EWG's Tap Water Database — 2021 UPDATE


Chromium (total)

Dublin San Ramon Services District

Chromium is a naturally occurring metal, but industrial uses can elevate its levels in water. One form, hexavalent chromium, causes cancer. Total chromium is not a good indicator of the amount of hexavalent chromium in drinking water.





Samples exceeding legal limit (MCL)


Samples exceeding
health guidelines

Testing results - average by year

YearAverage resultSamples takenDetectionsRange of results
20132.10 ppb660.500 ppb - 5.80 ppb
20142.22 ppb220.330 ppb - 4.10 ppb
20151.14 ppb293ND - 12.0 ppb
20160.355 ppb311ND - 11.0 ppb
20170.452 ppb311ND - 14.0 ppb
20180.667 ppb513ND - 12.0 ppb
20191.05 ppb564ND - 16.0 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EPA Maximum Contaminant
Level (MCL) 100 ppb

The legal limit for total chromium, established in 1991, was based on a 1958 toxicity study in laboratory animals, and applies to both the less-toxic trivalent chromium and the more-toxic hexavalent chromium forms of this compound. This limit does not protect against the risk of cancer from ingestion of hexavalent chromium.

ppb = parts per billion

All test results

Date Lab ID Result
2013-05-07A3D2019-03A1.60 ppb
2013-05-07A3D2019-01A0.500 ppb
2013-08-05A3G2331-04A1.80 ppb
2013-08-05A3G2331-01A1.40 ppb
2013-11-06A3J2401-01A5.80 ppb
2013-11-06A3J2401-04A1.50 ppb
2014-02-04A4A1601-04A4.10 ppb
2014-02-04A4A1601-01A0.330 ppb