Union Local 609 in Clinton has filed a grievance over firefighters lending a hand with a construction project at the station.Saying union contracts prohibit union members from participating in major projects, the grievance was filed in October after renovation work started at one of the Clinton fire stations. Chief Mark Regenwether says they’ve been working on bedrooms, living quarters and the kitchen in order to hold costs down. The grievance says firefighters during their regular shifts should only be doing routine maintenance chores. The chief says the renovation work’s going on during daytime hours. A grievance hearing will be held a week from this Friday with a mediator, at Clinton City Hall.