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Harding Lawson Associates January 14, 1991 20264,004.02 John Breuner Company Mr. Peter Meier Page 5 Prior to the start of drilling, HLA will obtain the necessary permits and will contact pertinent public and private entities to locate the underground utilities in the site vicinity. The boring will be drilled using a truck-mounted drill rig equipped with 8-inch-diameter hollow-stem augers and will extend to an approximate depth of 50 feet or to the water table,whichever is shallower. The soil boring will be logged continuously by a HLA field geologist under the supervision of a California registered geologist. Soils will be classified in accordance with the Unified Soil Classification System (ASTM D2488-85, D2487-85, D2488-85). Soil samples will be collected at approximately 5-foot intervals or at any significant change in lithology. Soil samples will be collected using a 3-inch outside diameter split sleeve sampler lined with stainless steel sample tubes. Samples will be visually inspected and an organic vapor analyzer(OVA)or equivalent instrument will be used to screen samples for petroleum vapors. One sample from each sample interval will be retained in the stainless steel tubes, sealed, labeled, and placed in a refrigerated environment pending subsequent laboratory analysis. All soil samples will be collected in accordance with guidelines established by the RWQCB. Soil samples from the boring will be submitted to a state-certified analytical laboratory to be analyzed for TPH as gasoline and diesel by modified EPA Test Method 8015 and for BTEX by EPA Test Method 8020. After completion of the drilling and sampling, the boring will be abandoned by backfilling with a neat cement grout. The grout will be pumped into the boring using a tremie pipe until the hole is completely filled. Decontamination All downhole drilling and sampling equipment will be decontaminated prior to use to minimize the possibility of cross contamination. The augers will be steam cleaned prior to transport to the site. The soil sampling equipment will be washed in a low phosphorous soap solution and double rinsed with tap water between each sampling. Water used to clean and rinse the equipment and soil cuttings produced during drilling will be contained in 55-gallon drums and stored onsite pending receipt of laboratory analytical results. Waste Material Storage If soil is excavated, this material will be encased in visqueen and stored onsite. Soil cuttings produced during drilling of the boring will be contained in 55-gallon steel drums and stored onsite. On the basis of the results of analytical testing, the soil will be disposed in accordance with state and local regulations. Task 3,Report Preparation After the completion of all field work and upon receipt of the analytical results, HLA will prepare a written report summarizing the work performed and presenting conclusions and recommendations regarding site conditions. Additionally, this report will present HLA's evaluation of the potential for the petroleum hydrocarbons to migrate to groundwater and the magnitude of the potential impact to local groundwater quality.