An Independent Planning Commission (IPC) hearing has been told approving a controversial mine would "sell the soul" of a rural community "for a few pieces of silver".

The Bowdens Silver Project at Lue, about 25 minutes east of Mudgee, is being examined by the NSW IPC at hearings over the next three days. 

Discovered in the 1980s, it is Australia's largest undeveloped silver deposit, with the company also planning to extract lead and zinc over a 23-year mine life span. 

About 100 people, joined by more than a dozen tractors, were in Mudgee this morning to raise their concerns about lead poisoning and contamination if the mine was allowed to go ahead.

Year 11 student Abigaelle Mills told the hearing this afternoon her family had lived and farmed near the proposed mine for 130 years.

She described the Lawson Creek, which sits near the site, as the "lifeblood", and said she had "deep concerns it's going to go catastrophically wrong".

"We are virtually selling our souls for a few pieces of silver," Ms Mills told the commission.

Earlier, Macquarie University honorary professor Mark Taylor gave evidence on the risk of lead, of which there is no safe level, he said.

"My assessment is that dust will be the key for exposure, and this site will be dusty," he said.

He argued "negating off-site impacts has never been achieved anywhere."

Other experts today have criticised the data, statistics and methodology used by the mining company to predict its surface water usage, impact on groundwater and risk assessments.

Professor Taylor said the available water resources would not be sufficient to suppress the risk of lead  dust. 

Earlier, commissioners heard from the Department of Planning and Environment (DPE), which last year recommended the project be approved.

DPE spokesman Steve O'Donogue said it "will achieve balance, between maximising resource recovery and minimising associated impacts on surrounding landholders and the environment through best practice contemporary practices and mitigation measures."

But mining engineer Michael White disagreed.

He told the hearing there were serious concerns around the proposed management of acidic water, known as acid mine drainage (AMD).

"The proponent has not identified … any other mine sites where the use of this design and technology at this scale has been successfully employed in either the short term or the long term," he said.

The hearings followed a protest organised by the Lue Action Group, which saw around 100 people and more than a dozen tractors drive through suburban Mudgee before today's hearing started.

The group's president Tom Combes said they were fighting because an open-cut lead mine was being planned in the heart of the Lawson Creek Valley. 

"It's right in the middle of all of that agriculture, right in the middle of all of the tourism, right in the middle of an area that is just riddled with people," Mr Combes said. 

The group is particularly worried about the health impacts on about 20 children at the Lue Primary School, two kilometres away from the mine site.

'Benefits outweigh risks'

Health assessments conducted by the company found the project presented no health risks to the local community, including from water and air quality, dust or mining emissions. 

About 400 submissions made during the exhibition period opposed the proposal, meaning the Independent Planning Commission had to step in to make a final determination on whether or not it went ahead.

The owner, Silver Mines Limited, said the project had a potential economic benefit of almost $150 million.

Bowdens Silver's managing director Anthony McClure said any development has its opposition. 

"Overall we have really strong, healthy community support," Mr McClure said. 

He said it was a silver mine which has by-products of silver and lead, and health impacts from the operation have been ruled out in its assessments. 

It said 320 jobs would be created during construction and there would be more than 220 ongoing positions, which the company said were prioritised for locals. 

Bowdens Silver said with coal mines in the region coming to the end of their lives it would fill a void in the workforce.

The hearings conclude on Friday.