A ___ would be least likely to require a RPZ to be installed as contaminant protection?

A single-family dwelling is least likely to require a Reduced Pressure Zone (RPZ) assembly for contaminant protection due to the nature of its water usage and potential hazards. In residential settings, the risk of backflow incidents that could introduce contaminants into the public water supply is significantly lower compared to commercial or industrial facilities.

In environments like sewage treatment plants, plating plants, and hospitals, the potential for hazardous materials and contaminants to affect the water supply is much higher. These facilities often handle substances that pose a significant backflow risk, necessitating the installation of an RPZ to ensure safe drinking water. In contrast, a single-family household typically uses potable water for daily activities like drinking, cooking, and bathing, and generally poses minimal risk of backflow contamination. Thus, the requirement for an RPZ for a single-family dwelling is not as stringent as for other types of facilities.