The following lists the major work taking place currently at the site:

Freedom Tower:

Installation of tower-foundation steel columns (two cranes on site)

• Installation of tower-foundation steel columns (two cranes on site); superstructure reached grade in July 2008
• Pouring concrete for the foundation and rebar installation for core and sheer wall
• Utility installation and tie-ins

WTC East Bathtub:

• Excavation of the Tower Two site through October 2008; crews are working double shifts
• Concrete pours began at the Tower 4 site in July 2008
• Major excavation of the south half of the east bathtub (sites of Towers Three and Four) from July 2007 through February 17, 2008; Silverstein Properties's construction team is mobilized and preliminary construction is underway
• Structural support and excavation under the 1 train box, which runs through the WTC site along Greenwich Street

National September 11^th Memorial and Museum:

• Slurry wall reinforcement
• The "Survivors Stairway" was relocated from its original location to its permanent home in the underground Memorial site on July 19, 2008
• Steel installation began September 1, 2008
• Concrete installation begins in early 2009
• Memorial crews plan to remove the ramp into the WTC site in September 2008 to continue construction on the south footprint
• The World Trade Center Memorial Foundation announced on April 9, 2008 that it reached its $350 million private fundraising goal

Tower 4

• Excavation
• Foundation work including concrete pours

Tower 3

• Excavation; rock blasting resumes mid-September 2008
• Foundation work

130 Liberty Street/Deutsche Bank Building Deconstruction:

• The crane will be in use starting September 18th to remove materials from the building's roof
• Demolition of portions of floors that were damaged in the August 2007 fire is taking place. The work will occur inside the building from the 14th to 20th floor and will involve potentially noisy machinery
• Full decontamination is underway as of May 2008; no end date has been announced
• Abatement continues downward and crews are currently working downward lower floors

Air-quality testing at the building continues, with 12 sampling sites in the building's immediate vicinity. Air monitoring reports are available here; more information about air monitoring is available here and on the LMDC's website.
Source: LowerManhattan.info