Lafarge issued a letter of apology and explanation to neighbours of the Pitt River Quarry for a massive blast on Wednesday.
The blast blew open the doors of nearby homes and left some people with ears ringing – at least that was the talk at the rally against a second quarry on Sheridan Hill which took place later that night.
The letter explained that unforeseen changes in the weather and air pressure resulted in a much louder blast than anticipated.
Cloud cover dropped after the blast was loaded, and the wind picked up.
“We noticed these change in conditions. But since we had already started loading the blast, it is best practice [safety wise] to let the blast go instead of letting mixed explosives sit overnight,” said the letter.
The company said the air pressure was outside acceptable tolerances for Lafarge, which it says are more stringent than B.C. Mines.
“For this we apologize, and would like to make a commitment to you, our neighbours, that we will look at improvements to our blasting set up on this ridge to reduce the overair pressure.”
Lafarge said it has tried to “improve our impact on our neighbours” in several ways:
• going from five smaller blasts per week to one larger blast;
• directed the shockwave from blasts toward Pitt Lake, ad away from houses;
• stopped flyrock from blasts;
• operates one shift, leaving the site at 5:30 p.m., instead of two shifts;
• upgraded equipment, allowing more rock to be crushed during manufacturing, to minimize noise.