The city of Dover's utility department may be required to bury power lines that run past a local airport.

A project already underway to replace city of Dover power transmission lines along U.S. Route 9 could end up costing more than projected after it was revealed an office within the state Department of Transportation had inadvertently been omitted from a mandatory review process.

The project involves installing new wooden utility poles along the roadway to replace ones that have reached the end of their service life. Dover's electric utility serves approximately 67 square miles of Kent County, including the 22 square miles within the Dover city limits.

However, because the new poles would violate regulations requiring certain areas of clearance around airports, the city may be forced − at extra expense − to bury the new lines, along with any cable television and Internet utility lines that also use the poles.

The problem lies along a stretch of Route 9 immediately adjacent to the Chandelle Estates Airport, a small privately-owned, public use airstrip north of the intersection with White Oak Road. The end of the airport's 2,533-foot runway sits approximately 50 feet from Route 9 and is immediately adjacent to the utility poles.

Replacing old utility poles is a more complicated process now than when the airport was built in 1962. Although regulations 50 years ago did not consider the 35-foot-tall poles dangerous, safety regulations enacted since then forbid any obstructions within certain distances of a runway. Those clearance areas are based on a complicated series of calculations that must be employed when planning utility work near airfields.

The work began three months ago after DelDOT reviewed and approved the project; the department was required to sign off on the plan because it would take place within its right-of-way, an area on either side of the roadway where DelDOT retains legal jurisdiction.

That's when airport manager Justin Hoffman began raising red flags.

"I saw the pole construction coming this way along Route 9, and I know there are regulations that prohibit this kind of construction without a permit," Hoffman said. He also knew DelDOT's Office of Aeronautics had to review and sign off on the construction plans.

City engineers working on the project insisted they had obtained the proper permits from DelDOT, he said.

Hoffman contacted the aeronautics division, and discovered their representatives knew nothing about the project.

"They were very upset that the city did not contact them because they felt the city had bypassed their department," Hoffman said.

However, it wasn't the city that was at fault, it was the transportation agency itself, said DelDOT spokesman Sandy Roumillat.

"There was one level of review and that was in our utility section," Roumillat said. "They approved the city of Dover electrical department to come in and work the right of way.

"Where the oversight occurred was because [the city] was simply replacing the power lines, the utility section did not make the aeronautics section aware of the situation."

Bobbie Geier, DelDOT's assistant director of statewide and regional planning, confirmed the agency has the authority to clear obstructions around runways like those at Chandelle Estates.

She also confirmed DelDOT is working with the city of Dover to develop a plan for putting the utility lines underground, although she could not address how that operation would be paid for.

Currently, DelDOT has agreed to the city lowering the new utility lines to the old height of 35 feet and has issued hazard notices to flyers using the Chandelle Estates airport.

"They're replacing the lines at exactly the same height as they were before," Geier said. "They did that right away as soon as they knew it was an issue.

"We're working with them and we hope to have a plan in a couple of weeks."

Dover City Manager Scott Koenig said the first thing that needs to be done is to make Hoffman and airport owner Roger Kruser comfortable about what's been done to stabilize the situation. The second is to come up with a plan to address the problem and figure out how much utility line must be put underground, if that is the ultimate decision from DelDOT.

From information he has so far, that distance could reach at least 1,000 feet, Koenig said, adding he could not speculate on the cost.

Any extra funding for the project would have to be figured into the city's budget, he said.