Conceptual design of the well Aquifer Storage and Recovery system for the Ngã Bảy pilot site

This study explores the feasibility and conceptual design of an Aquifer Storage and Recovery (ASR) or Aquifer Storage Transfer and Recovery (ASTR) system for a pilot project in Nga Bay, Hau Giang Province, Vietnam – within the Mekong Delta (MD). The goal is to ensure freshwater availability during periods of surface water salinity while providing a framework for broader implementation. The pilot aims to demonstrate a functional infiltration and recovery system, address potential operational risks like clogging, and optimize design based on local subsurface and environmental conditions. Initial assessments confirm that the selected aquifer is suitable for infiltration and recovery, with favorable subsurface characteristics and water quality. Analytical and numerical modeling show that infiltration and recovery are technically feasible under current site conditions. ASR is identified as the preferred approach due to its higher efficiency and simpler operation compared to ASTR. Gravity-based infiltration is recommended as the most practical method, avoiding the complexities of pressurized injection. The pilot will provide insights into system performance, including recovery efficiency and operational risks, which will inform the potential for upscaling. Future applications will require further site-specific investigations, particularly in areas with challenging conditions like higher salinity. The study concludes that ASR systems, when appropriately designed and monitored, offer a viable solution for improving freshwater resilience in the MD and similar regions.