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 effluent of high environmental quality.

Quick Facts

  • Treated wastewater from Pauanui, Whangamata and Whitianga is amongst the highest quality effluent 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 Consents

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.
  • Discharge of wastes from drinking water treatment facilities and construction of associated structures.
  • Discharges from wastewater treatment plants and associated structures odour discharges.
  • Discharges of urban stormwater and construction of associated structures such as culverts and headwalls.

Some Definitions

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

Bio-solids: Nutrient rich sludge remaining after water is extracted. The basis of great compost after a suitable resting period.

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

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

Rising main: Pressurised pipeline from a wastewater pump station to the wastewater treatment plant.

Sequential Batch Reactor (SBR): Wastewater treatment tanks that aerate untreated wastewater and separate out bio-solids.

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

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

Wastewater: Water and solids that go into our sewage network from toilets, bathrooms, kitchens an