Is Three Mile Lake Safe for Swimming?
Three Mile Lake in Union County, Iowa has a water quality grade of D (Nutrient-rich). Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum. Water clarity: 2.7 ft visibility. Phosphorus: 43 µg/L. Chlorophyll-a (algae): 28.4 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Overall Grade | D (Nutrient-rich) |
| Water Clarity (Secchi Depth) | 2.7 ft |
| Phosphorus | 43 μg/L |
| Chlorophyll-a (Algae) | 28.4 μg/L |
| Location | Union County, Iowa |
How does Three Mile Lake compare?
With an overall water quality grade of D, Three Mile Lake matches or beats the Iowa state average of Grade D. It ranks #1 of 6 lakes in Union County by water quality score.
Water clarity (Secchi depth) sits at 2.7 feet. That signals heavy algae or sediment, often tied to high phosphorus from runoff. Algae levels (chlorophyll-a) measure 28.4 µg/L — elevated; risk of harmful algal bloom advisories increases at this concentration.
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