SITE INFORMATION AND CORRESPONDENCE_FILE 1

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leaching or percolation is unlikely. This interpretation is based on the fact that the property is capped with an asphalt surface and hydrocarbon impact has not been identified within vadose or capillary ffinge soils. Acceptable soil concentrations per The Designated Level Methodologyfor Waste Classification and Cleanup Level Determination are proposed below: • Benzene = 0.01 milligrams per kilogram (mg/kg) • Toluene = 0.42 mg/kg • Ethylbenzene = 0.29 mg/kg • Xylenes = 0.17 mg/kg • TPH-g = 10 mg/kg Acceptable soil concentrations are a function of water quality goals associated with the resid- ual plume area. This is based on using an environmental attenuation factor of 1 and a leach- ability factor of 10. This assumption was made to establish conservative soil cleanup goals. The aforementioned goals apply to the site during remediation and beyond; however, they may be modified at any time if it can be shown that changes: • are consistent with the maximum benefit to the people of the State; and, • will not unreasonably affect present or probable future beneficial uses of groundwater. For example, at some point in the future it may be advantageous to modify the stated water quality goals. This would be done by showing that the modified goals meet the conditions above. 3.2 Site Public Health and Safety Goals According to guidance presented in Title 23, Chapter 16, Article 11 of the CCR, any reme- diation approach considered must be designed to mitigate nuisance conditions and risk of fire or explosion posed by residual impact. To assure remedial objectives address the require- ments of Article 11, site-specific public health and safety goals are necessary. The site-specific goal is to eliminate any threat to public health and safety associated with subsur- face petroleum hydrocarbon impact, including the potential threat posed by nuisance condi- tions and risk of fire or explosion. Additionally, use of, or exposure to impacted groundwater or soil will be restricted. 3201357B/CAPREVI 8 June 29, 1995