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File No. 20-1008-49.001 KLEIN FELDER July 8, 1993 DflMTROMETER TEST General A sealed double-ring infiltrometer (SDRI) was utilized for in-situ permeability testing of the newly-placed SP/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. uipment The SDRI used for our testing program consisted of two rings that were fabricated from heavy plastic. The inner ring was 36 inches in diameter, '/a-inch thick, cylindrically-shaped, and approximately 18 inches high. The outer ring was 72 inches in diameter, domed, approximate- ly 34 inches high, and sealed to reduce evaporation. During the test, the applied head in the outer and inner rings was kept constant and identical to minimize the hydraulic head trending 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. The SDRI equipment used for our testing program is shown schematically on Plate 2. Installation Circular trenches, approximately 4 and 6 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, these trench depths were less than 50 percent of the liner (test pad) thickness as recommended by Daniel and Trautwein. The trenches were filled with a bentonite/cement/sand 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 SDRI test apparatus and field placement are attached. Measurements The SDRI was installed on May 3, 1993 and both rings were filled with water on May 7, 1993. The inner ring was left open to equalize pressure between the two rings. Beginning May 26, 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 June 11, 193. The table below summarizes the daily readings; Plate 3 graphically depicts permeability versus time. The actual location of the SDRI test was at the center of the SP/SM test pad. Copyright 1993 Kleinfelder, Inc. Page 5 of 7