Effluent Guidelines

Metal Finishing Effluent Guidelines

EPA promulgated the Metal Finishing Effluent Guidelines (40 CFR Part 433) in 1983, with technical amendments in 1984 and 1986. The regulations cover wastewater discharges from a wide variety of industries performing various metal finishing operations. About 44,000 facilities perform various metal finishing operations and discharge process wastewater directly to surface waters or indirectly to surface waters through POTWs. The Metal Finishing Effluent Guidelines are incorporated into NPDES permits for direct dischargers, and permits or other control mechanisms for indirect dischargers (see Pretreatment Program).

What is Metal Finishing?

Metal finishing is the process of changing the surface of an object, for the purpose of improving its appearance and/or durability. Metal finishing is related to electroplating, which is the production of a thin surface coating of the metal upon another by electrodeposition.

Facilities Covered

Related Information

The Metal Finishing regulation is defined by manufacturing processes and not by industrial sectors. However, facilities regulated by the Metal Finishing Effluent Guidelines are often included in the SIC Major Groups 34 through 39:

​Preliminary Category Review — 2018

EPA completed a preliminary review of the Metal Finishing category in 2018. In the review, the Agency collected data to understand the current state of the industry, including its economic condition, the wastewater pollutants discharged, and the wastewater treatment technologies and management techniques used to control these discharges, including zero discharge. Based on its observations, EPA concluded that further regulation of the Metal Finishing category is not warranted at this time. Questions about the applicability of the existing Metal Finishing Effluent Guidelines to current metal finishing operations persist and EPA will focus its efforts going forward on resolving them.