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Clayton <br /> E\%1Yp\VL\f it <br /> Cf}\7L'LZ1AEy <br /> Soil samples selected for laboratory analysis arc left in the brass liners, sealed with aluminum <br /> foil and plastic caps, taped for air tightness, -labeled, and immediate) <br /> ice chest chilled to less than 4°C. Labels contain the following infarmetion� site nainto a tudate <br /> led <br /> and time sampled, borehole number and depth, and the sampler's initials. The samples are <br /> transported under chain-of-custody to a state-certiGcd laboratory, 1'he laboratory analyzes <br /> soil samples within the prescribed holding time, storing them at temperatures below 4°C at all <br /> times. <br /> Pending results of laboratory analysis, excess drilling and sampling cuttings arelaced into <br /> address, and well number, and left at the site. <br /> Department of Transportation (DOT)-approved drums, labeled with the name of the ite, <br /> Uncontaminated soil may be disposed of by <br /> the client. Soil found to contain levels of contaminants above local or state actin levels wi)! <br /> client's request, we will assist with the disposal of contaminated soil. <br /> require that the client dispose of it in accordance with hazardous waste regulations. At the <br /> Boreholes are converted to monitoring wells by placing 2-inch or 4-inch diameter well casing <br /> with flush-threaded,joints and slotted screen into the borehole. Construction materials <br /> include polyvinyl chloride (PVC), stainless steel, or low carbor_ steel. The most suitable <br /> material for a particular installation will depend on the parameters to be monitored. All <br /> screens and casings used are is a contaminant-free condition when placed in the ground. No <br /> thread lubrication is used, other than teflon tape, for connecting the casing segments, <br /> --� W=!!s extend at least 10 feet into the upper saturated zone, but do not extend through au <br /> clay layers greater than 5 feet that are below the shallow water table. ]Factory-slotted casin <br /> Is used throughout and extends at least 2 feet above the permeable water-bearing zone. The <br /> top of the well is solid casing. The annular space of <br /> kiln-dried sand to a point at least Y foot above the s2 ht d screen. is backfilled <br /> seal above the falter washed, <br /> pack is formed by placing a 1- to 2-foot layer of bentonite pellets on can <br /> top of the sand. The <br /> bentonite.Pellets are moistened by pouring clean to water <br /> e.. and and P er down t <br /> `rP seal the annulus. A neat cement grout is placed above h obentonite seal and <br /> brought to the ground surface. <br /> VEJcII casings are protected from surface contamination, <br /> entry or tampering with water-tight locking caps on the well casings.a The caps are usually <br /> ed <br /> t surrounded by a concrete vault. Wells are clearly identified with x metal to or where the following information is recorded: well nu other device <br /> casing data including location of screened interval. tuber, depth to water, depth of well, <br /> The well seal in newly developed wells must set u for 48 <br /> Since developn;ent of the well can volatilize contaminants to 72 hours prior to development: <br /> for at least 48 to.;72 hours between development and the firstsPurging/sampling� emust also settle <br /> incident. <br /> All monitoring wells are initially developed to clean the well and stabilize sand, gravel, and <br /> disturbed aquifer materials around the screened internal perforations. W <br /> ' ells are developed <br /> i <br /> CFMHM <br /> r <br />