South Dakota Tap Water Quality (2026)

South Dakota Tap Water Quality Report

221 cities analyzed • 778,464 people served

Updated September 2026 • Data from EWG & EPA SDWIS

221

Cities Analyzed

2.9

Avg Above Guidelines

778,464

Total Population Served

Best Water Quality

Sturgis (0 above guidelines)

Most Concerns

Hudson (13 above guidelines)

Most Common Contaminants in South Dakota

Contaminant	Found In	% of Cities
Total trihalomethanes (TTHMs) carcinogen	185 of 221	84%
Haloacetic acids (HAA5) carcinogen	164 of 221	74%
Barium*	107 of 221	48%
Fluoride*	81 of 221	37%
Lithium*	81 of 221	37%
Selenium*	72 of 221	33%
Antimony*	61 of 221	28%
Haloacetic acids (HAA9)* carcinogen	58 of 221	26%
Manganese*	56 of 221	25%
Molybdenum*	49 of 221	22%

City-by-City Water Quality Rankings

Ranked by number of contaminants above EWG health guidelines (most to fewest).

#	City	Detected	Above Guidelines	Above Legal	People Served
1	Hudson	22	13	0	369
2	Rapid City	16	7	0	78,836
3	Bison	9	7	0	470
4	Ellsworth Afb	17	7	0	0
5	Sioux Falls	14	6	0	201,650
6	Aberdeen	16	5	0	31,822
7	Watertown	13	5	0	22,162
8	Pierre	16	5	0	14,091
9	Webster	16	5	0	1,696
10	Groton	16	5	0	1,380
11	Ipswich	16	5	0	928
12	Eureka	16	5	0	814
13	Warner	16	5	0	452
14	Leola	16	5	0	434
15	Herreid	16	5	0	424
16	Bristol	16	5	0	288
17	Frederick	16	5	0	215
18	Roslyn	16	5	0	162
19	Conde	16	5	0	135
20	Eden	16	5	0	99
21	Bath	16	5	0	75
22	Grenville	16	5	0	48
23	Brentford	16	5	0	0
24	Pollock	16	5	0	0
25	Seneca	16	5	0	0
26	Redfield	16	5	0	0
27	Roscoe	16	5	0	0
28	Selby	16	5	0	0
29	Northville	16	5	0	0
30	Java	16	5	0	0
31	Hosmer	16	5	0	0
32	Doland	16	5	0	0
33	Bowdle	16	5	0	0
34	Cresbard	16	5	0	0
35	Tabor	14	4	0	47,898
36	Miller	13	4	0	33,063
37	Brookings	9	4	0	22,980
38	Mitchell	14	4	0	15,651
39	Yankton	15	4	0	15,411
40	Huron	14	4	0	14,263
41	Vermillion	13	4	0	11,254
42	Harrisburg	8	4	0	9,700
43	Tea	6	4	0	6,847
44	Winner	6	4	0	6,189
45	Lennox	6	4	0	2,571
46	Flandreau	13	4	0	2,372
47	Parkston	14	4	0	1,508
48	Aurora	9	4	0	922
49	Onida	13	4	0	634
50	Colman	13	4	0	593
51	Burke	6	4	0	575
52	Valentine	10	4	0	533
53	Wolsey	13	4	0	459
54	Irene	14	4	0	420
55	Egan	13	4	0	363
56	Trent	13	4	0	232
57	Wessington	13	4	0	175
58	Dallas	6	4	0	132
59	Tolstoy	13	4	0	34
60	Volin	14	4	0	0
61	Centerville	6	4	0	0
62	Beresford	6	4	0	0
63	Avon	14	4	0	0
64	Bonesteel	6	4	0	0
65	Highmore	13	4	0	0
66	Gettysburg	13	4	0	0
67	Hoven	13	4	0	0
68	Menno	14	4	0	0
69	Lesterville	14	4	0	0
70	Mission Hill	14	4	0	0
71	Tyndall	14	4	0	0
72	Freeman	14	4	0	0
73	Valley Springs	4	4	0	0
74	Utica	14	4	0	0
75	Dell Rapids	8	3	0	28,893
76	Lake Andes	6	3	0	20,340
77	Spearfish	6	3	0	12,193
78	Box Elder	5	3	0	10,551
79	Toronto	8	3	0	8,500
80	Arlington	8	3	0	6,365
81	Clark	4	3	0	4,037
82	Chamberlain	3	3	0	2,473
83	Sisseton	5	3	0	2,470
84	Wagner	6	3	0	1,600
85	Clear Lake	8	3	0	1,264
86	Platte	6	3	0	1,256
87	Gregory	6	3	0	1,221
88	Oral	5	3	0	1,057
89	Hill City	3	3	0	1,032
90	Piedmont	5	3	0	891
91	Howard	5	3	0	858
92	Elkton	8	3	0	724
93	Plankinton	7	3	0	712
94	Armour	6	3	0	702
95	Castlewood	3	3	0	698
96	Kimball	7	3	0	572
97	Humboldt	8	3	0	567
98	Corsica	6	3	0	561
99	Lake Preston	5	3	0	553
100	White	8	3	0	537
101	Wilmot	6	3	0	499
102	Montrose	6	3	0	483
103	Big Stone City	6	3	0	412
104	White Lake	7	3	0	359
105	Florence	6	3	0	352
106	Keystone	5	3	0	349
107	Stickney	7	3	0	300
108	Henry	4	3	0	286
109	Chancellor	7	3	0	266
110	Willow Lake	4	3	0	260
111	Iroquois	5	3	0	260
112	Gary	8	3	0	240
113	Pickstown	6	3	0	201
114	Delmont	6	3	0	153
115	Wallace	4	3	0	89
116	Raymond	4	3	0	53
117	Crooks	8	3	0	0
118	Baltic	8	3	0	0
119	Fairburn	5	3	0	0
120	Oelrichs	5	3	0	0
121	Hartford	8	3	0	0
122	Garretson	8	3	0	0
123	Colton	8	3	0	0
124	Brandon	2	2	0	10,226
125	Britton	6	2	0	8,648
126	Parker	4	2	0	7,000
127	Madison	3	2	0	6,071
128	Belle Fourche	5	2	0	5,874
129	Black Hawk	4	2	0	5,670
130	Eagle Butte	2	2	0	4,000
131	Dakota Dunes	5	2	0	3,350
132	North Sioux City	2	2	0	3,042
133	Elk Point	4	2	0	2,124
134	Fort Pierre	4	2	0	2,115
135	Custer	3	2	0	1,919
136	Volga	2	2	0	1,768
137	Salem	5	2	0	1,325
138	Deadwood	3	2	0	1,270
139	Wessington Springs	5	2	0	895
140	Viborg	4	2	0	782
141	Marion	4	2	0	774
142	Philip	3	2	0	759
143	Alexandria	2	2	0	649
144	Canistota	4	2	0	632
145	Woonsocket	4	2	0	618
146	Newell	2	2	0	615
147	Tripp	6	2	0	575
148	Mclaughlin	2	2	0	569
149	Lake Norden	2	2	0	554
150	Kadoka	4	2	0	543
151	Veblen	6	2	0	539
152	Dupree	2	2	0	494
153	Bridgewater	2	2	0	492
154	Hot Springs	4	2	0	492
155	Murdo	4	2	0	488
156	Jefferson	2	2	0	475
157	Waubay	5	2	0	473
158	Presho	4	2	0	472
159	Mount Vernon	2	2	0	461
160	Bryant	7	2	0	460
161	Emery	2	2	0	447
162	Hermosa	2	2	0	443
163	Rosholt	6	2	0	427
164	Hurley	4	2	0	415
165	Hayti	7	2	0	389
166	Oacoma	2	2	0	386
167	Faith	2	2	0	367
168	Buffalo	2	2	0	330
169	Ethan	2	2	0	320
170	Langford	6	2	0	313
171	Colome	2	2	0	296
172	Kennebec	4	2	0	265
173	New Effington	6	2	0	247
174	Hecla	6	2	0	208
175	Nisland	2	2	0	206
176	Summerset	4	2	0	200
177	Spencer	2	2	0	170
178	Letcher	2	2	0	159
179	Scotland	6	2	0	150
180	Pierpont	6	2	0	129
181	Midland	2	2	0	120
182	Badger	3	2	0	105
183	Wasta	5	2	0	84
184	Fruitdale	2	2	0	74
185	Edgemont	4	2	1	42
186	Canton	2	2	0	0
187	Lemmon	2	2	0	0
188	Isabel	2	2	0	0
189	Springfield	7	2	0	0
190	Buffalo Gap	2	2	0	0
191	Wakonda	3	1	0	5,800
192	Milbank	1	1	0	3,037
193	Lead	2	1	0	2,887
194	De Smet	1	1	0	1,056
195	Worthing	5	1	0	1,043
196	Whitewood	2	1	0	999
197	Alcester	5	1	0	820
198	Estelline	4	1	0	752
199	Wall	4	1	0	699
200	New Underwood	1	1	0	679
201	Gayville	3	1	0	392
202	Westport	5	1	0	130
203	Faulkton	5	1	0	120
204	Vale	3	1	0	120
205	Mcintosh	1	1	0	111
206	Canova	1	1	0	99
207	Corona	5	1	0	82
208	Ward	5	1	0	54
209	Garden City	4	1	0	50
210	Morristown	1	1	0	47
211	Martin	1	1	0	0
212	Sturgis	1	0	0	7,020
213	Fort Meade	0	0	0	800
214	Timber Lake	3	0	0	499
215	Summit	0	0	0	283
216	Artesian	4	0	0	198
217	South Shore	0	0	0	180
218	Mobridge	2	0	0	166
219	Carpenter	0	0	0	133
220	Frankfort	0	0	0	95
221	Stratford	0	0	0	90

Recommended Filtration for South Dakota

Based on the most common contaminants found across South Dakota (Total trihalomethanes (TTHMs), Haloacetic acids (HAA5), Barium*), we recommend a reverse osmosis system or high-quality carbon block filter to remove disinfection byproducts and their precursors.

Echo RO System

Removes up to 99.9% of contaminants. The gold standard for drinking water in South Dakota homes.

View RO Systems

Echo Whole-Home Filter

Protect every tap in your home from chlorine, VOCs, and disinfection byproducts.

View Whole-Home Filters

Echo Hydrogen Water Flask

Once your water is clean, supercharge it with molecular hydrogen for antioxidant and anti-inflammatory benefits.

Shop Hydrogen Flask

Frequently Asked Questions

Is South Dakota tap water safe to drink?

Water quality varies significantly across South Dakota. Of the 221 cities analyzed, the average city has 2.9 contaminants above EWG health guidelines. The best water quality was found in Sturgis. We recommend checking your specific city's report for detailed information.

What city has the best water in South Dakota?

Based on our analysis, Sturgis has the fewest contaminants above EWG health guidelines in South Dakota, with 0 above guideline levels.

What city has the worst water in South Dakota?

Based on our analysis, Hudson has the most contaminants above EWG health guidelines in South Dakota, with 13 above guideline levels.

What's the best water filter for South Dakota residents?

For most South Dakota households, we recommend a reverse osmosis (RO) system for drinking water and a whole-home filter for showers and baths. The specific recommendation depends on your city's contaminant profile — check your city's report for personalized guidance.

National Water Quality Reports

Data sources: Environmental Working Group (EWG) Tap Water Database, U.S. EPA Safe Drinking Water Information System (SDWIS)

Last updated: September 2026

Methodology: Contaminant levels are compared against both EPA legal limits (Maximum Contaminant Levels) and EWG health guidelines, which are often stricter and based on the latest scientific research.

South Dakota Water Quality Report (2026)