Pretreatment Standards and Requirements-Categorical Pretreatment Standards
Pretreatment standards are pollutant discharge limits which apply to industrial users (IUA source of indirect discharge. [40 CFR 403.3(j)]s). Pretreatment requirements are substantive or procedural requirements applied to IUs.
Effluent limitations guidelines and pretreatment standards, also called effluent guidelines (“ELGs”), are uniform national standards developed by EPA for specific industrial categories. EPA bases these standards on the greatest pollutant reductions economically achievable for each industry. ELGs cover specific industrial processes and limit specific pollutants.
The standards applicable to indirect dischargers (also called categorical pretreatment standardsStandards specifying the quantity, concentration, or pollutant properties of pollutants that may be discharged to POTWs. EPA promulgates pretreatment standards for specific industry categories in accordance with CWA section 307. These standards are codified in 40 CFR chapter I, subchapter N, Parts 405–471. [paraphrased from 40 CFR 403.6]) are listed under each ELG as pretreatment standards for existing sourcesCategorical standards and requirements applicable to industrial sources that began construction before the publication of the proposed pretreatment standards for that industrial category (see individual standards at 40 CFR Parts 405–471) or on a date specifically provided in promulgation of the pretreatment standard. (PSES) and pretreatment standards for new sourcesCategorical standards and requirements applicable to industrial sources that began construction after the publication of the proposed pretreatment standards for that industrial category (see individual standards at 40 CFR Parts 405–471) or on a date specifically provided in promulgation of the pretreatment standard. (PSNS). Not all ELGs contain PSES and PSNS; EPA implements PSES and PSNS for 35 (out of 58) industrial categories.
These technology-based standards apply regardless of whether or not the publicly owned treatment works (POTW) has an approved pretreatment program or whether or not the nondomestic discharger has been issued a control mechanism or permit. Nondomestic dischargers subject to categorical pretreatment standards are categorical industrial users (CIUs).
Title 40 of the CFR contains regulations for all ELGs:
Learn more about variances from pretreatment standards and limits. Under certain circumstances, the control authority might grant variances to IUs from individual pretreatment standards.