Senate Standing Committee on Environment and Communications

Answers to Estimates questions on notice by the Office of the Supervising Scientist on 23  May 2012

Senator Ludlam asked:

Senator LUDLAM:...I have questions about the retention ponds that the company is putting on site. Can you confirm for us whether or not ERA are using four-millimetre low permeability
lining on those retention ponds?
Mr Hughes: Sorry, I would have to take that on notice.
Senator LUDLAM: ...Could you undertake for us on notice to investigate whether they are using the best technology that exists or whether there is some cost-cutting going on?

Answer:
Energy Resources of Australia Limited has submitted an application for regulatory approval for the first of two proposed retention ponds at Ranger. The application states that the retention
pond will be constructed using two 2 millimetre thick high density polyethylene, low permeability liners separated by a leak detection membrane, supported by a compacted clay base. It is anticipated that the other retention pond will be constructed using the same design parameters. The Supervising Scientist believes these proposed design parameters are consistent with best
practicable technology.