Nitrate Contamination

Nitrate in South Dakota Drinking Water

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

Cities Tested

Has Violations

100%

% Has Violations

4.2 violations

State Avg

▼ 0% vs national

vs National

117

Health Violations

Analysis

Nitrate in South Dakota: what the data shows

South Dakota has 83 cities with nitrate-related violations. The EPA MCL for nitrate is 10 mg/L (measured as nitrogen). The state has 83 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

South Dakota

100%

83 of 83 cities

← = Exactly at national rate

National avg

100%

8001 of 8001 cities

City Map

Nitrate data across South Dakota

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 South Dakota

Highest Nitrate levels (violations)

All Cities

All South Dakota cities ranked by nitrate level

#	City	Level	Violations?	Violations	Grade
1	Aberdeen	37 violations	Yes	197	F
2	Rapid City	27 violations	Yes	349	F
3	Black Hawk	27 violations	Yes	350	D+
4	Pine Ridge	21 violations	Yes	138	F
5	Spearfish	18 violations	Yes	166	D
6	Estelline	16 violations	Yes	22	A-
7	Agency Village	11 violations	Yes	8	B
8	Fort Thompson	9 violations	Yes	17	C
9	Sturgis	8 violations	Yes	156	D+
10	Hot Springs	7 violations	Yes	22	B-
11	Lead	7 violations	Yes	18	B
12	Huron	6 violations	Yes	9	C
13	Miller	6 violations	Yes	34	C+
14	Britton	6 violations	Yes	37	C
15	Lake Andes	6 violations	Yes	12	B
16	Whitewood	6 violations	Yes	0	B+
17	Arlington	5 violations	Yes	5	C
18	Piedmont	5 violations	Yes	171	F
19	Flandreau	5 violations	Yes	19	C
20	Brookings	4 violations	Yes	11	D
21	Batesland	4 violations	Yes	21	B-
22	Lower Brule	4 violations	Yes	7	B+
23	Martin	4 violations	Yes	28	C
24	Deadwood	4 violations	Yes	84	C
25	Rapid City	4 violations	Yes	18	C-
26	Fort Meade	4 violations	Yes	2	A-
27	Edgemont	4 violations	Yes	46	D+
28	Rosebud	3 violations	Yes	18	F
29	Beresford	3 violations	Yes	19	B
30	Belle Fourche	3 violations	Yes	7	B
31	Springfield	3 violations	Yes	12	A-
32	Faulkton	3 violations	Yes	25	B
33	Scotland	3 violations	Yes	7	B
34	Wall	3 violations	Yes	7	A-
35	Sioux Falls	2 violations	Yes	30	C-
36	Mitchell	2 violations	Yes	6	A-
37	Yankton	2 violations	Yes	29	B-
38	Brandon	2 violations	Yes	0	A-
39	Winner	2 violations	Yes	4	A
40	Wakonda	2 violations	Yes	4	B+
41	Mobridge	2 violations	Yes	3	B+
42	Volga	2 violations	Yes	0	A
43	Elk Point	2 violations	Yes	1	A
44	Gettysburg	2 violations	Yes	0	A
45	Highmore	2 violations	Yes	11	A-
46	Pierre	1 violations	Yes	8	A-
47	Dell Rapids	1 violations	Yes	2	A
48	Box Elder	1 violations	Yes	17	B-
49	Tabor	1 violations	Yes	3	A-
50	Tabor	1 violations	Yes	4	A-
51	Harrisburg	1 violations	Yes	0	A
52	Murdo	1 violations	Yes	2	A-
53	Milbank	1 violations	Yes	0	B+
54	Egan	1 violations	Yes	11	B+
55	Eagle Butte	1 violations	Yes	18	B-
56	Parker	1 violations	Yes	3	A-
57	Winner	1 violations	Yes	1	A+
58	Clark	1 violations	Yes	2	A-
59	Kimball	1 violations	Yes	8	B
60	Clark	1 violations	Yes	3	B+
61	Emery	1 violations	Yes	2	B+
62	Canton	1 violations	Yes	0	A+
63	North Sioux City	1 violations	Yes	0	A
64	Chamberlain	1 violations	Yes	11	A-
65	Emery	1 violations	Yes	0	A-
66	Newell	1 violations	Yes	38	A-
67	Eagle Butte	1 violations	Yes	15	A-
68	Fort Pierre	1 violations	Yes	5	B+
69	Philip	1 violations	Yes	24	A
70	Crooks	1 violations	Yes	0	A
71	Salem	1 violations	Yes	5	A
72	Gregory	1 violations	Yes	2	A
73	Aurora	1 violations	Yes	3	A
74	New Underwood	1 violations	Yes	63	C+
75	Hill City	1 violations	Yes	4	A-
76	Valley Springs	1 violations	Yes	5	A-
77	Elkton	1 violations	Yes	10	A-
78	Plankinton	1 violations	Yes	13	A
79	Woonsocket	1 violations	Yes	6	B
80	Mclaughlin	1 violations	Yes	0	A-
81	Kadoka	1 violations	Yes	8	A
82	White River	1 violations	Yes	5	A-
83	Stephan	1 violations	Yes	1	B+

FAQ

Frequently asked questions about nitrate in South Dakota

Is nitrate in South Dakota tap water dangerous?

Yes — 83 cities in South Dakota 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 South Dakota 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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