What is the cleanest lake in Marshall County, Oklahoma?

Carter Lake in Marshall County is the highest-rated lake in Marshall County, Oklahoma with an EPA water quality grade of NR.

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 Marshall County, Oklahoma

Carter Lake in Marshall County leads the rankings with a water quality grade of NR. Below are the top 1 cleanest monitored lakes in Marshall County, Oklahoma, ranked by EPA water quality score.

Ranked List

#	Lake	County	Grade	Clarity	Phosphorus	Algae
1	Carter Lake	Marshall	NR	-	-	-

Ranked List

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