Wastewater in the Waikato

Waikato Regional Council Senior Scientist Water Quality Dr Eloise Ryan describes some of the types of wastewater that are produced in the Waikato region.

Question for discussion

• How do you think geothermal wastewater is treated to remove heavy metals and to cool the water?

Transcript

DR ELOISE RYAN

There are many different types of wastewater, especially in the Waikato region. For example, we have geothermal wastewater from our geothermal power stations, and that wastewater is hot and full of heavy metals. So if you put that into a river, it impacts it. The other main source of wastewater in this region is sewage or effluent. That is treated, but it has an impact as well by increasing nutrients, sediment and bacteria in our waterways.

So a lot of our wastewater or sewage discharge companies have permits called resource consents that require them to treat the water, and every year, the technology gets better and better at treating our wastewater. For example, a lot of the wastewater treatment plants now discharge zero bacteria, and technology is improving to remove nutrients such as nitrogen and phosphorus.

Acknowledgements

Dr Eloise Ryan
Waikato Regional Council
Footage of Ngatamariki Power Station, Chris Sisarich