5 Colo. Code Regs. § 1001-27-A-IV

Current through Register Vol. 47, No. 24, December 25, 2024

Section 5 CCR 1001-27-A-IV - Regional Haze Determinations

IV.A. BART Determinations

IV.A.1. The provisions of this Section IV.A. of Regulation Number 23 will be incorporated into Colorado's Regional Haze State Implementation Plan.

IV.A.2. The sources listed must not emit or cause to be emitted nitrogen oxides (NOx), sulfur dioxide (SO2), or particulate in excess of the following limits

BART Determinations for Colorado Sources
Unit	NOx Emission Limit	SO2 Emission Limit	Particulate Emission Limit
CENC Unit 4	0.37 lb/MMBtu (30-day rolling average) or 0.26 lb/MMBtu Combined Average for Units 4 and 5 (30-day rolling average)	1.0 lb/MMBtu (30-day rolling average)	0.07 lb/MMBtu
CENC Unit 5	0.19 lb/MMBtu (30-day rolling average) or 0.26 lb/MMBtu Combined Average for Units 4 and 5 (30-day rolling average)	1.0lb/MMBtu (30-day rolling average)	0.07 lb/MMBtu
Craig Unit 1	*	0.11 lb/MMBtu (30-day rolling average)	0.03 lb/MMBtu
Craig Unit 2	0.08 lb/MMBtu (30-day rolling average)	0.11 lb/MMBtu (30-day rolling average)	0.03 lb/MMBtu

*Refer to Section IV.D. for requirements

BART Determinations for Colorado Sources
Unit	NOx Emission Limit	SO2 Emission Limit	Particulate Emission Limit
Comanche Unit 1	0.20 lb/MMBtu (30-day rolling average) 0.15 lb/MMBtu (combined annual average for units 1 & 2)	0.12 lb/MMBtu (individual unit 30-day rolling average) 0.10 lb/MMBtu (combined annual average for units 1 & 2)	0.03 lb/MMBtu
Comanche Unit 2	0.20 lb/MMBtu (30-day rolling average) 0.15 lb/MMBtu (combined annual average for units 1 & 2)	0.12 lb/MMBtu (individual unit 30-day rolling average) 0.10 lb/MMBtu (combined annual average for units 1 & 2)	0.03 lb/MMBtu
Hayden Unit 1	0.08lb/MMBtu (30-day rolling average)	0.13 lb/MMBtu (30-day rolling average)	0.03 lb/MMBtu
Hayden Unit 2	0.07 lb/MMBtu (30-day rolling average)	0.13 lb/MMBtu (30-day rolling average)	0.03 lb/MMBtu
Martin Drake Unit 5	0.31 lb/MMBtu (30-day rolling average)	0.26 lb/MMBtu (30-day rolling average)	0.03 lb/MMBtu
Martin Drake Unit 6	0.31lb/MMBtu (30-day rolling average)	0.13lb/MMBtu (30-day rolling average)	0.03 lb/MMBtu
Martin Drake Unit 7	0.29 lb/MMBtu (30-day rolling average)	0.13lb/MMBtu (30-day rolling average)	0.03 lb/MMBtu
CEMEX-Lyons Kiln	255.3 lbs/hr (30-day rolling average) 901.0 tons/year (12-month rolling average)	25.3 lbs/hr (12-month rolling average) 95.0 tons/yr (12-month rolling average)	0.275 lb/ton of dry feed 20% opacity
CEMEX- Lyons Dryer	13.9 tons/yr	36.7 tons/yr	22.8 tons/yr 10% opacity

IV.A.3. Each source listed in the tables must comply with the limits and averaging times as expeditiously as practicable, but in no event later than five years after EPA approval of Colorado's state implementation plan for regional haze, which was January 30, 2013, with the exception of Craig Unit 1, or relevant component thereof. Each source listed in the tables must maintain control equipment or operational practices required to comply with the limits and averaging times, and establish procedures to ensure that such equipment or operational practices are properly operated and maintained.

IV.B. Reasonable Progress Determinations

IV.B.1. The provisions of this Section IV.B of Regulation Number 23 will be incorporated into Colorado's Regional Haze State Implementation Plan.

IV.B.2. The sources listed must not emit or cause to be emitted nitrogen oxides (NOx), sulfur dioxide (SO2), or particulate in excess of the following limits

RP Determinations for Colorado Sources
Emission Unit	NOx Emission Limit	SO2Emission Limit	Particulate Emission Limit
Rawhide Unit 101	0.145 lb/MMBtu (30-day rolling average)	0.11 lb/MMBtu (30-day rolling average)	0.03 lb/MMBtu
CENC Unit 3	246 tons per year (12-month rolling total)	1.2 lb/MMBtu	0.07 lb/MMBtu
Nixon	0.21 lb/MMBtu (30-day rolling average)	0.11 lb/MMBtu (30-day rolling average)	0.03 lb/MMBtu
Clark Units 1 & 2 Shutdown 12/31/2013	Shutdown 12/31/2013	Shutdown 12/31/2013	Shutdown 12/31/2013
Holcim- Florence Kiln	2.73 lbs/ton clinker (30-day rolling average) 2,086.8 tons/year	1.30 lbs/ton clinker (30-day rolling average) 721.4 tons/year	246.3 tons/year
Nucla	0.5 lb/MMBtu (30-day rolling average)*	0.4 lb/MMBtu (30-day rolling average)	0.03 lb/MMBtu

*Refer to Section IV.E. for requirements

RP Determinations for Colorado Sources
Emission Unit	NOx Emission Limit	SO2 Emission Limit	Particulate Emission Limit
Craig Unit 3	0.28 lb/MMBtu (30-day rolling average)	0.15 lb/MMBtu (30-day rolling average)	0.013 lb/MMBtu filterable PM 0.012 lb/MMBtu filterable PM10
Cameo Shutdown 12/31/2011	Shutdown 12/31/2011	Shutdown 12/31/2011	Shutdown 12/31/2011

IV.B.3. Each source listed in the table must comply with the limits and averaging times as expeditiously as practicable, but in no event later than December 31, 2017, except for Nucla. Each source listed in the table must maintain control equipment or operational practices required to comply with the limits and averaging times, and establish procedures to ensure that such equipment or operational practices are properly operated and maintained.

IV.C. Public Service Company of Colorado (PSCo) BART Alternative Program

IV.C.1. The provisions of this Section IV.C. of Regulation Number 23 (with the exception of the SO2 cap of Section IV.C.4.) will be incorporated into Colorado's Regional Haze State Implementation Plan.

IV.C.2. The sources listed must not emit or cause to be emitted nitrogen oxides (NOx), sulfur dioxide (SO2), or particulate in excess of the following limits, after the following compliance dates

BART Alternative Program Determinations for PSCo Sources
Emission Unit	NOx Emission Limit	SO2 Emission Limit	Particulate Emission Limit
Cherokee * Unit 1 Shutdown No later than 7/1/2012	0 Shutdown No later than 7/1/2012	0 Shutdown No later than 7/1/2012	0 Shutdown No later than 7/1/2012
Cherokee Unit 2 Shutdown 12/31/2011	0 Shutdown 12/31/2011	0 Shutdown 12/31/2011	0 Shutdown 12/31/2011
Cherokee Unit 3 Shutdown No later than 12/31/2016	0 Shutdown No later than 12/31/2016	0 Shutdown No later than 12/31/2016	0 Shutdown No later than 12/31/2016
Cherokee Unit 4	0.12 lb/MMBTU (30-day rolling average) by 12/31/2017 Natural Gas Operation 12/31/2017	7.81 tpy (rolling 12-month average) Natural Gas Operation 12/31/2017	0.03 lbs/MMBtu Natural Gas Operation 12/31/2017
Valmont Unit 5 Shutdown 12/31/2017 (closed April 2017)	0 Shutdown 12/31/2017	0 Shutdown 12/31/2017	0 Shutdown 12/31/2017
Pawnee	0.07 lb/MMBTU (30-day rolling average) by 12/31/2014	0.12 lbs/MMBtu (30-day rolling average) by 12/31/2014	0.03 lbs/MMBtu
Arapahoe** Unit 3 Shutdown 12/31/2013	0 Shutdown 12/31/2013	0 Shutdown 12/31/2013	0 Shutdown 12/31/2013
Arapahoe Unit 4	600 tpy (rolling 12-month average) Natural Gas Operation 12/31/2014	1.28 tpy (rolling 12-month average) Natural Gas Operation 12/31/2014	0.03 lbs/MMBtu Natural Gas Operation 12/31/2014

* 500 tpy NOx will be reserved from Cherokee Station for netting or offsets

** 300 tpy NOx will be reserved from Arapahoe Station for netting or offsets for additional natural gas generation

IV.C.3. Each source listed in the table must either shut down or comply with the limits and averaging times no later than the compliance date set forth in the table. Each source listed in the table must maintain any applicable control equipment required to comply with the limits and averaging times, and establish procedures to ensure that such equipment is properly operated and maintained.

IV.C.4. In addition to the listed emission limits and compliance dates, between January 1, 2013, and December 31, 2015, Cherokee Units 3 and 4 and Valmont, considered as a whole, must not emit in excess of 4,200 tons of SO2 per year as determined on a calendar year annual basis. Between January 1, 2016, and December 31, 2017, Cherokee Unit 4 and Valmont considered as a whole, must not emit in excess of 3,450 tons of SO2 per year as determined on a calendar year annual basis.

IV.D. Craig Unit 1 Additional Compliance Requirements

IV.D.1. Craig Unit 1 will close on or before December 31, 2025.

IV.D.2. Craig Unit 1 will meet a NOx emission limit of 0.28 lb/MMBtu 30-day rolling average going forward from January 1, 2017 (first compliance date January 31, 2017), until closure.

IV.D.3. Craig Unit 1 will meet an annual NOx limit of 4,065 tons per year by December 31, 2019, on a calendar year basis beginning in 2020.

IV.E. Nucla Compliance Requirements

IV.E.1. Nucla Station will close on or before December 31, 2022. Nucla Station closed in September 2019.

IV.F. Regional Haze Second Implementation Period, Reasonable Progress Determinations

IV.F.1. The following sources will close no later than the associated date. The sources must comply with the applicable emission limits in Section IV. and monitoring, recordkeeping, and reporting requirements in Section V. until the closure date.

IV.F.1.a. Cherokee Unit 4 will close no later than December 31, 2028.

IV.F.1.b. ColoWyo Coal Mine will cease coal production no later than December 31, 2031.

IV.F.1.c. Comanche Unit 1 will close no later than December 31, 2022.

IV.F.1.d. Comanche Unit 2 will close no later than December 31, 2025.

IV.F.1.d.(i) Comanche Unit 2 will comply with the following SO2 and NOx emission rates beginning when Comanche Unit 1 closes and until Comanche Unit 2 closes.

NOx Emission Limit	SO2 Emission Limit
0.20 lb/MMBtu (30-day rolling average) 3,050 tpy (12-month rolling average)	0.12 lb/MMBtu (30-day rolling average) 1,830 tpy (12-month rolling average)

IV.F.1.e. Craig Unit 2 will close no later than September 30, 2028.

IV.F.1.f. Craig Unit 3 will close no later than December 31, 2029.

IV.F.1.g. Martin Drake Units 6 and 7 will close no later than December 31, 2022.

IV.F.1.g.(i) 375 tpy NOx, 10 tpy SO2, and 29 tpy of PM/PM10 will be reserved for Drake Units 6 and 7 for netting or offsets. PM/PM10 includes condensable and filterable fractions from this coal-fired unit. Offsets are subject to requirements in Regulation Number 3, Part A, Section V.

IV.F.1.h. Nixon Unit 1 will close no later than December 31, 2029.

IV.F.1.h.(i) 375 tpy NOx, 10 tpy SO2, and 29 tpy of PM/PM10 will be reserved for Nixon Unit 1 for netting or offsets. PM/PM10 includes condensable and filterable fractions from this coal-fired unit. Offsets are subject to requirements in Regulation Number 3, Part A, Section V.

IV.F.1.i. Rawhide Unit 1 will close no later than December 31, 2029.

IV.F.1.i.(i) 200 tpy NOx, 50 tpy SO2, and 50 tpy of PM/PM10 will be reserved for Rawhide Unit 1 for netting or offsets. PM/PM10 includes condensable and filterable fractions from this coal-fired unit. Offsets are subject to requirements in Regulation Number 3, Part A, Section V.

IV.F.2. Emission reductions reserved for netting or offsets provide for reasonable progress toward national visibility goals.

IV.F.3. The following sources are anticipated to remain in operation during the second implementation period. The sources must comply with the applicable emission limits in Section IV. and monitoring, recordkeeping, and reporting requirements in Section V. for the second planning period.

RP Determinations for Colorado Sources**
Emission Unit	NOx Emission Limit	SO2 Emission Limit	Particulate Emission Limit
Nixon Coal Handling	N/A+	N/A+	1.46 tons PM10 per year, unloading, transfer, conveying, processing, and crushing (12-month rolling total) Cessation of coal unloading and crushing no later than 12/31/2029
Nixon- Front Range Power Plant Turbine 1 & Turbine 2	111 ppmvd @ 15% O2 (4-hour rolling average)	N/A*	N/A*
Nixon- Clear Spring Ranch Solids Handling and Disposal Facility (SDHF)	N/A*	186.4 lb/hr (12-month rolling calculation) 52.20 tpy (12-month rolling total) 5,000 ppmv H2S in digester gas	N/A*
Comanche Unit 3	0.08 lb/MMBtu (30-day rolling average) 0.07 lb/MMBtu (annual average)	0.10 lb/MMBtu (30-day rolling average)	0.02 lb/MMBtu 0.012 lb/MMBtu (24-hour average)
Hayden1 Unit 1	0.07 lb/MMBtu (30-day rolling average)	0.13 lb/MMBtu (30-day rolling average)	0.03 lb/MMBtu
Hayden2 Unit 2	0.07 lb/MMBtu (30-day rolling average)	0.13 lb/MMBtu (30-day rolling average)	0.03 lb/MMBtu
Hayden Coal Ash Handling & Disposal and Unpaved Roads	N/A+	N/A+	22.39 tons/yr from coal ash, sorbent loading, unloading only (12-month rolling total)
Cherokee Turbine 5	Applicable limits in 40 CFR 60.4300 Table 1 (NSPS KKKK)	NA*	0.1 lb/MMBtu
Cherokee Turbine 6	Applicable limits in 40 CFR 60.4300 Table 1 (NSPS KKKK)	NA*	0.1 lb/MMBtu

¹ Refer to Section IV.F.6 for applicable means of compliance if the PUC approves the PSCo ERP.

² Refer to Section IV.F.6 for applicable means of compliance if the PUC approves the PSCo ERP.

RP Determinations for Colorado Sources**
Emission Unit	NOx Emission Limit	SO2 Emission Limit	Particulate Emission Limit
Pawnee3 Unit 1	0.07 lb/MMBtu (30-day rolling average)	0.11 lb/MMBtu (30-day rolling average)	0.03 lb/MMBtu
Pawnee Cooling Tower	N/A+	N/A+	36.5 tons per year (12-month rolling total)
Manchief Turbine 1	15 ppmvd @ 15% O2 (1-hr average) 100 ppmvd @ 15% O2 and 186 lb/hr during startup (1-hr average) 100 ppmvd @ 15% O2 and 140 lb/hr during shutdown (1-hr average) 25 ppmvd @ 15% O2 low load operation between March 1 and October 31 (1-hr average)	N/A*	N/A*
Manchief Turbine 2	15 ppmvd @ 15% O2 (1-hr average) 100 ppmvd @ 15% O2 and 186 lb/hr during startup (1-hr average) 100 ppmvd @ 15% O2 and 140 lb/hr during shutdown (1-hr average) 25 ppmvd @ 15% O2 low load operation between March 1 and October 31 (1-hr average)	N/A*	N/A*
CEMEX Lyons Kiln	1.85 lb/ton of clinker (30-day rolling average)	25.3 lb/hr (12-month rolling average)	N/A *
901.0 tpy (12-month rolling total)	95.0 tpy (12-month rolling total)
CEMEX Dowe Flats & Lyons Quarries	N/A+	N/A+	58.4 tpy (Dowe Flats Quarry, 12-month rolling total) Current permitted limit for Lyons Quarry below 10 TPY screening threshold
CEMEX Raw Materials Grinding	N/A+	N/A+	Reporting based on the following factors: 5010 (Raw Mill)- 0.012 lb/ton of clinker 5011 (Raw Mill Air Separator)- 0.032 lb/ton of clinker 5012 (Raw Mill Weigh Feeders)- 0.019 lb/ton of

³ Refer to Section IV.F.7 for applicable means of compliance if the PUC approves the PSCo ERP.

RP Determinations for Colorado Sources**
Emission Unit	NOx Emission Limit	SO2 Emission Limit	Particulate Emission Limit
clinker S013 (Iron/Silica Feed Belt)- 0.0031 lb/ton of clinker
Holcim Florence Kiln	2.73 lb/ton of clinker (30-day rolling average) 2,086.8 tpy (12-month rolling total)	1.3 lb/ton of clinker (30-day rolling average) 721.4 tpy (12-month rolling total)	247.6 tpy (12-month rolling total)
Holcim Florence Quarry	N/A *	N/A *	67.3 tpy (12-month rolling total)
Holcim Florence Finish Mill	N/A+	N/A+	34.3 tpy (12-month rolling total)
GCC Pueblo Kiln	2.70 lb/ton of clinker (30-day rolling average) 2.32 lb/ton of clinker (12-month rolling average) 1,100.0 tpy (12-month rolling total)	N/A *	36.01 tpy (Filterable, 12-month rolling total) 293.56 tpy (Condensable, 12-month rolling total)
GCC Pueblo Clinker Cooler	N/A+	N/A+	33.92 tpy (12-month rolling total)
Boiler Support Facility (Formerly CENC) Boiler 1 (operating on gaseous fuel)	0.20 lb/MMBtu 625.4 tpy (Combined 12-month rolling total for Boilers 1, 2, 4, and 5)	N/A*	N/A *
Boiler Support Facility (Formerly CENC) Boiler 2 (operating on gaseous fuel)	0.20 lb/MMBtu 625.4 tpy (Combined 12-month rolling total for Boilers 1, 2, 4, and 5)	N/A*	N/A *
Boiler Support Facility (Formerly CENC) Boiler 4 (operating on gaseous fuel 7/2/2013)	0.12 lb/MMBtu (30-day rolling average) 242.9 tpy (12-month rolling total, Boiler 4 only) 625.4 tpy (Combined 12-month rolling total for Boilers 1, 2, 4, and 5)	N/A *	N/A *
Boiler Support Facility (Formerly CENC) Boiler 5 (operating on gaseous fuel 4/18/2016)	0.10 lb/MMBtu (30-day rolling average) 256.3 tpy (12-month rolling total, Boiler 5 only) 625.4 tpy (Combined 12-month rolling	N/A *	N/A *
EVRAZ Electric Arc Furnace (EAF)	0.28 lb/ton of steel (30-day rolling average) 189.0 tpy (12-month rolling total)	0.15 lb/ton of steel (30-day rolling average) 101.25 tpy (12-month rolling total)	0.0018 grains/dscf (filterable) 0.0052 grains/dscf (filterable+condensable) 163.11 tpy (12-month rolling total)
EVRAZ Ladle Metallurgy Station (LMS)	84.1 tpy (12-month rolling total)	2 ton/day (3-hour rolling average) 234.3 tpy (12-month rolling total)	N/A *
EVRAZ Round Caster	35.6 tpy (12-month rolling total)	N/A*	19.10 tpy (12-month rolling total)
EVRAZ Seamless Mill Rotary Furnace	169.26 tpy (12-month rolling total)	N/A *	N/A *
EVRAZ Seamless Mill Quench Furnace	Reporting based on 280 lbs/MMscf AP-42 emission factor	N/A *	N/A *
EVRAZ Seamless Mill Tempering Furnace	Reporting based on 280 lbs/MMscf AP-42 emission factor	N/A *	N/A *
EVRAZ Rod/Bar Mill Furnace	0.07 lb/MMBtu 30.28 tpy (12-month rolling total)	N/A *	N/A *
EVRAZ Rail Mill Furnace	0.07 lb/MMBtu (30-day rolling average) 32.34 tpy (12-month rolling total)	N/A *	N/A *
EVRAZ Haul Roads	N/A+	N/A+	Compliance with Fugitive Dust Control Plan
EVRAZ Vacuum Tank Degasser Boiler	16.21 tpy (12-month rolling total)	N/A*	N/A *
EVRAZ Ladle Preheaters	23.91 tpy (12-month rolling total, combined for 6 preheaters)	N/A *	N/A *
Rocky Mountain Bottle Company Furnaces B+ and C (common stack)	157.8 tpy (12-month rolling total)	114.8 tpy (12-month rolling total)	0.27 lb/ton of glass (Performance testing every 5 years) 38.7 tpy (Filterable + Condensable, 12-month rolling total)
Suncor Plant 1 Fluidized Catalytic Cracking Unit Catalyst Regenerator (FCCU)	58.7 ppmvd @ 0% O2 (365-day rolling average)	25 ppmvd @ 0% O2 (365-day rolling average)	85.4 tpy (12-month rolling total)
Suncor Plant 2 Fluidized Catalytic Cracking Unit Catalyst Regenerator (FCCU)	160 ppmvd @ 0% O2 (7-day rolling average) 80 ppmvd @ 0% O2 (365-day rolling average)	37.2 ppmvd @ 0% O2 (365-day rolling average)	53.1 tpy (12-month rolling total)
Suncor Plant 1 Sulfur Recovery Unit Tail Gas Unit (SRC TGU)	N/A*	59.7 tons/year (12-month rolling total)	N/A*
Suncor Plant 2 Sulfur Recovery Unit Tail Gas Incinerator (SRC TGI)	N/A*	1.20% volume SO2 (12-hour rolling average) 271 tons/year (12-month rolling total) 120 tons/year (12-month rolling total) Optimization no later than 12/31/2023 and compliance with 12-month rolling total 12 months after optimization is complete and no later than 12/31/2024. Application for permit modification and limits based on operating data no later than 18 months after optimization project implementation or Comply with alternative in Section IV.F.7.c. and Section V.A.1.d.(ii)(C).	N/A*
Suncor Plant 1 Main Plant Flare	162 ppmv H2S (3-hour rolling average)	N/A*
Suncor Heater H-11	12.78 tpy (12-month rolling total)	N/A*	N/A*
Suncor Heater H-17	24.83 tpy (12-month rolling total)	N/A*	N/A*
Suncor Heater H-27	32.84 tpy (12-month rolling total)	N/A*	N/A*
Suncor Heaters H-28/29/30	20.40 tpy (12-month rolling total)	N/A*	N/A*
Suncor Heater H-37	10.41 tpy (12-month rolling total)	N/A*	N/A*
Suncor Heater H-101	55.85 tpy (12-month rolling total)	N/A*	N/A*
Suncor Heater H-402	21.16 tpy (12-month rolling total)	N/A*	N/A*
Suncor Heater H-2101	52.19 tpy (365-day rolling total)	N/A*	N/A*
Suncor Boiler 4	0.06 lb/MMBtu (30-day rolling average)	N/A*	N/A*
Suncor Boiler 505	0.044 lb/MMBtu (30-day rolling average)	N/A*	N/A*

**Referenced Federal Regulations are listed in the "Federal Regulations Adopted by Reference" section at the beginning of Regulation Number 23.

*Emissions did not meet the screening threshold established by the Regional Haze program. Thus, this point was not subject to four-factor analysis for Colorado's Round 2 regional haze SIP planning period.

+This pollutant is not emitted.

IV.F.4. Each source listed in the table must comply with the limits and averaging times, record keeping, and reporting requirements in addition to its applicable permit requirements as expeditiously as practicable, but in no event later than five years after EPA approval of Colorado's Round 2 SIP for regional haze. Sources must maintain control equipment or operational practices required to comply with the limits and averaging times, record keeping, and reporting requirements, and establish procedures to ensure that such equipment or operational practices are properly operated and maintained.

IV.F.5. Hayden Units 1 and 2 must comply with the applicable emission limits in Section IV. and monitoring, recordkeeping, and reporting requirements in Section V. if the PUC does not approve the ERP/CEP or until the approved closure date. Contingent upon PUC approval of the proposed PSCo Electric Resource Plan and Clean Energy Plan in 2022 and specific approval of the proposed closure dates in PUC Docket No. 21A-0141E, Hayden Unit 1 will close no later than December 31, 2028 and Hayden Unit 2 will close no later than December 31, 2027. If closure is approved by the PUC, 28 tpy of SO2, 22 tpy of PM10, and 135 tpy of NOx will be reserved for netting or offsets. Offsets are subject to requirements in Regulation Number 3, Part A, Section V.

IV.F.6. Pawnee Unit 1 must comply with the applicable emission limits in Section IV. and monitoring, recordkeeping, and reporting requirements in Section V. if the PUC does not approve the ERP/CEP or until the approved closure date. Contingent upon PUC approval of the proposed PSCo Electric Resource Plan and Clean Energy Plan in 2022 and specific approval of the proposed date in PUC Docket No. 21A-0141E, Pawnee Unit 1 will convert from coal to natural gas fuel no later than December 31, 2028. If approved, some amount of emissions may be reserved for netting or offsets. Offsets are subject to requirements in Regulation Number 3, Part A, Section V.

IV.F.7. Suncor Plant 2 Sulfur Recovery Unit SO2 optimization or alternative control requirements

IV.F.7.a. Beginning February 14, 2022, the Plant 2 Sulfur Recovery Unit Tail Gas Incinerator (SCR TGI) will meet a 1.20% volume SO2 (12-hour rolling average) and an annual SO2 limit of 271 tons per year (12-month rolling total).

IV.F.7.b. The owner/operator must implement optimization of air flow through the Plant 2 Sulfur Recovery Unit (SRU) no later than December 31, 2023. The Plant 2 Sulfur Recovery Unit Tail Gas Incinerator (SRC TGI) will meet an SO2 limit of 120 tons per year (12 month rolling total) within twelve (12) months after optimization and by no later than December 31, 2024.

IV.F.7.c. If the owner/operator fails to implement air flow optimization or fails to achieve the limit in Section IV.F.7.b. by the specified timeline, the owner/operator will install SUPERCLAUS 2+1 on the SRU by no later than December 31, 2028. The SRU must achieve at least a 98.65% sulfur recovery efficiency, by no later than December 31, 2029. The SRC TGI will meet an SO2 limit of 120 tons per year (12-month rolling total) within twelve (12) months after SUPERCLAUS 2+1 installation and by no later than December 31, 2029.

5 CCR 1001-27-A-IV

44 CR 02, January 25, 2021, effective 2/14/2021

45 CR 01, January 10, 2022, effective 1/30/2022