A total of 19 complaints about the smell coming from Wanaka's $21.5 million wastewater treatment facility Project Pure have been lodged with the Otago Regional Council this month.
The figure, released to the Otago Daily Times on Tuesday, equates to one complaint per day about odour emanating from the sewage treatment plant located near Wanaka Airport.
ORC environmental services manager Martin King said 52 odour complaints had been lodged since Project Pure - the Queenstown Lakes District Council's biggest infrastructure outlay - became operational in January 2009.
Odour complaints during July have surged, compared with a total of 14 complaints lodged during May and June.
The regional council's tally of odour complaints does not match figures the QLDC provided to the ODT, which excluded the July total, last week.
QLDC wastewater manager Martin O'Malley said he was aware that more complaints were being made to the ORC than to the council or the plant operators.
"The figures provided last week were the ones we were aware of. If the complaints do not come directly to the plant or QLDC, then we cannot report on them, hence the difference in figures," he said.
QLDC figures had a total of 24 odour complaints since January 2009 and five made by a Project Pure neighbour during the month of June.
"Proactive ongoing monitoring" is continuing at the site of Project Pure, Mr King said.
"We are almost at the point where we can differentiate between certain odours. It is very important to have a consistent approach to how we do the monitoring" he said.
A report was "anticipated", although Mr King could not specify when it might be completed.
Project Pure neighbour Aaron Heath said odour from the treatment plant had become more noticeable during the past few months.
Climatic conditions since the start of winter might be influencing the prevalence of odour concerns, he said.
"I don't know if the problem has got worse; it has just become more evident," Mr Heath said.
At a Wanaka Community Board meeting last week, Mr Heath alleged council officers were either "naive" or misleading the media and public in regards to the numbers of complaints being made about odour from the treatment plant.
Project Pure has been issued with one infringement notice - last October - for failing to comply with resource consent conditions pertaining to odour levels since it became operational, Mr O'Malley and Mr King said.
