Quick Answer:
Run water at the kitchen sink for about a minute to refill the trap. If the smell continues, listen for gurgling when toilets flush and note when the odor appears—these clues point more to a vent or trap problem than to the water itself. If you detect strong sewer gas, call a plumber.
Why This Happens
City water or sewer outages can change system pressure and allow air to move through drains and vents in unusual ways. That movement can siphon water out of traps or let sewer air push past weak seals. The result is a sewer-like odor in the kitchen even though the water coming from the tap is fine. Pressure swings during or after the outage are common triggers.
Step-by-Step What to Do
Step 1 — Refresh the sink trap
Run cold and then hot water at the sink for about one minute to refill the P-trap and clear any light odors that come from evaporated trap water.
Step 2 — Check the disposal
Run the disposal with plenty of cold water for 20–30 seconds to flush food particles. If the smell seems metallic or different from sewer, treat it as a disposal issue rather than a sewer issue. For more on disposal-specific problems, see Disposal smells metallic.
Step 3 — Listen for venting problems
Flush each toilet in the house while someone stands near the kitchen sink. If you hear gurgling or bubbling from the sink drain or other fixtures, the venting or trap seals may have been affected by the outage.
Step 4 — Note timing and location
- Record when the smell appears (immediately after outage, only when appliances run, or continuously).
- Check other drains—if multiple fixtures smell, the problem is more likely a vent or main trap rather than a single sink drain.
If the odor started after long downtime or winter shutoff, similar issues can occur; see guidance for post-shutoff sink odors at Sink smells after winterization.
Step 5 — If odors persist
- Try pouring a cup of water down unused drains to ensure traps are filled.
- Ventilate the kitchen by opening windows and running fans while you troubleshoot.
- If smells remain despite full traps and no gurgling, timing and persistence suggest a vent or trap seal issue that needs inspection.
What Not to Do
- Don’t treat outage-related odors as only a ‘water quality’ problem—pressure events can expose vent/trap issues; if you smell strong sewer gas, a plumber is appropriate.
- Don’t ignore strong or persistent sewer smells—these can indicate a broken trap seal, damaged venting, or a sewer line problem.
- Don’t pour harsh chemicals down the drain trying to mask odors—these can damage pipes or harm septic systems.
When to Call a Professional
- If you detect a strong sewer gas odor that won’t go away after refilling traps and ventilating.
- If you hear persistent gurgling from multiple fixtures or toilets that seem to siphon or burp when flushed.
- If you suspect a damaged vent stack, cracked trap, or sewer line issue—these require a plumber’s inspection and repair.
Safety Notes
- Strong sewer gas can be hazardous—leave the area and get fresh air if the smell is intense.
- Do not use open flames to test for odors or enter confined spaces without proper precautions.
- Ventilate the space and avoid prolonged exposure while you wait for professional help if needed.
Common Homeowner Questions
- Why did this start after the outage? Pressure changes during outages can siphon traps or push sewer air through weak seals.
- Will running water fix it? Often yes for light smells—running water refills traps and stops odors caused by evaporation or short siphoning events.
- When is a plumber needed? Call a plumber for strong sewer gas, persistent odors after traps are refilled, or when you hear gurgling from multiple fixtures.