Keeping the saltwater out of Hilton Head’s drinking water takes on new challenges
Keeping the fresh water clean and salt free is a science and a bit of artistry and Hilton Head’s experts have had many years of perfecting this process. But the challenges of keeping the saltwater out of the drinking water continues to get more complicated.
Hilton Head residents rely on a steady stream of fresh, clean water coming from their taps each day. To ensure this process continues, the Hilton Head’s largest Public Service District has started construction on a new well and an expansion of an existing treatment plant. The projects will help secure sources of fresh water as salt continues to creep into the island’s traditional water source, rendering it undrinkable.
The island’s first source of drinking water is an underground aquifer known as the Upper Floridan Aquifer, which sits about 150 feet below the surface. Since 2000, 10 of the island’s 14 wells that pull water from this source have been lost to a process known as saltwater intrusion, Pete Nardi, the PSD general manager, said. The deeper, new well is being dug alongside an expansion of a water treatment plant that removes the salt from drinking water before it makes its way to resident’s taps.
“The PSD still faces a risk of about two and a half million gallons a day of drinking water supply due to salt water intrusion,” Nardi said.
Workers began construction the new, 600-foot well into a deeper aquifer, known as the Middle Floridan Aquifer, on Feb. 14. It sits on the site of the Old Welcome Center on William Hilton Parkway. The project is part of a larger effort to diversify Hilton Head’s drinking water options.
Alongside the new well, the Hilton Head Public Service District is also undertaking an expansion of the reverse osmosis treatment plant. The plant is able to treat the brackish, or slightly salty, groundwater so it’s fresh and safe to drink. The plant on Jenkins Island can currently filter 4 million gallons a day. This project will increase its capacity to 6 million gallons. Reverse osmosis filters out a number of contaminants and is a common method used to treat many types of bottled water, including the Aquifina brand and Nestle.
“It’s really a leading tap water treatment technology,” Nardi said.
Some of the original wells that are dug into the aquifer closer to the surface are still operational. Those provide the island with about two and a half million gallons of water a day, Nardi said. That supply is likely to be lost to saltwater intrusion in the coming years.
The Hilton Head PSD also buys water from the Beaufort-Jasper Water and Sewer Authority. That water is pulled from the Savannah River, and the Hilton Head PSD stores it in underground aquifers over the winter months. Then as more people arrive on the island during the summer months as demand for water increases. It pulls out that stored water, retreats it and sends it to taps across the island.
Buying water from the mainland is expensive, so it’s much more economical to invest in using the island’s own groundwater supply, Nardi said.
Updates to this article were made to reflect the correct name of the Floridan aquifer and the construction timeline. Drilling of the well has not started as of press time, but other construction has begun.
This story was originally published February 21, 2025 at 1:04 PM.
