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EWG's Tap Water Database — 2021 UPDATE

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Haloacetic acids (HAA5)

San Lorenzo Valley 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

 

121

Samples

0

Samples exceeding legal limit (MCL)

99

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20146.53 ppb2016ND - 19.0 ppb
201512.3 ppb2016ND - 43.0 ppb
201617.7 ppb2018ND - 38.0 ppb
201715.1 ppb2015ND - 41.0 ppb
201811.2 ppb2117ND - 28.0 ppb
201920.5 ppb2017ND - 47.0 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 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
2014-01-175810-805-083013.0 ppb
2014-02-129590-801-09008.20 ppb
2014-02-129590-802-09158.60 ppb
2014-02-129590-803-1445ND
2014-02-129590-804-09456.10 ppb
2014-04-305810-805-12387.50 ppb
2014-05-209590-801-095012.0 ppb
2014-05-209590-802-101519.0 ppb
2014-05-209590-803-1110ND
2014-05-209590-804-103513.0 ppb
2014-07-305810-805-10123.60 ppb
2014-08-139590-801-10004.00 ppb
2014-08-139590-802-10207.00 ppb
2014-08-139590-803-1400ND
2014-08-139590-804-09003.90 ppb
2014-10-295810-805-10493.00 ppb
2014-11-129590-801-12004.20 ppb
2014-11-129590-802-12308.90 ppb
2014-11-129590-803-1430ND
2014-11-129590-804-12458.50 ppb
2015-01-275810-805-11453.90 ppb
2015-02-119590-801-152043.0 ppb
2015-02-119590-802-145536.0 ppb
2015-02-119590-803-143032.0 ppb
2015-02-119590-804-142028.0 ppb
2015-04-275810-805-07502.20 ppb
2015-05-209590-801-155023.0 ppb
2015-05-209590-802-153021.0 ppb
2015-05-209590-803-1450ND
2015-05-209590-804-150018.0 ppb
2015-07-075810-805-1213ND
2015-08-129590-801-13454.90 ppb
2015-08-129590-802-13157.00 ppb
2015-08-129590-803-1100ND
2015-08-129590-804-12007.80 ppb
2015-10-145810-805-11152.70 ppb
2015-11-179590-801-11003.80 ppb
2015-11-179590-802-11305.80 ppb
2015-11-179590-803-1430ND
2015-11-179590-804-12007.20 ppb
2016-01-145810-805-10235.20 ppb
2016-02-109590-801-150034.0 ppb
2016-02-109590-802-144027.0 ppb
2016-02-109590-803-140023.0 ppb
2016-02-109590-804-153038.0 ppb
2016-04-215810-805-093921.0 ppb
2016-05-119590-801-130013.0 ppb
2016-05-119590-802-123016.0 ppb
2016-05-119590-803-11307.70 ppb
2016-05-119590-804-120012.0 ppb
2016-08-119590-801-105013.0 ppb
2016-08-119590-802-103013.0 ppb
2016-08-119590-803-1150ND
2016-08-119590-804-112516.0 ppb
2016-08-259590-805-1220ND
2016-11-039590-805-11503.10 ppb
2016-11-059590-801-113035.0 ppb
2016-11-059590-802-110032.0 ppb
2016-11-059590-803-124521.0 ppb
2016-11-059590-804-113024.0 ppb
2017-02-159590-801-094541.0 ppb
2017-02-159590-802-110027.0 ppb
2017-02-159590-803-10504.60 ppb
2017-02-159590-804-114037.0 ppb
2017-03-089590-805-122013.0 ppb
2017-05-119590-801-131517.0 ppb
2017-05-119590-802-124519.0 ppb
2017-05-119590-804-123022.0 ppb
2017-05-119590-805-113021.0 ppb
2017-05-319590-803-1030ND
2017-08-179590-801-094520.0 ppb
2017-08-179590-802-104517.0 ppb
2017-08-179590-803-1130ND
2017-08-179590-804-101520.0 ppb
2017-08-179590-805-1010ND
2017-11-079590-801-120011.0 ppb
2017-11-079590-802-113016.0 ppb
2017-11-079590-803-1040ND
2017-11-079590-804-111017.0 ppb
2017-11-079590-805-0945ND
2018-02-159590-801-093015.0 ppb
2018-02-159590-802-103027.0 ppb
2018-02-159590-803-1230ND
2018-02-159590-804-100028.0 ppb
2018-02-159590-805-09204.90 ppb
2018-05-179590-801-103024.0 ppb
2018-05-179590-802-100019.0 ppb
2018-05-179590-803-090015.0 ppb
2018-05-179590-804-093015.0 ppb
2018-05-179590-805-103016.0 ppb
2018-08-159590-801-091513.0 ppb
2018-08-159590-802-09007.20 ppb
2018-08-159590-802-1115ND
2018-08-159590-803-1030ND
2018-08-159590-804-094518.0 ppb
2018-08-159590-805-10453.10 ppb
2018-11-159590-801-10307.00 ppb
2018-11-159590-802-11009.60 ppb
2018-11-159590-803-1230ND
2018-11-159590-804-10009.90 ppb
2018-11-159590-805-13003.70 ppb
2019-02-219590-801-094027.0 ppb
2019-02-219590-802-090543.0 ppb
2019-02-219590-803-094031.0 ppb
2019-02-219590-804-083047.0 ppb
2019-02-219590-805-090036.0 ppb
2019-05-159590-801-104522.0 ppb
2019-05-159590-802-110527.0 ppb
2019-05-159590-803-133520.0 ppb
2019-05-159590-804-121519.0 ppb
2019-05-159590-805-131025.0 ppb
2019-08-149590-801-120026.0 ppb
2019-08-149590-802-113020.0 ppb
2019-08-149590-803-1445ND
2019-08-149590-804-110023.0 ppb
2019-08-149590-805-1400ND
2019-11-199590-801-104012.0 ppb
2019-11-199590-802-101514.0 ppb
2019-11-199590-803-0830ND
2019-11-199590-804-094515.0 ppb
2019-11-199590-805-09103.30 ppb