HAA5 Contamination

HAA5 in Iowa Drinking Water

Ranked by average HAA5 concentration (µg/L) · UCMR 4 data (2018–2020) · Data from EPA SDWIS & UCMR

Cities Tested

Exceeds Limit

% Exceeds Limit

8.6 µg/L

State Avg

▼ 1% vs national

vs National

303

Health Violations

Analysis

HAA5 in Iowa: what the data shows

Iowa has 54 cities with HAA5 monitoring data from the EPA's UCMR 4 program (2018–2020). Haloacetic acids (HAA5) form when chlorine-based disinfectants react with natural organic matter in water. The state average is 8.6 µg/L — better than the 15.5 µg/L national average. No cities currently exceed the 60 µg/L EPA MCL. HAA5 is a group of five chlorinated and brominated acetic acids. Long-term exposure above the MCL is associated with increased cancer risk and adverse reproductive outcomes. The EPA classifies total HAA5 as a probable human carcinogen at elevated concentrations. Activated carbon filtration (especially granular or block carbon) is effective at reducing HAA5. Running water through a refrigerator filter or letting it sit in an open pitcher for 30 minutes also helps, as some HAA5 species are volatile. Boiling does not remove disinfection byproducts and may concentrate them.

Comparison

Cities exceeding 60 µg/L EPA MCL

Iowa

0 of 54 cities

← ▼ 1% below national rate (better)

National avg

23 of 4420 cities

City Map

HAA5 data across Iowa

Each dot is a city with UCMR 4 HAA5 testing data. Cities where average HAA5 exceeded the 60 µg/L EPA MCL are highlighted. Size reflects population served.

Worst Offenders

Top 10 cities by haa5 level in Iowa

Highest HAA5 levels (µg/L)

All Cities

All Iowa cities ranked by haa5 level

#	City	Level	Exceeds?	Violations	Grade
1	Sioux City	29.5 µg/L	No	14	B
2	Jefferson	26.0 µg/L	No	2	A
3	Spirit Lake	25.7 µg/L	No	4	A
4	Keokuk	25.1 µg/L	No	0	A-
5	Davenport	24.1 µg/L	No	2	C-
6	Creston	24.1 µg/L	No	9	A-
7	Moulton	21.9 µg/L	No	1	A-
8	Centerville	18.5 µg/L	No	4	B+
9	Burlington	18.1 µg/L	No	7	B+
10	Ruthven	17.6 µg/L	No	0	A-
11	Council Bluffs	15.8 µg/L	No	8	B+
12	Winterset	14.5 µg/L	No	20	A-
13	Ottumwa	13.9 µg/L	No	6	B+
14	Iowa City	12.1 µg/L	No	171	F
15	Ankeny	11.9 µg/L	No	15	B
16	Sloan	11.1 µg/L	No	0	A
17	Boone	10.9 µg/L	No	9	B
18	Dubuque	9.5 µg/L	No	30	F
19	Johnston	9.0 µg/L	No	6	B+
20	Waukee	8.8 µg/L	No	13	A-
21	Urbandale	8.7 µg/L	No	0	B+
22	Oskaloosa	8.6 µg/L	No	11	A-
23	Manning	8.3 µg/L	No	4	A-
24	Des Moines	8.0 µg/L	No	7	B+
25	Brooklyn	7.8 µg/L	No	10	A+
26	Indianola	6.7 µg/L	No	7	A-
27	Clive	6.7 µg/L	No	1	A
28	West Des Moines	5.7 µg/L	No	1	B+
29	Dallas Center	5.5 µg/L	No	0	A
30	Spencer	5.4 µg/L	No	1	A
31	Rock Valley	5.1 µg/L	No	13	B+
32	Newton	4.9 µg/L	No	2	A
33	Waverly	3.9 µg/L	No	2	B+
34	Muscatine	3.8 µg/L	No	46	F
35	Coralville	3.4 µg/L	No	15	B
36	Cedar Rapids	3.3 µg/L	No	31	D
37	Altoona	3.0 µg/L	No	20	B+
38	Fort Dodge	2.9 µg/L	No	19	D+
39	Carroll	2.3 µg/L	No	0	B
40	Waterloo	2.0 µg/L	No	3	A-
41	Ainsworth	2.0 µg/L	No	1	A
42	Cedar Falls	1.6 µg/L	No	4	A-
43	Rockford	1.3 µg/L	No	1	A+
44	Ames	1.2 µg/L	No	15	B+
45	Red Oak	1.1 µg/L	No	9	A-
46	Fayette	1.1 µg/L	No	0	A-
47	Fort Madison	1.0 µg/L	No	6	A-
48	Mason City	1.0 µg/L	No	18	A-
49	Storm Lake	0.8 µg/L	No	1	A-
50	Marshalltown	0.6 µg/L	No	4	A-
51	Clinton	0.6 µg/L	No	0	A-
52	Pella	0.3 µg/L	No	4	A-
53	North Liberty	0.1 µg/L	No	29	B-
54	Marion	0.0 µg/L	No	6	A-

FAQ

Frequently asked questions about haa5 in Iowa

What is HAA5 and why does it appear in Iowa tap water?

HAA5 (haloacetic acids) are disinfection byproducts that form when chlorine reacts with naturally occurring organic matter in source water. They are a normal byproduct of the disinfection process that makes water safe to drink. No cities in Iowa currently exceed the 60 µg/L EPA MCL. The state average is 8.6 µg/L.

How can I reduce HAA5 exposure from Iowa drinking water?

Activated carbon filters (granular or block) effectively reduce HAA5. Refrigerator filters and under-sink carbon systems are convenient options. Unlike lead or PFAS, HAA5 levels can also be reduced by letting water stand in an open container, as some species evaporate. Boiling does NOT remove HAA5 and can concentrate them by reducing water volume.

Which Iowa cities have the highest HAA5 levels?

The cities with the highest average HAA5 concentrations in Iowa are: Sioux City (29.5 µg/L), Jefferson (26.0 µg/L), Spirit Lake (25.7 µg/L), Keokuk (25.1 µg/L), Davenport (24.1 µg/L). Note: this data is from UCMR 4 testing (2018–2020) and may not reflect current levels.

More contaminants