What is the minimum trench depth allowed for a standard soil absorption system?

The minimum trench depth allowed for a standard soil absorption system is typically set at 18 inches. This depth is important because it ensures that the effluent from the septic system has adequate contact with the soil, which is essential for effective treatment and absorption. The trench provides a suitable environment for microorganisms in the soil to break down the organic matter in the effluent, ultimately leading to cleaner water entering the ground. Additionally, the 18-inch depth helps maintain soil temperature and moisture levels that are conducive to the microbial processes necessary for proper wastewater treatment. This standard promotes the longevity and efficiency of the septic system by minimizing the risk of system overload and ensuring adequate filtration before the effluent reaches the groundwater.