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Is lead harmful?

Lead is a ubiquitous element originating from a wide variety of sources such as exhaust fumes from vehicles, old paint work and leaded solder. It can bioaccumulate, which is the capacity to remain and build up a level in your body. At high concentrations it can have a harmful effect.
In recent times the Government has taken steps to reduce exposure from lead such as use of unleaded petrol and paint and plumbosolvency control on drinking water. The Drinking Water Inspectorate lowered the maximum allowable level of lead in drinking water from 50ug/l to 25ug/l at the beginning of 2004, this is due to be further reduced to 10ug/l in 2013.

Source of lead in drinking water

The primary source of lead in drinking water is from lead pipes, when water exits a treatment works it will not contain any lead. Historically lead was commonly used for the creation of water pipes and it is the remnant of these that give the problem. When drinking water travels through a lead pipe it can pick up lead, especially in areas with soft water.

Plumbosolvency control

Dee Valley Water has a statement of intent to reduce lead concentrations within its area of supply. An initial investigation was undertaken using Drinking Water Inspectorate criteria examining lead results from differing supply zones. This information was used to determine which treatment works would be included in the plumbosolvency scheme.

The zones that were found to need plumbosolvency control under the DWI guidance were:

Click here to locate your supply zone. (Takes you to another screen)

How Does Plumbosolvency control work?

Plumbosolvency control is achieved for the zones listed above by the addition of ortho-phosphate to the water supplied to them. Dee Valley commenced ortho-phosphate dosing in 2002. The ortho-phosphate is readily adsorbed on to the pipes it travels down forming a protective film around the inside of the pipe. This film forms a barrier between the water and the lead, thus prohibiting the lead being dissolved into the drinking water.

How can I tell if I have lead pipes?

If your house was built before 1970 there is a possibility it contains lead pipes.
If your house was built after 1970 or has had pipework modernised since then it is unlikely to have lead pipes.

How can I reduce the amount of lead I drink?

If you do have lead pipes then the easiest way to lower the amount of lead you drink is to always run the tap before drawing off water. This is especially true if the water has been standing in the pipe for any length of time, such as overnight. By flushing the supply like this you are removing the water that has spent time in contact with the lead.

For further information on water quality click on the link below to view the
Drinking Water Inspectorate web page.