Why Treat Wastewater?
Nature eventually cleans water through the water cycle, but this takes time. Treating wastewater accelerates the natural process. Wastewater has a very high number of water-borne bacteria and pathogens. Some of these are completely harmless: others are responsible for life-threatening diseases.
Wastewater is also nutrient-rich. It contains high levels of nitrogen and phosphorus. In the 1980s, wastewater was a major contributor of nutrients which added to Lake Rotorua’s declining water quality problems.
Council’s upgrades of the wastewater treatment plant have substantially reduced the nutrient load to Lake Rotorua. Treatment now involves biological nutrient removal with carbon dosing and land treatment.