Lue HingKappeEcoRev 090803

Ecosystem-Based Approach ToRemediation of PCB Contaminated River Sediments: A Case Study: 

Ecosystem-Based Approach To Remediation of PCB Contaminated River Sediments: A Case Study Presented as the Kappe Lecture Fall, 2003 Sponsored by the American Academy of Environmental Engineers Presented by Cecil Lue-Hing, D.Sc., P.E., DEE Cecil Lue-Hing & Assoc. Inc., Chicago

Kappe Lecturers: 

Kappe Lecturers *H. Gerard Schwartz 1989 *William J. Carroll 1991 *Michael C. Kavanaugh 1993 *Daniel A. Okun 1995 Orris E. Albertson 1997 *R. Rhodes Trussell 1999 *Glen T. Daigger 2001 *Paul L. Busch 1990 C. Joseph Touhill 1992 *Davis L. Ford 1994 Ira L. Williams 1996 Richard D. Kucenrither 1998 W. Wesley Eckenfelder 2000 James Crook 2002 *Cecil Lue-Hing 2003 * Member – National Academy of Engineering

Chemical Impacts to the River: 

Chemical Impacts to the River Emulsified PCB released from carbonless copy paper production 1954-1971 Several mills and POTWs 279,000 to 881,000 pounds of PCB released WDNR estimates 63,000 pounds of PCB remain in the River sediment Much buried below cleaner sediments WDNR estimates 275 to 485 pounds of PCB transported to Green Bay annually COCs include PCB, Mercury and Pesticides

The Lower Fox is Unique: 

The Lower Fox is Unique Highly Controlled Flow Regime ~ Flow Controlled by Lake Winnebago Locks and Dams ~ Low Ratios of High Flow : Average Flow * Sediment Movement Predominantly Depositional Reaches 1, 3, 4A, and 4B Heavy Recreational Use Highly Developed River Banks, In General Wide Spectrum of Sediment-Associated Toxics Flow into the River Already Exceeds WQC for PCBs

Slide8: 

INSERT FIGURE 1 FROM THE REPORT

Slide9: 

Lower Fox River Increasing ‘Flashiness’ Ratio of 100 Year Flood / Average Flood vs. Drainage Area 24 Rivers of Comparable Regional Physiography in the Midwest Chippewa River

Slide11: 

INSERT FIGURE 2 FROM THE REPORT Drainage Areas Lake Winnebago and Lower Fox River

PRAP Remedial Action Objectives: 

PRAP Remedial Action Objectives Achieve Surface Water Quality Criteria Protect Human Health – Remove Fish Advisories Protect Ecological Receptors Reduce transport of PCBs into Green Bay and Lake Michigan Minimize downstream PCB movement during remedy implementation

Panel Strategy: 

Panel Strategy Satisfy the 5 RAOs Add a Sixth RAO Enhance, Rehabilitate Habitats Fishery, Wildlife, Wetlands Risk Reduction Management Rapid Exposure Reduction to Organisms Reduce Exposure which is Governed by the Resuspendable Sediment

Panel’s Remedial Action Objectives: 

Panel’s Remedial Action Objectives Achieve Surface Water Quality Criteria Protect Human Health – Remove Fish Advisories Protect Ecological Receptors Reduce transport of PCBs into Green Bay and Lake Michigan Minimize downstream PCB movement during remedy implementation Rehabilitate, improve and maintain natural resources and public use

Potentially Applicable Options: 

Potentially Applicable Options Natural Attenuation / Recovery In-Situ Treatment Dredging Landfill without treatment Ex-Situ treatment (e.g., vitrification) Capping

Natural Attenuation : 

Natural Attenuation Will Occur Regardless of Remedy Chosen Will Enhance any Remedy Selected Not Controllable Slow Process in the Lower Fox River Not Effective for Rapid Risk Reduction Except in Conjunction with Other Approaches

In-Situ Treatment: 

In-Situ Treatment Available Technology is Premature Nothing Available is Applicable to the Lower Fox River

Dredging: 

Dredging Sediment Removal Feasible on LFR Small Scale Demonstration Projects Achieves Mass Removal Concerns Resuspension Residual Contaminated Sediments Interim Exposure Wastewater Generation Solids Disposal Time Horizon for Recovery

Residual Contamination: 

Residual Contamination Sediment above the “cut-line” that remains after dredge passes Consistently observed Quality and quantity uncertain Only anecdotal data; no research yet Must plan for either Multiple dredging passes Dilution by “thin-layer” cap

Residual Contamination: 

Residual Contamination

Impact of Exposed Sediments During Dredging: 

Impact of Exposed Sediments During Dredging Dredging Exposes Higher Concentration of PCBs in Large Areas Deeper PCBs Not in Equilibrium with Water Column Increased Releases of Pollutants When Exposed Extended Exposure of More Highly-Contaminated Residual Sediment Over Large Areas

Dredging Wastewater: 

Dredging Wastewater Dredged water must be treated and returned to river Hydraulic dredges Increased volume & flow from dilution Erratic flow & quality characteristics Mechanical dredges Less volume increase, but Transport and handling a problem Discharge limited by effluent WQ and flow

Wastewater Volume Data: 

Wastewater Volume Data Seven comparable remedial dredging projects (including Lower Fox demonstration projects): Wastewater flows from 1,000 to 11,000 gal/cy of sediment dredged Average wastewater flow of 4,100 gal/cy Range reflects: Variability in dredge operation, especially in “hot spots” Number of “cleanup” passes 1999 SMU 56/57 demonstration project averaged about 2,400 gal/cy

Result : Time Constraint for Dredging: 

Result : Time Constraint for Dredging Large Volumes of Carrier Water WQBEL are not achievable by current recognized wastewater treatment technologies Assimilative Capacity of LFR is Restrictive 4.25 MGD discharge from best available treatment Limits dredging to about 1,050 cy/day, or only 1/5 of that assumed by PRAP for Reaches 3 and 4 Full-Scale Lower Fox River Dredging will be difficult and prolonged

Review of Exposure and Risk Sources in the River: 

Review of Exposure and Risk Sources in the River Surficial sediment releasing PCBs via Resuspension of surficial sediment Resuspension and migration of PCBs Uncertain dynamics of fine-grained, cohesive sediment Benthic organism interaction with surficial sediment Typically limited to upper 10-15 cm Direct sediment/PCB release via bioturbation PCB transport via food chain Dissolved release Diffusive release No significant advective transport

Capping: 

Capping Capping is Feasible in the Lower Fox River Provides Expedited Reduction of Benthic Exposure to PCB and Other Toxics Armors Sediment to Eliminate Resuspension Reduces uncertainty of sediment instability Compatible with Ecosystem Rehabilitation

What Can a Cap Do?: 

What Can a Cap Do? Responds to each of the sources of exposure and risk on the Lower Fox River Armor sediment for containment Design for stability in high flow conditions High confidence in describing dynamics of noncohesive, granular media Eliminates uncertainty of existing sediment dynamics Separate contaminants from benthic organisms Reduce dissolved release by increasing transport path/resistance Provides opportunities for habitat development

Cap Design and Stability: 

Cap Design and Stability Protect Against Major Erosion Events Can be Designed to be Stable in Any Flow Must Ensure Resulting Design is Consistent with River Uses Proposed Design Assures Stability against 100-year flood flow Shear Stresses x 3 Stable for USACE Standard Project Flood Removal of Dams for Fish Migration is feasible in the Appleton to Little Rapids Reach

Maximum Annual FloodLower Fox River at Rapide Croche Dam: 

Maximum Annual Flood Lower Fox River at Rapide Croche Dam SPF 500-yr 10-yr 2-yr 100-yr 50-yr 25-yr

Ecosystem-Based Remedy: 

Ecosystem-Based Remedy Subaqueous Capping of Contaminated Sediments Sand, Fine and Coarse Gravel or Cobble for Armoring Typical cap thickness of 12 inches Reach 1 – approximately 180-240 acres Reach 3 – approximately 120 acres Reach 4A – approximately 360-600 acres Habitat Creation and Enhancement Fishery, Water-Dependent Wildlife Continued Removal of Contaminated Sediments in Reaches 4B and 5 via Navigational Dredging Evaluation of Opportunities in Green Bay

Reach-by-Reach Schedule Comparison: 

Reach-by-Reach Schedule Comparison

Slide33: 

River-Wide SWAC vs. Time Rehabilitation Plan vs. PRAP

Cumulative Exposure vs. Time(assuming 5 % natural attenuation): 

Cumulative Exposure vs. Time (assuming 5 % natural attenuation) Rehabilitation Plan Dredging - Residuals Management Dredging - Minimal Overdredging

Basis for Remedy Selection: 

Basis for Remedy Selection Consistency with Characteristics of LFR Expedited Achievement of PRAP RAOs (5) Expedited Achievement of Low SWAC Levels Expedited Exposure Reduction Expedited Achievement of the Sixth RAO Habitat Rehabilitation and Creation

Update: Current Status: 

Update: Current Status January 2003: ROD for Reaches 1 and 2 June 2003: ROD for Reaches 3, 4 and 5 Decision: Dredge all sediments over 1 ppm >> 7.25 million cubic yards to landfill Billions of gallons of wastewater PCB and Mercury discharge limits to be waived WDNR and EPA claim it can be done in 10 years Short-term impacts were not quantified Capping identified as a “Contingent Remedy” for certain areas should dredging fail to achieve objectives

Independent Expert Panel and Support Groups: 

Independent Expert Panel and Support Groups Organized, Funded, Not Controlled By API Experienced Senior National Experts – 7 CO, IL, LA, MA, UT, VT Contributing Reviewers from Wisconsin - 5 Peer Reviewers, National Experts – 2 UW Madison, Johns Hopkins Scientific, Engineering, and Technical Support The Johnson Company, Montpelier, VT Project Scheduling and Implementation Support Project Control Companies, Westford, MA

Mandate : Recommend a Remedy: 

Mandate : Recommend a Remedy No a priori Constraints Not Driven by Costs No Technology Biases Independent of Sponsors Consensus, Effective, Expeditious

The Panel’s Approach- STUDY THE LOWER FOX RIVER -: 

The Panel’s Approach - STUDY THE LOWER FOX RIVER - Reviewed Relevant and Available Existing Documents Toured the River Reviewed WDNR’s 2001 RI/FS and Plan Used JCO for Data/Engineering Support Used PCC for Implementation Support Meetings, Conferences – 18 Months

Guiding Principles: 

Guiding Principles Adopt the Ecosystem Approach recommended by the IJC for the Great Lakes Basin Consider the NRC/NAS Risk Management Strategy for PCB-Contaminated Sediments Conceive and implement the Remedy integrally with the restoration and enhancement of ecological and habitat conditions

Slide41: 

100-year flood Western Wisconsin Floods

Green BayNatural Resources Recovery: 

Green Bay Natural Resources Recovery Remedies considered for the River are not feasible for the Bay because of: Wide-spread area of contamination Chronic recirculation of sediments (seiche effects) Extensive mixing of sediments occurs in the Inner Bay Best Benefits for the Bay: Rapidly reduce inputs to the Bay from the River Consider opportunities for habitat and natural resource enhancement projects

Slide43: 

Green Bay Lower Fox River East River After Chen and Lee, 1991.

Questions ?: 

Questions ? Contact: Cecil Lue-Hing, PhD. Phone: 630-986-5751 email: clhai@aol.com Panel submissions to WDNR can be found at www.johnsonco.com - see Lower Fox River Link