BHP Billiton Ltd. (BHP.AU) has submitted documents seeking environmental approval for the next stage of the expansion of its iron ore operations in the Pilbara region of Western Australia, which will see it dredge Port Hedland Harbor.

On May 29 the miner made a referral to the Department of the Environment for its Rapid Growth Project 6 and specifically for the dredging of a 60 hectare area of Port Hedland Harbour.

In the document, the miner said the dredging would allow the port to accommodate larger vessels in order to meet increasing demand for iron ore.

BHP said the offshore disposal of dredged material was expected to start in the fourth quarter of 2009 and take 68 weeks and the onshore disposal was expected to take 46 weeks and start in the first quarter of 2010.

RGP6 is designed to boost the capacity of BHP's Pilbara iron ore mines, rail and port operations to about 240 million metric tons by 2012.

The public has 10 days from the filing of the document to make comment on the proposed dredging of the harbor and then the department has another 10 days to rule whether BHP will be required to provide a detailed environmental impact statement or not.

-By Alex Wilson, Dow Jones Newswires; 61-3-9292-2094; alex.wilson@dowjones.com