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k" K L E I N F E L D E R <br /> The locations of soil bo>mgs and monitoring wells, and the elevation of the top of the PVC <br /> casings are usually surveyed and tied into permanent markers, if readily available Survey <br /> accuracy is 0 1 foot for the "x" and "y" coordinates and 01 foot for the "z" coordinate The depth <br /> to static groundwater is measured from a set location at the top of the PVC casing (usually the <br /> north rim) The depth of water is then subtracted from the elevation of the top of the well casing <br /> to provide a groundwater elevation for each monitoring well location <br />' A-4 GROUNDWATER MONITORING <br /> A-4 1 Water Level Measurements <br /> Water level measurements are made in the wells prior to purging and sampling the wells <br /> Measurement protocol is as follows <br /> ' 1 Prior to obtaining water level measurements, the monitoring wells would be opened and <br /> allowed to equilibrate for a period of approximately 112, hour <br /> 2 The water levelp robe is decontaminated in a trisodium phosphate or non-phosphate <br /> detergent wash, followed by a distilled water rinse, prior to use in each well <br /> 1 <br /> 3 Water level measurements are made using a conductivity-based water-level meter <br /> Depth-to-water is generally measured from a surveyed mark on the north rim of the PVC <br /> well casing <br /> The water level measurements are converted to elevations using the surveyed casing elevations <br /> A-4 2 Groundwater Sam lin <br /> Groundwater samples are collected from the monitoring wells at the site The sampling protocol <br /> for each well is as follows <br /> 1 Down-well equipment (pumps, bailers, etc ) is decontaminated by steam cleaning, or by <br /> scrubbing in a trisodium-phosphate or non-phosphate detergent wash followed by a <br /> distilled water rinse, prior to use in each well Bailer cord is replaced prior to use in each <br /> well <br /> ' 2 The depth to groundwater is measured using a conductivity-based water-level meter <br /> 3 The volume of water in gallons standing in the well is calculated by subtracting the depth <br /> ' to groundwater measurement from the depth of the well and multiplying by the <br /> appropriate conversion factor (0 16 for 2-inch wells, and 0 65 for 4-inch wells) <br /> 4 Three to five well volumes of water are purged from each well using a submersible pump, <br /> bladder pump, or Teflon bailer <br /> 1 18748 T02 1 5T03R081 Page A-5 <br /> ©2003 Klenfelder,Inc January 23,2003 <br />