OM- that article states that the EPA simply uses the tests that are done by the manufacturer of the treatment devise/method - they do not do independent testing.

What the article does imply is that there is no need to treat cook water if it is brought to a full boil.

And I do think that 99% of the "success" of treatment is due to no problems to begin with. At least, in the high mountain areas where I backpack. If you think about it, a tumbling mountain stream is aerated, somewhat filtered and subject to high intensity UV, all "treatment" methods.

Things may be different in lower altitude more agricultural settings or in campgrounds.