Whanganui District Council is set to take back the keys to the city's new wastewater treatment plant and is planning to open it up to the public.
It will be a chance for ratepayers to see behind the scenes at the almost $40 million plant within a few months of the plant being fully operational.
The open day is planned for March 18 at the Airport Rd site.
Construction on the site began about 15 months ago.
"Anybody and everybody can come and have a look and find out about it," council infrastructure general manager Mark Hughes said.
As of January, the plant was 94 per cent complete and the council will take over the plant from the contractors at the end of March to begin commissioning.
Mr Hughes said the project was so far on time and on budget with only four per cent of a contingency budget used.
"Everything's going really well at the moment."