SV 001 EU 001 Power Boiler 1 (Combusting Western Coal) 517 [101] 4,528,920 [102] MMBtu NOx 0.71 [103] 364.94 [112] 1,598.44 [113] 0 [114] 364.94 [116] 1,598.44 [121]

SV 001 EU 001 517 [101] 4,528,920 [102] MMBtu SO2 [104] 1,292.50 [112] 3,396.69 [113] 0 [114] 1,292.50 [116] 3,396.69 [121]

SV 001 EU 001 Power Boiler 1 (Combusting Distillate Fuel Oil) 517 [101] 4,528,920 [102] MMBtu NOx 0.15 [105] 76.03 [112] 333.01 [113] 0 [114] 76.03 [116] 333.01 [121]

SV 001 EU 001 517 [101] 4,528,920 [102] MMBtu SO2 0.21 [106] 109.63 [112] 480.20 [113] 0 [114] 109.63 [116] 480.20 [121]

SV 001 EU 001 Power Boiler 1 (Combusting Natural Gas) 517 [101] 4,528,920 [102] MMBtu NOx 0.9 [107] 465.30 [112] 2,038.01 [113] 0 [114] 465.30 [116] 2,038.01 [121]

SV 001 EU 001 517 [101] 4,528,920 [102] MMBtu SO2 0.0006 [108] 0.30 [112] 1.29 [113] 0 [114] 0.30 [116] 1.29 [121]

SV 002 EU 002 Power Boiler 2 (Combusting Western Coal) 765 [101] 6,701,400 [102] MMBtu NOx 0.71 [103] 540.00 [112] 2,365.20 [113] 0 [114] 540.00 [116] 2,365.20 [121]

SV 002 EU 002 765 [101] 6,701,400 [102] MMBtu SO2 [104] 1,912.50 [112] 5,026.05 [113] 0 [114] 1,912.50 [116] 5,026.05 [121]

SV 002 EU 002 Power Boiler 2 (Combusting Natural Gas) 765 [101] 6,701,400 [102] MMBtu NOx 0.9 [107] 688.50 [112] 3,015.63 [113] 0 [114] 688.50 [116] 3,015.63 [121]

SV 002 EU 002 765 [101] 6,701,400 [102] MMBtu SO2 0.0006 [108] 0.44 [112] 1.91 [113] 0 [114] 0.44 [116] 1.91 [121]

SV 003 EU 003 Process Boiler 1 (Combusting Distillate Fuel Oil) 79 [101] 692,040 [102] MMBtu NOx 0.15 [105] 11.62 [112] 50.89 [113] 0 [114] 11.62 [116] 50.89 [121]

SV 003 EU 003 79 [101] 692,040 [102] MMBtu SO2 0.21 [106] 16.75 [112] 73.38 [113] 0 [114] 16.75 [116] 73.38 [121]

SV 003 EU 003 Process Boiler 1 (Combusting Natural Gas) 79 [101] 692,040 [102] MMBtu NOx 0.095 [109] 7.52 [112] 32.95 [113] 0 [114] 7.52 [116] 32.95 [121]

SV 003 EU 003 79 [101] 692,040 [102] MMBtu SO2 0.0006 [108] 0.05 [112] 0.20 [113] 0 [114] 0.05 [116] 0.20 [121]

SV 003 EU 004 Process Boiler 2 (Combusting Distillate Fuel Oil) 79 [101] 692,040 [102] MMBtu NOx 0.15 [105] 11.62 [112] 50.89 [113] 0 [114] 11.62 [116] 50.89 [121]

SV 003 EU 004 79 [101] 692,040 [102] MMBtu SO2 0.21 [106] 16.75 [112] 73.38 [113] 0 [114] 16.75 [116] 73.38 [121]

SV 003 EU 004 Process Boiler 2 (Combusting Natural Gas) 79 [101] 692,040 [102] MMBtu NOx 0.095 [109] 7.52 [112] 32.95 [113] 0 [114] 7.52 [116] 32.95 [121]

SV 003 EU 004 79 [101] 692,040 [102] MMBtu SO2 0.0006 [108] 0.05 [112] 0.20 [113] 0 [114] 0.05 [116] 0.20 [121]

SVs 101-103 EU 100 Furnace 11 Hood Exhaust 160 [101] 1,401,600 [102] MMBtu NOx 0.3201 [110] 51.22 [112] 224.33 [113] 0 [114] 51.22 [117] 224.33 [122]

SVs 101-103 EU 100 160 [101] 1,401,600 [102] MMBtu SO2 1.1077 [110] 177.22 [112] 776.24 [113] 80 [115] 35.44 [118] 155.25 [122]

SVs 104-105 EU 104 Furnace 11 Waste Gas 160 [101] 1,401,600 [102] MMBtu NOx 0.7799 [110] 124.78 [112] 546.55 [113] 0 [114] 124.78 [117] 546.55 [122]

SVs 104-105 EU 104 160 [101] 1,401,600 [102] MMBtu SO2 0.3692 [110] 59.07 [112] 258.75 [113] 80 [115] 11.81 [118] 51.75 [122]

SVs 111-113 EU 110 Furnace 12 Hood Exhaust 160 [101] 1,401,600 [102] MMBtu NOx 0.3201 [110] 51.22 [112] 224.33 [113] 0 [114] 51.22 [117] 224.33 [122]

SVs 111-113 EU 110 160 [101] 1,401,600 [102] MMBtu SO2 1.1077 [110] 177.22 [112] 776.24 [113] 80 [115] 35.44 [118] 155.25 [122]

SVs 114-115 EU 114 Furnace 12 Waste Gas 160 [101] 1,401,600 [102] MMBtu NOx 0.7799 [110] 124.78 [112] 546.55 [113] 0 [114] 124.78 [117] 546.55 [122]

SVs 114-115 EU 114 160 [101] 1,401,600 [102] MMBtu SO2 0.3692 [110] 59.07 [112] 258.75 [113] 80 [115] 11.81 [118] 51.75 [122]

SVs 266-268 EU 634 Furnace 5 H.E./Waste Gas 100 [101] 876,000 [102] MMBtu NOx 0.4565 [110] 45.65 [112] 199.97 [113] 0 [114] 45.65 [119] 199.97 [122]

SVs 266-268 EU 634 100 [101] 876,000 [102] MMBtu SO2 0.6373 [110] 63.73 [112] 279.12 [113] 80 [115] 12.75 [120] 55.82 [122]

SVs 261-263 EU 262 Furnace 6 H.E./Waste Gas 100 [101] 876,000 [102] MMBtu NOx 0.4565 [110] 45.65 [112] 199.97 [113] 0 [114] 45.65 [119] 199.97 [122]

SVs 261-263 EU 262 100 [101] 876,000 [102] MMBtu SO2 0.6490 [110] 64.90 [112] 284.25 [113] 80 [115] 12.98 [120] 56.85 [122]

Total NOx: 1,620.3 [123] 7,097.1 [125] 1,620.3 [127] 7,097.1 [129]

Total SO2: 3,839.7 [124] 11,202.8 [126] 3,358.7 [128] 9,096.2 [130]

Notes:

[101] Maximum hourly throughput = Design capacity of emission unit: For Furnaces 11 and 12, 10 MM Btu/hr is added to account for producing flux pellets at a heat input greater than the furnaces' design capacities.

Power Boiler 1 517 MM Btu/hr

Power Boiler 2 765 MM Btu/hr

Process Boiler 1 79 MM Btu/hr

Process Boiler 2 79 MM Btu/hr

Furnace 11 160 MM Btu/hr

Furnace 12 160 MM Btu/hr

Furnace 5 100 MM Btu/hr

Furnace 6 100 MM Btu/hr

[102] Maximum annual throughput = Maximum hourly throughput x 8,760 hours/yr.

[103] AP-42, September 1998, Table 1.1-3 for 'PC-fired, dry bottom, wall-fired, bituminous, NSPS', converted from lbs/ton to lbs/MM Btu using the heat content in [111].

[104] Permit limit specified in permit 0750003-002, issued 9/29/2004:

2.5 lbs/MM Btu for 1-hour average

1.5 lbs/MM Btu for annual average

[105] AP-42, September 1998, Table 1.3-1 for 'Commercial/institutional, Distillate oil fired', converted from lbs/ton to lbs/MM Btu using the heat content in [111].

[106] Assumes all S in fuel is converted to SO2: 0.002 lb S/lb fuel x 7.21 lb fuel/gal / 0.136 MM Btu/gal x 64 lb SO2/32 lb S (fuel data from Northshore Mining)

[107] Based on results of stack test performed 5/27/94 on SV 002 (0.7 lb/MM Btu) while burning natural gas (worst case fuel for NOx), rounded to 0.9 lb/MM Btu.

[108] AP-42, March 1998, Table 1.4-2.

[109] AP-42, March 1998, Table 1.4-1 for 'Small Boilers (< 100 MM Btu/hr), Uncontrolled'.

[110] Uncontrolled emission factor (lbs/MM Btu) is back-calculated as Maximum Controlled Emissions (lbs/hr) / ((100-Control Eff.)/100) / Maximum Hourly Throughput (MM Btu/hr) 

[111] Maximum hourly throughput = Design Heat input of emission unit (MM Btu/hr), 

Western Coal 17.0 MM Btu/ton (from Northshore Mining Company)

Distillate fuel oil 136 MM Btu/1000 gals (from Northshore Mining Company)

Natural gas 1,050 MM Btu/MM cf (from AP-42, September 1995, Appendix A)

[112] Maximum Uncontrolled Emissions (lbs/hr) = Maximum Hourly Throughput (units/hr) x Uncontrolled Emission Factor (lbs/unit).

(%) (lbs/hr) (tons/yr)

Stack ID Emission Unit Throughput Pollutant Emission Factor

Northshore Mining Company

Table 1: Facility-wide Potential to Emit Calculations for NOx and SO2

Maximum Uncontrolled Emissions Control Efficiency Maximum Controlled Emissions

ID Description Maximum Units

(Units/hr) (Units/yr) (lbs/Unit) (lbs/hr) (tons/yr)
Northshore Mining Company

Table 1: Facility-wide Potential to Emit Calculations for NOx and SO2

[113] Maximum Uncontrolled Emissions (tons/yr) = Maximum Annual Throughput (units/yr) x Uncontrolled Emission Factor (lbs/unit) / 2,000 (lbs/ton).

[114] Either no Air Pollution Control Devices (APCDs) are used in this process or the APCD is ineffective for this pollutant. 

[115] Control Efficiency for a wet wall Electrostatic Precipitator (WWESP).

[116] Maximum Controlled Emissions (lbs/hr) = Maximum Uncontrolled Emissions (lbs/hr) x ((100-Control Eff.)/100).

[117] Based on results of stack test performed 1/8/1992 on Furnace 12. Emission factor = 1.1 lb/MM Btu x 160 MM Btu/hr = 176 lb/hr which is split between EU 100 and EU 104 (and EU 110 and EU 114) in the ratio 0.291:0.709.

[118] Based on a S mass balance from fuel oil, concentrate, bentonite and fluxstone performed by Mike Osmundson, Northshore Mining, 8/7/1998. SO2 emissions (5.96 g/s) are distributed between the hood exhaust stacks and the waste gas stacks in the ratio 75:25. 

[119] Based on the result of a stack test performed 10/10/1995 on one of the three Furnace 6 stacks (12.2333 lbs/hr from SV 263) x 3 stacks x safety factor of 1.15. 

[121] Maximum Controlled Emissions (tons/yr) = Maximum Uncontrolled Emissions (tons/yr) x ((100-Control Eff.)/100).

[122] Maximum Controlled Emissions (tons/yr) = Maximum Controlled Emissions (lbs/hr) x 8,760 hours/yr / 2,000 lbs/ton.

[123] Facility-wide Maximum Uncontrolled NOx emissions (lbs/hr) only considering worst-case fuel scenarios

[124] Facility-wide Maximum Uncontrolled SO2 emissions (lbs/hr) only considering worst-case fuel scenarios

[125] Facility-wide Maximum Uncontrolled NOx emissions (tons/yr) only considering worst-case fuel scenarios

[126] Facility-wide Maximum Uncontrolled SO2 emissions (tons/yr) only considering worst-case fuel scenarios

[127] Facility-wide Maximum Controlled NOx emissions (lbs/hr) only considering worst-case fuel scenarios

[128] Facility-wide Maximum Controlled SO2 emissions (lbs/hr) only considering worst-case fuel scenarios

[129] Facility-wide Maximum Controlled NOx emissions (tons/yr) only considering worst-case fuel scenarios

[130] Facility-wide Maximum Controlled SO2 emissions (tons/yr) only considering worst-case fuel scenarios

[120] Based on the result of a stack test performed 10/10/1995 on one of the three Furnace 6 (firing natural gas) stacks (1.08 lbs/hr from SV 263) x 3 stacks, adjusted to account for SO2 emissions from firing fuel oil. The latter assumes 0.4 % S in fuel oil and a density of 6.975 lbs/gallon.