ARCHIVED REPORTS XR0002680 - Laserfiche WebLink

Home Browse Search

Ir } fl Y.1• J Y.- �'-'-• l �' . 1 h- .11 , aa.f 4 1 - March 2002 I -4 la . :AGE-NC.P`roject No.-95'0114 Page 2 of-4 2.2. - COLLECTION OF GROUND WATER SAMPLES Ground wafer samples were.collected froth.each well using new disposable bailers. Following recovery of at least 80% of'the-pre-purge "casing water,volume..Immediately upon retrieval; the 'samples were transferred into 40-;ml EPA=approved'VOA vials containing 0.5 ml of hydrochloric acid.(18%) as-a sample preservative, and were labeled. The samples were transported,in a chilled container under chain-of-custody to,Cal Tech Environmental Laboratories,Inc(Cal.Tech_)of -Orange, . . a State of California Department of Health Services(DHS)-certified laboratory(#2424).The samples were analyzed for: • Volatile organic compounds(VOCs) specifically fuel additives methanol,ethanol,ethylene dibromide(EDB), I,2-dichloroethane(1,2-DCA),tertiary butanol(TBA);di-isopropyl ether ' (DIPE);ethyl-tert butyl ether(ETBE), tert amyl methyl ether(TAME), and confirmation of: ' MTBE bEPA Method 8260 Modified and • Total petroleum hydrocarbons quantified as gasoline and stoddard solvents.(TPH-g/ss) by, EPA Method 8015 Modified. " 3.0. FINDINGS Ground water flow direction and gradient were inferred from the field data. The current distribution of dissolved petroleum hydrocarbons and dissolved chlorinated hydrocarbons was assessed from laboratory analytical results of the soil and ground water samples. .3.1. . GROUND WATER GRADIENT AND.DIRECTION ' The groundwater elevations were calculated by subtracting the measured depth'to'ground water from ;the surveyed casing elevations-(Table 1). Ground water elevation s*were plotted and'contoured on scaled site map." ;During the February 2002.ground water monitoring event, the depth to ground water at the site I ,1 ganged from 22:57 to 24:19 feef below tops of the well casings.The ground water gradient and flow direction was toward the northeast with a gradient of approximately 0.002 from well-MW-1 toward well NiW-10. Ground water elevation data are summarized in Table t..The contoured ground"water elevation for the ground water monitoring`event is depictcAin Figure 3. Wells MW-3R, MW-4 and MW-5:are screened between'30-and 50 feet bsg; wells MW-6-through. MW'10 are screened between 25 and"45'6r 50 feet.bsg. Ground water is more than,6 feet above the, ` ,, ,Advanced GeoEnvironmental,Inc, i