Recycled water is not used for which of the following?

Recycled water is water that has been treated to remove impurities and can be reused for various purposes. It is commonly employed for irrigation and cooling systems, as these applications do not require water to meet the same safety standards as potable (drinking) water.

In the case of potable water, it necessitates a much higher level of treatment and quality assurance to ensure safety for human consumption. Recycled water, unless it undergoes rigorous additional treatment processes that meet strict regulatory standards, is typically not considered safe for drinking. Therefore, it is accurately identified that recycled water is not used for potable water because of the stringent health and safety regulations governing drinking water quality.

For fire protection systems, while some may use treated water, many systems also rely on potable water to ensure safety in all circumstances. Thus, the most straightforward answer regarding where recycled water is not typically utilized is for potable water, due to the health risks associated with less-treated water standards.