Nearly 60 speakers addressed a public hearing at the WIN Entertainment Centre on Tuesday, most expressing strong opposition to the proposal, amid fears of its potential impact on Sydney’s drinking water catchment.

At a public rally, held before Tuesday’s hearing, nearly 30 people gathered with placards and cups of water, in a sign of public discontent with the proposal.

An emotional Illawarra Residents for Responsible Mining spokeswoman Kaye Osborn told the rally the plan was simply unfair.

‘‘It’s just not right in this day and age,’’ she said.

‘‘The PAC needs to reject this proposal to help protect the highly sensitive area of Sydney’s drinking water catchment ... otherwise, we can expect ongoing problems for our environment’’.

National Parks Association Macarthur branch spokeswoman Julie Sheppard agreed, but was not optimistic about their efforts.

‘‘Personally, I don’t think [the hearing] will make a great deal of difference,’’ she said.

‘‘I think the government has looked at the economic considerations of the project ... they don’t have to think about the environment.

‘‘It’s death by a 1000 cuts really, and it’s death for our catchment - we really need a change in government policy for anything to change’’.

The public hearing was part of the Planning Assessment Commission’s (PAC) independent review of the project, which was given the green light for approval by the NSW government in December last year.

Wollongong Coal, formerly Gujarat NRE Coking Coal, had requested permission to expand operations to its Wonga East area, seeking to extract coal from eight new longwall mines.

The proposal would allow mining under a large section of protected catchment area, including much of the reservoir behind Cataract Dam, which supplies drinking water to Wollongong and Sydney.

The planning department noted its backing was at odds with various government policies but said it was confident Wollongong Coal could adequately mitigate environmental risks.

The plan was met with a flood of concern from environmental outfits, residents and Wollongong City Council, about the effects of mining on the coastal swamps and the catchment.

Following dozens of submissions to the planning department, the minister, Pru Goward, ordered the PAC to review the application.

She asked commissioners to pay particular attention to the project’s potential impact on upland swamps and water resources, along with noise and air emissions to nearby homes.

Illawarra Business Chamber CEO Debra Murphy was one of the few people who spoke in favour of the expansion, noting its economic value.

She told the PAC that mining had been a long-standing part of the region’s economic fabric and still had a place in its future.

While she wasn’t surprised to be one of the soul supporters of the project at Tuesday’s hearing, she asked the PAC to weigh the expansion’s economic benefits with concerns about the environment.

‘‘The decision needs to be made on balance,’’ Ms Murphy said.

‘‘We’ve been mining in the area since 1849 and we still have a beautiful environment.

‘‘We didn’t have environmental controls and management plans in place back then; now there’s a lot of controls in place that organisations have to comply with, there’s a lot of regulations on them ... they’re in a better position because there’s better protection systems in place’’.

Ms Murphy said she was concerned about any job losses that may stem from the PAC’s rejection of the project, fearing workers would have to look interstate for employment.

Wollongong Coal chief operating officer Dave Stone said the miner acknowledged concerns about the potential environmental impacts but had refined the proposal to ensure its ongoing protection.

“The mine is 11km from the Cataract Reservoir Dam Structure with no longwall mining permitted in its regulated buffer zone,’’ he said.

‘‘Detailed studies demonstrate that less than one per cent of the water entering the mine is potentially coming from the reservoir catchment.

‘‘We can assure the community that there is a negligible effect on the quality or quantity of water entering the reservoir.”

While he noted the PAC’s refusal of the project would not spell the end for the Russell Vale mine in the short-term, he said the miner would need to assess all its options.

He could not rule out job losses, noting it was something the company would have to consider.

The PAC review is set to be completed by March 20.