Laserfiche WebLink
, p <br /> 0 F�1:1 14W] GROUNDWATER <br /> E1111:1 <br /> TECHNOLOGY, INC. 1401 Halyard Dnve Suite 140,West Sacramento,CA 95691,(916)372-4700 <br /> FAX(916)372-8781 <br /> February 10, 1992 Project No 02320 2241 <br /> Mr Clint B Rogers <br /> Chevron U S A , Inc <br /> 2410 Camino Ramon <br /> San Ramon, CA 94583-0804 <br /> RE WORK PLAN ADDENDUM NO 2 <br /> CHEVRON SERVICE STATION NO 9-4275 <br /> 2905 WEST BENJAMIN HOLT DRIVE <br /> STOCKTON, CALIFORNIA <br /> Dear Mr Rogers <br /> Groundwater Technology, Inc presents this addendum to the Work Plan Addendum No 1 (dated <br /> January 27, 1 992) Work Plan for Additional Monitoring Well Installation, Chevron Service Station <br /> No 9-4275, 2905 W Benjamin Holt Drive, Stockton, California, dated June 1990 (Attachment <br /> Al Addendum No 1 to the original work plan revised the location, and construction of two <br /> groundwater monitoring wells, and the soil sampling and frequency for the site The following <br /> items within the work plan are amended in this (No 2) addendum <br /> ■ The location of one of the monitoring wells <br /> ■ The drilling of an additional soil boring and installation of a vapor extraction well <br /> for additional soil data and for potential future soil vapor extraction data <br /> MONITORING WELL LOCATIONS <br /> Two groundwater monitoring wells will be installed to investigate the extent of dissolved-gasoline <br /> hydrocarbons Due to the difficulty in expediently obtaining a Caltrans encroachment permit, the <br /> proposed monitoring well location west of the site was moved onsite (Figure 1) <br /> VAPOR EXTRACTION WELL CONSTRUCTION <br /> The vapor extraction well will be installed within a soil boring which will be advanced to <br /> approximately 20 feet below grade, using a truck-mounted drill rig equipped with 8 5-inch outside- <br /> diameter (0 D ) hollow-stem augers Undisturbed soil samples will be collected at five foot intervals <br /> using a 2 5-inch-0 D by 2-foot-long split-spoon core barrel The vapor extraction well will be <br /> constructed of 15 feet of 2-inch-diameter schedule 40 polyvinyl chloride (PVC) casing and 5 feet <br /> of 0 020-inch-slotted well screen A filter pack of No 2/12 lapis lustre sand will be placed around <br /> the well from the bottom to approximately one foot above the top of the well screen A seal <br /> Offices throughout the US,Canada and Overseas <br />