[Code of Federal Regulations]
[Title 40, Volume 28]
[Revised as of July 1, 2006]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR403.7]
[Page 20-27]
TITLE 40--PROTECTION OF ENVIRONMENT
CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
PART 403_GENERAL PRETREATMENT REGULATIONS FOR EXISTING AND NEW SOURCES OF
POLLUTION--Table of Contents
Sec. 403.7 Removal credits.
(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 following 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
[[Page 21]]
paragraph (a)(4) of this section. 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 only if the following conditions are
met:
(i) 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.
(ii) Consistent removal determination. The POTW demonstrates and
continues to achieve consistent removal of the pollutant in accordance
with paragraph (b) of this section.
(iii) 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. Removal credits may be made available
for the following pollutants.
(A) For any pollutant listed in appendix G section I of this part
for the use or disposal practice employed by the POTW, when the
requirements in 40 CFR part 503 for that practice are met.
(B) For any pollutant listed in appendix G section II of this part
for the use or disposal practice employed by the POTW when the
concentration for a pollutant listed in appendix G section II of this
part in the sewage sludge that is used or disposed does not exceed the
concentration for the pollutant in appendix G section II of this part.
(C) For any pollutant in sewage sludge when the POTW disposes all of
its sewage sludge in a municipal solid waste landfill unit that meets
the criteria in 40 CFR part 258.
(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:
[GRAPHIC] [TIFF OMITTED] TC15NO91.014
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 Credits; Demonstration of Consistent
Removal--(1) Definition of Consistent Removal. ``Consistent Removal''
shall mean the average of the lowest 50 percent of the removal measured
according to paragraph (b)(2) of this section. All sample data obtained
for the measured pollutant during the time period prescribed in
paragraph (b)(2) of this section must
[[Page 22]]
be reported and used in computing Consistent Removal. If a substance is
measurable in the influent but not in the effluent, the effluent level
may be assumed to be the limit of measurement, and those data may be
used by the POTW at its discretion and subject to approval by the
Approval Authority. If the substance is not measurable in the influent,
the date may not be used. Where the number of samples with
concentrations equal to or above the limit of measurement is between 8
and 12, the average of the lowest 6 removals shall be used. If there are
less than 8 samples with concentrations equal to or above the limit of
measurement, the Approval Authority may approve alternate means for
demonstrating Consistent Removal. The term ``measurement'' refers to the
ability of the analytical method or protocol to quantify as well as
identify the presence of the substance in question.
(2) Consistent Removal Data. Influent and effluent operational data
demonstrating Consistent Removal or other information, as provided for
in paragraph (b)(1) of this section, which demonstrates Consistent
Removal of the pollutants for which discharge limit revisions are
proposed. This data shall meet the following requirements:
(i) Representative Data; Seasonal. The data shall be representative
of yearly and seasonal conditions to which the POTW is subjected for
each pollutant for which a discharge limit revision is proposed.
(ii) Representative Data; Quality and Quantity. The data shall be
representative of the quality and quantity of normal effluent and
influent flow if such data can be obtained. If such data are
unobtainable, alternate data or information may be presented for
approval to demonstrate Consistent Removal as provided for in paragraph
(b)(1) of this section.
(iii) Sampling Procedures: Composite. (A) The influent and effluent
operational data shall be obtained through 24-hour flow-proportional
composite samples. Sampling may be done manually or automatically, and
discretely or continuously. For discrete sampling, at least 12 aliquots
shall 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 must be flow-proportional to each stream flow at
time of collection of 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)(1) Twelve samples shall be taken at approximately equal
intervals throughout one full year. Sampling must be evenly distributed
over the days of the week so as to include no-workdays as well as
workdays. If the Approval Authority determines that this schedule will
not be most representative of the actual operation of the POTW Treatment
Plant, an alternative sampling schedule will be approved.
(2) In addition, upon the Approval Authority's concurrence, a POTW
may utilize an historical data base amassed prior to the effective data
of this section provide that such data otherwise meet the requirements
of this paragraph. In order for the historical data base to be approved
it must present a statistically valid description of daily, weekly and
seasonal sewage treatment plant loadings and performance for at least
one year.
(C) 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 be 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 is to be based on a 24-hour average daily flow value. The average
daily flow used will be based upon the average of the daily flows during
the same month of the previous year.
(iv) Sampling Procedures: Grab. Where composite sampling is not an
appropriate sampling technique, a grab sample(s) shall be taken to
obtain influent and effluent operational data. Collection of influent
grab samples should precede collection of effluent samples
[[Page 23]]
by approximately one detention period. The detention period is to be
based on a 24-hour average daily flow value. The average daily flow used
will be based upon the average of the daily flows during the same month
of the previous year. Grab samples will be required, for example, where
the parameters being evaluated are those, such as cyanide and phenol,
which may not be held for any extended period because of biological,
chemical or physical interactions which take place after sample
collection and affect the results. A grab sample is an individual sample
collected over a period of time not exceeding 15 minutes.
(v) Analytical methods. The sampling referred to in paragraphs
(b)(2) (i) through (iv) of this section and an analysis of these samples
shall be performed in accordance with the techniques prescribed in 40
CFR part 136 and amendments thereto. Where 40 CFR part 136 does not
contain sampling or analytical techniques for the pollutant in question,
or where the Administrator determines that the part 136 sampling and
analytical techniques are inappropriate for the pollutant in question,
sampling and analysis shall be performed using validated analytical
methods or any other applicable sampling and analytical procedures,
including procedures suggested by the POTW or other parties, approved by
the Administrator.
(vi) Calculation of removal. All data acquired under the provisions
of this section must be submitted to the Approval Authority. Removal for
a specific pollutant shall be determined either, for each sample, by
measuring the difference between the concentrations of the pollutant in
the influent and effluent of the POTW and expressing the difference as a
percent of the influent concentration, or, where such data cannot be
obtained, Removal may be demonstrated using other data or procedures
subject to concurrence by the Approval Authority as provided for in
paragraph (b)(1) of this section.
(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 pollutants in question, consistent removal
must be demonstrated pursuant to the requirements of paragraph (b) of
this section. 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(s), 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 Sec. 403.8 may
conditionally give removal credits pending approval of such a program in
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 Sec.
403.12(b)(1) through (7) (except new or modified industrial users must
only submit the information required by Sec. 403.12(b)(1) through (6)),
pertaining to the categorical Pretreatment Standard as modified by the
removal credit. The Industrial Users shall indicate what additional
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 Sec. Sec. 403.8 and 403.9 in a timely manner, not to exceed the time
limitation set
[[Page 24]]
forth in a compliance schedule for development of a pretreatment program
included in the POTW's NPDES permit, but in no 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
(iii) 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)(1) 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 Sec.
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--(1) Who must apply. Any POTW that wants to
give a removal credit must apply for authorization from the Approval
Authority.
(2) To whom application is 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) of this section.
(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.
[[Page 25]]
(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 and 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 Sec. 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
authorization. (i) Once a POTW has received authorization to grant
removal credits for a particular pollutant regulated in a categorical
Pretreatment 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 paragraph (a)(3)(iv) of this section
or its NPDES permit limits and conditions as required by paragraph
(a)(3)(v) of this section. If a POTW elects at a later time to extend
removal credits to a certain categorical Pretreatment 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 removal
credits shall be included in the POTW's NPDES Permit as soon 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 paragraph (f)(4) of this section.
(3) Compliance 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) Notice of
POTW. The Approval Authority shall notify the POTW if, on the basis of
pollutant removal capability reports received pursuant to paragraph
(f)(3) of this section or other relevant information available to it,
the Approval Authority determines:
(A) That one or more of the discharge limit revisions made by the
POTW, of the POTW itself, no longer meets the requirements of this
section, or
(B) That such discharge limit revisions are causing a violation of
any conditions or limits contained in the POTW's NPDES Permit.
(ii) Corrective action. If appropriate corrective action is not
taken within a reasonable time, not to exceed 60 days unless the POTW or
the affected Industrial Users demonstrate that a longer time period is
reasonably necessary to undertake the appropriate corrective action, the
Approval Authority shall either withdraw such discharge limits or
require modifications in the revised discharge limits.
(iii) Public notice of withdrawal or modification. The Approval
Authority shall not withdraw or modify revised discharge limits unless
it shall first have notified the POTW and all Industrial Users to whom
revised discharge limits have been applied, and made public, in writing,
the reasons for such
[[Page 26]]
withdrawal or modification, and an opportunity is provided for a
hearing. Following such notice and withdrawal or modification, all
Industrial Users to whom revised discharge limits had been applied,
shall be subject to the modified discharge limits or the discharge
limits prescribed in the applicable categorical Pretreatment Standards,
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 Standard(s) as may be specified by
the Approval Authority.
(g) Removal credits in State-run pretreatment programs under Sec.
403.10(e). Where an NPDES State with an approved pretreatment program
elects to implement a local pretreatment program in lieu or requiring
the POTW to develop such a program (as provided in Sec. 403.10(e)), the
POTW will not be required to develop a pretreatment program as a
precondition to obtaining authorization to give removal credits. The
POTW will, however, be required to comply with the other conditions of
paragraph (a)(3) of this section.
(h) Compensation for overflow. ``Overflow'' means the intentional or
unintentional diversion of flow from the POTW before the POTW Treatment
Plant. POTWs which at least once annually Overflow untreated wastewater
to receiving waters may claim Consistent Removal of a pollutant only by
complying with either paragraphs (h)(1) or (h)(2) of this section.
However, paragraph (h) of this section shall not apply where Industrial
User(s) can demonstrate that Overflow does not occur between the
Industrial User(s) and the POTW Treatment Plant;
(1) The Industrial User provides containment or otherwise ceases or
reduces Discharges from the regulated processes which contain the
pollutant for which an allowance is requested during all circumstances
in which an Overflow event can reasonably be expected to occur at the
POTW or at a sewer to which the Industrial User is connected. Discharges
must cease or be reduced, or pretreatment must be increased, to the
extent necessary to compensate for the removal not being provided by the
POTW. Allowances under this provision will only be granted where the
POTW submits to the Approval Authority evidence that:
(i) All Industrial Users to which the POTW proposes to apply this
provision have demonstrated the ability to contain or otherwise cease or
reduce, during circumstances in which an Overflow event can reasonably
be expected to occur, Discharges from the regulated processes which
contain pollutants for which an allowance is requested;
(ii) The POTW has identified circumstances in which an Overflow
event can reasonably be expected to occur, and has a notification or
other viable plan to insure that Industrial Users will learn of an
impending Overflow in sufficient time to contain, cease or reduce
Discharging to prevent untreated Overflows from occurring. The POTW must
also demonstrate that it will monitor and verify the data required in
paragraph (h)(1)(iii) of this section, to insure that Industrial Users
are containing, ceasing or reducing operations during POTW System
Overflow; and
(iii) All Industrial Users to which the POTW proposes to apply this
provision have demonstrated the ability and commitment to collect and
make available, upon request by the POTW, State Director or EPA Regional
Administrator, daily flow reports or other data sufficient to
demonstrate that all Discharges from regulated processes containing the
pollutant for which the allowance is requested were contained, reduced
or otherwise ceased, as appropriate, during all circumstances in which
an Overflow event was reasonably expected to occur; or
(2)(i) The Consistent Removal claimed is reduced pursuant to the
following equation:
[GRAPHIC] [TIFF OMITTED] TR14OC05.000
Where:
rm = POTW's Consistent Removal rate for that pollutant as
established under paragraphs (a)(1) and (b)(2) of this section
rc = removal corrected by the Overflow factor
Z = hours per year that Overflows occurred between the Industrial
User(s) and the POTW Treatment
[[Page 27]]
Plant, the hours either to be shown in the POTW's current NPDES permit
application or the hours, as demonstrated by verifiable techniques, that
a particular Industrial User's Discharge Overflows between the
Industrial User and the POTW Treatment Plant; and
(ii) The POTW is complying with all NPDES permit requirements and
any additional requirements in any order or decree, issued pursuant to
the Clean Water Act affecting combined sewer overflows. These
requirements include, but are not limited to, any combined sewer
overflow requirements that conform to the Combined Sewer Overflow
Control Policy.
[49 FR 31221, Aug. 3, 1984, as amended at 51 FR 20430, June 4, 1986; 53
FR 42435, Nov. 5, 1987; 58 FR 9386, Feb. 19, 1993; 58 FR 18017, Apr. 7,
1993; 70 FR 60193, Oct. 14, 2005]