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SOP No. 22.0 Purging and Sampling Monitoring Well <br />d. Re-measure the field parameters each time another full casing volume has been <br />removed, and just before sampling. <br />e. Bail a maximum of three full casing volumes in 4 hours. Do not bail more than three <br />casing volumes from a low or moderate yield well, as the time required would be <br />excessive. <br />f. If the well has produced only two full casing volumes at the end of 4 hours, proceed <br />to sample. <br />g. If the well has not produced two full casing volumes after 4 hours, bail the well dry <br />one more time. Return to sample in 4 more hours (total time from first bailing until <br />sampling equals 8 hours). <br />h. If the well has not recovered at all within 4 hours, do not sample. <br />10. After the minimum purge volume has been removed, review the geochemical <br />measurements to ensure the readings have stabilized. Readings should be within 10% of <br />the previous reading. If the geochemical parameters have not stabilized, continue to <br />purge the well until the monitoring parameters do not vary more than 10 percent between <br />two successive well volumes removed. <br />11. Collect the groundwater samples after purging is complete (see above). When collecting <br />samples, lower the bailer slowly to avoid agitating the water. <br />12. Once the sample has been taken, properly dispose the used string, gloves, and paper <br />towels. <br />Purging with a Pump <br />1. Ensure that fine sediment has been removed by well development. <br />2. Determine the volume of water per well casing. <br />3. Refer to the user's manual for pump operating instructions. Users manuals for the <br />Grundfos Redi-flo 3 and the ProActive Hurricane are included in Attachment 1. <br />4. Assemble pump, tubing or hoses and safety cable. <br />5. Do not allow pump, pump lead, tubing, or hoses to come into contact with the ground <br />surface. Place plastic sheeting around the well if necessary. <br />6. Slowly lower the pump and tubing to a depth approximately 10 ft below the water level. <br />Make sure the pump is deep enough so that purging does not evacuate all the water. <br />(Running the pump without water may cause damage.) <br />a. Attach pump power supply. <br />b. Begin pumping. <br />c. Collect water quality parameters. <br />d. As pumping continues, take water level readings periodically and lower pump as <br />necessary to ensure the pump does not run dry. <br />7. Dispose of the pumped water in an appropriate container for later disposal in compliance <br />with federal and state laws. <br />4/23/07 Page 4 of 7 R Squared Inc. <br />Attachment A