Where is saltwater intrusion into depleted aquifers becoming a problem in the United States?

Saltwater intrusion is a significant issue in areas where freshwater aquifers are depleted, often due to over-extraction of groundwater. In Southern California, the extensive use of groundwater for agriculture and urban needs, combined with a declining water table, has created conditions that allow saltwater from the Pacific Ocean to move inland and contaminate the freshwater aquifers. This process poses serious risks to the quality of drinking water and agricultural irrigation supplies in the region.

The geography of Southern California, with its proximity to the ocean coupled with drought conditions, exacerbates the problem. As the groundwater is extracted, the natural pressure that helps keep saltwater at bay declines, allowing saltwater to invade into the aquifers. This phenomenon is particularly acute in coastal areas, making Southern California a prominent example of where saltwater intrusion is a growing concern in the United States.

Other regions, like Texas, North Carolina, and Louisiana, also face water quality challenges, but the specific conditions in Southern California make it a leading area for saltwater intrusion due to its combination of high population density, agricultural demands, and geographic features.