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y <br /> ELcploratory Boring and Logging <br /> Four exploratory borings will be drilled at the locations shown on Figure 1. Drilling and well <br /> installation permits will be secured from PHS EHD, and a utility clearance will be performed prior <br /> to doing the fieldwork. The boreholes will be drilled with truck mounted mud rotary drilling <br /> equipment. Logging will use both a continuous chip log and discrete soil/sediment from intervals <br /> of interest. The drill bit will be advanced collecting continuous cores of soil in each borehole. <br /> The sampler will then be retrieved and dissembled,.and the'soil filled acetate liner will be sealed <br /> with Teflon paper or foil and plastic end caps, labeled, logged onto chain-of-custody forms and <br /> place in a chilled ice chest. Soil sample intervals retained for chemical or physical analysis will be <br /> cut from the liners or sealed in metal sampling tubes. <br /> The boreholes will be logged using the Unified Soil Classification System under the supervision of <br /> a registered geologist. Additional Iithologic information will be collected to describe the <br /> subsurface geology. The samples will be collected at five-foot intervals, at intervals of suspect <br /> contamination and at stratigraphic features of interest at the geologist discretion. Upon <br /> completion of the borehole drilling and collection of water :samples, the boreholes will be <br /> I, <br /> backfilled with grout, placed from the bottom to top of the borehole. <br /> Soil/sediment samples will be collected in the aquifer strata for performing physical testing. The <br /> physical testing is anticipated for moisture content, bulk, density and hydraulic conductivity. <br /> These samples will be collected using coring tubes to collect the material during borehole drilling <br /> for the wells. One physical sample will be taken from one well in the 58-63 foot interval and one <br /> sample from the 114-119 foot interval. <br /> Drilling Fluid Mud Decontamination Water and Well Water':Storage and Dispos l <br /> The drilling mud will be placed into closed top barrels and stored on-site. The drilling mud fluid, <br /> circulation water and well development water will.be marked in drums. Monitoring well purge <br /> water will also be stored in closed top barrels and labeled and stored on-site. Once results are <br /> received for the drilling fluid mud, decontamination water'and purge water, these fluids will be <br /> properly disposed off-site. <br /> Monitoring Well Installation <br /> Four monitoring wells will be installed for long term plume monitoring. Three wells will be cased <br /> with two-inch diameter Sch. 40 PVC casing and one well with four-inch diameter casing, threaded <br /> together; glues will not be used. The slotted interval will .use a 0.020-inch slot for all wells and <br /> the annular space around the slots will be backfilled with a-2/12-size sand. Previous experience <br /> has shown this to be a reliable well design in fine grained and stratified depositional environments. <br /> Final well design will be modified to the site-specific conditions encountered in the borehole <br /> during drilling. ' <br /> t <br /> Page 5 of 5 <br /> t <br /> I <br />