Knowledge gaps and education opportunities on direct potable reuse: Interviews with customers of a large, southwestern United States water utility.

Water scarcity is a global public health threat that has increased urgency in implementing new sustainable practices to protect water supplies, such as the use of direct potable reuse, or "advanced water purification (AWP)". The study objective was to use interviews to characterize knowledge gaps and community outreach strategies to increase successful AWP implementation in an arid city in the southwestern United States. Through partnership with a water utility in an urbanized area of Arizona, 6000 individuals were emailed for invitation to participate in interviews. Interviews were conducted over Zoom and transcribed verbatim. Transcripts underwent inductive thematic analysis. Twenty-two individuals participated in interviews, and saturation of themes was reached. Five main themes emerged: 1) Conflation of filters with all treatment and the influence of residential technologies, 2) individual-level control over decisions to use advanced purified water, 3) desire for regulation, testing, and transparency about testing results, 4) concerns about specific chemicals, 5) educational resources to strengthen community engagement. Participants expressed lack of knowledge about how water is delivered to their residences by expressing the desire for opting in or out of system-wide treatment approaches. They also expressed wanting more support in interpreting testing results and having access to multiple outreach modalities. There is a growing body of evidence supporting increased outreach from utilities and governmental entities for water reuse adoption. This work provides insights into why the public may be in support or not of AWP and what information they need to form an opinion.