My friend just brought a house with a sewage ejector which only serves the bathroom in the basement. We always smell some kind of damp smell in the basement,particularly the area closed to the bathroom. Does it possibby cause by the venting problem of the sewage ejector?

We check all the pipes connected to the toilet and sink and we did not find any leaking.
What could possibly cause the smell?

If the sewage ejector needs to be vented, how do I install such mechanism?

Thank you for your help

Are you saying that you do not have a separate vent from the ejector pit? You should have two vents from the basement ejector system. A dedicated vent from the pit that doesn't connect to any other vent but runs outside by itself and a fixture vent that usually comes off the lavatory and vents the fixtures. These two vents CAN NOT be tied together but MUST be run separately. Waiting on your answer. Tom