Pictures of said boat might help get you some better advice.

One of the problems - besides the solid waste component of old boats - are integral fuel tanks. Emptying old fuel and properly disposing of these tanks cost money. Some disposal facilities will require proof the boat doesn’t have fuel/wastewater tanks.

If you’re handy, you could rent a dumpster and cut the boat up with a sawzall. It might be a bit cheaper than having someone haul it whole.