Sediment Cleanup Options
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Transcript Sediment Cleanup Options
Sediment Cleanup Options
Choosing Among Options
• Regulatory framework for descisions (Materials
courtesy of Portland Office, ACOE)
•CDF Example: Ross Island (Materials courtesy of
Stuart Albright, Hart Crowser)
• Wyckoff/Eagle Harbor (Puget Sound)
7/16/2015
W. Fish, Portland State University
Copyright, 1996 © Dale Carnegie & Associates, Inc.
Quantities of Dredged
Sediments
250 million cubic yards from
25,000 miles of navigation channels
75 million cubic yards from permits
325 million cubic yards each year
How Much Dredged Material?
> 5½ feet deep over
Washington, D.C.
> 1½ feet deep
over Chicago
Authorization
Rivers and Harbors Act of 1899,
Section 10
Clean Water Act
Section 404
Marine Protection, Research, and
Sanctuaries Act
Section 103
Regulatory Authorities
U.S. National Marine Fisheries Service
U.S. Fish and Wildlife Service
U.S. Environmental Protection Agency
State Fish and Game Agencies
State Water Quality Certifying Agencies
State Coastal Zone Management Agencies
Other Federal and State Agencies
Federal Standard
The disposal alternative or alternatives
identified by the Corps which represents the
least costly alternative consistent with sound
engineering practices and meeting the
environmental standards established by the
404(b)(1) evaluation process or ocean
dumping criteria.
Framework for Environmental
Acceptability of Dredged Material
Disposal Alternatives
Evaluation of Dredging Project Requirements
Identification of Alternatives
Initial Screening of Alternatives
Detailed Assessment of Alternatives
Alternative Selection
Technical Framework
Summary
Reflects real-world conditions
Reflects aquatic, intertidal, and upland
environments
Indicates biological availability of
contaminants
Predicts potential environmental impacts
Provides appropriate level of protection
Is consistent with CWA, MPRSA, and NEPA
TIER I
• Existing
Data
TIER II
• Physical/Chem. data
• Screening Tests
•Predictive models
TIER III
• Toxicity Tests
• Bioaccumulation Tests
TIER IV
• Chronic Sublethal Tests
• Steady-State Bioaccumulation Tests
• Risk Assessment
https://www.nwp.usace.army.mil/ec/h/hr/
Basic Dredge Types
Hydraulic
Pipeline
Hopper
Mechanical
Clamshell
Other / Combinations
Factors in Selection of
Dredging Equipment
Physical characteristics of sediments
Quantities to be dredged
Dredging depth
Distance to disposal area
Physical environment of and between
areas
Contamination level of sediments
Method of disposal
Dredged Material Disposal
Alternatives
Open Water Placement
Ocean ~ Estuarine ~ Lakes ~ Rivers
Confined Disposal Facilities (CDFs)
Diked containment
Beneficial Use Applications
Beneficial Use (BU)
Applications
BU is alternative of first choice
Needs and Opportunities
Material Suitability
Logistical Constraints
Regulatory Requirements Vary
CWA / MPRSA
Other
Confined Disposal
Facilities
Site characterization / selection
Engineering design
Operational considerations
Contaminant pathways and controls
Long-term management
Monitoring
Confined Disposal Alternatives
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Engineering Issues
Reduce Contaminant Pathways
Disposal pathways
Physical disturbance
Seepage
Optimize Capacity
Physical Disturbance
Erosion and Scour
Slope Stability
Nature of underlying materials
Stability of existing and future slopes
Excavation and Removal
Intended End Use of Site
Consolidation and Settlement
Cap Properties
Seepage
Excess Pore Water
Long Term Seepage
Other Considerations
Dredged disposal volume
Area of land desired
Habitat mitigation requirements
Cost comparisons
Ross Island
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Typical Cross Section
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Disposal Methods
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Potential Contaminant
Migration Pathways Disposal Processes
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Potential Contaminant
Migration Pathways - Groundwater
Transport (Present and Future)
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Potential Contaminant
Migration Pathways Physical Disturbance
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Groundwater Movement
through Cells
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Potential Groundwater
Transport from Containment
Cells
Upward groundwater flow.
Predicted discharge concentrations
below risk-based criteria.
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Potential Physical
Disturbance of Containment
Cells
Natural erosion (floods).
Human influence (mining).
Geotechnical stability.
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Slope Instability
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Potential Physical
Disturbance of Cells
Minimal erosion potential due to dike.
Mining controls would avoid impacts.
Slopes are receiving fills.
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Wyckoff/Eagle Harbor
Bainbridge Island, in Central Puget Sound
3,780-acres
Inactive 40-acre wood treating facility
owned by Wyckoff
Adjacent 500-acre Eagle Harbor
Other upland sources of contamination
(Shipyard)
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W. Fish, Portland State University
Wyckoff/Eagle Harbor
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W. Fish, Portland State University
Site History
Shipyard operated from 1903 to 1959 on
the northwest shore of Eagle Harbor,
resulting in releases of metals and organic
contaminants.
1905 to 1988, wood treating operations
were conducted on the southeast shore
involving pressure treatment with
creosote and pentachlorophenol
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W. Fish, Portland State University
Historical Sources
Preservative chemicals were stored in
tanks on the property.
Contamination of soil and ground water at
wood treatment facility led to seepage
into adjacent sediments.
Wastewater discharged into Eagle Harbor
for many years; storing treated pilings
and timber in the water continued until
the late 1940's.
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W. Fish, Portland State University
Contaminants of Concern
Shipyard: Levels toxic to marine life
polyaromatic hydrocarbons (PAHs) and
other organics
heavy metals such as mercury, copper,
lead, and zinc
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Contaminants of Concern
Wyckoff facility, soil and groundwater are
contaminated with:
Creosote
Accompanying PAHs
pentachlorophenol (PCP)
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Discovery
1984: NOAA investigations of the Harbor
revealed that sediment, fish, and shellfish
from Eagle Harbor contained elevated
levels of PAHs
EPA required Wyckoff to conduct
environmental investigation activities
under RCRA, and the state required
immediate action to control stormwater
runoff and seepage of contaminants
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W. Fish, Portland State University
CERCLA Operable Units
1991, EPA defined three operable units at
the Wyckoff/Eagle Harbor site:
Wyckoff (OU1)
East Harbor (OU2)
West Harbor (OU3)
Wyckoff Facility groundwater (OU4, 1994)
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W. Fish, Portland State University
East Harbor Capping (OU2)
Sept 1993-March 1994, EPA and the
Corps of Engineers covered contaminated
sediments in the East Harbor
Cap of clean sediment at water depths of
17 m and 13 m, respectively.
Sediment was dredged from the
Snohomish River as part of an annual
project for ship navigation
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W. Fish, Portland State University
Capping Methods
Split Hull: Fast but uneven.
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W. Fish, Portland State University
Capping Methods
Hydraulic washoff:
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W. Fish, Portland State University
West Harbor CDF (OU3)
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W. Fish, Portland State University