ARCHIVED REPORTS XR0006103 - Laserfiche WebLink

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. the source The auger and bit will be advanced to 3 feet above the desired sampling depth at which point a hydropunch tip and screen will be inserted through the hollow stem auger at the end of a hollow rod and driven three feet into the formation at the base of the test hole A groundwater sample will be collected from the screened tip with a mini bailer through the hollow rod The water sample will be decanted into 4 VOA vials with no airspace and preserved with 0 5 ml of HCL The water samples will be labeled and preserved as described below for the soil samples The hydropunch water samples will be analyzed by a certified laboratory for concentrations of TPH-G, BTEX, and MTBE using EPA method 8260B The results will be used to determine if future wells, if necessary, will need to be multiple depth-screened wells to define the groundwater contamination plume at distance from the source Once all samples have been obtained from the exploratory borings, the borings will be destroyed with neat cement containing 5% bentonite using tremae method for placement of the cement from bottom of boring to surface During placement of cement, all displaced fluids exiting the borings will be collected and pumped into 55-gallon drums that will be stored onsite for later disposal COMPLETION OF MONITOR WELLS MW6 AND MW7 Once the exploratory borings have been destroyed, the boreholes for MW6 and MW7 will be drilled to the 30-foot depth using 8-inch hollow stem augers No samples will be obtained because of the close proximity of each set of holes The boreholes will then be completed as monitor wells with and estimated 15 feet of machine slotted SCH 40 TriLock 2 inch diameter PVC screen (0 01) from estimated 15 feet bgs to the total depth of the well at 30 feet bgs Core examination from the exploratory boring nearest the well will determine the top of sand/clay interface placement of the top of screen The wells will be completed to surface with blank SCH 40 TriLock 2" diameter PVC The sand envelope will consist of 92/16 Lapis Lustre sand and will be positioned from the base of the well to 2 feet above the top of the slotted casing The sand envelope will be sealed on top with a 1-foot layer of hydrated bentonite pellets Cement (with less than 5% bentonite) will be used to seal the annular space from the top of the bentonite seal to surface A locking thermos cap will be used to seal the casing orifice A steel traffic box fitted with a well ID tag will be set in concrete to protect the exposed well casing COMPLETION OF RECOVERY WELL R1 The borehole will be completed as a monitor well with and estimated 23 feet of machine slotted SCH 40 TnLock 4 inch diameter PVC screen (0 02) from estimated 7 feet bgs to the total depth of the well at 30 feet bgs Core examination will determine the top of sand/clay interface placement of the top of screen The wells will be completed to surface with blank SCH 40 TriLock 4" diameter PVC The sand envelope will consist of #3 Lapis Lustre sand and will be positioned from the base of the well to 2 feet above the top of the slotted casing The sand envelope will be sealed on top with a 1-foot layer of hydrated bentonite pellets Cement (with less than 5% bentonite) will be used to seal the 6