St. Clair County Lake Quality

St. Clair County holds 10 monitored lakes. With a sample that small the county-level summary describes those specific waters, not necessarily every water body in the county. 1 of those lake carry an A–F grade. The county-level summary describes that subset, not every water body listed. On average, St. Clair County lakes grade D, with phosphorus loading and reduced clarity showing up across most of the dataset.

The county's lakes lean shallow, which makes the grades sensitive to wind, sediment-resuspension, and any nutrient inputs from the watershed. The cleanest lake on the books is Nees Lake (D); the most-stressed is Nees Lake (D).