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METHODS AND PROCEDURES, QA/QC <br /> This Appendix documents the specific methods, procedures, and materials used to collect <br /> and analyze groundwater samples and monitoring the vapor recovery system <br /> Gauging and Measuring Monitor Wells <br /> Prior to sampling a well, a WEGE personnel obtains two measurements the depth to <br /> groundwater and the product thickness using a battery powered depth to water-product <br /> interface probe and or by using a specially designed bailer The probe is lowered into the <br /> well casing until the instrument signals that the top of water has been reached The <br /> distance from the top of water to the top of casing is read from the tape calibrated in 0 01 <br /> foot intervals for accuracy to 0 01 foot, that is attached to the probe The measured <br /> distance is subtracted from the established elevation at the top of casing to determine the <br /> elevation of groundwater with respect to mean sea level The probe is washed with TSP <br /> and rinsed to distilled water before each measurement WEGE has designed and built <br /> bailers that will collect a sample of the contents of a well to show the exact thickness of <br /> any floating product <br /> Purging Standing Water from Monitor Wells <br /> If no product is present, WEGE personnel purge the well This is accomplished by <br /> removing groundwater from the well until the water quality parameters (temperature, pH, <br /> and conductivity) stabilize, or until the well is emptied of water Periodic measurements <br /> of groundwater temperature, pH, and conductivity were taken with a Hydac Monitor or <br /> other meter and recorded along with the volume of groundwater removed from the well <br /> Purging is done by one or more methods singularly or in combination Bailers, <br /> pneumatic or electric sample pumps, or vacuum pump tanks or trucks may be used The <br /> usual amount of water removed is three well volumes The water collected during <br /> purging :s either safely stored onsite for later disposition, transported to an approved <br /> onsite or offsite sewer dsscharge system, or an approved onsite or offsite treatment <br /> system <br /> Collection of Water Sample for Analysis <br /> The well is allowed to recover after purging and a groundwater sample is collected A <br /> fresh bailer is used to collect enough water for the requirements of the laboratory for the <br /> analyses needed or required The water samples are decanted from the bailer into the <br /> appropriate number and size containers These containers are furnished pre-cleaned to <br /> exact EPA protocols, with and without preservatives added, by the analytical laboratory <br /> or a chemical supply company The bottles are filled, with no headspace, and then <br /> capped with plastic caps with teflon liners <br /> QM 4th 2002 <br />