While Battle Creek’s Municipal Water System has tested negative for any toxic contamination from a certain group of chemicals, another water system in town had a different result.

MLive says that the Michigan Department of Environmental Quality conducted testing along the Kalamazoo River for chemicals in the Per and Polyfleuroalkyl Substance category, and results varied throughout; specifically, high results were found for PFOS, a chemical which Michigan set a standard for human and aquatic life health at 12 parts per trillion; that level was set to help determine whether fish consumption is safe.

In Battle Creek, high PFOS levels were found in the Kalamazoo River; samples taken at Custer Drive in Bedford Township showed levels of 13 and 14 ppt, and a sample at the Battle Creek Linear Park had a level of 47 ppt. The river also had levels above the advisory in Otsego, and downstream of Parchment.

While the cause of these high levels isn’t yet confirmed, DEQ spokespeople say that there is a “correlation” between the PFOS and the use of firefighting foams at the Battle Creek Air National Guard Base. In August, Representative Fred Upton pointed out that certain DEQ sampling at the ANG Base had PFOS levels of 55,500 ppt, and called for the state to release more data on the results.

The DEQ says they will continue to investigate and determine the best way to clean up the river.