In Meredith, directly across from the town docks at the Mobil Gas-convenience store, they have a large sink with Meredith town water, and they will usually let you fill up your six gallon jug for free which is pretty danged nice of them considering how expensive the Meredith town water & sewer bills have become in the last year.
Plus, it's an easy carry back to the boat dock for both a blue, six-gal water container, or a red, six-gal gasoline porta-tank or both at the same time which would weigh about 90-lbs.......
......but as already mentioned the town treated water is usually a freebie there depending on who is working the cash register.