Recently Monitored Lakes — Latest EPA Water Quality Samples

#	Lake	County	State	Grade	Clarity	Depth	Last Sampled
1	Cowanesque Lake	Tioga	Pennsylvania	NR	-	-	2026-09-07
2	Prompton Lake	Wayne	Pennsylvania	NR	-	-	2026-09-07
3	Curwensville Lake	Clearfield	Pennsylvania	NR	-	-	2026-09-07
4	Mahoning Creek Lake	Indiana	Pennsylvania	NR	-	-	2026-09-07
5	Kettle Creek Lake	Clinton	Pennsylvania	D	-	-	2026-09-07
6	Blue Marsh Lake	Berks	Pennsylvania	NR	-	-	2026-09-07
7	Shenango River Lake	Mercer	Pennsylvania	D	-	-	2026-09-07
8	Glendale Lake	Cambria	Pennsylvania	NR	-	-	2026-09-07
9	Struble Lake	Chester	Pennsylvania	F	-	-	2026-09-07
10	East Branch Clarion River Lake	Elk	Pennsylvania	NR	-	-	2026-09-07
11	Beltzville Lake	Carbon	Pennsylvania	NR	-	-	2026-09-07
12	Foster Joseph Sayers Lake	Centre	Pennsylvania	F	-	-	2026-09-07
13	Woodcock Creek Lake	Crawford	Pennsylvania	NR	-	-	2026-09-07
14	Crooked Creek Lake	Armstrong	Pennsylvania	C	-	-	2026-09-07
15	Pike Lake	Kosciusko	Indiana	C	1.9 ft	-	2026-09-07
16	Hamilton Lake	Steuben	Indiana	NR	-	-	2026-09-07
17	Brookville Lake	Union	Indiana	C	-	-	2026-09-07
18	Cagles Mill Lake	Owen	Indiana	D	-	-	2026-09-07
19	Waldron Lake	Noble	Indiana	F	-	-	2026-09-07
20	Sylvan Lake	Noble	Indiana	NR	-	-	2026-09-07
21	Pennask Lake	Nicola River	British Columbia	NR	8.4 ft	-	2026-08-27
22	Windermere Lake	Columbia River	British Columbia	NR	14.1 ft	-	2026-08-26
23	Lillian Lake	Columbia River	British Columbia	NR	17.7 ft	-	2026-08-25
24	Babine Lake	Babine Lake	British Columbia	NR	17.4 ft	-	2026-08-25
25	Hotel Lake	Jervis Inlet	British Columbia	NR	19.6 ft	-	2026-08-25
26	Burns Lake	Francois Lake	British Columbia	NR	6.6 ft	-	2026-08-25
27	Columbia Lake	Columbia River	British Columbia	NR	14 ft	-	2026-08-25
28	Tabor Lake	Tabor River	British Columbia	NR	7.2 ft	-	2026-08-25
29	Arrow Lake	Upper Arrow Lake	British Columbia	NR	-	-	2026-08-25
30	Premier Lake	St. Mary River	British Columbia	NR	32.8 ft	-	2026-08-25
31	Bridge Lake	Bridge Creek	British Columbia	NR	19.5 ft	-	2026-08-24
32	Arrow Lake	Lower Arrow Lake	British Columbia	NR	-	-	2026-08-24
33	Gun Lake	Seton Lake	British Columbia	NR	58.4 ft	-	2026-08-24
34	Moberly Lake	Upper Peace River	British Columbia	NR	5.9 ft	-	2026-08-20
35	Elk Lake	Victoria	British Columbia	NR	13.8 ft	-	2026-08-20
36	Alice Lake	Squamish	British Columbia	NR	-	-	2026-08-20
37	Okanagan Lake	Okanagan River	British Columbia	NR	19.3 ft	-	2026-08-19
38	Alouette Reservoir	Lower Fraser	British Columbia	NR	-	-	2026-08-19
39	Charlie Lake	Lower Beatton River	British Columbia	NR	6.1 ft	-	2026-08-19
40	Muncho Lake	Liard River	British Columbia	NR	31.5 ft	-	2026-08-18
41	Bootjack Lake	Quesnel River	British Columbia	NR	-	-	2026-08-18
42	Nicola Lake	Lower Nicola River	British Columbia	NR	11.8 ft	-	2026-08-18
43	Polley Lake	Quesnel River	British Columbia	NR	-	-	2026-08-18
44	Kootenay Lake	Kootenay Lake	British Columbia	NR	-	-	2026-08-17
45	Shuswap Lake	Shuswap Lake	British Columbia	NR	20.7 ft	-	2026-08-13
46	Naltesby Lake	Lower Chilako River	British Columbia	NR	8.6 ft	-	2026-08-13
47	Cluculz Lake	Nechako River	British Columbia	NR	13.1 ft	-	2026-08-12
48	Nadsilnich Lake	Lower Chilako River	British Columbia	NR	5.3 ft	-	2026-08-12
49	Williams Lake	San Jose River	British Columbia	NR	4 ft	-	2026-08-11
50	Puntchesakut Lake	Narcosli Creek	British Columbia	NR	6.4 ft	-	2026-08-11
51	Horse Lake	Bridge Creek	British Columbia	NR	15.8 ft	-	2026-08-10
52	Strohn Lake	Kshwan River	British Columbia	NR	1.2 ft	-	2026-08-06
53	Lizard Lake	San Juan River	British Columbia	NR	25.4 ft	-	2026-08-06
54	Langford Lake	Victoria	British Columbia	NR	12.1 ft	-	2026-08-05
55	Swan Lake	Victoria	British Columbia	NR	3.4 ft	-	2026-08-05
56	Quamichan Lake	Cowichan	British Columbia	NR	5.6 ft	-	2026-08-04
57	Tyhee Lake	Bulkley River	British Columbia	NR	13.1 ft	-	2026-08-04
58	Tachick Lake	Nechako River	British Columbia	NR	4.9 ft	-	2026-07-29
59	Stump Lake	Squamish	British Columbia	NR	-	-	2026-07-23
60	Edith Lake	Squamish	British Columbia	NR	-	-	2026-07-23
61	Fawn Lake	Squamish	British Columbia	NR	-	-	2026-07-23
62	Smoky Lake	Iron	Michigan	B	24 ft	-	2026-07-19
63	Bass Lake	Barron	Wisconsin	B	10 ft	14 ft	2026-07-14
64	Lower Spring Lake	Jefferson	Wisconsin	C	4 ft	-	2026-07-14
65	Gile Flowage Lake	Iron	Wisconsin	C	4.6 ft	-	2026-07-14
66	Bear Lake	Waupaca	Wisconsin	B	11 ft	62 ft	2026-07-13
67	Legend Lake	Menominee	Wisconsin	B	10 ft	-	2026-07-13
68	Red Cedar Lake	Jefferson	Wisconsin	B	4 ft	6 ft	2026-07-13
69	Pipe Lake	Polk	Wisconsin	B	11.5 ft	68 ft	2026-07-13
70	Jordan Lake	Adams	Wisconsin	B	13 ft	92 ft	2026-07-13
71	Crystal Lake	Sheboygan	Wisconsin	B	20 ft	-	2026-07-13
72	Lily Lake	Forest	Wisconsin	NR	11.5 ft	24 ft	2026-07-13
73	Lower Nashotah Lake	Waukesha	Wisconsin	B	9 ft	43 ft	2026-07-13
74	Johnson Lake	Burnett	Wisconsin	B	12.2 ft	23 ft	2026-07-13
75	Red Lake	Douglas	Wisconsin	B	12 ft	37 ft	2026-07-13
76	Lake Helen	Portage	Wisconsin	B	8 ft	20 ft	2026-07-13
77	Skice Lake	Menominee	Wisconsin	NR	7 ft	-	2026-07-13
78	Smith Lake	Washington	Wisconsin	NR	4 ft	5 ft	2026-07-13
79	Catfish Lake	Vilas	Wisconsin	NR	5.5 ft	30 ft	2026-07-13
80	Round Lake	Burnett	Wisconsin	D	5.2 ft	27 ft	2026-07-12
81	Round Lake	Polk	Wisconsin	NR	11.5 ft	26 ft	2026-07-12
82	Marl Lake	Waushara	Wisconsin	B	12 ft	35 ft	2026-07-12
83	Rosalind Lake	Vilas	Wisconsin	B	19.3 ft	-	2026-07-12
84	Big Eau Pleine Lake	Marathon	Wisconsin	D	1.5 ft	-	2026-07-12
85	Lake Lucerne	Forest	Wisconsin	B	18.7 ft	73 ft	2026-07-12
86	Lilly Lake	Kenosha	Wisconsin	B	13.5 ft	22 ft	2026-07-12
87	Potato Lake	Rusk	Wisconsin	NR	3 ft	-	2026-07-12
88	Papoose Lake	Vilas	Wisconsin	B	15 ft	65 ft	2026-07-12
89	Duck Lake	Langlade	Wisconsin	C	3.7 ft	19 ft	2026-07-12
90	Dynamite Lake	Langlade	Wisconsin	NR	3 ft	28 ft	2026-07-12
91	Mcginnis Lake	Adams	Wisconsin	B	7 ft	28 ft	2026-07-12
92	Glisezinski Lake	Portage	Wisconsin	B	9 ft	11 ft	2026-07-12
93	Great Bass Lake	Oneida	Wisconsin	B	10.5 ft	24 ft	2026-07-12
94	Elsie Lake	Vilas	Wisconsin	NR	16 ft	22 ft	2026-07-12
95	Tainter Lake	Dunn	Wisconsin	D	3.7 ft	37 ft	2026-07-11
96	Spencer Lake	Waupaca	Wisconsin	B	8.5 ft	53 ft	2026-07-11
97	Lake Metonga	Forest	Wisconsin	B	22 ft	79 ft	2026-07-11
98	Moen Lake	Oneida	Wisconsin	C	2.8 ft	11 ft	2026-07-11
99	Loveless Lake	Polk	Wisconsin	C	8.5 ft	20 ft	2026-07-11
100	Bass Lake	Waupaca	Wisconsin	NR	10.5 ft	35 ft	2026-07-10

Source: EPA Water Quality Portal. Sample dates reflect when monitoring crews collected water samples — typically there is a multi-month lag before the data appears in the federal portal.