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(BTEX) and Total Lead These compounds should cover the contaminants of interest to the PHS-EHD Microbiotic activity in the soil will also be documented Scone of Work Exploratory Soil Borings and Monitoring Well Installation Procedures One exploratory boring will be drilled with truck mounted hollow-stem auger, which has been cleaned prior to use The well will be installed by Spectrum Exploration of Stockton, CA under approved PHS-EHD permits The boring will be advanced to the uppermost water bearing stratum, and advanced ten to fifteen feet into the aquifer and terminated in the aquitard underlying that stratum or 125 feet, which ever is less Construction of wells is expected to require boring greater than 100 feet deep to encounter water A geologist will log the boreholes by collecting samples at 5-foot intervals, lithologic contacts of interest and areas of obvious contamination, using the Unified Soil Classification System For the purposes of this investigation soil samples will be collected for analysis at 15, 20, 25, 30, 40, 55, 60, 80, and 90 feet, and at the capillary fringe in precleaned brass liners contained in a split spoon sampler driven ahead of the drill bit (During the investigation, soil samples may be field screened with the use of a Hanby test kit and a combustible gas analyzer) Soil samples for chemical analysis will be removed, sealed with Teflon and endcaps, labeled, logged onto chain-of custody forms and packed on ice for transport to Priority Environmental Laboratory of Milpitis, CA (PEL), a state certified laboratory for analysis The sampler will be decontaminated prior to the next drive Drill cuttings will be stored on site, between plastic for characterization a later date Wright will dispose of the drill cuttings subsequent to laboratory results The monitoring well will be constructed using precleaned, threaded 4-inch diameter Sch 40 PVC well casing, screening the entire thickness of the aquifer, and a portion above the capillary fringe to allow observation for possible floating product Glues will not be used to construct well casing Final well design will depend upon subsurface conditions encountered The annulus between the casing and the borehole will be backfilled with 2/12 sand to about two feet above the screens A bentonite clay spacer about two feet thick will be placed above the sand pack, and cement grout will be pumped from above the bentonite to the surface using a tremie pipe A traffic rated access vault box with locking device will cap the well Monitoring Well Development and Sampling Procedures The well will be developed prior to sampling by surge and bailing to remove the drilling muck and borehole "smear" to improve hydraulic contact Completeness of development will be made on the clarity of water, amount of sand and silt entry based upon well performance and field judgement Sampling procedures will follow after development The well will be sampled by first sounding the well with an electronic probe to measure depth to water and check for presence of floating product if product is encountered, a bailer will be used to check and measure the apparent thickness All samples will be labeled, logged onto chain-of-custody and packed on ice for transport to PEL Well development and sampling water will be stored on-site in sealed drums Disposal of the water will be provided upon receipt of chemical data Proper disposal of the development water will be coordinated by Wright Environmental