Wetlands are to nature what kidneys are to the human body
By using these natural kidneys as filters, a South Carolina county is processing wastewater in an energy efficient manner while leaving the wetlands unharmed.
In Horry County — South Carolina’s fastest growing county with Myrtle Beach as its hub — a sewage disposal system is dumping 450,000 gallons of wastewater a day into wetlands. And the natural settings are thriving.
“Fifty percent of the county is wetlands, so it became a natural alternative to consider,” said Larry Schwartz, an environmental planner with the Grand Strand Water and Sewer Authority, which handles wastewater treatment for the county. “We’re just using the natural filtering ability of the land to renovate wastewater.”
The wastewater is being distributed evenly across one Carolina Bay, an example of the egg-shaped natural depressions unique to coastal regions of the Southeast. These bays, usually filled with peat and shrubs, act as buffers between the uplands and the region’s fragile black-water rivers — so named because they are dark-colored, slow-moving and hold small amounts of dissolved oxygen.
Currently, only one bay is receiving wastewater. But eventually four bays may be used to treat up to 2.5 million gallons a day as the county grows over the next 20 years, Schwartz said.
A series of boardwalks crisscrosses the bay to support distribution pipes carrying the wastewater. Two-inch holes every 15 to 20 feet allow the water to splash on rocks and disperse evenly across the bay.
The wastewater has been treated to secondary levels before it enters the bay, Schwartz said, meaning 85 percent of all organics and wastes have been removed. To finish cleaning the water using man-made treatment systems, large amounts of energy are required.
“But in this case we’re using energy from the sun,” he said. “That’s the beauty of it — the system is cost-effective and energy-efficient.”
A dozen government agencies at both state and national levels are involved in the project. Two biologists work full time testing the water quality and studying the natural habitat, Schwartz said.
“Our goal is to maintain the value of the natural communities in the bays and manage them so they remain the same — and in the process achieve advanced wastewater treatment,” he said.
The project has generated plenty of interest from other states, including some that hope to construct their own wetlands for similar purposes, said Schwartz, who averages at least one tour a week of the county’s wastewater system.
“It’s a major new way to do things,” he said. “With wetlands, if they are selected and managed properly, there is no reason not to use them.”