Vibrations caused by quarry blasting will be strictly regulated in a new set of guidelines that place responsibility on the owner and an independent monitoring consultant.

If the vibrations are higher than permitted the owner will have to explain what happened

The new guidelines, which will be entrenched in the quarry’s environment permit, establish a radius of 200 metres around the blast site within which the vibrations will be monitored.

Aimee Brincat, an environment protection officer at the planning authority, explained that while monitoring of vibration from quarries already existed, the distance had never been set.

Once situated in the remote countryside, many quarries have now become the bane of residents living close by who complain about the dust and smells generated on site.

However, the majority of complaints received by the authority are related to vibrations caused by blasting, which uses explosives to extract large blocks of stone. The explosion creates a huge displacement of air, referred to as air overpressure, which is often felt by nearby residences through the rattling of windows, for example.

The guidelines also establish a maximum value of air overpressure dispersion which cannot be surpassed.

Blasting can only take place with a police permit, issued after consultation with the resources and planning authorities. It is regulated by the Explosives Ordinance Act and, once the permit is approved, the army hands the explosives to the operator. There are 22 quarries licensed to blast – of these only 12 actually do so, Ms Brincat said. “The old regulations didn’t specify the design of the blast or monitoring techniques”.

Under the new regulations, quarry owners have to submit a method statement to the planning authority which clearly pinpoints the location of the blast and the mitigation methods used.

Blasting on site can only start after the planning authority approves the method statement. Owners will also have to appoint independent and qualified consultants who will oversee the blast and monitor the vibrations. After the blasting, the owner has to submit the monitoring report to the planning authority within five days.

The values in the monitoring report would be measured and calculated by machines and uploaded on the planning authority’s website.

If the vibration values are higher than permitted, the owner “will have to explain what happened – there are a number of factors that might affect it, such as cloudy weather and what mitigation measures he will use,” Ms Brincat said.

Ultimately these regulations will be listed in the environmental permit so a failure to comply with the set standards will have consequences.