A Taranaki composting business at the centre of a consents renewal wrangle is sitting on a 20,000 tonne pile of contaminated waste that could take up to 40 years to safely break down.
A regional council report says it appears Remediation NZ has not done any composting at its Uruti site for about 10 years and has instead been stockpiling waste.
Remediation NZ is part of the Revital Group that produces compost and vermiculture products - many of them Biogro-certified.
It is seeking to renew consents to discharge to land, water and air, which lapsed about two years ago.
It is still permitted to accept various waste at Uruti - including oil and gas drilling cuttings and drilling fluids - to either compost or use in worm farming.
But a damning regional council report says in the past decade only worm fertiliser has left the site.
"Almost all of the other material received onsite for the past 10 years including some unauthorised material (but also authorised organic material that could otherwise be composted) has been deposited into the collection pond, blended with bulking agents, and then stockpiled.
"As a result, the stockpile is now greater than 20,000 tonnes.
The report says even after being composted for 15 years this material does not meet minimum standards.
"This has caused what's referred to in Remediation NZ's application as a 'legacy' issue, as they have been unable to sell this product off-site due to its association with drilling activities.
"It also means that it has not produced any saleable compost from the site in the last 10 years, other than the vermicast."
Sarah Roberts from the environmental lobby group Taranaki Energy Watch was thankful the site stopped accepting oil and gas waste in December.
But she warned the 20,000 tonne stockpile may only be the tip of the iceberg.
"Conservatively 40,000 cubic metres of drilling materials came in, but for four or five years the council said there was very little record taking and so really the whole process of our submission is trying to find out what happened to it and what's going to happen to it?
Sarah Roberts reckoned on closer inspection the Remediation NZ site looked less and less like a composting facility.
"I guess if you really looked at that drilling waste pile - more than 20,000 tonne - I guess you'd start to think this potentially looks more like a landfill than it does a composting facility.
"And if there is no kind of approach to how we might deal with it at the moment it needs to be contained safely."
The waste stockpile leaches chemicals such as chloride and nitrogen and has stormwater runoff and odour emission problems.
Remediation NZ is now proposing to spread smaller lots of 500 tonnes a year as on-site soil conditioner.
Assuming it meets council conditions beforehand, at that rate it will take 40 years to break down.
The company invited RNZ to visit the Uruti site then later withdrew the invitation and declined to be interviewed.
In an email, its sales manager Mark O'Neill said the company and its staff were environmentalists.
"We are remediating waste that does not just disappear because a group of so-called eco-warriors decide that it should. This waste needs to be dealt with in order to make it safe for the environment.
"We have a consent which is strictly adhered to - the water is tested on an almost daily basis and the ridiculous discharge to air consent is exploited by a bunch of locals who want our operation shut down."
Remediation NZ has a history of non-compliance with consents and was the subject of eight incident reports, three abatement and six infringement notices between October 2020 and January 31 this year.
More than 20 public submissions have been received on the consents renewal, 13 for and 10 against.
Supporters include the New Plymouth District Council and companies such as Fonterra, Tegel, Wastemanagement and Environwaste, which argue Remediation NZ provides a sustainable option for waste disposal not available anywhere else in Taranaki.
The council report recommends renewing consents for seven years under a slew of conditions.
The consents renewal hearing begins next Wednesday.