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i 0 <br />Under the advisement of the field geologist and in accordance with the first version of <br />the approved EMP workplan, at each location, the driller was directed to advance the <br />borehole into the Corcoran Clay until water was encountered. A one -inch diameter <br />Schedule 40 PVC casing with 0.010 -inch slots was installed at this depth, and the <br />borehole was backfilled with No. 2/12 sand until the perforated section of the casing <br />was surrounded by the sand pack. The temporary wells were secured at the ground <br />surface using plywood weighted down with sand bags. <br />Temporary well construction information is summarized on the following table: <br />Well ID <br />Ground Surface <br />Elevation (msl) <br />Total Depth <br />(ft) <br />Screen Interval <br />MW -9 <br />296.92 <br />91.5 <br />70-90 <br />MW -10 <br />286.33 <br />76.5 <br />65-75 <br />MW -11 <br />283.27 <br />76.5 <br />64.5-74.5 <br />After the temporary wells were constructed, the water levels were allowed to <br />equilibrate for five days to allow measurement of static water levels. <br />4.2 Well Development <br />As a result of the presence of trace and measurable concentrations of VOCs in samples <br />from all three temporary wells, no permanent wells were constructed. Consequently, <br />the wells were not developed. Well development will be conducted in the permanent <br />monitoring wells following construction. <br />4.3 Aquifer Testing <br />Aquifer testing using bail down and recovery methods was a component of the <br />workplan. Since permanent wells were not constructed as part of the Phase I field work, <br />aquifer testing was not conducted. Aquifer testing will be conducted and the data <br />analyzed for each permanent monitoring well constructed for this EMP in accordance <br />with the methods outlined in the approved workplan. <br />4.4 Well Survey <br />The ground surface elevations adjacent to the temporary wells were surveyed by San <br />Joaquin County survey staff prior to drilling. Since permanent wells were not <br />constructed as part of this first phase of the EMP, no other surveying was conducted. <br />4.5 Borehole Abandonment <br />As a result of the presence of VOCs in samples from each of the temporary wells, the <br />boreholes were abandoned on December 19 and 20, 2011, in accordance with State of <br />EMP Report — Phase IGeo-Loic Page ■ 6 <br />I Corral Hollow Sanitary Landfill ASS O C I AT E SS <br />February 1, 2012 <br />