How Does the UK Sewer System Work?

In the UK, we are fortunate to have a well-established sewage system that efficiently handles our wastewater. However, on a global scale, the situation is different. With population growth and urbanization, the volume of wastewater generated is increasing, leading to pollution and health hazards.

Developing countries often lack advanced sewage systems, relying on open trench drainage channels that transport waste to inadequate treatment facilities. This lack of sanitation hampers social and economic development while polluting the environment.

Shockingly, it is estimated that more than 80% of wastewater worldwide is released into the environment without proper treatment (UNESCO, 2017). This highlights the urgent need for improved wastewater management practices globally.

The History of Sewage Systems in Britain

The history of sewage systems has certainly seen significant improvements over time!

In the past, London's sewage system was incredibly basic, with open ditches leading directly to the polluted River Thames. As the city's population grew in the 1800s, several cholera outbreaks occurred, leading to the belief that the diseases were caused by contaminated air or "miasma."

The "Great Stink of London" in 1858, during a hot summer, intensified the unbearable smell from the Thames, prompting the need for a modern sewerage system. Joseph Bazalgette, a civil engineer, was appointed Chief Engineer of the Metropolitan Board of Works to design and execute the project.

A comprehensive underground sewerage system was created to divert waste to the Thames Estuary, downstream from the densely populated areas. The new low-level sewers, built behind riverfront embankments, intercepted and redirected foul water from old sewers and underground rivers to the new treatment works.

This revolutionary system greatly improved the hygiene and sanitation of the population, serving as a model for sewer system upgrades across the UK. It marked a significant milestone in the management of sewage and contributed to the overall well-being of communities.

The Modern Sewage System

Our modern sewerage system plays a crucial role in maintaining our desired quality of life. By offering a safe and hygienic waste disposal method, it safeguards us from the potential dangers of infection and disease. Moreover, it ensures that unpleasant smells and the sight of wastewater are rare occurrences. With effective wastewater treatment, we can rely on access to clean water for both drinking and irrigation purposes.

How the modern system works:

1. Wastewater is taken away – wastewater disposed of via toilets, sinks, showers or baths are channelled into underground foul water drains and sewers which lead to sewage treatment works.
2. Screening – this stage removes objects that should never have been flushed in the first place including nappies, wipes, sanitary items, cotton buds and other large objects. Wastewater also usually contains grit and this is removed as part of this process.
3. Primary treatment – at this point the wastewater will still contain human waste, this is separated at this stage. To do this the wastewater is put into large settlement tanks where the solids will sink to the bottom of the tank forming sludge, this is pushed towards the centre of the tank where it is pumped away for further treatment.
4. Secondary treatment – this process will remove smaller particles and bacteria. The wastewater for this stage has air pumped into it which encourages good bacteria to break down the bad bacteria.
5. Final treatment – The treated wastewater is now passed through a final settlement tank where the good bacteria sinks to the bottom creating more sludge. The clean water filters out of the top of the tank.
6. Sludge treatment – most of the sludge collected from the start of the process will be treated and recycled for farmers to use on agricultural land and also used to generate energy.
7. Back to the river – treated wastewater can now be returned to rivers and streams.

How are Sewers Maintained?

In densely populated areas, it is crucial to prioritize the maintenance of sewer and drainage systems to prevent a return to unsanitary conditions of the past. Today, we have advanced cleanliness and hygiene practices that must be upheld. Taking simple steps can help keep the drains and sewers connected to your home clear, such as avoiding flushing 'unflushable' items and refraining from pouring grease down the sink.

To assess the integrity of your drains and identify any blockages, CCTV surveys provide valuable insights. In addition, our drain and sewer jetting services efficiently remove any blockages discovered, ensuring optimal functionality.