It's pecan season right now, which means a couple of things:
Hulls are free or dirt cheap. Soaked pecan hulls make good smoke.
If the pecans are falling, that means the hickory nuts are falling in the woods. Those are free, of course.
It depends on what was asked for and what was in the statement of work. I rather doubt you could recover anything because I doubt stripping the bridge was part of the work.