Presumably, if the county (or transit district, whoever holds title) were to abandon the railroad, and it were to actually happen (previous threads have described the convoluted and uncertain process involved), they would have to pay the state its money back. All of it, possibly with interest. That's the way it usually works when you accept funding for one purpose then change things later. I'm certain there would be some disagreements about details, and various lawyers would make some money in the process, but ultimately the only way out of paying it back would be some kind of special legislation repurposing it after the fact or allocating repayment out of another account that better fits the ultimate use - does SC have that kind of clout?