Users must comply with the categorical Pretreatment Standards found at 40 CFR Chapter 1, Subchapter N, Parts 405-471. Effluent limitations promulgated by the federal act shall apply in any instance where they are more stringent than those in this chapter. The categorical pretreatment standards found at 40 CFR Chapter 1, Subchapter N, Parts 405-471 and any future promulgated regulations are hereby incorporated.
(A) Where a categorical pretreatment standard is expressed only in terms of the concentration of a pollutant in wastewater, the Board may impose equivalent mass limits in accordance with § 52.016(D) and 40 CFR 403.6(c).
(B) When wastewater subject to a categorical pretreatment standard is mixed with wastewater not regulated by the same standard, the Board shall impose an alternate limit in accordance with 40 CFR 403.6(e).
(C) A CIU may obtain a net/gross adjustment to a categorical pretreatment standard in accordance with 40 CFR 403.15.
(D) When a categorical pretreatment standard is expressed only in terms of pollutant concentrations, a CIU may request that the Board convert the limits to equivalent mass limits. The determination to convert concentration limits to mass limits is within the discretion of the Board. The Board may establish equivalent mass limits only if the CIU meets all the conditions set forth in 40 CFR 403.6(c)(5).
(E) Once included in its permit, the CIU must comply with the equivalent limitations developed in this section in lieu of the promulgated categorical standards from which the equivalent limitations were derived.
(F) Many categorical pretreatment standards specify one limit for calculating maximum daily discharge limitations and a second limit for calculating maximum monthly average, or four-day average, limitations. Where such standards are being applied, the same production or flow figure shall be used in calculating both the average and the maximum equivalent limitation.
(G) Any CIU operating under a permit incorporating equivalent mass limits calculated from a production-based standard shall notify the Board within two business days after the CIU has a reasonable basis to know that the production level will significantly change within the next calendar month. Any CIU not notifying the Board of such anticipated change will be required to meet the mass or concentration limits in its permit that were based on the original estimate of the long term average production rate.
(H) When the limits in a categorical pretreatment standard are expressed only in terms of mass of pollutant per unit of production, the Board may convert the limits to equivalent limitations expressed either as mass of pollutant discharged per day or effluent concentration for purposes of calculating effluent limitations applicable to CIUs.
(Ord. 9-2016, passed 6-7-2016)