Yep, the house has always had one. The only thing not filtered, are the outside spigots. Its spring water off the side of the hill that comes out of the ground thru a underground pipe into a 3 compartment concrete below ground holding tank. Water comes in, fills up that shallow compartment, then overflows thru a pipe to the main large compartment which has a hd submersible pump at the bottom, then when that is full, it goes thru another pipe that dumps it into the other compartment which has a floor drain in it and it gets discharged out down the hill. Pretty neat, it continuously flows in and back down the hill. Often, salamanders and crawfish are swimming around in there year round, but if its good for them its good for me. The water itself and the movement keep it from freezing.