Blasting

Blasting is used to essentially break minerals and aggregates off a rock face so they can be collected and processed. It is obviously an activity that is handled very carefully to ensure safety, and to minimize impacts on the environment and neighbouring properties.

Blasts are carefully designed to ensure they are as efficient as possible – so they use as little explosive and generate as little noise and dust as possible, while still freeing enough rock to meet operational needs. They are also designed to ensure rock generally falls straight down, within a few metres of the blast, both for safety reasons and because it is more efficient for collecting material afterwards.

New technologies, such as digital blasting, have also made blasting more precise, allowing companies to reduce the amount of explosive they use and impacts on surrounding areas.

Blasting cannot take place within 30 metres of watercourses and roads, and not within 800 metres of neighbouring buildings such as homes and commercial buildings.

Ground vibrations from a blast are generally limited to 12.5 mm/sec. around neighbouring buildings. This is roughly the equivalent vibration caused by closing a sliding door in your home (i.e. 10 mm/sec.), and less vibration than what is caused by slamming a door (i.e. 17 mm/sec.). A person jumping creates ground vibrations of about 14 mm/sec., more than what is allowed around neighbouring buildings from a mine or quarry blast.

The air blast/concussion generally cannot exceed 128 dBA (A-weighted decibels) to ensure buildings on neighbouring properties are not harmed. That is about the same volume as a chainsaw, but unlike a working chainsaw, a blast is over in a few seconds.

Blasting cannot take place on Sundays, statutory holidays or after 6:00 p.m.