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January 2022

Walsh Construction and Brown and Caldwell to assist City of Santa Monica in achieving water self-sufficiency

Santa Monica, CA - Walsh Construction and design-build partner Brown and Caldwell are set to expand the City of Santa Monica's Arcadia Water Treatment Plant and deliver restorations to the Olympic Well Field. A groundbreaking ceremony kicked-off these water infrastructure projects that are significant components of the City’s Sustainable Water Master Plan and goal of becoming water self-sufficient by 2023.

Walsh Construction and Brown and Caldwell are utilizing a progressive design-build delivery method, and are responsible for the design, permitting, construction, final permitting, and commissioning of facility improvements.

Santa Monica’s water system comprises groundwater basins, treatment facilities, and imported water connections to serve 18,000 customers with an average annual water demand of approximately 11,600 acre-feet per year (AFY). About 50 to 60% of its water supply is from local groundwater resources. The remainder consists of imported water.

The $72 million project is an immediate solution to developing sustainable and drought-resilient water supplies and expanding groundwater production. The City of Santa Monica describes the projects below:

Expansion of the Arcadia Water Treatment Plant will increase capacity from 10 MGD to 13 MGD. Major treatment processes will include modification to the existing greensand filters, new high recovery reverse osmosis, new granular activated carbon systems, and ultraviolet disinfection with AOP. Plant expansions will increase potable water production from 9,900 to 13,400 AFY. New concentrate treatment technology and flow reversal reverse osmosis (RO) installations will boost plant efficiency from 80% to 90% or greater. The flow reversal RO technology will be the first municipal installation of its kind in the United States.

Restoring the Olympic Well Field will include construction of a new Olympic Advanced Water Treatment Facility (AWTF) co-located at the Arcadia WTP. The Olympic AWTF will consist of ultraviolet/advanced oxidation process trains and granular activated carbon filters to remove industrial contaminants and return the basin to its full production capacity while meeting drinking water standards. Further improvements include constructing two groundwater production wells and a pipeline transporting Olympic Well Field groundwater to the Olympic AWTF.

SOURCE: City of Santa Monica, Sunny Wang, Water Resource Manager



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