Sewer smell in basement

[bpolson2]

Every once in a while my basement will get that sewer gas smell in it. I do seem to have proper venting in it but it seems to happen once in a well. I had a plumber come out to the house and check the pump and all the gaskets were replaced and sealed. I have two floor drains in the basement and was told that it may be coming from them. Could that be possible? Is there any way to prevent the smell from entering the basement?

 

[Plumber2000]

Make sure the floor drain traps have water in them.