Sevier Playa Potash Project

Resource Report

Air Quality and Climate

Prepared For:

Bureau of Land Management Fillmore Field Office

Prepared By:

McVehil-Monnett Associates Greenwood Village, Colorado

and

ENValue Castle Rock, Colorado

June 2019

THIS PAGE INTENTIONALLY LEFT BLANK

Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table of Contents

1.0 Introduction ...... 1 2.0 Proposed Action and Alternatives ...... 1 2.1 Applicant Committed Design Features ...... 1 2.2 Supplemental Plans ...... 1 2.3 Proposed Action ...... 2 2.3.1 Mining Project ...... 3 2.3.2 Rights-of-Way ...... 5 2.3.3 Mineral Materials ...... 7 2.3.4 Construction ...... 7 2.3.5 Operation and Maintenance ...... 8 2.3.6 Decommissioning and Reclamation ...... 8 2.4 Alternatives ...... 8 3.0 Analysis Area ...... 10 4.0 Regulatory Framework ...... 13 4.1 Ambient Air Quality Standards ...... 13 4.2 New Source Review / Prevention of Significant Deterioration ...... 14 4.3 New Source Performance Standards / National Emission Standards for Hazardous Air Pollutants ...... 16 4.4 Federal Operating Permit (Title V) ...... 16 4.5 Air Quality Related Values ...... 16 5.0 Methods ...... 17 5.1 Differences between Draft Analysis and Final Analysis ...... 18 5.2 Emissions Inventory ...... 19 5.2.1 Emissions from Stationary Sources ...... 21 5.2.2 Emissions from Fugitive Sources ...... 22 5.2.3 Emissions from Tailpipe Exhaust ...... 24 5.2.4 Project Emissions Summary ...... 25 5.2.5 Emission Inventory Limitations ...... 29 5.3 Dispersion Modeling Methods and Setup ...... 29 5.3.1 Project Years to Model ...... 29 5.3.2 Model Input: Project Sources and Emissions ...... 30 5.3.3 Model Input: Building Downwash Parameters for Point Sources ...... 33 5.3.4 Model Input: Meteorology ...... 34 5.3.5 Model Input: Receptors ...... 34 5.3.6 Model Input: Specialty Parameters for NO2 ...... 35 5.3.7 Model Input: Specialty Parameters for PM10 ...... 36 5.3.8 Air Dispersion Model Limitations ...... 39 5.4 Nearby Background Sources ...... 40 5.5 Background Air Concentrations ...... 41 5.5.1 Air Pollutants: PM10 and PM2.5 ...... 41 5.5.2 Air Pollutant: CO ...... 45 5.5.3 Air Pollutant: SO2 ...... 45 5.5.4 Air Pollutant: NO2...... 45 5.5.5 Background Concentration Limitations ...... 46 6.0 Affected Environment ...... 47 6.1 Regional Climate ...... 47 6.2 Regional Air Quality ...... 49 6.2.1 Carbon Monoxide ...... 51

i Sevier Playa Potash Project Resource Report: Air Quality and Climate

6.2.2 Sulfur Dioxide ...... 51 6.2.3 Nitrogen Dioxide ...... 51 6.2.4 Particulate Matter ...... 52 6.2.5 Ozone ...... 52 6.3 Local Topography of the Analysis Area ...... 52 6.4 Local Air Quality and Meteorology ...... 52 6.5 Climate Change ...... 54 7.0 Analysis of Effects ...... 61 7.1 Applicant Committed Design Features ...... 61 7.2 Direct and Indirect Effects ...... 62 7.2.1 Proposed Action ...... 62 7.2.2 Action Alternatives ...... 93 7.2.3 No Action Alternative ...... 93 7.3 Cumulative Effects ...... 94 7.3.1 Proposed Action ...... 95 7.3.2 Action Alternatives ...... 100 7.3.3 No Action Alternative ...... 101 7.4 Additional Recommended Mitigation ...... 101 8.0 Conformance with Applicable Land Use Plans, Policies, and Controls ...... 101 8.1 NAAQS ...... 101 8.2 New Source Review / Prevention of Significant Deterioration ...... 102 8.3 New Source Performance Standards / National Emission Standards for Hazardous Air Pollutants ...... 102 8.4 Federal Operating Permit ...... 102 8.5 Air Quality Related Values ...... 102 9.0 References ...... 103

Tables Table 1 Mining Project Summary ...... 4 Table 2 Right-of-Way Summary...... 6 Table 3 Distance and Direction to Class I and Class II Areas of Interest ...... 10 Table 4 National Ambient Air Quality Standards ...... 13 Table 5 Allowable Increments for Class I and Class II Areas ...... 15 Table 6 Project Phases and Time Frames ...... 18 Table 7 Stationary Source Maximum Annual Emissions Summary ...... 21 Table 8 Stationary Source Maximum Daily Emissions Summary ...... 22 Table 9 Fugitive Dust Source Maximum Annual Emissions Summary ...... 23 Table 10 Fugitive Dust Source Maximum Daily Emissions Summary ...... 24 Table 11 Tailpipe Source Maximum Annual Emissions Summary ...... 25 Table 12 Tailpipe Source Maximum Daily Emissions Summary ...... 25 Table 13 Project Maximum Annual Emissions Summary ...... 26 Table 14 Project Maximum Daily Emissions Summary ...... 26 Table 15 Project Annual Emissions ...... 27 Table 16 Project Maximum Daily Emissions by Year ...... 28 Table 17 Modeled Source Summary Description ...... 30 Table 18 Example of Model Input for Point Sources ...... 31 Table 19 Example of Model Input for Volume Sources ...... 32 Table 20 Example of Model Input for Line Sources...... 32

ii Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 21 Example of Model Input for Area Sources ...... 32 Table 22 Summary of Modeled Point, Volume, Line, and Area Sources ...... 33 Table 23 Receptor Grid Spacing ...... 35 Table 24 Particle Size Distribution ...... 39 Table 25 Nearby Background Source Summary ...... 40 Table 26 Monitored Background Concentrations Used in the Modeling ...... 41 Table 27 Highest 24-Hour PM10 Concentrations by Month and Season ...... 42 Table 28 Mean Seasonal Hour 3rd Highest NO2 Concentrations for Price ...... 46 Table 29 Mean Temperature and Precipitation Summary for Black Rock ...... 48 Table 30 Extreme Temperature and Precipitation Summary for Black Rock ...... 48 Table 31 Regional Air Quality Data ...... 50 Table 32 CPM Air Quality Monitoring Data, August 2013 to July 2014 ...... 53 Table 33 Temperature Summary for the Sevier Playa Meteorological Station ...... 53 Table 34 100-Year AR4 Global Warming Potential ...... 59 Table 35 U.S. GHG Emissions by Economic Sector ...... 59 Table 36 U.S. GHG Emissions and Sinks ...... 59 Table 37 U.S. SO2 Emissions...... 61 Table 38 Applicant Committed Design Features, Air Quality ...... 63 Table 39 Comparison of Maximum Project Concentrations to the NAAQS ...... 68 Table 40 Comparison of Project Concentrations with PSD Increments ...... 78 Table 41 Comparison of Project Concentrations to PSD Increments on the Fishlake National Forest ...... 81 Table 42 AQRV Screening Analysis ...... 81 Table 43 Summary of VISCREEN Level 2 Meteorological Parameters ...... 85 Table 44 VISCREEN Level 2 Results for Year 2025 Daily Maximum Emissions ...... 86 Table 45 Maximum Annual GHG Emissions ...... 87 Table 46 Historic and Current Greenhouse Gas Atmospheric Concentrations ...... 89 Table 47 Comparison of Total Cumulative Concentrations to the NAAQS ...... 96 Table 48 Comparison of Highest 10 Project-Only Concentrations (1-hour NO2) with Total Cumulative Emissions above the NAAQS ...... 99

Figures Figure 1 Air Quality Analysis Area ...... 11 Figure 2 Modeled Receptor Grid ...... 37 Figure 3 Monitoring Station Location ...... 43 Figure 4 Annual Wind Rose ...... 55 Figure 5 Seasonal Wind Roses...... 57 Figure 6 Project-Only 1-Hour NO2 Concentration (with background) ...... 69 Figure 7 Project-Only 24-Hour PM10 Concentration (with background)...... 73 Figure 8 Distance Ring of 30-km from Project Boundary ...... 75 Figure 9 Project-Only 24-Hour PM2.5 Concentration (with background) ...... 79 Figure 10 Visibility Screening ...... 83 Figure 11 Cumulative 1-Hour NO2 Concentrations (with background) ...... 97

iii Sevier Playa Potash Project Resource Report: Air Quality and Climate

Acronyms and Abbreviations

The following acronyms are abbreviations are used throughout this report.

AERMOD AMS EPA Regulatory Model AMS American Meteorological Society amsl Above Mean Sea Level AQCR Air Quality Control Region AQRV Air Quality Related Value AQS Air Quality System AR4 Fourth Assessment Report BACT Best Available Control Technology BLM Bureau of Land Management BMU Brine Mining Unit BPIPPRM Building Profile Input Program for Plume Rise Model Enhancement CAA Clean Air Act CEQ Council on Environmental Quality CFR Code of Federal Regulations

CH4 Methane CO Carbon Monoxide

CO2 Carbon Dioxide

CO2e Carbon Dioxide Global Warming Equivalent CPM Crystal Peak Minerals (Peak Minerals, Inc. dba Crystal Peak Minerals) CYr Calendar Year EIA Energy Information Administration EIS Environmental Impact Statement EPA Environmental Protection Agency FDCP Fugitive Dust Control Plan FLAG Federal Land Managers Air Quality Related Values Work Group FLM Federal Land Manager FR Federal Register ft Feet ft/s Feet Per Second GAQM Guideline on Air Quality Models GHG Greenhouse Gas g/cm3 Grams Per Cubic Centimeter g/s Grams Per Second

iv Sevier Playa Potash Project Resource Report: Air Quality and Climate g/s/m2 Grams Per Second Per Square Meter GWP Global Warming Potential HAP Hazardous Air Pollutant HFC Hydrofluorocarbon

HNO3 Nitric Acid IPP Intermountain Power Project ISR In-stack Ratio

K2SO4 Potassium Sulfate (Sulfate of Potash) km Kilometer kV Kilovolt lb/hr Pounds Per Hour m Meter MDAQMD Mojave Desert Air Quality Management District MERP Modeled Emission Rates for Precursor

MgCl2 Magnesium Chloride mmt Million Metric Tons MOVES Motor Vehicle Emissions Simulator MSA Metropolitan Statistical Area NAAQS National Ambient Air Quality Standards NaCl Sodium Chloride NEPA National Environmental Policy Act NED National Elevation Data NESHAP National Emission Standards for Hazardous Air Pollutants

NF3 Nitrogen Trifluoride NLCD National Land Cover Data NOAA National Oceanic and Atmospheric Administration NO Nitrogen Monoxide (or Nitric Oxide)

NOX Nitrogen Oxides

NO2 Nitrogen Dioxide

NO3 Nitrogen Trioxide

N2O Nitrous Oxide NSPS New Source Performance Standards NSR New Source Review NWS National Weather Service

O3 Ozone OLM Ozone Limiting Method

v Sevier Playa Potash Project Resource Report: Air Quality and Climate

Pb Lead PFC Perfluorocarbon PM Particulate Matter

PM2.5 Particulate Matter with a Diameter Less Than or Equal to 2.5 Microns

PM10 Particulate Matter with a Diameter Less Than or Equal to10 Microns POD Plan of Development ppb Parts per Billion by Volume ppm Parts per Million by Volume PSD Prevention of Significant Deterioration PVMRM Plume Volume Molar Ratio Method Project Sevier Playa Potash Project PYr Project Year ROW Right-of-Way

SF6 Sulfur Hexafluoride SIP State Implementation Plan SITLA State of Utah School and Institutional Trust Lands Administration SOP Sulfate of Potash

SO2 Sulfur Dioxide

SO4 Sulfate SR State Route tpy Tons (short) per Year UDAQ Utah Division of Air Quality UDEQ Utah Department of Environmental Quality UDOGM Utah Division of Oil, Gas, and Mining µg/m3 Micrograms per Cubic Meter UNFCCC United Nations Framework Convention on Climate Change USGRP U.S. Global Change Research Program USGS U. S. Geological Survey UTM Universal Transverse Mercator VMT Vehicle Miles Traveled VOC Volatile Organic Compound yd3 Cubic Yard

vi Sevier Playa Potash Project Resource Report: Air Quality and Climate

1.0 Introduction

The Sevier Playa is located in central Millard County, in southwestern Utah, approximately 130 miles southwest of Salt Lake City, between the towns of Delta (30 miles to the northeast) and Milford (25 miles to the south-southeast). The Sevier Playa is a large terminal lakebed that is normally dry on the surface and contains subsurface potassium-bearing saline brines. The brine resource, along with the meteorological and topographic conditions at the Sevier Playa make the site a viable location from which to produce potash and associated minerals (Bureau of Land Management [BLM] 1987). Potash is any soluble salt that contains potassium. Various types of potash fertilizer comprise the largest worldwide industrial use of the element potassium.

The BLM is preparing an Environmental Impact Statement (EIS) to analyze and disclose the environmental effects of the proposed Sevier Playa Potash Project (Project). This resource report describes the analysis area, regulatory framework, methods, affected environment, and analysis of effects for air quality and climate in support of the EIS for the Project.

2.0 Proposed Action and Alternatives

Crystal Peak Minerals (CPM) controls through agreement the rights to develop and operate potassium mineral leases on 117,814 acres of federal lands administered by the BLM and an additional 6,409 acres of potash leases on lands under the jurisdiction of the State of Utah School and Institutional Trust Lands Administration (SITLA) on and adjacent to the Sevier Playa. CPM proposes to exercise its lease rights by constructing and operating the Project, which would produce at its peak approximately 372,000 tons per year of potassium sulfate (K2SO4), also known as sulfate of potash (SOP), and related minerals. The annual average production over the 35-year lifetime of the Project would be about 328,500 tons, with a minimum annual production of approximately 246,000 tons.

2.1 Applicant Committed Design Features

When reviewing and considering whether to approve proposed projects, BLM’s approach is to first avoid, then minimize, and finally mitigate adverse effects. Applicant committed design features have been developed to avoid, minimize, or mitigate the potential adverse effects of the Project. Appendix K in the EIS lists these design features, which are integral to all of the action alternatives (including the proposed action). CPM would implement these design features regardless of which action alternative, or combination of alternatives, may be selected.

2.2 Supplemental Plans

CPM developed several supplemental plans to address specific resource issues or management requirements. Each of these plans supplements information and requirements in the EIS, the Mining Plan (CPM and Stantec 2019a), and the Plan of Development (POD) (CPM 2019a), and is incorporated in these documents by reference. These plans would also apply to the sale of mineral materials to CPM. Some of these plans contain applicant committed design features that CPM would implement in addition to the design features in Appendix K in the EIS. The analysis of effects in Section 7.0 considers the design features in the supplemental plans to be integral to the proposed action and action alternatives. These supplemental plans include:

• Adaptive Wildlife Management Plan (CPM 2019b)

• Blasting Plan (CPM 2019c)

1 Sevier Playa Potash Project Resource Report: Air Quality and Climate

• Cultural Resource Plan (CPM 2019d)

• Environmental Compliance Inspection Plan (2019e)

• Fugitive Dust Control Plan (CPM 2019f)

• Noxious and Invasive Weed Management Plan (CPM 2019g)

• Reclamation Plan (CPM 2019h)

• Site Safety Plan (CPM 2019i)

• Solid and Hazardous Waste and Hazardous Materials Management Plan (CPM 2019j)

• Spill Prevention, Control, and Countermeasures Plan (SPCC) (CPM 2019k)

• Stormwater Pollution Prevention Plan (SWPPP) (CPM 2019l)

• Transportation and Traffic Management Plan (CPM 2019m)

• Water Monitoring Plan (CPM 2019n)

2.3 Proposed Action

The proposed action is made up of three primary components:

1) Mining Project – Facilities that would be constructed and activities that would take place on leases controlled by CPM on or near the Sevier Playa as part of full commercial development of the potassium resource.

2) Rights-of-Way – Facilities that would be constructed and activities that would take place outside of leases controlled by CPM on rights-of-way (ROWs) issued by the BLM, along with equivalent agreements on state and private lands, to support full development of the potassium resource.

3) Mineral Materials – Sale of mineral materials to CPM by BLM and SITLA to support full development of the potassium resource.

The following sections summarize the components of the Mining Project, ROWs, and Mineral Material sales. It is important to note that some Project components would be divided into on-lease and off-lease portions. For example, the 69-kilovolt (kV) Power and Communication Line would be located primarily in a ROW; however, about two miles of the line would be located in the lease area. Additional details of the proposed action are provided in Appendix L in the EIS. The description of the proposed action represents the best available information, based on the Mining Plan (CPM and Stantec 2019a), POD (CPM 2019a), and Gravel Pit Mining Plan (CPM and Stantec 2019b). CPM is continuing work on additional engineering and refinement of processes concurrently with development of the EIS. Detailed engineering may lead to changes to the descriptions of facilities, activities, and processes described in the EIS. BLM will review these changes, determine the adequacy of the analysis of effects in the EIS, and conduct any additional NEPA analysis required.

2 Sevier Playa Potash Project Resource Report: Air Quality and Climate

2.3.1 Mining Project

During operation of the Mining Project, potassium-bearing brines would be extracted from trenches and wells on the Sevier Playa. The brine would be routed through a series of ditches and ponds, using solar evaporation to concentrate the brine. Key components of the Mining Project (Table 1) would include:

• The playa has been divided into Brine Mining Units (BMUs) based on recent exploration activities and analysis in the Feasibility Study (CPM 2018). Each BMU consists of portions of the extraction and recharge systems.

• Extraction trenches and canals would be excavated to allow for gravity drainage of brine from the playa. Extraction wells with solar-powered pumps would also contribute to brine extraction.

• Water diverted from the Sevier River would provide the majority of recharge water. CPM would acquire (lease or purchase) water from upstream users to supplement natural flows in the river. A berm constructed across the Sevier River near the playa inlet would divert river water through a canal into the recharge system.

• Recharge canals, collectors, and trenches would be excavated to recharge the shallow brine aquifer on the playa and promote consistent brine production. Pump stations would maintain the flow of water in the recharge canals.

• Evaporation ponds, including preconcentration and production ponds, would be constructed on the playa. The preconcentration ponds would concentrate the brine causing halite (NaCl, sodium chloride, also known as table salt) and other non-commercial salts to precipitate. These salts would be stored in the preconcentration ponds. A combination of pump stations and weirs would provide for brine flow through the preconcentration ponds.

• Additional pump stations would convey the saturated brine via the Brine Transfer Canal from the preconcentration ponds to the production ponds for further evaporation, causing potassium-rich salts to precipitate. A combination of pump stations and weirs would provide for brine flow in and around the production ponds. The production ponds would be harvested year-round, with the potassium-rich salts moved directly to the Processing Facility for processing into SOP.

• A Processing Facility would be located adjacent to the southern end of the playa on a parcel leased by CPM from SITLA. The Processing Facility would be contained within a fenced yard and would include three main structures (a wet plant, a dry plant, and a compaction building / bagging plant) and other support facilities. An administration building would provide office space. A communication tower would support telephone and data communication. SOP would be trucked to the Rail Loadout Facility for distribution.

• A Waste Product Storage Area would consist of a Purge Brine Storage Pond and a Tailings Storage Area surrounded by containment berms and access roads. Purge brine containing primarily magnesium chloride (MgCl2) would be removed from the production ponds and piped to a Purge Brine Storage Pond before harvesting. Process by-products (solid tailings) from the Processing Facility would be trucked to the Tailings Storage Area.

• A 69-kV Power and Communication Line would provide power for the Project.

• A 25-kV Power Line would provide power to pump stations around the preconcentration ponds.

3 Sevier Playa Potash Project Resource Report: Air Quality and Climate

• A 12.47-kV Power Line would provide power to pump stations around the production ponds, along the recharge canals, and along the Brine Transfer Canal and Pipeline.

• A 12.47-kV Power and Communication Line would provide power and communications from the Processing Facility to the Rail Loadout Facility as well as power for the water supply wells.

• A Natural Gas Pipeline would provide natural gas to the Processing Facility.

• A Water Supply Pipeline would transmit water from the water supply wells to the Processing Facility.

• A Perimeter Road would the constructed around the perimeter of the playa, with Perimeter Road Spurs from off-lease access roads, to provide access to Project facilities. A haul road would connect the Processing Facility to the Perimeter Road, with haul road spurs to the production ponds and Waste Product Storage Area.

• Monitoring wells would be constructed for monitoring of the potential effects of the Project on groundwater. The Monitoring Well Access Road would be used to access some of these wells. Other existing and proposed roads would access the remaining wells.

Table 1 Mining Project Summary

Ownership Number BLM State Total Total of Length Area Length Area Length Area Facility Type Features (miles) (acres) (miles) (acres) (miles) (acres) Extraction System Extraction Trenches 159 294.03 n/a A 12.49 n/a A 306.52 n/a A Extraction Canal 1 25.12 n/a A 0.00 n/a A 25.12 n/a A BLM 2,264 n/a n/a n/a n/a n/a n/a Extraction Wells State 102 n/a n/a n/a n/a n/a n/a Recharge System West Recharge Canal 1 33.80 n/a A 3.95 n/a A 37.76 n/a A East Recharge Canal 1 18.26 n/a A 1.55 n/a A 19.81 n/a A Recharge Collectors 152 32.92 n/a A 2.62 n/a A 35.54 n/a A Recharge Trenches 155 272.09 n/a A 8.68 n/a A 280.76 n/a A Diversion Berm 1 n/a 0.4 n/a 0.0 n/a 0.4 Diversion Canal 1 0.28 4.3 0.00 0.0 0.28 4.3 Evaporation Ponds Preconcentration Ponds 11 n/a 15,372.6 n/a 0.0 n/a 15,372.6 Brine Transfer Canal / Pipeline 1 22.03 267.0 1.67 20.2 23.69 287.2 Production Ponds 18 n/a 2,272.9 n/a 416.7 n/a 2,689.6 Processing and Waste Storage Facilities Processing Facility 1 n/a 0.0 n/a 47.7 n/a 47.7 Purge Brine Storage Pond 1 n/a 800.5 n/a 0.0 n/a 800.5 Tailings Storage Area 1 n/a 461.7 n/a 0.0 n/a 461.7

4 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 1 Mining Project Summary

Ownership Number BLM State Total Total of Length Area Length Area Length Area Facility Type Features (miles) (acres) (miles) (acres) (miles) (acres) Utility Lines 69-kV Power and Communication Line 1 2.01 24.4 0.15 1.8 2.15 26.1 25-kV Power Line 1 11.09 127.7 0.00 0.0 11.09 127.7 12.47-kV Power Line 1 18.14 208.9 5.24 60.4 23.39 269.3 12.47-kV Power and Communication Line 1 0.52 6.0 0.15 1.7 0.67 7.7 Natural Gas Pipeline 1 1.99 12.1 0.16 1.0 2.15 13.0 Water Supply Pipeline 1 0.49 3.0 0.11 0.7 0.60 3.6 Access Roads Perimeter Road 1 53.26 516.5 6.85 66.4 60.11 582.9 Perimeter Road Spurs 6 4.03 39.1 0.52 5.0 4.55 44.1 Haul Road and Spurs 2 0.04 0.2 0.45 3.1 0.48 3.4 CPM Spur Road 1 0.30 2.2 0.06 0.5 0.36 2.6 Monitoring Wells Monitoring Wells 12 n/a 2.8 n/a 0.0 n/a 2.8 Monitoring Well Access Road 1 0.64 1.9 0.0 0.0 0.64 1.9 Notes: All lengths have been rounded to the nearest hundredth of a mile and areas have been rounded to the nearest tenth of an acre. Totals may not appear exact because of rounding. n/a: Not applicable to this feature. A The areas for the extraction and recharge systems have not been calculated. For the analysis of effects, it is assumed that the entire lease area inside the Perimeter Road would be disturbed. The majority of the extraction and recharge systems, except the Sevier River Diversion, would be located within this disturbed area. B Area calculated using the ROW width for the off-lease portion of these features. For features that are entirely on- lease, widths were determined as follows: Perimeter Road Spurs – same as Perimeter Road; Haul Road and Spurs – as listed in Mining Plan; CPM Spur Road – same as Rail Loadout Facility Access Roads.

2.3.2 Rights-of-Way

CPM has applied for ROW grants to use BLM-administered lands for the construction, operation, maintenance, and decommissioning of utilities and other facilities associated with the Project (Table 2). CPM would complete similar agreements for use of state and private lands for these facilities. These Project components would be located outside of the potassium leases controlled by CPM, but are integral to successful development and operation of the Mining Project. Key off-lease Project components would include:

• A 69-kV Power and Communication Line to provide electrical power and communications for the Project, along with use of the existing Power Line Access Road and several temporary Power Line Access Road spurs.

• A 25-kV Power Line connecting with the on-lease portion of the line, with an associated access road, and the North Playa substation connecting to the 69-kV Power and Communication Line.

5 Sevier Playa Potash Project Resource Report: Air Quality and Climate

• A 12.47-kV Power Line would provide power to pump stations around the production ponds, along the recharge canals, and along the Brine Transfer Canal and Pipeline.

• A 12.47-kV Power and Communication Line to supply electricity and communications to the Rail Loadout Facility, and electricity to the power line spurs to the water supply wells.

• Temporary and permanent communication towers to support Project communications.

• A propane tank at the Rail Loadout Facility to supply energy needs for the early phases of the Project.

• A Natural Gas Pipeline to meet long-term energy needs at the Processing and Rail Loadout Facilities including access roads for construction use. A portion of this pipeline may be constructed aboveground to avoid adverse effects to springs.

• A Rail Loadout Facility, Rail Spur, and Access Corridor to support shipment of products by rail.

• Water supply facilities, including water supply wells, access roads, power line spurs, and water pipelines from the wells to the Processing Facility, to support the Project’s needs for fresh water.

• Use of existing, improved, or new roads to access the Perimeter Road and other Project facilities, along with off-lease segments of the Perimeter Road.

• Portions of the preconcentration ponds and associated pump stations would be located outside the lease area, but still within the playa boundary.

• Several segments of the recharge canals, recharge collectors, and Brine Transfer Canal would be constructed off-lease, generally parallel to the off-lease segments of the Perimeter Road.

• Monitoring wells would be constructed for monitoring of the potential effects of the Project on groundwater. The Monitoring Well Access Road would be used to access some of these wells. Other existing and proposed roads would access the remaining wells.

Table 2 Right-of-Way Summary

Ownership BLM State Private Total Total Length Area Length Area Length Area Length Area Facility Type (miles) (acres) (miles) (acres) (miles) (acres) (miles) (acres) Temporary ROWs Power and Communication Lines 25.25 174.8 0.89 15.3 -- -- 26.14 190.1 Communication Facilities 3.66 11.2 1.72 5.2 -- -- 5.38 16.4 Natural Gas Facilities 25.95 62.9 1.10 2.7 1.07 2.6 28.12 68.2 Rail Facilities 2.39 14.6 -- -- 1.08 7.9 3.48 22.5 Water Supply Facilities 12.20 41.7 1.30 5.5 -- -- 13.50 47.2 Access and Perimeter Roads 12.40 30.1 1.18 2.9 -- -- 13.58 32.9 Preconcentration Ponds -- 13.7 ------13.7 Recharge System 10.29 25.1 1.06 2.6 -- -- 11.35 27.7

6 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 2 Right-of-Way Summary

Ownership BLM State Private Total Total Length Area Length Area Length Area Length Area Facility Type (miles) (acres) (miles) (acres) (miles) (acres) (miles) (acres) Brine Transfer System ------Monitoring Wells -- 1.8 ------1.8 Total Temporary ROWs 92.14 375.9 7.25 34.1 2.16 10.5 101.55 420.5 Permanent ROWs Power and Communication Lines 94.57 709.9 7.97 75.7 -- -- 102.54 785.6 Communication Facilities 0.62 2.3 ------0.62 2.3 Natural Gas Facilities 38.94 133.7 1.96 6.6 4.05 12.9 44.95 153.3 Rail Facilities 4.21 151.1 -- -- 2.16 9.8 6.37 160.9 Water Supply Facilities 14.45 57.3 1.98 8.6 -- -- 16.44 65.8 Access and Perimeter Roads 32.30 150.8 2.72 13.3 -- -- 35.02 164.0 Preconcentration Ponds -- 2,338.6 ------2,338.6 Recharge System 10.29 149.6 1.06 15.5 -- -- 11.35 165.1 Brine Transfer System 0.52 6.3 ------0.52 6.3 Monitoring Wells 6.50 19.8 ------6.50 19.8 Total Permanent ROWs 202.39 3,719.3 15.69 119.6 6.21 22.8 224.30 3,861.8 Note: All lengths have been rounded to the nearest hundredth of a mile and areas have been rounded to the nearest tenth of an acre. Totals may not appear exact because of rounding. --: Indicates this type of feature does not occur on this ownership.

2.3.3 Mineral Materials

CPM estimates that 250,000 cubic yards (yd3) of aggregate (gravel and similar materials) would be needed over the life of the Project, primarily during construction (CPM and Stantec 2019b). This estimate does not include about 50,000 yd3 of railroad ballast and sub-ballast, which would be purchased from a commercial source. One proposed source (gravel pit) would be located on BLM-administered lands on the north side of Crystal Peak Road approximately eight miles west of the State Route (SR) 257. The other two gravel pits would be located near the Processing Facility in the lease area.

2.3.4 Construction

Not all of the facilities would be needed initially; therefore, CPM has proposed phased construction to defer capital expenses and bring the facilities online as they are needed. The construction phase would generally include the first four years of the Project. During this period, facilities required to be in operation prior to the startup of the Processing Facility would be constructed, including many of the extraction and recharge trenches and collectors, the extraction canal, most of the recharge canal (including the Sevier River diversion), the evaporation ponds and pump stations, initial stages of the Waste Product Storage Area, the Perimeter Road and spurs, 69-kV Power and Communication Line, the 12.47-kV Power and Communication Line (from the Processing Facility to Water Supply Well 4 Access Road), the communication towers, the water supply facilities, most of the access roads, and the Processing Facility. Different facilities may be constructed concurrently, using multiple crews specializing in various

7 Sevier Playa Potash Project Resource Report: Air Quality and Climate components of the Project. Various phases of construction would occur at different locations throughout the process. In some cases, a particular phase could be carried out concurrently at a number of locations. Following construction of each facility, interim reclamation would address temporary disturbance as described in the Reclamation Plan (CPM 2019h).

2.3.5 Operation and Maintenance

The operation phase would begin at the end of the construction phase, once the Processing Facility is in operation. Although the focus would be on operation and maintenance, some facilities would be constructed or expanded during this phase. This would include development of additional extraction and recharge trenches, extension of the extraction and recharge canals, development of the extraction wells, expansion of the Waste Product Storage Area, maintenance of the evaporation ponds (including berm raises for the preconcentration ponds), construction of the Rail Loadout Facility and Rail Spur, extension of the 12.47-kV Power and Communication Line, construction of the 25-kV Power Line, and construction of the Natural Gas Pipeline. After construction, routine maintenance of Project facilities would be necessary to optimize performance and to detect and repair malfunctions. Routine maintenance activities may include selective vegetation clearing, blading, resurfacing, dust abatement, spot repairs, culvert cleaning, noxious weed control, reseeding, regrading, snow removal, and repair, upgrades, or replacement of support structures. Operation and maintenance of the Project, including on- and off-lease facilities, would require approximately 175 full-time employees, distributed among on-playa operations, the Processing Facility, drivers for transport of SOP to the Rail Loadout Facility, operation of the Rail Loadout Facility, and miscellaneous off-playa maintenance and operations tasks. The majority of the employees would be full-time over the calendar year and throughout the anticipated life of the Project.

2.3.6 Decommissioning and Reclamation

When the Project is at the end of its useful life, CPM would prepare and implement a Decommissioning Plan (to be approved by the BLM and the Utah Division of Oil, Gas, and Mining [UDOGM]) that would provide specific details and a schedule regarding how and when decommissioning of the Project would be accomplished. CPM would be required to post surety bonds in accordance with 43 CFR 3504.50 (for the BLM) and UAC Rule R647-1 (for UDOGM). BLM would consult with interested parties, including UDOGM and other agencies, to determine if any facilities should be retained for alternate uses. Any facilities not decommissioned would become the responsibility of an entity other than CPM. The final disposition of facilities would be approved by BLM and UDOGM. In general, decommissioning would involve disassembling infrastructure and salvaging valuable equipment. Demolition or removal of equipment and facilities would meet applicable environmental, health, and safety regulations. Following facility removal, the site would undergo final cleanup and reclamation. Foundations and access roads would be removed, re-contoured, and reseeded, as appropriate. Areas disturbed during removal of facilities would be reclaimed and rehabilitated as near as possible to their original condition and would be available for the same uses that existed prior to the Project. Fences and other previously existing structures would be reestablished to as good a condition or better than the original. CPM has prepared a Reclamation Plan (CPM 2019h) for the Project, which contains more detail on specific reclamation activities.

2.4 Alternatives

The BLM considered a number of alternatives to determine if they would substantially reduce or eliminate resource effects, otherwise address unresolved conflicts, or result in maximum recovery of the potassium resource. BLM also considered whether the alternatives would meet the purpose and need of the Project and solicited information from CPM on their economic and technical feasibility. Based on the technical and economic feasibility of each of the alternatives, along with environmental factors, and legal

8 Sevier Playa Potash Project Resource Report: Air Quality and Climate and regulatory constraints, BLM identified five action alternatives for detailed analysis (Section 2.1.3 in the EIS).

The alternatives carried forward for detailed analysis are presented as variations of specific Project components, rather than re-iterations of the entire Project in which only certain components are changed. If one or more of these alternatives were to be selected in the Record of Decision, the components of the selected alternative(s) would replace the corresponding components in the proposed action, while the remainder of the proposed action would be implemented as described above. The action alternatives analyzed in detail are described in Section 2.5 in the EIS and illustrated in Figures 2.5-1 through 2.5-6 in the EIS. The action alternatives analyzed in detail are summarized as follows:

• Alternative 1 would replace the northern portion of the proposed action for the 69-kV Power and Communication Line from the Black Rock Substation to the intersection of the SR 257 Cutoff Road and the Power Line Access Road. The purpose of this alternative would be to minimize new disturbance in previously undisturbed areas and minimize habitat fragmentation by following existing disturbance corridors.

• Alternative 2 would replace the southern portion of the proposed action for the 69-kV Power and Communication Line from the point where the proposed action leaves the Power Line Access Road and runs west toward the Processing Facility. The purpose of this alternative would be to minimize new disturbance in previously undisturbed areas and minimize habitat fragmentation by following existing disturbance corridors.

• Alternative 3 would replace the portion of the proposed action for the Natural Gas Pipeline between SR 257 on the east and the Rail Loadout Facility on the west. The purpose of this alternative would be to provide a route for the Natural Gas Pipeline that is entirely on BLM- administered land and avoids crossing private lands.

• Alternative 4 would replace the western portion of the proposed action for the Natural Gas Pipeline from the point where the pipeline leaves Crystal Peak Road and heads northwest, then west toward the Processing Facility. The purpose of this alternative would be to minimize new disturbance in previously undisturbed areas and minimize habitat fragmentation by following existing disturbance corridors.

• Alternative 5 would be an alternative method of diverting flows from the Sevier River into the recharge system. The purpose of this alternative would be to place the diversion within the boundary of the playa, minimizing effects to riparian vegetation, wildlife habitat, and cultural resources that may be present at the location of the diversion in the proposed action.

Council on Environmental Quality (CEQ) regulations (40 CFR 1502.14) require analysis of a no-action alternative. The no-action alternative provides a means of comparing the potential effects of the action alternatives (including the proposed action) against the baseline conditions in the analysis area in the absence of the proposed action (in this case, the Project). The potassium leases controlled by CPM provide it with the exclusive right to extract potassium and associated minerals on lands leased from BLM and SITLA on and around the Sevier Playa, subject to the terms and conditions in the leases. It also gives CPM the right to use the surface of the leased land as needed for the development of the potassium resource. A potassium lease is not cancellable except by due process in cases where the lessee does not meet the terms and conditions of the lease. Thus, the no-action alternative does not imply that the leases controlled by CPM would never be developed, only that they would not be developed as proposed in the Mining Plan (CPM and Stantec 2019a), the POD (CPM 2019a), the Gravel Pit Mining Plan (CPM and Stantec 2019b), or the action alternatives evaluated in detail in the EIS. Selection of the no-action

9 Sevier Playa Potash Project Resource Report: Air Quality and Climate alternative would not preclude mining of the potassium resource in the future, which would require submittal of a new Mining Plan, POD, and Gravel Pit Mining Plan, as well as completion of a new NEPA process. 3.0 Analysis Area

The analysis area for direct, indirect, and cumulative effects includes a zone extending approximately 30 kilometers (km) (19 miles) in all directions from the Project’s ambient air boundary (Figure 1). The area falls under a near-field analysis classification, as defined by the U.S. Environmental Protection Agency (EPA) in 40 Code of Federal Regulations (CFR) Part 51 Appendix W, also known as the Guideline on Air Quality Models (GAQM) (EPA 2017a). Figure 1 depicts the analysis area in relation to the Project and general region.

The analysis of effects also included seven National Parks and one National Forest identified as Class I and Class II areas of interest (see Section 4.2 for general discussion of Class I and Class II areas of interest) located in southwestern Utah, western Nevada, and northern Arizona. These areas are listed in Table 3 and are located outside the analysis area, greater than 50 km (31 miles) from the Project. The closest Class I area is Zion National Park at about 135 km (84 miles) south of the center of the Sevier Playa, while the closest Class II area of interest is the Fishlake National Forest, approximately 57 km (35 miles) east.

Table 3 Distance and Direction to Class I and Class II Areas of Interest

Area Distance (km / miles) Direction Class I Zion National Park, Utah 135 / 84 S Bryce Canyon National Park, Utah 144 / 89 SSE Capitol Reef National Park, Utah 149 / 93 ESE Canyonlands National Park, Utah 248 / 154 E Grand Canyon National Park, Arizona 248 / 154 SE Arches National Park, Utah 285 / 177 E Class II Areas of Interest Fishlake National Forest, Utah 57 / 35 E Great Basin National Park, Nevada 86 / 53 W

10 Air Quality Analysis Area

Source: Modified Figure A1 from Ramboll (2019a) Sevier Playa Potash Project Resource Report: Air Quality and Climate

THIS PAGE INTENTIONALLY LEFT BLANK

12 Sevier Playa Potash Project Resource Report: Air Quality and Climate

4.0 Regulatory Framework

The federal government has established an extensive regulatory program to govern and control air pollution from facilities. This program includes the National Ambient Air Quality Standards (NAAQS), New Source Review (NSR) regulations, New Source Performance Standards (NSPS) regulations, National Emission Standards for Hazardous Air Pollutants (NESHAP) regulations, and the Federal Operating Permit Program (Title V) regulations. Which regulations apply to a facility depends on the type of facility, the air pollutants emitted, the amount of air pollutants emitted, the types of sources, and other factors. Air pollution and air quality may also be limited by local, state, and tribal air quality regulations and standards, and state implementation plans (SIPs) established under the federal Clean Air Act (CAA). In Utah, air pollution is managed by the Utah Department of Environmental Quality (UDEQ) / Utah Division of Air Quality (UDAQ), under the Utah Air Conservation Act (Title 19, Chapter 2 of the Utah Code) and the SIP. Title 19 addresses the air permitting program required for sources operating in Utah.

4.1 Ambient Air Quality Standards

Section 108 of the CAA required EPA to develop a list of pollutants that would “cause or contribute to air pollution which may be anticipated to endanger public health or welfare and the presence of which in the ambient air results from numerous or diverse mobile or stationary sources”. The air pollutants that EPA developed as a result of this directive are known as “criteria pollutants” and are carbon monoxide (CO), lead (Pb), nitrogen dioxide (NO2), ozone (O3), particulate matter (PM) with a diameter less than or equal to 10 microns (PM10), particulate matter with a diameter less than or equal to 2.5 microns (PM2.5), and sulfur dioxide (SO2). EPA developed NAAQS for these pollutants, with the current standards (as of 2018) listed in Table 4 in units of parts per million by volume (ppm), parts per billion by volume (ppb), or micrograms per cubic meter of air (μg/m3). Two types of standards have been developed: “primary” and “secondary”. Primary standards are human health-based standards designed to protect all populations, including sensitive ones, while secondary standards are to protect the public welfare (effects on soil, vegetation, etc.).

Per the CAA, the EPA has developed classifications for distinct geographic regions known as Air Quality Control Regions (AQCRs) and for major Metropolitan Statistical Areas (MSAs). For each federal criteria pollutant, every AQCR or MSA (or portion) is designated as “attainment”, “non-attainment”, or “unclassified”. Attainment means the ambient air concentration level for the individual pollutant and averaging period is below the applicable NAAQS; non-attainment means the pollutant ambient air concentration level exceeds the NAAQS; and unclassified means that available data, if any, are insufficient to make an attainment determination. Millard County, where the Project would be located, is presently designated as unclassified / attainment for all pollutants and averaging periods.

Table 4 National Ambient Air Quality Standards

Primary / Averaging Concentration Pollutant Secondary Time Level Form 9 ppm 8-hour Carbon Monoxide (10,000 μg/m3) Not to be exceeded more than once Primary (CO) 35 ppm per year 1-hour (40,000 μg/m3) Primary and Rolling 3- Lead (Pb) (1) 0.15 μg/m3 Not to be exceeded Secondary month average

13 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 4 National Ambient Air Quality Standards

Primary / Averaging Concentration Pollutant Secondary Time Level Form Primary and 53 ppb Annual Annual mean Secondary (100 μg/m3) Nitrogen Dioxide 98th percentile of 1-hour daily (NO2) 100 ppb Primary 1-hour maximum concentrations, averaged (188 μg/m3) over 3 years Annual fourth-highest daily (2) Primary and 0.070 ppm Ozone (O3) 8-hour maximum 8-hour concentration, Secondary (147 μg/m3) averaged over 3 years Primary Annual 12 μg/m3 Annual mean, averaged over 3 years Secondary Annual 15 μg/m3 Annual mean, averaged over 3 years PM2.5 Particle Primary and 98th percentile, averaged over 3 24-hour 35 μg/m3 Pollution Secondary years

Primary and 3 Not to be exceeded more than once PM10 24-hour 150 μg/m Secondary per year on average over 3 years 99th percentile of 1-hour daily 75 ppb Primary 1-hour maximum concentrations, averaged (196 μg/m3) over 3 years 0.5 ppm Not to be exceeded more than once Sulfur Dioxide Secondary 3-hour (3) 3 (SO2) (1300 μg/m ) per year 0.14 ppm Primary 24-hour Revoked in 2010 (4) (365 μg/m3) 0.03 ppm Primary Annual Revoked in 2010 (4) (80 μg/m3) (1) Final rule signed October 15, 2008. The 1978 lead standard (1.5 µg/m3 as a quarterly average) remains in effect until one year after an area is designated for the 2008 standard, except that in areas designated nonattainment for the 1978 standard, the 1978 standard remains in effect until implementation plans to attain or maintain the 2008 standard are approved. (2) Effective December 28, 2015. The previous rule signed March 12, 2008 was 0.075 ppm, and this standard remains in effect in some areas. Revocation of the 2008 standard and the transition to the 2015 standard are addressed in the implementation rule for the 2015 standard. (3) Final rule signed June 2, 2010. The 1971 annual and 24-hour SO2 standards were revoked in that same rulemaking. However, these standards remain in effect until one year after an area is designated for the 2010 standard, except in areas designated nonattainment for the 1971 standards. The 1971 standards remain in effect until implementation plans to attain or maintain the 2010 standard are approved. (4) Listed for informational purposes.

4.2 New Source Review / Prevention of Significant Deterioration

An entity planning to construct a new facility, or modifying an existing facility, must first go through the New Source Review (NSR) permitting process. In Utah, the entity applies for an Approval Order from UDAQ for the facility by completing an air permit application. As part of the NSR permit application, the facility must demonstrate compliance with the NAAQS. This can be done via computer-based air dispersion modeling or other methods approved by the UDAQ Administrator. The entity will typically use a model to predict ambient air concentrations from facility emissions. If the predicted effects are below the NAAQS and other applicable standards, then compliance has been demonstrated for the new or

14 Sevier Playa Potash Project Resource Report: Air Quality and Climate modified facility. Once all state requirements are met, the UDAQ grants an Approval Order and the facility or modification can be constructed.

The federal Prevention of Significant Deterioration (PSD) regulation, 40 CFR 52.21 (EPA 2017b), is intended to prevent deterioration of air quality in areas that are in attainment with the NAAQS. The CAA requires EPA to designate each air quality control region within the United States as one of three PSD area classifications: Class I, Class II, or Class III. Class I is the most restrictive air quality category while Class III is the least restrictive.

Mandatory federal Class I areas were designated by Congress and include international parks, national wilderness areas greater than 5,000 acres in size, national memorial parks greater than 5,000 acres in size, and national parks greater than 6,000 acres in size that were in existence on August 7, 1977 (40 CFR 52.21(e)). These classifications may not be re-designated. In addition to ambient air quality, the federal CAA also provides for specific visibility protection of mandatory federal Class I areas (see Section 4.5).

All areas not established as Class I were designated as Class II, which allows a relatively greater deterioration of air quality over that in existence in 1977, although still within the NAAQS. Federal Land Managers (FLMs) have also identified certain federal assets as Class II areas of interest to better understand the impacts to air quality and Air Quality Related Values (AQRVs) that may occur at these locations. No Class III areas have been designated.

The PSD regulation prevents deterioration of air quality in attainment areas by establishing maximum allowable increases (increments) in the ambient concentration of the pollutants NO2, SO2, PM10, and PM2.5 for Class I and Class II areas. Table 5 lists the Class I and Class II increments, showing that the allowed increases in air concentration is much more restrictive for Class I areas than Class II areas (40 CFR Part 52.21(c)).

Table 5 Allowable Increments for Class I and Class II Areas

Class I Increment Class II Increment Pollutant Averaging Period Level (μg/m3) Level (μg/m3)

NO2 Annual 2.5 25 Annual arithmetic mean 2 20

SO2 24-hr maximum 5 91 3-hr maximum 25 512 Annual arithmetic mean 4 17 PM10 24-hr maximum 8 30 Annual arithmetic mean 1 4 PM2.5 24-hr maximum 2 9 Source: 40 CFR 52.21(c)

Future development projects that have the potential to emit more than 250 tons per year (tpy) of any criteria pollutant, or that have the potential to emit more than 100 tpy if listed under 40 CFR 52.21(b)(1)(i), are required to undergo an increment consumption analysis under the PSD permitting regulations. Fugitive emissions, which are emissions that are not reasonably passed through a stack, chimney, or vent, are typically not included in the sum for the threshold when making a major source determination. However, fugitive emissions are counted toward the threshold for a specific set of source

15 Sevier Playa Potash Project Resource Report: Air Quality and Climate categories, including those sources for which the major source threshold is 100 tpy, as well as other specifically regulated sources listed in 40 CFR Part 52.21(b)(1)(iii).

Sources subject to PSD review and permitting must apply Best Available Control Technology (BACT). During the PSD permitting process, a BACT analysis is performed for the proposed construction or modification. The BACT process evaluates possible control technologies for the proposed action based on technical feasibility and economic reasonability. Decisions about which technology should be applied are made on a case-by-case basis and are mandated through the permit.

4.3 New Source Performance Standards / National Emission Standards for Hazardous Air Pollutants

The NSPSs, listed in 40 CFR Part 60, were established by Section 111 of the CAA, and adopted by reference in Title 19, Chapter 2 of the Utah Code. These federal standards establish emission limits that apply to various categories of new, modified, or reconstructed stationary sources, as well as existing sources, depending on the situation. These regulations require sources to implement best-demonstrated emission control technology. Additional notification, monitoring, and best management practice requirements may also apply. The NSPSs are listed for specific processes or facility types by individual subparts in the rule.

The NESHAPs, listed in 40 CFR Part 63, are stationary source standards for hazardous air pollutants (HAPs). These pollutants are known or suspected to cause cancer, other serious health effects (for example, reproductive effects or birth defects), or adverse environmental effects. These regulations apply to new, modified, or reconstructed sources, as well as existing sources, depending on the situation. Sources subject to NESHAPs are required to have specified pollutant controls and work practice standards. Initial performance tests to demonstrate compliance are required. For continuous compliance, sources are generally required to monitor control device operating parameters established during the initial performance test. Sources may also be required to install and operate continuous emission monitors to demonstrate compliance. The NESHAPs are listed for specific processes or facility types by individual subparts in the rule.

4.4 Federal Operating Permit (Title V)

Major sources of air pollutants must obtain a federal operating permit (40 CFR Part 70, EPA 2017c). Under this regulation, a “major source” is a facility that emits over 100 tpy of any criteria pollutant, 25 tpy of combined HAPs, or 10 tpy of an individual HAP. Fugitive emissions are counted towards major source thresholds for Title V if the facility is one of the same listed source categories as in the PSD regulations. The operating permit compiles all applicable air quality requirements for a facility and requires proof of compliance in the form of testing, monitoring, reporting, and recordkeeping. In Utah, this program is administered by the UDAQ.

4.5 Air Quality Related Values

An air quality related value (AQRV) is a resource that may be adversely affected by a change in air quality. The resources are specific scenic, cultural, physical, biological, ecological or recreational assets located in Class I areas. AQRVs can also be applied to Class II areas of interest by agency determination. AQRVs address effects on visibility, vegetation, soils, and surface water. AQRV effects are usually only evaluated for major sources regulated under the PSD program; however, for NEPA disclosure purposes, agencies may evaluate effects from minor sources.

16 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Visibility is an AQRV because observing scenic vistas in Class I and Class II areas of interest is an important feature of these natural areas. Regional haze is visibility impairment that can hamper these views. Regional haze is caused by the accumulation of air pollutant emissions and the secondary formation of aerosols from sources located over a wide geographic area. Particulates, gases, aerosols, organic matter, elemental carbon, sea salt, and water vapor all contribute to visibility degradation. Some components scatter light and others absorb light. The primary cause of regional haze varies by region of the country. Ammonium sulfate is the primary contributor to visibility degradation in the eastern part of the country; ammonium nitrate in central California, southern California, and the midwestern United States; organic carbon in the southeast United States, Sierra Nevada region of California, and northern Rockies of Montana; and coarse particles in the southwest United States (where the Project is located) and southern California (U. S. Forest Service et al. 2010). Natural degradation of visibility occurs with light scattering of air molecules, naturally occurring aerosols and dust particles, and water vapor.

For a specific facility, visibility impairment from certain emissions is compared against natural visibility conditions for an area to determine if unacceptable levels are indicated. This is done via calculations or computer models that assess the effects of the various emission and aerosol components in the plume on visibility of the area in question.

5.0 Methods

This report describes, compares, and contrasts the effects to the existing environment (summarized in Section 6.0) that could be caused by implementation of the proposed action, action alternatives, or no action alternative (summarized in Section 2.0). The analysis in this report addresses only those issues that were specifically identified during scoping (by federal, state, or local agencies; tribes; interested or affected parties; the public; or the BLM Interdisciplinary Team) or where an analysis is required by law, regulation, or agency direction. The issues addressed in this report (Table 1.6-1 in the EIS) include:

• Fugitive dust emissions (Project-specific, cumulative)

• Other emissions (including construction and operation equipment)

• Compliance with National Ambient Air Quality Standards (NAAQS)

• PSD increments

• Effects to Class I and Class II areas of interest

• Greenhouse gas (GHG) emissions

• Effects of GHG emission on climate change

As discussed in Section 2.0 of this report, the Project would generate SOP from the processing of potassium-bearing brines at a maximum production of approximately 372,000 tons (337,500 metric tons) per year, with an average production of 328,500 tons (298,000 metric tons) per year over the 35-year life of the project. The production level for the Project would be equivalent under Alternative 1, 2, 3, 4, or 5. The alternatives are focused on the initial construction phase of the Project and do not directly affect operations of the Project. As shown in Table 6, the initial construction phase would run from 2019 to 2021, the 50 percent operational phase with concurrent construction would run from 2022 to 2023, and the full-scale operational phase and subsequent construction would span the years 2024 to 2053. After

17 Sevier Playa Potash Project Resource Report: Air Quality and Climate

2053, mining may continue if resources remain; otherwise, decommissioning and reclamation would begin. ROW grants would be renewed if needed.

Both the construction and operation phases of the Project would affect air quality in the analysis area. BLM is required to assess and disclose to the public these effects as part of the NEPA process. CPM contracted Ramboll, Inc. (Ramboll) to perform the air quality analyses for the Project to meet this requirement. To accomplish this, Ramboll employed the standard and typically accepted procedure that involves two basic tasks. The first task involves generating an emissions inventory that estimates emissions over the life of the Project for each criteria pollutant. The second task involves incorporating these emissions into a computer-based air dispersion model that simulates the atmosphere and how and where the air pollutants travel. The model output consists of pollutant concentrations over various averaging periods at specified locations. These concentrations are then compared to the applicable standards. Ramboll’s effort is presented in the Final Air Dispersion Modeling Protocol for NEPA Analysis (Modeling Protocol) (Ramboll 2018a) and Final Air Dispersion Modeling Report for NEPA Analysis (Modeling Report) (Ramboll 2019a). The remainder of this document describes the information provided in these two documents.

Table 6 Project Phases and Time Frames

Project Phase Activity Summary Years Covered Construction and development of on-site mining infrastructure including road networks; production, preconcentration, and waste product storage ponds; canals; Processing Facility; infrastructure; Calendar Years: berms; trenches for the first set of BMUs; and initial trenches for Construction 2019 to 2021 the second set of BMUs. Construction and development of off-site Project Years: 1 to 3 infrastructure including the Rail Loadout Facility; Rail Spur; power and communication lines; and communication towers. Excavation of gravel pits.

Start-up, Production start-up at 50 percent of the total capacity. Ongoing Concurrent infrastructure construction and expansion including: canals, Calendar Years: Construction, extraction wells, waste storage, rail network, Rail Loadout 2022 to 2023 and 50 percent Facility, and the next set of BMUs. Excavation of gravel pits. Project Years: 4 to 5 Operation Production at full capacity. Construction of Natural Gas Pipeline Full-Scale (2025) and construction of the remaining set of BMUs and Calendar Years: Operations and extraction wells. Excavation of gravel pits. Maintenance and 2024 to 2053 Concurrent operation of infrastructure and facilities. Closure and/or Project Years: 6 to 35 Construction reactivation of BMUs, as applicable.

5.1 Differences between Draft Analysis and Final Analysis

Several modifications were made to the Project between the Draft and Final EIS. The changes involved refinements to the Mining Plan and the equipment that would be required to accomplish various tasks and processes. In addition, some source characterizations were altered due to modifications of the source itself or how controls would be applied. The Project modifications required updates to the emissions inventory and a revised air modeling analysis. Specifically, the changes include:

• Revisions to the construction schedule and equipment list.

18 Sevier Playa Potash Project Resource Report: Air Quality and Climate

• Updates to the engine tier level commitments.

• Removal of the bus commute scenario for worker travel. All worker commute trips are now assumed to be made in passenger vehicles.

• Additional areas of windblown dust emissions.

• Removal of the unpaved road emission factor reduction for precipitation since watering control is already accounted for in the emission estimates.

• Revision of the unpaved surface silt content from 8.4 percent for all unpaved surfaces to 8.4 percent for roadways built with natural soil and 6.4 percent for roadways covered with gravel.

• Updated material handling details, including control efficiencies, for operations at the Processing Facility and Rail Loadout Facility. Baghouse emissions were revised based on grain loading limits rather than uncontrolled emissions plus 95 percent control efficiency.

• Addition of emissions from gravel pit construction and operation.

5.2 Emissions Inventory

An emissions inventory is an accounting of emissions by pollutant from a facility. The focus is typically on the NAAQS pollutants of PM10, PM2.5, NO2, CO, and SO2 (see Section 6.2 for a general description of these pollutants). As a special note, emissions of nitrogen oxides (NOX) are considered collectively for the pollutant NO2 because NOX emissions convert relatively quickly in the atmosphere to NO2 (see Section 6.2.2 for a more detailed explanation). Volatile organic compounds (VOCs) are also estimated for an emissions inventory. While this pollutant has no direct ambient air quality standard, VOCs are involved in the creation of O3 (see Section 6.2.4 for more detailed explanation), which does have a NAAQS.

As discussed in Section 2.3, CPM provided Ramboll with a Mining Plan (CPM and Stantec 2019a), Gravel Pit Mining Plan (CPM and Stantec 2019b), and POD (CPM 2019a), collectively known in this Air Resources Report as the “Project Plan”. The Project Plan identified equipment fleet, production levels, activity levels, material movement, active area sizes on the playa, and other processes and stationary equipment that would be involved in the construction and/or operation of the Project as well as off-site support facilities and gravel pits. To generate a Project emissions inventory of PM10, PM2.5, NOX, CO, SO2, and VOCs based on the Project Plan, Ramboll proceeded through a standard multi-step process:

1. Identify the air pollution generating activities

2. Identify the air pollutants from those activities

3. Estimate the amount of air pollution emissions from those activities using the activity level (for example, hours/year, tons/hour, vehicle miles traveled [VMT]/year), published emission factors, and air pollution controls

This was done for all air pollutant emitting sources for every year the Project would be active (2019 to 2053) over the three distinct phases of the Project (Table 6). The majority of sources would be dynamic with the locations and activity levels changing over the life of the Project. As a result, the Project’s emissions would vary from year to year. This is typical for mining operations, where activity levels from sources can depend on location at the Project.

19 Sevier Playa Potash Project Resource Report: Air Quality and Climate

From the Project Plan and the emissions inventory, Project emission sources can be broken down into one of three categories: (1) stationary point-type sources, (2) fugitive sources, or (3) tailpipe sources. Stationary point-type sources are processes or activities that release emissions into the air from a stack, building vent, or other functionally equivalent device. Stationary point-type sources at the Project would include:

• Processing Facility crushers, screens, baghouses, and material handling points

• Rail Loadout Facility crushers, screens, baghouses, and material handling points

• Fuel storage tanks

• Process dryers located at the Processing Facility

• Pumps

• Generators

• Gravel pit crushers, screens, and material handling points.

Fugitive sources produce emissions that cannot reasonably be discharged through a stack or vent. Air pollutant releases from fugitive sources tend to be at or near ground level. Fugitive sources at the Project would include:

• Off-road, heavy-duty equipment used in construction activities working on the playa (for example, building roads, ponds, canals, etc.)

• Off-road, heavy-duty equipment used in operational activities working on the playa (for example, managing the BMUs, canals, ponds, roads, etc.) and gravel pits

• Windblown dust from areas disturbed by construction and operational activities

• Operation-related heavy-duty haul trucks, worker vehicles, propane deliveries, and off-road, heavy-duty equipment traveling on unpaved roads

• Construction-related vendor trucks, worker vehicles, propane deliveries, and off-road, heavy-duty equipment traveling on unpaved roads

• Operation- and construction-related traffic on paved roads

Tailpipe sources are exhaust emissions from mobile heavy-duty equipment and light-duty vehicles, with air pollutant releases near ground level. Tailpipe sources associated with the Project would include:

• Off-road, heavy-duty equipment

• On-road vehicles (on-playa vehicles and off-playa worker traffic, propane deliveries, construction vendors, construction hauling trips, and commercial trucks)

• Rail locomotive exhaust (short and long line haul)

• Rail switching exhaust.

20 Sevier Playa Potash Project Resource Report: Air Quality and Climate

The methodologies used to estimate emissions from stationary, fugitive, and tailpipe sources for the Project are discussed below, along with summaries of emissions for all applicable pollutants. The maximum Project PM10 and PM2.5 emissions occur in calendar year (CYr) 2025 (Project Year (PYr 7)), which is a full-capacity operational year with concurrent construction. The maximum Project emissions of NOX, CO, VOC, and SO2 occur in CYr 2020 (PYr 2), which is the middle construction year with no operational activities at the Project.

5.2.1 Emissions from Stationary Sources

Emissions from stationary sources were estimated using annual and maximum daily activity levels for each source combined with published emission factors and air pollution controls. The published emission factors are included in EPA’s Fifth Edition Compilation of Air Pollutant Emission Factors (AP-42) and the Mojave Desert Air Quality Management District (MDAQMD) document Emissions Inventory Guidance Mineral Handling and Processing Industries (MDAQMD 1999). EPA’s Tier 4 emission standards for diesel engines were also used.

Material transfer emissions were calculated with AP-42 Section 13.2.4 Aggregate Handling and Storage Piles (EPA 2006a), with parameters for moisture and wind speed based on CPM data (see Section 5.3.4 and Section 6.4 for a description of the meteorological data). Screening and crushing emissions were estimated with MDAQMD factors. All screening and crushing emissions, and the majority of the transfer point emissions, would be controlled with baghouses. The emissions from the process dryers were calculated with factors from AP-42 Section 1.5 Liquefied Petroleum Gas Combustion (EPA 2008). Gravel pit emissions were calculated employing factors from AP-42 11.19.2 Crushed Stone Processing and Pulverized Material Processing (EPA 2004a) and AP-42 Section 13.2.4 Aggregate Handling and Storage Piles (EPA 2006a). Pump and generator emission factors were based EPA’s Federal Tier 4 standards.

The controlled annual emissions for the stationary sources are collectively summarized in Table 7 for the maximum CYr and corresponding PYr for each respective pollutant, while Table 8 lists the controlled maximum daily emissions. Note that for regulatory purposes, the stationary source totals listed in Table 7 are what would be compared against major source thresholds (250 tons/year for PSD and 100 tons/year for Title V), demonstrating that the Project would be a minor source (Section 4.2 and Section 4.4).

Table 7 Stationary Source Maximum Annual Emissions Summary

Controlled Maximum Annual Tons

PM10 PM2.5 NOX CO VOC SO2 CYr 2025 CYr 2025 CYr 2020 CYr 2020 CYr 2020 CYr 2020 Point Source Category PYr 7 PYr 7 PYr 2 PYr 2 PYr 2 PYr 2 Construction Stationary Sources NA2 NA2 5.4 34.0 1.9 <0.1 (Fuel Combustion) Processing Facility Operations 44.3 26.4 NA2 NA2 NA2 NA2 (Material Handling) Rail Loadout Operations 12.4 11.5 NA2 NA2 NA2 NA2 (Material Handling) Operational Stationary Sources <0.1 <0.1 NA2 NA2 NA2 NA2 (Fuel Combustion) Gravel Pits (Material Handling) <0.1 <0.1 0 0 0 0 Rail Loadout Operations (Fuel 0.2 0.1 NA2 NA2 NA2 NA2 Combustion)

21 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 7 Stationary Source Maximum Annual Emissions Summary

Controlled Maximum Annual Tons

PM10 PM2.5 NOX CO VOC SO2 CYr 2025 CYr 2025 CYr 2020 CYr 2020 CYr 2020 CYr 2020 Point Source Category PYr 7 PYr 7 PYr 2 PYr 2 PYr 2 PYr 2 Supporting Equipment 0 0 0 0 <0.1 0 Stationary Source Total1 56.9 38.1 5.4 34 2.0 <0.1 1 Totals may not appear exact because of rounding. 2 This source is not operating during the respective calendar year / project year.

Table 8 Stationary Source Maximum Daily Emissions Summary

Controlled Maximum Daily Pounds

PM10 PM2.5 NOX CO VOC SO2 CYr 2025 CYr 2025 CYr 2020 CYr 2020 CYr 2020 CYr 2020 Point Source Category PYr 7 PYr 7 PYr 2 PYr 2 PYr 2 PYr 2 Construction Stationary Sources NA2 NA2 41.0 275.0 15.0 0.4 Processing Facility Operations 798.0 229.0 NA2 NA2 NA2 NA2 (Material Handling) Rail Loadout Operations 93.0 67.0 NA2 NA2 NA2 NA2 (Material Handling) Operational Stationary Sources 0.4 0.4 NA2 NA2 NA2 NA2 Gravel Pits (Material Handling) 0.3 <0.1 0 0 0 0 Rail Loadout Operations (Fuel 0.8 0.8 NA2 NA2 NA2 NA2 Combustion) Supporting Equipment 0 0 0 0 0.3 0 Stationary Source Total1 893.2 297.0 41.0 275.0 15.3 0.4 1 Totals may not appear exact because of rounding. 2 This source is not operating during the respective calendar year / project year.

5.2.2 Emissions from Fugitive Sources

Fugitive dust emissions (PM in the form of small dirt particles liberated from the ground surface due to various activities) were calculated using annual operation and maximum daily activity levels for each source combined with published emission factors and air pollution controls. Some emission factors contain specific parameters such as material silt content (defined as the percentage of material <200 mesh), and material moisture content. These parameters were based on a mixture of default values and Project-specific values, depending on the source and emission factor.

Fugitive dust emissions from bulldozing, scraping, and grading activities were calculated with MDAQMD emission factors, using a silt content of 30 percent and a moisture content of 23 percent. The silt content was based on a default value from MDAQMD (1999) and the moisture content from soil sampling at the Sevier Playa performed by Ramboll (2019b). Emission control efficiencies of 80 percent were assumed for the application of water and brine for on-playa activities and 70 percent control with watering only for off-playa activities, based on UDAQ (2015) control efficiency guidance.

22 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Wind-blown dust emissions were calculated for recently disturbed areas employing the emission factors in AP-42 Section 13.2.5 Industrial Wind Erosion (EPA 2006b) and MDAQMD (1999). All disturbed area assumptions were based on restrictions outlined in the Fugitive Dust Control Plan (FDCP) (CPM 2019f). Fugitive dust control efficiencies were based on the application of water (70 percent control) or a combination of water and brine (80 percent control), consistent with UDAQ (2015) guidance.

Unpaved roads would be constructed using roadbed material from soils imported from various locations. To estimate emission from travel along unpaved roads, an equation from AP-42 Section 13.2.2 Unpaved Roads (EPA 2006c) was employed, along with a default silt content of 8.4 percent from AP-42 Table 13.2.2-1. This silt content value is well above the UDAQ default value of 4.8 percent used in permitting. Chemical suppressant and water would be applied to Project unpaved haul roads, resulting in a control of 85 percent based on UDAQ (2015) control efficiency guidance.

Paved road emissions were calculated with an equation from AP-42 Section 13.2.1 Paved Roads (EPA 2011a). The silt loading was based on MDAQMD (1999) default parameters. No controls are assumed, as the paved roads are all public roadways and not managed by CPM.

Gravel pit emissions were calculated by employing AP-42 11.19.2 Crushed Stone Processing and Pulverized Material Processing (EPA 2004a) and AP-42 Section 13.2.4 Aggregate Handling and Storage Piles (EPA 2006a).

The controlled annual emissions for the fugitive dust sources are collectively summarized in Table 9 for the maximum CYr and PYr while Table 10 lists the controlled maximum daily emissions for these same years. Note that for regulatory purposes for the Project, fugitive dust emissions are not counted towards major source thresholds (250 tons/year for PSD and 100 tons/year for Title V), and thus the Project would be considered a minor source, even though PM10 emissions from fugitive dust are 528 tons/year (Section 4.2 and Section 4.4).

Note that the fugitive dust emission calculations focus on processes that generate PM10 and PM2.5 from the activities themselves (for example, bulldozing the ground surface or pile, dumping from a truck to a pile, vehicles creating dust as they travel on unpaved roads, etc.), and not the air pollutants emitted from the tailpipes due to fuel combustion. Tailpipe emissions from the equipment are addressed separately in Section 5.2.3.

Table 9 Fugitive Dust Source Maximum Annual Emissions Summary

Controlled Maximum Annual Tons

Fugitive Dust Source Category PM10, CYr 2025, PYr 7 PM2.5, CYr 2025, PYr 7 Construction Off-road Equipment 29.9 9.1 Construction Windblown Dust from Disturbed Areas 5.2 2.1 Construction On-Road Travel 160.5 16.0 Operational Off-Road Equipment 15.8 4.8 Operational Windblown Dust from Disturbed Areas 6.4 2.5 Operational On-Road Travel 307.7 31.6 Gravel Pits (Operational Off-road Equipment 2.8 0.9 Fugitive Dust Total1 528.3 67.2 1 Totals may not appear exact because of rounding.

23 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 10 Fugitive Dust Source Maximum Daily Emissions Summary

Controlled Maximum Daily Pounds

Fugitive Dust Source Category PM10, CYr 2025, PYr 7 PM2.5, CYr 2025, PYr 7 Construction Off-road Equipment 182.3 55.7 Construction Windblown Dust from Disturbed Areas 211.3 84.5 Construction On-Road Travel 978.5 97.8 Operational Off-Road Equipment 96.4 29.3 Operational Windblown Dust from Disturbed Areas 257.1 102.9 Operational On-Road Travel 2,011.2 206.6 Gravel Pits Operational Off-road Equipment 17.2 5.4 Fugitive Dust Total1 3,754.0 582.3 1 Totals may not appear exact because of rounding.

5.2.3 Emissions from Tailpipe Exhaust

Tailpipe exhaust emissions due to fuel combustion (PM10, PM2.5, NOX, CO, VOCs, and SO2) were calculated using annual operation and maximum daily activity levels for each source combined with published emission factors or emissions software. The emissions from off-road equipment used the applicable EPA engine tier level for which CPM would commit, specifically Tier 4, Tier 4 final, Tier 3, or Tier 2. The majority of the heavy-duty equipment would operate with Tier 4 or Tier 4 final engines, while the remainder would operate with Tier 3 engines. Personnel transports would operate with Tier 2 engines. Emissions from on-road vehicles were based on emission factors from EPA’s Motor Vehicle Emissions Simulator (MOVES) emission model (version 2014a), following the MOVES2014 and MOVES2014a Technical Guidance (EPA 2015). MOVES2014a was run at the Project level in order to obtain speed- specific, gram-per-mile emission factors for various categories of vehicles (worker commute vehicles, commercial trucks, construction haul trucks, and personnel transports.). Winter and summer emission factors appropriate for 2019 and 2022 were employed to calculate annual emissions for all the years 2019 to 2053. Default meteorological parameters for Millard County, Utah were used along with default fuel data.

Exhaust emissions associated with the Rail Loadout Facility were calculated for railcar switching operations, short line haul in the near vicinity of the Project, and long line haul. Emissions were calculated using EPA emission factors assuming a 2014 locomotive engine (EPA 2009), and locomotive and train parameters consistent with CPM data and other information (such as locomotive fuel consumption and time required for switching).

The annual emissions for the tailpipe exhaust sources are collectively summarized in Table 11 for the maximum CYr and PYr for each respective pollutant, while Table 12 lists the maximum daily emissions. Note that for regulatory purposes, tailpipe emissions are considered to be fugitives and are not counted towards major source thresholds (250 tons/year for PSD and 100 tons/year for Title V). Thus, the Project would be a minor source (Section 4.2 and Section 4.4), even though NOX and CO emissions are 151.6 and 315.0 tons/year, respectively.

24 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 11 Tailpipe Source Maximum Annual Emissions Summary

Maximum Annual Tons

PM10 PM2.5 NOX CO VOC SO2 Tailpipe Exhaust Source CYr 2025 CYr 2025 CYr 2020 CYr 2020 CYr 2020 CYr 2020 Category PYr 7 PYr 7 PYr 2 PYr 2 PYr 2 PYr 2 Construction On-Road Travel <0.1 <0.1 4.3 37.5 1.2 <0.1 Construction Off-road 1.1 1.0 125.3 257.2 14.4 0.3 Equipment Operational On-Road Travel 0.5 0.2 NA2 NA2 NA2 NA2 Operational Off-Road Equipment 0.8 0.8 NA2 NA2 NA2 NA2 Gravel Pits (Construction Off- NA2 NA2 21.9 20.2 1.2 <0.1 road Equipment) Gravel Pits (Operational Off- <0.1 <0.1 NA2 NA2 NA2 NA2 road Equipment) Tailpipe Total1 2.4 2.0 151.6 315.0 16.8 0.3 1 Totals may not appear exact because of rounding. 2 This source is not operating during the respective calendar year / project year.

Table 12 Tailpipe Source Maximum Daily Emissions Summary

Maximum Daily Pounds

PM10 PM2.5 NOX CO VOC SO2 Tailpipe Exhaust Source CYr 2025 CYr CYr 2020 CYr 2020 CYr 2020 CYr 2020 Category PYr 7 2025PYr 7 PYr 2 PYr 2 PYr 2 PYr 2 Construction On-Road Travel 0.3 0.1 27.7 233.4 7.3 0.2 Construction Off-road 6.4 6.2 794.4 1,604.9 89.3 1.8 Equipment Operational On-Road Travel 3.0 1.2 NA2 NA2 NA2 NA2 Operational Off-Road Equipment 5.2 5.0 NA2 NA2 NA2 NA2 Gravel Pits – Construction Off- NA2 NA2 133.8 123.2 7.5 0.1 road Equipment Gravel Pits - Operational Off- 0.2 0.2 NA2 NA2 NA2 NA2 road Equipment Tailpipe Total1 15.1 12.6 955.9 1,961.5 104.1 2.1 1 Totals may not appear exact because of rounding. 2 This source is not operating during the respective calendar year / project year.

5.2.4 Project Emissions Summary

Table 13 catalogs the estimated annual emissions for the Project collectively by stationary, fugitive and tailpipe source categories for the maximum CYr and PYr for each respective pollutant, while Table 14 lists the maximum daily emissions for these same source groups. The air pollutant with the highest emissions is PM10, followed by CO and NOX. Fugitive sources as a category emit the highest percentage of PM10, which is typical of a mining facility. Tailpipe sources as a category emit the highest percentage of gaseous pollutants, which is also typical of a mining facility. As stated above, even though the total

25 Sevier Playa Potash Project Resource Report: Air Quality and Climate

emissions from stationary, fugitive, and tailpipe sources are over 250 tpy for PM10 and CO and over 100 tpy for NOX, the only emissions that would count towards major source thresholds for the Project for the purposes of PSD and Title V are the stationary source totals. The stationary source totals are under both of these limits, and thus the Project would be a minor source.

Table 13 Project Maximum Annual Emissions Summary

Maximum Annual Tons

PM10 PM2.5 NOX CO VOC SO2 CYr 2025 CYr 2025 CYr 2020 CYr 2020 CYr 2020 CYr 2020 Source Category PYr 7 PYr 7 PYr 2 PYr 2 PYr 2 PYr 2 Stationary Source Total 56.9 38.1 5.4 34.0 2.0 <0.1 Fugitive Dust Total 528.3 67.2 0.0 0.0 0.0 0.0 Tailpipe Total 2.4 2.0 151.6 315.0 16.8 0.3 Project Total 587.6 107.2 157.0 349.0 18.7 0.4 1 Totals may not appear exact because of rounding.

Table 14 Project Maximum Daily Emissions Summary

Maximum Daily Pounds

PM10 PM2.5 NOX CO VOC SO2 CYr 2025 CYr 2025 CYr 2020 CYr 2020 CYr 2020 CYr 2020 Source Category PYr 7 PYr 7 PYr 2 PYr 2 PYr 2 PYr 2 Stationary Source Total 893.2 297.0 41.0 275.0 15.3 0.4 Fugitive Dust Total 3,754.0 582.3 0.0 0.0 0.0 0.0 Tailpipe Total 15.1 12.6 955.9 1,961.5 104.1 2.1 Project Total 4,662.3 891.9 996.9 2,236.5 119.5 2.5 1 Totals may not appear exact because of rounding.

Note that the source category emission totals listed in Tables 13 and 14 reflect the maximum Project total by pollutant for the respective year: 2020 for gaseous pollutants and 2025 for PM10 and PM2.5. An individual source category may have higher emissions by pollutant in a different year than those listed in Tables 13 and 14; however, the Project’s total emissions (from all source categories) would be lower in that year. This is especially true for gaseous pollutants from the stationary source category because, for the year 2020, the Project would still be under construction and would have not operational sources. During the operational phase (post-2023), the stationary source category total for the gaseous pollutants would be roughly double what is shown for the year 2020, but total emissions would be lower because there would be reduced emissions from construction equipment. These stationary source totals would remain under the PSD limit of 250 tpy and Title V limit of 100 tpy for all construction and production years.

Table 15 lists total annual emission in tons per year for all six pollutants across the entire life of the Project, with the three phases identified, while Table 16 catalogs total maximum daily emissions. The annual and maximum daily emissions vary from year to year across the life of the Project. Again, this is typical for a mining operation and is driven by the different operation levels and locations of the activities.

26 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 15 Project Annual Emissions

Calendar Project Tons per Year Project Phase Year Year PM10 PM2.5 NOX CO VOC SO2 2019 1 450.7 63.4 134.2 297.8 15.7 0.3 Construction 2020 2 514.6 74.5 157.0 349.1 18.7 0.4 2021 3 460.8 64.8 121.2 280.2 14.8 0.3 50% Operation and 2022 4 446.6 71.8 112.0 261.1 14.2 0.3 Construction 2023 5 430.9 72.1 82.9 183.3 10.2 0.2 2024 6 486.8 91.4 94.0 165.6 9.9 0.2 2025 7 587.6 107.2 105.5 218.2 12.8 0.3 2026 8 486.8 91.4 94.0 165.6 9.9 0.2 2027 9 486.8 91.4 94.0 165.6 9.9 0.2 2028 10 486.8 91.4 94.0 165.6 9.9 0.2 2029 11 486.8 91.4 94.0 165.6 9.9 0.2 2030 12 390.9 78.9 67.0 112.0 6.9 0.2 2031 13 390.9 78.9 67.0 112.0 6.9 0.2 2032 14 390.9 78.9 67.0 112.0 6.9 0.2 2033 15 486.8 91.4 94.0 165.6 9.9 0.2 2034 16 486.8 91.4 94.0 165.6 9.9 0.2 2035 17 486.8 91.4 94.0 165.6 9.9 0.2 2036 18 390.9 78.9 67.0 112.0 6.9 0.2 2037 19 390.9 78.9 67.0 112.0 6.9 0.2 100% Operation and 2038 20 390.9 78.9 67.0 112.0 6.9 0.2 Construction 2039 21 486.8 91.4 94.0 165.6 9.9 0.2 2040 22 486.8 91.4 94.0 165.6 9.9 0.2 2041 23 486.8 91.4 94.0 165.6 9.9 0.2 2042 24 486.8 91.4 94.0 165.6 9.9 0.2 2043 25 486.8 91.4 94.0 165.6 9.9 0.2 2044 26 390.9 78.9 67.0 112.0 6.9 0.2 2045 27 390.9 78.9 67.0 112.0 6.9 0.2 2046 28 390.9 78.9 67.0 112.0 6.9 0.2 2047 29 390.9 78.9 67.0 112.0 6.9 0.2 2048 30 390.9 78.9 67.0 112.0 6.9 0.2 2049 31 390.9 78.9 67.0 112.0 6.9 0.2 2050 32 390.9 78.9 67.0 112.0 6.9 0.2 2051 33 390.9 78.9 67.0 112.0 6.9 0.2 2052 34 390.9 78.9 67.0 112.0 6.9 0.2 2053 35 390.9 78.9 67.0 112.0 6.9 0.2 Maximum 587.6 107.2 157.0 349.1 18.7 0.4 Minimum 390.9 63.4 67.0 112.0 6.9 0.2 Average 442.1 83.0 85.9 158.1 9.3 0.2

27 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 16 Project Maximum Daily Emissions by Year

Calendar Project Pounds per Day Project Phase Year Year PM10 PM2.5 NOX CO VOC SO2 2019 1 3,165.8 529.3 858.0 1923.3 101.7 2.1 Construction 2020 2 3,625.2 624.0 997.2 2236.5 119.9 2.5 2021 3 3,297.0 565.1 778.9 1816.2 96.0 2.0 50% Operation and 2022 4 3,302.0 588.3 703.1 1739.1 94.4 2.2 Construction 2023 5 3,196.5 580.8 524.0 1264.5 70.3 1.6 2024 6 3,868.3 723.6 591.7 1114.0 66.0 1.5 2025 7 4,662.3 891.9 662.0 1434.8 83.6 1.8 2026 8 3,868.3 723.6 591.7 1114.0 66.0 1.5 2027 9 3,868.3 723.6 591.7 1114.0 66.0 1.5 2028 10 3,868.3 723.6 591.7 1114.0 66.0 1.5 2029 11 3,868.3 723.6 591.7 1114.0 66.0 1.5 2030 12 3,283.5 647.6 427.1 786.9 47.6 1.1 2031 13 3,283.5 647.6 427.1 786.9 47.6 1.1 2032 14 3,283.5 647.6 427.1 786.9 47.6 1.1 2033 15 3,868.3 723.6 591.7 1114.0 66.0 1.5 2034 16 3,868.3 723.6 591.7 1114.0 66.0 1.5 2035 17 3,868.3 723.6 591.7 1114.0 66.0 1.5 2036 18 3,283.5 647.6 427.1 786.9 47.6 1.1 2037 19 3,283.5 647.6 427.1 786.9 47.6 1.1 100% Operation and 2038 20 3,283.5 647.6 427.1 786.9 47.6 1.1 Construction 2039 21 3,868.3 723.6 591.7 1114.0 66.0 1.5 2040 22 3,868.3 723.6 591.7 1114.0 66.0 1.5 2041 23 3,868.3 723.6 591.7 1114.0 66.0 1.5 2042 24 3,868.3 723.6 591.7 1114.0 66.0 1.5 2043 25 3,868.3 723.6 591.7 1114.0 66.0 1.5 2044 26 3,283.5 647.6 427.1 786.9 47.6 1.1 2045 27 3,283.5 647.6 427.1 786.9 47.6 1.1 2046 28 3,283.5 647.6 427.1 786.9 47.6 1.1 2047 29 3,283.5 647.6 427.1 786.9 47.6 1.1 2048 30 3,283.5 647.6 427.1 786.9 47.6 1.1 2049 31 3,283.5 647.6 427.1 786.9 47.6 1.1 2050 32 3,283.5 647.6 427.1 786.9 47.6 1.1 2051 33 3,283.5 647.6 427.1 786.9 47.6 1.1 2052 34 3,283.5 647.6 427.1 786.9 47.6 1.1 2053 35 3,283.5 647.6 427.1 786.9 47.6 1.1 Maximum 4,662.3 891.9 997.2 2236.5 119.9 2.5 Minimum 3,165.8 529.3 427.1 786.9 47.6 1.1 Average 3,544.9 672.8 544.2 1071.1 62.4 1.4

28 Sevier Playa Potash Project Resource Report: Air Quality and Climate

5.2.5 Emission Inventory Limitations

The air pollutant emission calculations for a source are based on emission factors and activity levels. The emission factors themselves were developed based on testing and monitoring of air pollutants from sources in relation to a specific activity. Emission factors have varying levels of confidence, depending on how they were developed, the amount of available data, how much the data varied, how applicable the factor is to other locations, the similarity of sources, as well as other variables. The AP-42 factors are listed with a rating from A to F, with A indicating the highest level of confidence and F representing the lowest level of confidence. The MDAQMD emission factors rely in part on AP-42, as well as other resources and derivations. The silt and moisture parameters used in the AP-42 and MDAQMD factors can be default or actual measured values. The emission software model MOVES2014a contains mathematical algorithms that the software uses to estimate emissions. These algorithms are based on general profiles and other built-in databases, along with user inputs for the specific fleet inventory. Thus, all of the emission factors are generic and represent only an approximation for the actual Project sources.

The equipment inventory, activity levels, production levels, and other Project Plan data were projected by CPM at the time the analysis was completed. If these projections change, the emissions would also change in relation to the activity level and emission factor. While modifications to the Project Plan data are not anticipated, any changes would be addressed in the UDAQ permitting process.

As a result of applying general emission factors to projected Project Plan data, the air pollution emission inventory for the Project represents an estimate only. However, this procedure is a standard methodology accepted by agencies to generate an emissions inventory for both existing sources and for sources yet to be constructed.

5.3 Dispersion Modeling Methods and Setup

Ramboll conducted dispersion modeling for the Project using the American Meteorological Society (AMS)/EPA Regulatory Model (AERMOD). GAQM lists AERMOD as the preferred model to assess source impacts in the near-field, i.e., within 50 km (31 miles) of the source. AERMOD includes preprocessors, which are separate programs that manage and prepare data for direct input into the model. The two main preprocessors are AERMET, which handles meteorological data, and AERMAP, which handles terrain data. AERMOD Version 18081, which is the current version as of the writing of this document, was employed for the Project analysis.

5.3.1 Project Years to Model

As shown in Table 15 and Table 16, the emissions from the Project would vary from year to year. To assess the effects from the Project conservatively, the modeling analysis focused on the worst-case years. To isolate which years represented the worst-case, Ramboll performed an initial screening to determine which had the greater effect: (1) the maximum emission year, or (2) a year with lower emissions but with relatively high density of sources closer to the boundary. From that screening, it was determined that the maximum emissions year had a greater effect on air quality. As a result, the following maximum- emission calendar years were modeled by pollutant and averaging time:

• PM10 24-hour and annual: Year 2025

• PM2.5 24-hour and annual: Year 2025

• NO2 1-hour and annual: Year 2020

29 Sevier Playa Potash Project Resource Report: Air Quality and Climate

• CO 1-hour and 8-hour: Year 2020

• SO2 1-hour, 3-hour, 24-hour and annual: Year 2020

5.3.2 Model Input: Project Sources and Emissions

Project emission sources for the maximum years listed above were characterized and entered as input into AERMOD. Sources were identified by type: point, line, volume, or area. A point source is a source with a stack; a line source is a long, thin source like a road, trench or canal; a volume source can be a building vent, open process area, or a road (if used in a spaced series along the road); and an area source can be an open pile of material, a disturbed and non-vegetated plot of land, or a road (if used in a connected series along the road).

Table 17 provides a list of the various sources that occur during the worst-case years and how Ramboll categorized them in the model. Note that the model year for the gaseous pollutants of NOX, CO, and SO2 is a construction-only year without operational activities, while PM10 and PM2.5 were modeled during a 100% production year.

Table 17 Modeled Source Summary Description

Project Category and Calendar Year Model Type Emission Sources Construction Point Generator and pump exhaust 2020 Tailpipe emissions from heavy-duty equipment involved in the construction Construction Area, volume, of infrastructure and facilities; canals; berms; BMUs; preconcentration ponds; 2020 and line communication towers; Natural Gas Pipeline; access roads; and from travel on roads on- and off-playa. Process building stacks; process dryers; baghouses for material handling, Operations Point conveying, crushing, and screening activities; emergency generator and fire 2025 pump exhaust. Operations Process building vent emissions (those emissions not captured by the Volume 2025 baghouses); Rail Loadout Facility fugitives Operations Series of volume Dust from heavy duty equipment travel on unpaved roads, on the playa and 2025 sources off the playa; tailpipe emissions from heavy duty vehicles Dust from heavy duty equipment travel on very long unpaved roads; tailpipe Operations Series of line emissions from heavy duty vehicles; windblown dust from canals and 2025 sources trenches Operations Windblown dust from open areas, ponds, piles, and gravel pits; dust and Area 2025 tailpipe emissions from pond, pile management, and gravel pits

The Project source emissions calculated in Section 5.2 were apportioned and assigned in the model to the locations where they would occur (for example, along the entire road, open area on the playa, canals, BMU, Rail Loadout Facility, Processing Facility, etc.). The emissions were then distributed as appropriate per the activity, activity level, and source dimensions. For example, emissions from unpaved road traffic, which include fugitive dust from vehicle movement and tailpipe emissions, were distributed along the entire length of the road of concern, with the density of the emissions dictated by activity level along each road section.

30 Sevier Playa Potash Project Resource Report: Air Quality and Climate

The source apportionment was handled differently for short-term modeling, i.e., 24-hour averaging periods or less, as compared to long-term modeling, i.e., annual averages. This is due to the nature of the Project, which has limited amount of equipment, personnel, and areas that can be worked during an operational day as compared to an entire year. For the entire year, the equipment and personnel are distributed over all the year’s active areas.

For short-term modeling, EPA and BLM provided guidance to Ramboll on the selection of reasonable assumptions regarding the quantity of equipment and activities operating for a short duration (a few hours) on specific areas of the Project. The areas selected for modeling were based on the screening analysis cited above and provided maximum impact due to the proximity to the ambient air boundary. This methodology provides a reasonably conservative analysis of the effects of the project on the ambient environment in the short-term. For the long-term modeling, the equipment and activities were apportioned across all locations at which they occur during the year.

Three gravel pits have been proposed to support the Project. However, operational plans for these pits were unknown at the time this analysis was performed. For short-term modeling, only the two pits located near the Processing Facility were assumed to be operating at the same time. For the long-term, emissions from all three gravel pits were included.

Each model source was characterized by type, location, physical parameters, and short- and long-term emission rates of applicable pollutants. The locations were set in Universal Transverse Mercator (UTM), Zone 12 coordinates, and the preprocessor AERMAP (Version 18081) was utilized along with National Elevation Database (NED) electronic terrain maps to obtain above mean sea level (amsl) source elevations, following the User’s Guide for the AERMOD Terrain Preprocessor (AERMAP) (AERMAP User’s Guide) (EPA 2018b). The source parameters depend on the type of source modeled. Point source parameters include stack height, stack diameter, stack exit temperature, and stack exit velocity. Volume source characteristics include release height and the width and vertical depth of the source. Line source parameters include release height, line width, and vertical source depth. Area source characteristics include release height, length, width, orientation, and the depth of the source. Emission rates for the point and volume sources are expressed as mass per unit time (for example, grams per second (g/s)), while the emission rates for line and area sources are calculated as mass per unit time per unit area (for example, grams per second per square meter (g/s/m2)).

Ramboll used Project data from CPM as well as EPA guidance, the AERMOD Users Guide (EPA 2018a), and the Haul Road Work Group Memorandum (EPA 2012) when selecting the source parameters. Examples of the 24-hour PM10 model input parameters are listed in Table 18 for point sources, Table 19 for volume sources, Table 20 for line sources, and Table 21 for area sources. Note that data are entered into AERMOD in metric units, but are shown in these four tables in both metric and English units for clarity as applicable for most parameters.

Table 18 Example of Model Input for Point Sources

UTM Location Zone 12 PM10 Amsl Exit Stack Model Source Emission Rate Northing Elev. Stack Height Temp. Exit Velocity Diam. ID (g/s) / (lb/hr) Easting (m) (m) (m) (m) / (ft) (K) / (ºF) (m/s) / (ft/s) (m) / (ft) COMPACBH 0.324/2.571 308812.3 4288135.6 1390.1 30.2/99.0 Ambient 12.5/41.1 1.2/3.9 MAINDRBH 0.216/1.714 308791.2 4288172.0 1389.3 30.2/99.0 400/260 12.0/39.4 1.0/3.3 GLAZDRBH 0.103/0.814 308791.2 4288172.0 1389.3 30.2/99.0 350/170 11.4/37.5 1.0/3.3 RUNLBH 0.243/1.929 325140.0 4287279.0 1481.8 30.4/99.9 Ambient 18.2/59.7 1.2/4.0

31 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 19 Example of Model Input for Volume Sources

UTM Location Zone 12 PM10 Release Sigma Y Sigma Z Model Emission Rate Easting Northing Amsl Height Initial Width Initial Depth Source ID (g/s) / (lb/hr) (m) (m) Elev. (m) (m) / (ft) (m) / (ft) (m) / (ft) TRD_0383 0.0000041/0.000033 308619.9 4288349.2 1385.4 2.6/8.4 5.6/18.3 2.4/7.8 TRD_0384 0.0000041/0.000033 308619.9 4288337.2 1386.0 2.6/8.4 5.6/18.3 2.4/7.8 PRD_0001 0.0000028/0.000022 307572.3 4290069.9 1380.0 2.6/8.4 5.6/18.3 2.4/7.8 PRD_0002 0.0000028/0.000022 307568.3 4290058.6 1380.0 2.6/8.4 5.6/18.3 2.4/7.8

Table 20 Example of Model Input for Line Sources

1st UTM Location 2nd UTM Location Zone 12 Zone 12 Sigma Z PM10 Amsl Release Line Initial Model Emission Rate Easting Northing Easting Northing Elev. Height Width Depth Source ID (g/s/m2) (m) (m) (m) (m) (m) (m) / (ft) (m) / (ft) (m) / (ft) B13C1214 0.0000001257 314766.0 4293451.0 314849.8 4293450.5 1379.7 3.6/11.7 10.7/35.0 3.3/10.9 B13C1215 0.0000001257 313692.5 4291380.0 313953.4 4291378.7 1379.7 3.6/11.7 10.7/35.0 3.3/10.9 PRMRD001 0.0000000020 326687.6 4328601.1 326726.4 4328196.8 1380.0 2.0/6.4 12.0/39.4 1.8/6.0 PRMRD002 0.0000000020 326726.4 4328196.8 326894.9 4327857.1 1380.0 2.0/6.4 12.0/39.4 1.82/6.0

Table 21 Example of Model Input for Area Sources

PM10 UTM Location Zone 12 Amsl Release Model Source Emission Rate Elev. Height Number of Sigma Z Initial ID (g/s/m2) Easting (m) Northing (m) (m) (m) / (ft) Vertices Depth (m) / (ft) OPP_H4A 0.0000000120 312316.3 4293841.5 1379.7 2.6/8.4 8 2.4/7.8 OPP_MX2 0.0000000028 307328.5 4289281.8 1379.7 2.6/8.4 7 2.4/7.8 OTAILPS 0.0000000003 306032.4 4290560.2 1379.7 2.6/8.4 4 2.4/7.8 ON_RAIL 0.0000000154 324615.2 4287127.3 1482.0 9.5/31.3 13 2.2/7.3

Except for wind erosion, the sources were also characterized in the model with daily operating hours. Certain Project activities would function from 6 AM to 6 PM, others from 4 AM to 10 PM, while others would run for the full day (24 hours). This is addressed in the model by setting the respective source’s emissions to zero when the source is not operating.

Modeled PM10 and PM2.5 emissions from wind erosion sources varied for each hour of the year based on the wind speed for that hour from the meteorological data entered (Section 5.3.4), employing the methodology found in AP-42 Section 13.2.5 Industrial Wind Erosion (EPA 2006b). This technique ties PM emissions from windblown dust to wind speed in the model itself, with greater PM emissions at higher wind speeds and lesser PM emissions at lower wind speeds. When the wind speed for a specific

32 Sevier Playa Potash Project Resource Report: Air Quality and Climate hour is not fast enough to generate fugitive dust from the respective source, the modeled PM emission for that hour is zero.

In AERMOD, each pollutant is modeled in separate runs; however, multiple averaging periods for a pollutant can be included in the same run. For the Project, short-term and long-term emissions were modeled separately for each pollutant because the emission rates as well as the sources modeled were different between these two times frames (see the apportioning discussion above).

In addition, PM10 was modeled by using two separate emission source runs: (1) fugitive dust emission sources; and (2) tailpipe and stationary source emissions. This was done for both 24-hour and annual averaging periods for a total of four runs. The fugitive dust emissions sources were modeled separately because depletion parameters were included in the model for this source type; per EPA request depletion parameters were not used for tailpipe and stationary sources (Section 5.3.7). The results from the fugitive source and tailpipe/stationary source runs were summed after model run completion to obtain final Project results.

Table 22 lists the total number of point, volume, line, and area sources by pollutant and averaging period that were included in the model for the Project. Note there are a different number of volume and area sources between the short-term and long-term runs due to the different apportioning methods.

Table 22 Summary of Modeled Point, Volume, Line, and Area Sources

Number of Model Source Types Pollutant Averaging Period Model Year Point Volume Line Area

PM10 (fugitive) 24-hour 2025 0 6,120 372 26

PM10 (fugitive) Annual 2025 0 6,126 922 34

PM10 (stationary/tailpipe) 24-hour 2025 19 4,312 345 23

PM10 (stationary/tailpipe) Annual 2025 19 4,318 620 26

PM2.5 24-hour 2025 19 6,120 393 27

PM2.5 Annual 2025 19 6,126 943 35

NO2 1-hour 2020 19 3,466 286 6

NO2 Annual 2020 19 3,472 735 12 CO 1- and 8-hour 2020 19 3,466 286 6

SO2 1-, 3-, and 24-hour 2020 19 3,466 286 6

SO2 Annual 2020 19 3,472 735 12

5.3.3 Model Input: Building Downwash Parameters for Point Sources

Building downwash of plumes can occur for point sources located near or on buildings. To account for this, Ramboll employed EPA’s Building Profile Input Program for Plume Rise Model Enhancement (BPIPPRM (04274)), following the BPIP User’s Guide (EPA 2004c). The stack height and location for each point source were entered into BPIPPRM, along with building locations and sizes as would be constructed. BPIPPRM generated building downwash parameters for each point source and these were incorporated directly into the AERMOD input files. Note that volume, line, and area sources are not affected by building downwash in AERMOD.

33 Sevier Playa Potash Project Resource Report: Air Quality and Climate

5.3.4 Model Input: Meteorology

CPM collected surface meteorological data at the south end of the Sevier Playa from December 2011 to November 2012. See Section 6.4 for a data summary. These meteorological data underwent a quality assurance and quality control program following EPA’s PSD meteorological data collection guidelines. The data set was approved by UDAQ in December 2014. Because these data were collected by CPM near the playa, they are considered to be “on-site” and the GAQM allows one year to be used in the modeling analysis. The requirement for five years of meteorological data applies only if surface meteorological data are used from a different location than the project being modeled.

Ramboll processed the on-site surface meteorological data along with concurrent National Weather Service (NWS) upper air data from Elko, Nevada with the preprocessor AERMET (version 18081). Elko data were used instead of Salt Lake City because the surrounding terrain and climate at Elko are more similar to the analysis area. When processing the data, Ramboll followed EPA guidance and the User’s Guide for the AERMOD Meteorological Preprocessor (AERMET) (EPA 2018c). Ramboll processed the data with the Bulk Richardson scheme, which uses the solar radiation and delta temperature (the temperature difference between 2 and 10 meters (6.6 to 32.8 feet) above ground level) to calculate stability parameters. For temperature difference, a positive value (where temperature increases with height) indicates an inversion (stable conditions) and a negative value indicates unstable conditions.

AERMET also requires land surface parameters (surface roughness, albedo, and Bowen ratio) to process the meteorological data. Surface roughness is a measure of the density of obstacles. Albedo is reflectivity of the ground surface (for example, snow has very high reflectivity while barren dark soil has very low reflectivity). The Bowen ratio is a measure of surface moisture. These parameters are also involved in stability calculations. To obtain these surface parameters, Ramboll used the preprocessor AERSURFACE (version 13016) following the AERSURFACE User’s Guide (EPA 2013). AERSURFACE requires input of an electronic map of land cover data from the U.S. Geological Society (USGS) National Land Cover Data (NLCD) archives. In addition, the program requires input that defines each month as “wet” (highest 30th percentile), “average” (middle 40th percentile), or “dry” (lowest 30th percentile) for precipitation from a 30-year climate perspective. The program also requires information on whether or not the winter experiences continuous snow cover, defined as at least 1 inch for more than 50 percent of the time for each month.

Because precipitation and snow cover data are not available from CPM’s Sevier Playa meteorological station, the Black Rock meteorological station located about 15 km (9 miles) east was used as a proxy. Ramboll set each of the months of December 2011 to November 2012 to wet, average, or dry based on the Black Rock meteorological data collected from 1983 through 2012. Ramboll used Black Rock data as well to determine that snow cover is not continuous in the winter. AERSURFACE was run with default options and standard seasonal distributions: December, January, and February are winter; March, April, and May are spring; June, July, and August are summer; and September, October, and November are fall. The surface analysis was divided into 12 30-degree sectors, with the Sevier Playa meteorological station at the center. Output from AERSURFACE was directly incorporated into the AERMET input file.

5.3.5 Model Input: Receptors

Receptors are discrete locations in the analysis area where the model predicts air pollutant concentrations. Where the receptors are placed is relatively arbitrary, but the grid normally starts at the ambient air boundary and proceeds outward to the end of the nearfield analysis area. The grid spacing is denser close to the source and loosens at distances further from the source. Air quality inside the ambient air boundary is not evaluated for NAAQS, as the standards do not apply because the public would not have access to these areas.

34 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Ramboll established a Cartesian receptor grid in UTM coordinates (Zone 12) for the Project in relation to the ambient air boundary as listed in Table 23. The generic receptor grid consists of a series of nested grid sets with decreasing density centered on the Project’s ambient air boundary. The outside edge of the generic grid extends out to 30 km (18.6 miles) from the ambient air boundary, which equates to about 55 km (34 miles) from the center of the playa. Receptors were also placed along two parallel lines following Crystal Peak Road and Crystal Peak Spur Road, one line on either side of the roads, at a distance of 20 m (66 feet) from road centerline. Crystal Peak Road and Crystal Spur Peak Road run from the south end of the ambient air boundary to the Rail Loadout Facility about 15 km (9.3 miles) east. The receptor spacing along these two parallel lines varied between 25 m (82 ft) and 50 m (164 ft), depending on how close the parallel lines were to the ambient air boundary. Figure 2 depicts the complete modeling receptor grid of over 31,000 receptors. The receptors were processed with NED electronic terrain maps through the preprocessor AERMAP following the AERMAP User’s Guide (EPA 2018b) to obtain amsl elevation and “critical hill height”. Critical hill height describes the undulations of the terrain and drives how the plume flows when terrain is encountered. The plume may flow around, over, or into the terrain feature, or some combination of the three.

Table 23 Receptor Grid Spacing

Metric Units English Units Distance from Ambient Receptor Distance from Ambient Receptor Boundary (km) Spacing (m) Boundary (miles) Spacing (feet) Generic Modeling Grid 0 to 0.5 100(1) 0 to 0.3 328 0.5 to 2 200 0.3 to 1.2 656 2 to 5 500 1.2 to 3.1 1640 5 to 10 1000 3.1 to 6.2 3281 10 to 30 2000 6.2 to 18.6 6562 Parallel Line on Each Side of Crystal Peak Road and Crystal Peak Spur Road (2) 0 to 0.5 25 0 to 0.3 82 0.5 to 15 50 0.3 to 9.3 164 (1) Receptor spacing was set to 25 m (82 feet) for high emission areas along the property boundary to further refine effects. (2) The roads run from the south side of the ambient air boundary 15 km (9.3 miles) east to the Rail Loadout Facility.

5.3.6 Model Input: Specialty Parameters for NO2

As discussed in Section 5.2, all NOX emissions (nitrogen monoxide [NO] and NO2) are modeled because NO converts to NO2 relatively quickly in the atmosphere. Exhaust emissions of NOX consist mostly of NO, typically at about 80 to 90 percent, followed by direct emissions of NO2, typically at about 10 to 20 percent. NO converts to NO2 in the atmosphere by reacting with ambient O3 in the following manner:

NO + O3 → NO2 + O2

In general, the amount of NO2 created from NO emissions is dependent on the ambient O3 available. If more O3 is available, more NO will be converted to NO2, resulting in relatively higher NO2 air concentrations. If less O3 is available, less NO will be converted to NO2, resulting in relatively lower NO2 air concentrations.

35 Sevier Playa Potash Project Resource Report: Air Quality and Climate

For modeling the NOX sources, the EPA guidance memorandum Additional Clarifications Regarding Application of Appendix W Modeling Guidance for the 1-Hour NO2 National Ambient Air Quality Standard (EPA 2011b) was followed. The Tier 3 method in AERMOD was selected, which is the most complex of the three tiers available in AERMOD. Of the two Tier 3 options, Ozone Limiting Method (OLM) and Plume Volume Molar Ratio Method (PVMRM), the former was selected. Tier 3 is a regulatory default option per the GAQM, and is an acceptable methodology to assess impacts from NOx sources. To run Tier 3, AERMOD requires O3 data and the ratio of NO2 to NOX in the emissions for each source, called in-stack ratio (ISR).

Ramboll used hourly O3 data collected from a monitoring station located at Great Basin National Park, Nevada that were concurrent with the meteorological data (December 1, 2011 to November 30, 2012). The park is roughly 87 km (54 miles) west of Sevier Playa, and represents a good approximation of regional ambient O3 for the Project. The data were obtained from EPA’s Air Quality System (AQS) Data Mart (EPA 2017d). The data set met recovery requirements of 75 percent for each quarter. The approximately 350 hours of missing data were replaced by linear interpolation if just one hour was missing, or with the maximum concentration that occurred for that same respective month and hour if two or more consecutive hours were missing.

ISRs vary by equipment piece and process, and data can be found from several resources including EPA, various states, and equipment vendors. The NO2/NOX ISRs for the fire pump, emergency generators, and pump diesel generators were based on data from EPA’s In-Stack Ratio Database for diesel/kerosene-fired reciprocating internal combustion engines (RICE). The default NO2/NOX ISR of 0.50 for stationary sources was used in the absence of more appropriate source-specific information, as recommended in the March 2011 EPA memorandum (EPA 2011b). ISRs for on-road and off-road equipment were based on recommended ratios in guidance from the California Air Pollution Control Officers Association. Specifically, Ramboll used the following ISRs for the Project:

• 0.10 for fire pump, emergency generators, and pump generators

• 0.50 for process dryer

• 0.25 for light/medium duty trucks and cars

• 0.11 for heavy-duty diesel trucks

• 0.20 for off-road construction equipment

Due to their unique use, emergency generators were modeled differently than the other sources at the Project. Per the above EPA guidance, emergency generators are considered intermittent sources because they run less than 100 hours per year. Emissions from these sources were modeled at an annualized emission rate, (that is, 100/8760), for all hours of the year.

5.3.7 Model Input: Specialty Parameters for PM10

The pollutant PM10 represents all particulate matter that is less than or equal to 10 microns in diameter. The distribution of the particle sizes is dependent on the source type. As the plume travels in the atmosphere, some PM10 drops out of the plume in a process called depletion, reducing the PM10 air concentration. The further the plume travels, the more PM10 is removed. Both dry depletion and wet depletion can occur. Wet depletion is caused solely by precipitation that falls through the plume, removing some PM10 in the process.

36 !!!!!!!!!!! !!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!! ± !!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!! !!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!! !!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!! !!!!! !!!!!! !!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!! !!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!! !!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!! !!!!!!!!! !!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!! !!!!!!!!! !!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!! !!!!! !!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!! !!!!! !!!!!!!!!!!! !!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!! !!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!! !!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!! !!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!! !!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!! !!!!! !!!!! !!! !!!!!! !!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!!!! !!!!! !!! !!!!! !!!!! !!! !!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!! !!!!! !!!!!! !! !!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!! !!!!!!!!!!!!!! !!!!!!!!!!!!!! !!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!! !!!!!! !!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!! !!!!! !!!!!!!!!! !!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ! !!!!!!!!!!!!!!!!!!! !!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!! !!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!! !!!!! !!!!!!!!!! !!!!! !!!!! !!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!! !!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!! !!!!! !!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!! !!!!!!!!!!! !!!!!!!!!!!!! !!!!!!! !!!!! !!!!! !!!!!! !!!!!!!!!!! !!!!! !!!!!!!!!!!!! !!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!! !!!!!!!!!! !!!!! !!!!! !!!!!! !!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!! !!!!!!!!!!!!! !!!!! !!!!!! !!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!! !!!!!!! !!!!! !!!!!!!!!!!!! !!!!! !!!!! !!!!! !!!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!!!! !!!!! !!!!! !!!!!!! !!!!! !!!!!!!!!!!!! !!!!!!! !!!!! !!!!!!!!!!!! !!!!!! !!!!! !!!!! !!!!!! !!!!!!! !!!!! !!!!!!!!!!!! !!!!!!!!!!! !!!!! !!!!! !!!!! !!!!! !!!!!!!!!! !!!!!!! !!!!! !!!!!!!!!!!! !!!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!!! !!!!!!! !!!!! !!!!!!!!!!!! !!!!!!! !!!!! !!!!!! !!!!!!!!!!!! !!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!! !!!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!! !!!!!!! !!!!!! !!!!! !!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!! !!!!! !!!!! !!!!!!!!!!!! !!!!!!!! !!!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!!!! !!!!!! !!!!! !!!!! !!!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!!! !!!!!!!!!! !!!!!! !!!!! !!!!! !!!!! !!!!!!!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!!! !!!!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!! !!!!!! !!!!! !!!!!!!!!!!!!! !!!!! !!!!!!! !!!!! !!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!! !!!!!!!!!! !!!!! !!!!! !!!!!!!!!!!!!! !!!!!! !!!!!!!!!! !!!!!!!!!!!!!! !!!!! !!!!!!! !!!!!!!!!!!!!!!! !!!!!! !!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!! !!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!! !!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!! !!!!!!!!!!! !!!!! !!!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!! !!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!! !!!!! !!!!!! !!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!! !!!!!!!!!! !!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!! !!!!!!! !!!!!!!!!! !!!!! !!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!! !!!!!! !!!!! !!!!!! !!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!! !!!!!!! !!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!! !!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!! !!!!!! !!!!! !!!!! !!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!! !!!!!!!!!! !!!!! !!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!! !!!!!!!!!!! !!!!! !!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!! !!!!!! !!!!! !!!!!! !!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!! !!!!! !!!!!!!!!!!! !!!!!!!!!!!!!! !!!!!!! !!!!! !!!!!! !!!!!! !!!!!!!!!!!! !!!!!!!!!!!!! !!!!!! !!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!! !!!!!!!!!!!!! !!!!!! !!!!! !!!!! !!!!!!!! !!!!!!!!!!!! !!!!!!!!!!!! !!!!!!!!!! !!!!! !!!!!!!!!!!! !!!!!!!!!!!!!! !!!!!! !!!!!!!!!!!! !!!!! !!!!! !!!!!! !!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!! !!!!!!!!!!!!!!!!!! !!!!!!!!!!!! !!!!!!!!!!!!!!!!!! !!!!!! !!!!! !!!!! !!!!!! !!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!! !!!!!! !!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!! !!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!!!!! !!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!! !!!!!!!!!! !!!!! !!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!! !!!!! !!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!! !!!!!!!!!!!! !!!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!! !!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!! !!!!!!! !!!!! !!!!!! !!!!!!!!!!!!!!!!!!!!!!! !!!!!!! !!!!!!!!!!!!! !!!!! !!!!!!! !!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!! !!!!!!! !!!!!!!!!!!!! !!!!!! !!!!! !!!!!!! !!!!!!!!!!!!!!!!!!!!!!! !!!!!! !!!!!!!!!! !!!!!!!!!!!!! !!!!!! !!!!!!!!!!!!!!!!!!!!!!! !!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!! !!!!!! !!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!! !!!!!!!!! !!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!!!! !!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!! !!!!!!!!!!!!!!!!!!!! !!!!! !!!!! !!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!! !!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!!! !!!!! !!!!! !!!!!! !!!!!!!!!!!!! !!!! !!!!!!!!!!!!!!!!!! !!!!!! !!!!! !!!!!!!!!!!!!!!!!!! !!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!! !!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!! !!!!!!!! !!!!!!!!!!!!! !!!!!! !!!!!!!!!!! !!!!!!!!! !!!!! !!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!! !!!!!!!! !!!!! !!!!! !!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!! !!!!!!!!!! !!!!! !!!!! !!!!! !!!!! !!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!! !!!!!!!! !!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!! !!!!! !!!!! !!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!! !!!!!!! !!!!! !!!!! !!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!! !!!!! !!!!! !!!!! !!!!!! !!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!! !!!!!! !!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!! !!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!! !!!!!!!!!!! !!!!!!! !!!!! !!!!!! !!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!! !!!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!! !!!!! !!!!! !!!!!!!!!!!!!!!!!!!!! !!!!!! !!!!! !!!!! !!!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!! !!!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!! !!!!!! !!!!! !!!!!!!!!!!!! !!!!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!! !!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!! !!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!! !!!!!! !!!!!!! !!!!! !!!!! !!!!!!!!!!! !!!!!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!! !!!!!! !!!!! !!!!! !!!!!!!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!!! !!!!! !!!!!!! !!!!! !!!!!!!!!!!!!!!! !!!!! !!!!! !!!!!!!!! !!!!!! !!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!! !!!!!! !!!!! !!!!! !!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!! !!!!!!!!!! !!!!! !!!!!!!!!!!!! !!!!!!!!!!!! !!!!!! !!!!!!!!!!! !!!!! !!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!! !!!!!! !!!!! !!!!! !!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!! !!!!!!!!!!!! !!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!! !!!!!!!! !!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!! !!!!!! !!!!! !!!!! !!!!!! !!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!! !!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!! !!!!!!! !!!!!!!!!!!! !!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!! !!!!! !!!!! !!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!! !!!!!!!! !!!!! !!!!! !!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!! !!!!! !!!!! !!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!! !!!!! !!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!! !!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!! !!!!! !!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!! !!!!!!!!!!!!! !!!!! !!!!! !!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!! !!!!! !!!!! !!!!!! !!!!!!!!!!!! !!!!!!!!!!!!! !!!!! !!!!! !!!!! !!!!!!!!!! !!!!!!!!!!!! !!!!!!!!!!!!! !!!!! !!!!! !!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!! !!!!! !!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!! !!!!! !!!!! !!!!!! !!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!! !!!!!! !!!!! !!!!! !!!!!!!!!!!! !!!!!!!! !!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!! !!!!! !!!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!! !!!!! !!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!! !!!! !!!!! !!!!! !!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!! !!!!!!!!!!!!! !!!!!! !!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! Rail Loadout Facility !!!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!!! !!!!! !!!!!!!!!!!!! !!!!! !!!!!!!!!! !!!!!!!!!!!! !!!!!!!!!!!! !!!!!!!! !!!!! !!!!! !!!!!! !!!!!!!!!!!!! !!!!!!!!!!!! !!!!!!!!!! !!!!!! !!!!! !!!!! !!!!!!!!!!!!!! !!!!!! !!!!!!!!!!!!! !!!!!!!!!!!! !!!!! !!!!! !!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!! !!!!! !!!!! !!!!!!!!!!!!!! !!!!!!!!!!!! !!!!!!!! !!!!! !!!!! !!!!!! !!!!!!!!!!!!!!!! !!!!!!!!!!!! !!!!! !!!!! !!!!! !!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!! !!!!!! !!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!! !!!!! !!!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!! !!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!! !! !!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!! !!!!!!!!!!!!!!!!!! !!!!!! !!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!! !!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!! !!!!!!!!!!!!!! ! !!!!! !!!!!!!!!! !!!!! !!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!! !!!!!! !!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!! !!!!!!!!!! !!!!! !!!!!!!!!!!!! !!!!!!!!!!!! !!!! !!! !!!!!! !!!! !!!!! !!!!! !!!!!! !!!!!!!!!!!!! !!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!! !!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!! !!!!!!! !! !!!!! !!!!!!!!!!!!!!!!!!!! !!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!! !!! !!!!!! !!!!! !!!!! !!!!!!!!! !!!!!!!!!!!!!! !!!!!!!!! !!!!!!!!!!!!! !!!!!! !!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!! !!! !!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!! !!! !!!!! !!!!! !!!!! !!! !!!!! !!!!! !!! !!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!!!! !! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!! !!!! !!!!! !!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!! !!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!! !!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!! !!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!! !!! ! !!!!!!!!!!!!!!!!!! !!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !! !! !!!!!! !!! !! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !! !!! !!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!! !!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!! !!!!!! !! !! !!! !!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!! !!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!! !!!!!!!! ! !! !!! !!!!!!!!!! !!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!! !! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!! !!!!!!! ! !! !!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!! !!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!! ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!! !!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!! !!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!! !!!!!!! !!!!!!!!!! !!!!! !!!!!!!!!!!!! !!!!! !!! !! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!! !!!!! !!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!! !!! !!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!! !!!!!!!!! !!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!! !!!!!!!!!!!!! !!!!!! !!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!! !!!! !!!!!!!!!!!! !!!!!!!!!!!!!!!! !!!!!! !!!!!! !!!!!!!!!! !!!!! !!!!!! !!!!!!!!!!!!!!! !!! !!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!!! !!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!!!! !!!! !!!!!!!!!!!!!!!!!!!! !!!!!!!!!! !!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!! !!!!! !!!!! !!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!! !!!!!!!! !!!!!!!! !!!!!!!!!!! !!!!!!! !!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!! !! !!!!!!!!!! !!!!!!! !! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!Legend !!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! Ambient Air Boundary !!!!!!!!!!!!!!! ! Roadway Receptors !!!!!!! Gridded Receptors ! (1 km & 200 m spacing) Gridded Receptors ! (2 km, 500 m, & 100 m spacing)

0 25 km

Source: Modified Figure A3 from Ramboll (2019a) Sevier Playa Potash Project Resource Report: Air Quality and Climate

THIS PAGE INTENTIONALLY LEFT BLANK

38 Sevier Playa Potash Project Resource Report: Air Quality and Climate

AERMOD has the capability to simulate the depletion process if a particle size distribution is available. Ramboll provided the model with a particle size distribution for the Project’s PM10 fugitive dust sources using default parameters supplied by UDAQ (Table 24). The particle size is the mean mass-weighted diameter and the mass fraction is the fraction of the total PM10 represented by that particle size category. Density is the amount of mass per unit volume.

Table 24 Particle Size Distribution

Particle Size, Diameter Particle Density Source Type Mass Fraction (microns) (g/cm3) 0.10 1.25 2.2 Unpaved Road 0.90 6.25 2.2 0.15 1.25 2.2 Paved Road 0.85 6.25 2.2 0.15 1.25 2.2 Batch Drop 0.42 3.75 2.2 0.43 7.5 2.2 0.15 1.25 2.2 Pile Wind Erosion 0.85 6.25 2.2 0.07 1.25 2.2 Screening 0.93 3.75 2.2 0.06 1.25 2.2 Crushing 0.94 3.75 2.2

Following a specific request by EPA for the Project, dry depletion was applied only to fugitive dust sources (lines, volumes, and areas) for PM10. Dry depletion was not applied to stationary sources for PM10, nor was it applied to any PM2.5 sources. Wet depletion was not included for any sources because of the lack of precipitation data, a required parameter. Wet depletion would be minimal in any event, as the Project would be located in an area that is semiarid and does not receive much precipitation (Section 6.1).

5.3.8 Air Dispersion Model Limitations

An air dispersion model approximates the dispersion of pollution from a source to the surrounding environment, estimating air concentrations at specific locations. It does this by applying mathematical algorithms and assumptions to source inputs, meteorological data, and receptor information.

AERMOD is a steady-state, instantaneous transport plume model, meaning that it transports the plume downwind from the source to the far edge of the receptor grid in each hour. In the Project’s case, this distance from the source to the edge of the grid is over 30 km (19 miles). As the plume is transported downwind, it spreads out vertically and horizontally, similar to a cone. The width, depth, and centerline height of the plume depend on the source characteristics, stability of the atmosphere, wind speed, and other meteorological parameters. The model calculates the air concentration for each receptor the plume encounters. The plume itself is based on a Gaussian distribution, meaning the highest concentrations occur along the centerline of the plume, and decrease to near zero as the outside edges of the plume are approached in both the vertical and horizontal directions. AERMOD transports the plume downwind from the source to the edge of the grid in one hour. This does not reflect what actually happens to the movement of pollution plumes in the real world. In addition, the Gaussian distribution is a time-averaged

39 Sevier Playa Potash Project Resource Report: Air Quality and Climate estimate of a plume and does not provide an accurate, real-world depiction of a pollutant cloud, which would vary based on meteorological conditions, plume characteristics, and interactions with the surrounding environment.

Physical source inputs to the model are approximations of the actual source, especially for volume, line, and area sources. The emissions themselves are also estimates, as described in Section 5.2.5, as well as the source locations, timing, and operational hours. The meteorological data approximate the stability of the atmosphere, and provide temperature, wind speed, and wind direction. These data are assumed to be constant over the entire grid for each hour modeled. This is not necessarily accurate, as weather can change with distance and direction, especially under the influence of varying terrain. However, steady- state atmosphere is an assumption made by AERMOD. The receptor data provide the model information about terrain and its undulations in order to approximate the interactions of the plume with hills.

All of these approximations, assumptions, and model algorithms create outputs that only estimate effects of emissions from a source. The air dispersion models are designed to be conservative to protect human health and the environment, but can be prone to over-prediction. AERMOD can predict concentrations 2 to 10 times higher than monitored concentrations, if not greater (EPA 2017e). Over-predictions can occur especially during periods with low wind speeds and for near-surface fugitive sources. Regardless of the limitations, air dispersion modeling is a relatively inexpensive method to predict the effects of air pollution from an existing source or a source that has yet to be constructed. It provides information about effect to air quality for NEPA, especially when comparing effects among alternatives. It is the standard method employed to estimate effects from a project for the purposes of comparison with applicable standards.

5.4 Nearby Background Sources

Emissions from nearby sources may add to the effects of the Project by increasing air pollutant concentrations in the analysis area. To account for this, Ramboll modeled NOX and CO sources from three facilities: Graymont Cricket Mountain facility, Intermountain Power Plant, and Kern River Gas Transmission Station. Model input data for these facilities were provided by UDAQ, and are summarized in Table 25. No nearby background sources of PM10, PM2.5, or SO2 were included in the model as the respective emissions from these sources were relatively small. This is assessed by taking the ratio of background source emissions (in tpy) to the distance between the Project and the background source. If this ratio is less than or equal to 10, the emissions from background source is considered to have a minimal effect on the Project. The modeling threshold ratio of 10 was provided by UDAQ, and is based on the same threshold used in screening for air quality related values analyses (Section 7.2.1.5).

Table 25 Nearby Background Source Summary

Distance from Sevier Modeled Emissions (tpy) Source Playa Sources NOX CO 6 points and Graymont Cricket Mountain Lime Plant 21 km (13 miles) E 2988.0 472.9 3 volumes Intermountain Power Plant 76 km ( 47 miles) NE 7 points 40,761.5 -- Kern River Gas Transmission Station 56 km (35 miles) ESE 1 point 83.4 --

40 Sevier Playa Potash Project Resource Report: Air Quality and Climate

5.5 Background Air Concentrations

Monitoring of air pollutants provides information about air quality at a specific location. The measured air quality at a monitoring station is affected by anthropogenic and natural sources located in the immediate proximity as well as in the general region, and from distant locations. The monitored values can be used to represent “background concentrations”, the purpose of which is to provide a baseline air quality to which modeled concentrations are added.

The Project would be located in a rural area with few neighboring sources and no industrial facilities in the immediate vicinity. Data from particulate monitors located on the Sevier Playa and selected regional gaseous monitors located in similar surroundings were used for the modeled background concentrations. Table 26 summarizes the resultant background concentrations by air pollutant and averaging period, as well as the selected monitoring station. Individual pollutants are discussed in the following subsections.

Table 26 Monitored Background Concentrations Used in the Modeling

Averaging NAAQS Monitored Monitoring Station Monitoring Station Pollutant Period Value (μg/m3) ID Location

PM2.5 Annual 4.1 CPM Monitor South End of Sevier Playa (1) PM2.5 24-hour 11.8 CPM Monitor South End of Sevier Playa (2) PM10 24-hour 97.4 CPM Monitor South End of Sevier Playa (3) NO2 Annual 3.8 AQS 49-007-1003 Price (4) NO2 1-hour 58.9 AQS 49-007-1003 Price CO 1-hour 3434.8(6) AQS 49-049-0002 North Provo CO 8-hour 2747.9(6) AQS 49-049-0002 North Provo (5) SO2 1-hour 18.0 AQS 49-035-3006 Salt Lake City, Hawthorne (6) SO2 3-hour 12.8 AQS 49-035-3006 Salt Lake City, Hawthorne (6) SO2 24-hour 5.8 AQS 49-035-3006 Salt Lake City, Hawthorne (3) SO2 Annual 1.5 AQS 49-035-3006 Salt Lake City, Hawthorne (1) 98th percentile from one year of data recorded at the monitoring station on the Sevier Playa between August 2013 and July 2014. (2) Second highest value from one year of data recorded at the monitoring station on the Sevier Playa between August 2013 and July 2014. See Table 27 and Section 5.5.1 for the seasonal concentrations used with the modeled concentrations. (3) Maximum annual average concentration based on data from December 2011 through November 2014. (4) Average of the 98th percentile 1-hour daily maximum concentration based on data from December 2011 through November 2014. See Table 28 and Section 5.5.4 for seasonal hour concentrations that were entered directly into the model for the 1-hour NO2 analysis. (5) Average of the 99th percentile 1-hour daily maximum concentration of 2012, 2013, and 2014. (6) Highest second-high concentration of 2012, 2013, and 2014.

5.5.1 Air Pollutants: PM10 and PM2.5

CPM monitored PM10 and PM2.5, as well as meteorological parameters, at the south end of the Sevier Playa from August 1, 2013 to July 31, 2014 (Figure 3). The monitoring was performed with continuous

41 Sevier Playa Potash Project Resource Report: Air Quality and Climate samplers (samplers that run 24-hour per day, 7 days per week) and followed PSD monitoring guidelines (EPA 1987).

3 The second-high 24-hour PM10 concentration of 97.4 μg/m was recorded on a relatively high-wind day that occurred during the monitoring year. The 24-hour PM10 concentration is compared to the NAAQS for attainment designation purposes for an AQCR (see Section 4.1).

A seasonal distribution analysis was performed for 24-hour PM10 concentrations and is presented in Table 27. Relatively large fluctuations in concentrations are shown from season to season, with the lowest concentration occurring in the winter and the highest concentration occurring in the spring. These seasonal concentrations were used as the background concentrations added to the model concentrations from the Project by season.

th 3 The 98 percentile 24-hour PM2.5 concentration was 11.8 μg/m and the annual mean concentration was 3 4.1 μg/m . These PM2.5 concentrations are compared to the NAAQS for attainment designation purposes for an AQCR (see Section 4.1). These concentrations for these pollutants and averaging times also represent the background concentrations that are added to the respective modeled concentrations from the Project.

Table 27 Highest 24-Hour PM10 Concentrations by Month and Season

Highest 24-Hour Highest 24-Hour Concentration1 for Month Concentration1 for Season Month Season (μg/m3) (μg/m3) December 11.8 January Winter 15.2 16.4 February 16.4 March 17.8 April Spring 21.3 97.4 May 97.4 June 36.3 July Summer 53.9 53.9 August 17.1 September 34.7 October Fall 49.4 49.4 November 29.3 1 3 The maximum (first-highest) 24-hour PM10 concentration for the monitoring year is 135.7 μg/m . Per EPA guidance, this concentration is excluded when considering background concentration. The concentrations listed in the table are the highest concentrations for the month or season after the 135.7 μg/m3 concentration is eliminated from the data set.

42 Source: Modified Figure 2 from Ramboll (2019a) Sevier Playa Potash Project Resource Report: Air Quality and Climate

THIS PAGE INTENTIONALLY LEFT BLANK

44 Sevier Playa Potash Project Resource Report: Air Quality and Climate

5.5.2 Air Pollutant: CO

For CO, the North Provo monitoring station was selected and data from 2012 through 2014 were analyzed. The second highest concentration was obtained for each year for 1-hour and 8-hour averaging periods. From these three respective second-high values, the highest concentration was selected for the averaging period (the highest second-high). The highest second-high concentrations are compared to the NAAQS for attainment purposes for an AQCR (see Section 4.1), and represent the background concentrations for CO that are added to the modeled concentrations from the Project.

5.5.3 Air Pollutant: SO2

For SO2, data collected from 2012 through 2014 at the Hawthorne monitoring station were chosen for analysis. For the 1-hour averaging period, the 99th percentile concentration was selected for each year, and the average of these three values was used for the background. For the 3-hour and 24-hour averaging periods, the second highest concentration was obtained for each year. From these three respective values, the highest concentration was selected for each averaging period, (the highest second-high). For the annual averaging period, the maximum annual concentration of the three years was chosen. These four representative concentrations are compared to the applicable NAAQS for attainment purposes for an AQCR (Section 4.1), and represent the background concentrations for SO2 that are added to the modeled concentrations from the Project

5.5.4 Air Pollutant: NO2

For NO2, the Price monitoring station was selected and data from December 1, 2011 through November 30, 2014 were downloaded and summarized. The first monitoring year matches the meteorological data used in the modeling analysis. For the 1-hour averaging period, the 98th percentile concentration was selected for each year, and the average of these three values taken. For the annual averaging period, the maximum concentration of the three years was taken. These two representative concentrations are compared to the NAAQS for attainment purposes for an AQCR (see Section 4.1).

Hourly air pollutant concentrations can fluctuate through the course of the day and through the course of the year. To represent these fluctuations in NO2 background, the 1-hour monitored data were processed based on the hour of the day and season of the year. Following EPA’s Modeling Guidance for the 1-hour NO2 National Ambient Air Quality Standard (EPA 2011b), the data were split into the four seasons, with December, January, and February being winter; March, April, and May being spring; June, July, and August being summer; and September, October, and November being fall. This results in three winters, three springs, three summers, and three falls within the full data set. For each hour of the day (1 to 24) and for each individual season of a specific year, the third-highest concentration was selected, and then the three respective values were averaged. For example, the third highest concentration for Hour 1 for each of the three winters was selected, and then these three values were averaged to obtain the representative value for the winter season for Hour 1. This process was performed for all four seasons and for all 24 hours of the day over the three monitoring years, creating a data set of 96 values. The resultant 96 seasonal-hour concentrations are listed in Table 28. These resultant values represent background concentrations that fluctuate across seasons and hour of the day, and the 96 data values were entered directly in the model. Inside AERMOD, the background concentrations are added to the corresponding modeled concentration from the Project by season and hour such that the output from the model represents the total concentration.

45 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 28 Mean Seasonal Hour 3rd Highest NO2 Concentrations for Price

(1,2) (1,3) (1,4) (1,5) Hour of Winter Spring Summer Fall Day ppb μg/m3 ppb μg/m3 ppb μg/m3 ppb μg/m3 1 18.0 33.8 17.0 32.0 28.3 53.2 16.0 30.1 2 17.3 32.5 14.3 26.9 25.0 47.0 16.0 30.1 3 17.3 32.5 15.0 28.2 18.7 35.2 14.7 27.6 4 15.0 28.2 11.7 22.0 17.3 32.5 17.0 32.0 5 15.3 28.8 12.3 23.1 15.3 28.8 10.3 19.4 6 15.7 29.5 10.3 19.4 16.3 30.6 9.0 16.9 7 14.3 26.9 13.3 25.0 16.7 31.4 12.3 23.1 8 18.0 33.8 14.0 26.3 15.0 28.2 13.7 25.8 9 15.7 29.5 13.0 24.4 12.3 23.1 12.7 23.9 10 15.3 28.8 6.7 12.6 8.7 16.4 12.7 23.9 11 15.0 28.2 4.3 8.1 5.7 10.7 9.7 18.2 12 13.7 25.8 3.0 5.6 4.3 8.1 6.7 12.6 13 13.0 24.4 2.7 5.1 3.0 5.6 5.3 10.0 14 12.3 23.1 2.3 4.3 3.3 6.2 3.7 7.0 15 12.3 23.1 2.3 4.3 3.7 7.0 4.0 7.5 16 12.0 22.6 2.7 5.1 3.3 6.2 4.0 7.5 17 13.3 25.0 3.3 6.2 3.3 6.2 4.7 8.8 18 16.3 30.6 3.0 5.6 5.0 9.4 7.7 14.5 19 15.7 29.5 4.3 8.1 8.3 15.6 7.3 13.7 20 15.7 29.5 5.3 10.0 9.3 17.5 9.0 16.9 21 14.0 26.3 7.3 13.7 11.7 22.0 11.7 22.0 22 15.3 28.8 11.0 20.7 19.3 36.3 13.7 25.8 23 13.0 24.4 12.7 23.9 23.0 43.2 19.0 35.7 24 15.0 28.2 16.0 30.1 27.7 52.1 16.7 31.4 (1) The mean concentration for each hour and season (for example, all three winters for each respective hour of the day were averaged). (2) The three winters are December 2011 to February 2012, December 2012 to February 2013, and December 2013 to February 2014. (3) The three springs are March to May 2012, March to May 2013, and March to May 2014. (4) The three summers are June to August 2012, June to August 2013, and June to August 2014. (5) The three falls are September to November 2012, September to November 2013, and September to November 2014.

5.5.5 Background Concentration Limitations

Monitoring of pollutants, especially gaseous pollutants, is relatively expensive and not many monitors with current data exist for any given region. In addition, monitoring is more frequent in and around cities and towns as well as near industrial facilities, thus data collected by those monitors are affected by local sources. For this Project, which would be located in a rural region without any nearby industrial facilities, an attempt was made to select monitors that were as rural and isolated from localized sources as possible, as well as monitors that were identified by EPA as “regional scale”. The selected monitors for CO, NO2,

46 Sevier Playa Potash Project Resource Report: Air Quality and Climate

and SO2 are located at distances of about 200 to 225 km (124 to 140 miles) north-northeast to northeast of the Sevier Playa. It is unknown if the same concentrations of pollutants would be measured if these types of monitors were installed around the playa. Isolating the selected monitors to regional and near-rural type locations, where available, allow for some confidence that the values are representative. However, the CO and SO2 monitoring stations are located in maintenance and nonattainment areas, respectively, and not in an attainment / unclassified area such as where the Project would be located. As such, these stations are not truly representative of the conditions near the analysis area, which would likely have lower background values for these pollutants. They are the closest available monitoring stations for those pollutants for the years of 2012 to 2014 and represent a conservative background (that is, a higher concentration), so that the final model result produces a higher concentration than is likely the case in the analysis area.

The gaseous pollutant data collected in 2012 to 2014 were applied to the model as if they occurred in the analysis area for the year modeled for that pollutant (for example, 2020 for 1-hour NO2). In addition, the PM10 and PM2.5 data that were collected at the south end of the Sevier Playa in 2013 and 2014 were applied to the model as if they occurred in the analysis area for the year modeled (that is, year 2025). It cannot be known if these background pollutant concentrations would be the same in the future. However, it is standard procedure to apply historical background concentrations to modeled concentrations to compare to the NAAQS, despite this uncertainty. 6.0 Affected Environment

This section describes the affected environment for air quality and climate. The information presented is based on published literature, publicly available meteorological and air quality data for the general region, Sevier Playa meteorological and air quality data, the Modeling Report (Ramboll 2019a) for the Project, and other resources listed in the remainder of this section.

6.1 Regional Climate

The west-central region of Utah has a mid-latitude, semi-arid climate, characterized by wide diurnal and seasonal temperature variations, and relatively meager precipitation. Evaporation exceeds annual precipitation. The air is generally dry with relatively sunny days and clear nights. The climate is driven by several factors: the mid-latitude location in the continental interior distant from major moisture sources, the placement on the lee side of major mountain ranges, and the relatively high mean sea level elevation ranging from 4,000 to 6,000 feet. As storms move across the Cascade and Sierra Nevada Mountain Ranges, moisture is removed, leaving little for the area. Precipitation in the region arrives in the form of rain from localized, sometimes heavy, thunderstorms or showers during the warmer months (April through October), and snow or rain from synoptic (large-scale) systems during the cooler months (November through March). The annual Southwest Monsoon typically begins in mid-July and stretches into September, and is the primary mechanism for generating precipitation during these months. The region experiences four distinct seasons. The summers are relatively warm to hot, with mean high temperatures ranging from 85 to 95ºF. The winters are relatively cold, with mean low temperatures ranging from 11 to 15ºF (National Oceanic and Atmospheric Administration [NOAA] 1989, NOAA 2015).

For the Black Rock station, located about 15 km (9 miles) east of the Project, meteorological parameters for the 30-year climate period of 1987 to 2016 show that the annual mean temperature is approximately 50ºF, with monthly mean temperatures ranging from 28ºF for January and December to 74ºF for July. Around 61 days per year experience temperatures above 90ºF, with maximum temperatures above 100ºF expected once or twice per year. About 16 days per year experience daily maximum temperatures below

47 Sevier Playa Potash Project Resource Report: Air Quality and Climate

32ºF, with about 12 days recording temperatures below 0ºF. The maximum temperature recorded over the 30-year period was 105ºF, while the minimum temperature was -37ºF. Table 29 and Table 30 catalog the 30-year monthly and annual mean and extreme temperature statistics for Black Rock (NOAA 2018).

Regional precipitation varies substantially from year to year, as well as across the year. Over the 30-year period, annual precipitation recorded at Black Rock ranged from 4.24 to 13.41 inches, with an annual mean of 8.91 inches. On average, higher precipitation totals are recorded in the months of April, May, and October compared to the other months of the year. Annual snowfall varies substantially over the period, ranging from less than 10 inches to over 79 inches, with the majority of the snow in the winter months (December, January, and February). The highest extreme daily precipitation amount was 1.87 inches, the highest maximum daily snowfall was 20 inches, and the maximum snow depth measured was 24 inches. Table 29 and Table 30 list the 30-year monthly and annual mean and extreme precipitation statistics for Black Rock (NOAA 2018).

Table 29 Mean Temperature and Precipitation Summary for Black Rock

Mean Mean Maximum Mean Minimum Mean Temperature Temperature Temperature Precipitation Mean Snowfall Period1 (ºF) (ºF) (ºF) (inches) (inches) January 27.7 40.9 14.6 0.62 6.0 February 33.9 47.8 20.0 0.72 4.0 March 43.1 60.1 26.2 0.85 3.0 April 49.4 67.3 31.5 0.93 1.0 May 57.6 76.4 38.8 0.90 0.0 June 67.0 87.1 46.8 0.51 0.0 July 74.3 93.6 55.0 0.60 0.0 August 71.9 90.7 53.2 0.83 0.0 September 62.5 81.7 43.3 0.70 0.0 October 50.8 69.0 32.7 0.95 0.0 November 38.1 53.5 22.6 0.63 2.0 December 27.5 40.9 14.2 0.75 7.0 Annual 50.3 67.4 33.2 8.91 24.3 1 Data Years 1987 to 2016.

Table 30 Extreme Temperature and Precipitation Summary for Black Rock

Extreme Daily Extreme Daily Extreme Daily Extreme Maximum Extreme Minimum Snow Depth Snowfall Precipitation Period(1) Temperature (ºF) Temperature (ºF) (inches) (inches) (inches) January 68 -23 24 17 1.07 February 74 -28 10 6 1.00 March 86 1 11 19 1.75 April 93 11 4 9 1.00 May 98 17 0 4 1.00 June 105 26 0 0 1.51 July 105 32 0 0 1.87

48 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 30 Extreme Temperature and Precipitation Summary for Black Rock

Extreme Daily Extreme Daily Extreme Daily Extreme Maximum Extreme Minimum Snow Depth Snowfall Precipitation Period(1) Temperature (ºF) Temperature (ºF) (inches) (inches) (inches) August 102 29 0 0 1.12 September 97 23 0 0 1.51 October 89 8 3 3 1.57 November 80 -19 8 8 1.04 December 67 -37 24 20 1.50 Annual 105 -37 24 20 1.87 1 Data Years 1987 to 2016.

6.2 Regional Air Quality

The air quality of any region is controlled primarily by the magnitude and distribution of pollutant emissions and the regional climate. In the mountainous western United States, topography is particularly important in channeling pollutants along valleys, creating upslope and downslope circulation patterns that may entrain airborne pollutants and block the flow of pollutants toward certain areas. Local effects are superimposed on the general weather regime and are the most influential when the large-scale wind flows are weak. In turn, large-scale flows can dominate the region and overpower local effects. For example, large high pressure systems can remain stationary over the area for weeks, resulting in stagnant conditions that trap pollutants and degrade air quality and visibility. In contrast, frontal systems can generate high- velocity winds that can ventilate the area and reduce pollutant concentrations, or these same systems can entrain large amounts of dust from exposed areas and decrease air quality and visibility.

Sources of air pollutants affecting the region are both natural and anthropogenic. Natural events include wildfires and high-wind dust storms. Natural events generally are short-lived, lasting from several hours to several days to several weeks. These events may affect human health and the environment, but generally are considered part of the natural physical environment. Anthropogenic sources operate over long periods and may affect human health and the environment. Emissions from distant anthropogenic sources, such as power plants, oil and gas facilities, industrial activities, and vehicle travel and tailpipes, may affect regional air quality. The long-range transport of pollutants from these sources is governed by local topography, regional wind flows, and the relative distance between the source location area and affected region. Existing air pollutant emission sources within the immediate vicinity of the Project include traffic tailpipe emissions of CO, NOX, PM10, PM2.5, SO2, and VOCs. PM as fugitive dust is generated by agricultural activities, vehicle movement along unpaved and paved roads, and paved road sanding during winter months.

The effects of both natural events and anthropogenic activities can be measured by air quality monitors. Nation-wide air quality monitoring data are available from the EPA (2017d). Air quality data collected in the general region of the Project were reviewed and data reflecting concentration levels for a rural-type location extracted. The monitoring stations selected were identified as regional-scale monitors. Monitors identified as industrial-scale or located in urban areas were not considered representative of rural pollutant concentrations.

Table 31 summarizes the criteria pollutant concentrations measured at these regional stations in units of ppb, ppm, or μg/m3 for the individual pollutant and averaging time for data years 2012 to 2016. The monitors measured marginal to good air quality, with concentrations below the NAAQS for all criteria

49 Sevier Playa Potash Project Resource Report: Air Quality and Climate

pollutants except for O3 and 24-hour PM2.5 for a few stations. Note that some stations did not achieve a data recovery rate of at least 75 percent, as required by monitoring regulations, for certain years. These instances are noted in the table with an “I” next to the concentration for that station and year. The pollutant concentrations for the incomplete years are listed for informational purposes only.

Table 31 Regional Air Quality Data

Pollutant Unit Station ID Station Name 2012 2013 2014 2015 2016 1-hour 49-047-5632 Uintah County 2 5 ------(A) ppb SO2 49-035-3006 Hawthorne 9 6 6 5 13 (I) 3-hour 49-047-5632 Uintah County 1.3 2.8 ------(B) ppb SO2 49-035-3006 Hawthorne 4.4 4.8 4.9 13.0 3.3 (I) 24-hour 49-047-5632 Uintah County 0.5 0.9 ------(B) , (F) ppb SO2 49-035-3006 Hawthorne 1.7 2.1 2.2 2.2 2.0 (I) Annual 49-047-5632 Uintah County 0.0 0.0 ------(F) ppb SO2 49-035-3006 Hawthorne 0.6 0.5 0.5 0.3 0.8 (I) 49-007-1003 Price 35 27 30 -- 18 (I) 49-013-0002 Roosevelt 33 52 34 32 (I) 29 49-013-1001 W. Fruitland 18 20 ------1-hour 49-013-7011 Myton -- 30 23 (I) 21 17 (C) ppb NO2 49-047-5632 Uintah County 12 44 ------49-035-3006 Hawthorne 54 62 48 52 59 49-047-7022 Vernal-Whiterock -- 20 (I) 10 (I) 9 12 49-053-0007 Hurricane 22 28 24 (I) 14 (I) 32 (I) 49-007-1003 Price 3.8 3.7 3.3 -- 2.9 (I) 49-013-0002 Roosevelt 4.4 9.0 4.7 6.4 (I) 3.6 49-013-1001 W. Fruitland 2.3 2.3 ------Annual 49-013-7011 Myton -- 3.9 3.1 (I) 3.3 2.8 ppb NO2 49-047-5632 Uintah County 0.9 2.5 ------49-035-3006 Hawthorne 16.3 18.0 14.1 15.6 18.1 (I) 49-047-7022 Vernal-Whiterock -- 2.2 (I) 1.0 (I) 1.4 1.3 49-053-0007 Hurricane 2.5 3.1 2.6 (I) 1.2 (I) 3.1 (I) 32-033-0101 Great Basin National Park 15 20 22 24 17 (I) 49-047-5632 Uintah County 145 35 (I) ------24-hour 3 (I) (B) µg/m 49-035-3006 Hawthorne 61 105 87 64 78 PM10 49-053-0007 Hurricane -- -- 34 28 (I) 38 49-053-0130 Zion National Park 29 21 28 18 -- 49-047-5632 Uintah County 20.2 18.0 (I) ------

24-hour 3 49-035-3006 Hawthorne 26.0 52.0 39.8 28.8 42.0 (D) µg/m PM2.5 49-053-0007 Hurricane -- -- 9.2 10.8 (I) 8.4 49-053-0130 Zion National Park 12.1 11.6 ------49-047-5632 Uintah County 5.2 5.9 (I) ------Annual µg/m3 49-035-3006 Hawthorne 8.3 10.6 7.7 7.4 8.2 PM2.5 49-053-0007 Hurricane -- -- 4.0 4.6 (I) 3.9

50 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 31 Regional Air Quality Data

Pollutant Unit Station ID Station Name 2012 2013 2014 2015 2016 49-053-0130 Zion National Park 6.5 5.1 ------32-033-0101 Great Basin National Park 0.076 0.074 0.064 0.066 0.063 49-053-0130 Zion National Park 0.075 0.070 0.065 0.066 0.064 49-053-0007 Hurricane -- 0.069 0.066 0.069 0.062 49-007-1003 Price 0.073 0.067 0.064 0.069 0.067 49-013-0002 Roosevelt 0.069 0.104 0.062 0.060 (I) 0.081 8-hour (E) ppm 49-013-1001 W. Fruitland 0.070 0.069 ------O3 49-013-7011 Myton -- 0.108 0.067 (I) 0.066 0.085 49-047-5632 Uintah County 0.072 0.082 (I) ------49-035-3006 Hawthorne 0.078 0.077 0.072 0.081 0.074 49-047-7022 Vernal-Whiterock -- 0.095 0.064 (I) 0.068 0.081 49-053-0007 Hurricane 0.059 (I) 0.069 0.066 0.069 0.062 49-047-5632 Uintah County 3.8 2.3 (I) ------1-hour ppm 49-049-0002 North Provo 2.7 3.0 2.7 2.9 2.2 CO (B) 49-035-3006 Hawthorne 3.6 2.7 2.9 3.3 3.0 (I) 49-047-5632 Uintah County 1.9 2.1 (I) ------8-hour ppm 49-049-0002 North Provo 2.0 2.4 1.9 2.2 1.4 CO (B) 49-035-3006 Hawthorne 2.7 1.9 1.8 1.8 1.4 (I) (A) 99th percentile of 1-hour daily maximum concentrations; NAAQS comparison based on a 3-year average (B) 2nd-highest concentration (C) 98th percentile of 1-hour daily maximum concentrations; NAAQS comparison based on a 3-year average (D) 98th percentile of 24-hour maximum concentrations; NAAQS comparison based on a 3-year average (E) 4th-highest daily maximum 8-hour concentration; NAAQS comparison based on a 3-year average (F) Standard revoked in 2010. Listed for informational purposes. (I) Incomplete data collection for the year, with recovery less than 75%.

6.2.1 Carbon Monoxide

CO is a colorless and odorless gas. It is emitted from fuel combustion sources, the majority being mobile vehicles. CO can be harmful by reducing oxygen delivery to the body's organs and tissues and can cause death at extremely high concentrations. Data collected at three regional monitors indicate CO concentrations well below the 1-hour and 8-hour NAAQS (Table 31).

6.2.2 Sulfur Dioxide

SO2 is a highly reactive gas, part of the oxides of sulfur group, and is emitted primarily from fossil fuel combustion. Sources of SO2 include power plants, industrial facilities, industrial processes extracting metal from ore, and heavy mobile equipment burning sulfur-containing fuels. Studies link SO2 with adverse effects on the respiratory system. Data collected at two regional monitors indicate SO2 concentrations well below the 1-hour, 3-hour, 24-hour and annual NAAQS (Table 31).

6.2.3 Nitrogen Dioxide

NO2 is a highly reactive gas that is part of the NOX group, which also includes NO and nitrogen trioxide (NO3). NO2 forms relatively quickly in emissions from fuel combustion from stationary sources and

51 Sevier Playa Potash Project Resource Report: Air Quality and Climate

mobile equipment by reaction of NO emissions with ambient O3. Fuel combustion sources also directly emit NO2. In the atmosphere, the radical NO3 can form by reaction of NO2 with O3, and then convert back to NO2 by reaction of NO3 with ultraviolet light. NO2 is also associated with O3 and fine particulates (PM2.5) through photochemical transformation and secondary formation of nitric acid (HNO3). Studies link NO2 with adverse effects on the respiratory system. Data collected at eight regional monitors show NO2 concentrations below the 1-hour and annual NAAQS (Table 31).

6.2.4 Particulate Matter

PM consists of small particles and liquid droplets and has components that encompass acids, organic matter, metals, soil, and dust. PM is emitted from material handling, processing, vehicle travel, and fuel combustion sources, as well as from natural sources such as wind-blown dust. PM2.5 can be directly emitted, or can be created by secondary formation from gases emitted by industrial facilities and vehicles. Studies link PM, and especially PM2.5, with adverse health effects to the heart and respiratory systems.

In dry areas like Utah, windblown dust may be a substantial air pollution problem. From spring through fall, high winds can combine with dry surface conditions to cause dust storms. These dust storms can lead to extremely high levels of PM in the air. Much of this PM is small enough to be considered harmful to human health. The analysis area is semi-arid and contains dry lakebeds (playas) that are remnants of Pleistocene Lake Bonneville. The lakebeds have generally been dry throughout recorded history and are a source of wind-blown dust that frequently affects the Wasatch Front. Windblown dust cannot be completely controlled or avoided. Under air pollution laws, most windblown dust storms are considered “natural events” and are regulated differently than other sources of air pollution.

Five regional background stations monitor PM10 with all measured concentrations below the 24-hour NAAQS. Four regional stations monitor PM2.5, three of which measured concentrations below the 24- hour NAAQS and one of which measured concentrations above the 24-hour NAAQS. All four of the PM2.5 stations measured concentrations below the annual NAAQS (Table 31).

CPM monitored PM10 and PM2.5 at Sevier Playa. These data are more representative of the analysis area than data from regional monitoring stations (Section 6.4).

6.2.5 Ozone

Ground-level O3 is created by chemical reactions between NOX, VOCs, and ultraviolet radiation. Sources of NOX and VOCs include industrial facilities, power plants, gas plants, motor vehicles, piping leaks, and chemical emissions. Natural sources also contribute to O3 formation. Studies link O3 with adverse effects on the respiratory system. Eleven monitors measure O3 in the region, with four stations showing concentrations above the 8-hour NAAQS (Table 31).

6.3 Local Topography of the Analysis Area

The analysis area is located on BLM, state, and private lands in Millard County, in the Sevier Desert of southwestern Utah (Figure 1). The Sevier Playa is located in the Basin and Range physiographic province, which consists of alternating down-dropped valleys (grabens) and uplifted mountains (horsts) caused by crustal extension. The Sevier Playa is located in a graben.

6.4 Local Air Quality and Meteorology

The air pollutants PM10 and PM2.5 were monitored at the south end of Sevier Playa (Figure 3) by CPM from August 2013 to July 2014. These data are summarized in Table 32 in comparison to the NAAQS.

52 Sevier Playa Potash Project Resource Report: Air Quality and Climate

th The second-high 24-hour PM10 concentration is about 65 percent of the NAAQS, while the 98 percentile 24-hour and the annual PM2.5 concentrations are about 34 percent of the respective NAAQS.

Table 32 CPM Air Quality Monitoring Data, August 2013 to July 2014

Pollutant Averaging Time Statistic (A) Concentration (μg/m3) NAAQS (μg/m3)

nd (B) PM10 24-Hour 2 High 97.4 150 th PM2.5 24-Hour 98 Percentile 11.8 35

PM2.5 Annual Mean 4.1 12 Source: Ramboll 2018b (A) For comparison to the applicable NAAQS. See Table 4 for the application of the statistical form. (B) This is the second highest concentration for the monitoring year, and represents a relatively windy day.

Meteorological data were collected at the south end of Sevier Playa by CPM from December 2011 to November 2012 (Figure 3). CPM provided these data to BLM’s air contractor for summarization purposes for this report. Table 33 presents summaries of monthly and period temperatures. The mean annual temperature for the period was 54ºF. The maximum temperature was 102ºF, occurring in July 2012, while the minimum temperature was -3ºF, occurring in December 2011. Figure 4 presents the annual wind rose for the period while Figure 5 exhibits the four seasonal roses. Note the different wind direction ring scales among the roses. The annual wind rose shows that wind flows were bi-directional along the Sevier Valley axis, with predominant winds from the north, north-northeast, south-southwest, and southwest. The same pattern is observed in the seasonal wind roses, with the warmer seasons showing relatively stronger southwesterly component winds and higher wind speeds. These roses also reflect the high southwest wind events common to the Wasatch Front region.

Table 33 Temperature Summary for the Sevier Playa Meteorological Station

Temperature (°F) Period Average Maximum Minimum December 2011 24 63 -3 January 2012 30 59 4 February 2012 34 62 9 March 2012 47 76 18 April 2012 54 90 22 May 2012 65 93 34 June 2012 76 100 39 July 2012 80 102 55 August 2012 79 99 58 September 2012 68 93 43 October 2012 53 84 22 November 2012 42 70 14 Period 54 102 -3

53 Sevier Playa Potash Project Resource Report: Air Quality and Climate

6.5 Climate Change

The primary natural and anthropogenic greenhouse gases (GHGs) in the Earth's atmosphere are water vapor, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and fluorinated gases. GHGs allow heat from the sun to pass though the upper atmosphere, warm the earth, and block some of the heat radiated from the earth back into space. As GHG concentrations increase in the atmosphere, the amount of heat that escapes back into space decreases. Many GHGs are naturally occurring in the environment; however, human activity has contributed to increased concentrations of these gases in the atmosphere.

CO2 is emitted from combusting fossil fuels (for example, oil, natural gas, or coal), solid waste, trees, and wood products. It can also be produced in chemical reactions (for example, during manufacture of cement). CH4 is emitted from livestock and other agricultural operations, as well as the decay of organic matter in municipal solid waste landfills. CH4 emissions also occur when combusting fuel and during the production and transport of coal, natural gas, and oil. N2O is emitted during agricultural and industrial operations, as well as during combustion of fossil fuels and solid wastes. Fluorinated gases are powerful GHGs emitted in relatively small amounts from a variety of industrial processes, and are often used as substitutes for ozone-depleting substances. These fluorinated gases include hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF6), and nitrogen trifluoride (NF3).

All of the GHGs can be classified in terms of their global warming potential (GWP) relative to CO2 over a 100-year period, termed CO2 equivalent (CO2e). The GWP of a GHG is calculated by multiplying the emissions by a GWP factor. These factors can change slightly from year to year, as more research is performed. Table 34 lists the GWP factors used by EPA in their Inventory of U.S. Greenhouse Gases and Sinks, 1990 to 2016 (EPA 2018f). This report uses the GWP values from the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4), per the United Nations Framework Convention on Climate Change (UNFCCC) reporting requirements. The GWP was developed to allow comparisons of the effects of different GHGs on global warming. Specifically, it is a measure of how much energy the emissions of one ton of a gas would absorb over a given period, relative to the emissions of one ton of CO2. The GWP was introduced in the IPCC First Assessment Report, where it was also used to illustrate the difficulties in comparing components with differing physical properties using a single metric. The 100-year GWP (GWP100) was adopted by the UNFCCC and its Kyoto Protocol and is now used widely as the default metric. It is only one of several possible emission metrics and time horizons (IPCC 2014).

The choice of emission metric and time horizon depends on type of application and policy context; hence, no single metric is optimal for all policy goals. All metrics have shortcomings, and choices contain value judgments, such as the climate effect considered and the weighting of effects over time (which explicitly or implicitly discounts effects over time), the climate policy goal, and the degree to which metrics incorporate economic or only physical considerations. There are substantial uncertainties related to metrics, and the magnitudes of the uncertainties differ across metric type and time horizon. In general, the uncertainty increases for metrics along the cause–effect chain from emission to effects (IPCC 2014). Proposals have been made for the UNFCCC to adopt a dual-term GHG accounting standard; using the 20- year GWP (GWP20) alongside the accepted GWP100. The GWP100 method was used for the Project because the vast majority of GHG emissions would be CO2 from engine exhaust and the 100 year GWP is more appropriate for CO2 than other time horizons. In addition, using the 100 GWP method allows for direct comparison with national and global emissions.

54

Sevier Playa Potash Project Resource Report: Air Quality and Climate

THIS PAGE INTENTIONALLY LEFT BLANK

56

(A) Winter (Dec 2011 to Feb 2012) (B) Spring (Mar to May 2012)

NORTH NORTH

15% 25%

12% 20%

9% 15%

6% 10%

3% 5%

WEST EAST WEST EAST

SOUTH SOUTH

(C) Summer (Jun to Aug 2012) (D) Fall (Sep to Nov 2012) NORTH NORTH

20% 20%

16% 16%

12% 12%

8% 8%

4% 4%

WEST EAST WEST EAST

SOUTH SOUTH

See Figure 4 for wind speed scale units.

Sevier Playa Potash Project Resource Report: Air Quality and Climate

THIS PAGE INTENTIONALLY LEFT BLANK

58 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 34 100-Year AR4 Global Warming Potential

Greenhouse Gas GWP Factor

CO2 1

CH4 25

N2O 298 HCFCs 124 to 14,800 CFCs 7,390 to 12,200

SF6 22,800

NF3 17,200

The EPA annually tracks GHG emissions in the United States by source sector (for example, industrial, land use, electricity generation, etc.), fuel source (for example, coal, natural gas, geothermal, petroleum, etc.), and economic sector (for example, residential, transportation, commercial, agriculture, etc.) in terms of CO2e. These data are presented in EPA’s report Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990 to 2016 (EPA 2018f). Table 35 catalogs GHG CO2e in million metric tons (mmt) (1 metric ton equals 1.1023 tons or 2,204.6 pounds) by broad economic sectors for the years 2005, 2010, and 2016, while Table 36 lists total U.S. emissions for these same three years by specific GHG and source type, focusing on the largest sources/sinks. Note that the negative value for the “Land Uses and Forestry” category denotes a sink for CO2e rather than a source, reducing global emissions somewhat.

Table 35 U.S. GHG Emissions by Economic Sector

Economic Sector 2005 (mmt CO2e) 2010 (mmt CO2e) 2016 (mmt CO2e) Electric Power Industry 2,439.9 2,296.7 1,846.1 Transportation 1,974.9 1,800.3 1,854.0 Industry 1,505.8 1,411.1 1,405.5 Agriculture 568.5 598.4 611.8 Commercial 402.6 414.0 415.2 Residential 370.4 355.8 332.1 U.S. Territories 58.1 46.6 46.6 Total Emissions 7,320.3 6,922.9 6,511.3 Land Uses and Forestry (Sink) (731.1) (716.9) (716.8) Net Emissions (Sources and Sinks) 6,589.1 6,206.0 5,794.5 Source: Table 2-10 from Main Report Tables file (EPA 2018d)

Table 36 U.S. GHG Emissions and Sinks

2005 2010 2016 Gas/Source (mmt CO2e) (mmt CO2e) (mmt CO2e)

CO2 Fossil Fuel Combustion 5,746.9 5,359.3 4,966.0 Non-Energy Use of Fuels 138.9 114.2 112.2

59 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 36 U.S. GHG Emissions and Sinks

2005 2010 2016 Gas/Source (mmt CO2e) (mmt CO2e) (mmt CO2e) Iron/Steel & Metallurgical Coke Production 68.2 56.9 42.3 Natural Gas Systems 22.5 22.7 25.5 Cement Production 46.2 31.4 39.4

Total CO2 6,132.0 5,701.1 5,310.9

CH4 Natural Gas Systems 22.5 22.7 25.5 Enteric Fermentation 168.9 171.3 170.1 Landfills 132.7 124.8 107.7 Coal Mining 64.1 82.3 53.8 Manure Management 56.3 62.1 67.7

Total CH4 688.6 693.6 657.4

N2O Agricultural Soil Management 253.5 274.3 283.6 Stationary Combustion 7.8 7.8 7.3 Manure Management 56.3 62.1 67.7 Mobile Combustion 9.4 6.2 3.6 Nitric Acid Production 11.3 11.5 10.2

Total N2O 357.8 366.8 369.5 Fluorinated Gases Substitution of Ozone Depleting Substances 102.7 139.8 159.1 HCFC-22 Production 20.0 8.0 2.8 Electrical Transmission and Distribution 8.3 5.9 4.3 Total Fluorinated Gases 142.0 161.5 173.4 Totals Total Gross Emissions 7,320.3 6,922.9 6,511.3 Land Use, Land-Use Change, and Forestry (Sink) (731.1) (716.9) (716.8) Total Net Emissions (Sources - Sinks) 6,589.1 6,206.0 5,794.5 Source: Table 2-1 from Main Report Tables file (EPA 2018d).

Secondary GHGs contribute indirectly to atmospheric warming. These gases affect absorption of terrestrial radiation by influencing the formation and destruction of tropospheric and stratospheric ozone, or in the case of SO2, the absorptive characteristics of the atmosphere. Some of these gases may also react with other chemical compounds in the atmosphere to form compounds that are primary GHGs. Table 36 presents SO2 emissions from certain source types. Levels of SO2 emissions have decreased since 2005, in part because of reductions in electricity generation, but primarily because of increased consumption of low sulfur coal from surface mines in the western states.

60 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 37 U.S. SO2 Emissions

Gas/Source 2005 (mmt) 2010 (mmt) 2016 (mmt) Energy (combustion, etc.) 11.541 6.120 1.790 Industrial Processes 0.831 0.617 0.496 Mobile Fuel Combustion 0.180 0.117 0.093 Oil and Gas Activities 0.619 0.144 0.044

Total SO2 13.196 7.014 2.457 Source: Table 2-15 from Main Report Tables file for EPA (2018d),

On a state-level scale, in 2005 the total CO2e emissions were estimated to be 69 mmt (76 million tons) for the State of Utah (Center for Climatic Strategies 2007). According to U.S Energy Information Administration (EIA) in Energy-Related Carbon Dioxide Emissions by State, 2000-2015 (EIA 2018), energy-related CO2 emissions for the State of Utah for the years 2005, 2010 and 2015 were estimated to be 67.1, 64.0, and 63.2 mmt (74, 70.5 and 69.6 million tons), respectively.

NAAQS do not exist for GHGs. In its Endangerment and Cause or Contribute Findings for Greenhouse Gases under Section 202(a) of the CAA, the EPA determined that GHGs are air pollutants subject to regulation under the CAA. The status of GHGs as pollutants is based on the added long-term effects they have on climate because of their increased concentrations in the earth’s atmosphere. Ongoing scientific research has identified that anthropogenic GHG emissions influence the global climate.

7.0 Analysis of Effects

This section describes the potential direct, indirect, and cumulative effects on air quality and climate that could be caused by the construction, operation, maintenance, and decommissioning of the Project.

7.1 Applicant Committed Design Features

Some of the applicant committed design features introduced in Section 2.1 and listed in full in Appendix K in the EIS were developed to avoid, minimize, or mitigate potential effects to air quality. In Appendix K in the EIS, these design features are organized according to the primary resource that would be protected and are not repeated for other resources that would also benefit from their implementation. Some of the design features apply to the entire Project, while others only apply to certain parts of the Project. Additional details can be found in Appendix K in the EIS.

In addition to the applicant committed design features, a Fugitive Dust Control Plan (CPM 2019f) has been developed to support avoidance, minimization, and mitigation of effects to air quality. This plan contains applicant committed design features that are in addition to the design features in Appendix K in the EIS.

CPM would implement the applicant committed design features regardless of which action alternative or combination of alternatives may be selected. In analyzing the potential effects of the Project on air quality, it was assumed that all of the design features would be implemented and would be effective. Thus, the effects described in the remainder of this section are those that would occur despite integration of these design features into the Project. The design features developed specifically to avoid, minimize, or mitigate effects to air quality are listed in Table 38. In addition, specific design features listed in the Modeling Report (Ramboll 2019a) were incorporated into the emission inventory calculations (Section

61 Sevier Playa Potash Project Resource Report: Air Quality and Climate

5.2) and modeling analyses. CPM has committed to implementing these features as part of the Project. These design features would include:

• Tier 3, Tier 4, or Tier 4 (final) engines for heavy-duty mobile equipment

• Tier 4 engines for generators

• Tier 2 engines for personnel transport vehicles

• Watering, chemical suppressants, or brine application on active areas or unpaved roads, as applicable

• Partial enclosures, complete enclosures, or baghouses for material transfer and processing activities

7.2 Direct and Indirect Effects

The following sections describe the direct and indirect effects of the proposed action, action alternatives, and no action alternative on air quality and climate.

7.2.1 Proposed Action

Specific topics addressed in this section include fugitive dust emissions, other emissions, NAAQS, PSD increments, effects to AQRVs in Class 1 and Class II areas of interest, GHG emissions, and climate change.

7.2.1.1 Fugitive Dust Emissions

If the Project were implemented, fugitive dust emissions would increase in the analysis area over what currently exists on both a daily and annual basis. Fugitive dust increases would occur in all three phases of the Project from 2019 through 2053.

Fugitive dust would be emitted from heavy equipment moving and working on the playa, BMUs, canals, trenches, and berms; light-duty and heavy-duty vehicle movement on paved and unpaved roads; material transfer to piles, pile management, and road maintenance; and wind-blown dust from exposed areas on the playa and from storage piles. Fugitive dust would consist of the criteria air pollutants PM10 and PM2.5. The maximum annual increase would be 528 tons of PM10 and 67 tons of PM2.5 (Table 13), while the maximum daily increase would be 3,754 pounds of PM10 and 582 pounds of PM2.5 (Table 14). The majority of the fugitive dust would be generated by vehicle movement on roads. Emission estimates for fugitive dust include controls such as watering, chemical suppressants, or brine application, controlling the majority of the fugitive dust sources at the 70 to 80 percent level. One exception would be paved roads that are public and are out of the control of CPM.

62 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 38 Applicant Committed Design Features, Air Quality

Applicability to the Project # * Not applicable within the playa boundary

1

1 Plan# Fugitive Dust Dust Fugitive Control Control Design and Engineering Construction Maintenance Appendix K EIS / Appendix Operation and

Measure Decommissioning 15 N/A CPM would meet all applicable federal, state, and local emission standards for air quality. ✔ ✔ ✔ ✔ CPM would develop and implement a Fugitive Dust Control Plan (CPM 2019f), to be approved by BLM, 16 N/A to minimize Project effects from fugitive dust. ✔ ✔ ✔ ✔ Dust control would be provided throughout construction, operation, maintenance, and decommissioning to protect soils from erosion and minimize fugitive dust from Project activities. Dust control methods 17 N/A would be specified in the Fugitive Dust Control Plan (CPM 2019f) and would be approved by the BLM ✔ ✔ ✔ prior to their implementation. Trucks hauling the finished product from the Processing Facility to the Rail Loadout Facility would 18 N/A minimize dust emissions by limiting vehicle speed or using dust control methods specified in the Fugitive ✔ Dust Control Plan (CPM 2019f). Earthen and other materials, which may become airborne, would be promptly removed from paved roads 19 N/A or handled as described in the Fugitive Dust Control Plan (CPM 2019f). ✔ ✔ ✔ 20 N/A No burning of debris, garbage, or other materials would be allowed. ✔ ✔ ✔ Dust emissions caused by truck loading and unloading would be minimized, as described in the Fugitive 21 N/A Dust Control Plan (CPM 2019f). The drop distance at material transfer points would be minimized to ✔ reduce dust generation as described in the Fugitive Dust Control Plan. Tailpipe emissions from diesel-powered equipment would be minimized through use of engines meeting 22 N/A Tier 2 standards or better. ✔ ✔ ✔ Minimize disturbed surface area by adhering to strict construction plans to limit maximum actively N/A 1 disturbed construction areas. ✔ ✔ ✔ Restrict vehicle travel to only established roads by using signage and training, except for activities where N/A 2 overland travel has been approved. ✔ ✔ ✔ Employ a Dust Control Supervisor who would be responsible for monitoring visible dust and control N/A 3 measures. ✔ ✔ ✔

63 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 38 Applicant Committed Design Features, Air Quality

Applicability to the Project # * Not applicable within the playa boundary

1

1 Plan# Fugitive Dust Dust Fugitive Control Control Design and Engineering Construction Maintenance Appendix K EIS / Appendix Operation and

Measure Decommissioning Speed limits for Project traffic would be set at a maximum of 30 mph on-road and 15 mph off-road to reduce the generation of fugitive dust and minimize the risk for collisions between Project traffic and livestock or wildlife. This design feature would apply on all unpaved roads authorized for use by Project traffic, including unpaved Millard County Class B roads. This design feature would not apply on paved roads, where Project traffic would follow posted speed limits. The Adaptive Wildlife Management Plan 14 4 (CPM 2019b) (Design Feature #95) would include monitoring and adaptive measures to adjust speed ✔ ✔ ✔ limits to changes in road conditions or use, or for corrective actions (for example, fencing, or signage) in the event that Project traffic causes an unacceptable increase in collisions between Project vehicles and wildlife or livestock. In the event that vehicle traffic causes visible dust emissions, equipment operators would be instructed to reduce speed to a level that does not cause excessive dust in accordance with the Fugitive Dust Control Plan (CPM 2019f) (Design Feature #16).

Stabilize on-playa disturbed surfaces with water, commercial-grade MgCl2, other agency-approved N/A 5 commercially-available dust suppressant or soil stabilizer, and/or brine, to minimize visible fugitive dust ✔ ✔ ✔ plumes.

Stabilize off-playa, on-road disturbed surfaces with water, commercial-grade MgCl2, or other agency- approved commercially-available dust suppressant or soil stabilizer to minimize visible fugitive dust N/A 6 plumes. Stabilize off-playa, off-road disturbed surfaces with water, to minimize visible fugitive dust ✔ ✔ ✔ plumes.

Stabilize Crystal Peak Road and Crystal Peak Spur Road with commercial-grade MgCl2, other agency- N/A 7 approved commercially-available dust suppressant or soil stabilizer, lime chips, and/or water. ✔ ✔ ✔ Construct berms with compacted, engineered fill so that the berms can withstand ongoing disturbance N/A 8 while minimizing fugitive dust generation. ✔ Except when loading/unloading material, restrict haul truck travel to Perimeter Road (including associated spurs, segments, and turnouts), approved engineered berms, Processing Facility haul roads, and Rail N/A 9 Loadout Facility Access Roads. This measure would be publicized through signage and presented in ✔ ✔ ✔ training.

64 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 38 Applicant Committed Design Features, Air Quality

Applicability to the Project # * Not applicable within the playa boundary

1

1 Plan# Fugitive Dust Dust Fugitive Control Control Design and Engineering Construction Maintenance Appendix K EIS / Appendix Operation and

Measure Decommissioning Cover trucks hauling product from the Production Ponds to the Processing Facility and between the N/A 10 Processing Facility and the Rail Loadout Facility. ✔ ✔ ✔ Provide dedicated transport for on-playa travel to take employees from a centralized parking area at the N/A 11 Processing Facility to the playa operational and construction areas. ✔ ✔ ✔ Utilize engineering controls such as shrouds on drop points and enclosed conveyors for the transfer of N/A 12 materials between the haul trucks and the railway containers at the Rail Loadout Facility. ✔ ✔ ✔ ✔ Apply track-out prevention measures or devices (e.g., track-out pads, grizzly plates) at key locations N/A 13 where unpaved roadways intersect with paved roadways. The measures would either be implemented on ✔ ✔ ✔ the unpaved roadways themselves or at adjoining pull-outs. * Not applicable within the playa boundary. 1 During operations, maintenance, and decommissioning, some design features would only apply to the initiation of new activities. N/A: These design features are not replicated in the Fugitive Dust Control Plan or are in addition to the applicant committed design features from Appendix K in the EIS.

65 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Fugitive dust would be transported by the wind away from the Project sources into the analysis area. In general, the highest increases in concentrations of PM10 and PM2.5 would be at or near the ambient air boundary, as well as along the Crystal Peak Road or Crystal Peak Spur Road. PM10 and PM2.5 concentrations would decrease relatively rapidly as the plume disperses and settles downwind and away from the Project ambient air boundary and Project dust-generating sources. The plume concentrations would dissipate to near background levels within about 3 km (2 miles) of the ambient air boundary, Crystal Peak Road, or Crystal Peak Spur Road. Section 7.2.1.3 contains discussions related to NAAQS for PM.

CPM would implement a FDCP (CPM 2019f) that specifies applicant committed design features that would minimize dust generation (Table 38). The FDCP would cover every phase of the Project and the dust generating activities that occur in each phase. CPM would employ a Dust Control Supervisor who would be responsible for monitoring visible dust and ensuring that controls are being implemented. If high wind conditions occur, alert measures would be implemented that involve the inspection of all controls. High wind conditions are defined in the FDCP as any one of the following:

• An hourly wind speed measured at the Sevier Playa meteorological station has exceeded 35 mph in the last 12 hours

• An instantaneous gust measured at the Sevier Playa meteorological station has exceeded 45 mph in the last 12 hours

• A high wind warning or high wind advisory is issued by the NWS for Southwest Utah.

In addition, all fugitive dust generating activities would cease until notified by the Dust Control Supervisor if the hourly average wind as measured by the Sevier Playa meteorological station:

• Exceeds 35 mph for three consecutive hours; or

• Exceeds 40 mph for one hour.

The design features in the FDCP would help to minimize fugitive dust emissions from the Project. The specified controls for the sources and the FDCP itself would be part of the Approval Order air permit from UDAQ and would be enforceable through that permit.

7.2.1.2 Other Emissions

If the Project were implemented, the analysis area would experience an increase in air pollutants including NOX, CO, VOCs, SO2, as well as process and tailpipe emissions of PM10 and PM2.5. Air pollution increases would occur in all three phases of the Project from 2019 through 2053.

These six air pollutants would be emitted from dryers and other stationary equipment as well as mobile light-duty and heavy-duty vehicles. For NOX, the maximum annual increase would be 157 tons while the maximum daily increase would be 997 pounds. For CO, the maximum annual increase would be 349 tons while the maximum daily increase would be 2,237 pounds. For VOCs, the maximum annual increase would be 19 tons while the maximum daily increase would be 120 pounds. For SO2, the maximum annual increase would be 0.4 tons while the maximum daily increase would be 3 pounds. For PM10 that is not fugitive dust, the maximum annual increase would be 59 tons and the maximum daily would be 908 pounds. For PM2.5 that is not fugitive dust, the maximum annual increase would be 40 tons and the maximum daily would be 310 pounds (Table 13 and Table 14).

66 Sevier Playa Potash Project Resource Report: Air Quality and Climate

As with fugitive dust, the air pollutant plumes would be transported away from Project sources into the analysis area. In general, the highest concentrations of pollutants would be at or near the ambient air boundary, as well as along the Crystal Peak Road or Crystal Peak Spur Road. The pollutant concentrations in the plume would decrease relatively rapidly as plumes flow downwind and away from the ambient air boundary and Project sources. The plume concentrations would dissipate to near background levels within about 3 km (2 miles) of the ambient air boundary, Crystal Peak Road, or Crystal Peak Spur Road. Section 7.2.1.3 contains discussions related to NAAQS.

7.2.1.3 National Ambient Air Quality Standards

If the Project were implemented, the air pollutants emitted would affect the analysis area to differing degrees, as presented in the Modeling Report. To assess the level of these effects, the modeled concentrations were compared against the applicable NAAQS for each pollutant and averaging period (Table 39). The Project-only concentration represents the maximum modeled effect over all of the receptors for the respective rank. The background concentration represents the existing air quality for the analysis area (Section 5.5). The total concentration is the sum of the modeled Project-only concentrations and the existing background concentration. This sum is the value that is compared against the NAAQS when determining if the Project would comply with the applicable standard. Each pollutant is discussed in the subsections below.

7.2.1.3.1 Carbon Monoxide

The modeled Project-only concentrations for both 1-hour and 8-hour averaging periods for CO represent the highest of the second-high concentrations for all receptors. The modeled concentrations would be near or below the existing background air quality and the total concentration would be well below the NAAQS (Table 39). If implemented, the effects of Project CO emissions on the analysis area would be relatively minimal.

7.2.1.3.2 Nitrogen Dioxide

3 The modeled Project-only concentration of 323.4 μg/m for the 1-hour NO2 averaging period represents the highest of the 8th high concentrations for all receptors. This concentration is much greater than the background air quality and is above the NAAQS by itself. The background concentration shown in Table 39 is the representative concentration for the season and hour during which the highest 8th-high concentration occurred (Section 5.5.4 and Table 28). The total concentration is 347.3 μg/m3 and is above the NAAQS. For the maximum season and hour, one of the primary contributors to the Project-only concentration would be the gravel pit sources. Excluding the gravel pit sources, the 1-hour NO2 highest 8th high concentration is 293.3 μg/m3 for total concentration of 316.4 μg/m3 when the corresponding seasonal hour background concentration is included. Again, both the modeled Project-only and total concentrations are above the NAAQS.

Figure 6 depicts the areal coverage of the total 1-hour NO2 concentrations and how the concentrations are distributed across the analysis area. The maximum total concentration of 347.3 μg/m3 is located along the southern ambient air boundary by the gravel pits and Processing Facility. The maximum modeled concentration of 316.4 μg/m3 (not shown) that did not include gravel pits is also located on the southern ambient air boundary. The sources contributing to the maximum concentrations are the tailpipe emissions from the heavy-duty equipment working in the gravel pits and constructing the Processing Facility. Other maximum concentrations exceeding the NAAQS are shown by the Rail Loadout Facility and by the Black Rock Communication Tower. These are also caused by tailpipe emissions from heavy-duty equipment involved in the construction of these facilities. For all of these maximum areas, the concentration drops

67 Sevier Playa Potash Project Resource Report: Air Quality and Climate below the NAAQS within about 500 meters (1,640 feet). The concentrations decrease to levels that are indistinguishable from background within about 3 km (2 miles) from the boundary.

Table 39 Comparison of Maximum Project Concentrations to the NAAQS

Project- Only Background Total (2) (3) (4) Averaging Model Conc. Conc. Conc. NAAQS % of Exceeds Pollutant Period Rank (1) (µg/m3) (µg/m3) (µg/m3) (µg/m3) NAAQS NAAQS? 1-hour 2nd 3,431 3,434.8 6,866 40,000 17.2 No CO 8-hour 2nd 482 2,747.9 3,230 10,000 32.3 No 1-hour 8th 323.4 23.9(5) 347.3 188 184.7 Yes NO2 Annual 1st 23.8 3.8 27.6 100 27.6 No (6) th (5) NO2 1-hour 8 293.3 23.1 316.4 188 168.3 Yes (7) nd PM10 24-hour 2 51.2 97.4 148.6 150 99.1 No (8) nd PM10 24-hour 2 96.9 16.4 113.3 150 75.5 No (9) nd PM10 24-hour 2 96.9 97.4 194.3 150 129.4 Yes th (10) 24-hour 8 15.3 11.8 27.1 35 77.4 No PM2.5 Annual 1st 6.9 4.1 11.0 12 91.7 No 1-hour 4th 3.4 18 21.4 196 10.9 No 3-hour 2nd 1.4 12.8 14.2 1,300 1.1 No SO2 24-hour (11) 2nd 0.3 5.8 6.1 365 0.1 No Annual (11) 1st 0.04 1.5 1.5 80 1.9 No (1) Rank of the modeled concentration used when modeling for the NAAQS. (2) Maximum modeled Project-only concentration over all receptors for the respective model rank (3) Background concentration represents the existing air quality for the analysis area. See Section 5.5. (4) Total concentration is the Project-only concentration plus background concentration, and is compared to the NAAQS. (5) This concentration is the calculated NO2 seasonal-hour background concentration for the same season and hour for which the listed modeled concentration occurred. See Table 28 and Section 5.5.4 for the development of the seasonal hour concentrations. (6) Project-only model results without the gravel pit sources. (7) Highest second-high total concentration model results when considering the modeled Project-only 24-hour concentration plus the respective 24-hour seasonal background concentration (spring) (see Table 27). See Section 7.2.1.3.3 for further details. (8) Project-only highest second-high 24-hour concentration for the model year, which occurred in the winter season. The background concentration shown is the winter background concentration. See Section 7.2.1.3.3 for further details. (9) Project-only highest second-high 24-hour concentration for the model year summed with the second highest 24-hour background concentration for the monitor year. See Section 7.2.1.3.3 for further details. (10) Project-only concentration for PM2.5 includes both modeled primary concentration plus secondary PM2.5 concentration. See Section 7.2.1.3.4. (11) The primary 24-hour and annual SO2 NAAQS were revoked in 2010. Comparisons are listed here for informational purposes.

68 Black Rock 4,335,000 Communication Tower

4,330,000

4,325,000

4,320,000

4,315,000

4,310,000

4,305,000

400

4,300,000 350

4,295,000

UTM Northing (Zone 12, NAD83, meters) 300

4,290,000 250 Maximum: 347.32 µg/m³

4,285,000 200

Background: Variable 150 4,280,000 NAAQS: 188 g/m3 Outer Limit of NAAQS Exceedance: Ambient Air Boundary: 100 4,275,000 BMU Outline: ( g/m3)

305,000 310,000 315,000 320,000 325,000 330,000 335,000 340,000 345,000 350,000 UTM Easting (Zone 12, NAD83, meters)

Source: Modified Figure A4 from Ramboll (2019a) Sevier Playa Potash Project Resource Report: Air Quality and Climate

THIS PAGE INTENTIONALLY LEFT BLANK

70 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Modeled exceedances do not necessarily translate to actual monitored exceedances because of the conservative nature of the model and the modeling analysis. As discussed in Section 5.3.8, air dispersion models are designed to be conservative to be protective of human health and the environment. AERMOD can predict concentrations 2 to 10 times higher than monitored concentrations, if not greater (EPA 2017e). In addition, the analysis for 1-hour NO2 employed the Project’s highest daily emissions of 997 lbs. These emissions were apportioned to the gravel pits and the Processing Facility construction areas, all in close proximity to each other. The chances that these activities would occur at the modeled density at the same time as a poor dispersion hour are relatively low. Thus, while the total 1-hour NO2 modeled concentrations are above the NAAQS, this is a conservative estimate of the maximum potential effects. In addition, as the worst-case emissions day was modeled, days with lower emissions would generally have lower concentrations. If the Project were implemented, the effects from 1-hour NO2 emissions would be relatively localized to the activities, and decrease to levels that are indistinguishable from background within about 3 km (2 miles) of the ambient air boundary. The applicant committed design features listed in Table 38 would be used as applicable to minimize emissions from Project sources.

The modeled Project-only concentration for annual NO2 represents the maximum concentration over all receptors. This concentration is higher than the background air quality. The total concentration is below the NAAQS (Table 39). If implemented, the effects of the Project’s annual NO2 emissions on the analysis area would be relatively minimal.

7.2.1.3.3 PM10

The modeled Project-only PM10 concentrations for the 24-hour averaging period were assessed with three different methodologies. These methods involve various ways of combining modeled concentrations with background concentrations to obtain total concentrations.

The first method summed the modeled 24-hour PM10 concentrations with the respective seasonal background concentration (Table 27) and then from this sum the second highest total 24-hour concentration was selected (Table 39). Using this method, the modeled Project-only concentration is 51.2 μg/m3 which occurs in the spring, the spring seasonal background concentration is 97.4 μg/m3 (Table 27), and the total concentration is 148.6 μg/m3 (Table 39). This total concentration is slightly below the NAAQS.

The second method sums the Project-only modeled highest second-high 24-hour concentration for the model year with the respective seasonal background value. For this method, the modeled Project-only highest second-high concentration is 96.9 μg/m3 which occurs in the winter, the winter seasonal background concentration is 16.4 μg/m3 (Table 27), and the total concentration is 113.3 μg/m3 (Table 39). This total concentration is below the NAAQS.

The third method sums the Project-only modeled highest second-high 24-hour concentration for the model year with the second highest background concentration for the entire monitoring year (Table 9). Using this method, the modeled Project-only highest second-high concentration is 96.9 μg/m3, the second highest background concentration is 97.4 μg/m3, and the total concentration is 194.3 μg/m3 (Table 39). This total concentration is above the NAAQS.

The first and second methods consider the relatively large fluctuations of PM10 background concentrations that occur with the seasons, similar to the 1-hour NO2 analysis, only adding the respective seasonal background to the modeled concentrations. The third method employs the highest second-high modeled concentration, ignoring the season the modeled impact occurs, and adds it to the second highest monitored background concentration to obtain the total concentration.

71 Sevier Playa Potash Project Resource Report: Air Quality and Climate

In all three methods, the Project maximum daily emissions and source placement are the same. The first two methods provide a more realistic, yet still conservative, prediction of the total concentrations (Project plus background) of PM10. The third method provides a worst-case analysis at both the modeling and background levels. The chances that an unusually high background concentration would occur the same day as the daily maximum emissions and modeled source emissions density with poor dispersion conditions are relatively low.

Figure 7 depicts the areal extent of the total 24-hour PM10 concentrations using the first method. The maximum concentration is located at the Rail Loadout Facility east of the Sevier Playa. Relatively higher concentrations are seen along the southern ambient air boundaries, as well as along Crystal Peak Road and Crystal Peak Spur road leading to the Rail Loadout Facility. The concentrations decrease rapidly to levels that are indistinguishable from background within about 3 km (2 miles) from the ambient air boundary or roads. If the Project were implemented, the effects on the analysis area would be restricted to within about 3 km (2 miles) of the ambient boundary, and decrease to minimal levels further out. To further illustrate the anticipated effects, Figure 8 displays a ring that is 30 km from the Project boundary. The 24-hour highest second-high Project-only concentrations for receptors along that ring are less than 3 0.45 μg/m (0.31% of the 24-hour PM10 NAAQS). This figure shows that during either a typical day, or even on a relatively windy day, the effects of the Project emissions would stay within 30 km of the Project.

7.2.1.3.4 PM2.5

The Project-only concentrations for PM2.5 (Table 39) include both the direct emissions that were entered into AERMOD and an estimate of secondary PM2.5 concentrations calculated separately from the model. Secondary PM2.5 can form from NOX and SO2 emissions, which are called “precursors” in this context. AERMOD does not contain chemistry algorithms required to model this process and as a result, the secondary PM2.5 emissions have to be estimated outside of the model.

Ramboll (2019a) estimated the amount of secondary PM2.5 that would be generated from the Project’s NOX and SO2 emissions following EPA’s memorandum Guidance on the Development of Modeled Emission Rates for Precursors (MERPs) as a Tier 1 Demonstration Tool for Ozone and PM2.5 Under the PSD Permitting Program (MERP Guidance) (EPA 2016b). The MERP Guidance provides numerous generic modeling studies performed by EPA for the entire nation. The most representative of these modeling studies was selected. The ratio of the Project precursor emission to the selected MERP study precursor emissions was calculated. This ratio was then multiplied by the PM2.5 SIL concentration to obtain an estimate of the Project secondary PM2.5 concentration.

This produced the following results for the Project:

3 • Secondary 24-hour PM2.5 concentration = 0.18 μg/m

3 • Secondary annual PM2.5 concentration = 0.010 μg/m

These two values were added to the respective direct PM2.5 concentrations from AERMOD for the final modeled Project-only concentration in Table 39. The modeled Project-only concentration of 15.3 μg/m3 th for 24-hour PM2.5 represents the highest of the 8 high concentrations for all receptors. This concentration is slightly higher than the background air quality. The total concentration of 27.1 μg/m3 is below the NAAQS (Table 39). The modeled Project-only concentration for annual PM2.5 represents the maximum concentration over all receptors. This concentration of 6.9 μg/m3 is slightly higher than the background air quality. The total concentration of 11.0 μg/m3 is close to, but below, the NAAQS (Table 39).

72 4,335,000

4,330,000

4,325,000

4,320,000

4,315,000

4,310,000

4,305,000

4,300,000 140

4,295,000 130 UTM Northing (Zone 12, NAD83, meters)

4,290,000 120 Maximum: 148.63 µg/m³ 4,285,000

110 4,280,000 Background: 97.4 µg/m3 NAAQS: 150 µg/m3 NAAQS Exceedance: None Ambient Air Boundary: 100 4,275,000 BMU Outline: (µg/m3)

305,000 310,000 315,000 320,000 325,000 330,000 335,000 340,000 345,000 350,000 UTM Easting (Zone 12, NAD83, meters)

Source: Modified Figure A5 from Ramboll (2019a) Sevier Playa Potash Project Resource Report: Air Quality and Climate

THIS PAGE INTENTIONALLY LEFT BLANK

74 Ambient Air Boundary

30 km from Boundary Great Project concentrations less than 0.31 % 3 Salt of 24-Hour PM10 NAAQS (0.45 ug/m ) Lake

Great Salt Salt Lake City ¨¦§80 Lake

TOOELE COUNTY Utah Lake UTAH COUNTY

JUAB COUNTY Nephi Ii ¤£89

15 ¤£6 ¨¦§ MILLARD COUNTY Delta

Scipio £50 SANPETE ¤ COUNTY ¤£50 Fillmore Salina

Richfield SEVIER COUNTY 70 BEAVER COUNTY ¨¦§ 0 100 Milford km

Source: Modified Figure A18 from Ramboll (2019a) Sevier Playa Potash Project Resource Report: Air Quality and Climate

THIS PAGE INTENTIONALLY LEFT BLANK

76 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Figure 9 depicts the areal extent of the total 24-hour PM2.5 concentrations and how concentrations are distributed across the analysis area. Similar to PM10, the maximum concentration is located at the Rail Loadout Facility east of the Sevier Playa. Relatively higher concentrations are seen along the southern ambient air boundaries, as well as along Crystal Peak Road and Crystal Peak Spur road leading to the Rail Loadout Facility. The concentrations decrease rapidly to levels that are indistinguishable from background within about 3 km (2 miles) of the ambient air boundary or roads. The annual PM2.5 concentration areal distribution (not shown) has a similar pattern, with the maximum occurring at the Rail Loadout Facility and the relatively higher concentrations along the southern boundary and along the road leading to the Rail Loadout Facility.

If the Project were implemented, the effects on the analysis area for both 24-hour and annual PM2.5 would be restricted to within about 3 km (2 miles) of the ambient boundary, and decrease to minimal levels further out.

7.2.1.3.5 Sulfur Dioxide

th The modeled Project-only concentration for 1-hour SO2 represents the highest of the 4 high concentrations for all receptors. The modeled Project-only concentration for the 3-hour and 24-hour averaging periods represents the highest of the second-high concentrations for all receptors. The modeled Project-only concentration for the annual averaging period represents the maximum concentration over all receptors. All of these concentrations are well below the background concentrations and all total concentrations are well below the NAAQS (Table 39). Note that the 24-hour and annual NAAQS for SO2 were revoked in 2010 (EPA 2010a) and are listed here for informational purposes. If the Project were implemented, the effects of the SO2 emissions on the analysis area would be minimal.

7.2.1.3.6 Ozone

Ozone cannot be modeled with AERMOD, as the model does not contain the necessary algorithms. Using the screening methods from the MERP Guidance, it was determined that the total Project NOX and VOC emissions would be below the amount necessary to create ozone concentrations above 1 ppb over an 8- hour period. Thus, if the Project were implemented, the effects of O3 created from the VOCs and NOX emissions would be below 1 ppb for an 8-hour average and would have minimal effects on the analysis area.

7.2.1.4 PSD Increments

Ramboll (2019a) compared Project-only modeled concentrations against the PSD Class II increments for all applicable pollutants and averaging times. Ramboll also calculated how far from the ambient air boundary the Project concentrations would drop below increment levels (Table 40). Note that the comparison to increments was done only for informational purposes at the request of the EPA and does not represent a formal PSD increment analysis. Formal increment analyses are only performed for a PSD source and would involve the modeling of both increment consuming and expanding sources. As proposed, the Project would be a minor source and formal increment analyses are not required (see Utah Division of Air Quality Emission Impact Assessment Guidelines (UDAQ 2013). Overall, the tracking of increment consumption and expansion from minor sources is the responsibility of the state agency (UDAQ in this case), not the BLM.

77 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 40 Comparison of Project Concentrations with PSD Increments

Project-Only Modeled PSD Class II Maximum Averaging Model Concentration (2) Increment Distance to Pollutant Period Rank (1) (µg/m3) Location of Maximum (µg/m3) Increment (m) 600 m southeast of st NO2 Annual 1 23.8 Processing Facility near 25 --- one of the gravel pits 24-hour 2nd 96.9 30 50 PM10 Annual 1st 30.6 All PM maxima were 17 50 located near the Rail 24-hour 2nd 17.5 9 50 (3) Loadout Facility. PM2.5 Annual 1st 6.9 4 50 3-hour 2nd 1.4 300 m southwest of the 512 ---

nd Processing Facility near 24-hour 2 0.3 one of the gravel pits. 91 --- SO2 600 m southwest of the Annual 1st 0.04 Processing Facility near 20 --- one of the gravel pits. (1) Rank of the modeled concentration used when modeling for the increment. (2) Maximum modeled Project-only concentration over all receptors for the respective model rank (3) Project-only concentration for PM2.5 includes both modeled primary concentration plus secondary PM2.5 concentration. See Section 7.2.1.3.4.

The Project-only effects for 24-hour PM10, 24-hour PM2.5, 3-hour SO2, and 24-hour SO2 represent the highest of the second-high concentrations over all of the receptors. The Project-only concentrations for the annual averaging periods for NO2, PM10, and SO2 reflect the maximum concentration over all of the receptors. If the Project were implemented, the only pollutants that would exceed the increment in the analysis area would be PM10 and PM2.5 for the 24-hour and annual averaging periods. The concentrations would drop below the increment level within about 50 m (164 feet) from the maximum locations.

Ramboll (2019a) compared Project-only emissions against the PSD Class I and Class II increments for all applicable pollutants and averaging times at receptors located on the western edge of the Fishlake National Forest (Table 41). The modeled concentrations at the Fishlake National Forest would be well below both Class I and Class II increments for all pollutants and averaging times. If the Project were implemented, effects to the Fishlake National Forest would be minimal.

78 4,335,000

4,330,000

4,325,000

4,320,000

4,315,000

4,310,000

4,305,000

26

4,300,000 24

4,295,000

UTM Northing (Zone 12, NAD83, meters) 22

4,290,000 20

Maximum: 27.11 µg/m³

4,285,000 18

16 4,280,000 Background: 11.8 µg/m3 NAAQS: 35 µg/m3 NAAQS Exceedance: None Ambient Air Boundary: 14 4,275,000 BMU Outline: (µg/m3)

305,000 310,000 315,000 320,000 325,000 330,000 335,000 340,000 345,000 350,000 UTM Easting (Zone 12, NAD83, meters)

Source: Modified Figure A6 from Ramboll (2019a) Sevier Playa Potash Project Resource Report: Air Quality and Climate

THIS PAGE INTENTIONALLY LEFT BLANK

80 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 41 Comparison of Project Concentrations to PSD Increments on the Fishlake National Forest

Class II Class I Exceeds Averaging Model Project-Only Modeled Increment Increment Class I or II Pollutant Period Rank Concentration (µg/m3) (µg/m3) (µg/m3) Increment? st NO2 Annual 1 0.79 25 2.5 No 24-hour 2nd 0.15 30 8 No PM10 Annual 1st 0.02 17 4 No 24-hour 2nd 0.12 9 2 No PM2.5 Annual 1st 0.01 4 1 No 3-hour 2nd 0.03 512 25 No nd SO2 24-hour 2 0.003 91 5 No Annual 1st 0.0001 20 2 No

7.2.1.5 Effects to AQRVs in Class I and Class II Areas of Interest

Ramboll (2019a) performed a screening level analysis to address effects to the AQRVs in the six Class I areas and two Class II areas of interest in the general region (Table 3). The screening level methodology is prescribed by the FLMs in the Air Quality Related Values Work Group (FLAG) – Phase I Report (U. S. Forest Service et al. 2010). The screening technique compares the total emissions of PM10, NOX, and SO2 with the distance to the Class I or Class II area of interest in question. The relevant emissions total is the sum of the maximum 24-hour (daily) emissions for PM10, NOX, and SO2 converted to annual emissions in tons as if the maximum daily occurred for all 365 days. It is important to note that the maximum daily emission level for each pollutant was selected, even though these did not occur in the same year. The emissions total, Q, is divided by the distance to the Class I or Class II area of interest, D (in km). If the Q/D value is less or equal to 10, then the effect from the source’s emissions on that area is assumed to be negligible and no quantitative analysis for AQRVs is required. The results from the screening for the Project are presented in Table 42. All Q/D values for Class I areas are below 10. If the Project were implemented, the effects to AQRVs in the Class I areas would be negligible. All Q/D values for Class II areas of interest were above 10, and thus an additional analysis was performed to further assess the visibility effects on these two areas.

Table 42 AQRV Screening Analysis

Approximate Distance Annual AQRV Analysis from Playa Center, Emissions, Required? Area Name D (km) / (miles) Q (tpy) Q/D (Y/N) Class I Area Zion National Park 135 / 84 8 N Bryce Canyon National Park 144 / 89 7 N Capitol Reef National Park 149 / 93 7 N 1,033 Grand Canyon National Park 248 / 154 4 N Canyonlands National Park 248 / 154 4 N Arches National Park 285 / 177 4 N Class II Area of Interest Fishlake National Forest 56.7 / 35 1,033 18 Y

81 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 42 AQRV Screening Analysis

Approximate Distance Annual AQRV Analysis from Playa Center, Emissions, Required? Area Name D (km) / (miles) Q (tpy) Q/D (Y/N) Great Basin National Park 85.7 / 53 12 Y

7.2.1.5.1 Visibility Screening for the Class II Areas of Interest

Ramboll (2019a) performed a visibility screening level analysis to address effects to visibility in the two Class II areas of interest. The analysis was conducted in accordance with the Workbook for Plume Visual Impact Screening and Analysis (Visibility Workbook, EPA1992b). The plume visual impact screening model VISCREEN (Version 13190) was used to assess visibility impacts, per FLAG (U. S. Forest Service et al. 2010).

VISCREEN assesses whether a plume from a source is visible to the typical person against the sky or a terrain feature, such as a scenic vista. The criteria for a visible plume are based on two screening threshold values of ΔE at 2.0 and contrast at 0.05. If the model output values are above these screening values, then the plume would be visible. To make this assessment, annualized maximum 24-hour emissions of PM10, NOX, soot, and sulfate (SO4), as applicable, are entered into the model. The distance from the source to the area being analyzed is also entered. VISCREEN is then run with specific meteorological conditions of atmospheric stability and wind speed, depending on the screening level, known as Level 1 or 2.

The Level 1 meteorology assumes a very stable atmospheric condition, known as stability class F, with a very low wind speed of 1 m/s. This is very conservative and sets the atmosphere to be least dispersive. Atmospheric stability can be defined by Classes A to F, with Class A being the most dispersive (very unstable) to Class F being the least dispersive (very stable). Atmospheric stability Classes A, B and C are unstable, Class D is neutral, and Classes E and F are stable. Level 2 screening uses actual meteorology and sets the stability class and wind speed to values that represent the worst conditions at the one percent level by wind direction sector (for example, north, north-northwest, northwest, etc.). Other parameters, such as particle size, are set as default or adjusted, depending on the screening level.

Ramboll (2019a) first performed a Level 1 screening analysis with VISCREEN on the two Class II areas of interest. The emissions entered into VISCREEN were annualized maximum daily emissions of PM10 and NOX for the year 2025. This equates to 851 tpy of PM10 and 121 tpy of NOX. The Project would not emit soot or SO4. The distances to the near side and far side receptors of both Class II areas of interest were also entered. Figure 10a presents the receptor locations of the Class II areas of interest in relation to the Project. The results of the Level 1 screening analysis exceeded the screening criteria at both Great Basin National Park and the Fishlake National Forest.

As the Level 1 screening did not pass, Ramboll (2019a) performed Level 2 screening with VISCREEN, per the Visibility Workbook. Specific receptors along the boundary of both Class II areas of interest were placed based on wind direction (Figure 10b). Following the guidance in the Visibility Workbook, the worst case meteorological conditions for stability class and wind speed were calculated at the one percent level for each direction that affected the selected locations using the on-site meteorological data employed in the AERMOD modeling analysis. The worst one percent level stability class values were further adjusted to one class less stable if elevated terrain, defined as greater than 500 m (1,640 feet) above the elevation of the Project, exists between the Project and the Class II area of interest location.

82 Figure 10a. Near side and far side distances to Class II areas for Level 1 screening.

Figure 10b. Locations for Level 2 screening and surrounding terrain elevations.

Source: Modified Figure 3 and Figure 6 from Ramboll (2019a) Sevier Playa Potash Project Resource Report: Air Quality and Climate

THIS PAGE INTENTIONALLY LEFT BLANK

84 Sevier Playa Potash Project Resource Report: Air Quality and Climate

The stability class is also adjusted if the Class II area of interest receptor elevation is more than 500 m (1640 feet) above the Project. Table 43 lists the Level 2 meteorological screening analysis parameters for each location. Note that all locations except FL1 and FL2 meet the terrain adjustment criteria.

The particle size for the Level 2 runs was adjusted from the default size of 2 microns in diameter to 5 microns in diameter, given that the majority of the particulate matter is from mechanically-generated fugitive dust. The type of dust is primarily comprised of large-sized particles, i.e., greater than 2.5 microns. All other default parameters were used, and the same PM10 and NOX emissions from the Level 1 analysis were used.

Table 44 presents the Level 2 visibility screening results for the seven locations. VISCREEN models the potential effects of a Project to an observer inside an area in question, in this case, the Great Basin National Park and Fishlake National Forest. All locations passed the visibility screening criteria inside Great Basin National Park and Fishlake National Forest. This means that emissions from the Project would not affect visibility for an observer inside either of these areas.

VISCREEN also models effects to visibility for an observer standing 1 km from the ambient air boundary, looking toward an area in question (EPA 1992b). All locations passed the visibility screening criteria outside Fishlake National Forest except for FL2 and FL4. In addition, the visibility outside Great Basin National Park also did not pass the screening criteria. This means that emissions from the Project would reduce visibility for an observer standing 1 km from the ambient air boundary, looking toward the Great Basin National Park or locations FL2 and FL4 on the Fishlake National Forest. Note that VISCREEN does not account for intervening topography, which in the case of the Project would screen both the Great Basin National Park and Fishlake National Forest from view by the observer, regardless of any effects to visibility caused by Project emissions.

VISCREEN is a conservative screening model for visibility. The emissions entered are the annualized maximum daily values (that is, the maximum daily amount running for 365 days). For the Project, this is 851 tpy of PM10 and 121 tpy of NOX. This level of emissions is not realistic, and the actual annual emissions would be much lower. For the maximum year 2025, PM10 emissions would be 588 tpy and NO2 emissions would be 106 tpy (Table 15). Emissions from other years would be even lower (Table 15).

If the Project were implemented, the PM10 and NOX emissions would not affect the visibility inside Great Basin National Park and Fishlake National Forest. As viewed from a point 1 km outside the ambient air boundary, PM10 and NOX emissions would have minimal effects on visibility because the actual annual emissions would be lower than the modeled emissions and the VISCREEN model disregards the screening effect of intervening topography.

Table 43 Summary of VISCREEN Level 2 Meteorological Parameters

Observer Distance Wind 1% Worst Case Complex Terrain Adjusted 1% Worst- Point (km) / (mi) Direction Dispersion Level Adjustment? Case Dispersion Level Stability Class E Stability Class D GB1 86 / 53 East Wind Speed 3 m/s Y Wind Speed 3 m/s Stability Class F Stability Class F FL1 89 / 55 Southwest Wind Speed 3 m/s N Wind Speed 3 m/s West- Stability Class E Stability Class E FL2 78 / 48 southwest Wind Speed 4 m/s N Wind Speed 4 m/s Stability Class D Stability Class C FL3 71 / 44 West Wind Speed 8 m/s Y Wind Speed 8 m/s

85 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 43 Summary of VISCREEN Level 2 Meteorological Parameters

Observer Distance Wind 1% Worst Case Complex Terrain Adjusted 1% Worst- Point (km) / (mi) Direction Dispersion Level Adjustment? Case Dispersion Level West- Stability Class D Stability Class C FL4 57 / 35 northwest Wind Speed 4 m/s Y Wind Speed 4 m/s Stability Class D Stability Class C FL5 60 / 37 Northwest Wind Speed 7 m/s Y Wind Speed 7 m/s North- Stability Class D Stability Class C FL6 87 / 54 northwest Wind Speed 8 m/s Y Wind Speed 8 m/s

Table 44 VISCREEN Level 2 Results for Year 2025 Daily Maximum Emissions

Inside Park2 Outside Park3 Class II Observer Background ΔE Contrast ΔE Contrast Area Location / Sun Angle1 (Criteria=2.0) (Criteria = 0.05) (Criteria=2.0) (Criteria = 0.05) Sky 10 1.2 0.02 1.8 0.02 Sky 140 0.3 -0.01 0.5 -0.01 FL1 Terrain 10 1.3 0.01 1.6 0.02 Terrain 140 0.1 0.00 0.4 0.01 Sky 10 0.5 0.01 4.1 0.05 Sky 140 0.1 0.00 1.1 -0.03 FL2 Terrain 10 0.6 0.01 4.0 0.04 Terrain 140 0.0 0.00 1.3 0.03 Sky 10 0.0 0.00 0.9 0.01 Sky 140 0.0 0.00 0.2 -0.01 FL3 Terrain 10 0.0 0.00 1.0 0.01 Fishlake Terrain 140 0.0 0.00 0.3 0.01 National Forest Sky 10 0.0 0.00 2.3 0.03 Sky 140 0.0 0.00 0.6 -0.02 FL4 Terrain 10 0.1 0.00 2.8 0.03 Terrain 140 0.0 0.00 0.6 0.02 Sky 10 0.0 0.00 1.3 0.02 Sky 140 0.0 0.00 0.3 -0.01 FL5 Terrain 10 0.0 0.00 1.5 0.02 Terrain 140 0.0 0.00 0.4 0.01 Sky 10 0.0 0.00 0.7 0.01 Sky 140 0.0 0.00 0.2 -0.01 FL6 Terrain 10 0.0 0.00 0.7 0.01 Terrain 140 0.0 0.00 0.2 0.01 Sky 10 0.2 0.00 3.3 0.04 Great Basin Sky 140 0.1 0.00 0.9 -0.02 National GB1 Park Terrain 10 0.3 0.00 3.1 0.03 Terrain 140 0.0 0.00 1.0 0.02

86 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 44 VISCREEN Level 2 Results for Year 2025 Daily Maximum Emissions

Inside Park2 Outside Park3 Class II Observer Background ΔE Contrast ΔE Contrast Area Location / Sun Angle1 (Criteria=2.0) (Criteria = 0.05) (Criteria=2.0) (Criteria = 0.05) 1 A sun angle of 10 means the sun is in front of the observer while a sun angle of 140 means the sun is behind the observer. 2 These results would be experienced by a viewer inside the Great Basin National Park or Fishlake National Forest. Modelled values lower than the criteria values indicate visibility would not be affected. 3 These results would be experienced by a viewer standing 1 km from the Project’s ambient air boundary, looking toward either the Great Basin National Park or Fishlake National Forest. Modelled values lower than the criteria values indicate visibility would not be affected. Modelled values higher than the criteria values indicate visibility of these areas would be reduced for the viewer.

7.2.1.6 Greenhouse Gas Emissions

Ramboll (2019c) estimated GHG emissions for each year from all fuel combustion activities for the Project based on activity level and readily accepted emission factors. The Project would have no other sources of GHGs. The fuel combustion activities consist of both stationary and mobile sources, as summarized in Table 7. The stationary sources would include generators and dryers. The mobile sources would include heavy-duty equipment, light-duty vehicles, truck transport of product, and railroad emissions for idling, short haul, and a 100-km long-haul round trip. Emission factors were obtained from MOVES2014a, MOVES-NONROAD, EPA publications (EPA 2010b, 2015), as well as other published factors, employing the same methodology used for the criteria pollutants.

The three GHGs emitted from all Project sources would be CO2, CH4, and N2O, with the vast majority (greater than 99%) being CO2. The maximum GHG emissions from the Project would occur during CYr 2022 (PYr 4) as summarized in Table 45. The annual railroad emissions from CYr 2024 to 2053 are also presented. The railroad would not operate in year 2022. In the years the railroad is operating, GHG emissions from the Project would be lower. Ramboll calculated the CO2e based on the emissions of these three GHGs and their respective AR4 GWP (Table 34), which are the same GWPs listed in 40 CFR Part 98, Subpart A (2017f) for GHG reporting. Using these GWPs allows for direct comparison between the Project CO2e emissions and the national inventories developed by EPA. The maximum annual CO2e emissions over the 35-year life of the Project would be 26,893 metric tons (0.03 mmt) (29,644 tons). This represents about 0.0005 percent of the 2016 U.S. CO2e emissions of 6,511.3 mmt (Table 35) (7.2 billion tons), 0.05 percent of 2015 Utah’s CO2e emissions of 63.2 mmt (69.7 million tons), and 0.31 percent of 2016 Milliard County CO2e emissions of 8.7 mmt (9.6 million tons) (EPA 2018e). The Project would be a negligible contributor to GHG emissions at the county, state, and national levels.

Table 45 Maximum Annual GHG Emissions

Emissions Source CO2 CH4 N2O CO2e Category MT tons MT tons MT tons MT tons CYr 2022 / PYr 4 Construction On-Road ------4,532 4,996 Travel(1) Construction Off-Road 5,134 5,659 0.039 0.042 0.238 0.263 5,206 5,738 Equipment

87 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 45 Maximum Annual GHG Emissions

Emissions Source CO2 CH4 N2O CO2e Category MT tons MT tons MT tons MT tons Construction Stationary 4,249 4,683 0.026 0.029 0.197 0.217 4,308 4,749 Sources Operational On-Road ------52 57 Travel(1) Operational Off-Road 3,094 3,411 0.019 0.021 0.144 0.158 3,138 3,458 Equipment Operational Stationary 9,616 10,600 0.448 0.494 0.101 0.111 9,658 10,645 Source Rail Loadout(2) NA NA NA NA NA NA NA NA Total ------26,893 29,644 Rail Operations CYr 2024 to 2053 (PYr 6 to 35) Locomotive short line haul 20.0 22.1 0.002 0.002 0.001 0.001 20.2 22.3 Locomotive long line haul 311.3 343.2 0.024 0.027 0.008 0.009 314.3 346.5 Locomotive - switching 27.6 30.5 0.002 0.002 0.001 0.001 27.9 30.8 1 A breakdown of the specific GHG emissions of CO2, CH4, and N2O was not available from the emissions model used, only CO2e. 2 The railroad would not operate in CYr 2022 / PYr 4.

7.2.1.7 Climate Change

As discussed in Section 6.5, the major GHGs are CO2, CH4, N2O, and fluorinated compounds, while other important GHGs include water vapor, O3 in the troposphere, ozone precursors, and black carbon aerosols. GHGs can be produced by both anthropogenic activity and natural sources. The major GHGs can remain in the atmosphere from decades to centuries to thousands of years, depending on the particular GHG and removal processes involved. The other important GHGs have a much shorter atmospheric life of less than a year. Once in the atmosphere, GHGs cause a net warming effect by decreasing the amount of heat energy radiated back into space by the earth. By trapping heat, the GHGs exert a warming force on the earth’s temperature that is similar to glass in a greenhouse. Three factors influence how strongly a specific GHG affects the climate: 1) how long the gas remains in the atmosphere (that is, its “lifetime”); 2) individual heat absorbing properties of the gas; and 3) the overall atmospheric concentration of the GHG. The greenhouse effect on Earth is primarily a function of the concentrations of water vapor (the most abundant greenhouse gas in the atmosphere), CO2, CH4, N2O, and other trace GHGs (EPA 2016a; 2018c).

The gases CO2, CH4, and N2O are continuously emitted to and removed from the atmosphere by natural processes. Natural activities such as respiration by plants or animals and seasonal cycles of plant growth and decay are examples of processes that only cycle carbon or nitrogen between the atmosphere and organic biomass. Such processes generally do not alter average atmospheric GHG concentrations over decadal timeframes. However, emissions from anthropogenic activities cause additional quantities of these and other GHGs to be emitted or sequestered, thereby changing the global average atmospheric concentrations. Climatic changes resulting from anthropogenic activities, however, could have positive or negative feedback effects on the natural processes (EPA 2018f).

88 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Atmospheric concentrations of certain GHGs, along with their rates of growth and atmospheric lifetimes, are presented in Table 46 (EPA 2018f). In the pre-industrial era, the concentration of CO2 was 280 ppm, and this level increased to over 400 ppm in 2016. For CH4, the concentration has more than doubled over this same period, while N2O levels have increased by about 21 percent. Chlorofluorocarbons (CFCs) and sulfur hexafluoride (SF6) are highly potent GHGs primarily emitted by anthropogenic sources and were thus not found (or found only at very low concentrations) in the atmosphere in the pre-industrial era. These GHGs have concentrations in the parts per trillion (ppt) range.

Table 46 Historic and Current Greenhouse Gas Atmospheric Concentrations

Atmospheric Variable CO2 CH4 N2O SF6 CF4 Pre-industrial atmospheric 280 ppm 0.700 ppm 0.270 ppm 0 ppt 40 ppt concentration Atmospheric concentration 404 ppma 1.834 ppmb 0.329 ppmb 8.9 pptb 79 pptc Rate of concentration change 2.3 ppm/yr 7 ppb/yrd,e 0.8 ppb/yre 0.27 ppt/yre 0.7 ppt/yre Atmospheric lifetime (years) 0 to >100 12.4 121 3,200 50,000 a 2016 annual average concentration at Mauna Loa, Hawaii. b 2016 global annual average mole fraction. c 2011 mean annual concentration d Growth rate decreases from 10 ppb/yr in the 1980s to near zero in the 2000s. Recent growth rate is 7 ppb/year e Growth rate between the years 2007 to 2016.

Human population doubled to two billion from the period 1780 to 1930, and then doubled again by 1974. The atmospheric concentrations of GHGs have increased as human populations have increased. More land and resources were used to provide for the needs of these populations. As human activities increased, carbon-based fuels provided for additional energy needs. Forests and vegetation were cleared in order to provide for food production and human use.

The IPCC in 2014 released their Synthesis Report (IPCC 2014), the final part of the Fifth Assessment Report (AR5). The Synthesis Report summarizes the results of the AR5 assessment carried out by the three working groups of the IPCC. Analyses of historic trend data show an increase in global mean temperature, representing both land and ocean surfaces, of 0.85°C (1.53°F) over the period 1880 to 2012. This global warming has caused sea levels to rise by an average of about 19 centimeters (8 inches) and has resulted in changes in climate patterns on land. However, the observed global warming trend is not consistent across time with substantial decadal variability over this period. For some decades, the global mean temperature dropped or stayed relatively consistent, while for other decades the global mean temperatures exhibited warming. Isolating the analysis to the Northern Hemisphere, temperatures experienced during the recent period 1983 to 2012 were very likely the warmest in the last 800 years. Global warming is also not consistent across latitude or continents. For the period 1901 to 2012, more warming in surface temperature was observed across the higher latitudes of Eurasia and North America, as well as eastern portions of South America. Decreases in surface temperature were observed in the northern Atlantic Ocean as well as portions of southeastern North America. The United States average temperature has warmed by 0.7°C (1.3°F) to 1.05°C (1.9°F) since 1895, with most of this increase occurring after 1970; the most recent decade represents the warmest on record (Melillo et al. 2014).

The climate modeling analyses summarized in the Synthesis Report indicate that global mean surface temperatures would increase above the 1986 to 2005 levels from approximately 1.0°C (1.8°F) to 3.7°C

89 Sevier Playa Potash Project Resource Report: Air Quality and Climate

(6.7°F) by 2100, depending on how much GHG emissions increase. The models also predicted that temperature changes would not be uniform across the planet, with differences associated with location (over land or over the ocean) or latitude. Expected land temperature changes are much greater than ocean temperature changes, by about a factor of 1.5. The Arctic region is projected to experience the most warming, with the Antarctic region not experiencing similar increases because of deep ocean mixing and the Antarctic ice sheet. The models also show that it is very likely that there would be more frequent high temperature extremes and fewer cold temperature extremes over most land areas for both daily and seasonal timescales. In addition, the models show that it is very likely that there would be a higher frequency and longer duration of heat waves; however, occasional cold winter extremes would continue to occur.

The models predict that changes in precipitation would also not be uniform. An increase in mean annual precipitation is likely to occur at the high latitudes and the equatorial Pacific, while a decrease in mean annual precipitation is likely to occur in many mid-latitude and subtropical dry regions. Extreme precipitation events over most of the mid-latitude land masses and over wet tropical regions would very likely become more intense and more frequent.

The Synthesis Report includes the following observations and projections (emphasis that of IPCC):

• “Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperature, widespread melting of snow and ice, and rising global average sea level.”

• “Anthropogenic greenhouse gas emissions have increased since the pre-industrial era, driven largely by economic and population growth, and are now higher than ever. This has led to atmospheric concentrations of carbon dioxide, methane, and nitrous oxide that are unprecedented in at least the last 800,000 years. Their effects, together with those of other anthropogenic drivers, have been detected throughout the climate system and are extremely likely to have been the dominant cause of the observed warming since the mid-20th century.”

• “In recent decades, changes in climate have caused impacts on natural and human systems on all continents and across the oceans. Impacts are due to observed climate change, irrespective of its cause, indicating the sensitivity of natural and human systems to changing climate.”

• “Changes in many extreme weather and climate events have been observed since about 1950. Some of these changes have been linked to human influences, including a decrease in cold temperature extremes, an increase in warm temperature extremes, an increase in extreme high sea levels, and an increase in the number of heavy precipitation events in a number of regions.”

• “Continued emission of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system, increasing the likelihood of severe, pervasive, and irreversible impacts for people and ecosystems. Limiting climate change would require substantial and sustained reductions in greenhouse gas emissions which, together with adaptation, can limit climate change risks.”

• “Cumulative emissions of CO2 largely determine global mean surface warming by the late 21st century and beyond. Projections of greenhouse gas emissions vary over a wide range, depending on both socio-economic development and climate policy. “

• “Surface temperature is projected to rise over the 21st century under all assessed emission scenarios. It is very likely that heat waves will occur more often and last longer, and that extreme

90 Sevier Playa Potash Project Resource Report: Air Quality and Climate

precipitation events will become more intense and frequent in many regions. The ocean will continue to warm and acidify, and global mean sea level to rise.”

• “Global mean sea level will continue to rise during the 21st century…. Under all [Representative Concentration Pathway] scenarios, the rate of sea level rise will very likely exceed the observed rate … during 1971–2010…”

• “Many aspects of climate change and its associated impacts will continue for centuries, even if anthropogenic emissions of greenhouse gases are stopped. The risks of abrupt or irreversible changes increase as the magnitude of the warming increases.”

• “Without additional mitigation efforts beyond those in place today, and even with adaptation, warming by the end of the 21st century will lead to high to very high risk of severe, widespread and irreversible impacts globally (high confidence). Mitigation involves some level of co-benefits and of risks due to adverse side effects, but these risks do not involve the same possibility of severe, widespread and irreversible impacts as risks from climate change, increasing the benefits from near-term mitigation efforts.”

• “There are multiple mitigation pathways that are likely to limit warming to below 2°C relative to pre-industrial levels. These pathways would require substantial emissions reductions over the next few decades and near zero emissions of CO2 and other long-lived greenhouse gases by the end of the century. Implementing such reductions poses substantial technological, economic, social, and institutional challenges, which increase with delays in additional mitigation and if key technologies are not available. Limiting warming to lower or higher levels involves similar challenges but on different timescales.”

The National Academy of Sciences has agreed with the findings of IPCC, and briefly summarized their analysis in a booklet, Climate Change Evidence and Cause (National Academy of Sciences 2008). Even with the overall observed global warming, local effects still have strong influences. Relatively steep elevation gradients between valley floors and adjacent mountain ranges in the western U.S. produce considerable geographic climate variability by themselves. Warm, dry, semiarid conditions are typical on valley floors; moist and cool conditions are typical in higher parts of mountain ranges. Different plant communities occur within specific elevation zones. There also have been patterns of historic climatic variation in these areas for more than 10,000 years, during which plant communities gradually shift to higher or lower elevations depending on the direction of temperature and precipitation changes (Tausch et. al. 2004).

The U.S. Global Change Research Program (USGRP) assessed the current state of climate as well as the projected state of the climate for both the nation and specific regions in their document Impacts, Risks, and Adaptation in the United States: Fourth National Climate Assessment, Volume II (USGRP 2018). The Southwest region, which encompasses Arizona, California, Colorado, Nevada, New Mexico, and Utah, is the hottest and driest part of the United States. Climate change has brought wide-ranging effects to the region. Drought conditions in California and the Colorado River Basin have been intensified by higher temperatures. Lake Mead has lost 60 percent of its volume since 2000 from increased water withdrawal by cities and agriculture and decreased water inflow. Heat-related mortality has increased, with further exacerbation on high pollution (ozone or PM) days. The region experiences a higher than normal morbidity rate from West Nile Virus, plague, hantavirus, pulmonary syndrome, and Valley fever. Areas burned by wild fires from 1984 to 2015 are double from what would have happened had climate change not occurred. In addition, tree deaths for mid-elevation conifers have doubled during the 1955 to 2007 time period, partly due to climate change. The sea level near the Golden Gate Bridge in San Francisco has risen 9 inches from 1854 to 2016. From about 1750 to 2014, ocean acidity off the

91 Sevier Playa Potash Project Resource Report: Air Quality and Climate

California coast has increased by 25 to 40 percent from increasing amounts of atmospheric carbon dioxide. Crop failures rates have climbed due to increased heat stress during specific plant life cycles. The drought caused a 66 percent reduction in generation of hydroelectric power from 2011 to 2015. Droughts and the increasing arid conditions have led to hardship conditions for the Indigenous peoples, with declines in flows of specific water springs and seeps, culturally significant crops, and wildlife populations.

If global warming trends continue under the higher GHG emissions scenario, the USGRP predicts the following effects for the region:

• Regional average temperatures are projected to rise by 8.6°F by the end of the century. Summertime high temperatures in the southern part of the region could exceed 90°F for 45 days or more. These changes will cause increased risk of heat stress in the population.

• Temperature increases would contribute to changes in precipitation type (snow versus rain). Mountain areas in California that currently receive mostly snow in the winter would get only rain by the year 2050. For the intermountain west, the colder areas would receive more rain than snow in the fall and spring, but would still experience snow in the winter at the higher elevations.

• Temperature increases would also contribute to a potential permanent drying of the environment via lower soil moisture, increased evapotranspiration, reduced snow cover, slower and earlier snowmelt, and changes to the efficiency and timing of snowmelt. These higher temperatures increase the risk of mega droughts, which are droughts that last for ten years or more.

• The frequency of dry high pressure systems may increase and would cause an increase in the duration and severity of droughts as well as add to an overall drier climate.

• Flood risk from downpours would increase due to an increased frequency of “atmospheric rivers”, which are narrow, highly concentrated moisture bands and storms that move in over land from the Pacific Ocean. Extreme summertime precipitation will also increase across the region due to increased atmospheric water vapor from the higher temperatures. In addition, fewer days would have precipitation creating high year-to-year variability in precipitation amounts.

• River flows in the southern basins (the Rio Grande and the lower Colorado) are projected to decline, while river flows in the northern basins (northern California and the upper Colorado) are projected to either modestly increase or remain about the same. The combination of decreasing river flows in the southern basin and increasing population in the area would create a higher probability of water shortages.

• Wildfire frequency could increase 25 percent and the frequency of very large fires (greater than 5,000 hectares) could triple. Tree death from pests and high temperatures could increase.

• Sea level could rise, with the projected increase near San Francisco being 19 to 41 inches by the end of the century. Ocean temperatures off California could warm 4ºF to 7ºF above the 1980- 2005 average, which would lead to more harmful algae blooms, mortality of birds and sea lions, as well as cause economic damage to fisheries and other marine-dependent sectors. The acidity could also increase 40 percent above 1995 levels by 2050, negatively affecting shellfish fisheries. The warming waters may reduce oxygen levels below any naturally occurring levels by the year 2030 or 2050. This would harm numerous marine habitats at various ocean levels.

92 Sevier Playa Potash Project Resource Report: Air Quality and Climate

• Due to declines in snowpack and runoff, hydroelectric power could be reduced by 15 percent by 2050. Because higher temperatures increase electricity resistance, transmission loss across lines could reach 7 percent by 2080. At the same time, water demand by thermoelectric power plants is expected to increase by 8 percent by 2100.

• Crop yields are expected to be reduced due to increased heat stress, decreased winter chills, and increased strain on water irrigation resources. Hardiness zones for plants would shift north and upslope. Livestock long-term grazing capacity would be reduced.

• Heat-associated deaths and morbidity are projected to increase due to extreme heat, poor air quality, and an increase in pathogen growth and spread.

Overall, while it is apparent that global warming has occurred over the last 150 years, the climate change models cannot be used to predict future climate changes at regional and small scales. According to IPCC’s Fifth Assessment Report, The Physical Science Basis (IPCC 2013), there is considerable confidence that climate models provide credible quantitative estimates of future climate change, particularly at continental scales and above, but the confidence of the changes projected by global models decreases at smaller scales. Models are becoming more comprehensive and sophisticated in representing observed climate and past climate changes; however, models continue to have substantial limitations that lead to uncertainties in magnitude and timing, as well as regional details of predicting climate change. By taking the average of all models, known as the ensemble approach, a more accurate representation of the climate emerges. Global climate models are at this time imperfect and due to their uncertainties should not be used as the only basis for public policy decisions.

The Project would be a minor source of GHGs. As stated above, if the Project were implemented, the amount of CO2e emissions would increase by a small fraction, as compared to national and state totals. Climate change is a complex process with many unknowns. Climate change represents the cumulative effects of all worldwide GHG emissions, land use management practices, sinks, and other factors, known and unknown. The Project’s impact on climate change would be negligible and not discernible from the climate change that is occurring.

7.2.2 Action Alternatives

If selected, Alternatives 1, 2, 3, 4 or 5 would be implemented during the initial construction portion of the Project. The disturbed areas for these alternatives would be similar to or slightly larger than the equivalent segments of the proposed action; however, with implementation of applicant committed design features, including the measures in the FDCP (CPM 2019f), no measureable difference in PM or other emissions is expected for any of the alternatives.

Alternatives 1 through 5 would not affect the operation phase of the Project, and the production level would remain the same as in the proposed action. All sources in the Operation / Concurrent Construction Phase (2024-2053) would be the same as in the proposed action, as no alterations to the Mining Plan would occur. As a result, the maximum emission years for the Project would not be affected, nor would the placement of the sources be altered. The predicted effects for all pollutants and averaging periods under Alternatives 1, 2, 3, 4 and 5 would be identical to the proposed action.

7.2.3 No Action Alternative

Under the No Action alternative, the Project would not be implemented as described in the proposed action. There would be no new emissions or effects to air quality or climate. Air quality in the analysis area would not change from current background levels. At its discretion, CPM may retain control of its

93 Sevier Playa Potash Project Resource Report: Air Quality and Climate leases and the right to extract minerals from those leases, which would require submittal of a new Mining Plan and POD, as well as completion of the NEPA process, including a new analysis of potential effects to air quality.

7.3 Cumulative Effects

The NEPA requires federal agencies to consider the cumulative effects of proposals under their review. Cumulative effects are defined by the CEQ as “the impact on the environment which results from the incremental impact of the action when added to other past, present, and reasonably foreseeable future actions regardless of what agency (federal or non-federal) or person undertakes such other actions. Cumulative impacts can result from individually minor but collectively significant actions taking place over a period of time” (40 CFR 1508.7).

This section describes, compares, and contrasts the anticipated cumulative effects of the proposed action, action alternatives, and no action alternative on air quality and climate. A complete list of past, present, and reasonably foreseeable future projects that were considered is provided in Appendix M in the EIS. The primary past, present, and reasonably foreseeable future actions (cumulative actions) that could contribute to cumulative effects to air quality and climate in conjunction with the direct and indirect effects of the Project include:

• Graymont / Cricket Mountain Mine/Quarry, located approximately 8 km (5 miles) east of the Sevier Playa

• Graymont / Cricket Mountain Lime Plant, located approximately 21 km (13 miles) east of the Sevier Playa

Two other sources were included in the modeling to be conservative, even though they are located outside the analysis area. These sources are:

• Intermountain Power Project (IPP), located approximately 76 km (47 miles) northeast of the Sevier Playa

• Kern River Gas Transmission System (Fillmore Compressor Station) (listed by EPA [2018e] as MidAmerican Energy), located approximately 56 km (35 miles) east-southeast of the Sevier Playa

Three cumulative sources were identified as potentially contributing to the cumulative effects; however, information on these sources is insufficient for air dispersion modeling purposes. These sources include the following:

• Graymont 1,956 acres, limestone quarry, approximately 12 miles east of the Sevier Playa, pending operations, current plan incomplete

• Smithfield Hog Farms, first phase in Beaver County and second phase in Millard County.

• Frontier Observatory for Research into Geothermal Energy (FORGE) Project, located on state and private lands in Beaver County, about 10 miles north of Milford.

These sources were not included in the model and potential cumulative effects from these three sources could not be quantified.

94 Sevier Playa Potash Project Resource Report: Air Quality and Climate

7.3.1 Proposed Action

7.3.1.1 Fugitive Dust Emissions

The cumulative sources do not emit enough fugitive dust to be considered additive to the fugitive dust emissions of the Project. Fugitive dust tends to be localized to the immediate area of the activities generating the dust, as seen in Figure 7 for the Project modeling analysis. Thus, no cumulative effect from fugitive dust from the cumulative sources is anticipated if the Project is implemented, especially at the Project’s ambient air boundary where Project’s effects would be highest.

7.3.1.2 Other Emissions

The cumulative sources emit CO and NOX at high enough levels to contribute to cumulative effects with the Project. These are evaluated further in Section 7.3.1.3. For SO2, VOCs, and process-related PM10 and PM2.5, the amount of emissions is small enough that no additional effects are anticipated. This was assessed by taking the ratio of background source emissions (tpy) to the distance (km) between the Project and the background source. If this ratio is less than or equal to 10, the impact of the background source is considered to be minimal. The modeling threshold ratio of 10 was provided by UDAQ, and is based on the same threshold used in screening for AQRV analyses (see Section 7.2.1.5)

7.3.1.3 National Ambient Air Quality Standards

To assess the cumulative effects for CO and NO2, the modeled concentrations from the Project and nearby regional sources were added to the respective background concentrations and the totals were compared against the applicable NAAQS (Table 47). For each pollutant and averaging period, the cumulative source concentrations represent the maximum modeled emissions over all of the receptors for the respective rank. The Project-only concentration is the Project’s contribution to the total concentration, (that is, the Project concentration that occurred at the same time and same receptor as the total concentration). The cumulative nearby sources concentration is the nearby sources’ contributions at the same time and receptor as the total concentration. The background concentration represents the existing air quality for the analysis area (see Section 5.5). The total concentration is the sum of the Project-only concentrations, the cumulative nearby sources concentration, and the background concentration. This sum is the value that is compared against the NAAQS. Each pollutant analyzed is discussed in the subsections below.

7.3.1.3.1 Carbon Monoxide

The modeled concentrations of emissions from the Project-only and cumulative nearby sources for both the 1-hour and 8-hour averaging periods for CO represent the highest of the second-high concentrations for all receptors. The cumulative concentration from the nearby sources at the Project-only maximum is very small for both 1-hour and 8-hour averaging periods. The total concentrations for the two averaging periods are well below the NAAQS (Table 47). If the Project were implemented, the cumulative CO emissions in the analysis area would be relatively minimal.

95 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Table 47 Comparison of Total Cumulative Concentrations to the NAAQS

Cumulative Project- Nearby Back- Only Sources ground Total Averaging Model Conc.(2) Conc. (3) Conc. (4) Conc. (5) NAAQS Exceeds Pollutant Period Rank (1) (µg/m3) (µg/m3) (µg/m3) (µg/m3) (µg/m3) NAAQS? 1-hour 2nd 3,431 0.22 3,435 6,866 40,000 No CO 8-hour 2nd 482.3 0.093 2,748 3,230 10,000 No 1-hour 8th 323.4 0.08 23.9(5) 347.4 188 Yes NO2 Annual 1st 23.8 0.098 3.8 27.7 100 No (1) Rank of the modeled concentration used when modeling for the NAAQS. (2) This concentration is the Project’s portion (contribution) to the total concentration. (3) This concentration is the portion (contribution) from the cumulative nearby sources to the total concentration. (4) Background concentration represents the existing air quality for the assessment area. See Section 5.5. (5) This is the seasonal hour background concentration for the same hour and season when the total concentration occurred. See Section 5.5. (6) Total concentration is the sum of the concentrations from the Project, cumulative sources, and background. This concentration is compared to the NAAQS.

7.3.1.3.2 Nitrogen Dioxide

The modeled concentration of emissions from the Project-only and cumulative nearby sources for 1-hour th NO2 represents the highest of the 8 high concentrations for all receptors. This concentration is much greater than the background air quality, and exceeds the NAAQS (Table 47). The cumulative concentration from the nearby sources at the Project-only maximum is very small. The background concentration shown in Table 47 is the representative concentration for the season and hour during which the highest 8th-high concentration occurred (Section 5.5.4). The total concentration exceeds the NAAQS.

Figure 11 depicts the areal coverage and distribution of the total cumulative 1-hour NO2 concentrations across the analysis area. Several isolated pockets of high 1-hour NO2 concentrations are shown with concentrations higher than the 1-hour NAAQS (inside the red contours). In addition to the high concentration areas near the Project (matching those seen in Figure 6), several additional exceedances are shown east of the Project. These specific areas are caused by the cumulative concentrations from the nearby sources, as labeled. Analyzing these eastern areas in more detail, AERMOD predicted 78 hour and receptor combinations for which the total concentration exceeded the NAAQS. The average Project-only concentrations paired in time with the same receptor for these exceedances was 0.008 μg/m3, with the maximum contribution at 0.0637 μg/m3.

Table 48 lists the top ten Project-only concentrations paired in time and receptor with the total emissions. In each case, the Project-only concentration is less than 0.04 percent of the total concentration. In addition, all Project-only concentrations are less than 7.5 μg/m3, which is the concentration level for 1- hour average that EPA would consider a source to be contributing to an exceedance.

96 Black Rock 4,335,000 Communication Tower

4,330,000

4,325,000

4,320,000 The exceedances in this region are due to other cumulative 4,315,000 sources, not SPP.

4,310,000

4,305,000

400 4,300,000

350

4,295,000

UTM Northing (Zone 12, NAD83, meters) 300

4,290,000 250 Maximum: 347.32 µg/m³

4,285,000 200

Background: Variable 4,280,000 150 NAAQS: 188 g/m3 Outer Limit of NAAQS Exceedance: Ambient Air Boundary: 4,275,000 100 BMU Outline: ( g/m3)

305,000 310,000 315,000 320,000 325,000 330,000 335,000 340,000 345,000 350,000 UTM Easting (Zone 12, NAD83, meters)

Source: Modified Figure A11 from Ramboll (2019a) Sevier Playa Potash Project Resource Report: Air Quality and Climate

THIS PAGE INTENTIONALLY LEFT BLANK

98 Sevier Playa Potash Project Resource Report: Air Quality and Climate

A more detailed analysis would have to be performed on the 78 exceedances of the 1-hour NO2 NAAQS in these eastern areas to better understand if exceedances are still shown. However, this level of effort is beyond the scope of the EIS analysis. In addition, modeled exceedances do not necessarily translate to actual monitored exceedances because of the conservative nature of the model and the modeling analysis (see Section 5.3.8).The BLM is not responsible for determining if an actual NAAQS exceedance exists; in Utah, this task falls to the regulatory agencies of UDAQ and EPA. Regardless of whether an actual exceedance exists or not, if the Project were implemented, the contribution from its sources at these eastern locations would be well below the 7.5 μg/m3 concentration level that EPA considers contributing to an exceedance. Thus, EPA and UDAQ would not identify the Project as contributing to these modeled exceedances, and the BLM would concur. All Project-only concentrations at these eastern locations and periods would have minimal effects on the total concentration.

The modeled concentration for annual NO2 for the cumulative sources represents the maximum concentration for all receptors. The cumulative concentration from the nearby sources at the Project-only maximum is very small. The total concentration is well below the NAAQS (Table 47). If the Project were implemented, the cumulative effects of annual NO2 emissions on the analysis area would be relatively minimal.

Table 48 Comparison of Highest 10 Project-Only Concentrations (1-hour NO2) with Total Cumulative Emissions above the NAAQS

Project-Only Cumulative Source Background Total Concentration (1) Concentration (2) Concentration (3) Concentration (4) (µg/m3) (µg/m3) (µg/m3) (µg/m3) 0.06370 169.4 23.1 192.6 0.06150 195.0 23.1 218.2 0.06090 212.5 26.9 239.5 0.05070 171.3 26.9 198.3 0.05030 226.7 33.8 260.6 0.05020 174.3 26.9 201.2 0.04140 202.9 26.9 229.8 0.03270 177.4 25.0 202.5 0.01670 180.5 33.8 214.4 0.01380 204.4 19.4 223.8 (1) Project-only emissions paired in time and space with the equivalent cumulative source concentrations. (2) Maximum modeled concentration from the cumulative nearby sources modeled over all receptors for the respective model rank (3) Background concentration represents the existing air quality for the analysis area. See Section 5.5. (4) Total concentration is the sum of Project-only concentrations, cumulative nearby source concentration, and background concentration. This concentration is compared to the NAAQS.

7.3.1.4 PSD Increments

No cumulative analysis was performed for PSD increments.

7.3.1.5 Class I and Class II Area AQRV Impacts

No cumulative analysis was performed for effects to AQRVs for Class I and Class II areas of interest.

99 Sevier Playa Potash Project Resource Report: Air Quality and Climate

7.3.1.6 Greenhouse Gas Emissions

If the Project were implemented, the maximum annual emissions of GHGs in the form of CO2e would be 26,893 metric tons (0.03 mmt) (29,644 tons) (Section 7.2.1.6). The only facility with reportable emissions in the analysis area is Graymont, with 0.77 mmt (844,625 tons) reported in 2016 (EPA 2018e). The three facilities in Millard County with reportable emissions, Graymont, IPP, and the Kern River Gas Transmission System (Fillmore Compressor Station), had total CO2e emissions of 8.7 mmt (9.6 million tons) reported in 2016 (EPA 2018e); therefore, at maximum emissions, the Project CO2e emissions would be 0.31 percent of the total CO2e emissions from Millard County. The Project’s maximum CO2e emissions represent about 0.05 percent of Utah’s 2016 CO2e emissions of 63.2 mmt (69.7 million tons) and about 0.0005 percent of the 2016 U.S. CO2e emissions of 6,511.3 mmt (Table 35) (7.2 billion tons). The Project would be a minor source of GHG emissions, and the addition of Project CO2e emissions would not cause noticeable cumulative effects to the Utah and national GHG emission inventories. The design features listed in Table 38 would be used as applicable to minimize emissions from Project sources, including Tier 4 engines and employing rail to transport the vast majority of product to market.

7.3.1.7 Climate Change

The IPCC (2014) concluded that “warming of the climate system is unequivocal” and “most of the observed increase in globally average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic GHG concentrations.” Section 7.2.1.7 contains a more detailed discussion on this topic.

Based on the Central Basin and Range Rapid Ecoregional Assessment (NatureServe 2013), increased warming and precipitation changes are projected to occur for the analysis area because of climate change. The July maximum temperature for the 2020’s decade is projected to increase 1.73 to 2.29ºF, while by 2060, the July maximum temperatures are expected to increase by more than 5ºF. Precipitation is expected to vary by two standard deviations from the 20th century mean. However, potential effects to air quality caused by climate change are likely to be varied. For example, if climate change results in a warmer and drier climate, particulate matter emissions could increase because of increased windblown dust from drier and less stable soils. Cool season plant species’ spatial ranges are predicted to move north and to higher elevations, and extinction of endemic threatened/endangered plants may be accelerated. The population of some animal species may be reduced because of loss of habitat or competition from other species whose ranges may shift northward. Less snow at lower elevations would be likely to affect the timing and quantity of snowmelt, which, in turn, could affect aquatic species. The Project does have GHG emissions and would contribute to climate change; however, because it is a minor source its effects alone would be negligible and not discernible from broader regional and global trends.

7.3.2 Action Alternatives

Alternatives 1, 2, 3, 4, or 5 would be implemented during the initial construction portion of the Project. Since no measurable differences in any pollutant emissions are expected from any of the alternatives, there would be no difference in cumulative emissions compared to the proposed action.

Alternatives 1 through 5 would not affect the operation phase of the Project, and the production level would remain the same as in the proposed action. All sources in the Operation / Concurrent Construction Phase (2024-2053) would be the same as in the proposed action, with no alterations to the Mining Plan. As a result, the maximum emission years for the Project would not be affected nor would the location of sources be altered. The predicted cumulative emissions of all pollutants and averaging periods under Alternatives 1, 2, 3, 4 and 5 would be identical to those for the proposed action.

100 Sevier Playa Potash Project Resource Report: Air Quality and Climate

7.3.3 No Action Alternative

Under the No Action alternative, the Project would not be implemented as described in the proposed action and there would be no new emissions or effects to air quality or climate; therefore, there would be no cumulative effects to air quality or climate. At its discretion, CPM may retain control of its leases and the right to extract minerals from those leases, which would require submittal of a new Mining Plan and POD, as well as completion of the NEPA process, including a new analysis of potential cumulative effects to air quality and climate.

7.4 Additional Recommended Mitigation

During the analysis of effects, the BLM identified one mitigation measure in addition to the applicant committed design features in Appendix K in the EIS and the supplemental plans that would reduce the adverse effects of the Project. The BLM will include this measure in the ROD, should the proposed action or action alternatives be selected for implementation. This measure is listed as follows;

• CPM shall use equipment that at a minimum meets the pollution controls for equivalent equipment to that included in the Final Air Dispersion Modeling Report for NEPA Analysis (Ramboll 2019a).

This design feature applies to all construction, operation, maintenance, and decommissioning activities that take place on or off the playa. This provides assurance that the modeled emissions would not be less than what would occur for the Project. 8.0 Conformance with Applicable Land Use Plans, Policies, and Controls

This section discusses conformance with the applicable regulations from Section 4.0, if the Project is implemented as described in Section 2.0.

8.1 NAAQS

The air dispersion modeling analysis for Project-only emissions in the analysis area predicted that the Project would meet the NAAQS for PM2.5, CO, SO2, and O3 for all applicable averaging periods, as well as the NAAQS for annual PM10 and annual NO2. For 24-hour PM10, the modeling for Project-only emissions predicted that the Project would meet the NAAQS when seasonal background concentrations are used, while the Project would exceed the NAAQS when the highest second-high modeled concentration is combined with the second highest monitored concentration. For the 1-hour NO2, the modeling for Project-only emissions predicted that the Project would exceed the NAAQS. The model predicted that these exceedances would occur in small, isolated areas and concentrations would drop below the NAAQS within 500 meters (1,640 feet) of these areas.

The modeling analysis for the cumulative effects of the Project predicted that the 1-hour CO, 8-hour CO and annual NO2 standards would be met, while the 1-hour NO2 standard would be exceeded. Beyond the exceedances from the Project-only emissions described above, several areas of exceedance were predicted east of the Project in proximity to nearby cumulative sources. The predicted emissions from the Project at the same time and location of these eastern exceedances would be very small (less than 0.07 μg/m3), and as such would not contribute to these exceedances caused by emissions from cumulative sources.

The cumulative source emissions of PM10, PM2.5, and SO2 were small given their distance from the Project, and thus would not combine with the respective Project emissions.

101 Sevier Playa Potash Project Resource Report: Air Quality and Climate

8.2 New Source Review / Prevention of Significant Deterioration

The Project would have maximum annual stationary source emissions of 56.9 tpy of PM10, 38.1 tpy of PM2.5, 5.4 tpy of NOX, 34.0 tpy of CO, and <0.1 tpy of SO2. The Project would have fugitive source emissions of 530.7 tpy of PM10, 69.2 tpy of PM2.5, 151.6 tpy of NOX, 315.0 tpy of CO and 0.3 tpy of SO2. The Project would not be required to include fugitive emissions towards major source thresholds because it is not one of the sources listed in 40 CFR Part 52.21(b)(1)(i)(a) or 40 CFR Part 52.21(b)(1)(iii). The Project would be a minor source because the sum of the non-fugitive emissions would be less than 250 tpy for each criteria pollutant. Before it is constructed, the Project would be required to go through minor NSR and obtain an Approval Order from the UDAQ. As part of the application, the Project would be required to demonstrate compliance with all applicable state requirements.

Even though the Project is not a PSD major source, modeled Project-only emissions were compared to PSD increments as a full public disclosure measure. The pollutants predicted to be above increment were 24-hour and annual PM10 and 24-hour and annual PM2.5. The concentration of these pollutants dropped below increment levels within about 50 m (164 feet) from the maximum areas. Project-only emissions were modeled for the Fishlake National Forest and compared against PSD Class I and Class II increments. The predicted concentrations were all below 4 percent of the Class II values for all applicable pollutants and averaging periods and below 32 percent of the Class I values for all applicable pollutants and averaging periods.

8.3 New Source Performance Standards / National Emission Standards for Hazardous Air Pollutants

For NSPS, the Project would have sources at the Processing Facility that have potentially applicable requirements under 40 CFR Part 60 Subpart OOO (EPA 2017g) and 40 CFR Part 60 Subpart UUU (EPA 2017h). The Project would have to meet the applicable requirements specified in these subparts, which would be addressed in the Approval Order from UDAQ. Any other Project sources that would be covered under 40 CFR Part 60 would be addressed in the same manner. For NESHAP, the Project as proposed would not have sources covered under this regulation.

8.4 Federal Operating Permit

The Project would have maximum annual stationary source emissions of 56.9 tpy of PM10, 38.1 tpy of PM2.5, 5.4 tpy of NOX, 34.0 tpy of CO, and <0.1 tpy of SO2. The Project would have fugitive source emissions of 530.7 tpy of PM10, 69.2 tpy of PM2.5, 151.6 tpy of NOX, 315.0 tpy of CO and 0.3 tpy of SO2. The Project would not be required to include fugitive emissions towards major source thresholds because it is not one of the sources listed in 40 CFR Part 52.21(b)(1)(i)(a) or 40 CFR Part 52.21(b)(1)(iii). The Project would be a minor source under this regulation because the sum of the non-fugitive emissions would be less than 100 tpy for each criteria pollutant. As a minor source, it would not be subject to operating permit requirements.

8.5 Air Quality Related Values

AQRV analyses for Class I and Class II areas of interest are typically performed only for major PSD sources. However, as a full public disclosure measure, potential effects to AQRVs were reviewed for the Project, using a screening level analysis. The Project would have a Q/D ratio less than or equal to 10 for all Class I areas and as such would be considered to have a minimal effect on these areas.

102 Sevier Playa Potash Project Resource Report: Air Quality and Climate

The Level 2 visibility screening analysis for the two Class II areas of interest of Great Basin National Park and Fishlake National Forest predicted that the Project-only emissions would meet visibility criteria inside each Class II area of interest. Outside both Class II areas of interest, the screening model showed that the visibility criteria would be exceeded for some criteria at certain locations, while other locations passed all criteria. 9.0 References

Center for Climate Strategies. 2007. Utah Greenhouse Gas Inventory and Reference Case Projections, 1990-2020. Spring 2007. Crystal Peak Minerals. 2019a. Plan of Development for Off-Lease Facilities for the Sevier Playa Potash Project. April 2019. Crystal Peak Minerals. 2019b. Sevier Playa Potash Project. Adaptive Wildlife Management Plan. April 2019. Crystal Peak Minerals. 2019c. Sevier Playa Potash Project. Blasting Plan. April 2019. Crystal Peak Minerals. 2019d. Sevier Playa Potash Project. Cultural Resources Plan. April 2019. Crystal Peak Minerals. 2019e. Sevier Playa Potash Project. Environmental Compliance Inspection Plan. June 2019. Crystal Peak Minerals. 2019f. Sevier Playa Potash Project. Fugitive Dust Control Plan. April 2019. Crystal Peak Minerals. 2019g. Sevier Playa Potash Project. Noxious and Invasive Weed Management Plan. April 2019. Crystal Peak Minerals. 2019h. Sevier Playa Potash Project. Reclamation Plan. June 2019. Crystal Peak Minerals. 2019i. Sevier Playa Potash Project. Site Safety Plan. April 2019. Crystal Peak Minerals. 2019j. Sevier Playa Potash Project. Solid and Hazardous Waste and Hazardous Materials Management Plan. April 2019. Crystal Peak Minerals. 2019k. Sevier Playa Potash Project. Spill Prevention, Control, and Countermeasures Plan. May 2019. Crystal Peak Minerals. 2019l. Sevier Playa Potash Project. Stormwater Pollution Prevention Plan. May 2019. Crystal Peak Minerals. 2019m. Sevier Playa Potash Project. Transportation and Traffic Management Plan. May 2019. Crystal Peak Minerals. 2019n. Sevier Playa Potash Project. Water Monitoring Plan. May 2019. Crystal Peak Minerals. 2018. NI 43-101 Technical Report Summarizing the Feasibility Study for the Sevier Playa Potash Project, Millard County, Utah. Prepared for Crystal Peak Minerals Inc. by Novopro Projects Inc. and Norwest Corporation. Report Date: February 21, 2018. Effective Date: January 11, 2018. Crystal Peak Minerals and Stantec. 2019a. Mining Plan for the Sevier Playa Potash Project. BLM Case File Number UTU-88387. June 2019. Crystal Peak Minerals and Stantec. 2019b. Gravel Pit Mining Plan. February 2019. Intergovernmental Panel on Climate Change. 2013. Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T. F., D. Qin, G.-K. Plattner, M. Tignor, S. K. Allen, J. Boschung,

103 Sevier Playa Potash Project Resource Report: Air Quality and Climate

A. Nauels, Y. Xia, V. Bex and P. M. Midgley (editors)]. Cambridge University Press, Cambridge, United Kingdom and New York, New York, USA, 1535 pp. Intergovernmental Panel on Climate Change. 2014. Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, R. K. Pachauri and L. A. Meyer (editors)]. IPCC, Geneva, Switzerland, 151 pp. Melillo, J. M., T. C. Richmond, and G. W. Yohe, editors. 2014. Climate Change Impacts in the United States: The Third National Climate Assessment. U.S. Global Change Research Program, 841 pp. doi:10.7930/J0Z31WJ2. Mojave Desert Air Quality Management District. 1999. Emissions Inventory Guidance. Mineral Handling and Processing Industries. November 1999. National Academy of Sciences. 2008. Climate Change Evidence and Causes Booklet. National Oceanic and Atmospheric Administration. 2018. Global Historical Climatology Network data. Available online at: https://www.ncdc.noaa.gov/data-access. Accessed: January 2018. National Oceanic and Atmospheric Administration. 2015. Local Climatological Data, Annual Summary with Comparative Data, Salt Lake City, Utah, 2014. ISSN 0198-5280, 2015, Asheville, North Carolina. National Oceanic and Atmospheric Administration. 1989. Local Climatological Data, Annual Summary with Comparative Data, Milford, Utah, 1988. ISSN 0198-5264, 1989, Asheville, North Carolina. NatureServe. 2013. Central Basin and Range Rapid Ecoregional Assessment. Arlington, VA. Available online at: https://landscape.blm.gov/geoportal/catalog/REAs/REAs. Accessed June 3, 2019. Ramboll. 2019a. Final Air Dispersion Modeling Report for NEPA Analysis, Crystal Peak Minerals, Sevier Playa Potash Project. April 2019. Ramboll. 2019b. August 2017 Sampling Report Sevier Playa Potash Project. April 2017. Ramboll. 2019c. Email from Megan Neiderhiser to Kendall Necker and Matt Schweich; subject Update: SPP FEIS GHG Emissions (04/29); April 29, 2019, Attachment SPP_FEIS_GHG Inventory_Speciated_LIVE_042919.xlsx.2019. Ramboll. 2018. Final Air Dispersion Modeling Protocol for NEPA Analysis, Crystal Peak Minerals, Sevier Playa Potash Project. December 2018. Tausch, R. J., C. L. Nowak, and S. A. Mensing, 2004. “Climate Change and Associated Vegetation Dynamics During the Holocene: The Paleoecological Record.” Chapter 2 in Great Basin Riparian Ecosystems: Ecology, Management and Restoration, edited by J. C. Chambers and J. R. Miller, 24–48. Washington, DC: Island Press. U. S. Bureau of Land Management. 1987. Warm Springs Resource Area. The Resource Management Plan. Record of Decision and Rangeland Program Summary. U. S. Energy Information Administration. 2018: Energy-Related Carbon Dioxide Emissions by State, 2000- 2015. U.S. Department of Energy, Washington, D.C. January 2018. U. S. Environmental Protection Agency. 2018a. User’s Guide for the AMS/EPA Regulatory Model - AERMOD. EPA-454/B-18-001. U.S. Office of Air Quality Planning and Standards, Environmental Protection Agency. Research Triangle Park, North Carolina. April 2018. U. S. Environmental Protection Agency. 2018b. User’s Guide for the AERMOD Terrain Preprocesesor (AERMAP). EPA-454/B-18-004. Office of Air Quality Planning and Standards. Research Triangle Park, North Carolina. April 2018.

104 Sevier Playa Potash Project Resource Report: Air Quality and Climate

U. S. Environmental Protection Agency. 2018c. User’s Guide for the AERMOD Meteorological Preprocessor (AERMET). EPA-454/B-18-002. U.S. Office of Air Quality Planning and Standards, Environmental Protection Agency. Research Triangle Park, North Carolina. April 2018. U. S. Environmental Protection Agency. 2018d. Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2016. Annex 3, Part A, Table A-112. EPA 430-R-18-003. April 2018. U. S. Environmental Protection Agency. 2018e. EPA Greenhouse Gas Reporting Program website. Available online at: https://www.epa.gov/ghgreporting. Accessed August 17, 2018. U. S. Environmental Protection Agency. 2018f. Inventory of U.S. Greenhouse Gas Emissions and Sinks, 1990-2016. EPA-430/R-18-003, Washington DC. April 2018. U. S. Environmental Protection Agency. 2017a. 40 Code of Federal Regulations Part 51, Appendix W, Guideline on Air Quality Models. July 2017. U. S. Environmental Protection Agency. 2017b. 40 Code of Federal Regulations Part 52.21. July 2017. U. S. Environmental Protection Agency. 2017c. 40 Code of Federal Regulations Part 70. July 2017. U. S. Environmental Protection Agency. 2017d. EPA AQS Data Mart. Available online at: https://www.epa.gov/aqs. Accessed December 2017. U. S. Environmental Protection Agency. 2017e. AERMOD Model Formulation and Evaluation. EPA- 454/R-17-001. U.S. Office of Air Quality Planning and Standards, Environmental Protection Agency. Research Triangle Park, North Carolina. May 2017. U. S. Environmental Protection Agency. 2017f. 40 Code of Federal Regulations Part 98, Subpart A. July 2017. U. S. Environmental Protection Agency. 2017g. 40 Code of Federal Regulations Part 60 Subpart OOO. July 2017. U. S. Environmental Protection Agency. 2017h. 40 Code of Federal Regulations Part 60 Subpart UUU. July 2017. U. S. Environmental Protection Agency. 2016a. Climate Change Indicators in the United States, 2016, Fourth Edition. EPA 430-R-16-004. August 2016. U. S. Environmental Protection Agency. 2016b. Guidance on the Development of Modeled Emission Rates for Precursors (MERPs) as a Tier 1 Demonstration Tool for Ozone and PM2.5 Under the PSD Permitting Program. December 2016. U. S. Environmental Protection Agency. 2015. MOVES2014 and MOVES2014a Technical Guidance: Using MOVES to Prepare Emission Inventories for State Implementation Plans and Transportation Conformity. November 2015. U. S. Environmental Protection Agency. 2013. AERSURFACE User’s Guide. EPA-454/B-08-001. Office of Air Quality Planning and Standards. Research Triangle Park, North Carolina. January 2013. U. S. Environmental Protection Agency. 2012. Haul Road Workgroup Final Report Submission to EPA- OAQPS. March 2012. U. S. Environmental Protection Agency. 2011a. Fifth Edition Compilation of Air Pollutant Emission Factors, Volume 1, Chapter 13: Miscellaneous Sources. Section 13.2.1: Paved Roads. November 2011. U. S. Environmental Protection Agency. 2011b. Office of Air Quality Planning and Standards, Memorandum from Mr. Tyler Fox to Regional Air Division Directors. Additional Clarification

105 Sevier Playa Potash Project Resource Report: Air Quality and Climate

Regarding Application of Appendix W Modeling Guidance for the 1-hour NO2 National Ambient Air Quality Standard. March 2011. U. S. Environmental Protection Agency. 2010a. Federal Register 75: 35520. June 2010. U. S. Environmental Protection Agency. 2010b. Conversion Factors for Hydrocarbon Emission Components. EPA-420-R-10-015 NR-002d. July 2010. U. S. Environmental Protection Agency. 2009. Emission Factors for Locomotives. EPA-420-F-09-025. Office of Transportation and Air Quality. April 2009. U. S. Environmental Protection Agency. 2008. Fifth Edition Compilation of Air Pollutant Emission Factors, Volume 1, Chapter 1: External Combustion Sources. Section 1.5: Liquefied Petroleum Gas Combustion. July 2008. U. S. Environmental Protection Agency. 2006a. Fifth Edition Compilation of Air Pollutant Emission Factors, Volume 1, Chapter 13: Miscellaneous Sources. Section 13.2.4: Aggregate Handling and Storage Piles. November 2006. U. S. Environmental Protection Agency. 2006b. Fifth Edition Compilation of Air Pollutant Emission Factors, Volume 1, Chapter 13: Miscellaneous Sources. Section 13.2.5: Industrial Wind Erosion. November 2006. U. S. Environmental Protection Agency. 2006c. Fifth Edition Compilation of Air Pollutant Emission Factors, Volume 1, Chapter 13: Miscellaneous Sources. Section 13.2.2: Unpaved Roads. November 2006. U. S. Environmental Protection Agency. 2004a. Fifth Edition Compilation of Air Pollutant Emission Factors, Volume 1, Chapter 11: Mineral Products Industry. Section 11.19.2: Crushed Stone Processing and Pulverized Mineral Processing. August 2004. U. S. Environmental Protection Agency. 2004b. User's Guide to the Building Profile Input Program. EPA-454/R-93-038, Revised April 2004. U. S. Environmental Protection Agency. 1992a. Tutorial Package for the VISCREEN Model. Office of Air Quality Planning and Standards, Research Triangle Park, North Carolina. June 1992. U. S. Environmental Protection Agency. 1992b. Workbook for Plume Visual Impact Screening and Analysis (Revised). EPA-454/R-92-023. Office of Air Quality Planning and Standards, Research Triangle Park, North Carolina. October 1992. U.S. Environmental Protection Agency. 1987. Ambient Monitoring Guidelines for Prevention of Significant Deterioration (PSD). Office of Air Quality Planning and Standards, Research Triangle Park, North Carolina. U. S. Forest Service, National Park Service, and U. S. Fish and Wildlife Service. 2010. Federal Land Managers’ Air Quality Related Values Work Group (FLAG): Phase I Report—Revised (2010). Natural Resource Report NPS/NRPC/NRR—2010/232. National Park Service, Denver, Colorado. U.S. Global Change Research Program. 2018. Impacts, Risks, and Adaptation in the United States: Fourth National Climate Assessment, Volume II [Reidmiller, D. R., C. W. Avery, D. R. Easterling, K. E. Kunkel, K. L. M. Lewis, T. K. Maycock, and B. C. Stewart (eds.)]. U.S. Global Change Research Program, Washington, DC, USA. Utah Division of Air Quality. 2015. Memorandum from Mr. Regg Olsen (Branch Manager) to Permitting Branch. Emission Factors for Paved and Unpaved Haul Roads (January 12, 2015). Utah Division of Air Quality, 2013. Utah Division of Air Quality Emission Impact Assessment Guidelines. March 2013.

106