Citizens and conservation groups in Maryland are anxiously awaiting a series of decisions that could lead to a massive new power line that would impact cultural and natural resources on both sides of the Chesapeake Bay-or could undercut the project completely.

The Mid-Atlantic Power Pathway is a new, high-voltage transmission line proposed by Pepco Holdings Inc., MAPP would move energy along a 152-mile route from northern Virginia to the Delmarva Peninsula.

It would include the first power line to run under the Bay itself and much of the Choptank River. It would also have the largest permanent impact to nontidal wetlands ever permitted by the Maryland Department of the Environment.

"MAPP is about moving energy," said MAPP project manager Bob Jubic. "Without it, when demand reaches a high, we won't have the transmission system to move the energy."

Jubic said that MAPP will benefit the Middle Atlantic region by improving the reliability of the power grid and stabilizing energy prices. The use of a DC power line for part of the route would also increase flexibility in distributing energy from a range of sources, from Appalachian coal-fired plants to wind farms in the Atlantic or even in the Midwest.

But some citizens and conservation groups say the benefits are overstated and the proposed route is a bad choice. Some even question the need for the project.

PJM Interconnection, which manages the power grid for a 19-state region, has raised the same question and is studying the matter further.

PJM first identified the need in 2006 for MAPP to provide reliable energy to consumers. Their annual forecast of transmission needs showed that the region's aging infrastructure was not equipped to meet growing demands for energy. Congestion in the energy flow could increase the chance of brownouts or blackouts in the Middle Atlantic States by 2015.

Although PJM has reviewed and restated the need for MAPP annually since 2006, this year's analysis came with words of caution.

In an April letter to PHI, PJM emphasized the "uncertainty surrounding a number of the assumptions" driving the need for MAPP and said that different sources of data "produce widely different results."

Richard Klein of Community Defense and Environmental Defense Services has worked with dozens of groups concerned about MAPP. "MAPP is like having a second set of spare tires in your car," Klein said. "It helps, but other alternatives might cost less and do the same thing."

Changes in the economy, as well as the analysis process, recently led PJM to withdraw support for a different project known as the Potomac-Appalachian Transmission Highline (PATH). Economic downturns have slowed the demand for energy and pushed the need for PATH beyond the foreseeable future.

PATH was canceled, and worried citizens on both sides of the Bay hope MAPP will meet the same fate.

But PHI maintains that MAPP is "a very distinct project with a distinct need." They say PATH was canceled because other solutions were available for that particular set of problems.

PJM's findings are due in August.

"We're confident they will still move forward," Jubic said.

In the meantime, permitting and funding processes continue at both state and federal levels.

The 500-kilovolt line would begin at an existing substation along the Potomac River, travel through southern Maryland, and enter the Bay just north of the Calvert Cliffs Nuclear Power Plant.

The underwater cable would continue up the floor of the Choptank River to resurface in Dorchester County, MD, cross the Nanticoke River on transmission towers, and end at Indian River, DE.

The Maryland Department of the Environment is evaluating a wetlands permit for a portion of MAPP on the Western Shore. This 52-mile section will add three cables to transmission towers that have been in place for decades.

If approved, this part of the route would impact some of Maryland's most prized forested wetlands in the Mattawoman and Parkers Creek watersheds.

The impact isn't immediately obvious because the new lines make use of existing towers and rights-of-way. But the towers were put in place before stringent environmental regulations - when the best path appeared to be directly down the Mattawoman.

Cables are strung on only one side of the towers. On that side, trees are permanently cleared to create a safety zone. On the side without cables the trees grow close, with wetlands, the floodplain and streambed meandering at their feet.

"When I started the research, numbers that were really astounding jumped out at me," Klein said. "I look at wetlands applications all the time and hadn't seen a number that high in some time."

The proposal includes the permanent conversion of approximately 118 acres of forested nontidal wetlands to scrub-shrub wetlands, temporary impacts to approximately 60 acres of nontidal wetlands and 1,722 linear feet of stream, and the permanent clearing of 11 acres of floodplain.

Bonnie Bick of the Mattawoman Watershed Society has worked for decades to promote land use decisions that would protect the creek and its high-quality tributaries. "It's always a fight against a thousand cuts, but MAPP is more like a machete," Bick said.

The MDE's review will include impacts to the wetlands, waterway and floodplain, as well as potential water quality impacts to designated high-quality Tier II waters in the Mattawoman Creek and Zekiah Swamp.

Tier II waters represent the best of Maryland streams, which exceed minimum water quality standards and boast healthy communities of fish and aquatic insects. Tier III streams are even better - but none exist in Maryland.

MAPP will also affect Parkers Creek, which, like the Mattawoman, has received much attention for conservation and its relatively pristine condition. A large converter station is proposed near its headwaters.

Lora Harris, a research professor at the University of Maryland Center for Environmental Science, studies Parkers Creek to learn about the role of wetlands in processing nutrient and sediment loads on restored streams.

"We use Parkers Creek as a pristine control site because there are very few watersheds left like this in the Coastal Plain," Harris said. "This proposal is so big that it was an alarm bell."

Approximately 60 individuals and groups commented on the proposed permit. The MDE has asked PHI for additional information and extended the decision date to Sept. 9.

At the federal level, the U.S. Army Corps of Engineers is reviewing a wetlands permit for the western portion of the route, but it is unclear whether public hearings will be part of the process.

Jubic understands the concerns but points out that the wetlands will be converted to a new form, and not lost entirely. "Wetlands will still be wetlands, just not forested," Jubic said. "And we have quite a bit of mitigation set up to offset the impact, some within the most sensitive portions of the Mattawoman and some outside of it."

Jubic said that great care is taken to manage rights-of-ways to protect plants and wildlife. Preventing the growth of tall trees, which pose safety hazards, is the major concern. "If we can leave the vegetation in place without interfering with the power lines, we'll leave it in place. It doesn't have to be a mowed lawn," Jubic said.

The U.S. Department of Energy is drafting an environmental impact statement for the portion of MAPP that runs from the Patuxent River through the Bay and Choptank River to its end point in Delaware. The results will be used to consider a federal loan for the project.

For the underwater route, two sets of cables will be buried across 39 miles of the Bay and Choptank River. High pressure water shot from an underwater plow will create the parallel trenches, 6 feet deep and 2-3 feet wide. PHI considers the project corridor to be 80-100 feet wide.

The company has conducted studies of the Bay and Choptank River and investigated the use of such cables in other settings. The research shows that more than 75 percent of the sediment disturbed by the process falls back into the trench or beside it.

They've also found no significant impacts from electric magnetic fields emitted from the cables. The sediment temperature will be slightly higher up to about 20 feet from the cable, Jubic said, but not enough to pose a problem.

"The results show that we can install and operate this cable without an adverse impact on the Bay, the fish and organisms that live in the Bay," Jubic said.

The Choptank portion of the route was planned to avoid most oyster reefs, and mitigation projects will be used to offset the six-tenths of an acre that will be disturbed. Part of the area includes historically mapped reefs that actually contained no oysters.

Don Meritt of the UMCES Horn Point Laboratory worked with PHI to survey the locations of oyster beds in the Choptank River. "We explored several routes for this cable and in virtually every case that we encountered any significant oyster habitat, PHI re-routed away from it. I can't imagine anybody doing a better job than they've done with this," Meritt said.

Roy Meredith, president of the Dorchester County Seafood Harvesters Association, has doubts. He isn't convinced that PHI studies are thorough or objective. Meredith questions the impact of drifting sediment on oyster beds and underwater grasses and thinks the cable may create more challenges for struggling watermen.

"There are too many unknowns," Meredith said. "They say the impact will be minimal, but what's minimal to them could be major for us."

He also worries that mistakes will not be fixed. "Once this is done, once they put a billion dollars into this, you aren't stopping it," Meredith said.

The Chesapeake Bay Program, a state-federal partnership that directs Bay restoration efforts, has not commented on how the cable may or may not affect aquatic resources.

In written comments to the Department of Energy, the Chesapeake Bay Foundation noted that "citizens and government representatives accountable for meeting specific Bay health goals must not bear the burden of addressing additional pollution problems born from this initiative. It is imperative the DOE provides certainty to avoid further damage to a system already dangerously out of balance."

Towers and transmission lines would increase in the rural viewsheds of the lower Eastern Shore, including Wicomico and Dorchester counties in Maryland and Sussex County, DE, where agro-tourism and outdoor recreation are popular. The impact includes a site on the Captain John Smith Chesapeake National Historic Trail at the town of Vienna, MD, which is already saddled with transmission lines along the Nanticoke River.

"The whole economic development strategy for the town is to keep this segment of the Nanticoke River as close to what it would have been when John Smith was here, to promote eco-tourism," said mayor Russ Brinsfield. "But coming up the river like Smith did, you'd see those power lines draped across it. It's massive."

Libby Nagel, owner of five Dorchester County farms and founding member of Dorchester Citizens for Safe Energy, laments the disruption of the landscape in a county that has worked for years to preserve its rural environment. She is also concerned that establishing the first high voltage power line on the Delmarva Peninsula will make it easier to approve more development.

When asked to sell part of her land for a right of way, Nagel declined. "There is no amount of money that would convince me," Nagel said. "I don't think they understood that."

If the need for MAPP is truly established, Nagel said the lines should go underground.

Brinsfield agrees. Brinsfield co-chaired a committee established to provide citizen feedback on the proposed route. "Our position was that if the need was verified by all parties, the only way we would accept it is if it was buried all the way," Brinsfield said.

PHI estimates that burying the cable on land would increase the cost by $150 million to $300 million.

As currently proposed, MAPP will cost $1.2 billion. The 50 million electricity consumers throughout the PJM region would pay the tab, as well as a 12-14 percent rate of return to PHI that the federal government authorizes for projects that address reliability concerns.

Although energy prices are likely to rise everywhere, Jubic said that MAPP will help everyone access less expensive energy and encourage competition between generators. As a result, some parts of the electric bill may actually decrease and keep the rise in check, he said.

Klein believes that could give coal-fired power plants an advantage. "The concern is that if you make this cheap energy more available, doesn't it also increase impediments to green energy, which is more expensive?" Klein said.

Critics of MAPP have suggested addressing the power issues by adding new generation on the Delmarva, especially based on renewable resources like gas or biomass. But among the solutions proposed to PJM, none have been for new generation.

A northern route could carry power onto the Delmarva from north of the Bay by adding capacity to existing lines, similar to the process proposed for southern Maryland. PHI discarded that option for its expense and the complicated process of crossing multiple states. Jubic said that adding a southern route also provides backup if the existing northern supply lines were to fail.

Twenty-six Maryland organizations asked Gov. Martin O'Malley to spearhead a comprehensive energy plan for the state so that MAPP could be fully weighed against other concerns and solutions for short– and long-term energy needs.

As the case moves before the Maryland Public Service Commission, 12 organizations have also asked for an independent scientific review of the proposed underwater cable.

"The PSC doesn't have the resources for this kind of analysis. So before precedent is established, before the PSC has to make a decision on inadequate information, let's get our best people looking at this and see if MAPP is truly in the best interest of the state," Klein said.

For perspectives on MAPP, visit www.powerpathway.com and www.ceds.org/mapp.html.