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EWG's Tap Water Database — 2021 UPDATE

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Haloacetic acids (HAA5)

U.S. Navy San Clemente Island

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.

 

340

Samples

2

Samples exceeding legal limit (MCL)

291

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
201413.2 ppb6049ND - 28.0 ppb
201512.6 ppb6047ND - 26.0 ppb
201618.9 ppb4540ND - 46.0 ppb
201728.6 ppb5552ND - 80.0 ppb
201815.4 ppb6051ND - 32.0 ppb
201917.5 ppb6052ND - 43.0 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
2014-01-229590-900-101020.0 ppb
2014-01-229590-901-064512.0 ppb
2014-01-229590-902-082522.0 ppb
2014-01-229590-903-073024.0 ppb
2014-01-229590-904-0925ND
2014-02-129590-900-091520.0 ppb
2014-02-129590-901-08554.00 ppb
2014-02-129590-902-101023.0 ppb
2014-02-129590-903-094021.0 ppb
2014-02-129590-904-0820ND
2014-03-129590-900-112014.0 ppb
2014-03-129590-901-09553.10 ppb
2014-03-129590-902-110015.0 ppb
2014-03-129590-903-103018.0 ppb
2014-03-129590-904-0930ND
2014-04-089590-900-15058.90 ppb
2014-04-089590-901-14459.80 ppb
2014-04-089590-902-160518.0 ppb
2014-04-089590-903-153013.0 ppb
2014-04-099590-904-11103.80 ppb
2014-05-149590-900-100016.0 ppb
2014-05-149590-901-065514.0 ppb
2014-05-149590-902-102021.0 ppb
2014-05-149590-903-074022.0 ppb
2014-05-149590-904-08452.30 ppb
2014-06-119590-900-070019.0 ppb
2014-06-119590-901-062022.0 ppb
2014-06-119590-902-094520.0 ppb
2014-06-119590-903-090520.0 ppb
2014-06-119590-904-0745ND
2014-07-159590-900-151516.0 ppb
2014-07-159590-901-074018.0 ppb
2014-07-159590-902-143524.0 ppb
2014-07-159590-903-115028.0 ppb
2014-07-169590-904-1045ND
2014-08-129590-900-151018.0 ppb
2014-08-129590-901-154011.0 ppb
2014-08-129590-902-145020.0 ppb
2014-08-129590-903-141522.0 ppb
2014-08-139590-904-0945ND
2014-09-089590-900-100018.0 ppb
2014-09-089590-901-102511.0 ppb
2014-09-089590-902-084020.0 ppb
2014-09-089590-903-092022.0 ppb
2014-09-109590-904-0950ND
2014-10-219590-900-132016.0 ppb
2014-10-219590-901-13507.80 ppb
2014-10-219590-902-101516.0 ppb
2014-10-219590-903-124518.0 ppb
2014-10-229590-904-1010ND
2014-11-139590-900-100513.0 ppb
2014-11-139590-901-0905ND
2014-11-139590-902-114518.0 ppb
2014-11-139590-903-124015.0 ppb
2014-11-139590-904-0935ND
2014-12-169590-900-095512.0 ppb
2014-12-169590-901-083011.0 ppb
2014-12-169590-902-094018.0 ppb
2014-12-169590-903-091014.0 ppb
2014-12-179590-904-1010ND
2015-01-279590-900-095511.0 ppb
2015-01-279590-901-094016.0 ppb
2015-01-279590-902-083014.0 ppb
2015-01-279590-903-075017.0 ppb
2015-01-289590-904-0745ND
2015-02-109590-900-105012.0 ppb
2015-02-109590-901-091013.0 ppb
2015-02-109590-902-08308.90 ppb
2015-02-109590-903-08108.90 ppb
2015-02-119590-904-0845ND
2015-03-109590-900-095512.0 ppb
2015-03-109590-901-101514.0 ppb
2015-03-109590-902-110515.0 ppb
2015-03-109590-903-104515.0 ppb
2015-03-109590-904-093512.0 ppb
2015-04-139590-900-074517.0 ppb
2015-04-139590-901-081015.0 ppb
2015-04-139590-902-070018.0 ppb
2015-04-139590-903-062018.0 ppb
2015-04-139590-904-09302.80 ppb
2015-05-199590-900-105018.0 ppb
2015-05-199590-901-103518.0 ppb
2015-05-199590-902-101017.0 ppb
2015-05-199590-903-094018.0 ppb
2015-05-209590-904-115016.0 ppb
2015-06-099590-900-165515.0 ppb
2015-06-099590-901-164012.0 ppb
2015-06-099590-902-162018.0 ppb
2015-06-099590-903-154518.0 ppb
2015-06-109590-904-12302.40 ppb
2015-07-089590-900-1318ND
2015-07-089590-901-1300ND
2015-07-089590-902-123517.0 ppb
2015-07-089590-903-121120.0 ppb
2015-07-089590-904-1248ND
2015-08-059590-900-114617.0 ppb
2015-08-059590-901-120317.0 ppb
2015-08-059590-902-112821.0 ppb
2015-08-059590-903-105422.0 ppb
2015-08-059590-904-1935ND
2015-09-169590-900-131022.0 ppb
2015-09-169590-901-1337ND
2015-09-169590-902-124822.0 ppb
2015-09-169590-903-121524.0 ppb
2015-09-169590-904-1346ND
2015-10-149590-900-102022.0 ppb
2015-10-149590-901-0945ND
2015-10-149590-902-104026.0 ppb
2015-10-149590-903-112023.0 ppb
2015-10-149590-904-0925ND
2015-11-189590-900-112016.0 ppb
2015-11-189590-901-1104ND
2015-11-189590-902-114019.0 ppb
2015-11-189590-903-120719.0 ppb
2015-11-189590-904-1055ND
2015-12-169590-900-11409.60 ppb
2015-12-169590-901-111210.00 ppb
2015-12-169590-902-120016.0 ppb
2015-12-169590-903-123019.0 ppb
2015-12-169590-904-1530ND
2016-01-139590-900-110015.0 ppb
2016-01-139590-901-104216.0 ppb
2016-01-139590-902-112017.0 ppb
2016-01-139590-903-115519.0 ppb
2016-01-149590-904-0900ND
2016-02-049590-902-163016.0 ppb
2016-02-049590-903-130016.0 ppb
2016-02-059590-900-094013.0 ppb
2016-02-059590-901-10108.20 ppb
2016-02-109590-904-0900ND
2016-03-059590-900-151515.0 ppb
2016-03-059590-901-164514.0 ppb
2016-03-059590-902-143016.0 ppb
2016-03-059590-903-092018.0 ppb
2016-03-109590-904-09002.10 ppb
2016-04-019590-900-125019.0 ppb
2016-04-019590-901-143016.0 ppb
2016-04-019590-902-122024.0 ppb
2016-04-019590-903-111521.0 ppb
2016-04-079590-904-1015ND
2016-05-119590-904-1125ND
2016-05-129590-900-153514.0 ppb
2016-05-129590-901-15558.70 ppb
2016-05-129590-902-145014.0 ppb
2016-05-129590-903-124019.0 ppb
2016-07-059590-900-084019.0 ppb
2016-07-059590-901-100517.0 ppb
2016-07-059590-902-082023.0 ppb
2016-07-059590-903-092020.0 ppb
2016-07-069590-904-0915ND
2016-08-229590-900-101024.0 ppb
2016-08-229590-901-103520.0 ppb
2016-08-229590-902-095528.0 ppb
2016-08-229590-903-090028.0 ppb
2016-08-249590-904-09105.60 ppb
2016-10-239590-900-092024.0 ppb
2016-10-239590-901-103034.0 ppb
2016-10-239590-902-075733.0 ppb
2016-10-239590-903-100031.0 ppb
2016-10-269590-904-09304.80 ppb
2016-11-089590-900-082642.0 ppb
2016-11-089590-901-080043.0 ppb
2016-11-089590-902-072144.0 ppb
2016-11-089590-903-070546.0 ppb
2016-11-099590-904-090542.0 ppb
2017-01-169590-900-074534.0 ppb
2017-01-169590-901-093527.0 ppb
2017-01-169590-902-071034.0 ppb
2017-01-169590-903-100534.0 ppb
2017-01-189590-904-1030ND
2017-02-049590-900-131014.0 ppb
2017-02-049590-901-121515.0 ppb
2017-02-049590-902-141524.0 ppb
2017-02-049590-903-150027.0 ppb
2017-02-089590-904-0845ND
2017-03-059590-900-143517.0 ppb
2017-03-059590-901-155014.0 ppb
2017-03-059590-902-120021.0 ppb
2017-03-059590-903-150022.0 ppb
2017-03-089590-904-08055.10 ppb
2017-04-029590-900-151037.0 ppb
2017-04-029590-902-143038.0 ppb
2017-04-039590-903-161038.0 ppb
2017-04-049590-901-114540.0 ppb
2017-04-059590-904-07456.50 ppb
2017-05-089590-900-131563.0 ppb
2017-05-089590-901-110059.0 ppb
2017-05-089590-902-102059.0 ppb
2017-05-089590-903-093059.0 ppb
2017-05-109590-904-083059.0 ppb
2017-07-039590-900-080154.0 ppb
2017-07-039590-901-121720.0 ppb
2017-07-039590-902-114118.0 ppb
2017-07-039590-903-111051.0 ppb
2017-07-069590-904-091080.0 ppb
2017-08-079590-900-130039.0 ppb
2017-08-079590-901-111538.0 ppb
2017-08-079590-902-133037.0 ppb
2017-08-079590-903-141038.0 ppb
2017-08-099590-904-090030.0 ppb
2017-09-049590-900-113527.0 ppb
2017-09-049590-901-115026.0 ppb
2017-09-049590-902-111629.0 ppb
2017-09-049590-903-100030.0 ppb
2017-09-069590-904-074024.0 ppb
2017-10-019590-900-100522.0 ppb
2017-10-019590-901-102020.0 ppb
2017-10-019590-902-094024.0 ppb
2017-10-019590-903-085028.0 ppb
2017-10-039590-904-091028.0 ppb
2017-11-039590-902-113526.0 ppb
2017-11-039590-903-104526.0 ppb
2017-11-049590-900-134522.0 ppb
2017-11-049590-901-141021.0 ppb
2017-11-089590-904-1030ND
2017-12-019590-900-101517.0 ppb
2017-12-019590-901-14453.20 ppb
2017-12-019590-902-130021.0 ppb
2017-12-019590-903-110022.0 ppb
2017-12-069590-904-08053.10 ppb
2018-01-089590-900-095515.0 ppb
2018-01-089590-901-101513.0 ppb
2018-01-089590-902-093523.0 ppb
2018-01-089590-903-072023.0 ppb
2018-01-119590-904-0930ND
2018-02-045810-900-092022.0 ppb
2018-02-045810-901-091022.0 ppb
2018-02-045810-902-083022.0 ppb
2018-02-045810-903-080024.0 ppb
2018-02-065810-904-08102.40 ppb
2018-03-065810-900-093520.0 ppb
2018-03-065810-901-075522.0 ppb
2018-03-065810-902-091023.0 ppb
2018-03-065810-903-083527.0 ppb
2018-03-065810-904-08023.90 ppb
2018-04-025810-900-093028.0 ppb
2018-04-025810-901-085029.0 ppb
2018-04-025810-902-081529.0 ppb
2018-04-025810-903-074030.0 ppb
2018-04-045810-904-090030.0 ppb
2018-05-035810-900-123026.0 ppb
2018-05-035810-901-15205.50 ppb
2018-05-035810-902-144032.0 ppb
2018-05-035810-903-135531.0 ppb
2018-05-095810-904-08102.60 ppb
2018-06-035810-900-110013.0 ppb
2018-06-035810-901-101016.0 ppb
2018-06-035810-902-112024.0 ppb
2018-06-035810-903-093025.0 ppb
2018-06-065810-904-0810ND
2018-07-095810-900-163014.0 ppb
2018-07-095810-901-164513.0 ppb
2018-07-095810-902-155020.0 ppb
2018-07-095810-903-151520.0 ppb
2018-07-095810-904-09003.40 ppb
2018-08-085810-900-073013.0 ppb
2018-08-085810-901-0850ND
2018-08-085810-902-075024.0 ppb
2018-08-085810-903-085022.0 ppb
2018-08-085810-904-0900ND
2018-09-045810-900-094011.0 ppb
2018-09-045810-901-10053.30 ppb
2018-09-045810-902-091019.0 ppb
2018-09-045810-903-084524.0 ppb
2018-09-055810-904-0730ND
2018-10-025810-900-08457.50 ppb
2018-10-025810-901-0915ND
2018-10-025810-902-082020.0 ppb
2018-10-025810-903-072517.0 ppb
2018-10-035810-904-0730ND
2018-11-055810-900-161016.0 ppb
2018-11-055810-901-155016.0 ppb
2018-11-055810-902-153024.0 ppb
2018-11-055810-903-145522.0 ppb
2018-11-055810-904-0710ND
2018-12-015810-900-09557.00 ppb
2018-12-015810-903-140013.0 ppb
2018-12-015810-904-0930ND
2018-12-135810-901-09202.70 ppb
2018-12-135810-902-09059.30 ppb
2019-01-025810-900-15158.50 ppb
2019-01-025810-902-145512.0 ppb
2019-01-025810-903-1415ND
2019-01-035810-901-0655ND
2019-01-035810-904-0730ND
2019-02-125810-900-08555.90 ppb
2019-02-125810-901-09105.80 ppb
2019-02-125810-902-083012.0 ppb
2019-02-125810-903-071510.00 ppb
2019-02-275810-904-1230ND
2019-03-055810-900-07156.20 ppb
2019-03-055810-901-07356.10 ppb
2019-03-055810-902-065514.0 ppb
2019-03-055810-903-062512.0 ppb
2019-03-065810-904-0715ND
2019-04-085810-900-083013.0 ppb
2019-04-085810-901-07306.00 ppb
2019-04-085810-902-071516.0 ppb
2019-04-085810-903-075514.0 ppb
2019-04-115810-904-07257.90 ppb
2019-05-145810-900-081537.0 ppb
2019-05-145810-901-084532.0 ppb
2019-05-145810-902-075528.0 ppb
2019-05-145810-903-071528.0 ppb
2019-05-155810-904-07202.20 ppb
2019-06-035810-900-101532.0 ppb
2019-06-035810-901-130014.0 ppb
2019-06-035810-902-103040.0 ppb
2019-06-035810-903-110043.0 ppb
2019-06-055810-904-12303.40 ppb
2019-07-015810-900-141032.0 ppb
2019-07-015810-901-143031.0 ppb
2019-07-015810-902-134537.0 ppb
2019-07-015810-903-131528.0 ppb
2019-07-025810-904-08058.10 ppb
2019-08-055810-903-163540.0 ppb
2019-08-065810-900-142519.0 ppb
2019-08-065810-901-151017.0 ppb
2019-08-065810-902-123027.0 ppb
2019-08-075810-904-0715ND
2019-09-105810-900-135517.0 ppb
2019-09-105810-901-14157.60 ppb
2019-09-105810-902-130025.0 ppb
2019-09-105810-903-132728.0 ppb
2019-09-105810-904-0830ND
2019-10-085810-900-105517.0 ppb
2019-10-085810-901-10255.80 ppb
2019-10-085810-902-103517.0 ppb
2019-10-085810-903-101018.0 ppb
2019-10-085810-904-09254.70 ppb
2019-11-045810-900-095028.0 ppb
2019-11-045810-901-110025.0 ppb
2019-11-045810-902-101033.0 ppb
2019-11-045810-903-103531.0 ppb
2019-11-045810-904-0745ND
2019-12-065810-903-100039.0 ppb
2019-12-075810-900-141042.0 ppb
2019-12-075810-902-114033.0 ppb
2019-12-105810-901-163524.0 ppb
2019-12-115810-904-08106.40 ppb