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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Woodstock

Chloroform, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Chloroform and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Read More.

In addition to tap water disinfection, chloroform pollution in the environment also comes from industrial discharges from pulp and paper mills, and from urban wastewater effluent. Human studies show that chloroform damages the kidneys, liver and central nervous system. In animals, chloroform causes infertility, birth defects and cancer.

Click here to read more about disinfection byproducts.

MORE ABOUT THIS CONTAMINANT

 

121

Samples

0

Samples exceeding legal limit (MCL)

116

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
201425.9 ppb161611.0 ppb - 40.0 ppb
201537.2 ppb161623.0 ppb - 79.0 ppb
201629.9 ppb161612.0 ppb - 56.0 ppb
201735.5 ppb161615.0 ppb - 57.0 ppb
20189.15 ppb3128ND - 38.0 ppb
201913.4 ppb2624ND - 36.0 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.4 ppb

The EWG Health Guideline of 0.4 ppb for chloroform was proposed in 2018 by the California Office of Environmental Health Hazard Assessment as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.

ppb = parts per billion

All test results

Date Lab ID Result
2014-01-13AI2627226.0 ppb
2014-01-13AI2627325.0 ppb
2014-01-13AI2627411.0 ppb
2014-01-13AI2627525.0 ppb
2014-04-08AI3726823.0 ppb
2014-04-08AI3726920.0 ppb
2014-04-08AI3727017.0 ppb
2014-04-08AI3727116.0 ppb
2014-07-10AI4542339.0 ppb
2014-07-10AI4542428.0 ppb
2014-07-10AI4542529.0 ppb
2014-07-10AI4542626.0 ppb
2014-10-06AI5667334.0 ppb
2014-10-06AI5667428.0 ppb
2014-10-06AI5667540.0 ppb
2014-10-06AI5667628.0 ppb
2015-01-22AI6325226.0 ppb
2015-01-22AI6325323.0 ppb
2015-01-22AI6325431.0 ppb
2015-01-22AI6325579.0 ppb
2015-04-09AI7450035.0 ppb
2015-04-09AI7450136.0 ppb
2015-04-09AI7450234.0 ppb
2015-04-09AI7450325.0 ppb
2015-07-08AI8207436.0 ppb
2015-07-08AI8207536.0 ppb
2015-07-08AI8207643.0 ppb
2015-07-08AI8207739.0 ppb
2015-10-26AI9975050.0 ppb
2015-10-26AI9975123.0 ppb
2015-10-26AI9975235.0 ppb
2015-10-26AI9975344.0 ppb
2016-01-12AJ0394418.0 ppb
2016-01-12AJ0394512.0 ppb
2016-01-12AJ0394621.0 ppb
2016-01-12AJ0394726.0 ppb
2016-04-12AJ0984128.0 ppb
2016-04-12AJ0984220.0 ppb
2016-04-12AJ0984329.0 ppb
2016-04-12AJ0984420.0 ppb
2016-07-12AJ1712540.0 ppb
2016-07-12AJ1712638.0 ppb
2016-07-12AJ1712736.0 ppb
2016-07-12AJ1712856.0 ppb
2016-10-10AJ3099534.0 ppb
2016-10-10AJ3099630.0 ppb
2016-10-10AJ3099731.0 ppb
2016-10-10AJ3099839.0 ppb
2017-01-11AJ3791121.0 ppb
2017-01-11AJ3791216.0 ppb
2017-01-11AJ3791323.0 ppb
2017-01-11AJ3791415.0 ppb
2017-04-10AJ5284237.0 ppb
2017-04-10AJ5284324.0 ppb
2017-04-10AJ5284429.0 ppb
2017-04-10AJ5284553.0 ppb
2017-07-12AJ5996956.0 ppb
2017-07-12AJ5997052.0 ppb
2017-07-12AJ5997157.0 ppb
2017-07-12AJ5997251.0 ppb
2017-10-12AJ7153833.0 ppb
2017-10-12AJ7153935.0 ppb
2017-10-12AJ7154033.0 ppb
2017-10-12AJ7154133.0 ppb
2018-01-09AJ761906.50 ppb
2018-01-09AJ7619110.00 ppb
2018-01-09AJ761929.80 ppb
2018-01-09AJ761935.20 ppb
2018-04-09AJ8698712.0 ppb
2018-04-09AJ8698818.0 ppb
2018-04-09AJ8698924.0 ppb
2018-04-09AJ8699010.00 ppb
2018-04-10AJ870863.60 ppb
2018-04-10AJ870871.30 ppb
2018-04-10AJ87088ND
2018-04-10AJ870890.800 ppb
2018-04-10AJ870900.910 ppb
2018-07-09AJ9320222.0 ppb
2018-07-09AJ9320326.0 ppb
2018-07-09AJ9320438.0 ppb
2018-07-09AJ9320519.0 ppb
2018-07-10AJ934423.90 ppb
2018-07-10AJ934431.50 ppb
2018-07-10AJ93444ND
2018-07-10AJ934450.970 ppb
2018-07-10AJ934460.800 ppb
2018-12-18AK083293.00 ppb
2018-12-18AK083300.830 ppb
2018-12-18AK083310.840 ppb
2018-12-18AK083321.70 ppb
2018-12-18AK08333ND
2018-12-18AK0833911.0 ppb
2018-12-18AK0834019.0 ppb
2018-12-18AK0834120.0 ppb
2018-12-18AK0834213.0 ppb
2019-01-08AK0902311.0 ppb
2019-01-08AK0902418.0 ppb
2019-01-08AK0902524.0 ppb
2019-01-08AK090269.30 ppb
2019-01-08AK090272.80 ppb
2019-01-08AK090281.30 ppb
2019-01-08AK09029ND
2019-01-08AK090300.960 ppb
2019-01-08AK090310.760 ppb
2019-04-08AK1470115.0 ppb
2019-04-08AK1470214.0 ppb
2019-04-08AK1470324.0 ppb
2019-04-08AK147047.50 ppb
2019-04-15AK151693.20 ppb
2019-04-15AK151701.40 ppb
2019-04-15AK15171ND
2019-04-15AK151721.20 ppb
2019-04-15AK151730.820 ppb
2019-07-10AK2186324.0 ppb
2019-07-10AK2186429.0 ppb
2019-07-10AK2186536.0 ppb
2019-07-10AK2186631.0 ppb
2019-10-08AK3448020.0 ppb
2019-10-08AK3448122.0 ppb
2019-10-08AK3448234.0 ppb
2019-10-08AK3448317.0 ppb