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r 1 Monitoring Well Installation Report Speedy Mart,8200 N Highway 99 • Page 4 of 8 Discrete Groundwater Sampling Discrete groundwater samples were collected from borings SB4 and SBS, as well as the pilot hole for MWI A Simulprobe groundwater sampling device was used to collect a discrete groundwater sample from MW1 at approximately 95 feet bgs A hydropunch sampling tool was used to collect groundwater samples from bonngs SB4 and SB5 at depths of 61 and 64 feet bgs, respectively Groundwater samples were collected into 40-mil glass vials preserved with hydrochloric acid The vials were sealed with plastic caps with Teflon-lined septa and immediately placed in an iced cooler Samples were transported under chain of custody to Argon Laboratories and analyzed for TPHg, BTEX, and gasoline oxygenate additives Well Construction Borings MW2 through MW4 were converted into monitoring wells Well MWl was installed to a depth of approximately 80 feet bgs in a separate boring drilled approximately two feet south of the initial pilot hole Well MW1, located in the immediate vicinity of the former USTs, was constructed utilizing 4-inch diameter schedule 40 PVC casing, and wells MW2, MW3, and MW4 were constructed with 2-inch diameter casing The well screens (0 020-inch slots) extended from the bottom of the borings to approximately five feet above the static water level (approximately 60 to 64 feet bgs) A 2- foot thick layer of bentonite pellets was placed above the filter pack in each well and hydrated to form a seal around the well, and the remaining annular space was grouted with cement grout to the ground surface Each well casing was capped with a water-tight, locking cap and covered with a traffic-rated well box Well completion details and soil boring logs are included in Attachment A Well Development and Groundwater Sampling On October 12 and 13, 1999, the newly installed wells were developed by surging and bailing until turbidity was minimized At least ten casing volumes were removed from each well Temperature, pH, and electrical conductivity were measured during the well development process Purge water was placed into DOT approved 55-gallon drums pending disposal After groundwater levels recovered to at least 80%, depth to water was measured and groundwater samples were collected from each well Groundwater samples were submitted to Argon Laboratory for analysts of TPHg and BTEX, and gasoline oxygenate additives Groundwater monitoring data and well development logs are included in Attachment B Waste Disposal Approximately 10 cubic yards tons of soil waste generated from drilling were transported on January . 11, 2000 by Deltech Geotechnical and RHT Trucking to the Forward Landfill in Manteca, California for disposal Approximately 375 gallons of ansate and well development water were removed from groundze%tuieUurglweiirpt doe