A bulldozer in action at the Redvale Landfill and Energy Park, at Dairy Flat, Auckland. Photo / Cameron Pitney
Auckland’s biggest landfill would need to stay open for seven to eight years longer than expected under a favoured proposal to help ensure the region’s waste can be adequately managed until a new facility is operating in the mid- to late-2030s.
The proposal to keep the Redvale landfill – which has been earmarked for closure at the end of 2028 – open until 2036 is likely to be contentious for some neighbours of the Dairy Flat facility.
But Waste Management New Zealand, whose plans for a new Auckland Regional Landfill at Wayby Valley – between Wellsford and Warkworth and adjoining Dome Valley – have been subject to prolonged legal and court action over consents, says keeping Redvale open until 2036 is, in the view of new analysis, the best tide-over option.
“Auckland faces an upcoming infrastructure challenge,” says the company, in a consultation document released today.
The proposal is not final; the company is seeking public feedback.
“Redvale Landfill & Energy Park, which currently manages approximately 50% of Auckland’s waste (around 600,000 tonnes annually), will stop accepting waste at the end of its consent in December 2028.
“Although WM New Zealand is actively developing the Auckland Regional Landfill (ARL) as a permanent replacement, a significant timing gap exists.
“The ARL, which is still progressing through the consenting process, isn’t expected to be operational until the mid-2030s. This creates a critical 7-8 year period where Auckland needs reliable, sustainable solutions for managing its residual waste.”
Waste Management said it had considered four options including identifying a new, temporary landfill and alternative technologies such as incineration or mechanical biological treatment.
But maintaining Redvale was judged the most viable solution based on seven criteria in an independent analysis by Tonkin + Taylor, along with focusing on ensuring Aucklanders minimised waste as much as possible.
This recommendation would make “efficient use of existing infrastructure while supporting Auckland’s long-term waste reduction”, said the consultation paper released today.
The Redvale landfill, which started operation in the 1990s, is a long way from the dumps and tips of New Zealand folklore, as Waste Management leaders were at pains to point out to the Herald during a visit to the site.
Where once householders might roll up to a tip with a trailer-load of trash - and forage around for “treasure” to remove – these days, a site like Redvale is carefully managed, monitored and used as an example of an environmental wonderland.
Around 200-250 trucks roll in each day, with about 1800 tonnes of rubbish. The facility takes about half of all the landfill waste produced by Aucklanders.
Unlike the tips of the 1970s and 1980s, Redvale Landfill and Energy Park is highly engineered – the clue is in its name.
About 95% of the methane gas produced by the waste is captured and converted to electricity. Redvale is, says Waste Management managing director Evan Maehl, the ninth biggest gasfield in New Zealand.
He says Redvale, which started operating in 1993 under the then requirements of the Resource Management Act, was a pioneer in leading the change from the “bad old days” when New Zealand had more than 1000 tips and dumps in operation.
“One of the game changers was the ability to build infrastructure in that gas collection space,” says Maehl.
He said emissions from class one landfills in New Zealand had been cut by about 50% between 2005 and 2022. “That’s a combination of closing the old ones and putting good gas capture [in place]. The old scrubby ones that you and I used to go to had no gas capture whatsoever.”
The Redvale site - which is now one of only about 40 class-one landfills left in New Zealand – is 160ha in total, of which 56ha is permitted for waste.
As bulldozers moved over the Redvale site last Wednesday, odour-diminishing spray machines were in full action.
Senior engineer Jim Jefferis, Waste Management’s head of environment and consents, described the Redvale landfill as a “bio-reactor” because of the level of renewable energy, powered by on-site generators, that it was producing.
Despite the obvious environmental improvements over the years, Waste Management is expecting to receive strong feedback from the community over the recommended proposal to keep the landfill open for another seven to eight years.
There is a need to manage a total of about four million tonnes of waste between the expected closure of Redvale at the end of 2028, until the likely opening of the ARL in 2036. It has to go somewhere, says the company.
Waste Management says its recommendation to keep Redvale open is based on an independent assessment by Tonkin + Taylor that took into account timing, consenting, the economic impact, resiliency, environmental, social and community impacts and emissions.
The company looked at four options in total, including identifying a new landfill, until the ARL opened.
“Finding a suitable site, obtaining resource consent, and completing construction is a complex and time-consuming process, often taking many years,” says the consultation paper.
“Landfills are typically long-term investments, designed to operate for several decades. This long lifespan helps distribute the costs over the lifetime of the landfill. If a landfill were only required for a short period (such as eight years – 2029-2036), the investment required may be hard to justify.”
The company says its plan to keep Redvale open for longer, while also striving to reduce waste and recover more, is a recommended course of action, but not necessarily the final one.
Among its key considerations, it says, is “understanding community impacts such as traffic, noise, dust, odour and visual effects arising from the increased consented disposal capacity between 2029-2036″.
“The combined approach prioritises Auckland’s continued focus on waste reduction and recovery capabilities while acknowledging the ongoing need for landfill disposal,” says the consultation paper.
“By continuing to support Aucklanders’ efforts to reduce waste and exploring opportunities to enhance recycling infrastructure, we can progressively reduce the volume of residual waste requiring landfill disposal.
“Simultaneously, rebalancing disposal across existing landfills provides the necessary disposal infrastructure for materials that cannot yet be recycled or recovered, ensuring essential waste management services continue uninterrupted as we transition to ARL.”
Consultation opens today and closes on May 11. As well as the four options already studied, the consultation paper leaves open the possibility that parties might have other options that need to be considered.
Editor-at-Large Shayne Currie is one of New Zealand’s most experienced senior journalists and media leaders. He has held executive and senior editorial roles at NZME including Managing Editor, NZ Herald Editor and Herald on Sunday Editor and has a small shareholding in NZME.
The plans failed to meet tests under the RMA, the commissioners' report said.