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. Three of the four wells were drilled to a depth of 20 feet bgs and were located on the adjacent property to the north The two-inch solid casing was connected at the bottom with fifteen feet of machine-slotted, schedule 40 PVC screen Therefore, there was five feet of solid casing with 15 feet of screen The top of the screened interval was set approximately two feet above the water level inside the borehole to account for potential water level fluctuations. The screen slot size for all monitoring wells is 0.010 inches One of the four wells was drilled on the subject property to a depth of 30 feet bgs in order to test deep water at the subject property Screened casing was placed on the bottom ten feet, and the upper twenty feet was solid casing A filter pack consisting of clean, washed, Monterey sand was placed from the bottom of the screen to about one foot above the screened interval Above the filter pack,the annular space was filled with a bentonite pellet seal measuring two feet in thickness The remainder of the annular space was backfilled with a cement grout mixture containing less than 5% bentonite powder Finally, a cement pad and traffic rated, water-tight, bolt-down surface flush mount vault box with locks, were set around the top of the PVC well casing 4.4 Groundwater Well Development and Sampling Procedures The monitoring well was developed six days following installation (February 14, . ,2002) The monitoring well was developed by surging the screen with a 2-Inch diameter surge block by hand methods, followed by pumping using a cleaned stainless steel Grondfos "Reade-Flow II" submersible pump All wells were purged until the pH, conductivity and temperature stabilized or until 1 at least five to ten well volumes were evacuated The pumping rate during the purging of all wells was approximately 1 gallon per minute (gpm) A total volume of approximately 45 gallons were discharged from all the wells All purged groundwater was collected in 55-gallon Department of Transportation (DOT) approved steel drums, sealed and temporarily stored on-site pending disposition based on the laboratory results One round of groundwater samples were collected from all ten on and off-site monitoring wells on February 27, 2002 Before initiating sampling activities, measurements of the depth to water and depth to bottom of the well casing were made to determine the well volume. A minimum of three well volumes were purged from each well before collecting groundwater samples All wells were purged using a submersible pump Avalon Environmental Consultants 9627-001 7 lues Truck Plaza 15600 S Harlan Road vtaY tS,2002 Lathrop California 6