Georgia Septic Installer Practice Test

What is the minimum percentage of the total volume of a septic tank that must be above the liquid level?

1. 10%

2. 15%

3. 20%

4. 25%

The correct answer is: 15%

The requirement that a minimum percentage of the total volume of a septic tank must be above the liquid level is based on the need for proper treatment and the effectiveness of the septic system. This portion of the tank allows for crucial functions such as aeration, venting, and reducing the amount of scum that can accumulate at the surface. Having at least 15% of the tank above the liquid level ensures there is enough space for gases to escape and helps maintain a balance between the liquid and solid waste, which is essential for the treatment process. This requirement also supports operational efficiency and helps prevent the tank from becoming overloaded, which could lead to system failures or back-ups. The other percentages provided do not meet this balance, as they either allocate too little space for operational purposes or exceed practical limits that would interfere with the tank's intended function. Therefore, the stipulation of 15% is established as the minimum necessary to ensure the septic system operates effectively and efficiently.