The Environmental Protection Authority has recommended conditional approval of stage two of Fortescue Metals Group's Iron Bridge magnetite project in the Pilbara.
EPA chairman Dr Paul Vogel said a Public Environmental Review and extensive assessment had found the proposal could be managed to meet the Authority's objectives subject to a suite of strict conditions.
The EPA assessed the proposal against several environmental factors, namely flora and vegetation, terrestrial fauna, subterranean fauna, hydrological processes and inland waters environmental quality and offsets.
The open cut mine, 110 kilometres south-southeast of Port Hedland, is expected to operate for 45 years, producing 15 million tonnes of magnetite a year.
The proposal includes a slurry pipeline from the mine to Port Hedland to export the ore.
"This is a large mine with a long life expectancy so the EPA has recommended seventeen rigorous conditions to minimise and mitigate any potential environmental impacts," Dr Vogel said.
The 9.5mtpa, 68 per cent magnetite concentrate stage two construction is expected to commence in 2015, subject to a feasibility study and at Fortescue's option.
Stage one construction, which is already underway, is expected to take 12 months, with first production of 1.5mtpa of 66 per cent magnetite-hematite ore expected early next year.
Iron Bridge is a joint venture between Fortescue, China's Baosteel and Taiwanese conglomerate Formosa Plastics Group.
The EPA's report to Environment Minister Albert Jacob is now open for a two-week public appeal period.
Appeals close on July 7 and can be made at www.appealsconvenor.wa.gov.au .
The proposal is also being assessed under a bilateral agreement with the Commonwealth.
EPA Report 1514 is available at www.epa.wa.gov.au .