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1 1444 MARIPOSA ROAD WKA No 2938 05 August 26, 1999 ' Page 13 A total of eleven soil samples were obtained from the borings at depths ranging from 47 to 95 feet bsg The soil samples were obtained using a modified California sampler equipped with clean, two-inch diameter, six-inch long brass tubes The brass tubes were sealed with Teflon® sheets and plastic end caps to reduce volatile hydrocarbon loss The samples were screened to the field with a photoionization detector(PID)to evaluate potential hydrocarbon ' content The soil samples were placed in an ice chest containing ice, and submitted under chain-of-custody to a California-certified laboratory for chemical analysis of TPH as gasoline using modified EPA Method 8015, BTEX using EPA Method 8020, and MTBE, DIPE, ' ETBE, TAME, and Tert-Butanol using EPA Method 8260B ' Soil borings MW4 through MW7 were converted into monitoring wells (MW4 through MW7) The wells were constructed using two-inch diameter, flush-jointed, Schedule 40 PVC casing, 0 02- inch slotted casing was used for the screened interval The wells are screened from approximately 40 to 70 feet bsg Number 3 sand was placed as a filter pack in the well annulus The filter pack extends from the bottom of the screened interval to approximately three feet above the top of the screened interval of each well A two-foot thick bentonite seal was placed in the well annulus above the filter pack A grout seal consisting of a Portland Cement and bentonite slurry was placed in the well annulus above the bentonite seal Each well was completed with a locking well cap and a flush-mounted, traffic-rated well cover Well construction details are shown on Plate 11 On June 15, 1999 the wells were developed using an electric submersible pump Approximately five well volumes of water was removed from each well or until stabilized pH, temperature and conductivity readings were attained Approximately 24 hours after development,monitoring ' wells MW through MW7 were purged of at least three well volumes of water or until relatively free of sediment and/or until stabilized pH, temperature and conductivity readings were attained ' Prior to purging and sampling, a water level measurements were recorded and the wells were checked for the presence of free floating product by using a new clear, disposable polyethylene ' bailer Water removed from the wells during development and purging activities were placed in a labeled 55-gallon drum and stored on site The location of the new wells and the top of casing elevations along with the existing wells were surveyed on July 2, 1999 to the nearest 0 01 foot • with respect to mean sea level (MSL) WALLACE•KUHL Re ycled pipe Er ASSOCIATES INC