What percentage of the total liquid depth should a pass-thru hole or slot cover in compartment partitions?

The ideal percentage for a pass-thru hole or slot cover in compartment partitions of a septic system is between a minimum of 25% and a maximum of 50% of the total liquid depth. This range ensures adequate flow and mixing between compartments while maintaining effective treatment of the wastewater.

Having a pass-thru that covers less than 25% can restrict the flow, potentially leading to improper treatment and separation of effluent. On the other hand, if the coverage exceeds 50%, it might compromise the function of each compartment, allowing solids and other undesired materials to bypass the necessary treatment processes. This balance is crucial to promote proper waste decomposition and to maintain the efficiency of the septic system.

This guideline helps in designing systems that function optimally, ensuring that wastewater flows effectively through the treatment phases, thus contributing to overall system performance and longevity.