Know Your Environment. Protect Your Health.

Total trihalomethanes (TTHMs)

Middletown Water Department

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

9

Samples exceeding legal limit (MCL)

96

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
201854.5 ppb161627.8 ppb - 88.8 ppb
201954.7 ppb161633.6 ppb - 86.3 ppb
202047.2 ppb161624.0 ppb - 89.2 ppb
202150.0 ppb161621.2 ppb - 103.1 ppb
202242.9 ppb161626.1 ppb - 73.4 ppb
202349.4 ppb161625.3 ppb - 103.7 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
2018-01-05DBP 20048541132.5 ppb
2018-01-05DBP 20048541262.0 ppb
2018-01-05DBP 20048541335.8 ppb
2018-01-05DBP 20048541027.8 ppb
2018-04-05DBP 20049144637.1 ppb
2018-04-05DBP 20049144735.0 ppb
2018-04-05DBP 20049144838.5 ppb
2018-04-05DBP 20049144935.8 ppb
2018-07-04DBP 20049863869.4 ppb
2018-07-04DBP 20049863962.6 ppb
2018-07-04DBP 20049864074.3 ppb
2018-07-04DBP 20049864188.8 ppb
2018-10-04DBP 20050804862.3 ppb
2018-10-04DBP 20050805072.6 ppb
2018-10-04DBP 20050804974.3 ppb
2018-10-04DBP 20050804763.3 ppb
2019-01-03DBP 20051750633.6 ppb
2019-01-03DBP 20051750736.4 ppb
2019-01-03DBP 20051750867.6 ppb
2019-01-03DBP 20051750939.9 ppb
2019-04-04DBP 20052718245.5 ppb
2019-04-04DBP 20052718343.0 ppb
2019-04-04DBP 20052718452.3 ppb
2019-04-04DBP 20052718553.5 ppb
2019-07-03DBP 20053892363.1 ppb
2019-07-03DBP 20053892584.3 ppb
2019-07-03DBP 20053892482.3 ppb
2019-07-03DBP 20053892286.3 ppb
2019-10-17DBP 20055333549.2 ppb
2019-10-17DBP 20055333749.7 ppb
2019-10-17DBP 20055333951.5 ppb
2019-10-17DBP 20055333337.5 ppb
2020-01-09DBP 20056231324.0 ppb
2020-01-09DBP 20056231426.8 ppb
2020-01-09DBP 20056231533.0 ppb
2020-01-09DBP 20056231628.8 ppb
2020-04-09DBP 20057189641.9 ppb
2020-04-09DBP 20057189745.9 ppb
2020-04-09DBP 20057189547.1 ppb
2020-04-09DBP 20057189347.1 ppb
2020-07-09DBP 20058208468.6 ppb
2020-07-09DBP 20058208561.5 ppb
2020-07-09DBP 20058208666.5 ppb
2020-07-09DBP 20058208789.2 ppb
2020-10-15DBP 20059416740.4 ppb
2020-10-15DBP 20059416839.3 ppb
2020-10-15DBP 20059416944.4 ppb
2020-10-15DBP 20059417050.1 ppb
2021-01-14DBP 20060390230.1 ppb
2021-01-14DBP 20060389931.6 ppb
2021-01-14DBP 20060390028.0 ppb
2021-01-14DBP 20060390121.2 ppb
2021-04-15DBP 20061333829.1 ppb
2021-04-15DBP 20061333928.0 ppb
2021-04-15DBP 20061334039.6 ppb
2021-04-15DBP 20061333740.9 ppb
2021-07-08DBP 20062369163.0 ppb
2021-07-08DBP 20062369363.7 ppb
2021-07-08DBP 20062370863.0 ppb
2021-07-08DBP 20062370985.7 ppb
2021-10-21B300086252 30008625455.4 ppb
2021-10-21B300086249 300086251103.1 ppb
2021-10-21B300086246 30008624871.9 ppb
2021-10-21B300086243 30008624545.5 ppb
2022-01-06D300128620 30012862238.5 ppb
2022-01-06D300128623 30012862533.8 ppb
2022-01-06D300128626 30012862840.5 ppb
2022-01-06D300128629 30012863134.3 ppb
2022-04-07D300167654 30016765632.7 ppb
2022-04-07D300167657 30016765927.6 ppb
2022-04-07D300167660 30016766232.2 ppb
2022-04-07D300167663 30016766526.1 ppb
2022-07-07D300209440 30020944263.7 ppb
2022-07-07D300209434 30020943656.9 ppb
2022-07-07D300209431 30020943360.9 ppb
2022-07-07D300209437 30020943973.4 ppb
2022-10-27D300264516 30026451846.3 ppb
2022-10-27D300264519 30026452134.8 ppb
2022-10-27D300264522 30026452453.9 ppb
2022-10-27D300264525 30026452731.0 ppb
2023-01-12D300297210 30029721230.7 ppb
2023-01-12D300297213 30029721525.3 ppb
2023-01-12D300297216 30029721834.0 ppb
2023-01-12D300297219 30029722134.2 ppb
2023-04-20D300336742 30033674437.6 ppb
2023-04-20D300336748 30033675054.9 ppb
2023-04-20D300336745 30033674746.1 ppb
2023-04-20D300336739 30033674143.0 ppb
2023-07-06D300377098 30037710076.3 ppb
2023-07-06D300377101 30037710381.4 ppb
2023-07-06D300377104 300377106103.7 ppb
2023-07-06D300377107 30037710971.3 ppb
2023-10-19D300433229 30043323136.7 ppb
2023-10-19D300433232 30043323433.4 ppb
2023-10-19D300433235 30043323751.8 ppb
2023-10-19D300433238 30043324030.7 ppb