25-05-2025
Blue pipes on 278 in Hilton Head? Here's what's happening at the site near Crazy Crab
As drivers come on and off the U.S. 278 bridge that connects Hilton Head to the mainland, they might wonder what the yellow-vested men at a construction site near the Crazy Crab are doing with bulldozers, excavators, and stacks of huge blue pipes.
Is the island getting a head start on the expensive waterline relocation needed before the town can finally build that new bridge?
No, the answer is a bit more boring.
The underground holes bored into the island for this particular project are part of an effort to expand Hilton Head's water supply, keeping Hilton Head residents' water bills from skyrocketing as demand for water increases and saltwater intrudes into the island's freshwater supply.
'Boring isn't so boring,' said Hilton Head Public Service District's General Manager, Pete Nardi.
Workers are almost done installing about 1,100 feet of bright blue pipe that will pump brackish water from deep-water well 600 feet underground to a reverse osmosis treatment plant on Jenkins Island.
It's part of a project will add 2 million gallons of water per day to Hilton Head's water supply. The plant's current capacity is 4 million gallons per day, and it's currently connected to three other deep-water wells that help the town meet high demand during the summer months and store excess water during the winter months.
The 12-inch wide pipes arrived onsite about a month ago. To lay them underground, workers use a machine called an auger to bore a long tunnel underground where the pipes will go. A steel casing is installed to support the tunnel and the long blue pipes are pulled through the casing.
The new pipeline will connect to an existing well on Jenkins Island. Workers will finish installing the pipes by early June, but the well project likely won't be completed until next year, Nardi said. Some additional work is needed at the plant, which was built in 2009, to increase its capacity.
As the island's freshwater supply dwindles, more water supply is sorely needed to meet high demand during the summer months while storing excess water in case of natural disasters.
Hilton Head used to pull more freshwater straight from the ground, from layers of limestone 150 feet beneath the surface. In the last 25 years, saltwater from the ocean has slowly seeped into the island's freshwater supply, contaminating 10 of the island's 14 freshwater wells.
That's why Hilton Head needs to instead rely on brackish water from 600 feet underground. The water is slightly salty, but reverse osmosis can convert it into drinkable water. The same process is used to purify bottled water for popular brands like Dasani and Aquafina.
Some of that treated water gets injected back into the ground to be piped back up later, like in the summer months, when demand can peak to over 11 million gallons of water per day. Those layers of limestone deep beneath the surface can act as a bubble that stores 'astronomically' large amounts of water while keeping it fresh.
'It's a huge underground storage that you cannot build above ground,' Nardi said. Over 250 million gallons of water can be stored in the Hilton Head Public Service District's single underground storage well, and the district is building another.
The project will help reduce the island's reliance on expensive water from the mainland.
A thick pipeline buried deep underneath the creek beds alongside the U.S. 278 bridge can supply up to 6 million gallons of water per day to the island, at a cost of over $3.30 per one thousand gallons, Nardi said. Producing water through reverse osmosis will cost between $1 and $1.20 per one thousand gallons.
It's a matter of 'economics,' Nardi said. 'Plus it's really a high quality tap water.'
Between 40 to 60 percent of Hilton Head's drinking water goes towards 'residential irrigation,' according to Nardi.
In other words, roughly half Hilton Head's clean water supply goes towards keeping grass green.
To cut down on water demand, town ordinances limit the number of times residents are only allowed to water their yards to twice a week. Sprinkler systems must be connected to a rain sensor, so that valuable drinking water wasted on a rainy day.
Planting native plants in your yard, rather than grass, can reduce the strain on Hilton Head's water supply — while saving you money on your water bill.
Many golf courses on Hilton Head use recycled wastewater instead of fresh drinking water, reducing the strain on the island's water supply. Hilton Head PSD also pumps recycled water into wetlands to help maintain their size and depth.
The water upgrades alone won't lower Hilton Head residents' water bills. But it does mean that more of the water that flows through the taps in the future will come from the island, rather than being at the mercy of an off-island agency.
'It's going to prevent (your water bill) from so reliant, or potentially being reliant, on more expensive drinking water,' Nardi said.
