EXTRACTION BARRIER BRACKISH WATER TREATMENT
Seawater intrusion in the southern Oxnard Plain has long been a problem due to agricultural, industrial, and residential land uses that rely on groundwater. When pumping exceeds recharge, water levels in the groundwater basin can fall below sea level, drawing seawater into the aquifers and impacting water quality.
Unlike coastal Los Angeles and Orange County, Ventura County has no seawater intrusion barrier in place, and the sea impairment renders the groundwater useless for agricultural or municipal uses.
To protect groundwater supplies, United Water is planning a project in collaboration with the United States Navy that will provide a barrier to seawater using extraction wells for hydraulic control and reverse osmosis to treat the brackish groundwater. The project will create as much as 20,000 acre-feet per year of advanced treated “new” water.
The project will reduce groundwater pumping, prevent seawater intrusion into groundwater basins, create an additional irrigation and emergency supply, and is estimated to conserve enough drinking water to supply about 40,000 families for a year.
EXISTING WATER USE IN THE OXNARD PLAIN
PRELIMINARY PLANS HAVE IDENTIFIED
TWO OPTIONS:
EXTRACTION BARRIER CONCEPT: Use coastal extraction wells to create a groundwater depression; water would flow toward wells from all directions and, if the extraction rates are sufficient, seawater should not advance inland past the wells.
The brackish water would be treated and put to beneficial use and the residual brine would be disposed of in the Salinity Management Pipeline (SMP).
INJECTION BARRIER CONCEPT: Surround areas of degraded water quality with a dense array of injection wells and inject enough water to create a groundwater ridge or divide to prevent further intrusion.
TYPICAL REVERSE OSMOSIS TREATMENT TRAIN
TYPICAL REVERSE OSMOSIS TREATMENT TRAIN
LATEST UPDATES
AWA WaterWise Presentation – Update on Coastal Brackish Groundwater Treatment Plan project
February 18, 2021 – PRESENTATION
Click on PRESENTATION above to view the video of the AWA WaterWise presentation from UWCD Chief Engineer Maryam Bral and U.S. Naval Base Ventura County’s Professional Engineer and Water Program Manager Nathan Jacobsen providing updates on the Coastal Brackish Groundwater Treatment project.
