DOE/EA‐1759 Environmental Assessment Southwest Alaska Regional Geothermal Energy Project Naknek, Alaska May 2010 U.S. Department of Energy Golden Field Office 1617 Cole Boulevard Golden, Colorado 80401 Environmental Assessment Southwest Alaska Regional Geothermal Energy Project Naknek, Alaska Table of Contents Page ACRONYMS AND ABBREVIATIONS ..................................................................................................... v 1.0 INTRODUCTION ........................................................................................................................... 1 1.1 National Environmental Policy Act and Related Procedures ............................................. 1 1.2 Background ......................................................................................................................... 5 1.3 Scoping ............................................................................................................................... 5 1.3.1 Agency Consultation .............................................................................................. 6 1.4 Purpose and Need ............................................................................................................... 6 1.5 Organization of this EA ...................................................................................................... 6 2.0 PROPOSED ACTION AND ALTERNATIVES ............................................................................ 7 2.1 Proposed Action .................................................................................................................. 7 2.2 Overview ............................................................................................................................. 7 2.3 Project Location .................................................................................................................. 7 2.4 Existing Facilities ............................................................................................................... 7 2.5 Water Sources ................................................................................................................... 11 2.6 Infrastructure Improvements ............................................................................................. 11 2.7 Evaluation of Geothermal Resource for Commercial Power Production ......................... 15 2.7.1 Characterize the Existing Geothermal Resource ................................................. 15 2.7.2 Possible Enhancement of the Geothermal Resource............................................ 17 2.7.3 Determine Whether Enhanced Geothermal System Is Adequate for Commercial Power Production ............................................................................ 17 2.8 Operations ......................................................................................................................... 22 2.9 Decommissioning ............................................................................................................. 23 2.10 No Action Alternative ....................................................................................................... 23 2.11 Applicant Committed Measures ....................................................................................... 23 2.12 Reserve Tank and Waste Disposal .................................................................................... 23 2.13 Stormwater Collection ...................................................................................................... 23 2.14 Air Quality ........................................................................................................................ 24 2.15 Noise ................................................................................................................................. 24 2.16 Biological Resources ........................................................................................................ 24 2.17 Seismicity.......................................................................................................................... 25 3.0 AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES ....................... 25 3.1 Physical Environment ....................................................................................................... 25 3.1.1 Meteorology ......................................................................................................... 25 3.1.2 Air Quality ........................................................................................................... 26 3.1.3 Geology ................................................................................................................ 29 3.1.4 Soils ..................................................................................................................... 29 3.1.5 Seismicity ............................................................................................................ 30 3.2 Biological Resources ........................................................................................................ 31 3.2.1 Birds and Waterfowl ............................................................................................ 31 3.2.2 Terrestrial Mammals ............................................................................................ 35 3.2.3 Fisheries Resources .............................................................................................. 39 3.2.4 Threatened and Endangered Species ................................................................... 40 3.2.5 Vegetation and Wetlands ..................................................................................... 42 3.3 Water Resources ............................................................................................................... 42 3.3.1 Affected Environment .......................................................................................... 42 3.3.2 Environmental Consequences .............................................................................. 43 3.4 Cultural Resources ............................................................................................................ 43 3.4.1 Affected Environment .......................................................................................... 44 3.4.2 Environmental Consequences .............................................................................. 45 DOE/EA-1759 i May 2010 Rev. 2 Environmental Assessment Southwest Alaska Regional Geothermal Energy Project Naknek, Alaska 3.5 Land Use ........................................................................................................................... 45 3.5.1 Affected Environment .......................................................................................... 45 3.5.2 Environmental Consequences .............................................................................. 46 3.6 Noise ................................................................................................................................. 46 3.6.1 Affected Environment .......................................................................................... 46 3.6.2 Environmental Consequences .............................................................................. 46 3.7 Infrastructure ..................................................................................................................... 49 3.7.1 Affected Environment .......................................................................................... 49 3.7.2 Environmental Consequences .............................................................................. 50 3.8 Aesthetics .......................................................................................................................... 50 3.8.1 Affected Environment .......................................................................................... 50 3.8.2 Environmental Consequences .............................................................................. 50 3.9 Socioeconomics ................................................................................................................ 51 3.9.1 Community Profiles ............................................................................................. 51 3.9.2 Subsistence .......................................................................................................... 53 3.9.3 Environmental Justice .......................................................................................... 54 3.9.4 Environmental Consequences .............................................................................. 55 3.10 Intentional Destructive Acts ............................................................................................. 55 4.0 CUMULATIVE EFFECTS ........................................................................................................... 55 4.1 Evaluation and Summary .................................................................................................. 55 4.2 Meteorology and Air Quality ............................................................................................ 56 4.3 Geology, Soils, and Seismicity ......................................................................................... 56 4.4 Biological Resources ........................................................................................................ 57 4.4.1 Birds and Waterfowl ...........................................................................................