CAPE COD CANAL HIGHWAY BRIDGES PHASE 1 - MAJOR REHABILITATION EVALUATION REPORT AND ENVIRONMENTAL ASSESSMENT BOURNE, MASSACHUSETTS October 2019 Prepared by: New England District U.S. Army Corps of Engineers 696 Virginia Road Concord, Massachusetts 01742 This Page Intentionally Left Blank Contents Contents .......................................................................................................................................... ii 1.0 INTRODUCTION ............................................................................................................... 1 1.1 Background ...................................................................................................................... 1 2.0 AUTHORIZATION AND REGULATORY HISTORY..................................................... 1 2.1 Congressional Authorizations .......................................................................................... 1 2.2 National Environmental Policy Act (NEPA) Compliance ............................................... 2 3.0 PROJECT SCOPE AND STUDY AREA ........................................................................... 2 3.1 Scope ................................................................................................................................ 2 3.2 Location and Description ................................................................................................. 3 3.3 Study Area ........................................................................................................................ 4 4.0 PURPOSE AND NEED ....................................................................................................... 5 4.1 Purpose ............................................................................................................................. 5 4.2 Need ................................................................................................................................. 5 5.0 ALTERNATIVES ANALYSIS ........................................................................................... 5 5.1 Alternatives Considered but Not Carried Forward .......................................................... 6 5.1.1 Replacement of Both Bridges with a Single Bridge ................................................. 6 5.1.2 Construction of a New Third Highway Bridge ......................................................... 6 5.1.3 Replacement of One or Both Highway Bridges with Tunnels or a Single Tunnel ... 6 5.1.4 Replacement of One or Both Bridges with Low Level Draw Spans or Low Level Causeways ............................................................................................................................... 7 5.1.5 Deauthorization and Closure of the Canal ................................................................ 8 5.2 Alternatives Evaluated ..................................................................................................... 8 5.2.1 Alternative A - No Action (Without Project Condition) .......................................... 9 5.2.2 Alternative B - Major Rehabilitation for Both Bridges ............................................ 9 5.2.3 Alternative C - Replacement of Both Highway Bridges with New Bridges – 4 Lanes ................................................................................................................................. 10 5.2.4 Alternative D (Preferred Alternative) - Replacement of Both Highway Bridges with New Bridges – 4 Lanes and 2 Auxiliary Lanes ..................................................................... 11 6.0 AFFECTED ENVIRONMENT and ENVIRONMENTAL CONSEQUENCES .............. 11 6.1 Physical Resources ......................................................................................................... 11 Cape Cod Canal Highway Bridges, MA Draft Environmental Assessment Major Rehabilitation Evaluation Report EA - i October 2019 6.1.1 Land Use ................................................................................................................. 11 6.1.2 Terrain and Topography ......................................................................................... 14 6.1.3 Geology/Soils .......................................................................................................... 14 6.1.4 Climate .................................................................................................................... 15 6.1.5 Sea Level Change ................................................................................................... 16 6.1.6 Air Quality .............................................................................................................. 17 6.2 Water Resources ............................................................................................................. 19 6.2.1 Surface Water and Wetlands ................................................................................... 19 6.2.2 Water Quality .......................................................................................................... 23 6.2.3 Groundwater ........................................................................................................... 24 6.2.4 Floodplains .............................................................................................................. 25 6.3 Coastal Resources .......................................................................................................... 26 6.3.1 Coastal Zones .......................................................................................................... 26 6.3.2 Coastal Barrier Resources System .......................................................................... 29 6.4 Biological Resources ...................................................................................................... 29 6.4.1 Vegetation ............................................................................................................... 29 6.4.2 Wildlife ................................................................................................................... 31 6.4.3 Fisheries and Marine Wildlife ................................................................................ 33 6.4.4 Threatened and Endangered Species ...................................................................... 36 6.5 Historic and Archaeological Resources ......................................................................... 42 6.6 Socioeconomics Resources ............................................................................................ 46 6.6.1 Demographics ......................................................................................................... 46 6.6.2 Community Economics ........................................................................................... 50 6.6.3 Land Use and Zoning .............................................................................................. 55 6.6.4 Recreation ............................................................................................................... 57 6.6.5 Public Utilities ........................................................................................................ 60 6.6.6 Public Health and Safety ......................................................................................... 61 6.6.7 Traffic ..................................................................................................................... 69 6.6.8 Environmental Justice ............................................................................................. 77 6.6.9 Hazardous Materials and Waste ................................................................................... 83 Cape Cod Canal Highway Bridges, MA Draft Environmental Assessment Major Rehabilitation Evaluation Report EA - ii October 2019 6.6.10 Noise ....................................................................................................................... 86 6.7 Summary of Effects ........................................................................................................ 90 7.0 INDIRECT EFFECTS AND CUMULATIVE IMPACTS ................................................ 95 7.1 Induced Development .................................................................................................... 96 7.1.1 Development Potential ............................................................................................ 96 7.1.2 Traffic modeling ..................................................................................................... 99 7.1.3 Population models and forecasted growth ............................................................ 101 7.2 Cumulative Impacts...................................................................................................... 103 7.2.1 Bourne Rotary Alternatives .................................................................................. 104 7.2.2 Bourne Rotary with Highway Interchange ........................................................... 106 7.2.3 Belmont Circle ...................................................................................................... 108 7.2.4 Route 6 Exit 1C Relocation .................................................................................. 109 7.2.5 Route 6 Additional Eastbound Travel Lane.......................................................... 111 7.2.6 Total Cumulative Impacts ..................................................................................... 112 7.3 Cumulative Significance: ............................................................................................