An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Environmental Sampling and Analytical Methods (ESAM) Program

EPA Method 903.1: Radium-226 in Drinking Water Radon Emanation Technique


U.S. EPA, EMSL. 1980. “Method 903.1: Radium-226 in Drinking Water Radon Emanation Technique.” Prescribed Procedures for Measurement of Radioactivity in Drinking Water, EPA/600/4/80/032.


Analytical Method


EPA’s Selected Analytical Methods for Environmental Remediation and Recovery (SAM) lists this method for confirmatory analysis of radium-226 in drinking water samples.

You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.