The Black Berkey filters have been tested through the years by various independent EPA approved laboratories. NMCL, the manufacturer, publishes the results of these drinking water tests on the Black Berkey filters to provide people with the information they need to make an informed decision when purchasing a water filter. Below you will find links to testing done upon the Black Berkey filters for the elimination of among other things: heavy metals, bacteriological pathogens, radioactive isotypes, pharmaceuticals, perfluorinated chemicals etc. If you have any questions or concerns related to the results of these drinking water tests please don't hesitate to contact us at info@berkeywaterfilterseurope.com..