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EWG's Tap Water Database — 2021 UPDATE

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Haloacetic acids (HAA5)

Mesa Water District

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

 

192

Samples

0

Samples exceeding legal limit (MCL)

153

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
20147.58 ppb3229ND - 14.0 ppb
20153.49 ppb3226ND - 6.80 ppb
20163.03 ppb3221ND - 7.50 ppb
20174.75 ppb3227ND - 9.60 ppb
20183.32 ppb3226ND - 7.00 ppb
20194.16 ppb3224ND - 7.70 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
2014-02-119590-801-07557.10 ppb
2014-02-119590-802-08106.20 ppb
2014-02-119590-803-08258.50 ppb
2014-02-119590-804-09503.10 ppb
2014-02-119590-805-1020ND
2014-02-119590-806-11405.40 ppb
2014-02-119590-807-11505.30 ppb
2014-02-119590-808-12055.30 ppb
2014-05-139590-801-08159.40 ppb
2014-05-139590-802-083013.0 ppb
2014-05-139590-803-084512.0 ppb
2014-05-139590-804-0940ND
2014-05-139590-805-10109.20 ppb
2014-05-139590-806-11159.20 ppb
2014-05-139590-807-112510.00 ppb
2014-05-139590-808-11408.90 ppb
2014-08-149590-801-095514.0 ppb
2014-08-149590-802-10109.30 ppb
2014-08-149590-803-10258.00 ppb
2014-08-149590-804-11404.10 ppb
2014-08-149590-805-121013.0 ppb
2014-08-149590-806-132513.0 ppb
2014-08-149590-807-133513.0 ppb
2014-08-149590-808-135514.0 ppb
2014-11-129590-801-08256.90 ppb
2014-11-129590-802-08355.70 ppb
2014-11-129590-803-08503.20 ppb
2014-11-129590-804-10003.60 ppb
2014-11-129590-805-1035ND
2014-11-129590-806-11558.10 ppb
2014-11-129590-807-12057.80 ppb
2014-11-129590-808-12206.10 ppb
2015-02-109590-801-09153.60 ppb
2015-02-109590-802-09355.80 ppb
2015-02-109590-803-09556.80 ppb
2015-02-109590-804-10404.50 ppb
2015-02-109590-805-1100ND
2015-02-109590-806-11105.80 ppb
2015-02-109590-807-11202.20 ppb
2015-02-109590-808-1130ND
2015-05-129590-801-08303.80 ppb
2015-05-129590-802-08453.70 ppb
2015-05-129590-803-09004.90 ppb
2015-05-129590-804-1015ND
2015-05-129590-805-10455.60 ppb
2015-05-129590-806-11553.90 ppb
2015-05-129590-807-12104.00 ppb
2015-05-129590-808-12253.90 ppb
2015-08-119590-801-08203.20 ppb
2015-08-119590-802-08355.30 ppb
2015-08-119590-803-08505.00 ppb
2015-08-119590-804-08554.30 ppb
2015-08-119590-805-10455.80 ppb
2015-08-119590-806-11105.40 ppb
2015-08-119590-807-11204.70 ppb
2015-08-119590-808-11304.80 ppb
2015-11-109590-801-09052.10 ppb
2015-11-109590-802-08554.20 ppb
2015-11-109590-803-08404.00 ppb
2015-11-109590-804-09202.20 ppb
2015-11-109590-805-09402.20 ppb
2015-11-109590-806-0820ND
2015-11-109590-807-0810ND
2015-11-109590-808-0755ND
2016-02-099590-801-0935ND
2016-02-099590-802-0920ND
2016-02-099590-803-0905ND
2016-02-099590-804-0950ND
2016-02-099590-805-0845ND
2016-02-099590-806-0805ND
2016-02-099590-807-0820ND
2016-02-099590-808-0750ND
2016-05-109590-801-08103.70 ppb
2016-05-109590-802-08254.40 ppb
2016-05-109590-803-07554.10 ppb
2016-05-109590-804-07405.10 ppb
2016-05-109590-805-0845ND
2016-05-109590-806-09055.00 ppb
2016-05-109590-807-09154.90 ppb
2016-05-109590-808-09303.60 ppb
2016-08-099590-801-09402.80 ppb
2016-08-099590-802-09304.80 ppb
2016-08-099590-803-09155.10 ppb
2016-08-099590-804-09057.40 ppb
2016-08-099590-805-0845ND
2016-08-099590-806-08304.30 ppb
2016-08-099590-807-08154.60 ppb
2016-08-099590-808-0800ND
2016-11-089590-801-07303.80 ppb
2016-11-089590-802-07454.00 ppb
2016-11-089590-803-07553.80 ppb
2016-11-089590-804-08053.60 ppb
2016-11-089590-805-08202.00 ppb
2016-11-089590-806-08357.20 ppb
2016-11-089590-807-08457.50 ppb
2016-11-089590-808-08555.30 ppb
2017-02-149590-801-10454.70 ppb
2017-02-149590-802-10304.50 ppb
2017-02-149590-803-10054.60 ppb
2017-02-149590-804-10153.10 ppb
2017-02-149590-805-0910ND
2017-02-149590-806-0930ND
2017-02-149590-807-0945ND
2017-02-149590-808-0955ND
2017-05-089590-801-08455.00 ppb
2017-05-089590-802-10304.30 ppb
2017-05-089590-803-10155.30 ppb
2017-05-089590-804-10004.30 ppb
2017-05-089590-805-1100ND
2017-05-089590-806-11153.20 ppb
2017-05-089590-807-10454.00 ppb
2017-05-089590-808-11002.60 ppb
2017-08-089590-801-08309.60 ppb
2017-08-089590-802-08355.50 ppb
2017-08-089590-803-08458.00 ppb
2017-08-089590-804-09256.60 ppb
2017-08-089590-805-10407.90 ppb
2017-08-089590-806-11008.50 ppb
2017-08-089590-807-11158.40 ppb
2017-08-089590-808-11259.60 ppb
2017-11-149590-801-10305.30 ppb
2017-11-149590-802-10155.30 ppb
2017-11-149590-803-09455.20 ppb
2017-11-149590-804-10004.30 ppb
2017-11-149590-805-09305.70 ppb
2017-11-149590-806-08455.50 ppb
2017-11-149590-807-08305.80 ppb
2017-11-149590-808-08155.20 ppb
2018-02-139590-801-08104.50 ppb
2018-02-139590-802-08254.20 ppb
2018-02-139590-803-08354.10 ppb
2018-02-139590-804-08504.10 ppb
2018-02-139590-805-0905ND
2018-02-139590-806-09207.00 ppb
2018-02-139590-807-09306.30 ppb
2018-02-139590-808-09455.50 ppb
2018-05-089590-801-11054.80 ppb
2018-05-089590-802-10505.60 ppb
2018-05-089590-803-10405.50 ppb
2018-05-089590-804-10304.90 ppb
2018-05-089590-805-08202.00 ppb
2018-05-089590-806-0805ND
2018-05-089590-807-07552.00 ppb
2018-05-089590-808-0740ND
2018-08-149588-801-08005.00 ppb
2018-08-149588-802-08104.90 ppb
2018-08-149588-803-08203.70 ppb
2018-08-149588-804-08303.70 ppb
2018-08-149588-805-08404.70 ppb
2018-08-149588-806-08504.50 ppb
2018-08-149588-807-0900ND
2018-08-149588-808-0910ND
2018-11-149588-801-08103.00 ppb
2018-11-149588-802-08253.10 ppb
2018-11-149588-803-08451.000 ppb
2018-11-149588-804-0905ND
2018-11-149588-805-09202.90 ppb
2018-11-149588-806-09352.90 ppb
2018-11-149588-807-09453.50 ppb
2018-11-149588-808-10002.90 ppb
2019-02-129588-801-09452.00 ppb
2019-02-129588-802-10005.90 ppb
2019-02-129588-803-10106.00 ppb
2019-02-129588-804-1020ND
2019-02-129588-805-10301.40 ppb
2019-02-129588-806-1045ND
2019-02-129588-807-1055ND
2019-02-129588-808-1110ND
2019-05-079588-801-08306.50 ppb
2019-05-079588-802-08456.20 ppb
2019-05-079588-803-08556.20 ppb
2019-05-079588-804-09104.50 ppb
2019-05-079588-805-0920ND
2019-05-079588-806-09306.80 ppb
2019-05-079588-807-09407.70 ppb
2019-05-079588-808-09506.80 ppb
2019-08-139588-801-08307.60 ppb
2019-08-139588-802-08457.10 ppb
2019-08-139588-803-09006.90 ppb
2019-08-139588-804-09154.70 ppb
2019-08-139588-805-10452.20 ppb
2019-08-139588-806-1115ND
2019-08-139588-807-1125ND
2019-08-139588-808-1145ND
2019-11-139588-801-09056.50 ppb
2019-11-139588-802-09156.10 ppb
2019-11-139588-803-09256.50 ppb
2019-11-139588-804-09355.90 ppb
2019-11-139588-805-09054.70 ppb
2019-11-139588-806-09405.00 ppb
2019-11-139588-807-09505.10 ppb
2019-11-139588-808-10104.80 ppb