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Effluent Guidelines

Nonferrous Metals Manufacturing Effluent Guidelines

Photo of copper refining facilityEPA promulgated the Nonferrous Metals Manufacturing (NFMM) Effluent Guidelines and Standards (40 CFR Part 421) initially in 1974-1976, and added subcategories and revised the regulations in 1980-1990 pursuant to Clean Water Act amendments and litigation. The regulations cover wastewater discharges from a wide range of metal manufacturing facilities. The NFMM 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 Nonferrous Metals Manufacturing?

Primary metals manufacturers extract metals from ores and operate smelters, which heat ore mixtures to separate liquid metal and impurities. Secondary manufacturers process recycled or scrap metals. Extraction processes include chemical addition (e.g. limestone, coke, soda ash) and treatments (e.g. solvents). Some processes involve application of electrical current (e.g., aluminum, tin). The metals may be cast into various shapes (e.g., billets, ingots, bars) prior to shipment to customers, which fabricate final products.

The wastewater streams generated by the industry vary according to the metal extraction processes employed, but generally derive from smelter furnace and filtration residues, rinsing of materials, spent solutions, equipment cooling and air pollution controls (wet scrubbers).

These activities are included within the following NAICS codes:
  • 331313: Alumina Refining and Primary Aluminum Production
  • 331314: Secondary Smelting and Alloying of Aluminum
  • 331410: Nonferrous Metal (except Aluminum) Smelting and Refining
  • 331492: Secondary Smelting, Refining, and Alloying of Nonferrous Metal (except Copper and Aluminum)

Diagram of Effluent Guidelines categories covering metals industriesMetals coverage under Effluent Guidelines
- Click to enlarge
: The NAICS group listing is provided as a guide and does not define the coverage of the NFMM regulations. For precise definitions of coverage, see the applicability sections in 40 CFR Part 421.

Note: Many post-extraction processes such as rolling, drawing, extruding and foil fabrication are covered by the Nonferrous Metals Forming and Metal Powders Category, (40 CFR Part 471), the Aluminum Forming Category (40 CFR Part 467), and the Copper Forming Category (40 CFR Part 468).

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Facilities Covered

The NFMM effluent guidelines apply to facilities in 31 subcategories:

  1. Bauxite Refining
  2. Primary Aluminum Smelting
  3. Secondary Aluminum Smelting
  4. Primary Copper Smelting
  5. Primary Electrolytic Copper Refining
  6. Secondary Copper
  7. Primary Lead
  8. Primary Zinc
  9. Metallurgical Acid Plants
  10. Primary Tungsten
  11. Primary Columbium-Tantalum
  12. Secondary Silver
  13. Secondary Lead
  14. Primary Antimony
  15. Primary Beryllium
  16. Primary and Secondary Germanium and Gallium
  1. Secondary Indium
  2. Secondary Mercury
  3. Primary Molybdenum and Rhenium
  4. Secondary Molybdenum and Vanadium
  5. Primary Nickel and Cobalt
  6. Secondary Nickel
  7. Primary Precious Metals and Mercury
  8. Secondary Precious Metals
  9. Primary Rare Earth Metals
  10. Secondary Tantalum
  11. Secondary Tin
  12. Primary and Secondary Titanium
  13. Secondary Tungsten and Cobalt
  14. Secondary Uranium
  15. Primary Zirconium and Hafnium

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Rulemaking History

1990 Amendment

BAT revisions; Subparts I, O, S, T, X, AC
  • Documents, including:
    • Final rule (August 3, 1990)
    • Development Document - Consolidation of all BAT Phase I & II revisions (May 1989)
    • Proposed rule (April 28, 1989)

1988 Amendment

Revised Subpart J
  • Documents, including:
    • Final rule (January 21, 1988)
    • Proposed rule (January 22, 1987)

1987 Amendment

Revised Subparts B, C
  • Documents, including:
    • Final rule (July 7, 1987)
    • Proposed rule (May 20, 1986)

1985 Amendment

BAT Phase II (pursuant to 1977 CWA amendments); Subparts A, I, N-AE
  • Documents, including:
    • Final rule (September 20, 1985)
    • Proposed rule (June 27, 1984)

1984 Amendment

BAT Phase I (pursuant to 1977 CWA amendments); Subparts B-M
  • Documents, including:
    • Final rule (March 8, 1984)
    • Notice of data availability (November 21, 1983)
    • Proposed rule (February 17, 1983)

1980 Amendment

Revised the February 27, 1975 rule for Subparts D, E; added Subpart I

1976 Initial Rulemaking

PSES requirements added to Subparts C, F
  • Documents, including:
    • Interim final rule (PSES, Subparts C, F) (December 15, 1976)
    • Proposed rule (NSPS, PSNS, PSES; Subparts D, E, F, G, H) (February 27, 1975)

1975 Initial Rulemaking

Established BPT, BAT requirements: Subparts D, E, F, G, H
  • Documents, including:
    • Interim final rule (February 27, 1975)
    • Proposed rule (April 8, 1974)

1974 Initial Rulemaking

Established BPT, BAT, NSPS, PSNS requirements: Subparts A, B, C
  • Documents, including:
    • Final rule (April 8, 1974)
    • Proposed rule (November 30, 1973)

Additional Information

For additional information regarding the NFMM Effluent Guidelines, please contact Ahmar Siddiqui ( or 202-566-1044.

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