[Code of Federal Regulations]
[Title 40, Volume 25]
[Revised as of July 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR403.6]

[Page 14-18]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 403--GENERAL PRETREAT- MENT REGULATIONS FOR EXISTING AND NEW SOURCES OF POLLUTION--Table of Contents
 
Sec. 403.6  National pretreatment standards: Categorical standards.

    National pretreatment standards specifying quantities or 
concentrations of pollutants or pollutant properties which may be 
discharged to a POTW by existing or new industrial users in specific 
industrial subcategories will be established as separate regulations 
under the appropriate subpart of 40 CFR chapter I, subchapter N. These 
standards, unless specifically noted otherwise, shall be in addition to 
all applicable pretreatment standards and requirements set forth in this 
part.
    (a) Category Determination Request--(1) Application Deadline. Within 
60 days after the effective date of a Pretreatment Standard for a 
subcategory under which an Industrial User may be included, the 
Industrial User or POTW may request that the Water Management Division 
Director or Director, as appropriate, provide written certification on 
whether the Industrial User falls within that particular subcategory. If 
an existing Industrial User adds or changes a process or operation which 
may be included in a subcategory, the existing Industrial

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User must request this certification prior to commencing discharge from 
the added or changed processes or operation. A New Source must request 
this certification prior to commencing discharge. Where a request for 
certification is submitted by a POTW, the POTW shall notify any affected 
Industrial User of such submission. The Industrial User may provide 
written comments on the POTW submission to the Water Management Division 
Director or Director, as appropriate, within 30 days of notification.
    (2) Contents of Application. Each request shall contain a statement:
    (i) Describing which subcategories might be applicable; and
    (ii) Citing evidence and reasons why a particular subcategory is 
applicable and why others are not applicable. Any person signing the 
application statement submitted pursuant to this section shall make the 
following certification:

    I certify under penalty of law that this document and all 
attachments were prepared under my direction or supervision in 
accordance with a system designed to assure that qualified personnel 
properly gather and evaluate the information submitted. Based on my 
inquiry of the person or persons who manage the system, or those persons 
directly responsible for gathering the information, the information 
submitted is, to the best of my knowledge and belief, true, accurate, 
and complete. I am aware that there are significant penalties for 
submitting false information, including the possibility of fine and 
imprisonment for knowing violations.

    (3) Deficient requests. The Water Management Division Director or 
Director will only act on written requests for determinations that 
contain all of the information required. Persons who have made 
incomplete submissions will be notified by the Water Management Division 
Director or Director that their requests are deficient and, unless the 
time period is extended, will be given 30 days to correct the 
deficiency. If the deficiency is not corrected within 30 days or within 
an extended period allowed by the Water Management Division Director or 
the Director, the request for a determination shall be denied.
    (4) Final decision. (i) When the Water Management Division Director 
or Director receives a submittal he or she will, after determining that 
it contains all of the information required by paragraph (2) of this 
section, consider the submission, any additional evidence that may have 
been requested, and any other available information relevant to the 
request. The Water Management Division Director or Director will then 
make a written determination of the applicable subcategory and state the 
reasons for the determination.
    (ii) Where the request is submitted to the Director, the Director 
shall forward the determination described in this paragraph to the Water 
Management Division Director who may make a final determination. The 
Water Management Division Director may waive receipt of these 
determinations. If the Water Management Division Director does not 
modify the Director's decision within 60 days after receipt thereof, or 
if the Water Management Division Director waives receipt of the 
determination, the Director's decision is final.
    (iii) Where the request is submitted by the Industrial User or POTW 
to the Water Management Division Director or where the Water Management 
Division Director elects to modify the Director's decision, the Water 
Management Division Director's decision will be final.
    (iv) The Water Management Division Director or Director, as 
appropriate, shall send a copy of the determination to the affected 
Industrial User and the POTW. Where the final determination is made by 
the Water Management Division Director, he or she shall send a copy of 
the determination to the Director.
    (5) Requests for hearing and/or legal decision. Within 30 days 
following the date of receipt of notice of the final determination as 
provided for by paragraph (a)(4)(iv) of this section, the Requester may 
submit a petition to reconsider or contest the decision to the Regional 
Administrator who shall act on such petition expeditiously and state the 
reasons for his or her determination in writing.
    (b) Deadline for Compliance with Categorical Standards. Compliance 
by existing sources with categorical Pretreatment Standards shall be 
within 3 years of the date the Standard is effective unless a shorter 
compliance

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time is specified in the appropriate subpart of 40 CFR chapter I, 
subchapter N. Direct dischargers with NPDES permits modified or reissued 
to provide a variance pursuant to section 301(i)(2) of the Act shall be 
required to meet compliance dates set in any applicable categorical 
Pretreatment Standard. Existing sources which become Industrial Users 
subsequent to promulgation of an applicable categorical Pretreatment 
Standard shall be considered existing Industrial Users except where such 
sources meet the definition of a New Source as defined in Sec. 403.3(k). 
New Sources shall install and have in operating condition, and shall 
``start-up'' all pollution control equipment required to meet applicable 
Pretreatment Standards before beginning to Discharge. Within the 
shortest feasible time (not to exceed 90 days), New Sources must meet 
all applicable Pretreatment Standards.
    (c)(1) Concentration and mass limits. Pollutant discharge limits in 
categorical Pretreatment Standards will be expressed either as 
concentration or mass limits. Wherever possible, where concentration 
limits are specified in standards, equivalent mass limits will be 
provided so that local, State or Federal authorities responsible for 
enforcement may use either concentration or mass limits. Limits in 
categorical Pretreatment Standards shall apply to the effluent of the 
process regulated by the Standard, or as otherwise specified by the 
standard.
    (2) When the limits in a categorical Pretreatment Standard are 
expressed only in terms of mass of pollutant per unit of production, the 
Control Authority may convert the limits to equivalent limitations 
expressed either as mass of pollutant discharged per day of effluent 
concentration for purposes of calculating effluent limitations 
applicable to individual Industrial Users.
    (3) A Control Authority calculating equivalent mass-per-day 
limitations under paragraph (c)(2) of this section shall calculate such 
limitations by multiplying the limits in the Standard by the Industrial 
User's average rate of production. This average rate of production shall 
be based not upon the designed production capacity but rather upon a 
reasonable measure of the Industrial User's actual long-term daily 
production, such as the average daily production during a representative 
year. For new sources, actual production shall be estimated using 
projected production.
    (4) A Control Authority calculating equivalent concentration 
limitations under paragraph (c)(2) of this section shall calculate such 
limitations by dividing the mass limitations derived under paragraph 
(c)(3) of this section by the average daily flow rate of the Industrial 
User's regulated process wastewater. This average daily flow rate shall 
be based upon a reasonable measure of the Industrial User's actual long-
term average flow rate, such as the average daily flow rate during the 
representative year.
    (5) Equivalent limitations calculated in accordance with paragraphs 
(c)(3) and (c)(4) of this section shall be deemed Pretreatment Standards 
for the purposes of section 307(d) of the Act and this part. Industrial 
Users will be required to comply with the equivalent limitations in lieu 
of the promulgated categorical standards from which the equivalent 
limitations were derived.
    (6) Many categorical pretreatment standards specify one limit for 
calculating maximum daily discharge limitations and a second limit for 
calculating maximum monthly average, or 4-day average, limitations. 
Where such Standards are being applied, the same production of flow 
figure shall be used in calculating both types of equivalent 
limitations.
    (7) Any Industrial User operating under a control mechanism 
incorporating equivalent mass or concentration limits calculated from a 
production based standard shall notify the Control Authority within two 
(2) business days after the User has a reasonable basis to know that the 
production level will significantly change within the next calendar 
month. Any User not notifying the Control Authority of such anticipated 
change will be required to meet the mass or concentration limits in its 
control mechanism that were based on the original estimate of the long 
term average production rate.

[[Page 17]]

    (d) Dilution Prohibited as Substitute for Treatment. Except where 
expressly authorized to do so by an applicable Pretreatment Standard or 
Requirement, no Industrial User shall ever increase the use of process 
water, or in any other way attempt to dilute a discharge as a partial or 
complete substitute for adequate treatment to achieve compliance with a 
Pretreatment Standard or Requirement. The Control Authority (as defined 
in Sec. 403.12(a)) may impose mass limitations on Industrial Users which 
are using dilution to meet applicable Pretreatment Standards or 
Requirements, or in other cases where the imposition of mass limitations 
is appropriate.
    (e) Combined wastestream formula. Where process effluent is mixed 
prior to treatment with wastewaters other than those generated by the 
regulated process, fixed alternative discharge limits may be derived by 
the Control Authority, as defined in Sec. 403.12(a), or by the 
Industrial User with the written concurrence of the Control Authority. 
These alternative limits shall be applied to the mixed effluent. When 
deriving alternative categorical limits, the Control Authority or 
Industrial User shall calculate both an alternative daily maximum value 
using the daily maximum value(s) specified in the appropriate 
categorical Pretreatment Standard(s) and an alternative consecutive 
sampling day average value using the monthly average value(s) specified 
in the appropriate categorical Pretreatment Standard(s). The Industrial 
User shall comply with the alternative daily maximum and monthly average 
limits fixed by the Control Authority until the Control Authority 
modifies the limits or approves an Industrial User modification request. 
Modification is authorized whenever there is a material or significant 
change in the values used in the calculation to fix alternative limits 
for the regulated pollutant. An Industrial User must immediately report 
any such material or significant change to the Control Authority. Where 
appropriate new alternative categorical limits shall be calculated 
within 30 days.
    (1) Alternative limit calculation. For purposes of these formulas, 
the ``average daily flow'' means a reasonable measure of the average 
daily flow for a 30-day period. For new sources, flows shall be 
estimated using projected values. The alternative limit for a specified 
pollutant will be derived by the use of either of the following 
formulas:
    (i) Alternative concentration limit.
    [GRAPHIC] [TIFF OMITTED] TC15NO91.012
    
where

CT=the alternative concentration limit for the combined 
wastestream.
Ci=the categorical Pretreatment Standard concentration limit 
for a pollutant in the regulated stream i.
Fi=the average daily flow (at least a 30-day average) of 
stream i to the extent that it is regulated for such pollutant.
FD=the average daily flow (at least a 30-day average) from: 
(a) Boiler blowdown streams, non-contact cooling streams, stormwater 
streams, and demineralizer backwash streams; provided, however, that 
where such streams contain a significant amount of a pollutant, and the 
combination of such streams, prior to treatment, with an Industrial 
User's regulated process wastestream(s) will result in a substantial 
reduction of that pollutant, the Control Authority, upon application of 
the Industrial User, may exercise its discretion to determine whether 
such stream(s) should be classified as diluted or unregulated. In its 
application to the Control Authority, the Industrial User must provide 
engineering, production, sampling and analysis and such other 
information so that the Control Authority can make its determination; or 
(b) sanitary wastestreams where such streams are not regulated by a 
Categorical Pretreatment Standard; or (c) from any process wastestreams 
which were or could have been entirely exempted from categorical 
Pretreatment Standards pursuant to paragraph 8 of the NRDC v. Costle 
Consent Decree (12 ERC 1833) for one or more of the following reasons 
(see appendix D of this part):
    (1) The pollutants of concern are not detectable in the effluent 
from the Industrial User (paragraph (8)(a)(iii));
    (2) The pollutants of concern are present only in trace amounts and 
are neither causing nor likely to cause toxic effects (paragraph 
(8)(a)(iii));
    (3) The pollutants of concern are present in amounts too small to be 
effectively reduced

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by technologies known to the Administrator (paragraph (8)(a)(iii)); or
    (4) The wastestream contains only pollutants which are compatible 
with the POTW (paragraph (8)(b)(i)).
FT=The average daily flow (at least a 30-day average) through 
the combined treatment facility (includes Fi, FD 
and unregulated streams).
N=The total number of regulated streams.

    (ii) Alternative mass limit.
    [GRAPHIC] [TIFF OMITTED] TC15NO91.013
    
where

MT=the alternative mass limit for a pollutant in the combined 
wastestream.
Mi=the categorical Pretreatment Standard mass limit for a 
pollutant in the regulated stream i (the categorical pretreatment mass 
limit multiplied by the appropriate measure of production).
Fi=the average flow (at least a 30-day average) of stream i 
to the extent that it is regulated for such pollutant.
FD=the average daily flow (at least a 30-day average) from: 
(a) Boiler blowdown streams, non-contact cooling streams, stormwater 
streams, and demineralizer backwash streams; provided, however, that 
where such streams contain a significant amount of a pollutant, and the 
combination of such streams, prior to treatment, with an Industrial 
User's regulated process wastestream(s) will result in a substantial 
reduction of that pollutant, the Control Authority, upon application of 
the Industrial User, may exercise its discretion to determine whether 
such stream(s) should be classified as diluted or unregulated. In its 
application to the Control Authority, the Industrial User must provide 
engineering, production, sampling and analysis and such other 
information so that the Control Authority can make its determination; or 
(b) sanitary wastestreams where such streams are not regulated by a 
categorical Pretreatment Standard; or (c) from any process wastestreams 
which were or could have been entirely exempted from categorical 
Pretreatment Standards pursuant to paragraph 8 of the NRDC v. Costle 
Consent Decree (12 ERC 1833) for one or more of the following reasons 
(see appendix D of this part):
    (1) The pollutants of concern are not detectable in the effluent 
from the Industrial User (paragraph (8)(a)(iii));
    (2) The pollutants of concern are present only in trace amounts and 
are neither causing nor likely to cause toxic effects (paragraph 
(8)(a)(iii));
    (3) The pollutants of concern are present in amounts too small to be 
effectively reduced by technologies known to the Administrator 
(paragraph (8)(a)(iii)); or
    (4) The wastestream contains only pollutants which are compatible 
with the POTW (paragraph (8)(b)(i)).
FT=The average flow (at least a 30-day average) through the 
combined treatment facility (includes Fi, FD and 
unregulated streams).
N=The total number of regulated streams.

    (2) Alternate limits below detection limit. An alternative 
pretreatment limit may not be used if the alternative limit is below the 
analytical detection limit for any of the regulated pollutants.
    (3) Self-monitoring. Self-monitoring required to insure compliance 
with the alternative categorical limit shall be conducted in accordance 
with the requirements of Sec. 403.12(g).
    (4) Choice of monitoring location. Where a treated regulated process 
wastestream is combined prior to treatment with wastewaters other than 
those generated by the regulated process, the Industrial User may 
monitor either the segregated process wastestream or the combined 
wastestream for the purpose of determining compliance with applicable 
Pretreatment Standards. If the Industrial User chooses to monitor the 
segregated process wastestream, it shall apply the applicable 
categorical Pretreatment Standard. If the User chooses to monitor the 
combined wastestream, it shall apply an alternative discharge limit 
calculated using the combined wastestream formula as provided in this 
section. The Industrial User may change monitoring points only after 
receiving approval from the Control Authority. The Control Authority 
shall ensure that any change in an Industrial User's monitoring point(s) 
will not allow the User to substitute dilution for adequate treatment to 
achieve compliance with applicable Standards.

[46 FR 9439, Jan. 28, 1981, as amended at 49 FR 21037, May 17, 1984; 49 
FR 31224, Aug. 3, 1984; 51 FR 20430, June 4, 1986; 51 FR 23760, July 1, 
1986; 53 FR 40610, Oct. 17, 1988; 55 FR 30129, July 24, 1990; 58 FR 
18017, Apr. 7, 1993]

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