Drugs found in watersheds of 28 areas (AP)

At least one pharmaceutical or byproduct was detected in testing within the watersheds of 28 major metropolitan areas, according to an Associated Press survey of 62 major water providers and data obtained from independent researchers.

Test protocols varied widely. Some researchers tested for more drugs than others. Thirty-five areas said they tested. Four said tests were negative and three said they were awaiting results. Twenty-seven locations said they had not tested watershed supplies.

Here's the list of the 28 areas with pharmaceuticals detected, with the number found and some examples.