The source of the obnoxious odour was aired for the first time in Lithgow Council at this week’s meeting but there was no satisfactory conclusion.

When Tom Fitzgerald reflected the view of some residents that this was chicken farm waste from somewhere he was assured it was no such thing, despite presence of what was claimed to be feathers and chook poo among an assortment of other unsavoury material.

“There’s even an old plastic bucket among it,” he said.

The source of the pong is no mystery; it’s coming from an ever growing mass on private property at Williwa Creek.

It’s the content and its source that’s the puzzle.

“There’s even suspicion that this is waste being brought in from outside our area,” Mr Fitzgerald said.

Mr Fitzgerald and affected landholder George Gates told the Mercury this week that the dumping of the offensive material had been increasing over the past three weeks and they estimated the mound to now contain several hundred tonnes.

He said residents had been told that it was ‘paper waste’ but this was an absurd claim.

They’re concerned not only about the smell but the impact on streams in the area that eventually empty into the Turon River.

Another resident, Patrick Walsh, said the offensive smell was a worry, particularly as he has three streams on his property that he fears will become polluted.

“If they’re telling us this stuff is in no way hazardous then I want them to put it in writing,” he said.

Mr Walsh said that he had been promised an inspection by council rangers this week and would await with interest their findings.

Residents said they had been told that the EPA had approved the dumping on the site but had been vague on what the material contained.

“In any event they can’t have that smelling up the place,’ Mr Fitzgerald said.

“As the mound gets bigger it will just get worse.”

Mr Fitzgerald correctly claimed that the public has a right to know just what is being dumped in its area.

He raised the issue during public forum at this week’s meeting and said trucks were dumping the offensive material on the site ‘on a daily basis’.

The meeting was told the suspicion was that the material was coming from the chicken farm at Pipers Flat which was also the subject of complaints at the meeting regarding odours.

But Mayor Maree Statham said she was aware of the issue at Portland and ‘it was not from the chicken farm’.

Council’s Environment and Development Manager Andrew Muir said he was ‘generally aware of the issue’ and would meet with Mr Fitzgerald.

He too said the issue was not related to the Pipers Flat chicken farm.

But neither he nor the mayor elaborated and that has just added to the mystery in the air at Portland.