Georgia Residential Contractor Practice Exam

How far must absorption lines be set back from surface drainage ditches?

1. 10 feet

2. 25 feet

3. 50 feet

4. 20 feet

The correct answer is: 50 feet

Absorption lines, which are used in wastewater management systems such as septic systems, must be set back a certain distance from surface drainage ditches to ensure the proper functioning of the system and to protect water quality. Setting absorption lines back 50 feet from surface drainage ditches helps to prevent contamination of the surface water and groundwater. This distance minimizes the risk of pollutants being washed into nearby bodies of water during heavy rain or flooding, mitigating potential environmental harm. The reasoning behind this requirement is based on hydrology and water flow patterns. Water moves through soil and sediment, and any disturbance or system malfunction from the absorption lines too close to surface drainage can lead to inadequate treatment of wastewater, increasing the risk of contamination. The 50-foot distance is generally considered a sufficient buffer to allow for the natural filtration processes that occur in the soil. In contrast, shorter distances such as 10 feet, 20 feet, or 25 feet may not provide adequate protection and filtering capability, potentially leading to environmental issues and non-compliance with regulations aimed at safeguarding water resources. This explains why the specific requirement of a 50-foot setback is critical in residential and commercial construction, particularly in areas where drainage ditches are present.