3 - The Bowery_PUBLIC COMMENT (SAFER)

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Case Closure Summary Site Name: Ricoh Electronics Case # 083000552T • Groundwater samples collected on the Jaydee property indicate petroleum fuel concentrations are not at a concentration of concern and are stable. • No further action should be required because the low levels of petroleum hydrocarbons in the soil and groundwater do not pose a health risk. Board staff is recommending site closure for the following reasons: • The USTs have been removed from the site. • A significant volume of the source petroleum hydrocarbons in the soil has been removed. • The residual petroleum hydrocarbons in the soil and groundwater appear not to pose a significant enough risk to groundwater quality or the underlying groundwater's beneficial uses to warrant the expense of further remediation. • It is anticipated that the concentration and mass of residual petroleum hydrocarbons would continue to decline due to biodegration and natural attenuation. • The SARWQCB has not established TPH cleanup levels for soil for protection of human health and, at this time, no statewide TPH cleanup levels have been established. However, the residual concentrations of petroleum hydrocarbons detected in the soil borings do not exceed the environmental screening levels (ESLs) established by the San Francisco RWQCB for direct exposure for commercial workers (450 ppm for soils <3 m deep and 4200 ppm for soils >3 m deep for gasoline and diesel and 3700 ppm for residual fuels with a carbon chain> 24) and the Gross Contamination Ceiling Levels (for odors, etc.) for shallow soils (500 ppm for gasoline and diesel and 2500 ppm for residual fuels). Furthermore, according to Mullin, et al (1990), isoparaffinic hydrocarbon compounds "have a very low order of acute toxicity, being practically non-toxic by oral, dermal and inhalation routes. However, aspiration of liquid isopariffins into the lungs during oral ingestion could result in severe pulmonary injury" and non-evaporative dermal exposure by liquid isopariffins "have produced slight to moderate irritation". Given that no free product isopar is currently being detected at the site, it appears that there is a low likelihood that commercial workers would be exposed to liquid isopar. Based on these criteria, Board staff is not requiring a quantitative risk assessment of the residual petroleum hydrocarbons or vapor intrusion studies to determine if the residual petroleum hydrocarbons pose any risk to the nearby building occupants in the soil at this time. On August 6,2010, five groundwater monitoring wells and two groundwater extraction wells were abandoned on the Ricoh and adjacent JayDee Enterprises properties. If land use changes at the site, a review of the corrective actions may be warranted if on-site excavation or construction activities expose contaminated soil or if changes in land use indicates that the residual contamination at the site poses a risk to site occupants. 4