Copper Contamination

Copper in Iowa Drinking Water

Ranked by 90th percentile copper level (mg/L) · Data from EPA SDWIS & UCMR

103

Cities Tested

103

Exceeds Limit

100%

% Exceeds Limit

1.812 mg/L

State Avg

▼ 0% vs national

vs National

297

Health Violations

Analysis

Copper in Iowa: what the data shows

Iowa has 103 cities with copper monitoring data. The state average 90th percentile copper level is 1.812 mg/L, compared to 29.400 mg/L nationally — better than the national average. 103 cities exceed the EPA action level of 1.3 mg/L. Copper in drinking water typically comes from corrosion of copper pipes and plumbing fixtures, particularly in older homes. The EPA action level of 1.3 mg/L is the 90th percentile threshold — if more than 10% of tap samples exceed it, utilities must take corrective action including adjusting water chemistry to reduce corrosivity. Short-term copper exposure above the action level can cause gastrointestinal distress. Long-term exposure at elevated levels is associated with liver and kidney damage. Flushing your tap for 30 seconds before use and using an NSF 53-certified filter can reduce copper exposure.

Comparison

Cities exceeding 1.3 mg/L EPA Action Level

Iowa

100%

103 of 103 cities

← = Exactly at national rate

National avg

100%

3810 of 3810 cities

City Map

Copper data across Iowa

Each dot is a city, colored by overall water quality grade. Cities with copper levels above the 1.3 mg/L EPA action level are highlighted. Size reflects population served.

Worst Offenders

Top 10 cities by copper level in Iowa

Highest Copper levels (mg/L)

All Cities

All Iowa cities ranked by copper level

#	City	Level	Exceeds?	Violations	Grade
1	Clarinda	4.380 mg/L	Yes	48	B
2	Albert City	3.800 mg/L	Yes	0	A
3	Orange City	3.600 mg/L	Yes	0	A-
4	Johnston	3.200 mg/L	Yes	6	B+
5	Jewell	3.100 mg/L	Yes	0	B
6	Aplington	2.900 mg/L	Yes	1	A-
7	Essex	2.900 mg/L	Yes	15	A-
8	Ireton	2.800 mg/L	Yes	4	A-
9	Winterset	2.510 mg/L	Yes	20	A-
10	Maxwell	2.450 mg/L	Yes	0	A-
11	Luther	2.420 mg/L	Yes	8	A
12	Iowa City	2.400 mg/L	Yes	171	F
13	Rockwell City	2.300 mg/L	Yes	6	B+
14	Exira	2.300 mg/L	Yes	1	A-
15	Colfax	2.190 mg/L	Yes	2	A-
16	Adel	2.100 mg/L	Yes	2	A
17	Tripoli	2.080 mg/L	Yes	1	A-
18	Tabor	2.028 mg/L	Yes	0	A-
19	Sheldon	2.000 mg/L	Yes	0	A
20	South Amana	2.000 mg/L	Yes	1	A-
21	Woodbine	2.000 mg/L	Yes	3	B+
22	Riverside	2.000 mg/L	Yes	6	A-
23	Blairstown	1.960 mg/L	Yes	3	A-
24	Madrid	1.940 mg/L	Yes	4	A-
25	Hospers	1.920 mg/L	Yes	5	B+
26	Treynor	1.910 mg/L	Yes	0	A-
27	Sioux City	1.900 mg/L	Yes	14	B
28	North Liberty	1.900 mg/L	Yes	29	B-
29	Le Mars	1.900 mg/L	Yes	2	A
30	Kingsley	1.900 mg/L	Yes	3	A-
31	Lone Tree	1.900 mg/L	Yes	1	B+
32	George	1.900 mg/L	Yes	19	A-
33	Griswold	1.900 mg/L	Yes	2	A-
34	Ankeny	1.850 mg/L	Yes	15	B
35	Guttenberg	1.850 mg/L	Yes	0	A
36	Guthrie Center	1.820 mg/L	Yes	1	A-
37	Minden	1.820 mg/L	Yes	3	A-
38	Davenport	1.800 mg/L	Yes	2	C-
39	Muscatine	1.800 mg/L	Yes	46	F
40	Hull	1.800 mg/L	Yes	1	A-
41	Princeton	1.800 mg/L	Yes	18	B
42	Ventura	1.800 mg/L	Yes	0	A-
43	Pomeroy	1.800 mg/L	Yes	1	A-
44	Eldora	1.780 mg/L	Yes	0	A
45	Stanwood	1.780 mg/L	Yes	0	B+
46	Emmetsburg	1.770 mg/L	Yes	1	A-
47	Malvern	1.750 mg/L	Yes	2	B+
48	Nevada	1.740 mg/L	Yes	7	A
49	Rock Valley	1.700 mg/L	Yes	13	B+
50	Sanborn	1.700 mg/L	Yes	0	A
51	Middle Amana	1.700 mg/L	Yes	1	B+
52	Gilbert	1.700 mg/L	Yes	1	B+
53	Tama	1.680 mg/L	Yes	1	A-
54	Sidney	1.680 mg/L	Yes	1	B
55	Polk City	1.620 mg/L	Yes	0	B+
56	Boone	1.600 mg/L	Yes	9	B
57	Newell	1.600 mg/L	Yes	0	A
58	Doon	1.600 mg/L	Yes	32	B+
59	Carlisle	1.570 mg/L	Yes	0	A-
60	Fairfax	1.530 mg/L	Yes	2	A-
61	Dunkerton	1.530 mg/L	Yes	6	A-
62	Cambridge	1.520 mg/L	Yes	1	A-
63	Algona	1.510 mg/L	Yes	14	B
64	Ellsworth	1.510 mg/L	Yes	9	A-
65	Hiawatha	1.500 mg/L	Yes	12	B-
66	Solon	1.500 mg/L	Yes	157	F
67	Wapello	1.500 mg/L	Yes	12	B+
68	Moville	1.500 mg/L	Yes	11	A-
69	Remsen	1.500 mg/L	Yes	2	A-
70	Alden	1.500 mg/L	Yes	1	A
71	Shelby	1.500 mg/L	Yes	3	A-
72	Ogden	1.480 mg/L	Yes	3	A-
73	De Soto	1.480 mg/L	Yes	1	B
74	Neola	1.480 mg/L	Yes	8	B+
75	Fonda	1.480 mg/L	Yes	1	B+
76	Belle Plaine	1.470 mg/L	Yes	2	B+
77	Gilbertville	1.450 mg/L	Yes	0	A-
78	Sheffield	1.420 mg/L	Yes	2	A-
79	Boyden	1.420 mg/L	Yes	0	A-
80	Jefferson	1.410 mg/L	Yes	2	A
81	Eldridge	1.400 mg/L	Yes	9	B+
82	Rock Rapids	1.400 mg/L	Yes	12	B+
83	Sibley	1.400 mg/L	Yes	0	A-
84	Kalona	1.400 mg/L	Yes	3	B+
85	West Branch	1.400 mg/L	Yes	0	B
86	Ida Grove	1.400 mg/L	Yes	2	A-
87	Columbus Junction	1.400 mg/L	Yes	0	A-
88	Granger	1.400 mg/L	Yes	1	A-
89	Coon Rapids	1.400 mg/L	Yes	0	A
90	Alton	1.400 mg/L	Yes	1	A
91	Armstrong	1.400 mg/L	Yes	1	B+
92	Sutherland	1.400 mg/L	Yes	3	A-
93	Victor	1.390 mg/L	Yes	1	C+
94	Forest City	1.380 mg/L	Yes	8	B
95	Elkhart	1.380 mg/L	Yes	0	A-
96	Carroll	1.370 mg/L	Yes	0	B
97	Slater	1.370 mg/L	Yes	2	B+
98	Clermont	1.370 mg/L	Yes	4	B+
99	Anamosa	1.360 mg/L	Yes	5	B-
100	Osceola	1.360 mg/L	Yes	21	B
101	Williamsburg	1.360 mg/L	Yes	3	A-
102	Roland	1.360 mg/L	Yes	4	A
103	Dike	1.360 mg/L	Yes	2	A

FAQ

Frequently asked questions about copper in Iowa

Is copper in Iowa drinking water safe?

103 cities in Iowa exceed the EPA action level of 1.3 mg/L for copper. The state average is 1.812 mg/L. Copper levels are highest in homes with copper plumbing, particularly when water sits in pipes overnight. Flushing the tap before use significantly reduces copper in drinking water.

What causes high copper levels in Iowa tap water?

Copper typically leaches from copper pipes and brass fittings within homes, not from the water source itself. Corrosive (low pH or soft) water accelerates this leaching. Water utilities with high copper readings are required to adjust water chemistry to reduce corrosivity. You can reduce exposure by flushing your tap for 30 seconds before use.

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