Before revision: Operation and maintenance Good operation and maintenance (O&M) is essential for the long-term sustainability of any sewerage system, but particularly for simplified sewerage, since the low diameter of pipes and low gradients make the system more vulnerable to clogging.
After revision: Operation and maintenance Good operation and maintenance (O&M) is essential for the long-term sustainability of any sewerage system, but particularly for simplified sewerage, since the small diameter of pipes and low gradients make the system highly vulnerable to clogging.