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analyzed by USEPA Method 601. The pump effluent analysis results must be below the method <br /> reporting limit for each parameter before the pump is taken to the site for use. <br /> During field sampling, equipment surfaces that are placed in the well or contact groundwater are <br /> steam cleaned with deionized water before the next well is purged or sampled. <br /> Water-level and Total Well-depth Measurements <br /> Immediately before a monitoring well is purged, the water level and total well depth are measured <br /> using an electric sounder as described above. The electric sounder is decontaminated by rinsing <br /> with deionized water after each use. <br /> Well Purging <br /> Standing water in the casing and gravel pack is purged from the monitoring well using a dedicated <br /> Well Wizard® bladder pump, pneumatic displacement pump, or Teflon bailer, prior to collecting <br /> samples. Monitoring wells are purged according to the protocol presented in Figure A-1. In most <br /> cases, the amount of water purged before sampling is equal to or greater than three casing volumes. <br /> In cases where the monitoring well is evacuated to dryness prior to the removal of three casing <br /> volumes, due to the low yield of the well, the well is allowed to recharge for up to 24 hours. <br /> Samples are taken as soon as the monitoring well has recharged to a level sufficient for sample <br /> collection. If insufficient water has recharged after 24 hours,the monitoring well is recorded as dry <br /> for the sampling event. <br /> Well Sampling <br /> A Teflon bailer or bladder pump is the only equipment acceptable for well sampling. Unless <br /> otherwise described, the sample containers for all parameters are filled, filtered as required, and <br /> capped. <br /> Volatile Organic Compounds (VOCs) <br /> When samples for volatile organic analysis are collected with a bladder pump, the pump flow is <br /> regulated to approximately 100 milliliters per minute to minimize pump effluent turbulence and <br /> aeration. Glass bottles of at least 40 milliliters volume and fitted with Teflon-lined septa are used <br /> in sampling for volatile organics. These bottles are filled completely to prevent air from remaining <br /> in the bottle. A positive meniscus forms when the bottle is completely full. A convex Teflon <br /> septum is placed over the positive meniscus to eliminate air. After the bottle is capped, it is <br /> inverted and tapped to verify that it contains no air bubbles. <br /> Dissolved Metals <br /> To determine dissolved concentrations of metals, appropriate field filtration techniques are used. <br /> When using a Teflon bailer, the sample is filtered by emptying the contents of the bailer into a <br /> a NAMiscellaneous\Groundwater Info-All Sites\SAP_AppendixA.doc <br /> A-3 <br />