Hilton Head Public Service District (PSD) has been forced to take another of its Upper Floridan Aquifer wells out of production due to saltwater intrusion into the freshwater portion of the aquifer. The approximately 150-foot-deep well, known as the Union Cemetery Well, is located near the intersection of Union Cemetery and Dillon roads. There will be no interruption in customers’ water service due to the shut-down.
Hilton Head PSD now has lost 10 drinking water wells to the phenomenon of saltwater intrusion into the Upper Floridan freshwater aquifer since 2000. Only two of the utility’s four remaining Upper Floridan freshwater wells are currently unaffected by saltwater intrusion.
“The PSD’s Union Cemetery Well is yet another casualty of saltwater intrusion into the freshwater aquifer here on Hilton Head Island and serves as a reminder of the fragile state of our precious water resources,” said PSD General Manager Pete Nardi. “We continue to have ample supply for our customers, but yet again we are reminded of how we all must be stewards of the resource to preserve it for generations of islanders to come.”
It is the PSD’s experience that 40-60% of the annual demand for treated drinking water is used for landscape irrigation. Islanders are reminded that irrigation is restricted to no more than two days a week at all times by local ordinance. Clemson University Extension Service’s “Carolina Yards” program is a great resource for residents to learn more about watering wisely and creating sustainable landscapes. Learn more at: https://www.clemson.edu/extension/carolinayards/. The island’s golf courses do not irrigate with drinking water. They instead utilize the island’s pioneering recycled water system to irrigate using highly treated effluent from our wastewater treatment plants.
The majority of Hilton Head PSD’s drinking water supply comes from its Reverse Osmosis (RO) Drinking Water Treatment Facility on Jenkins Island, which treats brackish groundwater from the approximately 600-foot-deep Middle Floridan Aquifer. The PSD also utilizes an Aquifer Storage & Recovery (ASR) Facility to store treated drinking water in the brackish portion of the aquifer during the winter months of low demand and then withdraw and re-treat the water for distribution during the spring and summer months of higher demand. The PSD purchases treated drinking water on a wholesale basis from the Beaufort-Jasper Water & Sewer Authority on the mainland. The wholesale water is conveyed to the PSD via a transmission pipeline underneath the Intracoastal Waterway. The pipeline faces relocation due to the pending U.S. 278 Corridor Project.
The PSD has applied for $10 million in American Rescue Plan Act funding from the state of South Carolina to expand the capacity of its RO Treatment Facility and to build a second ASR Facility. The projects will require leveraging of local funding as well.
Recent groundwater studies show that multiple plumes of saltwater are affecting the Upper Floridan Aquifer at Hilton Head Island. Pumping of the groundwater on Hilton Head, on the mainland, and in the Savannah, Ga., region, have combined with natural phenomena to reverse the historic direction of groundwater discharge to the Port Royal Sound and Atlantic Ocean, instead allowing saltwater to enter the freshwater aquifer.