A National Inventory of Onsite Wastewater Treatment System ( <scp>OWTS</scp> ) Data

ABSTRACT Access to safe and sustainable wastewater treatment is a challenge for many people in the United States. Data describing the location and status of wastewater infrastructure are critical for addressing infrastructure gaps. Onsite wastewater treatment systems (OWTSs) are an important component of wastewater infrastructure; however, there is a dearth of available OWTS data across the United States, making it difficult to locate, evaluate, maintain, and improve wastewater systems. Where data are available, it can be an arduous task to acquire and transform them into usable formats. Thus, the purpose of this study was to create an interactive inventory of OWTS data to increase data accessibility and inform the development of a national OWTS data repository. Here, we identified (1) where OWTS data are available and (2) the attributes of available data (e.g., data format). We conducted an iterative internet search for OWTS data at state and local scales (by county, or town in Connecticut) in all 50 states. We discovered that OWTS data were available at parcel resolution for 41% of the United States and 30% of the contiguous United States (by area). The resulting inventory can be accessed at https://aub.ie/owtsdatainventory and will increase accessibility to currently available data for the OWTS community, from OWTS professionals to regulators to scientific researchers. Additionally, this work provides commentary on potential data challenges and the next steps necessary in building a complete national OWTS database.