Signs that indicate a septic tank problem

8 Signs of a Failing Septic Tank: How to Detect and Solve the Problem

Septic tanks are essential for managing residential wastewater. These underground chambers made of plastic, fiberglass, or concrete are responsible for basic treatment of household sewage. A properly functioning septic tank ensures that the wastewater is stored and treated safely, without causing any health hazards. However, when a septic unit malfunctions, it can cause significant plumbing problems, and become a serious threat to public health.

As a Septic Tank Engineer, I can tell you that there are certain tell-tale signs of a failing septic tank. If you suspect that your septic system is not functioning properly, you should take immediate action to prevent any potential health hazards. In this article, I will discuss eight signs of a septic tank problem and provide tips on how to fix them.

Septic System Backup

The most obvious sign of septic tank failure is a backup of sewage and wastewater. When your septic system fails or is full, the sewage and wastewater will no longer enter the tank, but instead, stay in the pipes until it starts to come up. This results in sewage and wastewater backing up into sinks, drains, and even your toilet. If you notice this symptom, contact a licensed plumber immediately for service.

Slow Drains

Septic tank failure can also cause slow drains. When the septic tank is full, it won't actively collect wastewater, leading to sewage clogging your pipes, thereby inhibiting your plumbing appliances' ability to drain. No matter what tools you use to unclog your drain, you won't succeed since the underlying problem lies in the septic tank. Slow drains are the precursor to a full septic system backup, in which your drains don't work at all, and wastewater backs up into your home.

Gurgling Sound

Another sign of septic tank failure is hearing strange sounds when you use plumbing appliances. If you flush your toilet and hear weird gurgling sounds, then you should contact a plumber immediately. The same principle is true if you hear gurgling noises in your drains. Gurgling noises point to a clog or an internal septic system issue that requires immediate servicing.

Pool of Water or Dampness Near Drainfield

When a septic tank fails, it will no longer absorb wastewater. As a result, wastewater will naturally seep from the ground, forming a large pool of wastewater near the drain field or lead to dampness in the same region. These are the most glaring signs of septic system failure, which will look like it has rained on your lawn for a very long time. Dampness near your drain field, especially when it hasn't rained for days, is also suspect.

ducks on a flooded field

ducks on a flooded field from septic tank 

Nasty Odors

5.One of the most noticeable signs of septic system failure is the presence of nasty odors near the drain field and plumbing appliances. If you detect strong and foul odors when you walk outside and step into your lawn, then your septic tank likely has failed. These nasty odors point to the presence of sewage that has crested the drain field and worked its way into your main drain line.

Unusual, Bright Green Grass Above Drainfield

6.If you notice unusually green grass near your drain field, it is likely that wastewater is leaking into your lawn. Sewage contains nitrogen, potassium, phosphorus, and micronutrients that plants can absorb to grow, and so wastewater has the same properties as manure. Wastewater will contribute to abnormal levels of greenness in your grass to an extent in which you'll definitely notice. Pay close attention to your drain field to spot this issue before it becomes too problematic.

Blooms of Algae in Nearby Water

7.If you live near a water source such as a nearby lake or pond, then watch out for sudden algal blooms. While most people consider the presence of algae to be a normality, algal blooms happen when a large proportion of algae forms in a pool of water. These blooms are unnatural and look like the water has been overly contaminated with algae. The presence of wastewater can contribute to the abnormal growth of algae, which can harm aquatic life and even lead to public health concerns.

High Levels of Coliform in Water Well

8.If you have a nearby water well, you can also detect abnormal levels of coliform bacteria and nitrates. A water well is naturally free from bacteria and harsh chemicals, but septic system failure will result in contamination from nearby wastewater. The presence of coliform bacteria and nitrates in your water well can cause serious health problems, especially for vulnerable populations such as children, elderly, and people with weakened immune systems.


A septic tank problem is not something you can ignore or put off until later. The signs of a septic system failure can be subtle or glaring, but it's crucial to spot them before they become a major health hazard. If you suspect that your septic system is not functioning properly, call a licensed plumber right away to have it inspected and fixed.

To avoid septic system failure, it's essential to follow proper maintenance practices such as regular cleaning, proper disposal of waste, and avoiding flushing non-degradable materials such as wipes and sanitary products. Proper maintenance will not only extend the life of your septic system but also ensure that it operates efficiently and safely.

In conclusion, detecting and fixing septic tank problems is critical to protecting your home and the surrounding environment. By recognizing the eight signs of septic tank problems and taking immediate action, you can ensure the health and safety of your family and community