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a 1. 0 Introduction/Purpose As required by the Central Valley Regional Water Quality Control Board (RWQCB) , additional investigation is proposed in conjunction with the Re-Manufacturing surface impound- ment characterization and closure. The characterization and closure activities are being conducted under the juris- diction of the RWQCB and the Toxic Pits Cleanup Act of 1984 (TPCA) . To further assess the lateral and vertical extent of soils affected by operations at Re-Manufacturing, Water- Work proposes to drill, log and sample additional shallow soil borings. Soil samples will be collected in locations shown on Figure 1. Because of the rigid time schedule mandated by the RWQCB and substantial enforcement actions pending against Re- Manufacturing for failure to comply with the dictated time schedule, work must commence as soon as possible. 1. 1 Soil Sampling Methodology Eight six-inch diameter soil borings will be drilled using a hollow-stem auger drill rig under C57 license. Borings will be drilled to characterize the lead concentrations in shallow soils as well as identify soil stratigraphy (native vs. fill) . Select borings will be drilled to 15 feet to provide a cross-section of site lithology and valid statis- tical representation of lead concentration in native soils. Drill cuttings will be logged continuously for characteri- zation of soil type. Subsurface lithology will be charac- terized according to the Unified Soil Classification System by an experienced geologist or civil engineer and recorded on boring logs. Samples will be collected at 1 and 5 feet below ground surface in all borings to observe lead concentrations and at approximately 15 feet or within native soils immediately below fill material in four borings to provide information on stratigraphy and native soil conditions. Samples will be collected using a 2-inch diameter by 18- inch long modified California split spoon sampler lined with 6-inch long thin-walled brass soil tubes. The sampler will be driven its entire length into undisturbed soil by a 140-pound drop or hydraulic hammer. Prior to sample collection, the sampler will be decontami- nated by washing in a solution of trisodium phosphate (TSP) and tap water and double rinsed in tap water. Augers will be decontaminated between borings using a high-pressure steam cleaner. Water generated during decontamination will be contained and stored in 55-gallon labelled drums on site and properly disposed at a later date with authorization from RWQCB staff. 1