Anaerobic Septic System Explained & Differences Between Aerobic Septic System

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Anaerobic Septic System Explained & Differences Between Aerobic Septic System

Septic systems are an essential part of many household’s sewage disposal systems. As environmental concerns grow, people are now looking for ways to dispose of waste effectively while reducing their impact on the environment. In this regard, anaerobic septic systems have emerged as a popular alternative to the traditional aerobic septic systems.

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Anaerobic septic systems differ from aerobic systems in that they do not require the presence of oxygen to break down waste. Instead, bacteria breaks down the waste in an oxygen-deprived environment, releasing gases such as methane and carbon dioxide. This process leads to the formation of a thick sludge that settles at the bottom of the tank. The sludge is eventually pumped out, treated, and disposed of in a landfill.

One significant advantage of anaerobic septic systems over aerobic systems is that they require less energy to operate, resulting in lower operating costs. Additionally, anaerobic systems are more suitable for a rural environment compared to aerobic systems, which require regular maintenance and more water to function. As people increasingly opt for eco-friendly solutions, anaerobic septic systems offer an efficient and sustainable alternative to the traditional aerobic systems.

In this article we are going to dig deeper into explaining anaerobic septic systems and some of the key differences you need to understand from aerobic septic systems.

What is an Anaerobic Septic System?

An anaerobic septic system is a type of sewage treatment system that relies on natural bacteria to break down and decompose organic matter in wastewater.

Unlike aerobic systems, anaerobic systems do not require oxygen to function and operate in an oxygen-deprived environment. They are generally smaller than their aerobic counterparts and are best suited for smaller properties that do not have access to municipal sewer systems.

The process begins with wastewater flowing into the septic tank, where solids settle to the bottom and are broken down by anaerobic bacteria. The resulting liquid effluent then flows into a drain field, where it is further filtered and treated by soil microbes before being absorbed into the ground.

Anaerobic septic systems require regular maintenance, including routine pumping of the septic tank every three to five years, to prevent blockages and keep the system functioning properly. 

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How does an Anaerobic Septic System work compared to Aerobic Septic System?

Anaerobic and aerobic septic systems are two types of systems that are commonly used to treat wastewater in properties that are not connected to a sewage system.

The primary difference between the two systems is their oxygen requirements. Anaerobic systems do not require oxygen while aerobic systems do. In an anaerobic system, bacteria breaks down the organic matter in the wastewater through a process of digestion.

The solid material settles at the bottom of the tank, while the gases produced by the process escape through vents. In contrast, aerobic systems inject air into the treatment tank to provide the necessary oxygen for bacteria to thrive. This process results in fewer solids remaining in the tank and often produces lower levels of harmful bacteria and pathogens in the effluent.

Additionally, aerobic systems require more energy to operate due to the need for an air pump or blower. Both systems have their own advantages and disadvantages, and choosing between them depends on factors such as the size of the property, the soil composition, and the amount of water usage. 

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What are the components of an Anaerobic Septic System?

An anaerobic septic system comprises three principal components: the septic tank, the distribution box, and the absorption field. The septic tank is commonly designed with a capacity of 1,000 to 2,000 gallons, but some can hold as much as 3,500 gallons.

The septic tank is ordinarily made of concrete, polyethylene, or fiberglass with a top cover. The distribution box is the aspect of the system that directs the clarified wastewater from the septic tank to the absorption field. It is utilized as a junction box for three or more pipelines linked to it.

The absorption field is a layer of gravel or other similar components that help spread the wastewater and let it soak into the soil, divided among a series of trenches or beds. Its length and width vary on the system’s width and the number of pipes it has. An anaerobic septic system operates by trapping and breaking down organic waste utilizing bacteria.

Then, the wastewater will flow out to the absorption field to finish the process of becoming wastewater that is secure to the environment. 

What are the advantages and disadvantages of an Anaerobic Septic System?

Anaerobic septic systems are an alternative to traditional aerobic systems, which require constant energy input to function. Anaerobic systems require less energy to operate and produce less sludge, making them a popular choice for off-the-grid homes and rural areas with limited access to electricity.

However, this type of system produces methane gas, which is a potent greenhouse gas that contributes to global warming. Additionally, anaerobic systems require careful maintenance to prevent the buildup of toxic gases that can be harmful to both humans and the environment.

They also have a higher risk of system failure due to clogging and require regular pumping. Despite these disadvantages, anaerobic systems can be a cost-effective and sustainable solution for those seeking an alternative to traditional septic systems.

The advantages and disadvantages must be carefully weighed before making a final decision on the type of septic system to install. 

How can you maintain an Anaerobic Septic System?

Anaerobic septic systems are essential in treating wastewater in areas without access to a municipal sewer system. To ensure the proper functioning of these systems, certain maintenance strategies must be employed.

Regular cleaning of the septic tank is one of the primary ways to maintain an anaerobic septic system. This involves pumping the tank every three to five years to remove any accumulated solids or scum.

Another maintenance strategy is to minimize the introduction of harmful materials, such as plastics, grease, and toxic chemicals, into the system. These materials can clog the system, making it difficult for the anaerobic bacteria to break down the waste. In addition, monitoring the system’s performance is also critical in maintaining it.

Homeowners should regularly check the effluent levels in the drain field and ensure there are no leaks or obstructions. With proper maintenance, an anaerobic septic system can provide long-term, effective wastewater treatment for households and businesses. 

How Does an Aerobic Septic System Work?

Aerobic septic systems work by using oxygen to promote the growth of bacteria that break down waste materials. These systems are typically used in areas where traditional septic systems are not practical, such as rocky soil or land with a high water table.

The system consists of a primary tank that collects the raw wastewater and a secondary tank where the aerobic process takes place. Air is pumped into the secondary tank to encourage the growth of aerobic bacteria, which consume and break down the waste material.

The bacteria produce a sludge that settles on the bottom of the tank, while the water is treated and released into the drain field. Maintenance is necessary to ensure the system operates efficiently, including regular pump-outs of the primary tank, adding bacteria supplements to the secondary tank, and ensuring proper aeration.

Overall, aerobic septic systems are an effective and environmentally friendly alternative to traditional septic systems. 

What is the difference between an Aerobic and an Anaerobic Septic System?

The main difference between an aerobic and an anaerobic septic system lies in the way they treat wastewater. An aerobic system involves the use of oxygen to break down organic matter in wastewater, while an anaerobic system operates without oxygen.

Aerobic treatment systems usually feature an aeration unit that pumps air into the wastewater to support the growth of bacteria, which break down waste matter.

Anaerobic systems, on the other hand, utilize a sealed tank wherein bacteria thrive in oxygen-free environments to decompose solid wastes. Another significant difference is that aerobic systems produce clearer effluent compared to anaerobic systems, which result in sludge formation.

This makes aerobic systems a better choice when the treated water needs to be reused, like for irrigation or flushing toilets. Anaerobic systems, however, tend to be more affordable and require less maintenance. 

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What are the components of an Aerobic Septic System?

An aerobic septic system is a wastewater treatment system that relies on oxygen and bacteria to break down and treat the waste. The system consists of several main components including a septic tank, an aeration chamber, and a drain field. The septic tank is the first component of the system and is responsible for the initial separation of the wastewater into solids, liquids, and oils.

The Aeration chamber is the second component and is where oxygen is introduced to the wastewater to encourage the growth of aerobic bacteria. The bacteria break down the waste further, ensuring the removal of harmful contaminants. Lastly, the drain field is where the treated wastewater is dispersed into the surrounding environment.

This component uses a network of pipes and soil to filter the water as it is released into the ground. An aerobic septic system is an effective way to treat wastewater in areas with poor soil, high water tables, or limited space. 

What are the advantages and disadvantages of an Aerobic Septic System?

Aerobic septic systems are efficient and effective in treating household wastewater. They use oxygen to break down organic matter more rapidly than anaerobic systems.

The advantage is that they produce cleaner and clearer wastewater effluent, which can be used for purposes such as irrigation. Additionally, they require less space than traditional septic systems, making them ideal for small lots. Aerobic systems also require less maintenance and have a longer lifespan.

However, there are some disadvantages. These systems are more expensive to install and operate than conventional septic systems. They also require a constant supply of electricity to run the aeration pump, which can increase the energy bill. Additionally, if the pump fails, the system can quickly become overloaded and require costly repairs. Lastly, the effluent produced by these systems may not be suitable for discharge into certain waterways, which can limit the location where they can be installed. 

How can you maintain an Aerobic Septic System?

To maintain an aerobic septic system, there are several steps that you can take. First and foremost, regular inspection and maintenance is essential. The aerobic septic system should be checked at least once every six months by a professional. It is important to ensure that all the components are functioning as expected, and the system is operating efficiently.

Additionally, it is crucial to monitor the sludge levels in the system and have them emptied as necessary. Another vital aspect to consider is the materials that enter the system. Harsh chemicals and non-biodegradable substances should be avoided at all costs, as they can damage the system’s components.

It is recommended not to use bleach or antibacterial soap. Lastly, the system needs adequate oxygen levels to work correctly. Therefore, the system’s fans and air pumps must be functioning correctly at all times. Overall, regular inspections, monitoring of sludge levels, proper use of materials, and ensuring adequate oxygen supply are all crucial in maintaining an aerobic septic system. 

What are the Differences Between an Aerobic and an Anaerobic Septic System?

Let’s take a closer look at the differences between anaerobic and aerobic septic systems. 

How do they handle wastewater differently?

Anaerobic and aerobic septic systems are two different types of wastewater treatment systems that function differently. Anaerobic systems rely on bacteria that do not require oxygen to break down organic materials in wastewater.

These bacteria produce methane gas as a byproduct, which is released into the atmosphere. In contrast, aerobic systems use oxygen to facilitate the breakdown of organic matter in the wastewater, producing carbon dioxide, water, and other byproducts.

Aerobic systems tend to be more effective at removing pollutants than anaerobic systems, however, they also require more energy to operate due to the air blowers needed to keep the bacteria healthy.

Anaerobic systems are generally less expensive and more suitable for areas without access to electricity or where reliable plumbing is not available. In summary, anaerobic and aerobic systems handle wastewater differently, with anaerobic systems being simpler and less expensive while aerobic systems being more effective but more energy-intensive. 

How do they process solid waste?

When it comes to processing solid waste, aerobic and anaerobic septic systems operate in very different ways. Anaerobic systems work by breaking down waste in an oxygen-deprived environment (i.e. without the presence of oxygen). As the waste decomposes, it produces methane gas, which can be collected and used to power homes or businesses.

Aerobic systems, on the other hand, require oxygen to function. They use bacteria to break down organic matter and turn it into carbon dioxide and water. Because aerobic systems require oxygen, they are more efficient at breaking down waste than anaerobic systems.

However, they are also more expensive to install and maintain because they require a continuous supply of oxygen. Ultimately, the type of septic system you choose will depend on your budget and the amount of waste you need to process, but both aerobic and anaerobic systems are effective at turning solid waste into something that can be safely disposed of or even used as a source of renewable energy. 

Which system is more suitable for specific situations?

The decision to choose between an anaerobic or aerobic septic system depends on various factors. An anaerobic system might be more suited for rural areas without access to power. It is also less expensive to install and maintain compared to an aerobic system.

However, an anaerobic system is not recommended in areas with high water tables. In these situations, an aerobic system is more suitable as it requires oxygen to operate and not having it can lead to system failure.

Moreover, an aerobic system is better suited for larger households with more daily water usage. It also produces effluent of better quality than an anaerobic system. However, it is more expensive to install, requires frequent maintenance, and consumes a lot of energy to operate. In summary, it is important to evaluate the specific situation before choosing the most appropriate septic system. 

Aerobic vs Anaerobic: Advantages and Disadvantages

Aerobic septic systems typically have three separate tanks. Waste enters the first tank and settles into layers, then moves into the second tank (the treatment tank) where an aerator pumps bubbles of oxygen through the waste. This is where the aerobic bacteria digests the solid matter. Lastly, it moves to the third pump tank for final treatment. Of course, there are benefits and disadvantages to aerobic septic systems.

Aerobic Septic System
Advantages Disadvantages
Design: Aerobic septic systems offer a range of designs suitable for various set-ups. Cost: Installation, operation, and maintenance is almost twice that of anaerobic.
Environmental Pollution: multiple treatments yield less groundwater Weather: Extremely low temperatures adversely affect quality of treatment.
Space Requirements: Very little space is required for aerobic septic systems. Ideal for properties with limited space. Maintenance: More maintenance is required. If the system if poorly-maintained, treatment quality suffers or, worse, the system may fail.

Anaerobic septic systems are simpler than their aerobic counterparts. They consist of a septic tank and two main pipes: one that goes to the facility and one that goes into the yard. This second one splits into several smaller pipes and are situated just below the surface of the lawn. While solid waste settles in the tank and is eaten by anaerobic bacteria, liquid waste floats to the top, moves to the smaller pipes under the surface of the soil, and then filters out into the soil. Likewise, there are advantages and disadvantages to anaerobic systems.

Anaerobic Septic System
Advantages Disadvantages  
Availability: Aerobic systems are more commonly installed, thus more readily available. Pumping: Lesser tanks and so may require more frequent pumping.  
Cost: Less complex set-up means a lower price tag. Resale Value: Still a lot of people are not used to maintaining on-site septic systems.  
Environmentally-Friendly: No chemicals are required in cleaning the system. Solid Waste: With only one tank and pipe system, anaerobic systems are more sensitive to solid waste.  

Can an Anaerobic Septic System be converted to an Aerobic one?

Yes, it is possible to convert an anaerobic septic system to an aerobic one. An anaerobic system relies on bacteria that break down waste in an oxygen-free environment, while an aerobic system uses oxygen to help break down waste.

The conversion process usually involves retrofitting the existing septic tank with an aerobic treatment unit or replacing the existing tank with a new one designed for aerobic treatment.

This conversion can be beneficial in terms of improved effluent quality and reduced odors. An aerobic system typically requires electricity to operate and periodic maintenance to keep the oxygen supply and bacterial balance optimal. It is important to note that conversion to an aerobic system may require permits and compliance with local regulations.

It is recommended to consult with a licensed professional before making any modifications to a septic system. 

Benefits of an Anaerobic Septic System

Lets take a closer look at the anaerobic septic system. 

What are the cost implications of installing an Anaerobic Septic System?

The cost implications of installing an anaerobic septic system can vary depending on the type and size of the system needed, as well as installation and maintenance factors.

Typically, anaerobic systems are cheaper to install than other septic systems, with prices ranging from $3,000 to $10,000. However, maintenance costs can be higher due to the need for regular sludge removal, which can cost around $500 to $1,000 per year.

Additionally, these systems may require more frequent cleaning and pumping due to their smaller size and limited ability to handle larger volumes of waste.

Overall, while the upfront cost of an anaerobic septic system may be lower, the ongoing maintenance costs should also be carefully considered to ensure that it is the most cost-effective option for your needs. 

How does an Anaerobic Septic System affect the environment?

An anaerobic septic system is a sewage treatment system used in areas where there is no connection to a municipal sewage system. This system is eco-friendly, as it does not require electricity to operate, and reduces water usage compared to conventional septic systems.

However, if the anaerobic septic system is not properly maintained, it can have a negative impact on the environment. The untreated effluent can seep into the groundwater and contaminate nearby drinking water wells, lakes, rivers, and other waterways. This can lead to the spread of waterborne diseases, affect aquatic life and biodiversity, and harm human health.

Furthermore, the release of excess nitrogen and phosphorus from the septic system can lead to eutrophication, which is the excessive growth of algae in water bodies, negatively affecting aquatic ecosystems. Therefore, it is crucial to regularly maintain and dispose of the wastewater from anaerobic septic systems to prevent harmful impacts on the environment. 

Are there any incentives for homeowners to install an Anaerobic Septic System?

There may be some incentives for homeowners to install an anaerobic septic system. One potential benefit is the cost savings associated with the system.

Anaerobic septic systems can save homeowners money on infrastructure and maintenance costs compared to traditional septic systems, as they require less electricity and fewer chemicals for treatment. Additionally, some municipalities offer tax credits or grants to homeowners who choose to install anaerobic systems, as they are typically considered to be more environmentally friendly and energy-efficient.

However, it is important to note that the availability of these incentives can vary widely depending on your location and local regulations. Therefore, homeowners should thoroughly research their area’s policies and consult with a qualified professional to determine whether an anaerobic septic system is the right choice for them. 

What other benefits can you get from using an Anaerobic Septic System?

Aside from being an effective and low-maintenance wastewater treatment solution, anaerobic septic systems offer several additional benefits. One of the primary benefits of an anaerobic septic system is that it produces methane gas as a byproduct of the natural bacterial breakdown of organic waste.

This gas can be captured and used as an alternative energy source for heating or powering homes and businesses. Additionally, because anaerobic systems do not require electricity or chemical treatment, they are an eco-friendly choice that saves energy and minimizes the use of harmful chemicals in the environment.

The effluent produced by the system can also be used as a nutrient-rich fertilizer for gardens and landscaping, making it a sustainable and cost-effective solution for homeowners and businesses alike. Overall, using an anaerobic septic system offers a range of benefits beyond simply treating wastewater, making it a smart choice for those interested in both environmental sustainability and cost savings. 

Benefits of an Aerobic Septic System

And here are the benefits of aerobic septic systems. 

What are the cost implications of installing an Aerobic Septic System?

Installing an Aerobic Septic System can have significant cost implications, both immediately and in the long run. The initial installation cost typically ranges from $3,000 to $7,000, which is higher than traditional septic systems.

However, the costs are offset by lower maintenance expenses in the long term. Aerobic Septic Systems require electricity to operate, and the cost of maintaining an electric aerator can add up over time.

Furthermore, there are additional costs associated with pumping the effluent from the system, which should be done at least once a year. Another aspect to consider is the replacement of the aerator, which can cost up to $1,000. Overall, the cost of installing an

Aerobic Septic System may be higher than traditional septic systems, but the long term maintenance costs are lower, and the system is more environmentally responsible. It is recommended to consult with a professional to determine the most appropriate septic system for the property and budget. 

Cost to Operate. Typically, anaerobic septic system installation is a lot simpler and therefore less costly. Aerobic septic systems, on the other hand are more expensive to install, not to mention maintain than anaerobic septic systems. Because aerobic septic systems are built with more moving mechanical parts, such as the aerator, they are more prone to mechanical malfunction and will typically require routine maintenance more frequently. Also, aerobic septic systems require electricity to operate, and so they can become a strain on one’s monthly electricity bill.

    Aerobic Anaerobic
Conventional Systems
Assessments and Permits $200 to $400 $250 to $1,000, depending on location
System and Installation $10,000 to $20,000 $2,000 to $5,000
Pumping and Maintenance $200 every 1 to 3 years $200 to $600 every 1 to 3 years
Septic Tank $500 to $2,000 $500 to $2,000
Others Aerobic systems may need motor & timer replacements over time. Motor replacements may cost between $500 & $600; timers average $100 Piping and related materials have an average cost between $100 and $200

How does an Aerobic Septic System affect the environment?

An Aerobic Septic System is an environmentally friendly sewage treatment option. It helps to prevent soil and water pollution. The system uses oxygen to break down the waste and convert it into water, carbon dioxide, and organic matter.

This process is completed by a combination of bacteria, fungi, and protozoa that exist within the system. Unlike other sewage treatment options, the aerobic septic system produces a clean effluent that can be safely discharged into the environment.

This effluent can be used for irrigating crops, water-saving, and other purposes. Additionally, the system reduces the spread of harmful pathogens and prevents the accumulation of harmful chemicals that could contaminate the environment.

With proper maintenance, an Aerobic Septic System can last for many years and reduce environmental pollution while protecting public health. 

Are there any incentives for homeowners to install an Aerobic Septic System?

There may be several incentives for homeowners to install an Aerobic Septic System. One of the primary benefits is that these systems are more environmentally-friendly compared to traditional septic systems.

This is because Aerobic Septic Systems have an additional chamber that uses oxygen to break down the waste material more efficiently, resulting in cleaner discharge. Additionally, installing this system may increase the value of the property. In some states, such as Texas, homeowners may qualify for various tax incentives and rebates upon installing an Aerobic Septic System.

The local government may also offer subsidies for homeowners to install Aerobic Septic Systems, especially in areas with high concentrations of traditional septic systems that are polluting the environment. Lastly, the system requires less maintenance than conventional septic systems, and the regular pumping of sewage is not required as often, resulting in long-term savings. Therefore, installing an Aerobic Septic System may have both financial and environmental benefits for homeowners. 

What other benefits can you get from using an Aerobic Septic System?

Apart from being eco-friendly and cost-effective, aerobic septic systems have several other benefits. One of the most significant advantages is that they treat wastewater much more efficiently than traditional septic systems.

The aerobic process enables the breakdown of waste more thoroughly, eliminating harmful bacteria and reducing the amount of solids in the wastewater. This ensures that the effluent discharged from the system is much clearer and less hazardous to the environment, protecting water sources and local ecosystems. Additionally, because they require less maintenance and fewer pumping cycles than conventional septic systems, aerobic systems are more convenient and economical for homeowners.

Furthermore, some states may offer tax rebates and incentives for homeowners who install environmentally-friendly systems like aerobic septic systems, making them not just a good investment for homeowners but a responsible choice for the environment. Overall, using an aerobic septic system provides homeowners with many benefits and a more sustainable option for treating sewage, while contributing to creating a healthier world. 


Q: What is an anaerobic septic system?

A: An anaerobic septic system is a type of septic system that relies on anaerobic bacteria to break down and decompose solid waste in the absence of oxygen.

Q: What is the difference between aerobic and anaerobic septic systems?

A: Aerobic septic systems rely on aerobic bacteria that need oxygen to live and function. Anaerobic septic systems, on the other hand, rely on anaerobic bacteria that function in the absence of oxygen.

Q: What is a conventional septic system?

A: A conventional septic system is a type of anaerobic septic system that consists of a septic tank and a leach field. The septic tank separates solids and liquids, and the wastewater is distributed into the leach field for further treatment and disposal.

Q: What is a mound septic system?

A: A mound septic system is a type of aerobic septic system that is used in areas with high water tables, poor soil quality, or other conditions that make conventional septic systems impractical. A mound is constructed over the leach field to improve drainage and treatment of the wastewater.

Q: What is the function of a septic tank?

A: A septic tank is a key component of a septic system. It separates solid waste from liquids, and allows the anaerobic bacteria inside the tank to decompose and break down the solids into simpler compounds.

Q: What type of bacteria is found in a septic tank?

A: Anaerobic bacteria are the primary type of bacteria found in septic tanks. They are able to break down organic matter in the absence of oxygen, and produce methane gas and other byproducts as part of the decomposition process.

Q: What is the difference between aerobic and anaerobic treatment?

A: Aerobic treatment uses aerobic bacteria that require oxygen to live and break down organic matter. Anaerobic treatment relies on anaerobic bacteria that can break down organic matter without the need for oxygen.

Q: What is an aerator in a septic system?

A: An aerator is a device that is used in aerobic septic systems to introduce oxygen into the wastewater to promote the growth of aerobic bacteria and improve the treatment process.

Q: Are anaerobic systems still commonly used?

A: Yes, anaerobic systems are still commonly used, especially in areas where the soil is suitable for the subsurface distribution of treated wastewater.

Q: What is a filter in a septic system?

A: A filter is a component that is used in some septic systems to remove suspended solids from the wastewater before it enters the leach field. This helps to protect the leach field from clogging and extends the life of the system.

uire more attention and resources than anaerobic systems, though promise better results altogether.

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