If the filters are fiber, spun fiber, cotton, etc, they will only remove "chunks" like rust flakes from pipes, pieces of mud/dirt, and other things you can see in the water.
If the filters are carbon of some sort, then they will help remove organics. Chlorine would be the #1 thing you want out. If your municipality uses Chloramine, it's a different animal. You can call and ask, they will tell you.
Anything short of RO or DI will not remove sulfate, chloride, calcium, carbonate, etc. and will not affect the numbers you would get from a wards lab report.
The general rule of thumb is "If the water tastes and smells good, you can brew with it" once you get the chlorine out.
Tell me more about the filters and we can go in detail about what they can and can't do.