WORK PLANS - Laserfiche WebLink

Home Browse Search

04 December 2007 AGE-NC Project No. 99-0592 Page 6 of 7 settling the filter pack; additional sand will be added if settling occurs. A nominal 2- to 3-foot bentonite chip or bentonite pellet seal will be placed above the filter pack to minimize the potential for grout penetration into the screened section of the wells. The bentonite seal will be formed by pouring bentonite chips/pellets into the annulus and allowing them to settle on the filter pack. The bentonite will be allowed to hydrate for a minimum of%2-hour prior to grouting. The remaining annular space will be filled to within 1 foot of the ground surface with a cement grout. The grout mixture will consist of Type 1/II portland neat cement and not more than 3 gallons of water per 47-pound sack of cement. A grouting inspection will be scheduled with EHD personnel. Following completion of the monitoring wells,well elevations and locations will be surveyed by a California-licensed surveyor. 3.1.3. Well Development Development of the proposed wells will consist of a combination of bailing with a stainless steel bailer to remove the major portion of fine-grained sediment from inside the well, surging to flush out or draw in sediment from the filter pack,and additional ground water evacuation with a Waterra inertia pump to finish the removal of fine-grained sediment. Developmental purging activities will be continued until field parameters(pH,electrical conductivity,and temperature)have stabilized and purged water is visually sediment-free. 3.2. EQUIPMENT DECONTAMINATION/WASTE MANAGEMENT All augers and sampling tools used for sample collection will be thoroughly rinsed with clean water after being washed with a solution of Alconox. All down-hole drilling equipment will be pressure washed prior to starting each boring. Cuttings and rinseate generated during drilling will be containerized in properly labeled,Department of Transportation(DOT)-approved 55-gallon drums and stored on-site. Disposal alternatives will be evaluated based on the results of soil and ground water analyses. 3.3. GROUND WATER EXTRACTION (AQUIFER PUMPING)TEST AGE proposes a constant-rate ground water aquifer extraction pilot(pumping)test to be performed at well MW-8 to determine the general ground water aquifer characteristics,assess aquifer response to ground water extraction, and evaluate the affects of ground water extraction at each well. A 3.5-inch diameter Grundfos submersible pump will be used to extract water from monitoring well MW-8 to induce a decline in the static water level of the well. Advanced GeoEnvironmental,Inc.