EWG's Tap Water Database — 2019 UPDATE



North Texas Municipal Water District Tawakoni Water Treatment Plant

Manganese is a naturally occurring element that is common in food and drinking water. Excessive manganese exposures may impair children's attention, memory and intellectual capacity. Click here to read more about manganese.





Samples exceeding legal limit (MCL)


Samples exceeding
health guidelines

Testing results - average by year

YearAverage resultSamples takenDetectionsRange of results
201235.2 ppb1135.2 ppb
20133.59 ppb113.59 ppb
20144.30 ppb114.30 ppb
201515.0 ppb1115.0 ppb
201612.0 ppb1112.0 ppb
201793.0 ppb1193.0 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 100 ppb

The EWG Health Guideline of 100 ppb for manganese was defined by the state of Minnesota as a health risk limit, the concentration of a contaminant that can be consumed with little or no risk to health. This health guideline protects against harm to the brain and nervous system.

ppb = parts per billion

All test results

Date Lab ID Result
2012-12-12121255900235.2 ppb
2013-08-20Q13058070043.59 ppb
2014-11-10Q14552840014.30 ppb
2015-05-28Q151964800415.0 ppb
2016-05-25Q162079600112.0 ppb
2017-06-27Q172683100193.0 ppb