Whether or not the Savannah River can be deepened along the lower Georgia-South Carolina border depends on how well 12 oxygen injection machines work.
The devices, known as “Speece cones,” are necessary because the Army Corps of Engineers believes dredging 36 miles of the river an additional six feet could reduce the amount of oxygen in the water to dangerously low levels.
“We have known all along that the dissolved oxygen in the water will go down a bit,” Corps of Engineers spokesman Billy Birdwell said. The cones would be used to pipe oxygen into the river during hot, dry summer days when the dissolved oxygen level is lower than normal.
However, they have never been used in as extensive a situation as Savannah River. And that has environmentalists concerned. In fact, the cones were the key part of a lawsuit that overshadowed the project for nearly 18 months until a new settlement was approved by a federal judge last week. The settlement would require the cones to be successfully tested at least twice before dredging can begin.
“We need to make sure that we do a lot of due diligence on whether it’s possible for them to work or not,” Coastal Conservation League executive director Dana Beach told South Carolina Radio Network.
The worries expressed by Beach and other environmental groups are that extremely-low oxygen levels could create a catastrophic situation for fish in the river. “We could see the Savannah become essentially a dead river,” he said. “What we tried to do in the settlement was to put enough failsafe measures in it that… if these Speece cones don’t work, we’ll know it in advance.”
But the Corps is confident the machines will work, saying the cones were successfully tested in 2007 and that similar systems are used in smaller rivers around the world.
Birdwell said there will be 12 machines placed at two locations along the river— above the Port of Savannah at Plant McIntosh and another below it at Hutchinson Island.
The Corps of Engineers says it would cost $14 million to install the system and an extra $1.2 million per year to maintain it. The Corps and Georgia Ports Authority would split the cost under a current cost-share agreement.