Mid-Atlantic Power Pathway Transmission Line Permitting Project

Client: Pepco Holdings, Inc. (PHI)

Location: Washington, DC and Maryland

Summary: The Mid-Atlantic Power Pathway (MAPP) Project is a 500 kilovolt (kV) transmission line (landside Southern Maryland) and 640-kV DC (waterside & Eastern Shore), proposed by Pepco Holdings, Inc. (PHI) to improve reliability and increase energy imports into the Mid-Atlantic Region. PJM, the transmission grid operator for much of the East Coast, has determined that increased demand for electricity in the Mid-Atlantic region, including Washington, D.C. and Southern and Central Maryland, will lead to reliability problems, including brownouts and blackouts, in 2011 or 2012. PJM approved MAPP in October 2007 as a transmission line that can lessen or prevent a majority of the reliability problems PJM identified in those regions.

As part of the 230-mi MAPP project, from Possum Point, VA to Salem and Hope Creek, New Jersey, Cardno ENTRIX is responsible for collecting all environmental baseline data and supporting the client in acquiring all environmental approvals for routing and siting a corridor across Chesapeake Bay and through Dorchester County, Maryland, much of which is designated for preservation at the federal and state levels. Dorchester County also supports significant habitat for the Delmarva fox squirrel and bald eagle. Further, Dorchester County is rich in cultural resources, including the newly approved Harriet Tubman National Scenic Park. Baseline data are compiled using GIS database tools. Data layers include project-specific and public data, including proposed right-of-way boundaries and construction impact areas; route-specific LiDAR data; wetland boundaries; T&E species habitat; cultural resource locations; and the locations of protected lands.

Because a plurality of view on environmental and socioeconomic issues have been raised by the regulators and the public, Cardno ENTRIX is using a multi-criteria decision analysis approach to evaluate potential corridors and routes across the lower Eastern Shore of Maryland. This approach, which includes input from local stakeholders on the relative weights of environmental variables, will be followed by a detailed Alternatives Analysis to evaluate potential corridors, routes and construction methods in order to identify a preferred ROW across the Bay and Dorchester County.