After nearly three years, construction is almost complete on the $375 million baghouse at Plant Gorgas in Walker County.

Workers have started installing more than 20,000 filter bags – each one 26 feet long – that are the heart of the baghouse. The baghouse structure itself stands 11 stories tall and takes up as much space as three and a half football fields. Some 3,100 tons of structural steel and 800,000 feet of cable have gone into the project.

The baghouse’s primary purpose is to capture minute amounts of mercury released during coal combustion. A baghouse is also under construction at Plant Gaston in Shelby County. Both are required to comply with the latest round of federal environmental regulations.

The Gorgas baghouse is unique in the Southern Company generating fleet, in that one baghouse will be used to control the emissions from three generating units.

“This has been a great project. We’ve had close cooperation from everyone involved – from the engineering and design folks, to our contractors, to all our plant personnel,” said John Banger, asset manager at Gorgas and coordinator of the baghouse project.

During the height of construction in fall 2014, about 450 contractors were working at Gorgas on the baghouse project. About 280 contractors are still at the plant.

In addition to construction of the actual baghouse, workers are completing the ductwork needed to connect the baghouse to other, existing environment controls. They include the plant’s scrubber, completed in 2008, and the selective catalytic reduction technology, or SCR, completed in 2002.

The scrubber controls sulfur dioxide and emission of particulates, while the SCR reduces nitrogen oxides. In all, since the late 1990s, the company has spent close to $1 billion at the plant to meet stricter federal environmental mandates.

“Plant Gorgas is an important part of our generating fleet and the Walker County economy. These investments keep the plant viable for years to come,” said Valerie Wade, Gorgas plant manager.

The Gorgas baghouse is expected to operational by the end of the year. The baghouse at Plant Gaston is expected to be complete in early 2016.

Gorgas baghouse facts

• Expected commercial operation – December 2015
• Projected cost – $375 million
• Structural steel – 3,100 tons
• Cable – 800,000 feet 
• Number of construction workers at peak – 450
• Alabama companies involved – National Steel City LLC, Dunn Building Co., Russo Corp., Saiia Construction Co.
• Union locals involved – Boilermakers, carpenters, ironworkers, operating engineers, pipefitters, electricians, sheet metal workers, laborers, painters, insulators

Plant Gorgas facts

• 1,250 acres
• 300 employees
• $18 million annual payroll
• Three generating units
• 1,100 megawatts nameplate capacity (enough energy to supply 220,000 homes)