Wearing the board out this a.m.

Any tips for processing beer kegs?
Got a buddy that was doing a micro brewery, didn't work out. Not 100% sure why he even had the kegs, but he is willing to give them to me.
There are 23 kegs, but my yard will not take them. They really won't tell me why or what I need to do to them so that they will take them.

Anybody know the deal on this?