Session 9: PFAS and Emerging Contaminants

All-Day Session

* 4 credits are available for this session through APA AICP
* Four presentations in this session have been approved for training contact hours (TCH) through the State of Maine Board of Licensure of Water System Operators. Please see below for details.
* This session have been approved for 4 training contact hours (TCH) through Maine’s Wastewater Operator Certification Program.

Co-Chairs: Charlie Culbertson, U.S. Geological Survey; Jason Sorenson, U.S. Geological Survey

Per- and Polyfluoroalkyl Substances include a wide range of compounds that have been used in a wide range of domestic and industrial applications since the 1950. They are very persistent in the environment, highly mobile, bioaccumulate and have been linked to several negative health outcomes such as immunotoxicity and cancer. Other contaminants that are poorly understood include compounds associated with wastewater effluent such as pharmaceuticals and personal healthcare products (PPHCPs) and endocrine disruptors. Microplastics and nanoparticles are examples of other two other groups of ‘emerging’ contaminants. These substances represent a large and diverse group of pollutants that urgently require more work to refine analytical methods, quantify sources, develop transport models, and a better understanding of human and ecological health risk and exposure pathways.

Session Schedule

Morning Session

Afternoon Session

Reception

  • 3:30PM-4:30pm – Main Auditorium
    Poster and exhibit viewing. Light refreshments.

* Presenters are indicated in bold font

Morning Session

8:30AM-8:55AM
USGS Cooperative Studies and Other National Research Initiatives to Study PFAS, Microplastics, and Other Emerging Contaminants

Approved for 0.5 TCH

Charlie Culbertson, Jason Sorenson
U.S. Geological Survey, Augusta, ME

The U.S. Geological Survey’s cooperative studies program provides a unique opportunity that mandates USGS Water Science Centers develop partnerships with Tribal groups, State and local agencies, academic institutions, and other public and private organizations to collaborate and address critical issues facing the Nation’s water resources. Several case studies of past and current cooperative research initiatives focused on per/polyfluoralkyl substances (PFAS), microplastics, pharmaceuticals and personal health care products (PPHCPs) in the northeastern United States will be discussed. National initiatives by the USGS and other Federal partners to help determine the risks to human health and aquatic life from these substances, as well and potential mitigation approaches will also be introduced.

9:00AM-9:25AM
Dealing with the PFAS Legacy in Maine

Approved for 0.5 TCH

Normand R. Labbe, PE
Former Superintendent, Kennebunk, Kennebunkport & Wells Water District

The purpose of this presentation is to share the experience of a public water system impacted by PFAS and to describe the current status of the PFAS contamination issue in Maine.

Per- and Polyfluoroalkyl Substances (PFAS) are a family of very resilient, man-made organic chemicals that have been used extensively for a variety of purposes; including but not limited to fire suppression, water proofing and stain repellency. PFAS has an estimated half-life in humans of between three to six years. They are also very miscible in water and can also spread airborne. In the environment they don’t readily break down; as such they have been referred to as “forever chemicals”. The KK&W Water District found PFAS in one of its water supplies and has since mitigated the issue, with the assistance of Maine’s Drinking Water Program.

The larger concern however relates to the fact that this PFAS contamination did not come from a known contaminated site but from the approved (permitted) spreading of municipal and industrial residuals on nearby farmland; a common practice throughout the region. For this reason, the implications of PFAS contamination in Maine stretch far beyond that of drinking water.

As a result of increasing local, regional and national concern, in March, 2019 Governor Mills created Maine’s PFAS Task Force, on which the presenter was a member. Its final report outlines Maine’s next steps toward addressing the PFAS issue, which will be described in this presentation.

9:30AM-9:55AM
The Challenges of Modeling PFAS Transport from Soil to Groundwater at Legacy Sites

Approved for 0.5 TCH

Gail Lipfert, Troy Smith, Chris Evans, Sean Dougherty
Maine Department of Environmental Protection

The fate and transport of PFAS chemicals in the environment is poorly understood. The Maine Department of Environmental Protection used soil and groundwater PFAS concentrations from several sites to model PFAS transport through the vadose zone and along the groundwater flowpath.

We used SEVIEW, a software that incorporates SESOIL, which models the transport of contaminants through the vadose zone to the water table, and AT123D, which models contaminant transport along the groundwater flowpath.

Preliminary results indicate that adsorption to soil is the primary controller of the movement of PFAS through the soil to groundwater, hence, the amount of organic carbon in the soils (a rarely measured parameter) has a strong influence on rate of transport. The depth to groundwater strongly affects the arrival time of PFAS to the groundwater. At sites where the depth to groundwater was more than 6 meters, the arrival times were unrealistically long, not getting to some wells for over 900 years. These results are inconsistent with measured concentrations and more work will need to be done to improve models of long-distance transport of PFAS. At other locations where the vadose zone transport distances are shorter, the modeled groundwater concentrations are generally comparable to measured concentrations.

Our primary conclusion is that modeling current soil and groundwater PFAS data with SEVIEW is more consistent with measured concentrations under simple scenarios and well-established conditions, but not consistent with measured concentrations when the current or initial conditions are poorly known and long transport distances are involved.

10:00AM-10:25AM
Bench-Scale Fractionation Technology to Treat PFAS Impacted Industrial Wastewater in the U.S.

Baxter Miatke, John Anderson, Dave Liles, Corey Theriault
Arcadis U.S.

Arcadis designed and built a bench-scale fractionation column, first of its kind known in the U.S., to test PFAS removal efficiency of industrial wastewater. The Arcadis Treatability Lab optimized a patented technology by retrofitting a commercially available protein skimmer into a fractionation column for PFAS treatment utilizing multiple gases. This presentation will answer what modifications to the fractionation column were done to optimize the fractionation technology and why it works well for PFAS treatment specifically. This presentation will demonstrate the practical adaptation and modification of existing commercially available systems in the U.S. for fractionation treatment of PFAS.

Afternoon Session

1:30PM-1:55PM
The Degradation of A/B AFFF Foam in Real Time at a Small Site in Maine

Approved for 0.5 TCH

Louise Roy
Bureau of Remediation & Waste Management, Maine Department of Environmental Protection, Augusta, ME

Nationally, much of the focus of PFAS research is directed towards large sites, such as military bases, landfills, and firefighter training areas. However, small sites with a single event can provide insight into the degradation process of PFAS in a natural environment and the TOP Assay’s ability to predict precursor transformations.

A vehicle fire in February of 2019 provided us the opportunity to study the movement and degradation of an A/B AFFF foam after a single introduction into the environment. The foam and petroleum products from the event made their way to a well on the property, which we were able to sample with some frequency. Maine DEP installed two large carbon filters to protect the home’s drinking water. Results showed that the TOP Assay appears to be a good indicator of which products will occur during the natural degradation of 6:2 FTS. In this presentation, I show a slow progression of precursors to products using stiff diagrams. This presentation will give some background on the TOP assay and will touch on the treatment’s ability to detect compounds outside of the normal suite of 24 analytes.

2:00PM-2:25PM
Does Food Waste Recovered for Composting Represent a Risk to our Food System?

Astha Thakali (Student), Jean D. MacRae
Civil and Environmental Engineering, University of Maine

Recycling food waste is a good way to reduce the climate and environmental impacts of our food system by returning the nutrients to the soil. However, there is always a possibility of contamination of the waste materials with non-food materials. Contaminants may enter the food supply chain at various points, from pesticides applied during production, to contamination from packaging materials, to poor separation from non-food wastes in homes and institutions. The purpose of this study is to determine if there are any differences in the levels of contamination when participation is voluntary versus mandatory. The goal is to identify any emergent risk associated with cyclical food systems so that appropriate policies and programs to reduce risks can be identified. Food waste was collected from three states (MA, ME and VT) and from six source types. They were screened for heavy metals, halogenated organics (EOX), pathogens and antibiotic resistance genes (ARGs). A subset of samples were chosen for PFAS testing and for high throughput sequencing. None of the samples exceeded any heavy metals and EOX contaminants regulatory limits. Pathogens were rarely seen in the samples. In contrast, ARGs were detected in almost all the samples. So far, our results show that there are no significant differences in chemical or biological contamination of food wastes between regulated and non-regulated states, however both regulatory environments have issue with ARGs contamination.

2:30PM-2:55PM
Pharmaceutical Agent Cetylpyridinium Chloride Inhibits Immune Mast Cell Function

Bright Obeng (Student), Bailey E. West, Marissa S. Kinney, Christian M. Potts, Suraj Sangroula, Sasha R. Weller, Alan Y. Baez, Julie A. Gosse
University of Maine, Orono, ME

Cetylpyridinium chloride (CPC) is an antimicrobial used in consumer products such as mouthwashes at concentrations up to 3 millimolar, thus exposing humans to high concentrations. There is minimal information on eukaryotic toxicology of CPC; hence, there is urgent need for information since humans and wildlife are being exposed to CPC. Mast cells, ubiquitous through the body, sit at the hub of numerous physiological processes and diseases. We have demonstrated that CPC potently inhibits functioning of RBL-2H3 mast cells, including their ability to degranulate, which is the release of bioactive substances such as histamine. Degranulation inhibition occurs at non-cytotoxic CPC doses as low as 1 micromolar, ~1000-fold lower than the concentrations found in consumer products. We have investigated the molecular mechanisms underlying the inhibition of mast cell degranulation by CPC. Using the genetically-encoded voltage indicator ArcLight A242 and confocal microscopy, we have shown that CPC does not interfere with the plasma membrane potential of the mast cells. Another hypothesis being studied is that CPC interacts with plasma membrane lipid phosphatidylinositol 4,5 bisphosphate (PIP2) electrostatically, thus shutting down PIP2-mediated degranulation. This hypothesis is being investigated using confocal microscopy and image analysis of a fluorescently-labeled protein, MARCKS, that specifically binds PIP2 at the plasma membrane. This research will provide knowledge on the effects of CPC on mammalian signaling and allow prediction of CPC effects on cell disparate cell types that share similar signaling elements. This study will provide better understanding of the overall effect of CPC on human and wildlife health.

3:00PM-3:25PM
Triclosan Disrupts Plasma Membrane Electrochemical Potential in Immune Cells

Suraj Sangroula (Student), Alan Baez, Juyoung Shim, Bright Obeng, Grace Bagley, Jack Burnell, Julie A. Gosse
University of Maine, Orono, ME

Triclosan (TCS) is a wide-spectrum antimicrobial agent that had been used in numerous consumer products over decades, until the FDA recently banned TCS from most items. Despite this ban, TCS can still be found in household products that are not regulated by the FDA. TCS inhibits the functions of both mast cells and all cells’ mitochondria. Mast cells are found in most human tissues and play important roles in a wide array of biological processes and diseases. Through investigating the mechanisms by which TCS disrupts mitochondrial and mast cell signaling, the Gosse lab found that TCS depolarizes the mitochondrial membrane and disrupts cellular Ca2+ dynamics. Triclosan’s effects disappear when its ionizable hydroxyl group is not present. These findings suggest TCS to be a proton ionophore capable of disrupting the plasma membrane electrochemical potential (PMP). In this study, we have imaged a fluorescent, genetically-encoded voltage indicator (GEVI) called ArcLight A242 with confocal microscopy and image analysis to probe TCS effects on mast cell PMP. Utilizing a GEVI for the first time in mast cells, we observed plasma membrane depolarization in the presence of Triclosan. This method was also tested on human Jurkat T cells (another type of immune cell). We see a similar effect of Triclosan with this cell type as well. TCS disruption of PMP could provide a mechanistic explanation of triclosan’s disruption of Ca2+ influx, immune cell function, and a host of other processes dependent on PMP.