I refill at a McDonald's on my routine ride. Cold water right from the soda machine. Feel awkward walking in there covered in sweat and probably stink too but no one has said anything to me yet
On one of my trail rides I pass a little league field. One of the buildings has an outside sink that is on except for in the winter. My bottles do not fit very well but good boutfor about 1/2 full. The park service has pumps with iodine treated water along the C&O trail. I've only had to use them twice for drinking water, used them a lot to put over my head. It's "ground water cold" but it's tinted brown and has a metal taste. Better than nothing. Most larger grocery and retail stores have them but unconvieneantly located in the back. The W&OD trail in northern VA has a lot within site of the trail. I think I've seen some of those cool bike repair stands on that trail too, the ones with the tools on cables.