BP AUSTRALIA PTY LTD -v- CONTAMINATED SITES COMMITTEE [2012] WASC 221 (25 June 2012)

Contaminated Sites Act 2003 (WA), s 3, s 4, s 8, s 11, s 13, s 15, s 18, s 24, s 25, s 25(3), s 25(5), s 25(5)(b)(ii), s 26, s 27, s 29, s 33(2), s 36, s 37, s 38, s 39, s 42, s 43, s 50, s 55, s 77, s 78, pt 3, pt 3 div 2, pt 2, pt 3, pt 3 div 3, pt 4, pt 5, pt 8 div 2, sch 1

Environmental Protection Act 1986 (WA), s 49(1)

Interpretation Act 1984 (WA), s 5

State Administrative Tribunal Act 2004 (WA), s 105

Intervenors : State Solicitor for Western Australia

1 BP Australia Pty Ltd (BP) appeals from a decision of the Contaminated Sites Committee (the Committee) to the effect that BP is to bear 36% of the responsibility for remediating a contaminated site situated at the corner of Gnangara Road and Mosey Street, Lansdale, and which was operated for a number of years as a BP service station (the site). Although BP, as a party aggrieved by a decision of the Committee, has a right to appeal to the Supreme Court from that decision, the appeal can only be brought on a question or questions of law. For the reasons which follow, BP has failed to establish that the Committee erred on any question of law properly identified within its grounds of appeal, and its appeal must be dismissed, and the decision of the Committee affirmed.

The Contaminated Sites Act 2003 (WA)

2 In order to set the scene for a narration of the proceedings before the Committee, it is appropriate to start with an overview of the Contaminated Sites Act 2003 (WA) (the Act).

3 Although the Act received Royal Assent in 2003, it did not commence operation until 1 December 2006. The long title describes the Act as an Act providing for the identification, recording, management and remediation of contaminated sites. Those purposes are evident in the scheme of the Act, and in the text of s 8, which provides that the object of the Act is to 'protect human health, the environment and environmental values by providing for the identification, recording, management and remediation of contaminated sites in the State', having regard to three principles described as:

1. the polluter pays principle;
2. the principle of full life cycle costs; and
3. the principle of waste minimisation.

4 The term 'contaminated' is defined by s 4 of the Act to mean 'in relation to land, water or a site ... having a substance present in or on that land, water or site at above background concentration that presents, or has the potential to present, a risk of harm to human health, the environment or any environmental value'. The word 'site' is defined by s 3 to mean an area of land, and to include both underground and surface water on an area of land.

5 Part 2 of the Act provides for the reporting, classification and recording of contaminated sites. Section 11 provides for the reporting of known or suspected contaminated sites to the CEO of the department (relevantly the Department of Environment and Conservation), and imposes a duty to report upon certain persons, including owners or occupiers of a site and persons who know or suspect that they have caused or contributed to the contamination of a site. Section 13 provides for the classification of sites by the CEO in accordance with the classifications set out in sch 1 to the Act. The classifications included within that schedule include 'contaminated - remediation required', the criterion for which is a finding that the site is contaminated and remediation is required. 'Remediation' is defined by s 3 to include the attempted restoration of the site to the state it was in before the contamination occurred and the removal of the substance causing the contamination or the reduction or mitigation of the effect of the substance. BP accepts that the site the subject of these proceedings was properly classified as 'contaminated - remediation required'.

6 Section 15 obliges the CEO to give written notice of the classification of a site to a variety of persons including each owner and occupier of the site. Section 18 provides that certain persons, including those who reported the site, owners and occupiers who have been given notice can appeal to the Committee against the classification given to a site by the CEO. Such appeals are governed by the provisions of div 2 of pt 8 of the Act. Other sections within pt 2 of the Act provide for the maintenance of a publicly accessible database of contaminated sites.

7 Part 3 of the Act makes provision for the remediation of contaminated sites, and contains various rules by which the person or persons responsible for remediation may be identified. Subject to certain exceptions which are not material to the present case, s 24 provides a hierarchy of responsibility as follows:

(a) in accordance with s 25, the person who has caused or contributed to the contamination of the site;

(b) in accordance with s 26, if the person is an owner or occupier of the site who has changed, or proposes to change, the use to which the land that comprises all, or part, of the site is put;

(c) in accordance with s 27, if the person is an owner of the site, or of a source site (a site from which contamination has migrated to another site - see s 3).

In addition, s 29 provides that the State is responsible for remediation in certain circumstances, including the circumstance in which no other person is responsible for remediation of the site.

8 Thus, consistently with the polluter pays principle, s 24 provides that the primary persons responsible for the remediation of a site are those who have caused or contributed to the contamination of the site, as determined by the application of s 25. That section is central to this appeal. It provides:

1. Person who caused, or contributed to, contamination - responsibility for remediation

(1) A person is responsible for remediation of a site to the extent that the person caused, or contributed to, the contamination of the site after the commencement of this Act.

(2) Subsection (1) applies whether the contamination resulted from an act that was done with lawful authority or without lawful authority.

(3) A person who caused, or contributed to, the contamination of a site before the commencement of this Act is responsible for remediation of the site only to the extent that the person caused, or contributed to, that contamination by an act that was done without lawful authority.

(4) This section does not apply if the contamination resulted from a reasonable act that was carried out in an emergency situation to save life or to protect property or the environment.

(5) In this section -

an act that was done without lawful authority, without limiting the meaning of the expression, includes an act -

(a) that constituted an offence for which the person was convicted; or

(b) that contravened -

(i) any written law in force at the time the act occurred; or

(ii) any contract, permit, lease, licence, standard, policy, direction, exemption, authority, approval or requirement, however described, that was given or made under a written law in force at the time the act occurred.

(6) This section is subject to sections 26 and 27.

9 Also relevant to the meaning to be given to the expression 'an act that was done without lawful authority' is s 3 of the Act which provides that the word 'act' includes an omission and extends to a series of acts or omissions (see also Interpretation Act 1984 (WA), s 5).

10 Section 26 provides that where an owner or occupier of a site has changed or proposes to change the use of land, that person is responsible for remediation of the site to the extent that remediation is required because of the change or proposed change of use.

11 Section 27 contains various provisions with respect to the responsibility of landowners for remediation, depending upon whether they became an owner prior to the commencement of the Act and/or the extent to which others are responsible for remediation of the site pursuant to s 25 or s 26.

12 Division 2 of pt 3 creates the Committee and provides that it is to determine its own procedures and is to 'act according to equity, good conscience and the substantial merits of the case, without regard to technicality or legal forms, is not bound by the rules of evidence and is to conduct its inquiries in any manner it considers appropriate'.

13 Division 3 of pt 3 provides for the Committee to make decisions as to responsibility and the extent of responsibility for remediation of a site. Section 36 provides that the Committee may make such a decision either on its own initiative, or at the request of an interested person. Section 37 provides that before making a decision that a person is responsible for remediation, the Committee is to give written notice to that person including notice of certain matters. If the decision is proposed to be made in accordance with s 25, the notice must specify the nature of the contamination that the Committee reasonably suspects the person caused or contributed to, and the extent of the contamination that the Committee reasonably suspects that the person caused or contributed to.

14 If the decision is proposed to be made in accordance with s 25(3), the notice must also specify the act that the Committee reasonably suspects the person carried out without lawful authority and give details of the conviction of the person for the offence that was constituted by the act or any contravention described in par (b) of the definition of 'an act that was done without lawful authority' in s 25(5). The notice must also set out any other matters regarding responsibility for remediation that are relevant, and inform the person that if he or she wishes to disagree with any statements made in the notice, they may make a written submission to the Committee giving reasons for the disagreement and providing any information or documents supporting those reasons.

15 Section 38 requires the Committee, when making a decision as to responsibility for remediation, to take into consideration the contents of any notice given by the Committee under s 37, any submission made to the Committee and any information or documents provided in support of that submission by a person to whom notice was given. Section 39 requires the Committee to ensure that written notice of its decision as to responsibility for remediation is given to each person who the Committee has decided is responsible for remediation, and a number of other persons (who need not be particularised). The section specifies the matters which must be included within such a notice and includes 'the reasons for the decision'.

16 Section 40 provides that a person who has been given notice of a decision in accordance with s 39(1) may appeal in accordance with s 77 of the Act. That section provides a right of appeal to the Supreme Court on a question of law, and only on a question of law. Section 78 provides that the Supreme Court is to hear and determine the question of law arising on the appeal and, as the court sees fit, is to:

(b) substitute or vary the decision appealed against; or

(c) remit the decision to the Committee for reconsideration together with the court's opinion on the question of law.

17 Part 4 of the Act empowers the CEO to issue various kinds of notices, including notices that require the investigation, clean-up or abatement of hazards arising from the contamination of a site. Under s 42 of the Act, notice may be given by the CEO to a person responsible for remediation of a site that has been classified as 'contaminated - remediation required'. Section 43 of the Act obliges a person on whom the notice is binding to ensure that the requirements of the notice are complied with within the time specified in the notice, and provides for the imposition of penalties in the event of noncompliance. The notices that may be served by the CEO include a clean-up notice, which by s 50, is to set out the requirements to be complied with in order to remediate a site. A clean-up notice may only be given if the site has been classified 'contaminated - remediation required'.

18 Part 5 of the Act confers various powers on the CEO with respect to remediation and ensuring compliance with notices. Those powers include the taking of such action as the CEO considers necessary to ensure that the requirements of the relevant notice are complied with (s 53(1)(a)). Section 55 provides that the CEO may recover the reasonable costs incurred in taking such action, together with interest, from any person on whom the relevant notice was binding. In other words, if the person served with notice requiring remediation of the land does not take the requisite action, the CEO make take that action and recover the costs of doing so from the person responsible.

19 The site has been used as a service station and for various associated uses since 1977. Its owners and lessees have changed from time to time. Leakage of fuel (hydrocarbons) into the soil of the site was detected at least as early as 1996. Other instances of leakage of fuel into the soil in 2001 and 2003 have been identified. Because of the changes in the identity of the owners and lessees of the site over time, liability for remediation of the site has been controversial since at least 1997.

20 On 16 November 2007, the site was classified as 'possibly contaminated - investigation required' under the Act. On 18 July 2008, the CEO decided to reclassify the site as 'contaminated - remediation required'. Notice of that decision was given to various persons, including the Committee, by letter dated 24 July 2008.

21 On 10 September 2008, Mr Ahmed Eldesouki and Mrs Rokaya Eldesouki who were then (and remain) the owners of the site, requested the Committee to make a decision under s 36 of the Act with respect to responsibility for the remediation of the site.

22 In the latter part of 2008 and during 2009, the Committee requested information and submissions from various persons who had been owners or lessees of the site at different times. In response to a request from the Committee, BP, through its solicitors, provided a submission to the Committee in September 2009, together with various documents referred to in that submission.

23 In that submission, BP advised the Committee that it had taken a lease of the site between 15 December 1982 and 13 December 1997. BP provided the Committee with a copy of a lease dated 10 January 1983 between the then owner of the site, Mr George Hrga, and BP, providing BP with a lease of the site for a term of five years commencing on 15 December 1982, together with an option to renew the lease for a further term of five years. BP also provided the Committee with a copy of a deed of variation dated 20 October 1986 by which the owner granted BP an option for a further term of five years, commencing upon the expiry of the first option term. Although BP did not provide the Committee with any document relating to the exercise of the second option, given that BP remained lessee of the site until the expiry of the second option term, it is implicit from the terms of BP's submission that it exercised the second option.

24 BP also advised the Committee in the submission that Mr and Mrs Eldesouki had been sublessees of the site from BP between December 1987 and the expiry of BP's lease in December 1997. In the interim, Mr and Mrs Eldesouki had acquired ownership of the land from Mr Hrga, together with a Mr and Mrs Cerinich, although at some point Mr Cerinich acquired his wife's interest in the land, and then much later sold his half interest in the land to Mr and Mrs Eldesouki.

25 In its submission to the Commission BP referred to the discovery of contamination of the site in 1996. It submitted that 'it was pipe work associated with the tanks that caused the contamination discovered in 1996'. BP submitted that its interest as lessee included the demise of all improvements on the site which included the tanks and associated pipe work. It acknowledged that the lease required BP, as lessee, 'to keep and maintain the demised premises ... in good and tenantable repair, order and condition having regard to their condition at the commencement of the term (fair wear and tear ... excepted ...)', but submitted that the leak in the pipe work was the result of fair wear and tear, and therefore fell outside its obligations as lessee. BP also referred the Committee to certain provisions of a sublease between BP and Mr and Mrs Eldesouki, which covered a period of just over two years commencing on 1 October 1995 and expiring on 13 December 1997, and submitted that by reason of those terms, the sublessees and occupiers of the site, Mr and Mrs Eldesouki should be regarded as having caused the contamination.

26 The submission and documents received from BP were circulated by the Committee to the other persons prospectively liable for remediation of the site, who were invited to provide any submissions and information to the Committee in response to BP's submissions.

27 By letter dated 10 August 2010, the chairman of the Committee wrote to the solicitors acting for BP drawing attention to changes in the fuel pumps situated on the site, which apparently occurred some time between the execution of documentation in February 1989, and documentation executed in October 1995, as different pump serial numbers are recorded in the two sets of documents. BP was requested to advise the date upon which the pumps were changed, and to provide copies of any documentation relating to the work done. Solicitors acting on behalf of BP responded to that letter by letter of 20 October 2010, advising that despite exhaustive search and inquiry of relevant personnel, it was not possible to identify the date upon which the pumps were changed. The letter did not contest the proposition that it was a fair inference from the documents to which the Committee had referred that the pumps were changed by BP at some time between February 1989 and October 1995.

28 By letter dated 2 November 2010, the Committee gave notice pursuant to s 37 of the Act to persons in respect of whom it was considering making a decision as to responsibility for remediation of the site. Those persons were Mr and Mrs Eldesouki, Mr Cerinich, BP and Whitegum Petroleum Pty Ltd, which had been lessee of the site since December 1997. The letter advised those persons that the Committee was proposing to decide that responsibility for remediation of the site be allocated to Mr and Mrs Eldesouki as to 40%, to BP as to 30%, to Whitegum Petroleum Pty Ltd as to 20% and to Mr Cerinich as to 10%.

29 The letter enclosed a summary of the provisions of the Act, a list and description of all the documents that had been received and considered by the Committee, and a table which set out the different periods considered by the Committee for the purposes of allocating responsibility for remediation. That table contained 15 different periods, showing the starting date and end period of each, identifying the event giving rise to the start of the period, any documents relevant to that event, and the relevant owners, lessee and franchisee over each period.

30 Also included with the letter were detailed tentative findings in respect of the periods identified on the chart and numbered 6, 7, 8, 11 and 12. It is clear from those documents that the Committee was proposing to allocate 50% of the responsibility for remediation of the site to those who caused or contributed to contamination during period 6, 5% in respect of period 7, 10% in respect of period 8, 10% in respect of period 11, and 25% in respect of period 12.

31 The attachments informed the recipients of the correspondence that the Committee was tentatively disposed to allocate responsibility for remediation of the site on the basis of a finding that BP had caused or contributed to contamination of the site during each of periods 6, 7 and 8. Together those periods covered a consecutive period between 25 December 1992 and 7 October 1997. The table indicating the 15 different periods, and the tentative finding in respect of period 6 showed that the Committee was disposed to select the date of 25 December 1992 as the likely approximate date of installation of new dispensing equipment at the site. The end of period 6 was the day before Mr Cerinich acquired Mrs Cerinich's interest in the site. Period 7 commenced immediately following the expiry of period 6, and therefore upon the acquisition by Mr Cerinich of his wife's interest in the site, and ended immediately prior to the commencement of a franchise agreement between BP and Mr and Mrs Eldesouki on 1 October 1995. Period 8 commenced on that date, and ended on 7 October 1997 when the leak was repaired.

32 In respect of each period, the tentative findings of the Committee were to the effect that the source of contamination was a leak from underground pipe work dating from the installation of the new dispensing equipment, which was estimated to be 25 December 1992. The document disclosed a tentative finding to the effect that contamination from that source was caused or contributed to by a failure to maintain the underground pipe work, including a failure to ensure the underground pipe work was sound and a failure to enforce covenants by others to maintain the equipment, and by the act of continuing to use the underground pipe work when in disrepair. The tentative findings in respect of each period indicated that the Committee was disposed to find that BP was solely responsible for what it had characterised as a failure to maintain the underground pipe work, and Mr and Mrs Eldesouki were solely responsible for the act of continuing to use the underground pipe work when in disrepair. The tentative findings indicated the Committee's disposition to allocate responsibility for contamination caused during this period (ie periods 6, 7 and 8) equally to BP on the one hand, and Mr and Mrs Eldesouki on the other.

33 The letter from the Committee invited submissions and any further information from each of the persons in respect of whom the Committee proposed to make a determination as to liability. BP responded to that request by a letter from its solicitors dated 23 December 2010. Submissions were made challenging the tentative finding that the leak in the pipe work dated from the installation of the new dispensing equipment, and the finding that the date of installation was on or about 25 December 1992. BP submitted that the leak did not occur until some time after 30 October 1993, and could not have been caused by the installation of the new dispensing equipment, based on an inspection report dated 29 October 1993 (albeit that the report appears only to relate to superficial inspection of above ground equipment and makes no reference to any inspection or testing of underground pipes or any assessment of whether fuel was leaking into the soil).

34 Under the heading 'Evidence of Responsibility for Remediation' in its submission, BP accepted the tentative finding of the Committee to the effect that under the terms of its lease of the site, BP would have been obliged to maintain the lessor's fixtures, fittings, installations and facilities and the lessee's fixtures, fittings and equipment. In that context, BP submitted:

Clause 2(c) of the Head Lease states that BP is required to maintain the demised premises and all additions including fixtures, fittings, installations and lessee's fixtures, fittings and equipment 'well and sufficiently repaired' and 'in good and tangible [sic tenantable] repair ... having regard to their condition at the commencement of the term (fair wear and tear ... excepted).' The demised premises means land and improvements. Accordingly, the demised premises include the tanks, associated pipe work owned by the owner of the Site (noting that one of the parties was also the occupier and sublessee) and dispensing equipment owned by BP.

35 The letter went on to reiterate the submission previously made to the effect that the leak in the pipe work was a result of fair wear and tear.

36 BP also submitted that the underground pipe work was not the subject of an equipment loan agreement between BP and the owners of the site and again drew the attention of the Committee to the sublease between BP and Mr and Mrs Eldesouki, reiterating its submission that under the terms of the sublease, Mr and Mrs Eldesouki were responsible for the maintenance of the underground pipe work.

37 In its submission, BP contested the tentative finding that BP had caused or contributed to the contamination by an act done without lawful authority because it had caused pollution in contravention of a provision of the Environmental Protection Act 1986 (WA) (EP Act) then in force; namely, s 49(1). BP also contested the proposition that 50% of responsibility for remediation of the site should be allocated to periods 6 8 inclusive, asserting that subsequent contamination events were more significant than contamination during periods 6 8.

38 The Committee notified those who had been identified as possibly responsible for remediation of the site of its decision by letter dated 20 July 2011. That letter advised those parties that the Committee had considered the submissions which had been received and had adjusted its view of the allocation of responsibility in light of those submissions. The Committee advised the parties that the changes in allocation of responsibility were a result of an increase in the length of time within period 6 and the inferred extent of contamination coming from the leaking anaconda during period 6.

39 The Committee advised that it had decided that the following persons were responsible for remediation to the extent indicated:

• Mr and Mrs Eldesouki, 41%
• Mr Cerinich, 5%
• BP Australia Ltd, 36%
• Whitegum Petroleum Pty Ltd, 18%

40 The Committee provided detailed reasons for its conclusion in a number of attachments to the letter. As in the notice given pursuant to s 37 of the Act, those attachments corresponded to the periods identified by the Committee as periods 6, 7, 8, 11 and 12. However, the commencement date of the sixth period had been altered from 25 December 1992 to 4 June 1992.

41 The reasons given by the Committee for its conclusions in respect of each of these periods correspond largely, but not exactly, with the reasons given for its tentative conclusions in the notice issued under s 37 of the Act. The differences of substance are:

(1) Period 6 has been altered to commence on 4 June 1992, instead of 25 December 1992.

(2) The reason given by the Committee for bringing forward the date for the commencement of period 6 was its view that the date of installation of the new dispensing equipment, which it considered to be the date of commencement of the leak from the anaconda joint, was earlier than previously thought, and was considered by the Committee to be 4 June 1992. The Committee gave its reasons for that view in the following terms:

[B]ased upon a slow leak from the 'weeping anaconda ...the large resulting plume ... the relatively flat hydraulic gradient (4.8 millimetres per metre) ... and the apparent speed at which the hydrocarbon contaminated groundwater has travelled from the location of dispensing equipment 6/7 ... the Committee considers that the leak was occurring for at least three (3) years, however it is more likely than not to have occurred for up to five (5) years, based on concentrations identified in off-site bores in 1997.

Each of the factual assertions in this paragraph were referenced to a document identified by a document number corresponding to the number of the document in an index of documents provided by the Committee with its decision.

(3) The Committee stated that it understood the anaconda to be a flexible pipe, which is part of the dispensing equipment and which connects the dispensing equipment to the underground pipe work.

(4) The Committee referred to an integrity test of the fuel lines connecting the fuel storage tanks to the dispensing equipment undertaken in early October 1997, and noted that after a valve was replaced at the anaconda valve joint, the lines were retested and found to be sound on 6 October 1997. The Committee noted that this was made known to BP on 7 November 1997 and that BP did not dispute that contamination arose from the leaking anaconda.

(5) References to the leak emanating from 'underground pipe work' were deleted and replaced with references to leaks from the 'anaconda joint' throughout the reasons.

(6) The percentage of overall responsibility for remediation of the site attributed to contamination occurring during period 6 was altered to approximately 22%.

(7) The percentage of overall responsibility for remediation of the site as a result of contamination during period 7 was altered to approximately 2%.

(8) The percentage of overall responsibility for remediation of the site as a result of contamination during period 8 was altered to approximately 28%.

(9) The allocation of overall responsibility for remediation of the site as a result of contamination occurring during the eleventh period was altered to approximately 8%.

(10) The percentage of overall responsibility for remediation of the site as a result of contamination occurring during the twelfth period was altered to approximately 19%.

42 It would have been apparent to anyone giving detailed consideration to the Committee's reasons that there must have been an error in those reasons, because the total allocation of responsibility for remediation of the site during the five periods covered by those reasons was only 79%. The error in the figures was identified by BP's solicitors, who wrote to the Committee on 11 August 2011 pointing out that the aggregate of the percentage of responsibilities allocated to BP in the detailed reasons was 26%, not 36%. The Committee replied to that letter on 20 October 2011, pointing that there had been a typographical error in its reasons, which should have recorded the percentage of responsibility for remediation allocated to period 6 as 42%, not 22%, and enclosing amended reasons for its decision.

43 However, with the exception of the allocation of responsibility to BP (of 36%), the allocations of responsibility set out in the amended detailed reasons do not correspond with the allocations of responsibility in the covering letter from the Committee. The aggregate of responsibility allocated between the five periods is 99%, not 100%, and according to the detailed reasons, the responsibility allocated to Whitegum Petroleum totals 13.5%, not 18%; the responsibility allocated to Mr Cerinich, 6.75%, not 5%; and the responsibility allocated to Mr and Mrs Eldesouki totals 42.75%, rather than 41% (assuming that responsibility for liability incurred jointly by Mr Cerinich and Mr and Mrs Eldesouki as allocated in proportion to their interests in the land - that is, half to Mr Cerinich and half to Mr and Mrs Eldesouki).

44 In this appeal, BP takes no point in relation to the correction of the typographical error in the Committee's reasons for decision. Although brief reference is made to the apparent mathematical discrepancies between the reasons for decision and the covering letter in relation to the responsibility allocated to other parties in BP's submission with respect to the adequacy of the Committee's reasons, it is not contended that these discrepancies have any impact upon the proportion of responsibility allocated to BP, given that the percentages in the detailed reasons allocated to BP tally with the aggregate percentage given in the covering letter. It is therefore unnecessary to give any further consideration to these mathematical discrepancies.

45 As I have noted, appeals from a decision of the Committee to this court are limited to appeals on a question of law. Appeals to this court from the State Administrative Tribunal are (with some exceptions) similarly limited (see s 105 of the State Administrative Tribunal Act 2004 (WA). It follows that the observations made by Buss JA (Wheeler and Pullin JJA agreeing) with respect to the scope of an appeal on a question of law in Paridis v Settlement Agency Supervisory Board [2007] WASCA 97 [53] can be applied to appeals from the Committee to this court.

46 The observations of Allsop P (Giles JA agreeing) and Basten JA in B & L Linings Pty Ltd v Chief Commissioner of State Revenue [2008] NSWCA 187; (2008) 74 NSWLR 481 on the scope of an appeal 'on a question of law' are also informative. As Basten JA points out, the scope of appellate jurisdiction conferred upon the court may be informed not only by the statutory description of the available grounds of appeal, but also by the statutory language used to describe the functions and powers of the court. Section 78 of the Act provides that the function of the court is to 'hear and determine the question of law arising on the appeal', and the court's powers include the power to 'remit the decision to the Committee for reconsideration, together with the court's opinion on the question of law'. The language of s 78 supports the conclusion at which Basten JA arrived in B & L Linings [150] to the effect that the function of this court is limited to the identification of an erroneous answer in respect of a question of law, and the court is not required, nor is it entitled, to embark upon any review of the decisionmaking process of the Committee beyond that necessary to answer the appropriately identified question or questions of law.

47 There are nine grounds of appeal. They are prolix, repetitive and confused. They fall manifestly short of identifying, with any clarity or precision, a question or questions of law upon which the Committee has erred. It has therefore fallen to the court to endeavour to winkle out of the appellant's grounds and submissions the question or questions of law upon which the appellate jurisdiction of the court depends. This happens too often.

48 As best I can understand ground 1, it contains three discrete propositions, namely:

(a) there was no evidence that BP was responsible for maintaining the anaconda joint;

(b) the Committee erred by failing to direct itself that it was required to be satisfied beyond reasonable doubt of BP's contravention of s 49(1) of the EP Act; and

(c) there was no evidence to support the Committee's finding that BP had contravened s 49(1) of the EP Act.

1(a) - No evidence that BP was responsible for maintaining the anaconda joint

49 There is no doubt that an allegation that there was no evidence to support a factual finding gives rise to a question of law (see Paridis and B & L Linings). However, the proposition that there was no evidence to support the finding that BP was responsible for maintaining the anaconda joint is hopeless. Both in its original submission to the Committee in September 2009 and in the submission which responded to the notice given under s 37 of the Act, BP's solicitors clearly and unequivocally accepted that under the terms of BP's lease of the site, it was obliged to maintain all fixtures and fittings on site. The lease was in evidence before the Committee, and its terms unequivocally imposed an obligation upon BP to maintain and repair all fixtures and fittings on site, including the anaconda joint.

50 The written submissions filed on behalf of BP assert that the Committee had to be satisfied beyond reasonable doubt that BP had committed a contravention of s 49(1) of the EP Act before it could conclude that BP had caused or contributed to the contamination of the site by an act that was done without lawful authority. However, during oral argument, counsel for BP resiled from this proposition, albeit in terms that were very difficult to follow (ts 30). When asked if there was any authority for the proposition that a Committee allocating responsibility for the remediation of a contaminated site and therefore allocating civil liability, was obliged to find a contravention of a written law beyond reasonable doubt as if the Committee were convicting the relevant person of a criminal offence, counsel for BP responded with the assertion that the proposition was selfevident (ts 30). Given the incurable enthusiasm of courts for stating and restating trite and obvious propositions of law - a characteristic which has endured for centuries - an assertion that there is no authority for a particular proposition because it is selfevident is unconvincing.

51 As one would expect, there is in fact authority which is directly contrary to the proposition that a court or administrative body engaged in the allocation of civil liability is obliged to apply the criminal standard of proof merely because the path to liability involves a finding which could also constitute the commission of a criminal offence.

52 Dealing firstly with the position of a court in civil proceedings, in Rejfek v McElroy [1965] HCA 46; (1965) 112 CLR 517, the High Court, in a joint judgment held:

This Court decided in 1940 in Helton v Allen that in a civil proceeding facts which amount to the commission of a crime have only to be established to the reasonable satisfaction of the tribunal of fact, a satisfaction which may be attained on a consideration of the probabilities... Helton v Allen thus established that the criminal standard of proof is inappropriate to the determination of any such fact in any civil action tried in any court in Australia where there are no statutory provisions to the contrary. That decision is binding on all courts in Australia unless and until there is a precise decision to the contrary by the Court or by the Privy Council (519 520). (citation omitted)

No matter how grave the fact which is to be found in a civil case, the mind has only to be reasonably satisfied and has not with respect to any matter in issue in such a proceeding to attain that degree of certainty which is indispensible to the support of a conviction upon a criminal charge: see Helton v Allen (521 522). (citation omitted)

54 There is no later decision of the High Court to contrary effect. The principle enunciated in Rejfek v McElroy and Helton v Allen [1940] HCA 20; (1940) 63 CLR 691 was affirmed in Neat Holdings Pty Ltd v Karajan Holdings Pty Ltd [1992] HCA 66; (1992) 110 ALR 449, where the majority (Mason CJ, Brennan, Deane & Gaudron JJ) observed:

The ordinary standard of proof required of a party who bears the onus in civil litigation in this country is proof on the balance of probabilities. That remains so even where the matter to be proved involves criminal conduct or fraud (449 450).

55 In that and other cases (notably Briginshaw v Briginshaw [1938] HCA 34; (1938) 60 CLR 336), the High Court has referred to the relevance of the gravity of the allegations made to the process of assessment properly undertaken by a trial judge. However, as the majority pointed out in Neat Holdings, while it is appropriate for a trial judge to be conscious of the gravity of the allegations made, 'it remains incumbent upon the trial judge to determine the issue by reference to the balance of probabilities' (451).

56 In the case of an administrative body or tribunal such as the committee, there is room for doubt on the question of whether it is appropriate to talk of the applicable standard of proof using the lexicon applied to court proceedings. In Minister for Immigration and Ethnic Affairs v Wu Shan Liang [1996] HCA 6; (1996) 185 CLR 259, the majority (Brennan CJ, Toohey, McHugh and Gummow JJ) observed:

Where facts are in dispute in civil litigation conducted under common law procedures, the court has to decide where, on the balance of probabilities, the truth lies as between the evidence the parties to the litigation have thought it in their respective interests to adduce at the trial. Administrative decision-making is of a different nature. A whole range of possible approaches to decision-making in the particular circumstances of the case may be correct in the sense that their adoption by a delegate would not be an error of law. The term 'balance of probabilities' played a major part in those submissions, presumably as a result of the Full Court's decision. As with the term 'evidence' as used to describe the material before the delegates, it seems to be borrowed from the universe of discourse which has civil litigation as its subject. The present context of administrative decision-making is very different and the use of such terms provides little assistance (282).

57 The context of administrative decisionmaking under consideration in Wu Shan Liang involved the delegate of the minister deciding whether he or she was satisfied that the relevant person had a genuine fear founded upon a real risk of persecution. The decisionmaking process therefore had a characteristic of subjectivity, being dependent upon the state of satisfaction of the particular decisionmaker, and futurity, requiring an assessment of the risk of persecution in the event of refoulement. It is relatively easy to see why the High Court considered discussion of decision-making by reference to the balance of probabilities to be inappropriate in respect of a decision which was subjective in character, and which required the estimation of future risks.

58 The full Federal Court relied upon the particular characteristics of the decision to be made with respect to refugee status to explain why the ordinary civil standard of proof, namely, the balance of probabilities, did not apply to the decisionmaking process in Minister for Immigration and Multicultural Affairs v Epeabaka [1999] FCA 1.

59 Decisions made by the Committee with respect to remediation of a contaminated site are quite different in character to the decisions considered in Wu Shan Liang and Epeabaka. The Committee is required to determine whether a person or persons are responsible for the remediation of a contaminated site in accordance with the provisions of pt 3 of the Act. That determination is to be made upon the basis of findings by the Committee with respect to facts relevant to the application of the provisions of the Act imposing responsibility for remediation. This aspect of the Committee's decisionmaking process is quite different in character to the estimation of future risk, and is analogous to the decisionmaking process of a court. If the Committee finds more than one person to be responsible for remediation of a site, it must apportion liability for remediation amongst the persons responsible. This aspect of the Committee's decisionmaking process requires value judgments to be made, which necessarily import an element of subjectivity. I will give further consideration to this aspect of the decisionmaking process of the Committee in the context of ground 9, but it is sufficient for present purposes to observe that the allocation of proportionate responsibility for remediation amongst those found responsible is analogous to the task of a court allocating proportionate responsibility amongst joint tortfeasors. It does not require the Committee to form any particular state of mind, such as a state of 'satisfaction', and is to that extent different in character to the decisionmaking process considered in Wu Shan Liang and the many other refugee cases.

60 However, there is an analogy between a decision of the Committee to the effect that a person is responsible for remediation of a site because of an act that constituted an offence for which the person was convicted, or contravention of a written law in force at the time the act occurred, and the decision of an assessor with respect to liability for compensation for criminal injuries pursuant to the provisions of the Criminal Injuries Compensation Act 2003 (WA), and the legislation which preceded that Act (the Criminal Injuries Compensation Act 1985 (WA)). Under that legislation, compensation may be awarded by an assessor in some circumstances, even when a person has not been convicted of an offence that caused the injuries for which compensation is claimed. A series of decisions establish that for the purposes of applying the relevant provisions of that legislation, the assessor is to determine whether or not a relevant offence was committed on the balance of probabilities - see Re Carter (1984) 4 SR (WA) 219; Sunderland v Curnack [2002] WASC 158; Bas v The Estate of Nas (Dec) [2000] WASCA 270 [11] (Pidgeon, Ipp & Anderson JJ); Re application of Ann-Maree Hanratty (1984) 14 A Crim R 36; Hasler [2009] WADC 194 [6], [11], [34] (Sleight DCJ). There is much to be said for the view that the same approach should be taken to decisions of the Committee with respect to persons responsible for the remediation of a contaminated site. However, for the purposes of this appeal, it is unnecessary to determine whether the Committee is required to make its decisions on the balance of probabilities. It is sufficient to dispose of this aspect of the appeal to conclude that there is no basis whatever for the proposition that the Committee has to be satisfied beyond reasonable doubt in relation to any of the matters which it is required to determine. BP's submission to the contrary must be rejected.

61 The proposition that there was no evidence to support the Committee's finding that BP contravened s 49(1) of the EP Act is hopeless. At the relevant time, that subsection provided:

A person who causes or allows to be caused pollution commits an offence.

62 The term 'pollution' was (and is) defined by the EP Act to mean 'direct or indirect alteration of the environment to its detriment or degradation' (among other things): EP Act, s 3A.

63 In each of its submissions to the Committee, BP accepted, clearly and unequivocally, that fuel had leaked from underground pipes situated on the site and contaminated the environment. There was in any event abundant evidence to sustain that finding from the reports and site surveys provided to the Committee. This provided ample evidence to sustain a finding that the site had been polluted as a result of the leak - indeed, any other finding would have been perverse.

64 As I have noted, BP also conceded, in each of its submissions to the Committee, that it was obliged to repair and maintain all of the fixtures and fittings on site, including the underground pipe work. The lease imposing that obligation upon BP was before the Committee. BP's concession that the contamination of the site came about as a result of leakage of fuel from underground pipes on the site which it was obliged to repair and maintain, a concession amply justified by the evidence before the Committee, was quite sufficient to sustain the conclusion that BP caused pollution at the site by failing to repair and maintain the pipe work. Any other conclusion would have been perverse.

65 The written and oral submissions advanced in support of this ground were difficult to comprehend (ts 9, 10, 25, 26). Reference was made to causation, in terms which suggested that there was no evidence to enable the Committee to conclude that BP's failure to repair and maintain the anaconda joint caused the contamination of the site. However, the 1996 report referred to a 'weeping anaconda', and the 1997 report noted that the pipe integrity test showed the pipe work to be sound after the anaconda joint had been replaced. In those circumstances, and as a matter of common sense, it is difficult to see how any causation issue arose on the evidence before the Committee.

66 At some points in the oral argument, it appeared that counsel was endeavouring to draw a distinction between maintenance on the one hand and repairs on the other, or to assert that the Committee should have concluded that the anaconda joint failed due to 'fair wear and tear' with the result that BP was not obliged to repair or maintain it. However, the terms of the lease, and the concession made by BP are clear, and include the obligation to both repair and maintain. If, as the Committee found, on the basis of abundant evidence before it, that the anaconda joint had failed and was allowing fuel to leak into the soil, under the lease it was BP's obligation to repair the valve so as to prevent further leakage. That is in fact what BP caused to be done. There was no evidence to suggest that the valve failed as a result of 'fair wear and tear' and in any case, this was a question of fact for the Committee. At all events, it is sufficient to dispose of this ground of appeal to observe that there was at least some evidence upon which the Committee could have found that BP contravened s 49(1) of the EP Act. Once that is established, the question of whether or not the Committee should have so found is not a question of law, and therefore not a question which falls within the appellate jurisdiction of this court.

67 For these reasons, there is no substance in any of the propositions contained within ground 1.

68 Ground 2 asserts that the Committee erred by relying upon BP's contravention of the head lease, and the equipment loan agreement, when neither the lease, nor the agreement had been 'given or made under a written law' within the meaning of that expression in s 25(5)(b)(ii) of the Act.

69 The first question which must be addressed is whether the Committee did in fact rely upon s 25(5)(b)(ii) of the Act for its conclusion that BP had caused or contributed to contamination of the site by an act that was done without lawful authority.

70 Before addressing that question, there are a number of observations usefully made concerning s 25(5). First, the definition of 'an act that was done without lawful authority' is an inclusive definition, provided 'without limiting the meaning of the expression'.

71 Second, the subsection provides three alternative routes by which it may be concluded that an act was done without lawful authority. The first is that the act constituted an offence for which the person was convicted. There is no suggestion that this provision has any application to this case. The second is that the act contravened a written law in force at the time the act occurred. That is the means by which it was open to the Committee to conclude that BP's acts in contravention of s 49(1) of the EP Act were acts that were done without lawful authority. The third route provided by s 25(5) is an act that contravened 'any contract ... lease ... (etc) that was given or made under a written law in force at the time the act occurred'. Ground 2 depends upon the conclusion that the Committee relied upon this provision to find that BP had caused or contributed to contamination of the site by an act done without lawful authority.

72 The relevant portion of each of the Committee's reasons for decision in respect of each of periods 6, 7 and 8 is in substantially identical terms as follows:

During the ... period, under the former section 49(1) of the Environmental Protection Act 1986 (EP Act) which was in force during the ... period, all parties were required to not cause pollution.

Although no lease for the ... period has been provided, lease arrangements would have been similar to the lease agreement between George Hrga and BP Australia Ltd ...

During the ... period, as lessee of the site BP Australia Ltd under the terms of the lease would have been obliged to maintain the lessor's fixtures, fittings, installations and facilities and the lessee's fixtures, fittings and equipment.

The act by BP Australia of failing to maintain the anaconda joint was an act that was done without lawful authority, in that it caused pollution, in contravention of former section 49(1) of the EP Act. It would also have been in contravention of the terms of the lease.

Although no agreement for the loan or dispensing equipment for the ... period has been provided, loan arrangements would have been similar to the loan agreement between George Hrga, Mr and Mrs Cerinich, and BP Australia Ltd.

During the ... period, as the owners of loaned pumps at the site, BP Australia Ltd under the terms of the loan would have been obliged to maintain the dispensing equipment and Mr and Mrs Eldesouki, as 'borrowers' would have been precluded from performing 'repair, alteration, addition or attachments to the equipment'.

73 The sentence which contains the Committee's finding that BP's failure to maintain the anaconda joint was an act that was done without lawful authority refers only to contravention of s 49(1) of the EP Act. Although that sentence is immediately followed by a reference to contravention of the terms of the lease, and later by a reference to BP's obligations under the equipment loan agreement, the Committee's reasons do not directly link either of those agreements to the conclusion that BP's acts were acts done without lawful authority. Nor is there any reference to either of those agreements having been made under a written law, which would be expected if the Committee was indeed relying upon s 25(5)(b)(ii) of the Act. By contrast, the Committee's reasons clearly connect BP's contravention of s 49(1) of the EP Act with the Committee's conclusion that BP caused or contributed to contamination of the site by an act done without lawful authority.

74 The better view of the Committee's reasons is that the only basis upon which it found that BP had caused or contributed to contamination of the site by an act done without lawful authority was BP's contravention of s 49(1) of the EP Act.

75 Nevertheless, BP's obligation to maintain the anaconda joint arising under each of the lease and the equipment loan agreement was obviously relevant to the Committee's conclusion that BP had contravened s 49 of the EP Act. Where, as in this case, a number of persons and entities are interested in the operation of a site, identification of the person or persons who 'caused pollution' in contravention of s 49(1) of the EP Act, may well turn upon the identification of the person or persons who had assumed the responsibility of preventing pollution from occurring. Agreements entered into between the parties with an interest in the operations conducted on the site are likely to be very relevant to that issue. The Committee's finding that BP was obliged to repair and maintain the anaconda joint under both the lease and the equipment loan agreement provided a basis for concluding that BP had caused pollution by failing to discharge those responsibilities, and had thereby contravened s 49(1) of the EP Act. This process of reasoning is quite separate and distinct from a conclusion that BP had caused or contributed to contamination of the site by an act done without lawful authority merely because it was in breach of a lease or contract with a third party.

76 It follows that ground 2 must fail, because the Committee did not in fact rely upon the provisions of s 25(5)(b)(ii) of the Act for its determination. But even if it had, ground 2 would still fail, because it is clear that the Committee relied upon its finding that BP had contravened s 49(1) of the EP Act for its conclusion that BP had caused or contributed to contamination of the site by an act done without lawful authority. It follows that any reliance placed by the Committee upon s 25(5)(b)(ii) was not essential to its ultimate conclusion, with the result that even if the Committee had erred in its construction of that provision, its decision would nevertheless be affirmed unless its conclusion with respect to contravention of the EP Act was also successfully impugned.

77 It is therefore unnecessary to resolve the question of whether an act of a person which causes or contributes to the contamination of a site before the commencement of the Act can be said to be an act that was done without lawful authority merely because the act contravened a lease or agreement between that person and another, not being a lease or agreement given or made under a written law in force at the time the act occurred. It would be preferable to leave resolution of that question to a case in which it is necessary. However, out of deference to the arguments advanced on behalf of the intervenors, I will express some tentative views on that topic.

78 The central question is the proper construction to be given to the expression 'an act that was done without lawful authority' in s 25(3) of the Act. Because the definition of that expression in s 25(5) of the Act is not exhaustive, it follows that s 25(3) can properly be construed as encompassing acts that fall outside the scope of s 25(5).

79 The intervenors submit, and I accept, that the expression should be construed as involving some contravention of the law, rather than an act done in the absence of some positive authorisation by or under law. That construction of the section is supported by the observation that s 25(3) of the Act imposes liability upon persons for acts or omissions which occurred prior to the commencement of the Act. To that extent, the provision has the character of retrospective operation. That character suggests it is more likely that Parliament intended the provision would have that effect only when the relevant act or omission was in contravention of a law, rather than in all cases in which there was an absence of positive legal authority. That construction of the section is supported by the relevant debates in Parliament: Parliamentary Debates, Western Australia, Legislative Council, 22 October 2003, 123879.

80 That construction of the expression is also consistent with the inference to be drawn from the terms of s 25(5) of the Act. Although the definitions provided in that section are not said to be exhaustive, all have the characteristic of contravention of a law or of agreements made under a law, and none include a mere absence of positive authority.

81 The intervenors submit that an act can be done without lawful authority within the meaning of s 25(3) of the Act if it is done in contravention of an obligation arising under civil law. I can see the force of that argument where the obligation is recognised by the law of tort, not least because the law of tort imposes obligations upon all by reference to common law standards and duties, which in turn reflect community standards or norms of conduct. So where the act which carries or contributes to the contamination of a site constitutes the tort of nuisance, or trespass, it is fairly arguable that the act is properly described as 'an act that was done without lawful authority'.

82 However, the argument seems to me to be significantly weaker when the civil obligation arises under a contract (or lease) between private parties. The provisions of such contracts or leases usually reflect the idiosyncratic negotiating positions of the parties, rather than any standards or duties recognised at common law or any community standards or norms of conduct.

83 I am tentatively inclined to the view that the same process of reasoning which leads to the conclusion that an act will only be done without lawful authority for the purposes of s 25(3) if it is in contravention of a law, supports the conclusion that mere breach of a contractual obligation would not, of itself, bring the act or omission within the scope of the section. Those arguments are the retrospective character of the section and the fact that each of the definitions contained within s 25(5) has the characteristic of contravention of a written law, or contravention of an agreement made under the authority of a written law.

84 Further, if, as the intervenors submit, breach of an obligation arising under a purely private contract or agreement brings an act or omission within s 25(3), as an act done without lawful authority, the inclusion within s 25(5) of a class of act done in contravention of a lease or other agreement given or made under a written law would be entirely otiose and redundant. This suggests that the intention of Parliament was that breach of an obligation arising under an agreement or lease would only come within the scope of s 25(3) if the agreement or lease was given or made under a written law, and not otherwise.

85 This is, of course, not to say that civil obligations arising from agreements are irrelevant to the question of whether an act was done without lawful authority under s 25(3) of the Act. This case provides an example of the way in which obligations arising under agreements or leases can support a conclusion that an act causing or contributing to contamination of a site was an act (or omission) done without lawful authority because it caused pollution contrary to s 49(1) of the EP Act.

86 However, I repeat that it is unnecessary for me to resolve this interesting question of construction for the purposes of this appeal, and its final resolution should properly await a case in which it is critical to the disposition of the case.

87 This ground asserts that there was no evidence that the anaconda joint was part of the dispensing equipment, and therefore came within BP's responsibility of repair and maintenance under the equipment loan agreement. The ground is pointless. As I have noted several times, BP accepted that it was obliged to repair and maintain all underground pipe work, including the anaconda joint, by the terms of its lease, and the lease having that effect was in evidence before the Committee. Whether BP was under a similar obligation by reason of the equipment loan agreement was not an essential component of the Committee's reasoning. Accordingly, the decision of the Committee would be affirmed even if it was in error with respect to the operation and effect of the equipment loan agreement.

88 But in any case, the ground is without substance. As I have noted, the Committee is not bound by the rules of evidence and can conduct its enquiries (and therefore inform itself) as it thinks fit. Persons can only be appointed to the Committee if, in the opinion of the Minister, they have 'suitable expertise to make decisions for the purposes of [the] Act' (s 33(2) of the Act). It is a notorious fact that many of the contaminated sites to be dealt with by the Committee will be sites which have been used as service stations. It is therefore to be expected that members of the Committee will either have or gain expertise in the manner of operation of service stations and can bring that expertise to bear in the exercise of their functions.

89 Literally speaking, an Anaconda is of course a large snake. When used to describe a form of pipe it is reasonable to infer, as the Committee found, that it describes a pipe with a serpentine and flexible configuration. It is perfectly reasonable to infer, even in the absence of expertise, that such a pipe is most likely to be used to connect dispensing equipment to in situ rigid pipes which are connected to the underground tanks. That is what the Committee found. It was also open to the Committee to find that the anaconda joint formed part of the dispensing equipment in that it connected the pumps to the fuel source.

90 Ground 4 borders on the incomprehensible. It appears to repeat propositions advanced in support of ground 1(c) to the effect that there was no evidence to sustain the conclusion that repairing or maintaining the anaconda joint would have prevented the leak. For the reasons I have already given, there was ample evidence to sustain the Committee's finding that repair and maintenance of the valve would have prevented the leak.

91 Ground 5 alleges that the Committee failed to have regard to a relevant consideration which it was required to take into account, namely the obligations of Mr and Mrs Eldesouki with respect to repair and maintenance of equipment under the terms of their sublease and franchise agreements with BP.

92 An allegation of failure to take into account a relevant consideration will only give rise to a question of law if, as a matter of construction of the statute, the decisionmaker was bound to take a matter into account as a condition of the exercise of the powers conferred by the statute (see Minister for Aboriginal Affairs v PekoWallsend Ltd [1986] HCA 40; (1986) 162 CLR 24, 39 40 (Mason J)). The ground depends upon it being established that the decisionmaker failed to take any account of the relevant mandatory consideration - that is, that the consideration was ignored. Where, as in this case, an appeal lies only on a question of law, a ground which asserts, in substance, that a decisionmaker failed to give proper weight to a mandatory consideration, or to act upon it as the appellant would assert, does not give rise to a question of law falling within the jurisdiction of the court: see Minister for Aboriginal Affairs v PekoWallsend Ltd, 41 (Mason J). A question of law may arise if it is alleged that the failure to give weight to a relevant consideration has resulted in a decision that is manifestly unreasonable in the sense described in Associated Provincial Picture Houses Ltd v Wednesbury Corporation [1947] EWCA Civ 1; [1948] 1 KB 223, 230 (as explained by Mason J in Peko-Wallsend); see also Re Minister for Immigration and Multicultural and Indigenous Affairs; Ex Parte Palme [2003] HCA 56; (2003) 216 CLR 212 [30] (Gleeson CJ, Gummow & Heydon JJ). However, BP makes no allegation of that kind in this case.

93 This ground is, in substance, a complaint that the Committee failed to give proper weight to a relevant consideration. In essence it asserts that BP is aggrieved because the Committee did not apportion greater responsibility to Mr and Mrs Eldesouki because not only were they the operators of the site, but they had obligations of maintenance of the pipe work under the sublease and franchise agreements. In substance, this amounts to a challenge to the merits of the Committee's decision, rather than an assertion that the Committee erred on a question of law.

94 It is to be remembered that in each of periods 6, 7 and 8 the Committee apportioned 50% of the responsibility for contamination caused during those periods to BP, and 50% to Mr and Mrs Eldesouki. There is no suggestion that this allocation of responsibility was irrational or so unreasonable as to fall outside the range of allocations reasonably open to the Committee. Accordingly this is one of those grounds which, although expressed as a ground of law, is in substance a challenge to the Committee's decision on its merits.

95 The ground is in any event based upon a dubious premise. Clause 9 of the sublease between BP and Mr and Mrs Eldesouki deals with maintenance and repairs. The obligation of repair and maintenance imposed upon the sublessees by that clause does not apply to the equipment listed in the Fourth Schedule to the sublease (cl 9(2)). The Fourth Schedule lists the dispensing pumps and the tanks. It is by no means clear that the proper construction of the sublease requires the sublessees to repair and maintain the pipes which connect the pumps to the tanks, given that the sublessees have no obligations to repair or maintain either the pumps or the tanks. To the contrary, a construction of the lease which would treat the pipes connecting the pumps to the tanks in the same way as the pumps and the tanks in relation to repair and maintenance would seem more reasonable.

96 The ground also refers to the franchise agreement between BP and Mr and Mrs Eldesouki. However, that agreement contains no provisions with respect to repair and maintenance of the pipes. The only relevant provision is an obligation to report losses of fuel (cl 7), which would presumably be construed as attaching only to losses of fuel known to the franchisees. There is no evidence to sustain a finding that Mr and Mrs Eldesouki were aware that fuel was being lost, or that they were in breach of the franchise agreement in any respect.

97 For these various reasons, there is no substance in ground 5.

98 Ground 6 asserts that the Committee's findings that:

(a) BP was obliged to maintain the anaconda joint pursuant to its lease of the site;

(b) the anaconda joint was part of the dispensing equipment; and

(c) the anaconda joint was capable of being maintained and the leak was caused by the failure to maintain that joint,

are findings upon which the jurisdiction of the Committee depended, and were made wrongly.

99 This ground is utterly misconceived. It presupposes that any finding of fact made by a decisionmaker which is critical to his or her decision is a fact upon which the decisionmaker's jurisdiction depends. That is plainly wrong. A jurisdictional fact is a fact the objective existence of which is either a matter upon which the jurisdiction of the decisionmaker depends, or which, if it exists, constrains the jurisdiction of the decisionmaker (Corporation of the City of Enfield v Development Assessment Commission [2000] HCA 5; (2000) 199 CLR 135 [28] (Gleeson CJ, Gummow, Kirby & Hayne JJ)). Because the objective existence (or nonexistence) of the fact is a condition upon which the jurisdiction of the decisionmaker depends, a court can determine whether or not the fact exists for the purposes of determining whether or not the decisionmaker has exceeded his or her jurisdiction. In that respect, the fact is in a fundamentally different category to those facts which are found by decisionmakers in the course of the exercise of their jurisdiction. Because the existence or nonexistence of a fact of the latter kind is not a matter upon which the jurisdiction of the decisionmaker depends, it is not a matter susceptible of review by courts by way of judicial review based on jurisdictional error, or on an appeal on a question of law (see Corporation of the City of Enfield v Development Assessment Commission).

100 The three facts specified in ground 6 are plainly facts which were found by the Committee in the exercise of its jurisdiction. Although some of the facts were steps on the critical path to the Committee's conclusion, this does not mean that they are facts upon which the jurisdiction of the Committee depended. To the contrary, probably the only objective fact upon which the jurisdiction of the Committee depended was the fact of classification of the site by the CEO as being a site which required remediation. In this context I distinguish jurisdictional facts from procedural obligations which may themselves be a condition of the valid exercise of jurisdiction (such as, perhaps, the service of notice under s 37 of the Act prior to the making of a determination).

101 In any case, the three facts identified in ground 6 were plainly established on the evidence before the Committee, essentially for the reasons I have already given. BP conceded that it was obliged to repair and maintain all fixtures and fittings, which includes the anaconda joint, under the terms of its lease, and there is no doubt that the anaconda joint was capable of being maintained and repaired (as in fact it was in 1997) or that the leak was caused by the failure to repair and maintain the joint. The finding that the anaconda was part of the dispensing equipment, and therefore fell within the terms of the equipment loan agreement was not on the critical path to the Committee's conclusion but is in any event sustained by the inferences properly drawn as to its close proximity to the fuel pumps.

102 Ground 7 asserts that the Committee's finding that the leak from the anaconda joint commenced on 4 June 1992 was made without any evidence, or alternatively, was irrational. It is of course necessary to maintain the distinction between a ground which asserts that there was no evidence to sustain a finding of fact, and a ground which challenges the finding made based on the weight of the evidence. Only a ground of the former kind raises a question of law falling within the appellate jurisdiction of the court.

103 I have set out above (at [41]) the reasons given by the Committee for concluding that the leak was likely to have occurred from 4 June 1992 at or about the time new pumps were installed. Those reasons take account of the likely rate of the leak (given that it was described in 1996 as a 'weeping anaconda'), the large plume of contamination under the surface, the relatively flat hydraulic gradient, and the speed at which the hydrocarbon contaminated ground water had travelled. A documentary reference has been provided by the Committee in relation to each of these matters. The Committee has therefore specified the evidence upon which it relied for its conclusion. The proposition that there was no such evidence is without foundation, as is the proposition that the Committee's conclusion was irrational (assuming that to be an allegation of unreasonableness, in the Wednesbury sense).

105 Ground 8 asserts that the Committee denied BP natural justice because of variations between the terms of its final decision, and the tentative decision of which notice was given pursuant to s 37 of the Act.

106 Three general points may be made in relation to this ground. First, the question of whether a decisionmaker denied natural justice to a person affected by the decision can be a question of law (Clements v Independent Indigenous Advisory Committee [2003] FCAFC 143; (2003) 131 FCR 28 [8] (Gray CJ & North J)).

107 Second, BP does not assert that the Committee failed to comply with s 37 of the Act, or that the notice that was given pursuant to that section was deficient in any respect.

108 Third, the ground and the submissions advanced in support of the ground proceed on the false assumption that merely identifying differences between the terms of the notice given under s 37 of the Act and the final decision of the Committee will be sufficient to establish a denial of natural justice or, as I prefer, procedural fairness. However, the hearing rule (being the component of procedural fairness relevant to this ground) is only breached if a party affected by the decision is denied a fair opportunity to put relevant evidence or submissions before the decisionmaker prior to the decision being made.

109 Generally speaking, a fair opportunity to put relevant evidence and submissions before the decisionmaker will require that a party likely to be affected by the decision be made aware of the issues which the decisionmaker considers to be critical to the decision. The following description of that entitlement by Northrop, Miles and French JJ in Commissioner for Australian Capital Territory Revenue v Alphaone Pty Ltd [1994] FCA 1074; (1994) 49 FCR 576 has been approved by the High Court on a number of occasions (see Minister for Immigration and Multicultural and Indigenous Affairs; Ex parte Palme [2003] HCA 56; (2003) 216 CLR 212, [22] (Gleeson CJ, Gummow & Heydon JJ); SZBEL v Minister for Immigration and Multicultural and Indigenous Affairs [2006] HCA 63; (2006) 228 CLR 152, 161 166; Minister for Immigration and Citizenship v SZGUR [2011] HCA 1; (2011) 214 CLR 594 [9] (French CJ & Kiefel J):

It also extends to require the decisionmaker to identify to the person affected any issue critical to the decision which is not apparent from its nature or the terms of the statute under which it is made. The decisionmaker is required to advise of any adverse conclusion which has been arrived at which would not obviously be open on the known material. Subject to these qualifications, however, a decisionmaker is not obliged to expose his or her mental processes or provisional views to comment before making the decision in question (591 592).

110 Section 37 of the Act modifies the common law requirements of procedural fairness and imposes upon the Committee a stricter obligation with respect to the provision of notice to parties likely to be affected by the decision of the Committee than that which would otherwise apply. However, as I have noted, BP does not assert that the Committee failed to comply with s 37 of the Act. Accordingly, this ground of appeal must be assessed by reference to the common law requirements of procedural fairness and, in particular, whether the course taken by the Committee denied BP a fair opportunity to put relevant evidence and submissions before the Committee.

111 The ground of appeal identifies a number of differences between the terms of the notice given under s 37 of the Act and the Committee's final decision. During oral argument, counsel for BP was asked to specify which of those differences identified a matter or subject upon which BP was denied a fair opportunity to place relevant evidence or submissions before the Committee. Counsel referred only to the change in the time at which the Committee considered the new dispensing equipment had been installed, which was the date from which the Committee considered the leak had commenced - namely, the change from 25 December 1992 to 4 June 1992 (ts 38).

112 The notice given by the Committee pursuant to s 37 of the Act made it abundantly clear that the Committee was tentatively disposed to find that the leak commenced at the time the new dispensing equipment was installed. The notice given by the Committee under s 37 of the Act also made clear that the Committee lacked precise information as to the date upon which the new dispensing equipment was installed. BP was well aware of that fact because its solicitors had corresponded with the Committee on that precise topic. The notice given by the Committee pursuant to s 37 of the Act indicated that in the absence of better information, the Committee reasonably suspected the date of installation, and therefore the date of commencement of the leak, to have been 25 December 1992. BP was well aware of that tentative view, which was contested in its submission of 23 December 2010. BP submitted that there was evidence that the leak did not occur until some time after 30 October 1993, and tendered evidence in support of that submission, being the report of a site inspection which took place on 29 October 1993. However, as I have noted, the site inspection appears to have been a somewhat superficial inspection of only the equipment that was above ground and visible.

113 The assertion that BP was denied a fair opportunity to put evidence or submissions before the Committee with respect to the question of when the leakage of fuel commenced, and which BP well knew to be a live issue, is contrary to the facts and must be rejected.

114 Although counsel for BP did not press any of the other specific matters identified in ground 8, for the sake of completeness I will address them. The first concerns the Committee's reference to underground pipe work in the notice given under s 37, whereas its final decision was based upon the failure of the anaconda joint. As I have already noted, this distinction is not material, given that BP accepted that under its lease it was responsible for repairing and maintaining all equipment on site. In any event, BP was well aware of the evidence before the Committee which suggested that the leak came from the anaconda joint or valve.

115 The second matter raised in the ground concerns the Committee's finding that the anaconda joint was part of the dispensing equipment and therefore came within the equipment which BP was obliged to repair and maintain pursuant to the equipment loan agreement. However, as I have already pointed out, the Committee's decision did not depend upon that finding, given the undisputed finding that BP was obliged to repair and maintain the equipment under its lease. In any event, BP was well aware of the Committee's tentative view that the equipment loan agreement applied to the underground pipework that had failed, and included a submission denying that proposition in its submission of 23 December 2010.

116 The third matter relied upon in the ground is the finding in the Committee's final decision that the leak was a slow leak, which was not a matter specifically referred in the notice given under s 37 of the Act. However, that finding has no significance of its own, but was part of the process of reasoning which led to the Committee's conclusion as to the date upon which the leak most likely commenced - a topic upon which BP was given every opportunity to place submissions and evidence before the Committee. Further and in any event, BP was aware that the Committee had before it a report which had described the anaconda joint as 'weeping', a term apt to describe a slow leak, given that a 'weep' can mean exuding water or liquid: Macquarie Concise Dictionary (5th ed, 2009).

117 Fourth, BP points to the Committee's finding that the anaconda joint was capable of being maintained. This part of the ground is difficult to understand given that it is patently obviously that any item of equipment is capable of being maintained or repaired so as to perform its function. If this item is meant to be a reference to the change in terminology between underground pipe work generally and the anaconda joint in particular, it must be rejected for the reasons I have given above.

118 The last matter raised in this ground concerns the change in allocation of responsibility between the notice given under s 37 and the Committee's final determination. However, the notice given by the Committee made it abundantly clear that it was proposing to consider the allocation of responsibility between the various parties it tentatively considered to have caused or contributed to the contamination of the site, and submissions were invited from the parties as to those tentative allocations. BP responded to the invitation and submitted that BP should bear no allocation of responsibility. The fact that the Committee decided to alter its tentative allocation of responsibilities in its final decision provides no basis for an assertion that BP was denied a fair opportunity to put evidence and submissions before the Committee on the topic of the relative responsibilities of the parties who had caused or contributed to the contamination of the site.

119 For these various reasons, ground 8 must be rejected.

120 Ground 9 asserts that the reasons given by the Committee were inadequate. The ground is not augmented by any particulars or by any meaningful indication of the way in which the reasons were said to be inadequate. Those matters must be found within the submissions provided in support of the ground.

121 As I have noted, s 39 of the Act requires the Committee to give notice of its decision as to responsibility for remediation in writing to each person who the Committee has decided is responsible for remediation. The section further provides that the notice must specify the reasons for the decision.

122 The question of whether or not the Committee has complied with the statutory obligation imposed by s 39 of the Act is a question of law. However, the question of whether compliance with that obligation is a condition of the valid exercise of the Committee's jurisdiction is a different and more difficult question - see Sieffert v Prisoners Review Board [2011] WASCA 148 [158] [179]. If, as a matter of statutory construction, compliance with the obligation to provide reasons is a condition of the exercise of jurisdiction, failure to provide reasons will necessarily result in the decision being set aside for want of jurisdiction. However, if compliance with the obligation to provide reasons is not a condition of the exercise of jurisdiction, on an appeal on a question of law it will be for the court to determine the consequences which should flow from failure to comply with the obligation to provide reasons. In some cases, the departure from the obligation to provide reasons may be so gross as to compel the conclusion that the decisionmaker has not properly exercised the jurisdiction conferred, with the result that the decision will be set aside. In other cases where the extent of noncompliance is less egregious, the appropriate course may be to remit the matter to the decisionmaker for further consideration. In other cases where the extent of noncompliance with the obligation to provide reasons is of a minor nature, and has not impeded the exercise of any right of appeal from the decision or given rise to any inference that the decisionmaker has not validly exercised the jurisdiction conferred, it may be appropriate to affirm the decision notwithstanding the failure of the decisionmaker to provide adequate reasons for the decision.

123 The principles governing the content required of the statement of reasons in order to comply with the obligation imposed by s 39 of the Act will be informed by:

(a) the general principles relating to the requisite content of a statement of reasons;

(b) the fact that the Committee is an administrative decisionmaker comprising people with expertise in the area covered by the Act. Although the panel of names from which a Committee is to be selected by the Minister must contain the name of at least one legal practitioner, the Act does not require the minister to select a legal practitioner to serve on the Committee; and

(c) the fact that there is a right of appeal from the decision of the Committee, on a question of law only.

124 I have set out my view of the principles governing the requisite content of reasons in similar circumstances - namely, a circumstance in which the decisionmaker is a specialist administrative committee from which an appeal lies to this court on a question of law, in Hancock v Executive Director of Public Health [2008] WASC 224 [65] [74]. No point would be served by restating those principles in these reasons. It is sufficient to observe that an appellate court must read the reasons under challenge as a whole and fairly, taking account of the decisionmaker's lack of legal expertise, without applying a 'fine appellate toothcomb' (Minister for Immigration and Ethnic Affairs v Wu Shan Liang, 291 (Kirby J)), or 'with an eye keenly attuned to the perception of error' (Collector of Customs v Pressure Tankers Pty Ltd and Pozzolanic Enterprises Pty Ltd [1993] FCA 322; (1993) 43 FCR 280, 287 (Neaves, French & Cooper JJ)).

125 The question of whether or not the reasons provided by the Committee in any particular case are adequate will, of course, turn upon the particular facts and circumstances of that case. Those circumstances will include the communications between the Committee and the party affected by the Committee's decision prior to delivery of the decision. Put another way, the reasons given by the Committee under s 39 of the Act are not to be construed out of context and in isolation, but against the background of the prior dealings between the Committee and the persons affected by its decision, as that is how they will be viewed by the persons to whom the reason are given.

126 It is now necessary to assess BP's allegations of deficiency in the reasons provided by the Committee against these general principles. Because the ground of appeal is devoid of meaningful content, it is necessary to go to the written and oral submissions for that purpose.

127 BP asserts that the Committee's reasons are deficient by not revealing whether or not it had applied the criminal standard of proof to its determination that BP had contravened s 49(1) of the EP Act. Given my conclusion that the Committee was not required to apply that standard of proof, this complaint must be rejected.

128 Next, BP complains that the Committee's reasons do not make clear whether or not it was relying upon the equipment loan agreement as a basis for concluding that BP had contravened s 49(1) of the EP Act. There is no substance in this complaint. The reasons clearly state that the Committee relied upon the fact that BP was obliged to repair and maintain the anaconda joint pursuant to both the lease agreement and the equipment loan agreement for the purpose of concluding that BP had caused pollution contrary to s 49(1) of the EP Act.

129 Next, BP complains that the Committee gave no reasons for its finding that the anaconda was part of the dispensing equipment. However, the Committee's reasons clearly state that the anaconda is a flexible pipe which forms part of the dispensing equipment and connects the dispensing equipment to the underground pipe work. The proposition that the Committee was required to go further and say precisely why it considered the anaconda joint to be part of the dispensing equipment would impose a quite unrealistic and unreasonable standard of detail upon decisions of this kind. Further and in any event, as I have noted, this complaint is irrelevant given BP's concession that it was obliged to repair and maintain all pipe work on site under the terms of its lease.

130 Next, BP complains that the Committee gave no reasons for its finding that the leak in the anaconda joint was a slow leak. Once again, this complaint applies a quite unrealistic and unreasonable standard of detail to the content of the reasons required to be given by the Committee. But in any event, the reason is clear enough from the terms of the Committee's decision which refers to the report describing the 'weeping anaconda'.

131 Next, BP complains that no reasons were given for the finding that the leak commenced on 4 June 1992 or coincided with the installation of the new dispensing equipment. This assertion is without foundation. I have already set out the reasons given by the Committee for its conclusion as to the date of installation of the new equipment. A fair reading of the Committee's reasons as a whole, including its finding that the anaconda joint was part of the dispensing equipment and connected the above ground pumps to the underground pipes, and its reference to the reports which describe a 'weeping anaconda' and which later reported that replacement of an anaconda valve resulted in a satisfactory pipe integrity test, clearly indicate that the Committee was of the view that the problem with the anaconda joint was associated with and dated from the installation of the new fuel pumps.

132 Next, BP complains that the reasons did not 'state how the anaconda joint was purportedly capable of being maintained, how such maintenance was capable of being undertaken and how any such maintenance would have prevented the leak'. I have already referred to the difficulty of comprehending BP's assertions on this topic. There is no doubt that the anaconda joint was leaking. Equally there was no doubt that it was capable of being repaired, as in fact it previously had been. There is no relevant distinction between repairs and maintenance, as BP was obliged to perform both, as it conceded. The Committee's obligations to provide reasons do not extend to the enunciation of the blindingly obvious.

133 Next, BP complain that the Committee failed to provide adequate reasons as to how it allocated responsibility for remediation of the site to the contamination that occurred between the sixth to eighth periods inclusive, as a proportion of the total responsibility for remediation. The Committee's reasons set out its detailed findings of fact in respect of each period during which contamination of the site occurred. Those findings include findings with respect to the relative responsibility of those who caused or contributed to contamination of the site during each period. BP apparently makes no complaint with respect to that portion of the Committee's reasons, but complains that the reasons do not adequately identify how the Committee concluded that 42% of the responsibility for remediation of the site should be allocated to the sixth period, 2% to the seventh period, and 28% to the eighth period.

134 The Committee's findings in respect of each period set out the length of each period, the source of contamination during that period, and the extent of the contamination. The process of allocating responsibility for remediation amongst those who have caused or contributed to contamination of a site is necessarily a process of value judgment based upon findings of fact as to the relative extent to which each party caused or contributed to the contamination of the site. That process is clearly revealed by the reasons given by the Committee in this case. It is difficult, if not impossible, to see how the component of the process which involves a value judgment based upon the findings of fact could be elucidated any more fully than was done in this case.

135 The function of the Committee in allocating proportionate responsibility for remediation amongst those who have caused or contributed to contamination of the site bears some similarity to the task of a court allocating proportionate responsibility amongst joint tortfeasors, in that in each case, a value judgment must be made based upon relative culpability and contribution to the loss: see Law Reform (Contributory Negligence and Tortfeasors' Contribution) Act 1947 (WA), s 7(2); Podrebersek v Australian Iron and Steel Pty Ltd [1985] HCA 34; (1985) 59 ALR 529, 532; Fremantle Ports v P & O Ports Ltd [2008] WASCA 126, [46] (McLure JA); Fugro Spatial Solutions Pty Ltd v Cifuentes [2011] WASCA 102 [3] (Martin CJ), [187] (Mazza J); Parlin Pty Ltd v Choiceone Pty Ltd [2012] WASCA 19 [32] (Newnes JA), [69] (Murphy JA).

136 While a court allocating liability amongst joint tortfeasors is required to set out the findings of fact upon which the allocation of responsibility is made, it is not required, nor is it the practice to enunciate why a particular percentage of responsibility was allocated to a tortfeasor, as compared to some other percentage.

137 It is, however, necessary and appropriate for the court to identify the considerations bearing upon culpability and contribution to loss which have been taken into account for the purposes of making the apportionment. Even where a court fails in that responsibility, the decision on apportionment will not be set aside unless it is so unreasonable or plainly unjust as to give rise to an inference of error. In Oxley County Council v Macdonald [1999] NSWCA 126, the trial judge did not give reasons for apportionment but the apportionment was upheld as it was not unreasonable or plainly unjust. That is because the process of value judgment does not admit of mathematical precision; rather, as set out by the High Court in Podrebersek, a decision on apportionment is:

... a finding upon a 'question not of principle or of positive findings of fact or law, but of proportion, of balance and relative emphasis, and of weighing different considerations. It involves an individual choice or discretion, as to which there may well be differences of opinion by different minds': British Fame (Owners) v MacGregor (Owners) [1943] AC 197 at 201. Such a finding, if made by a judge, is not lightly reviewed (532).

(See also Pennington v Norris [1956] HCA 26; (1956) 96 CLR 10, 16; Manly Council v Byrne [2004] NSWCA 123 [103] [105]).

138 In this case, the Committee has set out the findings of fact in respect of each period during which contamination occurred. It has obviously applied its expertise to the process of value judgment necessarily involved in assessing the extent to which the contamination occurring during each period has contributed to the need to remediate the site. It may have been preferable if the Committee had provided some indication of the factors which it took into account in allocating responsibility for remediation between the various time periods during which contamination occurred. However, the Committee's findings as to the periods during which contamination occurred, and the general extent and nature of the contamination during each period, provide the parties affected with sufficient information to comprehend the basis for the Committee's apportionment. At all events, it is not suggested by BP, nor could it be concluded, that the allocation of responsibility as between different time periods is so unreasonable or so unjust as to manifest error.

139 Next, BP complains that the Committee did not give reasons why the fair wear and tear exception to BP's repair and maintenance obligation under its lease did not apply to absolve BP from responsibility for the anaconda joint. However, as I have already noted, there was no evidence whatever to suggest that the anaconda joint failed by reason of fair wear and tear. In any event, the Committee's reasons as a whole clearly reveal that it was of the view that the defect in the anaconda joint was associated with the installation of the new fuel pumps, and had nothing to do with fair wear and tear.

140 Finally, BP asserts that the Committee's reasons were deficient because they failed to address the question of Mr and Mrs Eldesouki's liability to repair and maintain the anaconda joint under their sublease and franchise agreements with BP. However, this complaint must be rejected for the reasons I have given in relation to ground 5 above, including most significantly the fact that it was open to the Committee to find that Mr and Mrs Eldesouki had no such obligation under either the sublease or franchise agreement, and in any event, the Committee allocated equal responsibility to Mr and Mrs Eldesouki and BP for the contamination caused during periods 6, 7 and 8.

141 For these reasons, BP's assertion that the Committee failed to provide adequate reasons for its decision must be rejected.

143 BP has failed to identify any question of law upon which the Committee erred. BP's appeal must be dismissed and the decision of the Committee affirmed.