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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Wailuku

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

 

130

Samples

0

Samples exceeding legal limit (MCL)

29

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014N/A00N/A
20150.219 ppb3811ND - 1.20 ppb
20160.104 ppb273ND - 1.60 ppb
2017ND270ND
2018ND200ND
20191.87 ppb1815ND - 20.0 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
2015-01-14201501190213ND
2015-01-14201501190214ND
2015-01-14201501190215ND
2015-01-142015011902160.540 ppb
2015-01-14201501190218ND
2015-01-142015011902190.540 ppb
2015-01-15201501190223ND
2015-01-15201501190224ND
2015-01-26201501280565ND
2015-01-26201501280741ND
2015-01-26201501280752ND
2015-01-262015012807530.630 ppb
2015-04-09201504140817ND
2015-04-09201504140818ND
2015-04-09201504140819ND
2015-04-092015041408200.530 ppb
2015-04-092015041408311.20 ppb
2015-04-092015041408321.000 ppb
2015-04-092015041408331.10 ppb
2015-04-092015041408341.000 ppb
2015-06-16201506180519ND
2015-07-222015072402720.580 ppb
2015-07-22201507240273ND
2015-07-22201507240274ND
2015-07-22201507240275ND
2015-07-22201507240276ND
2015-07-22201507240277ND
2015-07-22201507240278ND
2015-07-22201507240279ND
2015-09-08201509100855ND
2015-10-09201510130316ND
2015-10-092015101303170.610 ppb
2015-10-09201510130318ND
2015-10-092015101303190.590 ppb
2015-10-09201510130320ND
2015-10-09201510130321ND
2015-10-09201510130322ND
2015-10-09201510130323ND
2016-01-15ND
2016-01-15ND
2016-01-15ND
2016-01-15ND
2016-01-15ND
2016-01-15ND
2016-01-15ND
2016-01-150.630 ppb
2016-02-231.60 ppb
2016-02-26ND
2016-02-26ND
2016-02-26ND
2016-04-14ND
2016-04-14ND
2016-04-14ND
2016-04-14ND
2016-07-15ND
2016-07-15ND
2016-07-15ND
2016-07-150.580 ppb
2016-09-12ND
2016-10-06ND
2016-10-06ND
2016-10-06ND
2016-10-06ND
2016-11-30ND
2016-11-30ND
2017-01-13ND
2017-01-13ND
2017-01-13ND
2017-01-13ND
2017-01-31ND
2017-01-31ND
2017-01-31ND
2017-02-24ND
2017-02-24ND
2017-02-27ND
2017-02-27ND
2017-02-27ND
2017-04-06ND
2017-04-06ND
2017-04-06ND
2017-04-06ND
2017-05-19ND
2017-05-19ND
2017-07-13ND
2017-07-13ND
2017-07-13ND
2017-07-13ND
2017-09-21ND
2017-10-06ND
2017-10-06ND
2017-10-06ND
2017-10-06ND
2018-01-11201801180640ND
2018-01-11201801180643ND
2018-01-11201801180642ND
2018-01-11201801180641ND
2018-01-30201801030999ND
2018-01-31201801030998ND
2018-01-31201801031000ND
2018-04-05201804100503ND
2018-04-05201804100506ND
2018-04-05201804100505ND
2018-04-05201804100504ND
2018-05-17201805180453ND
2018-07-02201807060176ND
2018-07-02201807060179ND
2018-07-02201807060178ND
2018-07-02201807060177ND
2018-10-04201810090382ND
2018-10-04201810090385ND
2018-10-04201810090384ND
2018-10-04201810090383ND
2019-01-032019010800771.20 ppb
2019-01-03201901080080ND
2019-01-032019010800790.740 ppb
2019-01-032019010800781.70 ppb
2019-02-0420190205017820.0 ppb
2019-03-07201903120187ND
2019-04-052019040904740.600 ppb
2019-04-052019040904770.580 ppb
2019-04-05201904090476ND
2019-04-052019040904750.800 ppb
2019-07-262019073003380.950 ppb
2019-07-262019073003410.760 ppb
2019-07-262019073003400.590 ppb
2019-07-262019073003390.740 ppb
2019-10-032019100806041.30 ppb
2019-10-032019100806071.000 ppb
2019-10-032019100806061.50 ppb
2019-10-032019100806051.20 ppb