One year after the highly anticipated SWIFT project came online in Virginia, its trickle of activity continues to swell.
The Sustainable Water Initiative for Tomorrow is an innovative solution to two problems that plague the Hampton Roads region: the need to cut down on pollution that flows into local waterways and the shrinking of the Potomac aquifer, the main source of water for eastern portions of the state.
In April 2018, instead of simply discharging the treated wastewater back into the rivers, the Hampton Roads Sanitation District began giving it an even greater level of treatment and then injecting it 2,000 feet into the ground to help recharge the aquifer’s increasingly dwindling stores.
A similar approach to aquifer recharge has been adopted elsewhere — particularly in the arid regions of the Middle East and Santa Clara Valley of California — but the proposal to adopt it on a large scale in a “wet weather” area of the East Coast was new.
Now, one year into the experiment, SWIFT is pumping an average of 1 million gallons of drinking-quality water back into the aquifer every day from the SWIFT Research Center, located at the Nansemond Treatment Plant in Suffolk.
That quantity is only a fraction of the 100 million gallons per day that the sanitation district plans to inject back into the aquifer once the project is fully built. But even in these early stages, the U.S. Geological Survey has found that SWIFT is having results.
“[We] saw a signal of expansion of the aquifer by a third of a millimeter over the course of two months,” said Kurt McCoy, a hydrologist at the USGS Virginia Water Science Center, which has been monitoring and analyzing SWIFT since its inception. “It is showing that the SWIFT activities do have an impact on the aquifer.”
A third of a millimeter may not seem like much, but “these things add up over time,” McCoy said.
That’s particularly true in the low-lying area of Hampton Roads, where sinking land and rising waters are closely connected. Recent projections show that sea level in the area has been rising 4–5 mm per year. Historically, about half of that has been caused by the overpumping of water from the Potomac aquifer. Overuse has caused the pressure of the water within the aquifer to decline and the land to sink as the sediments that hold the water are compacted. In the Hampton Roads region, that compaction has occurred at an estimated rate of 1.5–3.7 mm per year.
Within that context, McCoy pointed out, the aquifer’s expansion by a third of a millimeter within only two months’ time is significant.
“It was a bit unexpected for those of us that aren’t geologists,” said sanitation district manager Ted Henifin.
So far, SWIFT has pumped a total of about 90 million gallons of highly treated wastewater back into the aquifer.
Much of the Research Center’s focus has been on refining its processes. Among other tweaks, the site had to be taken offline for a period over the winter because of issues involving the unexpected corrosion of steel tanks.
Eventually, SWIFT will operate out of four or five facilities throughout the district, each of which will return water to the aquifer through multiple recharge wells.
Initial plans called for the first new facility, which would have had a recharge capacity of about 8 million gallons a day, to be constructed at the Williamsburg Treatment Plant near historic Carter’s Grove. In April, though, the James City County Board of Supervisors denied the district’s request to acquire the land on the grounds that the project doesn’t meet state criteria allowing utilities to acquire land in an agricultural and forestal district.
Consequently, while Henifin said that the sanitation district “hope[s] to be able to resolve our land issues in Williamsburg in the coming years,” that expansion has been moved “to the end of our list” of facilities to develop.
“We started out with the toughest one, and we didn’t exactly hit a home run there,” he said.
The next expansions are slated to occur at the James River Treatment Plant in Newport News, followed by the York River Treatment Plant in Seaford, the Virginia Initiative Plant in Norfolk and finally the Nansemond Treatment Plant, where the Research Center is also located.
Henifin said that the district has already acquired or finalized deals to acquire the land needed for those expansions.
Despite the Williamsburg setback, cash-strapped municipalities within the district have greeted SWIFT with open arms because it offers a way to sidestep expensive stormwater repairs that would otherwise be needed immediately to meet pollution reduction goals for the Bay cleanup. Henifin said that all 11 localities in the area with municipal separate storm sewer system (MS4) permits have struck agreements with the district to use credits from the SWIFT project to meet their nutrient reduction obligations.
Such agreements, known as nutrient trading, allow a polluter that achieves reductions beyond the threshold set for it by the state to sell or transfer “credits” for those reductions to other polluters. Those other polluters can then put the credits toward their own reduction quota.
The result is that even if each source of pollution does not achieve its own reduction target, the region can still meet its overall goal.
In its agreement with the sanitation district, the city of Hampton justified its decision to use pollution reduction credits from SWIFT by arguing that the city will “conserve scarce state and local resources for other important water quality projects.”
But while municipalities may be relying on SWIFT for reductions, the state has adopted a wait-and-see approach to including the project as a best management practice in its latest watershed implementation plan for meeting 2025 Bay cleanup goals, released as a draft in April.
“Until it’s proven, we weren’t going to require it in the WIP,” said Allan Brockenbrough of Virginia’s Department of Environmental Quality. Nevertheless, he said, “The WIP counts on significant nutrient reductions from those facilities, and they may achieve those reductions from the SWIFT project.”
Other localities are taking notice of SWIFT’s promise. Henifin said that several representatives of other cities or counties had visited the site to see if they could implement a similar system at home.
“We’re interested to see how effective it is, and we do see it potentially as one part of an integrated strategy both to meet our water supply goals down the road and our nutrient management goals down the road,” said Christopher Phipps, the director of public works for Anne Arundel County, MD.
Anne Arundel does not face a problem with land subsidence, and its water supply is more stable than that of Hampton Roads. But a portion of the county also draws water from the Potomac aquifer, and the county as a whole is subject to the same goal of reducing the flow of pollution to the Bay.
“We’re not under duress, especially on the water supply side, but we do think it could have some potential for longer-term and regional strategies,” Phipps said.
On May 10, the Chesapeake Environmental Protection Association, a nonprofit group, will hold a forum to explore whether the SWIFT model is “feasible and worthy of further consideration” in Anne Arundel and Southern Maryland.
To Phipps, the idea of using treated wastewater to recharge aquifers is part of a broader — and growing — shift among the public toward recycle-and-reuse strategies.
“We call it wastewater, but is it?” he asked. “Should it be wasted, or should it be used?”