A sewage-like smell reads very differently depending on one thing: whether the house sat empty for a while, or the water is also cloudy and it hasn't let up.
Causes and what people typically do are based on published guidance from the EPA and state drinking-water programs, not guesses. The zip lookup pulls from EPA's public violation records (SDWIS) and a utility's own water quality report, hand-checked utility by utility rather than scraped.
This tool provides general information based on published EPA and utility data, and common causes reported by water quality professionals. It is not a substitute for laboratory water testing, a licensed plumber's assessment, or guidance from your water utility or local health department. WaterCheck does not guarantee the accuracy, completeness, or timeliness of the information provided and is not liable for decisions made based on it.
A sewage smell near a sink can come from two very different places, and only one of them is the water.
A simple test: fill a glass with cold water, step away from the sink — into another room if you can — and smell it. If the glass smells fine, the smell is coming from the drain, not your water.
Running water down drains that don't get used much, floor drains included, refills the trap. If the smell keeps coming back, a plumber can check the trap and the vent.
It depends on the pattern more than the smell itself. If it started after the house sat empty — a vacation, a rental turnover — it's almost always bacteria that built up in an unused drain or water heater, not something in the water supply, and running the taps usually clears it. If the smell is persistent and the water also looks cloudy or dirty, that combination is one water professionals treat as worth immediate attention.
A smell that comes and goes, especially after the house has sat unused overnight or over a weekend, points to a drain trap or water heater rather than the supply — bacteria builds up in those spots when nothing is running through them.
Yes. If you're on a well and the smell is persistent, proximity to a septic system is one of the sources professionals consider, especially alongside cloudy or dirty-looking water.
If it followed a stretch when the house sat empty, running every tap for 5+ minutes and cleaning drains with baking soda and vinegar typically clears it. If the smell keeps coming back or the water looks cloudy, many people contact their utility rather than keep working around it.
Usually that's sewer gas coming up through the drain, not anything in your tap water. The most common cause is a dried-out drain trap — the curved pipe under a sink, tub or floor drain holds a little water that blocks sewer gas, and it can dry out when a drain doesn't get used for a while. Running water down the drain for a minute usually refills it. If the smell keeps coming back, a plumber can check the trap and the plumbing vent. To tell drain from water, fill a glass, step away from the sink, and smell it.
Cities where I've read the utility's water quality report and EPA record by hand: