A Guide: How Septic Tanks Work by FloHawks

Although few homeowners may ever want to see their septic system in operation, septic systems are one of the most important systems in your home – collecting, treating, and disposing of your household wastewater every day. And that is no small feat as an average home can produce 250 to 300 gallons of wastewater per day! Your septic tank collects anything that goes down the drain in your home. When properly designed, constructed, and maintained, your septic system can provide long-term, effective treatment of household wastewater to effectively reduce or eliminate human health and environmental threats.

Your Septic Tank

A Guide: How Septic Tanks Work by FloHawksAll the wastewater from your toilet, bath, kitchen, and laundry flows into the septic tank. The septic tank is a large, underground container where the bacteria does its job breaking down solids. Heavier matter that goes through your plumbing, like toilet paper and other solids, sink to the bottom of the tank where bacteria reduce them to sludge and gasses. Lighter solids and organic matter like oils, fats, and proteins float to the top to create a scum layer. Solids that do not decompose remain in the tank. Even when the bacteria are doing their job, undigested solids will slowly start to accumulate on the bottom of the tank through regular use.

However, most of your septic tank is comprised of effluent – gray water that once carried sludge and scum. Over time, through regular use of your septic system, the sludge and scum levels will begin to rise and eventually you will need to have your septic tank cleaned or pumped out. Be conscious of what goes down your drains; excessive fats, oils, and greases can require you to need your tank to be pumped more often. Your actual pumping schedule will depend on the size of the tank and your individual system’s level of use, or abuse, but a rule of thumb average is once every 3 to 5 years.

The Drain Field

After passing through the septic tank, effluent flows out into the drain field. Drain fields (also called leach fields or subsurface soil absorption fields) are a type of wastewater disposal system designed to treat and disperse the effluent from septic tanks. The basic function of a drain field is to deal with the septic tank effluent by allowing it to percolate into the ground. Well-designed and maintained drain fields are an effective way to remove disease-causing microorganisms from septic tank wastewater (effluent).

Drain fields are very important, and typically, the most expensive component of the septic tank drainage system. Drain fields typically consist of a series of perforated pipes laid in long, shallow, gravel-filled trenches that are buried below the ground’s surface. The gravel helps to distribute the wastewater over a large area as the effluent seeps through the gravel and into the underlying layers of soil.

Wastewater Treatment

As the effluent flows slowly through layers of soil, a variety of complex physical, biological, and chemical processes combine to provide treatment and purification. Soil particles filter, or chemically react with, solids and organic matter from the wastewater. Bacteria and other organisms in the soil consume the organic matter in the wastewater and perform most of the treatment. As a drain field matures, microbes living in the soil break down the solids and kill the bacteria in the wastewater. Although some treatment also may occur in the gravel layer, the soil provides most of the wastewater treatment. The soil in the drain field provides the final treatment and disposal of the septic tank effluent.

The septic drain field also has the biggest influence on the septic system life expectancy. Regular maintenance of your system is important, especially for the drain field. The size of the drain field and the capacity of the ground to absorb settled wastewater depend largely on individual site conditions including the type and texture of the soil, the area’s topography, and the volume of wastewater produced.

Proper Care and Maintenance

The useful life of a system depends on several factors like proper design, sizing, and installation, soil composition, the water table, number of nearby trees, amount of use and abuse, and most importantly, proper routine maintenance and pumping. Lack of maintenance is a common cause of early system failure. If your tank is not periodically pumped out (every 3 to 5 years), solids will accumulate, sludge and scum layers can grow thick, and eventually overflow into the drain field, causing foul-smelling water rising to the surface and extensive damage.

Being mindful about what you and your family put into your septic system can also extend its useful life. It doesn’t take much to upset the delicate balance of bacteria within the tank. For more information on how to best maintain your septic system click here for FloHawks’ tips on the Proper Care and Feeding of Your Septic Tank.

Call the professionals at FloHawks anytime at 1-800-356-4295 or use our  convenient Schedule Your Service tool, which allows you to set an appointment that best fits your schedule. We are available 24/7 for all your septic tank needs.