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x j, FQR P BORINGS: AES is proposing to install two monitor wells and four soil borings. The first monitor well (MW- 13D)will be installed to a total depth of 120 feet,and the second(MW-13)to a total depth of 46 feet. The four soil borings will be drilled to a total depth of approximately 120 feet. The monitor wells will be constructed with a two(2)inch diameter PVC well casing. The two (2) inch diameter 0.010" slot PVC screen will be twenty(20) feet in length in the 46 foot monitor well (the twenty feet of screen +, will allow for water fluctuations)and five(5)feet in the 120 foot monitor well (the five foot interval will be set across the most permeable contaminated zone). A filter pack of sand will be placed from the bottom of the well screen to two(2)feet above the top of each well screen. A two(2)foot thick seal of coated bentonite will be placed immediately above the sand pack interval. The remainder of i the annulus will be filled to the surface with grout. The grout will be pumped into place using a "tremie"pipe. There will be no less than five(5)gallons and no more than ten (10)gallons of water per ninety-four (94) pounds of cement. The surface of the two monitor wells will be fitted with a precast vault thoroughly grouted in place;.the two monitor wells will be equipped with traffic rated, water tight utility manholes, including air tight locking cap with lock. The proposed locations are shown on Figure 1. Surface locations and well head elevations of each well will be determined by a licensed surveyor. Soil samples will be collected at five-foot intervals from the borings, and field screened for hydrocarbons. PHS-EHD will select which soil samples collected will be submitted to a California Department of Health Services approved laboratory for analysis. As referenced in the September 25, 1997 memo published by the Public Health Services San Joaquin County Environmental Health Services the soil sampling parameters for MW13-D will include Benzene, Toluene, Ethyl-Benzene, and Total Xylenes (BTEX) by EPA Method(8020); Total Petroleum Hydrocarbons Gasoline Range Organics (TPHg) by EPA Method (8015); D14sopropyl Ether (RIPE), Ethyl-Tertiary Butyl Ether (ETBE),Methyl-Tertiary Butyl Ether(MTBE), Tertiary-Amyl Methyl Ether(TAME), and Tertiary- Butanol by EPA Method 8260 (Oxygenates);Methanol and Ethanol.. All other soil samples will be analyze for MTBE and BTEX by EPA Method 8020. Additional samples may be submitted to confirm positive results. Groundwater samples will be collected from the monitor wells and submitted! to an appropriate California lab for analysis. The water sampling parameters will include BTEX(8021),TPHg(8015), and Oxygenates(8260). Drill cuttings, decon water,and purge water will be temporarily stored on location pending results of laboratory analyses. The drill cuttings and waste water will be transported and disposed of according to all local, state,and federal regulations. Upon completion of the work, and analysis of laboratory results and other data, a report will be prepared and submitted.to the County EHD for review& response.