Thriving Earth Exchange

Featured image for the project, Investigating PFAS contamination in the Town of Campbell and French Island

Image by David Mark from Pixabay.

Contenido

Breve descripción
Descripción
Equipo del proyecto

PFAS contamination has been detected in the shallow water aquifer beneath the Town of Campbell and French Island. This contamination affects the private wells and groundwater for the 4,300 residents and 50+ businesses in the area. We seek to conduct a hydrogeomorphic study of the aquifers and connectivity as well as create a risk MAP (mapping analysis and planning), with the goal of determining a long-term solution to the water contamination problem

Descripción

Acerca de la Comunidad

The Town of Campbell is an independent municipality situated on a roughly 4 square mile island hugged by the Mississippi River/Lake Onalaska on the west and Black River to the east.

We are located in West Central Wisconsin bordering Minnesota. We have 4,300 residents in roughly 1,600 households. The City of La Crosse (a separate municipality) owns parts of the island including the Municipal Airport which is believed to be the source of PFAS contamination (due to use of AFFF).

Water use is woven into the fabric of Wisconsin culture. Safe drinking water is the foundation of our health, economic drivers, and recreational use. This includes farming, beer and cheese production, fishing, waterfowl hunting, boating, and tourism.
Campbell is a rural community where residents and businesses rely on private well water. This includes the USGS Upper Midwest Environmental Sciences Center (UMSEC) which is one of the 5^th largest science centers in the nation. UMESC has the only well with non-detectable levels of PFAS and is situated in the Mt. Simon aquifer. Their other three non-potable wells are all contaminated which affects their aquaculture research. Their fish labs can contain upwards of 10,000 fish at any given time. Research on the accumulation of PFAS in fish tissue in addition to depuration rates of PFAS is a key interest.

Sobre el proyecto

The community would like to learn about the underlying hydrogeomorphic structure (including the aquifer system) to estimate the extent of PFAS contamination and where it may spread. This information will be used to identify a safe long-term water supply for the residents and businesses located on French Island.

The last research on the hydrogeomorphic structure beneath the island was conducted by USGS approximately 20 years ago. 99% of the residents currently draw water via private wells from the shallow sand and alluvial aquifer roughly 75-120 feet below grade. The deep aquifer is the Mount Simon (approximately 150-300 ft below grade) and extends roughly 100 miles in this area. In some regions, the Mount Simon aquifer is constrained by the Eau Claire bedrock formation which has some overlaying aquitard features. Some PFAS tests at the same location in December 2020, April 2021, and October 2021, show variations in PFAS detection levels ranging from 10 ppt in winter to 22 ppt in spring. Initial results show significant variability across the island as the river elevations change. Currently, we have data for more than 555 tests, which are mapped by address. Previously well depth did not correlate to levels of PFAS. We would like to additionally compare them by water elevation levels and season.

We seek a hydrogeomorphic modeling study to better understand the directional flow, rate, and impact of PFAS in the aquifer system and to link the water elevations at the time they were tested to variations in PFAS detection levels. Since the Town of Campbell and French Island are hugged by two rivers (the Mississippi on the West (with Lake Onalaska) and the Black River on the east) we need to find out how water levels/elevations of the rivers affect the ground water table and the flow direction. Additionally, little research has been done to study the deep Mount Simon aquifer, and many questions remain including: 1.) Does the Eau Claire layer still exist beneath the Town of Campbell and French Island? If so, to what extent? 2.) How does the Eau Claire layer impact the Mount Simon aquifer, and has erosion impacted its protective characteristics? 3.) Could contamination from the shallow aquifer migrate to the Mount Simon aquifer? The answers to these questions will help the Town of Campbell make important decisions regarding the long-term safe water solutions. 4) Is there a level at which wells could be placed to avoid contaminated groundwater flow?

Note: Opportunities for additional related projects in the Town of Campbell, WI exist for future studies including method development for detecting PFAS contamination for more samples at lower costs, PFAS depuration in animal tissue, experiments detecting short-chain hydrophilic PFBA, etc.