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Michael Infuma October 20,2003 Permitting. An application for drilling permits for the installation of the soil penetrations and monitoring wells are being forwarded to the San Joaquin County Health Department(SJCHD)with this Work Plan. Soil Borings and Sampling. Delta proposes to advance six soil penetration borings to approximately 55-80 feet bsg. The locations of the proposed soil borings are shown on the Figure included in Enclosure A. The soil borings will be advanced by the hydraulic push technology method. Soil samples will be collected at five-foot intervals and logged to the total depth drilled. Soil types encountered will be classified using the Unified Soil Classification System, Visual/Manual Method, and recorded on a soil-boring log. Soil samples collected for lithologic description will also be field measured for volatile organics using a photo-ionization detector(PID) and recorded on the boring log. Field methods and procedures to be used by Delta during installation of the soil boring are summarized in Enclosure B A minimum of two soil samples will be selected from each boring for chemical analysis based on field screening results, depth of soil samples and soil lithology. Samples will be submitted to Kiff Analytical lic, Davis, (California) for analysis of benzene, toluene, ethylbenzene, and total xylenes (BTEX), methyl tertiary butyl ether and TPHg using EPA Method 8260. Soil samples will be collected using the procedures described in Enclosure B. Monitoring Well Installation. Based on soil sample laboratory analyses result, it may become necessary to install groundwater monitoring wells. Wells will be constructed of 2-inch diameter, flush-threaded, Schedule 40 PVC casing. The wells will be constructed with 10 feet of screen above the water table and 10 feet beneath the water table. (approximately 55 to 75 feet bsg)with 0.020-inch slotted casing. The annular space of the well will be backfilled with Lonestar No. 3 sand to approximately two feet above the screened section. Following installation of the filter pack, each monitoring well will be surged with a surge block to set the filter pack material and additional sand will be added to the annulus if required to maintain the filter pack over the top of the well screen. A 1-to 2-foot thick bentonite seal will be emplaced above the filter pack. The remaining annulus will be filled with cement/bentonite slurry (grout), mixed in accordance with SJCHD specifications, to within six inches of surface grade. The surface will be completed with an 8-inch traffic rated well box set in concrete. Well construction details are included in Enclosure C. Stockpile Sampling and Disposal of Drill Cuttings. Soil cuttings generated during drilling activities will be placed on and covered by plastic sheeting onsite pending evaluation of disposal options. A minimum of four soil samples will be collected from the cuttings using the methods described in Enclosure B.The samples will be submitted to Kiff where they will be composited into one sample. The composite sample will be analyzed for BTEX and TPHg by EPA Method 8260 and total lead by EPA Method 6010. Based on the laboratory analytical results,the soil cuttings will be transported to an appropriate landfill for disposal. Well Development. The wells will be developed a minimum of 72 hours after completion. The wells will be developed by surging the well with a surge block followed by purging with a disposable bailer or centrifugal pump. Surging and purging will be repeated until purge water is relatively sediment free. If the well is purged dry during development,the well will be allowed to recharge and will be purged dry again a minimum of three times. The water generated during development will be containerized on-site pending evaluation of disposal options. A licensed waste hauler will be contracted to dispose of the purge water.