Dwr Cymru Welsh Water

COVID-19 (Coronavirus) – A Message to Our Customers - 30 March 15:00

We know that this is a difficult time. We also know that the water and wastewater services we provide play a key role in protecting public health and safeguarding the customers and communities we serve.

We are doing all we can to protect our colleagues while also maintaining our services to customers. You will still see us working in streets and communities during this time but we are only doing essential work that will help protect public health by maintaining water and wastewater services to customers.

Our Billing Call Centre is open from 9am - 5pm (Monday to Friday) to support our most vulnerable customers who have been impacted by the Coronavirus.

If you’re impacted by COVID-19 (Coronavirus) and concerned about your water bill, please click here for more information.

If you need to contact us about other things like updating your account, to let us know you are moving or to set up a direct debit, you can do this by visiting our online services.

We will keep you informed of any other changes through updates on this site and via our social media channels - Facebook & Twitter.

We apologise for this but will do everything we can to continue providing our essential services. Thank you for bearing with us.

Combined Sewer Overflows (CSOs)

Combined Sewer Overflows (CSOs)

One of the most important things we do is protect public health by taking away wastewater—which can include foul sewage and rainwater from roofs, gardens, and roads—from homes and communities to be treated and returned safely to the environment.

Most of our sewers are ‘combined sewers’. This is usually one single pipe that carries both wastewater from our homes and businesses and surface water from our gutters, drains and roads.

How Combined Sewers Work

When our sewer system is operating normally, combined sewers collect rain water that runs off gutters, drains and roads, as well as sewage. We call this wastewater, which then gets taken to our treatment works, where it is cleaned, treated and returned safely to watercourses and the sea.

This means that during heavy storms, more water is getting into these pipes than they can cope with so they have been designed to safely relieve the pressure on our systems. These release mechanisms are known as Combined Sewer Overflows, or CSOs.

Sometimes, during heavy rainfall, we have to protect our customers and their homes and businesses from sewer flooding so this CSO ‘release’ system is vital. Without it, sewerage systems would back up, flooding buildings, streets, highways and open spaces with diluted sewage and rainwater from manholes, drains and toilets.

Usually, this only happens when there’s been heavy rain, so any water that is released into rivers or the sea is unlikely to cause environmental damage.

We have permission for sewers to overflow via environmental permits from our environmental regulators, Natural Resources Wales and the Environment Agency.

Environmental performance and investment

As a company so closely linked to the environment, we are very aware of the impact our work has on our surroundings and take our environmental performance very seriously. Safeguarding our coastal waters and rivers from pollution is one of our top priorities and most important responsibilities.

Since 2001, we have invested over £1billion in sewage treatment and network improvements to improve bathing water quality which has resulted in Wales securing 47 Blue Flags for the 2016 summer bathing season (44 beaches and 3 marinas) – around a third of the UK’s Blue Flags – despite managing only around 15% of the British coastline.

As part of our Environmental Investigations Programme, we have placed monitors on many of our CSOs. These tell us the number of times a CSO has overflowed which confirms if our sewerage network is operating as it should – it does not measure how much water has been released, the quality of the water that has been released or environmental impact.

You can find out more about the CSOs with monitoring systems in your area here