Are Septic Tanks Bad?

In theory, a well-designed and maintained septic tank causes no pollution.  In practice, septic tank owners may cut corners and not use the best water treatment solutions. This makes us wonder: are septic tanks bad?

We all know about septic tank advantages. They are definitely better than cesspools.

Are septic tanks bad for the environment?


One thing is for sure – human activities have an impact on nature. It depends on us only how great that impact is.

Keep on reading to find out in what conditions septic tanks can be harmful for the environment. This article is for those who want to get rid of wastewater safely and efficiently.

When is a septic tank a good solution?


Those who have access to a municipal sewer have little to no reason to research types of septic tanks.

The reality is that centralized sewer systems are not available everywhere or connecting to them could be too expensive.

There are some very good and legitimate reasons to use a septic system:

Septic systems enable homeowners in rural areas to filter their wastewater;

Septic systems are more affordable than connecting to a public sewage system. This applies especially when your property is located on a large piece of land;

They last anywhere between 20 and 40 years when maintained properly;

When they filter wastewater effectively, they help to replenish depleting water tables and are actually good for the environment;

Malfunctions are more easily noticed compared to public sewers. This means that untreated water leaks are attended to immediately and contamination is reduced;

Multiple types of septic tanks are available, suiting various needs and preferences. In the next section we will be presenting the main types of septic tanks with their pros and cons.

What types of septic tanks are there?


There are multiple types of septic tanks, with different categories being determined by:

  1. The material the septic tank is made of;
  2. How wastewater is filtered and decomposed inside the septic tank.

Based on the first criterion, we have the following types of septic tanks:

  • Concrete

Concrete septic tanks are very durable and resilient. Their pros include the long lifespan and being able to drive over them or park on top of them.

However, concrete septic tanks also come with some drawbacks. They are more difficult to transport and install. They need lining because concrete is porous and they can be affected by water corrosion. Moreover, these tanks are more difficult to remove and replace.

  • Steel

Steel is a resilient material but it usually lasts less than concrete because it tends to rust. Steel septic tanks are rarely used by homeowners. They can be dangerous as rust can make them too weak to support the weight of the ground above it. As a result, they can collapse unexpectedly.

  • Plastic

Plastic septic tanks are widely used due to their low price and easy installation. They are less likely to crack compared to concrete.

Unfortunately, plastic tank users can also deal with problems. Plastic septic tanks can be damaged during installation or can be deformed by the immense pressure of groundwater. If they are not installed correctly, they can float to the surface.

  • Fiberglass

Fiberglass septic tanks are resilient, won’t crack or rust, and will not shrink due to pressure. There is just one issue with them – being so lightweight makes them more likely to float or shift their position.

The kind of bacteria that break down wastewater inside the tank give us two more types of septic systems:

  • Anaerobic

Anaerobic septic systems are airtight and contain bacteria that break down waste in the absence of oxygen.

The solid part of waste settles to the bottom while the relatively clean effluent is found in the middle. The top layer consists of scum (usually grease). The effluent leaves the tank through pipes with small holes at their ends and percolates into the surrounding soil.

Anaerobic systems have advantages such as low maintenance, reduced desludging costs, and working without the use of chemicals.

  • Aerobic

Aerobic systems rely on bacteria that use oxygen for respiration. Such systems have a more complicated design, with three tanks and an aerator forcing oxygen into the main treatment tank.

Aerobic systems clean water faster, but they have a larger number of mechanical parts. This means that aerobic septic systems are more prone to malfunctions. [1]

What risks are associated with a poorly maintained septic tank?



Now that we have a better understanding about septic tanks in general, let’s get back to our question.

Are septic tanks bad? Do they harm the environment?

The answer depends on the functionality of the septic tank. If the system is not properly maintained, it can contaminate the environment.

Here are some things that can go wrong with a neglected septic tank

  • Contaminating nearby water bodies

If the septic system is not working properly, untreated water can contaminate nearby water sources.

A septic system that is located too close to a drinking well water can contaminate the water. [1]Avoid placing the septic system too close to a well and be careful about its maintenance.

  • Releasing nitrates into the local water supplies

Nitrates are dangerous for persons with a low or compromised immune system. The large number of nitrates can also harm ecosystems.

  • Overflowing

A septic tank can overflow if you don’t pump out sludge regularly or if pipes become clogged. This can destroy your landscape and wreak havoc on your lawn. Wastewater can also back up into your drains and release foul odors into your home.

  • Water not being treated properly

Poor performance can happen when the bacteria inside the septic tank is not healthy and in good condition. In the next section, we will explain among others how to take care of the good bacteria.

Are septic tanks bad and will harm the environment?

As stated at the beginning of this post, they are not if they work properly.

Are you a septic system owner or thinking to install one? Here are some good practices you should adhere to:

  • Flush responsibly

You would be surprised at the items some people flush down the drain.

Whether you are connected to a municipal sewer system or you have your septic tank, keep in mind:

Flush human waste and toilet paper only.

Items that seem inoffensive, such as so-called flushable wipes and coffee grounds, are a problem too. They don’t decompose inside the tank and eventually cause blockages in your sewer pipes.

  • Don’t pour grease down the drain

Grease solidifies when it comes into contact with cold water. Obviously, it causes clogs and malfunctions in your septic system.

  • Pump sludge out regularly

The general rule is that you should pump out sludge once it starts to exceed 25% of the tank volume. If large quantities of sludge accumulate, the solid matter can clog pipes that evacuate effluent into the ground.

  • Use biodegradable detergents

You should ideally use biodegradable products for laundry. Non-biodegradable detergents can produce suds that block the septic system.

  • Take care of the working bacteria in the septic tank

Bacteria inside the septic tank can be damaged by harsh chemicals and antibacterial cleaning products. Opt instead for natural and biodegradable cleaning products.

Bacteria can also be negatively affected if you are on an antibiotic treatment. The antibiotics are excreted through urine and will reach the septic tank, affecting the bacteria inside it.

  • Limit water use

You should avoid overloading the septic tank so wastewater does not seep into the drain field. Measures for limiting water consumption include installing water-efficient fixtures and using water responsibly.

  • Conduct regular inspections

The best way to ensure that your septic system is not bad for the environment is having it professionally maintained. The frequency of inspections depends on the size of the tank and its type.

A septic system should be professionally inspected every 2 or 3 years. An expert will be able to give you advice on how to extend the life of your septic tank and avoid contamination. [2]

To Sum Up

Septic systems are actually good for the environment if they are properly maintained. There are multiple septic tank advantages, which sometimes make this solution superior even to centralized sewer systems.

Making sure that your septic system is not bad for ecosystems depends on you, its user. As long as you install it correctly and maintain it, you will be protecting and supporting the environment.