EWG's Tap Water Database — 2021 UPDATE



North Shore Water Commission

Antimony is a naturally occurring metal that enters tap water from plumbing fittings and also from industrial uses, such as production of metal alloys, batteries and plastics. Antimony causes organ damage and shortens lifespans in studies of laboratory animals.





Samples exceeding legal limit (MCL)


Samples exceeding
health guidelines

Testing results - average by year

YearAverage resultSamples takenDetectionsRange of results
20140.190 ppb110.190 ppb
20150.180 ppb110.180 ppb
20160.180 ppb110.180 ppb
20170.180 ppb110.180 ppb
20180.140 ppb110.140 ppb
20190.190 ppb110.190 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 1 ppb

The EWG Health Guideline of 1 ppb for antimony was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against change to the stomach and intestines.

EPA Maximum Contaminant
Level (MCL) 6 ppb

The legal limit for antimony, established in 1992, was based on a toxicity study in laboratory animals published in 1970. This limit does not include any additional consideration of children’s health.

ppb = parts per billion

All test results

Date Lab ID Result
2014-04-157805250.190 ppb
2015-03-038459960.180 ppb
2016-03-149098750.180 ppb
2017-04-189838350.180 ppb
2018-03-2010461010.140 ppb
2019-02-1911058890.190 ppb