What is a septic tank? How does a septic tank work?

It’s not something we enjoy thinking or talking about but effective drainage is increasingly important in the age of growing households and water shortages. Septic tanks have been popular as a water treatment solution for many years. A septic tank, if properly maintained, can last decades, making it a good money saver. This is reliant on you actually knowing what a septic tank is and how best to manage it, however. A poorly maintained septic tank may need replacing after only a few years. Do not fret however as this article will lay out what a septic tank is and how it works as well as how to maintain it.

What is a septic tank?

A septic tank consists of an underground chamber that is often made of concrete, fibreglass or plastic. Wastewater from your domestic facilities such as your toilets, sinks, and showers drain into the septic tank chamber for basic separation. The water then passes through a filter and ends up in a drainage area. This area usually contains gravel and bacteria in the soil and gravel cleans the water and allows it to seep into the groundwater.

How does a septic tank system work?

The septic tank works through the use of bacteria. They break down waste, leaving water clean enough to safely percolate down into the earth. The whole system is designed to keep the bacteria alive and active as they are crucial to breaking down the waste and purifying the water. Some of the bacteria is in the tank, but most do their work in the drain field.

• All waste flows to the septic tank.
• The water waste in a septic tank is called the ‘effluent’. Anaerobic bacteria begin breaking down the organic material in the effluent.
• The septic tank separates the waste through the use of density. Heavier solids sink to the bottom and greases and oils float to the top.
• A filter prevents most solids from entering the outlet pipe.
• Effluent flows to the drain field.

The drain septic field provides a large area where bacteria can thrive and treated water can seep into the ground. Holes in the drain septic field pipe allow effluent to seep into surrounding gravel. Gravel around pipes allows water to flow into soil and oxygen to reach bacteria.

• The aerobic bacteria completes the purification process of the water.
• The water then seeps down into the groundwater.

How best to manage your septic system

A septic tank system needs to be regularly drained by a professional to avoid overflowing. You can check the level yourself via the use of a sludge judge, a widely available device that often costs around £100. It is quite a bit to pay out but it means you have a greater idea of your septic tank levels and can best judge when it needs to be drained (when the sludge reaches around ⅓ of the stick). It can save you from unnecessary inspections or the possibility of overflowing.

So that was an introduction to septic tanks and how they work. I hope you found this useful and I’ll leave some links down below in order to help further and give you some further information. It's not a particularly fun subject but knowing about drainage and sanitation systems can save you money and unpleasantness down the line so it's always good to read up on your system and any maintenance tips or requirements.

https://www.familyhandyman.com/project/how-a-septic-tank-works/

https://www.gov.uk/permits-you-need-for-septic-tanks

https://www.vivint.com/resources/article/5-signs-your-septic-tank-needs-emptying

https://www.drainforce.co.uk/cesspit-septic-tank-emptying