Identification and Risk Assessment of Central Water Supply Systems – Case Study

Risk assessment of central water supply systems a case study. This paper presents methods for identification and risk assessment of central water supply systems, exemplified by a case study of the central water supply system in Luna locality, Cluj county during 2009-2010. System assessment was performed by means of previous data on water quality monitoring and water samples analysis for the parameters imposed by Law 458/2002 (audit monitoring) in the laboratories of the Environmental Health Center. The main risk identified at source was the significant water contamination with nitrates, in this regard results did not show significant change of the raw water quality (drain) over time. Occurence of nitrates in excess is of mixed origin in Luna water source, predominantly telluric net and accentuated anthropogenic due to agricultural practices in the area. In this respect, evolution of bacterial load was significantly related to the drain positioning in an intensively exploited agricultural area, the important increase of contamination being due to manure application on upstream lands. Two kinds of hazards were identified at the water treatment plant output and in the distribution network, as well as at the water source: contamination with nitrates and bacteriological contamination of faecal origin, the latter as a consequence of a completely inadequate chlorination. Water in the distribution network of Luna locality represents low health risks for small population groups (risk score 8), as characterized qualitatively on the basis of monitoring. The compliance plan for preventing effects targets the water source, treatment process, distribution network and health status indicators.