Decommissioning the Benning Road Power Plant

As of June 1, operations at the Benning Road Power Plant have ceased as announced by Pepco Energy Services (PES), a wholly owned subsidiary of Pepco Holdings, Inc., which has owned and operated the power plant since 2000. The power plant is located on the western most portion of the Benning Service Center site, where it occupies approximately 25 percent of the facility's 77 acres. Preparations for closing the power plant have been underway since 2007. As part of the closure, the plant and adjoining areas will be cleaned, secured, and maintained in accordance with District of Columbia and Federal environmental regulations.

What was the Benning Road Power Plant?
The power plant was built in 1906, and provided Pepco's first system-wide electricity supply to the District of Columbia and nearby Maryland suburbs. Over the years, the power plant operated and subsequently retired several different generating units, reflecting advances in technology and operating on different types of fuel. Two oil-fired steam turbine units, installed in 1968 and 1972, provided a combined 550 MW of electricity; enough to meet the needs of around 180,000 homes. Designed to operate a limited number of days each year, these units operated an average of 10 to 15 days annually to ensure reliable power to Pepco's customers during periods of peak electricity demand.

How will the Power Plant Decommissioning be implemented?
As of June 1, operations at the Benning Power Plant have ceased as scheduled and PES has placed the plant into an idle condition termed a "Cold Closure". The next steps are to clean and secure the plant and portions of the property as required by District of Columbia and Federal environmental regulations and good management practices. The power plant decommissioning proceeds during the course of the next several months.

What is "Cold Closure"?
Cold Closure is defined as a condition in which utility service to the Power Plant is disconnected, and no longer operable. Cold Closure is intended to require only essential maintenance until the plant is completely decommissioned. As a part of Cold Closure, all systems that are subject to failure due to freezing will be decommissioned, and materials used in power plant operations will be removed.

What happens during the Closure?
The first step for the closure of the Benning Power Plant is to shutdown the two steam turbine units, the auxiliary boilers, the preheat generator, and all related equipment. Next, weatherproof fire suppression equipment will be installed as required by the District of Columbia Fire Marshal. Then, the cooling tower structures will be drained, dismantled and removed.

PES will follow all environmental regulatory requirements established by the District of Columbia and federal agencies. These requirements fall into several categories including air pollution control, water pollution control, solid and hazardous waste management, above ground tanks, and several requirements pertaining to maintenance of buildings (e.g., polychlorinated biphenyls (PCBs), asbestos, lead-based paint, mold). Specific closure activities under each of these categories are discussed below.

• The plant will no longer create air emissions; therefore, the air permit issued by the District Department of the Environment will be modified to exclude the power plant and cover only sources of air emissions at the Benning Service Center.

• Stormwater discharges will continue to be managed under the EPA-issued National Pollutant Discharge Elimination System (NPDES) permit. However, process water discharges from the plant (e.g., cooling tower blow down) that are currently covered under the NPDES permit, will no longer occur.
• The water intake structure, regulated by the United States Army Corps of Engineers (USACE), will be left in place. All other river water inlets for the plant will be isolated (plugged) so that water can neither enter nor flow out of the plant.
• The use of the sanitary sewer system will discontinue; therefore, the power plant's connections to District of Columbia water system will no longer be required and will be discontinued.

• Miscellaneous containers of hazardous materials, universal wastes, and lead-based paint (LBP) will be inventoried, managed, and disposed of in properly permitted off-site disposal facilities.
• Any PCB-containing equipment or structures identified will be inventoried, and equipment with PCB-containing materials will be removed and disposed of in properly permitted off-site disposal facilities.
• LBP locations will be inventoried; and as closure activities remove structures or equipment containing LBP, these items will be managed or remediated in accordance with lead paint regulations.
• Any asbestos will remain in place. Ongoing inspections and maintenance will be performed to manage asbestos until demolition of structures containing asbestos is warranted.

• Fuel oil tanks and all other process tanks will be emptied, cleaned, dismantled and removed.

• The need for roof repairs and maintenance will be evaluated, and repairs will be made as needed to prevent leaks.
• All containers and piping containing oil and other fluids will be emptied, cleaned and removed or properly abandoned.

Does the Power Plant Closure affect the Service Center?
No, the Power Plant occupies approximately 25 percent of the facility's 77 acres. The Service Center occupies the largest part of the property, and accommodates about 700 Pepco employees. Service Center employees work in maintenance and construction of Pepco's electric transmission and distribution system; system engineering; vehicle fleet maintenance and refueling; and central warehouses for all the materials, supplies and equipment needed to operate the Pepco electrical distribution system. The closure of the Benning Power Plant only affects the plant area.

How does this affect the Benning Consent Decree?
The Benning Consent Decree is a legal agreement between the District of Columbia's Department of the Environment and Pepco and PES that requires an assessment of environmental conditions known as a Remedial Investigation/Feasibility Study (RI/FS), at the Benning Road site and adjacent areas of the Anacostia River. The RI/FS will continue on schedule as the power plant decommissioning plan is implemented.

For more information contact:

Fariba Mahvi
Lead Environmental
Engineer & Benning Road
Project Manager
202-331-6641

Donna Cooper
Vice President
District of Columbia Affairs
202-872-2477