B
Mary Lake
Douglas County, Minnesota
Water Quality Grade: B — Good
Moderate clarity — visible to about 9.8 feet. Phosphorus level: 19 µg/L.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3 m | C |
| Phosphorus | 19 µg/L | A |
| Chlorophyll-a (Algae) | No data |
County Ranking
Ranked #31 of 55 lakes in Douglas County
Data Sources
Data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2024-10-14
Monitoring stations: 3