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Water levels will be measured with an eiecrric Sounder. The electric sounder is a <br /> transistorized instrument that uses a reel-mounted, two conductor, coaxial cable that <br /> connects the control panel to the Sensor. Cable markings are stamped at 1-foot <br /> increments. The water level will be measured by lowerm�� the sensor into the monitoring <br /> well. A low current circuit iS completed when the sensor contacts the water, which serves <br /> as an electrolyte. The current is amplified cInd fed Hiro an indicator light and audible <br /> buzzer, signaling when water has been contacted. A sensitivity control compensates for <br /> very saline or conductive water. Tile electric sounder will be decontaminated by rinsing <br /> with deionized water after each use. r <br /> Depth to water will be recorded to the nearest 0.01 foot in the field logbook. The <br /> groundwater elevation at each monitoring well will be calculated by subtracting the <br /> measured depth to water from the Surveyed elevation of the top of the well casing. Well <br /> total depth is then measured in the monitoring_ wells scheduled for sampling by lowering <br /> the sensor to the bottom of the well. Well total depth, used to calculate purge volumes <br /> and to determine whether the well screen is partially obstructed by slit, will be recorded <br /> to the nearest 0.5-foot in the field logbook. <br /> Sample Collection <br /> Sample collection procedures include equipment cleaning, well purging, and sampling. <br /> Equipment Cleaning <br /> Sample bottles, caps, and septa used in sampling for volatile and semivolatile organics <br /> will be triple rinsed with high-purity deionized water. .after rinsing, sample bottles will <br /> be dried overnight at 200 deg-rees Celsius. Sample caps and septa will be dried overnight <br /> at 60 degrees Celsius. Sample bottles, caps, and septa will be protected from all forms <br /> of solvent contact between drying and actual use at the sampling site. Sample bottles, <br /> caps, and septa will be used only once and discarded after analysis is complete. <br /> Sample bottles and caps used in sampling for chlorinated pesticides and polychlorinated <br /> biphenvls (PCBs) will be triple rinsed with high purity deionized wetter. The sample <br /> bottles will be rinsed with pesticide grade hexane and dried overnight at 200 degrees <br /> Celsius. Sample caps will be dried overnight at 60 degrees Celsius. Sample bottles and <br /> caps will be used only once and discarded after analysis is complete. <br /> Plastic bottles and caps used in sampling for metals will be soaked overnight in a one <br /> percent nitric acid solution. The bottles and caps will then be triple rinsed with deionized <br /> water, and air dried before bein�� used at the site. All plastic bottles and caps will be <br /> constructed of linear polyethylene or polypropylene. Plastic bottles and caps will be used <br /> only once and discarded after analysis is complete. <br /> 'RL-/Sample.arc-93/jes:0 A-2 Rev.U.06/21/95 <br />