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

The maximum trench depth for a standard soil absorption system is 36 inches. This depth is established to ensure that the septic system can function effectively while providing adequate treatment and drainage of wastewater. Trench depths that exceed this measurement could lead to issues such as reduced oxygen levels in the soil, which are critical for the aerobic bacteria that help in breaking down organic matter in the effluent. Additionally, deeper trenches may encounter unsuitable soil conditions, such as high groundwater levels or bedrock, which can hinder the system's performance.

Choosing a maximum depth of 36 inches strikes a balance between maintaining enough soil for effective treatment and avoiding complications that arise with deeper installations. This limitation also helps in ensuring compliance with health and safety regulations that govern septic system installations.