United States
Environmental Protection
April 2003
Proposed Revisions to the
Hazardous  Waste Identification
Rule (HWIR)
      The Environmental Protection Agency (EPA) is proposing to revise the wastewater
  treatment exemptions for hazardous waste mixtures found in 40 CFR 261.3(a)(2)(iv)(A)-(G),
  also known as the "Headworks Rule Exemptions."
      The Agency, on November 17, 1981, (46 FR 56582 - 56589) promulgated the
   original wastewater treatment exemptions for hazardous waste mixtures (headworks)
   rule exemptions in response to industry concerns about over-regulation of hazardous
   waste mixtures. The headworks exemptions have been revised occasionally as new
   wastes have been added to the lists of hazardous wastes.
      The headworks rule exemptions are a part of the Resource Conservation and
   Recovery Act (RCRA) rules that define when wastes are considered to be hazardous,
   and therefore subject to the more stringent Subtitle C hazardous waste regulations.
   The exemptions determine when management of hazardous waste mixtures in a
   wastewater treatment system would result in sludges or effluent discharges that could
   be safely handled under the non-hazardous regulations.
      This action is promulgated under the authority of sections 2002(a), 3001, 3002,
   3004, and  3006 of the Solid Waste Disposal Act of 1970, as amended by both the
   Resource Conservation and Recovery Act of 1976 (RCRA) and the Hazardous and
   Solid Waste Amendments (HSWA) of 1984.

      EPA is proposing the following revisions:
         the addition of two solvents (benzene and 2-ethoxyethanol) to a list of solvents
         whose mixtures are exempted from the definition of hazardous waste under
         RCRA.  The Agency studied two other solvents, 1,1,2-trichloroethane and
         2_nitropropane, and is proposing not to take action at this time;
         the addition of an option to measure solvent chemical levels directly at the
         headworks of the wastewater treatment system to the current requirement of
         mass balancing;
         a clarification in the preamble that scrubber waters generated from the
         incineration of spent solvents listed in the headworks rule would be eligible
         for the headworks rule exemptions; and
         the addition of listed hazardous wastes (beyond discarded commercial
         chemical products) as eligible for the de minimis exemption, as well as the

   addition of non-manufacturing facilities to those that qualify for this exemption if
   certain conditions are met.
   These proposed revisions would expand the existing exemptions, resulting in a net
cost savings with no reduction in protection to human health and the environment.

For More Information
   This fact sheet and other documents related to the rule are available in electronic
format on the Internet at .For additional information, or to order paper copies of any documents, call
the RCRA Call Center. Callers within the Washington Metropolitan Area please dial
703-412-9810 or TDD 703-412-3323 (hearing impaired). Long-distance callers please
call 1-800-424-9346 or TDD 1-800-553-7672.  The RCRA Call Center operates
weekdays, 9:00 a.m. to 5:00 p.m.