Delivering a new standard for urban water reuse

City of Santa Monica - SWIP Advanced Water Treatment Facility

To boost drought resilience and reduce reliance on imported water, the City of Santa Monica launched the Sustainable Water Infrastructure Project (SWIP). This project aims to capture stormwater, municipal wastewater, and brackish groundwater for reuse. Faced with a dense city setting, they needed to find somewhere to put their new treatment facility. The City hired our team to develop a solution.

The solution lay underground. By adopting an innovative siting and construction strategy, we determined that the new advanced water treatment facility could be built completely below an existing parking lot on the City’s Civic Center property. This includes an underground stormwater harvesting tank and advanced water treatment facility—featuring membrane bioreactor, reverse osmosis, and ultraviolet advanced oxidation processes—and upgrades to the existing Santa Monica Urban Runoff Recycling Facility.

We supported the City from early planning through construction, serving as owner’s engineer and guiding the project through siting, design, permitting, and funding. We helped identify treatment technologies, evaluated multiple sites, and developed a phased permitting strategy in collaboration with regulatory agencies.

The new facility was approved by the State Water Resource Control Board for indirect potable reuse (IPR) and is the first in California to treat stormwater and wastewater, producing purified water permitted for potable reuse. Our team also supported the City’s successful application for State Revolving Fund financing and provided technical oversite during design-build delivery, procurement, and commissioning.

The improvements to the City’s water storage and treatment system will not only supply a sustainable local source but also improve both groundwater and beach water quality.