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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Los Angeles County WW District 4 & 34-Lancaster

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

 

216

Samples

0

Samples exceeding legal limit (MCL)

88

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
20140.751 ppb5827ND - 7.99 ppb
20151.14 ppb5628ND - 5.24 ppb
20162.40 ppb5320ND - 21.2 ppb
20172.95 ppb1913ND - 8.90 ppb
2018ND40ND
2019ND260ND

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
2014-01-105442-800-1126ND
2014-01-105442-801-10120.610 ppb
2014-01-105442-802-10270.510 ppb
2014-01-105442-803-09560.890 ppb
2014-01-105442-804-09250.770 ppb
2014-01-105442-805-08440.910 ppb
2014-01-105442-806-11020.530 ppb
2014-01-105442-807-09080.710 ppb
2014-03-185442-011-0830ND
2014-04-085442-802-12450.580 ppb
2014-04-085442-803-10050.520 ppb
2014-04-085442-804-09151.40 ppb
2014-04-085442-805-08301.90 ppb
2014-04-085442-807-09051.20 ppb
2014-04-095442-093-1000ND
2014-04-095442-800-09501.50 ppb
2014-04-095442-801-0910ND
2014-04-095442-806-0930ND
2014-06-175442-069-0900ND
2014-06-175442-070-0912ND
2014-07-075442-800-09001.09 ppb
2014-07-075442-806-08352.26 ppb
2014-07-085442-048-0902ND
2014-07-085442-062-0856ND
2014-07-085442-801-10407.99 ppb
2014-07-085442-802-12072.12 ppb
2014-07-085442-803-09301.97 ppb
2014-07-085442-804-08452.23 ppb
2014-07-085442-805-08004.94 ppb
2014-07-085442-807-08351.78 ppb
2014-07-095442-041-0907ND
2014-07-095442-045-1024ND
2014-07-105442-071-1100ND
2014-07-105442-094-1000ND
2014-07-105442-095-1007ND
2014-07-175442-067-1026ND
2014-07-225442-002-1150ND
2014-07-225442-036-0904ND
2014-07-225442-040-0855ND
2014-07-225442-053-1120ND
2014-07-225442-054-1135ND
2014-07-225442-055-0947ND
2014-07-245442-063-1110ND
2014-08-195442-035-1015ND
2014-08-265442-037-0845ND
2014-09-095442-016-1100ND
2014-09-095442-023-1100ND
2014-09-305442-026-0855ND
2014-09-305442-028-0940ND
2014-10-065442-800-13180.770 ppb
2014-10-065442-806-0830ND
2014-10-075442-801-1044ND
2014-10-075442-802-11560.530 ppb
2014-10-075442-803-09400.810 ppb
2014-10-075442-804-08591.67 ppb
2014-10-075442-805-08201.97 ppb
2014-10-075442-807-08501.38 ppb
2014-10-085442-806-1339ND
2015-01-125442-800-13050.930 ppb
2015-01-125442-806-13311.21 ppb
2015-01-135442-801-1050ND
2015-01-135442-802-1230ND
2015-01-135442-803-0950ND
2015-01-135442-804-09100.900 ppb
2015-01-135442-805-08301.19 ppb
2015-01-135442-807-09100.720 ppb
2015-03-045442-011-1020ND
2015-04-075442-093-0918ND
2015-04-085442-800-10203.02 ppb
2015-04-085442-801-11122.76 ppb
2015-04-085442-802-1056ND
2015-04-085442-803-11300.650 ppb
2015-04-085442-804-11433.28 ppb
2015-04-085442-805-13071.55 ppb
2015-04-085442-806-10453.66 ppb
2015-04-085442-807-11513.37 ppb
2015-04-145442-068-1110ND
2015-06-025442-069-1100ND
2015-06-025442-070-1010ND
2015-07-065442-028-1150ND
2015-07-065442-048-1115ND
2015-07-065442-062-1120ND
2015-07-075442-026-0850ND
2015-07-075442-041-0828ND
2015-07-075442-045-0938ND
2015-07-075442-802-12301.26 ppb
2015-07-075442-803-10002.64 ppb
2015-07-075442-804-09453.20 ppb
2015-07-075442-805-14405.24 ppb
2015-07-075442-807-13302.56 ppb
2015-07-085442-067-0922ND
2015-07-085442-071-1100ND
2015-07-085442-095-1145ND
2015-07-085442-806-12302.38 ppb
2015-07-135442-040-0850ND
2015-07-145442-053-0945ND
2015-07-145442-054-0930ND
2015-07-155442-800-11401.72 ppb
2015-07-155442-801-08442.03 ppb
2015-07-275442-055-1155ND
2015-08-125442-035-0925ND
2015-08-125442-036-0910ND
2015-08-185442-037-0930ND
2015-09-215442-016-0856ND
2015-09-215442-023-0905ND
2015-10-075442-800-13101.72 ppb
2015-10-075442-802-12380.670 ppb
2015-10-075442-803-09173.34 ppb
2015-10-075442-804-09073.51 ppb
2015-10-075442-805-08282.95 ppb
2015-10-075442-806-13252.70 ppb
2015-10-075442-807-08502.74 ppb
2015-11-125442-801-10301.90 ppb
2015-12-165442-094-1015ND
2016-01-115442-800-1235ND
2016-01-115442-806-1257ND
2016-01-135442-801-1053ND
2016-01-135442-802-1119ND
2016-01-135442-803-1034ND
2016-01-135442-804-09220.830 ppb
2016-01-135442-805-08210.840 ppb
2016-01-135442-807-09040.760 ppb
2016-01-195442-035-0950ND
2016-01-195442-040-0945ND
2016-01-255442-028-0840ND
2016-01-255442-048-0940ND
2016-01-255442-062-0930ND
2016-01-265442-093-1100ND
2016-02-095442-069-1010ND
2016-02-095442-070-1110ND
2016-02-105442-071-1125ND
2016-03-095442-023-1041ND
2016-03-285442-011-1138ND
2016-03-285442-055-1126ND
2016-03-285442-067-0856ND
2016-04-145442-800-100510.3 ppb
2016-04-145442-801-11037.42 ppb
2016-04-145442-802-10454.67 ppb
2016-04-145442-803-11183.58 ppb
2016-04-145442-804-113510.9 ppb
2016-04-145442-805-12072.59 ppb
2016-04-145442-806-102314.3 ppb
2016-04-145442-807-11469.15 ppb
2016-04-205442-026-1016ND
2016-04-205442-041-0934ND
2016-06-085442-036-0945ND
2016-06-275442-094-1125ND
2016-06-275442-095-1050ND
2016-06-285442-037-1132ND
2016-06-285442-053-1155ND
2016-06-285442-054-1152ND
2016-07-155442-800-10562.10 ppb
2016-07-155442-801-09581.87 ppb
2016-07-155442-802-101810.9 ppb
2016-07-155442-803-09364.45 ppb
2016-07-155442-804-091621.2 ppb
2016-07-155442-805-084212.9 ppb
2016-07-155442-806-11154.13 ppb
2016-07-155442-807-09013.05 ppb
2016-08-315442-016-1105ND
2016-10-135442-802-1243ND
2016-10-135442-804-12031.22 ppb
2016-10-145442-800-1036ND
2016-10-145442-801-0905ND
2016-10-145442-802-0936ND
2016-10-145442-806-1011ND
2016-12-155442-045-0911ND
2017-01-115442-802-1112ND
2017-01-115442-803-1056ND
2017-01-125442-804-10511.09 ppb
2017-01-125442-805-10201.54 ppb
2017-01-125442-806-1115ND
2017-01-125442-807-10381.40 ppb
2017-01-255442-800-12453.62 ppb
2017-01-255442-801-10204.13 ppb
2017-07-109588-800-08023.60 ppb
2017-07-109588-801-09043.10 ppb
2017-07-109588-802-08332.70 ppb
2017-07-109588-803-09497.50 ppb
2017-07-109588-804-10127.30 ppb
2017-07-109588-805-10158.90 ppb
2017-07-109588-806-11124.60 ppb
2017-07-109588-807-09266.50 ppb
2017-07-189588-063-0950ND
2017-11-219590-045-0935ND
2017-12-272920-068-0935ND
2018-02-289590-037-1000ND
2018-02-289590-053-1035ND
2018-02-289590-054-1030ND
2018-12-269590-063-1055ND
2019-01-079590-093-1706ND
2019-01-089590-023-1115ND
2019-01-089590-026-1025ND
2019-01-089590-045-1020ND
2019-02-069590-067-1100ND
2019-02-119590-070-1125ND
2019-02-119590-071-1120ND
2019-02-199590-011-1145ND
2019-02-269590-028-1150ND
2019-02-269590-048-1225ND
2019-02-269590-062-1210ND
2019-02-269590-063-1210ND
2019-03-139590-036-1035ND
2019-03-139590-094-0920ND
2019-03-139590-095-0925ND
2019-03-139590-095-0940ND
2019-03-199590-035-1120ND
2019-03-199590-040-1145ND
2019-03-199590-041-0930ND
2019-03-199590-053-1315ND
2019-03-199590-054-1300ND
2019-03-269590-069-0945ND
2019-06-199590-037-1000ND
2019-08-129590-055-1040ND
2019-08-199590-023-1020ND
2019-12-239590-095-0933ND