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I 2- Check and record the condition of the wellhead for damage or tampering. If ground conditions warrant, lay out the sheeting to encircle the wellhead to minimize the likelihood of contamination of sampling or purging equipment. Place equipment on the sheeting. Record any remarks on groundwater sample log. • 3. Unlock the wellhead. Before proceeding, record location, time, date and other information in the groundwater sampling log, 4. Remove wellhead and crack open the casing plug cap. 5. Monitor the headspace for VOCs with a Photo ionization detector(PID) or Flame ionization detector(FID) supplied with the proper lamp,and record in the sampling log. 6. Measure depth to water to nearest 0.01 feet. Measure it twice for confirmation. Measurements should be within 0.01 feet or remeasure. DO NOT MEASURE TOTAL DEPTH AT THIS TIME. 7. Check the previous sample log for well depth. Use that information to calculate the volume of the water in the monitoring well or the volume of one casing. Record this information on the groundwater-sampling log. Purging and Sampling Activities Tubing will be dedicated to each well (both silicone and poly). it will either remain in the hole at the appropriate depth (if disconnected from a peristaltic pump at the surface) or pulled out with the non-dedicated submersible pump, disconnected, reinserted and hung back in the hole at the appropriate depth, or coiled and stored in a baggie labeled with site and well I.D.for the next sampling event. If left in the hole,tubing should be marked(Sharpie indelible)to indicate proper well insertion depth. &. Non-dedicated submersible pump system — Slowly lower the pump and tubing down into the monitoring well until the location of the pump intake is set at a pre-determined location within the screen interval. Refer to the construction diagram to determine the depth and length of the screen interval. Measure the depth of the pump intake while lowering the pump into location. Record pump depth in the sampling log. 9. Dedicated submersible pump system (tubing an pump already installed) — Refer to the available monitoring well information and record on the.sampling log the depth of the dedicated submersible pump, or tubing (in the case of a peristaltic pump), hung in the well . 10.Measure the water level and record. Leaving probe in the monitoring well at depth. 11.Con nett the discharge line from the pump to a FTC. The discharge line from the cell must be directed to a container to contain the purge water. I2. Start pumping the well at a flow rate of less than 500m1/minute). Check the water level. Maintain a steady flow rate • while maintaining a drawdown of less than 0.33 feet. If drawdown is greater than 0.33 feet decrease the flow rate. 0.33 feet is a recommended goal to help guide with the flow rate adjustment, but is not mandatory. This goat may be difficult to achieve under some circumstances and may require adjustment based on site-specific conditions, and personal experience. 13. Measure the discharge rate of the pump with a graduated cylinder (1 Liter) with a watch that has a second hand. Also, measure the water level and record both flow rate and water level on the sampling log. Continue purging, monitor and record water level water-quality parameters, and pump rates every three to five minutes during purging. Pumping rates should be kept at a constant minimal flow rate to ensure minimal drawdown in the monitoring well. 14. Durin g the purging, one purging volume should be purged prior to recording the water quality parameters. Eliminate the formation of air bubbles in the tubing by rectifying leaks between spliced tubing's. Then monitor and record every three to five minutes. The stabilization criterion is based on three successive readings of the parameters;The following are the criteria which must be used: Parameter Stabilization Criteria j pH ± 0.1 pH units Specific Conductance ± 3% in S/cm Oxidation-Reduction Potential ± 10 millvolts Turbidity ± 10%NTUs(when turbidity is greater than 10 NTUs Dissolved Oxygen ± 0.3 ug/L 15. If a stabilized drawdown can't be maintained at 0.33 ft.and the water level is approaching the top of the screened interval, reduce the flow rate or turn the pump off for 15 minutes and allow recovery. Under no circumstances should the well be pumped dry or pumped below the top of the screen. After 15 minutes begin pumping at a lower flow rate, if the drawdown approaches the well screen interval again turn off the pump and allow recovery. Attempt low flow purge again. Allow recovery and proceed with sampling. This information must be noted in the groundwater-sampling log. 16. R educe the pumping rate to 100ml/minute for sampling in order to minimize disturbance of the water column. Do not go • below I00ml/minute as this may cause the pump to stall. Disconnect the tubing at the FTC. Samples should be collected directly from the discharge port of the pump tubing prior to passing through the FTC. In other words, disconnect the tubing from the FTC intake and sample at that point, not after the FTC. All VOC sample containers should be filled with minimal turbulence by allowing the groundwater to flow from the tubing gently down the inside of the container, forming 2