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15 July 2004 <br /> AGE-NC Project No. 98-0540 <br /> Page 8 of 10 <br /> Following placement of the filter pack, the well will be surged to assist in settling the filter pack. <br /> Additional sand will be added if settling occurs. <br /> A nominal two-foot thick bentonite seal will be placed above the filter pack to minimize grout <br /> penetration into the screened section of the well. The bentonite seal will be formed by pouring <br /> bentonite chips into the annular space between the auger and the well casing and allowing them to <br /> settle on the filter pack. Bentonite chips will be hydrated using five gallons of water. The bentonite <br /> chips will be allowed to hydrate for a minimum of one-half hour prior to grouting. The remaining <br /> annular space above the bentonite seal will be filled to within one foot of the ground surface with <br /> a cement grout. The grout mixture will consist of Type I/II portland neat cement and not more than <br /> 6 gallons of water per 94-pound sack of cement. The grout will be placed by pouring through <br /> tremmie pipe. The EHD will be notified for grout inspection at least 48 hours prior to conducting <br /> grouting procedures. A typical monitoring well diagram is illustrated on Figure 3. <br /> 4.4. WELL DEVELOPMENT AND SURVEY <br /> Development will consist of a combination of bailing to remove the major portion of fine-grained <br /> sediment from inside the well, surging to flush out or draw in sediment from the filter pack, and <br /> additional bailing to finish the removal of sediment. Development activities will be continued until <br /> field parameter(pH,electrical conductivity,and temperature)readings have stabilized.Additionally, <br /> each well-head elevation will be surveyed by a licensed surveyor. <br /> 4.5. GROUNDWATER SAMPLING <br /> Ground water sample collection will be performed in accordance with the EHD's Recommended <br /> Groundwater Sampling Guidelines, dated 15 February 1995. <br /> 4.5.1. Static Water Level Measurements <br /> Before purging and sampling during ground water monitoring events, static water level will be <br /> measured using an electric water level indicator. Water level data will be recorded to the nearest <br /> 0.01 foot from a reference point marked on the top of the PVC well casing. Before and after each <br /> use, the measurement device will be rinsed with water. <br /> Advanced GeoEnvironmental,Inc. <br />