EPA Self-Audit and Inspection Guide
Organic Finishing of Metals

General Pretreatment Regulations For Existing And New Sources Of Pollution (40CFR403.1 -- 40CFR403.18)

The following is a summary of the referenced federal rules, as published in the Code of Federal Regulations (CFR). This information is provided as an aide to help understand the requirements of the federal regulations, as they pertain to specific industrial or manufacturing operations. This information is not provided nor intended to act as a substitute for legal or other professional services. CFR citation numbers for each subpart are indicated, while the full text of the CFR citations can be viewed by clicking HERE and following the directions.

Purpose and applicability (40CFR403.1)
Delineates the responsibilities of Federal, State, and local government, industry and the public to implement National Pretreatment Standards to control pollutants which are discharged to publicly owned treatment works (POTWs) or that may pass through or interfere with treatment processes or contaminate sewage sludge. This regulation applies to industrial wastewater discharges and POTWs that receive wastewater from other sources subject to the National Pretreatment Standards, but does not apply to sources that discharge to a sewer that is not connected to a POTW.

Objectives of general pretreatment regulations (40CFR403.2)
Pretreatment standards have the following objectives: (1) prevent the introduction of pollutants into POTWs that would interfere with its operation and the use or disposal of municipal sludge; (2) prevent the introduction of pollutants into POTWs that would pass through the treatment process(es) or works or otherwise be incompatible with such process(es); and, (3) enhance the opportunities to recycle and reclaim municipal and industrial wastewaters and sludges.

Definitions (40CFR403.3)
Two essential definitions, as they apply to the pretreatment standards, are:

Interference -- means a discharge which, alone or in conjunction with a discharge or discharges from other sources, both: (1) inhibits or disrupts the POTW, its treatment processes or operations, or its sludge processes, use or disposal; and, (2) therefore is a cause for a violation of any requirement of the POTW's NPDES permit (including an increase in the magnitude or duration of a violation) or prevents the use or disposal of the sewage sludge, in compliance with the applicable statutory provisions.

Pass Through -- means a discharge which exits the POTW into the waters of the United States in quantities or concentrations which, alone or in conjunction with a discharge or discharges from other sources, is a cause of a violation of any requirement of the POTW's NPDES permit (including an increase in the magnitude or duration of a violation).

(1) Pollutants that can create a fire or explosion hazard in the POTW, including, but not limited to, wastestreams with a closed cup flashpoint of less than 140o F or 60o C.
(2) Pollutants that will cause corrosive structural damage to the POTW, but in no case discharges with a pH lower than 5.0, unless the POTW is specifically designed to accommodate such discharges.
(3) Solid or viscous pollutants in amounts that will obstruct the flow in the POTW, resulting in Interference.
(4) Any pollutant, including oxygen-demanding pollutants (BOD, COD, etc.) released at a flow rate and/or concentration that will cause Interference.
(5) Heat in amounts that will inhibit biological activity in the POTW, resulting in Interference.
(6) Petroleum oil, nonbiodegradable cutting oil, or products of mineral oil origin in amounts that will cause Interference or Pass Through.
(7) Pollutants that generate toxic gases, vapors, or fumes within the POTW in a quantity that may cause acute worker health and safety problems.
(8) Any trucked or hauled pollutants, except at discharge points designated by the POTW.

Removal Credits (40CFR403.7)
Any POTW may grant credits to certain industrial facilities, thereby indicating that the POTW will be responsible for removing specific pollutants from the wastewater stream. Removal credits will only be granted to facilities that are covered by the pretreatment standards for categorical sources. The removal credit may be equal to, or less than, the consistent removal rate for the pollutant(s). Once granted, the industrial facility may then release concentrations of the particular pollutant(s) in excess of the listed pretreatment standard. To issue removal credits, the granting POTW must be able to consistently remove the pollutant(s) and have adequate processes to treat the excess waste.
 Pretreatment Program Requirements: Development and Implementation by POTW (40CFR403.8)
POTWs are responsible for having their discharges meet effluent limitations guidelines and providing treatment to all typically accepted wastewater flows. To meet these responsibilities, POTWs may further restrict pollutant levels in the inflows, randomly sample and analyze effluent from industrial users, and investigate instances of noncompliance.

Reporting requirements for POTWs and industrial users (40CFR403.12)
Dischargers subject to the pretreatement standards are required to submit reports of their operations, pollutant(s) amounts and concentrations, and flows to the POTW that receives their wastewater. Reports must be submitted regularly, so that the POTW may take actions to remedy possible problems caused by changes in the effluent flow pattern. Dischargers must maintain records with information on sample testing, test results, and analytical methods used to determine pollutant concentrations in the effluent.