Wastewater Treatment

We have built three wastewater plants to service Tairua-Pauanui, Whangamata and Whitianga. Known as Sequential Batch Reactor (SBR) plants.

Read on to see how the system works, how wastewater is treated, the eco-friendly way that we’re disposing of it, and other advantages of this new system.

Through the SBR process, the most basic of human functions – that which is flushed away – becomes a source of goodness in which plants flourish. These highly sophisticated treatment processes have the capacity to produce water of drinking quality.


Quick Facts

  • Treated wastewater from Pauanui, Whangamata and Whitianga is amongst the highest quality produced in New Zealand.
  • Wastewater processed daily: wet weather peak flow at 7500 m3/day in Pauanui with future capacity for 11,100 m3/day. In Whangamata peak dry weather flow is 6000 m3/day and wet weather flow peak 7,800 m3/day. Whitianga 7700 m3/day dry peak flow, wet weather flow peak 12,700 m3/day.
  • Length of time to construct: Pauanui 14 months/Whangamata 12 months/Whitianga 18 months.
  • Construction costs (actual): Pauanui – $25 million, including treatment plant, pumps, rising main and irrigation. Whitianga - $18 million, Whangamata - $38 million (treatment plant $26 million and irrigation $11 million and resource consent $1 million).

RMA Consent Renewal

Council is required, by the Resource Management Act, to obtain consents for many of its water related activities.

Consents are required for

  • Abstraction of water for drinking water supplies and associated structures such as dams and intakes
  • Discharges from wastewater treatment plants and associated structures odour discharges
  • Discharges of urban stormwater and associated structures such as culverts and headwalls

As of November 2018, we are in the process of renewing consents for:

Abstraction from the Omahu Stream

The Omahu water take is part of the Thames Valley Scheme and is the Council water source for the Omahu, Wharepoa and Hikutaia areas.

The current consent expires in March 2019 and the renewal application has been submitted to continue abstraction at the current levels but with the intent for a significant reduction as pipes are replaced and leakage identified.

Discharge from the Thames Wastewater Treatment Plant

The Thames WWTP has been servicing the Thames community for many years. The plant functions well and meets the needs of the community.

The plant has been, and remains, fully compliant with conditions of the existing consent.

The current consent expires in June 2019. Council has been, and remains, fully compliant with the current consent.

It is intended to seek to renew the consent with similar requirements although it is expected that some improvements in the discharge quality will be mandated.

Discharge from the Matarangi Wastewater Treatment Plant

The current consent expires in December 2020 A working group has been established since June 2016 and 15 effluent discharge options have been considered.

The application for the new consent will be lodged mid-2019.

Discharge from the Cooks Beach Wastewater Plant

The current consent expires on 30 June 2019. Council has been, and remains, fully compliant with the current consent.

Application for consent replacement will be lodged before 31 March 2019.

Additional groundwater monitoring has been implemented, and further surface water monitoring is intended during the summer this year, to provide additional data to support the application and facilitate on going monitoring.


Some Definitions

Wastewater: Water and solids that go into our sewage network from  bathrooms, kitchens and laundries.

Rising main: Pressurised pipeline a wastewater pumpstation to the plant.

Resource consent: Consent that must be obtained from environmental agencies (in this case the Waikato Regional Council) stating what must be done to protect the environment from adverse effects.

Grit Treatment: Separation of elements that enter the headworks and won’t break down during treatment.

Sequential Batch Reactor: Tanks that speedily aerate wastewater and separate out bio-solids.

Bio-solids: Nutrient rich sludge left behind when  water is extracted. The basis of great compost.

UV treatment: Ultra-violet light that disinfects the treated effluent and kills micro-organisms.

Sub-surface irrigation: Underground pipes for dispersing highly treated wastewater.

Beneficial re-use: Recycling of highly treated wastewater for irrigation and biosolids into compost.

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