Eastern Virginia has long been withdrawing groundwater from the regional aquifer more quickly than the system can naturally replenish.
But after a brief period of gains, the situation is now reaching a tipping point, according to a new report by the Virginia Department of Environmental Quality.
Without action, groundwater usage in the coastal region could become unsustainable within the next five to 10 years.
Major stressors include growing demand, especially from large industrial users such as data centers, and impacts from climate change, such as saltwater contamination.
Jay Ford, Virginia policy manager for the nonprofit Chesapeake Bay Foundation, said he hopes the report is a wake-up call.
“No one notices groundwater as long as your sink gives you clean drinking water,” he said. “The second it doesn't, and everyone realizes we have a massive problem on our hands, it's too late.”
Some state lawmakers are calling for a special session of the General Assembly to address issues raised by the report.
Here are some major takeaways for Hampton Roads:
Pressure on local aquifers
Much of eastern Virginia relies on the Potomac aquifer system.
It is a pressurized, confined aquifer, meaning the groundwater storage is trapped between layers of sediment and clay materials deposited over time, said Dan Holloway, a hydrogeologist with the Hampton Roads Sanitation District.
The system is bounded to the west by the Interstate 95 corridor, and “kind of radiates out toward the ocean in a wedge shape,” thickening as it moves east, Holloway said.
A large part was shaped by the asteroid that hit what’s now the Chesapeake Bay about 35 million years ago, which disrupted sediments around the impact crater.
The availability of groundwater at a particular site depends on “where you are in the aquifer and what depth you’re trying to get water from,” Holloway said.
The aquifer once had artesian wells with water that flowed freely without the need for pumping.
Over the past century and a half, withdrawals steadily increased, and some heavier use sites have dropped by several feet, Holloway said.
DEQ’s recent study was prompted by a 2024 law passed by the General Assembly. Ford, who helped advocate for it, said there had been plenty of “warning signs.”
The agency set out to comprehensively evaluate the eastern region’s groundwater resources. DEQ officials noted it’s challenging to even estimate total water levels.
“It seems like a simple question that should have a simple answer. If the aquifer system were like a tank, with fixed walls and an overall water level, then the water level could be measured and the total volume calculated,” authors wrote in the report. “Instead, it is complex, composite, discontinuous and hidden underground.”
When conditions change, the aquifer system takes time to respond, and effects vary locally and regionally, the report said.
In the mid-2010s, DEQ ramped up groundwater management, which helped stabilize the overall deficit for several years. But by 2021, the rising trends started stalling and reversing.
The most affected sites surround paper mills in Franklin and West Point, which withdraw large amounts of water. All that pumping has caused lasting “cones of depression,” where groundwater levels decline and sink toward the center.
Water-intensive data centers pose another challenge.
Under current projections, the aquifer system has almost no capacity to support additional big businesses east of I-95.
“That is a complete hold on economic development,” Ford said.
Lawful unpermitted withdrawals, such as private drinking water wells, account for up to 40% of total groundwater withdrawal in eastern Virginia, according to the report. The number of private wells is growing alongside the population.
Climate change is further stressing the system, such as making rainfall more intense.
Steady, light drizzles can permeate the soil and recharge the aquifer in certain areas. But increasingly, “we get these complete deluges,” Ford said.
“When that hits the soil, it sheets off because it is outstripping the soil's ability to let it absorb,” he said. “You need that rain to come at a speed that the soil can allow it to percolate back down into the aquifer.”
Because of its confined nature, the Potomac aquifer is more naturally resilient to drought, Holloway said. But during droughts, people often pump harder because surface water sources, such as rivers and lakes, are dwindling, still impacting the groundwater.
Groundwater withdrawal is also a big contributor to the region’s sinking land. As more water is pumped in the higher layers of the aquifer, water “gets squeezed out” of lower layers to make up for it, compressing the sediments.
Sinking land exacerbates flooding across Hampton Roads, especially as sea levels rise simultaneously.
In the long term, addressing issues with the aquifer will likely need to include cooperation with other states that use the sprawling Potomac system, such as Delaware and Maryland.
Water on the Eastern Shore
The Eastern Shore has its own set of challenges.
The area relies on the Yorktown-Eastover aquifer system as its sole source of drinking water. It’s shallower and smaller than the Potomac aquifer.
On the Shore, the rate of withdrawal is near its historical maximum, according to the DEQ report.
Another recent and related study, led by the U.S. Geological Survey, found that while groundwater levels appear relatively stable, the Yorktown aquifer’s overall storage is expected to continue depleting.
One big threat on the coast is saltwater intrusion. Rising sea levels push saltwater inland, potentially contaminating the freshwater supply.
Chloride concentrations in total have not changed much since the start of the century, the state says, but are notably increasing in some eastern spots, including Chincoteague and West Point.
When pumping pushes groundwater below sea level, it’s easier for seawater to infiltrate.
Elaine Meil, executive director of the Accomack-Northampton Planning District Commission, said in an email that “there is no reasonable, available alternative drinking water source should the aquifer be contaminated.”
Though the DEQ report’s projections of decline focused more on the Potomac system, “admission that the Eastern Virginia groundwater level is on track to decline is horrible news.”
Shore officials have been working with farmers and industry to try and shift their aquifer use to the Columbia system, a shallower aquifer that recharges more quickly.
The Eastern Shore’s regional Groundwater Committee has spent much local time and resources to protect groundwater, and other localities should do the same, Meil said.
“No one wants to wake up to find all residential, commercial and industrial development needs to halt because there is no more water. Or worse, you get a notice you no longer have water for your existing use,” she said.
“Maybe other localities can tap a stream and find another source, but on the Eastern Shore, we don't have a viable second option.”
Recharging the aquifer, one flush at a time
The new state report outlines the limitations of efforts to inject water back into the aquifer as a long-term solution.
Specifically, officials point to the Hampton Roads Sanitation District’s Sustainable Water Initiative for Tomorrow, or SWIFT.
The initiative turns sewage into drinking water, using advanced new treatment infrastructure, and injects it directly into the Potomac aquifer.
HRSD launched the project in 2018 and last year reached a milestone of more than 1 billion gallons pumped underground.
DEQ said these injections may yield a localized increase in water levels. But as soon as they cease, the gains “dissipate rapidly.”
Holloway said the primary motivation behind SWIFT was meeting nutrient pollution regulations. Traditionally, the district releases treated wastewater into the Chesapeake Bay, and has to follow strict standards.
“The thought was, we've got this groundwater depletion problem going on. If we're going to treat it to drinking water standards, can we just put it into the aquifer?”
Building up the water supply and slowing subsidence were always secondary benefits.
But Holloway said HRSD is also confident the project can help. It is already expanding and plans to continue well into the future.
“SWIFT is a long game here,” he said. “The longer we operate and recharge water to the aquifer, the less the impact will be from any temporary episodic shutdowns.”
State officials recommended buying real-time monitoring equipment to better understand the recharge effects of SWIFT, and evaluating other locations that could benefit from similar projects.
How to move forward — including with data centers
Part of the impetus for the state study was figuring out the potential impact of data centers.
“You can’t talk about net resources without recognizing the elephant in the room, and that is data centers,” Ford said.
Most existing data centers use surface water or hook up to municipal systems, Ford said. Their exact interaction with groundwater is unclear.
“It’s kind of a muddy picture about what the current snapshot of data centers and the aquifer is.”
What is clear, he said, is that any data center proposing evaporative cooling should not be eligible for a permit “because our groundwater resources are so stressed.”
One of DEQ’s requests to lawmakers is the power to “say no,” Ford said.
Agency officials don’t currently feel they have sufficient authority to deny groundwater withdrawal permits, even when modeling indicates they’re unsustainable.
Other recommendations include tightening regulations on groundwater permitting and getting a better sense of groundwater usage from private wells.
One concept mentioned in the report is groundwater trading, wherein entities could trade credits for water rights in a market-based system.
Ford said Virginia should be very careful about considering such a system, which has had limited success elsewhere in the U.S.
He also cautioned against robbing Peter’s water to pay Paul: “The answer can't be to then go unsustainably manage our surface water.”
