I-66-ITB-Widening-EA_Cover_ALL.pdf 5 11/4/16 10:33 AM Indirect Effects and Cumulative Impacts November 2016 Prepared in support of the Environmental Assessment for Transform Interstate 66: Inside the Capital Beltway, Eastbound Widening State Project Number: 0066-96A-417, P101, R201, C501; UPC: 108424 Federal Project Number: NHPP-066-1(356) From: Exit 67 (Route 267) Dulles Connector Road To: Exit 71 (Route 237) Fairfax Drive Fairfax and Arlington Counties, Virginia Table of Contents 1. INTRODUCTION ................................................................................................................................ 1 1.1 HISTORY OF I-66 ....................................................................................................................... 1 1.2 PROJECT HISTORY ................................................................................................................... 2 1.3 ALTERNATIVES CARRIED FORWARD FOR DETAILED STUDY ..................................... 3 1.3.1 No Build Alternative ............................................................................................................. 3 1.3.2 Build Alternative ................................................................................................................... 4 2. METHODOLOGY ............................................................................................................................... 5 2.1.1 Regulatory Context ............................................................................................................... 5 2.1.2 Indirect Effects ...................................................................................................................... 6 2.1.3 Cumulative Impacts .............................................................................................................. 9 3. INDIRECT EFFECT ANALYSIS ...................................................................................................... 10 3.1 STEP 1: SCOPING ..................................................................................................................... 10 3.2 STEP 2: IDENTIFY STUDY AREA DIRECTION AND GOALS ........................................... 11 3.2.1 Study Areas ......................................................................................................................... 11 3.2.2 Directions and Goals ........................................................................................................... 17 3.3 STEP 3: INVENTORY OF SENSITIVE RESOURCES IN THE STUDY AREA ................... 35 3.3.1 Socioeconomic Resources ................................................................................................... 35 3.3.2 Natural Resources ............................................................................................................... 37 3.3.3 Historic Resources .............................................................................................................. 61 3.4 STEP 4: IDENTIFY IMPACT CAUSING ACTIVITIES OF THE BUILD ALTERNATIVES 61 3.5 STEP 5: IDENTIFY INDIRECT EFFECTS FOR ANALYSIS ................................................. 62 3.6 STEP 6: ANALYZE INDIRECT EFFECTS AND EVALUATE ANALYSIS RESULTS ....... 63 3.6.1 No Build Alternative ........................................................................................................... 63 3.6.2 Build Alternative ................................................................................................................. 64 3.7 STEP 7: ASSESS CONSEQUENCES AND DEVELOP MITIGATION .................................. 73 3.7.1 No Build Alternative ........................................................................................................... 73 3.7.2 Build Alternative ................................................................................................................. 73 4. CUMULATIVE IMPACTS ................................................................................................................ 77 4.1 STUDY AREA AND GEOGRAPHIC SCOPE .......................................................................... 77 4.2 WHAT ARE THE TEMPORAL BOUNDARIES FOR THE STUDY? .................................... 77 4.3 WHAT ARE THE RESOURCES AFFECTED BY THE STUDY? .......................................... 77 Transform I-66 November 2016 i Indirect Effects and Cumulative Impacts Technical Report 4.4 WHAT ARE OTHER PAST, PRESENT, AND REASONABLY FORESEEABLE ACTIONS THAT HAVE IMPACTED OR MAY IMPACT THESE RESOURCES? ............................................ 77 4.4.1 Past Actions ........................................................................................................................ 77 4.4.2 Present and Reasonably Foreseeable Future Actions .......................................................... 80 4.5 WHAT WERE THOSE IMPACTS? .......................................................................................... 82 4.5.1 Socioeconomic Resources and Land Use ........................................................................... 82 4.5.2 Natural Resources ............................................................................................................... 85 4.5.3 Historic Resources .............................................................................................................. 88 4.5.4 Summary of Cumulative Impacts ....................................................................................... 89 4.6 WHAT IS THE OVERALL IMPACT ON THESE VARIOUS RESOURCES FROM THE ACCUMULATION OF THE ACTIONS? ............................................................................................. 89 5. REFERENCES ................................................................................................................................... 90 LIST OF TABLES Table 2-1: Socioeconomic Resources I & C Study Area Current Land Use ............................................. 35 Table 2-2: Restricted Uses of Assessed Waters in the Natural Resources Indirect Effects and Cumulative Impacts Study Area ..................................................................................................................................... 41 Table 2-3: Established TMDLs for Impaired Waters in the Natural Resources Indirect Effects and Cumulative Impacts Study Area ................................................................................................................. 43 Table 2-4: Land Cover in the Natural Resources Indirect Effects and Cumulative Impacts Study Area .. 47 Table 2-5: Potential or Confirmed Threatened or Endangered Species in the Natural Resources Indirect Effects and Cumulative Impacts Study Area .............................................................................................. 59 Table 2-6: Direct Impacts of the Alternatives ............................................................................................ 61 Table 2-7: Build Alternative Induced Growth Study Area Outside Designated Growth Areas ................ 67 Table 2-8: Wetlands, Streams, and Floodplains in the Build Alternative’s Induced Growth Study Area .... 72 Table 3-1: General Effects Determination Matrix ..................................................................................... 82 Table 3-2: Summary of Build Alternative Incremental Contribution to Cumulative Impacts ................... 89 LIST OF FIGURES Figure 1-1: Direct vs. Indirect Environmental Impact ................................................................................. 5 Figure 1-2: Cumulative Impacts .................................................................................................................. 7 Figure 1-3: Highway Investment on Typical Progress of Urbanization ...................................................... 8 Figure 2-1: Induced Growth Study Area .................................................................................................... 13 Figure 2-2: Socioeconomic Resources Indirect Effects and Cumulative Impacts Study Area .................. 14 Figure 2-3: Natural Resources Indirect Effects and Cumulative Impacts Study Area ............................... 15 Figure 2-4: Historic Resources Indirect Effects and Cumulative Impacts Study Area .............................. 16 Figure 2-5: Study Area, Fairfax County, and Arlington County Employment Projections ....................... 21 Figure 2-6: Fairfax County, Arlington County, and Virginia Unemployment Rates ................................ 22 Figure 2-7: Socioeconomic Resources I & C Study Area Current Land Use ............................................ 36 Figure 2-8: Socioeconomic Resources I & C Study Area Environmental Justice Block Groups .............. 38 November 2016 Transform I-66 ii Indirect Effects and Cumulative Impacts Technical Report Figure 2-9: Impaired Waterways in the Natural Resources Indirect Effects and Cumulative Impacts Study Area ............................................................................................................................................................. 39 Figure 2-10: 100-Year Floodplains in the Natural Resources Indirect Effects and Cumulative Impacts Study Area .................................................................................................................................................. 45 Figure 2-11: 500-Year Floodplains in the Natural Resources Indirect Effects and Cumulative Impacts Study Area .................................................................................................................................................