AWWA WQTC58974

This study is part of the research program on Legionella contamination of hot water distribution systems and cooling water systems, conducted by Veolia Water. This paper focuses on the multiple interactions between pipe materials, bacterial colonization, and disinfection procedures. A model hot water distribution system, composed of mild steel, galvanized steel, and PVC-c pipe sections, was supplied with drinking water slightly contaminated by Legionella. Biofilm and water phase colonization did not depend on pipe material. However, efficiency of disinfection procedures might be affected by pipe material. Furthermore, the incompatibility between several materials and disinfection treatments was demonstrated. In particular, shock treatment with hydrogen peroxide and peracetic acid dramatically and durably affected the corrosion of galvanized steel. Includes 13 references, tables, figures.