Laserfiche WebLink
15 January 1998 <br /> AGE-NC Project No 96-0254 <br /> Page 13 of 16 <br /> Following completion of the soil boring for PMW1, a 2-inch diameter Schedule 40 PVC 0 02-Inch <br /> slotted well screen and casing will be Installed A 5-foot section of well screen will be Installed from <br /> a depth of approximately 25 feet to 30 feet bsg, depending on llthologles encountered with PHS- <br /> EHD approval The casing, filter pack and well sealing materials will be placed Into the borehole <br /> through the Interior of the hollow-stem augers After Installing the well casing, filter pack material <br /> consisting of pre-washed #3 Lonestar sand will be added from the bottom of the borehole to <br /> approximately two feet above the lower screened Interval Following placement of the filter pack, <br /> the well will be surged to assist In settling the filter pack Additional sand will be added If settling <br /> occurs A nominal 8-foot bentonite seal will be placed above the filter pack Presumably, the <br /> bentonite chips will be hydrated by the surrounding native ground water <br /> Next, In the same boring, a second 2-Inch diameter Schedule 40 PVC 0 010-Inch slotted well screen <br /> and casing will be Installed A 10-foot section of well screen will be Installed from a depth of 5 feet <br /> to 15 feet bsg After Installing the upper well casing, filter pack material consisting of pre-washed <br /> #3 Lonestar sand will be added from the upper portion of the lower bentom to seal to approximately <br /> two feet above the upper screened Interval Following placement of the filter pack, the well will be <br /> surged to assist In settling the filter pack Additional sand will be added If settling occurs A nominal <br /> 2-foot bentonite seal will be placed above the filter pack to minimize the potential of grout <br /> penetration into the screened section of the well The bentonite seal will be formed by pouring <br /> bentonite chips Into the annulus and allowing them to settle on the filter pack Bentonite chips will <br /> be hydrated using five gallons of water The bentonite chips will be allowed to hydrate for a <br /> minimum of one-half hour prior to grouting <br /> Following completion of the soil boring for PMW2, a 2-Inch diameter Schedule 40 PVC 0 020-Inch <br /> slotted well screen and casing will be Installed A 5-foot section of well screen will be Installed from <br /> a depth of 35 feet to 40 feet bsg,depending on the lrthologles encountered,with PHS-EHD approval <br /> The casing,filter pack and well sealing materials will be placed into the borehole through the Interior <br /> of the hollow-stem augers After Installing the well casing, filter pack material consisting of pre- <br /> washed 93 Lonestar sand will be added from the bottom of the borehole to approximately two feet <br /> above the screened interval Following placement of the filter pack, the well will be surged to assist <br /> In settling the filter pack Additional sand will be added If settling occurs A nominal two-foot <br /> bentonite seal will be placed above the filter pack to minimize the potential of grout penetration into <br /> the screened section of the well The bentonite seal will be formed by pouring bentonite chips Into <br /> the annulus and allowing them to settle on the filter pack Bentonite chips will be hydrated using five <br /> gallons of water The bentonite chips will be allowed to hydrate for a minimum of one-half hour <br /> prior to grouting <br /> The remaining annular spaces will be filled to the ground surface with a cement grout The grout <br /> mixture will consist of Type I/II portland neat cement and not more than 10 gallons of water per <br /> Advanced GeoEnvironmental, Inc <br />