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Sediment Contamination andSediment Contamination andSustainable Remediation Options forSustainable Remediation Options for
the Kingston Inner Harbourthe Kingston Inner HarbourKen J. Reimer, Viviane Paquin, Tamsin Laing, Astrid Michels
and David BurbridgeEnvironmental Sciences Group, Royal Military College of
Canada, Kingston, Ontario
2011 RPIC Federal Contaminated Sites Regional Workshop
LaSalle Causeway
HWY 401
Location of the ProjectLocation of the Project
Kingston Inner HarbourKingston Inner Harbour19241924
Kingston Inner HarbourKingston Inner Harbour
Belle Park former landfill1974Originally the site of a marsh that looselyconnected Belle Island to the west shore ofthe Great Cataraqui River, the landfill wasin operation from 1952 to 1974
Davis Tannery 1937From 1912 to 1967, chromium-contaminated effluents from the DavisTannery were discharged, untreated, intothe Marsh
Kingston Inner HarbourKingston Inner Harbour
2002 - KEAF Inner Harbourworking group
2005 - City of Kingston CIPfor brownfields revitalization
2007- the Rideau Canalinscribed as a UNESCO WorldHeritage Site
2010 - City of Kingstonintegrated communitysustainability plan
Cataraqui River Stakeholder GroupCataraqui River Stakeholder GroupFormed June 2006 to provide guidance to assess sedimentFormed June 2006 to provide guidance to assess sediment
contamination and develop management strategycontamination and develop management strategy
RIDEAU RENEWAL INC.
Overall Project AimsOverall Project AimsEndorsed by KIH Stakeholders in 2006Endorsed by KIH Stakeholders in 2006
1. Identify risks to human andecological health
2. Delineate areas ofunacceptable risk
3. Identify and contain all offsitesources of contaminants
4. Identify sustainable, risk-based remediation options
5. Engage the communitythroughout the remediationprocess
Reaffirmed at successivestakeholder meetings
FCSAP process for managingaquatic contaminated sites
(COA Framework flowchart modified from EC and MOE, 2008)
Benthic CommunityImpaired?
EXAMINE AVAILABLE DATA
Toxicity or BiomagnificationPossible?
Any COPCSignificantly >
Reference
SCREENING
PRELIMINARYQUANTITATIVE
ASSESSMENT
DETAILEDQUANTITATIVE
ASSESSMENT
Biomagnification aConcern? Sediments
Toxic?
CONSTRUCT DECISION MATRIX
EnvironmentalRisk?
Deeper Sediments atPotential Risk?
MANAGEMENT ACTIONS
KIH ReportKIH ReportApplication of the FCSAP process and COA FrameworkApplication of the FCSAP process and COA Framework
Chapter I: Literature review. Distributed April 2009
Chapter II: Spatial distribution of contaminants in sediments of theKingston Inner Harbour. Distributed December 2009
Chapter III: Ecological effects: Evaluation of bioaccumulation ofcontaminants in biota, sediment toxicity, and benthiccommunity structure. Distributed May 2010
Chapter IV: Human Health and Ecological Risk Assessment.Distributed May 2010
Chapter V: An options analysis of management scenarios for theKingston Inner Harbour. Distributed March 2011
Chapter 1:Chapter 1:Literature review summaryLiterature review summary
• There have been extensivestudies on various aspects ofthe KIH– Land use, flora and fauna– Contaminant sources and
pathways– Water quality– Sediment quality– Sediment pore water quality– Biological effects
• Water quality is generallygood
• Sediment contaminationSW of Belle Park is themain area of concern
Chapter II. Spatial distribution ofChapter II. Spatial distribution ofcontaminantscontaminants
1. Cr, Pb, Zn, Cu, Hg, As, PCBs, and DDT
exceed the PEL and occur at significantly
higher levels (p<0.05) at impacted sites
vs. reference sites.
2. PCBs, DDT and organic mercury are
substances that may biomagnify.
3. Dilution effects with clean sediments
is limited due to low-energy flow and
resuspension of contaminated sediments.
Mean =1054 ppm
Mean =51 ppm
PCBconcentrationsthroughoutmuch of theinner harbourare above theCCME ISQGof 34.1 ppb
PCBconcentrationsdelineated byincrementalexceedences ofthe PEL
Chromiumconcentrationsdelineated byincrementalexceedences ofthe PEL
Chapter 3:Chapter 3:Biological effectsBiological effects
Sediment toxicityBioaccumulation Benthic CommunityImpairment
-1.5 1.5-1
.01.
0
Cralkalinity
%clay
%silt
%sandBC3
BC7
BC4
BC8
BC6
BC1
BC2
BC5
BC9
λ2=0.246
λ2=0.61Eurasian milfoil Cattails
Pathways
Receptors
Contaminated Food
Ingestion
Der
mal
Inge
stio
n
As, Cr, Cu, Hg, Pb, Zn,DDT, PCBsSediment
Biological Uptake
Chapter IV:Human health risk assessment
Der
mal
Contaminated
Food Ingestion
As, Cr, MeHg, PCBs(All)
Pb and Hg (child andtoddler only)
Chapter IV:Chapter IV:Ecological risk AssessmentEcological risk Assessment
Exposure pathways evaluated were incidental sediment ingestion and consumption ofcontaminated foods
Receptor As Cr(III) Cu MeHg Pb Zn TotalPCBs
Muskrat No risk Risk No risk N/A No risk No risk No riskMink No risk No risk No risk No risk No risk No risk Risk
Red-wingedblackbird No risk Risk No risk N/A No risk No risk N/A
Mallard duck No risk Risk No risk N/A No risk No risk No riskGreat blue heron No risk Risk No risk No risk No risk No risk No risk
Osprey No risk Risk No risk No risk No risk No risk No risk
SeveralreceptorsareatriskfromexposuretoCr(III)duetoincidentalsedimentinges<on.Minkshowpoten<alriskfromPCBs
duetoconsump<onofcontaminatedfish
Table1:ERAriskcharacteriza<on
Direct evidence of ecologicalDirect evidence of ecologicaleffects to Brown Bullheadeffects to Brown Bullhead
• High frequency (80%) of deformities in BrownBullhead caught south of Belle Park– Compared with 10% from reference area
• Much greater severity of deformities for fish from theimpacted area
Based on this evidence alone the KIH is classified as aclass I site (high priority for action) according to theFCSAP aquatic sites classification system
Chapter V: development of aChapter V: development of aRemediation/ Risk Management StrategyRemediation/ Risk Management Strategy
Area ofbiologicaleffects
Clean allto ISQG
Sediment remediation experts and stakeholdermembers were brought together to consider thefollowing:
– Information gaps (biological effects,contamination sources)
– Remediation strategy
– Risk management objectives
June 2010 WorkshopOptions Analysis of
Remediation / Risk Management strategy
Remediation strategyRemediation strategyanalysisanalysis
Strategy Decision/Reasons
No action Potential human and ecological health risks from thesediment and biological contamination
Monitorednatural
recovery
Contaminants are persistent; high sediment re-suspension rate in the KIH
In-situcapping
Water depth not adequate to accommodate the cap, KIHhas very soft sediments, long-term maintenance issues
Dredging Sufficient depth for dredging to occur, no long-termmaintenance issues, high public acceptance
Expert group confirmed that dredging was the onlyfeasible remediation strategy
Sediment stratigraphy profileSediment stratigraphy profile
0
10
20
30
40
50
60
70
80
90
100
C1 C2 C3 C6 C5 C4 C7 C8
Core
Dep
th o
f sed
imen
t / cm
Clay
Peat
Gyttja
Peat: SW of BellePark
Clay: under most of southernKIH
Dredge to clay or peat layer
Sediment managementSediment managementstrategystrategy
Risk-based sediment quality objectives(SeQO) were developed using HH andERA results and a site allocation factor of0.6
• SeQO for Cr–650 ppm–based on ecological receptor(mallard duck)
• SeQO for PCBs–304 ppb–based on human fishconsumption (largemouthbass)
Management area to achieve riskManagement area to achieve riskbased SeQO Cr (650 ppm)based SeQO Cr (650 ppm)
Area warrantingmanagementaction is 20.8 ha
Management area toManagement area toachieve 304 ppb for PCBsachieve 304 ppb for PCBs
Area warrantingmanagementaction is 29.6 ha
Remediation of the harbour should eventually result indeclines in tissue Cr and PCB concentrations to levels thatpose acceptable risk to human and wildlife.
Management Area toManagement Area toachieve achieve SeQOSeQO for all CoCs for all CoCs
Total surfacearea of 32.2 ha
Removal depth of50 cm
Total volume of161,000 m3
Sustainable Management ofSustainable Management ofDredged Contaminated MaterialsDredged Contaminated Materials
• LCA used to compareenvironmental impacts of twosediment dewatering and disposalalternatives for the KIH:
Impact 2002+ Life Cycle ImpactAssessment Methodology (Joliet etal. 2003)
1. Mechanicaldewatering anddisposal
2. Naturaldewateringand disposal
Natural Vs MechanicalNatural Vs Mechanical
Human health
Poin
ts)
Natural Dewatering System Mechanical Processing System
ResourcesClimate changeEcosystem quality
540 Pt480 Pt
Effect of Dredged VolumeEffect of Dredged Volume
At a dredged sediment volume of above 33,000 m3 themechanical process becomes more sustainable
10 percent difference
Mechanical dewateringMechanical dewateringprocessprocess
DredgedMaterial
ScalpingScreen
> 6 mm
Debris
Coarse SandRemoval
CoarseSand
0-6 mm
FineSand
< 150 µm
150 µm – 6 mm 63-150 µm
< 63 µm (sludge)
MembranePress
Fine SandRemoval
Add flocculantsand coagulants
FilterCake
< 63 µm
Impacted area sediments5% sand and 95% fines
Landfill Reuse Reuse Landfill
30
Effect of Grain-sizeEffect of Grain-size
10 percent difference
66 percent difference
LCA can show differences in impacts between remediation alternatives
Questions?Questions?