Burning issues aired
Richmond’s air pollution has breached national standards four times this year.
Since September last year the National Environmental Standards for Air Quality require that there be no more than three high pollution nights per year. By 2020 only one breach will be allowed or councils will face limits on the resource consents they can issue.
In 2016 there were five air pollution breaches in Tasman, three in 2015 and two in 2014.
Tasman District Council communications manager Chris Choat said a new air standard was going to be released next year and the council would ‘‘take the opportunity to review our rules at that time to ensure we meet the new requirements’’.
Choat said non-compliant wood burners in Tasman didn’t need to be replaced with a compliant version unless a house was sold to a new owner. Since 2007 there had been 570 compliant wood burners installed in Richmond.
Nelson, which brought in strict controls on woodburners several years ago, has only had one air pollution breach this year, on March 20.
Nelson City Council communications manager Paul Shattock said the exceedance appeared to be ‘‘highly unusual’’ and could be a ‘‘possible fault with equipment’’.
Shattock said 66 ultra low emission burners had been installed in Airshed B2 (Stoke) and 77 in Airshed C (the Brook/ Maitai/Central/Nothern City Area).
Is it smoke or steam?
Residents often question what is in the highly visible plumes above two wood Nelson processing plants.
Nelson Pine Industries managing director Murray Sturgeon said the exhaust emitted from the plant’s dryers is moisture that has been dried out from the wood fibre as part of the manufacturing process.
‘‘It does not contain any impurities and is resulting from drying the fibre from 130 per cent moisture down to 15 per cent moisture that is required in the process,’’ he said.
Sturgeon said the plume that can be seen coming from the plant is the result of the hot air temperature required in the drying process meeting the ambient air temperature. The direction in which the plume went depended on the wind direction.
‘‘The plume dissipates approx 50 metres from the exit point of the dryer, and disappears when the temperature blends with the ambient temperature of the day.
‘‘On a very hot summer conditions the plume is hardly visible.’’
Sturgeon said Nelson Pine Industries had been operating under local authority consent conditions which were monitored frequently.
‘‘In the 30 years of operation the conditions have never been breached.’’
The South Pine plant in Annesbrook operates under a discharge to air resource consent, effective until 2026 .
General manager Darryn Adams said the first stage of the consent included installing a ‘‘wet scrubber’’ which washed particulate from the exhaust gas from the company’s first heat plant to meet required levels.
‘‘We only burn clean sawdust and shavings,’’ he said. As part of the second stage of the resource consent the emission control system of South Pine’s second heat plant had to be upgraded. New equipment, using cyclones to separate particulates, would be operating early next year.
Another visible emission site are the boilers at Nelson Hospital. Nelson Marlborough Health facilities manager Allanagh Rivers said two of the three boilers ran on coal and the third used landfill gas piped from the York Valley tip.
The boilers operate continuously to generate steam used for heating all the main buildings, cooking meals, sterilising equipment and doing the laundry.
‘‘The emissions from the boilers are filtered prior to release. They are well under the Nelson Marlborough Health resource consent parameters and are monitored frequently,’’ Rivers said.
She said the steam did not contain chemicals.