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i Kennedy/Jenks/Chilton Attachment A to Kennedy/Jenks/Chilton's letter to Mr. Charles Whitworth dated 14 July 1989 Page 4 The lower portion of the well consisted of two-inch (outside diameter) Schedule 40 PVC well screen with 0 020-inch machine cut slots. A PVC threaded end cap was attached to the bottom of the well screen to prevent formation fines, artificial filter pack sand, and other material from entering through the bottom of the well casing. The well screen was joined to two-inch (outside diameter) Schedule 40 PVC blank (non-slotted) casing which extended r approximately one foot above grade for monitoring well MW-1, MW-2, and MW-3. The PVC casing for MW-4 was terminated approximately three inches below grade A water-tight expansion-type well insert was placed inside the top of the PVC .� casing in all wells to help prevent water from entering the casing from the surface. A locking steel conductor casing was emplaced over the PVC well casing that 1 remained above ground after installation for wells MW-1, MW-2, and MW-3. The conductor casing extended approximately one foot above and 2-1/2 feet below grade. A lock was placed on the steel conductor casing to limit access Well MW-4 was completed using a water-tight traffic-rated well vault that was installed approximately 2 inches above grade to allow for surface water runoff. A graphic detail of the monitoring wells showing the surface completion is on the monitoring well construction logs presented in Attachment B. Drill cuttings were placed in certified D O.T. steel drums approved for the temporary storage and transport of hazardous materials. These drums were labeled with the boring number to indicate where the material originated. Each drum was also labeled to indicate drum contents and date of generation of material contained therein. Results of the laboratory analyses indicate that soil from boring B-1 and monitoring well MW-1 contain TPH and BXTE constituents. However, soil from 1 the remaining borings and monitoring wells did not contain concentrations l above method detection limits for TPH or BXTE Therefore, based on these results it is recommended that the soil from B-1 and MW-1 be stored on site and dealt with at the time the underground storage tank is removed (see recommendations section of this report) . The soil from B-2, MW-2, MW-3, and MW-4 can be disposed of onsite by emptying the barrels. This procedure should be confirmed with the San Joaquin Local Health District. MONITORING WELL DEVELOPMENT AND SAMPLING j Monitoring wells MW-1, MW-2, MW-3, and MW-4 were developed after construction . was completed to stabilize the artificial filter pack and to remove fine sediments from the adjacent soils and well annulus. Well development was performed by surging with a surge block and pumping using a diastolic pump. Surging was accomplished with a vented two-inch surge block raised and lowered 1