Home / Common plumbing problems / Sewage smell in water
Plumbing problem
Why does my water smell like sewage?
The short answer
University of Georgia Extension says a rotten egg, decayed, or sewage-like odor in household water is the result of bacterial activity, which can be in a drain, a water heater, or a well (UGA Extension). The first job is to find out which. A glass of water carried away from the sink answers the drain question in a minute.
What people usually report
A sewage or swampy smell at the kitchen or bathroom sink, sometimes stronger when the water first runs. Some people notice it at one fixture, others in the shower or across the house. On a private well, it matters whether the smell started after flooding or work near the well, since EPA lists both as reasons to test (U.S. EPA).
What official sources say the causes can include
- Bacteria in the drain. The odor rises from the drain while you run water, so it seems to come from the tap (University of Georgia Extension).
- Bacteria in the water heater. UGA lists the water heater among the places this bacterial activity happens; a smell in hot water only points there (University of Georgia Extension).
- The well itself. UGA also lists the well as a source. EPA and CDC treat any change in a well’s odor as a reason to test it (U.S. EPA; CDC).
EPA’s secondary standards list rotten-egg, musty, or chemical smells as noticeable effects of odor in water. EPA does not enforce these standards, and it notes that water with no odor is not necessarily safe to drink (U.S. EPA).
How to find out
- Glass test. Fill a glass at the sink that smells, step away from the sink, and swirl it. No odor in the glass means the drain is the source (University of Georgia Extension).
- Hot versus cold. Run each separately. A smell in only one narrows it to the water heater or the supply.
- Test the water if the smell is in the water itself:
- On public water: read your utility’s Consumer Confidence Report. EPA requires community water systems to send one to customers every year by July 1, and you can look yours up with EPA’s CCR search tool or call the utility (U.S. EPA).
- For a lab test: EPA links each state’s drinking water laboratory certification program, which lists certified labs you can pay to test a sample (U.S. EPA).
- On a private well: EPA and CDC both say to test at least once a year for total coliform bacteria, nitrates, total dissolved solids, and pH, and to test again after any change in taste, odor, or color (U.S. EPA; CDC). EPA does not regulate private wells; your state or local health department can help.
A drain that smells is a drain-cleaning question; see what drain cleaning costs.
Affiliate links
Try this while you wait: screening tools
A home kit or gauge can tell you whether something is worth a closer look. It is a screening tool only. It does not replace a test from a state-certified laboratory or an inspection by a licensed plumber.
- Well water bacteria test kits on Amazon →Screens for coliform bacteria. A positive result needs a certified lab and your health department.
- Home drinking water test kits on Amazon →Multi-item strips for a first look.
As an Amazon Associate we earn from qualifying purchases. Buying through these links never changes your price. We have not tested these products, and the links open an Amazon search, not a single recommended item.
Local help
Who to contact
If you are on a public water system, your water utility is the first call for anything that affects the water itself. Its phone number is on your bill and in its annual water quality report.
For work on the pipes and fixtures inside your home, hire a licensed plumber and confirm the license before work starts. Our guide to choosing a plumber covers what to ask. License lookups for the areas our city pages cover:
- FL: Florida Department of Business and Professional Regulation (DBPR)
- IA: Iowa Plumbing and Mechanical Systems Board (PMSB), administered by Iowa DIAL
- MO: Kansas City, MO City Planning & Development (plumbing license, city-issued)
- NE: City of Omaha Building and Development Division (plumbing license, city-issued; Nebraska has no statewide plumbing board)
- NV: Nevada State Contractors Board (NSCB), Classification C (plumbing)
- OK: Oklahoma Construction Industries Board (CIB)
- TX: Texas State Board of Plumbing Examiners (TSBPE)
Elsewhere, search your state’s plumbing or contractor licensing board. Some cities issue plumbing licenses themselves.
Advertising partner
Get quotes from local pros
Angi is a national marketplace for home services. You describe the job, and water treatment contractors who work in your area contact you with their own quotes. Requesting quotes is free and you are never obliged to hire anyone.
Angi pays us a referral fee for a completed service request. The fee comes from Angi, not from you, and it does not change the cost figures on this page.
Keep going
Related costs and guides
Common questions
Sewage smell in water questions
How do I get rid of a sewer smell in my water?
Find the source first. University of Georgia Extension’s glass test (fill a glass, step away from the sink, swirl it) shows whether the smell is in the water or coming up from the drain. A smelly drain is a drain problem. A smell in the water itself, especially on a private well, is a reason to test: EPA and CDC both say to test a well after any change in odor.
Why does only one sink smell like sewage?
A smell at one fixture often comes from that fixture’s drain rather than the water supply. University of Georgia Extension says that if water from that tap has no odor once you carry the glass away from the sink, the problem is in the drain.
Should I test my well if the water smells like sewage?
Yes, according to EPA and CDC guidance for private wells. Both list a change in odor as a reason to test, on top of the yearly test for total coliform bacteria, nitrates, total dissolved solids, and pH. Your state’s certified lab program or local health department can tell you where to send a sample.
Sources and limits
- Washington State Department of Health, Sewage Spills: Cleaning Them Up. Checked 2026-10-05.
- Wisconsin Department of Health Services, Air: Sewer Gas. Checked 2026-10-05.
- University of Georgia Extension, Your Household Water Quality: Odors in Your Water (C1016). Checked 2026-10-05.
- U.S. EPA, Private Drinking Water Wells: Protect Your Home's Water. Checked 2026-10-05.
- CDC, Guidelines for Testing Well Water. Checked 2026-10-05.
- U.S. EPA, Secondary Drinking Water Standards: Guidance for Nuisance Chemicals. Checked 2026-10-05.
- U.S. EPA, Consumer Confidence Report (CCR) information for consumers. Checked 2026-10-05.
- U.S. EPA, Find your local Consumer Confidence Report (search tool). Checked 2026-10-05.
- U.S. EPA, Certification programs and certified laboratories for drinking water, by state. Checked 2026-10-05.
This page summarizes guidance published by the agencies and organizations listed above. It is general information, not a diagnosis of your home or your water. Guidance can change, so check the linked source, your water utility, or your local health department before acting on it. PlumbingRepairCost is not affiliated with any agency named here. Spotted an error? Email hello@plumbingrepaircost.com and we will check it against the source.