Executive Summary
- A septic system provides private wastewater treatment through natural biological decomposition, allowing homes to dispose of organic matter without being connected to a municipal sewer system.
- Conventional septic systems rely on settling, separation, and soil filtration, while advanced systems add extra treatment steps such as sand filtration and chemical- or UV-fueled disinfection.
- Key components of a traditional septic system include the tank, drain line, drain field, outlet pipe, and the soil it is buried within.
- Septic systems must be routinely maintained to prevent failures that can lead to groundwater contamination, health hazards, costly repairs, or extensive remediation projects.
Understanding How a Septic System Works
Over 60 million people in the United States use septic systems to dispose of organic household waste. Still, this private wastewater treatment method is not as common as traditional sewer systems, causing many people to wonder, “How does a septic tank work?”
To understand how a septic system works, you must educate yourself on its components—learn what a septic tank is, along with drain lines, drain fields, and outlet pipes. Conventional septic systems have various elements, but advanced septic systems usually have more, such as sand filters and disinfection chemicals. All system parts must work together to filter excrement and wastewater properly, making routine maintenance and inspections essential.
Read through the considerations below to educate yourself on how a septic system works. Then, consult a trusted professional for septic tank services and advice tailored to your unique situation.
What Is a Septic System?
A septic system is a private wastewater treatment method that processes sewage sent from household plumbing. This system uses natural, bacteria-dependent processes to break down and filter waste before strategically depositing treated water back into the soil. Septic systems are a common substitute for traditional municipal sewer systems, meaning they are usually found in rural or off-grid homes where centralized sewage systems are unavailable.
There are many different types of septic tanks, varying in material, complexity, and approach to wastewater processing. For instance, some septic tanks are made from concrete for durability and longevity, while others are made from fiberglass or plastic to be lightweight and rust-resistant. Additionally, some septic systems have extra bells and whistles to facilitate their job; it is important to know how both conventional and advanced septic systems function.
How Does a Conventional Septic System Work?
A conventional septic system follows a simple yet effective process. Some examples of the steps involved in this process may include:
- Wastewater enters the septic tank – Wastewater from sinks, toilets, tubs, and other household drains flows into the septic tank, where solids, liquids, and grease are separated.
- Solids settle – Denser solids naturally sink to the bottom of the tank, slowly mixing together to form sludge, while lighter materials, such as grease and oils, float to the top as scum.
- Effluent exits to the drain field – The liquid in the middle layer, also known as effluent, flows out of the tank into the drain field, where it is naturally filtered by soil.
A conventional septic system’s drain field comprises perforated pipes buried in gravel-filled trenches. As effluent leaches into the soil, contaminants and bacteria are removed before the water reaches groundwater sources, keeping inhabitants and nearby ecosystems safe.
How Does an Advanced Septic System Work?
Advanced septic systems incorporate additional treatment steps to promote better wastewater filtration, building on the effectiveness of a conventional system. Some examples of additive features that some advanced septic systems have are:
- Aerobic treatment – Some systems have an oxygen supply that enhances the bacterial breakdown of waste by creating an optimal environment for aerobic bacteria.
- Sand filters – Some systems implement sand to add an extra filtration layer before effluent reaches the soil, enhancing the system’s efficacy.
- Disinfection systems – To thoroughly neutralize waste-related pathogens, some systems are equipped with specialized chemicals or UV lights that disinfect the unit.
Although they are usually more expensive, advanced systems are popular in areas with poor soil conditions, high water tables, or strict environmental regulations requiring an enhanced wastewater treatment approach.
Parts of a Septic System
A septic system relies on multiple components, all of which must work harmoniously to process and filter wastewater effectively. The following elements are some of the most noteworthy parts of a conventional septic system.
Septic Tank
A septic tank is a large, watertight container that temporarily holds wastewater. Its job is to separate solids, liquids, and grease so effluent can move toward the drain field. Usually, septic tanks are crafted out of the following materials.
Concrete
This highly durable and long-lasting material is heavyweight, which prevents shifting or floating. Nevertheless, its heavier weight can make installation more labor-intensive and costly, and it is susceptible to cracking over time.
Fiberglass
Thanks to its lightweight construction, this material is usually easy to install and resistant to rust and corrosion. However, due to its lightweight nature, it can be prone to damage, especially if an experienced professional does not install it. Moreover, it can be more expensive than other material options, such as plastic.
Plastic
Like fiberglass, this material is lightweight, easy to install, and resistant to rust and corrosion. However, it is often less durable than concrete, making it susceptible to damage if a qualified specialist does not strategically install it. In fact, some local regulations prohibit the use of plastic septic tanks due to their lack of durability.
Steel
Steel septic tanks are known for being initially strong and durable, but they can rust over time. Their high susceptibility to corrosion can lead to a shorter lifespan, especially if they are not given regular inspections and maintenance. For this reason, they have become less common in recent years.
Drain Line
The drain line is an umbrella term used to reference the entire network of pipes that transport effluent from the septic tank to the drain field, where it slowly leaches into the ground to be filtered through natural processes. Drain lines are usually made of PVC or concrete. A functioning drain line is essential to ensure proper wastewater distribution throughout the drain field.
Outlet Pipe
Only liquid effluent is meant to be deposited into the drain field because solids can cause blockages, which may lead to sewage backups. The final pipe in the drain line, known as the outlet pipe, prevents sludge and scum from passing through by using a filter or baffle. Plus, the outlet pipe is usually located closer to the top of the tank, where the liquid effluent is clearest and contains the fewest solids.
Drain Field
The drain field filters wastewater naturally through layers of soil. It usually consists of perforated pipes strategically placed throughout gravel beds to allow effluent to disperse thoroughly. As the effluent is deposited in the drain field, the soil naturally treats it.
Soil
Soil acts as the final filtration stage for wastewater. It can remove bacteria and contaminants before the treated water reaches groundwater sources, helping protect inhabitants and local wildlife from sewage-related diseases and complications.
Advanced Treatment System (if applicable)
As mentioned earlier, to meet stricter environmental requirements, some septic systems include additional treatment components, such as aeration to nurture aerobic bacteria, sand filters for added filtration, or chemicals for disinfection.
Understanding the rudiments of each of the components mentioned above is essential to grasping the general functionality of a septic system.
The Importance of a Functioning Septic Tank
Regardless of your septic tank type, regular maintenance, like septic tank cleaning, is required to keep each component functioning properly. To protect public health and prevent environmental contamination, take care of the following septic tank components.
Inlet Baffle
The inlet baffle is a device that controls the flow of incoming wastewater into the tank. If it is not functioning properly, it can disturb settled solids and impede the separation process.
Settling Wastewater
Inside the septic tank, solids sink to form sludge, while oils rise to create scum, and liquid effluent remains in the middle layer to be deposited into the drain field. If this process is disrupted, it can overload the system, which may shorten its life or cause clogs that lead to sewage backups.
Sludge
Solid waste that collects at the bottom of the tank can accumulate over time. Regular septic tank pumping is necessary to avoid overflows and system failure. During this process, a professional uses tools like a muck rake and a specialized vacuum to agitate and remove sludge, freeing up space in the tank for continued use.
Outlet Baffle
This component within the outlet pipe prevents sludge and scum from leaving the tank, allowing only properly treated effluent to flow into the drain field.
A well-maintained septic tank guarantees that your property effectively separates and processes wastewater, prevents blockages, and ensures proper drain field treatment.
Why is Septic Tank Maintenance Essential?
Again, routine maintenance is crucial for extending the function and life of a septic system. For example, periodic inspections from a qualified professional can help you assess your system’s condition and catch potential issues as early as possible. Most inspections involve checking sludge and scum levels, evaluating the inlet and outlet baffles, and gauging the overall health of the drain field, looking for signs you need to replace your septic system.
Another critical aspect of septic system maintenance is regular pumping, which removes accumulated solids to prevent them from clogging the system and causing backups. Optimal pumping frequency depends on several factors, including the septic tank size, the number of people using the system, and the volume of wastewater the home generates.
If you invest in proper care and maintenance, you can ensure your septic system continues to operate efficiently, protecting your families, property, and the surrounding environment.
Choose Alpha Environmental for Dependable Septic System Services
Understanding how a septic system works is essential for homeowners who rely on conventional septic systems or advanced septic systems for private wastewater treatment. If you are still wondering, “What is a septic tank?” or “How does a septic tank work?” contact experienced environmental specialists like the ones from Alpha Environmental for expert-level insight and tailored guidance for all of your septic tank needs.
Our team offers dependable septic system services for properties throughout the greater Portland, Oregon, area, including inspections, maintenance, and repairs. We can help you keep your septic tank, drain line, and every other part of your system running smoothly to minimize the risk of soil or groundwater contamination, which can threaten the health of inhabitants and surrounding ecosystems.
Contact Alpha Environmental to help your septic system operate efficiently for years to come.
