# Minnesota Pollution Control 

# Agency

520 Lafayette Road North 

### I St. Paul, MN 55155-4194 

### 1 651-296-6300 

### 1 800-657-3864 

### 1 651-282-5332 TTY 

### I www.pca.state.rnn.us



### December 30,2009

Mr. Bharat Mathur Acting Regional Administrator (AR-19J) 

### U. S



## . Environmental Protection Agency Region V 77 West Jackson Boulevard Chicago, Illinois 60604



### RE: State Implementation Plan for Regional Haze

Dear Mr. Mathur:

The Minnesota Pollution Control Agency (MPCA) hereby submits to the U.S. Environmental Protection Agency (EPA) a revision to Minnesota's State Implementation Plan (SIP), pursuant to the federal Regional Haze Rule (40 CFR 5 1.300
- 

### 5 1.309).

This revision describes how Minnesota intends to implement the Regional Haze Rule in order to reduce regional haze in the Boundary Waters Canoe Area Wilderness and Voyageurs National Park, as well as in Class I 

### areas outside of Minnesota where visibility is impacted by emissions from Minnesota.



### In addition to fulfilling the SIP requirement under the regional haze rule, this revision meets Minnesota's requirements under Clean Air Act Section 1 

### lO(a)(2)(D)(i) for a SIP that contains adequate provisions demonstrating that emissions from Minnesota will not interfere with

measures required for any other state to meet the implementation requirements related to regional haze and visibility.

Please contact Catherine Neuschler, of my staff, at 651-757-2607, if you have any questions regarding this submittal.

Sincerely,

3 

### Paul Eger Commissioner

Enclosures

cc: Kathleen D 'Agostino, EPA Region V 

### (w/enclosures)

St.Paul ( Brainerd 

### I Detroit Lakes 

### I Duluth 

### 1 Mankato / Marshall 

### I Rochester 

### I Willmar 

### 1 Printed on 100%post-consumer recycled paper

b

# Regional Haze

State Implementation Plan

December 2009[This page intentionally left blank]i 

### Executive Summary

The state of Minnesota is home to two federal Cla ss I areas, the Boundary Waters Canoe Area Wilderness (BWCAW) and Voyageurs National Park (VNP), locat ed along the state’s border with Canada. In compliance with the Regional Haze Rule promulgate d in 1999, the Minnesota Pollution Control Agency (MPCA) is submitting to the U.S. Environmental Pr otection Agency (EPA) this State Implementation Plan (SIP) to reduce haze and meet the goal of no man-made visibility impairment in the Class I areas by 2064.

Current visibility conditions, in deciviews, are:

Baseline Conditions Natural Conditions Class I area 20% Worst Days 20% Best Days 20% Worst Days 20% Best Days

BWCAW 19.9 6.4 11.6 3.4

VNP 19.5 7.1 12.2 4.3

The main pollutants contributing to visibility impa irment in Minnesota’s Class I areas are ammonium sulfate, ammonium nitrate, and organic carbon. Modeling indicates that the organic carbon is biogenic, so the MPCA chose to focus control measures on th e anthropogenic emissions of nitrogen oxides (NO X ) and sulfur dioxide (SO 2 ) that lead to formation of nitrate and sulfate. The main contributors of SO 2 are electric generating units (EGUs), while the main contributors of NO X are motor vehicles, both on and off road. The main states whose emissions contribute to visibility impairment in BWCAW and VNP are: Minnesota, Wisconsin, Illinois, Iowa, Missouri, and North Dakota.

Minnesota has several sources subject to Best Av ailable Retrofit Technology (BART) requirements, namely EGUs and taconite pellet furnaces. Many of Minnesota’s EGUs are planning or have begun emission reduction projects. The MPCA made BART determinations for each subject-to-BART EGU, though in many cases already planned controls were deemed equivalent to BART. For the taconite furnaces, BART for NO X is an operating standard of good co mbustion practices in combination with some proposed process changes, while BART for PM is equivalent to the taconite Maximum Available Control Technology (MACT) standard, and BART for SO 2 is generally existing particulate scrubbers optimized for SO 2 removal. The MPCA is also requiring application of better emission measurement systems to set a NO X BART emission limit, SO 2 limits at lines that burn high sulfur fuels, and determine compliance. Final BART emission limits, where not al ready available, will be submitted prior to the Five Year SIP Assessment.

Minnesota’s long-term strategy includes the implemen tation of several federal programs, including BART and the Clean Air Interstate Rule (CAIR), over the next several years in Minnesota and the surrounding states. It also includes a target for a 30% reduction in combined NO X and SO 2 emissions by 2018 from point sources in Northeastern Minnesota that emit over 100 tons per year of either NO X or SO 2
.
Based on the emission reductions currently known to be reasonable, Minnesota has established the following reasonable progress goals, in deciviews:

Class I area 20% Worst Days 20% Best Days BWCAW 18.6 6.4 VNP 18.9 7.1

Minnesota will continue to evaluate control strategies that have shown the potential to result in reasonable emission reductions, and expects the contributing states to do the same. Due to this ongoing evaluation, Minnesota expects to submit additional control stra tegies and a revised reasonable progress goal in the Five Year SIP assessment.ii [This page intentionally left blank]iii Executive Summary ............................................................................................................. .......................... i Regional Haze Glossary of Terms ............................................................................................... .............. viii Chapter 1. Background and Overview ............................................................................................ ............ 11 General Background / History of Federal Regional Haze Rule .............................................................. 11 Minnesota’s Cl ass I ar eas ..................................................................................................... .................. 12 Chapter 2. General Planning Provisions ....................................................................................... ............. 13 Table 2.1: Stakeholder and Public Meetings .................................................................................... .. 13 Chapter 3. Regional Planni ng and State Consultation .......................................................................... ..... 15 Regional Planning.............................................................................................................. ..................... 15 Figure 3.1: Geographical Areas of Regional Planning Organizations ............................................... 15 Consultation Across RPOs ...................................................................................................... ............... 16 Technical C onsultation ........................................................................................................ ............... 16 Table 3.1: Technical Committee Structure for CENRAP and MRPO; Minnesota Participants ....... 16 State Consultation ............................................................................................................ ....................... 17 Northern Class I Ar ea Consultation ............................................................................................ ....... 18 Participants .................................................................................................................. ................... 18 Process ....................................................................................................................... .................... 18 Chapter 4. State and Federa l Land Manager Coordination ....................................................................... . 20 Consultation During SIP Development ........................................................................................... ....... 20 Official Notice and Consultation .............................................................................................. .............. 21 Chapter 5. Assessment of Visibility Conditions in Class I areas .............................................................. . 22 Baseline, Natural and Current Conditions ...................................................................................... ........ 22 Figure 5.1: Uniform Rate of Progress (URP) to Achieve Natural Conditions in 60 Years ................ 22 Default and refined values for na tural visibility conditions ............................................................... 23 Consultation regarding the visibility metrics ................................................................................. .... 24 Baseline Visibility Conditions ................................................................................................ ................ 24 Table 5.1: Monthly fS(RH) and fL(RH) values ................................................................................. 25 Natural Visibility Conditions ................................................................................................. ................. 27 Table 5.2: Visibility Metrics fo r Minnesota’s Class I areas ............................................................... 27 Table 5.3: Adjusted Visibility Metri cs in dv for Northern Class I areas ............................................ 28 Table 5.4: Northern Class I areas URP in dv; Adjusted Data ............................................................ 28 Figure 5.2: Uniform Rate of Progress for BWCAW .......................................................................... 29 Figure 5.3: Uniform Rate of Progress for VNP .................................................................................. 29 Updated Visibility Conditions ................................................................................................. ............... 30 Table 5.5: Visibility Conditions 2005 - 2007 .................................................................................. ... 30 Chapter 6. Monitoring Strategy ............................................................................................... .................. 31 Current Monitoring Strategy ................................................................................................... ............... 31 Figure 6.1 CENRAP IMPROVE and IMPROVE Protocol Sites ....................................................... 32 Table 6.1: Active Minnesota PM 2.5 Monitoring Sites ........................................................................ 32 Table 6.2: Active Minnesota PM 10 Monitoring Sites ......................................................................... 33 Future Monitoring Strategy .................................................................................................... ................ 33 Special Monitoring Studies .................................................................................................... ............ 34 Chapter 7. Emission Inventory.................................................................................................. .................. 35 State Inventory – 2002 ........................................................................................................ .................... 35 Table 7.1: Minnesota 2002 Baseline Emissions Inventory Summary (tpy) ....................................... 35 Table 7.2: Minnesota 2005 Emissions Summary (tpy) ...................................................................... 36 Inventory Methodology ......................................................................................................... ............. 36 Modeling Inventory ............................................................................................................ .................... 36 Chapter 8. Modeling ........................................................................................................... ........................ 37 The Modeling System ........................................................................................................... .................. 39 Model Year Chosen ............................................................................................................. ................... 39iv Conceptual Description ........................................................................................................ .................. 40 Modeling/Analysis Protocol .................................................................................................... ............... 40 Emissions Preparations & Results .............................................................................................. ............ 41 The Base Year Inventory – 2002 ................................................................................................ ............ 41 The Future Year Inventory – 2018 .............................................................................................. ........... 41 Table 8.1: Minnesota Adjustments and Corrections to IPM Version 3.0 .......................................... 42 Table 8.2: IPM2.1.9 (VISTAS), and IP M3.0 “base” and “will do” Alterations ............................... 43 Minnesota Growth Changes in Minneso ta(MRPO) 2018 Modeling Inventory ................................. 44 Controls on Future Year Inventory ............................................................................................. ....... 44 Table 8.3: Annual Minnesota 2002 and 2018 Emissions Totals in Tons .......................................... 45 Alternative EGU Emission Proj ections without CAIR. ..................................................................... 45 Table 8.4: Future Year Control Assu mptions with and without CAIR .............................................. 46 MRPO Quality Assurance for Emissions Inventories ........................................................................ 47 Air Quality/Meteorology Pr eparations and Results .............................................................................. .. 48 Figure 8.1: Modeling Domains ................................................................................................. ........ 49 Performance Evaluation fo r Air Quality Models ................................................................................. ... 49 Meteorological Model Performance fo r the Base Year (2002) Data ................................................. 49 Air Quality Model Performance for the Base Year (2002) Inventory ................................................ 49 Comparison of Model Performance Evaluation for Nitrate on Individual Days ................................ 50 Figure 8.2: Observations and Predictions by Minnesota (MRPO) and CENRAP ................................... 50 Implications of the Performance Evaluation .................................................................................... .. 51 Exploration of Potential Strategies fo r Demonstrating Reasonable Progress ......................................... 52 Figure 8.3: Contributions to Extinction in 2018 at BWCAW by Region for W20% Days ............... 53 Figure 8.4: Contributions to Extinction in 2018 at VNP by Region for W20% Days ....................... 53 Figure 8.5: % Contribution of NE and Rest of MN to BWCAW and VNP for W20% Days ........... 54 Figure 8.6: % Contribution of NE and Rest of MN to Max and Min Receptors for W20% Days .... 55 Figure 8.7: MN Contributions at Receptor s Placed Throughout Class I Areas in 2018 ................... 55 Table 8.5: 2018 Annual Potentially Reasonable Control Measures Emissions for Point Sources .... 57 Figure 8.8: BWCAW 36-km Potentially R easonable Emissions Reduction Results ........................ 58 Figure 8.9: VNP 36-km Potentially R easonable Emissions Reduction Results ................................ 58 Reasonable Progress Stra tegy and Goals ........................................................................................ ........ 59 Table 8.6: Reasonable Progress Goals for BWCAW and VNP ........................................................ 59 Figure 8.10: BWCAW 36-km Minnesota (MRPO) Results .................................................................... 59 Figure 8.11: VNP 36-km Minnesota (MRPO) Results ........................................................................... 60 Supplemental Analysis/ Weight of Evidence Determination ................................................................. 60 Table 8.7: Visibility Projections to 2018 for the W20% Days ......................................................... 61 Table 8.8: Relative Response Factors to 2018 for the W20% Days ................................................. 61 Table 8.9: Visibility Projections to 2018 usi ng 2002 and 2005 Mete orology for the W20% Days .. 63 Table 8.10: RRFs for 2018 using 2002 a nd 2005 Meteorology for the W20% ................................ 64 Data Access ................................................................................................................... ......................... 64 Chapter 9. Best Availa ble Retrofit Technology ................................................................................. ......... 65 BART-Eligible Sources in Minnesota ............................................................................................ ........ 65 Table 9.1: Minnesota Facilities with BART-eligible Units ................................................................ 65 Determination of Sources Subject to BART ...................................................................................... .... 67 Table 9.2: Facilities with Units Subject to BART in Minnesota ........................................................ 68 Determination of BART Requirement s for Subject-to-BART Sources ................................................. 69 EGU BART Determinations ....................................................................................................... ....... 69 Table 9.3: Planned Control Upgrades by EGUs a nd PM Contribution to Visibility Impairment ...... 70 Table 9.4: NO X and SO 2 BART Determinations for EGUs ............................................................... 71 Visibility Improvement ........................................................................................................ .......... 71 Taconite BART Determinations .................................................................................................. ....... 71v Table 9.5: Characteristics of Minn esota Taconite Pellet Furnaces ................................................... 72 BART Alte rnative .............................................................................................................. ................ 74 BART Implementation ........................................................................................................... ............ 75 Table 9.6: SO 2 BART Determinations for Units Where a Full BART Analysis Was Conducted ..... 77 Table 9.7: NO X BART Determinations for Units Where a Full BART Analysis Was Conducted .... 80 Chapter 10. Reasonable Progress Goals and Long-Term Strategy ............................................................. 83 Consultation .................................................................................................................. .......................... 83 Basis for emission reduction obligations ...................................................................................... .......... 83 Baseline inventory ............................................................................................................ .................. 84 Minnesota’s Impact on Class I areas ........................................................................................... ....... 84 Table 10.1: Class I areas Im pacted by Minnesota .............................................................................. 84 States Impacting Minneso ta’s Class I areas .................................................................................... ... 85 Table 10.2: Percentage Contributions by State to Light Extinction ................................................... 85 Pollutants and Sources Impacting Minnesota’s Class I areas ............................................................ 86 Figure 10.3: 2002 Observations and 2018 Projec tions in Extinction by Species W20% Days.......... 86 Figure 10.4: NO X and SO 2 Emissions in Minnesota by Source Category .......................................... 86 Figure 10.5: BWCAW 2018 Extinction by Sector for each Specie, W20% Days ............................. 87 Figure 10.6: VNP 2018 Extinction by Sector for each Specie, W20% Days ..................................... 87 Guidance in Determining RPG ................................................................................................... ............ 88 Approach to Determining RPG ................................................................................................... ........... 88 Share of Emission Reductions .................................................................................................. .............. 91 Minnesota’s Long-Term Strategy ................................................................................................ ........... 91 Emission reductions due to ongoing air pollution programs .............................................................. 91 Clean Air Interstate Rule (CAIR) .............................................................................................. .... 92 Table 10.3: IPM 3.0 Predictions for 2018 ...................................................................................... .... 92 Best Available Retrofit Technology (BART) ................................................................................ 93 Other Federal Programs ........................................................................................................ ......... 94 PM 2.5 and Ozone SIPs ............................................................................................................... ..... 94 Additional Emission limitations and schedules of compliance .......................................................... 94 Plan for Emission Reductions in Northeast Minnesota ................................................................. 94 Table 10.4: NE Minnesota Emission Reduction Target ..................................................................... 96 Table 10.5: BART and Northeast Minnesota Plan Timeline ............................................................. 98 Measures to mitigate the impact s of construction activities ............................................................... 99 Source retirement and replacement schedules .................................................................................. 100 Agricultural and forestry smoke management ................................................................................. 10 0 Impact of Fires on Visibility ................................................................................................. ....... 100 Table 10.6: W20% Days with Highest OC and EC Light Extinction .............................................. 102 Agricultural Smoke Management ................................................................................................ 102 Forestry Smoke Management ..................................................................................................... . 103 Future of SMP and Fires ....................................................................................................... ....... 105 Enforceability of emission limitations and control measures ........................................................... 105 Anticipated net effect on visibility resulti ng from projected changes to emissions ......................... 106 Potential Future Projects and Impacts ......................................................................................... ..... 106 Reasonable Pr ogress Goals ..................................................................................................... .............. 107 Table 10.7: Reasonable Progress Goals for Class I areas ................................................................ 107 Factors Impacting RPG ......................................................................................................... ........... 107 International Emissions ....................................................................................................... ......... 107 Emissions from Contributing States ............................................................................................ 107 Table 10.8: Alternate Go als for Class I areas ................................................................................. .. 109 Table 10.9: Visibility Conditions, URP and RPG for Minnesota’s Class I areas (dv) ..................... 110 Steps in Reviewing Control Strategies and Revising RPG .............................................................. 110vi Timeline for Reviewing Control Strategies ..................................................................................... . 111 Chapter 11. Periodic Plan Revisions and Determination of Adequacy.................................................... 112 2018 SIP Revision ............................................................................................................. ................... 112 Five Year Report .............................................................................................................. .................... 112 Actions to be Taken Prio r to Five Year Report ................................................................................ 112 Table 11.1: Activities to be Completed Pr ior to Five Year SIP Assessment ................................... 112 Contents of Five Year Report .................................................................................................. ......... 113 BART Limits ................................................................................................................... ............ 113 Northeast Minnesota Plan Evaluation an d Taconite Retrofit Requirements................................ 113 Reasonable Progress Update .................................................................................................... .... 114 Adequacy Determination ........................................................................................................ ..... 114 Appendix 1.1: Benefits of Improved Visibility ................................................................................. ....... 118 Appendix 1.2: EPA SIP Submittal Checklist ..................................................................................... ....... 122 Appendix 2.1: Documentation of legal author ity and compliance with State procedure.......................... 128 Appendix 2.2: Public Notices ................................................................................................. ................. 13 4 Appendix 2.3: Certification of Public Me eting ................................................................................. ........ 15 4 Appendix 2.4: Public Comments on Draft Haze SIP and MPCA Response ............................................. 16 5 Appendix 2.5: Interim Comments on Revised Regional Haze SIP and MPCA Response ....................... 32 8 Appendix 2.6: Public Comments on Revised Regional Haze SIP an d MPCA Response ......................... 39 8 Appendix 3.1: Summary of Technical Information ................................................................................ .. 592 Appendix 3.2: Formal Consultation Letter ...................................................................................... ......... 623 Appendix 4.1: Agency C ontacts Provided to FLMs ................................................................................ . 650 Appendix 5.1: Determination of Visibility Conditions .......................................................................... ... 651 Appendix 5.2: Impact of Missing Data on Worst Days at Midwest Northern Class I areas ..................... 653 Table 5.2.1: Northern Class I area Days Exceeding p80, Despite Missing Components ................ 654 Table 5.2.2: Comparison of Average of 20% Worst Days ............................................................... 65 4 Figure 5.2.1: BWCAW 2000 Light Extinction by Species (20% Worst Days) ............................... 65 5 Figure 5.2.2: BWCAW 2001 Light Extinction by Species (20% Worst Days) ............................... 65 5 Figure 5.2.3: BWCAW 2002 Light Extinction by Species (20% Worst Days) ............................... 65 6 Figure 5.2.4: BWCAW 2003 Light Extinction by Species (20% Worst Days) ............................... 65 6 Figure 5.2.5: BWCAW 2004 Light Extinction by Species (20% Worst Days) ............................... 657 Figure 5.2.6: BWCAW 2005 Light Extinction by Species (20% Worst Days) ............................... 657 Figure 5.2.7: VNP 2000 Light Extinction by Species (20% Worst Days) ....................................... 658 Figure 5.2.8: VNP 2001 Light Extinction by Species (20% Worst Days) ....................................... 658 Figure 5.2.9: VNP 2002 Light Extinction by Species (20% Worst Days) ....................................... 659 Figure 5.2.10: VNP 2003 Light Extinction by Species (20% Worst Days) ..................................... 659 Figure 5.2.11: VNP 2004 Light Extinction by Species (20% Worst Days) ..................................... 66 0 Figure 5.2.12: VNP 2005 Light Extinction by Species (20% Worst Days) ..................................... 66 0 Appendix 5.3: Additional Visibility Metrics

................................................................................... ......... 661 Table 5.3.1: Northern Class I areas Visibility Metrics in dv; Old IMPROVE Equation ................. 661 Table 5.3.2: Northern Class I areas URP in dv; Old IMPROVE Equation ...................................... 661 Table 5.3.3: Northern Class I areas Visibilit y Metrics in dv; New IMPROVE Equation ................ 66 1 Table 5.3.4: Northern Class I areas URP in dv; New IMPROVE Equation .................................... 66 2 Appendix 6.1: Monitoring and Data Analy s is to Support the Regional Haze Rule ................................. 66 3 Appendix 7.1: Minnesota’s 2002 Em issi ons Inventory and Methodology .............................................. 68 2 Appendix 9.1: Identification of BART-Eligible Sour ces in Minnesota ................................................... 69 7 Table 9.1.1: Facilities Asked to Identify BART-Eligible Sources ................................................... 69 8 Appendix 9.2: BART Strategy, Modeling Protocols, Results, and Analyses .......................................... 705 Appendix 9.3: BART Determinations by MPCA – Taconite Facilities .................................................... 706 Table 9.3.1 U.S. Taconite Iron Ore Facility Location ..................................................................... 706 Figure 9.3.1: Diagram of Strai ght-Grate Induration Furnace ........................................................... 709vii Figure 9.3.2: Diagram of a Grate-Kiln Induration Furnace .............................................................. 710 Table 9.3.2: Characteristics of Minn esota Taconite Pellet Furnaces ............................................... 711 Appendix 9.4: BART Determinations by MPCA – EGU ......................................................................... 836 Table 9.4.1: Subject-to-BART EGUs ............................................................................................. . 83 7 Table 9.4.2: EGUs BART Proposals for PM ................................................................................... 83 7 Table 9.4.3: Visibility Impact of Direct PM Emissions ................................................................... 83 8 Appendix 9.5: BART Visi bility Modeling ........................................................................................ ....... 91 4 Appendix 9.6: Minnesota BART Rules ........................................................................................... ........ 93 4 Appendix 9.7: Adm inistrative Orders .......................................................................................... ............ 94 0 Appendix 10.1: Contribut ion Assessment Analysis............................................................................... .. 974 Table 10.1.1: MRPO Estimated Contributions to Light Extinction – Percentages .......................... 974 Figure 10.1.1: Back Trajectories for Light Extinction, 20% Worst Days ........................................ 975 Figure 10.1.2: AOIs for Minn esota’s Class I areas .......................................................................... 976 Figure 10.1.3: PSAT 2018 W20% Days Light Extinction from Minnesota..................................... 977 Figure 10. 1.4: PSAT 2018 W20% Days Light Extinction at BWCAW by Source Region ............. 97 8 Figure 10. 1.5: PSAT 2018 W20% Days Light Extinction at VNP by Source Region ..................... 97 9 Appendix 10. 2: Minnesota Statute 216B.1692 .................................................................................... ..... 980 Appendix 10. 3: EGU Air Emission Permits ....................................................................................... ...... 98 3 Appendix 10.4: Concept Plan for Addressing Majo r Point Sources in Northeaster n Minnesota ............. 98 5 Appendix 10.5: Factor Analysis of Control Strategies (EC/R Report) ..................................................... 993 Appendix 10.6: CENRAP Cost Curve Analysis of Control Strategies ..................................................... 994 Table 10.6.1: NO X Controls, Q/5D for BWCAW or VNP ............................................................... 995 Table 10.6.2: SO2 Controls, Q/5D for BWCAW or VNP ............................................................... 996 Appendix 10.7: Fire Emissions and Impact of Fire on Visibility ............................................................. 998 Figure 10.7.1: HYSPLIT and Fire Maps for 6/1/2002 ..................................................................... 999 Figure 10. 7.2: HYSPLIT and Fire Map for 6/28/02 ......................................................................... 99 9 Figure 10. 7.3: HYSPLIT Back Trajectories for 9/30/2000 .............................................................1000 Figure 10. 7.4: HYSPLIT Back Trajectories for 6/5/2003 ............................................................... 1001 Figure 10. 7.5: HYSPLIT Back Trajectories for 8/7/2003 .............................................................. 100 2 Figure 10. 7.6: Canadian Fire Hotspots for 8/5/2003 ...................................................................... 100 2 Figure 10.7.7: HYSPLIT Back Trajectories for 8/25/2003 ............................................................ 1003 Figure 10.7.8: Canadian Fire Hotspots for 8/23/2003 .................................................................... 1003 Figure 10.7.9: HYSPLIT Back Trajectories for 7/26/2004 ............................................................ 1004 Figure 10.7.10: CWFIS Fire Hot Spots for 7/25/2004 ................................................................... 1005 Figure 10.7.11: CWFIS Fire Hot Spots for 7/27/2004 ................................................................... 1005 Appendix 10.8: EPA’s Certification of Smoke Management Plan ......................................................... 1007 Referen ces and Guidance Documents ............................................................................................. ........ 100 9viii [This page intentionally left blank]ix 

### Regional Haze Glossary of Terms

• 20% Best Days – The days with the best vi sibility over the baseline or future period

• 20% Worst Days – The days with the poorest visibility over the baseline or future period

• BACT – Best Available Control Technology – Re quired for major sources or modifications under PSD.

• BART – Best Available Retrofit Technology – Requi res controls on certain types of sources built between 1962 – 1977 and generally grandfat hered under most Clean Air Act programs

• Baseline Conditions – Current visibility conditions, or visibility conditions over the baseline period

• Baseline Period – As required by rule, the years 2000 - 2004

• CAIR – Clean Air Interstate Rule – A cap and trade program covering 27 Eastern states to reduce emissions of NO X and SO 2 from power plants.

• CAMx – Comprehensive Air quality Model with eXtensions - A computer modeling system for the integrated assessment of gaseous and particulate air pollution.

• CEMs – Continuous Emission Monitoring System

• CENRAP – Central Regional Air Planning Associa tion – Regional planning organization covering the central portion of the U.S, including states and tribal areas of Nebraska, Kansas, Oklahoma, Texas, Minnesota, Iowa, Missouri, Arkansas, and Louisiana

• CIRA – Cooperative Institute for Research in the Atmosphere – Research institute contracted by the National Park Service to work on visibility information, including IMPROVE and VIEWS

• CMAQ – Community Multi-Scale Air Quality model – Air Quality model used by many states and RPOs for estimating visibility conditions.

• Deciview – Visibility unit used in the Regional Haze SIP; similar to a decibel, one deciview is the smallest change in visibility that is perceptive to the human eye.

• EMS – Emissions Modeling System - Generates hour ly speciated emissions on a gridded basis for input to an air quality model.

• EGUs – Electric Generating Units – Utility power plants

• HYSPLIT4 - HYbrid Single-Particle Lagrangian Integrated Trajectory – Model for computing simple air parcel trajectories to complex dispersion and deposition simulations.

• IMPROVE – Interagency Monitoring of Protected Visual Environments – Cooperative program to monitor visibility in the Class I areas, http://vista.cira.colostate.edu/improve/

• LADCO – Lake Michigan Air Directors Consortium – Air quality planning organization for Illinois, Indiana, Michigan, Ohio, and Wisconsin; conducts air quality technical assessments

• MM5 – Mesoscale Meteorological Model – A numerical model for weather prediction on scales from continental to one km.

• Model Inventory – The emission inventory used in the atmospheric chemistry and transport modeling, usually different from the emission inventory submitted to the NEI.

• MRPO – Midwest Regional Planning Organization – Regional planning organization for regional haze, covering the Midwest states (Illinois, Indiana, Michigan, Ohio, and Wisconsin)

• Natural Conditions – Estimation of visibility without any man-made influence

• NEI – National Emission Inventory – Compilation of emissions by pollutant, source category, and geographic for each state; required by the EPA on a three-year cyclex • PiG – Plume in Grid – Tool within the modeling system to track individual plume segments from each point source, rather than immediately dispersing the individual point sources emissions into the grid cell.

• PSAT – Particulate Matter Source Apportionment Technology – Part of CAMx that tracks the original source of particulate species by geographic region and source category

• PSD – Prevention of Significant Deterioration – A program established by the Clean Air Act that limits the amount of additional air pollution that is allowed in Class I and Class II areas.

• RPG – Reasonable Progress Goal – Visibility goal for 2018 set by the state in the SIP; usually used to refer to the visibility goal for the 20% worst days

• SCC - Source Classification Code – Code used by EPA to classify different types of air quality inventory emission sources.

• SMOKE – Sparse Matrix Object Kernel Emission – EPA processor for preparation of emission data.

• SMP – Smoke Management Plan – Plan to reduce the impact of prescribed fire on air quality.

• URP – Uniform Rate of Progress – The constant rate of visibility improvement needed to meet natural conditions on the 20% worst days in 2064

• VIEWS – Visibility Information Exchange Web System – Web repository of visibility information, http://vista.cira.colostate.edu/views/

For a more detailed haze glossary, see: http://vista.cira.colostate.edu/improve/Education/Glossary/glossary.htm11 

### Chapter 1. Background and Overview

General Background / History of Federal Regional Haze Rule In amendments to the Clean Air Act (CAA) in 1977, Congress added Section 169 (42 U.S.C. § § 7491), setting forth a national visibility goal of restoring pristine conditions in national parks and wilderness areas. These areas were designated as Class I areas, because of their general nature as areas most free from air pollution and visibility problems. Section 169 states:

“Congress hereby declares as a national goal the prevention of any future, and the remedying of any existing, impairment of visi bility in mandatory Class I Federal areas which impairment results from man-made air pollution.”

Over the following years modest steps were taken to address the visibility problems in Class I areas. The control measures taken mainly addressed “plume blight,” the visual impairment of air quality that manifests itself as a coherent plume from specific po llution sources, such as a power plant smoke stack, emitting pollutants into a stable atmosphere. These plume blight control measures did little to address regional haze issues in the Eastern United States.

When the CAA was again amended in 1990, Congr ess added Section 169B (42 U.S.C. § § 7492), authorizing further research and regular assessments of the progress made towards visibility goals. In 1993, the National Academy of Scien ces concluded “current scientific know ledge is adequate and control technologies are available for taking regulatory action to improve and protect visibility.” 1

Section 169B(f) of the CAA authorized creation of vi sibility transport commissions and set forth their duties, and specifically mandated creation of the Grand Canyon Visibility Transport Commission (GCVTC) to make recommendations to the U.S. Environmental Protection Agency (EPA) for the region affecting visibility in Grand Canyon National Park. Af ter four years of research and policy development, GCVTC submitted its report to EPA in June 1996. 2 This report, as well as other research reports prepared by GCVTC, contributed information to EPA’s developm ent of the federal Regional Haze Rule (RHR).

EPA’s Regional Haze Rule was adopted July 1, 1999 , and went into effect on August 30, 1999. The RHR is intended to achieve national visi bility goals by 2064. The rulemaki ng addressed the combined visibility effects of various pollution sources over a wide geogra phic region, meaning that many states – even those without Class I areas – are required to participate in haze reduction efforts. EPA designated five Regional Planning Organizations (RPOs) to assist with th e coordination and cooperation needed to address visibility and haze issues. Those states and tribes that make up the midsection of the contiguous United States, including Minnesota, were designated as the Central Regional Air Planning Association (CENRAP).

On May 24, 2002 the U. S. Court of Appeals, D. C. Circuit Court, ruled on a challenge to the RHR brought by the American Corn Growers Association. The Court denied industry’s challenge to the rule’s goals of natural visibility and no degradation, and remanded to EPA the Best Available Retrofit Technology (BART) provisions of the rule. 3

EPA proposed rule revisions pursuant to the remand, and final amendments to the Regional Haze Rule and guidelines for BART were finalized on June 15, 2005. In the initia l rule, EPA had required states to consider the collective impact of BART sources on visibility. The Court ruled that this unfairly

1 National Research Council, Commission on Geosciences, Environment and Resources, 1993.

2 GCVTC, 1996.

3 American Corn Grower s Association v. EPA.12 constrained the states’ otherwise broad authority to make BART determinati ons, and so subsequent revisions give states more discretion and provide a pr ocess for states to consider BART determination on a facility-by-facility basis.

Minnesota’s Class I areas
Minnesota has two Federal Class I areas within its borders: the Boundary Waters Canoe Area Wilderness and Voyageurs National Park.

The Boundary Waters Canoe Area Wilderness (BWCAW) is part of the Superior National Forest, which was established by Presidential pr oclamation in 1909. BWCAW is a 1-million acre federally designated wilderness; it is the only wilderness of substantial size east of the Rocky Mountains and north of the Everglades and is the most heavily used wildern ess area in the United States with about 200,000 annual visitors. The Boundary Waters Canoe Area Wilder ness Act, which banned logging and mining, phasedout snowmobiling, and limited motorboat use in BWCAW, was signed by President Jimmy Carter on October 21, 1978. 4

Voyageurs National Park (VNP) is a water-based park named for the French-Canadian voyageurs that traveled through the area in canoes while trading fur and other goods. Designation as a National Park was first proposed in 1891, and Voyageurs was officially established as a National Park in 1975. VNP covers 218,054 acres on the northern border of Minnesota, abutting BWCAW and sharing 55 miles of the Canadian border. 5

Minnesota has not had an approved Visibility Plan for its Class I areas, and has b een under a federal implementation plan for visibility as designa ted in 40 CFR 52.26, 52.28 and 52.29.

In accordance with the Regional Haze Rule, Minneso ta has determined that emission sources within Minnesota have or may have impacts both on the Class I areas within Minnesota (BWCAW and VNP) and on the Isle Royale Class I area in the state of Mi chigan. Therefore, Minnesota submits this SIP to fulfill the requirements of the Regional Haze Rule and help reduce visibility impairment in the Northern Class I areas mentioned above.

In addition, Minnesota believes that improved visibi lity and the removal of haze-causing particles from the atmosphere in order to promote increased visi bility in Class I areas will result in environmental and economic benefits and improved health for Minn esota’s citizens and those in areas downwind of Minnesota. Benefits of improved visi bility can be found in Appendix 1.1.

To facilitate the review of this State Implementa tion Plan (SIP) by the EPA, Federal Land Managers (FLMs), stakeholders and the public, Appendix 1.2 pr ovides a modified version of EPA’s SIP submittal checklist, which serves as a guide to locating 40 CFR 51.308 requirements.

4 BWCAW and U.S.D.A., Forest Service. Boundary Waters Ca noe Area Wilderness and Superior National Forest (web pages)

5 U.S. National Park Service, Voyageurs National Park (webpage)13 

### Chapter 2. General Planning Provisions

Pursuant to the requirements of 40 CFR 51.308(a) and (b ), Minnesota submits this SIP to comply with the Regional Haze Rule, adopted to meet the requirements set forth in the Clean Air Act. Elements of this plan address the core requirements pursuant to 40 CFR 51.308(d) and the Best Available Retrofit Technology (BART) components of 40 CFR 51.308( e). In addition, this SIP addresses Regional Planning, state and FLM coordination, and contains a commitment to provide ongoing plan revisions and adequacy determinations.

The Minnesota Pollution Control Agen cy (MPCA) has the legal authority to adopt this SIP revision and has done so in accordance with state laws and rules. MPCA’s legal authority and compliance with state procedures is documented through a letter from the Mi nnesota Attorney General’s office, attached as Appendix 2.1.

Minnesota provided multiple opportunities for stakehol ders to comment on the technical background and other issues regarding the development of this SIP, bo th informally and through the formal public notice and comment period. The following table lists non-mandatory stakeholder meetings held by the MPCA, along with the public meeting. Stakeholders were encouraged to comment informally throughout the SIP development process, and updates were posted on th e MPCA’s Minnesota Regional Haze Plan webpage. 6

Table 2.1: Stakeholder and Public Meetings
Date Subject and Content January 31, 2007 Review of Technical Information April 12 – April 27, 2007 Meetings with indi vidual stakeholder groups concerning long-term strategy (Northeast Minnesota Plan) May 15, 2007 Update of technical information Control Strategy Analysis Long-term Strategy October 23, 2007 Draft Regional Haze SIP is Information Item at MPCA Citizens’ Board April 10, 2008 Official public mee ting on Draft Regional Haze SIP. May 7, 2008 Stakeholder conference call on Draft Regional Haze SIP June 24, 2008 Final Initial Regional Haze SIP Information Item at MPCA Citizens’ Board September 22, 2009 Revised Draft Regional Haze SIP Information Item at MPCA Citizens’ Board October 27, 2009 Revised Draft Regional Haze SIP Decision Item at MPCA Citizens’ Board December 15, 2009 Continuation of Revised Draft Regional Haze SIP Decision Item at MPCA Citizens’ Board

A public notice of the opportunity to comment on the SIP was published on February 25, 2008 in the Minnesota State Register and contained notice of a pub lic meeting to be held on April 10, 2008, with the comment period to close on April 16, 2008. The comment period was later extended to May 16, 2008.

6 Addresses for all web pages referenced in this docu ment can be found the in “References and Guidance Documents” section.14 During the initial public notice period, the draft SI P document was made available on the MPCA’s Regional Haze webpage. In addition, a copy was ma de available at MPCA’s Headquarters, 520 Lafayette Road N., Saint Paul, Minnesota and at MPCA’s regional office in Duluth.

Copies of the initial public notice and the notice of exte nsion are attached in Appendix 2.2. A notice of the SIP revision and public comment period was also emailed to the MPCA’s list of stakeholders interested in regional haze and placed on MPCA ’s public notice and Regional Haze web pages. Minnesota held an official public meeting regarding the SIP revision on April 10, 2008; the meeting was based in St. Paul with videoconferencing to Duluth. Documentation of the public meeting is included in Appendix 2.3.

Public comments made during the notice period and at the public meeting are included in Appendix 2.4. MPCA’s response to the comments is also prov ided, which describes how MPCA considered and incorporated public comments into this final SIP document.

The MPCA’s response to comments, along with Minnesota’s proposed removal from the Clean Air Interstate Rule, necessitated several changes to the SI P. The MPCA communicated with the stakeholders, including the Federal Land Managers , who had made the most extensive comments on the initial draft SIP. These stakeholders made some interim comment s, and requested that the MPCA place the SIP back on public notice. The interim comments are included in Appendix 2.5, along with the MPCA’s response, and were included in the public notice of the re vised SIP. The second public notice is included in Appendix 2.2. Comments received on the revised SIP and the MPCA’s response are included in Appendix 2.6.15 

### Chapter 3. Regional Planni ng and State Consultation

Because regional haze is caused by a wide variety of pollution sources dispersed over a large geographic area, the Regional Haze Rule places specific emphasis on having states work collaboratively through regional planning and consultation processes.

Regional Planning In 1999, EPA and affected states/tribes agreed to cr eate five RPOs to facilitate interagency coordination on Regional Haze implementation plans. Minnesota is a member of the Central Regional Air Planning Association (CENRAP). MPCA has also worked ex tensively with the Lake Michigan Air Directors Consortium/Midwest Regional Pla nning Organization (LADCO/MRPO), 7 because several states in MRPO have emissions that impact Minnesota’s Class I areas and Minnesota has emissions that impact a Class I area located in Michigan.

Members of CENRAP include the states of Arkansas, Iowa, Kansas, Louisiana, Minnesota, Missouri, Nebraska, Oklahoma, and Texas; Tribes whose lands are within the geographical borders of these states are also members. Figure 3.1 shows a map of all five regional planning organizations.
Figure 3.1: Geographical Areas of Regional Planning Organizations

The governing body of CENRAP is the Policy Oversight Group (POG). The POG is made up of 18 voting members representing the states and tribes w ithin the CENRAP region and non-voting members representing local agencies, EPA, the Fish and Wildli fe Service, Forest Service, and National Park Service. The POG facilitates communication with Federal Land Managers (FLMs), stakeholders, the public, and with CENRAP staff.

Since its inception, CENRAP has established an active committee structure to address both technical and non-technical issues related to regional haze. This includes five standing workgroups: Data Analysis and

7 LADCO was formed to provide air quality technical assessments and assistance for Illinois, Indiana, Michigan, Ohio and Wisconsin; MRPO was formed to coordinate Regional Haze planning for thos e same states. LADCO was designated to receive federa l funds on behalf of MRPO.16 Monitoring; Emission Inventory; Modeling; Co mmunications; and Implementation and Control Strategies. Participation in workgroups is open to all interested parties. Ad hoc workgroups may be formed by the POG to address specific issues. Ultimately, policy decisions are made by the POG.

Consultation Across RPOs CENRAP has adopted the approach that the RHR re quires the “states to establish goals and emission reduction strategies for improving visibility in all 156 mandatory Class I parks and wilderness areas,” and has provided a forum and structure for states to work together to achieve these goals.

Minnesota also believes that the RHR encourages states and tribes to work together in regional partnerships beyond the RPOs when necessary, to ensu re that each Class I host state consults with all those states whose emissions impact its Class I areas.

Technical Consultation Minnesota participated in extensive consultation on technical work, both with CENRAP and MRPO. Like CENRAP, MRPO decisions and directions are es tablished by the Air Directors from each state and are carried out by the technical workgroups. Althou gh Minnesota does not actively participate in MRPO decision-making or communication processes, Minnesota staff members have actively participated in MRPO technical committees.

CENRAP has an administrative director and a technical director. The technical committees are run by cochairs, which are staff volunteers from CENRAP affiliated states and Tribes, or representatives from industry with interests within the geographic area. Nearly all CENRAP technical work is conducted through contracts; mainly by ENVIRON and University of California-Riverside.

MRPO has an administrative/technical director. The technical committees are run by MRPO staff. All technical work is coordinated by MRPO staff, and much of the technical work is conducted by MRPO staff with assistance from both member state staff and contractors. Table 3.1 lists the technical committee structure and Minnesota staff that actively partic ipated in each technical committee. Technical committees in both organizations incl ude representatives from states, EPA, FLMs, tribes and industry.

Table 3.1: Technical Committee Structure for CENRAP and MRPO, and Minnesota Participants

CENRAP: Administrative Directo r - Annette Sharp, Technical Director

– Jeff Peltola* Committee Leader (co-chair) Minnesota Participant Data Analysis and Monitoring Brandon Krogh* (Minnesota Power) Scott Weir (Kansas) Gordon Andersson gordon.andersson@pca.state.mn.us Emission Inventory Wendy Vit (Missouri) Michael Smith michael.smith@pca.state.mn.us Modeling Lee Warden (Oklahoma)* Calvin Ku (Missouri) Margaret McCourtney margaret.mccourtney @pca.state.mn.us Implementation and Control Strategies Mark McCorkle (Arkansas) John Seltz (Minnesota) John Seltz john.seltz@pca.state.mn.us MRPO: Administrative/Technical Directo r - Mike Koerbe r Committee Leade r Minnesota Participant Data Analysis and Monitoring Donna Kenski N/A Emission Inventory Mark Janssen Chun Yi Wu chunyi.wu@pca.state.mn.us Margaret McCourtney margaret.mccourtney @pca.state.mn.us Modeling Kirk Baker* Margaret McCourtney margaret.mccourtney @pca.state.mn.us *These leaders no longer hold the position, but had either significant or sole contribution to the work.17 Communication among technical committee members to develop consensus on various issues was conducted through conference calls and mee tings during SIP development as follows:

CENRAP calls and meetings:

• Data Analysis and Monitoring – Monthly conference calls;

• Emission Inventory – Calls on an as needed basis; no calls from May 2005 through May 2007. Met in joint conference call with modeling from June – September 2007;

• Modeling – Bi-weekly conference call.
Meetings are scheduled for all CENRAP participants and the POG two to four times per year as funding allows.

MRPO calls and meetings :

• Data Analysis and Monitoring – Not applicable . Minnesota is not an active participant;

• Emission Inventory – Monthly and/or as needed depending on needs for project input;

• Modeling – Monthly and/or as needed depending on needs for project input.
Meetings are scheduled separately for each technical committee, as new technical information is made available where sharing information is best done in person. The emissions inventory technical committee has exclusively shared information by conference call and e-mail. The modeling technical committee meets up to two times per year. Because of its centrally located staff, MRPO also communicates and provides data, tools and information individually to states based on specific needs.

This SIP mainly utilizes modeling inputs and results developed by MRPO, along with some MRPO data analysis and technical support work. It also includes modeling and data analysis generated by the MPCA. The SIP also includes data analysis and other t echnical support documents prepared for CENRAP, and CENRAP modeling work primarily as supporting information.

CENRAP data analyses, modeling results and othe r technical support documents were provided to CENRAP members through either CENRAP’s website or through a file transfer protocol (ftp). Similar information sharing was done using the LADCO webs ite and LADCO agreed to house documents related to the Northern Class I area consultation process on its website.

State Consultation A chief purpose of the RPO is to provide a means fo r states to confer on all aspects of regional haze, including consulting on reasonable progress goals and long-term strategies based on determinations of baseline and natural visibility conditions. CENRAP has provided a forum for the member states and Tribes to consult on the determination of visib ility conditions in each of the Class I areas.

Minnesota has worked with states that are members of CENRAP, MRPO, and the Western Regional Air Partnership (WRAP) to convene m eetings of representatives from th e states and Tribes that impact visibility in the four Northern Class I areas – BWCA W and VNP in Minnesota along with Isle Royale National Park and Seney Wilderness in Michigan – along with FLMs and EPA representatives involved with the Northern Class I areas. This group engaged in extensive consultation about visibility conditions and control strategies needed to improve visibility at these four Class I areas.

By coordinating with CENRAP, MRPO and the other states whose emissions impact visibility in our Class I areas, Minnesota has worked to ensure that our BART determin ations and the control strategies that comprise our long-term strategy provide suffici ent reductions to mitigate the impact of emissions from sources inside Minnesota on affected Class I are as, as well as to encourage other states to take necessary measures to help improve visibility in the Class I areas located within Minnesota.18 Northern Class I Area Consultation As described above, consultation among states is a requir ement of the Regional Haze Rule. As part of the long-term strategy for regional haze, a state whose em issions are “reasonably anticipated” to contribute to impairment in other states’ Class I area(s) must consult with those states; likewise, a Class I host state must consult with those states whose emissions affect its Class I area(s) (40 CFR 51.308(d)(3)). Because many states that impact visibility in BWCAW and VNP are located outside of CENRAP, the MPCA helped convene the Northern Class I area Consu ltation process to ensure that Minnesota met the requirement of consulting with all states whose emi ssions may impact visibility in our Class I areas.

Participants The Northern Class I areas consultation process conc erned visibility in BWCAW and VNP along with Isle Royale National Park and Seney Wilderness in Michigan, and included the states of Minnesota, Michigan, North Dakota, Wisconsin, Iowa, Illinois, I ndiana, and Missouri. The consultation process also included representatives from other governments, such as the Ontario Ministry of the Environment and Tribes including the Leech Lake Band of Ojibwe, M ille Lacs Band of Ojibwe, Fond du Lac Band of Lake Superior Chippewa, Grand Portage Band of Chippewa , Upper/Lower Sioux, and Huron Potawatomi.

The Northern Class I consultation process included representatives from federal agencies, including Federal Land Managers from the U.S. Department of the Interior National Park Service and U.S.D.A Forest Service, as well as representatives from EPA. Along with participation in CENRAP, this partially fulfills Minnesota’s requirement under 40 CFR 51.308 (i) to coordinate and consult with FLMs on areas such as implementation, assessment of visibility impairment, and recommendations regarding the reasonable progress goal and strategies for improveme nt. More specifics on Minnesota’s consultation with FLMs are treated in Chapter 4.

Process In 2004 and 2005, a number of discussions were held between state and tribal representatives in the upper Midwest concerning air quality planning to address regi onal haze in the four Class I areas in Michigan and Minnesota. This process included several conferen ce calls and a meeting in Madison, Wisconsin held on May 24, 2005.

Formal discussions geared toward specific SIP require ments began in July 2006, when Minnesota met in conference call with representatives from North Dakota, Iowa, Wisconsin, Michigan, the Mille Lacs and Leech Lake bands of Ojibwe, and FLMs, RPO and EPA representatives. This group determined that additional parties should be added to the process and that this group should continue to meet through conference calls approximately every three weeks dur ing the development of the regional haze SIPs.

The first several months of calls focused on develo ping an agreed-upon technical base of information about the visibility conditions in the four Class I area s. This included documenting baseline and naturalvisibility conditions, and determining the chemical constituents of haze and key contributors of visibilityimpairing emissions (geographical and sources and source categories). The shared technical work is documented in a technical memo “Regional Haze in the Upper Midwest: Summary of Technical Information,” which is attached as Appendix 3.1.

The consultation group also shared modeling results, discussed visibility improvement expected to result from on-the-books controls, and discussed BART and other control strategies. As part of the consultation process, LADCO managed a contract where various control strategies were evaluated based on the designated four factors; the consultation group provided input to LADCO on each part of the project. The control strategies that were evaluated included: on-the-books controls (as a reference point for19 reasonableness under the four factors), various sector level controls, and some facility specific control measures. (See Chapter 10 and Appendix 10.5).

The states involved in the consultation group also collabor ated to ensure that a consistent future year scenario was used by all states. Fo r example, the states agreed to use version 3.0 of EPA’s Integrated Planning Model (IPM) as the basic prediction for EGU emissions in 2018. Further information is provided in Chapters 8 and 10.

In September 2007 the MPCA sent a letter to the states involved in the Northern Class I areas consultation process. This letter cont ained formal notification of the states that Minnesota is listing in this SIP as causing or contributing to visibility impairment in VNP and BWCAW. It also contained information on Minnesota’s proposed process for se tting the Reasonable Progress Goals (RPG) for its Class I areas, and asked states and tribes to formally respond with an acknowledgement of their participation in the consultation process and their belief that the consultation process could be successfully concluded or an indication of what other issues should be discussed.

Although Minnesota had not yet set the RPGs for VNP and BWCAW when the consultation letter was sent out, the MPCA’s letter indicated that additiona l control measures (beyond on-the-books controls, BART, CAIR, and the Northeastern Minnesota plan) were likely to be reasonable for both Minnesota and the contributing states. Minnesota committed to eval uating additional control measures and including a plan for implementing reasonable controls in the Five Year SIP Assessment. The MPCA requested that the five contributing states (Illinois, Iowa, Missouri, North Dakota, and Wisconsin) make the same commitment. In particular, Minnesota asked Iowa, Mi ssouri, North Dakota and Wisconsin to evaluate the reasonableness of reductions of SO 2 from EGUs to reach a statewide rate of 0.25 lbs/MMBtu, and asked North Dakota to evaluate NO X emission reductions from EGUs.

In response, the Missouri DNR indicated that they do not believe they are significant contributors to visibility impairment in Minnesota’s Class I areas, and that evaluation of additional controls would not be reasonable. Iowa indicated that they cannot commit to controls beyond CAIR, and that the cost in $/ton of additional reductions is greater than the cost of complying with CAIR and therefore not cost-effective for visibility improvement. North Dakota provided on ly an informal response, but indicated that a lb/MMBtu comparison for EGUs is not reasonable, a nd that Minnesota should demonstrate that its EGUs have spent an equivalent amount (on a $/dv basis) as is being requested from out of state sources.

A copy of Minnesota’s letter (and the responses r eceived) can be found in Appendix 3.2. More information on the RPG and the state responses is in Ch apter 10. The MPCA continues to believe thatour request that the contributing states at least evaluate control measures beyond CAIR, BART and onthe-book controls, report on that evaluation in the Five Year SIP Assessment, and undertake reasonable additional controls, is a reasonable request. The MPCA requests that EPA take this into consideration when reviewing the SIPs of contributing states.

All documentation of the Northern Class I areas consultation process can be found on the LADCO/ MRPO website. 8 This webpage includes documentation of the minutes from each group conference call, including a list of participants, as well as various other documents related to the Northern Class I consultation process. These minutes and documents will show the major decisions that the members of the Northern Class I consultation process felt were impor tant to discuss and document at the group level.

8 MRPO, Regional Haze Consultation – Northern Class I areas

.20 

### Chapter 4. State and Federal Land Manager Coordination

Coordination between states and the Federal Land Managers (FLMs) is required by 40 CFR 51.308(i). Minnesota’s Class I areas are managed by the National Park Service (VNP) and the U.S. Forest Service (BWCAW). FLMs are an integral part of CENRAP’s POG and have membership on standing committees, and have therefore contributed to both the technical and non-technical work used in the development of this SIP. In addition, opportuniti es have been provided by CENRAP for FLMs to review and comment on each of the technical documents deve loped by CENRAP and included in this SIP. FLMs were also key participants in the Northern Class I consultation calls. Minnesota provided agency contacts to the FLMs as required by 40 CFR 51.308(i)(1).

Consultation During SIP Development In development of the SIP, the FLMs were consulted in accordance with the provisions of 40 CFR 51.308(i)(2). The MPCA provided FLMs an opportunity for consultation, in person and at least 60 days prior to holding any public hearing on the implementation plan.

The MPCA consulted with the FLMs to discuss the land managers’:

• Assessment of the impairment of visibility in any Class I areas;

• Recommendations on the development of reasonable progress goals; and

• Recommendations on the development and implem entation of strategies to address visibility impairment.

In addition to discussions on the SIP through the RPO framework, Minnesota and the other states involved in consultation about visibility in the four Northern Class I areas included FLMs in the ongoing discussions. FLMs were therefore able to give th eir comments about the technical work and control strategies under discussion by the states throughout th e period of regional haze SIP development, as well as the determination of the reasonable progress goals . The decisions made and documented in the Northern Class I calls (see Chapter 3) include d FLM input, as can be seen in the minutes and documentation of call participants.

The MPCA also extended invitations to several FLMs to participate in informal stakeholder meetings in January and May 2007, and several did take the opport unity to attend those meetings and hear about the MPCA’s haze SIP development.

The MPCA also consulted with the FLMs on BART and the BART strategy for Minnesota as published in the State Register (see Appendix 9.2). Cons ultation between the MPCA and the FLMs continued as BART analyses prepared by facilities were made av ailable online and the MPCA began the process of BART determinations.

The MPCA also had direct and extensive consulta tion with FLMs from the National Park Service and Forest Service in developing a strategy to addr ess visibility impairment resulting from emissions from new and existing sources in the geographic area of Minn esota in closest proximity to the Class I areas. MPCA staff members met in conference calls over the course of several months beginning in the spring of 2007 with a small group of FLMs involved w ith Minnesota’s Class I ar eas. The FLMs involved included: Bruce Polkowsky, Don Shepherd, John Bunyak, David Pohlman, and Chris Holbeck of the National Park Service and Trent Wickman of the Forest Service.

This consultation process resulted in the plan for Northeast Minnesota that is part of Minnesota’s longterm strategy for reducing regional haze (Chapter 10, Appendix 10.4), which will be implemented through this SIP and a Memorandum of Unders tanding between Minnesota and the federal land21 management agencies. The MPCA and the FLMs al so worked together to share the plan with stakeholders through the early summer of 2007.

MPCA provided the FLMs with early drafts of portions of this SIP submittal, particularly the portions concerning the RPG and long-term strategy. An informal draft of much of the SIP was provided to several of the FLMs mentioned previously during a face-to-face meeting between MPCA staff members and the FLMs at VNP on September 20 and 21, 2007, and em ailed at that time to the Regional Haze Coordinators for the Forest Service and Fish and Wildlife Service. The MPCA invited comments on the early draft SIP.

Official Notice and Consultation
MPCA sent the full draft SIP to the FLMs on Februa ry 4, 2008. Minnesota notified the FLMs of all stakeholder meetings, and the official p ublic meeting held on April 10, 2008.

Comments received from the FLMs are included in w ith the public comments in Appendix 2.4. Minnesota considered and incorporated the FLMs comments on the SIP draft as described in the Response to Comments documents, also in Appendix 2. 4. All FLM comments received prior to the public meeting were discussed, along with MPCA’s initial response, at the public meeting.

As the MPCA worked to respond to FLM comments, such as a request that BART determinations be made for EGUs, the MPCA continued to share info rmation with the FLMs. This included draft and revised BART determinations for Minnesota’s subject-to-BART EGUs. FLM comments on these BART determinations are included in Appendix 2.5, under the heading “Response to Interim Comments on Revised Regional Haze SIP.” These comments and th e MPCA’s response were included in the public notice period of the revised SIP.

Minnesota will continue to coordi nate and consult with the FLMs during the development of future progress reports and plan revisions, as well as during the implementation of programs having the potential to contribute to visibility impairment in the mandatory Class I areas.

The plan for Northeast Minnesota and the MPCA’s agreement with the FLMs specifically require consultation in order to ensure that the long-term strategy goals are being met.

The FLMs must continue to be c onsulted in the following instances:

• Development and review of im plementation plan revisions;

• Review of 5-year progress reports; and

• Development and implementation of other programs that may contribute to impairment of visibility in Class I areas.

Coordination and consultation will continue to occur, as needed, through CENRAP and the Northern Class I consultation process, and the MPCA will c ontinue to consult with the FLMs directly.22 

### Chapter 5. Assessment of Visibi lity Conditions in Class I areas

Baseline, Natural and Current Conditions The goal of the RHR is to restore natural visibilit y conditions to the 156 Class I areas identified in the 1977 Clean Air Act Amendments by mitigating all human -caused impairment of visibility. As stated in the rule, “natural conditions incl udes naturally occurring phenomena th at reduce visibility as measured in terms of light extinction, visual range, contrast, or coloration” (40 CFR 51.301( q)). Regional Haze SIPs must contain measures that make “reasonable progress” toward the natural visibility goal by reducing anthropogenic emissions that cause haze. For each Class I area, there are three visibility metrics that are part of determining reasonable progress:

• Baseline conditions

• Natural conditions

• Current conditions

Each of the three metrics includes the concentration data of the visibility pollutants as individual terms in the light extinction algorithm, with respective extincti on coefficients and relative humidity factors. Total light extinction when converted to deciviews (dv) is calculated for the average of the 20 percent best and 20 percent worst visibility days. Most information on visibility data, including calculations of conditions, is housed on the web through the Visibility Information Exchange Web System (VIEWS).

“Baseline” visibility is the starting point for the improve ment of visibility conditions. It is the average of the Interagency Monitoring of Protected Visual Environments (IMPROVE) monitoring data for 2000 through 2004 and can be thought of as “current” visibility conditions for this initial period. The comparison of initial baseline conditions to natu ral visibility conditions indicates the amount of improvement necessary to attain natural visibility by 2064. If states achieve visibility improvement at a constant rate over 60 years, visibility conditions will improve along the glide slope shown in Figure 5.1.
Figure 5.1: Uniform Rate of Progress (URP) to Achieve Natural Conditions in 60 Years

Natural visibility is determined by estimating the natu ral concentrations of visibility impacting pollutants and then calculating total light extinction with the lig ht extinction algorithm. Each state must estimate natural visibility levels for Class I areas within its bor ders in consultation with FLMs and other states (40 CFR 51.308(d)(2)). After the initial baseline ( 2000 – 2004) period, “current conditions” are to be assessed every five years as part of the SIP review where actual progress in reducing visibility impairment is compared to the goals set in the SIP.23 Default and refined values for natural visibility conditions EPA guidance provides states with a “default” estimate of natural visibility. 9 The default values of concentrations of visibility im pairing pollutants are based on a 1990 National Acid Precipitation Assessment Program report. 10 In the guidance, the United States is divided into “East” and “West” along the western boundary of the states one tier west of the Mississippi River. This divides the CENRAP states between the two areas: “East” which includes Arkansas (AR), Iowa (IA), Louisiana (LA), Minnesota (MN), and Missouri (MO) with seven Cl ass I areas, and “West” which includes Kansas (KS), Nebraska (NE), Oklahoma (OK), and Texas (TX) with three Class I areas.

In the guidance, EPA also provides that states may u se a “refined approach” to estimate the values that characterize the natural visibility conditions of the Cla ss I areas. The purpose of refinement would be to provide more accurate estimates with changes to th e extinction algorithm that may include concentration values; factors to calculate extinction from a measure d particular species and particle size; extinction coefficients for certain compounds; geographical variation (by altitude) of a fixed value; and/or the addition of visibility pollutants. States can choo se between the default and refined equations.

One equation is used to calculate baseline and cu rrent conditions of visibility due to haze-causing pollutants; using natural concentrations of the same pollutants, the same equation is used to calculate natural visibility.

The original (default) algorithm:

The new (refined) algorithm:

9 U.S. EPA, 2003a.

10 Trijonis, 1990. 

### 10 60 1 10 4 3 3

+ ×+ ×+ ×+ ×+ ××+ ××≈

]Mass Coarse[.

]l SoiFine[

]Carbon Elemental[ ]Carbon Organic[ ]Nitrate[f(RH) ]Sulfate[f(RH) b ext

)]ppb(NO[. )specificsite(Scattering Rayleigh ]Mass

Coarse[. ]SaltSea[(RH)f.

]SoilFine[ ]Carbon

Elemental[ ]Carbon OrganiceargL[.]Carbon Organic Small[. ]NitrateeargL[(RH)f.]Nitrate Small[RH)(f. ]SulfateeargL[(RH)f.]Sulfate Small[RH)(f.b

ss L s L s ext

2 330 60 71 1 10 16 82 15 42 84 22

×+ + ×+ ××+ ×+ ×+ ×+ ×+ ××+ ××+ ××+ ××≈24 The New (or refined) IMPROVE equation is nonlinear in sulfate (SO 4 ), nitrate (NO 3 ) and organic mass carbon (OMC) concentrations, accounting for the different light scattering efficiency characteristics as a function of concentrations for these three species. The total sulfate, nitrate and organic mass are each split into two fractions, representing small and large size distributions of those components. New terms have been added for Sea Salt (important for coastal areas) and for light absorption by NO 2 , where NO 2 observations are available. (These observations are not available for Minnesota, so this component was not used; it is also not included in the original IM PROVE equation.) Site-specific Rayleigh scattering for each IMPROVE monitoring site is used in the new equa tion, as compared to a constant value assumed in the original equation.

The choice between use of the default or the refined equation for calculating the visibility metrics for each Class I area is made by the state in which the Class I area is located. According to 40 CFR 51.308(d)(2), the state will make the determinations of baseline a nd natural visibility conditions. It is with these calculations and in consultation with other states whose emissions affect visibility in that Class I area (40 CFR 51.308(d)(1)(iv)) that the state develops a reasonable progress goal for each Class I area.

Because the refined equation better fits the observe d light extinction values, Minnesota has used the refined IMPROVE equation to calculate visibility metr ics and develop its reasona ble progress goals. This is consistent with the approach ta ken by surrounding states; the CENRAP states and those participating in the Northern Class I area consulta tion process have also elected to perform their primary visibility projections using the new IMPROVE equation. For comparison, calculations based on the old IMPROVE equation are shown in Appendix 5.3.

Using the refined equation, the MPCA has determined that natural visibility conditions for BWCAW are best represented by an average of 11.6 deciviews for most impaired days and 3.4 deciviews for the least impaired days. Natural visibility conditions for VNP are best represented by 12.2 deciviews for most impaired days and 4.3 deciviews for the least impaired days.

Consultation regarding the visibility metrics As mentioned previously, Minnesota consulted with the states that impact BWCAW and VNP on the visibility metrics in those Class I areas. The states discussed which equation to use to calculate the visibility conditions as well as which values to use fo r baseline and natural conditions, particularly due to some data substitution done on the monitored data, described later. This consultation process is documented in Chapter 3.

Baseline Visibility Conditions Baseline conditions represent visibility for the 20% best (B20%) and 20% worst (W20%) visibility days for the initial five-year baseline period of the regiona l haze program. Baseline conditions are calculated using IMPROVE monitor data collected during 2000-2004 and are the starting point in 2004 for the 2018 uniform rate of progress (URP) goal and 2018 visibility projections.

Baseline conditions were calculated as follows: 11

A. Using monitored data, rank base line visibility for each day with PM 10 , PM 2.5 and speciated PM 2.5 measurements within a Class I area.

1. Obtained PM 2.5 speciated monitored data from VIEWs with inclusion of missing data from MRPO;

11 U.S. EPA, OAQPS. 2007a.25 2. Estimate extinction coefficient for each day using the new IMPROVE equation 12 adopted by the IMPROVE Steering Committee in December 2005: 13

b ext = 2.2 * f S (RH) * [small sulfate] + 4.8 * f L (RH) * [large sulfate]
+ 2.4 * f S (RH) * [small nitrate] + 5.1 * f L (RH) * [large nitrate] + 2.8 * [small organic mass] + 6.1 * [large organic mass] + 10 * [elemental carbon] + 1 * [fine soil]
+ 1.7 * f SS (RH) * [sea salt] + 0.6 * [coarse mass] + Rayleigh scattering (site specific—BOWA1= 11, VOYA2 = 12) + 0.33 * [NO 2 (ppb)]

where:
b ext is calculated total light extin ction in inverse megameters f

S (RH) is the relative humidity adjustment factor for small particles; f

L (RH) is the relative humidity adjustment factor for large particles; f

SS (RH) is the relative humidity adjustment factor for sea salt; and The apportionment of the total concentration of su lfate compounds into the concentrations of the small and large size fractions is accomp lished using the following equations: [large sulfate] = ([total sulfate]/20μg/m3) * [total sulfate], for [total sulfate] < 20 μg/m3; [large sulfate] = [total sulfate], for [total sulfate] ≥ 20 μg/m3; and [small sulfate] = [total sulfate] – [large sulfate]
The same equations above for large sulfate, are also used to apportion total nitrate and total organic mass concentrations into the large and small size fractions.

NO 2 is not currently measured at the IMPROVE monitors in Minnesota, so this factor is not included. It also is not part of the “old” IMPROVE equation.
Table 5.1: Monthly fS(RH) and fL(RH) values 14,15

Class I f (RH) Jan Feb Mar Apr May Ju n Jul Aug Sep Oct Nov Dec

BOWA1 f S (RH) 3.24 2.84 2.99 2. 64 2.93 3.21 3.44 3.67 3.80 3.07 3.50 3.49

f L (RH) 2.50 2.26 2.32 2.09 2.22 2.42 2.57 2.69 2.76 2.37 2.65 2.65

f SS (RH) 3.74 3.37 3.34 2. 92 3.03 3.43 3.68 3.85 3.95 3.44 3.89 3.92

VOYA2 f S (RH) 3.16 2.77 2.82 2. 59 2.65 3.28 3.25 3.48 3.66 3.02 3.37 3.32

f L (RH) 2.46 2.22 2.22 2.07 2.09 2.46 2.46 2.59 2.70 2.35 2.58 2.55

f SS (RH) 3.69 3.31 3.20 2. 90 2.89 3.46 3.55 3.71 3.87 3.42 3.83 3.80

12 IMPROVE Steering Committee, January 2006.

13 VIEWS Website, Regional Haze Rule Planning Documents.

14 VIEWS Website.

15 Hand and Malm, March 2006.26 3. Convert b ext to decivews (dv) using the following equation:
Haze Index (dv) = 10 ln (b ext /10)

Where: b ext and light scattering due to Rayleigh scatte ring (i.e. the “10” in the denominator) are both expressed in inverse megameters (Mm -1 ). In order to be consistent across all Class I areas, the U.S. EPA prescribed that the Rayleigh Scattering in the denominator of the conversion of the extinc tion value to deciviews should always be 10 instead of using site-specific Rayleigh Scattering values. 16

4. Order the deciview values for all days at each Cl ass I area for each of the 5-years of the baseline period from worst (highest deciview value) to best (lowest deciview value).
B. Calculate the average baseline deciview for the 20 percent worst (highest deciview values) and for the best (lowest deciview value).

1. Calculate the arithmetic mean deciview value for the 20 percent worst and best visibility values for each year;

2. Average the resulting 5-year mean deciview values reflecting worst visibility for each of the years; and

3. Average the 5-year mean deciview values reflec ting best visibility for each of the years.

BWCAW has a baseline visibility of 6.4 deciviews fo r the cleanest 20 percent of the sample days and 19.9 deciviews for the 20 percent worst visibility days . The average visibility for all days across the baseline period is 12.3 deciviews. This is base d on sampling data collected at the BWCAW IMPROVE monitoring site (BOWA1). A five year average ( 2000 to 2004) was calculated for each value (both best and worst) in accordance w ith 40 CFR 51.308(d)(2).

Note that the air monitors at BOWA1 had a long-term malfunction from 2002 through 2004, which resulted in missing monitoring data for certain chemical species. Data for sulfate and nitrate, the main contributors to visibility impairment, were valid for these days, but data for other species was missing. Data for BWCAW has therefore been “patched” for th e invalid chemical species by using data from the VNP IMPROVE monitor (VOYA2) adjusted based on th e usual relationship between the concentrations of those chemical species between the two monitors when both captured valid data (determined through a regression analysis).

VNP area has baseline visibility of 7.1 deciviews for the cleanest 20 percent of the sample days and 19.5 deciviews for the 20 percent worst visibility days. Th e average visibility for all days across the baseline period is 12.6 deciviews. This is based on sampli ng data collected at the VOYA2 IMPROVE monitoring site. A five year average (2000 to 2004) was ca lculated for each value (both best and worst) in accordance with 40 CFR 51.308(d)(2).

For all four Northern Class I areas, and others ar ound the country, several cases arise where days were excluded from the calculation of light extinction because some measured components were missing 17 and therefore the data did not meet EPA’s gui delines for visibility monitoring data. 18 The most frequently missing components were coarse mass and soil; howev er, these two species account for a very small fraction of light extinction in the Northern Class I areas and, despite the missing components on these

16 U.S. EPA, OAQPS, 2007a.

17 Donna Kenski of the Midwest RPO brought this issue to the attention of the Northern Class I consultation group and did extensive data analysis on this issue.

18 U.S. EPA, 2003b.27 days, the light extinction from the sum of the measured species exceeds the 80 th percentile. Additional information on this issue is included in Appendix 5.2.

Including these days in the baseline calculations has a small but measurable effect on the average deciviews for the 20% worst days. Minnesota has decided to include these days in our baseline calculations, even though the guidance calls for them to be excluded, because they appear to be largely dominated by anthropogenic sulfate and nitrate source s. Because these are the types of poor visibility days that need to be targeted by re gional haze control strategies they were retained in order to assure that they receive adequate scrutiny.

Natural Visibility Conditions Minnesota relied on natural visibility conditions cal culated with the new IMPROVE algorithm by the VIEWS staff. Errors in the original calculations of natural conditions, impacti ng sites at high altitude and sites with substituted data (suc h as BWCAW) were found, and Minnesota used corrected natural conditions distributed by email from the Cooperative Institute for Research in th e Atmosphere (CIRA) in August 2007. 19 MPCA understands that these data will be posted on the VIEWS website, but they are not yet available. Nonetheless, Minnesota has relied on these data as we believe they offer the best picture of the natural conditions. The calculation method for natu ral conditions is provided in “Calculation Method for Natural Conditions with the New IMPROVE algorith m,” presented to the Air and Waste Management Association specialty conference “Aerosol and Atmosphe ric Optics: Visual Air Quality and Radiation” in Moab, Utah, April 28, 2008 through May 2, 2008.

Table 5.2, below, gives a summary of the visibility metrics for Minnesota’s Class I areas; these metrics include all substituted data and the re-inclusion of the dropped days as described above. The baseline and natural condition values in Table 5.2 are those used by the MPCA in developing this SIP and the RPG for Minnesota’s Class I areas.
Table 5.2: Visibility Metrics for Minnesota’s Class I areas 20

Natural Background Conditions 21

Class I area Average for 20% Worst Days (dv) Natural Conditions for 20% Best Days (dv) Average for 20% Worst Days B ext (Mm -1 ) Average for 20% Best Days B ext (Mm -1 )
BWCAW 11.6 3.4 33 14
VNP 12.1 4.3 35 15
Baseline Visibility Conditions 2000-2004

Class I area Average for 20% Worst Days (dv) Average for 20% Best Days (dv) Average for 20% Worst Days B ext (Mm -1 ) Average for 20% Best Days B ext (Mm -1 )
BWCAW 19.9 6.4 76.0 19.2

VNP 19.5 7.1 72.5 20.5

19 Copeland, 2007. (Email)

20 This table shows the official visibility conditions used by the MPCA in developing this SIP. It includes all substituted data for BWCAW and the re-inclusion of all sample days that were previously dropped. Note that some days that were previously dropped did not include measurements for all components, therefore B ext cannot be calculated for those days. The B ext values in the table, then, are an averag e of only those in the 20% best or worst where light extinction can be calculated.

21 Natural background conditions were not recalculated with the inclusion of th e previously dropped days, due to the time necessary to do these calculations and the belief that the resulting change would be very small.28 Table 5.3 shows the yearly visibility metrics for all four Northern Class I areas , with the same algorithm and data adjustments as made for Table 5.2. Table 5.3 calculates the URP for all four Northern Class I areas with the adjusted data.

Table 5.3: Adjusted Visibility Metri cs in dv for Northern Class I areas

2000 2001 2002 2003 2004 Baseline (Average) Natural Conditions

BWCAW 20% Worst 20.2 20.2 20. 8 20.1 18.2 19.9 11.6
20% Best 6.0 6.9 6.9 6.5 5.8 6.4 3.4

VNP 20% Worst 19.6 18.6 20. 1 20.3 18.9 19.5 12.1
20% Best 7.0 7.0 7.5 7.6 6.3 7.1 4.3

Isle Royale 20% Worst 20.5 23.1 22. 0 22.3 20.0 21.6 12.5
20% Best 6.5 7.1 7.0 7.1 6.1 6.8 3.7

Seney 20% Worst 22.9 25.9 25. 4 24.5 23.2 24.4 12.8
20% Best 6.6 6.8 7.8 8.0 6.6 7.2 3.7
As this table shows, visibility conditions in Minnesota ’s Class I areas have been relatively consistent over the baseline period. Preliminary indications are that this trend has continued. Although not used in calculating the baseline, in 2005 the average conditio ns at BWCAW for the 20% worst days was 21.3 dv and for the 20% best days was 6.3 dv. For VNP, it a ppears that the average co ndition for 20% worst days in 2005 was 20.3 dv and for the 20% best days the average conditions were 6.8 dv.

Table 5.4 lays out the URP that would result in Minn esota’s Class I areas meeting natural conditions by 2064 and shows the deciview improvement needed to meet natural conditions for both best and worst 20% days and to meet the URP glide path for 20% worst days in 2018.

Table 5.4: Northern Class I a reas URP in dv; Adjusted Data

Annual

URP (W20%) 2018 URP Goal (W20%) Improvement from Baseline URP Requires by 2018 (W20%) Improvement from Baseline to Meet Natural Conditions

(W20%) Improvement from Baseline to Meet Natural Conditions (B20%) BWCAW 0.14 17.9 2.0 8.3 3.0

VNP 0.12 17.8 1.7 7.3 2.8 Isle Royale 0.15 19.5 2.1 9.1 3.1

Seney 0.19 21.7 2.7 11.6 3.5

Figures 5.2 and 5.3 graphically show the URP for VNP and BWCAW, respectively. Baseline conditions shown include the visibility conditions for each individual year of the baseline period, designated with the smaller points; the URP line is drawn from the aver age over the baseline period for both best and worst days. The graphs also visually show both the im provement that would be needed to meet natural conditions on the 20% best days as well as the requirement for no degradation on the 20% best days.29 Figure 5.2: Uniform Rate of Progress for BWCAW

Figure 5.3: Uniform Rate of Progress for VNP 0.0 5.0 10.0 15.0 20.0 25.0

1990 2000 2010 2020 2030 2040 2050 2060 2070

YearDeciviews Baseline Conditions 20% Worst Days

Baseline Conditions

20% Best Days Natural Conditions 20% Worst Days

No Degradation on

20% Best Days

Natural Conditions

20% Best Days 2018 URP: 17.9

0 5 10 15 20 25

1990 2000 2010 2020 2030 2040 2050 2060 2070

YearDeciviews Baseline Conditions 20% Worst Days

Baseline Conditions

20% Best Days 2018 URP: 17.8

Natural Conditions 20% Best Days No Degradation on

20% Best Days Natural Conditions 20% Worst Days30 Updated Visibility Conditions Since 2004, additional data on visibilit y conditions in the Class I areas ha s become available. Table 5.5, below, shows visibility conditions from 2005 through 2007 at the Class I areas impacted by Minnesota (BWCAW, VNP, and Isle Royale). Data from 2005 through 2007 was taken from the VIEWS Regional Haze Rule dataset, posted on the VIEWS webpage. The baseline conditions fro m 2000 through 2004, an average since 2000, and natural c onditions are included for reference. 22

Table 5.5: Visibility Conditions 2005 - 2007

22 Note that the 2005 through 2007 data has not been adjusted. The data has not been checked for days were excluded from the calculation of light extinction because some measured components were missing but where the light extinction from measured species exceeds the 80 th percentile. Therefore, data may not be directly comparable to the 2000 – 2004 average, but should still provide a snaps hot of visibility trends in the Class I areas impacted by Minnesota. Site Days 2005 2006 2007 Baseline (Average 2000 - 2004) 2000 - 2007 Average Most Recent Five Year Average (2003 - 2007) Natural Conditions
BWCAW 20% Worst 21.3 19.6 19. 8 19.9 20.0 19.8 11.6
20% Best 6.3 5.8. 5.8 6.4 6.3 6.1 3.4

VNP 20% Worst 19.9 20.5 19. 2 19.5 19.6 19.8 12.1
20% Best 6.8 6.5 6.7 7.1 6.9 6.8 4.3
Isle Royale 20% Worst 23.8 21.9 21. 7 21.6 21.9 21.9 12.5

20% Best 7.1 6.4 6.4 6.8 6.7 6.6 3.731 

### Chapter 6. Monitoring Strategy

Part 40 CFR 51.308(d)(4) of the federal Regional Haze Rule requires a monitoring strategy for measuring, characterizing, and repor ting regional haze visibility impairment that is representative of all mandatory Class I areas within Mi nnesota. The monitoring strategy relies upon participation in the IMPROVE network.

Minnesota’s participation in the IMPROVE monito ring network largely meets the requirements of subsections (i) and (iv). The IMPROV E network began in 1988 with 42 sites at or near Class I areas. At the time of promulgation of the Regional Haze Rule in 1999, there were 80 monito rs. In 2000 and 2001, an additional 30 sites were added to Class I areas, and 34 to non-Class I areas. (IMPROVE monitors operated outside of Class I areas are “Protocol” monitors, operated for FLMs, states , and tribes). Another 18 IMPROVE Protocol monitors were added in 2002, 13 of which went into CENRAP state and Tribal lands. Today there are 110 Class I area IMPROVE monitors and 52 non-Class I area (IMPROVE Protocol) monitors in the country.

In the language of subsection (i), these additional mon itors were established in order to measure visibility pollutants in areas outside of national parks and w ilderness areas, to understand the concentrations, sources and transport of regional haze that affects th e Class I areas. Subject to continued EPA funding, these same monitors will be used to assess progr ess in attaining the reasonable progress goals in subsequent SIP reviews and revisions.

Current Monitoring Strategy Upon the creation of CENRAP, the Monitoring Workgr oup identified large visibility data voids for Southern Arkansas, Iowa, Kansas, Southern Minnesota, Nebraska, and Oklahoma. Only five IMPROVE sites were located in the CENRAP region. Betw een 2000 and 2003, five more IMPROVE sites and 15 IMPROVE Protocol Sites were installed.

In Minnesota, IMPROVE sites are located in the two Class I areas, at BWCAW (monitor BOWA1) and VNP (monitor VOYA2). IMPROVE Protocol sites are located in the southern areas of the state, in Blue Mounds and Great River Bluffs. Minnesota commits to meeting the requirements under 40 CFR 51.308(d)(4)(iv) to report to EPA visibility data for each of Minnesota’s Class I areas annually.

The filter samples from the IMPROVE modules are sent for analysis to the Crocker Nuclear Laboratory of the University of California in Davis and the anal ysis data is posted to th e IMPROVE website and the VIEWS website. This fulfills Mi nnesota’s requirement for electroni c reporting of visibility data under subsection (iv).32 Figure 6.1 CENRAP IMPROVE and IMPROVE Protocol Sites

In addition to the four IMPROVE sites, Minnesota also has several monitoring stations for fine and coarse particulate matter located across the state, which can be used to gather additional information about the concentrations, sources, and transport of particulate matter. For fine particulate matter, the MPCA has three monitoring networks: Federal Reference Me thod (FRM), continuous, and speciation networks. There are currently 29 PM 2.5 sites in Minnesota operating as part of one of these networks. The speciation network, used to gather data on the species compos ition of fine particulate matter, includes the four IMPROVE monitors and two additional Speciation Tr ends Network (STN) site s operated by the MPCA, in Minneapolis and Rochester. 23

The location of these monitors, for those active as of January 2008, is shown in the tables below:

Table 6.1: Active Minnesota PM 2.5 Monitoring Sites

Site Name City County Dlth Lincoln Park Sch Duluth St. Louis WDSE Duluth St. Louis 37W/I35 Duluth St. Louis Virginia Virginia St. Louis Ely Fall Lake Lake
Detroit Lakes Detroit Becker Brainerd Airport Oak Lawn Crow Wing
Fond Du Lac Cloquet Carlton
Mille Lacs Kathio Mille Lacs St. Cloud Talahi Sch St. Cloud Stearns St. Michael School St. Michael Wright Anoka Airport Blaine Anoka

23 MPCA, 2008.33 Site Name City County Wenonah School Minneapolis Hennepin MSP Airport Fort Snelling Hennepin Putnam School Minneapolis Hennepin Phillips Minneapolis Hennepin
Richfield Richfield Hennepin NE Fire Station Minneapolis Hennepin Humboldt Minneapolis Hennepin St. Louis Park St. Louis Park Hennepin Harding HS St. Paul Ramsey St. Paul Hlth Dept St. Paul Ramsey
Red Rock Road St. Paul Ramsey Apple Valley Apple Valley Dakota Shakopee Shakopee Scott Marshall Airport Fairview Lyon ROCHESTER Rochester Olmsted

Table 6.2: Active Minnesota PM 10 Monitoring Sites

Site Name City County Dlth Lincoln Park Sch Duluth St. Louis WDSE Duluth St. Louis 37W/I35 Duluth St. Louis Virginia Virginia St. Louis DM&IR Cemetery Two Harbors Lake
Mille Lacs Kathio Mille Lacs St. Cloud Talahi Sch St. Cloud Stearns St. Michael School St. Michael Wright St. Paul Park 3 St. Paul Park Washington Mpls downtown Minneapolis Hennepin Humboldt Minneapolis Hennepin St. Louis Park St. Louis Park Hennepin Harding HS St. Paul Ramsey St. Paul Hlth Dept St. Paul Ramsey
Red Rock Road St. Paul Ramsey Ross Av/St Paul Fire St. Paul Ramsey Vandalia St. Paul Ramsey Apple Valley Apple Valley Dakota
Wicker Rosemount Dakota MPCA Rosemount Dakota ROCHESTER Rochester Olmsted

Future Monitoring Strategy In order to assess progress in reducing visibility impa irment in Class I areas, the existing IMPROVE and IMPROVE Protocol sites should be maintained. Oper ation is contingent upon continued federal funding to measure, characterize and report regional haze visibility impairment.

The MPCA believes that maintenance of the IMPROVE monitoring network is critical to the long-term success of the Regional Haze program. In the event of a complete loss of federal funding, the MPCA will attempt to provide support for the operation of at least one of the two IMPROVE sites.34 Should the IMPROVE monitoring network be disba nded, Minnesota could use information from other PM 2.5 monitoring sites to make some estimates of PM 2.5 concentrations, and thus visibility impairment, in the Class I areas. Minnesota evaluates the monito ring network periodically, including evaluation of technology changes and the need for new monitors. More information about the monitoring networks in place in Minnesota, and any future planned changes, can be found in the Annual Air Monitoring Network Plan for the State of Minnesota. 24 Further details regarding Minnesota’s ambient air monitors (location, date of installation etc.) and monitoring data can also be found online through the MPCA’s Environmental Data Access System. 25

Special Monitoring Studies As funding permits, CENRAP, in cooperation with stat es and tribes, intends to study the impact of ammonia and carbon on visibility impairment in the CENRAP region. Preliminary monitoring studies and monitoring data analysis suggests that these two air constituents contribute to a large portion of visibility impairment in the CENRAP geographical area.

24 MPCA, 2008.

25 MPCA, Environmental Data Access System - Air Quality Data . (webpage)35 

### Chapter 7. Emission Inventory

40 CFR 51.308(d)(4)(v) requires a statewide emission inventory of pollutants that are reasonably anticipated to cause or contribute to visibility impairme nt in any mandatory Class I area. As specified in the applicable EPA guidance, the pollutants inve ntoried by Minnesota include volatile organic compounds (VOC), nitrogen oxides (NO X ), fine particulate (PM 2.5 ), coarse particulate (PM 10 ), ammonia (NH 3 ), and sulfur dioxide (SO 2 ).

Minnesota rules require point sources to submit reports of their emissions to the MPCA each year, and an annual point source emission inventory is produced . Minnesota compiles a full statewide emission inventory every three years, and submits this data to the National Emission Inventory (NEI). Minnesota will continue to update the full emission inventory on this three-year cycle.

State Inventory – 2002 The MPCA’s most recent complete statewide emission inventory is from 2002. A summary of the inventory results is shown below in Table 7.1.
Table 7.1: Minnesota 2002 Baseline Emissions Inventory Summary (tpy) 26

VOC NO X SO 2 PM 10 PM 2.5 NH 3 Point Sources 29,000 150,000 130,000 31,000 13,000 1,300 Area Sources 160,000 57,000 17,000 730,000 150,000 170,000 Mobile Sources On-Road 91,000 170,000 3,000 3,800 2,800 5,400 Non-Road 84,000 100,000 9,100 9,700 8,900 97 TOTAL 366,000 485,000 160,000 779,000 169,000 179,000

Because the 2002 emission inventory is critical as a baseline for comparing future emissions and application of control strategies, MPCA felt it was important to understand if 2002 was a representative year, or if the emissions tended to be high or low when compared to other recent years. If 2002 emissions were high, for example, future year emissions might show decreases that might be wrongly attributed to the implementation of control strategies.

In order to gain a more complete understanding of the 2002 inventory, MPCA staff compared point source emissions in the 2002 inventory to point sour ce emissions from surrounding years. In general, although there is certainly some variation, the 2002 inventory was found to be largely representative of annual emissions from large point sources, particularly for the key haze causing pollutants of SO 2 and NO X . 27

MPCA’s emission inventory staff has recently comp leted compiling the 2005 emission inventory.

26 The emission inventory is presented to two significant digits. Totals might not add due to rounding.

27 Information on Minnesota’s emission inventory is av ailable in the air quality section of the MPCA’s Environmental Data Access system.36 The 2005 inventory figures are shown in the table below.
Table 7.2: Minnesota 2005 Emissions Summary (tpy)

VOC NO X SO 2 PM 10 PM 2.5 NH 3 Point Sources 26,000 150,000 130,000 30,000 13,000 2,000 Area Sources 130,000 34,000 17,000 740,000 140,000 170,000 Mobile Sources On-Road 93,000 140,000 2,600 3,500 2,400 5,700 Non-Road 96,000 100,000 9,600 8,400 8,000 64 TOTAL 349,000 422,000 159,000 778,000 166,000 180,000

Inventory Methodology The MPCA EI staff compiled the 2002 Minnesota Po int Source Inventory using acceptable, established methodologies, which are ranked by preference. This hierarchy of methodologies and use are required by Minnesota’s Air Emission Inventory Rule, Minn. R. 7019.3000, for facilities submitting an air emission inventory. All air permit holders are required to submit an annual air emission inventory.

The following are the accepted methodologies in order of preference:

1) Continuous Emission Monitor (CEM) Data 2) Performance Test Data 3) Volatile Organic Compound (VOC) or Sulfur Dioxide (SO 2 ) Mass Balance 4) Emission Factors – EPA published generic factors from documents such as AP-42 or FIRE database.

Methodologies that can reflect site and process specific data are always preferable to a default, generic emission factor. AP-42 emission factors represent averaged emission factors for the entire industry or type of equipment. Appendix 7.1 contains a dditional information on how Minnesota compiles its emissions inventory.

Modeling Inventory Although the statewide inventory forms the basis of the emissions that are input into the atmospheric chemistry and transport models that ultimately predict visibility conditions , substantial work is needed to process the emissions for modeling purposes. Therefor e, the specifics of the emissions used in the modeling work, known as the modeling i nventory, are detailed in Chapter 8.37 

### Chapter 8. Modeling

The Regional Haze rule requires states to “establish goals (expressed in deciviews) that provide for reasonable progress toward achieving natural visibilit y conditions for each Class I area within a state,” improving visibility on the most impaired days and not degrading visibility on the least impaired days. 28 The core of the visibility assessment – the baseline and natural conditions base d on observed data – is fully described in Chapter 5.

The baseline conditions are developed from five years of monitoring data, and represent the starting point from which reasonable progress is measured. The Regional Haze Rule prescribes the baseline period as the years 2000-2004, and defines baseline visibility conditions as the average of the most visibility impaired days (the 20 percent worst days), and the av erage of the least visibility impaired days (the 20 percent best days) calculated from the monitoring data for each year of the baseline, and then averaged over the 5-year baseline period. 29 The ultimate goal is to reach natu ral visibility conditi ons in 2064, and reasonable progress goals are interim goals representing progress toward that end. The year 2018 is the initial year for developing a reasonable progress goal.

Models are used to establish a reasonable progr ess goal (RPG) by simulating the future visibility conditions that will result from fu ture emission estimates. A set of EPA developed guidelines 30 outline the methodology for modeling future conditions and applying modele d results to develop reasonable progress goals.

Emissions from a “base,” or known, year (i.e. 2002) representing the baseline period and from a year in the future (i.e. 2018) are each modeled. The mode l results are used to estimate the air concentration change from base year to future year. These air c oncentration changes are in the form of ratios of the future year air concentrations to the base year concentrations predicted near a monitor location and averaged over the same 20 percent worst and 20 percen t best days in the base year that were used to establish baseline visibility conditions. A ra tio is developed for each specie comprising PM 2.5 (sulfate, nitrate, organic carbon, elemental carbon, fine soil [ ≤ 2.5 μm diameter], and coarse particulate matter [ > 2.5 μm, but ≤ 10 μm diameter]). The ratio is called a Rela tive Response Factor (RRF), calculated as follows:

RRF [SO4] = Modeled Future Mean [SO4] /Modeled Base Year Mean [SO4]

Where: RRF is the relative response factor (unitless);

Future Mean and Base Year Mean are the m odeled base year (2002) and the future year (2018) concentrations at the Class I area m onitor location averaged for the 20 percent worst days (and 20 percent best days) as determined by the base year (2002) monitor data; and
The same equation above for sulfate is also used for nitrate, organic carbon, elemental carbon, fine soil and coarse particulate matter.

28 40 CFR 51.308(d)(1).

29 40 CFR 51.308(d)(2).

30 U.S.EPA, OAQPS, 2007a38 Applying the RRFs to baseline monitoring conditions, for each species comprising PM 2.5 

### , provides the estimate of future visibility conditions (described below):

• Multiply each species specific RRF, develope d from the 2002 and 2018 modeling data, by the corresponding measured species concentration fo r all of the 20 percent worst (and 20 percent best) days over the 5-year baseline period. (example for sulfate below);

[SO 4 ]future = RRF (SO4) * [SO 4 ]baseline (daily value)

• Estimate extinction coefficient for each of th e 20 percent worst (and 20 percent best) days using the IMPROVE equation (detailed in Chapter 5, Baseline Visibility Conditions, calculations, Section A.2.), and convert to deciviews (detailed in Chapter 5, Baseline Visibility Conditions, calculations, section A.3); and

• Calculate the average future year deciview for the 20 percent worst (and 20 percent best) days. 1. Calculate the arithmetic mean deciview va lue for the 20 percent worst and best visibility values for each year in the baseline period; and 2. Average the resulting 5-year mean deciview values (for the 20 percent worst, and for the 20 percent best).

Recognizing the intense resources re quired to conduct modeling analyses of this nature, EPA guidelines for regional haze do not suggest modeling the multiple years comprising the 5-year baseline period, but discuss modeling one full year as a “logical goal”. The methodology in the EPA guidelines attempts to take into account the year-to-year variability of the meteorology in the monitored baseline. The middle year (2002) will have more weight due to the fact th at the 2002 emissions and meteorology are used in the modeling to develop the RRF applied to the baseline c onditions. This application of the model results is intended to balance the resource limitations of conduc ting multiple years of modeling, and to “help reduce the impact of possible over-or under-estimations by th e dispersion model due to emissions, meteorology, or general selection of othe r model input parameters”.

The resource requirements for conducting regional s cale modeling make it necessary to consolidate resources and develop the modeling analyses through the RPO process. Regional haze modeling at BWCAW and VNP was performed by CENRAP, MRPO and by Minnesota; MRPO conducted modeling using both a 2002 base year and 2005 base year. Minnesota supplemented the RPO modeling by focusing on the two Minnesota Class I areas and the visibility impacts of nearby point sources located within Minnesota. Minnesota’s modeling uses MRPO-developed emissions and meteorological data inputs from the 2002 base year and 2018 future year, with some modifications, and is referred to throughout this chapter as the Minnesota (MRPO) case.

The reasonable progress goals for BWCAW and VNP are set using the Minnesota (MRPO) case; however, the other analyses are valuable for assessing uncer tainty in the modeling analysis and helping to determine whether the model likely overpredicts, und erpredicts, or accurately predicts the reasonable progress goal associated with the long-term strategy. As part of the weight-of-evidence supporting the Minnesota RPG, the end of this chapter contains a summary of differences in the modeling results by CENRAP, MRPO (2002) and MRPO (2005) as compared to the Minnesota (MRPO) case.

The modeling described herein supports the policy decisi ons made in this Regional Haze SIP. Details on the modeling analyses conducted are in a separa te document titled “Minnesota Technical Support Document for the Regional Haze State Implementation Plan” (TSD). This document is available at39 http://www.pca.state.mn.us/publications/rhsip-tsd.pdf. The sections below summarize the methods and inputs used for the regional modeling.

The Modeling System The modeling system is composed of an atmospheric transport and chemistry model, also known as the “air quality model,” an emissions model and a meteor ological model. The emissions and meteorology models create inputs for use by the air quality model.

One of the criteria considered when choosing a sy stem was its ability to allow Minnesota to conduct modeling to assess visibility impacts from Minnesota sources near the Class I area, as this type of modeling falls outside the scope of RPO modeling work, which focuses on the larger, more regional visibility impacts. The MRPO supports contributing states in conducting modeling and uses an air quality model whose resource requirements are reasonable for Minnesota. For this reason, Minnesota chose to use the modeling system chosen by MRPO. The modeling system 31

, 32 is made up of the following:

• Air Quality Model: Comprehensive Air Quality Model (CAMx). CAMx simulates atmospheric and surface processes affecting the transport, chemical transformation and deposition of air pollutants and their precursors. Some advantages of CAMx are two-way nesting, which “allows CAMx to be run with coarse grid spacing over a wide regional domain in which high spatial resolution is not particularly needed, while with in the same run, applying fine grid nests in specific areas where high resolution is needed”, 33 a subgrid scale plume-in-grid module to treat the early dispersion and chemistry of point sour ce plumes, a fast chemistry solver increasing processing speed allowing overall timely model results, and Particulate Source Apportionment Technology (PSAT) that tracks the original sour ce of particulate species by geographic region and source category. CAMx is an Eulerian model that computes a numerical solution on a fixed grid. Minnesota used CAMx version 4.42.

• Meteorological Model: The Pennsylvania State University/National Center for Atmospheric Research (PSU/NCAR) Mesoscale Meteorological Model (MM5). The MM5 model simulates mesoscale and regional scale atmospheric circulation. 34 MM5 output data is used in the emissions model and in the air quality model.

• Emissions Model: Emissions Modeling System (EMS-2003). EMS-2003 generates hourly speciated emissions on a gridded basis for mobile , nonroad, area, point, natural (biogenic) and fires. The emissions are input to an air quality model.

Model Year Chosen Regional haze issues appear throughout the year in th e Minnesota Class I areas, which made it necessary to model a full year rather than a shorter episode period. A model year must coincide with a year scheduled for emissions inventory development. As noted in Chapter 7, states develop full emissions inventories every three years, the most recent be ing the fully completed 2002 inventory. The 2005 inventory was still in development during the SIP m odeling process. EPA guidance suggests choosing a model year that has monitoring data available that straddles the model year. Minnesota has selected 2002 as the base year for modeling.

31 The MRPO conducted modeling for a 2005 base year analysis using CAMx version 4.50, a combination of EMS2003 and Concept (for mobile source), and MM5 run by Alpine Geophysics.

32 CENRAP chose the Community Multiscale Air Quality M odel (CMAQ) as its air quality model, the Sparse Matrix Operator Kernel Emissions (SMOKE) model as its emissions model, and MM5 as its meteorological model.

33 ENVIRON, 2006.

34 MM5 Community Model Homepage.40 During the iterative process of regional scale modelin g, MRPO decided to switch to a 2005 base year. Although Minnesota still uses MRPO inputs in its Minnesota (MRPO) model analyses, they remain the 2002 base year, with some adjustments. The 2002 base year allows Minnesota to better correlate results with CENRAP, which also uses 2002 as its base year, and a llows for using monitoring data that straddles the inventory year (2000-2004) to establish baseline conditions. The state of Iowa developed the meteorological data inputs for the 2002 base year. 35

Conceptual Description As described above, visibility is a year-round issue in the upper Midwest Class I areas. Observed values indicate that the 20 percent worst days are spread acr oss all months of the year except February in 2002 (see Appendix 5.2). During the warmer months several days are influenced by wildfires, 36 which can contribute large amounts of organic carbon that significantly affect extinction. Wildfire emissions are uncontrollable. Natural (biogenic) emissions are anot her uncontrollable source that impact visibility, i.e. volatile organic compounds (VOC) from trees that form secondary organic aerosols.

Throughout the year, but especially in the warmer m onths, the controllable emissions of sulfur dioxide (SO 2 ) and nitrogen oxides (NO X ) have the most impact on visibility at BWCAW and VNP. These emissions are controllable because their release results from human activities. SO 2 emissions impact visibility year-round, while NO X emissions contribute the most impact on visibility in the colder months. This happens because nitrate formation occurs in the colder months, as in the warmer months NO X will remain in the gas phase as nitric acid. Ammonia preferentially reacts with SO 2 , so nitrate forms only when there is enough ammonia left over after fo rming ammonium sulfate by reacting with SO 2 . While particulate sulfate can form whether there is ammoni a present or not, particulate nitrate needs ammonia to form.

Ammonia is released primarily from animal farms throughout the year, peaking in the warmer months, and additionally from agricultural practices in the Spri ng and Fall. Ammonia is critical to formation of ammonium sulfate and ammonium nitrate, the main controllable species contributing to visibility issues in the Class I areas. Ammonium nitrate and ammonium sulfate need time to form in the atmosphere and are understood to travel large distances

Modeling/Analysis Protocol A protocol details and formalizes the procedures for conducting all phases of the modeling study, including the methodology (grid projections, domains, meteorological inputs, emissions inputs, the configuration of the model), the evaluation of m odel performance against observed data, and how the visibility analysis will be conducted. Minnesota did not prepare its own regional modeling protocol, relying instead on the meteorological and air quality modeling protocols prepared by the MRPO. Minnesota explored answers to questions specific to Minnesota beyond the scope covered by the air quality modeling protocol prepared by the MRPO. For example, Minnesota is interested in the visibility impact of sources located near BWCAW and VNP. This resulted in a modeling analysis using a 12km nested grid and a plume-in-grid tool for individual el evated point sources located within a certain distance of the Class I areas. Plume-in-grid tracks individual plume segments from each point source, rather than immediately dispersing the individual point sources emi ssions into the grid cell. Therefore, it can treat the early dispersion and chemistry of point source plumes. In order to use the plume-in-grid module properly, some modifications to the air quality mode ling input files were required. For example, stack parameter and location information has greater impor tance when plume-in-grid is employed. The TSD provides the protocol for implementing featur es not covered in the MRPO protocol.

35 Both Minnesota (MRPO) and CENRAP used the same meteorological data inputs developed by the state of Iowa for 2002.

36 MRPO, 2007b.41 Emissions Preparations & Results
Emissions were combined into sectors based on the similarity of the techniques used to process the emissions. Sectors are:

• Point or industrial sources that are identified by lo cational coordinate and stack parameters (i.e. facilities with state permits);

• Mobile Onroad or automobile and truck traffic on paved roadways;

• Nonroad or mobile equipment not traveling on roadwa ys (i.e. recreational vehicles, construction and agricultural equipment);

• Marine vessels, airplanes and locomotives (also considered “nonr oad” sources although techniques vary);

• Area or stationary sources that are not identified by locational coordinate and stack parameters (e.g. agricultural processes like fertilizer use a nd livestock operations, residential heating); and

• Biogenic or natural emissions (i.e. trees are an important biological emissions source).

Emissions modeled for regional haze are sulfur dioxide (SO 2 ), nitrogen oxides (NO
x ), Volatile Organic Compounds (VOC), ammonia (NH 3 ), fine particulate (PM 2.5 ) and coarse particulate mass.

The Base Year Inventory – 2002 For the most part, base year inventories are develope d by each individual state. These are essentially the same inventories states submit to the EPA for the Nati onal Emissions Inventory (NEI). For some sectors, methods initially available to states for inventory de velopment were inadequate for air quality modeling. For these sectors, the RPOs have independently, an d in some cases cooperatively, hired contractors to develop emissions data to support improvement of state

- developed inventories where the other methodology, insufficient for modeling purposes, was used. For example, it is important to have accurate ammonia emissions because ammonia combines with sulfuric and nitric acid to form aerosol sulfate and nitrate, significant components of PM 2.5 and of visibility impairment. Also, states do not create inventories for biogenic sources, so these inventor ies had to be created for modeling purposes.

Although an inter-RPO technical consultation mechan ism was in place, the timing of individual RPO inventory improvements results in some variation in the emissions characterization of a state among the RPO in which it is a member, and other RPOs. Minnesota worked closely with both CENRAP and MRPO to ensure Minnesota’s sources were characteri zed as accurately and with as much scrutiny as possible; the two RPOs independently developed a modeling inventory for Minnesota. In the TSD, Minnesota summarizes overall differe nces between the CENRAP and MR PO inventories and how these differences might impact the model results.

The Future Year Inventory – 2018 The Economic Growth Analysis System (EGAS) model was used to estimate the growth of emissions from 2002 to 2018 for all source categories, except on -road mobile sources and EGUs. EGAS is a forecast model based on the premise that growth in em issions largely depends on the growth in economic activity, particularly changes in sales forecasts, in an area. On-road mobile sources were grown with MOBILE6. EGU emissions were grown using the Integr ated Planning Model (IPM). IPM predicts future EGU emissions assuming an energy balance throughout electricity supply grids.

The RPOs agreed to use IPM to predict future EGU emissions during the technical consultation process. The consulting firm ICF Internationa l developed the IPM model, which EP A uses to evaluate the future impact of policies and regulations, in combination wi th projected energy needs, on EGUs. For example, EPA used IPM to develop the Clean Air Interstate Rule (CAIR). The IPM model output presumes CAIR is implemented. The modeling that supports Minne sota’s reasonable progress goals incorporated IPM version 3.0.42 The MPCA believes IPM 3.0 predictions for Minne sota in 2018 are much improved over previous versions of IPM simulations. Other RPOs, such as CENRAP, use an earlier IPM version 2.1.9(VISTAS). 37 Upon review of the IPM 3.0 predictions, MPCA staff found some adjustments to the output were necessary to reflect staff knowledge of Minnesota EGUs and future projections, but many more adjustments would be needed to IPM 2.1.9(VI STAS). Both versions of IPM presume CAIR is implemented, but they make different assumptions in other areas, such as fuel cost estimates.

The MRPO modified the IPM 3.0 future year estimate s with information submitted by its member states plus Minnesota, North Dakota, Iowa and Missouri. For example, Minnesota made a correction to the emissions for Minnesota Power-Boswell to account for an underestimation of th e facility’s capacity in IPM. Further adjustments were limited to committed control projects that occurred after the deadline for submission of such projects to EPA for inclusion in IPM 3.0. All corrections and adjustments made to Minnesota EGUs were done in c onsultation with industry representatives. Table 8.1 summarizes Minnesota’s adjustments and corrections to IPM 3.0.
Table 8.1: Minnesota Adjustments and Corrections to IPM Version 3.0

Facility Name Basis for Correction/Adjust ment Unit # IPM base Total Emissions (Mton) IPM “will do” Total Emissions (Mton) NO x SO 2 NO x SO 2 Minnesota Power-Boswell Unit 3 adjusted to reflect NO X permit limit, SO 2 decreased with addition of Fabric Filter/Flue Gas Desulfurization
Unit 4 capacity increased from 425 MW to 535 MW 3

4 0.79

3.75 6.11

4.00 0.93

4.72 1.19

3.22
Xcel - A.S. King Adjusted based on per mit limit. 1 1.43 1.87 2.08 2.49 Xcel - Black Dog Adjusted upward based on current performance in response to Xcel Energy comments. 3 4 1.17 1.63 3.92 5.47

Minnesota Power-Taconite Harbor Furnace Sorbent Injection on Units 1 through 3. 1 2 3 1.56 1.39 1.37 0.67 0.68 0.67

The combination of IPM 3.0 with these modifications results in a scenario called IPM 3.0 “will do.” Table 8.2, prepared by MRPO, shows the overall difference in emissions among IPM 2.1.9(VISTAS), IPM 3.0, and IPM 3.0“will do” scenarios for each state in the upper Midwest.

Concerns have been raised as to whether adju sting IPM output compromises the integrity of the predictions. IPM assumes an energy balance throughout the EGU sector, and the concern is that modifications at a handful of facilities can throw the system off-balance. However, Minnesota views IPM as one method for predicting future EGU emissions and if states and affected industry believe that the predicted emissions are incorrect, they should change th em in order to get the most accurate estimate of future emissions in the state. The corrections a nd adjustments made by Minnesota should not throw the system off-balance, as they generally address only ch anges in the performance of equipment, resulting in emission changes, and not overall energy balance.

VISTAS states have also made post-IPM model adju stments for their states to the IPM 2.1.9(VISTAS) output. CENRAP has not made adjustments to the IPM 2.1.9(VISTAS) output used in their modeling.

37 This IPM version is called IPM2.1.9(VISTAS) because the VISTAS RPO coordinated an IPM run based on EPA’s IPM version 2.1.9; but with CENRAP, MRPO and VISTAS member state modifications to the IPM input parameters related to committed (i.e. permitted) control proj ects at various EGUs that were not covered by the initial IPM version 2.1.9 run by EPA.43 CENRAP intended to switch to IPM 3.0, but did not due to timing and financial reasons. The Minnesota (MRPO) modeling was able to easily include the re vised IPM 3.0 EGU emissions in the future year inventory because, unlike other sectors, EGU emission projections with IPM are calculated independent of the base year inventory.

Table 8.2: IPM2.1.9 (VISTAS), and IPM3.0 “base” and “will do” Alterations

State Heat Input (MMBtu/year) Scenario SO 2 (tons/year) SO 2 (lb/MMBtu) NO X (tons/year) NO X (lb/MMBtu)

IL 980,197,198 2001 - 03 (average) 362,417 0.74 173,296 0.35 IPM 2.1.9 (VISTAS) 241,000 73,000 1,310,188,544 IPM3.0 (base) 277,337 0.423 70,378 0.107 IPM3.0 - will do 140,296 0.214 62,990 0.096

IN 1,266,957,401 2001 - 03 (average) 793,067 1.25 285,848 0.45 IPM 2.1.9 (VISTAS) 377,000 95,000 1,509,616,931 IPM3.0 (base) 361,835 0.479 90,913 0.120 IPM3.0 - will do 628,286 0.832 128,625 0.170

IA 390,791,671 2001 - 03 (average) 131,080 0.67 77,935 0.40 IPM 2.1.9 (VISTAS) 147,000 51,000 534,824,314 IPM3.0 (base) 115,938 0.434 59,994 0.224 IPM3.0 - will do 115,938 0.434 59,994 0.224

MI 756,148,700 2001 - 03 (average) 346,959 0.92 132,995 0.35 IPM 2.1.9 (VISTAS) 399,000 100,000 1,009,140,047 IPM3.0 (base) 244,151 0.484 79,962 0.158 IPM3.0 - will do 244,151 0.484 79,962 0.158

MN 401,344,495 2001 - 03 (average) 101,605 0.50 85,955 0.42 IPM 2.1.9 (VISTAS) 86,000 42,000 447,645,758 IPM3.0 (base) 61,739 0.276 41,550 0.186 IPM3.0 - will do 54,315 0.243 49,488 0.221

MO 759,902,542 2001 - 03 (average) 241,375 0.63 143,116 0.37 IPM 2.1.9 (VISTAS) 281,000 78,000 893,454,905 IPM3.0 (base) 243,684 0.545 72,950 0.163 IPM3.0 - will do 237,600 0.532 72,950 0.163

ND 339,952,821 2001 - 03 (average) 145,096 0.85 76,788 0.45 IPM 2.1.9 (VISTAS) 109,000 72,000 342,685,501 IPM3.0 (base) 41,149 0.240 44,164 0.258 IPM3.0 - will do 56,175 0.328 58,850 0.343

SD 39,768,357 2001 - 03 (average) 12,545 0.63 15,852 0.80 IPM 2.1.9 (VISTAS) 12,000 15,000 44,856,223 IPM3.0 (base) 4,464 0.199 2,548 0.114 IPM3.0 - will do 4,464 0.199 2,548 0.114

WI 495,475,007 2001 - 03 (average) 191,137 0.77 90,703 0.36 IPM 2.1.9 (VISTAS) 155,000 46,000 675,863,447 IPM3.0 (base) 127,930 0.379 56,526 0.167 IPM3.0 - will do 150,340 0.445 55,019 0.16344 Minnesota Growth Changes in Minnesota(MRPO) 2018 Modeling Inventory Minnesota removed the EGAS estimated growth from taconite facilities in Northeast Minnesota and replaced it with MPCA generated growth estimates. The Minnesota (MRPO) 2018 inventory growth consists of three new taconite facilities in Northeast Minne sota; Mesabi Nugget, and a proposed “east mine” and “west mine” that reflect emissions projections fo r Polymet Mining and Minnesota Steel Industries. Emission units that did not operate in 2002 (and so we re not in the 2018 inventory) were also added at two existing plants: United Taconite (Line 1), a nd Northshore Mining Silver Bay (Furnace 5). These emissions are present only in the Minnesota (MRPO) modeling.

Controls on Future Year Inventory Control factors that reduce emissions are applied after growth and may be due to the addition of physical controls to a process. These controls may be volunta ry or due to regulatory requirements. Controls also reflect federal and state regulations , legislation and permit actions. MR PO contracted with E.H. Pechan and Associates to identify controls to be implem ented – termed “on-the-books” controls – between 2002 and 2018 in source sectors except EGUs. In the MRPO inventory, the controls on all sectors (including EGUs) are:

On-Highway Mobile Sources

• Tier II/Low sulfur fuel;

• Inspection/Maintenance programs in nonattainment areas (does not apply in Minnesota); and

• Reformulated gasoline in nonattainment areas (does not apply in Minnesota).

Off-Highway Mobile

• Federal control programs incorporated into NONR OAD model (e.g. nonroad diesel rule), and the evaporative Large Spark Ignition and Recreational Vehicle standards;

• Heavy-duty diesel (2007) engine standard/Low sulfur fuel;

• Federal railroad/locomotive standards; and

• Federal commercial marine vessel engine standards.

Electric Generating Units 38

• Title IV Acid Rain Program (Phases I and II);

• NO X SIP Call (does not apply in Minnesota);

• Clean Air Interstate Rule.

Other Point Sources

• VOC 2-, 4-, 7-, and 10-year Maximum Achievab le Control Technology (MACT) standards;

• Combustion turbine MACT; and

• Industrial boiler/process heater/RICE MACT.

• The MRPO also included control factors to reflect settlement agreements for petroleum refineries and other non-EGU sources in MRPO states plus Minnesota. 39

The Minnesota (MRPO) 2018 inventory includes the MRPO listed cont rols on the future year inventory.

Minnesota emissions totals for 2002 and 2018 from the Minnesota (MRPO) inventory are shown in Table 8.3. Emissions totals for states surrounding Minnesota are provided in the TSD.

38 These controls are included in the IPM3.0 projections.

39 MACTEC, 2006.45 Table 8.3: Annual Minnesota 2002 and 2018 Emissions Totals in Tons 40

2002 Source Group SO 2 NO X NH 3 PM 25 PM 10 VOC
Point 131,000 155,000 2,310 12,500 31,100 33,700
Area 22,800 58,100 175,000 19,500 72,200 133,000

Mobile On-road 29 172,000 7,200 2,200 2,200 97,600
Non-road 9,210 102,000 98 5,600 6,380 96,800 Biogenics 0 28,700 0 0 0 698,000
Minnesota TOTAL: 163,000 516,000 185,000 39,900 112,000 1,060,000

2018 Source Group SO 2 NO X NH 3 PM 25 PM 10 VOC
Point 83,500 117,000 3,420 25,100 47,900 42,800
Area 22,700 62,100 239,000 19,500 72,400 129,000

Mobile On-road 2 31,400 10,100 514 514 20,000
Non-road 2,170 76,900 125 4,410 5,030 86,700 Biogenics 0 28,700 0 0 0 698,000
Minnesota TOTAL: 108,000 317,000 253,000 49,600 126,000 977,000

Alternative EGU Emission Projections without CAIR. As described above, the on-the-books controls for EGUs presume CAIR is in effect. In July 2008, after the end of the initial public notice period for this SIP, the D.C Circuit Court of Appeals issued an opinion pointing out several “fatal flaws” with CAIR, and vacated the rule. The EPA petitioned for rehearing which included changing the remedy from vacatur to a remand. On December 23, 2008, the Court remanded CAIR to the EPA to be rewritten to address th e flaws identified in the July ruling. This action means that CAIR is in effect while the flaws are addressed.

One issue the EPA must address on remand is whethe r Minnesota should continue to be included in CAIR. The Court ruled in July that the EPA did no t adequately respond to claims made by Minnesota Power that data on Minnesota emissions were inaccura te, and that by using bett er data Minnesota would fall below the threshold impact on a nonattain ment area that was used for inclusion.

In a letter dated October 31, 2008, from the EPA to Minnesota Power counsel, the EPA indicated its intent “to publish in the Federal Register a rule amen ding CAIR to stay the effectiveness of the rule with respect to sources located in the State of Minnesota. That administrative stay will remain in effect until such time as EPA determines through a rulemaking u nder the Clean Air Act whether Minnesota should be included in the CAIR region for fine particulate matter . EPA believes that in light of the Court’s decision, sources in Minnesota should not be required to make any additional e xpenditures to comply with CAIR prior to the expiration of the administrative stay of the rule.” 41 A proposed rule to stay application of CAIR in Minnesota was published on May 12, 2009. 42

At the time CAIR was vacated by the courts, the MR PO developed future year EGU emissions without CAIR in place. Rather than use the IPM model, which was used to model CAIR, the emissions withoutCAIR were developed using electric ity generation forecasts from the Department of Energy’s Electricity Market Module Supply Regions by fuel type, and then applying known controls. Details on how the future year projections were estimated are in the TSD.

40 To three significant digits. Totals may not add due to rounding.

41 Meyers and Nakayama, 2008.

42 74 FR 2214746 Minnesota has determined that the known controls in 2018 with CAIR in place – as modeled in the IPM 3.0 “will do” scenario and used to establish the RP G – and without CAIR in place – as shown in the MRPO Case B 2018 – are nearly identical for Minnesota. The resulting emissions projections are also very similar. Dissimilarities in emissions projections are attributed to differences in emission projection methods. The control assumptions in the IPM 3.0 “will do” scenario (with CAIR in place) and the controls without CAIR are shown in Table 8.4.

Because of the similarities in EGU emissions project ed in Minnesota, both with and without CAIR, the MPCA has continued to use the modeling includ ing the IPM 3.0 “will do” projections for EGUs.
Table 8.4: Future Year Control Assumptions with and without CAIR

Facility Name Facility ID Stack ID Emission Unit ID Pollu -tant Controls Without CAIR Controls With CAIR Case B: Legally

Enforceable Modeled in SIP (IPM v3.0"will do") 2018 Control EF Control Type 2018 Control EF Control Type*

Xcel Energy -

Riverside Generating Plant 2705300015 SV001 EU001 NO X 100% removed 100% removed SO 2 100% removed 100% removed

EU002 NO X 100% removed 100% removed SO 2 100% removed 100% removed

SV003 EU003 NO X 100% removed 100% removed SO 2 100% removed 100% removed

EU009 NO X * new unit natural gas * new unit natural gas

SO 2 * new unit natural gas * new unit natural gas

SV008 EU010 NO X * new unit natural gas * new unit natural gas

SO 2 * new unit natural gas * new unit natural gas

SV009 EU011 NO X 100% removed 100% removed SO 2 100% removed 100% removed Minnesota Power Inc -

Boswell Energy Ctr 2706100004 SV003 EU003 NO X 80% SCR 80% SCR

SO2 85% FGD 85% FGD

Rochester Public Utilities - Silver Lake 2710900011 SV003 EU004 NO X 40% SNCR ** **

SO 2 85% SCRUBBER 95% SCRUBBER

Xcel Energy -

High Bridge Generating 2712300012 SV001 EU001 NO X 100% removed 100% removed SO 2 100% removed 100% removed

EU002 NO X 100% removed 100% removed SO 2 100% removed 100% removed

EU003 NO X 100% removed 100% removed SO 2 100% removed 100% removed

EU004 NO X 100% removed 100% removed SO 2 100% removed 100% removed

SV008 EU010 NO X * new unit natural gas * new unit natural gas

SO 2 * new unit natural gas * new unit natural gas

SV009 EU011 NO X * new unit natural gas * new unit natural gas

SO 2 * new unit natural gas * new unit natural gas47 Facility Name Facility ID Stack ID Emission Unit ID Pollu -tant Controls Without CAIR Controls With CAIR Case B: Legally

Enforceable Modeled in SIP (IPM v3.0"will do") 2018 Control EF Control Type 2018 Control EF Control Type*

Xcel Energy -

Sherburne Generating Plant 2714100004 SV001 EU001 NO X 50% LNB ** ** SO 2 85% SCRUBBER  

EU002 NO X 50% LNB **  ** SO 2 85% SCRUBBER   SV002 EU003 NO X 50% LNB **  ** Xcel Energy - Allen S King Generating 2716300005 SV001 EU001 NO X 80% SCR 90% SCR

SO 2 82% SCRUBBER 82% SCRUBBER

Minnesota Power Inc -

Taconite Harbor Ctr 2703100001 SV001 EU001 NO X 50% ROFA/SNCR 50% ROFA/SNCR SO 2 40% FSI 40% FSI

SV002 EU002 NO X 50% ROFA/SNCR 50% ROFA/SNCR SO 2 40% FSI 40% FSI

SV003 EU003 NO X 50% ROFA/SNCR 50% ROFA/SNCR SO 2 40% FSI 40% FSI

Northshore Mining Silver Bay 2707500003 SV001 EU001 NO X 40% LNB SO 2 20%*** Biomass

SV002 EU002 NO X 40% LNB SO 2 20%*** Biomass * Additional emissions for new units in the without-CAIR case were projected to be comparable to the IPM 3.0 projections ** These projects became legally enforceable after the IPM 3.0 “will do” case was developed. ***This control, which is part of the BART determination for the unit, was not included in the final “Controls without CAIR” because the BART determination was incomplete at that time.

Biomass: Co-firing biomass with existing fuel FGD: Fabric Filter/Flue Gas Desulfurization FSI: Furnace Sorb ent Injection LNB: Low NOx Burner ROFA: Rotating Opposed Fire Air System SCR: Selective Catalytic Reduction SNCR: Selective Non-Catalytic Reduction

MRPO Quality Assurance for Emissions Inventories While developing the emissions inventory and conducti ng emissions modeling, Minnesota participated in the MRPO quality assurance for emissions inventorie s. The MRPO assured the quality of the data through the review of emissions reports and spatial analysis. 43

• Emission Reports : EMS performs a number of checks and generates several re ports, as documented in the EMS User’s Guide. 44 The quality assurance checks for point sources, for example, include checks for missing or mislocated location data, missing or invalid state and county designation codes, missing facility name, missing or invalid Standard Industry Classification codes, and missing or outof-range stack parameters. The reports include tabul ar summaries of the state- and county-level emissions for point, area, and mobile sources ; and various spatial plots of emissions.

• Spatial Analysis : A second level of quality assurance is pe rformed by the air quality modelers. The additional checks include evaluating sp atial tile plots of total daily SO 2 , NO X , VOC, ammonia, PM 2.5 ,

43 Baker, 2004.

44 LADCO, 1999a.48 and coarse mass emissions, and evaluating plots that show the variation in emissions from month to month, and from hour to hour.

Canada Emissions Inventory In addition to including emissions from the indivi dual states within the United States, CENRAP and MRPO included emissions from Canada in an attemp t to accurately characterize the 2002 base year. Canada’s provinces report an emissi ons inventory to Environment Canada , similar to the states reporting the NEI to the EPA. The Criteria Air Contaminants Emission Inventory, a s ubset of Canada’s overall Pollutant Release and Transfer Register (P RTR), includes the relevant pollutants.

However, Canada does not report emissions on the sa me schedule as the U.S., and a 2002 inventory was not available for use by the RPOs. The Canadian in ventory is confidential and specifics are not shared freely outside the country. This makes it difficult to quality assure the data and understand whether the estimation methods are comparable. The MRPO has been collaborating with environmental staff in Ontario to better understand and implement improvement s to the emissions estimates in that province.

For their base year 2002 inventories, CENRAP and MRPO used the Canadian 2000 inventory. During the iterative modeling process, it was determined th at much of the emissions in the 2000 Canada inventory were assigned no stack height and as a result were modeled with the emissions released in the surface layer of the atmosphere. These included some very large sources, whose emissions are, in reality, released at much higher elevations. Because of me teorological (i.e. wind direction and speed) differences throughout the various layers, revisions to the rel ease height were required. CENRAP made these changes to the Canadian 2000 inventory based on 2 005 data. MRPO, which was in the process of switching to a 2005 base year, chose to use the Canadi an 2005 inventory, and with the help of Ontario environmental staff fixed the problems there. The Minnesota (MRPO) case replaces the 2000 Canada inventory with the Canada 2005 inve ntory. Because of the large uncer tainties in the Canada inventory, Minnesota elected to use the Canada 2005 inventor y for both the base year and future year.

CENRAP used stack information from the Canada 2005 inventory to modify the Canada 2000 inventory, and used a Canada projected inventory from 2000 to 2018. The 2018 Canada inventory was distributed by the EPA and it is not clear whether EPA corrected the stack parameter problems with the 2018 Canada inventory.

Air Quality/Meteorology Preparations and Results Emissions and meteorology were generated for ever y hour and allocated to 36km grids over the National Inter-RPO Domain. This domain was agreed upon by all the RPOs as the basic domain from which to model. The MRPO uses a subset of the national RPO domain, called the 4rpos domain, to focus on an area that includes the United States and Canada east of a line dissecting the United States at the westernmost tip of Texas.

Both the National Inter-RPO Domain and the MRPO 4rpos domain are shown in Figure 8.1. CENRAP generated modeling emissions in a similar fashion, but encompassing the entire National Inter-RPO 36km domain. In addition to using the MRPO domain, Minnesota created a 12km flexi-nested domain and used the CAMx plume-in-grid tool to evaluate visi bility impacts of individual elevated point sources located near the Class I areas.49 Figure 8.1: Modeling Domains

Performance Evaluation for Air Quality Models

Meteorological Model Performance for the Base Year ( 

### 2002) Data The meteorological data was prepared by Matthew Johns on of the state of Iowa. There are two model performance documents: Meteorological Modeling Performance Summary for Application to PM 2.5

/Haze/Ozone Modeling Projects 45 and Meteorological Model Performance Evaluation of an Annual 2002 MM5 (version 3.6.3) Simulation v2.0.3

. 46 Model performance was deemed good.

Air Quality Model Performance for the Base Year (2002) Inventory Both CENRAP and MRPO have evaluated model perfo rmance over the entire domains they modeled. Because Minnesota is using MRPO inputs with emis sions modifications, the state focused its own model performance on BWCAW and VNP. Particular atten tion was placed on the 20 percent best and worst days in the two Class I areas.

Model performance evaluation is conducted on the base year, 2002, using the 2002 emission inventory (except for Canada) and meteorology. Several iterations of the 2002 base inventory were completed by MRPO, culminating in the final 2002 inventory that serves as the basis for the Minnesota (MRPO) modeling. Model performance evaluations of these iterations a llowed for improving the emissions, meteorology and the CAMx model, resulting in improved model performance. The base year period used to evaluate model performance is the same as the base y ear used in the modeled attainment test.

Minnesota evaluated performance of the model specif ically at BWCAW and VNP; and for the 20 percent worst days. The speciated components used in the Minnesota (MRPO) evaluation are collected at IMPROVE monitor network sites. This network collects individual PM 2.5 components at BWCAW and VNP.

45 Baker et al., 2005.

46 Johnson, 2004 – 2007. National Inter-RPO 36km Domain

MRPO "4rpos" 36km Domain

Minnesota 12km Nested Domain50 EPA guidance recommends considering various statis tical assessments and other techniques of model versus observed pairs when conductin g a performance evaluation for regi onal haze. The other techniques include spatial plots, time series plots and qualitative de scriptions. Focus for the statistical assessment is on mean fractional bias and error.

The statistical evaluation of the Minnesota (MRPO) modeling performance was done for 24-hour averaging times. Fractional bias and error are evaluated fo r 36km and 12km (with plume-in-grid) grid scale modeling. There are a total of 32 twenty percent worst days. Eight days are BWCAW only, 10 days are VNP only, and 14 days are shared between the two Class I areas.

The conclusion of the performance evaluation sp ecifically at BWCAW and VNP indicates model performance for sulfate is good throughout the year for a ll organizations. Nitrate performance is best in the colder months (quarter 1 and 4), but has some issues; organic carbon performance is good, except for five days associated with wildfires (wildfire emi ssions were not included in the modeling). Fine soil (crustal), and elemental carbon performance is good. Coarse particulate mass performs poorly, which is expected because coarser primary particles (largely composed of wind borne dust) do not travel far and are influenced by very nearby sources. The grid scale of the modeling cannot account for these local influences. Also, wind borne dust was excluded from th e emissions inventory because of concerns about the transportable fraction of fugitive dust.

Comparison of Minnesota (MRPO) and CENRAP Model Performance Evaluation for Nitrate on Individual Days
The Minnesota (MRPO) and CENRAP performance evaluations s how some conflicting performance results for nitrate. Figure 8.2 depicts the difference between Minnesota (MRPO) modeling and CENRAP averaged over the 20 percent worst days at VNP and BWCAW. The differences appear on some individual of the 20 percent worst days. All these days occur in the winter and with winds traveling toward the Class I areas from the West and Northwest. The TSD c ontains the individual day model comparisons to observed – along with evidence of the direction of wind origination – for various individual days where the Minnesota (MRPO) modeling and CENRAP modeling perform very differently from one another. These are days where CENRAP overpredicts nitrate and the Minnesota (MRPO) model underpredicts nitrate.
Figure 8.2: Observations and Predictions by Minnesota (MRPO) and CENRAP Extinction by Species at Averaged Over 20 Percent Worst Days

VNP BWCAW

0 10 20 30 40 50 60 70 80

obs MN(mrpo) CenRAP
Avg

Julian DateExtinction (Mm-1) SO4 NO3 OC EC CRUSTAL CM

0 10 20 30 40 50 60 70 80

obs MN(mrpo) CENRAP
Avg

Julian dateExtinction (Mm-1) SO4 NO3 OC EC CRUSTAL CM51 Implications of the Performance Evaluation

1. Reasonable Progress Goal Development. The model performance, especially for sulfate, fits within performance goals for devel oping regional haze policy. 47 The underprediction of nitrate in the Minnesota (MRPO) modeling appears to be caused by a lack of ammonia available on the high nitrate days in the winter, which is discussed in more detail in the TSD supporting this SIP. This could make the model under-responsive to future NO X reductions. The CENRAP modeling, which appears to have too much ammonia, may ha ve the opposite response. The reality is likely somewhere in between. The “Supplemental Analysis/Weight of Evid ence Determination” section at the end of this Chapter 8 highlights how these model performance disc repancies for nitrate affect the results of the future year visibility conditions us ed to set reasonable progress goals.
Poor performance of coarse mass is not a concern as coarse particulate mass is not a prominent component in the extinction calculation, nor is it significant in the extinction calculated at BWCAW and VNP on the 20 percent worst days (see Appendix 5.2), so changes in this component will not affect the resulting future year projection.

2. Grid Scale Needs. The performance evaluation at the monito r locations is slightly better at 36km than for the Minnesota (MRPO) 12km(with plume-in-grid) grid for nitrate. Thus, the 36km modeling results are used for establishing the reasonable progr ess goal in deciviews at the monitor locations in BWCAW and VNP. The 12km (with plume-in-grid) resu lts are used to address local contributions to regional haze impacts throughout each Cla ss I area, but not for setting the RPG. 48 When using 12km (with plume-in-grid) results, the performance ev aluation results prompted Minnesota to assess visibility at multiple receptors located throughout VNP, BWCAW, and the western tip of Isle Royale.

3. Horizontal Extent of Domain. Minnesota (MRPO) modeling performance for nitrate suggests it could benefit from extending the domain further west to encompass additional sources in Canada. However, because of the uncertainty of Canadian emissions development, Minnesota kept Canadian emissions constant between the ba se and future year. Thus, exte nding the domain would have no affect on the reasonable progress goals established in this SIP. Further discussion of Canadian contributions to regional haze is found in the TSD.

4. Improvements to Emissions Inventory. Continued emissions /modeling and corresponding performance evaluations conducted by the RPOs ha ve resulted in the best emissions inventory possible to date. Ammonia emissions estimates a nd response to changes in ammonia levels as it affects NO X emissions reductions (see #1), and better unde rstanding of Canada’s inventory are areas to continue to explore. Based on the fit to m odel performance goals, and how the model results are applied in the establishment of reasonable progress goals, the MPCA believes that the base year and future year emission estimates used are sufficient to support this SIP.

5. Modifications of Models . Model performance evaluations over entire domains have resulted in changes to models, made for some reason othe r than achieving regional haze goals. An example would be the secondary organic aerosol (SOA) module improvements in CMAQ, and more recently in CAMx. Although overall model performance for organic carbon may improve, model results without those improvements are acceptable in BWCAW and VNP. Also, improved SOA will not affect reasonable progress in BWCAW and VNP beca use natural biogenic emissions – which are the main source of SOA formation at the Class I areas– remain constant in the baseline and future year. As no controls are proposed for trees, thus they are not accounted for in development of the RRFs.

47 U.S. EPA, OAQPS, 2007a.

48 Minnesota evaluated reasonable progress using the 12km (with plume-in-grid) results for several receptors throughout the Class I areas. The 2018 projected values rang ed from 18.3 – 19.0 decivi ews, with an average value of 18.7 deciviews in the BWCAW – the largest Class I area – for the 20 percent worst days. The average value is the same as the 36km result at the monitor location. The same is true for the 20 percent best days.52 Exploration of Potential Strategies fo r Demonstrating Reasonable Progress
In addition to the “on-the-books” c ontrols culminating in the 2018 em issions inventory described above,the MPCA explored other control measures, based on initial cost estimates by CENRAP, initial fourfactor analyses results from MRPO, and other meas ures under consideration in Minnesota. The MPCA looked at reductions in emissions resulting in a 0.25 lb/MMBtu limit on EGUs in Iowa, Missouri, North Dakota, and Wisconsin; reductions in SO 2 and NO X emissions from point sources in Northeast Minnesota equaling a 30 percent reduction from 2002 emissions; and additional controls on a Minnesota utility located in central Minnesota.

The source categories and regions approached while looking for additional reas onable control measures are based on an analysis of the source sectors a nd pollutant species in various geographic regions contributing to visibility impairment in 2018. The PSAT tool in CAMx was used in this assessment, and the focus was on the 20 percent worst days.

The 2018 projections indicate that Minnesota is by fa r the largest individual state contributing to light extinction due to nitrate, sulfate and ammonium in the BWCAW and VNP. The next largest individual state contributors at BWCAW are Wisconsin, Iowa, Illinois, Missouri, and North Dakota. The next largest individual state contributors at VNP ar e North Dakota, Iowa, Wisconsin, and Canada. 49 Figures 8.3 and 8.4 show the percent contributions of these i ndividual states, the remaining states, and Canada to total light extinction in 2018 presuming implementation of “on-the-books” controls.

In the Figures, Boundary Conditions (BC) account for 11% at BWCAW and 15% at VNP of the visibility impairment. Boundary conditions ar e source contributions outside of the modeling domain. In the case of the regional haze SIP (and ozone and PM 2.5 attainment modeling), they are the conditions derived from monthly averaged species output from the global scale chemical transport model (GEOS-CHEM) for the year 2002. Essentially, the GEOS-CHEM model is r un at a much coarser grid resolution to allow for modeling global emissions. The GEOS-CHEM model output is processed to remove discrepancies between the grid scales, etc., and the GEOS-CHE M and CAMx model are linked at the CAMx domain boundary.

Boundary conditions can transfer into and out of the CAMx modeling domain from the North, South, East and West. Ozone can also enter in from the top of the domain due to stratospheric infusion. Source apportionment techniques can only account for the total contribution of boundary conditions to the overall visibility conditions, which accounts for the conser vation of mass in the apportionment modeling.

49 Canada contributions based on 2005 emissions.53 Figure 8.3: Nitrate, Sulfate, Ammonium Contributions to Extinction (Mm -1 ) in 2018 at BWCAW by Region for W20% Days

Figure 8.4: Nitrate, Sulfate, Ammonium Contributions to Extinction (Mm -1 ) in 2018 at VNP by Region for W20% Days

From the base year (2002) to the future year (2018) , the regions specified above show less contribution to nitrate, sulfate and ammonium by somewhere between zero and about five percent. For example, Illinois contributes nearly five percent less at BWCAW in 2018 compared to 2002, resulting in a six percent contribution in 2018.

In 2018, Minnesota contributes mainly sulfate, with lesser amounts of nitrate and ammonium; sulfate formation appears to result nearly equally from EGUs and non-EGU point sources. Ammonium is almost exclusively from agricultural ammonia sources. Contri butions from other states have a similar makeup, but with less impacts from the non-EGU sector.

The CENRAP case shows a higher contributio n from nitrate sources than the Minnesota (MRPO) case and shows much less contribution to nitrate at BWCAW from onroad and nonroad sources in Minnesota, Illinois

6%

Iowa

8%

Wisconsin 10% Canada 3% AllOthers 22% BC 11%

Minnesota 28%

NorthDakota 6% Missouri 6% Boundary

Waters

Total Extinction of Nitrate, Sulfate & Ammonium:
32 Mm -1

Illinois 3%

Minnesota 31%

Canada 5% AllOthers 16% BC 15% Iowa 7%

Wisconsin 6% NorthDakota 13% Missouri 4% Voyageurs

Total Extinction of Nitrate, Sulfate & Ammonium:
32 Mm -154 Canada, North Dakota and the western United states in 2018 than 2002. The CENRAP case shows significantly less contribution of point source sulfate fr om other states, but for Minnesota, there is more contribution from non-EGU point source sulfate from the base year to the future year.

Over the 20 percent worst days, the Minnesota (MRPO) 12km PSAT results for 2018 indicate that Northeast Minnesota contributes 14 percent and the rest of Minnesota contributes 12 percent of total extinction at the BWCAW monitor location. Northeast Minnesota c ontributes 15 percent and the rest of Minnesota contributes 17 percent of total extinction at the VNP monitor location. Figures 8.5 and 8.6 illustrate the extinction contribution between Northeast Minnesota a nd the rest of Minnesota relative to contributions from all other geographic areas.

As noted above, the 12km results suggest that c ontribution assessments should be conducted at several receptor locations throughout the Cla ss I areas, rather than only at th e monitor locations. Contributions from local (Northeast Minnesota), mostly point, sources assessed across the Class I areas (VNP, BWCAW, and the tip of Western Isle Royale) range fr om 4 – 19 percent of total extinction. The four percent appears at the western tip of Isle Royale , while the 19 percent contribution is in BWCAW. Contributions from the rest of Minnesota range from 9 – 17 percent; nine percent at the western tip of Isle Royale and the 17 percent at VNP. Figure 8.6 s hows results at the receptor with the maximum (BWCAW, receptor 13) and the minimum (Western tip of Isle Royale) impact from Northeast Minnesota.

Figure 8.5: Percentage Contribution of Northe ast and Rest of Minnesota to BWCAW (BOWA1) and VNP (VOYA2) for W20% Days

Boundary Waters: Total Extinction 30 Mm -1

AllOther

62% BC 12%

NE Minnesota 14% Rest of Minnesota 12%

MN Total: 26% Voyageurs: Total Extinction 30 Mm -1

AllOther

53% BC 15% Rest of Minnesota 17%

NE Minnesota 15% MN Total: 32%55 Figure 8.6: Percentage Contribution of Northeast and Rest of Minnesota to Maximum (BOWA_13) and Minimum (ISLE) Receptors in the Class I areas for W20% Days

Minnesota (MRPO) results for the 12km (with plume-in-grid) analysis indicate sulfate is the major component contributed by point sources in Northeast Mi nnesota, while the rest of the state is more evenly divided between sulfate from point sources and ammonium from agricultural sources. Figure 8.7 illustrates the species contributions across the Class I areas. The Figure shows significantly less visibility impact due to Northeast Minnesota contributions to nitrate. This may seem counterintuitive because emissions of NO X in Northeast Minnesota are much higher than SO 2 . Point source emissions of NO X are about 37,500 tons per year, while SO 2 emissions are just over 8,000 tons per year.
Figure 8.7: Minnesota Contributions at Recep tors Placed Throughout Boundary Waters, Voyageurs and the tip of Isle Royale in 2018 by Species and Geographic Region

An explanation for this discrepancy in contribution of NO X and SO 2 to the 20 percent worst days is that particulate nitrate is an issue on fewer days and is fo rmed in the colder months. Viewing animated spatial plots of the source apportionment results on days with hi gh nitrate show that winds on several of the days winds appear to be coming from the west and northwest of Minnesota. Thus, the NO X emissions are not AllOther

57% BC 11% Rest of Minnesota 13%

NE Minnesota 19% MN Total: 32% Boundary Waters: Total Extinction 34 Mm -1 (BOWA_13) Isle Royale: Total Extinction 47 Mm -1 (ISLE_1)

AllOther

78% BC 10% Rest of Minnesota 9%

NE Minnesota 3% MN Total: 12%

0 1 2 3 4 5 6

SO4 NO3 NH4 SO4 NO3 NH4

NE Minnesota Rest of MinnesotaExtinction (Mm-1) lowerquartile minimum median maximum upperquartile

Rest MN Ext:
2.7 - 5.1 Mm -1 NE MN Ext:
1.6 - 6.5 Mm -156 moving north toward the Class I areas to form ammonium nitrate, but are moving to the East, Southeast and South.

Any actions taken based on these re sults should be done so with some caution. There are several remaining questions about ammonia emissions and ni trate. First, as mentioned previously, model performance for nitrate is worse than model pe rformance for sulfate, and the model generally underpredicts the formation of nitrate, likely due to an underestimation of wintertime ammonia. Without ammonia monitors located in Northeast Minnesota , it is not possible to measure actual ammonia concentrations. Also, as noted in Chapter 9 (related to BART), emissions estimates for NO X from nonEGU point sources in Northeastern Minnesota may be less accurate than those for other point sources.

Current future emissions estimates show significant SO 2 emission reductions in the area. If there is considerably more ammonia in the syst em than represented in the Minnesota (MRPO) case , more ammonia may be available to form ammonium nitrate and a gr eater model response may be seen from reductions in NO X emissions.

The uncertainties surrounding the impact of ammonia in the formation of ammonium nitrate and the resulting effect on visibility provide enough incentive not to discount the ability of NO X emission reductions to improve visibility. Therefore, poten tially reasonable 2018 control measures for visibility should continue to include measures to reduce NO X emissions.

The potentially reasonable measures explored in 2018 include:

1. Estimated emission levels applied to the Xcel Energy – Sherburne County plant (located in central Minnesota) based on a January 2007 announc ement of a potential project. This involves retrofit SCRs, fabric filters and dry sc rubbers on Units 1 and 2 and SCR on Unit 3; 50

2. A 0.25 lb/MMBtu emission rate from Iowa, Missour i, North Dakota and Wisconsin. These rates were applied to EGUs in those states that did not already have additional controls in place; and

3. Additional emissions reductions associated with the Northeast Minnesota Plan, under which the six counties in northeast Minnesota w ould maintain a 30% reduction in NO
x and SO 2 from 2002 emissions levels. About 21 percent of that reduction is already associated with Northeast Minnesota utility emission projections in the IP M version 3.0 “will do” scenario. The remaining approximately 10 percent was applied to taconite industry sources. The emission reductions were based on permit limits, furnace modifications in 20 06 and 2007, fuel switching, a new scrubber, newer rate information, and some reductions due to BART. The details of these future year emissions estimations are specified in the TSD.

Table 8.5 summarizes the 2018 point source emissions projections of SO 2 and NO X associated with the potentially reasonable control measures and the emissions change from the 2018 Minnesota (MRPO) emissions projections modeled.

50 In a December 2007 filin g, Xcel Energy dropped the prop osal for SCR from all three units due to cost concerns. Instead they propose low NO X burners for NO X controls. The new proposal projects less SO 2 emissions, but quite a bit more NO X emissions than the proposal reflected in the potentially reasonable control measures modeling.57 Table 8.5: 2018 Annual Potentially Reasonable Control Measures Emissions for Point Sources

Region SrcGroup Potentially Reasonable Control Measure Emission (ton/year) Emission Reduction from 2018 (ton/year) Percent Reduction from 2018

SO 2 NO X SO 2 NO X SO 2 NO X
Iowa EGU 66,700 58,500 -47,200 0 -41%
non-utility 49,000 32,500 0 0

Minnesota EGU 51,000 38, 200 -2,980 -10,700 -6% -22%
non-utility 26,000 57,700 -1 ,900 -6,550 -7% -10%

Missouri EGU 127,000 72,700 -111,000 0 -47%
non-utility 125,000 31,300 0 0

North Dakota EGU 46,000 39, 900 -12,300 -18,900 -21% -32%
non-utility 19,000 11,600 0 0

Wisconsin EGU 96,300 51,900 -48,200 0 -33%
non-utility 57,200 30,600 0 0

The visibility analysis methodology, described at the be ginning of this Chapter 8, was used to consider a reasonable progress goal were the potentially reasonable c ontrol measures in place. The resulting goals at BWCAW and VNP, due to the emissions reductions summa rized above, are shown in Figures 8.8 and 8.9. The results show a potential reasonable progress goal at BWCAW of 18.3 deciviews and a potential reasonable progress goal at VNP of 18.7 deciviews.

A straight line connecting the baseline visibility av erage (2000-2004) and natura l conditions (2064) form the uniform rate of progress or “glidepath.” Placeme nt relative to the line determines whether estimated future visibility (i.e. 2018) moves in a downward dire ction at such a rate that natural conditions are likely reached by 2064. A reasonable progress goal at VNP would be on the glidepath in 2018 if visibility impairment on the 20 percent worst visibility days were reduced from the baseline by a total of 1.7 deciviews. [ ))20042064()20042018(()1.125.19( −÷−×− ]. BWCAW would be on the glidepath in 2018 if visibility impairment on the 20 percent worst days were reduced from the baseline by 2 deciviews.

The reasonable progress assessment based on the potentially reasonable controls described above indicate that the goal for the 20 percent worst days would be a reduction from the baseline of 0.8 deciviews at VNP and 1.6 deciviews at BWCAW. Although the values show progress toward natural visibility conditions, obviously the 2018 goal would be positio ned above the uniform rate of progress toward natural visibility conditions at both Class I Areas.58 Figure 8.8: BWCAW 36-km Minnesota (MRPO) Potentially Reasonable Emissions Reduction Results

Figure 8.9: VNP 36-km Minnesota (MRPO) Potentially Reasonable Emissions Reduction Results Uniform Rate of Progress - Boundary Waters, MN

3.4 18.3 19.9

11.6

6.4 6.5

0.0 5.0 10.0 15.0 20.0 25.0

1990 2000 2010 2020 2030 2040 2050 2060 2070

YearDeciviews

Uniform Rate of Progress, Voyageurs MN

4.3 18.7

7.1 19.5

12.1

7.1

0.0 5.0 10.0 15.0 20.0 25.0

1990 2000 2010 2020 2030 2040 2050 2060 2070

YearDeciviews59 Reasonable Progress Strategy and Goals Rather than set a reasonable progress goal base d on potentialities, without determinations of reasonableness, the MPCA set the reasonable progre ss goal only considering the “on-the-books” controls (those controls expected due to programs other than the Regional Haze Rule) and the emissions strategy outlined in the Northeast Minnesota Plan. Based on these measures, the goal for the 20 percent worst days is a reduction from the baseline of 0.6 deci views at VNP and 1.3 deciviews at BWCAW, as presented in Table 8.6 and illustrated in Figures 8.10 and 8.11. Further information on the reasonable progress goals, and why they are set at this level, is presented in Chapter 10.

Table 8.6: Reasonable Progress Goals for BWCAW and VNP
Class I Area Days Represented Reasonable Progress Goal for 2018 in deciviews Difference Between RPG and URP in deciviews BWCAW 20% Worst 18.6 0.7 20% Best 6.4 0.0 VNP 20% Worst 18.9 1.1 20% Best 7.0 0.0

Figure 8.10: BWCAW 36-km Minnesota (MRPO) Results

Uniform Rate of Progress - Boundary Waters, MN

3.4 18.6

11.6 19.9

6.4 6.5

0.0 5.0 10.0 15.0 20.0 25.0

1990 2000 2010 2020 2030 2040 2050 2060 2070

YearDeciviews60 Figure 8.11: VNP 36-km Minnesota (MRPO) Results

Supplemental Analysis/ Weight of Evidence Determination As mentioned above, there are differences among th e future year projections modeled by CENRAP, MRPO and Minnesota (MRPO) available to derive reasonable progress goals for BWCAW and VNP. The resulting future year projections with on-the-books controls and some reasons for the differences are summarized here. Because the MRPO conducted modeling for both a 2002 and a 2005 base year, the MRPO 2002 base year modeling will be discussed first in relation to CENRAP and Minnesota (MRPO) modeling, which also both use a 2002 base year. Discussion of the use of the 2005 base year follows.

In order to do an equitable comparison, the visi bility conditions and future year values for each organization were calculated using the same mon itoring data establishing the baseline. The only difference lies in the modeled base year and future ye ar concentrations, which are used to calculate RRFs applied to the baseline monitoring data.

Table 8.7 contains the Minnesota (MRPO) projections 51 for the 20 percent worst days at BWCAW and VNP along with the results of other modeling work c onducted by CENRAP, and by MRPO for the 2002 base year. For the 20 percent worst days, the CENRAP results show future year projections that are the same at BWCAW, and 0.4 deciviews closer to the glidepath at VNP, than Minnesota (MRPO) . The Minnesota (MRPO) projections are 0.3 deciviews closer to the glidepath at both BWCAW and VNP than MRPO.

51 Minnesota (MRPO) values for the 12km grid assessed for several receptors throughout the Cl ass I areas, indicated a range of 2018 projected values from 18.3 – 19.0 deciviews, with an average value of 18.7 deciviews in Boundary Waters for the 20 percent worst days. The average value is the same as the 36km result at the monitor location. The same is true for the 20 percent best days. It does not ap pear necessary to set separate goals for various locations across the Class I area based on the 12km results. Uniform Rate of Progress - Voyageurs, MN

4.3 18.9

12.1 19.5

7.1 7.1

0.0 5.0 10.0 15.0 20.0 25.0

1990 2000 2010 2020 2030 2040 2050 2060 2070

YearDeciviews61 Table 8.7: Visibility Projections to 2018 using CENRAP, Minnesota (MRPO) , and MRPO Modeling from a 2002 Base Year for the 20% Worst Days

Reviewing the RRFs for the individual species can help gain a better understanding of why there are differences in the position relative to the URP. Tabl e 8.8 contains the RRFs by visibility component, or species, for each organization. A factor above 1. 000 means the modeled concentration increases from 2002 to 2018. A factor below 1.000 means the modeled concentration decreases from 2002 to 2018.
Table 8.8: Relative Response Factors to 2018 using CENRAP, Minnesota (MRPO) , and MRPO Modeling from a 2002 Base Year for the 20% Worst Days

Evaluation of the RRFs for BWCAW and VNP focuses on sulfate and nitrate. Both of these components figure prominently in the extinction calculation (see Ch apter 5). Crustal/soil and coarse mass are not prominent components in the extinction calculation, nor are they significant in the extinction calculated at BWCAW and VNP on the 20 percent worst days (see Appendix 5.2), so changes in these components will not affect the resulting future year projection. Elemental carbon has low measured values at the two Class I areas; even though the extinction calculation multiplies the observed concentration of elemental carbon by a factor of 10, it still does not feature prominently in the future year projections at BWCAW and VNP. The RRFs for organic carbon are similar between the various analyses, so no further discussion is warranted for that component.

Because the 2002 MRPO modeling is the basis for the Minnesota (MRPO) analysis, it is easier to compare these two analyses. According to the RRFs, the most noticeable differences between MRPO and Minnesota (MRPO) cases are in the response to sulfate reductions. As expected, the Minnesota (MRPO) modeling shows greater reductions due to the EGU emi ssion projections associated with IPM version 3.0 “will do”. The MRPO modeling for the 2002 base year used IPM version 2.1.9(VISTAS).

The noticeable differences in RRFs for sulfate between CENRAP and Minnesota (MRPO) are also mainly due to the differences in future year EGU emissi on estimates. This conclusion is drawn from the similarity in the MRPO and CENRAP sulfat e RRFs; both organizations used IPM version 2.1.9(VISTAS). Baseline 2018 URP

(dv) (dv) (dv) difference (dv) Boundary Waters CenRAP 36 2002 19.9 17.9 18.6 0.7 Boundary Waters Minnesota 36 2002 19.9 17.9 18.6 0.7 Boundary Waters MRPO 36 2002 19.9 17.9 18.9 1.0 Voyageurs CenRAP 36 2002 19.5 17.8 18.6 0.8 Voyageurs Minnesota 36 2002 19.5 17.8 18.9 1.1 Voyageurs MRPO 36 2002 19.5 17.8 19.2 1.4 2018 Projected

Class I Area Name Organization Grid Resolution Base Year

sulfate nitrate organic carbon elemental carbon crustal/
soil coarse

mass Boundary Waters CenRAP 36 2002 0.870 0.790 0.947 0.756 1.102 1.062 Boundary Waters Minnesota 36 2002 0.791 0.921 0.943 0.786 1.402 1.127 Boundary Waters MRPO 36 2002 0.877 0.929 0.949 0.788 1.265 1.112
Voyageurs CenRAP 36 2002 0.932 0.817 0.954 0.796 1.101 1.091 Voyageurs Minnesota 36 2002 0.848 1.031 0.954 0.834 1.275 1.069 Voyageurs MRPO 36 2002 0.949 1.054 0.956 0.830 1.200 1.064 Relative Response Factors

Class I Area Name Organization Grid Base Year62 Even more noticeable than the differences in sulf ate RRFs, are the differences in RRFs for nitrate between the CENRAP and the MRPO and Minnesota (MRPO). cases. CENRAP RRFs show significantly more reductions in nitrate. These differences in nitrate RRFs overcome the sulfate decreases in the Minnesota (MRPO) modeling attributable to the change from IPM2.1.9 to IPM3.0, so that overall, the CENRAP position in relation to the URP is the same as the Minnesota (MRPO) results at BWCAW and is closer to the URP than the Minnesota (MRPO) results at VNP. The reasons for these differences are more complicated to discern because there are more underlyi ng differences in the emissions inventories. The MPCA suspects that the greater reductions in nitrat e in the CENRAP modeling are associated with the following:

• While the Minnesota (MRPO) case keeps Canada emissions consta nt between the base year and the future year, the CENRAP case uses a 2000 and a projected 2018 Canadian inventory. Projected emissions in the CENRAP case contain lower Canadian NO X emissions in 2018 than in 2002. Thus, these emissions reductions could be reflected in the CENRAP RRF; and

• The CENRAP case has significantly more ammonia than the Minnesota (MRPO) case. Model performance evaluation of the CENRAP modeling in dicates overprediction of ammonium nitrate formation at BWCAW and VNP compared to observe d values collected at monitoring stations. This is likely caused by additional NO X and a significant amount of available ammonia with which to react. These conditions allow the mode l to respond well to future projected reductions in NO X emissions, possibly even over-stating them.

On the other hand, the Minnesota (MRPO) case underpredicts ammonium nitrate formation on the same days. The Minnesota (MRPO) case does not appear to have much available ammonia in the winter to form the same level of ammonium nitrate from NO X emissions as observed. In the future emissions estimates, NO X in the Minnesota (MRPO) case are reduced while ammonia significantly increases; the increased ammonia a llows the model to form ammonium nitrate. Even though NO X emissions decrease, the corresponding increase in ammonia emissions and ammonium nitrate formation may prevent model response to the reduction in NO X emissions. Thus, the CENRAP case would reflect greater nitrate reductions in the RRF than the Minnesota (MRPO) case. In fact, the Minnesota (MRPO) RRFs show a slight increase in nitrate at VNP from 2002 to 2018.

Based on the above premise regarding model response in nitrate RRF development above, the MPCA would anticipate the nitrate RRF would likely be somewhere between the CENRAP case (nitrate RRF of 0.790 at BWCAW and 0.817 at VNP) and the Minnesota (MRPO) case (nitrate RRF of 0.921 at BWCAW and 1.031 at VNP). Should that prove true, visibility conditions would be closer to the URP in 2018 than projected in this SIP.

As mentioned above, the MRPO switched from a 2002 ba se year to a 2005 base year for developing relative response factors. These factors are a pplied to the same 2000-2004 baseline. Applying substantially the same control measures 52 to the 2005 base year as the 2002 base year resulted in future year projections at, or below, the URP at BWCAW and VNP. The resulting future year projections are 0.7 deciviews lower at BWCAW and 1.2 deci views lower at VNP than the Minnesota (MRPO) results.

52 There are also emissions inventory diff erences. For example, the MRPO 2005 case was conducted using the 2005 state emissions inventory for Illinois, Indiana, Iowa, Michigan, Minnesota (point sources), Ohio and Wisconsin, and more updated 2002 emissions inventory with growth factors to 2005 applied for other states (and Minnesota sources other than point sources). The MRPO 2005 case does not include the revised growth estimates for taconite facilities in Northeast Minnesota or the Northe ast Minnesota Plan in the future year emissions estimates.63 Inspection of the source apportionment results from the MRPO 2005 and the Minnesota (MRPO) 2002 cases suggests that much of the difference is due to the us e of different meteorology, and a different set of 20 percent worst days. The modeled RRFs for 2005 ar e established using the 20 percent worst days determined from 2005 monitoring data. Apportioning the 2005 model results to geographic regions of visibility impact on the 20 percent worst days and comp aring that to similar apportionment results for the Minnesota (MRPO) 2002 case shows less contribution from Minneso ta sources, much less contribution from the Western United States and Canada, and more cont ribution from states to the East and Southeast of BWCAW and VNP. The source apportionment results are available in the TSD.

In order to verify the impact of the different meteorological year on the resulting RRFs, Minnesota modeled the 2002 emissions inventory (mi nus 2002 biogenic emissions) from the Minnesota (MRPO) case with the 2005 meteorology and 2005 biogenic em issions used in the MRPO 2005 case. The 2005 biogenic emissions replace the 2002 biogenic emissions because these emissions are highly dependent on meteorology. Because biogenic emissions remain the sa me from the base year to the future year, use of 2005 biogenics does not influence the resulting RRFs.

Table 8.9 shows the future year projections resulting from this exercise. Table 8.10 shows the RRFs. The results of the Minnesota 2002 emissions\2005 mete orology future year projections are shown in relation to the Minnesota (MRPO) 2002 53 case and the MRPO 2005 case. The use of 2005 meteorology coupled with 2002 anthropogenic emissions results in fu ture year projections 0.4 deciviews closer to the URP at BWCAW and 0.8 deciviews closer to the URP at VNP than the Minnesota (MRPO) 2002 case. The results demonstrate that the RRF, and hence, future year projections, are sensitive to meteorology and where the emission reductions occur geographically. In this case, it appears that the RRFs developed using 2005 meteorology are more sensitive to emission re ductions that occur in states located to the East and Southeast of BWCAW and VNP.
Table 8.9: Visibility Projections to 2018 using 2002 and 2005 Meteorology for the W20% Days

53 The 2002 emissions/2005 meteorology modeling exercise was conducted using a future year that did not include the Northeast Minnesota Plan. Thus, the Minnesota (MRPO) case used for comparison in Table 8.10 has a future year projection 0.1 deciviews greater both BWCAW and VN P than Minnesota’s reasonable progress goal. Baseline 2018 URP

(dv) (dv) (dv) difference (dv) Boundary Waters Minnesota 36 2002* 19.9 17.9 18.7 0.8 Boundary Waters Minnesota 36 2002/05 met 19.9 17.9 18.3 0.4 Boundary Waters MRPO 36 2005 19.9 17.9 17.9 0.0 Voyageurs Minnesota 36 2002* 19.5 17.8 19.0 1.2 Voyageurs Minnesota 36 2002/05 met 19.5 17.8 18.2 0.4 Voyageurs MRPO 36 2005 19.5 17.8 17.7 -0.1 * The base year (2002) modeling used in the 2002-2005 comparison does not contain the NE Minnesota Plan Class I Area Name Organization Grid Resolution Base Year 2018 Projected64 Table 8.10: RRFs for 2018 using 2002 and 2005 Meteorology for the W20%

The supplemental analysis shows that the three m odeling analyses produce RRFs that lead to varying approximations of future visibility conditions presum ing the same “on-the-books” controls. In addition to the “on-the-books” controls, the Minnesota (MRPO) case also includes the Northeast Minnesota Plan; yet the reasonable progress goals established in this SIP ar e conservative in relation to those that would be established using the other modeling analyses. Nevertheless, all the es timated future visibility conditions are moving in the desired downward dir ection toward natural conditions.

Continued emission inventory improvement projects are active, and a new base year emissions and meteorology, likely a 2007/2008 base year, are expected to be available for the five-year SIP assessment. The continuing analyses will provide additional evidence supporting future year projections, and establishment of reasonable progress goals toward natural visibility conditions.

Data Access All data files used to support this SIP and the accompanying TSD are archived at the MPCA offices and provision has been made to maintain them. The MR PO and CENRAP maintain their own files for their work. The Minnesota (MRPO) files are generated and read on a Linux operating platform. Model outputs are processed with a series of Fortran programs invoked by C-shell scripts. To obtain files used in the analyses contact Margaret McCourtney at 651- 757-2558 or margaret.m ccourtney@state.mn.us. sulfate nitrate organic carbon elemental carbon crustal/ soil coarse

mass Boundary Waters Minnesota 36 2002* 0.798 0.936 0.945 0.786 1.402 1.127 Boundary Waters Minnesota 36 2002/05 met 0.755 0.886 0.925 0.750 1.375 1.108 Boundary Waters MRPO 36 2005 0.746 0.849 0.990 0.800 1.269 0.596 Voyageurs Minnesota 36 2002* 0.855 1.035 0.956 0.834 1.275 1.069 Voyageurs Minnesota 36 2002/05 met 0.768 0.898 0.937 0.780 1.342 1.065 Voyageurs MRPO 36 2005 0.761 0.822 0.976 0.772 1.239 0.637 * The base year (2002) modeling used in the 2002-2005 comparison does not contain the NE Minnesota Plan Relative Response Factors

Class I Area Name Organization Grid Base Year65 

### Chapter 9. Best Available Retrofit Technology

The EPA’s 1999 Regional Haze Rule singles out certa in older emission sources that have not been regulated under other provisions of the Clean Air Act for additional controls. The state of Minnesota is requiring these older sources that contribute to visibi lity impairment in Class I areas to install Best Available Retrofit Technology (BART). On July 6, 2005, EPA published a revised final rule, including 40 CFR 51, Appendix Y, Guidelines for BART Determinations Under the Regional Haze Rule, which provides direction for determining which older source s may need to install BART and for determining BART.

BART-Eligible Sources in Minnesota The facilities with BART-eligible units in Minnesota ar e shown in Table 9.1. A detailed description of each BART-eligible emission unit is included in Appendix 9.1.

The BART-eligible sources were identified using the methodology in the Guidelines for BART Determinations under the Regional Haze Rules or Guidelines , referenced above.

To identify the BART-eligible emission units in Table 9.1, MPCA used the following criteria:

• One, or more, emission(s) units at the facility fit within one of the twenty-six (26) categories listed in the Guidelines ;

• The emission unit(s) were in existence on Augus t 7, 1977 and began operation at some point on or after August 7, 1962; and

• The sum of the potential emissions from all emission unit(s) identified in the previous two bullets was greater than 250 tons per year of the visibility-impairing pollutants: sulfur dioxide (SO 2 ), nitrogen oxide (NO
x ), and PM 10
. Table 9.1: Minnesota Facilities with BART-eligible Units

BART Source Category Name SIC Code Facility ID Facility Name BART Emission Units (Emission Unit No.)

Fossil Fuel-fired Steam Electric Plants > 250 MMBtu/hour --

Electric Generating Units (EGU) 4931 2709900001 Austin Utilities NE Power Station *Boiler No. 1 (EU001) 4931 2713700027 Hibbing Public Utilities North boiler (EU003) 4911 2703100001 MN Power, Taconite Harbor *Boiler no. 3 (EU003) 4911 2706100004 MN Power, Boswell Energy Center *Boiler no. 3 (EU003)
4931 2701500010 New Ulm Public Utilities No. 4 boiler (EU003)
4911 2711100002 Otter Tail Power Hoot Lake *Unit 3 boiler (EU003)

4911 2710900011 Rochester Public Utilities, Silver Lake Unit #3 boiler, *Unit #4 boiler (EU003, EU004) 4911 2713700028 Virginia Public Utilities Boiler no. 9 (EU003) 4911 2714100004 Xcel Energy, Sherco *Boilers 1 and 2 (EU001,EU002) 4911 2716300005 Xcel Energy, Allen S King *Boiler 1 (EU001) 4911 2705300015 Xcel Energy, Riverside *Boiler 8 (EU003)

Petroleum Refineries 2911 2703700011 Flint Hills Resources LP – Pine Bend 15 emission units 2911 2716300003 Marathon Ashland Petroleum LLC 24 emission units

Taconite Ore Processing Plants 1011 2713700063 US Steel, Keewatin Taconite 32 emission units 1011 2713700061 Hibbing Taconite Co 29 emission units 1011 2713700005 US Steel, Minntac 375 emission units

1011 2713700113 United Taconite LLC (formerly EVTAC) 54 emission units

1011 2713700062 ArcelorMittal (formerly Ispat Inland Mining) 32 emission units66 BART Source Category Name SIC Code Facility ID Facility Name BART Emission Units (Emission Unit No.)

1011 2707500003 Northshore Mining Company, Silver Bay 43 emission units (*EU002 was a CAIR EGU)

Fossil fuel fired boilers of more than 250 MMBTU/hr 2063 2711900002 American Crystal Sugar, E. Gr. Forks Boilers 1 and 2 (EU001, EU002)

2063 2712900014 Southern MN Beet Sugar Boiler no. 1 (EU001)

Kraft Pulp Mills 2621 2707100002 Boise White Paper LLC, Intl Falls #2 boiler, recovery furnace, smelt dissolving tank (EU340, EU320, EU322)
2611 2701700002 Sappi Cloquet, LLC #7, #8 power boilers (EU002, EU037)
Iron and Steel Mill Plants 3312 2712300055 Gerdau Ameristeel Reheat furnace (EU004)

Secondary Metal Production Facilities 3341 2703700016 Gopher Resources 3 emission units in reverberatory furnace area (EU003, EU007, EU008) * These Electric Generating Units were initially cove red under the Clean Air In terstate Rule (CAIR).

The Guidelines recommend addressing the visibility-impairing pollutants SO 2 , NO X , and Particulate Matter. The MPCA addressed thes e three pollutants and used partic ulate matter less than ten (10) microns in diameter (PM 10 ) as an indicator for particulate matter to identify BART-eligible units.

Consistent with the Guidelines , MPCA did not evaluate emissions of Volatile Organic Compounds (VOCs) and ammonia in BART de terminations for these reasons:

Ammonia : In the Guidelines , EPA suggests that states consider ammonia as a precursor to PM 2.5 formation on a case-by-case basis. They make th e point that “states are required to make BART determinations only for stationary sources that fall w ithin certain industrial categories.” A perusal of the specific industrial categories in Minnesota indicates that these sources do not emit ammonia in a “significant” (potential to emit 250 tons per year or more) amount. Thus, the inclusion of ammonia – while a potential contributor to visibility impairme nt – would not impact the MPCA’s BART-eligibility determination. Ammonia from sour ces that may contribute to visibility impairment is included in the regional scale modeling used in this SIP.

VOCs : In the Guidelines , EPA suggests that states consider VOCs as a precursor to PM 2.5 formation on a case-by-case basis. Only specific VOC compounds form secondary organic aerosols that affect visibility, and these compounds are a fraction of the total VOCs re ported in the emissions inventory. For the BART analysis, MPCA does not have the breakdown of VOC emissions necessary to model those that only impair visibility. Although not included in BA RT, VOCs – both anthropogenic and biogenic – are included in the regional scale modeling used in this SIP

The MPCA identified BART-eligible sources in th e state by sending a Request for Information by certified mail to all facilities in the state that are major sources for New Source Review. The Request for Information asked the facility to identify its industr ial category, any units c onstructed between 1962 and 1977, and the potential emissions from these units. If the facility identified BART-eligible units, additional information about those units was requested so that the MPCA could model the visibility impacts of those units. The MPCA also reviewed its databases to ensure that no BART-eligible units may have been overlooked in the survey process. Additi onal information about the identification process is contained in Appendix 9.1.67 Determination of Sources Subject to BART
Under the Guidelines , the state has the following options regarding its BART-eligible sources: a) make BART determinations for all sources ; or b) consider exempting some sources from BART because they do not cause or contribute to visibility impairment in a Class I area. The MPCA chose option b. The Guidelines then suggest the following three modeling opt ions for determining which sources may be exempt:

• Individual source attribution approach (dispersion modeling).

• Use of model plants to exempt sources with common characteristics.

• Cumulative modeling to show that no sources in a state are subject to BART.
The state of Minnesota chose to use the individual so urce attribution approach to determine which sources are subject to BART.

The MPCA performed source-specific analyses usin g the CALPUFF model to determine which sources cause or contribute to visibility impairment; the CALPUFF modeling protocol used for determining which facilities are subject to BART is included in Appendix 9.2.

In accordance with the recommendation of the Guidelines , a contribution threshold of 0.5 deciviews was used in determining those sources that are s ubject to BART. The MPCA chose to use the 98 th percentile 0.5 deciview threshold because EPA states in its Guidelines , “As a general matter, any threshold that you use for determining whether a source ‘contributes’ to vi sibility impairment should not be higher than 0.5 deciviews.” 54 The MPCA is not aware of any special circum stances in Minnesota that would merit the use of a higher threshold. The Guidelines provide states the discretion to set a threshold below 0.5 deciviews if “the location of a large number of BART-eligible s ources within the state and in proximity to a Class I area justifies this approach.”

The MPCA took into account four factors in analyzing the use of the 0.5 deciview threshold for subjectto-BART:

• How close the BART-eligible source contributions are to the 0.5 threshold;

• Total facility control measures/emission reductions gained by federal regulations and during the establishment of reasonable progress goals in the RH SIP;

• Visibility improvement gains from BART; and

• The tool (CALPUFF) used to determine subject-to-BART status and its applicability to regional haze analyses.
Although the MPCA could set the contribution threshol d lower than 0.5 deciviews and is cognizant of a number of existing sources in close proximity to Class I areas, the modeling showed no sources causing impacts at levels just slightly below 0.5 deciviews. The 98 th percentile deciview values for those subjectto-BART range from 0.6 – 4.4 deciviews, while the 98 th percentile deciview values for those not subjectto-BART range from 0.0 – 0.4 deciviews.

A total of 15 facilities with BART-eligible sources were determined not subject-to-BART based on the 0.5 deciview threshold. Of those 15 facilities, three ar e subject to the Northeast Minnesota Plan and three are EGUs that were initially subject to CAIR. Mi nnesota was initially included in CAIR, leading many utilities to install controls in anticipation of CAIR compliance. EPA has recently published a proposed stay of CAIR in Minnesota until there is a repromul gated CAIR rule. Should Minnesota not be included

54 Regional Haze Regulations and Guidelines for Best Available Retrofit Technology (BART) Determinations, Final Rule, (2005). p. 3916168 in a repromulgated rule, two of the three EGUs th at showed modeling results closest to the BART threshold (Austin Public Utilities and Otter Tail Powe r Hoot Lake) will be re-evaluated for reasonable progress controls at the time of the Five Year SIP Assessment.

Based on these facts, the application of BART woul d likely have little impact on the emission reductions expected from these facilities. Of the remaining ni ne facilities not subject to the Northeast Minnesota Plan or initially subject to CAIR, all have 98 th percentile deciview values of 0.2 deciviews or less. Therefore, MPCA did not readjust the contribution threshold chosen for exempting sources from BART.

The MPCA published the proposed BART implementation strategy in the State Register on September 6, 2005; comments were requested and received, and the MPCA responded to the comments. Appendix 9.2 details where to find information on the strategy and the MPCA’s response to comments.

The facilities found by the MPCA to be subject to BART are shown in Table 9.2. Again, Appendix 9.2 contains information on how to find the detailed resu lts of the modeling analyses for each BART-eligible source. Facilities found to be subject to BART mu st complete a BART analysis, unless the MPCA exempted them from that requirement.
Table 9.2: Facilities with Units Subject to BART in Minnesota

BART Source Category Name Facility ID Facility Name Emission Units Subject to BART (Primary Contributor) Max. Modeled # days > 0.50 dv from 2002-2004 a
Taconite ore processing facilities 2713700063 US Steel, Keewatin Taconite 32 emission units (Line 1) 247

2713700061 Hibbing Taconite Co 29 emission units (Lines 1,2,3) 247

2713700005 US Steel, Minntac 375 emission units (Lines 3,4,5,6,7) 530

2713700113 United Taconite 54 emission units (Lines 1,2) 442
2713700062 ArcelorMittal 32 emission units (Line 1) 228

2707500003 Northshore Mining, Silver Bay 42 taconite processing emission units (Lines 11,12) 169

Fossil Fuel-fired Steam Electric Plants > 250 MMBtu/hour –

Electric Generating Units (EGU) 2703100001 MN Power, Taconite Harbor Boiler No. 3 (EU003) 226

2706100004 MN Power, Boswell Energy Center Boiler No. 3 (EU003) 205

2707500003 Northshore Mining, Silver Bay Boiler No. 2 only (EU002) 316

2710900011 Rochester Public Utilities, Silver Lake Unit #3 boiler, Unit #4 boiler (EU003, EU004) 17

2714100004 Xcel Energy, Sherco Boilers 1 and 2 (EU001, EU002) 230

a Complete modeling results are availabl e at http://www.pca.state.mn.us/publi cations/aq-sip2-07.pdf. Results are pre-control upgrades.69 

### Determination of BART Requirements for Subject-to-BART Sources
BART is the emission limit for each pollutant based on the degree of reduction achievable through the application of the best system of continuous emission reduction, taking into consideration: the costs of compliance, the energy and the non-air quality envi ronmental impacts of compliance, any pollution control equipment in use at the source, the remaining useful life of the source, and the degree of improvement in visibility which may reasonably be antic ipated to result. However, a state is not required to make a determination of BART for SO 2 , NO X, or PM 10 if a BART-eligible source has the potential to emit (PTE) less than 40 tons per year of SO 2 or NO X or less than 15 tons per year for PM 10
.

EPA’s BART Guidelines set forth a process for making BART determinations that may be used by states; this process is mandatory for 750 MW power plant s ources, but advisory for other sources. The MPCA’s BART determinations are influenced largely by two factors: the technology available and the costs of compliance. The technology available particularly infl uenced the determination of BART for the taconite facilities. In some other cases, technically feasible a nd cost effective controls were not determined to be BART due to concern over other environmental impact s, namely water discharge. Existing air pollution control equipment at the source is taken into account in the cost effectiveness of controls, and where it impacts the determination of feasible additional contro ls. In no instance did the MPCA or an affected facility identify units where the emitting unit’s remaining useful life mitigated the selected control option. All units are presumed to continue operating for at least 20 years for the cost estimating procedures.

Finally, the MPCA largely did not rely on evaluatio ns of resulting visibility improvement in choosing controls, except in a case where a facility was only marginally subject-to-BART, and therefore BART controls were not required on one of two BART units . In cases where full BART determinations were requested, the facilities estimated visibility improvement from various BART options, and these are included in the memos documenting the MPCA’s BART determinations. Howe ver, the MPCA’s position is that cost-effective controls should be installed, ev en if they result in limited improvement in visibility, and technically infeasible or not cost-effective cont rols are not required under BART, even if they result in significant visibility improvement. Controls appr oximating MPCA’s BART de terminations for EGUs were included in the visibility modeling used to se t the RPGs, thereby demonstrating “the degree of visibility improvement which may reasonably be anticipated from the use of BART.”

EGU BART Determinations The MPCA initially did not perform a BART determination for subject-to-BART EGUs to evaluate NO X and SO 2 because of Minnesota’s inclusion in the Clean Ai r Interstate Rule (CAIR). EPA found that, as a whole, the CAIR cap-and-trade program improves visi bility more than implementing BART in states affected by CAIR. A state that opts to participate in the CAIR program need not require affected BARTeligible EGUs to install, operate, and maintain BART. BART-eligible EGUs in both CAIR states and non-CAIR states must submit a BART determination if the state finds they are subject to BART. If a state accepts EPA’s overall finding that CAIR “substitutes” for BART, then the BART determination need only be done for PM emissions, as NO X and SO 2 emissions are addressed by CAIR.

In addition, as the MPCA began the process of looki ng at BART controls, it appeared that all but one EGU otherwise subject-to-BART would be adding controls with implemen tation expected by 2010. This is shown in Table 9.3.

However, subsequent legal uncerta inty concerning CAIR, as well as several comments received on the draft SIP, led to reconsideration of the decision to allow CAIR to substitute for BART. Although CAIR went into effect, as written, on January 1, 2009, EPA issued a proposed rule on May 12, 2009 to stay the70 effectiveness of CAIR in Minnesota. 55 The MPCA therefore has made BART determinations for the six EGUs found to be subject to BART. In most of these cases, planned controls for SO 2 and NO X have been determined to represent BA RT levels of control.

The MPCA modeled the PM visibility impacts from each subject-to-BART EGU and found that impacts were less than 0.20 deciview for all units, also show n in Table 9.3. Because of the small impact from the PM emissions, the MPCA determined that any additional control would not be cost effective, particularly when weighed against the small amount of visibility improvement and other environmental impacts. In addition, all of the subject-to-BART EGUs already ha ve PM controls installed and some are planning PM control upgrades. 56 Therefore, each facility’s existing controls and emission limits for PM were considered to be BART.

Table 9.3: Planned Control Upgrades by Subject-to-BART EGUs and Projected PM Contribution to Visibility Impairment

Facility ID Facility Name Emission Units Subject to BART Estimated % Reduction Over Average

‘01-‘03 lb/ MMBTU Emission Rate Estimated Year Control

Upgrade Project Completed Maximum Modeled Contribution to Visibility Impairment from PM a ( Δ dv)

2703100001 MN Power, Taconite Harbor Boiler no. 3 (EU003) NO X - 66% SO 2 - 63% 2009 0.078

2706100004 MN Power, Boswell Boiler no. 3 (EU003) NO X - 81% SO 2 - 90% PM 10 - 65% 2009 0.048

2710900011 Rochester Public Utilities, Silver Lake b Unit #4 boiler (EU004) NO X - 63% SO 2 - 85% 2009 – NO X 2010 – SO 2 0.005

2714100004 Xcel Energy, Sherco Boilers 1 and 2 (EU001, EU002) NO X -43-45% 2006-2008 0.047

2707500003 Northshore Mining, Silver Bay Boiler 2 (EU002) No upgrades announced No upgrades announced 0.16

a Results shown are from CAMx modeling performed by MPCA staff using 2002 emissions input. More information can be found in the TSD.

b The MPCA has determined that BART for Unit 3 is no additional control because Units 3 and 4 combined were found to be only “marginally” subject-to-BART and signifi cant control upgrades are plan ned for Unit 4, the larger BART unit. Unit 4 impacted visibility more than Unit 3 as its 2002 SO 2 emissions were about four times those of Unit 3. In addition, the Title V permit issued in Septem ber 2007 requires additional em ission reduction strategies (to be determined) for SO 2 attainment.

55 74 FR 22147

56 Minnesota Power is installing BACT-like PM controls on Boswell 3 as part of its voluntary emission reduction project.71 Table 9.4 documents the NO X and SO 2 BART determinations made by the MPCA for the subject-to BART EGUs.

Table 9.4: NO X and SO 2 BART Determinations for EGUs

Facility Name Emission Unit NO X Bart Technology NO X BART Limit (lbs/MMBtu) SO 2 BART Technology SO 2 BART Limit (lbs/MMBtu) MN Power, Taconite Harbor Boiler no. 3 (EU003) ROFA 0.20 FSI and FF 0.40

MN Power, Boswell Boiler no. 3 (EU003) LNB + OFA, SCR 0.07 Wet scrubber 0.09

Rochester Public Utilities, Silver Lake Unit #3 boiler (EU003) No additional No Limit No additional 2.30

Unit #4 boiler

(EU004) ROFA/Rotamix 0.25 Spray dryer absorber 0.60

Xcel Energy, Sherco Boiler 1 (EU001) LNB +SOFA+ Combustion Optimization 0.15 Retrofit FGD with sparger tubes 0.12
Boiler 2 (EU002) Combustion optimization

Northshore Mining, Silver Bay Boiler 1 (EU001) LNB + OFA 0.41 Biomass co-fire 0.41

Boiler 2 (EU002) LNB + OFA 0.40 Biomass co-fire 0.48

Appendix 9.4 contains the MPCA’s full BART anal ysis and determinations , including appropriate emission limits, for NO X , SO 2 , and PM 10 at each subject-to-BART EGU.

As shown in Appendix 9.7, the MPCA promulgate d a rule that makes the requirements of BART “Applicable Requirements” for facilities. The MPCA will therefore add BART requirements to affected facility’s Title V permits as a basis for permit limits. Due to the length of time that is necessary to reopen a permit and amend requirements, the MPCA is not likely to have these requirements fully incorporated into Title V permits until the Five Y ear SIP Assessment. Since Minnesota rules mandate that permits include all applicable requirement s, the BART requirements must be included.

Visibility Improvement The MPCA modeled the visibility improvement expected from the installation of the BART controls shown in Table 9.4. The modeling compared actua l emissions as modeled for the 2002 base year modeling to the emissions expected with the installa tion of BART, using two years of meteorology (2002 and 2005). The overall results are documented in each BART determination memo in Appendix 9.4, with more explanation of the methodology and mo re detailed results in Appendix 9.5.

Taconite BART Determinations Table 9.5, below, describes the characteristics of Minnesota’s taconite pellet furnaces, which are the other main source category subject-to-BART. BART requireme nts for the taconite sources are shown in Tables 9.6 and 9.7 for each visibility impairing pollutant.

The BART analysis conducted by the facilities for ea ch subject-to-BART source is listed in Appendix 9.2. BART for each subject-to-BART source was dete rmined by the state taking into account the required72 factors. However, determining BART for the pellet furn aces at Minnesota’s taconite plants is more difficult than for EGUs or other, more common, types of equipment.

Eight taconite plants exist nationally: six in Minnesota and two in Michigan. The first new taconite plant to be built in over 30 years is not scheduled to begin operation until 2010. The lack of new taconite plants and retrofit projects at existing plants as well as the uniqueness of the industr y and the individual facilities (see Table 9.5) means that very few add-on control strate gies are known to be feas ible for taconite pellet furnaces. Even fewer control strategies are known to be cost-effective or otherwise reasonable.

Table 9.5: Characteristics of Minnesota Taconite Pellet Furnaces 57

Plant (line) Pelletizer type Pellet type Pellets fired, Long ton/hr Fuel Existing Control Keetac Grate Kiln Standard 600-660 PRB 58 coal-NG Wet scrubber a Hibbing Taconite 1 Straight Grate Standard 250-380 NG Wet scrubber 2 Straight Grate Standard 250-380 NG Wet scrubber 3 Straight Grate Standard 250-380 NG Wet scrubber Minntac b
3 Grate Kiln Standard 200-250 NG Wet scrubber a 4 Grate Kiln Flux/standard 400-450 60%wood-40% NG Wet scrubber 5 Grate Kiln Flux/standard 400-450 60%wood-40% NG Wet scrubber 6 Grate Kiln Flux 400-450 PRB coal-NG Wet scrubber 7 Grate Kiln Flux 400-450 PRB coal-NG Wet scrubber United Taconite c 1 Grate Kiln Standard 170-270 NG Wet scrubber 2 Grate Kiln Standard 480-550 Pet coke-coal Wet scrubber ArcelorMittal d Straight Grate Flux 310-440 NG Wet scrubber Northshore e
11 Straight Grate Standard 235-255 NG Wet-Wall ESP 12 Straight Grate Standard 235-255 NG Wet-Wall ESP

a Scrubber adds lime to enhance SO 2 removal
b Minntac can fire wood + NG in L3 through L7 but typically uses the fuels as shown above. Minntac can make standard or flux pellets in L3 through L7 but typically schedules production as shown above.

c United Taconite’s Line 2 is permitted to burn coal and petroleum coke with no coal type specified.
d ArcelorMittal can make standard pellets but typically does not; data comes from stack test results during flux pellet production.

e Northshore can make flux pellets in its furnaces without adding auxiliary burners in the preheat zone; pellet type is not seen in the stack test reports.

The MPCA has determined that BART for NO X for all taconite pellet furnaces is an operating standard of good combustion practices in combination with proce ss changes proposed as BART by the facilities, such as low-NO X burners in pre-heat zones, ported kilns, and modified furnace design for improved fuel efficiency.

BART for most direct PM emissions was determined to be equivalent to the taconite MACT, which requires control of PM emissions to control hazardous air pollutants. (Some PM emission sources are not covered by the taconite MACT.) Due to the MACT , the taconite facilities already have particulate control, with five facilities operati ng wet scrubbers and one wet-wall elect rostatic precipitators (ESPs). The taconite MACT establishes a PM 10 limit of 0.01 grains per dry standard cubic foot for the pellet furnaces at each of the six taconite plants.

57 Table 9.3.2 in Appendix 9.3 contains additional information.

58 PRB coal is Powder River Basin coal, which is generally low sulfur.73 BART for SO 2 for these units was generally determined to be the existing particulate scrubber optimized for SO 2 removal, as in most cases, a dd-on scrubbers were not cost-effec tive. The one exception is United Taconite’s Line 2. This line burns a combination of high sulfur fuels: petroleum coke and coal in varying blends with natural gas. MP CA has determined that the SO 2 BART limit for this line is 1.7 lbs/MMBtu, and believes that this limit can be met either through fuel blending, installation of an additional polishing scrubber, or a combination.

Due to the lack of emissions data representing the range of operating conditions that influence emissions and the inability to predict emissions using operating parameters, the MPCA is unable at this time to set an emission limit that corresponds to BART for SO 2 and NO X at most facilities, and it would be difficult to determine continuous compliance with a limit for most taconite pellet furnaces. In particular, the seeming variance of NO X emissions at all furnaces (similar to NO X variability at cement kilns) and SO 2 emissions at facilities that burn fuels other than natu ral gas prevents the MPCA from setting a meaningful BART emission limit at this time for those situations.

Therefore, the only specific BART limits that the MPCA has been able to include at this point are SO 2 emission limits for those taconite lines that burn low-sulf ur fuels, such as natural gas or biomass, as their primary fuel, and the SO 2 limit at United Taconite Line 2. The SO 2 limits will apply only when the lines are burning those primary fuels, not during the use of b ack up fuels, such as fuel oil. These backup fuels are subject to a general state limit and are not significant fuel sources for the facilities.

The MPCA believes that the scrubbers for lines bur ning low-sulfur fuels are already optimized for SO 2 removal. In general, the SO 2 limits are set using existing data and a 95% predictive interval. For lines that burn solid fuels, more data is needed to determin e if the PM scrubbers can be further optimized to improve SO 2 removal.

SO 2 BART emission limits, for these lines where sufficie nt information exists to establish a limit, are summarized in Table 9.6 and will be included in th e Title V operating permit for each source during the next re-opening of the permit, after EPA SIP approval.

The MPCA has issued Administrative Orders to each of the subject-to-BART taconite sources requiring the source to install Continuous Emissions Monitoring Systems (CEMs) or to demonstrate a comparable method of emission estimation, and to provide the MPCA with data from these new emission estimation methods. The MPCA anticipates that a year of data will be necessary in order to determine the remaining BART emission limits for the taconite facilities. 59

The comparable alternative method requires a mini mum of 150 one-hour data points collected under varying furnace conditions. Should emis sions be of low variability, the f acility is to develop an emission factor based on the process parameters. Frequent (ann ual or bi-annual) stack testing will be required, along with submission of quarterly parameters s howing continued operation of the furnace under the conditions tested. Should emissions be highly variab le, facilities must develop a predictive equation to correlate emissions with other pro cess parameters. The requirement fo r more accurate data collection through CEMs or a comparable alternative applies to NO X emissions at all the facilities and to SO 2 emissions at facilities burning high sulfur fuels. Th e MPCA will use the emissions and operating data gathered to establish BART limits and will include t hose limits in each facility’s Title V operating permit.

59 Due to economic conditions, many of the taconite lines ha ve not been operating over the past several months. This will impact when the MPCA is able to obtain of year of operation data. At this time, we believe many of the lines will be starting up during Fall 2009; thus, a full year of data should be obtained by the end of 2010 or early 2011.74 Administrative Orders by Consent were developed and signed between Septembe r 2007 and April 2009. US Steel signed Administrative Orders requiring CEMs for its two facilities, Minntac and Keetac. United Taconite has also signed an Order to install NO X CEMs and provide NO X data to the MPCA. 60 Hibbing Taconite, Northshore Mining, and Arcelor Mittal ha ve agreed to and signed Administrative Orders requiring the use of a comparable emission estima tion method for their facilities. These Orders are included in Appendix 9.7.

In weighing the five factors, MPCA has determined that BART does not result in the installation of any new controls or other additional work practice st andards or limits for the non-pellet furnace emission units primarily because the units are low emitters a nd thus have negligible impact on visibility.

The MPCA is unable at this time to quantify the de gree of emission reductions resulting from BART, but will do so in the Five Year SIP Assessment and revision.

BART Alternative In discussing BART with various facilities, it has come to the MPCA’s attention that some facilities with subject-to-BART sources may be considering project s that could result in greater overall emissions reductions than would be obtained through installation of BART.

In October 2006, EPA finalized a rule called Revisions to Provisions Governing Alternative to SourceSpecific Best Available Retrofit Technology (BART) Determinations

. 61 The preamble to this rule says,

“The Regional Haze Rule provides States w ith the authority to implement...alternative measures in lieu of meeting the requireme nts for source-by-source BART. Under this provision of the Regional Haze Rule, States have the flexibility to design programs to reduce emissions from stationary sources in a more cost-effective manner so long as they can demonstrate that the alternative appro ach will achieve greater reasonable progress towards improving visibility than would have been achieved by implementation of the BART requirements...[T]he emissions reduc tions that could be achieved through implementation of the BART provisions at s ection 51.308(e)(1) serve as the benchmark against which States can compare an alternative...” 62

The MPCA believes that certain voluntary projects at individual facilities could satisfy this BART alternative requirement, with the MPCA’s BART dete rmination serving as the benchmark that must be met or exceeded. Should emission reductions of SO 2 or NO X result from the proposed projects, the MPCA would evaluate these projects in comparison to the BART determinations to see if they result in greater control of visibility impairing polluta nts than would be expected under BART.

Due to questions raised during discussion of MPCA ’s BART determinations and the opportunity to propose an alternative, this section elaborates what the MPCA would consider as acceptable BART alternatives, subject to EPA approval of Minnesota ’s Regional Haze SIP a nd BART determinations.

60 Through a stipulation agreement, United Taconite has agreed to install NO X and SO 2 CEMS on both Line 1 and Line 2. CEMS at Line 2 were installed in January 2009 and must be certified by October 1, 2009; Line 1 has been shut down since November 2008, so the CEMS must be insta lled and certified by 60 days after the line is restarted.

61 71 FR 60612

62 71 FR 60614.75 A facility may choose to propose a BART alternative project. The BART alternative must result in equivalent or greater emissions re ductions and visibility benefits from the facility when compared to the MPCA’s BART determination.

Should a facility choose to propose a BART alternative, the proposal must include:

• A demonstration of equivalent or greater combined annual emission reductions of NO X and SO 2 (in tpy) than that established in this BART determination;

• Appropriate visibility modeling demonstrating equivalent or greater visibility protection than the MPCA’s BART determination; and

• A proposal for enforceable emission limitations, w ith appropriate and jus tified averaging periods and methods for evaluating compliance.

Since the facility would be proposing an alternative to MPCA’s BART determination, visibility modeling should follow the MPCA’s Guidance for Facilities Conducting a BART Analysis 63 and Best Available Retrofit Technology (BART) Modeli ng Protocol to Determine Sources Subject-to-BART in the State of Minnesota, 64 using the most recent versions of any model or EPA guidance referenced in those documents. The modeling should compare the baseline , pre-control scenario to post-control scenarios representing the MPCA’s BART determ ination and the BART alternative being proposed by the facility.

Facilities may propose a BART alternative that cove rs multiple BART units or both BART and nonBART units at the facility in the same source cate gory. A proposal coveri ng BART and non-BART units must demonstrate greater emission reductions and mo re visibility improvement from the facility than MPCA’s BART determination.

The MPCA would evaluate the BART alternative pr oposal, consult with the Fe deral Land Managers and Tribes, and determine if it is an acceptable BART alte rnative. If the project is deemed to result in equivalent or greater pollution control than BART, th e MPCA may determine that the proposed project is equivalent to BART. The resulting emission limits w ould then substitute for the BART emission limits. Ultimately, EPA approval of an enforceable docum ent (such as a Title V permit) containing BART emission limits will be necessary.

BART Implementation Minnesota is requiring that each subject-to-BART source, whether EGU or taconite facility, to install and operate BART as expeditiously as pr acticable but in no event later than five years after approval of the SIP or plan revision by EPA. Although at this time the exact BART emission limits for all the taconite furnaces have yet to be determined, BART implem entation and compliance will still occur within the required five-year time frame.

The MPCA has an established procedure, approved by EPA Region 5, for including SIP conditions in Title V permits. The permits then become joint T itle I/Title V documents, a nd any conditions imposed on the individual facilities to meet SIP requirements are cited as “Title I Condition: SIP for <pollutant>.” Title I conditions in Minnesota permits never expire.

Whether the final BART is good combustion practi ces measured by CEMs or more accurate emission measurements, or if another project that provides gr eater emission reductions is chosen to substitute for BART, any resulting emissions limits will be placed in the facility’s Title V permit. The MPCA is likely to include BART limits in Title V permits with the citation “Title I Condition: SI P for Regional Haze.”

63 http://www.pca.state.mn.us/publications/aq-sip2-09.pdf

64 http://www.pca.state.mn.us/publications/aq-sip2-05.pdf76 The Title V operating permits also will include a requ irement that each source maintain any necessary control equipment and establish procedures to ensure such equipment is properly operated and maintained. Minnesota intends to include these Title V operating permits in the Five Year SIP Assessment and revision.77Table 9.6: SO2BART Determinations for Units Where a Full BART Analysis Was ConductedFacility NameIDTitle V Permit #EmissionUnit #EmissionUnitDescriptionSO2BaselineEmissionsUsed in CostAnalysis(tpy)Capacity65BaselineControlsSO2Max. 24-Hr ActualEmissionsReported(lb/day)BART BARTEmissionLimit(30-day rollingaverage)Schedule of ComplianceKeetac2713700063# 13700063-003EU030PelletFurnace950.5 93%Recirculatinglime scrubberfor PM/SO2control9600Existing (2005)recirculatinglime scrubberTBD after gatheringemissions/ scrubberparameter dataAdministrative Order requiresinstallation of SO2 CEMs by Nov.30, 2008Hibbing Taconite2713700061#13700061-002EU020PelletFurnaceLine 1202.2 93%Wet scrubberfor PM control720Existing PMwet scrubber0.207 lb SO2/long tonpellet firedLimit to be incorporated into Title Voperating permit after EPA approvalof Regional Haze SIP as permit isreopened or amendedEU021PelletFurnaceLine 2179.5 93%Wet scrubberfor PM control912Existing PMwet scrubber0.207 lb SO2/long tonpellet firedLimit to be incorporated into Title Voperating permit after EPA approvalof Regional Haze SIP as permit isreopened or amendedEU022PelletFurnaceLine 3188.1 93%Wet scrubberfor PM control1,032Existing PMwet scrubber0.207 lb SO2/long tonpellet firedLimit to be incorporated into Title Voperating permit after EPA approvalof Regional Haze SIP as permit isreopened or amendedMinntac2713700005#13700005-002EU223 Line 3 329.3 93%Recirculatingscrubber2366Existingrecirculatingscrubber(installed 2006)116 lbs SO2/hourLimit to be incorporated into Title Voperating permit after EPA approvalof Regional Haze SIP as permit isreopened or amendedEU259 Line 4 447.5 93%Wet scrubberfor PM control3511Existing wetscrubber180 lbs SO2/hourLimit to be incorporated into Title Voperating permit after EPA approvalof Regional Haze SIP as permit isreopened or amendedEU280 Line 5 447.5 93%Wet scrubberfor PM control3511Existing wetscrubber180 lbs SO2/hourLimit to be incorporated into Title Voperating permit after EPA approvalof Regional Haze SIP as permit isreopened or amendedEU313 Line 6 544.8 93%Wet scrubberfor PM control4435Existing wetscrubberTBD after gatheringemissions/ scrubberparameter dataAdministrative Order requiresinstallation of SO2CEMs by Nov. 30,200865Capacity figures comes from expected capacity utilization described in the facilities’ BART analyses.78Facility NameIDTitle V Permit #EmissionUnit #EmissionUnitDescriptionSO2BaselineEmissionsUsed in CostAnalysis(tpy)Capacity65BaselineControlsSO2Max. 24-Hr ActualEmissionsReported(lb/day)BART BARTEmissionLimit(30-day rollingaverage)Schedule of ComplianceEU332 Line 7 544.8 93%Wet scrubberfor PM control4435Existing wetscrubberTBD after gatheringemissions/ scrubberparameter dataAdministrative Order requiresinstallation of SO2CEMs by Nov. 30,2008United Taconite2713700113#13700113-004EU040 Line 1 13.9 93%Wet scrubberfor PM control100.8Existing wetscrubber0.121 lb SO2/long tonpellet firedCertification of SO2CEMs 60 daysafter Line 2 CEMs certification. Limitto be incorporated into Title Voperating permit at time NOXlimit isestablished.EU042 Line 2 2749.7 93%Wet scrubberfor PM control15,173 Fuel blending 1.7 lbs/MMBtuCertification of SO2CEMs by June1, 2010. Limit to be incorporated intoTitle V operating permit after EPAapproval of Regional Haze SIP aspermit is reopened or amendedArcelorMittal2713700062#13700062-002EU026PelletfurnaceSV01444.8 93%Wet scrubberfor PM control3000Existing wetscrubber0.165 lb SO2/long tonpellet firedFacility has onefurnace with fourstacks; the emissionlimit is based on thesum of emissions fromall four stacks.Limit to be incorporated into Title Voperating permit after EPA approvalof Regional Haze SIP as permit isreopened or amendedEU026PelletfurnaceSV01544.8 93%Wet scrubberfor PM control3000Existing wetscrubberEU026PelletfurnaceSV01644.8 93%Wet scrubberfor PM control3000Existing wetscrubberEU026PelletfurnaceSV01744.8 93%Wet scrubberfor PM control3000Existing wetscrubberNorthshoreMining2707500003#07500003-004EU003ProcessBoiler #173.4100%(0% in pastpractice)Permit allowsonly NG/distillate fuelburned403.8No additionalcontrolNone needed None needed.EU004ProcessBoiler #273.4100%(0% in pastpractice)Permit allowsonly NG/distillate fuelburned403.8No additionalcontrolNone needed None needed.79Facility NameIDTitle V Permit #EmissionUnit #EmissionUnitDescriptionSO2BaselineEmissionsUsed in CostAnalysis(tpy)Capacity65BaselineControlsSO2Max. 24-Hr ActualEmissionsReported(lb/day)BART BARTEmissionLimit(30-day rollingaverage)Schedule of ComplianceNorthshoreMining2707500003# 07500003-004EU100Furnace 11HoodExhaust28.6 93%Wet-Wall ESPfor PM control852Existing wet-wall ESP0.0651 lb SO2/long tonpellet fired forEU100/EU104combinedLimit to be incorporated into Title Voperating permit after EPA approvalof Regional Haze SIP as permit isreopened or amendedEU104Furnace 11Waste Gas9.6 93%Wet-Wall ESPfor PM control283.2Existing wet-wall ESP0.0651 lb SO2/long tonpellet fired forEU100/EU104combinedLimit to be incorporated into Title Voperating permit after EPA approvalof Regional Haze SIP or as soon aspermit is reopened or amendedEU110Furnace 12HoodExhaust26.3 93%Wet-Wall ESPfor PM control852Existing wet-wall ESP0.0651 lb SO2/long tonpellet fired for EU110/EU114 combinedLimit to be incorporated into Title Voperating permit after EPA approvalof Regional Haze SIP or as soon aspermit is reopened or amendedEU114Furnace 12Waste Gas8.8 93%Wet-Wall ESPfor PM control283.2Existing wet-wall ESP0.0651 lb SO2/long tonpellet fired for EU110/EU114 combinedLimit to be incorporated into Title Voperating permit after EPA approvalof Regional Haze SIP or as soon aspermit is reopened or amended80Table 9.7: NOXBART Determinations for Units Where a Full BART Analysis Was ConductedFacility NameIDTitle V Permit #EmissionUnitNumberEmissionUnitDescriptionNOx BaselineEmissionsUsed in CostAnalysis(tpy)Capacity66BaselineControlsNOx Max. 24-hr ActualEmissionsReported(lb/day)BARTBARTEmissionLimit(30-day rollingaverage)Schedule of ComplianceKeetac2713700063#13700063-003EU030PelletFurnace4154 93% None 33,520Good combustionpractices, fuelblendingTBD after gatheringsufficient emissionsdataAdministrative Order requiresinstallation of NOx CEMs by Nov.30, 2008Hibbing Taconite2713700061#13700061- 002EU020PelletFurnaceLine 12497.7 93% None 13,392Good combustionpractices, furnaceenergy efficiencyproject made in2006TBD after gatheringsufficient emissionsdataDelineated in Administrative Order;installation of stack gas flowmonitors required 60 days after linerestart (estimated as January2010)EU021PelletFurnaceLine 22143.5 93% None 11,112Good combustionpractices, furnaceenergy efficiencyproject made in2006TBD after gatheringsufficient emissionsdataDelineated in Administrative Order;installation of stack gas flowmonitors required by March 1,2010.EU022PelletFurnaceLine 32247.1 93% None 12,624Good combustionpractices, furnaceenergy efficiencyproject made in2007TBD after gatheringsufficient emissionsdataDelineated in Administrative Order;installation of stack gas flowmonitors required 60 days after linerestart (estimated as January2010)Minntac2713700005# 13700005-002EU223 Line 3 1345 93% None 21,046Good combustionpractices, fuelblendingTBD after gatheringsufficient emissionsdataAdministrative Order requiresinstallation of NOx CEMs by Nov.30, 2008EU259 Line 4 1812 93% None 32,472Good combustionpractices, fuelblending, low NOXburners in pre-heatzoneTBD after gatheringsufficient emissionsdataAdministrative Order requiresinstallation of NOx CEMs by Nov.30, 2008EU280 Line 5 1820 93% None 32,472Good combustionpractices, fuelblending, low NOXburners in pre-heatzoneTBD after gatheringsufficient emissionsdataAdministrative Order requiresinstallation of NOx CEMs by Nov.30, 200866Capacity figures comes from expected capacity utilization described in the facilities’ BART analyses.81Facility NameIDTitle V Permit #EmissionUnitNumberEmissionUnitDescriptionNOx BaselineEmissionsUsed in CostAnalysis(tpy)Capacity66BaselineControlsNOx Max. 24-hr ActualEmissionsReported(lb/day)BARTBARTEmissionLimit(30-day rollingaverage)Schedule of ComplianceEU313 Line 6 1776 93% None 28,855Good combustionpractices, fuelblending, low NOXburners in pre-heatzoneTBD after gatheringsufficient emissionsdataAdministrative Order requiresinstallation of NOx CEMs by Nov.30, 2008EU332 Line 7 1928 93% None 28,855Good combustionpractices, fuelblending, low NOXburners in pre-heatzoneTBD after gatheringsufficient emissionsdataAdministrative Order requiresinstallation of NOx CEMs by Nov.30, 2008United Taconite2713700113#13700113-004EU040 Line 1 2151 93% None 15,631Good combustionpractices, pastheat recuperationprojectTBD after gatheringsufficient emissionsdataCEMs installation and certificationrequired 60 days after CEMscertification on Line 2.EU042 Line 2 1633 93% None 9,005Good combustionpractices, fuelblending; furtherevaluation ofPorted Kilnsneeded.TBD after gatheringsufficient emissionsdataCEMs certification by June 1,2010.ArcelorMittal2713700062#13700062-002EU026PelletfurnaceSV014369.6 93%None3730Good combustionpractices andfurnace energyefficiency projectcompleted in fall’07, low NOXburner in furnacepre-heat zone.TBD after gatheringsufficient emissionsdata.Administrative Order requiressubmittal of an alternative emissionmeasurement method (comparableto CEMs) by March 1, 2009.EU026PelletfurnaceSV015669 93% 4800EU026PelletfurnaceSV0161031 93% 7399EU026PelletfurnaceSV0171419 93%10,183NorthshoreMiningEU003ProcessBoiler #1(back-up)50.9100%(0% in pastpractice)None 278.4No additionalcontrolNone needed None needed.82Facility NameIDTitle V Permit #EmissionUnitNumberEmissionUnitDescriptionNOx BaselineEmissionsUsed in CostAnalysis(tpy)Capacity66BaselineControlsNOx Max. 24-hr ActualEmissionsReported(lb/day)BARTBARTEmissionLimit(30-day rollingaverage)Schedule of Compliance2707500003# 07500003-004EU004ProcessBoiler #2(back-up)50.9100%(0% in pastpractice)None 278.4No additionalcontrolNone needed None needed.EU100Furnace 11HoodExhaust112.4 93% None 1231.2Good combustionpracticesTBD after gatheringsufficient emissionsdataAdministrative Order requiressubmittal of an alternative emissionmeasurement method (comparableto CEMs) by June 30, 2008EU104Furnace 11Waste Gas273.7 93% None 2995.2Good combustionpracticesTBD after gatheringsufficient emissionsdataAdministrative Order requiressubmittal of an alternative emissionmeasurement method (comparableto CEMs) by June 30, 2008EU110Furnace 12HoodExhaust109.9 93% None 1231.2Good combustionpracticesTBD after gatheringsufficient emissionsdataAdministrative Order requiressubmittal of an alternative emissionmeasurement method (comparableto CEMs) by June 30, 2008EU114Furnace 12Waste Gas267.7 93% None 2995.2Good combustionpracticesTBD after gatheringsufficient emissionsdataAdministrative Order requiressubmittal of an alternative emissionmeasurement method (comparableto CEMs) by June 30, 200883 

### Chapter 10. Reasonable Progress Goals and Long-Term Strategy

The requirements of 40 CFR 51.308(d)(1) call for Mi nnesota to establish a Reasonable Progress Goal (RPG) for each Class I area within the state. The RPG, expressed in deciviews, ensures the state is making progress towards achieving natural visibility. Over the SIP period, the goals must provide for improvement in visibility over the most impaired da ys, and ensure no degradation in visibility over the least impaired days. The state must also provide an assessment of when the Class I areas would attain natural visibility conditions if improvement con tinues at the rate represented by the RPG.

In addition, 40 CFR 51.308(d)(3) requires states to s ubmit a long-term strategy (LTS) addressing regional haze for each mandatory Class I area which may be affect ed by emissions from within the state. The LTS must include enforceable emissions limitations, comp liance schedules and other measures necessary to achieve the RPG established by the state in which th e Class I area is located for both best and worst visibility days.

This chapter contains Minnesota’s long-term stra tegy for implementing all known reasonable control measures in order to ensure the RPG is met at a ll Class I areas to which Minnesota’s emissions are a significant contributor to visibility impairment. It also includes the reasonable progress goals established by Minnesota for BWCAW and VNP.

Consultation
Minnesota must consult with other states and trib es to set the RPG and develop coordinated emission strategies for meeting the established RPG. Th is requirement applies both where emissions from Minnesota are reasonably anticipated to contribute to visibility impairment in Class I areas outside the state and where emissions from other states and tribes are reasonably anticipated to contribute to visibility impairment in Minnesota’s Class I areas.

Minnesota consulted with other stat es and tribes in several ways, in cluding participation in CENRAP and the Northern Class I consultation processes, in orde r to develop the technical information necessary for determining where each state’s emissions are re asonably anticipated to contribute to visibility impairment, as well as information about the URP, implementation of coordinated emission strategies, and the RPG. These consultation processes are documen ted in Chapter 3. The state’s coordination with FLMs is described in Chapter 4.

Basis for emission reduction obligations Minnesota is required to demonstrate that its impl ementation plan includes all measures necessary to obtain its fair share of emission reductions needed to meet reasonable progress goals at all Class I areas where visibility is impacted by emissions from Minnesota sources (40 CFR 51.308(d)(3)(ii)). Determining that fair share of emission reduction re quires knowledge of which Class I areas are most impacted by emissions from Minnesota, and which states’ emissions most impact visibility in Minnesota’s Class I areas. This section documents the technical basis for Minnesota’s apportionment of emission reductions, both to meet the RPG in Minnesota ’s Class I areas and to meet the RPG in any Class I area impacted by Minnesota emissions.

Minnesota relied in part on technical analyses deve loped by MRPO and CENRAP to demonstrate that the state’s emission reductions, when coordinated with th ose of other states, are sufficient to achieve all reasonable progress goals. In cooperation with the Northern Class I consultation group and using the aforementioned technical analyses, as well as anal yses and modeling done in-house, the MPCA went through the following steps to determine Minnesota’s contribution to visibility impairment at various84 Class I areas, which forms the basis for Minnesota’s emission reduction obligations. (Documentation of the various steps is in the listed appendices.)

Baseline inventory Minnesota assessed the RPG and developed its long-t erm strategy using emissi on inventories developed by MRPO, with some Minnesota specific changes. 67 See Chapter 8 for further information.

Minnesota’s Impact on Class I areas Minnesota is reasonably anticipated to significantly cont ribute to visibility impairment at three of the four Northern Class I areas: BWCAW, VNP, and Isle Roya le. Initial modeling and da ta analysis studies done by MRPO showed that Minnesota was expected to contribute 30 – 35% of the visibility impairment affecting its own Class I areas in 2018, and about 14% of the visibility impairment affecting Isle Royale. Using the MPCA’s determination that a significant cont ribution to visibility impairment is a contribution over five percent on the worst days, Minnesota is not expected to significantly contribute to visibility impairment at any other Class I areas. Although Minne sota contributes five percent to overall visibility impairment at the fourth Northern Class I area, Se ney Wilderness, Minnesota’s contribution on the worst visibility days is below the five percent thre shold and therefore is not further discussed.

Minnesota’s own modeling analysis, described in Chapte r 8, supports the conclu sions drawn in the initial modeling and data analysis done by MRPO. Ba sed on the MPCA’s modeling, Minnesota has the following contributions to light extinction in 2018 at BWCAW, VNP, and Isle Royale:
Table 10.1: Class I areas Impacted by Minnesota

Class I area Minnesota Contribution to Light Extinction 68 in 2018 BWCAW 28%

VNP 31% Isle Royale 13%

CENRAP constructed Areas of Influence (AOIs) for each of its Class I areas, showing the important upwind source areas for emissions of precursors to vi sibility impairing pollutants. The AOIs show that Minnesota is in the Level 1 AOI (the AOI with the mo st impact) for the two Minnesota Class I areas, with small areas of the state in the Level 1 AOI for nitrate for the Class I areas in Missouri and Arkansas and in the sulfate and nitrate AOIs for the Cl ass I areas in North and South Dakota. 69 However, CENRAP’s PSAT analysis indicates Minnesota is not a signifi cant contributor to these Class I areas, based on MPCA’s chosen five percent th reshold. (See Appendix 10.1)

Oklahoma identified Minnesota as a state that contri butes to visibility impairment in the Wichita Mountains Class I area, using CENRAP’s PSAT anal ysis and a threshold of one inverse megameter contribution in 2018. However, Oklahoma did not identify any particular control measures that Minnesota was expected to undertake, due to the fact that Minnesota’s contribution was equivalent to the threshold level.

The contribution assessment performed by North east States for Coordinated Air Use Management (NESCAUM) for the Mid-Atlantic/Northeast Vi sibility Union (MANE-VU) shows Minnesota contributing less than one percent of the sulfate impa ct at the Mid-Atlantic and Northeast Class I areas. 70

67 MRPO, 2006.

68 This shows only light extinction resulting from nitrate, sulfate, and ammonium.

69 Stella, G.M et al., 2006.

70 NESCAUM, 2006.85 CENRAP’s PSAT analysis shows that Minnesota contri butes less than 3.5% of modeled light extinction to the MANE-VU Class I areas on the 20% worst days in 2018. Minnesota was not identified by MANEVU as a state impacting its Class I areas. 71

Back trajectory analysis by the Visibility Improvement State and Tribal Association of the Southeast (VISTAS) shows that some air masses impacting vari ous Class I areas in Virginia, North Carolina, and Florida may have had some residence time over Mi nnesota, but it does not appe ar substantial enough to make Minnesota a significant contributor to those Class I areas. 72 CENRAP’s PSAT analysis shows that Minnesota contributes less than two percent of mode led light extinction to the VISTAS Class I areas on the 20% worst days in 2018. (See Appendix 10.1).

No states other than Michigan and Oklahoma have, at this time, formally asked Minnesota to consult with them as a significant contributor to visibility impair ment at their Class I areas. Neither state has asked Minnesota to undertake specific emission reductions.

Because Minnesota is the major contributor to its ow n Class I areas, the MPCA believes that the measures undertaken to reach the RPG set for BWCAW and VNP will be sufficient to account for its share of emission reductions needed to meet the RPG at an y other Class I areas that Minnesota may impact, particularly Isle Royale.

States Impacting Minnesota’s Class I areas Minnesota identified the states expected to contribute significantly to visibility degradation, defined as more than five percent of visibility impairment on the worst days, in both VNP and BWCAW using the MRPO’s initial 2018 PSAT analysis, without later modifications (i.e., inclusion of IPM version 3.0 for EGUs.). Based on this information, the states iden tified as contributing to visibility impairment in Minnesota’s Class I areas are: Minnesota, Wisconsin , Illinois, Iowa, Missouri, and North Dakota. Appendix 3.2, containing Minnesota’s consultation letter, gives further information and shows that other analyses by MRPO and CENRAP support the determination of the contributing states.

Subsequent analyses by Minnesota, using in-house m odeling, show that the impacts of the contributing states on BWCAW, VNP, and Isle Royale are as follows:
Table 10.2: Percentage Contributions by State to Light Extinction 73

BWCAW VNP Isle Royale 74

Minnesota 28% 31% 13% Wisconsin 10% 6% 16% Illinois 6% 3% 8% Iowa 8% 7% 8% Missouri 6% 4% 5% North Dakota 6% 13% 4%

Further information can be found in Appendices 3.1, 3.2 and 10.1, Chapter 8, and the Technical Support Document.

71 MANE-VU, Inter-RPO Consultation Briefing Book . (webpage)

72 VISTAS. Summary Materials: Summary Presentations for each Class I area . (webpage)

73 Again, this shown only light extinction resulting from sulfate, nitrate, and ammonium.

74 This indicates contributions shown at the western tip of the island of Isle Royale, which is closest to Minnesota, not the IMPROVE monitor location, which is on the mainland.86 Pollutants and Sources Impacting Minnesota’s Class I areas The pollutants predicted to contribute most to visib ility impairment in each Class I area on the 20% worst days, both in the baseline period and in 2018, are sulfate, nitrate, and primary organic carbon. (See Figure 10.3.) MPCA chose to focus on sulfate and nitrate, as primary organic carbon appears to be at levels close to those estimated as na tural condition levels and is a smalle r contributor to light extinction. Also, the main sources of organic carbon seen in the Northern Class I areas are primarily biogenic in origin. Organic carbon is treated further in the sec tion on fires and smoke emissions. More information on visibility impairing pollutants can be found in Appendices 3.1, 10.1, Chapter 8 and the TSD.
Figure 10.3: 2002 Observations and 2018 Projections in Extinction by Species W20% Days

BWCAW VNP

MPCA also identified the major sources of the polluta nts likely to contribute to visibility degradation in each Class I area in 2018. Figure 10.4 documents the major sources of NO X and SO 2 emissions (in tons per year) in 2002 and 2018. Point sources are clearly a key source of emissions.
Figure 10.4: NO X and SO 2 Emissions in Minnesota by Source Category 0 10 20 30 40 50 60 70 80

Observed Projected 2018

AverageExtinction (Mm-1) CM
CRUSTAL
EC
OC
NO3
SO4

0 100000 200000 300000 400000 500000 600000

2002 2018 2002 2018

YearEmissions (tpy) Point Biogenics
Area
Non-Road
Mobile NO X SO 2 0 10 20 30 40 50 60 70 80

Observed Projected 2018

AverageExtinction (Mm-1) CM
CRUSTAL
EC
OC
NO3
SO487 Figures 10.5 and 10.6 show the main source categorie s contributing to light extinction from sulfate, nitrate, and ammonium in BWCAW and VNP. The major contributing sources in 2018 are projected to be EGUs. EGUs remain a large percentage contributor in 2018, as they were in 2002, partially due to major projected reductions in nonroad and onroad emissions. More information can be found in Appendices 3.1 and 10.1, along with Chapter 8 and the TSD.

Figure 10.5: BWCAW 2018 Extinction by Sector for each Specie, W20% Days

Figure 10.6: VNP 2018 Extinction by Sector for each Specie, W20% Days

These figures, along with Chapter 8 and the mode ling TSD, document the anthropogenic sources of visibility impairment considered by the state in de veloping its long-term stra tegy, as required by 40 CFR 51.308(d)(3)(iv). More detailed discussion of the pollutants and source categories considered can be found in Chapter 8. 0 2 4 6 8 10 12 14 16 18 20 22

PSO4 PNO3 PNH4 ASOA BSOAExtinction (Mm-1) EGU nonEGU Onroad Nonroad otherArea Ammonia BC ASOA BSOA

Total Extinction:
35 Mm -1

0 2 4 6 8 10 12 14 16 18 20 22

PSO4 PNO3 PNH4 BSOA ASOAExtinction (Mm-1) EGU nonEGU Onroad Nonroad otherArea Ammonia BC ASOA BSOA

Total Extinction:
34 Mm -188 Guidance in Determining RPG EPA released final guidance on June 1, 2007 to use in setting RPGs. 75 The EPA guidance states:
“RPGs are interim goals that represent increm ental visibility improvement over time toward the goal of natural background conditions an d are developed in consultation with other affected states and Federal Land Managers (F LMs). In determining what would constitute reasonable progress, section 169A(g) of the C AA requires states to consider the following four factors:

• The costs of compliance;

• The time necessary for compliance;

• The energy and non-air quality enviro nmental impacts of compliance; and

• The remaining useful life of existing sources that contribute to visibility impairment.
States must demonstrate in their SIPs how th ese factors are taken into consideration in selecting the RPG for each Class I area in th e state...As noted above, the RHR establishes an additional analytical requirement for states in the process of establishing the RPG. This analytical requirement requires states to dete rmine the rate of improvement in visibility needed to reach natural conditions by 2064, an d to set each RPG taking this ‘glidepath’ into account...EPA adopted this approach, in part, to ensure that states use a common analytical framework that accounts for the regional differe nce affecting visibility and, in part, to ensure an informed and equitable decision making process. The glidepath is not a presumptive target, and states may establish a RPG that provides for greater, lesser, or equivalent visibility improvement as that described by the glidepath.”

The glidepath named in the EPA guidance, also ca lled the “Uniform Rate of Progress” (URP) is essentially a line between current or baseline cond itions on the worst days and natural background in 2064. (See Chapter 5) The URP requires 0.12 deci views of improvement annually at VNP and 0.14 deciviews annually at BWCAW to meet natural condi tions by 2064. The tables in Chapter 5 give additional information about the observed visibility conditions.

Approach to Determining RPG 76 The following approach was used to determine the RPG for the four Northern Class I areas. It was developed by MRPO based on EPA’s draft guidance fo r setting reasonable progress goals, and agreed to by the states involved in the Northern Class I cons ultation process. By the time of the publication of EPA’s final reasonable progress guidance, the states in the Northern Class I consultation process were already acting based on the draft guidance, and Minnes ota did not feel that the changes to the guidance were substantive enough to warrant changes to the RPG approach.

The states involved in the Northern Class I consultati on process worked together to identify and prioritize sources, assess the impact of existing control programs on priority sources, and to direct a contract to investigate and evaluate control options for those priority sources. MPCA then followed this basic approach in setting the RPGs for Minnesota. The basi c steps for determining the RPG were as follows:

Identify and Prioritize Sources : The first step was to determine existing visibility conditions, examine which sources and geographic regions are contributing to worst and best visibility days, and, with the help of air quality models and monitoring receptor analys es, identify the major anthropogenic sources/sectors contributing to worst visibility days (priority sources) and their relative impacts on visibility impairment.

75 U.S. EPA, OAQPS, 2007b.

76 MRPO, 2005c.89 Overall, the states comprising the Northern Class I areas consultation group agreed that the priority emissions and sources were:

• SO 2 from point sources (EGUs and non-EGUs)

• NO X from point sources (EGUs and non-EGUs) and mobile sources

• NH 3 from agricultural operations

MPCA determined that the major pollutant and source impacting Minnesota’s Class I areas appears to be SO 2 from EGU, which forms ammonium sulfate. M odeling shows that sulfate is one of the main components of haze at VNP, BWCAW, and Isle Roya le on the 20% worst days. (See Appendix 3.1 and Chapter 8). EGU SO 2 emissions from Minnesota, Wisconsin, Io wa, North Dakota, Missouri and Illinois appear to be the key contributors. Ammonium nitrat e is also an important anthropogenic contributor to visibility impairment.

MPCA also identified the Northeastern corner of the st ate, the six counties closest to the Class I areas, as an important source area of SO 2 and NO X emissions. MPCA reviewed control strategy analyses done by CENRAP, which identified natural gas compressor sta tions and industrial, co mmercial and institutional (ICI) boilers as priority sources that should be ev aluated for potential control, and also identified potentially low cost control measures for multiple sources.

Identify Control Options for Priority Sources : The second step was to develop control options for reducing the emissions from the priority sources, incl uding existing and expected control programs (e.g., CAIR, BART, and nonattainment area controls) and ot her possible control programs. Minnesota worked in conjunction with MRPO to fund a contract to ex amine various control strategies. (See Appendix 10.5.)

On the books control measures examined were:

• Clean Air Interstate Rule

• BART

• MACT

o Reciprocal Internal Combustion Engines

o Industrial Boilers and Process Heaters

• On-Road Mobile Source Programs

o 2007 Highway Diesel Rule

o Tier II/Low Sulfur Gasoline

• Non-road mobile source programs

o Non-road Diesel Rule

o Control of Emissions from Unregulated Non-road Engines

• Locomotive/Marine

The other control options or scenarios examin ed, developed by MRPO, were the following:

• EGU control scenarios setting regional emission limits based on

o EGU1: SO 2 limits of 0.15 lbs/MMBtu NO X limits of 0.10 lbs/MMBtu

o EGU2: SO 2 limits of 0.10 lbs/MMBtu NO X limits of 0.07 lbs/MMBtu

• ICI Boilers

o ICI1: SO 2 reduction of 40% from 2018 baseline NO X reduction of 60% from 2018 baseline

o MRPO Workgroup Proposal resulting in a pproximately a 77% reduction in SO 2 and 70% in NO X .90 In Minnesota, the majority of the EGUs whose emissions significantly impact BWCAW and VNP are already undertaking controls and/or will be subject to BART limits. MPCA also identified the indurating furnaces used in taconite pellet pr oduction in Northeastern Minnesota as priority sources. These furnaces are subject to BART, but few emission reduction options for SO 2 or NO X have been investigated and are known to be reasonable.

Control options for various other sources were inve stigated in the EC/R report for MRPO and MPCA, shown in Appendix 10.5, and by Alpine Geophysics for CENRAP, shown in Appendix 10.6. This includes control measures and projected costs of c ontrol for natural gas compressor stations and ICI boilers and other sources identified by CENRAP. Ra ther than identifying specific emission limits for these sources, incremental control options (above an d beyond the 2018 base case) were identified and grouped by cost and emission reductions achieved. 77 See Appendix 10.6 for further information.

Finally, Minnesota identified control options for its priority sources in Northeastern Minnesota, as described later in this Chapter.

Assess Effect of Existing Programs for Priority Sources : The third step was to assess the expected emission reduction from existing control programs for th e priority sources, especially for the important visibility impairing pollutants (e.g., SO 2 and NO X ). Minnesota will obtain emission reductions from some of these priority sources under existing and on the bo oks programs. The impact of existing programs is described below, in the long-term strategy secti on on “Emission reductions due to ongoing air pollution programs.” In addition, the EC/R report describe s the expected emission reductions that will occur regionally from on the books controls for priority sources.

Evaluate Control Options for Priority Sources : Using the four statutory factors, the next step was to evaluate the control options for all priority sources and determine which measures may be reasonable.

Many control options for priority sources were eval uated in the report in Appendix 10.5. Particular attention was paid in the Northern Class I consulta tion group to the “EGU1” control strategy proposed by MRPO, which is a 0.15 lb/MMBtu SO 2 limit and a 0.10 lb/MMBtu NO X limit assumed to take effect in 2013. Many in the Northern Class I consultation group also believe it is important to take a look at ICI boilers, and the control strategies proposed by MR PO for those sources, including a 40% reduction in SO 2 limit and a 60% reduction NO X by 2013.

CENRAP evaluated control options for all sources that met the so-called Q/5D criteria, i.e. that their level of emissions (in tons) when divided by their distan ce (in kilometers) from an affected Class I area was less than or equal to five, and focused on control opt ions that were available for less than $5000/ton. CENRAP’s analysis indicates that, from sources m eeting the Q/5D and less than $5000/ton criteria, Minnesota could reduce 8192 tons of NO X emissions from the 2002 baseline at an average cost per ton between $2000 and $2500. This analysis did not find any SO 2 emission reductions available matching the specified criteria. Many of the NO X reductions were found at facilities that are already undertaking emission controls.

Because of the lack of known control options for taconite indurating furnaces , MPCA chose to include these sources in a regional approach to emission reduc tions, which is described as part of the long-term strategy. See “Plan for Emission Reductions in Northeast Minnesota.” Part of the goal of this plan is to spur the development of new control options.

77 Stella, February and March 2007.91 The states in the Northern Class I consultation proce ss have largely agreed on the priority pollutants (SO 2 and NO X ) and sources (EGU, and to a lesser extent ICI boilers), with each state adding some specific priority sources or source categories.

Compare Control Strategies with Uniform Rate of Progress : The final step was to compute the appropriate visibility metrics for the existing/expected controls and the “reasonable” controls for the Class I areas. Compare the expected improvement in visibi lity with the 60-year glidepath to natural conditions, and determine when areas would meet natural conditions if the annual progress under the RPG is less than the URP.

MPCA included in its long-term strategy all control measures currently believe d to be reasonable, and modeled these control strategies to determine if th e resulting visibility improvement was equivalent to, better, or worse than the URP. This is documented in the modeling chapter and will be described in more detail later, in the discussion of the RPG.

Share of Emission Reductions
Each state must obtain its share of emission reductio ns needed to attain the RPG. Between now and 2018, there will be reductio ns in emissions of SO 2 and NO X in Minnesota and the region impacting Minnesota’s Class I areas due to on the books control strategies, voluntary projects, and additional emission control measures. Many of these additional control strategies have been discussed by the Northern Class I consultation group. However, because of the differences in attainment status for criteria pollutants and contribution towards haze, each state mu st ultimately make its own decision as to which control measures are reasonable, there by impacting the reasonable progress goal.

Many of the states that contribute to visibility im pairment in Minnesota’s Class I areas are tackling multiple SIP issues at once (haze, PM 2.5 and ozone) and will submit their haze SIPs at a future date. Therefore, at this time Minnesota is establishing a RP G that might be exceeded due to the controls these states develop as they continue to work on their SIPs.

All of the control measures that Minnesota curren tly plans to undertake are included in the long-term strategy and described in the following section. Th e MPCA believes this contai ns all control measures currently known to be reasonable. Therefore, the RP G is set at the visibility level shown to result from the application of all the elements of Minnesota’s long-term strategy, along with all currently known controls being applied by other states.

The RPG is documented towards the end of this chap ter, after discussion of the long-term strategy. Minnesota believes that the state’s long-term strate gy when coordinated with other state and Tribes’ strategies will be sufficient to meet the reasonable progress goals set out below.

Minnesota’s Long-Term Strategy All of the control strategies that will contribute to meeting the RPG are documented in Minnesota’s longterm strategy. MPCA is required by 40 CFR 51.308(d )(3)(v) to consider several factors in developing its long-term regional haze strategy. These are discussed below.

Emission reductions due to ongoing air pollution programs 40 CFR 51.308(d)(3)(v)(A) requires Minnesota to co nsider emission reductions from ongoing pollution control programs. These emission reductions are reflected in the 2018 modeling inventory. Minnesota considered the following ongoing or expected programs in developing its long-term strategy:92 Clean Air Interstate Rule (CAIR) Minnesota’s electric generating utilities (EGU) were initially covered under the federal Clean Air Interstate Rule (CAIR), designed to reduce emissions of nitrogen oxides and sulfur dioxide. However, on May 12, 2009, EPA published a proposed rule to stay the effectiveness of CAIR in Minnesota, until EPA can determine if Minnesota meets the threshold for in clusion in the CAIR region. If finalized, Minnesota EGUs will not have to comply with CAIR until EP A’s repromulgated CAIR rule makes a final ruling on Minnesota’s inclusion. CAIR will continue to have an impact on visibility in Minnesota by reducing emissions in surrounding states.

The following table shows predictions of emissions from Midwest EGUs in 2018 using version 3.0 of EPA’s IPM modeling, which assumes that CAIR is implemented.

Table 10.3: IPM 3.0 Predictions for 2018

State Heat Input (MMBtu/year) SO 2 (tons/year) SO 2 (lb/MMBtu) NOx (tons/year) NOx (lb/MMBtu)

IL 1,310,188,544 277,33 7 0.423 70,378 0.107 IN 1,509,616,931 361,83 5 0.479 90,913 0.120 IA 534,824,314 115,938 0.434 59,994 0.224 MI 1,009,140,047 244,15 1 0.484 79,962 0.158 MN 447,645,758 61,739 0.276 41,550 0.186 MO 893,454,905 243,684 0.545 72,950 0.163 ND 342,685,501 41,149 0.240 44,164 0.258 SD 44,856,223 4,464 0.199 2,548 0.114 WI 675,863,447 127,930 0.379 56,526 0.167

Although Minnesota is likely to be removed from th e current CAIR program, the MPCA is aware of several facility-specific pollution control projects th at were being undertaken to ease compliance under CAIR; some of these projects will be required to fulf ill BART for specific units, others will go forward voluntarily.

Minnesota has also seen a number of voluntary project s being undertaken by EGUs to reduce emissions due to Minnesota statute 216B.1692, which makes the cost of environmental projects at existing large EGUs eligible for rate recovery. Projects completed or going forward under this statute are underlined in the following bulleted list. The statutory language is shown in Appendix 10.2. We believe that IPM 3.0 remains a relatively accurate portrayal of future EGU emissions in Minnesota, despite the potential change in CAIR status. See Chapter 8 for more information.

The MPCA has considered the following emission reductions in developing Minnesota’s long-term strategy; these projects have regulatory certainty as they are either already operating or have submitted applications to the Minnesota Public Utilities Commissi on for rate recovery or permit applications to the MPCA. 78 Appendix 10.3 contains details on how to access relevant Air Emission Permits for these projects.

The projects being undertaken to reduce NO X and/or SO 2 include:

• Minnesota Power, Boswell – Unit 3 – BACT-like NO X and SO 2 controls by 2009

• Minnesota Power, Laskin – Units 1,2 – NO X controls by 2009

78 For example, documents relating to Minnesota Power’s application for a emission reduction rider for pollution control projects at Laskin and Taconite Harbor can be fo und at https://www.edockets.sta te.mn.us/EFiling/search.jsp by searching for docket number 05-1678.93 • Minnesota Power, Taconite Harbor – Units 1,2,3 – NO X and SO 2 controls by 2009

• Ottertail Power, Hoot Lake – Units 2,3 – NO X controls by 2008

• Rochester Public Utilities, Silver Lake Plant – Unit 4 – NO X and SO 2 controls by 2009

• Xcel Energy, Allen S. King Plant – Unit 1 – NO X and SO 2 controls in 2007

• Xcel Energy, High Bridge – Units 3,4,5,6 – Switch from coal to natural gas by 2008

• Xcel Energy, Riverside – Units 6,7,8 – Switch from coal to natural gas by 2009

• Xcel Energy, Sherburne County – Units 1,2,3 – NO X and SO 2 reductions

Minnesota and the other states participating in the Nort hern Class I consultation calls believe that in some areas their future EGU emissions were not correctly represented by IPM 3.0, because certain planned reductions were not included. Therefore, these st ates constructed an IPM 3.0 “will do” scenario, representing EGU emissions with known projects included. In general, known projects are those that have already gone through some kind of regulatory pro cess, such as a permit application or notice to a state utility commission. However, the projects in the IPM “will do” scenario were not known in time to be submitted to EPA in order to be included in the base IPM3.0 projection.

In addition, a few mistakes were noticed in the IPM3 .0 predictions; examples of such errors affecting Minnesota facilities include the size of an E GU boiler being understated by 100MW and NO X emission rates being considerably lower than permit limits. Minnesota included these corrections in the “will do” scenario, resulting in a slight increase in predicted NO X emissions. Other states also included higher emissions where they felt IPM had inaccurately predicte d the 2018 scenario, such as where facilities were shown with controls although utilities had indicated to the state that they would not be installing controls. Overall, these corrections resulte d in higher regional emissions.

Table 8.5 shows the base and adjusted emissions, and Chapter 8 also discusses the adjustments made by the states participating in the Northern Class I consu ltation process. In some cases, states also provided a “may do” scenario, which includes EGU reductions that are possible but have not yet gone through enough procedures within the state to be sure that they will be undertaken. However, Minnesota did not rely on the “may do” scenario in any modeling or determination of the RPG. Therefore, the emissions from the “may do” scenario are not shown here, though they can be seen for the contributing states on page 12 of the consultation letter that is Appendix 3.2.

Best Available Retrofit Technology (BART) As documented in Chapter 9, Minnesota has severa l emission sources that are subject to BART. Minnesota has incorporated language into its rules making any standard or other requirement established under section 169A (Visibility Protection for Federal Class I areas) or 169B, including emission limits established in the determination of best available retrofit technology , “an applicable requirement for stationary sources.” (See Appendix 9.7)

As mentioned previously, MPCA has made BART de terminations for Minnesota’s subject to BART EGUs. However, as described in Chapter 9, determ ining BART for the pellet furnaces at Minnesota’s taconite facilities is difficult. MPCA has made BART determinations, but is unable at this time to set a corresponding BART emission limit for most of the pelle t furnaces. Therefore, at this time, we cannot predict the full extent of the emission reductions that will result from BART in Minnesota.

The MPCA is requiring the taconite facilities to c ontinuously monitor or use a comparable alternative method to obtain more accurate estimations of their emissions, and report their emission data to MPCA. It has been shown in the past that installation of co ntinuous monitors allows facilities to more efficiently monitor and manage their combustion processes, resulting in less fuel usage and fewer emissions. The94 MPCA expects this could result in emission reductions of 5 –30%, depending on the facility, simply due to combustion management.

After a year of emission data is obtained, MPCA will review the data and set necessary BART emission limits; these emission limits will be incorporated in to facility Title V permits. In the Five Year SIP review, the MPCA will document those emission limits and the level of reductions they represent from the 2002 base year emission inventory. For more information on BART, see Chapter 9.

The states surrounding Minnesota and the contributing states have made varying decisions about BART, resulting in a wide range of potential emission reductio ns due to BART. Chapter 8 and the TSD describe the emission reductions from BART in other states th at were incorporated into Minnesota’s modeling.

Other Federal Programs Minnesota also anticipates some significant emission reductions resulting from se veral federal rules that will be implemented in the next several years. These reductions were included in the modeling of predicted 2018 emissions.



### • Tier II for on-highway mobile sources



### • Heavy-duty diesel (2007) engine standards



### • Low sulfur fuel standards



### • Federal control programs for nonroad mobile sources

PM 2.5 and Ozone SIPs Minnesota is currently in attainment with the NAAQS for PM 2.5 and ozone, and therefore was not required to submit SIPs showing decreases in these polluta nts. However, several of the states that impact BWCAW and VNP are or will be submitting SIPs that include plans to reduce these pollutants and their precursors. These reductions will also reduce precurs ors to regional haze. Emission reductions included in SIPs from contributing states were not available in time to be included in this SIP. Minnesota has asked contributing states to provide information on em ission reductions as they complete their SIPs, so that Minnesota may include this information in fu ture modeling and the Five Year SIP Assessment.

Additional Emission limitations and schedules of compliance 40 CFR 51.308(d)(3)(v)(C) requires Minnesota to identif y additional measures to meet visibility goals when ongoing programs alone are not sufficient. It appears that ongoing air pollution control programs are not sufficient to meet the URP at Minnesota’s Class I areas, or at Isle Royale, to which Minnesota is a significant contributor, through 2018. Even if they were sufficient to meet the URP, the state is required to investigate other reasonable control strategies.

Certain voluntary emission reductions, not mentioned previously, appear likely to occur among Minnesota’s taconite industry. Based on this information, and know ledge of reductions occurring at EGUs, Minnesota adopted the following strategy as a “backstop,” ensuring that these planned reductions take place and providing incentives for other emissi on reductions. The strategy also ensures that Minnesota’s sources obtain their fair share of emission reductions and addresses concerns about industrial expansion near the BWCAW and VNP.

Plan for Emission Reductions in Northeast Minnesota
Minnesota’s Class I areas are located in the Northeastern region of the state. This area, sometimes known as the Arrowhead or Iron Range, contains some major industrial sources that are high emitters of the two main haze causing emissions – SO 2 and NO X . These high emitters (as of 2002) include EGUs and the95 taconite industry, a unique iron ore mining and pro cessing industry with only eight operating facilities in the nation, six of which are located in Northeast Minnesota.

In addition, several new sources are likely to open on the Iron Range in the next few years, adding to the emissions in the region. The combination of geogr aphic proximity, high existing emissions, and potential new sources has led to a high level of concern over the impact of this area on visibility. Therefore, in cooperation with the Federal Land Managers, Minnesota has develope d a plan that sets emission reduction targets in the six counties closest to VNP a nd the BWCAW. The concep t plan for Northeastern Minnesota, developed by MPCA and the FLMs and w ith extensive stakeholder input, is attached as Appendix 10.4. This section of the SIP focuses on implementation of the plan.

Large point sources located in St. Louis, Lake, C ook, Carlton, Itasca and Koochiching counties that emitted over 100 tons per year of either SO 2 or NO X in 2002, or have the potential to emit over 100 tons per year of either pollutant (if not in existence in 2002), will be subject to a region-wide target for emission reductions compared to the 2002 emission inventory.

The emission reduction target was derived from the URP line for Voyageurs National Park. Many RPOs and states have determined from technical analyses th at much of their visibility impairment is caused by sources beyond the state’s control – sources like organic carbon from wildfires, windblown dust, or international transport of emissions. In order to tr y to determine reasonable progress without the impact of non-controllable sources, “species-specific” glide slopes are created. This involves changing the deciview glide path to a glide path for light extinction, and then separating out the different types of particles based on how they contribute to the overall light extinction. Although Minnesota did not use this approach in calculating the RPG, it was us ed in developing the emission reduction target.

In order to focus solely on controllable impacts, the effects of emissions from outside Minnesota, emissions that are biogenic or otherwise difficult to co ntrol, and emissions that are at predicted natural conditions were removed. This resulted in 75% of all visibility impacts assumed to be uncontrollable by the MPCA. This left ammonium sulfate and ammonium nitrate from in-state sources; these particles are caused by SO 2 and NO X , pollutants with established methods of control. Calculations were done to determine the percent decrease in light extinction due to these particles needed to achieve the 2018 visibility goal, and the assumption made that the extinc tion coefficient changed in direct proportion to the change in emissions from the region. Since light extinction from these particles needs to decrease by about 28% to reach the glide path, the ultimate target was set as a 30% reduction in emissions. 79

In short, the emission reduction target is intended to reflect the level of reductions needed in ambient concentrations of sulfate and nitrate in order to meet the URP for those pollutants, adjusted for the level of emissions that are uncontrollable or outside the domain. 80

Based on this technical analysis, Minnesota is esta blishing an emission reduction target or goal of a reduction in combined SO 2 and NO X emissions from the subject sources of 20% by 2012 and 30% by 2018.

79 The MPCA would like to thank Scott Copeland of the CI RA/VIEWS Staff for his inva luable assistance in the technical work, such as deri ving the species-specific g lide path, needed to set the emission reduction target.
80 Note that changing the percentage of impacts found to be uncontrollable did not make a major difference in the percent reductions needed to meet the glide path. It should also be noted that the approach does not consider modeling of individual sources, but treats all emissions as tho ugh they have equal potential to cause impacts. It also does not explicitly account for differing mass extinction efficiencies of NO, NO2 and SO2.96 Although most of the largest sources in this re gion are subject to BART and many are undertaking voluntary emission reduction projects, this target ai ms for overall larger emission reductions than are otherwise likely. Table 10.4: NE Minnesota Emission Reduction Target

Year Total Emitted (tpy) 2002 – Combined SO 2 and NO X emissions 95,562 2012 Goal – 20% Reduction 76,450 2018 Goal – 30% Reduction 66,894

This area was targeted for controls under the long-term strategy for several reasons. First, the MPCA’s analysis of 2002 emissions from the top 18 emitting poi nt sources within Minnesota show that sources from this region make up just 1/3 of the total emissions but provide 2/3 of the total visibility impact. (See Chapter 8, on modeling.) Therefore, they have a mu ch larger impact on the Class I areas than emissions from farther away. In addition, the taconite fac ilities may be currently unc ontrolled or under-controlled for SO 2 or NO X, and on the books control strategies are project ed to cause fewer emission decreases in this region than in the remainder of the state.

The MPCA will track annual SO 2 and NO X emissions from all covered sources in the region, both actual emissions (as submitted to the emission inventory) from existing sources and potential emissions from new or modifying sources that have su bmitted complete permit applications.

Minor sources (<100 tpy) are not included in the No rtheast Minnesota plan, and their emissions will not be tracked annually. However, in 2012 and 2018, the MPCA will ev aluate the emissions from minor sources that hold individual or registration permits in order to determine how those emissions have changed from the 2002 baseline.

This tracking process will allow the MPCA to take a holistic look at the emission changes in the region, rather than simply addressing the largest sources th at individually contribute to visibility impairment.

The existing individual sources whos e emissions will be tracked are:

• Minnesota Power Inc - Boswell

• US Steel Corp - Minntac

• Hibbing Taconite Co

• US Steel - Keewatin Taconite

• Northshore Mining Co - Silver Bay

• Minnesota Power - Taconite Harbor

• United Taconite LLC - Fairlane Plant

• Minnesota Power Inc - Laskin

• Arcelor Mittal Mining Co

• Sappi Cloquet LLC

• Boise White Paper LLC - Intl Falls

• Virginia Dept of Public Utilities

• Duluth Steam Cooperative Assoc.

• Minnesota Power Inc - ML Hibbard

• Hibbing Public Utilities

• Blandin Paper/Rapids Energy Center

• Georgia-Pacific - Duluth Hardboard

• Ainsworth Engineered LLC-Cook

• Ainsworth Engineered LLC - GR97 The MPCA will make publicly available, most likel y electronically, an annual update of actual and forecasted emissions from the tracked sources in th e region, along with the most recent monitored visibility conditions available. 81 In addition, the MPCA will do a calculation of emissions in the region and progress towards the reduction target when any new major source applies for a permit to locate in this six-county region, or an existing source requests a ma jor modification that would require a PSD permit. This information will be shared with the FLMs for their review prior to permit issuance, and will be available as part of the public notice process prior to permit issuance.

MPCA is requiring CEMs or a comparable emission estimation method to be applied by the taconite facilities as part of BART. This will allow facilities to closely monitor future emissions. It may also provide information about the accuracy of the 2002 baseline emission levels; there is the potential for adjusting the baseline level from which emissions must be reduced in light of additional information. However, changes in fuel types and physical modifi cations to the taconite fu rnaces undertaken since 2002 make accurate emission comparisons challenging. Th ese changes are expected to result in decreased SO 2 and NO X emissions from the taconite industry as a whole. Because emissions from taconite facilities are believed to have made up 47% of the 2002 emissions from stationary sources in the six-county area, the MPCA will attempt to take the uncertainty about th e 2002 emissions into account when determining if additional emission reductions to meet the target are needed.

Based on the BART analyses, MPCA has determin ed that the six taconite facilities may be undercontrolled, and that very few emission contro l technologies are known to be effective for the industrial processes involved in tac onite production. Minnesota will th erefore require these facilities to investigate control technologies and pollution preven tion practices for their indurating furnaces through pilot tests or other mechanisms conducted on-site at the facilities, and report to MPCA on the feasibility and cost effectiveness of said technologies and practices.

These reports will likely be structured very much like the facilities’ BART analyses, evaluating the feasibility of implementing piloted technology at a larg e scale, the costs of installing controls, and other impacts. The MPCA will conduct a review of the ta conite facilities’ reports on the piloted control strategies and pollution prevention op tions investigated by the taconite facilities. We anticipate that the facility reports and MPCA’s subse quent analysis will be made avai lable for public review, through a similar process as used for the BART analyses.

The MPCA will evaluate the piloted potential contro l strategies using the statutory factors (cost of compliance, time necessary for compliance, energy and non-air environmental impacts, the source’s remaining useful life, and visibility impact) and considering the progress towards the overall emission target. That progress will become a sixth factor consid ered in determining what control strategies or level of emission reductions are reasonable. Also, the degree to which 2002 emissions were over or underestimated will be consider ed, at least qualitatively.

The MPCA believes that the pilot tests at existing f acilities and installation of emission control equipment at new taconite facilities will demonstrate that feasible, reasonable controls exist for the taconite facilities. Regardless of the status of the overall Northeast Mi nnesota emission target, such reasonable emission reduction measures will be required to be implemented as part of the state’s long-term strategy. The status of the emission target will be used primarily to inform the consideration of cost-effectiveness – if the overall regional emission reduction target is bei ng met, the maximum $/ton cost-effectiveness level considered to be reasonable would likely be lower. Should more reductions be needed to meet the emission target, then a higher $/ton figure may be considered reasonable.

81 The first annual tracking spreadsheet was po sted in January 2009 and is available at: http://www.pca.state.mn.us/publications/aq-sip2-11.pdf98 If it appears that other facilities will need to implem ent control strategies in order for the emission reduction target to be met, even after all voluntar y EGU reductions have occu rred and the determination of additional reasonable controls on the taconite facilities has been made, the MPCA will do a preliminary cost analysis of feasible pollution prevention and cont rol options to evaluate whether further analysis by the facilities is warranted. If needed, such analysis will be requested by the MPCA. This further analysis would be used to determine reasonable control strate gies that should be implemented by those sources. Reasonableness will be evaluated based on the same factors listed above.

Although the regulatory or enforceable mechanism that will be used to require these reasonable emission reductions is not yet known, the MPCA anticipates th at the determination of r easonable controls will be included in the Five Year SIP Assessment. Minnesota would likely implement the requirement for additional emission reduction measures, for both the taconite facilities and any other facilities where additional controls are found to be reasonable, through a “reasonable progress” requirement that would ultimately apply an emission limit to each facility wh ere additional controls have been found to be reasonable. This limit could be set through a state ru le or through amendments to each facility’s Title V air emission permit.

In cooperation with the FLMs, the MPCA has developed a strategy for reporting progress towards the emission reduction goals and for c onsulting with the FLMs to determ ine necessary additional actions. The reporting is designed to mesh with the requireme nts of the Five Year SIP assessment. In that assessment, the MPCA will compare actual emissions to the emission target and determine 1) if the 2012 target has been met and 2) if the 2018 target is lik ely to be met. Throughout the implementation period for this SIP, if it is projected that either target will not be met, the MPCA will consult with the FLMs, tribes and other stakeholders to determine what ac tions are needed to meet the 2018 target, taking into account the factors such as the difference between ac tual emissions and the target, plans for emission reductions between 2013 and 2018, the trends in nitrate and sulfate concentration and visibility in BWCAW and VNP, modeled visibility for 2018, and the availability of cost-effective emission reduction strategies. Actions could range from simply continued tracking to further assessment and potential implementation of additional emissi on reduction measures by facilities.

The following table lays out the relevant timelines for the interlinked components of BART and the LTS in Northeast Minnesota.

Table 10.5: BART and Northeast Minnesota Plan Timeline

Process Dates Begin data collection and reporting for taconite facilities with new CEMs/PEMS, as required by Administrative Orders November 2008

Begin annual tracking of NE Minnesota Plan emissions December 2008 MPCA determines remaining BART limits for each taconite facility By August 31, 2011 MPCA determines if 2012 target w ill be met, and projects status of 2018 emission reduction target. January – December 2012

Taconite facilities conduct pilot test ing of potential control strategies and pollution prevention July 2011 – December 2012

Taconite facilities report to MPCA on resu lts of pilot testing By March 1, 2013 MPCA reviews pilot testing reports and determines if any additional controls are reasonable March – June 2013

MPCA does preliminary analysis of potentially reasonable reductions from non-taconite facilities in NE Minnesota. January – June 2013

MPCA develops enforceable mechanism to require any additionalcontrol found to be feasible, for both taconite and (if necessary) nonJuly 2013 – June 201499 taconite facilities MPCA submits 5 year assessment which includes BART limits, determination of additional reasonable controls. July 2014

Facilities install any additional controls found to be reasonable 2015 and forward

It should be noted that the economic downturn has imp acted operations at the tac onite facilities. Although some data collection began in November 2008, the majo rity of the facilities have subsequently idled their operations. The deadlines in Table 10.5 have been re vised from the initial draft SIP to recognize that data collection is not likely to begin until lines resume ope ration, likely in fall of 2009 or early 2010, thereby impacting when the MPCA will be able to set BART limits and when facilities will be able to begin investigating potential controls.

Emissions from the six-county region covered by the Nort heast Minnesota plan will continue to be held to a level 30% below 2002 levels beyond 2018. In future SIP revisions, the MPCA will consult with the FLMs and evaluate the necessity of maintaining emissions from Northeast Minnesota at this level and the possibility of continuing reductions from the area in order to reach the long-term visibility goals.

Measures to mitigate the impacts of construction activities 40 CFR 51.308(d)(3)(v)(B) requires Minnesota to co nsider measures to mitigate the impacts of construction activities. Some of the main impacts of construction activities include the impacts of emissions from nonroad mobile and diesel engines and fugitive emissions resulting from land clearing and construction. Emissions from nonroad mobile sour ces and diesel engines w ill be decreased between now and 2018 due to federal on the books control strategies.

The impact of construction activities will continue to be mitigated through the federal general and transportation conformity rules, which are included in to Minnesota’s SIP. In addition, Minnesota has a state rule, Minnesota Rule 7011.0150, which requires a ll reasonable measures to be undertaken to prevent particulate matter from becoming airborne. This rule is already included in Minnesota’s SIP.

7011.0150 PREVENTING PARTICULATE MATTER FROM BECOMING AIRBORNE.

No person shall cause or permit the handling, use, transporting, or storage of any material in a manner which may allow avoidable amounts of particulate matter to become airborne.

No person shall cause or permit a building or its appurtenances or a road, or a driveway, or an open area to be constructed, used, repaired, or demolished without applying all such reasonable measures as may be required to prevent particulate matter from becoming airborne. All persons shall take reasonable precautions to prevent the discharge of visible fugitive dust emissions beyond the lot line of the property on which the emissions originate. The commissioner may require such reasonable measures as may be necessary to prevent particulate matter from becoming airborne including, but not limited to, paving or frequent clearing of roads, driveways, and parking lots; application of dust-free surfaces; application of water; and the planting and maintenance of vegetative ground cover.100 Measures to mitigate the impacts of new sources
In terms of the construction of new major sources, the visibility impacts of such sources will continue to be managed in conformance with existing requirements pertaining to New Source Review and Prevention of Significant Deterioration, for which Minnesota operates a delegated PSD program. The PSD program requires the installation of BACT and modeling of th e project’s impacts on local air quality. New sources or major modifications outside the Northeast Minnesota Plan also need to screen their emissions. If they are judged to have a potential adverse impact on vi sibility, those projects will need to perform more sophisticated modeling and analysis of their proposed impacts on Class I areas, including their effects on visibility. 82

Sources covered by the Northeast Minnesota Plan th at propose PSD modifications for haze pollutants will have to install BACT and ensure that their emissions fit into the budget for the Plan. The PSD regulations also require the consideration of other impacts to the environment. The proximity of new and modified facilities to Minnesota’s Class I areas, even those c overed by the Plan, necessitates consideration of visibility in this step. (Historically, the MPCA has incorporated similar environmental factors into the BACT determination by adjusting the cost-effectivene ss threshold.) This can lead to the application of more effective control strategies and thus lower emission rates. In addition, the MPCA could cite the visibility section of the PSD rule in order to ask for controls. Through the PSD process, which includes review by and input from the Federal Land Managers, particularly on appropriate BACT determinations and determinations of adverse visibility impact, the MPCA will be able to minimize the impact of new sources on visibility.

The Northeast Minnesota plan attempts to move fro m the incremental approach of the traditional PSD visibility program towards a more holistic approach . If emissions are declining under the Northeast Minnesota Plan, visibility should be improving; this is a better approach than determining if simply the addition of pollutants will not have too great an impact on the Class I area.

For sources subject to the Northeast Minnesota plan described previously, the intent is for the MPCA to sign a Memorandum of Agreement with the FLMs that would not require new or modifying facilities in that Northeast Region to conduct a detailed visibility an alysis under PSD, as long as the region as a whole is meeting the stated emission reduction goals. Shoul d the Northeast region fail to meet the reduction goals, full visibility analysis would be required unde r the PSD program. Until the memorandum is signed, the MPCA will continue to require new or modify ing facilities to undertake a visibility analysis as needed.

Source retirement and replacement schedules Source retirement and replacement schedules, which must be considered under 40 CFR 51.308 (d)(3)(v)(D) in developing reasonable progress goals, will be managed in conformance with existing requirements under the PSD program, much as described above.

Agricultural and forestry smoke management Under the requirements of 40 CFR 51.308(d)(3)(v)(E ) Minnesota must consider smoke management techniques for the purposes of agricultural and forestry management in developing the long-term strategy to achieve the reasonable progress goal.

Impact of Fires on Visibility Vegetative burning produces NO X , organic compounds, carbon monoxide, carbon dioxide, and particulate matter. Approximately 90% of smoke partic les from wildland and prescribed fires are PM 10 , while about

82 This determination is generally ma de by the Federal Land Managers.101 70% are PM 2.5. 83 Of the pollutants that derive from vegetative burning, those that mainly impact visibility are nitrates, ozone, organic carbon (OC), and elementa l carbon (EC). Ozone, while not directly produced by fires, may form downwind of fires due to photochemical reactions of combustion products (NO X and VOCs). Ozone can also participate in nitrate and sulfate particle formation.

Of the main visibility impairing pollutants, OC and EC are formed from fire; however, neither are unique products of fire. EC, for example, is a primary product of the combustion of any carbon fuels, and therefore can come from diesel emissions as well as vegetative burning. Organic aerosols can be the outcome of either primary emissions or secondary formation from gas phase emissions. OC can be attributed to human sources of VOCs or to biogenic emissions from both conifer and broad-leaved trees in the summer growing season.

At both VNP and BWCAW, OC is the largest component of PM 2.5 mass measured in summer by the IMPROVE monitors. When light extinction is calculated from the filter measurements, OC is proportionally less significant but still an important pollu tant – roughly equal to sulfate in its effect on summertime visibility (Figure 10.3, Appendix 3.1.)

Both OC and EC are products of fire and monitoring data on days affected by fire will show increases in these pollutants. In general, biogenic emissions of OC are not easily distinguished from emissions from fire, 84 but several studies have been done to determine the causes of high OC in the Class I areas. It appears that most OC seen in the Northern Class I areas is biogenic, coming from plants as opposed to fire.

Sheesley and Schauer conducted a stud y at Seney Wilderness that examined the sources of organic carbon affecting the area. 85 Using a marker species associated with vegetative burning, they found the highest levels of this marker in the winter months, lik ely indicating burning due to use of wood stoves and fireplaces. There was a lesser peak from June throug h September; the summertime levels of the marker species indicate high secondary organic aerosols, not primary emissions of wood smoke or other sources. These findings were reviewed in a 2005 MRPO issue pa per, which concluded “the contribution of fires to annual average PM 2.5 concentrations and visibility impairment in the Upper Midwest is relatively small. Nevertheless, fires may cause problems on an episodic basis.” 86

To further investigate the impact of fire, a MRPO c ontractor developed an inventory of fire emissions from agricultural, prescribed, and wildfire burning in 2001 – 2003 for the Midwest states; the report shows that Minnesota has the greatest emissions of the eight states due to burning. 87 In addition, total acres burned by both wildfire and prescribed fire increased in each successive year, and total acres burned in Minnesota were usually more th an twice the next highest state. 88

Because of the relatively high levels of burning and the fact that prescribed burning is likely to continue to increase, it is important to assess the effects of fires in Minnesota on the visibility data, especially for the 20% worst days.

The following table identifies days among the worst 20% visibility days of the baseline period that have the highest levels of organic and elemental carbon.

83 EPA, 1998

84 Debell, et al., 2006.

85 Sheesley & Schauer, 2004.

86 MRPO, 2005a, p 9.

87 Boyer, et al, 2004. Table 8-2, p 67.

88 Boyer, et al, 2004. Table 8-3, p 70.102 Table 10.6: W20% Days with Highest OC and EC Light Extinction (Baseline Years) *

Class I

area Species 2000 2001 2002 2003 2004 Sept 30

NA June 1 June 28 July 19 June 5 Aug 7 Aug 25 July 17 July 26

BWCAW OC 26.64 NA 66.50 125.56 27.87 28.52** 55.67 71.68 34.36

EC 9.24 5.74 7.13 3.58 2.02 4.68 3.40 3.50

VNP OC 30.58 89.38 71.23 169.82 25. 56 32.05 57.51 80.58 44.83
EC 10.68 8.29 5.93 8.58 4. 86 3.44 6.71 4.53 4.05 * Threshold value= light extinction (B ext ) for OC + EC > 50% of total daily B ext AND total B ext > 50 Mm -1 ** For this date, total B ext was < 50 Mm -1 , but the day was investigated due to high OC + EC impact.

MRPO examined five of the days shown above to a ssess whether OC from fire may cause or contribute to these elevated values. 89 Using back trajectories and satellite maps of fires, it appears that monitoring data for four of the five days was highly influenced by wildfires in Manitoba and Saskatchewan.

The MPCA analyzed those days not analyzed by MRPO . Overall, most of the nine days shown above with the highest light extinction due to OC and EC app ear to be influenced by fires in Canada. There are only two days, June 5, 2003 and July 26, 2004, wher e it is reasonable to conclude that fires within Minnesota contributed to the elevated concentrations of OC and EC. On these days, a small prescribed burn and a wildfire upwind of the monitor, respec tively, appear to affect the IMPROVE data.

In Minnesota, federal and state land managers ge nerally conduct prescribed burning during a spring season (March 15 - May 31) and a fall season (Sept 15 - Oct 31). None of the 20% worst days shown in Table 10.5 occur in these intervals. Elevated concentrations of OC in the summer can be due in part to wildfires, but can also be due to high biogenic emissi ons. Because of the extensive forests to the north of Minnesota, it is likely that some of the high OC measured in summer at the IMPROVE monitors is biogenic secondary organic aerosol that originates in Canada. Further details on the visibility impact of fires can be found in Appendix 10.7.

MRPO determined that subtracting the five days of high OC concentration from the 20% worst days, in general, had a relatively small effect on visibility impa irment for the baseline aver age – a range 0.3 dv at Minnesota’s Class I areas to less than 0.2 dv at Michigan’s Class I areas. 90

Although the data show that fires do have some impact on visibility in Minnesota’s Class I areas, the impacts on the 20% worst days tend to be only a few poor visibility days in the summer caused by wildfires. Often these wildfires occur in Canada. For this reason, Minnesota determined that OC particles are not good candidates for a dditional controls as part of the long-term strategy. Emissions from wildfires should be included in natural condition estimates, and any tran sboundary fire impacts must be addressed by EPA. Emissions from prescribed a nd managed fires within Minnesota are managed in conformance with Minnesota’s Smoke Management Plan, described below.

Agricultural Smoke Management Agricultural burning requires an open burning perm it from the Minnesota Department of Natural Resources. In general, agricultural burning in Minnesota is limited to grass and stubble burning, particularly of bluegrass and timothy grass. This light fuel type produces short-term smoke events

89 MRPO, 2007b; LADCO, 2008.

90 MRPO, 2007b; LADCO, 2008, pg 45.103 without a lot of combustion of biomass and smoldering. In addition, most agricultural burning occurs in the northwest area of the state, away from the Class I areas.

Agricultural burning is not covered by Mi nnesota’s Smoke Management Plan, and EPA’s Interim Air Quality Policy on Wildland and Prescribed Fires specifies that it does not apply to agricultural burning. 91 Minnesota is not addressing agricultural burning in this SIP, as an analysis of the days during the baseline visibility period with the highest concentrations of organic and elemental carbon shows that none of these days were attributed to agricu ltural burning within Minnesota.

EPA is due to issue new final guidance for wildland and prescribed fire, and separate guidance is likely to be issued to address agricultural burning. Should ag ricultural fires become an important contributor to poor visibility, Minnesota will address agricu ltural fires in future SIP revisions.

Forestry Smoke Management Minnesota’s various ecosystems are dependent on and ad apted to fire disturbance, and prescribed burning has become a common management tool for these ecosys tems. Prescribed burning is also used to reduce the frequency, size, and intensity of wildfires and consequently reduce total emissions from vegetative burning. This benefit to air quality is promoted by the application of the Smoke Management Plan (SMP), whereby practices to reduce the impact of burning on air quality are added to the “prescription” that determines the conditions for igniting and managing the fire.

Most open burning in Minnesota is required to ha ve a burn permit, and a process is in place for authorizing those permits and granting approval to ma nage fires. The Commissioner of the Minnesota Department of Natural Resources (DNR) is granted au thority in Minnesota Statutes 88.01 to 88.22 to control open burning; the DNR reviews burn applicati ons and issues burn permits for all open burning in Minnesota, except on federal and tribal lands. 92

More importantly for management of fire emissions , Minnesota has a Smoke Management Plan that has been in effect since 2002; although briefly described here the MPCA is not proposing that it be formally incorporated into Minnesota’s SIP. The SMP is subject to occasional updating and revision, and was updated in December 2007.

The MPCA works with state and federal land manage rs as part of the Minnesota Incident Command System (MNICS) Prescribed Fire Working Team 93 to develop the SMP. The SMP is implemented through a Memorandum of Agreement between the U.S. Department of Agriculture, Forest Service; U.S. Department of the Interior, National Park Service; U.S. Department of the Interior, Fish and Wildlife Service; The Nature Conservancy; Minnesota Depart ment of Natural Resources; and the MPCA. The signatory agencies agree to apply the provisions of the SMP to all prescribed fires that they ignite and all naturally occurring fires that they manage.

Minnesota believes this program addresses visibility im pairment due to fires. Minnesota certified in a letter to the EPA on September 2, 2004 that a basic program has been adopted and implemented. EPA’s reply is included in Appendix 10.8. The key prov isions of the 2002 SMP are described below, and a complete copy of the SMP can be found on the web.

According to EPA’s guidance, “The purposes of SM Ps are to mitigate the nuisance and public safety hazards...posed by smoke intrusions into populated areas, to prevent deterioration of air quality and

91 U.S. EPA, 1998.
92 For more information, see Minnesota DNR, Burning Questions (webpage).

93 Now Prescribed Fire/Fuels Working Team104 NAAQS violations, and to address visibility im pacts in mandatory Class I Federal areas.” 94 Similarly, Minnesota’s SMP sets out “regional haze rules to impr ove visibility in the mandatory Class I areas” as a primary reason for implementing a smoke management plan in the state. Minnesota considers the SMP to be an important tool to achieve the purposes of the Regional Haze Rule. In addition to addressing NAAQS and regional haze issues, Minnesota’s SMP was developed due to predicted significant increases in the use of prescribed burning.

Minnesota’s SMP is based on EPA’s Interim Air Quality Policy. 95 It includes the following requirements as laid out in that guidance:

• Authorization to burn

• Minimizing air pollutant emissions

• Smoke management components of burn plans

• Actions to minimize emissions

• Evaluation of smoke dispersion

• Air quality monitoring

• Public education and awareness

• Surveillance and enforcement

• Program evaluation

Under the SMP, all prescribed fires must have burn plans that include the following elements:

• Location and description of the area to be burned

• Personnel responsible for managing the fire

• Type of vegetation to be burned

• Area (acres) to be burned

• Amount of fuel to be consumed (tons/acre)

• Fire prescription including smoke manage ment components and dispersion index

• Criteria the fire manager will use for making burn/no burn decisions

• Safety and contingency plans

The SMP requires calculation of a dispersion (or ventil ation) index based on mixing height and transport winds to mitigate smoke impacts. Dispersion index categor y is used with fuel type and daily size of fire to determine minimum proximity to nearest downwind receptors. Prescribed burns cannot be ignited outside these conditions.

Minnesota’s SMP gives the MPCA responsibility for an annual assessment of the effect of prescribed burning on air quality within Minnesota. This a nnual review includes an examination of both PM 2.5 and ozone (O 3 ) monitoring data in Minnesota, including data from the IMPROVE monitors, for correlations between air quality and wildland and prescribed fires. This report is provided to the Prescribed Fire/Fuels Working Team of MNICS as part of the annual evaluation of the SMP.

The four step process generally used is as follows: 1) Examine the air sample data from monitors at geographically appropriate sites for high values of PM 2.5 and ozone during the prescribed fire season;

94 U.S. EPA, 1998.
95 U.S. EPA, 1998.105 2) Determine the wind speed and direction during the day and the hours of elevated PM 2.5 and ozone concentrations; 3) Determine the time, location, and size of pr escribed burns conducted by SMP-participating agencies with respect to the time and location of the recorded air concentrations (includes evaluation of wildfires); and 4) Use back-trajectory mapping to determine the movement of higher-elevation air parcels with respect to the location of potential fire sources.

The Working Team also looks at the acres of prescribed burns planned for the next five years, the need to expand the scope of the program to include authoriza tion of other open burning, and the need for changes in the SMP.

Future of SMP and Fires The Prescribed Fire/Fuels Working Team of MNIC S completed a review and revision of Minnesota’s SMP in December 2007.

Following is a summary of the major changes made to the SMP:

• Additional participating agencies (Minnesota Department of Military Affairs and Minnesota Department of Transportation)

• Update of acres burned by prescribed fire

• Update of PM 10 , PM 2.5 , and O 3 NAAQS description

• Revision of “climate of smoke dispersion in Minnesota” section

• Addition of references to EPA’s Exceptional Even ts Rule (March 2007) and effects on prescribed burning (including record keeping in burn plans to demonstrate exceptional events)

• Revision of table in 4.2.3 “Smoke Management & Dispersion” and combination of dispersion index categories, fuel type/burn acres, and distance to receptors charts

• Addition of the EPA’s Air Quality Index (AQI) information to Appendix

• Update of PM 10 , PM 2.5 , and O 3 monitors and locations ta ble and maps in Appendix

As necessary, the SMP will continue to be update d periodically by the participating agencies.

Enforceability of emission limitations and control measures 40 CFR 51.308(d)(3)(v)(F) requires Minne sota to ensure that emission limitations and control measures used to meet RPG are enforceable.

Appendix 9.7 contains the state rulemaking that made both BART and CAIR applicable requirements for stationary sources. The Administrative Orders requiring CEMs or a comparable method of emissions measurement from the taconite facilities are included in Appendix 9.7. Minnesota requests EPA approval of these measures.

Minnesota will submit additional enforceable documen ts in the Five Year SIP Assessment. Once established, BART emission limits will be include d in each taconite facility’s Title V permit and submitted to EPA. In addition, the MPCA will develop enforceable documents such as permits, Administrative Orders, or a state rule that will require the taconite facilities to conduct the research into additional emission reduction measures (if such is not already being undertaken voluntarily and reported to the MPCA) and implement control strategies found to be reasonable.106 Anticipated net effect on visibility resulting from projected changes to emissions 40 CFR 51.308(d)(3)(v)(G) requires Minnesota to ad dress the net effect on visibility resulting from changes projected in point, area and mobile source emissions by 2018.

The emission inventory for Minnesota projects changes to point, area and mobile source inventories by the end of the first implementation period resulting from population growth; industrial, energy and natural resources development; land management; and air polluti on control. These changes, and their net effect on visibility, are described in Chapter 8.

Potential Future Projects and Impacts Other actions are likely to take place over the next 10 years that will impact visibility in the Class I areas in 2018, but which are not included in the RPG.

For example, Minnesota expects several surrounding states to submit additional control measures in order to meet their responsibilities under the Regiona l Haze Rule and for attainment of the PM 2.5 and ozone NAAQS. As these control measures are not yet propose d or implemented, they were not included in the RPG. The MPCA also intends to further investigat e control measures that were shown by the EC/R report to be potentially reasonable under the four factors. This is discussed further below.

In addition, there are the potential impacts of both climate change and regulations to reduce greenhouse gases. Climate change may well impact the meteorolog y of the area, affecting the transport of precursor pollutants. However, these impacts are extremely diffi cult to predict and are more likely to be seen over the long-term of the Regional Haze program (to 2064) ra ther than over the next ten years. In addition, research suggests that the “sensitivities of ozone and PM 2.5 formation to precursor emissions are found to change only slightly in response to climate change.” 96 This indicates that control strategies put in place to reduce precursor emissions (NO X and SO 2 ), such as those in this SIP, will continue to be effective in reducing PM 2.5 , and haze, even if the climate has changed.

Minnesota has implemented some rules and laws in order to reduce greenhouse gas emissions, and more such policies are likely to be forthcoming. For exam ple, there is now a new Renewable Energy Standard, Minnesota Statute 216B.1691, requiring 25% of the st ate’s energy to come from renewable sources by 2025. This is likely to lead to more non-fossil fuel based energy generation, perhaps leading to lower future emissions from electricity generation than currently predicted. (See Appendix 10.2).

In addition, Minnesota has been engaged in a statew ide process of determining what actions the state should take in response to global c limate change. Although any measures undertaken as a result of this process will be intended to reduce emissions of carbon dioxide and other greenhouse gases, it is likely that some of them may have the added benefit of re ducing emissions of fine particulate matter and its precursors, thereby helping to reduce regional haze.

96 Liao, et al., 2007. p 8355.107 Reasonable Progress Goals At this time, based on the aforementioned informatio n, Minnesota is setting the reasonable progress goals at the deciview levels shown in the following table.
Table 10.7: Reasonable Progress Goals for Class I areas

Class I area 2018 Visibility 20% Worst Days (dv) 2018 Visibility 20% Best Days (dv) Projected Annual Improvement

2004-2018 (W20%, dv) Projected Improvement by 2064 (W20%, dv) Year Reaching Natural Conditions

(W20%) BWCAW 18.6 6.4 0.09 5.6 2093 VNP 18.9 7.1 0.04 2.6 2177

The RPG provides for less annual progress towards th e ultimate visibility goals than the URP.

The RPG set in this SIP is the minimum visibility improvement Minnesota considers to be reasonable, and contains emission reductions re sulting from all controls currently known to be reasonable – namely BART, CAIR, other on the books and national strategi es, and emission reductions due to the Northeast Minnesota Plan, all of which are described above in the long-term strategy. The MPCA anticipates that the levels indicated in this table represent an in terim decision on the reasonable level of visibility improvement.

Factors Impacting RPG

International Emissions There is some indication, particularly from the modeling performed by CENRAP, that Minnesota’s two Class I areas may have significant visibilit y impacts resulting from Canadian emissions. 97 However, estimates of this international impact vary due to difficulties quantifying Canadian emissions and discrepancies between models. (For more information, see Chapter 8 and the TSD.) The MPCA requests that EPA work with Canada in order that future SI P revisions for regional haze will be able to include more accurate emission estimates and modeling in or der to better quantify any international impact on visibility. Where necessary, EPA should then work with Canada and support re ductions in haze-causing emissions.

Emissions from Contributing States At this time, Minnesota believes that the RPG in Tabl e 10.6 is an appropriate goal because of uncertainty surrounding future levels of emission reductions. Some impacting states are working on a multi-SIP approach and have yet to determine what reductions are reasonable in their states for both haze and NAAQS attainment purposes. Although we cannot compel other states to undertake reductions, Minnesota believes that some additional emission reduc tions from other states have been shown to likely be reasonable, and that further emissions reductions w ill occur due to attainment SIPs, resulting in larger visibility improvement.

Minnesota has used the EC/R five factor analysis report (see Appendix 10.5) the control cost analysis carried out by Alpine Geophysics for CENRAP and the CENRAP Control Sensitivity Model run (Appendix 10.6) to identify potentially reasonable region- wide emission reduction strategies that could be adopted in future years to strengthen Regional Haze SI Ps. Minnesota has therefore asked the contributing states to evaluate whether these control strategies ar e reasonable, under the four factors, and to report the results of this analysis in their SIPs or Five-Year Assessments. (See Appendix 3.2)

97 ENVIRON/UCR, 2007. pp 1-23 to 1-24 and p 5-2.108 Preliminary indications from the contributing states are that those states are, at this time, unlikely to undertake additional emission reductions for regional h aze purposes. Of the contributing states, Missouri has indicated in its SIP that it does not believe that it is a significant contributor to visibility in either of Minnesota’s Class I areas. Iowa has indicated that it does not feel that additional controls are costeffective due to their cost in $/deciview, and that fu rther review of some contro ls is unwarranted due to the uncertain status of federal regulation. (See Appendix 3.2.) Although Minnesota has continued to consult with these states, we have been unable to reso lve these disagreements. Therefore, Minnesota asks EPA to make a determination as to whether controls fr om these states to address visibility impairment in Minnesota’s Class I areas are appropriate.

It should be noted that although m odeling was done to evaluate the visi bility conditions if the contributing states commit to certain control strategies that Mi nnesota has deemed to be potentially reasonable, Minnesota is not yet asking the contributing states to make such commitments. Instead, Minnesota has simply asked the contributing states to look at the r easonableness of those control strategies that could improve visibility in Minnesota’s Class I areas.

In addition, the MPCA intends to c ontinue to research control strategi es and other means to strengthen the Regional Haze SIP. Should such strengthening meas ures be found, or should other states commit to control measures, Minnesota intends to revise the RPG for 2018 in the Five Year SIP Assessment, in order to reflect the additional contro l strategies found to be reasonable.

Specific Control Strategies to Be Reviewed The specific strategies that at this time appear potentia lly reasonable, despite a lack of information to fully evaluate them at this time, and Minnesota’s expect ation for each of these strategies for both Minnesota and the contributing states, are outlined below.

EGU SO 2 Reductions Minnesota has asked the contributing states to continue to look at their EGU emissions of SO 2 , with a particular focus on possible reductions in states with em ission rates that appear to be higher than average among the Midwestern states. Although the MPCA rec ognizes that contributing states face a variety of regulatory demands and fuel types, making it perhaps difficult to attain uniform emission performance, it appears that an emission rate of about 0.25 lb/MMBtu should be achievable in a cost-effective manner. This is the level being achieved in Minnesota and Illinois, and the EC/R report shows that the “EGU1” scenario, a 0.15 lb/MMBtu emission rate, is generally achievable in the Midwest at a reasonable $/ton figure, estimated to range from $560 - $2,900/ton. 98

Minnesota would expect the identified states to demonstrate that reductions are occurring or being undertaken that will allow the state to reach the above-m entioned emission rates, or to evaluate strategies for reaching the emission rates and state in their SIPs or Five-Year SIP Assessments why further reductions of SO 2 from EGUs are not reasonable. Further re ductions may not be reasonable due to the cost of implementation or lack of impact on visibilit y impairment, but they should be evaluated for each state’s specific circumstances.

At present, it appears as though Illinois has planned or proposed reductions that appear reasonable. It appears that more cost effective reductions are possi ble in Iowa, Missouri, North Dakota, and Wisconsin. Since Wisconsin is the largest non-Minnesota contributor to visibility impairment in Minnesota’s Class I areas, their efforts to reduce EGU SO 2 emissions are particularly important.

98 Battye, et al, 2007, pp 27 – 28.109 EGU NO X Reductions In general, dispersion models have been less reliabl e in predicting the nitrate component of particulate matter (as compared to the sulfate component). Wisconsin, Missouri, and Illinois have already reduced NO X emissions to alleviate ozone standard violations , and Iowa appears to already have relatively low EGU NO X emissions. Minnesota has asked these states to share information on any NO X controls being undertaken as part of their ozone SIPs, in order fo r Minnesota to fully include any information on the resulting emission reductions.

Minnesota has asked North Dakota to evaluate their EGU emissions of NO X and to describe in their SIP or Five-Year SIP Assessment why further reductions of NO X from EGUs are not reasonable. Again, an emission rate of approximately 0.25 lb/MMBtu appear s to be a reasonable benchmark. Further reductions may not be reasonable due to the cost of implementa tion in $/ton or $/deciview or lack of impact on visibility impairment, but they should be evaluated fo r North Dakota’s specific circumstances. The EC/R report indicates that control strategies to reach a NO X level of 0.10 lb/MMBtu may be available in North Dakota in a range of $760 – $3,300/ton. 99

Again, Minnesota acknowledges that each state is in a unique situation in terms of regulatory background and a general EGU fuel mix. The use of emissi on rates to identify areas where additional emission control strategies should be investigated does not mean that Minnesota expects all contributing states to achieve the same emission rates.

However, Minnesota believes contribut ing states with higher emission rates need to evaluate potential control measures, and should, in their initial SIPs or Five Year SIP Assessments, show either enforceable plans to reduce emissions or a rationale for why such emission reductions are not reasonable.

Should the five contributing states reach the 0.25 lbs/MMBtu EGU emission levels, and if:

• States in the MRPO commit to the reductions asked of them by MANE-VU; and

• Controls are installed at Xcel Energy, Sherburne plant; 100

then modeling shows the future visibility conditions ar e likely to be better than described in the RPG. These conditions are shown below, in Table 10.7.

Table 10.8: Alternate Goals for Class I areas

Class I area 2018 Visibility 20% Worst Days (dv) 2018 Visibility 20% Best Days (dv) Projected Annual Improvement 2004- 2018 (W20%, dv) Projected Improvement by 2064 (W20%, dv) Year Reaching Natural Conditions

(W20%) BWCAW 18.3 6.4 0.11 6.9 2079 VNP 18.7 7.1 0.06 3.4 2127

Several other control strategies were shown to be potentially reasonable, though no modeling was performed on the resulting visibility improvement.

ICI Boiler Emission Reductions
Minnesota will commit to a more detailed review of potential NO X and SO 2 reductions from large ICI boilers in order to determine if reasonable measures exist that could further strengthen this Regional Haze SIP. For ICI Boilers, the EC/R report indicated th at cost-effectiveness ranges from $1,149 to $3,021/ton

99 Battye, et al, 2007, pp 27 – 28.

100 If emissions are controlled to the levels used in the modeling. See the TSD for more details.110 of SO2 and $699 - $5,478/ton of NO X reductions in the Midwest. 101 If significant cost effective reductions prove feasible from this sector, regula tions or permit limits w ill be developed by 2013. Minnesota expects the five contributing states to also commit to this future evaluation.

Other Point Source Emission Reductions Reciprocating engines and turbines appears to be a sector with potential cost effective NO X controls; the EC/R report estimates the cost of NO X controls to be between $240 - $8,200/ton. 102 Minnesota commits to reviewing this sector in more detail and if, after c onsideration of planned fede ral control programs, cost effective reductions appear feasible, Minnesota commit s to develop regulations or permit limits for major sources by 2012 in order to strengthen the SIP. Minnesota will expect the five other contributing states to make a similar commitment.

Mobile Source Emission Reductions There appear to be relatively few additional cost effective NO X controls on mobile sources available to states, partially due to the large reductions resulti ng from federal requirements. Minnesota commits to work with MRPO states to implem ent appropriate cost effective NO X controls to improve visibility and lower ozone levels in non-attainment areas.

NOx Modeling, Ammonia, Agricultural Sources It is not appropriate to commit to control of ammonia sources at this time. However, there is a clear need to improve 1) our understanding of the role of ammonia in haze formation, 2) ou r understanding of potential ammonia controls, and 3) the accuracy of particulate nitrate predictions. Minnesota does not believe that conducting such research solely on a state- based level would be appropriate at this time, as information on ammonia’s role particulate formation a nd potential controls is needed throughout the U.S., and regional similarities are likely. Minnesota th erefore strongly encourages EPA and the regional planning organizations to continue work in these ar eas and commits to work with EPA and the RPOs to these ends. The MPCA hopes also to re-evaluate th e growth factors used in predicting agricultural ammonia emissions and include that inform ation in the Five Year SIP Assessment.

To summarize, Table 10.8, below, contains all the rele vant visibility conditions given throughout this SIP.
Table 10.9: Visibility Conditions, URP and RPG for Minnesota’s Class I areas (dv)

Baseline W20% Baseline B20% 2018 URP W20% 2018 RPG W20% 2018 A lt Goal W20% Natural W20% Natural B20% BWCAW 19.9 6.4 18.0 18. 7 18.3 11.6 3.4 V NP 19.5 7.1 17.8 19. 0 18.7 12.1 4.3

Steps in Reviewing Control Strategies and Revising RPG In reviewing additional control strategies to dete rmine additional strengthening measures that are reasonable under the Regional Haze rule, the MPCA comm its to further evaluation of reasonable control strategies that are possible within Minnesota. In addition, Minnesota will focus on strategies that will result in emission reductions in those other states that contribute more than 5% to visibility impairment in BWCAW and VNP: Wisconsin, Iowa, N. Dakota, Missouri and Illinois. The MPCA will work with these contributing states through their submittals of the fi rst haze SIP and through 2013 to develop additional reasonable control strategies.

101 Battye, et al, 2007, pp 45.

102 Battye, et al, 2007, pp 57.111 In the Five Year SIP Assessment, the MPCA woul d submit enforceable documents for any additional control measures found to be reasonable within Minne sota. In addition, that report would contain a listing of the additional control measures to be impl emented by the other contributing states. Minnesota would then submit modeling that includes all these enforceable measures and would revise the 2018 RPG if the modeling shows, as expected, a larger degr ee of visibility improvement resulting from the chosen control strategies.

Timeline for Reviewing Control Strategies Minnesota commits to reviewing these control strate gies on such a timeline that the Five Year SIP Assessment will include the four factor analysis for th ese additional control strate gies and that any control strategies deemed to be reasonable by Minnesota or any contributing st ates will be in place to strengthen the SIP with an enforceable document (state rule, Or der, or permit conditions ). Although any control measures ultimately deemed to be r easonable may not be fully implemented by 2013, they will clearly be “on the way” and the SIP Report will include esti mates of emission reductions and projected 2018 visibility conditions.

Acknowledging the different timelines among states, especi ally the fact that some states are far along in the process of writing their Regional Haze SIPs, Minn esota expects that all other contributing states would commit to a similar timeline of reviewing pot ential emission reductions for the Five Year SIP report, allowing for predictions of the emission re ductions and visibility improvement resulting from the implementation of reasonable control measures by 2018 to be contained in that report.

Minnesota has determined, based on th e reasons delineated above, that the rate of visibility improvement by 2018 shown in Table 10.6 is reasonable and here by adopts it as the reasonable progress goal (RPG) for the listed Class I areas. The RPG provides for an im provement in visibility for the most impaired days and ensures no degradation in visibility for the least impaired days.112 

### Chapter 11. Periodic Plan Revisi ons and Determination of Adequacy

2018 SIP Revision Each state is required by 40 CFR 51.308(f) to revi se its regional haze implementation plan and submit a plan revision to EPA by July 31, 2018, and ever y 10 years thereafter. In accordance with the requirements listed in 40 CFR 51.308(f) of the federa l rule for regional haze, Minnesota commits to revising and submitting this regional haze implementa tion plan by July 31, 2018, and every 10 years thereafter.

Five Year Report In addition, 40 CFR 51.308(g) requires periodic reports evaluating progress towards the RPG established for each mandatory Class I area. In accordance with these requirements, Minnesota commits to submitting a report to EPA every five years following th e initial submittal of the SIP, with the first report due December 15, 2014; th is report will evaluate the progress made towards the RPG for each mandatory Class I area located within Minnesota and in each mandatory Class I area located outside Minnesota which may be affected by emissions from within Minn esota. The report will be in the form of a SIP revision, with the first report to be submitted within five years after submittal of this SIP revision. All requirements listed in 40 CFR 51.308(g) shall be addr essed in the SIP revision for reasonable progress, including consultation with Federa l Land Managers during the preparation of that SIP revision.

Actions to be Taken Prior to Five Year Report In order to meet our commitments laid out in Chapter 10 of this SIP and to ensure the most accurate estimation of 2018 visibility is made in the Five Y ear Assessment, the actions laid out in the following table need to occur. The table begins with those activities where MPCA is the responsible party (and to which MPCA is committing in this SIP), and moves on to recommended actions for other parties, such as EPA and the RPOs. These actions are described in detail elsewhere in the SIP.
Table 11.1: Activities to be Completed Prior to Five Year SIP Assessment
Description Responsible Party Ongoing tracking of emissions for Northeast Minnesota Plan MPCA Analysis of NO X and SO 2 emissions from taconite facilities obtained through Administrative Orders MPCA

Remaining BART emission limit determinations for taconite facilities MPCA Estimation of NO X and SO 2 emission limits to be obtained from implementation of BART for taconite facilities (compared to 2002 baseline) MPCA

Incorporation of BART emission limits into facility permits MPCA Development of enforceable mechanism to require pilot testing of emission reductions/control strategies at taconite facilities MPCA

Research and pilot testing into cont rol strategies and methods to reduce taconite emissions Taconite facilities

Reporting on outcomes of pilot testing into emission reduction methods for the taconite facilities Taconite facilities

Evaluation of pilot test reports and determination of a dditional reasonable controls or emission reducti ons from taconite facilities. MPCA

Determination if 2012 Northeast Minneso ta Plan target is being met and projection if 2018 target will be met; evaluation of minor source emissions MPCA

If necessary, evaluation of control stra tegies for sources in the Northeast Minnesota plan that have not otherw ise investigated control strategies. MPCA and facilities

Evaluation of control strategies for ICI Bo ilers, other point sources (such as MPCA113 reciprocating engines) and mobile sour ces to determine if reasonable control strategies are available Contributing states RPOs Research to improve understanding of overall ammonia emissions, growth and control, and role of ammonia in haze formation EPA RPOs Evaluation of reasonable control strategies to reach an emission rate of 0.25 lbs/MMBtu for NO X and SO 2 from EGUs Contributing states

Better quantification of international emissions EPA RPOs

Contents of Five Year Report In the five year report, Minnesota will undertake an em ission review in order to determine if the emission reductions projected to occur through the application of BART, CAIR (or a revised CAIR rule), voluntary control measures, and the other components of Minne sota’s long-term strategy have occurred. The review will also look at what new em ission sources have begun operation.

The MPCA, perhaps in conjunction with the RPOs, al so hopes to assess the accuracy of the emission growth factors for certain SCCs, such as agricultural operations.

Minnesota’s five year SIP report will contain the following items:

BART Limits As discussed in the section on the application of BA RT in Minnesota, although Minnesota has determined that BART for the taconite facilities is good com bustion practices, along with some facility-specific measures as described, at this time the necessary information is not available to set emission limits associated with existing controls. Because facilitie s will be required to operate CEMs or undertake a testing method of comparable accuracy in the next few years, MPCA commits to establishing BART emission limits by September 2011, prior to the five year SIP report.

More accurate emission measurements will help provide knowledge of emission formation to understand how modifications to operation and fu rnace design could result in lower NO X and SO 2 emissions. The BART limits in conjunction with more accurate measurement of emissions will allow the MPCA to estimate the emission reductions that will result fro m BART implementation. This information will be provided in the five year report.

Northeast Minnesota Plan Evaluation and Taconite Retrofit Requirements A major portion of the five-year SIP adequacy and de termination report will be an evaluation of progress towards meeting the Northeast Minnesota emission reduc tion target, described previously. The Northeast plan contains a target of 20% emission reductions by 2012; Minnesota will include emission inventory numbers to determine if this target is being met, along with future emission projections for the area to determine if the 30% reduction go al for 2018 will be met.

In addition to the emission reducti on target, Minnesota commits in its current long-term strategy to potentially require controls on taconite facilities re gardless of whether the emission reduction goal is being met. As described previously in Chapter 10, the taconite facil ities will be required to investigate control technologies and pollution prevention practices through pilot tests and other mechanisms, and to report to MPCA on feasible emission reduction stra tegies. MPCA will then undertake a BART-like review of these reports and contro l strategies and evaluate them based on the statutory factors and the status of progress towards the emission target. The fi ve year SIP report will likely include the results of the analysis, a determination of any control strategi es or pollution prevention projects that are reasonable at each of the taconite facilities, and enforceable me chanisms for requiring application of these measures.114 In addition to the emission reduction measures that wi ll be required from the taconite facilities, Minnesota will review emission projections for the area. If the 2012 emission target is not met, the MPCA will consult with FLMs, tribes, and stakeholders to consider the following information:

• The degree to which emissions are over the 2012 target.

• Plans for emissions reductions from control upgrades or emission increases from newly permitted sources (in 2013-2018) that will dete rmine if the 2018 target will be met

• The trend in ammonium nitrate and sulfate concentrations measured by monitors for BWCAW, VNP, and Isle Royale.

• Predicted visibility improvement in 2018 at Cl ass I receptors as determined by modeling performed for the 2012 SIP Report.

• The availability of cost-effective control measures.

Based on this information and consultation, the MP CA would determine what actions need to be undertaken and described by the five-year SIP report. There could be many possible actions, including:

• Assessing availability of additional cost-effective emission reductions

• Requiring individual facilities to propose and im plement some kind of available retrofit technology

• Encouraging voluntary implementation of control measures

• Continued tracking of emissions and emission re duction projects and establish a year for next check-in, e.g. 2015 or 2018.
If the review of emissions shows that the 2012 target is met, the SIP report will assess permit applications approved and under review and project whether 2018 targets will be met. If it appears that the 2018 emission target will not be met, the state will follow the same procedures as de scribed above. If the 2012 target is met in 2012 the 2018 is projected to be me t, the state will continue to track emissions through 2018.

Reasonable Progress Update It is likely that Minnesota’s Class I areas will show visibility improvement beyond the RPG set in Chapter 10 of this SIP revision. As stated in Chapter 10, is it not clear at this time which control measures those states that impact Minnesota’s Class I areas are likel y to find to be reasonable. The MPCA has worked with those states to express our opinion as to what is reasonable.

However, the 2018 RPG set in Chapter 10 is th e minimum visibility improvement that Minnesota considers to be reasonable. If additional control stra tegies are undertaken in Minnesota, the Five Year SIP Assessment will include enforceable measures for these strategies. In addition, between the submission of this SIP and the Five Year SIP a ssessment, Minnesota will have implemented BART emission limits for the taconite facilities, and will have a better sense of additional controls that will be taken at the taconite facilities, under the Northeas t Minnesota plan, or to meet other regulatory requirements, such as a repromulgated CAIR rule.

Therefore, in the Five Year SIP assessment, the MPCA will revise the RPG to reflect the further visibility improvement expected by 2018. This will include an y additional controls stra tegies being implemented in Minnesota or surrounding states.

Adequacy Determination Depending on the findings of the five-year report on pr ogress towards the goals established for each Class I area, Minnesota commits to determining the adequacy of this existing SIP and undertaking one of the actions listed in 40 CFR 51.308(h). The findings of the five-year progress report will determine which115 action is appropriate and necessary , and could result in several different actions, depending on the progress towards the visibility goals and the location of the emissions impacting that progress.

Should it be determined that the controls and strategi es within the existing SIP are improving visibility in BWCAW, VNP and Isle Royale so that they are on track to meet the reasonable progress goal set in this SIP for 2018, Minnesota will determine that the exis ting SIP requires no further substantive revision in order to achieve established goals. Should it be determined that the c ontrols and strategies within the existing SIP are improving visibility in the Class I areas so that they will exceed the RPG for 2018 set in this SIP, Minnesota will likely revise the RPG to s how more visibility improvement expected by 2018, and determine that the existing SIP requires no furthe r substantive revision. Minnesota will then provide to the Administrator a negative declaration, stating th at further revision of the SIP (beyond the Five Year SIP Assessment) is not needed at this time.

Should the MPCA determine that the strategies implem ented in the existing SIP appear to be inadequate to ensure reasonable progress due to emissions from other states which participated in the regional planning process or the Northern Class I consultation process, Minnesota will provide notification of that fact to the Administrator and the relevant states. Minnesota will then collaborate with those states through the regional planning process to address the deficiencies in the SIP.

Similarly, should Minnesota determine that the curre nt SIP may be inadequate to ensure reasonable progress due to emissions from another country, the MPCA will provide such notification, along with available information, to the Administrator.

If Minnesota determines that the existing SIP is inadequate to ensure reasonable progress due to emissions within Minnesota, the MPCA will revise its SIP within one year in order to address the plan’s deficiencies.