Cheaper ways must be found of ensuring that children and babies in the womb are protected from dangerously high lead levels, Judith Rees, a geography professor at Hull University, told the conference yesterday.
The World Health Organisation has recently lowered its guideline limit for the average lead level in tap water to 10 micrograms per litre. Lead is a potent toxin thought to be capable of damaging brains and lowering children's IQs.
The WHO has put pressure on the European Union and the British government to lower the maximum limit in the EU's drinking water directive - 50 micrograms per litre. At present, hundreds of thousands of households in Britain still receive tap water above this level.
Estimates of how much it would cost to comply with the stricter limit by removing lead piping are vague, but run into billions of pounds.
To remove all lead mains and plumbing from the 9.4 million homes that have it would cost about pounds 10bn, according to the water industry. However, in hard water areas, the presence of lead piping does not lead to high lead levels in tap water. In soft water areas, the acidity disolves lead from the pipes, resulting in levels above the limits.
The Government has not yet produced its own figure for how many homes should have their lead plumbing removed. It depends on what limit is enforced. There is also uncertainty about who should pay and how a programme to lower lead levels can be delivered effectively.
The water companies are responsible only for dealing with lead piping outside the boundaries of homes. It is the lead plumbing within houses, the responsibility of the householder, which bears most of the blame for high lead levels.
There are government grants available for households on state benefits for replumbing and some water companies offer discounts, but the uptake is low.
Professor Rees, chairman of the water regulator Ofwat's southern region customer service committee, said the lead issue could spark the next national row over the rapidly rising cost of water services. But she said it should be government policy to bring lead levels down.
It would be cheaper to offer free bottled water to households with pregnant women and young children than to replace lead piping, she said.
Alternatively, 100 per cent grants could be made available for these households to have replumbing work done.Reuse content