How Clean Is Loon Lake?
Loon Lake is among the cleanest lakes in Minnesota. It received a water quality grade of A (Excellent) based on EPA monitoring data. Water clarity (Secchi depth): 17.4 ft. Phosphorus: 5 µg/L. Chlorophyll-a (algae): 1.6 µg/L. Trophic State Index: 33.
Cleanliness Snapshot
| Metric | Loon Lake | Minnesota avg |
|---|---|---|
| Overall Grade | A | C |
| Water Clarity (Secchi) | 17.4 ft | — |
| Phosphorus | 5 µg/L | <30 = clean |
| Chlorophyll-a (Algae) | 1.6 µg/L | <10 = clean |
| Trophic State Index | 33 | <50 = clean |
How does Loon Lake compare?
Loon Lake's grade of A matches or beats the Minnesota state average of C. It ranks #19 of 44 lakes in Cook County by water quality score. Multi-year monitoring data shows water quality is declining based on 5 years of records.