On July 26, 1982, the Environmental Protection Agency (EPA) promulgated the long awaited hazardous waste land disposal standards.¹ Publication of these regulations, which apply to hazardous waste landfills, surface impoundments, waste piles, and land treatment facilities, completes the core hazardous waste management regulatory program under Subtitle C of the Resource Conservation and Recovery Act (RCRA).² Further regulatory activity is planned, however, to "fine tune" existing regulations. The new regulations, which form the basis for granting permits³ to new and existing hazardous waste land disposal facilities, rely on a two-pronged approach for protection of human health and the environment. They establish a performance-oriented groundwater protection standard, implemented through groundwater monitoring and, if contamination is detected, corrective action. In addition, they prescribe performance-based design and operating standards aimed at preventing the release of waste and waste constituents during the facility's operating life and post-closure care period.