Presented to

Presented by

Best Practices Group

Clay Patmont Anchor Environmental, LLC

Emerging Trends in Emerging Trends in Contaminated Sediment Contaminated Sediment

CleanupCleanup

August 28, 2008

Presentation OutlinePresentation Outline

•• Overview of emerging trendsOverview of emerging trends––Regulatory and industry initiativesRegulatory and industry initiatives––Key technical developmentsKey technical developments

•• Dredging technology limitationsDredging technology limitations•• Monitored natural recovery and capping Monitored natural recovery and capping

case studiescase studies•• Low cost in situ treatmentLow cost in situ treatment

––Adaptive ManagementAdaptive Management

Regulatory and Industry InitiativesRegulatory and Industry Initiatives

•• EPAEPA’’s 11 Sediment Management Principless 11 Sediment Management Principles•• National Academy of Sciences (NAS)National Academy of Sciences (NAS)

–– A Risk Management Strategy for PCBA Risk Management Strategy for PCB--Contaminated SedimentsContaminated Sediments–– Sediment Dredging at Superfund Megasites: Assessing EffectivenesSediment Dredging at Superfund Megasites: Assessing Effectivenesss

•• Sediment Management Work Group (SMWG)Sediment Management Work Group (SMWG)•• EPA Contaminated Sediment GuidanceEPA Contaminated Sediment Guidance•• EPA Contaminated Sediments Technical EPA Contaminated Sediments Technical

Advisory Group (CSTAG)Advisory Group (CSTAG)•• State ProgramsState Programs

EPAEPA’’ss 11 Sediment Management 11 Sediment Management PrinciplesPrinciples

1.1. Control Sources EarlyControl Sources Early

2.2. Community InvolvementCommunity Involvement

3.3. Coordinate With Other Coordinate With Other

StakeholdersStakeholders

4.4. Sediment Stability ModelSediment Stability Model

5.5. RiskRisk--Based FrameworkBased Framework

6.6. Carefully Evaluate DataCarefully Evaluate Data

7.7. SiteSite--Specific Risk Specific Risk

ManagementManagement

8.8. Risk Driven Goals Risk Driven Goals

9.9. Maximize Institutional Maximize Institutional

Controls Controls

10.10. RiskRisk--Driven Remedies Driven Remedies

11.11. Monitor RemedyMonitor Remedy

National Academy of Sciences National Academy of Sciences (NAS)(NAS)

•• A Risk Management Strategy for PCBA Risk Management Strategy for PCB-- Contaminated SedimentsContaminated Sediments–– Overall risk reduction focusOverall risk reduction focus–– No presumptive remedyNo presumptive remedy

•• Sediment Dredging at Superfund Megasites: Sediment Dredging at Superfund Megasites: Assessing the EffectivenessAssessing the Effectiveness–– Site conditions determine dredging effectivenessSite conditions determine dredging effectiveness–– Risk reduction focus (not mass removal)Risk reduction focus (not mass removal)

Sediment Management Work GroupSediment Management Work Group

1.1. 1010--year historyyear history2.2. Industry lessons learnedIndustry lessons learned3.3. Adaptive management frameworkAdaptive management framework4.4. Collaboration with EPA and CorpsCollaboration with EPA and Corps

•• Joint technical conferencesJoint technical conferences•• Sediment Remediation GuidanceSediment Remediation Guidance

EPA Contaminated Sediment GuidanceEPA Contaminated Sediment Guidance

1.1. Focus on risk reduction, not simply removalFocus on risk reduction, not simply removal2.2. Realistic, siteRealistic, site--specific evaluation of optionsspecific evaluation of options3.3. Comparative net risk reduction evaluationComparative net risk reduction evaluation4.4. Combined remedies at complex sitesCombined remedies at complex sites5.5. Adaptive management based on new dataAdaptive management based on new data6.6. Compare costs and benefitsCompare costs and benefits

•• Disproportionate cost analysisDisproportionate cost analysis

EPA Contaminated Sediment EPA Contaminated Sediment Technical Advisory Group (CSTAG)Technical Advisory Group (CSTAG)

•• Site monitoring and advisory roleSite monitoring and advisory role•• Large, complex, or controversial sitesLarge, complex, or controversial sites•• Limited number of sites currently in programLimited number of sites currently in program•• EPA regional and headquarters interactionsEPA regional and headquarters interactions

State Regulatory InitiativesState Regulatory Initiatives

•• Existing State programsExisting State programs–– Washington, Florida and CaliforniaWashington, Florida and California–– Disproportionate cost analysesDisproportionate cost analyses

•• Emerging State programsEmerging State programs•• Interstate Technology & Regulatory CouncilInterstate Technology & Regulatory Council

Key Technical DevelopmentsKey Technical Developments

•• Case studies of biological recoveryCase studies of biological recovery–– Monitored natural recoveryMonitored natural recovery–– CappingCapping–– DredgingDredging

•• Dredging technology limitationsDredging technology limitations•• Low cost in situ treatmentLow cost in situ treatment

Biological Recovery Case StudiesBiological Recovery Case Studies

•• Monitored natural recoveryMonitored natural recovery–– Bellingham Bay, WA (20+ years)Bellingham Bay, WA (20+ years)–– Grasse River, NY (15+ years)Grasse River, NY (15+ years)

•• CappingCapping–– St. Paul Waterway, WA (15+ years)St. Paul Waterway, WA (15+ years)–– Eagle Harbor, WA (15+ years)Eagle Harbor, WA (15+ years)

•• DredgingDredging–– Commencement Bay, WA (25+ years)Commencement Bay, WA (25+ years)–– Duwamish Waterway, WA (30+ years)Duwamish Waterway, WA (30+ years)

Bellingham Bay Site Conditions and Bellingham Bay Site Conditions and Natural Recovery TimelineNatural Recovery Timeline

Chemicals of Potential Concern

Source Control Implementation

Monitoring Record

Mercury & Wood Waste

Mercury - ’70 Wood - ’72, ’78, ’99 Log Pond Cap – ’00/’01

30+ Years RI/FS - ’96, ’98 Pre-RD – ’02

Mercury Release and Source Mercury Release and Source Control: Bellingham BayControl: Bellingham Bay

0

1

2

3

4

5

6

7

8

1960 1970 1980 1990 2000

Mer

cury

Loa

ding

(kg/

day)

Nooksack River – “Background”

Chlor/Alkali Source

Data Source: Patmont et al. (2004)

Temporal Change in Core Profiles:Temporal Change in Core Profiles: Inner Bellingham BayInner Bellingham Bay

-70

-60

-50

-40

-30

-20

-10

00 2 4 6 8 10 12

Sedi

men

t Dep

th (c

m)

19701975

1996

Sediment Mercury (mg/kg)

Data Source: Patmont et al. (2004)

Natural Recovery Biological Natural Recovery Biological Endpoint: Sediment ToxicityEndpoint: Sediment Toxicity

Toxicity tests:Toxicity tests:–– Amphipod: Amphipod:

acute toxicityacute toxicity–– Larval: Larval:

acute toxicity acute toxicity & abnormality& abnormality

–– Polychaete: Polychaete: chronic toxicity chronic toxicity & growth& growth

2002

Data Source: Patmont et al. (2004)

Safe Seafood Mercury LevelsSafe Seafood Mercury Levels

FDA Guidelines1.0 ppm tissue

EPA Guidelines 0.30 ppm tissue

Bellingham Bay Crab Testing

Ecology Studies (1991)0.06 to 0.15 ppm

PSDDA Program Studies (1991)0.03 to 0.09 ppm

Log Pond Monitoring (2002, 2005)0.01 to 0.03 ppm

Sea

food

Tis

sue

Mer

cury

Con

cent

ratio

ns

Site-SpecificScreening Level 0.18 ppm tissue

Monitored Natural Recovery:Monitored Natural Recovery: Grasse River, Massena, NYGrasse River, Massena, NY

Natural Recovery Biological Natural Recovery Biological Endpoint: Fish Tissue PCB LevelsEndpoint: Fish Tissue PCB Levels

0

500

1000

1500

2000

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

ppm lipid

Brown Bullhead PCB

ROPS Dredging

(26,000 cy)

Data Source: Alcoa (2007)

Source Control

Commencement BayCommencement Bay SuperfundSuperfund Site, WASite, WA

St. Paul Waterway Capping and St. Paul Waterway Capping and Habitat Restoration, Tacoma, WAHabitat Restoration, Tacoma, WA

St. Paul Waterway Sediment St. Paul Waterway Sediment Remediation & Restoration TimelineRemediation & Restoration Timeline

Site Discovery and Hazard Assessment

RI/FS and Cleanup Plan

Remedial Design and Permitting

Post-Construction Monitoring & NRD Settlement

Wood Waste (phenolics), PAHs, Cu

Sediment Toxicity Targeted Containment Remedy Identified

Source Controls Implemented Integrated Cap and Habitat Restoration Design

Physical Integrity and Chemical Stability Biological Productivity/Enhancement

St. Paul Cap After 1988 ConstructionSt. Paul Cap After 1988 Construction

•• Primary measure of project successPrimary measure of project success•• Rapid recolonization by benthic, Rapid recolonization by benthic,

epibenthic, and macrophyte epibenthic, and macrophyte communitiescommunities

•• Indistinguishable from reference areas Indistinguishable from reference areas within a few yearswithin a few years

St. Paul Cap Biological MonitoringSt. Paul Cap Biological Monitoring

St. Paul Cap Performance MetricsSt. Paul Cap Performance Metrics

PHYSICAL•Cap Integrity Confirmed Following Initial Placement•Final Bathymetric Monitoring in Year 15 (2004)•Storm/earthquake contingency monitoring, as needed

CHEMICAL•Chemical Stability and Source Control Confirmed•Final Verification Sampling in Year 10 (1998)

BIOLOGICAL•Primary Criteria •Biological Recovery Within 2 Years of Construction•Biological Enhancement/NRD Restoration •Final Biological Sampling in Year 10 (1998)

Cap Performance Example:Cap Performance Example: Eagle Harbor, WAEagle Harbor, WA

Trawl

Cap Performance Biological Cap Performance Biological Endpoint: Flatfish Liver LesionsEndpoint: Flatfish Liver Lesions

English Sole Liver Lesion TrendsBainbridge Island, WA

0%

10%

20%

30%

40%

50%

60%

1982 1984 1986 1988 1990 1992 1994 1996 1998 2000

Year

Age

-Adj

uste

d Li

ver L

esio

n Fr

eque

ncy

Nisqually/Carr/Colvos Reference

Eagle Harbor

East Harbor Capping

Data Sources: Myers et al. (2001) & WDFW (2002)

Sediment Concentrations and Sediment Concentrations and Flatfish Liver LesionsFlatfish Liver Lesions

0%

5%

10%

15%

20%

25%

30%

35%

40%

0.1 1 10 100Area-Average Sediment PAH Conc (mg/kg dry wt)

Live

r Les

ion

Prev

alen

ce

Eagle Harbor Pre-Cleanup

(1993)

Eagle Harbor Post-Cleanup

(1997-99)Puget Sound Background

Data Source: Anchor (2002)

Commencement BayCommencement Bay SuperfundSuperfund Site, WASite, WA

Blair and Sitcum Blair and Sitcum WaterwaysWaterways

•• PCB, PAH, and PCB, PAH, and metalsmetals

•• Navigation needs Navigation needs importantimportant

•• 1993 1993 -- 1994 1994 dredging and dredging and disposaldisposal

Trawl

Sitcum Waterway Dredging: 93 Sitcum Waterway Dredging: 93 -- 9494

Hylebos, Middle & Thea Foss Hylebos, Middle & Thea Foss Waterway Dredging and Disposal: Waterway Dredging and Disposal: 2002 2002 -- 20052005

Commencement Bay Dredging Commencement Bay Dredging Performance: Fish Tissue PCBsPerformance: Fish Tissue PCBs

English Sole Muscle PCB TrendsCommencement Bay, WA

0

50

100

150

200

250

300

350

400

450

500

1982 1987 1992 1997 2002 2007

Year

Tota

l PC

Bs

(ug/

kg w

et w

t; +/

- 2 s

td. e

rr.)

Nisqually/Carr Reference

Commencement Bay

ROD

Miscellaneous Brownfield

Projects

Hylebos, Middle & Thea Foss Waterway Dredging

(~1,100,000 cy)

Blair & Sitcum Waterway Dredging

(~400,000 cy)

Data Sources: TetraTech (1985), West and O’Neill (2007) & WDFW (2007)

Duwamish Waterway and Harbor Island Duwamish Waterway and Harbor Island SuperfundSuperfund Sites, WASites, WA

Trawl

East Waterway Dredging East Waterway Dredging –– 2003 to 20052003 to 2005

Duwamish Waterway Performance Duwamish Waterway Performance Biological Endpoint: Fish Tissue PCBsBiological Endpoint: Fish Tissue PCBs

English Sole Muscle PCB TrendsDuwamish Waterway, WA

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

1972 1977 1982 1987 1992 1997 2002 2007

Year

Tota

l PC

Bs

(ug/

kg w

et w

t; +/

- 2 s

td. e

rr.)

Nisqually/Carr Reference

Duwamish Waterway

Duwamish/Diagonal, East Waterway, Lockheed &

Todd Shipyard Dredging (~600,000 cy)

Data Sources: Miller et al. (1977), Malins et al. (1982), Metro (1983), EPA (1988), West & O’Neill (2007), WDFW (2007) & Stern et al. (2007)

Ecological Recovery Lessons LearnedEcological Recovery Lessons Learned

•• Documented ecological recovery from Documented ecological recovery from monitored natural recovery and monitored natural recovery and completed capping projectscompleted capping projects

•• Little evidence to date of net ecological Little evidence to date of net ecological recovery from completed dredging recovery from completed dredging projectsprojects

•• Dredging technology limitationsDredging technology limitations

Dredging Technology LimitationsDredging Technology Limitations

•• Environmental dredging Environmental dredging and processesand processes

•• ““4Rs4Rs”” 2008 Report2008 Report•• Management implicationsManagement implications

Conceptual Illustration ofConceptual Illustration of Environmental Dredging and Environmental Dredging and

ProcessesProcesses

Removal

Resuspension

Release

(Water)

Release

(Air)

Residual (Sediment)

Residual

1.1. Undisturbed Residuals: Undisturbed Residuals: Contaminated sediment Contaminated sediment that remains after dredging below the design that remains after dredging below the design interface (i.e., the interface (i.e., the ““neat lineneat line””))

Estimating ResidualsEstimating Residuals

Neat Line

Residual Sediment

What are Residuals?

2.2. Generated Residuals: Generated Residuals: Contaminated sediment Contaminated sediment dislodged but not removed by dredgingdislodged but not removed by dredging

Primary Sources of ResidualsPrimary Sources of Residuals

Contaminated Sediment

Clay

SandBedrock

Nepheloid LayerNepholoid layer flows

Some material left behind

Slight turbidity

Slope failure into bite

Estimating ResidualsEstimating Residuals•• Residual mass balance Residual mass balance

using database of using database of completed projectscompleted projects–– Range of 2 to 9% by mass Range of 2 to 9% by mass

(Avg. 5%)(Avg. 5%)–– Residual conc. equal to Residual conc. equal to

average of sediment dredgedaverage of sediment dredged Residuals ≈

1.5 cm

Nepheloid ≈

3.5 cm

Turbid Water

Z-layer

Case Study Summary of Case Study Summary of Generated ResidualsGenerated Residuals

0%

1%

2%

3%

4%

5%

6%

7%

8%

9%

10%

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4

Average In-Situ Dry Density of Last Production Cut (gms/cm3)

Gen

erat

ed R

esid

ual (

% o

f las

t pro

duct

ion

cut)

Little Debris or Rock/Hardpan

Debris and/or Rock/Hardpan

Residual Management OptionsResidual Management Options

•• Monitored Natural RecoveryMonitored Natural Recovery•• Residuals Cap or Sand CoverResiduals Cap or Sand Cover•• Engineered Isolation CapEngineered Isolation Cap•• Additional Dredging (Production or Additional Dredging (Production or

Cleanup)Cleanup)

Decision Tree

Decision Tree ConsiderationsDecision Tree Considerations

•• Nature of residuals (undisturbed vs. Nature of residuals (undisturbed vs. generated)generated)

•• Characteristics of residuals (thickness, Characteristics of residuals (thickness, density, concentration)density, concentration)

•• Site conditionsSite conditions•• Environmental benefit and effectiveness of Environmental benefit and effectiveness of

additional dredgingadditional dredging

Low Cost In Situ TreatmentLow Cost In Situ Treatment

•• Activated Carbon AdditionActivated Carbon Addition–– Laboratory studies (Stanford, Univ. Maryland)Laboratory studies (Stanford, Univ. Maryland)–– FieldField--scale pilot studiesscale pilot studies

•• San Francisco Bay (CA)San Francisco Bay (CA)•• Grasse River (NY)Grasse River (NY)

–– Results to date very promisingResults to date very promising

•• Satisfies CERCLA preference for permanenceSatisfies CERCLA preference for permanence•• Engineering considerationsEngineering considerations•• Cost comparisonsCost comparisons

Activated Carbon Pilot Study AreaActivated Carbon Pilot Study Area

Activated Carbon Placement Techniques Roto-Tiller

Activated Carbon Placement Techniques Tine Sled

Field and Lab PCB Bioaccumulation Studies

Laboratory exposure test with L. variegatus

In-river deployment of field exposure cages with L. variegatus for baseline study

L. variegatus

Activated Carbon Pilot Study Activated Carbon Pilot Study –– Results to DateResults to Date

1. Activated carbon successfully delivered to sediments using a range of different methods

2. No construction water quality impacts

3. All of the activated carbon added in fall 2006 remained in sediments in fall 2007; declining spatial variability

4. Activated carbon bound most of the PCBs in surface sediments and rendered them unavailable to biota

5. Minor change in erosion potential of treated sediments

6. No measureable changes to benthic community

7. Additional work underway:• Follow-on testing in August 2008

• Potential applications to Grasse River sediment cleanup remedy

Sediment Delivery System Concept1. Agglomerate containing AC delivered from water surface2. Sinks to sediment surface and resists resuspension

3. Breaks down slowly3. Breaks down slowly

Water C

olumn

BiologicallyActive Zone

Deep

Sediment

Time

4. Mixed into sediment by bioturbation

Activated Carbon and Sand ApplicationActivated Carbon and Sand Application

55

Potential Activated Carbon ApplicationsPotential Activated Carbon Applications

1. Potential substitute for caps

2. Direct application to surface sediments• Typical unit cost < $50,000/acre

3. Incorporate activated carbon into cap

4. In situ treatment remedies supported by EPA guidance

Adaptive ManagementAdaptive Management

•• Grasse River Case StudyGrasse River Case Study–– Early source control and longEarly source control and long--term monitoringterm monitoring–– Pilot studies of dredging, capping, and in situ Pilot studies of dredging, capping, and in situ

treatment technologiestreatment technologies

•• Fox River Case StudyFox River Case Study–– New data drove ROD AmendmentNew data drove ROD Amendment–– Combined dredging and capping remedyCombined dredging and capping remedy–– Value engineering and cost reductionValue engineering and cost reduction