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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Calleguas Municipal Water District

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

 

330

Samples

0

Samples exceeding legal limit (MCL)

278

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20142.08 ppb5550ND - 5.10 ppb
20153.47 ppb5651ND - 6.80 ppb
20161.70 ppb5550ND - 8.90 ppb
20172.67 ppb5553ND - 15.7 ppb
20182.21 ppb5541ND - 14.0 ppb
20190.833 ppb5433ND - 3.40 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
2014-01-075867-025-13450.700 ppb
2014-01-075867-026-14450.800 ppb
2014-01-075867-027-0900ND
2014-01-075867-028-08000.700 ppb
2014-01-075867-029-12300.800 ppb
2014-01-075867-030-13150.600 ppb
2014-01-075867-031-13000.700 ppb
2014-01-075867-032-11400.600 ppb
2014-01-075867-033-10301.20 ppb
2014-01-075867-034-10500.800 ppb
2014-01-075867-035-1110ND
2014-01-075867-036-0940ND
2014-01-105867-006-0945ND
2014-01-105867-010-11302.50 ppb
2014-03-215867-007-11252.30 ppb
2014-04-085867-025-14002.70 ppb
2014-04-085867-026-14303.20 ppb
2014-04-085867-027-09052.30 ppb
2014-04-085867-028-08302.40 ppb
2014-04-085867-029-12302.60 ppb
2014-04-085867-030-13252.20 ppb
2014-04-085867-031-12502.50 ppb
2014-04-085867-032-11453.40 ppb
2014-04-085867-033-09402.60 ppb
2014-04-085867-034-10302.60 ppb
2014-04-085867-035-11152.80 ppb
2014-04-085867-036-10102.80 ppb
2014-04-115867-009-10103.00 ppb
2014-04-185867-011-10303.90 ppb
2014-05-075867-004-09152.30 ppb
2014-07-085867-025-13553.60 ppb
2014-07-085867-026-15013.00 ppb
2014-07-085867-027-08412.80 ppb
2014-07-085867-028-08103.00 ppb
2014-07-085867-029-12513.30 ppb
2014-07-085867-030-13313.00 ppb
2014-07-085867-031-13153.10 ppb
2014-07-085867-032-11443.90 ppb
2014-07-085867-033-09555.10 ppb
2014-07-085867-034-10263.90 ppb
2014-07-085867-035-11144.00 ppb
2014-07-085867-036-09134.20 ppb
2014-10-065867-025-11271.50 ppb
2014-10-065867-026-10301.30 ppb
2014-10-065867-027-08421.40 ppb
2014-10-065867-028-15001.40 ppb
2014-10-065867-029-12211.50 ppb
2014-10-065867-030-12081.50 ppb
2014-10-065867-031-12401.50 ppb
2014-10-065867-032-13101.60 ppb
2014-10-065867-033-14201.60 ppb
2014-10-065867-034-13521.80 ppb
2014-10-065867-035-13311.80 ppb
2014-10-065867-036-14401.50 ppb
2014-11-185867-008-1315ND
2015-01-065867-025-1018ND
2015-01-065867-026-09450.800 ppb
2015-01-065867-027-08304.30 ppb
2015-01-065867-028-08002.10 ppb
2015-01-065867-029-11431.10 ppb
2015-01-065867-030-10450.800 ppb
2015-01-065867-031-11050.700 ppb
2015-01-065867-032-12140.900 ppb
2015-01-065867-033-13500.700 ppb
2015-01-065867-034-13204.40 ppb
2015-01-065867-035-12570.900 ppb
2015-01-065867-036-14203.90 ppb
2015-02-025867-004-0815ND
2015-02-195867-017-14155.20 ppb
2015-02-265867-004-10451.10 ppb
2015-04-065867-025-13273.90 ppb
2015-04-065867-026-14033.70 ppb
2015-04-065867-027-08553.40 ppb
2015-04-065867-028-08104.30 ppb
2015-04-065867-029-12083.10 ppb
2015-04-065867-030-12433.60 ppb
2015-04-065867-031-12253.40 ppb
2015-04-065867-032-11303.50 ppb
2015-04-065867-033-10113.80 ppb
2015-04-065867-034-10354.20 ppb
2015-04-065867-035-10563.60 ppb
2015-04-065867-036-09255.50 ppb
2015-07-075867-025-13016.40 ppb
2015-07-075867-026-14193.70 ppb
2015-07-075867-028-08014.30 ppb
2015-07-075867-029-11544.90 ppb
2015-07-075867-030-12313.10 ppb
2015-07-075867-031-12154.50 ppb
2015-07-075867-032-11073.00 ppb
2015-07-075867-033-09305.90 ppb
2015-07-075867-034-10106.20 ppb
2015-07-075867-035-10352.80 ppb
2015-07-075867-036-09554.00 ppb
2015-10-125867-025-13334.50 ppb
2015-10-125867-026-14106.10 ppb
2015-10-125867-027-09003.10 ppb
2015-10-125867-028-08195.90 ppb
2015-10-125867-029-12024.50 ppb
2015-10-125867-030-12524.10 ppb
2015-10-125867-031-12344.50 ppb
2015-10-125867-032-11184.90 ppb
2015-10-125867-033-09546.70 ppb
2015-10-125867-034-10196.80 ppb
2015-10-125867-035-10516.60 ppb
2015-10-125867-036-09356.80 ppb
2015-10-215867-014-10202.60 ppb
2015-10-275867-012-1030ND
2015-10-275867-015-1300ND
2015-10-275867-016-1130ND
2015-11-045867-004-13402.60 ppb
2015-11-055867-013-11402.80 ppb
2016-01-115867-025-15092.20 ppb
2016-01-115867-026-15361.70 ppb
2016-01-115867-027-08305.10 ppb
2016-01-115867-028-08012.20 ppb
2016-01-115867-029-12561.70 ppb
2016-01-115867-030-13312.00 ppb
2016-01-115867-031-13151.70 ppb
2016-01-115867-032-11391.60 ppb
2016-01-115867-033-09121.50 ppb
2016-01-115867-035-12211.20 ppb
2016-01-115867-036-09282.20 ppb
2016-04-045867-004-08401.000 ppb
2016-04-055867-022-09300.500 ppb
2016-04-055867-023-10000.500 ppb
2016-04-065867-018-11000.600 ppb
2016-04-065867-019-10300.900 ppb
2016-04-065867-020-13050.800 ppb
2016-04-065867-021-11500.900 ppb
2016-04-115867-025-13392.00 ppb
2016-04-115867-026-14301.80 ppb
2016-04-115867-027-15058.90 ppb
2016-04-115867-028-07567.10 ppb
2016-04-115867-029-10442.40 ppb
2016-04-115867-030-13052.00 ppb
2016-04-115867-031-12312.10 ppb
2016-04-115867-032-11181.90 ppb
2016-04-115867-033-08351.90 ppb
2016-04-115867-034-09301.90 ppb
2016-04-115867-035-10062.10 ppb
2016-04-115867-036-09022.10 ppb
2016-07-125867-025-1322ND
2016-07-125867-026-12081.000 ppb
2016-07-125867-027-0844ND
2016-07-125867-028-0800ND
2016-07-125867-029-11521.000 ppb
2016-07-125867-030-12531.000 ppb
2016-07-125867-031-12221.000 ppb
2016-07-125867-032-11041.000 ppb
2016-07-125867-033-09091.10 ppb
2016-07-125867-034-09521.000 ppb
2016-07-125867-035-1043ND
2016-07-125867-036-0934ND
2016-10-125867-025-13261.50 ppb
2016-10-125867-026-14181.70 ppb
2016-10-125867-027-08332.00 ppb
2016-10-125867-028-08021.70 ppb
2016-10-125867-029-12022.10 ppb
2016-10-125867-030-12542.30 ppb
2016-10-125867-031-12391.40 ppb
2016-10-125867-032-10221.40 ppb
2016-10-125867-033-08541.70 ppb
2016-10-125867-034-09301.70 ppb
2016-10-125867-035-10031.60 ppb
2016-10-125867-036-09091.70 ppb
2016-11-075867-004-07451.30 ppb
2017-01-095867-025-14002.30 ppb
2017-01-095867-026-14332.90 ppb
2017-01-095867-027-09062.20 ppb
2017-01-095867-028-08322.60 ppb
2017-01-095867-029-12302.10 ppb
2017-01-095867-030-13262.60 ppb
2017-01-095867-031-13112.20 ppb
2017-01-095867-032-11332.30 ppb
2017-01-095867-033-09342.90 ppb
2017-01-095867-034-10023.00 ppb
2017-01-095867-035-11022.60 ppb
2017-01-095867-036-10232.10 ppb
2017-03-215867-004-10401.10 ppb
2017-04-105867-025-13242.00 ppb
2017-04-105867-026-14012.20 ppb
2017-04-105867-027-08302.00 ppb
2017-04-105867-028-08002.00 ppb
2017-04-105867-029-11572.10 ppb
2017-04-105867-030-12371.90 ppb
2017-04-105867-031-12221.90 ppb
2017-04-105867-032-11101.70 ppb
2017-04-105867-033-08561.80 ppb
2017-04-105867-034-10091.90 ppb
2017-04-105867-035-10432.20 ppb
2017-04-105867-036-09171.90 ppb
2017-04-175867-008-100514.6 ppb
2017-04-175867-009-12454.80 ppb
2017-04-185867-006-113011.8 ppb
2017-04-195867-011-105015.7 ppb
2017-07-125867-025-13462.00 ppb
2017-07-125867-026-13101.000 ppb
2017-07-125867-027-0811ND
2017-07-125867-028-07451.000 ppb
2017-07-125867-029-11521.000 ppb
2017-07-125867-030-1243ND
2017-07-125867-031-12222.00 ppb
2017-07-125867-032-11131.000 ppb
2017-07-125867-033-08461.000 ppb
2017-07-125867-034-09491.000 ppb
2017-07-125867-035-10432.00 ppb
2017-07-125867-036-09122.00 ppb
2017-10-095867-025-13332.00 ppb
2017-10-095867-026-13052.00 ppb
2017-10-095867-027-08201.000 ppb
2017-10-095867-028-07452.00 ppb
2017-10-095867-029-11412.00 ppb
2017-10-095867-030-12212.00 ppb
2017-10-095867-031-12052.00 ppb
2017-10-095867-032-11102.00 ppb
2017-10-095867-033-09272.00 ppb
2017-10-095867-034-09572.00 ppb
2017-10-095867-035-10372.00 ppb
2017-10-165867-004-08552.30 ppb
2017-11-065867-007-10153.90 ppb
2017-11-065867-010-11204.00 ppb
2018-01-085867-025-13302.00 ppb
2018-01-085867-026-14152.00 ppb
2018-01-085867-027-09002.00 ppb
2018-01-085867-028-08302.00 ppb
2018-01-085867-029-11402.00 ppb
2018-01-085867-030-12552.00 ppb
2018-01-085867-031-12352.00 ppb
2018-01-085867-032-11122.00 ppb
2018-01-085867-033-09202.00 ppb
2018-01-085867-034-10102.00 ppb
2018-01-085867-035-10352.00 ppb
2018-01-085867-036-09502.00 ppb
2018-02-135867-015-10503.00 ppb
2018-02-135867-016-09453.00 ppb
2018-02-265867-004-09151.30 ppb
2018-03-075867-013-13203.10 ppb
2018-03-085867-012-10003.30 ppb
2018-03-085867-014-13302.60 ppb
2018-04-095867-025-14223.00 ppb
2018-04-095867-026-13557.00 ppb
2018-04-095867-027-08403.00 ppb
2018-04-095867-028-08093.00 ppb
2018-04-095867-029-12364.00 ppb
2018-04-095867-030-13244.00 ppb
2018-04-095867-031-13116.00 ppb
2018-04-095867-032-11316.00 ppb
2018-04-095867-033-09155.00 ppb
2018-04-095867-034-10177.00 ppb
2018-04-095867-035-110014.0 ppb
2018-04-095867-036-09406.00 ppb
2018-04-305867-017-10302.80 ppb
2018-07-095867-025-10321.000 ppb
2018-07-095867-026-09551.000 ppb
2018-07-095867-027-0820ND
2018-07-095867-028-0747ND
2018-07-095867-029-1255ND
2018-07-095867-030-1150ND
2018-07-095867-031-12291.000 ppb
2018-07-095867-032-1411ND
2018-07-095867-033-0850ND
2018-07-095867-034-11171.000 ppb
2018-07-095867-035-1350ND
2018-10-085867-025-1306ND
2018-10-085867-026-1243ND
2018-10-085867-027-0813ND
2018-10-085867-028-0738ND
2018-10-085867-029-1137ND
2018-10-085867-030-12111.000 ppb
2018-10-085867-031-11551.000 ppb
2018-10-085867-032-10551.000 ppb
2018-10-085867-033-09161.000 ppb
2018-10-085867-034-0957ND
2018-10-085867-035-10211.000 ppb
2018-10-085867-036-0841ND
2018-11-055867-004-08201.70 ppb
2019-01-085867-025-14122.00 ppb
2019-01-085867-026-1343ND
2019-01-085867-027-08121.000 ppb
2019-01-085867-028-07392.00 ppb
2019-01-085867-029-11421.000 ppb
2019-01-085867-030-1221ND
2019-01-085867-031-12091.000 ppb
2019-01-085867-032-1057ND
2019-01-085867-033-08512.00 ppb
2019-01-085867-034-10042.00 ppb
2019-01-085867-035-1036ND
2019-01-085867-036-09212.00 ppb
2019-01-295867-004-0930ND
2019-02-045867-018-09451.30 ppb
2019-02-055867-022-10201.30 ppb
2019-02-055867-023-09451.50 ppb
2019-02-075867-020-08401.20 ppb
2019-02-195867-019-11001.30 ppb
2019-04-085867-025-1346ND
2019-04-085867-026-13121.000 ppb
2019-04-085867-027-0831ND
2019-04-085867-028-0752ND
2019-04-085867-029-1203ND
2019-04-085867-030-1247ND
2019-04-085867-031-1231ND
2019-04-085867-032-1104ND
2019-04-085867-033-0903ND
2019-04-085867-034-0954ND
2019-04-085867-035-1041ND
2019-04-085867-036-0935ND
2019-07-085867-025-14171.000 ppb
2019-07-085867-026-13302.00 ppb
2019-07-085867-027-08371.000 ppb
2019-07-085867-028-08101.000 ppb
2019-07-085867-029-1222ND
2019-07-085867-030-13062.00 ppb
2019-07-085867-031-12471.000 ppb
2019-07-085867-032-11172.00 ppb
2019-07-085867-033-09231.000 ppb
2019-07-085867-034-10121.000 ppb
2019-07-085867-035-10561.000 ppb
2019-07-085867-036-09521.000 ppb
2019-10-075867-026-11471.000 ppb
2019-10-075867-027-0827ND
2019-10-075867-028-0753ND
2019-10-075867-029-13521.000 ppb
2019-10-075867-030-13131.000 ppb
2019-10-075867-031-1331ND
2019-10-075867-032-1046ND
2019-10-075867-033-08551.000 ppb
2019-10-075867-034-09571.000 ppb
2019-10-075867-035-14361.000 ppb
2019-10-075867-036-09271.000 ppb
2019-11-045867-004-08003.40 ppb