BHP Billiton Ltd acted too slow for public convenience in submitting its formal response on environmental concerns about its proposed mining expansion at Olympic Dam in South Australia.

The giant mining firm finally forwarded its statement to the South Australian government this week but the Australian Green Party is far from being impressed and called on BHP executives and SA authorities to allow a public viewing of the supplemental document.

Greens MP Mark Parnell said that the SA public waited patiently for almost two months for the BHP response to be submitted and to allow for another eight weeks to appreciate the details of the document would be far too long.

Parnell said that the whole issue attracted more than 4000 submissions, all delving on details from BHP Billiton on how it would address the environmental concerns of the outback expansion project.

Now is the time, according to Parnell, to divulge the details of document as he told ABC that "if the document is good enough to give to the government, it's also good enough to show the people who went to the trouble of making a submission."

The South Australian government has ordered BHP Billiton to look deeper on the issues hounding its Olympic Dam expansion project as questions arose on how waste, air quality, radiation and desalination would be dealt with.

The Australian Greens is demanding that the BHP response to all the issues surrounding the project be made public.

The state government is expecting that all the issues of the expansion should have been properly dealt with in the BHP document as acting SA Premier Paul Holloway gave assurance that the report would be reviewed exhaustively to check if all the environmental concerns were sufficiently addressed.

Mr Holloway said that once the government assessment is done, the report would be dutifully released to the public though SA authorities are only expected to hand down its final say on the project by the latter part of 2011.