How Clean Is Boulder Lake?
Boulder Lake is a clean lake by Wisconsin standards. It received a water quality grade of B (Good) based on EPA monitoring data. Water clarity (Secchi depth): 5.6 ft. Phosphorus: 21.6 µg/L. Trophic State Index: 50.
Cleanliness Snapshot
| Metric | Boulder Lake | Wisconsin avg |
|---|---|---|
| Overall Grade | B | B |
| Water Clarity (Secchi) | 5.6 ft | — |
| Phosphorus | 21.6 µg/L | <30 = clean |
| Trophic State Index | 50 | <50 = clean |
How does Boulder Lake compare?
Boulder Lake's grade of B matches or beats the Wisconsin state average of B. It ranks #1 of 103 lakes in Vilas County by water quality score. Multi-year monitoring data shows water quality is improving based on 2 years of records.