SITE INFORMATION AND CORRESPONDENCE

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f yrws�w.� �7 _ it f �FO�XENVlONMENTAL SERVICES, INC. ATTACHMENT B 8015 West Cliff Drive • Knoxville, TN 37919 • (61 5) 690-1996 i October 28, 1985 Mr. Kelly Williamson Kayo Oil Company 1221 E. Main Street Chattanooga, TN 37408 RE: Econo Gas Station 4325 E. Washington St. Stockton, CA 95205 Dear Mr. Williamson: The following is a report concerning the environmental assessment procedures that have been conducted at the Econo gas station located at 4325 E. Washington Street in Stockton, California by Fox Environmental Services, Inc. Beginning on June 22, 1985, groundwater monitoring was commenced, utilizing the three monitor wells, previously installed, that were to groundwater. These monitor wells are identified as MW6, MW#6 and MW#7, and a site drawing', is attached which indicates the location of each monitor well .. Between June 22, 1985 and July 15, 1985 grab sampling of these three wells produced no visible signs of hydrocarbons on the groundwater, but on July 26, 1985, a representative of Twining Laboratories was in the process of taking ground- water samples from the monitor wells, when he discovered raw product in MW#5. The product was bailed from MW#5 and on each subsequent monitoring visit raw product has been present in this monitor well . On September 19 and 20, 1985, four additional groundwater monitor wells were installed and are identified as MW#8, MW#9, MW#10 and MW#11 . These new wells have been placed into the groundwater to a depth sufficient to allow for seasonal groundwater fluctuations. The purpose of the these wells is to further define the area of contamination, and assess the groundwater conditions. Using a truck mounted mobile drill , equipped with a 7-inch continuous flight,, hollow-stem auger, bore holes were drilled to approximately 74 feet. A 2" PUC well screen with .020 slots, 50 feet in length, coupled with 20 feet of solid well tube and an 811 adapter with a threaded cap made up a finished well to a depth of 7018". The void around the well screen and tube was filled with pea gravel to within 161 feet of the ground surface. A bentonite seal was placed atop the pea gravel and the balance of the void was filled with a 20% ' bentonite 80o concrete mixture and a concrete Christy box with metal cover was used to finish the monitor wells at ground level . All four monitor wells were constructed alike, and you will find attached, the drill logs from each. boring which includes "as built" drawings of each well .