Client: County of Los Angeles, Department of Public Works
Location: Long Beach, CA
Description
The Alamitos Barrier Project (ABP) was designed and constructed in the early 1960s to prevent seawater from intruding into underlying aquifers of the Central Basin of Los Angeles County and the Coastal Plain of Orange County. The ABP is one of three seawater barriers that is operated by Los Angeles County Public Works to prevent seawater from contaminating the groundwater by injecting freshwater to form a protective pressure ridge. Over six million residents in Los Angeles County and Orange County depend on the groundwater from the Central Basin and Coastal Plain as a source of drinking water supply.
The project entailed the construction of five injection wells and two monitoring wells within Long Beach and Seal Beach cities. These wells were established to replace older ones that had surpassed their functional lifespan, with two injection wells situated in Long Beach and three in Seal Beach at the LADWP Haynes Generating Station. Prior to the development of new wells, the outdated ones were sealed to avert potential subsidence or groundwater contamination. The activation of these wells is crucial in continuing the prevention of seawater intrusion into the vital aquifers. Additionally, the two new monitoring wells at the Haynes Generating Station allow for enhanced surveillance of groundwater levels and chloride content, aiding in the