John Gormley
Question:481 Mr. Gormley asked the Minister for the Environment and Local Government the levels of lead in drinking water; and the possible sources of this lead. [9150/98]
Written Answers. - Water Quality.
Details of lead levels in drinking water are outlined in the annual reports on the quality of drinking water in Ireland, published by the Environmental Protection Agency. A copy of the most recent report, in respect of 1996, is available in the Oireachtas Library. The analytical data for lead are included with the results for heavy metals. They show that lead poses few problems in Irish drinking waters and public health is not endangered.
Where lead is detected in drinking water supplies the primary cause is the interaction of certain types of water with lead distribution mains and/or domestic plumbing systems.
John Gormley
Question:482 Mr. Gormley asked the Minister for the Environment and Local Government if he will supply a list of all known or probable carcinogens and their levels in average drinking water as it reaches the consumer. [9372/98]
The European Communities (Quality of Water Intended for Human Consumption) Regulations, 1998, giving effect to the Drinking Water Directive, 80/778/EEC, set upper concentration limits for a total of 53 bacteriological, chemical and physical parameters for the purposes of ensuring high quality water supplies and the protection of public health.
I am advised that the parameters arsenic, cadmium, chromium, selenium, dissolved or emulsified hydrocarbons, polycyclic aromatic hydrocarbons, pesticides and related products and other organochlorine compounds, including trihalomethanes, were included in the directive on a precautionary basis having regard to their possible carcinogenic properties or other concerns about their implications for public health.
I am aware of reports suggesting possible links between excessive levels of nitrates and fluoride in drinking water and cancer. I am informed, however, that the reports have not been confirmed in more definitive analytical studies.
The latest information on the monitoring of drinking water quality is contained in the Environmental Protection Agency's report on the quality of drinking water in Ireland, 1996, which also includes a review of water quality over the period 1994 to 1996. The agency has conducted a separate survey of pesticide levels and has presented its findings in the report, Pesticides in Drinking Water (1996). Copies of both reports are available in the Oireachtas Library.
John Gormley
Question:483 Mr. Gormley asked the Minister for the Environment and Local Government the alternatives which exist to chlorine as a water purifier. [9373/98]
There are a number of alternatives to chlorine for the disinfection of public water supplies, such as ozonisation and ultra-violet radiation. However, none of these is considered to be as effective as chlorine, particularly since they do not maintain an active residual disinfection capability in the distribution mains to counteract possible contamination of the mains or service pipes.