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s Manteca Unified School District kJ Soil&Groundwater Investigation Report II Page: 4 consistency of the earth materials, pertinent soil or bedrock characteristics, and any evidence of contamination will be noted. All water-bearing zones and the depths at which they are encountered are noted on these logs. The borings were drilled in such a manner as to prevent cross contamination between strata. Water samples were taken at the soil/groundwater interface, and the borings were then sealed with a cement mixture. 2.2 Soil Sampling All soil sampling equipment was thoroughly steam cleaned before and between sampling to prevent cross contamination. Relatively undisturbed soil samples were taken at intervals of not more than five feet(5') in order to evaluate the subsurface materials. The soil samples were obtained using a Geoprobe® core sampler with plastic liners. The sampler was pushed (Direct Push Technology) continuously by the hydraulically Cpowered, percussion system. The laboratory samples did not have headspace and were immediately sealed in their liners using plastic caps. The remaining sample was removed from its liner to be used as an aide to the on-site geologist in logging the material at that depth. All soil samples were delivered, under chain of custody, to an analytical laboratory licensed by the State of California for hazardous materials work. The samples were analyzed for Total Petroleum Hydrocarbons (Diesel) and BTEX.` If soil samples were positive for total petroleum hydrocarbons as diesel the sample with the highest concentration was analyzed for .Polynuclear Aromatics (PNA s) by Method 8270. Analysis was conducted by GeoAnalytical Laboratories, Inc., in Modesto, California. 2.3 Groundwater Sampling All sampling equipment, including the stainless steel Geoprobe® screen point, used by sampling personnel, was disassembled and steam cleaned prior to commencement of sampling. Water samples were collected through a Teflon tube with a ball check valve assembly. The groundwater samples were analyzed or extracted within 14 days according to their EPA methods. It was analyzed for Total Petroleum Hydrocarbons (Diesel) and BTEX (Benzene, Toluene, Xylene, and Ethyl Benzene). All water samples were analyzed for Polynuclear Aromatics (PNA's) by Method 8270. Analysis was conducted by GeoAnalytical Laboratories, Inc. in Modesto, California. 3.0 SITE GEOLOGY AND HYDROGEOLOGY The shallow subsurface at the District's Grounds Shop Y composed.facility is of fine to j very fine well sorted silty brown unconsolidated sands to a depth of 14 to 16 feet below L