The council has completed its application to continue using the Green Island landfill until it builds a new dump south of Brighton and then closes the city’s current landfill.
The council’s consent to operate the Green Island landfill expired in October last year, but the Resource Management Act allows for consent holders to continue to exercise existing consents while applying for replacement ones.
The council applied to extend the consents for the city’s landfill until 2029 or 2030 in May last year, but the Otago Regional Council asked for more information, including a gull management plan and an assessment of the health risk the landfill presented.
Last week, the additional information was provided.
Now, a decision on notification by the regional council is due by the end of this month.
"Continued waste disposal at [Green Island landfill] will be more cost-effective than out-of-district disposal, and result in lower emissions, road network wear and tear and congestion," the city council’s application said.
"It will provide flexibility to fluctuating waste demands and ensure there is a viable option for the continued disposal of waste until which time operations at Smooth Hill commence, including allowing for delays and for a period of transition in operations at the two landfills."
An economic assessment said hauling waste to Winton’s AB Lime site, a 388km round trip, was expected to cost $150 per tonne of waste and would need to drop to $100 a tonne to be competitive with a landfill at Smooth Hill.
Further comparison was not available due to commercial sensitivity, but the Green Island site was "unequivocally" favourable in terms of cost compared with Smooth Hill due to lower capital costs and proximity to the city’s population.
"By extension then, because the Green Island site is more cost-effective than the Smooth Hill site, it is likely to be at least 33% more cost-effective than the out-of-district option."
The application said improvements in the leachate collection system would ensure the effects on groundwater and surface water would remain low.
Implementation of a gull management plan would ensure the probability of an increased bird-strike risk arising when the landfill stopped accepting organic waste would be low.
Earthquake and sea level rise resilience improvements would be made.
And the continued operation of the landfill within its existing footprint would result in no change to the surrounding habitats or animal life in the ecologically significant Kaikorai Steam and estuary, the application said.
The council would ask the community to establish a community liaison group to ensure ongoing engagement between the council and the community on the operation and closure of the landfill.
Issues raised by neighbours during meetings before the application was lodged revealed ongoing concerns about pest and gull management.
Neighbours also spoke about plantings that screened the landfill, but preserved views.
During earlier pop-up sessions, the council had spoken to more than 400 people.
"They liked the idea that the area around Green Island site could provide recreation opportunities in the future, such as tracks and trails, when the landfill closed," the application said.
There was some concern for the health of the Kaikorai Stream and estuary and council staff were asked whether there were plans to improve the health of the waterway.
There were concerns raised about the illegal dumping of waste.
People were also keen to get updates on the plans for the proposed landfill at Smooth Hill, the application said.
