ORC welcomes dedicated corporate approach to air quality improvement in Dunedin

Dunedin industries and institutions are responding positively to an Otago Regional Council (ORC) requirement to reduce air pollution by converting to more environmentally-friendly boilers.

ORC director of resource management Selva Selvarajah said it was well established that domestic burners have been the major cause of elevated PM10 levels, particularly in Central and South Otago but also in Dunedin.

ORC monitoring had also shown that industrial discharges have been largely responsible for smoke and smog in many built-up parts of central Dunedin.

The results of a recent ORC study of air quality trends in central Dunedin indicate that there were 12 exceedances last year-twice the average number of the past five years. All the exceedances were just over the legal limit of 50 micrograms per cubic metre of air. The highest for the year was 62µg/m3, which was one of the lowest maximums recorded over the past five years.

Dr Selvarajah said the monitoring results should be considered in the context of the positive way several Dunedin industries and institutions had responded to ORC’s encouraging them to upgrade to cleaner burning and more efficient heating and energy systems, as part of their resource consent renewal process.

The response had been impressive, with several companies and organisations either having completed upgrades to their boilers or in the process of doing so.

“The investments local organisations are making in upgrading plant is good news for Dunedin’s air quality,” Dr Selvarajah said.

Recently, Knox and Salmond Colleges have both received consent to upgrade their boilers, while Cerebos Gregg has been discussing options for a similar potential upgrade with ORC staff.

Wakari Hospital has completed a tender process for a clean-burning boiler fuelled by woodchips, which meets ORC standards, while the Otago Polytechnic has decided to replace the coal-fired heating system for its Dunedin campus with wood chip and LPG boilers.

Dr Selvarajah said the ORC consent approach to installing new or upgraded boilers did not require applicants to embark on expensive air dispersion modelling (the mathematical simulation of how pollutants disperse in the atmosphere.)

Rather, it preferred to work with consent applicants to find good technologies that reduced air emissions and worked well for their operations.