What is the minimum horizontal separation distance required between water service pipe and the building sewer?

The minimum horizontal separation distance required between water service pipes and building sewers is specified in plumbing codes to ensure both systems operate safely and effectively without risking contamination. A distance of 5 feet is required to minimize the possibility of cross-contamination through leaks or breaches in either the water service pipe or the sewer line. Maintaining this separation helps to protect the potable water supply from potential sewage contamination, which is crucial for public health and safety.

The additional distances mentioned in the options that are either shorter or longer than 5 feet are not compliant with code requirements. Shorter distances could increase the risk of sewage entering the drinking water supply due to potential leaks or failures, while greater distances are not typically necessary for safety standards, making 5 feet the optimal standard in most codes.