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' Soil and Groundwater Investigation Report <br /> Tracy Byron Road Project May 2008 <br /> • Conducted a site visit to mark boring locations for Underground Service Alert (USA),notified <br /> ' USA at least 48 hours in advance of field activities, and requested USA to mark underground <br /> facilities in adjacent public ROWS. <br /> ' • Subcontracted Cruz Brothers Locators, a private utility locator, to survey the site and proposed <br /> boring locations for any potential overhead and underground hazards and/or other potential <br /> obstacles. <br /> ' • Obtained soil boring permits from the SJCEHD. <br /> 3.2 FIELD INVESTIGATION ACTIVITIES <br /> ' To define the extent of affected soil and groundwater at the site, borings SB-37 through SB-41 were <br /> advanced to total depths ranging from 24 to 32 feet. Boring locations are depicted on Figures 2a <br /> through 2f. <br /> ' In accordance with the work plan,up to three soil intervals at each boring location were to have been <br /> sampled: (1)the top 10 feet bgs for risk assessment; (2) below 10 feet bgs to assess the magnitude of <br /> COCs in the most-affected soil; and(3)beneath the affected zone to determine the vertical extent. <br /> ' Affected soil was not observed in any boring and groundwater was encountered between 9 to 16 feet bgs; <br /> thus, work plan and CTA guidance were satisfied by sampling(1) one interval at approximately 5 feet bgs <br /> for risk assessment; and(2) one interval just above the top of the groundwater-bearing zone. <br /> ' Groundwater samples were collected from each boring using temporary pre-packed screens and were <br /> shipped to the laboratory for analysis of the COCl. Additional groundwater samples were collected from <br /> borings SB-37 and SB-38 for General Minerals analysis to evaluate suitability of the uppermost <br /> ' groundwater for drinking water use. Separate-phase hydrocarbons and sheen were not observed in any <br /> boring or well. <br /> Soil samples did not contain visibly affected soil, so no fuel-fingerprint samples were collected. <br /> 3.3 INVESTIGATION-DERIVED WASTE (IDW) <br /> SAIC conducted the following for proper storage, characterization, and disposal of IDW: <br /> • Placed all IDW(soil cuttings and unused soil sample,disposable sampling equipment,used <br /> personal protective equipment, and decontamination water) in 55-gallon drums. <br /> ' • Properly labeled, secured, and stored IDW-containing drums on site pending disposal by <br /> Sturgeon &Son, Inc. <br /> ' 4.1 SUBSURFACE CONDITIONS 4. FINDINGS <br /> ' Soils consisted of clay and silt interbedded with poorly graded sand with silt. The five borings did not <br /> contain hydrocarbon-affected soil. Boring logs that describe Unified Soil Classification System soil <br /> characteristics,photo-ionization detector readings, and observations of residual crude oil in soil and/or in <br /> groundwater are provided in Appendix C. <br /> Static water levels were measured in each borehole, and depth to groundwater was noted from 7 to 10 feet <br /> bgs. Surveying the surface elevations of the borings was not a component of the investigation; therefore, <br /> ' the direction and gradient of groundwater movement were not determined. <br /> 4.2 SOIL ANALYTICAL RESULTS <br /> Soil analytical results, PRGs, and ESLs for the COCs are summarized in Tables 1 and 2. A soil data <br /> usability discussion is included in Appendix D as Appendix D.1, and copies of the soil laboratory reports <br /> ' S SME <br /> From Science to Solutions <br />