The White River flows through Hartford as do Interstates 91 and 89. You can find these dump stations in Vermont primarily in campgrounds.
Brattleboro is also located right on the border with New Hampshire and borders the Connecticut River. Vermont RV dump stations in the area are all located in campgrounds or RV parks.
There's a good selection of Vermont RV dump stations in and around the Newport Area, most of which are located within state parks and charge a fee if you don't register as a camper. While in the area, you can visit Canada, Lake Salem, and Lindsay Beach.
There's plenty of city life in Burlington, and in the area surrounding, you'll find lots of outdoor destinations, such as the Milton Town Forest and Lake Champlain beaches. Vermont RV dumps in the area are primarily found in private and public campgrounds.
If you're looking for free RV dump stations in Vermont, then you will have to head to the city waste treatment facilities. The exception is if you are a registered guest at a campground or RV park that has a dump station onsite. The benefit of utilizing a campground or RV Park dump station are the presence of amenities and services and a place to spend a night or more.