Yes. If there is no regular septic tank cleaning or pump-out, the tank will release toxic gases and leak wastewater into the ground.

Even at low concentrations, hazardous gases like methane and hydrogen sulfide can cause abnormalities in your skin, lungs, and eyes. When wastewater leaks into the ground, it could also contaminate your well water. Bacteria, parasites, and viruses are very likely to enter your home.

Although the health risks are much less in the early days, in the long run low exposure can lead to issues, especially a household with children, elderly, or respiratory patients.

How a Dirty Septic Tank Can Affect Health

When tanks sit buried underground, they don't sit in place like forgotten rubbish, they can seep pollutants, leak into the ground, and emit those conditions into your home.

It starts to release sewer gases

Sewer gases consist of a mixture of carbon dioxide, methane, ammonia, and hydrogen sulfide. The gases can be toxic in nature or are flammable. If the septic tank doesn't tend to its purpose, as the waste breaks down it releases pollutants - gases such as methane and hydrogen sulfide. 

Hydrogen sulfide exposure even at low doses below 10 ppm has been implicated in eye, nose, and respiratory irritation, headaches, and fatigue.

Repeated exposure to as few as 1 ppb can contribute to neurologic effects, particularly in individuals with asthma or sinusitis.

Sewer workers commonly have sore throat, cough, tight chest, and irritability. One survey reported 54% of sewer workers with repeated exposures to hydrogen sulfide had these sub-acute symptoms.

Worst still, severe gas leaks have caused acute poisoning, such as unconsciousness, lung injury. This indicates it's a lot more than just a pest.

It starts to contaminate groundwater 

Dirty septic systems can also leak bacteria-rich wastewater into soil or groundwater. That water carries pathogens like E. coli, viruses, and parasites. 

If these contaminate well water or surface water, they can cause stomach illness, diarrhea, skin infections, and even serious diseases

Bacteria such as Pseudomonas aeruginosa and Aeromonas hydrophila are common causes of water-based skin infections. They can result in quick onset wound infections, developing in as little as 8–24 hours after exposure. These infections can lead to deep tissue complications if not treated.

• If you have standing water or damp dirt alongside your septic drain field, there's an honest likelihood it's contaminated.
• Bare skin contact with this water, particularly if you have even the slightest scratch can result in infections.
• Children playing outside and gardening in bare feet are even more susceptible to it.

Will it cause you severe health issues? 

Severe home septic tank disease is not common, especially if the septic tank model is well maintained and you are not directly exposed to leaks or standing wastewater. Home health effects are typically minor and due to exposure to small concentrations of gas or contact with contaminated water.

But sometimes, especially with prolonged exposure to leaking sewage, the nausea, dizziness, or inexplicable exhaustion symptoms may present. If you have them without obvious reason, and your septic tank model is known to have an issue, don't underestimate it.

Greater risks are incurred where ventilation is poor, confined septic arrangements, or industrial areas where tanks receive larger quantities or mixed waste. Even in the home, however, neglecting indicators such as offensive smells, wet soil, or sluggish drains means minor exposures accumulate over the years.

How to Prevent Health Risks  

Well, if you get leaks now, you can do anything, just call the plumbers. Let them do it for you.

Here is a quick thing to remember, to avoid it from happening next time:

1. Regular Inspections and Pumping

Inspecting your septic tank every 1–3 years and pumping it every 3–5 years keeps waste from building up and spilling into your yard or groundwater

• A full tank loses its ability to separate solids from liquids. That leads to leaks, backups, and harmful overflow.
• In a 2024 EPA inspection report from Ireland, over half the systems failed, putting water supplies and health at real risk.

2. Keep Harmful Items Out of the System

• Avoid flushing wipes, grease, diapers, sanitary products, paint, pesticides, and chemical cleaners. These clog the tank or kill the helpful bacteria that break down waste.
• When microbes die, solids build up faster, raising failure risk.

3. Reduce Water Overload

• Excessive water entering at one time upsets breakdown and compels solids to enter the drain field.
• Use low-flow fixtures, repair leaks, space showers, and load dishwashers completely to avoid stressing them

4. Protect the Drain Field

Don't drive or park on it, plant deep-rooting plants, or compact soil

• Tiny disturbances can clog effluent from seeping into the ground.
• Watch for soggy spots, these may be ground seepage and could become contaminated.

5. Test Well Water Annually

If you have a private well, test annually for nitrates and bacteria such as E. coli if your septic tank is close by

A CDC-associated study discovered that in groundwater-linked outbreaks, 67% were followed back to septic systems

6. Avoid Additives and Unnecessary Chemicals

Septic "treatment" additives, i.e., yeasts or enzymes are not necessary and can kill tank bacteria. Heavy metals, solvents, and bleach contaminate groundwater and throw off system balance

Conclusion 

A dirty septic tank can expose you to harmful gases and waterborne pathogens, especially when it's left unchecked for too long. This may be avoided with routine maintenance and inspections.

Adding a bio-based cleaner like Bioclean septic tank powder supports the natural bacteria that keep your system balanced, reducing the risk of leaks, odour, and contamination. It’s a simple step that helps protect your health and your home.

FAQs

1. Can a dirty septic tank make you sick?

Answer: Yes, a dirty or poorly maintained septic tank can pose health risks. When a septic tank is not regularly cleaned, waste accumulates and can overflow or leak into the surrounding environment. This can lead to exposure to harmful bacteria, viruses, and pathogens found in untreated wastewater, which can cause diseases like gastroenteritis, E. coli infections, and other waterborne illnesses.

2. What are the health risks associated with a dirty septic tank?

Answer: A dirty septic tank increases the risk of contamination from harmful bacteria and pathogens. When wastewater leaks into the ground or your home, it can contaminate drinking water sources, gardens, or even flood areas where people walk or play. This can lead to infections, stomach problems, skin rashes, or other illnesses from bacteria such as Salmonella, E. coli, or Hepatitis A.

3. How does improper septic tank maintenance affect my health?

Answer: Improper maintenance, such as not pumping the septic tank regularly, can lead to backups or overflows. These issues expose you and your family to harmful waste materials that may contain harmful microorganisms. Additionally, a failed septic system can pollute local water supplies, increasing the risk of diseases transmitted through contaminated water.

4. Can I get sick if the septic tank overflows in my yard?

Answer: Yes, if a septic tank overflows, the wastewater can spill into your yard, releasing harmful bacteria and pathogens. This exposure can lead to skin infections or more serious illnesses if the contaminated water is touched or ingested. It is essential to stay away from areas near septic tank overflows and ensure proper maintenance to avoid such situations.

5. How can I prevent health issues caused by a dirty septic tank?

Answer: To prevent health issues, make sure to maintain your septic system regularly by having it inspected and pumped every 3-5 years, depending on usage. Avoid flushing non-biodegradable materials, such as chemicals, grease, and wipes, that could clog the system. Properly sealing your septic tank and ensuring it’s free from cracks will also help prevent contamination and reduce health risks.