As Northeast Utilities and Hydro-Quebec begin seeking state and federal approval for the construction of Northern Pass, a $1.1 billion dollar project that would bring 1,200 megawatts of energy from a dam in Canada to southern New Hampshire, environmental groups say that it's too early to tell if the project will end up being truly "green."
The project will transfer electricity 180 miles through power lines running from the Canadian border to a converter terminal in Franklin and finally to a plant in Deerfield, where the electricity will then be moved onto the grid. Northeast Utilities and Hydro-Quebec said Northern Pass will provide clean, renewable energy to New England in addition to bringing jobs and tax revenue to New Hampshire.
Conservation groups are asking if the path of the power lines and the location of substations and converter terminals will destroy or alter valuable wildlife habitat. Some environmental advocates question whether large-scale dams produce greenhouse gases like their fossil-fuel counterparts.
The answers, environmentalists believe, will be revealed only as the project progresses.
Will construction hurt habitat?
"On a project like this, the important questions to ask are where are the power lines going to run, will they go through existing conservation land and what is being impacted," said Jack Savage, spokesman for the Concord-based Society for the Protection of New Hampshire Forests.
Northern Pass filed its first permit application with the U.S. Department of Energy on Thursday, making public for the first time the preferred and alternative routes for the 180 miles of power lines required to complete the project.
According to maps filed with the permit application, power lines would go through land in New Hampshire's northern counties that have none now. In those places, trees would be logged to clear a path for the lines and associated substations, said Anne Bartosewicz, project director for Northern Pass.
"For us, the environmental challenges have been in trying to choose a route that was least impactful," Bartosewicz said. "We've got mapping for protected and conservation areas, and we've done a really good job to try to weave around them in places that don't have a right of way right now."
About 50 miles of the power lines will be in new territory, and 130 miles will use existing paths, Bartosewicz said. In the new territory, a path of about 150 feet - an industry safety standard - would be cleared to accommodate the power lines.
In the middle and southern part of the state, the route is along existing power lines or other rights of way. For the most part, the route seems to skirt conservation lands, slicing through the White Mountain National Forest in a place where existing lines have already done the same.
Environmental advocates said that in places where wooded area is cut, it's important to minimize the environmental impact that can come with fragmentation.
"It's all the route plan," said Carol Foss, director of conservation for the Audubon Society in New Hampshire. For example, sectioning only a small piece of it off is healthier than cutting it right down the middle, Foss said.
Fragmentation can disrupt the breeding and hunting habits of species that need large territories and can promote the spread of invasive species, said Joel Harrington, spokesman for the Nature Conservancy in New Hampshire.
"The big issue with transmission corridors is that they can increase invasive species and invasive pests," Harrington said. "These are areas that have never been exposed to that much sunlight or heat, and invasive pests can grow and spread in those conditions."
Bartosewicz said concerns about wildlife are important to developing an ecologically sound plan and pointed out that the project is in the earliest stages of development.
Before all the needed permits have been granted, the construction route will be reviewed by the Department of Energy, the Environmental Protection Agency, the Department of Agriculture, the U.S. Corps of Army Engineers, the Forest Service, and the Fish and Wildlife Departments, she said. These agencies will be evaluating the environmental impact of the project and may require changes if they take issue with any of the plans.
Do dams produce greenhouse gas?
Carbon gets the bulk of publicity in the battle against global warming, but methane can trap up to 20 times more heat, according to some climate scientists' calculations. Methane is released by decaying plant matter left as wooded land behind a dam is flooded to create a reservoir.
While some experts agree that methane is a potent greenhouse gas emitted by dams, there is little research on how much and for how long it is produced after the initial flooding.
"Greenhouse gas emissions of large-scale dams are still an open question," said Jonathan Peress, an attorney for the New Hampshire chapter of the Boston-based Conservation Law Foundation, and director of its Clean Energy and Climate Change program.
To answer that question, the foundation has teamed up with three other nonprofit groups in the United States and Canada to research how much methane is produced by Hydro-Quebec's dams - which are some of the largest-scale dams in the world.
The organizations - including the Pew Environmental Group in the U.S. and Equiterre and the Canadian Boreal Initiative north of the border - have hired scientists at Global Forest Watch to analyze how much methane is produce at Hydro-Quebec's dams. With that information, said Peress, environmental groups can determine how Hydro-Quebec's greenhouse gas emissions measure up to carbon-producing power plants that burn fossil fuels.
Other research about dams' emissions have reported drastic results disputed by scientists, environmentalists and policy makers.
A 2007 study by scientists at Brazil's National Institute for Space Research found that combined, the world's largest dams produce 115 million tons of methane each year, making them one of the biggest sources of greenhouse gases created by humans.
But there's little research that examines dams on an individual basis, and they may vary greatly in their output of methane.
"Methane emissions are not an issue in Quebec because conditions are not conducive to methane production," said Ariane Connor, spokeswoman for Hydro-Quebec.
"Northern reservoirs, such as those in Quebec, emit insignificant levels of methane given that the water in our lakes and rivers is cold and well oxygenated, and that little organic matter is impounded," she said.
Peress said that the first round of research examining Hydro-Quebec's emissions should be available in the coming months and will shed light on how "green" this particular dam is when it comes to greenhouse gas production.
While no environmental group said they have a stance on the construction one way or another, all said that they will keep a close eye on the project as it unfolds.
"We're not going to prejudge this project until that analysis is completed," Peress said, "but based on the results, we will be intervening and advocating on this project."