Canterbury unlikely to meet air quality standards
A crackdown on home heating has not been enough to bring Canterbury's air quality up to soon-to-be introduced national standards.
Despite a long-term improvement in the region's air quality, it is on track to fail national air quality requirements which come into effect in September.
If the standards had been in place this year, half of Canterbury would have failed by the third week of winter.
If it does fail, the region is unlikely to be punished – the Ministry for the Environment said it would only intervene as a last resort, and it was reviewing the standards which could mean they are changed.
From September 1, most of Canterbury is allowed three "high pollution nights" each year. From 2020, it will reduce to one.
Despite an unseasonably warm winter, most of Canterbury's major centres have experienced many high pollution nights.
In smoggy Timaru, there have been 19 "high pollution nights" this year.
Christchurch, Kaiapoi and Rangiora have all exceeded three nights of high pollution.
Parts of the West Coast, Otago, and Nelson are also likely to pass the mooted standards before the end of winter.
It has raised questions about their suitability, particularly for cold, southern towns reliant on home heating.
Environment Canterbury (ECan) has spent millions trying to improve air quality to meet the requirements, largely by cracking down on home heaters.
It banned home wood burners over 15 years old in some areas and employed "smoke spotters" to monitor smoke from residential chimneys.
Air quality had improved throughout the region since 2001, with a substantial decrease in high pollution nights, said ECan spokeswoman Katherine Trought.
"Canterbury is making good progress in a number of the polluted airsheds to reduce the number of high pollution nights," she said.
"We have continued to see improvement in winter air quality across Canterbury."
Canterbury still had "a lot of work to do to meet the government-set targets", but the region was moving in the right direction, she said.
It had not given any abatement or infringement notices for non-compliant burners, but had issued warning letters.
Parliamentary commissioner for the environment Dr Jan Wright questioned whether the national standards were still appropriate in a report last year.
She said levels of PM2.5 – smaller and therefore more damaging particulate matter – were more important to measure.
Her comments prompted a review of the guidelines, which is under way.
A Ministry for the Environment spokesman said the review was ongoing. There had been "significant improvements" in air quality across most of the country since the standards were introduced, he said.
Environment Minister Dr Nick Smith could punish councils for failing to meet the standards, but there was "a very high threshold for the minister to intervene, and all other reasonable options would be exhausted".
Canterbury medical officer of health Dr Alistair Humphrey said the rules were tough, but they should be, as poor air quality had severe health implications.
"It's a tough call for local government to achieve those targets, but when you think how many people are affected, it's certainly something they should be pressing for," he said.
"They're difficult to meet, but we have hundreds of people a year dying from poor air quality."
The long-term improvement in Canterbury's air quality was "a very good news story", he said, but there was more work to do.
"In Christchurch we've done really well, but we need to do better."