A proposal to truck Taranaki's waste up to 300km away is being considered by the region's councils, despite $7m already being spent on developing a $42 million local landfill.
Taranaki councils are looking at a proposal to truck the refuse to the Bonny Glen mega-dump near Marton.
Approximately $7 million has already been spent towards developing a regional landfill at Eltham, south of New Plymouth.
Midwest Disposals, the operator of the Bonny Glen mega-dump, has long coveted Taranaki's waste and has made an offer to the region's councils that could see millions of dollars saved.
South Taranaki mayor Ross Dunlop said the proposal was being taken seriously.
"Obviously we would like to have our landfill here in Taranaki, but we also need to look at the economics and if there is an offer on the table we really need to evaluate it seriously," he said.
Mr Dunlop said the money spent so far on the Eltham landfill, which had been consented to take 2.2 million cubic metres of waste over its life, would not be lost.
"We would certainly want to know that if we go to the alternative that $7 million hasn't been wasted.
"The only reason we have got this good offer is because we have the consented landfill. So whilst it might seem we've spent a lot of money. We may have spent a lot of money to save a lot of money as well."
Midwest Disposals is in a joint venture with Envirowaste and Wastemanagement - both major waste transport businesses.
Mr Dunlop said the councils would make sure any deal stacked up before going ahead and that the proposal's carbon footprint would also be considered.
In a joint statement, the chief executives of Taranaki's three district councils said the Midwest offer had forced them to reconsider their waste disposal options.
"The preliminary proposal suggests there could be savings of millions of dollars for Taranaki ratepayers and a detailed investigation into this option is underway. If the option to use Bonny Glen were adopted by the three councils, the Central Landfill could be banked for future use."
But Manawatu environmental consultant Greg Carlyon said the councils should be wary of putting all of their eggs in the Bonny Glen basket.
"It's going to be the monster for the lower North Island there's no doubt about that. All of Kapiti, Horowhenua and I imagine eventually Wellington and possibly Wairarapa will end up there as well.
"What I understand is that other councils are nervous about being put in a position where this company has them by the short and curlies."
Mr Carlyon said the proposal might not look so good in a few years time.
"Once you're in and you've got a decent deal the alternative of building your own landfill becomes by the day less attractive, but then once you've got a monopoly in place it can potentially run the other way.
"So I'd imagine that's what a number of the district councils are thinking about."
Envirowaste -- speaking on behalf of the joint venture - declined to comment.
Any decision on the Bonny Glen dump proposal to Taranaki could be as much as a year away.