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0 11 91 IF 91 ). H. KLEINFELDER & ASSOCIATES File: W-2022-1/11:312 June 19, 1986 Page 8 using a truck -mounted drill rig equipped with a 6 -inch diameter continuous flight hollow stem auger. Occasional soil samples were obtained by pounding a split spoon sampler Into the soil using a 140 -pound hammer falling approximately 18 -inches. Continuous log of soils encountered in the boring was maintained in the field. In general the soil conditions encountered in the boring drilled consisted of approximately 8 feet of grey brown silty clay at the surface overlying silty sand and extended to approximately 20 feet below the ground surface. Below these depths with the exception of minor sandy and gravelly lenses, the predominate soils consisted of light tan grey sandy silty clay and clay stones to the maximum depth drilled of 225 feet. No free ground water was encountered. All soils have been classified according to the Unified Soils Classification System. A production water well was installed in November 1983, approximately 1,000 feet west of Boring B-4. This boring was drilled to approximately 800 feet and water rose under an artesian condition to approximately 52 feet below the ground surface. In July of 1982 an E -log was completed at a site near the production well. The E -log revealed possible water bearing sand stratus at approximately 250 and 575 feet. The E -log shows the 250 foot stratum to be of a less potential but the 575 foot stratum to be a probably production stratum. The production well log and the E -log both indicate relatively thick formations of clay and clay shale deposits. These relatively impervious clay and clay shale formations have prevented water from reaching the near surface, except where penetrated by production wells. The impervious soils creating the artesian condition have prevented water from reaching a static water level and will also minimize the opportunity of any potential leachate from the subject ponds from migrating to the deeper water -bearing horizons. The exception of this could be the perched water condition encountered at the location of well number 2, which was discussed in our June 7, 1985, report. In addition, a hydrogeological investigation was performed at the request of the Regional Water Quality Control Board (RWQCB) at the Musca Olive facility, to assist in the evaluation of a proposed leachate monitoring system. The following findings were included in a report dated January 8, 1986: