we started noticing an occasional sewage smell in the basement. It comes and goes. I can't figure out its cause or source. I suspect it is somehow tied to the sump pump. The sump pump was replaced by roto rooter around a year ago. When I was there investigating, I moved a small rag and discovered to my surprise a big hole in the cover where the power cord is coming from.
Is this hole suppose to be sealed somehow? If I look inside I can see water. I imagine that could be the source of the smell.