ENVIRONMENTAL ASSESSMENT Air Quality Technical Report February, 2020 Table of Contents Executive Summary ..................................................................................................................6 1.0 Project Background ..................................................................................................... 11 1.1 Introduction ...........................................................................................................11 1.1.1 Project Termini .................................................................................................11 1.1.2 Study Area .......................................................................................................11 1.1.3 Purpose and Need ...........................................................................................12 1.2 Alternatives ...........................................................................................................12 1.2.1 No Build Alternative ..........................................................................................12 1.2.2 Build Alternative ...............................................................................................12 1.3 Project Status in the Regional Transportation Plan and Program ..........................14 1.4 Summary of Traffic Data and Forecasts ................................................................15 2.0 Regulatory Requirements and Guidance .................................................................... 18 2.1 National Environmental Policy Act of 1969 (NEPA) ...............................................18 2.1.1 FHWA Guidance for Implementing NEPA for Air Quality ..................................18 2.1.2 Programmatic Agreements ...............................................................................18 2.2 Transportation Conformity ....................................................................................19 2.2.1 Project-Inclusion in Regional Transportation Plans and Programs ....................20 2.2.2 FHWA Categorical Finding for Carbon Monoxide .............................................20 3.0 Ambient Air Quality ...................................................................................................... 21 3.1 National Ambient Air Quality Standards (NAAQS) ................................................21 3.2 Air Quality Attainment Status of Project Area ........................................................23 3.3 Air Quality Data and Trends ..................................................................................23 3.3.1 Carbon Monoxide (CO) ....................................................................................23 3.3.2 Other Criteria Pollutants ...................................................................................23 3.3.3 Mobile Source Air Toxics (MSATs) ...................................................................26 4.0 Project Assessment ..................................................................................................... 27 4.1 Application of the VDOT Resource Document .....................................................27 4.2 Carbon Monoxide Assessment ............................................................................27 4.2.1 Background ......................................................................................................27 4.2.2 Level of Analysis Determination........................................................................30 4.2.3 Worst-Case Modeling Overview .......................................................................30 4.2.4 Traffic Data and Forecasts for the CO Analysis ................................................31 4.2.5 Alternatives Modeled ........................................................................................34 4.2.6 Worst-Case Modeling Configuration .................................................................34 4.2.7 Emission Modeling ...........................................................................................36 4.2.8 Dispersion Modeling .........................................................................................40 4.2.9 Construction Emissions ....................................................................................47 4.2.10 Summary of Assumptions for the Worst-Case Analysis ....................................47 4.3 Mobile Source Air Toxics (MSATs) Assessment ..................................................48 4.3.1 Level of Analysis Determination........................................................................49 4.3.2 MSAT Analysis .................................................................................................49 4.4 Greenhouse Gases .............................................................................................60 4.5 Indirect Effects and Cumulative Impacts (IECI) Assessment ...............................61 5.0 Mitigation ......................................................................................................................62 6.0 Consultation ................................................................................................................. 62 6.1.1 Public Consultation ...........................................................................................62 6.1.2 Models, Methods, Assumptions and Protocols Specified in the VDOT Resource Document .........................................................................................................63 7.0 Conclusions .................................................................................................................. 63 Appendix A: Average Daily Traffic Mainline Forecasts and 2018 Intersection Baseline Volumes Appendix B: Scoping Framework Document for I-495 NEXT Project - FHWA Concurrence for Approach and Methodology Appendix C: I-495 NEXT Travel Demand Forecasting Framework Memorandum Appendix D: Results of 2025 and 2045 Intersection Operations Analysis Appendix E: I-495 NEXT Traffic Operations Analysis Framework Memorandum Appendix F: Sample MOVE Run Specification for MSAT Analysis Appendix G: Sample MOVE Run Specification for CO Analysis Appendix H: Sample CAL3i Input / Output Files Appendix I: Memorandum of the Proposed Air Quality Modeling and Analysis Approach for the VDOT I-495 Northern Extension Project (I-495 NEXT) List of Exhibits Exhibit 1.1.1: I-495 Express Lanes Northern Extension Project Limits .................................... 13 Exhibit 1.4.1: Project Study Area as per the Traffic Analysis ................................................... 16 Exhibit 1.4.2: Traffic Study Area ............................................................................................... 17 Exhibit 2.1.1: National Ambient Air Quality Standards (US EPA Tabulation) ........................ 22 Exhibit 3.3.1: Nationwide Long-Term Trend in Ambient CO Concentrations ......................... 24 Exhibit 3.3.2: Ambient Concentrations of Carbon Monoxide in Virginia ................................. 24 Exhibit 3.3.3: Trend in Ambient CO Concentrations ................................................................. 25 Exhibit 3.3.4: Trend for 1-hour Sulfur Dioxide (PPM) – Northern Region ............................... 25 Exhibit 3.3.5: Trend for 8-hour Ozone (PPM) – Northern Region ............................................ 26 Exhibit 4.2.1: Public Road Mileage, Lane-Miles and Vehicle Miles Traveled (VMT) ............. 28 Exhibit 4.2.2: Recent Trends in VMT and Related Statistics for Virginia ................................ 29 Exhibit 4.2.3: Federal Emission Standards for CO for New Automobiles and Light Trucks .... 30 Exhibit 4.2.4: Intersections Considered for CO Modeling ......................................................... 32 Exhibit 4.2.5: Study Intersections Considered for CO Modeling .............................................. 33 Exhibit 4.2.6: PM Peak Hour Volumes, Delay, and Level of Service (LOS) at Intersections .. 35 Exhibit 4.2.7: Comparison of Project Forecasts for Peak Hour Traffic Volumes and VDOT Resource Document Worst-Case Volumes as Applied for the CO Worst-Case Analysis ............................................................................................................... 36 Exhibit 4.2.8: MOVES Source Types and HPMS Vehicle Types ............................................. 37 Exhibit 4.2.9: Road Type Mapping ............................................................................................ 37 Exhibit 4.2.10 (a): MOVES Input Summary for CO – Main Screen ............................................ 38 Exhibit 4.2.10 (b): MOVES Input Summary for CO – Project Data Manager ............................. 39 Exhibit 4.2.11: MOVES Fleet Average Worst-Case CO Emission Factors Summary ................ 40 Exhibit 4.2.12: CAL3QHC Worst-Case Analysis Inputs ............................................................. 42 Exhibit 4.2.13 (a): CO Dispersion Modeling Worst-Case Configuration & Receptor Locations – Route 123 & Tysons Boulevard .................................................................... 43 Exhibit 4.2.13 (b): CO Dispersion Modeling Worst-Case Configuration & Receptor Locations – Route 123 & Capital One Tower Drive/ Old Meadow Road ........................ 44 Exhibit 4.2.13 (c): CO Dispersion Modeling Worst-Case Configuration & Receptor Locations – Route 123 & Scotts Crossing Boulevard/ Colshire Drive ............................. 45 Exhibit 4.2.13 (d): CO Dispersion Modeling Worst-Case Configuration & Receptor Locations