Water and humidity cause abundance of toxic waste at redevelopment site

Posted 7 December 2017

Construction site
Thousands of tonnes of toxic waste has been uncovered during excavation at the Westfield Kotara redevelopment, resulting from waste matter exposed to water and humidity, according to a NSW Environment Protection Authority (EPA) investigation. 

Concerns for workers’ health and local environments arose as waste – made up of aluminium salt slag containing arsenic, cyanide, chloride, aluminium, sulphide and fluoride – was formed in the production of scrap aluminium, commonly used as landfill in sites around the Hunter before its detrimental effects were publicly known. 

Sydney-based risk management consultant Greencap released a report on the incident, identifying that the main concern is the slag’s leachability and its reactivity to water and humidity, which can cause toxic, explosive gases. 

“The gas emissions from the salt slag that result from contact with water are of great environmental concern,” the report states.

Excavation works were halted when workers became aware of the contamination due to the smell of the slag being exposed to the atmosphere. 

“The EPA continues to investigate the matter and is reviewing documentation provided to it by the parties involved,” a spokesperson for the NSW EPA said.