Polls open at 7 a.m. and close at 8 p.m. for voting Tuesday on a Proposition 2½ override that if approved would allow this town of 4,400 people to add $320,000 to the Fire Department budget to hire four additional full-time firefighters. That would make it possible to have three people on duty instead of two, according to Chief Robert Spurr. “It’s a safety issue,” he said. The department currently has nine full-time firefighters and 19 paid, on-call firefighters, Spurr said, but the on-call members often are not available during the day. Town Clerk Jean Kopke estimated that passage of the override would cost the average residential taxpayer about $100 annually. In April 2013, voters rejected a $1.5 million override for a new school parking lot. The town has approved several overrides, including $7.6 million in 2008 for school, water, and road projects.