ACCOMACK COUNTY, Va. - A new state report is raising concerns about the long-term availability and quality of groundwater on Virginia’s Eastern Shore, with environmentalists pointing to the results to argue for more restrictions on data centers.
The Virginia Department of Environmental Quality recently studied groundwater supplies east of Interstate 95 at the direction of the General Assembly. The report concludes that the broader Virginia Coastal Plain has limited capacity to support significant new groundwater withdrawals.
On the Eastern Shore, nearly all groundwater comes from the Yorktown-Eastover aquifer system, according to the DEQ. Reported use during the 2023-2024 modeling period was about 6.21 million gallons per day, close to the previous year’s historic high of 6.46 million gallons per day.
When estimated private residential wells and other uses are included, total groundwater withdrawals in the Eastern Shore Groundwater Management Area averaged approximately 9.3 million gallons per day.
Industrial operations and private domestic wells were the two largest uses, accounting for a combined 67% of the total. Agriculture and irrigation accounted for another 18%, a much larger share than in mainland Eastern Virginia.
DEQ cautions that agricultural use may be underreported because some irrigation withdrawals do not meet the state’s mandatory reporting threshold.
Concerns in Accomack County
The report identifies several areas of concern in Accomack County.
State modeling found that some portions of the Middle and Lower Yorktown-Eastover aquifers near Chincoteague could eventually experience chloride concentrations above 250 milligrams per liter, the federal secondary drinking-water standard.
Chloride is commonly used as an indicator of saltwater intrusion. Elevated concentrations can give drinking water a salty taste and contribute to corrosion, although the secondary federal standard is based primarily on aesthetic effects rather than direct health risks. The report says groundwater levels have fallen below sea level in some locations, creating conditions that could draw saltwater inland from the coast or upward from deeper underground.
DEQ found evidence of localized increases in chloride along parts of the Eastern Shore, particularly near Chincoteague. However, the agency did not find widespread, region-wide saltwater contamination.
The report also notes that groundwater sampling on the Shore remains limited. Nearly half of the wells included in an earlier analysis had been sampled only once, making it difficult to determine whether local chloride increases are temporary or part of a broader long-term change.
Major new withdrawals could face limits
To determine how much additional demand the aquifers could support, DEQ modeled a hypothetical withdrawal of 3 million gallons per day in Accomack County.
The model found that the withdrawal could affect aquifers as far as 8.2 miles from the well, cause excessive declines in groundwater levels, and increase chloride concentrations. It also showed the potential for pumping to pull saltier water upward into the Upper Yorktown-Eastover aquifer.
The finding could present challenges for future water-intensive development, including large industrial facilities, processing operations, or data centers. Such projects may need to rely on public water systems, reclaimed water, or other alternatives instead of large new groundwater withdrawals.
Aquifers losing stored water
Although groundwater levels on the Eastern Shore have appeared relatively stable or declined only slightly in recent years, the report says the confined aquifers are continuing to lose stored water.
That loss currently accounts for slightly less than 7% of withdrawals from the confined Yorktown-Eastover system. DEQ expects depletion to continue at or near its present rate because pumping is close to the highest level recorded on the Shore. The state also projects potential chloride increases near Cape Charles and Occohannock Neck in Northampton County.
Potential Effects on Growth
Private residential wells generally do not require state withdrawal permits, according to the DEQ, meaning new homes and subdivisions can collectively increase groundwater demand without undergoing the same review required for a single large industrial user.
DEQ recommends requiring local governments within groundwater management areas to consider water availability when preparing comprehensive plans. Under that proposal, planned growth could be limited in areas where groundwater is insufficient and no other water source is available.
The agency is also asking state lawmakers to give it clearer authority to deny or reduce withdrawal permits when surface water, reclaimed water, or another reasonable alternative is available. Other recommendations include improving the state’s inventory of private wells, expanding groundwater monitoring, hiring additional permitting and enforcement staff, and increasing groundwater permit fees.
CBF responds
On Monday, July 27, the Chesapeake Bay Foundation reacted to the newly-released study, highlighting the findings in an argument for cracking down on data centers in the Commonwealth.
“This is a system on the edge," Chesapeake Bay Foundation Virginia Policy Manager Jay Ford said. “Without changes, Virginians could see escalating problems like accelerating saltwater intrusion, damaging the water supply and the broader Chesapeake Bay watershed ecosystem.”
“We cannot allow energy-guzzling data centers to continue depleting our drinking water supply and wreaking havoc on Virginia and the Bay," Ford continued. "We urge the administration and the General Assembly to modernize the Commonwealth’s water resource laws and call on regulators to impose more stringent requirements on data centers’ water use.”
You can read the full report here.
