MARCH 2022

Keeping it fresh!

Canvas vent bags carry fresh air to all areas of Fosterville's underground workings.

A continuous supply of fresh air in an underground mine is critical for the health and safety of underground workers.

Fresh air enters Fosterville’s underground mine via declines, shafts and mine access points, and is distributed through the mine by fans and regulators. The surface mounted primary fans then draw the air back out the mine through upcast shafts.

Mine ventilation is important for several reasons including:

  • Maintaining adequate air supply for safe and healthy working conditions
  • To dilute and exhaust heat from underground plant and equipment and natural radiant heat from the ground at depth
  • To dilute exhaust emissions from underground plant and equipment, blasting gasses and naturally occurring native gasses.

Air quality monitoring

To ensure we maintain a safe environment for our people working underground we implement a comprehensive air quality monitoring program.

Exposure standards for underground air quality are established under the Occupational Health and Safety Act and associated regulations. FGM conducts monitoring of underground air quality, which includes Carbon Monoxide and Nitrogen Dioxide testing. Targeted personal monitoring for Inhalable and Respirable Particulate, Crystalline Silica and Diesel Particulate Material also forms part of our workplace occupational exposure monitoring program.

Continuous underground monitoring is completed at a series of fixed monitoring stations, which capture real-time continuous data on specific atmospheric parameters.

In addition, volumetric flow and more extensive atmospheric monitoring is completed routinely, which includes thermal working limit assessments.

Ventilation system monitoring

Air exhausted at the surface mounted primary fans during operating hours is similar in quality to the air that our underground workers breathe. It is vitally important to ensure the air is both safe for inhalation and does not present a risk to the environment. Fosterville Gold Mine maintains an extensive air quality monitoring program, which includes monitoring at point sources and neighbouring properties surrounding the operation. As part of this air quality monitoring program, FGM conducts routine emissions testing at the primary surface ventilation system.

The air quality of the vent system is monitored for various parameters including but not limited to:

  • Volatile Organic Compounds (VOCs)
  • Particulate Matter (dust including PM10 and PM2.5)
  • Carbon Monoxide
  • Diesel Particulate Matter (DPM)
  • Odour

The indicators and objectives for ambient air quality are based on the National Environment Protection Ambient Air Quality Measure (NEPM AAQ). Since air emissions disperse in the atmosphere, air quality guidelines are designed to be applied at receptor, rather than source.

The indicators and objectives for ambient air quality are based on the Air Quality Assessment Criteria (AQAC). As the measurements are taken at source (before dispersion occurs), this is where emission concentrations are highest. Monitoring at source shows several air quality indicators, including carbon monoxide, sulphur dioxide, lead, PM10, and PM2.5, are below the laboratory limits of detection.

These assessments ensure that emissions exiting the ventilation system are monitored and comply with relevant air quality guidelines. Achieving the air quality guidelines maintains the health and well-being of our people, neighbouring communities, and the protection of local ecosystems and biodiversity.