The Lingan coal-fired power plant outside New Waterford was evacuated this morning because of a fire, according to Nova Scotia Power.
The power company said in a statement that a system operator was alerted electronically to an issue in a silo around 8 a.m.
The silo is where flue gas is injected with powder-activated carbon, which captures mercury in the gas.
The operator saw smoke, sounded the plant's emergency alarm and called 911.
The volunteer fire departments from Glace Bay and Scotchtown responded.
NSP said the plant's emergency response team worked with the firefighters to put out the fire with dry chemical extinguishers.
The workers were back in the plant within an hour, the company said. Minor damage is reported to the silo.
An investigation is underway into the cause.