Wanganui ratepayers will know later tomorrow what option the district council has picked for a multimillion-dollar upgrade of its wastewater treatment plant. But the cheapest of these options still comes with a price tag of at least $38 million.
The front-runners all incorporate a drying plant in the treatment process, with dried sludge either sent to landfill or spread on land. Capital costs range from $38 million to $40 million.
The council has been faced with a costly upgrade to the Airport Road plant, which has been fraught with problems since it was commissioned in 2007. Those problems came to a head in the summer of 2012-13 when odour from the plant spread over the city.
Tomorrow's meeting will consider a number of possibilities but all include the use of a drying plant to minimise the sludge produced at the plant. It is the sludge and its removal which poses the greatest cost.
Engineers say a drying plant will means sludge can be either trucked to landfill stations near Bonny Glen (Marton) or Hampton Downs (Waikato), or spread on nearby land. This last option is expected to gain the strongest support around the council table.