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Geological Technics Inc. Page 4 <br /> C&B Equipment <br /> Monitoring Well Installation Report <br /> Project No. 336.2 <br /> November 13,1995 <br /> The three 2 inch diameter wells were constructed of flush threaded schedule 40 PVC <br /> casing with 15 feet of 0.020 inch perforations. A #3 Monterey sand surrounded and <br /> extended one foot above the perforations. The wells were surged using a surge <br /> block to settle the filter pack before the granular bentonite transition seal was <br /> r.� installed and hydrated. The annulus was sealed using a neat cement grout installed <br /> with a slurry pump and tremie pipe. The wells were completed with a locking <br /> water tight cap enclosed in a flush mounted water tight traffic box. The annular seal <br /> was completed integral with the installation of the well box. <br /> On July 31, 1995 the elevation of each well's top of casing measuring point was <br /> 3 surveyed by Mr. Duane C_ Kimball, licensed land surveyor, and referenced to an <br /> ==' arbitrary 100 ft datum (Appendix D-Field Logs). An as-built monitoring well <br /> construction schematic is attached as Figure 5. <br /> After the well sealing materials had set (for a period greater than 24 hours), the well <br /> was developed (using mechanical surging and pumping methods) until a clear <br /> stream of water was obtained. All development water was containerized in 55 <br /> gallon DOT approved containers and stored on site. <br /> The following table lists the well construction details. <br /> Monitoring Well Construction Details <br /> { Well Date of Screened #3 Sand Bentonite Cement <br /> Installation Interval Filter Pack Annular Grout <br /> 0.020" (ft) (ft) Seal (ft) (ft) <br /> MW-1 07/25/95 5-20 4-20 2-4 0-2 <br /> MW-2 07/25/95 5-20 4-20 2-4 0-2 <br /> MW-3107/25/95 -20 5 4-20 2-4 0-2 <br /> 2.4 Groundwater Monitoring <br /> Two rounds of groundwater monitoring were performed according to protocol <br /> established in the Geological Technics Inc. June 15, 1995 Monitoring Well Installation <br /> and Groundwater Monitoring Work Plan. The following is the procedure used for <br /> -- sampling groundwater from the monitoring wells: <br /> Before sampling is attempted the well was sounded for depth to water and then a <br /> clear disposable bailer was used to determine if floating product is present. The well <br /> was purged of at least 3 well volumes of stagnant water using either a submersible <br /> J pump or a stainless steel bailer. Purging continued until the temperature, <br /> conductivity, and pH of the groundwater has stabilized (<10% variation between <br /> three readings) indicating that formation water representative of aquifer conditions <br />