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APPENDIX F ALTON GEOSCIENCE WELL DEVELOPMENT, WATER SAMPLING PROCEDURES, AND FIELD SURVEY FORMS Ground Water Monitoring well Development Ground water monitoring wells were initially developed to clean the well and stabilize sand, gravel, and aquifer materials around the perforated section of the well. Well development was conducted using one of several acceptable methods, such as bailing, mechanical or air lift pumping, surging, or swabbing. All purging and ground water sampling equipment was cleaned prior to use and between wells to minimize cross-contamination. All equipment in contact with ground water was triple-rinsed prior to each sampling event in successive baths consisting of phosphate- free Li.quinox solution, water, and deionized water. The wells were developed in accordance with the Regional Water Quality Control Board, Central Valley Region (RWQCB) requirements. Each well was developed by removing at least 10 casing volumes of water. Ground Water Monitoring Well Sampling Prior to well sampling, ground water in each well was monitored for the presence/absence of free-floating product or sheen. The depth to ground water was measured with an accuracy of 0. 01 foot from the top of the polyvinyl chloride (PVC) well casing using an electronic sounder. To ensure the ground water sample was representative of the aquifer, the well was then purged of 3 to 10 well casing volumes before sample collection. This purging was accomplished using a clean bailer or pump. The ground water samples were collected using a clean bailer, then carefully transferred into the appropriate clean glass laboratory-supplied containers. All samples were inverted to ensure that entrapped air was not present. The water samples were handled and preserved in accordance with RWQCB guidelines. The sa-nples were clearly labeled with well number, site identification, date and time of sample collection, and sampler's initials, and transported to a California-certified laboratory. Samples were kept on cubed, crushed, dry, or blue ice prior to and during transport to a California-certified laboratory following EPA protocol and proper chain of custody procedures. Water samples were collected from Monitoring Wells MW-7 , MW-8 , MW-10 , MW-11, and MW-12 to confirm the presence or absence of denser than water, non-aqueous phase liquid (DNAPL) . Water samples were collected from the bottom of these wells using a bottom check-valve bailer after following the above procedures.