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device will be utilized. This approach is a preliminary means of ascertaining the existence of groundwater contamination at a certain location and will allow for placement of monitoring wells in optimal locations. In addition, the use of the Hydro-Punch will minimize the number of wells that have to be installed by defining the extent of the contamination before the well locations are selected (does away with trial and error approach) . A hollow stem auger drilling rig with 4-inch augers will drill boreholes whose base lies directly above the water table. The depth to water will be determined in the field from the monitoring wells in place at the site prior to commencement of drilling. Soil samples will be obtained at five foot intervals using an 18-inch, modified California split-spoon sampler equipped with brass sleeves and the borehole logged according to the Unified Soil Classification System (USCS) . When the borehole is completed the drilling rod will be retracted and the Hydro-Punch sampling device attached. The sampler will be driven approximately four to five feet into the saturated zone and the outer casing retracted 1.5 feet so that water can flow through the perforated inner screen via hydro-static pressure. The apparatus will remain in the saturated zone for a period of 40 to 50 minutes so that an adequate sample volume can be extracted from the aquifer (shorter time period for more permeable sediments) . At this time, the sampling apparatus will be extracted from the borehole and a groundwater sample obtained. The sample bottles will be stored in an iced cooler until their delivery to a California Department of Health Services (DHS) certified lab. Groundwater samples will be analyzed for the following constituents: * BTXE EPA Methods 5030 and 8020 * Total Petroleum Hydr. EPA Method 8015 (Hi and Lo BP) The auger flights and Hydro-Punch apparatus will be steam-cleaned prior to its re-use at another borehole. Decontamination of the soil sampling equipment will be performed in the following manner: * Rinse with tap water * Wash with tap water and non-phosphate detergent * Rinse twice with de-ionized water Drilling permits will be obtained from the San Joaquin Local Health District and underground utilities located prior to the initiation of drilling activities at the site. The latter task will be accomplished by interviewing Stockton Scavenger employees, and contacting USA Underground. The sealing of the boreholes will be performed under the supervision of a County Inspector using Volclay 3