Date of Award

2022

Document Type

Honors Thesis (Open Access)

Department

Colby College. Environmental Studies Program

Advisor(s)

Gail Carlson

Second Advisor

Manny Gimond

Third Advisor

Philip Nyhus

Abstract

PFAS (per- and polyfluoroalkyl substances) are toxic, persistent, and bioaccumulative chemicals that are used in a variety of consumer products and industrial applications. Paper mills across the state of Maine have used PFAS in their industrial paper making processes, and their wastes often flow for treatment into municipal sewage treatment facilities. PFAS contaminated municipal wastewater from the general use of PFAS consumer products are also processed by these plants. Liquid waste is condensed into solid waste septage and sludge, and in what was thought to be an environmentally friendly repurposing practice, municipal sludge and septage has been spread on plots of land, including farm fields, as fertilizer, across the state of Maine. Testing in recent years has uncovered that this sewage and sludge was highly contaminated with PFAS chemicals and is the cause of statewide PFAS contamination of surface water, groundwater— notably many residential wells— soil, plants, animals, animal products, and people. This study builds on prior studies to further characterize surface water, groundwater, snow and drinking water contamination in the greater Waterville area. Martin Stream, Messalonskee Stream and Fish Brook are contaminated with PFAS, and contamination is moving from Fairfield to Waterville via contaminated stream water. Groundwater sampling results suggest that groundwater-surface water mixing is occurring. Snow samples taken at Quarry Road Trails, a recreational area adjacent to Messalonskee Stream, after a ski race where no PFAS-containing ski waxes were used showed much less contamination than two years ago when fluoro waxes were used at this same race. Sampling on the Kennebec River suggested that industrial sites on the river may be sources of local PFAS contamination, although more study is needed. Seasonality affects the pattern of specific PFAS analytes in streams. PFAS detected in the municipal water supply provided by Kennebec Water District show that contamination is the same in intake water and finished water, suggesting that KWD is not filtering out PFAS at its treatment plant. Effective simple filtration mechanisms such as a Brita pitcher or water bottle filler station can eliminate PFAS from drinking water.

Keywords

Environmental chemistry, Per- and polyfluoroalkyl substances (PFAS), Persistent organic pollutants (POPs), Emerging contaminants, Ski wax, Sludge and Septage, Source tracking, PFAS in paper

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