Plan to address Wastewater Treatment Plant odour

An odour mitigation plan for the Wastewater Treatment Plant has been released by Christchurch City Council.

The plan was produced in response to issues raised in a Compliance Monitoring Report from Environment Canterbury, following reports of odour in areas close to the plant.

Read the plan here.

Head of Three Waters Brent Smith says the plan outlines the many actions the Council is taking to address the issues, improve the performance of the plant and lessen the impact on the community.

“We’ve had a hot and dry summer which means the sewage entering the plant is more concentrated and anaerobic . When you combine this with hotter temperatures you end up with an increase in odour.”

“An intensive monitoring programme has helped us identify a range of sources at the plant, and we have work underway or planned to address these.”

“One of the main sources of odour is the primary settlement tanks, which haven’t performed well over the summer period. We’ve decreased the amount of time sewage is held in the tanks and early indications show this has reduced odour.”

“The recent increase in smell is a significant cause of stress for the community and we’re committed to doing everything we can to minimise this.”

“Keeping the plant running in its damaged state is challenging and there will always be an element of unpredictability, but our team is experienced and quick to respond to whatever is thrown at them.”

“As we move into winter, the biology of the ponds will change, which is likely to result in a couple of weeks of increased odour. We can’t predict exactly when this will happen, but we’ve got a plan ready to go to minimise odour through this period,” says Mr Smith.