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s+/ \.,,f 10 June 2008 AGE-NC Project No. 97-0312 Page 4 of 11 pump islands). Procedures for well installation are presented in Section 3.2. Subsequent to installation the SVE wells,the well locations will be surveyed. 2.4. HIGH VACUUM SOIL VAPOR EXTRACTION FEASIBILITY The proposed SVE Test includes the utilization of a high vacuum [20 inches of mercury(in Hg)] SVE system intended to remove hydrocarbons from the vadose zone. Recovery of hydrocarbons from the subsurface is predicted to be difficult due to the fact that hydrocarbons are present at the site the vapor-phase and liquid-phase within fine grained material that are less permeable.Extracted vapors from the site can be treated by incineration in catalytic oxidation. AGE proposes to conduct an 8-hour SVE test to acquire information regarding the radius of influence and contaminant concentrations of soil vapor;data will be utilized to prepare for the proper design of a remediation system.The unit will be used to apply a high vacuum to proposed shallow SVE well VW-1 during the SVE test. The induced vacuum will be measured at the two proposed SVE observation wells and will be measured at several monitoring wells throughout the site to gauge any vertical response on the water table. Additionally, vapor concentrations from the active SVE well (VW-1), ground water depths and others SVE unit parameters(operation speed,air flow and vacuum)will be measured during the test. The SVE well vacuum, induced vacuum at monitoring points, extracted hydrocarbon concentrations and extraction flow rate will be measured at 120- minute intervals throughout the test. The data will aid in the estimation of the relative subsurface permeability for vapor extraction,radius of influence of the SVE well and the initial hydrocarbon recovery rate. Monitoring data from observation wells and the SVE well will be collected on field logs. Data will facilitate in the design of the SVE system and will be used to determine the number of vapor wells,spacing of the wells and selection of a vapor remediation system(e.g.catalytic thermal oxidation, carbon adsorption, etc.). The SVE pilot test specifications are presented in Section 3.4. Four vapor samples will be collected from the SVE well(VW-1)during the SVE test.Samples will be collected at approximately two-hour intervals in caracole sequestering tube and Tedlar bags and stored in a cool and dry container and transported under chain-of-custody to a California Department of Public Health(CDPH)-certified laboratory for analysis.Each vapor sample will be analyzed for: • Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA Method 8015M and Total petroleum hydrocarbons quantified as diesel (TPH-d) in accordance with TO 17; • Benzene,toluene,ethylbenzene,and total xylenes(BTEX)and fuel additives methyl tertiary- butyl ether(MTBE),tertiary-butyl alcohol(TBA),di-isopropyl ether(DIPE),ethyl tertiary- Advanced GeoEnvironmenlal,Inc.