24 May 2017

Water mains cleaning technology a NZ first

The Gore District Council is the first local authority in New Zealand to use specialist technology to clean its water mains and remove trace elements that cause discolouration.

The water mains in Gore and Mataura will be flushed using a mobile filtration unit mounted on a truck. The unit arrived in Gore late last week from Australia and will start work on Thursday (1 June).

District Assets Project Manager Sam Bunting said the NO-DES system creates a temporary loop above ground by connecting to the water mains via two fire hydrants. The water a circulated at a high velocity through the filtration unit until it is clean.

“It will significantly reduce the build-up of trace elements, such as manganese, in our network and improve water quality.”

While Gore was the first council in this country to use this system, it is in use extensively in Australia and the United States, where it was developed.

“The advantage of this system is that is causes minimum disruption for residents, it’s highly mobile and easy to set up, and there is minimal loss of water during the process.”

Mr Bunting said the company would start flushing the water mains near the Hilbre Avenue water tower and move south. The unit will work from 8.30am to 5.30pm Monday to Saturday and cover about six kilometres a day.

The west side of Gore should be finished by Friday 16 June and East Gore completed the following week, before the unit moves to Mataura.

There should be minimal impact on residents, however, some may notice a temporary reduction in water pressure and/or some discolouration, Mr Bunting said.

“If discolouration occurs, please turn on the tap nearest to the ground level, it’s usually an outside tap, and allow it run for up to five minutes until water runs clear.”

Vehicle access to properties will not be affected although there may be minor traffic disruptions. To ensure the safety of motorists and pedestrians, appropriate signage will be in place where necessary.

Mr Bunting said the NO-DES system was a cost effective way to remove the build-up of manganese and iron in the network. In recent years these trace elements have caused problems with water discolouration.

The project is estimated to cost $155,000. International water management company Detection Services is carrying out the work for the Council.

Gore District Council 29 Bowler Avenue Gore P: 03 209 0330 E: