Have you figured out a disposal solution? My local landfill won't accept them so I am getting ready to start looking at any waste to energy facilities in the region that will take them and hoping I might find one that accepts ties without a permit.
Fortunately I live far enough out that I can just burn them. They are all so old that most of the tar is out of them, so no one really catches on what I'm burning.
Maybe if you chainsaw them into chunks they wouldn't realize what you are dumping.