Detectives have been treating the disappearance of the 78-year-old as as a possible homicide.
Investigators said last week they believed she was dead after conducting extensive searches at Brisbane's Mt Coot-tha, based on the fact Mrs Trotter was an avid hiker and bushwalker.
She last spoke to her family on March 27 and wasn't at her Toowong home when they visited the following day.
Her mobile phone and wallet were found in the unit and her car was still in the garage.
Detective Superintendent Andrew Massingham said police believed Mrs Trotter's body was in a wheelie bin on Merivale St at Toowong on Tuesday, March 28 before rubbish trucks delivered its contents to a Nudgee transfer station.
He said due to the positioning of her body, detectives couldn't rule out foul play and continued to treat the matter as suspicious.
"That rubbish truck went to the Nudgee transfer station where the rubbish was dropped into a pit," Supt Massingham told reporters.
An additional 22 trucks visited the site that day. Their loads were compressed before being taken to six dump sites across Rochedale and Swanbank.
"The location of that rubbish at each of those sites has now been quarantined. In fact, it was quarantined over the weekend," Supt Massingham said.
"We are currently planning an extensive search of both those sites to recover the remains of the person we believe to be Lesley Trotter."
Supt Massingham said the search would be complex and difficult, with excavation needed at Rochedale.
Once engineers finalise the scale of area to comb, police will commence a "piece-by-piece" operation.
"I thank those members of the public ... we have so far interviewed," he added.
"Our doorknocks in the area are coming towards the end.
"It was important the information relevant to the location of her body was kept quiet across the weekend until we were able to exhaust people's memory with respect to their recollections on Tuesday the 28th of March."
