Georgia Septic Installer Practice Test

What is the minimum depth of aggregate required for a Wisconsin mound system?

1. 6 inches

2. 9 inches

3. 12 inches

4. 15 inches

The correct answer is: 9 inches

In a Wisconsin mound system, a minimum depth of 9 inches of aggregate is essential for the effective functioning of the system. This depth ensures that the effluent from the treatment process has enough medium to filter through, allowing for adequate absorption and treatment of wastewater. A proper layer of aggregate helps to maintain appropriate aeration and drainage, which are critical for the microbial processes that treat the effluent. Moreover, the 9-inch depth is designed to balance the structural integrity of the mound while providing sufficient contact area for the effluent, facilitating a reduction in pathogen and nutrient concentrations before the water interacts with the surrounding soil. This specification helps ensure compliance with environmental standards and promotes the overall efficiency of the wastewater treatment system.