How long must blasting records be kept at a mining site?

The requirement to keep blasting records at a mining site for three years is based on safety regulations and industry best practices. Maintaining these records for this duration helps ensure compliance with environmental and safety standards, offering a historic record that can be valuable for audits, inspections, and investigations concerning blasting operations.

These records can include details about the types of explosives used, the quantities, the timing of blasts, and results from monitoring blast impacts. Keeping them for three years allows regulators and stakeholders to review procedures and ensure that practices adhere to established safety protocols. This time frame is also robust enough to identify any recurring issues or patterns that may indicate a need for operational adjustments.

The other time frames presented are either too short or not aligned with the typical regulations governing mining operations, which is why they are not the correct answer.