Pizza ovens suggested as pollution culprits

Wanaka's pizza ovens could be in the firing line after a study found air pollution peaked in the ''restaurant area'' of the town in early evening.

Results of an intensive air quality study of Wanaka and Arrowtown, undertaken by the Otago Regional Council, were released at a council technical committee meeting this week.

Council air quality scientist Deborah Mills said the studies aimed to identify the ''worst'' areas of air quality, confirm the suitability of the location of air quality monitors, and look at the potential of the towns to exceed the national environmental standard for air quality which required PM10 (very small particulates) levels not to exceed 50mcg-per-cubic-metre levels more than once a year.

In Wanaka, an air zone 2 town, the study found there were some localised areas were PM10 was elevated for relatively short periods of the day, she said.

''It was observed between 4pm to 5pm there was a noticeable start-up of restaurant emissions.''

One of the higher evening readings was taken in Ardmore St in a commercial area where restaurants and bars predominated, she said.

Cr David Shepherd said the council should probably be mindful the number of pizza ovens in the area could be part of the problem, as they were wood-fired, and there were extraction fans cranking up at that time.

Council engineering, hazards, and science director Gavin Palmer said the council would be targeting its education and communication to the specific behaviour in that area.

Ms Mills said in the residential area, moderate concentrations of particles were recorded which cleared relatively quickly due to persistent off-shore breezes.

While there were times and places PM10 was elevated it was considered unlikely the national standard would be exceeded under normal winter conditions.

In Arrowtown, the PM10 levels were consistently high in the eastern part of the town with burner age, fuel use and topography contributing to the high levels. The council had moved its air quality monitor from the school to that area as it was required to under the NES to monitor the ''worst'' air quality.