This tool is intended to support the practical application of the guidance presented in the Water safety plan manual: step-by-step risk management for drinking-water suppliers, second edition (WHO & IWA, 2023). Refer to Module 2 in the manual for detailed guidance.

The checklist below supports water safety plan (WSP) teams with describing the water supply (Module 2). It includes key information to consider and summarize when describing each stage of the water supply, including:

• general system information (including equity- and climate-related aspects);
• source (including surface water and groundwater aspects, and the catchment);
• treatment;
• distribution and storage;
• user practices (including buildings);
• water safety aspects (e.g. national drinking-water quality regulations and standards, historical water quality data, customer notifications and complaints); and
• known or potential problems in the system.