Posted on Mar 3, 2017
North Calgary Quarry Update March 2017
North Calgary Gravely Quarry Update #2
Since the community discussion on February 4th regarding the North Calgary Gravel Quarry in the Transportation Utility Corridor (TUC) near West Springs and Wentworth, MLA Deborah Drever and her team have been collecting the concerns of the community regarding dust and noise mitigation, health and safety and more specifically the presence of respiratory crystalline silica dust.
We would like to thank those members of the community who wrote in to the constituency office to share their questions, comments and concerns regarding this project.
Alberta Transportation is committed to working closely with KGL, the project contractor to be the best neighbours that they can be for the life of this four year project.
- In response to the concerns of truck traffic on 101st Street, KGL has worked to develop a two-way haul road that will allow trucks to travel in both directions from the gravel quarry to Highway 8 – bypassing 101st Street altogether
- In response to the concerns regarding the location and size of the sound barrier that the contractor will be building to deflect noise and dust from the gravel pit away from your homes, Alberta Transportation has worked with KGL to move the barrier west and has raised the height to 4 metres.
- The back-up alarms on the KGL hauling trucks have been modified to reduce the amount of noise they make as this was a concern for the community as well.
- Concerns were raised regarding the work site lighting and its impact on neighboring homes. KGL has agreed to set up site lighting away from the community and will only be used during working hours. Alberta Transportation is committed to making sure this happens.
Finally, in response to the most pressing concern regarding respiratory crystalline silica dust, Alberta Transportation will be requiring the contractor (KGL) to perform air quality testing over the duration of the mining and crushing operations at this particular site (this is not typically a requirement for non-commercial gravel pits as directed by the legislated provincial guidelines).
Air quality monitors will be set up along the property line and they will monitor air quality, dust and fine particulate matter to ensure they remain within Alberta Occupational Health and Safety Code regulations.
More about crystalline silica dust and the community:
According to the Alberta Occupational Health and Safety Code, the occupational exposure limit for workers is 25 microns per cubic metre of air over an eight-hour period. For perspective, the American Occupational Health and Safety Association’s occupational exposure limit is double Alberta’s at 50 microns per cubic metre of air over an eight-hour period.
Outside of the workplace, exposure via ambient air to a high enough concentration of fine particulate silica at a long enough duration sufficient to pose a health risk is considered extremely uncommon. Health Canada has no guidelines around exposure to non-occupational silica dust exposure as a result.
A 2013 Health Canada study conducted in conjunction with Environment Canada concluded that fine particulates like silica “are not entering the environment in a quantity or concentration or under conditions that, for the general population in Canada, constitute or may constitute a danger to human life or health”.
There is no guideline in Alberta or through Health Canada for non-occupational, ambient exposure. For the purposes of this site, and in response to the concerns raised by the community, Alberta will be adopting Ontario’s guideline – a non-occupational exposure limit of 5 microns per cubic metre of air over a 24-hour period. This limit is lower than that of the occupational limit because it errs on the side of protecting more vulnerable segments of society like children and senior citizens and assumes 24 hour exposure.
It is important to acknowledge that there are a number of established mining and crushing operations in Calgary area using the same dust suppression methods that have been described by the province and KGL at community discussions that maintain air quality and fine particulate levels well within the legislated limits.
Mining and crushing operations for road construction create different sizes of gravel needed for road base, gravel fill and asphalt:
Less than 15 per cent of the gravel mined at the North Calgary Gravel Quarry will be smaller than 80 microns. An even smaller percentage will be 10 microns or less. Fine particulate crystalline silica smaller than 10 microns (0.01 millimeters) can be inhaled by humans and poses a potential health risk. Most importantly, only a fraction of this fraction will be silica dust.
As a main source of fine particulate dust, the crusher and transfer points will be equipped with spray bars to keep the gravel wet during the crushing and screening process and water will be used to control dust on stockpiles and the haul road. The Berm and stockpiles will be hydro-seeded to further protect from erosion and subsequent dust. The construction of the berm (four metres high by 20 metres wide and nearly 800 metres long) should obstruct wind near the ground and will help prevent dust from blowing into the west springs community.
Alberta Transportation has assured MLA Drever that they will continue to oversee this project closely, to ensure that KGL adheres to all guidelines and requirements, including air quality, set work hours, and dust and noise mitigation.
Extraction and on-site crushing is scheduled to begin sometime this month (March 2017).
MLA Drever will continue to advocate for the needs of the community as they relate to this project and beyond. Thanks to your letters and emails to the constituency office, Alberta Transportation is currently working with KGL to look into the possibility of planting trees near the sound mitigation berm that KGL will be creating.
The Calgary Bow Constituency Office:
6307 Bowness Road NW
Calgary, Alberta T3B 0E4