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EWG's Tap Water Database — 2021 UPDATE

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Haloacetic acids (HAA5)

Acton MUD

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

 

96

Samples

0

Samples exceeding legal limit (MCL)

61

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20142.48 ppb1610ND - 9.10 ppb
20154.01 ppb169ND - 14.7 ppb
20163.01 ppb169ND - 15.0 ppb
20177.12 ppb1611ND - 32.3 ppb
20184.23 ppb1611ND - 17.8 ppb
20195.03 ppb1611ND - 20.4 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
2014-02-26Q14064460012.10 ppb
2014-02-26Q1406446004ND
2014-02-26Q1406446003ND
2014-02-26Q14064460023.00 ppb
2014-04-16Q1412086058ND
2014-04-16Q1412086057ND
2014-04-16Q14120860562.50 ppb
2014-04-16Q14120860552.60 ppb
2014-08-18Q14374170047.50 ppb
2014-08-18Q14374170037.60 ppb
2014-08-18Q14374170053.30 ppb
2014-08-18Q1437417006ND
2014-10-22Q1453502004ND
2014-10-22Q14535020031.000 ppb
2014-10-22Q14535020021.000 ppb
2014-10-22Q14535020019.10 ppb
2015-02-09Q1504919060ND
2015-02-09Q1504919059ND
2015-02-09Q15049190583.80 ppb
2015-02-09Q150491905714.7 ppb
2015-06-23Q15235400032.90 ppb
2015-06-23Q15235400041.000 ppb
2015-06-23Q1523540006ND
2015-06-23Q15235400053.70 ppb
2015-08-06Q15308810046.90 ppb
2015-08-06Q15308810037.60 ppb
2015-08-06Q153088100213.4 ppb
2015-08-06Q153088100110.1 ppb
2015-10-27Q1542356014ND
2015-10-27Q1542356013ND
2015-10-27Q1542356012ND
2015-10-27Q1542356011ND
2016-01-19Q16020840524.10 ppb
2016-01-19Q1602084051ND
2016-01-19Q1602084053ND
2016-01-19Q1602084054ND
2016-05-31Q1621309004ND
2016-05-31Q1621309003ND
2016-05-31Q16213090025.80 ppb
2016-05-31Q16213090014.20 ppb
2016-07-28Q16309510041.60 ppb
2016-07-28Q16309510032.40 ppb
2016-07-28Q16309510027.80 ppb
2016-07-28Q16309510016.20 ppb
2016-11-30Q16520010011.10 ppb
2016-11-30Q1652001003ND
2016-11-30Q1652001002ND
2016-11-30Q165200100715.0 ppb
2017-02-16Q17068090051.30 ppb
2017-02-16Q17068090043.10 ppb
2017-02-16Q170680900332.3 ppb
2017-02-16Q170680900231.3 ppb
2017-05-08Q17187460051.60 ppb
2017-05-08Q1718746004ND
2017-05-08Q17187460038.70 ppb
2017-05-08Q17187460028.90 ppb
2017-07-17Q17292140024.10 ppb
2017-07-17Q17292140014.00 ppb
2017-07-17Q1729214003ND
2017-07-17Q1729214004ND
2017-10-05Q1749124052ND
2017-10-05Q1749124018ND
2017-10-05Q174912405112.3 ppb
2017-10-05Q17491240506.30 ppb
2018-02-15Q1806602004ND
2018-02-15Q1806602003ND
2018-02-15Q18066020022.70 ppb
2018-02-15Q18066020014.00 ppb
2018-05-01Q18173720228.90 ppb
2018-05-01Q18173720232.90 ppb
2018-05-01Q18173720251.20 ppb
2018-05-01Q1817372024ND
2018-07-23Q18290490042.70 ppb
2018-07-23Q18290490022.60 ppb
2018-07-23Q18290490014.80 ppb
2018-07-23Q18290490035.80 ppb
2018-12-11Q1850865003ND
2018-12-11Q1850865007ND
2018-12-11Q185086500214.2 ppb
2018-12-11Q185086500617.8 ppb
2019-01-10Q190150601311.0 ppb
2019-01-10Q190150600120.4 ppb
2019-01-10Q1901506007ND
2019-01-10Q1901506014ND
2019-04-18Q1915698008ND
2019-04-18Q19156980074.50 ppb
2019-04-18Q19156980065.40 ppb
2019-05-15Q1925754001ND
2019-09-04Q19621650041.20 ppb
2019-09-04Q19621650033.40 ppb
2019-09-04Q19621650028.40 ppb
2019-09-04Q19621650017.10 ppb
2019-10-29Q19743660018.00 ppb
2019-10-29Q1974366004ND
2019-10-29Q19743660033.00 ppb
2019-10-29Q19743660028.00 ppb