Capital landfill bills set to rocket

Wellington ratepayers may face a rise of up to 15 per cent in tip charges over the next two years if the city does not cut back hard on its landfill usage.

New rules due to come into force under the Emissions Trading Scheme (ETS) could see Wellington City Council’s liability costs for landfill greenhouse gases increase almost sevenfold, from $176,000 to $1.4 million, by 2019.

If that extra cost cannot be reduced, rates could go up, and residents could face higher gate fees at landfills, as well as restrictions on the amount of green waste they are allowed to dump.

Councillor Iona Pannett admitted it was a powerful incentive to cut waste. ‘‘There’s a really strong economic driver to fix the way we do our waste, because it’s going to cost us significant amounts of money if we don’t resolve the issue.

‘‘If we can manage to divert a large amount of organic waste, and come up with a solution for sewage sludge, a large part of this problem will go away.’’

Late last year, it was revealed Wellington households were among the worst recyclers in New Zealand, and sent almost twice as much waste to landfills as homes in Christchurch.

Council waste operations manager Adrian Mitchell gave an assurance yesterday that all practicable steps would be taken to limit emissions, and reduce the likely bill.

There were two main ways to cut the liability costs, he said: by capturing more gases, or diverting more organic waste.

The leap in costs is down to changes to the ETS, which is intended to force emissions cuts and penalise local authorities for continued use of landfills. Under the ETS, councils must cover their emissions by buying carbon credits. One carbon credit is the equivalent of one tonne of carbon dioxide. Methane, the primary gas emitted from landfills, attracts a higher penalty because of its more powerful greenhouse effect.

Mitchell said two events had triggered the sudden increase in landfill costs.

The first was a requirement introduced in 2015 to buy only New Zealand carbon credits, restricting access to international, and possibly cheaper, markets.

Before 2015, councils could buy international credits for as little as 18 cents a unit, and the average was about $5. Now the going rate is about $16.50. ‘‘In February this year, carbon credits were over $18 each,’’ Mitchell said.

The second trigger was a central government decision last year that saw a gradual fall in discounts offered.

Previously, only half of landfill emissions had to be covered by carbon credits. By last January, twothirds had to be covered, and this will rise to 83 per cent from January 2018, and 100 per cent from January 2019.

Mitchell said the amount of waste arriving at landfills had been steady in recent years, despite population growth, largely because of residents’ awareness of recycling and composting schemes.

In order to capture more landfill gas, the council would need to invest in better collection systems, and consider installing a second electricity generator on site to convert methane to electricity.

A generator in operation at the Southern Landfill, between Brooklyn and Owhiro Bay, is already operating at capacity, and powers the equivalent of 1000 homes, converting methane into carbon dioxide in the process.

‘‘If we continue with the same theoretical emissions from our site as we are now, we will face that $1.4m liability, and that’s why our actions are all about reducing,’’ Mitchell said.