If you are connected to a public water system you should receive an annual water quality report before July 1, it'll tell you where your water comes from and what's in it. You can also find much of this information by visiting the epa website and looking up your specific water supply. Here at River Soap offices, we use a solid carbon block filter system from multipure. We like it a lot and best we only need to replace the filter once a year. There's lots to choose from, check out EWG great water filter guide.