Georgia Septic Installer Practice Test

What kind of materials can be approved to be placed above the aggregate on the perforated pipe?

1. Plastic sheets

2. Pervious building paper or straw

3. Concrete blocks

4. Sand

The correct answer is: Pervious building paper or straw

Pervious building paper or straw is approved for placement above the aggregate on the perforated pipe in septic systems. This is because these materials allow for the passage of water while providing a barrier to prevent fine soil particles from clogging the perforated pipe. Maintaining proper drainage and aeration through the perforated pipe is essential for the efficient operation of a septic system. The pervious nature of building paper and straw ensures that liquid effluent can move freely through the soil while still providing adequate filtration. Other materials, like plastic sheets, can hinder drainage rather than promote it, leading to potential backups or system failure. Concrete blocks are too rigid and impermeable, which would obstruct the flow of effluent as well. Sand, while sometimes used in certain applications, is not effective in managing the flow and filtering as well as pervious building paper or straw. Thus, the correct answer recognizes the need for both permeability and filtration in septic system design.