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Blasting & Fly Rock

The report submitted with the application indicates eight available blasting monitoring points but only three of these points show up in the blasting reports. Where and what is the data from the five non-reported monitoring points? Nelson Aggregate must provide a full and transparent reporting of the blasting records. Additionally, which blasting standards are being used by Nelson Aggregate? Are they meeting the current regulatory standards?

Data from 2014 shows 3 monitors:

  •  Data for each blast only included results from 3 of 6 available monitoring stations noted in the report.

  • Depending on the monitoring point, as many as 20% of all blasts showed an overpressure exceedance. 

  • As much as 40% of blast data for a specific monitoring point, showed no data which would indicate incomplete control monitoring of the blast and an inability to confirm the blast met the regulatory requirements.

  • The last 5 months of 2014, showed a material increase in overpressure exceedances and/or missing data.

  • There are multiple examples of blasts exceeding regulated limits at one of more monitoring points, followed by missing data for subsequent blasts. When a blasting result shows an exceedance, one would expect a prudent operator to adjust their blast designs and closely monitor subsequent blasts to confirm the problem has been corrected - the missing data in subsequent blasts is an inadequate follow-up to a non-compliant result.  

  • The proposed application indicates blasting in the vicinity of the high pressure petroleum products pipeline will be monitored and corrections to the blasting plan will be made as required to ensure compliance with safety requirements.  The compliance and monitoring results from 2014 do not appear to provide the safety measures required to prevent a catastrophic pipeline failure from a non-compliant blast.

  • Regarding the monitoring equipment: is it accurate, calibrated regularly and properly, and placed correctly in the appropriate locations?  How will Nelson respond to anomalies?

  • The increase in production associated with the increased mining operations means more blasting.

  • The lack of clarity in the report from the existing quarry does not encourage confidence that Nelson will keep within regulatory blasting limits and impacts.


Fly-rock is a phenomenon associated with blasting where natural variations in the rock formation can lead to unpredictable results, including launching significant and dangerous fragments of rock hundred or thousands of meters from the blast site. The US Bureau of Mines recommends a 500m blasting setback to protect from the risks of fly-rock. The Nelson Aggregate blast report is based on an Australian model, however, and does not use the model’s 4x multiplier to create a safety buffer. There needs to be enough blasting safety distance to prevent injuries and damages on adjacent properties and roads.  Will Nelson need to shutdown Cedar Springs Road every time they blast?

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