HAA5 Contamination

HAA5 in Missouri 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

12.6 µg/L

State Avg

▼ 1% vs national

vs National

426

Health Violations

Analysis

HAA5 in Missouri: what the data shows

Missouri has 88 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 12.6 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

Missouri

0 of 88 cities

← ▼ 1% below national rate (better)

National avg

23 of 4420 cities

City Map

HAA5 data across Missouri

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 Missouri

Highest HAA5 levels (µg/L)

All Cities

All Missouri cities ranked by haa5 level

#	City	Level	Exceeds?	Violations	Grade
1	Higginsville	37.2 µg/L	No	17	B+
2	Bowling Green	36.1 µg/L	No	7	B+
3	Joplin	35.5 µg/L	No	53	F
4	Hannibal	33.9 µg/L	No	34	C+
5	Maryville	33.4 µg/L	No	21	C+
6	Moberly	32.7 µg/L	No	14	A-
7	Kirksville	30.7 µg/L	No	15	A-
8	Arnold	30.0 µg/L	No	0	B
9	Poplar Bluff	29.7 µg/L	No	47	C
10	Kirkwood	28.6 µg/L	No	0	A+
11	Macon	27.9 µg/L	No	11	A-
12	Bunn	27.6 µg/L	No	38	F
13	Bunn	27.6 µg/L	No	17	C+
14	Barnhart	27.2 µg/L	No	1	A-
15	Neosho	26.5 µg/L	No	21	C-
16	Unionville	24.7 µg/L	No	22	B-
17	Fort Leonard Wood	24.3 µg/L	No	0	A+
18	Excelsior Spgs.	24.1 µg/L	No	3	B+
19	Branson	24.0 µg/L	No	70	D
20	Marshall	22.3 µg/L	No	33	B-
21	Lathrop	22.3 µg/L	No	3	B
22	St. Louis	22.0 µg/L	No	28	F
23	Belton	20.8 µg/L	No	5	B-
24	Chesterfield	20.5 µg/L	No	11	B-
25	Springfield	20.2 µg/L	No	59	F
26	St. Peters	19.1 µg/L	No	0	B+
27	Festus	18.5 µg/L	No	20	C
28	Raymoor	18.3 µg/L	No	4	A
29	Wentzville	17.8 µg/L	No	9	A-
30	High Ridge	16.9 µg/L	No	15	B-
31	High Ridge	16.9 µg/L	No	1	A
32	High Ridge	16.9 µg/L	No	1	A
33	St. Charles	16.0 µg/L	No	0	B+
34	Des Peres	15.4 µg/L	No	2149	F
35	Kansas City	14.9 µg/L	No	1	B
36	Kewanee	14.7 µg/L	No	1	B+
37	Waldron	14.2 µg/L	No	0	A-
38	Blue Springs	13.9 µg/L	No	0	B+
39	Jefferson City	13.9 µg/L	No	19	B+
40	Gladstone	13.4 µg/L	No	0	B+
41	Raytown	12.5 µg/L	No	2	B+
42	O Fallon	11.7 µg/L	No	10	F
43	Odessa	10.3 µg/L	No	14	A
44	Cape Girardeau	9.2 µg/L	No	127	D
45	St. Joseph	8.6 µg/L	No	1	A-
46	St. Joseph	8.6 µg/L	No	0	A-
47	St. Joseph	8.6 µg/L	No	0	A-
48	St. Joseph	8.6 µg/L	No	0	A-
49	St. Joseph	8.6 µg/L	No	0	A-
50	Parkville	8.1 µg/L	No	0	B+
51	Brunswick	7.8 µg/L	No	0	B+
52	Columbia	7.7 µg/L	No	52	C
53	West Plains	7.4 µg/L	No	15	B+
54	Lees Summit	7.1 µg/L	No	1	B+
55	Kennett	5.8 µg/L	No	1	B
56	Grandview	5.3 µg/L	No	0	A-
57	Savannah	5.1 µg/L	No	1	A
58	Sikeston	4.7 µg/L	No	5	B
59	Ozark	4.7 µg/L	No	65	F
60	Grain Valley	4.3 µg/L	No	1	A
61	Independence	2.9 µg/L	No	0	B
62	Mexico	2.2 µg/L	No	0	A-
63	Liberty	2.0 µg/L	No	8	C+
64	Rolla	1.8 µg/L	No	32	D
65	Holden	1.7 µg/L	No	8	A
66	Webb City	1.2 µg/L	No	8	A-
67	California	1.2 µg/L	No	5	A-
68	Fulton	1.0 µg/L	No	13	B+
69	Jane	0.8 µg/L	No	1	A-
70	Sedalia	0.7 µg/L	No	60	F
71	Carthage	0.7 µg/L	No	21	D+
72	Farmington	0.6 µg/L	No	251	D
73	Bolivar	0.6 µg/L	No	31	B
74	Republic	0.5 µg/L	No	5	A-
75	Troy	0.5 µg/L	No	87	F
76	Winfield	0.5 µg/L	No	35	B-
77	Beverly Hills	0.4 µg/L	No	4	B-
78	Beverly Hills	0.4 µg/L	No	3	B+
79	Washington	0.3 µg/L	No	31	C+
80	Warrensburg	0.2 µg/L	No	0	B+
81	Jackson	0.2 µg/L	No	72	C+
82	Desloge	0.2 µg/L	No	0	B+
83	Cabool	0.1 µg/L	No	1	A-
84	Lebanon	0.1 µg/L	No	16	B
85	Nixa	0.1 µg/L	No	33	C
86	Battlefield	0.0 µg/L	No	11	A-
87	Stockton	0.0 µg/L	No	49	D
88	Summerfield	0.0 µg/L	No	7	C

FAQ

Frequently asked questions about haa5 in Missouri

What is HAA5 and why does it appear in Missouri 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 Missouri currently exceed the 60 µg/L EPA MCL. The state average is 12.6 µg/L.

How can I reduce HAA5 exposure from Missouri 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 Missouri cities have the highest HAA5 levels?

The cities with the highest average HAA5 concentrations in Missouri are: Higginsville (37.2 µg/L), Bowling Green (36.1 µg/L), Joplin (35.5 µg/L), Hannibal (33.9 µg/L), Maryville (33.4 µg/L). Note: this data is from UCMR 4 testing (2018–2020) and may not reflect current levels.

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