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08 July 1999 <br /> AGE-NC Project No. 95-0130 <br /> Page 9 of 10 <br /> the potential for grout penetration into the screened section of the well. The bentonite seal will be <br /> formed by pouring bentonite chips into the annulus and allowing them to settle on the filter pack. <br /> The bentonite chips will be hydrated using approximately five gallons of tap water and will be <br /> allowed to hydrate for a minimum of one-half hour prior to grouting. <br /> The remaining annular space will be filled to the ground surface with a cement grout. The grout <br /> mixture will consist of Type MI portland neat cement and not more than 6 gallons of water per 94- <br /> pound sack of cement. The grout will be placed by pumping through tremmie pipe. A grouting <br /> inspection will be scheduled with PHS-EHD personnel. A proposed ground water monitoring well <br /> construction diagram is depicted in Figure 3. <br /> 4.4. WELL DEVELOPMENT <br /> Well development will consist of a combination of bailing to remove the major portion of fine- <br /> grained sediment from inside the well, surging to flush out or draw in sediment from the filter pack <br /> and additional bailing to finish the removal of sediment. Development activities will be continued <br /> until field parameter (pH, electrical conductivity, and temperature) readings have stabilized and <br /> purged water is visually sediment-free. <br /> 4.5. GROUNDWATER SAMPLING 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 /> 4.5.1. Static Water Level Measurements <br /> Prior to purging and sampling during quarterly groundwater monitoring events and initial sampling <br /> event, static water level in each well will be measured using an electric water level indicator. Water <br /> level data will be recorded to the nearest 0.01 foot from a reference point marked on the top of the <br /> PVC well casing. Before and after each use,the measurement device will be rinsed with water. <br /> 4.5.2. Well Evacuation <br /> Subsequent to measurement of depth to water and prior to sampling, each well will be purged using <br /> Advanced GeoEnvironmental,Inc. <br />