1 May 22, 2015 Summary of the Effects of Fuel on the Performance of the FGD Wastewater Treatment System at Allen

and Belews Creek Steam Stations

The physical / chemical plus biological treatment system at both Allen and Belews Creek Steam Stations

were tested and designed based on the units burning bituminous Central Appalachian Coal (CAPP). A

variety of fuels have recently been used at both stations. This practice is expected to continue. Due to

the fuel changes, Duke Energy has observed variability in the characteristics of the FGD scrubber chemistry, which directly affects the performance of the wastewater treatment system.

Allen Steam Station

From February 1, 2009 until April 29, 2011, with the exception of a nine

‐ day test burn conducted from

November 30, 2010 to December 8, 2010, the coal used at Allen Steam Station was CAPP. Beginning

May 25, 2011, Illinois Basin (ILB) coal was used periodically. Prior to 2014, the use of ILB was primarily in approximately 30

‐ day intervals to test the performance of the boiler and associated equipment. As

shown in Table 1, Duke Energy believes these changes in coal resulted in elevated selenium

concentrations at the bioreactor effluent. Due to overlapping cyclic operations and use of ILB coal, it is

unknown whether the biological system would—given adequate time ‐‐ adapt to reduce selenium to

concentrations previously observed when 100% CAPP coal was used. As an example, ILB coal was used during the period of January 18, 2013 to February 18, 2013. The selenium concentrations in the

bioreactor effluent increased to 27.6 μg/L on 1/23/2013 and stayed above the proposed monthly

average limit of 10 ug/l until 2/8/2013, a period of more than 2 weeks. The selenium concentration in

the effluent did decrease; however, during this same period, the load on the units decreased. So, in this

instance it is unclear whether the system adapted to remove selenium or reduction in load allowed the

system to obtain lower selenium concentrations. In any event, even if the biological system can adapt to

a coal switch given enough time, the facility would be out of compliance during the period of adaptation.

Additionally, it is clear, based on our data, that coal changes can cause elevated selenium in the

bioreactor effluent. These changes are more evident beginning in 2014 through February 2015 with the

increased use of ILB coal (see Table 2). In 2014, Units 3 and 5 primarily used 100% ILB coal and Unit 4

used ILB coal on occasion. The FGD wastewater from all the units is combined prior to treatment. As

shown in the attached table, both the cyclic operations and fuel changes were potential factors of the

elevated selenium concentrations on 2/26/14 (38.5 μg/L) and 1/28/15 (38.4 μg/L). However, the

elevated selenium concentration of 50.6 μg/L observed on 2/23/15 appears to be based solely on the

fuel change.

It is also important to note that changes in the characteristics of the fuel can affect the performance of

the treatment system (see Table 3). As an example, CAPP was being used in November and December

2012; however, the SO2 in the coal (% as received and lb/MMbtu) increased on 11/25/2012 through 11/30/2012. Duke Energy believes the increase in SO2 caused the elevated selenium concentrations in

the bioreactor effluent on 11/26/2012 (17.2 μg/L) and 12/16/2012 (24.7 μg/L).2 May 22, 2015 Belews Creek Steam Station

Similar to Allen Steam Station, Belews Creek used CAPP from February 1, 2008 to February 11, 2012.

However, fuel changes began in February 2012 and primarily involved the use of Northern Appalachian (NAPP) coal as opposed to ILB coal. As shown in Table 4, changes in the coal affected the performance

of the treatment system. For example, the station used a blend of CAPP and NAPP coal from May 18,

2012 to May 25, 2012. Initially, the blend was 80% CAPP and 20% NAPP, which caused minimal

increases in the selenium concentration in the bioreactor effluent. As the percentage of NAPP coal

increased, the selenium concentration in the bioreactor effluent also increased as observed on May 28

to June 1, 2012. There was a similar occurrence during the period from November 5, 2012 to December

28, 2012. Initially the station used only 10% NAPP and increased the percentage to 35%. Again, as the

percent of NAPP coal increased, there were elevated concentrations of selenium observed in the

bioreactor effluent. The data from these two occurrences, also, indicate an approximate seven

‐ day lag

time between when the coal is used and the effects are observed in the effluent of the treatment

system. Again, it is difficult to verify that the biological system would adapt given adequate time, due to

the limited duration of the use of different fuels in the current data set. And in any event, as with Allen

Station, even if the biological system can adapt to a coal switch given enough time, the facility would be

out of compliance during the period of adaptation.

Duke Energy believes the variability in the selenium concentrations at the bioreactor effluent are going

to continue as shown by recently collected data in 2015.

Date Se, tot (ug/L)

1/14/2015 9.67 1/29/2015 32.2 2/11/2015 13.1 2/25/2015 37.9 3/11/2015 11.6 3/24/2015 <5 4/13/2015 11.3Unit 1 Unit 2 Unit 3 Unit 4 Unit 5 4/29/2011 ILB ‐ Gibson County 100% 0 0 155 193 161 4/30/2011 ILB ‐ Gibson County 100% 0 0 0 202 0

5/1/2011 ILB ‐ Gibson County 100% 64 0 151 189 136 5/2/2011 ILB ‐ Gibson County 100% 138 114 244 256 247 5/3/2011 ILB ‐ Gibson County 100% 141 135 244 255 247 5/4/2011 ILB ‐ Gibson County 100% 94 31 212 227 217 5/5/2011 ILB ‐ Gibson County 100% 0 0 209 218 204 5/6/2011 ILB ‐ Gibson County 100% 0 0 206 220 201 5/7/2011 ILB ‐ Gibson County 100% 6 2 223 220 219 5/8/2011 ILB ‐ Gibson County 100% 118 105 223 227 222 5/9/2011 ILB ‐ Gibson County 100% <5 130 126 250 254 249 5/10/2011 ILB ‐ Gibson County 100% 146 140 257 262 255 5/11/2011 ILB ‐ Gibson County 100% 144 138 243 253 244 5/12/2011 ILB ‐ Gibson County 100% 140 131 250 261 250 5/13/2011 ILB ‐ Gibson County 100% 133 125 243 243 238 5/14/2011 ILB ‐ Gibson County 100% 93 76 209 0 194 5/15/2011 ILB ‐ Gibson County 100% 90 0 176 0 175 5/16/2011 ILB ‐ Gibson County 100% 49 0 191 0 203 5/17/2011 ILB ‐ Gibson County 100% 0 0 181 0 175 5/18/2011 ILB ‐ Gibson County 100% 0 0 192 0 156 5/19/2011 ILB ‐ Gibson County 100% 109 0 179 187 0 5/20/2011 ILB ‐ Gibson County 100% 94 61 183 205 0 5/21/2011 ILB ‐ Gibson County 100% 100 92 190 204 0 5/22/2011 ILB ‐ Gibson County 100% 116 112 212 222 15 5/23/2011 ILB ‐ Gibson County 100% 11.7 126 125 214 232 224 5/24/2011 ILB ‐ Gibson County 100% 133 128 233 247 235 5/25/2011 ILB ‐ Gibson County 100% 135 134 201 250 237

11/28/2011 ILB ‐ Somerville 50% 0 0 6 0 0 11/29/2011 ILB ‐ Somerville 50% 0 0 262 229 156 11/30/2011 ILB ‐ Somerville 50% 0 0 271 273 129

12/1/2011 ILB ‐ Somerville 50% 0 0 261 265 0 12/2/2011 ILB ‐ Somerville 50% 0 0 278 286 0 12/3/2011 ILB ‐ Somerville 50% 0 0 295 295 0 12/4/2011 ILB ‐ Somerville 50% 0 0 275 289 0 12/5/2011 ILB ‐ Somerville 50% 1 2 264 282 60 12/6/2011 ILB ‐ Somerville 50% 145 142 278 276 283 12/7/2011 ILB ‐ Somerville 50% 176 161 279 187 295 12/8/2011 ILB ‐ Somerville 50% 173 166 295 0 295 12/9/2011 ILB ‐ Somerville 50% 141 108 272 0 271 12/10/2011 ILB ‐ Somerville 50% 118 122 218 0 223 12/11/2011 ILB ‐ Somerville 50% 113 7 223 0 219

Analysis of the effects of fuel on the performance of the FGD wastewater treatment system at Allen Steam Station Table 1

Date Non Standard Fuel Se, tot (ug/L) Loads (MW)Unit 1 Unit 2 Unit 3 Unit 4 Unit 5 Analysis of the effects of fuel on the performance of the FGD wastewater treatment system at Allen Steam Station Table 1

Date Non Standard Fuel Se, tot (ug/L) Loads (MW)

12/12/2011 ILB ‐ Somerville 50% 2 95 177 119 189 12/13/2011 ILB ‐ Somerville 50% 154 158 274 273 267 12/14/2011 ILB ‐ Somerville 50% 181 175 292 295 290 12/15/2011 ILB ‐ Somerville 50% 171 164 291 297 257 12/16/2011 ILB ‐ Somerville 50% 21.7 172 168 294 299 30 12/17/2011 ILB ‐ Somerville 50% 144 138 275 279 273 12/18/2011 ILB ‐ Somerville 50% 171 164 295 302 295 12/19/2011 ILB ‐ Somerville 50% 13.2 115 102 239 250 230 12/20/2011 ILB ‐ Somerville 50% 14.5 143 133 280 288 278 12/21/2011 ILB ‐ Somerville 50% 92 83 210 218 203 12/22/2011 ILB ‐ Somerville 50% 0 0 172 151 180 12/23/2011 ILB ‐ Somerville 50% 0 0 215 228 220 12/24/2011 ILB ‐ Somerville 50% 0 0 177 184 192 12/25/2011 ILB ‐ Somerville 50% 0 0 145 165 158 12/26/2011 ILB ‐ Somerville 50% 52 34 243 273 248 12/27/2011 ILB ‐ Somerville 50% 23.8 129 143 281 292 272 12/28/2011 ILB ‐ Somerville 50% 110 99 239 257 241 12/29/2011 ILB ‐ Somerville 50% 0 0 127 264 236 12/30/2011 ILB ‐ Somerville 50% 0 0 0 244 217 12/31/2011 ILB ‐ Somerville 50% 0 0 0 102 202

7/5/2012 ILB ‐ Shay #1 50% 90 90 142 194 178 7/6/2012 ILB ‐ Shay #1 50% 111 109 201 217 203 7/7/2012 ILB ‐ Shay #1 50% 115 110 199 204 202 7/8/2012 ILB ‐ Shay #1 50% 117 111 200 223 206 7/9/2012 ILB ‐ Shay #1 50% 115 109 212 229 218 7/10/2012 ILB ‐ Shay #1 50% 126 125 227 243 234 7/11/2012 ILB ‐ Shay #1 50% 146 143 254 272 264 7/12/2012 ILB ‐ Shay #1 50% 152 148 264 285 278 7/13/2012 ILB ‐ Shay #1 50% 141 136 248 265 255 7/14/2012 ILB ‐ Shay #1 50% 49 48 202 233 203 7/15/2012 ILB ‐ Shay #1 50% 0 0 0 114 0 7/16/2012 ILB ‐ Shay #1 50% 0 0 0 102 0 7/17/2012 ILB ‐ Shay #1 50% 0 0 0 100 0 7/18/2012 ILB ‐ Shay #1 50% 75 46 144 186 152 7/19/2012 ILB ‐ Shay #1 50% 124 120 205 210 215 7/20/2012 ILB ‐ Shay #1 50% 120 104 199 189 209 7/21/2012 ILB ‐ Shay #1 50% 116 115 186 182 203 7/22/2012 ILB ‐ Shay #1 50% 107 105 181 178 178 7/23/2012 ILB ‐ Shay #1 50% 59 63 100 131 87 7/24/2012 ILB ‐ Shay #1 50% 50 50 73 99 64 7/25/2012 ILB ‐ Shay #1 50% 65 64 100 120 98Unit 1 Unit 2 Unit 3 Unit 4 Unit 5 Analysis of the effects of fuel on the performance of the FGD wastewater treatment system at Allen Steam Station Table 1

Date Non Standard Fuel Se, tot (ug/L) Loads (MW)

7/26/2012 ILB ‐ Shay #1 50% 50 50 73 99 65 7/27/2012 ILB ‐ Shay #1 50% 100 98 150 163 150 7/28/2012 ILB ‐ Shay #1 50% 119 117 176 196 181 7/29/2012 ILB ‐ Shay #1 50% 103 102 163 178 160 7/30/2012 ILB ‐ Shay #1 50% 92 91 139 160 137 7/31/2012 ILB ‐ Shay #1 50% 70 70 108 127 112

8/1/2012 ILB ‐ Shay #1 50% 139 137 188 228 215 8/2/2012 ILB ‐ Shay #1 50% 137 133 236 255 255 8/3/2012 ILB ‐ Shay #1 50% 131 128 235 257 249 8/4/2012 ILB ‐ Shay #1 50% 139 136 244 263 255 8/5/2012 ILB ‐ Shay #1 50% 70 47 166 257 162 8/6/2012 ILB ‐ Shay #1 50% 0 0 0 107 0 8/7/2012 ILB ‐ Shay #1 50% 0 0 0 95 0 8/8/2012 ILB ‐ Shay #1 50% 11.3 103 95 152 212 159 8/9/2012 ILB ‐ Shay #1 50% 132 126 222 230 220 8/10/2012 ILB ‐ Shay #1 50% 127 122 216 228 221 8/11/2012 ILB ‐ Shay #1 50% 121 115 223 235 224 8/12/2012 ILB ‐ Shay #1 50% 118 114 220 237 226 8/13/2012 ILB ‐ Shay #1 50% 118 106 207 224 212 8/14/2012 ILB ‐ Shay #1 50% 101 97 186 195 188 8/15/2012 ILB ‐ Shay #1 50% 53 56 102 100 65 8/16/2012 ILB ‐ Shay #1 50% 48 50 93 84 63 8/17/2012 ILB ‐ Shay #1 50% 128 128 225 224 220 8/18/2012 ILB ‐ Shay #1 50% 123 120 260 272 265 8/19/2012 ILB ‐ Shay #1 50% 113 111 205 226 205 8/20/2012 ILB ‐ Shay #1 50% 49 48 87 82 61 8/21/2012 ILB ‐ Shay #1 50% 50 48 87 80 61 8/22/2012 ILB ‐ Shay #1 50% 110 100 183 189 178 8/23/2012 ILB ‐ Shay #1 50% 99 0 162 186 160 8/24/2012 ILB ‐ Shay #1 50% 111 0 183 198 179 8/25/2012 ILB ‐ Shay #1 50% 114 0 188 202 185 8/26/2012 ILB ‐ Shay #1 50% 116 0 190 208 185 8/27/2012 ILB ‐ Shay #1 50% 109 0 209 229 214 8/28/2012 ILB ‐ Shay #1 50% 103 0 186 197 189 8/29/2012 ILB ‐ Shay #1 50% 11.5 101 0 187 210 196 8/30/2012 ILB ‐ Shay #1 50% 123 0 20 227 215 8/31/2012 ILB ‐ Shay #1 50% 125 0 210 225 209

9/1/2012 ILB ‐ Shay #1 50% 127 0 218 233 212 9/2/2012 ILB ‐ Shay #1 50% 120 0 209 223 77 9/3/2012 ILB ‐ Shay #1 50% 120 0 192 219 0 9/4/2012 ILB ‐ Shay #1 50% 87 0 180 208 0 9/5/2012 ILB ‐ Shay #1 50% 11.9 0 0 0 184 0Unit 1 Unit 2 Unit 3 Unit 4 Unit 5 Analysis of the effects of fuel on the performance of the FGD wastewater treatment system at Allen Steam Station Table 1

Date Non Standard Fuel Se, tot (ug/L) Loads (MW)

9/6/2012 ILB ‐ Shay #1 50% 0 0 0 204 0 9/7/2012 ILB ‐ Shay #1 50% 12.9 0 0 0 140 0 9/8/2012 ILB ‐ Shay #1 50% 0 0 0 74 0 9/9/2012 CAPP ‐ Miller Creek 0 0 0 0 0 9/10/2012 CAPP ‐ Miller Creek 0 0 0 0 0 9/11/2012 CAPP ‐ Miller Creek 16.0 0 0 0 156 0

1/18/2013 CAPP ‐ Miller Creek 11.9 0 0 148 173 0 1/19/2013 CAPP ‐ Miller Creek 0 0 180 183 0 1/20/2013 CAPP ‐ Miller Creek 0 0 148 149 2 1/21/2013 ILB ‐ Shay #1 0 0 205 212 204 1/22/2013 ILB ‐ Shay #1 0 0 238 250 250 1/23/2013 ILB ‐ Shay #1 27.6 89 57 249 198 259 1/24/2013 ILB ‐ Shay #1 101 108 261 210 260 1/25/2013 ILB ‐ Shay #1 23.2 140 144 256 268 267 1/26/2013 ILB ‐ Shay #1 0 0 176 184 183 1/27/2013 ILB ‐ Shay #1 0 0 154 165 165 1/28/2013 ILB ‐ Shay #1 19.7 0 0 201 215 210 1/29/2013 ILB ‐ Shay #1 0 0 210 215 203 1/30/2013 ILB ‐ Shay #1 19.8 0 0 145 149 139 1/31/2013 ILB ‐ Shay #1 0 0 198 207 198

2/1/2013 ILB ‐ Shay #1 13.5 0 0 200 208 157 2/2/2013 ILB ‐ Shay #1 0 0 193 192 0 2/3/2013 ILB ‐ Shay #1 0 0 151 151 0 2/4/2013 ILB ‐ Shay #1 11.1 0 0 239 240 226 2/5/2013 ILB ‐ Shay #1 0 0 223 228 226 2/6/2013 ILB ‐ Shay #1 11.1 0 0 117 200 234 2/7/2013 ILB ‐ Shay #1 0 0 0 239 241 2/8/2013 ILB ‐ Shay #1 <5 0 0 0 208 205 2/9/2013 ILB ‐ Shay #1 0 0 0 168 174 2/10/2013 ILB ‐ Shay #1 0 0 0 176 163 2/11/2013 ILB ‐ Shay #1 5.84 0 0 0 219 219 2/12/2013 ILB ‐ Shay #1 0 0 144 212 207 2/13/2013 ILB ‐ Shay #1 5.31 0 0 195 216 209 2/14/2013 ILB ‐ Shay #1 0 0 210 219 213 2/15/2013 ILB ‐ Shay #1 5.65 0 0 206 217 206 2/16/2013 ILB ‐ Shay #1 0 0 1 220 203 2/17/2013 ILB ‐ Shay #1 0 0 0 200 193 2/18/2013 ILB ‐ Shay #1 <5 0 0 0 189 134Unit 1 Unit 2 Unit 3 Unit 4 Unit 5 1/18/2014 00000 1/19/2014 00000 1/20/2014 74 62 107 119 84 1/21/2014 85 92 173 199 170 1/22/2014 131 130 244 267 239 1/23/2014 144 140 265 280 264 1/24/2014 157 158 281 293 254 1/25/2014 143 128 272 286 268 1/26/2014 88 88 197 236 194 1/27/2014 17.7 79 75 151 177 147 1/28/2014 136 135 249 267 255 1/29/2014 148 133 268 293 267 1/30/2014 152 147 273 284 274 1/31/2014 76 74 141 151 154

2/3/2014 00000 2/4/2014 00000 2/5/2014 0 0 164 134 0 2/6/2014 127 89 247 269 227 2/7/2014 128 133 244 257 246 2/8/2014 118 118 239 256 246 2/9/2014 119 117 220 219 221 2/10/2014 125 144 225 251 243 2/11/2014 161 174 248 273 251 2/12/2014 166 175 272 284 273 2/13/2014 87 151 162 177 170 2/14/2014 0 0 78 183 169 2/15/2014 0 0 0 210 204 2/16/2014 0 0 0 218 198 2/17/2014 0 0 0 263 247 2/18/2014 0 0 0 116 110 2/19/2014 00000 2/20/2014 00000 2/21/2014 00000 2/22/2014 00000 2/23/2014 00000 2/24/2014 00100 2/25/2014 0 0 135 138 115 2/26/2014 38.5 60 0 206 229 211 2/27/2014 117 0 205 228 211 Loads (MW) Date Se, tot (ug/L) Table 2

Recent Performance of the FGD wastewater Treatment System at Allen Steam

StationUnit 1 Unit 2 Unit 3 Unit 4 Unit 5 Loads (MW) Date Se, tot (ug/L) Table 2

Recent Performance of the FGD wastewater Treatment System at Allen Steam

Station

2/28/2014 45 0 116 151 105

3/1/2014 00000 3/2/2014 00000 3/3/2014 0 0 137 120 0 3/4/2014 0 0 271 281 0 3/5/2014 0 0 260 270 0 3/6/2014 21.8 0 0 265 271 0 3/7/2014 0 0 245 263 0 3/8/2014 0 0 184 192 0 3/9/2014 0 0 167 171 0 3/10/2014 0 0 206 239 0 3/11/2014 0 0 194 228 0 3/12/2014 0 0 163 217 84 3/13/2014 0 0 38 243 221 3/14/2014 0 0 121 132 220 3/15/2014 0 0 0 0 144 3/16/2014 0 0 0 0 183 3/17/2014 0 0 233 191 260 3/18/2014 0 0 240 254 259 3/19/2014 0 0 222 257 143 3/20/2014 0 0 96 108 0 3/21/2014 00000 3/22/2014 0 29 0 0 0 3/23/2014 0 116 0 0 1 3/24/2014 0 113 177 201 204 3/25/2014 126 136 259 267 250 3/26/2014 17.3 148 160 280 274 271 3/27/2014 77 69 168 162 145 3/28/2014 00000

5/3/2014 00000 5/4/2014 00000 5/5/2014 0 0 136 0 182 5/6/2014 11.1 0 113 189 0 234 5/7/2014 84 122 211 0 203 5/8/2014 127 126 212 0 220 5/9/2014 119 114 193 0 206 5/10/2014 16 13 0 0 160 5/11/2014 0 0 0 0 214 5/12/2014 55 95 196 0 231Unit 1 Unit 2 Unit 3 Unit 4 Unit 5 Loads (MW) Date Se, tot (ug/L) Table 2

Recent Performance of the FGD wastewater Treatment System at Allen Steam

Station

5/13/2014 141 138 189 179 229 5/14/2014 142 131 0 278 247 5/15/2014 4 0 157 36 195 5/16/2014 0 0 109 0 0 5/17/2014 00000 5/18/2014 00000 5/19/2014 00000 5/20/2014 00000 5/21/2014 4.8 0 0 124 112 146 5/22/2014 0 0 212 225 210 5/23/2014 0 0 178 208 191 5/24/2014 0 0 0 0 22 5/25/2014 00000 5/26/2014 00000 5/27/2014 0 0 156 0 5 5/28/2014 68 116 221 0 229 5/29/2014 130 131 218 0 223 5/30/2014 115 123 223 0 185 5/31/2014 0 0 165 0 0

6/1/2014 00000 6/2/2014 0 0 166 0 0 6/3/2014 5.92 113 122 184 45 0 6/4/2014 106 105 189 195 0 6/5/2014 117 115 199 212 0 6/6/2014 114 99 197 207 0 6/7/2014 113 102 186 196 0 6/8/2014 107 98 169 174 0 6/9/2014 115 107 203 213 148 6/10/2014 126 121 220 225 221 6/11/2014 117 109 229 242 222 6/12/2014 128 128 207 211 221 6/13/2014 105 100 206 201 205 6/14/2014 0 0 190 192 0 6/15/2014 0 0 209 170 0 6/16/2014 5.8 94 103 219 269 191 6/17/2014 125 120 218 227 217 6/18/2014 144 135 235 242 228 6/19/2014 128 124 213 221 214 6/20/2014 128 116 228 234 219 6/21/2014 127 0 214 135 221Unit 1 Unit 2 Unit 3 Unit 4 Unit 5 Loads (MW) Date Se, tot (ug/L) Table 2

Recent Performance of the FGD wastewater Treatment System at Allen Steam

Station

6/22/2014 132 0 11 0 226 6/23/2014 144 102 24 0 237 6/24/2014 123 119 66 0 162 6/25/2014 129 125 183 0 172 6/26/2014 137 132 215 0 172 6/27/2014 143 139 221 0 0 6/28/2014 11800 6/29/2014 00000 6/30/2014 0 69 148 164 0

7/1/2014 14.3 101 122 200 189 0 7/2/2014 127 127 201 211 0 7/3/2014 75 105 149 149 0 7/4/2014 0 76 0 0 0 7/5/2014 0 73 0 0 0 7/6/2014 0 105 0 0 0 7/7/2014 61 121 152 187 72 7/8/2014 129 125 218 212 221 7/9/2014 109 108 200 204 191 7/10/2014 41 101 75 184 87 7/11/2014 0 94 0 170 0 7/12/2014 0 121 0 205 0 7/13/2014 0 111 75 194 0 7/14/2014 0 126 136 170 0 7/15/2014 9.14 0 108 159 216 144 7/16/2014 0 0 144 228 151 7/17/2014 0 0 63 159 165 7/18/2014 0 0 0 0 147 7/19/2014 0 0 0 0 126 7/20/2014 0 0 0 0 129 7/21/2014 0 0 84 0 129 7/22/2014 0 0 173 0 202 7/23/2014 0 0 201 145 199 7/24/2014 0 0 196 192 195 7/25/2014 0 0 177 177 176 7/26/2014 0 0 199 202 198 7/27/2014 0 0 186 190 184 7/28/2014 0 0 150 168 185 7/29/2014 3.25 0 0 0 0 201 7/30/2014 0 0 0 0 187 7/31/2014 0 0 0 0 121Unit 1 Unit 2 Unit 3 Unit 4 Unit 5 Loads (MW) Date Se, tot (ug/L) Table 2

Recent Performance of the FGD wastewater Treatment System at Allen Steam

Station

8/1/2014 00000 8/2/2014 00000 8/3/2014 00000 8/4/2014 0 0 0 0 158 8/5/2014 0 0 0 0 196 8/6/2014 0 0 0 0 191 8/7/2014 0 0 0 0 142 8/8/2014 0 0 0 0 103 8/9/2014 00000 8/10/2014 00000 8/11/2014 94 0000 8/12/2014 124 0000 8/13/2014 110 0 0 0 124 8/14/2014 1.94 97 0007 8/15/2014 115 0000 8/16/2014 103 0000 8/17/2014 93 0 0 135 0 8/18/2014 102 0 106 189 0 8/19/2014 109 0 192 201 0 8/20/2014 111 91 137 199 1 8/21/2014 109 113 135 211 0 8/22/2014 109 100 0 216 0 8/23/2014 92 0 0 183 0 8/24/2014 00000 8/25/2014 0 0 0 0 103 8/26/2014 0 0 0 0 111 8/27/2014 3.54 75 0000 8/28/2014 110 0000 8/29/2014 126 0000 8/30/2014 109 0000 8/31/2014 107 0000

9/1/2014 113 0 122 148 0 9/2/2014 124 101 214 221 0 9/3/2014 117 119 225 0 0 9/4/2014 105 108 227 0 0 9/5/2014 102 107 208 0 0 9/6/2014 116 108 198 0 0 9/7/2014 110 0000 9/8/2014 72 0000 9/9/2014 70 0000Unit 1 Unit 2 Unit 3 Unit 4 Unit 5 Loads (MW) Date Se, tot (ug/L) Table 2

Recent Performance of the FGD wastewater Treatment System at Allen Steam

Station

9/10/2014 114 0000 9/11/2014 128 0000 9/12/2014 117 0000 9/13/2014 00000

11/9/2014 0 0 0 176 169 11/10/2014 0 0 0 201 195 11/11/2014 0 0 0 180 173 11/12/2014 3.3 0 0 0 182 178 11/13/2014 65 63 116 186 175 11/14/2014 116 125 232 222 211 11/15/2014 134 133 236 242 227 11/16/2014 86 86 190 177 168 11/17/2014 93 90 198 192 187 11/18/2014 6.65 147 143 250 262 249 11/19/2014 161 159 277 298 293 11/20/2014 109 110 234 248 241 11/21/2014 97 95 212 202 204 11/22/2014 64 69 109 228 217 11/23/2014 0 0 0 70 149 11/24/2014 0 0 0 0 161 11/25/2014 0 0 0 0 201 11/26/2014 0 0 0 0 195 11/27/2014 00000

12/5/2014 00000 12/6/2014 00000 12/7/2014 2 1 32 0 102 12/8/2014 126 138 232 179 236 12/9/2014 113 110 219 224 217 12/10/2014 94 113 213 222 212 12/11/2014 0 129 215 237 221 12/12/2014 0 69 197 218 204 12/13/2014 0 0 191 195 179 12/14/2014 0 0 198 182 171 12/15/2014 18.7 0 0 151 190 177 12/16/2014 0 0 0 174 163 12/17/2014 0 0 0 168 161 12/18/2014 0 0 0 200 192 12/19/2014 0 0 0 200 187 12/20/2014 00000Unit 1 Unit 2 Unit 3 Unit 4 Unit 5 Loads (MW) Date Se, tot (ug/L) Table 2

Recent Performance of the FGD wastewater Treatment System at Allen Steam

Station

12/21/2014 00000

1/4/2015 00000 1/5/2015 00000 1/6/2015 0 1 18 28 13 1/7/2015 15.1 29 125 220 253 233 1/8/2015 160 160 126 279 260 1/9/2015 124 123 0 223 208 1/10/2015 110 108 0 236 212 1/11/2015 79 79 0 229 138 1/12/2015 0 0 0 70 0 1/13/2015 00000 1/25/2015 00000 1/26/2015 0 0 0 11 0 1/27/2015 0 0 28 182 156 1/28/2015 38.4 0 0 202 203 202 1/29/2015 0 0 176 174 170 1/30/2015 0 0 163 164 0 1/31/2015 0 0 186 195 0

2/1/2015 7 7 140 138 12 2/2/2015 78 78 152 152 167 2/3/2015 144 140 176 187 229 2/4/2015 67 79 220 225 163 2/5/2015 0 0 159 168 147 2/6/2015 0 0 124 183 133 2/7/2015 0 0 0 82 0 2/8/2015 00000 2/9/2015 00000 2/10/2015 00000 2/11/2015 00002 2/12/2015 48 33 186 200 202 2/13/2015 125 122 229 248 238 2/14/2015 98 99 199 212 200 2/15/2015 129 126 264 235 228 2/16/2015 20 155 153 86 271 213 2/17/2015 149 143 0 247 0 2/18/2015 149 143 0 285 3 2/19/2015 156 155 245 276 262 2/20/2015 159 156 268 286 275 2/21/2015 131 130 254 278 261Unit 1 Unit 2 Unit 3 Unit 4 Unit 5 Loads (MW) Date Se, tot (ug/L) Table 2

Recent Performance of the FGD wastewater Treatment System at Allen Steam

Station

2/22/2015 79 80 181 202 189 2/23/2015 50.6 119 118 212 220 44Unit1 Unit2 Unit3 Unit4 Unit511/24/2012 1.953.350 0 168 162 0 CAPP‐MillerCreek11/25/2012 3.316.160 0 223 237 0 CAPP‐MillerCreek11/26/2012 3.356.3017.20 0 208 218 0 CAPP‐MillerCreek11/27/2012 3.256.000 0 212 250 0 CAPP‐MillerCreek11/28/2012 3.176.020 0 217 257 0 CAPP‐MillerCreek11/29/2012 2.875.260 0 236 277 0 CAPP‐MillerCreek11/30/2012 3.085.670 0 202 223 0 CAPP‐MillerCreek12/1/2012 1.181.920 0 75 168 0 CAPP‐MillerCreek12/2/2012 3.125.820 0 0 0 0 CAPP‐MillerCreek12/3/2012 3.125.820 0 0 0 0 CAPP‐MillerCreek12/4/20120 0 0 0 0 CAPP‐MillerCreek12/5/20120 0 0 0 122 CAPP‐MillerCreek12/6/2012 1.031.680 0 0 0 159 CAPP‐MillerCreek12/7/2012 1.031.680 0 0 0 71 CAPP‐MillerCreek12/8/20120 0 0 0 0 CAPP‐MillerCreek12/9/20120 0 0 0 0 CAPP‐MillerCreek12/10/2012 1.181.920 0 0 0 0 CAPP‐MillerCreek12/11/2012 1.452.490 0 114 147 0 CAPP‐MillerCreek12/12/2012 0.961.640 0 200 211 175 CAPP‐MillerCreek12/13/2012 1.021.760 0 191 205 198 CAPP‐MillerCreek12/14/2012 1.582.670 0 96 106 217 CAPP‐MillerCreek12/15/2012 1.522.560 0 0 0 191 CAPP‐MillerCreek12/16/201224.70 0 0 0 0 CAPP‐MillerCreekSO2(lbm/Mbtu)Se,tot(ug/L)Loads(MW)FuelDateSulfurContent(%As_Received)EffectsofchangesinthecharacteristicsofthecoalontheperformanceoftheFGDWastewaterTreatmentSystematAllenSteamStationTable3Date Percentage of Coal

Blend Coal Basin ‐ Coal

Mine Percentage of

Coal Blend Coal Basin ‐ Coal

Mine Se, tot (ug/L)

5/18/2012 80 CAPP ‐ Camp Creek 20 NAPP ‐ Enlow Fork 5/19/2012 80 CAPP ‐ Camp Creek 20 NAPP ‐ Enlow Fork 5/20/2012 80 CAPP ‐ Camp Creek 20 NAPP ‐ Enlow Fork 5/21/2012 80 CAPP ‐ Camp Creek 20 NAPP ‐ Enlow Fork <10 5/22/2012 70 CAPP ‐ Camp Creek 30 NAPP ‐ Enlow Fork 6.97 5/23/2012 70 CAPP ‐ Camp Creek 30 NAPP ‐ Enlow Fork 6.65 5/24/2012 70 CAPP ‐ Camp Creek 30 NAPP ‐ Enlow Fork 5/25/2012 70 CAPP ‐ Camp Creek 30 NAPP ‐ Enlow Fork 5/26/2012 100 CAPP ‐ Camp Creek 5/27/2012 100 CAPP ‐ Camp Creek 5/28/2012 100 CAPP ‐ Camp Creek 13.2 5/29/2012 100 CAPP ‐ Camp Creek 13.7 5/30/2012 100 CAPP ‐ Camp Creek 15.9 5/31/2012 100 CAPP ‐ Camp Creek 15.1

6/1/2012 100 CAPP ‐ Camp Creek 12.9

11/5/2012 90 CAPP ‐ Camp Creek 10 NAPP ‐ Enlow Fork 7.78 11/6/2012 90 CAPP ‐ Camp Creek 10 NAPP ‐ Enlow Fork 11/7/2012 90 CAPP ‐ Camp Creek 10 NAPP ‐ Enlow Fork 11/8/2012 85 CAPP ‐ Camp Creek 15 NAPP ‐ Enlow Fork 11/9/2012 85 CAPP ‐ Camp Creek 15 NAPP ‐ Enlow Fork 5.3 11/10/2012 85 CAPP ‐ Camp Creek 15 NAPP ‐ Enlow Fork 11/11/2012 85 CAPP ‐ Camp Creek 15 NAPP ‐ Enlow Fork 11/12/2012 80 CAPP ‐ Camp Creek 20 NAPP ‐ Enlow Fork <5 11/13/2012 80 CAPP ‐ Camp Creek 20 NAPP ‐ Enlow Fork 11/14/2012 80 CAPP ‐ Camp Creek 20 NAPP ‐ Enlow Fork <5 11/15/2012 75 CAPP ‐ Camp Creek 25 NAPP ‐ Enlow Fork 11/16/2012 75 CAPP ‐ Camp Creek 25 NAPP ‐ Enlow Fork <5 11/17/2012 75 CAPP ‐ Camp Creek 25 NAPP ‐ Enlow Fork 11/18/2012 75 CAPP ‐ Camp Creek 25 NAPP ‐ Enlow Fork 11/19/2012 70 CAPP ‐ Camp Creek 30 NAPP ‐ Enlow Fork 7.78 11/20/2012 70 CAPP ‐ Camp Creek 30 NAPP ‐ Enlow Fork 11/21/2012 70 CAPP ‐ Camp Creek 30 NAPP ‐ Enlow Fork 5.32 11/22/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 11/23/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 9.27 11/24/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 11/25/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 11/26/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 11/27/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 11/28/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 6.15 11/29/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork Table 4 Analysis of the Effects of Fuel on the Performance of the FGD Wastewater Treatment System at Belews Creek

Steam StationDate Percentage of Coal

Blend Coal Basin ‐ Coal

Mine Percentage of

Coal Blend Coal Basin ‐ Coal

Mine Se, tot (ug/L) Table 4 Analysis of the Effects of Fuel on the Performance of the FGD Wastewater Treatment System at Belews Creek

Steam Station

11/30/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 6.67

12/1/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 12/2/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 12/3/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 10.1 12/4/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 12/5/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 9.46 12/6/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 12/7/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 7.83 12/8/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 12/9/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 12/10/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 7.78 12/11/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 12/12/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 12/13/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 11.8 12/14/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 8.24 12/15/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 12/16/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 12/17/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork <5 12/18/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 12/19/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 6.05 12/20/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 12/21/2012 65 CAPP ‐ Camp Creek 35 NAPP ‐ Enlow Fork 10.3 12/22/2012 100 CAPP ‐ Camp Creek 12/23/2012 100 CAPP ‐ Camp Creek 6.07 12/24/2012 100 CAPP ‐ Camp Creek 12/25/2012 100 CAPP ‐ Camp Creek 12/26/2012 100 CAPP ‐ Camp Creek 9.09 12/27/2012 100 CAPP ‐ Camp Creek 12/28/2012 100 CAPP ‐ Camp Creek 13.7