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29 September 2000 <br /> AGE-NC Protect No 97-0301 <br /> ' Page 6 of 7 <br /> will be added from the bottom of the borehole to approximately two feet above the screened interval <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 bentonite seal (bentonite pellets) will be placed above the filter pack to <br /> minimize the potential for grout penetration into the screened section of the well The bentonite seal <br /> ' will be formed by pouring bentonite pellets into the annulus and allowing them to settle on the filter <br /> pack The bentonite chips will be allowed to hydrate for a minimum of one-half hour prior to <br /> grouting <br /> ' The remaining annular space will be filled to within 1-foot of the ground surface with a cement <br /> grout The grout mixture will consist of Type DU portland neat cement and not more than 6 gallons <br /> ' of water per 94-pound sack of cement The grout will be placed by pumping through tremmie pipe <br /> A grouting inspection will be scheduled with PHS-EHD personnel A traffic rated well box will be <br /> installed over the top of the well casing <br /> 3 4 WELL DEVELOPMENT <br /> Development of the proposed wells will consist of a combination of bailing with a stainless steel <br /> p <br /> bailer to remove the major portion of fine-grained sediment from inside the well, surging to flush <br /> ' out or draw in sediment from the filter pack and additional ground water evacuation (purging)with <br /> a submersible pump to finish the removal of fine-grained sediment Developmental purging activities <br /> ' will be continued until field parameter(pH, electrical conductivity, and temperature) readings have <br /> stabilized and purged water is visually sediment-free <br /> ' 3 5 EQUIPMENT DECONTAMINATION <br /> ' All down-hole drilling and sampling equipment will be pressure washed prior to starting the boring <br /> ' 3 6 GROUND WATER MONITORING PROCEDURES <br /> Groundwater sample collection will be performed in accordance with PHS-EHD guidelines (San <br /> ' Joaquin County Public Health Services Environmental Health Division Well Standards) and <br /> CVRWQCB guidelines (Tri-Regional Water Quality Control Board Recommendations for <br /> Preliminary Investigations and Evaluation of Underground Storage Tanks) sampling protocols <br /> 1 <br /> I <br /> Advanced GeoEnwonmental,Inc <br /> 1 <br />