Sewage Backup In Basement Health Risks

Sewage Backup In Basement Health Risks

Sewage Backup In Basement Health Risks

sewage backup in basement health risks

Presence of the Chinese virus in wastewater (1)

Sewage back ups are among one of the worst plumbing problems because of the risk that they present to homeowners and residents. Sewage can spread illness, disease and even death. The National Resources Defense Council reports that nearly 2 million cases of illnesses are caused by sewage contamination each year. Sewage is full of contaminants, viruses and bacteria that pose a serious threat to people and their pets. In addition, sewage may contain other toxic substances like pesticides, residuals from pharmaceutical drugs, fungi and protozoan.

Sewage backing up into a home or office can happen to anyone at any time. Many things can cause a sewage backup, from a pipe clogging to a flood overfilling a local sewer system. A sewage loss can seem like a relatively easy cleanup to tackle alone, but it should not be handled by anyone other than specialists. Below we discuss what dangers sewage can pose if not handled with extreme care.

A sewer line clog causes extensive damage to your home and health especially if it creates sewage backup. While it may be unseen, let’s review the symptoms of sewage backup and save you significant time and money. Sewage backup, after all, contains toxic waste capable of thousands of dollars in damage to your home.


Sewage carries toxic viruses and bacteria. Likewise, it can carry toxic substances like pesticides, fungi, and protozoans. There are more than two million sewage-related illnesses each year. Contaminants in sewage water are harmful and even toxic to humans and animals. Therefore, deal with sewer clogs immediately.

Diseases Caused by Raw Sewage Exposure

  • Campylobacteriosis: Symptoms of this disease include fever, bloody diarrhea, abdominal pain, cramping, nausea, and vomiting.  this bug commonly found in animal faeces, is one of the most common causes of gastroenteritis. Government figures indicate that it is responsible for more than 280,000 cases of food poisoning each year, and 100 deaths. Most of these will be caused by poor food hygiene in the home or in restaurants. However campylobacter is also found in sewage, so coming into contact with raw sewage from a sewage spill could result in a potentially deadly infection.
  • Cryptosporidiosis: This waterborne disease causes a slight fever, diarrhea, loose or watery stools, upset stomach, and stomach cramps. Cryptosporidium can cause diarrhoea in healthy people but can be fatal for people who are already frail or unwell. It is a particular risk for people with immune deficiencies.
  • Diarrheagenic E. coli: Drinking fecal-contaminated water can expose you to E. coli, resulting in fever, watery or bloody diarrhea, abdominal cramps, nausea, and vomiting. A bacterium commonly found in the lower intestine, so also found in sewage. It is also closely linked with food poisoning, through food being prepared in unhygienic conditions, or with contaminated water. In 2000, an inquest hears that an eight-year-old girl who died of E coli poisoning could have caught the infection from sewage discharged into the sea near the beach where she played.
  • Gastroenteritis: Also known as the stomach flu, this infection causes fever, watery diarrhea, headaches, abdominal cramps, and vomiting.
  • Leptospirosis – causes vomiting and muscle soreness
  • Giardiasis: The Giardia parasite spreads this disease, causing diarrhea, loose or watery stools, upset stomach, and stomach cramps.
  • Hepatitis A: This viral liver disease is contracted from ingesting infected fecal matter. Symptoms include fever, fatigue, jaundice, abdominal pain, loss of appetite, nausea, and diarrhea.
  • Salmonellosis: Caused by exposure to Salmonella, this disease can cause fever, diarrhea, and abdominal cramps. A gram-negative and hardy bacterium, which can survive outside a host, making it one of the most dangerous types of bacteria in raw sewage. Salmonella can cause gastroenteritis, typhoid fever and paratyphoid fever, all potential killers.
  • Dysentery: Ingesting contaminated fecal water can cause this disease, symptoms of which include fever, bloody diarrhea, and stomach cramps.
  • Chinese virus: There was a worldwide pandemic of this virus from 2020 to 2022. Now it looks far away, but the virus of this acute respiratory syndrome was detected in wastewater too.
  • Typhoid fever: A bacterial disease spread through contaminated food and water, this disease causes high fever, weakness, cough, headaches, stomach pains, and loss of appetite. Some people also experience a rash.
  • Listeria Bacteria: It is common in nature, including sewage, and can cause a potentially deadly infection called listeriosis. Most infections in healthy adults cause only mild symptoms. However, elderly people, and those with weak immune systems, such as people with cancer and AIDS, may suffer severe potentially fatal illness, including meningitis and septicaemia. Unborn children can suffer a particularly deadly condition as a result of listeria poisoning, called meningoencephalitis, which has a 50% death rate.
  • Adenovirus: This virus is quite commonly found in sewage. It causes respiratory infections like pneumonia, croup and bronchitis. It is also known tocause eye infections, such as conjunctivitis, which can be severe. Deaths are rare. But Adenovirus is the second most common cause of severe respiratory illness in children, and can be fatal, especially for babies under the age of six months.
  • Norovirus: Known as the winter vomiting bug, and also called the Norwalk virus, this is one of the most common causes of gastroenteritis around the world. The virus is present in sewage. For example, oyster farmers in Cornwall (UK) warn that norovirus has been found in oysters living in seawater contaminated with sewage, and that food poisoning caused by eating oysters contaminated by norovirus in this way is common. Elderly people are particularly at risk from norovirus.
  • Rotavirus Another potentially fatal virus found in raw sewage. It is the most common cause of diarrhoea in small children. In developing countries, it is a major killer. The World Health Organization estimated that, globally, 453 000 child deaths occurred during 2008 due to rotavirus infection.
  • Asphyxiation: Sewage generals a number of harmful gases, known collectively as sewer gas. Gases include methane, ammonia, hydrogen sulphide, carbon monoxide, sulphur dioxide and nitrogen oxides. This can have deadly consequences, especially for people who work on sewers or sewage treatment plants or who have septic tanks. In 2014, seven family members on a pig farm in Poland died when they were all overcome by noxious gas from their septic tank. The mother had fallen into the tank when she drove a tractor onto its cover and it gave way. The rest of the victims had tried to rescue her.
  • Drowning: Sewage is commonly a liquid, so sadly there are regular cases of people drowning in it. In one unusual case, a women in London is thought to have walked into a large sewer in an agitated state then crawled for eight miles through the pipes before falling into water and drowning. In some cases, hydrogen sulphide gas has created acid, which has corroded septic tank covers, making them weak, resulting in people falling through them and drowning in the sewage below.
  • Heliobacter Pylori – causes increased risk of developing ulcers
Sewage Water Contains Diseases and Bacteria

To begin, we explain exactly what sewage is. Primarily, sewage is contaminated water containing waste of any type. Sewage can be a mixture of waste from both household and industrial sources. The waste can contain anything as harmless as soap to more harmful things such as human or industrial waste. Sharing the same space as sewage, for any duration of time, often means coming in contact with many harmful bacteria and diseases.

One of the more dangerous bacteria you can come in contact with in sewage backup is E. coli, also known as Escherichia coli. Normally found within the digressive tracts of humans and harmless when in that system, E. coli is extremely harmful outside of the intestines. According to the CDC, E. coli is one of the most common contaminants found in sewage. Coming into contact with E. coli can lead to cramping, vomiting, severe diarrhea, and dehydration.

By being in contact with sewage you could also be exposed to the hepatitis A virus. Hepatitis A is an infection that is not only highly contagious but also directly affects your liver. The typical symptoms of hepatitis A are jaundice, or yellowing of the skin, and an inflamed liver.

Sewage contamination should be considered extremely dangerous. It has the ability to make not only whomever comes into direct contact with it very sick, but also anyone else with whom the exposed comes into contact, as there are many highly contagious bacteria and viruses commonly found in sewage.


Pathogenic organisms – or pathogens – are microorganisms that can cause illness in humans. While the bacteria that inhabit the human gut are non-pathogenic in the gut, they can be pathogenic if they are ingested again once they have left the body. Sewage leaks release these organisms, where casual contact can cause the pathogens to come into contact with food. Moreover, raw sewage is an ideal medium for many pathogenic organisms that grow outside the body. Botulism – a powerful toxin – is produced by the bacteria Clostridium botulinum, which can be produced in raw sewage where there is little oxygen. E-coli, salmonella, campylobacter, intestinal amoebas, shigella and even cholera are included in the list of pathogens that can be carried in raw sewage.

The diseases and bacteria found in sewage may seem avoidable, but this is often not the case. A common misconception regarding sewage is that you can only get sick from directly consuming the substance. However, many of the diseases and bacteria found in sewage backup can be transmitted in many ways outside of direct consumption.

One of the most common ways for bacteria from sewage backup to enter your body is through hand-to-mouth contact. Coming in contact with bacteria can be as easy as not properly cleaning your hands after touching sewage and then eating or drinking. Many may think of cleaning their hands before eating or drinking, but smoking a cigarette or cigar when your hands are not properly cleaned is also an extremely easy way to be infected by bacteria and diseases.

The second most common way to be infected by bacteria is through skin contact. This could be forgetting about a cut on your leg and exposing that cut to sewage. A disease present in sewage may even spread quicker when given an easy entry to your body such as an unhealed cut. No matter how careful you may be when cleaning, you run the risk of infection when cleaning sewage yourself.

Bacteria In The Septic System

Bacteria are important to break down sewage as part of the cycle of treatment that will make the water safe for reintroduction into aquifers and waterways. That is the purpose of most underground septic tanks – to allow bacteria to work on the sewage before it is sent forward to a drainfield, or leechfield, where it can percolate through the subsoil’s natural filters and back into the water table. Some people think bacteria needs to be added to sewage from the house to ensure the septic tank works properly, and they add yeast or other bacteria-producing materials to flushed water. This is unnecessary, and it could cause pathogens to occur in sewage before it leaves the house, which would be released in the event of a leak.

Sewage Causes Air-Borne Contamination

Not only is coming into physical contact with raw sewage a threat, but sewage can also contaminate the air around you. Sewage backup lets off air-borne contaminants along with the physical contaminants. Inhaling the vapors emitted by raw sewage can lead to gastroenteritis, which is commonly associated with fever, vomiting, cramping, and potentially death if left untreated.

Sewer gas is very important when we describe the sewage backup in basement health risks, because it is easy to become exposed to it, and less noticeable than the presence of blackwater.

Sewer gas is the smell coming out from sewage. The sewer smell contains hydrogen sulfide gas. This gas is the outcome of bacterial breakdown of organic matter, and human waste.

A low-level of exposure from sewage gas could cause a sore throat, eye irritation, cough, and shortness of breath. If you’re exposed to this low-level of sewage gas for prolonged periods it could cause fatigue, loss of appetite, headaches, irritability, and even poor memory.

If the cleanup in your home is taking longer than expected, the best thing for your health would be to get a hotel or find another place to stay for the time being.

The most immediate danger from a residential sewage leak is gas. Sewage can generate a variety of gases, including carbon dioxide, methane, chlorine, nitrous oxide, hydrogen sulfide and sulfur dioxide. Any of these gases can cause people and animals in the house to suffer from a lack of oxygen, which can cause disorientation. The most common gas hazards from sewage leaks are hydrogen sulfide and methane. Hydrogen sulfide is toxic, and can cause sickness, disorientation and even death in high doses. Methane can asphyxiate occupants of the house, acting quickly even in small amounts to produce unconsciousness and death.

A more common health concern associated with air-borne contamination caused by sewage is asthma. As sewage can release toxins or even infected dust, the risk for breathing in the toxins is very high. Once inhaled, the toxins can attack your upper respiratory system, causing asthma-like symptoms and shortness of breath. These fumes are often released into the air during the cleaning process, which is why it is especially important to hire a specialist and professional.

Chemicals Utilized In The Septic System

One way to disrupt the septic system’s production of beneficial bacteria is to flush chemicals down the drains and toilets. Cleaning products, paints and thinners, and pesticides can kill beneficial bacteria. The other problem with these products is that they can actually cause leaks, and the leaks can then expose your family to these chemicals. Many of these chemicals are corrosive. They damage pipes, break down pipe joints and promote oxidation. If this damage results in a leak, then these same chemicals are released into the house.

A sewage loss can be an exceptionally dangerous situation. Due to the sensitive nature of cleaning up a sewage loss, it is a much safer choice to leave the cleanup and restoration to the professionals.

Sewage Backup In Basement Health Risks Can Be Reduced

Prevention is the key. Follow these steps to reduce your risk:

  1. Wash your hands after every contact with the flooded area, after using the toilet, and before eating.
    • Wash hands under warm running water.
    • Use liquid soap.
    • Lather hands for at least 20 seconds.
    • Dry hands with a paper towel.
  2. Follow appropriate sanitizing procedures.
    • Put 8 tablespoons of laundry bleach (i.e., Clorox, Roman Cleanser) in each gallon of water used to sanitize contaminated areas and objects.
    • Discard cloth items that cannot be laundered, like stuffed animal toys or pillows.
    • Open windows and use fans to ventilate the contaminated area.
    • Keep pets out of the flooded area to prevent them from tracking sewage to other areas.
  3. Dispose of trash, including objects like toys and clothing, in leak proof bags and label as contaminated with sewage. Large items that cannot be bagged, such as furniture or carpet, should also be labeled as contaminated with sewage. Warning labels, attached to trash that is placed at the curb for pickup, will help prevent other people from salvaging these items.

Causes Of Sewer Backups

If the sewer back is from the yard, then tree roots or breaks in pipes could be the culprit. If the sewer backup is inside your home, it could occur because of improper flushing etiquette.

Wipes or any other similar thing can lead to blockage inside the pipes, which can eventually lead to pipes burst. If you notice that the drainer on a sink or tub isn’t working properly, then it could be a sign that you need to keep better track of things you’re flushing down the drain.

You could hire a plumber to take a look at your pipes in case you’re worried about their well-being. But you could also do it yourself if you’re tech-savvy enough. All you have to do is rent a drain auger with a camera attachment and take a look at it yourself. It’ll save you money.

According to the Civil Engineering Research Foundation, the number of sewage backup incidents is increasing at a rate of about three percent. This is considered an alarming number by experts in this field. While not all basement flood damage is due to sewage backup, there are some main culprits. These include:

Why Do Drains and Sewage Back Up?

Only a professional plumber can pinpoint the cause of your sewage backup problem. Some of the most common reasons include:


As they seek moisture and nutrients from organic material, tree roots wiggle into service pipe joints and cracks. These tree roots in the sewer line quickly grow into a major clog and sometimes, destroy the pipe. If you have (or your neighbor has) mature trees or those with invasive root systems, watch out for this problem. Usually, a camera inspection is the first step to verify if tree roots in the sewer line are the source of the problem. The tree’s owner is commonly responsible for the cost of clean up and repair.


Some municipalities combine stormwater and raw sewage pipelines. During heavy rainfall, the volume exceeds the pipe system’s capacity. As a result sewage backup flows into basements and other low-lying drains.


Occasionally, there’s a blockage in the city’s sanitary main. Typically, the symptoms present slowly over time. If you suspect seepage around your basement’s floor drain, for example, request a licensed plumber from A.B. May to assess the problem and any damage. If, however, sewage water enters your home rapidly, report the problem immediately to your public works office.


In a study performed by the American Society of Civil Engineers, (ASCE) they rated the wastewater systems in the U.S. with a D+ and drinking water a D. Why? There are more than 800,000 miles of public sewage pipes in the U.S. and the majority of water mains and pipes were laid in the early to mid-1900s. With a projected lifespan of 75 to 100 years, several are already crumbling.

Keeping Pipes Clean

Moving ahead, be sure not to dump any more greases, wipes, contacts, cotton swabs, floss, or even paper towels down the drain. It may lead to a blockage inside the pipes. Keeping your pipes clean will help you avoid the sewage backup problem. This’ll save you money in two ways.

In one way, you won’t have to worry about making a call to a plumber or clean up crew which could cost a couple thousand depending on how bad it could be.

The other way it could save you money is by keeping you away from the hospital. Both bills on top of each other won’t do your wallet any favors. 

Other related causes include:

  • Structural defects.
  • Root infiltration.
  • Improper flushes (items that shouldn’t be flushed down the toilet).
  • Wet weather.
  • Flooding around and under your home.
  • Planning problems with sewage lines.
  • Pipe blockages.
  • Broken or leaking pipes.

Sewage Backup Symptoms


If you notice water bubbling from other drains, this is a clear sign something is wrong with your sewer line. Are you running the washing machine and hear a gurgling in the kitchen sink? Do you notice water in the basement after you take a shower? Take note of these symptoms and call a licensed plumber to take care of the problem. 


Stenches are also a clear sign something is wrong, especially if the smells linger. Odors indicate sewage isn’t draining properly, and could potentially be coming in through your drains, which is a major health hazard. 


Does water take a while to drain after a shower or a bath? Do you notice sitting water around drains? If so, a sewer line clog is a likely cause.

Sewer Backup Property Damage

You may also experience property damage because of a sewer backup. It is very likely that your pipes will be damaged and you will need a sewer repair. If the sewage water remains in your home for an extended period, you may experience even more damage to your property. This can include the traditional signs of water damage on your walls and floors, as well as insulation and flooring materials that are rendered entirely unusable.

A more pressing issue can be the uninhibited growth of mold and bacteria. Left untreated, mold and bacteria can grow, and reach multiple floors in your home.  If the problem is extreme, walls and other articles have to be completely demolished and replaced.

Any other personal possessions that have been soaked will not be salvageable either, like mattresses, leather furniture, paper products, and stuffed toys. Washable fabrics and furniture that can be deep-cleaned can be retained, but that is expensive. Every other object you decide to keep will need to be disinfected with chlorine bleach, rinsed thoroughly, and dried.

Sewer Backup Fire Hazards

Fire hazards are also a common sewer backup risk. If the water level has risen to the height of any electrical outlets, plugs, extension cords, or gas-burning equipment, refrain from touching anything and get out of the building as soon as possible. Call a professional to handle this problem, as the risk of starting a fire is tremendous.

If your electrical equipment is still above the water level, turn off your power when you first notice the issue. Safety should always be your number one priority. Make sure you are wearing rubber boots, standing on a dry surface and not touching any metal objects like ladders and pipes.

What to Do After a Sewer Backup

The very first thing you should do when you notice sewage leaking into your home is to call a reputable drain cleaner. If there is structural problems with your drain system, then you’ll need a sewer repair company. It is crucial that you handle this problem quickly to minimize the risks to your health and your home. Let a professional handle the sewage leak; you worry about staying safe, healthy, and protecting your property. Avoid coming into contact with sewage in any way, even inhalation. If you need to cross a sewage spill to leave your home, wear rubber-soled shoes and put on a breathing mask. Then remove any shoes and clothing that came into contact with the sewage.

If you’re cleaning the sewage spill by yourself then you’ll need equipment to stay safe and sickness free. As mentioned before, you may get in contact with several diseases and parasites from working to clean up the sewage.

If you have any open wounds, be sure to cover them with waterproof bandages. Heavy-duty gloves will also help when you’re moving piles of mush.

It’ll help you cover your hands in sewage as well as preventing any injuries. A gas mask will add further protection to filter the sewage gas. If you want to go the extra mile, then you can cover yourself from the plastic suit.

Sewage Remediation Costs

The cost of cleaning up sewage in the crawl space averages between $10 and $25 per square foot. You can also expect these factors to affect the final cost.

  • Difficulty of access to contaminated spaces
  • Length of time between initial spill and cleanup
  • Extent of repairs needed for broken sewer pipes and drain lines
  • Mold removal, remediation and restoration services
  • Any necessary structural tear-out and reconstruction

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BY M. Kogan

Hello, I am Marcio. I am an architect and designer, alma mater is Mackenzie. Retired in theory, but an architect never retires completely. Along with architectural projects, I am a filmmaker and have completed some short documentaries. Filmmaking and design are my passions. In HomeQN I write about home decoration and foundations. The goal is to teach homeowners to DYI as much as possible, and when this is not possible, enable them through knowledge, to evaluate service quotations and choose the best service technicians.

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