It will be at least another 18 months before any noticeable improvements in air quality can be measured in towns like Alexandra, Otago Regional Council environmental information and science director John Threlfall says.
Alexandra, Arrowtown and Cromwell are in airshed one - the area judged to have the greatest air quality problems and as a result of that status were subject to stricter controls in an effort to meet national guidelines.
The National Environmental Standard (NES) requires, by 2013, the average daily PM10 level does not exceed 50mcg per cubic metre in a 24-hour period more than once a year.
To help towns like Alexandra meet the standards, the Clean Heat, Clean Air project aimed to encourage residents to install clean heat appliances and insulate homes.
However, Dr Threlfall said as the homes that had taken up the programme were scattered throughout the town and the air quality monitor was in one spot, it was difficult to measure any change.
"The monitor is not showing any improvements."
In the past 12 months 135 homes had had clean heat appliances installed and 200 were insulated.
Another factor, was that many putting in new heating appliances continued to put in log burners, though those were models that met the clean heat guidelines, he said.
"The smoke isn't going away completely."
On January 1, 2012, all heating appliances in Alexandra that did not meet the emission rate of less than 1.5g/kg would become prohibited.
Until then old appliances continued to be used, he said.
"That will be the big change."
This winter the air quality had not deteriorated any further, he said.
A PM10 monitor has just been installed in Lawrence, adding to the eight at other sites around Otago.
