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locations that are upgradient, cross gradient, and downgradient with respect to the groundwater <br /> flow directions relative to the Quality Cleaners. Initially, the first boring from each pair would be <br /> continuously cored for the purposes of identifying the potential presence of stratum that are coarser <br /> grained and more transmissive in comparison to overlying and underlying strata. Based on the <br /> observations of coarser grained stratum below the bottom of the proposed monitoring well screen <br /> intervals, grab groundwater samples would be collected from targeted stratum with a Hydropunch <br /> groundwater sampling system from within a soil boring advanced proximate to the initial boring. <br /> The location of these proposed borings and the details of the sampling would be included in an <br /> addendum to this Workplan and submitted to the DTSC for concurrence and approval prior to the <br /> commencement of the work. <br /> Petroleum Hydrocarbon Release Assessment <br /> Soil borings will be advanced in the areas inferred to be the potential locations of the 1991 <br /> petroleum hydrocarbon release. Soil and grab groundwater samples from six borings will be <br /> collected to assess whether the petroleum hydrocarbon release and other potential constituents may <br /> have caused an impact that may require additional assessment and/or the installation of <br /> groundwater monitoring wells. Soil gas samples will be collected from two of the four inferred <br /> locations. <br /> Agricultural Pesticides Assessment <br /> As summarized in Section 2.0, there is no obvious evidence from review of the available aerial <br /> photographs that indicate the Site was actively cultivated with crops;the western half of the subject <br /> property historically has been unpaved and not occupied by structures or equipment. However, <br /> off-site areas particularly to the south and northeast of the Site appear to have been actively <br /> cultivated until sometime prior to 1982. <br /> The Site was occupied by what appeared to have been rural and possible farm-related residential <br /> structures with an associated barn, sheds and outbuildings and storage of portable agricultural <br /> equipment. Therefore, while it appears unlikely that environmentally persistent agricultural <br /> pesticides were presumably applied uniformly, for agricultural purposes consistent with normal <br /> application practices, it is possible that environmentally persistent pesticides were historically <br /> stored or mixed proximate to barns, sheds, or outbuildings. <br /> DTSC guidance related to assessing former agricultural properties, including the August 7, 2008 <br /> Interim Guide for Sampling Agricultural Properties (third Revision), specifies that land that has <br /> been graded in preparation for construction with areas that has received fill, or have had parking <br /> lots or structures placed on it following active use as an agricultural field that may have resulted <br /> Sampling and Analysis Workplan <br /> Tracy Corners Shopping Center <br /> 3225 North Tracy Boulevard <br /> Tracy,California 95376 <br /> Partner Project Number SM14-129814 <br /> Docket Number HAS-VCA 14/15-108 <br /> August 15,2016 <br /> Page 20 <br />