HAA5 Contamination

HAA5 in Oklahoma 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

26.4 µg/L

State Avg

▲ 6% vs national

vs National

351

Health Violations

Analysis

HAA5 in Oklahoma: what the data shows

Oklahoma has 58 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 26.4 µg/L — worse than the 15.5 µg/L national average. 4 cities exceed the EPA MCL of 60 µg/L. 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

Oklahoma

4 of 58 cities

→ ▲ 6% above national rate (worse)

National avg

23 of 4420 cities

City Map

HAA5 data across Oklahoma

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 Oklahoma

Highest HAA5 levels (µg/L)

All Cities

All Oklahoma cities ranked by haa5 level

#	City	Level	Exceeds?	Violations	Grade
1	Durant	164.1 µg/L	Yes	104	D
2	Madill	76.0 µg/L	Yes	178	F
3	Okmulgee	75.6 µg/L	Yes	262	D
4	Council Hill	65.6 µg/L	Yes	177	D+
5	Muskogee	53.6 µg/L	No	246	D
6	Spiro	53.1 µg/L	No	166	D+
7	Mcalester	51.6 µg/L	No	670	F
8	Idabel	50.3 µg/L	No	123	D
9	Claremore	48.0 µg/L	No	153	F
10	Atoka	45.6 µg/L	No	269	D+
11	Tahlequah	40.1 µg/L	No	56	F
12	Grove	39.8 µg/L	No	20	D
13	Midwest City	36.5 µg/L	No	11	B+
14	Sallisaw	35.4 µg/L	No	29	D+
15	Ardmore	35.0 µg/L	No	188	F
16	Moore	34.3 µg/L	No	53	F
17	El Reno	33.1 µg/L	No	49	D
18	Stillwater	32.5 µg/L	No	72	F
19	Crowder	31.1 µg/L	No	91	C+
20	Collinsville	29.6 µg/L	No	24	C+
21	Wewoka	29.4 µg/L	No	340	D+
22	Bixby	28.9 µg/L	No	1	B
23	Porum	28.8 µg/L	No	45	B-
24	Oklahoma City	28.0 µg/L	No	56	F
25	Broken Arrow	26.3 µg/L	No	113	F
26	Chickasha	24.0 µg/L	No	79	F
27	Bartlesville	23.2 µg/L	No	217	F
28	Yukon	23.1 µg/L	No	18	D
29	Sand Springs	23.0 µg/L	No	20	B
30	Jenks	23.0 µg/L	No	31	B-
31	Mustang	22.4 µg/L	No	9	C+
32	Duncan	20.9 µg/L	No	150	D+
33	Sapulpa	20.7 µg/L	No	85	D
34	Altus	18.6 µg/L	No	162	D
35	Shawnee	18.2 µg/L	No	124	D
36	Owasso	17.5 µg/L	No	8	C+
37	Skiatook	16.3 µg/L	No	72	B-
38	Tulsa	15.3 µg/L	No	6	D
39	Bethany	14.1 µg/L	No	14	B+
40	Norman	11.0 µg/L	No	52	F
41	Edmond	9.7 µg/L	No	86	F
42	Ponca City	9.7 µg/L	No	23	F
43	Elk City	7.3 µg/L	No	5	D
44	Okarche	5.4 µg/L	No	236	F
45	Stuart	4.7 µg/L	No	96	C-
46	Fort Sill	4.7 µg/L	No	4	A
47	Del City	4.4 µg/L	No	12	F
48	Calumet	4.3 µg/L	No	117	D
49	Lawton	4.2 µg/L	No	23	F
50	Enid	4.0 µg/L	No	33	F
51	Guymon	2.6 µg/L	No	10	A-
52	Weatherford	2.2 µg/L	No	71	D
53	Miami	1.7 µg/L	No	11	D
54	Ada	1.1 µg/L	No	6	B-
55	Woodward	1.0 µg/L	No	55	D
56	Harrah	0.8 µg/L	No	61	D
57	Allen	0.5 µg/L	No	5	A-
58	Guthrie	0.0 µg/L	No	45	F

FAQ

Frequently asked questions about haa5 in Oklahoma

What is HAA5 and why does it appear in Oklahoma 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. 4 cities in Oklahoma exceed the EPA MCL of 60 µg/L. The state average is 26.4 µg/L.

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

The cities with the highest average HAA5 concentrations in Oklahoma are: Durant (164.1 µg/L), Madill (76.0 µg/L), Okmulgee (75.6 µg/L), Council Hill (65.6 µg/L), Muskogee (53.6 µg/L). Note: this data is from UCMR 4 testing (2018–2020) and may not reflect current levels.

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