The operators of Bonny Glen landfill will find out later this month if it has done enough to continue using the Marton wastewater treatment plan to process its leachate.
Leachate is runoff from the landfill and toxins the water has collected has been partly responsible for the treatment plant's compliance failure in recent years.
The Rangitikei District Council will decide on June 30 if it will allow Midwest Disposals to continue using the plant.
The company's general manager Paul Mullinger spoke to the council's assets and infrastructure committee meeting this week.
Midwest has recently installed a pre-treatment facility at the landfill which had resulted in a 18 per cent reduction in oxygen demand and at least an 11 per cent reduction in ammonia.
However a council report said it was not enough for the plant to be able to consistently meet compliance, as leachate from the landfill makes up half of all ammonia going into the wastewater treatment plant.
Last year the Rangitikei District Council gave Midwest Disposals until next June to ensure the levels of the leachate were up to an acceptable standard.
Council chief executive Ross McNeil said the wastewater treatment plan had been compliant in recent months.
He said the council would be speaking with Horizons Regional Council to discuss whether it was happy with the progress made by Midwest.
The views of Horizons would help inform councillors' decision later this month.