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EWG's Tap Water Database — 2019 UPDATE

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Haloacetic acids (HAA5)

Los Angeles County Waterworks District 36-Val Verde

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.

 

30

Samples

0

Samples exceeding legal limit (MCL)

3

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012N/A00N/A
2013ND20ND
2014ND80ND
20150.508 ppb82ND - 2.47 ppb
20160.251 ppb81ND - 2.01 ppb
2017ND40ND

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
2013-10-095442-801-1244ND
2013-10-095442-800-1031ND
2014-01-085442-801-0944ND
2014-01-085442-800-1210ND
2014-04-085442-800-1330ND
2014-04-105442-801-0845ND
2014-07-085442-801-0825ND
2014-07-085442-800-0930ND
2014-10-065442-801-0950ND
2014-10-065442-800-1040ND
2015-01-145442-800-0915ND
2015-01-145442-801-1012ND
2015-04-095442-800-0831ND
2015-04-095442-801-0908ND
2015-07-085442-800-09452.47 ppb
2015-07-085442-801-08301.59 ppb
2015-10-065442-800-0930ND
2015-10-065442-801-0820ND
2016-01-135442-801-0925ND
2016-01-135442-800-1015ND
2016-04-115442-801-1030ND
2016-04-115442-800-11252.01 ppb
2016-07-125442-801-1215ND
2016-07-125442-800-1305ND
2016-10-135442-801-1050ND
2016-10-135442-800-1145ND
2017-01-105442-801-1154ND
2017-01-105442-800-1220ND
2017-07-109588-801-0950ND
2017-07-109588-800-0900ND