How Clean Is Hall Lake?
Hall Lake has very poor water quality and a high algae bloom risk. It received a water quality grade of F (Very Poor) based on EPA monitoring data. Water clarity (Secchi depth): 2.6 ft. Phosphorus: 96 µg/L. Chlorophyll-a (algae): 80.1 µg/L. Trophic State Index: 69.
Cleanliness Snapshot
| Metric | Hall Lake | Minnesota avg |
|---|---|---|
| Overall Grade | F | C |
| Water Clarity (Secchi) | 2.6 ft | — |
| Phosphorus | 96 µg/L | <30 = clean |
| Chlorophyll-a (Algae) | 80.1 µg/L | <10 = clean |
| Trophic State Index | 69 | <50 = clean |
How does Hall Lake compare?
Hall Lake's grade of F falls below the Minnesota state average of C. It ranks #3 of 7 lakes in Martin County by water quality score. Multi-year monitoring data shows water quality is declining based on 5 years of records.