We recently installed a pump (made by flo-jet if I remember correctly) under the sink and it has a dispenser on the sink that uses a five gallon plastic jug. We keep a crate with four one gallons in the bay for back up and just refill the bottle as necessary.
It is a 110 electric pump so it runs off the same circuit as the refrigerator. You can get the five gallon jugs filled for about a buck or so a lots of gas stations or convenience stores.
We went to this system because we ended up with some "funky" water that we drained and replaced and then added bleach to be sure it was going to clean the system up. So as previously mentioned by others we have separate drinking and washing water. Hard to tell what you are getting when you fill and if you let it stay and it is bad the bad seems to grow.