This was originally published by The Current GA.
The rapid construction at the Hyundai Metaplant in Bryan County has put a spotlight on the area’s resources, with an emphasis on water. The electric vehicle factory will require millions of gallons of water each day to operate.
In fact, Bulloch and Bryan counties are in the process of obtaining state permits to drill wells to produce more than 6.6 million gallons of water a day for Hyundai to use. The four planned wells will be drilled in Bulloch County. That placement has farmers and other residents in this traditionally agricultural area nervous about the impact on their existing wells.
The factory itself is far from the only new demand on water. Hyundai’s suppliers will need water, too. Housing developments sprouting up to accommodate the area’s growth need water. Municipalities are struggling to figure out how to supply it despite the fact that Coastal Georgia is water-rich compared to many parts of the country.
The coast boasts large rivers like the Savannah and rainfall that averages about an inch a week. Most importantly, it sits atop one of the most productive sources of groundwater in the world, the Floridan aquifer.
The aquifer’s plentiful, pure and cheap water has long been essential to Savannah’s economy. It’s one reason the Union Bag company (now International Paper) was able to set up the largest paper mill in the world in Savannah in the 1930s. The Floridan aquifer still supplies a significant portion of drinking, agricultural and industrial water in the Savannah area. But it’s not limitless.
To protect this shared resource from overpumping, Georgia regulators control how much can be withdrawn. Where the pumping was already causing damage, regulators mandated ongoing reductions in withdrawals.
With these new pressures in mind, it’s time to quench your thirst for water knowledge with a Q&A. The Current GA intends to add to this document as questions arise.
Where does Coastal Georgia get its water? How about the Savannah area?
There are two main sources of water for drinking, agricultural and industrial uses in the region: groundwater from aquifers and surface water from rivers. Most of the coast’s water — about two-thirds — comes from underground, where water sits in rocky or sandy layers called aquifers. The largest of these aquifers, the Floridan aquifer, provides the lion’s share of that groundwater.
The situation in the northern coastal counties of Chatham, Effingham, Bryan and Liberty is different. Here it’s closer to a 50/50 mix of groundwater and surface water for drinking and industrial uses. The surface water is all drawn from the Savannah River or its tributary Abercorn Creek. The area is expected to lean on surface water even more as development ramps up.
Why are we drinking out of Florida’s aquifer anyway?
Most of Coastal Georgia’s groundwater comes from what’s called the Floridan aquifer, one of the world’s most productive. It stretches over 100,000 square miles of Florida, Georgia, South Carolina and Alabama. Florida gets to be the marquee name for two good reasons. The aquifer underlies the entire Sunshine State, all 66,000 square miles of it. More importantly, perhaps, it was the “Father of Florida groundwater hydrogeology, Garald G. Parker, who first described the Floridan in 1955 as part of the state’s effort to understand why Miami wells were salting up during a drought.
I thought it was spelled Floridian?
You thought wrong! As hydrogeologist and aquifer labeler Garard Parker wrote about the adjective “Floridian:” “The simpler and etymologically correct spelling is ‘Floridan.’”
Can I do laps in an aquifer?
Definitely not.
“An aquifer’s not a large pool or underground caverns that you go swimming in,” said Jim Reichard, professor and chair of the department of geology and geography at Georgia Southern University. “There are caverns within aquifers like our aquifer for but for the most part, it’s a layer of rock.”
Above and below the Floridan aquifer are clay-rich caps and floors that don’t let water through easily. Geologists call these confining layers. There’s actually an Upper Floridan and a Lower Floridan aquifer but the confining layer between them is leaky enough that Georgia regulators have begun to designate them both as merely the Floridan aquifer.
How does water enter the aquifer?
Water enters mainly along the fall line from Augusta through Macon to Columbus. It’s here that the layer of rock comes to the surface in Georgia. Rain seeps into the limestone rock. Pulled by gravity, the water travels slowly through pores in the rock toward the coast. It’s not an unlimited resource, however.
Florida hydrogeologist Garald Parker wrote about aquifers’ limits in 1974 when he was the chief hydrologist and senior scientist for the Southwest Florida Water Management District.
“…(O)ur water resources, which seem limitless to most laymen, definitely are finite and cannot continue to be developed haphazardly as has been the practice in the past. Even though they are renewable, they are renewable only within limits. Our problem is in determining what these limits are, how they vary from place to place and from time to time and how to manage the resources so as to prevent depletion, pollution, or salt-water encroachment.”
How long does it take for water to travel through the aquifer?
Most of the water we drink in Coastal Georgia has taken its sweet time getting here.
“I tell my students, the water that we pull out of our faucet here hasn’t seen the light of day in 1,500 years,” said Jim Reichard, professor and chair of the department of geology and geography at Georgia Southern University. “So, guessing that we’re halfway, it’s maybe 3,000 (years) to the coast.”
That travel takes place underground in porous limestone that sits under the surface of coastal counties.
Reichard holds up a sample of limestone to show it off during a Zoom interview with The Current. It’s a palm-sized chunk he collected from above ground, where the layer of porous rock surfaces.
A taste test can suggest the water’s residence time in the aquifer. The farther it travels in the rock, the more minerals it picks up.
“That’s why water here in Statesboro tastes better,” Reichard said. “And it has less sulfur in it because it’s younger, it hasn’t dissolved as much stuff.”
How much water is in the Floridan aquifer in Coastal Georgia?
It’s tempting to think of the aquifer like a big underground reservoir, but it’s more like a slow flowing river, with water seeping in and out all the time. Instead of capacity, geologists talk about an aquifer’s sustainable yield. That’s how much can be pumped out without negative effects like making it harder to pump nearby or decreasing the amount of water seeping into rivers and streams. Or, like we’ve seen in Coastal Georgia, the negative effect of pulling salt water into the aquifer.
A Georgia state water planning document published in 2010 put the maximum sustainable yield for the entire coastal Georgia region plus the state’s south-central region of the Floridan aquifer at 868 million gallons a day. Withdrawals for the two regions totaled 475 mgd by 1999.
But that doesn’t mean all that water can be removed anywhere within the aquifer with no negative effects. Large withdrawals in a small area have already caused problems. See “cone of depression” below.
If I have a well in Georgia, do I own the water it produces?
Technically, no.
Like other Eastern states, Georgia operates under the principle of riparian rights, meaning water is a public resource that belongs to all the people of Georgia. A landowner who drills a well doesn’t own the water but has a right to make reasonable use of it.
Georgia’s Environmental Protection Division regulates water withdrawals and has the power to issue, modify, suspend and revoke withdrawal permits(see, e.g., O.C.G.A. §§ 12-5-31, 12-5-96, 12-5-105, Ga. Comp. Rules and Regs 391-3-2-.05 (groundwater)). Permits from the state are required for withdrawals of more than100,000 gallons per day on a monthly average.
Since the water itself is not owned, permittees can’t sell or market a water withdrawal permit, either.
What’s an artesian well?
An artesian well is one in which the pressure in the aquifer pushes the water to the surface — or even higher in some cases — without a pump. The word artesian comes from the town of Artois in France, the old Roman city of Artesium, where the best known flowing artesian wells were drilled in the Middle Ages, the US Geological Survey reports.
I’ve heard of a “cone of depression” in Savannah. What’s that?
It’s not a clever nickname for a March 18 hangover. It’s an area in Savannah where there are several large water withdrawal permits.
Savannah-area residents and industry have had their big straws in the aquifer here since the 1880s. Before this time, ground water flowed east, discharging into Port Royal Sound and the Atlantic Ocean. But pumping from several large wells has reduced the pressure around them, pulling seawater back toward Savannah.
The cone isn’t an actual dip in the land surface, rather it refers to concentric rings of increasingly lower pressure in the aquifer around the wells. That’s because the Floridan aquifer is what’s called a “confined aquifer” with a clay-rich roof and floor holding the water in place.
There’s also a layer of clay and rock between the Upper Floridan and Lower Floridan. But that layer is leaky enough that water regulators at Georgia’s Environmental Protection Division treat the Floridan as one system.
Credit: Datawrapper
Credit: Datawrapper
What is being done about the cone of depression?
Georgia developed a plan in 2006 to manage groundwater along the coast, in part to avoid a water war with South Carolina. Regulators imposed ongoing restrictions and reductions on permitted water users in targeted areas around the cone of depression, designating three zones:
- The Red Zone includes all of Chatham County and the southern half of Effingham County. (A small portion of Brunswick is also in a red zone because of a different saltwater intrusion issue). This zone is most vulnerable to saltwater intrusion related to the cone of depression. Permitted users reduced their permitted withdrawals by 30% from 2004 to 2010. Withdrawals decreased another 15% in 2020. An almost 10% reduction in groundwater withdrawals in the red zone is scheduled for 2025.
- The Yellow Zone includes Bryan and Liberty counties because they are also vulnerable but less so. Here water withdrawals have been allowed to increase slowly by about 20% over the last two decades. However, a decrease of about 3% is scheduled for next year.
- The Green Zone includes areas not currently at risk of saltwater intrusion so no new no restrictions on Floridan aquifer pumping have been imposed.
The plan appears to be working. The cone of depression measured a pressure equal to 90 feet below sea level in 1998. Now it’s 40 feet higher, EPD Geologist Christine Voudy said at a public meeting about the Hyundai wells in February.
Did harbor deepening affect the aquifer?
The short answer is no, though that was a concern and likely will be again for any new deepening efforts.
Before the recent harbor deepening, which dredged the Savannah river from 42 feet to 47 feet deep, the U.S. Army Corps of Engineers studied the potential effects on groundwater. The main concern was that in some areas of the harbor the roof of the aquifer – the upper confining layer – was already exposed at the bottom of the 42-feet-deep river. Especially worrisome was the possibility that ancient river channels may have cut into the confining layer, making it thinner than expected. The upper confining layer is estimated to vary from 30 feet to 150 feet thick. The Corps’ studies and modeling concluded that deepening to 47 feet deep would not cause a significant increase in the salinity of the aquifer. The Georgia DNR required a monitoring plan to make sure the predictions are correct. The most recent monitoring report, issued in January 2024, concluded, “No chloride concentrations measured during the November 2023 sampling event exceeded benchmark chloride concentrations.”
What about river water?
Good question!
The Savannah River was Savannah’s first source of water and provided residents’ drinking water until the city drilled its first artesian well in Greene Square in 1886, the city’s archives reveal. Within a decade the city had built the waterworks near where the Enmark Arena now stands, and groundwater was the city’s sole source.
But surface water came roaring back as demand for water increased with increasing industrialization, including the arrival in 1935 of Union Bag (the predecessor to International Paper). By 1940, the U.S. Geological Survey warned the aquifer’s level was decreasing.
Savannah opened the Industrial & Domestic Water Treatment Plant in Port Wentworth in 1948. Using water drawn from 10 miles away in the Abercorn Creek in Effingham County, the plant could initially treat 35 million gallons a day. Upgrades over the years have increased its capacity.
The city’s current permit allows for withdraws of up to 55 million gallons a day from Abercorn Creek. The I&D plant can treat up to 58 million gallons a day. Last year it produced an averaged of 47 million gallons per day.
Savannah and its neighbors are looking at surface water to fuel growth. Savannah Water Resources Chief Ron Feldner is comfortable with that plan, because “the Savannah River is such a robust source.” The closing of Georgia Power’s Plant Riverside and Plant Kraft removed almost 400 million gallon a day demand on the river, giving users like Savannah room to request increases in their permits.
Working with a consultant, Savannah is analyzing how to optimize production in the Industrial & Domestic plant’s current footprint and then looking at what it will take to expand it and get more production out of the same plant, Feldner said.
To submit a water question to The Current GA, please email mary.landers@thecurrentga.org.
Credit: The Current GA
Credit: The Current GA
MEET OUR PARTNER
This story comes from our partner The Current GA, an inclusive nonprofit, independent news organization which provides in-depth watchdog journalism for Savannah and Coastal Georgia’s communities. Sign up for their newsletter here.
If you have any feedback or questions about our partnerships, you can contact Senior Manager of Partnerships Nicole Williams via email at nicole.williams@ajc.com.
About the Author
