Wisconsin Administrative Code › Department of Natural Resources › NR 200-299 - Environmental Protection - Wisconsin Pollutant Discharge Elimination System › Chapter NR 211 - General Pretreatment Requirements › Subchapter I - Industrial User Requirements › Section NR 211.12 - Combined wastestreams

Current through June 24, 2024
(1) Where effluent from a process regulated
				  by a categorical pretreatment standard is mixed prior to treatment with
				  wastewaters other than those generated by the regulated process, fixed
				  alternative discharge limits may be established by the control authority or by
				  the industrial user with the written concurrence of the control authority.
				  These alternative limits shall apply 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
				  values specified in the appropriate categorical pretreatment standards and an
				  alternative monthly average value using the monthly average values specified in
				  the appropriate categorical pretreatment standards. The industrial user shall
				  comply with the alternative daily maximum and monthly average limits approved
				  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 shall immediately report any such material or significant
				  change to the control authority. New alternative categorical limits shall be
				  calculated within 30 days.
(2)
				  ALTERNATIVE LIMIT CALCULATION. Alternative limits shall be derived according to
				  the following formulas:
(a) Alternative
				  concentration limit: -
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(b) Alternative mass limit: -
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(c) Where:
N = The total number of regulated streams
CT = The alternative concentration
					 limit for the combined wastestream
Ci = The categorical pretreatment
					 standard concentration limit for the pollutant in the regulated stream
					 i.
MT = The alternative mass limit for
					 the combined waste-stream
Mi = The categorical pretreatment
					 standard mass limit for a pollutant in the regulated stream i, which is the
					 categorical pretreatment standard multiplied by the appropriate measure of
					 production
Fi = The average daily flow over at
					 least 30 days of stream i to the extent that it is regulated for the
					 pollutant
FT = The average daily flow over at
					 least 30 days through the combined treatment facility, including Fi, FD, and
					 unregulated streams
FD = The average daily flow over at
					 least 30 days from:
1. Boiler
				  blowdown, non-contact cooling, stormwater and demineralizer backwash streams.
				  However, if these streams contain a significant amount of a pollutant and if
				  the combination of these streams with an industrial user's regulated process
				  waste-stream prior to treatment will result in a substantial reduction of that
				  pollutant, the control authority, upon the industrial user's application, shall
				  determine whether these streams should be classified as diluted or unregulated.
				  In its application to the control authority, the industrial user shall provide
				  engineering, production, sampling and analysis and other information necessary
				  for the control authority to make its determinations;
2. Sanitary wastestreams where the streams
				  are not regulated by a categorical pretreatment standard; or
3. Any process wastestreams which were or
				  could have been entirely exempted from categorical pretreatment standards for
				  one or more of the following reasons:
a. The
				  pollutants regulated by the categorical pretreatment standards used in the
				  formula are not detectable in the effluent from the industrial user;
b. The pollutants of concern are present only
				  in trace amounts and are neither causing nor likely to cause toxic
				  effects;
c. The pollutants of
				  concern are present in amounts too small to be effectively reduced by
				  technologies known to the administrator of EPA; or
d. The wastestream contains only pollutants
				  that are compatible with the POTW.