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Revised Site Characterization Work Plan SMH Mountain House,LLC Page 3 4.0 LINED RESERVOIRS 4.1 RESERVOIR 2-LINER REMOVAL AND BACKFILL Stormwater will he removed by pumping to Reclamation Area 1 or allowing it to evaporate. Based on average evaporation rates, the complete removal of accumulated stormwater would occur by mid August 2009 or earlier. The liner material will be removed and recycled. The excavation will be filled and graded .. to the original topographic surface. 4.2 RESERVOIRS 1A AND 1B — SUBSOIL SAMPLING, RISK EVALUATION, RESIDUAL SOLIDS REMOVAL, LINER REMOVAL AND BACKFILL 4.2.1 Subsoil Sampling The project schedule will be managed so that any residual liquids (stormwater) in the reservoirs will be discharged to Reclamation Area 1 or evaporated prior to soil sampling activities. Based on average evaporation rates, the complete removal of accumulated stormwater by evaporation would occur by mid August or earlier in a nortnal rainfall year. Twelve composite soil samples (six from under each Reservoir IA and 113) will be collected to characterize the soil underlying the liners at locations shown on Figure 3, Attachment 1. The FML in Reservoir 1B will be cut away to access the subsoil at the proposed sample locations. Surface samples (0 to 6 inches) will be collected by loosening the soil with a stainless steel shovel. A stainless steel spoon will be used to place loose soil into laboratory-supplied 8-oz. glass jars. A deeper soil sample(1 foot to 18 inches) will be collected at each location by digging to approximately 1 foot below ground surface (bgs) with a stainless steel shovel and using a stainless steel spoon to place loose soil into 8-oz, glass jars. Depending upon soil conditions, the deeper soil samples may be collected by using a stainless steel hand auger and transferring the soil directly from the hand auger into laboratory-supplied glass jars. All sampling equipment will be decontaminated in the field with a solution of laboratory-grade, non-phosphate detergent and de-ionized water, and rinsed with de-ionized water prior to the collection of each individual sample. Each jar will be immediately labeled for sample identification upon collection and placed in a cooler chilled with ice for delivery in accordance with chain-of-custody procedures to a certified laboratory for analysis as specified in Table 1. Table 1 Soil Constituents and Laboratory Methods Constituents Units Type Methods Size of Container Preservatives Holding Times 6010, Metals* mg/kg Grab 7471A, 8 oz.(glass) None 6 months 7740 PH Std. Grab 150.1 8 oz. (glass) None None Electrical Conductivity Saturated Paste(EC) µmhos/cm Grab 120.1 8 oz. (glass) None 28 days Total Nitrogen mg/kg Grab 351.3/300.0 8 oz. (glass) None 1 28 days Note: "Metals include arsenic,cadmium,chromium,copper, lead,mercury,molybdenum,nickel,selenium,and zinc Units: mg/kg=milligrams per kilogram=parts per million(ppm) pmhos/cm=micro Siemens per centimeter oz.=ounce The discrete surface soil sample and the discrete soil sample collected from a depth of 1 foot bgs at each sampling location will be composited by the laboratory and analyzed for pH by EPA Method 9045C, EC w �.� CONDOR