Piping that has been used for another purpose cannot be used for water distribution.

• A. Gas distribution
• B. Water distribution
• C. Sewage distribution
• D. Air distribution

Answer: (B)

The main idea is that piping for drinking water must be dedicated to potable service and made of materials approved for drinking water. If a pipe has previously carried something else, residues, contaminants, or materials that aren’t compatible with potable water can remain inside or on the surface, posing a contamination risk. Because of that, piping that will carry water should be new or specifically rated for water distribution, not repurposed from another service. Gas, sewage, and air piping are all different services with materials and joints not suitable for drinking water, so the emphasis is on using piping designated and approved for potable water—hence water distribution is the best choice in this context.