Memorandum provides interim guidance for determining which potentially responsible parties (PRPs) qualify for treatment as de minimis waste contributors. The memorandum addresses amendments to the Comprehensive Environmental Response, Compensation, and Liability (CERCLA, commonly referred to as Superfund), as amended by section 122(g)(1)(A) of the Superfund Amendments and Reauthorization Act of 1986 (SARA), Pub. L. No. 99-499. Issued 6/19/1987.