Know Your Environment. Protect Your Health.

Haloacetic acids (HAA5)

Harris County Municipal Utility District 344

Haloacetic acids are formed when disinfectants such as chlorine are added to tap water. The group of five haloacetic acids regulated by federal standards includes monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid and dibromoacetic acid. Read More.

Haloacetic acids are harmful during pregnancy and may increase the risk of cancer. Haloacetic acids are� genotoxic, which means that they induce mutations and DNA damage. Multiple studies by the National Toxicology Program have demonstrated the cancer-causing properties of individual haloacetic acids in laboratory animals. The Department of Health and Human Services is currently considering listing di- or tri-haloacetic acids for possible inclusion in its comprehensive Report on Carcinogens.

Click here to read more about disinfection byproducts.

 

32

Samples

0

Samples exceeding legal limit (MCL)

24

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20182.60 ppb42ND - 7.30 ppb
20196.53 ppb43ND - 14.2 ppb
20200.300 ppb41ND - 1.20 ppb
20216.23 ppb443.90 ppb - 8.80 ppb
20228.71 ppb87ND - 13.3 ppb
20235.44 ppb87ND - 12.6 ppb

ppb = parts per billion

State, National, and Health Guidelines for Drinking Water

EWG Health Guideline: 0.1 ppb

The EWG Health Guideline of 0.1 ppb for the group of five haloacetic acids, or HAA5, was defined in a peer-reviewed scientific study by EWG and represents a one-in-a-million lifetime cancer risk level. This health guideline protects against cancer.

EPA Maximum Contaminant
Level (MCL): 60 ppb

The legal limit for the group of five haloacetic acids (HAA5), established in 1998, was based on the need for residual disinfectant levels in water served to customers and the cost of treatment. This limit does not fully protect against the risk of cancer and harm to the developing fetus due to exposure to haloacetic acids.

ppb = parts per billion

All test results

Date Lab ID Result
2018-02-26AE153567.30 ppb
2018-06-08AE29203ND
2018-09-12AE397633.10 ppb
2018-11-27AE46973ND
2019-02-11AE5375410.6 ppb
2019-06-19AE7127514.2 ppb
2019-08-26AE80573ND
2019-12-09AE916491.30 ppb
2020-02-12AE98099ND
2020-05-11AF10339ND
2020-09-03AF264381.20 ppb
2020-11-09AF33694ND
2021-03-04AF453394.70 ppb
2021-06-04AF566347.50 ppb
2021-08-12AF661718.80 ppb
2021-11-03AF755553.90 ppb
2022-02-07AF8324313.3 ppb
2022-02-07AF8326910.6 ppb
2022-05-13AF9691612.2 ppb
2022-05-13AF9691713.3 ppb
2022-09-15AG131881.60 ppb
2022-09-15AG13217ND
2022-12-22AG227187.90 ppb
2022-12-22AG2271910.8 ppb
2023-03-09Q230956600312.6 ppb
2023-03-09Q230956600412.1 ppb
2023-04-27AG38407ND
2023-04-27AG384082.50 ppb
2023-07-25AG499912.80 ppb
2023-07-25AG499969.50 ppb
2023-11-13AG633391.90 ppb
2023-11-13AG633422.10 ppb