Investigating The Role of Upstream Distribution Network Disruptions in Legionella Colonization of Downstream Water System

Abstract

This study investigates the relationship between upstream water distribution network disruptions, such as leakage and repair work, and the subsequent colonization of Legionella pneumophila (L. Pneumophila) in downstream water systems. Field samples were collected at various maintenance sites, including upstream, downstream, and pit locations, as well as from random high-risk environments such as public laundry rooms and gyms. The presence of L. pneumophila was assessed using the Legiolert test, alongside analyses of physicochemical water quality parameters including temperature, pH, conductivity, turbidity, Total Organic Carbon (TOC), and free chlorine. Soil samples from leakage areas were examined to assess the potential entry of bacteria into the system through surrounding soil. The study compares soil and water sample results to evaluate possible contaminant pathways and examines environmental conditions that support the survival and proliferation of L. pneumophila. Based on these findings, recommendations are proposed for targeted risk assessment, regular maintenance, and effective disinfection strategies to mitigate potential risks in drinking water distribution systems.