EWG's Tap Water Database — 2021 UPDATE



Foxcroft School

Barium is a mineral present in rocks, soil and water. High concentrations of barium in drinking water increase the risk of cardiovascular disease and hypertension.





Samples exceeding legal limit (MCL)


Samples exceeding
health guidelines

Testing results - average by year

YearAverage resultSamples takenDetectionsRange of results
201567.0 ppb1167.0 ppb
201684.3 ppb3352.0 ppb - 104.0 ppb
201889.4 ppb1189.4 ppb
201979.3 ppb3342.0 ppb - 108.0 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 700 ppb

The EWG Health Guideline of 700 ppb for barium was defined by EWG as benchmark that protects against harm to the kidneys and the cardiovascular system.

EPA Maximum Contaminant
Level (MCL) 2,000 ppb

The legal limit for barium, established in 1991, was based on a 10-week study of barium exposure in 11 adult male volunteers. This limit does not include any additional consideration of children’s health.

ppb = parts per billion

All test results

Date Lab ID Result
2015-11-03VA010-DCLS67.0 ppb
2016-07-27E160601591104.0 ppb
2016-07-27E16060158397.0 ppb
2016-10-25E16090397252.0 ppb
2018-09-230116791-MET89.4 ppb
2019-07-22E190606979108.0 ppb
2019-07-22E19060698088.0 ppb
2019-07-22E19060698142.0 ppb