Kalinovich, I., Thalheimer. A.H., Loney, B.
Perfluorinated-carbon tail hydrophobic interactions Functional group head electrostatic interactions PFAS = Per- and polyfluorinated alkyl substances
Sites Impacted by PFASs Landfills; Semi-conductor industry; Hydraulic fluids (Aviation Industry); Firefighting using AFFF; AFFF used to put out fuel/hydrocarbon fires. Oil Well Fire, United States Marine Corps, 2003.
Fighting fire with Foam Applicator (Sontake and Wagh, 2014).
Perfluorooctane Sulfonate (PFOS) Low volatility. Generally in ionized form. Hydrophobic tail, functional group head. PFOS from AFFF (aqueous film forming foam) in a mixtures of PFAS. Due to its dual nature, prefers interfaces (air/water, particle/water).
Geochemical Concentrations observed in bedrock (fractured) Elevated concentrations at surface (potential for HH risks, leaching) Elevated concentrations at greater depths On-going source (e.g. unlined lagoon) PHC co-contaminants present High f oc (increased sorption) Particle reactivity (mineral surfaces - increased sorption) Decreased salinity (decreases sorption/increases PFOS solubility) Increased ph (decreases sorption/increases PFOS solubility) Physical Large water table fluctuation (larger smear zone) Greater groundwater flow Greater infiltration Large particle size (if high concentrations leaching) Small particle size (silt - increased sorption diffusive release) Small particle size (clay - increased sorption) Zhao et al., 2014. Chemosphere, 114:51-8 Ferrey et al. 2012, Ground Water Monitoring & Remediation, 32 (4):63 71 Higgins and Luthy, 2006, Environmental Science & Technology 40 (23): 7251-7256.
PFOS in Soil PFOS
PFOS PFOS in Groundwater
PFOS PHCs
Coarse-textured glaciolacustrine deposits consisting of sand, gravel, silt and clay. Sands, silts and gravels overlying massive clay unit. Soil f oc < 500 mg/kg. Soil ph (7.3 8).
Multiple Primary and Secondary Sources; Multiple Investigations since 1990s; Surface water receptor to the west of the site.
P r e s e n t a t i o n T i t l e H e r e 12
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14 Unlined facilities replaced in 1990s; Still used as FFTA (managed discharge); Has resulted in several hydrocarbon plumes, that have since almost all but been attenuated. Current data sets: limited hydrocarbon impacts in soil; limited PAH impacts in soil, limited metals in soil = LOW SORPTION TO SOILS
BH007 BH021 BH023 BH009 BH016 BH013 BH012 BH017 BH013 BH015 BH008 BH022 BH026 BH027 BH026 BH027 BH027 BH015 BH016 BH025 BH025 Concentrations as Percentages PFOS 100% 80% 60% 40% 20% PFUnA PFPeA PFOS PFOSA PFNA PFOA PFHxA PFHxS PFHpA PFDoA PFDA Perfluorobutanoic acid 0%
BH021 BH023 BH009 BH016 BH013 BH012 BH017 BH013 BH015 BH008 BH007 BH022 BH026 BH027 BH026 BH027 BH027 BH015 BH016 BH025 BH025 Concentration in ug/kg 100000 10000 > 8 mbgs 1000 100 10 1 0.1 PFUnA PFPeA PFOS PFOSA PFNA PFOA PFHxA PFHxS PFHpA PFDoA PFDA Perfluorobutanoic acid Increasing Soil Depth
BH026 BH026 BH027 BH027 BH027 BH025 BH025 BH022 BH023 BH021 BH017 BH016 BH016 BH015 BH015 BH013 BH013 BH012 BH007 BH009 BH008 Concentration in ug/kg Only location we have hit for PHCs (F1=2500, 100000 F2= 3300 mg/kg) 10000 1000 100 10 1 0.1 PFUnA PFPeA PFOS PFOSA PFNA PFOA PFHxA PFHxS PFHpA PFDoA PFDA Perfluorobutanoic acid Upgradient to Downgradient
Concentration (ug/l) 1600 1400 1200 Wells that have elevated concentrations have screens across smear zone /near water table. PFUnA PFPeA PFOS PFOSA PFNA 1000 800 600 400 200 PFOA PFHxA PFHxS PFHpA PFDoA PFDA Perfluorobutanoic acid PFBS 0
Concentration (ug/l) 12 10 PFUnA PFPeA PFOS PFOSA Monitoring Well near Creek 8 6 4 2 PFNA PFOA PFHxA PFHxS PFHpA PFDoA PFDA Perfluorobutanoic Acid 0 background upgradient midgradient midgradient FD downgradient downgradient FD
Concentration (ug/l) 12 70 PFUnA 10 60 PFPeA PFOS 8 6 50 40 30 PFOSA PFNA PFOA PFHxA 4 20 PFHxS PFHpA 2 10 PFDoA 0 0 PFDA Perfluorobutanoic Acid
Minimal soil sorption no f oc, no mineral surfaces. Coats particles solid/liquid interface We see from the groundwater data that PFASs are mainly near the water table liquid/air interface. Indicates geochemical influences on transport.
BTEX PFBS PFBA PFHpA PFHxS PFHxA PFOA PFNA PFOSA PFOS PFPeA <0.025 No 0.16 statistical 0.63 correlations 0.57 2 unless we 2 group 0.24 by order <0.02 of <0.02 2 2 <0.025 <0.02 <0.02 <0.02 0.03 0.03 <0.02 <0.02 <0.02 <0.02 0.02 <0.025 magnitude. 0.02 0.30 0.17 0.74 0.79 0.15 <0.02 <0.02 0.30 1 4.6 12 11 8 120 60 18 0.39 3 170 25 4.9 Data 12 strongly 11 indicates 8 that 120 BTEX 60 can be used 18 an indicators 0.39 3 170 25 <0.025 19 44 29 180 290 27 0.17 0.06 71 110 <0.025 this 0.10 is how 0.14we selected 0.11 which 0.92 well 0.82 locations 0.29 to test <0.02 for PFOS. 0.68 4 0.37 0.038 6 37 18 62 190 21 <1 5 290 95 <0.025 Discrepancies 0.07 0.62 with 0.56that theory 4 noted 3 in two 0.61locations. 0.05 Other 2 5 3 <0.025 explanations? 0.10 1 2 7 4 2 0.12 0.24 48 5 <0.025 0.64 0.56 0.51 6 2 0.48 <0.02 6 9 2 <0.025 0.35One location 0.51 near 0.50 AFFF storage 5 area; 2 0.42 <0.02 6 8 2 3.6 0.86 2 2 19 7 5 1 5 540 5 1.2 3 On road/turn 10 around 10 area near 66 burn 58 pits potential 17 spill? 1 1 1300 29 0.13 18 18 12 230 110 31 0.59 2 440 44 <0.025 0.05 0.14 0.26 1 0.28 0.14 <0.02 <0.02 0.07 0.31 <0.025 0.04 0.14 0.27 1.2 0.29 0.17 <0.02 <0.02 0.06 0.33 <0.025 BTEX 0.04in mg/l, all PFAS 0.16concentrations 0.33 in ug/l 1 0.25 0.15 <0.02 <0.02 0.23 0.36
23 Location Potential Receptors Preliminary Estimate of Risk Soil Human receptors Terrestrial ecological receptors Aquatic ecological receptors Moderate Moderate Moderate Groundwater Human receptors Terrestrial ecological receptors Aquatic ecological receptors Low Low Moderate Surface Water Human receptors Terrestrial ecological receptors Aquatic ecological receptors Moderate/High Low Moderate/High
24 Sites with firefighting activities looking for PFASs should consider co-contaminant canaries. e.g. PHCs can be used as indicators for locating elevated concentrations of PFOS. Fate and transport mechanisms for PFAS are complex. Dependent on soil and groundwater geochemistry Look for sorption sites, colloidal particles and interfaces.
Kalinovich, I., Thalheimer. A.H., Loney, B. Questions? ikalinovich@dillon.ca