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<br /> i
<br /> . . I'FMLLM A55ESSMENr FCPMT
<br /> IrC'uoiNn omm'EALY w0m1o1CNQ FlEF0w
<br /> p9 1791 EaM Yosemile Avenue,7denlote,Calllorn+e
<br /> for
<br /> S,and
<br /> H, as gasoline.
<br /> Groundwater samples from Ma line,Were detected in concentrations ons of 3 0,, 1.2, and 80 ppb,
<br /> Xyl3nes, EDC, and TPM, as g
<br /> investigation were reported in the Preliminary
<br /> respectively (Table 3). Results from the E S
<br /> R� Hydrologic Assessment Workplan (Delta, 1988).
<br /> 2 4 2 Delta Environmental Consultants, Inc.
<br /> Two soil borings were drilled and converted into groundwater monitoring wells by Delta in
<br /> April 1989. The borings were completed as 2-inch-diameter wells (MW-2 and MW-3) to an
<br /> approximate depth of 361h feet (Figure 2).
<br /> F A soli sample from 20 feet below ground surface was obtained from MW-2. Soil samples
<br /> were obtained from 15- and 20-foot depths in MW-3. Soil samples were analyzed for BTEX,
<br /> -a
<br /> EDC, EDB, and TPH, as gasoline. The sample from MW-2 showed no concentrations of
<br /> i ction limits. The 15-foot sample from ab 2showed 0.1, 0.2,
<br /> analytes greater than the dete
<br /> 0.1, 1.0, and 60 ppm of BTEX and TPN, as gasoline, respectively (T )•
<br /> -+ MW-1 through MW-3, were
<br /> Groundwater samples from the three on site monitoring wells,
<br /> analyzed for BTEX, EDC,EDB, t fiTian the detection limPH, as.gasoline. its. Benzeample fne etrom hY enz�ene, xylenes,
<br /> concentrations of analytes greater
<br /> EDC, and TPH, as gasoline,were found in MW-2 at levels of 8.�+, 4.0, 4.0, 0,3, and 200 RR
<br /> respectively. The groundwater sample from mW
<br /> xylenes,and EDC
<br /> oltainanlet3)I Results of the investigation
<br /> at concentrations of 2.0, 10.0,and 10 ppb, respectively (T
<br /> were reported in Preliminary Hydrologic Assessment Report (Delta, 1989).
<br /> On September 26, 1989,the 6,000-,8,000-,and 10,000-gallon USTs usoXd�artely gasoline earsro dr
<br /> were removed. At the time °sail�samclestwere tobt he tined beneathSTs were theend of the USTs and
<br /> During removal of the tanks, R
<br /> at intervals of 20 feet beneath the product pipelines. Three sc,i� borings were drilled in the
<br /> Concentrations of TPH in the samples collected from the soli
<br /> sin. Co Its of
<br /> former tank ba 4 . Results area of the#o
<br /> rm le
<br /> samples and o borings
<br /> i thorted in Problem Assessmenttank basin ranged from 0.7 Report (NGA, 990)•
<br /> the tank rem R
<br /> On October 20, 1989, subsurface components of a soil venting system were installed in the
<br /> former tank basin cn the site. After the system installation paved
<br /> asphalt. The instal installation tank
<br /> f the soil
<br /> backfilled with soil,compacted, and the surfpit was
<br /> ace pave R
<br /> venting system was reported in Problem Assessment Report (NGA, 1990)•
<br /> i
<br /> I�Esllllx NMI
<br /> •T
<br /> 50-09BC.FaPT
<br />
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