Why does my home smell like a sewer after it rains?

Why does my home smell like a sewer after it rains?

Have you ever wondered why your home sometimes has a foul sewer stench especially after light or heavy rainfall? The truth is, there are many known factors that are causing your home to emit this very distinctive odor. You could have a broken pipe in your sewer line which can compromise your plumbing system. Let's focus on the known and unknown causes of how your home develops that pungent odor, the dangers of having a sewer gas leak, what you can do to help prevent that sewer smell from returning, and when it's time to tag in the professionals to rid your home of that sewage smell once and for all.


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Pointing out the Obvious and Not so Obvious Reasons Your House Smells Like a Sewer

The reason your house is emitting a foul odor can be because of something as simple as decomposing waste or food scraps lingering in the garbage disposal, both of which are causing a major clog in your drain pipe. However, it is most likely due to one or more and possibly a combination of all of bacteria and decomposing waste, a full septic tank, a dried out water barrier and even the imbalance between the water and pressure.

The Bacteria Breakdown of Waste

The leading and most frequent causes that your house smells like a sewer when it rains is largely due in part to the bacteria that decomposes the waste in the sewer system. Though there are other infinitesimal (extremely small) organisms like: fungi, protozoa and actinomycetes, that play a role in the breakdown of waste, it is bacteria microbes that feed off of the organic waste, doing the brunt of the work in the decomposition process.

Most sewers consist of everything you flush down the toilet and wash down the drain but is mostly a combination of water, human waste and non-biodegradable materials like: plastic, condoms and sanitary towels (baby, makeup remover, cleaning wipes) is what gives your house that sewer smell as the bacteria takes longer to breakdown these materials.

Your Septic Tank May Also Be to Blame

Naturally, rain causes a shift in the atmospheric pressure, meaning that the air outside can become very heavy. As a result, the methane gas inside most septic tanks cannot flow through the vent as it should. Alternately, the air remains low to the ground thus causing a very bad smell, very much the same to that of rotten eggs. Colder climate conditions like the winter season has been known to cause downdrafts (a downward current of air), so you may also notice that the foul odor varies during the day especially with severe winds while the temperature rises.

The size of your septic tank always depends on the size of your house and how many people will actually be residing in the home but the standard size for residential septic systems can range anywhere between 750 gallons- 1,250 gallons. When your septic tank has reached it's maximum intake, it often causes the pump to breakdown, preventing the new wastewater to take the place of the old wastewater bringing forth... you guessed it, those terribly bad smells. The leaks from even a nearby septic system can enter your home through cracks in your home's foundation.

When the venting system of your septic tank is blocked, this may be yet another possible reason why your house smells like a sewer. It normally occurs when you have home renovations and major landscaping work done on your property that cause the vents to stop functioning. When this happens, it means that the sewage gases are unable to escape from the wastewater, accumulating in your house and causing that sewer smell.

Your Water Barrier is Dry as a Bone

If your house smells like a sewer when it rains, another possible culprit may be a dried out water barrier. A water barrier is standing water that remains in the sewer traps of your drain pipes. This standing water serves as a barrier through which no sewer gas can infiltrate. There should always be standing water in the sewer traps as it impedes any toxic gases like sewer gas that is contained in wastewater, your septic tank and the public sewer line from escaping and entering your home.

Typically, a dried out water barrier happens over time because of the lack of use. If you have any pipe fixtures in your home you seldom use like: a toilet or shower in the basement, the water barrier inside the sewer trap can dry out.

Sewer traps come in many different shapes and sizes and each drain line in your home is attached to their own sewer trap. They can not only prevent clogs but they also allow for the cleaning of clogs.

How The Water and Pressure Play a Supporting Role

Here's why your house smells like a sewer even on the outside. When there is a rainstorm, the rainwater has to go somewhere when it falls. Gravity forces the rain to go to the lowest point possible so it pours into any accessible gutter.

The problem is that, when the water accumulates, it naturally takes up space causing the gas, also inside to move up to make room for the rising water volume. In fact, it is simple science. The gas fumes are not as dense as water, so as the water goes down, it forces the gas fumes to rise up, coming out of the sewer and there you have it, that terrible sewer smell outside your home.

The More Minor But Common Causes of The Sewer Odor in your Home

1. Cracked Pipes

Rusty broken and cracked pipes are not strong enough to keep the gas from getting out which allows them to come into your home.

2. Leaks

When your homes pipes and vents are not installed correctly, it can eventually lead to to leaks in your plumbing. In other words, another way for sewer gas to escape into the walls inside your home.

3. Clogged Drains

The drains in our homes main duty and responsibility is to transfer toxic waste through the septic system. As you may have read in our last post: How To Unclog a Drain, the most common cause of clogged drains is sewage backup. This type of clog is almost always caused by non-flushable objects and items. (Items that should not be poured or flushed down the drain). Naturally, if left untreated, these non-flushable items, progress into the process of decomposition thus producing that ghastly sewer smell in your home.

4. Loose Toilets

As mentioned above, every pipe has its own sewer trap and in the case of most residential toilets, they have a U-shaped sewer trap. When and if the trap is not sealed off with the proper sewer plugs or if the sewer plugs have loosened, this is where the sewer gas gets its chance to break free and emerge into your home. The release of these volatile organic compounds (off-gassing) can in fact be lethal, hence the very purpose sewer systems are designed with sewer traps- to halt the escape of gas.

The Dangers Of A Sewer Gas Leak

Is sewer gas dangerous? Yes — breathing sewer gas can be extremely harmful to your health. Sewer gases are a combination of various fumes and compounds, including ammonia, carbon dioxide, hydrogen sulfide and methane.

Some of the very first warning signs that your home may have a sewer gas leak is rotten eggs foul smell. Some of the more minor symptoms you may experience are: lightheadedness, dizziness, headaches, nausea and or vomiting, fatigue, poor memory and even poor concentration.

Though both carbon dioxide and methane are non-toxic and relatively harmless to humans, they are extremely flammable and in larger amounts can be labeled as a major fire hazard.

There is a reason, we recommend you wear gloves and even a mask when cleaning as this is due largely in part to the high cotenants of ammonia in your everyday cleaning agents. Even only low level exposure to ammonia can still cause irritation to the eyes, nose and throat, making it hard to breath. When and if exposed to ammonia and or hydrogen sulfide at higher levels, it can cause you and your family to lose your sense of smell, develop pink eye, have seizures, cause extensive organ damage, fall into a coma and even lead to your death.

If your house smells like sewer, has a foul smell like rotten eggs and especially if you smell sewer gas in your home, you need to take action immediately to reduce the risks of you and your family developing long-term health issues.

What Can You Do to Prevent that Awful Sewer Smell in Your Home?

Why It's Important That Water Stays in the Sewer Traps

Once you know the location of each and every sewer trap, but especially the ones that are rarely used or not used at all, a good way to slow down the evaporation process and keep it from drying out is to pour a few tablespoons of vegetable oil on top of the water in the sewer trap. This helps the water stay at the correct levels, preventing the gas from rising up and causing that sewer odor in your home.

Always Ensure Your Toilet is Properly Secured

It is important to have your toilets checked for any loose joints or bolts to ensure that there is no way for the sewer odor to escape and accumulate in your home.

Don't forget About Cleaning Your Drains

It is extremely important to routinely clean your drains to make sure they are clear from any clogs. The most common things that caused your drains to get clogged are hair, debris, foreign objects and much more. Just in case you missed it, there is a way to learn how to unclog like a pro. Here's everything you need to know about how to Unclog any Drain at Home.

When Should You Seek the Assistance of a Professional Plumber

As previously forewarned, when sewer gasses form, it is a potential hazard so it is critical that you call a professional, licensed specialist plumbing company as soon as you suspect that you may have a sewer gas leak. Even if you fancy yourself an advanced DIYer that has dealt with sewer gas odor, you really shouldn't attempt to fix the sewer smell on your own.

Located in Connecticut, All Things Sewer & Drain Care offers a range of expert plumbing services, using tools designed specifically to inspect a sewer trap, your septic tank, the sewage system in the main sewer line to identify the exact sewer gases that are causing your house to smell like a sewer when it rains. They'll make sure your home will never smell bad again by making sure your sewer trap plugs and leaky toilet is properly secured so you can breath easy even on a rainy day.