Raglan wastewater discharge consent

In consultation with the community a ‘long list’ of treatment and discharge options has been narrowed to a ‘short list’. Planning, environmental and engineering experts are assessing these to find a single preferred treatment and discharge solution (also known as the ‘Best Practical Option’ or BPO). Considerations include:

• Land suitability for irrigation
• Marine modelling
• Public health and wellbeing of the community
• Ecology of fresh water and marine environment

During the investigation phase of our ‘short list’ options, we have conducted monthly e-meetings and communicated with key stakeholders, community representatives, hapuu and other interested parties. These monthly meetings have also provided a forum for wider discussion. This has provided the project team with an appreciation of ‘the Raglan way’, including emphasis on re-use and innovation approaches. An example of this is seeing wastewater as a potential resource, rather than a waste to ‘be rid of’.

Once the preferred treatment and discharge option has been determined, a long-term resource consent application will be made to the Waikato Regional Council (WRC).

Local iwi, the wider Raglan community and other stakeholders have expressed a strong preference for a discharge to land option, which we have been investigating for several years.  

Since 2019, with help from Watercare which is contracted to deliver the Councils waters services, we have widened our investigations to include other alternatives. For example, we’re currently assessing the potential for schemes that combine the reuse of reclaimed water for summer irrigation with an alternative discharge during winter. More advanced treatment plant types have also been assessed that could replace existing oxidation ponds.

Given the complex technical engineering, environmental and cultural considerations involved in the option assessment process, these investigations have taken considerable time. As part of these investigations, we must assess the costs and affordability alongside cultural and environmental considerations.

The table below represents a short list of the options still under review. The discharge consent application will include a ‘preferred option’ from this list. As required by the Resource Management Act (RMA), the application will also need to outline why other options were discounted.

¹ Tertiary membrane: Is a fine filter that removes solids and bugs;

² Membrane Bioreactor (MBR): Is an advanced treatment process that removes nutrients, solids and bugs;

³ Existing treatment process: Oxidation ponds with aquamats that promote biological treatment of wastewater followed by U.V disinfection;

⁴ Winter flow:  This period is when soils are saturated to a point where land irrigation is not possible, and increased flows to the WWTP occur (typically during rainfall events)

In day-to-day management, fully treated wastewater is released on an outgoing tide into Raglan Harbour.  

In November 2022, Raglan's water governance decision-makers have approved a state-of-the-art upgrade to the treatment plant, and construction planning is underway. The upgrade offers the best cost/benefit solution for Raglan and could lead to future reuse opportunities. There are two land discharge options: public land discharge (Option L1) and private land discharge at a rural site with suitable soils for sub-surface land irrigation (Option L3).

Studies on public land discharge have been paused to explore private land discharge. The next steps are securing the necessary land discharge areas and conveyance route at a key investigation site. This would then enable public engagement on an alternative to the present tidal point source discharge to Whaingaroa Harbour. Land discharge documents with sub-surface land irrigation methodology and successful schemes in New Zealand are available.

Earlier update  June 2021

As a result of investigations (including assessing the cost of each option, hapuu feedback and engagement with community reps, alongside environmental investigations) Option L1 (public land discharge) is being investigated further. The further investigation will look at specific sites and the ability of these to accept wastewater at different times of the year.

Let the project team know you would like to be kept updated by emailing Stephen Howard (Watercare Planner), and we will add you to our email updates. You are also welcome to take part in our monthly online e-meetings when we update the community on progress and answer any questions.

Due to the nature of the resource consent application, the Council believes it will be publicly notified by the WRC. Anyone can make a submission for the WRC to consider when it processes the application.  You can indicate in your submission if you would like to speak during the hearings phase. 

Information about our wastewater treatment plant can be found in the Wastewater section of our website

Please read the Dept of Conservation information sheet that covers Toxoplasmosis risk to the Hector and Maui Dolphin. A key educational message is to “Please bury any kitty litter droppings in the garden, rather than flushing them”