Have your say on proposed national wastewater standards for odour and metals

The Water Services Authority – Taumata Arowai (the Authority) has begun consulting on two further national environmental performance wastewater standards addressing odour and metals discharged to water.

Consultation opens today and runs until 5pm on 22 October 2026.

The proposed two standards add to the four wastewater standards passed into law in December 2025. These apply to public wastewater networks which serve just over 4 million people in New Zealand and are primarily owned and operated by local councils.

Over time, national wastewater standards are expected to significantly improve wastewater performance and deliver future cost efficiencies.

Around 60% of council-owned wastewater treatment plants need to be reconsented in the next decade. The standards set clear performance expectations for councils as they plan for, fund and obtain consents for the necessary infrastructure upgrades.

The Authority’s Head of Systems, Strategy and Performance, Dr Sara McFall says discharges to air, particularly odour, and discharges of metals to water are two common consenting challenges for treatment plant operators.

“The proposals would create a clearer and more consistent national baseline, while still recognising that wastewater treatment plants and local conditions differ across the country.

“Communities need to have confidence that there are clear, consistent rules to minimise the impact of wastewater treatment plants on the public and on the environment.”

Under the proposed discharge to air standard, wastewater treatment plants would need to meet minimum requirements relating to odour management, recording complaints, regular site inspections, staff training, equipment maintenance and annual reporting. Higher-risk plants would need more detailed assessment, review and improvement planning.

Dr McFall says odour is experienced differently by people, but it can still be assessed using evidence such as complaints information, site investigations, monitoring, modelling and expert assessment.

“Odour can have a profound impact on people’s use and enjoyment of their homes, marae, schools, parks and other community spaces. A national approach to discharges to air will make expectations much clearer for communities, councils and wastewater operators.”

While odour is the main focus at this stage, the Authority is also seeking feedback on whether other air-borne matters, such as dust from treatment processes, should be included in the proposed discharge to air standard.

The proposed standard for metals in treated wastewater would focus attention and effort to where the risks are greatest. Monitoring or limits would be targeted to situations where the discharge risk and receiving environment risk suggest stronger controls are needed. An example is where higher levels of trade waste inputs are discharged to sensitive environments such as estuaries.

“A range of metals can affect the environment in different ways,” says Dr McFall.

“Their impact depends on the type of metal, how much is present, where it is discharged and whether the metals can build up in sediments or aquatic life. This is why we are proposing an approach that targets the risks rather than a one-size-fits-all set of limits.

“We are also interested in learning more about existing evidence of metals impacting community or commercial interests.”

The proposals have been informed by feedback received in consultation on the first set of wastewater standards as well as input from wastewater operators, regional councils and technical experts, reviews of current consent conditions and technical advice commissioned by the Authority.

Dr McFall says feedback is important to ensure the standards are practical and can be implemented effectively through future resource consents.

“It’s our intention to lift overall performance by setting clearer, more consistent and more transparent expectations.

“We’re keen to hear from water service providers, wastewater operators, regional councils, iwi and hapū, technical experts, community groups and members of the public about what they believe will work in practice and what matters may need further testing.”

Final decisions are expected in mid-2027.

How to have your say

Consultation is open from 10 September 2026 until 5:00pm on 22 October 2026. You can make a submission:

• through the online survey formoutbound (either by filling in the survey questions online or uploading a PDF or Word document with your feedback)
• by post to Level 2, 10 Brandon Street, PO Box 628, Wellington 6140.

We are also holding two information sessions on 18 September 2026 and 28 September. For more information and to register for the webinar, please see the Authority’s website.

Questions about the submission process can be sent to stormwater_wastewater@taumataarowai.govt.nz