Updated

Investigators probing the disappearance of a Phoenix mom -- who's been missing since May and is feared dead -- are set to start a "very tedious" search next week of an Arizona landfill that may be the woman's final resting place.

Phoenix Police said the search of the Buckeye landfill for Christine Mustafa will begin Monday.

"We have various law enforcement agencies that have donated resources and supplies," Phoenix Police spokesperson Alan Pfohl told FOX10. "Coordinating that takes some time. This is going to be a very tedious search."

Mustafa Search

Christina Mustafa has been missing since May. (Phoenix Police Department)

Pfohl said officials "really think" Mustafa's body will be in the landfill, and will send 30 officers from various agencies across the state to participate in the search.

Police began focusing on the landfill about a month into their investigation of Mustafa's disappearance, but officials wanted to wait until summer has passed to comb through the facility.

"The searchers are going to be required to be dressed out in protective gear which does not breath very well, so we wanted to get through the summer months because doing a search like this in the summertime can be very dangerous for our searchers," Pfohl said.

Arizona Landfill

FOX 10 Phoenix (Police will start Monday to search the Buckeye landfill for Christine Mustafa's body.)

Mustafa was last seen leaving work at a Walgreens pharmacy on May 10, Phoenix police said. She didn't show up to work the next day.

Mustafa's live-in boyfriend, Robert Interval, was arrested in early June on first-degree murder charges after a search of their home, though a body was never found, FOX10 reported.

Mustafa Boyfriend

Mustafa's life-in boyfriend, Robert John Interval Jr., was arrested in June on first-degree murder charges. (Maricopa County Sheriff's Office/FOX 10 Phoenix)

Friends and family of Mustafa have been searching on their own for months, but have come up empty.

"We really need to have that proof," neighbor Diane Strand told FOX10 in June. "That's just going to finish this off, and help with any of the evidence they've already collected."