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ang= �a - - KI WIN 00 r� Ms. Diane Lundquist October S. 1990 Page 8 j Aber the initial pump test, a soil venting vacuum blower was connected to the manifold system that connects MW-1 through MW-9, initially,MW-7 was opened to the blower for 4 hours, During the 4- hour venting period,ground water wasum soil venting 'Rte airflow from MW-7 was measured o be apprc4dmately 20 cubic feet sminute3cfm) G! n for at a vacuum of 75 inches of water, Additionai wells were added to the test until a total of five wells (MW-Z MW-3,MW-4,MW-5,and MW-7)were fully opened to the soil venting blower. The flow from the system with five wells opened was 44 cfrn at a vacuum of 61 inches of water. The soil vapor exhaust was measured using a TLV sniffer and an axplosimeter,both calibrated to hexane, The sniffer showed that the hydrocarbon concentration in the soil vapor exhaust exceeded the meter's measuring limit of 10,000 ppm. The explosimeter at times showed b explosive limit of hexane 11800 ydtocarbon concentration of lo0-r percent of the MW-2 and MW-7 were the Only wells opened to the�vacutusource.t hydrocarbon �1� .2 d MW-7 are Incentrations were � when the free-phase petroleum product zone orated in In order to maintain enough well screen exposure for proper soil ventin from.MW-7. Under a vacuum of approximately 5 feet of water and a pumping rate of b ter waspumped the drawdown stabilized at anFroximately 8.6 feet below static water level in MW-7. ' During the ground water pumping operation,ground water samples were collected at threee rentl intervals from MW-Ts discharge water. Discharge samples were collected during the 9th,23rd,and 34th hours of the pump test. The samples were analysed for BTEX and TPH concentrations WA Methods 5030/8015/8020). To meet sewer discharge requirements,the discharge samples collected during the 23rd hour were also analyzed for the following concentrations-- • oncentrations• Purgeable aromatics( EPA Method 602). • Purgeable halocarbons (EPA Method 601), • Halogenated volatile organics(EPA Method 8010), • Total organic carbon. " • General minerals, i.. • Chemical oxygen demand, e • Nitrogen-ammonia. • Nitrate. � • Nitrite. • Orthophosphate. 1 • Semiquantitative ICP metals scan. The results of these analyses can be found in the state-certified laboratory reports located in , Enclosure F. The source test data and results will be included and discussed further in the final remedial action plan i prepared for the subject site, The source test data and results will be used to design the soil venting r system,air emission controls,to predict the ground water pumping rate,and to design the ground water treatment system. 'i Additional htonitorin Wel! Installation To further define the extent of petroleum constituents is ground water downg adient from the site, [ ' I mlonitoring wells MW-10 and MW-11 are proposed at locations illustrated in figure 2 } `I 1 � F ',s