The search for missing Christchurch man Michael McGrath will continue at the Kate Valley landfill site in Waipara on Thursday.
The site is where a majority of the city's rubbish is taken, and police will begin the search accompanied by 20 members of the New Zealand Army.
Police say they continue to hold grave concerns for Mr McGrath's safety.
"We are very grateful for the assistance we are receiving from the NZ Army," Detective Inspector Darryl Sweeney says.
"Searching the landfill will obviously be a challenging task, and we are fortunate to have the personnel and logistical expertise of the NZ Army available to us."
A number of locations on land and water have been investigated following Mr McGrath's disappearance.
The landfill search is expected to take at least two weeks.