ARCHIVED REPORTS_2008_20 - Laserfiche WebLink

Home Browse Search

1. The pH, conductivity, and nubidlity inetess will be calibrated at aini tzm at the begin=* g of p ' day ' g ercially obta hed.scan "bration Will be checked two to three times during the day toevaluale the potential that the calibration is driffing throughout the day. ant drift is detected in the field, the measurements taken during purging and sampling will be adjusted accordhigly. Example calibration logs are included purging and sampling of the wells the i ants ` be in the a '®n- 2. Depth to water will be measured again, prior to sampiing. an each well as described in Section 4.4.1 and recorded on the Purge Cliaracttrization,and Sample Log. The velums of groundwater in the well casing will be calculated using the following equation(s): 4-inch well: (Total Well .Depth from the madc on the well casing (ft) - Ll?VI (fr)} x 0.653 gal/fL Prior to ptrrgzng, the-water -be-. Eby-using-a_disposable-bailer that is clear- enough to .sec through. Features such as immisciffile layers will be noted and-m If'hnmiscieasured- ble layers-are o ed the well " not be purged prior to sampling_ 4-. The well will then be purged using the-purge s_.:_Dere to the-fact that the pumps must { purge water from depths as great as-70 to 80 feat below ground surface-, e rates e PSS r from 114 to I gallon per minute_ This-purge rate sloes not appear to exceed the recharge rates. of the wells. Purge vrater will be discharged to-the ground (sec Section 4.4.6)_ Depth to water measurements will be taken periodically during p The purpose of these measmmments 2s to monitor-dramdown. If a in groundwatcrcdcvation is the purge rate will be decreased un (purge rate equals recharge rate) = is achieved.. The Lvquency of measurement will be-once every five minutes initia.Uy decreasing to once every onc—halfhour once equihibrium has been reached. If equilibrium cannot be reached,it will be necessmy to purge the well to ass_ c. until less than 1 Mo of the original volume of water remains in the well, Hand bailing May bo rcquired to mczt thiss objective- Monitor the DTW every 15 minutes to evaluate e. Start sample collection-vfien citlier two fed of water has filled the well or 1.75 hours has elapsed since the end of purging. Collect vv c organics no later than two hours after purging. rd all actions andan associated with purging a well dry on the Purge Charactmization and Sample 34 11231 OR323 A•7 }u}y l 4,2400 da"Ux-