Toxic legacy of water pipes

Utility Week (8 February) published a feature article, ‘Toxic Truth’ on lead in water supply pipes. Most people might have thought that this was something banished from our drinking water long ago and a lot of progress has been made in removing lead pipes from the water mains. However, up to 40 per cent of UK homes still have lead water supply pipes – the bits of the network that connect properties to water company mains.

The use of lead as a plumbing material in house construction was being phased out during the 1950s and 60s. By the 1970s locally made water byelaws had been introduced that placed a ban on the use of lead plumbing. Whilst it is not compulsory for domestic customers to replace their own lead pipes, Scottish Water must advise their customers of the risks posed by lead pipes, particularly those used for drinking water purposes. Scottish Water has been replacing its own communication lead pipes as it replaces mains pipes.

Lead is a toxic substance, which has a cumulative effect, so chronic exposure at low levels builds up. It is known to raise blood pressure, cause kidney problems and has even been associated with raised levels of violent crime. Ian Walker, innovation director at research body WRc, said, “It is not acceptable for children to drink water that contains lead.”

But the regulatory framework is not so absolutist, with Ofwat (covering England) resisting allowing water companies to replace supply pipes. They argue this is a cross subsidy and the responsibility of property owners. Despite the fact that the companies pay for the dosing of water with expensive phosphates, which lines the rogue pipes.

In Scotland the Drinking Water Quality Regulator (DWQR) monitors the quality of our water. They reported that 9% of the failed water samples coming from household taps were due to lead. Although the actual number of failed samples are small, this understates the problem because it only fails  if  lead levels exceed the EU approved level of 25 micrograms per litre. There is no safe dose of lead with damage caused at very low levels of exposure. The latest DWQR report states:

“The standard for lead will reduce from 25mg/l to 10mg/l in 2013, and Scottish Water needs to continue to implement measures to reduce the amount of lead in water supplies and produce a documented strategy for doing so.”

Scotland has a particular problem with the quality of water from private water supplies. These are monitored by local authority environmental health departments that are under particular pressure at present from council cuts. The numbers of staff have cut significantly. 131 tests on private water supplies failed due to lead. The DWQR report states:

“Lead continues to be an issue with some PWS, with 6.35% of all samples taken failing the standard. 5.17% of Type A samples failed, and 7.54% of Type B. Lead is dissolved into water from lead pipes, and it is advised that lead pipes in contact with drinking water should be replaced wherever possible. The standard for lead across Europe will tighten from 25μ/l to 10μg/l at the end of 2013, and based on the figures for 2011, the number of failures would almost double from 6.35% to 11.98%.”

This is mainly a problem in rural areas like Highland, Perthshire, Borders and Argyll and Bute.

There is a debate starting in England that questions why all supply pipes are not transferred to water company ownership. Water supply pipes are not the only source of lead exposure, but they are perhaps the most readily isolated and tackled. It will be a political decision as to whether this toxic legacy will be addressed.

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