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ALTON GEOSCIENCE <br /> . GENERAL FIELD PROCEDURES FOR <br /> GROUND WATER MONITORING WELL DEVELOPMENT AND SAMPLING, <br /> AND WATER SAMPLING FIELD SURVEY FORMS <br /> Ground Water Monitoring Well Development <br /> Ground water monitoring wells were initially developed to clean <br /> the well and stabilize sand, gravel, and aquifer materials around <br /> the perforated section. Well development was conducted using one <br /> of several acceptable methods, such as bailing, mechanical or air <br /> lift pumping, surging, or swabbing. Purging and ground water <br /> sampling equipment was cleaned prior to use and between wells to <br /> minimize cross-contamination. All equipment in contact with <br /> ground water was triple-rinsed prior to each sampling event in <br /> successive baths consisting of phosphate-free Liquinox solution, <br /> water, and deionized water. The wells were developed in <br /> accordance with the Regional Water Quality Control Board, Central <br /> Valley Region (RWQCB) , requirements. Each well was developed by _ <br /> removing at least 10 casing volumes of water. <br /> Well development continued until the well was thoroughly <br /> developed and free of sand, silt, and turbidity and until pH, <br /> temperature, and electroconductivi.ty parameters stabilized, <br /> indicating formation water had entered the well casing. <br /> Water generated from the development process was placed into <br /> labeled 55-gallon drums pending laboratory results of the ground <br /> water samples, to determine the appropriate disposal method. <br /> Disposal of the water conformed to applicable requirements. <br /> Ground Water Monitoring Well Sam lin <br /> Prior to well sampling, ground water in each well was monitored <br /> for the presence/absence of free-floating product or sheen. The <br /> depth 4 -D ground water was measured with an accuracy of 0. 01 foot <br /> from the top of the polyvinyl chloride (PVC) casing using an <br /> electronic sounder. <br /> To ensure the ground water sample was representative of the <br /> aquifer, the well was purged of 3 to 10 well casing volumes <br /> before sample collection. This purging was accomplished using a <br /> clean bailer or pump. <br /> The samples were collected using a clean bailer, then carefully <br /> transferred into the appropriate clean glass laboratory-supplied <br /> containers. Samples were inverted to ensure entrapped air was <br /> not present. The samples were handled and preserved in <br /> accordance with RWQCB guidelines. The samples were clearly <br /> labeled with well number, <br />