Drugs in the water supply

Jokes about dosing the water supply have long been a staple of countercultural troublemakers, but as it turns out, we've all been doing it for a long time now:

Residues of birth control pills, antidepressants, painkillers, shampoos and a host of other compounds are finding their way into the nation’s waterways, and they have public health and environmental officials in a regulatory quandary.

On the one hand, there is no evidence the traces of the chemicals found so far are harmful to human beings. On the other hand, it would seem cavalier to ignore them.

The issue is most pressing in streams and rivers, where fish and other species are mutating; but it could be the case that they've been mutating all along and we just didn't know it. Meanwhile, municipal water supplies are filtered heavily enough that these contaminants - as best as we can tell so far - aren't the problem. Still, it's kind of creepy to think about:

In many cases, the compounds enter the water when people excrete them or wash them away in the shower. But some are flushed or washed down the drain when people discard outdated or unused drugs. So a number of states and localities around the country have started discouraging pharmacies, hospitals, nursing homes and residents from disposing of drugs this way. Some are setting up “pharmaceutical take-back locations” in drugstores or even police stations. Others are adding pharmaceuticals to the list of hazardous household waste, like leftover paint or insecticides, periodically collected for safe disposal, often by incineration.

People really flush their unused drugs down the toilet? Who told people that was a good idea - was there campaign back in the misguided '50s, alongside "cigarettes are healthy" and "let's all eat lard", to flush unused drugs instead of stockpiling them for the inevitable nuclear apocalypse?