Report - METEX - Inundation or inrush of substances - October 2024 to February 2026
This report provides the findings of an assessment program at underground metalliferous mines focussing on inundation or inrush of substances
| Sector | Metalliferous - underground |
|---|---|
| Principal hazard plan | Inundation or inrush of substances |
| Material unwanted event | Inundation or inrush of material or substances |
Operation type assessed
| Operation type | Number of mines assessed |
|---|---|
| Underground | 12 |
| Total | 12 |
Critical control and criteria assessed
| Critical control | Criteria |
|---|---|
| The mine is designed to geotechnical and hydrogeological conditions | How does the mine verify they are accurately executing design and updating design for identified hazards? |
| Reduce magnitude of the source | Do workers and supervisors understand how the site is reducing the magnitude of identified inundation and inrush sources? |
| Drill and Blast Management |
How do workers ensure that drilling and blasting is conducted safely with regards to inundation or inrush sources? |
| Water Management System | Does the mine water management system have capacity and redundancy for extreme events? |
| Containment system design and construction | How does the mine inspect and verify containment systems are installed and maintained as fit for purpose? |
| Workers are restricted / removed from high-risk areas | Do workers and supervisors understand the systems in place to restrict or remove people from high-risk areas, including inrush control zones and withdrawal conditions? |
| Flow Management (Exploratory drilling and stand pipes) | Has flow management been implemented as per design? |
| Backfill Management (hydraulic and paste) | Do workers understand and implement the backfill controls identified? |
Findings with issues identified - underground mines
| Critical control | Findings of concern | Findings of contravention | Findings of immediate risk | Total findings with issues |
|---|---|---|---|---|
| The mine is designed to geotechnical and hydrogeological conditions |
- |
1 |
1 |
2 |
| Reduce magnitude of the source |
2 |
2 |
1 |
5 |
| Drill and Blast Management |
1 |
1 |
1 |
3 |
| Water Management System |
1 |
3 |
2 |
6 |
| Containment system design and construction |
1 |
2 |
1 |
4 |
| Workers are restricted / removed from high-risk areas |
- |
3 |
1 |
4 |
| Flow Management (Exploratory drilling and stand pipes) |
- |
2 |
1 |
3 |
| Backfill Management (hydraulic and paste) |
- |
1 |
- |
1 |
| Total findings with issues |
5 |
15 |
8 |
28 |
Compliance notice type issues during the program
| Notice type | Notices |
Percentage of notices issued |
|---|---|---|
| WHS(MPS)A s23 notice of concerns |
10 |
25% |
| WHSA s191 improvement notice |
26 |
65% |
| WHSA s195 prohibition notice |
4 |
10% |
| Total |
40 |
100% |
Total of 40 compliance notices issued to 11 mines
Note: This data represents all notices issued during the program and may include notices other than inundation or inrush of substances topics.
Recommendations
Operators of underground metalliferous mines should review their site principal hazard inundation or inrush of substances plan and the findings of critical controls assessed by the Regulator for the topic of exposure to inundation or inrush of substances:
| Assessed critical controls | Recommendations to mine operators |
|---|---|
| The mine is designed to geotechnical and hydrogeological conditions |
|
| Reduce magnitude of the source | Inrush control zones (ICZs) TARPS are adequate to monitor and identify changed conditions in the magnitude of the source for any potential for inundation or inrush |
| Drill and Blast Management | Ensure all probe drilling operations have risk controls in place and in operation whilst drilling to control the potential for inrush and any subsequent emergency sealing of the borehole |
| Water Management System | Ensure adequate resources are available to monitor and rectify any non-conformances identified in change management to control likely inundation and inrush of substances |
| Containment system design and construction |
|
| Workers are restricted / removed from high-risk areas | Ensure supervisors and workers are provided with applicable information, instruction and training related to the site management of inundation or inrush of substances |
| Flow Management (Exploratory drilling and stand pipes) |
|
| Backfill Management (hydraulic and paste) |
|
References
Fact sheets
Safety Alert
September 2022 - Worker swims to shore after pontoon pump and boat sink (PDF, 360.73 KB)
January 2011 - Water inrush from Raisebore Hole (PDF, 95.32 KB)
NSW Resources published web resources