Priority Zones for Sediment ManagementSuncor Three priority zones for management; 1. Volume near Suncor dock, (25,700m3) 2. Volume near Shell dock (5,500m3), and Shell 3. Volume near Guthrie Park (3,750m3)GuthriePark These areas represent depositional areas downstream from the original source.
St. Clair River Priority Areas1. Sediment Chemistry • 61% of sediment samples more than 2 mg/kg Hg (Provincial SEL) • Hg in buried sediment up to 5 times higher than surface sediment in some places3. Sediment Toxicity • No strong evidence of toxicity to Hg5. Changes to Benthic Community • No strong evidence of community changes due to Hg compared to reference sites7. Potential for Biomagnification • Negligible risk to wildlife that eat fish • Risks to some fish species • Priority Areas identified based on risk to fish Management Goals Removal of Hg-contaminated sediment: 1. as a source to downstream sites 2. to promote local risk reduction 3. for contaminant mass removal
St. Clair River Remediation Scenarios Zone 1a Zone 1b Zone 2 Zone 3 Total (Suncor) (Suncor) (Shell) (Guthrie)Sediment Volume 7,350 18,350 5,500 3,750 34,950(m3)Sediment Area 14,700 36,700 11,000 7,500 69,900(m2)Lowest Practical Isolation Monitored Isolation IsolationRemediation Cost capping Natural capping cappingScenario RecoveryCosts ($) 1.6 M 0.5 M 1.5 M 1.3 M 4.9 MGreatest Dredging Isolation Dredging DredgingRemediation Cost with residual capping with withScenario capping residual residual capping cappingCosts ($) 5.7 M 2.6 M 5.0 M 4.2 M 17.5 M
1 2Consultants Technical Team Communications (ENVIRON) 2 Committee 31) SMO report submitted.2) After selection of preferred option based on technical feasibility, engage 4 community, stakeholders, FNs, etc.3) Document response. 54) Adjust preferred options, if required. Risk Managers5) Make recommendation to Risk Managers. (MOE/EC Senior Management?)6) Decision made based on technical and socio-economic 6 considerations. 77) Implementation. Implementation
Conceptual Sediment Management ScheduleAdditional Studies in support of SMO – 2012Decision on preferred SMO – 2013Engineering Design/ EA – 2014-2015Construction (assume 2 to 5 years) – 2016-20??Long-term monitoring – 15 years
Project Overview• Historic operation of coal gasification plant and steel operations;• Approximately 675,000 m3 of contaminated sediment (PAHs & heavy metals);• Project Cost $105 M;• Project Schedule 2014-2022
Randle Reef (RR) Statistics Largest PAH Site in the Great Lakes • RR second largest site in Canada; Remediation Project equivalent to: • 40 dump truck loads (338 tonnes of pure PAHs); • Filling a professional sporting arena 3 times over (675,000 cubic metres); PAH-contaminated sediment • PAHs are linked to cancer; and • Known to cause developmental & reproductive deformities in fish and wildlife.
Sediment Project Components U.S. Steel Channel• Construct a 7.5 hectare (18.5 acres) Engineered Containment Facility (ECF) over the most highly contaminated sediment (130,000 m3 in-situ);• Using a combination of hydraulic and mechanical dredging, remove 500,000 m3 and place within ECF;• Thin Layer Capping of 40,000 m3 of marginally contaminated sediment• Cap U.S. Steel Intake/Outfall Channel sediments 5,000 m3• Cap ECF and construct a port facility and open green space.
Project ObjectiveObjective:Remove the major source of highlycontaminated PAHs from Hamilton Harbour
Construction Components1. Installation of double steel sheetpile walls (ECF structure);2. Mechanical dredging between ECF walls;3. Production dredging and thin layer backfill;4. Capping in U.S. Steel Channel; and5. Installation of ECF cap.
U.S. Steel Channel Capping• 25 m wide channel;• Contaminated sediment up to 1.5 m thick and underlain by slag;• Designed to limit potential impacts associated with the ECF on U.S. Steel facilities (water intake and outfall); and• Dredging not a remedial option for this area due to: – Potential instability of the U.S. Steel dock wall; and – Low tolerance for suspended solids (facility intake pipe).
Dredged Material ManagementWhat happens to dredged material after it is placed in the ECF? Sediment management and effluent treatment flow diagram
Filling the ECF with Dredged Material Clean Cap installed on top of sediment The ECF is filled with dredged material while de-watering the dredged material
Capping the ECFThe ECF capping system will consist of several layers: 1. Foundation layer; 2. Underliner drainage system; 3. Hydraulic barrier layer; 4. Overliner drainage system; 5. Paved surface (in the port facility area); 6. Vegetative cover (in the greenway area); and 7. Stormwater management systems.The overall thickness of the cap is approximately 3m
ECF Cap – Multiple Layers • Hydraulic barrier seals contaminated sediment within the ECF
Assessing the Effectiveness of the Randle Reef Remediation• Baseline studies (prior to remediation) have been conducted 2005-2011.• To be compared with studies undertaken during remediation, and post-remediation studies conducted again in 5 to 10 years
Assessing the Effectiveness of the Randle Reef Remediation• 8 Studies to Assess the Clean- up
Indicator Studies OverviewIndicator Study Baseline Monitoring During Post Remediation Remediation1. Suspended Sediment 2005/06, 2006/07, 2011/12, Yearly TwiceMonitoring Chris Marvin 2012/13, 2013/142. Wild Fish Health Study 2005/06, 2007/08 Once Year 1 and 7Mark McMaster3. Fish Tumour Study 2001/02, 2005/06, 2007/08 None planned Year 1 and 7Mark McMaster 2011/124. Fish Enzymes, Cell-lines 2005/06 and 2006/07 Once Onceand SPMD Joanne Parrott5. Immunity Effects on 2012/13 TBD TBDBivalves Patty Gillis6. New Genetic Endpoints 2012/13 TBD TBDJames Quinn, Jason Miller7. Benthic Invertebrate 2005/06, 2006/07, 2007/08 None planned Year 1 and 7Assessment Danielle Milani 2013/148. Water Quality Monitoring 2008/09 2011/12, 2012/13, None planned TwiceDebbie Burniston 2013/14
Why Clean Up Randle Reef?• Environmental Benefits – preserve health of harbour – improve fish and wildlife habitat reduce spread of contaminants through the harbour – essential to delisting Hamilton Harbour as an Area of Concern• Economical & Social Benefits – estimate of $126M in economic impact to the community (job creation, business development, tourism) – enhances recreational opportunities (beaches, boating, fishing) – enhances shipping and port facilities – promotes a positive image of the harbour and community as a place to live and work
Draft Construction and Cost ScheduleECF Construction $42.5 MDredging/Management $25.5 MECF Capping $37 M $105 M $ Million
Where Are We?• Engineering Design: Completed in Fall 2011 • Environmental Assessment: To be completed by Fall 2012, public comment period Summer 2012 • Project Funding Partnerships: To be completed by Summer 2012 • Construc;on: To start in 2014/15 and be completed by 2022/23
St. Marys River – Sediment Management RAP Workshop February 8, 2012
The Area East of Bellevue Marine Park• “Algoma sailing club embayment”• Second major depositional zone in the St. Marys River downstream of the industrial sources in Sault Ste. Marie.
East of Bellevue Marine ParkManagement Action Required
Decision-Making Framework East Bellevue Marine Park Sediment Toxicity Benthos Assessment Site Chemistry Alteration EC37 No further actions needed Determine reason(s) for benthos EC36 alteration Determine reason(s) for sediment EC52 toxicity EC30 Management actions required EC32 CS10 EC34 EC35 EC31 Management actions required EC64 Management actions required
Lake George Channel Management Action Required
Decision-Making Framework Lake George Channel Sediment Toxicity Benthos Assessment Chemistry Alteration Site DBCR Management actions required 1 Management actions required EC39
Conclusions• East Bellevue Marine Park – highest contamination, greatest effects seen.• Mgmt actions indicated at 7 sites in EBMP and 2 sites in LGC (some sites more severe than others).• No mgmt actions indicated for BMP.• Sampling coverage sufficient for the purposes of advancing the sediment management plan for the St. Marys River.
Additional Studies• Sediment Stability Modelling undertaken by Dr. Krishnappen – Assess stability of sediment at depth: Only top 5 cm is susceptible to erosion.• In-situ Flume work undertaken by Hans Biberhofer – Assess erosional resistance of surface sediments.• Coring Study undertaken by Debbie Burniston – Limited vertical profile of sediment chemistry – near complete• Porewater Chemistry undertaken by consultant – To understand relationship between porewater and toxicity• Literature Review on oil and grease and physical effects – To understand physical effects of oil and grease on benthos• STING work undertaken by Hans Biberhofer – To estimate the volume of soft sediment at depth• Geotechnical/CPT undertaken by consultant – To assess the geotechnical and geochemical properties of soft sediment at depth
Next Steps?• Unable to directly link biological response to potential COC - What do you recommend?• Assess sediment deposition rates and associated quality• Assess Sediment Management Options
Thank you! Roger Santiago Head, Sediment Remediation Unit Environment Canada Tel: 416-739-5876 E-mail: firstname.lastname@example.org