The Grey District Council will need to spend at least $60,000 to make its case against the latest resource consent application by the Taylorville Resource Park.
Mayor Tania Gibson says the council will not give up the fight against what it sees as a future threat to its $20-million water supply from the private landfill.
TRP Ltd has applied to the Regional Council for consent to discharge contaminated water - a mix of stormwater and landfill leachate - from a retention pond to land, and groundwater outside the dump site.
The discharge site sits above a water supply intake, which supplies drinking water to Greymouth.
The application is being processed on a limited notification basis, and only the GDC, Te Runanga o NgatiWaewae and two neighbours of the landfill are considered affected parties with the right to formally oppose or support it.
One of those neighbours is WCRC chair, Peter Haddock.
"Tonkin and Taylor have given us an estimate for the work the council will have to do for our submission, and we'll need to present at the hearing , then our lawyers are involved, that's why we've said $60,000 and it could be more."
That was a cost to the community that ratepayers could ill-afford, Gibson said.
"No-one's coming to save us but ourselves. But it's just diabolical to have to fight this when we don't want them discharging to water and land above our water treatment plant. "
The mayor met with Taylorville residents on Tuesday, to tell them what the council was planning to do, she said.
"They are pretty devastated and upset. But we have to fight this with facts, not emotion. We are going to go in with as much specific technical information as we can and we will need to engage someone with that knowledge. "
The GDC's independent water testing had shown contaminant levels rising in the road drains and groundwater near the dump, Gibson said.
TRP Ltd is about to apply for a more comprehensive resource consent, for a Class 2 landfill, which would allow it to expand and take a wider range of waste materials as of right and has asked for that application to be publicly notified.
It had applied for the current consent as an interim measure last September but the council was only now getting around to processing it, a company spokesperson said.
For residents living near the dump, the prospect of fighting the major Class 2 consent is daunting.
Adrian and Christine Van Dorp, who can see the operation from a bank on their lifestyle block, are considered affected parties.
"We've been sent three hundred pages of stuff to wade through to make a submission and I can't see how we're going to stop this, but we can at least try to stop them expanding."
The application states that any effects on groundwater will be less than minor and it would be impossible for contaminants to find their way into the Grey River.
But the Van Dorps say it's beyond belief that the dump was ever consented in the first place.

When former Regional Council Andrew Robb subdivided his adjoining farmland five years ago, neighbours were given no warning that the land would become a landfill, Adrian Van Dorp said.
The current Regional Council chair, Peter Haddock also owns undeveloped land next to the landfill and is considered an affected party.
"We're all interested to see what he submits," Adrian Van Dorp said.
"There are 28 of us living around here and the damn thing is a blight on the neighbourhood. It's affected property values and it literally stinks.
"When the winds blowing one way we get it - and the smell makes you feel sick. When it blows the other way our neighbours across the terrace get it. "
Haddock was asked for his views and told LDR the submission period on the short-term consent had been extended and he was considering the available information.
The company in its application submits that any discharges would have less than minor effects on waterways.
LDR is local body journalism co-funded by RNZ and NZ On Air.