In municipal water distribution, which term refers to a medium-sized main that serves as a feeder between large trunks and smaller lines?

• A. Intermediate main
• B. Distributor
• C. Trunk line
• D. Secondary feeder

Answer: (D)

In municipal water distribution, mains are organized in levels: trunk mains carry large volumes across wide areas, feeder mains step down from the trunks, and smaller distribution or service lines branch off further downstream. The term that describes a medium-sized main acting as a feeder between large trunks and smaller lines is secondary feeder. It occupies that middle tier, taking water from trunk lines and delivering it to the smaller feeders or distribution mains, helping to balance pressure and supply across zones. The other terms refer to other parts of the network: a trunk line is the largest main, an intermediate main isn’t the standard label for this tier, and a distributor typically denotes lines that feed zones without specifying this middle tier.