What is the minimum side wall depth required below the inlet of each seepage pit?

The minimum side wall depth required below the inlet of each seepage pit being 10 feet is significant for several reasons related to proper drainage and health standards. The depth ensures that effluent entering the seepage pit has sufficient space to disperse and percolate into the surrounding soil, allowing for adequate treatment as it travels through the soil layers.

A depth of 10 feet helps prevent the effluent from reaching the groundwater table too quickly, which can lead to contamination. Additionally, this depth assists in maintaining a safe level of treatment for the wastewater as it interacts with the soil, allowing natural filtration processes to occur effectively. This design standard is often dictated by local building codes and health regulations to ensure environmental safety and mitigate the risk of pollution.

The choices suggesting a depth of 5 feet, 8 feet, or 12 feet do not align with the established standards that consider hydraulic effectiveness and contaminant management. Each of these depths either is insufficient for adequate effluent treatment or exceeds practical implementation criteria, making the 10-foot requirement the most balanced and safe approach.