The Dust Complaint and the Dry Spell
It is July, and the site has had 18 dry days. The nearest village is 600 m downwind. The site's dust suppression bowser is broken and the replacement part is five days away. The mobile screen is running dry, and the stockpile area is generating visible plumes that drift towards the village. The environmental permit requires dust suppression on all haul roads and stockpiles during dry weather. A resident has already complained. The site manager suggests running only at night when 'no one can see it'.
1. Evaluate the site manager's suggestion and state your position.
Read the worked answer
Reject the suggestion. Running at night to avoid visibility:
- Does not reduce the emission - dust still travels to the village and settles on homes, gardens and watercourses.
- Breaches the permit, which requires suppression, not concealment.
- Is a deliberate evasion of an environmental control, which is a regulatory offence and would damage the site's relationship with the regulator and community.
- Ignores health effects - respirable crystalline silica is a carcinogen; night-time exposure still affects residents and workers.
My position: the site must comply with the permit. If suppression cannot be maintained, the dust-generating activities must be reduced or stopped until it can. I would record the manager's instruction and escalate it.
2. What interim controls can you put in place for the five days until the bowser is repaired?
Read the worked answer
- Reduce the dust-generating activities: stop the dry screening and restrict stockpile movement to essential tasks.
- Water via alternative means: use a water bowser hired in, a tractor-mounted tanker, or a fixed water line and hose reel.
- Damp down haul roads and stockpiles manually at intervals, with a written log of times and areas.
- Reduce drop heights from conveyors and loaders, and use dust curtains or sprays on the screen if fitted.
- Speed limits on haul roads to reduce re-entrainment.
- Monitor with visual checks and, if available, a dust gauge; record wind direction and any visible plume.
- Communicate with the resident: explain the interim measures and the repair date.
- Escalate the bowser repair as a priority purchase.
3. How would you handle the resident's complaint formally?
Read the worked answer
- Acknowledge promptly and record the complaint: date, time, nature, location, wind conditions.
- Investigate - check the dust log, wind data, and whether controls were in place at the time.
- Respond with what was found and what will change.
- Record the complaint in the site's complaints register, as the permit likely requires.
- Review whether the event is a permit breach requiring notification to the regulator.
- Follow up after the controls are in place to confirm the issue is resolved.
A complaint handled well protects the site's licence to operate; one ignored becomes a regulator's enforcement notice.