The only methods which make it possible to obtain water transmission coefficients of porous media without the use of complicated experimental techniques are prediction methods based on physical properties of the medium. Simple laboratory techniques were developed to measure the physical properties needed in these prediction methods and to check these methods through a series of systematic measurements. Pore size distributions were determined by the mercury intrusion method. The permeabilities of the materials were measured with a constant head permeameter. Bulk densities and porosities were obtained with gamma ray attenuation equipment. A total of 63 samples was tested with permeabilities ranging from 1.5-39.1 square microns. The permeability of the inert porous materials considered can be predicted reliably when the pore size distribution is known. Mercury intrusion data can be used to provide the quantitative information required in transport models for water, heat and chemicals in porous media. (WRSIC abstract)