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EWG's Tap Water Database — 2019 UPDATE

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Chloroform

City of Corona

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.

 

339

Samples

0

Samples exceeding legal limit (MCL)

156

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20123.06 ppb6134ND - 13.0 ppb
20132.17 ppb7131ND - 17.0 ppb
20141.91 ppb6025ND - 12.0 ppb
20151.72 ppb5521ND - 11.0 ppb
20162.42 ppb4215ND - 14.0 ppb
20173.59 ppb5030ND - 16.0 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
2012-03-124790-019-13456.20 ppb
2012-03-124790-036-14002.10 ppb
2012-03-124790-041-1445ND
2012-03-124790-043-11002.80 ppb
2012-03-124790-049-10252.30 ppb
2012-06-044790-019-09409.50 ppb
2012-06-044790-036-13257.80 ppb
2012-06-044790-041-1300ND
2012-06-044790-801-100011.0 ppb
2012-06-044790-802-1140ND
2012-06-044790-803-153013.0 ppb
2012-06-044790-804-143012.0 ppb
2012-06-044790-805-14102.50 ppb
2012-06-044790-806-111011.0 ppb
2012-06-044790-807-13255.70 ppb
2012-06-044790-808-11059.70 ppb
2012-06-134790-003-1145ND
2012-06-134790-013-1115ND
2012-06-134790-022-1030ND
2012-06-134790-023-1230ND
2012-06-134790-030-1200ND
2012-06-134790-033-1300ND
2012-06-204790-014-1550ND
2012-06-204790-015-1450ND
2012-06-204790-027-0930ND
2012-06-204790-032-1035ND
2012-06-204790-038-1310ND
2012-06-214790-019-09506.00 ppb
2012-06-214790-034-1300ND
2012-06-214790-043-12209.30 ppb
2012-06-214790-052-1040ND
2012-06-224790-039-0730ND
2012-06-274790-024-0930ND
2012-06-274790-029-1400ND
2012-06-274790-031-1450ND
2012-06-274790-054-1120ND
2012-06-274790-056-10301.20 ppb
2012-06-274790-062-1020ND
2012-09-114790-019-10504.70 ppb
2012-09-114790-036-11554.70 ppb
2012-09-114790-041-1150ND
2012-09-114790-801-105011.0 ppb
2012-09-114790-802-1135ND
2012-09-114790-803-08255.50 ppb
2012-09-114790-804-08556.60 ppb
2012-09-114790-805-08003.80 ppb
2012-09-114790-806-11157.90 ppb
2012-09-114790-807-13301.50 ppb
2012-09-114790-808-10354.60 ppb
2012-12-044790-055-0900ND
2012-12-104790-019-10502.80 ppb
2012-12-104790-036-12002.70 ppb
2012-12-104790-041-1145ND
2012-12-104790-801-09107.40 ppb
2012-12-104790-802-1100ND
2012-12-104790-803-10100.810 ppb
2012-12-104790-804-09001.40 ppb
2012-12-104790-805-09402.70 ppb
2012-12-104790-806-10452.20 ppb
2012-12-104790-807-11301.20 ppb
2012-12-104790-808-14002.90 ppb
2013-02-064790-021-0930ND
2013-02-064790-027-1330ND
2013-02-064790-030-1130ND
2013-02-064790-039-1130ND
2013-02-134790-052-1510ND
2013-02-134790-054-1350ND
2013-02-134790-062-1440ND
2013-03-114790-019-0830ND
2013-03-114790-036-13450.570 ppb
2013-03-114790-041-1450ND
2013-03-114790-801-11207.80 ppb
2013-03-114790-802-13051.60 ppb
2013-03-114790-803-1615ND
2013-03-114790-804-1520ND
2013-03-114790-805-1625ND
2013-03-114790-806-12506.00 ppb
2013-03-114790-807-11202.90 ppb
2013-03-114790-808-09251.30 ppb
2013-05-014790-024-1230ND
2013-05-014790-038-1050ND
2013-05-084790-003-1440ND
2013-05-084790-022-1400ND
2013-05-084790-023-0910ND
2013-05-164790-019-13405.10 ppb
2013-05-164790-034-0915ND
2013-05-164790-043-10507.70 ppb
2013-06-104790-019-15105.80 ppb
2013-06-104790-036-13454.60 ppb
2013-06-104790-041-0920ND
2013-06-104790-801-111517.0 ppb
2013-06-104790-802-12102.10 ppb
2013-06-104790-803-11304.40 ppb
2013-06-104790-804-10305.50 ppb
2013-06-104790-805-1150ND
2013-06-104790-806-11456.60 ppb
2013-06-104790-807-12402.10 ppb
2013-06-104790-808-12205.80 ppb
2013-06-124790-055-1135ND
2013-06-264790-028-0900ND
2013-08-079590-032-0940ND
2013-08-159590-033-0900ND
2013-08-159590-056-1435ND
2013-08-219590-029-1002ND
2013-08-229590-013-0940ND
2013-08-229590-014-1500ND
2013-08-229590-015-1402ND
2013-08-229590-031-0825ND
2013-09-049590-055-1115ND
2013-09-099590-019-13457.20 ppb
2013-09-099590-036-13254.40 ppb
2013-09-099590-041-1410ND
2013-09-099590-801-123011.0 ppb
2013-09-099590-802-13451.10 ppb
2013-09-099590-803-17104.40 ppb
2013-09-099590-804-16504.80 ppb
2013-09-099590-805-17302.10 ppb
2013-09-099590-806-14506.00 ppb
2013-09-099590-807-09042.00 ppb
2013-09-099590-808-10274.00 ppb
2013-12-109590-055-0845ND
2013-12-169590-019-1430ND
2013-12-169590-036-1300ND
2013-12-169590-041-1330ND
2013-12-169590-801-10406.20 ppb
2013-12-169590-802-1150ND
2013-12-169590-803-1400ND
2013-12-169590-804-1450ND
2013-12-169590-805-1430ND
2013-12-169590-806-11305.00 ppb
2013-12-169590-807-09001.20 ppb
2013-12-169590-808-09457.70 ppb
2014-02-129590-021-0900ND
2014-02-129590-027-1020ND
2014-02-129590-028-1450ND
2014-02-129590-039-1100ND
2014-02-129590-052-1145ND
2014-02-129590-054-13551.50 ppb
2014-02-269590-030-0730ND
2014-03-039590-019-1345ND
2014-03-039590-036-14301.70 ppb
2014-03-039590-041-1505ND
2014-03-039590-801-131511.0 ppb
2014-03-039590-802-1510ND
2014-03-039590-803-1229ND
2014-03-039590-804-1026ND
2014-03-039590-805-1305ND
2014-03-039590-806-14351.90 ppb
2014-03-039590-807-08551.70 ppb
2014-03-039590-808-1135ND
2014-03-129590-055-1120ND
2014-05-149590-024-1325ND
2014-05-149590-038-1035ND
2014-05-149590-043-09157.30 ppb
2014-05-159590-019-11555.50 ppb
2014-05-159590-022-0850ND
2014-05-159590-023-1005ND
2014-05-159590-034-1500ND
2014-06-029590-801-12008.90 ppb
2014-06-029590-802-10452.60 ppb
2014-06-029590-803-08253.80 ppb
2014-06-029590-804-08503.90 ppb
2014-06-029590-805-09202.00 ppb
2014-06-029590-806-12304.90 ppb
2014-06-029590-807-09501.20 ppb
2014-06-029590-808-10205.30 ppb
2014-08-139590-015-0930ND
2014-08-139590-031-1455ND
2014-08-139590-032-1100ND
2014-08-139590-033-1315ND
2014-08-219590-029-0900ND
2014-08-269590-003-1400ND
2014-08-279590-014-1315ND
2014-08-279590-056-1415ND
2014-08-289590-013-1030ND
2014-09-159590-801-130012.0 ppb
2014-09-159590-802-14004.10 ppb
2014-09-159590-803-08154.60 ppb
2014-09-159590-804-09105.20 ppb
2014-09-159590-805-09352.10 ppb
2014-09-159590-806-13307.40 ppb
2014-09-159590-807-10102.20 ppb
2014-09-159590-808-11305.20 ppb
2014-09-169590-054-1500ND
2014-12-159590-801-14207.10 ppb
2014-12-159590-802-1340ND
2014-12-159590-803-0850ND
2014-12-159590-804-0920ND
2014-12-159590-805-0950ND
2014-12-159590-807-10201.60 ppb
2014-12-159590-808-1135ND
2014-12-159590-809-1040ND
2015-02-039590-030-10001.40 ppb
2015-02-129590-027-0900ND
2015-02-129590-028-1420ND
2015-02-129590-030-0810ND
2015-02-129590-039-0950ND
2015-02-129590-052-13301.60 ppb
2015-03-099590-801-12506.40 ppb
2015-03-099590-802-12301.80 ppb
2015-03-099590-803-0900ND
2015-03-099590-804-0935ND
2015-03-099590-805-1015ND
2015-03-099590-807-1040ND
2015-03-099590-808-1320ND
2015-03-099590-809-1110ND
2015-05-289590-003-0940ND
2015-05-289590-019-10455.40 ppb
2015-05-289590-024-0930ND
2015-05-289590-034-0830ND
2015-05-289590-038-1000ND
2015-05-289590-043-11008.70 ppb
2015-06-089590-801-14509.20 ppb
2015-06-089590-802-14202.00 ppb
2015-06-089590-803-09003.60 ppb
2015-06-089590-804-09403.20 ppb
2015-06-089590-805-1010ND
2015-06-089590-807-10402.20 ppb
2015-06-089590-808-13406.30 ppb
2015-06-089590-809-11002.60 ppb
2015-06-099590-062-0815ND
2015-08-129590-029-0900ND
2015-08-129590-031-1020ND
2015-08-129590-032-1100ND
2015-08-129590-056-0940ND
2015-08-209590-013-0900ND
2015-08-209590-014-1430ND
2015-08-209590-015-1130ND
2015-08-209590-033-0950ND
2015-09-179590-801-112011.0 ppb
2015-09-179590-802-1100ND
2015-09-179590-803-08151.30 ppb
2015-09-179590-804-0840ND
2015-09-179590-805-09002.30 ppb
2015-09-179590-807-09101.60 ppb
2015-09-179590-808-10404.80 ppb
2015-09-179590-809-10206.70 ppb
2015-10-149590-023-0930ND
2015-10-149590-054-13303.00 ppb
2015-12-239590-801-10159.50 ppb
2015-12-239590-802-1130ND
2015-12-239590-803-0910ND
2015-12-239590-804-0945ND
2015-12-239590-805-0930ND
2015-12-239590-807-1510ND
2015-12-239590-808-1420ND
2015-12-239590-809-1440ND
2016-03-099590-801-10255.40 ppb
2016-03-099590-802-1050ND
2016-03-099590-803-1110ND
2016-03-099590-804-0840ND
2016-03-099590-805-0910ND
2016-03-099590-807-1330ND
2016-03-099590-808-1440ND
2016-03-099590-809-1400ND
2016-04-139590-027-0950ND
2016-04-139590-028-0800ND
2016-04-139590-030-0850ND
2016-04-219590-054-1340ND
2016-04-279590-062-1320ND
2016-06-099590-801-11518.60 ppb
2016-06-099590-802-1045ND
2016-06-099590-803-08275.30 ppb
2016-06-099590-804-08525.40 ppb
2016-06-099590-805-09105.70 ppb
2016-06-099590-807-09363.20 ppb
2016-06-099590-808-10287.30 ppb
2016-06-099590-809-10063.70 ppb
2016-07-209590-039-1045ND
2016-08-189590-003-1000ND
2016-08-189590-023-1050ND
2016-08-189590-038-1400ND
2016-08-239590-024-1430ND
2016-08-249590-019-10306.80 ppb
2016-08-249590-034-0900ND
2016-08-249590-043-14308.80 ppb
2016-09-139590-802-13501.10 ppb
2016-09-139590-808-145013.0 ppb
2016-09-139590-809-144014.0 ppb
2016-10-119590-031-1530ND
2016-10-129590-032-1430ND
2016-10-209590-029-1400ND
2016-10-279590-014-0915ND
2016-10-279590-015-1020ND
2016-10-279590-033-1400ND
2016-10-279590-056-0840ND
2016-12-159590-802-1350ND
2016-12-159590-808-10106.50 ppb
2016-12-159590-809-09506.70 ppb
2017-03-169590-801-09006.60 ppb
2017-03-169590-802-0950ND
2017-03-169590-803-11203.80 ppb
2017-03-169590-804-10303.40 ppb
2017-03-169590-805-1100ND
2017-03-169590-807-152015.0 ppb
2017-03-169590-808-142016.0 ppb
2017-03-169590-809-144016.0 ppb
2017-04-129590-030-1000ND
2017-04-129590-054-1400ND
2017-04-129590-062-1500ND
2017-04-209590-027-1400ND
2017-04-209590-038-0920ND
2017-04-209590-039-1500ND
2017-06-159590-801-11204.60 ppb
2017-06-159590-802-1540ND
2017-06-159590-803-09203.40 ppb
2017-06-159590-804-09453.90 ppb
2017-06-159590-805-10102.90 ppb
2017-06-159590-807-13404.60 ppb
2017-06-159590-808-14304.60 ppb
2017-06-159590-809-14004.70 ppb
2017-08-099590-019-10305.30 ppb
2017-08-099590-023-0945ND
2017-08-099590-024-1400ND
2017-08-099590-043-15305.10 ppb
2017-08-109590-034-1220ND
2017-09-139590-801-110011.0 ppb
2017-09-139590-802-14003.10 ppb
2017-09-139590-803-08506.30 ppb
2017-09-139590-804-09108.50 ppb
2017-09-139590-805-09306.80 ppb
2017-09-139590-807-10006.20 ppb
2017-09-139590-808-14407.40 ppb
2017-09-139590-809-15206.10 ppb
2017-10-129590-015-1500ND
2017-10-129590-031-0930ND
2017-10-129590-032-1030ND
2017-10-199590-014-1030ND
2017-10-199590-029-1500ND
2017-10-199590-056-1400ND
2017-10-269590-033-1000ND
2017-12-149590-801-13506.40 ppb
2017-12-149590-802-1450ND
2017-12-149590-803-08302.30 ppb
2017-12-149590-804-08551.80 ppb
2017-12-149590-805-09252.50 ppb
2017-12-149590-807-09453.00 ppb
2017-12-149590-808-10204.20 ppb
2017-12-149590-809-10103.80 ppb