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Gradient Calculation <br /> i <br /> Prior to purging the wells and collecting groundwater samples, the <br /> depth to groundwater was measured. Because the casing for MW-3 was <br /> repaired, a new survey of the wells was completed using the cement <br /> foundation on the northeastern corner of the barn as a benchmark of <br /> 15 feet. Field notes are contained in Appendix A. <br /> The depth to groundwater was measured in the three wells, by an <br /> electronic probe, from the mark located on the top of each casing. <br /> The resulting data is shown in Table 2. <br /> TABLE 2 <br /> Groundwater Elevation measurements - December 6, 1995 in Feet <br /> Well ID Well Elevation Depth to Water Groundwater <br /> Elevation <br /> MW-1 17. 07 11. 50 5.57 <br /> MW-2 17.84 12 .23 5.61 <br /> MW-3 16.72 11.08 5.64 <br /> The calculated gradient is S430W or 2270 at 0.001 ft/ft. <br /> Groundwater Sampling <br /> The wells were purged by pumping and collecting the purged <br /> groundwater in 55-gallon drums labeled awaiting analysis. Each of <br /> the wells was pumped to dryness. The wells were slow in recovering <br /> as they were in the two previous sampling events. This phenomenon <br /> of slow recovery is most likely caused by the silty clay soil at <br /> the screened section of the wells. Well data sheets are contained <br /> in Appendix A. <br /> Groundwater samples, one from each well, was collected by a clean <br /> dedicated bailer, placed in two 40 ml VOAs with Teflon septa, <br /> labeled, held in a cooled (4 Degrees C) ice chest and transported <br /> to a State Certified Laboratory, under COC documentation, for <br /> analyses. The samples from MW-1, MW-2 and MW-3 were collected on <br /> December 6, 1995. <br /> The groundwater pumped from each of the monitoring wells had a <br /> slight hydrocarbon odor. The groundwater from MW-2 and MW-3 had a <br /> slight sheen. <br /> • 4 <br />