Menu

EWG's Tap Water Database — 2021 UPDATE

Donate

Chloroform

City of Mendota

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

 

90

Samples

0

Samples exceeding legal limit (MCL)

4

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND40ND
2015ND190ND
2016ND160ND
2017ND160ND
2018ND190ND
20190.244 ppb164ND - 0.980 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
2014-12-305810-904-1056ND
2014-12-305810-903-1040ND
2014-12-305810-901-1115ND
2014-12-305810-902-1020ND
2015-02-175810-902-0903ND
2015-02-175810-901-0835ND
2015-02-175810-904-1017ND
2015-02-175810-903-0944ND
2015-04-015810-902-0956ND
2015-04-015810-901-1115ND
2015-04-015810-903-1020ND
2015-04-015810-904-1045ND
2015-07-145810-902-1015ND
2015-07-145810-903-1000ND
2015-07-145810-904-0919ND
2015-07-145810-901-1035ND
2015-10-205810-902-0840ND
2015-10-205810-903-0920ND
2015-10-205810-904-0900ND
2015-10-205810-901-0821ND
2015-11-245810-011-1030ND
2015-11-245810-010-0940ND
2015-11-245810-009-1140ND
2016-01-195810-903-0945ND
2016-01-195810-904-0930ND
2016-01-195810-901-0830ND
2016-01-195810-902-0855ND
2016-04-055810-903-1020ND
2016-04-055810-902-1145ND
2016-04-055810-904-1100ND
2016-04-055810-901-1115ND
2016-07-055810-902-0900ND
2016-07-055810-903-1230ND
2016-07-055810-904-1110ND
2016-07-055810-901-0825ND
2016-10-045810-902-1104ND
2016-10-045810-903-1140ND
2016-10-045810-904-1124ND
2016-10-045810-901-1158ND
2017-01-245810-901-1018ND
2017-01-245810-902-1040ND
2017-01-245810-903-1058ND
2017-01-245810-904-1120ND
2017-04-045810-904-0950ND
2017-04-045810-903-1015ND
2017-04-045810-901-1030ND
2017-04-045810-902-0916ND
2017-07-185810-904-1007ND
2017-07-185810-901-0912ND
2017-07-185810-902-0927ND
2017-07-185810-903-0945ND
2017-10-105810-904-1051ND
2017-10-105810-903-1120ND
2017-10-105810-901-1000ND
2017-10-105810-902-1030ND
2018-01-165810-901-1137ND
2018-01-165810-903-1114ND
2018-01-165810-904-1125ND
2018-01-165810-902-1103ND
2018-04-025810-901-1157ND
2018-04-025810-903-1226ND
2018-04-025810-904-1244ND
2018-04-025810-902-1213ND
2018-08-025806-903-1050ND
2018-08-025806-901-0815ND
2018-08-025806-902-1102ND
2018-08-025806-904-1037ND
2018-10-125806-904-1048ND
2018-10-125806-903-1011ND
2018-10-125806-901-0915ND
2018-10-125806-902-0930ND
2018-10-225806-009-1355ND
2018-10-225806-010-1345ND
2018-10-225806-011-1320ND
2019-01-095806-903-10100.960 ppb
2019-01-095806-901-09450.980 ppb
2019-01-095806-902-10000.980 ppb
2019-01-095806-904-10200.980 ppb
2019-04-045806-903-0847ND
2019-04-045806-902-0935ND
2019-04-045806-901-0922ND
2019-04-045806-904-0900ND
2019-07-015806-901-0940ND
2019-07-015806-904-1040ND
2019-07-015806-902-1020ND
2019-07-015806-903-1005ND
2019-10-215806-903-1057ND
2019-10-215806-904-1120ND
2019-10-215806-901-1030ND
2019-10-215806-902-1045ND