The South Coast Neighbourhood Society (SCNS) is spurred by environmental worries, while the airport is concerned about the impact birds attracted to the landfill could have.
Independent commissioners approved the Dunedin City Council’s resource consent application for the landfill last month.
In a 137-page decision, they determined the public health risk at nearby Brighton was acceptable, concerns raised by the airport around bird strike had been addressed, and community concerns around a lack of consultation were met through the information presented at the hearing.
While the council asserts the landfill will be operated "safely and responsibly", the SCNS remains firmly opposed.
Appeal leader Sarah Ramsey said people were "very upset" and "bewildered" that consent had been granted.
They were rallying to raise funds for the appeal.
A concert is planned for later this month.
She had underwritten legal costs to date of nearly $59,000, of which about half had been covered by fundraising.
The appeal would emphasise particular points, she said.
These included liner failure and bio-accumulation concerns, inadequate fire mitigations, insufficient duration of maintaining the landfill after closure, and proposed measures to eliminate the risk of attracting gulls.
The group was also concerned about the cost, especially "sky-rocketing" construction prices.
The council’s website said it expected the new Smooth Hill landfill near Brighton to start operating in 2026, and it had budgeted $56million from 2024-25 to 2028-29 for the project.
"We expect the real cost will now be well in excess of $100 million and do not see how this is a justifiable capital expenditure when there are perfectly good alternatives if the council were to consolidate and co-operate with other operators," she said.
"If this council were genuinely confident and committed to their strategies to reduce waste, then it’s glaringly obvious this landfill isn’t needed and it flies in the face of the Ministry for the Environment’s efforts to reduce the number of landfills in New Zealand through the recent landfill levy."
A Dunedin Airport spokesman confirmed the airport would lodge an appeal based on specific consent conditions relating to bird strike risk, but said the airport was also in discussions with the council and was hopeful its concerns could be resolved in the coming days.
Council chief executive Sandy Graham said the concerns of the SCNS had already been well-traversed by the independent commissioners.
"The panel decided to grant consent for Smooth Hill with conditions designed to protect the environment, surrounding residents and their properties from disruption.
"These will ensure the landfill can be operated safely and responsibly, for the benefit of our city, and are acceptable to the [council]."
The council had "the necessary budget in place" to develop the facility.
It was committed to waste minimisation and had approved budgets to develop a green waste facility, a construction and demolition sorting facility and a new materials recovery facility, Ms Graham said.
