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Phase 11 Additional Subsurface Investigation Tracy Comers Shopping Center 3225 North Tracy Boulevard Tracy,California 95376 Partner Project Number 14-129814.3 January 27,2015 Page 15 samples appeared to exhibit discoloration or an odor. None of the PID readings suggested the presence of elevated volatile organics concentrations. Groundwater Sampling Methodology After soil sampling to the terminal depth, a temporary monitoring well was installed within the drill rods by advancing the sampler fitted with an expendable steel point to the terminal depth and retracting the rods to expose a steel well screen. Groundwater samples were retrieved from each temporary monitoring well using a new section of 3/8- inch diameter polyethylene tubing fed through a peristaltic pump and conveyed into three hydrochloric acid-preserved volatile organics analysis (VOA) vials. Each vial was filled with no observable headspace or air bubbles to minimize the potential for volatilization, labeled for identification, and stored in an iced cooler. The temporary monitoring wells were removed from the boreholes and each boring was backfilled with concrete and capped with a concrete patch to match surrounding ground cover after completion of sampling. No significant amounts of derived wastes were generated during this investigation. Laboratory Analysis Partner collected nine soil samples and three groundwater samples on January 13, 2015, which were transported in iced-coolers under proper chain-of-custody protocol to SunStar, a state-certified laboratory (California Department of Public Health Environmental Laboratory Accreditation Program certificate number 2250) in Lake Forest, California, for analysis on January 15, 2014. Based on field- screening results, one soil sample per boring (four samples total) and each of the three groundwater samples were analyzed for PCE and daughter compounds (specifically TCE; cis-1,2-DCE; trans-1,2-DCE: and vinyl chloride) in accordance with United States Environmental Protection Agency (EPA) Method 82608. Pertinent Regulatory Agency Guidance The regulatory guidance used by Partner as part of the Phase II Additional Subsurface Investigation is presented below. Water Quality Goals The Central Valley Regional Water Quality Control Board (CVRWQCB) has established Water Quality Goals (WQGs) as an initial screening level evaluation. WQGs aid in assessing the potential threats to human health, terrestrial/aquatic habitats, and/or drinking water resources due to contaminants in groundwater. Under most circumstances,the presence of contamination below applicable WQGs can be assumed to not pose a significant, chronic (i.e., long-term) adverse risk to the applicable receptor of concern. Conversely, sites that exceed WQGs generally require further evaluation and/or remediation. Please note that the WQGs were developed using default assumptions (e.g., standard exposure factors) and, consequently, are only meant for screening level assessments. The WQGs should not be considered enforceable regulatory PARTNER