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EWG's Tap Water Database — 2021 UPDATE

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Haloacetic acids (HAA5)

Calico Rock

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

 

49

Samples

0

Samples exceeding legal limit (MCL)

10

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20143.45 ppb117ND - 18.0 ppb
2015ND80ND
2016ND80ND
2017ND80ND
2018ND60ND
20191.74 ppb83ND - 6.90 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
2014-03-181407900460118.0 ppb
2014-03-18140790045013.60 ppb
2014-03-18140790044013.10 ppb
2014-05-2714149007401ND
2014-05-27141490076015.90 ppb
2014-05-2714149007501ND
2014-08-25142390031011.20 ppb
2014-08-25142390032014.70 ppb
2014-08-25142390030011.40 ppb
2014-10-1414288001601ND
2014-10-1414288001201ND
2015-01-1315015002301ND
2015-01-1315015002001ND
2015-04-1415106002901ND
2015-04-1415106002701ND
2015-07-1415196000801ND
2015-07-1415196000901ND
2015-10-1415289005701ND
2015-10-1415289005901ND
2016-02-1616049002901ND
2016-02-1616049002801ND
2016-05-2416147008501ND
2016-05-2416147008601ND
2016-07-1216196017701ND
2016-07-1216196017401ND
2016-10-1116287009601ND
2016-10-1116287009701ND
2017-01-1017012009701ND
2017-01-1017012009901ND
2017-04-1117103002601ND
2017-04-1117103002301ND
2017-07-1117194009901ND
2017-07-1117194009601ND
2017-10-1017285011501ND
2017-10-1017285011601ND
2018-01-0918010002902ND
2018-01-0918010003002ND
2018-04-1118102005701ND
2018-04-1118102005901ND
2018-07-1018193011101ND
2018-07-1018193011301ND
2019-01-1519016002301ND
2019-01-15190160024011.40 ppb
2019-04-0919100002301ND
2019-04-0919100002601ND
2019-07-3119214000402ND
2019-07-3119214000302ND
2019-10-08192820021016.90 ppb
2019-10-08192820019015.60 ppb