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Mr. Ray Borges <br /> December 14, 1990 <br /> Page 2 <br /> Central Valley Region of the Regional Water Quality Control <br /> Board (RWQCB) . The well was subsequently damaged and buried, <br /> probably by grading equipment used to maintain the access road <br /> along the north side of the irrigation canal. When the <br /> wellhead was relocated and excavated (from under about <br /> 1-1/2 feet of fill ) in September 1990, the locking steel outer <br /> protective casing and the PVC well casing were damaged and soil <br /> material had fallen into the well blocking the casing at a <br /> depth of 31 feet. The casing blockage was cleared and a water <br /> level measurement on November 20, 1990, indicated the well was <br /> dry. <br /> The proposed plan for destruction of the well is designed to <br /> satisfy the San Joaquin County requirements you outlined during <br /> our November 8, 1990, conversation and applicable requirements <br /> of the State of California. All of the well destruction <br /> activities described herein will be supervised by a California <br /> registered geologist. Destruction of well BC8 will be <br /> accomplished by completely filling the 2-inch casing with a <br /> grout mixture consisting of neat cement with 5-percent <br /> bentonite and clean water. Due to the absence of water in the <br /> well and the small diameter of the casing, the grout mix will <br /> be slowly poured down the well from ground surface. The volume <br /> of grout will be monitored to insure that a minimum of one <br /> casing volume (approximately 7. 1 gallons or 0.95 cubic feet ) is <br /> added to the well. <br /> When the casing has been completely filled with grout, the top <br /> of the well will be sealed and the casing will be pressurized <br /> to a maximum of 10 pounds per square inch using compressed air <br /> or nitrogen gas, forcing some of the grout out through the <br /> slots into the filter material . The pressure will be <br /> maintained for approximately 15 minutes. After an initial <br /> 15-minute interval , the pressure will be released, the well cap <br /> will be removed, and the grout level in the casing will be <br /> checked. If the grout level has dropped, additional grout will <br /> be added. The well will then be repressurized and the pressure <br /> will be maintained for another 30 minutes . <br /> Following the 30-minute interval, the well cap will then be <br /> removed and additional grout will be added if necessary, to <br /> bring the grout level back up to a point just above the top of <br /> the casing. After the grout has cured for several hours, the <br /> 1-1/1 foot deep excavation dug to relocate the buried well will <br /> be backfilled to ground surface with native soil material. <br /> A brief letter summarizing the well destruction activities will <br /> be prepared following completion of the work. Copies of that <br /> letter will be transmitted to your office and to Ms. Pat Leary <br /> Brown and Caldwell <br /> Consultants <br />