Lead is one of the most toxic heavy metals when it comes to human health, especially where quantities in water supplies are consumed over a long period. This risk applies even at very low concentrations.
Water produced at the State’s 900-odd treatment plants is, fortunately, lead-free, as is the water mains network which carries it due to remedial works carried out in recent decades.
However, for many years lead pipes were used in “service connections”; the pipes running from the public mains to houses, and routinely used in the plumbing of homes up to the mid-1970s. The lead in these pipes can leach out in to the water. Some of the pipes, especially in Dublin, date back to Victorian times.
Irish Water has estimated that about 180,000 homes are affected, but only those built before 1980. Its national plan to address the issue has already led to some 38,000 householders being notified they have lead pipes.
One of the benefits of installing water meters outside houses was the ability to check if lead pipes were connecting from the mains to households.
The latest evidence, according to the HSE and the EPA, indicates no level of lead in drinking water is considered to be completely safe – so it should be minimised at all costs.
Consumption of lead can affect brain development of children, infants and babies in the womb most at risk. It may harm kidneys, may contribute to high blood pressure and has been linked to cancer.
The ultimate solution is to replace the lead pipes, confirmed EPA programme manager Darragh Page, and this should be done as soon as possible because of the latest evidence on its toxic effects.
A certain level of monitoring is required by law depending on the size of supply – the EPA checks a few thousand samples a year. But, he added, Irish Water was doing more than required “to find where the problems are”.The levels found by Irish Water recently were similar in some instances to those found by the EPA in the past, he said.
Irish Water is to spend €370 million over the next decade replacing lead pipes in the public water supply, and where houses have shared backyard service connections it will also replace these. It will not replace pipes under front gardens or in houses. But there are substantial grants available, depending on how much lead plumbing is on the property and the income of the owners.
As an interim measure, Irish Water plants could dose water supplies with orthophosphate, a chemical which forms a protective film around the inside of the pipe providing a barrier between water and the lead. Where this has been tested on a pilot basis in two areas of Dublin, it has proven to be effective.
It is a “food-grade product and is a clear, odourless liquid” which is commonly used in the beverage industry. The HSE has said there are no public health implications from its use though too much phosphate (mainly due to fertiliser run-off and other detergents) can occur in rivers and lakes which can be environmentally damaging, so sewage may have to be treated to remove it at some locations.
The lead test results revealed by The Irish Times did not indicate the problem was out of control, Mr Page said, but it did confirm “a very significant problem, which won’t go away unless people endeavour to change their pipes”.