U.S. Army Corps of Engineers, Savannah District, has completed tests on its Hutchinson Island dissolved oxygen injection system, as an environmental mitigation aspect of the Savannah Harbor Expansion Project.
Preliminary assessments of the testing data indicate the plant operates as designed and produces results as anticipated or better, reported the Corps.
“We’ve completed the testing and data-collecting phase and we are still making progress in the analysis of the data, and plan to release a final report in August,” Bryan Robinson an engineer with the Corps who oversaw the tests, said. “Our general impression right now is that the tests indicate the system is performing better than expected in the three primary aspects of the tests.”
Preliminary analysis shows the river retains dissolved oxygen in the water column on average better than anticipated.
Specialists with LG2 Environmental Solutions of Jacksonville, Florida, conducted the tests on 59 consecutive days.
This schedule covered two complete lunar cycles to determine the effects the different tidal levels would have on the distribution of super-oxygenated water in the river. In addition, they conducted multiple tests using red dye to show the distribution in the water.
Injecting super-oxygenated water into the Savannah River helps mitigate for the loss of oxygen as the harbor is deepened from its current 42 feet to 47 feet.
The Savannah Harbor Expansion Project, also known as SHEP, will provide greater opportunity for modern container ships to enter and leave the port with greater loads and with fewer tidal restrictions.
The SHEP will benefit the American economy by a ratio of 7.3 to 1. That means for each $1 spent on deepening the harbor, the U.S. economy will see a net benefit of $7.30, or a net benefit of $282 million per year.
The Corps of Engineers uses Speece cones, giant steel cones which use river water, mixing at high pressure to dissolve pure oxygen into the water. The machinery then returns the super-oxygenated water to the river where tides and currents distribute it naturally.
Pure oxygen is extracted from the air at the Hutchinson Island location. As an automated plant, it requires little human involvement.
The system will be used mostly during the hot, summer months when oxygen levels in the river are naturally lower.
The successful demonstration of the dissolved oxygen injection system is a requirement before dredging of the inner harbor can begin. The outer harbor, from approximately Fort Pulaski to 19 miles into the Atlantic, was completed in March 2018.
The construction of a second dissolved oxygen injection system in Effingham County, Georgia, nears completion.