Memorandum sets out steps to ensure compliance by potentially responsible parties (PRPs) with EPA’s active orders and settlement agreements for Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA, commonly referred to as Superfund) studies, response work, and cost recovery. Requested each Region to conduct an assessment of PRP compliance with CERCLA orders and consent decrees and prepare an action plan for responding to every instance of substantial non-compliance. Issued 11/3/1998.