Providing clean water

Welsh Water provides safe and reliable drinking water to over 1.4 million homes and businesses, making us the sixth largest of the 23 water companies in England and Wales.

We have impounding reservoirs, which are water storage areas. These are mainly created by building dams across river valleys and upland areas. We have water treatment works where reservoir water is treated to make it safe enough to drink, these supply over 800 million litres of water every day through a network covering 27,000km.

By the time water reaches rivers, reservoir or aquifers, water already contains a wide variety of substances which determines its quality. It absorbs dirt, dust and gases from the air, debris and bacteria from the ground, and soluble minerals from rocks.

At a water treatment works the main objective is to destroy the bacteria and remove as many unwanted substances as possible.

Delivering great volumes of water to virtually every domestic, agricultural and industrial premise in our area requires a vast network of pipes and mains.

In Britain today people take access to clean safe drinking water for granted. Water is a natural resource that has to be cleaned before it is safe enough to drink. The water you see in the reservoirs is raw water. It needs to be cleaned and treated to a high quality and delivered 24 hours a day, 365 days a year. This requires a high degree of engineering and scientific skill.

Testing Water Quality

Supplying high quality drinking water at all times is a priority to us. Over the course of a year some 300,000 water tests are taken, analysed and of the water we supply 99.96% meet drinking water quality standards at customer taps.

Every day water samples are taken and analysed. We test for organic chemicals (carbon based chemicals such as those you find in pesticides and herbicides) inorganic chemicals (such as iron, lead, manganese and aluminium) and microbes (eg bacteria and viruses).

The water samples are brought daily from our reservoirs and water treatment works and we test them at our laboratories equipped with state of the art instrumentation which are all capable of detecting part per trillion levels of trace compounds in the samples tested. 1 part per trillion is equivalent to 1 second in 31,000 years!

Reservoir Safety

Reservoirs might seem like a great place to cool off, but there are lots of dangers hidden under the water. If your friends ask you to swim in a reservoir, always say no! However, there are many fun activities that you can do at our visitor centres.

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