Contaminated sediment management in the U.S.

Transcription

1 Contaminated sediment management in the U.S. Rebecca Gardner Anchor QEA, USA and Norway company logo comes here

2 Contents Brief overview of beneficial use activities in the United States (U.S.) Relating contaminated sediment cleanup in the U.S. to managing contaminated dredged material Case studies

3 U.S. beneficial use overview Changes in environmental regulations continue to reduce volume suitable for open-water disposal In many regions, disposal costs increased by 10x 1992 U.S. regulation (Water Resources Development Act, or WRDA) set aside funding for benficial use demonstration projects Several habitat restoration projects were constructed using dredged material Supplemental funding provided by local ports Multiple agencies initiated sediment decontamination/ treatment technology demonstrations

4 Common beneficial use options Habitat restoration and development Beach nourishment Parks and other community use areas Mine reclamation and landfill capping/closure Commercial or industrial development/ brownfield redevelopment Multi-purpose activities combining two or more of the above options

5 Contaminated sediment cleanup in U.S. Cleanups are driven by state and U.S. EPA environmental regulations (most commonly under Superfund ) The requirement is to protect human health and the environment through risk reduction and comply with other related laws Seven other criteria used to evaluate cleanup options

6 Cleanup experience applied to dredged material management Technology transfer Contaminant migration and coastal/hydrodynamic modeling for capping and confined disposal (CAD/CDF) design Contaminant treatment and stabilization studies Importance of source control Importance of understanding risk and developing conceptual site models Use of multi-criteria decision analysis tools Increasing development of integrated projects

7 Treatment technologies near commercial scale Rotary kiln thermal treatment light-weight aggregate (LWA) Cement-Lock technology Ecomelt (cement) Minergy glass furnace technology glass aggregate BioGenesis SM sediment washing technology manufactured soil Solidification/stabilization construction fill

8 Technical Understanding Components risk in various environments

9 Integrated solutions Combine methods to reduce risk Sediment isolation and treatment Evaluate potential conflicts between methods to reduce risk, restore habitat, enable redevelopment, and/or support community activities Conceptual isolation/habitat restoration design: Contaminated Sediment

10 Integrated design Slope Bulkhead

11 Case Studies Poplar Island, Chesapeake Bay, Maryland USA habitat restoration Harbor Cleanup Project, Mosjøen, Norway land and port expansion Seattle Olympic Sculpture Park, Washington USA brownfield cleanup, restoration, community benefits

12 Case Study: Poplar Island Restoration of an historical island (more than 688 ha) back to its 1800 footprint Approximately 52 million cubic meters capacity over a 28-year time span Approximately half of the site footprint will receive thin lifts of dredged material, with the aim to convert them into future wetlands A variety of habitats, from tidal flats to bird islands and high marsh to low marshes, are planned

13 Poplar Island restoration plan Greater than m of earthen dikes built with mechanically and hydraulically placed dredged material More sheltered eastern side will receive wetland habitat plantings Once complete, 297 ha of wetlands, 340 ha of uplands, and 57 ha of open water embayment will be created

14 Testing the concept High Marsh Channel Width 35 feet Low Marsh Low Marsh Moat (-5 feet, 50 feet wide) Channel Width 15 feet Low Marsh Habitat Island Mud Flat Low Marsh High Marsh Channels (-3 ft Depth typ.) 100 ft Width

15 Pre-design testing, fill placement monitoring and adaptive management Fine-grained silts and clays Dredging, transport, and placement One cubic yard dredged is not one cubic yard placed Bulking and shrinkage testing Sediment sampling Bathymetric surveys Vegetation surveys Verification of PSDDF settlement estimates and hydrodynamic modeling

16 Poplar Island recent progress Google maps image

17 Case Study: Mosjøen, Norway Facility constructed in 1958 Property is adjacent to town and municipal port Two operating harbors both crucial to plant operations and local economy Evaluating synergistic alternatives to expand port and dispose of sediment

18 Benefits to local port Expansion space within congested existing facilities

19 Cleanup project elements Cleanup is required to address historical discharges Dredging and capping of PAH-impacted sediment 25,000 to 30,000 m 3 of dredged material Disposal options considered Existing inland landfill Non-adjacent confined disposal facilities (CDF) CDFs adjacent to private and municipal harbors

20 Disposal area options

21 Disposal area configuration

22 Disposal area technologies

23 Inspiration Case Study: Seattle Olympic Sculpture Park Fuel storage and transfer facility constructed in early 1900s, operating until 1975 Seattle Art Museum (SAM) purchased site in 2000 Company addressed major environmental cleanup issues State provided grants to assist SAM with continued cleanup and redevelopment of publicly-owned site Eagle by Alexander Calder Eagle by Alexander Calder

24 Site transformation

25 Shoreline restoration / renewed public access

26 What s the inspiration? With multiple stakeholder input and out of the box thinking, could you develop a project that includes? Management of port s dredged material Brownfield cleanup and economic benefits through land value increases Civic developments and community benefits Restoration of nature and improved ecosystem functions and coastal resilience Opportunities for education

27 Summary Much progress to promote beneficial use has been made, but we are still working on it Think beyond the dredging project Engage stakeholders early and often Begin with a focus on sediments as a potential resource, not just a waste and supporting policy must be in place Experience from contaminated sediment cleanups is transferable Integrate restoration and development goals into the cleanup action plan as early as possible

28 Thank you. Questions?