SUMMARY Wastewater-based epidemiology (WBE) is an innovative and cost-effective approach that complements traditional, yet important, self-reporting methods and biospecimen testing to construct drug use trends on a community scale. WBE has been successfully applied to estimate consumption of targeted illegal drugs and has more recently been applied to detect the emergence of new psychoactive substances (NPS) in varied settings such as large urban communities and during/after smaller focused events (e.g., festivals, sports events). Yet, this approach has not formally been integrated into the National Drug Early Warning System (NDEWS) Coordinating Center, a platform which provides experts and communities with the most timely information on emerging substance use trends through traditional and novel surveillance data as well as on- the-ground epidemiologic investigations. Therefore this proposal aims to provide accurate up-to-date wastewater chemical/drug surveillance data from designated partner sites of the NDEWS Coordinating Center and wastewater industry, calculate drug consumption over time, and align our approach with existing NDEWS surveillance data to help identify hot spots or new emerging trends across communities on a national scale. This will be accomplished through 2 aims: 1) Coordinate collection and analysis of wastewater samples from NDEWS Sentinel Site locations for known drugs/metabolites and NPS using high-end mass spectrometry approaches and 2) Validate and disseminate actionable WBE data by comparing data from on-going drug use surveillance studies as part of NDEWS with WBE generated drug trends, integrate WBE data with public health and utility information to develop a visualization tool and disseminate information via the NDEWS Coordinating Center and through 2 way regular communication with our water industry and public health partners and their local communities. Our proof-of-concept proposal will provide the benefits of easy integration of WBE into the existing NDEWS framework, and data sets that are immediately available to the NDEWS partners which will, importantly, inform current and emerging drug use trends that can be used to refine public health measures.