TRANSCONTINENTAL GAS PIPE LINE COMPANY, LLC APPENDIX F – HYDRODYNAMIC AND SEDIMENT TRANSPORT MODELING RESULTS – BASE CASE SIMULATIONS, ADDENDUM 1, ADDENDUM 2, ADDENDUM 3, AND CONTAMINANT TRANSPORT MODELING RESULTS NORTHEAST SUPPLY ENHANCEMENT PROJECT January 2020 This page intentionally left blank. TRANSCONTINENTAL GAS PIPE LINE COMPANY, LLC APPENDIX F-1 – HYDRODYNAMIC AND SEDIMENT TRANSPORT MODELING RESULTS – BASE CASE SIMULATIONS NORTHEAST SUPPLY ENHANCEMENT PROJECT This page intentionally left blank. Northeast Supply Enhancement Project: Hydrodynamic and Sediment Transport Modeling Results – Base Case Simulations Prepared for: Ecology & Environment, Inc. 368 Pleasant View Drive Lancaster, NY 14086 On behalf of: Transcontinential Gas Pipe Line Company, LLC. 2800 Post Oak Blvd. Houston, TX 77056 Submitted By: RPS Date Submitted: 28 August 2017 Project POC: Nathan Vinhateiro, Ph.D. 55 Village Square Drive, South Kingstown, RI 02879 P: 401.789.6224; E: [email protected] rpsgroup.com NESE Hydrodynamic & Sediment Transport Modeling | August 28, 2017 Table of Contents Table of Contents .............................................................................................................................ii List of Figures .................................................................................................................................. iv List of Tables .................................................................................................................................... x Introduction .............................................................................................................................. 1 1.1 Project Background ......................................................................................................................... 1 1.2 Study Area Description .................................................................................................................... 2 1.3 Objectives and Tasks ....................................................................................................................... 3 Hydrodynamic Modeling .......................................................................................................... 4 2.1 WQMAP BFHYDRO Description ....................................................................................................... 4 2.1.1 Model Theory ........................................................................................................................... 5 2.1.2 Previous BFHYDRO Applications Within the New York/New Jersey Harbor Estuary ............... 7 2.2 BFHYDRO Application ...................................................................................................................... 7 2.2.1 Model Grid (Resolution/Bathymetry) ...................................................................................... 7 2.2.2 Boundary Conditions ................................................................................................................ 8 2.2.3 Set-up and Calibration ............................................................................................................ 11 2.2.4 BFHYDRO Results .................................................................................................................... 21 Suspended Sediment Modeling .............................................................................................. 26 3.1 SSFATE Description ........................................................................................................................ 26 3.1.1 Model Theory ......................................................................................................................... 26 3.1.2 Previous SSFATE Applications Within the New York/New Jersey Harbor Estuary ................. 29 3.2 SSFATE Application for the Northeast Supply Enhancement Project ........................................... 29 3.2.1 Description of SSFATE Model Set-up ...................................................................................... 30 3.2.1.1 Sediment Source Terms .................................................................................................. 33 3.2.1.2 Sediment Grain Size Distribution .................................................................................... 34 ii rpsgroup.com NESE Hydrodynamic & Sediment Transport Modeling | August 28, 2017 3.3 SSFATE Base Case Scenarios .......................................................................................................... 37 3.4 SSFATE Results for Base Case Scenarios ........................................................................................ 39 3.4.1 Scenario 1 – Morgan Shore Excavation Activities .................................................................. 40 3.4.2 Scenario 2 – Clamshell Trenching Between Morgan HDD and Midline Tie-in ....................... 45 3.4.3 Scenario 3 – Jetting at the Neptune Cable Crossing in Raritan Bay ....................................... 49 3.4.4 Scenario 4 – Jet Trenching Between Midline Tie-in and Raritan Channel Transition ............ 53 3.4.5 Scenario 5 – Jet Trenching Between Curve 1 and Anchorage Area ....................................... 57 3.4.6 Scenario 6 – Jet Trenching Between Curve 4 and Ambrose Channel ..................................... 61 3.4.7 Scenario 7 – Jet Trenching Between Ambrose Channel and Neptune Crossing 35 ............... 65 3.4.8 Scenario 8 – Clamshell Trenching Across the Raritan Channel .............................................. 69 3.4.9 Scenario 9 – Clamshell Trenching Between the Anchorage Area and Chapel Hill Channel ... 73 3.4.10 Scenario 10 – Excavation of Ambrose Channel HDD Exit Pit (West) .................................... 77 3.4.11 Scenario 11 – Excavation of Ambrose Channel HDD Entry Pit (East) and Tie-in .................. 81 3.4.12 Scenario 12 – Jetting at the Neptune Cable Crossing Offshore Rockaway .......................... 85 3.4.13 Scenario 13 – Clamshell Trenching Between the Neptune Crossing and RDL Manifold...... 89 3.4.14 Scenario 14 – Excavation the Tie-in Skid and Manifold at Rockaway .................................. 93 References .............................................................................................................................. 99 iii rpsgroup.com NESE Hydrodynamic & Sediment Transport Modeling | August 28, 2017 List of Figures Figure 1. Offshore study area for the proposed Raritan Bay Loop (from Williams/Transco). ...................... 2 Figure 2. Illustration of sigma grid representation. ...................................................................................... 5 Figure 3. BFHYDRO, boundary conforming grid and bathymetry for NY/NJ Harbor Estuary and the New York Bight. ..................................................................................................................................................... 9 Figure 4. BFHYDRO, boundary conforming grid showing river boundaries for the Raritan, Passaic, Hackensack and Hudson Rivers and open boundaries for the New York Bight and the connection between the NY/NJ Harbor Estuary and Long Island Sound, at Kings Point. .............................................. 10 Figure 5. Map of Raritan Bay showing the locations of the Rutgers ADCP mooring sites. The dates of each of the four mooring deployment periods is presented in the column to the left of the map. .......... 13 Figure 6. Time series of model-predicted versus observed tidal elevation for NOAA NOS Tide Station 8531680 at Sandy Hook, January 2012, lower plot. Upper plot shows the concurrent wind speed and direction at Sandy Hook, January 2012. The wind stick vectors on the wind plot show the wind speed as the length of the vector, and the direction as the direction towards which the wind is blowing. ............ 14 Figure 7. Map of the NOAA tide station locations in the Project area, for comparison of model-predicted and observed tidal elevation harmonic constituents. ................................................................................ 15 Figure 8. Comparison of model-predicted and observed M2 and K1 tidal elevation harmonic constituents, at various NOAA tide station in and around the NY/NJ Harbor Estuary area....................... 16 Figure 9. Model-predicted versus observed tidal currents at Rutgers ADCP mooring RB1, January 2012. The upper 2 plots show the model-predicted and observed E-W and N-S current vector components, respectively, at the surface. The 3rd and 4th plots show the model-predicted and observed E-W and N-S current vector components, respectively, at the bottom. The lower plot shows the concurrent wind speed and direction at Sandy Hook, January 2012. .................................................................................... 18 Figure 10. Model-predicted versus observed tidal currents at Rutgers ADCP mooring RB2, in the Raritan Bay West Reach Channel, January 2012. The upper 2 plots show the model-predicted and observed E-W and N-S current vector components, respectively, at the surface. The 3rd and 4th plots show the model- predicted and observed E-W and N-S current vector components, respectively, at the bottom. The lower plot shows the concurrent wind speed and direction at Sandy Hook, January 2012. ..................... 19 Figure 11. Example model-predicted maximum flood tide currents in the Raritan Bay study area, January 9th, 2012. The current vectors (red arrows) are plotted over color-coded current speed contours. ........ 20