Savannah River deepening hinges on never-before-used system

Testing started mid-March

Oxygen injectors online for Savannah River

SAVANNAH, GA (WTOC) - The $1 billion harbor deepening project has one more major milestone to cross before being completed, and it hinges on technology never used on the scale it’s being used now.

The Army Corps of Engineers must oxygenate the river so the sturgeon that swim along the bottom can survive. If the Corps can’t, the harbor deepening project is dead.

They’re currently in a testing phase for the new Oxygen Injectors on the Savannah River that started March 14 and continues for 59 days. The Corps must prove it can pump enough oxygen to the riverbed, so the fish can survive once the river is five feet deeper. The Corps says the injector sites will satisfy the environmental concerns. A court settlement forces the Corps to prove it can do this before deepening the inner harbor.

“Those pumps move roughly 10,000 gallons a minute. The plant moves about 30,000 gallons a minute,” said Jonathan Broadie, the chief of Operations and Asset Management Section for the Army Corps. “When three pumps are running, it can fill up an Olympic sized swimming pool in about 22 minutes.”

Broadie is describing the $100 million solution to oxygenating a river that will be five feet deeper once the project is done. Together, the sites will cost about $3 million to run each year.

The process starts in oxygen generators, which turn atmospheric air into 93% pure oxygen.
The process starts in oxygen generators, which turn atmospheric air into 93% pure oxygen. (Source: WTOC)

The project combines oxygen generators normally found in hospitals or mines with something called Speece Cones. The cones are normally found in wastewater treatment plants.

“Each component in this plant exists somewhere in the world. they’re not combined in this fashion anywhere else,” said Broadie. “It really is unique.”

The facility produces 15,000 pounds of oxygen per day. It must inject 12,000 of that into the water. The process starts in the oxygen generator. The machine makes 93 percent pure oxygen from atmospheric air.

The oxygenated air is piped over to Speece cones which mix the river water and oxygen, before injecting it back into the river about 25 feet below the surface
The oxygenated air is piped over to Speece cones which mix the river water and oxygen, before injecting it back into the river about 25 feet below the surface (Source: WTOC)

From there, the water is injected back into the river. The entire purpose of the project is to oxygenate the deepest parts of the river where sturgeons swim. The critically-endangered fish have been around for millions of years.

The Army Corps uses dye to see how much of the oxygenated water reaches the bottom and how much goes to the surface.

“Speece cones have been successful elsewhere but not on this scale,” said Billy Birdwell, a spokesman for the Army Corps of Engineers. “We have studied this technology behind the Speece Cones. We have looked at it very carefully. We are fully confident it will work.”

Oxygen generators (L) and the 4 Speece cones (R) on Hutchinson Island
Oxygen generators (L) and the 4 Speece cones (R) on Hutchinson Island (Source: WTOC)

There are two sites; one is near the ports. The other is farther inland in Effingham County. The facilities will run for the three and a half hottest months in the summer, when oxygen levels are normally the lowest in the water. The injectors are normally used in smaller reservoirs or lakes.

Detractors of the system compare it to putting the river on a respirator.

“The ongoing testing of the oxygen injection system essentially puts the river on life support. We know the river cannot sustain the oxygen it needs without help, so now we see if that help actually works,” said Savannah Riverkeeper Tonya Bonitatibus. “This is a crucial step in the harbor process, and failure to get it right could have drastic consequences. The next few months will be very telling.”

WTOC's Wright Gazaway (L) with Jonathan Broadie (R)
WTOC's Wright Gazaway (L) with Jonathan Broadie (R) (Source: WTOC)

“This is not a respirator. This is not a bubbler. This is dissolved oxygen,” said Birdwell. “It’s putting pure oxygen, fully dissolved in the water and putting it back into the river so that the small amount of oxygen that is depleted for the deepening is replaced. This is good, strong technology.”

The inner harbor deepening is the final phase of the project. The project is set to be completed in February of 2022. The state and Army Corps have said it will take at least $100 million in federal funding each year to finish by then.

Georgia Governor Brian Kemp touts his relationship with the White House, so WTOC asked him what he thought their future commitment might look like.

“I wouldn’t want to speak for them on specifically what their budgeting plans are. That’s got to go through the Congress as well, but I think the money that they put in the proposed budget this year shows they’re commitment to that project and our state,” said Governor Kemp. “It’s a great thing not only for your state but for our country.”

President Trump committed about $130 million in this year’s proposed budget for 2020.

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