Clearing the air

A chimney billows smoke in Invercargill, contributing to the city’s poor winter air quality.
A chimney billows smoke in Invercargill, contributing to the city’s poor winter air quality.

Strict new air quality regulations mean significant changes are in the wind for Southland residents. Alex Fensome finds out what the new rules will mean and how organisations are preparing. 

Down on Pomona St in south Invercargill there's a metal cylinder that measures air pollution.

Every day, an Environment Southland scientist changes the filters they put in the day before, pure white sheets of thin paper.


The darker the filter is when it comes out, the worse the pollution has been.

Seeing the filters makes you realise how filthy Invercargill's air actually is. In a day, they have caught enough particles to turn solid black.

Long after they have been stored, in a climate-controlled archive room, the stench of smoke and soot clings to them.

That is what we are breathing into our lungs every day in winter. Millions of tiny particles, clogging up our tubes, coating them in grime.

It's a nightmare for asthmatics and anyone with respiratory problems, and an inconvenience for everyone else.

Nathan Surendran moved to Invercargill from Britain two years ago, with his wife and two young children.

Living in south Invercargill he noticed the difference the first time his daughter caught a cold.

"My daughter seems to have suffered from coughs of unusual duration and severity, when I compare them to memories of similar illnesses that my son suffered when he was in the same age bracket," he says.

"He's now 4, and he has also suffered from some lingering coughs in the last two winters that we've been in Invercargill that are longer."

South Invercargill is the main trouble spot.

"There is a noticeable smell of coal smoke in the air in those areas on most cold days, and often a smoky haze," he says.

Home burners are belching pollutant PM10 particles into the air throughout winter, but many businesses and facilities also rely on polluting coal boilers - and there is no cheap way to replace them.

Mr Surendran lived in East Hertfordshire, near London, before he emigrated. The average yearly level of PM10 there is 14-21 micrograms of particles per cubic metre. Last year's average in Invercargill was 22mcg/cum. In Gore, it was 23mcg/cum.

Those figures and the black filters are a stark reminder New Zealand's clean image isn't really borne out in our cities - Invercargill's air is worse than that on the outskirts of one of the biggest cities in the world.

Successive governments have known that, and now Invercargill is running on a deadline.

We must clean up our air by 2016.

Within four years there must be only three breaches of air quality standards. By 2020, there can only be one.

Those are the goals set by the National Environmental Standards for Air Quality. If the region does not achieve those targets, economic development will suffer - it will make it hard to set up a factory or other emitting business until the target is met.

The Environment Ministry is prepared to intervene to ensure the standards are met - even to the extent of appointing commissioners in place of the regional council to do it. It's written in their compliance strategy.

If it's not met, new industrial development could be refused consent - potentially a drain on the economy of the city.

But can we, down in the south, switch to clean heat before 2016?

Measures to make sure that happens are being considered by Environment Southland.

Everything from banning coal entirely to incentivised rates schemes is being considered. It is not easy.

Homeowners are already encouraged to move away from coal and wood, but it's a slow process.

The Energy Efficiency and Conservation Authority offers grants for heat pumps, but they are only available once a house is fully insulated, which is itself a challenge for the pocket.

The Southland Warm Homes Trust offers another set of grants and funding, but they are also limited by financial resources.

Lignite, soon to be Gore's economic saviour, is not the answer. Solid Energy's briquetting plant, which should produce 90,000 tonnes of briquettes, will only sell 3000 tonnes to the home heating market.

In any case, lignite burns dirtier than coal, and burning it isn't Solid Energy's end game for their Eastern Southland venture - they want to make fertiliser and biodiesel.

John Fry is the chief executive of Yunca, the famous Southland fire maker. He feels it is possible to produce a clean-burning coal fire by 2020, but that it will be an expensive process.

The company has just released a clean wood burner that meets Otago's strict air standards (the Otago Regional Council banned inefficient wood burners and multifuel fires in January).

But it took years of development to get to that stage, he says.

Yunca is trying to move with the times, trying to improve efficiency, but Fry feels the Government is overlooking the reliability of coal and wood - and their cheapness.

For some people, electricity simply won't be an economic possibility. Prices are rising all the time, and, as he says, a metre of wood has been $60 for as long as anyone can remember.

Finding a cheap way to heat large buildings without coal or lignite is another challenge.

Even Environment Southland, responsible for monitoring and regulating air quality, heats its Waikiwi buildings with a coal-fired boiler.

It began looking to change in 2006, but found no alternative was cheaper.

Its acting chief executive, Graham Alsweiler, said a replacement was planned for 2013-14.

The Invercargill City Council's parks and reserves division was one organisation that has switched from coal.

Its nursery boiler now runs off waste wood collected during park maintenance.

Head nursery worker Warren Larby says the old boiler produced large quantities of ash and went through eight tonnes of coal a fortnight.

The new boiler produces a wheelbarrow load of ash a week - much less than the previous model, he says.

However, Larby says a similar system would not work for everyone.

"Not every other place could use the sort of material we use," he said.

Another council facility to switch was Splash Palace, which changed from lignite to a woodchip boiler, aimed at reducing emission of particles and the cost of heating.

A report into the change told the city council in April it would cost $20,000 more to use woodchips rather than lignite, but would be cleaner and, in the long run, cheaper.

Surendran's interest is more than personal experience with his children. As an engineer at Invercargill-based EIS Energy, he is an expert in heating systems and energy audits - it was his work which convinced the council to switch Splash Palace to wood chips.

He worked out the switch would reduce PM10 emissions by the equivalent of 200 coal burners.

Wood chips have less than half a per cent ash content - compared with 5 per cent or more for coal and more than that for lignite.

Asked if it is possible for Invercargill to meet the standards by 2016, he is blunt.

"Probably not, to be honest," he says.

He says coal is not always the cheapest way to heat large buildings, let alone houses, and there are hidden costs which coal burners accrue.

Mr Surendran calculates an internal rate of return based on future fuel cost, longevity and other factors.

He predicts the price of lignite will rise as it is mined in Eastern Southland.

In a piece of work for Environment Southland, he showed a wood chip boiler would have a 25 per cent better return than a new coal burner.

"Projected carbon prices under the ETS, future transportation costs and the impact on fuel price are both large uncertainties in this calculation," he says.

An external cost of using coal is its emissions - nasty PM10 and gases containing sulphur and mercury.

Mr Surendran says it is difficult to quantify the public health effects - although research is ongoing - but the link between air pollution and hospitalisation rates is well established.

But there are problems with conventional clean heat.

"Heat pump systems have a design life of seven to 10 years," Surendran says, "And so in the lifespan of a hot water boiler system they would have to be replaced three to four times, with the capital cost and service disruptions that implies."

He says there are ways all of us can work to improve air quality.

The best way to reduce emissions from home burners is to reduce the amount of heat being lost, so the amount of fuel you need to burn is less.

Many people have taken advantage of EECA grants to get floor and ceiling insulation, despite the economic burden, but windows cause much heat loss too.

There are relatively cheap - "we're talking tens of dollars" - films and tapes which can be put across windows to mimic the effect of double glazing.

New ways of heating will also have to be considered for other buildings - the majority of schools have coal-fired boilers to heat classrooms.

Southland Girls' High School principal Yvonne Browning says she would love to find an environmentally friendly way of heating the buildings but simply cannot afford to.

Unless a cheaper way became available, it would need substantial increases in funding to switch from coal, she says.

"Schools are on a fixed budget. We are an EnviroSchool and we are conscious all things we do affect the environment . . . you can't have girls or teachers working in a cold school."

Surendran says the Ministry of Education has not been well informed about heating options for schools.

Too often, boards of trustees decide to install heat pumps, if the coal boiler needs replacing, because they are so heavily promoted and they are familiar with the technology, he says.

Meanwhile, the city's people will continue to cough and wheeze their way through winter, and the stench of coal smoke will remain ubiquitous.

Invercargill is not going to go clean overnight. It might not even go clean by 2016, or 2020. It's going to take a shift in the way we look for warmth, the way we treat our houses and the way we afford those things before the smelly smog of winter can be banished.

Air quality is measured by the number of PM10 particles per cubic metre of air over 24 hours.

PM10 are small solid or liquid particles in the air, produced by burning solid fuels. Each particle is one-fifth the diameter of human hair.

PM10 is easily inhaled and can cause irritation of eyes, throat and lungs. It poses a particular risk for asthmatics, the elderly and people with chronic lung conditions.

A 2007 study estimated that 1100 New Zealanders die prematurely from air pollution in urban areas each year. Levels of an average of more than 50 micrograms per cubic metre for more than 24 hours breach National Environmental Standards.

By July 20, there had been 15 breaches in Invercargill this year.
Source: Environment Ministry, Environment Southland

The Southland Times