Harm caused to the environment: s 241(1)(a) of the POEO Act
73The word "harm" in the context of the phrase "harm to the environment" is defined in the Dictionary to the POEO Act. It is defined to include:
"... any direct or indirect alteration of the environment but has the effect of degrading the environment and, without limiting the generality of the above, includes any act or omission that results in pollution."
There can be no doubt that, within the meaning of that definition, there was environmental harm occasioned by the commission of the offence. The physical condition of the waters of the Marine Park were altered by reason of the flow of sediment from the Property into those waters.
74At the level of principle, it is necessary to consider harmfulness not only by identifying the actual harm, but also considering the potential or risk of harm by reason of the acts or omissions that found the offence in question. (Environment Protection Authority v Waste Recycling and Processing Corporation [2006] NSWLEC 419; (2006) 148 LGERA 299 at [145]). This principle is important to be noticed because the defendant submits that there was no evidence of actual harm by the discharge of sediment into North Arm Cove. In making that submission, the defendant clearly does not include the visual appearance of the water described by the oyster fishermen in the vicinity of the Property when the discharge occurred. They described that discharge of dirty muddy water, with debris, leaf matter, sticks and logs, turning the seawater "a dirty creamy colour". This discharge took place into the clear and apparently clean waters of the North Arm Cove estuary. These observations leave no doubt about the visual pollution that occurred.
75The essence of the defendant's submissions in this regard seem not to quarrel with the appearance of the sediment-laden discharge but rather to suggest that pulses of similarly coloured discharges from the Property and surrounding land would have occurred naturally following heavy rainfall. While there was some evidence of a general nature that run-off from land into the estuary is likely to have occurred following rainfall, no evidence was led to suggest that the discharge occasioned by the defendant on 19 May was directly comparable to that which would occur following heavy rain. Not the least reason for this is the fact that the volume of dirty water discharged on 19 May 2009 is unknown.
76The extent to which there was either actual or potential harm from the discharge that occurred on 19 May 2009 was the subject of two sources of evidence. The first was from Dr Alan Jordan and Mr Paul Anink, experts retained by the prosecutor and defendant respectively, whose evidence was directed to marine ecology. The second source of reference directed to potential harm was that from oyster farmers who observed the occurrence and who held oyster leases for areas within the North Arm Cove estuary.
77Dr Alan Jordan is a senior environmental scientist who, at all relevant times, was employed in DECCW. Paul Anink is an environmental scientist specialising in marine and freshwater ecology. Prior to the sentence hearing, Dr Jordan and Mr Anink met, as a result of which they prepared a joint statement directed to the environmental impact upon the waters of North Arm Cove following the discharge from the Property on 19 May. In this context, they addressed three issues:
(i)the extent of sediment deposition;
(ii)the extent of impact upon the benthos; and
(iii)the impacts on seagrass.
The joint report of these experts reveals agreement between them in assessing the environmental impact, based upon the observations recorded at the time of discharge, their knowledge of the local environment and their subsequent visits to the area.
78Having regard to the evidence with which they were provided, Dr Jordan and Mr Anink accept that there was an unquantified volume of fine sand, silts and clay deposited onto the intertidal shores of North Arm Cove. The deposit of these materials would have resulted in progressive settlement of coarser material inshore and finer material offshore. Although core samples had been taken by investigation offices from DECC, there was a lack of adequate information as to the location of these cores or their content, with the result that they were unable to provide "any considered judgment as to the depths of deposited sediments."
79The experts agree that there was insufficient data to enable them to reach any conclusion upon the impact that this material would have had on the benthos. They accepted that on the information provided, the spatial extent of deposition "could have been in the order of 2,000 to 4,000m2 of intertidal seabed comprising thin sand over coffee rock inshore to sandy silt offshore." They accepted that the impacts on "benthic assemblages" would not have been statistically significant. Further, impacts upon the conservation values of the Marine Park were agreed to be negligible "at least on the basis that following impact there would have been recovery/recolonisation within a reasonable time." Implicit in that agreement is impact from the deposition of sediments albeit of short-term duration.
80It is apparent from the joint report that, given the seagrass distribution in the North Arm Cove estuary, there was no indication of measurable change on seagrass plants or on seagrass biota. The scientists concluded that "on the basis of probability there was likely no significant impact on the medium term basis." Once again, these expressions of opinion, which I accept, indicate that while some harm may have been occasioned to the marine ecology, it was both minor and of short-term duration.
81On the morning of 19 May 2009, the holders of an oyster lease in North Arm Cove were working on racks and trays of oysters that were in the last cycle of growth prior to harvesting and sale. This lease area was used by the farmers in question as a harvest area, meaning that oysters were transferred to this area for a period of six to nine months in order to finish the growth cycle and "fattening" before sale. Any fall in water salinity at this stage of the growth cycle had the potential to cause spawning of the oysters, meaning that they would lose condition and become unsaleable.
82As I have earlier recorded, on the morning of 19 May the oyster farmers heard a noise associated with the breach of the dam wall at about 10.00am. They observed water gush towards the shoreline and then run into an area of North Arm Cove near to the oyster lease area. They were able to observe the flow of dirty coloured water from the Property as it spread across North Arm Cove in the direction of their oyster racks. They returned immediately to those racks closest to the plume of dirty water, collecting trays of oysters that had just been washed. They did this not only to avoid the oysters being affected by any of the sediment but also in anticipation that the water was freshwater, having the potential to lower the level of salinity. They were successful in removing all of the washed trays, with the consequence that there was not ultimately any detrimental impact upon their oysters.
83As was observed by Mr Anink in his evidence, the oyster farmers "had a right to be concerned ... as at the time they were in no position to know the extent, origin or content of the plume." As it happened, water quality measurements undertaken by officers of DECC on 19 May, following the discharge, indicated that water quality parameters were within guideline values for oyster aquaculture as recorded in a table to State Environmental Planning Policy No 62 - Sustainable Aquaculture. Nonetheless, Mr Anink acknowledged not only the legitimate concern of the oyster farmers, as I have indicated, but he also acknowledged that additional work was occasioned for them by delaying harvesting until satisfied that oysters had naturally depurated any residual sediments that may have been ingested from the water discharged from the Property.
84It is apparent from this evidence that, fortuitously, no actual harm was occasioned to the oysters. Nonetheless, the evidence also makes clear the potential for harm to the oysters growing in North Arm Cove.
85Considering all elements of "harm", within the meaning of s 241(1)(a) of the POEO Act, I conclude that, overall, the environmental harm was in the relatively low range.