Cromwell WWTP Upgrade complete


​​​28 November 2018

Today the Central Otago District Council celebrates the completion of the Cromwell Wastewater Treatment Plant (WWTP) Upgrade Project, which came in under budget and ahead of schedule. The upgrade included connecting the Bannockburn Wastewater System to Cromwell. The upgrade is the first phase of the Council's 10-year Plan to improve the quality of the district's urban wastewater discharges.  

The Council Infrastructure Team credits innovative design and construction methods by local contractors Fulton Hogan and Downers for the early and efficient completion of the project.

The project commenced in January 2016 and was estimated to cost $10.9 million. The final investment was $8 million, saving ratepayers $2.9 million dollars, which will be reinvested into future projects within the plan.

"Safe, clean water is a precious resource we all value, and the Council is determined to protect it for future generations," said Deputy Mayor and Cromwell Community Board Chair Neil Gillespie.

"We invested ratepayer's money effectively and at the right time, with the latest technology and design."

Some of the new technology at the wastewater treatment plant includes Kiwi-designed Aquarators, which mix air into the ponds to allow bacteria and algae to break down harmful matter and clean the water (pictured right). The water is then pumped into the newly upgraded membrane plant (pictured above) and through a large new filtration system, which is made up of millions of hollow straws that further filter and clean the water.  The filtering process is chemical free.  After this process, the treated water is discharged into Lake Dunstan and is clean enough to swim in. ​

The upgraded plant now has the capacity to deal with three times the volume allowing it to cope with the demands of Central Otago's growing population base now and in the future.

"Thanks to the upgrade E. coli levels are 1,000 times better and we're ready to handle the demands of our growing population efficiently and sustainably," Mr Gillespie said.

The Central Otago District Council successfully manages seven public wastewater schemes in the region and continues to invest in these with regular upgrades and maintenance to avoid long-term problems.

"The quality of our water is important, not just for today, but for future generations so that we can all continue to enjoy the things we love about our region such as swimming, boating and fishing,"

Page reviewed: 28 Nov 2018 11:00am