Chromium-6 Contamination

Chromium-6 in Missouri Drinking Water

Ranked by max chromium-6 detected (µg/L) · UCMR 3 data (2013–2015) · Data from EPA SDWIS & UCMR

Cities Tested

Detected

100%

% Detected

1.14 µg/L

State Avg

▼ 0% vs national

vs National

426

Health Violations

Analysis

Chromium-6 in Missouri: what the data shows

Missouri has 77 cities with chromium-6 data from the EPA's UCMR 3 program (2013–2015). Hexavalent chromium (Cr VI) was detected in 77 of those cities. There is currently no federal MCL for chromium-6 — California's 10 µg/L limit is used as a reference. The state average max detected level is 1.14 µg/L. Chromium-6 occurs naturally in some groundwater aquifers but also from industrial discharge, particularly from steel processing, chrome plating, and leather tanning. It is distinct from trivalent chromium (Cr III), which is an essential nutrient at low doses. The National Toxicology Program and IARC classify chromium-6 as a carcinogen via inhalation; the evidence for drinking water carcinogenicity is strong but regulatory action at the federal level remains pending as of 2026. Reverse osmosis systems effectively remove chromium-6 to near-undetectable levels.

Comparison

Cities exceeding No federal MCL (CA: 10 µg/L)

Missouri

100%

77 of 77 cities

← = Exactly at national rate

National avg

100%

4005 of 4005 cities

City Map

Chromium-6 data across Missouri

Each dot is a city with UCMR 3 chromium-6 data. Detected cities are shown; there is no federal MCL — California's 10 µg/L limit is used as a reference. Size reflects population served.

Worst Offenders

Top 10 cities by chromium-6 level in Missouri

Highest Chromium-6 levels (µg/L)

All Cities

All Missouri cities ranked by chromium-6 level

#	City	Level	Detected?	Violations	Grade
1	Belton	6.20 µg/L	Detected	5	B-
2	Blue Springs	4.00 µg/L	Detected	0	B+
3	Grandview	3.10 µg/L	Detected	0	A-
4	Liberty	3.00 µg/L	Detected	8	C+
5	Raytown	3.00 µg/L	Detected	2	B+
6	Raymoor	2.90 µg/L	Detected	4	A
7	Kearney	2.90 µg/L	Detected	3	B+
8	Kansas City	2.80 µg/L	Detected	1	B
9	Lees Summit	2.70 µg/L	Detected	1	B+
10	O Fallon	2.40 µg/L	Detected	10	F
11	High Ridge	2.30 µg/L	Detected	15	B-
12	High Ridge	2.30 µg/L	Detected	1	A
13	High Ridge	2.30 µg/L	Detected	1	A
14	St. Peters	2.20 µg/L	Detected	0	B+
15	Macon	2.20 µg/L	Detected	11	A-
16	Wentzville	2.18 µg/L	Detected	9	A-
17	Parkville	2.11 µg/L	Detected	0	B+
18	Jefferson City	2.00 µg/L	Detected	19	B+
19	Arnold	2.00 µg/L	Detected	0	B
20	Grain Valley	1.90 µg/L	Detected	1	A
21	Marshall	1.90 µg/L	Detected	33	B-
22	Excelsior Spgs.	1.80 µg/L	Detected	3	B+
23	Barnhart	1.70 µg/L	Detected	1	A-
24	Neosho	1.60 µg/L	Detected	21	C-
25	Chesterfield	1.55 µg/L	Detected	11	B-
26	St. Louis	1.50 µg/L	Detected	28	F
27	St. Charles	1.40 µg/L	Detected	0	B+
28	Kirkwood	1.40 µg/L	Detected	0	A+
29	Kennett	1.40 µg/L	Detected	1	B
30	Columbia	1.30 µg/L	Detected	52	C
31	Higginsville	1.22 µg/L	Detected	17	B+
32	Mexico	1.09 µg/L	Detected	0	A-
33	Independence	1.00 µg/L	Detected	0	B
34	Cape Girardeau	1.00 µg/L	Detected	127	D
35	Gladstone	0.99 µg/L	Detected	0	B+
36	St. Joseph	0.94 µg/L	Detected	1	A-
37	St. Joseph	0.94 µg/L	Detected	0	A-
38	St. Joseph	0.94 µg/L	Detected	0	A-
39	St. Joseph	0.94 µg/L	Detected	0	A-
40	St. Joseph	0.94 µg/L	Detected	0	A-
41	Saline	0.94 µg/L	Detected	17	B+
42	Farmington	0.68 µg/L	Detected	251	D
43	Hannibal	0.58 µg/L	Detected	34	C+
44	Beverly Hills	0.49 µg/L	Detected	4	B-
45	Beverly Hills	0.49 µg/L	Detected	3	B+
46	Moberly	0.42 µg/L	Detected	14	A-
47	Willow Springs	0.41 µg/L	Detected	1	B+
48	Lebanon	0.39 µg/L	Detected	16	B
49	West Plains	0.33 µg/L	Detected	15	B+
50	Summersville	0.30 µg/L	Detected	6	B-
51	Des Peres	0.26 µg/L	Detected	2149	F
52	Garden City	0.26 µg/L	Detected	77	B-
53	Beufort	0.26 µg/L	Detected	4	A
54	Aurora	0.25 µg/L	Detected	90	D
55	Joplin	0.25 µg/L	Detected	53	F
56	Springfield	0.18 µg/L	Detected	59	F
57	Kirksville	0.14 µg/L	Detected	15	A-
58	Holden	0.14 µg/L	Detected	8	A
59	Pacific	0.13 µg/L	Detected	47	D
60	Fort Leonard Wood	0.13 µg/L	Detected	0	A+
61	Poplar Bluff	0.13 µg/L	Detected	47	C
62	Dexter	0.09 µg/L	Detected	3	A-
63	Republic	0.08 µg/L	Detected	5	A-
64	Washington	0.08 µg/L	Detected	31	C+
65	Ozark	0.08 µg/L	Detected	65	F
66	Battlefield	0.07 µg/L	Detected	11	A-
67	Carthage	0.07 µg/L	Detected	21	D+
68	Jackson	0.07 µg/L	Detected	72	C+
69	Hallsville	0.07 µg/L	Detected	2	A
70	Smithville	0.06 µg/L	Detected	16	A
71	Rolla	0.05 µg/L	Detected	32	D
72	Sedalia	0.05 µg/L	Detected	60	F
73	Brookfield	0.04 µg/L	Detected	20	A-
74	Warrensburg	0.04 µg/L	Detected	0	B+
75	Sikeston	0.04 µg/L	Detected	5	B
76	Fulton	0.03 µg/L	Detected	13	B+
77	Branson	0.03 µg/L	Detected	70	D

FAQ

Frequently asked questions about chromium-6 in Missouri

Is chromium-6 in Missouri tap water dangerous?

Chromium-6 (hexavalent chromium) is a potential human carcinogen. There is currently no federal MCL — California's 10 µg/L limit is the most protective US standard. 77 cities in Missouri had detectable chromium-6 in UCMR 3 testing (2013–2015). Reverse osmosis is the most effective removal method.

Where does chromium-6 come from in Missouri water?

Chromium-6 enters water supplies from two main sources: natural weathering of chromium-containing rock formations (especially in the Southwest and parts of the Midwest) and industrial discharge from steel mills, chrome plating, and coal ash sites. Groundwater systems are more commonly affected by natural sources, while surface water systems near industrial areas face pollution-related risks.

How can I filter chromium-6 from my water in Missouri?

Reverse osmosis (RO) systems are the most effective, removing over 95% of chromium-6. Some high-quality activated alumina or anion exchange filters also provide significant reduction. Standard carbon filters and pitcher filters are generally NOT effective against chromium-6. Look for filters certified by NSF International against NSF/ANSI 58 (for RO systems).

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