Which system is known as the first type of underdrain system with a central manifold pipe?

• A. Pipe lateral collectors
• B. Perforated drain system
• C. Slotted underdrain
• D. Gravity-fed system

Answer: (A)

The first type of underdrain system with a central manifold pipe is the system involving pipe lateral collectors. This design features a main pipe, or manifold, that collects and distributes water from various lateral pipes that run perpendicular to it. The evolution of this system allows for efficient drainage by channeling water away from the treatment area more effectively.

Pipe lateral collectors are particularly advantageous in water treatment processes as they can manage large volumes of water from the surrounding filters or settling basins, ensuring that the treated water is effectively gathered and removed. Their structure facilitates the distribution of flow, allowing for uniform collection and reducing the risk of blockages or uneven water levels in the treatment facilities.

In contrast, other systems mentioned, like the perforated drain system and slotted underdrain, use different configurations and do not feature a central manifold. While they may serve similar drainage purposes, they do not represent the historical development of underdrain systems in the same way as pipe lateral collectors do. The gravity-fed system, though related to the movement of water, typically focuses on using gravity alone to transport water without the specific architecture that defines the lateral collector system.