I thought a lot of pharmaceuticals wind up in water supplies because when we take pills only part of the mass is used in the body, the rest stays in the blood s

I thought a lot of pharmaceuticals wind up in water supplies because when we take pills only part of the mass is used in the body, the rest stays in the blood stream, passes the kidneys, and is removed fairly intact into the urine thereby entering our water supply at the next voiding of the bladder.