A study was conducted to determine the long-term effects of municipal solid waste leachate on wide variety of materials that could be used as landfill liners. To determine the effective service lives of these materials when placed in a prolonged contact with leachate or landfill conditions, 65 materials were subjected to at least one of seven different exposure tests. These materials included four admixes, two asphaltic membranes, 50 commercial polymeric membrane liners, and nine miscellaneous materials. Types of exposure tests included simulated landfill exposures.