ENVIRONMENT

Warkworth penalised $50K for dam wall collapse

Up to 4.4 megalitres of sediment laden water escaped into surrounding areas.

Lou Caruana
Warkworth penalised $50K for dam wall collapse

Warkworth was prosecuted by the Environment Protection Authority for breaching a condition of its Environmental Protection Licence that requires it to carry out its licensed activities in a competent manner.

The prosecution was in relation to an incident at the Warkworth mine when part of a sediment dam wall collapsed on January 5 2016 following several days of heavy rain. 

Up to 4.4 megalitres of sediment laden water escaped into surrounding areas, including the nearby Wallaby Scrub Road reserve.

Warkworth had modified the dam to increase its capacity. However, neither the design nor the construction work was undertaken or overseen by an engineer, nor did Warkworth subject the completed works to an appropriate risk assessment or other quality assurance processes.

A section of the embankment wall collapsed when water levels reached the heightened embankment wall for the first time.

EPA north regional director Adam Gilligan said the dam wall failed due to a phenomenon known as “piping”, which occurs when circular shaped fissures form in the core of the dam wall due to excessive hydraulic pressure.

“It was estimated that at the time of the dam failure there was approximately 4.56ML of water in the dam,” Gilligan said.

“It is estimated that the discharge from the dam embankment took up to 18.5 hours.

“Ensuring that environment protection licence holders carry out their activities in a competent manner is an important part of a regulatory scheme that requires industries to take practical and reasonable steps to reduce their impact on the health of the community and environment.”

Gilligan said the court decision served as a warning to all operators to ensure they complied with their licensing requirements and carry out their activities in a competent manner.

Warkworth pleaded guilty to the offence. 

In addition to the $50,000 penalty, which is payable to the Environmental Trust for general environmental purposes, the court ordered Warkworth to pay the prosecutor’s legal costs and to publish notices in the Singleton Argus and the Newcastle Herald detailing the conviction.

 

A growing series of reports, each focused on a key discussion point for the mining sector, brought to you by the Mining Monthly Intelligence team.

A growing series of reports, each focused on a key discussion point for the mining sector, brought to you by the Mining Monthly Intelligence team.

editions

Mining Magazine Intelligence Exploration Report 2024 (feat. Opaxe data)

A comprehensive review of exploration trends and technologies, highlighting the best intercepts and discoveries and the latest initial resource estimates.

editions

Mining Magazine Intelligence Future Fleets Report 2024

The report paints a picture of the equipment landscape and includes detailed profiles of mines that are employing these fleets

editions

Mining Magazine Intelligence Digitalisation Report 2023

An in-depth review of operations that use digitalisation technology to drive improvements across all areas of mining production

editions

Mining Magazine Intelligence Automation Report 2023

An in-depth review of operations using autonomous solutions in every region and sector, including analysis of the factors driving investment decisions