By LISA CORNWELLCINCINNATI (AP) â¿¿ Ohio is seeking federal guidance on regulating underground caverns storing liquid propane and other liquid hydrocarbons after propane vapors were detected near a storage facility in southwest Ohio, saying if the response is inadequate, the state will seek authority to regulate them itself. State and local officials say no problems have developed from vapors detected last year in a monitoring well at an industrial landfill near the storage terminal in Monroe in Butler County, but the director of the Ohio Department of Natural Resources says such caverns need to be regulated to ensure public safety. ODNR Director James Zehringer sent a letter last week to the U.S. Department of Transportation asking whether federal regulatory authority over hazardous liquids pipelines extends to liquid propane stored in underground caverns. Ohio has five facilities with non-natural gas storage caverns around the state that appear to be unregulated, according to Zehringer. "This apparent lack of authority to regulate these storage caverns is a concern for us, given our mission to protect the people of Ohio," he wrote. Zehringer said such caverns should be regulated on some level, but Ohio needs clarification from the Transportation Department before developing any state regulations. He also wants to know whether federal officials are opposed to states developing their own authority to regulate the caverns and whether other states do that. ODNR spokeswoman Bethany McCorkle told The Associated Press that the state agency will "aggressively" pursue legislation to provide Ohio with the regulatory authority, if the federal government doesn't regulate the caverns. The Transportation Department's Pipeline Hazardous Materials Safety Administration did not immediately return calls for comment. The vapors in Butler County were detected near the storage terminal of Enterprise Products Partners, a Houston-based energy company that delivers products including propane used for fuel for home heating and industrial purposes. Enterprise spokesman Rick Rainey says propane is the primary product in the caverns mined out of shale. It is withdrawn or injected, according to customers' needs, and can be delivered through a pipeline or loaded onto trucks from the caverns.