Environmental Harm Caused by the Incident
82The environmental harm caused by the commission of an offence is, as was stated in the principal judgment (at [116]-[118]), a central consideration in determining the objective gravity of the offence. The concept of harm in the context of environmental offences is broad and includes the potential or risk of harm, not merely actual harm (see the authorities referred to in the principal judgment at [117]). Harm can be direct, indirect or cumulative and activities that contribute incrementally to the gradual deterioration of the environment, even when they cause no discernable direct harm to human interest, must nonetheless be treated seriously.
83Section 241(1)(a) of the POEOA makes it clear that, in sentencing, the Court must consider the "extent of the harm caused or likely to be caused to the environment by the commission of the offence". The POEOA defines "harm to the environment" to include "any direct or indirect alteration of the environment that has the effect of degrading the environment and, without limiting the generality of the above, includes any act or omission that results in pollution".
84Mercury is known to have a number of potential health effects when people are exposed at particular concentrations or for extended periods. These include:
(a)it can cause irritation of the eyes, skin and respiratory system if those parts of the body are exposed to it; and
(b)over a long period of time it can produce chronic adverse effects. Repeated minor exposures to mercury may have a cumulative poisoning effect.
85These potential adverse impacts were described in Orica's Safety Data Sheet for mercury. The Safety Data Sheet indicates that mercury is:
(a)classified as a "hazardous substance" according to Safe Work Australia criteria;
(b)classified as a "dangerous good" according to the Australian Dangerous Goods Code criteria;
(c)classified as a "dangerous poison" (S7) under the Poisons Schedule; and
(d)in terms of its risk profile, classified as:
Very toxic by inhalation. Toxic: danger of serious damage to health by prolonged exposure through inhalation. Very toxic to aquatic organisms. May cause long term adverse effects in the aquatic environment. May cause harm to the unborn child.
86Additional toxicological information, including its potential long term and overexposure impacts, were also described in the Safety Data Sheet, that cautioned to "[a]void release to the environment".
87The Incident resulted in elevated mercury vapour concentrations being recorded between 2.00am and 9.00am on 27 September 2011 at the Lumex meter, located 25m within the boundary of the premises, with the maximum 30 minute average exceeding 4.0µg/m3. The Lumex meter is approximately 50m from the nearest residence.
88The Incident had the potential to disperse mercury vapour downwind of the premises and towards the residential area of Botany. The downwind environment consists of low density residential areas with the following receptors:
(a)humans, namely, workers and offsite residents who may have been exposed to mercury vapour in the air during the Incident;
(b)plants, soil and other terrestrial and aquatic environments; and
(c)domestic pets within offsite residential areas.
89Two reports were prepared after the Botany Mercury Incident regarding the likely health and environmental impacts as a result of the discharge.
90A health assessment report entitled "Health Impact of Mercury Exceedance" was prepared by Toxikos on 29 September 2011. The report concluded that:
(a)the average concentration over the exposure period at the boundary fence of the premises was estimated at 1.68µg/m3 (inside the fence line);
(b)the total potential exposure to a person at the boundary fence was approximately 6.7µg of mercury and for a 70kg person was 0.1µg/kg/day;
(c)the single exposure to a dose of 0.1µg/kg/day of mercury was approximately 20 times less than the lifetime tolerable daily intake of inorganic mercury (the form of mercury involved in the Botany Mercury Incident). This was, however, a level that assumed an exposure to mercury every day over a person's entire life, and sets the level of 2.0µg/kg/day as a tolerable daily level of exposure. This is the limit established by the World Health Organisation;
(d)the single exposure of 0.1µg/kg/day of mercury is about the same as the average total daily intake from diet and dental amalgam of all forms of mercury (as reported in a 1999 US Department of Health toxicological profile);
(e)the potential exposure was less than the tolerable daily intake for mercury and less than, or about the same as, long term or lifetime daily exposures that do not cause demonstrable health effects; and
(f)therefore, "health effects resulting from the incident are very unlikely".
91An environmental effects report entitled "Initial Assessment of Potential Effects associated with Elevated Ambient Mercury Concentrations from Former CAP on 27 September 2011" was prepared by Environmental Risk Sciences on 29 September 2011. The report concluded that:
(a)the Incident exceeded the adopted short duration action level established between the EPA and Orica of 1.8µg/m3 as a trigger for action in relation to the operation of the FCAP Remediation Project;
(b)the most significant environment likely to be impacted by the elevated mercury concentrations were the offsite residential areas (noting that the vapour exceedance occurred overnight, between 12pm and 9am, when workers were not present) where low levels of mercury vapour may have been inhaled during the Incident. Adverse effects on terrestrial and aquatic environments were considered negligible; and
(c)the monitoring measurements indicated that "no adverse health effects are expected to have occurred off-site as a result" of the Incident. This conclusion was based on the nature of the event (as a single release event), the concentrations reported at the premises, the distance of the residential areas from the monitoring point, and the available criteria for assessing acute mercury exposure events associated with accidental vapour release scenarios.
92Orica received seven complaints and inquiries regarding the Incident. These complaints expressed concern about the elevated mercury vapour concentrations near the boundary of the premises, questioned why residents and local businesses were not notified directly of the Incident, and queried the risks associated with the mercury release. Most of the complaints were from residents and one was from a local business expressing concern for the health and wellbeing of its staff and requesting to be notified immediately of any subsequent pollution incidents on the premises.
93Presumably in light of this evidence, it was recorded as an agreed fact that no actual, or even likely, environmental harm was occasioned by the Incident.
94Notwithstanding this agreement, the EPA nevertheless submitted that the commission of the offence caused environmental harm because:
(a)mercury is a pollutant that was released into the environment as a result of the offence. Elevated mercury vapour concentrations were recorded on 27 September 2011 at the Lumex meter, with the maximum 30 minute average exceeding 4.0µg/m3, which was more than twice the action level of 1.8µg/m3 at which Orica is required to take mitigation action under its Ambient Air Monitoring Program in order to protect human health at nearby residences. The Lumex meter is around 50m from the nearest residence;
(b)the release of mercury had the potential to disperse mercury vapour downwind of the premises and towards the nearby residential areas of Botany. Mercury absorption over a long period of time can cause adverse health impacts because repeated minor exposures can have a cumulative poisoning effect. In this case, the mercury vapour had the potential to be absorbed by humans, both nearby residents located offsite and workers onsite, and by domestic pets in offsite residential areas. Additionally, it had the potential to be absorbed into surrounding terrestrial and aquatic environments; and
(c)harm includes loss of amenity or quality of life. The community was concerned by the Incident. Orica received public complaints and queries about the Incident. One resident was "extremely concerned", another had significant concerns about Orica's ability to manage its own safety, a third caller was distressed and feared for the health of her daughter who lived near the premises, and a fourth was an adjacent business that was "extremely disappointed" at not being notified and expressed concerns for the health and wellbeing of its staff.
95Orica submitted that not only was there no actual or likely environmental harm, nor was there any potential environmental harm. This was because:
(a)the action levels were trigger levels that were deliberately set at a "very conservative limit";
(b)the Toxikos report had concluded that any health effects resulting from the Incident were very unlikely;
(c)the Environmental Risk Sciences report had concluded that no adverse health effects were expected to have occurred offsite as a result of the Incident; and
(d)the fact that a concentration level is above a set action level did not mean that human health was seriously at risk. It was an agreed fact that the potential exposure of a person standing on the boundary of the premises was approximately the same as the average total daily intake from diet and all other forms of mercury and was also less than the lifetime tolerable daily intake of inorganic mercury (which refers to the amount considered acceptable assuming an exposure to that amount every day over a person's lifetime rather than an exposure on a single day).
96In addition, Orica challenged the EPA's submission that the loss of amenity associated with community health concerns was relevant to an assessment of the harm caused by the Incident. Orica highlighted that the complaints followed a NSW Department of Health media release which incorrectly stated that there had been an "emission of mercury vapour that exceeded the levels defined in the licence".
97There can be no doubt that the release of mercury at elevated concentrations into the atmosphere was, as a matter of law, capable of satisfying the definition of "harm to the environment" in the POEOA insofar as it includes any act that results in pollution. This is consistent with the broad description of the concept of harm to the environment given by Preston J in Environment Protection Authority v Waste Recycling and Processing Corporation [2006] NSWLEC 419; (2006) 148 LGERA 299 (at [145]-[147]). However, given that the EPA and Orica agreed that there had been no actual or likely harm caused by the Incident, I do not understand how this assists the EPA.
98Furthermore, I agree with Orica that the seven complaints, received as they were after the factually incorrect media release was issued, is insufficient evidence of a loss of amenity suffered by the community caused by the commission of the offence.
99However, I accept that the Incident had the potential (as opposed to the 'likelihood') to cause environmental harm. As Orica's Safety Data Sheet establishes, mercury is a poison with high toxicity to humans in sufficient concentrations and over prolonged periods of exposure. It is classified as:
(a)a "hazardous substance";
(b)a "dangerous good";
(c)a "dangerous poison"; and
(d)"very toxic by inhalation".
100Nevertheless, because the actual levels of mercury vapour recorded were low enough to reduce the risk of environmental harm to an almost negligible level, the potential to cause harm to the environment by the breach of the licence condition must be characterised as remote, particularly in light of the steps that Orica took in the aftermath of the Incident to minimise any environmental harm, such as closing and sealing louvres and roof ducts.
101It also follows that the submission by the EPA that the Incident caused substantial harm should be taken into account as an aggravating factor, must be rejected (s 21A(2)(g) of the CSPA).