How Do Septic Systems Work?

Cesspool,on,the,backyard,green,lawnSeptic systems are a common wastewater treatment method for homes that are not connected to a municipal sewer system. If you live in a rural area or have a large property, chances are you rely on a septic system to manage your household wastewater. But have you ever wondered how these systems actually work? In this blog post, we will explore the inner workings of septic systems and how they effectively treat and dispose of wastewater.

What is a Septic System?

Before we delve into the workings of septic systems, let’s first understand what they are. A septic system is a small-scale onsite wastewater treatment system that is typically used in areas where there is no access to a public sewer system. It consists of a septic tank, where the wastewater is collected and partially treated, and a drainfield, also known as a leachfield, where the treated effluent is dispersed into the ground.

The Septic Tank

The septic tank is the primary component of a septic system. It is a waterproof, underground container made of concrete, fiberglass, or plastic. The tank receives all the wastewater generated from your home, including wastewater from toilets, sinks, showers, and laundry. As the wastewater enters the tank, it undergoes a process of separation and settling.

Inside the septic tank, the heavier solids, known as sludge, settle to the bottom, while lighter materials such as grease and oils float to the top, forming a scum layer. In between these layers, the relatively clear liquid, called effluent, is present. The septic tank is designed with compartments or baffle walls to help facilitate this separation process.

Bacterial Breakdown

Once the wastewater is in the septic tank, bacterial action begins to break down the organic matter present in the effluent. These bacteria are naturally occurring and present in our digestive systems as well. They decompose the solids, converting them into simpler compounds and gases. This biological breakdown is a critical step in the treatment process and helps reduce the volume of solids in the wastewater.

Effluent Disposal

After the solids have settled and been partially decomposed in the septic tank, the liquid effluent is ready to be discharged into the drainfield. The drainfield is a network of perforated pipes buried in trenches or beds in the soil. The effluent is evenly distributed over the drainfield, allowing it to percolate into the soil gradually.

The soil acts as a natural filter, further treating and purifying the effluent before it joins the groundwater. As the effluent moves through the soil, it undergoes biological, chemical, and physical processes that remove remaining bacteria, viruses, and other contaminants. The clean, filtered water is then absorbed by the soil and eventually becomes part of the groundwater system.

Maintenance and Care

To ensure the proper functioning and longevity of a septic system, regular maintenance and care are essential. Here are some key maintenance tasks associated with septic systems:

1. Pumping: Over time, the solids in the septic tank accumulate and need to be removed through a process called pumping. It is recommended to have the septic tank pumped every three to five years, depending on the size of the tank and the household usage.

2. Water Conservation: Conserving water helps prevent overloading the septic system. Reducing water usage by installing low-flow fixtures, fixing leaks, and spacing out the use of appliances that require a large amount of water can help protect the functionality of the system.

3. Avoiding Harmful Substances: Certain substances, such as excessive household cleaners, chemicals, medications, or fats, oils, and grease, can disrupt the natural treatment process of the septic system. It is important to avoid dumping these substances down the drain and follow good waste disposal practices.

4. Inspections: Regular inspections by a professional septic service provider can help identify any potential issues or signs of system failure. It is recommended to have a comprehensive inspection every three to four years to assess the condition of the septic system.


Septic systems play a vital role in treating and managing household wastewater in areas where there is no access to a public sewer system. By understanding how septic systems work and following proper maintenance and care practices, homeowners can ensure the efficient operation of their septic systems and protect the environment.

Got Questions? Let Us Help!

Gullett Sanitation Services, Inc. offers mobile de-watering of sludge and slurries in and around Bethel, OH, utilizing Roediger belt filter presses, as well as services and repairs on all major brands of home aeration systems. We also work with jet aeration and cleaning for sewer system lines (up to 8 inches in diameter), permits and consultation for biosolids, the transportation of non-hazardous wastewater, sludge removal from all types of waste lagoons, service and repairs on residential sewer systems, and the removal of grit, rags, and debris from anaerobic or aerobic digesters. Give us a call today and let us be your septic and dewatering service in Ohio!