Investigators will comb through up to 200 tonnes of rubbish a day at Brisbane landfill sites in the search for the body of retired teacher Lesley Trotter.
The Australian Defence Force has joined a team of police investigators to sift through an enormous search area for any trace of Ms Trotter, 78, after she vanished from the inner suburb of Toowong on March 28.
Ms Trotter's mobile phone and wallet were found in her unit and her car was still in the garage.
Days of searching became weeks and the hope of finding her alive faded as police confirmed they feared Ms Trotter was dead and were treating her death as a homicide.
Investigators believe Ms Trotter was killed the night she went missing, her remains hidden in a wheelie bin for rubbish collection, before being compacted and freighted to two massive landfill sites.
Detective Superintendent Andrew Massingham said the search had started at the Swanbank landfill facility on the outskirts of Ipswich.
"I can confirm that our search for Lesley Trotter has commenced here at Swanbank. It has taken two days of site preparation to get us to this point," he said on Tuesday.
It was a challenging task for engineers to narrow the search site long before the search could begin.
"The area that we do have to search is quite enormous," Det Supt Massingham said.
"There is some 3000 tonnes of general waste that we need to sort through."
It will be a slow and difficult process, with much of the work to be conducted by hand.
The waste will be exhumed from the landfill and tipped into 30cm deep trenches, which will then be pored over by investigators.
Det Supt Massingham said teams would be able to comb through about 200 tonnes of rubbish a day, weather permitting, and the search would take about two to three weeks.
"This is very much a hand-and-eye type search, using rakes and indiscriminate-type equipment to sort through the general waste," he said.
Searchers clad in personal protective equipment will need to be decontaminated at the end of each shift and air quality will be monitored during the search.
"We expect a number of lengthy days ahead of us," Det Supt Massingham said.
"We have sufficient resources to ensure we have the best opportunity of finding Ms Trotter's body.
"You can understand the nature of this task is extensive and not particularly pleasant."
Recovering Ms Trotter's remains could be vital to the investigation, as police gather evidence and her grief-stricken family continue to cling to the hope that she will be found and eventually laid to rest.
