SITE INFORMATION AND CORRESPONDENCE FILE 2

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{ Nomellini Property December 2013 1045 West Charter Way, Stockton Claim No: 552 Evaluation of Current Risk • Estimate of Hydrocarbon Mass in Soil : None reported. • Soil/Groundwater tested for MTBE: Yes. • Oxygen Concentrations in Soil Vapor: None reported. • Plume Length: Undefined. • Plume Stable or Decreasing : Unknown . • Contaminated Zone(s) Used for Drinking Water: No. • Groundwater Risk from Residual Petroleum Hydrocarbons: The case does not meet the Policy criteria because the extent of groundwater contamination is not defined and the dissolved concentration of benzene is greater than 1 , 000 pg/L. • Indoor Vapor Risk from Residual Petroleum Hydrocarbons: This case does not meet the vapor intrusion criteria of the Policy because the maximum benzene concentration in groundwater is greater than 1 , 000 pg/L while the minimum depth to groundwater is less than 30 feet. • Direct Contact Risk from Residual Petroleum Hydrocarbons : The case meets Policy Criterion 3a. Maximum concentrations in soil are less than those in Policy Table 1 for Commercial use and the concentration limits for a Utility Worker are not exceeded. There are no soil sample results in the case record for naphthalene. However, the relative concentration of naphthalene in soil can be conservatively estimated using the published relative concentrations of naphthalene and benzene in gasoline. Taken from Potter and Simmons (1998) , gasoline mixtures contain approximately 2 percent benzene and 0. 25 percent naphthalene. Therefore, benzene can be directly substituted for naphthalene concentrations with a safety factor of eight. Benzene concentrations from the Site are below the naphthalene thresholds in Policy Table 1 . Therefore, the estimated naphthalene concentrations meet the thresholds in Table 1 and the Policy criteria for direct contact by a factor of eight. It is highly unlikely that naphthalene concentrations in the soil , if any, exceed the threshold . Page 11 of 14