Harm to the environment
28In the trial judgment I found that 5,639.31 tonnes of liquid waste had been transported by Shannongrove to Marylands and there injected into the soil at the direction of the farm manager. I also described the manner in which that liquid waste was generated. In short, it is the liquid waste product of the processes undertaken at the UR-3R Facility which in turn processes municipal solid waste from the local government areas of Fairfield and Blacktown. This waste constituted the kerbside "garbage" collected within those areas. It was "garbage" or waste not identified by the occupier of premises, or not separated by the occupiers, as recyclable material. A significant proportion of its content was putrescible waste.
29The expert evidence led at the sentence hearing indicated disagreement as to whether environmental harm was occasioned to Marylands and its environs by the injection of liquid waste over the charge periods. The principal protagonists in this regard were Dr Brian Murphy, called by the prosecutor and Dr Peter Bacon, on behalf of Shannongrove. Other experts provided affidavit evidence directed to the topic, or rather, aspects of it, but it was deemed sufficient by the parties to focus upon the evidence of Drs Murphy and Bacon.
30Dr Murphy is a soil scientist whose expertise includes the interpretation of soil tests, measurement and management of soil structure, the assessment and management of sodic soil and the mapping and management of saline soils. Dr Bacon is an environmental scientist whose expertise includes the interpretation of soil and water analysis, the assessment of soil 'health' and predicative modelling of soil and water conditions. His work has also included the re-use of effluent on land.
31The focus of the debate between these experts was upon the accumulation of salts in the soil strata at Marylands and the environmental impact which that accumulation, if any, would have. There were two sources of data from which their consideration commenced. The first was a soil landscape map for the area and the second waste liquid and soil samples first taken by officers of the prosecutor on 6 July 2006. The soil landscape map for the area was used to identify the expected characteristics of the soil at Marylands. The general features of the soil within the Marylands site are described in the following way:
(a) the surface soils are non-saline, non-sodic, non-dispersible and acidic;
(b) the subsoils are becoming saline, are acidic, non-sodic and non-dispersible; and
(c) the deep subsoils are becoming strongly saline.
Although these characteristics were identified by Dr Murphy, I do not understand Dr Bacon to have disagreed with them.
32The second source of data were the results of liquid waste and soil tests taken by the prosecutor's investigators in July 2006. Those tests involved chemical analysis of samples of liquid taken from the delivery tanker driven by Shannongrove's employee on 5 July 2006; samples and analysis of liquid taken from the waste water tank at the UR-3R Facility on that same day and the analysis of soil samples taken at and in the vicinity of Marylands some days later. Soil samples were taken from the area on Marylands into which liquid waste had been injected and also from an area approximately 1km away that had not been used for injection of liquid waste. The latter sample was used as a control sample.
33While the sampling and testing undertaken in July 2006 was not undertaken by either of the two experts called before me, they had each inspected Marylands in 2009 and taken soil samples for analysis from similar locations within that property. Their test soil results for 2009 are, unsurprisingly, similar.
34Each of Dr Murphy and Dr Bacon focused upon the extent to which soil salinity at Marylands had been affected by introduction of the liquid waste. In the context of the various test results, the extent of soil salinity was reflected in the electrical conductivity measured in the samples. The measure of electrical conductivity was expressed in the various test results as a measure of decisiemens per metre (dS/m).
35Dr Murphy identified the analysis of the control soil sample, being that to which no liquid waste had been applied, as revealing low salinity, measured as being 0.13dS/m. He opined that those results were consistent with the properties of the soils identified for that soil on the soil landscape map. By contrast the mean electrical conductivity of soil samples taken from Marylands in July 2006 showed a mean level to be 2.08dS/m with a maximum of 4.2dS/m and minimum of 0.46dS/m. Dr Murphy considered that these levels showed high to very high salinity and were inconsistent with the salinity levels in soils identified for the site in the soil landscape map. He considered that these high levels were consistent with properties of the liquid waste that had been applied to the area, that liquid waste having a mean electrical conductivity level of 34dS/m.
36While Dr Bacon does not directly address these opinions, his criticisms are more broadly based. He challenges the extent of soil sampling as being sufficient; indicates that samples taken from the tanker at Marylands and the waste water tank at the UR-3R Facility were unrepresentative and asserts that the background levels of salinity at Marylands are not sufficiently known in order to draw the conclusions drawn by Dr Murphy. In his opinion, land clearing more than a century ago in order to accommodate farming activities as well as agricultural practices adopted over that period, could well have affected soil salinity so as to elevate its level to something approaching that measured in the soil samples taken in July 2006. He is unable to determine from the information available whether the control soil sample taken by the prosecutor's representatives represent the salinity of soil in the relevant paddocks of Marylands immediately prior to the introduction of liquid waste.
37If the 2006 data represented all that was available there would be substance in that criticism. However, the results of tests taken in 2009 indicate a considerable reduction in the conductivity then measured. The sample results recorded in Dr Murphy's evidence indicate levels in the upper soil profile and on the higher ground of the land that had been injected with liquid waste as ranging between 0.28dS/m and 0.14dS/m. Based on those figures, it is apparent that salinity had fallen between July 2006 and February 2009 when the latter samples were collected, a period coincident with the cessation of liquid waste injection.
38In his evidence, Dr Bacon was critical of the liquid waste sampling taken from the tanker delivering waste to Marylands on 5 July and sampling of the contents of the waste water tank at the UR-3R Facility on that same day. It was from the latter tank that Shannongrove's tanker was seen to load the waste taken to Marylands earlier in the day. Dr Bacon refers to the wide disparity in the measurement of analytes as between those obtained from the tanker liquid and those obtained from the waste water tank.
39However, that criticism was somewhat undermined in the course of Dr Bacon's cross-examination. He accepted that the preponderance of salts in the liquid waste was likely to be reflected in the analysis of total dissolved solids. Analysis of the waste water tank at the UR-3R Facility indicated that the total dissolved solids yielded a measure of 22,000mg/l. The same analysis of waste liquid taken from the Shannongrove tanker at Marylands was 21,333.3mg/l.
40Dr Bacon's attention was also drawn to the analysis of waste liquid from the same two sources that reflected electrical conductivity. The measure in the waste liquid from the UR-3R Facility was analysed as being 36dS/m while liquid from the tanker was analysed as being 34dS/m. Faced with these comparisons, Dr Bacon conceded that at least on the day of sampling, the liquid taken to Marylands for soil injection had a salinity level which was representative of that same level in the waste water storage tank at the UR-3R Facility. Nonetheless, he observed that those levels were likely to vary given the variation in the waste material brought to the facility for treatment.
41The third broad area of criticism made by Dr Bacon related to the extent of sampling undertaken both in 2006 and again by Dr Murphy in 2009. Standards for testing published by the prosecutor for testing of contaminated sites, required many more samples to be taken than those that had been taken in the present case. While the prosecutor sought to draw a distinction from the number of tests required for contaminated sites, usually required in order to determine the extent of remediation to be undertaken, and those taken in the present case, there is some substance in this criticism.
42The area within Marylands that had been the subject of liquid waste injection was a little over six hectares. Relatively few samples were taken over this area for soil analysis although Dr Murphy considered them sufficient to gain an understanding of the soil profile in 2006.
43The criticism directed to the small number of soil samples is exemplified by the tests taken in 2009. Only four sites were selected by Dr Murphy for soil testing. Two of those were in a upper area of the paddock on which liquid waste had been injected while two were in the low lying areas in which pasture was sparse or bare and which were described by both experts as being either "scorched" or "hotspots". While the level of salinity in the two samples collected from the upper areas showed 2009 levels that I have earlier recorded, Dr Bacon observed that their limited number did not enable a conclusion to be drawn as to the areal extent of salinity at those levels, relatively low as they were.
44By comparison with the levels recorded at the upper levels in 2009, the level of salinity in the scorched areas or hotspots was, by comparison, elevated. The level of electrical conductivity at one such area, described as Site 3, was in the range in the upper soil profile of between 0.73dS/m and 0.52dS/m. At the other site, described as Site 4, the upper level range was between 0.51dS/m and 0.22dS/m.
45Dr Murphy accepted that there had been a reduction in soil salinity between 2005 and 2009. Elevated salinity levels have the propensity to diminish the agricultural productivity of the affected land. While he accepted that this affect had diminished following cessation of liquid waste injection, the level of salinity at the scorched areas or hotspots indicated that the affect of elevated salinity was still being experienced. He indicated that these levels were indicative of an accumulation of salts, some of which may have infiltrated the soil strata and moved further down-slope or entered the groundwater system, ultimately affecting the quality of that groundwater, particularly as it entered local streams.
46Dr Bacon did not accept this conclusion. He acknowledged that the existence of hotspots in 2009 was indicative of elevated salinity in those areas. However, both the tests and his own observations had indicated that the aggregate of all areas so affected was a total of about 30m2 out of an area of approximately 64,000m2 that had been treated with the liquid waste transported by Shannongrove. His evidence also indicated that when he returned to the site in 2010, those areas that in the previous year had been identified as scorched or hotspots no longer appeared.
47Dr Bacon also relied upon evidence from the farm manager as to the productivity of the area that had been treated with waste. That evidence was, in summary, that the paddocks were highly productive with increased crop yields compared with other areas of the property. Further, when the area was grazed by dairy cattle, higher milk production than had previously been the case resulted. Photographs produced in evidence revealed the lushness of the area by comparison with other areas of the property.
48In the face of that evidence, Dr Murphy accepted that the treated area appeared to be highly productive. However, he opined that such an observation was not inconsistent with some accumulation of salt within the soil profile, even if it was at a depth that did not impair the growth of pasture crops. He indicated that such salts are not lost, but rather move within the soil profile. While those salts may be out of the root zone of crops, the existence of salts within the soil may have an impact if, in the future, the land should be differently used. If used for the erection of a building, the existence of those salts could have a deleterious effect upon foundation material placed in the soil.
49Ultimately, Dr Bacon accepted that the scorched areas or hotspots observed in 2009, small in area though they were, did demonstrate a residual impact from the salts introduced to the soil by the injection of liquid waste (Tcpt 22: 4-10). Nonetheless, he would not accept, in the absence of further testing, that the residual impact would extend beyond that area. He accepted that from other recorded observations, the initial impact of liquid waste injection may have detrimentally affected pasture crops. This, he suggested, was no different to the application of fertiliser to pasture at a level which may initially cause some setback but after a short time increases agricultural productivity, as had occurred at Marylands. Overall, therefore, it was his opinion that application of the liquid waste was beneficial rather than detrimental.
50My consideration of all this evidence leads me to be satisfied to the requisite standard that the liquid fertiliser applied to Marylands during the charge periods did elevate the level of salinity in the soils to which it was applied on Marylands. The surface effect of this salinity upon cropping of the property was short term, with the level of agricultural productivity quickly returning to most of the area. There was a residual impact that extended to lower lying areas through to 2009, but in the absence of more soil test data than is available, the evidence does not establish that the areal extent was significant.
51I accept the possibility that elevated salt levels may be present in the lower soil strata, although these would appear to be levels at which the soil profile is either becoming saline or is strongly saline. I am therefore unable to conclude that there is likely long term environmental harm.
52In the result, I find that the injection of liquid waste transported by Shannongrove to Marylands and injected by or on behalf of Shannongrove to the soil had short term environmental impact, having largely abated by February 2009. While it does not appear to have created any adverse effect upon the agronomic environment of Marylands, there remains the possibility of some effect upon the broader environment, although that effect cannot, on the evidence, be described as "likely". In short, the consequence of injecting liquid was in the low range of environmental harm.
53In reaching this conclusion, it has not been necessary for me to adjudicate upon the debate between the experts as to the prediction of likely harm had the liquid waste injection of soil continued beyond 5 July 2006. Shannongrove took it upon itself to cease its activity at Marylands; it applied for an environment protection licence in contemplation of resuming that activity, but ultimately neither resumed the activity nor pursued its licence application. It therefore seems to me that, for the purpose of determining penalty, I should not contemplate the consequence of events that did not occur.