September 27, 2013 - 7:03 PM
KAMLOOPS – The city is concerned about the damage to buildings and people from the airborne shock waves that will be generated by blasting at the proposed Ajax mine.
The concern is about the lack of air blast requirements included in the application information for the copper mine. On Tuesday council will take a look at the most recent correspondence from Golder Associates about the air blasts.
An air blast is caused when the pressure wave from an explosion travels through the air faster than the speed of sound. The pressure wave or shock wave travels at supersonic speed and eventually decays into an ordinary sound wave the further it gets from the blast.
City staff asked the engineering company to provide an opinion on whether test blasts were a necessary component of the assessment process after staff continued to hit a wall with the province when it came to requesting air blast impacts be included in the requirements.
In a letter dated earlier this month the company reiterated their stance on the need for the potential impact from air blasts to be included.
“It is our opinion that air blast is a key issue that should be included in the Ajax environmental assessment, considering the blast management plants that will be applied,” Senior Geotechnical Engineer Bruce Bosdet says in the letter.
He also explains that air blasts can cause more distress and damage than ground vibrations to persons and wildlife.
Earlier this month, KGHM brought in an expert on blasting to speak at public information sessions about the proposed mine. Frank Chiapetta discounted concerns over air blasts, saying they can adjust the blasting to reduce effects on neighbours, which would be minimal to begin with.
“I'm very confident in these projections,” he told the room of 30 at the final session. “There's not too much we can't do with blasting. We just adjust for the conditions.”
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News from © InfoTel News Ltd, 2013