Difference between Septic Tank and Cesspit
All about the differences and similarities of these wastewater systems
There is often confusion about what the exact difference is between a cesspool and a septic tank. Many people mistakenly use the term cesspit to refer to a septic tank and vice versa. However, there is an essential difference between the two pieces of equipment.
A cesspit (also known as a cesspool) is designed to only receive water from the toilet, commonly referred to as black water. In the past, the ‘bear’ from the cesspool was used as manure on land. Nowadays, we no longer do this because of the risk of infection as well as, the presence of medicines and antibiotics.
On the other hand, a septic tank handles both “black water” (toilet waste) and grey water, which is domestic wastewater from sinks, showers, and washing machines. This waste-water contains fats, soap, toilet waste, food waste and everything else that is flushed down the toilet or sink.
As you can see, there is quite a difference in the waste-water supplied, which is why a difference between the septic tank and the cesspool in terms of the bacteria present in the tank. The products used to maintain these bacteria are also different.
How Septic Tanks and Cesspits Work
Septic Tanks: Function and Operation
A septic tank is an underground chamber designed to treat and dispose of domestic wastewater. It receives effluent from toilets, sinks, showers, and washing machines. Inside the tank, solids settle at the bottom, forming sludge, while oils and grease float to the top, creating scum. The liquid effluent, now partially treated, exits the tank and is typically discharged into a drainage field or soakaway, allowing further filtration through the soil.
Cesspits: Function and Operation
In contrast, a cesspit is a sealed underground container that solely collects sewage from toilets. Unlike septic tanks, cesspits do not treat wastewater. They store the waste until it is removed by a licensed waste carrier. Regular emptying is crucial to prevent overflows and environmental contamination.
Environmental Impact of Septic Tanks vs. Cesspits
The environmental implications of using septic tanks and cesspits differ significantly. Septic tanks, when properly maintained, can effectively treat wastewater, reducing the risk of groundwater contamination. However, if not properly maintained, they can leak untreated effluent, posing environmental hazards. Cesspits, lacking treatment capabilities, can lead to soil and water pollution if not emptied regularly, as they store untreated sewage.
Common Misconceptions About Cesspits and Septic Tanks
Several misconceptions exist regarding cesspits and septic tanks. One common myth is that septic tanks require no maintenance. In reality, they need regular inspections and periodic emptying to function correctly. Another misconception is that cesspits are a cheaper option. While they may have lower installation costs, the frequent emptying required can make them more expensive over time.
The Legal Requirements for Septic Tanks and Cesspits in the UK
In the UK, there are specific regulations governing the use and maintenance of septic tanks and cesspits. Under the Public Health Act 1936, it is an offence to allow a cesspit to overflow or leak. Property owners are responsible for ensuring their cesspits do not leak or overflow, as such actions can lead to prosecution.
For septic tanks, the Environment Agency enforces regulations to prevent pollution. Discharging untreated sewage into surface water or groundwater without a permit is illegal. Property owners must ensure their septic tanks meet the general binding rules or obtain the necessary permits.
Sources: CastlePoint & Gov.uk
Key Similarities and Differences Between a Cesspit and a Septic Tank
While both systems deal with wastewater, there are several key differences and a few similarities:
Wastewater Discharge:
- Most cesspits do not discharge into a sewer system. Instead, they store the waste until it is manually removed.
- A septic tank, however, typically discharges treated wastewater either into surface water or a sewer system after processing.
Compartments:
- A cesspit generally consists of a single compartment where the waste is stored.
- In contrast, a septic tank usually consists of multiple compartments to allow for separation and partial treatment of solids, liquids, and scum.
Size:
- Cesspits are often smaller than septic tanks, as they do not require the additional compartments for waste treatment.
Maintenance Frequency:
Both a cesspit and a septic tank require regular checks and maintenance. It is recommended to inspect them annually and have them emptied if necessary. This ensures proper functioning and prevents potential issues for both systems.
