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kn K L E I N F E L D E R <br /> Monitoring wells are generally developed 24 to 48 hours after installation to allow the grout to <br /> is set Each well is first sampled with a clear disposable bailer to visually Inspect for a hydrocarbon <br /> layer or sheen If no product layer or sheen is observed on the water, the well is developed by <br /> surging, pumping or balling Surging along the screened Interval of the well Is performed to <br /> draw the sediment from the formation into the filter pack and the well, and to set the sand pack <br /> Development continues until the discharge runs relatively clear of fines Approximately 5 to 10 <br /> well volumes are generally removed from each monitoring well Discharge water is stored in 55- <br /> gallon drums and left on site for later discharge or disposal by the client, depending on laboratory <br /> results The drums are labeled with the date, well number, and a contact person and phone <br /> number <br /> A-3.3 Eq <br /> mmment 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 /> A-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 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 I 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 % 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 /> 20-4439-0I E04/ST02R397 Page A-5 <br /> CoPyright 2002, Kleinfelder,Inc August 22,2002 <br />