Bring us your tired, your old, your expired, unused prescription drugs, says the Drug Enforcement Agency.

This Saturday, the DEA wants people around the country to raid their medicine cabinets and bring their unwanted drugs to more than 3,400 collecting sites around the country. Bring us your unused prescription drugs, DEA says

Flushing drugs down the toilet could contaminate the water supply. And tossing them in the trash can make them easy to find for misuse.

The DEA answered CNN.com's questions about its drug collection day:

What is DEA going to do with all these drugs?

The drugs collected will be in the custody of a law enforcement officer until their incineration. The medications will be incinerated according to federal and state environmental guidelines.

If flushing or throwing the drugs away in the trash is not recommended, what is the public suppose to do with them when the DEA isn’t collecting them?

The White House Office of National Drug Control Policy’s strategy for combating prescription drug abuse includes increasing the number of take-back programs like this one in 2010, making this service available to more and more communities. DEA is committed to holding controlled substance take-back programs regularly and increasing the number of community partners who participate, thus increasing the number of collection sites throughout the nation.

Take-back programs are the best way to dispose of old drugs. But if a program is not available: Take the meds out of their bottles; Mix them with something unappealing like used kitty litter of coffee grounds; Seal them in a bag or disposable container, and throw that away.

The Take-Back Day event, which is free, takes place Saturday between 10 a.m. and 2 p.m. People who want to get rid of their prescription medicines can log onto the DEA website to find their local drop-off sites.