https://www.who.int/water_sanitation_health/publications/water-safety-quality-assurance/en/
[Accessed: 18.06.2019]
The WSP Quality Assurance Tool, jointly developed by WHO and the International Water Association (IWA), with support from AusAID, DWI (UK), MHLW (Japan) and NSF International. It facilitates an objective assessment of efforts in water safety planning, the approach recommended by the WHO Guidelines for Drinking-water Quality to ensure consistent supplies of safe drinking-water. It systematically highlights the areas in a WSP where progress is made and where opportunities for improvement present themselves.