The Leesburg Town Council voted unanimously Tuesday night to urge Dominion Virginia Power to build its planned transmission lines in western Loudoun underground.

"I don't want to see these power lines in anybody's way," council member Melinda H. Kramer said of the vote and a decision not to discuss alternative aboveground routes.

Dominion says it needs to build a 10- to 12-mile power line with 110-foot towers and a substation to meet growing electricity demands in western Loudoun. The utility initially planned to build most of the transmission lines along the Washington & Old Dominion trail but backed down after widespread opposition from trail users and nearby residents.

The company has not chosen a new route in western Loudoun and is now facing community opposition over the two miles it plans to build in or near Leesburg. One route under consideration would take the lines along the W&OD and Route 7 corridor through Leesburg. Another would head just west of the town border and meet up with Dry Mill Road. Or it could follow the Sycolin Creek floodplain farther south and west of the town before crossing Harmony Church Road -- or some combination of the above.

The Dry Mill Road and Sycolin Creek routes would take the power lines near Leesburg Executive Airport.

"I can't support either of those two routes," council member Susan B. Horne said at Monday night's work session. "Anything that puts a 110-foot power line in the approach to the airport is not a safe situation."

Bruce G. Douglas, a senior planner in Leesburg, told the council that because the ground where the power line would go through was lower than the runway at Leesburg Executive Airport, the power line would not be in the path of landing airplanes.

The routes will be chosen by the State Corporation Commission, a regulatory agency, after Dominion submits its application, which is expected by March. The process typically takes about a year.

The Town Council has passed two resolutions opposed to building a power line along the W&OD trail, but this is the first calling for an underground alternative. The Loudoun County Board of Supervisors voted this month to urge Dominion Virginia Power to submit the Route 7 corridor to state regulators as the primary route and to put the line underground.

Dominion said it was not considering any underground proposals.

"Only when we cannot get an overhead route do we consider underground," said Mark Allen, the company's manager of transmission-line engineering.

Allen said underground lines cost $7.5 million to $10 million a mile, compared with $750,000 to $1 million a mile for aboveground power lines. He also said that repairing an underground line takes longer because it can be tricky finding where the problem is underground and then digging up the line. In addition, Allen said that having some underground lines in a system that is mostly aboveground can cause the lines below to become overloaded.

Also Monday, Kaj H. Dentler, the town's director of parks and recreation, said an environmental engineering firm has been hired to determine whether runoff from surrounding developments is causing excessive algae to grow in the pond at Olde Izaak Walton Park. The firm will also study the depth of the pond and its sediment level.

Dentler suggested that the council reevaluate its long-term plans for the 21-acre park, which is owned by the Failmezger family. Leesburg signed a 30-year lease in 2000 and has paid about $110,000 in rent each year since. The town has spent at least $100,000 more in maintaining the site -- money that improves the owner's property value but not the town. He said the town should consider either buying it outright or letting it go.

"I think that this is one of those jewels of Leesburg that we cannot allow to escape," council member Robert J. "Bob" Zoldos said.