Treated human sewage mixed with organic debris creates more than compost. It’s also the recipe for a major fight by several Port St. Lucie neighborhoods against the developers of a proposed compost facility. Right now, it’s just 189-acres of empty citrus grove on Shinn Rd. in unincorporated St. Lucie County. But, it’s what might be going there that has folks so upset. Compost USA of the Treasure Coast is seeking permission from the county to develop a biosolids composting facility.