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LaFond JA, Rezes R, Shojaei M, Anderson T, Jackson WA, Guelfo JL, Hatzinger PB. Biotransformation of PFAA Precursors by Oxygenase-Expressing Bacteria in AFFF-Impacted Groundwater and in Pure-Compound Studies with 6:2 FTS and EtFOSE. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:13820-13832. [PMID: 39038214 DOI: 10.1021/acs.est.4c01931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/24/2024]
Abstract
Numerous US drinking water aquifers have been contaminated with per- and polyfluoroalkyl substances (PFAS) from fire-fighting and fire-training activities using aqueous film-forming foam (AFFF). These sites often contain other organic compounds, such as fuel hydrocarbons and methane, which may serve as primary substrates for cometabolic (i.e., nongrowth-linked) biotransformation reactions. This work investigates the abilities of AFFF site relevant bacteria (methanotrophs, propanotrophs, octane, pentane, isobutane, toluene, and ammonia oxidizers), known to express oxygenase enzymes when degrading their primary substrates, to biotransform perfluoroalkyl acid (PFAA) precursors to terminal PFAAs. Microcosms containing AFFF-impacted groundwater, 6:2 fluorotelomer sulfonate (6:2 FTS), or N-ethylperfluorooctane sulfonamidoethanol (EtFOSE) were inoculated with the aerobic cultures above and incubated for 4 and 8 weeks at 22 °C. Bottles were sacrificed, extracted, and subjected to target, nontarget, and suspect screening for PFAS. The PFAA precursors 6:2 FTS, N-sulfopropyldimethyl ammoniopropyl perfluorohexane sulfonamide (SPrAmPr-FHxSA), and EtFOSE transformed up to 99, 71, and 93%, respectively, and relevant daughter products, such as the 6:1 fluorotelomer ketone sulfonate (6:1 FTKS), were identified in quantities previously not observed, implicating oxygenase enzymes. This is the first report of a suite of site relevant PFAA precursors being transformed in AFFF-impacted groundwater by bacteria grown on substrates known to induce specific oxygenase enzymes. The data provide crucial insights into the microbial transformation of these compounds in the subsurface.
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Affiliation(s)
- Jessica A LaFond
- Department of Civil, Environmental & Construction Engineering, Texas Tech University, Lubbock, Texas 79409, United States
| | - Rachael Rezes
- Biotechnology Development & Applications Group, APTIM, Lawrenceville, New Jersey 08648, United States
| | - Marzieh Shojaei
- Department of Civil & Environmental Engineering, Duke University, Durham, North Carolina 27710, United States
| | - Todd Anderson
- The Institute of Environmental and Human Health, Texas Tech University, Lubbock, Texas 79409, United States
| | - W Andrew Jackson
- Department of Civil, Environmental & Construction Engineering, Texas Tech University, Lubbock, Texas 79409, United States
| | - Jennifer L Guelfo
- Department of Civil, Environmental & Construction Engineering, Texas Tech University, Lubbock, Texas 79409, United States
| | - Paul B Hatzinger
- Biotechnology Development & Applications Group, APTIM, Lawrenceville, New Jersey 08648, United States
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2
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Cook E, Olivares CI, Antell EH, Tsou K, Kim TK, Cuthbertson A, Higgins CP, Sedlak DL, Alvarez-Cohen L. Sulfonamide Per- and Polyfluoroalkyl Substances Can Impact Microorganisms Used in Aromatic Hydrocarbon and Trichloroethene Bioremediation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:8792-8802. [PMID: 38719742 PMCID: PMC11112735 DOI: 10.1021/acs.est.3c09715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 04/10/2024] [Accepted: 04/11/2024] [Indexed: 05/22/2024]
Abstract
Per- and polyfluoroalkyl substances (PFASs) from aqueous film forming foams (AFFFs) can hinder bioremediation of co-contaminants such as trichloroethene (TCE) and benzene, toluene, ethylbenzene, and xylene (BTEX). Anaerobic dechlorination can require bioaugmentation of Dehalococcoides, and for BTEX, oxygen is often sparged to stimulate in situ aerobic biodegradation. We tested PFAS inhibition to TCE and BTEX bioremediation by exposing an anaerobic TCE-dechlorinating coculture, an aerobic BTEX-degrading enrichment culture, and an anaerobic toluene-degrading enrichment culture to n-dimethyl perfluorohexane sulfonamido amine (AmPr-FHxSA), perfluorohexane sulfonamide (FHxSA), perfluorohexanesulfonic acid (PFHxS), or nonfluorinated surfactant sodium dodecyl sulfate (SDS). The anaerobic TCE-dechlorinating coculture was resistant to individual PFAS exposures but was inhibited by >1000× diluted AFFF. FHxSA and AmPr-FHxSA inhibited the aerobic BTEX-degrading enrichment. The anaerobic toluene-degrading enrichment was not inhibited by AFFF or individual PFASs. Increases in amino acids in the anaerobic TCE-dechlorinating coculture compared to the control indicated stress response, whereas the BTEX culture exhibited lower concentrations of all amino acids upon exposure to most surfactants (both fluorinated and nonfluorinated) compared to the control. These data suggest the main mechanisms of microbial toxicity are related to interactions with cell membrane synthesis as well as protein stress signaling.
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Affiliation(s)
- Emily
K. Cook
- Department
of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
| | - Christopher I. Olivares
- Department
of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
- Department
of Civil and Environmental Engineering, University of California, Irvine, California 92697, United States
| | - Edmund H. Antell
- Department
of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
| | - Katerina Tsou
- Department
of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
| | - Tae-Kyoung Kim
- Department
of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
| | - Amy Cuthbertson
- Department
of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
| | - Christopher P. Higgins
- Department
of Civil & Environmental Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
| | - David L. Sedlak
- Department
of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
| | - Lisa Alvarez-Cohen
- Department
of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
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3
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Gonda N, Choyke S, Schaefer C, Higgins CP, Voelker B. Hydroxyl Radical Transformations of Perfluoroalkyl Acid (PFAA) Precursors in Aqueous Film Forming Foams (AFFFs). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:8053-8064. [PMID: 37200532 DOI: 10.1021/acs.est.2c08689] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Historical releases of aqueous film forming foam (AFFF) are significant sources of poly- and perfluoroalkyl substances (PFASs), including perfluoroalkyl acids (PFAAs) and their precursors, to the environment. While several studies have focused on microbial biotransformation of polyfluorinated precursors to PFAAs, the role of abiotic transformations at AFFF-impacted sites is less clear. Herein, we use photochemically generated hydroxyl radical to demonstrate that environmentally relevant concentrations of hydroxyl radical (•OH) can play a significant role in these transformations. High-resolution mass spectrometry (HRMS) was used to perform targeted analysis, suspect screening, and nontargeted analyses, which were used to identify the major products of AFFF-derived PFASs as perfluorocarboxylic acids, though several potentially semi-stable intermediates were also observed. Using competition kinetics in a UV/H2O2 system, hydroxyl radical rate constants (kOH) for 24 AFFF-derived polyfluoroalkyl precursors were measured to be 0.28 to 3.4 × 109 M-1 s-1. Differences in kOH were observed for compounds with differing headgroups and perfluoroalkyl chain lengths. Also, differences in kOH measured for the only relevant precursor standard available, n-[3-propyl]tridecafluorohexanesulphonamide (AmPr-FHxSA), as compared to AmPr-FHxSA present in AFFF suggest that intermolecular associations in the AFFF matrix may affect kOH. Considering environmentally relevant [•OH]ss, polyfluoroalkyl precursors are expected to exhibit half-lives of ∼8 days in sunlit surface waters and possibly as short as ∼2 h during oxygenation of Fe(II)-rich subsurface systems.
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Affiliation(s)
- Nicholas Gonda
- Department of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Sarah Choyke
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
| | | | - Christopher P Higgins
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Bettina Voelker
- Department of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
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4
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Lewis AJ, Ebrahimi F, McKenzie ER, Suri R, Sales CM. Influence of microbial weathering on the partitioning of per- and polyfluoroalkyl substances (PFAS) in biosolids. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2023; 25:415-431. [PMID: 36637091 DOI: 10.1039/d2em00350c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are a large group of man-made fluorinated organic chemicals that can accumulate in the environment. In water resource recovery facilities (WRRFs), some commonly detected PFAS tend to partition to and concentrate in biosolids where they can act as a source to ecological receptors and may leach to groundwater when land-applied. Although biosolids undergo some stabilization to reduce pathogens before land application, they still contain many microorganisms, contributing to the eventual decomposition of different components of the biosolids. This work demonstrates ways in which microbial weathering can influence biosolids decomposition, degrade PFAS, and impact PFAS partitioning in small-scale, controlled laboratory experiments. In the microbial weathering experiments, compound-specific PFAS biosolids-water partitioning coefficients (Kd) were demonstrated to decrease, on average, 0.4 logs over the course of the 91 day study, with the most rapid changes occurring during the first 10 days. Additionally, the highest rates of lipid, protein, and organic matter removal occurred during the same time. Among the evaluated independent variables, statistical analyses demonstrated that the most significant solids characteristics that impacted PFAS partitioning were organic matter, proteins, lipids, and molecular weight of organics. A multiple linear regression model was built to predict PFAS partitioning behavior in biosolids based on solid characteristics of the biosolids and PFAS characteristics with a R2 value of 0.7391 when plotting predicted and measured log Kd. The findings from this work reveal that microbial weathering can play a significant role in the eventual fate and transport of PFAS and their precursors from biosolids.
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Affiliation(s)
- Asa J Lewis
- Department of Civil, Architectural, and Environmental Engineering, Drexel University, 3100 Market St., Philadelphia, PA, 19104, USA.
| | - Farshad Ebrahimi
- Department of Civil and Environmental Engineering, Temple University, 1947 N 12th St., Philadelphia, PA, 19122, USA
| | - Erica R McKenzie
- Department of Civil and Environmental Engineering, Temple University, 1947 N 12th St., Philadelphia, PA, 19122, USA
| | - Rominder Suri
- Department of Civil and Environmental Engineering, Temple University, 1947 N 12th St., Philadelphia, PA, 19122, USA
| | - Christopher M Sales
- Department of Civil, Architectural, and Environmental Engineering, Drexel University, 3100 Market St., Philadelphia, PA, 19104, USA.
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5
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Nickerson A, Maizel AC, Schaefer CE, Ranville JF, Higgins CP. Effect of geochemical conditions on PFAS release from AFFF-impacted saturated soil columns. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2023; 25:405-414. [PMID: 36629138 DOI: 10.1039/d2em00367h] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs) are frequently found at high concentrations in the subsurface of aqueous film forming foam (AFFF)-impacted sites. Geochemical parameters affect the release of PFASs from source area soils into groundwater but have not been extensively studied for soils that have been historically impacted with AFFF. This study investigated the effects of pH and salt concentrations on release of anionic and zwitterionic PFASs from AFFF-impacted soils in flow-through saturated columns. High pH (10) columns with elevated sodium concentrations had higher cumulative masses eluted of several PFASs compared to pH 3 and pH 7 columns with lower sodium concentrations, likely caused by changes to soil organic matter surface charge. Four PFASs (e.g. 4:2 fluorotelomer sulfonate, perfluorobutane sulfonamido acetic acid) eluted significantly earlier in both pH 3 and pH 10/high NaCl columns compared to pH 7 columns. The results of this study suggest that shifts in pH for soils located at AFFF-impacted sites - particularly raising the pH - may mobilize sorbed PFASs, specifically longer-chain and zwitterionic compounds that are typically strongly sorbed to soil.
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Affiliation(s)
- Anastasia Nickerson
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado 80401, USA.
| | - Andrew C Maizel
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado 80401, USA.
| | | | - James F Ranville
- Department of Chemistry, Colorado School of Mines, Golden, Colorado 80401, USA
| | - Christopher P Higgins
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado 80401, USA.
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6
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Schaefer CE, Lavorgna GM, Lippincott DR, Nguyen D, Schaum A, Higgins CP, Field J. Leaching of Perfluoroalkyl Acids during Unsaturated Zone Flushing at a Field Site Impacted with Aqueous Film Forming Foam. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:1940-1948. [PMID: 36689630 DOI: 10.1021/acs.est.2c06903] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
While several studies have focused on perfluoroalkyl acid (PFAA) leaching from soils, field studies evaluating the relationship between PFAA mass removal and porewater concentrations as the PFAA source becomes depleted are lacking. Herein, in situ water flushing was performed at a site historically impacted with AFFF to accelerate the leaching of PFAAs from unsaturated soils in a highly characterized field test cell. Porous cup suction lysimeters were used to assess the changes in PFAA porewater concentrations as a function of PFAA mass removal from the unsaturated soils, where flushing was intermittently paused to determine ambient PFAA porewater concentrations. Results showed that the fractional decreases in PFAA porewater concentrations during flushing exceeded the fractional decrease in PFAA mass removal from the soil. PFOS porewater concentrations decrease by 76% (with negligible rebound) compared to only a 7.4% decrease in overall PFOS mass removed from the unsaturated zone. Overall, the results observed herein suggest that, when considering soil impacts to groundwater, less stringent soil cleanup criteria than those that consider an equivalent relationship between mass removal and mass discharge may be appropriate. In addition, remedial approaches that remove only a modest fraction of the PFAA soil mass may be protective of underlying groundwater, particularly for perfluorinated sulfonates with at least six carbons.
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Affiliation(s)
- Charles E Schaefer
- CDM Smith, 110 Fieldcrest Avenue, #8, 6th Floor, Edison, New Jersey08837, United States
| | - Graig M Lavorgna
- APTIM Federal Services, 17 Princess Rd, Lawrenceville, New Jersey08648, United States
| | - David R Lippincott
- APTIM Federal Services, 17 Princess Rd, Lawrenceville, New Jersey08648, United States
| | - Dung Nguyen
- CDM Smith, 14432 SE Eastgate Way, # 100, Bellevue, Washington98007, United States
| | - Andre Schaum
- Department of Molecular and Environmental Toxicology, Oregon State University, 1007 Agricultural and Life Science Building, Corvallis, Oregon97331, United States
| | - Christopher P Higgins
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado80401, United States
| | - Jennifer Field
- Department of Molecular and Environmental Toxicology, Oregon State University, 1007 Agricultural and Life Science Building, Corvallis, Oregon97331, United States
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7
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Shojaei M, Kumar N, Guelfo JL. An Integrated Approach for Determination of Total Per- and Polyfluoroalkyl Substances (PFAS). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:14517-14527. [PMID: 36197695 DOI: 10.1021/acs.est.2c05143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are difficult to analyze in environmental media due challenges such as extraction recovery and lack of analytical standards. The total oxidizable precursor (TOP) assay and suspect screening analysis coupled with semiquantitative (SQ) concentration estimates are two approaches to assess total PFAS in environmental media, but studies are needed to optimize workstreams for total PFAS analysis. This study applied two soil extraction methods, TOP assay, and SQ analysis to three aqueous film-forming foams (AFFFs) and three AFFF-impacted soils. In soils, the total PFAS estimated with results from an extraction method utilizing sequential acidic and basic solvents led to a 35% increase in precursors during TOP assay relative to results from a basic solvent only extraction in one of three soils tested, but concentrations did not increase significantly in remaining soils. Furthermore, sample-specific dilution schemes were required to overcome matrix effects caused by the acidic extraction step that influenced estimates of total PFAS by SQ analysis. The results highlight that there is not an advantage to routine application of an acid extraction step in PFAS-impacted soils. In three AFFFs, suspect screening of post-TOP samples identified eight classes of PFAS present after oxidation. Concentrations of three classes increased, suggesting they are new TOP end points. Concentrations of the remaining five classes either remained constant after TOP or exhibited slight decreases. As a result, combined TOP and SQ workstreams may yield the most representative assessment of total PFAS composition and concentration. The eight classes of PFAS present after TOP did not degrade in harsh conditions. Some are structurally similar to PFCAs and PFSAs and are known to occur in the environment, suggesting a similar degree of persistence and a need for more routine monitoring.
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Affiliation(s)
- Marzieh Shojaei
- Department of Civil, Environmental, & Construction Engineering, Texas Tech University, Lubbock, Texas79409, United States
| | - Naveen Kumar
- Department of Civil, Environmental, & Construction Engineering, Texas Tech University, Lubbock, Texas79409, United States
| | - Jennifer L Guelfo
- Department of Civil, Environmental, & Construction Engineering, Texas Tech University, Lubbock, Texas79409, United States
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8
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Choi YJ, Helbling DE, Liu J, Olivares CI, Higgins CP. Microbial biotransformation of aqueous film-forming foam derived polyfluoroalkyl substances. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 824:153711. [PMID: 35149076 DOI: 10.1016/j.scitotenv.2022.153711] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 02/02/2022] [Accepted: 02/02/2022] [Indexed: 06/14/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs) used in aqueous film-forming foam (AFFF) comprise some perfluoroalkyl substances but a larger variety of polyfluoroalkyl substances. Despite their abundance in AFFF, information is lacking on the potential transformation of these polyfluoroalkyl substances. Due to the biological and chemical stability of the repeating perfluoroalkyl -(CF2)n- moiety common to all known AFFF-derived PFASs, it is not immediately evident whether the microbial biotransformation mechanisms observed for other organic contaminants also govern the microbial biotransformation of polyfluoroalkyl substances. Herein, we aim to: 1) review the literature on the aerobic or anaerobic microbial biotransformation of AFFF-derived polyfluoroalkyl substances in environmental media; 2) compile and summarize proposed microbial biotransformation pathways for major classes of polyfluoroalkyl substances; 3) identify the dominant biotransformation intermediates and terminal biotransformation products; and 4) discuss these findings in the context of environmental monitoring and source allocation. This analysis revealed that much more is currently known about aerobic microbial biotransformation of polyfluoroalkyl substances, as compared to anaerobic biotransformation. Further, there are some similarities in microbial biotransformations of fluorotelomer and electrochemical fluorination-derived polyfluoroalkyl substances, but differences may be largely due to head group composition. Dealkylation, oxidation, and hydrolytic reactions appear to be particularly important for microbial biotransformation of AFFF-derived polyfluoroalkyl substances, and these biotransformations may lead to formation of some semi-stable intermediates. Finally, this review discusses key knowledge gaps and opportunities for further research.
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Affiliation(s)
- Youn Jeong Choi
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO, USA; Department of Agronomy, Purdue University, West Lafayette, IN, USA
| | - Damian E Helbling
- School of Civil and Environmental Engineering, Cornell University, Ithaca, NY, USA
| | - Jinxia Liu
- Department of Civil Engineering, McGill University, Montreal, Quebec, Canada
| | - Christopher I Olivares
- Department of Civil and Environmental Engineering, University of California, Irvine, CA, USA
| | - Christopher P Higgins
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO, USA.
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