SEPTEMBER 2017 PRESIDENT’S COLUMN
GROUNDWATER REPRESENTS ABOUT 97.5% of Earth’s liquid freshwater. Much groundwater occurs in aquifers, which develop from Earth’s water cycle, as a function of the rain that ultimately percolates through the soil and accumulates underground.
Groundwater availability is paramount for water supply. Unfortunately, not all aquifer systems are easily accessible or equally distributed around the world. This inequity in availability results in water scarcity, which is exacerbated by competing demands and groundwater overuse from population and development growth. In addition, climate variability further impacts water scarcity by reducing water resource availability. As a result, strategies should be developed to effectively manage aquifer systems in order to increase groundwater availability for water supply and to sustain life.
Aquifer recharge is a proven approach for managing aquifer systems that are impacted by overdrafting or water quality deterioration from contamination or salt water intrusion. Aquifer recharge may be accomplished through the use of wells (e.g. recharge wells and aquifer storage and recovery) or percolation basins, strategically located to promote infiltration and maximize recharge benefits. Aquifer recharge strategies may be implemented for the following purposes:
- Abatement of saltwater intrusion to avoid contamination of fresh groundwater with saltwater
- Increased groundwater availability and supply
- Localized water quality improvements for impaired groundwater systems
- Elimination of outfalls that discharge nutrient-laden effluent into surface waters (e.g. ocean outfalls) to protect water quality and aquatic habitats
- Limit land subsidence resulting from the overdrafting of aquifer systems
- Minimize the impacts of sea-level rise related to land subsidence (increased flooding) and saltwater intrusion (increased expansion of the salt water front)
Effective management of aquifer recharge revolves around fully understanding the characteristics of the aquifer system (e.g. water quality and hydrogeologic parameters) that will serve as the control volume for recharge. Such understanding allows for the development of recharge schemes tailored to meet or exceed these control volume characteristics.
To manage the impacts of water scarcity on aquifer systems, aquifer recharge must consider the use of water supply sources that are climate independent and not limited by geographic location, such as reclaimed water. A plethora of advanced water treatment technologies are currently available to effectively treat the effluent of wastewater treatment facilities for reuse in groundwater recharge or other intended reuse purposes, allowing for the transformation of what normally would be considered a waste into a resource. Such strategy promotes the diversification of water supply sources and enhances the resilience of water supply systems.
Notable examples of managed aquifer recharge schemes include Orange County Water District’s Groundwater Replenishment System in Orange County, California; Western Australia Water Corporation’s Groundwater Replenishment Scheme in Perth, Australia, and the upcoming Sustainable Water Initiative for Tomorrow (SWIFT) by Hampton Roads Sanitation District (HRSD) in Virginia Beach, Virginia. These aquifer recharge programs comprise solutions to saltwater intrusion, groundwater availability, contamination of surface water from nutrient-laden ocean outfalls, land subsidence and sea-level rise. There are many other programs that have also been implemented in the states of Texas, Arizona and Florida, to name a few.
As we consider the impacts of water scarcity on our water resources, we can appreciate the importance of effectively managing aquifer systems. How do we stay ahead of these issues and other pressing water challenges? We must continue to engage with the water resources community to exchange ideas and progressive solutions. The American Water Resources Association (AWRA) will provide such an opportunity during the upcoming 2017 International Conference on “Cutting-Edge Solutions to Wicked Water Problems,” which will take place in Tel Aviv, Israel, September 10 – 11. AWRA, in collaboration with the Water Research Center of Tel Aviv University, will foster a dialogue on how water managers, engineers, scientists and policy makers are working together to develop and implement solutions to the most-pressing water challenges.
Israel’s location in a semi-arid region has allowed the country to become a leader in the development and application of innovative water technologies. Tel Aviv provides an ideal location for exchanging information, knowledge and data among the water resources community. The meeting has been strategically developed to coincide with WATEC 2017, Israel’s biennial Water Technology and Environmental Control Exhibition & Conference, which will also be held in Tel Aviv immediately after our conference.
Please come and join us in Tel Aviv for continued collaboration and dialogue in support of water resources and AWRA’s goal to provide Community, Conversations and Connections. See you in Tel Aviv!
Rafael E. Frias, III can be reached at President@awra.org.