Laserfiche WebLink
�V <br /> s` <br /> Borings will be advanced to depths at which contaminants do not appear to be present, <br /> based upon visual and soil vapor field data. Wright will attempt to gain two consecutive <br /> none detected samples to define the lower contaminant penetration, which based upon the <br /> previous work, was at about the 20-to 25-foot depth. <br /> The initial boreholes will be drilled with truck mounted direct push drilling equipment. <br /> All drilling equipment and.sampling tools will be cleaned prior to arriving, between <br /> driving samples and before leaving the site. The drill rods will be advanced to the desired <br /> sampling depth interval, and a drive split spoon sampler will be driven ahead of the drill <br /> bit. The sampler will be retrieved and dissembled, and any soil filled acetate liners <br /> retained for chemical analysis, will be sealed with Teflon® paper or foil and plastic end <br /> caps. Each sample will be labeled, logged onto chain-of-custody forms and place in a <br /> chilled ice chest on crushed ice. Drill cuttings will be drummed and left on-site. <br /> The boreholes will be logged using the Unified Soil Classification System under the <br /> supervision of a registered geologist. Additional lithologic information may be collected <br /> to describe the subsurface geology. Soil samples will be field screened for presence of <br /> contaminants by checking for presence of odor and staining, and a photoionization meter <br /> will be used for soil field vapor measurement use. This reconnaissance field vapor data <br /> will be used to select soil samples for. analysis. andto record potential contaminant <br /> presence. Soil samples will be collected at no greater that five-foot vertical intervals, <br /> with additional samples collected at intervals of obvious contamination and at <br /> stratigraphic features of interest using field discretion. <br /> Reconnaissance Groundwater Sampling <br /> Groundwater from each borehole will be sampled using push or drill rods as temporary <br /> casing in the uppermost aquifer. Depth to groundwater measurements will be made to the <br /> nearest one-one hundredth of one foot from existingrade and also checked for g o the <br /> presence of separate phase product. Please note that in uncased boreholes water levels <br /> may not equilibrate due to the length of time open. Each groundwater sample will be <br /> carefully collected with a clean disposable bailer and poured into the appropriate <br /> laboratory prepared container with minimum cavitation and headspace. Each water <br /> sample will be labeled, logged onto a chain-of-custody form, and placed in a chilled ice <br /> chest on crushed ice. <br /> Data Review for Monitoring Well Placement <br /> Once the chemical data is reviewed locations for monitoring wells, if needed, will be <br /> selected. These well locations will be sent to the PHS EHD representative for comment <br /> and to secure well permits, prior to installation. The field data from the assessment will <br /> be used to select the number of wells (3 or more) as needed for adequate site coverage. If <br /> wells are installed the following procedures would be used. <br /> Page 2 <br />