Your drinking water - appearance

Your water should be clear. Very occasionally, for a brief period, it may appear discoloured or contain particles.


Number of times companies were contacted by customers about the appearance of their tap water (per 10,000 people supplied)

The graph shows how many times customers contacted their water companies about the appearance of their tap water in the latest year. So that companies with different numbers of customers can be compared, the graphs show the number of contacts per 10,000 people supplied. 

How do we measure up?

In 2016-17, we had 14.6 customers per 10,000 population contact us about the appearance of their water. This measure covers all contacts we received about the appearance of the water and is an improvement from the 15.7 the previous year.

The most common cause of contacts we received relate to the presence of iron and /or manganese within our distribution mains which can become re-suspended due to changes in flow and pressure within the network, for example if a water main bursts which causes temporary black / brown / orange water.

Neither iron nor manganese are harmful to health at the levels found within tap water.

We have more contacts then other water companies due to the geology of the area we supply from as the deep greensand aquifers we collect much of our water contain significant quantities of iron and manganese.

All our treatment works remove these particles, however a low level of iron and manganese will settle in our pipes and can build up over time.  To counteract this we have doubled the level of mains flushing activity within hot spot areas for discolouration, and continue to improve our treatment processes.

The past three years has seen a consistent performance but we have a strategy in place to reduce contacts about the appearance of water.

The key actions are:

  • Targeted mains renewals and treatment process improvements
  • Increasing our flushing programme from 500 to 875 miles per year
  • We have purchased specifically designed valves and trained our operations technicians accordingly. These valves are designed to reduce the risk of a mains burst and minimise sudden pressure into the system which can increase discolouration.

Top tip!

If you have white water it is probably air. You can check this by filling a glass with water. If the cloudy water rises to the surface and clears after standing for a few minutes this is air. If it stays cloudy then contact us for advice.