Believe it or not, this is actually a very well known fact by biologists and has been for many years. Just because you didn't know about it until today doesn't mean some big cover up, it means you didn't do any research.
For example, we've known for about a decade now that pharmaceuticals, particularly hormones derived from birth control pills, pass through sewage treatment facilities into drinking water. In fact, it's such a problem in some areas that fish are changing their genders. Here's an article that was published in 2007, just to give you an idea:
http://news.nationalgeographic.com/n...-sex-fish.html
Unfortunately, hormones and other pharmaceuticals are extremely difficult to filter using standard water treatment processes. These are tiny molecules. There has been some work to try to filter them out (see:
http://www.scientificamerican.com/ar...n-water-supply, published in 2009), but I'm not aware of the current state of these developments.