Laserfiche WebLink
k" KL ElNFELDER <br /> B-3.3 Equipment Decontamination <br /> To reduce the potential for cross-contamination between wells, developing equipment is washed <br /> in a trisodium phosphate or non-phosphate detergent solution and rinsed in distilled water or <br /> steam cleaned prior to use in the next monitoring well. <br /> B-3.4 Well Survey <br /> The locations of soil borings 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 <br /> depth to static groundwater is measured from a set location at the top of the PVC casing (usually <br /> the north rim). The depth of water is then subtracted from the elevation of the top of the well <br /> casing to provide a groundwater elevation for each monitoring well location. <br /> B-4 GROUNDWATER MONITORING <br /> B-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 '/z hour. <br /> 2. The water level probe 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 /> 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 /> C20-3978-03.MTG/2002P134 Page B-6 <br /> Copyright 2002,Kleinfelder,Inc. April 29,2002 <br />