Cleaner Lakes Than Teal Lake Deep
1 higher-graded lake within 30 miles, ranked by grade improvement and proximity.
Teal Lake Deep carries a Grade C (Fair) water quality score. Within 30 miles, 1 lake holds a higher grade. Little Lake Deep (Cook County, Grade B, null mi away) is the closest meaningful upgrade.
Reading the cohort
Just one nearby water body scores higher than Teal Lake Deep on the EPA metrics within a 30-mile radius. The single cleaner option (below) is the practical alternative; beyond that, the next-cleanest lakes sit farther out and warrant a longer drive only if the water-quality difference is the deciding factor.
The closest cleaner alternative — Little Lake Deep in Cook County, Grade B — sits miles from Teal Lake Deep. At that distance, the substitution cost is essentially zero: same drive time, same regional access, demonstrably cleaner water on the EPA indicators. For repeat visitors who care about clarity or phosphorus levels, swapping the routine to Little Lake Deep is mostly a habit change rather than a logistics change.
The EPA water-quality grading combines clarity (Secchi depth), phosphorus, and chlorophyll-a measurements from state environmental sampling. A higher letter grade reflects measurably cleaner water on those indicators, not subjective beauty or access quality — a Grade A lake might have worse boat-launch facilities or shoreline access than a Grade C neighbor, so the ranking is one input alongside the rest of trip planning. See the methodology page for the full grading formula.
How this list is built
Every lake on LakeQuality has a calculated grade from EPA Water Quality Portal samples — secchi depth, total phosphorus, and chlorophyll-a measured against Metropolitan Council thresholds. To suggest cleaner alternatives, we filter lakes within 30 miles to those with a strictly higher numeric score, then rank by grade improvement with a small proximity tiebreak. Cross-state and limited-data lakes are excluded so the list stays locally relevant.