What is a disadvantage of the grid system for water distribution?

• A. Primary Feeders
• B. Secondary Feeders
• C. Distributors
• D. Dead-end Water Mains

Answer: (D)

In this kind of system, the main idea is that looping the network adds redundancy and helps keep pressure stable, but it can still leave portions of pipe ending in a dead end. Those dead-end mains don’t receive flow from multiple directions, so water in those ends can stagnate, especially during periods of low demand. Stagnation means higher water age, lower disinfectant residuals, and potential taste or odor issues. It also makes flushing and maintaining those sections more challenging, because you can’t rely on cross-flow from other parts of the loop to keep the water moving. So, even in a grid layout, dead-end mains are a disadvantage because they can hinder water quality and complicate maintenance.