Mr POOLE - 2001-02-21
I refer to media reports that due to heavy rainfall a controlled release of water from the McArthur River Mines tailings run-off dam has become necessary. Can the minister advise the House how much water has been released, what contaminants it contains and what, if any, environmental damage can be expected?
ANSWER
Mr Speaker, quite an important question. I think all members are aware that the monsoon conditions that have been occurring in the McArthur River area, especially the effect of those successive cyclones, Winsome and Wylva, have resulted in the McArthur River area receiving more than double its average level of rainfall so far this wet season. Obviously, high flood levels have resulted, and the area around the McArthur River mine site is completely surrounded and has forced the company to cease its underground workings at the present time.
The heavy rainfall also caused an adjacent creek to breach a wall of the tailings return run-off water dam and flow into it. Last Friday, the mine operators sought and, after appropriate discussions and fact finding, were granted, by the Controller of Water Resources a licence to discharge excess water from that dam.
I think it is important to explain the facts, which may be at odds with some of the media reports on the situation. For a start, no tailings have been released, as has been reported by the local media - no tailings have been released. The controlled release of water is designed to protect the environmental integrity of the mine site. The tailings dam at McArthur River is divided into two compartments. Tailings are placed in one of the compartments, and the other compartment, known as the run-off pond, carries run-off from the tailings pond, plus rain water from its own catchment.
That system is designed to enable controlled release of water, which does not include tailings. So it is designed for that controlled release and that release does not include tailings, in the event of extreme flooding. That is a protected contingency, as outlined in the mine’s environmental impact statement, which was done in accordance with approved design and procedures. So, in other words, in the whole process of approvals and design, there is a process which enables controlled release from the run-off pond.
This is the first time that such a release has had to be approved for that McArthur River Mine, which obviously indicates the very unusual severity of the current flood conditions. Approximately 40 megalitres of water is being released every 24 hours. This represents just 1/1000th of the flow in the adjacent Barney Creek.
The water at the release point obviously contains elevated levels of lead and zinc, and they are both substances which do occur naturally in the McArthur River system. We have monitoring equipment set up 2000 m from the release point, downstream from the mine site, before the water enters the McArthur River. That monitoring equipment has found that lead levels are undetectable at that point, and that the zinc levels are within drinking water standards, that is before it even enters the river. There is no lead measurable and the zinc levels are at drinking level standards.
The licence to release water allows for a maximum of 1000 megalitres to be released, subject to ongoing monitoring. The water sampling, under the processes that are approved, must occur daily during the release period, and up to three days afterwards it is done daily, after the discharge has been ceased. It also has to then occur on a weekly basis until 30 April. So there is a process in place to continually monitor even when the water flows have been stopped.
I can assure honourable members that the approval to discharge water from any mine site into natural creeks or rivers certainly isn’t given lightly. The government is satisfied that it was essential in this case to prevent a potentially more serious situation if the dam had burst. But we are also satisfied the levels of contaminants discharged are well within acceptable limitations. There was certainly no threat to the environment, or to public health. I think that needs to be stressed. I have to say that the McArthur Rive Mine people always acted responsibly in regards to the environment, and this certainly is the case at the present time.
The Northern Territory Environment Centre, unfortunately, is not interested in the facts. They are obviously only interested in capitalising on the situation and to causing unnecessary alarm, and also denigrating the excellent environmental performance of the Northern Territory mining industry. I just say to the local media, in future, rather than reporting automatically claims by the Environment Centre, whose record unfortunately showed over the past that they have never been accurate or fully truthful with regards to the facts that they comment on, please make some inquiries to get the appropriate details so that there is not unnecessary alarm caused to the community by not reporting fully the facts but relying on the Environment Centre for that information.
In this situation, it is within the design parameters; it is within a process which received prior approval in the environmental impact processes; and the monitoring shows that there certainly is no detriment whatsoever to the environment.
ANSWER
Mr Speaker, quite an important question. I think all members are aware that the monsoon conditions that have been occurring in the McArthur River area, especially the effect of those successive cyclones, Winsome and Wylva, have resulted in the McArthur River area receiving more than double its average level of rainfall so far this wet season. Obviously, high flood levels have resulted, and the area around the McArthur River mine site is completely surrounded and has forced the company to cease its underground workings at the present time.
The heavy rainfall also caused an adjacent creek to breach a wall of the tailings return run-off water dam and flow into it. Last Friday, the mine operators sought and, after appropriate discussions and fact finding, were granted, by the Controller of Water Resources a licence to discharge excess water from that dam.
I think it is important to explain the facts, which may be at odds with some of the media reports on the situation. For a start, no tailings have been released, as has been reported by the local media - no tailings have been released. The controlled release of water is designed to protect the environmental integrity of the mine site. The tailings dam at McArthur River is divided into two compartments. Tailings are placed in one of the compartments, and the other compartment, known as the run-off pond, carries run-off from the tailings pond, plus rain water from its own catchment.
That system is designed to enable controlled release of water, which does not include tailings. So it is designed for that controlled release and that release does not include tailings, in the event of extreme flooding. That is a protected contingency, as outlined in the mine’s environmental impact statement, which was done in accordance with approved design and procedures. So, in other words, in the whole process of approvals and design, there is a process which enables controlled release from the run-off pond.
This is the first time that such a release has had to be approved for that McArthur River Mine, which obviously indicates the very unusual severity of the current flood conditions. Approximately 40 megalitres of water is being released every 24 hours. This represents just 1/1000th of the flow in the adjacent Barney Creek.
The water at the release point obviously contains elevated levels of lead and zinc, and they are both substances which do occur naturally in the McArthur River system. We have monitoring equipment set up 2000 m from the release point, downstream from the mine site, before the water enters the McArthur River. That monitoring equipment has found that lead levels are undetectable at that point, and that the zinc levels are within drinking water standards, that is before it even enters the river. There is no lead measurable and the zinc levels are at drinking level standards.
The licence to release water allows for a maximum of 1000 megalitres to be released, subject to ongoing monitoring. The water sampling, under the processes that are approved, must occur daily during the release period, and up to three days afterwards it is done daily, after the discharge has been ceased. It also has to then occur on a weekly basis until 30 April. So there is a process in place to continually monitor even when the water flows have been stopped.
I can assure honourable members that the approval to discharge water from any mine site into natural creeks or rivers certainly isn’t given lightly. The government is satisfied that it was essential in this case to prevent a potentially more serious situation if the dam had burst. But we are also satisfied the levels of contaminants discharged are well within acceptable limitations. There was certainly no threat to the environment, or to public health. I think that needs to be stressed. I have to say that the McArthur Rive Mine people always acted responsibly in regards to the environment, and this certainly is the case at the present time.
The Northern Territory Environment Centre, unfortunately, is not interested in the facts. They are obviously only interested in capitalising on the situation and to causing unnecessary alarm, and also denigrating the excellent environmental performance of the Northern Territory mining industry. I just say to the local media, in future, rather than reporting automatically claims by the Environment Centre, whose record unfortunately showed over the past that they have never been accurate or fully truthful with regards to the facts that they comment on, please make some inquiries to get the appropriate details so that there is not unnecessary alarm caused to the community by not reporting fully the facts but relying on the Environment Centre for that information.
In this situation, it is within the design parameters; it is within a process which received prior approval in the environmental impact processes; and the monitoring shows that there certainly is no detriment whatsoever to the environment.
Last updated: 09 Aug 2016