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1 ,e <br /> =ENT BY:CLAYTON ENV I RClNMENTA 7-26-9e 4:17P[l 12-� <br /> ;# 5 <br /> a <br /> Cig on <br /> ,� t�1'tMr 7`MEh fh! <br /> 3.2 WELL DEVELOPMENT AND WATER SAMPLING <br /> Clayton surged and pumped the monitoring wells with a 4-inch submersible <br /> pump on April 4, 1990. This was done to stabilize the filter material and <br /> remove turbid water caused by drilling operations. We removed approximately <br /> 75 gallons (8 well volumes) from MW-1, 50 gallons (6.5 well volumes) from <br /> MW-2, and 70 gallons (7 well volumes) from M ,cM-2 and MW-3 <br /> recovered slowly and were purged dry several time . Tap wa r was added to <br /> these wells periodically to aid in development. M - overed quickly and <br /> did not require any additional water. <br /> We sample groun water from the monitoring wells on April b, 1990, in <br /> accordance with the protocols in Appendix B. MW-1 and MW-2 were purged <br /> of 5 well volumes each. MW-3 was purged dry twice and allowed to recover at <br /> least 80% before sampling. The field data sheets of the purging/sampling are <br /> included as Appendix E. <br /> '. wed( <br /> 3.3 HYDROGEOLOGY ( '5�� tI JK <br /> Soils underlying the site generally consist of clayey sands, sandy clays, an <br /> 7 <br /> gravelly sands with gravel being more abundant near the surface. Sandy soils <br /> are fairly permeable and allow water and contaminants to move readily through <br /> them, Appendix D contains the complete lithologic logs recorded while <br /> drilling. <br /> Derth to groundwater ranges from approximately 8 to 10 feet in the three <br /> wells. Well elevations were surveyed to datum sea level by Tronoff & <br /> Assoc;utes. From the well elevation data, groundwater flow direction was <br /> calcututed to be N3°W. or almost directly north. The groundwater gradient is <br /> 0.3 foot elevation drop per 100 feet distance. <br /> 4.0 LABOI&AXORY_ANALYSIS <br /> 4.1 PURPOSE AND SCOPE <br /> Analyses were selected to establish a baseline environmental condition at the <br /> site, and to assess soil and groundwater for possible contamination from the <br /> former UST, from USTs upgradient of the subject site, and from the possible <br /> previous use of pesticides onsite, The soil and groundwater samples were <br /> analyzed by the following methods; <br /> • EPA Method 5030/8015-8020, for gasoline fuel and the volatile <br /> hydrocarbons, benzene, toluene, ethylbenzene, and xylene. <br /> _ 3 - <br />