Water filters used to keep particulates, lead and other chemicals out of your tap water can help maintain a steady flow of clean drinking water at home. Many filters today even keep out traces of pharmaceuticals and over-the-counter drugs. As filters become more powerful and effective, that means they also become household hazardous waste at the end of their lifespan. The good news: Almost every water filter manufacturer has a filter recycling program. Be sure to visit the filter's website and download the mailing labels. Since filters need to be replaced every six months, this is an easy eco act to do just twice a year.