Exaggerated flow pattern of effluent in the start up of a Title 5 system with leaching chambers.

Early stage of biomat formation, still resulting in uneven and locally high hydraulic loading.

Still later stage of progressive biomat formation, continuing to show some areas of high hydraulic loading. Some flow is evened out by passage through existing biomat.

Idealized final stage of biomat formation. Ideally, the biomat covers the entire infiltrative surface, evening out the vertical flow to groundwater, yet not being hydraulically restrictive to the point where there is excessive ponding of effluent on top of the biomat.