A first-in-New-Zealand approach to industrial air quality assessment

Daiken Southland Limited has operated a medium-density fibreboard (MDF) manufacturing plant at Pioneer Highway, Mataura since 1997, producing around 200,000 m³ of MDF each year.  PDP recently helped Daiken secure renewed resource consent for its air discharges.

Throughout its operations, Daiken has built a comprehensive air quality monitoring record, covering emissions and ambient levels of PM₁₀ (tiny particles of 10 micrometres or less) and formaldehyde.

The usual assessment approach in New Zealand for a plant of this size and type would be to measure emissions and use a model to calculate ground-level contaminant concentrations. However, in our work for Daiken, we found that the most effective and efficient assessment method was to review, analyse and present the story captured by Daiken’s extensive air quality monitoring dataset.

This enabled us to prepare the resource consent application and assessment of environmental effects using existing compliance monitoring information, rather than through additional emissions and dispersion modelling. This was the first time we are aware of in New Zealand that an air quality assessment for a large industrial operation has been based entirely on consent compliance monitoring data.

Environment Southland’s independent air quality expert reviewed our assessment and fully accepted our methodology and findings . As a result, no request for further information was issued and the application was processed without notification.

The new resource consent has been granted for a period of 25 years, with refined air quality monitoring requirements. Emissions monitoring is no longer required, ambient air quality is now monitored for PM₁₀ in real time rather than through 24-hour gravimetric measurements, and a new, more automated method for monitoring ambient formaldehyde monitoring is now made possible.