CHAIR-If there are no further questions for the trust, I thank you for coming along and sharing numerous bits of good news with us. I will now request the Supervising Scientist to join us.
[8.07 pm]
Senator LUDLAM-I have a couple of questions following up on the conversation that we had in
February-as you would probably expect-principally regarding the water that is escaping from the Ranger tailings dam. At a meeting of the Alligator Rivers Regional Advisory Committee, ARRAC, in Darwin on 7 April, it was reported that you stated you do not believe the seepage coming from under the Ranger tailings dam has left the Ranger lease area. Firstly, is that a correct reflection of your views and, if so, what is the basis for that assertion?
Mr Hughes-I did make a statement of that nature at the Alligator Rivers Regional Advisory Committee meeting. We undertake extensive monitoring of the surface waters on Magela Creek and on Gulungul Creek. We see no evidence of any process water leaving the site via that dam. There is a range of bores that surround the tailings dam and there is no indication of water leaving past those monitoring bores.
Senator LUDLAM-I might have misunderstood some of the comments that you made in February, where I thought you had acknowledged that seepage had reached retention pond 1 and from here had reached Conjiimba Billabong. You said that was at least a strong possibility, although I do not think you were able to confirm that at the time.
Mr Hughes-I would have to reconsider exactly what the words were that I said at the time. I probably
would have said that there may have been some indication of some water in retention pond 1. The reason for that is that retention pond 1 does contain some water from the site that could be contaminated groundwater. There are low levels of uranium in it, which has probably not come from the groundwater. It is more likely runoff water. Also, the wetland filtration system has its exit which feeds into retention pond 1 as well, and so there will be uranium going into that water from there. However, I cannot say whether an atom of uranium has come out of the RP1 wetland filter or whether it has come from groundwater. There is no way to know that.
Senator LUDLAM-If there is such a great degree of uncertainty, I do not understand why you would be making comments that seepage has not left the Ranger lease area. If you are not sure that it has then you are also not sure that it has not.
Mr Hughes-I could not tell you that an atom has not left the site. What I can tell you is that there is no significant amount of material leaving the site.
Senator LUDLAM-It sounds as though the evidence is quite ambiguous in that regard.
Mr Hughes-I am sorry, could you repeat that?
Senator LUDLAM-It sounds to me, from the comments that you were just making, that the evidence is actually quite ambiguous in that regard and that it is quite difficult to tell. It could be coming from a couple of different sources.
Mr Hughes-What you can tell is that there is no significant amount of material leaving the site.
Senator LUDLAM-I will go to the volumes of material coming out from under the dam. At the same
meeting it was also reported that the figure of 100,000 litres a day, which we discussed in February, was a theoretical figure based on modelling rather than a definite figure.
Mr Hughes-That is correct.
Senator LUDLAM-The view that you gave us in February was an estimate or a guesstimate? There is no actual data as such. It is a computer model?
Mr Hughes-It is based on modelling, yes.
Senator LUDLAM-Can you describe for us, in as much detail as you can, what action your office has
taken since February on this issue?
Mr Hughes-I have commissioned an independent review of the modelling that was previously carried out. I am expecting the results of that independent review sometime in June.
Senator LUDLAM-Just to recap on that, you have ordered a review of the model?
Mr Hughes-Yes. I have commissioned an independent company to conduct a review of the modelling.
Senator LUDLAM-Can you tell us who is doing that work for you?
Mr Hughes-It is a group called Aqua-Terra. They are based in Western Australia.
Senator LUDLAM-Is the cost of that consultancy reflected in the budget anywhere? Is that a significant outlay for your office?
Mr Hughes-It will be a figure of less than $10,000.
Senator LUDLAM-So it is not a major piece of work. Are they going on site and drilling holes or are
they just looking at the assumptions underlying the model?
Mr Hughes-No. They will be looking at the existing data.
Senator LUDLAM-The existing data does not really tell us a great deal or it did not as of February. Do
you have any more or less data than you were able to provide to us in February as to the magnitude of the seepage that is coming out from under the dam?
Mr Hughes-No. We have had no additional data since then.
Senator LUDLAM-Is there a reason you have not sought additional sources of data?
Mr Hughes-I did not see any need to seek any additional data in any urgent fashion.
Senator LUDLAM-It seems, in a way, that there is a degree of ambiguity in that you are not really able to be clear, one way or another, as to how much of the water is coming out in the first place. That is based on computer modelling. What about the water quality? How confident are you of the kinds and orders of magnitude of contaminants that are coming out of the water?
Mr Hughes-The monitoring bores that are scattered around the tailings dam are regularly analysed by ERA and those results are reported. The Northern Territory mines department also undertakes check monitoring of water bores on the site.
Senator LUDLAM-At the February session you undertook to check the status of ERA's groundwater
study and a number of other reports. Are you able to provide the committee with those reports tonight?
Mr Hughes-I do not recall undertaking to provide any reports.
Senator LUDLAM-No, not to provide them. I am asking you that now. In February, you undertook to
check the status of the ERA's groundwater study. You said you would go back and review it for your own information. I am just wondering whether that occurred and whether you are able to provide us with that.
Mr Hughes-Yes. I had a further look at the reports and that is why I decided that the best approach was to have an independent review of the modelling that had been undertaken.
Senator LUDLAM-Was the model designed by the ERA or its parent company or was it by your office?
Mr Hughes-No. The modelling was undertaken by a number of groups, but not by our office. We do not have anybody with significant expertise in groundwater modelling.
Senator LUDLAM-Is that external consultancies or a different part of the government that has created
that model for you?
Mr Hughes-No. The modelling was undertaken by ERA and by people who ERA commissioned to
undertake the modelling.
Senator LUDLAM-What are we talking about? Are we talking about a bunch of linked spreadsheets?
What does the modelling look like in this regard?
Mr Hughes-It is a combination of factors. There are a number of measurements that are factored into the model-transmissivities of the actual clays and things like that, transmissivities of the tailings themselves, pump down rates from bores immediately around the area, geological mapping, positions of faults, the geophysics that had been undertaken previously that indicated where the saline plumes were and that sort of thing. They are all built into the models.
Senator LUDLAM-It is not a purely theoretical model; you are actually feeding live groundwater data
from the bores into it and the computer is telling you where it thinks the stuff is going?
Mr Hughes-Yes, that is right. Essentially, there are no bores in the middle of the tailings dam so you do not know what is going on under the tailings dam. That is the theoretical part of the model. Lateral dispersion is not so difficult to determine.
Senator LUDLAM-That is what I was going to ask you about next. Do you have any idea of the extent
and volume of lateral seepage from the storage facility?
Mr Hughes-ERA has provided us with some contour maps of the distribution of saline waters around the edges of the tailings dam.
Senator LUDLAM-When you say ‘saline waters', what are the principal contaminants that are coming
out laterally?
Mr Hughes-The principal contaminant in the water is magnesium sulphate.
Senator LUDLAM-Is that originating in the process chemicals used in the plant or is that from the
chemistry of the tailings? Where is that coming from?
Mr Hughes-The magnesium comes from the rocks itself. The sulphate largely comes from the sulphuric acid which is used in the process.
Senator LUDLAM-What about traces of uranium or the various daughter isotopes?
Mr Hughes-The radionuclides tend to attenuate fairly quickly in the rocks in groundwater. They do not
travel very far.
Senator LUDLAM-Does that not depend on the volume of water and the scale of the pump that is
pushing them out into the landscape, though?
Mr Hughes-I guess that would have an effect, yes.
Senator LUDLAM-I would have thought a fairly important effect. A small volume of water will attenuate fairly rapidly, but there would be hundreds of thousands, if not millions, of tonnes of water within the dam.
Mr Hughes-When we spoke in October you asked me about the amount of seepage from the tailings dam and I said it was probably tens of cubic metres a day. I was under the impression that you were probably talking about lateral dispersion. Those numbers are probably still correct. It is probably less than tens of cubic metres a day. The 100-odd cubic metres a day, which is the number that you provided me with last time, is probably the theoretical value of what goes through the floor of the tailings dam and sits beneath the tailings dam. That is why I have said that there is not a large amount of concern about dispersion from the tailings dam, because most of it is just sitting under the tailings dam and that will be rehabilitated when ERA rehabilitates the tailings dam.
Senator LUDLAM-I would like to come to that in a moment. Can you tell us what advice has been
sought by the Commonwealth government or other agencies on its behalf on this issue since the February estimates session and what advice OSS has provided? Who has drawn on your expertise since that discussion in February?
Mr Hughes-Are you talking about this particular issue?
Senator LUDLAM-Yes. I realise there are a number of other processes afoot relating to the expansions of the mine. I am just staying with this specifically for the time being.
Mr Hughes-I honestly do not recall having provided advice to any other organisations.
Senator LUDLAM-No, not other organisations. Did the environment minister seek your advice, for
example?
Mr Hughes-We provided a briefing on the subject to the minister.
Senator LUDLAM-Was that requested or is that something that you would do as a normal part of your
work?
Mr Hughes-I think it was something that we did as a normal part of our work.
Senator LUDLAM-Was it just one briefing?
Mr Hughes-I think it has been updated on more than one occasion.
Senator LUDLAM-Was there anybody else apart from the minister?
Mr Hughes-I do not believe so.
Senator LUDLAM-Are you not sure?
Mr Hughes-There was a discussion of the issue at the Alligator Rivers Region Advisory Committee and the Alligator Rivers Region Technical Committee.
Senator LUDLAM-That is all I am looking for. Was any specific advice sought by Northern Territory
government agencies or offered by your office?
Mr Hughes-I have also spoken at mine site technical committee meetings, and as I said before at ARRAC and ARRTC. The Northern Territory government has a representative at each of those meetings and so they were aware of that. They did not seek any specific briefings on the issue, nor did I give them any specific briefings outside of those particular meetings.
Senator LUDLAM-But they were at that table. The advice that you have given to your minister was not
sought or provided to the Northern Territory government?
Mr Hughes-No. We are not in the habit of providing briefs that we give to our minister to the Northern
Territory.
Senator LUDLAM-Presumably you would have provided them with more detailed information if they
had sought it to an appropriate degree?
Mr Hughes-The Northern Territory government's Department of Regional Development, Primary
Industries, Fisheries and Resources is actually the regulator of the site. As such, it has access to all the reports that we have and can seek additional information from ERA the same as we can.
Senator LUDLAM-Can you tell us what plans there are for further monitoring at the tailings storage
facility? Then we will move on to a different subject. Could you just describe for us the difference between the water-monitoring bores that you have and the statutory bores and the different reporting obligations that would come from each of those?
Mr Hughes-ERA have indicated that they plan to drill some additional monitoring bores in the vicinity of the tailings dam. We have not pushed them on the actual locations of those bores, pending the outcome of the review that I have commissioned from Aquaterra. One of the things that I said to Aquaterra was that I would like them to indicate any areas where they thought additional monitoring might be required as a result of the work that they undertake. With regard to statutory bores and non-statutory bores, ERA is obliged to provide statutory bore reporting in annual reports. It also provides some reporting of non-statutory bores in its water management system report.
Senator LUDLAM-But they are not actually obliged under any particular act; they are just providing that information.
Mr Hughes-That is right.
Senator LUDLAM-What is the number of non-statutory bores, compared with statutory bores on the
site?
Mr Hughes-My understanding is that there are four statutory bores on the site. I could not tell you the number of non-statutory bores, but it would be more than 100.
Senator LUDLAM-As to that disparity, is there a reason that they are required to report the results at four bores whilst there are several hundred that they keep to themselves? Or do they share that with your office?
Mr Hughes-They provide information on request to the regulators or to ourselves.
Senator LUDLAM-Do you have an open door? If you want to see all of those records, can you request
that?
Mr Hughes-We would be able to.
Senator LUDLAM-Is it something that you do?
Mr Hughes-We review their water management systems reports on an annual basis.
Senator LUDLAM-You will be aware that ERA put an EPBC referral to construct a heap leach plant and
a new tailings down at Ranger. That occurred since the session in February. That has been determined as a control action by the Commonwealth and is going to require an EIS. Presumably your office will be quite closely engaged in that process. Can you just tell us what implications that new proposal might have for either ERA's or your ability and capacity to monitor and address the existing seepage at the dam? Is it going to make your life more difficult?
Mr Hughes-I do not anticipate that it would make life any more difficult.
Senator LUDLAM-My understanding is that a new tailings dam is actually proposed to handle the waste from the heap leach plant.
Mr Hughes-Yes, it is part of that proposal.
Senator LUDLAM-Will that new dam impact on any of the water-monitoring sites that ERA currently
reports on?
Mr Hughes-The exact location of the dam in the referral was given as ‘requiring further work' to actually work out where to put it, but there is an indicative location given in the referral as being situated to the south of the existing dam. There is not a great deal of seepage evident in bores to the south of the existing dam.
Senator LUDLAM-The dam would potentially flatten some of the bores, though. Would you have to
relocate them?
Mr Hughes-Yes.
Senator LUDLAM-Is the new dam on the same sort of scale, of the same order as the one that we are discussing tonight?
Mr Hughes-Yes, in the referral it appears to be a similar size.
Senator LUDLAM-Is that new dam going to change groundwater movements or seepage patterns? Are we going to have two plumes instead of one?
Mr Hughes-Again, I would like to see more fully developed plans for that tailings facility.
Senator LUDLAM-Having not seen the referral documents myself, does ERA propose to line this tailings dam or is it a similar sort of proposal to what is leaking at the moment?
Mr Hughes-Again, it is only indicative that there is going to be a residue storage facility, which
indicatively was located to the south of the existing dam and was about the same size.
Senator LUDLAM-Is it indicatively lined or indicatively not?
Mr Hughes-It is not mentioned as being lined.
Senator LUDLAM-That probably tells us something. Is a new dam going to complicate the signature of existing dam seepage? You told us in February and you have intimated again tonight that it is difficult to tell the source of any given atom-whether it is coming as run-off, surface seepage or groundwater seepage-and now we are putting another large dam in the middle of that complex situation. Is that going to make tracking the plumes that already exist harder?
Mr Early-I think we are getting into the realms of the hypothetical at this stage. As you know, this is a controlled action. It all goes through a very rigorous environmental assessment process, which will actually tease out some of these issues. It is a bit premature to be answering them at this stage.
Senator LUDLAM-I am not looking for detailed data that does not exist yet. I point out to you that the first dam went through a rigorous environmental process and it is leaking 100,000 litres of water a day. Is contemplating a second dam of the same sort of order anything that your office has given any time or attention to?
Mr Early-The referral has been put in under the EPBC Act and there is a limited amount of information contained in that referral. It will now go through an assessment process which will provide an enormous amount of material, which will then be assessed. The supervising scientists will play a key role in advising on that. But at this stage it is really a little bit premature to be making comments on the basis of what is a reasonably short referral document from the company.
Senator LUDLAM-Will your office play a role in seeking or requesting specific information from the
company once you have seen the document?
Mr Early-We have to agree what the guidelines are for the assessment. That is all to come.
Senator LUDLAM-Is that a yes? If you see the referral documents are deficient in any particular regard, can you request more information?
Mr Early-The referral documents by their very nature are deficient in terms of making a final decision-
Senator LUDLAM-They are a sketch.
Mr Early-Yes. The referral documentation is sufficient to enable the minister to make a decision. Whether or not approval is required, that decision has been made and we now move on to the next stage, where we receive the detailed information, which goes through detailed analysis.
Senator LUDLAM-To finish up with Ranger, in February you agreed that ERA acknowledged that the
only way to remediate a contaminated plume of this kind is to pump the water out and cover the contaminants. Is that still your understanding?
Mr Hughes-Yes.
Senator LUDLAM-I guess that is opposed to the removal of the dam or the burial of the material back in the pit. Can you describe for us what it would look like, what the total volume of water is and how you remediate a plume on that scale that will have been there for 20 years or so leaking 100,000 litres a day or whatever the volume might be?
Mr Hughes-At the moment ERA are constructing a process water treatment plant, which is to clean up
process water to a state which will be fit for release to the environment.
Senator LUDLAM-What happens to the contaminants? Are they removed? What becomes of them?
Mr Hughes-They are transferred to the pit.
Senator LUDLAM-There was a public statement by ERA on 13 March that the seepage issue is ‘well
monitored and well understood by us and the regulators'-I presume you would agree with that-and that ERA have ‘a comprehensive rehab plan to remedy any effects on the surrounding area'. Can you tell us what that plan entails, and would you provide the committee with a copy of the rehabilitation plan? To what degree are those documents in the public domain?
Mr Hughes-The annual plan of rehabilitation is a document that is provided to the Department of
Resources, Energy and Tourism. The resources minister is the minister with responsibility for the Atomic Energy Act. Ranger sit on the Ranger project area, which is created by an authority under the Atomic Energy Act, so they are the people who look after that aspect of the program. We read the plan, but the plan belongs to RET.
Senator LUDLAM-Is your role more operational rather than end of mine life? Are you looking after the impacts in the here and now rather than what might happen in 10 years?
Mr Hughes-No, we will be contributing to the rehabilitation work at the end of mine life.
Senator LUDLAM-Are you confident that the company has put down enough of a bond to coordinate
and pay for a clean-up of this sort of scale?
Mr Hughes-The plan is costed on an annual basis-
Senator LUDLAM-Is a proportion of royalties being put aside and being put into a separate account?
Mr Hughes-Each year ERA reviews the plan and resubmits the plan with revised costings. The plan of the work that is being undertaken or is suggested is going to be undertaken is reviewed by the regulator, ourselves and the Northern Land Council, who comment on that plan. The plan then goes to the Department of Resources, Energy and Tourism, who pass the plan on then to an independent quantity surveyor who actually costs the plan out. Then officers of the Department of Resources, Energy and Tourism talk to ERA about the final figure for the bond each year. It is a fairly rigorous process.
Senator LUDLAM-You might direct me to a different agency if this is not something that would be your responsibility. There was just over $8.3 million over four years out to 2012-13 in the portfolio budget statements to implement comprehensive environmental monitoring and maintenance, including repair, where necessary, at the former Commonwealth Rum Jungle uranium site in the Northern Territory-I know your remit extends further than just the Ranger mine. Is your office involved at all in that work, which I understand is ongoing?
Mr Hughes-The resources, energy and tourism minister-because this is part of his portfolio-has
written to our minister asking if our minister would support us being involved in the technical working group that will be providing input into that rehabilitation process.
Senator LUDLAM-Have you responded yet? You have been invited to participate.
Mr Hughes-We have actually been assisting the Department of Resources, Energy and Tourism with their work on that and they are working with the NT government on it.
Senator LUDLAM-You will have a role in that clean-up work?
Mr Hughes-I assume we will, yes.
Senator LUDLAM-Did that work begin under Howard government budgets of a couple of years ago or is that a brand new announcement?
Mr Hughes-No, this is a brand new announcement. There was a previous rehabilitation program run on the site in the early 1980s.
Senator LUDLAM-But obviously that was not successful. We still have fairly serious contamination at
that site. I guess your office would have unique expertise in this regard. Would you expect by October that there would be a firm commitment one way or another for your office's participation? If it is still a bit up in the air now, I am just wondering whether we could just put you on notice at this point that it would be interesting to come back at the next estimates session to provide us, if you are able to, with a bit more information about what that clean up will look like and what sort of involvement your office would have.
Mr Hughes-Yes, we will know what our involvement will be. But this is probably a question that is best
put to resources, energy and tourism, I would think.
Senator LUDLAM-The NT-
Mr Hughes-No, the Commonwealth.
Senator LUDLAM-I will return to that subject in October when we see you again.
