What is the cleanest lake in Adair County, Iowa?

Mormon Trail Lake in Adair County is the highest-rated lake in Adair County, Iowa with an EPA water quality grade of B and 6.2 feet of water clarity.

How are these rankings calculated?

Lakes are graded A through F on nutrients and algae — total phosphorus, nitrogen, chlorophyll-a, and turbidity — against EPA National Lakes Assessment 2022 condition classes for that lake’s ecoregion. Water clarity (Secchi depth) is measured and shown; it is not the letter. Lakes without enough recent samples are UNRATED, not given an F. Source data comes from the EPA Water Quality Portal.

Cleanest Lakes in Adair County, Iowa

Mormon Trail Lake in Adair County leads the rankings with a water quality grade of B and 6.2 ft of clarity. Below are the top 5 cleanest monitored lakes in Adair County, Iowa, ranked by EPA water quality score.

Ranked List

#	Lake	County	Grade	Clarity	Phosphorus	Algae
1	Mormon Trail Lake	Adair	B	6.2 ft	25 µg/L	9.7 µg/L
2	Nodaway Lake	Adair	D	2.8 ft	57 µg/L	27.6 µg/L
3	Greenfield Lake	Adair	F	2.1 ft	113 µg/L	53.8 µg/L
4	Meadow Lake	Adair	F	1.7 ft	99 µg/L	53.1 µg/L
5	Lake Orient	Adair	F	1.3 ft	674 µg/L	92.2 µg/L

Ranked List

More Answers for Adair County, Iowa