How Does a Septic Tank Work?

A septic tank is a buried, water-tight container made from concrete or high-quality polyethylene. It holds wastewater from homes until bacteria break down organic solids and separate floatable fats, oils, and greases.

Bacteria-decomposed waste flows through a distribution box with perforated pipes into an absorption area called a drain or leach field. Contact Septic Tank Armadale now!

All the water in your house runs through one main drainage pipe into a septic tank underground. The septic tank is a buried, water-tight container made from concrete, fiberglass, or polyethylene. It holds the wastewater long enough for heavy solids to sink to the bottom, forming sludge, while oil and grease float to the top, forming scum. Compartments and a T-shaped outlet prevent the sludge and scum from leaving the septic tank with the liquid wastewater (effluent).

The bacteria in the septic tank slowly digest the organic waste in the sludge layer, which is periodically removed as part of general maintenance. The liquid wastewater leaves the septic tank and travels into a septic drain or leach field.

A septic system has to be carefully designed and constructed to work properly. Failing septic systems allow sewage to enter nearby drinking water wells and local waterways, polluting the environment and making people sick. This happens because pathogenic bacteria, viruses and other contaminants, as well as excess nutrients like nitrogen and phosphorus, are released into waterbodies. The nutrients encourage algae to grow, which consumes the oxygen needed by fish and other aquatic organisms. This decomposition releases toxins into the water that can make humans sick and cause irritation to plants and animals.

In addition, septic tanks that are too small or not regularly maintained may overflow and release sewage directly into the environment. Overflowing septic tanks may also damage the soil in the drainfield, contaminating groundwater and surface waters.

Some people use chemical and biological additives to help the septic system process waste faster or more efficiently. However, these additives can actually harm the bacteria that are naturally present in the septic tank. They can also disrupt the bacterial balance that helps to treat wastewater and septic tank effluent.

In most septic systems, wastewater is piped to a drain field, sometimes called a leach field, in a gravel- or stone-filled trench underground. The effluent trickles downward through the soil layers, where bacteria further treat and digest the wastewater. In some septic systems, pumps are used to help the liquid drain faster through the sand or gravel.

Sludge

Having to regularly clean out and pump your septic tank may seem like an unpleasant chore but it is actually very important. The main reason for this is that septic tanks, over time, can build up with inorganic waste material that will eventually need to be pumped out of the tank.

This inorganic material is a composite of all the natural waste that you flush down your toilets, including soap scum, oils and grease, unconsumed food particles, and more. When the septic tank is full of these materials the usable volume within the tank is reduced and solids are not being separated effectively.

In a properly maintained septic tank, bacteria in the scum and sludge layers cause organic matter to be broken down to a liquid state and then taken into the effluent layer. This naturally clarifies the wastewater. The bacteria also digest any contaminants and pathogenic microorganisms that are in the sludge and scum layers of the septic tank.

However, if the septic tank is not pumped out regularly or if the sludge level is too high then solids will not be separated adequately and will flow into the drain field where they can clog pipes and cause other problems. To avoid this, it is recommended that you use a septic tank waste digestion product (such as Muck Munchers) to help reduce the sludge in your septic tank and keep it to a minimum.

The final part of the septic system is the absorption area, sometimes called a drain field, leach field, or percolation field. It is a network of shallow underground pipes that have small holes in them. The liquid from the septic tank enters the pipes and flows down through soil layers where the soil acts as a filter. This process ensures that the sewage is fully treated before it gets into groundwater.

In the past septic sludge was often simply buried in landfills but this was banned when it became known that it was a health hazard and caused environmental pollution. Now, septic tank sludge is typically recycled or used as a soil conditioner.

Scum

After wastewater leaves residences through drain pipes, it flows into a buried septic tank. The septic tank, typically made of concrete, fiberglass or plastic, is usually located close to homes and contains two chambers. After the water enters the tank, density differences automatically separate it into three sewage layers. The heavier solids sink to the bottom of the first chamber, while the lighter substances float to the top. These are called the scum and sludge layers respectively.

The sludge layer is composed of a thick, indigestible mix of organic waste materials that settle at the bottom of the tank. While this is a natural process, excessive sludge buildup can cause septic system failure by blocking the septic tank outlet pipe or disrupting the flow of sewage to the drain field. This can lead to costly system repairs or even replacement.

This sludge buildup is caused by many things. One of the main reasons is because people flush too much paper down the toilet – this can form a thick wad that doesn’t break down, but instead just accumulates and blocks up the drain field. Other common causes of sludge buildup are food scraps, grease and oils (FOGs) from the kitchen, and diapers. All of these items should never be flushed down a toilet, but should be thrown in the garbage instead.

To prevent septic sludge buildup, a properly functioning septic system should have a well-designed inlet baffle that dissipates the force of incoming water and directs it downward. This forces the scum and sludge to separate into the liquid layer, making it more difficult for FOGs to rise up into the scum layer.

When a septic tank is maintained correctly, bacteria inside the septic tank will break down organic material in both the sludge and scum layers into smaller particles. As this happens, the sludge and scum will eventually liquefy and be drawn into the effluent layer. This process also keeps septic tanks from crusting over, reducing the frequency of septic tank pump outs.

Drain Field

A septic tank holds wastewater long enough for the solids to settle to the bottom and floatable waste like fats, oils, and grease to float to the top. After this purification process the liquid wastewater (effluent) exits into a drain field.

The drain field is a series of perforated pipes, typically made of porous material such as gravel, that are buried underground. The drain field’s purpose is to disperse the septic tank’s effluent into soil and allow it to be absorbed naturally by the ground. The drain field is a crucial part of the septic system, and without it, a septic tank would simply overflow and cause runoff in your yard.

As you use your home’s plumbing, wastewater travels from your sinks, toilets, bathtubs and showers through a line leading to the septic tank. The septic tank is a large, buried container that holds the wastewater until it reaches capacity. When the septic tank is full, the solids and oil will be pushed to the drain field while the effluent is released into the soil.

Once the effluent leaves the septic tank, it is absorbed into the soil by microbes. The bacteria in the soil help to further treat the wastewater and reduce or eliminate contaminants. The wastewater will eventually reach the groundwater table.

Ideally, the septic system will function properly for the full time that you live in your home. However, at some point your septic system will need to be replaced. This may occur because of a severe septic system problem or simply because your septic system has reached the end of its lifespan.

Prevention is the best way to keep your septic system in good condition. The most important thing is to not pour solids into your septic system, such as rocks and debris, or flush non-biodegradable objects down the toilet, such as chemicals and non-food items. It’s also important to have your septic tank pumped regularly. The frequency of this will depend on how much you use your plumbing and what you put down the drains.

If you notice a foul odor, a wet or soggy spot in the yard, slow draining kitchen or bathroom plumbing, or sewage backing up into your house, these are all signs that there may be a problem with your septic tank’s drain field. If you suspect a problem with your septic tank’s drainage, it is essential to call an experienced septic professional.