Recently, Chicago-based Zeller Realty Group bought the Umpqua Bank Plaza building and decided to switch janitorial contractors, bringing in one with a documented history of paying low wages and benefits. Now janitors in this building – like Maria Jimenez – are threatened by the possibility of losing their good jobs. If Zeller wants a new janitorial company to clean Umpqua Bank Plaza, it has several options that are responsible union contractors. “My name is Maria. I just had a baby and because I work for a union janitorial company with affordable healthcare, I did not have to pay a lot. I was also planning to care for him at home…