Norwich — An ammonia leak at the Norwich Ice Rink Wednesday night caused serious equipment damage to the rink’s compressor and cooling system, costing an estimated $25,000 to $50,000 in damage and forcing the rink to close for 10 days to two weeks, rink officials said Thursday.

No injuries were reported in the leak, which forced evacuation of the rink at 8 p.m. Wednesday and brought environmental monitors from the state Department of Energy and Environmental Protection to the scene overnight to monitor air quality.

The rink building at 641 New London Turnpike was cleared to reopen Thursday morning, but rink manager Mia Sanca said all activities, including a women’s hockey tournament, a youth hockey tournament, high school hockey games, practices, skating programs and lessons, are canceled. The damage costs do not include lost revenue from rink rentals.

Ice Rink Authority Chairman Francois “Pete” Desaulniers has scheduled a special authority meeting for 10 a.m. Saturday at the rink building to discuss the problems.

Desaulniers said salt water has contaminated the cooling system and must be flushed out. The rink’s compressor and cooling system either will have to be replaced or repaired. Another issue is whether the contaminated liquid can be sent to the Norwich sewage treatment plant or whether it must be disposed of as hazardous waste, adding to the costs.

Norwich Public Utilities officials were at the rink Thursday to take samples of the liquid to see if the sewage treatment plant could handle it, NPU spokesman Michael Hughes said.

“If they can’t take it, then we have to hire a contractor, and the cost doubles and triples,” Desaulniers said.

The financially troubled, city-owned rink has been in a turn-around year, expected to finish with a small profit by June for the first time in about 10 years.

City Comptroller Joseph Ruffo said he has contacted the city’s insurance carrier to assess how much of the equipment damage and repair costs and revenue losses will be covered. The rink is insured for up to $1 million in losses, Ruffo said.

“We’re optimistic the loss will be offset by insurance,” he said.

The equipment failure came at a time when the rink authority is considering a proposal by Michigan-based Thermo Source to install a $1.1 million geothermal system that would run the cooling equipment to freeze the ice without need of ammonia and would use the excess heat to run hot water systems for the building’s use.

Company officials made a presentation last week to the City Council during an informational meeting. The system would involve drilling 15 feet down into the ground near the rink and extending a horizontal line 500 feet long beneath the parking lot behind the rink.

The ammonia leak was detected at 8 p.m. Wednesday when an ammonia alarm was tripped, prompting evacuation and overnight monitoring by firefighters and state emergency environmental response crews.

East Great Plain Fire Chief Patrick Daley said he called on a partial response by the regional hazardous materials team that included Norwich and Mohegan Tribal fire departments. The responders were equipped with ammonia monitoring equipment.

Daley said crews were able to find, isolate and secure a small leak, discovered in one of the coolant pumps used as part of the refrigeration process. The building was ventilated.

Staff writer Greg Smith contributed to this report.

c.bessette@theday.com