Have you ever turned on your faucet only to find that your water smells like sewage? It can be unsettling and raise immediate concerns about safety and cleanliness. In most cases, this odor—often compared to rotten eggs—is caused by hydrogen sulfide gas produced by bacteria in drains, hot water heaters, or well systems.
The good news is that while the smell is unpleasant, it rarely indicates dangerous contamination in municipal water supplies. By identifying the cause and following the right steps, you can fix the issue and prevent it from happening again.
This guide explains the causes, diagnostic tests, health concerns, solutions, and prevention strategies for smelly water.
Quick Facts: Why Does My Water Smell Like Sewage?
What Hydrogen Sulfide Means for Your Water
- Hydrogen sulfide gas (H₂S) is the most common cause of a sewage or rotten egg smell.
- You can detect it at 0.5 parts per million (ppm). By 1–2 ppm, the odor is strong.
- It forms when sulfate-reducing bacteria grow in low-oxygen areas of plumbing or water systems.
Most Common Household Sources
- Drains: Food, soap, and organic debris feed bacteria that release gas.
- Hot water heaters: Especially if below 120°F or unused for days.
- Private wells: Often affected by sulfur bacteria or organic matter.
- Faulty plumbing parts: Vent pipe problems or wax ring leaks near toilets.
Is My Water Dangerous?
- At typical household levels, the odor itself isn’t toxic, but it does flag bacterial activity.
- If the smell is present throughout the home, especially with well water, professional testing is recommended.
How to Diagnose Where the Smell Comes From
Finding the real source is the first step to solving the problem. Knowing whether the sewage smell you’re experiencing comes from the plumbing or the water supply can save time and effort. Here’s how to check if your water smells like sewage:
Does the Smell Come From Hot or Cold Water?
Fill two glasses with water—one from the cold tap and one from the hot. If only the hot water smells, the water heater is likely the cause. This test helps determine whether the water smells like rotten eggs only when heated. Once identified, you can take targeted steps to clean or flush the heater to improve home water quality.
The Drain vs. Water Source Test
Fill a clean glass of cold water and step away from the sink before smelling it. If the odor goes away, the drain is the problem. If it persists, the issue may lie in the water supply, so it’s a good idea to test your water to check for bacteria or sulfur compounds that cause a foul smell.
Other Signs It’s the Plumbing, Not the Water
If odors only come from certain faucets, or if you notice a foul smell or sewer gas near toilets or drains, the problem is likely in the pipes rather than the water supply. Gurgling or clogged pipes can also indicate that trapped debris is feeding bacteria, causing the water smells like rotten eggs in localized areas.
Why Does My Water Smell Worse After Vacation?
Still water in pipes combined with a warm environment promotes bacterial growth. When you return from vacation and run the hot water, the odor can be stronger. This is often why the sewage smell seems more intense after leaving your home for several days. Regularly flushing unused taps can help reduce bacterial buildup and prevent water smells like sewage from lingering.
Top Household Causes of Sewage-Like Water Odor
Bacteria in Drains (Most Common)
Organic material like food scraps and soap residue can build up over time, feeding bacteria that release gases. This is often why your water from faucet smells like sewage near sinks. The odor is usually strongest close to the drain and disappears after cleaning. Using a water filter or enzymatic cleaner can help prevent recurring odors and reduce a musty smell in your home.
Hot Water Heater Issues
Water heaters set too low or left unused for several days can foster bacterial growth. Magnesium anode rods may react with bacteria, creating a smell of sewage or unpleasant odor in hot water. Maintaining proper temperature and flushing the tank regularly addresses water smells like sewer issues. For targeted solutions, understanding water smells like sewage how to fix is key.
Well Water Contamination
Sulfur bacteria naturally occur underground, and their presence of sulfur bacteria can make well water smells like sewage if the well isn’t cleaned or disinfected regularly. The odor often has a characteristic note like sulfur. Shock chlorination or installing a filtration system can help eliminate the smell and improve water safety.
Rare Causes: Sewage Backups & Broken Seals
Sewer line blockages can push gases into your plumbing, causing water smells like sewage even if the water itself is safe. A broken toilet wax ring can also allow sewer gases to enter rooms, producing a foul smell or smell of sewage in localized areas. Professional inspection is usually needed to permanently resolve these issues.
Is It Safe to Drink Water That Smells Like Sewage?
Health Thresholds of Hydrogen Sulfide
Safe drinking water standards do not list health risks at the low levels typically found in household water. Even if you notice a slight odor, it is usually a nuisance rather than a danger. Based on WHO guidelines, low-level hydrogen sulfide is not considered a health hazard, though it can indicate bacterial presence in water systems. High concentrations (above 50 ppm in air) can irritate the lungs and eyes, but these levels are far higher than what is found in normal home water. For most households, the smell serves more as a signal of bacterial activity than a direct health threat.
Short-Term vs. Long-Term Health Risks
Small amounts of hydrogen sulfide in water are primarily a nuisance and do not pose immediate health hazards. However, the presence of bacteria that produce this gas indicates microbial activity, which can support the growth of other unwanted organisms over time. Long-term exposure to untreated well water with high bacterial activity could increase the risk of gastrointestinal issues if contaminants are present.
Can Sewage-Smelling Water Make Me Sick?
If the odor originates from drains, it is usually harmless and limited to the air around the sink. When water smells like sewage from the water supply, particularly in wells, it requires testing to ensure no harmful bacteria or other contaminants are present. Even minor contamination can affect taste and smell, but proper treatment or filtration can make the water safe for household use.
Municipal vs. Private Well Safety
Municipal water supplies are rarely contaminated, and utility providers quickly investigate complaints when odors are reported. Private wells, however, should be tested at least annually for bacteria, sulfur, and nitrates to ensure safe drinking water. Regular monitoring helps identify issues early, prevent foul smell problems, and maintain overall water quality.
Step-by-Step Troubleshooting Guide
Drain Cleaning Checklist
- Pour boiling water down the drain.
- Scrub with a brush and disinfectant.
- Use an enzymatic cleaner for recurring build-ups.
Hot Water Heater Flush Protocol
- Drain your heater and refill it with fresh water Completely draining your water heater removes accumulated sediment and bacterial buildup that can cause odors. Refilling with fresh water ensures that the system starts clean, reducing the chances that your water smells like sewage or develops a foul smell.
- Temporarily raise the temperature to 140°F (carefully, and return it to 120°F later) Raising the water temperature temporarily kills bacteria that may be producing a smell like rotten eggs. Be careful to avoid scalding, and return the temperature to 120°F afterward for safe household use.
- Replace the magnesium anode rod with an aluminum/zinc version if the issue returns Magnesium anode rods can react with bacteria in the tank, producing hydrogen sulfide gas and causing your water from faucet smells like sewage. Replacing it with an aluminum/zinc rod reduces this chemical reaction and helps maintain odor-free water.
Testing Well Water
- Use a home test kit for sulfur bacteria and iron bacteria Home test kits allow you to quickly check for common contaminants that can cause well water smells like sewage or a foul smell. Regular testing helps you detect early signs of bacterial growth or mineral buildup, so you can take corrective action before the odor becomes severe. It also gives peace of mind that your home water is safe for drinking and everyday use.
- For accuracy, send a water sample to a certified lab While home kits are convenient, sending a sample to a certified laboratory ensures precise measurement of bacteria and mineral levels. Lab results can confirm the presence of sulfur bacteria and identify any other contaminants that might be affecting water quality. Accurate testing is essential for determining the best treatment method, whether that’s filtration, chlorination, or other remediation.
When Professional Help Is Needed
- Odor appears in all faucets If the sewage-like odor is present in every faucet of your home, it usually indicates a systemic problem rather than a localized drain issue. This widespread water smells like sewage problem may involve the main water supply or plumbing system, requiring professional inspection to identify the source and implement a permanent fix.
- Suspected sewer line backup A blocked or damaged sewer line can push gases into your plumbing, causing a foul smell throughout the home. Immediate professional intervention is essential to prevent further contamination, protect your plumbing system, and ensure that your home water remains safe for use.
- Recurring well contamination despite treatment If well water continues to have an odor even after regular treatment, it suggests the presence of sulfur bacteria or other contaminants that need expert attention. Professional water treatment specialists can assess the situation, recommend filtration or disinfection methods, and ensure that the well water smells like sewage is permanently addressed.
Long-Term Solutions & Prevention
Regular Maintenance Practices
- Regular Maintenance Practices Performing regular maintenance is key to preventing water smells like sewage from returning. Clean drains monthly to remove organic buildup that feeds bacteria, and this simple step helps reduce a foul smell near sinks.
- Flush water heaters every 12 months It’s important to flush the water heater annually to remove sediment and bacterial buildup that can cause odors. Regularly flushing not only eliminates the hydrogen sulfide responsible for a smell like rotten eggs, but also prolongs the life of your water heater. Flushing the water heater keeps your home water safe, fresh, and pleasant to use.
Preventing Water Heater Odors
- Always keep heater at 120°F or higher Maintaining the correct water heater temperature helps prevent bacterial growth that can cause a foul or unpleasant smell in your hot water. Proper temperature control ensures that bacteria inside your pipes and inside your water heater are minimized, keeping your home water safe and odor-free.
- Inspect and replace anode rods as needed Magnesium or old anode rods can react with bacteria, creating an unpleasant smell reminiscent of rotten eggs. Regular inspection and replacement help maintain your water heater’s efficiency. For wells with bacterial issues, using a water heater with a chlorine injection system can further reduce odor and protect your household from sulfur-related smells.
Well Maintenance
- Shock chlorinates the well when needed Occasionally performing a shock chlorination can help kill sulfur bacteria and temporarily remove the smell of rotten eggs from your well water. This method is especially useful when you notice that the water may carry strong odors after periods of non-use.
- Use continuous disinfection systems if bacteria return If sulfur or iron bacteria reappear frequently, installing a continuous disinfection system can stop the cycle. Without proper treatment, these microbes can make it seem like there is sewage in your water, even though the source is bacterial activity.
- Keep well caps secure and test yearly A tightly sealed well cap prevents insects, dirt, and organic material from entering the well and contaminating the supply. Experts recommend testing your well water every year to catch problems early, since untreated water may develop unwanted odors or harbor harmful microbes.
Stopping the Sewage Smell Permanently
- Stop bacteria growth The key to ending recurring odors is eliminating conditions that allow bacteria to grow in your plumbing or water system. Regular cleaning and disinfection help prevent the buildup of organic matter that produces the unpleasant smell and taste in water.
- Remove old plumbing components Aging pipes, corroded fittings, or worn-out water heater parts can often be the hidden source of the smell. Replacing these outdated components not only removes the odor but also improves water quality and flow.
- Set up a maintenance schedule Creating a consistent routine for drain cleaning, heater flushing, and water testing keeps bacteria in check. With scheduled care, you can avoid conditions that allow bacteria to grow and maintain water that’s fresh in both smell and taste.
Using Water Filtration Systems
In addition to plumbing maintenance, installing a water treatment system adds another layer of protection for your home’s water supply. Common filters, like sediment and activated carbon, remove large particles and odors, but for households seeking high-quality water and to completely prevent water smells like sewage, an RO (reverse osmosis) filtration system is ideal. RO systems can remove dissolved minerals, bacteria, viruses, and sulfur compounds, improving both the safety and taste of your water. By choosing to install a water filtration system with RO technology, you ensure your household consistently enjoys clean, odor-free water.
Real-World Case Studies & Research Evidence
Municipal Utility Reports
County utilities report most water odor complaints come from drains, not city water. Residents are encouraged to test their water if odors persist, but in most cases, the problem can be resolved with proper drain cleaning or maintenance.
Homeowner Experiences
- Many reported on forums that simply cleaning drains or flushing heaters solved their problem. Residents often noticed that the water smells like sewage or had a smell of rotten eggs near certain faucets, but the issue disappeared after maintenance.
- The “glass test” often confirmed that the odor wasn’t actually in the water but originating from the sink or drain. These real-world experiences highlight that, in most homes, simple routine maintenance can quickly resolve unpleasant water odors.
University Extension Guidance
University extension programs recommend testing hot versus cold water and running the “smell test” away from drains to accurately identify the source of odors. This method helps determine whether the water smells like sewage due to plumbing issues or actual contamination. They also advise that homeowners document recurring odors and, if needed, send water samples to certified labs for further analysis.
Example: Post-Vacation Smell
A family noticed the smell of rotten eggs in their water after returning from a 2-week vacation. The odor was strongest when running hot water, indicating bacterial growth inside the water heater. By flushing the hot water heater and replacing the anode rod, they were able to eliminate the odor.
When to Escalate the Issue
Signs of a Plumbing Emergency
- Sewer odor spreads across multiple rooms.
- Backups or gurgling drains appear.
When to Contact Municipality
- Neighbors have the same issue.
- Only cold water smells.
Landlord vs. Homeowner Responsibilities
- Tenants should report sewage smells to landlords immediately for investigation.
Do I Call the City if My Water Smells?
- Yes, if everyone in the building or neighborhood has the problem.
Action Plan: How to Fix Sewage Smelling Water (Checklist)
- Drain issue? → Clean, scrub, and disinfect.
- Hot water problem? → Flush heater, check temp, replace anode.
- Well water? → Test, disinfect, and consider a filtration system.
- Sewer gas? → Call plumber immediately.
- Whole-house problem? → Notify utility provider.
Conclusion & Key Takeaways
- If your tap water smells like sewage, don’t panic—most cases are plumbing-related, not contamination.
- The smell usually comes from drains or hot water heaters.
- Drinking water with a mild odor is generally harmless, but well owners should test regularly.
- Prevent problems by cleaning drains, flushing heaters, and keeping water systems disinfected.
- Call a plumber or city utility team if the odor is widespread or severe.
FAQs
1. How do you fix tap water that smells like sewage?
If your tap water smells like sewage, the first thing to do is usually check your drains. A lot of times, the smell isn’t actually in the water—it could just be food, soap, or other gunk stuck in your sink or pipes giving off a nasty odor. Cleaning out your drains with boiling water, scrubbing, or using an enzymatic cleaner often does the trick. If it’s the hot water that smells, try flushing your water heater and checking the anode rod to get rid of the bacteria causing that rotten egg smell. For well owners, it’s smart to test your water for sulfur bacteria or other contaminants, since the odor might mean bacteria in the supply itself. And if nothing works, calling a plumber is your safest move—they can check your plumbing, look for sewer line issues, and suggest any extra treatment or filtration you might need.
2. Is it safe to drink tap water that smells like sewage?
In most cases, yes—it’s usually just an unpleasant smell rather than a real health risk. If the odor comes from your drains or water heater, the water itself is generally safe to drink, even if it smells like rotten eggs. That said, the smell is still a good signal that some bacteria may be present, so it shouldn’t be ignored. For people with private wells, it’s especially important to test your water for sulfur bacteria, nitrates, or other contaminants, because the odor might indicate bacterial growth in the water supply. If the sewage-like smell is persistent and appears in multiple faucets, taking a sample to a certified lab or calling a professional plumber can give peace of mind. Regular maintenance and monitoring ensure your water stays safe, clean, and more pleasant to use.
3. How do I get rid of sewer smell from water?
The first step is usually to check your drains, because a lot of times the smell isn’t really coming from the water itself—it’s just food, soap, or organic material stuck in your sink or pipes. Cleaning drains thoroughly with boiling water, scrubbing, or an enzymatic cleaner can make a big difference. If the odor comes from hot water, flushing your water heater and checking or replacing the anode rod can get rid of the bacteria that cause the rotten egg smell. For well owners, the solution might involve disinfecting the well or even installing a water treatment system to remove sulfur bacteria and other contaminants. Regular maintenance and monitoring, like cleaning drains and flushing the heater, help prevent the smell from coming back and keep your home water safe and fresh.
4. Can a plumber fix smelly water?
Absolutely. A plumber can help if your water smells like sewage, rotten eggs, or has any other foul odor coming from your home’s plumbing. They can identify whether the smell is caused by clogged drains, leaks, broken seals, or sewer gas entering your pipes. If the odor is coming from your hot water, they can inspect your water heater, flush it safely, and check the anode rod for bacteria that produce the rotten egg smell. Plumbers can also advise on more long-term solutions, such as disinfecting wells, replacing old pipes, or installing water treatment systems if needed. Essentially, if the problem persists despite basic maintenance, a professional plumber can pinpoint the source and make sure your water is safe, fresh, and free from unpleasant odors.
5. Is it safe to shower in water that smells like sewage?
For the most part, yes—it’s usually more of an unpleasant smell than a real health risk. A mild sewage-like odor or the smell of rotten eggs in your shower water is often caused by low levels of bacteria, sulfur compounds, or hydrogen sulfide, and it’s generally safe for bathing. That said, the smell can be really off-putting, and if it’s strong, persistent, or accompanied by cloudy or discolored water, it’s a good idea to test your water or call a professional. In many cases, the odor comes from your drains or water heater rather than the water supply itself. Simple fixes like cleaning drains, flushing the heater, or checking your plumbing can often make your showers smell fresh again while keeping your home water safe and pleasant to use.