Sampling and Monitoring Strategies for Opportunistic Pathogens in Drinking Water Distribution Systems


Opportunistic pathogens (OPs)—notably, Legionella pneumophila, Pseudomonas aeruginosa, and nontuberculous mycobacteria (NTM)—have become a leading cause of waterborne disease in developed countries. Due to their complex ecological habitats and resistance to disinfectants, understanding and characterizing occurrence and dissemination of these OPs in drinking water distribution systems (DWDSs) has been difficult. Currently, there are no robust detection or monitoring tools available to track the presence of OPs and monitoring OPs in a DWDS system is difficult. Where present, OPs may exist at low levels, requiring sensitive methods (large volume sampling) for their capture and identification (molecular detection/viability). As OPs are distributed unevenly throughout distribution systems, the selection of sampling locations becomes a critical component of the monitoring strategy.

Project 4911, Sampling and Monitoring Strategies for Opportunistic Pathogens in Drinking Water Distribution Systems, developed a practical sampling and analytical approach for water utilities to quantify OPs’ presence in DWDSs such that actionable data can be gathered for future risk determination and mitigation. An innovative OPs vulnerability visualizer was also developed, leveraging historical water quality data to provide a practical approach for utilities to prioritize sampling locations for OP monitoring. In this webcast, Zia Bukhari, Senior Scientist at American Water, presented the findings and results of project 4911, which aimed to assist water utilities with sampling and monitoring strategies for OPs in DWDS.


Zia Bukhari, PhD, Principal Scientist, American Water


H. Grace Jang, PhD, Research Program Manager, The Water Research Foundation