Port Augusta Mayor Joy Baluch said it was the largest number the public gallery had seen since 1972.

Port Augusta Coastal Homes Association spokesperson Trevor Taylor addressed the council with questions for BHP Billiton regarding the proposal, which will be answered by the company by the end of May.

The meeting had long been sought by the association, which has concerns that the proposal, as part of the Olympic Dam Mine expansion project, would have detrimental effects on Port Augusta's environment.

Mr Taylor addressed the council with questions for the company, and brought with him almost 2000 names on letters of opposition and petitions.

Company corporate affairs group manager Richard Yeeles was scheduled to address council, but did not attend due to illness.

According to Mr Taylor, this was the third time Mr Yeeles had failed to attend a meeting with the association.

Company government and community relations vice president Kym Winter-Dewhirst attended in his place, replying to Mr Taylor's questions after a presentation on the project from senior public affairs advisor Anita Poddar.

Ms Poddar addressed council with a presentation that had already been given to the council and the association.

It covered the entire expansion project, including the unloading facility proposed for the shacks area on the west side of Port Augusta.

Mr Winter-Dewhirst said the presentation had not included more information on the proposed facility because the project's environmental impact statement was not finished.

"We won't speculate on a whole range of things until we have got it clear in our minds what we're doing," he said.

Mr Taylor stressed that the association was not opposing the expansion entirely, but the effects it could have on Port Augusta's environment.

"(The association) is not against the BHP Billiton proposal to expand the Olympic Dam Mine … what we are opposed to is expansion at any cost," Mr Taylor said.

"Share holder profit can never come before the environment and can never come before our children."

Through the mayor, Mr Taylor asked the company five questions:

Will BHP Billiton now give detail to this meeting as to the preferred location or the most likely position for the proposed component unloading facility?

What is the company's intention and expectation regarding dredging in the Upper Spencer Gulf?

What will the exact usage of the haul access corridor be when the importation of equipment has ceased is it the company's intention to lay a railway line on all or some sections of this corridor road to export ore from this Gulf facility?

Will there be employment growth for Port Augusta directly relating to the loading/unloading facility and the haul access corridor?

How does the company propose to manage these mammals to ensure one of their ships or barges does not run over and kill or injure one of these beautiful animals?

Mr Winter-Dewhirst said that while he could answer all the questions at the meeting, he gave a personal undertaking to ensure they were all answered.

"We're not proposing any dredging," Mr Winter-Dewhirst said.

"If we have given an undertaking not to dredge, (the facility) may not proceed at all."

He said no discussions had taken place to use the haul corridor for any purpose other than getting large items off the road.

City manager John Stephens said to The Transcontinental that while many who attended the meeting might have been disappointed not to receive any new information, they had made an impact by attending.

"Just by being there they gave a very powerful message to BHP," Mr Stephens said.

"I'm pleased that our community is being very strong."