ARCHIVED REPORTS_2019-MAY 15 SITE ASSESSMENT REPORT

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15 May 2019 AGE Project No. 14-3002 Page 13 of 17 • Barium, copper, molybdenum, selenium, vanadium and zinc were detected in the groundwater samples analyzed at maximum concentrations of 0.480 mg/l, 0.161 mg/l, 0.246 mg/l, 0.178 mg/l, 0.609 mg/l, and 0.070 mg/l. Additionally, chromium was detected in the groundwater sample collected from B6 at a concentration of 0.018 mg/l. Except for selenium detected in B1, all metal concentrations were below their respective MCLs and all metal concentrations were below hazardous waste limits (Table 5). • Hexavalent chromium was detected in the groundwater samples collected from B6, B13, B16, B23, B28 and B31 at concentrations ranging from 0.93 micrograms per liter (µg/l) in B13 to 8.4 µg/l in B6. Hexavalent chromium concentrations were below the last established MCL of 10 µg/l (2014). However, as of 2017, there is no established MCL for hexavalent chromium. Also, the concentrations were significantly below the hazardous waste limit (Table 5). • SVOCs, PAHs, PCBs, and VOCs were not detected above laboratory reporting limits in any of the groundwater samples analyzed (Table 6). • Except for TPH-g detected at the laboratory reporting limit of 50 µg/l in the groundwater sample collected from B40, TPH were not detected above laboratory reporting limits in any of the groundwater samples analyzed (Table 6). • Dioxin/Furans were detected in the groundwater sample collected from B35 at a TEQ concentration of 2.10 picograms per liter (pg/l). Dioxin/Furans were not detected above laboratory reporting limits in the groundwater samples collected from B13 and B16. The concentration detected in B35 was significantly below the MCL of 30 pg/l for dioxin/furans and the congener 2,3,7,8-TCDD was not detected in the sample (Table 6). • Except for the groundwater sample collected from B40, nitrate as nitrogen and nitrate as nitrate were detected in the groundwater samples at maximum concentrations of 36 mg/l nitrate as nitrogen and 160 mg/l nitrate as nitrate in B28. Nitrate as nitrogen concentrations detected in B28 and B35 were above the MCL of 10 mg/l; and nitrate as nitrate concentrations detected in B23, B28, B31 and B35 were above the MCL of 45 mg/l. • Ammonia was detected in samples collected from B13, B16, B23, B28, B31, B35 and B40 at concentrations ranging from 0.22 mg/l in B13 to 2.8 mg/l in B28. There is no established MCL for ammonia. However, environmental limits for ammonia in surface water in the United States range from 0.25 mg/l to 32.5 mg/l (Oregon Public Health Division). • TDS was detected in the water samples at concentrations ranging from 705 mg/l in B16 to 2,590 mg/l in B1. The concentrations were above the secondary MCL of 500 mg/l. Analytical results of groundwater samples are summarized in Tables 5 through 7. The laboratory reports (listed in Section 5.3.), QA/QC reports and chain of custody forms are