Under what condition should a serial distribution system be used?

A serial distribution system is particularly beneficial when the slope of the terrain prevents the use of conventional septic systems. This is because traditional septic systems rely heavily on gravity for wastewater to flow from the house to the septic tank and then to the drain field. In areas with steep or uneven terrain, conventional systems may struggle to function effectively, leading to issues such as backup or ineffective drainage.

In contrast, serial distribution systems use a series of distribution boxes or other mechanisms that help to manage the flow of wastewater across multiple trenches or areas. This setup can adapt more easily to the natural contours of the land, ensuring that the wastewater is evenly spread out and allowing for proper filtration and absorption into the soil.

The other situations proposed, such as a high water table, large residential properties, or distance from sewer lines, are not optimal conditions for a serial distribution system. A high water table could lead to groundwater contamination issues; large properties might be better suited for other septic designs that can handle the increased volume; and distance from sewer lines typically does not directly relate to why a serial system might be needed unless it also involves challenging terrain.