ARCHIVED REPORTS_2009_13 - Laserfiche WebLink

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1• The pH, conductivity, and turbidity meters VA be calibrated at a minimum at the be of ° gig each PSB Y 8 laky obtatncd.`standards. Calibration,wM be checked two to throe times ditring the day to evaluate the potential that the c:ali'bration is drifting throughout the day. -If k=UMOnt drift is detected in the field, the measurements taken during p and sampling will be adjusted accordfiWy, .Example calibration Iogs are included in.Appeu During purging and sampling of the wells the instruments will be used Mi the s=C Manner as&Xivg cabIntion. 2. Depth to water will be measured again, prior to sampling, in each wellas described in Section 4.4.1 and recorded on the purge 'oa and Sample Log. The volume of groundwater in the well casing will be cAcdated using the following equation(s); 4-inch well: (Total well Depth from themark an the well using (ft)'- DTW (ft)) x - 0.653 ga.Vft. Prior to purging, the-water wW bc-.cxamin -'birusing-a.Xisposable°bailcr that is clear- enough to see through. Fcaam= such as ;mmisc'ble layers will be noted and measured ^If immiscible layers-are observed the well will not be purged prior to sampling. 4. The well wdl then be purged using the e Inmip&:Dupe to the fact that the .1317,11:91M3 2= purge water from depths as great as.70 t6 80 feet blow ground surface,purge rates range from 114 to I gallon per minute.. This-purge rate docs not appear to exceed the recharge - ratcs. of the wells. -Purge water will be discharged to-the ground (see Section 4.4.,6)_ Depth to water measurements will be taken periodically duzing purging, The purlx=of these measurements is to monitor-drzwdown. If a dccrrxse in groundwater elevation is noted,the purge rate will be d=eased until equilibrium(purge rate equals recbge rate) is achieved. The fvqueacy of measurtment will be-once every five minutes initially decreasing to once every one-half hour once equilibrium has been reachecL If equilibrium cannot be reached;it will be UCCCSSW to purge the well to dryness. Prugc. - until less than iMo of the original -volume of water, in the well, Hand bailing may be requhvd to med this obj ctive. Moultor the DTW every 15 minutes to evaluate reoliatge. Start sample collection when cMer two feet of waxer has filled the well or- 1.75 - hours has elapsed since dhe end of purging. Collect volatile organics no laxer than two - hours after purging. Record all actions and mcaisurme=associated with purging a well - dry on the Purge Charraata at on and Sample Log. *23.4-US'49401123 B O1t325 A•7 July 14,2000 2M Xkw4der,be.