1. A Combined Solution for Sediment Remediation and Waterfront Development A Combined Solution for Sediment Remediation and Waterfront Development John T. Finn, P.E. GEI Consultants, Inc.. Dredging 2012

2. The Problem Dredging 2012

3. Removal of Sheen-Producing Sediments Protection of Existing Bulkheads Capping of Remaining Sediments On-site Solidification of Dredged Sediments Preparation for Waterfront Redevelopment A Complex Problem: A Combined Solution : John Finn, GEI Dredging 2012

4. Location: A Slip in New Bedford Harbor

5. Manufactured Gas and Tar Plant 1880 - 1960 OUTER SLIP INNER SLIP Dredging 2012

6. Outer Slip : - Remove all sheen-producing sediment in top foot - No off-site disposal: Place all dredged sediment in Inner Slip - 2-foot Composite Cap Inner Slip - Solidify dredged sediment and existing sediment/soil to bedrock - Prepare the site for waterfront redevelopment Minimum Remedy Requirements Dredging 2012

7. Remediation – Plan View Cell 2 Cell 1 Capping Area Fixed Turbidity Curtain Dredged Areas for Tar Removal Dredged Area for Cap Installation ISS Mixing Plant Water Treatment Facility Sheet Pile Walls Inner Slip ISS & Fill Area

8. Protection of bulkhead stability Final elevation allows sufficient draft for boat traffic Limited capacity of Inner Slip: - Account for expansion upon solidification - Account for expansion/settling upon dredging/placement Dredging Requirements and Constraints Dredging 2012

9. Dredging Behind Dual Curtains & Booms Dredging 2012

10. Dredging of Outer Slip

11. Vapor & Odor Suppression Foam Dredging 2012

12. GPS Positioning of Dredge Bites

13. Capping of Remaining Sediments Benthic Sand – 12 inches Stone Armor – 3 inches Gravel – 3 inches AquaBlok – 6 inches Sand Fill – thickness varies

14. AquaBlok Dredging 2012

15. Cap Placement Dredging 2012

16. Solidification: Inner Slip – Section View Cell 2 Cell 1 Existing Bulkhead Top of Bedrock (El. -24.2) New Sheet Pile Closure Walls Top of Dredge Spoils Top of Sediments Mean High Water Mean Low Water Top of Dredge Spoils Top of Bedrock (El. -39.0) Water Treatment Facility

17. Soil Mixing to Solidify Sediments

18. 1,350 cubic yards dredged 18,000 ft 2 dredge area 190 - eight foot diameter ISS columns 37 - three foot diameter ISS columns 7,000 - cubic yards of sediment and soil mixed 427 ton of AquaBlok Dredging, Capping, and ISS Statistics

19. Site Ready for Waterfront Development Dredging 2012

20. Questions? Thank You Dredging 2012

21. Environmental Business Council’s 2012 Award for Collaboration Study of In-Situ Solidification of Contaminated Sediments, Sponsored by the Electric Power Research Institute (EPRI) Post-Scripts Dredging 2012

22. MassDEP leadership streamlined complex permitting –Reached out to federal, state & local regulators –Coordinated multi-agency team approach –Hosted & facilitated 2 critical multi-agency meetings Public engagement –Public notice soliciting public comments on 10/23/2010 –Public meeting on 12/8/2010 with USEPA and MassDEP Innovative MCP site closure strategy Coordinating Multiple Agencies

23. MassDEP –Release Abatement Measure Plan –401 Water Quality Certification –Chapter 91 License EPA – TSCA 61C –Risk-Based Cleanup Plan U.S. Army Corps of Engineers, New England District –Category 2 General Permit New Bedford Conservation Commission - Wetland Order Of Conditions Property Owner Agreement: Fueling Terminal Ops Permitting and Legal Framework Dredging 2012

24. Dredge Cut Lines Min. Max. El -14. El -15. Min. Max. El -14.5 El -14. Tolerance Near BulkheadsTolerance In All Other Areas Dredging 2012