The environmental problems plauging a long awaited interstate highway project continue. While Penndot develops a response plan, there are questions about whether similar problems will be found elsewhere in the construction area. The project we are talking about is Interstate 99 in Centre County. PennDot has excavated thousand of tons of rock that has filled with acidic materials. There's concerns about those materials draining into nearby waterways. Penndot says the rock problem stems from the Skytop area of the road work, but there's another long stretch along the Bald Eagle mountain ridge where I-99 work is underway. Project managers for the I-99 construction Centre County say that acidic laden rock has not been discovered outside the Skytop area. But the ridge construction outside of Port Matilda isn't as far along as the Skytop work, so more future problems could lie ahead. For now PennDot is concentrating on what to do to remedy the possible problems from the acid rock runoff.