Pathogen Monitoring in Wastewater for DPR Regulation Development

Presentation Description: The California State Water Board (SWB) sponsored an Expert Panel administered by the National Water Research Institute (NWRI) which identified knowledge gaps for developing regulatory criteria for direct potable reuse (DPR). Six research projects have been identified to address these gaps. The focus of the second of these research projects, DPR-2, was to assess the concentration of relevant pathogens in raw wastewater (RWW) via a multi-laboratory, 12- month monitoring campaign. The selected organisms were Giardia, Cryptosporidium, enteroviruses, adenovirus, noroviruses, SARS-CoV-2, and male-specific coliphage. Methods included culture, direct observation and quantitative molecular techniques. Five major metropolitan wastewater utilities participated in the study. Raw wastewater can be a challenging matrix and, therefore, method modifications for each organism type were explored and optimized. It was critical that a robust quality assurance project plan (QAPP) was in place to ensure comparable data from the laboratories working with a complex matrix. It was found that critical elements contributing to differences between the labs included the source of molecular reagents and standards, surrogates and matrix spike materials, and equipment used. A summary and overview of current methods for these pathogens will be presented.