After 25 years of operation, the campus Wastewater Treatment Plant is due for significant updates to keep serving our growing university and contributing to a flourishing riparian habitat. As part of the university’s commitment to maintaining and upgrading its infrastructure for efficiency and sustainability, the Utilities Wastewater Treatment Plant team is pursuing a study to identify improvements to increase the longevity and efficacy of the plant. 

From electricity powering lab equipment to water irrigating campus landscapes, UC Davis owns and operates its own utilities, with crucial staff and infrastructure keeping the university running like its own little city. A major piece of this system is the wastewater treatment plant, which treats approximately 1.2 million gallons of wastewater produced on campus each day. This water is treated to recycled water standards and is discharged into the Arboretum Waterway and Putah Creek, where it supports thriving ecosystems. 

The planning project, which began in January 2025, will include recommendations for major improvements, models of projected growth and more information to inform future updates to the plant. 

“This study will help the Utilities team figure out where best to focus improvements to continue to reliably treat wastewater from the campus,” said Courtney Doss, senior civil engineer for the Engineering and Compliance Team. 

The Wastewater Treatment Plant came online in 1999 and in its nearly three decades of operation, equipment has aged and UC Davis has grown significantly. This growth is reflected in not only the volume of wastewater but also in the variety of discharges into the water, especially as research diversifies and expands across campus. 

“The most important aspects of this project are the change in the wastewater composition and how the treatment process has changed over the past 25 years,” said Brad Butterfield, wastewater treatment superintendent. "We need to find a better way of treating the wastewater to be able to meet our goals and requirements from the California Regional Water Quality Control Board.” 

Maintaining the treatment plant is crucial to sustaining normal campus operation, including research, teaching and housing, which rely on the plant to treat discharge. Additionally, as the Arboretum Waterway undergoes an exciting habitat enhancement project, the Wastewater Treatment Plant plays a crucial role in providing a reliable source of high-quality recycled water 

“It’s important that the Wastewater Treatment Plant effectively removes all pollutants and pathogens from the wastewater so we don’t degrade the local waterways,” Doss said. 

Operators at the Wastewater Treatment Plant have already implemented some changes based on project findings, including increasing aeration during the treatment process to more effectively remove certain pollutants. The study is expected to conclude with full recommendations in Fall 2025. Utilities staff members are collaborating with Design and Construction Management to develop and prioritize the recommended improvement projects. 

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