Environmental Assessment for Public Review DOE/EA-1617 Lovell-Yellowtail and Basin-Lovell Transmission Line Rebuild Project Big Horn County, Wyoming and Big Horn and Carbon Counties, Montana U.S. Department of Energy Western Area Power Administration Rocky Mountain Region Loveland, Colorado Cooperating Agencies: U.S. Department of the Interior, National Park Service July 2011 Montana Department of Environmental Quality Environmental Assessment for Public Review DOE/EA-1617 Lovell-Yellowtail and Basin-Lovell Transmission Line Rebuild Project Big Horn and Carbon Counties, Montana and Big Horn County, Wyoming U.S. Department of Energy Western Area Power Administration Rocky Mountain Region Loveland, Colorado Cooperating Agencies: U.S. Department of the Interior, National Park Service July 2011 Montana Department of Environmental Quality THIS PAGE LEFT INTENTIONALLY BLANK Table of Contents Table of Contents SUMMARY ............................................................................................................................... 1 1.0 INTRODUCTION ............................................................................................................ 1.1-1 1.1 BACKGROUND ............................................................................................................. 1.1-1 1.2 PURPOSE AND NEED FOR THE PROJECT ............................................................... 1.2-2 1.3 DECISIONS TO BE MADE ........................................................................................... 1.3-2 1.4 COOPERATING AGENCIES ........................................................................................ 1.4-3 1.5 SCOPING RESULTS ...................................................................................................... 1.5-4 2.0 ALTERNATIVES INCLUDING THE PROPOSED PROJECT ................................ 2.0-1 2.1 DESCRIPTION OF THE PROPOSED PROJECT ......................................................... 2.1-1 2.1.1 General Description of the Proposed Project ........................................................... 2.1-1 2.1.2 Proposed Project Design Requirements ................................................................... 2.1-5 2.1.3 Description of Proposed Transmission Facilities .................................................... 2.1-5 2.1.4 Access Roads ........................................................................................................... 2.1-9 2.1.5 Proposed Substation Facilities and Modifications ................................................. 2.1-10 2.1.6 Construction Practices ........................................................................................... 2.1-10 2.1.7 Operation and Maintenance Practices.................................................................... 2.1-13 2.1.8 Western‘s Standard Construction Project Practices and Project Specific Mitigation Measures ....................................................................................................................... 2.1-13 2.2 ALTERNATIVES TO THE PROPOSED PROJECT ................................................... 2.2-18 2.2.1 Alternatives Considered and Eliminated ............................................................... 2.2-18 2.2.2 Structure Alternatives ............................................................................................ 2.2-18 2.2.3 No Action Alternative............................................................................................ 2.2-26 3.0 AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES ..... 3.0-1 3.1 OVERVIEW OF ANALYSIS APPROACH ................................................................... 3.1-1 3.2 CLIMATE AND AIR QUALITY ................................................................................... 3.2-1 3.2.1 Affected Environment ............................................................................................. 3.2-1 3.2.2 Environmental Impacts and Mitigation Measures ................................................... 3.2-3 3.3 GEOLOGY AND PALEONTOLOGY ........................................................................... 3.3-4 3.3.1 Affected Environment ............................................................................................. 3.3-4 3.3.2 Environmental Impacts and Mitigation Measures ................................................... 3.3-6 3.4 WATER RESOURCES AND FLOODPLAINS ............................................................. 3.4-9 3.4.1 Affected Environment ............................................................................................. 3.4-9 3.4.2 Environmental Impacts and Mitigation Measures ................................................. 3.4-18 3.5 WETLANDS AND OTHER WATERS OF THE U.S. ................................................. 3.5-23 3.5.1 Affected Environment ........................................................................................... 3.5-24 3.5.2 Environmental Impacts and Mitigation Measures ................................................. 3.5-25 3.6 UPLAND VEGETATION ............................................................................................ 3.6-30 3.6.1 Affected Environment ........................................................................................... 3.6-30 3.6.2 Environmental Impacts and Mitigation Measures ................................................. 3.6-35 3.7 SOILS 3.7-41 3.7.1 Affected Environment ........................................................................................... 3.7-42 3.7.2 Environmental Impacts and Mitigation Measures ................................................. 3.7-43 3.8 WILDLIFE .................................................................................................................... 3.8-51 3.8.1 Affected Environment ........................................................................................... 3.8-51 3.8.2 Environmental Impacts and Mitigation Measures ................................................. 3.8-68 3.9 THREATENED, ENDANGERED, AND OTHER SPECIAL STATUS SPECIES ..... 3.9-75 LV-YT and BA-LV Transmission Line Rebuild Table of Contents i Table of Contents 3.9.1 Affected Environment ........................................................................................... 3.9-76 3.9.2 Environmental Impacts and Mitigation Measures ................................................. 3.9-78 3.10 CULTURAL RESOURCES ........................................................................................ 3.10-81 3.10.1 Affected Environment ......................................................................................... 3.10-82 3.10.2 Environmental Impacts and Mitigation Measures ............................................... 3.10-82 3.11 LAND USE – EXISTING AND PLANNED .............................................................. 3.11-92 3.11.1 Affected Environment ......................................................................................... 3.11-92 3.11.2 Environmental Impacts and Mitigation Measures ............................................. 3.11-100 3.12 VISUAL RESOURCES ............................................................................................ 3.12-104 3.12.1 Affected Environment ....................................................................................... 3.12-104 3.12.2 Environmental Impacts and Mitigation Measures ............................................. 3.12-111 3.13 SOCIOECONOMICS AND ENVIRONMENTAL JUSTICE .................................. 3.13-131 3.13.1 Affected Environment ....................................................................................... 3.13-131 3.13.2 Environmental Impacts and Mitigation Measures ............................................. 3.13-135 3.14 TRANSPORTATION ............................................................................................... 3.14-137 3.14.1 Affected Environment ....................................................................................... 3.14-137 3.14.2 Environmental Impacts and Mitigation Measures ............................................. 3.14-138 3.15 PUBLIC HEALTH, SAFETY, AND NOISE ........................................................... 3.15-141 3.15.1 Affected Environment ....................................................................................... 3.15-142 3.15.2 Environmental Impacts and Mitigation Measures ............................................. 3.15-142 3.16 CUMULATIVE IMPACTS ...................................................................................... 3.16-144 3.16.1 Reasonably Foreseeable Development .............................................................. 3.16-144 3.16.2 Cumulative Environmental Impacts for Resource Topic................................... 3.16-145 3.17 INTENTIONAL DESTRUCTIVE ACTS ................................................................. 3.17-149 4.0 LIST OF PREPARERS ...................................................................................................... 4-1 5.0 CONSULTATION AND COORDINATION ................................................................... 5-1 6.0 REFERENCES .................................................................................................................... 6-1 APPENDIX A - PROPOSED LV-YT AND BA-LV TRANSMISSION LINE REBUILD LOCATION MAP EXHIBITS ..................................................................................................... 1 APPENDIX B -INTERAGENCY CONSULTATION ...............................................................