Know Your Environment. Protect Your Health.

Haloacetic acids (HAA5)

Rice University

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.

 

46

Samples

0

Samples exceeding legal limit (MCL)

19

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20187.68 ppb85ND - 26.9 ppb
201913.1 ppb87ND - 31.7 ppb
202015.3 ppb85ND - 42.1 ppb
2021ND80ND
20223.89 ppb82ND - 16.6 ppb
2023ND60ND

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
2018-01-11AE08912ND
2018-03-13AE181292.10 ppb
2018-04-03AE210063.70 ppb
2018-04-03AE209743.20 ppb
2018-07-09AE3259125.5 ppb
2018-07-09AE3259526.9 ppb
2018-10-10AE43071ND
2018-10-10AE43072ND
2019-01-16AE501141.40 ppb
2019-01-16AE501171.60 ppb
2019-04-04AE611943.20 ppb
2019-04-04AE61195ND
2019-07-09AE7364021.1 ppb
2019-07-09AE7366531.7 ppb
2019-11-15AE8951520.5 ppb
2019-11-15AE8951724.9 ppb
2020-02-07AE975921.40 ppb
2020-02-07AE97595ND
2020-04-27AF0823442.1 ppb
2020-04-27AF0823634.3 ppb
2020-07-23AF2043220.8 ppb
2020-07-23AF2043423.5 ppb
2020-10-22AF31647ND
2020-10-22AF31646ND
2021-02-08AF42911ND
2021-02-08AF42912ND
2021-04-13AF49943ND
2021-04-13AF49946ND
2021-08-25AF67912ND
2021-08-25AF67916ND
2021-10-25AF74461ND
2021-10-25AF74462ND
2022-02-02AF83245ND
2022-02-02AF83246ND
2022-05-02AF95056ND
2022-05-02AF95057ND
2022-09-09AG12372ND
2022-09-09AG12374ND
2022-10-12AG1681114.5 ppb
2022-10-12AG1682416.6 ppb
2023-02-02AG27106ND
2023-02-02AG27107ND
2023-04-21AG37646ND
2023-04-21AG37647ND
2023-08-16AG52811ND
2023-08-16AG52829ND