Agreed facts
4 The defendant has been incorporated since 1957 as stated in the agreed facts. The affidavit of Mr Ronald James Yates sworn 12 December 2003 deposes that the defendant was incorporated in 1961. It is a large construction and infrastructure company specialising in civil engineering and building construction, mining works, project management, asset management, maintenance and other related activities.
5 In February 2002 the defendant began a project subject to a contract with the Roads and Traffic Authority ("the RTA") which involved construction of a 6km rapid bus transitway between Victoria Street and Fairfield Road, Wetherill Park. The majority of the transitway was located adjacent to the Sydney Water pipeline. On 7 August 2002 another section of work located between Horsley Drive and Victoria Street, Wetherill Park and known as the "Section 4 Portion A" was included in the contract.
6 After 7 August 2002 the RTA orally instructed the defendant to provide a quote for the demolition of chicken sheds belonging to Myella Chickens and located at 1191 Horsley Drive. The scope of this work was confirmed in a letter dated 15 August 2002 from the RTA to the defendant. Myella Chickens held an environment protection licence in relation to its poultry production at 1191 Horsley Drive but following the building of the transitway Myella Chickens no longer operates this property.
7 On 1191 Horsley Drive was a wastewater dam which collected liquid waste from the Myella Chicken processing plant. The dewatering of the dam was not included in the scope of work stipulated in the letter of the RTA dated 15 August 2002. The RTA had engaged environmental experts, Golder Associates Pty Ltd ("Golder Associates"), to test the liquid stored in the wastewater dam prior to its contract with the defendant. Golder Associates provided the RTA with a report which recommended that laboratory certificates for the dam wastewater be provided to a licensed disposal operator to obtain a proposal for disposal. The RTA also considered the possibility of discharging the wastewater onsite. The RTA and the defendant met to discuss the practicality of such an option and it was discussed that the natural ground would be a suitable medium for filtration of the pond liquid and that the liquid would flow to a low lying naturally bunded area.
8 The RTA instructed the defendant in writing on 13 August 2002 that it was to use a licensed operator to remove the wastewater from the dam and also the sediment so that it dried out onsite and would be buried under a clean earth capping. The defendant complied with the RTA's instructions and sought quotes from various disposal operators. The defendant orally advised the RTA of the costs associated with off-site disposal of the wastewater on 13 August 2002.
9 On 16 August 2002 Golder Associates advised the RTA by fax that it had discussed with the prosecutor another option considered by the RTA to remove the wastewater by pumping the wastewater on the land at 1191 Horsley Drive utilising a natural bunded area and vegetation strip to contain the wastewater and prevent it from escaping. A representative from the prosector agreed in principle with this method provided that any run off did not enter a watercourse. Subsequently the RTA advised the defendant to prepare for the pumping of the wastewater from the dam to the natural ground according to such method.
10 On 17 August 2002 the RTA and the defendant attended a site meeting at 1191 Horsley Drive. At such meeting the RTA instructed the defendant to commence with the dewatering of the wastewater dam. The staff of the defendant gained the impression from the RTA and Golder Associates that the prosecutor had approved that onsite disposal of the wastewater should commence. The method discussed by the RTA and the defendant by which the wastewater should be dewatered included a consideration of how the discharging hoses would be positioned on 1191 Horsley Drive. The RTA and the defendant both believed that the natural bunded area would prevent any dam water escaping from 1191 Horsley Drive and that the thick cover of Kikuyu grass would act as a filter to allow absorption of the wastewater into the soil.
11 On 19 August 2002 Rick Cassab of the defendant wrote to the RTA to confirm that the wastewater would be dispersed on 1191 Horsley Drive and set out the means by which this would be achieved.
12 On the morning of 19 August 2002 the defendant established two pumps at 1191 Horsley Drive and pumping commenced that afternoon. The defendant undertook to monitor the operation of the pumping and the runoff. At 5pm of that afternoon the pumps were turned off as work had completed for that day.
13 On 20 August 2002 the two pumps were re-established and pumping commenced at approximately 7.30am. The pumps operated all day until 5pm. The pumps were monitored by Mr Cassab, Mr Shane Pearce of the defendant and a number of other site workers. Mr Cassab and Mr Pearce focussed their attention in the direction of the bunded area as it was anticipated that the wastewater would flow there. They did not inspect the rear of 1191 Horsley Drive as they did not believe they could gain access from the construction site due to the height and thickness of the vegetation.
14 Adjoining 1191 Horsley Drive is Dairy Farmers Pty Limited ("Dairy Farmers") which has a car park approximately 170m from the area that was irrigated by the defendant. At about 4.50am on 20 August 2002 a security guard of Dairy Farmers, Mr Nicholas Agius, drove into the car park and saw water running across the pavement. Mr Agius investigated the source of the water and it appeared that it was coming from 1191 Horsley Drive. He estimated that the water was 5mm in depth and smelt like sewerage. Mr Agius contacted the Engineering Manager of Dairy Farmers, Mr Gary Neilson, and advised him of the running water. Mr Neilson arrived at the car park after 9am and saw that the water was flowing under the fence from 1191 Horsley Drive into two places and entering the stormwater drains in the car park. Mr Neilson estimated that the water was approximately 6m wide and had a depth of 5mm. He rang Fairfield City Council ("the council") and advised them of the incident.
15 On 21 August 2002 at approximately 9am Mr Neilson saw water still flowing across the car park from 1191 Horsley Drive. He contacted the council again and met with the environmental health officer of the council, namely Mr Ken Jones. Mr Jones observed the water flowing across the car park and noticed it was brown in colour and was flowing in the stormwater drains. Mr Jones walked to the boundary fence between 1191 Horsley Drive and Dairy Farmers and saw that the brown coloured water, which had an odour similar to that of sewerage effluent, was collecting in the grass swale in the boundary fence. Mr Jones took a series of photographs of what he had observed.
16 Mr Jones investigated the source of such water and saw two pumps located at the rear of 1191 Horsley Drive. He observed the exhaust noise of the petrol motors attached to the pumps and he could see the pulsing hoses connected to the pumps. Attached to the first pump was a discharge hose and suction hose both about 65mm in diameter. Connected to the second pump was also a discharge hose and a suction hose both being about 50mm in diameter. Mr Jones saw that the outlet hoses were about 38mm in diameter. Mr Jones observed that all the wastewater from the processing of chickens on 1191 Horsley Drive was collected in a series of pits and pipe work which then flowed to the wastewater dam at the rear of such property.
17 Mr Jones was approached by two men of the defendant including Mr Cassab. Mr Cassab explained to Mr Jones that the chicken sheds were being demolished and the wastewater dam was to be filled for the new transitway. Mr Cassab was unaware that the wastewater that was being pumped was entering Dairy Farmers and its stormwater drains. Mr Jones showed Mr Cassab and the other man the brown water flowing under the boundary fence between 1191 Horsley Drive and Dairy Farmers. Mr Cassab immediately turned off the pumps and removed the hoses from the wastewater dam. To prevent further runoff Mr Cassab arranged and supervised the immediate construction of an earth berm in the vicinity of the flow path of the wastewater. He also arranged for the construction of a silt fence on the boundary between the paddock on 1191 Horsley Drive and the Dairy Farmers' car park.
18 Mr Durrington an officer of the prosecutor attended 1191 Horsley Drive at approximately 12.30pm that day. Mr Jones informed Mr Durrington of the incident and what he had observed. Mr Durrington also inspected the wastewater dam, the pumps and took various photographs. He observed that the wastewater dams were black and that there was white scum on the surface. There was also a strong odour coming from the wastewater dam which he knew to be of the type from wastewater dams at poultry processing plants. Mr Durrington saw that the wastewater had flowed under the boundary fence and noticed that the wastewater had also formed a pond in a grassed depression near the boundary fence.
19 Stormwater diagrams reveal that the stormwater drains in the Dairy Farmers' car park go under the car park and end up in a stormwater pit located on the footpath alongside Canley Vale Road. Such stormwater pit leads to a stormwater canal, approximately 730m from the Dairy Farmers' car park which in turn connects to Prospect Creek, about 1600m away from the Dairy Farmers' car park. Mr Durrington took samples from various points along the stormwater pipes and where the pipes enter the canal.
20 One sample taken by Mr Durrington showed that results for the water in the canal upstream of where the stormwater pipes enter the canal, were well above the guideline value for the protection of aquatic life. The total phosphorus sample showed 390ug/L and the free reactive phosphorus showed 280ug/L. Another sample from the water in the channel downstream from where the three stormwater pipes enter the canal showed that the total phosphorus sample was 5200ug/L and the free reactive phosphorus showed 3800ug/L as well as higher readings in Ammonia-N and TKN.
21 Mr Cassab prepared an incident report and identified three potential causes which may have caused the incident as follows:-
1. Our investigations found that the water from the pump discharge must have found a preferential path/depression underneath the thick grasses that could not be seen by eye. This path diverted the majority of the water flows from its intended location into the bunded area, over towards the Dairy Farmers carpark approximately 100m from the discharge points. This can also be substantiated by the fact that water flowed into the carpark from two points, not one, indicating depression scour drains must have formed over time that could not be seen by any of the parties involved.
2. The low-lying bunded area initially had no water. Once pumping had commenced, it was observed that water was flowing (at a trickle) into the bunded area substantiating our belief that the operation was working effectively. We continued to monitor this area and not the dairy farmers carpark due to its relative remoteness from the points of discharge.
3. Pumps may have been oversize resulting in the inability of the grass to absorb the flows (although this was not evident at the time due to point 2 above)
22 As a result of the incident the RTA directed the defendant to remove the remaining wastewater from the wastewater dam using licensed operators and to continue to monitor offsite disposal.