Following an explosion that damaged about five blocks of Bree street in the Joburg CBD a multi-disciplinary team visited the site to assess the extent of the damage. Dog units scoured the streets as Egoli Gas and police officials worked the area. Picture: Timothy Bernard / African News Agency (ANA)
The City of Johannesburg has announced that all underground pipelines will be shut down to allow full inspection of existing infrastructure.
The existing underground pipeline on Bree Street (Lillian Ngoyi Street) includes infrastructure for Egoli Gas, Telkom, City Power, Joburg Water - who have sewer and water pipelines, and Sasol, to name a few.
All companies and public entities reported to the operations command centre that their infrastructure was in tact, but they have now all been told to restrict supply to ensure the necessary inspections to take.
During a media briefing from the command centre in Newtown, Joburg city manager Floyd Brink said natural gas reticulator, EGoli Gas, had been ordered to shut down its underground gas pipelines in the inner city within the next two hours.
Brink said Joburg Water and City Power had also been ordered to shut down their infrastructure in the inner city.
Brink explained that the cause of the explosion was likely from three possible scenarios.
“At this stage, our preliminary investigations have presented us with three possible scenarios for the explosion.
These are:
– an ignition of methane gas in underground storm water systems due to sewerage ingress;
– the ignition of natural gas, mixed with air in underground storm water drainage systems or service ducts;
– the ignition of gas from a gas pipe burst.
“At this stage only one of the above potential causes appear to be warranted, accidental leakage of natural into the service duct reaching explosion concentration levels of 5-15% and was ignited by a source unknown at this stage.
“The source of gas in the service duct is unknown. Investigations in this regard will continue to try locate the source over the next few days,” said Brink.
Brink said to mitigate against the services being shut down in the inner city, water tankers and mobile toilets would be provided for residents in the area.
He also said no evacuations were necessary as all buildings were still structurally sound after the explosion.
Brink said they were taking the step to shut down all underground infrastructure to allow technicians an opportunity to assess along the 400 metre pipeline which has been affected.
Brink also said technical teams would tomorrow use pressure fans to blow out any excess gas which remained before teams were expected to physically inspect.
He also said the city officials had been using “world class“ advanced technology to identify underground defects underneath the surface of the roads that are still intact and unaffected at this stage.
Joburg EMS would also have a fire engine on standby to be able to respond swiftly to any eventualities, should a need arise.
“I wish to emphasize that the tasks we are undertaking are complex and at this stage will have to be handled with due care, and that no heavy equipment can be deployed to the site immediately.
“The digging and trenching to be done now will have to be done by hand until we are confident the site is safe and all hazardous factors are cleared,” he said.
City Power’s general manager for the service delivery centre, Charles Mohlaka, said they had already turned off the electrical supply into the area and would only restore it once the area had been declared safe.
Earlier, Gauteng Premier Panyaza Lesufi ordered the JMPD and SAPS to fence off the area with barbed wire to limit the number of people in the area.
Brink added that 250 law enforcement officers, which include 50 security officers, would be deployed to the area to ensure the area.
Brink said they were reluctant to bring in any heavy machinery yet and it was unclear how long it would take for the situation to return to normalcy on Bree Street and the inner city.
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