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Soil and Groundwater Investigation Report
<br /> Vernalis Pump Station August 2006
<br /> collected from SB-9, SB-10, and SB-14, and the maximum concentration was 27,000 mg/kg. PAHs were
<br /> also detected in soil samples collected from SB-9, SB-10, and SB-14; however,PAH levels were all
<br /> below U.S. Environmental Protection Agency(EPA)Region 9 Preliminary Remediation Goals (PRGs).
<br /> BTEX constituents were detected in borings SB-9 through SB-14,but no concentration exceeded a PRG.
<br /> Groundwater samples were collected from monitoring wells MW-2,MW-3, and MW-4, and from boring
<br /> SB-13 and submitted to a laboratory for chemical analysis. Laboratory results for the monitoring well
<br /> groundwater samples were below laboratory detection limits for the constituents of concern. In SB-13,
<br /> the TPHd concentration detected in groundwater was 540 gg/L;however, after the silica-gel cleanup,the
<br /> TPHd concentration was reduced to 77 gg/L,which is less than the RWQCB Water Quality Objective
<br /> (WQO)of 100 gg/L TPHd. Ethylbenzene in SB-13 was reported at 0.8 gg/L,which is significantly less
<br /> than the applicable WQO of 29 gg/L(Geomatrix,2002).
<br /> 2003 Site Investigation. In August of 2003,Resonant Sonic International, Inc.,under the supervision of
<br /> Geomatrix, advanced soil borings SB-15 through SB-21, on and adjacent to the Bellini property. TPHc
<br /> were detected in all borings except SB-18. The maximum TPHc concentration detected was 39,000
<br /> mg/kg. Although benzene, ethylbenzene, and PAHs were detected in soil,no concentration exceeded a
<br /> PRG.
<br /> Geomatrix also collected grab groundwater samples from borings SB-15, SB-17, SB-18, and SB-21.
<br /> TPHg and BTEX were not detected in any of the groundwater samples. TPHd were detected in all the
<br /> groundwater samples,with the level in each sample exceeding the WQO of 100 gg/L. However,with the
<br /> silica-gel cleanup procedure,the TPHd concentrations in SB-17 and SB-18 were reduced to levels below
<br /> the WQO. The TPHd concentrations in SB-15 and SB-21 remained above the WQO (Geomatrix,2004).
<br /> Arcos Property
<br /> 2003 Site Investigations. In October of 2003, Geomatrix conducted a preliminary soil and groundwater
<br /> investigation at the Arcos property,which had not been investigated previously. The preliminary site
<br /> investigation included the review of public records,historical maps, and aerial photographs; a geophysical
<br /> survey; an evaluation of current property conditions; and a subsurface investigation. Between October 20
<br /> and 28,2003, Gregg Drilling,under the supervision of Geomatrix, advanced soil borings ASB-1 through
<br /> ASB-12 on and around the Arcos property.
<br /> TPHc were detected in borings ASB-1,ASB-2, and ASB-4, at a maximum concentration of 17,000 mg/kg
<br /> in ASB-2 at 29 feet bgs. TPHc were not detected in any other borings. Low concentrations of BTEX and
<br /> PAHs were sporadically detected in several soil samples; however,no concentration was greater than its
<br /> PRG, except benzene in ASB-2 at 29 feet bgs; and naphthalene in ASB-4 at 10.5 feet bgs.
<br /> Geomatrix collected grab groundwater samples from soil borings ASB-1,ASB-5 through ASB-8,
<br /> ASB-10,ASB-11, and ASB-12. TPHd were detected in the groundwater samples collected from borings
<br /> ASB-1,ASB-5,ASB-6,ASB-7, and ASB-11,with a maximum concentration of 2,900 gg/L in ASB-1.
<br /> However,with the silica-gel cleanup procedure,no TPHd level exceeded the WQO of 100 gg/L.
<br /> Furthermore,no BTEX constituent was detected in any sample. The only PAH detected was acenapthene
<br /> in ASB-1 at 36.5 to 45 feet bgs; however,the concentration was well below the WQO (Geomatrix,2004).
<br /> 3. SCOPE OF WORK
<br /> In order to define the extent of impacts and identify potential health risks associated with the site, SAIC
<br /> conducted the following tasks, as described in the work plan:
<br /> • Completed the requisite pre-field,project setup, and strategic planning activities, including the
<br /> site-specific Health and Safety Plan,the Journey Management Plan, and the clearance of
<br /> subsurface utilities.
<br /> 3 From Science to Solutions-
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