Shocking blast 'within limits'
Tuesday, 26th March, 2013
By Erica Visser
The Environmental Protection Authority (EPA) is investigating a CBH mine blast that shook the city on Sunday night.
It's not the first time the EPA has looked into the company's activities, after receiving dozens of complaints from residents since mid last year.
However, the blasts at the Rasp Mine, situated beneath the city's CBD, are yet to be recorded as exceeding licensing limits.
In response to the criticism, the company promised to reduce the duration of underground firings in January.
CBH's general manager, Tony Davis, said yesterday that the fact that the blast had occurred slightly later than usual did not impact on its intensity.
"There were a few difficulties in charging it so it was a little bit delayed," he said.
"The thing is once you've got it ready to go it's unsafe to leave it there for any period of time."
He said that the blast was within the acceptable limits.
"It was still within limits, it was just one of these blasts that seemed to get a higher vibration reading than some of the others," he said.
"All our blasts are within the limits, those blasts are set by the regulators and set based on years and years of data on what can cause damage.
"We've had people's houses assessed and there's been no issues that can be attributed to mine blasting.
"Our aim is to not exceed our internal limits, which are well inside our licensed criteria.
"Unfortunately that depends on the structure and rock type, it's science but it's not as exact as we like."
However, Mr Davis said that the company had succeeded in toning down its blasts since the complaints last year.
"During the last few months our blasting performance has been excellent," he said.
The EPA has said previously that its policing of mine firings do not extend to preventing damage to local property, only the amenity of the city.
A spokeswoman for the EPA said yesterday that the authority had been alerted to the blast, which occurred at 7.10pm, and was looking into it.
The EPA can be used to report pollution, including noise pollution, on 131 555.