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should force water in and out of the screened interval. Repeat the surge/swab at least 10 <br /> times at each 2-foot interval. Then swab the next two-foot screened interval. Follow each <br /> round of surging by purging. <br /> Purging: Following each round of surging of the screened interval, the well shall be purged <br /> of water. Be sure to lower the bailer to the bottom of the well in order to"grab" the silts and <br /> clays that have settled to the bottom of the well. If a well has a large portion of fines, then <br /> the purging may be performed only using a bailer, since silts and clays can cause <br /> malfunction in the pumps. <br /> • Please note, to develop the entire screened interval, water must be present over the entire <br /> length of screen. In wells with little water or with very poor recharge, distilled water may be <br /> added to the well to ensure adequate development of the well. If water is added, the volume of <br /> water added must be documented, and the water being used should be sampled for the <br /> presence of contaminants. <br /> • Continue the process until the entire screened interval has been adequately swabbed and <br /> purge water is relatively clear of fine material. <br /> • Contain all purge water in the drums or other containers provided. Denote the date, time and <br /> origin of the water on the containers. Include calculation of the volume of water removed from <br /> each well and observations of the presence of sediments and color/odor of water, etc., in the <br /> logbook and on the forms provided. <br /> • Obtain final depth to groundwater level readings from the point of survey mark, or from the <br /> North side of the top of the PVC casing, if not point of survey mark is present. Readings will be <br /> measured to the nearest 0.01 foot. Denote time and readings in logbook and on forms provided. <br /> • Conduct final decontamination procedures of any field equipment that is not disposable. <br /> • Close and secure each well upon completion of field activities. Ensure that all water storage <br /> containers are closed and secured and that the site is clean. <br /> GHD SOP MVV Install&Dev 6 of 6 Rev 2/14 <br />