What is the minimum height for the discharge point of a sink water spout above the bottom of the sink basin?

The correct answer regarding the minimum height for the discharge point of a sink water spout above the bottom of the sink basin is 10 inches. This requirement is in place to prevent contamination of the water supply. By ensuring the water spout is positioned at least 10 inches above the bottom of the sink, it helps maintain proper drainage and prevents any unintended backflow of dirty water into the clean water supply.

The standard is based on the principles of plumbing codes aimed at protecting public health. The choice of 10 inches specifically is based on considerations about the vertical space needed to allow for splashing and other potential factors that might lead to cross-contamination if the spout were lower. This height provides a barrier that significantly reduces the risk of contaminants entering the fresh water system from the sink, thus adhering to safety regulations for water quality.

Other height options, while they may seem reasonable, do not meet the safety threshold necessary for preventing back contamination and thus do not adhere to the established plumbing standards.