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n NRevised Site Investigation Report & Case Closure Request Country Market 10476 West Linne Road, Tracy, California Antea Group Project No. CTRVMKTUST a ntea g ro u p 3.3.2 Dissolved-Phase Benzene in Groundwater Dissolved-phase benzene was not detected in groundwater beneath the site. 3.4 Direct Contact and Outdoor Air Exposure This section reviews SB 2012-0016 criteria associated with direct contact and outdoor air exposure. Per SB 2012-0016 direct contact and outdoor air exposure is influenced by contamination found in soils from 0- to 10 feet bgs and the primary constituents of concern are benzene, ethylbenzene and naphthalene. Amongstthe soil samples collected at the site, ethylbenzene was only reported In Tank-13 9' at 226 µg/kg, below the SB 2012-0016 thresholds for commercial property, residential property and utility workers. Benzene was not reported in the soil samples analyzed at the site. 4.0 CONCLUSIONS AND RECOMMENDATIONS Based on the February 28, 2014-soil and groundwater sampling event, and on the results of soil samples collected in 2012 by Jim Thorpe Inc., Antea Group concludes the following: • Petroleum hydrocarbons reported in soil during removal of the USTs are laterally and vertically limited in extent and do not threaten groundwater beneath the site. Antea Group concludes the following with regard to this Case Closure Request: • Petroleum hydrocarbons beneath the site are limited to soil and are not a source of groundwater contamination. The on-site sensitive receptor has not been affected. • The secondary source of residual petroleum hydrocarbons in soil is minimal and likely to naturally attenuate within a reasonable time period. • Due to the absence of LNAPL and benzene in soil and groundwater, vapor intrusion to indoor air does not pose a threat to human health at the site. • Within the top ten feet of soil, benzene is not present and _ethy_Ipenzene was only detected in one sample at a concentration below the SB 2012-0016 threshold suggesting there is little risk to human health or the environment from direct contact or outdoor air exposure. Antea Group therefore recommends that the site be closed and no further action be required. Upon regulatory agreement, all notification requirements required for case closure under SB 2012-0016 will be met. 7 www,anteagroup.com