Manganese Contamination

Manganese in Indiana Drinking Water

Ranked by max manganese detected (µg/L) · UCMR 4 data (2018–2020) · Data from EPA SDWIS & UCMR

Cities Tested

Over SMCL

19%

% Over SMCL

44.3 µg/L

State Avg

▲ 1% vs national

vs National

305

Health Violations

Analysis

Manganese in Indiana: what the data shows

Indiana has 73 cities with manganese data from the EPA's UCMR 4 program (2018–2020). Manganese exceeded the 50 µg/L EPA secondary MCL in 14 of those cities. The state average max detected level is 44.3 µg/L. Manganese occurs naturally in groundwater and surface water. Elevated levels are common in areas with iron-rich geology and in systems that draw from reservoirs with low dissolved oxygen. The secondary MCL of 50 µg/L is based on aesthetic concerns (taste, staining), but health-based guidelines suggest neurological effects at higher concentrations. Emerging research links chronic manganese exposure in drinking water to neurodevelopmental effects in children, including reduced IQ and behavioral issues. Oxidation filtration and water softeners are effective at removing manganese from household water.

Comparison

Cities exceeding 50 µg/L EPA Secondary MCL

Indiana

19%

14 of 73 cities

→ ▲ 1% above national rate (worse)

National avg

18%

729 of 4068 cities

City Map

Manganese data across Indiana

Each dot is a city with UCMR 4 manganese testing data. Cities where manganese exceeds the 50 µg/L EPA secondary MCL are highlighted. Size reflects population served.

Worst Offenders

Top 10 cities by manganese level in Indiana

Highest Manganese levels (µg/L)

All Cities

All Indiana cities ranked by manganese level

#	City	Level	Over SMCL?	Violations	Grade
1	Kokomo	860.0 µg/L	Over SMCL	24	F
2	West Lafayette	370.0 µg/L	Over SMCL	2	A-
3	Vincennes	360.9 µg/L	Over SMCL	0	A-
4	Lafayette	290.0 µg/L	Over SMCL	24	F
5	Goshen	183.5 µg/L	Over SMCL	24	D
6	South Bend	162.0 µg/L	Over SMCL	7	F
7	Taylorsville	144.0 µg/L	Over SMCL	1	A-
8	Mishawaka	113.0 µg/L	Over SMCL	8	C+
9	Greenwood	82.0 µg/L	Over SMCL	0	A
10	Bloomfield	81.7 µg/L	Over SMCL	1	B+
11	Plymouth	70.1 µg/L	Over SMCL	16	D
12	Borden	69.8 µg/L	Over SMCL	23	B+
13	Ramsey	54.1 µg/L	Over SMCL	2	A
14	Martinsville	51.6 µg/L	Over SMCL	12	F
15	Greenfield	38.8 µg/L	No	3	B-
16	Plainfield	32.8 µg/L	No	9	B-
17	Lawrence	32.4 µg/L	No	4	B
18	Brownsburg	24.0 µg/L	No	0	A-
19	Hammond	18.7 µg/L	No	1	A-
20	Laporte	17.2 µg/L	No	3	D+
21	Lebanon	15.2 µg/L	No	7	B+
22	Wabash	15.0 µg/L	No	30	F
23	Decatur	10.0 µg/L	No	8	C-
24	Elkhart	9.9 µg/L	No	9	B
25	Warren	9.7 µg/L	No	4	B+
26	St. John	9.3 µg/L	No	3	A
27	Newburgh	8.9 µg/L	No	4	A
28	Morgantown	7.1 µg/L	No	9	C+
29	Bargersville	7.1 µg/L	No	0	B+
30	Greensburg	6.1 µg/L	No	29	D
31	Noblesville	5.4 µg/L	No	24	D
32	Evansville	4.8 µg/L	No	9	A-
33	Jasper	4.5 µg/L	No	7	A-
34	Valparaiso	4.4 µg/L	No	3	C-
35	Carmel	4.3 µg/L	No	2	B
36	Columbus	4.3 µg/L	No	22	B-
37	Otwell	3.2 µg/L	No	7	B
38	Dubois	3.0 µg/L	No	2	A
39	Ellettsville	3.0 µg/L	No	6	A-
40	Bristol	2.6 µg/L	No	9	D+
41	Jeffersonville	2.5 µg/L	No	4	B
42	Crawfordsville	2.5 µg/L	No	15	F
43	North Vernon	2.1 µg/L	No	106	D
44	Terre Haute	2.0 µg/L	No	8	F
45	Madison	2.0 µg/L	No	4	C+
46	Speedway	1.9 µg/L	No	2	C
47	Bloomington	1.8 µg/L	No	45	D
48	Boonville	1.8 µg/L	No	0	A+
49	East Chicago	1.8 µg/L	No	1	B-
50	Munster	1.4 µg/L	No	0	B+
51	Rensselaer	1.4 µg/L	No	2	B
52	Marion	1.4 µg/L	No	3	A
53	Austin	1.4 µg/L	No	27	C+
54	Logansport	1.3 µg/L	No	11	C
55	Dyer	1.3 µg/L	No	0	A-
56	Highland (Highlands)	1.3 µg/L	No	4	A
57	Michigan City	1.2 µg/L	No	12	F
58	Indianapolis	1.2 µg/L	No	31	C+
59	Muncie	1.2 µg/L	No	7	D
60	Shelbyville	1.2 µg/L	No	19	C+
61	Griffith	1.1 µg/L	No	2	B
62	Washington	1.0 µg/L	No	5	B
63	Bedford	0.9 µg/L	No	14	B-
64	Lanesville	0.8 µg/L	No	2	C+
65	Richmond	0.8 µg/L	No	1	B
66	Connersville	0.7 µg/L	No	4	C+
67	Brownstown	0.7 µg/L	No	2	B+
68	Anderson	0.6 µg/L	No	2	B
69	New Haven	0.5 µg/L	No	1	B+
70	Seymour	0.5 µg/L	No	3	B-
71	Clinton	0.5 µg/L	No	1	B
72	New Castle	0.5 µg/L	No	4	B+
73	Warsaw	0.4 µg/L	No	46	F

FAQ

Frequently asked questions about manganese in Indiana

Is manganese in Indiana tap water harmful?

The EPA secondary MCL for manganese is 50 µg/L, set primarily for aesthetic reasons (taste, color, staining). 14 cities in Indiana exceed the secondary MCL. However, emerging research links chronic manganese exposure above 50–100 µg/L to neurodevelopmental effects in children, including reduced IQ.

How can I remove manganese from my drinking water?

Oxidation filtration (such as greensand or birm filters) is the most common and effective method for removing manganese from well water. Water softeners using ion exchange also work well. Standard carbon filters provide limited manganese removal. If your water has a metallic taste or brown/black discoloration, manganese may be the cause.

What causes high manganese in Indiana water?

Manganese occurs naturally in groundwater and surface water, particularly in areas with iron-rich geology. Low dissolved oxygen conditions (common in deep wells and reservoir bottom waters) increase manganese solubility. Industrial sources include mining, steel production, and battery manufacturing. Seasonal changes in reservoir water chemistry can cause manganese spikes.

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