I have a sewer odor in the basement in the area where my water line comes in(co-incidental?). The odor is worse when the washer is running, but fairly constant. I can also smell the same odor outside the house in the area adjacent to the water line, as well as in the back of the house in the area of the vent pipes. I dont smell the odor in the closet where my hot water heater, heat pump and floor drain are. Any ideas, suggestions, etc?