7 wells proposed to monitor and halt seawater intrusion
LOS ANGELES COUNTY PUBLIC WORKS
The Alamitos Barrier Project (ABP) was constructed in the mid-1960s to prevent seawater from intruding into the underlying aquifers of the central basin in Los Angeles County and the coastal plain of Orange County.
Over 6 million residents of the Southern California coastal plain depend on this groundwater that provides up to 40 percent of the drinking water supply.
The ABP is one of three seawater barriers operated by Los Angeles County Public Works to protect the drinking water supply from seawater intrusion by continuously injecting freshwater to form a protective pressure barrier.
ABP’s existing infrastructure has been installed from Long Beach to Seal Beach and includes 7.8 miles of water pipeline, 60 injections wells and a network of over 200 observation wells.
Los Angeles County proposes the construction of five injection wells and two monitoring wells to replace and supplement existing ABP facilities located within the cities of Long Beach and Seal Beach.
Five injection wells will replace existing injection wells that are beyond their useful life. Two of the injection wells will be constructed in the City of Long Beach, and the other three injection wells will be constructed in the City of Seal Beach (located within the Los Angeles Department of Water and Power Haynes Generating Station).
The two new monitoring wells at LADWP Haynes Generating Station will be used to monitor the effectiveness of the ABP and improve operational efficiency.
The estimated project cost is $8.4 million with construction currently planned to start in February 2022 and end in October 2022.
Los Angeles County Public Works was awarded a Groundwater Grant (State Proposition 1) in the amount of $4.2 million for the design and construction of this project. No local city funds will be spent on this project.
For more information, visit seawaterbarrier.com or contact project manager Paul Boice at PBOICE@pw.lacounty.gov or (626) 458-6162.