Alternative Sediment Remediation Authorities to CERCLA ... · Alternative Sediment Remediation...

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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)

Transcript of Alternative Sediment Remediation Authorities to CERCLA ... · Alternative Sediment Remediation...

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)

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

oClean Water Act – CWA (USACE Guidance/Review

oVA DEQ, DCR, VIMS, DGIF, MRC Guidance/Review

•Dredging

oUSACE, Section 10, Rivers and Harbors Act (R&HA),

Clean Water Act 404(b)1 Guidance, Manuals

oVA DEQ CWA, Water Quality Certification

oVA DCR Oversight

oVIMS Review

• Dredge Material Rehandling/Treatment/Disposal

oVA Authorized Land Fill Rules; Land Farming/Solidification and

stabilization

oTSCA – VA Rules

• Capping/Wetlands Restoration, Oyster Habitat

oUSACE, Section 10 R&HA, CWA 404(b)1 Guidance, Manuals

oVA DEQ, CWA – Water Quality Certification

oVA – DCR, DGIF, MRC Oversight

oVIMS Review

• Source Control/Air Quality

oVA 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 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

Tug Propeller Wash

Propeller Wash for Max and Typical Tugs

5100 HP Z-drive Twin Screw

1700 HP Twin Open Screw

22.22

max),(

x

r

x eurxu Velocity with axial distance (x)

and radial distance (y)

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

Alternative 2 Optimal Dredge + Cap

Cap 2’

2’ Sand Cap / Wetlands

Armored Cap

Dredge to El -39’

w/ Armored Cap

Armored Cap

Dredge 2’

Cap 2’

2’ Sand Cap

/ Wetlands

Armored Cap

Dredge to

El -42’

Dredge Volume 79,500 cy

Alternative 3 – Dredge All

Contaminated Volume

Dredge 8-10’

Armored Cap

Dredge Volume 520,950 cy

Alternative 4 No Dredging + Cap

Cap 2’

2’ Sand Cap / Wetlands

2’ Sand Cap

/ Wetlands Dredge to El -42’ 2’ Armored Cap

Dredge Volume 0 cy

Republic Cost Estimate

Unit Cost Alt 1 Alt 2 Alt 3 Alt 4

Dredging/Disposal $135-

$188/cy

$17.1M $7.9M $54.3M -

Sand Cap $70/cy $7.5M $7.5M $0.1M $7.5M

Rock Cap $112/cy $3.3M $3.3M $0.9M $3.3M

Rock Breakwater $125/ton $0.9M $0.9M - $0.9M

Mobilization 10% $2.8M $2.0M $5.5M $1.2M

Contingency 20% $5.6M $3.9M $11.1M $2.4M

Total $36.3M $25.5M $71.9M $15.3M

Alternative 2 Selected

Upland Sources

Coordinated by Other Agencies

McLean – Entered Volunteer Clean Up

Allied – EPA in Discussions with Owners

Shotmeyer and Southern Aggregates – No Known Upland

Source

Institutional Controls to Prevent

Recontamination

Recommended Controls for Future Activities

Landside Shoreline Construction Control

In-Water Construction Controls

Control Navigation Dredging in Mitigation Areas