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CAMBRIA <br /> Well Development <br /> Wells are generally developed using a combination of ground water surging and extraction Surging <br /> agitates the ground water and dislodges fine sediments from the sand pack After about ten minutes <br /> of surging, ground water is extracted from the well using bailing, pumping and/or reverse air-lifting <br /> through an eductor pipe to remove the sediments from the well Surging and extraction continue <br /> until at least ten well-casing volumes of ground water are extracted and the sediment volume in the <br /> ground water is negligible This process usually occurs prior to installing the sanitary surface seal <br /> to ensure sand pack stabilization It development occurs after surface seal installation, then <br /> development occurs 24 to 72 hours atter seal installation to ensure that the Portland cement has set <br /> up correctly <br /> All equipment is steam-cleaned prior to use and air used for air-lifting is filtered to prevent oil <br /> entrained in the compressed air from entering the well Wells that are developed using air-lift <br /> evacuation are not sampled until at least 24 hours after they are developed <br /> Ground Water Sampling <br /> Depending on local regulatory guidelines, three to four well-casing volumes of ground water are <br /> put ged prior to sampling Purging continues until groundwater pH, conductivity, and temperature <br /> have stabilized Groundwater samples are collected using bailers or pumps and are decanted into <br /> the appropriate containers supplied by the analytic laboratory Samples are labeled, placed in <br /> protective foam sleeves, stored on crushed ice at or below 4°C, and transported under chain-ot- <br /> c.u,,tody to the laboratory Laboratory-supplied trip blanks accompany the samples and are analyzed <br /> to check for cross-contamination An equipment blank may be analyzed if non-dedicated sampling <br /> equipment is used <br /> F 1TEMPLATEWPs1WELLS GW WPD <br /> Page I of 3 <br />