Is Thayer Lake Safe for Swimming?
Thayer Lake in Union County, Wisconsin has a water quality grade of D (Poor). Swimming not recommended, poor water quality with high algae risk. Water clarity: 3.5 ft visibility. Chlorophyll-a (algae): 34.3 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Overall Grade | D (Poor) |
| Water Clarity (Secchi Depth) | 3.5 ft |
| Chlorophyll-a (Algae) | 34.3 μg/L |
| Location | Union County, Wisconsin |
How does Thayer Lake compare?
With an overall water quality grade of D, Thayer Lake matches or beats the Wisconsin state average of Grade D. It ranks #2 of 6 lakes in Union County by water quality score.
Water clarity (Secchi depth) sits at 3.5 feet. That falls into moderate clarity — typical for lakes with some nutrient enrichment. Algae levels (chlorophyll-a) measure 34.3 µg/L — elevated; risk of harmful algal bloom advisories increases at this concentration.