NR 211.12(2)(c)1.1. 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;

NR 211.12(2)(c)2.2. Sanitary wastestreams where the streams are not regulated by a categorical pretreatment standard; or

NR 211.12(2)(c)3.3. Any process wastestreams which were or could have been entirely exempted from categorical pretreatment standards for one or more of the following reasons:

NR 211.12(2)(c)3.a.a. The pollutants regulated by the categorical pretreatment standards used in the formula are not detectable in the effluent from the industrial user;

NR 211.12(2)(c)3.c.c. The pollutants of concern are present in amounts too small to be effectively reduced by technologies known to the administrator of EPA; or

NR 211.12(3)(3) 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.

NR 211.12(4)(4) Self-monitoring. Self-monitoring to insure compliance with the alternative categorical limit shall be conducted in accordance with s. NR 211.15 (4).

NR 211.12(5)(a)(a) If a treated regulated process wastestream is combined 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 purposes of determining compliance with the applicable pretreatment standards. If the industrial user chooses to monitor the segregated process wastestream, the industrial user shall apply the applicable categorical pretreatment standard. If the industrial user chooses to monitor the combined wastestream, the industrial user shall apply an alternative discharge limit calculated according to the combined wastestream formula in sub. (2).

NR 211.12(5)(b)(b) An 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 will not allow the industrial user to substitute dilution for adequate treatment.

NR 211.12 HistoryHistory: Cr. Register, September, 1986, No. 369, eff. 10-1-86; am. (1), r. and recr. (2) and (4), cr. (5) and (6), Register, March, 1992, No. 435, eff. 4-1-92; CR 13-006: r. (6) Register January 2014 No. 697, eff. 2-1-14.

NR 211.13(1)(a)(a) Any POTW receiving wastes from an industrial user to which a categorical pretreatment standard applies may, subject to the conditions of this section, grant removal credits for removal by the POTW of pollutants specified in the categorical pretreatment standard. The POTW may grant a removal credit equal to or 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 par. (c).

NR 211.13(1)(b)1.1. The POTW applies for and receives authorization from the department to give a removal credit in accordance with the requirements and procedures specified in sub. (5). Removal credits may only be given for indicator or surrogate pollutants regulated in a categorical pretreatment standard if the categorical pretreatment standard so specifies.

NR 211.13(1)(b)2.2. The POTW demonstrates and continues to achieve consistent removal of the pollutant in accordance with sub. (2).

NR 211.13(1)(b)3.3. Except as provided in sub. (7), the POTW has an approved pretreatment program as required by this chapter; however, a POTW which does not have an approved pretreatment program may, pending approval of such a program, conditionally give credits as provided in sub. (4).

NR 211.13(1)(b)4.4. 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 department that even though it is not presently in compliance with applicable sludge requirements, it will be in compliance when the industrial user to whom the removal credit would apply is required to meet its modified categorical pretreatment standard.

NR 211.13(1)(b)5.5. 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 department that even though it is not presently in compliance with applicable limitations and conditions in its WPDES permit, it will be in compliance when the industrial user to whom the removal credit would apply is required to meet its modified categorical pretreatment standard.

NR 211.13(1)(b)6.6. The granting of removal credits will not result in a discharge of pollutants to waters of the state greater than the discharge that would be allowed if the pollutants were discharged other than through a POTW.

y = x
l-r
where:
x = pollutant discharge limit specified in the applicable
categorical pretreatment standard.
r = removal credit for that pollutant as established under sub. (2) (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).