Global coastal populations rely heavily on groundwater, yet this vital resource is increasingly threatened by the encroachment of saline water. The course, Saltwater Intrusion into Freshwater Resources, provides a comprehensive technical overview of the physical processes, causes, and mitigation strategies associated with this geological phenomenon. Led by experts Christopher Rusomello and James Heiss, this content is designed for engineers, hydrologists, and planners seeking to understand the complex dynamics of coastal aquifers and the challenges of sustainable water management.

The curriculum begins by establishing the fundamental science of coastal groundwater, exploring the water cycle, Darcy’s Law, and the physics of flow. Learners will examine mass transport, diffusion, and the crucial role of fluid density in shaping the saltwater-freshwater interface. The course moves beyond theory to investigate the specific drivers of intrusion, distinguishing between natural events—such as storm surges, tides, and sea-level rise—and human-induced factors like groundwater over-pumping and infrastructure development. Through detailed case studies involving Cape Cod, Cape May, and the Floridan Aquifer system, participants will analyze real-world examples of how geological heterogeneity and water usage patterns impact aquifer salinity.

To conclude, the presentation outlines practical engineering and management solutions to prevent or reverse intrusion. Professionals will explore a range of prevention and mitigation techniques, categorized into "hard" engineering solutions and "soft" management approaches. By the end of this course, participants will be equipped with the knowledge to identify risks and evaluate strategies for protecting drinking water supplies.

Key learning outcomes include:

• Understand the basic science of coastal groundwater, including hydraulic head, conductivity, and density-driven flow.
• Identify the primary causes of saltwater intrusion, ranging from reduced groundwater recharge to vertical salinization from storm surges.
• Analyze case studies from New England and Florida to understand how stratigraphy and urbanization affect saltwater wedges.
• Evaluate prevention and mitigation techniques, such as freshwater injection wells, subsurface barriers, and managed pumping strategies.