Nitrate Contamination

Nitrate in Minnesota Drinking Water

Ranked by nitrate violation count · Data from EPA SDWIS & UCMR

Cities Tested

Has Violations

100%

% Has Violations

2.4 violations

State Avg

▼ 0% vs national

vs National

217

Health Violations

Analysis

Nitrate in Minnesota: what the data shows

Minnesota has 90 cities with nitrate-related violations. The EPA MCL for nitrate is 10 mg/L (measured as nitrogen). The state has 90 cities with at least one nitrate violation. Nitrate is the most common groundwater contaminant in the United States. It enters water supplies primarily through agricultural fertilizer runoff, septic system leaching, and animal feedlot operations. Rural and agricultural communities face the highest risk. The primary acute health concern is methemoglobinemia ("blue baby syndrome") in infants under six months. Emerging research also links chronic nitrate exposure to thyroid disease, certain cancers, and adverse birth outcomes. Reverse osmosis, ion exchange, and distillation can remove nitrate from drinking water — standard carbon filters do not.

Comparison

Cities exceeding 10 mg/L EPA MCL

Minnesota

100%

90 of 90 cities

← = Exactly at national rate

National avg

100%

8001 of 8001 cities

City Map

Nitrate data across Minnesota

Each dot is a city with nitrate violation data. Cities with at least one nitrate-related violation are highlighted. Size reflects population served.

Worst Offenders

Top 10 cities by nitrate level in Minnesota

Highest Nitrate levels (violations)

All Cities

All Minnesota cities ranked by nitrate level

#	City	Level	Violations?	Violations	Grade
1	White Earth	19 violations	Yes	20	D
2	Detroit Lakes	14 violations	Yes	36	C-
3	Austin	8 violations	Yes	0	B+
4	Monticello	8 violations	Yes	6	B
5	Red Lake	8 violations	Yes	4	D+
6	Park Rapids	7 violations	Yes	9	A
7	St. Louis Park	6 violations	Yes	5	A-
8	Henning	6 violations	Yes	9	A-
9	Brainerd	5 violations	Yes	3	B+
10	Royalton	5 violations	Yes	18	B-
11	Prior Lake	4 violations	Yes	1	B+
12	Shakopee	4 violations	Yes	7	B
13	Mankato	4 violations	Yes	8	F
14	Bemidji	4 violations	Yes	7	C
15	Onamia	4 violations	Yes	1	D
16	Nett Lake	4 violations	Yes	40	D
17	Clara City	4 violations	Yes	3	A
18	Edgerton	4 violations	Yes	6	A
19	Minneapolis	3 violations	Yes	2	B-
20	Thief River Falls	3 violations	Yes	20	B-
21	Cold Spring	3 violations	Yes	10	A
22	Lewiston	3 violations	Yes	6	A
23	Grand Portage	3 violations	Yes	23	F
24	St. Cloud	2 violations	Yes	2	A-
25	Cottage Grove	2 violations	Yes	4	A-
26	Hastings	2 violations	Yes	8	C+
27	Stillwater	2 violations	Yes	8	C+
28	Grand Rapids	2 violations	Yes	1	B+
29	Welch	2 violations	Yes	0	B+
30	Lindstrom	2 violations	Yes	1	A-
31	Excelsior	2 violations	Yes	3	A
32	Lexington	2 violations	Yes	7	B+
33	Warroad	2 violations	Yes	5	B+
34	Crosby	2 violations	Yes	2	B+
35	Adrian	2 violations	Yes	1	A
36	Deerwood	2 violations	Yes	1	A
37	Sabin	2 violations	Yes	2	A-
38	St. Paul	1 violations	Yes	5	B-
39	Woodbury	1 violations	Yes	0	B+
40	Edina	1 violations	Yes	1	B+
41	Inver Grove Heights	1 violations	Yes	37	D
42	Chaska	1 violations	Yes	2	B+
43	Farmington	1 violations	Yes	0	A-
44	Northfield	1 violations	Yes	0	A-
45	New Brighton	1 violations	Yes	1	A
46	Hibbing	1 violations	Yes	1	C
47	Hutchinson	1 violations	Yes	0	A
48	Lake Benton	1 violations	Yes	1	A-
49	Cloquet	1 violations	Yes	0	A-
50	Sauk Rapids	1 violations	Yes	2	B+
51	Fairmont	1 violations	Yes	3	A-
52	Litchfield	1 violations	Yes	3	A-
53	Jordan	1 violations	Yes	1	A
54	Princeton	1 violations	Yes	0	A-
55	Morton	1 violations	Yes	0	C+
56	Melrose	1 violations	Yes	3	A
57	Cass Lake	1 violations	Yes	17	C-
58	Milaca	1 violations	Yes	0	B+
59	Sandstone	1 violations	Yes	2	A-
60	Albany	1 violations	Yes	2	B+
61	Hawley	1 violations	Yes	1	A-
62	Clearwater	1 violations	Yes	0	A-
63	Slayton	1 violations	Yes	1	A-
64	Waterville	1 violations	Yes	0	A
65	Avon	1 violations	Yes	5	B-
66	Richmond	1 violations	Yes	3	A
67	Preston	1 violations	Yes	0	B+
68	Hayfield	1 violations	Yes	0	A
69	Ham Lake	1 violations	Yes	3	B+
70	Shafer	1 violations	Yes	2	A
71	Goodhue	1 violations	Yes	0	A
72	Atwater	1 violations	Yes	0	A+
73	Tyler	1 violations	Yes	0	A
74	Baudette	1 violations	Yes	1	A-
75	Sebeka	1 violations	Yes	1	A
76	Battle Lake	1 violations	Yes	1	A
77	Henderson	1 violations	Yes	1	A
78	Tower	1 violations	Yes	3	A-
79	Isle	1 violations	Yes	1	B+
80	Clarkfield	1 violations	Yes	0	A-
81	Westbrook	1 violations	Yes	1	A
82	Twin Valley	1 violations	Yes	0	A
83	Kasota	1 violations	Yes	8	A
84	Clear Lake	1 violations	Yes	1	A-
85	Randall	1 violations	Yes	1	A
86	Balaton	1 violations	Yes	0	A-
87	Jasper	1 violations	Yes	1	A-
88	Barnum	1 violations	Yes	0	A-
89	Clinton	1 violations	Yes	2	A-
90	Verndale	1 violations	Yes	2	A+

FAQ

Frequently asked questions about nitrate in Minnesota

Is nitrate in Minnesota tap water dangerous?

Yes — 90 cities in Minnesota have nitrate-related violations. The EPA MCL is 10 mg/L. Nitrate is especially dangerous for infants under six months, where it can cause methemoglobinemia ("blue baby syndrome"). Adults face lower acute risk, but chronic exposure is linked to thyroid disease and certain cancers.

How can I remove nitrate from my drinking water?

Reverse osmosis, ion exchange, and distillation are effective at removing nitrate. Standard carbon filters (including most pitcher and faucet-mount filters) do NOT remove nitrate. If you rely on a private well in an agricultural area, have your water tested annually for nitrate.

What causes high nitrate levels in Minnesota water?

Nitrate contamination comes primarily from agricultural fertilizer runoff, septic system leaching, and animal feedlot operations. Rural communities near intensive farming are most at risk. Shallow wells are particularly vulnerable. Heavy rainfall can spike nitrate levels as it washes fertilizer into groundwater and surface water supplies.

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