Adapting wastewater management systems in California for water conservation and climate change

ABSTRACT

In California, wastewater systems have adapted to water conservation and drought for decades. Yet, few studies have investigated how past design assumptions influence potential mitigation and adaptation actions. This paper evaluates adaptation pathways for wastewater management in California and addresses two questions. First, are wastewater facilities experiencing challenges from mismatches in design flow values and current rates of influent flow? Second, what, if any, adaptation actions are underway or planned? To answer these questions, we compiled historical literature and conducted surveys and interviews with wastewater system managers. Approximately half of respondents indicated that they are experiencing challenges associated with changing water use rates. Aging systems have implemented many types of mitigation and adaptation actions, including operational changes, chemical additions, and facility rebuilds. California’s wastewater industry is largely pursuing an incremental adaptation pathway to manage drought and climate change. The paper demonstrates an engaged approach to research on climate change adaptation.

KEYWORDS:

• Integrated urban water management
• water use efficiency
• climate change
• adaptation
• drought
• wastewater treatment

Acknowledgments

This study benefited from the expertise of individuals throughout the state of California, including experts from the wastewater industry and research community. Survey respondents and interview respondents made contributions when free time within the water industry was seemingly in short supply during the global COVID-19 pandemic response of 2020–2021. Many thanks to the California Association of Sanitation Agencies (CASA), Southern California Alliance of Publicly-Owned Treatment Works (SCAP), Bay Area Clean Water Agencies (BACWA), Central Valley Clean Water Association (CVCWA), and the California Water Environmental Association (CWEA) for assistance in distributing and advertising the surveys and outreach. The views expressed in this paper are solely the authors.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplemental data

Supplemental data for this article can be accessed online at https://doi.org/10.1080/23789689.2023.2180251.

Additional information

Funding

This work was funded by the California State Water Resources Control Board (Agreement #19-058-240).

Notes on contributors

Erik Porse

Erik Porse is the Director of the California Institute for Water Resources and an Associate Cooperative Extension Specialist in the University of California Division of Agriculture and Natural Resources.

Caitlyn Leo

Caitlyn Leo is a Research Engineer in the Office of Water Programs at California State University, Sacramento.

Erick Eschker

Erick Eschker is a Professor in the Department of Economics at California State Polytechnic University, Humboldt.

Harold Leverenz

Harold Leverenz conducts research on water treatment and reuse in the Department of Civil and Environmental Engineering at the University of California Davis and the Office of Water Programs at California State University, Sacramento.

Jonathan Kaplan

Jonathan Kaplan is a Professor in the Department of Economics at California State University, Sacramento.

John Johnston

John Johnston is a Professor Emeritus in the Department of Civil Engineering at California State University, Sacramento.

Dakota Keene

Dakota Keene is an Environmental Specialist in the Office of Water Programs at California State University, Sacramento.

David Babchanik

David Babchanik is a student in the Department of Civil Engineering at California State University, Sacramento.