Compliance monitoring of a wastewater treatment discharge in the Western Bay of Plenty

At a glance...

The client

Western Bay of Plenty District Council asked for help with monitoring a wastewater treatment plant discharge to meet resource consent conditions.

The challenge

They needed to assess the effects of the discharge on the receiving environment.

The outcome

The consent conditions were successfully fulfilled and we were engaged for subsequent projects.


Western Bay of Plenty District Council needed to assess the effects of a wastewater treatment plant discharge into Te Puke’s Waiari Stream. We were engaged to assess the effects on the stream’s water quality and ecology. Only in finding a solution to protect the environment would the work be allowed to continue.

The ask

Western Bay of Plenty District Council (WBOPDC) needed a specialist freshwater ecologist to monitor the effects of discharging treated wastewater from the Te Puke wastewater treatment plant in accordance with consent conditions and an existing Environmental Monitoring Plan.

Why us?

WBOPDC had been working with a larger firm, but they had been unable to complete the work.

We were brought on thanks to our wide-ranging experience in similar successful projects, strong local reputation, our externally-focused approach, and our accessible, quick-thinking team.

Our solution

Key services included:

Water quality survey:

We used data loggers to continuously measure dissolved oxygen and pH levels upstream and downstream of the discharge and collected water quality samples.

Secondly, we performed transect surveys of macrophytes (aquatic plants) and periphyton (algae). These organisms respond to nutrient changes in the water, so by monitoring these, we were able to track chemical changes. If water nutrients increase, they can expand and shrink invertebrate habitats. So maintaining a balance is crucial to the health of the ecosystem.

Aquatic habitat, flora and fauna survey:

We carried out aquatic flora and fauna surveys in accordance with National Environmental Monitoring protocols.

Monitoring report:

We prepared a concise report analysing and interpreting the survey results, including a comparison with past surveys and current consent limits.


The results

At the time of writing, we have successfully completed two surveys with more monitoring to come in the future.

Thanks to our work with WBOPDC, the treatment plant continues to operate, and the environment is protected for both its natural flora and fauna, and the people that live around it.

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