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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

City of San Jacinto

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

 

67

Samples

0

Samples exceeding legal limit (MCL)

51

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
20149.22 ppb1512ND - 53.0 ppb
20151.41 ppb1210ND - 6.00 ppb
20160.300 ppb82ND - 1.30 ppb
2017N/A00N/A
20185.89 ppb1615ND - 35.0 ppb
20192.11 ppb1612ND - 5.70 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
2014-03-124790-009-08492.80 ppb
2014-03-184790-804-14100.750 ppb
2014-03-184790-801-13392.40 ppb
2014-03-184790-803-13281.60 ppb
2014-03-184790-802-13101.20 ppb
2014-06-104790-804-0840ND
2014-06-104790-803-07500.590 ppb
2014-06-104790-801-0810ND
2014-06-104790-802-072549.0 ppb
2014-09-104790-804-1145ND
2014-09-104790-801-09451.40 ppb
2014-09-104790-802-081223.0 ppb
2014-09-104790-803-08521.80 ppb
2014-12-084790-801-14570.800 ppb
2014-12-084790-802-140753.0 ppb
2015-03-104790-803-14100.760 ppb
2015-03-104790-801-14300.580 ppb
2015-03-104790-804-1455ND
2015-03-104790-802-13303.80 ppb
2015-06-094790-802-15421.30 ppb
2015-06-094790-803-15050.640 ppb
2015-06-094790-804-14210.530 ppb
2015-06-094790-801-1342ND
2015-12-084790-804-15501.30 ppb
2015-12-084790-802-14036.00 ppb
2015-12-084790-803-15151.20 ppb
2015-12-084790-801-15300.830 ppb
2016-01-204790-014-0847ND
2016-01-274790-005-0840ND
2016-02-234790-001-1430ND
2016-03-024790-010-1420ND
2016-06-074790-802-08251.30 ppb
2016-06-074790-804-1021ND
2016-06-074790-803-09081.10 ppb
2016-06-074790-801-0944ND
2018-03-144790-803-07153.10 ppb
2018-03-144790-801-08003.00 ppb
2018-03-144790-802-09252.10 ppb
2018-03-144790-804-08422.30 ppb
2018-06-134790-803-09252.30 ppb
2018-06-134790-801-07002.30 ppb
2018-06-134790-802-09002.40 ppb
2018-06-134790-804-07402.40 ppb
2018-09-194790-803-095331.0 ppb
2018-09-194790-801-09342.30 ppb
2018-09-194790-802-082035.0 ppb
2018-09-194790-804-10272.30 ppb
2018-12-124790-801-07301.30 ppb
2018-12-124790-804-0835ND
2018-12-124790-802-10421.10 ppb
2018-12-124790-803-09431.30 ppb
2019-03-134790-804-09501.60 ppb
2019-03-134790-802-07151.60 ppb
2019-03-134790-801-09041.70 ppb
2019-03-134790-803-08001.70 ppb
2019-03-204790-010-0701ND
2019-03-274790-014-0701ND
2019-09-114790-802-07152.40 ppb
2019-09-114790-803-09203.00 ppb
2019-09-114790-801-08533.00 ppb
2019-09-114790-804-10013.30 ppb
2019-12-104790-010-1330ND
2019-12-114790-803-07303.50 ppb
2019-12-114790-801-08245.70 ppb
2019-12-114790-802-07003.40 ppb
2019-12-114790-804-10302.80 ppb
2019-12-114790-005-0900ND