This exploratory experimental research project was conducted (1975-1983) to assess the relative effectiveness and durability of a wide variety of liner materials when exposed to hazardous wastes under conditions that simulate different aspects of service in on-land waste storage and disposal facilities. The materials studied included compacted soil, polymer-treated bentonite-sand mixtures, soil cement, hydraulic asphalt concrete, sprayed-on asphalt, and 31 flexible polymeric membranes based on polyvinyl chloride, chlorinated polyethylene, chlorosulfonated polyethylene, ethylene propylene rubber, neoprene, butyl rubber, elasticized polyolefin, and polyester elastomer. Four semicrystalline polymeric sheetings (polybutylene, low-density polyethylene, high-density polyethylene, and polypropylene), though not compounded for use as liners, were included in the study because of their known chemical-resistance and use in applications requiring good chemical and aging resistance. (Copyright (c) 1986 ISWA.)