Effluent Guidelines (also referred to as Effluent Limitation Guidelines (ELGs)) are U.S. national standards for wastewater discharges to surface waters and publicly owned treatment works (POTW) (also called municipal sewage treatment plants). The United States Environmental Protection Agency (EPA) issues Effluent Guideline regulations for categories of industrial sources of water pollution under Title III of the Clean Water Act (CWA).[1] The standards are technology-based, i.e. they are based on the performance of treatment and control technologies (e.g., Best Available Technology). Effluent Guidelines are not based on risk or impacts of pollutants upon receiving waters.[2]

Since the mid-1970s, EPA has promulgated ELGs for 59 industrial categories, with over 450 subcategories. Effluent Guidelines currently control pollution at approximately 40,000 facilities that discharge directly to the nation's waters, 129,000 facilities that discharge to POTWs, and construction sites. Effluent Guidelines are implemented in water discharge permits issued to facilities through the National Pollutant Discharge Elimination System (NPDES).[3]


Regulated pollutants vary by industry category, with effluent limitations typically expressed as mass loadings or concentrations. The regulations cover pollutants for which there are approved analytical testing methods. EPA has published many methods in its regulations,[4] and has approved the use of other methods published by peer-reviewed sources, such as Standard Methods.[5] Although the effluent limitations are based on the performance of control and treatment technologies (and not the impacts to receiving waters), the regulations do not require discharging facilities to use specific technologies. The facilities may choose any technologies to meet the numerical limitations.[3]

In the 1972 CWA Congress specified an initial list of categorical regulations that EPA was required to promulgate.[6] The 1977 CWA amendments provided a list of pollutant and pollutant groups to be considered by the agency in developing regulations.[7] EPA is also required to review and revise regulations as needed, and since 1972 it has promulgated ELGs for 59 industrial categories, with over 450 subcategories. Approximately 40,000 facilities that discharge directly to the nation's waters, 129,000 facilities that discharge to POTWs, and construction sites, are covered by the regulations. The regulations annually prohibit the discharge of 700 billion pounds of pollutants into U.S. surface waters.[8]

The effluent limitations for the Construction and Development category are narrative in format and do not specify numeric pollutant limits. The requirements consist of erosion controls and sediment controls, soil stabilization practices and pollution prevention practices (such as minimizing exposure of building materials, pesticides and other chemicals).[9]

In the early years of the program (1970s-1980s) the agency published analytical methods for a list of 126 "priority pollutants," consisting of various toxic pollutants. Subsequently the agency has issued methods and regulated pollutants beyond those in the initial priority list.[7][10]

Facilities that directly discharge to "waters of the United States" are required to obtain NPDES permits, and effluent guideline requirements are incorporated into these permits. Indirect dischargers (i.e. facilities discharging to POTWs) are subject to effluent guideline requirements called "Pretreatment Standards."[3][11]

Existing regulations

This table lists the 59 Effluent Guidelines categories published by EPA.[2]

Category Name 40 CFR Initial Promulgation Year Most Recent Update
Airport Deicing    449 2012 2012
Aluminum Forming    467 1983 1988
Asbestos Manufacturing    427 1974 1975
Battery Manufacturing    461 1984 1986
Canned and Preserved Fruits and Vegetable Processing    407 1974 1976
Canned and Preserved Seafood (Seafood Processing)    408 1974 1975
Carbon Black Manufacturing    458 1976 1978
Cement Manufacturing    411 1974 1974
Centralized Waste Treatment    437 2000 2003
Coal Mining    434 1975 2002
Coil Coating    465 1982 1983
Concentrated Animal Feeding Operations    412 1974 2008
Concentrated Aquatic Animal Production (Aquaculture)    451 2004 2004
Construction and Development    450 2009 2014
Copper Forming    468 1983 1986
Dairy Products Processing    405 1974 1974
Dental Office    441 2017 2017
Electrical and Electronic Components    469 1983 1983
Electroplating    413 1974 1983
Explosives Manufacturing    457 1976 1976
Ferroalloy Manufacturing    424 1974 1974
Fertilizer Manufacturing    418 1974 1975
Glass Manufacturing    426 1974 1975
Grain Mills    406 1974 1974
Gum and Wood Chemicals Manufacturing    454 1976 1976
Hospitals    460 1976 1976
Ink Formulating    447 1975 1975
Inorganic Chemicals Manufacturing    415 1982 1982
Iron and Steel Manufacturing    420 1974 2005
Landfills    445 2000 2000
Leather Tanning and Finishing    425 1982 1996
Meat and Poultry Products    432 1974 2004
Metal Finishing    433 1983 1986
Metal Molding and Casting (Foundries)    464 1985 1985
Metal Products and Machinery    438 2003 2003
Mineral Mining and Processing    436 1975 1979
Nonferrous Metals Forming and Metal Powders    471 1985 1989
Nonferrous Metals Manufacturing    421 1976 1990
Oil and Gas Extraction    435 1975 2016
Ore Mining and Dressing (Hard Rock Mining)    440 1975 1988
Organic Chemicals, Plastics & Synthetic Fibers    414 1987 1993
Paint Formulating    446 1975 1975
Paving and Roofing Materials (Tars and Asphalt)    443 1975 1975
Pesticide Chemicals    455 1978 1996
Petroleum Refining    419 1974 1982
Pharmaceutical Manufacturing    439 1976 2003
Phosphate Manufacturing    422 1974 1974
Photographic    459 1976 1976
Plastics Molding and Forming    463 1984 1984
Porcelain Enameling    466 1982 1985
Pulp, Paper and Paperboard    430 1974 2002
Rubber Manufacturing    428 1974 1974
Soap and Detergent Manufacturing    417 1974 1975
Steam Electric Power Generating    423 1974 2020
Sugar Processing    409 1974 1984
Textile Mills    410 1974 1982
Timber Products Processing    429 1974 1981
Transportation Equipment Cleaning    442 2000 2000
Waste Combustors    444 2000 2000

Program plans

EPA periodically publishes a list of ongoing and new regulation projects, and a list of categories that it is considering for regulation, in its "Effluent Guidelines Program Plan." Program Plan 15, published in January 2023, announced several regulatory and research projects. According to the agency's "PFAS Strategic Roadmap", it is continuing to evaluate options to reduce discharges of per- and polyfluoroalkyl substances (PFAS) from a variety of industrial sectors.[12] In this regard EPA has decided that changes to the Landfills regulation (40 CFR part 445) are necessary, to address discharges of PFAS from landfill leachate.[13]

EPA will conduct research on the Textile Mills category (40 CFR part 410) to learn more about its PFAS usage and discharge characteristics. The agency will study PFAS discharged to POTWs by various industries, including categories that have recently been examined. EPA intends to confirm the origins of PFAS wastewater and assist POTWs in determining whether source-level controls are necessary. The Concentrated Animal Feeding Operations Category (40 CFR part 412) will also be investigated. The POTW influent study will include monitoring of the Electrical and Electronic Components Category (40 CFR part 469) for PFAS discharge data even though EPA is not currently seeking additional action for this category. Additionally, EPA will keep an eye on PFAS use and emissions from airports and the Pulp, Paper, and Paperboard Category (40 CFR part 430).[13]

See also


  1. ^ United States. Clean Water Act (CWA). CWA section 301(b), 33 U.S.C. § 1311(b); sec. 304(b), 33 U.S.C. § 1314(b); sec. 306, 33 U.S.C. § 1316; sec. 307(b), 33 U.S.C. § 1317(b), sec. 307(c), 33 U.S.C. § 1317(c).
  2. ^ a b "Industrial Effluent Guidelines". Washington, D.C.: U.S. Environmental Protection Agency (EPA). 2023-03-08.
  3. ^ a b c "Learn About Effluent Guidelines". EPA. 2022-09-09.
  4. ^ EPA. "Guidelines Establishing Test Procedures for the Analysis of Pollutants." Code of Federal Regulations, 40 CFR 136
  5. ^ Baird, Rodger B.; Clesceri, Leonore S.; Eaton, Andrew D.; et al., eds. (2017). Standard Methods for the Examination of Water and Wastewater (23rd ed.). Washington, DC: American Public Health Association. ISBN 9780875532875.
  6. ^ CWA sec. 306(b)(1)(A)
  7. ^ a b "Toxic and Priority Pollutants Under the Clean Water Act". EPA. 2021-07-10.
  8. ^ "Effluent Guidelines Plan". EPA. 2023-01-20.
  9. ^ EPA. "Construction and Development Point Source Category." Code of Federal Regulations, 40 CFR 450
  10. ^ "Clean Water Act Analytical Methods". EPA. 2023-02-22.
  11. ^ "Pretreatment Standards and Requirements-Categorical Pretreatment Standards". EPA. 2022-10-03.
  12. ^ "PFAS Strategic Roadmap: EPA's Commitments to Action 2021-2024". EPA. 2023-04-24.
  13. ^ a b "Current Effluent Guidelines Program Plan". EPA. 2023-03-30.