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collected through the hydropunch for analysis of metals will be field filtered prior to water being stored in laboratory provided containers that contain preservatives. Kleinfelder will also assess existing literature for existing data on natural background metal concentrations. Should existing literature be identified, no further field work will be recommended. If, however, existing literature is insufficient to establish natural background conditions, Kleinfelder will collect five slide-hammer surf icial samples from locations identified as passive soil gas survey locations and chosen at random by Kleinfelder. Samples will be analyzed for CAM 17 metals, and concentration distributions will be compared against OU 1 and OU 7 initial Phase ll metal concentrations. If OU 1 and 7 Phase ll metal conditions are elevated above natural background conditions, Kleinfelder will perform distilled-water waste extraction tests (Di WETs) to assess potential metal solubility. If Di WET tests indicate elevated metals are relatively soluble, Kleinfelder will also analyze Hydropunch groundwater samples for CAM 17 metals. Kleinfelder will only recommend remedial work should soil data indicate elevated metal levels above Industrial Thresholds, or if soil data indicate soluble metals above natural background levels. Kleinfelder anticipates that OU 1 metal concentrations will mostly represent natural background levels below Industrial Thresholds and that groundwater concentrations will mostly meet EPA Tap Water and Tier 1 Groundwater ESLs. It is anticipated that such results will indicate that Site soils have not impacted groundwater and that no further action is appropriate. OPERABLE UNIT 2 OU 2 Description OU 2 Corresponds to Sub-Recommendations 9.1 and 10.1, which pertain to former petroleum- related underground storage tanks (USTs) and petroleum-related USTs that appeared on fire insurance maps. The Phase I identified potential for soil contamination via leaks/spills of petroleum-related compounds. Phase II samples were collected and analyzed for petroleum- related compounds. Petroleum: Existing Data Seven soil samples were analyzed for TPH as referenced by gasoline (TPHg) (EPA 8015M/5030), Benzene, Toluene, Ethylbenzene, Xylenes (BTEX) (EPA 8020), Methyl Tertiary Butyl Ether (MtBE) (EPA 8020), Ethylene Dibromide (EDB) (EPA 8010), and organic lead (by LUFT Manual Methods) (Table 0U2-P, soil samples 11-1 through 11-7). These analyses yielded 112 results, of which all are ND except for two xylenes concentrations of 0.0056 and 0.0065 mg/kg. These concentrations are below Industrial Thresholds and Protection of Groundwater SSLs. Most laboratory reporting limits are not tabulated. Those that are tabulated are below Industrial Thresholds but typically above Protection of Groundwater SSLs. In addition, two Hydropunch samples were collected. Both were analyzed for TPHg (EPA 8015M/5030), BTEX) (EPA 8020), MtBE (EPA 8020), and Ethylene Dibromide (EDB) (EPA 8010). One was also sampled for Halogenated VOCs (EPA 8010) (Table 0U2-P, hydropunch samples 11-2-HP and 11-7-HP). These analyses yielded 57 results. All were ND. Reporting limits were tabulated for organic lead, TPHg, purgeable hydrocarbons, and BTEX. All are below associated Tier 1 and EPA Tap Water ESLs, except for benzene, for which the reporting limit of 0.5 ug/L 20173951.001A/SAC17R68420 Page 5 of 26 November 2, 2017 © 2017 Kleinfelder www.kleinfelder.com KLEINFELDER 2882 Prospect Park Dr., Suite 200, Rancho Cordova, CA 95670 p I 916.366-1701 f I 916.366-7013