With most conventional onsite systems, flow from the septic tank is via gravity with the goal of even distribution across the soil treatment area. Flows can be split through perforated piping and rock, synthetic media or hollowed-out chambers, and other mechanisms. Because soil drainfield size is partly flow-volume dependent, equal distribution across the soil drainfield is crucial to properly treat wastewater and preserve the life span of the soil. “Even distribution” includes both even flow volumes split between trenches/beds and even longitudinal dispersal across the length of each trench/bed.
Importantly, systems are sized with the assumption that even distribution is achieved.
