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! ti <br />' w 16 December 2005 <br /> . AGE-NC Project No 98-0465- <br /> Page <br /> 8-0465Page 2 of 6 _ <br /> , <br /> 2 1 1 Collection and Analysis of Ground Water Samples <br /> _ It <br /> Water samples were collected from each monitoring well using dedicated,disposable plastic bailers <br /> after allowing the well to achieve a minimum'80% recovery of the pre-purge water volume The" <br />' samples from each well were transferred into three 40-milliliter(ml)volatile organic analysis(VOA) <br /> vials containing 0 5 ml 18%hydrochloric acid solution as a sample preservative The samples were <br /> labeled with the monitoring well designation,date,time of sampling, and the sampler's initials, and <br /> ' transported in a chilled container under chain of custody to Cal Tech Environmental Laboratories <br /> (CTEL), a Department of Health Services-certified analytical laboratory, for analysis The samples <br />' were analyzed for <br /> ' •' Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA <br /> Method 8015-modified, <br /> • Volatile aromatic compounds benzene, toluene, ethylbenzene, and xylenes (BTEX) in <br />' <br /> accordance,with EPA Method 8260B, <br /> • Fuel oxygenates MTBE, di-isopropyl ether (DIPE), ethyl tertiary-butyl ether(ETBE), <br /> tertiary-amyl methyl ether (TAME), and tertiary butanol (TBA) in accordance with EPA <br /> t • Method 8260B, and <br /> • Fuel scavengers ethylene dibromlde(EDB)and 1,2-dichloroethane(1,2-DCA)in accordance <br />' with EPA Method 8260B <br /> 3.0. FINDINGS " <br /> Hydrocarbon Impact to groundwater were assessed by laboratory analysis Groundwater elevation , <br />' and flow direction were inferred from field data collected on 15 July 2005 <br /> 3 1 GROUND WATER GRADIENT AND FLOW DIRECTION <br /> The elevation of ground water In each of the monitoring wells was calculated by subtracting the <br />' depth to ground water from the surveyed casing elevations (Table 2) Depths to ground water <br /> averaged 11 24 feet below surface grade (bsg) Ground water elevations at the site ranged from <br />' 7 98 feet(MW-3)to 815 feet'(MW-2)below mean sea level(MSL) Ground water elevations at the <br /> adjacent site (Sanchez Property) ranged from 8 13 feet (MW-5) to 8 37 feet(MW-7B)below MSL <br /> (Table 2) During this monitoring event, the ground water elevations were within the screened <br /> intervals of the wells <br /> • T <br />' Advanced GeoEnnronmental,Inc <br /> f <br />