Lookout Solar Park Final Environmental Assessment Custer and Oglala Lakota Counties, South Dakota DOE/EA-2075 July 2021 Lookout Solar Park I Environmental Assessment Table of Contents 1. INTRODUCTION AND BACKGROUND .................................................................................1 1.1 Purpose and Need for WAPA’s Federal Action ........................................................................ 1 1.2 Lookout Solar’s Purpose and Need .......................................................................................... 1 1.3 Public Involvement .................................................................................................................... 1 1.4 Tribal Consultation .................................................................................................................... 3 2. PROPOSED ACTION AND ALTERNATIVES CONSIDERED .............................................2 2.1 No Action Alternative ................................................................................................................. 2 2.2 Alternatives Considered but Eliminated from Further Study..................................................... 2 2.3 Proposed Action ........................................................................................................................ 2 2.3.1 Solar Arrays .................................................................................................................. 3 2.3.2 Access Roads ............................................................................................................... 3 2.3.3 Construction Timing ...................................................................................................... 4 2.3.4 Operation and Maintenance ......................................................................................... 4 2.3.5 Decommissioning and Reclamation ............................................................................. 4 3. AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES ...................7 Soils and Geology ..................................................................................................................... 7 3.1.1 Environmental Impacts: Proposed Action ................................................................... 8 3.1.2 Environmental Impacts: No Action Alternative ............................................................ 8 Paleontology .............................................................................................................................. 8 3.2.1 Environmental Impacts: Proposed Action ................................................................... 9 3.2.2 Environmental Impacts: No Action Alternative ............................................................ 9 Air Quality and Emissions ......................................................................................................... 9 3.3.1 Environmental Impacts: Proposed Action ................................................................. 10 3.3.2 Environmental Impacts: No Action Alternative .......................................................... 11 Water Resources ..................................................................................................................... 11 3.4.1 Environmental Impacts: Proposed Action ................................................................. 20 3.4.2 Environmental Impacts: No Action Alternative .......................................................... 21 Threatened and Endangered Species .................................................................................... 21 3.5.1 Environmental Impacts: Proposed Action and No Action Alternative ....................... 24 Fish and Wildlife ...................................................................................................................... 24 3.6.1 Environmental Impacts: Proposed Action ................................................................. 28 3.6.2 Environmental Impacts: No Action Alternative .......................................................... 30 Cultural Resources .................................................................................................................. 30 3.7.1 Environmental Impacts: Proposed Action ................................................................. 30 3.7.2 Environmental Impacts: No Action Alternative .......................................................... 31 Land Use ................................................................................................................................. 31 3.8.1 Environmental Impacts: Proposed Action ................................................................. 32 3.8.2 Environmental Impacts: No Action Alternative .......................................................... 32 Socioeconomic Conditions and Environmental Justice .......................................................... 32 3.9.1 Environmental Impacts: Proposed Action ................................................................. 34 3.9.2 Environmental Impacts: No Action Alternative .......................................................... 35 Lookout Solar Park I Environmental Assessment Vegetation ............................................................................................................................... 35 3.10.1 Environmental Impacts: Proposed Action ................................................................. 39 3.10.2 Environmental Impacts: No Action Alternative .......................................................... 39 Visual Resources .................................................................................................................... 39 3.11.1 Environmental Impacts: Proposed Action ................................................................. 40 3.11.2 Environmental Impacts: No Action Alternative .......................................................... 40 Roads and Traffic .................................................................................................................... 43 3.12.1 Environmental Impacts: Proposed Action ................................................................. 43 3.12.2 Environmental Impacts: No Action Alternative .......................................................... 43 Cumulative Impacts ................................................................................................................. 45 4. LIST OF PREPARERS ...............................................................................................................46 5. REFERENCES .............................................................................................................................47 List of Tables Table 1-1. Public Scoping Comments ....................................................................................................... 2 Table 2-1. Anticipated Surface Disturbance .............................................................................................. 3 Table 3-1. Geology Summary of the Project Area .................................................................................... 7 Table 3-2. Soil Series Characteristics within the Project Area .................................................................. 7 Table 3-3. Emission Sources.................................................................................................................... 10 Table 3-4. Federal T&E Species .............................................................................................................. 21 Table 3-5. State T&E Species .................................................................................................................. 27 Table 3-6. Minority Population Characteristics ....................................................................................... 33 Table 3-7. Average Income and Poverty Rates (2010-2017) .................................................................. 33 Table 3-8. Vegetation in the Study Area ................................................................................................. 36 Table 4-1. Preparers of the EA ................................................................................................................ 46 Table 4-2. Individuals Who Provided Technical Support, Management, and/or Review of the EA ....... 46 List of Figures Figure 1-1: Site Location Map ................................................................................................................... 1 Figure 2-1: Project Area Overview ............................................................................................................ 5 Figure 2-2: Solar Generating Facility Overview ....................................................................................... 6 Figure 3-1: Aquatic Resource Inventory of the Project Area and Transmission Line Route .................. 12 Figure 3-2: Aquatic Resources of the Project Area ................................................................................. 13 Figure 3-3: Cheyenne River Crossing...................................................................................................... 14 Figure 3-4: Angostura Canal Crossing .................................................................................................... 15 Figure 3-5: Cottonwood Creek Crossing ................................................................................................. 16 Figure 3-6: Cottonwood Cutoff Wetland Crossing .................................................................................