The biggest natural lake in Iowa has tested positive for a very high level of E. Coli.

According to KCCI, the Iowa Department of Natural Resources found that Spirit Lake in northwest Iowa by Okoboji contained over 10 times the acceptable limit of the E. Coli bacteria.

The DNR says that the high level and rapid growth of bacteria in the lake this summer could be from the heat waves we've experienced or from rain washing animal waste into the water (ew).

The DNR is testing the lake again.

The Beaches Are Testing Different

There's a specific beach on Spirit Lake that's tested very high in bacteria concentration. Iowa Capital Dispatch reports that Crandall's Beach tested very high for E. Coli. DNR's test of the water (less than 1/2 cup) from that beach found over 24,000 viable bacteria in that sample. It's far over the minimum that prompts the DNR's "you probably shouldn't swim" warning.

Not the case on a beach on the opposite side of the lake. Iowa Capital Dispatch reports that Orleans City Beach had no detected toxins and just 10 viable bacteria in the DNR's sample. It's just across the lake from Crandall's Beach. Which seems kind of wild.

So should you swim at Spirit Lake? It's probably best to just stick to the landborne activities for now. It's also getting to be chillier as fall sets in so swimming isn't super appealing anymore.

Spirit Lake covers about 5,684 acres in Dickinson County. It's the largest natural lake in the state of Iowa.