Kāeo Wastewater Treatment Plant
Plant overview
The Kāeo wastewater treatment plant is located off Dip Road in Kāeo. The plant serves about 250 properties in Kāeo, including the Whangaroa Health complex (the old hospital), Whangaroa College and Kāeo Primary School. About 15 properties in Whangaroa are also served by the Kāeo plant. This wastewater is collected in a holding tank which is transferred to the plant by truck once or twice a week. The plant treats approximately 140 cubic metres of wastewater a day.
Treating the wastewater
Solids are removed from the wastewater before entering the large oxidation pond. In the oxidation pond a combination of sunlight, algae and microbes perform biological processes which clean the wastewater. Sunlight and time naturally kill off harmful bacteria, while the algae and microbes consume the organic matter in the wastewater. Wastewater will stay in the oxidation pond for at least 40 days.
The treated wastewater is then dispersed over a filter made of rocks. The rock filter, initially designed to incorporate worms, provides further treatment by filtering any solids and reducing nitrogen.
In the final stage of the treatment process the treated wastewater is disinfected by passing through an ultra-violet light (UV light) unit. UV light mimics the natural process that sunlight provides by destroying the DNA of bacteria and viruses so that they cannot replicate in the receiving environment. The treated wastewater is then discharged to the Kāeo river.
Monitoring
The discharges from the treatment plant are authorised by a resource consent. Consent conditions require regular monitoring of the wastewater quality at four locations along the treatment process. Consent conditions also limit the volume and quality of the treated wastewater discharged to the Kāeo River. You can see a copy of the resource consent document here.
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Location
Dip Road, Kaeo 0479 View Map