No evidence was found in these tests of real differences in performance between clay, concrete, or bituminous-fiber tiles. Differences in tile outflow were due primarily to soil variation and not to tile performance. Little actual change in salinity resulted from the leaching operation in the body of soil between the tiles. In most cases as much, and often more, water was lost through seepage as was removed by the tile. Much of the water which moved through the soil followed the disturbed trench above the tile, as evidenced by the much lower salinity in that trench. Electrical conductivity of the tile effluent was inversely related to both rate and duration of tile flow. Each tile showed a unique relationship between electrical conductivity, rate, and duration of flow—probably a reflection of a unique combination of hydraulic conductivities along each tile line.