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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Clwsc Canyon Lake Shores

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

 

180

Samples

0

Samples exceeding legal limit (MCL)

138

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20146.29 ppb2825ND - 20.7 ppb
201513.6 ppb3325ND - 77.0 ppb
20166.07 ppb3225ND - 23.2 ppb
20179.13 ppb2822ND - 37.0 ppb
20185.59 ppb3221ND - 24.0 ppb
20195.61 ppb2720ND - 19.0 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
2014-02-18AC433512.70 ppb
2014-02-18AC433305.00 ppb
2014-02-18AC433176.60 ppb
2014-02-18AC433372.90 ppb
2014-02-18AC433124.30 ppb
2014-02-18AC433595.30 ppb
2014-04-30AC52370ND
2014-04-30AC524846.70 ppb
2014-04-30AC524987.00 ppb
2014-04-30AC524851.20 ppb
2014-04-30AC524834.50 ppb
2014-04-30AC523727.70 ppb
2014-04-30AC52368ND
2014-09-03AC656492.00 ppb
2014-09-03AC6572112.4 ppb
2014-09-03AC657209.60 ppb
2014-09-03AC657232.20 ppb
2014-09-03AC6572617.3 ppb
2014-09-03AC65659ND
2014-10-08AC691956.00 ppb
2014-10-08AC691991.000 ppb
2014-10-08AC6917520.7 ppb
2014-10-08AC691744.40 ppb
2014-10-08AC691773.10 ppb
2014-10-08AC6917314.2 ppb
2014-10-08AC692050.500 ppb
2014-10-08AC692039.80 ppb
2014-10-08AC6919719.0 ppb
2015-02-03AC790261.50 ppb
2015-02-03AC79030ND
2015-02-03AC790282.60 ppb
2015-02-03AC790059.00 ppb
2015-02-03AC790126.10 ppb
2015-02-03AC790065.70 ppb
2015-02-03AC790047.60 ppb
2015-03-26AC86265ND
2015-03-26AC86267ND
2015-03-26AC862758.40 ppb
2015-03-26AC8626112.0 ppb
2015-03-26AC86307ND
2015-03-26AC862476.40 ppb
2015-03-26AC8627915.0 ppb
2015-05-13AC91861ND
2015-05-13AC9181815.2 ppb
2015-05-13AC918145.90 ppb
2015-05-13AC918066.30 ppb
2015-05-13AC9180910.5 ppb
2015-05-13AC9185112.0 ppb
2015-08-12AD03868ND
2015-08-12AD03860ND
2015-08-12AD03864ND
2015-08-12AD038589.60 ppb
2015-08-12AD0380723.2 ppb
2015-08-12AD0380616.1 ppb
2015-08-12AD0381116.6 ppb
2015-08-12AD0381325.5 ppb
2015-11-03AD1238238.5 ppb
2015-11-03AD1238533.8 ppb
2015-11-03AD1238635.0 ppb
2015-11-03AD1238350.0 ppb
2015-12-07AD1579877.0 ppb
2016-02-03AD21858ND
2016-02-03AD21852ND
2016-02-03AD21854ND
2016-02-03AD2176823.2 ppb
2016-02-03AD217995.00 ppb
2016-02-03AD218021.10 ppb
2016-02-03AD2176913.1 ppb
2016-03-09AD27909ND
2016-03-09AD27915ND
2016-03-09AD27907ND
2016-03-09AD2789910.00 ppb
2016-03-09AD279131.10 ppb
2016-04-27AD344467.40 ppb
2016-04-27AD3444823.0 ppb
2016-04-27AD343766.80 ppb
2016-04-27AD3437310.9 ppb
2016-04-27AD343705.00 ppb
2016-04-27AD3437713.9 ppb
2016-07-26AD4571918.0 ppb
2016-07-26AD457312.40 ppb
2016-07-26AD456798.90 ppb
2016-07-26AD456784.70 ppb
2016-07-26AD456751.20 ppb
2016-07-26AD4567110.3 ppb
2016-07-26AD45729ND
2016-07-26AD457232.90 ppb
2016-10-04AD524281.10 ppb
2016-10-04AD524276.10 ppb
2016-10-04AD524313.30 ppb
2016-10-04AD5243210.3 ppb
2016-10-04AD524871.70 ppb
2016-12-01AD598802.90 ppb
2017-01-25AD66818ND
2017-01-25AD668382.10 ppb
2017-01-25AD66788ND
2017-01-25AD667869.10 ppb
2017-01-25AD667893.70 ppb
2017-01-25AD6678712.9 ppb
2017-02-24AD72107ND
2017-04-11AD792188.90 ppb
2017-04-11AD792102.20 ppb
2017-04-11AD792283.50 ppb
2017-04-11AD791798.50 ppb
2017-04-11AD7917710.9 ppb
2017-04-11AD791783.60 ppb
2017-04-11AD7917611.1 ppb
2017-06-27AD87926ND
2017-06-27AD87930ND
2017-06-27AD8792437.0 ppb
2017-07-24AD9037613.0 ppb
2017-07-24AD903742.60 ppb
2017-07-24AD9030010.1 ppb
2017-07-24AD9033111.7 ppb
2017-07-24AD903352.20 ppb
2017-07-24AD9033020.3 ppb
2017-10-05AD9958934.0 ppb
2017-10-05AD99541ND
2017-10-05AD9953610.1 ppb
2017-10-05AD995356.80 ppb
2017-10-05AD9953431.2 ppb
2018-02-07AE12787ND
2018-02-07AE127835.80 ppb
2018-02-07AE12781ND
2018-02-07AE127157.10 ppb
2018-02-07AE127134.20 ppb
2018-02-07AE127191.40 ppb
2018-02-07AE127175.70 ppb
2018-05-16AE266101.10 ppb
2018-05-16AE26608ND
2018-05-16AE265249.80 ppb
2018-05-16AE265544.60 ppb
2018-05-16AE265534.20 ppb
2018-05-16AE265308.80 ppb
2018-05-16AE26612ND
2018-05-17AE26809ND
2018-05-17AE26813ND
2018-05-17AE26795ND
2018-05-17AE26811ND
2018-05-17AE26807ND
2018-05-17AE26793ND
2018-07-26AE3470024.0 ppb
2018-07-26AE346822.50 ppb
2018-07-26AE346457.90 ppb
2018-07-26AE346443.20 ppb
2018-07-26AE346514.20 ppb
2018-07-26AE346504.60 ppb
2018-07-26AE3468021.0 ppb
2018-11-06AE4536922.2 ppb
2018-11-06AE4537020.0 ppb
2018-11-06AE453642.10 ppb
2018-11-06AE4536514.4 ppb
2018-11-06AE45425ND
2019-02-06AE532128.30 ppb
2019-02-06AE532142.70 ppb
2019-02-06AE53216ND
2019-02-06AE531661.40 ppb
2019-02-06AE531687.50 ppb
2019-02-06AE531671.90 ppb
2019-02-06AE5316912.1 ppb
2019-04-23AE63386ND
2019-04-23AE63384ND
2019-04-23AE63355ND
2019-04-23AE6336013.8 ppb
2019-04-23AE633534.10 ppb
2019-04-23AE633599.50 ppb
2019-08-20AE79904ND
2019-08-20AE799083.10 ppb
2019-08-20AE7980116.3 ppb
2019-08-20AE798004.20 ppb
2019-08-20AE797991.20 ppb
2019-08-20AE7979810.1 ppb
2019-10-29AE8783813.2 ppb
2019-10-29AE8783910.8 ppb
2019-10-29AE878472.30 ppb
2019-10-29AE878498.00 ppb
2019-10-30AE88006ND
2019-10-30AE88008ND
2019-10-30AE880021.90 ppb
2019-10-30AE8800419.0 ppb