How Clean Is Tom Lake?
Tom 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): 9 ft. Phosphorus: 8 µg/L. Trophic State Index: 40.
Cleanliness Snapshot
| Metric | Tom Lake | Minnesota avg |
|---|---|---|
| Overall Grade | B | C |
| Water Clarity (Secchi) | 9 ft | — |
| Phosphorus | 8 µg/L | <30 = clean |
| Trophic State Index | 40 | <50 = clean |
How does Tom Lake compare?
Tom Lake's grade of B matches or beats the Minnesota state average of C. It ranks #49 of 128 lakes in Cook County by water quality score. Multi-year monitoring data shows water quality is declining based on 5 years of records.