According to an Associated Press survey of 28 major metropolitan areas, prescription and non-prescription drugs were found in the watersheds of more than a few cities. Data was obtained from 62 major water providers and independent researchers.

Test procedures at each location varied wildly. Some researchers tested for more drugs than others. In all, 35 said that they tested, four said tests were negative, and three were awaiting results. 27 locations said that they did not test watershed supplies.

At least one pharmaceutical or byproduct was detected in the treated drinking water supplies. Coffee and tobacco are widely used, and researchers said that their byproducts are often a good indicator for the presence of pharmaceuticals. Researchers therefore routinely test for, and quite often find, caffeine and the metabolite in nicotine, cotinine, more often than any other drugs.

The following metro ares tested positive for the presence of drugs:

Arlington, Texas: 1 (unspecified pharmaceutical)

Atlanta: 3 (acetaminophen, caffeine and cotinine)

Cincinnati: 1 (caffeine)

Columbus, Ohio: 5 (azithromycin, roxithromycin, tylosin, virginiamycin and caffeine)

Concord, Calif.: 2 (meprobamate and sulfamethoxazole)

Denver: (unspecified antibiotics)

Detroit: (unspecified drugs)

Indianapolis: 1 (caffeine)

Las Vegas: 3 (carbamazepine, meprobamate and phenytoin)

Long Beach, Calif.: 2 (meprobamate and phenytoin)

Los Angeles: 2 (meprobamate and phenytoin)

Louisville, Ky.: 3 (caffeine, carbamazepine and phenytoin)

Milwaukee: 1 (cotinine)

Minneapolis: 1 (caffeine)

New Orleans: 3 (clofibric acid, estrone and naproxen)

Northern New Jersey: 7 (caffeine, carbamazepine, codeine, cotinine, dehydronifedipine, diphenhydramine and sulfathiazole)

Philadelphia: 56 (including amoxicillin, azithromycin, carbamazepine, diclofenac, prednisone and tetracycline)

Portland, Ore.: 4 (acetaminophen, caffeine, ibuprofen and sulfamethoxazole)

Riverside County, Calif.: 2 (meprobamate and phenytoin)

San Diego: 3 (ibuprofen, meprobamate and phenytoin)

San Francisco: 1 (estradiol)

Southern California: 2 (meprobamate and phenytoin)

Tucson, Ariz.: 3 (carbamazepine, dehydronifedipine and sulfamethoxazole)

Washington, D.C.: 6 (carbamazepine, caffeine, ibuprofen, monensin, naproxen and sulfamethoxazole)