EWG's Tap Water Database — 2021 UPDATE



Northwest Forest Municipal Utility District

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
201416.7 ppb1116.7 ppb
201588.6 ppb1188.6 ppb
201632.0 ppb2216.4 ppb - 47.5 ppb
20171,220.0 ppb22920.0 ppb - 1,520.0 ppb
201832.7 ppb545410.5 ppb - 67.8 ppb
201918.1 ppb666.60 ppb - 40.5 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