Water Safety Plans: A Hazards Analysis Approach to Understanding Water Systems

Background: Water systems design, operation and maintenance has been identified as one of the most effective ways to achieve safe drinking water and in 2004 the WHO introduced Water Safety Plans (WSP) as part of the new Guidelines for Drinking Water Quality. The WSP process is an iterative approach which bases management decisions on the assessment of risk and the implementation of these decisions can result in incremental improvements in water quality. WSP are based on preventative risk management which is a systems approach to understanding the causes of poor water quality. A WSP involves a comprehensive understanding of the system in its entirety and the underlying interactions and relationships which provide the foundation for understanding risk, including identifying contributing factors and environmental antecedents. This systematic approach leads to a clearer understanding of problems in the entire water system which leads to a better understanding of water quality variability, relationships between risk factors and contamination, how these relationships cause variability in water quality, and how to maintain system integrity.

Results: The CDC conducted several water safety plan pilots. Preliminary studies assessed the process to compare to several other water safety plans developed throughout the world resulting in the development of an evaluation framework to better assess the water safety plan process.

Conclusion: In order to properly utilize the risk-bases WSP approach, the evaluation process includes health and non health factors that could impact the costs and benefits of a program.