Norwich — Replacing the temporary chiller unit with a new non-ammonia refrigeration unit and other equipment and improving energy efficiency at the 20-year-old Norwich ice rink would cost the city $680,000 based on plans submitted by an engineering consulting firm.

The City Council on Monday is expected to set a public hearing date on a proposed ordinance that would bond up to $680,000 for the combined projects designed to be the long-term fix to a year's worth of catastrophic mechanical failures and expensive temporary repairs.

If approved by the council at a future meeting following a public hearing, the new appropriation would bring the rink's total debt to the city to over $1 million including annual operating subsidies and money to cover costly system repairs over the years.

The new long-term plan was worked out between the Ice Rink Authority and the engineering firm McLaughlin Management and Design in a report dated Feb. 22.

Authority Chairman Francois "Pete" Desaulniers said the new system — including a projected budget of about $3,500 per year for maintenance — is expected to last 30 to 35 years.

Desaulniers is "very confident" this proposed fix would turn around the rink's fortunes, making it profitable and able to repay its debt to the city.

The alternative, Desaulniers said, is to close the rink and never recover the past debt.

"If they just shut it down, we're going to have another empty building, another YMCA," Desaulniers said, referring to the defunct Main Street YMCA, now a vacant, rundown building. "I truly believe (the rink) is another economic boost to the city. People come to the rink, they shop in our shops. They eat in our restaurants. It's a quality of life issue in Norwich."

Desaulniers, who also serves as council president pro tempore, co-sponsored the proposed ordinance with Alderman Mark Bettencourt, also a rink authority member.

Two years ago, the City Council revamped the authority and appointed Desaulniers to turn around its finances.

But as the authority was poised to finish the 2012-13 fiscal year with a profit, disaster struck. The aging ammonia-based cooling system failed on Feb. 13, 2013, causing an ammonia leak that forced an emergency evacuation. The rink was closed for weeks, but a short time after reopening in May, the system failed again, shuttering the rink from May 6 through early November, when it reopened with a temporary outdoor chiller unit hooked into the cooling system.

The temporary chiller proved more expensive than expected, costing about a $1,000 per day to run, including inflated utility bills.

Mayor Deberey Hinchey said she is torn between support for the rink and the high cost to be borne by taxpayers. But Hinchey echoed Desaulniers' comments that the city would never recover the debt if the rink closes.

"If we don't do it, you never get a chance to recover that money we put into it," Hinchey said. "And yet, we're asking people to pay that. It's a tough issue. It will be interesting to see what people have to say."

c.bessette@theday.com