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KLEI NFELDER File No. 20-1008-49.001 December 9, 1993 INFILTROMETER TEST ("SM" TEST PAD) General A second sealed double-ring infiltrometer (SDRI) was utilized for in-situ permeability testing of the "SM" test pad. The SDRI apparatus and test procedures were in general accordance with those described by David Daniel and Steven Trautwein in their paper "Field Permeability Tests for Earthen Liners," S.P. Clemence, ed., 1986, Use of In Situ Tests in Geotechnical Engineering, pp. 146-160. Equipment The SDRI used for our testing program consisted of two rings that were fabricated from heavy plastic. The inner ring was 24 inches in diameter, 1/4-inch thick, domed, and approximately 18 inches high. The outer ring was 72 inches in diameter, domed, approximately 34 inches high, and sealed to reduce evaporation. We note that the inner ring diameter was 12 inches less in diameter than in the previous test. During the test, the applied head in the outer and inner rings was kept constant and identical to minimize the hydraulic head tending to drive flow between the inner and outer rings. Additionally, by keeping the water levels constant, the tendency for the inner ring to expand or contract with time was minimized and enhanced one-dimension infiltration flow (vertical) from the inner ring. Installation Circular trenches, approximately 4 and 14 inches deep, were excavated for the inner and outer rings, respectively, using a specially designed cutting tool attached to a drill rig. Since the clay liner has a minimum thickness of 12 inches, the inner trench depth was less than 50 percent of the liner (test pad) thickness as recommended by Daniel and Trautwein. The trenches were filled with a bentonite/cement grout, and the rings were set into the trenches. The grout was allowed to harden before the rings were filled with water. A system consisting of a drum, hoses, and a float valve permitted refilling of the outer ring in order to maintain a constant water level. A plastic I.V. bag filled with water was connected to the inner ring and floated in the water of the outer ring, thereby eliminating head differences and minimizing lateral flow between the two rings. Pictures of the second SDRI test apparatus are attached. Measurements The SDRI was installed on November 4, 1993 and both rings were filled with water on November 5, 1993. The inner ring was left open to equalize pressure between the two rings. Beginning November 17, 1993, the I.V. bag was filled with water from the outer ring, weighed, and connected to the inner ring. The change in weight of the I.V. bag and the temperature of the water adjacent to the inner ring were monitored daily until November 28, 1993. The table below summarizes the daily readings; Plate 3 graphically depicts permeability versus time. The actual location of the SDRI test was 20 feet north of the center of the "SM" test pad. The measurements resulted in a stabilized permeability of 3.8 x 10' cm/sec. Copyright 1993 Kleinfelder, Inc. Page 3 of 5