Lithium Contamination

Lithium in Illinois Drinking Water

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

107

Cities Tested

107

Detected

100%

% Detected

36.0 µg/L

State Avg

▼ 0% vs national

vs National

695

Health Violations

Analysis

Lithium in Illinois: what the data shows

Illinois has 107 cities with lithium data from the EPA's UCMR 5 program (2023–2025). Lithium was detected in 107 of those cities. There is currently no federal MCL or health advisory for lithium — the state average max detected level is 36.0 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

Illinois

100%

107 of 107 cities

← = Exactly at national rate

National avg

100%

2808 of 2808 cities

City Map

Lithium data across Illinois

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 Illinois

Highest Lithium levels (µg/L)

All Cities

All Illinois cities ranked by lithium level

#	City	Level	Detected?	Violations	Grade
1	Monmouth	230.0 µg/L	Detected	29	A-
2	Coal City	150.0 µg/L	Detected	40	D
3	Milan	130.0 µg/L	Detected	28	D
4	Oswego	114.0 µg/L	Detected	24	A-
5	Oglesby	110.0 µg/L	Detected	6	B-
6	Gardner	100.0 µg/L	Detected	24	B+
7	Manhattan	99.0 µg/L	Detected	21	C+
8	Richton Park	90.0 µg/L	Detected	5	F
9	Braidwood	86.0 µg/L	Detected	14	A-
10	Valmeyer	81.0 µg/L	Detected	1	C-
11	Beecher	78.0 µg/L	Detected	0	A-
12	Peru	75.7 µg/L	Detected	92	F
13	Sauk	70.3 µg/L	Detected	5	D
14	Channahon	69.0 µg/L	Detected	45	B
15	Western Springs	66.7 µg/L	Detected	2	B
16	Lockport	65.0 µg/L	Detected	20	F
17	Frankfort	62.6 µg/L	Detected	7	B+
18	Joliet	54.7 µg/L	Detected	131	F
19	Romeoville	54.6 µg/L	Detected	17	A-
20	Eldorado	54.0 µg/L	Detected	3	B-
21	Lemont	53.8 µg/L	Detected	26	D
22	Yorkville	49.5 µg/L	Detected	83	C+
23	Minooka	47.9 µg/L	Detected	6	A-
24	Peotone	46.0 µg/L	Detected	3	A-
25	Coal Valley	46.0 µg/L	Detected	12	F
26	Macomb	45.5 µg/L	Detected	39	D
27	Bushnell	44.0 µg/L	Detected	6	A
28	Zion	43.3 µg/L	Detected	1	B
29	St. Charles	42.0 µg/L	Detected	17	F
30	Marseilles	42.0 µg/L	Detected	116	D
31	Monee	42.0 µg/L	Detected	2	B
32	Warrenville	39.9 µg/L	Detected	0	B+
33	Steger	39.0 µg/L	Detected	8	B+
34	West Chicago	36.8 µg/L	Detected	22	A
35	Hardin	36.0 µg/L	Detected	4	A-
36	Crest Hill	34.8 µg/L	Detected	12	F
37	North Aurora	34.6 µg/L	Detected	27	A-
38	Batavia	34.5 µg/L	Detected	33	B+
39	Crete	34.0 µg/L	Detected	4	B
40	Coleta	33.4 µg/L	Detected	1	A-
41	Montgomery	32.7 µg/L	Detected	4	A-
42	Chicago	32.0 µg/L	Detected	68	F
43	Libertyville	31.0 µg/L	Detected	14	C
44	Kewanee	30.3 µg/L	Detected	34	B
45	Saint Charles	28.6 µg/L	Detected	3	B+
46	Morris	28.5 µg/L	Detected	74	F
47	Columbia	28.2 µg/L	Detected	0	B+
48	Shorewood	27.9 µg/L	Detected	4	A-
49	Geneva	27.0 µg/L	Detected	67	B-
50	Mendota	27.0 µg/L	Detected	25	B
51	Spring Valley	27.0 µg/L	Detected	15	A
52	Lake Zurich	26.0 µg/L	Detected	35	B+
53	Itasca	26.0 µg/L	Detected	2	A
54	Caseyville	25.5 µg/L	Detected	3	B+
55	Dupo	24.0 µg/L	Detected	0	B
56	Ashkum	24.0 µg/L	Detected	11	C+
57	Silvis	23.0 µg/L	Detected	14	F
58	Cahokia	21.8 µg/L	Detected	0	A+
59	Park Forest	21.5 µg/L	Detected	2	A
60	Peoria	20.8 µg/L	Detected	5	D+
61	Sycamore	20.3 µg/L	Detected	31	A-
62	Quincy	20.0 µg/L	Detected	3	B-
63	La Salle	20.0 µg/L	Detected	6	B-
64	Waterloo	19.5 µg/L	Detected	1	C
65	Elgin	19.3 µg/L	Detected	9	C-
66	South Elgin	19.1 µg/L	Detected	28	C
67	De Kalb	18.9 µg/L	Detected	7	B+
68	Aurora	18.6 µg/L	Detected	20	D
69	Sugar Grove	18.4 µg/L	Detected	7	A-
70	Chester	18.0 µg/L	Detected	7	A
71	Elburn	18.0 µg/L	Detected	63	D
72	East Alton	18.0 µg/L	Detected	0	B
73	Fulton	18.0 µg/L	Detected	6	B
74	Pekin	17.2 µg/L	Detected	1	D+
75	Wasco	17.0 µg/L	Detected	14	A
76	Anna	16.0 µg/L	Detected	7	B-
77	Streator	14.5 µg/L	Detected	14	A-
78	Champaign	14.1 µg/L	Detected	0	A
79	Morrison	14.0 µg/L	Detected	3	B+
80	Jerseyville	13.9 µg/L	Detected	6	A-
81	Granite City	13.4 µg/L	Detected	0	B+
82	Antioch	13.4 µg/L	Detected	6	C-
83	Pontiac	13.3 µg/L	Detected	10	C
84	East St Louis	13.1 µg/L	Detected	1	B+
85	Ottawa	13.1 µg/L	Detected	62	F
86	Cortland	13.0 µg/L	Detected	25	A
87	Andalusia	13.0 µg/L	Detected	0	B+
88	Barrington	12.0 µg/L	Detected	3	B+
89	Island Lake	12.0 µg/L	Detected	1	A-
90	Creve Coeur	12.0 µg/L	Detected	4	A-
91	O Fallon	11.6 µg/L	Detected	17	A-
92	Mchenry	11.0 µg/L	Detected	57	F
93	Gibson City	11.0 µg/L	Detected	0	A
94	Troy	10.9 µg/L	Detected	3	A-
95	Lake In The Hills	10.8 µg/L	Detected	4	A-
96	Carpentersville	10.7 µg/L	Detected	0	B+
97	Fox Lake	10.6 µg/L	Detected	5	C+
98	Hoopeston	10.0 µg/L	Detected	2	A-
99	Alton	9.6 µg/L	Detected	1	B
100	Pocahontas	9.6 µg/L	Detected	1	C+
101	Hainesville	9.6 µg/L	Detected	3	B+
102	Morton	9.5 µg/L	Detected	13	B-
103	Glen Carbon	9.4 µg/L	Detected	0	B
104	Red Bud	9.4 µg/L	Detected	3	B-
105	Machesney Park	9.3 µg/L	Detected	4	B
106	Scott Air Force Base	9.2 µg/L	Detected	3	A
107	Millstadt	9.2 µg/L	Detected	4	A-

FAQ

Frequently asked questions about lithium in Illinois

Is lithium in Illinois tap water harmful?

Lithium has no federal MCL or health advisory. Some state agencies use 60 µg/L as a screening level. 107 cities in Illinois 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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