Americans love their medications. Pharmacists fill more than 3 billion prescriptions a year in the United States, and consumers also buy huge quantities of over-the-counter drugs. Many of those pharmaceuticals enter wastewater when people urinate. Others end up there when unused medications are flushed into toilets to dispose of them - a practice that pharmacists recommended for years because it prevents drugs from falling into the wrong hands or confusing elderly patients. Even sending drugs to landfills tends to have much the same result, as buried substances leach into groundwater.

Now, as evidence of the persistence of endocrine-disrupting chemicals in the environment grows, a number of communities are establishing so-called "take-back programs" to keep unused pharmaceuticals from entering their wastewater systems. It's no easy task, since many prescription drugs are classified as controlled substances that can only be handled by licensed personnel, such as law enforcement officials.

"The regulations that we've put into place in this country, for good reasons, are now making it really difficult for people to do the right thing," says Brenda Bateman of the Tualatin Valley Water District in Oregon, who has been conducting a study of take-back programs. "We've really set up a barrier about who you can hand unneeded pharmaceuticals to."

Oregon officials are currently working on a program to collect surplus medications at nursing homes, and many communities around the country have set up periodic events at which members of the public can safely discard drugs they no longer need. But California's San Mateo County has pioneered a permanent drop-off program. Officials there have set up converted mailboxes or book-drop boxes inside about a dozen police stations. Only officers can remove medications dropped in them; then the drugs are transferred to a company that collects and incinerates medical wastes. In its first year of operation, the program has collected about a ton of pharmaceuticals at a disposal cost of about $1.60 a pound.

"A buck sixty to get rid of a pound of hazardous waste," says Bill Chiang, a legislative aide to County Supervisor Adrienne Tissier, who spearheaded the program. "That's pretty good."