Laserfiche WebLink
I <br /> I09 April 1999 <br /> AGE-NC Protect No 96-0229 <br /> Page 2 of 5 <br /> I2 2 GROUND WATER SAMPLING <br /> Following purging, ground water levels in monitoring wells MW-1 through MW-10 were allowed <br /> to achieve a minimum of 80 percent recharge prior to sample collection Ground water samples were <br /> collected from the purged wells utilizing new,disposable polyethylene bailers and four 40-m1 EPA- <br /> approved VOA vials containing 0 5 ml 18% hydrochlonc acid as a preservative Care was taken to <br />' ensure that visible air bubbles were not present in the vials after filling and capping Ground water <br /> sample containers were labeled with the well designation, date, time, and sampler's initials <br />' <br /> 23 LABORATORY ANALYSIS OF GROUND WATER SAMPLES <br />' Each ground water sample was logged on a chain-of-custody form,placed in a chilled container and <br /> transported to a California Department of Health Services (DHS)-certified laboratory for analysis <br /> in accordance with <br /> • EPA Method 8015M for total petroleum hydrocarbons quantified as gasoline (TPH-g), <br /> • EPA Method 8020 for volatile aromatics (benzene, toluene, ethyl benzene and xylene <br /> BTEX) with methyl-tertiary butyl ether (MTBE), and <br /> • EPA Method 8250 for tertiary butanol (TBA), di-isopropyl ether (DIPS), ethyl tert butyl <br /> ether (ETBE), tert amyl methyl ether (TAME) and MTBE <br /> 30. FINDINGS <br /> From the field data, AGE was able to determine the ground water flow direction and gradient <br /> Laboratory analysis of eleven ground water samples detected petroleum hydrocarbons, volatile <br /> aromatics and oxygenated fuel additives in six of the eleven ground water samples <br /> 3 1 RELATIVE GROUND WATER ELEVATION AND GRADIENT <br /> During the January 1999 monitoring event, depths to ground water from wells MW-1 through MW- <br /> 10 were measured between 25 39 and 28 16 feet below the tops of well casings, ground water <br /> elevations were calculated to be between 15 82 feet and 17 05 feet below mean sea level Ground <br /> water elevation at the site decreased an average 0 18 feet between the October 1998 and the January <br /> 1999 ground water monitoring events The ground water elevation data for MW-1 through MW-10 <br /> during the January 1999 ground water monitoring event is depicted in Figure 3 <br /> Advanced GcoEniiron mental,Inc <br />