I'm not one to worry about the quality of campground water. I do spend my winters in the Rio Grande Valley and the water here is potable and safe to drink. It is also very "Rank". I use a sediment and a charcoal filter for the whole trailer. I also have a Reverse Osmosis System mounted under sink for drinking water.
Before you think this is a great idea, you need to understand this doesn't get rid of bad bugs. It also dumps about 10 gallons of water for every gallon it makes. It will fill your gray tanks in less than 24 hours if they are not open. You do not want to be paying for the water either.
Having said that, my water tastes good and makes great coffee.