Homes that are not connected to municipal sewer lines are typically equipped with septic systems. Septic systems are on-site waste disposal systems, which receive wastewater from a home’s plumbing system. Learn the basics of septic systems and how they treat waste from your home. Septic systems are actually quite common, serving more U.S. homes than other types of wastewater treatment.
Septic System Basic Components
Septic systems are composed of a septic tank and leach field. The septic tank is typically positioned close to the home, buried below ground. The access point to the tank may be marked above ground. Wastewater flows into the septic tank from the home, where it is treated. The EPA lays out the five steps taken in how a septic system typically works:
- All water runs out of your house from one main drainage pipe into a septic tank.
- The septic tank is a buried, water-tight container usually made of concrete, fiberglass, or polyethylene. Its job is to hold the wastewater long enough to allow solids to settle down to the bottom forming sludge, while the oil and grease floats to the top as scum.
- Compartments and a T-shaped outlet prevent the sludge and scum from leaving the tank and traveling into the drainfield area.
- The liquid wastewater (effluent) then exits the tank into the drainfield.
- The drainfield is a shallow, covered, excavation made in unsaturated soil. Pretreated wastewater is discharged through piping onto porous surfaces that allow wastewater to filter through the soil. The soil accepts, treats, and disperses… wastewater as it percolates through the soil, ultimately discharging to groundwater.
- If the drainfield is overloaded with too much liquid, it will flood, causing sewage to flow to the ground surface or create backups in toilets and sinks.
- Finally, the wastewater percolates into the soil, naturally removing harmful coliform bacteria, viruses and nutrients. Coliform bacteria is a group of bacteria predominantly inhabiting the intestines of humans or other warm-blooded animals. It is an indicator of human fecal contamination.
The septic tank will hold solid bio-waste leftover after bacterial breakdown and will need to be periodically pumped out to ensure it continues to work as intended.
A septic system’s leach field, also called an absorption system, further filters contaminants from wastewater. Following septic tank treatment, wastewater flows into the leach field, where soil works to perform additional filtering.
How Septic Systems Treat Waste
Septic systems use bacteria to break down pathogens in wastewater. Organic waste, such as kitchen waste and what’s flushed down the toilet, is reduced to new cell masses, water, and carbon dioxide. Septic wastewater treatment breaks down organic bio-waste matter to remove water-contaminating compounds such as nitrites and nitrates, as well as phosphorous.
Approximately 40 percent of wastewater filtration occurs within the septic tank portion of the system. Sixty percent occurs as septic treated wastewater flows into the leach field and is absorbed by surrounding soil.
Septic System Upkeep
Caring for your septic system will help it best manage wastewater. Follow these tips to keep it functioning properly:
- Have your septic tank pumped every two or three years to remove solids
- Reduce your system’s load by limiting what you put down the drain when possible. Compost kitchen waste, use non-toxic cleaning products, use liquid phosphate-free detergents in lieu of powders, and never dispose of chemicals down the drain.
- Never drain large amounts of water into the septic tank at once. This can reduce the time your wastewater is held in the tank, moving solids out faster so they don’t have time to be broken down. This can also cause your leach field to become clogged with sediment.
For homes tied to municipal wastewater treatment systems, Indiana American Water offers superior wastewater treatment solutions and the infrastructure needed to carry out treatment while delivering high-quality water back to your home. We’re making the infrastructure investments necessary to continue providing the quality water you need for everyday life. Learn more at www.indianaamwater.com