Solving the complex challenge of wastewater discharge for NZ’s dairy industry with Open Country Dairy

At a glance...

The client

Open Country Dairy are one of NZ’s largest dairy product manufacturers.

The challenge

Open Country Dairy needed to renew their wastewater discharge consent at their Waharoa plant.

The outcome

Through a complex integration of our services and specialist experience, we helped to secure a long term consent.


Open Country Dairy are one of New Zealand’s major dairy producers, with a processing plant in Waharoa, Waikato. They needed ecologists and water quality specialists that were experienced in the dairy industry, and resource consent process, to find a solution.

The ask

Open Country Dairy came to Ecological Solutions for help with a resource consent application. They needed to continue to discharge treated wastewater produced at their Waharoa plant to the Waitoa River.

“The problem for all dairy processes is that they generate a lot of water. Milk is mostly water, and the majority of NZ’s dairy products go out in the form of cheese, butter, or powdered milk. So that extracted water needs to go somewhere – either indirectly via the land or directly to a water source.”

Richard Montgomerie | Managing Director of Ecological Solutions

This is a significant challenge for the dairy industry as a whole. The hydraulic loading (the capacity to absorb extra water) of the receiving environment was severely limited. So, any discharge needed to be managed carefully.

There were a number of moving parts and stakeholders in this project, including Ngati Haua, the Department of Conservation, Fish & Game, and the local community. Open Country Dairy generates significant income for the farmers and community, so securing consent was crucial.

Why us?

“It’s getting harder and harder to deal with direct discharge when securing resource consent. We had worked on a similarly challenging project for OCD before that was a success, as well as numerous other dairy industry projects. So that, combined with our significant experience in the Waikato Region, made us a great fit for the job.”

The varied challenges posed not just by different companies and operations, but by the ecology of regions throughout the country make projects like this unique. They require a combination of ecological expertise, knowledge of the industry and region, and collaboration with multiple stakeholders.

Waikato, like other regions in New Zealand, has its own quirks and unique requirements. We have worked with these for many years. Plus, our founder and Managing Director, Richard Montgomerie, grew up on a dairy farm. So it’s a world he knows well.

Our solution

“We conducted three core services for this project. Firstly, an assessment of effects, where we looked at water quality and the freshwater ecology of the area. We assessed how discharging the facility’s wastewater would impact the surrounding environment.

We presented this expert water quality and ecology evidence as part of the consenting process, where we made recommendations for avoiding, remedying, mitigating, and offsetting the effects. Once we understood the ecological impacts, we made recommendations for a river riparian enhancement plan. This would mean that the environment wasn’t just maintained, but improved.”

This project brought together a number of our core services, including:

  • A water quality assessment: This gave us a measure for the changing state of water quality and aquatic habitats in the receiving environment.
  • An assessment of ecological effects (AEE): This looked at how discharging wastewater impacted the environment, and ways these impacts could be avoided, remedied, mitigated or offset.

“The key thing here was our ability to integrate our expertise of water quality and freshwater ecology, with our local knowledge and our experience in the dairy industry. It was a dynamic merger of our technical, industry, and local expertise that really came together in a great way!”


The results

Discharge consent for Open Country Dairy’s wastewater was secured.

The factory could continue operating, jobs and suppliers were protected, and the river enhancement plan will boost the health of the waterways.

Want to chat about your project?