PFAS Distribution in Lower Casco & Merrymeeting Bay Watersheds

Chris Aeppli, PhD, Environmental Chemist & Senior Research Scientist,
Bigelow Ocean Lab for Ocean Sciences

Wednesday, January 14, 2026 at 7:00 pm
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Tina Morris

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Christoph Aeppli is an environmental chemist and senior research scientist at Bigelow Laboratory for Ocean Sciences in East Boothbay, Maine. He leads a research program in marine pollution and a testing center for "forever chemicals" (PFAS). Chris studies the fate of organic chemicals in aquatic environments, with a focus on PFAS and oil residues from marine oil spills. His current work includes tracing the sources and pathways of PFAS in coastal waters such as Casco Bay. Aeppli’s research investigates the physical and chemical processes that control how these contaminants move, change, and affect marine life.

This project collected and shared data about the distribution, levels, and source contributions of PFAS in Casco Bay and its watershed including the Kennebec and Androscoggin River and Merrymeeting Bay. It includes bay-wide sampling, comprehensive PFAS analysis, assessment of source contributions (from facility effluent, stormwater, leachate from biosolid and firefighting foam impacted sites), and engagement with stakeholders and decision makers.

PFAS are a large group of emerging contaminants that are of national concern for ecosystem and human health. PFAS have multiple sources and primarily travel via groundwater and surface water, and, therefore, reach coastal ecosystems. The large number of PFAS compounds in the environment as well as the lack of detailed PFAS data in estuaries represents a major uncertainty about the scale and sources of the coastal PFAS problem. For Casco Bay, the sparse available data from water, sediment, and biota show that PFAS are present at highly variable concentrations, with several potential sources.

This project’s comprehensive sampling and PFAS analysis of 40 compounds provide high-quality baseline data. Statistical analysis of PFAS data will delineate the importance of various sources of PFAS into the lower watershed and in particular look at effects of the BNAS PFAS spill. This project aims to provide guidance to decision makers for appropriate source control measures and regulations to ensure the long-term health of Casco Bay.