A proposed coal ash landfill at Louisville Gas and Electric’s Trimble County plant has hit another roadblock. The state Division of Waste Management is still concerned that a cave on the property could be an issue.LG&E is seeking a permit to build a coal ash landfill near its Trimble County Power Station. But the discovery of a cave on the propertyhas thrown a logistical wrench in the permitting process.Last month, LG&E responded to the state’s concerns, saying that the cave isn’t actually a cave, but rather a “cave-like structure.” In a letter sent last week, the state Division of Waste Management told LG&E it wasn’t sure about that classification, and wants the company to hire a cave expert to survey, map, and classify the cave.Ron Gruzesky is the director of the state’s solid waste branch.“This is a very unique red flag. We don’t face this very often,” he said. “Generally the kind of things that we find, they truly are deficiencies in the application and generally what we find is that an applicant can correct deficiencies that we find in the application. This is a little unique. There’s actually a possibility that they wouldn’t be able to correct this one.”Gruzesky says besides complying with the law, the state is worried about flowing water in the cave, and what that could mean for a landfill.“We’re very concerned about the transport of contaminants through the groundwater. So we would need to know how water flows under this feature and if that can be addressed,” he said. “For example, if they really can eliminate it, then that’s a problem that can be overcome. To make that determination, they really have to find the water, where it’s coming from and where it’s going.”A spokesman for LG&E says the company still doesn’t believe the cave falls within the state law. LG&E has until November 15 to have the cave surveyed and respond to the state’s concerns.