A sewage treatment plant in Canada has figured out a way to reduce the levels of chemicals that stick around in the treated wastewater, according to a new study. Eliminating them from our water system is important because they are devastating fish populations, and they can end up back in our bodies, too. Hormones from drugs like birth control, as well chemicals that mimic hormones, get into the water through normal human usage, because most drugs aren’t completely broken down and used up by the body.