Georgia Septic Installer Practice Test

For concrete drop boxes, the invert of the lateral holes shall be how much lower in elevation than the invert of the inlet?

1. 1/4 inch

2. 1/2 inch

3. 3/4 inch

4. 1 inch

The correct answer is: 1/2 inch

The appropriate elevation difference between the invert of the lateral holes and the invert of the inlet in concrete drop boxes is a 1/2 inch drop. This specification ensures that proper flow dynamics are maintained within the septic system. By allowing the lateral holes to be lower than the inlet, it facilitates gravity-assisted movement of effluent. A drop of 1/2 inch is generally considered sufficient to encourage appropriate drainage and prevent stagnation, which is vital for the effective distribution and treatment of wastewater in a septic system. The design choice is based on established engineering practices that consider factors like effluent flow rate and the prevention of backflow. If the lateral holes were not set lower than the inlet, this could lead to potential backflow situations, poor drainage, and even overloading of the system, compromising its efficacy and integrity.