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Cone Penetration Testing and Groundwater Sampling Procedures The procedures that will used for cone penetration testing (CPT) and collecting groundwater grab samples are presented below. Permits for the field investigation will be obtained from the San Joaquin County Public Works Agency prior to the field work. Cone Penetration Testing The Cone Penetration Tests (CPT) will be carried out using an integrated electronic cone system. The CPT soundings will be performed in accordance with ASTM standards (D3441). A 10-ton capacity cone will be used for all the soundings. The cone will record tip resistance(Qc), sleeve friction(Fs),and dynamic pore pressure(Ut)at 5 cm depth intervals. These parameters will be printed simultaneously on a printer and stored electronically for future analysis and reference. A complete set of baseline readings will be taken prior to each sounding to determine temperature shifts and any zero load offsets. Monitoring base line readings ensures that the cone electronics are operating properly. The estimated total sounding depth is between 80 and 100 feet below ground surface(BGS)but will ultimately be determined in the field by IT Corporation(IT)personnel. Stratigraphic interpretation will be based on relationships between tip resistance (Qc), sleeve friction (Fs), and dynamic pore pressure(Ut). The friction ratio (Rf),which is the sleeve friction divided by the tip resistance,is a calculated parameter which is used to infer soil type. Generally, cohesive soils (clays)have high friction ratios, low tip resistance, and generate large excess pore water pressures. Cohesionless soils (sands) have lower friction ratios, high tip resistance, and generate little in the way of excess pore water pressures. The interpretation of soil encountered will be based on correlation developed by Robertson et al, 1986. Pore Pressure Dissipation Tests (PPDT's) will be taken at various intervals in order to measure hydrostatic water pressures and approximate depth to groundwater table. In addition,the PPDT data may be used to estimate the horizontal permeability (kh) of the soil. The correlation to permeability is based on the time required for 50 percent of the measured dynamic pore pressure to dissipate (tso)• Pore water pressure dissipations will be recorded at 5-second interval, when appropriate during pauses in the penetration. Work Plan IT Corporation Page A - 1 All Pure,Tracy