Know Your Environment. Protect Your Health.

Haloacetic acids (HAA5)

City of West

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.

 

48

Samples

2

Samples exceeding legal limit (MCL)

30

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20189.84 ppb84ND - 39.4 ppb
201917.6 ppb85ND - 63.1 ppb
202024.2 ppb87ND - 124.0 ppb
20218.60 ppb85ND - 18.9 ppb
202210.9 ppb85ND - 27.3 ppb
20239.73 ppb84ND - 23.5 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
2018-02-13AE13520ND
2018-02-13AE135199.80 ppb
2018-05-02AE24777ND
2018-05-02AE2475511.8 ppb
2018-07-17AE33564ND
2018-07-17AE3356617.7 ppb
2018-10-11AE43219ND
2018-10-11AE4322539.4 ppb
2019-03-12AE580231.50 ppb
2019-03-12AE5803012.5 ppb
2019-04-18AE62944ND
2019-04-18AE6294512.3 ppb
2019-08-12AE77973ND
2019-08-12AE7797163.1 ppb
2019-11-04AE88287ND
2019-11-04AE8829051.1 ppb
2020-02-18AE986591.000 ppb
2020-02-18AE9866032.8 ppb
2020-05-05AF09306ND
2020-05-05AF0930723.9 ppb
2020-08-25AF250061.000 ppb
2020-08-25AF250079.40 ppb
2020-12-02AF36224124.0 ppb
2020-12-02AF362251.20 ppb
2021-03-16AF470443.20 ppb
2021-03-16AF4704516.2 ppb
2021-05-11AF53213ND
2021-06-01AF5603218.9 ppb
2021-08-10AF6557016.1 ppb
2021-08-10AF65572ND
2021-10-26AF7467314.4 ppb
2021-10-26AF74675ND
2022-02-17AF85482ND
2022-02-17AF8548415.1 ppb
2022-06-02AF99309ND
2022-06-02AF9931222.0 ppb
2022-08-10AG085073.80 ppb
2022-08-10AG0850827.3 ppb
2022-11-22AG19588ND
2022-11-22AG1961318.9 ppb
2023-03-15AG33076ND
2023-03-15AG3307713.3 ppb
2023-05-18AG41005ND
2023-05-18AG4100623.5 ppb
2023-08-22AG53406ND
2023-08-22AG5340820.4 ppb
2023-10-05AG5860320.6 ppb
2023-10-05AG58605ND