how does a septic system work bellingham wa

How Does A Septic System Work?

A septic system is a decentralized wastewater treatment system that is commonly used in rural and suburban areas where a centralized (city) sewer system is not available. It is designed to treat household waste water before it is released back into the environment.

The Septic Tank

The basic components of a septic system include a septic tank, a drain field, and a distribution box. The septic tank is a large, watertight container that is buried underground. It is made of concrete, fiberglass, or polyethylene and is designed to separate solid waste from liquid waste. The solid waste settles at the bottom of the tank and is known as sludge, while the liquid waste, known as effluent, flows out of the tank and into the drain field. Lets examine the 3 components to see how a septic system works.

The Drain Field

The drain field is a series of perforated pipes that are buried in the ground. The pipes are surrounded by gravel and covered with soil. The effluent from the septic tank flows into the drain field where it is treated and filtered by the soil. The bacteria and other microorganisms present in the soil help to break down the waste, removing harmful substances and purifying the water.

The Distribution Box

The distribution box is installed between the septic tank and the drain field. It helps to distribute the effluent evenly across the drain field and control the flow of effluent into the drain field.

The 3 Stages of Treatment

How a septic system works is in three stages: primary treatment, secondary treatment, and final treatment. During primary treatment, the waste enters the septic tank and the heavier solid waste settles to the bottom while the lighter liquid waste flows out of the tank and into the drain field. This stage helps to remove most of the solids from the waste, reducing the amount of organic material that needs to be treated in the drain field.

During secondary treatment, the effluent from the septic tank flows into the drain field where it is treated and filtered by the soil. The bacteria and other microorganisms present in the soil help to break down the waste, removing harmful substances and purifying the water. The water that has been treated in the drain field is then released into the surrounding soil where it can be absorbed and eventually recharged into the groundwater.

Finally, during final treatment, the water that has been released from the drain field continues to be filtered by the surrounding soil, removing any remaining impurities and pollutants. The water that has been fully treated by the septic system is then recharged into the groundwater where it can be used by plants and animals.

Regular Maintentance is Required

To ensure proper functioning of a septic system, it is important to maintain it regularly. This includes pumping the septic tank every three to five years to remove the accumulated sludge and prevent it from flowing into the drain field and clogging the pipes. It is also important to avoid overloading the system with excessive amounts of waste by reducing water usage, avoiding water-intensive appliances during peak usage times, and avoiding the disposal of non-biodegradable materials into the septic system.

In conclusion, a septic system is a reliable and efficient method of treating and disposing of household waste water in rural or suburban areas where a centralized city sewer system is not available. More information on how a septic system works may be obtained at the EPA. Regular septic maintenance is essential to ensure its proper functioning and prevent environmental damage.