Mapping Wastewater: Geospatial Insights into Sonoma County’s Septic Systems

How can a large and geographically diverse county develop a full understanding of its wastewater treatment options? This presentation will cover the study and interactive map for the County of Sonoma, highlighting opportunities and challenges relating to wastewater treatment in vast areas of the county that are not currently served by a sewer system. In partnership with Arup, Sonoma County embarked on a comprehensive study to map over 36,000 septic systems using geospatial analysis. The study identified high-density clusters of septic systems and assessed the potential for new or modified wastewater management entities to serve these areas. The project used FME to process and integrate diverse data sets, feeding into the analysis and a public-facing tool in ArcGIS Experience Builder, hosted in ArcGIS Hub. This tool allows users to visualize the distribution of septic systems, identify community clusters, and explore potential solutions such as shared septic systems or connections to adjacent sewer systems. The data-driven approach enables actionable insights for decision-makers and communities. Attendees will learn about the innovative methods used to map and analyze septic systems. The presentation will also cover the implications for climate resilience and water quality, providing a foundation for future community engagement and sustainable wastewater solutions.