Which of the following accurately describes the gravel placement in a septic trench?

The correct choice outlines the recommended gravel placement in a septic trench, which is essential for effective drainage and filtration. When installing a septic system, it's crucial to have the appropriate depth of gravel to allow for the proper treatment of the effluent as it percolates through the soil.

In this context, having 2 inches of gravel above the pipes promotes adequate coverage and protects them from soil intrusion, ensuring that the effluent can disperse evenly. Additionally, a depth of 6 inches below the pipes provides sufficient space for effluent to filter downwards through the gravel layer and into the soil. This depth ensures that the filtration process occurs effectively, allowing the effluent to treat contaminants before entering the surrounding soil.

Following these guidelines helps to prevent clogging and supports the overall efficiency of the septic system. Proper gravel placement is crucial in maintaining the functionality and longevity of the septic installation.