Waste water is collected by our 35,00km sewer network. Our sewers are much bigger than our water pipes because as well as taking away the water we supply some also carry away rainwater from around properties and roads – these are called combined sewers. Much of the sewer network is old, and the average age of Welsh Water's sewers is 60 years, although some date back to Victorian times.
In places the sewer network cannot always cope with today's much higher demands and occasionally, especially after heavy rainfall, overloaded sewers can cause flooding of properties. We calculate the risk of this happening and reducing the risk of sewage flooding is a priority for us. Between 2000 and 2005 we alleviated sewer flooding for 886 properties and plan to maintain this high level of investment during the current investment programme 2005 – 2010.
Addressing sewer flooding
We are always mindful of the trauma that can be caused when properties are flooded by sewage. When customers are affected by sewage flooding they are entitled to compensation.
For further information on sewage flooding, please refer to our Floodcare.
Fat, oil and grease (FOG) in sewers
The following document contains best management practise for catering outlets. It advises food establishments of the need to keep fat, oil and grease out of drains and sewers. When they are disposed of down kitchen sinks or drains they cause blockages; when they enter rainwater pipes or gullies they cause pollution in streams and rivers.