Power Generation, Transmission, and Use

Markets, Regulation, and Oversight

Impacts of Power Generation and Transmission

Looking Ahead


CEIR Report Map


Maryland Power Plants and the Environment (CEIR-18)

4.3 Impacts to Terrestrial Resources

Maryland’s physiographic diversity, geology, and climate have produced a variety of eco-regions that foster numerous, and sometimes unique, habitats ranging from ocean barrier islands in the east through salt marshes, fields and forests of the coastal plain, into rolling piedmont hills, and on to forested mountains with remnant alpine glades to the west. While human activities (agriculture, urban/suburban development, etc.) have altered all of these areas to some extent, the majority of the landscape continues to possess a wide variety of habitats that support diverse communities of flora and fauna. Many of these communities help define their regions, and may contain rare, threatened, or endangered species.

The State of Maryland implements a suite of regulations (COMAR Titles 08, 26, and 27) that afford protection to habitats and species in terrestrial and wetland environments:

The construction and operation of power generation facilities can have significant effects on terrestrial environments, including wetlands. Power plant infrastructure, including production units, pipelines to transport water, oil, and natural gas, electrical transmission lines, and roadways and railways, can occupy extensive areas on the landscape. Notably, these facilities can:

New generation facilities may be constructed entirely within an area that is already developed or may require clearing a significant number of acres of natural habitat. Recent examples highlighting the scope of impacts to terrestrial resources include two projects under construction in Southern Maryland. The Project Site for the Keys Energy Center (KEC) combined-cycle, natural gas-fired plant in Prince George‘s County is a 180-acre parcel of land formerly used for a sand and gravel mining operation. Approximately 30 acres of the parcel will be used for the permanent electric power generation and support facilities. The site is adjacent to PEPCO’s existing 500 kV transmission line right-of-way located on the western side of the property. The associated gas pipeline will be constructed on the vegetated side of the existing 500 kV transmission line for the gas pipeline, which requires clearing many acres of existing forested habitat. The gas pipeline route crosses sensitive areas such as wetlands and streams, including the headwater streams of Zekiah Swamp.

The Mattawoman Energy Center Project Site is a previously cleared 88-acre plot on Brandywine Road in Prince George’s County. Linear facilities associated with the Project include an approximately 10-mile-long reclaimed wastewater pipeline to bring treated effluent from Piscataway WWTP, an approximately 7.4-mile-long natural gas pipeline, and a 2.3 mile generation lead line extending from the power plant site north to PEPCO’s Burches Hill to Talbert 230 kV PEPCO transmission line. The proposed substation site is located on Cherry Tree Crossing Road, adjacent to the PEPCO 230 kV transmission line corridor, which contains approximately 8 acres of predominately upland forest. The gas pipeline will widen the existing gaps associated with the PEPCO/SMECO transmission line ROW, and will require clearing many acres of forest. A portion of the ROW, at the Mattawoman Creek crossing, runs directly adjacent to the proposed gas pipeline route for the Keys Energy Center. The last 1-mile segment of new ROW required for the gas pipeline runs parallel to Jordon Swamp.

Impacts from new generation projects on Maryland’s landscape in the future will also depend on the mode of power production. Power plants that use traditional resources such as coal and natural gas are generally confined to an intensively developed installation with the exception of the associated linear facilities that may be needed, whereas renewable energy projects using wind turbines or solar panel arrays may occupy hundreds of acres. There are more than 10 proposed solar generation facilities throughout the state that have recently undergone review by PPRP. Great Bay Solar is a recently approved project that will be constructed on approximately 1,000 acres near Princess Anne in Somerset County and involved coordination with Critical Area Commission. The facility will be constructed in two phases, with the capability to generate up to 150 MW of power upon the completion of the second phase. The Project is scheduled to begin operation by the end of 2016 and is anticipated to be in operation for a minimum of 25 years.

More than two thousand miles of electric power transmission line and natural gas pipeline rights-of-way are located throughout Maryland. Constructing and maintaining these rights-of-way creates long, mostly linear, corridors that are often quite different from the surrounding environment. These corridors can affect nearby areas, including terrestrial habitats and wetlands, in a variety of ways, either temporarily during construction or over the long term. To provide public review and to ensure that environmental and other concerns are addressed, CPCN applications are required for new corridor construction and for modifications in existing corridors.

Transmission line corridors may affect specific environmental features, alter the landscape over long distances, or change the way people use nearby residential, commercial, or agricultural land. For each right-of-way modification or construction proposal, PPRP reviews the potential impacts of the proposed project on streams, floodplains, wetlands, forests, rare species, historical and archeological sites, and surrounding land use. Quantitative comparisons of alternate routes are derived from digital maps, aerial photographs, and other data sets, and supplemented by field inspections. The purpose of these comparisons is to identify the types of impacts that may occur along each possible corridor and to find the route with the lowest overall impact. Where undesirable impacts cannot be avoided, recommendations may include compensating for the damage and/or maintaining certain conditions in the corridor after construction.

PPRP’s role in the CPCN process is to facilitate compliance with Maryland’s environmental regulations and natural resource management objectives. Environmental laws affecting Waterways Construction, Water Quality and Water Pollution Control, and Erosion and Sediment Control require best management practices (BMPs) to eliminate or minimize disturbance in and discharges to Maryland waters. These BMPs are uniformly included as conditions to a CPCN. However, a CPCN can also recommend specific conditions to avoid, minimize, or mitigate impacts on natural resources when the effects of the proposed project are particularly compelling. Under these circumstances, conditions placed on a CPCN to mitigate impacts to wetlands, forests, and sensitive species habitats may often be more stringent than requirements under the individual statutes.