Effluent Guidelines

Aluminum Forming Effluent Guidelines

""EPA promulgated the Aluminum Forming Effluent Guidelines and Standards (40 CFR Part 467) in 1983 and amended the regulation in 1988. The regulation covers direct and indirect dischagers. The Effluent Guidelines and Standards are incorporated into NPDES permits for direct dischargersHelpdirect dischargerA point source that discharges pollutants to waters of the United States, such as streams, lakes, or oceans., and permits or other control mechanisms for indirect dischargersHelpindirect dischargerA facility that discharges pollutants to a publicly owned treatment works (municipal sewage treatment plant). (see Pretreatment Program).

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What is the Aluminum Forming Industry?

Aluminum forming is the deformation of aluminum or alloys into specific shapes by hot or cold working such as rolling, extrusion, forging, and drawing. Also included are a number of ancillary operations such as casting, heat treatment, and surface treatment that are an integral part of aluminum forming processes and that can contribute significantly to the wastewater discharged from aluminum forming plants.

Products manufactured by aluminum forming operations generally serve as stock for subsequent fabricating operations.
  • Cast ingots and billets are the starting point for making sheet and plate, extrusions, and forgings, as well as rod and wire.
  • Rolled aluminum sheet and plate can be used as stock for stampings, can blanks, and roll formed products; as finished products in building, ship and aircraft construction; or as foil.
  • Extrusions can be used as raw stock for forging and drawing; to fabricate final products, such as bumpers, window frames, or light standards; or can be sold as final products, such as beams or extruded tubing.
  • Forgings are either sold as consumer products or used as parts in the production of machinery, aircraft, and engines.
Diagram of Aluminum Forming industry processes and products: tube, rod, bar, fire, forgings, plate, sheet, foil
Aluminum forming activities are included within the following NAICS groups:
  • 331315: Aluminum Sheet, Plate, and Foil Manufacturing
  • 331316: Aluminum Extruded Product Manufacturing
  • 331319: Other Aluminum Rolling and Drawing
  • 332112: Nonferrous Forging
Note: the NAICS listing is provided as a guide and does not define the coverage of the Aluminum Forming Category. For precise definitions of coverage, see the applicability sections in 40 CFR Part 467.

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Facilities Covered

The Aluminum Forming regulation is organized into six subcategories. Each subcategory consists of core and ancillary operations. The core operations include the forming operation along with processes that are either closely linked with that forming operation or generate very little or no wastewater. Some plants are covered by more than one subcategory.

  1. Rolling With Neat Oils
  2. Rolling With Emulsions
  3. Extrusion
  1. Forging
  2. Drawing With Neat Oils
  3. Drawing With Emulsions or Soaps
Unit Operations and Wastestreams*
Unit Operation Wastestream
Annealing Atmosphere scrubber liquor
Artificial aging (Dry operation)
Cleaning, etching, or other surface treatment Bath: caustic, acid, seal, or detergent solutions; rinse water; scrubber liquor
Cold rolling Spent neat oil or emulsion
Continuous rod casting Spent lubricant, contact cooling water
Continuous sheet casting Spent lubricant
Degassing Scrubber liquor
Direct chill casting Contact cooling water
Drawing Spent neat oil, emulsion, or soap solution
Extrusion die cleaning Bath caustic solution, rinse water, scrubber liquor
Extrusion dummy block cooling Contact cooling water
Forging Scrubber liquor
Homogenizing (Dry operation)
Hot rolling Spent emulsion
Press heat treatment Contact cooling water
Roll grinding Spent emulsion
Sawing Spent neat oil or emulsion
Solution heat treatment Contact cooling water
Solvent degreasing Spent solvents
Stationary casting (Dry operation)
Swaging (Dry operation)

* For the complete list of processes and wastestreams see the regulation at 40 CFR Part 467

Surface Treatment

For the purposes of this regulation, surface treatment is considered to be a part of the Aluminum Forming Category whenever it is performed as an integral part of aluminum forming. All surface treatment of aluminum is considered to be an integral part of Aluminum Forming whenever it is performed at the same plant site at which aluminum is formed, and such operations are not considered for regulation under the Electroplating (40 CFR Part 413) or Metal Finishing (40 CFR Part 433) categories.


Casting done at a plant which manufactures aluminum and also does aluminum forming is subject to the casting limitations for the aluminum manufacturing subcategories of the Nonferrous Metals Manufacturing Category (40 CFR Part 421), if there is no cooling of the aluminum prior to casting. If the aluminum is a remelted primary aluminum product and is cast at a facility for subsequent forming of aluminum, then the casting of remelted aluminum is subject to the Aluminum Forming Category limitations.

Other Related Categories

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Guidance Documents

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Rulemaking History

1988 Amendment

Promulgated pursuant to litigation
  • Documents, including:
    • Final rule (December 27, 1988)
    • Proposed rule (March 19, 1986)

1983 Initial Rulemaking

  • Documents, including:
    • Final rule (October 24, 1983)
    • Development Document (June 1984)
      Industry description, wastewater characterization, treatment technologies, regulatory compliance cost estimates and pollutant loadings for the final rule
    • Proposed rule (November 22, 1982)

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Additional Information

For additional information regarding Aluminum Forming Effluent Guidelines, please contact Samantha Lewis, lewis.samantha@epa.gov or 202-566-1058.