San Antonio will have to come up with nearly $28 million over the next three years to pay for the new contract for firefighters. City staffers are proposing cuts to funding for VIA Metro Transit and environmental projects to help make the difference. They also recommended raising the fee for ambulance rides and better management of fire department overtime to close the gap. The San Antonio Professional Firefighters union will vote starting next week on the proposed contract that city negotiators agreed to last month.