Every drain in your home’s sewer system should have a “p”-shaped trap (plumbing trap or p-trap) that is properly vented, this includes showers, bathtubs, utility sinks, and floor drains. The p-traps on each drain “traps” water, creating a seal, or barrier, that will keep sewer gas out of your home. If one of these drains is rarely used, such as in a guest bathroom, the water creating the protective seal will eventually evaporate. This is a formula for trouble that can allow stinky sewer gas to seep into your home. Simply pouring some water into each of the seldom used drains should solve the problem. If odors persist, please call the District at 925-228-5635 for assistance.