Ngaaruawaahia Wastewater Treatment Plant Update

Due to significant rainfall over the past week in the Ngaaruawaahia catchment, the wastewater treatment ponds have reached critical levels.

This morning, minor overtopping of the pond was observed. In response, a contractor was immediately engaged to apply additional gravel to the roadway to prevent further overflow. As a small amount of flow entered the adjacent waterway that feeds into the Waikato River, water sampling was conducted today to assess any environmental impact. A follow-up sample will be taken tomorrow.

To manage the situation, operations at the wastewater treatment plant (WWTP) have been adjusted. The treated effluent discharge through the UV system has been set to maximum flow to reduce pond levels and maintain the integrity of the dam walls.

While some progress has been made, further rainfall is expected on Thursday. To prepare, Watercare has brought in a diesel pump to help manage incoming flows and return pond levels to their normal operating range. The pump will discharge partially treated effluent, which will be disinfected using chlorine dosing before release.

We appreciate the community’s understanding and will continue to provide updates as the situation evolves