South Dakota Water Quality — 141 Cities Tested

Analysis

South Dakota water quality overview

South Dakota's drinking water quality is good overall, with an average score of 81.3 out of 100 across 141 cities tested. The median score is 86, serving a total population of 975,594 residents. 84% of cities earned an A or B grade, indicating broadly strong water quality infrastructure across the state. PFAS "forever chemicals" were detected in 42 of 141 cities tested (30%). 1 city exceeds the 2024 EPA maximum contaminant levels. The state relies on a mix of water sources: 82 cities use groundwater while 58 draw from surface water such as rivers, lakes, and reservoirs.

Key Concerns

Issues to watch in South Dakota

42 cities

PFAS Detected

30% of tested cities have PFAS in their water supply.

117 cities

Health Violations

23,802 total violations recorded, 140 with unresolved issues.

5 cities

Failing Systems

Received a grade of F, indicating serious water quality issues.

Contaminant Data

Explore contaminants in South Dakota

Lead in South Dakota → Ranked by 90th percentile level (ppb) PFAS in South Dakota → Ranked by compounds detected Copper in South Dakota → Ranked by 90th percentile level (mg/L)

More contaminants tested in South Dakota

HAA5 → Chromium-6 → Arsenic → Nitrate → Strontium → Manganese → Vanadium → Chlorate → Molybdenum → Lithium →

State context

2

Superfund sites in South Dakota

EPA National Priorities List

93.8%

of South Dakota residents on fluoridated water

CDC, 2020

2,554,329

lbs released to surface water

Top 10 TRI facilities, 2023

20.4%

of South Dakota domestic wells exceed EPA arsenic limit

USGS, 401 samples · 10 µg/L MCL

Domestic well chemistry

Private-well water in South Dakota

Based on USGS Powell Domestic-Well Database — 1,541 private wells sampled across South Dakota. These wells are not regulated by the EPA; if you draw your tap from a private well, the public-system grade above does not apply to you.

4.8 µg/L

Median arsenic in domestic wells

P90 20.0 µg/L · max 110.0 µg/L

380 µg/L

Median manganese in domestic wells

55.1% exceed 300 µg/L aesthetic limit

Industrial pollution

Top industrial water polluters in South Dakota

Industrial polluters nearby

The 10 facilities reporting the most pounds released to surface water in South Dakota, 2023.

Total reported releases to surface water: 2,554,329 lbs

Facility	Top chemical	To surface water (lbs/yr)
SMITHFIELD PACKAGED MEATS CORP - SIOUX FALLS Food · UNITED GLOBAL FOODS US HOLDINGS INC SIOUX FALLS, SD57117	Nitrate compounds (water dissociable; reportable only when in aqueous solution)	2,544,574
VALLEY QUEEN CHEESE FACTORY INC. Food · NA MILBANK, SD57252	Nitrate compounds (water dissociable; reportable only when in aqueous solution)	5,922
WHARF RESOURCES Metal Mining · COEUR MINING INC LEAD, SD57754	Nitrate compounds (water dissociable; reportable only when in aqueous solution)	3,828
CHS CORSON FEED Food · CHS INC CORSON, SD57005	Zinc compounds	5

Source: EPA Toxic Release Inventory (TRI) 2023

Test your own tap

Get your South Dakota water tested

City-level data shows the source and infrastructure picture — but lead and other home-plumbing issues only show up at your tap. Find a state-certified lab, see what to test for, and what it costs.

Grade Distribution

How South Dakota cities scored

A: 77 B: 42 C: 11 D: 6 F: 5

Best Cities

Worst Cities

City Map

Water quality across South Dakota

Each dot is a city, colored by its water quality grade. Size reflects population served. Click any city to view its full water report.

All Cities

141 cities in South Dakota

Full rankings →

#	City	Grade	Score	Population	Violations
1	Winner	A+	95.8	5K	58
2	Madison	A+	95.5	6K	35
3	Canton	A+	95.2	3K	32
4	Elk Point	A	94.5	2K	42
5	Crooks	A	94.3	1K	49
6	Lake Norden	A	94.3	554	7
7	Hartford	A	94	3K	14
8	Lennox	A	93.9	3K	9
9	Tea	A	93.7	7K	11
10	Winner	A	93.6	8K	71
11	Dell Rapids	A	93.5	17K	13
12	Colman	A	93.5	634	54
13	Tyndall	A	93.3	1K	5
14	Harrisburg	A	93.2	10K	8
15	Groton	A	92.8	1K	7
16	Aurora	A	92.8	1K	13
17	Vermillion	A	92.5	12K	3
18	Sisseton	A	92.5	2K	6
19	Watertown	A	92.3	4K	5
20	De Smet	A	92.3	1K	53
21	Bridgewater	A	92.3	511	69
22	Aberdeen	A	92.1	863	20
23	Kadoka	A	92	543	57
24	Philip	A	91.8	2K	35
25	Tripp	A	91.8	575	93
26	Baltic	A	91.7	1K	33
27	Colton	A	91.7	738	48
28	Burke	A	91.6	575	3
29	Gregory	A	91.4	1K	35
30	Lemmon	A	91.4	1K	32
31	Ellsworth Afb	A	91.2	9K	7
32	Plankinton	A	91.2	782	24
33	Gettysburg	A	91.1	1K	10
34	Watertown	A	91	27K	10
35	North Sioux City	A	91	3K	35
36	Custer	A	90.8	2K	40
37	Armour	A	90.7	698	6
38	Salem	A	90.5	1K	35
39	Volga	A	90.4	2K	8
40	Webster	A	90.2	2K	7
41	Dakota Dunes	A-	89.9	4K	3
42	Murdo	A-	89.8	9K	14
43	Valley Springs	A-	89.6	925	13
44	Canistota	A-	89.3	642	14
45	Mclaughlin	A-	89.2	569	5
46	Freeman	A-	89.1	1K	14
47	Onida	A-	88.7	658	66
48	Oral	A-	88.6	1K	64
49	Humboldt	A-	88.6	579	19
50	Mitchell	A-	88.5	19K	41
51	Highmore	A-	88.3	682	75
52	Menno	A-	88.3	614	8
53	Fort Meade	A-	88	800	67
54	Wall	A-	87.7	783	92
55	Springfield	A-	87.6	2K	25
56	White River	A-	87.6	533	27
57	Ipswich	A-	87.5	1K	18
58	Clark	A-	87.4	4K	85
59	Redfield	A-	87.4	2K	15
60	Elkton	A-	87.4	874	62
61	Pierre	A-	87.3	27K	48
62	Newell	A-	87.3	2K	59
63	Brandon	A-	87.2	11K	20
64	Castlewood	A-	86.6	698	69
65	Tabor	A-	86.5	14K	19
66	Emery	A-	86.3	3K	5
67	Eagle Butte	A-	86.2	2K	67
68	Hill City	A-	86.2	1K	104
69	Toronto	A-	86	6K	5
70	Parker	A-	86	5K	48
71	Estelline	A-	86	749	86
72	Tabor	A-	85.8	14K	15
73	Chamberlain	A-	85.7	3K	56
74	Bison	A-	85.7	780	48
75	Alcester	A-	85.5	820	12
76	Centerville	A-	85.3	918	74
77	Marion	A-	85.2	894	9
78	Clark	B+	84.5	3K	101
79	Corsica	B+	84.5	561	18
80	Fort Pierre	B+	84.4	2K	29
81	Milbank	B+	84.2	9K	8
82	Whitewood	B+	84.1	1K	164
83	Emery	B+	83.8	3K	16
84	Mission	B+	83.8	2K	14
85	Garretson	B+	83.8	1K	67
86	Howard	B+	83.6	848	14
87	Wessington Springs	B+	83.1	895	8
88	Beresford	B+	82.8	6K	89
89	White	B+	82.8	592	33
90	Toronto	B+	82.5	7K	10
91	Egan	B+	82.5	7K	114
92	Parkston	B+	82.4	2K	21
93	Wakonda	B+	81.8	7K	172
94	Mobridge	B+	81.5	3K	83
95	Lower Brule	B+	81	2K	101
96	Viborg	B+	80.7	814	20
97	Stephan	B+	80	516	27
98	Faulkton	B	79.6	1K	177
99	Eureka	B	79.4	813	11
100	Selby	B	79.4	645	32
101	Kimball	B	79.3	3K	53
102	Woonsocket	B	79.3	618	62
103	Platte	B	79.2	1K	12
104	Belle Fourche	B	79.1	6K	228
105	Lake Andes	B	78.8	7K	126
106	Lake Preston	B	78.8	589	17
107	Hermosa	B	77.5	663	70
108	Alexandria	B	76.5	649	8
109	Scotland	B	76.1	935	159
110	Beresford	B	76	8K	213
111	Agency Village	B	76	2K	166
112	Lead	B	75.6	4K	261
113	Rapid City	B	75	808	289
114	Eagle Butte	B-	74.5	6K	92
115	Yankton	B-	72.8	16K	123
116	Box Elder	B-	72.7	14K	145
117	Hot Springs	B-	72.7	5K	241
118	Gayville	B-	70.5	647	56
119	Batesland	B-	70.4	3K	347
120	Miller	C+	69	14K	275
121	New Underwood	C+	68.7	1K	163
122	Fort Thompson	C	64.8	2K	351
123	Arlington	C	64.7	13K	305
124	Flandreau	C	63.9	3K	147
125	Martin	C	62.6	2K	401
126	Britton	C	62	7K	381
127	Deadwood	C	61	1K	212
128	Huron	C	60.2	14K	530
129	Rapid City	C-	58.4	841	392
130	Sioux Falls	C-	58.2	228K	181
131	Black Hawk	D+	51	11K	2565
132	Sturgis	D+	50.5	8K	828
133	Edgemont	D+	50	750	424
134	Wagner	D	49	3K	126
135	Spearfish	D	47.8	14K	1320
136	Brookings	D	46.2	24K	798
137	Pine Ridge	F	43.2	25K	726
138	Rosebud	F	42.2	14K	252
139	Aberdeen	F	41.8	54K	2732
140	Piedmont	F	39.5	5K	710
141	Rapid City	F	38.7	96K	3413

Counties

Browse South Dakota counties

Aurora 2 cities · avg 85.3 Beadle 1 city · avg 60.2 Bennett 1 city · avg 62.6 Bon Homme 5 cities · avg 85.9 Brookings 8 cities · avg 79.1 Brown 3 cities · avg 65.5 Brule 1 city · avg 85.7 Butte 2 cities · avg 83.2 Charles Mix 3 cities · avg 69 Clark 2 cities · avg 86 Clay 2 cities · avg 87.2 Codington 1 city · avg 91 Corson 1 city · avg 89.2 Custer 2 cities · avg 84.2 Davison 1 city · avg 88.5 Day 1 city · avg 90.2 Dewey 2 cities · avg 80.3 Douglas 2 cities · avg 87.6 Edmunds 2 cities · avg 89.8 Fall River 3 cities · avg 70.4 Faulk 1 city · avg 79.6 Grant 1 city · avg 84.2 Gregory 2 cities · avg 91.5 Hamlin 4 cities · avg 89.8 Hanson 3 cities · avg 82.2 Hughes 2 cities · avg 78.2 Hutchinson 4 cities · avg 87.9 Hyde 1 city · avg 88.3 Jackson 1 city · avg 92 Jerauld 1 city · avg 83.1 Kingsbury 2 cities · avg 85.5 Lake 1 city · avg 95.5 Lawrence 4 cities · avg 67.1 Lincoln 6 cities · avg 89.1 Mccook 4 cities · avg 89.5 Mcpherson 1 city · avg 79.4 Meade 4 cities · avg 57.3 Mellette 1 city · avg 87.6 Miner 1 city · avg 83.6 Minnehaha 10 cities · avg 87.3 Moody 3 cities · avg 80 Pennington 9 cities · avg 74.5 Perkins 2 cities · avg 88.6 Potter 1 city · avg 91.1 Roberts 1 city · avg 92.5 Sanborn 1 city · avg 79.3 Shannon 1 city · avg 70.4 Spink 1 city · avg 87.4 Stanley 2 cities · avg 87.1 Sully 1 city · avg 88.7 Tripp 2 cities · avg 94.7 Turner 3 cities · avg 83.7 Union 4 cities · avg 90.2 Walworth 2 cities · avg 80.5 Yankton 2 cities · avg 71.7

ZIP Codes

Browse South Dakota by ZIP code

Look up water quality by ZIP code to find the systems serving your area.

View all South Dakota ZIP codes →

FAQ

Frequently asked questions about South Dakota's water

Is South Dakota's tap water safe to drink?

South Dakota's water quality varies by city. The statewide average grade is B+ (81.3/100). 84% of cities scored an A or B, while 8% received a D or F. Check your specific city for detailed results.

Which South Dakota cities have the best water quality?

The top-rated cities are Winner (A+), Madison (A+), Canton (A+). These cities scored highest based on violation history, lead levels, PFAS contamination, and regulatory compliance.

Which South Dakota cities have the worst water quality?

The lowest-rated cities are Rapid City (F), Piedmont (F), Aberdeen (F). We recommend residents in these areas consider water filtration and review their city's specific contaminant data.

How many South Dakota cities have PFAS in their water?

42 out of 141 cities tested positive for PFAS "forever chemicals" (30%). 1 city exceeds the 2024 EPA maximum contaminant levels. Reverse osmosis or activated carbon filters can help reduce PFAS exposure.

South Dakota Water Quality Report