What is the cleanest lake in Thunder Bay District County, Ontario?

Arrow Lake in Thunder Bay District County is the cleanest lake on the readings in Thunder Bay District County, Ontario with an EPA water-quality readings of — and 24 feet of water clarity.

How are these rankings calculated?

Nutrients and algae, total phosphorus, nitrogen, chlorophyll-a and turbidity, are read 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 Thunder Bay District County, Ontario

Arrow Lake in Thunder Bay District County leads the rankings on measured clarity and nutrients and 24 ft of clarity. Below are the top 50 cleanest monitored lakes in Thunder Bay District County, Ontario, ranked by EPA water quality score.

Ranked List

#	Lake	County	Clarity	Phosphorus	Algae
1	Arrow Lake	Thunder Bay District	—	24 ft	7.5 µg/L	-
2	Barnum Lake	Thunder Bay District	—	7.2 ft	9.2 µg/L	-
3	Bass Lake	Thunder Bay District	—	11.8 ft	8.3 µg/L	-
4	Beaverkit Lake	Thunder Bay District	—	2.6 ft	11.4 µg/L	-
5	Burk Lake	Thunder Bay District	—	9.8 ft	6 µg/L	-
6	Cloud Lake	Thunder Bay District	—	4.3 ft	23.9 µg/L	-
7	Cox Lake	Thunder Bay District	—	2 ft	51.3 µg/L	-
8	Cummins Lake	Thunder Bay District	—	5.2 ft	11.3 µg/L	-
9	Cushing Lake	Thunder Bay District	—	3.8 ft	21.1 µg/L	-
10	Deception Lake	Thunder Bay District	—	20.2 ft	5.8 µg/L	-
11	Elbow Lake	Thunder Bay District	—	9.5 ft	8.3 µg/L	-
12	Fodder Lake	Thunder Bay District	—	3.6 ft	13.1 µg/L	-
13	Greenpike Lake	Thunder Bay District	—	6.4 ft	8.3 µg/L	-
14	Greenwater Lake	Thunder Bay District	—	12.6 ft	13 µg/L	-
15	Ham Lake	Thunder Bay District	—	6.2 ft	11.3 µg/L	-
16	Howcum Lake	Thunder Bay District	—	5.7 ft	12.6 µg/L	-
17	Icarus Lake	Thunder Bay District	—	11.8 ft	9.2 µg/L	-
18	Iron Range Lake	Thunder Bay District	—	8.9 ft	7.7 µg/L	-
19	Island Lake	Thunder Bay District	—	12.6 ft	8.2 µg/L	-
20	Lac des Mille Lacs Lake	Thunder Bay District	—	4.3 ft	22.7 µg/L	-
21	Lenore Lake	Thunder Bay District	—	6.6 ft	12.3 µg/L	-
22	Little Cedar Lake	Thunder Bay District	—	6.2 ft	16.4 µg/L	-
23	Lottit Lake	Thunder Bay District	—	4.9 ft	11.8 µg/L	-
24	Lyne Lake	Thunder Bay District	—	9.8 ft	7.1 µg/L	-
25	Maccormack Lake	Thunder Bay District	—	6.2 ft	9.2 µg/L	-
26	Madalaine Lake	Thunder Bay District	—	6.6 ft	9.8 µg/L	-
27	Marks Lake	Thunder Bay District	—	6.9 ft	10.4 µg/L	-
28	Oliver Lake	Thunder Bay District	—	19 ft	5.2 µg/L	-
29	One Island Lake	Thunder Bay District	—	6.1 ft	8 µg/L	-
30	Peterkin Lake	Thunder Bay District	—	7.5 ft	12.2 µg/L	-
31	Reta Lake	Thunder Bay District	—	6.1 ft	7.4 µg/L	-
32	Roundtable Lake	Thunder Bay District	—	7.9 ft	8.8 µg/L	-
33	Shaco Lake	Thunder Bay District	—	6.4 ft	8 µg/L	-
34	Shebandowan Lake	Thunder Bay District	—	8 ft	12 µg/L	-
35	Shebandowan Lake	Thunder Bay District	—	9.2 ft	7.9 µg/L	-
36	Silver Lake	Thunder Bay District	—	16.1 ft	5.1 µg/L	-
37	Spike Lake	Thunder Bay District	—	7.4 ft	10.5 µg/L	-
38	Sunbow Lake	Thunder Bay District	—	7.5 ft	8.9 µg/L	-
39	Sunset Lake	Thunder Bay District	—	15.6 ft	7.9 µg/L	-
40	Superior Lake	Thunder Bay District	—	10.8 ft	5.2 µg/L	-
41	Surprise Lake	Thunder Bay District	—	5.6 ft	10.8 µg/L	-
42	Tomlinson Lake	Thunder Bay District	—	7.5 ft	9.1 µg/L	-
43	Tornroos Lake	Thunder Bay District	—	9.2 ft	9.3 µg/L	-
44	Trout Lake	Thunder Bay District	—	5.9 ft	10.5 µg/L	-
45	Upper Hunter'S Lake	Thunder Bay District	—	9.5 ft	6.8 µg/L	-
46	Walker Lake	Thunder Bay District	—	9 ft	5.4 µg/L	-
47	Warnica Lake	Thunder Bay District	—	9.5 ft	12.9 µg/L	-
48	Wartman Lake	Thunder Bay District	—	4.9 ft	9 µg/L	-
49	White Lake	Thunder Bay District	—	11.2 ft	8.2 µg/L	-
50	Whitefish Lake	Thunder Bay District	—	8 ft	10.7 µg/L	-

Ranked List

More Answers for Thunder Bay District County, Ontario