Users must comply with the categorical pretreatment standards found at 40 C.F.R. Chapter I, Subchapter N, Parts 405-471.
(A) Where a categorical pretreatment standard is expressed only in terms of either the mass or the concentration of a pollutant in wastewater, the Superintendent may impose equivalent concentration or mass limits in accordance with divisions (E) and (F) of this section. Note: See 40 C.F.R. 403.6(c).
(B) When the limits in a categorical pretreatment standard are expressed only in terms of mass of pollutant per unit of production, the Superintendent 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 individual industrial users.
(C) When wastewater subject to a categorical pretreatment standard is mixed with wastewater not regulated by the standard, the Superintendent shall impose an alternate limit in accordance with 40 C.F.R. 403.6(e).
(D) A CIU may obtain a net/gross adjustment to a categorical pretreatment standard in accordance with the following divisions of this section. Note: See 40 C.F.R. 403.15.
(1) Categorical pretreatment standards may be adjusted to reflect the presence of pollutants in the industrial user’s intake water in accordance with this section. Any industrial user wishing to obtain credit for intake pollutants must make application to the city. Upon request of the industrial user, the applicable standard will be calculated on a “net” basis (i.e., adjusted to reflect credit for pollutants in the intake water) if the requirements of division (D)(2) of this section are met.
(2) Criteria.
(a) Either the applicable categorical pretreatment standards contained in 40 C.F.R. Subchapter N specifically provide that they shall be applied on a net basis; or the industrial user demonstrates that the control system it proposes or uses to meet applicable categorical pretreatment standards would, if properly installed and operated, meet the standards in the absence of pollutants in the intake waters.
(b) Credit for generic pollutants such as biochemical oxygen demand (BOD), total suspended solids (TSS), and oil and grease should not be granted unless the industrial user demonstrates that the constituents of the generic measure in the user’s effluent are substantially similar to the constituents of the generic measure in the intake water or unless appropriate additional limits are placed on process water pollutants either at the outfall or elsewhere.
(c) Credit shall be granted only to the extent necessary to meet the applicable categorical pretreatment standard(s), up to a maximum value equal to the influent value. Additional monitoring may be necessary to determine eligibility for credits and compliance with standard(s) adjusted under this section.
(d) Credit shall be granted only if the user demonstrates that the intake water is drawn from the same body of water as that into which the POTW discharges. The city may waive this requirement if it finds that no environmental degradation will result.
(E) (1) When a categorical pretreatment standard is expressed only in terms of pollutant concentrations, an industrial user may request that the city convert the limits to equivalent mass limits. The determination to convert concentration limits to mass limits is within the discretion of the Superintendent. The city may establish equivalent mass limits only if the industrial user meets all the conditions set forth in (2)(a) through (e) below.
(2) To be eligible for equivalent mass limits, the industrial user must:
(a) Employ, or demonstrate that it will employ, water conservation methods and technologies that substantially reduce water use during the term of its individual wastewater discharge permit;
(b) Currently use control and treatment technologies adequate to achieve compliance with the applicable categorical pretreatment standard, and not have used dilution as a substitute for treatment; and
(c) Provide sufficient information to establish the facility’s actual average daily flow rate for all wastestreams, based on data from a continuous effluent flow monitoring device, as well as the facility’s long-term average production rate must be representative of current operating conditions.
(Ord. 2158, passed 1-26-2009)