This tool promotes the drinking of tap water from reusable bottles in public catering. The quality of tap water is high in many countries, and can be consumed instead of bottled mineral water. Drinking tap water saves money and supports human wellbeing through healthy water consumption. The climate impact of the practice is about 600 times smaller than that of consuming mineral water. This provision can be included in public procurement policies, and catering services can switch to using reusable bottles to help support it. This practice aligns well with policies for climate protection and public health.