WESTPORT — A mold removal project initially estimated to cost $250,000 could cost $740,000 and has nearly depleted the school board’s carryover account.

So far, potentially toxic and common molds have been discovered in 19 classrooms and a first-floor hallway at Coleytown Middle School, with a second-floor hallway and 10 classrooms still to be tested.

“It will go over $500,000,” Elio Longo, director of school business operations, said, an assessment that has changed since March.

The carryover account — the district’s rainy-day funds — is down from about half a million dollars to only $90,691. The vast majority of the depletion is due to mold remediation and cleaning up the first-floor hallway will leave the account barren.

Longo said they plan to start removing mold from that corridor — which is adjacent to rooms 120-133 — when school lets out, around the third week of June. He estimates the cost to be under $100,000.

Over summer break, Hygenix, the company doing the work, will also be running air test samples on the second-floor hallway and the remaining 10 classrooms to determine if, and how much, mold removal they need to do there.

Longo said the school district has surplus in their operating budget and has asked both the school board and Superintendent Colleen Palmer to set aside $300,000 earmarked for more mold removal expenses.

“We will not have a firm number until test results are available,” Longo said, adding that he expects the worst case scenario to end in a total bill of $740,000, but his projections have been erroneous and conservative in the past.

The issue has plagued the school district since the mold was first discovered in August in more ways than just financial stress.

From August until February, the school district hired a convicted felon — Michael Zubarev, of Brooks Environmental Consulting — who pleaded guilty to first-degree larceny and conspiracy charges in 2010 for crimes he committed in 2005. Zubarev defrauded clients out of tens of thousands of dollars for falsifying soil test results. Westport Public Schools fired Zubarev February and subsequently hired Hygenix.

The school district has not gone back to retest Zubarev’s findings because they were consistent with other results in additional classrooms.

@chrismmarquette; cmarquette@bcnnew.com