environment

Dairy company’s extra river discharge blocked

An application to discharge up to 3560 cubic metres of wastewater a day into a degraded Waitoa River has been declined

Open Country Dairy has been unsuccessful in its bid to discharge wastewater in summer to the already degraded Waitoa River.

The company, which is owned by fishing giant Talley’s, is New Zealand's second largest exporter of whole milk powder. It has been responsible for several breaches of consent conditions for discharges to air and a discharge to the river which cased sewage fungus to grow. Last year it received a record fine from the Waikato Regional Council of $221,250.

The plant’s wastewater has to date been discharged to the Waitoa River in winter when the water flow is above 1.5 cubic metres per second and used to irrigate fields in summer. 

As part of expansion plans, a $17 million wastewater treatment plant is being built to improve the quality of wastewater and the company says summer irrigation is no longer viable. Currently it has access to 350 hectares of farmers’ land and at least 600 hectares is required.

The company sought permission to discharge wastewater to the Waitoa River all year-round, even during summer and regardless of the flow in the river. It requested a term of 35 years, the longest consent term available and suggested riparian planting would mitigate effects..

Evidence submitted at a May hearing on behalf of Open Country Dairy concluded effects of the discharge would be less than minor.

The application was opposed by several groups due to the potential impact on the river, Ramsar wetlands and the Firth of Thames. A planning expert's evidence given on behalf of the Waikato Regional Council recommended the application be denied.

Independent commissioners agreed with points raised by those opposing the application’s summer discharge.

The commissioners said they were not persuaded the wastewater could not be used to irrigate land during summer as has been done to date.

“In our view, however, the beneficial effects of land irrigation, in combination with the greatly improved wastewater treatment, has not been adequately considered by the applicant.”

If a summer discharge to land had been included in the application the commissioners said it would likely have resulted in consents being granted. Instead, in their decision they noted Open Country Dairy had taken a “black and white” approach to discharging to the river or land and sophisticated dual discharge systems are available:

“It may not be as convenient to OCD as discharging totally into the river, but it could avoid the effects in summer/autumn that we consider to be unacceptable.”

The commissioners said there was a large difference in the effects of a summer and winter discharge. They found during summer the effects on the river where the wastewater is discharged would be moderate, not minor.

During summer, the increase in nitrogen and phosphorus would increase aquatic plant growth in the river, which could then deplete oxygen levels. This would negatively affect fish and aquatic fauna. 

They also noted likely effects of climate change mentioned on the Waikato Regional Council’s website: “projected hotspots of future drought exposure in the Waikato region are likely to be in parts of the Hauraki district, followed by the Matamata-Piako and Thames-Coromandel districts.”

Further afield, they agreed cumulative effects should be considered and summer discharge while not causing “imminent ecosystem collapse”, would add to ecosystem stress.  The cumulative effects on the Kopuatai wetland, the Lower Piako river and the Firth of Thames were considered and found to be adverse “and lead to a loss in life-supporting capacity.”

As a mitigation measure, the company had suggested riparian planting on one side of the river. The commissioners said this is mostly used for farms to reduce surface run-off or leaching. It is not a method used when a pipe is pumping wastewater directly into a river. 

Shade provided by the planting could reduce the water temperature and reduce aquatic plant growth, however the applicant was unable to estimate how long it would take the plants to grow for the river to be sufficiently shaded. 

The commissioners noted “nitrogen and phosphorus would simply flow out of the riparian-shaded area, to stimulate aquatic plants downstream” and the suggested planting did not count as mitigation. 

The Waitoa River at the point of discharge during low flow. The red pipe is the discharge pipe. Photo: Evidence submitted on behalf of WRC 

Fish & Game opposed the application. Auckland/Waikato CEO Ben Wilson is happy with the result. 

“We think it was the right decision. On the weight of the evidence, the commissioners didn’t have much choice.”

During the hearing, Wilson said the application flew in the face of local and central government policies.

“We’re extensively involved in point source discharge applications throughout the Waikato region. This is the first time we can remember one going backwards.”

He said the catchment was already highly stressed from nutrient overload and, if approved, the application would have added a new discharge during summer months.

Last summer an avian botulism outbreak and a toxic algal bloom in the Hauraki Plains killed thousands of birds. The dire conditions caused by drought, high water temperatures, silted floodgates and poor water quality also killed eels, a species known for its hardiness. 

He's disappointed other environmental groups weren't more active in their opposition.

"At the end of the day, this is a discharge into the Hauraki Gulf during the summer months, so it has wider implications than just the local area."

Of 10 public submissions, nine opposed the application and one was neutral. Forest & Bird and the Department of Conservation's made submissions in opposition but did not appear at the hearing.

Open Country Dairy did not respond to Newsroom's request for comment on whether it would appeal the decision.

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