Laserfiche WebLink
' k" K L F I N F E L D F R <br /> A-3 2 Monitoring Well Development <br />' The wells are developed to reduce the effects of drilling on the formation and to increase the <br /> P g <br /> effective hydraulic radius of the wells <br /> Monitoring wells are generally developed 24 to 48 hours after installation to allow the grout to <br />' set Each well is first sampled with a clear disposable bailer to visually inspect for a hydrocarbon <br /> layer or sheen 1f no product layer or sheen is observed on the water, the well is developed by <br /> surging, pumping or bailing Surging along the screened interval of the well is perfonned 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 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 /> 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 easing <br /> 1 to provide a groundwater elevation for each monitoring well location <br /> i <br /> 1 <br /> 20-4439-01 F-02/2011 R355 Page 5 of 9 <br /> Copynght 2001, Kleinfelder, Inc April 2,2001 <br />