August 11, 2003
By Tammy O'Reilly
THREE hi-tech tankers have been bought by Johannesburg Water to tackle the problem caused by more than 3000 blockages to the City's sewer network every month.
Johannesburg Water (JW), the company responsible for providing water and sanitation services to the City, showed off its new acquisitions to the media this week. The Hydro Jetting Vacuum tankers, priced at R2-million each, are able simultaneously to jet clean and vacuum blockages.
The causes of blockages to the sewer network differed from area to area, JW said. Primary causes of blockages in the northern suburbs were roots growing into the pipes or, in the township areas, sand filtration.
Most blockages occurred in the northern suburbs. "This," said JW spokesperson Jameel Chand, "can be attributed to the fact that there are more trees in the suburbs." Areas, such as Sandton, where there were many restaurants experienced blockages caused by the fat used in preparing food.
These problems could now be tackled by the Hydro Jetting Vacuum tankers, which made use of state-of-the-art technology. "The tankers are manufactured by a Dutch company, but the assembling takes place here in South Africa," said Lloyd Teasedale, environmental manager at JW.
"The new hi-tech vehicles will compliment the company's existing sewer maintenance programmes, well as enhance JW's commitment to environmental protection," Chand added.
During the demonstration in Bryanston, the media were shown how a 120m jet hose, situated at the back of the 8 300 litre clean water tank, created an upstream thrust, then the vacuuming component was used to suck up the debris created by this action into a separate built-in tanker.
Close-circuit television cameras were lowered into the sewer to detect and monitor the progress of the removal of blockages.
The company, operations manager Andrius Lotz said, had identified three "hotspots". Statistical data showed that Ferndale, Bryanston and Diepkloof were major problem areas.
Compared to other cities around the world, Johannesburg was at a disadvantage. The City had developed in an area with limited water resources. "This has a bigger impact on the system compared to other cities, and therefore our standards have to be among the highest in the world," said JW operations executive, Jean Pierre Mas.
The company was pleased with the results of its wastewater treatment works programme, Mas added. "We are now 95 percent efficient in dealing with waste water, 10 percent up on the 2000/20001 statistics."
Residents wanting to report blockages can call Johannesburg Water's 24-hour help line on (011) 688 1500.
