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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Manville WSC

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

 

138

Samples

0

Samples exceeding legal limit (MCL)

115

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
20145.32 ppb2017ND - 28.3 ppb
20155.45 ppb2622ND - 28.0 ppb
20163.03 ppb2319ND - 12.9 ppb
20174.23 ppb2316ND - 21.1 ppb
20185.84 ppb2322ND - 25.6 ppb
20198.36 ppb2319ND - 21.3 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
2014-03-11AC46497ND
2014-03-11AC464621.90 ppb
2014-03-11AC464632.30 ppb
2014-03-11AC464612.40 ppb
2014-03-11AC464645.70 ppb
2014-06-18AC573026.90 ppb
2014-06-18AC5735810.1 ppb
2014-06-18AC5735728.3 ppb
2014-06-18AC573597.50 ppb
2014-06-18AC57356ND
2014-06-18AC572982.30 ppb
2014-06-18AC57300ND
2014-09-12AC668023.40 ppb
2014-09-12AC668044.10 ppb
2014-09-12AC668053.10 ppb
2014-09-12AC668032.80 ppb
2014-11-24AC727415.00 ppb
2014-11-24AC727758.20 ppb
2014-11-24AC727715.90 ppb
2014-11-24AC727726.40 ppb
2015-03-19AC853571.70 ppb
2015-03-19AC8536728.0 ppb
2015-03-19AC85369ND
2015-03-19AC853511.90 ppb
2015-03-19AC853651.80 ppb
2015-03-19AC852654.10 ppb
2015-03-19AC852855.60 ppb
2015-03-19AC852634.90 ppb
2015-03-19AC852676.00 ppb
2015-05-26AC933104.00 ppb
2015-05-26AC93308ND
2015-05-26AC933121.50 ppb
2015-05-26AC932562.00 ppb
2015-05-26AC932612.60 ppb
2015-05-26AC932541.80 ppb
2015-05-26AC932572.20 ppb
2015-08-17AD042615.60 ppb
2015-08-17AD04262ND
2015-08-17AD042652.30 ppb
2015-08-17AD04258ND
2015-09-29AD0900926.0 ppb
2015-11-18AD139973.30 ppb
2015-11-18AD1399111.8 ppb
2015-11-18AD139941.000 ppb
2015-11-18AD139953.70 ppb
2015-11-18AD1402720.0 ppb
2016-02-08AD224192.60 ppb
2016-02-08AD223991.000 ppb
2016-02-08AD224202.20 ppb
2016-02-08AD224182.10 ppb
2016-04-25AD34017ND
2016-04-25AD340199.10 ppb
2016-04-25AD340151.90 ppb
2016-04-25AD340133.30 ppb
2016-04-25AD34021ND
2016-04-25AD340232.30 ppb
2016-04-25AD339481.70 ppb
2016-04-25AD339491.10 ppb
2016-04-25AD339451.40 ppb
2016-04-25AD339441.20 ppb
2016-07-25AD454142.90 ppb
2016-07-25AD45411ND
2016-07-25AD454204.00 ppb
2016-07-25AD454164.70 ppb
2016-11-09AD57440ND
2016-11-09AD573688.60 ppb
2016-11-09AD5736712.9 ppb
2016-11-09AD573552.90 ppb
2016-11-09AD573643.70 ppb
2017-01-23AD660921.90 ppb
2017-01-23AD66090ND
2017-01-23AD660942.40 ppb
2017-01-23AD660313.90 ppb
2017-01-23AD660333.00 ppb
2017-01-23AD660353.20 ppb
2017-01-23AD660323.70 ppb
2017-04-27AD81512ND
2017-04-27AD8151413.0 ppb
2017-04-27AD81518ND
2017-04-27AD81516ND
2017-04-27AD815016.20 ppb
2017-04-27AD814981.90 ppb
2017-04-27AD815002.00 ppb
2017-04-27AD815025.70 ppb
2017-08-17AD933861.000 ppb
2017-08-17AD93390ND
2017-08-17AD93388ND
2017-08-17AD93389ND
2017-10-27AE0239821.1 ppb
2017-10-27AE0240517.5 ppb
2017-10-27AE024046.90 ppb
2017-10-27AE024063.80 ppb
2018-02-01AE118891.30 ppb
2018-02-01AE118935.70 ppb
2018-02-01AE118871.20 ppb
2018-02-01AE118811.000 ppb
2018-02-01AE118955.60 ppb
2018-02-01AE11885ND
2018-02-01AE118832.20 ppb
2018-02-01AE118263.00 ppb
2018-02-01AE118242.70 ppb
2018-02-01AE118232.60 ppb
2018-02-01AE118252.80 ppb
2018-04-04AE211854.20 ppb
2018-04-04AE211884.80 ppb
2018-04-04AE211874.60 ppb
2018-04-04AE211956.00 ppb
2018-08-27AE387462.60 ppb
2018-09-24AE412694.60 ppb
2018-09-24AE412714.00 ppb
2018-09-24AE412664.40 ppb
2018-11-09AE4573425.6 ppb
2018-11-09AE4573519.5 ppb
2018-11-27AE4699016.2 ppb
2018-11-27AE469849.80 ppb
2019-02-06AE531864.00 ppb
2019-02-06AE53180ND
2019-02-06AE53182ND
2019-02-06AE531841.80 ppb
2019-02-06AE531881.10 ppb
2019-02-06AE531186.10 ppb
2019-02-06AE531172.40 ppb
2019-02-06AE531194.20 ppb
2019-02-06AE531163.10 ppb
2019-06-06AE694209.30 ppb
2019-06-06AE6942212.5 ppb
2019-06-06AE694188.80 ppb
2019-06-06AE6941911.0 ppb
2019-09-12AE83244ND
2019-09-12AE8319015.6 ppb
2019-09-12AE8318821.3 ppb
2019-09-12AE8318916.4 ppb
2019-09-12AE8318716.8 ppb
2019-09-30AE85125ND
2019-12-03AE9098513.0 ppb
2019-12-03AE9098614.4 ppb
2019-12-03AE9098214.5 ppb
2019-12-03AE9098315.9 ppb