Environmentalists are divided over the merits of a Pepco Holdings plan to string a 500-kilovolt power line through the heart of Delaware to better connect southern power plants with growing demand in the mid-Atlantic region.

Pepco's proposed Mid-Atlantic Power Pathway would be like an interstate highway of electricity, designed to make more space on the often-choked power grid for electricity to flow to growing population centers on the East Coast.

Clean-air advocates say it could help carry clean wind power to the homes and businesses that need it, even as they worry it will also import dirty coal-fired power from the South and Midwest.

Wildlife and property-rights advocates are afraid the line will be a blight on the landscape, running through fragile areas along the Delaware River and Bay.

The most controversy in Delaware about the power line, which is now being examined by the public in a series of public hearings, is likely to focus on an eight-mile stretch of land in southern New Castle County.

The utility would need to acquire an easement through an area near the Delaware River that includes many wetlands and state-designated critical natural areas.

Officials at Pepco Holdings, the parent company of Delmarva Power, said the specific path there has not yet been chosen.

The planned power line would start in Dumfries, Va., cut through Maryland and across the Chesapeake Bay, then run through southern Delaware to the Indian River Power Plant. The line then would continue up the length of the state and across the Delaware River, ending in Salem, N.J.

It's one of several large lines planned in this region to shore up electrical reliability. Utility officials say it's especially needed on the Delmarva Peninsula, where power lines currently run only from the north. This would add a second path from the west.

Although power demand is down because of the recession, utility representatives say that won't last, and demand will one day overtax the existing grid.

By connecting three regional nuclear power plants, the new high-capacity line will spread power along the coast as well as bring in power from the coal-rich Midwest.

The $1.425 billion line is expected to add 40 cents to the average residential monthly electric bill. The costs would be borne by all electric users in the 13-state PJM Interconnection regional power grid.

The immediate need for the line is to move current through Delaware, but it also could be a useful outlet for the thousands of megawatts of renewable electricity that could one day be generated by wind turbines off the state's coast, said Joseph Minott, executive director of the Clean Air Council, an area environmental group.

Bluewater Wind plans to build a small wind farm off Rehoboth Beach and sell the electricity to Delmarva Power, but the firm also hopes to expand that farm in the future to feed more power to the grid.

If the transmission grid is strong enough, Delaware could export power throughout the region, Minott said, explaining why he favors the project.

"If you're going to create a vibrant market for wind energy, you need to be able to transmit it further than the town at the end of the beach," said Minott, who added that he had "trepidation and concerns" about the lines being used also to expand the reach for coal-generated power.

Rob Gramlich, policy director for the American Wind Energy Association, said a better transmission system is needed for onshore wind farms to carry their output to the wider populace.

Offshore wind is different, he said. Although it's more expensive than onshore wind, its appeal is in its proximity to population centers, he said. It doesn't take very many miles of transmission to get the power where it's needed, he said -- a problem for generators of wind power in the nation's more sparsely populated heartland.

Nick DiPasquale of Delaware Audubon said he would rather see small, localized, mainly renewable power sources instead of big lines that carry power from big coal-burning power plants. He's concerned about where the Power Pathway would go.

"If it means converting protected land to developed land -- even if the profile is relatively small -- I would find that a very troubling precedent," he said.

Utilities lose power when current is transmitted over long distances, said Carol Overland, a Minnesota attorney and electrical consultant who has been active on Delaware environmental issues. She said conservation and renewable-energy projects, using the existing power grid, should be sufficient.

State Sen. George Bunting, D-Bethany Beach, expressed concern that electromagnetic force, or EMF, from power lines has been investigated as a cause of childhood leukemia.

In a letter to Sen. Tom Carper, D-Del., he wrote, "There is a grave concern amongst many Delawareans" about the line.

The Centers for Disease Control and Prevention says there is no scientific consensus on the health effects of EMF.

Pepco Holdings owns the rights to much of the land it needs. It's planning to build the larger line along a right of way that already features smaller power lines.

But within the section of the line that runs from Indian River north to Salem, there will be areas where the right of way needs to be widened, the utility has said.

And there's a yet-to-be-specified section in southeast New Castle County where the Pathway would break from the existing power line along Del. 9 and head toward the Delaware Bay, where it would cross and connect with the Salem/Hope Creek nuclear plant.

That will require Pepco Holdings to acquire eight miles of new right of way, company officials said last week.

"Whether it's dry land, wet land, high land, I wouldn't want to answer that question right now," said Vince Maione, pathway project manager for Pepco. He added that the company wants to minimize impacts on the environment and the population.

PJM is still reviewing Pepco Holdings' application for the portion of the line running north from Indian River. Once that confirmation comes, Pepco Holdings will develop the path in greater detail, Maione said.

To cross the Delaware River, the utility wants to build a second overhead crossing, about six to eight miles south of its current line.

The company has not been in touch with Delaware landowners regarding easements, said Matt Likovich, a Delmarva spokesman.

Delaware state government has little control over the portions of the line for which Delmarva already has rights of way. Unlike in Maryland, this state's Public Service Commission does not have the authority to approve the location of a transmission line.

One of the few categories where state government has oversight is where a planned power line would cross natural areas like bodies of water and wetlands. Pepco Holdings has not been in touch to request a permit, said Philip Cherry, a state Department of Natural Resources and Environmental Control policy manager.

But Delmarva lacks leverage, at least on the state level, when it comes to expanding beyond its rights of way.

The state eminent-domain law doesn't give the utility the right to seize land for a power project. Likovich said if the company can't reach an agreement with a landowner, "we will have to construct the line by going around the property in question."

But the utility may hold a trump card: the U.S. Energy Department last year designated Delaware part of a region where the federal government can order an electricity project finished if states fail to do so.

Delmarva officials say they'll work hard to negotiate with landowners to avoid the issue of eminent domain.

"It doesn't benefit anyone to take anyone's land," Maione said. Pressed about whether the utility would be OK with the government seizing land for the project, he said, "We'll have to cross that bridge when we come to it."

Meanwhile, in Sussex County, Pepco Holdings held a community meeting in Gumboro on Thursday night, attracting 50 members of the public. The next meeting is Wednesday night in Millsboro.

Carper said the question of the power line needs to be considered in a larger context. He harkened back to the construction of Del. 1 to handle an increase in north-south travel, noting that along with the new road came a look at expanding public transit, car-pooling, and other alternatives to driving.

"Upgrading power lines on the Delmarva Peninsula may be necessary, but I hope Delawareans will take this opportunity to look not only at where a power line might go, but also at how they could help reduce the need for a new line in the first place," Carper said.

He said that could come by saving electricity, installing solar panels on their homes, adding insulation, purchasing Energy Star appliances, or taking other steps to save electricity.