❓ A WA parliamentary question on notice addresses concerns about groundwater contamination and potential dam failure at KCGM's Fimiston tailings dams, seeking clarification on licensing conditions and preventative measures. The Minister's response acknowledges seepage but asserts licensing aims to prevent freshwater contamination and that dam design mitigates failure risk.
AnsweredQoN 2890Legislative Council
QuestionView source ↗
I refer to the Thompson and Brett Report dated October 12 2004, concerning the Fimiston I and Fimiston 2 tailings dams operated by Kalgoorlie Consolidated Gold Mines (KCGM) owned by Barrick Gold and Newmont Ltd -
(1) Can the Minister confirm that the report in part states ‘Groundwater flow is clearly leaving Fimiston I and flowing out both to the east and north. The easterly flow concentrates in a narrow flow band through the western side of Optimum Resources lease. This flow is now clearly influenced by KCGM’s extraction borefield in this area. Similar flow lines could be drawn for Fimiston II and the area south east of the Fimiston mill where the Oroya TSF is currently covered with waste rock The shape of the flow lines and groundwater contours suggest that the seepage mound from the Fimiston I is influencing groundwater levels at least 2 km from the dam wall and that a similar mound is developing under Fimiston II. The groundwater contours also suggest that there is still a residual groundwater mound under the decommissioned Oroya TSF’?
(2) Did the Department of Environment (DoE) licence the Fimiston II tailings dam when it was first commissioned to have seepage extending up to 2 km or greater from the dam walls causing pollution killing/stressing vegetation for over 10 years and more?
(3) If yes to (2), why not?
(4) Did the Department of Environment (DoE) licence both the Fimiston I and Fimiston II Tailings dams when they were both first commissioned at the respective dates to have seepage of cyanide, alkaline and saline water along with heavy metals contaminating fresh water dams such as the Neaves and Fioris properties that people used for stock and residential purposes when they lived on in the area?
(5) If no to (5), why not?
(6) If yes to (5), why?
(7) Did the Report dated October 12 2004 state ‘that if a dam break was to occur there would be potential for release of tailings with flow covering the AN Railway line. Such a failure could also impact on the Parkeston power station, the Liquichem chemical plant and Readymix concrete plant, now located in the vicinity. The study predicted that failure would result in a flow width of up to 900 m moving at 10-15m/sec lasting 10 -30 minutes’?
(8) If no to (8), what did it state?
(9) Will the Department of Environment write and direct KCGM to immediately install large high surface barriers to prevent any waste from the Fimiston I tailings dam, in the event of dam break failure from flowing onto Prospecting Licence 26/3126 affecting the environment and any persons on that tenement given that it is located approximately 60 metres from the bottom toe of the Fimiston I tailings dam?
(10) If no to (9), why not?
(1) Can the Minister confirm that the report in part states ‘Groundwater flow is clearly leaving Fimiston I and flowing out both to the east and north. The easterly flow concentrates in a narrow flow band through the western side of Optimum Resources lease. This flow is now clearly influenced by KCGM’s extraction borefield in this area. Similar flow lines could be drawn for Fimiston II and the area south east of the Fimiston mill where the Oroya TSF is currently covered with waste rock The shape of the flow lines and groundwater contours suggest that the seepage mound from the Fimiston I is influencing groundwater levels at least 2 km from the dam wall and that a similar mound is developing under Fimiston II. The groundwater contours also suggest that there is still a residual groundwater mound under the decommissioned Oroya TSF’?
(2) Did the Department of Environment (DoE) licence the Fimiston II tailings dam when it was first commissioned to have seepage extending up to 2 km or greater from the dam walls causing pollution killing/stressing vegetation for over 10 years and more?
(3) If yes to (2), why not?
(4) Did the Department of Environment (DoE) licence both the Fimiston I and Fimiston II Tailings dams when they were both first commissioned at the respective dates to have seepage of cyanide, alkaline and saline water along with heavy metals contaminating fresh water dams such as the Neaves and Fioris properties that people used for stock and residential purposes when they lived on in the area?
(5) If no to (5), why not?
(6) If yes to (5), why?
(7) Did the Report dated October 12 2004 state ‘that if a dam break was to occur there would be potential for release of tailings with flow covering the AN Railway line. Such a failure could also impact on the Parkeston power station, the Liquichem chemical plant and Readymix concrete plant, now located in the vicinity. The study predicted that failure would result in a flow width of up to 900 m moving at 10-15m/sec lasting 10 -30 minutes’?
(8) If no to (8), what did it state?
(9) Will the Department of Environment write and direct KCGM to immediately install large high surface barriers to prevent any waste from the Fimiston I tailings dam, in the event of dam break failure from flowing onto Prospecting Licence 26/3126 affecting the environment and any persons on that tenement given that it is located approximately 60 metres from the bottom toe of the Fimiston I tailings dam?
(10) If no to (9), why not?
AnswerView source ↗
Answered
14 March 2006
Responded by
Minister for Education and Training representing the Minister for the Environment
Response time
124 days
The Minister for the Environment; Science has provided the following response: The following information is correct as at 16 January 2006. (1) Yes. (2) Early licences relating to KCGM's Fimiston operations contain the following condition, " All matter containing saline, alkaline or cyanide constituents shall be retained within impervious holding facilities, such that there is no discernible impairment of surface or underground waters ". KCGM's most recent licence states that, " The licensee shall manage the storage of all matter containing cyanide, saline or alkaline constituents within holding facilities in a manner, which prevents pollution ." (3) Not applicable. (4) See answer to question (2). It is clear that the licence conditions on the early licence and most recent licence are to prevent the contamination of fresh water resources. Given the naturally occurring groundwater is saline the groundwater would not be able to support fresh water supplies. Therefore any fresh water dams in the area must be relying on surface water. Consequently seepage from KCGMs Tailings Storage Facilities is unlikely to impact on this supply, providing groundwater levels are controlled. (5-6) Not applicable. (7) Yes. (8) Not applicable. (9) No. (10) As recommended in the Thompson and Brett Report the Fimiston I tailings dam has been designed to meet the relevant (risk assessment) guidelines established by the Australian National Committee on Large Dams (ANCOLD). The design is based on conservative assumptions for critical factors, including a 1 in 1 000 000 annual exceedance probability (AEP) rain event and the maximum credible earthquake (MCE), that could influence failure. Due to the conservative assumptions made in the design the risk of dam failure is negligible and no barrier is considered necessary downstream of the Fimiston I dam.
The following information is correct as at 16 January 2006. (1) Yes. (2) Early licences relating to KCGM's Fimiston operations contain the following condition, " All matter containing saline, alkaline or cyanide constituents shall be retained within impervious holding facilities, such that there is no discernible impairment of surface or underground waters ". KCGM's most recent licence states that, " The licensee shall manage the storage of all matter containing cyanide, saline or alkaline constituents within holding facilities in a manner, which prevents pollution ." (3) Not applicable. (4) See answer to question (2). It is clear that the licence conditions on the early licence and most recent licence are to prevent the contamination of fresh water resources. Given the naturally occurring groundwater is saline the groundwater would not be able to support fresh water supplies. Therefore any fresh water dams in the area must be relying on surface water. Consequently seepage from KCGMs Tailings Storage Facilities is unlikely to impact on this supply, providing groundwater levels are controlled. (5-6) Not applicable. (7) Yes. (8) Not applicable. (9) No. (10) As recommended in the Thompson and Brett Report the Fimiston I tailings dam has been designed to meet the relevant (risk assessment) guidelines established by the Australian National Committee on Large Dams (ANCOLD). The design is based on conservative assumptions for critical factors, including a 1 in 1 000 000 annual exceedance probability (AEP) rain event and the maximum credible earthquake (MCE), that could influence failure. Due to the conservative assumptions made in the design the risk of dam failure is negligible and no barrier is considered necessary downstream of the Fimiston I dam.
(1) Yes. (2) Early licences relating to KCGM's Fimiston operations contain the following condition, " All matter containing saline, alkaline or cyanide constituents shall be retained within impervious holding facilities, such that there is no discernible impairment of surface or underground waters ". KCGM's most recent licence states that, " The licensee shall manage the storage of all matter containing cyanide, saline or alkaline constituents within holding facilities in a manner, which prevents pollution ." (3) Not applicable. (4) See answer to question (2). It is clear that the licence conditions on the early licence and most recent licence are to prevent the contamination of fresh water resources. Given the naturally occurring groundwater is saline the groundwater would not be able to support fresh water supplies. Therefore any fresh water dams in the area must be relying on surface water. Consequently seepage from KCGMs Tailings Storage Facilities is unlikely to impact on this supply, providing groundwater levels are controlled. (5-6) Not applicable. (7) Yes. (8) Not applicable. (9) No. (10) As recommended in the Thompson and Brett Report the Fimiston I tailings dam has been designed to meet the relevant (risk assessment) guidelines established by the Australian National Committee on Large Dams (ANCOLD). The design is based on conservative assumptions for critical factors, including a 1 in 1 000 000 annual exceedance probability (AEP) rain event and the maximum credible earthquake (MCE), that could influence failure. Due to the conservative assumptions made in the design the risk of dam failure is negligible and no barrier is considered necessary downstream of the Fimiston I dam.
(2) Early licences relating to KCGM's Fimiston operations contain the following condition, " All matter containing saline, alkaline or cyanide constituents shall be retained within impervious holding facilities, such that there is no discernible impairment of surface or underground waters ". KCGM's most recent licence states that, " The licensee shall manage the storage of all matter containing cyanide, saline or alkaline constituents within holding facilities in a manner, which prevents pollution ." (3) Not applicable. (4) See answer to question (2). It is clear that the licence conditions on the early licence and most recent licence are to prevent the contamination of fresh water resources. Given the naturally occurring groundwater is saline the groundwater would not be able to support fresh water supplies. Therefore any fresh water dams in the area must be relying on surface water. Consequently seepage from KCGMs Tailings Storage Facilities is unlikely to impact on this supply, providing groundwater levels are controlled. (5-6) Not applicable. (7) Yes. (8) Not applicable. (9) No. (10) As recommended in the Thompson and Brett Report the Fimiston I tailings dam has been designed to meet the relevant (risk assessment) guidelines established by the Australian National Committee on Large Dams (ANCOLD). The design is based on conservative assumptions for critical factors, including a 1 in 1 000 000 annual exceedance probability (AEP) rain event and the maximum credible earthquake (MCE), that could influence failure. Due to the conservative assumptions made in the design the risk of dam failure is negligible and no barrier is considered necessary downstream of the Fimiston I dam.
(3) Not applicable. (4) See answer to question (2). It is clear that the licence conditions on the early licence and most recent licence are to prevent the contamination of fresh water resources. Given the naturally occurring groundwater is saline the groundwater would not be able to support fresh water supplies. Therefore any fresh water dams in the area must be relying on surface water. Consequently seepage from KCGMs Tailings Storage Facilities is unlikely to impact on this supply, providing groundwater levels are controlled. (5-6) Not applicable. (7) Yes. (8) Not applicable. (9) No. (10) As recommended in the Thompson and Brett Report the Fimiston I tailings dam has been designed to meet the relevant (risk assessment) guidelines established by the Australian National Committee on Large Dams (ANCOLD). The design is based on conservative assumptions for critical factors, including a 1 in 1 000 000 annual exceedance probability (AEP) rain event and the maximum credible earthquake (MCE), that could influence failure. Due to the conservative assumptions made in the design the risk of dam failure is negligible and no barrier is considered necessary downstream of the Fimiston I dam.
(4) See answer to question (2). It is clear that the licence conditions on the early licence and most recent licence are to prevent the contamination of fresh water resources. Given the naturally occurring groundwater is saline the groundwater would not be able to support fresh water supplies. Therefore any fresh water dams in the area must be relying on surface water. Consequently seepage from KCGMs Tailings Storage Facilities is unlikely to impact on this supply, providing groundwater levels are controlled. (5-6) Not applicable. (7) Yes. (8) Not applicable. (9) No. (10) As recommended in the Thompson and Brett Report the Fimiston I tailings dam has been designed to meet the relevant (risk assessment) guidelines established by the Australian National Committee on Large Dams (ANCOLD). The design is based on conservative assumptions for critical factors, including a 1 in 1 000 000 annual exceedance probability (AEP) rain event and the maximum credible earthquake (MCE), that could influence failure. Due to the conservative assumptions made in the design the risk of dam failure is negligible and no barrier is considered necessary downstream of the Fimiston I dam.
(5-6) Not applicable. (7) Yes. (8) Not applicable. (9) No. (10) As recommended in the Thompson and Brett Report the Fimiston I tailings dam has been designed to meet the relevant (risk assessment) guidelines established by the Australian National Committee on Large Dams (ANCOLD). The design is based on conservative assumptions for critical factors, including a 1 in 1 000 000 annual exceedance probability (AEP) rain event and the maximum credible earthquake (MCE), that could influence failure. Due to the conservative assumptions made in the design the risk of dam failure is negligible and no barrier is considered necessary downstream of the Fimiston I dam.
(7) Yes. (8) Not applicable. (9) No. (10) As recommended in the Thompson and Brett Report the Fimiston I tailings dam has been designed to meet the relevant (risk assessment) guidelines established by the Australian National Committee on Large Dams (ANCOLD). The design is based on conservative assumptions for critical factors, including a 1 in 1 000 000 annual exceedance probability (AEP) rain event and the maximum credible earthquake (MCE), that could influence failure. Due to the conservative assumptions made in the design the risk of dam failure is negligible and no barrier is considered necessary downstream of the Fimiston I dam.
(8) Not applicable. (9) No. (10) As recommended in the Thompson and Brett Report the Fimiston I tailings dam has been designed to meet the relevant (risk assessment) guidelines established by the Australian National Committee on Large Dams (ANCOLD). The design is based on conservative assumptions for critical factors, including a 1 in 1 000 000 annual exceedance probability (AEP) rain event and the maximum credible earthquake (MCE), that could influence failure. Due to the conservative assumptions made in the design the risk of dam failure is negligible and no barrier is considered necessary downstream of the Fimiston I dam.
(9) No. (10) As recommended in the Thompson and Brett Report the Fimiston I tailings dam has been designed to meet the relevant (risk assessment) guidelines established by the Australian National Committee on Large Dams (ANCOLD). The design is based on conservative assumptions for critical factors, including a 1 in 1 000 000 annual exceedance probability (AEP) rain event and the maximum credible earthquake (MCE), that could influence failure. Due to the conservative assumptions made in the design the risk of dam failure is negligible and no barrier is considered necessary downstream of the Fimiston I dam.
(10) As recommended in the Thompson and Brett Report the Fimiston I tailings dam has been designed to meet the relevant (risk assessment) guidelines established by the Australian National Committee on Large Dams (ANCOLD). The design is based on conservative assumptions for critical factors, including a 1 in 1 000 000 annual exceedance probability (AEP) rain event and the maximum credible earthquake (MCE), that could influence failure. Due to the conservative assumptions made in the design the risk of dam failure is negligible and no barrier is considered necessary downstream of the Fimiston I dam.
The following information is correct as at 16 January 2006. (1) Yes. (2) Early licences relating to KCGM's Fimiston operations contain the following condition, " All matter containing saline, alkaline or cyanide constituents shall be retained within impervious holding facilities, such that there is no discernible impairment of surface or underground waters ". KCGM's most recent licence states that, " The licensee shall manage the storage of all matter containing cyanide, saline or alkaline constituents within holding facilities in a manner, which prevents pollution ." (3) Not applicable. (4) See answer to question (2). It is clear that the licence conditions on the early licence and most recent licence are to prevent the contamination of fresh water resources. Given the naturally occurring groundwater is saline the groundwater would not be able to support fresh water supplies. Therefore any fresh water dams in the area must be relying on surface water. Consequently seepage from KCGMs Tailings Storage Facilities is unlikely to impact on this supply, providing groundwater levels are controlled. (5-6) Not applicable. (7) Yes. (8) Not applicable. (9) No. (10) As recommended in the Thompson and Brett Report the Fimiston I tailings dam has been designed to meet the relevant (risk assessment) guidelines established by the Australian National Committee on Large Dams (ANCOLD). The design is based on conservative assumptions for critical factors, including a 1 in 1 000 000 annual exceedance probability (AEP) rain event and the maximum credible earthquake (MCE), that could influence failure. Due to the conservative assumptions made in the design the risk of dam failure is negligible and no barrier is considered necessary downstream of the Fimiston I dam.
(1) Yes. (2) Early licences relating to KCGM's Fimiston operations contain the following condition, " All matter containing saline, alkaline or cyanide constituents shall be retained within impervious holding facilities, such that there is no discernible impairment of surface or underground waters ". KCGM's most recent licence states that, " The licensee shall manage the storage of all matter containing cyanide, saline or alkaline constituents within holding facilities in a manner, which prevents pollution ." (3) Not applicable. (4) See answer to question (2). It is clear that the licence conditions on the early licence and most recent licence are to prevent the contamination of fresh water resources. Given the naturally occurring groundwater is saline the groundwater would not be able to support fresh water supplies. Therefore any fresh water dams in the area must be relying on surface water. Consequently seepage from KCGMs Tailings Storage Facilities is unlikely to impact on this supply, providing groundwater levels are controlled. (5-6) Not applicable. (7) Yes. (8) Not applicable. (9) No. (10) As recommended in the Thompson and Brett Report the Fimiston I tailings dam has been designed to meet the relevant (risk assessment) guidelines established by the Australian National Committee on Large Dams (ANCOLD). The design is based on conservative assumptions for critical factors, including a 1 in 1 000 000 annual exceedance probability (AEP) rain event and the maximum credible earthquake (MCE), that could influence failure. Due to the conservative assumptions made in the design the risk of dam failure is negligible and no barrier is considered necessary downstream of the Fimiston I dam.
(2) Early licences relating to KCGM's Fimiston operations contain the following condition, " All matter containing saline, alkaline or cyanide constituents shall be retained within impervious holding facilities, such that there is no discernible impairment of surface or underground waters ". KCGM's most recent licence states that, " The licensee shall manage the storage of all matter containing cyanide, saline or alkaline constituents within holding facilities in a manner, which prevents pollution ." (3) Not applicable. (4) See answer to question (2). It is clear that the licence conditions on the early licence and most recent licence are to prevent the contamination of fresh water resources. Given the naturally occurring groundwater is saline the groundwater would not be able to support fresh water supplies. Therefore any fresh water dams in the area must be relying on surface water. Consequently seepage from KCGMs Tailings Storage Facilities is unlikely to impact on this supply, providing groundwater levels are controlled. (5-6) Not applicable. (7) Yes. (8) Not applicable. (9) No. (10) As recommended in the Thompson and Brett Report the Fimiston I tailings dam has been designed to meet the relevant (risk assessment) guidelines established by the Australian National Committee on Large Dams (ANCOLD). The design is based on conservative assumptions for critical factors, including a 1 in 1 000 000 annual exceedance probability (AEP) rain event and the maximum credible earthquake (MCE), that could influence failure. Due to the conservative assumptions made in the design the risk of dam failure is negligible and no barrier is considered necessary downstream of the Fimiston I dam.
(3) Not applicable. (4) See answer to question (2). It is clear that the licence conditions on the early licence and most recent licence are to prevent the contamination of fresh water resources. Given the naturally occurring groundwater is saline the groundwater would not be able to support fresh water supplies. Therefore any fresh water dams in the area must be relying on surface water. Consequently seepage from KCGMs Tailings Storage Facilities is unlikely to impact on this supply, providing groundwater levels are controlled. (5-6) Not applicable. (7) Yes. (8) Not applicable. (9) No. (10) As recommended in the Thompson and Brett Report the Fimiston I tailings dam has been designed to meet the relevant (risk assessment) guidelines established by the Australian National Committee on Large Dams (ANCOLD). The design is based on conservative assumptions for critical factors, including a 1 in 1 000 000 annual exceedance probability (AEP) rain event and the maximum credible earthquake (MCE), that could influence failure. Due to the conservative assumptions made in the design the risk of dam failure is negligible and no barrier is considered necessary downstream of the Fimiston I dam.
(4) See answer to question (2). It is clear that the licence conditions on the early licence and most recent licence are to prevent the contamination of fresh water resources. Given the naturally occurring groundwater is saline the groundwater would not be able to support fresh water supplies. Therefore any fresh water dams in the area must be relying on surface water. Consequently seepage from KCGMs Tailings Storage Facilities is unlikely to impact on this supply, providing groundwater levels are controlled. (5-6) Not applicable. (7) Yes. (8) Not applicable. (9) No. (10) As recommended in the Thompson and Brett Report the Fimiston I tailings dam has been designed to meet the relevant (risk assessment) guidelines established by the Australian National Committee on Large Dams (ANCOLD). The design is based on conservative assumptions for critical factors, including a 1 in 1 000 000 annual exceedance probability (AEP) rain event and the maximum credible earthquake (MCE), that could influence failure. Due to the conservative assumptions made in the design the risk of dam failure is negligible and no barrier is considered necessary downstream of the Fimiston I dam.
(5-6) Not applicable. (7) Yes. (8) Not applicable. (9) No. (10) As recommended in the Thompson and Brett Report the Fimiston I tailings dam has been designed to meet the relevant (risk assessment) guidelines established by the Australian National Committee on Large Dams (ANCOLD). The design is based on conservative assumptions for critical factors, including a 1 in 1 000 000 annual exceedance probability (AEP) rain event and the maximum credible earthquake (MCE), that could influence failure. Due to the conservative assumptions made in the design the risk of dam failure is negligible and no barrier is considered necessary downstream of the Fimiston I dam.
(7) Yes. (8) Not applicable. (9) No. (10) As recommended in the Thompson and Brett Report the Fimiston I tailings dam has been designed to meet the relevant (risk assessment) guidelines established by the Australian National Committee on Large Dams (ANCOLD). The design is based on conservative assumptions for critical factors, including a 1 in 1 000 000 annual exceedance probability (AEP) rain event and the maximum credible earthquake (MCE), that could influence failure. Due to the conservative assumptions made in the design the risk of dam failure is negligible and no barrier is considered necessary downstream of the Fimiston I dam.
(8) Not applicable. (9) No. (10) As recommended in the Thompson and Brett Report the Fimiston I tailings dam has been designed to meet the relevant (risk assessment) guidelines established by the Australian National Committee on Large Dams (ANCOLD). The design is based on conservative assumptions for critical factors, including a 1 in 1 000 000 annual exceedance probability (AEP) rain event and the maximum credible earthquake (MCE), that could influence failure. Due to the conservative assumptions made in the design the risk of dam failure is negligible and no barrier is considered necessary downstream of the Fimiston I dam.
(9) No. (10) As recommended in the Thompson and Brett Report the Fimiston I tailings dam has been designed to meet the relevant (risk assessment) guidelines established by the Australian National Committee on Large Dams (ANCOLD). The design is based on conservative assumptions for critical factors, including a 1 in 1 000 000 annual exceedance probability (AEP) rain event and the maximum credible earthquake (MCE), that could influence failure. Due to the conservative assumptions made in the design the risk of dam failure is negligible and no barrier is considered necessary downstream of the Fimiston I dam.
(10) As recommended in the Thompson and Brett Report the Fimiston I tailings dam has been designed to meet the relevant (risk assessment) guidelines established by the Australian National Committee on Large Dams (ANCOLD). The design is based on conservative assumptions for critical factors, including a 1 in 1 000 000 annual exceedance probability (AEP) rain event and the maximum credible earthquake (MCE), that could influence failure. Due to the conservative assumptions made in the design the risk of dam failure is negligible and no barrier is considered necessary downstream of the Fimiston I dam.
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