Hydro’s plans to demolish the smelter and remediate the site are on display for comment to the NSW Department of Planning, with the deadline for comment on Monday. The main environmental problem at the site is “spent pot-liner”, internationally recognised as a hazardous material that is toxic, reactive and corrosive.

Hydro’s has two lots of spent pot-liner to deal with. From 1969 until about 1993 spent pot-liner was stockpiled east of the smelter in an area known colloquially as “Mount Alcan”. This material is to be dug up and moved by truck to a new purpose-built cell about 1km away on the western side of the smelter buildings.

Post-1993 spent pot-liner is stored in sheds. Hydro had first proposed to put this material in the containment cell but it now proposes to have it treated off-site.

Hydro managing director Richard Brown said on Friday that the material in the sheds was not included in the remediation approval.

“We are committed to find re-use or recycling options for his material and will have a better understanding of the options later in the year,” Mr Brown said.

“Based on our market investigations for recycling spent pot lining stored in the sheds, we firmly believe there are no recycling options available for the pot-liner in the ground due to cross-contamination and health and safety risks.”

Ms Swanson said she was seeking briefings from Hydro and from other industry experts about what was being planned for the former smelter site.

Hydro’s environmental statement says the new cell is expected to contained almost 480,000 tonnes of material, including 320,000 tonnes from the existing capped stockpile.

Also at Kurri, Garbis Simonian’s Weston Aluminium has plans on display until October 24 for a $5.5 million incinerator to treat medical and other wastes including pharmaceuticals, paint, computer hard drives, documents and seized drugs.