ARCHIVED REPORTS XR0009124 - Laserfiche WebLink

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' 24 March 2004 AGE-NC Project No 97-0301 ' Page 2 of 5 MW-7, and approximately 0 4 to 5 gallons were purged from multi-level wells MW-8 through MW-12 Each well was purged by lowering and raising a 3/8-inch outer diameter, length-discrete polyethylene hose equipped with a ball-valve water tip through the top chambers Into the specific ' water-charged screened section A Watera-Hydro-Lift 11 pump equipped with a mechanical arm was utilized to surge each well with a polyethylene hose Temperature, pH and conductivity were measured for stabilization at regular purge-volume Intervals from each well using an Oakton water analyzer Field data and logs are Included with Appendix A Purged ground water was containerized in 55-gallon drums and was stored on-site in an area lacking general public access ' 2 2 GROUND WATER SAMPLING ' After each well was purged,ground water levels were measured to verify the amount of ground water recharge Upon achieving at least 80% ground water recharge, samples were collected from wells MW-1 through MW-12 utilizing the techniques described above in purging each well,however,80% recharge was not achieved from wells MW-12A and MW-12D due to a combination of water drawn- down nearly to the bottom of the screen section and slow recharge Ground water samples were transferred into 40-m1 EPA-approved volatile organic analysis(VOA)vials containing 0 5 ml 18% ' hydrochloric acid as a sample preservative and 1-liter amber bottles without sample preservative Care was taken to ensure that visible air bubbles were not present in the vials after filling and ' capping Ground water sample containers were labeled with the well designation, date, time, and sampler's initials ' 23 LABORATORY ANALYSIS OF GROUND WATER SAMPLES ' Following collection and labeling,each ground water sample was logged on a cham-of-custody form, placed in a chilled container and transported to a Cal Tech Environmental Laboratories,a California Department of Health Services (DHS)-certified laboratory, for analysis for • Total petroleum hydrocarbons quantified as gasoline,diesel,kerosene and motor oil(TPH-g, TPH-d, TPH-k and TPH-mo respectively)by EPA Methods 8015C/5030B/3510C, ' • Benzene, toluene, ethyl benzene and xylene (BTEX), methyl tertiary-butyl ether (MTBE) 1,2-Dichloroethane(1,2-DCA),ethylene dibromide(EBD),di-isopropyl ether(DIPE),ethyl ' tert butyl ether(ETBE),tert amyl methyl ether(TAME) and tertiary butanol(TBA)by EPA Method 8260B Advanced GeoEnvironmental,Inc 1