2.4 National Categorical Pretreatment Standards

The categorical pretreatment standards found at 40 CFR Chapter I, Subchapter N, Parts 405 - 471 are hereby incorporated.

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 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 Superintendent shall impose an alternate limit using the combined waste stream formula in 40 CFR 403.6 (e).

C. A user may obtain a variance from a categorical pretreatment standard if the user can prove, pursuant to the procedural and substantive provisions in 40 CFR 403.12, that factors relating to its discharge are fundamentally different from the factors considered by EPA when developing the categorical pretreatment standard.

D. A user may obtain a net gross adjustment to a categorical standard in according with 40 CFR 403.15.