By Julie Shapiro
LOWER MANHATTAN — The 9/11 memorial is about to get even greener.
Over the next month, workers will plant an additional 30 swamp white oak trees on the memorial plaza at the World Trade Center site, the Port Authority announced Thursday.
The young oaks, which have been growing in a New Jersey nursery, will join the 16 trees already planted at the memorial over the summer. Eventually, 400 trees will blanket the 8-acre plaza, surrounding the waterfalls in the footprints of the original Twin Towers.
Steve Plate, the Port Authority's director of World Trade Center construction, said Thursday that the trees were just one sign of recent progress at the site.
During a Port Authority board meeting, he also announced that steel for 1 World Trade Center, formerly called the Freedom Tower, has reached the 40th floor and said that the building is rising at the rate of one floor per week.
Work on the south side of the site is also moving forward. On Thursday, the Port approved a $46 million contract to install all the steel for the Vehicle Security Center. The contract, awarded to W&W Steel Company of Oklahoma City, came in 23 percent under budget and will help get the underground garage open in 2013, Plate said.
The Port is also ramping up security measures in anticipation of the memorial opening on the 10th anniversary of the attacks. The Port allocated $5 million on Thursday to outfit the Trade Center site with more surveillance cameras and iris scanners leading up to 9/11/11.
The Port will monitor all the security information from an interim facility at 115 Broadway, a couple of blocks away, said Steve Coleman, Port spokesman. Eventually, the security center will move to the World Trade Center itself, somewhere below ground on the east side of the side, Coleman said.