Alternative Sediment Remediation Authorities to CERCLA: Elizabeth River Demonstration Robert Engler ([email protected]) Moffatt & Nichol), Vicksburg, Mississippi, (USA) Eric Smith ([email protected]), Baltimore, Maryland, (USA)
Jan 05, 2016
Alternative Sediment Remediation Authorities to CERCLA: Elizabeth River
DemonstrationRobert Engler ([email protected]) Moffatt &
Nichol), Vicksburg, Mississippi, (USA)
Eric Smith ([email protected]), Baltimore, 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 Assessmento Clean Water Act – CWA (USACE Guidance/Reviewo VA DEQ, DCR, VIMS, DGIF, MRC Guidance/Review
• Dredgingo USACE, Section 10, Rivers and Harbors Act (R&HA),
Clean Water Act 404(b)1 Guidance, Manualso VA DEQ CWA, Water Quality Certificationo VA DCR Oversighto VIMS Review
• Dredge Material Rehandling/Treatment/Disposalo VA Authorized Land Fill Rules; Land Farming/Solidification and
stabilizationo TSCA – VA Rules
• Capping/Wetlands Restoration, Oyster Habitato USACE, Section 10 R&HA, CWA 404(b)1 Guidance, Manualso VA DEQ, CWA – Water Quality Certificationo VA – DCR, DGIF, MRC Oversighto VIMS Review
• Source Control/Air Qualityo 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
Mixed Bioturbation Mixed Bioturbation LayerLayer
Sediment –Water Interface
Clean Sediments
Contaminated Sediments
Isolation Cap
Protection Cap
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 ModelIncreased 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