WORK PLANS - Laserfiche WebLink

Home Browse Search

I ameO, The primary chemicals contributing to the cumulative cancer risk were carcinogenic PAHs via direct contact to soil, and naphthalene and ethylbenzene via inhalation exposures to indoor air. The primary chemical contributing to the cumulative hazard index was TPHc from direct ' contact. Cumulative theoretical excess lifetime cancer risks and hazard indexes were calculated on a sample-by-sample basis. Several sample locations were above the cumulative target risk level of 1 x10-6 and/or a hazard index of 1 and are summarized below: • For shallow soil sample locations exceeding th p g e commercial/industrial criteria are located along the southwestern boundary (boring locations GMX-09, GMX-25, GMX-31; Figure 5). • For shallow soil, sample locations exceeding the residential criteria are located near the northern, southwestern, and southern boundaries (boring locations GMX-02, GMX-09, GMX-25, GMX-31, and SB-2). • For deep soil, only one sample location exceeded both residential P Y p and commercial criteria for the protection of vapor intrusion. This location is near the northeast corner of ' the property (boring location GXM-13; Figure 5). The Water Board concurred with the SLRA in a letter dated March 26, 2008. In the letter, the Water Board requested "a work plan and time schedule for removal of the affected soil, post- excavation confirmation sampling, and an amended screening level risk assessment" (i.e., a post-remediation risk assessment). 4.0 FUTURE SITE USE The City of Trac General Plan ma shows the Site is zoned for medium density Y p y residential, ' which allows uses other than residential development: "Residential land use designations may also allow for other land use types that serve residents of the 1 community. Examples of uses that may be allowed include places of worship, schools, parks and recreation facilities, fire stations, libraries, day care facilities, and community centers. The precise location of such facilities will be determined upon the submittal of detailed plans for individual properties." From the City of Tracy General Plan, adopted July 20, 2006. Therefore, under current zoning, the Site can be used for non-residential uses that are ' consistent with the commercial/industrial scenario that was evaluated in the SLRA. Based on the results of the SLRA, remediation will be implemented to prepare the Site for future commercial/industrial use by removing impacted soil in the southwestern portion of the Site. ' AMEC Geomatrix Inc I:\Doc_Safe\6000s\6628.001\3000 REPORTS\Excavation Work Plan-8.12.08\1 Text,cover and slips\Text.doc 4