| FAILURE MODES AND EFFECTS ANALYSIS (FMEA) WORKSHEET - SAMPLE
MINE (POST CLOSURE) |
|
| PLAN / AREA |
ID |
FAILURE MODE |
EFFECTS |
PROJECT STAGE |
LIKELIHOOD |
CONSEQUENCES |
LEVEL OF CONFIDENCE |
HIGH CONCERN ISSUE |
MITIGATION/ COMMENTS |
|
| BIOLOGICAL IMPACTS & LAND USE |
REGULATORY
IMPACTS & CONCERNS |
PUBLIC CONCERN
& IMAGE |
HEALTH &
SAFETY |
|
| TAILINGS
DAM |
|
Physical Stability |
|
|
|
|
|
|
|
|
|
|
|
| |
A1 |
| Deep seated failure due to drainage pipe
failure (not plugged by concrete) |
|
Embankment
sloughing or non breaching failutre - no fatalities |
PC |
H |
L |
L |
M |
L |
H |
|
Concrete plug
drainage pipe. |
|
| |
A2.1 |
Deep seated and
or piping failure due to any reason including liner degradation and eventual
failure (drain plugged with concrete) |
Embankment
sloughing and breaching failutre - possible fatalities |
PC |
L |
M |
H |
H |
H |
M |
|
Liner expected
to deteriorate slowly with numrous small leaks allowing draindown of
impoundment without high phreatic surface in dam |
|
| |
A2.2 |
|
Embankment
sloughing and non-breaching failutre - no fatalities |
PC |
L |
L |
L |
M |
L |
M |
|
|
|
| |
A3.1 |
Diversion failure; pond flooding; dam
overtopping |
Breach of dam
and discharge - possible fatalities (assuming PMF capacity in dam) |
PC |
NL |
M |
H |
H |
H |
|
|
Must check dam
capacity to store PMF |
|
| |
A3.2 |
|
Breach of dam
and discharge - possible fatalities (assuming PMF cannot be stored in dam) |
PC |
H |
M |
H |
H |
H |
|
H |
Must check dam
capacity to store PMF; Need to upgrade the diversion or raise dam and upgrade
spillway to avoid failure |
|
| |
A4 |
Face Erosion;
deep gullys; leading to dam sloughing |
Sample mine
liable for repairs |
PC |
E |
L |
M |
M |
N |
H |
H |
Requires
long-term minor but regular maintenance.
Waste rock cover reduces erosion potential. Crest berm reduces
erosion. |
|
| |
A5 |
As above but with failure of
custodial care |
Gullies not
repaired leading to massive gully causing dam breach - no fatalities |
PC |
L |
M |
L |
L |
L |
|
|
Assumes that
new custodian will be told by sample mine of maintenance needs and new owner
undertakes responsibility for such. |
|
| |
A6 |
Diversion
spillway erosion |
Breach and discharge of tailings - no fatalities |
PC |
L |
L |
M |
M |
N |
H |
|
Upgrade ditch
to take 1:1000 year flood. Assumes that a concrete shute spillway will be
constructed. |
|
| |
|
Chemical Stability |
|
|
|
|
|
|
|
|
|
|
|
| |
A7 |
Salt
leaching - pond becomes toxic to livestock (with and without oxidation) |
Sick animals - Sample mine sued |
PC |
E |
M |
H |
H |
L |
H |
H |
Increased
tailings cover placement over uncovered and thin areas; Investigate oxidation and leaching
potential of tailings. |
|
| |
A8 |
As above but
with cover extended over entire back area |
Sick animals - Sample mine sued |
PC |
L |
M |
H |
H |
L |
H |
|
|
|
| |
A9 |
Surface water does
not meet regulatory standards |
Fails
regulatory standards |
PC |
E |
L |
L |
L |
N |
H |
|
Current results
have been reviewed by regulatory authorities. Check why regulatory authorities have not expressed concern |
|
| |
A10 |
Salt leaching - toxic to plants |
Loss of vegatation quality |
PC |
E |
L |
N |
N |
N |
H |
|
|
|
| |
A11 |
Ground water drainage quality
inadequate |
Fails
regulatory standards |
PC |
E |
H |
H |
M |
L |
M |
H |
Check why,
review monitoring results. Regulatory authorities have not expressed concern |
|
| |
|
Land Use |
|
|
|
|
|
|
|
|
|
|
|
| |
A12 |
Pond flooding |
Periodic
vegetation loss during flooding but good wetland vegetation development. |
PC |
E |
L |
L |
L |
N |
H |
|
|
| |
|
|
|
|
|
|
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|
|
|
|
| SPENT
ORE PILES |
|
Physical Stability |
|
|
|
|
|
|
|
|
|
|
| |
B1 |
Deep seated slope failure |
|
PC |
NL |
L |
M |
M |
N |
H |
|
|
| |
B2 |
Erosion and deep gullying |
|
PC |
E |
M |
H |
H |
N |
H |
H |
Spent ore
highly susceptable to erosion. Mitigation: Place 0.5 m waste rock
cover |
| |
|
Chemical Stability |
|
|
|
|
|
|
|
|
|
|
| |
B3 |
Surface water does
not meet regulatory standards |
|
PC |
E |
L |
L |
L |
L |
M |
|
Current results
have been reviewed by regulatory authorities. Check why regulatory authorities have not expressed concern |
| |
B4 |
Ground water does
not meet regulatory standards |
|
PC |
E |
L |
L |
L |
N |
M |
|
As above |
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
B5 |
Failure to meet land-use vegetation
objectives |
High erosion
rates prevent effective vegetation growth |
PC |
E |
M |
H |
H |
N |
H |
H |
Spent ore
highly susceptable to erosion. Mitigation: Place 0.5 m waste rock
cover plus 10 cm growth layer. |
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
| OPEN
PITS |
|
Physical Stability |
|
|
|
|
|
|
|
|
|
|
|
| |
C1 |
Deep seated slope failure |
Deep pits with
steep side slopes only |
PC |
M |
L |
L |
L |
N |
H |
|
Deep pits with steep side slopes only |
|
| |
C2 |
Erosion and deep gullying |
|
PC |
M |
L |
L |
L |
N |
H |
|
|
|
| |
|
Chemical Stability |
|
|
|
|
|
|
|
|
|
|
|
| |
C3 |
Surface water does
not meet regulatory standards |
Potential for
salt concentration increase due to inward drainage and evaporation
concentration. |
PC |
E |
H |
H |
H |
N |
L |
H |
Current results
have been reviewed by regulatory authorities. Check why regulatory authorities have not expressed
concern. Mitigation: Monitor and check for
salt concentration increases. |
|
| |
C4 |
Ground water does
not meet regulatory standards |
|
PC |
E |
L |
L |
L |
N |
M |
|
As above |
|
| |
|
Land Use |
|
|
|
|
|
|
|
|
|
|
|
| |
C5 |
Failure to meet land-use vegetation
objectives |
|
PC |
M |
L |
H |
H |
N |
L |
|
Landowner expects U shaped valley |
|
| |
|
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|
|
| WASTE
DUMPS |
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
D1 |
Deep seated slope failure |
|
PC |
NL |
L |
M |
M |
N |
H |
|
|
|
| |
D2 |
Erosion and deep gullying |
|
PC |
L |
L |
M |
M |
N |
H |
|
|
|
| |
|
Chemical Stability |
|
|
|
|
|
|
|
|
|
|
|
| |
D3 |
Surface water does
not meet regulatory standards |
|
PC |
E |
L |
L |
L |
N |
M |
|
Current results
have been reviewed by regulatory authorities. Check why regulatory authorities have not expressed concern |
|
| |
D4 |
Ground water does
not meet regulatory standards |
|
PC |
E |
L |
L |
L |
N |
M |
|
As above |
|
| |
|
Land Use |
|
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|
| |
D5 |
Failure to meet land-use vegetation
objectives |
|
PC |
L |
L |
L |
L |
N |
H |
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