$17m work diverts sewage from river
Blenheim's new sewage treatment plant is in operation and Marlborough Mayor Alistair Sowman says it is a big step forward.
The $17 million upgrade of the plant stops the discharge of domestic waste into the Opawa River.
The waste from Blenheim and Blenheim's industrial estates west of the town, along with sewage from Renwick, Grovetown and Spring Creek, is now treated in new wetland ponds stretching across 20 hectares next to Hardings Rd.
With new pump stations, pipelines and the treatment ponds, the $17m project is the biggest advance in sewage treatment in Marlborough for more than a decade.
Project manager Bruce Oliver said there was still some work to be completed but the bulk of the project was now finished, and the new ponds were in operation.
From now on, highly treated sewage was being discharged off the coast on the outgoing tide through a buried outfall pipe in the Wairau estuary.
The extended treatment processes meant that only very highly treated wastewater was being sent out to sea.
When weather and soil conditions permit, the treated wastewater would be applied by an irrigation system on to surrounding pasture to reduce the outfall discharge.
The upgrade replaced a system, put in place about 40 years ago, which had allowed treated sewage to be discharged directly into the Opawa River.
Mr Sowman said the completion of this project marked another big step forward in improving the quality of the water flowing through one of the town's main rivers.
"Council advanced this project because we wanted to improve the environmental standard of the Opawa River.
"The new treatment processes will stop the direct discharge and ensure that the wastewater that does go out to sea is in a highly refined state which will be quickly dispersed by the tides," Mr Sowman said.
He acknowledged the involvement of iwi and neighbouring property owners.
"Given the sensitivity of the Wairau Bar site, it is a credit to all concerned that co-operation has been possible to bring this important project together."
The Marlborough Express