A decision by a state environmental board will be a death knell for plant and marine life in the Savannah River and could jeopardize a major source of drinking water for the area, according to some legislators.
Sen. Tom Davis, R-Beaufort, lambasted the S.C. Department of Health and Environmental Control board's decision in November to reverse itself and approve Georgia's application to deepen the Savannah River. Georgia's water-quality permit is being challenged by South Carolina's Savannah River Maritime Commission and environmental groups.
Davis, speaking Thursday alongside Sen. Larry Grooms, R-Berkeley, in a weekly press conference sponsored by SCETV, said Georgia received an economic boost from the deal, while South Carolina faces an environmental bust.
Davis and Grooms say dredging the river will destroy surrounding freshwater wetlands and kill fish and other aquatic species by depleting oxygen levels in the river.
Georgia said it or the U.S. Army Corps of Engineers would pay for untested gear to maintain oxygen levels. Georgia also agreed to protect about 1,600 acres of saltwater marsh it owns in South Carolina and meet federal requirements to protect the endangered short-nosed sturgeon.
Davis and Grooms argue the marsh is already protected and there's no evidence the oxygen pumps work on such a large scale.
"It's essentially a respirator for the river," Grooms said. "They would kill the river and bring it back to life by pumping oxygen back into the river to keep the fish alive."
Davis worried dredging could also potentially "puncture" the freshwater Upper Floridan Aquifer, a major source of drinking water for Hilton Head Island.
"We're already seeing saltwater intrusion (into the aquifer) on Hilton Head. Dredging the Savannah River from 42 to 48 feet would exacerbate the problem," Davis said.
The Hilton Head Public Service District agrees, saying dredging will cause further degradation of the aquifer, spokesman Pete Nardi said.
The aquifer accounted for 27 percent of the district's water supply last year.
However, Dean Moss, chairman of the S.C. maritime commission and former general manager of the Beaufort-Jasper Water & Sewer Authority, said dredging would not have much of an impact on local drinking water.
Dredging will scrape away portions of a "quasi-impervious" clay layer that separates the aquifer from the river bottom. That will increase potential for longer term spikes in salinity in the aquifer, but is mostly an issue for Georgia, Moss said.
Overall, though, Moss has criticized the dredging approval, saying previously that federal and state regulators have not evaluated feasible alternatives.
Follow reporter Tom Barton at twitter.com/EyeOnHiltonHead.