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23 rd Annual NARPM Training Program Passive Sampling Case Study: United Heckathorn Superfund Site Rachelle S. Thompson, MS, PE US EPA Region 9
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23 rd Annual NARPM Training Program 1 Presentation Outline Site location and background Past remedial actions Current conditions Feasibility study Passive sampler deployments Preliminary results Next steps
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23 rd Annual NARPM Training Program 2 United Heckathorn Superfund Site
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23 rd Annual NARPM Training Program 3 Site Location
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23 rd Annual NARPM Training Program 4 Cleanup History Initial response (1990-1998) 3,300 cubic yards of DDT-contaminated soil removed from upland area Dredged 107,000 cubic yards of contaminated sediment (3 tons DDT) from Lauritzen Channel and Parr Canal Capped upland area with concrete to prevent erosion Monitoring and additional investigations Sampling of fish, mussels, sediment, and water Five Year Reviews in 2001, 2006, and 2011
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23 rd Annual NARPM Training Program 5 Current Status The upland cap remains intact and protective. DDT levels in the Inner Richmond Harbor, Santa Fe Channel and Parr Canal have decreased significantly. DDT levels in Lauritzen Channel pose a potential long- term risk to human health through consumption of fish. DDT levels in Lauritzen Channel pose a potential ecological risk to fish-eating birds and mammals.
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23 rd Annual NARPM Training Program 6 Mussel Trends
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23 rd Annual NARPM Training Program 7 Feasibility Study Tier 1 Sediment Study Tier 2 Sediment Study Source Identification Study DDT Fate & Transport Study
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23 rd Annual NARPM Training Program 8 Tier 1 Sediment Study Multi-beam and side- scan sonar create images of the channel bottom Areas of deposition and erosion of sediment Natural and anthropogenic forces
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23 rd Annual NARPM Training Program 9 Tier 2 Sediment Study Current and turbidity monitoring Particle tracking Sediment erosion analysis Sediment transport modeling
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23 rd Annual NARPM Training Program 10 Source Identification Study Groundwater Embankments and seeps Pilings Undredged sediments Other sources
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23 rd Annual NARPM Training Program 11 DDT Fate & Transport Study Passive samplers Sediment cores Trends Sources and sinks Approximately 66,000 yd 3 of contaminated sediment in Lauritzen Channel Approximately 350 kg of DDT in those sediments
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23 rd Annual NARPM Training Program 12 Passive Sampling Goals Evaluate spatial distribution of contamination Evaluate contaminant fate & transport and potential sources Evaluate long-term monitoring options
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23 rd Annual NARPM Training Program 13 Types of Passive Samplers Sediment: Polyethylene mounted in metal frame Surface water: Polyethylene strips in mesh bag, co- deployed with mussels
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23 rd Annual NARPM Training Program 14 Sampling Locations Sediment locations: 2012 (purple) and 2013 (green) Water locations (additional background point not shown)
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23 rd Annual NARPM Training Program 15 Deployment and Recovery September-October 2013 ERT dive team support for sediment samplers Surface water samplers deployed from boat
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23 rd Annual NARPM Training Program 16 targetPRCs target at time = 0 C pe = 0 for targets at some later time, t measure PRC losses and C pe (t) use results to find C pe (t = ∞) Performance Reference Compounds Laboratory method: Gshwend, P. et al, Passive PE Sampling in Support of In Situ Remediation of Contaminated Sediments: Standard Operating Procedure for PED Preparation, December 2012.
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23 rd Annual NARPM Training Program 17 Field Challenges Shutdown Boat logistics Poor visibility Channel depth Active channel
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23 rd Annual NARPM Training Program 18 4,4’-DDD, 4,4’-DDT, and 4,4’-DDE with depth into bed (ng/g PE) DDD dominant 4,4’-DDD 4,4’- DDE 4,4’- DDT Vertical Chemical Profiles
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23 rd Annual NARPM Training Program 19 Spatial Distribution Bottom water and pore water concentrations (ng/L 4,4’-DDD) Strong gradient down channel Every channel station has porewater > bottomwater Bed-to-water column fluxes
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23 rd Annual NARPM Training Program 20 Simple Mass Balance Estimate
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23 rd Annual NARPM Training Program 21 Site Monitoring- 2012
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23 rd Annual NARPM Training Program 22 Site Monitoring- 2013
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23 rd Annual NARPM Training Program 23 Surface Water Filtered water PE-inferred water concentration Mussel- inferred water concentration
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23 rd Annual NARPM Training Program 24 Preliminary Conclusions Porewater DDx concentrations are highest in the northern reach of the channel There is a high degree of uncertainty in the mass balance modeling, but there appears to be an ongoing source mid- channel Water-column passive samplers could potentially be used for long-term monitoring at the site
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23 rd Annual NARPM Training Program 25 Next Steps
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23 rd Annual NARPM Training Program 26 Acknowledgements CH2MHILL- Brenda McConathy, Patricia White E2- Tamara Frank EPA Region 9 Lab- Andy Lincoff ERT Dive Team – Steve Blaze, Alan Humphrey, Scott Grossman, Chris Gallo, John McBurney Massachusetts Institute of Technology- Phil Gshwend, Patricia Tcaciuc Sea Engineering Inc.- Craig Jones US Army Corps of Engineers- Karl Gustavson, Earl Hayter
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23 rd Annual NARPM Training Program 27 Questions? Additional information epa.gov/region09/unitedheckathorn Contact information Rachelle S. Thompson, MS, PE Superfund Division US EPA Region 9 75 Hawthorne Street, SFD-7-3 San Francisco, CA 94105 415-972-3962 thompson.rachelle@epa.gov
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