Protecting the Environment through Wastewater Recycling

Over the past ten years, the City of Malibu in northwestern Los Angeles County along the Pacific Coast has implemented an integrated series of projects to improve water quality and protect and restore natural resources in the Civic Center/Malibu Lagoon Area. The latest project in this effort is the new Civic Center Wastewater Treatment Facility (CCWTF), which will replace septic systems in the area that allegedly contribute to non-point source loading of bacteria and nutrients to the adjacent Malibu Creek and Malibu Lagoon, impacting surface water quality and endangered species habitats, and contributing to recreational impairments at Surfrider Beach.

Recycling wastewater for irrigation and aquifer recharge

The 0.5 mgd CCWTF will centralize wastewater collection and treatment and uses membrane bioreactor technology to produce treated effluent that meets the CCR Title 22 recycled water standard. The recycled water will be used for landscape irrigation and other non-potable uses. Recycled water not used for landscape irrigation will be injected into the underlying Malibu Valley Groundwater Basin for dispersal or percolated into the separate Winter Canyon aquifer. 

Recycled water produced at the plant will be distributed within the Civic Center Area via a new distribution system co-located with the wastewater collection system. The three injection wells tie into the recycled water system and will be constructed on the downgradient edge of the groundwater basin in an area identified as an ancient Malibu Creek streambed channel. Wellhead facilities will be screened above-grade, and the injected water will form a partial barrier to potential future seawater intrusion.

“Bottle-tight” collection system enables water reuse

The design of the collection system, which serves an area approximately 2,075 acres in size, uses bottle-tight construction measures such as fused HDPE pipe and manholes with water-tight pipe connection boots to prevent brackish water intrusion. Such intrusion would add to the volume of water treated, increasing costs, and also prevent the planned irrigation reuse. All pipelines are underground in public right-of-ways and easements, and all pump stations will be located below ground, also on public right-of-ways or easements

 

Details

City of Malibu
Malibu, CA

Team

Senior Civil/Environmental Engineer
RMC, now part of Woodard & Curran
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