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EWG's Tap Water Database — 2021 UPDATE

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Haloacetic acids (HAA5)

Harris County MUD 157

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.

MORE ABOUT THIS CONTAMINANT

 

78

Samples

0

Samples exceeding legal limit (MCL)

16

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND20ND
20157.40 ppb124ND - 33.2 ppb
20160.281 ppb164ND - 1.20 ppb
20170.0813 ppb161ND - 1.30 ppb
20180.144 ppb162ND - 1.20 ppb
20190.381 ppb165ND - 1.40 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

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
2014-06-16AC56959ND
2014-06-16AC56958ND
2015-05-15AC92261ND
2015-05-15AC92291ND
2015-05-15AC92260ND
2015-05-15AC92250ND
2015-07-28AD01200ND
2015-07-28AD01229ND
2015-07-28AD01206ND
2015-07-28AD01204ND
2015-12-07AD1568533.2 ppb
2015-12-07AD1571231.2 ppb
2015-12-07AD1570923.2 ppb
2015-12-07AD157111.20 ppb
2016-02-11AD23331ND
2016-02-11AD23332ND
2016-02-11AD23328ND
2016-02-11AD23333ND
2016-04-27AD34407ND
2016-04-27AD34409ND
2016-04-27AD344081.20 ppb
2016-04-27AD34401ND
2016-09-16AD50005ND
2016-09-16AD49978ND
2016-09-16AD49976ND
2016-09-16AD49981ND
2016-11-18AD587871.10 ppb
2016-11-18AD587851.000 ppb
2016-11-18AD58784ND
2016-11-18AD587831.20 ppb
2017-02-15AD70825ND
2017-02-15AD70827ND
2017-02-15AD70822ND
2017-02-15AD70829ND
2017-05-17AD84630ND
2017-05-17AD84631ND
2017-05-17AD84623ND
2017-05-17AD84624ND
2017-08-16AD93192ND
2017-08-16AD93193ND
2017-08-16AD93194ND
2017-08-16AD93195ND
2017-10-24AE01779ND
2017-10-24AE01777ND
2017-10-24AE017611.30 ppb
2017-10-24AE01775ND
2018-02-05AE12174ND
2018-02-05AE12164ND
2018-02-05AE12143ND
2018-02-05AE12138ND
2018-05-03AE25037ND
2018-05-03AE25032ND
2018-05-03AE250331.10 ppb
2018-05-03AE25038ND
2018-08-22AE38067ND
2018-08-22AE38065ND
2018-08-22AE38063ND
2018-08-22AE38064ND
2018-11-19AE46444ND
2018-11-19AE46449ND
2018-11-19AE464461.20 ppb
2018-11-19AE46467ND
2019-02-20AE55009ND
2019-02-20AE55008ND
2019-02-20AE550041.10 ppb
2019-02-20AE55007ND
2019-06-05AE692411.40 ppb
2019-06-05AE69239ND
2019-06-05AE692381.30 ppb
2019-06-05AE692401.20 ppb
2019-08-14AE78587ND
2019-08-14AE78584ND
2019-08-14AE78588ND
2019-08-14AE78585ND
2019-10-02AE85502ND
2019-10-02AE854981.10 ppb
2019-10-02AE85501ND
2019-10-02AE85503ND