I seem to remember that the coal leaving the Powder River basin had to be sprayed with a dust control agent, and that was a process to get one working the meet the BNSF and STB approvals.

Also since when did local politicians get the authority to regulate interstate commerce. I understand they are trying to do a 'green' thing here, but they have no power over the RR, maybe they should go after the shipper, who is responsible for containing his product.