NEWPORT NEWS, Va. — A scenario playing out in Louisiana is highlighting the importance of protecting the water supply in Hampton Roads.
As of Oct. 5, the U.S. Army Corps of Engineers was preparing to ship tens of millions of gallons of freshwater to New Orleans for people there to use.
Because of the low Mississippi River water level, saltwater from the Gulf of Mexico was expected to get into the river, contaminating the city's water supply.
Scripps News
Saltwater wedge in Mississippi River threatens water in New Orleans
In Hampton Roads, work is underway to refill the Potomac Aquifer—a vital water source for Hampton Roads and beyond— to try to prevent a similar scenario from happening in Hampton Roads.
"The aquifer is a groundwater resource that people (and) industries can tap into to fulfill their water supply needs," said Hampton Roads Sanitation District Water Quality Director Jamie Heisig-Mitchell.
Water from the taps at the SWIFT Research Center in Suffolk is an example of the roughly 1 million gallons of water a day the SWIFT Project is currently putting into the Potomac Aquifer.
“We do a lot of testing here to insure the water quality meets the needs of a potable drinking water source in the Potomac Aquifer System," Heisig-Mitchell said of the research center.
Swift stands for Sustainable Water Initiative for Tomorrow and is a project of the Hampton Roads Sanitation District.
Prior to the project, the sanitation district turned area wastewater into water that is safe for the Chesapeake Bay and then put the water into the bay.
“We started looking into it in 2014, " said HRSD Hydrogeologist Dan Holloway explained. "That’s when we did a feasibility study, just on paper. The idea that ‘Hey, there’s problems in the aquifer. We’re producing this already-really good quality water that was just going to the bay that doesn’t need it. So is there something symbiotic there, where we can take that water, treat it better, put it in the ground.'"
News
Central Park in Cape Charles works on drainage swale to help Chesapeake Bay
As part of the SWIFT Project, wells are being drilled to put the water into the aquifer.
A special treatment facility is being built at the James River Water Treatment Facility in Newport News to treat the water.
As of Oct. 5, two wells, one of more than a half dozen that are being built to support the project, were being drilled near the treatment facility and were expected to be operational in early 2024.
The U.S. Geological Service is also helping out the process by monitoring water quality and levels in the aquifer and how the ground changes as water is added.
“The water quality monitoring will reveal any future effects of the water quality from the injection process," USGS Hydrologist Jason Pope said.
The USGS also works with the Virginia Department of Environmental Quality and other agencies to monitor the aquifer.
"The DEQ and other agencies are concerned with trying to manage this limited resource," Pope said.
By the end of the decade, the facility at the Newport News treatment plant and a similar facility and wells that will be built at the Swift Research Center will collectively put about 50 million gallons of water a day into the aquifer.
The well currently putting the 1 million gallons of water a day into the aquifer will be one of the wells that will support the treatment facility at the research center.
The treatment facility in Newport News will supply about 16 million gallons while the facility at the research center will supply about 33 million gallons.
The water will be delivered to the aquifer by gravity through the wells.
Gravity can be used because the water level in the aquifer is so low the pressure created by the water in the aquifer is weak enough for gravity to force the water into the aquifer.
If the water level rises, and pressure increases and gravity is no longer strong enough, the water can be pumped with more pressure through the wells into the aquifer.
The roughly 50 million gallons a day will help offset the roughly 150 million gallons that are being withdrawn from the aquifer each day in Virginia by the various wells that people have drilled across the state to get water from the aquifer.
“The SWIFT Program is extremely important for Hampton Roads and Eastern Virginia because It provides a sustainable supply of water for our ground water and it also provides an opportunity to offset nutrient discharge to our local waters to support the Chesapeake Bay restoration efforts," Heisig-Mitchell explained. "(It) provides an opportunity to slow or even minimize the rate of land subsidence in the region, and it provides the opportunity to improve water quality by forestalling saltwater intrusion."
Land subsidence is when the land sinks down. When the water level in the aquifer lowers as water is withdrawn for use, that lowers the pressure pushing up on the ground and causes the ground above to sink.
As sea levels rise, reducing subsidence could help combat flooding.
Saltwater intrusion refers to saltwater getting into the aquifer when the freshwater level in the aquifer gets too low and can no longer serve as a barrier to keep the saltwater from the Atlantic Ocean out.
"If you don't do something like SWIFT, I think there are only two outcomes," Holloway said. "One is the saltwater can migrate onto the well field and spoil the well field and then whoever's using it either has to abandon it or has to put in a reverse osmosis treatment, something very expensive. Then, with that treatment you have a brine discharge. That's also problematic. That's all the salt concentrate. You have to get rid of it somehow."
As for the remaining roughly 100 million gallons a day that are currently being withdrawn from the aquifer that SWIFT would not be able to replace, Heisig-Mitchell noted there will be an equilibrium point.
"There is natural recharge that occurs. That occurs in a sliver of area along the fall line within the state of Virginia," she explained. "At some point, there's going to be equilibrium between recharge and withdraw but we don't know exactly what that equilibrium is. So, how much do we really need to recharge here, through the Swift program, in order to balance out the need? That's still an underlying question."
