Chloroform
City of Durham
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.
Testing results - average by year
Year | Average result | Samples taken | Detections | Range of results |
---|---|---|---|---|
2013 | N/A | 0 | 0 | N/A |
2014 | 36.9 ppb | 48 | 48 | 19.0 ppb - 52.0 ppb |
2015 | 33.6 ppb | 48 | 48 | 18.0 ppb - 43.0 ppb |
2016 | 37.0 ppb | 48 | 48 | 20.0 ppb - 57.0 ppb |
2017 | 41.5 ppb | 48 | 48 | 8.20 ppb - 56.0 ppb |
2018 | 46.0 ppb | 48 | 48 | 15.0 ppb - 76.0 ppb |
2019 | 29.4 ppb | 48 | 48 | 4.40 ppb - 40.0 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 |
---|---|---|
2014-02-11 | C400987-03 | 26.0 ppb |
2014-02-11 | C400987-04 | 28.0 ppb |
2014-02-11 | C400987-05 | 28.0 ppb |
2014-02-11 | C400987-06 | 25.0 ppb |
2014-02-11 | C400987-07 | 28.0 ppb |
2014-02-11 | C400987-08 | 25.0 ppb |
2014-02-11 | C400987-09 | 25.0 ppb |
2014-02-11 | C400987-10 | 24.0 ppb |
2014-02-11 | C400987-11 | 28.0 ppb |
2014-02-11 | C400987-12 | 26.0 ppb |
2014-02-11 | C400987-13 | 19.0 ppb |
2014-02-11 | C400987-14 | 26.0 ppb |
2014-05-13 | C405354-03 | 33.0 ppb |
2014-05-13 | C405354-04 | 32.0 ppb |
2014-05-13 | C405354-05 | 33.0 ppb |
2014-05-13 | C405354-06 | 31.0 ppb |
2014-05-13 | C405354-07 | 31.0 ppb |
2014-05-13 | C405354-08 | 31.0 ppb |
2014-05-13 | C405354-09 | 32.0 ppb |
2014-05-13 | C405354-10 | 31.0 ppb |
2014-05-13 | C405354-11 | 32.0 ppb |
2014-05-13 | C405354-12 | 32.0 ppb |
2014-05-13 | C405354-13 | 31.0 ppb |
2014-05-13 | C405354-14 | 32.0 ppb |
2014-08-12 | C409625-03 | 52.0 ppb |
2014-08-12 | C409625-04 | 52.0 ppb |
2014-08-12 | C409625-05 | 50.0 ppb |
2014-08-12 | C409625-06 | 47.0 ppb |
2014-08-12 | C409625-07 | 52.0 ppb |
2014-08-12 | C409625-08 | 49.0 ppb |
2014-08-12 | C409625-09 | 50.0 ppb |
2014-08-12 | C409625-10 | 41.0 ppb |
2014-08-12 | C409625-11 | 52.0 ppb |
2014-08-12 | C409625-12 | 51.0 ppb |
2014-08-12 | C409625-13 | 36.0 ppb |
2014-08-12 | C409625-14 | 50.0 ppb |
2014-11-11 | C414066-03 | 45.0 ppb |
2014-11-11 | C414066-12 | 47.0 ppb |
2014-11-11 | C414066-13 | 29.0 ppb |
2014-11-11 | C414066-14 | 42.0 ppb |
2014-11-11 | C414066-04 | 44.0 ppb |
2014-11-11 | C414066-05 | 44.0 ppb |
2014-11-11 | C414066-06 | 42.0 ppb |
2014-11-11 | C414066-07 | 44.0 ppb |
2014-11-11 | C414066-08 | 45.0 ppb |
2014-11-11 | C414066-09 | 44.0 ppb |
2014-11-11 | C414066-10 | 31.0 ppb |
2014-11-11 | C414066-11 | 42.0 ppb |
2015-02-10 | 24.0 ppb | |
2015-02-10 | 24.0 ppb | |
2015-02-10 | 24.0 ppb | |
2015-02-10 | 25.0 ppb | |
2015-02-10 | 25.0 ppb | |
2015-02-10 | 25.0 ppb | |
2015-02-10 | 24.0 ppb | |
2015-02-10 | 20.0 ppb | |
2015-02-10 | 24.0 ppb | |
2015-02-10 | 27.0 ppb | |
2015-02-10 | 18.0 ppb | |
2015-02-10 | 25.0 ppb | |
2015-05-12 | 37.0 ppb | |
2015-05-12 | 34.0 ppb | |
2015-05-12 | 33.0 ppb | |
2015-05-12 | 30.0 ppb | |
2015-05-12 | 34.0 ppb | |
2015-05-12 | 38.0 ppb | |
2015-05-12 | 38.0 ppb | |
2015-05-12 | 25.0 ppb | |
2015-05-12 | 34.0 ppb | |
2015-05-12 | 35.0 ppb | |
2015-05-12 | 24.0 ppb | |
2015-05-12 | 33.0 ppb | |
2015-08-10 | 37.0 ppb | |
2015-08-10 | 42.0 ppb | |
2015-08-10 | 42.0 ppb | |
2015-08-10 | 43.0 ppb | |
2015-08-10 | 41.0 ppb | |
2015-08-10 | 39.0 ppb | |
2015-08-10 | 39.0 ppb | |
2015-08-10 | 32.0 ppb | |
2015-08-10 | 41.0 ppb | |
2015-08-10 | 42.0 ppb | |
2015-08-10 | 28.0 ppb | |
2015-08-10 | 40.0 ppb | |
2015-11-11 | 41.0 ppb | |
2015-11-11 | 36.0 ppb | |
2015-11-11 | 42.0 ppb | |
2015-11-11 | 39.0 ppb | |
2015-11-11 | 40.0 ppb | |
2015-11-11 | 42.0 ppb | |
2015-11-11 | 42.0 ppb | |
2015-11-11 | 36.0 ppb | |
2015-11-11 | 39.0 ppb | |
2015-11-11 | 41.0 ppb | |
2015-11-11 | 34.0 ppb | |
2015-11-11 | 33.0 ppb | |
2016-02-09 | CZ01069-03 | 21.0 ppb |
2016-02-09 | CZ01069-04 | 22.0 ppb |
2016-02-09 | CZ01069-05 | 22.0 ppb |
2016-02-09 | CZ01069-06 | 20.0 ppb |
2016-02-09 | CZ01069-07 | 22.0 ppb |
2016-02-09 | CZ01069-08 | 22.0 ppb |
2016-02-09 | CZ01069-09 | 22.0 ppb |
2016-02-09 | CZ01069-10 | 20.0 ppb |
2016-02-09 | CZ01069-11 | 21.0 ppb |
2016-02-09 | CZ01069-12 | 23.0 ppb |
2016-02-09 | CZ01069-13 | 21.0 ppb |
2016-02-09 | CZ01069-14 | 22.0 ppb |
2016-05-11 | CZ05502-02 | 35.0 ppb |
2016-05-11 | CZ05502-03 | 29.0 ppb |
2016-05-11 | CZ05502-04 | 37.0 ppb |
2016-05-11 | CZ05502-05 | 34.0 ppb |
2016-05-11 | CZ05502-06 | 30.0 ppb |
2016-05-11 | CZ05502-07 | 37.0 ppb |
2016-05-11 | CZ05502-09 | 32.0 ppb |
2016-05-11 | CZ05502-10 | 34.0 ppb |
2016-05-11 | CZ05502-11 | 36.0 ppb |
2016-05-11 | CZ05502-12 | 26.0 ppb |
2016-05-11 | CZ05502-13 | 25.0 ppb |
2016-05-11 | CZ05502-14 | 37.0 ppb |
2016-08-09 | CZ10772-03 | 55.0 ppb |
2016-08-09 | CZ10772-04 | 57.0 ppb |
2016-08-09 | CZ10772-05 | 56.0 ppb |
2016-08-09 | CZ10772-06 | 51.0 ppb |
2016-08-09 | CZ10772-07 | 55.0 ppb |
2016-08-09 | CZ10772-08 | 54.0 ppb |
2016-08-09 | CZ10772-09 | 54.0 ppb |
2016-08-09 | CZ10772-10 | 50.0 ppb |
2016-08-09 | CZ10772-11 | 57.0 ppb |
2016-08-09 | CZ10772-12 | 51.0 ppb |
2016-08-09 | CZ10772-13 | 48.0 ppb |
2016-08-09 | CZ10772-14 | 53.0 ppb |
2016-11-08 | CZ16179-03 | 36.0 ppb |
2016-11-09 | CZ16179-04 | 41.0 ppb |
2016-11-09 | CZ16179-05 | 41.0 ppb |
2016-11-09 | CZ16179-06 | 39.0 ppb |
2016-11-09 | CZ16179-07 | 40.0 ppb |
2016-11-09 | CZ16179-08 | 39.0 ppb |
2016-11-09 | CZ16179-09 | 36.0 ppb |
2016-11-09 | CZ16179-10 | 46.0 ppb |
2016-11-09 | CZ16179-11 | 36.0 ppb |
2016-11-09 | CZ16179-12 | 41.0 ppb |
2016-11-09 | CZ16179-13 | 48.0 ppb |
2016-11-09 | CZ16179-14 | 41.0 ppb |
2017-02-15 | CA00946-03 | 29.0 ppb |
2017-02-15 | CA00946-04 | 28.0 ppb |
2017-02-15 | CA00946-05 | 28.0 ppb |
2017-02-15 | CA00946-06 | 30.0 ppb |
2017-02-15 | CA00946-07 | 29.0 ppb |
2017-02-15 | CA00946-08 | 34.0 ppb |
2017-02-15 | CA00946-09 | 37.0 ppb |
2017-02-15 | CA00946-10 | 40.0 ppb |
2017-02-15 | CA00946-11 | 31.0 ppb |
2017-02-15 | CA00946-12 | 41.0 ppb |
2017-02-15 | CA00946-13 | 40.0 ppb |
2017-02-15 | CA00946-14 | 37.0 ppb |
2017-05-08 | CA06171-03 | 46.0 ppb |
2017-05-08 | CA06171-04 | 47.0 ppb |
2017-05-08 | CA06171-05 | 49.0 ppb |
2017-05-08 | CA06171-06 | 42.0 ppb |
2017-05-08 | CA06171-07 | 48.0 ppb |
2017-05-08 | CA06171-08 | 51.0 ppb |
2017-05-08 | CA06171-09 | 46.0 ppb |
2017-05-08 | CA06171-10 | 38.0 ppb |
2017-05-08 | CA06171-11 | 40.0 ppb |
2017-05-08 | CA06171-12 | 48.0 ppb |
2017-05-08 | CA06171-13 | 37.0 ppb |
2017-05-08 | CA06171-14 | 47.0 ppb |
2017-08-08 | CA11368-03 | 53.0 ppb |
2017-08-08 | CA11368-04 | 55.0 ppb |
2017-08-08 | CA11368-05 | 53.0 ppb |
2017-08-08 | CA11368-06 | 55.0 ppb |
2017-08-08 | CA11368-07 | 55.0 ppb |
2017-08-08 | CA11368-08 | 56.0 ppb |
2017-08-08 | CA11368-09 | 52.0 ppb |
2017-08-08 | CA11368-10 | 53.0 ppb |
2017-08-08 | CA11368-11 | 55.0 ppb |
2017-08-08 | CA11368-12 | 55.0 ppb |
2017-08-08 | CA11368-13 | 52.0 ppb |
2017-08-08 | CA11368-14 | 55.0 ppb |
2017-11-14 | CA16981-03 | 38.0 ppb |
2017-11-14 | CA16981-04 | 8.20 ppb |
2017-11-14 | CA16981-05 | 8.30 ppb |
2017-11-14 | CA16981-06 | 38.0 ppb |
2017-11-14 | CA16981-07 | 39.0 ppb |
2017-11-14 | CA16981-08 | 38.0 ppb |
2017-11-14 | CA16981-09 | 38.0 ppb |
2017-11-14 | CA16981-10 | 38.0 ppb |
2017-11-14 | CA16981-11 | 42.0 ppb |
2017-11-14 | CA16981-12 | 37.0 ppb |
2017-11-14 | CA16981-13 | 38.0 ppb |
2017-11-14 | CA16981-14 | 37.0 ppb |
2018-02-13 | CB01007-03 | 37.0 ppb |
2018-02-13 | CB01007-04 | 36.0 ppb |
2018-02-13 | CB01007-05 | 34.0 ppb |
2018-02-13 | CB01007-06 | 36.0 ppb |
2018-02-13 | CB01007-07 | 36.0 ppb |
2018-02-13 | CB01007-08 | 36.0 ppb |
2018-02-13 | CB01007-09 | 35.0 ppb |
2018-02-13 | CB01007-10 | 35.0 ppb |
2018-02-13 | CB01007-11 | 37.0 ppb |
2018-02-13 | CB01007-12 | 36.0 ppb |
2018-02-13 | CB01007-13 | 36.0 ppb |
2018-02-13 | CB01007-14 | 35.0 ppb |
2018-05-08 | CB06320-03 | 46.0 ppb |
2018-05-08 | CB06320-04 | 48.0 ppb |
2018-05-08 | CB06320-05 | 41.0 ppb |
2018-05-08 | CB06320-06 | 44.0 ppb |
2018-05-08 | CB06320-07 | 46.0 ppb |
2018-05-08 | CB06320-08 | 47.0 ppb |
2018-05-08 | CB06320-09 | 45.0 ppb |
2018-05-08 | CB06320-10 | 45.0 ppb |
2018-05-08 | CB06320-11 | 47.0 ppb |
2018-05-08 | CB06320-12 | 45.0 ppb |
2018-05-08 | CB06320-13 | 15.0 ppb |
2018-05-08 | CB06320-14 | 47.0 ppb |
2018-08-14 | CB11155-03 | 67.0 ppb |
2018-08-14 | CB11155-04 | 68.0 ppb |
2018-08-14 | CB11155-05 | 63.0 ppb |
2018-08-14 | CB11155-06 | 67.0 ppb |
2018-08-14 | CB11155-07 | 72.0 ppb |
2018-08-14 | CB11155-08 | 76.0 ppb |
2018-08-14 | CB11155-09 | 71.0 ppb |
2018-08-14 | CB11155-10RE1 | 47.0 ppb |
2018-08-14 | CB11155-11RE1 | 68.0 ppb |
2018-08-14 | CB11155-12 | 70.0 ppb |
2018-08-14 | CB11155-13 | 46.0 ppb |
2018-08-14 | CB11155-14 | 68.0 ppb |
2018-11-12 | CB16648-03 | 44.0 ppb |
2018-11-12 | CB16648-04 | 42.0 ppb |
2018-11-12 | CB16648-05 | 39.0 ppb |
2018-11-12 | CB16648-06 | 35.0 ppb |
2018-11-12 | CB16648-07 | 33.0 ppb |
2018-11-12 | CB16648-08 | 45.0 ppb |
2018-11-12 | CB16648-09 | 45.0 ppb |
2018-11-12 | CB16648-10 | 30.0 ppb |
2018-11-12 | CB16648-11 | 46.0 ppb |
2018-11-12 | CB16648-12 | 47.0 ppb |
2018-11-12 | CB16648-13 | 28.0 ppb |
2018-11-12 | CB16648-14 | 44.0 ppb |
2019-02-12 | CC01716-03RE1 | 24.0 ppb |
2019-02-12 | CC01716-04 | 4.40 ppb |
2019-02-12 | CC01716-05 | 4.80 ppb |
2019-02-12 | CC01716-06 | 17.0 ppb |
2019-02-12 | CC01716-07 | 20.0 ppb |
2019-02-12 | CC01716-08RE1 | 22.0 ppb |
2019-02-12 | CC01716-09 | 20.0 ppb |
2019-02-12 | CC01716-10RE1 | 19.0 ppb |
2019-02-12 | CC01716-11 | 18.0 ppb |
2019-02-12 | CC01716-12 | 19.0 ppb |
2019-02-12 | CC01716-13 | 16.0 ppb |
2019-02-12 | CC01716-14 | 18.0 ppb |
2019-05-14 | CC06563-03 | 33.0 ppb |
2019-05-14 | CC06563-04 | 38.0 ppb |
2019-05-14 | CC06563-05 | 37.0 ppb |
2019-05-14 | CC06563-06 | 38.0 ppb |
2019-05-14 | CC06563-07 | 39.0 ppb |
2019-05-14 | CC06563-08 | 38.0 ppb |
2019-05-14 | CC06563-09 | 37.0 ppb |
2019-05-14 | CC06563-10 | 38.0 ppb |
2019-05-14 | CC06563-11 | 36.0 ppb |
2019-05-14 | CC06563-12 | 35.0 ppb |
2019-05-14 | CC06563-13 | 36.0 ppb |
2019-05-14 | CC06563-14 | 35.0 ppb |
2019-08-13 | CC12767-03 | 38.0 ppb |
2019-08-13 | CC12767-04 | 37.0 ppb |
2019-08-13 | CC12767-05 | 34.0 ppb |
2019-08-13 | CC12767-06 | 34.0 ppb |
2019-08-13 | CC12767-07 | 36.0 ppb |
2019-08-13 | CC12767-08 | 40.0 ppb |
2019-08-13 | CC12767-09 | 38.0 ppb |
2019-08-13 | CC12767-10 | 35.0 ppb |
2019-08-13 | CC12767-11 | 38.0 ppb |
2019-08-13 | CC12767-12 | 37.0 ppb |
2019-08-13 | CC12767-13 | 35.0 ppb |
2019-08-13 | CC12767-14 | 40.0 ppb |
2019-11-12 | CC18484-03 | 29.0 ppb |
2019-11-12 | CC18484-04 | 24.0 ppb |
2019-11-12 | CC18484-05 | 28.0 ppb |
2019-11-12 | CC18484-06 | 26.0 ppb |
2019-11-12 | CC18484-07 | 28.0 ppb |
2019-11-12 | CC18484-08 | 30.0 ppb |
2019-11-12 | CC18484-09 | 30.0 ppb |
2019-11-12 | CC18484-10 | 28.0 ppb |
2019-11-12 | CC18484-11 | 28.0 ppb |
2019-11-12 | CC18484-12 | 27.0 ppb |
2019-11-12 | CC18484-13 | 25.0 ppb |
2019-11-12 | CC18484-14 | 25.0 ppb |