U.S. Department of the Interior Bureau of Land Management Final Environmental Assessment DOI-BLM-NV-S010-2010-0091-EA November 2014 Southern Nevada Intertie Project APPLICANT Great Basin Transmission, LLC GENERAL LOCATION Clark County, Nevada BLM CASE FILE SERIAL NUMBER N-086359 PREPARING OFFICE U.S. Department of the Interior Bureau of Land Management Las Vegas Field Office 4701 N. Torrey Pines Drive Las Vegas, Nevada 89130 Phone: (702) 515-5172 Fax: (702) 515-5010 This page intentionally left blank. TABLE OF CONTENTS Chapter 1. Introduction .......................................................................................................... 1-1 1.1. Identifying Information ...................................................................................... 1-2 1.1.1. Title, EA Number, and Type of Project .............................................. 1-2 1.1.2. Location of Proposed Action ............................................................... 1-2 1.1.3. Name and Location of Preparing Office ............................................. 1-2 1.1.4. Identify the Case File Number ............................................................ 1-2 1.1.5. Applicant Name ................................................................................... 1-2 1.2. Purpose and Need for Action ............................................................................. 1-2 1.2.1. Background ......................................................................................... 1-2 1.2.2. BLM Purpose and Need ...................................................................... 1-3 1.2.3. Reclamation Purpose and Need ........................................................... 1-3 1.3. Decisions to be Made ......................................................................................... 1-3 1.4. BLM and Reclamation Policies, Plans, Authorizing Actions, and Permit Requirements ...................................................................................................... 1-4 1.4.1. BLM .................................................................................................... 1-4 1.4.2. Reclamation ......................................................................................... 1-5 1.4.3. NEPA Regulations and Guidance ....................................................... 1-5 1.4.4. Indian Trust Assets .............................................................................. 1-7 1.4.5. Indian Sacred Sites .............................................................................. 1-7 Chapter 2. Proposed Action and Alternatives ....................................................................... 2-1 2.1. Introduction ........................................................................................................ 2-1 2.2. No Action Alternative ........................................................................................ 2-1 2.3. Proposed Action ................................................................................................. 2-1 2.4. Alternative 1 – Using 18 Miles of Open Position on the Existing Harry Allen to Mead Double-circuit Structures ........................................................... 2-2 2.5. River Mountains Alternative Routing Area ....................................................... 2-7 2.6. Dutchman Pass Alternative Routing Area .......................................................... 2-7 2.7. Alternatives Considered but Eliminated ............................................................. 2-7 2.7.1. Crystal Substation Alternative Routing Area ...................................... 2-7 2.7.2. Alternative Paralleling the Northern 5 Miles of the Harry Allen to Mead 500 kV Line ............................................................................... 2-8 2.7.3. Southwest Intertie Project Interconnection Alternative ...................... 2-8 2.7.4. Mead Substation Alternative ............................................................... 2-8 2.8. Project Elements Common to the Proposed Action and All Action Alternatives ........................................................................................................ 2-8 2.8.1. Facilities Associated with the Proposed Project and Action Alternatives ......................................................................................... 2-8 2.8.2. Construction ...................................................................................... 2-17 2.8.3. Operation and Maintenance ............................................................... 2-24 2.8.4. Termination and Restoration ............................................................. 2-25 Chapter 3. Affected Resources .............................................................................................. 3-1 3.1. Air Quality .......................................................................................................... 3-2 3.1.1. Environmental Setting ......................................................................... 3-2 Table of Contents i N-086359 SNIP Environmental Assessment November 2014 3.1.2. Regulatory Framework ........................................................................ 3-2 3.1.3. Ambient Air Quality Standards and Pollutants of Concern ................ 3-2 3.2. Geology and Minerals ........................................................................................ 3-3 3.2.1. Environmental Setting ......................................................................... 3-3 3.2.2. Mineral Resources ............................................................................... 3-4 3.3. Soils .................................................................................................................... 3-5 3.4. Water Resources ................................................................................................. 3-5 3.4.1. Surface Water ...................................................................................... 3-5 3.4.2. Groundwater ........................................................................................ 3-6 3.5. Vegetation .......................................................................................................... 3-6 3.5.1. Environmental Setting ......................................................................... 3-6 3.5.2. Botanical Inventory Methods .............................................................. 3-9 3.5.3. Botanical Inventory Results ................................................................ 3-9 3.6. Invasive Species and Noxious Weeds .............................................................. 3-16 3.7. ESA-listed and Candidate Plant Species .......................................................... 3-16 3.8. Wildlife ............................................................................................................. 3-17 3.8.1. Mammals ........................................................................................... 3-19 3.8.2. Birds .................................................................................................. 3-20 3.8.3. Reptiles and Amphibians ................................................................... 3-22 3.9. Threatened, Endangered, Proposed, or Candidate Wildlife Species ................ 3-22 3.9.1. Inventory Methods for Threatened, Endangered, Proposed, or Candidate Wildlife Species ............................................................... 3-22 3.9.2. Inventory Results for Threatened, Endangered, Proposed, or Candidate Wildlife Species ............................................................... 3-23 3.10. Cultural Resources ........................................................................................... 3-28 3.10.1. Introduction ....................................................................................... 3-28 3.10.2. Definition of the Area of Potential Effect ......................................... 3-29 3.10.3. Affected Environment ....................................................................... 3-29 3.11. Paleontological Resources ................................................................................ 3-32 3.12. Land Use, Recreation, and Access ................................................................... 3-34 3.12.1. Environmental Setting and Methodology .......................................... 3-34 3.12.2. Land Ownership and Jurisdiction ...................................................... 3-34 3.12.3. Special Management Areas ............................................................... 3-36 3.12.4. Existing Land Use ............................................................................. 3-37 3.12.5. Recreation .......................................................................................... 3-37 3.12.6. Planned and Future Land Use ........................................................... 3-38 3.13. Visual Resources .............................................................................................. 3-40 3.13.1. Environmental Setting ....................................................................... 3-40 3.13.2. Project-Level Inventory ..................................................................... 3-41 3.13.3. Planning-Level Inventory (BLM VRI) .............................................. 3-43 3.14. Socioeconomics ................................................................................................ 3-44 3.14.1. Demographics ...................................................................................