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Christy Woodward <br />September 17, 2008 <br />Page 11 <br />Groundwater Monitoring Well Development <br />Once installed, the monitoring wells will be developed prior to sampling. Monitoring well <br />development will be achieved using the same equipment that will be used for groundwater <br />sampling. The intent of well development is to remove fines within the well boring produced <br />by drilling and to stabilize groundwater quality. A well is designated as developed when the <br />field parameters of the water produced from it varies less than 10 percent over three <br />consecutive measurements for each casing volume purged. The casing volume will consist of <br />the open interval plus the entire volume of the PVC above the packer. The field parameters to <br />be tested for variability include pH, conductivity, and temperature. If a well is pumped to <br />dryness before the field parameters stabilize, the development process is considered <br />complete. <br />If necessary, water will be pumped from the wells using a peristaltic pump In this process, <br />1/4 inch poly tubing will be connected to the outlet port on the well cap. An approximately 8- <br />inch piece of 3/8 inch silicon tubing will be attached to the 1/4 inch poly tubing to feed <br />through the peristaltic pump. Additional 1/4 inch poly tubing will be attached„to the outlet <br />side of the silicon tubing and then to a flow through cell with YSI multi-meter attached. <br />Additional 1/2 inch poly tubing will be attached to the outlet side of the flow through cell. <br />Purged water from well development will be drained into the underground working sump. <br />Groundwater Sample Collection <br />Once groundwater monitoring wells are completed and developed, groundwater samples <br />will be collected, provided there is adequate time for well recharge. Groundwater samples <br />will be collected using the same apparatus as described for well development. <br />Prior to collecting groundwater samples, the monitoring well must be adequately purged. If <br />sampling is conducted immediately following completion and development of the well (i.e. <br />within 1 to 2 days), purging of the well is not required. The general method of well purging is <br />defined as follows: <br />1. Make all peristaltic pump and flow through cell tubing connections as described <br />above under groundwater monitoring well development. <br />2. Turn on peristaltic pump. After 5 minutes of pump operation, take the initial <br />recording of YSI measurements. <br />3. After 5 and 10 minutes take the second and third readings of the YSI, respectively. <br />Parameter measurements will be considered stable when pH, conductivity, and <br />temperature readings have stabilized to within +/- 0.2 standard units, 10 percent, and <br />2.0 degrees Fahrenheit, respectively. If each parameter has not yet met the stabilization <br />criteria after the 3rd five-minute pumping period, a 4th pumping period will be <br />completed. A maximum of 5 five-minute pumping intervals will be removed from the