"Based on an extensive survey of the literature, this report provides a technical basis for predicting the transport of fluids through polymeric liners used to confine pollutants in landfills and impoundments. When a mixture of organic fluids, water, salts, and other substances are confined by an intact liner, first the organic fluids permeate according to their mobilities, then water. Salts, macromolecules, and microorganisms remain confined. These phenomena indicate that fluids are transported by the permeation mechanism and that properly selected and installed liners made with commodity resins can be effective. Organic fluids can be one of the major factors in determining de minimis values. These permeation rates can be appreciable; therefore, impoundments with organic fluids must be selectively designed so that adequate protection of health and the environment is maintained."