ARCHIVED REPORTS XR0010940 - Laserfiche WebLink

Home Browse Search

--------------- 1 29 January 2003 + AGE-NC Project No. 97-0360 Page 2 of 4 the samples were properly labeled,,placed in a chilled container and transported under chain-of- custody to Cal Tech Environmental Laboratories (CTEL), a California Department of Health Services-certified laboratory. The samples were analyzed for: • Total petroleum hydrocarbons quantified as gasoline (TPH-g) and diesel (TPH-d) in accordance with EPA Method 8015 Modified; • Benzene, toluene, ethylbenzene and total xylenes (BTEX) and methyl tertiary-butyl ether (MTBE) in accordance with EPA Method 8021; and • Fuel additives including MTBE,di-isopropyl ether(RIPE),ethyl tertiary-butyl ether(ETBE), tertiary-amyl methyl ether(TAME),tertiary butanol(TBA),ethylene dibromide(EDB)and 1,2-dichloroethane (1,2-DCA) in accordance with EPA Method 826013. 3.0. FINDINGS Ground water elevation, flow direction, and gradient were determined from field data collected on - 13 August 2002;the contaminant impact to ground water was quantified by the laboratory analytical data. ;'. f3 3.1. GROUND WATER GRADIENT AND FLOW DIRECTION At the time of the August 2002 sampling event,depths to ground water in wells MW 1 through MW5 and EW1 ranged from 8.18 feet to 9.55 feet below the well heads. Ground water elevations at the site ranged from 2.78 feet above mean sea level (MSL) in well MW4 to 2.97 feet above MSL in r well MW5 (Table 1). The ground water flow direction was inferred using ground water elevation data from the monitoring wells on-site. Well MW2 was not used in ground water flow direction or gradient determination ' because it is screened at a deeper interval than the other wells. The flow direction was inferred to be toward the north at a gradient of 0.002 feet/feet. Figure 3 illustrates the contoured ground water elevations as measured on 13 August 2002. 3.2. ANALYTICAL RESULTS OF GROUND WATER SAMPLES TPH-g was detected in the ground water samples collected from wells MW 1 and EW 1 at concentrations of 170 micrograms per liter (ugll) and 290 gg/l, respectively. TPH-d was detected Advanced GeoEnvironmental,Inc.