December 3, 1987

Honorable Max Baucus
United States Senate
Washington, D.C.  20510

Dear Senator Baucus:

Thank you for your November 3, 1987, letter concerning the prohibitions on land disposal of California list metal-bearing and cyanide-containing wastes.

The statutory language in the Resource Conservation and Recovery Act (RCRA) Section 3004(d) identifies California list wastes containing free cyanide and metals was waste groups that include "liquid hazardous waste, including free liquids associated with any solid or sludge."  In consideration of this language, the Agency believed it appropriate to require that the concentration of restricted constituents in the filtrate, generated from the Paint Filter Liquids Test, be evaluated in determining compliance with the statutory prohibition levels. However, as noted in the August 12, 1987, Notice of Data Availability (52 FR 29998), serious consideration will be given
to the adoption of treatment standards expressed as constituent concentrations using the Extraction Procedure (EP) toxicity test or Toxicity Characteristic Leaching Procedure (TCLP).  Such an approach more closely reflects the analytical methodology used for the data presented in the Notice.  Conversely, the Agency
must also take into account that a number of commenters to the December 11, 1986, California list proposed rule were opposed to the use of a leach test, specifically the TCLP, to develop a waste extract for further testing.

The public comment period for the August 12, 1987, Notice was extended in additional 30 days and recently closed on November 12, 1987.  The Agency is currently in the process of reviewing comments and analyzing the submitted data.  After considering all public comments received on the issues addressed in this Notice, the Agency plans to proceed aggressively toward promulgation of a final rule.

If I can be of further assistance, please let me know.


J. Winston Porter
Assistant Administrator