Georgia Residential Contractor Practice Exam

How should the aggregate be filled above the perforated pipe in an absorption field?

1. 0 inches

2. 1 inch

3. 2 inches

4. 3 inches

The correct answer is: 2 inches

The recommendation to fill the aggregate above the perforated pipe in an absorption field by 2 inches is based on standard practices in septic system design. This amount of aggregate above the pipe serves a critical role in ensuring effective wastewater treatment. The 2-inch depth helps facilitate proper drainage while still allowing the surrounding soil to absorb and filter the effluent. Adequate coverage is essential to protect the pipe from damage and is also important for preventing sediment from entering the pipe, which could lead to clogs over time. Moreover, this depth strikes a balance between ensuring that the effluent is not too close to the surface, which could lead to odors or surfacing issues, while also allowing for optimal treatment as the effluent percolates through the gravel, into the soil, and eventually to the groundwater. Too little aggregate may not adequately protect the pipe or support effective filtration, while too much may hinder the system's proper function. Therefore, 2 inches is the established best practice in this context.