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PHASE II ENVIRONMENTAL SITE ASSESSMENT REPORT SATELLITE APARTMENTS APN 139-224-090 530 N. STANISLAUS STREET STOCKTON, SAN JOAQUIN COUNTY, CALIFORNIA EXECUTIVE SUMMARY May 31,2024 Condor Earth(Condor)conducted a Phase II Environmental Site Assessment(ESA)for the property located at 530 North Stanislaus Street located in Stockton, San Joaquin County,California(Site,Figures 1 through 3, Appendix A). The Site comprises approximately 0.55 acres designated as assessor's parcel number (APN) 139-224-090. In a Phase I ESA dated March 27,2024, Condor identified at least five high-risk off- Site properties including automotive repair and dry-cleaning operations that are in close proximity to the Site. Due to the likelihood of chlorinated solvent and petroleum products use, a vapor encroachment condition could not be ruled out for the Site without further investigation.Additionally,exposed soil around the Site's apartment complex perimeter may be impacted by chlorinated pesticides at elevated levels from historical termiticide application. Condor recommended further due diligence with a subsurface soil gas and surface soil investigation to evaluate whether historical uses of on-Site and off-Site properties pose a risk to human health of current and future occupants at the Site. This Phase 11 ESA comprised a screening of Site soil gas for the presence of volatile organic compounds (VOCs) and soils for the presence of chlorinated pesticides(OCPs). Condor conducted the Phase II ESA under contract with Housing Authority of the County of San Joaquin(Client). On May 13,2024, Condor collected two(2)soil gas samples at two locations within the parking lot at five feet below ground surface(bgs),and two(2)soil gas samples beneath the sub slab of the existing apartment complex for analysis of VOCs.Additionally,Condor collected surface soil samples from four(4)locations at each side of the existing apartment complex to be analyzed for OCPs. Groundwater beneath the Site is anticipated to range from approximately 15 to 18 feet bgs and flows toward the east-northeast. None of the VOC concentrations in soil gas exceeded calculated soil vapor screening levels(using a default attenuation factor of 0.03), except for benzene in ASG-1 at 5 feet bgs (13 micrograms per cubic meter [µg/m3])and chloroform in sub-slab sample Sub-2(7.2 µg/m3). Benzene, toluene, ethyl benzene and xylenes (BTEX) were detected in both ASG-1 and ASG-2 at 5 feet bgs, with concentrations decreasing towards the west (opposite direction from Grant Street and the adjoining motor vehicle repair complex to the east). It is likely the that automotive complex is the source of BTEX contamination in soil gas. For this reason, Condor compared the benzene concentrations to the State Water Resources Control Board's(State Water Board)Low-Threat Underground Storage Tank Case Closure Policy's (LTCP, 2012) no bioattenuation zone soil gas criteria to evaluate the human health risk associated with benzene for future occupants at the Site. Assuming no bioattenuation is applicable to Site conditions (the more conservative assumption),the screening level for benzene is 85 µg/m3 for residential use,which is above the highest concentration of benzene at 13 µg/m3. Chloroform in the Sub-2 sub-slab soil gas sample (7.2 µg/m3) exceeds the calculated soil vapor screening level of 4.0 µg/m3. It is Condor's opinion that it is unlikely that the chloroform in soil gas at the Site poses ii R /► CONDOR