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07 October 2002 <br /> AGE-NC Project No 01-0827 <br /> Page 5 of 7 <br /> 41 SOIL SAMPLING <br /> Proposed monitoring well boring will be completed using a CME-75 truck-mounted,hollow stemdrill <br /> rig equipped with 8 25-inch diameter hollow-stem augers Relatively undisturbed soil samples will <br /> be collected ahead of the drill bit at five-foot intervals beginning at five feet bsg in each of the bol Ings <br /> using a California modified split-spoon sampler fitted with 2-inch diameter, 6-inch long brass sleeves <br /> Upon removal from the sampler, the exposed ends of a selected sleeve will be covered with Teflon <br /> sheets, capped and sealed with tape Soil sample duplicates will be visually classified by an AGE <br /> geologist in accordance with the Unified Soil Classification System (USCS) Additionally, soil <br /> samples will be field-sci eened for the presence of volatile of ganic compounds using an OVM <br /> Following sample collection, each pi eserved sample sleeve will be labeled with the boi ing location, <br /> depth, time, date and sampler's initials Appi opriately sealed and labeled samples will be placed in a <br /> chilled containei under ice and transported undei chain-of-custody to a DHS-certified laboratory for <br /> analysis <br /> 4 2 MONITORING WELL INSTALLATION <br /> Following completion of drilling of the monitoring well boi ing, a 2-inch diameter Schedule 40 PVC <br /> 0 020-inch slotted well screen and casing will be Installed A 5-foot section of well sci een will be <br /> installed in the boring from a depth of 65 feet to 70 feet bsg <br /> The well casing, filtei pack and sealing materials N Ill be placed into the boi chole through the interior <br /> of the hollow-stem augers Aftei installing the well casing, filtei pack material consisting of <br /> pi e-washed #3 Lonestar sand will be added from the bottom of the boi ehole to approximately one <br /> foot above the screened interval Following placement of the filter pack, the well will be surged to <br /> assist in settling the filtei pack Additional sand will be added if settling occurs <br /> A nominal two-foot thick or, foi the depth discrete well, a foui-foot thick bentonite seal will be <br /> placed above the filtei pack to minimize grout penetration into the sci eened section of the well The <br /> bentonite seal will be formed by pouring bentonite chips (or pellets) into the annular space between <br /> the auger and the well casing and allowing them to settle on the filter pack Bentonite chips will be <br /> hydrated using five gallons of water The bentonite chips will be allowed to hydrate for a mrmmum <br /> of one-half houi prior to grouting <br /> The i emaining annular space above the bentonite seal will be filled to within one foot of the ground <br /> surface with a cement grout The grout mixture will consist of Type IIII portland neat cement and not <br /> more than 6 gallons of water pet 94-pound sack of cement The grout will be placed by pumping <br /> . through tremie pipe The EHD will be notified for grout inspection at least 48 hours prior to <br /> conducting grouting pt ocedui es A typical monitoring well diagi am is illustrated on Figure 3 <br /> Advanced GecEnvummenlal,InL <br />