Heightened risk remains that closed Peel Forest landfill may be exposed

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Rubbish from the closed Peel Forest landfill at the top of the erosion-affected cliff, next to the Rangitata River. Picture taken November 24, 2020.

Bejon Haswell/Stuff

Rubbish from the closed Peel Forest landfill at the top of the erosion-affected cliff, next to the Rangitata River. Picture taken November 24, 2020.

There could be 30,000 tonnes of waste that needs to be removed from the erosion-threatened Peel Forest landfill, according to the latest Timaru District Council estimates.

The landfill is under threat from the nearby Rangitata River, which exposed a section during a flooding event in December 2019, and council has estimated the remediation costs at $11.5m.

The cost was questioned by councillors Allan Booth and Michelle Pye at a recent meeting discussing the draft annual plan as savings were sought with the council then facing a 13% hike in its total rates take.

Cr Booth said “$11.7m is just incredible”.

READ MORE:
* Council dumped with $11.7m bill for clean-up of old Peel Forest landfill
* Erosion-threatened landfill’s risk at Peel Forest still being evaluated
* A fix for one historic landfill identifies problems for others

“Why do we actually have to do something with that. Can we sort of push that out and work on something, some other option that is more cost-effective,” he said.

Cr Pye said “I really struggle, like some of the others in the room, how everything costs so much, like $11m for a digger and few trucks to clear out a dump”.

Staff, in examining the $11.5m figure, stressed the costs were estimates based on the current estimated volumes of material in the landfill.

“As the remedial action plan progresses and greater knowledge of the volumes, and the nature of the material, e.g, presence or otherwise of hazardous substances such as chemicals and asbestos and if so the quantity, becomes more certain the options for remediation and budgeted costs can be presented with greater confidence levels,” a report to a council meeting on Tuesday says.

An aerial view of cliff stabilisation work on the top of the old Peel Forest landfill on Dennistoun Rd.

TIMARU DISTRICT COUNCIL/Supplied

An aerial view of cliff stabilisation work on the top of the old Peel Forest landfill on Dennistoun Rd.

“The landfill volume is estimated to be 20,000 cubic metres (based on ground penetrating radar surveys). This equates to approximately 30,000 tonnes of refuse.”

The report emphasises the “rapid erosion of the Rangitata River banks in the vicinity of the closed Peel Forest landfill has necessitated the need to remove the refuse from the landfill”.

“River bank protection works implemented over the last three years has slowed the erosion process. However, there remains a heightened risk that the landfill may be breached in a future significant river flood event.”

The report says options considered have included further river protection measures, partial removal of the refuse and full removal and site remediation.

Exposed rubbish at the closed Peel Forest landfill site. Photo taken November 2020.

Bejon Haswell/Stuff

Exposed rubbish at the closed Peel Forest landfill site. Photo taken November 2020.

“Discussion on the options has been undertaken with Arowhenua through Aoraki Environmental Consultants Ltd, Environment Canterbury, the Department of Conservation, Land Information New Zealand and the Rangitata River working group.

“The preferred and only long term option, which sufficiently manages the risk of a significant breach, is the full removal of the refuse, and which is supported by council.”

A breakdown of the $11.5m in the report is:

  • Preliminary works including consents, potential wildlife management plan, land owner consents, site management, health and safety planning (this is a hazardous activity), traffic management, refuse composition analysis, leachate minimisation measures $100,000.
  • Estimated excavation and removal costs $4.1m.
  • Refuse disposal costs $5.85m (includes $1.5m waste levy cost).
  • Land remediation $1.7m.

“The impact it will have on the rates in the 2023/24 Annual Plan is not material,” the report states.

“However, long term the amounts are significant and officers believe it is appropriate to present council with its current best estimate of the cost which, while not precise, is, they believe, accurate in respect of the scale of costs.”