What is the minimum height that the invert of the inlet should be above the liquid level in a septic tank?

The minimum height that the invert of the inlet should be above the liquid level in a septic tank is crucial for the proper functioning of the system. When the invert of the inlet pipe is set at least 2 inches above the liquid level, it helps ensure that wastewater flows into the tank effectively without causing backflow or creating a situation where the incoming flow is undercutting the settled solids. This distance also allows for adequate ventilation and reduces the risk of clogging.

Setting the inlet at this specified minimum height is a best practice in septic system design, contributing to the tank's ability to function properly and ensuring the separation of solids from the liquid. It also helps prevent scum layer disruption, which is vital for proper anaerobic digestion within the tank. By adhering to this standard, the longevity and efficacy of the septic system are enhanced, preventing potential issues that could arise from improper installation.