Georgia Septic Installer Practice Test

How many inches should the invert of lateral holes of concrete drop boxes be set lower than the inlet?

1. 1/8 inch

2. 1/4 inch

3. 1/2 inch

4. 3/4 inch

The correct answer is: 1/2 inch

The invert of lateral holes of concrete drop boxes should be set 1/2 inch lower than the inlet. This design requirement is crucial to ensure proper drainage and flow within the septic system. When the lateral holes are set lower than the inlet, it allows for effective gravity drainage, reducing the risk of backups and ensuring that wastewater is efficiently directed into the lateral lines. This height difference facilitates a smooth transition of effluent from the drop box to the drainage field, promoting the system's overall performance and longevity. Moreover, maintaining this specified measurement helps in managing the hydraulic load, which is essential for the proper functioning of septic systems. This specific height aligns with best practices in septic system design, ensuring that the lateral lines receive effluent in a manner that minimizes the potential for pooling and promotes adequate soil absorption.