​​What is fly-rock?

Flyrock refers to the unintended ejection of rocks from blast holes due to fissures, cavities, or other weaknesses in the underground rock structure adjacent to the blast holes or faulty blast design.  Flyrock ejected from the top of the blast holes, as opposed to the face of the excavation much of which will be under water, is the potential problem in the Hidden Quarry.  Many jurisdications around the world require exclusion zones of 500 m for rock blasting operations, but here there are no standards meaning that the 19 houses, businesses, buildings and residents within the 500 metre radius are at risk, as well as cars, school and GO buses and other vehicular traffic along about a one and a half kilometre stretch of Provincial Highway 7, a busy commuter road in this area.  “Wild flyrock” also can occur, with incidents of rock being thrown 1000 to 1200 m having been reported.