Island water source turning salty

 

By LIZ MITCHELL | Beaufort Gazette

Facing the threat of saltwater intrusion into local drinking water sources, South Carolina and Georgia officials are cooperating to manage those underground reserves.  But some are worried current conservation efforts and future restrictions might not be enough to preserve the Upper Floridan Aquifer, a resource buried 150 to 300 feet deep that already has been tainted with enough saltwater to close four wells on Hilton Head Island since 2000.

Studies have shown the saltwater problem began with development in Savannah that saw the city pumping millions of gallons of water a day from the aquifer.

By 1960, the water table had dropped 20 feet, and the groundwater flow shifted direction, according to Dr. Richard Spruill, a professor of hydrology at East Carolina University who has helped conduct some aquifer studies on Hilton Head.

Instead of fresh groundwater flowing north and discharging into salty Port Royal Sound, it moves south toward Savannah.

That means saltwater is seeping into the aquifer and contaminating fresh water.

If the pumping doesn’t slow in the Savannah area, saltwater intrusion will continue.

“Both states agree that our objective is … to agree on the amount of groundwater we can safely pump without making the saltwater problem any worse,” said Dean Moss, general manager of the Beaufort-Jasper Water and Sewer Authority, who also sits on a bi-state task force evaluating future water use.

“If we can stop pumping altogether, within a couple hundred years, maybe the saltwater can push out, but that is not going to be possible.”

Instead, officials hope to stop saltwater from intruding farther.

While the goal is clear, the means to achieve it is not.

“But what kind of pumping reductions it will take to do that, we don’t know yet,” Moss said.

Read on here.