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Section 3.0 In Situ and Laboratory Testing 3.1 In Situ Testing A falling head permeability test was conducted in PZ-1 to estimate the hydraulic conductivity of the formation adjacent to the piezometer. A slug (5-foot-long, 1-inch- ' diameter solid PVC pipe filled with sand) was submerged to just below the static water level within the piezometer.The water displaced by the submerged slug resulted in a temporary increase in water level. As the excess water drained into the formation and the water level declined back to static level, an INSITU PX-261 pressure a.• transducer and Hermit 3000 data logger were used to record the rate of water level falling. A copy of the data table summarizing the data recorded during the test and a chart showing the change in water level versus time are included in Appendix B. The Hvorslev Method (Fetter, 1994) was used to calculate the hydraulic conductivity from data collected during the falling head permeability test. The Hvorslev Method is ,,, a suitable method to calculate hydraulic conductivity for piezometers with a screen partially penetrating unconfined aquifers,as is the case with PZ-1. The calculated hydraulic conductivity was about 23.7 feet/day ($.4 x 10-3 cm/sec). 3.2 Geotechnical Laboratory Testing Geotechnical laboratory testing was performed on selected soil samples from B-1 and B-2 and consisted of dry density and moisture content determination, grain size distribution,and Atterberg limits. Smith-Emery,San Francisco, California performed the geotechnical laboratory testing. Geotechnical laboratory testing results are presented in Appendix B. 3.3 Environmental Laboratory Testing One grab water sample was collected from PZ-1 to evaluate the presence of f contaminants associated with the historic site releases. The grab groundwater sample was analyzed for pH,total coliform bacteria,fecal coliform bacteria, and chromium VI by Chromalab, Pleasanton,California. Prior to collection of the groundwater sample, the piezometer was developed and purged until the temperature, pH,conductivity, dissolved oxygen,and turbidity of the groundwater stabilized. The grab groundwater sample was collected using a disposable Teflon bailer. The collected sample was dispensed into one 500-mL unpreserved plastic container and one 100-m1 plastic sterile container. The sample was then placed in a cooler with ice until submittal to the laboratory. CDM Camp Dresser&McK.Inc. 3-1 �'+ 0:X2500L29248.GEb-T4ReporftBro kslde Pu pSUUon.doc