North Carolina Septic Installer Practice Exam

The function of a septic tank primarily revolves around the separation, storage, and treatment of wastewater before it exits into the drain field. One of the key responsibilities of a septic tank is to separate liquids from solids, allowing the solids to settle at the bottom where they can be anaerobically digested by bacteria, thus showing microbial activity. This biological process reduces the volume of solids over time and prevents them from clogging the system.

A septic tank also serves as a storage area for the accumulation of solids, allowing for periodic pumping and maintenance. However, the septic tank's design does not include a disinfection process for the treated water. Disinfection typically occurs after the septic tank, within the subsequent treatment systems, such as a drain field or other advanced treatment options.

Therefore, the correct understanding of a septic tank's capabilities confirms that disinfection of treated water is not one of its functions.