How are these rankings calculated?

Lakes are graded A through F using the Metropolitan Council methodology, which combines Secchi depth (water clarity), total phosphorus, and chlorophyll-a (algae) into a single score. Source data comes from the EPA Water Quality Portal.

Cleanest Lakes in Mercer County, Ohio

No qualifying lakes in Mercer County, Ohio matched this filter.

Cleanest Lakes in Mercer County, Ohio

More Answers for Mercer County, Ohio