South Dakota Tap Water Quality Report

221 cities analyzed • 778,464 people served

Updated March 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	184 of 221	83%
Haloacetic acids (HAA5) carcinogen	163 of 221	74%
Barium*	106 of 221	48%
Lithium*	81 of 221	37%
Fluoride*	80 of 221	36%
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	Doland	16	5	0	0
24	Bowdle	16	5	0	0
25	Java	16	5	0	0
26	Redfield	16	5	0	0
27	Seneca	16	5	0	0
28	Cresbard	16	5	0	0
29	Northville	16	5	0	0
30	Brentford	16	5	0	0
31	Hosmer	16	5	0	0
32	Selby	16	5	0	0
33	Pollock	16	5	0	0
34	Roscoe	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	Valley Springs	4	4	0	0
61	Gettysburg	13	4	0	0
62	Menno	14	4	0	0
63	Lesterville	14	4	0	0
64	Avon	14	4	0	0
65	Highmore	13	4	0	0
66	Hoven	13	4	0	0
67	Bonesteel	6	4	0	0
68	Centerville	6	4	0	0
69	Tyndall	14	4	0	0
70	Freeman	14	4	0	0
71	Mission Hill	14	4	0	0
72	Volin	14	4	0	0
73	Utica	14	4	0	0
74	Dell Rapids	8	3	0	28,893
75	Lake Andes	6	3	0	20,340
76	Spearfish	6	3	0	12,193
77	Box Elder	5	3	0	10,551
78	Toronto	8	3	0	8,500
79	Arlington	8	3	0	6,365
80	Clark	4	3	0	4,037
81	Chamberlain	3	3	0	2,473
82	Sisseton	5	3	0	2,470
83	Wagner	6	3	0	1,600
84	Clear Lake	8	3	0	1,264
85	Platte	6	3	0	1,256
86	Gregory	6	3	0	1,221
87	Oral	5	3	0	1,057
88	Hill City	3	3	0	1,032
89	Piedmont	5	3	0	891
90	Howard	5	3	0	858
91	Elkton	8	3	0	724
92	Plankinton	7	3	0	712
93	Armour	6	3	0	702
94	Castlewood	3	3	0	698
95	Kimball	7	3	0	572
96	Humboldt	8	3	0	567
97	Corsica	6	3	0	561
98	Lake Preston	5	3	0	553
99	White	8	3	0	537
100	Wilmot	6	3	0	499
101	Montrose	6	3	0	483
102	Big Stone City	6	3	0	412
103	White Lake	7	3	0	359
104	Florence	6	3	0	352
105	Keystone	5	3	0	349
106	Stickney	7	3	0	300
107	Henry	4	3	0	286
108	Chancellor	7	3	0	266
109	Willow Lake	4	3	0	260
110	Iroquois	5	3	0	260
111	Gary	8	3	0	240
112	Pickstown	6	3	0	201
113	Delmont	6	3	0	153
114	Wallace	4	3	0	89
115	Raymond	4	3	0	53
116	Garretson	8	3	0	0
117	Baltic	8	3	0	0
118	Fairburn	5	3	0	0
119	Oelrichs	5	3	0	0
120	Crooks	8	3	0	0
121	Hartford	8	3	0	0
122	Colton	8	3	0	0
123	Brandon	2	2	0	10,226
124	Britton	6	2	0	8,648
125	Parker	4	2	0	7,000
126	Madison	3	2	0	6,071
127	Belle Fourche	5	2	0	5,874
128	Black Hawk	4	2	0	5,670
129	Eagle Butte	2	2	0	4,000
130	Dakota Dunes	5	2	0	3,350
131	North Sioux City	2	2	0	3,042
132	Elk Point	4	2	0	2,124
133	Fort Pierre	4	2	0	2,115
134	Custer	3	2	0	1,919
135	Volga	2	2	0	1,768
136	Salem	5	2	0	1,325
137	Deadwood	3	2	0	1,270
138	Wessington Springs	5	2	0	895
139	Viborg	4	2	0	782
140	Marion	4	2	0	774
141	Philip	3	2	0	759
142	Alexandria	2	2	0	649
143	Canistota	4	2	0	632
144	Woonsocket	4	2	0	618
145	Newell	2	2	0	615
146	Tripp	6	2	0	575
147	Mclaughlin	2	2	0	569
148	Lake Norden	2	2	0	554
149	Kadoka	4	2	0	543
150	Veblen	6	2	0	539
151	Dupree	2	2	0	494
152	Bridgewater	2	2	0	492
153	Hot Springs	4	2	0	492
154	Murdo	4	2	0	488
155	Jefferson	2	2	0	475
156	Waubay	5	2	0	473
157	Presho	4	2	0	472
158	Mount Vernon	2	2	0	461
159	Bryant	7	2	0	460
160	Emery	2	2	0	447
161	Hermosa	2	2	0	443
162	Rosholt	6	2	0	427
163	Hurley	4	2	0	415
164	Hayti	7	2	0	389
165	Oacoma	2	2	0	386
166	Faith	2	2	0	367
167	Buffalo	2	2	0	330
168	Ethan	2	2	0	320
169	Langford	6	2	0	313
170	Colome	2	2	0	296
171	Kennebec	4	2	0	265
172	New Effington	6	2	0	247
173	Hecla	6	2	0	208
174	Nisland	2	2	0	206
175	Summerset	4	2	0	200
176	Spencer	2	2	0	170
177	Letcher	2	2	0	159
178	Scotland	6	2	0	150
179	Pierpont	6	2	0	129
180	Midland	2	2	0	120
181	Badger	3	2	0	105
182	Wasta	5	2	0	84
183	Fruitdale	2	2	0	74
184	Edgemont	4	2	1	42
185	Springfield	7	2	0	0
186	Canton	2	2	0	0
187	Isabel	2	2	0	0
188	Buffalo Gap	2	2	0	0
189	Lemmon	2	2	0	0
190	Wakonda	3	1	0	5,800
191	Milbank	1	1	0	3,037
192	Lead	2	1	0	2,887
193	De Smet	1	1	0	1,056
194	Worthing	5	1	0	1,043
195	Whitewood	2	1	0	999
196	Alcester	5	1	0	820
197	Estelline	4	1	0	752
198	Wall	4	1	0	699
199	New Underwood	1	1	0	679
200	Gayville	3	1	0	392
201	Westport	5	1	0	130
202	Vale	3	1	0	120
203	Mcintosh	1	1	0	111
204	Canova	1	1	0	99
205	Corona	5	1	0	82
206	Ward	5	1	0	54
207	Garden City	4	1	0	50
208	Morristown	1	1	0	47
209	Beresford	5	1	0	0
210	Martin	1	1	0	0
211	Sturgis	1	0	0	7,020
212	Fort Meade	0	0	0	800
213	Timber Lake	3	0	0	499
214	Summit	0	0	0	283
215	Artesian	4	0	0	198
216	South Shore	0	0	0	180
217	Mobridge	2	0	0	166
218	Carpenter	0	0	0	133
219	Faulkton	0	0	0	120
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: March 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)