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0 KOPPEL-STOCKTON TERMINAL <br /> MONITORING WELL INSTALLATION WORK PLAN <br /> monitoring wells at the Cal Farm Supply facility.Monitoring well MW-6 was inadvertently <br /> destroyed in 1999. RWQCB has requested that a monitoring well be installed in the vicinity <br /> of Sonora Avenue north of the Koppel site to assess whether the extent of the nitrate plume <br /> at Koppel is adequately defined to the north(RWQCB,2004). <br /> Details regarding drilling,installation,development,and sampling of monitoring well <br /> KP-10S are provided in the following sections. Additional information will be collected and <br /> evaluated prior to the installation of KP-10S to support the conclusion that installation of a <br /> monitoring well is warranted in this area. This will include information on other potential <br /> sources of nitrogen in groundwater and groundwater levels at facilities adjacent to the <br /> Koppel Stockton Terminal. <br /> 2.0 Well Drilling Procedures <br /> The proposed location of monitoring well KP-10S is shown on Figure 1. The proposed <br /> location is south of the stormwater pond and north of Sonora Avenue.Access agreements <br /> will need to be obtained with the current property owner to facilitate installation of the well <br /> on the neighboring parcel. <br /> Well installation permits will be obtained from San Joaquin County prior to drilling.Utility <br /> clearance will be obtained by contacting Underground Services Alert prior to drilling. In <br /> addition,the existing site-specific health and safety plan will be reviewed prior to fieldwork <br /> and updated if necessary. <br /> A hollow stem auger rig will be used to drill the borehole for the monitoring well. Hollow- <br /> stem augers with a 10-inch inner diameter will be used to drill the boreholes. The borehole <br /> will be sampled and logged at 5-foot intervals.Soil cuttings will be collected in bins during <br /> drilling and spread on the surface of the northern planting location.Well development <br /> water will be used to irrigate the trees in the various planting areas. <br /> 3.0 Well Installation and Construction <br /> The proposed well construction schematic for KP-10S is shown on Figure 2. The monitoring <br /> well will be constructed with a flinch diameter 0.020-inch slot size polyvinyl chloride <br /> casing. The borehole will be drilled to a total depth of 22 feet below ground surface (bgs) <br /> and the screen placed from approximately 6 to 21 feet bgs.A 15-foot screen interval is <br /> proposed to include both the water table (groundwater depth has ranged from 6.0 to 14.4 <br /> feet below top of casing in nearby well KP-2) and the screen intervals of other shallow- <br /> screened monitoring wells.The screened interval may be modified based on the geology <br /> and depth to water observed in the field and the ground surface elevation relative to <br /> Koppel. The screen will be packed with No.3 sand from the bottom of the well to at least 3 <br /> feet above the screen.Approximately 1 foot of transition sand (No. 60 or equivalent)will be <br /> placed on top of the filter pack. Bentonite pellets will be used to form a seal at least 2 feet <br /> thick above the filter pack.The pellets will be hydrated and allowed to set for at least 20 <br /> minutes prior to grouting. <br /> The remaining annular space will be filled to the surface with cement-bentonite grout. Grout <br /> will be poured into the shallow borehole. The type of surface completion will be confirmed <br /> RDXWO184UREPORTS12004_MONRORINGWELLWP12004_MWELLWP.DOC 2 <br />