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Muddy Run Pumped Storage Facility is a pumped-storage hydroelectric plant that is owned and operated by Exelon Power, a business unit of Exelon Generation. It is used to generate energy for peak demand which usually occurs during the morning and early evening hours.

The 8-unit power station provides 1,070 megawatts (MW) of electricity by damming the Muddy Run ravine from its mouth. The station's output is critical to meeting the dynamic peak electricity demands on the area's regional power grid on hot summer afternoons. To generate energy, the water in the upper reservoir at Muddy Run is used to fuel the turbines, flowing into the Conowingo Pond, a 14-mile stretch of the Susquehanna River in Maryland. As energy demand decreases, at night, the units are reversed and used as pumps to fill the upper reservoir for subsequent peak-demand periods.

Muddy Run has provided electric power to the regional transmission system since commercial operation began in 1966. At the time, it was the largest pumped-storage hydroelectric power plant in the world. The general plant configuration remains the same as the original construction, however, the turbines and generators have been recently refurbished.


Exelon Generation's culture and business practice make us safety-first

All Exelon Generation facilities employ sophisticated emergency response plans to protect public health and safety. Plans are reviewed and approved by state governments and federal regulatory agencies. Emergency planning includes coordination with local and municipal officials, and thousands of volunteers and first responders.

To protect the safety and health of our employees, contractors, customers and communities, we've implemented a number of initiatives to promote safe behaviors both on and off the job.

Exelon has a safety behavior observation program and focused initiatives on areas of high risk. We offer safety training, which is integrated with leadership development programs for supervisors and managers, as well as new employee orientation. And the safety peer group identifies successful pilot programs or new practices that can then be adopted by the entire organization.


License renewals mean clean, zero-carbon energy well into the future

Exelon Generation received a 40-year license from the Federal Energy Regulatory Commission (FERC) to continue operating Muddy Run Pumped Storage Facility, allowing the hydroelectric plant in Drumore, PA, to provide clean, renewable electricity to thousands of households in parts of south central Pennsylvania and northern Maryland through 2055.  


Supporting the local economy

Exelon Generation spends more than $40 million annually to operate and maintain both Conowingo and Muddy Run and pays nearly $5 million in property taxes annually. The plants have a shared workforce of over 60 Exelon employees.


We live here too, and we're good neighbors

Muddy Run aims to be a good neighbor and is very active in the local community.

  • Charitable Giving & Volunteering. Muddy Run and its employees give generously to the community through a variety of charitable activities including the local United Way chapters, the Airville Fire Company and Operation Warm.
  • Recreation. The Muddy Run Recreational Park contains a 100-acre lake surrounded by 700 acres of wood and field areas. The habitat is home to Eastern blue bird and other songbirds, bald eagles, ducks, geese and white-tailed deer, among many other creatures. The park provides family recreational needs, including camping, biking, hiking, boating and fishing. The park includes a campground and a boat launch with electric and rowboats available.



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About this facility