Centralized or decentralized? Purple pipes or potable reuse? Five weeks ago, this would have sounded like the oddest game of “Would You Rather” I’d ever played. But learning about the conversations Bay Area cities, organizations and engineers are having about the future of our water supply has felt like being introduced to a new world!

This summer I’ve been conducting water sustainability research for Sustainable San Mateo County (SSMC), a nonprofit partnering with local cities and businesses to further environmental, economic and social sustainability. I’m one of four interns working to expand SSMC’s Sustainability Ideas Bank, a database of sustainability programs and policies that have already been implemented successfully by other cities and businesses. Each SIB entry offers a path to action and connects its readers to resources, including contact information for experts and city representatives who can tell them more.

Water is a particularly important aspect of sustainability for San Mateo County, which stretches from Daly City to East Palo Alto and Pescadero. Most of the programs I write about were initiated in response to California’s most recent drought. Today, in the drought’s wake and amid a changing climate, local cities and businesses recognize water conservation and sustainability as imperatives.

For each entry, I situate myself with some background research on the topic. Then, I start looking for experts to interview. Maybe it’s a CEO starting to sign contracts for his cutting-edge onsite water reuse technology, or a public works representative of a city with successful water conservation programs. Besides offering valuable insight on water sustainability solutions, these experts will often introduce me to a web of new contacts to reach out to as I start to pull the entry together. My supervisors are responsive and supportive, offering feedback and new directions to look.

When I began my research, I was surprised at how chaotic our water systems seemed. A water district can be operated by a city or cover parts of multiple. Most projects, like introducing recycled water pipelines, involve communication and agreements with different water and sanitation districts. While this chaos necessitates collaboration across various cities, agencies and customers, it demonstrates that the future of water will also require a patchwork quilt of sustainability solutions.

Most cities will probably consider a combination of centralized and decentralized water reuse depending on the type and locations of properties in their jurisdiction. In some cities, a big, recycled water system with pipelines expanded from a central wastewater treatment plant was established to address water demand issues, and expanding these pipelines is the clear next step in water reuse. In others, it’s too expensive to expand a centralized system to customers who’d use it, so a water agency might consider other solutions like satellite treatment plants. An ordinance requiring on-site water reuse for its major development projects works well in the larger city of San Francisco, but a smaller city may consider other approaches. A more residential city might focus instead on facilitating household gray water and rainwater reuse. Meanwhile, technology for treating water to the point of potable reuse brings the question of whether designated non-potable pipeline infrastructure even makes sense. My research will help SSMC’s clients identify solutions that have worked in similar contexts as their own.

I was interviewing Sebastien Tilmans, the director of Stanford’s Codiga Resource Recovery Center, when he introduced the importance of a “one water” approach. We tend to think about water and wastewater as separate spheres, and this rigid distinction can prevent necessary innovation. Not only are many water users uncomfortable with the idea of recycled water, institutional barriers also prevent collaboration between local water purveyors and wastewater districts. For a sustainable future, we need to get over the idea of “wastewater.” We learn about the water cycle in elementary school: at the end of the day, all of our water is recycled in some way. Water can have different qualities and challenges, but there’s value in every drop. This summer, I learned how much water sustainability relies on this societal change in mindset.

By Calista Triantis

Sept. 8, 2020

Reprinted with permission from the Bill Lane Center for the American West at Stanford University.