“…The hydraulic conductivity of till derived from sedimentary rocks is typically about 8.5 x 10'3 ft/d (Melvin and others, 1992b). Values reported by Melvin and others (1992a;1992b) agree with those cited by other investigators (Mazzaferro and others, 1979;Randall and others, 1988;Stephenson and others, 1988). Melvin and others (1992a;1992b) also report a porosity of these tills that ranges from 18 to 40.1 percent, with a typical value of about 25 percent.…”