Know Your Environment. Protect Your Health.

Total trihalomethanes (TTHMs)

Myoma Dunes Mutual Water Company

Trihalomethanes are cancer-causing contaminants that form during water treatment with chlorine and other disinfectants. The total trihalomethanes group includes four chemicals: chloroform, bromodichloromethane, dibromochloromethane and bromoform. Read More.

Studies conducted in the U.S. and Europe have found that drinking tap water that carries disinfection byproducts increases the risk of developing bladder cancer. In animal studies, all trihalomethanes cause liver, kidney and intestinal tumors. Some human epidemiological studies also reported an association between disinfection byproducts and an increased risk of problems during pregnancy, including spontaneous miscarriage, cardiovascular defects, neural tube defects and low birth weight.

The health guideline of 0.15 parts per billion, or ppb, for the group of four trihalomethanes, or THM4/TTHM, was defined in a peer-reviewed scientific study by EWG and represents a one-in-one-million lifetime cancer risk level.

Click here to read more about disinfection byproducts.

 

48

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018ND80ND
2019ND80ND
2020ND80ND
2021ND80ND
2022ND80ND
2023ND80ND

ppb = parts per billion

State, National, and Health Guidelines for Drinking Water

EWG Health Guideline: 0.15 ppb

The health guideline of 0.15 parts per billion, or ppb, for the group of four trihalomethanes, or THM4/TTHM, was defined in a peer-reviewed scientific study by EWG and represents a one-in-one-million lifetime cancer risk level.

EPA Maximum Contaminant
Level (MCL): 80 ppb

The legal limit for the group of four trihalomethanes, established in 1998, was based on the need for residual disinfectant levels in water served to customers and the cost of treatment. This limit does not fully protect against the risk of cancer due to exposure to trihalomethanes.

ppb = parts per billion

All test results

Date Lab ID Result
2018-02-21CA3310051_DST_802-201802210911ND
2018-02-21CA3310051_DST_801-201802210847ND
2018-05-21CA3310051_DST_801-201805210818ND
2018-05-21CA3310051_DST_802-201805210840ND
2018-08-20CA3310051_DST_802-201808201010ND
2018-08-20CA3310051_DST_801-201808200945ND
2018-11-19CA3310051_DST_802-201811190914ND
2018-11-19CA3310051_DST_801-201811190855ND
2019-02-21CA3310051_DST_801-201902210953ND
2019-02-21CA3310051_DST_802-201902210848ND
2019-05-20CA3310051_DST_801-201905200013ND
2019-05-20CA3310051_DST_802-201905200925ND
2019-08-26CA3310051_DST_801-201908260940ND
2019-08-26CA3310051_DST_802-201908260920ND
2019-11-22CA3310051_DST_802-201911220817ND
2019-11-22CA3310051_DST_801-201911220844ND
2020-02-24CA3310051_DST_802-202002240830ND
2020-02-24CA3310051_DST_801-202002240758ND
2020-05-18CA3310051_DST_802-202005181031ND
2020-05-18CA3310051_DST_801-202005181016ND
2020-08-24CA3310051_DST_801-202008241026ND
2020-08-24CA3310051_DST_802-202008240927ND
2020-11-16CA3310051_DST_801-202011161030ND
2020-11-16CA3310051_DST_802-202011161000ND
2021-02-16CA3310051_DST_801-202102161050ND
2021-02-16CA3310051_DST_802-202102161030ND
2021-05-03CA3310051_DST_801-202105031008ND
2021-05-03CA3310051_DST_802-202105030938ND
2021-08-23CA3310051_DST_801-202108231040ND
2021-08-23CA3310051_DST_802-202108231020ND
2021-11-10CA3310051_DST_802-202111101355ND
2021-11-10CA3310051_DST_801-202111101325ND
2022-02-28CA3310051_DST_802-202202280835ND
2022-02-28CA3310051_DST_801-202202280856ND
2022-06-14CA3310051_DST_801-202206140840ND
2022-06-14CA3310051_DST_802-202206140900ND
2022-08-09CA3310051_DST_802-202208091114ND
2022-08-09CA3310051_DST_801-202208091048ND
2022-12-22CA3310051_DST_802-202212220840ND
2022-12-22CA3310051_DST_801-202212220815ND
2023-03-14CA3310051_DST_801-202303141110ND
2023-03-14CA3310051_DST_802-202303141120ND
2023-06-13CA3310051_DST_802-202306130847ND
2023-06-13CA3310051_DST_801-202306130927ND
2023-08-22CA3310051_DST_801-202308220932ND
2023-08-22CA3310051_DST_802-202308220823ND
2023-12-12CA3310051_DST_801-202312120903ND
2023-12-12CA3310051_DST_802-202312120920ND