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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Military Highway WSC - Las Rusias WTP

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

 

94

Samples

0

Samples exceeding legal limit (MCL)

67

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20145.81 ppb992.10 ppb - 11.7 ppb
20151.95 ppb118ND - 6.20 ppb
20162.09 ppb1817ND - 4.70 ppb
20171.55 ppb2012ND - 5.70 ppb
20185.42 ppb1812ND - 34.9 ppb
20192.19 ppb189ND - 6.80 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
2014-03-19AC477223.10 ppb
2014-03-19AC477112.90 ppb
2014-06-03AC558835.00 ppb
2014-06-03AC558735.70 ppb
2014-09-23AC678505.20 ppb
2014-09-23AC678897.10 ppb
2014-09-23AC679312.10 ppb
2014-10-22AC7032211.7 ppb
2014-10-22AC703209.50 ppb
2015-03-12AC840696.20 ppb
2015-03-12AC840673.00 ppb
2015-05-07AC909632.60 ppb
2015-05-07AC909672.10 ppb
2015-08-04AD022912.60 ppb
2015-08-04AD02300ND
2015-08-04AD023592.00 ppb
2015-11-17AD137951.10 ppb
2015-11-17AD13797ND
2015-11-17AD138001.90 ppb
2015-11-17AD13794ND
2016-03-03AD268752.20 ppb
2016-03-03AD268741.80 ppb
2016-03-03AD268731.50 ppb
2016-03-03AD268701.50 ppb
2016-06-09AD399951.90 ppb
2016-06-09AD399912.00 ppb
2016-06-09AD399963.60 ppb
2016-06-09AD399402.10 ppb
2016-08-04AD471522.20 ppb
2016-08-04AD470841.10 ppb
2016-08-04AD470782.90 ppb
2016-08-04AD47040ND
2016-08-04AD470831.30 ppb
2016-10-26AD548672.70 ppb
2016-10-26AD547962.20 ppb
2016-10-26AD547911.60 ppb
2016-10-26AD547874.70 ppb
2016-10-26AD547882.30 ppb
2017-02-28AD724161.70 ppb
2017-02-28AD72407ND
2017-02-28AD724095.70 ppb
2017-02-28AD72411ND
2017-02-28AD72506ND
2017-05-02AD821564.30 ppb
2017-05-02AD821571.20 ppb
2017-05-02AD821531.80 ppb
2017-05-02AD821581.10 ppb
2017-05-02AD822181.30 ppb
2017-08-15AD930221.90 ppb
2017-08-15AD93000ND
2017-08-15AD930043.80 ppb
2017-08-15AD93001ND
2017-08-15AD931101.50 ppb
2017-08-15AD93124ND
2017-10-04AD99256ND
2017-10-04AD992785.40 ppb
2017-10-04AD99252ND
2017-10-04AD992671.20 ppb
2018-02-14AE137381.20 ppb
2018-02-14AE13739ND
2018-02-14AE137441.70 ppb
2018-02-14AE13740ND
2018-02-14AE13782ND
2018-05-16AE2655719.8 ppb
2018-05-16AE265615.90 ppb
2018-05-16AE2656234.9 ppb
2018-06-12AE29460ND
2018-08-14AE368606.70 ppb
2018-08-14AE369452.70 ppb
2018-08-14AE368545.20 ppb
2018-08-14AE368555.40 ppb
2018-08-14AE368564.60 ppb
2018-10-11AE432398.00 ppb
2018-10-11AE43240ND
2018-10-11AE432381.40 ppb
2018-10-11AE43242ND
2019-02-28AE565023.00 ppb
2019-02-28AE56505ND
2019-02-28AE565002.90 ppb
2019-02-28AE56504ND
2019-06-05AE69220ND
2019-06-05AE69205ND
2019-06-05AE692026.80 ppb
2019-06-05AE692196.10 ppb
2019-08-21AE798105.20 ppb
2019-08-21AE79829ND
2019-08-21AE798083.50 ppb
2019-08-21AE79831ND
2019-08-21AE798802.00 ppb
2019-08-21AE79876ND
2019-11-06AE88645ND
2019-11-06AE886445.60 ppb
2019-11-06AE88641ND
2019-11-06AE886434.40 ppb