The 1965 consent
59 On 15 April 1965, the State Planning Authority of NSW granted a development consent to Allsands Pty Ltd. The consent authorised interim development by the extraction of sand from part portions 2 and 3 Parish of Sutherland Captain Cook Drive Kurnell (including land now comprised in the subject Lot 8) subject to conditions. There is some contention as to whether the company entered into an agreement with Sutherland Shire Council, satisfactory to the State Planning Authority, that it undertake to meet the conditions of consent as required by condition 7 of the approval. The applicant argues that either the evidence establishes the agreement was made or that the Council is estopped from asserting to the contrary against the interests of any successor to Allsands as a consequence of its subsequent conduct by entering a further agreement in 1968. Furthermore, as a matter of construction the making of the agreement was not prerequisite to the validity of the 1965 consent. The applicant also denies the claim by the second respondent that development was not commenced under the 1965 consent.
60 It is not the role of the Court to make a formal finding of validity or otherwise in relation to the standing of the 1965 consent. It is relevant nevertheless to appreciate that the consent granted in 1965 is on its face inconsistent with the terms of the 1968 consent agreement so that it is not unreasonable to assume the 1965 consent was replaced in 1968. The present application seeks to extract well below the levels contemplated in 1965 and 1968. In my view it is not a relevant consideration to compare the environmental impact that might be caused if an earlier consent is implemented with the possible consequences of granting consent to a new application. It is the role of the consent authority to consider the merits of the application before it and to make an assessment based on the evidence in respect of the relevant issues.
61 There is nothing in s 79C of the EPA Act or elsewhere which allows the Court exercise its discretion to grant consent (in this case, at least, virtually uniformed) on the basis that one option would be the lesser of two evils. Moreover, the applicant expressly states that the submissions made on its behalf in respect of town planning considerations do not depend upon the validity and/or substantial commencement of development under the 1965 consent. According to Mr Craig the import of the 1965 consent is (that subject to the confinement of the area to be marked; the maintenance of then natural surface levels at certain points; a specification for the finished slope of any excavation below the existing natural surface was not to exceed 1 vertical on 10 horizontal and the stipulation that excavation may not go below reduced level 10 feet on Standard Datum) it permits the removal of the sand dune on Lot 8. Whether or not that removal should occur is an issue to be decided under current circumstances and without reference to the effect of the earlier consent whatever its status.
62 The 1965 consent in its original form, or as modified in 1968, will not be taken into account by the Court. It is an irrelevant and extraneous consideration.
Groundwater
63 The experts on groundwater are: Mr Peter Dundon for the applicant; Mr Colin Mackie, for the first respondent; and Mr Christopher Jewell for the second respondent; all of them hydrogeologists. The three experts reached a high degree of agreement. Mr Michael Williams, who is Principal Hydrogeologist of the Science and Information Division of the Department of Natural Resources, also gave evidence. His evidence was not in the interest of any party. His role in the proceedings was to explain the Department's position in relation to cl 25 of SREP 17.
64 The three aspects of groundwater to which the experts turned their attention were groundwater levels, flows and contamination. While groundwater contamination was not formally included within the scope of issues to be addressed, it was nevertheless a topic on which the experts expressed an opinion. Mr Williams introduced a fourth aspect of groundwater, namely volume.
65 As regards groundwater levels, Mr Dundon, Mr Mackie and Mr Jewell agreed that the proposal is likely to cause the following changes:-
· An area of about 5 ha centred on the final location of the dredge pond and an area of 2 ha along the western boundary of Lot 8 will decrease groundwater levels by 0.3 m to 0.5 m;
· An area of about 60 ha to the southwest of Lot 8 will decrease groundwater levels by about 0.2 m to 0.3 m;
· Groundwater levels to the south and east of the site will decrease by about 0.2 m;
· If there is concern about the decrease to the south and east (because of impact on flora and fauna), the level of the groundwater can be kept constant by the use of infiltration ponds, which draw water from rain and the dredge pond.
· Groundwater levels to the north of the site will increase;
· The maximum drawdown at any section of the coast will be along part of the Bate Bay shoreline and will be about 0.1 m,
· The impacts on groundwater levels are temporary; it is expected that ten years after the completion of sandmining the groundwater levels will recover their present levels.
66 Neither Mr Jewell nor Mr Mackie believes that the above changes are unacceptable. However, Mr Jewell had three reservations. First, he pointed out that the infiltration basin proposed by Mr Dundon to keep groundwater levels to the south and east constant was more in the nature of an idea than a design. The expression he used in this regard was that the devil is in the detail Secondly, in his view the model used to predict groundwater levels had a margin for error of up to 0.5 m. Thirdly, Mr Jewell thought that the cumulative impact of the proposal, together with the existing operations on the Besmaw and Consolidated Developments sites, should also be considered.
67 Mr Jewell's first concern could be overcome by a deferred commencement condition or, preferably, by the Court giving the applicant an opportunity to design the infiltration basin before a final approval. His second concern regarding possible inaccuracies of the predictive model seems to me a problem that is present in the use of any predictive model that attempts to simulate the real world. There was no suggestion that Mr Dundon could have used a more accurate model. In the circumstances I intend to regard possible inaccuracies of the model as an aspect of making any decisions about future development. As regards Mr Jewell's concern with cumulative impacts, Mr Dundon provided the Court with predictions of those impacts. I deal with this aspect below.
68 In respect of the impact on groundwater flows, Mr Dundon, Mr Mackie and Mr Jewell agree on the following:
· Groundwater flows to Quibray Bay will decrease by a maximum of 8% in year 1 of the project. Ten years after the project's completion there will be a long-term increase of 5% in groundwater flows. This is a positive impact.
· Groundwater flows to Bate Bay will decrease by 8% in year 1 of the project. The maximum reduction of 16% will occur at the end of the project. Ten years after the project's completion there will be long-term decrease in groundwater flows of 6%.
69 The experts agree that these impacts are environmentally acceptable.
70 Mr Dundon and Mr Jewell agree on the following impacts on groundwater quality. (Mr Mackie's expertise does not include water contamination.)
· The groundwater beneath the adjoining Lot 8 is now contaminated. It contains elevated concentrations of cyclohexane, total petroleum hydrocarbons and ammonia.
· The Rocla sand extraction may accelerate the migration of contaminants towards the dredge pond for limited periods.
· The dredge pond will facilitate volatilisation to the atmosphere of cyclohexane and total petroleum hydrocarbons. It is also likely to enhance degradation of ammonia.
71 Mr Jewell and Mr Dundon agree that any groundwater contamination issues, being off-site, are manageable either by direct action by Rocla or enforcement action by the Government against neighbouring landholders.
72 At Mr Jewell's request, Mr Dundon assessed the cumulative impacts and found them not to be of great significance compared to the impacts of the Rocla project proceeding alone. There would be an additional increase in groundwater levels, though the difference would not be great. Groundwater flows towards Quibray Bay would not be significantly greater for the cumulative scenario than for the Rocla project alone. The cumulative impact on flows towards Bate Bay would be smaller than for the Rocla project alone.
73 While the information on cumulative impacts reached Mr Jewell too late to allow him sufficient time for informed comment, I note that he did not request the Court for additional time. I assume therefore that, in general, he trust the results of Mr Dundon's modelling. The evidence of Mr Dundon, Mr Mackie and Mr Jewell suggests that the impacts on groundwater levels, flows and contamination are acceptable. The above conclusion is subject to the Court being satisfied that an infiltration basin at the southeast boundary will keep groundwater levels constant to the south and east of the site.
74 As stated above, Mr Williams is also an hydrogeologist but his evidence deals specifically with the Department of Natural Resources' position on cl 25 of SREP 17.
75 Despite the three experts reaching general agreement that the proposal's environmental consequences were acceptable, Mr Williams maintained that the impacts were unpredictable for the following reasons:-
· The excavation to below the aquifer material would extinguish the existing groundwater resource of the site. The highly permeable sand would be replaced with VENM, a material of low permeability. This changes the volume of groundwater even where the level of the water table remains generally the same.
· There remains uncertainty about the proposal's impact on groundwater contamination.
· Backfilling with VENM has the potential to introduce further contamination into the groundwater on the site by releasing iron. (Mr Dundon responded to this by saying that there was no evidence in the groundwater of the presence of iron despite backfilling by VENM on nearby sites. On the other hand, the evidence suggests that groundwater contamination on nearby sites may have been caused, at least partly, by VENM backfilling.)
· The model relied on by Mr Dundon, Mr Mackie and Mr Jewell is inaccurate. The results it predicts are fraught with uncertainty.
76 In summary, the evidence of Mr Dundon, Mr Mackie and Mr Jewell suggests that there is not likely to be unacceptable environmental harm to the groundwater below and around the site as a result of the proposal. This does not mean, however, that Mr Williams' evidence is without force. Apart from a lack of confidence in the model used by Mr Dundon to predict the true impact on groundwater, Mr Williams' basic reason for not accepting that satisfactory arrangements for the proper utilisation and protection of groundwater have been made was that, once the site is excavated to below the aquifer and filled with VENM imported from outside the site, the aquifer ceases to be the same natural resource that it was before excavation. Given that the disturbance to the aquifer on the site is total, Mr Williams' position is not unreasonable. His evidence is important when I come to consider the effect of the provisions of cl 25, later on.