How Clean Is Mill Lake?
Mill Lake is a clean lake by Minnesota standards. It received a water quality grade of B (Good) based on EPA monitoring data. Water clarity (Secchi depth): 11 ft. Phosphorus: 24 µg/L. Trophic State Index: 46.
Cleanliness Snapshot
| Metric | Mill Lake | Minnesota avg |
|---|---|---|
| Overall Grade | B | C |
| Water Clarity (Secchi) | 11 ft | — |
| Phosphorus | 24 µg/L | <30 = clean |
| Trophic State Index | 46 | <50 = clean |
How does Mill Lake compare?
Mill Lake's grade of B matches or beats the Minnesota state average of C. It ranks #27 of 51 lakes in Douglas County by water quality score. Multi-year monitoring data shows water quality is declining based on 3 years of records.