(Updated Below) Earlier this week, we learned that the city learned a year ago that its covered reservoirs–i.e. the ones that hold our drinking water–are leaking. Or rather, the membranes atop them are. (Insane in the Membrane, joked the Beacon Hill Blog.) Thus, the company that installed the leaky material is power-washing it off, and the city plans to replace it with a more reliable rubberized asphalt. The thing is, there appears to be some confusion as to who will pay to get this done. In this morning’s Times story, utility spokesperson Andy Ryan says of the cost of replacing the membrane, “At the end of the day, someone is going to pay for it, and it’s not going to be us,” while utility spokesperson Cornell Amaya says that the utility expects to pay the “extra cost” to replace the old membrane with the new rubberized asphalt. Is Ryan referring to the removal and Amaya to the addition? We’ve got a call in to the utility to clarify. (For what it’s worth, Amaya’s voicemail message sounds like the Moviefone guy.)Update: Amaya says that the utility is certain that the leak wasn’t their fault–he likens the utility to a customer who hires architects and contractors to build a house, then finds that they didn’t meet the agreed-upon specifications–but that it will pay for all the repairs for now, as it doesn’t want the project to sit. After that, it will seek reimbursement for whoever is determined to be at fault. The matter “will likely be litigated,” he says. “Nobody wants to claim responsibility for it.”One potential political fallout: the covered-reservoir parks were touted by Greg Nickels in his agenda announcement on Wednesday–so while the leaks may be the fault of the membrane manufacturer, they seem likely to invite more criticism of the mayor’s managerial prowess, a popular target among his challengers.