Open Country Dairy will regroup and apply again to discharge wastewater from a new $17 million treatment plant into Waikato's Waitoa River after being turned down by an independent hearings committee.
Chairman Laurie Margrain said the rejection had no impact on operations at the company's Waharoa site near Matamata because it was an application for the long-term, so Open Country would work with Waikato Regional Council towards a re-application.
"We have all the consents we need to operate and at some point we will re-engage with the council with which we have a good relationship and re-submit."
The company's application for a resource consent to discharge contaminants into the air was granted by the hearings committee.
Open Country, New Zealand's second largest dairy exporter, wanted to start a summer time discharge to the Waitoa River when previously wastewater had been irrigated onto land during this season.
The company submitted the quality of the wastewater it proposed to discharge to the river would be significantly improved due to a new $17m treatment plant, the first part of which was already commissioned.
The company said it wanted the consent to enable future expansion of the Waharoa plant and presented evidence that the effects on the river would be less than minor.
But Beca Limited, acting on behalf of the council, argued the cumulative effects during th summer would have more than minor adverse effects on the river near Waharoa and in the Firth of Thames.
The effects in the Waitoa Stream included increased nutrient concentrations in summer, presenting a risk of increased aquatic plant and algal growth which could impact on macro-invertebrates and fish, the committee said in its decision.
It agreed with Fish & Game that there was strong evidence the nutrient discharged under summer low-flow conditions would severely compromise the life-supporting capacity of the lower Piako River and said it was plausible the Kopuatai Wetland, the largest peat bog in New Zealand, would also be affected.
The committee said the Firth of Thames was under significant stress during the summer and autumn, when dissolved oxygen sags below a 70 per cent guideline.
Open Country's application attraction 10 submissions, nine opposed and one neutral.
Meanwhile, Open Country is scheduled at a sentencing hearing on Friday July 24 in the Hamilton District Court after pleading guilty to one charge of unlawfully discharging contaminants into the air at Waharoa. The charge relates to odour affecting the local community and follows a previous conviction for unlawful discharges to land and air in 2018.
Open Country Dairy is 76 per cent owned by New Zealand food company Talleys Group.
Singapore's Olam International owns 15 per cent.
The company has been a global exporter of wholemilk powders since 2004. It has manufacturing sites in the Waikato, Whanganui and Southland and is supplied by around 1000 farmers.