The Rotorua Wastewater Treatment Plant has a connected population of approximately 53,000 people. We treat an average of 18,000 m3 or 18,000,000 litres of wastewater per day. The majority being domestic household wastewater with a very small percentage being industrial waste. Stormwater or rain water is not part of our sewerage treatment system. We treat wastewater for a variety of reasons.
Wastewater has extremely large numbers of water borne bacteria and pathogens.
May of these are responsible for life threatening diseases while others are completely harmless. Wastewater is also nutrient rich. It contains high levels of phosphorous and nitrogen. The nitrogen mainly in the form of ammonia. We must also lower the levels of these nutrients in our final effluent.