ARCHIVED REPORTS_2008_21 - Laserfiche WebLink

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1. The pH, conductivity, and turbidity ',et will be calibrated at a minimum at the beginning of each sampling day using Commercially obtained.standards. ibxatiou WM be checked two to three times the day to evaluate the potential that the ca ibmtlon is driffins throughout the day. If instr=Ont drift is detected in the field, the me8suremerits taken during purging and sampling wM be a4lusted accordhWjy. Example calibration logs arse included in Ap ' and sampling of the wells the instuments will be used in the a manner as during cabination. 2. Depth to water will be measured again, prior to sampling, in each wellas described in Section 4A.I and recorded on the e Ctioa and Sample Log. The volume of groundwater in the well casing will be calaflated using the following equation(s): 4-inch welt- (Total Well Depth from. the mark on the well casing (ft} - DTw (ft}} x 0.653 gal/fL Prior to purging, the-watcr,will-be•. y- a dprsposabla.baHcr that is clear- enough to see through. Features such as immisdible Jaques will be noted and measured_ ^If immiscible layers-arm observed the veli will nct be purged prior to sampling. 4. -Mc well will then be purged using the a I m mps..Dile to the fact that the Pun WS must purge water from depths as great as-70 to 80 feet below ground svrfac,,- page ram range from 1/4 to 1 gallon per minute_ This�purgc,rate docs not appear to exceed the recharge rates• of the wells- Purge vra= will be dbch=gcd to-thee ground (see Section 4.4.6)_ DtPth to water measurcWamts WM be:taken pedoc'cally dudng purzjjL& The purpo=of Ome Measurements is to madtor-drawdown. If a decrease in groundwater elevation is the purge rate will be decreased un ':um a rate equals rrcbarge rate) - is achieved. The ficque:acy of measwntnent will be-once every five minutes hfrdaIIy d to once every one4mlfhouT o=equili-briumhas been reached- If equilibrium, be readied,it will be necemary to pmgce the well to dryness. Purge Ur1til less tb= 10%of the od8ftW volume of Water.=e= in the well. Hand bailing ,ay be rcquhvd to meet this objiWv— Monitor the DTW every 15 minutes to evaluate e. Start=Wleeollection'when dtha two feet of water has filled the well or-1.75 hours has CLapsed since the end of parsing. Pollect vaWe organics no later than two hoctrs after purging, Record all actions eats associated with purging a well. dry on the purge Characterization and Sample i 84940It23IOR32S M7 Ju 2000 2040 I= IY l4 e