EWG's Tap Water Database — 2021 UPDATE



Stockton Town 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
201430.0 ppb3328.0 ppb - 34.0 ppb
201529.0 ppb3324.0 ppb - 33.0 ppb
201622.0 ppb1122.0 ppb
201722.7 ppb1122.7 ppb
201823.7 ppb1123.7 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 Result
2014-06-0828.0 ppb
2014-11-0334.0 ppb
2014-12-0128.0 ppb
2015-01-0830.0 ppb
2015-02-0233.0 ppb
2015-04-2024.0 ppb
2016-08-0122.0 ppb
2017-10-0222.7 ppb
2018-09-1723.7 ppb