All Durham soil and waste systems are required to be of which drainage type?

Durham soil and waste systems are required to be of a recessed drainage type to ensure effective handling of waste and drainage flow. This design helps minimize the risk of clogs and backups, as recessed systems are specifically engineered to allow for better flow characteristics and reduce the accumulation of waste materials.

By using a recessed design, these systems enhance the overall efficiency of drainage in plumbing applications, preventing issues that could lead to significant maintenance problems or health hazards. Other drainage types, while they may serve different functions, do not meet the specific requirements and performance standards set forth for Durham systems, making recessed the preferred and compliant choice.