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EWG's Tap Water Database — 2019 UPDATE

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Haloacetic acids (HAA5)

Homer

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.

 

36

Samples

0

Samples exceeding legal limit (MCL)

20

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
201243.5 ppb161624.0 ppb - 73.1 ppb
20133.75 ppb41ND - 15.0 ppb
20144.91 ppb84ND - 12.3 ppb
20151.49 ppb84ND - 7.10 ppb
20166.16 ppb85ND - 21.9 ppb
201714.0 ppb86ND - 29.0 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 on-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
2013-09-04AI14311ND
2013-09-04AI1431015.0 ppb
2013-12-09AI24271ND
2013-12-09AI24270ND
2014-03-04AI29159ND
2014-03-04AI29158ND
2014-06-02AI42074ND
2014-06-02AI4207312.3 ppb
2014-09-04AI5248610.7 ppb
2014-09-04AI524878.30 ppb
2014-12-08AI60853ND
2014-12-08AI608528.00 ppb
2015-03-04AI663651.10 ppb
2015-03-04AI663641.10 ppb
2015-06-02AI78551ND
2015-06-02AI78550ND
2015-09-03AI88767ND
2015-09-03AI887667.10 ppb
2015-12-03AJ01952ND
2015-12-03AJ019512.60 ppb
2016-03-02AJ07373ND
2016-03-02AJ073723.40 ppb
2016-06-06AJ13544ND
2016-06-06AJ1354321.9 ppb
2016-09-06AJ256942.00 ppb
2016-09-06AJ2569315.8 ppb
2016-12-13AJ367996.20 ppb
2016-12-13AJ36800ND
2017-03-06AJ47438ND
2017-03-06AJ474374.20 ppb
2017-06-05AJ56628ND
2017-06-05AJ566275.90 ppb
2017-09-05AJ6680829.0 ppb
2017-09-05AJ6680723.9 ppb
2017-12-04AJ7456428.0 ppb
2017-12-04AJ7456320.6 ppb