Those shells are cleaned up multiple times per year. We have to store the spent casings as no one including the landfill wants them for obvious concerns. We even sought out the company that makes ornamental lights out of them. We would have to pay the shipping to send them off site.
Any help is appreciated as the next step is a rule change that counts them as trash implying they have to be policed and leave when the shooter leaves.
Burn Pile. Give them back to mother earth.