NSW Land and Environment Court has convicted and fined Wambo Coal Pty Ltd a total of $62,000 after a sediment dam failed at its Warkworth coal mine in the Hunter Valley causing water pollution.
The Court also ordered Wambo to publish notices in the Newcastle Herald and Singleton Argus and to pay the EPA’s legal costs of $67,130 and investigation costs of $2,590.
EPA Chief Environmental Regulator Mark Gifford said Wambo contravened its environment protection licence by failing to carry out activities in a competent manner.
“Wambo Coal has a responsibility to ensure its activities do not cause harm to the environment,” Mr Gifford said.
The incident occurred in the first week of January 2016 following heavy rain in the region, when a portion of the dam wall collapsed resulting in sediment-laden runoff escaping from the dam.
The sediment-laden water flowed along an ephemeral drainage line and into Waterfall Creek which eventually leads to the Hunter River. However, no visible sediment deposition was observed outside of the Wambo mine boundary and any impacts to waterways from the incident would have been temporary.
Wambo Coal reported the incident to the EPA on Monday,January, 11 after Wambo staff had inspected the dam and identified the failure. However, it is estimated that the dam wall collapse occurred around January, 5.
Mr Gifford said the spillway had insufficient capacity to carry the runoff from the rain event and this, together with the unsuitable methods used to construct the dam, contributed to the dam’s failure.
“The company did not have adequate procedures in place to ensure that the new dam was constructed to design and fit for purpose, so as to prevent this incident.”
After the incident Wambo undertook immediate remediation works, including reconstruction of the dam. It also introduced new training for staff and procedures to improve the management of sediment and erosion controls on site.
Justice Pain handed down her decision on sentence on Monday, fining Wambo Coal $42,000 for the licence breach offence and $20,000 for the water pollution offence.