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0 • <br /> Monitoring Well Installation Work Plan <br /> White Slough Water Pollution Control Facility ° <br /> A weighted survey tape or equivalent will be used to check depths and volume placed. A tremie <br /> pipe will be used to place cement slurry from the top of the bentonite slurry to the ground surface <br /> to seal the annulus. As indicated in Table 4-1, the EHD will be notified 24 hours in advance <br /> completing the well seal. <br /> Similar to the nearby well WSM-2, the PVC well casing will protrude approximately three feet <br /> above grade and be enclosed in a minimum 8-inch diameter steel protective outer casing <br /> embedded approximately three feet into the cement seal (Figure 4-1). The steel casing will be <br /> equipped with a locking lid. A 4-foot by 4-foot by 6-inch sloping concrete pad, equipped with <br /> four 42-inch traffic bollards, will also be constructed around the well. The monitoring well <br /> identification number(WSM-2R)will be painted on the outside of the steel protective casing. <br /> 4.2.3 Borehole Abandonment <br /> If applicable, any borings not converted into the monitoring well will be destroyed according to <br /> California Department of Water Resources and EHD guidelines. A grout mixture consisting of <br /> Type I or II Portland cement with three to five percent bentonite clay mixed with eight to ten <br /> gallons of potable water per sack of cement will be used. The grout mixture will be gravity fed <br /> into the borehole via a tremie pipe as the augers are pulled from the hole. After 24 hours, <br /> additional grout will be placed in the boreholes if settlement has occurred. Borehole <br /> abandonment will be documented on the boring log. As indicated in Table 4-1, the EHD will be <br /> notified 24 hours in advance of borehole abandonment. <br /> 4.3 Monitoring Well Development <br /> At least 24 hours following construction, the well will be developed by alternating bailing with a <br /> close-fitting bailer and surging with a vented surge block. After any sediment has been removed <br /> from the bottom of the well casing, development will continue by pumping with a <br /> decontaminated submersible pump. The well development will continue until pH, temperature, <br /> and specific conductance measurements have stabilized and the water is clear and colorless, <br /> if possible. <br /> Stabilization shall be defined as agreement between the last two sets of readings within plus or <br /> minus 0.1 pH units, plus or minus 1.VC, and plus or minus 10 percent of full scale reading for <br /> specific conductivity. If parameters have not stabilized during the removal of three cased well <br /> volumes, then a maximum of five well volumes will be removed. A record of the well <br /> development will be maintained using the Water Quality Stabilization Record included in <br /> Appendix A. <br /> WEST YOST ASSOCIATES 7 City of Lodi <br /> September 2014 Monitoring Well Installation Work Plan <br /> w\c\213\06-14-31\wp\WP\083014_1 RWP <br />