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Water: Iron & Steel

Iron and Steel Manufacturing Effluent Guidelines

steel mill

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EPA promulgated the Iron and Steel (I&S) effluent guidelines and standards (40 CFR Part 420) in 1982, and amended the regulation in 1984, 2002 and 2005. The regulation covers any facility that is engaged in iron or steel manufacturing, forming, and finishing, including coke manufacturing. EPA estimates there are 254 iron and steel facilities discharging directly to surface waters or indirectly through publicly owned treatment works (POTWs). The I&S effluent guidelines and standards are incorporated into NPDES permits for direct dischargers or permits or other control mechanisms for indirect dischargers (see Pretreatment Program).

What is the Iron and Steel Industry?

Iron and steel manufacturing processes include cokemaking, sintering, briquetting, ironmaking (including direct-reduced ironmaking), steelmaking, vacuum degassing, ladle metallurgy, casting, hot forming, forging, and finishing (e.g., acid pickling, descaling, cold forming, surface cleaning, hot coating and annealing).

Facilities Covered

The I&S regulation applies to facilities organized into 13 subcategories:

  • Subpart A: Cokemaking
  • Subpart B: Sintering
  • Subpart C: Ironmaking
  • Subpart D: Steelmaking
  • Subpart E: Vacuum Degassing
  • Subpart F: Continuous Casting
  • Subpart G: Hot Forming
  • Subpart H: Salt Bath Descaling
  • Subpart I: Acid Pickling
  • Subpart J: Cold Forming
  • Subpart K: Alkaline Cleaning
  • Subpart L: Hot Coating
  • Subpart M: Other Operations (direct-reduced iron production, briquetting, forging)

These activities are included within the following groups in the North American Industrial Classification System (NAICS):

  • NAICS 3311 Iron and Steel Mills and Ferroalloy Manufacturing
  • NAICS 3312 Steel Product Manufacturing from Purchased Steel

Note: the NAICS group listings are provided as a guide and do not define the coverage of the I&S rule. For precise definitions of coverage, see the applicability sections in 40 CFR Part 420.

2005 Amendment

EPA restored the provision that allows the use of alternative oil and grease limitations in NPDES permits (known as the “water bubble”) and corrected errors in the effective dates of new source performance standards.

Final Rule

Proposed Rule

2002 Amendment

EPA revised Subparts A (cokemaking), B (sintering) and D (steelmaking), and added new Subpart M (other operations). The Agency also deleted provisions covering obsolete operations: beehive coke ovens, ferromanganese blast furnaces, and open hearth furnace steelmaking.

Final Rule

Proposed Rule

1984 Amendment

  • May 17, 1984 Federal Register Notice: 49 FR 21024

1982 Final Rule

Additional Information

For additional information regarding Iron and Steel effluent guidelines, please contact Ahmar Siddiqui, siddiqui.ahmar@epa.gov or 202-566-1044.


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