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1. SCOPE <br />This report describes results of laboratory tests conducted to determine soil water characteristic curves <br />(SWCCs) for two disturbed soil samples from the Forward Landfill. These specimens have the following <br />identification numbers: CL -8 and CL -37. <br />2. METHODS <br />The SWCC of each soil was measured using a combination of Method B (pressure plate extractor) and <br />Method D (chilled mirror hygrometer) in ASTM D 6836. Specimens for the SWCC tests were prepared at <br />optimum water content and relative compaction of 90% as directed by the requestor. A specific gravity <br />test was also conducted on each soil for computations made when reducing the data. <br />The SWCCs were prepared by combining data from the pressure plate and chilled mirror hygrometer <br />tests as described in D 6836. van Genuchten's equation was fit to the SWCC data: <br />®β€”®r β€” 1 m <br />®s β€”Or 1 +(ayr), (1) <br />where a is volumetric water content, 8r is residual water content, ®$ is saturated volumetric water content, <br />W is matric suction, and a, m, and n are fitting parameters. Equation 1 was fit to the data using a non- <br />linear least-squares optimization procedure with the constraint m = 1-n'. <br />3. RESULTS <br />Data from the SWCC tests are tabulated in the appendix. The van Genuchten parameters for the <br />SWCCs are summarized in Table 1. <br />Table 1. Summary of van Genuchten parameters. <br />Sample 8r _OS a 1/kPa n <br />CL -8 0.00 0.42 0.0219 1.22 <br />CL -37 0.00 0.39 0.0140 1.28 <br />