From The Editor | October 10, 2017

San Francisco Wants To Lead The Future In Water And Wastewater Resources

Peter Chawaga - editor

By Peter Chawaga, Associate Editor, Water Online

San Francisco

Few organizations are in a better position to affect our approach to climate change than water and wastewater utilities.

These groups have direct influence over how we manage some of our most critical natural resources and have a vested interest in protecting those resources and using them in a sustainable way. Many utilities have already taken leadership roles in stemming or reversing the negative impacts that pollution has had on our climate, from increasing wastewater recovery practices to using potable water more efficiently.

But perhaps the most influential leader to emerge has been the San Francisco Public Utilities Commission (SFPUC), which has developed a model it calls “OneWaterSF” to better manage and protect the critical resources under its charge.

“With OneWaterSF, we can maximize the efficient use of our resources and recognize the potential of all the resources within our system,” said Paula Kehoe, SFPUC’s director of water services. “OneWaterSF allows us to look more holistically at our system for efficiencies, project synergies, opportunities to harness clean energy, and to match the right water to the right use.”

The approach is meant to help SFPUC, which delivers water to 2.7 million customers in a notoriously drought-ridden part of the country, manage water collectively in all of its stages: drinking water, wastewater, stormwater, and graywater.

“For example, our local water program looks to supplement water from our regional water system — which brings water from 167 miles away from San Francisco — with recycled water and local groundwater in order to make our supplies more resilient in the case of an earthquake or other disruption to our water infrastructure,” said Kehoe. “And, a holistic approach to stormwater management coupled with the latest water treatment technology, allows us to utilize this source of water as an alternative supply for such uses as irrigation or toilet flushing.”

Like many initiatives around the country, OneWaterSF has a focus on resource recovery, extracting the usable fuel from wastewater as part of the treatment process.

“Resource recovery projects have the potential to harness high-energy resources from the wastewater stream so that we can utilize these resources to supplement energy requirements, including those that may be needed for advanced water purification processes,” Kehoe said. “We can look at wastewater as a resource for non-potable and even potable water supply and what the impacts of keeping more water out of the sewer system will be. In the end, we believe that this approach will better position us to optimize the use of our finite resources and create a more reliable and resilient future for San Francisco.”

The initiative will also encompass infrastructure projects. A focus is being put on green infrastructure to manage drainage. And SFPUC is planning to co-locate solar installations on water and wastewater facilities and utilize wastewater byproducts to fuel operations.

Kehoe sees SFPUC’s non-potable program as the most groundbreaking aspect of OneWaterSF. The goal is to use alternative water sources, not the oft-strained purified water supply, for things like irrigation and toilet flushing. The utility has a treated wetland system at its headquarters building and is working toward getting other large commercial buildings in San Francisco to do likewise. In the future, it hopes to advance this part of the program even further.

“The next big challenge is looking beyond the more traditional recycled water projects that focus on irrigation, and moving to innovations in onsite reuse and purified water,” Kehoe said. “Purified water is an emerging area that will see a lot of progress over the next decade both in technology development and on the regulatory front. To support this, SFPUC is participating with other utilities on research efforts. We are also conducting a research project to examine the feasibility of developing purified water at the building scale.”

Despite all this change, SFPUC doesn’t expect the OneWaterSF plan to necessarily strain its budget or cost its ratepayers any more. Rather than building lofty new facilities or investing in cutting-edge technologies, it’s more of a framework designed to advance projects that are already identified in the budget and are thought to provide benefits across more than one resource area.

“The OneWaterSF lens helps us prioritize and better articulate the importance of some projects,” said Kehoe. “While there isn’t a big price tag on OneWaterSF, it does provide the benefit of enabling a cultural shift in how we value and manage our resources in the long run.”

But in addition to providing a more resilient water supply, better utilizing local wastewater resources, and creating more sustainable infrastructure for the city, OneWaterSF hopes to influence national, even international, utility practices.

“Some advice that we’d provide other communities interested in establishing a ‘One Water’ program is to look across traditional boundaries and find individuals who are passionate about collaboration and creative ideas,” Kehoe said. “Also, recognize that ideas can come from anywhere within your organization. Finally, remember that One Water is really about an approach to resource management that requires a change in thinking — one that embraces collaboration, innovation, and technology.”

Image credit: "San Francisco," Alexander Russy, 2015, used under an Attribution 2.0 Generic license: https://creativecommons.org/licenses/by/2.0/