dirty river water selwyn

Flushing out the waste water problem

Alongside the massive problem of 10 million cattle and their waste entering our waterways, is the lesser but vexed issue of human waste. All over the country, councils struggle with developing wastewater systems that actually work and do not pollute the environment. Success is very mixed because disposal of wastewater and solids to land or water is a fundamentally problematic challenge. Our waste was never meant to be dumped into the water. Our waste contains hormones and chemicals as well as pathogens – a potentially toxic cocktail. Treating the waste for all these components is still experimental. We can land people on the moon but we still have not sorted this out.

For tangata whenua, this issue is fraught as their tikanga has always been that human waste belongs in the earth not the water and important cultural values are trampled on by disposal of treated or untreated wastewater to the rivers or the sea. It is also increasingly clear that disposal to land exposes the earth to potentially harmful chemicals and also water quantities that some soil types cannot absorb.

Rotorua is a case in point. The wastewater was being sprayed on to the forests and run-off treated in a wetland system, but the wetland has malfunctioned. Thus the water will be leaching through the soil into waterways and ultimately the lake. A new proposal is to treat the waste to a high level, removing much of the nitrogen and phosphorus and then piping it into the lake. I met with some mana whenua from Hurungaterangi Marae this weekend to discuss their fears about this new proposal. Their marae in the industrial area is near the sewage plant, which is on land gifted to the city by tangata whenua for reserves, not for sewage. Their river Puārenga is still polluted from the Waipa sawmill. So you can understand why they are in no mood to accept a pipe pumping sewage into the Lake. I do not have a magical solution but I do support their questioning of this proposal. The lake edge is a wild place full of hot springs and history, its cultural significance makes it an odd place to build a sewage plant, to put it mildly.

Obviously, a solution for the wastewater needs to be found but given the concerns expressed to me by hapu members and the need to keep cleaning up Lake Rotorua from agricultural run-off and previous pollution, pumping treated waste into the lake will still be an issue! We have to find a way to dispose waste safely to land and spend the money it will need so that we do not pollute land or water.

sign on for swimmable rivers