Chloroform
Gallup Water System
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 |
|---|---|---|---|---|
| 2013 | N/A | 0 | 0 | N/A |
| 2014 | 0.953 ppb | 16 | 16 | 0.410 ppb - 1.80 ppb |
| 2015 | 0.929 ppb | 16 | 16 | 0.180 ppb - 2.20 ppb |
| 2016 | 1.20 ppb | 16 | 16 | 0.540 ppb - 3.10 ppb |
| 2017 | 1.16 ppb | 16 | 16 | 0.430 ppb - 2.70 ppb |
| 2018 | 0.941 ppb | 16 | 15 | ND - 2.20 ppb |
| 2019 | 2.34 ppb | 16 | 15 | ND - 13.0 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 |
|---|---|---|
| 2014-01-24 | 2014002444 | 1.30 ppb |
| 2014-01-24 | 2014002446 | 1.000 ppb |
| 2014-01-24 | 2014002445 | 0.440 ppb |
| 2014-01-24 | 2014002443 | 1.70 ppb |
| 2014-04-16 | 2014012563 | 1.80 ppb |
| 2014-04-16 | 2014012562 | 1.20 ppb |
| 2014-04-16 | 2014012564 | 0.610 ppb |
| 2014-04-16 | 2014012561 | 0.410 ppb |
| 2014-07-01 | 2014020830 | 1.30 ppb |
| 2014-07-01 | 2014020833 | 0.670 ppb |
| 2014-07-01 | 2014020832 | 0.570 ppb |
| 2014-07-01 | 2014020831 | 0.540 ppb |
| 2014-11-19 | 2014035737 | 1.000 ppb |
| 2014-11-19 | 2014035739 | 0.420 ppb |
| 2014-11-19 | 2014035740 | 0.890 ppb |
| 2014-11-19 | 2014035738 | 1.40 ppb |
| 2015-02-04 | 2015003904 | 1.40 ppb |
| 2015-02-04 | 2015003903 | 1.20 ppb |
| 2015-02-04 | 2015003902 | 0.810 ppb |
| 2015-02-04 | 2015003901 | 0.480 ppb |
| 2015-04-08 | 2015010918 | 0.840 ppb |
| 2015-04-08 | 2015010917 | 0.750 ppb |
| 2015-04-08 | 2015010916 | 0.480 ppb |
| 2015-04-08 | 2015010915 | 0.290 ppb |
| 2015-08-18 | 2015023952 | 0.860 ppb |
| 2015-08-18 | 2015023951 | 0.680 ppb |
| 2015-08-18 | 2015023950 | 0.820 ppb |
| 2015-08-18 | 2015023949 | 1.70 ppb |
| 2015-11-30 | 2015035105 | 1.40 ppb |
| 2015-11-30 | 2015035104 | 0.780 ppb |
| 2015-11-30 | 2015035102 | 0.180 ppb |
| 2015-11-30 | 2015035103 | 2.20 ppb |
| 2016-02-24 | 2016005290 | 1.80 ppb |
| 2016-02-24 | 2016005291 | 0.800 ppb |
| 2016-02-24 | 2016005288 | 0.740 ppb |
| 2016-02-24 | 2016005289 | 0.540 ppb |
| 2016-04-12 | 2016010325 | 0.790 ppb |
| 2016-04-12 | 2016010326 | 0.600 ppb |
| 2016-04-12 | 2016010324 | 0.960 ppb |
| 2016-04-12 | 2016010327 | 1.50 ppb |
| 2016-07-19 | 2016020564 | 1.40 ppb |
| 2016-07-19 | 2016020565 | 1.30 ppb |
| 2016-07-19 | 2016020566 | 0.780 ppb |
| 2016-07-19 | 2016020563 | 0.660 ppb |
| 2016-10-25 | 2016031001 | 3.10 ppb |
| 2016-10-25 | 2016030998 | 2.20 ppb |
| 2016-10-25 | 2016030999 | 1.20 ppb |
| 2016-10-25 | 2016031000 | 0.850 ppb |
| 2017-01-10 | 2017000731 | 1.20 ppb |
| 2017-01-10 | 2017000729 | 1.80 ppb |
| 2017-01-10 | 2017000732 | 1.50 ppb |
| 2017-01-10 | 2017000730 | 1.20 ppb |
| 2017-04-04 | 2017009635 | 1.60 ppb |
| 2017-04-04 | 2017009636 | 1.000 ppb |
| 2017-04-04 | 2017009638 | 0.850 ppb |
| 2017-04-04 | 2017009637 | 0.500 ppb |
| 2017-07-05 | 2017019172 | 0.680 ppb |
| 2017-07-05 | 2017019171 | 0.940 ppb |
| 2017-07-05 | 2017019174 | 0.950 ppb |
| 2017-07-05 | 2017019173 | 1.70 ppb |
| 2017-10-11 | 2017029274 | 2.70 ppb |
| 2017-10-11 | 2017029275 | 0.980 ppb |
| 2017-10-11 | 2017029277 | 0.500 ppb |
| 2017-10-11 | 2017029276 | 0.430 ppb |
| 2018-01-10 | 2018000973 | 0.360 ppb |
| 2018-01-10 | 2018000972 | 2.20 ppb |
| 2018-01-10 | 2018000971 | ND |
| 2018-01-10 | 2018000970 | 1.20 ppb |
| 2018-04-11 | 2018010264 | 0.650 ppb |
| 2018-04-11 | 2018010261 | 0.440 ppb |
| 2018-04-11 | 2018010262 | 1.20 ppb |
| 2018-04-11 | 2018010263 | 0.600 ppb |
| 2018-07-10 | 2018018728 | 0.650 ppb |
| 2018-07-10 | 2018018727 | 0.780 ppb |
| 2018-07-10 | 2018018726 | 1.30 ppb |
| 2018-07-10 | 2018018725 | 0.840 ppb |
| 2018-10-04 | 2018028465 | 1.10 ppb |
| 2018-10-04 | 2018028466 | 1.10 ppb |
| 2018-10-04 | 2018028467 | 0.740 ppb |
| 2018-10-04 | 2018028468 | 1.90 ppb |
| 2019-01-10 | 2019000748 | ND |
| 2019-01-10 | 2019000749 | 1.60 ppb |
| 2019-01-10 | 2019000750 | 13.0 ppb |
| 2019-01-10 | 2019000751 | 1.20 ppb |
| 2019-04-09 | 2019008900 | 1.30 ppb |
| 2019-04-09 | 2019008903 | 3.40 ppb |
| 2019-04-09 | 2019008902 | 1.90 ppb |
| 2019-04-09 | 2019008901 | 0.930 ppb |
| 2019-07-09 | 2019018732 | 1.80 ppb |
| 2019-07-09 | 2019018734 | 1.10 ppb |
| 2019-07-09 | 2019018733 | 1.20 ppb |
| 2019-07-09 | 2019018731 | 1.10 ppb |
| 2019-10-10 | 2019029113 | 3.40 ppb |
| 2019-10-10 | 2019029112 | 2.40 ppb |
| 2019-10-10 | 2019029111 | 1.000 ppb |
| 2019-10-10 | 2019029110 | 2.10 ppb |