"The EIS (Environmental Impact Statement) and public comment were thoroughly reviewed by the Office of Environment and Heritage who prepared a comprehensive assessment report containing 29 recommendations," NT environment minister Marion Scrymgour said.

"The Office of Environment and Heritage has concluded that the environmental issues associated with the Alcan expansion have been adequately identified, and the expansion can be managed in a way that avoids unacceptable environmental impacts.”

However the Government has placed strict conditions on the development, requiring Alcan to monitor the social and environmental impact on surrounding areas and maintain its strong relationship with the local indigenous culture.

"I expect these recommendations to be taken up in the Mining Management Plan which needs to be approved before the expansion can proceed," Scrymgour said.

Despite the approval Alcan itself has not yet granted final approval for the expansion.

Last week it was revealed in The Australian newspaper that the initial timeframe had been abandoned as the project team had yet to finalise numbers and, without firm costs, there was no basis on which to take the project to the company's board. However final approval is expected once the final proposal has been delivered.

Delays in determining the precise route of the Trans-Territory pipeline will result in the expanded refinery’s initial operation on oil.

Additionally the Northern Land Council has applied for Federal Government assistance to take equity in the $500 million pipeline that would bring gas from Blacktip to Gove.