Waste Management hopes to introduce a new unit at its Dairy Flat landfill to evaporate leachate into the air, and residents hope they will be able to have a say on the proposal.
Leachate is a mix of chemicals that seeps through a landfill and its disposal involves using landfill gas to turn the leachate into vapour, then releasing it into the atmosphere.
The company says its proposed new unit is more efficient and cleaner burning than its previous system, however some residents are worried, especially as the company wants to move the unit closer to neighbouring homes.
Whether or not the public will have a say in the proposal, currently seeking resource consent, is up to Auckland Council.
The Rodney Local Board member for Dairy Flat, Louise Johnston, has a number of concerns.
The proposed new unit has been on trial at the landfill since June last year. This included testing and monitoring. Reports attached to the consent application include an assessment of visual effects by Boffa Miskell, which states that, depending on the wind, the height of the plume can reach as high as 30 metres while at other times it will be a lot less visible. In addition, Tonkin and Taylor monitored the emission rates of key volatile organic compounds benzene, toluene and vinyl chloride, at four locations, three of which were within the landfill site, from August to November last year.
Mrs Johnston says throughout the trial period, residents have been telling her that there was a distinct, unpleasant smell coming from the plume of discharge.
“There are fears this could be what they’re in for if the unit gets resource consent,” she says. “It is my understanding that the discharge contains contaminants that were not emitted by the previous system.
The level of those were tested as part of this trial, as well as monitoring the visual and odour effects. If the consent details are not notified, how can people be confident it’s safe?”
As well as public notification, Mrs Johnston believes that more air testing should be undertaken in the area, including near Dairy Flat School.
“The discharge is way too near the school and residents for my liking,” she says. “There needs to be more testing, for peace of mind.”
A Waste Management spokesperson says the company has had consent for leachate evaporation technology at Dairy Flat since 1999.
Its existing consent requires that “the discharge must not cause noxious, dangerous, offensive or objectionable odour, dust, particulate, smoke or ash beyond the boundary of the premises where the activity takes place”.
“The original unit has operated for well over 20 years and we are now replacing it with a new plant,” the spokesperson says. “Independent experts have concluded the trial of the new generation unit has demonstrated air quality effects are either similar or less than the effects originally predicted in the air quality assessment for the existing resource consent. They have also assesssed the visual impact of the steam plume as low.”
Dairy Flat School is aware of the proposal, but does not wish to comment.
Waste Management applied for resource consent to operate the new evaporator unit almost a month ago. If granted, the consent would apply until 2028. Auckland Council staff are assessing the application and will decide whether it should be notified to neighbours, publicly notified or not notified at all.