The city of Lexington will pay firefighters $17.7 million for back overtime and pension. The payment stems from a 2005 lawsuit filed by Lexington firefighters alleging that the city owed them money for overtime worked. The details of the settlement are being worked out and must be approved, city and firefighter union officials said. The Urban County Council gave preliminary approval to making the money for the settlement available at the council’s Tuesday work session. City officials have previously said any surplus or additional money from the fiscal year that ended June 30 would be used to pay for the settlement. That means there will be no surplus money to spend this year.