Chloroform
Cotuit Fire District Water Department
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.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2014 | 0.704 ppb | 5 | 5 | 0.510 ppb - 1.20 ppb |
| 2015 | 0.752 ppb | 21 | 20 | ND - 1.10 ppb |
| 2016 | 0.569 ppb | 7 | 6 | ND - 0.820 ppb |
| 2017 | 0.432 ppb | 6 | 4 | ND - 0.750 ppb |
| 2018 | 0.956 ppb | 7 | 6 | ND - 3.50 ppb |
| 2019 | 0.843 ppb | 7 | 7 | 0.510 ppb - 1.80 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 | Result |
|---|---|
| 2014-02-18 | 0.620 ppb |
| 2014-02-18 | 0.630 ppb |
| 2014-02-18 | 0.510 ppb |
| 2014-02-18 | 1.20 ppb |
| 2014-02-18 | 0.560 ppb |
| 2015-01-05 | ND |
| 2015-01-05 | 0.680 ppb |
| 2015-01-05 | 0.520 ppb |
| 2015-01-05 | 0.690 ppb |
| 2015-01-05 | 0.740 ppb |
| 2015-02-11 | 0.900 ppb |
| 2015-02-11 | 0.990 ppb |
| 2015-02-11 | 0.960 ppb |
| 2015-02-11 | 0.890 ppb |
| 2015-05-11 | 0.920 ppb |
| 2015-05-11 | 0.940 ppb |
| 2015-05-11 | 1.10 ppb |
| 2015-05-11 | 0.900 ppb |
| 2015-08-10 | 0.660 ppb |
| 2015-08-10 | 0.710 ppb |
| 2015-08-10 | 0.770 ppb |
| 2015-08-10 | 0.660 ppb |
| 2015-11-09 | 0.680 ppb |
| 2015-11-09 | 0.760 ppb |
| 2015-11-09 | 0.620 ppb |
| 2015-11-09 | 0.700 ppb |
| 2016-02-01 | 0.590 ppb |
| 2016-02-01 | 0.820 ppb |
| 2016-02-01 | ND |
| 2016-02-01 | 0.590 ppb |
| 2016-02-01 | 0.640 ppb |
| 2016-08-08 | 0.710 ppb |
| 2016-08-08 | 0.630 ppb |
| 2017-02-21 | 0.520 ppb |
| 2017-02-21 | ND |
| 2017-02-21 | ND |
| 2017-02-21 | 0.750 ppb |
| 2017-02-21 | 0.660 ppb |
| 2017-08-07 | 0.660 ppb |
| 2018-02-05 | 3.50 ppb |
| 2018-02-05 | 0.750 ppb |
| 2018-02-05 | ND |
| 2018-02-05 | 0.560 ppb |
| 2018-02-05 | 0.620 ppb |
| 2018-08-06 | 0.690 ppb |
| 2018-08-06 | 0.570 ppb |
| 2019-02-22 | 0.570 ppb |
| 2019-02-22 | 0.940 ppb |
| 2019-02-22 | 0.730 ppb |
| 2019-02-22 | 0.510 ppb |
| 2019-02-22 | 0.560 ppb |
| 2019-08-13 | 1.80 ppb |
| 2019-08-13 | 0.790 ppb |