit application and
the permit modifications. Since some States may have delegation for NPDES
authority only, the Regions should make the preparations necessary to ensure
coordinated actions. Because of the workload of permit modifications in most
NPDES delegated States, there may be a significant lag between removal credits
approval and the permit modifications. To avoid having this situation, the
approval letter, by itself, may require special sampling and should be
workable and enforceable without an immediate permit change.
6.7 Review of POTW Proposals to Use Alternative
Methods of Demonstrating Consistent Removal
As discussed in Section 3.2.2 and Chapter 4, any alternate method of
demonstrating consistent pollutant removal requires the concurrence of the
Approval Authority. Proposals for the use of an alternate method to demon-
strate consistent removal should be submitted for concurrence in advance but
may be contained as a part of the application for removal credit authority.
It is clearly advisable that POTWs submit such proposals prior to their
application rather than assuming that alternate- procedures will be approved.
6-10
-------
Such advanced approval will minimize the chance that a POTW will invest a
large amount of time and resources pursuing an application strategy that the
Approval Authority may find deficient.
Proposals to use alternate methods for demonstrating consistent removal
fall into two general categories:
• Proposals to vary the sampling and analysis plan based on at least 12
samples over a one-year period at approximately equal intervals, or
• Proposals to demonstrate consistent removal using data other than
actual plant influent: and effluent sampling results.
The requirements of such proposals are discussed in Chapters 4 and 5 and will
not be repeated here. Additional review guidance, however, is provided-.
6.7.1 Proposals to Vary the Sampling and Analysis Plan and
Use of Historical Data
The general rule is that each application for removal credit authoriza-
tion must be supported by at. least 12 influent and effluent samples taken at
approximately equal intervals over one year. The purpose of the requirement
is to ensure that data are collected that fairly represent yearly and seasonal
variations in treatment system loading and efficiency. POTWs may have
previously collected data that they feel accurately represent influent and
effluent pollutant concentrations but such data may not have been collected
over a year at approximately monthly intervals. The removal credit regulation
provides flexibility to allow such data to be used to satisfy the sampling and
analysis requirements in whole or in part. Thus, a POTW may have results of
six existing sample analyses collected at what they feel is an appropriate
time interval and propose to collect only six additional samples.
In reviewing such proposals, the Approval Authority should first evaluate
(1) the reasons for using an alternative sampling scheme and (2) whether the
POTW has submitted sufficient information upon which to base an independent
determination that the proposal will adequately represent the seasonal and
yearly variations in POTW loading and performance. Where historical data are
used that may have been collected for another purpose, the Approval Authority
6-11
-------
should be satisfied that sampling procedures, analytical procedures, sampling
frequencies, and other relevant factors are consistent with sampling and
analysis methods to establish removal credits. These and other issues
associated with use and evaluation of historical data were discussed in more
detail in Section 4.1.
Alternatively, a sampling plan that includes 12 samples obtained over
approximately equal intervals during a one-year period may not be practical or
representative of yearly and seasonal variation. Some POTWs may include
significant industrial users that conduct seasonal businesses. In such cases,
alternative sampling designs may be necessary to meet the objectives of the
regulations. When reviewing alternative sampling programs, the Approval
Authority should note that many POTWs cannot representatively illustrate
consistent removal with only 12 data pairs. In these instances, it may be
necessary to require that a larger number of samples be collected.
6.7.2 Proposals to Demonstrate Consistent Removal by Methods
Other than Influent and Effluent Sampling
The effects of dilution by nonindustrial wastes and the limitations of
available analytical methods may combine to make it difficult or impossible to
demonstrate consistent removal using influent and effluent sampling. Such
situations will occur when analytical results for a pollutant are below the
detection limit for a given analysis. In such cases, removal may be occur-
ring, but the analytical method may be unable to demonstrate it. Under such
circumstances, the regulation provides for alternate procedures to demonstrate
consistent removal. The Approval Authority must concur with the use of the
alternate procedures. The specific procedures were discussed in Chapter 4.
In considering whether to concur with a specific method of demonstrating
consistent removal, the reviewer should be guided by the principles underlying
the revised removal credit regulation. Consistent removal should be demon-
strated for a specific POTW, its treatment process, and its wastewater
loading. Whether the POTW proposes to calculate demonstrated removal based on
historical data, treatability studies, demonstrated removal at other facili-
ties, or other methods, the reviewer must decide whether adequate justifica-
tion has been provided to demonstrate that: (1) the alternate data accurately
6-12
-------
represents the removal capability of the specific POTW and; (2) the alter-
native method is based on facts and comparisons that can adequately represent
the removal capability of the POTW applying for removal credits. Without
requiring a POTW to justify that alternate data are representative of its
plant and its treatment system can the use of alternate data sources becomed a
variation of the previously proposed national removal credit concept. EPA has
determined that such generalized removal credits are not technically sound and
are not permitted by the Clean Water Act.
6.8 Additional Considerations for Reviewing
Applications of POTWs With 301(h) Waivers
Generally, NPDES permit limitations for POTWs are based on the
capabilities of secondary treatment technology. Section 301(h) of the Act
authorizes POTWs that discharge into marine waters to apply for NPDES permits
based on less stringent treatment than secondary treatment for biochemical
oxygen demand and suspended solids removal and pH control. Among the
regulatory requirements for evaluating such 301(h) waiver requests is that a
detailed analysis be conducted of the impact that less stringent limitations
will have on the marine receiving waters.
When reviewing the removal credit application from a POTW with. a NPDES
permit based on a 301(h) waiver, the Approval Authority should be aware of the
extensive impact analyses conducted to support the waiver from secondary
treatment requirements. Pollutant discharge at levels greater than what would
be expected due to implementation of removal credits could require reevalua-
tion of conclusions that were drawn based on the proposed discharge presented
in the 301(h) application and the assumption that categorical standards would
be achieved. For example, the 301(h) impact analysis may have concluded that
a proposed discharge would riot cause a sufficiently significant impact to
require a specific NPDES permit limitation when categorical standards are met.
With removal credits, however, a sufficient impact may be found. It is the
applicant's responsibility to demonstrate whether the implementation of
removal credit will affect the proposed discharge's compliance with all 301(h)
criteria. As a result, when an Approval Authority reviewer considers an
application for removal credits from a POTW that has an NPDES permit based on
6-13
-------
a 301(h) waiver, it will be necessary to consult the 301(h) decision document.
The reviewer should also solicit input from the Approval Authority staff
responsible for the 301(h) waiver for the POTW.
6-14
-------
7. Modification or Withdrawal of
Removal Credits
When removal credits are authorized, the POTW's demonstrated consistent
pollutant removal becomes an enforceable part of its NPDES permit. The
Approval Authority must periodically review and evaluate the POTW's compliance
with removal credit provisions to ensure that all the conditions are being
met. This review should be conducted at least annually (such as when annual
reports required by the removal credits provision are received). The Approval
Authority may require more frequent reporting at its discretion. An evaluation
of compliance with most of the conditions is straightforward. The POTW must
maintain and enforce an approved pretreatment program, ensure that the sludge
disposal method meets all regulatory requirements, ensure that the NPDES
permit limits and conditions are not violated, and verify that the POTW is
maintaining its consistent removal rate. The removal credits regulation
requires that removal credit authorization be modified or withdrawn if any of
these conditions are not met. In particular, if the POTW's actual removal
efficiency becomes "consistently and substantially lower" than the removal
credit authorized, the credit authority will be modified to allow a lower
removal rate or totally withdrawn. However, even if a consistently and
substantially lower removal rate cannot be demonstrated by the procedures
below, the Approval Authority may take an enforcement action against any
removal credit permit violation.
7-1
-------
7.1 POTW Monitoring and Reporting Frequency
POTWs that have been granted removal credit authority must submit a
compliance report to the Approval Authority at least once per year. This
report must contain analytical data for samples taken of the influent and
effluent for the reporting period. Samples must have been collected at least
once per month unless otherwise specified by the Approval Authority.
The Approval Authority has the discretion to require a more frequent
compliance demonstration through additional reporting. For example, this
compliance determination could be based on a periodic rolling 12-month
average. Examples of situations that possibly warrant more frequent sampling
and reporting include the following:
• In the early stages of program implementation, the Approval Authority
may conclude that once per year reporting of consistent removal data
is inadequate to track the continuing performance of some or all
POTWs. A good policy may be to initially require all POTWs with
removal credit authority to report more frequently than once per year.
After a compliance history has been established, the Approval
Authority might conclude that POTWs with a good compliance record can
be adequately tracked with once per year reports. POTWs having more
difficulty maintaining their consistent removal rate would continue to
report more frequently until their compliance records improved or the
Approval Authority gathered sufficient data to consider modifying or
withdrawing removal credit authority.
• Where a POTW has experienced problems complying with its NPDES permit,
or has a history of system upsets, but was able to demonstrate to the
Approval Authority that it has corrected those problems, the Approval
Authority may require more frequent reporting to ensure that problems
have, in fact, been corrected.
• Where a POTW treats a high fraction of industrial wastes subject to a
removal credit or discharges into a sensitive receiving water, rela-
tively frequent reporting might be made a necessary condition of
obtaining removal credit authority.
• Where the POTW used treatability studies or other alternative data as
a supplement to or in lieu of plant influent/effluent data to demon-
strate consistent removal, more frequent reporting of actual sampling
data should be required. In this case, additional data collected in
the months following approval will allow the Approval Authority to
continue to assess the POTW's actual removal rate and, where neces-
sary, modify or withdraw the POTW's removal credit authority.
7-2
-------
7.2 Criteria
From the reports submitted by the POTW, the Approval Authority must
determine if the POTW has continued to achieve the removal rates claimed in
its application. If reports submitted by the POTW or studies performed by the
Approval Authority at the POTW show the removal rates to be consistently and
substantially lower than the approved rate, then the Approval Authority has
cause to modify or revoke the POTW's removal credit. While EPA intends to
issue detailed guidance on determining what constitutes "consistently and
substantially lower," the following guidance is provided in the interim.
Part of the Approval Authority's decision concerning whether or not the
removal rate has dropped consistently and substantially involves using best
professional judgment. When the removal rate data contained in the POTW's
compliance report are shown to, deviate significantly from the original
consistent removal data, then the Approval Authority should evaluate the cause
of the deviation, and its impact on the approved rate. If the reported
removal rate for all pollutants is still greater than or equal to the approved
removal credit, no modifications are necessary. However, if the reported
removal rate is below the approved removal credit, then the Approval Authority
must determine if it is significant enough to warrant action to modify or
withdraw the approved removal credit. As mentioned previously, EPA intends to
issue guidance for evaluating reported removal rates with approved removal
rates. In any instance, an enforcement action can be taken against any
removal credit permit violation by the Approval Authority.
For POTWs that have been given authority to grant conditional removal
credits, authorization may be withdrawn after appropriate notice if the POTW
fails to comply with the conditions for applying and maintaining that authori-
zation. These conditions include operation of an approved pretreatment pro-
gram, maintaining consistent removal, and complying with NPDES permit limits
and conditions and sludge disposal requirements. Conditional removal credits
may also be terminated for certain industrial users by the POTW or the
Approval Authority. The circumstances where this would occur are those in
which the industrial users have failed to submit the proper information
required by the Baseline Monitoring Report or have violated other pretreatment
requirements.
7-3
-------
7.3 Procedures and Schedule
After the Approval Authority has decided that the withdrawal of a POTW's
removal credit authority or modification of that credit is warranted, the
Approval Authority must take the following actions:
• Issue a public notice of the intent to withdraw/modify the POTW's
removal credit authorization
• Provide a public comment period of at least 30 days
• Provide an opportunity for interested persons to request a public
hearing.
The above procedures are required by 40 CFR 403.11(b)(l) and (2). The mailing
list for the public notice must include, at a minimum, the POTW and the
industrial users to whom revised discharge limits have been applied.
If the Approval Authority decides withdrawal or modification is justified
(after the above actions have been completed and a public hearing has been
held or denied), a public notice must be published in the same newspaper as
the tentative notice was published. The Approval Authority must also notify
and provide the basis for that decision to the POTW, all industrial users to
whom revised limits have been applied, and each person who has requested
individual notice. Following the above notices and official withdrawal or
modification, all industrial users that had received the removal credit will
be subject to the modified (if the removal credit was modified) or to the
categorical pretreatment standard discharge limits (if the removal credit was
withdrawn). The industrial users must achieve compliance with these more
stringent limits within a reasonable time as established by the Approval
Authority, not to exceed the period of time allowed in the applicable
categorical pretreatment standard (i.e., typically three years).
For example, if a categorical pretreatment standard provided for a
compliance period of three years from the date of promulgation, an industrial
user affected by the modification or withdrawal of a removal credit could be
granted a maximum compliance period of three years from the date of modifi-
cation or withdrawal of the removal credit. However, the Approval Authority
7-4
-------
can establish a shorter period for compliance after considering the necessary
adjustment to existing treatment technology or the amount of additional
treatment that must be installed.
7-5
-------
-------
Appendix A
Removal Credit Provision Final Rule
-------
-------
31212
Federal Register / Vol. 49, No. 151 / Friday, August 3, 1984 / Rules and Relations
ENVIRONMENTAL PROTECTION
AGENCY
40 CFR Part 403
EFHL 2557-7]
General Pretreatment Regulation* for
Existing and New Sources; Removal
Credits
AGENCY: Environmental Protection
Agency.
ACTION; Final rule.
SUMMARY: On September 28,1982, the
Environmental Protection Agency (EPA)
proposed extensive revisions to the
removal credits section of the General
Pretreatment Regulations (40 CFR Part
403). EPA proposed these changes to
make the removal credits provision
simpler and more workable. After
considering all significant comments
submitted on the proposed changes, EPA
is today promulgating in final form the
revised removal credits section of the
pretreatment regulations.
DATES: This regulation shall become
effective September 17,1984. For
purposes of judicial review, this
regulation is issued at 1:00 PM eastern
time on August 19,1984.
FOR FURTHER INFORMATION CONTACT!
Craig Jakubowics, Permits Division (EN-
336), U.S. Environmental Protection
Agency. 401M St. SW., Washington.
D.C. 20460, (202) 428-4793.
SUPPLEMENTARY INFORMATION:
L Background
On June 26,1978, EPA promulgated, in
40 CFR Part 403, the General
Pretreatment Regulations which
established mechanisms and procedures
for controlling the introduction of
wastes from industry and other non-
domestic sources into publicly owned
treatment works (POTWs) (43 FR 27736).
Following promulgation, several parties
brought actions in Federal court
challenging these regulations. Pursuant
to the terms of a settlement agreement
entered into by EPA and some of the
parties to the litigation, the Agency-
promulgated amendments to the General
Pretreatment Regulations for Existing
and New Sources on January 28,1981 (46
FR 9404). These amendments were
originally scheduled to take effect on
March 13.1981. However, acting under
the President's memorandum of January
29,1981, EPA postponed the effective
date until March 30,1981 (48 FR 11972,
February 12.1981). On March 27.1981,
the Agency indefinitely suspended the
effective date of the amendments
pursuant to Executive Order 12291 (46
FR 19936. April 2,1981).
On October 13.1981. EPA terminated
the indefinite postponement of the
January 1981 amendments and
established January 31,1982, as their
effective date (46 FR 50502). On the
same day, EPA invited comment on a
proposal that the effective date of the
amendments be further postponed (48
FR 50503). Most of the 1981 amendments
were allowed to go into effect on
January 31,1982. However, a few of the
amendments, including the removal
credits provision, were further
postponed (47 FR 4518, February 1.
1982). On July 8,1982. the United States
Court of Appeals for the Third Circuit
held that EPA's original indefinite
uuspension violated the Administrative
Procedure Act, and directed EPA to put
all the pretreatment amendments, :
including the removal credits section,
into effect retroactive to March 30,1981
(Natural Resources Defense Council v.
EPA. 683 F. 2d 752 (3d Cir. 1982)).
An important part of the June 1978
General Pretreatment Regulations and
the January 1981 amendments was the
section governing removal credits
(section 403.7). That section was
designed to implement a 1977
amendment to section 307(b)(l) of the
Clean Water Act (CWA), which allows
a POTW to provide industrial users with
a "credit" (in the form of reduced
pretreatment requirements) for removal
of pollutants by the POTW. Industrial
users which qualify for such a credit are
allowed to discharge larger quantities of
regulated pollutants to the POTW than
would otherwise be allowed by the
applicable categorical pretreatment
standard. The removal credits section
established the conditions under which
IKDTWs would obtain authority to grant
removal credits and provided the means
by which these removal credits should
be determined. -
Notwithstanding the streamlining
included in the 1981 amendments, the
removal credits provision was still
criticized by some as being so
burdensome and unworkable as to
discourage POTWs from applying for
removal credit authority. In fact this
removal credit rule was one of the
provisions of the General Pretreatment
Regulations challenged, albeit
unsuccessfully, in the pretreatment
litigation (National Association of Metal
Finishers (NAMF) et al. v. EPA. 719 F.
2d 624 (3d Cir. 1983)). In addition to the
general allegation of unworkability,
several specific aspects of the regulation
were attacked. Industry groups and
some POTWs were critical of the
requirement that a POTW have an
approved pretreatment program, arguing
that this condition for removal credit
authority went beyond any requirement
specified in | 307(b)(l) of the Clean
Water Act. These groups also asserted
that unless a POTW maintained its
initially approved removal rates, the
ongoing POTW monitoring and reporting
of its removals could result in a change
of its removal rates and the industries
adjusted discharge limits every six
months, thus creating a "moving target"
that would make continuing compliance
for industrial users difficult, if not
impossible, to achieve. The overflow
requirements also were objected to as
impossible to-comply with. All these
arguments were rejected by the U.S.
Court of Appeals for the Third Circuit in
upholding the 1981 removal credits
provision.
In response to the criticisms of past
removal credits rules, on September.28,
1982, EPA proposed further
modifications to the removal credits
section to create a clearer, more flexible
and workable provision. EPA today is
promulgating in final form a revised
removal credit regulation, incorporating
some of the modifications proposed in
September 1982.
IL National Removal Rates
The most controversial proposed
change to the removal credits section
was the provision for "national removal
rates." This would have permitted a
qualified POTW to rely on national
removal rates developed by EPA. rather
than on rates established through the
collection of data by the POTW to
demonstrate its actual removal
performance. Some commenters
responding to the September 28,1982,
proposal supported the proposed
national removal rates. Some of these
commenters contended that the
proposed national credits concept was
too restrictive in its application because
it only applied to certain eligible
POTWs (i.e., those achieving secondary
treatment levels and fulfilling certain
other requirements). Other commenters
argued that the proposed national rates
were too low, and thus would not grant
adequate relief to a POTW's industrial
users. Another group of commenters
argued that the proposed national
removal credits approach was illegal.
These commenters also argued that the
national credits concept was unsound as
a matter of policy because the proposed
removal rates exceeded the actual
removal capability at approximately
50% of the eligible POTWs.
Because of the controversy over the
national removal credits policy issue
and the challenge to the legality of this
approach, EPA has reevaluated the
national removal credits concept. The
Agency has concluded, upon
A-l
-------
Federal Register / Vol. 49. No. 151 / Friday. August 3. 1984 / Rule» and Regulations 31213
reconsideration, that Congress intended
that a removal credit be granted-for a
particular pollutant only to the extent
that a particular POTW can
demonstrate that it removes the
pollutant. The language of the statute,
buttressed by the legislative history.
indicates that removal credits are to be
based upon case-by-case removal
determinations, rather than upon a
nationally determined rate. Moreover.
EPA has concluded upon
reconsideration that, on balance, policy
considerations in implementing the
pratreatment program envisioned, by
Congress favor the case-by-case
determination of removal credits rather
than reliance apon national credits.
Under section 307 (b) and (c) of the
CWA, EPA is required to promulgate
pretreatment standards for the
introduction of toxic pollutants into a
POTW. These standards must be
designed to prevent the discharge of any
pollutant which interferes with, passes
through or otherwise is incompatible
with a POTW.
In 1977, Congress amended section
307{b](l) of the CWA to specifically
provide for removal credits. The
relevant language of section 307(b)(l) is
as follows:
If. in Ihe case of any toxic pollutant * * *
Introduced by a source into a (POTW], the
treatment by such works removes all or any
part of such toxic pollutant and the discharge
from such works does not violate that
effluent limitation or standard which would
be applicable to such toxic pollutant if it
were discharged by such source other than
through a [POTW], and does not prevent
sludge use or disposal by such works in
accordance with section 405 of this Act then
the pretreatment requirements for the sources
actually discharging such toxic pollutanU
into such (POTW], may be revised by the
owner or operator of such works to reflect the
removal of such toxic pollutant by such
works.
(Emphasis added). As the highlighted
language indicates, Congress intended
that a removal credit be granted only
where some removal, whether by
treatment or incidentally, by a particular
POTW is actually achieved at the
POTW.
A clear indication of this statutory
intent is found in the legislative history
of the Clean Water Act In the House
debate on the conference report
accompanying the Act, Congressman
Roberts stated that any credit to an
industrial user of a POTW must "reflect
the degree reduction of * * * [a]
pollutant achieved by the treatment
works." (A Legislative History of the
Clean Water Act of 1977 (hereinafter
cited a§ Lsgis. Hist, vol. 3, p. 343)).
Farthennore. hi th« Senate debate on
the Conference report, Senator Muskie
stated that "EPA and the permitting
States may approve case-by-case
modifications of the national
pretreatment standards—or local
credits—for documented pollutant
removals attained by a [POTW]." (Ligis.
Hist., vol. 3, p. 461). In fact. Congress
rejected the idea of establishing a
national credit due to the variability
among POTWs1 abilities to remove a
particular pollutant. Aa stated in the
Senate report on the 1977 proposed
amendments to the Act:
Another reason for minimizing the
consideration of removals in the development
of national pretreatment standards is that the
performance of treatment works on industrial
waste, except in those few cases where the
system is specifically designed to treat a
certain type of industrial waste, is extremely
variable. Data that have been presented to
this committee indicate that secondary
treatment removal efficiency for metals
varies between 10 and 70 percent. Variability
of such magnitude makes the assumption of
specific levels of removal, when setting
national standards, almost impossible.
(Legis. Hist., vol. 4. p. 691).
Finally, in the recent decision of the
United States Court of Appeals for the
Third Circuit in the pretreatment
litigation (NAMFet al. v. EPA. supra),
the court stated that section 307 (b) (1)
of the Act allows for a removal credit
only in those instances in which a
POTW is actually removing a pollutant.
The court also cited and assigned
significance to the legislative history
discussed above in support of its
reading of the statute. Based on the
statutory language, legislative history,
and recent court decision just discussed.
EPA believes it lacks legal authority to
establish national removal credits.
Equally important EPA has carefully
reconsidered national removal credits in
light of the statutory policy underlying
the general requirements to promulgate
pretreatment standards to prevent
interference, pass through and sludge
problems. While EPA continues to
recognize the administrative advantage
inherent in the use of national removal
credits, the Agency believes that case-
by-case determinations of actual POTW
removals is the only reliable means to
assure that credits granted are
consistent with actual POTW removals.
This in turn will assure that removal
credits will not result in a net reduction
of treatment by the POTW and its
regulated industrial users.
Based upon all the above
consideration, EPA has decided not to
promulgate national removal credits.
EPA has retained the basic regulatory
approach embodied in previous removal
credits provisions that authorize
POTWs to apply for removal credits
based upon case-by-case
demonstrations. However, as discussed
below, the Agency has modified the
regulation in some respects to make the
program more efficient and to j?rant as
much certainty as possible to POTWa
that are granted removal credit
authority and industrial users mat rely
upon removal credits.
III. Discussion of tha Final Removal
Credit Provision
Today's final rute requires POTWa to
demonstrate consistent removal by
sampling their actual individual plant
performance, as was required under the
1978 and 19B1 regulations. However.
POTWs may use historical sampling
data or use sampling schemes other than
the 12 month sampling scheme generally
prescribed. Important changes to the
regulation are the elimination of the
complicated adjustment for combined
sewer overflows and the simplification
of approval procedures, including the
addition of a provision that allows a
POTW to apply for removal credit
authority at any time, A detailed
discussion of all the changes is provided
below.
Section 403.7(a)—Introduction
This introductory paragraph remains
almost the same as in the September 28.
1982, proposal. For the reasons
discussed above, however, the
provisions pertaining to POTWs
applying for the national removal rates
have been omitted. In addition, the
definition of "Sludge Requirements" in
§ 403.7(a)(lHii) now includes a reference
to the Marine Protection, Research and
Sanctuaries Act (MPRSA), which was
inadvertently omitted in the proposal.
Otherwise, the introduction is the same
as at proposal.
Section 403.7(a) sets out the
definitions and ground rules under
which POTWs can obtain authorization
to give removal credits. Paragraph (a)(2)
makes it clear that the POTW has
complete discretion in deciding whether
to award removal credits. A POTW
qualifying for removal credit authority
may decline to give removal credits at
all to a certain industrial category or to
one or more industrial users in a
category, or it may award a lower
removal credit than it is authorized to
give. In addition, paragraph (a)(2) now
stipulates that once a POTW has been.
authorized to grant removal credits and
has extended those credits to the
appropriate industrial users, it will be
the industrial users that actually will
calculate their revised discharge limits.
As proposed, the POTW was obligated
to perform this task for all its industrial
A-2
-------
31214
Federal Register / Vol. 49. Mo. 151 / Friday. August 3. 1984 / Rules and Regulations
users receiving removal credits. Because
calculating revised limits merely
requires inserting the authorized
removal credit and applicable
categorical pretreatment standard into
the mathematical formula specified at
paragraph (a)(4) of the regulation, the
Agency believes that it will be simpler
and less administratively burdensome if
each affected industrial user performs
this function for itself rather than relying
on its POTW to do so. This also applies
if, at some future time, the removal
credits a POTW is authorized to grant
are modified.
Paragraph (a)(3) outlines the five
prerequisites for a POTW to obtain
authorization to give removal credits.
The POTW must: (1) Apply for and
receive authorization to grant removal
credits: (2) demonstrate consistent
removal; (3) have an approved local
pretreatment program or qualify for the
exception to this requirement; (4) meet
all applicable sludge requirements; and
(5) continue to comply with all its
NPDES permit limits and conditions.
Paragraph (a)(4) identifies the basic
equation from which one calculates the
revised discharge limits. This equation
is the same as the one contained in the
1978 regulations and the 1981
amendments.
Paragraph (a)(3)(iv) also advises
POTWs that if granting removal credits
forces them to incur greater sludge
management costs than they would
incur in the absence of granting removal
credits and the POTW is eligible for
Federal construction grant funding
under the Clean Water Act, EPA will not
pay for the additional sludge
management costs. The final removal
credits section, like the 1981
amendments, also provides that the
POTW must remain in compliance with
local, state and Federal requirements
applicable to the sludge management
method employed by the POTW after
granting removal credits. The following
table, reprinted from the September 28,
1982, proposal, summarizes the EPA
regulations which potentially apply, at
present, to sludge disposal.
MAJOR FEDERAL REGULATIONS RELATING To SEWAGE SLUDGE DISPOSAL
Sludg* dfeptMd
1. Untapmdn*
«. Food-cn«n «pu«c«lkjii
2. Lend dtapOMfc "'"*
«. Sana wxtM fmnhranfau^
b. Kazan**!* «MIIH ,.
c. PCS-t dtar»«i —
3, Incineration: '"" -'
a. NOT ttltonary teurcM <* + tmttiorm
D. HazantaiM onttuMm.. ' "
r Harafrtrna i^ai** M ,
d. PCS'. *-f*~f
4. Oomn Oumfiing
Regulation
40 CFR Part 257
40 CFH Part 257. _
40CFHP*rt2S7 . .
40 CFH Part 781 „
40 CFR Part 60 _ ....
40 CFR PirtSI
40 CFH Part* 260 « uq
40 CPU P«rt 2JQ « ttq
Date of promulgation;
9/79 RCRA/CWA.
9/79 RCRA/CWA.
5/80 RCHA.
5/79 TSCA.
10/75 CAA.
10/75 CAA.
5/80. 1/81 RCRA.
5/79 TSCA.
1/77 MPRSA.
MPRSA-Mann. Protection, Rmvch. and Sonctuaria* Act.
Only rarely will POTW sludge be
considered a hazardous waste subject to
the requirements of 40 CFR Part 260, et
seq. or exhibit a sufficiently high
concentration of PCBs to become
subject to the requirements of 40 CFR
Part 781. EPA anticipates, therefore, that
POTWs applying for removal credits
will usually by subject only to the
landspreading and land application
requirements of 40 CFR Part 257; the
sludge incineration requirements of 40
CFR Parts 60 and 81; or the ocean
disposal requirements of 40 CFR Part
220 etseq. (in addition to State-and local
requirements).
Also included in the final regulation.
at 5 403.7(a)(3)(iv). is a provision
designed to accommodate POTWs that
are not presently in compliance with
sludge requirements applicable to their
chosen sludge disposal practice but will
be in compliance when the industrial
users install the technology needed to
comply with their categorical
pretreatment standard(s) (as adjusted
by the removal credit). The provision is
intended to benefit industrial users who
otherwise would be unable to get a
removal credit until after they had
already installed the technology
necessary to meet the full pretreatment
standard. A POTW that can
demonstrate that it will be compliance
with any applicable sludge requirements
when the industrial users meet the
applicable pretreatment standard (as
modified by the removal credit) will be
deemed to have satisfied the sludge
requirements provision.
Section 403.7(a)(3)(v) of the final rule
also requires, as a prerequisite to
removal credit authorization, that the
POTW remain in compliance with its
NPDES permit limits and conditions
after giving removal credits. As
proposed, a POTW was only required to
maintain compliance with any toxic
limits in its permit for which it is
granting a removal credit. Today's final
rule clarifies the Agency's intent that
removal credit authority not be granted
if a violation of the POTW's permit
limitations or conditions would result
For example, if a POTW's section
301(h) waiver application has been
approved, the POTW's NPDES permit
mci-y contain conditions to assure that
the POTW maintains water quality that
protects a balanced indigenous
population of aquatic biota. If the
Approval Authority determines that
granting removal credits would cause
such permit conditions to be violated.
then the removal credit application must
be denied.
Section 403.7{a)(3)(v) can also be
satisfied in a manner analogous to that
provided in § 403.7(a)(3)(iv). That is, the
POTW can demonstrate that it will be in
compliance with its permit limitations
and conditions when industrial users
comply with their categorical
pretreatment standards, as modified by
the removal credit.
Section 403.7(a)(3)(iii) and (d)—Local
Pretreatment Program Requirement and
Exception Thereto
Paragraph (a)(3)(iii) of the final rule is
the same as proposed on September 28.
1982. and for the most part similar to its
counterpart in the 1981 general
pretreatment amendment. It provides
that a POTW must develop a local
pretreatment program as a prerequisite
to obtaining removal credit
A-3
-------
Federal Register / Vol. 49. No. 151 / Friday, August 3. 1984 / Rules and Regulations
31215
authorization unless development of
such a program is not required by Part
403.
Paragraph (d) provides that a POTW
can grant "conditional" removal credits
prior to approval of its local program if
the POTW submitted a complete
application for pretreatment program
approval, meeting all the requirements"
of § I 403.8 and 403.9 of the General
Pretreatment Regulations, in accordance
with the compliance schedule in its
NPDES permit or by July 1.1983, where
no permit deadline exists. All industrial
users who wish to receive conditional
removal credits must supply the POTW
with the baseline monitoring report
information required by § 403.12(b) (1)-
(7) (except for new or modified
Industrial users who must only submit
the information required by § 403.12(b)
(l)-(6)). Finally, the POTW must make a
demonstration of its consistent
removals, in accordance with the
requirements specified in § 403.7(b) of
the regulatipn. submit a complete
application and comply with all the
other conditions for receiving removal
credit authority as specified in the
regulation.
Conditional removal credits are
available in only a limited number of
cases. Only a POTW that submitted a
complete program application in
accordance with the compliance
schedule in its permit, or by July 1,1983,
where no schedule deadline existed, and
the Approval Authority has not yet
formally acted upon that application.
would the POTW be eligible for
conditional removal credits authority. If
a POTW failed to submit its program in
such a timely manner, iris not eligible
for conditional credit authority. In
addition, a POTW is ineligible for
conditional removal credit authority if it
ta on a new compliance schedule by
virtue of an administrative order or
some other enforcement mechanism.
and a date beyond July 1.1983. has been
established as the deadline for
submission of a complete, approvable
program. For a POTW that did submit
its application on time and had been
granted conditional credit authority, but
upon review its program submission is
determined non-approvable, such a
POTW's conditional credit authority
will be withdrawn.
Section 403.7(b)—Demonstrated
Consistent Removal
The primary criticism of the removal
credits provisions in the past was that
the requirements for demonstrating a
POTW's consistent removals were
unworkable. National removal credits
were proposed by EPA as one way to
address this concern. Although national
credits cannot be promulgated for the
reasons discussed above, the Agency
anticipates that the demonstration
procedures finalized today will
adequately address some of the
concerns that would have been
addressed by the national removal
rates.
Generally, a POTW will collect 12
influent and effluent samples at
approximately equal intervals
throughout one full year, analyze these
samples for the appropriate pollutants
and calculate its consistent removal. In
lieu of or as a supplement to this
sampling, a POTW may use a historical
data base or an alternative sampling
design to demonstrate its consistent
removals. EPA recognizes, however, that
there might be problems with this
approach in some cases. Under some
circumstances, a pollutant known to be
contributed to a POTWa system may
not be detectable in either the influent
or effluent sample, or both. There are
several possible explanations for this
result. In some cases, a pollutant will be
undetectable in the influent because the
industrial discharges to a POTW will be
diluted by all the other wastewaters
contributed to the POTW's system. In
other cases a pollutant will be degraded
or will volatilize in the sewer system. In
still other instances, installation of
pretreatment technology by industries
discharging to a POTW may have
reduced pollutant loadings to such low
levels that pollutants cannot be
detected.
If a pollutant is measurable in some
influent and effluent samples, or is
measurable in some influent samples
but not measurable in any effluent
samples, 5 403.7(b](4) specifies that all
of the samples are to be used to
demonstrate a POTW's consistent
removal. Influent and effluent
observations below the level of
detectability are to be set at a value
equal to the detectability limit.
If a POTW cannot measure a
pollutant in some of its influent and/or
effluent samples and it chooses not to
utilize any sampling data, or if it is
unable to measure a pollutant in any of
its influent samples. I 403.7(b)(4]
specifies that a POTW may make some
other alternative showing to
demonstrate its removal capability. For
example, a POTW may rely on
treatability studies from POTW's with
similar characteristics (e.g., comparable
categorical industrial dischargers;
comparable industrial/non-domestic
and domestic wastewater flows;
comparable POTW treatment systems).
The Approval Authority must approve
of the POTW's alternative
demonstration.
In addition to these provisions, two
other features finalized today make a
demonstration of actual consistent
removal easier and more flexible. First,
instead of taking the average of the
lowest 50 percent of measured removals
as was required under the 1981 amended
regulations, consistent removal is
calculated in the final rule as the
difference between the average influent
and effluent concentrations in all of the
sample data. This method, which does
not exclude sample observations,
provides a more accurate and equitable
estimate of the actual removal generally
achieved than the method employed in
the 1981 regulation. Second, rather-than
prescribe rigorously the manner in
which the samples are to be collected,
the final rule describes these sampling
procedures in an appendix as guidance.
Although the options discussed above
may reduce the problem of non-
detectability in a number of cases, EPA
recognizes that there may be occasional
instances in which a POTW will be
unable to satisfy any of the
demonstration requirements. This
potentially could create an inequity
between certain POTWs. A POTW with
a high concentration of pollutants in its
influent can measure and thus
demonstrate removals. A POTW with a
low concentration of pollutants in its
influent may be unable to detect
incoming pollutants, even though some
are known to be discharged to its
system. Unless such a POTW can make
an alternative demonstration, as
provided for in the removal credits
regulation, it will be ineligible for
removal credit authority. EPA
acknowledges that if national removal
rates were made available, some
POTW's with low levels of pollutants in
their influent would be eligible for
removal credit authority. However, in
view of Congress' intention that a
POTW's removal rates be case-specific
based on demonstrated actual removals,
as discussed in detail above, EPA
believes that prohibiting a grant of
removal credit authority is justified
when a POTW is unable through any
means to show any removal of a
regulated pollutant.
Section 403.7(c)—Provisional Removal
Credits
Ordinarily, removal credits will be
sought for pollutants which are being
discharged currently in measurable
concentrations into a POTW.
Occasionally, however, a new or
modified industrial facility will want a
removal credit for a pollutant which is
A-4
-------
3121*
Federal Register / Vol. 49. No. 151 / Friday. August 3, 1984 / Rules and Regulations
not being discharged at measurable
concentrations into the POTW from any
facility. The POTW ia obviously
incapable of demonstrating actual
removal prior to the discharge of the
pollutant into the POTW treatment
system. Therefore, the final rule
provides at paragraph (c) that consistent
removal may be provisionally
demonstrated, using data from
treatability studies, provided that actual
consistent removal is demonstrated in
the conventional manner within 18
months of the commencement of the
discharge.
Procedures for modifying or
withdrawing provisional removal credits
were not included in the proposed
removal credits provision. Today's final
rule includes such procedures. The
process is the same as for withdrawal of
conditional removal credits.
Section 403.7feJ—POTW Application for
Authorization To Give Removal Credits
and ApprovoJ Authority Review
The provisions governing removal
credits applications are the same as
proposed on September 28,1982, and are
considerably more streamlined than
their counterparts in the 1981
amendments. Basically all that has to be
submitted in a list of the pollutants for
which removal credits are sought; data
demonstrating actual consistent
removal; the proposed new limits; a
certification that the POTW has an
approved local pretreatment program or
qualifies for the exception to this
requirement; a description of the
POTW's current method of managing its
sludge: and a certification that granting
removal credits will not cause the
POTW to violate applicable sludge
requirements and NPDES permit limits
and conditions. In contrast with the 1981
amendments, which restricted the
submission of applications to certain
times, the revised section provides that
qualified POTWs can submit
applications at any time. The Approval
Authority is required to review the
POTW's application in accordance with
the procedures in j 403.11, which
provide for completion of review-within
90 days from public notice of the
application unless a public hearing is
held or the public comment period
extended, in which case the Approval
Authority may have up to another 90
days.
Section 403.7(f)—Continuation or
Withdrawal/Modification of
Authorization To Grant Removal
Credits
The final rule, like the September 28,
1982, proposal states that once a POTW
has received authorization, to give
removal credits for a pollutant regulated
in a categorical pretreatment standard.
the POTW may automatically extend
that removal credit to the same pollutant
when regulated in other categorical
standards unless granting the removal
credit will cause the POTW to violate
any applicable sludge requirements or
permit conditions. This provision makes
explicit what was never expressly
stated in the January 1981 amendments;
that is, once removal credit
authorization is received for a particular
pollutant, the POTW may, without
reapplication. give the same credit for
that pollutant when regulated in other
categorical standards. The POTW may,
of course, elect not to extend the
removal credit for a particular pollutant
to other categorical standards or
particular facilities in an industry
category.
Upon being granted removal credit
authority, the removal credits will be
included in the POTW's NPDES permit
Because the procedures to initially
authorize a POTW to grant removal
credits are essentially the same as those
to modify or revoke and reissue a
POTW's permit to incorporate the
removal credits (i.e., notice, comment
and opportunity for a public hearing),
the Approval.Authority should consider
commencement of the process to amend
the POTW's permit simultaneously with
the formal review of a complete
application for removal credit authority.
This would reduce the administrative
burden of acting separately on the
removal credits application and permit
change.
As a condition of continued
authorization to give removal credits,
the POTW must continue to comply with
all the requirements of paragraph
(a)(3)(iii)-{v). Compliance with these
requirements may be examined by the
Approval Authority at any time, but at
the very least, must be ascertained upon
reissuance of the NPDES permit. The
penalty for failure to comply with the
paragraph (a){3) requirements is
withdrawal or modification of the
removal credits. The regulation specifies
the procedures to be followed when
initiating an action to modify or
withdraw.
Today's final removal credits
regulation does differ considerably In
one aspect from that which was
proposed. Prior removal credits rules
were criticized as unworkable in part
because of the potential uncertainty
they created. POTWs were required to
submit periodic compliance reports that
included sampling data to indicate
whether or not they were maintaining
their approved consistent removal rates.
Failure to maintain that removal rate
could potentially result in an .immediate
adjustment of its approved removal
rates to reflect the change. In turn, the
industrial users applicable categorical
pretreatment standards reflecting-the
removal credit would also have to be
readjusted to reflect the POTW's new
removal rates.
The final rule promulgated-today
diminishes the uncertainty of changing
removal credits and shifting industrial
discharge limits. Once a POTW satisfies
the demonstration requirements and
does not violate the criteria specified in
paragraph (aj(iii)-{v), the removal
credits will generally remain set for the
term the POTW's NPDES permit. The
removal credits could be modified or
withdrawn during the permit term'-only
in the case of consistently and
substantially poor POTW performance.
As a means of monitoring for
occurrences of those circumstances in
which a readjustment would be
necessary, POTWs are required to
submit compliance reports at least
annually to the Approval Authority for
its review that include sampling data to
indicate their removal capability. A
minimum of one sample per month
during the reporting period is required
and all the sampling data must be
included in the report. As the POTW's
removal performance will be
reevaluated when its permit expires,
sampling data included in these
compliance reports also can be used to
justify continuation of the removal
credits or to calculate its new removal
capability at the end of the permit term.
A removal credit determination is
based on the removal efficiency (i.e.,
percent removal) of a pollutant at the
POTW. Variability in removal efficiency
is inherent in any treatment system,
even those that are specifically designed
to remove particular pollutants. POTWs,
however, are generally designed to
remove suspended solids and
biodegradable organic materials, not
heavy metals, cyanide or non-
biodegradable toxic organics. The
removals of toxic pollutants are for the
most part incidental to the secondary
treatment employed by POTWs.
In addition to the design of the POTW,
there are a number of other factors that
contribute towards the variability in
removal efficiency. These include the
state of the pollutant (whether soluble or
insoluble); pollutant concentrations in
the influent: dilution of the raw
wastewaten or the detection limit of a
particular pollutant. Because of the
combined effect of these factors and
site-specific conditions at a POTW, it is
impossible to determine the expected
A-5
-------
Federal Register / Vol. 49. No. 151 / Friday. August 3. 1984 / Rules and Regulations 31217
varibility on a pollutant-by-pollutant
basis across all POTWs.
Tha Agency recognizes that some
variability-will exist and that nothing
can be done to totally eliminate it.
Recognizing this variability factor, the
Agency strongly believes that a fair
balanct must be struck between
ensuring continued consistent removal
of a pollutant which formed the basis for
the removal credit and the need of
POTWs and their industrial users to
have a degree of certainty in the
removal credit and the adjusted
categorical pretreatment standards
reflecting the credit. To obtain this
balance, the Agency has established a
criterion for making a finding that a
POTW is no longer achieving proper
removals of a given pollutant
Before the Approval Authority begins
a proceeding to modify or withdraw the
removal credits prior to permit
expiration, it must make a finding that
"the POTWs consistent removal rate is
consistently and substantially lower
than the removal credit specified in the
POTWs NPDES permit." This criterion
(a established so that a POTW does not
lose its removal credit authority during
the permit term because of minor
problems at the POTW or situations
outside of the POTWs control that
temporarily reduce its originally
demonstrated removal efficiency.
However, if it is determined that the
POTWs consistent removal rate is
consistently and substantially lower
than the removal credit, this indicates
serious problems at the POTW and
justifies invocation of the modification
or withdrawal provisions of the
regulation. This regulatory approach.
assuming that initially established
removal credits will be effective for the
life of the POTW's NPDES permit absent
substantially worsened POTW
performance or a violation of the
conditions specified in paragraph (a)(3)
of the rule, should provide the desired
balance of consistent removals and
POTW/industry certainty.
The "consistently and substantially
lower" criterion was purposefully-
adopted to allow all the relevant facts of
any particular situation to be considered
in deciding whether removal credits
should be modified. A more specific
criterion (e.g., designating a particular
percent reduction in a POTWs removal
rates as substantial) would be
technically inappropriate, since the
degree of unavoidable variability in a
POTWs removal rate is likely to vary
from plant to plant. It is thus more
appropriate that the Approval Authority
make a decision, on a case-specific
basis, whether a POTW's removals have
substantially worsened on a consistent
basis. If the Approval Authority initiates
the procedures to modify or withdraw
the credit based upon such a decision.
the affected POTW and its Industrial
users would have an opportunity at that
time to challenge the decision and
demonstrate that the POTW's removals
have not consistently and substantially
worsened.
While the averaging of 12 monthly
samples will tend to stabilize the
POTWs removal rate, it should be
noted that some variations in the yearly
rates must be expected. Key to the
impact of this yearly variation on both
POTW's and industry is the magnitude
of the credit a POTW is considering to
grant. The following table shows the
effluent limits that an electroplater
would have to meet depending on the
removal credit granted to the POTW.
R«nov* cr«cK (p«rc»nD
0
20......_.
Cadmium
(mg/l)
1.2
1.5
1.71
2.0
2.4
3.0
4.0
8.0
12.0
Zine(mg/
4.2
5.25
6.0
7.0
8.4
10.5
t4.fl-
21.0
42.0
The granting of a removal credit
anywhere hi the range of 40 and 60
percent results in a range of industrial
effluent limits which can probably be
met by the same industrial treatment
technology—2.0 to 3.0 mg/l for cadmium
and 7.0 to 10.5 mg/l for zinc. The impact
of a reduced removal credit on an
industrial user would be small since the
same technology would have been
employed. However, this is not the case
for those POTWs that intend to grant
credits in the 80-to-90 percent range.
Removal credits from 80 to 90 percent
would allow industrial users to install
little or no technology to meet the limits.
The failure of the POTW to demonstrate
these high removals will have major
impacts on the industrial users which
may be required to install additional
technology if the removal credit is
reduced. POTW operators should be
aware that the demonstration of high
removals (75-90 percent) is difficult and
should be thoroughly evaluated to
provide their industrial users long-term
and stable effluent limits.
Another difference between today's
final rule and the September 28,1982,
proposal are the procedures for
modifying or withdrawing removal
credits when circumstances arise that
warrant a change. As proposed, if a
POTW failed to maintain its consistent
removal rate or violated some other
eligibility criteria (e.g., violated sludge
requirements or its permit limits), the
POTW had to notify the Approval
Authority, return to compliance within
six months and satisfy the Approval
Authority that the problem would not be
likely to recur. If, at the end of this six-
month period, the POTW did not return
to compliance or satisfy the Approval
Authority that the problem is non-
recurring in nature, the Approval
Authority would have had to revoke or
modify the removal credits. The
Approval Authority could, however,
have extended the time for compliance
for up to one year if the POTW
demonstrated good faith efforts to return
to compliance. Where the removal rates
were modified or withdrawn, industries
would have had to comply with the
modified discharge limits or original
categorical standard, whichever was the
case, within 18 months.
After reevaluating this proposed
change, taking into account public
comments received, EPA has decided
not to finalize the procedures as
proposed. Instead, the modification/
withdrawal procedures in today's final
rule are more similar to those specified
in the 1981 removal credits provision.
The significant difference is that the
procedures promulgated today provide
for notice and comment before the
removal credits are modified or a
POTW's authority to grant removal
credits is withdrawn. The Agency
believes the process adopted by the
final rule better serves the requirements
of adequate due process.
Under the final rule, the Approval
Authority is required to make a
preliminary determination that a POTW
is in violation of any of the eligibility
criteria specified in paragraph (a)(3)(iii)-
(v), or that its ongoing removals are'
substantially and consistently lower
than the removal credits. The Approval
Authority shall then, in accordance with
the procedures found in § 403.11(b) (1)
and (2) of the General Pretreatment
Regulations, issue a public notice of its
intent to modify or withdraw, and
provide for public comment and an
opportunity for a public hearing on the
matter. It is during this time that a
POTW, its industrial users or any
interested party can present a case
against modification or withdrawal. At
the close of the public comment period
and after a public hearing (if one is
held), the Approval Authority will make
its final decision based on all available
information, including that received in
comments and at the hearing. If the
removal credits are to be modified or
removal credit authority withdrawn, the
POTW arid its industrial users must be
A-6
-------
Federal RegJatat / Vol. 49, No. 151 / Friday, August 3, 1984 / Rules and Regulation
notified and apprised in writing of the
reasons for the modification or
withdrawal Where the removal credits
are modified, the affected industrial.
users will be required to comply witk
the readjusted discharge limits, or. in the
case of withdrawal of removal credit
authority, with the original limit*
prescribed by the applicable categorical
pretreatment standards. Compliance
with these limita must be achieved
within a reasonable time following
modification or withdrawal The amount
of time allowed for compliance from the
date that the removal credit ia modified
or withdrawn must be no greater than
the amount of time allowed for
compliance in the applicable categorical
standard. For example, if a pretreatment
standard provided for a compliance
period of theea year* from me date of
promulgation, an industrial user affected
by the modification or withdrawal of a
removal credit could be granted a
maximum compliance period of three
years from the date of modification or
withdrawal. Of course, the Approval
Authority could establish a shorter
period for compliance after considering
the necessary adjustment to existing
treatment technology or the amount o£
additional treatment that must be
installed,
IV. Summary of Public PsDGtidpotioa
Numerous governmental agencies,
individuals, industries, and trade
associations provided comments on the
proposed removal credit role published
in the Federal Register on September 28,
1982. The following parties provided
comments: Detroit Water and Sewerage
District; Caterpillar Tractor Company;
Ahr Products and Chemicals, Inc.; South
Carolina Department of Health and
Environmental Control: Howard M.
Cohere Village of Sanget, IL; League of
Women Voters of Maryland, Inc.; Barge,
Waggoner/Summer and Cannon;
Midland-Rose Corp.; Great Lakes
Tomorrow, M/M Gordon V. Bond:
General Motors Corp.; American Iron
and Steel Institute Natural Resources
Defense Council; National Association
of Metal Finisher* American Paper
Institute/National Forest Product*
Association; Steven H. Bigelow; Conoco,
Inc.; The Standard O9 Company (Ohio);
Bausch and Lomlr, Anne W. Amacher,
Ph.D.; Chemical Manufacturers
Association; Texaco, Inc.; League of
Women Voters of South Carolina; The
League of Women Voters of Kentucky;
Monsanto Company; Babcock and
Wilcox; Metropolitan Denver Sewage
Disposal District No, U Standard Oil
Company (Indiana); League of Women
Voters of Marian County, GA; County
Sanitation District* of Los Angeles
County; League of Women Voters of
Findlay, OH; and the Chicago
Association of Commerce and Industry.
Comment- The majority of comments
received addressed various aspects of
the national removal credits concept
including the legalityof national
removal credits, tha method of
calculating the national removal rates,
national credits for non-toxic pollutants
and the procedures a PCTW must
follow to obtain and maintain removal
credit authority when utilizing national
credits.
Response: The comments regarding
the legal basis of national removal
credits have been addressed in the
comprehensive discussion regarding this
issue in ore preamble. Since national
credits have not been retained in the-
rmal rule, comments regarding certain
technical aspects (e.g., selection of 25th
percentila, the broad definition of
POTW "compliance" with secondary-
treatment, the impact of negative
removal rates in rjalmlaHng the national
removal rates) have become irrelevant
Similarly, those comments addressing,
the procedures and precondition* for
utilizing national credits have also
become irrelevant
Comment: One commenter suggested
that the removal credit regulation
provide POTWs the option of
substituting their local standard*
applicable to indirect dischargees for the
national categorical pretreatment
standard* when these local standards-
are based on. local receiving water
quality or sludge disposal criteria.
Response: The removal credit concept
established in section 307(b) of the
Clean Water Act, provides for a credit
against a national categorical
pretreatment standard equal to or less
than the demonstrated removal by a
POTW for a specific pollutant. If a
POTW can demonstrate that its actual
removal rate would allow an adjustment
to the categorical pretreatment standard
that results in a standard less stringent
than the POTW's current local standard
for a particular pollutant then die
POTW may impose its local standard. If,
however, the adjusted categorical
standard remain* more stringent than
the local standard, then the adjusted
categorical pretreatment standard must
be applied.
Comment: One commenter objected to
the procedure whereby a POTW self-
certifies that it complies with applicable
sludge requirements, limits and
conditions in the POTW's NPDES
permit and that it has an approved
pretreatment program. The objection
concerned the amount of discretion
given the POTW to determine
independently the complex factual
matters on which initial and continuing
qualification for removal credit depends.
Response: The final regulation
provides that a POTW must certify that
it has an approved pretreatment -
program and that by granting removal
credits it will not violate any permit
limits or conditions, pr applicable
Federal. State and local sludge
requirements. The Agency retains the
authority to review the certifications
and independently verify their accuracy.
Information regarding the status of the
local pretreatment program and
compliance with NPDES permits is
readily available. M many instances, the
Agency staff making me initial review of
the removal credit authority application
are also responsible for tracking me
POTW's performance in the other two
areas. Similarly, compliance with sludge
requirements can be easily corroborated
either by communicating within the
Agency or by contacting the appropriate
State or local agency. Additionally, the
applicant most describe its sludge
management plan. In those instances
where the information is not sufficient to
determine whether the POTW will
continue to be in compliance with
sludge requirements, the Agency may
request more information.
Comment: Many comments
questioned the Agency's basis for
imposing additional conditions for
obtaining removal credit authority that
are not specifically provided in section
307(b) of the CWA. Specifically, the
comments concerned the requirement-
that: (a) A POTW have an approved
pretreatment program; (b) comply with
all applicable Federal, State and local
sludge management and disposal
requirements; and (c) be in compliance
with its NPDES permit discharge limits
for the toxic pollutants) for which
removal credits are sought. The
comments suggested mat the Agency
could only impose those criteria
explicitly mentioned in section 307(b)
(i.e., that a POTW remove all or any part
of the toxic pollutant, that the discharge
from the POTW does not violate the
effluent limitation or standard which
would be applicable if the pollutant
were discharged by the source other
than through the POTW and that the
POTW's sludge use or management be
in compliance with the requirements
established under section 405 of the
Clean Water Act).
Response: The Agency believes that
the imposition of these preconditions to
removal credit authority is not only a
logical exercise of its discretion, but is
directed by the statute and
congressional intent. This response will
A-7
-------
•petJeral Register / Vol. 49. No. 151 / Friday. August 3. 1984 / Rules and Regulations 31219
address each of Ore three conditions
separately since each condition is based
on different premises.
The "compliance with toxic limits"
requirement in section 403.7{a](3)(v) of
the removal credit rule was first
Imposed as a regulatory requirement as
proposed in September 1982. This
provision has been changed in the final
rule, for the reasons previously
discussed, to require the POTW to
maintain compliance with all limits and
conditions in its NPDES permit after
granting removal credits. This
requirement is consistent with the broad
purposes of section 307(b) that
discharges from industrial users of
POTWs not interfere with a POTWs
ability to comply with its NPDES permit
The second requirement is that a
POTW have an approved pretreataent
program. The Agency believes that the
imposition of this requirement is a
proper exercise of the Agency's
authority to ensure that a POTW
minimizes the potential of pass through
of pollutants-or interference with the
POTW and was contemplated by
Congress when it amended the Federal
Water Pollution Control Act in 1977 (the
Clean Water Act). The statutory
language and the legislative history.
when read together, provide the
requisite authority to require a
prelreahnent program as a precondition
to a POTWs authority to grant removal
credits.
The 1977 amendments added two new
provisions relating to pretreatment. One
provision, section 402(b)(8), imposes on
POTWs that receive discharges from
industries subject to categorical
pretreatment standards a requirement to
develop a local pretreatment program.
The second provision, in section
307(b)(l). allows POTWs to adjust
categorical standards to reflect the
POTW's ability to remove any or all of
the regulated pollutant These two
provisions are given meaning when read
in light of the legislative history which
clearly shows that Congress intended
that removal-credits be integrally tied to
an approval pretreatment program.
The Senate, when debating the
conference report, addressed this
connection between removal credits
(discussed as "local credits") and local
pretreatment programs:
Whet* * local compliance program i»
approved. EPA and the permitting States may
approve ca*e*by-caM modifications of the
national pcetreatment standards—or local
credits—for documented pollutant removals
attained by a publicly owned treatment
work*. To receive a local credit there must be
a demonstration that the pollutant is
degraded or treated: credit! will not be given
for dilution* * *. Tying locahaedita to local
compliance programi not only provides an
incentive for local participation, but more
importantly, it provides assurance that the
removal levels which justified the local
credit* will be maintained by a publicly
owned treatment works committed to
operating a sound pretreatment program.
(Legis. Hist., Vol. 3. p. 461-482).
The House similarly discussed the
relationship between the two provisions
in its debate of the conference report:
Under the amendment to section 3O7(b) the
Administrator would establish national
pretreatment itandards for toxic pollutants
based on the best available technology
economically achievable, or any more
stringent effluent standards under section
307(A). Then in applying these pretreatment
standards through its pretreatment programs,
the owner or operator of a municipal
treatment works could modify the
requirements applicable to individual classes
of sources introducing that pollutant into the
treatment works to reflect the degree of
reduction of that pollutant achieved by the
treatment works (emphasis added). (Legis,
Hist., Vol. 3, p. 342-343.)
It is apparent that the Agency has
effectuated Congressional intent by
imposing this precondition for removal
credit authority. Moreover, the Agency
believes that it has adequate authority
to impose such a requirement to
accomplish the goal of avoiding the
potential for pass through or
interference under its broad rulemaking
authority to section 501 of the CWA.
The Agency's position was judicially
sanctioned in a recent decision by the
U.S. Court of Appeals for the Third
Circuit in National Association of Metal
Finishers (NAMF) et al. v. EPA. 719 F.
2d 824 (3d Cir. 1983). Petitioners in that
case specifically challenged the local
pretreatment program requirement
claiming that the Agency acted without
authority in imposing this precondition
to granting nemoval credits. The court
disagreed with petitioners and adopted
the reasoning *ert out above as the basis
of the agency's authority.
The third requirement that the POTW
maintain compliance with all applicable
Federal. State, and local sludge disposal
requirements after granting removal
credits, was also challenged by
commenters as being contrary to the
statute. The Agency maintains the
position it presented in the regulations
promulgated on January 28,1981. which
included the current provision regarding
compliance with sludge disposal
requirements. Essentially, the Agency
continues to believe that it is acting
within its authority granted by sections
307(b) and 405 of the CWA in
conditioning removal credit allowances
on continued compliance with
applicable requirements established
under the Solid Waste Disposal Act
(including Title n of this Act more
commonly referred to as the Resource
Conservation and Recovery Act
(RCRA)). the Clean Air Act the Toxic
Substances Control Act (TSCA), the
Marine Protection. Research and
Sanctuaries Act (MPRSA), and State
regulations developed under Subtitle D
of RCRA. (For a more detailed
discussion of this issue, see 48 Fed. Reg.
at 9428.) In addition, it should be noted
that these sludge requirements were
contained in the 1981 General
Pretreatment Regulations upheld by the
Third Circuit in NAMF et al. v. EPA,
supra.
Comment: Several comments were
received which supported the exclusion
of the combined sewer overflow (CSO)
compensation factor when calculating
the revised categorical standard.
Several comments were received which
argued that the CSO factor should have
been retained.
Response: EPA has analyzed the
relationship of CSOs and removal
credits in two different ways. The first
approach examined the amount of time
CSO events occur. In 1978.15 POTWs
were surveyed to determine the
frequency of rainfall-triggered
overflows. The Agency determined that
the average POTW will incur combined
sewer overflow only 7.3 percent of the
time. Even assuming that no treatment
occurs during an overflow situation, the
measurable effect on the revised
categorical standard is not significant
Therefore, compensation for CSOs on
the basis of time is not necessary. (For a
detailed example of the effect CSO» can
have on the revised standard based on
the time CSO events occur, see the
proposed removal credits rule in the
September 28,1982 Federal Register (47
FR at 42701)).
The second approach examined the
amount of pollutants that escaped
treatment during CSO events. This
involved the toxic pollutants discharged
by industry-which are not treated at the
POTW during CSO events and which
settle in the sewer system during normal
dry conditions, and are resuspended
during CSO events. Recent EPA data
indicate that approximately 30 percent
of the toxic metals in a combined sewer
flow (i.e.. during wet weather conditions
sufficient to produce an overflow event)
are due to the problem of resuspension.
The concern relative to removal credits
is that toxics reauspended under wet
weather conditions are carried out the
overflow point. As a result, a portion of
the toxic pollutants contributed by
industrial users never reach the POTW
and is therefore not removed.
A-8
-------
31220
Federal Register / Vol. 49, No. 151 / Friday, August 3, 1984 / Rules and Regulations
EPA analyzed the data collected on
heavy metals to determine the amount
of pollutants resuspended. The amount
of resuspension was then included in a
mass balance to determine the amount
of untreated heavy metals discharged
during a CSO event This analysis
indicated that on average, eight percent
of the metals bypassed the POTW and
were thus not treated. After applying
this eight percent bypass factor to
several sample removal rates, the
Agency concluded that its effect on the
adjusted industrial discharge limit
would be minimal. Thus, neither the
frequency of CSO events nor-the amount
of toxics discharged during such events
warrant a regulatory provision requiring
CSOs to be factored into the formula for
determining a removal credit
Comment: Two comments suggested
that POTWs must have an affirmative
obligation to seek removal credit
authority. Giving POTWs the discretion
to seek or not seek removal credits
could frustrate the intent of the
provision and may result in unnecessary
treatment
Response: The statute provides that a
POTW "may" seek removal credit
authority. EPA is not empowered to
require a POTW to seek removal credit
authority.
Comment: Several commenters raised
the issue of a POTWs "compliance"
with a stated removal rate and the
grounds for withdrawal or modification
of removal credits. This comment
involves two concerns. The first is the
POTWs concern for some degree of
latitude before a POTW is considered to
be out of compliance with its
demonstrated removal rate. The second
is the concern of industrial users who,
having obtained removal credits and
designed treatment facilities to meet a
stated standard, desire to have some
reasonable period without any change
to their discharge standards, industrial
users are essentially seeking some
degree of certainty in their limits for
planning purposes.
Response: As discussed above in
detail, the Agency strongly believes that
a fair balance must be struck between
ensuring continued consistent removal
of a pollutant which formed the basis for
the removal credit and the need of
industrial users to have, some guarantee
of certainty, for a reasonable period of
time, as to their discharge, limits. To
obtain this balance, the Agency has
developed a criterion to determine when
the POTW is no longer achieving
consistent removal for a given pollutant
Comment: Many commenters
questioned the Agency's procedure for
handling influent and effluent samples
when the pollutant is not detectable.
Most commenters suggested that for
effluent samples the appropriate
procedure is to assign the samples a
concentration value of zero and not to
assume that the concentration is at the
level of detectability for that pollutant.
Otherwise, they argued, the procedure
may fail to reflect the full extent of the
actual removal efficiency.
Response: The Agency believes that,
in general, the use of the detection limit
as an estimate of immeasurable
concentrations in an effluent, where the
influent was detectable, will provide a
better approximation of actual removals
than will the use of a zero value. Using
zero as a measure of the effluent
concentration necessarily results in a
conclusion that the pollutant is
experiencing a 100% removal by the
POTW. Such a result is theoretically
unlikely and inconsistent with the
Agency's POTW removal data collected
from 50 well-operated secondary
treatment plants. The use of the
detection limit is likely to produce a
somewhat conservative estimate of
removals. However, in most cases, the
calculated removal should not be much
lower than the actual removal and
generally should be more accurate (and
more environmentally protective) than
that calculated by assuming a zero
discharge effluent. In any event in cases
of non-detectability, the POTW has the
option of making an alternative
demonstration to qualify for removal
credit authority.
Comment: One commenter questioned
the proposed procedure for addressing
violations by the POTW of its removal
rate and the sanctions available. The
commenter argued that the procedure
may allow the violation to persist too
long and represent an unnecessary
sndangerment to the environment
because of interference, pass through
and sludge contamination.
Response: The Agency agrees that the
proposed procedure which could allow
up to 12 months before withdrawal or
modification procedures are instituted
provided too much latitude to a POTW
which is experiencing problems.
Consequently, the Agency is amending
this provision. As discussed above,
today's final rule recognizes that some
variability in a POTWs removal rates
can be expected. However, if a POTW's-
removal capability does consistently
and substantially worsen, indicating
that a serious problem exists and
requiring long-term corrective measures
be taken, or it violates any other
precondition of its removal credit
authority, the Approval Authority will
initiate the process to withdraw a
POTW's authority to grant removal
credits or to modify those credits. Public
notice of this action will be given, and a
comment period and opportunity for a
hearing provided for. The Agency
believes that once grounds for '
modification or withdrawal do arise, the
procedures in the final rule allow for
prompt action by the Approval
Authority. In addition, these procedures
more adequately satisfy due process
requirements than past procedures.
Comment: Some commenters objected
to the 18 month time limit for industrial
users to comply with the pretreatment
standard once a removal credit has been
modified or withdrawn. They argued
that the time limit should be three years.
Response: The Agency partially
agrees with this argument. The Agency
has revised this part of the regulation to
provide that the time period for
compliance be no longer than the time
allowed in the pretreatment standard or
such shorter time as determined after
considering the amount of additional
treatment that must be installed. This
time period is the same as was allowed
under the 1981 revised removal credit
regulation.
Comment: Some commenters
questioned the adequacy of the
compliance reporting requirements.
They believed that one annual report
will not be sufficient to detect quickly
any drops in removal efficiencies.
Response: The Agency disagrees with
this contention. A POTW's initially
demonstrated removal rates were based
on 12 representative samples taken over
the course of one full year. Requiring
one compliance report per year that
includes a similar sampling requirement
(i.e., 12 representative samples taken at
equal intervals over that year) provides
an accurate means of comparing a
POTW's ongoing performance with its
originally approved demonstrated
removal efficiency. These reports will be
reviewed by the Approval Authority.
Furthermore, while the new regulations
will minimally only require one annual
report, there are several other sources of
information which can augment the
removal rate compliance reporting. In
addition to this report, a POTW will be
providing other reports as part of their
NPDES permit and pretreatment
program. POTWs will also be subject to
pretreatment program audits and
inspections which can be used to
investigate a POTW's compliance with
its removal rates.
Comment: Many commenters
questioned the provision in the proposed
rule which provides that the removal
rates demonstrated by the POTW that
formed the basis for removal credits
become enforceable conditions of the
POTWs NPDES permit. The commenters
A-9
-------
Federal Register / Vol. 49. No. 151 / Friday. August 3. 1984 / Rules and Regulations 31221
suggested that the provision would
discourage POTW's from applying for
removal credit authority.
Response: Incorporating the removal
credits as an enforceable condition into
the POTW*« NPDES permit was clearly
intended by Congress when section
307(b) wai passed. The House debate on
the conference report contained the
following statement: "Any effluent
reduction attained by the treatment
works and used to justify a modification
of pretreatment requirements must be a
permit condition enforceable against the
owner or operator of the treatment
works" (Legis. Hist., Vol. 3. p. 343).
Thus, itjs clear that this requirement
was contemplated by the Congress. The
argument that this will act as an
impediment to POTWs seeking removal
credit authority does not militate against
the requirement It only assures that the
POTW will strive to maintain its
consistent removal rates. It should also
prove to be an incentive for industrial
users enjoying the benefit of removal
credits to taJce greater interest in the
POTW's operation and pretreatment
program.
Comment: One comment raised the
issue of whether the proposed method
for calculating the removal rate is
appropriate. The commenter argued that
the technique of averaging all the
influent and effluent samples will mask
variability and may result in a distortion
of the removal efficiency.
Response: As the Agency stated in the
proposed rule, the technique of
averaging the influent and effluent data
will provide a more reliable estimate of
the actual removal generally achieved
than the method used in the 1981
regulations. No sample observations will
be excluded from the calculation.
Miscellaneous
In the September 28,1982 proposal,
several sections of the General
Pretreatment Regulations were proposed
to be amended because they referenced
the removal credits provision. Today's
action finalizes those changes to
conform to the new removal credits
section.
In addition to these changes.
I 403.8(e) also is being revised. Section
403.8(e) specifies specific circumstances
for modifying or revoking and reissuing
a POTW's permit. These grounds
include, among olhers. incorporation of
a compliance schedule for development
of a POTW's pretreatment program,
section 301(h) and section 301(i) permit
conditions and an approved POTW
pretrsatment program. By today's
action. § 403.8(e) is revised to specify
that incorporation of the removal credits
gawrteel by a POTW is cause for
modifying or revoking and reissuing a
POTWs permit. Amending § 403.8(e) in
this way ij consistent with Congress1
intent, as discussed above, that the
removal credits be placed in the
POTW's permit and thus be an
enforceable permit condition. In
addition, past removal credit provisions
and the September 28.1982, removal
credit proposal required incorporation of
removal rates into the permit.
Executive Order 12291
Under Executive Order 12291, EPA
must judge whether a regulation is
"major" and therefore subject to the
requirement of a Regulatory Impact
Analysis. This regulation simplifies
existing requirements and will have the
ultimate effect of reducing pollution
control costs. It is not a major regulation
because it does not meet the criteria set
forth in the Executive Order.
Regulatory Flexibility Act
Under the Regulatory Flexibility Act, 5
U.S.C. 601 et seq., EPA is required to
prepare a Regulatory Flexibility
Analysis to assess the impact of rules on
small entities. No regulatory flexibility
analysis is required, however, where the
head of the agency certifies that the rule
will not have a significant-economic
impact on a substantial number of
entities. I hereby certify, pursuant to 5
U.-S.C. S£05(b), that today's final action
will not have a significant impact on a
substantial number of small entities.
List of Subjects in 40 CFR Part 403
Confidential business information;
Reporting and recordkeeping
requirements; Waste treatment and
disposal; Water pollution control.
Dated: July 27.1984.
WUHam D. Ruckelshaus,
Administrator.
PART 403—GENERAL
PRETHEATMENT REGULATIONS FOR
EXISTING AND NEW SOURCES OF
POLLUTION
For the reasons set out in the
preamble. 40 CFR Part 403 is amended
as follows:
1. The authority citation for 40 CFR
Part 403 is as follows:
Authority:.Sec. 54(c)(2) of the Clean Water
Act of 1977 (Pub. L. 95-217), sections
204(b](l)(C). 208(b)(2)(C)(iii), 301(b)(l,
301(b)(2)(A)(ii). 301(b)(2)(C), 301(h)(5).
30a(iKZ), 304(e), 304(g), 307, 308, 309. 4O2(b).
405, and 501(a) of the Federal Water Pollution
Control Act {Pub. L. 92-500). ai amended by
the Clean Water Act of 1977.
2. 40 CFR 403.7 is revised to read as
follows:
§ 403.7 Removal credit*.
(a) Introduction—(1) Definitions. For
the purpose of this section:
(i) "Removal" means a reduction in
the amount of a pollutant in the POTW's
effluent or alteration of the nature of a
pollutant during treatment at the POTW.
The reduction or alteration can be
obtained by physical, chemical or
biological means and may be the result
of specifically designed POTW
capabilities or may be incidental to the
operation of the treatment system.
Removal as used in this subpart shall
not mean dilution of a pollutant in the
POTW.
(ii) "Sludge Requirements" shall mean
the foll«wing statutory provisions and
regulations or permits issued thereunder
(or more stringent State or local
regulations): section 405 of the Clean
Water Act; the Solid Waste Disposal
Act (SWDA) {including Title II more
commonly referred to as the Resource
Conservation Recovery Act (RCRA) and
State regulations contained in any State
sludge management plan prepared
pursuant to Subtitle D of SWDA); the
Clean Air Act: the Toxic Substances
Control Act; and the Marine Protection,
Research and Sanctuaries Act.
(2) General. Any POTW receiving
wastes from an Industrial User to which
a categorical Pretreatment Standard(s)
applies may, at its discretion and
subject to the conditions of this section,
grant removal credits to reflect removal
by the POTW of pollutants specified in
the categorical Pretreatment
Standard(s). The POTW may grant a
removal credit equal to or, at its
discretion, less than its consistent
removal rate. Upon being granted a
removal credit, each affected Industrial
User shall calculate its revised
discharge limits in accordance with
subparagraph (4) of this paragraph.
Removal credits may only be given for
indicator or surrogate pollutants
regulated in a categorical Pretreatment
Standard if the categorical Pretreatment
Standard so specifies.
(3) Conditions for authorization to
give removal credits. A POTW is
authorized to give removal credits oniy
if the following conditions are met:
(il Application. The POTW applies
for, and receives, authorization from the
Approval Authority to give a removal
credit in accordance with the
requirements and procedures specified
in paragraph (e) of this section.
(U) Consistent removal determination.
The POTW demonstrates and continues
to achieve consistent removal of the
pollutant in accordance with paragraph
(b) of this section.
A-10
-------
31222 Federal Register / Vol. 49. No. 151 / Friday. August 3. 1984 / Rules and Regulations
(Hi) POTW local pretreatment
program. The POTW has an approved
pretreatment program in accordance
with and to the extent required by-Part
403; provided, however, a POTW which
does not have an approved pretreatment
program may, pending approval of such
a program, conditionally give credits as
provided in paragraph (d) of this section.
(iv) Sludge requirements. The granting
of removal credits will not cause the
POTW to violate the local. State and
Federal Sludge Requirements which
apply to the sludge management method
chosen by the POTW. Alternatively, the
POTW can demonstrate to the Approval
Authority that even though it is not
presently in compliance with applicable
Sludge Requirements, it will be in
compliance when the Industrial User(s)
to whom the removal credit would apply
is required to meet its categorical
Pretreatment Standard(s) as modified by
the removal credit. If granting removal
credits forces a POTW to incur greater
sludge management costs than would be
incurred in the absence of granting
removal credits, the additional sludge
management costs will not be eligible
for EPA grant assistance.
(v) NPDES permit limitations. The
granting of removal credits will not
cause a violation of the POTW's permit
limitations or conditions. Alternatively,
the POTW can demonstrate to the
Approval Authority that even though it
is not presently in compliance with
applicable limitations and conditions in
its NPDES permit, it will be in
compliance when the Industrial User(s)
to whom the removal credit would apply
is required to meet its categorical
Pretreatment Standard(s], as modified
by the removal credit provision..
(4) Calculation of revised discharge
limits. Revised discharge limits for a
specific pollutant shall be derived by
use of the following formula:
y=
l-r
where:
x=pollutant discharge limit specified in the
applicable categorical Pretreatment
Standard
r=removal credit for that pollutant as
established under paragraph (b) of this
section (percentage removal expressed
as a proportion, i.e., a number between 0
and 1)
y=revised discharge limit for the specified
pollutant (expressed in same units as x)
(b) Establishment of Removal Credit;
Demonstration of Consistent Removal.
A POTW may be authorized to grant a
removal credit that does not exceed its
consistent removal rate. In order to
demonstrate consistent removal, the
POTW shall, for each pollutant with
respect to which removal credit
authorization is sought, collect influent
and effluent data and calculate
consistent removal in accordance with
the following requirements. As a
condition of retaining removal credit
authorization, the POTW's consistent
removal must continue to be equal to or
greater than the removal credit.
(1) Number of samples. At least
twelve representative samples of
influent and effluent shall be taken at
approximately equal intervals
throughout one full year. Upon
concurrence of the Approval Authority,
a POTW may utilize an historical data
base either in lieu of or as a supplement
to these twelve samples. In order to be
approved, the historical data base must
be representative of the yearly and
seasonal conditions to which the POTW
is subject and be representative of the
POTW's performance for at least one
year. As an alternative to the above, a
POTW, upon concurrence of the
Approval Authority, may utilize an
alternative sampling design, as long as
the alternative design provides for
samples to be taken at times which are
representative of the POTW's normal
operating conditions and the different
seasonal conditions to which the POTW
is subject.
(2) Method of Sampling. The POTW
must use the composite sampling
method unless the grab sampling
method is more appropriate. A
description of these methods and
suggestions on when each method
should be used are included in
Appendix E as guidance.
(3) Method of Analysis for Pollutants.
The POTW shall analyze the samples
for pollutants in accordance with the
analytical techniques prescribed in 40
CFR Part 136. If 40 CFR Part 136 does
not contain analytical techniques for the
pollutant in question, or if the Approval
Authority determines that Part 136
analytical techniques are inappropriate,
the analysis shall be performed using
validated analytical methods or any
other applicable analytical procedures
approved by the Approval Authority,
including procedures suggested by the
POTW.
(4) Calculation of Consistent
Removal, (i) The consistent removal.
denoted by r, for a specific pollutant
shall be the difference between the
average concentrations of the pollutant
in the influent of the POTW, denoted by
I, and the average concentrations of the
pollutant in the effluent of the POTW,
denoted by E. divided by the average
concentrations of the pollutant in the
influent, denoted by I, as follows:,
I-E
The average concentrations of the
pollutant in the influent and effluent
shall be calculated by taking the
arithmetic average of all influent and
effluent data, respectively. In calculating
consistent removal under the
subparagraph, all sample data must be
used.
(ii) If a pollutant is only measurable in
some of the influent and effluent
samples (including the situation where it
is not measurable in any effluent
samples) and the POTW elects to
calculate consistent removal in
accordance with paragraph (b)(4)(i),
influent and effluent observations' below
the limit of detectability should be
assigned a value equal to the limit of
detectability. In calculating consistent
removal under paragraph (b)(4)(i), all
sample data, including those set at the
limit of detectability, must be used.
(iii) If a pollutant is only measurable
in some influent and effluent samples
(including the situation where it is not
measurable .in any effluent samples) and
the POTW elects not to calculate
consistent removal in accordance with
paragraph (b)(4)(i), or if a pollutant is
not measurable in any of the influent
samples (in which case the sample data
may not be used to calculate consistent
removal in accordance with paragraph
(b)(4)(i)), the POTW may (A) use
historical data as provided in paragraph
(b)(l) of this section to calculate
consistent removal, or (B) upon the
concurrence of the Approval Authority,
the POTW may use data from
treatability studies, demonstrated
removal at similar treatment facilities or
provide some other alternative means to
demonstrate its consistent removal.
(iv) For purposes of this paragraph,
"measurable" refers to the ability of the
analytical method to quantify as well as
identify the presence of'the pollutant in
question. "Limit of detectability" refers
to the lowest limit at which the
analytical method can quantify the
pollutant in question.
(c) Provisional credits. For pollutants
which are not being discharged
currently (i.e., new or modified facilities,
or production changes) the POTW may
apply for authorization to give removal
credits prior to the initial discharge of
the pollutant. Consistent removal shall
be based provisionally on data from
treatability studies or demonstrated
removal at other treatment facilities
where the quality and quantity of
influent are similar. Within 18 months
after the commencement of discharge of
A-ll
-------
Federal Register / Vol. 49. No. 151 / Friday. August 3. 1984 / Rules and Regulations 31223
pollutants in question, consistent
removal must be demonstrated pursuant
to the requirements of paragraph (b). If.
within 18 months after the
commencement of the discharge of the
pollutant in question, the POTW cannot
demonstrate consistent removal
pursuant to the requirements of
paragraph (b) of this section, the
authority to grant provisional removal
credits shall be terminated by the
Approval Authority and all Industrial
Users to whom the revised discharge
limits had been applied shall achieve
compliance with the applicable
categorical Pretreatment Standard(s)
within a reasonable time, not to exceed
the period of time prescribed in the
applicable categorical Pretreatment
Standard(a), as may be specified by the
Approval Authority,
(d) Exception to POTW Pretreatment
Program Requirement A POTW
required to develop a local pretreatment
program by § 403.8 may conditionally
give removal credits pending approval
of such a program hi accordance with
the following terms and conditions:
(1) All Industrial Users who are
currently subject to a categorical
Pretreatment Standard and who wish
conditionally to receive a removal credit
must submit to the POTW the
information required in 5 403.12(b)(lH7)
(except new or modified industrial users
must only submit the information
required by 1403.12(b)(lM6)).
pertaining to the categorical
Pretreatment Standard as modified by
the removal credit The Industrial Users
shall indicate what aditional technology,
if any, will be needed to comply with the
categorical Pretreatment Standard(s) as
modified by the removal credit;
(2) The POTW must have submitted to
the Approval Authority an application
for pretreatment program approval
meeting the requirements of §§ 403.8
and 403.9 in a timely manner, not to
exceed the time limitation set forth in a
compliance schedule for development of
a pretreatment program included in the
POTW's NPDES permit, but in not case
later than July 1,1983. where no permit
deadline exists:
(3) The POTW must:
(i) Compile and submit data
demonstrating its consistent removal in
accordance with paragraph (b) of this
section;
(ii) Comply with the conditions
specified in paragraph (a)(3) of this
section; and
(Hi) Submit a complete application for
removal credit authority in accordance
with paragraph (e) of this section;
(4) If a POTW receives authority to
grant conditional removal credits and
the Approval Authority subsequently
makes a final determination, after
appropriate notice, that the POTW
failed to comply with the conditions in
paragraphs (d)(2) and (3) of this section,
the authority to grant conditional
removal credits shall be terminated by
the Approval Authority and all
Industrial Users to whom the revised
discharge limits had been applied shall
achieve compliance with the applicable
categorical Pretreatment Standard(s)
within a reasonable time, not to exceed
the period of time prescribed in the
applicable categorical Pretreatment
Standard(s), as may be specified by the
Approval Authority.
(5) If a POTW grants conditional
removal credits and the POTW or the
Approval Authority subsequently makes
a final determination, after appropriate
notice, that the Industrial User(s) failed
to comply with the conditions in
paragraph (d)(l) of this section, the
conditional credit shall be terminated by
the POTW or the Approval Authority for
the non-complying Industrial User(s)
and the Industrial User(s) to whom the
revised discharge limits had been
applied shall achieve compliance with
the applicable categorical Pretreatment
Standard(s) within a reasonable time,
not to exceed the period of time
prescribed in the applicable categorical
Pretreatment Standard(s), as may be
specified by the Approval Authority.
The conditional credit shall not be
terminated where a violation of the
provisions of this paragraph results from
causes entirely outside of the control of
the Industrial User(s) or the Industrial
User(s) had demonstrated substantial
compliance.
(6) The Approval Authority may elect
not to review an application for
conditional removal credit authority
upon receipt of such application, in
which case the conditionally revised
discharge limits will remain in effect
until reviewed by the Approval
Authority. This review may occur at any
time in accordance with the procedures
of § 403.11. but in no event later than the
time of "any pretreatment program
approval or any NPDES permit
reissuance thereunder.
(e) POTW application for
authorization to give removal credits
and Approval Authority review—(!)
Who must apply. Any POTW that wants
to give a removal credit must apply for
authorization from the Approval
Authority.
(2) To whom application made. An
application for authorization to give
removal credits (or modify existing
ones) shall be submitted by the POTW
to the Approval Authority.
(3) When to apply. A POTW may
apply for authorization to give or modify
removal credits at any time.'
(4) Contents of the Application. An
application for authorization to give
removal credits must be supported by
the following information: -
(i) List of pollutants. A list of
pollutants for which removal credits are
proposed.
(ii) Consistent Removal Data. The
data required pursuant to paragraph (.b).
(iii) Calculation of revised discharge
limits. Proposed revised discharge limits
for each affected subcategory of
Industrial Users calculated in
accordance with paragraph (a)(4) of this
section.
(iv) Local Pretreatment Program
Certification. A certification that the
POTW has an approved local
pretreatment program or qualifies for
the exception to this requirement found
at paragraph (d) of this section.
(v) Sludge Management Certification.
A specific description of the POTW's
current methods of using or disposing of
its sludge and a certification that the
granting of removal credits will not
cause a violation of the sludge
requirements identified in paragraph
(a)(3)(iv) of this section.
(vi) NPDES Permit Limit Certification.
A certification that the granting of
removal credits will not cause a
violation of the POTW's NPDES permit
limits dnd conditions as required in
paragraph (a)(3)(v) of this section.
(5) Approval Authority Review. The
Approval Authority shall review the
POTW's application for authorization to
give or modify removal credits in
accordance with the procedures of
§ 403.11 and shall, in no event, have
more that 180 days from public notice of
an application to complete review.
(6) EPA review of State removal
credit approvals. Where the NPDES
State has an approved pretreatment
program, the Regional Administrator
may agree in the Memorandum of
Agreement under 40 CFR 123.24(d) to
waive the right to review and object to
submissions for authority to grant
removal credits. Such an agreement
shall not restrict the Regional
Administrator's right to comment upon
or object to permits issued to POTW's
except to the extent 40 CFR 123.24(d)
allows such restriction.
(7) Nothing in these regulations
precludes an Industrial User or other
interested party from assisting the
POTW in preparing and presenting the
information necessary to apply for
authorization.
(f) Continuation and withdrawal of
authorization—(1) Effect of
A-12
-------
31224
Federal. Register / Vol. 4a, No. 151 / Friday, August 3, 1984 / Ruiea and Regulations
authorization. (i> Once a POTW has
received' authorization to giant removal
credits for a particular pollutant ~
regulated is a categorical Pr-etreataiest
Standard it may automatically extend
that removal credit to the same pollutant
when it is regulated in other categorical
standards, unless granting the removal
credit will cause the POTW to violate
the sludge requirements identified in
(a](3](ivjo£ this, section or its NPDES
permit limits' and conditions as required
by (a)(3)M. tf a POTW elects at a later
time- to extend removal credits to a
certain categorical Ptetreatmeat
Standard industrial subcategory or one
or more Industrial Users that initially
were not granted removal credits, it
must notify the Approval Authority.
(2) Inclusion in POTW permit. Once
authority is granted, the removaf credits
shall be incraded in the POTW's NPDES
Permit as seen as> possible and shall
become an enforceable requirement of
the POTW's NPDES permit. The removal
Credits will remain in effect for the term
of the POTW's NPDES permit, provided
the POTW maintains compliance with
the conditions specified in subparagraph
(4) of this, paragraph.
(3) Comptiance monitoring. Following
authorization to give removal credits, a
POTW shall continue to monitor and
report on' (at such intervals as may be
specified by the Approval Authority, but
in no case less than once per year) the
POTW's removal capabilities. A
minimum of one representative sample
per month during the reporting period is
required, and all sampling data must be
included in the POTW's,compliance
report.
(4) Modification or withdrawal of
removal credits, (i) Compliance with the
conditions- ia paragraph (a)f3)(iiiHv) of
this section may be examined by the
Approval Authority whenever it- elects
and must, at the very least be examined
whenever th« POTW's NPDES permit ia
reissued. If the Approval Authority
determines, on the basis of compliance
monitoring reports or other information
availabk to it, that the conditions
specified in paragraphs (a)(3)(iii)-{v) of
this section are not being met, the-
Approval Authority shall withdraw the
POTWs authority to grant removal
credits on modify those credits- in
accordance with the procedures
specified in subparagraph (iii) below.
(ii) If, during the term of the POTWs
NPDES permit, the Approval Authority
determines that the POTWs. consistent
removal rate is consistently and
substantially lower than the removal
credit specified in the POTW's NPDES
permit, the Approval Authority shall
either withdraw the POTW's authority.
to grant-removal credits or modify those
credits in accordance with the
procedures specified in subparagraph
(iii} below.
(iii) If the Approval Authority
tentatively determines, under
subparagrapk* (i} or (ii) above-, that the
withdrawal of a POTWa authority to
grant removal credits or modification of
those- credit* ia warranted, the Approval
Authority shall, in accordance with the
procedures specified in f 403.11(b) (1)
and (2) of this section, issue a public
notice, provide a public comment period
of at least 30 days and provide an
opportunity for interested persona to
request a public hearing. The mailing list
foe the public notice shall include, at a
minimum, the POTW and Industrial
Users to whom revised discharge limits
have been applied. If the Approval
Authority finally determines to
withdraw the POTW's authority to grant
removal credits or to modify those
removal credits the POTW is authorized
to grant it shall notify the POTW, all
Industrial Users to whom revised limits
have been applied and each person who
has requested individual notice of its
decision and the basis for that decision.
Notice shall also be published in the
same newspaper as the original notice
of the tentative determination was
published. Following such notice and
modification or withdrawal, all
Industrial Users to whom revised
discharge limits have been applied shall
be subject to the modified discharge
limits or the discharge limits prescribed
in the applicable categorical
Pretreatment Standard(s), as
appropriate, and shall achieve
compliance-with such limits within a
reasonable time, not to exceed the
period of time prescribed in the
applicable- categorical Pretreatment
StandardfaJ, a* may be specified by the
Approval Authority.
(g) Removal credits in State-run
pretreatmenl programs under
§ 403.10(e). Where an NPDES State with
an approved pretreatraent program
elects to implement a local pretreatment
program in lieu or requiring the POTW
to develop such a program (as provided
in | 403.10{e)}. the POTW wiil not be
required to develop a pretreatment
program as a precondition to obtaining
authorization to give removal credits.
The PQTW will, however, be required to
comply with the-other conditions of
paragraph (a)(3) of this section.
3. 40 CFR 403.6(a)(2)(ii) is revised to
read as follows:
§ 403.S National Pretreatment Standard*:
Categorical Standard*.
(2) • - *
(ii) Citing evidence and reasons- why a
particular subcategory is applicable and
why others are not applicable. Eacfr
such statement shall contain an oath
stating-that the facts contained therein
are true on the basis of the applicant's
personal knowledge or to the best of his
information and belief.
* * ' * * *
4. In 40 CFR 403.8, paragraph (a) is
revised and paragraph (e)(6) ia added to
read as follows:
§ 403.8 POTW pratreatmmt programs.
Development by POTW.
(a) POTWs. required to develop a
pretreatment program. Any POTW (or
combination of POTWs operated by the
same authority) with a total design flow
greater than 5 million gallons per day
(mgd) and receiving, from Industrial
Users pollutants which Pass Through or
Interfere with the operation of the
POTW or are otherwise subject to
Pretreatment Standards will be required
to establish a POTW Pretreatment
Program unless the NPDES State
exercises its option to assume local
responsibilities as provided for in
§ 403.10(e). The Regional Administrator
or Director may require that a POTW
with a design flow of 5 mgd or less
develop a POTW Pretreaiment Program
if he or she finds that the nature or
volume of the industrial influent
treatment process upsets, violations of
POTW effluent limitations..
contamination of municipal sludge, or
other circumstances warrant in order to
prevent Interference with the POTW or
Pass Through.
*****
(e) * *- * ' -
(6) incorporate the removal credits
(established under § 403.7) in the POTW
permit.
*****
5. In 40 CFR 403.11, the introductory
text, paragraph (a), and the introductory
text of paragraph (b) are all revised.
Paragraph (b)(3) is removed.
§ 403.11 Approval procedures for POTW
pretreatment program* and POTW granting
of removal credits.
The following procedures shall be
adopted in approving or denying
requests for approval of POTW
Pretreatment Programs and applications
for removal credit authorization:
(a) Deadline for review of submission.
The. Approval Authority shall have 9ft
days from the date of public notice- of
any Submission complying with the
requirements ol J 40i9fbJ and, where.
removal credit authorizatioa i» soughf
A-13
-------
Federal Register / Vol. 49. No. 151 / Friday. August 3. 1984 / Rules and Regulations 31225
with |§ 403.7(d) and 403.9(d), to review
the Submission. The Approval Authority
shall review the Submission to
determine compliance with the__
requirements of § 403.8 (b) and (f). and,
where removal credit authorization is
sought, with I 403.7. The Approval
Authority may have up to an additional
90 days to complete the evaluation of
the Submission if the public comment
period provided for in paragraph
(b)(l)(ii) of this section is extended
beyond 30 days or if a public hearing is
held as provided for in paragraph (b)(2)
of this section. In no event, however.
shall the time for evaluation of the
Submission exceed a total of 180 days
from the date of public notice of a
Submission meeting the requirements of
§ 403.9(b) and. in the case of a removal
credit application. §§ 403.7(d) and
403.9(b).
(b) Public notice and opportunity for
hearing. Upon receipt of a Submission
the Approval Authority shall commence
Its review. Within 5 days after making a
determination that a Submission meets
the requirements of § 403.9(b], and.
where removal credit authorization is
sought, §§ 403.7(d) and 403.9(d). the
Approval Authority shall:
§ 403.12 [Amended]
6.40 CFR 403.12 is amended by
removing paragraphs (i) and (j) and
redesignating the remaining paragraphs
(k)-{n} as (i)-(l) accordingly.
7. A new Appendix E is added to 40
CFR Part 403 and reads as follows:
Appendix E—Sampling Procedures
I. Composite Method
A. It is recommended that influent and
effluent operational data be obtained through
24-hour flow proportional composite samples.
Sampling may be done manually or
automatically, and discretely or continuously.
If discrete sampling is employed, at least 12
aliquots should be composited. Discrete
sampling may be flow proportioned either by
varying the time interval between each
aliquot or the volume of each aliquot. All-
composites should be flow proportional to
either the stream flow at the time of
collection of the influent aliquot or to the
total influent flow since the previous influent
aliquot. Volatile pollutant aliquots must be
combined in the laboratory immediately
before analysis.
B. Effluent sample collection need not be
delayed to compensate for hydraulic
detention unless the POTW elects to include
detention time compensation or unless the
Approval Authority requires detention time
compensation. The Approval Authority may
require that each effluent sample is taken
approximately one detention time later than
the corresponding influent sample when
failure to do so would result in an
unrepresentative portrayal of actual POTW
operation. The detention period should be
based on a 24-hour average daily flow value.
The average daily flow should in turn be
based on the average of the daily flows
during the same month of the previous year.
II. Grab Method
If composite sampling is not an appropriate
technique, grab samples should be taken to
obtain influent and effluent operational data.
A grab sample is an individual sample
collected over a period of time not exceeding
15 minutes. The collection of influent grab
samples should precede the collection of
effluent samples by approximately one
detention period except that where the
detention period is greater than 24 hours such
staggering of the sample collection may not
be necessary or appropriate. The detention
period should be based on'a 24-hour average
daily flow value. The average daily flow
should in turn be based upon the average of
the daily flows during the same month of the
previous year. Grab sampling should be
employed where the pollutants being
evaluated are those, such as cyanide and
phenol, which may not be held for an
extended period because of biological.
chemical or physical interaction which take
place after sample collection and affect the
results.
[FR Doc. 84-2M33 Filed 8-2-84: 8:45 am|
BILLING COOK S5W-50-M
A-14
-------
Appendix B
Detection Levels for
Priority Pollutants
-------
-------
Appendix B
Method Detection Levels for Priority Pollutants
PRIORITY POLLUTANT
a
Detection EPA
Level (ug/L) Method
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
acenaphthene
acrolein
acrylonitrile
benzene
benzidine
carbon tetrachloride
chlorobenzene
1,2, 4-trichlorobenzene
hexachloro benzene
1 ,2-dichloroethane
1 , 1 , 1-trichloroethane
hexachloroethane
1 , 1-dichloroethane
1,1, 2-trichloroethane
1, 1,2,2-tetrachloroethane
chloroe thane
bis (2-chloroethyl) ether
2-chloroethyl vinyl ether (mixed)
2-chloronaphthalene
2,4,6-trichlorophenol
parachlorometa cresol
chloroform (trichloromethane)
2— chlorophenol
1 ,2-dichlorobenzene
1 , 3-dichlorobenzene
1 , 4-dichlorobenzene
3,3-dichlorobenzidine
1 , 1-dichloroethylene
1 , 2-trans-dichloroethylene
2 , 4-dichlorophenol
1 ,2— dichloropropane
1,2-dichloropropylene (trans 1 ,3-dichloropropene)
2 , 4-dime thylphenol
2, 4-dinitro toluene
2,6-dinitrotoluene
1 ,2-diphenylhydrazine
ethylbenzene
f luoranthene
4-chlorophenyl phenyl ether
4-bromophenyl phenyl ether
1.8
0.6
0.5
0.2
0.08
0.12
0.25
0.05
0.05
0.03
0.03
1.6
0.07
0.02
0.03
0.52
0.3
0.13
1.9
0.64
0.36
0.05
0.31
0.15
0.32
0.24
0.13
0.13
0.1
0.39
0.04
0.34
0.32
0.02
0.01
b
0.2
0.21
3.9
2.3
610
603
603
602
605
601
601
612
612
601
601
625
601
601
601
601
611
601
625
604
604
601
604
601
601
601
605
601
601
604
601
601
604
609
609
b
602
610
611
611
B-l
-------
Method Detection Levels for Priority Pollutants
(Continued)
PRIORITY POLLUTANT
Detection EPA
Level (ug/L) Method
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
67.
68.
69.
70.
71.
72.
73.
74.
75.
76.
77.
78.
79.
80.
81.
82.
bis (2-chlorisopropyl) ether
bis (2-chloroethoxy) methane
methylene chloride (dichlorome thane)
methyl chloride (chlorome thane)
methyl bromide (bromome thane)
bromoform (tribromomethane)
dichlorobromome thane
chlorodibromomethane
hexachloro butadiene
hexachlorocyclopentadiene
isophorone
naphthalene
nitrobenzene
nitro phenol
4-nitrophenol
2 , 4-dini tro pheno 1
4 , 6-dinitro-o-cresol
N-nitrosodimethylamine
N-nitrosodiphenylamine
N-nitrosodi-n-propylamine
pentachlorophenol
phenol
bis (2-ethylhexyl) phthalate
butyl benzyl phthalate
di-n-butyl phthalate
di-n-octyl phthalate
diethyl phthalate
dimethyl phthalate
benzo (a) anthracene ( 1,2-benzanthracene)
benzo (a) pyrene (3 ,4-benzopyrene)
3 ,4-benzof luoranthene
benzo (k) fluoranthane (11, 12-benzof luoranthene)
chrysene
acenaphthylene
anthracene
benzo (ghi) perylene (1, 12-benzoperylene)
f luorene
phenanthrene
dibenzo (a,h) anthracene (1 ,2,5,6-dibenzanthracene)
indeno (1,2,3-cd) pyrene (2,3-o-phenylenepyrene)
pyrene
tetrachloroethylene
0.8
0.5
0.25
0.08
1.18
0.2
0.1
b
0.34
—
5.7
1.8
3.6
0.45
2.8
13.0
16.0 ,
0.15
0.81
0.46
7.4
0.14
2.0
0.34
0.36
3.0
0.49
0.29
0.013
0.023
0.018
0.017
0.15
2.3
0.66
0.076
0.21
0.64
0.03
0.043
0.27
0.03
611
611
601
601
601
601
601
601
612
r>
609 FID
610
609 FID
604
604
604
604
607
607
607
604
604
606
606
606
606
606
606
610 HPLC
610 HPLC
610 HPLC
610 HPLC
610 HPLC
610 HPLC
610 HPLC
610 HPLC
610 HPLC
610 HPLC
610 HPLC
610 HPLC
610 HPLC
601
B-2
-------
Method Detection Levels for Priority Pollutants
(Continued)
83.
84.
85.
86.
87.
88.
89.
90.
91.
92.
93.
94.
95.
96.
97.
98.
99.
100.
608
101.
102.
ios.
104.
105.
106.
107.
108.
109.
110.
111.
112.
113.
114.
115.
116.
117.
118.
119.
120.
121.
122.
123.
PRIORITY POLLUTANT3
toluene
trichloroethylene
vinyl chloride (chloroethylene)
aldrin
dieldrin
chlordane (technical mixture & metabolites)
4, 4 '-DDT
4, 4 '-DDE (p, p'-DDX)
4, 4 '-ODD (p, p'-TDE)
Alpha-endosulfan
Beta-endosulfan
endosulfan sulfate
endrin
endrin aldehyde
heptachlor
heptachlor epoxide
Alpha-BHC
Beta-BHC
Gamma-BHC (lindane)
Delta-BHC
PCB-1242 (Arochlor 1242)
PCB-1254 (Arochlor 1254)
PCB-1221 (Arochlor 1221)
PCB-1232 (Arochlor 1232)
PCB-1248 (Arochlor 1248)
PCB-1260 (Arochlor 1260)
PCB-1016 (Arochlor 1016)
toxaphene
antimony (total)
arsenic (total)
asbestos (fibrous)
beryllium (total)
cadmium (total)
chromium (total)
copper (total)
cyanide (total)
lead (total)
mercury (total)
nickel (total)
selenium (total)
silver (total)
Detection
Level (ug/L)
0.2
0.12
0.18
0.004
0.002
0.014
0.012
0.004
0.011
0.014
0.004
0.066
0.006
0.023
0.003
0.083
0.003
0.006
0.004
0.009
0.065
b
b
b
b
b
b
0.24
10
10
b
1
1
5
1
20
10
0.2
10
5
1
EPA
Method
602
601
601
608
608
608
608
608
608
608
608
608
608
608
608
608
608
608
608
608
608
608
608
608
608
608
608
FUR6
FUR
FLAMEf
FUR
FUR
FUR
DISTg
FUR,
cvh
FUR
FUR
FUR
B-3
-------
Method Detection Levels for Priority Pollutants
(Continued)
PRIORITY POLLUTANT0
Detection EPA
Level (ug/L) Method
124. thallium (total)
125. zinc (total)
126. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)
10
1
0.003
FUR
FUR
This numbering does not correspond with numbers on EPA's list of pri-
ority pollutants.
No detection limit determined.
Flame ionization detection (FID).
High pressure liquid chromatography (HPLC).
Furnace (FUR).
Flame (FLAME).
Distillation (DIST).
Cold vapor (CV).
b
c
d
e
f
g
h
Source: "Methods for Organic Chemical Analysis of Municipal and Industrial
Wastewater," Environmental Monitoring and Support Laboratory,
Cincinnati, OH 45268. EPA-600/4-82-057. July 1982.
This table lists the analytical methods and appropriate method
detection limits for the EPA priority pollutants. The information
contained in "Methods for Organic Chemical Analysis of Municipal and
Industrial Wastewater" represents an effort to provide procedures
that are as uniform and cost effective as practical for a wide
cross-section of chemical compound classes. Due to the variable
chemical and physical properties of the parameters, some compromises
had to be made. Therefore, in some of the methods, the extraction
procedures, cleanup procedures and determinative steps are not
optimum for all parameters.
B-4
-------
Appendix C
Model Removal Credit Application
-------
-------
Model Removal Credit Application
Introduction
The Proppa City Sewerage District (PCSD) hereby requests authorization to
grant removal credits under the provisions of 40 CFR 403.7 as revised on
August 3, 1984. PCSD has had relatively few problems with upsets or inter-
ference at its treatment plants and metal levels in the sludge are relatively
low. Although removal rates of chromium at the treatment plants are
consistently high in most cases, the removal rate requested has been reduced
25 percent to allow for a safety margin which should ensure that PCSD will
consistently achieve the proposed removals. The District certifies that these
removal credits, if granted to its industries, will not adversely affect the
treatment processes at the plants or sludge disposal methods, or cause a
violation of its NPDES permit limits and conditions or of sludge requirements
as defined in 40 CFR 403.7(a)(l)(ii).
PCSD's application follows the application requirements specified in 40
CFR 403.7(e)(6) as revised in August 1984. Treatment plant analytical data
have been collected for the last 12 months as required by the regulation. Any
questions regarding the data or other information in this application should
be addressed to Ray Topper, Pretreatment Unit Chief, 618-618-6186.
1. List of Pollutants
PCSD requests authorization to grant removal credits for chromium.
2. Consistent Removal Data
PCSD operates two wastewater treatment plants, Rio Creek and Maine River
Plants. Both plants have secondary treatment and employ activated sludge
processes. PCSD collected 12 samples of the influent and effluent from its
two treatment plants at approximately the same time of the month for the last
12 months (October 1983 - September 1984). Analytical results of the sampling
and flow data for the sampling days are shown in Tables 1 and 2. Where the
pollutant was not detected or was detected but could not be assigned a
quantitative concentration in a sample, a value equal to the limit of detect-
ability was assigned to the sample. Sampling was conducted in accordance with
C-l
-------
Table 1
Analytical Data for Chromium for the Rio Creek Plant
Sample Date
Chromium Concentration (ug/1)
Influent Effluent
Flow Rate (mgd)
10/15/83
11/15/83
12/15/83
1/15/84
2/15/84
3/15/84
4/15/84
5/15/84
6/15/84
7/15/84
8/15/84
9/15/84
42
32
36
22
44
48
12
22
32
34
18
18
18
8
13
7
12
20
ND
4
9
11
ND
17
6.2
5.8
6.3
6.7
6.4
5.3
5.1
5.2
6.0
6.4
6.4
6.6
Average Influent
Cone. (I) = 31.66
Average Effluent
Cone. (E) = 10.25
ND - Not Detected (the limit of detectability, 1 ug/1, was used)
C-2
-------
Table 2
Analytical Data for Chromium for the Maine River Plant
Sample Date
Chromium Concentration (ug/1)
Influent Effluent
Flow Rate (mgd)
10/10/83
11/10/83
12/10/83
1/10/84
2/10/84
3/10/84
4/10/84
5/10/84
6/10/84
7/10/84
8/10/84
9/10/84
1600
600
850
920
1230
470
440
590
1050
1230
960
1110
640
320
270
310
560
510
240
190
580
590
360
550
10.3
8.1
9.7
10.8
11.0
9,6
8.9
7.9
11.8
10.2
11.7
9.9
Average Influent
Cone. (I) = 920.8
Average Effluent
Cone. (E) =» 426.6
C-3
-------
methods suggested in Appendix E of the removal credits regulation. Samples
were analyzed in accordance with techniques prescribed in 40 CFR 136.
The consistent removal rates for the treatment plants were calculated
using the following formula: .
where: r - consistent removal percentage rate for a pollutant ,
I » average concentration of the pollutant in the influent
E « average concentration of the pollutant in the effluent
The calculations for the Rio Creek plant is :
31.66 - 10.25 _,
— «•; •f'7 -
-31 . DO
The calculation for the Maine River plant is:
_ _ 920.8 - 426.6
920.8
.54 = 54%
PCSD intends to use the lower removal percentage, 54 percent, as the
removal rate for the entire system. This will allow a uniform set of revised
standards to be employed for the entire system (as opposed to revising two
sets of standards for industrial users discharging to the two plants).
3. Calculation of Revised Discharge Limits
The industrial categories and subcategories for which chromium discharge
limits would be revised are the following:
Industrial Category/Subcategory No. lUs
Electroplating 5
(All subcategories have same limitations)
Metal Finishing 4
(All subcategories have same limitations)
Leather Tanning and Finishing 2
Subpart D Retan - Wet Finish Sides 1
Subpart H Pigskin 1
C-4
-------
To allow itself and the industrial users a margin of safety, PCSD elects to
use a removal rate 25 percent less than shown at the treatment plant.
Therefore, a rate of 40.5 percent will be used for its removal credit applica-
tion. This removal rate is then used to revise the discharge limit specified
in the categorical pretreatment standard using the following formula:
where: y = revised discharge limit
x = pollutant discharge limit specified in the categorical pretreat-
ment standard
r = consistent removal rate = 40.5 percent
As an example, the calculation for the maximum discharge limit for any one day
for chromium in the Electroplating Standards is:
The revised discharge limit for chromium is 11.8 mg/1.
The revised discharge limits for all the affected industrial users are
shown below.
Electroplating
Metal Finishing
Leather Tanning and Finishing
Subpart D
Subpart H
Chromium Limitations (mg/1)
Maximum for Any One Day Average
Standard Revised Standard Revised
7.0
2.77
19
12
11.8
4.65
31.9
20.2
4.0
1.71
12
8
6.7
2.87
20.2
13.4
4. Local Pretreatment Certification
I certify that PCSD received approval of its pretreatment program on June
6, 1984 and that the PCSD pretreatment program is adequately staffed and
C-5
-------
funded to carry out the duties and responsibilities of a POTW as specified in
40 CFR 403.
Ray Topper
Pretreatment Unit Chief
5. Sludge Management Certification
PCSD currently disposes of the sludge from its two treatment plants in
the Mid-State Regional Landfill after digestion and vacuum filtration. The
regulations that apply to this disposal method are the Mid-State Regional
Landfill regulations and the solid and hazardous waste regulations promulgated
under authority of the Resource Conservation and Recovery Act (RCRA).
Under RCRA, if sludge is determined to be a hazardous waste, sludge
handling and disposal must comply with special design and operating standards.
The only likely reason the sludge would be a hazardous waste is if it
exhibited the characteristic of EP toxicity (40 CFR 261.24). The filtered
sludge from the two plants was tested for EP toxicity in June and July of 1984
using the procedures specified by EPA and none of the sludges was determined
to be a hazardous waste. The pollutant closest to the maximum concentration
allowed in the test, lead, was over ten times less than the limit.
Granting removal credits for chromium will result in increased
concentrations of chromium to the treatment plants. If other unregulated
pollutants (particularly other metals) are discharged by facilities receiving
removal credits, concentrations of those pollutants may also rise. To the
extent higher concentrations of metals are removed from the wastewater, they
will result in higher concentrations in the treated sludge. It is difficult
to estimate the increased concentration of other pollutants that will result
from removal credits for chromium and the effect the combined rise in pollu-
tant concentration will have on EP toxicity. Due to the large margin of
current compliance, however, PCSD is confident that the increased pollutant
loadings caused by granting removal credits for chromium will not cause the
sludge to exhibit characteristics of EP toxicity.
C-6
-------
The Mid—State Regional Landfill regulations specify that municipal
sludges disposed of in the landfill cannot contain greater than 10,000 mg/kg
of chromium. Violations of this limit occurred occasionally prior to devel-
opment of the PCSD pretreatment program and compliance with the categorical
standards by the electroplating and leather tanning facilities in the City.
It now appears that if removal credits are granted, compliance with applicable
disposal regulations will be maintained. This can be demonstrated by the
following discussion and calculations.
The procedure for assuring that compliance with sludge disposal methods
will continue to be achieved after the categorical standards are revised is to
calculate the maximum increase of metals in the sludge due to the standards
revision and to determine if compliance with sludge disposal regulations will
be maintained. This discussion will center on the sludge from the Maine River
Plant because of the relatively higher levels of chromium in its sludge.
The first step is to calculate the increase in chromium from the indus-
trial users in each industrial category. For the Electroplating category,
this was done by taking the difference between the revised and original
discharge limit and multiplying by the total categorical industry electro-
plating process wastewater flow rate into the Maine River Plant. The total
maximum regulated process flow rate from all of the categorical electroplating
facilities is 270,000 gpd. Therefore the calculation is as follows:
270,000 gpd x (11.8 - 7.0)mg/l x 3.78 1/gal = 4,898,880 ing/day
Since the Metal Finishing Standards are not yet in effect and the Electro-
plating Standards apply to all the metal finishing facilities, there is no
need to calculate the increase of chromium from these facilities.
The maximum regulated process flow rates from the Subpart D and H Leather
Tanning and Finishing facilities are 135,000 gpd and 86,000 gpd, respectively.
The calculations for these facilities are:
Subpart D: 135,000 gpd x (31.9 - 19)mg/l x 3.78 1/gal = 6,582,870 mg/day
Subpart H: 86,000 gpd x (20.2 - 12)mg/l x 3.78 1/gal - 2,665,656 mg/day
C-7
-------
Total chromium discharged for all electroplating and leather tanning and
finishing facilities is 14,147,406 rag/day.
The average removal rate of chromium at the Maine River Plant is 54
percent. Therefore, this percentage of the projected increase of chromium
would be deposited in the sludge. The total maximum increase of chromium in
the sludge would be 54 percent of 14,147,406 mg/day or 7,634,600 mg/day.
'- * .
Dividing this figure by the number of kilograms of sludge generated by the
Maine River Plant per day (50,980 kg/day) gives an increase of chromium in the
sludge of 150 mg/kg.
The highest recorded level of chromium in the Maine River Plant sludge
since the last of the industrial users discharging chromium to the plant
installed a pretreatment system (this occurred on May 18, 1984) was 7,863
mg/kg on June 15, 1984. When the maximum increase attributable to the removal
credit is added to the maxium level of chromium found in the sludge, a value
of 8,013 mg/kg is obtained. This potential maximum level of chromium in the
sludge is less than the Mid-State Regional Landfill limit of 10,000 mg/kg.
Therefore, compliance with applicable sludge disposal regulation should be
maintained. Furthermore, PCSD will continue to monitor chromium in the sludge
after the categorical standards are revised to ensure that applicable sludge
disposal regulations will be met.
I certify, based upon my inquiry of those individuals immediately
responsible for the above demonstration and for operation of the PCSD pre-
treatment program and treatment plants operations, that PCSD will continue to
achieve compliance will all applicable sludge disposal regulation after
categorical standards are revised.
Ray Topper
Pretreatment Unit Chief
C-£
-------
6. NPDES Permit Limit Certification
PCSD has had very few problems at its two treatment plants. Both plants
are meeting their NPDES permit limits and conditions consistently. To provide
assurance that the treatment plants will continue to meet their NPDES permit
limits and conditions after categorical standards are revised, the maximum
increase of chromium in the influent to the plants will be calculated and the
potential effects on the treatment plants evaluated. This discussion will
only cover the Maine River Plant because the influent to the Rio Creek Plant
has relatively low levels of chromium. A two or threefold increase of
chromium in the Rio Creek Plant influent, although highly unlikely, would have
little effect on the plant's operations and treatment efficiency.
The first step is to determine the maximum level of chromium in the
influent to the plant after categorical standards revision. The increase of
chromium in the influent to the plant is calculated dividing,the increase of
chromium discharged to the system due to revising the categorical standards
(as determined in the previous section) by the approximate average flow for
the Maine River Plant (10 MGD) as shown below:
"."7,406 X 10 MGD x 3,785 I/gal = '37 ***'*
The maximum concentration at the influent to the plant that has occurred since
the last of the industrial users discharging chromium to the plant installed a
pretreatment system was 1,230 ug/1 (1.23 mg/1) on July 10, 1984. Therefore
the maximum projected plant influent concentration is 1.60 mg/1 (1.23 +
.37 mg/1). This maximum projected influent is then used to determine if the
activated sludge or anaerobic sludge digestion processes used at the plant
will be inhibited.
The chromium removal efficiency of the primary clarifier (.27) is used to
determine the influent concentration to the activated sludge process by the
following calculation:
1.6 mg/1 (1-.27) = 1.168 mg/1
C-9
-------
Checking this concentration with the threshold concentration for chromium of
10 mg/1 in the EPA document, Guidance Manual for POTW Pretreatment Program
Development (October 1983), it is unlikely that the activated sludge process
will be inhibited. . -. /
To check that the anaerobic digestion process will not be inhibited, the
concentration of chromium at the influent to the digestors must be calculated.
Using the average removal rate for chromium (54 percent) as the proportion of
chromium entering the digestors, and the flow rate to the digestors (.l.mgd),
the influent to the digestors can be derived by the following calculation:
.54 x
(10 mgd) 1.60 mg/1
(.1 mgd)
86;4 mg/1
Checking this value with the threshold value for anaerobic sludge digestion, of
100 mg/1 from the same reference above shows that the anaerobic digestion
process should not be inhibited.
There are no chromium discharge limits in the NPDES permits for the Main
River of Rio Creek Plants. However, as a final check, the maximum projected
plant effluent concentration of chromium based on the maximum projected plant
influent concentration will be determined to check that water quality criteria
will continue to be met after revision of the categorical standards. The
plant effluent concentration is (1-.54) times the plant influent concentra-
tion, therefore the maximum projected effluent concentration is .46 x 1.6Q
mg/1 or .736 mg/1. The receiving stream flow rate (Maine River) is 100 mgd
giving a dilution ratio of 10:1 thus reducing the maximum concentration of
chromium in the river to .0736 mg/1 or 73.6 ug/1. Comparing this value with
the water quality criteria for total chromium for the Maine River of 100 ug/1,
it appears that water quality criteria will continue to be met after the
categorical standards are revised.
C-10
-------
(REVISED 7/26/85)
••• I, certify, based upon my inquiry of those individuals immediately ?i; ~'
responsible for the above demonstration and for operation of the PCSD:-pr'e;- '
treatment program and treatment plants, that PCSD will not violate any of its
NPDES permit limits and conditions after categorical standards are revised.
Ray,Topper
Pretreatment Unit Chief
Note: This certification addresses POTW effluent limits for pollutants
subject to removal credits.
C-ll
-------
-------
Appendix D
Sample NPDES Permit
Modification Language for
Removal Credits
-------
-------
Sample NPDES Permit Modification
Language for Removal Credits
The Permittee is hereby authorized to modify the national categorical
pretreatment standard pursuant to Title 40 of the Code of Federal Regulations
Section 403.7 (40 CFR 403.7). This authority is granted contingent upon the
Permittee's continued compliance with the demonstrated removal rates for the
pollutants shown below and as documented in the Permittee's application dated
and any data submitted in support thereof. This author-
ity to modify only extends to those pollutants and industrial categories. The
Permittee, with prior notice to the Approval Authority, may extend the removal
credit to other categorical pretreatment standards as they become applicable
provided the extension will not cause the Permittee to violate its NPDES
permit-or applicable sludge management requirements.
APPROVED REMOVAL RATE(S)
Pollutant Parameter Removal Rate
The Permittee will comply with the following sampling and reporting
requirements in order to demonstrate continued adherence to its stated
consistent removal rate and compliance with:
• Influent and effluent sampling, at least once per month or as more
frequently as necessary to show consistent removal
• Permittee will report the results of its influent and effluent
sampling at least once per year in its annual compliance report or
more often as the Approval Authority requires.
• [May be other requirements or stipulations as deemed necessary by the
Approval Authority, (e.g., rolling 12-month average)]
Unless otherwise modified or withdrawn as provided in 40 CFR 403.7(f)(4), the
authority granted herein shall remain effective until the expiration of this
NPDES permit.
Note: This sample language only applies to the approved removal rates, and
does not apply to monitoring that must be performed by the POTW to
demonstrate compliance with any toxic limits in the NPDES permit.
D-l
*H.S. GOVERNMENT PRINTING OFFICE : 1985 0-482-596/32694-
-------
*•- ••"•
-------