If the Hampton Roads Sanitation District (HRSD) hosted an infrastructure-renovation TV show, they might say something like “Yo dawg we heard you liked water, so we treated your wastewater and put it in the aquifer, so you could have more water with your water.”
And you’d be like, “What?” and they would cut to a montage starting in 2016, with the launch of the Sustainable Water Initiative for Tomorrow’s (SWIFT) pilot project at the York River Treatment Plant, fast-forward to the 2018 ribbon cutting of the SWIFT Research Center in Suffolk, and then to the 2022 groundbreaking for the first full-scale SWIFT Facility at the James River Treatment Plant in Newport News, construction of which is ongoing.
Then you might be like, “Why?” – and that’s because the Potomac Aquifer supplies 75% of groundwater in Eastern Virginia, and is not recharging fast enough to keep up with the roughly 155 million gallons of groundwater* that is withdrawn from it every day, largely by the businesses and residents of Hampton Roads. After that water is used, most of it goes down a drain and into one of 17 Wastewater Treatment Plants (WWTPs) in Hampton Roads, two of which are in Norfolk (and a third just barely across the line in VB). At the WWTP, water goes through primary, secondary, and tertiary treatment in order to meet state and federal standards, and then is discharged into a local water body.
At least, that’s how it used to be done. SWIFT is giving the old model of WWTPs a glow-up. New infrastructure at the WWTPs will deliver treated water directly back into the Potomac Aquifer (groundwater), rather than discharging it into rivers, the Bay, or the ocean (surface water), in a process called Managed Aquifer Recharge (MAR). After going through tertiary treatment, water at the WWTP will be further treated with carbon-based treatment processes to match the chemistry of the existing groundwater before it is injected back underground. And no, this isn’t some Trojan Horse for fracking. SWIFT’s recharge wells are much shallower than fracking wells (2,000 feet vice tens of thousands of feet) and have a much lower recharge rate (10-40 psi vice 700-1500 psi).
Also, the geology of eastern Virginia consists largely of unconsolidated sediments (sand, silt, clay, shells) that are easily permeable; fracking occurs in places with hard, non-porous geology like shale (and, of course, oil and natural gas).
“Okay, but WHY?” Because, the Potomac Aquifer is a confined aquifer, which means it recharges very, very, slowly – so slowly that it would take tens of thousands of years to return to its original levels, even if everyone stopped using it today. Bad Things can happen if aquifers get overdrawn (besides the obvious problem of water scarcity), namely, land subsidence and saltwater intrusion. As the Virginia Pilot recently noted, Norfolk remains in the number one spot for highest sea-level rise risk on the East Coast. This is due in large part to the fact that Norfolk is experiencing land subsidence, which in turn is due to decreased aquifer pressure. So the less water in the aquifer, the more we sink, and the faster the sea will rise. As for saltwater intrusion, the outward, or seaward, flow of freshwater keeps the surrounding saltwater at bay. As the freshwater supply diminishes, so does the outward pressure; saltwater moves in, decreasing storage space for freshwater. If saltwater gets into a pumping well, it can contaminate the water supply, as saltwater is notably unhealthy for consumption by humans and other terrestrial organisms.
SWIFT will recharge the Potomac Aquifer at a rate of 120 million gallons per day, which will help offset current groundwater use, but won’t exceed the aquifer’s carrying capacity. Without this augmentation, we could be facing a water shortage or much higher prices within the next 50 years. This image shows the predicted aquifer pressure 50 years from now, without (left) and with (right) SWIFT replenishment. Suffice to say that red is bad, and blue is good. Remember that low water levels, and therefore, low pressure, in the aquifer will put the region at higher risk for subsidence (and flooding), saltwater intrusion (groundwater contamination, less freshwater available, death of terrestrial plants) and a lower water table (deeper drilling required, higher associated fees). Hydraulic models suggest that this initiative could reduce the local effects of sea level rise by up to 25%.
Another benefit of the SWIFT project is that is will virtually eliminate treated wastewater discharge into the James, York, and Elizabeth rivers, significantly reducing nutrient loads in those water bodies as well as the Chesapeake Bay**. Once the system is fully in place, the WWTP outfalls will only be used in cases of extremely high flows from significant storms. Also, treating wastewater costs money, and will get more costly in coming years as regulatory requirements increase. Instead of discharging this expensive water out into the wild, where it may or may not be recaptured, SWIFT will put it right back into the aquifer so that it can keep being used. And remember, it will be treated beyond current standards to match the chemistry of our existing groundwater, in order to maintain the health and integrity of the aquifer.
HRSD offers both virtual and in-person tours of their SWIFT Research Center.
*Norfolk gets its water from 14 locations, which you can see here.
**Nutrients such as nitrogen and phosphorous are detrimental to water quality and can cause many problems, such as algal blooms, that harm wildlife. Most of these nutrients come from stormwater runoff, but are also found in wastewater.
All images from HRSD or USGS.
Catie Sauer
Ghent, NFK
Catie was born in Norfolk and as an adult has lived here for two years and change. She has a master's in Environmental Planning and Design from the University of Georgia. She likes hiking, playing trivia, being a flaneuse, pinball, memes, and growing vegetables.
