Wetlands take shape as sewer project progresses
Wetlands take shape as sewer project progresses despite weather
Extensive earthworks covering 10 hectares of land to the south-west of the Timaru District Council’s wastewater treatment plant upgrade on Aorangi Road have dramatically transformed the landscape of the area as the project’s wetlands take shape.
The major earthworks add to work carried out over the last year on the north side of Aorangi Road where 30 hectares of land are being sculpted into primary oxidation ponds, and eight hectares into maturation ponds.
The $17 million project represents a major advance in the way the district processes, treats and discharges its wastewater. It is the culmination of years of council planning via its Timaru District Wastewater Management Strategy. The project follows a five-stage upgrade over the last few years of the main trunk sewer between the Timaru urban area and Aorangi Road designed to provide the separate waste streams needed for the enhancement of the district’s sewerage infrastructure.
Work being undertaken by principal contractor Downer, sub-contractor Rooney Earthmoving, and design consultants CH2M Beca for the Timaru District Council, will see the district meeting new effluent quality standards before discharge to the sea. The consent is for the next 35 years.
But the weather is not helping as the council endeavours to meet deadlines. The project was originally estimated to have been completed by this December.
Council drainage and water manager Grant Hall said today a particularly inclement winter and spring with snowstorms and rain had put back work considerably.
“The nature of this project is about ground conditions. Excavators and heavy machinery can only work when the conditions are right and we have had some delays. Groundwater conditions are also key. A high water table means difficulties when you are excavating,” Mr Hall said.
“In some areas there is quite a narrow window of opportunity available for carrying out earthworks between when the rain stops and when groundwater levels come up because of irrigation.”
Mr Hall said components of the project that do not involve excavation, such as construction of structures and installation of pumping and associated infrastructure such as mechanical and electrical equipment, are all on track to be completed by the end of this year.