With the authorization of the Resource Conservation and Recovery Act (RCRA) of 1984, the U.S. Environmental Protection Agency (EPA) was required to ban the disposal of hazardous waste to the land. The Congressional mandate to ban was accompanied by a decision or 'hammer' date for each waste type. By the 'hammer' date, EPA must ban the targeted waste stream or determine that a temporary extension of the ban implementation date is warranted since insufficient alternative waste treatment capability exists. Therefore, EPA must have adequate knowledge of existing alternative (to land disposal) treatment technologies. The Agency must have data on the technical capabilities of alternative technologies, on the existing capacities of such technologies, and on the abilities of such technologies to accommodate targeted waste streams within the 'hammer' dates. The paper describes the role that EPA's Office of Research and Development is playing in supporting the Agency's deliberation with respect to the landfill ban provisions. Research programs that are currently being carried out are described in detail. Program plans for future years are also discussed.