Georgia Residential Contractor Practice Exam

When water supply lines are within 10 feet of absorption lines, what must be ensured regarding their position?

1. They must be 6 inches below ground

2. They must be 12 inches above the aggregate

3. They must be at ground level

4. They must be encased in concrete

The correct answer is: They must be 12 inches above the aggregate

The requirement for water supply lines to be positioned at least 12 inches above the aggregate when they are within 10 feet of absorption lines is primarily a matter of preventing contamination of the water supply. Absorption lines are associated with septic systems and can emit contaminants into the surrounding environment. Having the water supply lines elevated helps to ensure that any potential leachate or contaminants from the absorption lines cannot easily reach and infiltrate the drinking water supply. This elevation provides a crucial safeguard by creating a buffer zone, reducing the risk of backflow or cross-contamination that could occur if the two systems were to interact directly. Maintaining this distance above the aggregate further contributes to the protection of drinking water quality and public health. In contrast, other options do not meet the necessary protective criteria or fail to address the contamination risks posed by proximity to absorption lines, which is central to the regulation and best practices in residential construction and plumbing systems.