Cleanest Lakes in Union County, Iowa
Three Mile Lake in Union County leads the rankings with a water quality grade of D and 2.7 ft of clarity. Below are the top 6 cleanest monitored lakes in Union County, Iowa, ranked by EPA water quality score.
Ranked List
| # | Lake | County | Grade | Clarity | Phosphorus | Algae |
|---|---|---|---|---|---|---|
| 1 | Three Mile Lake | Union | D | 2.7 ft | - | 28.4 µg/L |
| 2 | Thayer Lake | Union | D | 3.5 ft | - | 34.3 µg/L |
| 3 | Twelve Mile Lake | Union | F | 2.4 ft | - | 45 µg/L |
| 4 | Green Valley Lake | Union | F | 1.5 ft | - | 61.7 µg/L |
| 5 | Summit Lake | Union | F | 1.4 ft | - | 45.7 µg/L |
| 6 | Mckinley Lake | Union | F | 1 ft | - | 69.3 µg/L |