Dust levels and the impact of dust is a contentious issue
How will Fulton Hogan continue to monitor its dust levels over the quarry’s lifetime?
Fulton Hogan is working through the logistics of setting up their own meters to monitor dust. We plan to have these meters operating by December 2018 and it is expected that we will provide current data to the public via a website ‘dashboard’ . This is in line with Environment Canterbury’s new measures requiring boundary monitoring of all Yaldhurst quarries, following concerns over nuisance dust from the Yaldhurst report released on 22 June 2018.
Any of the Respirable Crystalline Silica levels noted in this report, were recorded to be below the accepted guidelines. There were 12 nuisance triggers of PM10 (nuisance dust). Hence the occurrence of dust is an environmental issue, not a health one.
Fulton Hogan will continue to monitor its air quality results in line with its work place health and safety responsibilities. Air monitoring, to improve site management practices and dust mitigation practices, was initiated in April 2017.
How will Fulton Hogan mitigate dust?
Dust is generated from three places within quarries: open areas and stock piles, traffic, and crushing processes.
To suppress this dust generation, we will continue to seal the main haul roads and use regular sweeping. Foggers will be used as they have been proven to be effective at controlling dust from crushers. The most difficult areas to control dust are the from plant and stock piles where alluvial gravel is exposed. Part of this reduction will include reducing open areas, and adjusting practice to grass and rehabilitate quarries as soon as possible after gravel is extracted. This will require Fulton Hogan to balance the time exposed with waiting for clean fill and how far below ground the surface is to be grassed.
We also propose to install an automated dust suppression system which can operate 24/7 and be triggered outside work hours. This system is similar to that used in ski fields for snow making and is being used overseas for dust control in quarries in urban areas.