This aquifer had been polluted by a harmful chemical called Perfluorooctanoic acid (PFOA). USGS, known for its expertise in groundwater age-dating, helped by examining environmental clues in Bennington's groundwater to estimate when the water first entered the aquifer. This information is essential for understanding how PFOA contamination spread through the aquifer.
PFOA contamination in drinking water can lead to serious health problems, including cancer and thyroid disease. In 2016, many private wells in Bennington were found to have PFOA levels higher than what the U.S. Environmental Protection Agency considers safe.
Vermont initiated a collaborative effort to study the polluted aquifer, which culminated in this study. USGS's groundwater age-dating techniques helped pinpoint how and where PFOA was moving through the aquifer and provided a timeline for these movements.
The age-dating data helped scientists better understand the geologic structure's impact on PFOA's movement through groundwater and the timescale involved. By studying groundwater age differences in different wells, researchers were able to map out how groundwater flows and where pollutants like PFOA might be present.
This comprehensive study's findings can be applied to other fractured-rock aquifers in the future, helping communities protect their drinking water sources from contamination.