South Dakota Water Quality — 137 Cities Tested

Analysis

South Dakota water quality overview

South Dakota's drinking water quality is good overall, with an average score of 81.6 out of 100 across 137 cities tested. The median score is 86, serving a total population of 917,093 residents. 85% 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 137 cities tested (31%). 1 city exceeds the 2024 EPA maximum contaminant levels. The state relies on a mix of water sources: 78 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

31% of tested cities have PFAS in their water supply.

113 cities

Health Violations

22,964 total violations recorded, 136 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: 39 C: 10 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

137 cities in South Dakota

Full rankings →

#	City	Grade	Score	Population	Violations
1	Hamill	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	Goodwin	A	92.3	4K	5
20	De Smet	A	92.3	1K	53
21	Bridgewater	A	92.3	511	69
22	Mina	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	8K	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	699	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	15K	48
62	Newell	A-	87.3	2K	59
63	Brandon	A-	87.2	11K	20
64	Castlewood	A-	86.6	698	69
65	Avon	A-	86.5	590	19
66	Fulton	A-	86.3	3K	5
67	Ridgeview	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	Corsica	B+	84.5	561	18
79	Fort Pierre	B+	84.4	2K	29
80	Milbank	B+	84.2	9K	8
81	Whitewood	B+	84.1	1K	164
82	Emery	B+	83.8	3K	16
83	Mission	B+	83.8	2K	14
84	Garretson	B+	83.8	1K	67
85	Howard	B+	83.6	848	14
86	Wessington Springs	B+	83.1	895	8
87	Worthing	B+	82.8	939	89
88	White	B+	82.8	592	33
89	Egan	B+	82.5	7K	114
90	Clear Lake	B+	82.5	1K	10
91	Parkston	B+	82.4	2K	21
92	Wakonda	B+	81.8	7K	172
93	Mobridge	B+	81.5	3K	83
94	Lower Brule	B+	81	2K	101
95	Viborg	B+	80.7	814	20
96	Stephan	B+	80	516	27
97	Faulkton	B	79.6	1K	177
98	Eureka	B	79.4	813	11
99	Selby	B	79.4	645	32
100	Kimball	B	79.3	3K	53
101	Woonsocket	B	79.3	618	62
102	Platte	B	79.2	1K	12
103	Belle Fourche	B	79.1	6K	228
104	Lake Andes	B	78.8	7K	126
105	Lake Preston	B	78.8	589	17
106	Hermosa	B	77.5	568	70
107	Alexandria	B	76.5	649	8
108	Scotland	B	76.1	935	159
109	Beresford	B	76	8K	213
110	Agency Village	B	76	2K	166
111	Lead	B	75.6	3K	261
112	Eagle Butte	B-	74.5	6K	92
113	Yankton	B-	72.8	16K	123
114	Box Elder	B-	72.7	14K	145
115	Hot Springs	B-	72.7	5K	241
116	Batesland	B-	70.4	3K	347
117	Miller	C+	69	14K	275
118	New Underwood	C+	68.7	923	163
119	Fort Thompson	C	64.8	2K	351
120	Arlington	C	64.7	13K	305
121	Flandreau	C	63.9	3K	147
122	Martin	C	62.6	2K	401
123	Britton	C	62	7K	381
124	Deadwood	C	61	1K	212
125	Huron	C	60.2	14K	530
126	Sioux Falls	C-	58.2	223K	181
127	Black Hawk	D+	51	9K	2565
128	Sturgis	D+	50.5	8K	828
129	Edgemont	D+	50	750	424
130	Wagner	D	49	3K	126
131	Spearfish	D	47.8	14K	1320
132	Brookings	D	46.2	24K	798
133	Pine Ridge	F	43.2	25K	726
134	Rosebud	F	42.2	14K	252
135	Aberdeen	F	41.8	51K	2732
136	Piedmont	F	39.5	5K	710
137	Rapid City	F	38.7	93K	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 1 city · avg 87.4 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 7 cities · avg 76.7 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 1 city · avg 72.8

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+ (81.6/100). 85% 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 Hamill (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 137 cities tested positive for PFAS "forever chemicals" (31%). 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