APPENDICES a Through D* Revised Preliminary Assessment North Fork Mancos Master Development Plan DOI-BLM-CO-N040-2017-0050-EA

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APPENDICES A through D* Revised Preliminary Assessment North Fork Mancos Master Development Plan DOI-BLM-CO-N040-2017-0050-EA

Appendix A. Figures, Maps, and Tables Appendix B. Conditions of Approval Appendix C. Transportation Plan Appendix D. Air Quality Impact Analysis

*Appendices E through I provided in a separate document.

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APPENDIX A

Figures, Maps, and Tables

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FIGURES

Figure A-1. Preliminary Layout of Proposed TGU Federal 1090 #30 Well Pad Figure A-2. Preliminary Layout Proposed SPU Federal 1190 #20 Well Pad Figure A-3. Preliminary Layout Proposed SPU Federal 1190 #29 Well Pad Figure A-4. Preliminary Layout Proposed DGU 1289 #20-23 Well Pad Figure A-5. Layout Existing IPU 1291 #13-24 Well Pad

1 Figure A-1. Preliminary Layout of Proposed TGU Federal 1090 #30 Well Pad

2 Figure A-2. Preliminary Layout Proposed SPU Federal 1190 #20 Well Pad

3 Figure A-3. Preliminary Layout Proposed SPU Federal 1190 #29 Well Pad

4 Figure A-4. Preliminary Layout Proposed DGU 1289 #20-23 Well Pad

5 Figure A-5. Layout Existing IPU 1291 #13-24 Well Pad

MAPS

Map A-1 Proposed Action Map A-2. Proposed Action and Previously Approved GELLC Projects Map A-3. Surface Freshwater Pipeline Route Map A-4. Detailed Location of Proposed TGU Federal 1090 #30 Well Pad Map A-5. Detailed Location of Proposed SPU Federal 1190 #20 Well Pad Map A-6. Detailed Location of Proposed SPU Federal 1190 #29 Well Pad Map A-7. Detailed Location of Proposed DGU 1289 #20-23 Well Pad Map A-8. Detailed Location of Existing IPU 1291 #13-24 Well Pad Map A-9. Water Supply and Storage Map A-10. Geology Map A-11. Range Improvements Map A-12. Proposed Yellow-billed Cuckoo Critical Habitat along Proposed Haul Routes Map A-13. Hydrologic Units Map A-14. Proposed SPU Federal 1190 #20 Water-Related Features Map A-15. Pitkin Mesa Public Water Systems and State of Colorado Rule 317B Buffer Areas in the NFMMDP Project Vicinity Map A-16. Big Game Habitats Map A-17. Cumulative Effects

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TABLES

Table A-1. GELLC Existing and Approved Development Table A-2. Detail of Proposed Disturbance for Project Components Table A-3. Project Well pads and Attached Stipulations Table A-4. Estimated Workforce for a Single Well Table A-5. Estimated Geologic Formation Tops for Shale Gas Development Table A-6. Grazing Allotments Coinciding with the Project Area Table A-7. State-Listed Noxious Weeds Observed in the Project Area Table A-8. Noise Levels at Typical Construction Sites and Along Access Roads Table A-9. Existing BLM Realty Authorizations in the NFMMDP Project Area Table A-10. Existing Forest Service Realty Authorizations in the NFMMDP Project Area Table A-11. Soil Types and Characteristics Affected by the Proposed Action Table A-12. Soil Types and Effects from Proposed Action Table A-13. UFO Sensitive Species with Potential for Occurrence in the Project Area Table A-14. Vegetation Types Affected by Proposed Action Table A-15. Designated Water Uses for Selected Streams in the NFMMDP Project Vicinity Table A-16. Constituents of Typical Hydraulic Fracturing Operations Table A-17. Past, Present and Reasonably Foreseeable Future Actions Table A-18. BLM Interdisciplinary Team Authors and Reviewers

Table A-1. GELLC Existing and Approved Development

Project Component Unit Year Constructed and Status 1,2 NEPA Approval Federal 1090-31 1977 – one producing gas well Federal 1090 #33 1977 – one producing gas well Federal 16-4 1981 – one producing gas well Approved by Forest Trail Gulch Federal 1090 #30-4 1981– one producing gas well Service Federal 1090-32 1983 – one producing gas well Federal 21-7 1993 – one shut-in gas well Approved by Forest Federal 1190 #17 1976 – one shut-in gas well Service 1977 – one plugged and abandoned Federal 1190 #7 Unknown gas well (pad only) Jacobs 1290 #6-32 2007 – one shut-in gas well No NEPA (Private) Spadafora #20-21 Sheep Park II 2016 – one producing shale well One approved gas well (pad not CO-S050-2015-0029-EA Henderson #8-14 constructed) Spadafora 11-90-20-H1 Categorical Exclusion – Well Alternate Access Approved – not constructed Forest Service Road July 2017 Lone Pine #1A 2004 – one shut-in coal seam well Allen #12-24 2005 – one producing coal seam well Allen 1291 #12-13D or Iron Point 2007 – one shut-in water disposal well No NEPA (Private) Allen 12-12-WDW 2011 – one producing shale well, one IPU 1291 #13-24 shut-in coal seam well 2005 – one shut-in coal seam well, Hotchkiss Federal 17-13 CO-150-2005-45-EA one APD pending drilling 2006 – one producing coal seam well, DGU Federal 1289 #18-43 one shut-in coal well, and one APD pending drilling CO-150-2006-022-EA Hotchkiss Federal 20-12D 2006 – one producing shale well Hotchkiss Federal 18-31 Deadman 2006 – one producing coal seam well CO-150-2006-022-EA Hotchkiss 1289 #18-22D Gulch 2006 – one active water disposal well 2009 – one producing shale well; two Hotchkiss Federal 17-11 CO-150-2008-35-EA APDs pending drilling 2014 – two producing shale wells; two DOI-BLM-CO-S050- Hotchkiss #18 Pad coal seam wells awaiting completion 2014-009 CX (390) Hotchkiss Water Storage 2010 – Active No NEPA (Private) Facility Hotchkiss 1290 #1-34 Non-Unit 2006 – one shut-in coal seam well No NEPA (Private) Sheep Gas Gathering EA, Paonia Ranger Various Constructed 2008 and 2009 System (also water line) District, June 2007 Categorical Exclusion – Sheep-Bull Connector Non-Unit Approved – not constructed Forest Service, Oct 2010 1 Includes sandstone gas wells (conventional wells), coal-seam wells, and marine shale wells. Section 4 of the EA describes oil and gas development by other operators in the project area and vicinity. 2 Wells are sandstone wells except where identified as shale wells or coal seam wells.

Table A-2. Detail of Proposed Disturbance for Project Components Number or Initial Long-term Surface Well Pad Length (feet) Disturbance Acres Disturbance Acres Ownership (Federal/Private) (Federal/Private) (Federal/Private) WELL PADS TGU Federal 1090 #30 Federal 1/0 5.60/0.00 1.43/0.00 SPU Federal 1190 #20 Federal 1/0 6.62/0.00 1.27/0.00 SPU Federal 1190 #29 Federal 1/0 8.97/0.00 1.25/0.00 DGU 1289 #20-23 Private 0/1 0.00/5.66 0.00/1.12 IPU 1291 #13-24 Private 0/1 0.00/0.00 0.00/0.00 Subtotal (Federal/Private) 3/2 21.19/5.66 3.95/1.12 ACCESS ROADS 1 TGU Federal 1090 #30 Federal 883/0 0.61/0.00 0.49/0.00 road reroute SPU Federal 1190 #20 Federal 12,057/0 2 8.30/0.00 3 6.64/0.00 3 SPU Federal 1190 #29 Federal 5,545/0 3.82/0.00 3.06/0.00 DGU 1289 #20-23 Federal/Private 608/3,166 4 0.42/2.18 0.33/1.74 IPU 1291 #13-24 Private 0/0 0.00/0.00 0.00/0.00 Subtotal (Federal/Private) 19,093/3,166 13.15/2.18 10.52/1.74 GATHERING LINES 5 TGU Federal 1090 #30 Federal 414/0 0.28/0.00 0.00/0.00 SPU Federal 1190 #20 Federal 870 6/0 0.60/0.00 0.00/0.00 SPU Federal 1190 #29 Federal 208/0 0.14/0.00 0.00/0.00 DGU 1289 #20-23 Federal/Private 573/3,454 7 0.39/2.38 0.00/0.00 IPU 1291 #13-24 Private 0.00/0.00 0.00/0.00 0.00/0.00 Subtotal (Federal/Private) 2,065/3,454 1.41/2.38 0.00/0.00 35.75/10.22 Total (Federal/Private) 14.47/2.86 [17.33] [45.97] 1 Access road width is 30 feet for initial disturbance and 24 feet for long-term disturbance (14 feet plus ditches). 2 Length is for Option 2 (Map 2), including 12,057 feet on National Forest System lands, which 2,348 feet would be outside the SPU. Length for Option 1 includes 3,251 feet (92 feet on National Forest System lands and 3,159 feet on private lands). 3 Under Option 1, initial disturbance would be 2.24 acres (0.06 acre on National Forest System lands and 2.18 acres on private lands) and long-term disturbance would be 1.79 acres (0.05 acre on National Forest System lands and 1.74 acres on private lands). 4 Includes 608 feet on BLM land and 3,166 feet on private land; access road and gathering line are collocated. 5 Gathering line width is 30 feet for initial disturbance, to be reclaimed promptly. 6 Includes 835 feet for reroute of Sheep Gas Gathering and 35 feet for connection to Sheep Gas Gathering. 7 Includes 573 feet on BLM land and 3,454 feet on private land; access road and gathering line are collocated.

Table A-3. Project Well Pads and Attached Stipulations 1

Surface Bottomhole Well Pad/ Unit/ Ownership/ Federal Lease Stipulations Location Lease/Date Leases COC13600: No occupancy of the surface of the following areas is authorized by this lease. The lessee is, however, authorized to employ directional drilling to develop the mineral resources under these areas, provided that such drilling or other works will not disturb the surface area or otherwise interfere with their use by the Forest Service. It is understood and agreed that the use of these areas for National Forest purposes is superior to any other use. Areas to be excluded from direct drilling occupancy are: TGU Federal 1090 1) Within 500 feet on either side of the centerline of roads #30 (Expanded Forest and/or highways within the lease areas. Does not COC136002 Pad) Service apply to relocated road. COC13601 Trail Gulch Unit COC13600 2) Within 200 feet on either side of the centerline of trails COC13602 T10S, R90W 11/1/1971 within the lease area. Sec. 30, SWSE 3) Within 500 feet of the normal high water mark of lakes, ponds, and reservoirs within the lease area. 4) Within 500 feet of the normal high water mark of streams within the lease area. 5) Within 400 feet of springs within the lease area. 6) Within 400 feet of any improvements owned, permitted, leased, or otherwise authorized by the Forest Service. The distances indicated in items 1 through 4 may be reduced when agreed to in the operating plan. COC13483: No occupancy of the surface of the following areas is authorized by this lease. The lessee is, however, authorized to employ directional drilling to develop the mineral resources under these areas, provided that such drilling or other works will not disturb the surface area or otherwise interfere with their use by the Forest Service. It is understood and agreed that the use of these areas for National Forest purposes is superior to any other use. Areas to be excluded from direct drilling occupancy are: SPU Federal 1190 1) Within 500 feet on either side of the centerline of roads Forest #20 (New Pad) and/or highways within the lease areas. Service Sheep Park II Unit COC700042 2) Within 200 feet on either side of the centerline of trails COC13483 within the lease area. T11S, R90W 11/1/1971 Sec. 20, NESE 3) Within 500 feet of the ordinary high water mark of lakes, ponds, and reservoirs within the lease area. 4) Within 500 feet of the ordinary high water mark of streams within the lease area. 5) Within 400 feet of springs within the lease area. 6) Within 400 feet of any improvements owned, permitted, leased, or otherwise authorized by the Forest Service. The distances indicated in items 1 through 4 may be reduced when agreed to in the operating plan.

Surface Bottomhole Well Pad/ Unit/ Ownership/ Federal Lease Stipulations Location Lease/Date Leases COC70004: No Surface Occupancy for slopes greater than 60%, high geologic hazard, and wetlands, floodplains, and SPU Federal 1190 riparian areas. Forest #29 (New Pad) Controlled Surface Use for slopes 40% to 60%, moderate Service COC70004 Sheep Park II Unit geologic hazard, and elk winter habitat. COC70004 COC69066 No surface use is allowed from December 1 through April T11S, R90W 6/1/2007 Sec. 29, SWSE 30, for the purpose of protecting critical elk winter ranges. This stipulation does not apply to operation and maintenance of production facilities. Surface location overlies Fee lease; Federal lease DGU 1289 #20-23 COC65106 stipulations are not applicable. Operator abides by Deadman Gulch COC65107 executed Surface Use Agreement with private landowner, Unit Fee COC65108 subject to BLM COAs relative to Federal resources. A T12S, R89W COC68350 small segment of the access road crosses a lease with a big Sec. 20, NESW COC64169 game timing limitation. IPU 1291 #13-24 (Existing Pad) COC65112 Surface location overlies Fee lease; Federal lease COC65113 stipulations are not applicable. Operator abides by Iron Point Unit Fee COC65120 executed Surface Use Agreement with private landowner, T12S, R91W COC65534 subject to BLM COAs relative to Federal resources. Sec. 13, SWSE

1 Regulations related to the Forest Service consideration of requests to modify, waive, or grant exceptions to lease stipulations are cited in 36 CFR § 228.104, and are also contained in BLM regulations in 43 CFR § 3100. 2 These leases pre-date the National Forest Management Act and the Forest Plan. They were issued by the U.S. Geological Survey with standard lease stipulations for the protection of surface resources.

Table A-4. Estimated Workforce for a Single Well Number of Project Phase and Workforce Category Workers Well Pad, Road, and Gathering Line Construction 71 Rig Mobilization and Demobilization 30 Drilling 36 2 Sand Delivery 4 3 Water Delivery 7 3 Well Completion 35 4,5 Interim Reclamation 2 Dust Control 1 6 Development Total 122 Pumper 4 Maintenance 3 7 Operations Total 7 1 Includes one bulldozer operator, one blade operator, one track hoe operator, one welder, one two-man gathering line crew, and one supervisor. 2 Based on two drilling shifts per day, with 18 drilling workers per shift. Includes 10 days for drill rig mobilization and demobilization. 3 Assumes sand and water deliveries occur during daylight hours for 10 days during well completion. 4 Includes 20 days for rig and hydraulic fracturing tank mobilization and demobilization and 14 days for hydraulic fracturing.

Number of Project Phase and Workforce Category Workers 5 Includes one completion shift per day. 6 Assumes that road dust is controlled during well pad construction, drilling, completion, and interim reclamation on an as-needed basis between June and September. 7 Includes two 5-day maintenance periods per year.

Table A-5. Estimated Geologic Formation Tops for Shale Gas Development

Formation/Group Depth of Top Type of Material Alluvium 0 Sand, gravel, and cobble Wasatch Surface Shale, siltstones, and lenticular sandstones Ohio Creek 2,037 Buff sandstone Mesaverde 2,135 Sandstone, siltstone, and coal Rollins 4,972 Sandstone Cozzette 5,596 Sandstone Corcoran 5,734 Sandstone Mancos 5,793 Marine shale, confining layer Niobrara 8,651 Marine shale

Table A-6. Grazing Allotments Coinciding with the Project Area

Total Portion in Allotment AUMs in Allotment Name Allotment Project Area Period of Use Number Project Area Area (acres) (acres) Condemn It Park 00876 9,326 4,229 6/5-9/20 487 Henderson-West Muddy 00806 16,615 7,192 6/16-10/15 1,067 Hotchkiss 00868 15,282 2,360 6/21-10/15 146 Huntsman 00871 25,167 913 5/20-9/10 41 Little Muddy S&G 00873 14,581 672 6/5-9/20 41 Sheep Park 00878 7,613 5,276 6/21-9/20 576 Trail Gulch S&G 00882 8,320 4,464 6/20-9/23 552

Table A-7. State-Listed Noxious Weeds Observed in the Project Area

Common Name Area County Colorado Occurrence (Scientific Name) Lists Designation Bull thistle Proposed disturbance area on north end of SPU G 1 B List (Cirsium vulgare) Federal 1190 #20 access road. Proposed disturbance area on SPU Federal 1190 Canada thistle G, DCC 2 B List #20 access road; proposed disturbance for SPU (Cirsium arvense) Federal 1190 #29 well pad. Cheatgrass Minor amounts in previously disturbed areas near -- C List (Bromus tectorum) TGU Federal 1090 #30.

Common Name Area County Colorado Occurrence (Scientific Name) Lists Designation Widespread throughout the project area in low Common mullein densities; higher densities along roadsides and G C List (Verbascum thapsus) pipeline corridors near SPU Federal 1190 #20 and #29 and around TGU Federal 1090 #30. Widespread throughout the project area in low Hounds-tongue densities; higher densities in and around SPU (Cynoglossum G, DCC B List Federal #20 and #29 and around TGU Federal officinale) 1090 #30. Widespread throughout the project area in low Musk thistle densities; higher densities on proposed disturbance G, DCC B List (Carduus nutans) area for Option 2 access road to SPU Federal 1190 #20 and DGU 1289 #20-23. Widespread throughout the project area in low Plumeless thistle densities; higher densities in and around SPU G B List (Carduus acanthoides) Federal 1190 #20 and #29 and around TGU Federal 1090 #30. Source: MountainWest 2017a. G = Gunnison County Weed List. DCC = Delta County Containment and Control List.

Table A-8. Noise Levels at Typical Construction Sites and Along Access Roads

Noise Level (dBA) Zone 50 feet 350 feet 1,000 feet Air Compressor, Concrete Pump 82 65 56 Backhoe 85 68 59 Bulldozer 89 72 63 Crane 88 71 62 Front End Loader 83 66 57 Heavy Truck 88 71 62 Motor Grader 85 68 59 Road Scraper 87 70 61 Tractor, Vibrator/Roller 80 63 54 Source: BLM 1999; La Plata County 2002.

Table A-9. Existing BLM Realty Authorizations in the NFMMDP Project Area

Serial Case Owner Name Feature Location Number Disposition T10S, R90W Sec. 18, 19, Divide Creek Gathering COC68438 Oil and Gas Pipeline 29, 30, 32, 33 Authorized System T11S, R90W Sec. 3, 4, 10 Divide Creek Gathering COC6843801 Water Facility Same as pipeline Authorized System COC68438T Divide Creek Gathering Temporary Use Permit Same as pipeline Authorized

Serial Case Owner Name Feature Location Number Disposition System COC55076 Spadafora Ranches FLPMA Easement T11S, R90W, Section 22 Authorized CO Department of Highway – Federal Aid COC26960 T12S, R89W, Section 20 Authorized Transportation Project COC42644 Hotchkiss Ranches Road T12S, R89W, Section 20 Authorized COC75551 Gunnison Energy Access Road T12S, R89W, Section 20 Authorized Forest Service FLPMA COC77552 Bar-K Ranch T12S, R90W, Section 3 Authorized Easement Forest Service FLPMA COC77554 Bar-K Ranch T12S, R90W, Section 3, 4 Authorized Easement Forest Service FLPMA COC77745 Hotchkiss Ranches T12S, R90W, Section 24 Authorized Easement

Table A-10. Existing Forest Service Realty Authorizations in the NFMMDP Project Area

Action Land Authorization Case Name Feature Location Date Ownership Forest 329594010667 1924 Harry Brown Road T11S, R90W, Section 10 Service Private Road Forest 329361010667 1994 William Bird T10S, R90W, Section 30 FLPMA Easement Service Trail (vehicle – all 329628010667 1969 Claire Hotchkiss T12S, R91W, Section 13 Private types)(Route No. 503) Trail (vehicle – all 329588010667 1968 J.M. Beal T12S, R91W, Section 11 Private types)(Route No. 503) Trail (vehicle – all 329586010667 1969 P.B. Allen T12S, R91W, Section 11 Private types)(Route No. 503) Forest COC56442 1994 Forest Service FLPMA Easement T10S, R90W, Section 30 Service T10S, R90W, Section 28 Forest COC59417 1996 Forest Service FLPMA Easement and 33 Service

Table A-11. Soil Types and Characteristics Affected by the Proposed Action

Soil Type Description Erosion Potential Found on fans, mountains, and small valleys. Parent material is Mapping Unit 36 valley filling alluvium derived from sedimentary rock. It is Fluvents, Flooded characterized as a deep, well-drained, clay loam/sandy loam. Soil Slight to Moderate (0 to 5% slopes) is frequently flooded. Depth to a water table is 24 inches. Compaction/rutting hazard is severe. Derived from old alluvium and/or complex landslide deposits Mapping Unit 38 derived from sedimentary rock. It is characterized as a deep clay Fughes loam Moderate to high loam. Shrink-swell potential is high. Erosion hazard is moderate (15 to 25% slopes) to high. Mapping Unit 41 Occurs in depressions, swales, and drainageways. Derived from High Fughes-Curecanti old alluvium, glacial outwash, and/or complex landslide deposits,

Soil Type Description Erosion Potential stony loams and glaciofluvial deposits derived from igneous and metamorphic (10 to 40% slopes) rock. It is characterized as a deep clay/brushy/stony loam. Soil is well-drained. Shrink-swell potential is moderate. Mapping Unit 75 This soil type occurs on mountain flanks, foot slopes, backslopes, Torriorthents-Rock and free faces, and is a very stony loam or unweathered bedrock. outcrop, sandstone, Moderate to high The soil is derived from stony loamy rockfall deposits. Soil is complex well-drained. Shrink-swell potential is low. (40 to 65 % slopes) Occurs in mountainous areas, and is considered a mountain/deep Mapping Unit 158 clay loam and brushy loam. Parent material consists of Herm-Fughes-Kolob interbedded alluvium derived from sandstone and shale, and/or Moderate to high complex interbedded residuum weathered from sandstone and shale. Soils (25 to 40% slopes) are well-drained. Shrink-swell potential is moderate to high. This soil type occurs in alluvial fans, valley floors, and at the toe- of-slopes, and is considered a mountain loam/clay loam. Its Mapping Unit 195 parent material is interbedded alluvium derived from sandstone Weed-Herm complex Moderate and shale, and/or interbedded residuum weathered from sandstone (0 to 25% slopes) and shale. Drainage class is well-drained. Shrink-swell potential is moderate. Occurs on mountain slopes. Derived from interbedded colluvium Mapping Unit 200 derived from sandstone and shale and/or interbedded residuum Wetopa-Wesdy weathered from sandstone and shale. It is characterized as a deep Moderate complex well-drained clay loam/very cobbly clay. Depth to a restrictive (5 to 65% slopes) layer is more than 60 inches. Soil rutting hazard is severe. Shrink-swell potential is moderate. Source: NRCS 2017.

Table A-12. Soil Types and Effects from Proposed Action

Initial Disturbance Soil Type Percent (acres Mapping Unit 158, Herm-Fughes-Kolob complex (25 to 40% slopes) TGU Federal 1090 #30 0.58 1.3 SPU Federal 1190 #20 6.01 13.0 SPU Federal 1190 #29 7.74 16.8 Subtotal 14.33 31.1 Mapping Unit 195, Weed-Herm complex (0 to 25% slopes) TGU Federal 1090 #30 5.91 12.8 SPU Federal 1190 #20 7.48 16.2 SPU Federal 1190 #29 2.88 6.2 Subtotal 16.27 35.2 Mapping Unit 200, Wetopa-Wesdy complex (5 to 65% slopes) SPU Federal 1190 #20 2.21 4.8 SPU Federal 1190 #29 2.31 5.0 Subtotal 4.52 9.8

Initial Disturbance Soil Type Percent (acres Mapping Unit 36, Fluvents, Flooded (0 to 5% slopes) DGU 1291 #20-23 0.95 2.1 Subtotal 0.95 2.1 Mapping Unit 38, Fughes loam (15 to 25% slopes) DGU 1291 #20-23 6.44 13.9 Subtotal 6.44 13.9 Mapping Unit 41, Fughes-Curecanti stony loams (10 to 40% slopes) DGU 1291 #20-23 0.54 1.2 Subtotal 0.54 1.2 Mapping Unit 75, Torriorthents-Rock outcrop, sandstone, complex (40 to 65 % slopes) DGU 1291 #20-23 3.10 6.7 Subtotal 3.10 6.7

Table A-13. BLM-UFO Sensitive Species with Potential for Occurrence in the Project Area 1

Species Habitat Association and Use Potential for Occurrence Mammals Forages from desert shrublands to coniferous Possible, suitable foraging and Spotted bat forests, roosts in larger trees and cliffs. roosting habitat throughout project (Euderma maculatum) Migrates for winter. area Widespread across shrublands and montane Possible; suitable foraging and Townsend’s big-eared bat forests. Requires caves, mines, or structures roosting habitat throughout project (Corynorhinus townsendii) for roosting and hibernating. area Roosts in montane and foothills conifers and oakbrush; may forage to as low as Possible, suitable foraging and Fringed myotis greasewood and saltbush shrublands. Roosts roosting habitat throughout project (Myotis thysanodes) and hibernates in caves, mines, and area buildings. Birds Possible; larger suitable Nests and forages in upper montane and nesting/foraging habitat in Northern goshawk subalpine conifers and aspen. Often winters aspen/conifer stands near DGU (Accipiter gentilis) in lower lower montane or foothills conifers, and IPU pads; nearest nesting including pinyon-juniper woodlands. territory is 3.6 miles from project Nests on cliffs or rocky bluffs and forages Golden eagle Present; observed flying in project across deserts, grasslands, and low (Aquila chrysaetos) area shrublands to as high as the alpine zone. Nests near streams, rivers, and lakes with Present; mapped winter range in Bald eagle mature cottonwoods; uses winter roosts in vicinity of project; closest nest 2 (Haliaeetus leucocephalus) areas with relatively ice-free conditions. miles from project near CR 265 Feeds primarily on fish. Nests on high cliffs; forages for waterfowl Unlikely; no cliff-nesting sites or American peregrine falcon on large rivers or reservoirs, and sometimes large waterbodies in project (Falco peregrinus anatum) for grouse in open country. Absent in vicinity winter.

Species Habitat Association and Use Potential for Occurrence Nests and forages in sagebrush shrublands, Present; suitable nesting and Brewer’s sparrow mostly no higher than the montane. May foraging habitat limited in project (Spizella breweri) also occur in low willows in the upper area; observed in project area subalpine or lower alpine. Absent in winter. Amphibians Breeds in grassy wetlands or margins of Present; observed in larger Northern leopard frog clear ponds and clear, slow-flowing streams wetlands and stock ponds in (Lithobates pipiens) to as high as the montane. project area Fish Found in shallows of larger rivers and in Bluehead sucker Present; observed in Hubbard and smaller streams with a rock substrate and (Catostomus discobolus) West Muddy Creeks mid- to fast-moving waters. Mostly in larger rivers but moves into Flannelmouth sucker Present; observed in Hubbard smaller tributaries. Uses a variety of flow (Catostomus latipinnis) Creek regimes (runs, riffles, eddies, backwaters). Occurs in slow-moving waters adjacent to Unlikely; expected in streams in Roundtail chub fast waters in large rivers at lower elevations project area but in downstream (Gila robusta) to as high as the montane. Occurs in reaches Gunnison and Colorado rivers. “Blue Lineage” Colorado Limited to clear, cool montane streams River cutthroat trout Unlikely; no documentation in isolated from other subspecies or strains (Oncorhynchus clarkii cf. vicinity of project area cutthroat trout and from rainbow trout. pleuriticus) 2 1 USFS-GMUG Sensitive Species are addressed in Appendix F, Biological Evaluation and Management Indicator Species (BE-MIS) Report. 2 Blue Lineage = Relict populations of Colorado River cutthroat trout indigenous to the Green, Yampa, and White River Basins. Currently treated as sensitive by BLM/Forest Service pending further evaluation of ecological and taxonomic status.

Table A-14. Vegetation Types Affected by Proposed Action

Disturbance (acres) Vegetation Type TGU 1090 #30 SPU 1190 #20 SPU 1190 #29 DGU 1289 #20-23 Total Aspen Woodlands 0.20 2.99 1.87 1.92 6.98 Douglas-fir 0.01 0.19 -- 0.29 0.49 Woodlands Currently Disturbed 0.19 -- -- 0.40 0.59 Irrigated Hay Field ------5.55 5.55 Mixed Mountain 1.57 7.84 4.85 1.48 15.74 Shrubland Montane Meadows 3.79 2.21 0.24 -- 6.24 Oakbrush Shrublands 0.73 2.47 5.97 0.17 9.34 Pinyon Juniper ------0.70 0.70 Riparian and Wetland ------0.52 0.52 Areas Total 6.49 15.70 12.93 11.03 45.97

Table A-15. Designated Water Uses for Selected Streams in the NFMMDP Project Vicinity

Stream Segment/Federal Unit Designated Uses 1, 2 Current Conditions COGUNF04a – Tributaries and wetlands to Muddy Creek within national forest Agriculture boundaries. All tributaries to Class 1 Coldwater Aquatic Life Current conditions fully support these uses. the North Fork Gunnison from Recreation Class E its inception to its confluence Water Supply with the Gunnison River within national forest boundaries Current conditions mostly support those COGUNF04b – Muddy Creek, uses. Exceptions are East Muddy Creek for including all tributaries and Agriculture coldwater aquatic life (iron) and water wetlands, from the national Class 1 Coldwater Aquatic Life supply (arsenic); and a segment of Muddy forest boundary to the Recreation Class E Creek for coldwater aquatic life (iron and confluence with Anthracite Water Supply temperature), water supply (iron and Creek arsenic), and recreation (coliform bacteria). Agriculture Paonia Reservoir is on Colorado’s COGUNF07 – Paonia Class 1 Coldwater Aquatic Life Monitoring and Evaluation list for Reservoir and Overland Dam Recreation Class E dissolved zinc with regard to aquatic life. Water Supply COGUNF02 – Mainstem North Agriculture Fork Gunnison from its Class 1 Coldwater Aquatic Life inception to above the Black Current conditions fully support these uses. Recreation Class E Bridge (41.75 Drive) above Water Supply Paonia COGUNF05a – Mainstems of Hubbard Creek, Terror Creek, Agriculture and Minnesota Creek, from the Class 1 Coldwater Aquatic Life Current conditions fully support these uses. national forest boundary to Recreation Class E their confluences with the Water Supply North Fork Gunnison River 1 Recreation Class E = Existing primary contact use (swimming, boating, waterskiing), April through September. 2 Recreation Class P = Potential primary contact use, October through March.

Table A-16. Constituents of Typical Hydraulic Fracturing Operations Additive % by Common Use of Example Typical Example 1 Function 1 Type 1 Volume 2 Compound Dissolves mineral cement Swimming pool chemical and Acid Hydrochloric acid 0.123 in rocks and initiates cleaner cracks. Eliminates bacteria that produce Disinfectant; sterilizer for Biocide Glutaraldehyde 0.001 corrosive/poisonous by- medical and dental equipment products. Hair coloring, as a disinfectant, Ammonium Allows delayed breakdown Breaker 0.010 and in manufacture of household persulfate of the gel. plastics Creates a brine carrier fluid Low-sodium table salt Clay that prohibits fluid Potassium chloride 0.060 substitutes, medicines, and IV stabilizer interaction with formation fluids clays.

Additive % by Common Use of Example Typical Example 1 Function 1 Type 1 Volume 2 Compound Preservative in livestock feed; Corrosion Prevents corrosion of well Formic acid 0.002 lime remover in toilet bowl inhibitor casing. cleaners Maintains fluid viscosity as Laundry detergents, hand soaps, Crosslinker Borate salts 0.007 temperature increases. and cosmetics Friction “Slicks” the water to Flocculent in water treatment and Polyacrylamide 0.088 reducer minimize friction. manufacture of paper Thickens water to help Gelling Thickener, binder, or stabilizer in Guar gum 0.056 suspend the sand propping agent foods agent. Prevents precipitation of Flavoring agent or preservative in Iron control Citric acid 0.004 metal oxides. foods Increases viscosity of the Soaps, shampoos, detergents, and Surfactant Lauryl sulfate 0.085 fluid. foaming agents Sodium hydroxide used in soaps, pH Adjusts pH of fluid to Sodium hydroxide, drain cleaners; acetic acid used as adjusting 0.011 maintain effectiveness of acetic acid chemical reagent, main agent other components. ingredient of vinegar Scale Sodium Prevents scale deposits in Dishwashing liquids and other 0.043 inhibitor polycarboxylate the pipe. cleaners Added as necessary as Winterizing Ethanol, isopropyl Various cosmetic, medicinal, and -- stabilizer, drier, and anti- agent alcohol, methanol industrial uses freezing agent. Total Additives 0.49 Total Water and Sand 99.51 1 Ground Water Protection Council and the Interstate Oil and Gas Compact Commission 2017. 2 U.S. Department of Energy (DOE) 2009.

Table A-17. Chemicals Potentially Used in GELLC Oil and Gas Operations

Chemical Abstract Chemical Purpose Number (CAS) Barite - Barium Sulfate and crystalline 7727-43-7 Weighting Agent silica, quartz 14808-60-7 000067-56-1 000067-63-0 Cl-31 Corrosion Inhibitor 000064-18-6 000100-44-7 67-48-1 ClayCare - Choline Chloride and water Potassium Chloride Substitute 7732-18-5 Defoamer 530 - Propane-1,2-diol Water Additive, Antifoam 25322-69-4 propoxylated DWP-621-1 - Anionic water-soluble Friction Reducer CAS Not Provided polymer Quatemized Potassium Chloride DPW913-1- CAS Not Provided Substitute 25322-68-3 DWP-944-3 Biocide 10222-01-2 Detergent – Reduces Surface Tension DynaDet CAS Not Provided and Stabilizes Emulsification

Chemical Abstract Chemical Purpose Number (CAS) EvoCon II Surfactant CAS Proprietary Drilling Performance Evolube OPE II CAS Proprietary Enhancer EvoMod Viscosifier CAS Not Provided Synthetic inorganic polymer 7727-43-7 1332-58-7 ExWATE - Barium Sulfate Density Increaser 14808-60-7 471-34-1 FERROTROL 300L - Citric acid Iron Control 77-92-9 FlexFirm KA - Anhydrous Potassium 1312-76-1 Shale Inhibitor Silicate powder 14808-60-7 15619-48-4 HAI-40M Corrosion Inhibitor 67-56-1 67-63-0 Hydrochloric Acid Performance Enhancer 7647-01-0 HR-601 (Lignosulfonate) Cement Retarder CAS Not Provided 64-17-5 64742-94-5 LoSurf-3000 Surfactant 91-20-3 95-63-6 127087-87-0 Methyl alcohol Hydrate Inhibitor 67-56-1 NEWCARB - Calcium Carbonate Lost Circulation Material 471-34-1 NEWPAC B - Cellulose Filtration Control CAS Not Provided NewPhalt - Sulfonated asphalt Shale Stabilizer CAS Proprietary NewPHPA D - Anionic water-soluble CAS Not Shale control polymer Provided NEWZAN D - Xartnar Gum Viscosifier 11135-66-2 NoFoam X Defoamer CAS Proprietary PHENO SEAL - Melamine and phenolic Lost Circulation Reducer CAS Not Provided resins Potassium Chloride - Inorganic salt Shale Stabilizer 7447-40-7 SAPP - Sodium acid Pyrophosphate Sequestering Agent 7758-16-9 Caustic Soda - Caustic Soda Anhydrous Temperature Stability Extender CAS Not Provided

Table A-18. Past, Present, and Reasonably Foreseeable Future Actions (RFAA)

Resource Projects Timing

The area near Telluride is in the Telluride PM10 maintenance area. The area is currently in compliance with all applicable NAAQS. For as long as the area remains in maintenance, the BLM will analyze any authorized activities Air Quality in accordance with the provisions of the General Conformity Rule and Climate Past, Present document any findings in the applicable authorizing NEPA document. Change Increased concern over greenhouse gas emissions and global warming issues may lead to future Federal and state regulations limiting emissions of pollutants.

Resource Projects Timing Past, present, and future actions with the potential for cumulative effects to soil resources in the project area include existing and future oil and gas development, timber sales, livestock grazing, public use of trails and roads, Soils and wildfires. Erosion control measures and reclamation are required for Past, Present most of these activities to reduce direct, indirect, and cumulative soils effects. The cumulative effects to soils vary depending on the location and amount of disturbance and the sensitivity of specific soil types to erosion. The area has been and will continue to be affected by irrigation and drinking water diversions. Reservoir operations have affected water supply, aquatic Water: conditions, and timing. Irrigation rights are expected to continue being Ditches and bought and sold in the future, with some new property owners informally Past, Present Canals changing how the right was historically used. Due to population growth and land sales, more agricultural water rights may be converted to municipal and industrial uses. Forestry. Past, current, and foreseeable forestry uses in the CEAA include personal and commercial harvest of fuel wood, poles and posts for fence building, wildings (live trees and shrubs), and Christmas trees. Vegetation treatments. Prescribed fire and mechanical treatments of vegetation (e.g., chaining, roller-chopping, harrowing, drill seeding, hydro- Vegetation Past, Present, axing, and brush mowing) were common in the past on public and private Management RFFA rangelands in the CEAA. With the exception of chaining, these treatments still occur and are likely to continue. Hazardous fuels reduction. Fuels treatments, including prescribed fires, chemical and mechanical treatment, and seeding, are expected to continue and potentially increase in the future. Several years of drought in western states have resulted in severe stress on pine trees. This stress has made the trees less able to resist attacks by insects Drought and such as mountain pine beetles. Mountain pine beetle outbreaks occur Insect-borne Past, Present periodically in Colorado, and some pinyon pine stands in the CEAA have Diseases experienced mortality from the Ips beetle. Sudden Aspen Decline has also affected parts of the CEAA. The BLM manages 240 grazing allotments with 165 grazing permittees. Historically, several areas sustained high levels of both sheep and cattle grazing. Seasonal cattle grazing still occurs, to a lesser degree, from approximately June through September. The Forest Service prepared an EA in 2005 for the Muddy Creek basin (also known as Muddy country). On Livestock National Forest System lands surrounding the project area, there are 11 Past, Present, Grazing allotments with multiple permittees. RFFA This resource is affected primarily by surface disturbance of forage habitat for livestock. Existing coal mines, and increasing oil and gas development, and planting of crops have resulted in loss of grass/forb communities, which have become a limiting factor for grazing. Road construction has occurred in association with timber harvesting, historic vegetation treatments, energy development, and mining on BLM- administered lands, private lands, State of Colorado lands, and National Access and Past, Present, Forest System lands. The bulk of new road building is occurring for Transportation RFFA community expansion and energy development. Road construction is expected to continue at the current rate on BLM and National Forest System lands; the future rate is unknown on private and State of Colorado lands. Colorado Department of Transportation: Activities on SH 133 include annual Past, Present, snow maintenance and emergency response actions. RFFA Lands and Colorado Department of Transportation is working on highway improvement Realty projects on SH 92 from Hotchkiss to Delta and U.S. Highway 50 in the Blue Present Mesa Lake area; both of these projects are likely to continue for the next

Resource Projects Timing several years. Several gravel pits have also been approved in the past 5 years; however, Past, Present most are within just a few miles of the city of Delta, Colorado. Residential developments in the area around the communities of Paonia, Hotchkiss, Crawford, and Delta have been growing in population, with many new houses being built. Most of this development has been down-valley Past, Present, from the coal mines in broader portions of the North Fork Valley. This RFFA development has increased the traffic load and demand for maintenance on SH 133. Natural gas pipelines: Bull Mountain Gathering line; Ragged Mountain Gathering; Sheep Gas Gathering System; Henderson Lateral pipeline; Aspen Leaf trunk pipeline; Hotchkiss Ranches Gas Gathering System, Vessels Past, Present Oxbow facility connection line from Bore hole 1; local utility service pipelines Sheep-Bull connector natural gas pipeline. A pipeline in which GELLC conveys produced gas from the Sheep Gas Gathering System to the SG Bull Mountain Pipeline. It connects on private land at the existing Sheep pipeline RFFA yard in T11S, R90W, Sec. 8, NENE, traverses National Forest System lands to the NE cross country but parallel to NFSR 851 and tie into Bull Mountain Pipeline on National Forest System lands in T11S, R90W, Sec. 3, SWSW. Colorado’s population has grown significantly in the past 10 years, and an increasing number of people are living near or seeking local BLM- administered lands for a diversity of recreational opportunities characterized by the “mountain resort or outdoor lifestyle.” The primary recreational activities in the UFO are motorized vehicle touring, all-terrain vehicle use, Present, RFFA motorcycling, mountain biking, big and small game hunting, fishing, hiking, backpacking, horseback riding, sight-seeing, target shooting, dog-walking, and river boating. Recreation-based visitor use in the UFO has increased in Recreation most areas in recent years and is expected to continue to increase on BLM lands as well as National Forest System lands, State Parks, and private lands. Unauthorized travel. Travel off designated or existing routes as well as the Past, Present, creation of social trails has occurred and is likely to continue to occur. RFFA Forest Service Special Areas; Roadless Area Conservation; Applicability to the National Forests in Colorado; Final Rule (77 Federal Register 39576- 39612, 3 July 2012). The Colorado Roadless Rule provides management Past, Present direction for conserving and managing approximately 4.2 million acres of Colorado Roadless Areas on National Forest System lands. The following table contains recent production data for the three coal mines in the North Fork Valley, within the CEAA. Raw Coal Production in the North Fork Valley Year Averages (Tons) Bowie Average No. 2 Elk Creek West Elk Past, Present Based on Mine Mine Mine Total Coal 5 Years 2,897,076 2,555,310 5,806,743 11,257,129 1 Years Closed Closed 5,551,636 5,551,636 Note: 5-year period ends June 30, 2014; 1-year period is August 1, 2016 through July 31, 2017.

The Elk Creek Mine was a longwall operation north of Somerset, operated by Oxbow Mining, LLC (Oxbow), with a loadout immediately north of Past, Present, Somerset. There are 13,430 acres permitted. The operation is currently RFFA closed. The West Elk Mine is a longwall operation located south and east of

Resource Projects Timing Somerset and is operated by Mountain Coal Company with a loadout about 1 mile east of Somerset. There are 19.855 acres permitted. Bowie No. 2 Mine is a longwall operation located northeast of Paonia, and is operated by Bowie Resources, LLC with a loadout northeast of Paonia. There are 14,540 acres permitted in the combined permits of the Bowie No. 1 and No. 2 Mines accessed by the Bowie No. 2 Mine. The mine is currently idled. Oxbow has completed exploration drilling to confirm the quality, quantity, and extent of the coal within this area. The Oak Mesa project encompassed about 13,873 acres north of Hotchkiss. The coal exploration license expired Past under its own terms in September 2014. There has been no interest expressed in leasing the coal reserves. The Forest Service issued a Notice of Intent to prepare a supplemental Environmental Impact Statement to propose reinstatement of the North Fork Coal Mining Area exception of the Colorado Roadless Rule. The North Fork Coal Mining Area exception was reinstated and became effective in April RFFA 2017. The exception allows for temporary road construction for coal exploration and/or coal-related surface activities in a 19,100-acre area. Under the exception, Arch Coal plans to expand its underground West Elk Mine. The BLM routinely offers land parcels for competitive oil and gas leasing to allow exploration and development of oil and gas resources for public sale. Past, Present, Continued leasing is necessary for oil and gas companies to seek new areas RFFA for oil and gas production, or to develop previously Oil and Gas inaccessible/uneconomical reserves. Leasing Approximately 25% (224,950 acres) of the Federal fluid mineral estate in the UFO (916,030) is already leased. This includes 160,510 acres (24%) of Past, Present BLM surface and 64,440 acres (27%) of split-estate lands (private, state, and local surface with Federal fluid mineral subsurface). GELLC is the sole oil and gas operator in Delta County. Since 2005, GELLC has drilled 13 wells and installed a gathering line for the Spaulding Past, Present Peak Unit, which is north and east of Cedaredge. The GELLC/SGI dual operator proposal for 25 natural gas wells on five pads, 5 miles west of the Bull Mountain Unit, was approved December 7, Past, Present, 2015. Development to date includes one well on the existing pad and one RFFA new well on a new pad. Up to 17 gas wells may be drilled within the next 5 years. Seven APDs are approved and awaiting development. Under BLM EA #DOI-BLM-UFO-2008-035, GELLC is authorized to drill 16 wells on nine pads (the Hotchkiss Federal) in Gunnison County. To date, Past, Present five pads have been constructed and nine wells drilled. (These numbers are included in the CEAA well counts in the next row of this table) Oil and Gas In the CEAA, including all operators and both Federal and Fee minerals, 54 Development wells are currently producing or are capable of producing, 24 wells have Past, Present been abandoned, and 10 wells have been approved but not yet drilled. 150 Well Bull Mountain Master Development Plan: The Bull Mountain Unit Master Development Plan involves the exploration and development of up to 146 natural gas wells, four water disposal wells, and associated infrastructure RFFA on federal mineral leases. The Record of Decision was approved on October 4, 2017 and seven Federal APDs have been approved but not drilled since approval of the Record of Decision. Vessels Coal Mine Methane Capture Project. Methane Drainage System situated above Oxbow Mining LLC’s Elk Creek Mine near Somerset. The company captures low-level coal mine methane emissions produced at the Past, Present mine as a result of past coal extraction and combusts it onsite for electrical generation or thermal destruction and has proposed to expand this operation.

Resource Projects Timing Petrox 1-APD in Somerset Unit: One APD has been submitted by Petrox Resources for development of a lease in the Federal Somerset Unit, a 6,400- acre project area that largely overlies the Pilot Knob Roadless Area north of Somerset. An MDP has been submitted to the Forest Service; however, the RFFA proposal is not currently considered complete. While operations may be considered reasonably foreseeable, specific details of the MDP are insufficient for analysis. Huntsman Unit Proposal: SG has proposed drilling in the Huntsman Unit (COC74403X), which includes three SG leases (COC63886, 63888, and RFFA 63889). SG has proposed one APD there for well 10-89-31 #1 inside lease COC63886. Deadman Gulch APD: SG has proposed an APD (12-89-30#1) inside the LLC Deadman Gulch Unit adjacent to the Petrox Somerset Federal Unit RFFA within the Pilot Knob CRA on lease COC 64169. SG permitted Bull Mountain compressor station on private land NE of the Bull Mountain Unit, T11S, R90W, Section 10, SWNE. Four gas or diesel motors, three compressors, one separator. Intended to provide compression RFFA to assist in moving produced gas from the area through the existing Bull Mountain Gathering line.

Table A-19. USFS and BLM Authors and Reviewers

Name Title Areas of Participation BLM – Colorado River Valley Field Office Cultural Resources, Native American John Brogan Archaeologist Religious Concerns Vanessa Caranese NRS – Fluids Geologist Groundwater, Geology, Fossil Resources Allen Crockett, Ph.D., J.D. Supervisory NRS Project Co-Lead, Vegetation, Forestry Faith Dziedzic GIS Specialist GIS Sylvia Ringer Wildlife Biologist Wildlife, T&E Animals Thane Stranathan Natural Resource Specialist Project Lead Assistant Physical Scientist – Soil, Air, Air Quality and Climate, Noise, Soils, Carmia Woolley Water Surface Water Forest Service – Grand Mesa, Uncompahgre and Gunnison National Forests Albert Borkowski Special Uses Program Manager Special Uses, Recreation Levi Broyles District Ranger Recommending Official Cultural Resources/Native American Catie Freels North Zone Archaeologist Religious Concerns Dennis Garrison Wildlife Biologist Wildlife, T&E Animals, Vegetation Forest Service Project Management Dan Gray Interdisciplinary (Minerals) Assistant Soil, Surface Water, Groundwater, Ashley Hom Hydrologist Wetlands and Other Waters of the U.S. Kyler McCarrel Rangeland Management Specialist Grazing and Rangeland Management Engineering and Minerals NEPA Project Co-Lead, Visual Resources, Access Niccole Mortenson Specialist and Transportation

Name Title Areas of Participation Suzanne Parker Biologist/Botanist Sensitive Plants Bruce Schumacher Paleontologist Fossil Resources Melvin Woody Fisheries Biologist Fisheries BLM – Uncompahgre Field Office Shane Rumsey Archaeologist Cultural Resources Ken Holsinger Ecologist Wildlife, T&E Animals, Fisheries Neil Perry Wildlife Biologist Wildlife, T&E Animals, Fisheries Julie Jackson Recreation and Transportation Access and Transportation Asst. Field Manager Lands and Amy Carmichael UFO Management Team Minerals Greg Larson Field Manager UFO Management Team David Sinton GIS Specialist GIS Hydrologist, NEPA, Planning and Jedd Sondergard Soil, Water Resources Environmental Coordinator BLM District and Regional Staff Resources Planning and Environmental National Environmental Policy Act Gina Phillips Coordinator, Southwest District Compliance Jessica Montag Regional Socioeconomics Specialist Socioeconomics, Environmental Justice

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APPENDIX B

Conditions of Approval (COAs)

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CONDITIONS OF APPROVAL North Fork Mancos Master Development Plan DOI-BLM-CO-N040-2017-0050-EA

The following COAs shall be implemented, where applicable and feasible, to reduce impacts from project activities. These COAs are in addition to all stipulations attached to the respective Federal leases and to any site-specific COAs for individual well pads, presented following these general COAs. Where the surface landowner specifically requests deviation from one or more of these general COAs, the desired deviation shall be brought to the attention of the BLM/Forest Service project lead. Although landowner preferences are accommodated when appropriate, the BLM/Forest Service remain responsible for ensuring that oil and gas activities are conducted in a manner to avoid, minimize, or offset impacts to other resources and resource uses for which a Federal nexus exists. This includes minimizing impacts to National Forest System lands, BLM-administered lands, and Federally protected resources within public lands and project-related private lands.

1. Administrative Notification. GELLC shall notify the BLM/Forest Service representative at least 48 hours prior to initiation of construction. If requested by the BLM/Forest Service representative, the GELLC shall schedule a pre-construction meeting, including key GELLC and contractor personnel, to ensure that any unresolved issues are fully addressed prior to initiation of surface-disturbing activities or placement of production facilities. 2. Engineering Controls. The BLM/Forest Service may require a professional geotechnical engineering analysis prior to construction in areas of known or potential slope instability (landslides, slumps, and rockfalls) and geologic hazards, or in areas with cut-and-fill slopes more than 30 feet in height or with slope angles steeper than the requirements in the Gold Book (BLM and Forest Service 2007). This includes slopes (horizontal:vertical) of 3:1 in erosive soil, 1:1 in common soils, 0.5:1 in conglomerate, and 0.25:1 in solid rock. Based on the engineering analysis, the BLM may require special design such as drainage systems to reduce soil saturation, prevent or minimize erosion, and stabilize the toes of slopes. In such situations, a qualified independent construction inspector or civil/geotechnical engineer shall be onsite during all phases of construction in the at-risk area or as determined by the BLM/Forest Service. The inspector/engineer shall confirm that the pad and/or specific road section are built to specification in the design package including, but not limited to cut-and-full staking, disturbance limits staking, excavation and embankment placement, slope compaction, slope retention devices, slope benching, at-grade and subgrade drainages, stormwater control measures, etc. Inspection reports prepared by the construction inspector or onsite engineer will be submitted to the BLM/Forest Service. 3. Endangered Colorado River Fishes. a. The operator shall include in the well completions report the volumes of fresh water and recycled/reused water used during project development by phase and activity (cementing, mud, acid wash/hydraulic fracturing, hydrostatic pipeline testing, and dust abatement). This requirement is derived from conservation measures specified by the USFWS in its 2017 USFWS Programmatic Biological Opinion (PBO) for four species of endangered big-river fishes in relation to BLM-authorized APDs. This COA will be attached to any approved APD.

Well Name/No.: API No.:

County: Well Pad:

Operator:

Water Use (barrels) Activity Construction Drilling Completion Reused/ Reused/ Fresh Fresh Fresh Recycled Recycled Road/Pipeline/Pad Dust Abatement

Pipeline Hydrostatic Testing

Cementing

Mud

Acid Wash/ Hydraulic Fracturing

b. GELLC shall undertake no drilling or completion activities with the potential to exceed 360 acre- feet per year (slightly more than the total for six wells in the second year) of tributary first-use water without written approval by the BLM/Forest Service, in collaboration with the USFWS. The interagency collaboration would include an evaluation of whether anticipated project depletions above 360 acre-feet in a given year would potentially result in cumulative depletions greater than 607 acre-feet in that year. Specifically, this COA is intended to prevent drilling and completion of more than six wells in each of the third and fourth years of the project unless additional water sources and/or storage facilities, or modifications in GELLC’s completion method would satisfy the conservation measures in the PBO. 4. Construction Staking. New access road and/or pipeline centerlines shall be flagged and staked prior to the start of tree/brush clearing and/or earthwork within the planned disturbance corridor. The edges of disturbance shall be established with flagging before the clearing work is completed. Any stakes that are disturbed, displaced, or removed shall be repositioned or replaced (as needed) as construction proceeds. Stakes shall be visible from one to the next and no farther apart than 100 feet. 5. Road Construction and Maintenance. Roads shall be crowned, ditched, surfaced, drained with culverts and/or water dips, and constructed to Gold Book standards. Initial gravel application shall be a minimum of 6 inches. GELLC shall provide timely year-round road maintenance and cleanup on the access roads. A regular schedule for maintenance shall include, at a minimum, all necessary blading, ditch and culvert cleaning, road surface replacement, and dust abatement. When rutting within the traveled way becomes greater than 6 inches, blading and/or gravelling shall be conducted as approved by the BLM/Forest Service. An engineered design would be required for the access road to DGU 1289 #20-23 well pad prior to approval for surface disturbance due to steep slopes. Most of the Option 1 access road was not surveyed because the private landowner denied permission for surveys. If Option 1 is the route included in the APD/SUPO for the SPU Federal 1190 #20 well pad, a wetland delineation would be required in combination with other resource surveys prior to construction. If necessary based on the surveys, GELLC would be required to make adjustments to the alignment, and/or the BLM/Forest Service would place seasonal constraints on the timing of construction, to ensure adequate resource protection. 6. Road Use. Use of Stevens Gulch Road is not proposed or anticipated and shall be used for emergency access/egress only. Delta County shall be consulted prior to any use of this road as a part of regular operations.

7. Vegetation Clearing. Trees, brush, and slash to be cleared within the limits of disturbance for the project shall be chipped and used in reclamation or hauled to an approved disposal site. When chipping trees, slash, and brush, the material generated shall be distributed in a manner to not impede seeding operations or reduce the potential for successful revegetation. 8. Proposed Surface Freshwater Pipeline Installation and Operation. GELLC shall adhere to the following stipulations, and all additional stipulations, to be attached to the new and amended right-of- way grants, if approved, for crossing BLM surface lands: a. Prior to laying the surface pipeline in the 0.65-mile segment along an existing two-track route, GELLC shall survey the alignment for cultural resources potentially eligible for the National Register of Historic Places (NRHP). If any potentially eligible sites are discovered that could be affected by pipeline installation, the alignment shall be rerouted to avoid impacts to the sites. b. If potential Waters of the U.S. are identified that could be affected by pipeline installation on BLM land, GELLC shall contact the U.S. Army Corps of Engineers (USACE) to request a jurisdictional determination pursuant to Section 404 of the Clean Water Act and a determination of the availability of an applicable Nationwide Permit to authorize any anticipated impacts to WOTUS. GELLC shall comply with any requirements established by the USACE. c. Following pipeline installation on the 1.55-mile across BLM surface, GELLC shall, during the period June through August of the year of installation, survey the portions across BLM surface to identify and map infestations of State-listed noxious weeds and shall implement weed treatments. The weed treatments shall be consistent with requirements of COA #18.k., below, regarding use of herbicides and reporting of the survey and treatment results. d. In addition to these special stipulations, GELLC shall coordinate with other ROW holders regarding timing, duration, method, and exact alignment of surface pipeline installation. 9. Buried Pipeline Installation and Operation. Unless otherwise authorized in writing by the BLM/Forest Service, buried gas gathering lines and buried water pipelines serving the same surface location shall be installed in the same trench and collocated with the associated access road. To minimize the amount of open trench ahead of pipe laying and backfilling, no more than the amount of trench that can be worked in a day shall be open at any given time. Backfilling operations shall be performed within a reasonable amount of time of the lowering operation to ensure the trench is not left open for more than 24 hours. Trenches left open overnight shall be fenced with a temporary fence or other methods approved by the BLM/Forest Service. The ends of the trench shall be sloped (3h:1v) to allow people or animals to escape. The welded steel buried pipelines (12-inch natural gas and 6-inch water) shall be collocated in the same trench during the same installation period. If GELLC determines that hydrostatic pressure-testing of pipelines with water instead of an inert gas is necessary, the water used shall not be discharged but shall be contained and transported to an approved treatment or disposal facility. GELLC shall inform the BLM/Forest Service within 48 hours of any releases from pipelines onto Federal lands that require reporting to the Department of Transportation pursuant to 49 CFR Part 195. 10. Saturated Soil Conditions. When saturated soil conditions exist on the access road or along the pipeline disturbance, any type of construction shall be halted until the soil material dries out or is frozen sufficiently for construction to proceed with no or minimal erosion and damage to soils. 11. Soils and Erosion. Cuts and fills shall be minimized when working on slopes in excess of 30% and on fragile soils. Cut-and-fill slopes shall be stabilized through revegetation practices with an approved seed mix shortly following construction activities to minimize the potential for slope failures, erosion, and soil loss. Slopes adjacent to drainages shall be protected with best management

practices (BMPs) designed to minimize sediment transport. The BLM/Forest Service may require GELLC to utilize special construction or reclamation techniques to ensure subsequent slope stability and facilitate revegetation success. 12. Dust Abatement. GELLC shall implement dust abatement measures as needed to prevent fugitive dust from vehicular traffic, equipment operations, or wind events. The BLM/Forest Service may direct GELLC to change the level and type of treatment (watering or application of various dust- suppressing agents, surfactants, and road surfacing materials) if dust abatement measures are observed to be insufficient. 13. Drainage Crossings and Culverts. Construction activities at perennial, intermittent, and ephemeral drainage crossings (e.g., burying pipelines, installing culverts) shall be timed to avoid high flow conditions. Construction that disturbs any flowing stream shall utilize either a piped stream diversion or a cofferdam and pump to divert flow around the disturbed area. Culverts at drainage crossings shall be designed and installed to pass a 25-year or greater storm event. On perennial and intermittent streams, culverts shall be designed to allow for passage of aquatic biota. The minimum culvert diameter in any installation for a drainage crossing or road drainage shall be 24 inches. Due to the flashy nature of area drainages and anticipated culvert maintenance, the U.S. Army Corps of Engineers (USACE) recommends designing drainage crossings for the 100-year event. Contact the USACE Colorado West Regulatory Branch at 970-243-1199. Pipelines installed beneath stream crossings shall be buried at a minimum depth of 4 feet below the channel substrate to avoid exposure by channel scour and degradation. Following burial, the channel grade and substrate composition shall be returned to pre-construction conditions. 14. Jurisdictional Waters of the U.S. GELLC shall obtain appropriate permits or verification of the applicability and sufficiency of a Nationwide Permit or Regional Permit from the USACE prior to discharging fill material into Waters of the U.S., in accordance with Section 404 of the Clean Water Act. Waters of the U.S. are defined in 33 CFR Section 328.3 and may include wetlands as well as perennial, intermittent, and ephemeral streams. Permanent impacts to jurisdictional waters may require mitigation. Contact the USACE Colorado West Regulatory Branch at 970-243-1199. 15. Protection of State-Classified Water Supply Stream Segments. For the following well pads – IPU 1291 #13-24 and DGU 1289 #20-23 -- located within 15 stream-miles of a downstream Public Water System (West Elk Mine PWS and Bowie Mine #2 PWS), GELLC shall: a. Notify the owner/operator of the downstream PWS prior to commencement of surface-disturbing activities. b. Prepare an emergency spill response plan, including employee training and current contact information for the downstream PWS. c. In the event of a spill or release, immediately implement its emergency response procedures. If a spill or release impacts or threatens to impact any surface water, GELLC shall immediately report the discovery of the release to the COGCC and the Environmental Release/Incident Report Hotline in accordance with COGCC Rule 906.b.(4). 16. Escape Ramps (Open Pits and Cellars, Tanks, and Trenches). GELLC shall construct and maintain escape ramps, ladders, or other methods of escape by wildlife from each pit, cellar, open-top tank, and trench. Ramps shall be secured and properly positioned to allow wildlife to escape. 17. Cuttings Management. Prior to being buried or stacked on-site within the existing pad footprint, the cuttings generated from the drilling operations of the proposed wells shall be mixed with soils developed from an excavated vault (if necessary), tested for constituents of concern listed in COGCC Table 910-1, and meet Table 910-1 concentration levels and standards (or obtain COGCC approval of the testing results). If the cuttings, or any portion of the cuttings, fail to satisfy Table 910-1

concentration levels or gain COGCC approval, the cuttings shall be transported to an approved disposal facility. GELLC shall provide load tickets and/or chain of custody records for such hauling operations upon request from the BLM/Forest Service. 18. Reclamation. Specific measures to follow during interim reclamation are described below. a. Reclamation Plans. In areas that have low reclamation potential or are especially challenging to restore, reclamation plans will be required for APD approval. The plan shall contain the following components: detailed reclamation plats, including contours and indicating irregular rather than smooth contours; timeline for drilling completion, interim reclamation earthwork, and seeding; soil test results and/or a soil profile description; amendments to be used; soil treatment techniques such as roughening, pocking, and terracing; erosion control techniques such as hydromulch, blankets/matting, and wattles; and visual mitigations if in a sensitive visual resource management (VRM) area. b. Deadline for Interim Reclamation Earthwork and Seeding. Interim reclamation to reduce a well pad to the maximum size needed for production, including earthwork and seeding of the interim reclaimed areas, shall be completed within 6 months following completion of the last well planned to be drilled on that pad as part of a continuous operation. If a more than 1 year is expected to occur between drilling episodes, the BLM/Forest Service may require implementation of all or part of the interim reclamation program. Reclamation, including seeding of temporarily disturbed areas along roads and pipelines and of topsoil piles and berms, shall be completed within 30 days following construction. Any area on which construction is completed prior to December 1 shall be seeded during the remainder of the early winter season instead of during the following spring, unless BLM/Forest Service approves otherwise based on weather. If road or pipeline construction occurs discontinuously (e.g., new segments installed as new pads are built) or continuously but with a total duration greater than 30 days, the subsequent reclamation, including seeding, shall be phased such that no portion of the temporarily disturbed area remains in an unreclaimed condition longer than 30 days. The BLM/Forest Service may authorize deviation from this requirement based on the season and the amount of work remaining on the entirety of the road or pipeline when the 30-day period has expired. If requested by the BLM/Forest Service for a specific pad or group of pads, GELLC shall contact the BLM/Forest Service by telephone or email approximately 72 hours before reclamation and reseeding begin. This will allow the BLM//Forest Service to schedule a pre-reclamation field visit if needed to ensure that all parties are in agreement and to provide time for adjustments to the plan before work is initiated. Deadlines for seeding described above are subject to extension upon approval by the BLM/Forest Service based on season, timing limitations, or other constraints on a case-by-case basis. If the BLM/Forest Service approves an extension for seeding, GELLC may be required to stabilize the reclaimed surfaces using hydromulch, erosion matting, or other method until seeding is implemented. c. Topsoil Stripping, Storage, and Replacement. All topsoil shall be stripped following removal of vegetation during construction of well pads, pipelines, roads, or other surface facilities. In areas of thin soil, a minimum of the upper 6 inches of surficial material shall be stripped. The BLM/Forest Service may specify a stripping depth during the onsite visit or based on subsequent information regarding soil thickness and suitability. The stripped topsoil shall be stored separately from subsoil or other excavated material and replaced prior to final seedbed preparation. The BLM/Forest Service BMP for windrowing of topsoil shall be implemented for well pad construction whenever topography allows.

d. Windrowng of Topsoil. Topsoil shall be windrowed around the pad perimeter to create a berm that limits and redirects stormwater runoff and extends the viability of the topsoil per BLM Topsoil Best Management Practices (BLM 2009 PowerPoint presentation available upon request from BLM – CRVFO). Topsoil shall also be windrowed, segregated, and stored along pipelines and roads for later spreading across the disturbed corridor during final reclamation. Topsoil berms shall be promptly seeded to maintain soil microbial activity, reduce erosion, and minimize weed establishment. e. Seedbed Preparation. For cut-and-fill slopes, initial seedbed preparation shall consist of backfilling and recontouring to achieve the configuration specified in the reclamation plan. For compacted areas, initial seedbed preparation shall include ripping to a minimum depth of 12 inches, with a maximum furrow spacing of 2 feet. Where practicable, ripping shall be conducted in two passes at perpendicular directions. Following final contouring, the backfilled or ripped surfaces shall be covered evenly with topsoil. If directed by the BLM/Forest Service, GELLC shall implement measures following seedbed preparation (when broadcast-seeding or hydroseeding is to be used) to create small depressions (pocking) to enhance capture of moisture and establishment of seeded species. Depressions shall be no deeper than 1 to 2 inches and shall not result in piles or mounds of displaced soil. Excavated depressions shall not be used unless approved by the BLM/Forest Service for the purpose of erosion control on slopes. Where excavated depressions are approved by the BLM/Forest Service, the excavated soil shall be placed only on the downslope side of the depression. f. Seed Mixes. A seed mix selected from among the three habitat-based mixes presented in Table B-1 below shall be used in revegetating all temporarily disturbed areas resulting from project- related activities. Table B-1. Seed Mixtures for Use in NFMMDP Revegetation (60 seeds/square foot drill-seeded; 120 seeds/square foot broadcast-seeded)

Elevation % of Mix Seeds per Habitat Type Species PLS lbs/acre (feet) (PLS seeds) Pound Bottlebrush squirreltail 16 192k 2.2 Galleta 16 159k 2.6 Great Basin wildrye 16 130k 3.2 Pinyon- 6,000 to 7,000 Indian ricegrass 16 141k 2.9 Juniper Sandberg bluegrass 16 1,050k 0.4 Western wheatgrass 20 110k 4.8 Total 100 -- 16.1 Bluebunch wheatgrass 15 140k 2.8 Indian ricegrass 15 141k 2.8 Mountain bromegrass 20 64k 8.2 Mountain 7,000 to 8,000 Prairie junegrass 15 2,315k 0.2 Shrub Rocky Mountain fescue 15 1,200k 0.3 Western wheatgrass 20 110k 4.8 Total 100 -- 19.1

Elevation % of Mix Seeds per Habitat Type Species PLS lbs/acre (feet) (PLS seeds) Pound Blue wildrye 26 134k 3.1 Canby bluegrass 16 926k 0.5 Aspen or Mountain bromegrass 26 64k 10.6 8,000 to 9,500 Spruce-Fir Nodding bromegrass 16 143k 2.9 Slender wheatgrass 16 159k 2.6 Total 100 -- 19.7 Temporary Revegetation (for use on National Forest System lands only) * Regreen (brand name) 20 lbs/acre @ 11,000 seeds/pound All Habitats in Project Area Tall wheatgrass x winter wheat = 5.0 seeds/square foot Pioneer (brand name) 20 lbs/acre @ 13,500 seeds/pound All Habitats in Project Area Triticale x winter wheat = 6.2 seeds/square foot

A different seed mix will be allowed on private land if a specific mix is provided by the landowner. Seed used in project-related revegetation, including private land, shall contain no prohibited or restricted noxious weed seeds, and shall contain no more than 0.5 percent by weight of other weed seeds. Seed may contain up to 2.0 percent of “other crop” seed by weight, including the seed of other agronomic crops and native plants; however, a lower percentage of other crop seed is recommended. The operator shall provide seed mix labels (seed tags) that include purity test results, species composition, and percentage of each species (based on numbers of pure live seeds [PLS] per square foot of area seeded, not on weight) to the Forest Service (for National Forest System lands) or to the BLM (for BLM or private lands) for review and acceptance at least 14 days prior to seeding. Seed that does not meet the above criteria shall not be applied. The quantities of PLS (pure live seeds) per acre for each species, and the combined mix, are based on 60 PLS per square foot for drill-seeding. This rate shall be doubled to 120 PLS per square foot (twice the quantities shown in the table) for broadcast-seeding or hydroseeding. g. Seeding Procedures. Seeding shall be conducted no more than 24 hours following completion of final seedbed preparation. Where practicable, seed shall be installed by drill-seeding. When drill-seeding, the drill should be set between 0.25 and 0.5 inch deep, and the seeding should be conducted along the contour of the slope to prevent erosion. The seed-drill should be equipped with the following: i. Multiple seed boxes for different types of seed ii. Agitators and picker wheels in at least one box for fluffy seed iii. Double disc furrow openers iv. Intact depth bands with functioning scrapers on all disc openers to ensure consistent, uniform seed depth placement v. Seed tubes, which drop between disc openers, large enough to handle fluffy seed vi. Packer wheels with adjustable tension, to provide proper soil compaction over and adjacent to the seed vii. Coulter wheels to allow penetration of furrow openers where seeding into heavy mulch or cover crop.

Where drill-seeding is impracticable, seed may be installed by broadcast-seeding at twice the drill-seeding rate, followed by raking or harrowing to provide 0.25 to 0.5 inch of soil cover or by hydroseeding and hydromulching. Hydroseeding and hydromulching shall be conducted in two separate applications to ensure adequate contact of seeds with the soil. If interim revegetation is unsuccessful, GELLC shall implement subsequent reseedings until interim reclamation standards are met. h. Mulch. Mulch shall be applied within 24 hours following completion of seeding in project areas within pinyon-juniper or sagebrush shrubland habitat types. Mulch may consist of either hydromulch or of certified weed-free straw or certified weed-free native grass hay crimped into the soil. Mulch shall not be used within mountain shrub or aspen/spruce-fir forest habitat types, unless specified or approved by the BLM/Forest Service. NOTE: Mulch is not required in areas where erosion potential mandates use of a biodegradable erosion-control blanket (straw matting). i. Erosion Control. Cut-and-fill slopes shall be protected against erosion with the use of water bars, lateral furrows, or other BMPs approved by the BLM/Forest Service. Additional BMPs such as biodegradable wattles, weed-free straw bales, or silt fences shall be employed as necessary to reduce transport of sediments into drainages. The BLM may require use of hydromulch or biodegradable blankets/matting in areas with high erosion potential to ensure adequate protection from slope erosion and offsite transport of sediments and improve plant establishment. j. Monitoring. The operator shall conduct annual monitoring surveys of all sites categorized as “operator reclamation in progress” and shall submit an annual monitoring report of these sites, including a description of the monitoring methods used, to the BLM/Forest Service by December 31 of each year. The annual monitoring report shall document whether attainment of reclamation objectives appears likely. If one or more objectives appear unlikely to be achieved, the report shall identify appropriate corrective actions. Upon review and approval of the report by the BLM/Forest Service, GELLC shall be responsible for implementing the corrective actions or other measures specified by the BLM/Forest Service. k. Weed Control. Before mobilization of equipment onto public land, the GELLC shall perform inspections to ensure that all construction equipment and vehicles are clean and free of soil, mud, and plant material. Operators of vehicles and other mobile equipment shall avoid driving through or parking on weed infestations. GELLC shall regularly monitor and promptly control noxious weeds and other undesirable plant species. A Pesticide Use Proposal (PUP) must be approved by the BLM/Forest Service prior to the use of herbicides. Annual weed monitoring reports, including GPS shapefiles of treatment areas and Pesticide Application Records (PARs) for the ROW alignments shall be submitted annually to BLM Colorado River Valley Field Office (CRVFO) and the Forest Service Paonia Ranger District by December 1 and October 1, respectively. 19. Big Game Winter Range Timing Limitation. To minimize impacts to wintering big game, no construction, drilling, or completion activities shall occur during a Timing Limitation (TL) period from December 1 through April 30 annually. Requests for exceptions shall be submitted to the BLM and Forest Service on a Sundry Notice describing the location to which the exception would apply if granted (including a location map), the reason for the request, the dates for which the exception is requested, the type of activity planned, and whether the work would be limited to daylight hours. After an initial internal evaluation, the BLM/Forest Service may deny the request, or consider it further in collaboration with Colorado Parks and Wildlife. Mitigation measures to minimize impacts to wintering big game, or to offset the impacts such as through habitat treatments to improve winter range, may be required for granting an exception to this TL.

20. Special Status Species. a. Yellow-billed Cuckoo. Water hauling from the City of Delta shall generally occur outside the peak yellow-billed cuckoo breeding season (May through July) to minimize the potential for impacts to cuckoos occupying habitat within the proposed critical habitat on the North Fork of the Gunnison River parallel to SH 133. b. Purple Martin. All active nest sites shall be avoided. Removal of inactive nest sites documented during preconstruction surveys shall be avoided, where feasible. c. Threatened Green Lineage Colorado River Cutthroat Trout. The following conservation measures shall be implemented: i. Stormwater controls for the IPU 1291 #13-24 well pad shall ensure that pad runoff through the stormwater control features is collected in a constructed and lined stormwater basin adjacent to the pad. ii. The stormwater basin shall be promptly cleaned out when sediments reduce stormwater basin containment to less than two-thirds of available capacity. iii. The constructed stormwater basin shall discharge to upland vegetation, and shall not drain toward drainage channels. iv. If GELLC or any of its contractors withdraws water directly from Muddy Creek or other perennial stream, all pump intakes shall be screened with 0.25-inch or finer mesh material to reduce injury or mortality by entrainment or impingement. v. The measures listed below for BLM/Forest Service sensitive fish species shall also apply in waters supporting or potentially supporting the Green Lineage Colorado River cutthroat trout. d. BLM/Forest Service Sensitive Fish Species. To minimize potential effects to spawning and juvenile bluehead and flannelmouth suckers in West Muddy Creek, GELLC shall not construct the access road and gathering line to the DGU 1289 #20-23 well pad or undertake any other construction activities within or adjacent to the West Muddy Creek channel from May 1 through July 1 of any year. . Construction activities in proximity to West Muddy Creek outside this TL period shall include placement of silt fences or straw wattles and maintenance of as much vegetated buffer as practicable to avoid or minimize transport of sediments into the channel. Straw/hay bales shall not be used. Any pipes or hoses used to withdraw water from West Muddy Creek shall be screened with a 0.25-inch or finer mesh screen. During dust suppression, water shall not be applied to surfaces in volumes that would result in runoff from the road into drainages. i. All herbicides used near drainages shall be non-toxic to fish and other aquatic organisms. ii. If water is used for hydrostatic testing of pipelines, such water shall be transported to an approved treatment or disposal facility and shall not be discharged onto the ground. iii. Water generated by dewatering of pipeline trenches during construction shall be discharged in an upland area at least 150 feet from wetlands and other jurisdictional WOTUS, and in a manner to allow infiltration into the ground without causing erosion. BLM/Forest Service approval of the discharge location and proposed BMPs shall be obtained before discharging such water. 21. Bald and Golden Eagles. It shall be the responsibility of GELLC to comply with the Bald and Golden Eagle Protection Act (Eagle Act) with respect to “take” of either eagle species. Under the Eagle Act, “take” includes to pursue, shoot, shoot at, poison, wound, kill, capture, trap, collect, molest and disturb. “Disturb” means to agitate or bother a bald or golden eagle to a degree that causes, or is

likely to cause, based on the best scientific information available, (1) injury to an eagle; (2) a decrease in its productivity by substantially interfering with normal breeding, feeding, or sheltering behavior; or (3) nest abandonment by substantially interfering with normal breeding, feeding, or sheltering behavior. Avoidance of eagle nest sites, particularly during the nesting season, is the primary and preferred method to avoid a take. Any oil or gas construction, drilling, or completion activities planned within 0.5 mile of a bald or golden eagle nest, or other associated activities greater than 0.5 miles from a nest that may disturb eagles, shall be coordinated with the BLM project wildlife biologist (Sylvia Ringer, 970-876-9062), the Grand Mesa, Uncompahgre, and Gunnison National Forests (GMUG) wildlife biologist (Dennis Garrison, 970-527-4131 x4259), and the U.S. Fish and Wildlife Service (USFWS) representative for oil and gas (Creed Clayton, 970-243-2778 x28). 22. Raptor Nesting. To protect nesting raptors, a survey shall be conducted prior to construction, drilling, or completion activities that are to begin during the general raptor nesting season (February 1 to August 15). The survey shall include all potential nesting habitat within species-specific buffer distances (see the following table) from proposed construction, drilling, or completion activities, or other activities potentially interfering with raptor nesting. Selection of an appropriate survey width shall be based on the raptor species considered as potentially nesting in an area based on elevation and habitat type, and shall be approved by the BLM/Forest service prior to initiating the surveys. Results of the survey shall be submitted to the BLM/Forest Service. The BLM/Forest Service may grant an exception to the TL if a previously identified or new nest structure identified within the species-specific buffer widths is documented to be inactive during the typical nesting season for that species. Species-specific buffer distances and typical nesting dates are shown in Table B-2: Table B-2. Temporal and Spatial Buffers for Raptor Nest Surveys and Active Nests

Common Name Spatial Buffers (mile) Temporal Buffers (Scientific Name) 1 Bald eagle (Haliaeetus leucocephalus) 2 1.0 Oct 15 – Jul 31 Golden eagle (Aquila chrysaetos) 2 0.50 Dec 15 – Jul 15 Ferruginous hawk (Buteo regalis) 2 -- unlikely 0.50 Feb 1 – Jul 31 Red-tailed hawk (Buteo jamaicensis) 2 0.33 Feb 15 – Jul 15 Swainson’s hawk (Buteo swainsoni) 4 0.25 Mar 1 – Jul 31 Northern goshawk (Accipiter gentilis) 3 0.50 Mar 1 – Sept 15 Cooper’s hawk (Accipiter cooperii) 5 0.25 Apr 1 – Aug 15 Sharp-shinned hawk (Accipiter striatus) 5 – unlikely 0.25 Apr 1 – Aug 15 Northern harrier (Circus hudsonius) 5 0.25 Apr 1 – Aug 15 Osprey (Pandion haliaeetus) 2 – unlikely 0.25 Mar 1 – Aug 31 Peregrine falcon Falco peregrinus) 4 – unlikely 1.0 Feb 1 – Jul 31 Prairie falcon (Falco mexicanus) 2 0.50 Mar 1 – Jul 31 Great horned owl (Bubo virginianus) 5 0.25 Feb 1 – Aug 15 Long-eared owl (Asio otus) 5 0.25 Mar 1 – Jul 15 Flammulated owl (Psiloscops flammeolus) 5 0.25 Apr 1 – Aug 1 Northern saw-whet owl (Aegolius acadicus) 5 0.25 Mar 1 – Jul 15 Based on buffer distances and nesting dates Other birds of prey appropriate for the species at the specific elevation. 1 All species listed are considered potential nesters in the NFMMDP area, based on geographic range, elevation, and habitat types, except where indicated as “unlikely”

Common Name Spatial Buffers (mile) Temporal Buffers (Scientific Name) 1 2 Buffers based on Forest Service (1991) and CPW (2008), whichever is more restrictive. 3 Buffers based on CPW (2008). 4 Buffers based on Forest Service (1991). 5 Buffers based on BLM (2011).

23. Migratory Birds – Nesting. All vegetation removal or surface disturbance in previously undisturbed lands providing potential nesting habitat for migratory birds is prohibited from May 15 to July 15. An exception to this TL may be granted if nesting surveys conducted no more than one week prior to surface-disturbing activities indicate that no migratory bird species are nesting within 30 meters (100 feet) of the area to be disturbed. Nesting shall be deemed to be occurring if a territorial (singing) male is present within the distance specified above. Nesting surveys shall include an audial survey for diagnostic vocalizations in conjunction with a visual survey for adults and nests. Surveys shall be conducted by a qualified breeding bird surveyor between sunrise and 10:00 AM under favorable conditions for detecting and identifying migratory birds. This provision does not apply to areas that have been cleared of vegetation prior to May 1 of the year in which construction occurs. 24. Migratory Birds – General. It shall be the responsibility of GELLC to comply with the Migratory Bird Treaty Act (MBTA) with respect to “take” of migratory bird species, which includes injury and direct mortality resulting from human actions not intended to have such result. To minimize the potential for the take of a migratory bird, GELLC shall take reasonable steps to prevent use by birds of fluid-containing pits associated with oil or gas operations except those containing only fresh water. GELLC shall install netting with a mesh size of 1 to 1.5 inches, and suspended at least 4 feet above the fluid surface, on all pits into which fluids are placed, except for storage of fresh water in a pit that contains no other material. The netting shall be installed within 24 hours of placement of fluids into a pit. The requirement for netting does not apply to pits during periods of continuous, intensive human activity at the pad, such as drilling and hydraulic fracturing phases. 25. Range Management. Range improvements (fences, gates, reservoirs, pipelines, etc.) shall be avoided during construction and other oil and gas activities to the extent possible. If range improvements are damaged during exploration and development, GELLC will be responsible for repairing or replacing the damaged range improvements. Where a proposed access road bisects an existing livestock fence, a steel frame gate, or cattleguard with associated bypass gate shall be installed across the roadway to control grazing livestock. GELLC shall minimize the open length of pipeline trenches at any one time. Trenches remaining open overnight while cattle are grazing in the area shall have temporary construction fencing or other means of reducing the risk to livestock. Soft plugs of excavated material with ramps on either side shall be provided at well-defined livestock trails to allow access across the trench and provide a means of escape for livestock that fall into the trench. The sides of trenches left open shall be shored to reduce the risk of collapse. 26. Paleontological Resources. If in connection with operations under this authorization any of the above resources are encountered, GELLC shall immediately suspend all activities in the immediate vicinity of the discovery that might further disturb such materials and notify the BLM/Forest Service of the findings. The discovery must be protected until notification from the BLM/Forest Service to resume the prior activities. 27. Cultural Education/Discovery. All persons in the area who are associated with this project shall be informed that if anyone is found disturbing historic, archaeological, or scientific resources, including collecting artifacts, the person or persons would be subject to prosecution.

If subsurface cultural values are uncovered during operations, all work in proximity to the resource will cease and the BLM/Forest Service notified immediately. GELLC shall take any additional measures requested by the BLM/Forest Service to protect discoveries until they can be adequately evaluated by the permitted archaeologist. Within 48 hours of the discovery, the State Historic Preservation Office (SHPO) and consulting parties will be notified of the discovery and consultation will begin to determine an appropriate mitigation measure. The BLM/Forest Service, in cooperation with GELLC, will ensure that the discovery is protected from further disturbance until mitigation is completed. Operations may resume at the discovery site upon receipt of written instructions and authorization by the BLM/Forest Service. Pursuant to 43 CFR 10.4(g), GELLC must notify the BLM/Forest Service, by telephone, with written confirmation, immediately upon the discovery of human remains, funerary items, sacred objects, or objects of cultural patrimony on Federal land. Further, pursuant to 43 CFR 10.4 (c) and (d), GELLC must stop activities in proximity to the discovery that could adversely affect the discovery. The GELLC shall make a reasonable effort to protect the human remains, funerary items, sacred objects, or objects of cultural patrimony for a period of 30 days after written notice is provided to the Authorized Officer, or until the Authorized Officer has issued a written notice to proceed, whichever occurs first. Antiquities, historic ruins, prehistoric ruins, and other cultural or paleontological objects of scientific interest that are outside the authorization boundaries but potentially affected, either directly or indirectly, by the Proposed Action shall also be included in this evaluation or mitigation. Impacts that occur to such resources as a result of the authorized activities shall be mitigated at GELLC’s cost, including the cost of consultation with Native American groups. Any person who, without a permit, injures, destroys, excavates, appropriates or removes any historic or prehistoric ruin, artifact, object of antiquity, Native American remains, Native American cultural item, or archaeological resources on public lands is subject to arrest and penalty of law (16 USC 433, 16 USC 470, 18 USC 641, 18 USC 1170, and 18 USC 1361). 28. Visual Resources. Production facilities shall be placed to avoid or minimize visibility from travel corridors, residential areas, and other sensitive observation points, unless directed otherwise by the BLM/Forest Service due to other resource concerns. Production facilities shall be placed to maximize reshaping of cut-and-fill slopes and interim reclamation of the pad. To the extent practicable, existing vegetation shall be preserved when clearing and grading for pads, roads, and pipelines. The BLM/Forest Service may direct that cleared trees and rocks be salvaged and redistributed over reshaped cut-and-fill slopes or along linear features. Aboveground facilities shall be painted with a BLM/Forest Service-approved color to minimize contrast with adjacent vegetation or rock outcrops. 29. Recreation. During construction, drilling, and completion activities, warning signs shall be posted on the access road to alert landowners, recreationists, and other travelers of heavy truck traffic, trucks entering the road, and slow-moving equipment. Signs shall be posted at the road junction closest to the pad and at a more distant junction that provides an alternative route for travelers. GELLC shall also provide notice of construction schedules and road closures to affected landowners, affected guides and outfitters, and first responders (fire, injury, law enforcement, etc.) for the area. Rig moves, initiation of construction, and major maintenance activities shall be avoided during the first weekend of the first and second rifle seasons to reduce impacts to hunters 30. Gates. Where directed by the Forest Service, the operator shall install gates across new access roads on National Forest System lands. The purpose of this COA is to reduce the risk of damage to

National Forest System lands and associated resources from off-highway recreational travel. The type of gate shall be specified or approved by the Forest Service. 31. Fire. GELLC shall adhere to its Fire Safety and Evacuation Plan and shall implement such additional measures as necessary to prevent fires on public and private land. GELLC may be held responsible for the costs of suppressing fires on public land that result from the actions of its employees, contractors, or subcontractors. Range or forest fires caused or observed by GELLC’s employees, contractors, or subcontractors shall be reported immediately to the BLM Grand Junction Dispatch at 970-257-4800. All fires or explosions that cause damage to property or equipment, loss of oil or gas, or injuries to personnel shall be reported immediately to the BLM CRVFO at 970-876-9000, the BLM Uncompahgre Field Office (UFO) at 970-240-5300, or the GMUG Paonia Ranger District at 970-527-4131. During conditions of extreme fire danger, surface-use operations may be restricted or suspended in specific areas, or additional measures may be required by the BLM/Forest Service. Any welding, acetylene, or other open flame shall be operated in an area barren or cleared of all flammable materials and no closer to vegetation than at least 10 feet. All precautions shall be taken to prevent wildfires. During conditions of extreme fire danger (e.g., National Weather Service issued Red Flag warning), surface use operations may be limited or suspended in specific areas. Internal combustion engines shall be equipped with approved spark arrestors, and vehicles shall be parked in designated areas without fire/fuels hazards. 32. Noise. To limit the impact of noise on nearby residents or temporary users of nearby public and private lands, construction of well pads, access roads, pipelines, and other surface facilities shall occur during daytime hours to the extent practicable. All equipment shall have sound-control devices no less effective than those provided by the manufacturer. All equipment shall have muffled exhausts. Engine braking by trucks is not be allowed on BLM/Forest Service roads or on roads across private surface used for access for project-related activities. Construction, well development, and maintenance workers shall comply with posted speed limits on public roads and limit driving to 25 miles per hour on unpaved, unposted roads to reduce traffic-related noise. 33. Noise Abatement for on-pad Production Compressors, Generators, and Pumps. Any production equipment operated for extended periods on a Federal oil and gas lease and/or BLM or National Forest System lands shall adhere to the Residential/Agricultural/Rural Zone standard established in Colorado Oil and Gas Conservation Commission (COGCC) Regulation No. 802, Noise Abatement. Under this prevision, the noise level shall not exceed 50 A-weighted decibels (dBA) between 7:00 p.m. and 7:00 a.m. (nighttime) and 55 dBA between 7:00 a.m. and 7:00 p.m. (daytime) at a distance of 350 feet from the noise source. This standard shall apply even in remote locations where the COGCC may consider the standard for the Light Industrial zone to be sufficient due to no residences occurring in proximity to the noise source. Noise control techniques to be considered for on-pad production-related equipment shall include, but not be limited to, enclosure within a sound-insulated structure, installation of an improved muffler system, a combination of these, or potentially the use of electrical power. Methods for safe ventilation of sound-insulated buildings shall be incorporated into building design to avoid open doors or windows that defeat the intended noise controls. Any noise-abating structure shall use the same BLM-approved color as used on other production facilities on the pad. If the BLM/Forest Service determines that the required noise standard for the Residential/Agricultural/Rural noise standard is not being met under normal production conditions, the operator may be required to suspend use of the on-pad noise-generating equipment or implement additional noise abatement measures.

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APPENDIX C

Transportation Plan

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Transportation Plan

North Fork Mancos Master Development Plan Gunnison Energy LLC

Prepared for:

Bureau of Land Management Colorado River Valley Field Office and U.S. Forest Service Grand Mesa, Gunnison, and Uncompahgre National Forests

February 2019

TRANSPORTATION PLAN North Fork Mancos Master Development Plan DOI-BLM-CO-N040-2017-0050-EA

1. INTRODUCTION This Transportation Plan addresses road use and traffic associated with the proposed Gunnison Energy LLC (GELLC) North Fork Mancos Master Development Plan (NFMMDP). The NFMMDP Federal units are located in the northwestern corner of Gunnison County and on the eastern edge of Delta County in the North Fork of the Gunnison River Basin of west central Colorado. The NFMMDP project area is located approximately 10 miles northeast of Paonia, Colorado, and approximately 20 miles southwest of Carbondale, Colorado. This Transportation Plan was created to address traffic associated with the NFMMDP development and specifically truck traffic associated with water and sand delivery to support slickwater hydraulic fracturing (HF). The NFMMDP Preliminary Environmental Assessment analyzed traffic assuming completion with nitrogen foam HF. GELLC has revised its proposal to use slickwater HF as the completion method instead of nitrogen foam HF. With nitrogen foam HF, truck traffic for water delivery was not included because all water would have been sourced from the existing Hotchkiss Water Storage Facility. The currently proposed slickwater HF would require a greater volume of water. GELLC proposes to drill, complete, and operate 35 horizontal wells from one existing well pad, one existing pad to be expanded, and three new well pads, and to construct associated access roads and gathering pipelines. Development is proposed to span 4 years. Existing support facilities would be used for water transfer, storage, and disposal including the Hotchkiss Water Storage Facility, the existing DGU 1289 #20-12 well pad, the IPU 1291 #13-24 Support Pad, and two water disposal wells (Hotchkiss 1289 #18-22D and Allen 1291 #12-13D). GELLC proposes five wells in the first year and six wells in the second year, with one drilling rig and one completion rig operating at any one time. This rate would be expanded to 12 wells in each of the third and fourth years, contingent on the ability to secure additional water sources and water storage facilities. The life of the project is estimated to be 30 years. Existing U.S. and state highways, county roads, and National Forest System Roads would be used to access the project area. These roads are shown on Map C-1. Within the project area, existing county, National Forest System, and private roads would be used to access the well pads and the existing Hotchkiss Water Storage Facility. Two road options have been identified for accessing the proposed Sheep Park Unit (SPU) Federal 1190 #20 well pad, depending on GELLC’s ability to use existing access across private land (Option 1) instead of constructing a new road on National Forest System land (Option 2). Table C-1 lists the length of each type of road used by the Proposed Action within the project area. Roads that would be used within the NFMMDP project area are shown on Map C-2. Table C-1. Road Length by Road Type Proposed for the NFMMDP

Road Options Distance (miles) Option 1 for SPU Federal 1190 #20 Access Existing Roads 19.30 Existing Roads Requires Upgrade 0.09 New Roads 2.45 Total 21.84 Option 2 for SPU Federal 1190 #20 Access Existing Roads 17.50 Existing Roads Requires Upgrade 0.00 New Roads 4.21 Total 21.71

2. ACCESS ROUTES 2.1 PRIMARY ACCESS ROUTES IN THE PROJECT AREA Road types, or functional classifications, describe the functions that roads serve in facilitating traffic flow within a transportation network. Principal arterial roads such as Interstate, U.S. highways, and state highways accommodate high traffic volumes and have limited access. Minor arterial roads such as county roads connect rural and other small population centers with principal arterials. Collector roads such as county and National Forest System roads provide primary access to large blocks of land, and are generally two lanes wide. Table C-2 lists the arterial and collector roads that either would be used to access the project area or are located within the project area. The table also indicates road surface type and identifies the party responsible for maintenance of each road. Table C-2. Primary Access Routes Maintenance Road Name Road Type Surface Type Responsible Party Gravel surface treated Gunnison County Road 265 Collector Gunnison County with magnesium chloride State Highway 133 Arterial Pavement CDOT 1 State Highway 92 Arterial Pavement CDOT U.S. Highway 50 Arterial Pavement CDOT 1 CDOT = Colorado Department of Transportation.

2.2 ACCESS OVERVIEW U.S Highway 50 (US 50), State Highway (SH) 92, SH 133, Gunnison County Road (CR) 265, and National Forest System Road (NFSR) 265 would be the primary access route to the project area for heavy- and light-trucks and passenger vehicles. From the north, access to the project area would follow SH 133 south from Carbondale for 35 miles and across McClure Pass. Between Carbondale and the town of Hotchkiss, SH 133 is part of the West Elk Loop Scenic and Historic Byway. From the south, access to the project area from Delta would continue east on SH 92 for 21 miles to Hotchkiss, then northeast on SH 133 approximately 29 miles to CR 265. Most project-related traffic is expected to access the project area from the south. From SH 133, the access route would follow CR 265 northwest for approximately 5 miles to the NFMMDP project area boundary. Inside the project area, NFSRs 265, 704, 844, and 851 would be the primary roads used to access well pads (see Map C-2). Additional unpaved NFSRs, Gunnison and Delta county roads, and private roads in the project area could also be used to access individual well pads. The existing Hotchkiss Water Storage Facility would be filled with water from sources within the project area (coalbed methane wells, recycled water, State-authorized withdrawals from Muddy Creek and West Muddy Creek) and would not require trucking outside the project area. Water from the creeks would be pumped from the withdrawal points and delivered by surface line either directly to the Hotchkiss Water Storage Facility or into the existing gathering system. If needed, water may also be withdrawn from other area creeks in accordance with local and state regulations. Water would be transferred from the Hotchkiss Water Storage Facility to the well pads via the Sheep Gas Gathering System. No trucking would be required for water delivery within the project area because water would be delivered via existing water lines. It is anticipated that 50,000 barrels per day would be required for well completions over a 10 day period for each well. A portion of the water used for drilling, completion, and dust control during the first and potentially the second year is expected to be acquired and trucked from the City of Delta. Water obtained from the City

of Delta would be sourced from a hydrant located at an empty subdivision north of Delta along US 50. Water would be transported in 120-barrel trucks to storage at the existing DGU 1289 #20-12 well pad. From the City’s water take point, trucks would travel south on 1525 Road to US 50 and east and south on US 50 approximately 2.1 miles to the intersection with SH 92 in the City of Delta. From Delta, water trucks would travel 20.7 miles on SH 92 to Hotchkiss and then 28.5 miles on SH 133 to the DGU 1289 #20-12 well pad. Additional water used for drilling, completion, and dust control would be withdrawn from the North Fork of the Gunnison River under the mine’s existing water right and transported to the project area (existing IPU 1291 #13-24 support pad) through a surface pipeline. Total length of the surface pipeline would be 7.5 miles, with 5.7 miles on private land, of which 0.86 mile would be laid cross-country instead of along an existing road. Water would be transported from the IPU 1291 #13-24 support pad to individual well pads via GELLC’s existing pipeline system. Sand for use as a proppant in hydraulic fracturing would be transported by train from the City of Fruita, Colorado, to the Elk Creek Mine, where it would offloaded and temporarily stockpiled. During well completions, sand would be delivered to active well pads by truck. This haulage of sand would travel 17.0 miles on SH 133 to Gunnison CR 265 before turning into the project area. 3. ROAD CONSTRUCTION, USE, AND MAINTENANCE

3.1 EXISTING ROADS GELLC proposes to use approximately 19.3 miles of existing roads within the NFMMDP project area under Option 1 for access to SPU Federal 1190 #20 (17.5 miles under Option 2 for access to SPU Federal 1190 #20). These roads are identified in Table C-1 and Map C-2 above. Table C-2 indicates the party responsible for road maintenance.

3.2 ROAD CONSTRUCTION Under Option 1, approximately 2.45 miles of new resource roads would be required to access the proposed well pads from existing local roads (4.22 miles under Option 2). The new resource roads would be constructed at the same time as the respective well pad construction. The resource roads could require up to a 30-foot width for construction. All existing roads would be maintained in a condition as good as or better than pre-project conditions to ensure safe use year-round. This may include snow removal on new or existing roads or road segments serving active well pads. In coordination with the Forest Service, a pre-use road conditions assessment would be conducted for affected National Forest System roads. If any roadwork is required, a work schedule would be submitted to the Paonia District Ranger prior to initiation. Repairs would be made under agency specifications. All road design packages for roads open to the public would conform to American Association of State Highway and Transportation Officials (AASHTO) Guidelines for Geometric Design of Very Low Volume Local Roads (Average Annual Daily Traffic [AADT] of less than 400 roundtrips). The initial disturbance width for new access roads would average 30 feet, with a long-term disturbance of 24 feet (14 feet of driving surface and 5 feet for ditches on each side). All new roads would be constructed within the Federal leases and would be authorized under the Application for Permit to Drill (APD)/Surface Use Plan of Operations (SUPO) except for 2,348 feet of the Option 2 access road leading to the proposed SPU Federal 1190 #20 well pad, north of the Unit. The portion of road not within the Federal lease would require authorization from the Forest Service under a Surface Use Authorization (SUA). Where new road construction would occur on National Forest System lands, final design of road construction would be reviewed and approved by the District Ranger and/or Forest Service engineer. For

new road construction on lands managed by the Bureau of Land Management (BLM), site-specific design measures consistent with a resource road would be incorporated and would reflect the road standards required by BLM H-9113-1 Road Design Handbook. Site-specific road design measures would consider grades, soils, and local hydrology. Details of road design and construction would be provided with each APD. New access roads would be crowned or sloped; drained with ditches, culverts and/or water dips; and constructed, sized, and surfaced with gravel to minimize erosion and sediment transport and provide safe travel during all-weather conditions. Water outlets and roadside ditches would incorporate best management practices (BMPs) such as riprap, sediment catchments, and anchored check structures to slow water velocity. Where needed, culverts or drainage crossings would be designed for a 25-year storm frequency unless BLM or Forest Service specify a larger culvert (maximum 100-year storm frequency) without development of a static head at the pipe inlet. When saturated soil conditions exist on access roads, or when rutting deepens past 4 inches, construction and travel would halt until the road material dries out, is frozen sufficiently, or is otherwise brought to standards (e.g., with additional gravel) for resource protection. Gravel would be used to surface all new access roads, including on private lands where needed to ensure safe travel during development of Federal fluid minerals. During the life of the project, GELLC would provide timely maintenance and cleanup of roads. A regular schedule for maintenance would include, but not be limited to, dust abatement, blading, placement of additional gravel, cleanout of drainage water bars and culverts, and reconstruction of the crown and slope. GELLC has an agreement with Gunnison County to apply magnesium chloride on CR 265. However, magnesium chloride or other dust-suppressing chemical would not be applied on National Forest System roads unless approved by the Forest Service. Dust abatement would be implemented as needed to prevent fugitive dust from vehicular traffic. The BLM/Forest Service may direct GELLC to change the level and type of treatment (watering or application of various dust agents, surfactants, and road surfacing material) if dust abatement measures are observed to be insufficient to prevent fugitive dust. 4. TRAFFIC LEVELS

4.1 DEVELOPMENT TRAFFIC Table C-3 provides an estimate of the total traffic requirements for development of a single well. Table C-4 provides an estimate of peak daily traffic. Peak traffic would occur between August 1 and November 30 for 10 days during well completion and would occur five times during 2019 (five wells proposed) for a total of 50 days. Traffic associated with rig mobilization and demobilization as well as traffic for delivery of hydraulic fracturing tanks are not included in the peak traffic because that traffic would occur before and after well completion. Table C-5 lists the number of water and sand trucks required to support completion on a daily basis over a 10 day delivery period (peak traffic). The water truck traffic estimate is based on up to 5,000 barrels of water being trucked from the City of Delta to the DGU 1289 #20-12 well pad; 23,000 barrels of water per day being delivered to the project area via surface pipeline from the Elk Creek Mine; and 22,000 barrels per day being obtained from within the Hotchkiss Water Storage Facility within the project area. The estimated truck traffic for sand delivery is based on 2,100,000 pounds of sand per day being delivered from the Elk Creek Mine to the project area (CR 265).

Table C-3. Estimated Vehicle Roundtrips per Activity for Construction of a Single Well Light Heavy Total Number Activity Vehicle Vehicle Vehicle Of Days Roundtrips Roundtrips Roundtrips Well Pad, Road, and Gathering Line Construction Equipment Mobilization/Demobilization 2 0 6 1 6 Pipe Delivery 1 0 14 per day 14 Construction 14 6 per day 2 1 per day 98 Dust Control 3 17 0 1 per day 17 Total 135 Drilling Drill Rig Mobilization/Demobilization 10 4 6 per day 25 1 85 Well Drilling 20 10 per day 5 1 per day 220 Supply, Equipment, Miscellaneous 20 1 per day 1 per day 40 Deliveries Dust Control 3 25 0 1 per day 25 6 Total 370 Completion Completion Rig 6 7 6 per day 10 1 46 Mobilization/Demobilization Hydraulic Fracturing Tank Delivery 14 0 20 per day 8 280 Water Delivery 10 0 42 per day 9 420 47 per day Sand Delivery 10 0 470 10 Hydraulic Fracturing 14 10 per day 1 per day 154 Supply, Equipment, Miscellaneous 14 1 per day 1 per day 28 Deliveries Dust Control 3 17 0 1 per day 17 Total 1,415 Single Well Development Total 1,920 1 Assumes that vehicles enter the project area once, remain onsite, and leave the project area once. 2 Includes two crew trucks, two welding trucks, and two miscellaneous trucks. 3 Assumes that road dust is controlled during pad/road/gathering line construction, drilling, and completion on an as-needed basis for 122 days between the beginning of June and the end of September. 4 Includes 5 days for drill rig set-up and 5 days for drill rig-take down. The drill rig would enter the project area once and remain within the project area throughout the drilling season. 5 Assumed that drill rig workers will stay on location. Includes two shifts per day with five additional light vehicles per shift. 6 Based on average number of days. 7 Includes 3 days for completion rig set-up and 3 days for completion rig take-down. 8 Includes 140 hydraulic fracturing tank deliveries across 7 days before completion of the first well and 140 truck removals across 7 days after completion of the final well of the season. 9 Includes trucks hauling a total of 5,000 barrels of water per day from the City of Delta’s water supply to the DGU 1289 #20-12 well pad. 10 Assumes that 21,000,000 pounds of sand are delivered to the project area from the Elk Creek Mine in 45,000 pound capacity trucks.

Table C-4. Estimated Peak Vehicle Traffic per Day During Well Completion Light Heavy Total Activity Vehicle Vehicle Vehicle Roundtrips Roundtrips Roundtrips Water Delivery 0 42 42 Sand Delivery 0 47 47 Hydraulic Fracturing 10 1 11 Supply, Equipment, Miscellaneous Deliveries 1 1 2 Total 11 91 102

Table C-5. Daily Water and Sand Truck Traffic to Support HF Per-Well Completions

Daily One-Way Truck Trips Daily Roundtrip Truck Trips Road Name/Segment 3 Water 1 Sand 2 Total Water Sand Total U.S. Highway 50 Water Source to Delta (MP 70.92 to MP 84 0 84 42 0 42 71.43) 3 State Highway 92 84 0 84 42 0 42 Delta to Hotchkiss (MP 0.0 to 20.72) State Highway 133 Hotchkiss to Elk Creek Mine (MP 0.0 to 84 0 84 42 0 42 10.56) State Highway 133 Elk Creek Mine to DGU 1289 #20-12 84 94 178 42 47 89 Water Storage (MP 10.56 to 14.85) State Highway 133 DGU 1289 #20-12 Water Storage to 0 94 94 0 47 47 NFMMDP Project Area (CR 265) (MP 14.85 to MP 21.45) 1 Based on 5,000 barrels of water trucked per day in 120-barrel trucks from the City of Delta. 2 Based on 21,000,000 pounds of sand per well completion, transported from the Elk Creek Mine, with 45,000 pounds hauled per truck. 3 Mileposts are approximate, based on highway details provided by the Colorado Department of Transportation. (CDOT 2018).

4.2 PRODUCTION TRAFFIC Following construction, average daily traffic associated with long-term production of the wells is estimated to include four pumper vehicles per day. Additional maintenance visits to well pads would also be required on an intermittent basis. Workovers would occur when needed once wells are in production and possibly once every 5 years. Traffic associated with workovers would be similar to traffic required for drilling. 5. REFERENCES Bureau of Land Management and Forest Service (BLM and Forest Service). 2007. Surface Operating Standards and Guidelines for Oil and Gas Exploration and Development. Gold Book. Fourth Edition.

Colorado Department of Transportation (CDOT). 2018. Online Transportation Information System (OTIS). Highway Data Explorer. Accessed online at: dtdapps.coloradodot.info/Otis/HighwayData#/us/0/0.

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APPENDIX D

Air Quality Impact Analysis

North Fork Mancos Master Development Plan Gunnison Energy LLC

Prepared for:

Bureau of Land Management Colorado River Valley Field Office and U.S. Forest Service Grand Mesa, Gunnison, and Uncompahgre National Forests

February 2019

CONTENTS

1. Affected Environment ...... 1 1.1 Regional Air Quality ...... 1 1.2 Regional Climate ...... 1 1.3 Overview of Regulatory Environment ...... 4 1.3.1 Ambient Air Quality Standards ...... 4 1.3.2 Hazardous Air Pollutants ...... 6 1.3.3 Prevention of Significant Deterioration ...... 7 1.3.4 Air Quality Related Values ...... 8 1.3.5 New Source Performance Standards ...... 10 1.3.6 National Emission Standards for Hazardous Air Pollutants ...... 11 1.3.7 Non-Road Engine Tier Standards ...... 11 1.3.8 Colorado Oil and Gas Permitting Guidance ...... 11 1.4 Greenhouse Gases and Climate Change ...... 12 1.5 Monitored Air Pollutant Concentrations ...... 17 1.6 Monitored Visibility ...... 18 1.7 Monitored Atmospheric Deposition ...... 18 2. Environmental Consequences ...... 19 2.1 Proposed Action ...... 19 2.1.1 Near-Field Modeling ...... 19 2.1.2 Far-Field Modeling ...... 20 2.1.3 Impact Significance Criteria ...... 21 2.1.4 Emission Inventory Development ...... 21 2.1.5 Modeling Results ...... 23 2.1.6 Regional Climate Change ...... 30 3. Cumulative ...... 30 3.1 Regional Ozone and Cumulative Air Quality and AQRV Analyses ...... 30 3.2 Cumulative Air Quality and AQRV Impacts ...... 36 3.2.1 Air Quality Impacts ...... 36 3.2.2 Air Quality Related Value Impacts ...... 38 3.2.3 Monitoring ...... 40 3.2.4 Regional Climate Change – Greenhouse Gas Impacts...... 40 3.3 Social Costs of Carbon and Social Costs of Methane (SCC/SCM) ...... 42 4. References ...... 43

FIGURES Figure D-1. McClure Pass, Colorado - Meteorological Data Windrose ...... 3 Figure D-2. 2011 Ozone DVB (top left), 2025 Ozone DVF (top right), and 2025 DVF – 2011 Ozone DVB Differences Calculated Using MATS for the CARMMS 2025 High Development Scenario ...... 33 Figure D-3. Fourth Highest Daily Maximum 8-hour Ozone Concentrations for the 2011 Base Case (top left), CARMMS 2025 High Development Scenario (top right), and 2025 Minus 2011 Differences (bottom) ...... 34 Figure D-4. Contribution to Fourth Highest Daily Maximum Ozone Concentrations Due to Federal Land Oil and Gas Emissions within the UFO Planning Area for the CARMMS 2025 High Development Scenario ...... 35

MAPS Map D-1. Air Quality PSD Class I and Sensitive Class II Areas in Relation to the Project Area ...... 9

TABLES Table D-1. Mean Monthly Temperature Ranges, Total Precipitation, and Total Snowfall ...... 2 Table D-2. Wind Direction Frequency Distribution, McClure Pass, Colorado, 2009 to 2013 ...... 2 Table D-3. Wind Speed Distribution, McClure Pass, Colorado, 2009 to 2013 ...... 3 Table D-4. Ambient Air Quality Standards ...... 5 Table D-5. Acute RELs (1-Hour Exposure) ...... 6 Table D-6. Non-Carcinogenic Air Toxics RfCs (Annual Average) ...... 7 Table D-7. PSD Class I and Class II Increments ...... 7 Table D-8. Background Ambient Air Quality Concentrations ...... 17 Table D-9. Gothic Site N and S Deposition Values (kg/ha-yr), 2006 to 2015 ...... 18 Table D-10. Background ANC Values for Acid Sensitive Lakes...... 19 Table D-11. Development Emissions ...... 21 Table D-12. Annual Production Emissions ...... 22 Table D-13. GHG Emissions ...... 23 3 Table D-14. Maximum Modeled Pollutant Concentration Impacts (µg/m ) from Well Development Activities ...... 23 3 Table D-15. Maximum Modeled Pollutant Concentration Impacts (µg/m ) from Well Production Activities ...... 24 Table D-16. Maximum Modeled 1-Hour HAP Concentration Impacts (µg/m3) ...... 25 Table D-17. Maximum Modeled Annual HAP Concentration Impacts (µg/m3) ...... 25 Table D-18. Long-term Modeled MLE and MEI Cancer Risk Analyses ...... 26 Table D-19. Maximum Modeled Pollutant Concentrations at PSD Class I and Sensitive Class II Areas (µg/m3) ...... 27 Table D-20. Maximum Visibility Impacts at Class I and Sensitive Class II Areas ...... 29 Table D-21. Maximum Nitrogen Deposition Impacts at Class I and Sensitive Class II Areas ...... 29 Table D-22. Oil and Gas Emissions (tpy) from the Colorado BLM Planning Areas, SUIT Land and Mancos Shale for CARMMS 2025 High Development Scenario ...... 31 Table D-23. Modeled Cumulative Pollutant Concentrations (CARMMS 2025 High Development Scenario) at PSD Class I and Sensitive Class II Areas (µg/m3) ...... 36 Table D-24. Cumulative Visibility Results (Δdv) for Worst 20 percent Visibility Days at PSD Class I and Sensitive Class II Areas for the Base Year (2011) and 2025 High Development Scenario, All Emissions and Contributions from RFD Sources ...... 38 Table D-25. Cumulative Visibility Results (Δdv) for Best 20 percent Visibility Days at PSD Class I and Sensitive Class II Areas for the Base Year (2011) and 2025 High Development Scenario, All Emissions and Contributions from RFD Sources ...... 39 Table D-26. Cumulative RFD Nitrogen and Sulfur Deposition Impacts (CARMMS 2025 High Development Scenario) at PSD Class I and Sensitive Class II Areas ...... 39 Table D-27. Cumulative RFD Impacts on Lakes (CARMMS 2025 High Development Scenario) within the Class I and Sensitive Class II Areas ...... 40

ABBREVIATIONS AND ACRONYMS ºF degrees Fahrenheit Δdv delta-deciviews µeq/L microequivalents per liter µg/m3 micrograms per cubic meter 3SAQS Three-State Air Quality Study amsl above mean sea level ANC Acid Neutralizing Capacity AEGL Acute Exposure Guideline Level AEGL-1 Acute Exposure Guideline Level for Mild Effects AEGL-2 Acute Exposure Guideline Level for Moderate Effects APCD Air Pollution Control Division AQRVs air quality related values AR5 IPCC Fifth Assessment Report BACT Best Available Control Technology bcf billion cubic feet BTEX benzene, toluene, ethyl benzene, and xylene CAA Clean Air Act CAAQS Colorado Ambient Air Quality Standards CAMx Comprehensive Air-quality Model with extensions CARMMS Colorado Air Resource Management Modeling Study CASTNET Clean Air Status and Trends Network CCR Code of Colorado Regulations CDPHE Colorado Department of Public Health and Environment CFR Code of Federal Regulations CH4 methane CO carbon monoxide CO2 carbon dioxide CO2e carbon dioxide equivalent DATs deposition analysis thresholds DGU Deadman Gulch Unit dv deciview DVB base year DVF future year EPA U.S. Environmental Protection Agency FLAG Federal Land Managers Air Quality Related Values Work Group FLPMA Federal Land Policy and Management Unit GHGs greenhouse gases GWP Global Warming Potential HAPs hazardous air pollutants HNO3 nitric acid ICE internal combustion engine IMPROVE Interagency Monitoring of Protected Visual Environments IPCC Intergovernmental Panel on Climate Change IPU Iron Point Unit kg/ha-yr kilogram per hectare per year km kilometer LOP Life-of-Project m, m3 meters, cubic meters MATS Modeled Attainment Test Software

iii

MEI maximum exposed individual MLE most likely exposure MMcfd million cubic feet per day MMIF Mesoscale Model Interface Program MMT million metric tons mph miles per hour N nitrogen N2O nitrous oxide NAAQS National Ambient Air Quality Standards NADP National Atmospheric Deposition Program NASA National Aeronautics and Space Administration NCA National Climate Assessment NEPA National Environmental Policy Act NESHAPs National Emission Standards for Hazardous Air Pollutants NFMMDP North Fork Mancos Master Development Plan NH3, NH4 ammonia, ammonium NIOSH National Institute for Occupational Safety and Health NO2 nitrogen dioxide NO3 nitrate NOx nitrogen oxides NOAA National Oceanic and Atmospheric Administration NPS National Park Service NSPS New Source Performance Standards NTN National Trends Network O3 ozone ONRR Office of Natural Resources Revenue PGM photochemical grid model ppb parts per billion ppm parts per million PM2.5 particulate matter less than 2.5 microns in effective diameter PM10 particulate matter less than 10 microns in effective diameter PSD Prevention of Significant Deterioration RACT Reasonably Achievable Control Technology RAWS Remote Automated Weather Station RCP Representative Concentration Pathway RELs Reference Exposure Levels RfCs Reference Concentrations for Chronic Inhalation RFD Reasonable Foreseeable Development S sulfur SI spark ignition SO2 sulfur dioxide SO4 sulfate SPU Sheep Park II Unit SUIT Southern Ute Indian Tribe SVR Standard Visual Range TGU Trail Gulch Unit tpy tons per year URF unit risk factors VOC volatile organic compound WRCC Western Regional Climate Center WRF Weather Research and Forecasting

1. AFFECTED ENVIRONMENT Regional air quality is influenced by a combination of factors including climate, meteorology, the magnitude and spatial distribution of local and regional air pollution sources, and the chemical properties of emitted pollutants. Within the lower atmosphere, regional and local scale air masses interact with regional topography to influence atmospheric dispersion and transport of pollutants. The following sections summarize the climatic conditions and existing air quality within the project area and surrounding region. 1.1 REGIONAL AIR QUALITY The North Fork Mancos Master Development Plan (NFMMDP) project area is located in Colorado in the northwestern corner of Gunnison County and on the eastern edge of Delta County, and is within the Central Mountains and Western Slope regions for air quality planning (Colorado Department of Public Health and Environment [CDPHE] 2017). The Central Mountains Region covers 12 counties including Gunnison County, in the central area of Colorado with the Continental Divide. The Western Slope Region includes nine counties, including Delta County, on the far western border of Colorado. Air quality concerns in these regions are primarily from impacts related to particulates from wood burning and road dust, and impacts from ranching, agriculture, mining, energy development, and tourism. 1.2 REGIONAL CLIMATE In the project area region of western Colorado, the local climate is dominated by elevation and topography given the combination of canyons, plateaus, and mountains (Colorado Climate Center 2003). The nearest meteorological measurements were collected at Redstone, Colorado (1979 to 1994), approximately 10 miles northeast of the project area at an elevation of 8,070 feet above mean sea level (amsl) (Western Regional Climate Center (WRCC 2017a). The annual average total precipitation at Redstone, Colorado is 27.7 inches, with annual totals ranging from 20.2 inches (1987) to 40.4 inches (1985). Precipitation is greatest in the spring and fall months. An average 169.4 inches of snow falls during the year (annual high of 273.8 inches during the 1992-1993 winter) and occurs from fall through spring, with the greatest monthly mean snowfall being 32.4 inches for March. The region has cool temperatures, with the average daily temperature (in degrees Fahrenheit, ˚F) ranging between 8˚F and 33˚F in January and between 44˚F and 76˚F in July. Minimum and maximum temperatures have ranged from -29˚F (1985) to 93˚F (1991). The frost-free period generally occurs from early June to mid-September. Table D-1 shows the mean monthly temperature ranges and total precipitation amounts. The closest comprehensive wind measurements were collected at the McClure Pass Colorado Remote Automated Weather Station (RAWS) (WRCC 2017b), located approximately 10 miles northeast of the project area. Although local wind patterns in mountainous areas mostly controlled by local topography, the McClure Pass site is located at 9,018 feet amsl in rolling terrain and can be used to describe typical wind patterns in the project area. Tables D-2 and D-3 provide the wind direction distribution and wind speed distribution at that site in a tabular format. From this information, it is evident that winds originate from the southwest to west-northwest nearly 42% of the time. The annual mean wind speed at the McClure Pass site is 4.5 miles per hour (mph). A windrose for the McClure Pass site is provided on Figure D-1. Note that a BLM air quality and meteorological station was installed at Paonia High School in April 2018. However, the station has not collected sufficient data to compile a comprehensive and representative dataset for the area (Cook 2018).

Table D-1. Mean Monthly Temperature Ranges, Total Precipitation, and Total Snowfall 1

Average Temperature Total Precipitation Total Snowfall Month Range (˚F) (inches) (inches) January 8-33 1.8 26.0 February 12-36 2.4 29.9 March 17-43 3.1 32.4 April 25-51 2.0 12.1 May 32-61 2.3 5.3 June 39-72 1.5 0.5 July 44-76 2.2 0.0 August 44-75 1.7 0.0 September 37-67 3.0 0.5 October 28-55 3.0 6.9 November 18-39 2.6 26.4 December 9-32 2.0 29.5 ANNUAL 39.6 (mean) 27.7 169.4 1 Source: WRCC 2017a.

Table D-2. Wind Direction Frequency Distribution, McClure Pass, Colorado, 2009 to 2013 1

Wind Direction Frequency (percent) Calm 13.7 N 2.0 NNE 2.1 NE 3.0 ENE 4.7 E 9.6 ESE 9.5 SE 3.6 SSE 1.9 S 1.7 SSW 2.7 SW 7.9 WSW 10.5 W 15.7 WNW 7.8 NW 2.3 NNW 1.5 Source: WRCC 2017b.

Table D-3. Wind Speed Distribution, McClure Pass, Colorado, 2009 to 20131

Wind Speed (mph) Frequency (percent) < 1.3 (Calm) 13.7 1.3 – 4 26.4 4 – 8 12.9 8 – 13 1.4 13 – 19 0.1 19 – 25 0.5 Greater than 25 0.0 1 Source: WRCC 2017b.

Figure D-1. McClure Pass, Colorado - Meteorological Data Windrose Source: WRCC 2017b

1.3 OVERVIEW OF REGULATORY ENVIRONMENT Air quality impacts from pollutant emissions are limited by regulations, standards, and implementation plans established under the Clean Air Act (CAA), as administered by the CDPHE Air Pollution Control Division (APCD) under authorization of the U.S. Environmental Protection Agency (EPA). The APCD is the primary air quality regulatory agency responsible for determining potential impacts once detailed industrial development plans have been made, and those development plans are subject to applicable air quality laws, regulations, standards, control measures, and management practices. Unlike the conceptual “reasonable, but conservative” engineering designs used in National Environmental Policy Act (NEPA) analyses, any air quality preconstruction permitting demonstrations required by the APCD would be based on site-specific, detailed engineering values, which would be assessed in the CDPHE permit application review. Any proposed facility that meets the requirements set forth under division permit regulations is subject to the Colorado permitting and compliance processes. Federal air quality regulations adopted and enforced by the CDPHE-APCD limit incremental emission increases to specific levels defined by the classification of air quality in an area. The Prevention of Significant Deterioration (PSD) program is designed to limit the incremental increase of specific air pollutant concentrations above a legally defined baseline level. Incremental increases occurring in PSD Class I areas are strictly limited, while increases allowed in Class II areas are less strict. Under the PSD program, Class I areas are protected by Federal Land Managers through management of Air Quality Related Values (AQRVs) such as visibility, aquatic ecosystems, flora, fauna, and others. Areas throughout the region not designated as PSD Class I are classified as Class II. Federal Land Managers can designate specific Class II areas that they manage as “sensitive” Class II areas, based on their own criteria, and request that PSD Class I level air quality analyses be included for these areas. The 1977 CAA amendments established visibility as an AQRV for Federal Land Managers to consider. The 1990 CAA amendments contain a goal of improving visibility within PSD Class I areas. The Regional Haze Rule, finalized in 1999, requires States, in coordination with Federal agencies and other interested parties, to develop and implement air quality protection plans to reduce the pollution that causes visibility impairment. Regulations and standards that limit permissible levels of air pollutant concentrations and emissions and are relevant to the project air impact analysis include:  National Ambient Air Quality Standards (NAAQS) (40 Code of Federal Regulations - CFR Part 50 and 50) and Colorado Ambient Air Quality Standards (CAAQS) (5 Code of Colorado Regulations – CR-1001-14)  Hazardous Air Pollutants (HAPs)  PSD (40 CFR Part 51.166)  New Source Performance Standards (NSPS) (40 CFR Part 60)  National Emission Standards for Hazardous Air Pollutants (NESHAPs) (40 CFR Part 63)  Non-Road Engine Tier Standards (40 CFR Part 89)  Colorado Oil and Gas Permitting Guidance Each of these regulations is further described in the following sections.

1.3.1 Ambient Air Quality Standards The CAA requires the EPA to set NAAQS for pollutants considered to endanger public health and the environment. The EPA has developed NAAQS for seven criteria pollutants: nitrogen dioxide (NO2), carbon monoxide (CO), sulfur dioxide (SO2), particulate matter less than 10 microns in effective diameter (PM10), particulate matter less than 2.5 microns in effective diameter (PM2.5), ozone (O3), and lead. There

would not be any lead emissions from project sources and therefore, lead impacts are not discussed in this document. There are two types of NAAQS; primary standards that prescribe limits on ambient levels of these pollutants in order to protect public health, including the health of sensitive groups, and secondary standards that provide public welfare protection, including protection against decreased visibility and damage to animals, crops, vegetation, and buildings. States typically adopt the NAAQS but may also develop State-specific ambient air quality standards for certain pollutants. The NAAQS and the CAAQS are summarized in Table D-4. Table D-4. Ambient Air Quality Standards

Pollutant Averaging Time Primary/Secondary NAAQS CAAQS 35 ppm 1-hour 1 Primary * (40,000 µg/m3) CO 9 ppm 8-hour 1 Primary * (10,000 µg/m3)* 100 ppb 1-hour 2 Primary * (188 µg/m3) NO2 Primary and 53 ppb Annual 3 * Secondary (100 µg/m3) Primary and 70 ppb Ozone 8-hour 4 * Secondary (137 µg/m3)

2 Primary and 3 PM10 24-hour 150 µg/m * Secondary Primary and 24-hour 5 35 µg/m3 * Secondary PM2.5 Annual 6 Primary 12 µg/m3 * Annual 6 Secondary 15 µg/m3 * 75 ppb 1-hour 7 Primary * (196 µg/m3) 0.5 ppm SO 3-hour 1 Secondary * 2 (1,300 µg/m3) Primary and 3-hour 1 -- 700 µg/m3 Secondary Source: 40 CFR Part 50. 1 No more than one exceedance per year. 2 th An area is in compliance with the standard if the 98 percentile of daily maximum 1-hour NO2 concentrations in a year, averaged over 3 years, is less than or equal to the level of the standard. 3 Annual arithmetic mean. 4 An area is in compliance with the standard if the fourth-highest daily maximum 8-hour ozone concentrations in a year, averaged over 3 years, is less than or equal to the level of the standard. 5 An area is in compliance with the standard if the eighth highest 24-hour PM2.5 concentration in a year, averaged over 3 years, is less than or equal to the level of the standard. 6 Annual arithmetic mean, averaged over 3 years 7 th An area is in compliance with the standard if the 99 percentile of daily maximum 1-hour SO2 concentrations in a year, averaged over 3 years, is less than or equal to the level of the standard. Bold indicates the units in which the standard is defined. * Colorado maintains or has adopted the NAAQS with the exception of the NAAQS for SO2 concentrations averaged over a 3-hour period. Colorado has a specific ambient air quality standard for SO2 3-hour averaged concentrations.

The ambient air quality standards are shown in units of parts per million (ppm), parts per billion (ppb), and micrograms per cubic meter (µg/m3) for purposes of providing the standards as written in the corresponding regulation, and for comparison with ambient pollutant concentrations. Although specific air quality monitoring has not been conducted within the project area, all of Delta and Gunnison counties are currently designated as “attainment” by the CDPHE for all criteria pollutants (CDPHE 2017).

1.3.2 Hazardous Air Pollutants HAPs are pollutants that are known or suspected to cause cancer or other serious health effects, such as reproductive effects or birth defects, or adverse environmental effects. No ambient air quality standards exist for HAPs, instead, emissions of these pollutants are subject to a variety of regulations that target the specific source class and industrial sectors for stationary, mobile, and product use/formulations. Sources of HAPs from project operations include well-site production emissions (benzene, toluene, ethyl benzene, xylene, n-hexane, and formaldehyde). For the air quality analysis, short-term (1-hour) HAP concentrations are compared to acute Reference Exposure Levels (RELs) available from EPA’s Air Toxics Database (EPA 2018a) and shown in Table D- 5. RELs are defined as concentrations at or below which no adverse health effects are expected. No RELs are available for ethyl benzene and n-hexane; instead, the Acute Exposure Guideline Levels (AEGL) for mild effects (AEGL-1) or moderate effects (AEGL-2) values are used, and these values and were also obtained from EPA's Air Toxics Database (EPA 2018a). The AEGL-1 value is used for ethyl benzene and the AEGL-2 value is used for n-hexane. The AEGL values are 1-hour exposures that represent threshold levels for the general public. Table D-5. Acute RELs (1-Hour Exposure)

Air Toxic REL (µg/m3) Benzene 27 1 Toluene 37,000 1 Ethyl benzene 140,000 2 Xylene 22,000 1 n-Hexane 10,000,000 2 Formaldehyde 55 1 1 Source: EPA Air Toxics Database, Table 2 (EPA 2018a). 2 No REL available for these air toxics. Values shown are Acute Exposure Guideline Levels for mild effects (AELG-1) (ethyl benzene) and moderate effects (AEGL-2) (n-hexane) from EPA Air Toxics Database, Table 2 (EPA 2018a).

Long-term exposure to air toxics are compared to Reference Concentrations for Chronic Inhalation (RfCs). An RfC is defined by the EPA as the daily inhalation concentration at which no long-term adverse health effects are expected. RfCs exist for both non-carcinogenic and carcinogenic effects on human health (EPA 2018b). Annual modeled air toxics concentrations for all air toxics emitted are compared directly to the non-carcinogenic RfCs shown in Table D-6. Long-term exposures to emissions of suspected carcinogenic HAPs (benzene, ethyl benzene, and formaldehyde) are also evaluated based on estimates of the increased latent cancer risk over a 70-year lifetime.

Table D-6. Non-Carcinogenic Air Toxics RfCs (Annual Average)

Non-Carcinogenic RfC1 Air Toxic (µg/m3) Benzene 30 Toluene 5,000 Ethyl benzene 1,000 Xylene 100 n-Hexane 700 Formaldehyde 9.8 1 EPA Air Toxics Database, Table 1 (EPA 2018b).

1.3.3 Prevention of Significant Deterioration The PSD program is designed to limit the incremental increase of specific air pollutant concentrations above a legally defined baseline level. All areas of the country are assigned a classification that describes the degree of degradation to the existing air quality allowed to occur within the area under the PSD permitting rules. PSD Class I areas are areas of special national or regional natural, scenic, recreational, or historic value, and very little degradation in air quality is allowed by strictly limiting industrial growth. PSD Class II areas allow for reasonable industrial/economic expansion. Areas such as national parks, national wilderness areas, and national monuments are designated as PSD Class I areas, and air quality in these areas is protected by allowing only slight incremental increases in pollutant concentrations. The PSD Class I area nearest to the project area is the West Elk Wilderness Area, which is approximately 14 kilometers (km) to the southeast. In a PSD increment analysis, impacts from proposed emissions sources are compared with the allowable limits on increases in pollutant concentrations, which are called PSD increments. PSD increments are established for NO2, PM10, PM2.5, and SO2. These increments are shown in Table D-7. The project area is classified as PSD Class II, where less stringent limits on increases in pollutant concentrations apply. Table D-7. PSD Class I and Class II Increments

PSD Class I PSD Class II Pollutant Averaging Time Increment Increment (µg/m3) (µg/m3) 1 NO2 Annual 2.5 25 24-hour 2 8 30 PM 10 Annual 1 4 17 24-hour 2 2 9 PM 2.5 Annual 1 1 4 3-hour 2 25 512 2 SO2 24-hour 5 91 Annual 1 2 20 Source: 40 CFR 52.21(c). 1 Annual arithmetic mean. 2 No more than one exceedance per year.

Comparisons of project impacts to the PSD Class I and II increments are for informational purposes only and are intended to evaluate a threshold of concern. They do not represent a regulatory PSD Increment Consumption Analysis, which would be completed as necessary during the New Source Review permitting process by the State of Colorado.

1.3.4 Air Quality Related Values In addition to the PSD increments, Class I areas are protected by the Federal Land Managers through management of AQRVs, such as visibility, atmospheric deposition, aquatic ecosystems, flora, fauna, etc. Evaluation of potential impacts to AQRVs would be performed during the New Source Review permitting process under the direction of the CDPHE-APCD in consultation with the Federal Land Managers. AQRVs have been identified as a concern at several Federal Class I and sensitive Class II areas in the region. The project area is within 200 km of ten Class I areas and four sensitive Class II areas as shown on Map D-1. Class I areas within 200 km of the project area include the Eagles Nest, Flat Tops, La Garita, Maroon Bells – Snowmass, Mount Zirkel, Weminuche and West Elk wilderness areas, and Arches, Black Canyon of the Gunnison, and Rocky Mountain national parks. Federal Class II areas within 200 km of the project area that are considered sensitive areas include the Raggeds and Uncompahgre wilderness areas, Dinosaur National Monument, and Colorado National Monument. Dinosaur National Monument is regulated as a Class I area for SO2 by the CDPHE. A discussion of the applicable AQRV analysis thresholds is provided below. Visibility Change in atmospheric light extinction relative to background conditions is used to measure regional haze. Analysis thresholds for atmospheric light extinction are set forth in the Federal Land Managers’ Air Quality Related Values Work Group (FLAG) Report (FLAG 2010), with the results reported in percent change in light extinction and change in deciviews (dv). A 5 percent change in light extinction (approximately equal to a 0.5 change in dv) is the threshold recommended in FLAG (2010) and is considered to contribute to regional haze visibility impairment. A 10 percent change in light extinction (approximately equal to 1.0 dv) is considered to represent a noticeable change in visibility when compared to background conditions. Atmospheric Deposition and Lake Chemistry The effects of atmospheric deposition of nitrogen and sulfur compounds on terrestrial and aquatic ecosystems are well documented and have been shown to cause leaching of nutrients from soils, acidification of surface waters, injury to high elevation vegetation, and changes in nutrient cycling and species composition. FLAG (2010) recommends that applicable sources assess impacts of nitrogen and sulfur deposition at Class I areas. This guidance recognizes the importance of establishing critical deposition loading values (“critical loads”) for each specific Class I area as these critical loads are completely dependent on local atmospheric, aquatic, and terrestrial conditions and chemistry. Critical load thresholds are essentially a level of atmospheric pollutant deposition below which negative ecosystem effects are not likely to occur. FLAG (2010) does not include any critical load levels for specific Class I areas and refers to site-specific critical load information on Federal Land Manager websites for each area of concern. This guidance does, however, recommend the use of deposition analysis thresholds (DATs) developed by the National Park Service (NPS) and the U.S. Fish and Wildlife Service (USFWS). The DATs represent screening level values for nitrogen and sulfur deposition from project-specific emission sources below which estimated impacts are considered negligible. The DAT established for both nitrogen and sulfur in western Class I areas is 0.005 kilogram per hectare per year (kg/ha-yr).

Map D-1. Air Quality PSD Class I and Sensitive Class II Areas in Relation to the Project Area

In addition to the project-specific analysis, results from cumulative emission sources are compared to critical load thresholds established for the Rocky Mountain region to assess total deposition impacts. The NPS has provided recent information on nitrogen critical load values applicable for Wyoming and Colorado Class I and sensitive Class II areas (NPS 2014). For Colorado Class I and sensitive Class II areas (with the exception of Dinosaur National Monument) a critical load value of 2.3 kg/ha-yr is applicable for total nitrogen deposition, based on research conducted by Baron (2006) that estimated 1.5 kg/ha-yr as a critical loading value for wet nitrogen deposition for high-elevation lakes in Rocky Mountain National Park, Colorado. For Dinosaur National Monument, which is an arid region, a nitrogen deposition critical load value is based on research conducted by Pardo et al. (2011) which concluded that the cumulative critical load necessary to protect shrublands and lichen communities in Dinosaur National Monument is 3 kg N/ha-yr. For sulfur deposition, current critical load values have not been established for the Rocky Mountain region. For this project the critical load threshold published by Fox et al. (1989) for total sulfur of 5 kg/ha-yr, for the Bob Marshall Wilderness Area in Montana and Bridger Wilderness Area in Wyoming, is used as the critical load threshold for cumulative source impacts at Class I areas. This value is likely an overestimate of a current representative critical load value for the region. Analyses to assess the change in water chemistry associated with atmospheric deposition are performed following the procedures developed by the Forest Service Rocky Mountain Region (Forest Service 2000). The analysis assesses the change in the acid neutralizing capacity (ANC) of nine sensitive lakes in the region that have been identified as acid sensitive lakes (shown in Table D-10, below). Predicted changes in ANC are compared with the applicable threshold of concern for each identified lake: 10 percent change in ANC for lakes with background ANC values greater than 25 microequivalents per liter (μeq/l), and less than a 1 μeq/l change in ANC for lakes with background ANC values equal to or less than 25 μeq/l.

1.3.5 New Source Performance Standards Under Section 111 of the CAA, the EPA has promulgated technology-based emissions standards that apply to specific categories of stationary sources. These standards are referred to as NSPS (40 CFR Part 60). The NSPS potentially applicable to the project include the following subparts of 40 CFR Part 60:  Subpart A – General Provisions  Subpart Kb – Standards of Performance for Volatile Organic Liquid Storage Vessels . Subpart JJJJ – Standards of Performance for Stationary Spark-Ignition Internal Combustion Engines  Subpart OOOO – Standards for Crude Oil and Natural Gas Production  Subpart OOOOa – Standards for Crude Oil and Natural Gas Facilities Subpart A – General Provisions. Provisions of Subpart A apply to the owner or operator of any stationary source that contains an affected facility. The provisions apply to facilities that commenced construction or modification after the date of publication of any proposed standard. Provisions of Subpart A apply to proposed project sources that are affected by the NSPS. Subpart Kb – Volatile Organic Liquid Storage Vessels. Subpart Kb applies to storage vessels with a capacity greater than or equal to 75 cubic meters (m3) that are used to store volatile organic liquids for which construction, reconstruction, or modification is commenced after July 23, 1984. This subpart is applicable to storage tanks for natural gas liquids. Subpart JJJJ – Stationary Spark Ignition Internal Combustion Engines. Subpart JJJJ establishes emission standards and compliance schedules for the control of emissions from spark ignition (SI) internal combustion engines (ICEs). The rule requires new engines of various horsepower classes to meet increasingly stringent nitrogen oxides (NOx) and volatile organic compound (VOC) emission standards

over the phase-in period of the regulation. Owners and operators of stationary SI ICEs that commenced construction, modification, or reconstruction after June 12, 2006, are subject to this rule; standards will depend on the engine horsepower and manufacture date. This regulation applies to central compressor engines, wellhead and lateral compressor engines, and artificial lift engines as well as any other miscellaneous engines that are stationary, spark-ignited natural gas-powered engines. Therefore, provisions of Subpart JJJJ apply to proposed SI ICE sources in the project area. Subpart OOOO – Crude Oil and Natural Gas Production. Effective October 15, 2012, with related amendments through July 31, 2015, the NSPS Subpart OOOO regulates VOC emissions from common sources in oil and gas upstream and midstream facilities that include well sites and natural gas processing plants. It also regulates sulfur dioxide emissions from sweetening units at onshore natural gas processing plants. The emission sources affected by Subpart OOOO include well completions, pneumatic controllers, equipment leaks from natural gas processing plants, sweetening units at natural gas processing plants, reciprocating compressors, centrifugal compressors and storage vessels at facilities that are constructed, modified or reconstructed after August 23, 2011. Well completions subject to Subpart OOOO are limited to hydraulic fracturing or re-fracturing completion operations at natural gas wells. Subpart OOOOa – Crude Oil and Natural Gas Facilities. Effective August 2, 2016, NSPS Subpart OOOOa (EPA 2016) regulates VOC and methane emissions from constructed, modified, or reconstructed oil and gas upstream and midstream facilities. Newly regulated emission sources includes 1) fugitive emissions from well sites and compressor stations, 2) hydraulically fractured or re-fractured oil well completions, 3) pneumatic pumps, and 4) compressors and pneumatic controllers at natural gas transmission compressor stations and gas storage facilities. In April 2017, the EPA announced it is reviewing this rule and, if appropriate, will initiate reconsideration proceedings to suspend, revise, or rescind this rule (EPA 2017a).

1.3.6 National Emission Standards for Hazardous Air Pollutants Under Section 112 of the CAA, the EPA has promulgated emissions standards for HAPs that apply to specific source categories. These standards are referred to as NESHAPs and are codified in 40 CFR Part 63. Applicable to this project is 40 CFR Part 63 Subpart HH, National Emission Standards for Hazardous Air Pollutants from Oil and Natural Gas Production Facilities. Subpart HH sets standards for benzene, ethyl benzene, toluene, and xylene (BTEX) at gas well facilities and natural gas processing plants. Sources regulated include existing and new, small and large glycol dehydrators at major and area sources, certain storage vessels at major sources, and compressors and ancillary equipment in service at major sources.

1.3.7 Non-Road Engine Tier Standards

The EPA sets emissions standards for non-road diesel engines for hydrocarbons, NOx, CO, and particulate matter. The emissions standards are implemented in tiers by year, with different standards and start years for various engine power ratings. The new standards do not apply to existing non-road equipment. Only equipment built after the start date for an engine category (1999-2006, depending on the category) is affected by the rule. Over the life of the project, the fleet of non-road equipment will turn over and higher-emitting engines will be replaced with lower-emitting engines.

1.3.8 Colorado Oil and Gas Permitting Guidance CDPHE Air Quality Control Commission regulations that apply to the project include:  Regulation 3 emissions reporting requirements  Regulation 6, which fully adopts the EPA’s Standards of Performance for Crude Oil and Natural Gas Production, Transmission, and Distribution found in 40 CFR, Part 60, Subpart OOOO (“NSPS OOOO”)

 Regulation 7, which includes extensive VOC reductions and regulates methane emissions from the oil and gas industry 1.4 GREENHOUSE GASES AND CLIMATE CHANGE Climate change is a statistically-significant and long-term change in climate patterns. The terms climate change and “global warming” are often used interchangeably, although they are not the same thing. Climate change is any deviation from the average climate, whether warming or cooling, and can result from both natural and human (anthropogenic) sources. Natural contributors to climate change include fluctuations in solar radiation, volcanic eruptions, and plate tectonics. Global warming refers to the apparent warming of climate observed since the early 20th century, which many scientists primarily attribute to human activities, such as fossil fuel combustion, industrial processes, and land use changes. The natural greenhouse effect is critical to the discussion of climate change. The greenhouse effect refers to the process by which greenhouse gases (GHGs) in the atmosphere absorb heat energy radiated by Earth’s surface and re-radiate some of that heat back toward Earth, causing temperatures in the lower atmosphere and on the surface of Earth to be higher than they would be without atmospheric GHGs. These GHGs trap heat that would otherwise be radiated into space, causing Earth’s atmosphere to warm and making temperatures suitable for life on Earth. Without the natural greenhouse effect, the average surface temperature of Earth would be about 0˚F. Higher concentrations of GHGs amplify the heat- trapping effect resulting in higher surface temperatures. Water vapor is the most abundant GHG, followed by carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and several trace gases. Water vapor, which occurs naturally in the atmosphere, is often excluded from the discussion of GHGs and climate change because its atmospheric concentration is largely dependent upon temperature rather than being emitted by specific sources. Certain GHGs, such as CO2 and CH4, occur naturally in the atmosphere and are also emitted into the atmosphere by human activities. Atmospheric concentrations of naturally-emitted GHGs have varied for millennia and Earth’s climate has fluctuated accordingly. However, since the beginning of the industrial revolution around 1750, human activities have significantly increased GHG concentrations and introduced man-made compounds that act as GHGs in the atmosphere. The atmospheric concentrations of CO2, CH4, and N2O have increased to levels unprecedented in at least the last 800,000 years. From pre-industrial times until today, the global average concentrations of CO2, CH4, and N2O in the atmosphere have increased by around 40 percent, 150 percent, and 20 percent, respectively (Intergovernmental Panel on Climate Change [IPCC] 2013).

Human activities emit billions of tons of CO2 every year. Carbon dioxide is primarily emitted from fossil fuel combustion, but has a variety of other industrial sources. Methane is emitted from oil and natural gas systems, landfills, mining, agricultural activities, and waste and other industrial processes. Nitrous oxide is emitted from anthropogenic activities in the agricultural, energy-related, waste, and industrial sectors. The manufacture of refrigerants and semiconductors, electrical transmission, and metal production emit a variety of trace GHGs, including hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. These trace gases have no natural sources and come entirely from human activities. Carbon dioxide, CH4, N2O, and the trace gases are considered well-mixed and long-lived GHGs. Several gases have no direct effect on climate change, but indirectly affect the absorption of radiation by impacting the formation or destruction of GHGs. These gases include CO, NOX, and non-methane VOCs. Fossil fuel combustion and industrial processes account for the majority of emissions of these indirect GHGs. Unlike other GHGs, which have atmospheric lifetimes on the order of decades, these gases are short-lived in the atmosphere. Atmospheric aerosols, or particulate matter (PM), also contribute to climate change. Aerosols directly affect climate by scattering and absorbing radiation (aerosol-radiation interactions) and indirectly affect climate by altering cloud properties (aerosol-cloud interactions). PM10 typically originates from natural sources and settles out of the atmosphere in hours or days. PM2.5 often originates from human activities

such as fossil fuel combustion. These so-called “fine” particles can exist in the atmosphere for several weeks and have local, short-term impacts on climate. Aerosols can also act as cloud condensation nuclei, the particles upon which cloud droplets form. Light-colored particles, such as sulfate aerosols, reflect and scatter incoming solar radiation, having a mild cooling effect, while dark-colored particles (often referred to as “soot” or “black carbon”) absorb radiation and have a warming effect. There is also the potential for black carbon to deposit on snow and ice, altering the surface albedo (or reflectivity), and enhancing melting. There is high confidence that aerosol effects are partially offsetting the warming effects of GHGs, but the magnitude of their effects contributes the largest uncertainly to the understanding of climate change (IPCC 2013). Current understanding of the climate system comes from the cumulative results of observations, experimental research, theoretical studies, and model simulations. The IPCC Fifth Assessment Report (AR5) (IPCC 2013) uses terms to indicate the assessed likelihood of an outcome ranging from exceptionally unlikely (0 to 1 percent) to virtually certain (99 to 100 percent probability) and level of confidence ranging from very low to very high. The findings presented in the AR5 indicate that warming of the climate system is unequivocal and many of the observed changes are unprecedented over decades to millennia. It is certain that Global Mean Surface Temperature has increased since the late 19th century and virtually certain (99 to 100 percent probability) that maximum and minimum temperatures over land have increased on a global scale since 1950. The globally averaged combined land and ocean surface temperature data show a warming of 1.5°F. Human influence has been detected in warming of the atmosphere and the ocean, in changes in the global water cycle, in reductions in snow and ice, in global mean sea-level rise, and in changes in some climate extremes. It is extremely likely (95 to 100 percent probability) that human influence has been the dominant cause of the observed warming since the mid- 20th century (IPCC 2013). Findings from the AR5 and reported by other organizations, such as the National Aeronautics and Space Administration (NASA) Goddard Institute for Space Studies (National Oceanic and Atmospheric Administration [NOAA] 2013), also indicate that changes in the climate system are not uniform and regional differences are apparent. The IPCC released a special report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emissions pathways (IPCC 2018). The report summarizes their conclusions from a number of key findings, several of which are excerpted here: Human activities are estimated to have caused approximately 1.0°C of global warming above pre- industrial levels, with a likely range of 0.8°C to 1.2°C. Global warming is likely to reach 1.5°C between 2030 and 2052 if it continues to increase at the current rate. Warming from anthropogenic emissions from the pre-industrial period to the present will persist for centuries to millennia and will continue to cause further long-term changes in the climate system, such as sea level rise, with associated impacts (high confidence), but these emissions alone are unlikely to cause global warming of 1.5°C (medium confidence). Climate models project robust differences in regional climate characteristics between present-day and global warming of 1.5°C, and between 1.5°C and 2°C. These differences include increases in: mean temperature in most land and ocean regions (high confidence), hot extremes in most inhabited regions (high confidence), heavy precipitation in several regions (medium confidence), and the probability of drought and precipitation deficits in some regions (medium confidence). By 2100, global mean sea level rise is projected to be around 0.1 meters lower with global warming of 1.5°C compared to 2°C (medium confidence). Sea level will continue to rise well beyond 2100 (high confidence), and the magnitude and rate of this rise depend on future emission pathways. A slower rate of sea level rise enables greater opportunities for adaptation in the human and ecological systems of small islands, low-lying coastal areas, and deltas (medium confidence).

Limiting global warming to 1.5°C compared to 2ºC is projected to reduce increases in ocean temperature as well as associated increases in ocean acidity and decreases in ocean oxygen levels (high confidence). Consequently, limiting global warming to 1.5°C is projected to reduce risks to marine biodiversity, fisheries, and ecosystems, and their functions and services to humans, as illustrated by recent changes to Arctic sea ice and warm-water coral reef ecosystems (high confidence). National Assessment of Climate Change. The U.S. Global Change Research Program released the fourth U.S. National Climate Assessment in 2018. The Assessment summarizes the current state of knowledge on climate change and its impacts throughout the U.S. It was written by climate scientists and draws from a large body of peer-reviewed scientific research, technical reports, and other publicly available sources. The Assessment documents climate change impacts that are currently occurring and those that are anticipated to occur throughout this century. It also provides region-specific impact assessments for key sectors, such as energy, water, and human health. The Assessment summarizes their conclusions from a number of Key Messages (National Climate Assessment [NCA] 2018a), several of which are excerpted here: Global climate is changing rapidly compared to the pace of natural variations in climate that have occurred throughout Earth’s history. Global average temperature has increased by about 1.8°F from 1901 to 2016, and observational evidence does not support any credible natural explanations for this amount of warming; instead, the evidence consistently points to human activities, especially emissions of greenhouse or heat-trapping gases, as the dominant cause. Earth’s climate will continue to change over this century and beyond. Past mid-century, how much the climate changes will depend primarily on global emissions of greenhouse gases and on the response of Earth’s climate system to human-induced warming. With significant reductions in emissions, global temperature increase could be limited to 3.6°F (2°C) or less compared to preindustrial temperatures. Without significant reductions, annual average global temperatures could increase by 9°F (5°C) or more by the end of this century compared to preindustrial temperatures. The world’s oceans have absorbed 93% of the excess heat from human-induced warming since the mid-20th century and are currently absorbing more than a quarter of the carbon dioxide emitted to the atmosphere annually from human activities, making the oceans warmer and more acidic. Increasing sea surface temperatures, rising sea levels, and changing patterns of precipitation, winds, nutrients, and ocean circulation are contributing to overall declining oxygen concentrations in many locations. Global average sea level has risen by about 7–8 inches (about 16–21 cm) since 1900, with almost half this rise occurring since 1993 as oceans have warmed and land-based ice has melted. Relative to the year 2000, sea level is very likely to rise 1 to 4 feet (0.3 to 1.3 m) by the end of the century. Emerging science regarding Antarctic ice sheet stability suggests that, for higher scenarios, a rise exceeding 8 feet (2.4 m) by 2100 is physically possible, although the probability of such an extreme outcome cannot currently be assessed. Annual average temperature over the contiguous United States has increased by 1.2ºF (0.7°C) over the last few decades and by 1.8°F (1°C) relative to the beginning of the last century. Additional increases in annual average temperature of about 2.5°F (1.4°C) are expected over the next few decades regardless of future emissions, and increases ranging from 3°F to 12°F (1.6°–6.6°C) are expected by the end of century, depending on whether the world follows a higher or lower future scenario, with proportionally greater changes in high temperature extremes.

Annual precipitation since the beginning of the last century has increased across most of the northern and eastern United States and decreased across much of the southern and western United States. Over the coming century, significant increases are projected in winter and spring over the Northern Great Plains, the Upper Midwest, and the Northeast. Observed increases in the frequency and intensity of heavy precipitation events in most parts of the United States are projected to continue. Surface soil moisture over most of the United States is likely to decrease, accompanied by large declines in snowpack in the western United States and shifts to more winter precipitation falling as rain rather than snow. In the Arctic, annual average temperatures have increased more than twice as fast as the global average, accompanied by thawing permafrost and loss of sea ice and glacier mass. Arctic-wide glacial and sea ice loss is expected to continue; by mid-century, it is very likely that the Arctic will be nearly free of sea ice in late summer. Permafrost is expected to continue to thaw over the coming century as well, and the carbon dioxide and methane released from thawing permafrost has the potential to amplify human-induced warming, possibly significantly. Human-induced change is affecting atmospheric dynamics and contributing to the poleward expansion of the tropics and the northward shift in Northern Hemisphere winter storm tracks since 1950. Increases in greenhouse gases and decreases in air pollution have contributed to increases in Atlantic hurricane activity since 1970. In the future, Atlantic and eastern North Pacific hurricane rainfall and intensity are projected to increase, as are the frequency and severity of landfalling “atmospheric rivers” on the West Coast. Regional changes in sea level rise and coastal flooding are not evenly distributed across the United States; ocean circulation changes, sinking land, and Antarctic ice melt will result in greater-than- average sea level rise for the Northeast and western Gulf of Mexico under lower scenarios and most of the U.S. coastline other than Alaska under higher scenarios. Since the 1960s, sea level rise has already increased the frequency of high tide flooding by a factor of 5 to 10 for several U.S. coastal communities. The frequency, depth, and extent of tidal flooding are expected to continue to increase in the future, as is the more severe flooding associated with coastal storms, such as hurricanes and nor’easters. The climate change resulting from human-caused emissions of carbon dioxide will persist for decades to millennia. Self-reinforcing cycles within the climate system have the potential to accelerate human-induced change and even shift Earth’s climate system into new states that are very different from those experienced in the recent past. Future changes outside the range projected by climate models cannot be ruled out, and due to their systematic tendency to underestimate temperature change during past warm periods, models may be more likely to underestimate than to overestimate long-term future change. The Assessment provided analysis of projected climate change by region, and the project is part of the Southwest region. The Key Messages for this region (NCA 2018b) are as follows: Water for people and nature in the Southwest has declined during droughts, due in part to human- caused climate change. Intensifying droughts and occasional large floods, combined with critical water demands from a growing population, deteriorating infrastructure, and groundwater depletion, suggest the need for flexible water management techniques that address changing risks over time, balancing declining supplies with greater demands. The integrity of Southwest forests and other ecosystems and their ability to provide natural habitat, clean water, and economic livelihoods have declined as a result of recent droughts and wildfire due in part to human-caused climate change. Greenhouse gas emissions reductions, fire management, and other actions can help reduce future vulnerabilities of ecosystems and human well-being.

Traditional foods, natural resource-based livelihoods, cultural resources, and spiritual well-being of Indigenous peoples in the Southwest are increasingly affected by drought, wildfire, and changing ocean conditions. Because future changes would further disrupt the ecosystems on which Indigenous peoples depend, tribes are implementing adaptation measures and emissions reduction actions. The ability of hydropower and fossil fuel electricity generation to meet growing energy use in the Southwest is decreasing as a result of drought and rising temperatures. Many renewable energy sources offer increased electricity reliability, lower water intensity of energy generation, reduced greenhouse gas emissions, and new economic opportunities. Food production in the Southwest is vulnerable to water shortages. Increased drought, heat waves, and reduction of winter chill hours can harm crops and livestock; exacerbate competition for water among agriculture, energy generation, and municipal uses; and increase future food insecurity. Heat-associated deaths and illnesses, vulnerabilities to chronic disease, and other health risks to people in the Southwest result from increases in extreme heat, poor air quality, and conditions that foster pathogen growth and spread. Improving public health systems, community infrastructure, and personal health can reduce serious health risks under future climate change. Temperatures increased across almost all of the Southwest region from 1901 to 2016, with the greatest increases in southern California and western Colorado. The cumulative forest area burned by wildfires has greatly increased between 1984 and 2015, with analyses estimating that the area burned by wildfire across the western United States over that period was twice what would have burned had climate change not occurred. All climate model projections indicate future warming in Colorado (Bureau of Land Management [BLM] 2015). The Statewide average annual temperatures are projected to warm by +2.5 ºF to +5 ºF by 2050 relative to a 1971 to 2000 baseline under Representative Concentration Pathway (RCP) 4.5. Summer temperatures are projected to warm slightly more than winter temperatures, where the maximums would be similar to the hottest summers that have occurred in the past 100 years. Precipitation projections are less clear. Nearly all of the models predict an increase in winter precipitation by 2050, although most projections of snowpack (April 1 snow-water equivalent measurements) show declines by mid-century due to projected warming. Late-summer flows are projected to decrease as the peak shifts earlier in the season, although the changes in the timing of runoff are more certain than changes in the amount of runoff. In general, the majority of published research indicates a tendency towards future decreases in annual streamflow for all of Colorado’s river basins. Increased warming, drought, and insect outbreaks, all caused by or linked to climate change, will continue to increase wildfire risks and impacts to people and ecosystems. Project Greenhouse Gases and Climate Change. Greenhouse Gases projected to be emitted by project sources are carbon dioxide, methane, and nitrous oxide. In 2007, the U.S. Supreme Court ruled in Massachusetts v. EPA that the EPA has the authority to regulate GHGs such as CH4 and CO2 as air pollutants under the CAA. At present, there are no ambient air quality standards for GHGs. As mentioned above, the EPA NSPS for oil and gas emission sources (EPA 2016) will limit methane emissions and these methane emission limits would apply to the sources developed under the project. However, this rule is presently under review and the EPA may revise or rescind this rule (EPA 2017a). EPA’s Greenhouse Gas Reporting Program includes reporting requirements. These reporting requirements, finalized in 2010 under 40 CFR Part 98, requires Operators to develop and report annual CH4 and CO2 emissions from equipment leaks and venting, and emissions of CO2, CH4, and N2O from flaring, onshore production stationary and portable combustion emissions, and combustion emissions from stationary equipment.

Renewable and nonrenewable resource management actions have the potential to impact climate change due to GHG emissions and other anthropogenic effects. However, the assessment of GHG emissions and climate change is extremely complex because of the inherent interrelationships among its sources, causation, mechanisms of action, and impacts. Emitted GHGs become well-mixed throughout the atmosphere and contribute to the global atmospheric burden of GHGs. Given the global and complex nature of climate change, it is not possible to attribute a particular climate impact in any given region to GHG emissions from a particular source. The uncertainty in applying results from Global Climate Models to the regional or local scale (a process known as downscaling) limits the ability to quantify potential future localized physical impacts from GHGs emissions at this scale. When further information on the impacts of local emissions to climate change is known, such information would be incorporated into BLM planning and NEPA documents as appropriate. 1.5 MONITORED AIR POLLUTANT CONCENTRATIONS Monitoring of air pollutant concentrations has been conducted in the region. These monitoring sites are part of several monitoring networks overseen by State and Federal agencies, including: CDPHE, Clean Air Status and Trends Network (CASTNET), Interagency Monitoring of Protected Visual Environments (IMPROVE), and National Atmospheric Deposition Program’s (NADP’s) National Trends Network (NTN).

Air pollutants monitored in the region include the criteria pollutants: CO, NO2, O3, PM10, PM2.5, and SO2. Background concentrations of these pollutants define ambient air concentrations in the region and establish existing compliance with ambient air quality standards. The most representative monitored regional background concentrations available for criteria pollutants (CDPHE 2016) are shown in Table D-8. Table D-8. Background Ambient Air Quality Concentrations

Measured Background Pollutant Averaging Period Concentration (µg/m3) 1-hour 1,145 CO 1 8-hour 1,145 1-hour 21 1 NO2 Annual 1.9 24-hour 27 2 PM10 Annual 16 24-hour 14 1 PM2.5 Annual 3 Ozone 3 8-hour 126 1-hour 2.6 3-hour 2.6 1 SO2 24-hour 2.6 Annual 2.6 1 Williams Willow Creek, 2012. 2 Greasewood, 2009-2010. 3 Palisade, 2013-2015. Source: CDPHE 2016

1.6 MONITORED VISIBILITY Visibility conditions can be measured as standard visual range (SVR), defined as the farthest distance at which an observer can just see a black object viewed against the horizon sky; the larger the SVR, the cleaner the air. Continuous visibility-related optical background data have been collected in the Class I areas Flat Tops Wilderness, White River National Forest (Maroon Bells-Snowmass Wilderness), and Weminuche Wilderness, as part of the IMPROVE program. The average SVR at each of the three sites is historically greater than 150 km and in the most recent reported years, the average SVR has increased to greater than 200 km (IMPROVE 2017a). 1.7 MONITORED ATMOSPHERIC DEPOSITION Atmospheric deposition refers to the processes by which air pollutants are removed from the atmosphere and deposited on terrestrial and aquatic ecosystems, and it is reported as the mass of material deposited on an area per year in kg/ha-yr. Air pollutants are deposited by wet deposition (precipitation) and dry deposition (gravitational settling of pollutants). The chemical components of wet deposition include sulfate (SO4), nitrate (NO3), and ammonium (NH4); the chemical components of dry deposition include SO2, SO4, NO3, ammonia (NH3), NH4, and nitric acid (HNO3). The NADP’s NTN station monitors wet atmospheric deposition and the CASTNET station monitors dry atmospheric deposition at the Gothic site, located southeast of the project area near Crested Butte. The total annual deposition (wet and dry) reported as nitrogen (N) and sulfur (S) deposition for years 2006 through 2015 are shown in Table D-9. Table D-9. Gothic Site N and S Deposition Values (kg/ha-yr), 2006 to 2015

Year of Nitrogen Deposition Sulfur Deposition Monitoring Wet Dry Total Wet Dry Total 2006 1.41 1.33 2.74 0.69 0.28 0.97 2007 1.25 1.46 2.71 0.52 0.31 0.83 2008 1.09 1.36 2.46 0.63 0.32 0.95 2009 1.41 1.28 2.69 0.81 0.28 1.09 2010 1.45 1.20 2.65 0.73 0.25 0.97 2011 1.31 1.32 2.63 0.62 0.26 0.88 2012 1.28 1.22 2.50 0.48 0.22 0.70 2013 2.14 1.25 3.39 0.84 0.24 1.08 2014 1.75 1.15 2.90 0.64 0.21 0.85 2015 1.95 1.12 3.07 0.72 0.18 0.90 Source: EPA 2017b.

Table D-10 presents a list of nine lakes in the Flat Tops, Maroon Bells-Snowmass, Raggeds and West Elk wilderness areas that have been identified as acid sensitive lakes. Analyses for potential changes to lake acidity from atmospheric deposition are based on the ANC for the lake. The most recent lake chemistry background ANC data available from the IMPROVE network “Federal Land Manager Environmental Database” (IMPROVE 2017b) are shown in Table D-10. The ANC values shown are the 10th percentile lowest ANC values, which were calculated for each lake following procedures provided from the Forest Service. The years of monitoring data that were currently available, and the number of samples used in the calculation of the 10th percentile lowest ANC values, are provided. Of the nine lakes listed in Table

D-10, Upper Ned Wilson and Deep Creek lakes are considered by the Forest Service as extremely sensitive to atmospheric deposition because the background ANC values are less than 25 µeq/L. Table D-10. Background ANC Values for Acid Sensitive Lakes 1

10th Percentile Latitude Wilderness Longitude Lowest ANC Number of Monitoring Lake (Deg-Min- Area (Deg-Min-Sec) Value Samples Period Sec) (µeq/L)2 Flat Tops Ned Wilson Lake 39°57’41” 107°19’25” 39.0 191 1981-2007 Upper Ned Wilson Flat Tops 39°57’46” 107°19’25” 12.9 143 1983-2007 Lake Lower Packtrail Flat Tops 39°58’5” 107°19’24” 29.7 96 1987-2007 Pothole Upper Packtrail Flat Tops 39°57’56” 107°19’23” 48.7 96 1987-2007 Pothole Maroon Bells- Avalanche Lake 39°8’33” 107°5’53” 158.8 55 1991-2010 Snowmass Maroon Bells- Capitol Lake 39°9’42” 107°4’50” 154.4 57 1991-2010 Snowmass Maroon Bells- Moon Lake 39°9’49” 107°3’34” 53.0 54 1991-2010 Snowmass Raggeds Deep Creek Lake 39°0’30” 107°14’23” 20.6 24 1995-2009 West Elk South Golden Lake 38°46’39” 107°10’58” 111.4 25 1995-2008 1 Source: IMPROVE 2017b. 2 10th Percentile Lowest ANC Values reported.

2. ENVIRONMENTAL CONSEQUENCES

2.1 PROPOSED ACTION The Proposed Action includes expansion of one existing well pad (Trail Gulch Unit [TGU] Federal 1090 #30) on Federal surface/Federal minerals, constructing three new well pads, two (Sheep Park II Unit [SPU] Federal 1190 #20, and SPU Federal 1190 #29) on Federal surface/Federal minerals, and one new well pad (Deadman Gulch Unit [DGU] 1289 #20-23) on Fee surface/Fee minerals which would access Federal minerals. Each of these well pads would have up to eight wells. In addition an existing well pad (Iron Point Unit [IPU] 1291 #13-24) located on Fee surface/Fee minerals but accessing Federal minerals would accommodate up to three new wells. A total of 35 new wells are included the Proposed Action.

An air quality modeling analysis was performed to assess the impacts on ambient air quality and AQRVs from potential air emissions due to the Proposed Action. Both near-field and far-field air quality analyses were performed. Potential ambient air quality impacts were quantified and compared to applicable State and Federal ambient air quality standards, PSD increments and HAP thresholds. AQRV impacts (impacts on visibility, atmospheric deposition, and potential increases in acidification to acid-sensitive lakes) were determined and compared to applicable thresholds.

2.1.1 Near-Field Modeling A near-field assessment of impacts on ambient air quality was performed to evaluate maximum pollutant impacts within and near the project area resulting from development and operation. EPA's Guideline (EPA 2005) model, AERMOD (version 16216r), was used to assess these near-field impacts. The near- field modeling used five years of hourly surface meteorological data (2012-2016) collected at the Aspen-

Pitkin County airport along with concurrent twice daily upper air meteorological data collected at the Grand Junction airport. The near-field criteria pollutant assessment was performed to estimate maximum potential impacts of CO, NO2, SO2, PM10, and PM2.5 from well pad and road construction, well drilling/completion and production emissions sources. Near-field HAP (benzene, toluene, ethyl benzene, xylenes, n-hexane, and formaldehyde) emissions from production operations were evaluated for purposes of assessing impacts in the immediate vicinity of the project area for both short-term (acute) exposure and for calculation of long- term human health risk.

The near-field analysis of development activities included an assessment of PM10 and PM2.5 impacts from fugitive dust and vehicle tailpipe particulate emissions from construction of a new well pad (SPU Federal 1190 #20) and road segment. Criteria pollutant impacts were analyzed from concurrent completion and drilling operations at well pads SPU Federal 1190 #20 and SPU Federal #29. This modeling scenario included emissions from simultaneous completion and drilling operations at the two well pads and it included production operations at well pads TGU Federal 1090 #30, DGU 1289 #20-23 and IPU 1291 #13-24. This scenario conservatively assumed that the drilling and completion operations would occur continuously at the two well pad locations 24 hours per day over an entire year. The near-field analysis of production operations included an impact assessment for criteria pollutants and HAPs from 35 (total) new wells located at the five well pad locations within the project area. Modeling analyses for well production and drilling/completion operations utilized receptor grids that extended outward at least 1.5 km from the edge of any well pad. Discrete modeling receptors were placed at 25-meter (m) intervals along the edge of the well pads and then at 100-m intervals outward at least 1.5 km. For the development of the SPU Federal 1190 #20 well pad, the model receptors were placed at 25- m intervals along a boundary 100-m from the pad and at 100-m intervals extending outward approximately 1.5 km. Terrain elevations for each receptor were developed using the AERMAP (Version 11103) processor along with available digital elevation model data.

2.1.2 Far-Field Modeling A far-field assessment of ambient air impacts quantified potential air quality impacts to both ambient air concentrations and AQRVs from air pollutant emissions of NOX, SO2, PM10, and PM2.5 expected to result from the Proposed Action. Ambient air quality impacts of NO2, SO2, PM10, and PM2.5 and AQRVs were analyzed at far-field Federal Class I and sensitive Class II areas located within 100 km of the project area. The Class I areas located within 100 km of the project area include the Black Canyon of the Gunnison National Park, Flat Tops Wilderness, Maroon Bells-Snowmass Wilderness and West Elk Wilderness. Federal Class II areas within 100 km of the Project Area that are considered sensitive areas include the Raggeds Wilderness and Colorado National Monument. Nine lakes that are designated as acid sensitive and are located within the Flat Tops Wilderness Area (Ned Wilson Lake, Upper Ned Wilson Lake, Lower Packtrail Pothole, and Upper Packtrail Pothole), Maroon Bells-Snowmass Wilderness area (Avalanche Lake, Capitol Lake, and Moon Lake), Raggeds Wilderness Area (Deep Creek Lake) and West Elk Wilderness Area (South Golden Lake) were assessed for potential lake acidification from atmospheric deposition impacts. The far-field analyses used the EPA-approved version of the CALPUFF modeling system (Version 5.8) along with a windfield developed for year 2011 using the Mesoscale Model Interface Program (MMIF) Version 3.2 (ENVIRON 2015) and the 2011 Weather Research and Forecasting (WRF) meteorological model output that was produced as part of the Three-State Air Quality Study (3SAQS) (University of North Carolina Institute for the Environment and ENVIRON 2015). The far-field assessments considered both short-term and long-term maximum field-wide emissions scenarios with concurrent completion and drilling operations at well pads SPU Federal 1190 #20 and SPU Federal #29 and production operations at well pads TGU Federal 1090 #30, DGU 1289 #20-23 and IPU

1291 #13-24. This scenario conservatively assumed that the drilling and completion operations would occur continuously over the year at well pad SPU Federal 1190 #20, and at SPU Federal 1190 #29 during the months May through November.

2.1.3 Impact Significance Criteria Air quality impacts from pollutant emissions are limited by regulations, standards and implementation plans established under the Federal CAA, as administered by the CDPHE-APCD under authorization of the EPA. Under the Federal Land Policy and Management Act (FLPMA) and the CAA, the BLM requires activities that it authorizes to conform to all applicable local, State, Tribal, or Federal air quality laws, statutes, regulations, standards, or implementation plans. As such, significant impacts to air quality from project-related activities may be expected if analysis indicates that: • NAAQS or CAAQS would be exceeded. • AQRVs would be impacted beyond acceptable thresholds of concern. All NEPA analysis comparisons to the PSD Class I and II increments are intended to evaluate a threshold of concern, and do not represent a regulatory PSD Increment Consumption Analysis. The determination of PSD increment consumption is an air quality regulatory agency responsibility. Such an analysis would be conducted to determine minor source increment consumption or, for major sources, as part of the New Source Review process. The New Source Review process would also include an evaluation of potential impacts to AQRVs such as visibility, aquatic ecosystems, flora, fauna, etc. performed under the direction of the appropriate Federal Land Managers.

2.1.4 Emission Inventory Development Air pollutant emissions would occur as part of development and well production. Sources of emissions during development include vehicle traffic, well pad and road construction, pipeline construction, and well drilling and completion. The primary pollutants emitted during construction would be PM10, PM2.5, NOx, CO, SO2, VOCs, and HAPs including benzene, toluene, ethyl benzene, xylenes, n-hexane, and formaldehyde. These activities would temporarily elevate pollutant levels, but impacts would be localized and would occur only for a short-term duration. Fugitive dust emissions (PM10 and PM2.5) would result from work crews commuting to and from the work site and from the transportation and operation of equipment during development. Wind-blown fugitive dust emissions would also occur from open and disturbed land during development. Emissions from development were quantified using accepted methodologies, including manufacturer’s emission factors, EPA emission factors and standards, and engineering estimates. Drill rig and completion engines would be Tier 2 emissions compliant. Maximum annual field-wide criteria pollutant and HAPs emissions resulting from well pad and pipeline construction and from drilling and completion activities are shown in Table D-11. The development emissions also assume that a maximum of 12 wells would be drilled and completed in one year. The total HAPs emissions include benzene, toluene, ethyl benzene, xylenes, n-hexane, and formaldehyde emissions of 0.07, 0.03, 0.00003, 0.01, 0.003, and 0.07 tons per year (tpy), respectively. During field production operations, each of the one expanded and three new well pads would contain a total of 32 new producing wells (eight wells each), and the existing well pad would include three additional wells. Emissions during this phase would occur from vehicle traffic on roads during routine field operations and maintenance, separator and tank heaters, and workover rigs. There would also be fugitive emissions resulting from the well site equipment. Table D-11. Development Emissions

Activity Tons Per Year

PM10 PM2.5 NOx CO SO2 VOC HAPs Well Pad, Pipeline and 2.51 0.39 3.65 3.33 0.16 0.27 -- Road Construction Drill Rig Engines 1.75 1.75 52.57 30.37 0.18 3.50 0.05 Drilling and Rig Move 6.30 0.66 0.90 1.34 0.01 0.14 -- Traffic Completion Engines 0.67 0.67 16.22 9.52 0.01 1.77 0.13 Completion Traffic 15.41 1.86 6.38 4.96 0.03 0.60 -- Completion 0.05 0.05 0.42 2.28 -- 0.14 <0.01 Venting/Flaring Maximum Annual 26.69 5.38 80.14 51.80 0.39 6.42 0.18 Emissions

The primary pollutants emitted would be PM10, PM2.5, NOx, CO, SO2, VOCs, and HAPs. These emissions would impact air quality in the project area over the life of the project. Production equipment is subject to current and future CDPHE Best Available Control Technology (BACT) and Reasonably Achievable Control Technology (RACT) guidance and applicable portions of 40 CFR Part 63 Subparts OOOO and OOOOa, Standards of Performance for Crude Oil and Natural Gas Production. Maximum annual production emissions are summarized in Table D-12. The total HAPs emissions include benzene, toluene, ethyl benzene, xylenes, n-hexane, and formaldehyde emissions of 0.19, 0.11, 0.001, 0.01, 0.05, and 0.31 tpy, respectively. Table D-12. Annual Production Emissions

Tons Per Year Activity PM10 PM2.5 NOx CO SO2 VOC HAPs Workover Rig Engines <0.01 <0.01 0.03 0.02 <0.01 <0.01 <0.01 Production Traffic 4.03 0.42 0.44 0.64 <0.01 0.06 -- Separator and Tank Heaters 0.93 0.93 12.21 6.10 -- 3.86 0.54 Generators 0.80 0.80 17.74 13.40 0.02 1.45 0.01 Production Fugitives ------2.93 0.12 Total Production 5.76 2.15 30.42 20.16 0.02 8.30 0.67 Emissions

Greenhouse Gases

As part of the development of the project emission inventory, an inventory of CO2, CH4, and N2O emissions from field development and production activities was prepared. GHGs were not modeled in either the near-field or far-field impact analyses, but the GHG inventory is presented here for informational purposes and is compared to other U.S. GHG emission inventories in order to provide context for the project GHG emissions. As with the HAPs, ambient air quality standards do not exist for GHGs. GHG emissions from the Proposed Action are quantitatively assessed and then compared to various scales (County, State, and Federal) of GHG emissions from oil and gas production. This establishes a frame of reference for the reader to meaningfully analyze the potential impacts of the local- scale project at the global scale of climate change.

In the Proposed Action emission inventory, emissions of the greenhouse gases CO2, CH4, and N2O from new and existing sources were quantified in terms of CO2 equivalents (CO2e). GHGs have various capacities to trap heat in the atmosphere, which are known as GWPs. GWPs are related to different time intervals to fully account for the gases’ ability to absorb infrared radiation (heat) over their atmospheric lifetimes. The BLM uses the 100-year time interval since a majority of the climate change impacts derived from climate models are expressed toward the end of the century. Similarly, these models are often based on 100-year emissions projections (RCPs), such that providing a 1 to 1 comparison of the project emissions (NEPA) relative to the RCPs provides for a more meaningful and contextually relevant analysis. Carbon dioxide has a GWP of 1, so for the purposes of analysis, a GHG GWP is generally standardized to a CO2e, or the equivalent amount of CO2 mass the GHG would represent. Methane has a current estimated GWP between 28 (gas alone) and 36 (with climate feedbacks). N2O has a GWP of 298. Development and production emissions of GHGs (provided in units of metric tons per year) are shown in Table D-13. In addition, Table D-13 provides an estimate of the downstream GHG emissions (resulting from combustion of all project produced natural gas at facilities and activities that are not associated with the project and are not foreseeable future actions). The downstream GHGs were estimated assuming a maximum daily natural gas production rate of 20 million cubic feet per day (MMcfd) per well (255.5 billion cubic feet [bcf]) per year for 35 wells). Table D-13. GHG Emissions

Development Emissions Production Emissions Downstream Emissions Pollutant GWP (metric tpy) (metric tpy) (metric tpy)

CO2 1 11,235.2 22,084.9 12,937,012.6

CH4 36 4.6 87.7 244.0

N2O 298 0.08 0.05 24.4

CO2e (total) 11,428 25,257 12,953,068

2.1.5 Modeling Results Near-Field Modeling

Air pollutant dispersion modeling was performed to quantify maximum potential PM10, PM2.5, NOx, CO, SO2 and HAP impacts from development and production. AERMOD was used to model the maximum potential emissions of PM10, PM2.5, NOx, CO, and SO2 that could occur from the Proposed Action’s well pad/road construction, drilling/completion and production sources. Ozone impacts from this project are estimated as part of a regional air modeling study titled the Colorado Air Resource Management Modeling Study (CARMMS), discussed in Section 3.1. Table D-14 presents the maximum modeled air pollutant concentrations that could occur from development activities and Table D-15 presents the maximum impacts that could occur from well production. When maximum modeled concentrations from the modeled scenarios are added to representative background concentrations, it is demonstrated that the total ambient air concentrations are less than the applicable NAAQS and CAAQS. In addition, direct modeled concentrations resulting from production activities are below the applicable PSD Class II increments. Note that the emissions from well development activities would be temporary and would not consume PSD increment, and as a result are excluded from increment comparisons.

Table D-14. Maximum Modeled Pollutant Concentration Impacts (µg/m3) from Well Development Activities

Averaging Direct Total Pollutant Background NAAQS CAAQS Period Modeled Predicted 1-hour 2,424.7 1,145 3,569.7 40,000 40,000 CO 8-hour 1,098.8 1,145 2,243.8 10,000 10,000 1-hour 130.4 21.0 151.4 188 188 NO 2 Annual 49.7 1.9 51.6 100 100 1-hour 6.9 2.6 9.5 196 196 SO 2 3-hour 2.9 2.6 5.5 1,300 700

PM10 24-hour 85.8 27.0 112.8 150 150 24-hour 9.9 14.0 23.9 35 35 PM 2.5 Annual 3.2 3.0 6.2 12 12 Notes: Modeled highest second-high value shown for all short-term averaging periods, with the following exceptions: th NO2 1-hour value is calculated as the 5-year average of the 8 highest daily maximum 1-hour concentrations. SO2 1-hour value is the maximum 1-hour concentration. th PM2.5 24-hour value is the maximum 8 high concentration.

Table D-15. Maximum Modeled Pollutant Concentration Impacts (µg/m3) from Well Production Activities

Averaging Direct PSD Class II Total Pollutant Background NAAQS CAAQS Period Modeled Increment Predicted 1-hour 81.5 -- 1,145 1,226.5 40,000 40,000 CO 8-hour 34.3 -- 1,145 1,179.3 10,000 10,000 1-hour 85.4 -- 21.0 106.4 188 188 NO 2 Annual 7.9 25 1.9 9.8 100 100 1-hour 0.1 -- 2.6 2.7 196 196 3-hour 0.08 512 2.6 2.7 1,300 700 SO 2 24-hour 0.02 91 ------Annual 0.01 20 ------24-hour 4.3 30 27.0 31.3 150 150 PM 10 Annual 2.5 17 ------24-hour 4.3 9 14.0 18.3 35 35 PM 2.5 Annual 2.5 4 3.0 5.5 12 12 Notes: PSD demonstrations are informational only and do not constitute a regulatory increment consumption analysis. Modeled highest second-high value shown for all short-term averaging periods, with the following exceptions: th NO2 1-hour value is calculated as the 5-year average of the 8 highest daily maximum 1-hour concentrations. SO2 1-hour value is the maximum 1-hour concentration. th PM2.5 24-hour value is the maximum 8 high concentration.

Although the form of the 1-hour NAAQS for NO2 is a 3-year average (Table D-4), a 5-year averaging period is used herein following EPA guidance (EPA 2010) for 1-hour NO2 modeling when using NWS airport meteorological data in the analysis. For the 1-hour NO2 NAAQS/CAAQS compliance demonstrations for well development activities (Table D-14), the modeled NO2 impact presented above represents a 5-year average of the eighth-highest daily maximum 1-hour concentrations from combined well production and well drilling and completion operations. The 5-year average eighth highest daily

maximum 1-hour NO2 concentration was developed using the maximum eight-highest daily maximum 1- hour concentrations from two years of drilling and completion operations, and from three years of well production activities at the two well pads. Modeling was performed to estimate the maximum impacts that could occur from HAP emissions generated by production sources at the five well pads. Potential maximum acute (short-term, 1-hour) HAP concentrations are shown in Table D-16 compared with the acute RELs (EPA 2018a). RELs are defined as concentrations at or below which no adverse health effects are expected. No RELs are available for ethyl benzene and n-hexane; instead, the AEGLs for mild effects (AEGL-1) or moderate effects (AEGL-2) values are used (EPA 2018a). The AEGL-1 value is used for ethyl benzene and the AEGL-2 value is used for n-hexane. The AEGL values are 1-hour exposures that represent threshold levels for the general public. As shown in Table D-16, the maximum predicted acute HAP concentrations are below the threshold levels. Table D-16. Maximum Modeled 1-Hour HAP Concentration Impacts (µg/m3)

Air Toxics Direct Modeled REL Benzene 1.3 27 Toluene 0.7 37,000 Ethyl benzene 0.005 140,000 1 Xylene 0.07 22,000 n-Hexane 0.4 10,000,000 1 Formaldehyde 2.5 55 1 No REL available for these air toxics. Values shown are Acute Exposure Guideline Levels for mild effects (AELG-1) (ethyl benzene) and moderate effects (AEGL-2) (n-hexane).

Analyses were also performed for long-term (annual) HAP concentrations resulting from production sources. The potential annual HAP concentrations are shown in Table D-17 compared to non- carcinogenic RfCs (EPA 2018b). An RfC is defined by EPA as the daily inhalation concentration at which no long-term adverse health effects are expected. As shown in Table D-17, the maximum modeled annual HAP impacts are below the RfC levels. Table D-17. Maximum Modeled Annual HAP Concentration Impacts (µg/m3)

Air Toxic Direct Modeled RfC Benzene 0.09 30 Toluene 0.07 5,000 Ethyl Benzene 0.001 1,000 Xylene 0.01 100 n-Hexane 0.08 700 Formaldehyde 0.12 9.8

Long-term exposures to emissions of suspected carcinogens (benzene, ethyl benzene, and formaldehyde) were evaluated based on estimates of the increased latent cancer risk over a 70-year lifetime. This analysis presents the potential incremental risk from these pollutants, and does not represent a total risk analysis. The potential cancer risks were calculated using the maximum predicted annual concentrations

and EPA's chronic inhalation unit risk factors (URF) for carcinogenic constituents (EPA 2018a). Two estimates of cancer risk are presented: 1) a most likely exposure (MLE) scenario; and 2) a maximum exposed individual (MEI) scenario. The estimated cancer risks are adjusted to account for duration of exposure and time spent at home. The adjustment for the MLE scenario is assumed to be 9 years, which corresponds to the mean duration that a family remains at a residence (EPA 1993). This duration corresponds to an adjustment factor of 9/70 = 0.13. The duration of exposure for the MEI scenario is assumed to be 30 years (i.e., the life of the project), corresponding to an adjustment factor of 30/70 = 0.43. A second adjustment is made for time spent at home versus time spent elsewhere. For the MLE scenario, the at-home time fraction is 0.64 (EPA 1993) and it is assumed that during the rest of the day the individual would remain in an area where annual air toxics concentrations would be one-quarter as large as the maximum annual average concentration. Therefore, the final MLE adjustment factor is (0.13) x [(0.64 x 1.0) + (0.36 x 0.25)] = 0.095. The MEI scenario assumes that the individual is at home 100 percent of the time, for a final MEI adjustment factor of 0.43 (0.43 x 1.0). For each constituent, the cancer risk is computed by multiplying the maximum predicted annual concentration by the URF and by the overall exposure adjustment factor. The cancer risks for both constituents are then summed to provide an estimate of the total potential inhalation cancer risk. The modeled long-term risks from benzene, ethyl benzene and formaldehyde emissions resulting from field production emissions are shown in Table D-18. The estimated risks for both the MLE and MEI scenarios are below the acceptable one-in-one-million cancer risk level established by the EPA. Table D-18. Long-term Modeled MLE and MEI Cancer Risk Analyses

Direct Modeled Exposure URF Analysis Air Toxic Concentration Adjustment Cancer Risk 1/(µg/m3) (µg/m3) Factor Benzene 0.086 7.8 x 10-6 0.095 6.3 x 10-8 MLE Ethyl Benzene 0.001 2.5 x 10-6 0.095 2.4 x 10-10 Formaldehyde 0.120 1.3 x 10-5 0.095 1.5 x 10-7 Total Combined 2.1 x 10-7 Benzene 0.086 7.8 x 10-6 0.43 2.9 x 10-7 MEI Ethyl Benzene 0.001 2.5 x 10-6 0.43 1.1 x 10-9 Formaldehyde 0.120 1.3 x 10-5 0.43 6.7 x 10-7 Total Combined 9.6 x 10-7

Far-Field Modeling Far-field modeling at Class I and sensitive Class II areas within 100 km of the project area was performed using the CALPUFF model to quantify potential air quality impacts to both ambient air concentrations and AQRVs from emissions of NOx, SO2, PM10, and PM2.5 at levels expected to result from the Proposed Action. Class I and sensitive Class II areas analyzed include the Class I Black Canyon of the Gunnison National Park, Flat Tops Wilderness, Maroon Bells-Snowmass Wilderness, and West Elk Wilderness, and the Class II Raggeds Wilderness and Colorado National Monument. The far-field assessments considered both short-term and long-term maximum field-wide emissions scenarios with concurrent completion and drilling operations at well pads SPU Federal 1190 #20 and SPU Federal #29 and production operations at well pads TGU Federal 1090 #30, DGU 1289 #20-23 and IPU 1291 #13-24. This scenario conservatively assumed that the drilling and completion operations would

occur continuously over the year at well pad SPU Federal 1190 #20, and at SPU Federal 1190 #29 during the months May through November. The scenario is similar to the scenario modeled as part of the near- field analysis for the drilling and completion operations; however, it included field-wide completion and drilling traffic emissions (associated with all new roads within the project area) whereas the near-field scenario only included traffic emissions adjacent to the well pads. The modeled field-wide emissions included a maximum short-term (24-hour) emissions scenario used for estimated air quality and visibility impacts, and a long-term (annual) emissions scenario to estimate atmospheric deposition impacts. The modeled short-term emissions included: 43.5 tpy of PM10, 14.5 tpy of PM2.5, 321.0 tpy of NOX, and 0.6 tpy of SO2, and the modeled long-term emissions included 103.7 tpy NO2, and 0.4 tpy SO2. Both emissions scenarios are an overestimate of the maximum project emissions that are shown earlier given that the drilling and completion operations are assumed to occur continuously over the year. An additional modeling analysis was performed to estimate maximum atmospheric N deposition impacts from field-wide production NOX emissions (30.4 tpy). Class I and Sensitive Class II Area PSD Increment Comparison. The direct modeled concentrations of NO2, SO2, PM10, and PM2.5 at Class I and sensitive Class II areas are provided in Table D-19 for comparison to the corresponding PSD Class I and Class II increments. As shown in Table D-19, these values are well below the PSD increments.

Table D-19. Maximum Modeled Pollutant Concentrations at PSD Class I and Sensitive Class II Areas (µg/m3)

Averaging Direct PSD Location Pollutant Time Modeled Increment

NO2 Annual 0.001 2.5

3-hour 0.0005 25 SO2 24-hour 0.0001 5 Black Canyon of the Annual 0.00001 2 Gunnison National Park 24-hour 0.037 8 PM 10 Annual 0.002 4 24-hour 0.030 2 PM 2.5 Annual 0.001 1

NO2 Annual 0.0005 2.5

3-hour 0.0002 25 SO2 24-hour 0.00003 5 Flat Tops Wilderness Annual 0.000003 2 24-hour 0.022 8 PM 10 Annual 0.001 4 24-hour 0.018 2 PM 2.5 Annual 0.001 1

NO2 Annual 0.009 2.5

3-hour 0.0011 25 SO2 24-hour 0.0003 5 Maroon Bells/Snowmass Annual 0.00004 2 Wilderness 24-hour 0.137 8 PM 10 Annual 0.011 4 24-hour 0.114 2 PM 2.5 Annual 0.008 1

Averaging Direct PSD Location Pollutant Time Modeled Increment

NO2 Annual 0.013 2.5

3-hour 0.0016 25 SO2 24-hour 0.0005 West Elk Wilderness Annual 0.00004 2 24-hour 0.118 8 PM 10 Annual 0.009 4 24-hour 0.088 2 PM 2.5 Annual 0.007 1

NO2 Annual 0.024 25

3-hour 0.0031 512 SO2 24-hour 0.0006 91 Raggeds Wilderness Annual 0.0001 20 24-hour 0.214 30 PM 10 Annual 0.019 17 24-hour 0.155 9 PM 2.5 Annual 0.013 4

NO2 Annual 0.0003 25

3-hour 0.0001 512 SO2 24-hour 0.00003 91 Colorado National Annual 0.000001 20 Monument 24-hour 0.010 30 PM 10 Annual 0.0004 17 24-hour 0.009 9 PM 2.5 Annual 0.0003 4

AQRV Impacts – Visibility Impacts. Visibility impacts at Class I and sensitive Class II areas were calculated following FLAG 2010 (Table D-20). The visibility analysis indicated that the maximum predicted impacts occur at the Raggeds Wilderness Area. At the Raggeds Wilderness Area the maximum visibility impact is 0.65 dv and there are six days predicted above the 0.5 delta-deciview (Δdv) threshold. However when considering the maximum 98th percentile value for comparison to the threshold (as suggested in the FLAG 2010 report) the maximum predicted visibility impact at the Raggeds Wilderness Area is below the 0.5 Δdv threshold. Maximum visibility impacts at all other Class I and sensitive Class II areas are below the 0.5 Δdv threshold.

Table D-20. Maximum Visibility Impacts at Class I and Sensitive Class II Areas

Days Greater than Maximum Impact 98th Percentile Location 0.5 Δdv (Δdv) (Δdv) Black Canyon of the Gunnison Wilderness 0 0.12 0.06 Flat Tops Wilderness 0 0.08 0.03 Maroon Bells/Snowmass Wilderness 0 0.49 0.25 West Elk Wilderness 0 0.39 0.19 Raggeds Wilderness 6 0.65 0.49 Colorado National Monument 0 0.04 0.02

AQRV Impacts - Deposition Impacts. Potential direct atmospheric deposition impacts within Class I and sensitive Class II areas were also calculated for Proposed Action sources. At all Class I and sensitive Class II areas, the maximum direct total (wet and dry) N and S deposition are predicted to be well below the DAT established for both nitrogen and sulfur in western Class I areas (0.005 kg/ha-yr). The maximum predicted deposition impacts are predicted to occur at the Raggeds Wilderness Area and are 0.0026 kg/ha-yr (N) and 0.00003 kg/ha-yr (S). The maximum predicted N deposition impacts for the maximum emissions scenario (which includes well drilling and completion operations) and from the maximum production emissions scenario are provided in Table D-21. As is indicated in Table D-21 the maximum N impacts from field-wide production operations are substantially lower than the maximum impacts while field development is occurring. Given that field development operations will only occur in the first few years over the 30-year life of the project, the N deposition impacts shown in Table D-21 for the production scenario provide a more likely upper bound estimate of the long-term N deposition impacts resulting from the Proposed Action. Table D-21. Maximum Nitrogen Deposition Impacts at Class I and Sensitive Class II Areas

Maximum Emissions Scenario Production Scenario Location N Deposition N Deposition (kg/ha-yr) (kg/ha-yr) Black Canyon of the Gunnison Wilderness 0.0001 0.00003 Flat Tops Wilderness 0.0002 0.00004 Maroon Bells/Snowmass Wilderness 0.0020 0.00041 West Elk Wilderness 0.0012 0.00030 Raggeds Wilderness 0.0026 (52%) 0.00079 (16%) Colorado National Monument 0.0001 0.00001

In addition, potential changes in ANC, resulting from potential N and S deposition from Proposed Action source emissions, were calculated for nine sensitive lakes within the Flat Tops, Maroon Bells-Snowmass, Raggeds, and West Elk Wilderness areas. For all lakes, the estimated changes in ANC are all predicted to be less than the thresholds of concern. The estimated change in ANC is 0.005 percent at Avalanche Lake, 0.007 percent at Capitol Lake, 0.019 percent at Moon Lake, 0.005 percent at Lower Packtrail Pothole, 0.003 percent at Upper Packtrail Pothole, 0.004 percent at Ned Wilson Lake and 0.005 percent at South Golden Lake (compared to the 10% threshold), and a 0.017 μeq/L change at Deep Creek Lake and 0.002 μeq/L change at Upper Ned Wilson Lake (compared to a 1.0 μeq/L threshold for extremely sensitive lakes).

2.1.6 Regional Climate Change An overview of GHGs and climate change was previously presented in Section 1.4, including a national assessment of climate change and climate model projections for the State of Colorado that qualitatively describe the physical effects of climate change. As noted below, climate change analysis for this EA is limited to accounting for GHG emissions that would contribute incrementally to climate change and the potential effects previously discussed in Section 1.4. In the following, GHG emissions from the Proposed Action are quantitatively assessed and then compared to various scales (County, State, and national) of GHG emissions from oil and gas production. This establishes a frame of reference for the reader to analyze meaningfully the potential impacts of the local-scale project at the global-scale of climate change. Greenhouse Gas Emissions The maximum GHG emissions resulting from the Proposed Action development and production activities are estimated at 36,685 metric tpy (0.037 million metric tons [MMT]) of CO2e (Table D-13). To place the project GHG emissions in context, the calculated GHG emissions in year 2015 from oil and gas production in Delta and Gunnison counties and the State of Colorado were approximately 0.34 MMT and 145.2 MMT of CO2e, respectively (COGCC 2018, Office of Natural Resources Revenue [ONRR] 2017, EPA 2014, and IPCC 2013). Thus, the Proposed Action’s maximum GHG emissions from development and production would be approximately 10.8 percent of Delta and Gunnison counties and 0.03 percent of Colorado’s oil and gas production emissions. In addition, 0.037 MMT is approximately equivalent to 0.001 percent of the total 2015 U.S. calculated CO2e emissions from oil and gas production, 3,284 MMT. The degree of impact any single emitter of GHGs may have on the changes to biotic and abiotic systems that accompany climate change cannot be predicted using current analytical methods. Consequently, the extent that GHG emissions resulting from continued oil and gas development may contribute to global climate change, and the accompanying physical changes to natural systems, cannot be quantified or predicted. The degree to which any observable changes can, or would, be attributable to the Proposed Action cannot be predicted at this time.

As shown in Table D-13, the maximum annual downstream CO2e emissions are estimated at 12,953,068 metric tpy (12.95 MMT) per year. The emissions assume that all produced natural gas is transported offsite and combusted at facilities not associated with the project. These maximum annual downstream CO2e emissions would be comparable to the following 2015 oil and gas production emissions: 8.9 percent of Colorado emissions and 0.4 percent of total U.S. emissions (COGCC 2018, ONRR 2017, EPA 2014, and IPCC 2013). However, these downstream GHG emissions effects are included in the analysis described above along with a discussion on potential climate change impacts at the national, regional, and state levels.

3. CUMULATIVE

3.1 REGIONAL OZONE AND CUMULATIVE AIR QUALITY AND AQRV ANALYSES As part of the adaptive management strategy for managing air resources within the BLM planning areas, the BLM conducted a regional air modeling study to evaluate potential impacts on air quality from future mineral development in Colorado and northern New Mexico. The CARMMS (BLM 2017a) assesses predicted impacts on air quality and AQRVs from projected increases in oil and gas development. The CARMMS includes potential impacts using projections of oil and gas development out to year 2025 that reflect realistic estimations of development projections and technological improvements. The CARMMS includes cumulative impact assessments of future air quality and AQRVs resulting from development of Federal oil and gas resources within eight western Colorado BLM planning areas, four subareas of the Royal Gorge Field Office Planning Area, the Mancos Shale in the Tres Rios Field Office and Farmington, New Mexico Field Office Planning Areas, and Southern Ute Indian Tribe lands in

Colorado, as well as mining within these areas. In addition, CARMMS includes emissions from other regional sources including oil and gas emissions throughout the modeling domain, which encompasses all of Colorado, western Arizona, eastern Utah, and north-central New Mexico and extends into southern Wyoming, western Nebraska, western Kansas, western Oklahoma, and northwest Texas.

The CARMMS includes use of the Comprehensive Air-quality Model with extensions (CAMx) photochemical grid model (PGM) to estimate air quality and AQRV impacts for both a base case year (2011) and future year 2025. Emissions from all source types (anthropogenic and natural) are included in the CAMx modeling. As part of CARMMS, future year 2025 emissions estimates were developed for three development scenarios for the Colorado and New Mexico planning areas. These include year 2025 high, medium, and low oil and gas development scenarios. Modeling results from CARMMS are applicable for use in estimating potential ozone formation from regional emissions and project emissions, and for determining the maximum contribution of project sources to regional ozone formation. The CARMMS results are also applicable for project cumulative air quality and AQRV analyses. Given the level of oil and gas development within the BLM Uncompahgre Field Office (UFO) planning area projected through year 2025, the CARMMS 2025 High Oil and Gas Development Scenario is used to describe the potential ozone formation from NFMMDP project area sources and for summarizing the cumulative air quality and AQRV analyses. The CARMMS analysis included the following BLM planning areas in Colorado and northern New Mexico:  Roan Plateau portion of the Colorado River Valley Field Office  Colorado River Valley Field Office outside of the Roan Plateau  Grand Junction Field Office  Kremmling Field Office  Little Snake Field Office  Royal Gorge Field Office (includes 4 separate areas)  Tres Rios Field Office  Mancos Shale (includes portions of Tres Rios CO and Farmington NM Field Offices)  Uncompahgre Field Office  White River Field Office The oil and gas emissions from wells on BLM-administered (Federal) lands, non-Federal lands, and totals for Colorado BLM planning areas (the CARMMS 2025 High Development Scenario) and SUIT lands are shown in Table D-22. The maximum future year field-wide development and production emissions from project sources are as follows: 110.6 tpy NOx, 14.7 tpy VOC, 72.0 tpy CO, 0.4 tpy SO2, 32.5 tpy PM10 and 7.5 tpy PM2.5, and these emissions are included as part of the UFO planning area emissions and in the total Colorado BLM planning area emissions shown in Table D-22. Table D-22. Oil and Gas Emissions (tpy) from the Colorado BLM Planning Areas, SUIT Land and Mancos Shale for CARMMS 2025 High Development Scenario

Scenario NOx VOC CO SO2 PM10 PM2.5 Federal Wells 33,919 57,948 30,459 1,387 9,492 2,310 Non-Federal Wells 98,574 193,929 128,019 407 56,900 10,666 All Wells 132,493 251,877 158,478 1,794 66,392 12,977

Regional Ozone Impacts The CARMMS included estimates of future year regional ozone impacts using two analysis methods. One method uses the change in the PGM concentrations between the base year (DVB) (year 2011) and future year (DVF) (year 2025) simulations to scale observed ozone concentrations from monitoring sites to obtain projected future year ozone concentrations. This method utilized EPA’s Modeled Attainment Test Software (MATS) (Abt Associates 2012) projection tool with the CAMx 2011 Base Year and 2025 High Development Scenario ozone concentrations to estimate ozone impacts. The second method uses the absolute modeling results from the CAMx model to estimate ozone impacts. Figure D-2 presents the CAMx predicted ozone concentrations using MATS. The current year base design values (DVBs) indicate areas of ozone exceedances of the NAAQS (70 ppb) in and around Denver, places in Utah, Arizona, New Mexico, and Texas, with a maximum DVB of 109.6 ppb next to the Arizona/New Mexico border that is found to be caused by natural wild fire emissions (Figure D-2, top left). The base year DVBs also indicate that areas in the UFO planning area within and nearby the project area are below the NAAQS. For the 2025 High Development Scenario, the area of 2025 ozone DVF exceedances is substantially reduced from the base year with a peak DVF of 108.8 ppb (resulting from wild fires) near the Arizona/New Mexico border (Figure D-2, top right). The 2025 DVF – 2011 DVB difference plot (Figure D-2, bottom) shows the largest ozone reductions in the Denver metropolitan area. In the vicinity of the project area and throughout the UFO planning area, there are widespread ozone reductions in the 1.0 ppb to 3.0 ppb range. The CAMx absolute modeling results are presented in Figure D-3. The ozone NAAQS is defined as the 3-year average of the 4th highest daily maximum 8-hour ozone concentrations. Because CARMMS only has 1 year of modeling results, the 2025 4th highest daily maximum 8-hour ozone concentrations are used for the NAAQS comparison metric. Figure D-3 displays the 4th highest ozone concentrations for the 2011 Base Case and the 2025 High Development Scenario and their differences. For the 2011 Base Case, there are ozone exceedance areas in Colorado, eastern Utah, southern Wyoming, northeast Arizona, New Mexico, and Texas (Figure D-3, top left). The maximum ozone concentrations are estimated along the New Mexico/Arizona border and near Los Alamos of New Mexico (resulting from natural fires). The 2011 Base Case also indicates that areas within and nearby the project area in the UFO planning area are below the 70 ppb NAAQS. There are areas to the south of the project area near the southeast boundary of the UFO planning area that exceed the ozone NAAQS. In the 2025 High Development Scenario, the areas of ozone exceedances are reduced (Figure D-3, top right). The 2025 – 2011 ozone differences (Figure D-3, bottom) show decreases in almost all areas, with the greatest reduction (8.3 ppb) near Denver. In areas within and nearby the project area, small ozone increases up to 1 ppb (a level below the ozone NAAQS) and ozone reductions up to 2 ppb are modeled. Figure D-4 presents the maximum ozone contributions due to Federal land oil and gas emissions in the UFO planning area from the CAMx absolute model results. The maximum contribution to year 2025 regional ozone formation from the UFO planning area Federal land oil and gas sources is 0.8 ppb, which occurs near the project area. However, given that the UFO planning area Federal land oil and gas emissions include 501 tpy NOx and 393 tpy VOCs and that the maximum future year emissions from project sources include 110.6 tpy NOx and 14.7 tpy VOCs (combined development and production emissions), the contribution to regional ozone formation from project sources would likely be less.

Figure D-2. 2011 Ozone DVB (top left), 2025 Ozone DVF (top right), and 2025 DVF – 2011 Ozone DVB Differences Calculated Using MATS for the CARMMS 2025 High Development Scenario

Figure D-3. Fourth Highest Daily Maximum 8-hour Ozone Concentrations for the 2011 Base Case (top left), CARMMS 2025 High Development Scenario (top right), and 2025 Minus 2011 Differences (bottom)

Figure D-4. Contribution to Fourth Highest Daily Maximum Ozone Concentrations Due to Federal Land Oil and Gas Emissions within the UFO Planning Area for the CARMMS 2025 High Development Scenario

3.2 CUMULATIVE AIR QUALITY AND AQRV IMPACTS The CARMMS 2025 modeling analysis presented a scenario which included future year 2025 projected Federal and non-Federal oil and gas emissions throughout the 4-km grid CARMMS domain plus mining on BLM-administered lands in Colorado. This scenario, which includes future year oil and gas emissions from the 13 Colorado BLM planning areas plus the Mancos Shale area in Northern New Mexico, and SUIT lands in Colorado, is presented herein to describe cumulative impacts for the project. For the project cumulative analysis, these cumulative oil and gas emissions and mining emissions are considered reasonably foreseeable development (RFD) emissions. The CARMMS included impact assessments at 26 PSD Class I and 58 sensitive Class II areas, and at 58 lakes throughout the CARMMS modeling domain, which included each of the Class I and Class II areas and lakes that have been included in the project CALPUFF impacts analyses. For the project cumulative assessment, the CARMMS impacts are presented for the PSD Class I and sensitive Class II areas and lakes that were included in the CALPUFF analyses.

3.2.1 Air Quality Impacts

The modeled concentrations of NO2, SO2, PM10, and PM2.5 at Class I and sensitive Class II areas resulting from cumulative RFD source emissions are provided in Table D-23 for comparison to applicable PSD Class I and Class II increments. All values are well below the PSD Class I and Class II increments. Table D-23. Modeled Cumulative Pollutant Concentrations (CARMMS 2025 High Development Scenario) at PSD Class I and Sensitive Class II Areas (µg/m3)

Averaging Location Pollutant Concentration PSD Increment Time

NO2 Annual 0.123 2.5 3-hour 0.121 25

SO2 24-hour 0.077 5

Black Canyon of the Annual 0.006 2 Gunnison National Park 24-hour 0.463 8 PM10 Annual 0.061 4 24-hour 0.339 2 PM2.5 Annual 0.038 1

NO2 Annual 0.332 2.5 3-hour 0.270 25

SO2 24-hour 0.118 5

Colorado National Annual 0.013 2 Monument 24-hour 0.722 8 PM10 Annual 0.109 4 24-hour 0.544 2 PM2.5 Annual 0.059 1

NO2 Annual 0.343 2.5 Flat Tops Wilderness SO2 3-hour 0.426 25

Averaging Location Pollutant Concentration PSD Increment Time 24-hour 0.145 5 Annual 0.025 2 24-hour 0.367 8 PM10 Annual 0.098 4 24-hour 0.133 2 PM2.5 Annual 0.041 1

NO2 Annual 0.333 2.5 3-hour 0.123 25

SO2 24-hour 0.054 5

Maroon Bells/Snowmass Annual 0.006 2 Wilderness 24-hour 0.333 8 PM10 Annual 0.120 4 24-hour 0.216 2 PM2.5 Annual 0.061 1

NO2 Annual 0.934 25 3-hour 0.103 25

SO2 24-hour 0.040 5 Annual 0.006 2 Raggeds Wilderness 24-hour 0.564 8 PM10 Annual 0.251 4 24-hour 0.315 2 PM2.5 Annual 0.102 1

NO2 Annual 0.132 2.5 3-hour 0.112 25

SO2 24-hour 0.048 5 Annual 0.004 2 West Elk Wilderness 24-hour 0.326 8 PM10 Annual 0.078 4 24-hour 0.230 2 PM2.5 Annual 0.056 1

3.2.2 Air Quality Related Value Impacts Visibility Impacts Visibility impacts due to RFD oil and gas emissions and mining emissions were examined following the procedures provided by the USFWS and NPS (USFWS and NPS 2012). These procedures use EPA’s MATS to project base year observed visibility impairment (from IMPROVE monitoring sites) for the best 20 percent (B20 percent) and worst 20 percent (W20 percent) days to the future year using the 2011 Base Case and 2025 High Development Scenario modeling results (which include contributions from all source categories (including anthropogenic and natural) with and without emissions from RFD sources. Tables D-24 and D-25 display the cumulative visibility results for the 2025 High Development Scenario and RFD sources for W20 percent and B20 percent days, respectively. These tables indicate the IMPROVE sites used for the base year observed visibility data for each of the Class I and sensitive Class II areas analyzed. The IMPROVE sites used include the White River National Forest (Maroon Bells- Snowmass Wilderness) and Weminuche Wilderness sites (WHRI1 and WEMI1). The data from the closest IMPROVE site was used for each Class I and sensitive Class II area. As is indicated in Table D-24, from the 2011 Base Year to the 2025 High Development Scenario future year, the W20 percent visibility metric is estimated to improve at each of the Class I and sensitive Class II areas. The biggest improvement is a reduction of 0.23 dv that occurs at Colorado National Monument and at the Flat Tops, Maroon Bells-Snowmass, Raggeds, and West Elk wilderness areas which goes from 8.47 dv in 2011 to 8.24 dv in 2025. RFD emissions are estimated to contribute a maximum of 0.11 dv to the 2025 W20 percent days visibility at these areas. Cumulative visibility results at Class I and sensitive Class II areas for the B20 percent days are provided in Table D-25. From 2011 to 2025, the B20 percent days visibility is estimated to improve in all Class I and sensitive Class II areas. The largest B20 percent visibility improvement is a 0.19 dv reduction that occurs at Colorado National Monument and at the Flat Tops, Maroon Bells-Snowmass, Raggeds, and West Elk wilderness areas which goes from 0.51 dv in 2011 to 0.32 dv in 2025. The maximum contribution from RFD sources to 2025 B20 percent visibility metrics is 0.11 dv at these areas. Table D-24. Cumulative Visibility Results (Δdv) for Worst 20 percent Visibility Days at PSD Class I and Sensitive Class II Areas for the Base Year (2011) and 2025 High Development Scenario, All Emissions and Contributions from RFD Sources

2025 High IMPROVE 2011 2025 Contribution Location State Improvement Site Base High from RFD from 2011 Black Canyon of the CO WEMI1 9.77 9.55 0.22 0.03 Gunnison National Park Colorado National CO WHRI1 8.47 8.24 0.23 0.11 Monument Flat Tops Wilderness CO WHRI1 8.47 8.24 0.23 0.11 Maroon Bells/Snowmass CO WHRI1 8.47 8.24 0.23 0.11 Wilderness Raggeds Wilderness CO WHRI1 8.47 8.24 0.23 0.11 West Elk Wilderness CO WHRI1 8.47 8.24 0.23 0.11

Table D-25. Cumulative Visibility Results (Δdv) for Best 20 percent Visibility Days at PSD Class I and Sensitive Class II Areas for the Base Year (2011) and 2025 High Development Scenario, All Emissions and Contributions from RFD Sources

2025 High IMPROVE 2011 2025 Contribution Location State Improvement Site Base High from RFD from 2011 Black Canyon of the Gunnison National CO WEMI1 2.06 1.89 0.17 0.04 Park Colorado National CO WHRI1 0.51 0.32 0.19 0.10 Monument Flat Tops Wilderness CO WHRI1 0.51 0.32 0.19 0.10 Maroon Bells/Snowmass CO WHRI1 0.51 0.32 0.19 0.10 Wilderness Raggeds Wilderness CO WHRI1 0.51 0.32 0.19 0.10 West Elk Wilderness CO WHRI1 0.51 0.32 0.19 0.10

Deposition Impacts Potential atmospheric deposition impacts within Class I and sensitive Class II areas were calculated for cumulative RFD sources and are shown in Table D-26. The maximum direct total (wet and dry) N and S depositions are predicted to be well below the cumulative analysis thresholds of 2.3 kg/ha-yr for nitrogen and 5 kg/ha-yr for sulfur at all Class I and sensitive Class II areas. The maximum total nitrogen deposition rate (0.294 kg/ha-yr) occurs at the Maroon Bells – Snowmass Wilderness Area is approximately 13 percent of the cumulative analysis threshold. The maximum total sulfur deposition rate (0.013 kg/ha-yr) is approximately 0.3 percent of the cumulative analysis threshold and it occurs at the Flat Tops Wilderness Area. Table D-26. Cumulative RFD Nitrogen and Sulfur Deposition Impacts (CARMMS 2025 High Development Scenario) at PSD Class I and Sensitive Class II Areas

Maximum N Deposition Maximum S Deposition Location (kg/ha-yr) (kg/ha-yr) Black Canyon of the Gunnison National Park 0.054 0.002 Colorado National Monument 0.066 0.001 Flat Tops Wilderness 0.194 0.013 Maroon Bells/Snowmass Wilderness 0.294 0.012 Raggeds Wilderness 0.283 0.012 West Elk Wilderness 0.164 0.007

Potential changes in ANC from baseline conditions resulting from potential N and S deposition from cumulative RFD source emissions were calculated for nine sensitive lakes within the Class I and sensitive Class II wilderness areas. The estimated change in ANC for each lake is shown in Table D-27. For the lakes with ANC values greater than 25 μeq/L the estimated changes in ANC are all predicted to be below the applicable thresholds of concern (less than a 10 percent change in ANC). The greatest percent change is 3.7 percent at Lower Packtrail Pothole. At the two lakes with background ANC values equal to or less

than 25 µeq/L (Upper Ned Wilson Lake and Deep Creek Lake) the predicted changes in ANC are above the applicable threshold of concern 1.0 μeq/L. The estimated change in ANC is 1.1 µeq/L at Upper Ned Wilson Lake and 3.4 µeq/L at Deep Creek Lake. Table D-27. Cumulative RFD Impacts on Lakes (CARMMS 2025 High Development Scenario) within the Class I and Sensitive Class II Areas

)

yr) yr)

- -

S Wilderness Area Sensitive Lake N

ANC ANC

Percentile

percent

(µeq/L) (µeq/L)

Change Change

Relative

Absolute

(

(kg/ha (kg/ha

Deposition Deposition

Lowest ANC Value Ned Wilson Lake 39.0 0.114 0.008 2.8 n/a Upper Ned Wilson Lake 12.9 0.114 0.008 n/a 1.1 Flat Tops Lower Packtrail Pothole 29.7 0.114 0.008 3.7 n/a Upper Packtrail Pothole 48.7 0.114 0.008 2.2 n/a Avalanche Lake 158.8 0.117 0.004 0.6 n/a

Maroon Bells Capitol Lake 154.4 0.197 0.008 1.0 n/a Moon Lake 53.0 0.197 0.008 2.9 n/a Raggeds Deep Creek Lake 20.6 0.263 0.007 n/a 3.4 West Elk South Golden Lake 111.4 0.078 0.003 0.9 n/a

3.2.3 Monitoring In April 2018, BLM Colorado began operation of an air quality monitor at Paonia High School in the North Fork Valley. The monitoring data are used to evaluate the effect of new Federal oil and gas development in the area on air quality in the North Fork Valley, and will also support future impact assessments of oil and gas development proposals in the area. As of late August 2018, the BLM has been collaborating with operators in the area to obtain oil and gas development information for comparison with the North Fork Valley (Paonia) monitoring data. The BLM will continue to monitor air quality for the North Fork Valley as new oil and gas development in the area continues.

3.2.4 Regional Climate Change – Greenhouse Gas Impacts Continued field development, operation of well site equipment, and associated vehicle traffic would result in minor cumulative contributions to atmospheric GHGs. Natural gas produced under the Proposed Action would be available for consumer or commercial use. The downstream combustion of natural gas would generate GHGs, which, in industrial settings, would be controlled through applicable GHG emission control regulations (emissions standards) or by applicable air permit requirements. Other industrial operations in the area would also contribute to GHG emissions through the use of carbon fuels (natural gas, liquefied petroleum gas, and diesel), and through the use of electricity produced using carbon fuels. Other anthropogenic activities such as residential wood and open burning, as well as biogenic sources, also contribute GHGs to the atmosphere. These would be more dispersed, but also more sustained, than the emissions from this oil and gas development, which has a finite lifespan. Policies regulating specific GHG concentration levels and their potential for significance with respect to regional or global impacts have not been established. As stated in Section 2.1.6, the maximum GHG emissions resulting from the Proposed Action development and production activities are estimated at

36,685 metric tpy (0.037 MMT) of CO2e (Table D-13). To place the project GHG emissions in context, the calculated GHG emissions in year 2015 from oil and gas production in Delta and Gunnison counties and the State of Colorado were approximately 0.34 MMT and 145.2 MMT of CO2e, respectively (COGCC 2018, ONRR 2017, EPA 2014, and IPCC 2013). Thus, the Proposed Action’s maximum GHG emissions from development and production would be approximately 10.8 percent of Delta and Gunnison counties and 0.03 percent of Colorado’s oil and gas production emissions. In addition, 0.037 MMT of CO2e is approximately equivalent to 0.001 percent of the total 2015 U.S. calculated CO2e emissions from oil and gas production, 3,284 MMT of CO2e.

As shown in Table D-13, the maximum annual downstream CO2e emissions are estimated at 12,943,068 metric tpy (12.95 MMT) per year. The emissions assume that all produced natural gas is transported offsite and combusted at facilities not associated with the project. These maximum annual downstream CO2e emissions would be comparable to the following 2015 oil and gas production emissions: 8.9 percent of Colorado emissions and 0.4 percent of total U.S. emissions (COGCC 2018, ONRR 2017, EPA 2014, and IPCC 2013). However, these downstream GHG emissions effects are further described in Sections 1.4 and 2.1.6. According to ONRR’s U.S. Department of the Interior data, the country’s total Federal (onshore) oil and gas production in 2015 was approximately 191 million bbl of oil and 3,482,000 MMCF of natural gas, which accounted for 5.6 percent and 10.6 percent of the nation’s total production (combined Federal and non-Federal), respectively (ONRR 2017). Similarly, Colorado’s Federal oil and gas production represented 0.66 percent and 13.7 percent of the nation’s Federal oil and gas production, and 0.15 percent and 2.0 percent of the nation’s total oil and gas production (Federal and non-Federal). For this analysis, the BLM makes the conservative assumption that all of the oil and gas produced in the U.S. is combusted within the larger sectors of the economy (electricity generation, transportation, industry).

The U.S. produced 6,587 MMT of CO2e emissions in 2015 according to EPA’s Inventory of U.S. Greenhouse Gas Emissions and Sinks (EPA 2017c). The calculated 2015 CO2e emissions from Federal oil and gas development in Colorado (38.4 MMT) and across the nation (273 MMT onshore and 592 MMT onshore and offshore combined) represent 0.58 percent, 4.1 percent (onshore), and 9.0 percent, respectively, of the nation’s total GHG emissions (ONRR 2017, EPA 2014, IPCC 2013). A recent U.S. Geological Survey report (Merrill et al., 2018) provides GHG emissions estimates associated with the extraction and end-use combustion of fossil fuels produced on federal lands in the U.S. The report indicates that in 2014 the nationwide emissions from fossil fuels produced on federal lands were 1,279.0 MMT CO2e for CO2, 47.6 MMT CO2e for CH4, and 5.5 MMT CO2e for N2O. These GHG emissions represent decreases from 2005 levels (6.1% for CO2, 10.5% for CH4, and 20.3% for N2O).

At a global scale, the U.S. and the world produced 6,344 MMT and 53,530 MMT, respectively, of CO2e emissions in 2012 (The World Bank Group 2017). In other words, the U.S. produced 12 percent of the global GHG emissions. The maximum direct project and downstream CO2e emissions from the Proposed Action (12.99 MMT) represents approximately 0.02% of global GHG emissions on an annual basis. The maximum direct project and downstream CO2e emissions over the life of the project, assuming a 30-year life of the project, are estimated as 0.8 MMT and 71.0 MMT, respectively. These total direct project and downstream emissions (71.8 MMT), over the life of the project, represent approximately 3.7E-09% of total global CO2e emissions (1.94E+12 MMT) used for climate modeling to estimate climate change impacts in year 2050 (described above under “National Assessment of Climate Change”) using the RCP 4.5 scenario. In addition, BLM’s Greenhouse Gas and Climate Change Report (2017b) is incorporated by reference to describe potential GHG emissions for various future years and energy development scenarios. For that report, GHG emissions were calculated for two energy development scenarios (“normal” and high rates of energy production and consumption) for projected years 2020 and 2030 for each BLM State including

Colorado. GHG emissions estimates for Federal and non-Federal energy related production (i.e., upstream and midstream) and consumption (i.e., downstream) were developed for coal, oil, natural gas, and liquefied natural gas. The report used production and consumption data presented in the Energy Information Administration 2016 Annual Energy Outlook to determine growth factors to estimate normal / high inventories. The following summarizes the projected 2020 and 2030 GHG emissions and trends for Colorado Federal resources:  Colorado Federal emissions due to oil production and end-use consumption are projected to remain almost static from baseline year (2014) to future years (2020 and 2030) with a slight decrease in GHG emissions for both the normal and high scenarios.  Colorado Federal emissions due to natural gas production and downstream consumption are projected to increase into year 2030 for both the normal and high scenarios from 42.91 million metric tons of carbon dioxide equivalents (MMT CO2e) in base year 2014 to 44.55 and 45.03 MMT CO2e in the 2030 normal and high scenarios, respectively.  Colorado Federal emissions due to natural gas liquids are projected to decrease from baseline year 2014 to projected year 2030 by approximately 25 to 30% for both scenarios. Within the BLM emissions profile, the relative mixture of coal, oil, and natural gas is expected to change from baseline year to 2030. Coal production is expected to decrease and natural gas production is expected to increase by year 2030. The report also provides a supplemental “Understanding Future Climate Impacts” section and explains that projected changes in climate are driven by the cumulative emissions, not the emissions profile. When considering the cumulative emissions on a global scale, the sub-national emissions profile (by BLM as a whole, a BLM field office, etc.) is one of many emission contributions. Any single contribution on a sub-national scale is dwarfed by the large number of comparable national and sub- national contributors on a global scale. The relative contribution of GHG emissions from production and consumption of Federal minerals will vary depending on contemporaneous changes in other sources of GHG emissions. It is very unlikely that the global cumulative emissions will be strongly influenced by a single contributor (e.g., UFO) at a national or sub-national scale. However, each GHG emissions source contributes, on a relative basis, to global emissions and long-term climate impacts. 3.3 SOCIAL COSTS OF CARBON AND SOCIAL COSTS OF METHANE (SCC/SCM) Comments were received that the BLM should utilize social cost of carbon (SCC) and social cost of methane (SCM) protocols. These protocols are estimates of the economic damages associated with an increase in carbon dioxide/methane emissions. BLM is not using the SCC/SCM protocols for this EA for several reasons. Estimates of SCC/SCM are just one approach that an agency can take to examine climate consequences from greenhouse gas emissions associated with the proposed action. The approach taken by the BLM for this EA to examine climate consequences included quantification of the potential GHG emissions (including indirect and downstream GHG emissions), comparison of those emissions to various scales of GHG emissions from oil and gas production, and a qualitative discussion of potential climate impacts at global, national, regional and statewide scales (see Sections 1.4, 2.1.6. and 3.2.4). The BLM took this approach because climate change and potential climate impacts, in and of themselves, are often not well understood by the general public (Etkin and Ho 2007, National Research Council 2009). This is in part due to the challenges associated with communicating about climate change and climate impacts, stemming in part from the fact that most causes are invisible factors (such as greenhouse gases) and there is a long lag time and geographic scale between causes and effects (National Research Council 2010). Research indicates that for difficult environmental issues such as climate change, most people more readily understand if the issue is brought to a scale that is relatable to their everyday life (Dietz 2013); when the science and technical aspects are presented in an engaging way such as narratives about the potential implications of the climate impacts (Corner, Lewandowsky, Phillips, and Roberts 2015); use

examples and make information relevant to the audience while also linking the local and global scales (National Research Council 2010). The approach taken by the BLM recognizes that the adverse environmental impacts associated with the development and use of fossil fuels on climate change, provides potential GHG emission estimates, and discusses potential climate change impacts qualitatively. This approach effectively informs the decision-maker and the public regarding the potential for GHG emissions and the potential implications of climate change. It presents the data and information in a manner that follows many of the guidelines for effective climate change communication developed by the National Academy of Sciences (National Research Council 2010) by making the information more readily understood and relatable to the decision-maker and the general public. Furthermore, NEPA does not require an economic cost-benefit analysis (40 C.F.R. § 1502.23), although NEPA does require consideration of “effects” that include “economic” and “social” effects (40 C.F.R. 1508.8(b)). SCC/SCM estimates are a type of cost-benefit analysis. The EA qualitatively discusses socioeconomic impacts such as potential revenue and the changes in economic activity that could occur related to the proposed action. The potential economic activity such as royalty revenue, jobs, and income associated with oil and gas development should not be mischaracterized as “economic benefits” of the proposed action. Effects associated with production or any other forms of economic activities (often expressed in terms of employment, income, and output) are the results from an economic impact analysis. Cost-benefit analyses and economic impact analyses are very different methods that are focused on quantifying/monetizing different measures (social welfare and economic activity respectively) and are based upon differing assumptions and terminology and are not interchangeable (Watson et al. 2007, Kotchen 2011). Based upon their views and values, people may perceive this increased economic activity as a “positive” impact that they desire to have occur. However, that is distinct from being an “economic benefit” as defined in economic theory and methodology (Watson et al. 2007, Kotchen 2011). Therefore, it is critical to distinguish that how people may perceive an economic impact is not the same as, nor should it be interpreted as, a cost or a benefit as defined in an economic cost-benefit analysis. Without any other monetized benefits or costs reported, monetized estimates of SCC/SCM would be presented in isolation, without any context for comparison. Quantifying only the costs of oil and gas development by using SCC/SCM metrics but not the benefits (as measured by the economic value of the proposed oil and gas development and production generally equaling the price of oil and gas minus the cost of producing, processing, and transporting the minerals) would yield information that is both inaccurate and not useful for the decision-maker, especially given that there are no current criteria or thresholds that determine a level of significance for SCC/SCM monetary values.

4. REFERENCES

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