Understanding the Anaerobic Septic System: A Complete Guide

Septic systems are a common method of waste management in rural areas or homes not connected to municipal sewer systems. There are two types of septic systems: aerobic and anaerobic. In this article, we will focus on the anaerobic septic system, how it works, and its advantages and disadvantages.

An anaerobic septic system is a type of septic system that relies on anaerobic bacteria to break down organic waste. Anaerobic bacteria are bacteria that do not require oxygen to survive. In an anaerobic septic system, wastewater from a house or building is directed to a tank where it is held until solids settle to the bottom and form a sludge layer. The remaining wastewater then flows to a second tank, where it is further treated by anaerobic bacteria.

The process of anaerobic digestion breaks down organic matter in wastewater, producing gases like methane and carbon dioxide. These gases are released into the atmosphere, and the remaining liquid is released into the soil through a drain field.

One of the advantages of an anaerobic septic system is that it is less expensive to install than an aerobic system. The absence of aeration equipment and other components that an aerobic system requires makes it less expensive to maintain. Additionally, anaerobic septic systems require less energy than aerobic systems, which can save homeowners money in the long run.

However, there are also some disadvantages to using an anaerobic septic system. One of the main disadvantages is that it produces unpleasant odors. Anaerobic bacteria produce a sulfuric smell that can be unpleasant for homeowners, especially during warmer months. Additionally, an anaerobic septic system does not treat wastewater as thoroughly as an aerobic system, which can lead to a greater risk of groundwater contamination.

Another disadvantage of an anaerobic septic system is that it requires more frequent maintenance. The sludge layer at the bottom of the tank must be pumped out regularly, typically every three to five years, to prevent buildup that could lead to clogs or damage to the system.

Here are the different parts of an anaerobic septic system:

Septic Tank

The septic tank is the primary component of an anaerobic septic system. It is a large underground tank that collects and holds wastewater from the home. The septic tank is divided into two chambers, which are separated by a baffle. The first chamber receives the wastewater from the house and allows solids to settle to the bottom. The second chamber allows further treatment by anaerobic bacteria before the liquid is released into the soil through a drain field.

Inlet and Outlet Pipes

The inlet pipe carries wastewater from the home to the septic tank, while the outlet pipe carries treated wastewater from the second chamber of the septic tank to the drain field.

Baffle

The baffle is a dividing wall inside the septic tank that separates the first and second chambers. The baffle ensures that only liquid flows into the second chamber, allowing further treatment by anaerobic bacteria.

Drain Field

The drain field is a network of perforated pipes that allow the treated wastewater to be released into the soil. The pipes are covered with gravel and soil, which helps to filter out impurities before the wastewater is absorbed into the ground.

Vent Pipe

The vent pipe is a vertical pipe that allows gases, such as methane and carbon dioxide, to escape from the septic tank. The vent pipe helps to prevent pressure buildup in the tank, which can cause damage to the system.

Access Ports

Access ports are located on the top of the septic tank and allow for easy inspection and maintenance of the system. They are typically covered with a lid that can be easily removed.

How much does an anaerobic septic system cost?

The cost of an anaerobic septic system varies depending on several factors, such as the size of the property, the number of people living in the house, the type of soil on the property, and the local regulations. However, in general, anaerobic septic systems are less expensive to install than aerobic septic systems because they require fewer components.

The cost of installing an anaerobic septic system can range from $2,000 to $8,000, depending on the factors mentioned above. This cost includes the installation of the septic tank, inlet and outlet pipes, baffle, drain field, and any necessary permits and inspections.

It is important to note that the cost of an anaerobic septic system is not a one-time expense. Homeowners will also need to consider ongoing maintenance costs, such as regular pumping of the septic tank, which typically costs between $250 to $500 every three to five years. Additionally, homeowners may need to invest in repairs or upgrades to the system over time.

It is always recommended that homeowners consult with a licensed septic system installer in their area to obtain an accurate estimate of the cost of installing an anaerobic septic system. Local regulations may also impact the cost of installation and maintenance, so it is important to be aware of these regulations before making any decisions.

Anaerobic Septic System vs Aerobic Septic System

Here are some key differences between anaerobic and aerobic septic systems:

• Bacteria Type: Anaerobic septic systems rely on anaerobic bacteria that break down organic waste in the absence of oxygen. Aerobic septic systems use aerobic bacteria that require oxygen to break down organic waste.
• Treatment Process: In anaerobic systems, the wastewater is stored in a septic tank where the anaerobic bacteria break down the organic waste. The treated wastewater then flows into the drain field for further treatment. In aerobic systems, the wastewater is treated with the help of an aerobic treatment unit (ATU) that introduces oxygen into the wastewater to encourage the growth of aerobic bacteria. The treated wastewater then flows into the drain field.
• Energy Consumption: Aerobic septic systems require a constant supply of electricity to power the ATU, air pumps, and other components. Anaerobic systems, on the other hand, do not require any external power source.
• Maintenance Requirements: Aerobic systems require more maintenance than anaerobic systems due to the complexity of the ATU and other components. The ATU needs to be cleaned and serviced regularly to ensure proper functioning. Anaerobic systems, on the other hand, require less maintenance, with only the septic tank requiring periodic pumping.
• Cost: Aerobic systems are generally more expensive to install and maintain than anaerobic systems due to the additional components and energy requirements.

Both anaerobic and aerobic septic systems have their own advantages and disadvantages. While aerobic systems are more efficient in treating wastewater, they require more maintenance and energy consumption. Anaerobic systems, on the other hand, require less maintenance and are less expensive to install and operate. The choice between the two depends on factors such as local regulations, property size, soil type, and budget constraints. It is important to consult with a licensed septic system installer to determine which system is best suited for your specific needs.

Anaerobic Septic Systems vs Public Sewer

Here are some key differences between anaerobic septic system and public sewer:

• Cost: The cost of an anaerobic septic system is typically lower than that of connecting to a public sewer system. Anaerobic systems have a lower installation cost and require less maintenance than public sewer systems. In contrast, public sewer systems require significant infrastructure and ongoing maintenance, which can result in higher costs.
• Maintenance: An anaerobic septic system requires periodic pumping of the septic tank and maintenance of the drain field, while a public sewer system is maintained by the public entity responsible for the system. Therefore, homeowners are responsible for maintaining their anaerobic septic system, while the public entity is responsible for maintaining the public sewer system.
• Environmental Impact: Anaerobic septic systems are designed to treat wastewater on-site, which can reduce the environmental impact of wastewater treatment. Public sewer systems, on the other hand, transport wastewater to a centralized treatment facility, which can have a greater environmental impact due to the energy required to transport and treat the wastewater.
• Regulation: Both anaerobic septic systems and public sewer systems are subject to local regulations. However, public sewer systems are typically subject to more stringent regulations due to their potential impact on public health and the environment.

Anaerobic septic systems and public sewer systems have their own advantages and disadvantages. While anaerobic septic systems are generally less expensive and have a lower environmental impact, public sewer systems offer the convenience of centralized management and maintenance. The choice between the two depends on factors such as local regulations, property size, and budget constraints. It is important to consult with a licensed septic system installer and/or a representative from the local public sewer system to determine which option is best suited for your specific needs.

Conclusion

In conclusion, an anaerobic septic system is an effective method of waste management that relies on anaerobic bacteria to break down organic waste. It is less expensive to install and maintain than an aerobic system, but it does produce unpleasant odors and requires more frequent maintenance. Ultimately, the decision to use an anaerobic septic system will depend on the specific needs of the homeowner, the size of the property, and the local regulations regarding septic systems.