Testing is set to take place at Battle Creek’s Air National Guard Base to determine if the groundwater and soil are contaminated with possible toxic substances.

MLive says that the ANG Base has had firefighting foam used on the property in the past, and concerns have been raised recently about the per and poly-fleuroalkyl substances, known as PFAS, that were contained in that foam. The testing is set to begin April 16, and is being carried out to determine if there’s any environmental or health impact.

While the Air Force is testing the base itself, the Michigan Department of Environmental Quality says they also plan to sample wells used for drinking water in the area around the base as well. The MDEQ says the testing is simply precautionary.

PFAS can stick around in the human body for a long time, and the Environmental Protection Agency says on their website the chemicals can cause cancer and problems with infant birth rates.