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

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.