I have a serious and annoying problem in my basement. It seems that whenever the shower in the basement is turned on and when the toilet is flushed, there is a strong sewage odor that becomes apparent. I think it is coming from the sump pump, but I'm not entirely sure. Does anyone know what causes this and how it can be fixed? It is quite embarrassing, especially when I have guests over. I would appreciate all responses. If you need more info, I can provide that also. Thanks.

Are we talking sump pump or ejector pump?

After researching the difference between the 2, it is certainly the ejector pump. Please help. It will honestly be the best Christmas gift ever. I can't stand the sewage stench after someone flushes the toilet in the basement or showers.

Also, I will be checking this daily now so I will stay current on my responses!

It only does it when the two are used at the same time? Are both vent pipes connected to each other? Could you be getting backup into the shower as a result of the volume of water with both running? What is the order shower or toilet closest to the drain pump?