Some researchers, like Buckley, say it's necessary to investigate the water supply; if prescription drugs take action on the body in pill form, they're likely to have some effect when absorbed through another medium like water.
There are ways to protect oneself. ABC News asked researchers to test a widely available water filter for the home. They found it greatly reduced the traces of drugs in the water.
And communities across the country are creating drop-off locations where people can bring expired drugs to be incinerated, preventing them from ending up in rivers and streams and contaminating the water supply.
"I used to flush unused Ibuprofen down the toilet rather than have my small children consume them," said Kirsten Calia, a mother from Connecticut. "But now I know that there are great environmental ramifications to this."