How many inches of gravel must be placed above the distribution pipe?

The correct answer indicates that a minimum of 2 inches of gravel must be placed above the distribution pipe. This specific depth is important for several reasons. Firstly, having a 2-inch layer of gravel helps ensure adequate drainage and proper flow of effluent from the septic system, allowing for effective treatment and dispersal of liquid waste. This gravel layer also assists in protecting the distribution pipe from being crushed or damaged by the weight of the soil above, allowing the system to function without obstruction. Furthermore, the gravel aids in preventing soil from clogging the pipe openings, which is critical for maintaining the efficiency and longevity of the septic system.

Inadequate gravel coverage could lead to poor performance of the septic system, which can cause backups and other issues. Therefore, maintaining the recommended 2 inches is a standard best practice in septic system installation to ensure reliable operation and compliance with regulations governing septic systems.