Menu

EWG's Tap Water Database — 2021 UPDATE

Donate

Haloacetic acids (HAA5)

Monrovia Water Department

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

 

97

Samples

0

Samples exceeding legal limit (MCL)

37

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.819 ppb167ND - 3.20 ppb
20150.663 ppb166ND - 2.40 ppb
20160.963 ppb168ND - 3.60 ppb
20170.394 ppb164ND - 2.00 ppb
20180.535 ppb176ND - 2.00 ppb
20190.619 ppb166ND - 2.30 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
2014-01-319588-802-1000ND
2014-01-319588-800-1015ND
2014-01-319588-801-10301.50 ppb
2014-01-319588-803-1045ND
2014-04-309588-803-0825ND
2014-04-309588-802-0945ND
2014-04-309588-801-08501.90 ppb
2014-04-309588-800-0840ND
2014-07-319588-803-1100ND
2014-07-319588-802-0950ND
2014-07-319588-801-10453.20 ppb
2014-07-319588-800-1015ND
2014-10-319588-802-10051.50 ppb
2014-10-319588-801-09202.20 ppb
2014-10-319588-803-09001.60 ppb
2014-10-319588-800-09101.20 ppb
2015-01-299588-803-0745ND
2015-01-299588-802-0855ND
2015-01-299588-801-08101.90 ppb
2015-01-299588-800-07551.10 ppb
2015-04-309588-803-1020ND
2015-04-309588-802-0800ND
2015-04-309588-800-0955ND
2015-04-309588-801-10052.40 ppb
2015-07-319588-801-08102.10 ppb
2015-07-319588-800-0755ND
2015-07-319588-803-0745ND
2015-07-319588-802-09101.10 ppb
2015-10-299588-801-08152.00 ppb
2015-10-299588-800-0750ND
2015-10-299588-803-0830ND
2015-10-299588-802-1115ND
2016-01-289588-801-08251.90 ppb
2016-01-289588-800-0815ND
2016-01-289588-803-0800ND
2016-01-289588-802-1040ND
2016-04-289588-801-08302.10 ppb
2016-04-289588-800-0820ND
2016-04-289588-803-08101.000 ppb
2016-04-289588-802-0830ND
2016-07-289588-801-08253.60 ppb
2016-07-289588-800-0810ND
2016-07-289588-803-07551.90 ppb
2016-07-289588-802-09101.10 ppb
2016-10-289588-800-0810ND
2016-10-289588-802-0905ND
2016-10-289588-803-07551.50 ppb
2016-10-289588-801-08202.30 ppb
2017-01-309588-801-08101.50 ppb
2017-01-309588-800-0800ND
2017-01-309588-802-0910ND
2017-01-309588-803-0745ND
2017-04-289588-801-08101.50 ppb
2017-04-289588-800-0825ND
2017-04-289588-803-0745ND
2017-04-289588-802-0910ND
2017-07-319588-803-0855ND
2017-07-319588-801-08402.00 ppb
2017-07-319588-800-0820ND
2017-07-319588-802-0915ND
2017-10-319588-803-07551.30 ppb
2017-10-319588-801-0820ND
2017-10-319588-800-0810ND
2017-10-319588-802-0930ND
2018-01-319588-801-08301.30 ppb
2018-01-319588-803-0800ND
2018-01-319588-800-0815ND
2018-01-319588-802-0925ND
2018-02-209588-800-0755ND
2018-04-279588-802-09001.30 ppb
2018-04-279588-801-07552.00 ppb
2018-04-279588-803-07351.10 ppb
2018-04-279588-800-0745ND
2018-07-309588-801-08151.70 ppb
2018-07-309588-803-0745ND
2018-07-309588-802-0910ND
2018-07-309588-800-0800ND
2018-10-309588-803-0820ND
2018-10-309588-801-08451.70 ppb
2018-10-309588-800-0830ND
2018-10-309588-802-0930ND
2019-01-299588-800-0830ND
2019-01-299588-802-0935ND
2019-01-299588-801-08401.20 ppb
2019-01-299588-803-0815ND
2019-04-299588-801-08301.90 ppb
2019-04-299588-800-0820ND
2019-04-299588-803-0805ND
2019-04-299588-802-0915ND
2019-07-299588-801-07402.00 ppb
2019-07-299588-800-0730ND
2019-07-299588-802-0830ND
2019-07-299588-803-07151.20 ppb
2019-10-299588-801-08002.30 ppb
2019-10-299588-802-0905ND
2019-10-299588-800-0745ND
2019-10-299588-803-07351.30 ppb