Waterford — New estimates for remediation and demolition costs for the 90-year-old Cohanzie School on Dayton Road are roughly double what the town originally anticipated, according to Planning Director Dennis Goderre.

The Board of Selectmen approved Goderre’s request Tuesday to use $525,000 from the town’s undesignated projects fund to bridge the gap, in hopes that an additional state grant eventually would reimburse that appropriation.

“Move it along instead of waiting another year, because it’s going to go up again,” Selectman Paul Konstantakis said.

The town recently received a state grant of $457,500 to cover remediation costs, according to an April 30 letter from Goderre to First Selectman Daniel Steward.

Goderre said after the meeting Tuesday that the town already had spent some of the original grant on consultation and testing for hazardous materials.

Consulting firm Tighe & Bond recently estimated the cost of remediation and demolition at $849,948. Goderre said he learned of the higher estimate within the past two months.

He said during the meeting that if the town does not receive another state grant to cover demolition, the sale of the property would reimburse the town.

The property is listed at $950,000, according to Goderre.

Cohanzie School was left vacant in 2008 as part of a building project approved at a 2002 referendum that consolidated the town’s five elementary schools into three because of declining enrollment and increased operational costs.

The town intends to demolish two additions to the school, but officials hope a purchaser would find a way to use the original 1923 structure, Goderre said.

t.townsend@theday.com