Whanganui District Council chief executive Kym Fell says a contract with Hawkins Infrastructure to build the wastewater plant has been signed.
In a press release yesterday afternoon, Mr Fell said: "I have signed the contract today [Tuesday] following two clear directives from the council in March and again in August this year to proceed with construction of the approved plant design.
"Apart from the council's decisions on the design, this is the first major milestone in our journey to provide an effective wastewater treatment plant that can meet the needs of our domestic and industrial users.
"There are strong views in the community both for and against proceeding with the new plant, including from some of those seeking election. However, the council has thoroughly investigated all options and agreed that the approved design will best serve our community now and into the future.
"It is time to put the shortcomings and mistakes that have cost the community $27 million behind us and move forward with the proven design for our new plant. I have a very clear mandate from the current council to do that."
Mr Fell said the council has a guaranteed maximum price agreement with Hawkins for the construction of the new plant, which will be completed by December 2018 within the budget previously approved by the council.