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RBSS_Tables_Final_20160212This page intentionally left blank Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Table 2-1 Summary of Horizontal Hydraulic Gradient Calculations (Round 2) Well Pair Groundwater Elevation — Upgradient Well Groundwater Elevation — Down -gradient Well Flow Path Length Horizontal Hydraulic Gradient (hz) (hi) (dn (i) Regolith (S wells) MW-8S / MW-9 NM 647.13 1936' NA AB-4S / MW- 11 SR 704.28 Dry 1584' NA AB-3S / GWA- 9S 704.78 645.11 1364' 0.043 MW-7SR / BG- 3S NA 642.13 2596' NA Average Horizontal Hydraulic Gradient 0.043 Transition Zone (D wells) MW-8D / MW- 9D NM 644.36 1936' NA A134D / MW- 11 DR 701.2 662.8 1584' 0.024 AB-3D / GWA- 9D 699.67 643.06 1364' 0.042 MW-7D / BG-3D 712.4 639.73 2596' 0.028 Average Horizontal Hydraulic Gradient 0.031 Fractured Bedrock (BR wells) GWA-23BR / MW- 9BR 696.56 645.21 1936' 0.027 GWA-23BR / A13-3BR 696.56 683.75 3300' 0.004 GWA-26R / GWA- 9BR 639.01 538.78 3168' 0.032 Average Horizontal Hydraulic Gradient 0.021 NM = Not Measured NA = Not Available Depth to Water measurements collected on 9/15/15 Table 2-2 Comparison of 0.45 Micron and 0.1 Micron Filter Sample Results - Groundwater Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Sample Location Sample Location Sample Location AB-2D AB-2S AB-3BR Constituent CAS RN Fraction Unit 0.45 µm Result 0.1 µm Result RPD (%) 0.45 µm Result 0.1 µm Result RPD (%) 0.45 µm Result 0.1 µm Result RPD (%) Aluminum 7429-90-5 D /L 100 U 100 U ND/NA 100 U 70 J ND/NA 98 J 270 93.48 Antimony 7440-36-0 D /L 0.65 0.59 -9.68 0.39 J 0.36 J -8 2.5 2.9 14.81 Arsenic 7440-38-2 D /L 0.44 J 0.44 J 0 0.21 J 0.21 J 0 1.2 1.2 0 Barium 7440-39-3 D /L 16 16 0 35 35 0 7.1 8.5 17.95 Beryllium 7440-41-7 D /L 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA Boron 7440-42-8 D /L 340 340 0 50 U 50 U ND/NA 50 U 50 U ND/NA Cadmium 7440-43-9 D /L 0.08 U 0.08 U ND/NA 0.03 J 0.03 J 0 0.08 U 0.08 U ND/NA Chromium 7440-47-3 D /L 3.8 3.4 -11.11 0.56 J+ 0.55 J+ -1.8 0.37 J 4.6 170.22 Cobalt 7440-48-4 D /L 0.5 U 0.5 U ND/NA 32.1 30.8 -4.13 0.5 U 0.5 U ND/NA Copper 7440-50-8 D /L 11.5 J+ 0.69 J+ -73.97 6.4 1.6 J+ -120 0.411 1 83.69 Iron 7439-89-6 D /L 50 U 50 U ND/NA 50 U 150 ND/NA 50 U 62 ND/NA Lead 7439-92-1 D /L 0.15 0.1 U ND/NA 0.55 0.07 J -154.84 0.11 0.18 48.28 Manganese 7439-96-5 D /L 5 U 5 U ND/NA 830 830 0 5 U 3.61 ND/NA Mercury 7439-97-6 D /L 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA Molybdenum 7439-98-7 D /L 12.4 2.3 -4.26 0.5 U 0.5 U ND/NA 4 3.9 -2.53 Nickel 7440-02-0 D /L 0.39 J+ 0.42 J+ 7.41 4.6 4.3 -6.74 0.59 3.2 137.73 Selenium 7782-49-2 D /L 0.2 J 0.5 U ND/NA 1.5 1.5 0 20.2 18.3 -9.87 Strontium 7440-24-6 D /L 200 200 0 24 24 0 190 200 5.13 Thallium 7440-28-0 D /L 0.1 U 0.1 U ND/NA 0.039 J 0.037 J -5.26 0.1 U 0.1 U ND/NA Vanadium 7440-62-2 ID /L 18.9 18.6 -3.43 1 U 11 U ND/NA 22.2 121.3 -4.14 Zinc 7440-66-6 ID /L 122 J+ Ito U ND/NA 90 184 -6.9 6.3 J 116 87 Notes: = RPD greater than 20% pg/L = micrograms per liter pm = micron RPD (%) = relative percent difference ND/NA = not detected/not applicable U = not detected J- = estimated concentration, biased low J = laboratory estimated concentration J+ = estimated concentration, biased high Page 1 of 11 Table 2-2 Comparison of 0.45 Micron and 0.1 Micron Filter Sample Results - Groundwater Sample Location Sample Location Sample Location AB-31D AB-5D AB-6BRU Constituent CAS RN Fraction Unit 0.45 µm Result 0.1 µm Result RPD (%) 0.45 µm Result 0.1 µm Result RPD (%) 0.45 µm Result 0.1 µm Result RPD (%) Aluminum 7429-90-5 D /L 630 710 11.94 150 440 98.31 100 U 100 U ND/NA Antimony 7440-36-0 D /L 0.76 1 27.27 3.2 3.2 0 5.7 5.4 -5.41 Arsenic 7440-38-2 D /L 0.24 J 0.22 J -8.7 0.24 J 0.3 J 22.22 0.15 J 0.14 J -6.9 Barium 7440-39-3 D /L 94 98 4.17 28 29 3.51 20 17 -16.22 Beryllium 7440-41-7 D /L 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA Boron 7440-42-8 D /L 150 U 50 U ND/NA 200 200 0 430 440 2.3 Cadmium 7440-43-9 D /L 0.08 U 0.08 U ND/NA 0.08 U 0.08 U ND/NA 0.08 U 0.08 U ND/NA Chromium 7440-47-3 D /L 23.5 23.2 -1.28 2.6 3.6 32.26 1.1 1.2 8.7 Cobalt 7440-48-4 D /L 0.5 U 0.5 U ND/NA 0.5 U 0.5 U ND/NA 0.5 U 0.5 U ND/NA Copper 7440-50-8 D /L 5.5 3.7 -39.13 0.24 J 1.9 155.14 1 U 1 U ND/NA Iron 7439-89-6 D /L 169 50 U ND/NA 50 U 33 J ND/NA 50 U 50 U ND/NA Lead 7439-92-1 D /L 0.39 0.08 J -131.91 0.1 U 0.059 J ND/NA 0.1 U 0.1 U ND/NA Manganese 7439-96-5 D /L 5 U 5 U ND/NA 5 U 5 U ND/NA 5 U 5 U ND/NA Mercury 7439-97-6 D /L 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA Molybdenum 7439-98-7 D /L 23.8 22.4 -6.06 3.9 3.9 0 5.2 5 -3.92 Nickel 7440-02-0 D /L 1.2 0.83 -36.45 0.21 J 0.71 108.7 0.17 J 0.32 J 61.22 Selenium 7782-49-2 D /L 1.6 1.5 -6.45 0.3 J 0.24 J -22.22 0.52 0.53 1.9 Strontium 7440-24-6 D /L 1800 1900 5.41 390 J- 390 J- 0 490 460 -6.32 Thallium 7440-28-0 D /L 0.1 U 0.016 J ND/NA 0.1 U 0.1 U ND/NA 0.1 U 0.1 U ND/NA Vanadium 7440-62-2 ID /L 113.5 112.8 -5.32 12.6 112.5 -0.8 9.3 19.3 0 Zinc 7440-66-6 ID /L 16.3 J 13.2 J -65.26 10 U 110 U ND/NA 10 U Ito U ND/NA Notes: = RPD greater than 20% pg/L = micrograms per liter pm = micron RPD (%) = relative percent difference ND/NA = not detected/not applicable U = not detected J- = estimated concentration, biased low J = laboratory estimated concentration J+ = estimated concentration, biased high Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Page 2 of 11 Table 2-2 Comparison of 0.45 Micron and 0.1 Micron Filter Sample Results - Groundwater Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Sample Location Sample Location Sample Location AB-6S AB-71D AB-7I Constituent CAS RN Fraction Unit 0.45 µm Result 0.1 µm Result RPD (%) 0.45 µm Result 0.1 µm Result RPD (%) 0.45 µm Result 0.1 µm Result RPD (%) Aluminum 7429-90-5 D /L 260 250 -3.92 810 810 0 100 U 610 ND/NA Antimony 7440-36-0 D /L 0.39 J 0.46 J 16.47 2.4 J+ 2.2 J+ -8.7 0.61 0.66 7.87 Arsenic 7440-38-2 D /L 0.68 0.69 1.46 2.7 2.6 -3.77 0.5 U 0.22 J ND/NA Barium 7440-39-3 D /L 6.8 7.1 4.32 29 29 0 36 46 24.39 Beryllium 7440-41-7 D /L 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA Boron 7440-42-8 D /L 150 U 38 J ND/NA 50 U 50 U ND/NA 50 U 50 U ND/NA Cadmium 7440-43-9 D /L 0.08 U 0.08 U ND/NA 0.08 U 0.08 U ND/NA 0.08 U 0.08 U ND/NA Chromium 7440-47-3 D /L 1.2 0.33 J -113.73 24 23.1 -3.82 0.47 J 0.74 44.63 Cobalt 7440-48-4 D /L 0.45 J 0.42 J -6.9 0.5 U 0.5 U ND/NA 1.3 2 42.42 Copper 7440-50-8 D /L 4.6 0.35 J -171.72 1.5 1.1 -30.77 2 0.86 J -79.72 Iron 7439-89-6 D /L 50 U 50 U ND/NA 50 U 50 U ND/NA 50 U 220 ND/NA Lead 7439-92-1 D /L 0.71 0.046 J -175.66 0.2 0.1 U ND/NA 0.21 0.27 25 Manganese 7439-96-5 D /L 170 170 0 5 U 5 U ND/NA 84 120 35.29 Mercury 7439-97-6 D /L 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA Molybdenum 7439-98-7 D /L 4.2 4.3 2.35 8.1 7.7 -5.06 0.5 U 0.5 U ND/NA Nickel 7440-02-0 D /L 3.2 3.1 -3.17 0.5 U 0.5 U ND/NA 0.71 0.88 21.38 Selenium 7782-49-2 D /L 0.57 0.64 11.57 0.66 0.6 -9.52 0.5 U 0.5 U ND/NA Strontium 7440-24-6 D /L 48 49 2.06 260 260 0 34 37 8.45 Thallium 7440-28-0 D /L 0.026 J 0.027 J 3.77 0.1 U 0.1 U ND/NA 0.017 J 0.022 J 25.64 Vanadium 7440-62-2 ID /L 17.2 17.4 2.74 44.8 143.5 -2.94 1 U 10.39 J ND/NA Zinc 7440-66-6 ID /L 15.3 J 12.5 J 1 -71.79 10 15.6 J -56.41 13 J+ 114 J+ 7.41 Notes: = RPD greater than 20% pg/L = micrograms per liter pm = micron RPD (%) = relative percent difference ND/NA = not detected/not applicable U = not detected J- = estimated concentration, biased low J = laboratory estimated concentration J+ = estimated concentration, biased high Page 3 of 11 Table 2-2 Comparison of 0.45 Micron and 0.1 Micron Filter Sample Results - Groundwater Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Sample Location Sample Location Sample Location AS -ID AS -IS AS-21D Constituent CAS RN Fraction Unit 0.45 µm Result 0.1 µm Result RPD (%) 0.45 µm Result 0.1 µm Result RPD (%) 0.45 µm Result 0.1 µm Result RPD (%) Aluminum 7429-90-5 D /L 3000 3000 0 100 U 59 J ND/NA 550 510 -7.55 Antimony 7440-36-0 D /L 3.7 4 7.79 0.29 J 0.5 53.16 2.6 2.6 0 Arsenic 7440-38-2 D /L 0.39 J 0.41 J 5 1.9 1.6 -17.14 0.28 J 0.29 J 3.51 Barium 7440-39-3 D /L 50 49 -2.02 91 84 -8 28 27 -3.64 Beryllium 7440-41-7 D /L 0.111 0.092 J -17.82 0.2 U 0.14 J ND/NA 0.2 U 0.2 U ND/NA Boron 7440-42-8 D /L 150 U 50 U ND/NA 2000 1700 -16.22 50 U 50 U ND/NA Cadmium 7440-43-9 D /L 0.08 U 0.08 U ND/NA 0.055 J 0.053 J -3.7 0.08 U 0.08 U ND/NA Chromium 7440-47-3 D /L 838 826 -1.44 0.17 J 0.36 J 71.7 17 17.2 1.17 Cobalt 7440-48-4 D /L 0.15 J 0.13 J -14.29 5.4 6.8 22.95 0.5 U 0.5 U ND/NA Copper 7440-50-8 D /L 22.3 19.3 -14.42 1.7 12.1 150.72 2.6 J+ 1.4 J+ -60 Iron 7439-89-6 D /L 138 J 50 U ND/NA 50 U 50 U ND/NA 38 J 50 U ND/NA Lead 7439-92-1 D /L 0.12 0.1 -18.18 0.1 U 0.1 U ND/NA 0.1 U 0.1 U ND/NA Manganese 7439-96-5 D /L 5 U 5 U ND/NA 2300 2400 4.26 5 U 5 U ND/NA Mercury 7439-97-6 D /L 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA Molybdenum 7439-98-7 D /L 54 54.9 1.65 213 187 -13 10 10 0 Nickel 7440-02-0 D /L 0.42 J 0.43 J 2.35 1.4 1.3 -7.41 0.25 J+ 0.5 UJ ND/NA Selenium 7782-49-2 D /L 1.2 1.2 0 0.34 J 0.42 J 21.05 0.89 0.88 -1.13 Strontium 7440-24-6 D /L 710 700 -1.42 3000 2600 -14.29 400 390 -2.53 Thallium 7440-28-0 D /L 0.1 U 0.1 U ND/NA 0.056 J 0.06 J 6.9 0.1 U 0.1 U ND/NA Vanadium 7440-62-2 ID /L 116.1 116.7 3.66 0.73 J 10.73 J 0 39.5 139.8 0.76 Zinc 7440-66-6 ID /L 112 Ill 1 -8.7 6.5 J 120 1 101.89 4.5 J+ 110 U ND/NA Notes: = RPD greater than 20% pg/L = micrograms per liter pm = micron RPD (%) = relative percent difference ND/NA = not detected/not applicable U = not detected J- = estimated concentration, biased low J = laboratory estimated concentration J+ = estimated concentration, biased high Page 4 of 11 Table 2-2 Comparison of 0.45 Micron and 0.1 Micron Filter Sample Results - Groundwater Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Sample Location Sample Location Sample Location AS- 2S AS-3 D AS-3SA Constituent CAS RN Fraction Unit 0.45 µm Result 0.1 µm Result RPD (%) 0.45 µm Result 0.1 µm Result RPD (%) 0.45 µm Result 0.1 µm Result RPD (%) Aluminum 7429-90-5 D /L 100 U 63 J ND/NA 220 210 -4.65 450 460 2.2 Antimony 7440-36-0 D /L 0.17 J 0.21 J 21.05 1.3 0.64 J -68.04 0.48 J 0.48 J 0 Arsenic 7440-38-2 D /L 0.25 J 0.32 J 24.56 0.86 0.81 -5.99 0.22 J 0.22 J 0 Barium 7440-39-3 D /L 93 96 3.17 19 22 14.63 45 46 2.2 Beryllium 7440-41-7 D /L 0.12 J 0.15 J 22.22 0.2 U 0.2 U ND/NA 0.1 J 0.093 J -7.25 Boron 7440-42-8 D /L 50 U 50 U ND/NA 50 U 50 U ND/NA 940 940 0 Cadmium 7440-43-9 D /L 0.12 0.15 22.22 0.08 U 0.08 U ND/NA 0.1 0.1 0 Chromium 7440-47-3 D /L 0.31 J+ 1.8 J+ 141.23 14.8 13.1 -12.19 0.44 J 0.4 J -9.52 Cobalt 7440-48-4 D /L 8 8.5 6.06 0.5 U 0.5 U ND/NA 12.2 12.3 0.82 Copper 7440-50-8 D /L 10.66 J+ 1.7 J+ 88.14 0.85 J+ 0.58 J+ -37.76 2.9 2.5 -14.81 Iron 7439-89-6 D /L 500 500 0 50 U 50 U ND/NA 50 U 50 U ND/NA Lead 7439-92-1 D /L 0.1 0.45 127.27 0.1 U 0.1 U ND/NA 0.1 U 0.1 U ND/NA Manganese 7439-96-5 D /L 460 460 0 3.6 J 4.21 15.38 1200 1200 0 Mercury 7439-97-6 D /L 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA 0.18 J 0.2 U ND/NA Molybdenum 7439-98-7 D /L 10.5 U 0.2 J ND/NA 15.7 14.1 -10.74 0.5 U 0.13 J ND/NA Nickel 7440-02-0 D /L 1.7 J+ 2.4 J+ 34.15 0.31 J+ 0.24 J+ -25.45 2.7 2.8 3.64 Selenium 7782-49-2 D /L 0.5 U 0.5 U ND/NA 0.5 J 0.46 J -8.33 1.3 1.3 0 Strontium 7440-24-6 D /L 75 76 1.32 130 120 -8 9.8 9.4 -4.17 Thallium 7440-28-0 D /L 0.044 J 0.063 J 35.51 0.1 U 0.1 U ND/NA 0.033 J 0.032 J -3.08 Vanadium 7440-62-2 ID /L 10.35 J 11.9 137.78 16 114.4 -10.53 1 U it U ND/NA Zinc 7440-66-6 ID /L 15.8 J+ 15.6 J+ -3.51 3.4 J+ 2.8 J+ -19.35 31 128 1 -10.17 Notes: = RPD greater than 20% pg/L = micrograms per liter pm = micron RPD (%) = relative percent difference ND/NA = not detected/not applicable U = not detected J- = estimated concentration, biased low J = laboratory estimated concentration J+ = estimated concentration, biased high Page 5 of 11 Table 2-2 Comparison of 0.45 Micron and 0.1 Micron Filter Sample Results - Groundwater Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Sample Location Sample Location Sample Location C-2113 C-2S GWA-21BR Constituent CAS RN Fraction Unit 0.45 µm Result 0.1 µm Result RPD (%) 0.45 µm Result 0.1 µm Result RPD (%) 0.45 µm Result 0.1 µm Result RPD (%) Aluminum 7429-90-5 D /L 56 J 100 U ND/NA 1700 2000 16.22 100 U 100 U ND/NA Antimony 7440-36-0 D /L 0.49 J 0.31 -48.1 0.5 U 0.52 ND/NA 0.5 U 0.5 U ND/NA Arsenic 7440-38-2 D /L 0.95 0.76 -22.22 1.2 1.2 0 0.26 J 0.22 J -16.67 Barium 7440-39-3 D /L 23 22 -4.44 37 37 0 20 21 4.88 Beryllium 7440-41-7 D /L 0.2 U 0.2 U ND/NA 2 1.8 -10.53 0.2 U 0.2 U ND/NA Boron 7440-42-8 D /L 150 U 50 U ND/NA 170 170 0 50 U 50 U ND/NA Cadmium 7440-43-9 D /L 0.08 U 0.08 U ND/NA 0.17 0.16 -6.06 0.08 U 0.08 U ND/NA Chromium 7440-47-3 D /L 2.1 1.9 -10 8.2 4.6 -56.25 1.3 0.81 -46.45 Cobalt 7440-48-4 D /L 0.5 U 0.5 U ND/NA 32.5 32.7 0.61 0.16 J 0.14 J -13.33 Copper 7440-50-8 D /L 6.7 0.77 J -158.77 5.4 6.2 13.79 1 U 1 U ND/NA Iron 7439-89-6 D /L 150 U 50 U ND/NA 69 140 67.94 50 U 50 U ND/NA Lead 7439-92-1 D /L 0.7 0.1 U ND/NA 0.14 0.18 25 0.1 U 0.1 U ND/NA Manganese 7439-96-5 D /L 6.4 6.1 -4.8 590 610 3.33 28 28 0 Mercury 7439-97-6 D /L 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA Molybdenum 7439-98-7 D /L 0.73 0.57 -24.62 0.16 J 0.5 U ND/NA 2.5 2.4 -4.08 Nickel 7440-02-0 D /L 0.8 0.64 -22.22 30.2 26.6 -12.68 0.66 0.56 -16.39 Selenium 7782-49-2 D /L 0.5 U 0.5 U ND/NA 2.5 2.6 3.92 0.5 U 0.5 U ND/NA Strontium 7440-24-6 D /L 180 160 -11.76 540 540 0 160 160 0 Thallium 7440-28-0 D /L 0.1 U 0.1 U ND/NA 0.08 J 0.076 J -5.13 0.1 U 0.1 U ND/NA Vanadium 7440-62-2 ID /L 17.5 16.5 -14.29 1 U 11 U ND/NA 14.7 14.6 -2.15 Zinc 7440-66-6 ID /L 12.6 J Ito U ND/NA 85 173 1 -15.19 2.6 J+ 15.4 J+ 70 Notes: = RPD greater than 20% pg/L = micrograms per liter pm = micron RPD (%) = relative percent difference ND/NA = not detected/not applicable U = not detected J- = estimated concentration, biased low J = laboratory estimated concentration J+ = estimated concentration, biased high Page 6 of 11 Table 2-2 Comparison of 0.45 Micron and 0.1 Micron Filter Sample Results - Groundwater Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Sample Location Sample Location Sample Location GWA-21D GWA-21S GWA-23BR Constituent CAS RN Fraction Unit 0.45 µm Result 0.1 µm Result RPD (%) 0.45 µm Result 0.1 µm Result RPD (%) 0.45 µm Result 0.1 µm Result RPD (%) Aluminum 7429-90-5 D /L 100 U 3000 ND/NA 100 U 100 U ND/NA 340 J+ 1800 136.45 Antimony 7440-36-0 D /L 0.5 U 0.5 U ND/NA 0.5 U 0.5 U ND/NA 1.8 2.5 32.56 Arsenic 7440-38-2 D /L 0.18 J 0.13 J -32.26 0.5 U 0.5 U ND/NA 0.11 J 1.1 163.64 Barium 7440-39-3 D /L 9.5 15 44.9 69 71 2.86 180 J+ 170 -5.71 Beryllium 7440-41-7 D /L 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA 0.2 U 0.1 J ND/NA Boron 7440-42-8 D /L 50 U 50 U ND/NA 50 U 50 U ND/NA 50 U 50 U ND/NA Cadmium 7440-43-9 D /L 0.08 U 0.08 U ND/NA 0.029 J 0.08 U ND/NA 0.08 U 0.08 U ND/NA Chromium 7440-47-3 D /L 1.5 J+ 5.3 111.76 0.29 J 0.27 J -7.14 8.9 27.7 102.73 Cobalt 7440-48-4 D /L 0.5 U 1.5 ND/NA 4.5 4.7 4.35 0.5 U 0.66 ND/NA Copper 7440-50-8 D /L 0.44 J+ 9.1 181.55 10.1 0.68 J -174.77 1.3 4 101.89 Iron 7439-89-6 D /L 150 U 600 ND/NA 50 U 50 U ND/NA 50 U 860 ND/NA Lead 7439-92-1 D /L 0.1 U 0.1 J+ ND/NA 1.1 0.1 U ND/NA 0.12 1.1 160.66 Manganese 7439-96-5 D /L 7.8 38 131.88 440 440 0 5 U 27 ND/NA Mercury 7439-97-6 D /L 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA Molybdenum 7439-98-7 D /L 3.6 3.4 -5.71 0.5 U 0.5 U ND/NA 6.9 8.5 20.78 Nickel 7440-02-0 D /L 0.62 J+ 2.4 J+ 117.88 1.4 1.5 6.9 0.86 22.4 185.21 Selenium 7782-49-2 D /L 0.38 J 0.47 J 21.18 0.5 U 0.5 U ND/NA 0.22 J 0.26 J 16.67 Strontium 7440-24-6 D /L 170 200 16.22 2.6 J 2.73 1 3.77 1200 J+ 1100 -8.7 Thallium 7440-28-0 D /L 0.1 U 0.018 J+ ND/NA 0.079 J 0.083 J 4.94 0.037 J 0.071 J 62.96 Vanadium 7440-62-2 ID /L 16.2 19.4 41.03 1 U 11 U ND/NA 2.8 110.3 114.5 Zinc 7440-66-6 ID /L 13.4 J+ 12.7 J+ -22.95 11 J+ Ill J+ 0 12 114 1 15.38 Notes: = RPD greater than 20% pg/L = micrograms per liter pm = micron RPD (%) = relative percent difference ND/NA = not detected/not applicable U = not detected J- = estimated concentration, biased low J = laboratory estimated concentration J+ = estimated concentration, biased high Page 7 of 11 Table 2-2 Comparison of 0.45 Micron and 0.1 Micron Filter Sample Results - Groundwater Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Sample Location Sample Location Sample Location GWA-23D GWA-23S GWA-61D Constituent CAS RN Fraction Unit 0.45 µm Result 0.1 µm Result RPD (%) 0.45 µm Result 0.1 µm Result RPD (%) 0.45 µm Result 0.1 µm Result RPD (%) Aluminum 7429-90-5 D /L 600 600 0 100 U 57 J ND/NA 1600 1700 6.06 Antimony 7440-36-0 D /L 0.5 U 0.15 J ND/NA 0.5 U 0.5 U ND/NA 4.3 4.6 6.74 Arsenic 7440-38-2 D /L 0.78 0.81 3.77 0.5 U 0.5 U ND/NA 0.59 0.86 37.24 Barium 7440-39-3 D /L 14 14 0 31 31 0 30 31 3.28 Beryllium 7440-41-7 D /L 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA Boron 7440-42-8 D /L 150 U 50 U ND/NA 50 U 50 U ND/NA 50 U 50 U ND/NA Cadmium 7440-43-9 D /L 0.08 U 0.08 U ND/NA 0.026 J 0.08 U ND/NA 0.08 U 0.08 U ND/NA Chromium 7440-47-3 D /L 39.1 34.9 -11.35 0.61 0.54 -12.17 26.1 28.1 7.38 Cobalt 7440-48-4 D /L 0.5 U 0.5 U ND/NA 3.3 3.3 0 0.5 U 0.33 J ND/NA Copper 7440-50-8 D /L 3.7 1.6 -79.25 14.7 3.8 -117.841.7 4.4 88.52 Iron 7439-89-6 D /L 50 U 50 U ND/NA 27 J 34 J 22.95 50 U 120 J+ ND/NA Lead 7439-92-1 D /L 0.57 0.057 J -163.64 1.5 0.13 -168.1 0.1 0.12 18.18 Manganese 7439-96-5 D /L 5 U 5 U ND/NA 86 86 0 5 U 5.2 ND/NA Mercury 7439-97-6 D /L 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA Molybdenum 7439-98-7 D /L 5 3.8 -27.27 0.5 U 0.5 U ND/NA 10.9 10.8 -0.92 Nickel 7440-02-0 D /L 2.4 1.3 -59.46 2.3 2.6 12.24 0.5 U 2.2 ND/NA Selenium 7782-49-2 D /L 0.21 J 0.29 J 32 0.5 U 0.5 U ND/NA 0.51 0.54 5.71 Strontium 7440-24-6 D /L 210 210 014 13 -7.41220 220 0 Thallium 7440-28-0 D /L 0.1 U 0.1 U ND/NA 0.016 J 0.1 U ND/NA 0.1 U 0.1 U ND/NA Vanadium 7440-62-2 ID /L 133.2 131 -6.85 1 U 11 U ND/NA 20.8 121.9 5.15 Zinc 7440-66-6 ID /L 14 J+ Ito U ND/NA 32 J+ 129 J+ -9.84 120 8.7 J+ -172.96 Notes: = RPD greater than 20% pg/L = micrograms per liter pm = micron RPD (%) = relative percent difference ND/NA = not detected/not applicable U = not detected J- = estimated concentration, biased low J = laboratory estimated concentration J+ = estimated concentration, biased high Page 8 of 11 Table 2-2 Comparison of 0.45 Micron and 0.1 Micron Filter Sample Results - Groundwater Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Sample Location Sample Location Sample Location GWA-6S GWA-91D GWA-9S Constituent CAS RN Fraction Unit 0.45 µm Result 0.1 µm Result RPD (%) 0.45 µm Result 0.1 µm Result RPD (%) 0.45 µm Result 0.1 µm Result RPD (%) Aluminum 7429-90-5 D /L 110 57 J -63.47 100 U 100 U ND/NA 100 U 56 J ND/NA Antimony 7440-36-0 D /L 0.23 J ND/NA 0.5 UJ 0.5 UJ ND/NA 0.5 UJ 0.5 UJ ND/NA Arsenic 7440-38-2 D /L 0.33 J ND/NA 0.5 U 0.5 U ND/NA 0.5 U 0.5 U ND/NA Barium 7440-39-3 D /L 53 52 -1.9 6.6 6.9 4.44 26 28 7.41 Beryllium 7440-41-7 D /L 0.2 U ND/NA 0.2 U 0.2 U ND/NA 0.082 J 0.074 J -10.26 Boron 7440-42-8 D /L 150 U 50 U ND/NA 250 270 7.69 280 300 6.9 Cadmium 7440-43-9 D /L 0.18 ND/NA 0.08 U 0.08 U ND/NA 0.08 U 0.08 U ND/NA Chromium 7440-47-3 D /L 1.1 ND/NA 0.35 J 0.47 J 29.27 0.5 J 0.35 J -35.29 Cobalt 7440-48-4 D /L 24.5 ND/NA 0.17 J 0.17 J 0 44.7 43.2 -3.41 Copper 7440-50-8 D /L 2.3 ND/NA 0.4 J 1 U ND/NA 2.2 1.3 -51.43 Iron 7439-89-6 D /L 141 J+ 50 U ND/NA 29 J 50 U ND/NA 50 U 50 U ND/NA Lead 7439-92-1 D /L 0.14 ND/NA 0.15 0.1 U ND/NA 0.22 0.13 -51.43 Manganese 7439-96-5 D /L 1300 1200 -8 26 27 3.77 2600 2700 3.77 Mercury 7439-97-6 D /L 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA Molybdenum 7439-98-7 D /L 0.5 U ND/NA 0.111 0.11 -9.52 0.5 U 0.5 U ND/NA Nickel 7440-02-0 D /L 6.8 ND/NA 0.31 J 0.6 63.74 2 1.9 -5.13 Selenium 7782-49-2 D /L 0.5 U ND/NA 0.5 U 0.5 U ND/NA 0.22 J 0.5 U ND/NA Strontium 7440-24-6 D /L 13 13 0 100 100 0 27 26 -3.77 Thallium 7440-28-0 D /L 0.045 J+ ND/NA 0.1 U 0.1 U ND/NA 0.056 J 0.045 J -21.78 Vanadium 7440-62-2 ID /L 1 10.61 J ND/NA 3.2 13.2 0 1 U 11 U ND/NA Zinc 7440-66-6 ID /L 1140 1130 1 -7.41 11 13.1 J 1 -112.06 12 15.6 J -72.73 Notes: = RPD greater than 20% pg/L = micrograms per liter pm = micron RPD (%) = relative percent difference ND/NA = not detected/not applicable U = not detected J- = estimated concentration, biased low J = laboratory estimated concentration J+ = estimated concentration, biased high Page 9 of 11 Table 2-2 Comparison of 0.45 Micron and 0.1 Micron Filter Sample Results - Groundwater Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Sample Location Sample Location Sample Location MW-ID MW-1S MW-9BR Constituent CAS RN Fraction Unit 0.45 µm Result 0.1 µm Result RPD (%) 0.45 µm Result 0.1 µm Result RPD (%) 0.45 µm Result 0.1 µm Result RPD (%) Aluminum 7429-90-5 D /L 100 U 100 U ND/NA 100 U 100 U ND/NA 100 U 100 U ND/NA Antimony 7440-36-0 D /L 0.5 U 0.5 U ND/NA 0.5 U 0.5 U ND/NA 2.5 2.5 0 Arsenic 7440-38-2 D /L 0.5 U 0.5 U ND/NA 0.48 J 0.4 J -18.18 0.36 J 0.343 -5.71 Barium 7440-39-3 D /L 31 32 3.17 25 23 -8.33 39 39 0 Beryllium 7440-41-7 D /L 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA Boron 7440-42-8 D /L 1710 720 1.4410 380 -7.59 50 U 50 U ND/NA Cadmium 7440-43-9 D /L 0.087 0.081 -7.14 0.08 U 0.08 U ND/NA 0.08 U 0.08 U ND/NA Chromium 7440-47-3 D /L 0.67 0.72 7.19 0.5 U 0.25 J ND/NA 3.2 2.4 -28.57 Cobalt 7440-48-4 D /L 0.26 J 0.241 -8 53.8 49.1 -9.14 0.5 U 0.5 U ND/NA Copper 7440-50-8 D /L 0.73 J 0.911 21.95 1 U 1 U ND/NA 0.42 J 0.37 J -12.66 Iron 7439-89-6 D /L 150 U 63 ND/NA 30500 29400 -3.67 50 U 50 U ND/NA Lead 7439-92-1 D /L 0.1 U 0.1 U ND/NA 0.1 U 0.1 U ND/NA 0.19 0.1 U ND/NA Manganese 7439-96-5 D /L 460 460 0 2500 2300 -8.33 5 U 5 U ND/NA Mercury 7439-97-6 D /L 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA 0.2 U 0.2 U ND/NA Molybdenum 7439-98-7 D /L 0.17 J 0.16 J -6.06 0.16 J 0.14 J -13.33 2.9 2.9 0 Nickel 7440-02-0 D /L 4.5 4.5 0 1.7 2.7 45.45 0.51 0.17 J -100 Selenium 7782-49-2 D /L 0.23 J 0.231 0 0.5 U 0.5 U ND/NA 0.5 U 0.5 U ND/NA Strontium 7440-24-6 D /L 320 320 0 36 32 -11.76 240 240 0 Thallium 7440-28-0 D /L 0.055 J 0.05 J -9.52 0.1 U 0.1 U ND/NA 0.1 U 0.1 U ND/NA Vanadium 7440-62-2 ID /L 11.5 11.5 0 1 U it U ND/NA 3.9 13.8 -2.6 Zinc 7440-66-6 ID /L 19.9 J 110 1 1.01 10 U 14.3 J ND/NA 3.4 J+ 13.5 J+ 2.9 Notes: = RPD greater than 20% pg/L = micrograms per liter pm = micron RPD (%) = relative percent difference ND/NA = not detected/not applicable U = not detected J- = estimated concentration, biased low J = laboratory estimated concentration J+ = estimated concentration, biased high Page 10 of 11 Table 2-2 Comparison of 0.45 Micron and 0.1 Micron Filter Sample Results - Groundwater Sample Location MW-9D Constituent CAS RN Fraction Unit 0.45 µm Result 0.1 µm Result RPD (%) Aluminum 7429-90-5 D /L 600 600 0 Antimony 7440-36-0 D /L 1.7 1.4 -19.35 Arsenic 7440-38-2 D /L 0.44 J 0.48 J 8.7 Barium 7440-39-3 D /L 16 17 6.06 Beryllium 7440-41-7 D /L 0.2 U 0.2 U ND/NA Boron 7440-42-8 D /L 150 U 50 U ND/NA Cadmium 7440-43-9 D /L 0.08 U 0.08 U ND/NA Chromium 7440-47-3 D /L 16.5 15.6 -5.61 Cobalt 7440-48-4 D /L 0.5 U 0.5 U ND/NA Copper 7440-50-8 D /L 1.9 1.1 -53.33 Iron 7439-89-6 D /L 150 U 50 U ND/NA Lead 7439-92-1 D /L 0.2 0.06 J -107.69 Manganese 7439-96-5 D /L 5 U 5 U ND/NA Mercury 7439-97-6 D /L 0.2 U 0.2 U ND/NA Molybdenum 7439-98-7 D /L 6.4 6.3 -1.57 Nickel 7440-02-0 D /L 0.5 U 0.5 U ND/NA Selenium 7782-49-2 D /L 0.4 J 0.35 J -13.33 Strontium 7440-24-6 D /L 220 230 4.44 Thallium 7440-28-0 D /L 0.1 U 0.1 U ND/NA Vanadium 7440-62-2 D /L 16.2 16.3 0.62 Zinc 7440-66-6 D /L 7.8 J+ 3 J+ -88.89 Notes: = RPD greater than 20% pg/L = micrograms per liter pm = micron RPD (%) = relative percent difference ND/NA = not detected/not applicable U = not detected J- = estimated concentration, biased low J = laboratory estimated concentration J+ = estimated concentration, biased high Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Page 11 of 11 Table 2-3 Ash Porewater Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: AB-3S AB-3S AB-4S AB-4S AB-5S AB-5S AB-5S Round 1 Round 2 Round 1 Round 2 Round 1 Round 1 Round 2 7/2/2015 9/17/2015 6/28/2015 9/17/2015 6/20/2015 6/25/2015 9/15/2015 N N N N N N N AB-3S RV-AB-3S-NS-3Q15 AB-4S RV-AB-4S-NS-3Q15 AB-5S AB-5S RV-AB-5S-NS-3Q15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D /L 140 100 U 710 140 140 140 Aluminum 7429-90-5 T p /L 2600 4900 790 39500 1600 4600 Antimony 7440-36-0 D - u /L 0.28 J 0.5 U 0.5 U 2 23.8 32.3 Antimony 7440-36-0 T 1 IMAC I pq/L 0.58 0.41 J 2.2 1.8 21.6 32.9 Arsenic 7440-38-2 D /L 258 357 0.5 U 278 644 818 Arsenic 7440-38-2 T 10 02L p /L 283 362 J+ 428 3290 651 943 Barium 7440-39-3 D - p /L 190 180 94 93 250 210 Barium 7440-39-3 T 700 02L /L 220 210 98 690 310 320 Beryllium 7440-41-7 D /L 0.086 J 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Beryllium 7440-41-7 T 4 IMAC p /L 0.16 J 0.67 J+ 0.2 U 2 0.34 1.7 Boron 7440-42-8 D - p /L 420 370 520 520 1400 1600 Boron 7440-42-8 T 700 02L /L 410 330 500 460 1400 1500 Cadmium 7440-43-9 D /L 0.08 U 0.08 U 0.08 U 0.08 U 0.079 J 0.062 J Cadmium 7440-43-9 T 2 02L p /L 0.025 J 0.063 J+ 0.041 J 0.69 0.1 0.22 Calcium 7440-70-2 T - p /L 26000 21800 35300 42300 79700 70400 Chromium 7440-47-3 D /L 2.4 J 0.26 J 0.18 J+ 0.5 J 0.21 J+ 0.23 J Chromium 7440-47-3 T 10 02L /L 4.3 17.6 J+ 0.56 J+ 24.3 1.8 J+ 7.1 Cobalt 7440-48-4 D - p /L 1.3 0.48 J 0.5 U 1.5 0.2 J 0.5 U Cobalt 7440-48-4 T 1 IMAC p /L 1.9 5.7 J+ 5.7 142 1 5.1 Copper 7440-50-8 D /L 3.5 J+ 5.6 0.75 J+ 1 U 3.2 4.4 Copper 7440-50-8 T 1000 02L /L 7 24.7 J+ 0.23 J+ 35A 5.5 28.2 Iron 7439-89-6 D - p /L 2400 2800 50 U 50 U 50 U 50 U Iron 7439-89-6 T 300 02L p /L 6500 11400 32 J 13700 J+ 660 2000 Lead 7439-92-1 D /L 0.88 0.52 0.1 U 0.1 U 0.24 0.43 Lead 7439-92-1 T 15 02L /L 1.7 5.9 J+ 0.1 U 8 1.7 11.5 Magnesium 7439-95-4 T - p /L 6380 5480 6230 8710 16900 17500 Manganese 7439-96-5 D - p /L 860 600 1200 520 39 26 Manganese 7439-96-5 T 50 02L /L 910 620 1200 2300 48 43 Mercury 7439-97-6 D - p /L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 UJ 0.2 U Mercury 7439-97-6 T 1 02L p /L 0.2 U 0.2 U 0.2 U 0.074 J 0.077 J+ 0.2 U Methane 74-82-8 N - p /L 268 16.3 J+ 13 J+ 10.5 J+ 10 UJ 44.4 Molybdenum 7439-98-7 D /L 32.5 27.3 0.5 U 52.9 269 276 Molybdenum 7439-98-7 T /L 28.8 22.8 J+ 46.5 33.4 263 241 Nickel 7440-02-0 D - p /L 1.4 J+ 1 0.24 J+ 3.7 0.97 0.95 Nickel 7440-02-0 T 100 02L u /L 2.2 9.5 J+ 0.74 J+ 26.4 2.4 10.3 Potassium 7440-09-7 T /L 5140 5360 20500 21000 14100 10900 Selenium 7782-49-2 D /L 0.5 U 0.5 U 0.5 U 0.37 J 1.2 0.72 Selenium 7782-49-2 T 20 02L p /L 0.5 U 0.29 J 0.84 0.63 1.3 1.1 Sodium 7440-23-5 T - p /L 6870 4660 J 19500 15400 11400 8520 Strontium 7440-24-6 D /L 890 820 680 970 2300 1900 J- Strontium 7440-24-6 T /L 940 800 700 1400 2700 2200 Thallium 7440-28-0 D - p /L 0.056 J 0.058 J 0.1 U 0.11 0.36 0.19 Thallium 7440-28-0 T 0.2 IMAC p /L 0.075 J 0.23 J+ 0.19 0.72 0.48 0.65 Vanadium 7440-62-2 D /L 6 0.55 J 1 U 92.1 200 285 Vanadium 7440-62-2 T 0.3 IMAC /L 11.3 35.5 J+ 166 609 231 257 Zinc 7440-66-6 D - p /L 10 U 31 10 U 17 10 U 21 Zinc 7440-66-6 T 1000 02L I p /L 8.9 J+ 30 J+ 10 U 86 4.8 J+ 74 Total Dissolved Solids TDS N 500000 02L /L 174000 143000 234000 202000 381000 339000 Total Organic Carbon TOC N /L 780 J 1000 U 740 J 1000 U 710 J 720 J Total Suspended Solids TSS N p /L 35000 186000 7700 151000 180000 465000 Alkalinity, CO3 ALK-CO3 N p /L 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U Alkalinity, HCO3 ALK-HCO3 N /L 52600 50200 69600 80200 201000 145000 Alkalinity, lab ALK-LAB N /L 52600 50200 69600 80200 201000 145000 Chloride 16887-00-6 N 250000 02L p /L 7000 6300 6000 4400 11500 10800 Nitrogen, NO2 plus NO3 NO2-NO3 N - p /L 181 20 U 20 U 24 20 U 43 Sulfate 14808-79-8 N 250000 02L /L 48000 39700 88900 J+ 82700 99600 99700 Sulfide 18496-25-8 N /L 100 U - 100 U 100 U 100 U - 100 U As III 7784-46-5 T p /L 270 - - - 44.9 - As V 10103-60-3 T - p /L 19.9 611 J+ Chromium VI 18540-29-9 T 0.07 DHHS /L 1 0.05 U 0.026 Fe II 1345-25-1 T - p /L 2160 20 U Fe III 1309-37-1 T p /L 311 20 U Mn II 1344-43-0 T p /L 981 47.7 Page 1 of 4 Table 2-3 Ash Porewater Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: AB-3S AB-3S AB-4S AB-4S AB-5S AB-5S AB-5S Round 1 Round 2 Round 1 Round 2 Round 1 Round 1 Round 2 7/2/2015 9/17/2015 6/28/2015 9/17/2015 6/20/2015 6/25/2015 9/15/2015 N N N N N N N AB-3S RV-AB-3S-NS-3Q15 AB-4S RV-AB-4S-NS-3Q15 AB-5S AB-5S RV-AB-5S-NS-3Q15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Mn IV 1313-13-9 T /L 1 U 1 U Se IV 10102-18-8 T p /L 0.5 U 0.84 Se VI 13410-01-0 T p /L 0.5 U - - - - 0.254 - Dissolved Oxygen DO N m /L 0.2 0.2 0.29 0.9 0.41 - 0.3 Temperature TEMP N Deg C 24.4 28.4 21 27.2 23.3 28.9 pH PH N 6.5 8.5 02L SU 6.8 6.8 9.8 6.7 8.09 8.3 Turbidity, field TURB N - - NTU 105.6 105.1 6.52 27.53 3.34 26.3 Specific Conductivity field SC NPS/cm 253.8 219.9 534 346.8 597 532 Oxidation Reduction Potential ORP N mV -62.4 -106.5 -112.6 23.5 26.2 3.1 GW Depth TOC GW DEPTH-TOCI N ft 20.76 Notes: pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 2 of 4 Table 2-3 Ash Porewater Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: AB-5SL AB-5SL AB-5SL AB-7S AB-7S AB-7S C-is C-is Round 1 Round 1 Round 2 Round 1 Round 1 Round 2 Round 1 Round 2 6/8/2015 6/25/2015 9/16/2015 6/22/2015 6/24/2015 9/16/2015 6/17/2015 9/15/2015 N N N N N N N N AB-5SL AB-5SL RV-AB-5SL-NS-3Q15 AB-7S AB-7S RV-AB-7S-NS-3Q15 C-is RV-C-IS-NS-3Q15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D /L 4830 4300 100 U 100 U 770 1300 Aluminum 7429-90-5 T p /L 6370 5000 190 100 U 1200 1200 Antimony 7440-36-0 D - u /L 2.9 2.9 0.5 U 0.5 U 0.5 U 0.5 U Antimony 7440-36-0 T 1 IMAC I pq/L 3.2 2.4 0.5 U 0.28 J 0.5 U 0.5 U Arsenic 7440-38-2 D /L 69.7 88.7 23.4 8.6 25.5 10.3 Arsenic 7440-38-2 T 10 02L p /L 75.1 79 24.3 173 25.8 12 Barium 7440-39-3 D - p /L 120 91 68 54 48 28 Barium 7440-39-3 T 700 02L /L 140 100 72 57 51 28 J+ Beryllium 7440-41-7 D /L 0.2 U 0.2 U 0.2 U 0.2 U 0.42 4.7 Beryllium 7440-41-7 T 4 IMAC p /L 0.086 J 0.098 J 0.2 U 0.11 J 0.4 6.6 Boron 7440-42-8 D - p /L 2100 2200 320 360 310 220 Boron 7440-42-8 T 700 02L /L 2400 2300 320 370 300 200 Cadmium 7440-43-9 D /L 0.08 U 0.18 0.08 U 0.08 U 0.08 U 0.08 U Cadmium 7440-43-9 T 2 02L p /L 0.071 J 0.08 UJ 0.034 J 0.03 J 0.08 U 0.08 U Calcium 7440-70-2 T - pg/L 89900 70900 J- 13300 15300 54600 202000 Chromium 7440-47-3 D /L 0.25 J+ 0.2 J+ 0.37 J+ 0.27 J 1.6 1.9 Chromium 7440-47-3 T 10 02L /L 0.99 J+ 1.5 0.84 J+ 0.96 J+ 4 2 J+ Cobalt 7440-48-4 D - p /L 0.5 U 0.5 U 13.7 13.2 115 299 Cobalt 7440-48-4 T 1 IMAC p /L 0.25 J 0.36 J 13.4 10.4 102 387 Copper 7440-50-8 D /L 1 U 1.2 J+ 2.2 J+ 0.44 J 1 U 0.24 J Copper 7440-50-8 T 1000 02L /L 1.5 J+ 1.7 0.92 J 2 2.2 0.59 J+ Iron 7439-89-6 D - p /L 50 U 50 U 11000 10000 176000 107000 Iron 7439-89-6 T 300 02L p /L 240 290 11200 10000 175000 102000 Lead 7439-92-1 D /L 0.1 U 0.31 0.16 0.085 J 0.1 U 0.093 J Lead 7439-92-1 T 15 02L /L 0.4 0.57 0.29 0.95 0.25 0.093 J+ Magnesium 7439-95-4 T - p /L 677 1010 4250 5280 23500 76700 Manganese 7439-96-5 D - p /L 4.3 J 5 U 1300 1200 3400 10600 Manganese 7439-96-5 T 50 02L /L 6.7 4.8 J 1300 1200 3200 9400 Mercury 7439-97-6 D - p /L 0.2 U 0.2 U 02 U 0.2 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L p /L 1 0.2 U 0.2 U 0.076 J+ 0.2 U 0.14 J+ 0.2 U Methane 74-82-8 N - p /L 3000 9300 84.7 J 97.1 262 J 193 Molybdenum 7439-98-7 D /L 594 584 0.74 0.53 0.5 U 0.5 U Molybdenum 7439-98-7 T /L 586 536 0.75 5.4 0.5 U 0.5 U Nickel 7440-02-0 D - p /L 0.37 J 0.94 J+ 1.2 1.1 33.5 95.2 Nickel 7440-02-0 T 100 02L u /L 1.1 1.6 1.4 J+ 1.4 30.8 116 Potassium 7440-09-7 T /L 20800 18000 4540 J 5110 23600 14400 Selenium 7782-49-2 D /L 3.1 1.7 0.5 U 0.5 U 0.47 J 0.82 Selenium 7782-49-2 T 20 02L p /L 4 2.1 0.5 U 0.23 J 0.66 0.94 Sodium 7440-23-5 T - p /L 9560 8110 9040 6920 21900 24200 Strontium 7440-24-6 D /L 2400 2200 330 310 1400 1600 Strontium 7440-24-6 T /L 2700 2100 340 320 1400 1600 Thallium 7440-28-0 D p /L 0.1 U 0.1 U 0.23 0.23 0.03 J 0.046 J Thallium 7440-28-0 T 0.2 IMAC p /L 1 0.042 J 0.035 J+ - 0.25 0.062 J 0.1 U Vanadium 7440-62-2 D /L 130 95.9 1 U 1 U 2.7 3.9 Vanadium 7440-62-2 T 0.3 IMAC /L 151 84.4 1.1 8.7 4 6.5 Zinc 7440-66-6 D - p /L 10 U 10 U 3 J 5.1 J 82 63 Zinc 7440-66-6 T 1000 02L p /L 10 U 2.8 J 5.3 J 5.6 J+ 91 63 Total Dissolved Solids TDS N 500000 02L /L 420000 J- 342000 140000 106000 1110000 1770000 Total Organic Carbon TOC N /L 660 J 1000 U 680 J 510 J 3900 4500 Total Suspended Solids TSS N p /L 140000 J- 290000 2500 U 80800 12600 2600 Alkalinity, CO3 ALK-CO3 N p /L 18000 35300 5000 U 5000 U 5000 U 5000 U Alkalinity, HCO3 ALK-HCO3 N /L 40000 16400 24100 19000 J+ 11000 39100 Alkalinity, lab ALK-LAB N /L 60000 51700 24100 19000 J+ 11000 39100 Chloride 16887-00-6 N 250000 02L p /L 7900 7500 2100 2000 9400 8300 Nitrogen, NO2 plus NO3 NO2-NO3 N - p /L 20 U 20 U 19 J+ 110 J+ 20 U 20 U Sulfate 14808-79-8 N 250000 02L /L 208000 182000 64800 62600 559000 934000 Sulfide 18496-25-8 N /L 100 U - 100 U 100 U - 100 U 500 U 500 U As III 7784-46-5 T p /L - 23.7 - - 17.4 - - As V 10103-60-3 T - p /L 46.2 J+ 3.81 Chromium VI 18540-29-9 T 0.07 DHHS /L 0.05 U 0.05 U Fe II 1345-25-1 T - p /L 50.8 J- 9570 Fe(III) 1309-37-1 T p /L 20 U 1340 Mn(II) 1344-43-0 T pg/L 3.53 J+ 1600 Page 3 of 4 Table 2-3 Ash Porewater Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: AB-5SL AB-5SL AB-5SL AB-7S AB-7S AB-7S C-is C-is Round 1 Round 1 Round 2 Round 1 Round 1 Round 2 Round 1 Round 2 6/8/2015 6/25/2015 9/16/2015 6/22/2015 6/24/2015 9/16/2015 6/17/2015 9/15/2015 N N N N N N N N AB-5SL AB-5SL RV-AB-5SL-NS-3Q15 AB-7S AB-7S RV-AB-7S-NS-3Q15 C-is RV-C-IS-NS-3Q15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Mn IV 1313-13-9 T /L 0.14 J+ 22.2 Se IV 10102-18-8 T p /L 2.47 0.5 U Se VI 13410-01-0 T p /L 0.364 - - 0.5 U - - - Dissolved Oxygen DO N I m /L 0.22 0.3 0.23 - 0.1 0.35 0.6 Temperature TEMP N - - Deg C 21.87 22.6 19.69 28.8 18.43 23.2 pH PH N 6.5 8.5 02L SU 10.73 10.3 5.4 5.7 4.96 5.1 Turbidity, field TURB N - - NTU 1.86 9.4 3.57 32.7 3.14 9 Specific Conductivity field SC NPS/cm 652 508.6 222 219.3 801 1743 Oxidation Reduction Potential ORP N mV -119.7 -107 53.4 24 -25.2 -66.5 GW Depth TOC GW_DEPTH-TOC N ft - - - 17.15 - 11.48 Notes: pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 4 of 4 Table 2-4 Ash Basin Water Sample Analytical Results - Round 1 and Round 3 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: SW-1 SW-1 SW-1 SW-2 SW-2 SW-2 Round 1 Round 1 Round 3 Round 1 Round 1 Round 3 6/8/2015 6/25/2015 11/17/2015 6/8/2015 6/25/2015 11/17/2015 N N N N N N SW-1 SW-1 RV-SW-1-NS-4Q15-1 SW-2 SW-2 RV-SW-2-NS-4Q15-1 Constituent CAS RN Fraction Criteria Min (range only) 02B Class B Water Supply Surface Water Criteria Criteria Source Unit Aluminum 7429-90-5 D pg/L 62.2 100 U 51.7 100 U Aluminum 7429-90-5 T 87 pg/L 43900 - 120 93.1 220 Antimony 7440-36-0 D pg/L 3.5 - 2.4 2.4 2.4 Antimony 7440-36-0 T 5.6 pg/L 7.3 - 2.6 2.6 2.5 Arsenic 7440-38-2 D 150 pg/L 23.7 - 9.4 33 9.7 Arsenic 7440-38-2 T 10 pg/L 229 - 12.5 37.2 13.6 Barium 7440-39-3 D pg/L 600 - 170 120 170 Barium 7440-39-3 T 1000 pg/L 820 - 170 130 170 Beryllium 7440-41-7 D 6.5 pg/L 0.075 J - 0.2 U 0.067 U 0.2 U Beryllium 7440-41-7 T pg/L 17.6 - 0.2 U 0.067 U 0.2 U Boron 7440-42-8 D pg/L 420 - 460 390 470 Boron 7440-42-8 T pg/L 430 - 430 410 420 Cadmium 7440-43-9 D 0.15 pg/L 0.024 U - 0.13 0.043 J 0.13 Cadmium 7440-43-9 T pg/L 2 - 0.15 0.055 J 0.2 Calcium 7440-70-2 T pg/L 18900 - 19200 16300 19100 Chromium 7440-47-3 D 11 pg/L 0.56 - 0.19 J 0.18 J 0.5 U Chromium 7440-47-3 T 11 pg/L 47.6 - 0.34 J 0.5 0.41 J Cobalt 7440-48-4 D 3 pg/L 0.91 - 2.4 0.13 U 2.5 Cobalt 7440-48-4 T 3 pg/L 56.5 - 3.4 0.16 J 3.6 Copper 7440-50-8 D 2.7 pg/L 0.44 J+ - 1.7 2.4 J+ 2.5 Copper 7440-50-8 T pg/L 315 - 2 1.4 J+ 2.5 Iron 7439-89-6 D pg/L 13.7 U - 50 U 13.7 U 50 U Iron 7439-89-6 T 1000 pg/L 19100 - 57 29.9 J 170 Lead 7439-92-1 D 0.54 pg/L 0.046 U - 0.095 J 0.19 J+ 0.14 Lead 7439-92-1 T 2.5 pg/L 107 - 0.22 0.048 J 0.44 Magnesium 7439-95-4 T pg/L 3720 - 3810 3350 3820 Manganese 7439-96-5 D pg/L 130 - 14 2.5 U 14 Manganese 7439-96-5 T 50 pg/L 140 - 24 3.3 J 25 Mercury 7439-97-6 D pg/L 0.001 U - - 0.001 U - Mercury 7439-97-6 T 0.012 pg/L 0.0072 - 0.000708 J+ 0.001 U 0.000439 J+ Methane 74-82-8 N pg/L 98 - 3.7 J+ 10 U 1.6 J+ Molybdenum 7439-98-7 D pg/L 58.3 - 51.6 53.5 52.6 Molybdenum 7439-98-7 T 160 pg/L 55.1 - 58.2 60.3 57.5 Nickel 7440-02-0 D 16 pg/L 4.2 - 7.6 4.4 7.6 Nickel 7440-02-0 T 25 pg/L 103 - 9.1 5 9.1 Potassium 7440-09-7 T pg/L 5440 - 5550 4940 J 5540 Selenium 7782-49-2 D pg/L 1.1 - 0.7 0.96 0.78 Selenium 7782-49-2 T 5 pg/L 5 - 0.8 1.1 0.72 Sodium 7440-23-5 T pg/L 4590 J - 4780 J 4780 J 4780 J Strontium 7440-24-6 D pg/L 470 - 500 410 510 Strontium 7440-24-6 T 14000 pg/L 790 - 520 440 500 Thallium 7440-28-0 D pg/L 0.3 - 0.62 0.81 0.62 Thallium 7440-28-0 T 0.24 pg/L 5.4 - 0.69 0.94 0.67 Vanadium 7440-62-2 D pg/L 17.2 - 4.6 6.7 4.2 Vanadium 7440-62-2 T pg/L 275 - 5.4 7.8 6 Zinc 7440-66-6 D 36 pg/L 7.6 J - 11 2.5 U 16 Zinc 7440-66-6 T 120 pg/L 150 - 12 42 J+ 12 Total Dissolved Solids TDS N 250000 pg/L 99000 J- - 62000 99000 J- 71000 Total Organic Carbon TOC N pg/L 1200 - 1400 1200 2700 Total Suspended Solids TSS N pg/L 57000000 J- - 3300 1 3300 J- 3500 Alkalinity, CO3 ALK-CO3 N pg/L 10000 U 5000 U 10000 U 5000 U Alkalinity, HCO3 ALK-HCO3 N pg/L 12000 10300 12000 9700 Alkalinity, lab ALK-LAB N 100000 pg/L 12000 - 10300 12000 9700 Page 1 of 2 Table 2-4 Ash Basin Water Sample Analytical Results — Round 1 and Round 3 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: SW-1 SW-1 SW-1 SW-2 SW-2 SW-2 Round 1 Round 1 Round 3 Round 1 Round 1 Round 3 6/8/2015 6/25/2015 11/17/2015 6/8/2015 6/25/2015 11/17/2015 N N N N N N SW-1 SW-1 RV-SW-1-NS-4Q15-1 SW-2 SW-2 RV-SW-2-NS-4Q15-1 Constituent CAS RN Fraction Criteria Min (range only) 02B Class B Water Supply Surface Water Criteria Criteria Source Unit Chloride 16887-00-6 N 230000 pg/L 5400 5200 5400 2500 Nitrogen, NO2 plus NO3 NO2-NO3 N pg/L IOU 20 U 10 U 20 U Sulfate 14808-79-8 N 250000 pg/L 54100 59100 55200 1300 Sulfide 18496-25-8 N pg/L 100 U 100 U 100 U 100 U Arsenic 7440-38-2 T 10 pg/L - - - - - Chromium 7440-47-3 T 11 pg/L Iron 7439-89-6 T 1000 pg/L - Manganese 7439-96-5 D pg/L Manganese 7439-96-5 T 50 pg/L - - As(III) 7784-46-5 T pg/L 0.945 - 0.692 As(V) 10103-60-3 T pg/L 34.5 J+ 34.5 J+ Chromium (VI) 18540-29-9 D DHHS pg/L - - - - - Chromium (VI) 18540-29-9 T 11 pg/L 0.099 0.015 J+ - 0.106 0.021 J Fe(II) 1345-25-1 T pg/L 20 U - - 20 U - Fe(III) 1309-37-1 T pg/L 20 U - 20 U Mn(II) 1344-43-0 T pg/L 2.17 J+ - 5 U Mn(IV) 1313-13-9 T pg/L 4.01 - 2.27 Se(IV) 10102-18-8 T pg/L 0.852 - 0.884 Se(VI) 13410-01-0 T pg/L 0.497 - 0.284 Dissolved Oxygen DO N 5 mg/L - - - - - Dissolved Oxygen DO N 5.0 mg/L 7.4 - 6.9 Dissolved Oxygen DO N 5.00 mg/L - - - - Temperature TEMP N Deg C 21 - 17.1 pH PH N 6.0 9.0 SU - 7.5 - 7.4 Turbidity, field TURB N 25 NTU 6 - 5.9 Specific Conductivity (field) SC N PS/cm 191.2 348 Oxidation Reduction Potential ORP N mV 146.9 143.1 Notes: pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 2 of 2 Table 2-5 Groundwater Results within Waste Boundary Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: AB-1 D AB-1 D AB-1 S AB-1 S AB-2D AB-21D AB-2S AB-2S Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 7/9/2015 9/16/2015 7/9/2015 9/16/2015 7/8/2015 9/16/2015 7/8/2015 9/16/2015 N N N N N N N N AB-1D RV-AB-1 D-NS-3Q1 5 AB-1S RV-AB-1S-NS-3Q15 AB-21D RV-AB-2D-NS-3Q15 AB-2S RV-AB-2S-NS-3Q15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D pg/L 610 220 100 U 100 U 710 100 U 100 U 100 U Aluminum 7429-90-5 T pg/L 1100 320 220 3000 1000 1100 680 1000 Antimony 7440-36-0 D pg/L 1.5 4 2.8 0.5 U 0.85 0.65 3.4 0.39 J Antimony 7440-36-0 T 1 IMAC p /L 6.3 3.3 3.2 0.5 U 1 0.54 3.1 0.33 J Arsenic 7440-38-2 D pg/L 0.51 0.12 J 0.14 J 0.5 U 0.67 0.44 J 0.5 U 0.21 J Arsenic 7440-38-2 T 10 02L p /L 0.84 0.33 J 0.17 J 0.12 J 0.72 0.79 0.2 J 0.46 J Barium 7440-39-3 D p /L 27 41 21 17 12 16 25 35 Barium 7440-39-3 T 700 02L p /L 30 38 21 23 13 24 28 42 Beryllium 7440-41-7 D pg/L 0.2 U 0.2 U 0.2 U 0.2 U 0.091 J 0.2 U 0.14 J 0.2 U Beryllium 7440-41-7 T 4 IMAC p /L 0.068 J 0.2 U 0.12 J 0.2 U 0.2 U 0.2 U 0.15 J 0.078 J Boron 7440-42-8 D pg/L 67 63 50 U 50 U 200 340 50 U 50 U Boron 7440-42-8 T 700 02L p /L 65 58 50 U 50 U 160 350 50 U 50 U Cadmium 7440-43-9 D pg/L 0.062 J 0.08 U 0.028 J 0.08 U 0.034 J 0.08 U 0.041 J 0.03 J Cadmium 7440-43-9 T 2 02L p /L 0.031 J 0.08 U 0.08 U 0.08 U 0.045 J 0.08 UJ 0.065 J 0.03 J+ Calcium 7440-70-2 T pg/L 123000 104000 1170 790 64000 53900 J- 1130 2310 J- Chromium 7440-47-3 D p /L 21.2 19.7 0.48 J 0.43 J 12.1 3.8 0.3 J+ 0.56 J+ Chromium 7440-47-3 T 10 02L pg/L 49.2 17 1.8 J+ 1.3 J+ 13 8.6 2.5 J+ 4.1 Cobalt 7440-48-4 D p /L 0.5 U 0.5 U 16.2 14.5 0.5 U 0.5 U 15.9 32.1 Cobalt 7440-48-4 T 1 IMAC pg/L 2.9 0.5 U 15.9 13.4 0.15 J 0.44 J 17.1 26.2 Copper 7440-50-8 D p /L 0.44 J 0.82 J 0.8 J 0.49 J 5.5 J 1.5 J+ 6.5 J+ 6.4 Copper 7440-50-8 T 1000 02L p /L 6.2 0.51 J 6.4 1.2 6.9 5.8 7.6 2.8 Iron 7439-89-6 D p /L 50 U 50 U 50 U 50 U 50 U 50 U 50 U 50 U Iron 7439-89-6 T 300 02L p /L 370 50 U 510 8100 130 830 1700 2200 Lead 7439-92-1 D p /L 0.13 0.15 0.077 J 0.1 U 0.13 J 0.15 0.12 J+ 0.55 Lead 7439-92-1 T 15 02L pg/L 0.85 0.1 U 0.18 0.49 0.13 0.22 0.29 0.31 Magnesium 7439-95-4 T p /L 524 241 974 894 270 6670 610 850 Manganese 7439-96-5 D pg/L 5 U 5 U 260 200 5 U 5 U 310 830 Manganese 7439-96-5 T 50 02L p /L 10 5 U 250 250 5.6 25 330 900 Mercury 7439-97-6 D pg/L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L p /L 0.09 J 0.2 U 0.11 J+ 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Methane 74-82-8 N pg/L 2 J+ 2.5 J+ 68.3 28.3 1.2 J+ 11.7 J+ 65.3 11.1 J+ Molybdenum 7439-98-7 D p /L 4.2 6.7 0.12 J 0.5 U 14.1 2.4 0.5 U 0.5 U Molybdenum 7439-98-7 T pg/L 4.6 5.5 0.17 J 0.5 U 8.9 1.9 J+ 0.24 J 0.12 J+ Nickel 7440-02-0 D p /L 0.5 U 0.5 U 2.9 3.4 0.5 UJ 0.39 J+ 3.6 4.6 Nickel 7440-02-0 T 100 02L pg/L 16.6 0.67 3.3 3.6 0.28 J 4.1 3 5.3 Potassium 7440-09-7 T p /L 6920 34700 5000 U 5000 U 4040 J 3060 J 5000 U 5000 U Selenium 7782-49-2 D p /L 0.9 0.62 0.78 0.5 U 0.53 0.2 J 0.5 U 1.5 Selenium 7782-49-2 T 20 02L p /L 0.46 J 0.55 0.5 U 0.26 J 0.57 0.21 J 0.5 U 1.5 Sodium 7440-23-5 T pg/L 7830 13800 2960J 2520J 11800 11300 5000 U 57600 Strontium 7440-24-6 D p /L 330 450 11 12 170 200 12 24 Strontium 7440-24-6 T pg/L 360 410 12 7.6 180 230 12 25 Thallium 7440-28-0 D p /L 0.097 J 0.018 J 0.018 J 0.019 J 0.055 J 0.1 U 0.052 J 0.039 J Thallium 7440-28-0 T 0.2 IMAC pg/L 0.064 J 0.1 U 0.1 U 0.1 U 0.06 J 0.1 U 0.072 J 0.036 J+ Vanadium 7440-62-2 D p /L 11.5 8.7 1 U 1 U 31.1 8.9 1 U 1 U Vanadium 7440-62-2 T 0.3 IMAC pg/L 20 7.7 1.8 1.5 32.4 9.4 3.8 4.1 Zinc 7440-66-6 D p /L 10 U 9.5 J 26 29 34 22 J+ 33 90 Zinc 7440-66-6 T 1000 02L pg/L 12 10 U 33 23 18 16 J+ 31 110 Total Dissolved Solids TDS N 500000 02L p /L 351000 367000 40000 38000 241000 182000 30000 197000 Total Organic Carbon TOC N pg/L 1400 720 J 900 J 1000 U 2700 1000 U 640 J+ 970 J Total Suspended Solids TSS N p /L 2800 U 9300 90000 154000 7800 253000 32000 157000 Alkalinity, CO3 ALK-CO3 N pg/L 211000 29200 5000 U 5000 U 36400 11500 5000 U 5000 U Alkalinity, HCO3 ALK-HCO3 N p /L 72000 5000 U 1900 J 3500 J+ 107000 90900 1600 J 6600 Alkalinity, lab ALK-LAB N pg/L 282000 296000 1900 J 3500 J+ 143000 102000 1600 J 6600 Chloride 16887-00-6 N 250000 02L p /L 4900 5500 5300 4700 6400 5900 3300 17200 Fluoride 16984-48-8 N pg/L - - - - - - - - Nitro en, NO2 plus NO3 NO2-NO3 N p /L 230 230 720 480 83 200 940 490 Sulfate 14808-79-8 N 250000 02L pg/L 22800 33800 690J 810J 22700 19000 1000 UJ 104000 Sulfide 18496-25-8 N p /L 100 U 100 U 100 U 100 U 100 U 100 U 100 U 100 U Arsenic 7440-38-2 T 10 02L pg/L - - - - 0.682 - 0.568 - Chromium 7440-47-3 T 10 02L p /L 13.4 2.16 J+ Iron 7439-89-6 T 300 02L pg/L 143 273 J+ Manganese 7439-96-5 D p /L 1.85J 249 Manganese 7439-96-5 T 50 02L pg/L 4.87 1 - 346 Page 1 of 16 Table 2-5 Groundwater Results within Waste Boundary Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: ABAD AB-1D ABAS ABAS AB-2D AB-2D AB-2S AB-2S Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 7/9/2015 9/16/2015 7/9/2015 9/16/2015 7/8/2015 9/16/2015 7/8/2015 9/16/2015 N N N N N N N N ABAD RV-AB-1D-NS-3Q15 ABAS RV-AB-1S-NS-3Q15 AB-2D RV-AB-2D-NS-3Q15 AB-2S RV-AB-2S-NS-3Q15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit As III 7784-46-5 T /L 0.5 UJ 0.5 UJ As V 10103-60-3 T /L 0.682 0.568 Chromium VI 18540-29-9 D 0.07 DHHS /L 11 0.02 U Chromium VI 18540-29-9 T 0.07 DHHS /L Fe II 1345-25-1 T /L 30 R 30 R Fe III 1309-37-1 T /L - - Mn II 1344-43-0 T /L Mn IV 1313-13-9 T /L - Se IV 10102-18-8 T /L 2 U 2 U Se VI 13410-01-0 T /L 2 U 2 U Dissolved Oxygen DO N /L1.1 P 1.12 1.63 0.2 3.69 1 1.23 0.5 Tem erature TEMP N e C 23.3 17.8 27.2 26.3 27.4 23 25.6 27 H PH N 6.5 8.5 02L SU 11.6 11.7 5.18 5.1 10.94 9.3 5.1 5.1 Turbidity, field TURB N NTU 16.89 5.88 41.89 51.88 6.23 10 57.88 31.5 Specific Conductivity field SC NPS/cm 1367 1438 35.7 31.8 515 265 26.8 359.5 Oxidation Reduction Potential ORP N mV -49.1 -14.1 257.6 256.9 19 -0.2 237.5 255.8 GW Depth TOC GW DEPTH-TOC N I ft - - - - - 42.14 - 41.62 Notes: pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 2 of 16 Table 2-5 Groundwater Results within Waste Boundary Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: AB-3BR AB-3BR AB-3D AB-3D AB-4D AB-4D AB-5D AB-5D Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 Round 1 7/23/2015 9/17/2015 7/7/2015 9/17/2015 7/8/2015 9/17/2015 6/20/2015 7/8/2015 N N N N N N N N AB-3BR RV-AB-3BR-NS-3Q15 AB-3D RV-AB-3D-NS-3Q15 AB-4D RV-AB-4D-NS-3Q15 AB-5D AB-51D Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D pg/L 518 98 J 160 630 190 61 J 310 Aluminum 7429-90-5 T p /L 7120 380 1800 670 400 360 580 Antimony 7440-36-0 D pg/L 1 U 2.5 0.5 U 0.76 1.4 3.9 0.58 Antimony7440-36-0 T 1 IMAC p /L 1 U 3.1 0.22 J 0.59 1.2 4.3 1.2 Arsenic 7440-38-2 D pg/L 1 U 1.2 0.5 U 0.24 J 0.6 0.72 0.45 J Arsenic 7440-38-2 T 10 02L p /L 1.23 1.3 J+ 0.49 J 0.22 J+ 0.65 0.82 0.25 J Barium 7440-39-3 D p /L 8 7.1 190 94 17 7.2 23 Barium 7440-39-3 T 700 02L p /L 18 9.1 190 89 18 8.9 27 Beryllium 7440-41-7 D pg/L 1 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Beryllium 7440-41-7 T 4 IMAC p /L 1 U 0.2 UJ 0.2 U 0.2 UJ 0.2 U 0.2 U 0.2 U Boron 7440-42-8 D pg/L 50 U 50 U 50 U 50 U 26 J 50 U 170 J+ Boron 7440-42-8 T 700 02L p /L 50 U 50 U 50 U 50 U 50 U 50 U 150 Cadmium 7440-43-9 D pg/L 1 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U Cadmium 7440-43-9 T 2 02L p /L 1 U 0.08 UJ 0.08 U 0.08 UJ 0.08 U 0.08 U 0.08 U Calcium 7440-70-2 T pg/L 31300 11200 283000 158000 32900 16900 42600 Chromium 7440-47-3 D p /L 1.99 0.37 J 45.3 23.5 6.4 2.6 3.9 Chromium 7440-47-3 T 10 02L pg/L 8.27 7.1 J+ 51 26 J+ 7.4 2.9 5.3 Cobalt 7440-48-4 D p /L 1 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U Cobalt 7440-48-4 T 1 IMAC pg/L 1.64 0.23 J+ 0.18 J 0.5 UJ 0.18 J 0.21 J 0.5 U Copper 7440-50-8 D p /L 2.26 0.41 J 2.4 5.5 1.1 J+ 0.41 J 0.99 J+ Copper 7440-50-8 T 1000 02L p /L 9.15 1.6 J+ 4.7 4.4 J+ 1.2 1.6 1.7 J+ Iron 7439-89-6 D p /L 33 50 U 50 U 69 50 U 50 U 50 U Iron 7439-89-6 T 300 02L p /L 4440 210 270 50 U 130 310 J+ 56 Lead 7439-92-1 D p /L 1 U 0.11 0.16 0.39 0.1 UJ 0.19 0.088 J Lead 7439-92-1 T 15 02L pg/L 1 U 0.3 J+ 0.44 J+ 0.1 J+ 0.055 J 0.15 J+ 0.1 U Magnesium 7439-95-4 T p /L 1930 764 141 100 U 571 2590 1950 Manganese 7439-96-5 D pg/L 5 U 5 U 5 U 5 U 5 U 5 U 5 U Manganese 7439-96-5 T 50 02L p /L 87 6 6.7 5 U 4.1 J 9.7 5 U Mercury 7439-97-6 D pg/L 0.05 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L p /L 0.05 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Methane 74-82-8 N pg/L 1.4 J+ 1.6 J+ 2.6 J+ 3.7 J+ 1.6 J+ 3.3 J+ 2.3 J+ Molybdenum 7439-98-7 D p /L 5.07 4 31.6 23.8 3.4 0.8 4 Molybdenum 7439-98-7 T pg/L 5.66 4.1 J+ 34.5 23 J+ 3.3 0.85 5.4 Nickel 7440-02-0 D p /L 1.44 0.59 0.38 J 1.2 0.18 J+ 0.5 U 0.5 U Nickel 7440-02-0 T 100 02L pg/L 4.42 4.3 J+ 0.98 1.4 J+ 0.97 0.49 J 0.31 J+ Potassium 7440-09-7 T p /L 18800 28900 80200 56600 8420 4420 J 17000 Selenium 7782-49-2 D pg/L 19.9 20.2 2.7 1.6 0.49 J 0.5 U 0.24 J Selenium 7782-49-2 T 20 02L p /L 15.4 21 3.1 1.8 0.47 J 0.5 U 0.31 J Sodium 7440-23-5 T p /L 19800 21600 50300 40100 9950 6830 18200 Strontium 7440-24-6 D p /L 220 190 3300 1800 270 140 350 Strontium 7440-24-6 T pg/L 285 200 3300 1700 280 130 400 Thallium 7440-28-0 D p /L 0.2 U 0.1 U 0.018 J 0.1 U 0.027 J 0.1 U 0.1 U Thallium 7440-28-0 T 0.2 IMAC pg/L 0.2 U 0.1 UJ 0.025 J 0.017 J+ 0.1 U 0.1 U 0.1 U Vanadium 7440-62-2 D p /L 19 22.2 7.4 13.5 24.1 16 12.7 Vanadium 7440-62-2 T 0.3 IMAC pg/L 32.1 23.4 J+ 11.5 13.8 J+ 24 16.3 12.5 Zinc 7440-66-6 D p /L 6 6.3 J 10 U 6.3 J 10 U 10 U 3.6 J+ Zinc 7440-66-6 T 1000 02L pg/L 33 20 J+ 23 5.3 J+ 6.1 J 200 3.3 J+ Total Dissolved Solids TDS N 500000 02L p /L 160000 142000 946000 630000 159000 102000 214000 Total Organic Carbon TOC N pg/L 1300 990 J 4900 2000 790 J 1000 U 720 J Total Suspended Solids TSS N p /L 330000 16600 63200 12300 30100 6200 2500 U Alkalinity, CO3 ALK-CO3 N pg/L 86100 41800 309000 41800 27200 36300 57800 Alkalinity, HCO3 ALK-HCO3 N p /L 19900 5000 UJ 5000 U 5000 UJ 53900 34300 5000 U Alkalinity, lab ALK-LAB N p /L 106000 J+ 92600 638000 480000 81100 70600 100000 Chloride 16887-00-6 N 250000 02L p /L 2200 2600 6400 5100 2500 1700 4700 Fluoride 16984-48-8 N p /L - - - - - - - Nitro en, NO2 plus NO3 NO2-NO3 N p /L 48 20 U 73 71 530 480 200 Sulfate 14808-79-8 N 250000 02L pg/L 17000 16200 144000 90600 13100 7100 56300 Sulfide 18496-25-8 N p /L 100 U 100 U 100 U 100 U 100 U 100 U 100 U - Arsenic 7440-38-2 T 10 02L pg/L - - 0.5 UJ - - - - 0.464 J+ Chromium 7440-47-3 T 10 02L p /L 57.4 3.73 J+ Iron 7439-89-6 T 300 02L pg/L 130 47.1 J+ Manganese 7439-96-5 D p /L 0.719 J+ 0.544 J+ Manganese 7439-96-5 T 50 02L pg/L 5.89 J+ 1.51 J+ Page 3 of 16 Table 2-5 Groundwater Results within Waste Boundary Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: AB-3BR AB-3BR AB-3D AB-3D AB-4D AB-4D AB-5D AB-5D Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 Round 1 7/23/2015 9/17/2015 7/7/2015 9/17/2015 7/8/2015 9/17/2015 6/20/2015 7/8/2015 N N N N N N N N AB-3BR RV-AB-31BR-NS-3Q15 AB-3D RV-AB-3D-NS-3Q15 AB-4D RV-AB-4D-NS-3Q15 AB-5D AB-5D Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit As III 7784-46-5 T /L 0.301 J 0.5 UJ As V 10103-60-3 T /L 0.5 UJ 0.464 J+ Chromium VI 18540-29-9 D 0.07 DHHS /L 42 3.3 Chromium VI 18540-29-9 T 0.07 DHHS /L - - Fe II 1345-25-1 T /L 30 UJ 30 R Fe III 1309-37-1 T /L - Mn II 1344-43-0 T /L Mn IV 1313-13-9 T /L - Se IV 10102-18-8 T /L 1.18 J+ 2 U Se VI 13410-01-0 T /L 3.32 J+ - - - - 2 U Dissolved Oxygen DO N m /L 2.1 0.6 0.7 0.7 2.5 1.96 0.8 Temperature TEMP N Deg C 17.8 19.9 29.1 23.3 25.5 23.5 20.68 H PH N 6.5 8.5 02L SU 10.8 10.9 11.9 11.8 10.6 9.42 10.91 Turbidit , field TURB N NTU 416.5 9.9 119.7 4.5 20.64 14.71 3.27 Specific Conductivity field SC NPS/cm 454 333 3092 2256 316.6 147.3 430 Oxidation Reduction Potential ORP I N I mV 142.6 -127.5 -265.9 -195.7 59.4 41.4 -30.1 GW Depth TOC GW DEPTH-TOC N I ft - 40.39 - 28.09 - - - Notes: pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 4 of 16 Table 2-5 Groundwater Results within Waste Boundary Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: AB-5D AB-613RU AB-613RU AB-66RU AB-6S A13-6S AB-6S AB-7D Round 2 Round 1 Round 1 Round 2 Round 1 Round 1 Round 2 Round 1 9/15/2015 6/22/2015 7/2/2015 9/16/2015 6/22/2015 7/1/2015 9/17/2015 7/1/2015 N N N N N N N N RV-AB-5D-NS-3Q15 AB-613RU AB-613RU RV-AB-6BRU-NS-3Q15 AB-6S AB-6S RV-AB-6S-NS-3Q15 AB-7D Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D pg/L 150 71 J 310 100 U 4300 260 1000 Aluminum 7429-90-5 T p /L 1100 340 3000 440 5000 2000 1200 Antimony 7440-36-0 D pg/L 3.2 0.17 J 0.29 J 5.7 1.7 0.39 J 7.2 J+ Antimony7440-36-0 T 1 IMAC p /L 0.37 J 0.32 J 2.5 3 1.8 0.38 J 7.5 Arsenic 7440-38-2 D pg/L 0.24 J 0.25 J 0.21 J 0.15 J 0.88 0.68 1.9 Arsenic 7440-38-2 T 10 02L p /L 0.42 J+ 0.24 J 0.75 0.14 J 0.82 0.67 2.2 Barium 7440-39-3 D p /L 28 5.3 6.9 20 7.7 6.8 39 Barium 7440-39-3 T 700 02L p /L 24 5.6 38 9.6 9 9.4 41 Beryllium 7440-41-7 D pg/L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 UJ Beryllium 7440-41-7 T 4 IMAC p /L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 UJ Boron 7440-42-8 D pg/L 200 460 490 430 41 J 50 U 36 J Boron 7440-42-8 T 700 02L p /L 200 480 430 420 45 J 50 U 50 UJ Cadmium 7440-43-9 D pg/L 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U Cadmium 7440-43-9 T 2 02L p /L 0.08 U 0.08 U 0.026 J 0.08 U 0.08 U 0.08 U 0.08 U Calcium 7440-70-2 T pg/L 46300 41600 92800 46700 94400 22700 70100 Chromium 7440-47-3 D p /L 2.6 2 J+ 3.1 J 1.1 0.78 J+ 1.2 26.4 Chromium 7440-47-3 T 10 02L pg/L 3.8 2.4 J+ 8.1 3.1 J 1.2 J+ 5.2 24.7 Cobalt 7440-48-4 D p /L 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.45 J 0.5 UJ Cobalt 7440-48-4 T 1 IMAC pg/L 0.25 J 0.5 U 1.8 0.5 U 0.31 J 2.2 0.5 U Copper 7440-50-8 D p /L 0.24 J 5.4 0.3 J+ 1 U 1.7 J+ 4.6 1.3 J+ Copper 7440-50-8 T 1000 02L p /L 2.3 0.46 J 9.2 0.41 J 1.3 0.95 J 2.3 J+ Iron 7439-89-6 D p /L 50 U 50 U 52 50 U 50 U 50 U 50 U Iron 7439-89-6 T 300 02L p /L 470 85 970 100 730 2400 J+ 94 J+ Lead 7439-92-1 D p /L 0.1 U 0.72 0.1 U 0.1 U 0.1 UJ 0.71 0.1 UJ Lead 7439-92-1 T 15 02L pg/L 0.055 J 0.1 U 0.73 J+ 0.1 U 0.19 0.68 J+ 0.1 UJ Magnesium 7439-95-4 T p /L 6710 9370 4100 8290 57.9 J 519 100 U Manganese 7439-96-5 D pg/L 5 U 5 U 2.8 J 5 U 5 U 170 5 U Manganese 7439-96-5 T 50 02L p /L 7.2 4 J 25 3.2 J 12 220 4.6 J Mercury 7439-97-6 D pg/L 0.2 U 0.11 J+ 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L p /L 0.2 U 0.085 J+ 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Methane 74-82-8 N pg/L 4.4 J+ 1.6 J+ 10 UJ 1.5 J+ 201 J 348 2.7 J+ Molybdenum 7439-98-7 D p /L 3.9 1.2 1.7 5.2 8.7 4.2 8 J+ Molybdenum 7439-98-7 T pg/L 3.1 1.2 2.8 2.1 7.6 2 8.5 J+ Nickel 7440-02-0 D p /L 0.21 J 0.28 J 0.21 J+ 0.17 J 1.3 3.2 0.5 UJ Nickel 7440-02-0 T 100 02L pg/L 0.76 0.43 J+ 3.3 0.28 J 1.3 J+ 3.8 0.5 U Potassium 7440-09-7 T p /L 10600 4250 J 43400 21000 10200 5000 U 8150 Selenium 7782-49-2 D pg/L 0.3 J 0.5 U 0.5 U 0.52 2.8 0.57 0.76 Selenium 7782-49-2 T 20 02L p /L 0.23 J 0.5 U 0.27 J 0.29 J 2.6 0.41 J 0.77 Sodium 7440-23-5 T p /L 12500 9640 18300 12400 8820 7030 29500 Strontium 7440-24-6 D p /L 390 J- 250 290 490 210 48 300 Strontium 7440-24-6 T pg/L 340 270 650 330 230 46 290 Thallium 7440-28-0 D p /L 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.026 J 0.1 U Thallium 7440-28-0 T 0.2 IMAC pg/L 0.1 U - 0.1 U 0.1 U - 0.031 J 0.1 U Vanadium 7440-62-2 D p /L 12.6 12.1 11.4 9.3 24.3 7.2 41.1 Vanadium 7440-62-2 T 0.3 IMAC pg/L 13.7 11.9 18.6 8.9 25.2 15.3 40.5 Zinc 7440-66-6 D p /L 10 U 10 U 10 U 10 U 3.8 J 5.3 J 10 UJ Zinc 7440-66-6 T 1000 02L pg/L 2.9 J+ 10 U 49 J+ 10 U 10 U 12 J+ 10 UJ Total Dissolved Solids TDS N 500000 02L p /L 206000 247000 212000 258000 296000 97000 326000 Total Organic Carbon TOC N pg/L 820 J 1000 U 1000 U 880 J 1700 740 J 3300 Total Suspended Solids TSS N p /L 134000 8200 187000 200000 13900 80000 11100 Alkalinity, CO3 ALK-CO3 N pg/L 66800 27000 17000 50000 245000 5000 U 110000 Alkalinity, HCO3 ALK-HCO3 N p /L 17900 41600 92400 5000 U 5000 U 1600 J+ 69800 Alkalinity, lab ALK-LAB N p /L 84700 68600 109000 81200 245000 1600 J+ 180000 Chloride 16887-00-6 N 250000 02L p /L 4800 5300 5400 5600 8800 9000 7200 Fluoride 16984-48-8 N p /L - - - - - - - Nitro en, NO2 plus NO3 NO2-NO3 N p /L 290 48 J+ 120 38 16 J+ 20 U 130 Sulfate 14808-79-8 N 250000 02L pg/L 67300 83500 87000 95000 15700 13400 46500 Sulfide 18496-25-8 N p /L 100 U 100 U 100 U 100 U 100 U - 100 U 100 U Arsenic 7440-38-2 T 10 02L pg/L - - - - - 1.25 - 1.75 Chromium 7440-47-3 T 10 02L p /L 1.12 J+ 32.9 Iron 7439-89-6 T 300 02L pg/L 243 43.6 J+ Manganese 7439-96-5 D p /L 7.29 2 U Manganese 7439-96-5 T 50 02L pg/L 39 J+ 1.21 J+ Page 5 of 16 Table 2-5 Groundwater Results within Waste Boundary Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: AB-5D AB-6BRU AB-6BRU AB-6BRU AB-6S AB-6S AB-6S AB-7D Round 2 Round 1 Round 1 Round 2 Round 1 Round 1 Round 2 Round 1 9/15/2015 6/22/2015 7/2/2015 9/16/2015 6/22/2015 7/1/2015 9/17/2015 7/1/2015 N N N N N N N N RV-AB-5D-NS-3Q15 AB-6BRU AB-6BRU RV-AB-6BRU-NS-3Q15 AB-6S AB-6S RV-AB-6S-NS-3Q15 AB-7D Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit As III 7784-46-5 T /L 0.2 U 0.5 UJ 0.5 UJ As V 10103-60-3 T /L 0.235 1.25 1.75 Chromium VI 18540-29-9 D 0.07 DHHS /L - 0.21 26 Chromium VI 18540-29-9 T 0.07 DHHS /L 2 - - Fe II 1345-25-1 T /L 11.7 41 40 U Fe III 1309-37-1 T /L 20 U - - Mn II 1344-43-0 T /L 5 U Mn IV 1313-13-9 T /L 66.4 Se IV 10102-18-8 T /L 0.5 U 2.44 J+ 1.22 J+ Se VI 13410-01-0 T /L 0.5 U - - 1.56 J+ - 2 UJ Dissolved Oxygen DO N m /L 0.7 0.45 - 0.45 0.17 - 0.29 8.21 Temperature TEMP N Deg C 22.7 20.61 25 23.46 23.9 19.1 H PH N 6.5 8.5 02L SU 10.9 9.99 10.65 11.91 7.92 11.91 Turbidity, field TURB N NTU 8.8 3.25 9.78 18.8 45.78 8.25 S ecific Conductivit field SC NPS/cm 426.2 334 530 1100 152.8 905 Oxidation Reduction Potential ORP N I mV -83.6 -53.6 -37.6 -102.7 -30.8 -38.9 GW Depth TOC GW DEPTH-TOC N I ft 50.78 - - - - - Notes: pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 6 of 16 Table 2-5 Groundwater Results within Waste Boundary Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: AB-7D AB-7D AB-71 AB-71 AB-81D AB-8D AB-8D AB-8S Round 2 Round 2 Round 1 Round 2 Round 1 Round 1 Round 2 Round 1 9/16/2015 9/16/2015 7/7/2015 9/17/2015 6/17/2015 6/17/2015 9/16/2015 6/20/2015 N FD N N FD N N N RV-AB-7D-NS-3Q15 RV-AB-7D-FD-3Q15 AB-71 RV-AB-71-NS-3Q15 DUP-061715 AB-8D RV-AB-8D-NS-3Q15 AB-8S Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D pg/L 810 790 100 U 100 U 100 U 100 U 100 U 100 U Aluminum 7429-90-5 T p /L 1900 1800 530 1500 190 420 100 U 200 Antimony 7440-36-0 D pg/L 2.4 J+ 2.2 J+ 3.6 0.61 0.5 U 0.5 U 0.5 U 0.5 U Antimony7440-36-0 T 1 IMAC p /L 2.6 2.4 1 J+ 1 0.5 U 0.5 U 0.73 0.5 U Arsenic 7440-38-2 D pg/L 2.7 2.9 0.12 J 0.5 U 0.32 J 0.31 J 0.14 J 0.5 U Arsenic 7440-38-2 T 10 02L p /L 2.9 2.9 0.5 U 0.22 J 0.19 J 0.17 J 0.14 J 0.5 U Barium 7440-39-3 D p /L 29 28 33 36 44 44 46 130 Barium 7440-39-3 T 700 02L p /L 42 38 35 40 46 45 49 130 Beryllium 7440-41-7 D pg/L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.17 J Beryllium 7440-41-7 T 4 IMAC p /L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.18 J Boron 7440-42-8 D pg/L 50 U 50 U 50 U 50 U 470 470 420 240 J+ Boron 7440-42-8 T 700 02L p /L 50 U 50 U 50 U 29 J 440 440 450 220 Cadmium 7440-43-9 D pg/L 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.13 Cadmium 7440-43-9 T 2 02L p /L 0.08 U 0.08 U 0.036 J+ 0.08 U 0.08 U 0.08 U 0.08 U 0.16 Calcium 7440-70-2 T pg/L 49700 48600 2030 2270 61200 61300 50900 37700 Chromium 7440-47-3 D p /L 24 24.8 1.1 J+ 0.47 J 0.66 0.43 J 0.43 J 3.1 Chromium 7440-47-3 T 10 02L pg/L 26.4 26.1 0.9 J+ 0.68 0.9 1.4 5.5 3.8 Cobalt 7440-48-4 D p /L 0.5 U 0.5 U 1.5 1.3 0.58 0.61 0.59 0.56 Cobalt 7440-48-4 T 1 IMAC pg/L 0.46 J 0.4 J 1.6 2.2 0.66 0.73 1.2 0.55 Copper 7440-50-8 D p /L 1.5 1.7 1.4 2 1 U 0.58 J 0.28 J 0.3 J+ Copper 7440-50-8 T 1000 02L p /L 6.4 6.9 0.5 J+ 0.65 J 0.72 J 1.3 5.5 0.56 J+ Iron 7439-89-6 D p /L 50 U 50 U 50 U 50 U 76 60 180 50 U Iron 7439-89-6 T 300 02L p /L 690 710 380 450 190 300 190 160 Lead 7439-92-1 D p /L 0.2 0.19 0.06 J 0.21 0.1 U 0.1 U 0.1 U 0.1 U Lead 7439-92-1 T 15 02L pg/L 0.3 0.28 0.11 J+ 0.14 0.1 U 0.1 UJ 0.32 0.1 U Magnesium 7439-95-4 T p /L 111 108 726 805 12900 12700 11700 11700 Manganese 7439-96-5 D pg/L 5 U 5 U 77 84 130 130 120 140 Manganese 7439-96-5 T 50 02L p /L 23 22 85 100 140 140 120 150 Mercury 7439-97-6 D pg/L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L p /L 0.2 U 0.2 U 0.2 U 0.2 UJ 0.11 J+ 0.11 J+ 0.2 U 0.11 J+ Methane 74-82-8 N pg/L 2.1 J+ 2.4 J+ 10 UJ 1.9 J+ 6.5 J+ 2.7 J+ 2.4 J+ 10 UJ Molybdenum 7439-98-7 D p /L 8.1 8.4 0.5 U 0.5 U 1.2 1.2 0.6 0.5 U Molybdenum 7439-98-7 T pg/L 8.4 8.4 0.5 U 0.5 U 1.2 1.3 1.5 0.5 U Nickel 7440-02-0 D p /L 0.5 U 0.33 J 0.79 0.71 0.98 1 0.77 1.8 Nickel 7440-02-0 T 100 02L pg/L 1.1 1 0.76 1.1 J+ 1 1.3 2.5 2.1 Potassium 7440-09-7 T p /L 7970 7540 5000 U 5000 U 3680 J 3710 J 5320 5000 U Selenium 7782-49-2 D pg/L 0.66 0.64 0.5 U 0.5 U 0.37 J 0.36 J 0.33 J 1.2 Selenium 7782-49-2 T 20 02L p /L 0.7 0.67 0.5 U 0.5 U 0.34 J 0.34 J 0.36 J 1.2 Sodium 7440-23-5 T p /L 31000 31200 5050 6140 14000 14000 15400 14800 Strontium 7440-24-6 D p /L 260 250 40 34 490 490 490 510 Strontium 7440-24-6 T pg/L 290 270 34 37 500 490 510 510 Thallium 7440-28-0 D p /L 0.1 U 0.1 U 0.042 J+ 0.017 J 0.1 U 0.1 U 0.016 J 0.1 U Thallium 7440-28-0 T 0.2 IMAC pg/L 0.016 J 0.1 U 0.048 J+ 0.019 J 0.016 J 0.1 U 0.1 U 0.02 J Vanadium 7440-62-2 D p /L 44.8 47.7 1 U 1 U 2.3 2.3 1.3 0.37 J Vanadium 7440-62-2 T 0.3 IMAC pg/L 45.9 46.9 1 U 0.47 J 2.2 2.7 3.7 0.79 J Zinc 7440-66-6 D p /L 10 2.7 J 8.3 J+ 13 J+ 10 U 10 U 10 U 84 Zinc 7440-66-6 T 1000 02L pg/L 6.6 J+ 5.5 J+ 7.5 J 16 10 U 2.7 J+ 3.4 J+ 78 Total Dissolved Solids TDS N 500000 02L p /L 261000 257000 41000 39000 362000 361000 279000 274000 Total Organic Carbon TOC N pg/L 940 J 870 J 1000 U 1000 U 1000 U 1000 U 1000 U 1000 U Total Suspended Solids TSS N p /L 130000 108000 21200 36000 2500 U 5900 369000 13300 Alkalinity, CO3 ALK-CO3 N pg/L 32900 50000 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U Alkalinity, HCO3 ALK-HCO3 N p /L 5000 U 5000 U 9800 8100 82300 77300 37200 28500 Alkalinity, lab ALK-LAB N p /L 152000 165000 9800 8100 82300 77300 37200 28500 Chloride 16887-00-6 N 250000 02L p /L 6500 6400 1800 2300 5900 5800 6100 5300 Fluoride 16984-48-8 N p /L - - - - - - - - Nitro en, NO2 plus NO3 NO2-NO3 N p /L 96 220 51 100 20 U 20 U 22 J+ 200 Sulfate 14808-79-8 N 250000 02L pg/L 53500 53900 6300 10700 139000 136000 146000 132000 Sulfide 18496-25-8 N p /L 100 U 100 U 100 U 100 U 100 U 100 U 100 U 100 U Arsenic 7440-38-2 T 10 02L pg/L - - 0.5 UJ - - - - - Chromium 7440-47-3 T 10 02L p /L 7.86 Iron 7439-89-6 T 300 02L pg/L 115 Manganese 7439-96-5 D p /L 74.7 Manganese 7439-96-5 T 50 02L pg/L 89.9 J+ Page 7 of 16 Table 2-5 Groundwater Results within Waste Boundary Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: AB-7D AB-7D AB-71 AB-71 AB-8D AB-8D AB-8D AB-8S Round 2 Round 2 Round 1 Round 2 Round 1 Round 1 Round 2 Round 1 9/16/2015 9/16/2015 7/7/2015 9/17/2015 6/17/2015 6/17/2015 9/16/2015 6/20/2015 N FD N N FD N N N RV-AB-7D-NS-3Q15 RV-AB-7D-FD-3Q75 AB-71 RV-AB-71-NS-3Q75 DUP-061715 AB-8D RV-AB-8D-NS-3Q15 AB-8S Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit As III 7784-46-5 T /L 0.5 UJ As V 10103-60-3 T /L 0.5 UJ Chromium VI 18540-29-9 D 0.07 DHHS /L 0.38 Chromium VI 18540-29-9 T 0.07 DHHS /L - Fe II 1345-25-1 T /L 30 UJ Fe III 1309-37-1 T /L Mn II 1344-43-0 T /L Mn IV 1313-13-9 T /L Se IV 10102-18-8 T /L 2 UJ Se VI 13410-01-0 T /L 2 UJ - - - Dissolved Oxygen DO N m /L 4.6 2.39 1.2 0.2 1.16 Temperature TEMP N Deg C 23.2 29.9 20.7 21.6 24.83 H PH N 6.5 8.5 02L SU 11 5.83 5.7 6.3 5.68 Turbidity, field TURB N NTU 4.22 20.01 43 51.2 9.83 S ecific Conductivit field SC NPS/cm 755 40.4 60.6 438.5 372 Oxidation Reduction Potential ORP I N I mV 1 74.7 217.1 193.2 -2.5 222 GW Depth TOC GW DEPTH-TOC N I I ft I - - 18.88 25.63 - Notes: pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 8 of 16 Table 2-5 Groundwater Results within Waste Boundary Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: AB-8S AS-1 D AS-1 D AS-1 D AS -IS AS-1 S AS -IS AS-21D Round 2 Round 1 Round 1 Round 2 Round 1 Round 1 Round 2 Round 1 9/15/2015 6/5/2015 7/1/2015 9/8/2015 6/5/2015 7/1/2015 9/8/2015 6/8/2015 N N N N N N N N RV-AB-8S-NS-3Q15 AS-1D AS-1D RV-AS-1D-NS-3Q15 AS-1S AS-1S RV-AS-1S-NS-3Q15 AS-21D Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D pg/L 100 U 2820 3000 10 U 100 U 556 Aluminum 7429-90-5 T p /L 4100 3520 3100 942 8200 759 Antimony 7440-36-0 D pg/L 0.5 U 2.7 3.7 0.23 J 0.29 J 1.3 J+ Antimony7440-36-0 T 1 IMAC p /L 0.5 U 3 3.3 0.26 J 0.55 J+ 1 J+ Arsenic 7440-38-2 D pg/L 0.5 U 0.32 J 0.39 J 0.95 1.9 0.43 J Arsenic 7440-38-2 T 10 02L p /L 0.38 J 0.68 0.46 J+ 1.4 6.4 0.66 Barium 7440-39-3 D p /L 110 47 50 95 91 42 Barium 7440-39-3 T 700 02L p /L 160 51 51 100 130 50 Beryllium 7440-41-7 D pg/L 0.11 J 0.2 U 0.11 J 0.2 U 0.2 U 0.2 U Beryllium 7440-41-7 T 4 IMAC p /L 0.45 0.2 U 0.2 U 0.2 U 0.25 0.2 U Boron 7440-42-8 D pg/L 250 50 U 50 U 1900 2000 50 U Boron 7440-42-8 T 700 02L p /L 240 50 U 50 U 2200 1400 28 J Cadmium 7440-43-9 D pg/L 0.11 0.08 U 0.08 U 0.031 J 0.055 J 0.08 U Cadmium 7440-43-9 T 2 02L p /L 0.12 0.08 U 0.08 U 0.054 J 0.086 0.08 U Calcium 7440-70-2 T pg/L 40100 111000 116000 167000 M6 147000 69900 M1 Chromium 7440-47-3 D p /L 3.1 830 838 0.66 J+ 0.17 J 20.7 Chromium 7440-47-3 T 10 02L pg/L 26.2 903 868 6.1 3.2 22.5 Cobalt 7440-48-4 D p /L 0.31 J 0.5 U 0.15 J 5.3 5.4 0.5 U Cobalt 7440-48-4 T 1 IMAC p /L 3.6 0.18 J 0.22 J+ 5.4 8.1 0.2 J Copper 7440-50-8 D p /L 12.2 4.1 J+ 22.3 1.5 J+ 1.7 1 UJ Copper 7440-50-8 T 1000 02L p /L 21.7 5.7 J+ 21.7 1.5 J+ 3.8 J+ 3.3 J+ Iron 7439-89-6 D p /L 50 U 100 38 J 50 U 50 U 50 U Iron 7439-89-6 T 300 02L p /L 3500 107 160 J+ 660 8500 221 Lead 7439-92-1 D p /L 1.2 0.053 J 0.12 0.083 J 0.1 U 0.1 U Lead 7439-92-1 T 15 02L pg/L 0.93 0.11 0.16 J+ 0.14 1.3 J+ 0.1 U Magnesium 7439-95-4 T p /L 9920 100 U 100 U 34000 M1 31200 258 Manganese 7439-96-5 D pg/L 89 5 U 5 U 1700 2300 5 U Manganese 7439-96-5 T 50 02L p /L 120 3.7 J 8 J+ 1900 2500 8.2 Mercury 7439-97-6 D pg/L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L p /L 0.2 0.2 U 0.2 U 0.2 U 0.14 J 0.2 U Methane 74-82-8 N pg/L 2.2 J+ 810 J- 827 100 130 J+ 10 U Molybdenum 7439-98-7 D p /L 0.5 U 50.5 54 132 213 9.9 Molybdenum 7439-98-7 T pg/L 0.5 U 57.4 55.3 136 195 10.5 Nickel 7440-02-0 D p /L 1.8 J+ 0.5 U 0.42 J 2.6 1.4 0.5 U Nickel 7440-02-0 T 100 02L pg/L 13.3 2.2 0.75 J+ 5.2 2.7 0.95 Potassium 7440-09-7 T p /L 5000 U 14200 14900 9550 7970 6690 Selenium 7782-49-2 D pg/L 0.92 0.94 1.2 0.5 U 0.34 J 1.2 Selenium 7782-49-2 T 20 02L p /L 0.88 1.1 1.1 0.49 J 0.48 J 1.2 Sodium 7440-23-5 T p /L 13500 30500 36100 12900 11800 25000 Strontium 7440-24-6 D p /L 560 690 710 2600 3000 530 Strontium 7440-24-6 T pg/L 630 730 740 2800 2200 590 Thallium 7440-28-0 D p /L 0.017 J 0.1 U 0.1 U 0.065 J 0.056 J 0.1 U Thallium 7440-28-0 T 0.2 IMAC pg/L 0.036 J 0.1 U 0.1 U 0.076 J 0.075 J 0.1 U Vanadium 7440-62-2 D p /L 1 U 13.4 16.1 0.48 J+ 0.73 J 31.8 Vanadium 7440-62-2 T 0.3 IMAC pg/L 20.2 14.4 14.5 1.6 J+ 7.2 J+ 34.6 Zinc 7440-66-6 D p /L 8.4 J+ 10 U 12 11 J+ 6.5 J 10 U Zinc 7440-66-6 T 1000 02L pg/L 16 2.9 J 16 J+ 12 31 J+ 5.3 J+ Total Dissolved Solids TDS N 500000 02L p /L 25000 U 390000 J- 406000 750000 J- 789000 280000 J- Total Organic Carbon TOC N pg/L 21100 2100 1800 2300 2800 2400 Total Suspended Solids TSS N p /L 513000 9100 J- 12600 J+ 390000 J- 2070000 11000 J- Alkalinity, CO3 ALK-CO3 N pg/L 5000 U 10000 U 235000 10000 U 5000 U 87000 Alkalinity, HCO3 ALK-HCO3 N p /L 13200 10000 U 5000 U 350000 338000 10000 U Alkalinity, lab ALK-LAB N p /L 13200 470000 313000 350000 338000 150000 Chloride 16887-00-6 N 250000 02L p /L 5400 5700 6600 18300 17200 4100 Fluoride 16984-48-8 N p /L - - - - - - Nitro en, NO2 plus NO3 NO2-NO3 N p /L 170 94 J+ 26 J- 320 J+ 60 J- 20 U Sulfate 14808-79-8 N 250000 02L pg/L 138000 21300 22700 231000 218000 26000 Sulfide 18496-25-8 N p /L 100 U 100 U - 100 U 1000 UJ - 100 U 100 U Arsenic 7440-38-2 T 10 02L pg/L - - 0.354 - - 1.21 - - Chromium 7440-47-3 T 10 02L p /L 974 0.774 J+ Iron 7439-89-6 T 300 02L pg/L 87.7 J 90.4 J Manganese 7439-96-5 D p /L 0.322 J 2280 Manganese 7439-96-5 T 50 02L pg/L 1.62J+ 2200 Page 9 of 16 Table 2-5 Groundwater Results within Waste Boundary Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: AB-8S AS-1D AS-1D AS-1D AS -IS AS-1S AS -IS AS-211) Round 2 Round 1 Round 1 Round 2 Round 1 Round 1 Round 2 Round 1 9/15/2015 6/5/2015 7/1/2015 9/8/2015 6/5/2015 7/1/2015 9/8/2015 6/8/2015 N N N N N N N N RV-AB-8S-NS-3Q15 AS-1D AS-1D RV-AS-1D-NS-3Q15 AS -IS AS -IS RV-AS-1S-NS-3Q15 AS-211) Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit As III 7784-46-5 T /L 0.215 J- 0.5 UJ As V 10103-60-3 T /L 0.5 U 1.21 Chromium VI 18540-29-9 D 0.07 DHHS /L 810 0.031 Chromium VI 18540-29-9 T 0.07 DHHS /L - - Fe II 1345-25-1 T /L 40 U 40 U Fe III 1309-37-1 T /L - - Mn II 1344-43-0 T /L Mn IV 1313-13-9 T /L Se IV 10102-18-8 T /L 2 UJ 2 UJ Se VI 13410-01-0 T /L 2 UJ - 2 UJ Dissolved Oxygen DO N m /L 0.7 6.6 1.3 Temperature TEMP N Deg C 26.5 35.2 31.6 H PH N 6.5 8.5 02L SU 5.6 11.4 6.4 Turbidity, field TURB N NTU 30.4 6.2 14.2 Specific Conductivity field SC N S/cm 342.5 1592 1167 Oxidation Reduction Potential ORP N mV 165.1 36.6 142.8 GW Depth TOC GW_DEPTH-TOCI N I ft 1 26.65 - - Notes: pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 10 of 16 Table 2-5 Groundwater Results within Waste Boundary Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: AS-2D AS-21D AS-2S AS-2S AS-2S AS-3D AS-3D AS-3D Round 1 Round 2 Round 1 Round 1 Round 2 Round 1 Round 1 Round 2 7/1/2015 9/4/2015 6/5/2015 7/1/2015 9/4/2015 6/5/2015 7/1/2015 9/4/2015 N N N N N N N N AS-2D RV-AS-2D-NS-3Q15 AS-2S AS-2S RV-AS-2S-NS-3Q15 AS-3D AS-3D RV-AS-3D-NS-3Q15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D pg/L 550 9.8 J 100 U 492 220 Aluminum 7429-90-5 T p /L 600 4060 15300 926 17400 J Antimony 7440-36-0 D pg/L 2.6 0.18 J 0.17 J 1.2 1.3 Antimony7440-36-0 T 1 IMAC p /L 2.5 0.21 J 2.3 1.6 1.5 Arsenic 7440-38-2 D pg/L - 0.28 J 0.5 U 0.25 J 0.87 0.86 Arsenic 7440-38-2 T 10 02L p /L 0.34 J 0.42 J 2.8 0.97 0.96 Barium 7440-39-3 D p /L 28 150 93 14 19 Barium 7440-39-3 T 700 02L p /L 31 170 300 21 600 J Beryllium 7440-41-7 D pg/L 0.2 U 0.18 J 0.12 J 0.2 U 0.2 U Beryllium 7440-41-7 T 4 IMAC p /L 0.2 U 0.21 1.1 0.2 U 0.2 U Boron 7440-42-8 D pg/L 50 U 50 U 50 U 50 U 50 U Boron 7440-42-8 T 700 02L p /L 50 U 50 U 50 U 27 J 50 U Cadmium 7440-43-9 D pg/L 0.08 U 0.11 0.12 0.08 U 0.08 U Cadmium 7440-43-9 T 2 02L p /L 0.08 U 0.13 0.26 0.08 U 0.08 U Calcium 7440-70-2 T pg/L 50200 4870 4840 20400 447000 J Chromium 7440-47-3 D p /L 17 10.2 0.31 J+ 20.9 14.8 Chromium 7440-47-3 T 10 02L pg/L 17.4 44.8 36.4 23.5 18.8 J Cobalt 7440-48-4 D p /L 0.5 U 10.1 8 0.5 U 0.5 U Cobalt 7440-48-4 T 1 IMAC pg/L 0.5 U 12.4 24.3 0.16 J 0.45 J Copper 7440-50-8 D p /L 2.6 J+ 0.45 J+ 0.66 J+ 1.5 J+ 0.85 J+ Copper 7440-50-8 T 1000 02L p /L 3.6 J+ 3.9 J+ 19.8 J+ 3.5 J+ 4.1 J+ Iron 7439-89-6 D p /L 38 J 314 500 50 U 50 U Iron 7439-89-6 T 300 02L p /L 90 2090 9000 279 10000 J Lead 7439-92-1 D p /L 0.1 U 0.056 J 0.1 0.1 U 0.1 U Lead 7439-92-1 T 15 02L pg/L 0.079 J+ 1.4 12.2 J+ 0.094 J 1.1 J+ Magnesium 7439-95-4 T p /L 117 1310 1930 740 14300 J Manganese 7439-96-5 D pg/L 5 U 580 460 5 U 3.6 J Manganese 7439-96-5 T 50 02L p /L 3.6 J 640 810 12 1700 J Mercury 7439-97-6 D pg/L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L p /L 0.2 U 0.2 U 0.13 J 0.2 U 0.2 U Methane 74-82-8 N pg/L 3 J+ 5400 J- 6570 10 U 3.3 J+ Molybdenum 7439-98-7 D p /L 10 0.49 J 0.5 U 21.7 15.7 Molybdenum 7439-98-7 T pg/L 9.9 1.5 1.2 22.1 15.9 Nickel 7440-02-0 D p /L 0.25 J+ 20.9 1.7 J+ 0.5 U 0.31 J+ Nickel 7440-02-0 T 100 02L pg/L 0.29 J 31.1 21.4 1.6 2.5 J Potassium 7440-09-7 T p /L 5280 4700 J 5000 U 3760 J 3050 J Selenium 7782-49-2 D pg/L 0.89 0.5 U 0.5 U 0.59 0.5 J Selenium 7782-49-2 T 20 02L p /L 0.9 0.5 U 0.55 0.66 0.54 Sodium 7440-23-5 T p /L 23400 8280 8610 12400 11600 Strontium 7440-24-6 D p /L 400 82 75 120 130 Strontium 7440-24-6 T pg/L 430 88 110 140 950 J Thallium 7440-28-0 D p /L 0.1 U 0.085 J 0.044 J 0.1 U 0.1 U Thallium 7440-28-0 T 0.2 IMAC pg/L 0.1 U 0.11 0.27 0.1 U 0.1 U Vanadium 7440-62-2 D p /L 39.5 1 U 0.35 J 17.2 16 Vanadium 7440-62-2 T 0.3 IMAC pg/L 40.2 3.9 51.9 18.2 17.2 Zinc 7440-66-6 D p /L 4.5 J+ 110 J+ 5.8 J+ 10 U 3.4 J+ Zinc 7440-66-6 T 1000 02L pg/L 3.9 J+ 120 45 6.4 J 470 J Total Dissolved Solids TDS N 500000 02L p /L 242000 J+ 62000 J- 86000 J+ 110000 J- 142000 J+ Total Organic Carbon TOC N pg/L 1400 1500 1000 1000 UJ 1000 U Total Suspended Solids TSS N p /L 5800 120000 J- 3710000 4300 J- 47300 J Alkalinity, CO3 ALK-CO3 N pg/L 73200 10000 U 5000 U 37000 8200 J Alkalinity, HCO3 ALK-HCO3 N p /L 5000 U 42000 28900 18000 55100 Alkalinity, lab ALK-LAB N p /L 143000 42000 28900 66000 63300 Chloride 16887-00-6 N 250000 02L p /L 3000 2600 2400 3100 2700 Fluoride 16984-48-8 N p /L - - - - - Nitro en, NO2 plus NO3 NO2-NO3 N p /L 20 UJ 20 U 20 UJ 20 UJ 84 J Sulfate 14808-79-8 N 250000 02L pg/L 17500 5200 1100 18000 14200 Sulfide 18496-25-8 N p /L - 100 U 500 U - 100 U 100 U - 100 U Arsenic 7440-38-2 T 10 02L pg/L 0.304 - - 0.5 U - - 0.685 - Chromium 7440-47-3 T 10 02L p /L 22.5 2.15 28.3 Iron 7439-89-6 T 300 02L pg/L 204 170 62.9 J+ Manganese 7439-96-5 D p /L 2 U 674 0.0955 J Manganese 7439-96-5 T 50 02L pg/L 5.25 J+ 662 5.85 J+ Page 11 of 16 Table 2-5 Groundwater Results within Waste Boundary Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: AS-2113 AS-2113 AS-2S AS-2S AS-2S AS-3113 AS-3113 AS-3113 Round 1 Round 2 Round 1 Round 1 Round 2 Round 1 Round 1 Round 2 7/1/2015 9/4/2015 6/5/2015 7/1/2015 9/4/2015 6/5/2015 7/1/2015 9/4/2015 N N N N N N N N AS-2113 RV-AS-2D-NS-3Q15 AS-2S AS-2S RV-AS-2S-NS-3Q15 AS-3113 AS-3113 RV-AS-3D-NS-3Q15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit As III 7784-46-5 T /L 0.5 UJ 0.5 UJ 0.5 UJ As V 10103-60-3 T /L 0.304 J 0.5 U 0.685 Chromium VI 18540-29-9 D 0.07 DHHS /L 19 0.014 J 19 Chromium VI 18540-29-9 T 0.07 DHHS /L - - - Fe II 1345-25-1 T /L 40 U 144 40 U Fe III 1309-37-1 T /L - - - Mn II 1344-43-0 T /L Mn IV 1313-13-9 T /L - Se IV 10102-18-8 T /L 0.999 J+ 2 UJ 1.1 J+ Se VI 13410-01-0 T /L 2 UJ - 2 UJ - 2 UJ Dissolved Oxygen DO N m /L 3.02 0.5 6.2 Temperature TEMP N Deg C 20.92 28.1 23.9 H PH N 6.5 8.5 02L SU 11.57 5.3 10.3 Turbidity, field TURB N NTU 9.27 12 10 Specific Conductivity field SC NPS/cm 807 100 222.9 Oxidation Reduction Potential ORP I N I mV -88.8 172 40.2 GW Depth TOC GW DEPTH-TOC N I I ft - - - Notes: pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 12 of 16 Table 2-5 Groundwater Results within Waste Boundary Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: AS-3D AS-3S AS-3SA AS-3SA C-1BRU C-21D C-21D C-2D Round 2 Round 1 Round 1 Round 2 Round 2 Round 1 Round 1 Round 2 9/4/2015 7/7/2015 7/7/2015 9/4/2015 9/15/2015 6/19/2015 6/25/2015 9/18/2015 FD N N N N N N N RV-AS-3D-FD-3Q15 AS-3S AS-3SA RV-AS-3SA-NS-3Q15 RV-C-1BRU-NS-3Q15 C-21D C-21D RV-C-2D-NS-3Q15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D pg/L 230 260 450 280 67 J 56 J Aluminum 7429-90-5 T p /L 380 J 1200 690 J+ 960 170 320 Antimony 7440-36-0 D pg/L 1.2 1.8 0.48 J 3.2 0.5 U 0.49 J Antimony7440-36-0 T 1 IMAC p /L 1.4 1.7 0.66 3.1 0.5 U 0.86 Arsenic 7440-38-2 D pg/L 0.86 0.78 0.22 J 0.3 J 1.3 0.95 Arsenic 7440-38-2 T 10 02L p /L 0.9 0.93 0.25 J 0.34 J 1.3 J+ 1.2 Barium 7440-39-3 D p /L 20 53 45 460 18 23 Barium 7440-39-3 T 700 02L p /L 27 J 59 48 510 19 20 Beryllium 7440-41-7 D pg/L 0.2 U 0.2 U 0.1 J 0.2 U 0.2 U 0.2 U Beryllium 7440-41-7 T 4 IMAC p /L 0.2 U 0.073 J 0.11 J 0.2 U 0.2 U 0.2 U Boron 7440-42-8 D pg/L 50 U 430 940 50 U 50 U 50 U Boron 7440-42-8 T 700 02L p /L 50 U 410 980 50 U 50 U 50 U Cadmium 7440-43-9 D pg/L 0.08 U 0.025 J 0.1 0.08 U 0.055 J 0.08 U Cadmium 7440-43-9 T 2 02L p /L 0.08 U 0.029 J 0.07 J 0.08 U 0.08 U 0.08 U Calcium 7440-70-2 T pg/L 21600 J 42200 888 524000 23800 25100 Chromium 7440-47-3 D p /L 14.6 2 J+ 0.44 J 5.3 2.7 J+ 2.1 Chromium 7440-47-3 T 10 02L pg/L 15.3 J 3.6 1 J+ 6.3 2.5 J+ 2.9 J+ Cobalt 7440-48-4 D p /L 0.5 U 0.35 J 12.2 0.16 J 0.5 U 0.5 U Cobalt 7440-48-4 T 1 IMAC pg/L 0.15 J 0.72 10.8 0.26 J 0.5 U 0.3 J Copper 7440-50-8 D p /L 0.93 J+ 1.8 2.9 9 0.58 J+ 6.7 Copper 7440-50-8 T 1000 02L p /L 1.9 J+ 8.2 1.9 6.3 J+ 1.6 J+ 5.7 Iron 7439-89-6 D p /L 50 U 30 J 50 U 50 U 50 U 50 U Iron 7439-89-6 T 300 02L p /L 170 J 990 270 J+ 220 J+ 56 J+ 210 Lead 7439-92-1 D p /L 0.1 U 0.075 J 0.1 U 1.3 0.1 U 0.7 Lead 7439-92-1 T 15 02L pg/L 0.12 J+ 0.42 J+ 0.18 0.86 J+ 0.1 U 0.15 Magnesium 7439-95-4 T p /L 1140 J 1940 944 110 3150 3510 Manganese 7439-96-5 D pg/L 3.8 J 720 1200 5 U 7 6.4 Manganese 7439-96-5 T 50 02L p /L 181 730 1100 J+ 6 9.1 12 Mercury 7439-97-6 D pg/L 0.2 U 0.2 U 0.18 J 0.2 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L p /L 0.2 U 0.2 U 0.57 0.2 U 0.085 J+ 0.2 U Methane 74-82-8 N pg/L 3.5 J+ 0.66 J+ 106 3.1 J+ 1.8 J+ 2.4 J+ Molybdenum 7439-98-7 D p /L 15.3 4.8 0.5 U 24.4 1 0.73 Molybdenum 7439-98-7 T pg/L 15.6 4.6 0.5 U 21.8 1.1 J+ 0.85 Nickel 7440-02-0 D p /L 0.38 J+ 0.31 J 2.7 1.7 0.95 J+ 0.8 Nickel 7440-02-0 T 100 02L pg/L 0.64 J 0.87 2.3 2.2 J+ 0.91 J+ 1.4 Potassium 7440-09-7 T p /L 2650 J 4060 J 5000 U 302000 5000 U 5000 U Selenium 7782-49-2 D pg/L 0.49 J 2.1 1.3 0.79 0.5 UJ 0.5 U Selenium 7782-49-2 T 20 02L p /L 0.56 2 1.2 0.73 0.5 U 0.5 U Sodium 7440-23-5 T p /L 12300 144000 17400 247000 11900 11200 Strontium 7440-24-6 D p /L 130 550 9.8 2000 170 180 Strontium 7440-24-6 T pg/L 140 J 560 9.2 2200 170 150 Thallium 7440-28-0 D p /L 0.1 U 0.06 J 0.033 J 0.1 U 0.1 U 0.1 U Thallium 7440-28-0 T 0.2 IMAC pg/L 0.1 U 0.064 J 0.034 J 0.018 J 0.1 U 0.1 U Vanadium 7440-62-2 D p /L 15.5 3.9 1 U 1 U 9.5 7.5 Vanadium 7440-62-2 T 0.3 IMAC pg/L 16.6 4.9 0.4 J 0.85 J 10.9 8.9 Zinc 7440-66-6 D p /L 2.6 J+ 17 31 10 U 10 U 2.6 J Zinc 7440-66-6 T 1000 02L pg/L 14 J+ 21 10 9.8 J+ 3.3 J+ 12 Total Dissolved Solids TDS N 500000 02L p /L 163000 J+ 519000 92000 2540000 152000 J+ 178000 Total Organic Carbon TOC N pg/L 1000 U 1600 4000 U 8400 530 J 1000 U Total Suspended Solids TSS N p /L 10200 J 49800 212000 J- 42300 5500 182000 Alkalinity, CO3 ALK-CO3 N pg/L 2700 J 5000 U 5000 U 134000 3600 J 5000 U Alkalinity, HCO3 ALK-HCO3 N p /L 56400 254000 6400 5000 U 98700 104000 Alkalinity, lab ALK-LAB N p /L 59100 254000 6400 2180000 102000 104000 Chloride 16887-00-6 N 250000 02L p /L 2700 12900 13800 26100 2200 2500 Fluoride 16984-48-8 N p /L - - - - - 91 J Nitrogen, NO2 plus NO3 NO2-NO3 N p /L 20 UJ 60 12 J- 96 25 32 Sulfate 14808-79-8 N 250000 02L pg/L 13900 99300 16300 1200 1900 2500 Sulfide 18496-25-8 N p /L 100 U - 100 U 100 U 100 U 100 U 100 U Arsenic 7440-38-2 T 10 02L pg/L - 0.834 J+ - - - - - Chromium 7440-47-3 T 10 02L p /L 3.13 Iron 7439-89-6 T 300 02L pg/L 40.8 J+ Manganese 7439-96-5 D p /L 731 Manganese 7439-96-5 T 50 02L pg/L 878 J+ Page 13 of 16 Table 2-5 Groundwater Results within Waste Boundary Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: AS-3113 AS-3S AS-3SA AS-3SA C-1 BRU C-2113 C-2113 C-2113 Round 2 Round 1 Round 1 Round 2 Round 2 Round 1 Round 1 Round 2 9/4/2015 7/7/2015 7/7/2015 9/4/2015 9/15/2015 6/19/2015 6/25/2015 9/18/2015 FD N N N N N N N RV-AS-3D-FD-3Q15 AS-3S AS-3SA RV-AS-3SA-NS-3Q15 RV-C-1BRU-NS-3Q15 C-2D C-2D RV-C-2D-NS-3Q15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit As III 7784-46-5 T /L 0.5 UJ 0.2 U As V 10103-60-3 T /L 0.834 J+ 1.18 J+ Chromium VI 18540-29-9 D 0.07 DHHS /L 1.6 - Chromium VI 18540-29-9 T 0.07 DHHS /L - 2.53 Fe II 1345-25-1 T /L 30 UJ 29 J- Fe III 1309-37-1 T /L 20 U Mn II 1344-43-0 T /L 11.1 Mn IV 1313-13-9 T /L 14.5 Se IV 10102-18-8 T /L 2 UJ 0.5 U Se VI 13410-01-0 T /L 2.65 J+ - - - 0.5 U Dissolved Oxygen DO N m /L - 1.65 2 4.35 - 3.72 Temperature TEMP N Deg C 32.1 24.3 20.11 24.4 H PH N 6.5 8.5 02L SU 6.98 12.3 9.36 7.3 Turbidity, field TURB N NTU 48.37 9.7 7.62 46.32 Specific Conductivity field SC NPS/cm 717 9086 703 226.4 Oxidation Reduction Potential ORP I N I mV 57.9 -96 48.9 147.9 GW Depth TOC GW DEPTH-TOC N I I I ft - 67.23 - - Notes: pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 14 of 16 Table 2-5 Groundwater Results within Waste Boundary Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: C-213 C-2S C-2S C-2S C-2S Round 2 Round 1 Round 1 Round 2 Round 2 9/18/2015 6/19/2015 6/25/2015 9/17/2015 9/17/2015 FD N N FD N RV-C-2D-FD-3Q15 C-2S C-2S RV-C-2S-FD-3Q15 RV-C-2S-NS-3Q15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D pg/L 55 J 1600 1700 1700 Aluminum 7429-90-5 T p /L 400 1900 4400 2800 Antimony 7440-36-0 D pg/L 0.38 J 0.5 U 0.5 U 0.5 U Antimony7440-36-0 T 1 IMAC p /L 0.7 0.5 U 0.5 U 0.5 U Arsenic 7440-38-2 D pg/L 0.85 0.86 1.2 1.2 Arsenic 7440-38-2 T 10 02L p /L 1 0.95 J+ 1.3 1.1 Barium 7440-39-3 D p /L 22 35 37 37 Barium 7440-39-3 T 700 02L p /L 21 36 46 44 Beryllium 7440-41-7 D pg/L 0.2 U 2.1 1.9 2 Beryllium 7440-41-7 T 4 IMAC p /L 0.2 U 1.9 1.9 1.9 Boron 7440-42-8 D pg/L 50 U 170 J+ 170 170 Boron 7440-42-8 T 700 02L p /L 50 U 170 140 160 Cadmium 7440-43-9 D pg/L 0.08 U 0.21 0.18 0.17 Cadmium 7440-43-9 T 2 02L p /L 0.08 U 0.21 0.21 0.19 Calcium 7440-70-2 T pg/L 24600 11800 10700 10800 Chromium 7440-47-3 D p /L 2.4 0.51 J+ 5.7 8.2 Chromium 7440-47-3 T 10 02L pg/L 3.2 J+ 0.64 J+ 5.6 15.8 Cobalt 7440-48-4 D p /L 0.5 U 42.5 32.4 32.5 Cobalt 7440-48-4 T 1 IMAC pg/L 0.3 J 39.7 37.9 38.6 Copper 7440-50-8 D p /L 1 5.9 J+ 9 5.4 Copper 7440-50-8 T 1000 02L p /L 5.1 5.8 J+ 9.7 7 Iron 7439-89-6 D p /L 50 U 50 U 140 69 Iron 7439-89-6 T 300 02L p /L 260 140 J+ 1400 640 Lead 7439-92-1 D p /L 0.05 J 0.17 J+ 0.52 0.14 Lead 7439-92-1 T 15 02L pg/L 0.13 0.2 1 0.58 Magnesium 7439-95-4 T p /L 3590 4640 4310 4370 Manganese 7439-96-5 D pg/L 6.2 580 600 590 Manganese 7439-96-5 T 50 02L p /L 13 600 560 600 Mercury 7439-97-6 D pg/L 0.2 U 0.2 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L p /L 0.2 U 0.27 J+ 0.2 UJ 0.2 UJ Methane 74-82-8 N pg/L 2.4 J+ 10 UJ 3.8 J+ 3.4 J+ Molybdenum 7439-98-7 D p /L 0.68 0.5 U 0.5 U 0.16 J Molybdenum 7439-98-7 T pg/L 0.8 0.5 U 0.14 J 0.43 J Nickel 7440-02-0 D p /L 0.78 25.7 27.8 30.2 Nickel 7440-02-0 T 100 02L pg/L 1.6 25 27.9 J+ 36.5 J+ Potassium 7440-09-7 T p /L 5000 U 8380 7720 7810 Selenium 7782-49-2 D pg/L 0.5 U 1.5 2.5 2.5 Selenium 7782-49-2 T 20 02L p /L 0.5 U 1.5 1.5 1.5 Sodium 7440-23-5 T p /L 11500 4040 J 3760 J 3770 J Strontium 7440-24-6 D p /L 180 520 540 540 Strontium 7440-24-6 T pg/L 150 530 460 510 Thallium 7440-28-0 D p /L 0.1 U 0.095 J 0.077 J 0.08 J Thallium 7440-28-0 T 0.2 IMAC pg/L 0.1 U 0.09 J 0.093 J 0.087 J Vanadium 7440-62-2 D p /L 7 1 U 1 U 1 U Vanadium 7440-62-2 T 0.3 IMAC pg/L 8 0.52 J 1.3 0.87 J Zinc 7440-66-6 D p /L 4.2 J 94 J+ 86 85 Zinc 7440-66-6 T 1000 02L pg/L 8.4 J 89 J+ 62 94 Total Dissolved Solids TDS N 500000 02L p /L 161000 160000 J+ 138000 133000 Total Organic Carbon TOC N pg/L 1000 U 600 J 1000 U 1000 U Total Suspended Solids TSS N p /L 6000 14800 703000 267000 Alkalinity, CO3 ALK-CO3 N pg/L 5000 U 5000 U 5000 U 5000 U Alkalinity, HCO3 ALK-HCO3 N p /L 119000 5000 U 5000 U 5000 U Alkalinity, lab ALK-LAB N p /L 119000 5000 U 5000 U 5000 U Chloride 16887-00-6 N 250000 02L p /L 2500 3200 3100 3100 Fluoride 16984-48-8 N p /L 92 J - - - Nitro en, NO2 plus NO3 NO2-NO3 N p /L 29 3600 J+ 3400 3400 Sulfate 14808-79-8 N 250000 02L pg/L 2500 60400 57300 56900 Sulfide 18496-25-8 N p /L 100 U 100 U 100 U 100 U Arsenic 7440-38-2 T 10 02L pg/L - - - - Chromium 7440-47-3 T 10 02L p /L Iron 7439-89-6 T 300 02L pg/L Manganese 7439-96-5 D p /L Manganese 7439-96-5 T 50 02L pg/L Page 15 of 16 Table 2-5 Groundwater Results within Waste Boundary Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: C-211) C-2S C-2S C-2S C-2S Round 2 Round 1 Round 1 Round 2 Round 2 9/18/2015 6/19/2015 6/25/2015 9/17/2015 9/17/2015 FD N N FD N RV-C-2D-FD-3Q15 C-2S C-2S RV-C-2S-FD-3Q15 RV-C-2S-NS-3Q15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit As III 7784-46-5 T /L 0.2 U As V 10103-60-3 T /L 0.2 U Chromium VI 18540-29-9 D 0.07 DHHS /L - Chromium VI 18540-29-9 T 0.07 DHHS /L 0.273 Fe II 1345-25-1 T /L 20 U Fe III 1309-37-1 T /L 9.1 J- Mn II 1344-43-0 T /L 688 Mn IV 1313-13-9 T /L 28.7 Se IV 10102-18-8 T /L 0.5 U Se VI 13410-01-0 T /L 0.924 - Dissolved Oxygen DO N m /L 2.43 - 0.9 Temperature TEMP N Deg C 20.54 24.6 H PH N 6.5 8.5 02L SU 4.16 4.2 Turbidity, field TURB N NTU 6.4 18.2 Specific Conductivity field SC NPS/Cm 220 204.5 Oxidation Reduction Potential ORP N mV 479.9 366 GW Depth TOC GW DEPTH-TOC N ft I - 29.35 Notes: pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 16 of 16 Table 2-6 Background Groundwater Analytical Results - Rounds 1, 2, 3, and 4 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: BG-1D BG-1D BG-1D BG-1D BG-1D BG-IS BG-1S BG-1S BG-IS Round 1 Round 1 Round 2 Round 3 Round 4 Round 1 Round 2 Round 3 Round 4 7/11/2015 7/11/2015 9/18/2015 11/9/2015 12/9/2015 7/6/2015 9/17/2015 11/9/2015 12/9/2015 N FD N N N N N N FD BG-1D BG-1D DUP RV-BG-ID-NS-3Q15 RV-BG-ID-NS-4Q15-1 RV-BG-1D-NS-4Q15-2 BG-IS RV-BG-IS-NS-3Q15 RV-BG-IS-NS-4Q15-1 RV-BG-IS-FD-4Q15-2 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D p /L 740 730 500 440 480 100 U 100 U 100 U 100 U Aluminum 7429-90-5 T p /L 1400 6200 2700 540 510 J+ 1600 150 400 120 J+ Antimony 7440-36-0 D /L 3.9 4.2 1.3 0.86 1.1 0.23 J 0.5 U 0.24 J 0.5 U Antimony 7440-36-0 T 1 IMAC /L 3.3 4 1.7 0.8 1.1 0.43 J 0.5 U 0.3 J 0.5 U Arsenic 7440-38-2 D - p /L 2.1 1.8 0.4 J 0.65 0.79 0.5 U 0.5 U 0.11 J 0.5 U Arsenic 7440-38-2 T 10 02L pg/L 2 1.7 0.96 0.54 0.81 0.21 J 0.5 U 0.15 J 0.5 U Barium 7440-39-3 D /L 480 490 300 310 310 20 21 18 22 Barium 7440-39-3 T 700 02L /L 370 540 240 330 320 42 20 24 24 J+ Beryllium 7440-41-7 D - p /L 0.2U 0.2U 0.2U 0.2U 0.2U 0.2U 0.2U 0.2U 0.2LI Beryllium 7440-41-7 T 4 IMAC p /L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.076 J 0.2 U 0.2 U 0.2 U Boron 7440-42-8 D /L 49 J 43 J 50 U 50 U 50 U 50 U 50 U 50 U 50 U Boron 7440-42-8 T 700 02L /L 27 J 50 U 50 U 50 U 50 U 50 U 50 U 50 U 50 U Cadmium 7440-43-9 D - p /L 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U Cadmium 7440-43-9 T 2 02L p /L 0.08 U 0.031 J 0.08 U 0.08 U 0.08 U 0.034 J 0.08 U 0.08 U 0.08 U Calcium 7440-70-2 T /L 83300 107000 40800 56000 58900 1460 2170 760 1100 Chromium 7440-47-3 D /L 28.7 30.1 8.4 2 0.41 J 0.43 J+ 0.17 J+ 0.6 J+ 0.5 U Chromium 7440-47-3 T 10 02L p /L 32.3 51.9 13.7 3.7 2.5 5.2 0.79 J+ 0.74 J+ 0.22 J+ Cobalt 7440-48-4 D - p /L 1.3 1.4 0.79 0.71 0.78 1.9 1 0.88 0.72 Cobalt 7440-48-4 T 1 IMAC /L 1.3 2.9 1.8 0.75 0.86 3 1.3 0.93 0.78 Copper 7440-50-8 D /L 5.5 2.9 1.3 1.7 2 0.66 J 2.9 J+ 3.2 2.6 Copper 7440-50-8 T 1000 02L p /L 2.8 6.3 4.9 1.1 1.2 2.4 2.5 1.5 J+ 0.87 J Iron 7439-89-6 D - p /L 50 U 50 U 50 U 50 U 50 U 50 U 50 U 50 U 50 U Iron 7439-89-6 T 300 02L /L 1500 11700 3600 150 100 J+ 2200 190 520 150 J+ Lead 7439-92-1 D /L 0.61 0.16 0.22 0.27 0.32 0.1 U 0.17 J+ 0.22 0.19 Lead 7439-92-1 T 15 02L p /L 0.24 0.54 0.39 J+ 0.1 U 0.047 J 0.61 0.089 J 0.073 J 0.057 J Magnesium 7439-95-4 T - p /L 112 458 360 100 U 100 U 1330 1130 1090 1290 Manganese 7439-96-5 D /L 5 U 5 U 5 U 5 U 5 U 240 100 74 64 Manganese 7439-96-5 T 50 02L /L 27 210 72 2.8 J 5 UJ 300 96 95 72 J+ Mercury 7439-97-6 D - p /L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L p /L 0.12 J+ 0.2 UJ 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Methane 74-82-8 N /L 2.9 J+ 2.4 J+ 4.3 J+ 2.9 J 4.4 J+ 2.6 J+ 2.3 J+ 2.1 J+ 1.4 J+ Molybdenum 7439-98-7 D /L 10.1 10.2 6.9 10.1 12.2 0.5 U 0.27 J 0.5 U 0.5 U Molybdenum 7439-98-7 T p /L 9.4 8.4 13.2 9.8 12.4 0.2 J 0.22 J 0.5 U 0.5 U Nickel 7440-02-0 D - p /L 1.8 1.8 0.75 0.67 0.8 1.8 0.57 1.6 0.94 Nickel 7440-02-0 T 100 02L /L 1 6.7 15.6 2.9 0.86 1 4.4 0.92 1.7 J+ 0.99 Potassium 7440-09-7 T /L 130000 175000 96900 98000 87900 5000 U 5000 U 5000 U 5000 U Selenium 7782-49-2 D - p /L 2.7 2.8 0.77 0.55 0.61 0.5 U 0.5 U 0.5 U 0.5 U Selenium 7782-49-2 T 20 02L p /L 2.1 2.6 0.96 0.78 0.65 0.5 U 0.5 U 0.5 U 0.5 U Sodium 7440-23-5 T /L 75600 89100 54600 61300 76100 5000 U 5000 U 5000 U 5000 U Strontium 7440-24-6 D /L 4300 4400 2800 3100 2900 14 14 8.6 11 Strontium 7440-24-6 T p /L 3300 4500 2600 3100 3200 16 15 8.9 12 J+ Thallium 7440-28-0 D - p /L 0.1 U 0.026 J 0.1 U 0.1 U 0.1 U 0.016 J 0.021 J 0.026 J 0.018 J Thallium 7440-28-0 T 0.2 IMAC /L 0.1 U 0.023 J 0.1 U 0.1 U 0.1 U 0.032 J 0.017 J 0.029 J 0.02 J Vanadium 7440-62-2 D /L 20 19.9 17.6 11.2 9.5 1 U 1 U 1 U 1 U Vanadium 7440-62-2 T 0.3 IMAC p /L 22 24.2 21.7 10.6 9.9 5.9 0.63 J 0.3 J 0.42 J Zinc 7440-66-6 D - p /L 10 U 10 U 3.6 J 4.1 J 12 14 53 23 J+ 10 Zinc 7440-66-6 T 1000 02L /L 10 U 15 7.6 J 10 U 10 UJ 19 26 J+ 30 J+ 9.6 J+ Total Dissolved Solids TDS N 500000 02L /L 555000 86000 504000 250000 U 508000 25000 U 25000 U 25000 U 25000 U Total Organic Carbon TOC N - p /L 7300 7500 2900 5900 4600 1000 U 8700 1000 U 1000 U Total Suspended Solids TSS N p /L 237000 140000 124000 9400 4800 20600 9500 120000 9500 Alkalinity, CO3 ALK-CO3 N /L 401000 507000 256000 148000 288000 5000 U 5000 U 5000 U 5000 U Alkalinity, HCO3 ALK-HCO3 N /L 5000 U 5000 U 42400 5000 U 69800 10200 10100 J+ 6800 8600 Alkalinity, lab ALK-LAB N - p /L 412000 633000 298000 357000 357000 10200 10100 J+ 6800 8600 Chloride 16887-00-6 N 250000 02L p /L 6100 J- 5300 3500 - 3100 1900 1600 - 2000 Nitro en, NO2 plus NO3 NO2-NO3 N /L 30 23 20 20 U 20 U 40 99 70 99 Sulfate 14808-79-8 N 250000 02L /L 48400 J+ 49900 25800 29800 30000 J+ 580 J 1000 U 1000 U 1000 UJ Sulfide 18496-25-8 N - p /L 100 U 100 U 100 U 100 U 100 U 100 U 100 U 100 U 100 U Arsenic 7440-38-2 T 10 02L p /L - - - - - - - - - Chromium 7440-47-3 T 10 02L /L Iron 7439-89-6 T 300 02L /L Manganese 7439-96-5 D - p /L Manganese 7439-96-5 T 50 02L p /L As III 7784-46-5 T /L As V 10103-60-3 T /L Chromium VI 18540-29-9 T 0.07 DHHS p /L 1.5 0.025 J 0.03 U 0.018 J Fe II 1345-25-1 T - p /L - - Se IV 10102-18-8 T /L Page 1 of 10 Table 2-6 Background Groundwater Analytical Results - Rounds 1, 2, 3, and 4 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: BG-1D BG-1D BG-1D BG-1D BG-1D BG-1S BG-1S BG-1S BG-1S Round 1 Round 1 Round 2 Round 3 Round 4 Round 1 Round 2 Round 3 Round 4 7/11/2015 7/11/2015 9/18/2015 11/9/2015 12/9/2015 7/6/2015 9/17/2015 11/9/2015 12/9/2015 N FD N N N N N N FD BG-1D BG-1D DUP RV-BG-ID-NS-3Q15 RV-BG-ID-NS-4Q15-1 RV-BG-1D-NS-4Q15-2 BG-IS RV-BG-IS-NS-3Q15 RV-BG-1S-NS-4Q15-1 RV-BG-IS-FD-4Q15-2 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Se VI 13410-01-0 T N /L - - Uranium, Natural 7440-61-1 T p /L 0.112 J 0.331 Radium-226 13982-63-3 T Ci/L 0.652 J+ 1.01 J+ Radium-228 15262-20-1 T Ci/L 3.18 J+ 3 U Uranium-233 13968-55-3 T p /L 0.05 U 0.05 U Uranium-234 13966-29-5 T Ng/L 0.05 U 0.05 U Uranium-236 13982-70-2 T /L 0.05 U - - - 0.05 U - - Dissolved Oxygen DO N m /L - 0.1 3.1 0.2 5.45 0.1 5.9 Temperature TEMP N - - Deg C 16.6 15 15.3 21.2 23.4 14.9 pH PH N 6.5 8.5 02L SU 11.7 12.1 12 5.75 5.5 5.32 Turbidit , field TURB N - - NTU 1.3 5.1 2.9 13.71 8.8 16.23 S ecific Conductivity field SC N PS/CmI 1588 1748 1786 33.3 24.5 20.8 Oxidation Reduction Potential ORP N mV 1 -75 -465.3 199.2 288 15 258.4 GW Depth TOC GW_DEPTH-TOC N ft 1 34.45 41.05 37.5 35.28 35.02 Notes: pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 2 of 10 Table 2-6 Background Groundwater Analytical Results - Rounds 1, 2, 3, and 4 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: BG-11S BG-2BR BG-2BR BG-2BR BG-2BR BG-2BR BG-2D BG-2D BG-2D Round 4 Round 1 Round 1 Round 2 Round 3 Round 4 Round 1 Round 2 Round 3 12/9/2015 7/17/2015 7/17/2015 9/17/2015 11/9/2015 12/9/2015 7/11/2015 9/17/2015 11/9/2015 N FD N N N N N N N RV-BG-IS-NS-4Q15-2 BG-2BR DUP BG-2BR RV-BG-2BR-NS-3Q15 RV-BG-2BR-NS-4Q15-1 RV-BG-2BR-NS-4Q15- BG-2D RV-BG-2D-NS-3Q15 RV-BG-2D-NS-4Q15-1 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D p /L 100 U 100 U 100 U 100 U 100 U 100 U 480 890 260 Aluminum 7429-90-5 T p /L 100 UJ 140 J 580 J 140 78 J 100 UJ 530 910 300 J Antimony 7440-36-0 D /L 0.5 U 0.5 U 0.5 U 0.15 J 0.5 U 0.5 U 0.63 2.9 0.77 Antimony 7440-36-0 T 1 IMAC /L 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.72 3.9 0.74 J Arsenic 7440-38-2 D - p /L 0.5 U 0.16 J 0.12 J 0.35 J 0.37 J 0.49 J 0.6 1.1 1.1 Arsenic 7440-38-2 T 10 02L pg/L 0.5 U 0.19 J 0.28 J 0.36 J 0.49 J 0.55 0.66 1.4 1.1 Barium 7440-39-3 D /L 22 5.9 6 11 11 9.9 39 64 16 Barium 7440-39-3 T 700 02L /L 23 J+ 7.8 13 12 12 11 J+ 42 68 18 J Beryllium 7440-41-7 D - p /L 0.2U 0.2U 0.2U 0.2U 0.2U 0.2U 0.2U 0.2U 0.2U Beryllium 7440-41-7 T 4 IMAC p /L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Boron 7440-42-8 D /L 50 U 50 U 50 U 50 U 50 U 50 U 50 U 50 U 50 U Boron 7440-42-8 T 700 02L /L 50 U 50 U 50 U 50 U 50 U 50 U 50 UJ 50 U 50 U Cadmium 7440-43-9 D - p /L 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U Cadmium 7440-43-9 T 2 02L p /L 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.05 J 0.08 U 0.08 U Calcium 7440-70-2 T /L 1150 22300 24200 27000 27600 28200 57600 77600 31500 Chromium 7440-47-3 D /L 0.3 J 0.42 J+ 0.52 J+ 0.34 J 0.35 J 0.2 J 55.9 70.3 9.1 Chromium 7440-47-3 T 10 02L p /L 0.21 J+ 0.77 2.3 0.85 0.43 J 0.55 J+ 57.5 99.2 8.9 J Cobalt 7440-48-4 D - p /L 0.73 0.17 J 0.17 J 0.26 J 0.37 J 0.45 J 0.5 U 0.15 J 0.5 U Cobalt 7440-48-4 T 1 IMAC /L 0.68 0.36 J 0.82 0.35 J 0.64 0.74 0.5 U 0.25 J 0.5 U Copper 7440-50-8 D /L 0.81 J 0.63 J+ 0.84 J+ 4 2.1 0.34 J 0.54 J+ 2.3 J+ 1.5 J+ Copper 7440-50-8 T 1000 02L p /L 1.3 1.4 3.1 0.86 J 0.44 J 0.57 J 0.63 J 3 0.6 J+ Iron 7439-89-6 D - p /L 50 U 50 U 50 U 57 38 J 31 J 50 U 50 U 50 U Iron 7439-89-6 T 300 02L /L 1 64 J+ 230 J 760 J 310 150 120 J+ 50 U 57 50 U Lead 7439-92-1 D /L 0.1 U 0.1 U 0.048 J 0.75 0.24 0.05 J 0.1 U 0.21 J+ 0.2 Lead 7439-92-1 T 15 02L p /L 0.1 U 0.19 0.35 0.065 J 0.053 J 0.068 J 0.093 J 0.12 0.1 U Magnesium 7439-95-4 T - p /L 1310 2950 3100 3220 3110 3250 84.4 J 100 U 319 Manganese 7439-96-5 D /L 64 5 U 5 U 31 12 10 5 U 5 U 5 U Manganese 7439-96-5 T 50 02L /L 62 J+ 9.1 J 28 J 35 23 12 J+ 5 U 5 U 5 U Mercury 7439-97-6 D - p /L 0.2 U 0.2 U 0.14 J 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L p /L 0.2 U 0.2 U 0.79 J- 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Methane 74-82-8 N /L 2.2 J+ 5.3 J+ 12.6 J+ 2.3 J+ 2.5 J 2.2 J+ 1.8 J+ 3.1 J+ 3.6 J+ Molybdenum 7439-98-7 D /L 0.5 U 10.5 11 14.1 13 17 5 9.1 2.3 Molybdenum 7439-98-7 T p /L 0.5 U 11 12.8 14.4 13.8 19.5 5.2 12.2 2.3 J Nickel 7440-02-0 D - p /L 0.95 0.41 J 0.58 0.74 0.79 1 0.5 UJ 0.3 J 0.5 U Nickel 7440-02-0 T 100 02L /L 0.98 0.75 2.1 0.95 1 1.4 0.29 J 0.8 0.39 J+ Potassium 7440-09-7 T /L 5000 U 2880 J 5000 UJ 3810 J 3690 J 3180 J 4880 J 40200 6380 Selenium 7782-49-2 D - p /L 0.5 U 0.58 0.5 UJ 0.44 J 0.45 J 0.46 J 2.8 4.9 1.7 Selenium 7782-49-2 T 20 02L pg/L 0.5 U 0.54 0.6 0.45 J 0.36 J 0.46 J 2.9 6.8 1.4 Sodium 7440-23-5 T /L 5000 U 7710 7670 11700 12500 15300 29200 64700 28400 J Strontium 7440-24-6 D /L 11 120 120 160 160 150 300 540 180 Strontium 7440-24-6 T p /L 12 J+ 130 140 160 150 160 330 560 170 J Thallium 7440-28-0 D p /L 0.1 U 0.1 U 0.016 J 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U Thallium 7440-28-0 T 0.2 IMAC /L 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 UJ 0.024 J 0.1 U Vanadium 7440-62-2 D /L 1 U 2.5 2.7 1.6 2.2 2.3 29.2 29.6 21.8 Vanadium 7440-62-2 T 0.3 IMAC p /L 1 U 3 4.6 1.7 1.8 2.7 29.9 33.9 19.4 Zinc 7440-66-6 D - p /L 10 10 U 10 U 3.6 J+ 11 14 10 UJ 3.8 J+ 10 U Zinc 7440-66-6 T 1000 02L /L 9.8 J+ 6.2 J 12 16 J+ 4.5 J 6.2 J+ 10 U 6.8 J+ 10 U Total Dissolved Solids TDS N 500000 02L /L 25000 U 124000 118000 133000 130000 140000 261000 467000 160000 Total Organic Carbon TOC N - p /L 1000 U 1000 UJ 10100 J 950 J 1400 1500 1800 10900 2800 Total Suspended Solids TSS N p /L 7300 8800 19600 10500 4300 2500 U 2500 U 10400 3100 Alkalinity, CO3 ALK-CO3 N /L 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U 91300 64500 81500 Alkalinity, HCO3 ALK-HCO3 N /L 8800 77200 75400 82700 87500 94400 59000 5000 U 5000 U Alkalinity, lab ALK-LAB N p /L 8800 77200 75400 82700 87500 94400 150000 173000 J+ 109000 Chloride 16887-00-6 N 250000 02L p /L 2000 2100 2200 2900 - 3600 10000 12700 - Nitro en, NO2 plus NO3 NO2-NO3 N /L 100 520 500 340 120 67 1000 1100 1700 Sulfate 14808-79-8 N 250000 02L /L 1000 UJ 7800 8200 13900 15000 12500 J+ 31100 98900 22100 J Sulfide 18496-25-8 N - p /L 100 U 100 U 100 U 100 U 100 U 100 U 100 U 100 U 100 U Arsenic 7440-38-2 T 10 02L p /L - - - - - - - - - Chromium 7440-47-3 T 10 02L /L Iron 7439-89-6 T 300 02L /L Manganese 7439-96-5 D - p /L Manganese 7439-96-5 T 50 02L p /L As III 7784-46-5 T /L As V 10103-60-3 T /L - - - - Chromium VI 18540-29-9 T 0.07 DHHS p /L 0.018 J 0.03 U 0.03 U 9.2 J Fe II 1345-25-1 T p /L - - - - Se IV 10102-18-8 T /L Page 3 of 10 Table 2-6 Background Groundwater Analytical Results - Rounds 1, 2, 3, and 4 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: BG-1S BG-2BR BG-2BR BG-21BR BG-2BR BG-2BR BG-2D BG-2D BG-2D Round 4 Round 1 Round 1 Round 2 Round 3 Round 4 Round 1 Round 2 Round 3 12/9/2015 7/17/2015 7/17/2015 9/17/2015 11/9/2015 12/9/2015 7/11/2015 9/17/2015 11/9/2015 N FD N N N N N N N RV-BG-IS-NS-4Q15-2 BG-2BR DUP BG-2BR RV-BG-2BR-NS-3Q15 RV-BG-2BR-NS-4Q15-1 RV-BG-2BR-NS-4Q15- BG-2D RV-BG-2D-NS-3Q15 RV-BG-2D-NS-4Q15-1 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Se VI 13410-01-0 T N /L Uranium, Natural 7440-61-1 T p /L Radium-226 13982-63-3 T Ci/L Radium-228 15262-20-1 T Ci/L Uranium-233 13968-55-3 T p /L Uranium-234 13966-29-5 T ug/L Uranium-236 13982-70-2 T /L - - - - - - - Dissolved Oxygen DO N m /L 5 2.1 0.4 2.2 0.6 0.7 3.47 Temperature TEMP N - - Deg C 15.2 19.1 20.4 15.1 14.8 19.6 14 pH PH N 6.5 8.5 02L SU 5.7 8.2 7.68 8 7.8 11.7 11.23 Turbidity, field TURB N - - NTU 5.6 7.38 9.89 4.88 3.7 9.9 1.66 Specific Conductivity field SC NPS/ cm 30.4 180.2 207.9 235.2 219.7 1523 471.3 Oxidation Reduction Potential ORP N mV 250.4 180.8 -146.6 -114.1 -69.3 -81.4 -24.6 GW Depth TOC GW DEPTH-TOCI N ft 32.9 60.52 68.95 62.65 59.1 56.65 Notes: pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 4 of 10 Table 2-6 Background Groundwater Analytical Results - Rounds 1, 2, 3, and 4 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: BG-2D BG-2D BG-2S BG-2S BG-2S BG-2S BG-3D BG-3D BG-3D Round 3 Round 4 Round 1 Round 2 Round 3 Round 4 Round 1 Round 2 Round 3 11/9/2015 12/9/2015 7/10/2015 9/17/2015 11/9/2015 12/9/2015 7/6/2015 9/17/2015 11/9/2015 FD N N N N N N N N RV-BG-2D-FD-4Q15-1 RV-BG-2D-NS-4Q15-2 BG-2S RV-BG-2S-NS-3Q15 RV-BG-2S-NS-4Q15-1 RV-BG-2S-NS-4Q15-2 BG-3D RV-BG-3D-NS-3Q15 RV-BG-3D-NS-4Q15-1 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D p /L 240 430 100 U 100 U 100 U 100 U 100 U 100 U 100 U Aluminum 7429-90-5 T p /L 480 J 830 100 U 100 U 340 500 890 96 J 100 U Antimony 7440-36-0 D /L 0.81 3.3 0.25 J 0.5 U 0.21 J 0.16 J 0.5 U 0.5 U 0.5 U Antimony 7440-36-0 T 1 IMAC /L 1.11 3.7 0.33 J 0.5 U 0.58 0.28 J 0.16 J 0.5 U 0.5 U Arsenic 7440-38-2 D - p /L 1 1.4 0.14 J 0.5 U 0.19 J 0.5 U 0.38 J 0.13 J 0.21 J Arsenic 7440-38-2 T 10 02L pg/L 1.2 1.8 0.12 J 0.5 U 0.5 U 0.5 U 0.81 0.16 J 0.5 U Barium 7440-39-3 D /L 16 23 68 140 150 130 8.1 12 7 Barium 7440-39-3 T 700 02L /L 28 J 32 71 130 150 140 50 12 7.3 Beryllium 7440-41-7 D - p /L 0.2U 0.2U 0.2U 0.2LI 0.2U 0.2U 0.2U 0.2LI 0.2U Beryllium 7440-41-7 T 4 IMAC p /L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.53 0.2 U 0.2 U Boron 7440-42-8 D /L 50 U 50 U 50 U 50 U 50 U 50 U 50 U 50 U 50 U Boron 7440-42-8 T 700 02L /L 50 U 50 U 50 U 50 U 50 U 50 U 50 U 50 U 50 U Cadmium 7440-43-9 D - p /L 0.08 U 0.08 U 0.041 J 0.033 J 0.057 J 0.058 J 0.08 U 0.08 U 0.08 U Cadmium 7440-43-9 T 2 02L p /L 0.08 U 0.08 U 0.08 U 0.052 J 0.057 J 0.037 J 0.08 U 0.08 U 0.08 U Calcium 7440-70-2 T /L 39200 51400 11000 16900 16600 18800 9430 8540 7970 Chromium 7440-47-3 D /L 9.1 18 0.41 J 0.26 J+ 0.5 J+ 0.34 J 0.86 J+ 0.25 J+ 0.29 J+ Chromium 7440-47-3 T 10 02L p /L 15.4 J 51 0.83 0.95 J+ 1.3 J+ 4.2 0.97 J+ 0.54 J+ 0.27 J+ Cobalt 7440-48-4 D - p /L 0.5 U 0.5 U 0.69 0.29 J 0.32 J 0.31 J 0.14 J 0.42 J 0.5 U Cobalt 7440-48-4 T 1 IMAC /L 0.5 U 0.46 J 0.69 0.34 J 0.35 J 0.61 0.84 0.75 0.24 J Copper 7440-50-8 D /L 0.58 J+ 1.7 0.37 J 2.2 J+ 1.1 J+ 9.6 0.28 J+ 2.2 J+ 1.9 J+ Copper 7440-50-8 T 1000 02L p /L 1 J+ 2.9 1 U 1.5 0.74 J+ 0.75 J 2.2 0.33 J 1 U Iron 7439-89-6 D - p /L 50 U 50 U 50 U 50 U 50 U 50 U 50 U 50 U 50 U Iron 7439-89-6 T 300 02L /L 50 U 300 28 J 29 J 320 520 930 68 50 U Lead 7439-92-1 D /L 0.064 J 0.25 0.068 J 0.072 J+ 0.098 J 1 0.1 U 0.24 J+ 0.18 Lead 7439-92-1 T 15 02L p /L 0.05 J 0.3 0.1 U 0.1 U 0.078 J 0.33 5.1 0.23 0.1 U Magnesium 7439-95-4 T - p /L 222 333 2210 3350 3390 3750 2270 2060 1880 Manganese 7439-96-5 D /L 5 U 5 U 360 340 220 310 14 13 5 U Manganese 7439-96-5 T 50 02L /L 5 U 7.2 370 310 220 410 63 17 5 U Mercury 7439-97-6 D - p /L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L p /L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Methane 74-82-8 N /L 4 J+ 3.8 J+ 1.5 J+ 3.3 J+ 6.2 J+ 14.1 J+ 1.5 J+ 2.7 J+ 1.1 J+ Molybdenum 7439-98-7 D /L 2.6 4.8 0.25 J 0.73 0.5 U 0.11 J 3.6 1.6 0.86 Molybdenum 7439-98-7 T p /L 3.2 J 5.2 0.19 J 0.95 0.5 U 0.18 J 2.8 1.8 0.85 Nickel 7440-02-0 D - p /L 0.33 J 0.36 J 1.2 0.9 1.7 1.5 0.6 0.32 J 0.29 J Nickel 7440-02-0 T 100 02L /L 0.31 J+ 14 1.5 1.2 2.6 3.1 1.1 0.63 0.26 J+ Potassium 7440-09-7 T /L 11300 15900 J+ 5000 U 2770 J 2810 J 2720 J 5000 U 2630 J 5000 U Selenium 7782-49-2 D - p /L 1.7 2.6 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U Selenium 7782-49-2 T 20 02L pg/L 1.7 2.1 0.5 U 0.5 U 0.5 U 0.24 J 0.23 J 0.5 U 0.5 U Sodium 7440-23-5 T /L 36400 J 49700 7180 7890 8460 8460 16400 7500 7600 Strontium 7440-24-6 D /L 170 240 92 180 170 170 45 70 59 Strontium 7440-24-6 T p /L 270 J 280 94 160 150 180 100 66 57 Thallium 7440-28-0 D - p /L 0.1 U 0.1 U 0.031 J 0.037 J 0.033 J 0.03 J 0.1 U 0.1 U 0.1 U Thallium 7440-28-0 T 0.2 IMAC /L 0.1 U 0.1 U 0.033 J+ 0.035 J 0.035 J 0.035 J 0.1 U 0.1 U 0.1 U Vanadium 7440-62-2 D /L 21.5 27.5 1 U 1 U 1 U 1 U 3.1 2.4 2.2 Vanadium 7440-62-2 T 0.3 IMAC p /L 22.2 26.9 0.35 J 1 U 1 U 1.9 3.7 2.6 2.2 Zinc 7440-66-6 D - p /L 10 U 6.3 J 15 62 32 J+ 26 10 U 8 J+ 17 J+ Zinc 7440-66-6 T 1000 02L /L 6.5 J+ 18 J+ 8.9 J 49 46 42 J+ 5.1 J 16 J+ 7.9 J+ Total Dissolved Solids TDS N 500000 02L /L 210000 263000 87000 123000 114000 147000 231000 85000 80000 Total Organic Carbon TOC N - p /L 3400 10200 600 J 1000 U 1000 U 540 J 1000 U 1000 U 1000 U Total Suspended Solids TSS N p /L 2500 U 12100 7200 2500 U 24200 98300 218000 8600 2500 U Alkalinity, CO3 ALK-CO3 N /L 90500 52800 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U Alkalinity, HCO3 ALK-HCO3 N /L 5000 U 74200 22100 23200 J+ 16100 34200 43200 39900 J+ 33800 Alkalinity, lab ALK-LAB N - p /L 139000 127000 22100 23200 J+ 16100 34200 43200 39300 J+ 33800 Chloride 16887-00-6 N 250000 02L p /L - 10000 8900 11600 - 12200 2800 2900 - Nitro en, NO2 plus NO3 NO2-NO3 N /L 1600 1500 3900 10700 11000 9900 1600 1700 1700 Sulfate 14808-79-8 N 250000 02L /L 31100 J 42100 2900 1200 970 J 1700 1100 2400 1500 Sulfide 18496-25-8 N - p /L 100 U 100 UJ 100 U 100 U 100 U 100 U 100 U 100 U 100 U Arsenic 7440-38-2 T 10 02L p /L - - - - - - - - - Chromium 7440-47-3 T 10 02L /L Iron 7439-89-6 T 300 02L /L Manganese 7439-96-5 D - p /L Manganese 7439-96-5 T 50 02L p /L As III 7784-46-5 T /L As V 10103-60-3 T /L - - - - - Chromium VI 18540-29-9 T 0.07 DHHS p /L 13.1 J 17.9 0.27 0.095 0.04 Fe II 1345-25-1 T p /L - Se IV 10102-18-8 T I pg/L i - Page 5 of 10 Table 2-6 Background Groundwater Analytical Results - Rounds 1, 2, 3, and 4 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: BG-2D BG-2D BG-2S BG-2S BG-2S BG-2S BG-3D BG-3D BG-3D Round 3 Round 4 Round 1 Round 2 Round 3 Round 4 Round 1 Round 2 Round 3 11/9/2015 12/9/2015 7/10/2015 9/17/2015 11/9/2015 12/9/2015 7/6/2015 9/17/2015 11/9/2015 FD N N N N N N N N RV-BG-2D-FD-4Q15-1 RV-BG-2D-NS-4Q15-2 BG-2S RV-BG-2S-NS-3Q15 RV-BG-2S-NS-4Q15-1 RV-BG-2S-NS-4Q15-2 BG-3D RV-BG-3D-NS-3Q15 RV-BG-3D-NS-4Q15-1 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Se VI 13410-01-0 T N /L Uranium, Natural 7440-61-1 T p /L Radium-226 13982-63-3 T Ci/L Radium-228 15262-20-1 T Ci/L Uranium-233 13968-55-3 T p /L Uranium-234 13966-29-5 T ug/L Uranium-236 13982-70-2 T /L - - - - - - - Dissolved Oxygen DO N m /L 1.73 3.9 3.01 0.89 4.2 3.9 13.9 Temperature TEMP N - Deg C 15.7 17.4 14.5 12.4 18.4 18.5 13.9 pH PH N 6.5 8.5 02L SU 11.57 5.8 5.9 6.06 7.1 6.7 6.6 Turbidity, field TURB N - - NTU 15.9 5 9.94 8.53 123.6 7.4 4.99 Specific Conductivity field SC N S/cm 525 178.4 189.5 141.8 115.7 100.6 96.7 Oxidation Reduction Potential ORP N mV -34.6 3.7 196.9 175.2 1 179.1 -16.7 151 GW Depth TOC GW DEPTH-TOCI N ft 65.46 57.36 56.2 1 - 30.95 Notes: pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 6 of 10 Table 2-6 Background Groundwater Analytical Results - Rounds 1, 2, 3, and 4 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: BG-3D BG-3S BG-3S BG-3S BG-3S MW-7BR MW-7BR MW-7BR MW-7D Round 4 Round 1 Round 2 Round 3 Round 4 Round 1 Round 2 Round 4 Round 2 12/9/2015 6/30/2015 9/17/2015 11/9/2015 12/9/2015 7/10/2015 9/15/2015 12/9/2015 9/16/2015 N N N N N N N N FD RV-BG-3D-NS-4Q15-2 BG-3S RV-BG-3S-NS-3Q15 RV-BG-3S-NS-4015-1 RV-BG-3S-NS-4Q15-2 MW-7BR RV-MW-7BR-NS-3Q15 RV-MW-7BR-NS-4Q15-2 RV-MW-7D-FD-3Q15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D p /L 100 U 100 U 100 U 100 U 100 U 690 720 81 J 100 U Aluminum 7429-90-5 T p /L 100 U 100 U 100 U 110 83 J+ 760 680 330 100 U Antimony 7440-36-0 D /L 0.5 U 1.4 J+ 0.5 U 0.5 U 0.5 U 0.22 J 0.5 U 3.6 0.5 U Antimony 7440-36-0 T 1 IMAC /L 0.5 U 1.3 J+ 0.5 U 0.5 U 0.5 U 0.86 1.6 2.5 0.5 U Arsenic 7440-38-2 D - p /L 0.13 J 0.5 U 0.13 J 0.37 J 0.29 J 0.24 J 0.24 J 0.17 J 0.5 U Arsenic 7440-38-2 T 10 02L pg/L 0.5 U 0.5 U 0.17 J 0.58 0.35 J 0.23 J 0.28 J 0.5 U 0.5 U Barium 7440-39-3 D /L 9.1 33 47 7.1 45 290 420 370 26 Barium 7440-39-3 T 700 02L /L 8.4 33 45 49 48 J+ 340 550 400 28 Beryllium 7440-41-7 D - p /L 0.2U 0.2U 0.2U 0.2U 0.2U 0.2U 0.2U 0.2U 0.2U Beryllium 7440-41-7 T 4 IMAC p /L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Boron 7440-42-8 D /L 50 U 50 U 50 U 50 U 50 U 50 U 50 U 50 U 50 U Boron 7440-42-8 T 700 02L /L 1 50 U 50 U 50 U 50 U 50 U 50 U 50 U 50 U 50 U Cadmium 7440-43-9 D - p /L 0.08 U 0.032 J 0.08 U 0.08 U 0.034 J 0.08 U 0.08 U 0.08 U 0.028 J Cadmium 7440-43-9 T 2 02L p /L 0.08 U 0.031 J 0.041 J 0.08 U 0.025 J 0.08 U 0.08 U 0.08 U 0.08 U Calcium 7440-70-2 T /L 8200 6140 9080 10800 9970 537000 587000 491000 2500 Chromium 7440-47-3 D /L 0.19 J 0.33 J+ 0.64 J+ 0.52 J+ 0.19 J 23.3 22.1 22.3 0.8 Chromium 7440-47-3 T 10 02L p /L 0.23 J 0.25 J+ 0.64 J+ 0.74 J+ 0.29 J+ 24.7 20.9 18.6 0.71 J+ Cobalt 7440-48-4 D - p /L 0.53 0.54 0.78 1.1 0.77 0.5 U 0.5 U 0.5 U 0.5 U Cobalt 7440-48-4 T 1 IMAC /L 1.2 0.54 0.75 1.5 0.91 0.5 U 0.5 U 0.5 U 0.5 U Copper 7440-50-8 D /L 1.5 1 UJ 3.4 J+ 0.75 J+ 7.4 1.6 2 7.2 0.41 J Copper 7440-50-8 T 1000 02L p /L 1 U 1 UJ 1 U 0.28 J+ 0.32 J 1.5 1.8 J+ 1.4 0.47 J+ Iron 7439-89-6 D - p /L 50 U 50 U 240 50 U 810 50 U 50 U 50 U 50 U Iron 7439-89-6 T 300 02L /L 50 U 50 UJ 220 1800 920 J+ 50 U 53 50 U 50 U Lead 7439-92-1 D /L 0.14 0.1 UJ 0.67 J+ 0.1 U 1.1 0.22 0.23 1.4 0.1 U Lead 7439-92-1 T 15 02L p /L 0.06 J 0.1 U 0.1 U 0.056 J 0.1 U 0.21 0.27 0.21 0.1 U Magnesium 7439-95-4 T - p /L 2010 775 1110 1200 1180 100 U 100 U 100 U 886 Manganese 7439-96-5 D /L 2.9 J 240 520 5 U 580 5 U 5 U 5 U 5 U Manganese 7439-96-5 T 50 02L /L 9.9 240 560 1300 800 5 U 5 U 5 U 6.8 Mercury 7439-97-6 D - p /L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L p /L 0.2 U 0.073 J 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Methane 74-82-8 N /L 1.2 J+ 1.4 J+ 10 U 5.2 J+ 15.5 J+ 1.6 J+ 2 J+ 2.2 J+ 0.95 J+ Molybdenum 7439-98-7 D /L 1.2 0.16 J 0.17 J 0.25 J 0.19 J 12.4 11 11.2 0.5 U Molybdenum 7439-98-7 T p /L 0.78 0.14 J 0.16 J 0.28 J 0.22 J 13.3 8.5 9.7 0.5 U Nickel 7440-02-0 D - p /L 0.35 J 0.69 1.2 1.3 1.1 0.22 J 0.58 0.43 J 0.19 J Nickel 7440-02-0 T 100 02L /L 0.31 J 0.63 J+ 1.1 1.2 J+ 1.1 0.29 J 0.84 0.19 J 0.5 U Potassium 7440-09-7 T /L 5000 U 5000 U 5000 U 5000 U 5000 U 17800 19600 23700 5000 U Selenium 7782-49-2 D - p /L 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.48 J 0.47 J 0.42 J 0.5 U Selenium 7782-49-2 T 20 02L pg/L 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.51 0.38 J 0.35 J 0.5 U Sodium 7440-23-5 T /L 7930 J+ 7260 7040 7780 8080 25300 21100 40300 3120 J Strontium 7440-24-6 D /L 62 67 94 60 88 1400 2400 1700 44 Strontium 7440-24-6 T p /L 62 68 93 98 90 J+ 1600 3200 1900 44 Thallium 7440-28-0 D p /L 0.1 U 0.1 U 0.1 U 0.017 J 0.021 J 0.071 J 0.046 J 0.043 J 0.026 J Thallium 7440-28-0 T 0.2 IMAC /L 0.1 U 0.1 U 0.016 J 0.019 J 0.1 U 0.064 J+ 0.039 J 0.037 J 0.1 U Vanadium 7440-62-2 D /L 2.6 0.7 J+ 0.33 J 1 U 1 U 2.1 0.95 J 1.2 1 U Vanadium 7440-62-2 T 0.3 IMAC p /L 2.4 0.75 J+ 1 U 0.29 J 0.29 J 2.1 1.2 0.911 1 U Zinc 7440-66-6 D - p /L 14 10 UJ 2.8 J+ 17 J+ 13 10 U 10 U 4.5 J+ 4.8 J Zinc 7440-66-6 T 1000 02L /L 4.8 J 10 UJ 5.6 J+ 11 J+ 7.7 J+ 10 U 5.2 J+ 12 3.5 J Total Dissolved Solids TDS N 500000 02L /L 92000 57000 66000 25000 U 68000 1180000 1590000 1340000 38000 Total Organic Carbon TOC N - p /L 6900 1000 U 1000 U 690 J 680 J 1300 770 J 780 J 11800 Total Suspended Solids TSS N p /L 2600 U 2500 U 5000 U 5100 U 5500 7000 14500 5000 2500 U Alkalinity, CO3 ALK-CO3 N /L 5000 U 5000 U 5000 U 5000 U 5000 U 657000 103000 479000 5000 U Alkalinity, HCO3 ALK-HCO3 N /L 34000 28900 38500 J+ 50300 46500 5000 U 5000 U 5000 U 16000 Alkalinity, lab ALK-LAB N - p /L 34000 28900 38500 J+ 50300 46500 1080000 1850000 1190000 16000 Chloride 16887-00-6 N 250000 02L p /L 3200 4600 3300 - 3400 4900 4400 4300 1100 J+ Nitrogen, NO2 plus NO3 NO2-NO3 N /L 1800 20 U 20 U 20 U 20 U 191 16 J 27 21 Sulfate 14808-79-8 N 250000 02L /L 1500 2400 1500 1100 2200 J+ 7200 14300 1000 U 1000 U Sulfide 18496-25-8 N - p /L 100 U 100 U 100 U 100 U 100 U 100 U 100 U 100 U 100 U Arsenic 7440-38-2 T 10 02L p /L - - - - - - - - 0.5 U Chromium 7440-47-3 T 10 02L /L 1.44 J+ Iron 7439-89-6 T 300 02L /L 100 UJ Manganese 7439-96-5 D - p /L 1.59 J Manganese 7439-96-5 T 50 02L p /L 2.29 J As III 7784-46-5 T /L 0.5 UJ As V 10103-60-3 T /L 0.5 U Chromium VI 18540-29-9 T 0.07 DHHS p /L 0.053 0.03 U 0.03 U 22.6 0.58 J Fe II 1345-25-1 T p /L - - 30 UJ Se IV 10102-18-8 T /L 2 U Page 7 of 10 Table 2-6 Background Groundwater Analytical Results - Rounds 1, 2, 3, and 4 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: BG-3D BG-3S BG-3S BG-3S BG-3S MW-7BR MW-7BR MW-7BR MW-7D Round 4 Round 1 Round 2 Round 3 Round 4 Round 1 Round 2 Round 4 Round 2 12/9/2015 6/30/2015 9/17/2015 11/9/2015 12/9/2015 7/10/2015 9/15/2015 12/9/2015 9/16/2015 N N N N N N N N FD RV-BG-3D-NS-4Q15-2 BG-3S RV-BG-3S-NS-3Q15 RV-BG-3S-NS-4015-1 RV-BG-3S-NS-4Q15-2 MW-7BR RV-MW-7BR-NS-3Q15 RV-MW-7BR-NS-4Q15-2 RV-MW-7D-FD-3Q15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Se VI 13410-01-0 T N /L 2 U Uranium, Natural 7440-61-1 T p /L Radium-226 13982-63-3 T Ci/L Radium-228 15262-20-1 T Ci/L Uranium-233 13968-55-3 T p /L Uranium-234 13966-29-5 T ug/L Uranium-236 13982-70-2 T /L - - - - - - - Dissolved Oxygen DO N m /L 4.1 6.4 0.7 1.3 2.6 3.85 1.68 Temperature TEMP N - - Deg C 15.2 18.19 19.4 13.3 15.1 18.5 15.5 pH PH N 6.5 8.5 02L SU 7.2 6.15 6.2 6.3 6.1 12.26 12.57 Turbidity, field TURB N - - NTU 1 1.93 1.2 9.23 5.1 6.4 4.31 Specific Conductivity field SC N PS/cmI 99.9 1 79 1 94.2 1 109 1 68.9 1 5381 5577 Oxidation Reduction Potential ORP N mV 180 161.3 1 -53.1 15.3 68.7 -206 -215.3 GW Depth TOC GW_DEPTH-TOC N ft 28.45 1 30.55 27.9 56.72 Notes: pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 8 of 10 Table 2-6 Background Groundwater Analytical Results - Rounds 1, 2, 3, and 4 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: MW-7D MW-7D MW-7SR MW-7SR Round 2 Round 4 Round 2 Round 4 9/16/2015 12/9/2015 9/16/2015 12/10/2015 N N N N RV-MW-7D-NS-3Q15 RV-MW-7D-NS-4Q15 RV-MW-7SR-NS-3Q15 RV-MW-7S-NS-4Q15-2 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D p /L 100 U 100 U 100 U 100 U Aluminum 7429-90-5 T p /L 100 U 100 U 3200 140 Antimony 7440-36-0 D /L 0.5 U 0.5 U 0.5 U 0.5 U Antimony 7440-36-0 T 1 IMAC /L 0.5 U 0.5 U 0.5 U 0.5 U Arsenic 7440-38-2 D - p /L 0.5 U 0.5 U 0.5 U 0.5 U Arsenic 7440-38-2 T 10 02L pg/L 0.5 U 0.5 U 0.38 J 0.5 U Barium 7440-39-3 D /L 26 27 12 14 Barium 7440-39-3 T 700 02L /L 26 28 30 15 Beryllium 7440-41-7 D - p /L 0.2 U 0.2 U 0.2 U 0.2 U Beryllium 7440-41-7 T 4 IMAC p /L 0.2 U 0.2 U 0.07 J 0.2 U Boron 7440-42-8 D /L 50 U 50 U 50 U 50 U Boron 7440-42-8 T 700 02L /L 1 50 U 50 U 50 U 50 U Cadmium 7440-43-9 D - p /L 0.027 J 0.08 U 0.08 U 0.028 J Cadmium 7440-43-9 T 2 02L p /L 0.08 U 0.08 U 0.08 U 0.08 U Calcium 7440-70-2 T /L 2550 3060 400 344 Chromium 7440-47-3 D /L 0.78 1.1 0.28 J 0.53 Chromium 7440-47-3 T 10 02L p /L 0.75 J+ 0.87 J+ 3.1 0.88 J+ Cobalt 7440-48-4 D - p /L 0.5 U 0.5 U 1.8 0.4 J Cobalt 7440-48-4 T 1 IMAC /L 0.5 U 0.5 U 2.2 1.4 Copper 7440-50-8 D /L 0.39 J 9.5 1 U 0.57 J Copper 7440-50-8 T 1000 02L p /L 0.44 J+ 0.42 J 2.3 0.34 J Iron 7439-89-6 D - p /L 50 U 50 U 1400 34 J Iron 7439-89-6 T 300 02L /L 50 U 50 U 6500 420 Lead 7439-92-1 D /L 0.1 U 1.1 0.1 U 0.048 J Lead 7439-92-1 T 15 02L p /L 0.1 U 0.1 U 1.4 0.11 Magnesium 7439-95-4 T - p /L 871 1010 929 985 Manganese 7439-96-5 D /L 5 U 5 U 62 36 Manganese 7439-96-5 T 50 02L /L 5 U 5 U 110 81 Mercury 7439-97-6 D - p /L 0.2 U 0.2 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L p /L 0.2 U 0.2 U 0.2 U 0.2 U Methane 74-82-8 N /L 1.8 J+ 1.3 J+ 11.1 J+ 7.6 J+ Molybdenum 7439-98-7 D /L 0.5 U 0.5 U 0.1 J 0.5 U Molybdenum 7439-98-7 T p /L 0.5 U 0.5 U 0.16 J 0.5 U Nickel 7440-02-0 D - p /L 0.23 J 0.42 J 1.3 1 Nickel 7440-02-0 T 100 02L /L 0.22 J 0.18 J 1.8 1.3 Potassium 7440-09-7 T /L 5000 U 5000 U 5000 U 5000 U Selenium 7782-49-2 D - p /L 0.5 U 0.5 U 0.5 U 0.5 U Selenium 7782-49-2 T 20 02L pg/L 0.5 U 0.5 U 0.27 J 0.5 U Sodium 7440-23-5 T /L 3120 J 3680 J 5000 U 5000 U Strontium 7440-24-6 D /L 43 45 4.1 J 3 J Strontium 7440-24-6 T p /L 41 47 5.8 2.5 J Thallium 7440-28-0 D - p /L 0.1 U 0.016 J 0.1 U 0.019 J Thallium 7440-28-0 T 0.2 IMAC /L 0.1 U 0.021 J 0.024 J+ 0.1 U Vanadium 7440-62-2 D /L 1 U 1 U 0.53 J 1 U Vanadium 7440-62-2 T 0.3 IMAC p /L 1 U 1 U 7.4 0.57 J Zinc 7440-66-6 D - p /L 4.3 J 7.9 J 5.2 J 5.3 J Zinc 7440-66-6 T 1000 02L /L 3.3 J 9.6 J 11 J+ 3.7 J Total Dissolved Solids TDS N 500000 02L /L 49000 43000 25000 U 25000 U Total Organic Carbon TOC N - p /L 1000 U 1000 U 530 J 1000 U Total Suspended Solids TSS N p /L 2500 U 5000 U 214000 12100 Alkalinity, CO3 ALK-CO3 N /L 5000 U 5000 U 5000 U 5000 U Alkalinity, HCO3 ALK-HCO3 N /L 15600 18000 7200 J+ 5100 Alkalinity, lab ALK-LAB N - p /L 15600 18000 7200 J+ 5100 Chloride 16887-00-6 N 250000 02L p /L 1100 J+ 1400 2000 2100 Nitrogen, NO2 plus NO3 NO2-NO3 N /L 191 25 33 59 J+ Sulfate 14808-79-8 N 250000 02L /L 1000 U 1000 U 1000 U 1000 U Sulfide 18496-25-8 N - p /L 100 U 100 U 100 U 100 U Arsenic 7440-38-2 T 10 02L p /L 0.5 U - 0.5 U - Chromium 7440-47-3 T 10 02L /L 2.37 J+ 2.43 J+ Iron 7439-89-6 T 300 02L /L 22.1 J+ 2360 J Manganese 7439-96-5 D - p /L 1.79 J 55.9 J Manganese 7439-96-5 T 50 02L p /L 1.99 J 100 J As III 7784-46-5 T - /L 0.5 UJ 0.241 J+ As V 10103-60-3 T /L 0.5 U - 0.5 U - Chromium VI 18540-29-9 T 0.07 DHHS p /L 0.58 J 0.87 0.02 UJ 0.25 Fe II 1345-25-1 T - p /L 30 UJ 1360 J Se IV 10102-18-8 T /L 2 U 2 U Page 9 of 10 Table 2-6 Background Groundwater Analytical Results - Rounds 1, 2, 3, and 4 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: MW-7D MW-7D MW-7SR MW-7SR Round 2 Round 4 Round 2 Round 4 9/16/2015 12/9/2015 9/16/2015 12/10/2015 N N N N RV-MW-7D-NS-3Q15 RV-MW-7D-NS-4Q15 RV-MW-7SR-NS-3Q15 RV-MW-7S-NS-4Q15-2 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Se VI 13410-01-0 T p /L 2 U 2 U Uranium, Natural 7440-61-1 T p /L Radium-226 13982-63-3 T Ci/L Radium-228 15262-20-1 T Ci/L Uranium-233 13968-55-3 T p /L Uranium-234 13966-29-5 T ug/L Uranium-236 13982-70-2 T /L - - Dissolved Oxygen DO N m /L 6.6 4.8 Temperature TEMP N - - Deg C 16.9 19.8 pH PH N 6.5 8.5 02L SU 5.67 5.36 Turbidity, field TURB N - - NTU 1.3 427 Specific Conductivity field SC NPS/cm 38 26 Oxidation Reduction Potential ORP N mV 221 132 GW Depth TOC GW_DEPTH-TOC N ft 56.1 58.75 Notes: pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal INS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 10 of 10 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: GWA-10BRU GWA-10D GWA-10S GWA-10S GWA-1BRU GWA-1D GWA-1S GWA-1S Round 2 Round 1 Round 1 Round 2 Round 2 Round 1 Round 1 Round 2 9/16/2015 7/3/2015 7/2/2015 9/16/2015 9/16/2015 7/2/2015 7/2/2015 9/16/2015 N N N N N N N N RV-GWA-10BRU-NS-3Q15 GWA-10D GWA-10S RV-GWA-10S-NS-3Q15 RV-GWA-1BRU-NS-3Q15 GWA-1D GWA-1S RV-GWA-IS-NS-3Q15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D p /L 520 270 100 U 100 U 100 U 680 100 U 64 J Aluminum 7429-90-5 T pg/L 2400 370 67 J 54 J 100 1500 1800 1400 Antimony 7440-36-0 D p /L 2 0.5 U 0.5 U 0.5 U 0.5 U 2.6 0.22 J 0.5 U Antimony 7440-36-0 T 1 IMAC pg/L 8.6 1.1 0.5 U 0.5 U 0.5 U 3.2 0.28 J 0.5 U Arsenic 7440-38-2 D - p /L 0.93 0.36 J 0.5 U 0.5 U 0.36 J 0.82 0.5 U 0.5 U Arsenic 7440-38-2 T 10 02L pg/L 0.93 0.29 J 0.5 U 0.16 J 0.33 J 0.93 0.5 U 0.5 U Barium 7440-39-3 D - p /L 59 45 28 25 4.2 J 12 33 35 Barium 7440-39-3 T 700 02L pg/L 91 58 29 24 4.5 J 18 60 55 Ter Ilium 7440-41-7 D - pg/L 0.2 U 0.2 U 0.094 J 0.079 J 0.2 U 0.2 U 0.2 U 0.2 U Beryllium 7440-41-7 T 4 IMAC pg/L 0.2 U 0.2 U 0.11 J 0.099 J 0.2 U 0.2 U 0.2 U 0.2 U Boron 7440-42-8 D - pg/L 140 110 170 170 50 U 31 J 50 U 48 J Boron 7440-42-8 T 700 02L pg/L 90 140 170 160 50 U 33 J 50 UJ 43 J Cadmium 7440-43-9 D - p /L 0.08 U 0.08 U 0.038 J 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U Cadmium 7440-43-9 T 2 02L p /L 0.08 U 0.08 U 0.032 J 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U Calcium 7440-70-2 T - p /L 56000 25600 5040 5020 19300 47400 4160 6270 Chromium 7440-47-3 D /L 0.71 7.9 1 J 0.41 J 0.18 J 2.9 J 1.1 J 1.9 Chromium 7440-47-3 T 10 02L p /L 2.5 J+ 6.1 3.5 J 0.21 J+ 0.71 J+ 6.1 11.6 3.2 Cobalt 7440-48-4 D - pg/L 0.5 U 0.5 U 10.3 11 0.5 U 0.5 U 0.23 J 0.37 J Cobalt 7440-48-4 T 1 IMAC p /L 0.44 J 0.19 J 10 11 0.5 U 0.55 2.1 1.3 Copper 7440-50-8 D - pg/L 0.98 J 1.2 J+ 1.3 J+ 2.7 0.49 J 0.74 J+ 1.8 J+ 2.2 Copper 7440-50-8 T 1000 02L p /L 5.6 3 1.5 J+ 0.34 J 6.5 4.1 9.8 7.4 Iron 7439-89-6 D - pg/L 50 U 50 U 32 J 890 50 U 50 U 50 U 58 Iron 7439-89-6 T 300 02L p /L 470 170 87 1200 72 720 1800 1600 Lead 7439-92-1 D - pg/L 0.091 J 0.1 U 0.1 U 0.77 0.1 U 0.1 U 0.12 0.1 U Lead 7439-92-1 T 15 02L pg/L 0.5 0.42 0.1 UJ 0.1 U 0.1 U 0.13 J+ 0.21 J+ 0.16 Magnesium 7439-95-4 T - pg/L 3110 5810 5840 5920 3590 606 3390 3980 Manganese 7439-96-5 D - p /L 5 U 5 U 240 420 11 5 U 30 16 Manganese 7439-96-5 T 50 02L pg/L 17 10 250 410 14 28 110 67 Mercury 7439-97-6 D - p /L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L pg/L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Methane 74-82-8 N - p /L 3 J+ 2 J+ 1.2 J+ 2 J+ 2.2 J+ 10 UJ 2 J+ 1.9 J+ Molybdenum 7439-98-7 D pg/L 2.8 6 0.5 U 0.5 U 7.7 9.5 0.24 J 0.18 J Molybdenum 7439-98-7 T p /L 4 4.1 0.5 U 0.5 U 8.5 10.5 0.43 J 0.17 J Nickel 7440-02-0 D - pg/L 0.5 U 0.25 J+ 1.9 J+ 1.3 0.5 U 0.18 J+ 1 J+ 0.72 Nickel 7440-02-0 T 100 02L p /L 1.4 0.81 3.3 1.1 0.21 J 1.6 6.3 1.5 Potassium 7440-09-7 T - pg/L 155000 64400 5000 U 5000 U 3300 J 16600 5000 U 5000 U Selenium 7782-49-2 D - p /L 0.21 J 0.6 0.5 U 0.5 U 0.5 U 0.49 J 0.5 U 0.5 U Selenium 7782-49-2 T 20 02L pg/L 0.36 J 0.41 J 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U Sodium 7440-23-5 T - p /L 58800 28300 4620J 5190 8200 15300 6740 3640J Strontium 7440-24-6 D pg/L 630 490 64 62 90 330 35 49 Strontium 7440-24-6 T pg/L 1000 520 67 57 83 350 40 48 Thallium 7440-28-0 D - pg/L 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U Thallium 7440-28-0 T 0.2 IMAC p /L 0.018 J 0.1 U 0.1 U 0.022 J 0.1 U 0.1 U 0.1 U 0.1 U Vanadium 7440-62-2 D - pg/L 10.2 7.7 0.39 J 1 U 2 16.9 0.86 J 2.3 Vanadium 7440-62-2 T 0.3 IMAC p /L 10.9 6.8 0.62 J 1 U 1.9 21 7.9 6 Zinc 7440-66-6 D - pg/L 10 U 10 U 13 14 5.3 J 10 U 29 16 Zinc 7440-66-6 T 1000 02L p /L 8.7 J 7.7 J 8.6 J 6.1 J 5.2 J 4 J+ 27 J+ 21 Total Dissolved Solids TDS N 500000 02L pg/L 310000 185000 109000 84000 108000 232000 78000 58000 Total Organic Carbon TOC N - p /L 7800 3000 1000 U 1000 U 9200 740 J 1000 U 1000 U Total Suspended Solids TSS N pg/L 42500 38800 2500 U 2500 U 6500 62700 80800 71800 Alkalinity, CO3 ALK-0O3 N p /L 56200 36600 J 5000 U 5000 U 12400 35000 5000 U 5000 U Alkalinity, HCO3 ALK-HCO3 N pg/L 5000 U 96100 J 4300 J 8700 J+ 50000 148000 25000 37400 Alkalinity, lab ALK-LAB N - p /L 271000 133000 J 4300 J 8700 J+ 62000 183000 25000 37400 Chloride 16887-00-6 N 250000 02L pg/L 5600 6400 5700 6000 2500 3200 5200 5700 Fluoride 16984-48-8 N - p /L - - - - - - - - Nitrogen, NO2 plus NO3 NO2-NO3 N - pg/L 20 U 18 J 20 UJ 10 J 17 J 190 120 160 Sulfate 14808-79-8 N 250000 02L pg/L 24800 25900 31000 32200 11500 J+ 8700 1000 U 470 J+ Sulfide 18496-25-8 N - pg/L 100 U 100 U 100 U 100 U 100 U 100 U 100 U 100 U Arsenic 7440-38-2 T 10 02L p /L - - - - - - - - Chromium 7440-47-3 T 10 02L pg/L Page 1 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: GWA-106RU GWA-10D GWA-10S GWA-10S GWA-1BRU GWA-1D GWAAS GWAAS Round 2 Round 1 Round 1 Round 2 Round 2 Round 1 Round 1 Round 2 9/16/2015 7/3/2015 7/2/2015 9/16/2015 9/16/2015 7/2/2015 7/2/2015 9/16/2015 N N N N N N N N RV-GWA-10BRU-NS-3015 GWA-10D GWA-10S RV-GWA-10S-NS-3Q15 RV-GWA-113RU-NS-3Q15 GWA-1D GWAAS RV-GWA-1S-NS-3Q15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Iron 7439-89-6 T 300 02L N /L Manganese 7439-96-5 D /L Manganese 7439-96-5 T 50 02L I pg/L As III 7784-46-5 T /L As V 10103-60-3 T - N /L Chromium VI 18540-29-9 D 0.07 DHHS /L Chromium VI 18540-29-9 T 0.07 DHHS /L Fe II 1345-25-1 T /L Fe III 1309-37-1 T /L Mn II 1344-43-0 T /L Mn IV 1313-13-9 T /L Se IV 10102-18-8 T /L Se VI 13410-01-0 T /L Uranium, Natural 7440-61-1 T /L Radium-226 13982-63-3 T Ci/L Radium-228 15262-20-1 T Ci/L Uranium-233 13968-55-3 T /L Uranium-234 13966-29-5 T /L Uranium-236 13982-70-2 T /L Dissolved Oxygen DO N m /L 1 1.89 136 0.6 0.4 0.33 3.03 2.6 Temperature TEMP N - - Deg C 18.3 19.7 20.7 16.5 18.9 18.8 20.8 20.1 H PH N 6.5 8.5 02L SU 11.7 10.92 5.17 5.4 8.9 11.22 6.07 6.1 Turbidity, field TURB N - - NTU 4.4 7.75 4.4 6.7 7.4 21.25 47.36 70.4 ,Specific Conductivity field SC N S/cm 1494 519.3 85.9 110.4 150.3 504 78 75 Oxidation Reduction Potential ORP N mV -98.8 183.8 311 -53.4 -73.3 -169.4 237.5 -5.2 GW Depth TOC GW DEPTH-TOCI N I ft 14.4 15.43 37.54 37.05 Notes pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 2 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: GWA-20BR GWA-20BR GWA-20D GWA-20D GWA-20S GWA-20S GWA-21BR GWA-21BR Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 Round 1 7/27/2015 9/19/2015 7/16/2015 9/19/2015 7/11/2015 9/16/2015 8/27/2015 8/27/2015 N N N N N N N N GWA-20BR RV-GWA-20BR-NS-3Q15 GWA-20D RV-GWA-20D-NS-3Q15 GWA-20S RV-GWA-20S-NS-3Q15 GWA-21BR 1-G GWA-21BR (2-BP) Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D p /L 57 66 J 120 100 U 100 U 100 U 100 U 100 U Aluminum 7429-90-5 T pg/L 217 94 J 650 540 4200 280 J+ 120 1600 Antimony 7440-36-0 D p /L 1 U 24.6 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U Antimony 7440-36-0 T 1 IMAC pg/L 1 U 25.3 0.5 U 0.5 U 0.22 J 0.5 U 0.5 U 0.5 U Arsenic 7440-38-2 D - p /L 1 U 0.12 J 0.27 J+ 0.54 0.5 U 0.5 U 0.24 J 0.31 J Arsenic 7440-38-2 T 10 02L pg/L 1 U 0.22 J 0.64 0.44 J 3.3 0.5 U 0.26 J 0.38 J Barium 7440-39-3 D - p /L 358 310 330 380 23 20 12 13 Barium 7440-39-3 T 700 02L pg/L 553 260 360 390 67 22 14 23 Ter Ilium 7440-41-7 D - pg/L 1 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Beryllium 7440-41-7 T 4 IMAC pg/L 1 U 0.2 U 0.2 U 0.2 U 0.65 0.2 U 0.2 U 0.2 U Boron 7440-42-8 D - pg/L 50 U 50 U 50 U 50 U 30 J+ 50 U 50 U 50 U Boron 7440-42-8 T 700 02L p /L 50 U 50 U 50 U 50 U 50 U 50 U 50 U 50 U Cadmium 7440-43-9 D - p /L 1 U 0.08 U 0.08 U 0.038 J 0.036 J 0.035 J 0.08 U 0.08 U Cadmium 7440-43-9 T 2 02L pg/L 1 U 0.028 J 0.027 J 0.043 J 0.13 0.036 J 0.08 U 0.049 J Calcium 7440-70-2 T - p /L 97600 64300 758000 J- 768000 2780 1520 20600 23000 Chromium 7440-47-3 D - p /L 3.85 16.8 144 247 0.38 J+ 0.27 J 2.5 0.54 Chromium 7440-47-3 T 10 02L p /L 16.7 192 186 164 J+ 133 0.54 J+ 3.2 2.3 Cobalt 7440-48-4 D - pg/L 1 U 0.5 U 0.5 U 2.2 3 2.2 0.14 J 0.5 U Cobalt 7440-48-4 T 1 IMAC p /L 1 U 1.8 1.9 0.28 J 12.7 2.1 0.22 J 1.2 Copper 7440-50-8 D - pg/L 1 U 2.3 2 J+ 7.3 0.52 J+ 4 0.37 J 1.1 Copper 7440-50-8 T 1000 02L p /L 2.71 5.7 9.2 11.3 29.7 1.6 0.65 J 6.8 Iron 7439-89-6 D - pg/L 10 U 50 U 50 U 50 U 34 J 50 U 50 U 50 U Iron 7439-89-6 T 300 02L p /L 143 1200 660 620 9500 320 100 1600 Lead 7439-92-1 D - pg/L 1 U 0.44 0.71 J+ 1.3 0.058 J+ 0.24 0.1 U 0.099 J Lead 7439-92-1 T 15 02L pg/L 1 U 0.24 J+ 1.1 2.5 7.5 0.082 J 0.057 J 0.49 Magnesium 7439-95-4 T - pg/L 904 164 100 U 100 U 1160 1280 4110 4250 Manganese 7439-96-5 D - p /L 5 U 5 U 5 U 5 U 150 87 10 9.6 Manganese 7439-96-5 T 50 02L pg/L 5 U 6.7 15 12 320 89 14 62 Mercury 7439-97-6 D - p /L 0.05 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.14 J+ 0.1 J+ Mercury 7439-97-6 T 1 02L pg/L 0.05 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.096 J+ 0.13 J+ Methane 74-82-8 N - p /L 2 J+ 2.2 J+ 10 UJ 5.1 J+ 1.3 J+ 2 J+ 2.2 J+ 1.8 J+ Molybdenum 7439-98-7 D pg/L 3.35 19.8 67.3 85 0.5 U 0.5 U 2.6 2.6 Molybdenum 7439-98-7 T p /L 6.06 71 71.8 76.7 14.3 0.5 U 2.9 2.7 Nickel 7440-02-0 D - pg/L 1 U 0.97 0.27 J 48.1 7.3 2 1.5 0.5 U Nickel 7440-02-0 T 100 02L p /L 12 245 18.5 4 40.5 2.1 2.2 1.3 Potassium 7440-09-7 T - pg/L 52400 107000 188000 468000 5000 U 5000 U 5000 U 2860 J Selenium 7782-49-2 D - p /L 1 U 1.5 5.9 8 0.5 U 0.5 U 0.26 J 0.22 J Selenium 7782-49-2 T 20 02L pg/L 1 U 1.5 6.7 8.8 0.31 J 0.5 U 0.26 J 0.25 J Sodium 7440-23-5 T - p /L 31400 36500 73900 120000 4430J 4010J 13100 13100 Strontium 7440-24-6 D pg/L 2720 2700 4300 6400 24 J+ 14 130 140 Strontium 7440-24-6 T pg/L 4000 2200 4500 6100 34 14 150 170 Thallium 7440-28-0 D - pg/L 0.2 U 0.051 J 3.1 3.3 0.04 J 0.051 J 0.1 U 0.023 J Thallium 7440-28-0 T 0.2 IMAC p /L 0.2 U 0.05 J 3.2 3.1 0.087 J 0.045 J 0.1 U 0.04 J Vanadium 7440-62-2 D - pg/L 3.1 4.3 0.66 J 1.9 1 U 1 U 6.1 5.9 Vanadium 7440-62-2 T 0.3 IMAC p /L 3.43 4.7 2.1 0.47 J 23 0.44 J 6.2 9.3 Zinc 7440-66-6 D - pg/L 5 U 10 U 10 U 5.9 J 18 J+ 23 J+ 10 U 10 U Zinc 7440-66-6 T 1000 02L p /L 5 U 10 U 5.7 J+ 10 J+ 64 14 10 U 2.8 J Total Dissolved Solids TDS N 500000 02L g/L 380000 550000 2900000 3360000 31000 25000 U 142000 62000 Total Organic Carbon TOC N - p /L 3600 1700 8300 14100 J+ 1000 U 1000 U 580 J 1100 Total Suspended Solids TSS N pg/L 11000 14200 25200 350000 31300 45600 4900 U 36300 -Alkalinity, CO3 ALK-0O3 N p /L 602000 306000 1370000 103000 5000 U 5000 U 5000 U 2900 J Alkalinity, HCO3 ALK-HCO3 N pg/L 5000 U 5000 U 5000 U 5000 U 7800 7900 J+ 80700 81400 Alkalinity, lab ALK-LAB N - p /L 1090000 323000 2170000 J 2380000 7800 7900 J+ 80700 84300 Chloride 16887-00-6 N 250000 02L pg/L 1900 3700 9800 15200 8100 8800 2300 2300 Fluoride 16984-48-8 N - p /L - 981 - 260 - - - - Nitrogen, NO2 plus NO3 NO2-NO3 N - pg/L 12 J 22 59 16 J 20 U 191 20 U 20 U Sulfate 14808-79-8 N 250000 02L pg/L 5800 32300 376000 J+ 400000 980 J 660 J 12400 11700 Sulfide 18496-25-8 N - pg/L 100 U 100 U 100 U 100 U 100 U 100 U 100 U 100 U Arsenic 7440-38-2 1 T 10 02L p /L - - - - - - - - Chromium 7440-47-3 1 T 10 1 02L I pg/L Page 3 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: GWA-20BR GWA-20BR GWA-20D GWA-20D GWA-20S GWA-20S GWA-21BR GWA-21BR Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 Round 1 7/27/2015 9/19/2015 7/16/2015 9/19/2015 7/11/2015 9/16/2015 8/27/2015 8/27/2015 N N N N N N N N GWA-20BR RV-GWA-20BR-NS-3015 GWA-20D RV-GWA-20D-NS-3Q15 GWA-20S RV-GWA-20S-NS-3Q15 GWA-21BR 1-G GWA-21BR 2-113P Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Iron 7439-89-6 T 300 02L N /L Manganese 7439-96-5 D /L Manganese 7439-96-5 T 50 02L I pg/L As III 7784-46-5 T /L As V 10103-60-3 T - N /L Chromium VI 18540-29-9 D 0.07 DHHS /L Chromium VI 18540-29-9 T 0.07 DHHS /L Fe II 1345-25-1 T /L Fe III 1309-37-1 T /L Mn II 1344-43-0 T /L Mn IV 1313-13-9 T /L Se IV 10102-18-8 T /L Se VI 13410-01-0 T /L Uranium, Natural 7440-61-1 T /L Radium-226 13982-63-3 T Ci/L Radium-228 15262-20-1 T Ci/L Uranium-233 13968-55-3 T /L Uranium-234 13966-29-5 T /L Uranium-236 13982-70-2 T /L - - - - - - Dissolved Oxygen DO N m /L 6 3.7 4.9 5.3 3.9 6.22 Temperature TEMP N - - Deg C 18.9 18.5 21.1 17.6 27.1 18.6 H PH N 6.5 8.5 02L SU 11.9 11.6 12.5 13.56 5.3 5.2 Turbidity, field TURB N - - NTU 8.62 4.8 8.95 3.86 21.15 8.4 Specific Conductivity field SC NPS/cm 2401 17.21 1 11175 10004 45.2 88.1 Oxidation Reduction Potential ORP N mV -45.8 -11.2 74.2 94.4 126.8 309.6 GW Depth TOC GW DEPTH-TOC N ft 46.75 42.42 Notes pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 4 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: GWA-21BR GWA-21BR GWA-21D GWA-21S GWA-21S GWA-22BR GWA-22BR GWA-22D Round 2 Round 2 Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 9/15/2015 9/17/2015 9/18/2015 8/14/2015 9/16/2015 7/21/2015 9/18/2015 7/10/2015 N N N N N N N N RV-GWA-2IBR-NS-3Q15 RV-GWA-2IBR-NS-3Q15 RV-GWA-21D-NS-3Q15 GWA-21S RV-GWA-21S-NS-3Q15 GWA-22BR RV-GWA-22BR-NS-3Q15 GWA-22D Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D p /L 100 U 100 U 100 U 100 U 100 U 314 100 250 Aluminum 7429-90-5 T pg/L 150 56 J 9300 110 J+ 890 J+ 766 210 6000 Antimony 7440-36-0 D p /L 0.86 0.5 U 0.5 U 0.5 U 0.5 U 1 U 0.65 0.5 U Antimony 7440-36-0 T 1 IMAC pg/L 2.3 0.36 J 0.15 J 0.5 U 0.5 U 1 U 0.7 1.4 Arsenic 7440-38-2 D - p /L 0.2 J 0.26 J 0.18 J 0.5 U 0.5 U 1 U 1.3 0.78 Arsenic 7440-38-2 T 10 02L pg/L 0.34 J 0.35 J 0.27 J 0.5 U 0.5 U 1 U 1.3 0.91 Barium 7440-39-3 D - p /L 78 20 9.5 72 69 36 5.1 16 Barium 7440-39-3 T 700 02L pg/L 1 110 19 27 86 77 185 5.2 61 -Beryllium 7440-41-7 D - pg/L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 1 U 0.2 U 0.2 U Beryllium 7440-41-7 T 4 IMAC pg/L 0.2 U 0.2 U 0.074 J 0.2 U 0.2 U 1 U 0.2 U 0.28 Boron 7440-42-8 D - pg/L 50 U 50 U 50 U 50 U 50 U 50 U 50 U 50 U Boron 7440-42-8 T 700 02L p /L 50 U 50 U 50 U 50 U 50 U 50 U 50 U 50 U Cadmium 7440-43-9 D - p /L 0.08 U 0.08 U 0.08 U 0.025 J 0.029 J 1 U 0.08 U 0.08 UJ Cadmium 7440-43-9 T 2 02L pg/L 0.032 J 0.08 U 0.08 U 0.032 J 0.033 J 1 U 0.057 J 0.08 U Calcium 7440-70-2 T p /L 17200 20900 25300 359 J+ 247 303000 19900 44400 Chromium 7440-47-3 D - p /L 8.9 1.3 1.5 J+ 0.83 J+ 0.29 J 49.5 15 171 Chromium 7440-47-3 T 10 02L p /L 11.4 10.8 17.6 1.5 J+ 1.8 J+ 108 29 174 Cobalt 7440-48-4 D - pg/L 0.5 U 0.16 J 0.5 U 4 4.5 1 U 0.5 U 0.5 U Cobalt 7440-48-4 T 1 IMAC p /L 0.16 J 0.36 J 2.5 4 4.8 1 U 0.54 3.4 Copper 7440-50-8 D - pg/L 1.7 1 U 0.44 J+ 0.71 J+ 10.1 2.01 1.3 0.48 J Copper 7440-50-8 T 1000 02L p /L 2.5 1.6 17.7 0.3 J+ 1.1 4.28 1.2 12.3 Iron 7439-89-6 D - pg/L 50 U 50 U 50 U 50 U 50 U 10 U 50 U 50 U Iron 7439-89-6 T 300 02L p /L 110 49J 5200 120 J+ 2600 61 170 2600 Lead 7439-92-1 D - pg/L 0.089 J 0.1 U 0.1 U 0.047 J+ 1.1 1 U 0.15 0.1 UJ Lead 7439-92-1 T 15 02L pg/L 0.24 0.13 0.23 0.1 U 0.46 1 U 0.1 1.2 Magnesium 7439-95-4 T - pg/L 550 4250 4120 144 150 53 1070 1240 Manganese 7439-96-5 D - p /L 5 U 28 7.8 550 440 5 U 5 U 5 U Manganese 7439-96-5 T 50 02L pg/L 3.4 J 31 120 660 440 5 U 2.7 J 120 Mercury 7439-97-6 D - p /L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.05 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L pg/L 0.2 U 0.18 J+ 0.2 U 0.2 U 0.2 U 0.05 U 0.2 U 0.2 U Methane 74-82-8 N - p /L 2.1 J+ 1.8 J+ 2.5 J+ 0.74 J+ 1.9 J+ 1.4 J+ 0.84 J+ 10 UJ Molybdenum 7439-98-7 D pg/L 6 2.5 3.6 0.5 U 0.5 U 670 188 5.3 Molybdenum 7439-98-7 T p /L 6 3.4 4.9 0.5 U 0.13 J 946 199 7.1 Nickel 7440-02-0 D - pg/L 0.37 J 0.66 0.62 J+ 1.2 J+ 1.4 1 U 1.1 0.5 UJ Nickel 7440-02-0 T 100 02L p /L 0.54 6.5 J+ 8.4 1.4 J+ 1.7 3.51 15.6 5.7 Potassium 7440-09-7 T - pg/L 153000 J- 5000 U 9670 5000 U 5000 U 9360 2700 J 34600 Selenium 7782-49-2 D - p /L 0.72 0.5 U 0.38 J 0.5 U 0.5 U 4.21 1.7 0.64 Selenium 7782-49-2 T 20 02L pg/L 0.73 0.5 U 0.85 0.5 U 0.5 U 4.39 1.8 1.1 Sodium 7440-23-5 T - p /L 50000 11400 12600 2800J 2680J 27400 19100 29400 Strontium 7440-24-6 D pg/L 590 160 170 5 U 2.6 J 336 120 240 Strontium 7440-24-6 T pg/L 800 150 300 2.6 J 5 U 1370 100 420 Thallium 7440-28-0 D - pg/L 0.091 J 0.1 U 0.1 U 0.072 J+ 0.079 J 0.2 U 0.1 U 0.1 U Thallium 7440-28-0 T 0.2 IMAC p /L 0.11 0.1 U 0.017 J 0.064 J+ 0.14 0.2 U 0.1 U 0.1 U Vanadium 7440-62-2 D - pg/L 3.6 4.7 6.2 1 U 1 U 9.95 9.5 16.1 Vanadium 7440-62-2 T 0.3 IMAC p /L 4 6 10.4 1 U 1.4 4.33 10.3 18.5 Zinc 7440-66-6 D - pg/L 3 J 2.6 J+ 3.4 J+ 2.9 J 11 J+ 5 U 6.3 J+ 10 UJ Zinc 7440-66-6 T 1000 02L p /L 8.9 J 11 J+ 11 3.7 J 14 9 3.9 J 14 J+ Total Dissolved Solids TDS N 500000 02L g/L 380000 134000 154000 25000 U 25000 U 360000 148000 214000 Total Organic Carbon TOC N - p /L 22500 1000 U 1900 1000 U 1000 U 2200 1000 6800 Total Suspended Solids TSS N pg/L 110000 2500 U 112000 10200 J+ 185000 5000 U 10500 13100 Alkalinity, CO3 ALK-0O3 N p /L 73900 2600 J 21100 831000 J 5000 U 142000 41600 92500 Alkalinity, HCO3 ALK-HCO3 N pg/L 75100 72300 72300 5000 U 2100 J+ 5000 U 16400 48200 Alkalinity, lab ALK-LAB N p /L 149000 74900 93400 5720000 2100 J+ 332000 J+ 58000 141000 Chloride 16887-00-6 N 250000 02L pg/L 3900 2000 3100 2200 J- 2000 7400 5300 5700 Fluoride 16984-48-8 N - p /L - - 100 - - - 200 J+ - Nitrogen, NO2 plus NO3 NO2-NO3 N - pg/L 20 U 23 25 1100 1000 87 20 U 55 Sulfate 14808-79-8 N 250000 02L pg/L 15900 10200 17400 1000 U 1000 U 21000 30900 23500 Sulfide 18496-25-8 1 N pg/L 100 U 100 U 100 U 100 U 100 U 100 U 100 U 100 U Arsenic 7440-38-2 T 10 02L I p /L - Chromium 1 7440-47-3 1 T I 1 10 1 02L I pg/L Page 5 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: GWA-21 BR GWA-21 BR GWA-21 D GWA-21 S GWA-21S GWA-22BR GWA-22BR GWA-22D Round 2 Round 2 Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 9/15/2015 9/17/2015 9/18/2015 8/14/2015 9/16/2015 7/21/2015 9/18/2015 7/10/2015 N N N N N N N N RV-GWA-21I3R-NS-3Q15 RV-GWA-2IBR-NS-3Q15 RV-GWA-2ID-NS-3Q15 GWA-21S RV-GWA-2IS-NS-3Q15 GWA-22BR RV-GWA-2213R-NS-3Q15 GWA-22D Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Iron 7439-89-6 T 300 02L N /L Manganese 7439-96-5 D /L Manganese 7439-96-5 T 50 02L I pg/L As III 7784-46-5 T /L As V 10103-60-3 T - N /L Chromium VI 18540-29-9 D 0.07 DHHS /L Chromium VI 18540-29-9 T 0.07 DHHS /L Fe II 1345-25-1 T /L Fe III 1309-37-1 T /L Mn II 1344-43-0 T /L Mn IV 1313-13-9 T /L Se IV 10102-18-8 T /L Se VI 13410-01-0 T /L Uranium, Natural 7440-61-1 T /L Radium-226 13982-63-3 T Ci/L Radium-228 15262-20-1 T Ci/L Uranium-233 13968-55-3 T /L Uranium-234 13966-29-5 T /L Uranium-236 13982-70-2 T /L - - - - - - - Dissolved Oxygen DO N m /L 0.25 3 1.3 5.72 5 1.57 8.5 Temperature TEMP N - - Deg C 22.1 19.6 20.6 18.6 21.1 26.3 21.3 H PH N 6.5 8.5 02L SU 11.7 8.4 9.2 5 11.4 9.96 11 Turbidity, field TURB N - - NTU 12.2 2.2 155.6 10 1.04 7.98 71.72 Specific Conductivity field SC NPS/cm 2481 184.8 201.4 43.9 1240 239 411.1 Oxidation Reduction Potential ORP N mV -167.4 22.7 -23.7 263.5 49.8 -27.2 60.3 GW Depth TOC GW DEPTH-TOCI N I I ft 78.1 91.39 73.3 63.9 59.57 Notes pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 6 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: GWA-22D GWA-22S GWA-22S GWA-23BR GWA-23BR GWA-23D GWA-23D GWA-23S Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 9/17/2015 7/10/2015 9/16/2015 7/17/2015 9/19/2015 7/16/2015 9/18/2015 7/10/2015 N N N N N N N N RV-GWA-22D-NS-3Q15 GWA-22S RV-GWA-22S-NS-3Q15 GWA-23BR RV-GWA-23BR-NS-3Q15 GWA-23D RV-GWA-23D-NS-3Q15 GWA-23S Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D p /L 140 100 U 100 U 260 340 J+ 500 600 140 Aluminum 7429-90-5 T pg/L 400 180 9900 J+ 490 1400 560 560 170 Antimony 7440-36-0 D p /L 0.17 J 3.5 - 0.5 U 1.8 0.5 U 0.5 U 0.5 U Antimony 7440-36-0 T 1 IMAC pg/L 0.17 J 2.2 0.5 U 0.5 U 1.3 0.5 U 0.5 U 0.24 J Arsenic 7440-38-2 D - p /L 0.59 0.5 U - 0.5 U 0.11 J 0.82 J+ 0.78 0.5 U Arsenic 7440-38-2 T 10 02L pg/L 0.6 0.5 U 0.5 U 0.28 J 0.18 J 0.9 0.83 0.5 U Barium 7440-39-3 D - p /L 24 31 28 140 180 J+ 14 14 38 Barium 7440-39-3 T 700 02L pg/L 27 34 160 130 160 15 12 37 Beryllium 7440-41-7 D - pg/L 0.2 U 0.08 J - 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Beryllium 7440-41-7 T 4 IMAC pg/L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Boron 7440-42-8 D - pg/L 50 U 50 U 50 U 50 U 50 U 37 J 50 U 50 U Boron 7440-42-8 T 700 02L p /L 50 U 50 U 50 U 50 U 50 U 50 U 50 U 50 U Cadmium 7440-43-9 D - p /L 0.08 U 0.078 J+ - 0.08 U 0.08 U 0.08 U 0.08 U 0.038 J+ Cadmium 7440-43-9 T 2 02L pg/L 0.08 U 0.075 J 0.033 J 0.08 U 0.08 U 0.08 U 0.08 U 0.04 J Calcium 7440-70-2 T - p /L 17500 696 1100 307000 187000 46400 40900 858 Chromium 7440-47-3 D - p /L 115 0.77 J+ - 13.4 8.9 53.6 39.1 0.54 J+ Chromium 7440-47-3 T 10 02L p /L 125 1.9 J+ 1.6 J+ 15.6 17 55 54 3.2 J+ Cobalt 7440-48-4 D - pg/L 0.5 U 1.2 - 0.5 U 0.5 U 0.5 U 0.5 U 3.1 Cobalt 7440-48-4 T 1 IMAC p /L 0.13 J 1.3 1.2 0.5 U 0.17 J 0.5 U 0.71 3.3 Copper 7440-50-8 D - pg/L 1.4 5 - 2 J+ 1.3 1.2 J+ 3.7 0.95 J+ Copper 7440-50-8 T 1000 02L p /L 1 5 0.73 J 1.1 2 2 5 9.9 Iron 7439-89-6 D - pg/L 50 U 50 U 50 U 50 U 50 U 50 U 50 U 50 U Iron 7439-89-6 T 300 02L p /L 190 94 5600 140 860 33J 170 530 Lead 7439-92-1 D - pg/L 0.19 0.062 J+ - 0.19 0.12 0.1 UJ 0.57 0.094 J+ Lead 7439-92-1 T 15 02L pg/L 0.053 J 0.071 J 0.18 0.31 0.14 J+ 0.1 U 0.14 0.18 Magnesium 7439-95-4 T - pg/L 397 431 742 257 1460 50.3 J 62 J 435 Manganese 7439-96-5 D - p /L 5 U 44 37 5 U 5 U 5 U 5 U 81 Manganese 7439-96-5 T 50 02L pg/L 6 48 320 4.4 J 22 5 U 3.3 J 82 Mercury 7439-97-6 D - p /L 0.2 U 0.2 U 0.2 U 0.098 J 0.2 U 0.2 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L pg/L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Methane 74-82-8 N - p /L 3.1 J+ 10 UJ 1.3 J+ 1.9 J+ 2.1 J+ 1.5 J+ 1.6 J+ 2.1 J+ Molybdenum 7439-98-7 D pg/L 5.2 0.5 U - 4.8 6.9 6.5 5 0.5 U Molybdenum 7439-98-7 T p /L 5.3 0.1 J 0.5 U 5.2 7.8 4.9 8.3 0.13 J Nickel 7440-02-0 D - pg/L 0.5 U 0.93 J+ - 0.5 U 0.86 0.5 U 2.4 2.3 J+ Nickel 7440-02-0 T 100 02L p /L 0.3 J 1.1 J+ 2.3 0.52 7.4 0.36 J 24 3.5 Potassium 7440-09-7 T - pg/L 7110 5000 U 5000 U 27700 J 22600 5000 U 5000 U 5000 U Selenium 7782-49-2 D - p /L 0.63 0.5 U - 0.38 J 0.22 J 0.39 J 0.21 J 0.5 U Selenium 7782-49-2 T 20 02L pg/L 0.73 0.5 U 0.5 U 0.3 J 0.22 J 0.4 J 0.33 J 0.5 U Sodium 7440-23-5 T - p /L 15600 5000 U 5000 U 23300 20300 13800 14600 2510 J Strontium 7440-24-6 D pg/L 220 13 8.9 990 1200 J+ 200 210 6.5 Strontium 7440-24-6 T pg/L 210 13 19 910 950 210 180 9.9 Thallium 7440-28-0 D - pg/L 0.1 U 0.02 J - 0.077 J 0.037 J 0.1 UJ 0.1 U 0.1 U Thallium 7440-28-0 T 0.2 IMAC p /L 0.1 U 0.02 J 0.019 J 0.077 J 0.035 J 0.1 U 0.1 U 0.1 U Vanadium 7440-62-2 D - pg/L 17 1 U - 3.9 2.8 31.9 33.2 1 U Vanadium 7440-62-2 T 0.3 IMAC p /L 17.8 1 U 0.51 J 5.3 3.3 34.1 34.5 1 U Zinc 7440-66-6 D - pg/L 3.2 J 35 J+ 9.5 J+ 10 U 12 10 U 4 J+ 14 J+ Zinc 7440-66-6 T 1000 02L p /L 4.8 J+ 19 J+ 51 200 J 12 3.8 J+ 3.1 J 19 J+ Total Dissolved Solids TDS N 500000 02L g/L 143000 25000 U 25000 U 790000 400000 196000 174000 27000 Total Organic Carbon TOC N - p /L 4700 1000 U 1000 U 820 J 730 J 670 J 3300 1000 U Total Suspended Solids TSS N pg/L 4200 11900 46400 39700 88000 2500 U 12400 21900 Alkalinity, CO3 ALK-0O3 N p /L 67600 5000 U 5000 U 217000 492000 98200 72400 5000 U Alkalinity, HCO3 ALK-HCO3 N pg/L 5000 UJ 2900 J 4200 J+ 5000 U 21500 44400 5000 U 8400 Alkalinity, lab ALK-LAB N - p /L 80900 2900 J 4200 J+ 800000 514000 143000 J 115000 8400 Chloride 16887-00-6 N 250000 02L pg/L 3000 2800 2800 2000 1900 2600 2400 2300 Fluoride 16984-48-8 N - p /L - - - - 120 - 170 J+ - Nitrogen, NO2 plus NO3 NO2-NO3 N - pg/L 46 14 J 34 75 16 J 20 UJ 11 J 480 Sulfate 14808-79-8 N 250000 02L pg/L 12000 1000 U 1000 U 18000 6400 10600 9300 1000 U Sulfide 18496-25-8 N - pg/L 100 U 100 U 100 U 100 U 100 U 100 U 100 U 100 U Arsenic 7440-38-2 T 10 02L p /L - 0.748 - 0.5 U - 0.808 - - Chromium 7440-47-3 T 10 02L pg/L 1.05 15.1 56.3 Page 7 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: GWA-22D GWA-22S GWA-22S GWA-23BR GWA-23BR GWA-23D GWA-23D GWA-23S Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 9/17/2015 7/10/2015 9/16/2015 7/17/2015 9/19/2015 7/16/2015 9/18/2015 7/10/2015 N N N N N N N N RV-GWA-22D-NS-3Q15 GWA-22S RV-GWA-22S-NS-3Q15 GWA-23BR RV-GWA-23BR-NS-3Q15 GWA-23D RV-GWA-23D-NS-3Q15 GWA-23S Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Iron 7439-89-6 T 300 02L N /L 26.5 J 223 100 U Manganese 7439-96-5 D /L 42.9 2 U 2 U Manganese 7439-96-5 T 50 02L I pg/L 44.2 10.8 2 U As III 7784-46-5 T /L 0.5 U 0.5 U 0.5 U As V 10103-60-3 T - N /L 0.748 0.5 U 0.808 Chromium VI 18540-29-9 D 0.07 DHHS /L - 13 51 Chromium VI 18540-29-9 T 0.07 DHHS /L - - - Fe II 1345-25-1 T /L 40 U 30 UJ Fe III 1309-37-1 T /L - Mn II 1344-43-0 T /L Mn IV 1313-13-9 T /L - Se IV 10102-18-8 T /L 2 U 1.4 J 2 U Se VI 13410-01-0 T /L 2 U 2 U 2 U Uranium, Natural 7440-61-1 T /L Radium-226 13982-63-3 T Ci/L Radium-228 15262-20-1 T Ci/L Uranium-233 13968-55-3 T /L Uranium-234 13966-29-5 T /L Uranium-236 13982-70-2 T /L Dissolved Oxygen DO N m /L 4.78 3.45 5.39 3.8 1.9 6.4 4.7 3.1 Temperature TEMP N - - Deg C 17.5 32.8 22.4 23.2 30.1 21.7 23.3 24.9 H PH N 6.5 8.5 02L SU 10.2 5.18 5.2 12.2 11.5 11.2 11.09 5.3 Turbidity, field TURB N - - NTU 7.9 8.32 9.74 10.2 8.1 4.15 5.52 9.05 Specific Conductivity field SC NPS/cm 201.6 22 38.5 3584 2662 452.3 446.4 44.1 Oxidation Reduction Potential ORP N mV 175.9 239.9 284.9 -89.4 -208.7 31.7 -135.5 227.3 GW Depth TOC GW DEPTH-TOC N - 1 ft 43.72 Notes pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 8 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: GWA-23S GWA-2BR GWA-2BR GWA-21BRU GWA-21BRU GWA-2S GWA-2S GWA-3D Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 9/16/2015 6/17/2015 9/17/2015 7/8/2015 9/17/2015 6/22/2015 9/18/2015 6/17/2015 N N N N N N N N RV-GWA-23S-NS-3Q15 GWA-2BR RV-GWA-2BR-NS-3Q15 GWA-21BRU RV-GWA-2BRU-NS-3Q15 GWA-2S RV-GWA-2S-NS-3Q15 GWA-3D Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D /L 100 U 100 U 100 U 460 3300 100 U 100 U 73 J Aluminum 7429-90-5 T /L 82 J 66 J 1200 2300 3100 570 5200 92 J Antimony 7440-36-0 D I pg/L 0.5 U 0.25 J 0.5 22.4 1.2 0.5 U 0.5 U 0.5 U Antimony 7440-36-0 T 1 IMAC /L 0.5 U 0.24 J 0.4 J 18.2 1.2 0.5 U 0.5 U 0.5 U Arsenic 7440-38-2 D - lJ/L 0.5 U 1.4 1.7 0.18 J 1.1 0.14 J 0.64 0.72 Arsenic 7440-38-2 T 10 02L /L 1 0.5 U 1.3 1.8 J+ 0.36 J 1.5 J+ 0.28 J 0.72 0.65 Barium 7440-39-3 D /L 31 7.7 8.3 280 110 43 50 44 Barium 7440-39-3 T 700 02L /L 31 7.7 19 280 100 52 110 49 Beryllium 7440-41-7 D /L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Beryllium 7440-41-7 T 4 IMAC /L 0.2 U 0.2 U 0.2 UJ 0.2 U 0.2 UJ 0.2 U 0.1 J 0.2 U Boron 7440-42-8 D /L 50 U 50 U 50 U 50 U 50 U 440 520 34 J Boron 7440-42-8 T 700 02L /L 50 U 50 U 50 U 50 U 50 U 460 480 34 J Cadmium 7440-43-9 D /L 0.026 J 0.08 U 0.08 U 0.08 U 0.08 U 0.032 J 0.08 U 0.14 Cadmium 7440-43-9 T 2 02L /L 0.036 J 0.08 U 0.08 UJ 0.08 U 0.08 UJ 0.08 U 0.08 U 0.11 Calcium 7440-70-2 T /L 1220 27400 46800 343000 176000 13200 14000 437000 Chromium 7440-47-3 D /L 0.61 3.4 0.74 22.9 38.4 1 J+ 0.91 0.86 Chromium 7440-47-3 T 10 02L /L 0.82 J+ 7.4 9 J+ 46 40.2 J+ 2.8 J+ 4.4 J+ 1.1 Cobalt 7440-48-4 D /L 3.3 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 1.2 Cobalt 7440-48-4 T 1 IMAC /L 3.2 0.5 U 0.29 J+ 0.81 0.5 UJ 0.34 J 2.4 1.1 Copper 7440-50-8 D /L 14.7 0.27 J 0.97 J 4.1 J+ 4.7 1.2 J+ 0.32 J 2.1 Copper 7440-50-8 T 1000 02L N /L 2.3 0.49 J 1.5 J+ 8.2 3.9 J+ 1.3 3.5 4.2 Iron 7439-89-6 D /L 27 J 50 U 50 U 50 U 50 U 50 U 50 U 50 U Iron 7439-89-6 T 300 02L /L 58 64 1300 1500 52 590 5200 50 U Lead 7439-92-1 D /L 1.5 0.1 U 0.21 0.53 0.28 0.066 J 0.09 J 0.1 U Lead 7439-92-1 T 15 02L /L 0.13 0.048 J 0.19 J+ 0.81 0.12 J+ 0.076 J 0.26 0.1 U Magnesium 7439-95-4 T /L 404 4350 4880 196 100 U 7360 8280 113000 Manganese 7439-96-5 D /L 86 3.5 J 8.6 5 U 5 U 56 43 11600 Manganese 7439-96-5 T 50 02L /L 82 5 UJ 60 61 5 U 95 290 9200 Mercury 7439-97-6 D /L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.1 J+ 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L /L 0.2 U 0.15 J+ 0.2 U 0.2 U 0.2 U 0.088 J+ 0.2 U 0.13 J+ Methane 74-82-8 N /L 10 UJ 3.3 J+ 5 J+ 2.2 J+ 3.5 J+ 2.1 J+ 2.4 J+ 2.3 J+ Molybdenum 7439-98-7 D /L 0.5 U 6.1 8.5 53.5 38.3 0.5 U 0.5 U 5.6 Molybdenum 7439-98-7 T /L 0.5 U 5.9 7.6 J+ 60.1 38.9 J+ 0.1 J 0.1 J 6.8 Nickel 7440-02-0 D /L 2.3 0.65 0.21 J 0.74 J+ 0.69 0.45 J 0.88 57.4 Nickel 7440-02-0 T 100 02L /L 2.2 2.9 3.2 J+ 8.4 0.8 J+ 0.81 J+ 3.7 49.8 Potassium 7440-09-7 T /L 5000 U 8930 9220 253000 119000 5000 U 5000 U 11400 Selenium 7782-49-2 D - lJ/L 0.5 U 1.3 0.86 1.7 0.87 0.5 U 0.5 U 5.8 Selenium 7782-49-2 T 20 02L /L 0.5 U 1.2 0.77 2.3 0.92 0.5 U 0.5 U 5.2 Sodium 7440-23-5 T /L 5000 U 9360 9000 162000 82900 6490 6000 48000 Strontium 7440-24-6 D pg1L 14 150 150 2900 1500 180 200 2000 Strontium 7440-24-6 T /L 12 150 200 2900 1500 180 200 2000 Thallium 7440-28-0 D /L 0.016 J 0.1 U 0.1 U 0.025 J 0.023 J 0.1 U 0.1 U 0.016 J Thallium 7440-28-0 T 0.2 IMAC /L 0.1 U 0.1 U 0.1 UJ 0.03 J 0.1 UJ - 0.02 J 0.1 U Vanadium 7440-62-2 D /L 1 U 12.3 3.6 1 U 0.86 J 1.1 1.1 4.3 Vanadium 7440-62-2 T 0.3 IMAC /L 0.58 J 11.8 4.4 J+ 4 1 J+ 2.3 7.2 4.6 Zinc 7440-66-6 D /L 32 J+ 3 J+ 9.3 J 5.2 J 15 5.8 J 20 J+ 14 J+ Zinc 7440-66-6 T 1000 02L /L 30 10 U 32 J+ 15 J+ 12 J+ 5.4 J 48 29 J+ Total Dissolved Solids TDS N 500000 02L /L 41000 164000 160000 18100000 250000 U 132000 131000 2390000 Total Organic Carbon TOC N /L 820 J 910 J 540 J 6900 9400 1000 U 1000 U 1100 Total Suspended Solids TSS N /L 12600 5000 U 187000 792000 8200 8400 129000 3100 U Alkalinity, CO3 ALK-0O3 N /L 5000 U 5000 U 4100 J 1150000 61500 5000 U 5000 U 5000 U Alkalinity, HCO3 ALK-HCO3 N /L 6200 J+ 64100 59600 5000 U 5000 UJ 32000 27500 72900 Alkalinity, lab ALK-LAB N N /L 6200 J+ 64100 63700 1510000 J+ 768000 32000 27500 72900 Chloride 16887-00-6 N 250000 02L /L 2600 5200 5400 - 10600 5800 6200 6500 Fluoride 16984-48-8 N /L - - - - - - 76 J - Nitro en, NO2 plus NO3 NO2-NO3 N /L 510 20 U 20 U 160 140 320 340 46 Sulfate 14808-79-8 N 250000 02L pg/L 490 J 39500 42100 3000 5400 36100 40800 1310000 Sulfide 18496-25-8 N /L 100 U 100 U 100 U 100 U 100 U 100 U 100 U 100 U Arsenic 7440-38-2 T 10 02L /L Chromium 7440-47-3 T 10 02L /L Page 9 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: GWA-23S GWA-213R GWA-2BR GWA-21BRU GWA-21BRU GWA-2S GWA-2S GWA-3D Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 9/16/2015 6/17/2015 9/17/2015 7/8/2015 9/17/2015 6/22/2015 9/18/2015 6/17/2015 N N N N N N N N RV-GWA-23S-NS-3Q15 GWA-213R RV-GWA-2BR-NS-3Q15 GWA-21BRU RV-GWA-2BRU-NS-3Q15 GWA-2S RV-GWA-2S-NS-3Q15 GWA-3D Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Iron 7439-89-6 T 300 02L N /L Manganese 7439-96-5 D /L Manganese 7439-96-5 T 50 02L I pg/L As III 7784-46-5 T /L As V 10103-60-3 T - N /L Chromium VI 18540-29-9 D 0.07 DHHS /L Chromium VI 18540-29-9 T 0.07 DHHS /L Fe II 1345-25-1 T - /L Fe III 1309-37-1 T /L Mn II 1344-43-0 T /L Mn IV 1313-13-9 T /L Se IV 10102-18-8 T /L Se VI 13410-01-0 T /L Uranium, Natural 7440-61-1 T /L Radium-226 13982-63-3 T Ci/L Radium-228 15262-20-1 T Ci/L Uranium-233 13968-55-3 T /L Uranium-234 13966-29-5 T /L Uranium-236 13982-70-2 T /L - - - - - - - Dissolved Oxygen DO N m /L 1.42 0.5 5.22 1.1 1.89 2.2 0.67 Temperature TEMP N - - Deg C 21.9 21.9 20.3 24.3 22.12 21.8 20.55 H PH N 6.5 8.5 02L SU 5 8.7 12.11 11.9 5.83 5.9 7.42 Turbidity, field TURB N - - NTU 2.4 10 116.4 3.5 7.72 41.7 1.55 Specific Conductivity field SC NPS/cm 57.4 240.1 5030 3514 188 1 159.5 1744 Oxidation Reduction Potential ORP N mV 290.8 -78.8 -111.1 -242.6 70.6 205 29.2 GW Depth TOC GW DEPTH-TOC N ft 47.84 Notes pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 10 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: GWA-3D GWA-3SA GWA-3SA GWA-413R GWA-4BR GWA-4D GWA-4D GWA-4S Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 9/15/2015 7/1/2015 9/15/2015 7/27/2015 9/17/2015 7/10/2015 9/17/2015 7/10/2015 N N N N N N N N RV-GWA-3D-NS-3Q15 GWA-3SA RV-GWA-3SA-NS-3Q15 GWA-413R RV-GWA-4BR-NS-3Q15 GWA-4D RV-GWA-4D-NS-3Q15 GWA-4S Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D p /L 100 U 60 J 100 U 448 370 100 U 110 100 U Aluminum 7429-90-5 T pg/L 100 U 270 360 530 390 52 J 310 250 Antimony 7440-36-0 D p /L 0.16 J 0.6 J+ 0.5 U 1.41 4.9 0.17 J 0.5 U 0.5 U Antimony 7440-36-0 T 1 IMAC pg/L 0.19 J 0.77 J+ 0.5 U 1 U 5.8 0.5 U 0.57 0.5 U Arsenic 7440-38-2 D - p /L 0.53 0.21 J 0.66 1 U 0.34 J 0.28 J 0.82 0.5 U Arsenic 7440-38-2 T 10 02L pg/L 0.6 0.23 J 0.76 1 U 0.19 J 0.22 J 0.87 0.5 U Barium 7440-39-3 D - p /L 35 110 34 392 85 26 32 21 Barium 7440-39-3 T 700 02L pg/L 45 100 46 383 82 26 42 26 Beryllium 7440-41-7 D - pg/L 0.2 U 0.2 UJ 0.2 U 1 U 0.2 U 0.2 U 0.2 U 0.24 Beryllium 7440-41-7 T 4 IMAC pg/L 0.2 U 0.2 UJ 0.2 U 1 U 0.2 U 0.2 U 0.2 U 0.26 Boron 7440-42-8 D - pg/L 50 U 50 U 50 U 50 U 50 U 50 U 50 U 50 U Boron 7440-42-8 T 700 02L p /L 35 J 50 UJ 27 J 50 U 50 U 50 UJ 50 U 50 UJ Cadmium 7440-43-9 D - p /L 0.078 J 0.16 0.08 U 1 U 0.08 U 0.093 0.08 U 0.11 Cadmium 7440-43-9 T 2 02L pg/L 0.087 0.19 0.08 U 1 U 0.08 U 0.08 U 0.08 U 0.12 Calcium 7440-70-2 T - p /L 447000 367000 378000 545000 179000 12300 28800 25200 Chromium 7440-47-3 D - p /L 0.31 J 0.55 J+ 0.44 J 29.4 19.3 0.6 0.46 J 2.2 Chromium 7440-47-3 T 10 02L p /L 0.56 J+ 0.53 J+ 1.4 J+ 38.1 23.8 2.1 1.2 J+ 2.1 Cobalt 7440-48-4 D - pg/L 1.4 19.8 4.1 1 U 0.5 U 0.52 0.17 J 1.4 Cobalt 7440-48-4 T 1 IMAC p /L 1.4 18.4 4.4 1 U 0.5 U 0.52 0.38 J 1.7 Copper 7440-50-8 D - pg/L 3.3 0.51 J+ 0.26 J 3.64 2.3 1.8 2.6 0.97 J Copper 7440-50-8 T 1000 02L p /L 2.4 J+ 0.92 J+ 0.98 J+ 3.65 1.8 0.97 J 1.6 0.45 J Iron 7439-89-6 D - pg/L 91 190 4400 10 U 50 U 50 U 50 U 50 U Iron 7439-89-6 T 300 02L p /L 140 420 5000 87 30J 62 230 220 Lead 7439-92-1 D - pg/L 0.31 0.1 UJ 0.1 U 1 U 0.23 0.26 0.28 0.3 Lead 7439-92-1 T 15 02L pg/L 0.1 UJ 0.14 J+ 0.1 J+ 1 U 0.12 0.1 U 0.2 0.083 J Magnesium 7439-95-4 T - pg/L 109000 134000 136000 17 100 U 2950 3680 8040 Manganese 7439-96-5 D - p /L 9500 13600 13500 5 U 5 U 27 28 92 Manganese 7439-96-5 T 50 02L pg/L 12100 12700 13100 5 U 5 U 28 44 120 Mercury 7439-97-6 D - p /L 0.2 U 0.2 U 0.2 U 0.05 U 0.2 U 0.2 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L pg/L 0.2 U 0.2 U 0.2 U 0.05 U 0.2 U 0.2 U 0.2 U 0.2 U Methane 74-82-8 N - p /L 10 U 2.9 J+ 2.1 J+ 2.2 J+ 0.73 J+ 1.9 J+ 1.5 J+ 1.8 J+ Molybdenum 7439-98-7 D pg/L 5.2 0.63 J+ 0.23 J 17.5 9.1 1 2.5 0.5 U Molybdenum 7439-98-7 T p /L 6.1 0.56 J+ 0.3 J 18.2 10.3 1 2.8 0.5 U Nickel 7440-02-0 D pg/L 57.3 61.2 44.1 1 U 0.5 U 3.6 1.3 4.1 Nickel 7440-02-0 T 100 02L p /L 52.8 61.3 42.2 4.86 0.46 J 4.3 2.1 4.5 Potassium 7440-09-7 T - pg/L 10700 10600 8990 106000 42100 5000 U 3090 J 5000 U Selenium 7782-49-2 D - p /L 4.5 5.3 2.5 1 U 0.33 J 0.5 U 0.5 U 0.36 J Selenium 7782-49-2 T 20 02L pg/L 4.6 5.7 2.5 1 U 0.55 0.5 U 0.5 U 0.4 J Sodium 7440-23-5 T - p /L 47400 44000 43700 52500 30400 9800 16400 6660 Strontium 7440-24-6 D pg/L 1900 1900 1700 2380 750 120 170 230 Strontium 7440-24-6 T pg/L 2000 1800 1800 2320 720 130 190 240 Thallium 7440-28-0 D - pg/L 0.1 U 0.1 U 0.1 U 0.2 U 0.1 U 0.094 J 0.1 U 0.1 U Thallium 7440-28-0 T 0.2 IMAC p /L 0.1 U 0.1 U 0.021 J 0.2 U 0.1 U 0.1 UJ 0.02 J 0.1 UJ Vanadium 7440-62-2 D - pg/L 1.2 0.66 J 0.44 J 0.753 6.7 2.4 3.1 0.37 J Vanadium 7440-62-2 T 0.3 IMAC p /L 1.4 1.3 2.1 0.9 8.5 2.4 4 0.84 J Zinc 7440-66-6 D - pg/L 10 U 9.8 J+ 10 U 13 15 7.6 J 2.6 J 53 Zinc 7440-66-6 T 1000 02L p /L 4.1 J+ 2.8 J+ 10 U 12 7.8 J+ 10 U 12 J+ 60 Total Dissolved Solids TDS N 500000 02L g/L 2130000 23000000 2100000 1500000 640000 101000 158000 187000 Total Organic Carbon TOC N - p /L 670 J 1000 U 1200 2900 1000 1000 U 1000 U 1000 U Total Suspended Solids TSS N pg/L 4100 J+ 7900 63000 5000 U 6800 2500 U 8300 18100 Alkalinity, CO3 ALK-0O3 N p /L 5000 U 5000 U 5000 U 560000 61500 5000 U 5000 U 5000 U Alkalinity, HCO3 ALK-HCO3 N pg/L 56000 36300 55000 5000 U 5000 UJ 50700 102000 17600 Alkalinity, lab ALK-LAB N - p /L 56000 36300 55000 1640000 J 574000 50700 102000 17600 Chloride 16887-00-6 N 250000 02L pg/L 7900 6100 6800 4800 3200 3200 2400 2900 Fluoride 16984-48-8 N - p /L - - - - - - - - Nitrogen, NO2 plus NO3 NO2-NO3 N - pg/L 40 26 20 U 20 U 20 U 110 120 20 U Sulfate 14808-79-8 N 250000 02L pg/L 1370000 1420000 1280000 6900 17600 4400 3300 84700 Sulfide 18496-25-8 N - pg/L 100 U 100 U 100 U 100 U 100 U 100 U 100 U 100 U Arsenic 7440-38-2 T 10 02L p /L - - - - - - Chromium 7440-47-3 T 10 02L pg/L - - Page 11 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: GWA-3D GWA-3SA GWA-3SA GWA-4113R GWA-46R GWA-4D GWA-4D GWA-4S Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 9/15/2015 7/1/2015 9/15/2015 7/27/2015 9/17/2015 7/10/2015 9/17/2015 7/10/2015 N N N N N N N N RV-GWA-3D-NS-3Q15 GWA-3SA RV-GWA-3SA-NS-3Q15 GWA-4113R RV-GWA-4BR-NS-3Q15 GWA-4D RV-GWA-4D-NS-3Q15 GWA-4S Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Iron 7439-89-6 T 300 02L N /L Manganese 7439-96-5 D /L Manganese 7439-96-5 T 50 02L I pg/L As III 7784-46-5 T /L As V 10103-60-3 T - N /L Chromium VI 18540-29-9 D 0.07 DHHS /L Chromium VI 18540-29-9 T 0.07 DHHS /L Fe II 1345-25-1 T - /L Fe III 1309-37-1 T /L Mn II 1344-43-0 T /L Mn IV 1313-13-9 T /L Se IV 10102-18-8 T /L Se VI 13410-01-0 T /L Uranium, Natural 7440-61-1 T /L Radium-226 13982-63-3 T Ci/L Radium-228 15262-20-1 T Ci/L Uranium-233 13968-55-3 T /L Uranium-234 13966-29-5 T /L Uranium-236 13982-70-2 T /L Dissolved Oxygen DO N m /L 1.04 0.25 0.24 3.2 0.36 3.81 Temperature TEMP N - - Deg C 24.1 20.8 28.6 20.8 19.1 17 H PH N 6.5 8.5 02L SU 6.87 5.94 5.97 12.5 12 7.4 Turbidity, field TURB N - - NTU 1.34 7.84 9.71 5.8 2.1 4.3 Specific Conductivity field SC NPS/cm 2509 2263 2647 12552 2638 210.8 Oxidation Reduction Potential ORP N mV -24.2 -43.4 -83.5 -58.2 91.7 211.6 GW Depth TOC GW DEPTH-TOCI N I I I I ft 32.51 32.27 - - Notes pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 12 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: GWA-4S GWA-5D GWA-5D GWA-5S GWA-6D GWA-6D GWA-6D GWA-6S Round 2 Round 1 Round 2 Round 1 Round 1 Round 1 Round 2 Round 1 9/17/2015 7/11/2015 9/16/2015 6/18/2015 6/19/2015 6/24/2015 9/18/2015 6/19/2015 N N N N N N N N RV-GWA-4S-NS-3Q15 GWA-5D RV-GWA-5D-NS-3Q15 GWA-5S GWA-6D GWA-6D RV-GWA-6D-NS-3Q15 GWA-6S Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D p /L 100 U 420 180 100 U 1000 1600 100 U Aluminum 7429-90-5 T pg/L 4300 460 1800 J+ 100 U 1400 2800 700 Antimony 7440-36-0 D p /L 0.5 U 0.5 U 0.5 U 0.5 U 0.25 J 4.3 0.5 U Antimony 7440-36-0 T 1 IMAC pg/L 0.5 U 0.5 U 0.5 U 0.5 U 0.25 J 3.4 0.5 U Arsenic 7440-38-2 D - p /L 0.5 U 1.1 0.89 0.5 U 1 0.59 0.17 J Arsenic 7440-38-2 T 10 02L pg/L 0.37 J 0.96 0.89 0.5 U 1 J+ 0.86 0.24 J+ Barium 7440-39-3 D - p /L 23 8.4 7 17 23 30 39 Barium 7440-39-3 T 700 02L pg/L 84 9.6 21 17 27 43 45 Ter Ilium 7440-41-7 D - pg/L 0.16 J 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Beryllium 7440-41-7 T 4 IMAC pg/L 0.54 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.079 J Boron 7440-42-8 D - pg/L 50 U 31 J+ 50 U 50 U 50 U 50 U 34 J+ Boron 7440-42-8 T 700 02L p /L 50 U 50 U 50 U 50 U 50 U 50 U 50 U Cadmium 7440-43-9 D - p /L 0.075 J 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.24 Cadmium 7440-43-9 T 2 02L pg/L 0.13 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.2 Calcium 7440-70-2 T - p /L 21900 28000 28600 915 47800 72600 1390 Chromium 7440-47-3 D - p /L 2.7 11.9 10.4 0.32 J+ 21 26.1 0.52 J+ Chromium 7440-47-3 T 10 02L p /L 6.6 24.5 11 0.57 J+ 24.8 35 1.7 J+ Cobalt 7440-48-4 D - pg/L 0.82 0.5 U 0.5 U 4.6 0.5 U 0.5 U 25.3 Cobalt 7440-48-4 T 1 IMAC p /L 3.6 0.21 J 1.1 4.5 0.3 J+ 0.34 J 27.6 Copper 7440-50-8 D - pg/L 1.1 0.67 J+ 5.3 1.4 J+ 1.3 J+ 1.7 6.2 J+ Copper 7440-50-8 T 1000 02L p /L 3.6 0.69 J 3.7 2.6 J+ 4.3 J+ 4.9 10.4 Iron 7439-89-6 D - pg/L 50 U 50 U 50 U 50 U 50 U 50 U 50 U Iron 7439-89-6 T 300 02L p /L 4500 86 1600 44 J+ 290 J+ 800 1100 Lead 7439-92-1 D - pg/L 0.16 0.056 J+ 0.77 0.1 U 0.1 UJ 0.1 0.1 U Lead 7439-92-1 T 15 02L pg/L 1.4 1.3 0.34 0.1 U 0.1 U 0.12 0.59 Magnesium 7439-95-4 T - pg/L 7100 453 777 278 185 290 795 Manganese 7439-96-5 D - p /L 130 5 U 5 U 200 5 U 5 U 1100 Manganese 7439-96-5 T 50 02L pg/L 240 5 U 120 190 6.8 19 1300 Mercury 7439-97-6 D - p /L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L pg/L 0.2 U 0.2 U 0.2 U 0.11 J+ 0.071 J+ 0.2 U 0.073 J+ Methane 74-82-8 N - p /L 1.4 J+ 1.3 J+ 2.1 J+ 2.4 J+ 1.7 J+ 2.2 J+ 2.1 J+ Molybdenum 7439-98-7 D pg/L 0.5 U 1.6 3.9 0.13 J 7.8 10.9 0.5 U Molybdenum 7439-98-7 T p /L 0.14 J 3 3.1 0.19 J 7.6 14.9 0.5 U Nickel 7440-02-0 D - pg/L 3.2 2.4 0.5 U 3.8 0.5 U 0.5 U 4.6 Nickel 7440-02-0 T 100 02L p /L 6.8 9.4 1.6 3.7 1.8 J+ 2.3 5.2 Potassium 7440-09-7 T - pg/L 5000 U 5000 U 5000 U 5000 U 3200 J 3460 J 5000 U Selenium 7782-49-2 D - p /L 0.3 J 0.5 U 0.34 J 0.5 U 0.56 0.51 0.5 U Selenium 7782-49-2 T 20 02L pg/L 0.54 0.5 U 0.36 J 0.5 U 0.56 0.57 0.5 U Sodium 7440-23-5 T - p /L 6530 9360 11000 5000 U 9870 9440 2960 J Strontium 7440-24-6 D pg/L 200 140 170 9.5 180 220 12 Strontium 7440-24-6 T pg/L 210 160 160 9.7 190 270 12 Thallium 7440-28-0 D - pg/L 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.041 J Thallium 7440-28-0 T 0.2 IMAC p /L 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.054 J Vanadium 7440-62-2 D - pg/L 1 U 13.9 19.2 1 U 26.9 20.8 1 U Vanadium 7440-62-2 T 0.3 IMAC p /L 6.5 13.9 17.6 1 U 28 22 4.8 Zinc 7440-66-6 D - pg/L 54 10 U 2.9 J 9.8 J+ 10 U 120 30 J+ Zinc 7440-66-6 T 1000 02L p /L 78 10 U 9.4 J 14 J+ 8.7 J+ 17 28 J+ Total Dissolved Solids TDS N 500000 02L g/L 166000 137000 107000 25000 U 184000 J+ 210000 31000 J+ Total Organic Carbon TOC N - p /L 1000 U 1000 U 1000 U 1000 U 1000 U 920 J 1300 Total Suspended Solids TSS N pg/L 305000 5600 U 73000 2500 U 15000 67200 5000 U Alkalinity, CO3 ALK-0O3 N p /L 5000 U 59600 59100 5000 U 47900 94800 5000 U Alkalinity, HCO3 ALK-HCO3 N pg/L 14300 16900 5000 U 2700 J 5000 U 5000 U 9800 Alkalinity, lab ALK-LAB N - p /L 14300 76500 70900 2700 J 129000 J- 175000 9800 Chloride 16887-00-6 N 250000 02L pg/L 3000 2100 2300 980 J 2400 3200 2900 Fluoride 16984-48-8 N - p /L - - - - - 150 - Nitrogen, NO2 plus NO3 NO2-NO3 N pg/L 20 U 21 19 J 20 U 20 U 20 U 23 Sulfate 14808-79-8 N 250000 02L pg/L 71200 5000 11400 1000 U 15500 14000 1200 Sulfide 18496-25-8 N - pg/L 100 U 100 U 100 U 100 U 100 U 100 U 100 U Arsenic 7440-38-2 T 10 02L p /L - - - - - - - Chromium 7440-47-3 T 10 02L pg/L Page 13 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: GWA-4S GWA-5D GWA-5D GWA-5S GWA-6D GWA-6D GWA-6D GWA-6S Round 2 Round 1 Round 2 Round 1 Round 1 Round 1 Round 2 Round 1 9/17/2015 7/11/2015 9/16/2015 6/18/2015 6/19/2015 6/24/2015 9/18/2015 6/19/2015 N N N N N N N N RV-GWA-4S-NS-3Q15 GWA-5D RV-GWA-5D-NS-3Q15 GWA-5S GWA-6D GWA-6D RV-GWA-6D-NS-3Q15 GWA-6S Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Iron 7439-89-6 T 300 02L N /L Manganese 7439-96-5 D /L Manganese 7439-96-5 T 50 02L I pg/L - As III 7784-46-5 T /L 0.2 U As V 10103-60-3 T - N /L 0.584 Chromium VI 18540-29-9 D 0.07 DHHS /L - Chromium VI 18540-29-9 T 0.07 DHHS /L 20.6 Fe II 1345-25-1 T - /L 20 U Fe III 1309-37-1 T /L 20 U Mn II 1344-43-0 T /L 5 U Mn IV 1313-13-9 T /L 5.24 Se IV 10102-18-8 T /L 0.5 U Se VI 13410-01-0 T /L 0.437 Uranium, Natural 7440-61-1 T /L - Radium-226 13982-63-3 T Ci/L Radium-228 15262-20-1 T Ci/L Uranium-233 13968-55-3 T /L Uranium-234 13966-29-5 T /L Uranium-236 13982-70-2 T /L - - - - - - Dissolved Oxygen DO N m /L 4.61 8.6 3.67 5.98 6.12 5.5 Temperature TEMP N - - Deg C 19.2 19.2 20.2 18.6 18.48 27.4 H PH N 6.5 8.5 02L SU 5.7 10.3 10.5 3.56 11.37 11.5 Turbidity, field TURB N - - NTU 6.9 2.01 57.9 1.92 3.98 22.5 Specific Conductivity field SC NPS/cm 214.6 215.6 185.5 184 532 528 Oxidation Reduction Potential ORP N mV 246.8 81.3 -15 4.2 -102.5 -22.2 GW Depth TOC GW DEPTH-TOCI N I I I ft - - 72.86 - - Notes pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 14 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: GWA-6S GWA-6S GWA-7BR GWA-713R GWA-7D GWA-7D GWA-7S GWA-8D Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 Round 1 6/25/2015 9/18/2015 7/7/2015 9/15/2015 6/17/2015 9/15/2015 6/19/2015 6/28/2015 N N N N N N N N GWA-6S RV-GWA-6S-NS-3Q15 GWA-7BR RV-GWA-7BR-NS-3Q15 GWA-7D RV-GWA-7D-NS-3Q15 GWA-7S GWA-8D Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D p /L 110 100 U 100 U 100 U 100 U 100 U 100 U Aluminum 7429-90-5 T pg/L 1800 120 100 U 430 100 U 1200 J+ 1200 Antimony 7440-36-0 D p /L - 0.25 J 0.5 U 0.5 U - 0.5 U 0.5 U Antimony 7440-36-0 T 1 IMAC pg/L 0.2 J 0.96 0.33 J 0.17 J 0.16 J 0.5 U 0.5 U Arsenic 7440-38-2 D - p /L - 0.23 J 0.15 J 0.46 J - 0.5 U 0.12 J Arsenic 7440-38-2 T 10 02L pg/L 0.44 J 0.29 J 0.2 J 0.48 J 0.55 0.2 J+ 0.5 U Barium 7440-39-3 D - p /L 53 11 3.6 J 8.3 7.8 21 4.1 J Barium 7440-39-3 T 700 02L pg/L 60 18 3.8 J 13 7.6 39 5.3 Ter Ilium 7440-41-7 D - pg/L - 0.2 U 0.2 U 0.2 U - 0.2 U 0.2 U Beryllium 7440-41-7 T 4 IMAC pg/L 0.088 J 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Boron 7440-42-8 D - pg/L 50 U 50 U 50 U 50 U 50 U 50 U 120 Boron 7440-42-8 T 700 02L p /L 50 U 50 U 50 U 50 U 50 U 50 U 110 Cadmium 7440-43-9 D - p /L - 0.08 U 0.08 U 0.08 U - 0.08 U 0.08 U Cadmium 7440-43-9 T 2 02L pg/L 0.18 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U Calcium 7440-70-2 T - p /L 1560 33600 37800 24500 20400 6540 14600 Chromium 7440-47-3 D - p /L - 7.8 3.3 2.1 - 2.3 J+ 2.5 J+ Chromium 7440-47-3 T 10 02L p /L 5.4 J+ 5.8 3.9 3.3 3.3 3.8 4.2 J+ Cobalt 7440-48-4 D - pg/L - 0.5 U 0.5 U 0.5 U - 0.31 J+ 0.16 J Cobalt 7440-48-4 T 1 IMAC p /L 27.1 0.5 U 0.5 U 0.63 0.79 1 J+ 0.7 Copper 7440-50-8 D - pg/L - 1.7 1.9 0.97 J - 0.31 J+ 7.5 J+ Copper 7440-50-8 T 1000 02L p /L 4.1 0.49 J 0.29 J 2.6 4.1 3.6 J+ 1.1 J+ Iron 7439-89-6 D - pg/L 41 J+ 50 U 50 U 50 U 50 U 50 U 50 U Iron 7439-89-6 T 300 02L p /L 2500 77 50 U 440 50 U 790 1300 Lead 7439-92-1 D - pg/L - 0.14 0.19 0.053 J - 0.1 U 0.76 Lead 7439-92-1 T 15 02L pg/L 0.79 0.14 0.1 U 0.35 0.2 0.26 0.072 J+ Magnesium 7439-95-4 T - pg/L 787 6240 14300 5480 5820 4360 9720 Manganese 7439-96-5 D - p /L 1300 5 U 5 U 5 U 9.2 16 69 Manganese 7439-96-5 T 50 02L pg/L 1400 4.2 J 20 J+ 28 9.4 J+ 30 96 Mercury 7439-97-6 D - p /L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L pg/L 0.2 U 0.2 U 0.2 U 0.13 J+ 0.2 U 0.075 J+ 0.2 U Methane 74-82-8 N - p /L 1.1 J+ 7.4 J+ 1.3 J+ 1.7 J+ 10 U 1.7 J+ 1.7 J+ Molybdenum 7439-98-7 D pg/L - 2.2 0.41 J 2.7 - 0.5 U 0.72 Molybdenum 7439-98-7 T p /L 0.5 U 2.2 0.92 2.5 1.4 0.5 U 0.68 J+ Nickel 7440-02-0 D - pg/L - 1.6 0.17 J 0.5 U - 1.2 J+ 0.72 J+ Nickel 7440-02-0 T 100 02L p /L 8.3 0.34 J 0.19 J 0.77 1.4 2.8 1.9 J+ Potassium 7440-09-7 T - pg/L 5000 U 4840 J 3620 J 5000 U 5000 U 5000 U 5000 U Selenium 7782-49-2 D - p /L - 0.61 0.5 U 0.24 J - 0.5 U 0.5 U Selenium 7782-49-2 T 20 02L pg/L 0.5 U 0.3 J 0.5 U 0.24 J 0.5 U 0.5 U 0.5 U Sodium 7440-23-5 T - p /L 2760 J 6940 6830 20200 9430 5000 U 4800 J Strontium 7440-24-6 D pg/L 13 160 140 180 150 46 80 Strontium 7440-24-6 T pg/L 14 170 150 190 160 48 84 Thallium 7440-28-0 D - pg/L - 0.017 J 0.1 U 0.032 J - 0.1 U 0.027 J Thallium 7440-28-0 T 0.2 IMAC p /L 0.047 J 0.1 U 0.1 U 0.018 J 0.1 U 0.1 U 0.1 U Vanadium 7440-62-2 D - pg/L - 10.9 11.6 11.6 - 1 UJ 5.5 Vanadium 7440-62-2 T 0.3 IMAC p /L 3.2 10.9 11.2 12.1 12.4 3.5 J+ 5.5 Zinc 7440-66-6 D - pg/L 140 6.5 J 11 10 U 10 U 5.2 J+ 6.6 J Zinc 7440-66-6 T 1000 02L p /L 120 15 14 J+ 7.3 J+ 7.7 J+ 5.2 J+ 12 J+ Total Dissolved Solids TDS N 500000 02L pg/L 29000 141000 114000 176000 127000 65000 J+ 128000 Total Organic Carbon TOC N - p /L 1000 U 1000 U 1000 U 800 J 1000 U 1000 U 1000 U Total Suspended Solids TSS N pg/L 514000 11200 81200 J 23000 665000 2500 U 119000 Alkalinity, CO3 ALK-0O3 N p /L 5000 U 14900 4000 J 5000 U 5000 U 5000 U 5000 U Alkalinity, HCO3 ALK-HCO3 N pg/L 9800 45400 60900 81000 78700 32700 45400 Alkalinity, lab ALK-LAB N - p /L 9800 60300 64900 81000 78700 32700 45400 Chloride 16887-00-6 N 250000 02L pg/L 2700 3000 3000 4400 3200 2600 6300 Fluoride 16984-48-8 N - p /L 55 J - - - - - - Nitrogen, NO2 plus NO3 NO2-NO3 N - pg/L 53 91 96 84 120 20 U 12 J+ Sulfate 14808-79-8 N 250000 02L pg/L 1100 21500 11100 32300 11100 530 J 23800 J+ Sulfide 18496-25-8 N - pg/L 100 U 100 U 100 U 100 U 100 U 100 U 100 U Arsenic 7440-38-2 T 10 02L p /L - - - - - Chromium 7440-47-3 T 10 02L pg/L - - Page 15 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: GWA-6S GWA-6S GWA-7BR GWA-713R GWA-7D GWA-7D GWA-7S GWA-8D Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 Round 1 6/25/2015 9/18/2015 7/7/2015 9/15/2015 6/17/2015 9/15/2015 6/19/2015 6/28/2015 N N N N N N N N GWA-6S RV-GWA-6S-NS-3Q15 GWA-713R RV-GWA-7BR-NS-3Q15 GWA-7D RV-GWA-7D-NS-3Q15 GWA-7S GWA-8D Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Iron 7439-89-6 T 300 02L N /L Manganese 7439-96-5 D /L Manganese 7439-96-5 T 50 02L I pg/L - As III 7784-46-5 T /L 0.2 U As V 10103-60-3 T - N /L 0.2 U Chromium VI 18540-29-9 D 0.07 DHHS /L - Chromium VI 18540-29-9 T 0.07 DHHS /L 0.102 Fe II 1345-25-1 T - /L 7.3 J- Fe III 1309-37-1 T /L 20 U Mn II 1344-43-0 T /L 1600 Mn IV 1313-13-9 T /L 200 Se IV 10102-18-8 T /L 0.5 U Se VI 13410-01-0 T /L 0.5 U Uranium, Natural 7440-61-1 T /L - Radium-226 13982-63-3 T Ci/L Radium-228 15262-20-1 T Ci/L Uranium-233 13968-55-3 T /L Uranium-234 13966-29-5 T /L Uranium-236 13982-70-2 T /L - - - - - - - Dissolved Oxygen DO N m /L 6.38 1.4 1.81 2.67 1.75 5.58 0.12 Temperature TEMP N Deg C 21.87 25.2 22.9 16.54 20.1 19.88 20.1 H PH N 6.5 8.5 02L SU 6.25 4.7 8.6 8.03 8.1 4.99 7.21 Turbidity, field TURB N - - NTU 85.2 43.6 8.45 3.9 41.72 3.12 5.23 Specific Conductivity field SC NPS/cm 83 35.1 144.4 231 161.4 61 166 Oxidation Reduction Potential ORP N mV 127.6 283.3 119.3 23.8 127.8 -111.8 38.7 GW Depth TOC GW DEPTH-TOC N I i - ft - - Notes pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 16 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: GWA-8D GWA-8S GWA-8S GWA-9BR GWA-9D GWA-9D GWA-9S GWA-9S Round 2 Round 1 Round 2 Round 1 Round 1 Round 2 Round 1 Round 2 9/18/2015 6/28/2015 9/18/2015 7/10/2015 7/1/2015 9/16/2015 6/30/2015 9/16/2015 N N N N N N N N RV-GWA-8D-NS-3Q15 GWA-8S RV-GWA-8S-NS-3Q15 GWA-9BR GWA-9D RV-GWA-9D-NS-3Q15 GWA-9S RV-GWA-9S-NS-3Q15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D p /L 100 U 100 U 100 U - 100 U 100 U 88 J 100 U Aluminum 7429-90-5 T pg/L 820 100 U 99 J 4000 450 340 160 100 Antimony 7440-36-0 D p /L 0.5 U 0.5 U 0.5 U - 0.5 UJ 0.5 UJ 0.5 UJ 0.5 UJ Antimony 7440-36-0 T 1 IMAC pg/L 0.5 U 0.5 U 0.5 U 4.5 0.5 UJ 0.5 U 0.5 UJ 0.5 U Arsenic 7440-38-2 D - p /L 0.5 U 0.18 J 0.5 U - 0.5 U 0.5 U 0.5 U 0.5 U Arsenic 7440-38-2 T 10 02L pg/L 0.5 U 0.5 U 0.5 U 10.7 0.13 J 0.5 U 0.5 U 0.5 U Barium 7440-39-3 D - p /L 3.4 J 120 87 - 7.3 6.6 28 26 Barium 7440-39-3 T 700 02L pg/L 3.7 J 130 83 3.7 J 9.4 9.4 30 29 Beryllium 7440-41-7 D - pg/L 0.2 U 0.073 J 0.1 J - 0.2 UJ 0.2 U 0.08 J 0.082 J Beryllium 7440-41-7 T 4 IMAC pg/L 0.2 U 0.2 U 0.14 J 0.2 U 0.2 UJ 0.2 U 0.078 J 0.081 J Boron 7440-42-8 D - pg/L 120 240 260 - 260 250 210 280 Boron 7440-42-8 T 700 02L p /L 120 240 240 210 260 J+ 260 200 290 Cadmium 7440-43-9 D - p /L 0.08 U 0.08 U 0.046 J - 0.08 U 0.08 U 0.08 U 0.08 U Cadmium 7440-43-9 T 2 02L pg/L 0.08 U 0.054 J 0.047 J 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U Calcium 7440-70-2 T - p /L 12400 2070 2530 17500 14100 10000 2170 1880 Chromium 7440-47-3 D - p /L 2 1.5 J+ 5.3 - 0.4 J+ 0.35 J 0.36 J+ 0.5 J Chromium 7440-47-3 T 10 02L p /L 2.8 J+ 6.4 J+ 5.7 J+ 40.6 0.39 J+ 0.65 J+ 0.32 J+ 0.38 J+ Cobalt 7440-48-4 D - pg/L 0.5 U 2 31.4 - 0.47 J+ 0.17 J 51 44.7 Cobalt 7440-48-4 T 1 IMAC p /L 0.28 J 66.8 33.8 0.75 0.58 0.31 J 50.1 45.9 Copper 7440-50-8 D - pg/L 0.39 J 5.8 J+ 8.2 - 1 UJ 0.4 J 2.7 J+ 2.2 Copper 7440-50-8 T 1000 02L p /L 0.58 J 11.2 J+ 7.6 27.7 2.5 J+ 2.2 1.4 J+ 0.74 J Iron 7439-89-6 D - pg/L 50 U 50 U 50 U - 80 29 J 26 J 50 U Iron 7439-89-6 T 300 02L p /L 820 58 130 450 270 220 170J+ 48J Lead 7439-92-1 D - pg/L 0.083 J 0.63 0.086 J - 0.1 UJ 0.15 0.13 J+ 0.22 Lead 7439-92-1 T 15 02L pg/L 0.1 U 0.1 U 0.1 U 0.84 0.074 J+ 0.052 J 0.14 0.12 Magnesium 7439-95-4 T - pg/L 9430 6390 6270 127 6390 5690 2760 2480 Manganese 7439-96-5 D - p /L 35 760 390 - 83 26 3000 2600 Manganese 7439-96-5 T 50 02L pg/L 50 720 390 13 90 31 2900 2700 Mercury 7439-97-6 D - p /L 0.2 U 0.2 U 0.2 U - 0.2 U 0.2 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L pg/L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.11 J 0.2 U Methane 74-82-8 N - p /L 0.63 J+ 1.6 J+ 1 J+ - 24.4 16.6 1.5 J+ 1.2 J+ Molybdenum 7439-98-7 D pg/L 0.22 J 0.5 U 0.5 U - 0.47 J+ 0.11 J 0.5 U 0.5 U Molybdenum 7439-98-7 T p /L 0.22 J 0.5 U 0.5 U 47.3 0.47 J+ 0.12 J 0.5 U 0.5 U Nickel 7440-02-0 D pg/L 0.41 J 1.1 J+ 20.3 - 0.82 J+ 0.31 J 2.1 2 Nickel 7440-02-0 T 100 02L p /L 0.76 J+ 21.1 19.6 11.1 0.71 0.5 J 2.1 1.9 Potassium 7440-09-7 T - pg/L 5000 U 4080 J 3020 J 162000 5000 U 5000 U 5000 U 5000 U Selenium 7782-49-2 D - p /L 0.5 U 0.27 J 0.5 U - 0.5 U 0.5 U 0.5 U 0.22 J Selenium 7782-49-2 T 20 02L pg/L 0.5 U 0.5 U 0.5 U 1.6 0.5 U 0.5 U 0.5 U 0.2 J Sodium 7440-23-5 T - p /L 4660J 6510 6400 133000 8250 7030 5970 6020 Strontium 7440-24-6 D pg/L 84 16 17 - 110 100 29 27 Strontium 7440-24-6 T pg/L 81 17 16 300 120 110 30 28 Thallium 7440-28-0 D - pg/L 0.1 U 0.1 U 0.026 J+ - 0.1 U 0.1 U 0.041 J 0.056 J Thallium 7440-28-0 T 0.2 IMAC p /L 0.1 U 0.031 J 0.019 J 0.1 U 0.1 U 0.016 J 0.04 J 0.056 J Vanadium 7440-62-2 D - pg/L 6.2 1 U 1 U - 2.3 3.2 0.42 J+ 1 U Vanadium 7440-62-2 T 0.3 IMAC p /L 7.2 1 U 1 U 67.5 2.8 4.6 0.52 J+ 1 U Zinc 7440-66-6 D - pg/L 12 J+ 32 46 - 10 UJ 11 5 J+ 12 Zinc 7440-66-6 T 1000 02L p /L 5 J 35 J+ 31 11 J+ 10 UJ 10 U 5.3 J+ 4.1 J+ Total Dissolved Solids TDS N 500000 02L g/L 128000 85000 87000 26000 107000 60000 58000 Total Organic Carbon TOC N - p /L 1000 U 1000 U 6700 1000 U 1000 U 8600 10800 Total Suspended Solids TSS N pg/L 9300 29000 5000 U 8500 10700 5600 4600 Alkalinity, CO3 ALK-0O3 N p /L 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U Alkalinity, HCO3 ALK-HCO3 N pg/L 39500 1200 J 5700 30600 23500 J+ 5000 U 5000 U Alkalinity, lab ALK-LAB N - p /L 39500 1200 J 5700 30600 23500 J+ 5000 U 5000 U Chloride 16887-00-6 N 250000 02L pg/L 6500 6200 6000 6700 6700 6800 6700 Fluoride 16984-48-8 N - p /L 64 J - 51 J - - - - Nitrogen, NO2 plus NO3 NO2-NO3 N - pg/L 20 U 600 690 13 J 20 U 140 280 Sulfate 14808-79-8 N 250000 02L pg/L 26600 36000 J+ 38500 33200 35500 26500 25500 Sulfide 18496-25-8 N pg/L 100 U 100 U 100 U 100 U 100 U 100 U 100 U Arsenic 7440-38-2 T 10 1 02L p /L - - - 0.487 - 0.312 - Chromium 7440-47-3 T 10 1 02L pg/L 0.822 J+ 0.445 J+ Page 17 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: GWA-8D GWA-8S GWA-8S GWA-9BR GWA-9D GWA-9D GWA-9S GWA-9S Round 2 Round 1 Round 2 Round 1 Round 1 Round 2 Round 1 Round 2 9/18/2015 6/28/2015 9/18/2015 7/10/2015 7/1/2015 9/16/2015 6/30/2015 9/16/2015 N N N N N N N N RV-GWA-8D-NS-3Q15 GWA-8S RV-GWA-8S-NS-3Q15 GWA-9BR GWA-9D RV-GWA-9D-NS-3Q15 GWA-9S RV-GWA-9S-NS-3Q15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Iron 7439-89-6 T 300 02L N /L 135 58.7 J+ Manganese 7439-96-5 D /L 78 3150 Manganese 7439-96-5 T 50 02L I pg/L 81.6 3040 As III 7784-46-5 T /L 0.5 UJ 0.5 UJ As V 10103-60-3 T - N /L 0.487 J 0.312 J Chromium VI 18540-29-9 D 0.07 DHHS /L 0.043 0.033 Chromium VI 18540-29-9 T 0.07 DHHS /L - - Fe II 1345-25-1 T /L 95 Fe III 1309-37-1 T /L - Mn II 1344-43-0 T /L Mn IV 1313-13-9 T /L - - Se IV 10102-18-8 T /L 3.62 J+ 2.27 J+ Se VI 13410-01-0 T /L 2 UJ 2 UJ Uranium, Natural 7440-61-1 T /L Radium-226 13982-63-3 T Ci/L Radium-228 15262-20-1 T Ci/L Uranium-233 13968-55-3 T /L Uranium-234 13966-29-5 T /L Uranium-236 13982-70-2 T /L - - - - - - Dissolved Oxygen DO N m /L 0.21 1.59 0.35 7.33 0.87 0.75 1.1 Temperature TEMP N - - Deg C 19 20.72 20.3 20.2 20.4 19.19 22.6 H PH N 6.5 8.5 02L SU 6.9 5.03 5.2 11.54 6.2 4.82 5 Turbidity, field TURB N - - NTU 6.5 1.86 5.9 137.3 7.04 7.93 8.04 Specific Conductivity field SC NPS/cm 1 310.9 122 238.7 1622 1 169.3 94 109.3 Oxidation Reduction Potential ORP N mV 1 76.1 242.3 191.3 129.1 1 - 98.3 264.3 229.1 GW Depth TOC GW DEPTH-TOC N ft 1 20.7 20.7 - - Notes pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 18 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: MW-10 MW-10 MW-11DR MW-11SR MW-13 MW-14 MW-15 MW-15 Round 1 Round 1 Round 1 Round 1 Round 1 Round 1 Round 1 Round 1 6/23/2015 6/29/2015 7/2/2015 7/2/2015 6/30/2015 6/30/2015 6/23/2015 6/29/2015 N N N N N N N N MW-10 MW-10 MW-11DR MW-11SR MW-13 MW-14 MW-15 MW-15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D p /L 100 U 100 U 100 U 100 U 100 U 100 U Aluminum 7429-90-5 T pg/L 210 78 J 100 U 100 U 100 U 120 Antimony 7440-36-0 D - p /L 0.5 U - 0.72 0.5 UJ 0.5 UJ 0.5 U Antimony 7440-36-0 T 1 IMAC pg/L 0.5 U 0.59 0.87 0.5 UJ 0.5 UJ 0.5 U Arsenic 7440-38-2 D - p /L 0.5 U - 0.5 U 0.36 J 0.5 U 0.5 U Arsenic 7440-38-2 T 10 02L pg/L 1 0.16 J 0.5 U 0.5 U 0.39 J 0.5 U 0.25 J Barium 7440-39-3 D - p /L 49 51 23 290 7.4 77 Barium 7440-39-3 T 700 02L pg/L 56 54 25 300 7.8 86 Ter Ilium 7440-41-7 D - pg/L 0.12 J - 0.2 U 0.2 U 0.2 U 0.15 J Beryllium 7440-41-7 T 4 IMAC pg/L 0.15 J 0.071 J 0.2 U 0.2 U 0.2 U 0.22 Boron 7440-42-8 D - pg/L 170 320 340 66 110 260 Boron 7440-42-8 T 700 02L p /L 180 320 360 60 130 280 Cadmium 7440-43-9 D - p /L 0.027 J - 0.08 U 0.08 U 0.08 U 0.028 J Cadmium 7440-43-9 T 2 02L pg/L 0.082 0.08 U 0.026 J 0.08 U 0.08 U 0.08 U Calcium 7440-70-2 T - p /L 4290 9150 9290 9340 6790 3930 Chromium 7440-47-3 D - p /L 2.1 J+ - 1.9 J 0.4 J+ 1.3 J+ 4.9 Chromium 7440-47-3 T 10 02L p /L 2.7 2.5 J 1.8 J 0.38 J+ 1.7 J+ 6.8 Cobalt 7440-48-4 D - pg/L 0.72 - 0.5 U 24.3 0.5 U 0.58 Cobalt 7440-48-4 T 1 IMAC p /L 0.9 0.5 UJ 0.5 U 23.7 0.5 U 1.3 Copper 7440-50-8 D - pg/L 0.44 J - 0.33 J+ 0.5 J+ 0.34 J+ 8 Copper 7440-50-8 T 1000 02L p /L 0.7 J 0.37 J+ 0.32 J+ 0.29 J+ 1 UJ 2.8 Iron 7439-89-6 D - pg/L 50 U 50 U 33 J 15000 50 U 50 U Iron 7439-89-6 T 300 02L p /L 220 62 46J 15700 28J+ 160 Lead 7439-92-1 D - pg/L 0.1 U - 0.047 J 0.1 UJ 0.1 UJ 0.72 Lead 7439-92-1 T 15 02L pg/L 0.15 0.081 J+ 0.1 UJ 0.1 U 0.1 U 0.6 Magnesium 7439-95-4 T - pg/L 2940 6350 5990 4670 16500 3110 Manganese 7439-96-5 D - p /L 30 6.3 29 8700 3.1 J 26 Manganese 7439-96-5 T 50 02L pg/L 36 9.1 32 8300 4J 33 Mercury 7439-97-6 D - p /L 0.1 J+ 0.2 U 0.2 U 0.2 U 0.2 U 0.1 J+ Mercury 7439-97-6 T 1 02L pg/L 0.081 J+ 0.2 U 0.2 U 0.072 J 0.2 U 0.078 J+ Methane 74-82-8 N - p /L 1.8 J+ 1.8 J+ 33 28.3 1.6 J+ 2 J+ Molybdenum 7439-98-7 D pg/L 0.5 U - 0.15 J 0.5 U 0.5 UJ 0.5 U Molybdenum 7439-98-7 T p /L 0.5 U 0.14 J 0.16 J 0.5 U 0.37 J 0.5 U Nickel 7440-02-0 D - pg/L 1 - 0.96 J+ 1.7 0.62 1.3 Nickel 7440-02-0 T 100 02L p /L 1 0.66 0.9 1.8 J+ 0.7 J+ 1.6 Potassium 7440-09-7 T - pg/L 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U Selenium 7782-49-2 D - p /L 0.44 J - 0.72 0.5 U 0.5 U 1.9 Selenium 7782-49-2 T 20 02L pg/L 0.53 0.72 0.71 0.5 U 0.5 U 2 Sodium 7440-23-5 T - p /L 6220 6770 7500 3120 J 2550 J 9240 Strontium 7440-24-6 D pg/L 63 80 140 79 33 63 Strontium 7440-24-6 T pg/L 70 84 150 82 35 70 Thallium 7440-28-0 D - pg/L 0.1 U - 0.1 U 0.076 J 0.1 U 0.1 U Thallium 7440-28-0 T 0.2 IMAC p /L - 0.1 U 0.1 U 0.072 J 0.1 U - Vanadium 7440-62-2 D - pg/L 0.46 J - 1.3 1 UJ 2.6 J+ 1 U Vanadium 7440-62-2 T 0.3 IMAC p /L 1.2 2.1 1.4 1 UJ 2.6 J+ 2.7 Zinc 7440-66-6 D - pg/L 3.1 J 5.3 J 2.7 J 10 UJ 10 UJ 5.4 J Zinc 7440-66-6 T 1000 02L p /L 4.1 J 5.8 J+ 4.1 J+ 10 UJ 10 UJ 6.7 J Total Dissolved Solids TDS N 500000 02L g/L 69000 J 140000 25000 U 87000 138000 227000 Total Organic Carbon TOC N - p /L 1000 U 8500 1000 U 790 J 1000 U 1000 U Total Suspended Solids TSS N pg/L 5000 U 16700 2500 U 5900 2500 U 20300 Alkalinity, CO3 ALK-0O3 N p /L 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U Alkalinity, HCO3 ALK-HCO3 N pg/L 5900 16100 14600 57900 45800 3100 J Alkalinity, lab ALK-LAB N - p /L 5900 16100 14600 57900 45800 3100 J Chloride 16887-00-6 N 250000 02L pg/L 6400 5900 6000 4200 13500 6000 Fluoride 16984-48-8 N - p /L - - - - - - Nitrogen, NO2 plus NO3 NO2-NO3 N - pg/L 47 J+ 320 250 20 U 71 49 J+ Sulfate 14808-79-8 N 250000 02L pg/L 19500 36000 37600 15700 30100 29000 Sulfide 18496-25-8 1 N pg/L 100 UJ - 100 U 100 U 100 U 100 U 100 U - Arsenic 1 7440-38-2 1 T I 1 10 1 02L I p /L - 0.273 J- - - 0.547 0.5 U - 0.322 J- Chromium 1 7440-47-3 1 T I 1 10 1 02L I pg/L 1.67 0.602 J+ 1.23 J+ 5.06 Page 19 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: MW-10 MW-10 MW-11DR MW-11SR MW-13 MW-14 MW-15 MW-15 Round 1 Round 1 Round 1 Round 1 Round 1 Round 1 Round 1 Round 1 6/23/2015 6/29/2015 7/2/2015 7/2/2015 6/30/2015 6/30/2015 6/23/2015 6/29/2015 N N N N N N N N MW-10 MW-10 MW-11DR MW-11SR MW-13 MW-14 MW-15 MW-15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Iron 7439-89-6 T 300 02L N /L 420 12000 18.1 J+ 216 J+ Manganese 7439-96-5 D /L 54.5 8950 2.92 17.3 Manganese 7439-96-5 T 50 02L I pg/L 41.3 - - 6930 3.72 J+ 19.2 As III 7784-46-5 T /L 0.5 UJ 0.2 U 0.2 U 0.404 J- 0.5 UJ 0.5 UJ As V 10103-60-3 T - N /L 0.273 J 0.2 U 0.2 U 0.5 U 0.5 U 0.322 J Chromium VI 18540-29-9 D 0.07 DHHS /L 0.2 - - 0.02 U 0.76 4.3 Chromium VI 18540-29-9 T 0.07 DHHS /L - 1.68 1.3 - - - Fe II 1345-25-1 T - /L 20 U 39.8 Fe III 1309-37-1 T /L 9.3 20 U Mn II 1344-43-0 T /L 8.6 32.2 Mn IV 1313-13-9 T /L - 5.52 1 U - - - Se IV 10102-18-8 T /L 3.73 J+ 0.5 U 0.5 U 5.05 J+ 2.51 J+ 8.53 J+ Se VI 13410-01-0 T /L 2 UJ 0.613 0.538 2 UJ 2 UJ 2.27 J+ Uranium, Natural 7440-61-1 T /L - - 0.2 U - Radium-226 13982-63-3 T Ci/L 1 U Radium-228 15262-20-1 T Ci/L 3 U Uranium-233 13968-55-3 T /L 0.05 U Uranium-234 13966-29-5 T /L 0.05 U Uranium-236 13982-70-2 T /L - - - 0.05 U - - Dissolved Oxygen DO N m /L 1.22 1.1 1.6 0.26 1.5 2.15 Temperature TEMP N - - Deg C 21.57 21.6 20.3 16.5 17.98 20.67 H PH N 6.5 8.5 02L SU 4.57 5.9 5.8 6.88 7.19 4.31 Turbidity, field TURB N - - NTU 4.88 8.8 8.1 0.95 1.97 3.6 Specific Conductivity field SC NPS/cm 108 156.9 161.5 170 181 165 Oxidation Reduction Potential ORP N mV -12.3 114.8 117.3 -15.7 58 127.8 GW Depth TOC GW DEPTH-TOC N ft - I - - - - Notes pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 20 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: MW-15BR MW-15BR MW-15D MW-15D MW-1D MW-1D MW-is MW-1S Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 6/23/2015 9/15/2015 6/18/2015 9/15/2015 6/29/2015 9/18/2015 6/29/2015 9/18/2015 N N N N N N N N MW-15BR RV-MW-I5BR-NS-3Q15 MW-15D RV-MW-15D-NS-3Q15 MW-1D RV-MW-1 D-NS-3Q1 5 MW-is RV-MW-1S-NS-3Q15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D p /L 160 290 880 190 100 U 100 U 100 U 100 U Aluminum 7429-90-5 T pg/L 250 360 930 770 100 U 100 U 100 U 100 U Antimony 7440-36-0 D - p /L 0.21 J 0.71 0.74 0.67 0.5 UJ 0.5 U 0.5 UJ 0.5 U Antimony 7440-36-0 T 1 IMAC pg/L 0.25 J 0.93 0.74 0.8 0.5 UJ 0.5 U 0.5 UJ 0.5 U Arsenic 7440-38-2 D - p /L 0.68 0.33 J 1.2 2.1 0.5 U 0.5 U 0.49 J 0.48 J Arsenic 7440-38-2 T 10 02L pg/L 0.78 0.42 J 1 2.1 0.5 U 0.5 U 0.5 U 0.6 Barium 7440-39-3 D - p /L 18 39 9 4.5 J 28 31 21 25 Barium 7440-39-3 T 700 02L pg/L 23 43 9.1 7.7 31 27 22 21 Ter Ilium 7440-41-7 D - pg/L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Beryllium 7440-41-7 T 4 IMAC pg/L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Boron 7440-42-8 D - pg/L 240 260 190 240 650 710 310 410 Boron 7440-42-8 T 700 02L p /L 260 230 170 230 650 600 300 330 Cadmium 7440-43-9 D - p /L 0.08 U 0.08 U 0.08 U 0.08 U 0.1 0.087 0.08 U 0.08 U Cadmium 7440-43-9 T 2 02L pg/L 0.08 U 0.08 U 0.08 U 0.08 U 0.12 0.091 0.08 U 0.08 U Calcium 7440-70-2 T - p /L 8160 17000 52700 32200 25300 25100 2010 2050 Chromium 7440-47-3 D - p /L 4.2 3.4 3.5 0.7 0.66 J+ 0.67 0.5 UJ 0.5 U Chromium 7440-47-3 T 10 02L p /L 4.9 4 J+ 3.5 1.4 J+ 0.8 J+ 1.1 J+ 0.57 J+ 0.91 J+ Cobalt 7440-48-4 D - pg/L 0.5 U 0.5 U 0.5 U 0.5 U 0.25 J 0.26 J 60.7 53.8 Cobalt 7440-48-4 T 1 IMAC p /L 0.5 U 0.5 U 0.5 U 0.47 J 0.51 0.31 J 61 58.6 Copper 7440-50-8 D - pg/L 0.52 J 0.44 J 2.3 J+ 0.46 J 0.9 J+ 0.73 J 1 UJ 1 U Copper 7440-50-8 T 1000 02L p /L 0.7 J 0.67 J 2.5 J+ 4.9 1.1 J+ 0.69 J 0.26 J+ 1 U Iron 7439-89-6 D - pg/L 50 U 50 U 50 U 50 U 50 U 50 U 30600 30500 Iron 7439-89-6 T 300 02L p /L 54 50 U 75J+ 430 74J+ 88 30800 29400 Lead 7439-92-1 D - pg/L 0.1 U 0.1 U 0.1 U 0.1 U 0.1 UJ 0.1 U 0.1 UJ 0.1 U Lead 7439-92-1 T 15 02L pg/L 0.066 J 0.048 J 0.059 J 0.22 0.064 J 0.1 U 0.064 J 0.1 U Magnesium 7439-95-4 T - pg/L 1080 311 899 3000 8250 7750 986 935 Manganese 7439-96-5 D - p /L 5 U 5 U 5 U 3.2 J 430 460 2600 2500 Manganese 7439-96-5 T 50 02L pg/L 4.4 J 5 U 3.3 J+ 16 530 380 2600 2100 Mercury 7439-97-6 D - p /L 0.095 J+ 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L pg/L 0.088 J+ 0.2 U 0.073 J 0.2 U 0.11 J 0.2 U 0.2 U 0.2 U Methane 74-82-8 N - p /L 2 J+ 2.6 J+ 2 J+ 2 J+ 2.5 J+ 3.4 J+ 101 99.8 J+ Molybdenum 7439-98-7 D pg/L 8A 8.9 11.3 5.9 0.16 J 0.17 J 0.18 J 0.16 J Molybdenum 7439-98-7 T p /L 8.2 8.9 10.7 5.9 0.5 U 0.19 J 0.12 J 0.15 J Nickel 7440-02-0 D - pg/L 0.5 U 0.29 J 0.51 J+ 0.26 J 5.1 4.5 0.41 J 1.7 Nickel 7440-02-0 T 100 02L p /L 0.21 J 0.38 J 0.28 J+ 0.5 J 5.6 4.9 0.56 J+ 0.56 Potassium 7440-09-7 T - pg/L 51300 54600 8700 3040 J 5000 U 5000 U 5000 U 5000 U Selenium 7782-49-2 D - p /L 0.63 0.59 1.1 1.2 0.27 J 0.23 J 0.5 U 0.5 U Selenium 7782-49-2 T 20 02L pg/L 0.57 0.88 1.1 1.2 0.28 J 0.25 J 0.5 U 0.5 U Sodium 7440-23-5 T - p /L 50100 60200 18300 13000 9730 8950 6090 5940 Strontium 7440-24-6 D pg/L 320 520 220 120 290 320 32 36 Strontium 7440-24-6 T pg/L 370 610 210 130 320 270 33 31 Thallium 7440-28-0 D - pg/L 0.1 U 0.1 U 0.1 U 0.1 U 0.061 J 0.055 J 0.1 U 0.1 U Thallium 7440-28-0 T 0.2 IMAC p /L - 0.1 U 0.1 U 0.1 U 0.034 J 0.047 J 0.1 U 0.1 U Vanadium 7440-62-2 D - pg/L 2.1 2.2 23.6 9.7 1.9 J+ 1.5 1 UJ 1 U Vanadium 7440-62-2 T 0.3 IMAC p /L 2.2 2.6 22.4 11 2.1 J+ 1.6 1 UJ 1 U Zinc 7440-66-6 D - pg/L 10 U 10 U 10 U 10 U 6.7 J+ 9.9 J 10 UJ 10 U Zinc 7440-66-6 T 1000 02L p /L 10 U 10 U 10 U 2.8 J 14 J+ 6.9 J 10 UJ 10 U Total Dissolved Solids TDS N 500000 02L g/L 232000 469000 241000 156000 197000 222000 60000 66000 Total Organic Carbon TOC N - p /L 1600 3000 640 J 1000 U 1000 U 1000 U 1000 U 14400 Total Suspended Solids TSS N pg/L 2500 U 9600 10600 J+ 37200 2500 U 2500 U 14800 32000 Alkalinity, CO3 ALK-0O3 N p /L 105000 54100 113000 5000 U 5000 U 5000 U 5000 U 5000 U Alkalinity, HCO3 ALK-HCO3 N pg/L 5000 U 5000 UJ 5000 U 3100 J+ 18900 18800 28200 21800 Alkalinity, lab ALK-LAB N - p /L 105000 217000 132000 3100 J+ 18900 18800 28200 J+ 21800 Chloride 16887-00-6 N 250000 02L pg/L 7500 8000 6200 6200 7900 7100 10700 9500 Fluoride 16984-48-8 N - p /L - - - - - - - - Nitrogen, NO2 plus NO3 NO2-NO3 N - pg/L 77 J+ 100 82 J+ 30 20 U 151 12 J 24 Sulfate 14808-79-8 N 250000 02L pg/L 39500 39400 40100 43600 86100 101000 1200 J- 820 J Sulfide 18496-25-8 N - pg/L 100 U 100 U 100 U 100 U 100 U 100 U 100 U 100 U Arsenic 7440-38-2 T 10 02L p /L - - - - 0.5 UJ - 0.269 J- - Chromium 7440-47-3 T 10 02L pg/L 0.905 J+ 0.294 J+ Page 21 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: MW-15BR MW-15BR MW-15D MW-15D MWAD MW-1D MWAS MwAs Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 6/23/2015 9/15/2015 6/18/2015 9/15/2015 6/29/2015 9/18/2015 6/29/2015 9/18/2015 N N N N N N N N MW-15BR RV-MW-15BR-NS-3Q15 MW-15D RV-MW-I5D-NS-3Q15 MWAD RV-MW-ID-NS-3Q15 MWAS RV-MW-IS-NS-3Q15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Iron 7439-89-6 T 300 02L N /L 122 J+ 22400 Manganese 7439-96-5 D /L 463 2780 Manganese 7439-96-5 T 50 02L I pg/L 504 2850 As III 7784-46-5 T /L 0262 J- 0.459 J- As V 10103-60-3 T - N /L 0.5 U 0.5 U Chromium VI 18540-29-9 D 0.07 DHHS /L 0.48 0.02 U Chromium VI 18540-29-9 T 0.07 DHHS /L - - Fe II 1345-25-1 T - /L Fe III 1309-37-1 T /L Mn II 1344-43-0 T /L Mn IV 1313-13-9 T /L - - Se IV 10102-18-8 T /L 4.91 J+ 6.47 J+ Se VI 13410-01-0 T /L 2 UJ 2 UJ Uranium, Natural 7440-61-1 T /L Radium-226 13982-63-3 T Ci/L Radium-228 15262-20-1 T Ci/L Uranium-233 13968-55-3 T /L Uranium-234 13966-29-5 T /L Uranium-236 13982-70-2 T /L - - - - - - - Dissolved Oxygen DO N m /L 2.23 0.66 0.57 0.21 0.4 0.16 0.4 Temperature TEMP N - - Deg C 18.63 23.8 22.1 21.09 25.7 19.82 26.1 H PH N 6.5 8.5 02L SU 11.21 11.9 10.3 6.08 6 6.66 6.5 Turbidity, field TURB N - - NTU 4.54 6.18 8.98 4.13 3.5 6.82 5.9 Specific Conductivity field SC NPS/cm 555 1964 194.2 287 284.7 1 159 1 181.5 Oxidation Reduction Potential ORP N mV -206 -98.4 37.2 87.8 -2.1 -92.6 -113.4 GW Depth TOC GW DEPTH -TOC N ft - 4.16 2.24 Notes pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 22 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: MW-21D MW-2D MW-3D MW-3D MW-3S MW-3S MW-41D MW-4D Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 6/30/2015 9/18/2015 6/30/2015 9/16/2015 6/30/2015 9/16/2015 6/18/2015 9/17/2015 N N N N N N N N MW-21D RV-MW-2D-NS-3Q15 MW-31D RV-MW-3D-NS-3Q15 MW-3S RV-MW-3S-NS-3Q15 MW-41D RV-MW-4D-NS-3Q15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D p /L 100 U 100 100 U 100 U 100 U 100 U 100 U 100 U Aluminum 7429-90-5 T pg/L 100 U 180 100 U 100 U 100 U 82 J 220 J+ 59 J Antimony 7440-36-0 D p /L 0.5 UJ 0.4 J 0.5 UJ 0.5 UJ 0.5 UJ 0.5 UJ 0.5 U 0.5 U Antimony 7440-36-0 T 1 IMAC pg/L 0.5 UJ 0.5 0.5 UJ 0.5 U 0.5 UJ 0.5 U 0.5 U 0.5 UJ Arsenic 7440-38-2 D - p /L 0.5 U 0.28 J 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U Arsenic 7440-38-2 T 10 02L pg/L 0.5 U 0.5 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.14 J Barium 7440-39-3 D - p /L 22 26 7.4 7.2 16 16 64 70 Barium 7440-39-3 T 700 02L pg/L 23 21 7.7 7.8 17 40 65 61 Ter Ilium 7440-41-7 D - pg/L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Beryllium 7440-41-7 T 4 IMAC pg/L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Boron 7440-42-8 D - pg/L 50 U 50 U 270 290 260 320 290 300 Boron 7440-42-8 T 700 02L p /L 50 U 50 U 260 270 260 310 270 270 Cadmium 7440-43-9 D - p /L 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U Cadmium 7440-43-9 T 2 02L pg/L 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U Calcium 7440-70-2 T - p /L 6950 6630 17100 17300 13800 14500 10900 10800 Chromium 7440-47-3 D - p /L 2.3 J+ 1.8 1.8 J+ 1.9 0.41 J+ 1.3 1.3 J+ 2.1 Chromium 7440-47-3 T 10 02L p /L 3.6 J+ 11.5 1.7 J+ 1.7 J+ 0.44 J+ 4.5 1.4 J+ 1 J+ Cobalt 7440-48-4 D - pg/L 0.5 U 0.2 J 0.5 U 0.5 U 0.5 U 0.17 J 0.57 0.46 J Cobalt 7440-48-4 T 1 IMAC p /L 0.14 J 1.3 0.5 U 0.5 U 0.14 J 2.6 0.67 0.52 Copper 7440-50-8 D - pg/L 0.63 J+ 0.87 J 6.9 J+ 2.8 8.9 J+ 8.8 1 A J+ 1.1 Copper 7440-50-8 T 1000 02L p /L 0.23 J+ 3.8 1 UJ 0.3 J 0.22 J+ 0.44 J 2.1 J+ 1 U Iron 7439-89-6 D - pg/L 50 U 70 50 U 50 U 50 U 50 U 50 U 50 U Iron 7439-89-6 T 300 02L p /L 72 J+ 270 44 J+ 50 U 140 J+ 720 230 J+ 85 Lead 7439-92-1 D - pg/L 0.072 J+ 0.1 U 0.68 J+ 0.3 0.88 J+ 0.94 0.1 U 0.069 J Lead 7439-92-1 T 15 02L pg/L 0.1 U 0.16 0.09 J 0.1 U 0.24 0.1 U 0.058 J 0.1 U Magnesium 7439-95-4 T - pg/L 4120 3830 8750 8600 8850 9130 3850 3550 Manganese 7439-96-5 D - p /L 7.7 11 5 U 5 U 53 450 22 J+ 22 Manganese 7439-96-5 T 50 02L pg/L 8.3 12 5 U 5 U 68 1700 24 J+ 20 Mercury 7439-97-6 D - p /L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L pg/L 0.2 U 0.2 U 0.088 J 0.2 U 0.2 U 0.2 U 0.15 J 0.2 U Methane 74-82-8 N - p /L 1.1 J+ 2.9 J+ 30.1 43 2 J+ 3.6 J+ 15.7 J+ 14.5 J+ Molybdenum 7439-98-7 D pg/L 0.1 J 0.17 J 0.098 J 0.11 J 0.5 U 0.5 U 0.5 U 0.5 U Molybdenum 7439-98-7 T p /L 0.12 J 0.29 J 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U Nickel 7440-02-0 D - pg/L 1.1 1.9 0.39 J 0.42 J 0.8 4.8 1.1 J+ 1.1 Nickel 7440-02-0 T 100 02L p /L 1.5 J+ 5.8 0.24 J+ 0.2 J 0.45 J+ 5.9 1.1 J+ 0.96 Potassium 7440-09-7 T - pg/L 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U Selenium 7782-49-2 D - p /L 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U Selenium 7782-49-2 T 20 02L pg/L 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U Sodium 7440-23-5 T - p /L 5930 5400 4040 J 3880 J 4160 J 4220 J 7750 7480 Strontium 7440-24-6 D pg/L 88 93 170 170 120 130 180 190 Strontium 7440-24-6 T pg/L 95 75 180 180 130 130 180 170 Thallium 7440-28-0 D - pg/L 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U Thallium 7440-28-0 T 0.2 IMAC p /L 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U Vanadium 7440-62-2 D - pg/L 4.5 4.1 5.8 5.6 0.54 J+ 0.42 J 1 U 0.58 J Vanadium 7440-62-2 T 0.3 IMAC p /L 4.7 6.6 6.2 5.7 0.6 J+ 0.45 J 1.1 0.58 J Zinc 7440-66-6 D - pg/L 9.9 J+ 17 10 UJ 10 U 10 UJ 3.7 J 3.3 J+ 3.4 J+ Zinc 7440-66-6 T 1000 02L p /L 8.8 J+ 14 10 UJ 10 U 10 UJ 10 U 6.3 J+ 5 J+ Total Dissolved Solids TDS N 500000 02L g/L 92000 88000 141000 146000 118000 131000 113000 99000 Total Organic Carbon TOC N - p /L 1000 U 1000 U 1000 U 1000 U 1000 U 1000 U 1000 U 1000 U Total Suspended Solids TSS N pg/L 20400 8000 2500 U 6200 U 2500 U 6900 8400 J+ 2500 U Alkalinity, CO3 ALK-0O3 N p /L 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U Alkalinity, HCO3 ALK-HCO3 N pg/L 40700 39400 53200 53100 43400 60600 17000 15600 Alkalinity, lab ALK-LAB N - p /L 40700 J- 39400 53200 53100 43400 60600 17000 15600 Chloride 16887-00-6 N 250000 02L pg/L 4600 3600 6600 6500 7100 6800 5400 5700 Fluoride 16984-48-8 N - p /L - 62 J - - - - - - Nitrogen, NO2 plus NO3 NO2-NO3 N - pg/L 20 U 38 32 66 20 U 57 18 J+ 40 Sulfate 14808-79-8 N 250000 02L pg/L 720 J 610 J 26700 27200 29900 30900 30900 32700 Sulfide 18496-25-8 N pg/L 100 U 100 U 100 U 100 U 100 U 100 U 100 U 100 U Arsenic 7440-38-2 T 10 1 02L p /L - - - - - - - - Chromium 7440-47-3 T 10 1 02L pg/L Page 23 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: MW-2D MW-2D MW-3D MW-3D MW-3S MW-3S MW-4D MW-4D Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 6/30/2015 9/18/2015 6/30/2015 9/16/2015 6/30/2015 9/16/2015 6/18/2015 9/17/2015 N N N N N N N N MW-2D RV-MW-2D-NS-3Q15 MW-3D RV-MW-3D-NS-3Q15 MW-3S RV-MW-3S-NS-3Q15 MW-4D RV-MW-4D-NS-3Q15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Iron 7439-89-6 T 300 02L N /L Manganese 7439-96-5 D /L Manganese 7439-96-5 T 50 02L I pg/L As III 7784-46-5 T /L As V 10103-60-3 T - N /L Chromium VI 18540-29-9 D 0.07 DHHS /L Chromium VI 18540-29-9 T 0.07 DHHS /L Fe II 1345-25-1 T /L Fe III 1309-37-1 T /L Mn II 1344-43-0 T /L Mn IV 1313-13-9 T /L Se IV 10102-18-8 T /L Se VI 13410-01-0 T /L Uranium, Natural 7440-61-1 T /L Radium-226 13982-63-3 T Ci/L Radium-228 15262-20-1 T Ci/L Uranium-233 13968-55-3 T /L Uranium-234 13966-29-5 T /L Uranium-236 13982-70-2 T /L - - - - - - - - Dissolved Oxygen DO N m /L 0.55 1.09 0.1 0.4 4.06 1.73 0.61 0.51 Temperature TEMP N - - Deg C 19.34 17.7 18.83 18.8 17.61 22.1 15.94 14.6 H PH N 6.5 8.5 02L SU 6.35 6.29 6.73 6.7 6.04 6.3 4.59 5.71 Turbidity, field TURB N - - NTU 5.36 7.46 2.8 0.81 5.06 6.91 4.52 2.6 Specific Conductivity field SC NPS/cm 93 97.2 182 210.1 1 169 205.9 88 130 Oxidation Reduction Potential ORP N mV 9.6 104.7 114.9 206 150.2 202.2 85.5 228 GW Depth TOC GW DEPTH-TOC N ft 22.16 Notes pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 24 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: MW-4S MW-5D MW-5D MW-5S MW-5S MW-6D MW-61D MW-6S Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 9/17/2015 6/18/2015 9/17/2015 6/25/2015 9/17/2015 6/18/2015 9/18/2015 6/18/2015 N N N N N N N N RV-MW-4S-NS-3Q15 MW-5D RV-MW-5D-NS-3Q15 MW-5S RV-MW-5S-NS-3Q15 MW-6D RV-MW-6D-NS-3Q15 MW-6S Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D /L 100 U 100 U 100 U 100 U 100 U 100 U 100 U 100 U Aluminum 7429-90-5 T /L 920 180 J+ 100 U 100 U 100 U 71 J+ 100 U 81 J+ Antimony 7440-36-0 D I pg/L 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U Antimony 7440-36-0 T 1 IMAC /L 0.5 U 0.5 U 0.5 UJ 0.5 U 0.5 UJ 0.5 U 0.5 U 0.5 U Arsenic 7440-38-2 D /L 0.5 U 0.12 J 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U Arsenic 7440-38-2 T 10 El- wqlL 1 0.21 J 0.5 U 0.13 J 0.5 U 0.16 J 0.5 U 0.5 U 0.5 U Barium 7440-39-3 D /L 21 32 34 21 27 7.1 7.7 8.3 Barium 7440-39-3 T 700 02L /L 28 32 30 22 24 7.4 6.5 8.4 Beryllium 7440-41-7 D /L 0.12 J 0.2 U 0.2 U 0.084 J 0.088 J 0.2 U 0.2 U 0.2 U Beryllium 7440-41-7 T 4 IMAC /L 0.25 0.2 U 0.2 U 0.072 J 0.2 U 0.2 U 0.2 U 0.2 U Boron 7440-42-8 D /L 370 400 470 320 470 340 370 240 Boron 7440-42-8 T 700 02L wq1L 1 320 380 420 330 430 320 310 230 Cadmium 7440-43-9 D /L 0.049 J 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U Cadmium 7440-43-9 T 2 02L /L 0.025 J 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U Calcium 7440-70-2 T /L 5440 J- 24300 24200 889 918 14000 13500 J- 11100 Chromium 7440-47-3 D /L 1.8 2.4 J+ 2 1.6 2.2 1.1 J+ 0.27 J 0.36 J+ Chromium 7440-47-3 T 10 02L /L 3.3 J+ 2.7 J+ 1.9 J+ 1.7 2.1 J+ 1.9 J+ 0.43 J+ 0.5 UJ Cobalt 7440-48-4 D /L 15.4 0.5 U 0.5 U 2.2 1.6 0.5 U 0.5 U 0.21 J Cobalt 7440-48-4 T 1 IMAC /L 19 0.24 J 0.5 U 1 0.5 U 0.5 U 0.2 J Copper 7440-50-8 D /L 12.7 1.5 J+ 1 U 6.1 0.41 J 0.46 J+ 0.33 J 1.1 J+ Copper 7440-50-8 T 1000 02L /L 1 4.2 J+ 1 U 0.32 J 0.23 J 1.2 J+ 0.73 J 1 U Iron 7439-89-6 D /L 260 J+ 50 U 50 U 50 U 50 U 50 U 50 U 71 J+ Iron 7439-89-6 T 300 02L /L 990 200 J+ 50 U 50 U 32 J 93 J+ 38 J 250 J+ Lead 7439-92-1 D /L 1.5 0.1 U 0.1 U 0.73 0.088 J 0.1 U 0.058 J 0.1 U Lead 7439-92-1 T 15 02L /L 1 0.082 J 0.1 U 0.062 J 0.051 J 0.051 J 0.1 U 0.051 J Magnesium 7439-95-4 T /L 4550 12900 12300 845 877 6950 6210 6740 Manganese 7439-96-5 D /L 280 3 J+ 4 J 49 30 7.2 J+ 7.3 43 Manganese 7439-96-5 T 50 02L /L 240 8.1 J+ 4 J 39 32 8.4 J+ 6.6 44 Mercury 7439-97-6 D /L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L /L 0.2 U 0.095 J+ 0.2 U 0.26 0.16 J 0.2 UJ 0.2 U 0.2 U Methane 74-82-8 N /L 1.4 J+ 2.1 J+ 10.5 J+ 1.5 J+ 1.8 J+ 21.2 J+ 22 J+ 52.3 J Molybdenum 7439-98-7 D /L 0.5 U 0.22 J 0.16 J 0.5 U 0.5 U 0.27 J 0.15 J 0.5 U Molybdenum 7439-98-7 T WqIL 0.5 U 0.24 J 0.18 J 0.5 U 0.5 U 0.18 J 0.13 J 0.5 U Nickel 7440-02-0 D - /L 2 0.32 J+ 0.29 J 1.1 1.2 0.85 J+ 0.19 J 0.68 J+ Nickel 7440-02-0 T - 100 02L /L 3 0.54 J+ 0.3 J 0.74 1.2 0.9 J+ 0.2 J 0.2 J+ Potassium 7440-09-7 T - /L 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U Selenium 7782-49-2 D - /L 0.5 U 0.5 U 0.5 U 0.29 J 0.28 J 0.5 U 0.5 U 0.5 U Selenium 7782-49-2 T - 20 02L /L 0.5 U 0.5 U 0.5 U 0.29 J 0.21 J 0.5 U 0.5 U 0.5 U Sodium 7440-23-5 T - /L 9950 8170 8260 10700 11200 6670 6340 7310 Strontium 7440-24-6 D - /L 50 270 280 20 23 120 130 120 Strontium 7440-24-6 T - /L 48 260 260 21 22 120 110 120 Thallium 7440-28-0 D - /L 0.063 J 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U Thallium 7440-28-0 T - 0.2 IMAC /L 0.024 J 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U Vanadium 7440-62-2 D - /L 1 U 8.5 7.5 0.53 J 1 U 3.7 3.4 0.3 J Vanadium 7440-62-2 T - 0.3 IMAC /L 1.5 &s, 7.4 1 U 1 U 3.tI; 3.7 0.35 J Zinc 7440-66-6 D - /L 37 6.8 J+ 4.4 J+ 13 5.1 J+ 10 U IOU 10 U Zinc 7440-66-6 T - 1000 02L /L 12 8.6 J+ 7.3 J+ 3.3 J 4.3 J+ 10 UJ 10 U 10 U Total Dissolved Solids TDS N - 500000 02L wqlL 111000 186000 184000 58000 58000 129000 115000 121000 Total Organic Carbon TOC N - /L 910 J 15300 1000 U 14700 1000 U 1000 U 1000 U 1000 U Total Suspended Solids TSS N - /L 96800 2500 U 2500 U 2500 U 2500 U 4600 J+ 2500 U 12300 J+ Alkalinity, CO3 ALK-0O3 N - /L 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U 5000 U Alkalinity, HCO3 ALK-HCO3 N - /L 13700 73800 70400 6000 4400 J 31000 29800 21300 Alkalinity, lab ALK-LAB N - /L 13700 73800 70400 6000 4400 J 31000 29800 21300 Chloride 16887-00-6 N - 250000 02L wnIL 7200 6500 6600 7000 7600 6600 7000 6600 Fluoride 16984-48-8 N - /L 68 J - - - - - 66 J - Nitro en, NO2 plus NO3 NO2-NO3 N - /L 120 140 J+ 150 54 48 20 U 20 U 20 U Sulfate 14808-79-8 N - 250000 02L /L 32700 44600 44600 10200 12900 34600 36800 36700 Sulfide 18496-25-8 N - /L - 100 U 100 U 100 U 100 U 100 U - 100 U Arsenic 7440-38-2 T - 10 02L /L - - - - - - Chromium 7440-47-3 T - 10 02L /L - - Page 25 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: MW-4S MW-5D MW-5D MW-5S MW-5S MW-6D MW-6D MW-6S Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 Round 2 Round 1 9/17/2015 6/18/2015 9/17/2015 6/25/2015 9/17/2015 6/18/2015 9/18/2015 6/18/2015 N N N N N N N N RV-MW-4S-NS-3Q15 MW-5D RV-MW-5D-NS-3Q15 MW-5S RV-MW-5S-NS-3Q15 MW-6D RV-MW-6D-NS-3Q15 MW-6S Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Iron 7439-89-6 T 300 02L N /L Manganese 7439-96-5 D /L Manganese 7439-96-5 T 50 02L I pg/L As III 7784-46-5 T /L As V 10103-60-3 T - N /L Chromium VI 18540-29-9 D 0.07 DHHS /L Chromium VI 18540-29-9 T 0.07 DHHS /L Fe II 1345-25-1 T - /L Fe III 1309-37-1 T /L Mn II 1344-43-0 T /L Mn IV 1313-13-9 T /L Se IV 10102-18-8 T /L Se VI 13410-01-0 T /L Uranium, Natural 7440-61-1 T /L Radium-226 13982-63-3 T Ci/L Radium-228 15262-20-1 T Ci/L Uranium-233 13968-55-3 T /L Uranium-234 13966-29-5 T /L Uranium-236 13982-70-2 T /L - - - - - - Dissolved Oxygen DO N m /L 2.71 0.81 0.7 1.99 - 0.6 0.03 Temperature TEMP N - - Deg C 16.4 17.64 19.3 17.87 19.8 18 18.95 H PH N 6.5 8.5 02L SU 5.7 6.34 6.57 5.93 5.05 6.32 6.37 Turbidity, field TURB N - - NTU 648 1.82 1.4 3.68 0.7 2.5 5.57 Specific Conductivity field SC NPS/cm 71 257 258 100 73 165 162 Oxidation Reduction Potential ORP N mV 158 46.7 67 -77.8 - 69.5 16 GW Depth TOC GW DEPTH-TOC N I I I I ft 19.81 5.78 1 - 7.91 1.4 Notes pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 26 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: MW-6S MW-8D MW-81 MW-8S MW-9 MW-9BR MW-913R MW-9D Round 2 Round 1 Round 1 Round 1 Round 1 Round 1 Round 2 Round 1 9/17/2015 7/1/2015 7/1/2015 6/30/2015 7/6/2015 7/2/2015 9/18/2015 7/1/2015 N N N N N N N N RV-MW-6S-NS-3Q15 MW-8D MW-81 MW-8S MW-9 MW-9BR RV-MW-9BR-NS-3Q15 MW-9D Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D p /L 100 U 100 U 100 U 100 U 100 U 150 100 U 930 Aluminum 7429-90-5 T pg/L 100 U 2500 1600 170 160 370 110 1000 Antimony 7440-36-0 D p /L 0.5 U 0.5 UJ 0.5 UJ 0.4 J+ 0.5 U 1.3 2.5 16.8 Antimony 7440-36-0 T 1 IMAC pg/L 0.21 J+ 0.21 J+ 0.5 UJ 0.83 J+ 0.5 U 2.3 3.2 5.4 Arsenic 7440-38-2 D - p /L 0.5 U 0.12 J 0.5 U 0.5 U 0.12 J 0.52 0.36 J 0.28 J Arsenic 7440-38-2 T 10 02L pg/L 0.12 J 0.32 J 0.12 J 0.5 U 0.18 J 0.69 0.38 J 0.38 J Barium 7440-39-3 D - p /L 9.2 21 27 52 57 20 39 20 Barium 7440-39-3 T 700 02L pg/L 9.6 43 42 57 58 21 36 21 Ter Ilium 7440-41-7 D - pg/L 0.2 U 0.11 J+ 0.2 UJ 0.095 J 0.2 U 0.2 U 0.2 U 0.2 UJ Beryllium 7440-41-7 T 4 IMAC pg/L 0.2 U 0.12 J+ 0.24 J+ 0.089 J 0.2 U 0.2 U 0.2 U 0.2 UJ Boron 7440-42-8 D - pg/L 260 50 U 50 U 50 U 37 J 50 U 50 U 50 U Boron 7440-42-8 T 700 02L p /L 240 50 UJ 50 U 50 U 36 J 50 U 50 U 50 UJ Cadmium 7440-43-9 D - p /L 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U 0.08 U Cadmium 7440-43-9 T 2 02L pg/L 0.08 U 0.08 U 0.08 U 0.036 J 0.08 U 0.08 U 0.08 U 0.08 U Calcium 7440-70-2 T - p /L 10900 5760 2960 J+ 345 12400 56200 49400 J- 72600 J- Chromium 7440-47-3 D - p /L 0.31 J 0.77 J+ 0.71 J+ 0.42 J+ 1 J+ 5 3.2 24.8 Chromium 7440-47-3 T 10 02L I p /L 0.48 J+ 4.1 1.3 J+ 0.71 J+ 1.2 4 J 2.7 J+ 20.6 Cobalt 7440-48-4 D - pg/L 0.16 J 0.5 UJ 0.5 UJ 0.2 J 0.67 0.5 U 0.5 U 0.5 UJ Cobalt 7440-48-4 T 1 IMAC p /L 0.19 J 1.1 0.76 0.23 J 0.87 0.5 U 0.5 U 0.5 U Copper 7440-50-8 D - pg/L 0.3 J 7 J+ 1.6 J+ 0.95 J+ 1.2 0.9 J+ 0.42 J 0.98 J+ Copper 7440-50-8 T 1000 02L p /L 1 U 24.5 J+ 68 J+ 0.41 J+ 0.48 J 1.6 J+ 0.54 J 1.2 J+ Iron 7439-89-6 D - pg/L 110 50 U 50 U 50 U 50 U 50 U 50 U 50 U Iron 7439-89-6 T 300 02L p /L 160 2700 2100 85 J+ 220 180 50 U 50 UJ Lead 7439-92-1 D - pg/L 0.1 U 0.095 J+ 0.093 J+ 0.061 J+ 0.18 0.057 J 0.19 0.1 UJ Lead 7439-92-1 T 15 02L pg/L 0.1 U 0.73 J+ 0.28 J+ 0.076 J 0.21 0.33 J+ 0.05 J 0.1 UJ Magnesium 7439-95-4 T - pg/L 6470 1320 920 246 3650 3230 2990 955 Manganese 7439-96-5 D - p /L 47 3.5 J 2.8 J 54 4.6 J 5 U 5 U 5 U Manganese 7439-96-5 T 50 02L pg/L 44 40 39 57 7 7.5 2.5 J 5 U Mercury 7439-97-6 D - p /L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L pg/L 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U Methane 74-82-8 N - p /L 56.8 J+ 1.5 J+ 2.6 J+ 1 J+ 10 U 10 UJ 1.2 J+ 1.7 J+ Molybdenum 7439-98-7 D pg/L 0.5 U 1.8 J+ 0.5 UJ 0.5 U 0.14 J 4.1 2.9 6.4 J+ Molybdenum 7439-98-7 T p /L 0.5 U 2.3 J+ 3.2 J+ 0.5 U 0.14 J 3.4 3.1 6 J+ Nickel 7440-02-0 D - pg/L 0.5 U 0.92 J+ 0.38 J+ 0.69 0.85 0.2 J+ 0.51 0.5 UJ Nickel 7440-02-0 T 100 02L p /L 0.5 U 2.4 1 0.84 J+ 1 0.73 0.23 J 0.18 J Potassium 7440-09-7 T - pg/L 5000 U 5000 U 5000 U 5000 U 5000 U 3910 J 4550 J 4260 J Selenium 7782-49-2 D - p /L 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.35 J Selenium 7782-49-2 T 20 02L pg/L 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 0.22 J 0.22 J 0.38 J Sodium 7440-23-5 T - p /L 7460 10000 7580 5000 U 10900 11600 11400 16800 Strontium 7440-24-6 D pg/L 120 88 54 9 190 180 240 300 Strontium 7440-24-6 T pg/L 110 100 64 9.6 190 160 210 300 Thallium 7440-28-0 D - pg/L 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U Thallium 7440-28-0 T 0.2 IMAC p /L 0.1 U 0.1 U 0.02 J 0.033 J 0.1 U 0.017 J 0.1 U 0.1 U Vanadium 7440-62-2 D - pg/L 0.37 J 1.2 0.94 J 0.45 J+ 2.1 J+ 7.8 3.9 11.7 Vanadium 7440-62-2 T 0.3 IMAC p /L 0.34 J 4.1 2.8 0.32 J+ 2.7 7.8 4 12.5 Zinc 7440-66-6 D - pg/L 5.2 J+ 27 J+ 7.6 J+ 4.3 J+ 10 UJ 10 U 3.4 J+ 10 UJ Zinc 7440-66-6 T 1000 02L p /L 5.3 J+ 17 J+ 49 J+ 5.9 J+ 10 UJ 9.4 J 10 U 10 UJ Total Dissolved Solids TDS N 500000 02L g/L 103000 111000 77000 25000 U 114000 107000 99000 223000 Total Organic Carbon TOC N - p /L 1000 U 1000 U 1000 U 1000 U 1000 U 570 J 1000 U 1000 U Total Suspended Solids TSS N pg/L 2500 U 29600 35200 42300 4700 88000 77900 10400 Alkalinity, CO3 ALK-0O3 N p /L 5000 U 5000 U 5000 U 5000 U 5000 U 55200 35400 5000 U Alkalinity, HCO3 ALK-HCO3 N pg/L 20100 32800 21800 1100 J 42400 65200 49500 240000 Alkalinity, lab ALK-LAB N - p /L 20100 32800 21800 1100 J 42400 120000 J+ 84900 240000 Chloride 16887-00-6 N 250000 02L pg/L 6700 1200 1000 UJ 7000 2200 6300 2900 2700 Fluoride 16984-48-8 N - p /L - - - - - - 110 - Nitrogen, NO2 plus NO3 NO2-NO3 N - pg/L 20 U 41 24 20 U 35 250 260 460 Sulfate 14808-79-8 N 250000 02L pg/L 38700 1000 U 1000 U 580 J 24600 18000 17800 27000 Sulfide 18496-25-8 N - pg/L 100 U 100 U 100 UJ 100 U 100 U 100 U - 100 U Arsenic 7440-38-2 T 1 10 02L p /L - 0.5 U 0.5 U 0.189 0.324 J+ - 0.5 U Chromium 7440-47-3 T 1 10 02L pg/L 3.38 1.78 J+ 0.402 J+ 2.61 29.6 Page 27 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: MW-6S MW-8D MW-81 MW-8S MW-9 MW-913R MW-9BR MW-9D Round 2 Round 1 Round 1 Round 1 Round 1 Round 1 Round 2 Round 1 9/17/2015 7/1/2015 7/1/2015 6/30/2015 7/6/2015 7/2/2015 9/18/2015 7/1/2015 N N N N N N N N RV-MW-6S-NS-3Q15 MW-8D MW-81 MW-8S MW-9 MW-913R RV-MW-9BR-NS-3Q15 MW-9D Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Iron 7439-89-6 T 300 02L N /L 1530 802 16.2 J+ 108 92.9 J Manganese 7439-96-5 D /L 22.5 3.65 51.7 5.94 0.138 J Manganese 7439-96-5 T 50 02L I pg/L 41.2 J+ 31 J+ 42.7 8.03 J+ - 3.19 J+ As III 7784-46-5 T /L 0.5 UJ 0.5 UJ 0.5 UJ 0.227 J 0.2 U 0.5 UJ As V 10103-60-3 T - N /L 0.5 U 0.5 U 0.189 J 0.5 UJ 0.829 0.5 U Chromium VI 18540-29-9 D 0.07 DHHS /L 0.5 0.024 0.25 0.54 - 28 Chromium VI 18540-29-9 T 0.07 DHHS /L - - - - 4.2 - Fe II 1345-25-1 T - /L 101 40 U 30 UJ 28.1 40 U Fe III 1309-37-1 T /L - - 6.8 - Mn II 1344-43-0 T /L 5 U Mn IV 1313-13-9 T /L - 5.62 - Se IV 10102-18-8 T pa/L 2 UJ 2 UJ 1.69 J+ 2 U 0.5 U 1.31 J+ Se VI 13410-01-0 T /L 2 UJ 2 UJ 2 UJ 2 UJ 0.5 U 2 UJ Uranium, Natural 7440-61-1 T /L - Radium-226 13982-63-3 T Ci/L Radium-228 15262-20-1 T Ci/L Uranium-233 13968-55-3 T /L Uranium-234 13966-29-5 T /L Uranium-236 13982-70-2 T /L - - - - - - - - Dissolved Oxygen DO N m /L 0.22 7.02 7.39 7.35 1.78 4.6 2.9 2.16 Temperature TEMP N - - Deq C 19.8 17.2 17.18 18.5 27.3 19.2 17.8 18.85 H PH N 6.5 8.5 02L SU 6.25 6.37 5.68 6.1 6.1 11.4 10.11 11.49 Turbidity, field TURB N - - NTU 3.9 84.3 34.1 8.45 8.43 1.7 3.8 7.06 Specific Conductivity field SC N LSICM 154 102 68 30 128.3 728 271 1037 Oxidation Reduction Potential ORP N mV 38 -45.3 -43.6 -83.1 207.4 -12 56 18.9 GW Depth TOC GW DEPTH-TOCI N I ft 3.81 - - 5.98 Notes pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Page 28 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results - Round 1 and Round 2 Location: Event: Sample Date: Sample Type Code: Sample Name/ID: MW-9D MW-9D MW-9D Round 1 Round 1 Round 2 7/2/2015 7/2/2015 9/18/2015 N N N MW-9D MW-9D RV-MW-9D-NS-3Q15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Aluminum 7429-90-5 D p /L 1100 600 Aluminum 7429-90-5 T pg/L 1300 470 Antimony 7440-36-0 D - p /L 2.6 1.7 Antimony 7440-36-0 T 1 IMAC pg/L 2.7 1.1 Arsenic 7440-38-2 D - p /L 0.21 J 0.44 J Arsenic 7440-38-2 T 10 02L pg/L 0.28 J 0.52 Barium 7440-39-3 D - p /L 20 16 Barium 7440-39-3 T 700 02L pg/L 23 13 Ter Ilium 7440-41-7 D - pg/L 0.2 U 0.2 U Beryllium 7440-41-7 T 4 IMAC pg/L 0.2 U 0.2 U Boron 7440-42-8 D - pg/L 50 U 50 U Boron 7440-42-8 T 700 02L p /L 50 U 50 U Cadmium 7440-43-9 D - p /L 0.08 U 0.08 U Cadmium 7440-43-9 T 2 02L pg/L 0.08 U 0.08 U Calcium 7440-70-2 T - p /L 72200 J- 44000 Chromium 7440-47-3 D - p /L 26.3 16.5 Chromium 7440-47-3 T 10 02L p /L 27 15.5 J+ Cobalt 7440-48-4 D - pg/L 0.5 U 0.5 U Cobalt 7440-48-4 T 1 IMAC p /L 0.5 U 0.5 U Copper 7440-50-8 D - pg/L 1.7 J+ 1.9 Copper 7440-50-8 T 1000 02L p /L 2.5 J+ 1.2 Iron 7439-89-6 D - pg/L 88 50 U Iron 7439-89-6 T 300 02L p /L 180 50 U Lead 7439-92-1 D - pg/L 0.1 U 0.2 Lead 7439-92-1 T 15 02L pg/L 0.091 J+ 0.1 U Magnesium 7439-95-4 T - pg/L 648 1440 Manganese 7439-96-5 D - p /L 4.6 J 5 U Manganese 7439-96-5 T 50 02L pg/L 8.1 5 U Mercury 7439-97-6 D - p /L 0.2 U 0.2 U Mercury 7439-97-6 T 1 02L pg/L 0.2 U 0.2 U Methane 74-82-8 N - p /L 1.4 J+ 1.4 J+ Molybdenum 7439-98-7 D pg/L 7 6.4 Molybdenum 7439-98-7 T p /L 7 6.3 Nickel 7440-02-0 D - pg/L 0.47 J+ 0.5 U Nickel 7440-02-0 T 100 02L p /L 0.45 J 0.5 U Potassium 7440-09-7 T - pg/L 4350 J 2680 J Selenium 7782-49-2 D - p /L 0.38 J 0.4 J Selenium 7782-49-2 T 20 02L pg/L 0.38 J 0.35 J Sodium 7440-23-5 T - p /L 15500 12900 Strontium 7440-24-6 D pg/L 300 220 Strontium 7440-24-6 T pg/L 300 180 Thallium 7440-28-0 D - pg/L 0.1 U 0.1 U Thallium 7440-28-0 T 0.2 IMAC p /L 0.1 U 0.1 U Vanadium 7440-62-2 D - pg/L 12.5 16.2 Vanadium 7440-62-2 T 0.3 IMAC p /L 12.8 16.3 Zinc 7440-66-6 D - pg/L 10 U 7.8 J+ Zinc 7440-66-6 T 1000 02L p /L 4.1 J+ 10 U Total Dissolved Solids TDS N 500000 02L pg/L 243000 147000 Total Organic Carbon TOC N - p /L 1000 U 1000 U Total Suspended Solids TSS N pg/L 24100 2500 U Alkalinity, CO3 ALK-0O3 N p /L 75600 49400 Alkalinity, HCO3 ALK-HCO3 N pg/L 87800 5000 U Alkalinity, lab ALK-LAB N - p /L 163000 61200 Chloride 16887-00-6 N 250000 02L pg/L 2400 2900 Fluoride 16984-48-8 N - p /L - 140 Nitrogen, NO2 plus NO3 NO2-NO3 N - pg/L 440 510 Sulfate 14808-79-8 N 250000 02L pg/L 27600 37900 Sulfide 18496-25-8 N - pg/L 100 U - Arsenic 7440-38-2 T 1 10 02L p /L - Chromium 7440-47-3 T 1 10 02L pg/L Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Page 29 of 30 Table 2-7 Groundwater Outside the Waste Boundary Analytical Results — Round 1 and Round 2 Location: Event: Sample Date: Sample Type Code: Sample Name/ID: MW-9D MW-9D MW-9D Round 1 Round 1 Round 2 7/2/2015 7/2/2015 9/18/2015 N N N MW-9D MW-9D RV-MW-9D-NS-3Q15 Constituent CAS RN Fraction Criteria Min (range only) NCDEQ 02L GWQS, IMACs, DHHS Criteria Source Unit Iron 7439-89-6 T 300 02L p /L Manganese 7439-96-5 D /L Manganese 7439-96-5 T 50 02L I pg/L - As III 7784-46-5 T /L 0.2 U As V 10103-60-3 T - N /L 0.303 Chromium VI 18540-29-9 D 0.07 DHHS /L - Chromium VI 18540-29-9 T 0.07 DHHS /L 22.1 Fe II 1345-25-1 T /L 101 Fe III 1309-37-1 T /L 678 Mn II 1344-43-0 T /L 5 U Mn IV 1313-13-9 T /L 18.9 Se IV 10102-18-8 T /L 0.5 U Se VI 13410-01-0 T /L 0.5 U Uranium, Natural 7440-61-1 T /L - Radium-226 13982-63-3 T Ci/L Radium-228 15262-20-1 T Ci/L Uranium-233 13968-55-3 T /L Uranium-234 13966-29-5 T /L Uranium-236 13982-70-2 T /L - Dissolved Oxygen DO N m /L 2.1 Temperature TEMP N - - Deg C 18.9 H PH N 6.5 8.5 02L SU 10.8 Turbidity, field TURB N - - NTU 7.6 Specific Conductivity field SC NPS/cm 370 Oxidation Reduction Potential ORP N mV 47 GW Depth TOC GW DEPTH-TOC N ft 20.52 Notes pm = micron pg/L = micrograms per liter pS/cm = microsiemens per centimeter ft = feet mg/L = milligrams per liter mV = millivolts NTU - nephelometric turbidity units pCi/L = picocuries per liter SU = standard unit J = laboratory estimated concentration J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius DHHS = North Carolina Department of Health and Human Services DO = dissolved oxygen GW = groundwater GWQS = groundwater quality standard IMAC = Interim Maximum Allow Concentration N = normal NS = no standard T = total TDS = total dissolved solids TOC = total organic carbon Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Page 30 of 30 Table 2-8 Constituents of Interest Evaluation Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin CHEMICAL -NAME CAS -RN FRACTION REPORT -RESULT -UNIT NC 2L Groundwater IMAC PPBC Turbidity, field TURB N NTU NS NS pH PH N SU 8.5 NS 4.6 - 8.5 Antimony 7440-36-0 D µg/I NS NS 1 Antimony 7440-36-0 T µg/I NS 1 1 Arsenic 7440-38-2 D µg/I NS NS 1 Arsenic 7440-38-2 T µg/I 10 NS 1 Matrix Location Location Description Sample Date Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff PW AB-3S Ash Basin 7/2/2015 105.E 258 257 283 282 PW Ash Basin 9/17/2015 105.1 -- -- -- 357 356 362 J+ 361 PW Ash Basin 6/28/2015 6.52 9.8 IN RNG -- -- 2.2 1.2 -- -- 428 427 PW AB-4S Ash Basin 9/17/2015 27.53 -- 2 1 1.8 0.8 278 277 3290 3289 PW Ash Basin 6/20/2015 3.34 23.8 22.8 21.6 20.6 644 643 651 650 PW AB-5S Ash Basin 6/25/2015 -- -- -- -- -- -- -- -- PW Ash Basin 9/15/2015 26.3 32.3 31.3 32.9 31.9 818 817 943 942 PW Ash Basin 6/8/2015 -- 2.9 1.9 3.2 2.2 69.7 68.7 75.1 74.1 PW AB-5SL Ash Basin 6/25/2015 1.86 10.73 IN RNG -- -- -- -- -- -- -- -- PW Ash Basin 9/16/2015 9.4 10.3 IN RNG 2.9 1.9 2.4 1.4 88.7 87.7 79 78 PW Ash Basin 6/22/2015 3.57 5.4 IN RNG -- -- -- -- 23.4 22.4 24.3 23.3 PW AB-7S Ash Basin 6/24/2015 -- -- -- -- -- PW Ash Basin 9/16/2015 32.7 5.7 IN RNG -- -- 173 172 PW C-is Cinder Storage 6/17/2015 3.14 4.96 IN RNG 25.5 24.5 25.8 24.8 PW Cinder Storage 9/15/2015 9 5.1 IN RNG -- -- -- -- -- -- 12 11 WG AB-1D Ash Basin 7/9/2015 16.89 11.6 IN RNG 1.5 0.5 6.3 5.3 WG Ash Basin 9/16/2015 5.88 11.7 IN RNG 4 3 3.3 2.3 WG AB-1S Ash Basin 7/9/2015 41.89 5.18 IN RNG 2.8 1.8 3.2 2.2 WG Ash Basin 9/16/2015 51.88 5.1 IN RNG -- -- -- -- -- -- -- -- -- -- -- -- WG Ash Basin 7/8/2015 6.23 10.94 IN RNG WG AB-21D Ash Basin 9/16/2015 -- WG Ash Basin 9/16/2015 10 9.3 IN RNG -- -- -- -- WG Ash Basin 7/8/2015 57.88 5.1 IN RNG 3.4 2.4 3.1 2.1 WG AB-2S Ash Basin 9/16/2015 -- -- -- -- -- WG Ash Basin 9/16/2015 31.5 5.1 IN RNG WG Ash Basin 7/23/2015 416.5 10.8 IN RNG -- -- WG AB-3BR Ash Basin 9/17/2015 -- 2.9 1.9 -- -- WG Ash Basin 9/17/2015 9.9 10.9 IN RNG 2.5 1.5 3.1 2.1 WG Ash Basin 7/7/2015 119.7 11.9 IN RNG -- -- -- -- WG AB-31D Ash Basin 9/17/2015 -- WG Ash Basin 9/17/2015 4.5 11.8 IN RNG -- -- -- -- WG AB-4D Ash Basin 7/8/2015 20.64 10.6 IN RNG 1.4 0.4 1.2 0.2 WG Ash Basin 9/17/2015 14.71 9.42 IN RNG 3.9 2.9 4.3 3.3 WG Ash Basin 6/20/2015 3.27 10.91 IN RNG -- -- 1.2 0.2 WG AB-5D Ash Basin 7/8/2015 -- -- -- -- -- WG Ash Basin 9/15/2015 -- 3.2 2.2 WG Ash Basin 9/15/2015 8.8 10.9 IN RNG 3.2 2.2 Ash Basin 6/22/2015 3.25 9.99 IN RNG -- -- -- -- AB-66RUAsh Ash Basin 7/2/2015 -- -- 2.5 1.5 NG Basin 9/16/2015 -- 5.4 4A-- -- -- Ash Basin 9/16/2015 9.78 10.65 IN RNG 5.7 4.7 3 2 WG Ash Basin 6/22/2015 18.8 11.91 IN RNG 1.7 0.7 1.8 0.8 WG AB-6S Ash Basin 7/1/2015 WG Ash Basin 9/17/2015 WG Ash Basin 9/17/2015 45.78 -- -- -- -- -- WG Ash Basin 7/1/2015 8.25 11.91 IN RNG 7.2 J+ 6.2 7.5 6.5 WG Ash Basin 9/16/2015 -- 1.8 J+ 0.8 -- -- WG AB-7D Ash Basin 9/16/2015 2.2 J+ 1.2 2.4 1.4 WG Ash Basin 9/16/2015 -- 2.2 J+ 1.2 -- -- WG Ash Basin 9/16/2015 4.22 11 IN RNG 2.4 J+ 1.4 2.6 1.6 WG Ash Basin 7/7/2015 20.01 5.83 IN RNG 3.6 2.6 -- -- WG AB-71 Ash Basin 9/17/2015 -- -- -- WG Ash Basin 9/17/2015 43 5.7 IN RNG WG Ash Basin 6/17/2015 -- WG AB-81D Ash Basin 6/17/2015 -- WG Ash Basin 9/16/2015 51.2 6.3 IN RNG WG AB 8S Ash Basin 6/20/2015 9.83 5.68 IN RNG WG Ash Basin 9/15/2015 30.4 5.6 IN RNG Page 1 of 20 Table 2-8 Constituents of Interest Evaluation Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin CHEMICAL -NAME CAS -RN FRACTION REPORT -RESULT -UNIT NC 2L Groundwater IMAC PPBC Turbidity, field TURB N NTU NS NS pH PH N SU 8.5 NS 4.6 - 8.5 Antimony 7440-36-0 D µg/I NS NS 1 Antimony 7440-36-0 T µg/I NS 1 1 Arsenic 7440-38-2 D µg/I NS NS 1 Arsenic 7440-38-2 T µg/I 10 NS 1 Matrix Location Location Description Sample Date Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff WG Ash Storage Area 6/5/2015 6.2 11.4 IN RNG 2.7 1.7 3 2 WG AS-1 D Ash Storage Area 7/1/2015 -- -- -- -- -- WG Ash Storage Area 9/8/2015 4 3 -- -- WG Ash Storage Area 9/8/2015 -- 3.7 2.7 3.3 2.3 WG Ash Storage Area 6/5/2015 14.2 6.4 IN RNG -- WG AS-1 S Ash Storage Area 7/1/2015 -- WG Ash Storage Area 9/8/2015 WG Ash Storage Area 9/8/2015 -- WG Ash Storage Area 6/8/2015 -- 1.3 J+ 0.3 WG AS-2D Ash Storage Area 7/1/2015 9.27 11.57 IN RNG -- -- WG Ash Storage Area 9/4/2015 -- 2.6 1.6 -- -- WG Ash Storage Area 9/4/2015 -- 2.6 1.6 2.5 1.5 WG Ash Storage Area 6/5/2015 12 5.3 IN RNG -- -- -- -- WG Ash Storage Area 7/1/2015 -- WG AS-2S Ash Storage Area 9/4/2015 WG jAsh Storage Area 9/4/2015 WG Ash Storage Area 9/8/2015 -- -- WG jAsh Storage Area 9/4/2015 -- -- -- 2.3 1.3 WG Ash Storage Area 6/5/2015 10 10.3 IN RNG 1.2 0.2 1.6 0.6 WG Ash Storage Area 7/1/2015 -- -- -- -- -- AS-3D Ash Storage Area 9/4/2015 -- -- -- -- !WG G Ash Storage Area 9/4/2015 1.2 0.2 1.4 0.4 G Ash Storage Area 9/4/2015 -- -- -- -- WG Ash Storage Area 9/4/2015 1.3 0.3 1.5 0.5 WG Ash Storage Area 7/7/2015 -- -- -- -- WG Ash Storage Area 9/4/2015 WG AS-3S Ash Storage Area 9/8/2015 WG Ash Storage Area 9/4/2015 WG Ash Storage Area 9/8/2015 -- -- -- -- WG Ash Storage Area 7/7/2015 48.37 1.8 0.8 1.7 0.7 WG AS-3SA Ash Storage Area 9/4/2015 -- -- -- -- WG Ash Storage Area 9/4/2015 -- -- -- -- WG CSA Background (sidegradient) 7/11/2015 4.2 3.2 4 3 WG BG-1D CSA Background (sidegradient) 7/11/2015 3.9 2.9 3.3 2.3 WG CSA Background (sidegradient) 9/18/2015 1.3 11.7 IN RNG 1.3 0.3 1.7 0.7 WG BG-1S CSA Background (sidegradient) 7/6/2015 13.71 5.75 IN RNG -- -- -- -- WG CSA Background (sidegradient) 9/17/2015 8.8 5.5 IN RNG -- -- -- -- -- -- -- -- -- -- -- -- WG CSA Background (sidegradient) 7/17/2015 -- -- -- -- -- -- -- -- -- -- WG BG-2BR CSA Background (sidegradient) 7/17/2015 7.38 WG CSA Background (sidegradient) 9/17/2015 9.89 -- -- -- -- -- -- -- -- -- WG BG-2D CSA Background (sidegradient) 7/11/2015 -- WG JCSA Background (sidegradient) 9/17/2015 9.9 11.7 IN RNG 2.9 1.9 3.9 2.9 WG BG 2S CSA Background (sidegradient) 7/10/2015 -- -- -- -- -- WG CSA Background (sidegradient) 9/17/2015 5 5.8 IN RNG -- -- -- -- -- -- -- -- -- -- -- -- WG BG-3D CSA Background (sidegradient) 7/6/2015 123.6 -- WG CSA Background (sidegradient) 9/17/2015 7.4 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG BG-3S CSA Background (sidegradient) 6/30/2015 1.93 6.15 IN RNG 1.4 J+ 0.4 1.3 J+ 0.3 WG CSA Background (sidegradient) 9/17/2015 1.2 6.2 IN RNG -- -- -- -- -- -- -- -- -- -- -- -- WG C-1 BRU Cinder Storage 9/15/2015 9.7 12.3 IN RNG 3.2 2.2 3.1 2.1 WG Cinder Storage 6/19/2015 7.62 9.36 IN RNG -- -- -- -- WG Cinder Storage 6/25/2015 -- WG C-2 D Cinder Storage 9/18/2015 WG Cinder Storage 9/18/2015 WG Cinder Storage 9/18/2015 WG Cinder Storage 9/18/2015 46.32 -- -- WG Cinder Storage 6/19/2015 6A 4.16 -0.44 WG Cinder Storage 6/25/2015 -- -- WG C-2S Cinder Storage 9/17/2015 WG Cinder Storage 1 9/17/2015 WG Cinder Storage 1 9/17/2015 Page 2 of 20 Table 2-8 Constituents of Interest Evaluation Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin CHEMICAL -NAME CAS -RN FRACTION REPORT -RESULT -UNIT NC 2L Groundwater IMAC PPBC Turbidity, field TURB N NTU NS NS pH PH N SU 8.5 NS 4.6 - 8.5 Antimony 7440-36-0 D µg/I NS NS 1 Antimony 7440-36-0 T µg/I NS 1 1 Arsenic 7440-38-2 D µg/I NS NS 1 Arsenic 7440-38-2 T µg/I 10 NS 1 Matrix Location Location Description Sample Date Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff WG Cinder Storage 9/17/2015 18.2 4.2 -0.4 -- -- -- -- WG GWA-10BRU Downgradient 9/16/2015 4.4 11.7 IN RNG 2 1 8.6 7.6 WG GWA-10D Downgradient 7/3/2015 7.75 10.92 IN RNG -- -- 1.1 0.1 WG GWA-10S Downgradient 7/2/2015 4.4 5.17 IN RNG -- -- WG Downgradient 9/16/2015 6.7 5.4 IN RNG -- -- -- -- -- -- -- -- -- -- -- -- WG GWA-1BRU Downgradient 9/16/2015 7.4 8.9 IN RNG -- -- -- -- WG GWA-1 D Downgradient NW 7/2/2015 21.25 11.22 IN RNG 2.6 1.6 3.2 2.2 WG GWA-1S Downgradient NW 7/2/2015 47.36 6.07 IN RNG -- -- -- -- WG Downgradient NW 9/16/2015 70.4 6.1 IN RNG -- -- -- -- -- -- -- -- -- -- -- -- WG GWA-20BR Ash Storage Upgradient 7/27/2015 8.62 11.9 IN RNG -- -- -- -- WG jAsh Storage Upgradient 9/19/2015 4.8 11.6 IN RNG 24.6 23.6 25.3 24.3 WG Ash Storage Upgradient 7/16/2015 8.95 12.5 IN RNG -- -- -- -- WG GWA-20D Ash Storage Upgradient 9/19/2015 3.86 13.56 IN RNG -- -- -- -- -- -- -- -- -- -- -- -- WG GWA-20S Ash Storage Upgradient 7/11/2015 21.15 5.3 IN RNG WG Ash Storage Upgradient 9/16/2015 8.4 5.2 IN RNG -- -- -- -- -- -- -- -- -- -- -- -- WG Upgradient 8/27/2015 -- WG Upgradient 8/27/2015 -- -- WG GWA-21BR Upgradient 9/15/2015 1.1 0.1 WG Upgradient 9/17/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG Upgradient 9/15/2015 12.2 11.7 IN RNG 2.3 1.3 WG Upgradient 9/17/2015 2.2 -- -- -- WG GWA-21 D Upgradient 9/18/2015 -- WG Upgradient 9/18/2015 155.6 9.2 IN RNG WG Upgradient 8/14/2015 -- WG GWA-21S Upgradient 9/16/2015 -- WG Upgradient 9/16/2015 10 5 IN RNG WG GWA-22BR Ash Storage Upgradient 7/21/2015 1.04 11.4 IN RNG WG Ash Storage Upgradient 9/18/2015 7.98 9.96 IN RNG WG GWA-22D Ash Storage Upgradient 7/10/2015 71.72 11 IN RNG 1.4 0.4 WG Ash Storage Upgradient 9/17/2015 7.9 10.2 IN RNG -- -- -- -- -- -- -- -- -- -- -- -- WG GWA-22S Ash Storage Upgradient 7/10/2015 8.32 5.18 IN RNG 3.5 2.5 2.2 1.2 WG Ash Storage Upgradient 9/16/2015 9.74 5.2 IN RNG -- -- -- -- -- -- -- -- -- -- -- -- WG Ash Storage Upgradient 7/17/2015 -- WG GWA-23BR Ash Storage Upgradient 7/17/2015 10.2 12.2 IN RNG WG Ash Storage Upgradient 9/19/2015 -- 2.5 1.5 -- -- -- -- -- -- -- -- -- WG Ash Storage Upgradient 9/19/2015 8.1 11.5 IN RNG 1.8 0.8 1.3 0.3 WG Ash Storage Upgradient 7/16/2015 4.15 11.2 IN RNG -- -- -- -- WG GWA-23D Ash Storage Upgradient 9/18/2015 -- WG Ash Storage Upgradient 9/18/2015 5.52 11.09 IN RNG WG Ash Storage Upgradient 7/10/2015 9.05 5.3 IN RNG WG GWA-23S Ash Storage Upgradient 9/16/2015 -- WG Ash Storage Upgradient 9/16/2015 2.4 5 IN RNG WG GWA-2BR Downgradient of Ash Basin 6/17/2015 -- WG Downgradient of Ash Basin 9/17/2015 10 8.7 IN RNG -- -- -- -- -- -- -- -- -- -- -- -- WG Downgradient of Ash Basin 7/8/2015 116.4 12.11 IN RNG 22.4 21.4 WG GWA-2BRU Downgradient of Ash Basin 7/9/2015 -- -- -- WG Downgradient of Ash Basin 7/10/2015 -- -- -- 18.2 17.2 WG Downgradient of Ash Basin 9/17/2015 3.5 11.9 IN RNG 1.2 0.2 1.2 0.2 WG GWA-2S Downgradient of Ash Basin 6/22/2015 7.72 5.83 IN RNG -- -- -- -- WG Downgradient of Ash Basin 9/18/2015 41.7 5.9 IN RNG -- -- -- -- -- -- -- -- -- -- -- -- WG GWA-3D Downgradient of Coal Pile 6/17/2015 1.55 -- WG Downgradient of Coal Pile 9/15/2015 1.34 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG GWA-3SA Downgradient of Coal Pile 7/1/2015 7.84 5.94 IN RNG WG Downgradient of Coal Pile 9/15/2015 9.71 5.97 IN RNG -- -- -- -- -- -- -- -- -- -- -- -- WG Upgradient of Ash Storage 7/27/2015 -- 1.31 0.31 1.22 0.22 WG GWA-4BR Upgradient of Ash Storage 7/27/2015 5.8 12.5 IN RNG 1.41 0.41 -- -- WG Upgradient of Ash Storage 9/17/2015 2.1 12 IN RNG 4.9 3.9 5.8 4.8 WG GWA-4D Upgradient of Ash Storage 7/10/2015 -- WG Upgradient of Ash Storage 9/17/2015 4.3 WG Upgradient of Ash Storage 1 7/10/2015 Page 3 of 20 Table 2-8 Constituents of Interest Evaluation Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin CHEMICAL -NAME CAS -RN FRACTION REPORT -RESULT -UNIT NC 2L Groundwater IMAC PPBC Turbidity, field TURB N NTU NS NS pH PH N SU 8.5 NS 4.6 - 8.5 Antimony 7440-36-0 D µg/I NS NS 1 Antimony 7440-36-0 T µg/I NS 1 1 Arsenic 7440-38-2 D µg/I NS NS 1 Arsenic 7440-38-2 T µg/I 10 NS 1 Matrix Location Location Description Sample Date Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff WG Upgradient of Ash Storage 9/17/2015 6.9 5.7 IN RNG WG GWA-5D Upgradient of Ash Storage 7/11/2015 2.01 10.3 IN RNG WG Upgradient of Ash Storage 9/16/2015 57.9 10.5 IN RNG -- -- -- -- -- -- -- -- -- -- -- -- WG GWA-5S Upgradient of Ash Storage 6/18/2015 1.92 3.56 -1.04 WG Upgradient of Ash Storage 6/19/2015 3.98 11.37 IN RNG WG Upgradient of Ash Storage 6/24/2015 -- -- -- WG Upgradient of Ash Storage 9/18/2015 -- 4.6 3.6 -- WG Upgradient of Ash Storage 9/18/2015 22.5 11.5 IN RNG 4.3 3.3 3A 2.4 WG Upgradient of Ash Storage 6/19/2015 -- -- -- -- -- -- -- -- -- -- WG GWA-6S Upgradient of Ash Storage 6/25/2015 85.2 6.25 IN RNG WG Upgradient of Ash Storage 9/18/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG Upgradient of Ash Storage 9/18/2015 43.6 4.7 IN RNG WG Side Gradient of Ash Basin East 7/7/2015 -- WG GWA-7BR Side Gradient of Ash Basin East 9/15/2015 -- WG Side Gradient of Ash Basin East 9/15/2015 8.45 8.6 IN RNG WG Side Gradient of Ash Basin East 6/17/2015 3.9 -- WG GWA-71D Side Gradient of Ash Basin East 9/15/2015 41.72 -- WG GWA-7S Side Gradient of Ash Basin East 6/19/2015 3.12 4.99 IN RNG WG GWA-8D Side Gradient of Ash Basin East 6/28/2015 5.23 -- WG Side Gradient of Ash Basin East 9/18/2015 6.5 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG GWA-8S Side Gradient of Ash Basin East 6/28/2015 1.86 5.03 IN RNG WG Side Gradient of Ash Basin East 9/18/2015 5.9 5.2 IN RNG WG GWA-9BR Side Gradient of Ash Basin East 7/10/2015 137.3 11.54 IN RNG 4.5 3.5 10.7 9.7 WG Side Gradient of Ash Basin East 7/1/2015 -- -- -- -- -- WG GWA-91D Side Gradient of Ash Basin East 9/16/2015 -- WG Side Gradient of Ash Basin East 9/16/2015 7.04 6.2 IN RNG WG Side Gradient of Ash Basin East 6/30/2015 7.93 4.82 IN RNG WG GWA-9S Side Gradient of Ash Basin East 9/16/2015 -- WG Side Gradient of Ash Basin East 9/16/2015 8.04 5 IN RNG WG Side Gradient Northwest 6/23/2015 -- -- WG MW-10 Side Gradient Northwest 6/23/2015 4.88 4.57 -0.03 WG Side Gradient Northwest 6/29/2015 -- -- WG Side Gradient Northwest 7/2/2015 8.8 5.9 IN RNG WG MW-11DR Side Gradient Northwest 7/2/2015 -- WG Side Gradient Northwest 7/2/2015 8.1 5.8 IN RNG WG Downgradient North East Basin 6/30/2015 -- WG MW-13 Downgradient North East Basin 6/30/2015 WG Downgradient North East Basin 6/30/2015 0.95 WG MW-14 Downgradient North East Basin 6/30/2015 1.97 -- -- WG Downgradient 6/23/2015 3.6 4.31 -0.29 WG MW-15 Downgradient 6/29/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW-15BR Downgradient 6/23/2015 4.54 11.21 IN RNG WG Downgradient 9/15/2015 6.18 11.9 IN RNG -- -- -- -- -- -- -- -- -- -- -- -- WG MW-15D Downgradient 6/18/2015 -- WG Downgradient 9/15/2015 8.98 10.3 IN RNG -- -- -- -- -- -- -- -- -- -- -- -- WG Ash Basin 6/29/2015 4.13 6.08 IN RNG WG MW-1D Ash Basin 9/18/2015 -- WG Ash Basin 9/18/2015 3.5 6 IN RNG WG Ash Basin 6/29/2015 6.82 -- WG MW-1S Ash Basin 9/18/2015 WG Ash Basin 9/18/2015 5.9 -- WG MW 2D Ash Basin NW Boundary 6/30/2015 5.36 6.35 IN RNG WG Ash Basin NW Boundary 9/18/20151 7.46 6.29 IN RNG -- -- -- -- -- -- -- -- -- -- -- -- WG MW-3D Downgradient 6/30/2015 2.8 -- WG Downgradient 9/16/2015 0.81 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW-3S Downgradient 6/30/2015 5.06 6.04 IN RNG WG Downgradient 9/16/20151 6.91 6.3 IN RNG Page 4 of 20 Table 2-8 Constituents of Interest Evaluation Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin CHEMICAL -NAME CAS -RN FRACTION REPORT -RESULT -UNIT NC 2L Groundwater IMAC PPBC Turbidity, field TURB N NTU NS NS pH PH N SU 8.5 NS 4.6 - 8.5 Antimony 7440-36-0 D µg/I NS NS 1 Antimony 7440-36-0 T µg/I NS 1 1 Arsenic 7440-38-2 D µg/I NS NS 1 Arsenic 7440-38-2 T µg/I 10 NS 1 Matrix Location Location Description Sample Date Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff WG MW-4D Downgradient North East Basin 6/18/2015 4.52 4.59 -0.01 WG Downgradient North East Basin 9/17/2015 2.6 5.71 IN RNG -- -- -- -- -- -- -- -- -- -- -- -- WG MW-4S Downgradient North East Basin 9/17/2015 648 5.7 IN RNG WG MW-5D Downgradient North East Basin 6/18/2015 1.82 6.34 IN RNG WG Downgradient North East Basin 9/17/2015 1.4 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW-5S Downgradient North East Basin 6/25/2015 3.68 5.93 IN RNG WG Downgradient North East Basin 9/17/2015 0.7 5.05 IN RNG -- -- -- -- -- -- -- -- -- -- -- -- WG MW-6D Downgradient North East Basin 6/18/2015 -- WG Downgradient North East Basin 9/18/2015 2.5 6.32 IN RNG -- -- -- -- -- -- -- -- -- -- -- -- WG MW-6S Downgradient North East Basin 6/18/2015 5.57 6.37 IN RNG WG Downgradient North East Basin 9/17/2015 3.9 6.25 IN RNG -- -- -- -- -- -- -- -- -- -- -- -- WG MW 7BR Side Gradient East of Ash Basin 7/10/2015 -- WG Side Gradient East of Ash Basin 9/15/2015 6.4 12.26 IN RNG 1.6 0.6 WG MW 7D Side Gradient East of Ash Basin 9/16/2015 -- -- -- WG Side Gradient East of Ash Basin 9/16/2015 5 5.63 IN RNG WG MW-7SR Side Gradient East of Ash Basin 9/16/2015 427 5.36 IN RNG WG MW-81D Side Gradient East of Ash Basin 7/1/2015 84.3 6.37 IN RNG WG MW-8I Side Gradient East of Ash Basin 7/1/2015 34.1 5.68 j IN RNG WG MW-8S Side Gradient East of Ash Basin 6/30/2015 8.45 6.1 IN RNG WG Side Gradient East of Ash Basin 7/6/2015 WG MW-9 Side Gradient East of Ash Basin 7/6/2015 -- WG Side Gradient East of Ash Basin 7/6/2015 8.43 6.1 IN RNG -- -- -- -- WG Side Gradient East of Ash Basin 7/2/2015 1.7 11.4 IN RNG 1.3 0.3 2.3 1.3 WG MW-9BR Side Gradient East of Ash Basin 9/18/2015 -- 2.5 1.5 -- -- WG Side Gradient East of Ash Basin 9/18/2015 3.8 10.11 IN RNG 2.5 1.5 3.2 2.2 WG Side Gradient East of Ash Basin 7/1/2015 -- -- -- -- -- WG Side Gradient East of Ash Basin 7/1/2015 -- 9.3 J+ 8.3 5.3 4.3 WG Side Gradient East of Ash Basin 7/1/2015 7.06 11.49 IN RNG 16.8 15.8 5A 4.4 WG MW-91D Side Gradient East of Ash Basin 7/2/2015 -- -- -- -- -- WG Side Gradient East of Ash Basin 7/2/2015 2.6 1.6 2.7 1.7 WG Side Gradient East of Ash Basin 9/18/2015 1.4 0.4 -- -- WG I I Side Gradient East of Ash Basin 9/18/2015 7.6 10.8 IN RNG 1.7 0.7 1.1 0.1 Notes: Orange > groundwater standard and> PPBC Green => groundwater standard but < PPBC pg/L = micrograms per liter NTU = nephelometric turbidity units SU = standard unit J- = estimated concentration, biased low J = laboratory estimated concentration J+ = estimated concentration, biased high U = results not detected 02L = standards as found in T15A NCAC 02L CAS -RN = Chemical Abstracts Service Registry Number D = dissolved IMAC = Interim Maximum Allow Concentration IN RNG = in range N = normal NS = no standard PPBC = Proposed Provisional Background Concentration Q = qualifier T = total Page 5 of 20 Table 2-8 Constituents of Interest Evaluation Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin CHEMICAL -NAME CAS -RN FRACTION REPORT -RESULT -UNIT NC 2L Groundwater IMAC PPBC Boron 7440-42-8 D µg/1 NS NS 50 Boron 7440-42-8 T µg/I 700 NS 50 Chromium 7440-47-3 T µg/I 10 NS 5 Chromium 7440-47-3 D µg/l NS NS 5 Chromium 7440-47-3 T µg/I 10 NS 5 Cobalt 7440-48-4 D µg/1 NS NS 3 Matrix Location Location Description Sample Date Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff PW AB-3S Ash Basin 7/2/2015 -- -- 1.3 -1.7 PW Ash Basin 9/17/2015 17.6 J+ 12.6 -- -- PW Ash Basin 6/28/2015 -- -- -- -- PW AB-4S Ash Basin 9/17/2015 24.3 19.3 1.5 -1.5 PW Ash Basin 6/20/2015 1400 1350 1400 1350 -- -- -- -- PW AB-5S Ash Basin 6/25/2015 -- -- -- -- PW Ash Basin 9/15/2015 1600 1550 1500 1450 PW Ash Basin 6/8/2015 2100 2050 2400 2350 PW AB-5SL Ash Basin 6/25/2015 -- -- -- -- PW Ash Basin 9/16/2015 2200 2150 2300 2250 -- -- PW Ash Basin 6/22/2015 -- -- -- -- 13.7 10.7 PW AB-7S Ash Basin 6/24/2015 -- -- PW Ash Basin 9/16/2015 13.2 10.2 PW C-is Cinder Storage 6/17/2015 115 112 PW Cinder Storage 9/15/2015 -- -- -- -- 299 296 WG AB-1D Ash Basin 7/9/2015 21.2 16.2 49.2 44.2 -- -- WG Ash Basin 9/16/2015 19.7 1 14.7 17 1 12 WG AB-1S Ash Basin 7/9/2015 -- -- -- -- 16.2 13.2 WG Ash Basin 9/16/2015 -- -- -- -- 14.5 11.5 WG Ash Basin 7/8/2015 13.4 8.4 12.1 7.1 13 8 -- -- WG AB-21D Ash Basin 9/16/2015 -- -- -- -- -- -- WG Ash Basin 9/16/2015 -- -- WG Ash Basin 7/8/2015 15.9 12.9 WG AB-2S Ash Basin 9/16/2015 30.8 27.8 WG Ash Basin 9/16/2015 32.1 29.1 WG Ash Basin 7/23/2015 -- -- WG AB-3BR Ash Basin 9/17/2015 WG Ash Basin 9/17/2015 WG Ash Basin 7/7/2015 57.4 52.4 45.3 40.3 51 46 WG AB-31D Ash Basin 9/17/2015 -- -- 23.2 18.2 -- -- WG Ash Basin 9/17/2015 23.5 18.5 26 J+ 21 WG AB-4D Ash Basin 7/8/2015 -- -- -- -- WG Ash Basin 9/17/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG Ash Basin 6/20/2015 WG AB-51D Ash Basin 7/8/2015 WG Ash Basin 9/15/2015 WG Ash Basin 9/15/2015 Ash Basin 6/22/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- tWG WG AB-66RU Ash Basin 7/2/2015 WG Ash Basin 9/16/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG Ash Basin 9/16/2015 WG Ash Basin 6/22/2015 WG AB-6S Ash Basin 7/1/2015 WG Ash Basin 9/17/2015 WG Ash Basin 9/17/2015 WG Ash Basin 7/1/2015 32.9 27.9 26.4 21.4 24.7 19.7 WG Ash Basin 9/16/2015 -- -- 23.4 18.4 -- -- WG AB-7D Ash Basin 9/16/2015 24.8 19.8 26.1 21.1 WG Ash Basin 9/16/2015 23.1 18.1 -- -- WG Ash Basin 9/16/2015 24 19 26.4 21.4 -- -- WG Ash Basin 7/7/2015 -- -- -- -- 1.5 -1.5 WG AB-71 Ash Basin 9/17/2015 2 -1 WG Ash Basin 9/17/2015 1.3 -1.7 WG Ash Basin 6/17/2015 -- -- WG AB-81D Ash Basin 6/17/2015 WG Ash Basin 9/16/2015 WG AB-8S Ash Basin 6/20/2015 -- -- WG Ash Basin 1 9/15/20151 1 26.2 21.2 Page 6 of 20 Table 2-8 Constituents of Interest Evaluation Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin CHEMICAL -NAME CAS -RN FRACTION REPORT -RESULT -UNIT NC 2L Groundwater IMAC PPBC Boron 7440-42-8 D µg/I NS NS 50 Boron 7440-42-8 T µg/I 700 NS 50 Chromium 7440-47-3 T µg/I 10 NS 5 Chromium 7440-47-3 D µg/I NS NS 5 Chromium 7440-47-3 T µg/I 10 NS 5 Cobalt 7440-48-4 D µg/I NS NS 3 Matrix Location Location Description Sample Date Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff WG Ash Storage Area 6/5/2015 -- -- 830 825 903 898 WG AS-1 D Ash Storage Area 7/1/2015 974 969 -- -- -- -- WG Ash Storage Area 9/8/2015 -- -- 826 821 -- -- WG Ash Storage Area 9/8/2015 838 833 868 863 -- -- WG Ash Storage Area 6/5/2015 1900 1850 2200 2150 -- -- -- -- 5.3 2.3 WG AS-1 S Ash Storage Area 7/1/2015 -- -- -- -- -- -- WG Ash Storage Area 9/8/2015 1700 1650 -- -- 6.8 3.8 WG Ash Storage Area 9/8/2015 2000 1950 1400 1350 -- -- -- -- 5.4 2.4 WG Ash Storage Area 6/8/2015 -- -- -- -- -- -- 20.7 15.7 22.5 17.5 -- -- WG Ash Storage Area 7/1/2015 22.5 17.5 -- -- -- -- WG WG Ash Storage Area 9/4/2015 -- -- 17.2 12.2 -- WG Ash Storage Area 9/4/2015 17 12 17.4 12.4 -- -- WG Ash Storage Area 6/5/2015 10.2 5.2 44.8 39.8 10.1 7.1 WG Ash Storage Area 7/1/2015 -- -- -- -- -- -- WG AS-2S Ash Storage Area 9/4/2015 8.5 5.5 WG jAsh Storage Area 9/4/2015 8.5 5.5 WG Ash Storage Area 9/8/2015 1700 1650 -- -- 6.8 3.8 WG jAsh Storage Area 9/4/2015 -- -- -- -- 36.4 31.4 8 5 WG Ash Storage Area 6/5/2015 -- -- 20.9 15.9 23.5 18.5 -- -- WG Ash Storage Area 7/1/2015 28.3 23.3 -- -- -- -- WG AS-31D Ash Storage Area 9/4/2015 -- -- 14.1 9.1 -- -- WG Ash Storage Area 9/4/2015 14.6 9.6 15.3 J 10.3 WG Ash Storage Area 9/4/2015 13.1 8.1 -- -- WG Ash Storage Area 9/4/2015 14.8 9.8 18.8 J 13.8 WG Ash Storage Area 7/7/2015 -- -- -- -- WG Ash Storage Area 9/4/2015 -- -- WG AS-3S Ash Storage Area 9/8/2015 -- -- 20.1 17.1 WG Ash Storage Area 9/4/2015 12.4 7.4 -- -- WG Ash Storage Area 9/8/2015 -- -- 11 8 WG Ash Storage Area 7/7/2015 -- -- WG AS-3SA Ash Storage Area 9/4/2015 940 890 -- -- 12.3 9.3 WG Ash Storage Area 9/4/2015 940 890 980 930 -- -- -- -- 12.2 9.2 WG CSA Background (sidegradient) 7/11/2015 -- -- -- -- 30.1 25.1 51.9 46.9 1.4 -1.6 WG BG-11D CSA Background (sidegradient) 7/11/2015 28.7 23.7 32.3 27.3 1.3 -1.7 WG CSA Background (sidegradient) 9/18/2015 -- -- 13.7 8.7 -- -- WG BG-1S CSA Background (sidegradient) 7/6/2015 -- -- 1.9 -1.1 WG CSA Background (sidegradient) 9/17/2015 1 -2 WG CSA Background (sidegradient) 7/17/2015 -- -- -- -- -- -- -- -- -- -- WG BG-2BR CSA Background (sidegradient) 7/17/2015 WG CSA Background (sidegradient) 9/17/2015 -- -- -- -- -- -- -- -- -- -- WG BG-21D CSA Background (sidegradient) 7/11/2015 55.9 50.9 57.5 52.5 WG CSA Background (sidegradient) 9/17/2015 70.3 65.3 99.2 94.2 WG BG 2S CSA Background (sidegradient) 7/10/2015 WG CSA Background (sidegradient) 9/17/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG BG-3D CSA Background (sidegradient) 7/6/2015 WG CSA Background (sidegradient) 9/17/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG BG-3S CSA Background (sidegradient) 6/30/2015 WG CSA Background (sidegradient) 9/17/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG C-1 BRU Cinder Storage 9/15/2015 WG Cinder Storage 6/19/2015 WG Cinder Storage 6/25/2015 WG C-2 D Cinder Storage 9/18/2015 WG Cinder Storage 9/18/2015 WG Cinder Storage 9/18/2015 WG Cinder Storage 9/18/2015 WG Cinder Storage 6/19/2015 42.5 39.5 Cinder Storage 6/25/2015 -- -- WG C 2S Cinder Storage 9/17/2015 31.6 28.6 UWG WG Cinder Storage 9/17/2015 32.4 29.4 WG Cinder Storage 9/17/2015 32.7 1 29.7 Page 7 of 20 Table 2-8 Constituents of Interest Evaluation Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin CHEMICAL -NAME CAS -RN FRACTION REPORT -RESULT -UNIT NC 2L Groundwater IMAC PPBC Boron 7440-42-8 D µg/I NS NS 50 Boron 7440-42-8 T µg/I 700 NS 50 Chromium 7440-47-3 T µg/I 10 NS 5 Chromium 7440-47-3 D µg/I NS NS 5 Chromium 7440-47-3 T µg/I 10 NS 5 Cobalt 7440-48-4 D µg/I NS NS 3 Matrix Location Location Description Sample Date Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff WG Cinder Storage 9/17/2015 15.8 10.8 32.5 29.5 WG GWA-10BRU Downgradient 9/16/2015 -- -- -- -- WG GWA-10D Downgradient 7/3/2015 -- -- WG GWA-10S Downgradient 7/2/2015 10.3 7.3 WG Downgradient 9/16/2015 11 8 WG GWA-1 BRU Downgradient 9/16/2015 -- -- WG GWA-1 D Downgradient NW 7/2/2015 -- -- WG GWA-1S Downgradient NW 7/2/2015 11.6 6.6 WG Downgradient NW 9/16/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG GWA-20BR Ash Storage Upgradient 7/27/2015 -- -- 16.7 11.7 WG jAsh Storage Upgradient 9/19/2015 16.8 11.8 192 187 WG Ash Storage Upgradient 7/16/2015 144 139 186 181 -- -- WG GWA-20D Ash Storage Upgradient 9/19/2015 247 242 164 J+ 159 2.2 -0.8 WG GWA-20S Ash Storage Upgradient 7/11/2015 -- -- 133 128 3 0 WG Ash Storage Upgradient 9/16/2015 -- -- 2.2 -0.8 WG Upgradient 8/27/2015 -- -- WG Upgradient 8/27/2015 WG GWA-21BR Upgradient 9/15/2015 10 5 WG Upgradient 9/17/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG Upgradient 9/15/2015 11.4 6.4 WG Upgradient 9/17/2015 10.8 5.8 -- -- WG GWA-21D Upgradient 9/18/2015 -- -- 1.5 -1.5 WG Upgradient 9/18/2015 17.6 12.6 -- -- WG Upgradient 8/14/2015 -- -- 4 1 WG GWA-21S Upgradient 9/16/2015 4.7 1.7 WG Upgradient 9/16/2015 -- -- 4.5 1.5 WG GWA-22BR Ash Storage Upgradient 7/21/2015 49.5 44.5 108 103 -- -- WG Ash Storage Upgradient 9/18/2015 15 10 29 24 WG GWA-22D Ash Storage Upgradient 7/10/2015 171 166 174 169 WG Ash Storage Upgradient 9/17/2015 115 110 125 120 WG GWA-22S Ash Storage Upgradient 7/10/2015 -- -- -- -- 1.2 -1.8 WG Ash Storage Upgradient 9/16/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG Ash Storage Upgradient 7/17/2015 14.5 9.5 13.5 8.5 15.2 10.2 WG GWA-23BR Ash Storage Upgradient 7/17/2015 15.1 10.1 13.4 8.4 15.6 10.6 WG Ash Storage Upgradient 9/19/2015 -- -- 27.7 22.7 WG jAsh Storage Upgradient 9/19/2015 -- -- -- -- 17 12 WG Ash Storage Upgradient 7/16/2015 56.3 51.3 53.6 48.6 55 50 WG GWA-23D Ash Storage Upgradient 9/18/2015 -- -- 34.9 29.9 -- -- WG Ash Storage Upgradient 9/18/2015 39.1 34.1 54 49 -- -- WG Ash Storage Upgradient 7/10/2015 -- -- -- -- 3.1 0.1 WG GWA-23S Ash Storage Upgradient 9/16/2015 3.3 0.3 WG Ash Storage Upgradient 9/16/2015 3.3 0.3 WG GWA-2BR Downgradient of Ash Basin 6/17/2015 -- -- WG Downgradient of Ash Basin 9/17/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG Downgradient of Ash Basin 7/8/2015 22.9 17.9 WG GWA-2BRU Downgradient of Ash Basin 7/9/2015 -- -- -- -- WG Downgradient of Ash Basin 7/10/2015 -- -- 46 41 WG Downgradient of Ash Basin 9/17/2015 38.4 33.4 40.2 J+ 35.2 WG GWA-2S Downgradient of Ash Basin 6/22/2015 -- -- -- -- WG Downgradient of Ash Basin 9/18/2015 -- -- WG GWA-3D Downgradient of Coal Pile 6/17/2015 1.2 -1.8 WG Downgradient of Coal Pile 9/15/2015 1.4 -1.6 WG GWA-3SA Downgradient of Coal Pile 7/1/2015 19.8 16.8 WG Downgradient of Coal Pile 9/15/2015 -- -- -- -- 4.1 1.1 WG Upgradient of Ash Storage 7/27/2015 29.2 24.2 31.5 26.5 -- -- WG GWA-4BR Upgradient of Ash Storage 7/27/2015 29.4 24.4 38.1 33.1 WG Upgradient of Ash Storage 9/17/20151 19.3 14.3 23.8 18.8 WG GWA-4D Upgradient of Ash Storage 7/10/2015 WG Upgradient of Ash Storage 9/17/2015 WG r- nio_ac Upgradient of Ash Storage 7/10/2015 -- I -- I -- -- I -- I -- 1.4 1 1 -1.6 Page 8 of 20 Table 2-8 Constituents of Interest Evaluation Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin CHEMICAL -NAME CAS -RN FRACTION REPORT -RESULT -UNIT NC 2L Groundwater IMAC PPBC Boron 7440-42-8 D µg/I NS NS 50 Boron 7440-42-8 T µg/I 700 NS 50 Chromium 7440-47-3 T µg/I 10 NS 5 Chromium 7440-47-3 D µg/I NS NS 5 Chromium 7440-47-3 T µg/I 10 NS 5 Cobalt 7440-48-4 D µg/I NS NS 3 Matrix Location Location Description Sample Date Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff WG Upgradient of Ash Storage 9/17/2015 -- -- -- -- -- -- -- -- -- -- WG GWA-5D Upgradient of Ash Storage 7/11/2015 11.9 6.9 24.5 19.5 WG Upgradient of Ash Storage 9/16/2015 10.4 5.4 11 6 WG GWA-5S Upgradient of Ash Storage 6/18/2015 -- -- -- -- 4.6 1.6 WG Upgradient of Ash Storage 6/19/2015 21 16 24.8 19.8 -- -- WG GWA-61D Upgradient of Ash Storage 6/24/2015 -- -- -- -- -- -- -- -- -- -- WG Upgradient of Ash Storage 9/18/2015 28.1 23.1 -- WG Upgradient of Ash Storage 9/18/2015 26.1 21.1 35 30 -- -- WG Upgradient of Ash Storage 6/19/2015 -- -- -- -- 25.3 22.3 WG GWA-6S Upgradient of Ash Storage 6/25/2015 -- -- WG Upgradient of Ash Storage 9/18/2015 24.5 21.5 WG Upgradient of Ash Storage 9/18/2015 -- -- -- -- -- -- -- -- -- -- WG Side Gradient of Ash Basin East 7/7/2015 WG GWA-7BR Side Gradient of Ash Basin East 9/15/2015 WG Side Gradient of Ash Basin East 9/15/2015 WG Side Gradient of Ash Basin East 6/17/2015 WG GWA-7D Side Gradient of Ash Basin East 9/15/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG GWA-7S Side Gradient of Ash Basin East 6/19/2015 WG GWA-8D Side Gradient of Ash Basin East 6/28/2015 WG Side Gradient of Ash Basin East 9/18/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG GWA-8S Side Gradient of Ash Basin East 6/28/2015 2 -1 WG Side Gradient of Ash Basin East 9/18/2015 -- 31.4 28.4 WG GWA-9BR Side Gradient of Ash Basin East 7/10/2015 40.6 35.6 -- -- WG Side Gradient of Ash Basin East 7/1/2015 -- -- WG GWA-9D Side Gradient of Ash Basin East 9/16/2015 WG Side Gradient of Ash Basin East 9/16/2015 -- -- WG Side Gradient of Ash Basin East 6/30/2015 51 48 WG GWA-9S Side Gradient of Ash Basin East 9/16/2015 43.2 40.2 WG Side Gradient of Ash Basin East 9/16/2015 44.7 41.7 WG Side Gradient Northwest 6/23/2015 -- -- WG MW-10 Side Gradient Northwest 6/23/2015 WG Side Gradient Northwest 6/29/2015 WG Side Gradient Northwest 7/2/2015 WG MW-11DR Side Gradient Northwest 7/2/2015 WG Side Gradient Northwest 7/2/2015 WG Downgradient North East Basin 6/30/2015 -- -- WG MW-13 Downgradient North East Basin 6/30/2015 24.2 21.2 WG I Downgradient North East Basin 6/30/2015 24.3 21.3 WG MW-14 Downgradient North East Basin 6/30/2015 -- -- WG Downgradient 6/23/2015 WG MW-15 Downgradient 6/29/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW-15BR Downgradient 6/23/2015 WG Downgradient 9/15/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW-15D Downgradient 6/18/2015 WG Downgradient 9/15/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG Ash Basin 6/29/2015 WG MW-1D Ash Basin 9/18/2015 720 670 WG Ash Basin 9/18/2015 710 660 -- -- WG Ash Basin 6/29/2015 -- -- 60.7 57.7 WG MW-is Ash Basin 9/18/2015 49.1 46.1 WG Ash Basin 9/18/2015 53.8 50.8 WG MW 2D Ash Basin NW Boundary 6/30/2015 -- -- -- -- WG Ash Basin NW Boundary 9/18/2015 11.5 6.5 WG MW-3D Downgradient 6/30/2015 WG Downgradient 9/16/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW-3S Downgradient 6/30/2015 WG Downgradient 1 9/16/2015 Page 9 of 20 Table 2-8 Constituents of Interest Evaluation Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin CHEMICAL -NAME CAS -RN FRACTION REPORT -RESULT -UNIT NC 2L Groundwater IMAC PPBC Boron 7440-42-8 D µg/I NS NS 50 Boron 7440-42-8 T µg/I 700 NS 50 Chromium 7440-47-3 T µg/I 10 NS 5 Chromium 7440-47-3 D µg/I NS NS 5 Chromium 7440-47-3 T µg/I 10 NS 5 Cobalt 7440-48-4 D µg/I NS NS 3 Matrix Location Location Description Sample Date Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff WG MW-4D Downgradient North East Basin 6/18/2015 WG Downgradient North East Basin 9/17/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW-4S Downgradient North East Basin 9/17/2015 15.4 12.4 WG MW-5D Downgradient North East Basin 6/18/2015 -- -- WG Downgradient North East Basin 9/17/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW-5S Downgradient North East Basin 6/25/2015 2.2 -0.8 WG Downgradient North East Basin 9/17/2015 1.6 -1.4 WG MW-6D Downgradient North East Basin 6/18/2015 -- -- WG Downgradient North East Basin 9/18/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW-6S Downgradient North East Basin 6/18/2015 WG Downgradient North East Basin 9/17/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW 7BR Side Gradient East of Ash Basin 7/10/2015 23.3 18.3 24.7 19.7 WG Side Gradient East of Ash Basin 9/15/2015 22.1 17.1 20.9 15.9 WG MW 7D Side Gradient East of Ash Basin 9/16/2015 -- -- -- -- WG Side Gradient East of Ash Basin 9/16/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW-7SR Side Gradient East of Ash Basin 9/16/2015 1.8 -1.2 WG MW-81D Side Gradient East of Ash Basin 7/1/2015 -- -- WG MW-81 Side Gradient East of Ash Basin 7/1/2015 WG MW-8S Side Gradient East of Ash Basin 6/30/2015 WG Side Gradient East of Ash Basin 7/6/2015 WG MW-9 Side Gradient East of Ash Basin 7/6/2015 WG Side Gradient East of Ash Basin 7/6/2015 WG Side Gradient East of Ash Basin 7/2/2015 WG MW-9BR Side Gradient East of Ash Basin 9/18/2015 WG Side Gradient East of Ash Basin 9/18/2015 WG Side Gradient East of Ash Basin 7/1/2015 29.4 24.4 -- -- -- -- WG Side Gradient East of Ash Basin 7/1/2015 -- -- 24.2 19.2 20 15 WG Side Gradient East of Ash Basin 7/1/2015 29.6 24.6 24.8 19.8 1 20.6 15.6 WG MW-91D Side Gradient East of Ash Basin 7/2/2015 -- -- -- -- -- -- WG Side Gradient East of Ash Basin 7/2/2015 26.3 21.3 27 22 WG Side Gradient East of Ash Basin 9/18/2015 15.6 10.6 -- -- WG I Side Gradient East of Ash Basin 9/18/2015 16.5 11.5 15.5 J+ 10.5 Notes: Orange > groundwater standard and> PPBC Green => groundwater standard but < PPBC pg/L = micrograms per liter NTU = nephelometric turbidity units SU = standard unit J- = estimated concentration, biased low J = laboratory estimated concentration J+ = estimated concentration, biased high U = results not detected 02L = standards as found in T15A NCAC 02L CAS -RN = Chemical Abstracts Service Registry Number D = dissolved IMAC = Interim Maximum Allow Concentration IN RNG = in range N = normal NS = no standard PPBC = Proposed Provisional Background Concentration Q = qualifier T = total Page 10 of 20 Table 2-8 Constituents of Interest Evaluation Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin CHEMICAL -NAME CAS -RN FRACTION REPORT -RESULT -UNIT NC 2L Groundwater IMAC PPBC Cobalt 7440-48-4 T µg/l NS 1 3 Iron 7439-89-6 D µg/1 NS NS 790 Iron 7439-89-6 T µg/I 300 NS 790 Manganese 7439-96-5 D µg/l NS NS 413 Manganese 7439-96-5 T µg/I 50 NS 413 Sulfate 14808-79-8 N µg/1 250000 NS 970 Matrix Location Location Description Sample Date Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff PW AB-3S Ash Basin 7/2/2015 1.9 -1.1 2400 1610 6500 5710 860 447 910 497 PW Ash Basin 9/17/2015 5.7 J+ 2.7 2800 2010 11400 10610 600 187 620 207 PW Ash Basin 6/28/2015 5.7 2.7 -- -- -- -- 1200 787 1200 787 PW AB-4S Ash Basin 9/17/2015 142 139 13700 J+ 12910 520 107 2300 1887 PW Ash Basin 6/20/2015 1 -2 660 -130 -- -- -- -- PW AB-5S Ash Basin 6/25/2015 -- -- -- -- PW Ash Basin 9/15/2015 5.1 2.1 2000 1210 PW Ash Basin 6/8/2015 -- -- -- -- PW AB-5SL Ash Basin 6/25/2015 PW Ash Basin 9/16/2015 PW Ash Basin 6/22/2015 13.4 10.4 11000 10210 11200 10410 1300 887 1300 887 PW AB-7S Ash Basin 6/24/2015 -- -- -- -- -- -- -- -- -- -- PW Ash Basin 9/16/2015 10.4 7.4 10000 9210 10000 9210 1200 787 1200 787 -- -- PW C-is Cinder Storage 6/17/2015 102 99 176000 175210 175000 174210 3400 2987 3200 2787 559000 558030 PW Cinder Storage 9/15/2015 387 384 107000 106210 102000 101210 10600 10187 9400 8987 934000 933030 WG AB-1D Ash Basin 7/9/2015 2.9 -0.1 -- -- 370 -420 -- -- -- -- -- -- WG Ash Basin 9/16/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG AB-1S Ash Basin 7/9/2015 15.9 12.9 510 -280 260 -153 250 -163 WG Ash Basin 9/16/2015 13.4 10.4 8100 7310 200 -213 250 -163 WG Ash Basin 7/8/2015 -- -- -- -- -- -- -- -- WG AB-21D Ash Basin 9/16/2015 - -- WG Ash Basin 9/16/2015 830 40 -- -- -- -- WG Ash Basin 7/8/2015 17.1 14.1 1700 910 310 -103 330 -83 WG AB-2S Ash Basin 9/16/2015 -- -- -- -- 830 417 -- -- WG Ash Basin 9/16/2015 26.2 23.2 2200 1410 830 417 900 487 WG Ash Basin 7/23/2015 1.64 -1.36 4440 3650 -- -- 87 -326 WG AB-3BR Ash Basin 9/17/2015 -- -- -- -- -- -- WG Ash Basin 9/17/2015 WG Ash Basin 7/7/2015 WG AB-31D Ash Basin 9/17/2015 WG Ash Basin 9/17/2015 WG AB-41D Ash Basin 7/8/2015 WG Ash Basin 9/17/2015 310 J+ -480 WG Ash Basin 6/20/2015 -- -- WG AB-51D Ash Basin 7/8/2015 WG Ash Basin 9/15/2015 -- -- WG Ash Basin 9/15/2015 470 -320 Ash Basin 6/22/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- tWG WG AB-66RU Ash Basin 7/2/2015 1.8 -1.2 970 180 WG Ash Basin 9/16/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG Ash Basin 9/16/2015 WG Ash Basin 6/22/2015 730 -60 WG AB-6S Ash Basin 7/1/2015 -- -- WG Ash Basin 9/17/2015 -- -- 170 -243 -- -- WG Ash Basin 9/17/2015 2.2 -0.8 2400 J+ 1610 170 -243 220 -193 WG Ash Basin 7/1/2015 -- -- -- -- -- -- -- -- WG Ash Basin 9/16/2015 -- -- WG AB-7D Ash Basin 9/16/2015 710 -80 WG Ash Basin 9/16/2015 -- -- WG Ash Basin 9/16/2015 690 -100 WG Ash Basin 7/7/2015 1.6 -1.4 380 -410 77 -336 85 -328 WG AB-71 Ash Basin 9/17/2015 -- -- -- -- 120 -293 -- -- WG Ash Basin 9/17/2015 2.2 -0.8 450 -340 84 -329 100 -313 WG Ash Basin 6/17/2015 -- -- -- 130 -283 140 -273 WG AB-81D Ash Basin 6/17/2015 -- - 130 -283 140 -273 WG Ash Basin 9/16/2015 1.2 -1.8 120 -293 120 -293 WG AB 8S Ash Basin 6/20/2015 -- -- -- 140 -273 150 -263 WG Ash Basin 1 9/15/2015 3.6 0.6 3500 2710 1 89 -324 120 -293 Page 11 of 20 Table 2-8 Constituents of Interest Evaluation Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin CHEMICAL —NAME CAS —RN FRACTION REPORT —RESULT —UNIT NC 2L Groundwater IMAC PPBC Cobalt 7440-48-4 T µg/I NS 1 3 Iron 7439-89-6 D µg/I NS NS 790 Iron 7439-89-6 T µg/I 300 NS 790 Manganese 7439-96-5 D µg/I NS NS 413 Manganese 7439-96-5 T µg/I 50 NS 413 Sulfate 14808-79-8 N µg/I 250000 NS 970 Matrix Location Location Description Sample Date Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff WG Ash Storage Area 6/5/2015 WG AS-1 D Ash Storage Area 7/1/2015 WG Ash Storage Area 9/8/2015 WG Ash Storage Area 9/8/2015 WG Ash Storage Area 6/5/2015 5.4 2.4 660 -130 1700 1287 1900 1487 WG AS-1 S Ash Storage Area 7/1/2015 -- -- -- -- -- -- -- -- WG Ash Storage Area 9/8/2015 -- -- -- -- 2400 1987 -- -- WG Ash Storage Area 9/8/2015 8.1 5.1 8500 7710 2300 1887 2500 2087 WG Ash Storage Area 6/8/2015 -- -- -- -- -- -- -- -- WG AS-21D Ash Storage Area 7/1/2015 WG Ash Storage Area 9/4/2015 WG Ash Storage Area 9/4/2015 WG Ash Storage Area 6/5/2015 12.4 9.4 314 -476 2090 1300 580 167 640 227 WG Ash Storage Area 7/1/2015 -- -- -- -- -- -- -- -- -- -- WG AS-2S Ash Storage Area 9/4/2015 500 -290 460 47 WG Ash Storage Area 9/4/2015 500 -290 460 47 WG Ash Storage Area 9/8/2015 -- -- -- -- 2400 1987 -- -- WG Ash Storage Area 9/4/2015 24.3 21.3 500 -290 9000 8210 460 47 810 397 WG Ash Storage Area 6/5/2015 -- -- -- -- -- -- -- -- -- -- WG Ash Storage Area 7/1/2015 WG AS-31D Ash Storage Area 9/4/2015 WG Ash Storage Area 9/4/2015 WG Ash Storage Area 9/4/2015 WG Ash Storage Area 9/4/2015 10000 J 9210 1700 J 1287 WG Ash Storage Area 7/7/2015 -- -- -- -- -- -- WG Ash Storage Area 9/4/2015 570 157 WG AS-3S Ash Storage Area 9/8/2015 -- -- 1100 310 -- -- 660 247 -- -- WG Ash Storage Area 9/4/2015 16.1 13.1 -- -- 13100 J+ 12310 570 157 1800 J+ 1387 WG Ash Storage Area 9/8/2015 10.1 7.1 540 -250 12000 11210 450 37 1400 987 WG Ash Storage Area 7/7/2015 -- -- -- -- 990 200 720 307 730 317 WG AS-3SA Ash Storage Area 9/4/2015 -- -- -- -- 1200 787 -- -- WG Ash Storage Area 9/4/2015 10.8 7.8 -- -- 1200 787 1100 J+ 687 WG CSA Background (sidegradient) 7/11/2015 2.9 -0.1 11700 10910 -- -- 210 -203 WG BG-11D CSA Background (sidegradient) 7/11/2015 1.3 -1.7 1500 710 -- -- WG CSA Background (sidegradient) 9/18/2015 1.8 -1.2 3600 2810 -- -- 72 -341 WG BG-1S CSA Background (sidegradient) 7/6/2015 3 0 2200 1410 240 -173 300 -113 WG CSA Background (sidegradient) 9/17/2015 1.3 -1.7 -- -- 100 -313 96 -317 WG CSA Background (sidegradient) 7/17/2015 -- -- -- -- -- -- -- -- -- -- -- -- WG BG-2BR CSA Background (sidegradient) 7/17/2015 760 J -30 WG CSA Background (sidegradient) 9/17/2015 310 -480 WG BG 2D CSA Background (sidegradient) 7/11/2015 -- WG CSA Background (sidegradient) 9/17/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG 2S CSA Background (sidegradient) 7/10/2015 360 -53 370 -43 WG-1BG CSA Background (sidegradient) 9/17/2015 -- -- 340 -73 310 -103 WG BG-3D CSA Background (sidegradient) 7/6/2015 930 140 -- -- 63 -350 WG CSA Background (sidegradient) 9/17/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG BG-3S CSA Background (sidegradient) 6/30/2015 240 -173 240 -173 WG CSA Background (sidegradient) 9/17/2015 520 107 560 147 WG C-1 BRU Cinder Storage 9/15/2015 -- -- -- -- WG Cinder Storage 6/19/2015 WG Cinder Storage 6/25/2015 WG C-2 D Cinder Storage 9/18/2015 WG Cinder Storage 9/18/2015 WG Cinder Storage 9/18/2015 WG Cinder Storage 9/18/2015 -- -- -- -- WG Cinder Storage 6/19/2015 39.7 36.7 580 167 600 187 Cinder Storage 6/25/2015 -- - -- -- WG C-2S Cinder Storage 9/17/2015 -- -- 600 187 UWG WG Cinder Storage 9/17/2015 37.9 34.9 1400 610 600 187 560 147 WG Cinder Storage 9/17/2015 -- -- -- 610 197 -- Page 12 of 20 Table 2-8 Constituents of Interest Evaluation Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin CHEMICAL -NAME CAS -RN FRACTION REPORT -RESULT -UNIT NC 2L Groundwater IMAC PPBC Cobalt 7440-48-4 T µg/I NS 1 3 Iron 7439-89-6 D µg/I NS NS 790 Iron 7439-89-6 T µg/I 300 NS 790 Manganese 7439-96-5 D µg/I NS NS 413 Manganese 7439-96-5 T µg/I 50 NS 413 Sulfate 14808-79-8 N µg/I 250000 NS 970 Matrix Location Location Description Sample Date Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff WG Cinder Storage 9/17/2015 38.6 35.6 640 -150 590 177 600 187 WG GWA-10BRU Downgradient 9/16/2015 -- -- 470 -320 -- -- -- -- WG GWA-10D Downgradient 7/3/2015 -- -- -- -- -- -- -- -- WG GWA-10S Downgradient 7/2/2015 10 7 -- -- -- -- 240 -173 250 -163 WG Downgradient 9/16/2015 11 8 890 100 1200 410 420 7 410 -3 WG GWA-1 BRU Downgradient 9/16/2015 -- -- -- -- -- -- -- -- -- -- WG GWA-1 D Downgradient NW 7/2/2015 -- -- 720 -70 -- -- WG GWA-1S Downgradient NW 7/2/2015 2.1 -0.9 1800 1010 110 -303 WG Downgradient NW 9/16/2015 1.3 -1.7 1600 810 67 -346 WG GWA-20BR Ash Storage Upgradient 7/27/2015 -- -- -- -- -- -- WG jAsh Storage Upgradient 9/19/2015 1.8 -1.2 1200 410 WG Ash Storage Upgradient 7/16/2015 1.9 -1.1 660 -130 376000 J+ 375030 WG GWA-20D Ash Storage Upgradient 9/19/2015 -- -- 620 -170 -- -- -- -- 400000 399030 WG GWA-20S Ash Storage Upgradient 7/11/2015 12.7 9.7 9500 8710 150 -263 320 -93 -- -- WG Ash Storage Upgradient 9/16/2015 2.1 -0.9 320 -470 87 -326 89 -324 WG Upgradient 8/27/2015 -- -- -- -- -- -- -- -- WG Upgradient 8/27/2015 1.2 -1.8 1600 810 62 -351 WG GWA-21BR Upgradient 9/15/2015 -- - -- -- -- -- WG Upgradient 9/17/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG Upgradient 9/15/2015 WG Upgradient 9/17/2015 WG GWA-21 D Upgradient 9/18/2015 600 -190 -- -- -- -- WG Upgradient 9/18/2015 2.5 -0.5 -- -- 5200 4410 -- -- 120 -293 WG Upgradient 8/14/2015 4 1 -- -- 550 137 660 247 WG GWA-21S Upgradient 9/16/2015 -- -- -- -- 440 27 -- -- WG Upgradient 9/16/2015 4.8 1.8 2600 1810 440 27 440 27 WG GWA-22BR Ash Storage Upgradient 7/21/2015 -- -- -- -- -- -- -- -- WG Ash Storage Upgradient 9/18/2015 -- -- -- -- -- -- WG GWA-22D Ash Storage Upgradient 7/10/2015 3.4 0.4 2600 1810 120 -293 WG Ash Storage Upgradient 9/17/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG GWA-22S Ash Storage Upgradient 7/10/2015 1.3 -1.7 -- -- -- -- WG Ash Storage Upgradient 9/16/2015 1.2 -1.8 5600 4810 320 -93 WG Ash Storage Upgradient 7/17/2015 -- -- -- -- -- -- WG GWA-23BR Ash Storage Upgradient 7/17/2015 WG Ash Storage Upgradient 9/19/2015 860 70 -- -- -- -- -- -- -- -- -- -- -- -- WG Ash Storage Upgradient 9/19/2015 -- -- 860 70 WG Ash Storage Upgradient 7/16/2015 -- -- WG GWA-23D Ash Storage Upgradient 9/18/2015 WG Ash Storage Upgradient 9/18/2015 -- -- -- -- -- -- WG Ash Storage Upgradient 7/10/2015 3.3 0.3 530 -260 81 -332 82 -331 WG GWA-23S Ash Storage Upgradient 9/16/2015 -- -- -- -- 86 -327 -- -- WG Ash Storage Upgradient 9/16/2015 3.2 0.2 86 -327 82 -331 WG GWA-2BR Downgradient of Ash Basin 6/17/2015 -- -- -- -- -- -- -- -- WG Downgradient of Ash Basin 9/17/2015 1300 510 60 -353 WG Downgradient of Ash Basin 7/8/2015 -- -- -- -- WG GWA-2BRU Downgradient of Ash Basin 7/9/2015 -- -- -- -- WG Downgradient of Ash Basin 7/10/2015 1500 710 61 -352 WG Downgradient of Ash Basin 9/17/2015 -- -- -- -- -- -- WG GWA-2S Downgradient of Ash Basin 6/22/2015 590 -200 56 -357 95 -318 WG Downgradient of Ash Basin 9/18/2015 2.4 -0.6 5200 4410 -- -- 290 -123 WG GWA-3D Downgradient of Coal Pile 6/17/2015 1.1 -1.9 -- -- 11600 11187 9200 8787 1310000 1309030 WG Downgradient of Coal Pile 9/15/2015 1.4 -1.6 -- -- 9500 9087 12100 11687 1370000 1369030 WG GWA-3SA Downgradient of Coal Pile 7/1/2015 18.4 15.4 -- 420 -370 13600 13187 12700 12287 1420000 1419030 WG Downgradient of Coal Pile 9/15/2015 4.4 1.4 4400 3610 5000 4210 13500 13087 13100 12687 1280000 1279030 WG Upgradient of Ash Storage 7/27/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG GWA-4BR Upgradient of Ash Storage 7/27/2015 -- -- -- -- -- -- -- -- WG Upgradient of Ash Storage 9/17/2015 -- -- -- -- -- -- -- -- -- -- WG Upgradient of Ash Storage 7/10/2015 WG-1GWA-4D Upgradient of Ash Storage 9/17/2015 WG I r-�nio_ac Upgradient of Ash Storage 7/10/2015 1.7 -1.3 92 -321 120 -293 Page 13 of 20 Table 2-8 Constituents of Interest Evaluation Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin CHEMICAL —NAME CAS —RN FRACTION REPORT —RESULT —UNIT NC 2L Groundwater IMAC PPBC Cobalt 7440-48-4 T µg/I NS 1 3 Iron 7439-89-6 D µg/I NS NS 790 Iron 7439-89-6 T µg/I 300 NS 790 Manganese 7439-96-5 D µg/I NS NS 413 Manganese 7439-96-5 T µg/I 50 NS 413 Sulfate 14808-79-8 N µg/I 250000 NS 970 Matrix Location Location Description Sample Date Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff WG Upgradient of Ash Storage 9/17/2015 3.6 0.6 4500 3710 130 -283 240 -173 WG GWA-51D Upgradient of Ash Storage 7/11/2015 -- -- -- -- -- -- -- -- WG Upgradient of Ash Storage 9/16/2015 1.1 -1.9 1600 810 -- -- 120 -293 WG GWA-5S Upgradient of Ash Storage 6/18/2015 4.5 1.5 -- -- 200 -213 190 -223 WG Upgradient of Ash Storage 6/19/2015 -- -- -- -- -- -- -- -- -- -- -- WG GWA-6D Upgradient of Ash Storage 6/24/2015 WG Upgradient of Ash Storage 9/18/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG Upgradient of Ash Storage 9/18/2015 -- -- 800 10 -- -- -- -- WG Upgradient of Ash Storage 6/19/2015 27.6 24.6 1100 310 1100 687 1300 887 WG GWA-6S Upgradient of Ash Storage 6/25/2015 -- -- -- -- -- WG Upgradient of Ash Storage 9/18/2015 -- -- -- -- 1200 787 WG Upgradient of Ash Storage 9/18/2015 27.1 24.1 2500 1710 1300 887 1400 987 WG Side Gradient of Ash Basin East 7/7/2015 -- -- -- -- -- -- -- -- WG GWA-7BR Side Gradient of Ash Basin East 9/15/2015 WG Side Gradient of Ash Basin East 9/15/2015 WG Side Gradient of Ash Basin East 6/17/2015 440 -350 WG GWA-7D Side Gradient of Ash Basin East 9/15/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG GWA-7S Side Gradient of Ash Basin East 6/19/2015 790 0 -- -- -- -- WG GWA-8D Side Gradient of Ash Basin East 6/28/2015 1300 510 69 -344 96 -317 WG Side Gradient of Ash Basin East 9/18/2015 820 30 -- -- -- -- -- -- -- -- -- WG GWA-8S Side Gradient of Ash Basin East 6/28/2015 66.8 63.8 -- -- 760 347 720 307 WG Side Gradient of Ash Basin East 9/18/2015 33.8 30.8 -- -- 390 23 390 23 WG GWA-9BR Side Gradient of Ash Basin East 7/10/2015 -- -- 450 -340 -- -- -- -- WG Side Gradient of Ash Basin East 7/1/2015 83 -330 90 -323 WG GWA-9D Side Gradient of Ash Basin East 9/16/2015 -- -- -- -- WG Side Gradient of Ash Basin East 9/16/2015 -- -- -- -- WG Side Gradient of Ash Basin East 6/30/2015 50.1 47.1 3000 2587 2900 2487 WG GWA-9S Side Gradient of Ash Basin East 9/16/2015 -- -- 2700 2287 -- -- WG Side Gradient of Ash Basin East 9/16/2015 45.9 42.9 2600 2187 2700 2287 WG Side Gradient Northwest 6/23/2015 -- -- -- -- -- -- WG MW-10 Side Gradient Northwest 6/23/2015 WG Side Gradient Northwest 6/29/2015 WG Side Gradient Northwest 7/2/2015 WG MW-11DR Side Gradient Northwest 7/2/2015 WG Side Gradient Northwest 7/2/2015 WG Downgradient North East Basin 6/30/2015 WG MW-13 Downgradient North East Basin 6/30/2015 24.1 21.1 15100 14310 16000 15210 8600 8187 8500 8087 WG Downgradient North East Basin 6/30/2015 23.7 20.7 15000 14210 15700 14910 8700 8287 8300 7887 WG MW-14 Downgradient North East Basin 6/30/2015 -- -- -- -- -- -- -- -- -- -- WG Downgradient 6/23/2015 1.3 -1.7 WG MW-15 Downgradient 6/29/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW-15BR Downgradient 6/23/2015 WG Downgradient 9/15/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW-15D Downgradient 6/18/2015 WG Downgradient 9/15/2015 430 -360 -- -- -- -- -- -- -- -- -- WG Ash Basin 6/29/2015 -- -- 430 17 530 117 WG MW-1D Ash Basin 9/18/2015 460 47 -- -- WG Ash Basin 9/18/2015 -- -- 460 47 380 -33 WG Ash Basin 6/29/2015 61 58 30600 29810 30800 30010 2600 2187 2600 2187 WG MW-is Ash Basin 9/18/2015 -- -- 29400 28610 -- -- 2300 1887 -- -- WG Ash Basin 9/18/2015 58.6 55.6 30500 29710 29400 28610 2500 2087 2100 1687 WG MW 2D Ash Basin NW Boundary 6/30/2015 -- -- -- -- -- -- -- -- WG Ash Basin NW Boundary 9/18/2015 1.3 -1.7 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW-3D Downgradient 6/30/2015 -- -- WG Downgradient 9/16/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW-3S Downgradient 6/30/2015 53 -360 68 -345 WG Downgradient 9/16/2015 2.6 1 1 -0.4 1 720 -70 450 1 37 1700 1287 Page 14 of 20 Table 2-8 Constituents of Interest Evaluation Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin CHEMICAL -NAME CAS -RN FRACTION REPORT -RESULT -UNIT NC 2L Groundwater IMAC PPBC Cobalt 7440-48-4 T µg/I NS 1 3 Iron 7439-89-6 D µg/I NS NS 790 Iron 7439-89-6 T µg/I 300 NS 790 Manganese 7439-96-5 D µg/I NS NS 413 Manganese 7439-96-5 T µg/I 50 NS 413 Sulfate 14808-79-8 N µg/I 250000 NS 970 Matrix Location Location Description Sample Date Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff WG MW-4D Downgradient North East Basin 6/18/2015 WG Downgradient North East Basin 9/17/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW-4S Downgradient North East Basin 9/17/2015 19 16 990 200 280 -133 240 -173 WG MW-5D Downgradient North East Basin 6/18/2015 -- -- -- -- -- -- -- -- WG Downgradient North East Basin 9/17/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW-5S Downgradient North East Basin 6/25/2015 1.9 -1.1 WG Downgradient North East Basin 9/17/2015 1.7 -1.3 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW-6D Downgradient North East Basin 6/18/2015 -- -- WG Downgradient North East Basin 9/18/2015 0.5 U ND -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW-6S Downgradient North East Basin 6/18/2015 0.2 J -2.8 WG Downgradient North East Basin 9/17/2015 0.19 J -2.81 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW 7BR Side Gradient East of Ash Basin 7/10/2015 0.5 U ND WG Side Gradient East of Ash Basin 9/15/2015 0.5 U ND -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW 7D Side Gradient East of Ash Basin 9/16/2015 0.5 U ND WG Side Gradient East of Ash Basin 9/16/2015 0.5 U ND -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW-7SR Side Gradient East of Ash Basin 9/16/2015 2.2 -0.8 1400 610 6500 5710 62 -351 110 -303 WG MW-81D Side Gradient East of Ash Basin 7/1/2015 1.1 -1.9 -- -- 2700 1910 -- -- -- -- WG MW-81 Side Gradient East of Ash Basin 7/1/2015 0.76 -2.24 2100 1310 -- -- -- -- WG MW-8S Side Gradient East of Ash Basin 6/30/2015 0.23 J -2.77 -- -- 54 -359 57 -356 WG Side Gradient East of Ash Basin 7/6/2015 -- -- -- -- -- WG MW-9 Side Gradient East of Ash Basin 7/6/2015 0.76 -2.24 WG Side Gradient East of Ash Basin 7/6/2015 0.87 -2.13 WG Side Gradient East of Ash Basin 7/2/2015 0.5 U ND WG MW-9BR Side Gradient East of Ash Basin 9/18/2015 WG Side Gradient East of Ash Basin 9/18/2015 0.5 U ND WG Side Gradient East of Ash Basin 7/1/2015 WG Side Gradient East of Ash Basin 7/1/2015 0.5 U ND WG Side Gradient East of Ash Basin 7/1/2015 0.5 U ND WG MW-91D Side Gradient East of Ash Basin 7/2/2015 WG Side Gradient East of Ash Basin 7/2/2015 0.5 U ND WG Side Gradient East of Ash Basin 9/18/2015 -- WG Side Gradient East of Ash Basin 9/18/2015 0.5 U ND Notes: Orange > groundwater standard and> PPBC Green => groundwater standard but < PPBC pg/L = micrograms per liter NTU = nephelometric turbidity units SU = standard unit J- = estimated concentration, biased low J = laboratory estimated concentration J+ = estimated concentration, biased high U = results not detected 02L = standards as found in T15A NCAC 02L CAS -RN = Chemical Abstracts Service Registry Number D = dissolved IMAC = Interim Maximum Allow Concentration IN RNG = in range N = normal NS = no standard PPBC = Proposed Provisional Background Concentration Q = qualifier T = total Page 15 of 20 Table 2-8 Constituents of Interest Evaluation CHEMICAL -NAME CAS -RN FRACTION REPORT -RESULT -UNIT NC 2L Groundwater IMAC PPBC Thallium 7440-28-0 D µg/I NS NS 0.2 Thallium 7440-28-0 T µg/I NS 0.2 0.2 Total Dissolved Solids TDS N µg/I 500000 NS 120000 Vanadium 7440-62-2 D µg/I NS NS 29.9 Vanadium 7440-62-2 T µg/I NS 0.3 29.9 Matrix Location Location Description Sample Date Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff PW AB-3S Ash Basin 7/2/2015 -- -- 6 -23.9 11.3 -18.6 PW Ash Basin 9/17/2015 0.23 J+ 0.03 0.55 J -29.35 35.5 J+ 5.6 PW Ash Basin 6/28/2015 -- -- -- -- 166 136.1 PW AB-4S Ash Basin 9/17/2015 0.72 0.52 92.1 62.2 609 579.1 PW Ash Basin 6/20/2015 0.36 0.16 0.48 0.28 200 170.1 231 201.1 PW AB-5S Ash Basin 6/25/2015 -- -- -- -- -- -- -- -- PW Ash Basin 9/15/2015 0.65 0.45 285 255.1 257 227.1 PW Ash Basin 6/8/2015 -- -- 130 100.1 151 121.1 PW AB-5SL Ash Basin 6/25/2015 -- -- -- -- PW Ash Basin 9/16/2015 95.9 66 84.4 54.5 PW Ash Basin 6/22/2015 0.23 0.03 -- -- 1.1 -28.8 PW AB-7S Ash Basin 6/24/2015 -- -- -- -- -- -- PW Ash Basin 9/16/2015 0.23 0.03 0.25 0.05 -- -- -- -- 8.7 -21.2 PW C-is Cinder Storage 6/17/2015 -- -- -- -- 1110000 990000 2.7 -27.2 4 -25.9 PW Cinder Storage 9/15/2015 1770000 1650000 3.9 -26 6.5 -23.4 WG AB-1D Ash Basin 7/9/2015 -- -- 11.5 -18.4 20 -9.9 WG Ash Basin 9/16/2015 8.7 -21.2 7.7 -22.2 WG AB-1S Ash Basin 7/9/2015 1.8 -28.1 WG Ash Basin 9/16/2015 1.5 -28.4 WG Ash Basin 7/8/2015 31.1 1.2 32.4 2.5 WG AB-21D Ash Basin 9/16/2015 8.6 -21.3 -- -- WG FAsh Basin 9/16/2015 8.9 -21 9.4 -20.5 WG Ash Basin 7/8/2015 -- -- 3.8 -26.1 WG AB-2S Ash Basin 9/16/2015 -- -- WG Ash Basin 9/16/2015 -- -- 4.1 -25.8 WG Ash Basin 7/23/2015 19 -10.9 32.1 2.2 WG AB-3BR Ash Basin 9/17/2015 21.3 -8.6 -- -- WG Ash Basin 9/17/2015 -- -- 22.2 7.7 23.4 J+ 6.5 WG Ash Basin 7/7/2015 946000 826000 7.4 -22.5 11.5 -18.4 WG AB-31D Ash Basin 9/17/2015 -- -- 12.8 -17.1 -- -- WG Ash Basin 9/17/2015 630000 510000 13.5 -16.4 13.8 J+ -16.1 WG AB-4D Ash Basin 7/8/2015 -- -- 24.1 -5.8 24 -5.9 WG Ash Basin 9/17/2015 16 -13.9 16.3 -13.6 WG Ash Basin 6/20/2015 12.7 -17.2 12.5 -17.4 WG AB-51D Ash Basin 7/8/2015 -- -- -- -- WG Ash Basin 9/15/2015 12.5 -17.4 -- -- WG Ash Basin 9/15/2015 12.6 -17.3 13.7 -16.2 Ash Basin 6/22/2015 12.1 -17.8 11.9 -18 tWG WG AB-66RU Ash Basin 7/2/2015 11.4 -18.5 18.6 -11.3 WG Ash Basin 9/16/2015 9.3 -20.6 WG Ash Basin 9/16/2015 9.3 -20.6 8.9 -21 WG Ash Basin 6/22/2015 24.3 -5.6 25.2 -4.7 WG AB-6S Ash Basin 7/1/2015 -- -- -- -- WG Ash Basin 9/17/2015 7.4 -22.5 -- -- WG Ash Basin 9/17/2015 7.2 -22.7 15.3 -14.6 WG Ash Basin 7/1/2015 41.1 11.2 40.5 10.6 WG Ash Basin 9/16/2015 48.1 18.2 -- -- WG AB-7D Ash Basin 9/16/2015 47.7 17.8 46.9 17 WG Ash Basin 9/16/2015 43.5 13.6 -- -- WG Ash Basin 9/16/2015 44.8 14.9 45.9 16 WG Ash Basin 7/7/2015 -- -- -- -- WG AB-71 Ash Basin 9/17/2015 0.39 J -29.51 -- -- WG Ash Basin 9/17/2015 -- -- 0.47 J -29.43 WG Ash Basin 6/17/2015 2.3 -27.6 2.7 -27.2 WG AB-8D Ash Basin 6/17/2015 2.3 -27.6 2.2 -27.7 WG Ash Basin 9/16/2015 1.3 -28.6 3.7 -26.2 WG AB-8S Ash Basin 6/20/2015 0.37 J -29.53 0.79 J -29.11 WG Ash Basin 9/15/2015 -- I -- -- 20.2 1 -9.7 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Page 16 of 20 Table 2-8 Constituents of Interest Evaluation CHEMICAL -NAME CAS -RN FRACTION REPORT -RESULT -UNIT NC 2L Groundwater IMAC PPBC Thallium 7440-28-0 D µg/I NS NS 0.2 Thallium 7440-28-0 T µg/I NS 0.2 0.2 Total Dissolved Solids TDS N µg/I 500000 NS 120000 Vanadium 7440-62-2 D µg/I NS NS 29.9 Vanadium 7440-62-2 T µg/I NS 0.3 29.9 Matrix Location Location Description Sample Date Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff WG Ash Storage Area 6/5/2015 13.4 -16.5 14.4 -15.5 WG AS-1 D Ash Storage Area 7/1/2015 -- -- -- -- WG Ash Storage Area 9/8/2015 16.7 -13.2 -- -- WG Ash Storage Area 9/8/2015 -- -- 16.1 -13.8 14.5 -15.4 WG Ash Storage Area 6/5/2015 750000 J- 630000 0.48 J+ -29A2 1.6 J+ -28.3 WG AS-1 S Ash Storage Area 7/1/2015 -- -- -- -- -- -- WG Ash Storage Area 9/8/2015 -- -- 0.73 J -29.17 -- -- WG Ash Storage Area 9/8/2015 789000 669000 0.73 J -29.17 7.2 J+ -22.7 WG Ash Storage Area 6/8/2015 -- -- 31.8 1.9 34.6 4.7 WG AS-2D Ash Storage Area 7/1/2015 -- -- -- -- WG Ash Storage Area 9/4/2015 39.8 9.9 -- -- WG Ash Storage Area 9/4/2015 39.5 9.6 40.2 10.3 WG Ash Storage Area 6/5/2015 -- -- 3.9 -26 WG Ash Storage Area 7/1/2015 -- -- -- -- WG AS-2S Ash Storage Area 9/4/2015 1.9 -28 WG Ash Storage Area 9/4/2015 1.9 -28 WG Ash Storage Area 9/8/2015 0.73 J -29.17 -- -- WG Ash Storage Area 9/4/2015 0.27 0.07 0.35 J -29.55 51.9 22 WG Ash Storage Area 6/5/2015 -- -- 17.2 -12.7 18.2 -11.7 WG Ash Storage Area 7/1/2015 -- -- -- -- WG AS-31D Ash Storage Area 9/4/2015 15.3 -14.6 -- -- WG Ash Storage Area 9/4/2015 15.5 -14.4 16.6 -13.3 WG Ash Storage Area 9/4/2015 14A -15.5 -- -- WG Ash Storage Area 9/4/2015 16 -13.9 17.2 -12.7 WG Ash Storage Area 7/7/2015 -- -- -- -- WG Ash Storage Area 9/4/2015 1.3 -28.6 WG AS-3S Ash Storage Area 9/8/2015 0.35 0.15 -- -- 51.5 21.6 -- -- WG Ash Storage Area 9/4/2015 -- -- 0.34 0.14 1.3 -28.6 45.5 15.6 WG Ash Storage Area 9/8/2015 0.22 0.02 0.24 0.04 -- -- 35.8 5.9 26.6 -3.3 WG Ash Storage Area 7/7/2015 -- 519000 399000 3.9 -26 4.9 -25 WG AS-3SA Ash Storage Area 9/4/2015 -- -- -- -- -- -- WG Ash Storage Area 9/4/2015 -- -- 0.4 J -29.5 WG CSA Background (sidegradient) 7/11/2015 -- -- 19.9 -10 24.2 -5.7 WG BG-1D CSA Background (sidegradient) 7/11/2015 555000 435000 20 -9.9 22 -7.9 WG CSA Background (sidegradient) 9/18/2015 504000 384000 17.6 -12.3 21.7 -8.2 WG BG-1S CSA Background (sidegradient) 7/6/2015 -- -- 5.9 -24 WG CSA Background (sidegradient) 9/17/2015 0.63 J -29.27 WG CSA Background (sidegradient) 7/17/2015 2.5 -27.4 3 -26.9 WG BG-2BR CSA Background (sidegradient) 7/17/2015 2.7 -27.2 4.6 -25.3 WG CSA Background (sidegradient) 9/17/2015 1.6 -28.3 1.7 -28.2 WG BG 2D CSA Background (sidegradient) 7/11/2015 29.2 -0.7 29.9 0 WG CSA Background (sidegradient) 9/17/2015 29.6 -0.3 33.9 4 WG BG 2S CSA Background (sidegradient) 7/10/2015 -- -- 0.35 J -29.55 WG CSA Background (sidegradient) 9/17/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG BG-3D CSA Background (sidegradient) 7/6/2015 3.1 -26.8 3.7 -26.2 WG CSA Background (sidegradient) 9/17/2015 2.4 -27.5 2.6 -27.3 WG BG-3S CSA Background (sidegradient) 6/30/2015 0.7 J+ -29.2 0.75 J+ -29.15 WG CSA Background (sidegradient) 9/17/2015 -- -- 0.33 J -29.57 WG C-1 BRU Cinder Storage 9/15/2015 2540000 2420000 -- -- 0.85 J -29.05 WG Cinder Storage 6/19/2015 -- -- 9.5 -20.4 10.9 -19 WG Cinder Storage 6/25/2015 -- -- -- -- WG C-2 D Cinder Storage 9/18/2015 6.5 -23A -- -- WG Cinder Storage 9/18/2015 7 -22.9 8 -21.9 WG Cinder Storage 9/18/2015 6.5 -23A -- -- WG Cinder Storage 9/18/2015 7.5 -22.4 8.9 -21 WG Cinder Storage 6/19/2015 -- -- 0.52 J -29.38 Cinder Storage 6/25/2015 -- -- WG C-2S Cinder Storage 9/17/2015 -- -- UWG WG Cinder Storage 9/17/2015 1.3 -28.6 WG Cinder Storage 9/17/2015 -- -- -- -- -- -- -- -- -- Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Page 17 of 20 Table 2-8 Constituents of Interest Evaluation CHEMICAL -NAME CAS -RN FRACTION REPORT -RESULT -UNIT NC 2L Groundwater IMAC PPBC Thallium 7440-28-0 D µg/I NS NS 0.2 Thallium 7440-28-0 T µg/I NS 0.2 0.2 Total Dissolved Solids TDS N µg/I 500000 NS 120000 Vanadium 7440-62-2 D µg/I NS NS 29.9 Vanadium 7440-62-2 T µg/I NS 0.3 29.9 Matrix Location Location Description Sample Date Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff WG Cinder Storage 9/17/2015 -- -- 0.87 J -29.03 WG GWA-10BRU Downgradient 9/16/2015 10.2 -19.7 10.9 -19 WG GWA-10D Downgradient 7/3/2015 7.7 -22.2 6.8 -23.1 WG GWA-10S Downgradient 7/2/2015 0.39 J -29.51 0.62 J -29.28 WG Downgradient 9/16/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG GWA-1 BRU Downgradient 9/16/2015 2 -27.9 1.9 -28 WG GWA-1 D Downgradient NW 7/2/2015 16.9 -13 21 -8.9 WG GWA-1S Downgradient NW 7/2/2015 0.86 J -29.04 7.9 -22 WG Downgradient NW 9/16/2015 2.3 -27.6 6 -23.9 WG GWA-20BR Ash Storage Upgradient 7/27/2015 3.1 -26.8 3.43 -26.47 WG jAsh Storage Upgradient 9/19/2015 -- -- -- -- 550000 430000 4.3 -25.6 4.7 -25.2 WG Ash Storage Upgradient 7/16/2015 3.1 2.9 3.2 3 2900000 2780000 0.66 J -29.24 2.1 -27.8 WG GWA-20D Ash Storage Upgradient 9/19/2015 3.3 3.1 3.1 2.9 3360000 3240000 1.9 -28 0.47 J -29.43 WG GWA-20S Ash Storage Upgradient 7/11/2015 -- -- -- -- -- -- -- 23 -6.9 WG Ash Storage Upgradient 9/16/2015 -- -- 0.44 J -29.46 WG Upgradient 8/27/2015 6.1 -23.8 6.2 -23.7 WG Upgradient 8/27/2015 5.9 -24 9.3 -20.6 WG GWA-21BR Upgradient 9/15/2015 3.8 -26.1 -- -- WG Upgradient 9/17/2015 4.6 -25.3 WG Upgradient 9/15/2015 3.6 -26.3 4 -25.9 WG Upgradient 9/17/2015 4.7 -25.2 6 -23.9 WG GWA-21 D Upgradient 9/18/2015 9.4 -20.5 -- -- WG Upgradient 9/18/2015 6.2 -23.7 10.4 -19.5 WG Upgradient 8/14/2015 -- -- -- -- WG GWA-21S Upgradient 9/16/2015 -- -- WG Upgradient 9/16/2015 -- -- 1.4 -28.5 WG GWA-22BR Ash Storage Upgradient 7/21/2015 9.95 -19.95 4.33 -25.57 WG Ash Storage Upgradient 9/18/2015 9.5 -20.4 10.3 -19.6 WG GWA-22D Ash Storage Upgradient 7/10/2015 16.1 -13.8 18.5 -11.4 WG Ash Storage Upgradient 9/17/2015 17 -12.9 17.8 -12.1 WG GWA-22S Ash Storage Upgradient 7/10/2015 -- -- -- -- WG Ash Storage Upgradient 9/16/2015 -- -- 0.51 J -29.39 WG Ash Storage Upgradient 7/17/2015 670000 550000 4.1 -25.8 4.9 -25 WG GWA-23BR Ash Storage Upgradient 7/17/2015 790000 670000 3.9 -26 5.3 -24.6 WG Ash Storage Upgradient 9/19/2015 -- -- 10.3 -19.6 WG Ash Storage Upgradient 9/19/2015 2.8 -27.1 3.3 -26.6 WG Ash Storage Upgradient 7/16/2015 31.9 2 34.1 4.2 WG GWA-23D Ash Storage Upgradient 9/18/2015 31 1.1 -- -- WG-1 Ash Storage Upgradient 9/18/2015 33.2 3.3 34.5 4.6 WG Ash Storage Upgradient 7/10/2015 -- -- -- -- WG GWA-23S Ash Storage Upgradient 9/16/2015 -- -- WG Ash Storage Upgradient 9/16/2015 -- -- 0.58 J -29.32 WG GWA-2BR Downgradient of Ash Basin 6/17/2015 12.3 -17.6 11.8 -18.1 WG Downgradient of Ash Basin 9/17/2015 3.6 -26.3 4.4 J+ -25.5 WG Downgradient of Ash Basin 7/8/2015 -- -- -- -- WG GWA-2BRU Downgradient of Ash Basin 7/9/2015 -- -- -- -- WG Downgradient of Ash Basin 7/10/2015 18100000 17980000 -- -- 4 -25.9 WG Downgradient of Ash Basin 9/17/2015 -- -- 0.86 J -29.04 1 J+ -28.9 WG GWA-2S Downgradient of Ash Basin 6/22/2015 1.1 -28.8 2.3 -27.6 WG Downgradient of Ash Basin 9/18/2015 -- -- 1.1 -28.8 7.2 -22.7 WG GWA-3D Downgradient of Coal Pile 6/17/2015 2390000 2270000 4.3 -25.6 4.6 -25.3 WG Downgradient of Coal Pile 9/15/2015 2130000 2010000 1.2 -28.7 1.4 -28.5 WG GWA-3SA Downgradient of Coal Pile 7/1/2015 23000000 22880000 0.66 J -29.24 1.3 -28.6 WG Downgradient of Coal Pile 9/15/2015 2100000 1980000 0.44 J -29.46 2.1 -27.8 WG Upgradient of Ash Storage 7/27/2015 1600000 1480000 0.655 -29.245 0.699 -29.201 WG GWA-4BR Upgradient of Ash Storage 7/27/2015 1500000 1380000 0.753 -29.147 0.9 -29 WG Upgradient of Ash Storage 9/17/2015 640000 520000 6.7 -23.2 8.5 -21.4 WG GWA-41D Upgradient of Ash Storage 7/10/2015 -- -- 2.4 -27.5 2.4 -27.5 WG Upgradient of Ash Storage 9/17/2015 3.1 -26.8 4 -25.9 WGI rriAio-ac Upgradient of Ash Storage 7/10/2015 0.37 J -29.53 0.84 J1 -29.06 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Page 18 of 20 Table 2-8 Constituents of Interest Evaluation CHEMICAL -NAME CAS -RN FRACTION REPORT -RESULT -UNIT NC 2L Groundwater IMAC PPBC Thallium 7440-28-0 D µg/I NS NS 0.2 Thallium 7440-28-0 T µg/I NS 0.2 0.2 Total Dissolved Solids TDS N µg/I 500000 NS 120000 Vanadium 7440-62-2 D µg/I NS NS 29.9 Vanadium 7440-62-2 T µg/I NS 0.3 29.9 Matrix Location Location Description Sample Date Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff WG Upgradient of Ash Storage 9/17/2015 -- -- 6.5 -23.4 WG GWA-51D Upgradient of Ash Storage 7/11/2015 13.9 -16 13.9 -16 WG Upgradient of Ash Storage 9/16/2015 19.2 -10.7 17.6 -12.3 WG GWA-5S Upgradient of Ash Storage 6/18/2015 -- -- -- -- -- -- -- WG Upgradient of Ash Storage 6/19/2015 26.9 -3 28 -1.9 WG GWA-61D Upgradient of Ash Storage 6/24/2015 -- -- -- -- -- -- -- WG Upgradient of Ash Storage 9/18/2015 21.9 -8 -- WG Upgradient of Ash Storage 9/18/2015 20.8 -9.1 22 -7.9 WG Upgradient of Ash Storage 6/19/2015 -- -- 4.8 -25.1 WG GWA-6S Upgradient of Ash Storage 6/25/2015 -- -- -- -- WG Upgradient of Ash Storage 9/18/2015 0.61 J -29.29 WG Upgradient of Ash Storage 9/18/2015 -- -- 3.2 -26.7 WG Side Gradient of Ash Basin East 7/7/2015 10.9 -19 10.9 -19 WG GWA-7BR Side Gradient of Ash Basin East 9/15/2015 11.8 -18.1 12.1 -17.8 WG Side Gradient of Ash Basin East 9/15/2015 11.6 -18.3 11.2 -18.7 WG Side Gradient of Ash Basin East 6/17/2015 11.6 -18.3 12.1 -17.8 WG GWA-7D Side Gradient of Ash Basin East 9/15/2015 -- -- 12.4 -17.5 WG GWA-7S Side Gradient of Ash Basin East 6/19/2015 -- -- 3.5 J+ -26.4 WG GWA-8D Side Gradient of Ash Basin East 6/28/2015 5.5 -24.4 5.5 -24.4 WG Side Gradient of Ash Basin East 9/18/2015 6.2 -23.7 7.2 -22.7 WG GWA-8S Side Gradient of Ash Basin East 6/28/2015 -- -- -- -- WG Side Gradient of Ash Basin East 9/18/2015 -- -- WG GWA-9BR Side Gradient of Ash Basin East 7/10/2015 -- -- 67.5 37.6 WG Side Gradient of Ash Basin East 7/1/2015 2.3 -27.6 2.8 -27.1 WG GWA-9D Side Gradient of Ash Basin East 9/16/2015 3.2 -26.7 -- -- WG Side Gradient of Ash Basin East 9/16/2015 3.2 -26.7 4.6 -25.3 WG Side Gradient of Ash Basin East 6/30/2015 0.42 J+ -29.48 0.52 J+ -29.38 WG GWA-9S Side Gradient of Ash Basin East 9/16/2015 -- -- -- WG Side Gradient of Ash Basin East 9/16/2015 -- -- -- -- WG Side Gradient Northwest 6/23/2015 0.47 J -29.43 1.4 -28.5 WG MW-10 Side Gradient Northwest 6/23/2015 0.46 J -29.44 1.2 -28.7 WG Side Gradient Northwest 6/29/2015 -- -- -- -- WG Side Gradient Northwest 7/2/2015 -- -- 2.1 -27.8 WG MW-11DR Side Gradient Northwest 7/2/2015 1.3 -28.6 1.3 -28.6 WG Side Gradient Northwest 7/2/2015 1.3 -28.6 1.4 -28.5 WG Downgradient North East Basin 6/30/2015 -- WG MW-13 Downgradient North East Basin 6/30/2015 WG Downgradient North East Basin 6/30/2015 -- WG MW-14 Downgradient North East Basin 6/30/2015 2.6 J+ -27.3 2.6 J+ -27.3 WG Downgradient 6/23/2015 -- -- 2.7 -27.2 WG MW-15 Downgradient 6/29/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW-15BR Downgradient 6/23/2015 2.1 -27.8 2.2 -27.7 WG Downgradient 9/15/2015 2.2 -27.7 2.6 -27.3 WG MW-15D Downgradient 6/18/2015 23.6 -6.3 22.4 -7.5 WG Downgradient 9/15/2015 9.7 -20.2 11 -18.9 WG Ash Basin 6/29/2015 1.9 J+ -28 2.1 J+ -27.8 WG MW-1D Ash Basin 9/18/2015 1.5 -28.4 -- -- WG Ash Basin 9/18/2015 1.5 -28.4 1.6 -28.3 WG Ash Basin 6/29/2015 -- -- -- -- WG MW-1S Ash Basin 9/18/2015 WG Ash Basin 9/18/2015 -- -- -- -- WG MW 2D Ash Basin NW Boundary 6/30/2015 4.5 -25.4 4.7 -25.2 WG Ash Basin NW Boundary 9/18/2015 4.1 -25.8 6.6 -23.3 WG MW-3D Downgradient 6/30/2015 5.8 -24.1 6.2 -23.7 WG Downgradient 9/16/2015 5.6 -24.3 5.7 -24.2 WG MW-3S Downgradient 6/30/2015 0.54 J+ -29.36 0.6 J+ -29.3 WG Downgradient 9/16/2015 0.42 J -29.48 0.45 J -29.45 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Page 19 of 20 Table 2-8 Constituents of Interest Evaluation CHEMICAL -NAME CAS -RN FRACTION REPORT -RESULT -UNIT NC 2L Groundwater IMAC PPBC Thallium 7440-28-0 D µg/I NS NS 0.2 Thallium 7440-28-0 T µg/I NS 0.2 0.2 Total Dissolved Solids TDS N µg/I 500000 NS 120000 Vanadium 7440-62-2 D µg/I NS NS 29.9 Vanadium 7440-62-2 T µg/I NS 0.3 29.9 Matrix Location Location Description Sample Date Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff Result Q PPBC_Diff WG MW-4D Downgradient North East Basin 6/18/2015 -- -- 1.1 -28.8 WG Downgradient North East Basin 9/17/2015 0.58 J -29.32 0.58 J -29.32 WG MW-4S Downgradient North East Basin 9/17/2015 -- -- 1.5 -28.4 WG MW-5D Downgradient North East Basin 6/18/2015 8.5 -21.4 8.6 -21.3 WG Downgradient North East Basin 9/17/2015 7.5 -22.4 7.4 -22.5 WG MW-5S Downgradient North East Basin 6/25/2015 0.53 J -29.37 -- -- WG Downgradient North East Basin 9/17/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW-6D Downgradient North East Basin 6/18/2015 3.7 -26.2 3.8 -26.1 WG Downgradient North East Basin 9/18/2015 3.4 -26.5 3.7 -26.2 WG MW-6S Downgradient North East Basin 6/18/2015 0.3 J -29.6 0.35 J -29.55 WG Downgradient North East Basin 9/17/2015 0.37 J -29.53 0.34 J -29.56 WG MW 7BR Side Gradient East of Ash Basin 7/10/2015 1180000 1060000 2.1 -27.8 2.1 -27.8 WG Side Gradient East of Ash Basin 9/15/2015 1590000 1470000 0.95 J -28.95 1.2 -28.7 WG MW 7D Side Gradient East of Ash Basin 9/16/2015 -- -- -- -- -- WG Side Gradient East of Ash Basin 9/16/2015 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- WG MW-7SR Side Gradient East of Ash Basin 9/16/2015 0.53 J -29.37 7.4 -22.5 WG MW-81D Side Gradient East of Ash Basin 7/1/2015 1.2 -28.7 4.1 -25.8 WG MW-81 Side Gradient East of Ash Basin 7/1/2015 0.94 J -28.96 2.8 -27.1 WG MW-8S Side Gradient East of Ash Basin 6/30/2015 0.45 J+ -29.45 0.32 J+ -29.58 WG Side Gradient East of Ash Basin 7/6/2015 -- -- -- -- WG MW-9 Side Gradient East of Ash Basin 7/6/2015 1.9 J+ -28 2.4 -27.5 WG Side Gradient East of Ash Basin 7/6/2015 2.1 J+ -27.8 2.7 -27.2 WG Side Gradient East of Ash Basin 7/2/2015 7.8 -22.1 7.8 -22.1 WG MW-9BR Side Gradient East of Ash Basin 9/18/2015 3.8 -26.1 -- -- WG Side Gradient East of Ash Basin 9/18/2015 3.9 -26 4 -25.9 WG Side Gradient East of Ash Basin 7/1/2015 -- -- -- -- WG Side Gradient East of Ash Basin 7/1/2015 12.4 -17.5 12.2 -17.7 WG Side Gradient East of Ash Basin 7/1/2015 11.7 -18.2 12.5 -17.4 WG MW-9D Side Gradient East of Ash Basin 7/2/2015 -- -- -- WG Side Gradient East of Ash Basin 7/2/2015 12.5 -17.4 12.8 -17.1 WG ISide Gradient East of Ash Basin 9/18/2015 16.3 -13.6 -- WG Side Gradient East of Ash Basin 9/18/2015 16.2 13.7 16.3 -13.6 Notes: Orange > groundwater standard and> PPBC Green => groundwater standard but < PPBC pg/L = micrograms per liter NTU = nephelometric turbidity units SU = standard unit J- = estimated concentration, biased low J = laboratory estimated concentration J+ = estimated concentration, biased high U = results not detected 02L = standards as found in T15A NCAC 02L CAS -RN = Chemical Abstracts Service Registry Number D = dissolved IMAC = Interim Maximum Allow Concentration IN RNG = in range N = normal NS = no standard PPBC = Proposed Provisional Background Concentration Q = qualifier T = total Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Page 20 of 20 Table 2-9 Surface Water and Areas of Wetness Sample Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: RBSW001 RBSW001 RBSW002 RBSW002 S-13 SW-3 SW-3 Round 1 Round 1 Round 1 Round 1 Round 1 Round 1 Round 2 7/9/2015 7/15/2015 7/9/2015 7/15/2015 7/7/2015 6/25/2015 9/19/2015 N N N N N N N RBSW001 RBSW001 RBSW002 RBSW002 S-13 SW-3 RV-SW-3-NS-3Q15 Constituent CAS RN Fraction Criteria Min (range only) Class Water Supply Surface Water Criteria* Criteria Source Unit Aluminum 7429-90-5 D pg/L 100 U 120 100 U 100 U 100 U Aluminum 7429-90-5 T 87 p /L 57 J - 230 - 130 310 130 Antimony 7440-36-0 D p /L 0.5 U - 0.16 J - 0.5 U 0.5 U 0.5 U Antimony 7440-36-0 T 5.6 p /L 0.2 J - 0.5 UJ - 0.5 U 0.5 U 0.5 U Arsenic 7440-38-2 D 150 pg/L 1.1 - 1.1 - 0.19 J 0.93 0.31 J Arsenic 7440-38-2 T 10 p /L 1.5 - 1.3 - 0.3 J 2.4 0.56 Barium 7440-39-3 D p /L 12 - 29 - 16 58 73 Barium 7440-39-3 T 1000 p /L 13 - 31 - 17 76 70 Beryllium 7440-41-7 D 6.5 p /L 0.2 U - 0.2 U - 0.2 U 0.2 U 0.2 U Beryllium 7440-41-7 T p /L 0.2 U - 0.2 U - 0.2 U 0.2 U 0.2 U Boron 7440-42-8 D p /L 50 U - 39 J - 50 U 500 1000 Boron 7440-42-8 T p /L 50 U - 38 J - 50 U 530 790 Cadmium 7440-43-9 D 0.15 p /L 1.9 - 0.3 - 0.08 U 0.08 U 0.025 J Cadmium 7440-43-9 T p /L 2 - 0.32 - 0.08 U 0.033 J 0.079 J Calcium 7440-70-2 T pg/L 3530 - 12700 - 8540 57000 67200 Chromium 7440-47-3 D 11 p /L 0.5 U - 1.3 - 0.28 J 0.28 J 0.27 J Chromium 7440-47-3 T 11 pg/L 0.7 - 1.1 - 0.41 J 0.38 J 0.26 J Cobalt 7440-48-4 D 3 p /L 0.41 J - 0.22 J - 0.5 U 0.41 J 1.4 Cobalt 7440-48-4 T 3 p /L 0.43 J - 0.27 J - 0.24 J 0.61 5.8 Copper 7440-50-8 D 2.7 p /L 34.2 - 10.2 - 0.95 J 0.3 J 1.9 Copper 7440-50-8 T pg/L 35.9 - 9.8 - 0.92 J 0.86 J 0.78 J Iron 7439-89-6 D p /L 50 U - 120 - 230 50 U 66 Iron 7439-89-6 T 1000 p /L 89 - 330 - 1600 810 720 Lead 7439-92-1 D 0.54 p /L 0.34 - 0.58 - 0.1 U 0.1 U 0.16 Lead 7439-92-1 T 2.5 p /L 1.5 - 0.89 - 0.13 0.58 0.07 J Magnesium 7439-95-4 T p /L 324 - 2720 - 2580 14400 17000 Manganese 7439-96-5 D p /L 20 - 27 - 79 320 520 Manganese 7439-96-5 T 50 p /L 20 - 32 - 110 370 1700 Mercury 7439-97-6 D p /L 0.2 U - 0.2 U - - 0.2 U - Mercur 7439-97-6 T 0.012 p /L 0.2 UJ - 0.2 U - 0.000843 J+ 0.2 U 0.00203 J+ Methane 74-82-8 N pg/L 2.7 J - 0.81 J+ - 27.3 6.2 J+ 4.9 J+ Molybdenum 7439-98-7 D p /L 0.28 J - 1 - 0.13 J 11 25.7 Molybdenum 7439-98-7 T 160 pg/L 0.28 J - 0.98 - 0.15 J 10.8 21.3 Nickel 7440-02-0 D 16 p /L 0.89 - 1.3 - 0.5 UJ 2.7 2.8 Nickel 7440-02-0 T 25 p /L 1.2 - 1.1 - 0.18 J 3 5.9 Potassium 7440-09-7 T p /L 5000 U - 2810 J - 5000 U 9310 9220 Selenium 7782-49-2 D pg/L 36.4 - 6.9 - 0.5 U 0.34 J 0.5 U Selenium 7782-49-2 T 5 p /L 35.4 - 6 - 0.5 U 0.43 J 0.32 J Sodium 7440-23-5 T p /L 5000 U - 5480 - 6960 10800 10800 Strontium 7440-24-6 D p /L 23 - 120 - 79 960 1700 Strontium 7440-24-6 T 14000 p /L 23 - 120 - 79 1200 1400 Thallium 7440-28-0 D p /L 0.036 J - 0.019 J - 0.1 U 0.15 0.12 J+ Thallium 7440-28-0 T 0.24 p /L 0.1 U - 0.1 U - 0.1 U 0.22 0.097 J Vanadium 7440-62-2 D p /L 0.79 J - 2.4 - 0.52 J 1 U 1 U Vanadium 7440-62-2 T p /L 0.97 J - 2.8 - 1.4 1.2 0.41 J Zinc 7440-66-6 D 36 p /L 790 - 140 - 4.8 J 210 76 Zinc 7440-66-6 T 120 p /L 750 - 140 - 3 J 220 120 Total Dissolved Solids TDS N 250000 p /L 32000 - 92000 - 83000 332000 475000 Total Organic Carbon TOC N pg/L 2800 3500 2100 2700 3600 Total Suspended Solids TSS N p /L 2500 U - 8900 - 7000 2500 U 57100 Page 1 of 2 Table 2-9 Surface Water and Areas of Wetness Sample Analytical Results - Round 1 and Round 2 Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Location: Event: Sample Date: Sample Type Code: Sample Name/ID: RBSW001 RBSW001 RBSW002 RBSW002 S-13 SW-3 SW-3 Round 1 Round 1 Round 1 Round 1 Round 1 Round 1 Round 2 7/9/2015 7/15/2015 7/9/2015 7/15/2015 7/7/2015 6/25/2015 9/19/2015 N N N N N N N RBSW001 RBSW001 RBSW002 RBSW002 S-13 SW-3 RV-SW-3-NS-3Q15 Constituent CAS RN Fraction Criteria Min (range only) Class Water Supply Surface Water Criteria* Criteria Source Unit Alkalinity, CO3 ALK-CO3 N pg/L 5000 U 5000 U 5000 U 5000 U 5000 U Alkalinity, HCO3 ALK-HCO3 N p /L 2500 J - 24600 - 39600 106000 145000 Alkalinity, lab ALK-LAB N 100000 p /L 2500 J - 24600 - 39600 106000 145000 Chloride 16887-00-6 N 230000 p /L 1000 U - 4100 - 1200 5500 7700 Nitrogen, NO2 plus NO3 NO2-NO3 N pg/L 1200 - 990 - 79 290 150 Sulfate 14808-79-8 N 250000 p /L 4700 - 18400 - 1000 U 119000 126000 Sulfide 18496-25-8 N p /L 100 U - 100 U - 100 U 100 U 100 U Arsenic 7440-38-2 T 10 p /L 0.5 U - 0.466 J - - - - Chromium 7440-47-3 T 11 p /L 1.09 J+ - 0.918 J+ - - - - Iron 7439-89-6 T 1000 p /L 90.3 J - 145 - - Manganese 7439-96-5 D p /L 18.5 - 20.3 - - Manganese 7439-96-5 T 50 p /L 20.8 - 28.4 - - - - As III 7784-46-5 T p /L 0.453 J+ - 0.266 J+ - - 0.284 - As V 10103-60-3 T p /L 0.5 U - 0.2 J+ - - 0.2 U - Chromium VI 18540-29-9 D DHHS pg/L - 0.02 U - 0.46 - - - Chromium VI 18540-29-9 T 11 p /L - - - - - 0.03 - Fe II 1345-25-1 T pg/L 30 UJ - 20 J- - - 14.5 J- - Fe III 1309-37-1 T p /L - - - - - 20 U - Mn II 1344-43-0 T p /L - - - - - 369 - Mn IV 1313-13-9 T p /L - - - - - 19.7 - Se IV 10102-18-8 T pg/L 4.87 J+ - 3.1 - - 0.5 U - Se VI 13410-01-0 T p /L 33 - 16.2 - - 0.27 - Dissolved Oxygen DO N 5.0 m /L - - 6 - - - - Dissolved Oxygen DO N 5.0 m /L 5.4 - - - - - - Dissolved Oxygen DO N 5.0 m /L - - - - 5.19 - 5.9 Temperature TEMP N Deg C 31.2 - 31.1 - 21.7 - 18.4 pH PH N 6.0 9.0 SU 9.1 - 8 - 6.81 - 6.4 Turbidity, field TURB N 25 NTU 15.95 - 25.47 - 12.96 - 38.9 Specific Conductivity (field SC N PS/cm 40.3 - 128.3 - 83.9 - 512.8 Oxidation Reduction Potential ORP N mV 143.4 - 209.5 - 227.4 - 36.2 = North Carolina surface water standards as specified in T15 NCAC 02B .0211 & .0216 (213 Standards) and as amended effective January Notes: pm = micron DHHS = North Carolina Department of Health and Human Services pg/L = micrograms per liter DO = dissolved oxygen pS/cm = microsiemens per centimeter GW = groundwater ft = feet GWQS = groundwater quality standard mg/L = milligrams per liter IMAC = Interim Maximum Allow Concentration mV = millivolts N = normal NTU - nephelometric turbidity units NS = no standard pCi/L = picocuries per liter T = total SU = standard unit TDS = total dissolved solids J = laboratory estimated concentration TOC = total organic carbon J- = estimated concentration, biased low J+ = estimated concentration, biased high U = results not detected at concentrations which equal the laboratory's method reporting limit 02B = North Carolina surface water standards as specified in T15 NCAC 02B .0211 and .0216 (amended effective January 2015) 02L = North Carolina groundwater standards as specified in T15A NCAC 02L D = dissolved Deg C = degree Celsius Page 2 of 2 Table 9-1 Interim Monitoring Plan Sample Locations Corrective Action Plan Part 2 Dan River Steam Station Ash Basin Well ID / Sampling Location Well Type Well Screen Length (ft) Approximate Well Total Depth (ft. bgs) Top of screen (ft. bgs) Bottom of screen (ft. bgs) GROUNDWATER AB-5S CSA 15 23 7 22 AB-5D CSA 5 45 34 39 AB-10D CSA 5 83 77 82 AB-10S CSA 15 30.5 15 30 AB-10SL CSA 5 50 43 48 AB-25BR CSA 5 149 144 149 AB-25D CSA 5 94 82 87 AB-25S CSA 15 53.5 30 45 AB-30BR CSA 5 115 109 114 AB-30D CSA 5 63 54 59 AB-30S CSA 15 31 15 30 AB-35BR CSA 5 95 81 86 AS-2D CSA 5 66 53 58 AS-4D CSA 5 42 35 40 AS-6D CSA 5 62 56 61 AS-8BR CSA 5 111 64 69 AS-8D CSA 4 61 48 52 AS-10D CSA 5 83 38 43 AS-12S CSA 10 28.9 13.9 23.9 BG-1 D Background/CSA 5 22 9 14 BG-5D Background/CSA 5 39.6 28 33 BG-5S Background/CSA 10 23 10.5 20.5 GWA-1 D CSA 5 120 114 119 GWA-1 S CSA 15 47 30 45 GWA-2D CSA 5 69 56 61 GWA-2S CSA 15 31.5 16 31 GWA-3D CSA 5 41.6 34 39 GWA-3S CSA 10 29 13.8 23.8 GWA-4D CSA 5 56 43 48 GWA-4S CSA 15 37 20 35 GWA-5BR CSA 5 63.3 55 60 GWA-6D CSA 5 43.6 29 34 GWA-6S CSA 10 20 9 19 GWA-7 D CSA 5 56 46 51 GWA-7S CSA 15 37.5 14 29 GWA-8D CSA 5 45 35 40 GWA-8S CSA 15 23 6 21 GWA-9D Background - CSA 5 74 67 72 GWA-9S Background - CSA 15 49 32 47 GWA-10D CSA 5 45 33 38 GWA-10S CSA 15 28 13 28 GWA-11 D CSA 5 41.7 29.5 34.5 GWA-11 S CSA 15 26 10 25 GWA-12S CSA/Background 10 16 6 16 GWA-12D CSA/Background 5 32 27 32 GWA-14D CSA 5 24 11.5 16.5 GWA-14S CSA 5 9 3 8 GWA-15D CSA 5 34.05 26 31 GWA-15S CSA 5 13.5 7.5 12.5 MW-9 Voluntary 10 22.6 11.94 21.94 MW-9D Voluntary 5 72 66.05 71.05 MW-10 Voluntary 10 21 10.8 20.8 MW-10D Voluntary 5 73 67.55 72.55 MW-11 Voluntary 10 24 14.39 24.39 MW-11 D Voluntary 5 56 50.82 55.82 MW-12 Voluntary 10 37 27.12 37.12 MW-12D Voluntary 5 45 39.97 44.97 MW-20D Compliance 5 44.2 39.2 44.2 MW-20S Compliance 15 22.11 7.11 22.11 MW-21 D Compliance 5 21 16.4 21.4 MW-21 S Compliance 5 12 6.56 11.56 MW-22D Compliance 5 39.11 34.11 39.11 MW-22S Compliance 10 24.86 14.86 24.86 MW-22BR CSA 5 84.9 58 63 MW-23D Background/Compliance 10 20.11 10.11 20.11 MW-23BR Background/CSA 5 61 56 61 MW-301 BR CSA 5 82.5 37 42 MW-308BR CSA 5 88 77 82 MW-310BR CSA 5 88 73 78 MW-311 BR CSA 5 133.5 120 125 MW-314BR CSA 5 99.1 69 74 MW-315BR CSA 15 104.3 59.7 74.7 MW-317BR CSA 5 109.8 83 88 MW-318D CSA 5 50 44.5 49.5 OW-303D Closure 5 88 83 88 OW-308D Closure 10 15 5 15 OW-31 OD Closure 5 24 19 24 Page 1 of 2 Table 9-1 Interim Monitoring Plan Sample Locations Corrective Action Plan Part 2 Dan River Steam Station Ash Basin Well ID / Sampling Location Well Type Well Screen Length (ft) Approximate Well Total Depth (ft. bgs) Top of screen (ft. bgs) Bottom of screen (ft. bgs) SURFACE WATER SW-1 SW NA NA NA NA SW-2 SW NA NA NA NA SW-3 SW NA NA NA NA SW-4 SW NA NA NA NA SW-5 SW NA NA NA NA SW-6 SW NA NA NA NA SW-7 SW NA NA NA NA SW-8 SW NA NA NA NA SW-9 SW NA NA NA NA SW-10 SW NA NA NA NA SW-11 SW NA NA NA NA SW-12 SW NA NA NA NA SW-13 SW NA NA NA NA AREAS OF WETNESS S-1 SP NA NA NA NA S-2 SP NA NA NA NA S-3 SP NA NA NA NA S-4 SP NA NA NA NA S-6 SP NA NA NA NA Page 2 of 2 Table 9-2 Sampling Parameters and Analytical Methods Corrective Action Plan Part 2 Riverbend Steam Station Ash Basin Analytical Method Chemical Analyte Bottle Requirement Preservative EPA 200.7 Total/Dissolved Metals - Aluminum, Barium, Boron, Calcium (total only), Iron, Lead, Magnesium, Manganese, Potassium (total only), Sodium (total only), Strontium, Zinc 2 - 250 mL HDPE Nitric Acid, Ice EPA 200.8 Dissolved Metals - Antimony, Arsenic, Beryllium, Cadmium, Chromium, Cobalt, Copper, Lead, Molybdenum, Nickel, Selenium, Thallium, Vanadium 2 - 250 mL HDPE Nitric Acid, Ice EPA 245.1 Total/Dissolved Mercury 2 - 250 mL HDPE Nitric Acid, Ice EPA 300 Chloride/Sulfate 250 mL PET Ice EPA 350.1 Ammonia 250 mL PET Sulfuric Acid, Ice EPA 353.2 Nitrate/Nitrite 125 mL PET Sulfuric Acid, Ice RSK 175 Methane 2-20 mL VOA Ice SM 2540C/D TDS/TSS 2 - 1,000 mL PET Ice SM 4500 - S21D Sulfide 125 mL PET Zinc Acetate plus Sodium Hydroxide, Ice SM 5310B TOC 3 - 40 mL glass VOA Phosphoric Acid, Ice SM2320B Alkalinity 500 mL PET Ice EPA 903.1 Modified Radium 226 1 L PET Nitric Acid, Ice EPA 904.0/SW846 9320 Modified Radium 228 1 L PET Nitric Acid, Ice SW846 6020A Total Combined Uranium 250 mL PET Nitric Acid, Ice EPA 218.7 Hexavalent Chromium 125 mL PET ISodiurn Hydroxide, Ice Page 1 of 1