What type of water must be delivered from lavatories and group wash fixtures in public toilet facilities?

Tempered water is the correct answer because it refers to water that has been mixed to a safe and comfortable temperature, generally around 90 to 100 degrees Fahrenheit. This temperature range ensures that the water is neither too hot nor too cold, providing a pleasant experience for users washing their hands. In public toilet facilities, especially in lavatories and group wash fixtures, it is crucial to deliver water at a temperature that promotes hygiene and encourages the use of handwashing, as excessively hot water can cause burns and cold water may deter people from washing their hands adequately.

In contrast, cold water alone might not effectively encourage handwashing practices and could hinder hygiene efforts. Hot water, while beneficial for certain applications, poses a risk of burns and is not typically suitable for handwashing in public settings where safety is a major concern. Filtered water is important for removing impurities and ensuring potability but does not address the temperature requirements for handwashing as stipulated by plumbing codes. Therefore, the focus on tempered water aligns both with user comfort and safety standards in public health initiatives.