Phillip Clisham Explains Why Sewage Is Ending Up in UK Seas.

What are storm overflows?

Until well into the second half of the 20th century, it was standard practice in the UK and most of the developed world to provide ‘combined sewers’.

Combined sewers carry dirty water from toilets, sinks and showers, and rainwater (surface water), combining both into a single pipe.

When it rains very heavily, the volume of rainwater can become too great for the pipes and some sort of overflow arrangement is needed to ensure that properties aren’t flooded.

There are approximately 15,000 storm overflows in England discharging to inland rivers, estuaries, the sea, and other water bodies.

Many of these have been in operation since the first sewers were built over 150 years ago.

Across Europe, there are 650,000 storm overflows.

As such, storm overflows aren’t new and exist in all developed countries.

Are storm overflows a problem?

While the effluent (liquid waste or sewage) that’s discharged from storm overflows should be mainly rainwater, there will still be a quantity of untreated sewage.

This can affect the health of rivers as the discharges can introduce ammonia and reduce the levels of dissolved oxygen in the rivers.

Storm discharges can also contain high levels of bacteria, which can cause harm to public health.

These discharges can also have a ‘social impact’ as the effect of seeing untreated flows from sewers being discharged into rivers causes concern.

If the storm overflow spills too often or discharges to a sensitive location, then the overflow can cause harm.

What type of earth anchors can be choosed for the pipe?

For the pipe fixing, usually choosing single or double helical ground anchor. These type earth anchors are better for installing and low cost.

What can be done?

While there are a variety of things that can be done to reduce the problem, the main solutions include storing the sewage in huge underground tanks, rather than discharging to the environment.

However, there are limits to how much can be stored within a catchment before other problems are created.

Another approach is to separate the surface water and the sewage at source, but this is difficult in congested urban areas and can become very expensive.