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i <br /> Equipment Cleaning <br /> Sample bottles, caps, and septa used in sampling for volatile and sernivolatile organics <br /> were triple rinsed with high-purity deionized water After being rinsed, sample bottles <br /> were dried overnight at a temperature of 200°C Sample caps and septa were dried <br /> overnight at a temperature of 60°C Sample bottles, caps, and septa were protected from <br /> solvent contact between drying and actual use at the sampling site Sampling containers <br /> were used only once and discarded after analysis was complete <br /> Plastic bottles and caps used in sampling for metals were soaked overnight in a 1 percent <br /> nitric acid solution Next, the bottles and caps were triple rinsed with deionized water <br /> Finally, the bottles and caps were air dried before being used at the site Plastic bottles <br /> and caps were constructed of linear polyethylene or polypropylene Sampling containers <br /> were used only once and discarded after analysis was complete <br /> Before the sampling event was begun, equipment that was to be placed in the well or <br /> would come in contact with groundwater was disassembled and cleaned thoroughly with <br /> detergent water, and then steam cleaned with deaonized water Any parts that could have <br /> absorbed contaminants, such as plastic pump valves, etc , were cleaned as described <br /> above, or replaced If a positive displacement (bladder) pump is used the inside surfaces <br /> of the pump tubing were cleaned by heating the tubing overnight at 120'C with a <br /> low-flow, inert air source <br /> • Once the bladder pump was cleaned and reassembled, a pump blank was obtained by <br /> pumping organic-free water through the bladder pump assembly The pump effluent was <br /> sampled and analyzed by EPA Method 601 or EPA Method 602 The pump effluent <br /> analysis results had to have registered below the method reporting limit for each <br /> parameter before the pump was taken to the site for use <br /> During field sampling, equipment surfaces that were placed in the well or contacted <br /> groundwater were steam cleaned with deaonized water before the next well was purged <br /> or sampled <br /> Water Level, Floating Hydrocarbon, and Total Well Depth Measurements <br /> Before purging and sampling occurred, the depth to water, floating hydrocarbon thickness, <br /> and the total well depth were measured using an interface measuring system The <br /> oil/water interface measuring system consisted of a probe that emitted a continuous <br /> audible tone when immersed in a nonconductive fluid, such as oil or gasoline, and an <br /> intermittent tone when immersed in a conductive fluid, such as water The floating <br /> hydrocarbon thickness and water level were measured by lowering the probe into the well <br /> Liquid levels were recorded relative to the tone emitted at the groundwater surface The <br /> sonic probe was decontaminated by being rinsed with deionized water or steam cleaned <br /> after each use Alternatively, an electric sounder and a bottom-filling Teflon bailer may <br /> have been used to record floating hydrocarbon thickness and depth to water <br /> SAC/pj2\2520\25201000 1dl-94 He 1 A-2 Rev 0, 10/11/94 <br />