Lithium Contamination

Lithium in South Dakota Drinking Water

Ranked by max lithium detected (µg/L) · UCMR 5 data (2023–2025) · Data from EPA SDWIS & UCMR

Cities Tested

Detected

100%

% Detected

77.5 µg/L

State Avg

▼ 0% vs national

vs National

117

Health Violations

Analysis

Lithium in South Dakota: what the data shows

South Dakota has 42 cities with lithium data from the EPA's UCMR 5 program (2023–2025). Lithium was detected in 42 of those cities. There is currently no federal MCL or health advisory for lithium — the state average max detected level is 77.5 µg/L. Nationally, lithium is detected in roughly 28% of sampled water systems. Lithium occurs naturally in groundwater, particularly in arid western states, and is concentrated in some surface waters near industrial discharge or geothermal sources. UCMR 5 added lithium monitoring in 2023, providing the first systematic national snapshot of public-water lithium levels. At therapeutic doses (administered as a medication), lithium is used to treat bipolar disorder. Chronic low-dose exposure from drinking water has been associated in some studies with effects on thyroid function and possibly mood. The most protective state guidance value is around 60 µg/L. Reverse osmosis and ion exchange are effective removal methods.

Comparison

Cities exceeding No federal MCL or HA

South Dakota

100%

42 of 42 cities

← = Exactly at national rate

National avg

100%

2808 of 2808 cities

City Map

Lithium data across South Dakota

Each dot is a city with UCMR 5 lithium testing data. Detected cities are shown — there is no federal limit, though some states use 60 µg/L as a screening level. Size reflects population served.

Worst Offenders

Top 10 cities by lithium level in South Dakota

Highest Lithium levels (µg/L)

All Cities

All South Dakota cities ranked by lithium level

#	City	Level	Detected?	Violations	Grade
1	Vermillion	440.0 µg/L	Detected	0	A
2	Wall	238.0 µg/L	Detected	7	A-
3	Huron	140.0 µg/L	Detected	9	C
4	Britton	137.0 µg/L	Detected	37	C
5	Hot Springs	122.0 µg/L	Detected	22	B-
6	Beresford	105.0 µg/L	Detected	19	B
7	Beresford	105.0 µg/L	Detected	7	B+
8	Aberdeen	100.0 µg/L	Detected	197	F
9	Sioux Falls	95.0 µg/L	Detected	30	C-
10	Parker	95.0 µg/L	Detected	3	A-
11	Madison	87.0 µg/L	Detected	9	A+
12	Murdo	80.0 µg/L	Detected	2	A-
13	Pierre	74.1 µg/L	Detected	8	A-
14	Pine Ridge	71.0 µg/L	Detected	138	F
15	Rosebud	69.6 µg/L	Detected	18	F
16	Yankton	69.0 µg/L	Detected	29	B-
17	Mission	69.0 µg/L	Detected	2	B+
18	Mobridge	67.5 µg/L	Detected	3	B+
19	Eagle Butte	64.8 µg/L	Detected	18	B-
20	Eagle Butte	64.8 µg/L	Detected	15	A-
21	Philip	64.6 µg/L	Detected	24	A
22	Mitchell	64.0 µg/L	Detected	6	A-
23	Lake Andes	61.5 µg/L	Detected	12	B
24	Miller	60.0 µg/L	Detected	34	C+
25	Tea	55.9 µg/L	Detected	1	A
26	Milbank	55.7 µg/L	Detected	0	B+
27	Harrisburg	55.0 µg/L	Detected	0	A
28	Wakonda	52.5 µg/L	Detected	4	B+
29	Watertown	52.2 µg/L	Detected	2	A
30	Watertown	52.2 µg/L	Detected	1	A
31	Tabor	52.0 µg/L	Detected	3	A-
32	Tabor	52.0 µg/L	Detected	4	A-
33	Brandon	44.8 µg/L	Detected	0	A-
34	Dell Rapids	41.4 µg/L	Detected	2	A
35	Brookings	37.4 µg/L	Detected	11	D
36	Egan	36.1 µg/L	Detected	11	B+
37	Toronto	26.6 µg/L	Detected	0	B+
38	Toronto	26.6 µg/L	Detected	0	A-
39	Arlington	25.2 µg/L	Detected	5	C
40	Rapid City	23.4 µg/L	Detected	349	F
41	Box Elder	14.0 µg/L	Detected	17	B-
42	Ellsworth Afb	10.0 µg/L	Detected	4	A

FAQ

Frequently asked questions about lithium in South Dakota

Is lithium in South Dakota tap water harmful?

Lithium has no federal MCL or health advisory. Some state agencies use 60 µg/L as a screening level. 42 cities in South Dakota had detectable lithium in UCMR 5 testing. Therapeutic lithium doses (used to treat bipolar disorder) are far higher than typical drinking-water levels, but chronic low-level exposure has been studied for potential thyroid and mood effects.

Where does lithium in tap water come from?

Lithium occurs naturally in groundwater, especially in arid western states with lithium-bearing geology (parts of Nevada, California, North Carolina, Texas). It can also enter water from industrial sources such as battery manufacturing, ceramics, and lithium-mining wastewater. Geothermal hot springs are another natural source.

How can I remove lithium from my drinking water?

Reverse osmosis is highly effective at removing lithium, typically reducing it by 90% or more. Ion exchange systems and distillation also work well. Standard activated carbon filters are NOT effective against lithium. If you rely on a private well in a lithium-rich geological area, consider testing.

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