What is a Septic Tank?

A septic tank is a watertight container where wastewater collects and separates. Heavy solids sink to the bottom, and lighter materials float to the top, where bacteria break them down in an anaerobic process. The liquid layer, called effluent, is released to the drain field. 

A full septic tank can clog pipes in the absorption field and reduce its ability to filter wastewater. When this happens, pumping is required. Click https://www.septictankarmadale.com.au/ to learn more.

septic tank

A septic tank is a large, buried, and watertight container that collects waste from household plumbing. Wastewater enters the septic tank through a single inlet pipe and remains inside long enough for the solids to settle to the bottom, forming sludge—oils and grease float to the top, creating a scum layer. The middle layer is liquid wastewater, known as effluent. Compartments and a T-shaped outlet keep sludge and scum from leaving the tank and traveling into the drain field, where they can clog up the perforated pipes and cause further damage to the soil.

The septic tank relies on naturally occurring bacteria to break down the solid materials in the wastewater. This is called anaerobic treatment. The septic tank is sized to hold the volume of wastewater the house generates. The larger the tank, the less frequently it needs to be emptied.

Most modern septic tanks have two chambers separated by a wall. The sludge layer rests on the bottom of the tank, and the scum layer lies above it. A baffle limits the amount of sludge reaching the inlet and outlet pipes, usually located several inches above the scum layer. The tank also has a maintenance hole cover, often with a riser on the ground surface, to allow the lid to be accessed for inspection and pumping.

When the septic tank is full, a float switch closes the inlet, and an alarm goes off. The tank is then pumped clean, typically by a professional, to prevent sewage from flowing into the home or back up into toilets and sinks.

Maintaining the septic system properly requires careful maintenance and frequent inspections. A professional can help determine the size of the septic tank needed to hold the amount of wastewater generated by the house and recommend a schedule for pumping. The tank and septic system components are located on the property, so homeowners should keep pets and children away from the area to avoid getting contaminated by toxins or debris that could flow into the drain field.

When wastewater enters the septic tank, it is forced by gravity into one of two chambers. A baffle in each pipe prevents solid waste from flowing into the other chamber, where it could clog the outlet pipes to the drain field. The baffle is also designed to dissipate the energy of incoming sewage to avoid turbulence and disrupt the segregation of scum and sludge.

When septic tank sludge and scum enter the drain field, it is exposed to further bacterial action and to water and oxygen that leaches contaminants into the soil. These processes can neutralize disease organisms and reduce the concentration of nitrogen, phosphorus, and other pollutants in the effluent that eventually seeps into groundwater sources.

The liquid effluent leaves the septic tank through the distribution device, which distributes it evenly over the drainfield area. The infiltration field helps to filter the liquid effluent as it seeps into the soil, and further bacterial action treats the contaminated water.

After primary treatment, the liquid effluent passes to the absorption field for final treatment and absorption into the earth. The drain field is a series of perforated pipes that allow the liquid to slowly trickle into the soil, which the surrounding sand and organic material will absorb.

Septic tanks are made of many materials, including reinforced concrete and fiberglass. Concrete is usually preferred, as it offers a watertight seal and is not prone to damage from frost or corrosion from chemicals in household cleaning products.

Fiberglass tanks are sometimes used but can crack or corrode over time. Metal septic tanks can be used, but they are less desirable. They are prone to corrosion and leakage, even when coated with a protective bituminous coating.

The inlet and outlet pipes of the septic tank must be sloped to promote flow and prevent clogging. The inlet tee of the tank should have a baffle to direct wastewater downward, and the inlet baffle should extend at least 1 inch above the top of the inlet sewer line. The outlet tee should be at a height below the level of floating scum in the tank, and it should have a tee with a 22-degree elbow to direct incoming effluent down into the septic tank liquid.

A septic tank is a big concrete or fiberglass watertight container that sits underground close to your house. It holds wastewater from toilets, kitchens, and washing machines. Once it reaches the tank, the waste is broken down by bacteria. The resulting effluent is then piped to the drain field, broken down, and absorbed into the soil. This process is natural and works well, provided the septic tank is properly sized, the pipes are in good condition, and the drain field is regularly inspected.

The septic tank has three distinct layers: solids that sink to the bottom, grease and fats that float to the top, and clear liquid waste called sludge in the middle. The sludge layer consists of the byproducts of the decomposition of other waste in the tank and is broken down over time by the bacteria. The liquid waste, the scum layer, and the sludge layer are pumped out of the tank into a drainage system, including a drainpipe that runs to your yard.

As the wastewater trickles down through the drainpipes into the drain field, it enters the gravel layer, where bacterial action continues. The microbes treat the sewage in the drain field like a composting machine, percolating it through the soil and breaking down harmful bacteria and viruses before seeping into groundwater. The soil also filters the wastewater on a micro level, acting like a coffee filter.

Suppose you notice a foul odor around your home, a wet or soggy area over the drain field, slow-to-draining kitchen and bathroom fixtures, or sewage backups in your toilets. In that case, the septic tank or drain field is likely impacted by too much water too quickly, a clog in the drainage pipe, or too many solids in the sludge layer.

Regularly scheduled septic tank inspections will detect any problems and repairs that may need to be made. The most common septic system problems are with the drain field. The causes of these problems are related to the overuse of water-generating appliances such as washing machines and dishwashers, tree roots that can clog and damage pipes, the use of detergent products with high levels of phosphate, which encourage the growth of algae inside the tank, and infrequent pumping of the septic tank.

Septic tanks need to be pumped out regularly to prevent solid wastes from flowing out of the tank into the drain field. These solids can clog the pipes, causing them to overflow or back up into the home. Pumping the tank removes the sludge and scum, helping maintain the system’s health.

The frequency of pumping a septic tank depends on how many people live in the house and the types of products used. For example, a three-bedroom, two-bathroom house with four people living in it requires a larger tank than a one-bedroom, two-bathroom house. A large family will use more soaps, detergents, and other household products that wash into the drain lines, increasing the need for a bigger tank and more frequent pumping.

Fortunately, there are ways to reduce the need for routine septic tank pumping. Having the tank inspected annually by a professional will allow you to know how much sludge and scum are in the tank, which will help determine its fill-up rate. The more solids in the tank, the higher the fill-up rate and the more often you will need to have it pumped.

If you are unsure what your tank size is or how much sludge and scum it holds, consult your house’s original building plans or homeowner’s manual. These documents will tell you the size of the tank, how many gallons it can hold, and the location of the septic tank. If you have lost these documents, try locating the septic tank by following the sewer line from your house or looking for inspection ports, usually small capped pipes on the side of the septic tank.

You should never enter a septic tank for any reason, even if it is empty. The decomposing wastes in a septic tank emit toxic gases that can kill a person within minutes unless they are wearing a self-contained breathing apparatus. Instead, a professional will be able to inspect the condition of the baffles and other components without entering the tank.

Other routine maintenance includes reducing the amount of organic waste that goes into the drain fields by eliminating or minimizing food waste from garbage disposals and pouring oil-based paints, solvents, or cleaners down the drains. Also, removing roots from the tank and drainfield area will help keep the system in good working order.