Tap water cleaner, lead still a problem

Tap water quality in England and Wales improved in 2005 but lead contamination remained a problem, the annual report from the drinking water watchdog has found.

Overall, water quality improved, with 99.96% of water samples in compliance with UK and European norms for 2005, compared to 99.94% for 2004, the report from the Drinking Water Inspectorate found.

While lead levels were on the way down, meeting rising health and safety standards for this dangerous pollutant would be a “complex” challenge, chief inspector for drinking water Prof. Jeni Colbourne said.

Problems with high iron and nickel levels also persisted, iron contamination being the most severe in the North and South-West, and nickel confined to the East, closely tied to the nature of the soil and groundwater.

Lead in drinking water originates mainly in pipes, giving it a higher correlation with individual properties than geographical regions. It is also of greater concern than iron and nickel due to its tendency to accumulate in the body and cause neurological health problems in young children.

Where old lead pipes are in place, the extent of lead picked up by water flowing through them depends on a range of factors such as temperature, acidity and water hardness, as well as more obvious variables like the length of the pipe and the time water is left to stand.

The current limit of 25 micrograms of lead per litre in drinking water is still exceeded in a small number of properties with lead pipes, the DWI said.

Following guidance from the World Health Organisation being taken up in the Water Framework Directive, this limit will fall to 10 micrograms per litre in 2013.

Prof. Jeni Colbourne said: “At the request of local authorities I report, this year, on progress towards meeting the future stricter lead standard.

“In England and Wales only 0.26% of tap water samples now fail the current standard of 25 micrograms per litre and the number of samples failing the future more stringent standard of 10 micrograms per litre is now in decline.

“Now is the time for water companies and local authorities to work together to identify the need, if any, for local action plans”.

Meeting the new standard attain using current treatment methods will be a “complex matter” as it would require the replacement of lead pipes – an investment that not all owners of buildings will be willing to make, Prof. Colbourne said.

Currently, water is treated with phosphate to prevent lead from dissolving into it, but this will not be sufficient to attain the new standards everywhere, she said.

On overall water quality, Prof. Colbourne said: “My inspectors carry out rigorous checks throughout the year and I am pleased to report that nationally, drinking water quality improved in 2005 with 99.96% of tests meeting the standards”.

Environment minister Ian Pearson said: “The results show that England has some of the world’s best quality tap water. This is a direct result of the massive investment made in the way that our water is treated and supplied.”

“I welcome the fact that the DWI will help the independent consumer representative, the Consumer Council for Water, work with water companies to make sure that customers are well informed and their voices heard,” he said.

The report, which includes an explanation of water quality monitoring (Part 1), and overviews of results by water company (Part 2), and by region (Part 3), can be accessed here.

Goska Romanowicz

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