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11%� � <br /> underground storage tank and accessory pump unit . The EHD <br /> does not believe that sufficient data exists to 'make a "no <br /> contamination" finding. <br /> In order to accomplish these tasks, EHD believes that the <br /> local direction of flow of the water in the aquifers should <br /> be determined . The only sure way to do this is to measure <br /> precisely the standing fluid level in three or More nearby <br /> locations and to calculate the slope of the water table. <br /> Figures 1 , 2 and 3 show the slope of the underground water <br /> table on a regional basis; however, the data is not as <br /> complete in the local area as on most of the map. The EHD <br /> has required that this water table slope be determined. They <br /> have also required that the water in the on site water well <br /> be tested for contaminates and that its level be determined. <br /> If ora knew that the water in this well were in continuous <br /> hydr .uiic contact with that which will be .found in <br /> mor _toring wells, then only two monitoring wells would be <br /> needed to determine the water table slope because this slope <br /> can be determined. with 3 points . Inasmuch as this is not <br /> known, this report recommends that three monitoring wells be <br /> drilled as shown on Figure 4. Well leo. 1 is located in a <br /> down-slope water flow direction as deduced from the County <br /> maps and adjacent to Airport Way. Well No. 2. will be <br /> located within 10' of the end of the tank excavation, in a <br /> position where any leakage would likely be discovered. Well <br /> No . 3 will be located adjacent to Airport Way in a southerly <br /> direction; which possibly also could be the direction of <br /> water flow. If, upon testing the water level in the current <br /> water well , it is found that the level obtained fits the <br /> pattern of the three monitoring wells, then this data will <br /> also be utilized in determining the water table slope. <br /> Proposed Field Work <br /> Figure 5 is a type diagram for the proposed monitoring <br /> wells . Exact depths for each of the operations shown will <br /> not be known until the bore holes are drilled. <br /> A portable, truck mounted, hollow stem auger drilling unit <br /> will be used. A f0" nominal size Q.D. hole will be bored to <br /> an estimated 30 ' below ground level or whatever depth is <br /> needed to penetrate the water table at least 10' . 50 gallon <br /> drums with sealing covers will be on site for collection of <br /> all auger cuttings and any water bailed from the wells . The <br /> cuttings and any water collected, will be disposed of in a <br /> proper manner after the operation is concluded, the disposal <br /> methods will be dependent upon levels o f pollutants found . <br /> The wells will be cased with 4" screw-;;ointed PVC with the <br /> bottow 10 ' plu-a pre--perfcrated with . 02" slots , blank nosed <br /> on bottom. The well bore arotind tl,e perforated inf.erval will <br /> be packed with # 3 sand or the equivalent. as a filter <br /> ,medium . A 2 ' -4 ' bentonite c.;a} plttg will be placed allove the <br /> } s� <br /> per fcir iti 'Aie .1" pipk?—b1 .Z!' E'hole aliiiul s, to act as a <br /> i <br />