A
Lake Superior Pt 1
Cook County, Minnesota
Water Quality Grade: A — Excellent
Crystal clear — you can see 28.7 feet down. Phosphorus level: 4.5 µg/L. Chlorophyll-a: 0.7 µg/L.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 8.75 m | A |
| Phosphorus | 4.5 µg/L | A |
| Chlorophyll-a (Algae) | 0.7 µg/L | A |
County Ranking
Ranked #22 of 144 lakes in Cook County
Data Sources
Data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2025-09-16
Monitoring stations: 1