The final pieces of pipe in the North West Ashburton wastewater extension were laid underground on Allens Road recently, but not before attracting a bit of attention because of their unusual shape.

The final 64 metre section of pipes is larger in diameter than all the other pipes in the 2km of new network and designed to act as a storage chamber for wastewater coming from the north-west. The fibreglass chambers were laid in a trench dug in the middle of Allens Road between Mill Creek and Carters Road, next to a pump station that will pump the wastewater to Middle Road and the town’s main wastewater network.

The north west extension is to cater for future residential subdivision in the area.

Infrastructure and Open Spaces Group Manager Neil McCann said the additional storage volume is required to accommodate sudden surges, which often happen on rainy days.

“A surge is often the result of more people being inside on rainy days or when water in the ground gets into the wastewater system. Based on future developments in the Farm Road, Carters Road, Allens Road area, the extension required 287 cubic metres of storage, and this storage pipe helps us achieve that.

“The tank has a lifespan of approximately 40 years, so it will be in the ground a long time.”

The $3.285 million project began last September and has gone smoothly to date, with contractors Tru-Line Civil undertaking the work.

“We appreciate the work has resulted in disruption to traffic with some roads closures at times, so we really want to thank residents for their patience,” Mr McCann said.

““At the end of the day, this is important infrastructure for the future and the new sewer system will cater for new homes and subdivisions in the area. People will be able flush their toilets and send the wastewater directly to the sewer mains, and existing homeowners with septic tanks will also have the opportunity to hook up to the wastewater network.”

The project is expected to be completed by the end of May.