I understand that pills flushed down toilets have created some problems at sewage treatment plants. What is the recommended method for disposing of unwanted or outdated pills?

I understand that pills flushed down toilets have created some problems at sewage treatment plants. What is the recommended method for disposing of unwanted or outdated pills?

— Tom N., Ashland

Not just at sewage treatment plants, Tom. Pharmaceuticals are being found in groundwater all over the place these days, with unknown consequence to the environment.

The Environmental Protection Agency and the Oregon State Pharmacy Association recommend mixing your unwanted medications with an undesirable substance, such as coffee grounds or kitty litter, placing the mixture in a sealed container or bag and throwing it in the garbage. In addition to being, well, gross, kitty litter is also good for absorbing leftover liquid medications.

These steps should keep the drugs out of the hands of children, experimenting teens and drug users, while protecting the environment.

Jim Thompson, executive director of the Oregon State Pharmacy Association, notes there is still some concern about groundwater contamination from drugs buried in landfills, but this seems to be the best option for now.

In January, Thompson expects the Legislature to take up drug-disposal and clean-water proposals that could include disposal depots at pharmacies, police stations or other agencies.

The collected medications then could be incinerated to keep them out of our water, he said.

Thompson also has some advice that will keep people healthy and the environment clean — take your whole prescription until all the pills are gone, unless your doctor advises otherwise.

Then you'll get the desired benefits of the medication and won't have to worry about a safe way to toss the leftovers.