EWG's Tap Water Database



Clearwater Water System

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
201014.1 ppb338.40 ppb - 20.0 ppb
201116.3 ppb339.90 ppb - 20.0 ppb
201214.9 ppb337.70 ppb - 21.0 ppb
201362.8 ppb32ND - 180.0 ppb
201427.0 ppb1127.0 ppb
201510.3 ppb336.90 ppb - 15.0 ppb

ppb = parts per billion.

State and national drinking water standards and health guidelines

Health Guideline 700 ppb

The health guideline of 700 ppb for barium was defined by the Environmental Protection Agency as a children's health-based limit for 10-day exposure, a non-enforceable federal health advisory. This health guideline protects against harm to internal organs.

ppb = parts per billion.

EPA Maximum Contaminant
Level (MCL) 2,000 ppb

The enforceable federal standard that defines the highest level of a contaminant allowed in drinking water.

ppb = parts per billion.

EPA Maximum Contaminant
Level Goal (MCLG)2,000 ppb

A non-enforceable federal health guideline. For cancer-causing chemicals, these health goals are typically set to zero.

ppb = parts per billion.

All test results

Date Result
2010-02-108.40 ppb
2010-02-1014.0 ppb
2010-02-1120.0 ppb
2011-02-169.90 ppb
2011-02-1620.0 ppb
2011-02-1619.0 ppb
2012-02-107.70 ppb
2012-02-1016.0 ppb
2012-02-1021.0 ppb
2013-02-01180.0 ppb
2013-02-018.50 ppb
2014-02-1327.0 ppb
2015-01-1315.0 ppb
2015-01-139.00 ppb
2015-05-076.90 ppb