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1 • • Kennedy/Jenks Consultants • Select a state-certified laboratory to conduct laboratory analytical services. 8.3.2 Installation and Development of Monitoring Wells Following completion of the pre-field activities, a licensed drilling subcontractor will advance the subsurface borings and install the monitoring wells at the selected locations.The soil borings will be drilled using a truck-mounted drill rig equipped with 8-inch hollow stem augers or equipped with an air-rotary system capable of drilling an 8-inch diameter borehole.The borings will be advanced approximately 10 to 15 feet into the groundwater.Soil samples for logging will be collected every five feet using a split spoon sampler and the soil will be lithologically logged using the USCS (ASTM D-2488-93)system under the direction of a California Professional Geologist who has expertise in lithologic well logging. Field documentation will include the completion of boring logs that record the soil encountered during drilling of each borehole,soil sampling intervals, depth and thickness of the saturated zones, and well construction details. Following completion of the wells,well construction logs will be prepared. General procedures for sampling and logging are presented in Kennedy/Jenks'Standard Operating Guideline— Borehole Logging(Appendix G). The monitoring wells will be constructed with 2-inch diameter Schedule 40 polyvinyl chloride (PVC)flush-threaded casing. For the screened interval, 0.010-inch slots or other appropriate slot size for the lithologies encountered will be selected based upon the lithologic logs from the soil borings.The remainder of each well above the screened section will consist of flush-threaded, 2-inch diameter, Schedule 40 PVC blank casing.The wells will have 20-foot screened sections. A continuous filter pack will be placed in the annular space between the screened section and the wall of the boring.The filter pack will consist of washed, packaged sand that is sized accordingly for the well screen slot size selected (#2/12 or equivalent for 0.010-inch slots).The filter pack will extend upwards from the bottom of the boring to one to two feet above the screened section.All wells will be pre-developed after the filter pack is installed,and prior to the bentonite seal being installed. A 2-to 5-foot layer of protective bentonite clay pellets will be placed above the filter pack to minimize downward migration of the grout seal into the filter pack.A cementIbentonite grout will be placed so as to extend continuously from the top of the bentonite pellet layer to less than one foot below grade. In accordance with local regulations, a San Joaquin County representative will be onsite to observe or approve of the grouting.A locking expansion cap and well-housing enclosure will be installed to control access to the well opening. Wells located in unpaved areas near the land application areas will be completed abovegrade and furnished with a protective, locking steel casing.Wells located in paved or trafficked areas will be completed approximately at grade and will be fumished with a traffic-rated monument set in a sloping concrete apron to facilitate surface drainage away from the well. After waiting a minimum of 48 hours to allow curing of the grout and concrete,the monitoring wells will be developed by surging, bailing,and pumping until the water removed from the wells is sediment-free or until no further improvement in water quality is observed.The wells will be allowed to recover for a minimum of 72 hours following well development, prior to monitoring and sampling. General procedures for well construction are presented in Kennedy/Jenks' Standard Operating Guideline—Well Construction and Development(Appendix H), and a schematic well construction detail is presented on Figure 21. Paye 28 Phase I Groundwater Investigation and Work Plan for Phase 11 Investigation Musco Family Olive Company, Tracy, California RW9o9VYmYdGN]Olw.w,�vumoMlw.eprchkEeWftiryha.l P.'kwdRiSM1�.GkwdW OhWddx