Change Location Change Location

You appear to be near: Central/Midwest

Please confirm or change to view projects in your region.


  • Central/Midwest
  • Northeast
  • South
  • West
  • Canada
  • International

October 2017

Terminal Island Water Reclamation Plant: Advanced Water Treatment Technology for the Future

LOS ANGELES - The ultimate expansion of the Advanced Water Purification Facility at Terminal Island Water Reclamation Plant incorporates the latest wastewater treatment technologies that take wastewater through a disinfection journey to find a renewed purpose.

The design-build team, led by Walsh Construction, completed the expansion that increases total wastewater treatment capacity to produce 12 MGD of high-quality water for groundwater replenishment and reuse.

This innovative facility takes wastewater that would have been discharged into a nearby harbor and cleans the water using advanced water purification technology including microfiltration, reverse osmosis, and an advanced oxidation process (AOP). The AOP uses ultraviolet light and sodium hypochlorite (industrial-strength bleach) to provide disinfection for the entire facility. One advantage of the AOP is the disinfection of almost all contaminants without creating more pollution.

The cleaned water will be used nearby at the Dominguez Gap Barrier to protect groundwater reservoirs from seawater intrusion, at the Harbor Golf Course for irrigation, by recycled water customers for cooling water or other industrial applications, and will potentially replenish Machado Lake.

Increased water shortages are projected within the next 10 years in tandem with increased population growth and environmental footprints. These advanced water treatment technologies will assist in providing more high-quality water supply while decreasing the potable water demand from the Los Angeles Department of Water and Power. This ultimate expansion project will lead to reusing all effluent and ceasing discharges to the nearby harbor to comply with future NPDES requirements.

In the March 2017 Los Angeles Bureau of Engineering newsletter, Mayor Garcetti stated, “...saving water is as important as ever. This new facility is a bold investment that will help us save drinking water, expand our use of recycled water, and become a more sustainable city for generations to come.”

The Walsh team designed the expansion to integrate seamlessly with the existing advanced water treatment systems and into the existing plant footprint while minimizing any impacts to existing operations during tie-ins and shut-downs. Walsh is completing this complex and innovative expansion under the original budget.



929 West Adams Street
Chicago, Illinois 60607
T: 312.563.5400
F: 312.563.5466



2839 Paces Ferry Road SE
Suite 1200
Atlanta, Georgia 30339
T: 404.495.8700
F: 404.495.8701



36 York Mills Road
Suite 302
Toronto, Ontario M2P 2E9
T: 416.849.9000
F: 416.849.9100

©2021 The Walsh Group. An Equal Opportunity Employer, Disability/Veteran. All Rights Reserved.   Walsh Canada Accessibility