Know Your Environment. Protect Your Health.

Chloroform

South Grafton Water 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.

 

53

Samples

0

Samples exceeding legal limit (MCL)

43

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.998 ppb440.690 ppb - 1.30 ppb
20192.20 ppb330.700 ppb - 5.10 ppb
20202.13 ppb32ND - 4.00 ppb
20213.42 ppb550.810 ppb - 7.00 ppb
20221.92 ppb109ND - 6.30 ppb
20232.21 ppb2820ND - 8.10 ppb

ppb = parts per billion

State, National, and Health Guidelines for Drinking Water

EWG Health Guideline: 0.4 ppb

The EWG Health Guideline of 0.4 ppb for chloroform was based on the California Office of Environmental Health Hazard Assessment's public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cancer and harm to fetal growth and development.

ppb = parts per billion

All test results

Date Result
2018-01-081.30 ppb
2018-02-051.30 ppb
2018-03-050.700 ppb
2018-04-020.690 ppb
2019-05-060.700 ppb
2019-08-050.790 ppb
2019-11-045.10 ppb
2020-05-042.40 ppb
2020-08-034.00 ppb
2020-11-02ND
2021-02-011.10 ppb
2021-05-100.810 ppb
2021-05-102.50 ppb
2021-08-025.70 ppb
2021-11-017.00 ppb
2022-02-071.40 ppb
2022-05-025.50 ppb
2022-06-050.880 ppb
2022-07-050.960 ppb
2022-08-011.000 ppb
2022-08-011.90 ppb
2022-09-060.740 ppb
2022-10-030.560 ppb
2022-11-07ND
2022-11-076.30 ppb
2023-02-064.10 ppb
2023-02-062.60 ppb
2023-02-06ND
2023-02-06ND
2023-03-06ND
2023-03-06ND
2023-04-03ND
2023-04-03ND
2023-05-010.500 ppb
2023-05-012.10 ppb
2023-05-010.500 ppb
2023-05-015.40 ppb
2023-05-010.600 ppb
2023-06-121.10 ppb
2023-06-121.10 ppb
2023-07-10ND
2023-07-10ND
2023-08-076.00 ppb
2023-08-072.80 ppb
2023-08-072.80 ppb
2023-08-072.20 ppb
2023-09-053.40 ppb
2023-09-053.40 ppb
2023-10-021.80 ppb
2023-11-063.00 ppb
2023-11-068.10 ppb
2023-11-068.10 ppb
2023-12-042.30 ppb