Those seeking to overturn New Canaan’s recently adopted summertime ban on gas-powered leaf blowers last week submitted petitions to the town with more than 1,000 total signatures calling for a referendum vote on the measure, officials say. “We now begin the lengthy process of checking the validity of the signatures,” Town Clerk Claudia Weber said. In all, 701 qualifying signatures are required in order to move the referendum process forward, Weber has said.