2025 Maine Sustainability & Water Conference

Thursday, March 27, 2025
Augusta Civic Center
Augusta, Maine

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Session D – PFAS in the Maine Environment: Current Research in Ecosystem Health and Strategies for Mitigation and Remediation  

All Day Session

This session is approved for 4 Training Contact Hours through the Maine CDC Drinking Water Program. Sign-up sheets will be available in the session room.

Session Co-chairs:
Maxwell Meadows, USGS, New England Water Science Center
Chris Evans, Maine Department of Environmental Protection
Hannah Sterling, Bigelow Laboratory
Richard Hilliard, MDI Biological Laboratory

This session will bring together researchers monitoring PFAS contamination of groundwater, surface water, and drinking water and assessing the impact on ecosystem health. PFAS sources generally originate on land and include inputs from septic systems and overboard discharge (OBD) systems on individual properties, application of wastewater treatment plant residuals to land surfaces, municipal wastewater discharges, industrial effluents, run off, and atmospheric deposition. The session will explore PFAS loading and transport in various environmental matrices, as well as the potential impacts of PFAS on coastal ecosystem health and marine resources. Identified practices for mitigation and remediation, in addition to potential environmental controlling factors will also be discussed. The session will include morning and afternoon talks and thematic breakout sessions for researchers to meet with session participants to share ideas, prioritize next steps, and identify areas for potential collaboration. Outcomes of the breakout sessions will be highlighted on a new website for showcasing and sharing PFAS research with public audiences called PFAS in Maine.

Session Schedule

Morning Session

Afternoon Session

Presenters are indicated in bold font.

8:30AM – 8:55AM
Evaluation of Soils and Groundwater Based on the Assessment of Fields with Historic Land Application of Biosolids

Chris Evans1, Maxwell Meadows2

  1. Maine Department of Environmental Protection, Augusta, ME; Gordon.C.Evans@maine.gov
  2. U.S. Geological Survey, New England Water Science Center; mmeadows@usgs.gov

Statewide sampling results in Maine by the Department of Environmental Protection (DEP) and the Department of Agriculture, Conservation and Forestry (DACF) provide a significant resource for characterizing the nature and extent of per- and polyfluoroalkyl substances (PFAS) in agricultural land and related impacts to nearby water supplies. As new screening levels are generated for additional PFAS compounds, statewide datasets will support the assessment of the extent of land that may represent a risk for leaching to groundwater or crop/animal exposure. Recently compiled statewide groundwater PFAS data reveals a concentration range from non-detect to 54,148 ng∙L-1 for the sum of 6 PFAS (PFDA, PFNA, PFOS, PFOA, PFHpA, and PFHxS) in domestic wells. Of the sampled domestic wells (n = 2,282), 67.3% had detectable concentrations for the sum of 6 PFAS and 22.7% exceeded the state maximum contaminant level of 20 ng∙L-1. These percentages may be higher still considering the new standards from the U.S. EPA (2024). Geospatial datasets including domestic well distances to confirmed sludge application parcels, generalized bedrock geochemical groups, and interpolated overburden thickness were used for comparison to the statewide groundwater data. Additionally, the statewide groundwater data will be related to data from a study initiated in 2020 which collected paired surface soil and shallow groundwater values to test field conditions at select locations in Maine. Data from the 2020 study suggest that PFAS detected in the shallow groundwater beneath licensed biosolid application fields may not always pose an immediate risk to typical domestic water supplies.

8:55AM – 9:20AM
Biochar Use to Reduce Crop Uptake of PFAS

Romy Carpenter, Northern Tilth, romy@northerntilth.com
Andrew Carpenter, Northern Tilth, andrew@northerntilth.com
Dr. Linda Lee, Purdue University
Elijah Openiyi (student), Purdue University

The overall goal of the research is to investigate whether the incorporation of biochar and/or high carbon ash in agricultural fields that have been heavily contaminated with PFAS because of historical applications of high PFAS-containing sludge will reduce PFAS uptake by grass and improve overall soil health. These objectives will be achieved by monitoring grass uptake of PFAS compounds in fields plots on soil that’s contaminated with PFAS; each field plot receiving biochar or high carbon ash, which has similar properties to biochar, at one of two application rates. Results will be compared to untreated plots (control plots). Additionally, collaborators at Purdue University are conducting greenhouse trials, which are similar in design to the field trials, to investigate if high carbon ash reduces the uptake of PFAS in grass. 

Northern Tilth has conducted one season of field trials in plots at a farm in Unity, ME and expects to continue testing these plots for at least one more growing season. At this time, Northern Tilth has results from Purdue University’s greenhouse trials, which show that high carbon ash significantly reduced the update of PFAS compounds in grass, and preliminary results from the field trials in Unity, which don’t yet show that biochar or high carbon ash have a significant impact on grass uptake of PFAS. This indicates there is potential in using biochar or high carbon ash as a soil amendment to reduce PFAS uptake in crops that are grown in contaminated fields.

9:20AM – 9:45AM
PFAS in Penobscot Bay and River Receiving Waters

Carey Friedman, Department of Ocean Studies, Maine Maritime Academy, Carey.friedman@mma.edu
LeAnn Whitney, Department of Ocean Studies, Maine Maritime Academy, Leann.whitney@mma.edu
Jitka Becanova, Graduate School of Oceanography, University of Rhode Island, becanova@uri.edu

Maine has been leading the nation in directing resources toward addressing the PFAS problem, including monitoring inland surface waters for PFAS from sludge application and/or spills. Not as much attention has been paid to the marine environment, as it is further from most known point sources. However, coastal waters and ecosystems are the ultimate sink for PFAS released via wastewater effluent into rivers, streams, and directly into coastal waters. We are interested in how widespread PFAS contamination is in the Penobscot Bay area to assess whether resources should be directed toward protecting Maine’s coastal ecosystems and seafood economy from PFAS contamination. We collected water samples from nine locations near the release of wastewater effluent in Penobscot Bay and River, ranging from Rockland (southwest), to Indian Island (north), to Castine (southeast). Samples were collected on three occasions, two weeks apart, in the 2024 late spring/early summer and analyzed for the presence of fifteen PFAS, including PFOA and PFOS. Preliminary results indicate that PFAS were detected in all water samples, with 15PFAS ranging from ~0.5 ng/L to <6 ng/L at most sites. However, samples collected near the former Verso paper mill in Bucksport showed 15PFAS concentrations ranging from ~50 ng/L to 185 ng/L. Efforts to quantify PFAS concentrations in phytoplankton and passive samplers collected alongside water samples are ongoing. This study provides critical insights into the presence and distribution of PFAS in an understudied yet ecologically important ecosystem and highlights the need for continued monitoring of PFAS in the Penobscot Bay area.

9:45AM – 10:10AM
From the River to the Sea: Understanding and Mitigating Terrestrial Sources of Coastal PFAS Contamination

Richard F. Hilliard, Mount Desert Island Biological Laboratory, rhilliard@mdibl.org
Ludwin Moran Sosa, College of the Atlantic, ludwin.mosa@gmail.com
Cole Toth, Colorado State University, ctoth@mdibl.org, peskycardinal@gmail.com
Hannah Sterling, Bigelow Laboratory for Ocean Sciences, hsterling@bigelow.org
Christoph Aeppli, Bigelow Laboratory for Ocean Sciences, caeppli@bigelow.org
Jane E. Disney, Mount Desert Island Biological Laboratory, jdisney@mdibl.org

Per- and polyfluoroalkyl substances (PFAS) are a class of synthetic chemicals—used widely in industrial and consumer products—now ubiquitous in the natural environment. Due to the strength of their carbon-fluorine bonds, natural degradation is rare. While the earliest documented sites of PFAS contamination in Maine were inland agricultural areas; currently PFAS are detected in dairy milk, private drinking wells, fresh- and saltwater fish, streams, crops, and nearly everywhere examined. On Mount Desert Island, PFAS have been detected in numerous community and private wells, attributed to waste collections including landfills and septic systems. From these hotspots, further investigations have detected PFAS in streams, sediments, and the coastal environments of Bass Harbor and Somes Sound. Analysis has shown strong correlations between a local school’s wastewater, well-water, wetlands, nearby residential wells, and a downstream culvert draining to a coastal salt marsh, implicating a common source–likely the school’s septic system. We suspect that numerous small-scale sources along the coast may be contributing to PFAS loading in the marine environment, impacting coastal areas critical to the culture, economy, history, and health of Maine and/or diluting the parts per trillion concentrations of PFAS within the much larger ocean, bypassing an area where they could be captured while more highly concentrated. Here we outline our systematic approach to understand the relationship between terrestrial PFAS sources and their transport to and behavior in coastal systems: including potential uptake by shellfish and mitigating influence of salt marsh plants and sediments.

1:30PM – 1:55PM
PFAS Distributions in Surface Waters of the Casco Bay Estuary

Hannah Sterling, Bigelow Laboratory for Ocean Sciences, hsterling@bigelow.org
Heather Kenyon, Friends of Casco Bay, hkenyon@cascobay.org
Mike Doan, Friends of Casco Bay, mdoan@cascobay.org
Ivy Frignoca, Friends of Casco Bay, ifrignoca@cascobay.org
Christoph Aeppli, Bigelow Laboratory for Ocean Sciences, caeppli@bigelow.org

Per- and polyfluoroalkyl substances (PFAS) are emerging contaminants of national concern for both ecosystems and human exposure. Recently, awareness has been brought of the negative human health impacts associated with PFAS compounds, though studies have mostly focused on their distribution in terrestrial environments, associated with groundwater, wastewater effluents, and sludge. Few studies focus on the distribution and ecosystem effects in an estuarine environment, where many PFAS compounds originating from terrestrial sources will be transported. In estuaries, PFAS compounds may affect marine biota and human health through recreational use of these waterways and seafood consumption. A seasonal-scale PFAS sampling campaign is in progress across over 90 sites in the Casco Bay Estuary system in a collaboration between Bigelow Laboratory and Friends of Casco Bay to investigate PFAS distributions and potential sources. Two large campaigns were completed in September and October of 2024, showing indications of source specific patterns of PFAS distribution across the sampling area. Furthermore, we found elevated PFAS levels above EPA drinking water standards in Harpswell Cove in response to the August 2024 PFAS-laden firefighting foam (AFFF) spill at the Brunswick Naval Air Station. An extended monthly sampling campaign in Harpswell Cove, which will span into Fall 2025, has been implemented to investigate the time scale of dilution from the spill contamination. This Casco Bay-wide PFAS investigation is the first of its kind to this scale, and will provide valuable information to ensure healthy estuaries for both the ecosystem and humans.

1:55PM – 2:20PM
PFAS in Fish and Water Following Maine’s Largest Release of Toxic Firefighting Foam

Tom Danielson, Maine Department of Environmental Protection, thomas.j.danielson@maine.gov

On August 19, 2024, there was a failure of the fire suppression system inside an airplane hangar at the Brunswick Executive Airport.  Approximately 1,450 gallons of aqueous film-forming foam (AFFF) concentrate mixed with 50,000 gallons of water were released.  Only a small portion of the AFFF was captured in cleanup efforts.   Some of the foam made its way into a Merriconeag Stream and Mare Brook, which flows into the ocean at Harpswell Cove.  Some of the foam entered the sewer system and went to the Brunswick wastewater treatment plant, which discharges to the Androscoggin River.  Following the release, the Department of Environmental Protection (DEP) collected weekly water samples at several locations along the Androscoggin River, Merriconeag Stream, Mare Brook, and Harpswell Cove. The AFFF contained large quantities of perfluorooctane sulfonic acid (PFOS), which bioaccumulates in fish.  To determine the extent of PFOS bioaccumulation, DEP collected freshwater fish and marine fish and shellfish.  Preliminary results show minimal PFOS contamination resulting from the AFFF release in the Androscoggin River and severe initial PFOS contamination in the other waterbodies.

2:50PM – 3:15PM
Using Avian Piscivore Bioindicators to Monitor PFAS and Other Environmental Contaminants in Maine – A Biomonitoring Proposal
Chris DeSorbo, chris.desorbo@briwildlife.org,
Micah W. Miller, Helen Yurek, Cassie Gilham, Emily Fellows, Logan Route, Lucas Savoy, David Evers
Biodiversity Research Institute

Maine ecosystems have a long history of environmental pollution. Several of Maine’s most iconic major river corridors, particularly the Androscoggin, Kennebec, and the Penobscot, have well-documented contamination from legacy pollutants and mercury, and Maine lakes have some of the highest mercury burdens in the country. Public concern is now growing regarding the extent of contamination from per- and poly-fluoroalkyl substances (PFAS) in Maine, but information on PFAS exposure risk remains poorly studied in large portions of Maine’s lakes and rivers. To facilitate discussions on contaminant monitoring approaches, we present findings of recent efforts to understand patterns of PFAS in Maine’s environment using two well-established avian contaminant bioindicators: Common Loons and Bald Eagles. We report on preliminary targeted PFAS analyses conducted on blood and inviable eggs collected from Maine loons and eagles, and of associations among habitat type, watershed, and other factors that may influence exposure risk. Using current literature, we assess toxicological risk to these two iconic top predators. Loss or defunding of broad-scale and statistically robust contaminant monitoring programs underscores the need for cohesive sampling schemes, especially for watersheds with known historic and emerging exposure, or remote areas chronically overlooked for logistical reasons. Using an example of a long-term watershed-based environmental contaminants biomonitoring plan implemented in the midwestern U.S., we explore the feasibility of implementing a similar monitoring program in Maine.

3:15PM – 3:40PM
Exploring PFAS Concentrations, Exposure Routes, and Trophic Transfer in Wood Turtles (Glyptemys insculpta) in an Impacted Area of Maine

Kara J. SantaLucia (student), Ecology and Environmental Sciences, University of Maine, kara.santalucia@maine.edu
Matthew W.H. Chatfield, School of Biology and Ecology, University of Maine, matthew.chatfield@maine.edu
Jitka Becanova, STEEP, University of Rhode Island, becanova@uri.edu
A. Dianne Kopec, Mitchell Center for Sustainability Solutions, University of Maine, dkopec@maine.edu

Per- and polyfluoroalkyl substances (PFAS) are a group of ubiquitous synthetic chemicals that pose significant risks to both animals and humans. Of particular concern are their implications for sensitive species like the North American wood turtle (Glyptemys insculpta), designated as a Species of Greatest Conservation Need in Maine. Wood turtles exhibit seasonal movement between aquatic overwintering habitats and terrestrial summer foraging habitats, leading to multiple potential PFAS exposure routes. Focusing on a population involved in a long-term monitoring project in central Maine, we collected water, sediment, diet, and nonlethal tissue samples to assess the severity of PFAS contamination in the turtles, their aquatic habitat, and their summer food web, as well as to identify potential exposure routes and quantify trophic transfer. Out of 56 potential PFAS compounds included in the analysis, 15 were detected in the stream water samples from our study site (n=10), showing a geographic gradient, with sum PFAS concentrations reaching 145 ng/L and a median concentration of 66 ng/L. Concentrations of individual PFOS and PFOA generally exceeded the EPA’s Draft Human Health Ambient Water Quality Criteria. 10 PFAS compounds, mostly long-chained, were found in turtle blood serum (n=23), with the highest sum PFAS concentration >400 ng/mL and median concentration of 41 ng/mL, indicating bioaccumulation. Our study adds to the growing body of knowledge regarding PFAS contamination in the environment and their propensity for transfer and bioaccumulation in an imperiled species.

3:40PM – 4:00PM

Breakout Session