Chetopa, KS is near lots of great places to explore in an RV, and there are plenty of RV maintenance resources throughout Kansas. The dump station in Chetopa is open year-round, and you can find free non-potable water there as well.
There are a few storage businesses across Kansas that let you use their dump stations at no cost too. If you see an RV storage place, then you can probably dump your wastewater there as well.