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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Crescenta Valley CWD

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

 

218

Samples

0

Samples exceeding legal limit (MCL)

211

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
20149.72 ppb2320ND - 21.0 ppb
20158.67 ppb2726ND - 19.0 ppb
201610.8 ppb6462ND - 26.0 ppb
201712.2 ppb29290.870 ppb - 32.0 ppb
20189.16 ppb14140.890 ppb - 15.0 ppb
20194.95 ppb6160ND - 14.0 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
2014-02-045806-800-103418.0 ppb
2014-02-045806-801-085014.0 ppb
2014-02-045806-802-115014.0 ppb
2014-02-045806-803-102017.0 ppb
2014-05-065806-008-114721.0 ppb
2014-05-065806-801-112021.0 ppb
2014-05-065806-802-101715.0 ppb
2014-05-065806-803-120019.0 ppb
2014-08-055806-001-1130ND
2014-08-055806-002-10561.50 ppb
2014-08-055806-005-1135ND
2014-08-055806-006-13201.60 ppb
2014-08-055806-007-10301.60 ppb
2014-08-055806-009-10300.920 ppb
2014-08-055806-010-13401.10 ppb
2014-08-055806-011-09501.20 ppb
2014-08-055806-012-12451.60 ppb
2014-08-055806-013-11560.970 ppb
2014-08-055806-800-101421.0 ppb
2014-08-055806-801-093718.0 ppb
2014-08-055806-802-115215.0 ppb
2014-08-055806-803-112020.0 ppb
2014-09-165806-008-0908ND
2015-02-035806-800-08499.60 ppb
2015-02-035806-801-080312.0 ppb
2015-02-035806-802-09107.70 ppb
2015-02-035806-803-085811.0 ppb
2015-05-055806-001-1120ND
2015-05-055806-002-11572.20 ppb
2015-05-055806-005-12152.10 ppb
2015-05-055806-006-13022.40 ppb
2015-05-055806-007-11282.70 ppb
2015-05-055806-008-12431.90 ppb
2015-05-055806-009-10281.80 ppb
2015-05-055806-010-13192.10 ppb
2015-05-055806-011-11012.00 ppb
2015-05-055806-012-13182.70 ppb
2015-05-055806-013-12551.80 ppb
2015-05-055806-800-120513.0 ppb
2015-05-055806-801-085716.0 ppb
2015-05-055806-802-100513.0 ppb
2015-05-055806-803-115516.0 ppb
2015-08-045806-800-101713.0 ppb
2015-08-045806-801-112019.0 ppb
2015-08-045806-802-111011.0 ppb
2015-08-045806-803-100213.0 ppb
2015-11-035806-800-101014.0 ppb
2015-11-035806-801-105516.0 ppb
2015-11-035806-802-100111.0 ppb
2015-11-035806-803-102817.0 ppb
2016-02-025806-800-10558.20 ppb
2016-02-025806-801-101511.0 ppb
2016-02-025806-802-10406.80 ppb
2016-02-025806-803-10409.80 ppb
2016-02-115806-027-0940ND
2016-05-035806-001-10483.80 ppb
2016-05-035806-002-12251.20 ppb
2016-05-035806-005-12101.20 ppb
2016-05-035806-006-13231.60 ppb
2016-05-035806-007-11101.40 ppb
2016-05-035806-008-13000.880 ppb
2016-05-035806-009-11010.850 ppb
2016-05-035806-010-13011.000 ppb
2016-05-035806-011-11501.10 ppb
2016-05-035806-013-12401.000 ppb
2016-05-035806-027-12150.880 ppb
2016-05-045806-027-13020.900 ppb
2016-05-045806-800-10487.70 ppb
2016-05-045806-801-11059.90 ppb
2016-05-045806-802-10226.70 ppb
2016-05-045806-803-103311.0 ppb
2016-06-075806-012-11102.00 ppb
2016-08-025806-027-08581.10 ppb
2016-08-025806-800-121019.0 ppb
2016-08-025806-801-123025.0 ppb
2016-08-025806-802-124020.0 ppb
2016-08-025806-803-115826.0 ppb
2016-08-155806-800-093818.0 ppb
2016-08-155806-801-100022.0 ppb
2016-08-155806-802-095415.0 ppb
2016-08-155806-803-092522.0 ppb
2016-09-135806-800-09499.20 ppb
2016-09-135806-801-100514.0 ppb
2016-09-135806-802-101513.0 ppb
2016-09-135806-803-093717.0 ppb
2016-09-205806-800-090010.00 ppb
2016-09-205806-801-091816.0 ppb
2016-09-205806-802-093017.0 ppb
2016-09-205806-803-084915.0 ppb
2016-09-275806-800-100311.0 ppb
2016-09-275806-801-102118.0 ppb
2016-09-275806-802-104015.0 ppb
2016-09-275806-803-094615.0 ppb
2016-10-045806-800-094213.0 ppb
2016-10-045806-801-102814.0 ppb
2016-10-045806-802-114013.0 ppb
2016-10-045806-803-092517.0 ppb
2016-10-115806-800-091412.0 ppb
2016-10-115806-801-092715.0 ppb
2016-10-115806-802-103411.0 ppb
2016-10-115806-803-090118.0 ppb
2016-10-185806-800-09409.30 ppb
2016-10-185806-801-102712.0 ppb
2016-10-185806-802-100810.00 ppb
2016-10-185806-803-092113.0 ppb
2016-10-255806-800-094114.0 ppb
2016-10-255806-801-100016.0 ppb
2016-10-255806-802-101514.0 ppb
2016-10-255806-803-092417.0 ppb
2016-11-085806-027-1120ND
2016-11-085806-800-093611.0 ppb
2016-11-085806-801-091511.0 ppb
2016-11-085806-802-092310.00 ppb
2016-11-085806-803-095114.0 ppb
2017-02-075806-800-10379.20 ppb
2017-02-075806-801-10509.40 ppb
2017-02-075806-802-102610.00 ppb
2017-02-075806-803-102011.0 ppb
2017-02-215806-001-11252.70 ppb
2017-02-215806-002-11251.70 ppb
2017-02-215806-005-11001.40 ppb
2017-02-215806-006-13086.20 ppb
2017-02-215806-007-10301.90 ppb
2017-02-215806-009-10131.10 ppb
2017-02-215806-010-12501.50 ppb
2017-02-215806-011-11451.50 ppb
2017-02-215806-012-12451.50 ppb
2017-02-215806-013-09411.20 ppb
2017-02-215806-027-09141.40 ppb
2017-04-245806-006-13331.70 ppb
2017-05-025806-800-090531.0 ppb
2017-05-025806-801-085125.0 ppb
2017-05-025806-802-123032.0 ppb
2017-05-025806-803-092031.0 ppb
2017-07-265806-008-08000.870 ppb
2017-08-015806-800-100024.0 ppb
2017-08-015806-801-094023.0 ppb
2017-08-015806-802-115125.0 ppb
2017-08-015806-803-101528.0 ppb
2017-11-075806-800-100018.0 ppb
2017-11-075806-801-103519.0 ppb
2017-11-075806-802-114310.00 ppb
2017-11-075806-803-094023.0 ppb
2018-02-065806-010-12482.20 ppb
2018-02-065806-800-101513.0 ppb
2018-02-065806-801-103915.0 ppb
2018-02-065806-802-09416.50 ppb
2018-02-065806-803-100015.0 ppb
2018-05-015806-008-11300.890 ppb
2018-05-025806-800-095014.0 ppb
2018-05-025806-801-102511.0 ppb
2018-05-025806-802-10479.20 ppb
2018-05-025806-803-093014.0 ppb
2018-11-135806-800-10406.30 ppb
2018-11-135806-801-09406.80 ppb
2018-11-135806-802-10116.90 ppb
2018-11-135806-803-12307.50 ppb
2019-01-155806-800-10153.70 ppb
2019-01-155806-801-09125.60 ppb
2019-01-155806-802-09255.50 ppb
2019-01-155806-803-10005.30 ppb
2019-02-125806-001-1021ND
2019-02-125806-002-09501.40 ppb
2019-02-125806-005-10151.30 ppb
2019-02-125806-007-10052.00 ppb
2019-02-125806-008-11500.890 ppb
2019-02-125806-009-08541.10 ppb
2019-02-125806-010-12151.20 ppb
2019-02-125806-011-08411.50 ppb
2019-02-125806-012-12251.40 ppb
2019-02-125806-013-11301.20 ppb
2019-02-125806-027-12051.30 ppb
2019-03-055806-800-11354.50 ppb
2019-03-055806-801-10504.60 ppb
2019-03-055806-803-11505.50 ppb
2019-04-025806-800-11003.60 ppb
2019-04-025806-801-09405.10 ppb
2019-04-025806-802-10035.80 ppb
2019-04-025806-803-10405.30 ppb
2019-05-075806-800-10454.40 ppb
2019-05-075806-801-11055.90 ppb
2019-05-075806-802-11467.30 ppb
2019-05-075806-803-10056.60 ppb
2019-06-045806-800-10103.40 ppb
2019-06-045806-801-10353.80 ppb
2019-06-045806-802-11286.80 ppb
2019-06-045806-803-09504.20 ppb
2019-06-255806-028-09580.630 ppb
2019-07-025806-028-12250.590 ppb
2019-07-025806-800-09304.90 ppb
2019-07-025806-801-101510.00 ppb
2019-07-025806-802-100011.0 ppb
2019-07-025806-803-09456.70 ppb
2019-08-055806-800-125814.0 ppb
2019-08-055806-801-122512.0 ppb
2019-08-055806-802-123710.00 ppb
2019-08-055806-803-131512.0 ppb
2019-08-065806-028-10010.620 ppb
2019-09-035806-028-12400.500 ppb
2019-09-175806-800-112011.0 ppb
2019-09-175806-801-09307.40 ppb
2019-09-175806-802-10088.30 ppb
2019-09-175806-803-105713.0 ppb
2019-10-015806-028-11230.670 ppb
2019-10-155806-800-10367.00 ppb
2019-10-155806-801-10307.10 ppb
2019-10-155806-802-10207.50 ppb
2019-10-155806-803-11099.00 ppb
2019-11-045806-028-12270.540 ppb
2019-11-045806-800-10005.50 ppb
2019-11-045806-801-09155.30 ppb
2019-11-045806-802-13145.10 ppb
2019-11-045806-803-10156.10 ppb
2019-12-035806-028-11540.770 ppb
2019-12-175806-800-10273.20 ppb
2019-12-175806-801-09404.10 ppb
2019-12-175806-802-10522.80 ppb
2019-12-175806-803-10054.70 ppb