BHP faces clean-up bill: report

BHP Billiton (BHP) is facing a $100 million contamination bill at its old Mount Goldsworthy iron ore project in the Pilbara after acid contamination was discovered at the site, The Australian reports.

According to the newspaper, the discovery could threaten BHP's sale of the site to Nimbus Mines, who are seeking to re-open it as an underground mine.

Documents obtained by the newspaper show confidential talks took place between the parties last year and under the proposed agreement BHP would retain the magnetite resources at Mount Goldsworthy, while Nimbus would mine its high-grade hematite ore.

The Australian reports the documents also outlined BHP's request to be "fully released" from its potential environmental liability at the site, with the approval of WA premier Colin Barnett.