California’s wastewater sector plays a key role in protecting public health and the environment. It is also the source of recycled water—a growing part of the water supply. But as climate change increases the risks of water scarcity and creates other new challenges, the sector is at a turning point. A recent event brought together PPIC researchers and a panel of experts to explore how wastewater management can adapt to a more volatile future.

Caitrin Chappelle, associate director of the PPIC Water Policy Center, outlined findings from a new report on climate risks to the sector and strategies needed to manage them. She noted that drought—as well as ongoing efforts to conserve water—can have unintended consequences for the sector. Less water flowing into treatment plants affects treatment processes and can harm infrastructure. Less treated water flowing out of these plants reduces supplies for downstream users, ecosystems, and recycled water uses.

Chappelle noted that cooperation is a key strategy for building resilience: “Local wastewater agencies will need to work closely with one another, with water supply agencies, and with the state to build a more resilient future.”

Identifying tradeoffs and understanding the unintended consequences of water conservation and the use of treated wastewater are key to developing good policy, noted the panel’s moderator, Kurt Schwabe, a professor at the University of California, Riverside, and an adjunct fellow at the PPIC Water Policy Center.

The three panelists—Jelena Hartman of the California State Water Board, Adam Link of the California Association of Sanitation Agencies, and Nina Hawk of the Santa Clara Valley Water District—discussed the interactions between water use and wastewater, lessons learned from the latest drought, and ways to improve coordination and information sharing with water suppliers going forward.

Hartman noted that with the 2012‒16 drought emergency behind us, “it’s a good opportunity to talk about what worked, what didn’t work” for managing future low-flow situations. “We need to plan, adapt, and be prepared, because the next drought will come,” she added.

Hawk said her agency is fully behind efficient water use but also recognizes that conservation can have impacts on wastewater management and recycled water supplies. “We really have to step back and take a planning look at it,” she said. Collaboration between water suppliers and treatment agencies is key to managing wastewater for multiple uses, she noted.

Link highlighted the difficulty in planning for future capital improvements for both sanitation and recycled water in a changing climate. “If you’re not sure how low your flows will go, how do you plan for a plant that will be useful 30 years from now?” This may require more creative planning for capital investments to ensure that new infrastructure is flexible enough for changing conditions—for example, connecting recycled water plants to groundwater and surface storage to help them weather drought.

We invite you to watch the video from the event.