Which of the following conditions is prohibited for discharging residential subsoil drainage systems?

Discharging residential subsoil drainage systems into the sanitary sewer is prohibited because it can lead to significant issues such as sewage overflows and backups. The sanitary sewer system is designed to handle wastewater from fixtures inside the home, while subsoil drainage systems manage excess groundwater. Mixing these two types of water can overwhelm the capacity of the sanitary sewer infrastructure, especially during heavy rainfall or flooding, leading to health hazards and environmental risks.

It is essential to properly manage subsoil drainage to prevent contamination of the sanitary sewer system. Properly directed subsoil drainage should ideally be routed to appropriate stormwater systems or to areas that can absorb or disperse the water safely, preventing the risk of flooding and allowing it to infiltrate into the ground.