EWG's Tap Water Database — 2021 UPDATE



Dubuque Water Works

Bromoform, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Bromoform and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.





Samples exceeding legal limit (MCL)


Samples exceeding
health guidelines

Testing results - average by year

YearAverage resultSamples takenDetectionsRange of results
20140.650 ppb16160.500 ppb - 0.800 ppb
20151.05 ppb221.000 ppb - 1.10 ppb
20160.700 ppb220.700 ppb
20170.700 ppb220.700 ppb
20180.775 ppb440.600 ppb - 1.000 ppb
20190.250 ppb62ND - 0.900 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.5 ppb

The EWG Health Guideline of 0.5 ppb for bromoform was proposed in 2018 by the California Office of Environmental Health Hazard Assessment as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.

ppb = parts per billion

All test results

Date Lab ID Result
2014-02-1220342570.600 ppb
2014-02-1220344820.700 ppb
2014-02-1220344800.600 ppb
2014-02-1220344810.700 ppb
2014-05-1320521290.600 ppb
2014-05-1320521060.500 ppb
2014-05-1320529070.700 ppb
2014-05-1320529040.600 ppb
2014-08-0620714740.600 ppb
2014-08-0620714750.800 ppb
2014-08-0620714770.800 ppb
2014-08-0620710490.800 ppb
2014-11-0420906410.600 ppb
2014-11-0420906430.600 ppb
2014-11-0420906440.600 ppb
2014-11-0420906450.600 ppb
2015-08-13OE2805561.000 ppb
2015-08-13OE2805571.10 ppb
2016-08-09OE4132160.700 ppb
2016-08-09OE4132170.700 ppb
2017-08-03OE5465130.700 ppb
2017-08-03OE5465120.700 ppb
2018-07-23OE6874711.000 ppb
2018-07-23OE6874720.900 ppb
2018-08-28OE7058550.600 ppb
2018-08-28OE7058560.600 ppb
2019-08-07OE8466630.600 ppb
2019-08-07OE8466640.900 ppb