Sheen Characterization 2009 Data and Observations July 2010 Progress Meeting McCormick & Baxter Superfund Site Portland, Oregon

Sheen Characterization Presentation Objectives – Identify Nature of Sheen Previous Investigations Summary 2009 Sheen Characterization Activities and Results –Chemical –Biological (Dr. Anne Camper) Conclusions and Recommendations –Shallow contour maps –Hydrographs –Gradients

2007 Sheen Investigations Focused on area surrounding large Reactive Core Mat and shoreline in the TFA – June Time-series sampling in September

2008 Sheen Investigations Sheen with water, adjacent surface water, and sediment with sheen were collected from 4 locations along the shoreline Concentrations of low molecular weight similar to those in surface water were detected in the sheen with water Sheen appeared blocky and iridescent in appearance; did not re- coalesce upon probing

2008 Investigation Tasks SPME, sediment cores, and porewater samples 10 co-located flux chamber samples Biodegradation study on cores Survey of locations and rates of ebullition through tidal cycle and season Continued shoreline documentation of sheen Sampling of sheen (July 2008)

Sampling Locations

Overall Conclusions 2008 Organoclay retains its full sorption capacity – both OC mats and granular Permeability remains near fresh organoclay (similar to sand) HEM fraction higher in ET-1 – likely reason for enhanced microbial activity in bulk granular organoclay Porewater concentrations generally below comparison criteria No evidence that sheens are caused by creosote migrating from beneath the cap

Overall Conclusions 2008 (cont.) Sediment concentrations in cap below cleanup goals Sheen concentrations comparable to ambient surface water Ebullition is a pathway for contamination – however, below comparison criteria with exception of low level cPAHs thought to be particulate matter Sheen origin remains unknown

2010 Characterization Activities Shoreline Sheen Observations Sheen Simulation with Site Product Sheen Sampling –Chemistry –Biological

Sheen Simulation Method with pipette and pan Sheen was sampled similarly to the field sampling – by passing a Teflon® net and pad through the sheen (ASTM D4489)

More Photos

Sheen Sampling Methods Sheen –Teflon nets and pads (ASTM 4489)- used to collect sheen samples from surface water. Each pad/net used daily at same location for four days to obtain sufficient sheen on pad/net. –C-18 cartridges – know volume of sheen with water was pumped through C-18 cartridge. Ambient Water – peristaltic pump Samples sent to Pace for Analytical and Dr. Anne Camper/MSU for biological analysis

Sampling Locations

Chromatograms 25,000  g Total PAHs <0.59  g Total PAHs  g Total PAHs Simulated Sheen Actual Site Sheen - TFA Blank Net

Analytical Results Teflon® Net/Pad Iron/Mg was concentrated in sheen (54X - sheen/9X - water) PAHs were not detected in sheen (exception: fluorene was estimated in 2 samples) C-18 Method Method comparable for water and sheen PAHs (acenaphthene, acenaphthylene, fluorene, and naphthalene) detected at slightly higher concentrations in water than in sheen samples.

Chemistry Conclusions Collection method robust Chromatograms demonstrate sheen is very different from a site product sheen Iron concentration in sheen (in creosote sheen – chromium is the highest concentration metal -0.11XMg) PAH concentrations detected with C-18 cartridge reflective of water concentrations (nets and pads will not sorb dissolved PAHs from water)

Microbiology Methods Samples of parallel water and mesh Heterotrophic plate counts Extracted DNA and population analysis Microscopy

Heterotrophic Plate Counts Water counts from 10^4 to 10^5/ml Mesh counts from 10^6 to 10^8/mesh Sheen had associated bacteria No major difference between two samplings No differences in colony morphologies

Denaturing Gradient Gel Electrophoresis Targeted 16S rDNA Each band ~ one species No substantial differences TFA Water Mesh

Microscopy Staining methods to determine if sheen was created/stabilized by bacteria Emphasis on morphologies typical of iron oxidizing bacteria Mesh samples inconclusive for bacteria; sheen not formed by bacterial biofilms or iron bacteria

Overall Conclusions-Sheen Characterization 2009 characterization work support the previous sheen sampling results, porewater sampling results, and core sampling results from 2007 and 2008 General shoreline sheen in late summer/early fall are not due to sheen migrating through the sediment cap Sheen appears to be a non-biological iron concentration