Quantitative risk assessment in the Water Safety Plan: case studies from drinking water practice

摘要

System assessment is the part of the Water Safety Plan that evaluates whether a water supplynsystem is capable of producing drinking water that meets the health-based targets. Systemnassessment can be done at increasing level of detail, requiring more site specific informationnas the level of detail increases. Four case studies are presented with increasing level of detail,nshowing the type of information that is required for each of these levels and how each levelninforms risk management. The first case study shows how a system assessment can benperformed without other site specific information than the type of source water and the typenof treatment processes. The required data for the system assessment are collected from thenlarge body of literature available. The second case study uses site specific microbial indicatorndata. The third study uses pathogen data and the fourth case study combines data on pathogens,nmicrobial indicators and process parameters. The case studies show that the level of detailnrequired largely depends on the risk management question.