EWG's Tap Water Database — 2019 UPDATE



Oak Park Water Service

Strontium is a metal that accumulates in the bones. Radioactive strontium-90 can cause bone cancer and leukemia, and any form of strontium at high doses can harm bone health. Read More.

Strontium-90 has been emitted widely by nuclear power plants, weapons facilities, waste sites and nuclear research facilities. Strontium-90 is structurally similar to calcium and is thus taken up into bones. The chief health concerns from strontium-90 exposure are bone cancer and leukemia.

No federal drinking water standards for strontium-90 exist. California set a legal maximum of 8 picocuries of strontium-90 radioactivity per liter of water. California also has a public health goal of no more than 0.35 picocuries of strontium-90 per liter of drinking water. According to studies by the U.S. Geological Survey, strontium-90 also is a concern for water quality in private wells.

Click here to read more on radiological contaminants.





Samples exceeding legal limit (MCL)


Samples exceeding
health guidelines

Testing results - average by year

YearAverage resultSamples takenDetectionsRange of results
20120.16 pCi/L114ND - 0.88 pCi/L
20130.15 pCi/L1911ND - 0.66 pCi/L
20140.14 pCi/L1912ND - 0.46 pCi/L
20150.29 pCi/L1910ND - 1.25 pCi/L
20160.16 pCi/L2012ND - 0.68 pCi/L
20170.80 pCi/L208ND - 2.00 pCi/L

pCi/L = picocuries per liter

State and national drinking water standards and health guidelines

EWG Health Guideline 0.35 pCi/L

The EWG Health Guideline of 0.35 pCi/L for strontium-90 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 cancer.

pCi/L = picocuries per liter

All test results

Date Lab ID Result