First, if the odor is a rotten egg smell, please leave the home and call your natural gas provider to make sure the odor is not a gas leak. If natural gas is not the issue, check to make sure all drains in your home have water in them, and don’t forget the washing machine drain and basement floor drains. Typically, a cup or two of water will fill up the trap in the drain and stop any sewer smell from escaping. (For infrequently used drains try adding a tablespoon of vegetable oil along with the water to the drain. The oil will act as a barrier and keep the water from evaporating so quickly.) If odors persist, contact Johnson County Wastewater at 913-715-8600 for help diagnosing the problem. They will also be able to tell you if JCW crews are cleaning lines in your area which could cause a temporary odor.