The city has collected about 60 dump truck loads of debris from construction areas around the World Trade Center site over the past two and a half years that will be sifted for fragments of 9/11 victims' remains, New York City officials announced Friday.
The debris has been collected from the World Financial Center, West Street and a lot near Liberty Street since the last sifting operation in mid-2010.
The material amounts to 590 cubic yards -- 38 from the WTC, 13 from the western edge of the southbound lanes of West Street and 539 from the Liberty Street area, where four pieces of possible human remains have already been found.
The material will be combed for about 10 weeks starting Monday at a mobile sifting unit set up on Staten Island, city officials said.
Any human remains will be analyzed by the medical examiner's office for possible matches to 9/11 victims. Of the 2,750 people killed at the trade center, 1,634 have had remains identified.
"We will continue DNA testing until all recovered remains that can be matched with a victim are identified," Deputy Mayor Cas Holloway wrote Friday in a memo to Mayor Bloomberg.
The city expanded its search for remains of trade center victims in 2006, when several bones were found in a manhole.
Since the discovery of the manhole bones, the city has sifted debris from various construction sites and subterranean areas surrounding the 16-acre trade center site. More than 1,800 pieces of potential human remains have been found.
The office has made 34 new identifications since 2006, and hundreds of fragments of remains have been matched to people who were already identified.