Assessment of safety in drinking water supply system of Birjand city using World Health Organization’s water safety plan

Background: The conventional method for managing drinking water quality is not a suitable preventive strategy for protecting public health. A water safety plan (WSP) presents a systematic approach to ensuring the health and quality of drinking water. This study assessed the drinking water supply system safety of Birjand city using the WHO's WSP. Methods: This investigation employed the WSP-QA Tool and the WSP manual of the WHO and the AWI. For this purpose, software checklists were prepared and, after confirmation of content and face validity, completed based on Birjand's water and wastewater company records and interview with company's experts. Data was analyzed using WSP-QA Tool. Results: From total possible 440 points for full use of the program and 328 points of the studied phases, a score of 190 was acquired, indicating a 43.18% coordinated implementation with WSP. System description and management procedures showed the maximum and minimum percentages of congruency with the WSP of 87.5% and 25%, respectively. Among the components of the water supply system, water resource had the most attention. Conclusion: As regards the percentage of overall WSP-phase implementation and the low attention given to some key parameters of the water supply system, such as risk assessment and management procedures, the system currently enjoys a relatively medium level of safety. However, the high points of some phases such as system description, operational monitoring and verification enhance the system's flexibility for changing the current approach of qualitative management to the WSP.