Department or Program

Environmental Studies

Abstract

As more information is learned regarding the long-term health effects of per- and polyfluoroalkyl substances (PFAS), increasing regulatory measures are being taken to protect the public from these chemicals. States like Maine are on the forefront of such legislation, banning land-applied biosolids in 2022 for fear of PFAS contamination, with plans to halt sales of all unnecessary PFAS products in the state by 2030. The state has conducted some testing of groundwater supplies, but the near-ubiquitous nature of PFAS in manufacturing indicates contamination may be widespread. To prioritize testing in Maine’s most vulnerable aquifers, a groundwater susceptibility map has been developed using a modified form of the EPA’s DRASTIC model. The model uses geological, atmospheric, and land use data to estimate the relative vulnerability of groundwater across the state. Additionally, a heatmap of potential PFAS sources was created, where each site was assigned a risk score based on the upper magnitude of PFAS contamination associated with its industry. These maps were compared with state PFAS test results to determine the validity of each method. Regional vulnerability trends were found which indicate karst features, coarse glacial/fluvial deposits, volcanic geology, and urban development are signs of high groundwater vulnerability. Density of potential PFAS sources was also found to be highest around urban centers, with PFAS test data affirming the relationship. Recommendations are made for best management practices guided by the models, such as protection of the most vulnerable aquifers via rezoning and building factories on impermeable geologies. Future model development is encouraged with more robust datasets and additional fine-tuning of the statewide Depth to Groundwater, Depth to Bedrock, and Hydraulic Conductivity maps.

Level of Access

Open Access

First Advisor

Holly Ewing

Date of Graduation

5-2023

Degree Name

Bachelor of Science

Number of Pages

96

Components of Thesis

1 pdf file

DOI

https://doi.org/10.26780/2023.002.0002

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Open Access

Available to all.

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