Grain Mills Effluent Guidelines

The EPA initially promulgated the Grain Mills Effluent Guidelines and Standards (40 CFR Part 406) in 1974 and 1975 and amended the regulation between 1975 and 1986. The regulation covers directdirectA point source that discharges pollutants to waters of the United States, such as streams, lakes, or oceans. and indirectindirectA facility that discharges pollutants to a publicly owned treatment works (municipal sewage treatment plant). dischargers. The Effluent Guidelines and Standards are incorporated into NPDES permits for direct dischargers and permits or other control mechanisms for indirect dischargers (see Pretreatment Program).

On this page:

• What is the Grain Mills Industry?
• Wastestreams, Pollutants, and Subcategories
• Rulemaking History
• Additional Information

What is the Grain Mills Industry?

The industry comprises grain operations in several product segments:

1. Cereal grains. Corn, wheat, and rice milling and processing are covered in the Part 406 regulation.
2. Animal feed
3. Breakfast cereal manufacturing
4. Wheat starch and gluten manufacturing

• 311119: Other Animal Food Manufacturing
• 311211: Flour Milling
• 311212: Rice Milling
• 311221: Wet Corn Milling
• 311230: Breakfast Cereal Manufacturing

Wastestreams

The industry's principal wastestreams are:

• In multiple subcategories:
  • grain cleaning
  • cooking
• In corn wet milling plants:
  •  modified starch washing
  •  condensation from steepwater evaporation
  •  syrup refining

Regulated Pollutants

• BOD₅
• TSS
• pH

Regulation Subcategories

Rulemaking History

Amendments

• BCT amendments:
  • Revised methodology documents:
    • Final Rule (July 9, 1986)
    • Proposed Rule (October 29, 1982)
  • Initial methodology documents:
    • Final Rule (August 29, 1979)
    • Proposed Rule (August 23, 1978)

In addition to the BCT amendments, portions of Part 406 were revised between 1975 and 1977 pursuant to litigation. For the current regulatory requirements see 40 CFR Part 406.

• Supplemental Development Document – Corn Wet Milling (Subpart A) (1978)

Initial Rulemaking

1975 rule ("Phase II")

• Documents:
  • Final Rule (January 3, 1975)
  • Development Document (December 1974)
  • Proposed Rule (September 17, 1974)

1974 rule ("Phase I")

• Documents:
  • Final Rule (March 20, 1974)
  • Development Document (March 1974)
  • Proposed Rule (December 4, 1973)

Additional Information

For additional information regarding Grain Mills Effluent Guidelines, please contact Meghan Hessenauer (hessenauer.meghan@epa.gov) or 202-566-1040.