Halifax Transit and Local 508 of the Amalgamated Transit Union have reached a settlement for overtime back pay worth $256,000.

The transit union represents 131 people who maintain and repair the city's fleet of buses.

"It's the biggest settlement in our history," said Ken Wilson, president of the union local. "We've been here for 109 years."

The dispute started in 2012 over a clause that gave the mechanics an hour break between an overtime shift and regular shift. The union insisted if no break was given, the workers should get time and a half for all their hours.

The municipality said the language in the collective agreement was "ambiguous."

The union grieved the matter and it went to mediated arbitration, where a compromise was reached.

Payouts range from $11K to $76

"We agreed to a discounted amount of 78 per cent," said Wilson. "Some guys are getting $11,000, some are getting $76. It varies by employee and how much overtime they worked."

The settlement covers a period from May 2012 to January 2017. The mediated agreement also keeps the intent of the article that outlines the break for the current contract and the next one that is negotiated.

The municipality said in a statement the settlement represents the payment of deferred overtime costs and not additional new costs.