The biological safety of distribution systems following UV disinfection in rural areas in Beijing, China

Abstract

In rural areas, UV disinfection has a great potential for drinking water treatment because of the ability to achieve target disinfection levels and the ease of operation and maintenance; however, UV disinfection provides no disinfection residual to the water distribution system. This study examines the biological safety of rural water distribution systems following UV disinfection. The results showed that in all the tested villages, heterotrophic plate counts (HPC) were below 500 colony-forming units (CFU)/mL and total bacterial counts (TBC) were below 100 CFU/mL. Both meet the drinking water standard in China. The HPC concentration was related to the water temperature, the assimilable organic carbon (AOC) and water distribution system conditions. Total coliforms were detectable at some water distribution system sampling points in two out of eight villages.