EWG's Tap Water Database — 2021 UPDATE



Harrison County Public Water Supply District 1

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
20140.725 ppb220.710 ppb - 0.740 ppb
20150.600 ppb440.560 ppb - 0.660 ppb
20160.609 ppb87ND - 0.850 ppb
20170.734 ppb880.580 ppb - 0.900 ppb
20180.265 ppb42ND - 0.550 ppb
20190.780 ppb220.700 ppb - 0.860 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
2014-07-29AC307000.740 ppb
2014-07-29AC306990.710 ppb
2015-07-22AC543140.620 ppb
2015-07-22AC543150.660 ppb
2015-10-20AC612300.560 ppb
2015-10-20AC612290.560 ppb
2016-01-26AC650370.520 ppb
2016-05-16AC693950.610 ppb
2016-05-16AC693960.660 ppb
2016-07-27AC797120.690 ppb
2016-07-27AC797130.720 ppb
2016-11-07AC863040.850 ppb
2016-11-07AC863030.820 ppb
2017-03-06AC919770.580 ppb
2017-03-06AC919760.580 ppb
2017-07-17AD014240.660 ppb
2017-07-17AD014250.640 ppb
2017-08-28AD058560.870 ppb
2017-08-28AD058550.900 ppb
2017-10-23AD079100.840 ppb
2017-10-23AD079090.800 ppb
2018-07-24AD292000.510 ppb
2018-07-24AD292010.550 ppb
2019-08-06AD518180.700 ppb
2019-08-06AD518190.860 ppb