ALEXANDRIA, Va. (WUSA) -- Monday, the power plant in Alexandria on the Potomac River officially shut down. The Gen-On Potaomac River Generating Station was called the Mirant Power Plant for years.

Under a deal with the city of Alexandria, Gen-On agreed to shut down the plant by Monday. 

It should alleviate health and environmental concerns in the area.

In exchange, the city will return about $32 million to the company.