Dumping, vandals to blame

MORE than a million sewer blockages were cleared by the Johannesburg Water sewer teams on a “jetting preventative programme” across the city in the last financial year (2017/18) with a total of 147 182 of these sewer blockages occurring in the Midrand/ Ivory Park area.

Nico de Jager, member of the mayoral committee for environment and infrastructure services visited the community of Ivory Park along Nkosi Street where numerous sewage bursts are experienced.

A “jetting” truck was used to unblock the sewer and a large jacket was found to be the cause of the blockage.

In 2003 the entity procured three of the current fleet of nine hydro jetting vehicles that are used to clean the sewer network. In the past year, the programme has led to more blockages being cleared since its inception.

The sizes of the jetting vehicles vary from the smallest with a jetting tank of 4 000 litres to the largest with a jetting tank of 12 000 litres. The jetting vehicles operate using a high-pressure water pump, able to generate up to 120 bars of water pressure at a flow rate of 300l/minute.

In the past where the preventative jetting had been done, the blockage rate decreased, said De Jager

“But, because there is a lot of vandalism and misuse of the sewer system – tyres, vehicle engine locks and solid refuse are dumped into the sewer system – the blockage rate does not necessarily remain low. Residents are encouraged to take care of their sewer infrastructure by not flushing or inserting foreign objects into the sewer network, which is ultimately their sewer network,” he said.