first time posting...bu I've browsing around. I work in a small office and it's only 2 people with 2 bathrooms. In the early morning 8-9, the office gets this strong smell like sewage. Then after lunch...12:3-3:00 the smell comes back again. Our landlord suggested we pour bleach down our faucets and let the water run for a bit. (Our drains in the bathrooms were sealed closed by the landlords)

Pouring bleach doesn't seem safe to us, so we usually let the water run for 20-30 minutes. We are tired of this method. We are wasting water, and the smell comes back again. My boss has noticed that in her office, the smell is the strongest. She has one vent directly above her head...and the other vents are spread throughout the office. Only her vent/office seems to be emitting this foul odor.

What could it be? The bathrooms don't smell and the city waster dept. already checked everything out.

Any help is greatly appreciated!