Thanks to the groundbreaking Pure Water Project Las Virgenes – Triunfo (PWP), a joint venture of the Las Virgenes Municipal Water District (LVMWD) and the Triunfo Water and Sanitation District (TWSD) combining to form the Las Virgenes – Triunfo Joint Powers Authority (JPA), the dream of creating a sustainable local water supply is closer to reality.

As one of a handful of surface water augmentation projects in the state, the PWP will use purified recycled water to create a local water supply while protecting the environment by eliminating nearly all wastewater discharges to Los Angeles County’s Malibu Creek. The JPA — which 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 — is leading this innovative initiative and transforming the way water is managed in Southern California.

Early adopters

Producing up to 6 million gallons per day of high-quality drinking water from local sources, up to 30% of the area’s water supply, the project aims to reduce the JPA’s dependence on imported water, improve local water quality, enhance its resilience to climate change, drought, and other extreme events, and ensure long-term water reliability to its customers. The region will have a reliable, sustainable, and cost-beneficial source of water right where they live that they can repeatedly use.

This water, once it leaves homes or businesses, will be treated seven times before being reintroduced back into the system for use again. Purifying recycled water is not a new concept. The tried-and-true treatment train of micro/ultrafiltration, reverse osmosis, and ultraviolet light/advanced oxidation has been used in many projects like the PWP. The end result is simply an H2O molecule.

“Purifying our recycled water and reusing it diversifies our water supply and creates a sustainable solution to support our current and future water supply needs. The PWP will be a One Water solution for generations to come.”
LVMWD Engineering Program Manager Oliver Slosser

Progressive design-build

In another first for the authority, the JPA has selected the progressive design-build (PDB) delivery model to achieve these goals with Walsh Construction and Brown and Caldwell in partnership with Carollo and Trussell.

“The PWP is a complex and ambitious design-build project that requires a high level of teamwork among project partners, regulators, stakeholders, and the public. We are proud to be part of this dream project,” Brown and Caldwell Regional Practice Leader for Water Reuse Adam Zacheis said.

The JPA’s project comprises the construction of an advanced water purification facility (AWPF), and pipelines to deliver source water to the AWPF, purified recycled water to the reservoir, and brine disposal. The plant will use proven state-of-the-art technology, including membrane filtration, reverse osmosis, and ultraviolet disinfection with advanced oxidation (UV/AOP), to treat the recycled water from the Tapia Water Reclamation Facility (WRF). The purified water will be retreated at the Westlake Filtration Plant before it is delivered to homes and businesses.

To handle seasonal flow variation, the facility’s robust design can accommodate a 10-to-1 turndown. This approach addresses the seasonal imbalance of recycled water demand versus availability of supply from the Tapia WRF to maximize the beneficial reuse of recycled water.

The JPA’s project comprises the construction of an advanced water purification facility, and pipelines to deliver source water to the AWPF, purified recycled water to the reservoir, and brine disposal.

Environmental stewardship

One of the key challenges of the project is compliance with regulatory standards for public health and environmental protection set under the Malibu Creek Time Order deadline. The team’s experts are developing novel methods to achieve pathogen credits, monitor and control chemical and biological contaminants, and meet the California Toxics Rule (CTR) requirements. Taking a tiered approach, the team will maximize reliability and flexibility, while minimizing costs and risks.

“The PWP is a visionary and collaborative effort that showcases the JPA’s leadership and innovation in water management. The project will serve as a model and inspiration for other utilities and regions that are looking for sustainable and resilient solutions to their water challenges,” Walsh Construction Vice President Blayne Goodman said.

PWP construction is expected to start in 2025 with completion anticipated for 2028.

About Las Virgenes-Triunfo Joint Powers Authority

Established in 1964 for Malibu Creek watershed wastewater treatment, the JPA is a partnership between LVMWD and TWSD and serves about 100,000 customers in the Los Angeles area. To learn more about Pure Water Project, go to www.ourpureh2o.com.

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 over 2,100 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.