Alternative Sediment Remediation Authorities to CERCLA: Elizabeth River Demonstration Robert Engler Moffatt & Nichol), Mississippi, (USA) Eric Smith Maryland, (USA)

Alternative Sediment Remediation Permitting Authorities Full and Continuing Coordination with Federal, State, Local permitting and Review Agencies and the Elizabeth River Project at the Outset of Project. Full Commercial Navigation Requirements Must Be Maintained. Pre-operational Assessment o Clean Water Act – CWA (USACE Guidance/Review o VA DEQ, DCR, VIMS, DGIF, MRC Guidance/Review Dredging o USACE, Section 10, Rivers and Harbors Act (R&HA), Clean Water Act 404(b)1 Guidance, Manuals o VA DEQ CWA, Water Quality Certification o VA DCR Oversight o VIMS Review

Dredge Material Rehandling/Treatment/Disposal o VA Authorized Land Fill Rules; Land Farming/Solidification and stabilization o TSCA – VA Rules Capping/Wetlands Restoration, Oyster Habitat o USACE, Section 10 R&HA, CWA 404(b)1 Guidance, Manuals o VA DEQ, CWA – Water Quality Certification o VA – DCR, DGIF, MRC Oversight o VIMS Review Source Control/Air Quality o VA Regulations USEPA Guidance and Oversight as Appropriate Under CWA Threatened and Endangered Species Coordination – VA DNR, USNMFS, USF&WS Essential Fish Habitat – VA DNR, USWMFS, USF&WS

Landscape Approach Forested Upland Wetlands Restoration Oyster Reef Creation Sediment Cleanup

Republic ERM CLEANUP GOALS

Remediation Methods  Natural Recovery  Removal of Sediments (Dredging)  Isolation and Containment of Sediments (Capping)  Combination of Above

Dredged Material Management 1.Mechanical Dredging 2.Transport to Weanack Plantation (or other site) 3.Landfarming 4.Dewatering/Stabilization to Landfill (e.g. Charles City County) 5.Placement at Other Approved Upland Site

Cap Engineering Development  Chemical Isolation Modeling  Follow US EPA Design Guidance  Isolation of Contaminants to ERM or Less  100-Year Plus Design Life  Cap Stability Assessment  Tidal and Storm Currents  Ship Induced Currents  Propwash

Cap Requirements Cap thicknesses for erosion protection and chemical isolation Focus for health benchmarks

Isolation Cap Modeling  Used two models (both in EPA guidance)  RECOVERY (v 4.3) model for design  Lampert & Reible model (LRM) for confirmation and additional tests  RECOVERY  USACE developed and validated model, 20 years of use with continual updating  Numerical, time-varying, mass balance  LRM  Analytical, steady-state, mass balance

Cap Isolation Conclusion/Recommendation  12 inch sand cap is protective given the expected low groundwater upwelling rates  The 12 inch protective cap on top of isolation adds extra protection

Cap Stability Assessment  Tidal and Storm Currents  Hydrodynamic Model of Tides and Storm Surge  Ship-Induced Currents  Numerical Model of Passing Ship  Propwash  Analytical Calculation of Prop Scour from Tugs

Hydrodynamic Model Domain MIKE FM Model Increased Resolution in Project Area 25-YEAR HURRICANE VALIDATED

Passing Vessel Model  Model DELPASS developed by Pinkster Marine Hydrodynamics  Panel model based on 3-d potential flow  Panels represent river bathymetry and vessel  Output 3 time-dependent velocity components on grid points of the river bottom  Grid points match MIKE3 model resolution

Alternative 1 Dredge + Cap Dredge 2’ Cap 2’ 2’ Sand Cap / Wetlands Dredge 2’ w/ Armored Cap Dredge to El -39’ w/ Armored Cap Armored Cap Dredge 2’ Cap 2’ 2’ Sand Cap Armored Cap Dredge to El -42 ’ Dredge Volume 172,460 cy