When drainage engineers usually investigate blocked sewers they commonly find the build up of fat or other common sewer debris is the cause of the sewer problem. However, rarely they sometimes find something which cannot be removed by common drain unblocking techniques.
A road in Urmston, Manchester is expected to remain closed for around six weeks after a sewer was completely blocked by concrete.
The 25 metre section of pipe was investigated by local waste water company United Utilities after residents complained that their cellars were flooding. Upon further investigation using CCTV technology, the water company found that the sewer was almost completely blocked by concrete, which had been poured down the sewage pipe.
Drainage engineers now face the tough challenge of removing the concrete from the 21 inch diameter sewer, a task that they estimate may take up to around two months to complete.
The section of sewer damaged runs under Flixton Road in the town centre.
When a sewer is blocked by standard debris drain unblocking techniques such as drain jetting can be employed by the drainage experts. However in cases such as the above there is little the sewer engineers can do except excavate the damaged sections of pipes.