THE EAST COAST SOLUTION: WATER REUSE + ENHANCED AQUIFER RECHARGE = WATER SECURITY (Invited Presentation)

Groundwater is a critical resource for public water supply in the U.S. Coastal Plain with an estimated 3,800 million gallons per day (MGD) of groundwater consumed for public water supply alone. The most prolific aquifers in the coastal plain are confined, and few systems receive sufficient natural recharge to sustain meaningful groundwater withdrawals. Enhanced (managed) aquifer recharge (EAR) is rapidly emerging as a means to counterbalance declining groundwater levels in eastern coastal regions but has yet to gain wide acceptance due to technical and economic challenges. Risk and operational factors that remain as barriers to sustainable implementation of EAR in deep coastal plain aquifers include, but are not limited to, recharge well injectivity, recharge water-aquifer compatibility, hydrogeological and biogeochemical characterization, predictive computational tools, and groundwater quality, including mobilization of geogenic contaminants.

The presentation will focus on research findings and lessons learned through a 6-year EAR demonstration at the SWIFT Research Center (SRC) in Suffolk, Virginia. The Hampton Roads Sanitation District (HRSD) in Eastern Virginia operates the SRC in advance of implementing a 60-MGD EAR infrastructure project known as Sustainable Water Initiative for Tomorrow (SWIFT) at a cost in excess of $2B. HRSD has developed advanced water treatment systems that treat wastewater effluent to drinking water standards and produce recharge water for replenishing the Potomac Aquifer System. A primary driver of the SWIFT program is reduction of nutrient discharge to the Chesapeake Bay. Additional outcomes include local mitigation of saltwater intrusion and land subsidence.