by Stephanie CrosbyThe use of coal to heat buildings will be phased out on the University of Louisville’s Belknap campus by 2015. It’s part of an agreement signed today between U-of-L and the Air Pollution Control District.U-of-L vice-president for business affairs Larry Owsley says that campus has three boilers. One operates on either coal or fuel oil – he says they’ll switch to fuel oil only on that one.Another is an aging natural gas boiler that he says will be replaced soon.“We’re working on it this fall, it would be in place for the winter season," says Owsley. "So we’ll be using a combination of fuel oil and natural gas this winter season, so that timeline is immediate.”The natural gas boiler replacement costs about two-million dollars and is already covered under an existing energy efficiency contract.The third boiler operates only on coal, and will cost three-million dollars to replace with a natural gas boiler. Owsley says they don’t know yet how the university will pay for the replacement, but has committed to do so by 2015.