Reimagining Water Security in Los Angeles: Inside the Donald C. Tillman Advanced Water Purification Facility

The City of Los Angeles is investing in a more sustainable and secure water future — and Jacobs is bringing that vision to life. As the progressive design-build contractor for the Donald C. Tillman Advanced Water Purification Facility, Jacobs is delivering one of the largest and most advanced potable water reuse projects in the United States.

When complete, the facility will purify up to 30 million gallons of treated wastewater each day from the existing Donald C. Tillman Water Reclamation Plant, with an ultimate capacity of 45 million gallons per day (MGD). Using a robust multi-barrier treatment process — ultrafiltration, reverse osmosis and ultraviolet advanced oxidation — the facility will produce high-quality water for groundwater replenishment at the Hansen Spreading Grounds. 

Groundwater replenishment adds clean, treated water back into underground aquifers — natural storage areas beneath the earth’s surface. These aquifers supply drinking water to homes and businesses, especially during dry periods. By treating wastewater to a high standard and allowing it to soak into the ground through special spreading grounds, cities like Los Angeles can refill these underground reserves. It’s a safe, sustainable way to reuse water and deliver long-term water security. 

Collaborating for impact

From day one, Jacobs has worked closely with LA Sanitation and Environment (LASAN) and the Los Angeles Department of Water and Power (LADWP) to define project goals, explore innovative design strategies and establish a strong foundation for delivery. We conducted extensive flow studies to increase capacity and piloted treatment elements such as reverse osmosis to effectively remove low molecular weight organic compounds and safeguard public health. We held numerous workshops with city staff throughout the first nine months of the project to advance the concept design, garner stakeholder consensus and accelerate the final design and overall delivery schedule. 

Increasing groundwater recharge is key to maximizing the city’s investment. Through operational adjustments and waste flow reductions at the water reclamation plant, Jacobs and city staff increased the AWPF capacity from 19 MGD to 30 MGD, and during construction we made provisions for an easy expansion to 45 MGD. 

Jacobs’ scope across the Donald C. Tillman site includes:

• Leading the full lifecycle delivery of the Advanced Water Purification Facility — from permitting and design through construction, startup and commissioning.
• Constructing advanced equalization basins capable of storing up to 9.2 million gallons of water to manage flow variability and support climate resilience.
• Upgrading electrical systems across the site to improve energy efficiency and support sustainable power use.
• Designing and delivering a visitor and learning center to educate the public and encourage community engagement around water reuse.

An innovative promise to the future

The Donald C. Tillman Advanced Water Purification Facility is more than a feat of engineering — it’s also a space for learning, connection and public trust. At its heart is a state-of-the-art visitor center designed to bring the science of water reuse to life. Through operating systems and immersive displays, visitors will see firsthand how advanced treatment technologies protect public health and support a sustainable future. 

Innovation and resiliency extend beyond treatment processes. From digital modeling to design strategy, Jacobs embedded forward-thinking solutions into every layer of the project. Early adoption of Building Information Modeling (BIM) enabled immersive 3D visualizations that helped stakeholders understand complex systems and make faster, more informed decisions. Accurate cost estimating — with less than 5% variance from concept to guaranteed maximum price — gave the city confidence in its investment, while early procurement of long-lead equipment helped compress the schedule. 

Smart design choices, like basement-level piping corridors, saved space and improved operational access, reinforcing the project’s sustainability and adaptability.

Construction began in December 2024, with startup scheduled for 2027 and final completion expected in 2028. The project is already demonstrating the benefits of progressive design-build — rapid design development, seamless collaboration across trades and a shared commitment to delivering sustainable infrastructure that meets today’s needs and tomorrow’s challenges.