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23 February 2000 <br /> AGE-NC Project No 98-0533 <br /> Page 6 of 8 <br /> 4 2 MONITORING WELL INSTALLATION <br /> The monitoring well borings will be completed using hollow-stem auger drilling techniques <br /> Following completion of hollow-stem auger drilling activities, a PVC two-Inch diameter Schedule ' <br /> 40, slotted well screen (0 020-Inch) and well casing will be installed <br /> The casing, filter pack and sealing materials will be placed Into the borehole through the interior of <br /> the hollow-stem augers After Installing the well casing, filter pack material consisting of pre-washed <br /> #2112 Lonestar sand will be added from the bottom of the borehole to approximately two feet above <br /> the screened Interval Following placement of the filter pack, the well will be surged to assist In <br /> settling the filter pack Additional sand will be added If settling occurs <br /> A nominal two foot bentonite seal will be placed above the filter pack to minimize the potential of <br /> grout 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 procedures <br /> Following hydration of bentonite chips, the remaining annular space will be filled to the ground <br /> surface with a cement grout The grout mixture will consist of Type VII portland neat cement and <br /> not more than 6 gallons of water per 94-pound sack of cement The grout will be placed by pumping <br /> through tremmle pipe Grouting procedures will be Inspected by PHS-EHD personnel <br /> Following completion of the monitoring wells, well elevations and locations will be surveyed by a <br /> Callforma-licensed surveyor <br /> 43 WELL DEVELOPMENT <br /> Development will consist of a combination of balling and ground water pumping to remove the <br /> mayor portion of fine-grained sediment from Inside the well and surging to flush out or draw In <br /> sediment from the filter pack Development activities will be continued until field parameter (pH, <br /> electrical conductivity, and temperature) readings have stabilized <br /> 4 4 GROUNDWATER SAMPLING PROCEDURES <br /> Groundwater sample collection will be performed In accordance with pertinent applicable sampling <br /> protocols, details of which are presented below <br /> Advanced GeoEnvironmental,Inc <br />