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EWG's Tap Water Database — 2021 UPDATE

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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.

MORE ABOUT THIS CONTAMINANT

 

104

Samples

10

Samples exceeding legal limit (MCL)

104

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
201448.2 ppb242425.9 ppb - 84.7 ppb
201547.0 ppb161625.7 ppb - 73.1 ppb
201651.6 ppb161619.7 ppb - 85.9 ppb
201748.2 ppb161618.8 ppb - 89.5 ppb
201854.5 ppb161627.8 ppb - 88.8 ppb
201954.7 ppb161633.6 ppb - 86.3 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

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
2014-01-07DBP 20038899631.1 ppb
2014-01-07DBP 20038899725.9 ppb
2014-01-07DBP 20038899846.7 ppb
2014-01-07DBP 20038899934.6 ppb
2014-03-13DBP 20039266536.6 ppb
2014-03-13DBP 20039266635.1 ppb
2014-03-13DBP 20039266748.4 ppb
2014-03-13DBP 20039266839.3 ppb
2014-04-04DBP 20039370241.7 ppb
2014-04-04DBP 20039370335.8 ppb
2014-04-04DBP 20039370450.9 ppb
2014-04-04DBP 20039370540.8 ppb
2014-07-03DBP 20039899577.8 ppb
2014-07-03DBP 20039899647.4 ppb
2014-07-03DBP 20039899884.7 ppb
2014-07-03DBP 20039899983.5 ppb
2014-10-02DBP 20040538762.9 ppb
2014-10-02DBP 20040538850.7 ppb
2014-10-02DBP 20040538966.6 ppb
2014-10-02DBP 20040539070.8 ppb
2014-12-11DBP 20040945431.5 ppb
2014-12-11DBP 20040945531.3 ppb
2014-12-11DBP 20040945645.2 ppb
2014-12-11DBP 20040945737.8 ppb
2015-01-08DBP 20041040534.7 ppb
2015-01-08DBP 20041040325.7 ppb
2015-01-08DBP 20041040442.6 ppb
2015-01-08DBP 20041040230.5 ppb
2015-04-02DBP 20041437533.6 ppb
2015-04-02DBP 20041437330.5 ppb
2015-04-02DBP 20041437233.3 ppb
2015-04-02DBP 20041437435.2 ppb
2015-07-07DBP 20041966262.5 ppb
2015-07-07DBP 20041966047.2 ppb
2015-07-07DBP 20041965953.6 ppb
2015-07-07DBP 20041966164.4 ppb
2015-10-01DBP 20042594167.7 ppb
2015-10-01DBP 20042594073.1 ppb
2015-10-01DBP 20042593868.2 ppb
2015-10-01DBP 20042593948.5 ppb
2016-01-07DBP 20043158823.2 ppb
2016-01-07DBP 20043158919.7 ppb
2016-01-07DBP 20043159028.3 ppb
2016-01-07DBP 20043159130.0 ppb
2016-04-07DBP 20043684154.7 ppb
2016-04-07DBP 20043684237.8 ppb
2016-04-07DBP 20043684366.2 ppb
2016-04-07DBP 20043684467.0 ppb
2016-07-07DBP 20044403376.7 ppb
2016-07-07DBP 20044403458.0 ppb
2016-07-07DBP 20044403573.4 ppb
2016-07-07DBP 20044403685.9 ppb
2016-10-07DBP 20045191644.2 ppb
2016-10-07DBP 20045191739.4 ppb
2016-10-07DBP 20045191867.1 ppb
2016-10-07DBP 20045191954.3 ppb
2017-01-05DBP 20045819018.8 ppb
2017-01-05DBP 20045819119.2 ppb
2017-01-05DBP 20045819229.8 ppb
2017-01-05DBP 20045819323.7 ppb
2017-04-07DBP 20046408827.8 ppb
2017-04-07DBP 20046408929.4 ppb
2017-04-07DBP 20046409036.4 ppb
2017-04-07DBP 20046409134.5 ppb
2017-07-06DBP 20047128382.8 ppb
2017-07-06DBP 20047128464.7 ppb
2017-07-06DBP 20047128589.5 ppb
2017-07-06DBP 20047128689.0 ppb
2017-10-05DBP 20047879259.9 ppb
2017-10-05DBP 20047879343.9 ppb
2017-10-05DBP 20047879462.3 ppb
2017-10-05DBP 20047879560.1 ppb
2018-01-05DBP 20048541027.8 ppb
2018-01-05DBP 20048541132.5 ppb
2018-01-05DBP 20048541262.0 ppb
2018-01-05DBP 20048541335.8 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 20050804763.3 ppb
2018-10-04DBP 20050804862.3 ppb
2018-10-04DBP 20050804974.3 ppb
2018-10-04DBP 20050805072.6 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 20053892286.3 ppb
2019-07-03DBP 20053892363.1 ppb
2019-07-03DBP 20053892482.3 ppb
2019-07-03DBP 20053892584.3 ppb
2019-10-17DBP 20055333337.5 ppb
2019-10-17DBP 20055333549.2 ppb
2019-10-17DBP 20055333749.7 ppb
2019-10-17DBP 20055333951.5 ppb