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j ATLANTIC RICHFIELD COMPANY,STATION 434 501 KE'17LEMAN LANE LODI,CALIFORNIA This work plan has been prepared for Atlantic Richfield Company (ARCO) Station 434, located at 501 Kettleman Lane in Loch, California. The work plan will be submitted to ' r ARCO and the San Joaquin County Environmental Health Department (County). Before commencing the work at the site,necessary permits will be acquired. Boreholes Brown and Caldwell (BC) will supervise the drilling of two boreholes and the Installation of groundwater monitoring wells in each of the two boreholes. The locations are shown on Figure 1. Two boreholes will be drilled within 5 feet of the existing I; monitoring well W-2. The boreholes will be drilled using a tn!ck-mounted drilling rig. The depth to.groundwater is approximately 55 feet. One bomhoie will be drilled to ' approximately 65 feet and one borehole will be drilled to approximately 90 feet. h. r Soil Sampling Procedures Soil samples will be taken from the deeper borehole beginning at 55 feet to the bottom f. of the hole (90 feet). Lithology hereon ground surface to 55 feet is shown or, the log for monitoring well W-2. With the exception of the zones between approximately 57 to 65 feet and 80 to 90 feet, samples will be taken at 5-foot intervals. In these two zones samples will be taken every 2.5 feet to determine the best 5-foot interval to be screened. Samples lei will be obtained using an 18-inch split-spoon drive sampler. The sampler will be driven ' into undisturbed sail to abrain rhe soil samples. Samples will then be visually inspected in the field to identify lithology. A lithologic Iog will be constructed for the 55 to 90-foot portion of the deeper borehole. ?' Groundwater Monitoring Wells Daring monitoring well installation, the following procedures will be used. These iia methods will ensure the proper identification of groundwater quality beneath the site. } -? Groundwater Monitoring 'Well Installation. Two groundwater monitoring wells will be installed in the boreholes shown on Figure 1. fA The wells will be completed with 2-inch-diameter polyviny! chloride (PVC) flush-threaded casing and will be screened with 0.020-inch slotted casing. One well will be —- -- -� screened-from-approximately-65--feet-to-60-feet-and-one_well--will be-screened--from T -- -- approximately 90 feet to 85 feet. Blank casing will extend from the top of.the perforated section to ground surface. The actual depths of the boreholes and screened intervals of L' the wells will depend on conditions encountered during drilling.