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EWG's Tap Water Database — 2021 UPDATE

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Haloacetic acids (HAA5)

City of Nampa

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

 

100

Samples

0

Samples exceeding legal limit (MCL)

33

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND160ND
2015ND160ND
20160.676 ppb166ND - 3.14 ppb
20170.968 ppb167ND - 6.08 ppb
20180.629 ppb168ND - 1.65 ppb
20191.18 ppb2012ND - 2.97 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
2014-02-20D1406359ND
2014-02-20D1406358ND
2014-02-20D1406357ND
2014-02-20D1406356ND
2014-05-14D1417170ND
2014-05-14D1417171ND
2014-05-14D1417172ND
2014-05-14D1417173ND
2014-08-19D1432332ND
2014-08-19D1432333ND
2014-08-19D1432334ND
2014-08-19D1432335ND
2014-11-18D1445847ND
2014-11-18D1445850ND
2014-11-18D1445849ND
2014-11-18D1445848ND
2015-02-24D1507119ND
2015-02-24D1507120ND
2015-02-24D1507121ND
2015-02-24D1507122ND
2015-06-09D1522388ND
2015-06-09D1522387ND
2015-06-09D1522389ND
2015-06-09D1522390ND
2015-09-01D1537283ND
2015-09-01D1537286ND
2015-09-01D1537285ND
2015-09-01D1537284ND
2015-11-18D1550142ND
2015-11-18D1550143ND
2015-11-18D1550144ND
2015-11-18D1550145ND
2016-02-16D1606316ND
2016-02-16D1606317ND
2016-02-16D1606318ND
2016-02-16D1606319ND
2016-04-20D1616218ND
2016-04-20D16162201.25 ppb
2016-04-20D16162191.30 ppb
2016-04-20D1616217ND
2016-07-14D1631271ND
2016-07-14D16312722.72 ppb
2016-07-14D1631273ND
2016-07-14D16312743.14 ppb
2016-10-07D16461781.11 ppb
2016-10-07D16461791.29 ppb
2016-10-07D1646176ND
2016-10-07D1646177ND
2017-01-31D1703808ND
2017-01-31D1703807ND
2017-01-31D1703809ND
2017-01-31D1703810ND
2017-04-11D1714417ND
2017-04-11D1714418ND
2017-04-11D17144191.82 ppb
2017-04-11D1714420ND
2017-08-09D1735771ND
2017-08-09D17357721.34 ppb
2017-08-09D17357731.77 ppb
2017-08-09D17357746.08 ppb
2017-10-18D17487611.04 ppb
2017-10-18D1748759ND
2017-10-18D17487601.51 ppb
2017-10-18D17487621.92 ppb
2018-01-10D1801343ND
2018-01-10D18013441.65 ppb
2018-01-10D18013451.13 ppb
2018-01-10D18013461.27 ppb
2018-05-02D1819575ND
2018-05-02D1819576ND
2018-05-02D18195771.08 ppb
2018-05-02D18195781.17 ppb
2018-08-13D18394941.17 ppb
2018-08-13D1839491ND
2018-08-13D18394931.56 ppb
2018-08-13D18394921.03 ppb
2018-10-08D1850033ND
2018-10-08D1850032ND
2018-10-08D1850031ND
2018-10-08D1850034ND
2019-01-30D19043391.13 ppb
2019-01-30D19043381.31 ppb
2019-01-30D1904337ND
2019-01-30D1904336ND
2019-05-08D19211982.97 ppb
2019-05-08D19211961.23 ppb
2019-05-08D1921195ND
2019-05-08D19211972.64 ppb
2019-07-18D1935124ND
2019-07-18D1935123ND
2019-07-18D19351222.83 ppb
2019-07-18D1935121ND
2019-09-18D19470141.71 ppb
2019-09-18D19470132.72 ppb
2019-09-18D19470122.25 ppb
2019-09-18D1947011ND
2019-12-31D19645741.77 ppb
2019-12-31D1964575ND
2019-12-31D19645761.000 ppb
2019-12-31D19645732.04 ppb