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Effluent Guidelines

Timber Products Processing Effluent Guidelines

""EPA promulgated the Timber Products Processing Effluent Guidelines and Standards (40 CFR Part 429) during 1974-6 and amended the regulation in 1981. The regulation covers direct and indirect dischargers. 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 Timber Products Processing Industry?

The timber products processing industry consists of a diverse group of manufacturing plants whose primary raw material is wood and whose products range from finished lumber and other wood building products to hardboard and preserved wood. This industrial group comprises thousands of facilities, including:
  • sawmills
  • millwork and finishing operations
  • veneer and plywood plants
  • wood preserving plants
  • particleboard plants
  • hardboard plants, and
  • insulation board plants.
Timber products processing activities are included within the following NAICS groups:
  • 3211: Sawmills and Wood Preservation
  • 3212: Veneer, Plywood, and Engineered Wood Product Manufacturing
  • 337: Furniture and Related Product Manufacturing

Note: The NAICS listing is provided as a guide and does not define the coverage of the Timber Products Processing category. For precise definitions of coverage, see the applicability sections in 40 CFR Part 429.

Pollutants and Subcategories

Regulated Pollutants

The regulated pollutants vary by subcategory, and include:

  • arsenic
  • biochemical oxygen demand
  • chemical oxygen demand
  • copper
  • chromium
  • pH (abnormally high or low)
  • phenols
  • oil & grease
  • suspended solids

Portions of 15 subcategories are subject to zero discharge requirements.

Regulation Subcategories

  1. Barking
  2. Veneer
  3. Plywood
  4. Dry Process Hardboard
  5. Wet Process Hardboard
  6. Wood Preserving—Water Borne or Nonpressure
  7. Wood Preserving Steam
  8. Wood Preserving—Boulton
  9. Wet Storage
  10. Log Washing
  11. Sawmills and Planing Mills
  1. Finishing
  2. Particleboard
  3. Manufacturing Insulation Board
  4. Wood Furniture and Fixture Production Without Water Wash Spray Booth(s) or Without Laundry Facilities
  5. Wood Furniture and Fixture Production with Water Wash Spray Booth(s) or with Laundry Facilities

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Rulemaking History

Minor Amendments

  • Final Rule (July 30, 2004)
    Modification to definition of "process wastewater"
  • Final Rule (November 23, 1981)
    Revision of NSPS applicability for Subpart E; error corrections

1981 Amendment

Revisions pursuant to 1977 Clean Water Act: wood preserving, insulation board, and wet process hardboard sectors; also reorganization of some subcategories.
  • Documents, including:
    • Final Rule (January 26, 1981)
    • Development Document (January 1981)
      Industry description, wastewater characterization, treatment technologies, regulatory compliance cost estimates and pollutant loadings for the final rule (wood preserving, insulation board, and wet process hardboard sectors only)
    • Proposed Rule (October 31, 1979)

1976 Amendment

"Phase III" rule: PSES; Subparts A–M, Q–R
  • Documents, including:
    • Final Rule (December 9, 1976)
    • Proposed Rule (June 2, 1975)
    • Proposed Rule (January 16, 1975)
    • Proposed Rule (April 18, 1974)

1975 Amendment

"Phase II" rule: BPT, BAT, NSPS, PSNS; Subparts I–M
  • Documents, including:
    • Final Rule (January 16, 1975)
    • Proposed Rule (August 26, 1974)

1974 Initial Rulemaking

"Phase I" rule: BPT, BAT, NSPS, PSNS; Subparts A–H
  • Documents, including:
    • Final Rule (April 18, 1974)
    • Development Document (April 1974)
    • Proposed Rule (January 3, 1974)

Additional Information

For additional information regarding Timber Products Processing Effluent Guidelines, please contact Ahmar Siddiqui ( or 202-566-1044.

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