So how are all these drugs getting in the water in the first place? Some fraction of every dose a person takes passes through unmetabolized and is evacuated by the body and flushed into sewage systems. Sewage treatment plants are meant to remove the more familiar kinds of pollutants, and typically do not remove pharmaceuticals from waste water as it is cleaned up and released back into the environment, eventually to find its way into other water supply systems. In some places, treated sewage water is reused directly for drinking water after several filtration processes to make it safe, although none of the systems in wide use effectively remove pharmaceuticals.NYT.
That Brita filter in your kitchen is not likely to do the trick, either. As for bottled water, it, too, may come from a tap, rather than some remote mountain spring. And the trade group representing bottled-water sellers told The A.P. that they aren’t testing for the presence of trace drugs anyway.
Don't worry, though. The experts say everything is fine.