Know Your Environment. Protect Your Health.

Total trihalomethanes (TTHMs)

Moorhead

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.

 

96

Samples

0

Samples exceeding legal limit (MCL)

58

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.719 ppb1611ND - 2.00 ppb
20190.150 ppb164ND - 0.600 ppb
20200.275 ppb167ND - 1.000 ppb
20210.163 ppb164ND - 1.10 ppb
20220.975 ppb16160.500 ppb - 1.90 ppb
20231.73 ppb16160.800 ppb - 3.60 ppb

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
2018-03-0618C0215-021.30 ppb
2018-03-0618C0215-031.80 ppb
2018-03-0618C0215-042.00 ppb
2018-03-0618C0215-011.80 ppb
2018-06-0518F0299-010.600 ppb
2018-06-0518F0299-02ND
2018-06-0518F0299-030.600 ppb
2018-06-0518F0299-040.600 ppb
2018-09-1118I0493-010.700 ppb
2018-09-1118I0493-020.700 ppb
2018-09-1118I0493-030.700 ppb
2018-09-1118I0493-040.700 ppb
2018-12-0518L0242-02ND
2018-12-0518L0242-04ND
2018-12-0518L0242-03ND
2018-12-0518L0242-01ND
2019-03-1119C0476-01ND
2019-03-1119C0476-02ND
2019-03-1119C0476-03ND
2019-03-1119C0476-04ND
2019-06-0519F0336-01ND
2019-06-0519F0336-02ND
2019-06-0519F0336-03ND
2019-06-0519F0336-04ND
2019-09-0919I0419-020.600 ppb
2019-09-0919I0419-040.600 ppb
2019-09-0919I0419-030.600 ppb
2019-09-0919I0419-010.600 ppb
2019-12-1619L0991-02ND
2019-12-1619L0991-03ND
2019-12-1619L0991-04ND
2019-12-1619L0991-01ND
2020-03-1620C0769-010.500 ppb
2020-03-1620C0769-021.000 ppb
2020-03-1620C0769-030.600 ppb
2020-03-1620C0769-040.700 ppb
2020-06-0320F0318-030.500 ppb
2020-06-0320F0318-04ND
2020-06-0320F0318-02ND
2020-06-0320F0318-010.600 ppb
2020-09-0220I0274-01ND
2020-09-0220I0274-020.500 ppb
2020-09-0220I0274-03ND
2020-09-0220I0274-04ND
2020-12-0920L0429-01ND
2020-12-0920L0429-02ND
2020-12-0920L0429-03ND
2020-12-0920L0429-04ND
2021-03-1521C0767-04ND
2021-03-1521C0767-01ND
2021-03-1521C0767-02ND
2021-03-1521C0767-03ND
2021-06-1621F1086-02ND
2021-06-2321F1494-010.500 ppb
2021-06-2321F1494-020.500 ppb
2021-06-2321F1494-030.500 ppb
2021-09-2121I1086-01ND
2021-09-2121I1086-02ND
2021-09-2121I1086-03ND
2021-09-2121I1086-04ND
2021-12-1421L0615-04ND
2021-12-1421L0615-031.10 ppb
2021-12-1421L0615-02ND
2021-12-1421L0615-01ND
2022-03-2122C0953-010.500 ppb
2022-03-2122C0953-021.50 ppb
2022-03-2122C0953-030.500 ppb
2022-03-2122C0953-041.20 ppb
2022-06-2122F1298-010.700 ppb
2022-06-2122F1298-020.700 ppb
2022-06-2122F1298-030.700 ppb
2022-06-2122F1298-040.600 ppb
2022-09-2022I1842-041.60 ppb
2022-09-2022I1842-020.700 ppb
2022-09-2022I1842-010.700 ppb
2022-09-2022I1842-030.900 ppb
2022-12-1322L0865-011.10 ppb
2022-12-1322L0865-021.20 ppb
2022-12-1322L0865-031.90 ppb
2022-12-1322L0865-041.10 ppb
2023-03-1323C0678-011.40 ppb
2023-03-1323C0678-021.30 ppb
2023-03-1323C0678-031.50 ppb
2023-03-1323C0678-041.20 ppb
2023-06-1323F1213-021.70 ppb
2023-06-1323F1213-043.40 ppb
2023-06-1323F1213-032.50 ppb
2023-06-1323F1213-013.60 ppb
2023-09-1123I0477-010.800 ppb
2023-09-1123I0477-020.900 ppb
2023-09-1123I0477-031.70 ppb
2023-09-1123I0477-040.900 ppb
2023-12-0423L0108-011.60 ppb
2023-12-0423L0108-021.000 ppb
2023-12-0423L0108-032.20 ppb
2023-12-0423L0108-041.90 ppb