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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

Dublin San Ramon Services 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.

 

31

Samples

0

Samples exceeding legal limit (MCL)

20

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
20141.97 ppb197ND - 14.0 ppb
20150.810 ppb104ND - 4.40 ppb
20160.663 ppb84ND - 2.10 ppb
20173.22 ppb93ND - 11.4 ppb
20181.54 ppb154ND - 9.10 ppb
20194.64 ppb3120ND - 13.2 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
2019-04-171272-804-11042.09 ppb
2019-04-171272-807-1044ND
2019-04-171272-806-0927ND
2019-04-171272-805-09481.73 ppb
2019-04-171272-808-0907ND
2019-04-171272-803-1118ND
2019-04-171272-801-08412.75 ppb
2019-04-171272-802-10191.95 ppb
2019-08-071272-801-12059.90 ppb
2019-08-071272-807-10036.90 ppb
2019-08-071272-806-113812.7 ppb
2019-08-071272-805-104410.5 ppb
2019-08-071272-804-094411.2 ppb
2019-08-071272-808-112413.2 ppb
2019-08-071272-803-09049.50 ppb
2019-08-071272-802-110410.5 ppb
2019-10-071272-804-09306.60 ppb
2019-10-071272-803-0840ND
2019-10-071272-805-10165.80 ppb
2019-10-071272-807-09484.20 ppb
2019-10-071272-801-09488.50 ppb
2019-10-071272-806-10556.80 ppb
2019-10-071272-808-11086.50 ppb
2019-10-071272-802-10406.90 ppb
2019-11-201272-808-0940ND
2019-11-201272-806-0959ND
2019-11-201272-805-1044ND
2019-11-201272-804-11355.70 ppb
2019-11-201272-803-1151ND
2019-11-201272-802-1026ND
2019-11-201272-801-0907ND