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EWG's Tap Water Database — 2021 UPDATE

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Total trihalomethanes (TTHMs)

City of Emporia

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

 

96

Samples

0

Samples exceeding legal limit (MCL)

5

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND160ND
2015ND160ND
2016ND160ND
2017ND160ND
20180.969 ppb165ND - 4.90 ppb
2019ND160ND

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
2014-02-1762656ND
2014-02-1762654ND
2014-02-1762652ND
2014-02-1762650ND
2014-04-22100330ND
2014-04-22100329ND
2014-04-22100328ND
2014-04-22100327ND
2014-07-22156096ND
2014-07-22156095ND
2014-07-22156097ND
2014-07-22156098ND
2014-10-15214268ND
2014-10-15214267ND
2014-10-15214266ND
2014-10-15214265ND
2015-01-27267735ND
2015-01-27267734ND
2015-01-27267733ND
2015-01-27267732ND
2015-04-28319815ND
2015-04-28319816ND
2015-04-28319818ND
2015-04-28319817ND
2015-07-28374610ND
2015-07-28374609ND
2015-07-28374608ND
2015-07-28374607ND
2015-10-27418822ND
2015-10-27418821ND
2015-10-27418820ND
2015-10-27418819ND
2016-02-02484838ND
2016-02-02484837ND
2016-02-02484839ND
2016-02-02484840ND
2016-04-18529837ND
2016-04-18529836ND
2016-04-18529835ND
2016-04-18529834ND
2016-07-26590153ND
2016-07-26590152ND
2016-07-26590151ND
2016-07-26590150ND
2016-10-25647964ND
2016-10-25647967ND
2016-10-25647966ND
2016-10-25647965ND
2017-01-30678887ND
2017-01-30678886ND
2017-01-30678885ND
2017-01-30678884ND
2017-04-24746469ND
2017-04-24746468ND
2017-04-24746464ND
2017-04-24746463ND
2017-07-31807764ND
2017-07-31807763ND
2017-07-31807765ND
2017-07-31807766ND
2017-10-30868916ND
2017-10-30868915ND
2017-10-30868914ND
2017-10-30868913ND
2018-01-30906722ND
2018-01-30906721ND
2018-01-30906720ND
2018-01-30906719ND
2018-04-24937385ND
2018-04-24937386ND
2018-04-24937388ND
2018-04-24937387ND
2018-07-301014509ND
2018-07-3010145082.80 ppb
2018-07-3010145072.30 ppb
2018-07-3010145063.30 ppb
2018-11-131076980ND
2018-11-131076979ND
2018-11-1310769782.20 ppb
2018-11-1310769774.90 ppb
2019-01-281110888ND
2019-01-281110887ND
2019-01-281110889ND
2019-01-281110890ND
2019-04-291137812ND
2019-04-291137811ND
2019-04-291137810ND
2019-04-291137809ND
2019-08-201226680ND
2019-08-201226679ND
2019-08-201226678ND
2019-08-201226677ND
2019-10-291265810ND
2019-10-291265813ND
2019-10-291265812ND
2019-10-291265811ND