Eastern Municipal Water District, California, USA – Planned groundwater replenishment
Eastern Municipal Water District’s Purified Water Replenishment program will improve the quality and quantity of local groundwater supplies through a planned indirect potable reuse project that is anticipated to break ground in 2026. The project will advance clean recycled water using reverse osmosis and ultra filtration and blend it with tertiary treated recycled water. That blend will be placed into percolation ponds, along with water imported from California’s State Water Project, resulting in a high-quality, low-salinity source of replenishment water. It will remain underground for approximately five years before being extracted and undergoing a final treatment process before entering the water supply distribution system.
The initial phase of the Purified Water Replenishment program will include 651 million gallons (2466 million litres) of advance treated recycled water and up to the same amount of tertiary water, depending on supply availability. That is enough to provide 4,000 homes of water per year within Eastern Municipal Water District’s service area. When combined with replenishment water from the State Water Project, it will provide long-term water quality improvements in the groundwater basin in addition to increasing available groundwater supplies.
Eastern Municipal Water District is California’s sixth-largest retail water agency and was the state’s fastest-growing agency during the most recent census period. It currently relies on a blend of local groundwater, groundwater desalination, and water imported from the State Water Project and the Colorado River Aqueduct. Eastern Municipal Water District is also a national leader in recycled water, which accounts for one-third of its water supply portfolio. With anticipated growth in the region, Eastern Municipal Water District is advancing the Purified Water Replenishment program to ensure it has a succession plan for the continued full utilisation of its recycled water supplies, which are anticipated to increase as the region continues to see development activities.
As of June 2024, Eastern Municipal Water District has received $US30 million in federal funding commitments to support the project, including $US10 million from the Bipartisan Infrastructure Law. Following completion of the facility, tours will be available.