By Justin Wan, Sioux City Journal.

SIOUX CITY | Sioux City Council members gave favorable reviews Monday to a $9.3 million project that will allow the city to capture, clean and compress gas at its wastewater treatment plant, then sell it as renewable fuel.

The council voted 4-0 Monday to enter into an agreement with a West Des Moines-based firm for engineering and planning services for the project.

That vote followed approval of a similar agreement for planning on a project that will include about $16 million in other maintenance and upgrades that will eventually increase the capacity of the treatment facility.

"This is a huge deal," Mayor Bob Scott said of the renewable fuel project.

The project, which would take about two years to complete, will put in place a system to capture, clean and compress a gas created as a byproduct during the anaerobic digestion process the city uses to break down raw sludge to turn it into biosolids.

Once the proposed project is complete, the gas would either be used in the city's fleet of vehicles or be channeled into a nearby MidAmerican Energy or Northern Natural Gas pipeline to be sold as renewable fuel.

Mark Simms, Sioux City's utilities director, said the wastewater treatment plant in Des Moines, Iowa, also cleans its gas, along with about a dozen facilities around the nation.

"We’re not first in line for this, but we would be one of the few in Iowa or the region that would be doing this," Simms said.

Simms told the council the gas would have about 10 times the market value of natural gas, and the project would pay for itself in about 2 years based on forecasts.