The latest trouble at the 450 N St. office tower began Sunday.
A hot water pipe failed while General Services officials were working on it and it gushed water onto several floors below, BOE spokeswoman Anita Gore said.
When Department of General Services staff started to repair the damage caused by what the BOE's director described as a "water event," they discovered mold on the first floor near the BOE's history room. That museum-like area is open to the public.
More mold was found on floors 2, 3, 6 and 7 at water damaged areas on the hallway side of the northwest stairwell in the building.
The BOE headquarters has been plagued by water seepage and mold trouble and litigation involving employees who claim they've been made sick by the mold.
A water hose failed on the building's 11th floor about a year ago and that floor has been closed ever since, Gore said.
The building's 22nd, 23rd, and 24th floors also have been closed for almost two years because of mold removal and remediation work, Gore said.
The new moldy areas have been taped over, closed and contained by DGS until more mold busting work and remediation steps can be taken to address trouble spots.
BOE consultant, Hygiene Tech, along with DGS consultants will continue testing at suspect locations and air quality throughout the building, the BOE told staff in a memo.
Gore said an estimated 60 BOE workers have resumed working today after taking Monday and Tuesday off, thanks to telecommuting arrangements and supplying them alternative work stations so they can perform their duties.
"We bring in more than $53 billion in revenue a year and that work has to continue, especially in these hard times," Gore said.
Three tax units affected have taken steps to ensure their public services are not interrupted, Gore said, and BOE is in the market for at least some new office space.