Rocky Mountain Power said Monday it will go to court to try to force the town of Willard to allow it to build a high-voltage transmission line through the city despite concerns that electric and magnetic fields from the project could harm the health of nearby residents and damage property values.

The utility plans to ask a 1st District Court judge to bar the town from interfering with its construction schedule after the Willard City Council late last week voted 3-2 to deny it final approval to build the line.

"It was an astounding vote," said Rocky Mountain Power spokesman Dave Eskelsen, who contended the city in early November already had approved the permit. "It certainly caught us by surprise."

Although Willard represents only a tiny segment of the 135-mile-long line that will run from southeastern Idaho to just west of Salt Lake City International Airport, the utility contends the city is now threatening its entire $600 million project. It says the line is needed to ensure the company has enough capacity to serve its Utah customers, whose demand for electricity continues to increase.

"The city's action must not be allowed to unnecessarily delay this project," Mark Moench, the power company's general counsel, said in a statement announcing the filing of a lawsuit against the city.

But Willard's city planner and spokesman, Jay Aguilar, said the council in November only gave the company preliminary approval for the construction permit. It specifically withheld final approval until everyone's concerns were addressed.

And last week a report and presentation by an independent consultant, Cindy Sage of Sage Consultants in Santa Barbara, Calif., raised new questions about the health impact of the electric and magnetic fields (EMF) that would be emitted by the high-voltage lines.

"It was new information that we didn't have," Aguilar said, indicating the report questioned and ran counter to Rocky Mountain Power's assertions that the safety of Willard's residents is not at risk.

In her presentation, Sage told the City Council that EMF is known to cause cancer and that children living in residences near high voltage power lines are reported to have increased risk of cancers, particularly of leukemia.

She said four different laboratories around the world have found that breast cancer cells grow faster under EMF exposures. There also is an increased risk of miscarriages among women with only intermittent exposure.

"EMF is a documented cancer-causing agent since 1998 in the U.S., and 2001 by the World Health Organization International Agency for Cancer Research," Sage reported.

She also raised the prospect that the transmission line would damage nearby property values. "Transmission lines affect future [land] use and development potential."

Rocky Mountain Power offers a different take.

It contends EMF risk to human health hasn't been established. "We're not health experts, so we're relying on the best scientific evidence available," Eskelsen said.

Willard isn't the only community to have concerns.

The segment of the transmission line that stretches from southern Box Elder County north to the Utah-Idaho border sparked more than one round of angry confrontations between the power, public officials and landowners, many of who were upset about the selected route.

"We told Rocky Mountain Power that there is a route through our city that would be acceptable, but they had already decided where they wanted to go and wouldn't consider any alternative," Aguilar said.