The Water Safety Plan (WSP) is about protecting water quality from catchment to the tap. Promoted by the World Health Organization, WSP has changed the way water supply systems are managed. This report documents the pilot application of the guidance note for mainstreaming WSP in water projects supported by the Asian Development Bank as piloted in the Chongqing Municipality in the Peoples' Republic of China. The guidance note seeks to promote systematic assessment and management of water safety risks from infrastructure construction to operation. The pilot concluded that WSP could be effectively integrated into the Asian Development Bank's project preparation with careful scoping, planning, and evaluation. The report also summarizes challenges and lessons learned from the pilot.