(A) Upon the promulgation of the Federal Categorical Pretreatment Standard or a particular industrial subcategory, the Federal Standard, if more stringent than limitations imposed under this chapter for sources in that subcategory, shall immediately supersede the limitations imposed under this chapter. The Superintendent shall notify all affected users of the applicable reporting requirement under 40 CFR, Section 403.12.
(1) 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. The user shall comply with the equivalent limits. In addition to the other information required in the users semi-annual reports to the Control Authority, a user subject to categorical standards expressed only in terms of allowable pollutant discharge per unit of production (or other measure of operation) must include the user's actual average production rate for the reporting period.
(2) 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 40 CFR 403.12(a), or by the industrial user with the written concurrence of the Control Authority. These alterative 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 limit 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 of 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.
(B) Where the Control Authority's wastewater treatment system achieves consistent removal of pollutants limited by Federal Pretreatment Standards, the Superintendent may apply to the Approval Authority for modification of specific limits in the Federal Pretreatment Standards.
CONSISTENT REMOVAL shall mean reduction in the amount of pollutant or alteration of the nature of the pollutant by the wastewater treatment system to a less toxic or harmless state in the effluent which is achieved by the system in 95% of the samples taken when measured according to the procedures set forth in Section 403.7(c)(2) of Title 40 of the Code of Federal Regulations, Part 403, "General Pretreatment Regulations for Existing and New Sources of Pollution" promulgated Federal Pretreatment Standards if the requirements contained in 40 CFR, Part 403, Section 403.7 are fulfilled and prior approval from the approval authority is obtained.
(Ord. passed - -91)