Name one common septic system design.

The designation of conventional gravity-fed systems as a common septic system design is accurate because this type of system utilizes the natural force of gravity to facilitate the flow of wastewater from the home to the septic tank and then from the tank to the drain field. The conventional design is widely used due to its simplicity, cost-effectiveness, and suitability for many types of soil conditions.

In a typical conventional system, wastewater travels through pipes that are sloped downward, allowing it to move freely without the need for additional mechanical components like pumps. This basic function meets the needs of a wide range of residential properties and is typically the first choice in areas where site conditions allow for effective soil drainage and percolation.

Each of the other designs listed serves specific functions or is used in particular circumstances, making them less common in standard installations. For instance, mound systems are often employed in areas where the soil is unsuitable for conventional systems, while interceptor systems and reed bed systems are generally used for specialized cases or more advanced treatment methods.