Pure Water Project Las Virgenes-Triunfo On Track To Provide Sustainable Water Supply In Los Angeles Area

Brown and Caldwell is partnering to provide engineering design services for the new advanced water purification facility

The Las Virgenes-Triunfo Joint Powers Authority (JPA) is moving forward with constructing an advanced water purification facility (AWPF) – the cornerstone of its Pure Water Project Las Virgenes-Triunfo aimed at creating a sustainable local water supply for communities in the Los Angeles area.

The Las Virgenes–Triunfo JPA Board, a joint venture of the Las Virgenes Municipal Water District (LVMWD) and Triunfo Water and Sanitation District (TWSD), recently approved its first-ever progressive design-build contract to construct the AWFP and most of a main pipeline to deliver source water to the facility and purified recycled water to the Las Virgenes Reservoir.

Brown and Caldwell, a purpose-driven engineering consulting firm creating and delivering water and environmental solutions throughout North America and the Pacific, is serving as the prime consultant for the Pure Water Las Virgenes-Triunfo program, providing comprehensive engineering design services in partnership with Walsh Construction.

“Drawing on our advanced treatment design expertise in water reuse and our extensive alternative delivery experience, we established a highly collaborative working relationship with Walsh and our subconsultants. We’re proud to collaborate on this innovative initiative that will give local residents a reliable, sustainable and cost-effective source of water where they live and can repeatedly use.” - Adam Zacheis, Regional Practice Leader for Water Reuse at Brown and Caldwell

The project seeks to reduce the joint districts’ dependence on imported water, improve local water quality, enhance resilience to climate impacts including drought, and ensure long-term water reliability for customers. The contract approval followed more than a decade of planning, coordination and design. Construction is scheduled to begin April 2026, with operations beginning in early 2030.

Once complete, the project will provide up to 30 percent of the region’s drinking water from a local, drought-resilient source while eliminating nearly all recycled water discharge into Los Angeles County’s Malibu Creek and protecting the watershed. The JPA serves 100,000 customers in the communities of Westlake Village, Agoura Hills, Calabasas, Hidden Hills, Oak Park, and unincorporated areas of Western Los Angeles County and Eastern Ventura County.

“This is a monumental project with implications and benefits beyond the near-term,” said JPA Vice Chair and LVMWD Board President Andy Coradeschi in a recent news release. “This is about future-proofing our entire region to the impacts of climate change and subsequent water supply challenges. By creating a local source of drinking water, we are investing in the resilience and long-term reliability of this region, ensuring that we are not solely dependent on fragile imported supplies. This project secures our future and is a crucial investment.”

Foundational to the project is the AWPF, which is designed to use proven technology, including membrane filtration, reverse osmosis, and ultraviolet disinfection with advanced oxidation to treat the recycled water from the Tapia Water Reclamation Facility (TWRF) to meet or exceed drinking water standards set by the State of California. The purified water will be retreated at the Westlake Filtration Plant before it is delivered to homes and businesses. Learn more about project design here.

“Building on a long history of successful joint projects, we consistently identified and implemented cost effective solutions to design challenges throughout the program,” Zacheis said. “The Pure Water Project Las Virgenes-Triunfo will help transform the way the water is managed in Southern California, as the approach may benefit other water districts and communities seeking sustainable solutions.”

About Las Virgenes-Triunfo Joint Powers Authority
Established in 1964 for Malibu Creek watershed wastewater treatment, the JPA is a partnership between Las Virgenes Municipal Water District (LVMWD) and Triunfo Water and Sanitation District (TWSD) and serves about 100,000 customers in the Los Angeles area. For more information, visit www.ourpureH2o.com.

About Walsh Construction
Incorporated in 1949 in Chicago, Illinois, Walsh Construction is one of the largest and most respected general contracting, construction management and design-build firms in North America. The firm operates out of regional offices across the United States, working with union labor and union subcontractors in the building, transportation and water sectors. For more information, visit www.walshgroup.com/ourcompany.

About Brown and Caldwell
Headquartered in Walnut Creek, California, Brown and Caldwell is a full-service environmental engineering and construction services firm with 50 offices and nearly 2,400 professionals across North America and the Pacific. For more than 75 years, our creative solutions have helped municipalities, private industry, and government agencies successfully overcome their most challenging water and environmental obstacles. As an employee-owned company, Brown and Caldwell is passionate about exceeding our clients’ expectations and making a difference for our employees, our communities, and our environment. For more information, visit www.brownandcaldwell.com.